"It has never been observed in any solid phase of hydrogen," he said.
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For most substances in the universe, the solid phase is denser than the liquid phase.
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This latest work isn't a true solid phase of metallic hydrogen, either, but it's one more promising step forward.
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But this fluid phase of metallic hydrogen is still very different from the long-sought solid phase, according to William Nellis, who led those earlier experiments.
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Dr. Hosono's team wondered what would have happened if Theia had crashed into Earth at that time, rather than during a later, cooler, more solid phase.
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" Musk said the explosion's cause "basically involves a combination of liquid helium, advanced carbon fiber composites, and solid oxygen, oxygen so cold it actually enters solid phase.
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Dr Price suspects that in his experiment the surface of the inner cylinder is taking on the role played in a thunderhead by water's solid phase, ice.
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Now a team of Scottish physicists fro the University of Edinburgh think they may have spotted a new phase that may be the precursor to a true solid phase of metallic hydrogen.
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Apart from the coolness factor, a truly solid phase of metallic hydrogen would be useful for all kinds of applications—assuming it could be "quenched to ambient pressure and temperature," Nellis told Gizmodo via email.
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Noncovalent solid-phase organic synthesis or NC-SPOS is a form of Solid-phase synthesis whereby the organic substrate is bonded to the solid phase not by a covalent bond but by other chemical interactions. This bond may consist of an induced dipole interaction between a hydrophobic matrix and a hydrophobic anchor. As long as the reaction medium is hydrophilic (polar) in nature the anchor will remain on the solid phase. Switching to a nonpolar solvent releases the organic substrate containing the anchor.
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Large scale custom peptide synthesis can be carried out either in a liquid solution or in solid phase. In general, peptides shorter than 8 amino acids are prepared more economically by solution chemistry. Peptides larger than 8 residues are generally assembled by solid phase chemistry. Solid phase peptide synthesis (SPPS) can be carried out either manually or in a fully automated fashion.
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In the past, oligonucleotide synthesis was carried out manually in solution or on solid phase. The solid phase synthesis was implemented using, as containers for the solid phase, miniature glass columns similar in their shape to low-pressure chromatography columns or syringes equipped with porous filters. Currently, solid-phase oligonucleotide synthesis is carried out automatically using computer-controlled instruments (oligonucleotide synthesizers) and is technically implemented in column, multi-well plate, and array formats. The column format is best suited for research and large scale applications where a high-throughput is not required.
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SPPS has been expanded to include solid phase synthesis of nucleotides and saccharides.
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This technique for growing crystals from the melt (liquid/solid phase transition) is used in materials research.
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Silica in a spin column with water and with DNA sample in chaotropic buffer Spin column-based nucleic acid purification is a solid phase extraction method to quickly purify nucleic acids. This method relies on the fact that nucleic acid will bind to the solid phase of silica under certain conditions.
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Relatively short fragments of DNA, RNA, and modified oligonucleotides are also synthesised by the solid-phase method. Although oligonucleotides can be synthesised in a flask, they are almost always synthesised on solid phase using a DNA/RNA synthesizer. For a more comprehensive review, see oligonucleotide synthesis. The method of choice is generally phosphoramidite chemistry, developed in the 1980s.
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One of the most common variations of the Nenitzescu reaction is the solid phase variant. This reaction, first reported by Ketcha et al., is shown below. Description of the solid-phase Nenitzescu indole synthesis It takes place on a highly cross- linked ArgoPore®-Rink-NH-Fmoc resin and functions with a variety of substituents on both reactants.
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In one solid-phase synthesis application, the amine is covalently attached to Wang resin."The Solid-Phase Zincke Reaction: Preparation of -Hydroxy Pyridinium Salts in the Search for CFTR Activation" Eda, M.; Kurth, M. J.; Nantz, M. H. J. Org. Chem. 2000, 65(17), 5131 - 5135. () The Zincke reaction Another example is the synthesis of a chiral isoquinolinium salt.
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As the leuco form is more stable in lower temperatures and solid phase, the records on thermochromic papers slowly fade out over years.
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SPORE (Solid Phase Organic Reactions) was a database for synthetic pathways via polymer- bound organic compounds, with extensive data on each individual reaction.
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Solid-phase microextraction sampling Solid phase microextraction, or SPME, is a solid phase extraction sampling technique that involves the use of a fiber coated with an extracting phase, that can be a liquid (polymer) or a solid (sorbent), which extracts different kinds of analytes (including both volatile and non-volatile) from different kinds of media, that can be in liquid or gas phase. The quantity of analyte extracted by the fibre is proportional to its concentration in the sample as long as equilibrium is reached or, in case of short time pre-equilibrium, with help of convection or agitation.
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There are several mechanisms flame retardants use to prevent fire, however the most effective ones are the gas phase and the solid phase reactions. In the solid phase halogenated flame retardants produce char layer on burnig materials suffocating the combustion, as well as in the gas phase they remove H+ and OH- rdicals from the flammable gasses, by reaction with the Br and Cl atoms to further slowdown the burining process. Non-halogenated OPEs are effective mainly in the solid phase of burning materials. Upon exposure to heat the phosphorus compounds react to form a polymeric form of phosphorous acid.
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See Vapor–liquid equilibrium for more information. In addition to the above-mentioned types of phase diagrams, there are thousands of other possible combinations. Some of the major features of phase diagrams include congruent points, where a solid phase transforms directly into a liquid. There is also the peritectoid, a point where two solid phases combine into one solid phase during cooling.
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The efficiency to which the antigen binds to the solid phase is dependent on temperature, length of exposure as well as concentration. Solid phases used include nitrocellulose membranes, paper, glass, agarose and polystyrene or polyvinylchloride microtiter plates. Microtiter plates are the most widely used solid phase because they are easy to handle, allow for automation and for analysis using microtiter plate readers.
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One property of a lipid bilayer is the relative mobility (fluidity) of the individual lipid molecules and how this mobility changes with temperature. This response is known as the phase behavior of the bilayer. Broadly, at a given temperature a lipid bilayer can exist in either a liquid or a solid phase. The solid phase is commonly referred to as a “gel” phase.
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170pxBatch chromatography Binding to the solid phase may be achieved by column chromatography whereby the solid medium is packed onto a column, the initial mixture run through the column to allow settling, a wash buffer run through the column and the elution buffer subsequently applied to the column and collected. These steps are usually done at ambient pressure. Alternatively, binding may be achieved using a batch treatment, for example, by adding the initial mixture to the solid phase in a vessel, mixing, separating the solid phase, removing the liquid phase, washing, re-centrifuging, adding the elution buffer, re-centrifuging and removing the elute. Sometimes a hybrid method is employed such that the binding is done by the batch method, but the solid phase with the target molecule bound is packed onto a column and washing and elution are done on the column.
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When small quantities of solid sorbents are used to absorb the target for concentration, this method is referred to as solid-phase microextraction.Addleman, R. S.; Egorov, O. B.; O'Hara, M.; Zemaninan, T. S.; Fryxell, G.; Kuenzi, D. (2005). Nanostructured sorbents for solid phase microextraction and environmental assay. In: Karn, B.; Masciangioli, T.; Zhang, W.; Colvin, V.; Alivisatos, P. (eds.), Nanotechnology and the Environment: Applications and Implications.
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Analytical Chemistry 2000, 73 (3), 708-714. This is an alternative method to solid-phase extraction methods and protein precipitation, which has the advantage of being more reproducible and robotic assistance has made LLE comparable in speed to solid phase extraction. The robotics used for LLE can perform an entire extraction with quantities in the microliter scale and performing the extraction in as little as ten minutes.
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Cranberry glass is made in craft production rather than in large quantities, due to the high cost of the gold. The gold chloride is made by dissolving gold in a solution of nitric acid and hydrochloric acid (aqua regia). The glass is typically hand blown or molded. The finished, hardened glass is a type of colloid, a solid phase (gold) dispersed inside another solid phase (glass).
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Solid-phase analytes are ionized with matrix-assisted laser desorption ionization (MALDI) for large mass molecules or laser desorption ionization (LDI) for molecules with smaller masses.
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A typical solid phase extraction manifold. The cartridges drip into the chamber below, where tubes collect the effluent. A vacuum port with gauge is used to control the vacuum applied to the chamber. Solid-phase extraction (SPE) is an extractive technique by which compounds that are dissolved or suspended in a liquid mixture are separated from other compounds in the mixture according to their physical and chemical properties.
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A selection of solid phase extraction cartridges, available in many sizes, shapes, and types of stationary phase. A typical solid phase extraction involves five basic steps. First, the cartridge is equilibrated with a non-polar or slightly polar solvent, which wets the surface and penetrates the bonded phase. Then water, or buffer of the same composition as the sample, is typically washed through the column to wet the silica surface.
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Bacteria biooxidation is an oxidation process caused by microbes where the valuable metal remains (but becomes enriched) in the solid phase. In this process, the metal remains in the solid phase and the liquid can be discarded. Bacterial oxidation is a biohydrometallurgical process developed for pre- cyanidation treatment of refractory gold ores or concentrates. The bacterial culture is a mixed culture of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans.
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Solid-phase assays (sometimes called the "antigen capture" method) use reagent antigens or antibodies affixed to a surface (usually a microplate). Microplate wells coated with anti-A, -B and -D reagents are used for forward grouping. The test sample is added and the microplate is centrifuged; in a positive reaction, the red blood cells adhere to the surface of the well. Some automated analyzers use solid phase assays for blood typing.
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QuEChERS is a solid phase extraction method for detection of pesticide residues in food. The name is a portmanteau word formed from "quick, easy, cheap, effective, rugged, and safe".
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The density of ice Ih is 0.917 g/cm3 which is less than that of liquid water. This is attributed to the presence of hydrogen bonds which causes atoms to become more distant in the solid phase. Because of this, ice Ih floats on water, which is highly unusual when compared to other materials. The solid phase of materials is usually more closely and neatly packed and has a higher density than the liquid phase.
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After sufficient oxidation, the vapor pressure is sufficiently low that the gas-phase compound partitions into the solid-phase, producing secondary organic matter (the particle phase of secondary organic aerosol). SOAs represent a significant proportion of aerosols contained in the troposphere. A common misconception is that the aerosol refers to the solid phase of the compound, where in reality, by definition, it is the combination of the gas- and solid-phases which constitute the aerosol.
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The reagents are aryl selenenyl bromides, and they were first developed for solution phase chemistry and then modified for solid phase bead attachment via an aryloxy moiety. The solid-phase reagents were applied toward the selenenylation of various alkenes with good enantioselectivities. The products can be cleaved from the solid support using organotin hydride reducing agents. Solid-supported reagents offers advantages over solution phase chemistry due to the ease of workup and purification.
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Compared to the Basic Test it is more sensitive to operator technique, and as a result may be less precise. _Acute Toxicity Solid-Phase Test_ is a procedure that allows the test organism to come in direct contact with the solid sample as particulate in an aqueous suspension. Normally, this test provides results indicating equal or higher toxicity when compared to eluate or pore water tests of the same sample.Microtox Acute Toxicity Solid-Phase Test.
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They also documented the formation of solid phase polymeric silicon hydrides .J. W. Mellor, "A Comprehensive Treatise on Inorganic and Theoretical Chemistry," Vol. VI, Longman, Green and Co. (1947) pp.
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Robert Bruce Merrifield (July 15, 1921 – May 14, 2006) was an American biochemist who won the Nobel Prize in Chemistry in 1984 for the invention of solid phase peptide synthesis.
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Some separation methods that can be used to identify unapproved dyes include the solid phase extraction process, the overpressured thin layer chromatography process, and the use of reversed-phase plates.
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Brassicasterol has a low water solubility and, as a consequence, a high octanol-water partition coefficient. This means that, in most environmental systems, brassicasterol will be associated with the solid phase.
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In between the washes, only the ligand and its specific binding counterparts remain specifically bound or "immunosorbed" by antigen-antibody interactions to the solid phase, while the nonspecific or unbound components are washed away. Unlike other spectrophotometric wet lab assay formats where the same reaction well (e.g., a cuvette) can be reused after washing, the ELISA plates have the reaction products immunosorbed on the solid phase, which is part of the plate, and so are not easily reusable.
