The yuan's latest bout of weakness, catalysed by concerns over the brewing China-U.
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Reddit's r/hackintosh is littered with recent posts that have been catalysed by the new MacBook Pro.
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A recent report by DIUx, entitled "China's Technology Transfer Strategy", analysed this; its findings catalysed the FIRRMA legislation.
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These not only helped the recovery of food production, but catalysed the spread of community organizations and helped restore social cohesion.
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"MARK has already catalysed markedly the market, as banks have disposed of distressed commercial real estate assets recently more actively," said the central bank.
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In Russia and Turkey change is most likely to come from shifts within the ruling party, albeit ones that may be catalysed by street protests.
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"That Surgeon General's report catalysed a half century of work on tobacco control and now the smoking rate is less than 17 percent," he said.
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Although Pope Francis has catalysed the process, the synod is the culmination of a powerful grass-roots movement which has been under way for decades, Mr López says.
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In fact, wariness of Mr Maduro's new-found relationship with the holy see, and of the political dialogue that it catalysed, goes far beyond the world of pious Venezuela.
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A study of class, family and politics, Cuarón's excoriating look at his own upbringing and the nation that catalysed it manages to be both understated and grandiose; naturalistic and finely orchestrated.
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Comments from senior OPEC and non-OPEC officials suggesting they would consider raising output to compensate for lost production from Venezuela and sanctions on Iran catalysed a sharp fall in oil prices.
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Perhaps it's a testosterone spike catalysed by a large serving of the self-proclaimed "macho" peas, but these stanzas of freeform banter poetry encapsulate precisely why Nando's has become such a British phenomena.
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Moonfruit was sold to Gandi Group in 2005 where Wendy became Marketing Director but catalysed by high growth it was spun back out as a separate company, raising $2.25m from Stephens(US) in Sept 2010 to scale internationally.
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Misère: The Visual Representation of Misery in the 19th Century pinpoints a particular strand of misery, namely the societal sectors suffering from extreme poverty catalysed by the Industrial Revolution, and various methods by which artists have sought to capture it.
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"Just as the moonshot that John F. Kennedy proposed in the 1960s catalysed new technology such as the MRI scanner and satellite dishes, we want our Earthshot challenges to create a new wave of ambition and innovation around finding ways to help save the planet," the Earthshot Prize website reads.
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The latest bout of yuan weakness, catalysed by concerns over the brewing trade war and a slowing Chinese economy, has seen it shed 21.9 percent of its value against the dollar since the end of the first quarter of this year - its biggest 20.9-day fall since the market exchange rate was unified in 221.
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But even before the migrant crisis catalysed European commissioners into debating increased defence collaboration such as a unified pan-European coast guard, a February 2014 report by European civil liberties monitor Statewatch found how hundred of millions of euros from EU research funding had been awarded to drone projects that are subsidising Europe's defence and security industries.
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As Ocean drilled, cut and chiselled his way through a supply of building materials, it was suggested that the broadcast would act as a pre-roll for the release of his long-awaited Boys Don't Cry album – a claim that was then catalysed by the New York Times, who ran a story stating the album would be released last Friday.
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Enzyme-catalysed reversible reactions, such as protease-catalysed amide bond formation/hydrolysis reactions and the aldolase-catalysed aldol reactions, have also been applied to protein-directed DCC.
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It covered the research areas of catalysed reactions and catalysts.
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More reversible-deactivation radical polymerizations are known to be catalysed by copper.
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The Rh-catalysed hydroformylation of ethylene is conducted on industrial scale to provide propionaldehyde.
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The process is catalysed by metal oxides and is assumed to proceed via the imine.
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Likewise coupling reactions involving organomanganese halides are catalysed by Pd, Ni, Cu and Fe compounds.
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The acid-catalysed degradation of hemicellulose gives furfural, a precursor to synthetic polymers and to tetrahydrofuran.
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It is technology and innovation acting together, catalysed by creativity and art, to create the elixir vitae.
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The reaction catalysed is: :UDP-glucose + {(1,3)-beta-D-glucosyl}(N) = UDP + {(1,3)-beta-D-glucosyl}(N+1).
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Ryoo, R., et al. “Lanthanum-catalysed synthesis of microporous 3D graphene-like carbons in a zeolite template”, Nature, 2016.
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Apart from a catalysed version of the CB60 engine, the Canada-bound DeTomasos also received unique rectangular side-marker lights.
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Innovations in the drink industry, catalysed by requests for non-alcoholic drinks, include: drink plants, drink processing, and drink packing.
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"Metabolism of cerivastatin by human liver microsomes in vitro". Drug Metabolism and Dispersion, 25 (3): 321-331 Demethylation is catalysed by the enzymes CYP2C8 and CYP3A4, which generates a metabolite that is known as M-1 in the cerivastatin metabolite pathway. Hydroxylation is catalysed by CYP2C8, which generates the major active metabolite, M-23.
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In chemistry, metal-catalysed hydroboration is a reaction used in organic synthesis. It is one of several examples of homogeneous catalysis.
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Terthiophene is prepared by the nickel- or palladium- catalysed coupling reaction of 2,5-dibromothiophene with the Grignard reagent derived from 2-bromothiophene.
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4-Fluoro--threonine is an antibacterial produced by Streptomyces cattleya. It is formed by the fluorothreonine transaldolase catalysed transfer of fluoroacetaldehyde onto threonine.
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Both the acetylase and succinylase variant pathways use four enzyme catalysed steps, the aminotransferase pathway uses two enzymes, and the dehydrogenase pathway uses a single enzyme. These four variant pathways converge at the formation of the penultimate product, meso‑diaminopimelate, which is subsequently enzymatically decarboxylated in an irreversible reaction catalysed by diaminopimelate decarboxylase (DAPDC) (E.C 4.1.1.20) to produce L-lysine.
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Hydrogenation of HMF gives 2,5-bis(hydroxymethyl)furan. Acid-catalysed hydrolysis converts HMF into gamma-hydroxyvaleric acid and gamma- valerolactone, with loss of formic acid.
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J. Am. Chem. Soc. 1961, 83, 2159. The acid-catalysed process is dependent on a reaction between boronic acid and an acid, such as sulfuric acid. On the other hand, the base-catalysed process arises from a pre-equilibrium between boronic acid and hydroxide to form the corresponding boronate, this is usually followed by a rate-limiting reaction between boronate and water (acting as the proton source).
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This is a diagram of acid catalysed dehydration of ethanol to produce ethylene: upright=2.5 A more controlled elimination reaction requires the formation of the xanthate ester.
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In molecular biology 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase (OHCU decarboxylase) is an enzyme involved in purine catabolism. It catalyses the decarboxylation of 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) into S(+)-allantoin. It is the third step of the conversion of uric acid (a purine derivative) to allantoin. Step one is catalysed by urate oxidase and step two is catalysed by hydroxyisourate hydrolase.
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The first reaction is catalysed by ATP sulfurylase: :SO42− \+ ATP → APS + PPi The conversion of APS to PAPS is catalysed by APS kinase: :APS + ATP → PAPS + ADP Structure of adenosine 5'-phosphosulfate (APS). Reduction of APS leads to sulfite, which is further reduced to hydrogen sulfide, which is excreted. This process is called dissimilatory sulfate reduction. Reduction of PAPS, a more elaborated sulfate ester, leads also to hydrogen sulfide.
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The database was established in 2015 to replace the two discontinued databases Methods in Organic Synthesis () and Catalysts and Catalysed Reactions (. Methods in Organic Synthesis was an online database that was established in 1998 and updated weekly with the latest developments in organic synthesis. It was also available as a monthly print bulletin. Catalysts & Catalysed Reactions was a monthly current- awareness journal that was published from 2002 to 2014.
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It is prepared by the base-catalysed dimerization of diketene.Raimund Miller, Claudio Abaecherli, Adel Said, Barry Jackson. "Ketenes". In Ullmann's Encyclopedia of Industrial Chemistry. 2001, Wiley-VCH, Weinheim.
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1.8) and SDH activities, whereas in other organisms, such as bacteria and fungi, both of these enzymes are encoded by separate genes. The first step involves the LKR catalysed reduction of L-lysine in the presence of α-ketoglutarate to produce saccharopine, with NAD(P)H acting as a proton donor. Saccharopine then undergoes a dehydration reaction, catalysed by SDH in the presence of NAD+, to produce AAS and glutamate. AAS dehydrogenase (AASD) (E.
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Acrylates are industrially prepared by treating acrylic acid with the corresponding alcohol in presence of a catalyst. The reaction with lower alcohols (methanol, ethanol) takes place at 100–120 °C with acidic heterogeneous catalysts (cation exchanger). The reaction of higher alcohols (n-butanol, 2-ethylhexanol) is catalysed with sulfuric acid in homogeneous phase. Acrylates of even higher alcohols are obtainable by transesterification of lower esters catalysed by titanium alcoholates or organic tin compounds (e.g.
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The compound is catalysed by the enzyme to produce the same fluorescent product, resorufin. 1,3-dichloro-7-hydroxy-9,9-dimethylacridin-2(9H)-one (DDAO dye), fluorescent dye used for oligonucleotide labeling.
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When CO2 is released in the bundle sheath cells, pyruvate is regenerated, and the cycle continues. Though the reaction catalysed by PPDK is reversible, PEP is favoured as the product in biological conditions. This is due to the basic pH in the stroma, where the reaction occurs, as well as high concentrations of adenylate kinase and pyrophosphatase. Because these two enzymes catalyse exergonic reactions involving AMP, and disphosphate, respectively, they drive the PPDK-catalysed reaction forward.
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The majority of his works are held by the German State Library, and about 25% of those are in advanced stages of decay (American Libraries 2000). The rate at which the writing fades is based on several factors, such as proportions of ink ingredients, amount deposited on the paper, and paper composition (Barrow 1972:16). Corrosion is caused by acid catalysed hydrolysis and iron(II)-catalysed oxidation of cellulose (Rouchon- Quillet 2004:389). Treatment is a controversial subject.
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The economic benefits of metal-catalysed carbonylations, such as Reppe chemistry and hydroformylation, led to growth of the area. Metal carbonyl compounds were discovered in the active sites of three naturally occurring enzymes.
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If loxP sites are on different chromosomes it is possible for translocation events to be catalysed by Cre induced recombination. Two plasmids can be joined using the variant lox sites 71 and 66.
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The mechanism of protodeboronation was initially investigated by Kuivila in the 1960s, long before the discovery of the Suzuki reaction and the popularisation of boronic acids. Their studies focused on the protodeboronation of some substituted aromatic boronic acids in aqueous conditions, and they reported the presence of two distinct mechanisms; a general acid-catalysed and a specific base-catalysed mechanism.Kuivila, H. G.; Reuwer, J. F.; Mangravite, J. A. "Electrophilic Displacement Reactions. X. General Acid Catalysis in the Protodeboronation of Areneboronic Acids". Can.
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There are several ways in which ManNAc can be synthesised and three examples follow. # By aldolase treatment of sialic acid. to produce ManNAc and pyruvic acid. # By base catalysed epimerization of N-acetyl glucosamine.
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Levoglucosenone is a bridged, unsaturated heterocyclic ketone formed from levoglucosan by loss of two molecules of water. It is the major component produced during the acid-catalysed pyrolysis of cellulose, D-glucose, and levoglucosan.
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Acrylyl-CoA reductase (NADH) () is an enzyme with systematic name propanoyl- CoA:NAD+ oxidoreductase. This enzyme catalyses the following chemical reaction : propanoyl-CoA + NAD+ \rightleftharpoons acryloyl-CoA + NADH + H+ The reaction is catalysed in the opposite direction.
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The alkylation is catalysed by metal oxides: :C6H5OH + CH3OH → CH3C6H4OH + H2O Over-methylation gives xylenol. Many other production methods have been examined, including oxidative decarboxylation of salicylic acid, oxygenation of toluene, and hydrolysis of 2-chlorotoluene.
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When the specificity of enzyme was probed, it was found that it was highly selective against natural amino acids that were not phenylalanine, but was much more tolerant towards unnatural amino acids. Specifically, most amino acids were not catalysed, whereas the next most catalysed native amino acid was the structurally similar tyrosine, but at a thousandth as much as phenylalanine, whereas several unnatural amino acids where catalysed better than tyrosine, namely D-phenylalanine, β-cyclohexyl-L-alanine, 4-amino-L-phenylalanine and L-norleucine. One peculiar case of selected secondary activity are polymerases and restriction endonucleases, where incorrect activity is actually a result of a compromise between fidelity and evolvability. For example, for restriction endonucleases incorrect activity (star activity) is often lethal for the organism, but a small amount allows new functions to evolve against new pathogens.
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No territorial limits were imposed on any of the companies, encouraging export. Thus, he catalysed a vigorous offshore drive that resulted in Weldon International exports accounting for 55 per cent of Australia's total export of book products.
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His publications include the Methuen monograph "Elements of Pulse Circuits" (1955) translated into French and Spanish and papers on particle physics, relativity, wave energy and cosmology. Francis Farley presenting his novel "Catalysed Fusion" in the CERN Library. In 2012 he wrote a romantic novel, Catalysed Fusion, which illustrates life around the accelerators at CERN and in Geneva Farley signed more than 50 peer reviewed articles. His nuclear and particle physics related publications are indexed in INSPIRE-HEP The European Patent Office has registered 17 patents with Francis Farley as the inventor.
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Sir Hugh Stott Taylor (6 February 1890 – 17 April 1974) was an English chemist primarily interested in catalysis.Who Was Who, Published by A&C; Black Limited In 1925, in a landmark contribution to catalytic theory, Taylor suggested that a catalysed chemical reaction is not catalysed over the entire solid surface of the catalyst but only at certain 'active sites' or centres. He also developed important methods for procuring heavy water during World War II and pioneered the use of stable isotopes in studying chemical reactions.(1975) Chem. Brit.
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Plant lignans are polyphenolic substances derived from phenylalanine via dimerization of substituted cinnamic alcohols (see cinnamic acid), known as monolignols, to a dibenzylbutane skeleton 2. This reaction is catalysed by oxidative enzymes and is often controlled by dirigent proteins.
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In this way, it acts as an RNA translational inhibitor. The catalysed reaction is as follows: : NAD+ \+ peptide diphthamide \rightleftharpoons nicotinamide + peptide N-(ADP- D-ribosyl)diphthamide. The exotoxin A of Pseudomonas aeruginosa uses a similar mechanism of action.
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Later, book has details about formation of Maharashtra Navnirman Sena and contemporary history. Book, according to author, examines "identity politics, and the social, cultural and economic matrix that catalysed the formation of the Shiv Sena and the MNS from it".
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He left Crass in July 1984, after a concert in Aberdare, Wales.In Which Crass Voluntarily Blow Their Own - CD booklet. This catalysed the affirmation of Crass' consistently stated intention to split up in 1984, and the band stopped performing and recording.
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Cyclopentasilane can be made from diphenyldichlorosilane (C6H5)2SiCl2 reacting with lithium. This forms decaphenylcyclopentasilane. This reacts with aluminium chloride in benzene catalysed with hydrogen chloride to yield decachlorocyclopentasilane. Decachlorocyclopentasilane then has its chlorine replaced by hydrogen using lithium aluminium hydride.
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The cycle is composed of three enzyme-catalysed reactions. The first stage is the deamination of the purine nucleotide Adenosine monophosphate (AMP) to form inosine monophosphate (IMP), catalysed by the enzyme AMP deaminase: :AMP + H2O → IMP + NH4+ The second stage is the formation of adenylosuccinate from IMP and the amino acid aspartate, which is coupled to the energetically favourable hydrolysis of GTP, and catalysed by the enzyme adenylosuccinate synthetase: :Aspartate + IMP + GTP → Adenylosuccinate + GDP + Pi Finally, Adenylosuccinate is cleaved by the enzyme adenylosuccinate lyase to release fumarate and regenerate the starting material of AMP: :Adenylosuccinate → AMP + Fumarate A recent study conducted by Sridharan et al. (AJP Cell Physiology, 2008, 295:C29-C37) showed that activation of HIF-1α allows cardiomyocytes to sustain mitochondrial membrane potential during anoxic stress by utilizing fumarate produced by adenylosuccinate lyase as an alternate terminal electron acceptor in place of oxygen. This mechanism should help provide protection in the ischemic heart.
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In 1987, Atwal et al. reported a modification to the Biginelli reaction that consistently generated higher yields. Atul Kumar has reported first enzymatic synthesis for Biginelli reaction via yeast catalysed protocol in high yields. The reaction has also been reported via green methodologies.
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In the presence of the group 3 homoleptic catalyst Y[N(SiMe3)2]3, triphenylphosphonium methylide can be coupled with phenylsilane. This reaction produces H2 gas a by product, and forms a silyl-stabilised ylide. :Yttrium catalysed dehydrocoupling of triphenylphosphonium methylide and phenylsilane.
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They viewed paultan.org as a personal blog, and Paul Tan as a blogger. This image perception issue further catalysed the development of the Driven show, which finally materialised in early 2010, after the shooting process was completed in 2009. Driven Media Sdn. Bhd.
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Photobacterium phosphoreum or Vibrio phosphoreum is a Gram-negative bioluminescent bacterium living in symbiosis with marine organisms. It can emit bluish-green light (490 nm) due to a chemical reaction between FMN, luciferin and molecular oxygen catalysed by an enzyme called luciferase.
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Idealized mechanism for metal- catalysed hydrosilylation of an alkene. Hydrosilylation of alkenes represents a commercially important method for preparing organosilicon compounds. The process is mechanistically similar to the hydrogenation of alkenes. In fact, similar catalysts are sometimes employed for the two catalytic processes.
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Structure of the nickelacyclopentane Ni(bipyridine)(CH2)4. In organometallic chemistry, metallacyclopentanes are compounds with the formula LnM(CH2)4 (Ln = ligands, and M = metal). They are a type of metallacycle. Metallacyclopentanes are intermediates in some metal-catalysed reactions in homogeneous catalysis.
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One system from the experiment contained variants of AATE which catalysed the synthesis of themselves. This experiment demonstrated the possibility that autocatalysts could exhibit competition within a population of entities with heredity, which could be interpreted as a rudimentary form of natural selection.
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He told this to Everard Fraser. This clique was known as The Mutual Protection of Southeast China. Zhang's troops later became involved in politics. In 1911, the Wuchang garrison led the Wuchang Uprising, a coup against the local government that catalysed the nationwide Xinhai Revolution.
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In 2010, the ScS product range was expanded beyond upholstered furniture, to include dining and occasional furniture. The ScS product range was further expanded in 2012 to include flooring. The additions of these new products catalysed the rebranding of ScS as ‘Sofa Carpet Specialist’.
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This turn of events catalysed an uprising among the local Greek population, who declared the independence of Northern Epirus. The Autonomous Republic of Northern Epirus was thus proclaimed in Argyrokastro (Gjirokastër) on 28 February 1914, while a provisional government was formed under Georgios Christakis-Zografos.
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Many procedures have been described. Phenol reacts with benzenediazonium chloride to give a Solvent Yellow 7, a yellow-orange azo compound. The reaction is base-catalysed. :800px The related dye called aniline yellow is produced from the reaction of aniline and the diazonium salt.
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Glycolonitrile is produced by reacting formaldehyde with hydrogen cyanide under acidic conditions. This reaction is catalysed by base.Peter Pollak, Gérard Romeder, Ferdinand Hagedorn, Heinz-Peter Gelbke "Nitriles" Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. Glycolonitrile polymerizes under alkaline conditions above pH 7.0.
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C. Elschenbroich, Organometallics (2006) Wiley and Sons- VCH: Weinheim. Cis-dichlorobis(diethyl sulfide)platinum(II) and Karstedt’s catalyst (adduct of divinyltetramethyldisiloxane and chloroplatinic acid) also catalyse hydrosilylation. Many metallodendrimers have repeating units based on organoplatinum compounds. Idealized mechanism for metal-catalysed hydrosilylation of an alkene.
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Steroidogenesis, including corticosteroid biosynthesis. The corticosteroids are synthesized from cholesterol within the adrenal cortex. Most steroidogenic reactions are catalysed by enzymes of the cytochrome P450 family. They are located within the mitochondria and require adrenodoxin as a cofactor (except 21-hydroxylase and 17α-hydroxylase).
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Proline and its derivatives are often used as asymmetric catalysts in proline organocatalysis reactions. The CBS reduction and proline catalysed aldol condensation are prominent examples. In brewing, proteins rich in proline combine with polyphenols to produce haze (turbidity).K.J. Siebert, "Haze and Foam", Accessed July 12, 2010.
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In March of that year he conducted the posthumous premiere of Tchaikovsky's student overture The Storm. In 1897, he led the disastrous premiere of Rachmaninoff's Symphony No 1. This catalysed Rachmaninoff's three-year depression. The composer's wife later claimed that Glazunov seemed to be drunk at the time.
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A recent study has shown that the anthraquinone component of lac dye also possess antineoplastic or anticancer effects. It is proposed that lac insects employ polyketide pathway catalysed by polyketide synthase to produce laccaic acid D, a common precursor molecule for the biosynthesis of other lac dye constituents.
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Crotonyl-CoA carboxylase/reductase (, CCR, crotonyl-CoA reductase (carboxylating)) is an enzyme with systematic name (2S)-ethylmalonyl-CoA:NADP+ oxidoreductase (decarboxylating). This enzyme catalyses the following chemical reaction : (2S)-ethylmalonyl-CoA + NADP+ \rightleftharpoons (E)-but-2-enoyl- CoA + CO2 \+ NADPH + H+ The reaction is catalysed in the reverse direction.
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Arenavirus replication cycle. The glycoprotein (GP) is synthesised as a precursor molecule. It is cleaved into three parts - GP1, GP2 and a stable signal peptide (SSP). These reactions are catalysed by cellular signal peptidases and the cellular enzyme Subtilisin Kexin Isozyme-1 (SKI-1)/Site-1 Protease (S1P).
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Additionally, various complications between Honda and the Oriental Group had also catalysed Honda's decision to establish a direct presence in the Malaysian market. Under the DRB-Oriental-Honda joint venture, Oriental Holdings would concentrate on the marketing and sales of Honda vehicles, while Honda would handle assembly operations.
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The essay propelled Hensley towards native American activism helped begin the process of going to his hometown of Kotzebue to begin to start claiming back the land for natives. The essay also catalysed the formation of what is now known as the Alaskan Federation of Natives in 1966.
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The Rhodesian Bush War from 1964-1979, a fifteen-year guerrilla war, catalysed the shift in power from British colonial rule to de jure sovereignty in 1980.Kalley, Jacqueline Audrey (1999). Southern African Political History: A chronological of key political events from independence to mid-1997. pp 711-713. .
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Martin Laroche, born William Henry Silvester, (15 September 1814 – 10 November 1886) was an early English professional photographer who successfully challenged William Fox Talbot's patent on the calotype and effected a liberalisation in professional practice, research and development that catalysed the development of photography in the nineteenth century.
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When used as a reagent in organic synthesis to convert carboxylic acids to their methyl esters, trimethylsilyldiazomethane undergoes acid-catalysed methanolysis, forming diazomethane in situ. A similar hydrolysis reaction may take place when trimethylsilyldiazomethane comes into contact with water on the surface of a human lung. Trimethylsilyldiazomethane is nonexplosive.
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Ethyl acrylate is produced by acid-catalysed esterification of acrylic acid, which in turn is produced by oxidation of propylene. It may also be prepared from acetylene, carbon monoxide and ethanol by a Reppe reaction. Commercial preparations contain a polymerization inhibitor such as hydroquinone, phenothiazine, or hydroquinone ethyl ether.
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Rhododendrol is metabolised via tyrosinase-catalysed oxidation. Therefore, the enzyme tyrosinase is necessary for the oxidation of rhododendrol. Tyrosinase regularly plays an essential role in the production of melanocytes called the melanogenesis. After oxidation of rhododendrol by the tyrosinase enzyme, several kinds of phenols and catechols are formed.
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Polymerisation of coniferyl alcohol to lignin. The reaction has two alternative routes catalysed by two different oxidative enzymes, peroxidases or oxidases. An oxidative enzyme is an enzyme that catalyses an oxidation reaction. Two most common types of oxidative enzymes are peroxidases, which use hydrogen peroxide, and oxidases, which use molecular oxygen.
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Higher boiling solvents have the advantage of a lower process pressure. This is weighed against the more difficult solvent recovery by distillation.Sarkanen, KV, Acid-catalysed delignification of lignocellulosics in organic solvents, in Progress in Biomass Conversion, K V Sarkanen and D A Tillman, Editors. (1980), Academic Press. p. 127-144.
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The crisis caused by the outbreak catalysed the city's sanitation process. Telephone lines were laid to help co-ordinate anti-plague operations. Regulations for building new houses with proper sanitation facilities came into effect. A health officer was appointed and the city divided into four wards for better co-ordination.
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Again, water can be used as a solvent, and high yields can be achieved under mild conditions. Nitro compounds are common in pharmaceuticals, explosives, dyes, and plastics. As for carbon compounds, catalysed Michael additions and aldol reactions can be used. For aromatic nitro compounds, synthesis is via a substitution reaction.
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Dioxane is produced by the acid-catalysed dehydration of diethylene glycol, which in turn is obtained from the hydrolysis of ethylene oxide. In 1985, the global production capacity for dioxane was between 11,000 and 14,000 tons. In 1990, the total U.S. production volume of dioxane was between 5,250 and 9,150 tons.
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Isocyanides have also been shown to be a useful reagent in palladium catalysed reactions with a wide variety of compounds being formed using this method. The α position of isocyanides have substantial acidity. For example, benzyl isocyanide has a pKa of 27.4. In comparison, benzyl cyanide has a pKa of 21.9.
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The major industrial use of maleic acid is its conversion to fumaric acid. This conversion, an isomerization, is catalysed by a variety of reagents, such as mineral acids and thiourea. Again, the large difference in water solubility makes fumaric acid purification easy. The isomerization is a popular topic in schools.
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The butanol–hydrochloric acid–iron assayAcid butanol assy for proanthocyanidins. by Ann E. Hagermann, 2002 (article) (Porter assay) is a colorimetric assay. It is based on acid catalysed oxidative depolymerization of condensed tannins into corresponding anthocyanidins. The method has also been used for determination of bound condensed tannins, but has limitations.
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GGC is synthesized from L-glutamic acid and L-cysteine in the cytoplasm of virtually all cells in an adenosine triphosphate (ATP) requiring reaction catalysed by the enzyme glutamate-cysteine ligase (GCL, EC 6.3.2.2; formerly γ-glutamylcysteine synthetase). The production of GGC is the rate limiting step in glutathione synthesis.
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Priso a Doo, also known as Preshaw, Preese, and possibly Peter, was a Duala ruler who lived on the Wouri River of the Cameroons in the late 18th century. His violent behaviour lost him his birthright and catalysed the split of the Duala people into rival Bell and Akwa sublineages.
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Two used Accu-Chek test strips. The lower one has had the cover peeled off to show the circuit. Many glucose meters employ the oxidation of glucose to gluconolactone catalyzed by glucose oxidase (sometimes known as GOx). Others use a similar reaction catalysed instead by another enzyme, glucose dehydrogenase (GDH).
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This first stage is catalysed by transposase. The plasmid containing the transposon (the donor plasmid) fuses with a host plasmid (the target plasmid). In the process, the transposon and a short section of host DNA are replicated. The end product is a 'cointegrate' plasmid containing two copies of the transposon.
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Benzotrichloride is produced by the free radical chlorination of toluene, catalysed by light or radical initiators such as dibenzoyl peroxide. Two intermediates are observed: : C6H5CH3 \+ Cl2 → C6H5CH2Cl + HCl : C6H5CH2Cl + Cl2 → C6H5CHCl2 \+ HCl : C6H5CHCl2 \+ Cl2 → C6H5CCl3 \+ HCl After synthesis the product is checked on purity and the benzal chloride is discarded.
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This cycle occurs in Skeletal muscle myocyte's cytosolic compartment. This reaction helps to dispose AMP produced after following reaction. :ATP → ADP + Pi (Utilisation of ATP for Muscle contraction) 2 ADP → ATP + AMP (Catalysed by Adenylyl kinase/Myokinase) Purine nucleotide cycle occurs during strenuous exercise, fasting or starvation when ATP reservoirs run low.
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The professional career of Lewis catalysed due to the rapid rise of Jeff Fenech. This in turn caused Jeff Harding to relocate from Grafton to train under him and Russian World Amateur Champion Kostya Tszyu to turn professional under Lewis’ tutelage. These accreditations prompted several fighters to also be trained by Lewis.
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Diacetyl reductase ((R)-acetoin forming) (, (R)-acetoin dehydrogenase) is an enzyme with systematic name (R)-acetoin:NAD+ oxidoreductase. This enzyme catalyses the following chemical reaction : (R)-acetoin + NAD+ \rightleftharpoons diacetyl + NADH + H+ The reaction is catalysed in the reverse direction. This activity is usually associated with butanediol dehydrogenase activity (EC 1.1.1.4 or EC 1.1.1.76).
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Diacetyl reductase ((S)-acetoin forming) (, (S)-acetoin dehydrogenase) is an enzyme with systematic name (S)-acetoin:NAD+ oxidoreductase. This enzyme catalyses the following chemical reaction : (S)-acetoin + NAD+ \rightleftharpoons diacetyl + NADH + H+ The reaction is catalysed in the reverse direction. This activity is usually associated with butanediol dehydrogenase activity (EC 1.1.1.4 or EC 1.1.1.76).
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Thus the overall reaction catalysed by photosystem I is: :Pc(Cu+) + Fd[ox] \+ hν -> Pc(Cu2+) + Fd[red] The cooperation between photosystems I and II creates an electron flow from H2O to NADP+. This pathway is called the 'Z-scheme' because the redox diagram from P680 to P700 resembles the letter z.
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Archaeosine synthase (, ArcS, TgtA2, MJ1022 (gene), glutamine:preQ0-tRNA amidinotransferase) is an enzyme with systematic name L-glutamine:7-cyano-7-carbaguanine aminotransferase. This enzyme catalyses the following chemical reaction : L-glutamine + 7-cyano-7-carbaguanine15 in tRNA + H2O \rightleftharpoons L-glutamate + archaeine15 in tRNA In Euryarchaeota the reaction is catalysed by ArcS.
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In July 1991 a luxurious "Serie Speciale" variant of the 990 was introduced, also offered with an available canvas-roof. The 990 Serie Speciale featured an alcantara interior by Missoni. In 1992, catalysed versions of both Innocenti Small versions entered the market. These versions had marginally lower power (see table) and top speeds.
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Cericlamine synthesis: Arylation of methacrylic acid with a diazonium salt of 3,4-dichloroaniline (or 3,4-dichloro-benzenediazonium salt), is carried out according to the Meerwein reaction catalysed by a metallic halide. For the next step, the halide is displaced by dimethylamine, then esterification is performed, followed by reduction with a metal hydride.
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Fluoroacetone is used as a catalyst to study the kinetics of the ketone-catalysed decomposition of peroxymonosulfuric acid (Caro's acid). It is also a precursor material for the production of higher fluoroketones. Fluoroacetone has not been used as a lachrymatory substance in contrast to other halogenated acetone derivatives, such as bromoacetone or chloroacetone.
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He then worked at the Queensland Museum from 1945, rising to become director in 1963, the year of his death. It was his controversial action in shooting a scarlet robin during the Royal Australasian Ornithologists Union (RAOU) campout in Marlo, Victoria in 1935 that catalysed change in the RAOU's attitude to collecting.
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GPAT4 is involved in the biosynthesis of triglycerides. The majority of triglycerides are synthesised from glycerol 3-phosphate (G3P) via the addition of three fatty acyl-CoA substrates, which are made from fatty acids. The first of these additions is catalysed by G3P acyltransferases (GPATs: EC 2.3.1.15), including GPAT4, yielding lysophosphatidic acid.
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The parent metallacyclopentadiene has the formula LnM(CH)4. Most arise from the coupling of two alkynes at a low valent metal centers such as derivatives of Co(I) and Zr(II). Late metal derivatives (Co, Ni) are intermediates in the metal-catalysed trimerization of alkynes to arenes. Early metal derivatives, i.e.
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Vinylsulfonic acid may also be grafted to polymeric supports (e.g. polystyrene) to give highly acidic ion exchangers, which used as catalysts for esterification and Friedel-Crafts acylations.T. Okayasu, K. Saito, H. Nishide, M.T W. Hearn: Poly(vinylsulfonic acid)-grafted solid catalysts: new materials for acid-catalysed organic synthetic reactions. In: Green Chem.
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Carbon-based life originates from carboxylation that couples atmospheric carbon dioxide to a sugar. The process is usually catalysed by the enzyme RuBisCO. Ribulose-1,5-bisphosphate carboxylase/oxygenase, the enzyme that catalyzes this carboxylation, is possibly the single most abundant protein on Earth. The Calvin cycle showing the carboxylation of ribulose-1,5-bisphosphate.
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Proposed early steps in the vanadium-catalyzed oxidation of naphthalene to phthalic anhydride, with V2O5 represented as a molecule vs its true extended structure. Maleic anhydride is produced by the V2O5-catalysed oxidation of butane with air: :C4H10 \+ 4 O2 → C2H2(CO)2O + 8 H2O Maleic anhydride is used for the production of polyester resins and alkyd resins.. Phthalic anhydride is produced similarly by V2O5-catalysed oxidation of ortho-xylene or naphthalene at 350–400 °C. The equation is for the xylene oxidation: :C6H4(CH3)2 \+ 3 O2 → C6H4(CO)2O + 3 H2O Phthalic anhydride is a precursor to plasticisers, used for conferring pliability to polymers. A variety of other industrial compounds are produced similarly, including adipic acid, acrylic acid, oxalic acid, and anthraquinone.
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Whereas the α-aminoadipate (AAA) pathway is part of the glutamate biosynthetic family. The DAP pathway is found in both prokaryotes and plants and begins with the dihydrodipicolinate synthase (DHDPS) (E.C 4.3.3.7) catalysed condensation reaction between the aspartate derived, L-aspartate semialdehyde, and pyruvate to form (4S)-4-hydroxy-2,3,4,5-tetrahydro-(2S)-dipicolinic acid (HTPA).
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In biology thiyl radicals are responsible for the formation of the deoxyribonucleic acids, building blocks for DNA. This conversion is catalysed by ribonucleotide reductase (see figure). Thiyl intermediates also are produced by the oxidation of glutathione, an antioxidant in biology. Thiyl radicals (sulfur-centred) can transform to carbon-centred radicals via hydrogen atom exchange equilibria.
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The Li-arene reacted with water or deuterium to produce the dehalogenated product.Ramón, D.; Yus, M. Masked lithium bishomoenolates: Useful intermediates in organic synthesis, J. Org. Chem. 1991, 56, 3825-3831.Guijarro, A.; Ramón, D.; Yus, M. Naphthalene- catalysed lithiation of functionalized chloroarenes: regioselective preparation and reactivity of functionalized lithioarenes, Tetrahedron, 1993, 49, 469-482.
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Fullerenes can be hydroxylated to fullerenols or fullerols. Water solubility depends on the total number of hydroxyl groups that can be attached. One method is fullerene reaction in diluted sulfuric acid and potassium nitrate to C60(OH)15. Another method is reaction in diluted sodium hydroxide catalysed by TBAH adding 24 to 26 hydroxyl groups.
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The corticosteroids are synthesized from cholesterol within the zona glomerulosa of adrenal cortex. Most steroidogenic reactions are catalysed by enzymes of the cytochrome P450 family. They are located within the mitochondria and require adrenodoxin as a cofactor (except 21-hydroxylase and 17α-hydroxylase). Aldosterone and corticosterone share the first part of their biosynthetic pathways.
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However, it can form artifacts which complicate spectral interpretation. Such artifacts are usually the trimethylsilylmethyl esters, RCO2CH2SiMe3, formed when insufficient methanol is present. Acid-catalysed methanolysis is necessary to achieve near- quantitative yields of the desired methyl esters, RCO2Me. The compound is a reagent in the Doyle-Kirmse reaction with allyl sulfides and allyl amines.
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Epimerisation is catalysed by one enzyme, the GlcA C5 epimerase or heparosan-N-sulfate-glucuronate 5-epimerase (). This enzyme epimerises GlcA to iduronic acid (IdoA). Substrate recognition requires that the GlcN residue linked to the non-reducing side of a potential GlcA target be N-sulfated. Uronosyl-2-O-sulfotransferase (2OST) sulfates the resulting IdoA residues.
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The initial enzymatic reactions take place. In the case of methylation, this is a short step that results in the methylation of cytosine to 5-methylcytosine. Stage 3: Base excision DNA repair. The intermediate products of demethylation are catalysed by specific enzymes of the base excision DNA repair pathway that finally restore cystosine in the DNA sequence.
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In the periplasm, FeEnt is bound by FepB and passed to the integral inner membrane proteins FepG and FepD through active transport, with the energy provided by ATP hydrolysis catalysed by cytoplasmic FepC. In the cytoplasm, the Fes enterobactin esterase hydrolyses and this cleaves enterobactin, releasing Fe3+ which will subsequently be reduced by the same protein, Fes, to Fe2+.
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The contribution of these five states accounted for 71.8% of the total value of construction work in Malaysia. The expansion of the construction industry has been catalysed by major capital expenditure projects, and a key factor has been the government's Economic Transformation Programme (ETP) and public-private partnership (PPP) mega-projects like Tun Razak Exchange, KVMRT and Iskandar Malaysia.
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In the liver artemisinin is converted to different inactive metabolites such as deoxyartemisinin, deoxydihydroartemisinin, crystal 7, and 9,10-dihydrodeoxyartemisinin. The metabolites have lost the endoperoxide group and become ineffective. The reaction is catalysed by an enzyme CYP2B6, while another enzyme CYP3A4 acts as a secondary catalyst. In the absence of CYP2B6, CYP3A4 becomes the primary enzyme.
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A Euplokamis comb jelly is bioluminescent. Bioluminescence is the production of light, such as by the photophores of marine animals, and the tails of glow-worms and fireflies. Bioluminescence, like other forms of metabolism, releases energy derived from the chemical energy of food. A pigment, luciferin is catalysed by the enzyme luciferase to react with oxygen, releasing light.
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Yus, M.; Ramón, D. Arene-catalysed lithiation reactions with lithium at low temperature, Chem. Comm. 1991, 398-400. The major drawback of using lithium naphthalene catalysts is that it is hard to separate from the reaction mixture because naphthalene adsorbs on surface of arene substrates. In polymer chemistry, sodium metal has been used for dehalogenation process.
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Formylation refers to any chemical processes in which a compound is functionalized with a formyl group (-CH=O). In organic chemistry, the term is most commonly used with regards to aromatic compounds (for example the conversion of benzene to benzaldehyde in the Gattermann–Koch reaction). In biochemistry the reaction is catalysed by enzymes such as formyltransferases.
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Almost all amine oxides are prepared by the oxidation of either tertiary aliphatic amines or aromatic N-heterocycles. Hydrogen peroxide is the most common reagent both industrially and in academia, however peracids are also important. More specialised oxidising agents can see niche use, for instance Caro's acid or mCPBA. Spontaneous or catalysed reactions using molecular oxygen are rare.
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Diagram of a catalytic reaction, showing the energy niveau depending on the reaction coordinate. For a catalysed reaction, the activation energy is lower. In chemistry, a reaction coordinate is an abstract one-dimensional coordinate which represents progress along a reaction pathway. It is usually a geometric parameter that changes during the conversion of one or more molecular entities.
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The Timbarra Gold Mine was a highly controversial gold mine located on the Timbarra Plateau, at the head waters of the Clarence River, near Tenterfield, New South Wales, Australia. The gold ore body consisted of a greisen type granite. The protracted controversy attracted national and international attention, and catalysed an anti-cyanide extraction campaign in Australia.
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It uses a fully catalysed stainless steel exhaust system with active bypass valves. The car uses an updated Touchtronic II six- speed automatic gearbox. It was the first Aston Martin model to be available with launch control. The combined space of cabin and a boot that, at 368 litres, is more than 60% larger than that of the DBS.
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Alkenes engage in an acid catalysed hydration reaction using concentrated sulfuric acid as a catalyst that gives usually secondary or tertiary alcohols. The hydroboration- oxidation and oxymercuration-reduction of alkenes are more reliable in organic synthesis. Alkenes react with NBS and water in halohydrin formation reaction. Amines can be converted to diazonium salts, which are then hydrolyzed.
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The initial enzymatic reactions take place. In the case of methylation, this is a short step that results in the methylation of cytosine to 5-methylcytosine. Stage 3: Base excision DNA repair. The intermediate products of demethylation are catalysed by specific enzymes of the base excision DNA repair pathway that finally restore cystosine in the DNA sequence.
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Here it is degraded by reaction with hydroxyl radicals and oxygen. CH2FCH2F + OH → CH2FCHF + H2O CH2FCHF + O2 → CH2FCHFO2 peroxy radical CH2FCHFO2 \+ NO → CH2FCHFO alkoxy radical When catalysed by chlorine atoms and oxidised by nitrogen oxides the end product is HCOF which can decompose further to HF and CO. The halflife in air is between 140 and 180 days.
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GGC occurs in human plasma in the range of 1 – 5 µM and intracellularly at 5 – 10 µM. The intracellular concentration is generally low because GGC is rapidly bonded with a glycine to form glutathione. This second and final reaction step in glutathione biosynthesis is catalysed by the activity of the ATP dependent glutathione synthetase enzyme.
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Early proposals for the mechanism of tryptophan oxidation were presented by Sono and Dawson. This suggested a base- catalysed abstraction mechanism, involving only the ferrous (FeII) heme. It is assumed that TDO and IDO react by the same mechanism, although there is no concrete evidence for that. In IDO, a ferryl heme (FeIV) has been identified during turnover.
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Since Peter Waldo's Franco-Provençal translation of the New Testament in the late 1170s, and Guyart des Moulins' Bible Historiale manuscripts of the Late Middle Ages, there have been innumerable vernacular translations of the scriptures on the European continent, greatly aided and catalysed by the development of the printing press, first invented by Johannes Gutenberg in the late 1430s.
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In 1962, Smidt published work on the palladium- catalysed oxidation of alkenes to carbonyl groups. In this work, it was determined that the palladium catalyst activated the alkene for the nucleophilic attack of hydroxide.Smidt, J., Hafner, W., Jira, R., Sieber, R., Sedlmeier, J. and Sabel, A. (1962), Olefinoxydation mit Palladiumchlorid- Katalysatoren. Angewandte Chemie, 74: 93–102.
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Examples of monomers that can be incorporated are methyl vinyl ketones methyl acrylate and acrylonitrile. Illustrative metallocene-based coordination catalysts Kaminsky catalysts are based on metallocenes of group 4 metals (Ti, Zr, Hf) activated with methylaluminoxane (MAO). Polymerizations catalysed by metallocenes occur via the Cossee–Arlman mechanism. The active site is usually anionic but cationic coordination polymerization also exists.
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The VPg protein interacts with eukaryotic initiation factor 4E (eIF4E). This interaction appears to be essential to viral infectivity. Two proteinases, P1 and the helper component proteinase (HC) catalyse only autoproteolytic reactions at their respective C termini. The remaining cleavage reactions are catalysed by either trans-proteolytic or autoproteolytic mechanisms by the small nuclear inclusion protein (NIa-Pro).
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The rhamnose can then be used in the synthesis of rhamnolipids by RhlB and RhlC. The complete pathway of biosynthesis of rhamnolipids has not been confirmed. In summary, mono- and di- rhamnolipids are produced by sequential rhamnosyltransferase reactions catalysed by RhlB and RhlC respectively. The substrate for RhlB is the fatty acid moiety of the detergent, produced by RhlA.
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The cleavage is catalysed by a protease within the C-terminal domain. During the reaction a cholesterol molecule is added to the C-terminus of SHH-N. Thus the C-terminal domain acts as an intein and a cholesterol transferase. Another hydrophobic moiety a palmitate is added to the alpha- amine of N-terminal cysteine of SHH-N.
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In each case, both of the NADH molecules generated by glycolysis are reoxidized to NAD+. Each alternative pathway requires a different key enzyme in E. coli. After the variable amounts of different end products are formed by these pathways, they are secreted from the cell. The conversion of pyruvate to lactate is catalysed by the enzyme lactate dehydrogenase.
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In the ensuing chaos, four students were killed. Catalysed by the student deaths, mass violence began almost simultaneously throughout Jakarta the following day. The Matahari department store in the eastern district of Jatinegara and Yogya Plaza in Klender were barricaded and deliberately torched. It was estimated that at least a thousand people died inside the buildings during the fires.
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These phenols and catechols together form ortho- quinones (o-quinones) . Presence of o-quinones can lead to cytotoxicity via the production of reactive oxygen species (ROS) or by the binding to enzymes or DNA . When rhododendrol is metabolised via the tyrosinase-catalysed oxidation RD-quinone will be formed . This formation gives rise to the formation of secondary quinones.
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Acid–base- catalysed hydrolyses are very common; one example is the hydrolysis of amides or esters. Their hydrolysis occurs when the nucleophile (a nucleus-seeking agent, e.g., water or hydroxyl ion) attacks the carbon of the carbonyl group of the ester or amide. In an aqueous base, hydroxyl ions are better nucleophiles than polar molecules such as water.
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This figure depicts how Floxing is used in scientific research for spatial and temporal control of gene expression. In genetics, floxing refers to the sandwiching of a DNA sequence (which is then said to be floxed) between two lox P sites. The terms are constructed upon the phrase "flanking/flanked by LoxP". Recombination between LoxP sites is catalysed by Cre recombinase.
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Flanders (and Belgium as a whole) saw some of the greatest loss of life on the Western Front of the First World War, in particular from the three battles of Ypres. The war strengthened Flemish identity and consciousness. The occupying German authorities took several Flemish-friendly measures. More importantly, French-speaking officers on the front catalysed Flemish desire for emancipation.
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HIF is synthesized constitutively, and hydroxylation of at least one of two critical proline residues mediates their interaction with the von Hippel Lindau E3 ubiquitin ligase complex, which targets them for rapid degradation. This reaction is catalysed by prolyl 4-hydroxylases. Fumarate and succinate have been identified as potent inhibitors of prolyl hydroxylases, thus leading to the stabilisation of HIF.
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These modified compounds are then conjugated to polar compounds in phase II reactions. These reactions are catalysed by transferase enzymes such as glutathione S-transferases. Finally, in phase III, the conjugated xenobiotics may be further processed, before being recognised by efflux transporters and pumped out of cells. Drug metabolism often converts lipophilic compounds into hydrophilic products that are more readily excreted.
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In 1999 Lemal and others investigated an equilibrium between a dibenzotetraazafulvalene derivative and its carbene. These studies led Böhm & Herrmann to conclude in 2000 that "the Wanzlick equilibrium between a tetraaminoethylene and its corresponding carbene did exist". This notion was confirmed in 2010 by Kirmse. Others subsequently showed that unhindered diaminocarbenes form dimers by acid-catalysed dimerisation as shown in the Lemal.
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The overall reaction is: :CO2 \+ Ca(OH)2 → CaCO3 \+ H2O + heat (in the presence of water) Each mole of CO2 (44 g) reacting with calcium hydroxide produces one mole of water (18 g). The reaction can be considered as a strong-base-catalysed, water-facilitated reaction.Joseph Pelc (1923). Process of treating lime-containing materials. Application filed August 30, 1921. Serial No. 496,963.
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In animals and humans, after ingestion, natural phenols become part of the xenobiotic metabolism. In subsequent phase II reactions, these activated metabolites are conjugated with charged species such as glutathione, sulfate, glycine or glucuronic acid. These reactions are catalysed by a large group of broad-specificity transferases. UGT1A6 is a human gene encoding a phenol UDP glucuronosyltransferase active on simple phenols.
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Moreover, while the Wurtzite substance's decomposition is strongly base catalysed, whereas the solidified diatomic species is not strongly affected at all. Dilts distinguishes between the two copper hydrides as the 'insoluble-' and 'soluble copper hydrides'. The soluble hydride is susceptible to pyrolysis under vacuum and proceeds to completion under 100 °C. Amorphous copper hydride is also produced by anhydrous reduction.
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Overall reaction catalysed by thymidine kinase. After creation of the dTMP molecule, another kinase, thymidylate kinase, can act upon dTMP to create the diphosphate form, dTDP. Nucleoside diphosphate kinase catalyzes production of thymidine triphosphate, dTTP, which is used in DNA synthesis. Because of this, thymidine kinase activity is closely correlated with the cell cycle and used as a tumor marker in clinical chemistry.
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Enzymes must bind their substrates before they can catalyse any chemical reaction. Enzymes are usually very specific as to what substrates they bind and then the chemical reaction catalysed. Specificity is achieved by binding pockets with complementary shape, charge and hydrophilic/hydrophobic characteristics to the substrates. Enzymes can therefore distinguish between very similar substrate molecules to be chemoselective, regioselective and stereospecific.
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Bis(diphenylphosphinoethyl)phenylphosphine is called triphos, is a linear tridentate triphosphine. It is prepared by the free-radical-catalysed addition of phenylphosphine to vinyldiphenylphosphine:"Synthesis of Polytertiary Phosphines and ‘Mixed’ Phosphorus–Sulphur and ‘Mixed’ Phosphorus–Nitrogen Polydentate Ligands via Free-Radical Catalysis" Daniel L. DuBois, William H. Myers and Devon W. Meek J. Chem. Soc., Dalton Trans., 1975, 1011-1015.
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In catalysed photolysis, light is absorbed by an adsorbed substrate. In photogenerated catalysis, the photocatalytic activity (PCA) depends on the ability of the catalyst to create electron–hole pairs, which generate free radicals (e.g. hydroxyl radicals: •OH) able to undergo secondary reactions. Its practical application was made possible by the discovery of water electrolysis by means of titanium dioxide (TiO2).
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When FSSF3 dissociates, the Fcis atom forms a new bond to the Stop atom, and the S-S bond breaks. As a gas, at ambient and totally clean conditions, FSSF3 decomposes with a half life of about 10 hours. Disproportionation to SSF2 and SF4 catalysed by metal fluorides can take place in under one second. However it is indefinitely stable at -196 °C.
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1,1′-Bi-2-naphthol (BINOL) is an organic compound that is often used as a ligand for transition-metal catalysed asymmetric synthesis. BINOL has axial chirality and the two enantiomers can be readily separated and are stable toward racemisation. The specific rotation of the two enantiomers is ±35.5° (c = 1 in THF). BINOL is a precursor for another chiral ligand called BINAP.
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Richard Gustav Müller (17 July 1903 - 7 July 1999) was a German chemist. He and Eugene G. Rochow independently discovered the direct process of organosilicon compounds in 1941. That synthesis, also known as the Müller- Rochow process is the copper-catalysed reaction of chloromethane with silicon. Müller was awarded the National Prize of East Germany in 1952 for his work.
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Zinc oxide eugenol (ZOE) is a material created by the combination of zinc oxide and eugenol contained in oil of cloves. An acid-base reaction takes place with the formation of zinc eugenolate chelate. The reaction is catalysed by water and is accelerated by the presence of metal salts. ZOE can be used as a dental filling material or dental cement in dentistry.
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The mechanism of action of rhododendrol has been investigated in multiple studies which revealed that RD competes with tyrosine for hydroxylation by tyrosinase and interferes with melanin synthesis . First, RD is catalysed by tyrosinase to produce toxic metabolites as RD-cyclic catechol. These reactive metabolites cause damage to the melanocytes. There is still uncertainty, however, how the metabolites result in melanocyte damage.
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Prolidase deficiency is the result of mutations on the PEPD gene, located on chromosome 19 and coding for the prolidase Enzyme, also known as peptidase-D. At least 19 different mutations in the PEPD gene have been identified in individuals affected by the disorder. Prolidase-catalysed cleavage of a dipeptide to yield proline and, in this case, alanine. Prolidase deficiency has an autosomal recessive pattern of inheritance.
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This reagent reacts with toluene to form the red- orange compound benzyl potassium (KCH2C6H5). Evidence for the formation of heavy alkali metal-organic intermediates is provided by the equilibration of cis-2-butene and trans-2-butene catalysed by alkali metals. The isomerization is fast with lithium and sodium, but slow with the higher alkali metals. The higher alkali metals also favor the sterically congested conformation.
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3-Hydroxypropionaldehyde is formed by the condensation of acetaldehyde and formaldehyde. This reaction, when conducted in the gas-phase, was the basis for a now obsolete industrial route acrolein: :CH3CHO + CH2O → HOCH2CH2CHO :HOCH2CH2CHO → CH2=CHCHO + H2O Presently 3-hydroxypropionaldehyde is an intermediate in the production of pentaerythritol. Reuterin is an intermediate in the metabolism of glycerol to 1,3-propanediol catalysed by the coenzyme B12-dependent glycerol dehydratase.
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In prokaryotes, the mechanism of oxidative folding is best studied in Gram-negative bacteria. This process is catalysed by protein machinery residing in the periplasmic space of bacteria. The formation of disulfide bonds in a protein is made possible by two related pathways: an oxidative pathway, which is responsible for the formation of the disulfides, and an isomerization pathway that shuffles incorrectly formed disulfides.
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Atkins, P. W.; Overton, T. L.; Rourke, J. P.; Weller, M. T.; Armstrong, F. A., 2010, Shriver and Atkins' Inorganic Chemistry 5th Edn., pp. 65, 75, 99f, 268, 271, 277, 287, 356, 409, Oxford, OXF, GBR: Oxford University Press, , see , accessed 8 July 2015. An analogous sequence of events describes other kinds of atom-transfer reactions including hydrogenation and hydrodesulfurization catalysed by solid catalysts.
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Decaprenylphospho-beta-D-erythro-pentofuranosid-2-ulose 2-reductase (, decaprenylphospho-beta-D-ribofuranose 2'-epimerase, Rv3791, DprE2) is an enzyme with systematic name trans,octacis-decaprenylphospho-beta-D- arabinofuranose:NAD+ 2-oxidoreductase. This enzyme catalyses the following chemical reaction : trans,octacis-decaprenylphospho-beta-D-arabinofuranose + NAD+ \rightleftharpoons trans,octacis-decaprenylphospho-beta-D-erythro- pentofuranosid-2-ulose + NADH + H+ The reaction is catalysed in the reverse direction.
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Hydrogenation produces organoborane compounds that react with a variety of reagents to produce useful compounds, such as alcohols, amines, alkyl halides. The most widely known reaction of the organoboranes is oxidation to produce alcohols typically by hydrogen peroxide. This type of reaction has promoted research on hydroboration because of its mild condition and a wide scope of tolerated alkenes. Another research subtheme is metal-catalysed hydroboration.
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Acetalisation is the organic reaction that involves the formation of an acetal (or ketals). One way of acetal formation is the nucleophilic addition of an alcohol to a ketone or an aldehyde. Acetalisation is often used in organic synthesis to create a protecting group because it is a reversible reaction. Acetalisation is acid catalysed with elimination of water; acetals do not form under basic conditions.
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Cyclic and benzylic ketones are reduced to their respective alcohols. Barbier- type reaction catalysed by Cp2TiCl Bis(cyclopentadienyl)titanium(III) chloride also effects both Pinacol and McMurry couplings of aldehydes and ketones. Barbier-type reactivity is observed between aldehydes or ketones and allyl electrophiles under catalytic conditions. The proposed mechanism involves titanium(III)-mediated generation of an allyl radical species which intercepts a titanium(III)-coordinated carbonyl.
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Universal Newsreel about the independence of Ghana A postage stamp of Gold Coast overprinted for Ghanaian independence in 1957. In 1945 a Conference (known as the 5th Pan-African Congress) was held in Manchester to promote Pan-African ideas. This was attended by Nkrumah of Ghana, Nnamdi Azikiwe of Nigeria and I. T. A. Wallace-Johnson of Sierra Leone. The Indian and Pakistani independence catalysed this desire.
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Celebrations in Nanjing Road, Shanghai during the Xinhai Revolution, 1911 The Xinhai Revolution () of 1911 was catalysed by the triumph of the Wuchang Uprising, when the victorious Wuchang revolutionaries telegraphed the other provinces asking them to declare their independence, and 15 provinces in Southern China and Central China did so.Liu, Haiming. [2005] (2005). The Transnational History of a Chinese Family: Immigrant Letters, Family Business and Reverse Migration.
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In enzymology, a pyruvate synthase () is an enzyme that catalyzes the interconversion of pyruvate and acetyl-CoA. It is also called pyruvate:ferredoxin oxidoreductase (PFOR). The relevant equilibrium catalysed by PFOR is: :pyruvate + CoA + oxidized ferredoxin \rightleftharpoons acetyl- CoA + CO2 \+ reduced ferredoxin The 3 substrates of this enzyme are pyruvate, CoA, and oxidized ferredoxin, whereas its 3 products are acetyl-CoA, CO2, and reduced ferredoxin.
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All steps of glycolysis take place in the cytosol and so does the reaction catalysed by GAPDH. In red blood cells, GAPDH and several other glycolytic enzymes assemble in complexes on the inside of the cell membrane. The process appears to be regulated by phosphorylation and oxygenation. Bringing several glycolytic enzymes close to each other is expected to greatly increase the overall speed of glucose breakdown.
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The parent metallacyclopentane has the formula LnM(CH2)4. Such compounds are intermediates in the metal catalysed dimerization, trimerization, and tetramerization of ethylene to give 1-butene, 1-hexene, and 1-octene, respectively. Metallacyclopentanes are invoked as intermediates in the evolution of heterogeneous alkene metathesis catalysts from ethylene and metal oxides. Metallacyclopentane intermediates are proposed to isomerize to metallacyclobutanes, which then eliminate propylene giving the alkylidene.
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Glowing dinoflagellate bloom Marine dinoflagellates at night can emit blue light by bioluminescence, a process also called “the phosphorescence of the seas”. Light production in these single celled organisms is produced by small structures in the cytoplasm called scintillons. Among bioluminescent organisms, only dinoflagellates have scintillons. In the dinoflagellates, the biochemical reaction that produces light involves a luciferase-catalysed oxidation of a linear tetrapyrrole called luciferin.
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Lactoperoxidase-catalysed reactions yield short-lived intermediary oxidation products of SCN−, providing antibacterial activity. The major intermediary oxidation product is hypothiocyanite OSCN−, which is produced in an amount of about 1 mole per mole of hydrogen peroxide. At the pH optimum of 5.3, the OSCN− is in equilibrium with HOSCN. The uncharged HOSCN is considered to be the greater bactericidal of the two forms.