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400px 400px Most CPP-nucleic acid complexes that have been proposed so far are formed through covalent bonding. A range of CPP-nucleic acid complexes have been synthesized through different chemistries that are either stable or cleavable linkages. And the most widely used method in publication is cleavable disulfide linkages through total stepwise solid- phase synthesis or solution-phase or solid-phase fragment coupling. Some other strategies like stable amide, thiazolidine, oxime and hydrazine linkage have also been developed.
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Serine (Oxa), Threonine [Oxa(5-Me)], and Cysteine (THz) Derived Pseudoprolines. Pseudoproline (also pseudo-proline, ψ-Pro) derivatives are artificially created dipeptides to minimize aggregation during Fmoc solid- phase synthesis of peptides.
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The basic mechanisms of flame retardancy vary depending on the specific flame retardant and the substrate. Additive and reactive flame-retardant chemicals can both function in the vapor (gaseous) or condensed (solid) phase.
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The solid phase particles are placed in a column where liquid phase is pumped in from the bottom and exits at the top. The gravity of the particles ensure that the solid phase does not exit the column with the liquid phase. Affinity columns can be eluted by changing salt concentrations, pH, pI, charge and ionic strength directly or through a gradient to resolve the particles of interest. More recently, setups employing more than one column in series have been developed.
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A stationary phase of polar functionally bonded silicas with short carbons chains frequently makes up the solid phase. This stationary phase will adsorb polar molecules which can be collected with a more polar solvent.
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5β-coprostanol has a low water solubility, and consequently a high octanol-water partition coefficient (log Kow = 8.82). This means that in most environmental systems, 5β-coprostanol will be associated with the solid phase.
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Depending on the morphology of the reactants, it is possible to initiate a SHS reaction where a liquid phase occurs prior to phase formation or to directly result in solid-phase products without any melt.
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The selecting of filter press type depends on the value of liquid phase or the solid phase. If extracting liquid phase is desired, then filter press is among the most appropriate methods to be used.
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J. Radioanal. Nucl. Chem. 2012 Vol 293 pp309-312.Rahman, I. et al Determination of lead in solution by solid phase extraction, elution, and spectrophotometric detection using 4-(2-Pyridylazo)-resorcinol. Cent. Eur. J. Chem.
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Few standards are available or being prepared for sensory analysis of flavors.e.g. ISO 13301:2002 Sensory analysis – Methodology – General guidance for measuring odor, flavor and taste detection thresholds by a three-alternative forced-choice (3-AFC) procedure, or ISO 6564:1985 Sensory analysis – Methodology – Flavor profile methods. In chemical analysis of flavors, solid phase extraction, solid phase microextraction, and headspace gas chromatography are applied to extract and separate the flavor compounds in the sample. The determination is typically done by various mass spectrometric techniques.
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They later developed solid supports that have facilitated the merger of solid phase peptide- and peptide- organic chemistry with solid phase chemical biology and protein chemistry. More recently Meldal has developed an optical encoding technique and has been focused on the merger of organic chemistry and peptide chemistry on solid support. He has devised a range of novel methods on the generation of N-acyl iminium ions which combinatorial libraries of these compounds have generated and screened for active GPCR substances in cell-based on-bead screening.
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Gold–aluminium phase diagram Peritectic transformations are also similar to eutectic reactions. Here, a liquid and solid phase of fixed proportions react at a fixed temperature to yield a single solid phase. Since the solid product forms at the interface between the two reactants, it can form a diffusion barrier and generally causes such reactions to proceed much more slowly than eutectic or eutectoid transformations. Because of this, when a peritectic composition solidifies it does not show the lamellar structure that is found with eutectic solidification.
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CPC Scientific manufactures most of their products by way of solid-phase peptide synthesis, a process originally described by Robert Bruce Merrifield in 1963. Solid-phase synthesis routes enable manufacturing of relatively long peptide sequences by avoiding isolation and purification of synthetic intermediates. This iterative process allows for the preparation of more complex peptides for use as active pharmaceutical ingredients (APIs), novel drug therapeutics, and general research applications. CPC Scientific has published some research articles that describe peptide synthesis methodologies, including a technique called hydrocarbon stapling.
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PyBOP (benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate) is a peptide coupling reagent used in solid phase peptide synthesis. It is used as a substitute for the BOP reagent - avoiding the formation of the carcinogenic waste product HMPA.
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Boom method (aka Boom nucleic acid extraction method) is a solid phase extraction method for isolating nucleic acid from a biological sample. This method is characterized by "absorbing the nucleic acids (NA) to the silica beads".
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Due to radioactive nucleotides have similar properties to their stable, inactive, counterparts similar analytical chemistry separation techniques can be used. These separation methods include precipitation, Ion Exchange, Liquid Liquid extraction, Solid Phase extraction, Distillation, and Electrodeposition.
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2013 Vol 11 pp672-678.Rahman, I. et al Selective separation of tri- and pentavalent arsenic in aqueous matrix with a macrocycle-immobilized solid-phase extraction system. Water, Air, & Soil Pollution. 2013 Vol 224 pp.1–11.
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The benzyl ester can be removed by hydrogenolysis, the fluorenylmethylenoxy group (Fmoc) by bases (such as piperidine), and the phenolic tert-butyl ether cleaved with acids (e.g. with trifluoroacetic acid). A common example for this application, the Fmoc-peptide synthesis, in which peptides are grown in solution and on solid phase is very important. The protecting groups in solid-phase synthesis with regard to the reaction conditions such as reaction time, temperature and reagents can be standardized so that they are carried out by a machine, while yields of well over 99% can be achieved.
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Solid-phase microextraction (SPME), is a solid phase extraction technique that involves the use of a fiber coated with an extracting phase, that can be a liquid (polymer) or a solid (sorbent), which extracts different kinds of analytes (including both volatile and non- volatile) from different kinds of media, that can be in liquid or gas phase. The quantity of analyte extracted by the fibre is proportional to its concentration in the sample as long as equilibrium is reached or, in case of short time pre-equilibrium, with help of convection or agitation.
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Off-resin cyclization is a solid-phase synthesis of key intermediates, followed by the key cyclization in solution phase, the final deprotection of any masked side chains is also carried out in solution phase. This has the disadvantages that the efficiencies of solid-phase synthesis are lost in the solution phase steps, that purification from by-products, reagents and unconverted material is required, and that undesired oligomers can be formed if macrocycle formation is involved. The use of pentafluorophenyl esters (FDPP, PFPOH) and BOP-Cl are useful for cyclising peptides.
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Latent heat storage can be achieved through changes in the State of matter from liquid→solid, solid→liquid, solid→gas and liquid→gas. However, only solid→liquid and liquid→solid phase changes are practical for PCMs. Although liquid–gas transitions have a higher heat of transformation than solid–liquid transitions, liquid→gas phase changes are impractical for thermal storage because large volumes or high pressures are required to store the materials in their gas phase. Solid–solid phase changes are typically very slow and have a relatively low heat of transformation.
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The principle of solid phase DNA sequencing was described in 1989 based on binding of biotinylated DNA to streptavidin coated magnetic beads and elution of one DNA strands selectively using alkali. The method allowed robotic applications suitable for clinical sequencing, but the magnetic handling has also found frequent use in many molecular applications, including sample handling for DNA diagnostics. The use of solid phase methods for DNA handling is now frequently used as an integrated part of many of the next generation DNA sequencing methods, as well as numerous molecular diagnostics applications.
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There are five major Microtox tests including the Basic Test, the 100% Test, the Solid Phase Test, the Comparison Test, and the Inhibition Test. Of these five tests, three are used for sediment and soil testing including the Basic Test, the 100% Test and the Solid-Phase Test. All of these versions follow the same general method of reconstituting the Allivibrio fischeri reagent in the Reconstitution Solution. Corrections are made for salinity and particulate matter, then the bacteria are exposed to the sample solution depending on the methods of the particular test.
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The formed imines were then derivatized to generate 4-thiazolidinones, B-lactams, and pyrrolidines. The use of solid- phase supports greatly simplifies the synthesis of large combinatorial libraries of compounds. This is done by anchoring a starting material to a solid support and then running subsequent reactions until a sufficiently large library is built, after which the products are cleaved from the support. The use of solid-phase purification has also been demonstrated for use in solution-phase synthesis schemes in conjunction with standard liquid-liquid extraction purification techniques.
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Because of the varying pressure at depth, models of a water world include "steam, liquid, superfluid, high- pressure ices, and plasma phases" of water. Some of the solid-phase water could be in the form of ice VII.
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Formation and examples of nuclear membraneless compartments Stress granule dynamics Many examples of biomolecular condensates have been characterized in the cytoplasm and the nucleus that are thought to arise by either liquid- liquid or liquid-solid phase separation.
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As already noted the local fauna of cockles can be stained with relation to their habitat. Glauconite is an iron- and potassium-rich mineral and the solid phase reactions can produce the iron- and potassium-rich dye Prussian blue.
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The scale of this technique can be an advantage for creating libraries for screening by using less amounts of glycoamino acids per peptide. However to produce larger quantities of glycopeptides traditional resin-based solid phase techniques would be better.
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The chlorine atoms are in a tetrahedral arrangement around the central zirconium. In the solid phase, Zr(ClO4)4 crystals are monoclinic with a=12.899, b=13.188, c=7.937 Å, β=107.91°. There are four molecules per unit cell.
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Te coordination Tellurium tetrafluoride melts at 130 °C and decomposes to tellurium hexafluoride at 194 °C. In the solid phase it consists of infinite chains of TeF3F2/2 in an octahedral geometry. A lone pair of electrons occupies the sixth position.
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Such problems can be intermittent as the powdered particles of tin move around. Tin pest can be avoided by alloying with small amounts of electropositive metals or semimetals soluble in tin's solid phase, e.g. antimony or bismuth, which prevent the decomposition.
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Kristy read her Doctor of Philosophy degree with Prof. David J. Procter on Solid-phase approaches to heterocycles using a sulfur linker cleaved by reduction with samarium (II) iodide at University of Glasgow and successfully gained her PhD in 2006.
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The rare- earth elements patterns observed in igneous rocks are primarily a function of the chemistry of the source where the rock came from, as well as the fractionation history the rock has undergone. Fractionation is in turn a function of the partition coefficients of each element. Partition coefficients are responsible for the fractionation of a trace elements (including rare- earth elements) into the liquid phase (the melt/magma) into the solid phase (the mineral). If an element preferentially remains in the solid phase it is termed ‘compatible’, and it preferentially partitions into the melt phase it is described as ‘incompatible’.
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Analytical laboratories use solid phase extraction to concentrate and purify samples for analysis. Solid phase extraction can be used to isolate analytes of interest from a wide variety of matrices, including urine, blood, water, beverages, soil, and animal tissue. SPE uses the affinity of solutes dissolved or suspended in a liquid (known as the mobile phase) for a solid through which the sample is passed (known as the stationary phase) to separate a mixture into desired and undesired components. The result is that either the desired analytes of interest or undesired impurities in the sample are retained on the stationary phase.
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The dynamics of hydrogen bond structures in water can be probed by the IR spectrum of OH stretching vibration. In the hydrogen bonding network in protic organic ionic plastic crystals (POIPCs), which are a type of phase change material exhibiting solid-solid phase transitions prior to melting, variable-temperature infrared spectroscopy can reveal the temperature dependence of hydrogen bonds and the dynamics of both the anions and the cations. The sudden weakening of hydrogen bonds during the solid-solid phase transition seems to be coupled with the onset of orientational or rotational disorder of the ions.
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At the institute, later Rockefeller University, he worked as an Assistant for Dr. D.W. Woolley on a dinucleotide growth factor he discovered in graduate school and on peptide growth factors that Woolley had discovered earlier. These studies led to the need for peptide synthesis and, eventually, to the idea for solid phase peptide synthesis (SPPS) in 1959. In 1963, he was sole author of a classic paper in the Journal of the American Chemical Society in which he reported a method he called "solid phase peptide synthesis". This article is the fifth most cited paper in the journal's history.
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Additionally, POLYINTELLPOLYINTELL, an expert in sample clean-up by Solid Phase Extraction designs, manufactures and markets AFFINIMIPSPE productslist of AFFINIMIPSPE molecularly imprinted polymer-based SPE products for instance for mycotoxins such as patulin, zearalenone, fumonisins, ochratoxin A, for endocrine disruptors (bisphenol A, estrogen derivatives etc...) or for the purification of radiotracers before their use in positron emission tomography (PET). Fast and cost-effective molecularly imprinted polymer technique has applications in many fields of chemistry, biology and engineering, particularly as an affinity material for sensors, detection of chemical, antimicrobial, and dye, residues in food, adsorbents for solid phase extraction, binding assays, artificial antibodies, chromatographic stationary phase, catalysis, drug development and screening, and byproduct removal in chemical reaction. Molecular imprinted polymers pose this wide range of capabilities in extraction through highly specific micro- cavity binding sites. Due to the specific binding site created in a MIP this technique is showing promise in analytical chemistry as a useful method for solid phase extraction.
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The following four subsections outline proposals which could explain the physical mechanism allowing deep focus earthquakes to occur. With the exception of solid-solid phase transitions, the proposed theories for the focal mechanism of deep earthquakes hold equal footing in current scientific literature.
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Epitaxial silicon is usually grown using vapor-phase epitaxy (VPE), a modification of chemical vapor deposition. Molecular-beam and liquid-phase epitaxy (MBE and LPE) are also used, mainly for compound semiconductors. Solid-phase epitaxy is used primarily for crystal-damage healing.
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The lipids were fractionated on a solid-phase extraction column and the neutral lipids, free fatty acids and other materials discarded and the phospholipid phase then dried, prior esterification to form the fatty acid methyl esters (FAMEs) to make them suitable for analysis.
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Izatt, R. et al Solid phase extraction of ions of analytical interest using molecular recognition technology. Am. Lab. 1994 Vol 26(18) pp28c-28m.Paučová, V. et al A Comparison of extraction chromatography TEVA Resin and MRT AnaLig TC-02 Methods for 99Tc Determination.
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For peptides three main types of methods are used, namely chemical synthesis, extraction from natural substances, and biosynthesis. Chemical synthesis is used for smaller peptides made of up to 30–40 amino acids. One distinguishes between “liquid phase” and “solid phase” synthesis.
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Friction stud welding is a solid phase welding process where the metals do not liquefy. This permits metal combinations such as welding aluminium studs to steel which would be problematic with arc welding because of the formation of brittle inter-metallic compounds.
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Dulanská, S. Pre-concentration and determination of 90Sr in radioactive wastes using solid phase extraction techniques. J. Radioanal. Nucl. Chem. 2011 Vol 288 pp705-708.Goken, G. et al Metal ion separations using superLig or anaLig materials encased in empore cartridges and disks. 1999.
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Technetium hexafluoride is a golden-yellow solid at room temperature. Its melting point is 37.4 °C and its boiling point is 55.3 °C. Technetium hexafluoride undergoes a solid phase transition at −4.54 °C. Above this temperature (measured at 10 °C), the solid structure is cubic.
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Solid-phase synthesis is a common technique for peptide synthesis. Usually, peptides are synthesised from the carbonyl group side (C-terminus) to amino group side (N-terminus) of the amino acid chain in the SPPS method, although peptides are biologically synthesised in the opposite direction in cells. In peptide synthesis, an amino-protected amino acid is bound to a solid phase material or resin (most commonly, low cross-linked polystyrene beads), forming a covalent bond between the carbonyl group and the resin, most often an amido or an ester bond. Then the amino group is deprotected and reacted with the carbonyl group of the next, N-protected, amino acid.
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A specialised group of PCMs that undergo a solid/solid phase transition with the associated absorption and release of large amounts of heat. These materials change their crystalline structure from one lattice configuration to another at a fixed and well- defined temperature, and the transformation can involve latent heats comparable to the most effective solid/liquid PCMs. Such materials are useful because, unlike solid/liquid PCMs, they do not require nucleation to prevent supercooling. Additionally, because it is a solid/solid phase change, there is no visible change in the appearance of the PCM, and there are no problems associated with handling liquids, e.g.
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Solid phase peptide synthesis Custom peptide synthesis is the commercial production of peptides for use in biochemistry, biology, biotechnology, pharmacology and molecular medicine. Custom peptide synthesis provides synthetic peptides as valuable tools to biomedical laboratories. Synthetic oligopeptides are used extensively in research for structure-function analysis (for example to study protein-protein interfaces), for the development of binding assays, the study of receptor agonist/antagonists or as immunogens for the production of specific antibodies. Generally, peptides are synthesized by coupling the carboxyl group or C-terminus of one amino acid to the amino group or N-terminus of another using automated solid phase peptide synthesis chemistries.
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Even if the sample is liquid (e.g., a measured small drop), the final detection step in "dry" analysis involves reading of a dried strip by methods such as reflectometry and does not need a reaction containment chamber to prevent spillover or mixing between samples. As a heterogenous assay, ELISA separates some component of the analytical reaction mixture by adsorbing certain components onto a solid phase which is physically immobilized. In ELISA, a liquid sample is added onto a stationary solid phase with special binding properties and is followed by multiple liquid reagents that are sequentially added, incubated, and washed, followed by some optical change (e.g.
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Cholesterol has the ability to eliminate the liquid to solid phase transition in phospholipids. Due to sphingomyelin transition temperature being within physiological temperature ranges, cholesterol can play a significant role in the phase of sphingomyelin. Sphingomyelin are also more prone to intermolecular hydrogen bonding than other phospholipids.
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83-88, Magnesium Technology, 2014 # As a solid-phase process, friction extrusion can be done at low temperature thereby retaining nanoscale second phases and particles present in precursor material. Enables fabrication of bulk nanocomposite materials. # Enables enhanced bulk properties, such as energy absorption in magnesium alloys.
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Margatoxin can be chemically synthesized using the solid phase synthesis technique. The compound gained by this technique was compared with the natural, purified margatoxin. Both compounds had the same physical and biological properties. The chemically synthesized margatoxin is now used to study the role of Kv1.3 channels.
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Semple, K. T., Morris, A. W. J., & Paton, G. I. 2003. Bioavailability of hydrophobic organic contaminants in soils: fundamental concepts and techniques for analysis. European journal of soil science, 54(4), 809-818. Ionic compounds, such as heavy metals, can be precipitated into the solid phase.
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Due to a discrete description of the solid phase, constitutive relations are omitted, and therefore, leads to a better understanding of the fundamentals. This was also concluded by Zhu 2007 et al. and Zhu 2008 et al. during a review on particulate flows modelled with the CCDM approach.
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1: Synthesis of a simple organic molecular wire Other organic molecular wires include carbon nanotubes and DNA. Carbon nanotubes can be synthesized via various nano-technological approaches. DNA can be prepared by either step-wise DNA synthesis on solid-phase or by DNA-polymerase-catalyzed replication inside cells.
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Morten P. Meldal (born 1954 in Denmark) is a Danish chemist. He is a professor of Chemistry at University of Copenhagen in Copenhagen, Denmark. He is best known for developing the CuAAC-click reaction.Tornøe, C.W. and Meldal, M., Peptidotriazoles: Copper(I)-catalyzed 1,3-dipolar cycloadditions on solid- phase.
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The annealing step used to recrystallize or heal silicon layers amorphized during ion implantation is also considered one type of Solid Phase Epitaxy. The Impurity segregation and redistribution at the growing crystal-amorphous layer interface during this process is used to incorporate low-solubility dopants in metals and Silicon.
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Phalloidin Synthetic Scheme The first total synthesis of phalloidin was achieved through a combination of solid phase and solution phase synthesis (Baosheng Liu and Jianheng Zhang, United States Patent, US 8,569,452 B2). The physical and chemical properties of the synthetic phalloidin are the same as the naturally occurring phalloidin.
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SMA is a copolymer with maleic anhydride. Styrene can be copolymerized with other monomers; for example, divinylbenzene can be used for cross-linking the polystyrene chains to give the polymer used in solid phase peptide synthesis. Styrene-acrylonitrile resin (SAN) has a greater thermal resistance than pure styrene.
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Oxazoles have been found to be common substructures in multiple naturally isolated compounds and have thus garnered attention within the chemical and pharmaceutical community. The Robinson–Gabriel synthesis has been used during multiple studies dealing with molecules that incorporate an oxazole, among them Diazonamide A, Diazonamide B, bis-phosphine platinum (II) complexes, Mycalolide A, (−)-Muscoride A. Eric Biron et al. developed a solid- phase synthesis of 1,3-oxazole-based peptides on solid phase from dipeptides by oxidation of the side-chain followed by Wipf and Miller's cyclodehydration of β-ketoamides described above. Lilly Research Laboratories has disclosed the structure of a described dual PPARα/γ agonist that has possible beneficial impact on type 2 diabetes.
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In recent years, techniques for detection of HLA antibodies have become more sensitive with the introduction of solid- phase assays, including ELISA.Gebel HM, Bray RA, Nickerson P. Pre-transplant assessment of donor-reactive, HLA-specific antibodies in renal transplantation: contraindication vs. risk. Am J Transplant. 2003; 3(12):1488-500.
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Within solid phase peptide synthesis (SPPS) there exist two strategies for the synthesis of glycopeptides, linear and convergent assembly. Linear assembly relies on the synthesis of building blocks and then the use of SPPS to attach the building block together. An outline of this approach is illustrated below. Scheme 1.
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Such data is critical in determining the effect of alloy constituents in a bulk material, identification of solid-state reaction features, such as solid phase precipitates. Such information may not be amenable to analysis by other means (e.g. TEM) owing to the difficulty in generating a three-dimensional dataset with composition.
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The solid phase now bears a dipeptide. This cycle is repeated to form the desired peptide chain. After all reactions are complete, the synthesised peptide is cleaved from the bead. The protecting groups for the amino groups mostly used in the peptide synthesis are 9-fluorenylmethyloxycarbonyl group (Fmoc) and t-butyloxycarbonyl (Boc).
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The speed of sound in any chemical element in the fluid phase has one temperature-dependent value. In the solid phase, different types of sound wave may be propagated, each with its own speed: among these types of wave are longitudinal (as in fluids), transversal, and (along a surface or plate) extensional.
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Packaging air pillow made of PLA-blend bio-flex Biodegradation of any plastic is a process that happens at solid/liquid interface whereby the enzymes in the liquid phase depolymerize the solid phase Degli-Innocenti, Francesco. “Biodegradation of Plastics and Ecotoxicity Testing: When Should It Be Done.” Frontiers in Microbiology, vol. 5, no.
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Solid-phase epitaxy (SPE) is a transition between the amorphous and crystalline phases of a material. It is usually done by first depositing a film of amorphous material on a crystalline substrate. The substrate is then heated to crystallize the film. The single crystal substrate serves as a template for crystal growth.
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Gas chromatography (GC) is ideal to separate volatilized VOCs due to their low molecular weight. VOCs are carried by a gas vector (helium) through a chromatographic column (the solid phase) on which they have different affinities, which allows to separate them. Liquid chromatography may be used for liquid extractions of floral tissue.
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UCl6 is stable up to temperatures between 120 °C and 150 °C. The decomposition of UCl6 results in a solid phase transition from one crystal form of UCl6 to another more stable form. However, the decomposition of gaseous UCl6 produces UCl5. The activation energy for this reaction is about 40 kcal per mole.
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Evaluating TNA stability under simulated physiological conditions. Bioorg. Med. Chem. Lett. 26, 2418-2421, (2016). TNA oligonucleotides were first constructed by automated solid-phase synthesis using phosphoramidite chemistry. Methods for chemically synthesized TNA monomers (phosphoramidites and nucleoside triphosphates) have been heavily optimized to support synthetic biology projects aimed at advancing TNA research.