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CGC derived polymers are currently marketed by The Dow Chemical Company as part of their INSITE technology.Chum, P. S., W. J. Kruper, and M. J. Guest "Materials properties derived from INSITE metallocene catalysts." Advanced Materials 12.23 (2000): 1759-1767. Beyond the use of CGCs for polymerisation reactions, a number of other transformations catalysed by CGCs (both of Group 3 and 4 metals) have been reported from academic laboratories.
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K3PO4 Tripotassium phosphate has few industrial applications except as a reagent in organic synthesis, where it has been used as a catalyst. Some of the reactions catalysed by K3PO4are listed below: # The hydrate (K3PO4\cdot H2O) has been used to catalyze deprotection of BOC amines. Microwave radiation is used to aid the reaction. # As a catalyst for the synthesis of unsymmetrical diaryl ethers using [Bmim]BF4 as the solvent.
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RNA-processing reactions and protein synthesis on ribosomes in particular are catalysed by RNA. RNA enzymes are known as ribozymes and have provided a new tool for gene technology. They also have the potential to provide new therapeutic agents – for example, they have the ability to destroy and cleave invading, viral RNAs. Cech's second area of research is on telomeres, the structure that protects the ends of chromosomes.
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Christoffer Wilhelm Eckersberg, Woman in Front of a Mirror, 1841. French Neo- Classicism transmuted into Biedermeier style. The Danish Golden Age () covers a period of exceptional creative production in Denmark, especially during the first half of the 19th century.Kulturnet Danmark, Guide to the Danish Golden Age Although Copenhagen had suffered from fires, bombardment and national bankruptcy, the arts took on a new period of creativity catalysed by Romanticism from Germany.
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2004 48: 1307-1312 They compete with ATP for binding to the B subunit of this enzyme and inhibit the ATP-dependent DNA supercoiling catalysed by gyrase. X-ray crystallography studies have confirmed binding at the ATP-binding site located on the gyrB subunit of DNA gyrase. Their affinity for gyrase is considerably higher than that of modern fluoroquinolones, which also target DNA gyrase but at the gyrA subunit.
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Finally GSSG is reduced by glutathione reductase (GR) using NADPH as the electron donor. Thus ascorbate and glutathione are not consumed; the net electron flow is from NADPH to H2O2. The reduction of dehydroascorbate may be non-enzymatic or catalysed by proteins with dehydroascorbate reductase activity, such as glutathione S-transferase omega 1 or glutaredoxins. In plants, the glutathione-ascorbate cycle operates in the cytosol, mitochondria, plastids and peroxisomes.
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The sophistication of the active site network causes residues involved in catalysis (and residues in contact with these) to be highly evolutionarily conserved. However, there are examples of divergent evolution in catalytic triads, both in the reaction catalysed, and the residues used in catalysis. The triad remains the core of the active site, but it is evolutionarily adapted to serve different functions. Some proteins, called pseudoenzymes, have non-catalytic functions (e.g.
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As the product of polymerization is an amine with a basic character, the reaction is self-catalysed, gaining in speed with ongoing conversion. Glycolonitrile can react with ammonia to give aminoacetonitrile, which can be hydrolysed to give glycine: :HOCH2CN + NH3 → H2NCH2CN + H2O :H2NCH2CN + 2 H2O → H2NCH2CO2H + NH3 The industrially important chelating agent EDTA is prepared from glycolonitrile and ethylenediamine followed by hydrolysis of the resulting tetranitrile. Nitrilotriacetic acid is prepared similarly.
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This reaction is catalysed by a reactive center in photosystem II containing four manganese ions. The reaction begins with the excitation of a pair of chlorophyll molecules similar to those in the bacterial reaction center. Due to the presence of chlorophyll a, as opposed to bacteriochlorophyll, photosystem II absorbs light at a shorter wavelength. The pair of chlorophyll molecules at the reaction center are often referred to as P680.
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Accordingly, this reaction can be acid catalysed. This reaction occurs because unlike imidazolium based carbenes, there is no loss of aromaticity in protonation of the carbene. Unlike the dimerisation of triplet state carbenes, these singlet state carbenes do not approach head to head ("least motion"), but rather the carbene lone pair attacks the empty carbon p-orbital ("non- least motion"). Carbene dimerisation can be catalyzed by both acids and metals.
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In 1933, Marjory Stephenson and her student Stickland reported that cell suspensions catalysed the reduction of methylene blue with H2. Six years later, Hans Gaffron observed that the green photosynthetic alga Chlamydomonas reinhardtii, would sometimes produce hydrogen.Algae: Power Plant of the Future? In the late 1990s Anastasios Melis discovered that deprivation of sulfur induces the alga to switch from the production of oxygen (normal photosynthesis) to the production of hydrogen.
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1-Methylimidazole is prepared mainly by two routes industrially. The main one is acid-catalysed methylation of imidazole by methanol. The second method involves the Radziszewski reaction from glyoxal, formaldehyde, and a mixture of ammonia and methylamine. :(CHO)2 \+ CH2O + CH3NH2 \+ NH3 → H2C2N(NCH3)CH + 3 H2O The compound can be synthesized on a laboratory scale by methylation of imidazole at the pyridine-like nitrogen and subsequent deprotonation.
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Acyl-CoA Synthetase, Bubblegum Family, member 1 (ACSBG1) is an enzyme that in humans is encoded by the ACSBG1 gene. The protein encoded by this gene possesses long-chain acyl-CoA synthetase activity. It is thought to play a central role in brain very long-chain fatty acids metabolism and myelinogenesis. The conversion of long chain fatty acids into long chain acyl- CoAs in mice is catalysed by ACSBG1.
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Mizos have a practice of voluntary labour which they do to help those in distress and people in need, the British relied on forced labour and the missionaries on child labour. Later the authorities introduced labour from the 1900s onward and wage was initially paid in the form of salt and later in terms of money. Wage labour catalysed Mizoram's economy and encouraged many to join a career in the army.
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The NMR shift for 31P from H3PO4 is 15 ppm. The NMR spectrum show a triplet line at this shift. When mixed with HCl, exchange of halogen atoms between molecules is catalysed, and POCl3, POCl2F, and POF3 end up in the mixture. HCl can end up in the product due to the starting materials, or contamination by water, and must be removed if POF2F is to be stored.
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The Paris Meridian is traced on the floor. The world's first national almanac, the Connaissance des temps, was published by the Observatory in 1679, using eclipses in Jupiter's satellites to aid sea-farers in establishing longitude. In 1863, the observatory published the first modern weather maps. In 1882, a astrographic lens was constructed, an instrument that catalysed what proved to be the over-ambitious international Carte du Ciel project.
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The halogen dance rearrangement is an organic reaction in which a halogen substituent moves to a new position on an aromatic ring system. The reaction belongs to a class of organic reactions called 1,2-rearrangements. The original halogen dance is the base-catalysed rearrangement of 1,2,4-tribromobenzene to 1,3,5-tribromobenzene in liquid ammonia with the aniline/potassium base system. The intermediate in this reaction is an aryl carbanion.
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Enzyme-bound pyridoxamine in turn reacts with pyruvate, oxaloacetate, or alpha- ketoglutarate, giving alanine, aspartic acid, or glutamic acid, respectively. Many transamination reactions occur in tissues, catalysed by transaminases specific for a particular amino/keto acid pair. The reactions are readily reversible, the direction being determined by which of the reactants are in excess. This reversibility can be exploited for synthetic chemistry applications to achieve the synthesis of valuable chiral amines.
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Kinetically perfect enzymes have a specificity constant, kcat/Km, on the order of 108 to 109 M−1 s−1. The rate of the enzyme-catalysed reaction is limited by diffusion and so the enzyme 'processes' the substrate well before it encounters another molecule. Some enzymes operate with kinetics which are faster than diffusion rates, which would seem to be impossible. Several mechanisms have been invoked to explain this phenomenon.
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Methyl benzoate is formed by the condensation of methanol and benzoic acid, in presence of a strong acid.. . Page 623 Methyl benzoate reacts at both the ring and the ester, depending on the substrate. Electrophiles attack the ring, illustrated by acid-catalysed nitration with nitric acid to give methyl 3-nitrobenzoate. Nucleophiles attack the carbonyl center, illustrated by hydrolysis with addition of aqueous NaOH to give methanol and sodium benzoate.
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Sheikh Ibrahima Fall was one of the first of Amadou Bamba's disciples and one of the most illustrious.Savishinsky, J. N. (1994) The Baye Fall of Senegambia: Muslim Rastas in the Promised Land? Africa: Journal International African Institute, 64, 211-219 He catalysed the Mouride movement and led all the labour work in the Mouride brotherhood. Fall reshaped the relation between Mouride talibes (disciples) and their guide, Amadou Bamba.
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New monomer adds to the initiator and to the active growing chain in a Michael reaction. With each addition of a monomer group the trimethylsilyl group is transferred to the end of the chain. The active chain-end is not ionic as in anionic or cationic polymeriation but is covalent. The reaction can be catalysed by bifluorides and bioxyanions such as tris(dialkylamino)sulfonium bifluoride or tetrabutyl ammonium bibenzoate.
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The hydrolysis of nicotinonitrile is catalysed by the enzyme nitrile hydratase from Rhodococcus rhodochrous J1, producing 3500 tons per annum of nicotinamide for use in animal feed. The enzyme allows for a more selective synthesis as further hydrolysis of the amide to nicotinic acid is avoided. Nicotinamide can also be made from nicotinic acid. According to Ullmann's Encyclopedia of Industrial Chemistry, worldwide 31,000 tons of nicotinamide were sold in 2014.
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This enzyme participates in 4 metabolic pathways: pyruvate metabolism, propanoate metabolism, butanoate metabolism, and reductive carboxylate cycle ( fixation). Its major role is the extraction of reducing equivalents by the decarboxylation. In aerobic organisms, this conversion is catalysed by pyruvate dehydrogenase, also uses thiamine pyrophosphate (TPP) but relies on lipoate as the electron acceptor. Unlike the aerobic enzyme complex PFOR transfers reducing equivalents to flavins or iron- sulflur clusters.
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A 16S version was also produced in Europe which was equipped as above – however, the earliest models did not sport the bonnet vent. The Phase 2 models gear ratios were also revised, to allow for the extra weight found in the safety equipment the later models carried. Renault claimed an acceleration from 0 to of 8.2 seconds. Each model boasted in a catalysed form and a top speed of .
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The Rosenmund reduction is a hydrogenation process in which an acyl chloride is selectively reduced to an aldehyde. The reaction was named after Karl Wilhelm Rosenmund, who first reported it in 1918. The Rosenmund reduction The reaction, a hydrogenolysis, is catalysed by palladium on barium sulfate, which is sometimes called the Rosenmund catalyst. Barium sulfate has a low surface area which reduces the activity of the palladium, preventing over-reduction.
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1973, 95, 292–294. . The scope of this reaction has been expanded to many different carbon, nitrogen, and oxygen- based nucleophiles, many different leaving groups, many different phosphorus, nitrogen, and sulfur-based ligands, and many different metals (although palladium is still preferred).Rios, Itzel Guerrero; Rosas-Hernandez, Alonso; Martin, Erika; "Recent Advances in the Application of Chiral Phosphine Ligands in Pd-Catalysed Asymmetric Allylic Alkylation." Molecules, 2011, 16 970–1010.
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Otto Roelen (22 March 1897 – 30 January 1993) was a German chemist. Roelen was born in Mülheim, Germany and studied chemistry and graduated in 1922 from Technische Hochschule Stuttgart. He worked with Franz Fischer and Hans Tropsch at the Kaiser Wilhelm Institute for Coal Research from 1922. He developed the homogeneously catalysed hydroformylation process (also known as the "oxo synthesis") for the industrial synthesis of aldehydes from alkenes and carbon monoxide.
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Earlier intermediates have a vinyl group or 1-hydroxyethyl group in place of the acetyl group shown bacteriochlorophyll a The first step is the reduction (with trans stereochemistry) of the pyrrole ring B, giving the characteristic 18-electron aromatic system of many bacteriochlorophylls. This is carried out by the enzyme chlorophyllide a reductase, which catalyses the reaction . :chlorophyllide a + 2 reduced ferredoxin + ATP + H2O + 2 H+ \rightleftharpoons 3-deacetyl 3-vinylbacteriochlorophyllide a + 2 oxidized ferredoxin + ADP + phosphate The next two steps convert the vinyl group first into a 1-hydroxyethyl group and then into the acetyl group of bacteriochlorophyllide a. The reactions are catalysed by chlorophyllide a 31-hydratase () and bacteriochlorophyllide a dehydrogenase () as follows: :3-deacetyl 3-vinylbacteriochlorophyllide a + H2O \rightleftharpoons 3-deacetyl 3-(1-hydroxyethyl)bacteriochlorophyllide a :3-deacetyl 3-(1-hydroxyethyl)bacteriochlorophyllide a + NAD+ \rightleftharpoons bacteriochlorophyllide a + NADH + H+ These three enzyme- catalysed reactions can occur in different sequences to produce bacteriochlorophyllide a ready for esterification to the final pigments for photosynthesis.
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However, as a result of tissue-specific posttranslational processing mechanisms, different peptides are produced in the different cells. In the pancreas (α-cells of the islets of Langerhans), proglucagon is cleaved by prohormone convertase (PC) 2 producing glicentin-related pancreatic peptide (GRPP), glucagon, intervening peptide-1 (IP-1) and major proglucagon fragment (MPGF). In the gut and brain, proglucagon is catalysed by PC 1/3 giving rise to glicentin, which may be further processed to GRPP and oxyntomodulin, GLP-1, intervening peptide-2 (IP-2) and glucagon-like peptide-2 (GLP-2). Initially, GLP-1 was thought to correspond to proglucagon (72–108) suitable with the N-terminal of the MGPF, but sequencing experiments of endogenous GLP-1 revealed a structure corresponding to proglucagon (78–107) from which two discoveries were found. Firstly, the full-length GLP-1 (1–37) was found to be catalysed by endopeptidase to the biologically active GLP-1 (7–37).
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Continuous strands of fibreglass are pushed through a hand-held gun that both chops the strands and combines them with a catalysed resin such as polyester. The impregnated chopped glass is shot onto the mould surface in whatever thickness and design the human operator thinks is appropriate. This process is good for large production runs at economical cost, but produces geometric shapes with less strength than other moulding processes and has poor dimensional tolerance.
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The rise of the internet in the 20th to 21st century catalysed an increase in author profiling research, since data could be mined from the web, including social media platforms, emails and blogs. Content from the web have been analysed in tasks of author profiling to identify the age, gender, geographic origins, nationality and psychometric traits of web users. The information obtained has been used to serve various applications, including marketing and forensics.
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There are several pathways involved in lysine catabolism but the most commonly used is the saccharopine pathway, which primarily takes place in the liver (and equivalent organs) in animals, specifically within the mitochondria. This is the reverse of the previously described AAA pathway. In animals and plants, the first two steps of the saccharopine pathway are catalysed by the bifunctional enzyme, α-aminoadipic semialdehyde synthase (AASS), which possess both lysine-ketoglutarate reductase (LKR) (E.C 1.5.
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As larger amounts of substrate are added to a reaction, the available enzyme binding sites become filled to the limit of V_\max. Beyond this limit the enzyme is saturated with substrate and the reaction rate ceases to increase. The reaction catalysed by an enzyme uses exactly the same reactants and produces exactly the same products as the uncatalysed reaction. Like other catalysts, enzymes do not alter the position of equilibrium between substrates and products.
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Biosynthesis of THCA In the Cannabis plant, THC occurs mainly as tetrahydrocannabinolic acid (THCA, 2-COOH-THC, THC-COOH). Geranyl pyrophosphate and olivetolic acid react, catalysed by an enzyme to produce cannabigerolic acid, which is cyclized by the enzyme THC acid synthase to give THCA. Over time, or when heated, THCA is decarboxylated, producing THC. The pathway for THCA biosynthesis is similar to that which produces the bitter acid humulone in hops.
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The sociology of the Internet in the broad sense concerns the analysis of online communities (e.g. newsgroups, social networking sites) and virtual worlds, meaning that there is often overlap with community sociology. Online communities may be studied statistically through network analysis or interpreted qualitatively through virtual ethnography. Moreover, organizational change is catalysed through new media, thereby influencing social change at-large, perhaps forming the framework for a transformation from an industrial to an informational society.
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Tractability at lower engine speeds also improved since the smaller charger was more willing to spool up; this had been an area of concern with the earlier engine which had little power beneath 3500 rpm. In July 1988 the engine was upgraded to CB61 specifications; this version received grey rather than red casings in the engine compartment. For the Canadian (and Swiss) markets, a catalysed version of the carburetted CB60 engine was installed.
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Here, the active and inactive form of the enzymes are altered due to covalent modification of their structures which is catalysed by other enzymes. This type of regulation consists of the addition or elimination of some molecules which can be attached to the enzyme protein. The most important groups that work as modifiers are phosphate, methyl, uridine, adenine and adenosine diphosphate ribosyl. These groups are joined to or eliminated from the protein by other enzymes.
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In 1952, Zeldovich began work in the field of elementary particles and their transformations. He predicted the beta decay of a pi meson. Together with S. Gershtein he noticed the analogy between the weak and electromagnetic interactions, and in 1960, he predicted the muon catalysis (more precisely, the muon-catalysed dt-fusion) phenomenon. In 1977, Zeldovich together with Fyodor Shapiro was awarded the Kurchatov Medal, the highest award in nuclear physics of the USSR.
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The unsaturated amino acids originate from serine and threonine, and the enzyme-catalysed addition of cysteine residues to the didehydro amino acids result in the multiple (5) thioether bridges. Subtilin and epidermin are related to nisin. All are members of a class of molecules known as lantibiotics. In the food industry, nisin is obtained from the culturing of L. lactis on natural substrates, such as milk or dextrose, and it is not chemically synthesized.
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The outcome in the case of all three dynasties, says historian Richard Eaton, was that they "catalysed processes of supralocal identity formation and community building". The Kakatiya capital at Orugallu, established in 1195, was not forgotten while Ganapati expanded his territory. He organised the building of a massive granite wall around the city, complete with ramps designed for ease of access to its ramparts from within. A moat and numerous bastions were also constructed.
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Dumbo feather was launched in June 2004 by Kate Bezar, a New Zealander who had originally worked in consulting. After a trip to the newsagent, looking for inspiration, Bezar realised there was no magazine that she really identified with. This catalysed the creation of Dumbo Feather - an interview magazine profiling extraordinary people from around the world. In 2011, Small GiantsSmall Giants (a social enterprise founded by Berry Liberman and Danny Almagor) took over the magazine.
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Sodium alanateComputational Study of Pristine and Titanium-doped Sodium Alanates for ... has been explored for hydrogen storage in hydrogen tanks. The relevant reactions are: : 3 NaAlH4 → Na3AlH6\+ 2 Al + 3 H2 : Na3AlH6 → 3 NaH + Al + 3/2 H2 Sodium tetrahydroaluminate can release up to 7.4 wt % of hydrogen when heated at . Absorption can be slow, with several minutes being required to fill a tank. Both release and uptake are catalysed by titanium.
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She demonstrated that the communication of a seven year old autistic child was catalysed by using a LOGO programmed remote control device. She worked with MIT and the Technical Education Research Centers. She looked at the Brookline LOGO Project, a computer based learning system for people with disabilities, and how children used it in elementary schools. From 1985 to 1986 she held weekly meetings to look at how young people could study fractions.
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Once inside, carnitine is liberated (catalysed by the enzyme carnitine palmitoyltransferase II) and transported back outside so the process can occur again. Acylcarnitines like palmitoylcarnitine are produced as intermediate products of the carnitine shuttle. In the mitochondria, the effects of the carnitine shuttle are reduced by meldonium, which competitively inhibits the SLC22A5 transporter. This results in reduced transportation and metabolism of long-chain fatty acids in the mitochondria (this burden is shifted more to peroxisomes).
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IRA bombing Exchange Square undergoing extensive regeneration. During the 1980s, with the demise of many traditional industries under the radical economic restructuring often known as Thatcherism, the city and region experienced some decline. The revival started towards the end of the decade, catalysed, not only by wider growing prosperity in the UK but by the creative music industry. New institutions such as Factory Records and Fac 51 Hacienda earned the city the sobriquet Madchester.
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Base-catalysed phenol-formaldehyde resins are made with a formaldehyde to phenol ratio of greater than one (usually around 1.5). These resins are called resoles. Phenol, formaldehyde, water and catalyst are mixed in the desired amount, depending on the resin to be formed, and are then heated. The first part of the reaction, at around 70 °C, forms a thick reddish-brown tacky material, which is rich in hydroxymethyl and benzylic ether groups.
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A key step for the regulation of glycolysis is an early reaction in the pathway catalysed by phosphofructokinase-1 (PFK1). When ATP levels rise, ATP binds an allosteric site in PFK1 to decrease the rate of the enzyme reaction; glycolysis is inhibited and ATP production falls. This negative feedback control helps maintain a steady concentration of ATP in the cell. However, metabolic pathways are not just regulated through inhibition since enzyme activation is equally important.
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Oxidative coupling in chemistry is a coupling reaction of two molecular entities through an oxidative process. Usually oxidative couplings are catalysed by a transition metal complex like in classical cross-coupling reactions, although the underlying mechanism is different due to the oxidation process that requires an external (or internal) oxidant.Oxidative Cross‐Coupling Reactions. Aiwen Lei, Wei Shi, Chao Liu, Wei Liu, Hua Zhang, Chuan He, Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim, Germany(1997).
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Common alder, Alnus glutinosa In nitrogen-free culture and often in symbiosis, Frankia alni bacteria surround themselves in "vesicles". These are roughly spherical cellular structures that measure two to six millimetres in diameter and have a laminated lipid envelope. The vesicles serve to limit the diffusion of oxygen, thus assisting the reduction process that is catalysed by the enzyme nitrogenase. This enzyme bonds each atom of nitrogen to three hydrogen atoms, forming ammonia (NH3).
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TiCl4 finds occasional use in organic synthesis, capitalizing on its Lewis acidity, its oxophilicity, and the electron-transfer properties of its reduced titanium halides It is used in the Lewis acid catalysed aldol additionMariappan Periasamy (2002): "New synthetic methods using the TiCl4-NR3 reagent system", ARKIVOC, p. 151-166. Key to this application is the tendency of TiCl4 to activate aldehydes (RCHO) by formation of adducts such as (RCHO)TiCl4OC(H)R.
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He began a debate on the neglect of the huge psychiatric institutions. In his famous 1961 "Water Tower" speech, he said: The speech catalysed a debate that was one of several strands leading to the Care in the Community initiative of the 1980s. In 1993, however, Powell claimed that his policy could have worked. He claimed the criminally insane should have never been released and that the problem was one of funding.
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By 1939, evidence had accumulated that the model was wrong but Wrinch continued working on it. However, experimental work by Irving Langmuir done in collaboration with Wrinch to validate her ideas catalysed the principle of the Hydrophobic effect being the driving force for protein folding. In 1936 Ida Busbridge secured a position as assistant to Wrinch from whom she took over mathematics tutorials for all five women’s colleges. In 1939 Wrinch moved to the United States.
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Dirigent proteins are members of a class of proteins which dictate the stereochemistry of a compound synthesized by other enzymes. The first dirigent protein was discovered in Forsythia intermedia. This protein has been found to direct the stereoselective biosynthesis of (+)-pinoresinol from coniferyl alcohol monomers: Reaction of monolignol radicals in the presence of dirigent protein to form (+)-pinoresinol Lignan biosynthesis is catalysed by oxidative enzymes. In the test tube the reaction results in a heteregenous mixture of dimeric compounds.
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Chirality is another property that a DNAzyme can exploit. DNA occurs in nature as a right- handed double helix and in asymmetric synthesis a chiral catalyst is a valuable tool in the synthesis of chiral molecules from an achiral source. In one application an artificial DNA catalyst was prepared by attaching a copper ion to it through a spacer. The copper - DNA complex catalysed a Diels-Alder reaction in water between cyclopentadiene and an aza chalcone.
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For instance, deuterium is added to a protein in H2O by diluting the H2O solution with D2O (e.g. tenfold). Usually exchange is performed at physiological pH (7.0–8.0) where proteins are in their most native ensemble of conformational states. The H/D exchange reaction can also be catalysed, by acid, base or metal catalysts such as platinum. For the backbone amide hydrogen atoms of proteins, the minimum exchange rate occurs at approximately pH 2.6, on average.
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Addition of fucose sugars to serine and threonine residues is an unusual form of O-glycosylation that occurs in the endoplasmic reticulum and is catalysed by two fucosyltransferases. These were discovered in Plasmodium falciparum and Toxoplasma gondii. Several different enzymes catalyse the elongation of the core fucose, meaning that different sugars can be added to the initial fucose on the protein. Along with O-glucosylation, O-fucosylation is mainly found on epidermal growth factor (EGF) domains found in proteins.
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The formation of L-dopa from L-tyrosine is catalyzed by the enzyme tyrosine hydroxylase. The third stage is the formation of dopamine by removing the carboxylic acid group from L-dopa, catalysed by the enzyme dopa decarboxylase. Levodopa is also too polar to cross the blood brain barrier but it happens to be an amino acid so it has a specialized transporter called L-type amino acid transporter or LAT-1 that helps it diffuse through the barrier.
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With this in mind, Sieger informed IEC of his wish to undertake product sales and marketing in-house and disengaged from IEC after a deal was finally struck. A new company called J&S; Sieger was established towards the end of 1961. The Mark 9 marine unit, which had catalysed the emergence of what would later become one of the world's premier gas detection providers, was in fact the first in a long line of ground-breaking product innovations.
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The reaction catalysed by Cre-recombinase, for instance, may lead to excision of the DNA segment flanked by the two sites (Fig. 3A), but may also lead to integration or inversion of the orientation of the flanked DNA segment (Fig. 3B). What the outcome of the reaction will be is dictated mainly by the relative locations and orientations of the sites that are to be recombined, but also by the innate specificity of the site-specific system in question.
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Helga Ernestine Rafelski, (née Betz) (3 September 1949 - 5 November 2000) was a German particle physicist. She got her professional degree from Goethe- Universität Frankfurt am Main, her masters degree from University of Illinois at Chicago in 1977 and her PhD from University of Cape Town in 1988. She studied muon-catalysed fusion and relativistic heavy-ion collisions. Returning from South-Africa, Rafelski held a visiting position at Goethe-Universität Frankfurt am Main where she worked with Berndt Müller.
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Arguably, it could be interpreted as having transformed the entire history of Ireland. In terms of the association, the rent catalysed a transformation in a number of ways. Firstly, as previously mentioned, it gave the Catholic Association a constant source of money which enabled Daniel O'Connell to run a consistent campaign. Secondly, it facilitated easy calculation of total association membership numbers so that O'Connell could say with confidence that he had the support of so many people.
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The Kharasch addition is an organic reaction and a metal-catalysed free radical addition of CXCl3 compounds (X = Cl, Br, H) to alkenes.Name reactions: a collection of detailed reaction mechanisms, Jie Jack Li Springer; 2nd edition (September 17, 2003) 3540402039 The reaction was discovered by Morris S. Kharasch in the 1940s. The basic reaction scheme runs as follows: :R2C=CH2 \+ R'X → R2CX-CH2R': and proceeds through the CXCl2 free radical. Examples of organohalides are carbon tetrachloride and chloroform.
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Myrcenol is obtained synthetically from myrcene via hydroamination of the 1,3-diene followed by hydrolysis and Pd-catalysed removal of the amine. As a 1,3-diene, myrcenol undergoes Diels-Alder reactions with several dienophiles such as acrolein to give cyclohexene derivatives that are also useful fragrances.Karl- Georg Fahlbusch, Franz-Josef Hammerschmidt, Johannes Panten, Wilhelm Pickenhagen, Dietmar Schatkowski, Kurt Bauer, Dorothea Garbe, Horst Surburg "Flavors and Fragrances" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim.
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Amine-borane FLPs catalyse the borylation of electron-rich aromatic heterocycles (Scheme 1). The reaction is driven by release of hydrogen via C-H activation by the FLP. Aromatic borylations are often used in pharmaceutical development, particularly due to the abundance, low cost and low toxicity of boron compounds compared to noble metals., Scheme 1: Mechanism for borylation catalysed by FLPThe substrate for the reaction has two main requirements, strongly linked to the mechanism of borylation.
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This has a doubly negative effect on the lungs. Firstly, the NADPH used by pyocyanin depletes the available substrate for the reaction catalysed by the NADPH oxidase enzyme. Secondly, the superoxide radical generated can inhibit cytokines, such as IL-4, IL-13 and IFN-γ, which usually upregulate NADPH oxidase. When the lung is confronted with pyocyanin, an increased concentration of catalase and superoxide dismutase is seen in order to deal with the barrage of radicals being produced.
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Sugar phosphates are major players in metabolism due to their task of storing and transferring energy. Not only ribose 5-phosphate but also fructose 6-phosphate are an intermediate of the pentose-phosphate pathway which generates nicotinamide adenine dinucleotide phosphate (NADPH) and pentoses from glucose polymers and their degradation products. The pathway is known as glycolysis where the same carbohydrates are degraded into pyruvates thus providing energy. Enzymes are catalysed for the reactions of these pathways.
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Non-precious metal catalysts, especially those based on nickel (such as Raney nickel and Urushibara nickel) have also been developed as economical alternatives, but they are often slower or require higher temperatures. The trade-off is activity (speed of reaction) vs. cost of the catalyst and cost of the apparatus required for use of high pressures. Notice that the Raney-nickel catalysed hydrogenations require high pressures: Catalysts are usually classified into two broad classes: homogeneous catalysts and heterogeneous catalysts.
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The Guardian review found "only a few missteps in Danny Brocklehurst's otherwise impeccable script", and part of the series "too pat", with "by-numbers triumphalism", but praised "the ingenious conceit of a mystery story in which the quest for the truth is foiled by an Alzheimer's sufferer catalysed a well- plotted drama, executed without exploitativeness and, in Simm's case, played more tenderly than I'd have thought him capable."Jeffries, Stuart (4 May 2011). "TV review: Exile". The Guardian.
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The energies of the stages of a chemical reaction. Uncatalysed (dashed line), substrates need a lot of activation energy to reach a transition state, which then decays into lower-energy products. When enzyme catalysed (solid line), the enzyme binds the substrates (ES), then stabilizes the transition state (ES‡) to reduce the activation energy required to produce products (EP) which are finally released. As with all catalysts, enzymes do not alter the position of the chemical equilibrium of the reaction.
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74.6 °C) is easily evaporated as well. The reaction mechanisms involving thionyl chloride and phosphorus pentachloride are similar. Another method involves the use of oxalyl chloride: :RCO2H + ClCOCOCl → RCOCl + CO + CO2 \+ HCl The reaction is catalysed by dimethylformamide (DMF), which reacts with oxalyl chloride in the first step to give an iminium intermediate, which reacts with the carboxylic acid, abstracting an oxide, and regenerating the DMF catalyst. :500px Acid chlorides can be used as a chloride source.
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Di-tert-butyl dicarbonate is inexpensive, so it is usually purchased. Classically, this compound is prepared from tert- butanol, carbon dioxide, and phosgene, using DABCO as a base: 400px This route is currently employed commercially by manufacturers in China and India. European and Japanese companies use the reaction of sodium tert-butoxide with carbon dioxide, catalysed by p-toluenesulfonic acid or methanesulfonic acid. This process involves a distillation of the crude material yielding a very pure grade.
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The conversion of acetoin into acetyl-CoA is catalysed by the acetoin dehydrogenase complex, following a mechanism largely analogous to the pyruvate dehydrogenase complex; however, as acetoin is not a 2-oxoacid, it does not undergo decarboxylation by the E1 enzyme; instead, a molecule of acetaldehyde is released. In some bacteria, acetoin can also be reduced to 2,3-butanediol by acetoin reductase/2,3-butanediol dehydrogenase. The Voges-Proskauer test is a commonly used microbiological test for acetoin production.
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Most are mobile with flagella located in the polar regions although some species are nonmobile. The reaction catalysed by these bacteria is the first step in the oxidation of ammonia to nitrate. Nitrosomonas europaea are also important in the treatment of industrial and sewage waste in the first step of oxidizing ammonia to nitrate. Evidence suggests that ammonia-oxidizing bacteria (AOB) contribute significantly to the global production of nitrous oxide (produced by the reduction of nitrite).
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During times of increased energy demands, the phosphagen (or ATP/PCr) system rapidly resynthesizes ATP from ADP with the use of phosphocreatine (PCr) through a reversible reaction catalysed by the enzyme creatine kinase (CK). The phosphate group is attached to an NH center of the creatine. In skeletal muscle, PCr concentrations may reach 20–35 mM or more. Additionally, in most muscles, the ATP regeneration capacity of CK is very high and is therefore not a limiting factor.
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According to Maserati, the Karif could accelerate to 100 km/h (62 mph) from a standstill in 4.8 seconds, and achieve a top speed of over 255 km/h (158 mph). Other sources claim power outputs of , and for the later catalysed model. With these lower power outputs, claimed top speeds were respectively. The rear limited-slip differential was a Ranger unit manufactured by GKN, while the 5-speed manual transmission was a ZF dog-leg unit.
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In leaves of C3 plants, captured photons of solar energy undergo photosynthesis which assimilates carbon into carbohydrates (triosephosphates) in the chloroplasts of the mesophyll cells. The primary CO2 fixation step is catalysed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) which reacts with O2 leading to photorespiration that protects photosynthesis from photoinhibition but wastes 50% of potentially fixed carbon. The C4 photosynthetic pathway, however, concentrates CO2 at the site of the reaction of Rubisco, thereby reducing the biosequestration-inhibiting photorespiration.
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The rate of the base-catalysed reaction initially increases with pH, and reaches a maximum at about pH = 10. The reactive species is the phenoxide anion (C6H5O−) formed by deprotonation of phenol. The negative charge is delocalised over the aromatic ring, activating sites 2, 4 and 6, which then react with the formaldehyde. Being thermosets, hydroxymethyl phenols will crosslink on heating to around 120 °C to form methylene and methyl ether bridges through the elimination of water molecules.
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An inhibitor can reduce the effectiveness of a catalyst in a catalysed reaction (either a non-biological catalyst or an enzyme). E.g., if a compound is so similar to (one of) the reactants that it can bind to the active site of a catalyst but does not undergo a catalytic reaction then that catalyst molecule cannot perform its job because the active site is occupied. When the inhibitor is released, the catalyst is again available for reaction.
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Although Internet slang began as a means of "opposition" to mainstream language, its popularity with today's globalized digitally literate population has shifted it into a part of everyday language, where it also leaves a profound impact. Frequently used slang also have become conventionalised into memetic "unit[s] of cultural information". These memes in turn are further spread through their use on the Internet, prominently through websites. The Internet as an "information superhighway" is also catalysed through slang.
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This is in contrast to the direct sulfurylation pathways for the synthesis of cysteine or homocysteine via the replacement of the acetyl/succinyl group with free sulfide (via the cysK or cysM -encoded cysteine synthase and the metZ or metY -encoded homocysteine synthase, respectively). Two transsulfurylation pathways are known: the forward and the reverse. The forward pathway is present in several bacteria, such as Escherichia coli and Bacillus subtilis, and involves the transfer of the thiol group from cysteine to homocysteine (methionine precursor with the S-methyl group), thanks to the γ-replacement of the acetyl or succinyl group of a homoserine with cysteine via its thiol group to form cystathionine (catalysed by cystathionine γ-synthase, which is encoded by metB in E. coli and metI in B. subtilis). Cystathionine is then cleaved by means of the β-elimination of the homocysteine portion of the molecule leaving behind an unstable imino acid, which is attacked by water to form pyruvate and ammonia (catalysed by the metC-encoded cystathionine β-lyase).
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According to the hypercycle theory, the first primitive polymerase emerged precisely from this population. As a consequence, the catalysed replication could exceed the uncatalysed reactions, and the system could grow faster. However, this rapid growth was a threat to the emerging system, as the whole system could lose control over the relative amount of the RNAs with enzymatic function. The system required more reliable control of its constituents—for example, by incorporating the coupling of essential RNAs into a positive feedback loop.
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It has also been reported that an alternative variant of the AAA route has been found in Thermus thermophilus and Pyrococcus horikoshii, which could indicate that this pathway is more widely spread in prokaryotes than originally proposed. The first and rate-limiting step in the AAA pathway is the condensation reaction between acetyl-CoA and α‑ketoglutarate catalysed by homocitrate-synthase (HCS) (E.C 2.3.3.14) to give the intermediate homocitryl‑CoA, which is hydrolysed by the same enzyme to produce homocitrate.
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Similarly to O-fucosylation, O-glucosylation is an unusual O-linked modification as it occurs in the endoplasmic reticulum, catalysed by O-glucosyltransferases, and also requires a defined sequence in order to be added to the protein. O-glucose is often attached to serine residues between the first and second conserved cysteine residues of EGF domains, for example in clotting factors VII and IX. O-glucosylation also appears to be necessary for the proper folding of EGF domains in the Notch protein.
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Reuterin is a potent antimicrobial compound produced by Lactobacillus reuteri. It is an intermediate in the metabolism of glycerol to 1,3-propanediol catalysed by the coenzyme B12-dependent diol dehydrase. Reuterin inhibits the growth of some harmful Gram-negative and Gram-positive bacteria, along with yeasts, molds, and protozoa. L. reuteri can secrete sufficient amounts of reuterin to inhibit the growth of harmful gut organisms, without killing beneficial gut bacteria, allowing L. reuteri to remove gut invaders while keeping normal gut flora intact.
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Before work on ASM1 started in 1983, there was already some 15 years of experience in activated sludge modelling, although every research group that worked on mathematical systems of activated sludge created its own model framework, incompatible to all others. ASM1 therefore catalysed the research and had a major impact on activated sludge modelling . ASM1 was the foundation for numerous extensions. These extensions include for example better prediction of nitrogen and phosphorus removal. Widely used extended models include ASM2, ASM2d, and ASM3P.
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When the carbene is stabilized by a metal the selectivity increases. The compound dirhodium tetraacetate is found to be especially effective. In a typical reaction ethyl diazoacetate (a well-known carbene precursor) and dirhodium tetraacetate react with hexane; the insertion into a C−H bond occurs 1% on one of the methyl groups, 63% on the alpha-methylene unit and 33% on the beta- methylene unit. The first such reaction was reported in 1981 by Teyssié Transition-metal-catalysed reactions of diazoesters.
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Synthesised cyclic and acyclic diaminocarbenes Unlike the aromatic imidazol-2-ylidenes or triazol-5-ylidenes, these carbenes appear not to be thermodynamically stable, as shown by the dimerisation of some unhindered cyclic and acyclic examples. Studies suggest that these carbenes dimerise via acid catalysed dimerisation (as in the Wanzlick equilibrium). Diaminocarbenes have diagnostic 13C NMR chemical shift values between 230–270 ppm for the carbenic atom. The X-ray structure of dihydroimidazole-2-ylidene shows a N-C-N bond angle of ca.
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These reactions are typically catalysed by enzymes with "histone acetyltransferase" (HAT) or "histone deacetylase" (HDAC) activity. Acetylation is the process where an acetyl functional group is transferred from one molecule (in this case, acetyl coenzyme A) to another. Deacetylation is simply the reverse reaction where an acetyl group is removed from a molecule. Acetylated histones, octameric proteins that organize chromatin into nucleosomes basic structural unit of the chromosomes and ultimately higher order structures, represent a type of epigenetic marker within chromatin.
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He shared half of the Nobel Prize in Chemistry in 2001 with Ryōji Noyori for "their work on chirally catalysed hydrogenation reactions". The other half of the prize was awarded to K. Barry Sharpless for the development of a range of catalytic asymmetric oxidations. Knowles developed one of the first asymmetric hydrogenation catalysts by replacing the achiral triphenylphosphine ligands in Wilkinson's catalyst with chiral phosphine ligands. This experimental catalyst was effective for enantioselective synthesis, achieving a modest 15% enantiomeric excess.
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In this method, the glycosyl donor is protected at the C-2 position by an OAc group. The C-2-OAc protecting group is transformed into an enol ether by the Tebbe reagent (Cp2Ti=CH2), and then the glycosyl acceptor is tethered to the enol ether under acid-catalysed conditions to generate a mixed acetal. In a subsequent step, the β-mannoside is formed upon activation of the anomeric leaving group (Y), followed by work up.Barresi, F.; Hindsgaul, O. J. Am. Chem. Soc.
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Akt is partially activated by phosphorylation of T308 by PDK1. Full activation requires phosphorylation of S473, which can be catalysed by multiple proteins, including phosphoinositide-dependent kinase 2 (PDK2), integrin-linked kinase (ILK), mechanistic target of rapamycin complex (mTORC) and DNA-dependent protein kinase (DNA-PK). The regulation of Ser473 phosphorylation is not fully understood but may also be influenced by autophosphorylation after Thr308 phosphorylation. After stimulation, the levels of PIP3 decrease and Akt activity is attenuated by dephosphorylation by serine/threonine phosphatases.
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The enzyme functions by attacking, hydrolyzing, and breaking glycosidic bonds in peptidoglycans. The enzyme can also break glycosidic bonds in chitin, although not as effectively as true chitinases. Overview of the reaction catalysed by lysozymeLysozymes active site binds the peptidoglycan molecule in the prominent cleft between its two domains. It attacks peptidoglycans (found in the cell walls of bacteria, especially Gram-positive bacteria), its natural substrate, between N-acetylmuramic acid (NAM) and the fourth carbon atom of N-acetylglucosamine (NAG).
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The bilin chromophores are formed by the oxidative cleavage of a haem ring and catalysed by haem oxygenases at one of four methine bridges, allowing four possible bilin isomers to occur. In all organisms known to have biliproteins, cleavage usually occurs at the α-bridge, generating biliverdin IXα. Phycobiliproteins are grouped together in separate clusters, approximately 40nm in diameter, known as phycobilisomes. The structural changes involved in deriving bilins from their biliverdin IXα isomer determine the spectral range of light absorption.
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Other unsaturated functional groups—alkynes, imines, ketones, and aldehydes. An example is the hydrosilation of phenylacetylene:Effect of the synthetic method of Pt/MgO in the hydrosilylation of phenylacetylene Eulalia Ramírez-Oliva, Alejandro Hernández, J. Merced Martínez-Rosales, Alfredo Aguilar-Elguezabal, Gabriel Herrera-Pérez, and Jorge Cervantesa Arkivoc 2006 (v) 126-136 Link Idealized mechanism for metal-catalysed hydrosilylation of an alkene Hydrosilylation requires metal catalysts, especially those based on platinum group metals. In the related silylmetalation, a metal replaces the hydrogen atom.
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The primary emerging application of applied CeO2 materials is in the field of catalysis. Surfaces of ceria, in its most stable fluorite phase, are dominated by the lower energy (111) planes, which tend to exhibit lower surface energy. The reaction most commonly catalysed by cerium(IV) is the water gas shift reaction, involving the oxidation of carbon monoxide. Ceria has been explored towards the catalysis of various hydrocarbon conversion reactions including CO2 methanation and the catalytic oxidation of hydrocarbons such as toluene.
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At Johns Hopkins, he received the Jay Slotkin Award for excellence in research. From 1992 to 1994, he was a clinical fellow in Neurorehabilitation funded by a NIH training award and a research fellow in the Department of Neuroscience at Johns Hopkins, where he developed novel data related to programmed cell death and disease with Jay Baraban and Tim Murphy. These studies catalysed his career interest in dysregulated cell deaths and their roles in neurological disease, particularly recovery from neurological injury.
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Construction of the former Leeds Tramway along Roundhay Road in Harehills, Leeds. Bridge End in Leeds city centre, 1869. The industrial revolution had resulted in the radical growth of Leeds whose population had risen to over 150,000 by 1840. The city's industrial growth was catalysed by the introduction of the Aire & Calder Navigation in 1699, Leeds and Liverpool Canal in 1816 and the railways from 1834 onwards; the first being the Leeds and Selby Railway opened on 22 September 1834.
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Many nitrogen oxoacids are known, though most of them are unstable as pure compounds and are known only as aqueous solution or as salts. Hyponitrous acid (H2N2O2) is a weak diprotic acid with the structure HON=NOH (pKa1 6.9, pKa2 11.6). Acidic solutions are quite stable but above pH 4 base-catalysed decomposition occurs via [HONNO]− to nitrous oxide and the hydroxide anion. Hyponitrites (involving the anion) are stable to reducing agents and more commonly act as reducing agents themselves.
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In contrast to titanocene itself, titanocene dichloride and to some extent titanocene monochloride have rich and well defined chemistries. Tebbe's reagent, prepared from titanocene dichloride and trimethylaluminium, is used as a methylenation agent (conversion of R2C=O to R2C=CH2). center Tebbe's reagent adds simple alkenes to give titanocyclobutanes, which can be regarded as stable olefin metathesis intermediates. These compounds are reagents in itself such as 1,1-bis(cyclopentadienyl)-3,3-dimethyltitanocyclobutane, the adduct of Tebbe's reagent with isobutene catalysed with 4-dimethylaminopyridine.
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In response to infection, the human immune system generates minute quantities of hypochlorite within special white blood cells, called neutrophil granulocytes. These granulocytes engulf viruses and bacteria in an intracellular vacuole called the phagosome, where they are digested. Part of the digestion mechanism involves an enzyme- mediated respiratory burst, which produces reactive oxygen-derived compounds, including superoxide (which is produced by NADPH oxidase). Superoxide decays to oxygen and hydrogen peroxide, which is used in a myeloperoxidase-catalysed reaction to convert chloride to hypochlorite.
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Simple protodeboronation scheme Protodeboronation, or protodeborylation is a chemical reaction involving the protonolysis of a boronic acid (or other organoborane compound) in which a carbon-boron bond is broken and replaced with a carbon-hydrogen bond. Protodeboronation is a well-known undesired side reaction, and frequently associated with metal-catalysed coupling reactions that utilise boronic acids (see Suzuki reaction).Boronic Acids: Preparation and Applications in Organic Synthesis, Medicine and Materials, 2nd ed.; Hall, D., Ed; Wiley VCH: Weinheim, Germany, 2011; Vols.
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Early examples of metallacyclopentanes come from studies of the Ni-catalyzed linear- and cyclo-dimerization of ethylenes. Linear dimerization proceeds via beta-hydride elimination of the nickelacyclopentane (Ph3P)Ni(CH2)4 whereas cyclodimerization to give cyclobutane proceeds by reductive elimination from the related (Ph3P)2Ni(CH2)4. Another example of a metallacyclopentane is the titanocene derivative Cp2Ti(CH2)4. Metallacyclopentanes are intermediates in the metal-catalysed dimerization, trimerization, and tetramerization of ethylene to give 1-butene, 1-hexene, and 1-octene, respectively.
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Furoin synthesis from furfural is also catalyzed by vitamin B1 (thiamine). In 1957, R. Breslow proposed that this reaction involves a relatively stable carbene form of thiamine. In the catalytic cycle shown below two molecules of furfural react to give furoin, via a thiazol-2-ylidene catalyst, resulting from loss of one proton at carbon 2 of the thiazolium cation of vitamin B1: Furoin formation from furfural, catalysed by thiamine This was the first evidence for the existence of persistent carbenes.
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The main route to cyclooctane derivatives involves the dimerization of butadiene, catalysed by nickel(0) complexes such as nickel bis(cyclooctadiene). This process affords, among other products, 1,5-cyclooctadiene (COD), which can be hydrogenated. COD is widely used for the preparation of precatalysts for homogeneous catalysis. The activation of these catalysts under H2, produces cyclooctane, which is usually discarded or burnt: :C8H12 \+ 2 H2 → C8H16 Cyclooctane participates in no reactions except those typical of other saturated hydrocarbons, combustion and free radical halogenation.
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PSF coordinated the Bharat Gyan Vigyan Jatha (BGVJ) in 1987 in South India which was catalysed and supported by the Department of Science and Technology of the Government of India and also the Bharat Jan Gyan Vigyan Jatha in 1990. It is also member of the All India Peoples Science Network and the NCSTC-Network. The forum spearheaded the Arivoli Iyakkam (Total Literacy Campaign) in Puducherry along with the Education Department. Puducherry was the first state or union territory to become literate.
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Prior to assembling the super-helix, each monomer is subjected to a number of post-translational modifications that occur while the monomer is being translated. First, on the order of 145 prolyl residues of the 239 in the triple-helical domain are hydroxylated to 4-hydroxyproline by prolyl-4-hydroxylase. Second, some of the lysine residues are hydroxylated or glycosylated, and some lysine as well as hydroxylysine residues undergo oxidative deamination catalysed by lysyl oxidase. Other post- translational modifications occur after the triple helix is formed.
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The DAP pathway is regulated at multiple levels, including upstream at the enzymes involved in aspartate processing as well as at the initial DHDPS catalysed condensation step. Lysine imparts a strong negative feedback loop on these enzymes and, subsequently, regulates the entire pathway. The AAA pathway involves the condensation of α-ketoglutarate and acetyl-CoA via the intermediate AAA for the synthesis of L-lysine. This pathway has been shown to be present in several yeast species, as well as protists and higher fungi.
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Deamidation is the reaction by which a glutamate residue is formed by cleavage of the epsilon-amino group of a glutamine side chain. Transamidation, which occurs three times more often than deamidation, is the cross-linking of a glutamine residue from the gliadin peptide to a lysine residue of tTg in a reaction that is catalysed by the transglutaminase. Crosslinking may occur either within or outside the active site of the enzyme. The latter case yields a permanently covalently linked complex between the gliadin and the tTg.
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PLP is employed as it binds to amino groups and stabilises carbanion intermediates. PLP enzymes exist in their resting state as a Schiff base, the aldehyde group of PLP forming a linkage with the epsilon-amino group of an active site lysine residue on the enzyme. The alpha-amino group of the substrate displaces the lysine epsilon-amino group, in the process forming a new aldimine with the substrate. This aldimine is the common central intermediate for all PLP-catalysed reactions, enzymatic and non-enzymatic.
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Illustrative is the base-catalysed hydrolysis of esters, where the produced carboxylic acid immediately reacts with the base catalyst and thus the reaction equilibrium is shifted towards hydrolysis.) The catalyst stabilizes the transition state more than it stabilizes the starting material. It decreases the kinetic barrier by decreasing the difference in energy between starting material and transition state. It does not change the energy difference between starting materials and products (thermodynamic barrier), or the available energy (this is provided by the environment as heat or light).
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Substitution proceeds via a dissociative mechanism: :M(CO)n → M(CO)n−1 \+ CO :M(CO)n−1 \+ L → M(CO)n−1L The dissociation energy is for nickel tetracarbonyl and for chromium hexacarbonyl. Substitution in 17-electron complexes, which are rare, proceeds via associative mechanisms with a 19-electron intermediates. :M(CO)n \+ L → M(CO)nL :M(CO)nL → M(CO)n−1L + CO The rate of substitution in 18-electron complexes is sometimes catalysed by catalytic amounts of oxidants, via electron transfer.
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These government investigations of journalists catalysed debate about the role of government in censoring or prosecuting expressions they deemed potentially hateful. Critics said the cartoon controversy was a sign that attempts at judicial codification of such concepts as respect, tolerance and offence have backfired on the West. Michael Neumann wrote: > Western piety has left the West without a leg to stand on in this dispute. > It is no good trumpeting rights of free expression, because these rights are > now supposed to have nebulous but severe limitations.
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The last change in his academic career was to the University of Marburg. The war devastated the Institute and Meerwein was planning the rebuilding which was finished in 1953, the year he retired from lecturing. He conducted experimental work with the help of two postdocs until his death in 1965. His greatest impact upon organic chemistry was to propose the carbocation 2 as a reactive intermediate, originally as a rationalization of the racemization of isobornyl chloride 1 catalysed by a Lewis acid such as SnCl4.
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After World War II the Air Ministry issued specifications for a wide variety of rocket engines, both liquid and solid-fuelled. Napier responded with the design of a liquid-fuelled rocket which used catalysed Hydrogen Peroxide (H2O2), in the form of High Test Peroxide (HTP) as oxidiser and Kerosene as fuel. The Scorpion was a regeneratively-cooled HTP (High Test Peroxide)/ Kerosene bi-propellant rocket engine. Fuel and oxidiser were pumped by a single shaft turbo-pump driven by super-heated steam, generated by catalysing HTP.
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These two subunits are similar to the L and M subunits present in the bacterial reaction center. Photosystem II differs from the bacterial reaction center in that it has many additional subunits that bind additional chlorophylls to increase efficiency. The overall reaction catalysed by photosystem II is: :2Q + 2H2O + hν -> O2 \+ 2QH2 Q represents plastoquinone, the oxidized form of Q. QH2 represents plastoquinol, the reduced form of Q. This process of reducing quinone is comparable to that which takes place in the bacterial reaction center.
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Oxaloacetate forms in several ways in nature. A principal route is upon oxidation of L-malate, catalyzed by malate dehydrogenase, in the citric acid cycle. Malate is also oxidized by succinate dehydrogenase in a slow reaction with the initial product being enol-oxaloacetate. It also arises from the condensation of pyruvate with carbonic acid, driven by the hydrolysis of ATP: :CH3C(O)CO2− \+ HCO3− \+ ATP → −O2CCH2C(O)CO2− \+ ADP + Pi Occurring in the mesophyll of plants, this process proceeds via phosphoenolpyruvate, catalysed by phosphoenolpyruvate carboxylase.
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Dr Edwin Chadwick, with his publication "Treatise on Fever" (1830), catalysed the reforms of the British health system, but these did not promptly affect the Australian administrations. In the colony, proper hygienic practices -including waste management-, only started in the late years of the 19th century. This shift was partly due to the change in the administration nature of the colonies, which prior to that moment had limited the participation of the public in their affairs. Eventually, a more democratic and representative system was put into effect.
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Sharpless was a recipient of the 2001 Nobel Prize in Chemistry for his work on "chirally catalysed oxidation reactions". In 2019, Sharpless was awarded the Priestley medal, the American Chemical Society's highest honor, for “the invention of catalytic, asymmetric oxidation methods, the concept of click chemistry and development of the copper-catalyzed version of the azide-acetylene cycloaddition reaction.”. He holds honorary degrees from the KTH Royal Institute of Technology (1995), Technical University of Munich (1995), Catholic University of Louvain (1996) and Wesleyan University (1999).
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The enolase superfamily is a superfamily of enzymes, members of which catalyse a range of reactions. The enolase superfamily includes enzymes that catalyse a wide variety of reactions and performing diverse roles in metabolism. However, the reactions catalysed share the common chemical step of abstraction of a proton from a carbon adjacent to a carboxylic acid and a requirement of a divalent metal ion. This diversity of functions is in contrast to many families of enzymes whose members catalyse similar chemical reactions on different substrates.
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Ionone can be synthesised from citral and acetone with calcium oxide as a basic heterogeneous catalyst and serves as an example of an aldol condensation followed by a rearrangement reaction. The nucleophilic addition of the carbanion 3 of acetone 1 to the carbonyl group on citral 4 is base catalysed. The aldol condensation product 5 eliminates water through the enolate ion 6 to form pseudoionone 7. Image:ionone3.svg The reaction proceeds by acid catalysis where the double bond in 7 opens to form the carbocation 8.
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Whilst acknowledging the mixed origins of the Chernyakiv culture, Peter Heather suggests that the culture is ultimately a reflection of the Goths' domination of the Pontic area. He cites literary sources that attest that the Goths were the centre of political attention at this time. In particular, the culture's development corresponds well with Jordanes' tale of Gothic migration from Gothiscandza to Oium, under the leadership of Filimer. Moreover, he highlights that crucial external influences that catalysed Chernyakhov cultural development derived from the Wielbark culture.
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Acetaldehyde is an intermediate product of yeast fermentation; however, it is more commonly associated with ethanol oxidation catalysed by the enzyme ethanol dehydrogenase. Acetaldehyde production is also associated with the presence of surface film forming yeasts and bacteria, such as acetic acid bacteria, which form the compound by the decarboxylation of pyruvate. The sensory threshold for acetaldehyde is 100-125 mg/L. Beyond this level it imparts a sherry type character to the wine which can also be described as green apple, sour and metallic.
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The molecular basis of action of novobiocin, and other related drugs clorobiocin and coumermycin A1 has been examined. Aminocoumarins are very potent inhibitors of bacterial DNA gyrase and work by targeting the GyrB subunit of the enzyme involved in energy transduction. Novobiocin as well as the other aminocoumarin antibiotics act as competitive inhibitors of the ATPase reaction catalysed by GyrB. The potency of novobiocin is considerably higher than that of the fluoroquinolones that also target DNA gyrase, but at a different site on the enzyme.
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Virtually every rebel read (or listened to a reading of) his powerful pamphlet Common Sense, proportionally the all-time best-selling American title, which catalysed the rebellious demand for independence from Great Britain. Common Sense was so influential that John Adams said: "Without the pen of the author of Common Sense, the sword of Washington would have been raised in vain". The American Crisis was a pro-revolutionary pamphlet series. Paine lived in France for most of the 1790s, becoming deeply involved in the French Revolution.
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During their research, Eigen and Schuster also considered types of protein and nucleotide coupling other than hypercycles. One such alternative was a model with one replicase that performed polymerase functionality and that was a translational product of one of the RNA matrices existing among the quasispecies. This RNA-dependent RNA polymerase catalysed the replication of sequences that had specific motifs recognized by this replicase. The other RNA matrices, or just one of their strands, provided translational products which had specific anticodons and were responsible for unique assignment and transportation of amino acids.
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1) Synthesis of fumarate Fumarate is an intermediate of TCA cycle and enters the mitochondria by converting into malate and utilising the malate shuttle where it is converted into Oxaloacetic acid (OAA). OAA either enters into TCA cycle or converts into aspartate in the mitochondria. Aspartate can re-enter purine nucleotide cycle. Oxaloacetic acid + Glutamate ↔ α-Ketoglutarate + Aspartate ( Catalysed by Aspartate Aminotransferase) 2) Synthesis of ammonia (Ammonia genesis) The glutamate produced by OAA as above gains an NH3 to become a Glutamine and enters the circulation to reach kidneys.