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The ancient wet manufacturing process of cement, consuming more energy (water evaporation) that the modern dry process, had the advantage to eliminate much of the soluble Na and K salts present in the raw material. As previously described in the two sections dealing respectively with ASR catalysis by alkali hydroxides and soda lime carbonation, soluble NaOH and KOH are continuously regenerated and released into solution when the soluble alkali silicate reacts with to precipitate insoluble calcium silicate. Therefore, portlandite is the main buffer of in the solid phase. As long as the stock of hydroxide in the solid phase is not exhausted, the alkali-silica reaction can continue to proceed until complete disparition of one of the reagents ( or ) involved in the pozzolanic reaction.
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The multi-anvil press is a type of device designed to produce extremely high pressures in a relatively small volume. This type of anvil press is used in materials science and geology for the synthesis and study of solid phase materials under extreme pressure, as well as for the industrial production of valuable minerals, especially synthetic diamonds. These instruments allow the simultaneous compression and heating of millimeter size solid phase samples such as rocks, minerals, ceramics, glasses, composite materials, or metal alloys and are capable of reaching pressures above 25 GPa and temperatures exceeding 2500 °C. This allows mineral physicists and petrologists studying the Earth’s interior to experimentally reproduce the conditions found throughout the lithosphere and upper mantle, to a depth of 700 km (citation, figure 1,2).
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In liquids, the cloud point is the temperature below which a transparent solution undergoes either a liquid-liquid phase separation to form an emulsion or a liquid-solid phase transition to form either a stable sol or a suspension that settles a precipitate. The cloud point is analogous to the 'dew point' at which a gas-liquid phase transition called condensation occurs in water vapour (humid air) to form liquid water (dew or clouds). When the temperature is below zero degrees Celsius, the dew point is called the frost point, as water vapour undergoes gas-solid phase transition called deposition, solidification, or freezing. In the petroleum industry, cloud point refers to the temperature below which wax in diesel or biowax in biodiesels forms a cloudy appearance.
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To eliminate the possibility of potential hydroxyl group interference, a novel method using silyl-aryl chemistry is used to link the molecules to the solid support which cleaves from the support and leaves no trace of the linker. Compounds that can be synthesized from solid-phase bound imines When anchoring a molecule to a solid support, intermediates cannot be isolated from one another without cleaving the molecule from the resin. Since many of the traditional characterization techniques used to track reaction progress and confirm product structure are solution-based, different techniques must be used. Gel- phase 13 C NMR spectroscopy, MALDI mass spectrometry, and IR spectroscopy have been used to confirm structure and monitor the progress of solid-phase reactions.
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Elizabeth Monroe is famous for having predicted in 1941, with John G. Kirkwood, in the Journal of Chemical Physics , that a system of hard spheres would undergo a liquid-solid phase transition. The original paper clearly states the seminal prediction "... that a system of hard spheres without attraction must crystallize at sufficiently small volumes".
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Thus the PSL changes into solid phase in a cold environment before water freezing can happen. While PSL impregnated textured surface behave as a traditional SLIPS in ambient conditions, when operated below the melting point of PSL, they resist PSL displacement out of surface texture by water, engendering enhanced icephobicity even on hydrophilic substrates.
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The formation of multiple native disulfides remains challenging of native peptide synthesis by solid-phase methods. Random chain combination typically results in several products with nonnative disulfide bonds. Stepwise formation of disulfide bonds is typically the preferred method, and performed with thiol protecting groups. Different thiol protecting groups provide multiple dimensions of orthogonal protection.
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It is an overlapping PCR method. It does not require a culture step because it sequences the whole viral genome directly from the clinical sample. Small oligonucleotides, complementary to the target, are used as probes for a hybridization reaction. The probes can be bound to a solid phase or to magnetic beads in liquid phase.
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Many substances dissolve congruently (i.e. the composition of the solid and the dissolved solute stoichiometrically match). However, some substances may dissolve incongruently, whereby the composition of the solute in solution does not match that of the solid. This solubilization is accompanied by alteration of the "primary solid" and possibly formation of a secondary solid phase.
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A typical phase diagram for a single-component material, exhibiting solid, liquid and gaseous phases. The solid green line shows the usual shape of the liquid–solid phase line. The dotted green line shows the anomalous behavior of water when the pressure increases. The triple point and the critical point are shown as red dots.
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AlH3 readily forms adducts with strong Lewis bases. For example, both 1:1 and 1:2 complexes form with trimethylamine. The 1:1 complex is tetrahedral in the gas phase, but in the solid phase it is dimeric with bridging hydrogen centres, (NMe3Al(μ-H))2. The 1:2 complex adopts a trigonal bipyramidal structure.
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These carbamate derivatives do not behave as amines, which allows certain subsequent transformations to occur that would be incompatible with the amine functional group. The Boc group can later be removed from the amine using moderately strong acids (e.g., trifluoroacetic acid). Thus, Boc serves as a protective group, for instance in solid phase peptide synthesis.
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Ian Hutton, pp. 62–63Determination of a/β Thujone and Related Terpenes in Absinthe using Solid Phase Extraction and Gas Chromatography. Retrieved 5 March 2006. Tests conducted on mice to study toxicity showed an oral of about 45 mg thujone per kg of body weight, which represents far more absinthe than could be realistically consumed.
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This gel is a bi-phasic system containing both a liquid phase (solvent) and a solid phase (integrated network, typically polymer network). The proportion of liquid is reduced stepwise. The rest of the liquid can be removed by drying and can be coupled with a thermal treatment to tailor the material properties of the solid.
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Glow-discharge radiation, γ-radiation, and ultraviolet irradiation have been used. These methods avoid the use of catalysts and solvent, but require low temperatures to produce regular polymers. Gas-phase polymerization typically produces irregular cuprene, whereas liquid-phase polymerization, conducted at −78 °C produces linear cis-polyacetylene, and solid-phase polymerization, conducted at still lower temperature, produces trans-polyacetylene.
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There are several ways to approach the topic of premelting, the most figurative way might be thermodynamically. A more detailed or abstract view on what physics is important for premelting is given by the Lifshitz and the Landau theories. One always starts with looking at a crystalline solid phase (fig. 1: (1) solid) and another phase.
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Fluorescent and radioactive antibodies have been used to locate or measure solid-phase antigens for many years. However, only recently has the labeled antibody been applied to measurement of antigen to sample. The method converts the unknown antigen into a tracable radioactive product. Immuno radiometric assay (IRMA) was first introduced by "Miles and Hales" in 1968.
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These reactors must be designed and operated according to regulatory standards and guidelines (See environmental engineering). Usually, aerobic decomposition is the first stage by which wastes are broken down in a landfill. These are followed by four stages of anaerobic degradation. Usually, solid organic material in solid phase decays rapidly as larger organic molecules degrade into smaller molecules.
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A major focus of his research is analytical separations theory and its application. His research group develops analytical techniques for molecular recognition and molecularly selective microextractions, and utilizes “green” separation procedures using aqueous solutions and nonvolatile polymeric systems. They have developed thin films for solid-phase micro extraction (SPME). Weber develops electrochemical detectors for use with liquid chromatography techniques.
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Vanhee, L.M.E., H.J. Nelis, and T. Coenye, Rapid Detection and Quantification of Aspergillus fumigatus in Environmental Air Samples Using Solid-Phase Cytometry. Environmental Science & Technology, 2009. 43(9): p. 3233-3239. Some other human diseases and symptoms have been proposed to be associated with indoor bioaerosol, but no deterministic conclusions could be drawn due to the insufficiency of evidence.
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Probert, J. M.; Rennex, D.; Bradley, M. (1996) Lanthionines for Solid Phase Synthesis. Tetrahedron Letters, 37, 1101-1104. The sulfur extrusion method is, however, the only pathway for lanthionine that has been employed in the total synthesis of a lantibiotic. Biosynthesis of the lanthionine bridge in peptidic natural products can be accomplished by through a number of different pathways.
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The technique extends the existing method of SPOT synthesis. In this method, libraries of glycopeptides are produced on a cellulose surface (e.g. filter paper) which acts as the solid phase. The glycopeptides are produced by spotting FMOC protected amino acids allowing the synthesis to be performed at microgram (nanomole) scale using very small amounts of glycoamino acids.
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Dry lubricants or solid lubricants are materials that, despite being in the solid phase, are able to reduce friction between two surfaces sliding against each other without the need for a liquid oil medium.Thorsten Bartels et al. "Lubricants and Lubrication" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Weinheim. The two main dry lubricants are graphite and molybdenum disulfide.
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Another application of direct insertion EI-MS is the characterization of novel synthetic carbon clusters isolated in the solid phase. These crystalline materials consist of C60 and C70 in the ratio of 37:1. In one investigation it has been shown that the synthetic C60 molecule is remarkably stable and that it retains its aromatic character.
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The main types of automation are classified by the type of solid-phase substrates, the methods for adding and removing reagents, and design of reaction chambers. Polymer resins may be used as a substrate for solid-phase.Hardin, J.; Smietana, F., Automating combinatorial chemistry: A primer on benchtop robotic systems. Mol Divers 1996, 1 (4), 270-274.
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In many ores of copper, zinc, lead, and molybdenum, the metals are in the form of sulfide minerals. These include the principal ore minerals of copper (chalcocite, chalcopyrite), zinc (sphalerite), lead (galena), and molybdenum (molybdenite). In addition, pyrite (an iron sulfide) is often present. Most sulfur is driven out of the solid phase in the roasting process.
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Pseudoproline dipeptides can be introduced in the same manner as other amino acid derivatives. The routine use of pseudoproline (oxazolidine) dipeptides in the FMOC solid phase peptide synthesis (SPPS) of serine- and threonine-containing peptides leads to remarkable improvements in quality and yield of crude products and helps avoid unnecessary repeat synthesis of failed sequences.Balbach J, Schmid FX. (2000).
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A complete organic synthesis pathway for the pyoverdine produced by P. aeruginosa strain PAO1 has been reported using solid-phase peptide synthesis. This protocol yielded pyoverdine at high yield (~48%) and is expected to substantially increase the ability of scientists to generate targeted derivatives on the pyoverdine scaffold and to facilitate the creation of siderophores with antimicrobial warheads.
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Through the development of RIA technology, researchers have been able to move beyond the use of radioactivity, and instead, use liquid- and solid-phase, competitive, and immunoradiometric assays. As a direct result of these monumental findings, researchers have continued the advancement of ligand binding assays in many facets in the fields of biology, chemistry, and the like.
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Like all actinides, einsteinium is rather reactive. Its trivalent oxidation state is most stable in solids and aqueous solution where it induces a pale pink color.Holleman, p. 1956 The existence of divalent einsteinium is firmly established, especially in the solid phase; such +2 state is not observed in many other actinides, including protactinium, uranium, neptunium, plutonium, curium and berkelium.
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2153-5515.0000263 # R. Galvez-Cloutier, G. Guesdon et A. Fonchain (2014) Lac-Mégantic : analyse de l'urgence environnementale, bilan et évaluation des impacts Rev. can. génie civ. 41: 531-539 (2014) dx.doi.org/10.1139/cjce-2014-0011. # N. Kamal, R. Galvez and G. Buelna (2014) Application of a solid phase extraction-HPLC method to quantify phenolic compounds in woodwaste leachate.
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1D photonic crystals doped with bio-active metals (i.e. silver) have been also proposed as sensing devices for bacterial contaminants. Similar planar 1D photonic crystals made of polymers have been used to detect volatile organic compounds vapors in atmosphere. In addition to solid-phase photonic crystals, some liquid crystals with defined ordering can demonstrate photonic color.
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In carburizing, the carbon can be in any of the solid, liquid, or gas phases. Although using carbon in the solid phase is usually the safest and easiest of these to work with, the process is difficult to control and the heating is inefficient. All these things must come into consideration when choosing a diffusion hardening process.
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Amination, condensation, esterification, Friedel–Crafts, Grignard, halogenation (esp. chlorination), and hydrogenation, respectively reduction (both catalytic and chemical) are most frequently mentioned on the websites of individual companies. Optically active cyanohydrins, cyclopolymerization, ionic liquids, nitrones, oligonucletides, peptide (both liquid- and solid-phase), electrochemical reactions (e.g., perfluorination) and steroid synthesis are promoted by only a limited number of companies.