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A few months later, in March 1990, a range of Y10 catalysed models was announced. For each existing version there was a corresponding model with a catalytic converter, with the exception of Fire carburetor, which remained the top preference of the public, for its economy. The 1,100cc engine, was called "Europa" in accordance with EU Directives, in an ecological version reached a maximum power of 50 hp (37 kW), sufficient to allow the LX to reach , the Selectronic to reach and i 4WD to reach . The catalyzed version of the GT i.e.
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However, subsequent research indicated that the enzyme was involved in the oxidative deamination of additional monoamine neurotransmitters, including Catecholamines and histamine, as shown in the figure. The enzyme was eventually renamed as monoamine oxidase, indicating that the enzyme catalysed the oxidative deamination of the class of monoamines. After the discovery of monoamine oxidase (MAO), numerous studies were conducted to determine the biological importance of monoamines. Due to the significance of MAO in the inactivation of monoamine neurotransmitters, MAO dysfunction is believed to cause several psychiatric and neurological disorders, including depression and schizophrenia.
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It is conceivable that such effects could extend to the creation of flat areas likely to be exposed to air, dry, and turn to wind-borne dust, which could fall randomly in other streams. Thus—by simple, inorganic, physical processes—a selection environment might exist for the reproduction of clay crystals of the "stickier" shape. There follows a process of natural selection for clay crystals that trap certain forms of molecules to their surfaces that may enhance their replication potential. Complex proto-organic molecules can be catalysed by the surface properties of silicates.
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The centre piece of the RSP approach is social mobilisation of the poor in order to enable them to participate directly in decisions that affect their lives and prospects. Communities are mobilised and asked to indicate their priorities through a process of dialogue, catalysed by the programmes. They are then encouraged to assume responsibility for implementing and maintaining the projects, reflecting their own priorities, with technical and financial support being extended by the programmes. The model upholds civil society as central to addressing the economic, socio- political and cultural causes of poverty.
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On 6 January 2020, university entrance exams to be taken by 300,000 students around Chile were disrupted by protests over inequality and elitism, with some students blocking access to test sites and burning exam papers. At the end of January 2020, the social unrest (which had reduced somewhat during the Chilean summer holidays) resumed again with large demonstrations. The protests were catalysed by incidents such as the death of Jorge Mora, struck by a Carabinero vehicle after a football match. As of February 2020, an estimated 36 people had died.
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In 2013, Péter Uj started a new website, 444.hu, which further catalysed the departure of journalists, including editor-in-chief Zsófi Mészáros, and all but one of the editors (the one exception being Gergely Dudás, who became Index's new editor-in-chief after Mészáros' departure). As a result, Index signed a large number of new journalists. A notable change was the arrival of Szabolcs Panyi and András Dezső, whose long-form investigative journalism was in stark contrast to Index's previous journalism that was based around being the first to react to events.
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Small student protests in support of or directly inspired by the removal of the statue and the Rhodes Must Fall movement also occurred at the University of Edinburgh and the University of California, Berkeley. Berkeley protesters felt the demands of the Rhodes Must Fall movement were relevant to their own grievances of perceived black marginalisation at Berkeley. At the University of Cambridge the movement catalysed the creation of similar 'decolonisation' student led initiatives such as the return of the okukor cockerel statue (taken during the punitive Benin Expedition of 1897) at Jesus College to Nigeria.
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Richard Gwyn was born in Pontypool, south Wales, and grew up in Crickhowell. After studying anthropology at the London School of Economics, but not completing his degree, Gwyn began to travel extensively across Europe, living for long spells in Greece and Spain, working on fishing boats and as an agricultural labourer.Abebooks interview [www.abebooks.com/docs/authors-corner/richard-gwyn.shtml] Following a period of vagrancy and serious illness, he returned to Wales, where his experiences of travel catalysed his interest in writing, and he published three collections of poetry and prose poems.
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Several assays were developed to monitor the activity of polyphenol oxidases and to evaluate the inhibition potency of polyphenol oxidase inhibitors. In particular, ultraviolet/visible (UV/Vis) spectrophotometry-based assays are widely applied. The most common UV/Vis spectrophotometry assay involves the monitoring of the formation of o-quinones, which are the products of polyphenol oxidase-catalysed reactions, or the consumption of the substrate. Alternative spectrophotometric method that involves the coupling of o-quinones with nucleophilic reagents such as 3-methyl-2-benzothiazolinonehydrazone hydrochloride (MBTH) was also used.
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This results in the production of single-stranded cDNA fragments that contain an azido-group at their 3' ends. These 3'-azido-blocked cDNA molecules are purified away from the components of the RT reaction, and subsequently 'click- ligated' to 5’ alkyne-modified DNA adaptors via copper-catalysed azide-alkyne cycloaddition (CuAAC). This generates ssDNA molecules with unnatural triazole- linked DNA backbones. Nevertheless, these templates are used in PCR reactions and amplified to generate a cDNA sequencing library with the appropriate 5' and 3' sequencing adapters and indices required for Next-Generation Sequencing.
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Most step-growth polymers can suffer hydrolysis in the presence of water, often a reaction catalysed by acid or alkali. Nylon for example, will degrade and crack rapidly if exposed to strong acids, a phenomenon well known to people who accidentally spill acid onto their tights.Failed fuel pipe at right from road traffic accident The broken fuel pipe caused a serious accident when diesel fuel poured out from a van onto the road. A following car skidded and the driver was seriously injured when she collided with an oncoming lorry.
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The majority of adiponitrile is prepared by the nickel- catalysed hydrocyanation of butadiene, as discovered at DuPont, pioneered by Drinkard. The net reaction is: : CH2=CHCH=CH2 \+ 2 HCN → NC(CH2)4CN 544x544px The process involves several stages, the first of which involves monohydrocyanation (addition of one molecule of HCN), affording isomers of pentenenitriles as well as 2- and 3-methylbutenenitriles. These unsaturated nitriles are subsequently isomerized to the 3-and 4-pentenenitriles. In the final stage, these pentenenitriles are subjected to a second hydrocyanation, in an anti-Markovnikov sense, to produce adiponitrile.
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Labour's incremental embrace of a distinctive Welsh polity was arguably catalysed in 1966 when Plaid Cymru president Gwynfor Evans won the Carmarthen by-election. In response to the emergence of Plaid Cymru and the Scottish National Party (SNP) Harold Wilson's Labour Government set up the Royal Commission on the Constitution (the Kilbrandon Commission) to investigate the UK's constitutional arrangements in 1969. The 1974–1979 Labour government proposed a Welsh Assembly in parallel to its proposals for Scotland. These were rejected by voters in the 1979 referendum: 956,330 votes against, 243,048 for.
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The halide preference, coupled to the position of the two reaction equilibria allows for a nett transhalogenation reaction to be catalysed by the enzyme. Incubation of 5'-chloro nucleosides with the enzyme, along with catalytic L-selenomethionine or L-methionine results in the production of 5-fluoro nucleosides. When [18F]fluoride is used, this transhalogenation reaction can be used for the synthesis of radiotracers for positron emission tomography. Incubation of ClDA with the fluorinase in the presence of L-methionine and fluoride ion results in the generation of FDA, through a SAM intermediate.
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Fermented tea (also known as post-fermented tea or dark tea) is a class of tea that has undergone microbial fermentation, from several months to many years. The exposure of the tea leaves to humidity and oxygen during the process also causes endo-oxidation (derived from the tea-leaf enzymes themselves) and exo- oxidation (which is microbially catalysed). The tea leaves and the liquor made from them become darker with oxidation. Thus, the various kinds of fermented teas produced across China are also referred to as dark tea, not be confused with black tea.
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Heparan-α-glucosaminide N-acetyltransferase (also called "acetyl-CoA:heparan- α-D-glucosaminide N-acetyltransferase" and "acetyl-CoA:alpha-glucosaminide N-acetyltransferase") is an enzyme that in humans is encoded by the HGSNAT gene. In enzymology, this enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. It is catalysed in the chemical reaction: :acetyl-CoA + heparan sulfate α-D-glucosaminide \rightleftharpoons CoA + heparan sulfate N-acetyl-α- D-glucosaminide This enzyme participates in glycosaminoglycan degradation and glycan structures degradation. Mutations in the gene encoding this enzyme cause mucopolysaccharidosis IIIC.
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Cyclic heme is oxidised to linear biliverdin IXα by heme oxygenase and further converted to 3Z-phycocyanobilin, the dominant phycocyanobilin isomer, by 3Z-phycocyanobilin:ferredoxin oxidoreductase. Insertion of 3Z-phycocyanobilin into the C-PC apo-protein via thioether bond formation is catalysed by phycocyanobilin lyase. The promoter for the cpc operon is located within the 427-bp upstream region of the cpcB gene. In A. platensis, 6 putative promoter sequences have been identified in the region, with four of them showing expression of green fluorescent protein when transformed into E. coli.
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During plant photosynthesis, 2 equivalents of glycerate 3-phosphate (GP; also known as 3-phosphoglycerate) are produced by the first step of the light-independent reactions when ribulose 1,5-bisphosphate (RuBP) and carbon dioxide are catalysed by the rubisco enzyme. The GP is converted to D-glyceraldehyde 3-phosphate (G3P) using the energy in ATP and the reducing power of NADPH as part of the Calvin cycle. This returns ADP, phosphate ions Pi, and NADP+ to the light-dependent reactions of photosynthesis for their continued function. RuBP is regenerated for the Calvin cycle to continue.
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A significant undesired side reaction which occurs during the baking process produces aromatic polyamines. Urethane crosslinkers based on toluene diisocyanate (TDI) can be expected to produce toluene diamine as a side reaction, whereas those based on methylene diphenyl diisocyanate produce diaminodiphenylmethane and higher order aromatic polyamines. The undesired aromatic polyamines can inhibit the cure of subsequent acid catalysed topcoat layers, and can cause delamination of the subsequent topcoat layers after exposure to sunlight. Although the industry has never acknowledged this problem, many of these undesired aromatic polyamines are known or suspected carcinogens.
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The first study reporting improvements in patients with Parkinson's disease resulting from treatment with L-dopa was published in 1968.New England Journal of Medicine [1968] 278 (11) : 630 (Cotzias, G) "L-Dopa for Parkinsonism" The 2001 Nobel Prize in Chemistry was also related to -DOPA: the Nobel Committee awarded one-quarter of the prize to William S. Knowles for his work on chirally catalysed hydrogenation reactions, the most noted example of which was used for the synthesis of -DOPA. :Synthesis of -DOPA via hydrogenation with C2-symmetric diphosphine.
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It is noteworthy that the genetic code for all organisms is basically the same, so that all living beings use the same ’genetic language’. In general, the introduction of new functional unnatural amino acids into proteins of living cells breaks the universality of the genetic language, which ideally leads to alternative life forms. Proteins are produced thanks to the translational system molecules, which decode the RNA messages into a string of amino acids. The translation of genetic information contained in messenger RNA (mRNA) into a protein is catalysed by ribosomes.
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This is due to the dysfunction of dephosphorylation mechanisms at specific amino acids on the tau protein. Tau dephosphorylation is catalysed by protein phosphatase-2A and phosphatase-2B. Deficiency or modification of one or both proteins may be involved in abnormal phosphorylation of tau in Alzheimer's disease Dephosphorylation has also been linked to cardiac disease, particularly the alteration of actin-myosin interactions that are key for providing the underlying force of a heartbeat. Dephosphorylation is a key part of the myosin cycling kinetics that directly control the actin-myosin interactions.
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Poly-CO can be produced at pressures of 5.2 GPa; it is amorphous and yellow to dark red in color. Polymerisation is catalysed by blue light at slightly lower pressures in the δ-phase of solid CO. Another white, crystalline phase can be made at higher temperatures at 6 or 7 GPa. R. J. Mills discovered this solid, which was first produced in a tungsten carbide anvil in 1947. Originally this was thought to be polymeric carbon suboxide, but the formation does not yield any gas byproduct such as carbon dioxide.
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Catalysed by the CNR national research authority, facilities have been developed in Cascina, Pontedera, Santa Croce and Peccioli. There are also a number of software development firms and IT consultancies. While in recent years the economic crisis has reduced activities in most areas, agriculture had continued to grow, thanks to traditional crops, wine production and diversification in the fruit and vegetables sector. Other sectors that have recently prospered include technology (+3.4%) and glass (+4.5%) while there have been drops in footwear (-3.1%), metals (-2%), electronics and transport equipment (-9.7%), construction (-7.8%) and manufacturing (-8.2%).
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In a non-replicating cell, a single- strand break or other type of damage in the transcribed strand of DNA can block RNA polymerase II-catalysed transcription. This would interfere with the synthesis of the protein coded for by the gene in which the blockage occurred. Brasnjevic et al. summarized the evidence showing that single-strand breaks accumulate with age in the brain (though accumulation differed in different regions of the brain) and that single-strand breaks are the most frequent steady-state DNA damages in the brain.
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Bicarbonate is an intermediate in the transport of CO2 out of the body by respiratory gas exchange. The hydration reaction of CO2 is generally very slow in the absence of a catalyst, but red blood cells contain carbonic anhydrase, which increases the reaction rate by 10,000 to 1,000,000 times, producing bicarbonate (HCO3−) dissolved in the blood plasma. This catalysed reaction is reversed in the lungs, where it converts the bicarbonate back into CO2 and allows it to be expelled. The equilibration plays an important role as a buffer in mammalian blood."excretion".
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Flagellated bacteria swim towards favourable chemicals and away from deleterious ones. Sensing of chemoeffector gradients involves chemotaxis receptors, transmembrane (TM) proteins that detect stimuli through their periplasmic domains and transduce the signals via their cytoplasmic domains . Signalling outputs from these receptors are influenced both by the binding of the chemoeffector ligand to their periplasmic domains and by methylation of specific glutamate residues on their cytoplasmic domains. Methylation is catalysed by CheR, an S-adenosylmethionine-dependent methyltransferase, which reversibly methylates specific glutamate residues within a coiled coil region, to form gamma- glutamyl methyl ester residues.
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In other cells, it is maintained in its reduced form by reaction with glutathione, which can be catalysed by protein disulfide isomerase and glutaredoxins. Ascorbic acid is a redox catalyst which can reduce, and thereby neutralize, reactive oxygen species such as hydrogen peroxide. In addition to its direct antioxidant effects, ascorbic acid is also a substrate for the redox enzyme ascorbate peroxidase, a function that is used in stress resistance in plants. Ascorbic acid is present at high levels in all parts of plants and can reach concentrations of 20 millimolar in chloroplasts.
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The Language Movement catalysed the assertion of Bengali national identity in East Bengal and later East Pakistan, and became a forerunner to Bengali nationalist movements, including the 6-Point Movement and subsequently the Bangladesh Liberation War and the Bengali Language Implementation Act, 1987. In Bangladesh, 21 February (Ekushey February) is observed as Language Movement Day, a national holiday. The Shaheed Minar monument was constructed near Dhaka Medical College in memory of the movement and its victims. In 1999, UNESCO declared 21 February as International Mother Language Day,Glassie, Henry and Mahmud, Feroz.2008.
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This is the point when the wine has the maximum amount of complexity, most pleasing mouthfeel and softening of tannins and has not yet started to decay. When this point will occur is not yet predictable and can vary from bottle to bottle. If a wine is aged for too long, it will start to descend into decrepitude where the fruit tastes hollow and weak while the wine's acidity becomes dominant. The natural esterification that takes place in wines and other alcoholic beverages during the aging process is an example of acid-catalysed esterification.
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Project Isinglass was developed as a result of the vulnerability of existing crewed reconnaissance aircraft, such as the Lockheed U-2 and the Lockheed A-12, to Soviet air defenses in the early 1960s, catalysed by the shooting down in May 1960 of Francis Gary Powers.Day 2010 Although there were continuing plans to overfly the Soviet Union with the A-12 – referred to by the CIA as Project OxcartRich 1994, p.201 – these failed to come to pass, and the CIA began plans for an aircraft with superior performance to replace Oxcart.
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In 2006 the group of E.J. Corey published a novel route bypassing shikimic acid starting from butadiene and acrylic acid. The inventors chose not to patent this procedure which is described below. Corey 2006 oseltamivir synthesis Butadiene 1 reacts in an asymmetric Diels-Alder reaction with the esterification product of acrylic acid and 2,2,2-trifluoroethanol 2 catalysed by the CBS catalyst. The ester 3 is converted into an amide in 4 by reaction with ammonia and the next step to lactam 5 is an iodolactamization with iodine initiated by trimethylsilyltriflate.
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Ms. Sundararajan was instrumental in establishing the IT department of Kerala way back in 1998. As Kerala's founding IT Secretary, she had conceived and spearheaded the Akshaya project, first started in the rural district of Malappuram, Kerala, India, and subsequently extended to the entire state. Akshaya was the largest e-literacy project of its kind where over 1 million people were trained in basic digital skills on a campaign mode. Akshaya also catalysed one of the largest known Internet Protocol (IP) based rural wireless networks in the world.
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Nancy Kwan, a Hong Kong-born American actress. Postwar Hong Kong cinema, like postwar Hong Kong industries in general, was catalysed by the continuing influx of capital and talents from Mainland China. The Hong Kong population in 1940 was around 1 million and rose to around 3.9 million in 1967, the population is increased around 2.9 million in this period. This became a flood with the 1946 resumption of the Chinese Civil War (which had been on hold during the fight against Japan) and then the 1949 Communist victory.
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The proposed biosynthesis of ginsenoside Rb1 in left The biosynthesis of GRb1 in Panax ginseng starts from farnesyl diphosphate (FPP), which is converted to squalene with squalene synthase (SQS), then to 2,3-oxidosqualene with squalene epoxidase (SE). The 2,3-oxidasqualene is then converted to dammarenediol-II by cyclization, with dammarenediol-II synthase (DS) as the catalyst. The dammarenediol-II is converted to protopanaxadiol and then to ginsenoside Rd. Finally, GRb1 is synthesized from ginsenoside Rd, catalysed by UDPG:ginsenoside Rd glucosyltransferase (UGRdGT), a biosynthetic enzyme of GRb1 first discovered in 2005.
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In enzymology, a deoxyuridine phosphorylase is an enzyme that catalyzes the chemical reaction :2'-deoxyuridine + phosphate \rightleftharpoons uracil + 2-deoxy-alpha-D-ribose 1-phosphate Thus, the two substrates of this enzyme are 2'-deoxyuridine and phosphate, whereas its two products are uracil and 2-deoxy-alpha-D-ribose 1-phosphate. No enzyme is known to be specific for this reaction, hence the EC number originally assigned to this enzyme function (EC 2.4.2.23) was deleted by the IUBMB in 2013. The reaction is catalysed by , pyrimidine-nucleoside phosphorylase, , uridine phosphorylase, and , thymidine phosphorylase.
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Published as The Ugly Spirit in Burroughs Live: The Collected Interviews of William S. Burroughs 1960-1997. 2001. Oliver Harris has questioned Burroughs' claim that Vollmer's death catalysed his writing, highlighting the importance for Queer of Burroughs' traumatic relationship with the boyfriend fictionalized in the story as Eugene Allerton, rather than the shooting of Vollmer. In any case, he had begun to write in 1945. Burroughs and Kerouac collaborated on And the Hippos Were Boiled in Their Tanks, a mystery novel loosely based on the Carr-Kammerer situation and that at the time remained unpublished.
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More importantly, the experiences of many Dutch-speaking soldiers on the front led by French-speaking officers catalysed Flemish emancipation. The French-speaking officers often gave orders in French only, followed by "et pour les Flamands, la même chose" which meant "and for the Flemish, the same thing" (which obviously did not help the Flemish conscripts who were mostly uneducated farmers and workers who didn't speak any French). The resulting suffering is still remembered by Flemish organizations during the yearly Yser pilgrimage in Diksmuide at the monument of the Yser Tower.
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Acetoxy group can be introduced into hydroxyl of 7-hydroxy-8-iodocoumarin, which is used to create vaginol or vaginidiol with an isopropyl Grignard reagent and commercially available epoxy aldehydes. Subsequent acid-catalysed fragmentation of vaginol with dichloromethane in trifluoroacetic acid yields angelicin. The compound can be isolated from natural sources, albeit this affords a low yield due to the prevalence of other furanocoumarins. The popular technique is air drying the aerial parts and ground roots of plant followed by n-hexane extraction and column chromatography over silica gel.
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Beyond this synthetic application, protodeboronation was rarely noted or valued in other chemical processes throughout the early 20th century. However, in more recent years, protodeboronation has emerged as a problematic side reaction with many chemical processes that utilise boronic acids. In particular, boronic acids have become increasingly important reagents for the facile construction of carbon-carbon and carbon-heteroatom bonds via metal-catalysed cross-coupling reactions. This has resulted in an increased usage of boronic acids, and subsequently followed by an increased number of reports concerning problematic protodeboronation.
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A current focus of the group is modification of histones, in particular oxygenase catalysed N-demethylation of histone methylated-lysine residues – in collaboration with the Structural Genomics Consortium. The histone demethylases are of interest both with respect to their links to diseases, including cancer and inflammatory diseases, as well as the role of methylation in transcriptional regulation. Recent areas of interest include the fat mass and obesity protein which was shown to be a nucleic acid demethylase and JMJD6 which is a lysyl hydroxylase modifying RNA splicing protein.
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GBP 8 worth of Zimbabwean dollars in 2003 Divisions within the opposition MDC had begun to fester early in the decade, after Morgan Tsvangirai (the president of the MDC) was lured into a government sting operation that videotaped him talking of Mr. Mugabe's removal from power. He was subsequently arrested and put on trial on treason charges. This crippled his control of party affairs and raised questions about his competence. It also catalysed a major split within the party. In 2004 he was acquitted, but not until after suffering serious abuse and mistreatment in prison.
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Another concept devised by Eigen and Schuster was a model in which each RNA template's replication was catalysed by its own translational product; at the same time, this RNA template performed a transport function for one amino acid type. Existence of more than one such RNA template could make translation possible. Nevertheless, in both alternative concepts, the system will not survive due to the internal competition among its constituents. Even if none of the constituents of such a system is selectively favoured, which potentially allows coexistence of all of the coupled molecules, they are not able to coevolve and optimize their properties.
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He was known to have screened over three thousand indigenous plant species for studying their structures and through his researches, he suggested that the secondary metabolites of microbial origin were formed during the detoxification of toxic constituent of the microorganism. He identified several active ingredients in plants and developed a new method of synthesis of internucleotide bond, using pyrimidine and purine anhydronucleosides. He discovered that the synthesis of quinomycin A could be catalysed by a cell-free extract of streptomyces. He was also a part of the CDRI investigation on parasitic protozoa causing diseases such as amoebiasis, leishmaniasis, filariasis, malaria and helminthiasis.
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These ligands were used in the hydrosilylation of ketones; achieving ee's of up to 93% The first BOX ligands were reported a year later by Masamune et al. and were first used in copper catalysed carbenoid cyclopropanation reactions; achieving ee's of up to 99% with 1% molar loadings. This was a remarkable result for the time and generated significant interest in the BOX motif. As the synthesis of 2-oxazoline rings was already well established at this time (literature reviews in 1949 and 1971), research proceeded quickly, with papers from new groups being published within a year.
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Catalysed dimerisation of acetone via an aldol condensation is well known, and yields diacetone alcohol and (by dehydration) mesityl oxide in both acidic and basic conditions. The in situ generation of mesityl oxide adds another reactive olefin to the mixture. In cases where an olefinic moiety can interact with a phenolic hydroxyl group (typically as a result of ortho-substitution), rapid cyclisation reactions producing flavans and chromans occur. This is the source of Dianin's compound in the mixture, and Dianin subsequently demonstrated that the compound can be produced in much greater yield by reacting phenol with mesityl oxide directly.
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Glutamate is a key compound in cellular metabolism. In humans, dietary proteins are broken down by digestion into amino acids, which serve as metabolic fuel for other functional roles in the body. A key process in amino acid degradation is transamination, in which the amino group of an amino acid is transferred to an α-ketoacid, typically catalysed by a transaminase. The reaction can be generalised as such: : R1-amino acid + R2-α-ketoacid ⇌ R1-α-ketoacid + R2-amino acid A very common α-keto acid is α-ketoglutarate, an intermediate in the citric acid cycle.
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Ming and Hodgetts designed the urban environment which would have catalysed the transformation of the Bridge. They envisioned a San Francisco in which the rich live in high-tech, self-sufficient, self-contained towers, above the decrepit city and its crumbling bridge, isolated from the amorphous city. The crate-packaged installation, which was surrounded by scrap metal, computer chips, and pages from manga comic strips, featured a model of the towers, along with Gibson on a monitor discussing the future and reading from "Skinner's Room". A slightly different version of the short story was featured in the November 1991 issue of Omni.
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Unlike most vinyl polymers, PVA is not prepared by polymerization of the corresponding monomer as the monomer, vinyl alcohol, is thermodynamically unstable with respect to its tautomer acetaldehyde. Instead, PVA is prepared by hydrolysis of polyvinyl acetate, or sometimes other vinyl ester-derived polymers with formate or chloroacetate groups instead of acetate. The conversion of the polyvinyl esters is usually conducted by base-catalysed transesterification with ethanol: :[CH2CH(OAc)]n \+ C2H5OH → [CH2CH(OH)]n \+ C2H5OAc The properties of the polymer are affected by the degree of transesterification. Worldwide consumption of polyvinyl alcohol was over one million metric tons in 2006.
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This is set mostly in short nervous phrases for the solo quartet, with the three lower voices singing detached notes below the soprano melody reminiscent of pizzicato strings. The sense of anxiety and foreboding continues with ominous drumbeats and wind fanfares in the Agnus Dei, which opens with minor-key timpani strokes (hence the German nickname, Paukenmesse), perhaps fate itself, knocking seemingly from the depths. This foreshadows the timpani-catalysed drama of the Agnus Dei in Beethoven's Missa Solemnis. The music brightens with trumpet fanfares, ending with an almost dance-like entreaty and celebration of peace, "Dona nobis pacem" (Give us peace).
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At the end of World War I, the political configuration of the Hungarian state was forced into swift and radical change. The Austro-Hungarian Empire, of which Hungary had been a powerful member, collapsed. The victorious Entente powers took steps to carve out Hungary's ethnically mixed border regions and grant them to the Kingdom of Serbs, Croats and Slovenes, Czechoslovakia, and Romania – efforts which resulted in Hungary's losing two thirds of its land area, and one third of its Hungarian-speaking nationals. These losses together with the postwar socioeconomic upheaval catalysed deep feelings of humiliation and resentment among many Hungarians.
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Reaction catalysed by pancreatic elastase 1. This image represents the hydrolysis of the succinyl-Ala-Ala-Ala- p-nitroanalide. The addition of one water molecule provokes the hydrolysis of the molecule and the release of p-nitroaniline. The hydrolysis that elastases bring about occur in several steps, starting with the formation of a complex between elastase and its substrate, with the carbonyl carbon positioned near the nucleophilic serine, followed by a nucleophillic attack that forms an acyl-enzyme intermediate ( a pair of electrons from the double bond of the carbonyl oxygen moves to the oxygen) while the first product is released.
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As a structural analog of glutamate and glutamine, the theanine in preparations (teas, pure supplements, etc.) is absorbed in the small intestine after oral ingestion; its hydrolysis to L-glutamate and ethylamine occur both in the intestine and liver, so theanine can be considered to function as a donor that supplies glutamate to the body. Glutamate can be metabolized to glutamine in astrocytes, a process catalysed by Glutamine synthetase and can also be decarboxylated to GABA by Glutamate decarboxylase, thus theanine can supply the neurotransmitter pools of amino acids. It can also cross the blood–brain barrier intact, and register pharmacological effects directly.
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Enzymes immobilised in beads of alginate gel An immobilized enzyme is an enzyme attached to an inert, insoluble material—such as calcium alginate (produced by reacting a mixture of sodium alginate solution and enzyme solution with calcium chloride). This can provide increased resistance to changes in conditions such as pH or temperature. It also lets enzymes be held in place throughout the reaction, following which they are easily separated from the products and may be used again - a far more efficient process and so is widely used in industry for enzyme catalysed reactions. An alternative to enzyme immobilization is whole cell immobilization.
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The natural esterification that takes place in wines and other alcoholic beverages during the aging process is an example of acid-catalysed esterification. Over time, the acidity of the acetic acid and tannins in an aging wine will catalytically protonate other organic acids (including acetic acid itself), encouraging ethanol to react as a nucleophile. As a result, ethyl acetate—the ester of ethanol and acetic acid—is the most abundant ester in wines. Other combinations of organic alcohols (such as phenol-containing compounds) and organic acids lead to a variety of different esters in wines, contributing to their different flavours, smells and tastes.
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L-tyrosine L-DOPA L-dopaquinone L-leucodopachrome L-dopachrome The first step of the biosynthetic pathway for both eumelanins and pheomelanins is catalysed by tyrosinase. :Tyrosine → DOPA → dopaquinone Dopaquinone can combine with cysteine by two pathways to benzothiazines and pheomelanins :Dopaquinone + cysteine → 5-S-cysteinyldopa → benzothiazine intermediate → pheomelanin :Dopaquinone + cysteine → 2-S-cysteinyldopa → benzothiazine intermediate → pheomelanin Also, dopaquinone can be converted to leucodopachrome and follow two more pathways to the eumelanins :Dopaquinone → leucodopachrome → dopachrome → 5,6-dihydroxyindole-2-carboxylic acid → quinone → eumelanin :Dopaquinone → leucodopachrome → dopachrome → 5,6-dihydroxyindole → quinone → eumelanin Detailed metabolic pathways can be found in the KEGG database (see External links).
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He was seconded to the Ministry of Information in the Second World War and conducted training in aircraft recognition for the Royal Observer Corps—this experience catalysed a deep interest in aviation history. He authored the government's manual on aircraft recognition in 1944 as well as being a contributor to the training journal Aircraft Recognition, then became the ministry's Director of the Photographic Division in 1945. Between 1947 and 1971 he was Keeper of the Department of Public Relations at the Victoria and Albert Museum. The department, the first public relations department of any English museum, was initially called the Museum Extension Services.
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Boronic acids can be obtained via several methods. The most common way is reaction of organometallic compounds based on lithium or magnesium (Grignards) with borate esters.Example: Example: For example, phenylboronic acid is produced from phenylmagnesium bromide and trimethyl borate followed by hydrolysis :PhMgBr + B(OMe)3 → PhB(OMe)2 \+ MeOMgBr :PhB(OMe)2 \+ H2O → PhB(OH)2 \+ MeOH Another method is reaction of an arylsilane (RSiR3) with boron tribromide (BBr3) in a transmetallation to RBBr2 followed by acidic hydrolysis. A third method is by palladium catalysed reaction of aryl halides and triflates with diboronyl esters in a coupling reaction.
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Proteolysis is typically catalysed by cellular enzymes called proteases, but may also occur by intra-molecular digestion. Low pH or high temperatures can also cause proteolysis non-enzymatically. Proteolysis in organisms serves many purposes; for example, digestive enzymes break down proteins in food to provide amino acids for the organism, while proteolytic processing of a polypeptide chain after its synthesis may be necessary for the production of an active protein. It is also important in the regulation of some physiological and cellular processes, as well as preventing the accumulation of unwanted or abnormal proteins in cells.
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About 4,000 reactions are known to be catalysed by enzymes. The rate acceleration conferred by enzymatic catalysis is often enormous—as much as 1017-fold increase in rate over the uncatalysed reaction in the case of orotate decarboxylase (78 million years without the enzyme, 18 milliseconds with the enzyme). The molecules bound and acted upon by enzymes are called substrates. Although enzymes can consist of hundreds of amino acids, it is usually only a small fraction of the residues that come in contact with the substrate, and an even smaller fraction—three to four residues on average—that are directly involved in catalysis.
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Synthese eines substituierten Butenolids mit Diethylmesoxalat With guanidines, a functionalized imidazolone is produced in 85% yield. Synthese von Imidazolonen mit Diethylmesoxalat Diethyl oxomalonate is a versatile reactant in the Baylis-Hillman reaction and forms the corresponding multifunctional compounds with acrylates, acrylonitrile, or methyl vinyl ketone catalysed by DABCO. Baylis–Hillman reaction mit Diethylmesoxalat Diethyl oxomalonate reacts with the Grignard compound formed from 1-iodo-2-chloromethylbenzene and isopropylmagnesium chloride to give 2-bis- carboxyethyl-isobenzofuran. Synthese von Isobenzofuranen mit Diethylmesoxalat Diethyl oxomalonate is added to terminal double bonds of alkenes in an ene reaction to give 1-hydroxy-1-alkylmalonic esters.
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In enzymology, precorrin-6A synthase (deacetylating) () is an enzyme that catalyzes the chemical reaction :S-adenosyl-L-methionine + precorrin-5 + H2O \rightleftharpoons S-adenosyl-L-homocysteine + precorrin-6A + acetate The conversion of precorrin-5 to precorrin-6A is catalysed by the enzyme CobF in Pseudomonas denitrificans The 3 substrates of this enzyme are S-adenosyl methionine, precorrin 5, and H2O. Its 3 products are S-adenosylhomocysteine, precorrin 6A, and acetate. This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:precorrin-5 C1-methyltransferase (deacetylating).
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CheR proteins are part of the chemotaxis signaling mechanism which methylates the chemotaxis receptor at specific glutamate residues. Methyl transfer from the ubiquitous S-adenosyl-L-methionine (AdoMet/SAM) to either nitrogen, oxygen or carbon atoms is frequently employed in diverse organisms ranging from bacteria to plants and mammals. The reaction is catalysed by methyltransferases (Mtases) and modifies DNA, RNA, proteins and small molecules, such as catechol for regulatory purposes. The various aspects of the role of DNA methylation in prokaryotic restriction-modification systems and in a number of cellular processes in eukaryotes including gene regulation and differentiation is well documented.
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A key molecule produced as a result of the oxidative PPP by PKM2 is NADPH. NADPH functions as a cofactor and provides reducing power in many enzymatic reactions that are crucial for macromolecular biosynthesis. Another mechanism by which NADPH is produced in mammalian cells is the reaction converting isocitrate to α-ketoglutarate (αKG), which is catalysed by NADP-dependent isocitrate dehydrogenase 1 (IDH1) and IDH2 and have been found linked to tumorigenesis in glioblastoma and acute myeloid leukemia. They are also found to interact with arginine residues required for isocitrate binding in the active site of the proteins of IDH1 and IDH2.
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If the law of mass action is applied to an enzyme-catalysed process it results in the Michaelis–Menten equation, from which Monod is inspired. This makes things difficult for in situ biosurfactant production because controlled experimentation is required to determine specific growth rate and Michaelis–Menten parameters of rate-limiting enzyme reaction. Modelling of bioclogging is complicated because the production of clogging metabolite is coupled nonlinearly to the growth of microbes and flux of nutrients transported in the fluid. The ecophysiology of the entire microbial microcosms at oil reservoir conditions is still unclear and thus not considered by the available models.
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After his post graduation with very good grades from IRMA, in 1982, he chose to work in a small rural development trust, Tribhuvandas Foundation, in Anand, Kheda district, over much more visible and better paying jobs with Government sponsored milk cooperative federations. In Tribhuvandas Foundation, he catalysed its growth from a small family run trust, to working in hundred odd villages, hiring professional rural medical doctors, and extension staff. After two years with Tribhuvandas foundation, he won the INLAKs foundation scholarship for a MSc degree in economics from St Anne's College, Oxford in 1984. After Oxford, he decided to return to rural India.
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Allylic C-H bonds and phenyl C-H bonds got carboxylated with this approach by Hou and co-workers: Scheme 3 Copper catalysed boracarboxylation of internal alkynes Carbometallation to alkynes and allenes using organozinc and organoaluminum reagents followed by transmetallation to copper is also a strategy to initiate carboxylation. Trimethylaluminium is able to insert into unbiased aliphatic internal alkynes with syn fashion directed by ether directing group. Vinyl copper complexes are formed by transmetallation and carboxylation is realized with a similar pathway giving tetrasubstituted aliphatic vinyl carboxylic acids. In this case, regioslectivity is controlled by the favor of six-membered aluminum ring formation.
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The CTI version offered the same plastic arches and wheels as the 1.6 GTI. Some later models incorporated the catalysed 1.9-litre engine. Peugeot 205 GTI 1.9 The main aesthetic difference between the GTI/CTi versions and other 205 models were the plastic wheel arches and trim, beefier front and rear bumper valances. The shell also underwent some minor changes, including larger wheel arches (to suit the larger wheels on the GTI and CTi), and the suspension was redesigned and sat lower on the GTI with stiffer springs, different wishbones and a drop-linked anti-roll bar.
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In 1995 in an article in The Irish Times, he proposed what would later turn into the Criminal Assets Bureau which was set up in 1996, catalysed by the death of journalist Veronica Guerin. His role in its development would be acknowledged later by the then Minister of Justice Nora Owen. He also advocated for Dublin's street traders. After attending a sit-down protest with Sinn Féin Councillor Christy Burke, and future Labour Party TD Joe Costello on Dublin's O'Connell Street in defence of a street trader; he, Burke and four others were arrested and charged with obstruction and threatening behaviour.
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Methyl acrylate is after butyl acrylate and ethyl acrylate the third most important acrylic ester with a worldwide annual production of about 200,000 tons per year.CEH Marketing Research Report Acrylic Acid and Esters, SRI Consulting, Juli 2007. Methyl acrylate reacts catalysed by Lewis bases in a Michael addition with amines in high yields to β-alanine derivatives which provide amphoteric surfactants when long-chain amines are used and the ester function is hydrolysed subsequently. Amphotere beta-alanine Methyl acrylate is used for the preparation of 2-dimethylaminoethyl acrylate by transesterification with dimethylaminoethanol in significant quantities of over 50,000 tons / year.
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MID1 is a microtubular protein that acts as an ubiquitin E3 ligase in vitro and in cells. Ubiquitination is a type of post- translational modification in which the transfer of one or several ubiquitin peptide molecules to substrates determines their stability and/or activity. The MID1 E3 ubiquitin ligase activity is catalysed by the RING domain, a hallmark of one of the main classes of E3 ubiquitin ligases that, within the ubiquitination cascade, facilitate the transfer of the ubiquitin peptide to specific substrates. Several MID1 E3 ubiquitin ligase targets have been reported: Alpha4 (α4) and its associated phosphatase, PP2A, Fu, Pax6 and BRAF35.
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The Battle of Namutoni fought between the militaries of the Ondonga kingdoms and German Southwest Africa on 28 January 1904 was part of an uprising against German Colonial expansion catalysed by the Herero Uprising to the south that started a few weeks earlier. It was fought at the site of Fort Namutoni in northern Namibia. The fort was held by four regular soldiers of the German Schutztruppe and three colonial reservists: Fritz Grossman NCO, Jakob Basendowski (NCO), Health Sergeant Bruno Lassmann and soldiers 1st Class Richard Lemke, Albert Lier, Franz Becker and Karl Hartmann. The fort was stocked with 1,500 rounds of ammunition.
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The site Hamin Mangha in northeast China dates back to approximately 5000 years ago and features a small structure filled with almost 100 bodies. This could mean the location faced an outbreak that surpassed what the village could handle. Two other sites like these have been found in Northeast China: Miaozigou and Laijia. Conditions for the population increase that preceded that decline are generally ascribed to rapid population growth between 5950 and 5550 BP. That growth was catalysed by the introduction of agriculture, along with the spread of technologies such as pottery, the wheel, and animal husbandry.
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Kinase- related protein (telokin) binds to dephosphorylated smooth myosin near the junction between the rod and the catalytic head region (S-I). This interaction is prevented by MLCK-catalysed phosphorylation of myosin and conversely, the rate of myosin phosphorylation is in turn inhibited by KRP in vitro. As a consequence of this, in vivo KRP might slow down the rate of myosin phosphorylation by myosin light chain kinase (MLCK) and, therefore, tension development. When the intracellular Ca2+ level is decreasing, the KRP can also accelerate muscle relaxation by lowering the ratio of phosphorylated to phosphorylated myosin.
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CYP1A1 is involved in phase I xenobiotic and drug metabolism (one substrate of it is theophylline). It is inhibited by hesperetin (a flavonoid found in lime, sweet orange), fluoroquinolones and macrolides and induced by aromatic hydrocarbons. CYP1A1 is also known as AHH (aryl hydrocarbon hydroxylase). It is involved in the metabolic activation of aromatic hydrocarbons (polycyclic aromatic hydrocarbons, PAH), for example, benzo[a]pyrene (BaP), by transforming it to an epoxide. In this reaction, the oxidation of benzo[a]pyrene is catalysed by CYP1A1 to form BaP-7,8-epoxide, which can be further oxidized by epoxide hydrolase (EH) to form BaP-7,8-dihydrodiol.
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Hydrogen peroxide is thermodynamically unstable and decomposes to form water and oxygen with a ΔH ~~o~~ of –2884.5 kJ/kg and a ΔS of 70.5 J/(mol·K): :2 → 2 + The rate of decomposition increases with rise in temperature, concentration, and pH, with cool, dilute, acidic solutions showing the best stability. Decomposition is catalysed by various compounds, including most transition metals and their compounds (e.g. manganese dioxide (MnO2), silver, and platinum). Certain metal ions, such as or , can cause the decomposition to take a different path, with free radicals such as the hydroxyl radical (HO·) and hydroperoxyl (HOO·) being formed.
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This catalysed the Directive 1996/48 about the interoperability of high-speed trains, followed by Directive 2001/16 extending the concept of interoperability to the conventional rail system. ETCS specifications have become part of, or are referred to, the Technical Specifications for Interoperability (TSI) for (railway) control-command systems, pieces of European legislation managed by the European Union Agency for Railways (ERA). It is a legal requirement that all new, upgraded or renewed tracks and rolling stock in the European railway system should adopt ETCS, possibly keeping legacy systems for backward compatibility. Many networks outside the EU have also adopted ETCS, generally for high-speed rail projects.
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Immigration, both from within and outside the country, is regarded as one of the main factors that have contributed to urbanisation in Pakistan. One analysis of the 1998 Pakistan Census highlighted the significance of the independence of Pakistan in 1947 in the 1940s in the context of understanding the urban change in Pakistan. During the independence period, Muslim Muhajirs from India migrated in large numbers and shifted their domicile to Pakistan, especially to the port city of Karachi, which is today the largest metropolis in Pakistan. Migration from other countries, mainly those in the neighbourhood, has further catalysed the process of urbanisation in Pakistani cities.
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Phosphinooxazolines are able to influence both the enantioselectivity and regioselectivity of a range of metal catalysed reactions. In reactions involving symmetric transition states these properties work in concert to induce asymmetry and thus promote the formation of a single product. Enantioselectivity is controlled by the chirality of the ligand which is normally located on the oxazoline ring, however the P-centre may also be stereogenic. Regioselectivity is controlled by variety of steric and electronic factors the most important of which being a form of trans effect, in which atoms complexed trans to the P‑atom become more electrophilic than ones located trans to the N‑atom.
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Gulian produced at the peak of his career several expositions of Hegelian philosophy, completely lacking any value. During these first decades, philosophy was taught in Universities by dentists or illiterate workers turned into professors virtually overnight: Following Stalin's death, hardcore communist dogma slowly lost some of its force. After 1964, the date of the great amnesty of all political prisoners, philosophical life had a chance to come back into existence, partly catalysed by the professional reinsertion of the relatively few surviving philosophers, who were either imprisoned or marginalized. Thus, we can distinguish several "schools" of philosophers: the interbellum school, the Păltiniş school and the Epistemological School of Bucharest.
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However, unlike uncatalysed chemical reactions, enzyme-catalysed reactions display saturation kinetics. For a given enzyme concentration and for relatively low substrate concentrations, the reaction rate increases linearly with substrate concentration; the enzyme molecules are largely free to catalyse the reaction, and increasing substrate concentration means an increasing rate at which the enzyme and substrate molecules encounter one another. However, at relatively high substrate concentrations, the reaction rate asymptotically approaches the theoretical maximum; the enzyme active sites are almost all occupied by substrates resulting in saturation, and the reaction rate is determined by the intrinsic turnover rate of the enzyme.Fromm H.J., Hargrove M.S. (2012) Enzyme Kinetics.
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A Christmas Carol is most probably his best-known story, with frequent new adaptations. It is also the most-filmed of Dickens's stories, with many versions dating from the early years of cinema. According to the historian Ronald Hutton, the current state of the observance of Christmas is largely the result of a mid-Victorian revival of the holiday spearheaded by A Christmas Carol. Dickens catalysed the emerging Christmas as a family-centred festival of generosity, in contrast to the dwindling community-based and church-centred observations, as new middle-class expectations arose.. Its archetypal figures (Scrooge, Tiny Tim, the Christmas ghosts) entered into Western cultural consciousness.
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If L is small as compared with Lmfp, which normally is the case for very small vias, the technological parameters to optimize are primarily the contact resistance and the tube density. Initial works have been focused on CNT vias connecting two metallic lines. Low temperature (400 °C) chemical vapor deposition growth of CNT on titanium nitride catalysed by cobalt particles has been optimized by the Fujitsu group. The catalyst particles obtained by laser ablation of a cobalt target sorted by size ultimately allow to grow a CNT density around 1012 CNT cm−2 using a multistep process using plasma and catalyst particles around 4 nm.
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The attacks by Hyder Ali in 1767 catalysed the process, which resulted in the building of a protective wall around the new Black Town, including the neighbourhoods such as Muthialpettah and Peddunaickenpettah (parts of the present-day George Town), located at the northern and western sides of the Fort. The Black Town Wall, as it was known then, was conceived by the company's chief engineer John Call and completed in 1772 by Paul Benfield, a contractor with the British government bidding about 500,000. With the Fort to the south and the sea to the east, the wall with 17 bastions ran for about 3.5 miles.
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The human FAT1 cadherin gene was cloned in 1995 from a human T-leukemia (T-ALL) cell line and consists of 27 exons located on chromosome 4q34–35. Structurally the FAT1 protein is a single pass transmembrane protein with the extracellular portion consisting of 34 cadherin repeats, 5 EGF-like domains and a laminin-G like domain. The FAT1 protein once translated undergoes furin mediated S1 cleavage forming a non-covalent heterodimer before achieving cell surface expression although this processing is often perturbed in cancer cells which express non-cleaved FAT1 on the cell surface. FAT1 cadherin is multiply phosphorylated on its ectodomain but phosphorylation is not catalysed by FJX1.
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The BODIPY core has a rich derivative chemistry due to the high tolerance for substitutions in the pyrrole and aldehyde (or acyl chloride) starting materials. Hydrogen atoms at the 2 and 6 positions of the cyclic core can be displaced by halogen atoms using succinimide reagents such as NCS, NBS and NIS - which allows for further post-functionalisation through palladium coupling reactions with boronate esters, tin reagents etc. The two fluorine atoms on the boron atom can be replaced, during or after synthesis, by other strong nucleophilic reagents, such as lithiated alkyne or aryl species, chlorine, methoxy, or a divalent "strap". The reaction is catalysed by BBr3 or SnCl4.
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The fluorinase catalyses an SN2-type nucleophilic substitution at the C-5' position of SAM, while L-methionine acts as a neutral leaving group. The fluorinase-catalysed reaction is estimated to be between 106 to 1015 times faster than the uncatalysed reaction, a significant rate enhancement. Despite this, the fluorinase is still regarded as a slow enzyme, with a turnover number (kcat) of 0.06 min−1. The high kinetic barrier to reaction is attributed to the strong solvation of fluoride ion in water, resulting in a high activation energy associated with stripping solvating water molecules from aqueous fluoride ion, converting fluoride into a potent nucleophile within the active site.
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The reaction catalysed by the fluorinase is reversible, and upon incubation of 5'-fluoro-5'-deoxyadenosine and L-methionine with the fluorinase, SAM and fluoride ion are produced. Replacing L-methionine with L-selenomethionine results in a 6-fold rate enhancement of the reverse reaction, due to the increased nucleophilicity of the selenium centre compared to the sulfur centre. The fluorinase shows a degree of substrate tolerance for halide ion, and can also use chloride ion in place of fluoride ion. While the equilibrium for reaction between SAM and fluoride ion lies towards products FDA and L-methionine, the equilibrium position is reversed in the case for chloride ion.
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The revival of interest in Irish traditional culture was closely linked to Nationalist calls for independence and was catalysed by the foundation of the Gaelic League in 1893. This sought to encourage the rediscovery and affirmation of Irish traditional arts by focusing upon the Irish language, but also established an annual competition, the Feis Cheoil, in 1903 as a focus for its activities. In the US, traditional musicians remained popular in Irish communities in large cities such as Chicago. Francis O'Neill (1848-1936) was a collector and promoter of Irish traditional music whose work was a "huge influence on the evolution of Irish traditional dance music in the twentieth century".
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However, tRNA binding involves an alpha-helical structure that is conserved between class I and class II synthetases. In reactions catalysed by the class I aminoacyl-tRNA synthetases, the aminoacyl group is coupled to the 2'-hydroxyl of the tRNA, while, in class II reactions, the 3'-hydroxyl site is preferred. The synthetases specific for arginine, cysteine, glutamic acid, glutamine, isoleucine, leucine, methionine, tyrosine, tryptophan and valine belong to class I synthetases; these synthetases are further divided into three subclasses, a, b and c, according to sequence homology. The synthetases specific for alanine, asparagine, aspartic acid, glycine, histidine, lysine, phenylalanine, proline, serine, and threonine belong to class-II synthetases.
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The new unloading sequence consists of an almost thermoneutral catalysed transfer hydrogenation step converting ketone (acetone) to secondary alcohol (2-propanol) by contacting hydrogen-rich carrier (H18-DBT), and the secondary alcohol is then directly consumed in a PEMFC (direct isopropanol fuel cell; DIPAFC).2-propanol fuel cells, HI ERN. It is a CO2 emission-free, external energy input-free, and safe sequence with no molecular hydrogen at any point during hydrogen releasing. The "direct LOHC fuel cell" based on the LOHC-DIPAFC coupling concept is a very attractive solution for the on-board generation of electric energy in mobile applications, and it's driving researchers to focus on the topic.
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More recently azide functional groups have been conjugated to the N-terminal of a dragline silk protein using EDC/NHS coupling, yielding glycopolymer-conjugated films with enhanced cell adhesion and DNA-silk chimeras with controllable micro-architectures. Armed with this, the researchers in this study investigated the incorporation of 3 L-Aha residues into 4RepCT, yielding 4RepCT^{3Aha} . The azide side chains of L-Aha allow highly specific and efficient site-specific conjugation to a lot different of functional molecules via Staudinger ligation with phosphine reagents, and Copper (I)-catalysed azide-alkyne cycloaddition (CuAAC) or Strain promoted azide-alkyne cycloaddition (SPAAC) in click reactions.
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Acidic pyrolysis of cellulose to yield levoglucosenone (LGO) Dihydrolevoglucosenone can be prepared through the hydrogenation of unsaturated anhydrosugar levoglucosenone (LGO) by using supported metal catalysts under mild conditions. Levoglucosenone is, at the same time, a chemical building block obtained by acid-catalysed pyrolysis at 300 °C of lignocellulosic biomass such as wood waste or sawdust. A significant amount of char is produced, as a by-product of LGO production, which can be used as fuel. When cellulose in tetrahydrofuran is heated to 210 °C with low concentrations of sulfuric acid in an autoclave, up to 51% levoglucosenone can be obtained through a solvent-assisted pyrolysis.
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Radio Times' Alison Graham wrote, "A tremendous piece of drama; subtle, intelligent, powerful and adult. Writer Danny Brocklehurst and creator Paul Abbott have achieved something wonderful by blending a touching human story with a riveting thriller. This is as good as TV drama can be.. On every level Exile delivers." The ingeniously plotted Exile is over - steel yourself for a Hollywood remake, The Guardian,4-May-2011, page 25; "The ingenious conceit of a mystery story in which the quest for the truth is foiled by an Alzheimer's sufferer catalysed a well-plotted drama, executed without exploitativeness and, in Simm's case, played more tenderly that I'd have thought him capable".
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In enzymology, precorrin-3B C17-methyltransferase () is an enzyme that catalyzes the chemical reaction :S-adenosyl-L-methionine + precorrin-3B \rightleftharpoons S-adenosyl-L-homocysteine + precorrin-4 The conversion of precorrin-3B to precorrin-4 is catalysed by the enzyme CobJ in Pseudomonas denitrificans The two substrates of this enzyme are S-adenosyl methionine and precorrin 3B, and its two products are S-adenosylhomocysteine and precorrin 4. This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:precorrin-3B C17-methyltransferase. Other names in common use include precorrin-3 methyltransferase, and CobJ.
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In one study, seven- membered rings were constructed in a tandem 5-exo-dig addition reaction / Claisen rearrangement:Li, X.; Kyne, R. E.; Ovaska, T. V. Synthesis of Seven- Membered Carbocyclic Rings via a Microwave-Assisted Tandem Oxyanionic 5-exo dig Cyclization−Claisen Rearrangement Process, J. Org. Chem., 2007, 72, 6624 :5-exo-dig reaction Li 2007 A 6-endo-dig pattern was observed in an allene - alkyne 1,2-addition / Nazarov cyclization tandem catalysed by a gold compound:Guan-You Lin, Chun-Yao Yang, and Rai-Shung Liu. Gold-Catalyzed Synthesis of Bicyclo[4.3.0]nonadiene Derivatives via Tandem 6-endo-dig/Nazarov Cyclization of 1,6-Allenynes J. Org. Chem.
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Glycogen synthesis is, unlike its breakdown, endergonic—it requires the input of energy. Energy for glycogen synthesis comes from uridine triphosphate (UTP), which reacts with glucose-1-phosphate, forming UDP-glucose, in a reaction catalysed by UTP—glucose-1-phosphate uridylyltransferase. Glycogen is synthesized from monomers of UDP-glucose initially by the protein glycogenin, which has two tyrosine anchors for the reducing end of glycogen, since glycogenin is a homodimer. After about eight glucose molecules have been added to a tyrosine residue, the enzyme glycogen synthase progressively lengthens the glycogen chain using UDP-glucose, adding α(1→4)-bonded glucose to the reducing end of the glycogen chain.
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Energy conversion by the inner mitochondrial membrane and chemiosmotic coupling between the chemical energy of redox reactions in the respiratory chain and the oxidative phosphorylation catalysed by the ATP synthase (sometimes called as "mitochondrial mushrooms"). The movement of ions across the membrane depends on a combination of two factors: # Diffusion force caused by a concentration gradient - all particles tend to diffuse from higher concentration to lower. # Electrostatic force caused by electrical potential gradient - cations like protons H+ tend to diffuse down the electrical potential, from the positive (P) side of the membrane to the negative (N) side. Anions diffuse spontaneously in the opposite direction.
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The reaction catalysed by Tn3 resolvase To separate the host and target molecules Tn3 resolvase executes site-specific recombination between the old and new copy of transposon at a specific site called res, which is present in each copy of the transposon. Res is 114 bp long and it consists of 3 sub-sites, namely sites I, II and III. Each of these sites is of different lengths (28, 34 and 25bp, respectively) and they are unevenly spaced with 22bp separating sites I and II and only 5bp between sites II and III. The sites consist of 6bp inverted repeat motifs flanking a central sequence of variable length.
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In eukaryotes, glutathione S-transferases (GSTs) participate in the detoxification of reactive electrophilic compounds by catalysing their conjugation to glutathione. The GST domain is also found in S-crystallins from squid, and proteins with no known GST activity, such as eukaryotic elongation factors 1-gamma and the HSP26 family of stress-related proteins, which include auxin-regulated proteins in plants and stringent starvation proteins in Escherichia coli. The major lens polypeptide of cephalopods is also a GST. Bacterial GSTs of known function often have a specific, growth-supporting role in biodegradative metabolism: epoxide ring opening and tetrachlorohydroquinone reductive dehalogenation are two examples of the reactions catalysed by these bacterial GSTs.
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I. Studies in the Pregnane Series O. R. RODIG, P. BROWN, and P. ZAFFARONI J. Org. Chem. 1961, 26(7), 2431-2435\. () Westphalen–Lettré rearrangement The reaction is first-order in steroid in the presence of an excess of sulfuric acidAcid catalysed reactions of 5α-hydroxy-steroids—III : The westphalen rearrangementTetrahedron, Volume 21, Issue 6, 1965, Pages 1567-1580 J. W. Blunt, A. Fischer, M. P. Hartshorn, F. W. Jones, Kirk D. N. and S. W. Yoong () and the first reaction step in the reaction mechanism is likely the formation of a sulfate ester followed by that of a carbocation at C5 after which the actual rearrangement takes place.
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During > the shooting of a musical film The Sound of Music, the plot of which unfolds > just the times of the Anschluss and immediately after, the Authorities of > Salzburg forbade the producers to decorate the streets of the city with Nazi > symbols insisting that "there had never been Nazis in Salzburg". They > retreated only after the producers threatened to use the true newsreels of > the Nazi processions in Salzburg. The film had a worldwide success, but > failed in Austria. The death of a 67-year old anti-fascist Ernst Kirchweger, > beaten to death on March 31, 1965 during a demonstration against Nazi > professor Taras Borodajkewycz catalysed change.
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Vitamin B12 deficiency causes particular changes to the metabolism of two clinically relevant substances in humans: # Homocysteine (homocysteine to methionine, catalysed by methionine synthase) leading to hyperhomocysteinemia # Methylmalonic acid (methylmalonyl- CoA to succinyl-CoA, of which methylmalonyl-CoA is made from methylmalonic acid in a preceding reaction) Methionine is activated to S-adenosyl methionine, which aids in purine and thymidine synthesis, myelin production, protein/neurotransmitters/fatty acid/phospholipid production and DNA methylation. 5-Methyl tetrahydrofolate provides a methyl group, which is released to the reaction with homocysteine, resulting in methionine. This reaction requires cobalamin as a cofactor. The creation of 5-methyl tetrahydrofolate is an irreversible reaction.
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Dianin's method for preparing bisphenol A from 1891 remains the most widely-known approach to this important compound, though the method has been refined for industrial-scale synthesis. It involves the catalysed condensation of a 2:1 mixture of phenol and acetone in the presence of concentrated hydrochloric acid or sulfuric acid. The reaction proceeds readily at room temperature producing a crude product containing a great variety of side products (including Dianin's compound) in a matter of hours. The overall equation is simple, with water as the only by-product: 700px Mechanistically, the acid catalyst converts the acetone to a carbenium ion that undergoes an electrophilic aromatic substitution reaction with the phenol, producing predominantly para-substituted products.