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So, it was decided to increase the efficacy of this molecule creating other ones that could be more powerful. Among these 600 created molecules, there was the VIR-576 which was synthesized using the solid-phase peptide synthesis method. Moreover, another molecule was used to protect the amino groups, the fluorenylmethyloxycarbonyl chloride. The next step was the purification before lyophilizing it with mannitol.
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Polyamides occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made through step-growth polymerization or solid-phase synthesis yielding materials such as nylons, aramids, and sodium poly(aspartate). Synthetic polyamides are commonly used in textiles, automotive industry, carpets, kitchen utensils and sportswear due to their high durability and strength.
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Soxhlet extractor Extraction in chemistry is a separation process consisting in the separation of a substance from a matrix. Common examples include liquid-liquid extraction, and solid phase extraction. The distribution of a solute between two phases is an equilibrium condition described by partition theory. This is based on exactly how the analyte moves from the initial solvent into the extracting solvent.
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Accessed May 9, 2007. "Robert Bruce Merrifield, a biochemist who won the 1984 Nobel Prize in Chemistry for a method he named solid-phase peptide synthesis, died on May 14 at his home in Cresskill, N.J., after a long illness. He was 84." At the time of his death he was survived by his wife Libby, their 6 children and 16 grandchildren.
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Denaturing high performance liquid chromatography (DHPLC) uses reversed-phase HPLC to interrogate SNPs. The key to DHPLC is the solid phase which has differential affinity for single and double-stranded DNA. In DHPLC, DNA fragments are denatured by heating and then allowed to reanneal. The melting temperature of the reannealed DNA fragments determines the length of time they are retained in the column.
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The cis form of dinitrogen difluoride will react with strong fluoride ion acceptors such as antimony pentafluoride to form the N2F+ cation. : N2F2 \+ SbF5 → N2F+[SbF6]− In the solid phase, the observed N=N and N−F bond distances in the N2F+ cation are 1.089(9) and 1.257(8) Å respectively, among the shortest experimentally observed N−N and N−F bonds.
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Catalysts are useful because they increase the rate of a reaction without themselves being consumed and are therefore reusable. Heterogeneous catalysis typically involves solid phase catalysts and gas phase reactants. In this case, there is a cycle of molecular adsorption, reaction, and desorption occurring at the catalyst surface. Thermodynamics, mass transfer, and heat transfer influence the rate (kinetics) of reaction.
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This dipeptide is then condensed with glycine by glutathione synthetase to form glutathione. In chemistry, peptides are synthesized by a variety of reactions. One of the most-used in solid-phase peptide synthesis uses the aromatic oxime derivatives of amino acids as activated units. These are added in sequence onto the growing peptide chain, which is attached to a solid resin support.
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Parallel-Synthesis was developed by Mario Geysen and his colleagues and is not a true type of combinatorial synthesis, but can be incorporated into a combinatorial synthesis.H. M. Geysen, R. H. Meloen, S. J. Barteling Proc. Natl. Acad. Sci. USA 1984, 81, 3998. This group synthesized 96 peptides on plastic pins coated with a solid support for the solid phase peptide synthesis.
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When exposed to toxic substances, a decrease in luminescence can be observed and percent change in luminescence can be directly correlated to toxicity. Allivibrio fischeri were specifically chosen, as these bacteria could be preserved by freeze-drying to increase shelf life and use. Both solid phase (soils and sediment) and aqueous acute toxicity testing (described below) can be conducted using this technology.
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Matinkhoo et al. devised strategies to surmount three synthetic hurdles to give α-amanitin in 2018. First, enantioselective synthesis of solid phase peptide synthesis-compatible (2S,3R,4R)-4,5-dihydroxyisoleucine was afforded in 11 steps from 2-(benzyloxy)acetaldehyde. Two key stereochemistry-defining steps include Brown crotylation at (3R,4R)-positions, and asymmetric Strecker amino acid synthesis at the (2S)-α carbon.
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LNA or BNA. To obtain the desired oligonucleotide, the building blocks are sequentially coupled to the growing oligonucleotide chain in the order required by the sequence of the product (see Synthetic cycle below). The process has been fully automated since the late 1970s. Upon the completion of the chain assembly, the product is released from the solid phase to solution, deprotected, and collected.
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Discussed by: "Fluorous Peptides Get Ready to Heal" by Stephen Ritter, C&EN; 2007, 85 (37), pp. 36–37; "Putting the "F" in peptides" by Randall C Willis; Drug Discovery News 2007, December. #Montanari V.; Kumar, K. "Just Add Water: A New Fluorous Capping Reagent for Facile Purification of Peptides Synthesized on the Solid Phase." J. Am. Chem. Soc. 2004, 126, 9528-9529.
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In his book The Electric Furnace, Henri Moissan describes an early synthesis of strontium boride by mixing strontium borate, aluminum, and carbon in an electric furnace. Alternatively, a solid-phase synthesis of strontium boride can be carried out by reacting two moles of strontium carbonate with three moles of boron carbide and one mole of carbon inside a vacuum furnace.
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Retrieved Oct. 28, 2006. GC-MS testing is important in this capacity, because gas chromatography alone may record an inaccurately high reading of thujone as other compounds may interfere with and add to the apparent measured amount.Determination of a-/b-Thujone and Related Terpenes in Absinthe using Solid Phase Extraction and Gas Chromatography, Emmert et al. Retrieved Oct. 28, 2006.
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When \gamma = 0, the flow does not experience any buoyancy effect. Then the effective frictional shear stress for the solid phase is that of pure granular flow. In this case the force due to the pressure gradient is altered, the drag is high and the effect of the virtual mass disappears in the solid momentum. All this leads to slowing down the motion.
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With Walter Gilbert, Church published the first direct genomic sequencing method in 1984. Described in that publication were the cyclic application of fluids to a solid phase alternating with imaging, plus avoidance of bacterial cloning, strategies that are still used in current dominant Next-Generation Sequencing technologies. These technologies began to affect genome-scale sequencing in 2005. Church also helped initiate the Human Genome Project in 1984.
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The introduction of gradient pumps resulted in quicker separations and less solvent usage. In expanded bed adsorption, a fluidized bed is used, rather than a solid phase made by a packed bed. This allows omission of initial clearing steps such as centrifugation and filtration, for culture broths or slurries of broken cells. Phosphocellulose chromatography utilizes the binding affinity of many DNA- binding proteins for phosphocellulose.
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A 'sandwich' is formed of solid-phase antibody, suPAR and peroxidase-conjugated antibody. The concentration (ng/mL plasma) of suPAR in the patient sample is determined via interpolation, based on a calibration curve prepared from seven suPAR standards. Recombinant suPAR standards are calibrated against healthy human blood donor samples. Absorbance is measured using a microtiter plate reader, at 450 nm with a 650 nm reference filter.
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PyAOP ((7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate) is a coupling reagent used in solid phase peptide synthesis. It is a derivative of the HOAt family of coupling reagents. It is preferred over HATU, because it does not side react at the N-terminus of the peptide. Compared to the HOBt derivates, PyAOP (and HOAt in general) are more reactive due to the additional nitrogen.
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Antibodies that are specific for a particular protein (or group of proteins) are immobilized on a solid-phase substrate such as superparamagnetic microbeads or on microscopic agarose (non-magnetic) beads. The beads with bound antibodies are then added to the protein mixture, and the proteins that are targeted by the antibodies are captured onto the beads via the antibodies; in other words, they become immunoprecipitated.
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Antibodies that are specific for a particular protein, or a group of proteins, are added directly to the mixture of protein. The antibodies have not been attached to a solid-phase support yet. The antibodies are free to float around the protein mixture and bind their targets. As time passes, the beads coated in protein A/G are added to the mixture of antibody and protein.
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Other solid-phase indole syntheses were also reported, some of which use different scaffolds and metal catalysts to drive the reaction to completion. There are also a variety of other reactions that result in the same indole skeleton. In a review article, Taber et al. categorize these reactions into nine basic types of indole syntheses: Fischer, Mori, Hemetsberger, Buchwald, Sundberg, Madelung, Nenitzescu, van Leusen and Kanematsu.
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Conventional methods for DNA extraction, such as ethanol precipitation or preparations using commercial purification kits, cannot be integrated onto microchips because they require multiple hands-on processing steps. In addition, they also require large equipment and high volumes of reagents and samples. Silica resins avoid these issues through integration on microchips, where solid phase extraction provides accurate analysis of DNA on a small scale.
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In: Lebl, M., Houghten, R.A. (Eds.), American Peptide Society and Kluwer Academic Publishers, San Diego, 2001, pp. 263-4. and Meldal, M., Peptidotriazoles on solid-phase. Meldal received B.S. and Ph.D degrees in Chemical Engineering from DTU; his Ph.D. work focused on the synthetic chemistry of oligosaccharides. From 1983-1988 he was an independent research associate in organic chemistry at DTU and University of Copenhagen.
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His early publications on metallurgy include The solid phase welding of metals (1968). He participated in his first archaeological excavation in 1939, and became known for combining the two interests. Tylecote investigated early mining and smelting sites around the world, including Timna in Israel and the Roman silver mines of Rio Tinto in Spain. He also excavated sites in Sudan, Nigeria, Turkey, Iran and Afghanistan.
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In the solid phase SeO3 consists of cyclic tetramers, with an 8 membered (Se−O)4 ring. Selenium atoms are 4-coordinate, bond lengths being Se−O bridging are 175 pm and 181 pm, non- bridging 156 and 154 pm. SeO3 in the gas phase consists of tetramers and monomeric SeO3 which is trigonal planar with an Se−O bond length of 168.78 pm.
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In static methods a mixture is brought to equilibrium and the concentration of a species in the solution phase is determined by chemical analysis. This usually requires separation of the solid and solution phases. In order to do this the equilibration and separation should be performed in a thermostatted room. Very low concentrations can be measured if a radioactive tracer is incorporated in the solid phase.
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PVC produces HCl upon combustion almost quantitatively related to its chlorine content. Extensive studies in Europe indicate that the chlorine found in emitted dioxins is not derived from HCl in the flue gases. Instead, most dioxins arise in the condensed solid phase by the reaction of inorganic chlorides with graphitic structures in char-containing ash particles. Copper acts as a catalyst for these reactions.
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Ideally, the pH of samples should not be modified since it is preferable to test each sample at the original pH level. However, if it is necessary to adjust the pH this should be done by adding either sodium hydroxide solution or hydrochloric acid to the sample. Unlike water samples, soil and sediment samples are not homogenous.“Solid-Phase Test (SPT)” Azur Environmental. 1998.
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This is particularly important in solid-state chemistry, where one is interested in finding and identifying new materials. Once a pattern has been indexed, this characterizes the reaction product and identifies it as a new solid phase. Indexing programs exist to deal with the harder cases, but if the unit cell is very large and the symmetry low (triclinic) success is not always guaranteed.
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In March 1982 a practical course was hosted by the Department of Biochemistry, Technische Hochschule Darmstadt, Germany. M.H. Caruthers, M.J. Gait, H.G. Gassen, H.Koster, K. Itakura, and C. Birr among others attended. The program comprised practical work, lectures, and seminars on solid-phase chemical synthesis of oligonucleotides. A select group of 15 students attended and had an unprecedented opportunity to be instructed by the esteemed teaching staff.
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Diagram showing the effect of unsaturated lipids on a bilayer. The lipids with an unsaturated tail (blue) disrupt the packing of those with only saturated tails (black). The resulting bilayer has more free space and is, as a consequence, more permeable to water and other small molecules. At a given temperature a lipid bilayer can exist in either a liquid or a gel (solid) phase.
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5 Explosive powder. 6 Plasma jet. Polished section of an explosion weld with typical wave-structureExplosion welding (EXW) is a solid state (solid-phase) process where welding is accomplished by accelerating one of the components at extremely high velocity through the use of chemical explosives. This process is most commonly utilized to clad carbon steel plate with a thin layer of corrosion resistant material (e.g.
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Already studied by Bischoff (1968), magnesium ion is a long known inhibitor of calcite nucleation and crystal growth. The cation is the second-most abundant cation present in seawater after , as is the second anion after . Although closely resembling , the ionic radius of the naked cation is smaller. Some paradoxical consequences arise between its contrasted electrostatic behavior in the mineral solid phase and in aqueous solution.
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In the 1960s, Letsinger developed methods for solid phase synthesis of oligonucleotides, including the phosphoric triester method and the phosphoramidite synthesis. He thus laid the foundations for efficient automated synthesis of gene fragments and thus the rapid development of molecular biology. Letsingers later dealt with nanotechnology and its application in DNA diagnostics. In 2000, Letsinger was one of the founders of the biotechnology company Nanosphere Inc.
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As a result, a solid has a stable, definite shape, and a definite volume. Solids can only change their shape by an outside force, as when broken or cut. In crystalline solids, the particles (atoms, molecules, or ions) are packed in a regularly ordered, repeating pattern. There are various different crystal structures, and the same substance can have more than one structure (or solid phase).
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A column is prepared by packing a solid absorbent into a cylindrical glass or plastic tube. The size will depend on the amount of compound being isolated. The base of the tube contains a filter, either a cotton or glass wool plug, or glass frit to hold the solid phase in place. A solvent reservoir may be attached at the top of the column.
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In physics, condensation typically refers to a gas-liquid phase transition. In biology the term 'condensation' is used much more broadly and can also refer to liquid-liquid phase separation to form colloidal emulsions or liquid crystals within cells, and liquid-solid phase separation to form gels, sols, or suspensions within cells as well as liquid-to-solid phase transitions such as DNA condensation during prophase of the cell cycle or protein condensation of crystallins in cataracts. With this in mind, the term 'biomolecular condensates' was deliberately introduced to reflect this breadth (see below). Since biomolecular condensation generally involves oligomeric or polymeric interactions between an indefinite number of components, it is generally considered distinct from formation of smaller stoichiometric protein complexes with defined numbers of subunits, such as viral capsids or the proteasome - although both are examples of spontaneous molecular self-assembly or self- organisation.
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488x488pxRCA can amplify a single molecular binding event over a thousandfold, making it particularly useful for detecting targets with ultra-low abundance. RCA reactions can be performed in not only free solution environments, but also on a solid surface like glass, micro- or nano-bead, microwell plates, microfluidic devices or even paper strips. This feature makes it a very powerful tool for amplifying signals in solid-phase immunoassays (e.g., ELISA).
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The sample (fruits, vegetables, tobacco, etc.) is homogenized and centrifuged with a reagent and agitated for 1 minute. The reagents used depend on the type of sample to be analyzed. Following this, the sample is put through a dispersive solid phase extraction cleanup prior to analysis by gas-liquid chromatography or liquid- liquid chromatography. Samples prepared using the QuEChERS method can be processed more quickly using a homogenization instrument.
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Two-dimensional (thin film) semi- ordered lattices have been studied using an optical microscope, as well as those collected at electrode surfaces. Digital video microscopy has revealed the existence of an equilibrium hexatic phase as well as a strongly first- order liquid-to-hexatic and hexatic-to-solid phase transition. These observations are in agreement with the explanation that melting might proceed via the unbinding of pairs of lattice dislocations.
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A typical soil microecosystem may be restricted to less than a millimeter in its total depth range owing to steep variation in humidity and/or atmospheric gas composition. The soil grain size and physical and chemical properties of the substrate may also play important roles. Because of the predominant solid phase in these systems they are notoriously difficult to study microscopically without simultaneously disrupting the fine spatial distribution of their components.
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Hinrichs had a 40-year plus career with A.O. Smith Corporation, where he rose to Director of Manufacturing Engineering at its Automotive Products Co., leading a technical staff of eighty. Projects included gas metal arc welding, energy beam processes, solid phase joining and robotics.Stir Link Inc: Founder and Vice President of Technology - John F. Hinrichs. Hinrichs began working for A.O. Smith, a major producer of automotive frames, in 1954.
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In oil and gas industries, multiphase flow often implies to simultaneous flow of oil, water and gas. The term is also applicable to the properties of a flow in some field where there is a chemical injection or various types of inhibitors. In petroleum engineering, drilling fluid consists of a gas-solid phase. Furthermore, crude oil during flow through pipelines is a gas-oil-water three phase flow.
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In chemistry, an N-methylamide (NME) is a blocking group for the C-terminus end of peptides. When the carboxyl group of the C-terminus is replaced with a methylamide, further elongation of the peptide chain is prevented. C-Terminal modified peptides are also useful for the modulation of structure-activity relationships and for modifying conformational properties of peptides. N-Methylamides can be prepared directly from solid phase resin-bound peptides.
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There are several techniques to produce peptides chemically, generally it is by solid-phase protection chemistry. This means that any (protected) amino acid can be added into the nascent sequence. In November 2017, a team from the Scripps Research Institute reported having constructed a semi-synthetic E. coli bacteria genome using six different nucleic acids (versus four found in nature). The two extra 'letters' form a third, unnatural base pair.
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A Petryanov filter is a type of filtering cloth that is used for fine and super fine cleaning of air and other gases of fine aerosols. Gases contaminated with aerosols with a solid phase concentration of 0.5 mg/m3 can be cleaned by using these filters. These filters are commonly fabricated using electrospinning techniques, and were first developed in 1939 by Nathalie D. Rozenblum and Igor V. Petryanov-Sokolov.
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Thermochromic papers are used for thermal printers. One example is the paper impregnated with the solid mixture of a fluoran dye with octadecylphosphonic acid. This mixture is stable in solid phase; however, when the octadecylphosphonic acid is melted, the dye undergoes a chemical reaction in the liquid phase, and assumes the protonated colored form. This state is then conserved when the matrix solidifies again, if the cooling process is fast enough.
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SnBr2 is soluble in donor solvents such as acetone, pyridine and dimethylsulfoxide to give pyramidal adducts. A number of hydrates are known, 2SnBr2·H2O, 3SnBr2·H2O & 6SnBr2·5H2O which in the solid phase have tin coordinated by a distorted trigonal prism of 6 bromine atoms with Br or H2O capping 1 or 2 faces. When dissolved in HBr the pyramidal SnBr3− ion is formed. Like SnCl2 it is a reducing agent.
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The odd-numbered alkanes have a lower trend in melting points than even numbered alkanes. This is because even numbered alkanes pack well in the solid phase, forming a well-organized structure, which requires more energy to break apart. The odd-numbered alkanes pack less well and so the "looser" organized solid packing structure requires less energy to break apart. For a visualization of the crystal structures see.
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Black's Equation is a mathematical model for the mean time to failure (MTTF) of a semiconductor circuit due to electromigration: a phenomenon of molecular rearrangement (movement) in the solid phase caused by an electromagnetic field. The equation is: R. L. de Orio. Dissertation: "Electromigration Modeling and Simulation". 2010\. R.L. de Orio, H. Ceric, S. Selberherr. "Physically based models of electromigration: From Black’s equation to modern TCAD models" Microelectronics Reliability journal. 2010\.
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This method uses a rectangular block moved by a robot so that reagents can be pipetted by a robotic pipetting system. This block is separated into wells which the individual reactions take place. These compounds are later cleaved from the solid-phase of the well for further analysis. Another method is the closed reactor system which uses a completely closed off reaction vessel with a series of fixed connections to dispense.
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The energy associated with the quantum mechanical change primarily determines the frequency of the absorption line but the frequency can be shifted by several types of interactions. Electric and magnetic fields can cause a shift. Interactions with neighboring molecules can cause shifts. For instance, absorption lines of the gas phase molecule can shift significantly when that molecule is in a liquid or solid phase and interacting more strongly with neighboring molecules.
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Extraction of polyphenols can be performed using a solvent like water, hot water, methanol, methanol/formic acid, methanol/water/acetic or formic acid etc. Liquid–liquid extraction can be also performed or countercurrent chromatography. Solid phase extraction can also be made on C18 sorbent cartridges. Other techniques are ultrasonic extraction, heat reflux extraction, microwave-assisted extraction, critical carbon dioxide, pressurized liquid extraction or use of ethanol in an immersion extractor.
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Since atoms near the surface have fewer bonds and reduced cohesive energy, they require less energy to free from the solid phase. Melting point depression of high surface to volume ratio materials results from this effect. For the same reason, surfaces of bulk materials can melt at lower temperatures than the bulk material. The theoretical size-dependent melting point of a material can be calculated through classical thermodynamic analysis.
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This stage is known as incipient fluidization and occurs at this minimum fluidization velocity. Once this minimum velocity is surpassed, the contents of the reactor bed begin to expand and swirl around much like an agitated tank or boiling pot of water. The reactor is now a fluidized bed. Depending on the operating conditions and properties of solid phase various flow regimes can be observed in this reactor.
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The effects of London dispersion forces are most obvious in systems that are very non-polar (e.g., that lack ionic bonds), such as hydrocarbons and highly symmetric molecules like bromine (Br2, a liquid at room temperature) or iodine (I2, a solid at room temperature). In hydrocarbons and waxes, the dispersion forces are sufficient to cause condensation from the gas phase into the liquid or solid phase. Sublimation heats of e.g.
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The versatility of the system is controlled not only by changing temperature, but also by adding modifying moieties that allow for a choice of enhanced hydrophobic interaction, or by introducing the prospect of electrostatic interaction. These developments have already brought major improvements to the fields of hydrophobic interaction chromatography, size exclusion chromatography, ion exchange chromatography, and affinity chromatography separations, as well as pseudo-solid phase extractions ("pseudo" because of phase transitions).
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This chain structure means the ER fluid has become a solid. The electrostatic theory assumes just a two phase system, with dielectric particles forming chains aligned with an electric field in an analogous way to how magnetorheological fluid (MR) fluids work. An ER fluid has been constructed with the solid phase made from a conductor coated in an insulator. This ER fluid clearly cannot work by the water bridge model.
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Rebek's independent research began in the 1970s, with a method to detect reactive intermediates. This was invented through application of polymer-bound reagents. A precursor for the reactive intermediate was covalently attached to one solid phase while a trap was attached to a second such support. When transfer takes place between the solid phases, it requires the existence of a reactive intermediate, free in solution as shown below.
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Dissolved load can provide valuable information about the rate of soil formation and other processes of chemical erosion. In particular, the mass balance between the dissolved load and solid phase is helpful in determining surface dynamics. In addition, dissolved load can be used to reconstruct the climate of the Earth in the past. This is because chemical weathering is the major contributor to the dissolved load of a stream.
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Use of a solid-supported polyamine to scavenge excess reagent Over the years, a variety of methods have been developed to refine the use of solid-phase organic synthesis in combinatorial chemistry, including efforts to increase the ease of synthesis and purification, as well as non-traditional methods to characterize intermediate products. Although the majority of the examples described here will employ heterogeneous reaction media in every reaction step, Booth and Hodges provide an early example of using solid-supported reagents only during the purification step of traditional solution-phase syntheses. In their view, solution-phase chemistry offers the advantages of avoiding attachment and cleavage reactions necessary to anchor and remove molecules to resins as well as eliminating the need to recreate solid-phase analogues of established solution-phase reactions. The single purification step at the end of a synthesis allows one or more impurities to be removed, assuming the chemical structure of the offending impurity is known.
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Despite these disadvantages, spray forming remains an economic process for the production of difficult to manufacture, niche alloys. Large-scale porosity is more difficult to heal effectively and must be minimised by careful process control. In some cases, porosity is controlled by alloy additions which react with dissolved and entrapped gas to form a solid phase e.g. titanium added to copper billets to form titanium nitride with dissolved and entrapped nitrogen gas.
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The thermodynamic phases can be distinguished based on discrete versus continuous translational and orientational order. One of the transitions separates a solid phase with quasi-long range translational order and perfect long ranged orientational order from the hexatic phase. The hexatic phase shows short ranged translational order and quasi-long ranged orientational order. The second phase transition separates the hexatic phase from the isotropic fluid, where both, translational and orientational order is short ranged.