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In molecular biology, the trappin protein transglutaminase binding domain or cementoin is a protein domain found at the N-terminus of Whey Acidic Protein (WAP) domain-containing protease inhibitors such as trappin-2. This N-terminal domain enables it to become cross-linked to extracellular matrix proteins by transglutaminase. This domain contains several repeated motifs with the consensus sequence Gly-Gln-Asp-Pro-Val-Lys, and these together can anchor the whole molecule to extracellular matrix proteins, such as laminin, fibronectin, beta-crystallin, collagen IV, fibrinogen, and elastin, by transglutaminase- catalysed cross-links. The whole domain is rich in glutamine and lysine, thus allowing transglutaminase(s) to catalyse the formation of an intermolecular epsilon-(gamma-glutamyl)lysine isopeptide bond.
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Singapore's historical roots as a trading settlement gave rise to an influx of foreign traders, and their languages were slowly embedded in Singapore's modern day linguistic repertoire. With the influx of traders into Singapore, Bazaar Malay (Melayu Pasar), a creole of Malay and Chinese, emerged as the lingua franca of the island, which was the language of trade in the Malay Archipelago. However, under the British colonial government, English gained prestige as the language of administration, law and business in Singapore, and eventually displaced Bazar Malay as the bridging language among the population. As government administration increased, infrastructure and commerce developed, and access to education further catalysed the spread of English among Singaporeans.
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Petroleum refining makes intensive use of catalysis for alkylation, catalytic cracking (breaking long-chain hydrocarbons into smaller pieces), naphtha reforming and steam reforming (conversion of hydrocarbons into synthesis gas). Even the exhaust from the burning of fossil fuels is treated via catalysis: Catalytic converters, typically composed of platinum and rhodium, break down some of the more harmful byproducts of automobile exhaust. :2 CO + 2 NO → 2 CO + N With regard to synthetic fuels, an old but still important process is the Fischer-Tropsch synthesis of hydrocarbons from synthesis gas, which itself is processed via water-gas shift reactions, catalysed by iron. Biodiesel and related biofuels require processing via both inorganic and biocatalysts.
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As such they may represent an extension of the concept of human rights. The first seven Millennium Development Goals present measurable goals, while the eighth lists a number of 'stepping stone' goals – ways in which progress towards the first seven goals could be made. Each goal uses indicators based on statistical series collected and maintained by respected organisations in each relevant field (usually the UN agency responsible but also the OECD, IMF and World Bank) The MDGs have catalysed a significant amount of action, including new initiatives such as Millennium Promise. Most of these initiatives however work in small scale interventions which do not reach the millions of people required by the MDGs.
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The play deals with many issues, each stemming from a central theme of poverty: male and female roles in society are tackled through the characters of Maggie, a housewife and John Morrison, who is unemployed (also the overpowering Isa and sexist Lily); the resilience of youth is displayed in the younger children, Edie and Ernest, who cope very well with the conditions; corruption is explored through Alec; the importance of community is apparent through the neighbours, Mrs Wilson, Mrs Bone and Mrs Harris, and through overall interactions in the play, and Jenny Morrison shows growth and the gain of independence. All of these are catalysed somewhat by the overwhelming poverty of the depression.
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An early example of enzyme mimics. Cram's 1976 crown ether acyl transfer catalyst. Breslow's Regioselective Hydrolysis of Cyclic Phosphate Catalysed by Diimidazole-beta-cyclodextrin The term supramolecular chemistry is defined by Jean-Marie Lehn as "the chemistry of intermolecular bond, covering structures and functions of the entities formed by association of two or more chemical species" in his Nobel lecture in 1987, but the concept of supramolecular catalysis was started way earlier in 1946 by Linus Pauling when he founded the theory of enzymatic catalysis in which rate acceleration is the result of non-covalent stabilization of the transition state by the enzymes. Nevertheless, it was not until a few decades later that an artificial enzyme was developed.
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Class II aminoacyl-tRNA synthetases share an anti- parallel beta-sheet fold flanked by alpha-helices, and are mostly dimeric or multimeric, containing at least three conserved regions. However, tRNA binding involves an alpha-helical structure that is conserved between class I and class II synthetases. In reactions catalysed by the class I aminoacyl-tRNA synthetases, the aminoacyl group is coupled to the 2'-hydroxyl of the tRNA, while, in class II reactions, the 3'-hydroxyl site is preferred. The synthetases specific for arginine, cysteine, glutamic acid, glutamine, isoleucine, leucine, methionine, tyrosine, tryptophan and valine belong to class I synthetases; these synthetases are further divided into three subclasses, a, b and c, according to sequence homology.
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Through reflecting on organisms as purposes Kant claims that we are led beyond this topic and thus reflect on nature as a whole. Though teleological judgements are catalysed by our experience of organism the scope of teleological judgements is not limited to organisms but may rather be extended to nature as a whole including organic artefacts. Kant makes two claims regarding the teleology of nature as a whole, first that everything in nature has a purpose and second that nature itself is a system of purposes which also has a purpose. Nature presents itself with cases where features of an organism's environment, both organic and inorganic are both necessary and beneficial for that organism.
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Referring to the slight disturbances to the uniformity of silk screened prints, Warhol said, "I liked the way repetition changes the same image", demonstrating this transformations in the 10 Monroe prints, characteristic of the ink messy process. His apparently random assortment of subjects, is a "careful selection through elimination", of public events or famous figures which convey historic, popular and meaningful connotations. These distinct artistic choices, catalysed his success and recognition, defining him as an artist through these headlined events whilst simultaneously creating an anthology of art pieces that reflect his time. Such endurance was important to Warhol, "the idea is not to live forever, it is to create something that will".
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Such issues catalysed the impending secession: On 7 August 1965, Tunku Abdul Rahman announced to the Malaysian Parliament in Kuala Lumpur that the Parliament should vote yes on the resolution to have Singapore expelled from the Federation, choosing to "sever all ties with a State Government that showed no measure of loyalty to its Central Government" as opposed to the undesirable method of suppressing the PAP for its actions. Singapore's separation and independence became official on 9 August 1965. De jure, Singapore withdrew of its own accord. De facto, however, the PAP had no true authority to influence whether Singapore should leave or not, despite having pressured Tunku Abdul Rahman not to take such a course of action.
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Pu'er undergoes what is known as a solid-state fermentation where water activity is low to negligible. Both endo-oxidation (enzymes derived from the tea-leaves themselves) and exo-oxidation (microbial catalysed) of tea polyphenols occurs. The microbes are also responsible for metabolising the carbohydrates and amino acids present in the tea leaves. Although the microbes responsible have proved highly variable from region to region and even factory to factory, the key organism found and responsible for almost all pu'er fermentation has been identified in numerous studies as Aspergillus niger, with some highlighting the possibility of ochratoxins produced by the metabolism of some strains of A.niger having a potentially harmful effect through consumption of pu'er tea.
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According to Georgia Tech scholar , Nehru's policy on Tibet was to create a strong Sino-Indian partnership which would be catalysed through agreement and compromise on Tibet. Garver believes that Nehru's previous actions had given him confidence that China would be ready to form an "Asian Axis" with India. This apparent progress in relations suffered a major setback when, in 1959, Nehru accommodated the Tibetan religious leader at the time, the 14th Dalai Lama, who fled Lhasa after a failed Tibetan uprising against Chinese rule. The Chairman of the Communist Party of China, Mao Zedong, was enraged and asked the Xinhua News Agency to produce reports on Indian expansionists operating in Tibet.
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The poly-leucine strands demonstrate enzyme-like kinetics with a first-order dependence on and eventual saturation with both the hydroperoxide anion (KM= 30 mM) and the olefin substrate (KM=110 mM.) Kinetic study suggests that the reaction proceeds by random steady-state formation of a ternary (polyleucine+hydroperoxide anion+olefin) complex. Both substrates must bind prior to reaction, and while either may bind first, initial hydroperoxide binding is kinetically preferred. The rapid equilibrium enabling complex formation is followed by the rate- limiting formation of the peroxide enolate (Figure 3).Carrea, G.; Colonna, S.; Meek, A. D.; Ottolina, G.; Roberts, S. M., "Kinetics of chalcone oxidation by peroxide anion catalysed by poly-L-leucine". Chem. Comm.
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Sulfides are typically prepared by alkylation of thiols: :R–Br + HS–R′ → R–S–R′ + HBr Such reactions are usually conducted in the presence of a base, which converts the thiol into the more nucleophilic thiolate. Analogously, the reaction of disulfides with organolithium reagents produces thioethers: : R3CLi + R1S–SR2 → R3CSR1 \+ R2SLi Analogous reactions are known starting with Grignard reagents. Alternatively, sulfides can be synthesized by the addition of a thiol to an alkene in the thiol-ene reaction: :R–CH=CH2 \+ HS–R′ → R–CH2–CH2–S–R′ This reaction is often catalysed by free radicals produced from a photoinitiator. Sulfides can also be prepared by many other methods, such as the Pummerer rearrangement.
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Its > influence has been very great indeed as it fermented an intense debate about > these topics, and catalysed a new set of concepts in paleoanthropology. Several scientists credit Ardrey's work, and African Genesis in particular, with launching them into their studies. Paleoanthropologist Rick Potts, who has been the director of the Smithsonian Institution Museum of Natural History's Human Origins Program since 1985 points to African Genesis as one of the two most formative books of his early years. In the 2015 PBS film documentary Dawn of Humanity, Potts recites the beginning of the book from memory.Dawn of Humanity - 2015 PBS documentary film In 1972, defending his film A Clockwork Orange from Fred M. Hechinger, Stanley Kubrick cited Ardrey.
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Glutamate undergoes deamination, an oxidative reaction catalysed by glutamate dehydrogenase, as follows: : glutamate + H2O + NADP+ → α-ketoglutarate + NADPH + NH3 \+ H+ Ammonia (as ammonium) is then excreted predominantly as urea, synthesised in the liver. Transamination can thus be linked to deamination, effectively allowing nitrogen from the amine groups of amino acids to be removed, via glutamate as an intermediate, and finally excreted from the body in the form of urea. Glutamate is also a neurotransmitter (see below), which makes it one of the most abundant molecules in the brain. Malignant brain tumors known as glioma or glioblastoma exploit this phenomenon by using glutamate as an energy source, especially when these tumors become more dependent on glutamate due to mutations in the gene IDH1.
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The Hajos–Parrish–Eder–Sauer–Wiechert reaction in organic chemistry is a proline catalysed asymmetric aldol reaction. The reaction is named after its principal investigators, Zoltan Hajos others, from Hoffmann-La RocheZ. G. Hajos, D. R. Parrish, German Patent DE 2102623 1971 and Schering AG. Discovered in the 1970s the original Hajos-Parrish catalytic procedure - shown in the reaction equation - leading to the optically active bicyclic ketol as well as the Eder-Sauer-Wiechert modification leading to the optically active enedione through the loss of water from the ketol paved the way of asymmetric organocatalysis. It has been used extensively as a tool in the synthesis of steroids and other enantiomerically pure molecules.Zerong Wang in Comprehensive Organic Name Reactions and Reagents, 3V Set, p.
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Merle Elecia Parkes (born 19 May 1927) was a pioneer nurse educator who spent the bulk of her extensive career championing quality education for nurses in Australia. Parkes was eventually instrumental in affecting change from solely hospital-only training, to formal nursing degrees within tertiary institutions. In 1979, under Parkes's guidance, the Western Australian Institute of Technology (later Curtin University of Technology) became the first Australian tertiary institution to receive approval for a nursing degree program, which catalysed a National shift from hospital-based training to university-based education for the nursing profession. Parkes received her initial nursing training in New South Wales, before moving to Western Australia in 1962, and subsequently to Tasmania in 1983 for the remainder of her career.
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103 The complex array of motives and causes that culminated in the mutiny of much of the Bengal Army would be catalysed in 1857 by rumours that beef and pork fat was being used to grease paper rifle cartridges. Confined first to a number of Bengal regiments, the mutiny eventually manifested in some areas as a more diverse, albeit disparate, rebellion against British rule.Parsons (1999), pp. 45-6Mileham (2000), p. 49 Soon after reports were received of the first mutiny at Meerut on 10 May, the 8th's commanding officer, Lieutenant-Colonel Richard Hartley, had two companies secure the fort of Phillaur, near Jullundur, due to the significance of its magazine stores and reports that the 3rd Bengal Native Infantry intended to seize it.
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The goal of Henri's thesis was to compare his knowledge of enzyme-catalysed reactions to the recognized laws of physical chemistry. Henri is credited with being the first to write the equation that is now known as the Michaelis-Menten equation. Using glucose and fructose in the catalytic reactions controlled by maltase and invertase, Leonor Michaelis was the first scientist to distinguish the different types of inhibition by using the pH scale which did not exist in Henri's time. Particularly during their work on describing the rate of this reaction they also tested and extrapolated on the idea of another scientist, Victor Henri, that enzyme they were using had some affinity for both products of this reaction – fructose and glucose.
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' is a neurological syndrome caused by severe mercury poisoning. Identical in symptoms to the original outbreak of Minamata disease in Kumamoto Prefecture, the second outbreak in Niigata Prefecture was confirmed with the same name in 1965. The disease was caused by severe mercury poisoning, the source of which was methylmercury released in the wastewater from mercury sulfate-catalysed acetaldehyde production at the Showa Electrical Company's chemical plant in Kanose village. This highly toxic compound was released untreated into the Agano River where it bioaccumulated up the food chain, contaminating fish which when eaten by local people caused symptoms including ataxia, numbness in the hands and feet, general muscle weakness, narrowing of the field of vision and damage to hearing and speech.
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In recent years, a great deal of evidence has been produced that supports the conclusion that GTN's clinically relevant denitration and reduction produce 1,2-glyceryl dinitrate (GDN) and NO, and that this reaction is catalysed by mitochondrial aldehyde dehydrogenase (ALDH2 or mtALDH). The NO produced by this process is a potent activator of guanylyl cyclase (GC) by heme-dependent mechanisms; this activation results in formation of cyclic guanosine monophosphate (cGMP) from guanosine triphosphate (GTP). Among other roles, cGMP serves as a substrate for a cGMP-dependent protein kinase that activates myosin light chain phosphatase. Thus, production of NO from exogenous sources such as GTN increases the level of cGMP within the cell, and stimulates dephosphorylation of myosin, which initiates relaxation of smooth muscle cells in blood vessels.
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In the proposed mechanism for Pr6O11-catalysed oxidation of CO to CO2, CO first binds to the catalyst surface to create a bidentate carbonate then converted to a monodentate carbonate species which can now decompose as CO2, completing the catalyst cycle. The conversion of a bidentate carbonate to a monodentate species leaves an oxygen vacancy on the catalyst surface which can quickly be filled due to the high oxygen mobility deriving from the mixed oxidation states of Pr centres. This proposed mechanism is presented schematically below, adapted from Borchert, et. al. Praseodymium oxide- catalyzed CO oxidation mechanism Addition of gold promoters to the catalyst may significantly lower the reaction temperature from 550 °C to 140 °C, but the mechanism is yet to be discovered.
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After its drought-breaking finals appearance the previous year, Richmond failed to live up to expectations in the first half of the 2014 season, losing 10 of its first 13 matches and dropping to 16th place on the ladder. Despite public sentiment that the season was lost, the club rallied behind a five-goal performance by Cotchin to win against St Kilda. It catalysed a nine-match winning streak, with a Round 23 victory against eventual grand-finalists Sydney raising Richmond to 8th on the ladder and putting the club into its first back-to-back finals appearance since 1975. A 57-point loss to Port Adelaide in an elimination final knocked Richmond out in the first week of the finals.
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In enzymology, a precorrin-6Y C5,15-methyltransferase (decarboxylating) () is an enzyme that catalyzes the chemical reaction :2 S-adenosyl-L-methionine + precorrin-6Y \rightleftharpoons 2 S-adenosyl-L-homocysteine + precorrin-8X + CO2 The conversion of precorrin-6B to precorrin-8 is catalysed by the enzyme CobL in Pseudomonas denitrificans The two substrates of this enzyme are S-adenosyl methionine and precorrin 6Y; its three products are S-adenosylhomocysteine, precorrin 8X, and CO2. This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L- methionine:1-precorrin-6Y C5,15-methyltransferase (C-12-decarboxylating). Other names in common use include precorrin-6 methyltransferase, precorrin-6Y methylase and CobL.
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This conversion of UV light into kinetic energy warms the stratosphere. The oxygen atoms produced in the photolysis of ozone then react back with other oxygen molecule as in the previous step to form more ozone. In the clear atmosphere, with only nitrogen and oxygen, ozone can react with the atomic oxygen to form two molecules of O2 : + O → 2 An estimate of the rate of this termination step to the cycling of atomic oxygen back to ozone can be found simply by taking the ratios of the concentration of O2 to O3. The termination reaction is catalysed by the presence of certain free radicals, of which the most important are hydroxyl (OH), nitric oxide (NO) and atomic chlorine (Cl) and bromine (Br).
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Anzac Memorial Avenue is important in illustrating the early stages of this phase in the development of Queensland's road network. As the first bitumen motor road from a major urban centre to a seaside resort, Anzac Memorial Avenue is important in demonstrating the growth of car based tourism in Queensland in the 1920s and illustrates the growing importance of car access to the development of tourist resorts. Anzac Memorial Avenue catalysed the growth of Redcliffe as a major seaside resort for south- east Queensland during the interwar period. Built under a government policy designed to promote the development of roads that opened up areas for economic development, the Avenue demonstrates the increasing importance of tourism to the Queensland economy at the time.
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Since the reaction catalysed by HMG-CoA reductase is the rate-limiting step in cholesterol synthesis, this enzyme represents the sole major drug target for contemporary cholesterol-lowering drugs in humans. The medical significance of HMG-CoA reductase has continued to expand beyond its direct role in cholesterol synthesis following the discovery that statins can offer cardiovascular health benefits independent of cholesterol reduction. Statins have been shown to have anti-inflammatory properties, most likely as a result of their ability to limit production of key downstream isoprenoids that are required for portions of the inflammatory response. It can be noted that blocking of isoprenoid synthesis by statins has shown promise in treating a mouse model of multiple sclerosis, an inflammatory autoimmune disease.
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Under Masade-Olowola, CSR-in-Action has promoted sustainable measurement and reporting using the GRI framework, specifically, since 2011, and has catalysed the growth of sustainability adoption and transparency in the region through consulting, training and advocacy interventions. CSR-in- Action produced the pioneer sustainability investment report in Nigeria The Collective Social Report: Nigeria (now The Corporate Sustainable Investor Report), endorsed by the United Nations Framework Convention on Climate Change (UNFCCC), and supported by United Nations Global Compact (UNGC), in March 2012; a first of its kind compendium which includes a rating of business sustainability performance. The 2013 report saw the organization's introduction of a sustainability ranking index. In 2014, CSR-in-action was lobbying to unlock over $100 billion in mineral resources potential.
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For example, ethyl diazoacetate is converted to diethyl maleate using the ruthenium catalyst chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium:Highly stereoselective formation of cis-enediones from α-diazo carbonyl compounds catalysed by [RuCl(η5-C5H5)(PPh3)2] Walter Baratta and Alessandro Del Zotto Chem. Commun., 1997, 2163-2164 :Carbene dimerization Baratta 1997 Grubbs' catalyst is also effective Maleates from diazoacetates and dilactones from head-to-head dimerisation of alkenyl diazoacetates using Grubbs' 2nd- generation ruthenium carbene catalyst David M. Hodgson and Deepshikha Angrish Chem. Commun., 2005, 4902-4904 In this reaction type the active intermediate is a transition metal carbene complex. A diazo cross-coupling reaction has also been reported between ethyl diazoacetate and methyl phenyldiazoacetate using the rhodium catalyst [Rh2(OPiv)4].
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The > Federation will be entitled to a share in the state taxes to meet its > expenditures. # There should be two separate accounts for the foreign > exchange earnings of the two wings; the foreign exchange requirements of the > federal government should be met by the two wings equally or in a ratio to > be fixed; indigenous products should move free of duty between the two > wings, and the constitution should empower the units to establish trade > links with foreign countries. # East Pakistan should have a separate militia > or paramilitary forces. Mujib's points catalysed public support across East Pakistan, launching what some historians have termed the 6-point movement – recognized as the definitive gambit for autonomy and rights of Bengalis in Pakistan.
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An early instance of fragmentation is the dehydration of di(tert-butyl)methanol yielding 2-methyl-2-butene and isobutene, a reaction described in 1933 by Frank C. Whitmore. This reaction proceeds by formation of a secondary carbocation followed by a rearrangement reaction to a more stable tertiary carbocation and elimination of a t-butyl cation: Fragmentation Whitmore Albert Eschenmoser in 1952 investigated the base catalysed fragmentation of certain beta hydroxy ketones: Fragmentation Eschenmoser 1952 The original work by Grob (1955) concerns the formation of 1,5-hexadiene from cis- or trans-1,4-dibromocyclohexane by sodium metal: Grob fragmentation 1955 According to reviewers Prantz and Mulzer (2010), the name Grob fragmentation was chosen "in more or less glaring disregard of the earlier contributions".
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These pre- pseudopilins consist of an N-terminal signal sequence that targets the proteins to the Sec translocon and a long C-terminal passenger domain which encodes the actual pseudopilin protein itself. Once the Sec machinery has transported the pre-pseudopilin across the inner membrane, but before the protein itself is released into the periplasm, the N-terminal signal sequence is cleaved at a conserved stretch of positively charged amino acid residues. This cleavage is catalysed by the signal peptidase GspO and the end result is the removal of the N-terminal signal sequence and the formation of a mature pseudopilin. GspO is inserted in the inner membrane and is often closely associated with the type II secretion system machinery.
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First, a new information carrier Inew created by the mutation must be better recognized by one of the hypercycle's members Ii than the chain Ii+1 that was previously recognized by it. Secondly, the new member Inew of the cycle has to better catalyse the formation of the polynucleotide Ii+1 that was previously catalysed by the product of its predecessor Ii. In theory, it is possible to incorporate into the hypercycle mutations that do not satisfy the second condition. They would form parasitic branches that use the system for their own replication but do not contribute to the system as a whole. However, it was noticed that such mutants do not pose a threat to the hypercycle, because other constituents of the hypercycle grow nonlinearly, which prevents the parasitic branches from growing.
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2-keto-3-deoxy-6-phosphogluconate, a product of the reaction catalysed by phosphogluconate dehydratase In enzymology, a phosphogluconate dehydratase () is an enzyme that catalyzes the chemical reaction :6-phospho-D-gluconate \rightleftharpoons 2-dehydro-3-deoxy-6-phospho-D-gluconate + H2O Hence, this enzyme has one substrate, 6-phospho-D-gluconate, and two products, 2-dehydro-3-deoxy-6-phospho-D-gluconate and H2O. This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is 6-phospho-D-gluconate hydro-lyase (2-dehydro-3-deoxy-6-phospho-D-gluconate-forming). Other names in common use include 6-phosphogluconate dehydratase, 6-phosphogluconic dehydrase, gluconate-6-phosphate dehydratase, gluconate 6-phosphate dehydratase, 6-phosphogluconate dehydrase, and 6-phospho-D-gluconate hydro- lyase.
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Plüg and Wentrup developed a method in 1997 that improved on FVT reactions to produce ketenes with a stable FVT that is moisture insensitive, using mild conditions (480 °C). The N-pyridylamines are prepared via a condensation with R-malonates with N-amino(pyridene) and DCC as the solvent. A more robust method for preparing ketenes is the carbonylation of metal-carbenes, and in situ reaction of the thus produced highly reactive ketenes with suitable reagents such as imines, amines, or alcohols. This method is an efficient one‐pot tandem protocol of the carbonylation of α‐diazocarbonyl compounds and a variety of N‐tosylhydrazones catalysed by Co(II)–porphyrin metalloradicals leading to the formation of ketenes, which subsequently react with a variety of nucleophiles and imines to form esters, amides and β‐lactams.
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In 1997, Wilders was elected for the People's Party for Freedom and Democracy (VVD) to the municipal council of Utrecht, the fourth largest city of the Netherlands. He lived in Kanaleneiland, a suburb with cheap social housing and high apartment blocks, which has a relatively high number of immigrants. While a city councilor, Wilders was mugged in his own neighbourhood; some have speculated that this may have catalysed his political transformation. He was not rewarded for his time on the municipal council of Utrecht, for in the following elections he would score well below the national average in the University city. Europese verkiezingen 2009 (Gemeente Utrecht, 6 July 2009) A year later, he was elected to the Netherlands' national parliament, but his first four years in parliament drew little attention.
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The helicopter incident catalysed more concerted Russian military intervention on behalf of the Abkhazian side. As the Abkhazian troops intensified their efforts to take hold of the zone around Abkhazia's capital Sukhumi in early 1993, the fighting for Tkvarcheli also became fiercer and spilled over into the neighbouring villages when the besieged Abkhazian troops attempted several sorties. In February 1993, Abkhaz fighters attacked the Georgian village of Kvirauri, just outside Tkvarcheli, and took some 500 civilians hostage, threatening to kill them unless Georgian forces ended their offensive in the neighbouring Ochamchira district.HRW (1995), p. 28. A temporary ceasefire allowed the Russians to carry out the largest humanitarian operation in Tkvarcheli on June 16, 1993, evacuating several hundreds of civilians with 30 Kamaz trucks and 2 buses through the corridor offered by the Georgian army.
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The success of Mark 9 was impressive, and the device's superior sensitivity impressed its purchasers, so much so that a senior director from Unilever, who had purchased a device for his own boat, asked whether a variant could be made to detect ammonia. This catalysed the company's transition into more sophisticated markets and industries that required Intrinsically Safe (IS) devices, with the release of Mark 7; a modified variant of Mark 9 designed to meet Unilever's specific requirements. By June 1961, a decision was made to manufacture in-house, and a new building was purchased in Poole, Dorset. IEC still carried out the sales and marketing of the products initially, but as the months passed, Sieger decided that the products being produced required more technical, engineering-based selling techniques to maximise market potential.
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Björk released her previous studio album Debut in 1993, on One Little Indian Records. A main element of Debuts sound was its incorporation of dance music, reflecting the contemporary styles of England's underground club culture, with which Björk had established close ties—as reflected in the remixes of the Debut and Post eras, and her romantic pairings with electronic musicians during this period, such as Goldie (with whom Björk was briefly engaged). Björk's adoption of "the contemporary musical environment of London" also included the burgeoning trip hop scene of bands like Portishead and Massive Attack. Nellee Hooper, who produced the album, had been a member of Bristol's Wild Bunch collective, a group that took from acid jazz, funk and hip hop, and catalysed the appearance of trip hop.
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The film begins with the airing of a knife fight at Lucy's (Madeleine Garrood) initial public school, where she was located footsteps away from the scene of violence. This event induces fear in her parents Stuart (Christopher Eccleston) and Alison (Susannah Harker) and subsequently catalysed her parents' search for a safer and well-renown school and her eventual departure from that public school. Subsequently, it follows the story of a little girl named Lucy and her atheist-based upbringing in her parents' pursuit of superior educational development for their child. After a thorough search, the only better alternative they could afford was St Mary of the Veil, which is managed by a group of nuns with a preference for traditional Catholic families to maintain their exclusivity, given the lengthy enrolment waiting lists.
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4-OH-E2 shares the metabolic scheme of 2-OH-E2: methylation to 4-methoxyestradiol (4-meOE2), oxidation to quinones, or dehydrogenation to 4-OH-E1. Conjugation by the ubiquitously present COMT represents the most common extrahepatic pathway of 4-OH-E2 inactivation. However, if estrogen homeostasis is imbalanced by an increase in CYP1B1 and a decrease in COMT, a greater degree of genotoxic quinone formation from 4-OH-E2 will occur. 4-OHE2 can be oxidized by microsomal CYPs or peroxidases to yield estradiol-3,4-semiquinone. This semiquinone can undergo redox cycling with oxygen to form estradiol-3,4-quinone (E2-3,4-Q) and superoxide. E2-3,4-Q can be converted back to 4-OHE2 in a single step by quinone reductase, or in two sequential steps catalysed by P450 reductase via the semiquinone intermediate.
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Families of deceased and congenital patients received JPY10 million, surviving patients were awarded between JPY1 million and 10 million depending on symptoms, JPY400,000 to those contaminated by mercury, and JPY300,000 were awarded to pregnant women who had been told to have abortions due to the danger posed to their unborn children.George, pp246-247 A family member of the deceased patient testified in court, "My father was crazed like a wild beast and then died—agonized, in pain... like a dog." The events in Niigata catalysed a change in response to the original Minamata incident. The scientific research carried out in Niigata forced a re- examination of that done in Minamata and the decision of Niigata patients to sue the polluting company allowed the same response to be considered in Minamata.