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The reaction can be catalyzed by Brønsted acids and/or by Lewis acids such as copper(II) trifluoroacetate hydrate and boron trifluoride. Several solid-phase protocols utilizing different linker combinations have been published. Dihydropyrimidinones, the products of the Biginelli reaction, are widely used in the pharmaceutical industry as calcium channel blockers, antihypertensive agents, and alpha-1-a-antagonists. More recently products of the Biginelli reaction have been investigated as potential selective Adenosine A2b receptor antagonists.
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Military and commercial C-4 are blended with different oils. It is possible to distinguish these sources by analyzing this oil by high-temperature gas chromatography–mass spectrometry. The oil and plasticizer must be separated from the C-4 sample, typically by using a non- polar organic solvent such as pentane followed by solid phase extraction of the plasticizer on silica. This method of analysis is limited by manufacturing variation and methods of distribution.
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Figure 2. Splint Aid Single Stranded mRNA/DNA T4 DNA Ligase Ligation The synthesis of an mRNA display library starts from the synthesis of a DNA library. A DNA library for any protein or small peptide of interest can be synthesized by solid-phase synthesis followed by PCR amplification. Usually, each member of this DNA library has a T7 RNA polymerase transcription site and a ribosomal binding site at the 5’ end.
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Solid phase extraction cartridges and disks are available with a variety of stationary phases, each of which can separate analytes according to different chemical properties. Most stationary phases are based on silica that has been bonded to a specific functional group. Some of these functional groups include hydrocarbon chains of variable length (for reversed phase SPE), quaternary ammonium or amino groups (for anion exchange), and sulfonic acid or carboxyl groups (for cation exchange).
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Colloidal phase separation is an important organising principle for compartmentalisation of both the cytoplasm and nucleus of cells into biomolecular condensates, similar in importance to compartmentalisation via lipid bilayer membranes - a type of liquid crystal. The term biomolecular condensate has been used to refer to clusters of macromolecules that arise via liquid-liquid or liquid-solid phase separation within cells. Macromolecular crowding strongly enhances colloidal phase separation and formation of biomolecular condensates.
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These orthogonally protected cysteines are incorporated during the solid-phase synthesis of the peptide. Successive removal of these groups, to allow for selective exposure of free thiol groups, leads to disulfide formation in a stepwise manner. The order of removal of the groups must be considered so that only one group is removed at a time. Thiol protecting groups used in peptide synthesis requiring later regioselective disulfide bond formation must possess multiple characteristics.
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Multiphase flows are not restricted to only three phases. An example of a four phase flow system would be that of direct- contact freeze crystallization in which, for example, butane liquid is injected into solution from which the crystals are to be formed, and freezing occurs as a result of the evaporation of the liquid butane. In this case, the four phases are, respectively, butane liquid, butane vapor, solute phase and crystalline (solid) phase.
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During 1985 and 1986 he performed postdoctoral work at Cambridge University; he was a postdoctoral research associate at the Medical Research Council Center, Laboratory of Molecular Biology. In 1996 he was appointed adjunct professor at Danish Technical University. Since 1998 he has led the synthesis group in the Department of Chemistry of the Carlsberg Laboratory and since 1997, he has served as head of the Solid-Phase Organic Chemistry and Enzymatic Reaction Center (SPOCC).
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Metabolism of JWH-018 was assessed using Wistar rats which had been administered an ethanolic extract containing JWH-018. Urine was collected for 24 hours, followed by extraction of JWH-018 metabolites using both liquid-liquid extraction and solid-phase extraction. GC-MS was utilized to separate and identify the extracted compounds. JWH-018 and its N-dealkylated metabolite were only detected in small amounts, with hydroxylated N-dealkylated metabolites comprising the primary signal.
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The GC-EI-MS is also used in forensic science. One example is the analysis of five local anesthetics in blood using headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry–electron impact ionization selected ion monitoring (GC–MS–EI- SIM). Local anesthesia is widely used but sometimes these drugs can cause medical accidents. In such cases an accurate, simple, and rapid method for the analysis of local anesthetics is required.
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Ninhydrin can also be used to monitor deprotection in solid phase peptide synthesis (Kaiser Test). The chain is linked via its C-terminus to the solid support, with the N-terminus extending off it. When that nitrogen is deprotected, a ninhydrin test yields blue. Amino-acid residues are attached with their N-terminus protected, so if the next residue has been successfully coupled onto the chain, the test gives a colorless or yellow result.
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Scheme of part of the beta-sheet of the RANTES structure. Circled amino acids were incorporated as pseudo-Proline dipeptides. Traditionally, solid-phase synthesis has relied on polystyrene-based resins for the synthesis of all kinds of peptides. However, due to their high hydrophobicity, these resins have certain limitations, particularly in the synthesis of complex peptides, and in such cases, polyethylene glycol (PEG)-based resins are often found to give superior results.
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Experimental melting curves for near spherical metal nanoparticles exhibit a similarly shaped curve. Melting point depression is a very important issue for applications involving nanoparticles, as it decreases the functional range of the solid phase. Nanoparticles are currently used or proposed for prominent roles in catalyst, sensor, medicinal, optical, magnetic, thermal, electronic, and alternative energy applications. Nanoparticles must be in the solid state to function at elevated temperatures in several of these applications.
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Zone distillation is a distillation process in long container with partial melting of refined matter in moving liquid zone and condensation of vapor in the solid phase at condensate pulling in cold area. The process is worked in theory. When zone heater is moving from the top to the bottom of the container then solid condensate with irregular impurity distribution is forming. Then most pure part of the condensate may be extracted as product.
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Weathering is the break down of rocks, soil, and minerals through contact with water, the atmosphere, and biological organisms, converting solid phase minerals to dissolved phase compounds. This process can introduce nutrients, most notably phosphorus, into the Columbia watershed. Both chemical and physical weathering occur, usually together, and this coupling tends to accelerate the other. Precipitation varies across the basin, influencing the amount of weathering and subsequent runoff that transports this material into the basin.
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The positively charged ammonium ion of these molecules interacts with the DNA, and the alkyl chain with the hydrophobic surface of the solid phase. Therefore, when heteroduplexes are partially denaturated by heating, the negative charges undergo partial relocation and the interaction force between DNA heteroduplexes and column decreases in comparison to the strength of interaction of the homoduplexes. These will therefore be eluted less rapidly by the mobile phase (consisting of acetonitrile).
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Site-specific characteristics have a major influence on contaminant bioavailability and no standardized tests have been developed. However, there are a number of chemical and biological tests used to estimate bioavailability including a direct measurement of contaminant bioaccumulation in earthworms (Eisenia fetida). Estimates of bioavailability can also be obtained from chemical solid-phase soil extractions. Fugacity modelling of bioavailability is based on the solubility and partitioning of compounds into aqueous and non-aqueous phases.
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Some of the solid-phase water could be in the form of ice VII. Maintaining a subsurface ocean depends on the rate of internal heating compared with the rate at which heat is removed, and the freezing point of the liquid. Ocean survival and tidal heating are thus intimately linked. Smaller ocean planets would have less dense atmospheres and lower gravity; thus, liquid could evaporate much more easily than on more massive ocean planets.
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In IRMA, the antibodies are labeled with radioisotopes which are used to bind antigens present in the specimen. When a positive sample is added to the tubes, radioactively labeled (labeled with I125 or I131 radioisotopes) antibodies bind to the free epitopes of antigens and form an antigen-antibody complex. Unbound labeled antibodies are removed by a second reaction with a solid phase antigen. The amount of radioactive remaining in the solution is direct function of the antigen concentration.
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Honey bees can be used to locate mines in two ways: passive sampling and active detection. In passive sampling, their mop- like hairs, which are electrostatically charged, collect a variety of particles including chemicals leaking from explosives. The chemicals are also present in water that they bring back and air that they breathe. Methods such as solid phase microextraction, sorbent sol-gels, gas chromatography and mass spectrometry can be used to identify explosive chemicals in the hive.
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Recently, a solid-phase version of the Robinson–Gabriel synthesis has been described. The reaction requires trifluoroacetic anhydride to be used as the cyclodehydrating agent in etheral solvent and the 2-acylamidoketone be linked by the nitrogen atom to a benzhydrylic-type linker. One-pot synthesis of oxazoles using oxazolone templates as described by Keni et al. A one-pot diversity-oriented synthesis has been developed via a Friedel-Crafts/Robinson–Gabriel synthesis using a general oxazolone template.
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The stationary phase comes in the form of a packed syringe- shaped cartridge, a 96 well plate, a 47- or 90-mm flat disk, or a microextraction by packed sorbent (MEPS) device, a SPE method that uses a packed sorbent material in a liquid handling syringe.M. Abdel-Rehim, AstraZeneca Application “Syringe for solid phase microextraction”, Current Patents Gazette, week 0310, WO 03019149, p. 77, (2003). These can be mounted on its specific type of extraction manifold.
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A crude oil distillation column. Knowledge of volatility is often useful in the separation of components from a mixture. When a mixture of condensed substances contains multiple substances with different levels of volatility, its temperature and pressure can be manipulated such that the more volatile components change to a vapor while the less volatile substances remain in the liquid or solid phase. The newly formed vapor can then be discarded or condensed into a separate container.
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Fluorous chemistry involves the use of perfluorinated compounds or perfluorinated substituents to facilitate recovery of a catalyst or reaction product. Perfluorinated groups impart unique physical properties including high solubility in perfluorinated solvents. This property can be useful in organic synthesis and separation methods such as solid phase extraction.István T. Horváth (Ed.) Topics in Current Chemistry 2011 "Fluorous Chemistry" In practice, a perfluorinated alkyl group is incorporated into an otherwise conventional organic reagent as an affinity tag.
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The pore space of soil contains the liquid and gas phases of soil, i.e., everything but the solid phase that contains mainly minerals of varying sizes as well as organic compounds. In order to understand porosity better a series of equations have been used to express the quantitative interactions between the three phases of soil. Macropores or fractures play a major role in infiltration rates in many soils as well as preferential flow patterns, hydraulic conductivity and evapotranspiration.
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Since the process requires additional energy, it is an endothermic change. The enthalpy of sublimation (also called heat of sublimation) can be calculated by adding the enthalpy of fusion and the enthalpy of vaporization. Comparison of phase diagrams of carbon dioxide (red) and water (blue) showing the carbon dioxide sublimation point (middle-left) at 1 atmosphere. As dry ice is heated, it crosses this point along the bold horizontal line from the solid phase directly into the gaseous phase.
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This is a modification of the method of oxidative tethering to a para-methoxybenzyl ether. The difference here is that the para-alkoxybenzyl group is attached to a solid support; the β-mannoside product is released into the solution phase in the last step, while the by-products remain attached to the solid phase. This makes the purification of the β-glycoside easier; it is formed as the almost exclusive product.Ito, Y.; Ogawa, T. J. Am. Chem. Soc.
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The soil matrix is the solid phase of soils, and comprise the solid particles that make up soils. Soil particles can be classified by their chemical composition (mineralogy) as well as their size. The particle size distribution of a soil, its texture, determines many of the properties of that soil, in particular hydraulic conductivity and water potential, but the mineralogy of those particles can strongly modify those properties. The mineralogy of the finest soil particles, clay, is especially important.
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That is to say it will assume a solid phase at the temperature of the carrier and liquid phase at some higher temperature. The range of commercially available ink compositions which could meet the requirement of the invention are not know at the present time. However, satisfactory printing according to the invention has been achieved with a conductive metal alloy as ink. It is extremely hard at room temperature and adheres well to the surface of the carrier.
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Secondly, chemoselective inner ring closure by fluorocyclization between 6-hydroxytrytophan and cysteine was achieved by intra-annular Savige-Fontana reaction. This requires a solid phase peptide synthesis-compatible, and methyliminodiacetic acid (MIDA), a boron protecting group, orthogonal amino acid in 5 steps. As a final step, enantioselective oxidation at the tryptathionine linkage was achieved using a bulky organic oxidizing agent and an optimized solvent system to afford the desired the bio- reactive (R)-enantiomer sulfoxide, completing the total synthesis.