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Certain allyl silanes can be prepared from allylic esters such as 1 and monosilylcopper compounds such as 2, in:Mechanistic insight into copper- catalysed allylic substitutions with bis(triorganosilyl) zincs. Enantiospecific preparation of -chiral silanes Eric S. Schmidtmann and Martin Oestreich Chem. Commun., 2006, 3643–3645, By isotopic desymmetrisation on the substrate (replacing hydrogen by deuterium) it can be demonstrated that the reaction proceeds not through the symmetrical π-allyl intermediate 5 which would give an equal mixture of 3a and 3b but through the Π-δ intermediate 4 resulting in 3a only, through an oxidative addition or reductive elimination step :Allylic substitution forming an allyl silane In this reaction type, silicon polarity is reversed in a chemical bond with zinc and a formal allylic substitution on the benzoyloxy group takes place.
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Ricin molecules are thought to follow retrograde transport via early endosomes, the trans-Golgi network, and the Golgi to enter the lumen of the endoplasmic reticulum (ER). For ricin to function cytotoxically, RTA must be reductively cleaved from RTB to release a steric block of the RTA active site. This process is catalysed by the protein PDI (protein disulphide isomerase) that resides in the lumen of the ER. Free RTA in the ER lumen then partially unfolds and partially buries into the ER membrane, where it is thought to mimic a misfolded membrane-associated protein. Roles for the ER chaperones GRP94, EDEM and BiP have been proposed prior to the 'dislocation' of RTA from the ER lumen to the cytosol in a manner that uses components of the endoplasmic reticulum-associated protein degradation (ERAD) pathway.
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The ‘Tri Hita Karana (THK) Forum for Sustainable Development’ with the theme of ‘Blended Finance and Innovation for Better Business Better World’ was launched in Bali around the 2018 IMF World Bank Annual Meetings. It takes place every two years. Held under the patronage of the Government of Indonesia, the aim of the THK Forum is to accelerate global action for the UN Sustainable Development Goals with the use of blended financing to mobilize private sector engagement. The first forum launched over 30 high impact projects, and mobilized up to US$10 billion for priority SDGs sectors including green infrastructure, sustainable land use, oceans, women, ecotourism and innovation in Indonesia and globally. Notable initiatives launched or catalysed by the THK Forum include: # A first-of-its-kind integrated funding platform “SDG Indonesia One”.
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The Tsuji–Trost reaction (also called the Trost allylic alkylation or allylic alkylation) is a palladium-catalysed substitution reaction involving a substrate that contains a leaving group in an allylic position. The palladium catalyst first coordinates with the allyl group and then undergoes oxidative addition, forming the -allyl complex. This allyl complex can then be attacked by a nucleophile, resulting in the substituted product.Strategic Applications of Named Reactions in Organic Synthesis (Paperback) by Laszlo Kurti, Barbara Czako Tsuji–Trost allylation This work was first pioneered by Jiro Tsuji in 1965Organic syntheses by means of noble metal compounds XVII. Reaction of -allylpalladium chloride with nucleophiles Tetrahedron Letters, Volume 6, Issue 49, 1965, Pages 4387-4388 Jiro Tsuji, Hidetaka Takahashi, Masanobu Morikawa and, later, adapted by Barry Trost in 1973 with the introduction of phosphine ligands.
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Unlike his brother Zakir Husain, Mahmud Husain had been a strong proponent of the Pakistan Movement, and catalysed support for Pakistan among students in East Bengal and at Dhaka University. On Direct Action Day in 1946, Husain was charged with leading the pro-Pakistan rally in Dhaka.Mahmud Husain's interview to Radio Pakistan on YouTube He was elected Member of the first Constituent Assembly of Pakistan from East Bengal on the platform of Muslim League,First Constituent Assembly of Pakistan (1947-1954) Government of Pakistan website, Retrieved 30 August 2019 and also elected Secretary of the Muslim League's Parliamentary Group. He was appointed both Deputy Minister of Defense and Foreign Affairs in the cabinet of Prime Minister Liaquat Ali Khan in 1949, before becoming State Minister for State and Frontier Regions a year later.
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In phase I, a variety of enzymes act to introduce reactive and polar groups into their substrates. One of the most common modifications is hydroxylation catalysed by the cytochrome P-450-dependent mixed-function oxidase system. These enzyme complexes act to incorporate an atom of oxygen into nonactivated hydrocarbons, which can result in either the introduction of hydroxyl groups or N-, O- and S-dealkylation of substrates. The reaction mechanism of the P-450 oxidases proceeds through the reduction of cytochrome- bound oxygen and the generation of a highly-reactive oxyferryl species, according to the following scheme: :O2 \+ NADPH + H+ \+ RH → NADP+ \+ H2O + ROH Phase I reactions (also termed nonsynthetic reactions) may occur by oxidation, reduction, hydrolysis, cyclization, decyclization, and addition of oxygen or removal of hydrogen, carried out by mixed function oxidases, often in the liver.
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The turbocharged version of the 'banana' engine was fitted with electronic fuel injection sourced from Lucas Industries, while the non- turbocharged version had a mechanical system. The Ford Duratorq electronically controlled direct injection diesel engine appearing in 2002 (sourced from the Ford Transit, and described as 'not smooth') was fitted with a non-optional turbocharger, this was available with an optional intercooler, increasing the peak power output from 75PS to 90PS. All engines were catalysed and were fitted with a drive-by-wire throttle setup that was criticised as dangerous, and adjustable air suspension was available as an optional extra on long- wheelbase diesel models. A factory LPG conversion (using an underfloor LPG tank and a rear-mounted petrol tank) was also available using a converted Ford eight-valve petrol engine with a peak power output of 115PS.
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The adaptor hypothesis is part of a scheme to explain how information encoded in DNA is used to specify the amino acid sequence of proteins. It was formulated by Francis Crick in the mid-1950s, together with the central dogma of molecular biology and the sequence hypothesis. It first appeared in an informal publication of the RNA Tie Club in 1955 and was formally published in an article “On Protein Synthesis” in 1958. ;Explanation The adaptor hypothesis was framed to explain how information could be extracted from a nucleic acid and used to put together a string of amino acids in a specific sequence, that sequence being determined by the nucleotide sequence of the nucleic acid (DNA or RNA) template. Crick proposed that each amino acid is first attached to its own specific “adaptor” piece of nucleic acid (in an enzyme-catalysed reaction).
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In 1880 Joseph Achille Le Bel and William H. Greene reported what has been described as an "extraordinary" zinc chloride- catalysed one-pot synthesis of hexamethylbenzene from methanol. At the catalyst's melting point (283 °C), the reaction has a Gibbs free energy (ΔG) of −1090 kJ mol−1 and can be idealised as: :15 → \+ 3 \+ 15 Le Bel and Greene rationalised the process as involving aromatisation by condensation of methylene units, formed by dehydration of methanol molecules, followed by complete Friedel–Crafts methylation of the resulting benzene ring with chloromethane generated in situ. The major products were a mixture of saturated hydrocarbons, with hexamethylbenzene as a minor product. Hexamethylbenzene is also produced as a minor product in the Friedel–Crafts alkylation synthesis of durene from p-xylene, and can be produced by alkylation in good yield from durene or pentamethylbenzene.
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The customer could only choose between two paint schemes: silver or red, both paired to the lower half of the body in contrasting metallic gunmetal grey. In the same year, the 2.5-litre Biturbo 2500 or Biturbo E (for Export) was also introduced, and was joined some twelve months later by the Biturbo ES with power outputs , respectively in European- or catalysed US-specification. In 1985, all models received updates and were renamed Biturbo II, Biturbo S II and Biturbo E II. The cylinders were now Nikasil-coated, a more capacious fuel tank was fitted and a Sensitork limited slip differential replaced the earlier Salisbury clutch-type. The second series of the Biturbo was recognizable by its new 6"Jx14" wheels similar in design to the Biturbo S wheels; the S II wheels had fully painted faces, without the silver center.
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The Heck–Matsuda (HM) reaction is an organic reaction and a type of palladium catalysed arylation of olefins that uses arenediazonium salts as an alternative to aryl halides and triflates. The use of arenediazonium salts presents some advantages over traditional aryl halide electrophiles, for example, the use of phosphines as ligand are not required and thus negating the requirement for anaerobic conditions, which makes the reaction more practical and easier to handle. Additionally, the reaction can be performed with or without a base and is often faster than traditional Heck protocols. HM faster than Heck Allylic alcohols, conjugated alkenes, unsaturated heterocycles and unactivated alkenes are capable of being arylated with arenediazonium salts using simple catalysts such as palladium acetate (Pd(OAc)2) or tris(dibenzylideneacetone)dipalladium(0) (Pd2dba3) at room temperature in air, and in benign and conventional solvents.
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The major cause of benzene in soft drinks is the decarboxylation of benzoic acid in the presence of ascorbic acid (vitamin C, E300) or erythorbic acid (a diastereomer of ascorbic acid, E315). Benzoic acid is often added to drinks as a preservative in the form of its salts sodium benzoate (E211), potassium benzoate (E 212), or calcium benzoate (E 213). Citric acid is not thought to induce significant benzene production in combination with benzoic acid, but some evidence suggests that in the presence of ascorbic or erythorbic acid and benzoic acid, citric acid may accelerate the production of benzene. The proposed mechanism begins with hydrogen abstraction by the hydroxyl radical, which itself is produced by the Cu2+-catalysed reduction of dioxygen by ascorbic acid: 900px Other factors that affect the formation of benzene are heat and light.
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Vitamin B12 (cobalamin) is used as a cofactor in a number of enzyme-catalysed reactions in bacteria, archaea and eukaryotes. The biosynthetic pathway to adenosylcobalamin from its five- carbon precursor, 5-aminolaevulinic acid, can be divided into three sections: (1) the biosynthesis of uroporphyrinogen III from 5-aminolaevulinic acid; (2) the conversion of uroporphyrinogen III into the ring-contracted, deacylated intermediate precorrin 6 or cobalt-precorrin 6; and (3) the transformation of this intermediate to form adenosylcobalamin. Cobalamin is synthesised by bacteria and archaea via two alternative routes that differ primarily in the steps of section 2 that lead to the contraction of the macrocycle and excision of the extruded carbon molecule (and its attached methyl group). One pathway (exemplified by Pseudomonas denitrificans) incorporates molecular oxygen into the macrocycle as a prerequisite to ring contraction, and has consequently been termed the aerobic pathway.
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Labour's incremental embrace of a distinctive Welsh polity was arguably catalysed in 1966 when Plaid Cymru president Gwynfor Evans won the Carmarthen by-election (although in fact Labour had endorsed plans for an elected council for Wales weeks before the by-election). However, by 1967 Labour retreated from endorsing home rule mainly because of the open hostility expressed by other Welsh Labour MPs to anything "which could be interpreted as a concession to nationalism" and because of opposition by the Secretary of State for Scotland, who was responding to a growth of Scottish nationalism. In response to the emergence of Plaid Cymru and the Scottish National Party (SNP) Harold Wilson's Labour Government set up the Royal Commission on the Constitution (the Kilbrandon Commission) to investigate the UK's constitutional arrangements in 1969.Devolution in the UK: Department for Constitutional Affairs.
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The origins of the INTEGER Millennium House date to a May 1996 seminar about green building, which catalysed the formation of the INTEGER building design and consultancy team to "evaluate available design and technical solutions to improve housing performance". The efforts of this design team resulted in the creation of a scale model of a house, which has subsequently been widely exhibited at institutions such as the Science Museum, London as well as profiled in the DK Eyewitness Book Future. Damian Bree, Tim Day, Paul Hodgkins, and Nicholas Thompson began designing the INTEGER Millennium House itself in October 1997, a process that proceeded for 10 weeks. Built on the Building Research Establishment (BRE)'s Innovation Park property in Garston, Watford, the actual construction of the house took 13 weeks before it opened to the public in 1998.
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Sir John Warcup Cornforth Jr., AC, CBE, FRS, FAA (7 September 1917 – 8 December 2013) was an AustralianBritish chemist who won the Nobel Prize in Chemistry in 1975 for his work on the stereochemistry of enzyme-catalysed reactions, becoming the only Nobel laureate born in New South Wales. Cornforth investigated enzymes that catalyse changes in organic compounds, the substrates, by taking the place of hydrogen atoms in a substrate's chains and rings. In his syntheses and descriptions of the structure of various terpenes, olefins, and steroids, Cornforth determined specifically which cluster of hydrogen atoms in a substrate were replaced by an enzyme to effect a given change in the substrate, allowing him to detail the biosynthesis of cholesterol.Deaf Scientist Corner – John Warcup Cornforth, Texas Woman's University For this work, he won a share of the Nobel Prize in Chemistry in 1975, alongside co-recipient Vladimir Prelog, and was knighted in 1977.
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By that time, most UK government departments had set up their own offices in Wales. The Labour Party had also partly reappraised its view to devolution, establishing in 1947 the Welsh Regional Council of Labour from the constituent parts of the party in Wales and as part of a move to plan the economy on an all-Wales basis. However, resistance from other elements of the party meant that the machinery of government was not similarly reformed until much later. The post of Minister of Welsh Affairs was first established in 1951, but was at first held by the UK Home Secretary. Further incremental changes also took place, including the establishment of a Digest of Welsh Statistics in 1954, and the designation of Cardiff (Caerdydd) as Wales's capital city in 1955. However, further reforms were catalysed partly as a result of the controversy surrounding the flooding of Capel Celyn in 1956.
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The chlorin ring system forms as the esterified propionate sidechain is cyclised on to the main porphyrin ring to form divinylprotochlorophyllide The chlorin ring system features a five-membered carbon ring E is created when one of the propionate groups of the porphyrin is cyclised to the carbon atom linking the original pyrrole rings C and D. A series of chemical steps catalysed by the enzyme Magnesium-protoporphyrin IX monomethyl ester (oxidative) cyclase gives the overall reaction : Mg-protoporphyrin IX 13-monomethyl ester + 3 NADPH + 3 H+ \+ 3 O2 \rightleftharpoons divinylprotochlorophyllide + 3 NADP+ \+ 5 H2O In barley the electrons are provided by reduced ferredoxin, which can obtain them from photosystem I or, in the dark, from Ferredoxin—NADP(+) reductase: the cyclase protein is named XanL and is encoded by the Xantha-l gene. In anaerobic organisms such as Rhodobacter sphaeroides the same overall transformation occurs but the oxygen incorporated into magnesium- protoporphyrin IX 13-monomethyl ester comes from water in the reaction .
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The C–OH bond of a tautomerizable heterocycle is activated with a phosphonium salt (PyBroP, PyBOP, BroP, or BOP), and subsequent functionalization with either a nucleophile through SNAr displacement or an organometallic through transition metal catalyzed cross coupling reaction. The in situ activation of the C-OH bond in phosphonium coupling has been applied to cross coupling reactions of tautomerizable heterocycles and arenols using other types of activating reagents. Phosphonium coupling generates in situ a pseudo aryl or heteroaryl halide (the intermediate phosphonium species), which subsequently reacts with its coupling partner.Chinchilla, Rafael; Najera, Carmen, Recent advances in Sonogashira reactions, Chemical Society Reviews (2011), 40(10), 5084-5121. Sellars, Jonathan D.; Steel, Patrick G., Transition metal-catalysed cross- coupling reactions of P-activated enols, Chemical Society Reviews (2011), 40(10), 5170-5180. Li, Bi-Jie; Yu, Da-Gang; Sun, Chang-Liang; Shi, Zhang-Jie, Activation of "Inert" Alkenyl/Aryl C=O Bond and Its Application in Cross- Coupling Reactions, Chemistry--A European Journal (2011), 17(6), 1728-1759.
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The 1990s opened a new page in the history of the development of ECCE catalysed mainly by the rapid and successive ratification of the 1989 United Nations Convention on the Rights of the Child (CRC). By its explicit mention of 'the child' – meaning every human being under the age of eighteen or majority – the CRC reinforced the 1960 UNESCO Convention and Recommendation against Discrimination in Education which should have covered young children in any case. With its moral force and near universal ratification, the CRC formally recognized children as holders of rights to survival and development, to be heard and to participate in decisions affecting them in accordance with their evolving capacities with their best interests and non-discrimination as overarching principles. While the CRC in Article 18 also recognizes the primary role of parents and legal guardians in the upbringing and development of children, it obliges States Parties to help them carry out these duties.
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Phenol-formaldehyde resins, as a group, are formed by a step-growth polymerization reaction that can be either acid- or base- catalysed. Since formaldehyde exists predominantly in solution as a dynamic equilibrium of methylene glycol oligomers, the concentration of the reactive form of formaldehyde depends on temperature and pH. Phenol reacts with formaldehyde at the ortho and para sites (sites 2, 4 and 6) allowing up to 3 units of formaldehyde to attach to the ring. The initial reaction in all cases involves the formation of a hydroxymethyl phenol: : HOC6H5 \+ CH2O → HOC6H4CH2OH The hydroxymethyl group is capable of reacting with either another free ortho or para site, or with another hydroxymethyl group. The first reaction gives a methylene bridge, and the second forms an ether bridge: : HOC6H4CH2OH + HOC6H5 → (HOC6H4)2CH2 \+ H2O : 2 HOC6H4CH2OH → (HOC6H4CH2)2O + H2O The diphenol (HOC6H4)2CH2 (sometimes called a "dimer") is called bisphenol F, which is an important monomer in the production of epoxy resins.
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The non-orthodox variants of the Bhakti movement, that aligned with the Sahajiya tradition and sought to encompass the downtrodden sections into the society, also catalysed the Namasudras, as a guiding faith. Various local socio-religious figureheads (Kalachand Vidyalankar, Sahlal Pir, Keshab Pagal et al.), who sought to repudiate the caste system, further impressed upon large sections of the Namasudra population. The Namasudras, thus, successfully strived to carve out an autonomous niche in the social fabric of Bengal, where the distinction of caste was obliterated but that none from the Hindu bhadralok community did identify themselves with those sects, they were branded as exotic and subsequently came to be rejected by other sections of the society. In the 1870s, the Chandals of Bakarganj and Faridpur started a boycott of caste Hindus, (apart from Brahmins), as a form of social-protest, when their higher caste neighbors refused to accept an invitation to dine from a Chandal headman.
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A new elite arose from the Sephardic Jews and the "can-do" of Menahem Begin. In this context, the "myth" of Latrun derived from the frustrations and the death of the new immigrants and was catalysed by their integration in a society where "the survivor of Shoah carried the new collective memory, immigrant refugees who had troubled pasts, and then were confronted with hostility and threat and still took their place with their blood and taking part in the war". This myth was founded in the factual knowledge of the immigrants' participation in the battles, and the mythical knowledge because of the differences in the number of victims, the leaving of the injured on the fields of battle, and that the Latrun battle was the hardest and most important in the war. The influence on written history appeared primarily in books and commentary, where "the immigrants wanted only to make sure that their contribution at the battle was written in the collective memory with a plus sign".
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The metabolism of the tobacco smoke procarcinogen benzo[a]pyrene involves three distinct steps - the introduction of an epoxide group in the 7,8-position, its hydration to a vicinal diol and the introduction of an epoxide in the 9,10-position. In the first step, a cytochrome P450 1A1 (CYP1A1) catalysed oxidation produces several products including (+)-benzo[a]pyrene-7,8-epoxide. The enzyme epoxide hydrolase, then hydrates the epoxide ring to yield the vicinal diol (−)-benzo[a]pyrene-7,8-dihydrodiol, which is then oxidised by cytochrome P450 oxidase again forming the mutagen and carcinogen (+)-benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide. This diol epoxide covalently binds to DNA by a ring-opening to alkylate the nucleobase forming a distorted structure, as shown at right, with intercalation of a pyrene polycyclic aromatic hydrocarbon moiety between the base pairs favouring π-stacking; these distortions have been confirmed by X-ray crystallographic and nuclear magnetic resonance structure studies.
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1987-89 Volkswagen Golf II 5-door (France) The Golf Mk2 was available as a 3- and 5-door hatchback. The 2-door and 4-door sedan variants of the Golf Mk2 were marketed under the Volkswagen Jetta name. No cabriolet version was developed from the Mk2; instead, the Mk1-based convertible continued to be produced, with minor changes. Trim levels included base, C, CL and GL and initially a range-topping Carat model (until 1986), later a GT (in 1987) version was also on offer. In North America, there was only a base model until 1986, in 1987 a GL and GT model, in 1988–1989, there were all three, and in 1990 until the end of its run there was again only a GL. The GTI model existed from 1985–1987, and again from 1990–1992, and the GTI 16v existed from 1987–1992. In Japan the range consisted of catalysed Ci/CLi/GLi models all sharing the same 1.6 or later 1.8 liter fuel-injected inline-four engines.
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This metabolite has several physiological consequences: the ability to influence intracellular signalling, adenohypophyseal hormone secretion, radical and quinone formation, and inhibition of tumor formation. Weak carcinogenic activity has been shown, likely due to radical formation and induction of single-strand DNA breaks. Inactivation of 2-OHE2 is catalysed by catechol-O-methyltransferase (COMT), with COMT exhibiting a faster rate for the methylation of 2-OHE2 versus 4-OH-E2. COMT, a blood-borne enzyme, mediates the most common form of 2- or 4-hydroxyestradiol inactivation, in addition to glucuronidation and sulfation. However, this inactivation can allow for the accumulation of 4-OHE2, as 2-OHE2 inhibits 4-OHE2 methylation by COMT, but 4-OHE2 does not inhibit 2-OH-E2 methylation in return. Antitumor activity of 2-meOE2 is thought to be mediated by antiproliferative and antimetastatic effects. Inhibition of cellular proliferation and metastasis appears to be via induction of caspase-8, followed by caspase-3 and eventually DNA fragmentation. Induction of apoptosis by 2-meOE2 may be p53 dependent or independent.
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D-amino acid + H2O + acceptor <=> a 2-oxo acid + NH3 \+ reduced acceptor This reaction is distinct from the oxidation reaction catalysed by D-amino acid oxidase that uses oxygen as a second substrate, as the dehydrogenase can use many different compounds as electron acceptors, with the physiological substrate being coenzyme Q. D-amino acid dehydrogenase is an enzyme that catalyzes NADPH from NADP+ and D- glucose to produce D- amino acids and glucose dehydrogenase. Some but not limited to these amino acids are D-leucine, D-isoleucine, and D-Valine, which are essential amino acids that humans cannot synthesize due to the fact that they are not included in their diet. Moreover, D- amino acids catalyzes the formation of 2-oxo acids to produce D- amino acids in the presence of DCIP which is an electron acceptor. D-amino acids are used as components of pharmaceutical products, such as antibiotics, anticoagulants, and pesticides, because they have been shown to be not only more potent than their L enantiomers, but also more resistant to enzyme degradation.
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Having catalysed the support to the plight of the Mediterranean pinniped by the Prince Albert II of Monaco Foundation, Tethys joined efforts with WWF Greece in a long-term project, CYCLADES LIFE+, co-financed by the European Commission, the Prince Albert II of Monaco Foundation, the BlueMarine Foundation, and the Ensemble Foundation. The project envisages the involvement of the local communities of the islands of Syros and Andros (Greece) in the co-management and participation in the protection of the local marine biodiversity, particularly on and around the uninhabited island of Gyaros, which hosts the Mediterranean's largest surviving colony of monk seals, as well as important colonies of threatened marine birds. Tethys' expertise has also contributed to the formulation of a national strategy and action plan for the conservation of the Mediterranean monk seal in Greece,Notarbartolo di Sciara G., Adamantopoulou S., Androukaki E., Dendrinos P., Karamanlidis A.A., Paravas V., Kotomatas S. 2009. National strategy and action plan for the conservation of the Mediterranean monk seal in Greece, 2009 - 2015.
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The neutral superbase P4-t-Bu is superior to ionic bases if those are sensitive to oxidation or side reactions (such as acylation) when they cause solubility problems or Lewis acid catalysed side reactions (such as aldol reactions, epoxy ring opening etc). The dehydrohalogenation of n-alkyl bromides yields the alkene, such as the reaction 1-bromooctane with P4-t-Bu which yields 1-octene almost quantitatively (96%) under mild conditions, compared to the potassium tert-butoxide/18-crown-6 system with only 75% yield. Alkylations on weakly acidic methylene groups (e.g. in the case of carboxylic esters or nitriles) proceed with high yield and selectivity. For example, by the reaction of 8-phenylmenthylphenylacetate with iodoethane in the presence of P4-t-Bu only the monoethyl derivative in the Z configuration is obtained in 95% yield. : Monoethylierung von 8-Phenylmenthyl-phenylacetat Succinonitrile reacts with iodoethane in the presence of P4-t-Bu in 98% yield to give the tetraethyl derivative without undergoing a Thorpe-Ziegler reaction to form a cyclic α-ketonitrile.
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In the reaction mechanism for this organic reaction the base abstracts the acidic α-proton of the peroxide 1 to form the carbanion 4 as a reactive intermediate which rearranges to the ketone 2 with expulsion of the hydroxyl anion 3'. This intermediate gains a proton forming the alcohol 3. :Kornblum-DeLaMare rearrangement Mechanism Deprotonation and rearrangement can also be a concerted reaction without formation of 4. An alternative reaction mechanism involving direct nucleophilic displacement on the peroxide link of the amine followed by an elimination reaction is considered unlikely based on the outcome of this model reaction:The mechanism of the tertiary amine catalysed isomerisation of endoperoxides to hydroxyketones: synthesis and chemistry of the intermediate postulated in the peroxide attack mechanism David R. Kelly, Harjinder Bansal and J. J. Gwynfor Morgan Tetrahedron Letters Volume 43, Issue 51 , 16 December 2002, Pages 9331–9333 :Kornblum-DeLaMare rearrangement alternative mechanism The peroxide 1 converts to the hydroxyketone 2 by action of triethylamine but the alternative route through hydroxylamine 3 by nucleophilic displacement with Lithium diisopropylamide and the ammonium salt 4 (by methylation with methyl trifluoromethanesulfonate) fails.
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'Methods of pH homeostasis and energy generation in acidophiles' (with reference to Baker-Austin & Dopson, 2007 and Apel, Dugan, & Tuttle, 1980): (1) Direction of transmembrane electrochemical gradient (pH) and blocking of H+ by the cell membrane; (2) Reversed membrane potential through potassium transport, a modification towards maintaining a stable Donnan potential; (3) Secondary transporter protein; the H+ and Na+ gradient is harnessed to drive transport of nutrients and solutes; (4) Proton pump actively removes H+, balancing the energy gained from the H+ entry to the cytoplasm. (5) Vesicles containing protons avoid acidification of the cytoplasm, but still generate ATP from the electrochemical gradient (in A.ferrooxidans); (6) Uncouplers (uncharged compounds), such as organic acids, permeate the membrane and release their H+, leading to acidification of the cytoplasm; (7) To avoid this, heterotrophic acidophiles may degrade the uncouplers; (8) Alternatively, cytoplasmic enzymes or chemicals may bind or sequester the protons. The outflow of acidic liquids and other pollutants from mines is often catalysed by acid-loving microorganisms; these are the acidophiles in acid mine drainage. Acidophiles are not just present in exotic environments such as Yellowstone National Park or deep-sea hydrothermal vents.
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His thought has been recognized as a precursor of Heidegger in philosophy, of Wittgenstein in the critique of language, of Derrida in hermeneutics. There are three phases in the development of his philosophy. Between 1905 and 1907 – his university years – Michelstaedter’s thought was characterized by a decadent, “Dannunzian” influence, albeit with constant attention to the relationship between the individual and society, to everything social that impedes the individual’s expression of singularity. From late 1907 through 1908, Michelstaedter made a key contribution in Europe to the study of the tragic as a possible means of salvaging an immanent meaning, a resistant centre to the “crisis of the foundations” that had transformed existence. In 1908 Michelstaedter added his voice to those of Henrik Ibsen, Otto Weininger, Scipio Slataper, and Giovanni Amendola in Italy, who would turn to “tragic thought” as a response to the abyss opened by nihilism. In 1909, catalysed by the task of writing a university thesis on the concepts of persuasion and rhetoric in the works of Plato and Aristotle, Michelstaedter’s thought underwent a shift – one that would continue after he returned to Gorizia.
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The Hajos 1974 carbinolamine mechanism has had an unwitting support in a more recent paper by Michael Limbach.β-Homoamino acids as catalysts on enantioselective intra- and intermoelcular aldol reactions by Michael Limbach, Tetrahedron Letters 47 (2006) 3843-3847 The triketone starting material 2- methyl-2-(3-oxobutyl)-1,3-cyclopentanedione gave the expected optically active bicyclic ketol (+)-(3aS,7aS)-3a,4,7,7a-tetrahydro-3a-hydroxy-7a-methyl-1,5(6H)-indanedione with (S)-(−)-proline catalyst. On the other hand, the stereochemical outcome is reversed with ee selectivities of up to 83% by using the homologue amino acid catalysts, such as (S)-β-homoproline, [(pyrrolidine-(2S)-yl) acetic acid]. The virtual anomaly can be explained with a top side approach of the bulkier beta amino acids to the above triketone starting material of reflective symmetry. The top side approach results in the formation of an enantiotopic carbinolamine to give the (−)-(3aR,7aR)-3a,4,7,7a-tetrahydro-3a-hydroxy-7a-methyl-1,5(6H)-indanedione bicyclic ketol enantiomer identical to the one obtained with unnatural (R)-(+)-proline. List in 2010 on the other hand is perplexed and surprised that Hajos rejected the enamine mechanism, certainly in light of earlier work by Spencer in 1965 on amine catalysed aldol reactions.
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