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Using high pressure, pressure injection cells are used for two applications: densely packing nanobore capillary columns (micro-columns) with solid-phase particles for use in LC/MS analysis; and precisely infusing microliter samples directly from microcentrifuge tubes into mass spectrometers without additional transfers, wasted sample, or contact with metallic surfaces which adsorb some negatively charged molecules such as phosphopeptides.Watson, J. Throck & Sparkman, David O. Introduction to Mass Spectrometry: Instrumentation, Applications, and Strategies for Data Interpretation, Wiley, 2007.
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In the 1970s, substantially more reactive P(III) derivatives of nucleosides, 3'-O-chlorophosphites, were successfully used for the formation of internucleosidic linkages. This led to the discovery of the phosphite triester methodology. The group led by M. Caruthers took the advantage of less aggressive and more selective 1H-tetrazolidophosphites and implemented the method on solid phase. Very shortly after, the workers from the same group further improved the method by using more stable nucleoside phosphoramidites as building blocks.
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The opposite process is called deposition, where CO2 changes from the gas to solid phase (dry ice). At atmospheric pressure, sublimation/deposition occurs at or 194.65 K. The density of dry ice varies, but usually ranges between about . The low temperature and direct sublimation to a gas makes dry ice an effective coolant, since it is colder than water ice and leaves no residue as it changes state. Its enthalpy of sublimation is 571 kJ/kg (25.2 kJ/mol).
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Increased amounts can actually have negative effects however, and cause growth inhibition to the development of plant crops. It has been used on many different crops including apples, olives, oranges, potatoes, and various other hanging fruits. In order for it to obtain its desired effects it must be applied in concentrations ranging from 20–100 µg/mL.A. Navalón, R. Blanc, J.L. Vilchez Determination of 1-naphthylacetic acid in commercial formulations and natural waters by solid-phase spectrofluorimetry Mikcrochim.
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Some alternative procedures describe unspecific covalent binding and adhesive immobilization. However, lithographic methods can be used to overcome the problem of excessive number of coupling cycles. Combinatorial synthesis of peptide arrays onto a microchip by laser printing has been described, where a modified colour laser printer is used in combination with conventional solid- phase peptide synthesis chemistry. Amino acids are immobilized within toner particles, and the peptides are printed onto the chip surface in consecutive, combinatorial layers.
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Many methods have become available for the determination of aflatoxin M1 in milk. In particular, solid-phase correction and immunoaffinity chromatography cartridges offer good possibilities for efficient clean up. Both thin-layer chromatography (TLC) and high performance liquid chromatography (HPLC) are adequate techniques to separate and determine aflatoxin M1 in extracts of milk. Enzyme-linked immune sorbent assay (ELISA) is more popular, due to ease of use and properties which are conducive to rapid screening and semi-quantitative determination.
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Synthesis of spiroligomer building blocks (bis-amino acids). (a) Cbz-Cl, NaHCO3, 1:10 dioxane/water (b) Jones reagents, acetone, 0 oC to rt; (c) Isobutylene, H2SO4 (cat.), CH2Cl2, 0 oC to rt; (d) (NH4)2CO3, KCN, 1:1 EtOH/water, sealed tube; (e) (i) AcOH/Ac2O, Reflux; (ii) 2M HCl, reflux; (iii) Recrystallization Spiroligomers are synthesized in a step-wise approach by adding a single bis-amino acid at each stage of the synthesis. This stepwise elongation allows for complete control of the stereochemistry, as any bis-amino acid can be incorporated to allow for elongation; or any mono-amino acid can be added to terminate a chain. This can be accomplished using either solution-phase or solid-phase reactions. Zachary Z. Brown, Jennifer Alleva, and Christian E. Schafmeister, "Solid-Phase Synthesis of Functionalized Bis-Peptides" Biopolymers, (2011), 96(5), 578-585 The original synthesis of spiroligomers allowed for functionalization on the ends of the oligomers, but it did not allow for the incorporation of functionality on the interior diketopiperazine (DKP) nitrogens.
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The precipitation of a second phase within the lattice of a material creates physical blockades through which a dislocation cannot pass. The result is that the dislocation must bend (which requires greater energy, or a greater stress to be applied) around the precipitates, which inevitably leaves residual dislocation loops encircling the second phase material and shortens the original dislocation. This schematic shows how a dislocation interacts with solid phase precipitates. The dislocation moves from left to right in each frame.
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One of the chemical polymerization methods is solid-phase synthesis, which can be used to synthesize peptides consisted of natural and non-natural amino acids. In this method, the monomers are attached to the polymer chain via amidation between carbonyl group and amino group. For purpose of sequence control, the amino groups are usually protected by 9-fluorenylmethyloxycarbonyl group (Fmoc) and t-butyloxycarbonyl (Boc), which can be removed under base and acid environment respectively to participate into next-round chain elongation.
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University of Bristol, Chemspeed SWING platform: (from left to right) Programming station; SWING platform; Huber thermostat.One automated synthesis facility is Bristol Automated Synthesis Facility based at the University of Bristol (UK) run by prof. Varinder Aggarwal. Facility uses Chemspeed Technologies SWING platform available for automated parallel chemical synthesis, with capabilities including inert atmosphere, liquids and solids dispensing, temperature control from −70 °C to 120 °C, high pressure (up to 80 bar) and integrated solid-phase extraction with dedicated LC-MS off-line analysis.
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HBTU (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate, Hexafluorophosphate Benzotriazole Tetramethyl Uronium) is a coupling reagent used in solid phase peptide synthesis. It was introduced in 1978 and shows resistance against racemization. It is used because of its mild activating properties. The product obtained by reaction of HOBt with tetramethyl chloro uronium salt (TMUCl) was assigned to a uronium type structure, presumably by analogy with the corresponding phosphonium salts, which bear a positive carbon atom instead of the phosphonium residue.
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Membrane bioreactors (MBR) are activated sludge systems using a membrane liquid-solid phase separation process. The membrane component uses low pressure microfiltration or ultrafiltration membranes and eliminates the need for a secondary clarifier or filtration. The membranes are typically immersed in the aeration tank; however, some applications utilize a separate membrane tank. One of the key benefits of an MBR system is that it effectively overcomes the limitations associated with poor settling of sludge in conventional activated sludge (CAS) processes.
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The chemical synthesis of peptides can be carried out using classical solution-phase techniques, although these have been replaced in most research and development settings by solid-phase methods (see below). Solution-phase synthesis retains its usefulness in large- scale production of peptides for industrial purposes however. Chemical synthesis facilitates the production of peptides which are difficult to express in bacteria, the incorporation of unnatural amino acids, peptide/protein backbone modification, and the synthesis of D-proteins, which consist of D-amino acids.
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Once cyclization has taken place, the peptide is cleaved from resin by acidolysis and purified. The strategy for the solid-phase synthesis of cyclic peptides in not limited to attachment through Asp, Glu or Lys side chains. Cysteine has a very reactive sulfhydryl group on its side chain. A disulfide bridge is created when a sulfur atom from one Cysteine forms a single covalent bond with another sulfur atom from a second cysteine in a different part of the protein.
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Nevertheless, the average properties of lab produced humic substances from different sources are remarkably similar. Humic substances in soils and sediments can be divided into three main fractions: humic acids, fulvic acids, and humin. Their presence and relative abundance is inferred by lab extraction, a process which alters their original form beyond recognition. The humic and fulvic acids are extracted as a colloidal sol from soil and other solid phase sources into a strongly basic aqueous solution of sodium hydroxide or potassium hydroxide.
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Native chemical ligation is carried out in aqueous solution and frequently gives near-quantitative yields of the desired ligation product. The challenge lies in the preparation of the necessary unprotected peptide- thioester building block. Peptide-thioesters are usually prepared by Boc chemistry SPPS; a thioester-containing peptide cannot be synthesized using a nucleophilic base, thus disfavoring Fmoc chemistry. Fmoc chemistry solid phase peptide synthesis techniques for generating peptide-thioesters are known; they make use of modifications of the Kenner 'safety catch' linker.
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Within the Earth's atmosphere and surface, the liquid phase is the most common and is the form that is generally denoted by the word "water". The solid phase of water is known as ice and commonly takes the structure of hard, amalgamated crystals, such as ice cubes, or loosely accumulated granular crystals, like snow. Aside from common hexagonal crystalline ice, other crystalline and amorphous phases of ice are known. The gaseous phase of water is known as water vapor (or steam).
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ConA interacts with the surface mannose residues of many microbes, including the bacteria E. coli, and Bacillus subtilis and the protist Dictyostelium discoideum. It has also been shown as a stimulator of several matrix metalloproteinases (MMPs). ConA has proven useful in applications requiring solid-phase immobilization of glycoenzymes, especially those that have proved difficult to immobilize by traditional covalent coupling. Using ConA-couple matrices, such enzymes may be immobilized in high quantities without a concurrent loss of activity and/or stability.
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Solid-phase microextraction (SPME) techniques are used to collect VOCs at low concentrations for analysis. A lower explosion limit (LEL) detector such as a flame ionization detector (FID) may be used to measure the total concentration of VOCs, though it cannot differentiate between or identify the particular species of VOC. Similarly, a photoionization detector (PID) may also be used, though PIDs are less accurate. Direct injection mass spectrometry techniques are frequently utilized for the rapid detection and accurate quantification of VOCs.
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The inverse of this, when one solid phase transforms into two solid phases during cooling, is called the eutectoid. A complex phase diagram of great technological importance is that of the iron–carbon system for less than 7% carbon (see steel). The x-axis of such a diagram represents the concentration variable of the mixture. As the mixtures are typically far from dilute and their density as a function of temperature is usually unknown, the preferred concentration measure is mole fraction.
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The chemical synthesis of large peptides is still limited by problems of low solvation during solid phase peptide synthesis (SPPS) or limited solubility of fully protected peptide fragments: even chemoselective ligation methods are hampered by self- association of unprotected peptide blocks. The elucidation of the relationship between preferred conformation of a growing peptide chain and its physicochemical properties reveals that β-sheet (beta-sheet) formation is often paralleled by significant decrease in solvation and solubility.Mutter, M., Vuilleumier, S., Angew. Chem., (1989) 101, p.
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Composition of a polyethylene glycol (PEG)-based resin. Recently, an efficient stepwise solid-phase synthesis of RANTES (24-91) was published. RANTES is a major HIV-suppressive factor produced by CD8+ T Cells.Cocchi F. et al., Science 270:1811-1815, 1995 The serine protease CD26/dipeptidyl-peptidase IV (CD26/DPP IV) induces a NH2-terminal truncation from RANTES (1-91) to RANTES(24-91), which inhibits the infection of monocytes by an M-tropic HIV-1 strainProost P. et al.
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Corrections can be made by testing a sample of similar particle composition that is known to not be toxic. This test consists of two controls and 13 sample dilutions in duplicate. The Solid-Phase Test exposes the bacteria in such a way that is not always possible with pore water and elutriate. _Acute Toxicity Comparison & Inhibition Tests_ are the best procedures for testing samples with a low level of toxicity when an ECxx can not be determined using the Basic Test.
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Marcaurelle received her B.A. in Chemistry from the College of the Holy Cross in 1997, where she worked with Prof. Timothy Curran on dipeptide scaffolds. She enrolled in UC-Berkeley to pursue a Ph.D. in Chemistry under Carolyn Bertozzi, working on a variety of new glycoside-linking technologies to produce glycoprotein mimetics for natural substances like mucin. Marcaurelle completed a one-year postdoctoral fellowship at the Massachusetts Institute of Technology, working with Peter Seeberger on solid-phase synthesis of oligosaccharides.
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Morphine and its major metabolites, morphine-3-glucuronide and morphine-6-glucuronide, can be detected in blood, plasma, hair, and urine using an immunoassay. Chromatography can be used to test for each of these substances individually. Some testing procedures hydrolyze metabolic products into morphine before the immunoassay, which must be considered when comparing morphine levels in separately published results. Morphine can also be isolated from whole blood samples by solid phase extraction (SPE) and detected using liquid chromatography-mass spectrometry (LC-MS).
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There are two stages in the liquid crystals: #the hot nematic stage is the closest to the liquid phase where the molecules are freely moving around and only partly ordered. #the cold smectic stage is closest to a solid phase where the molecules align themselves into tightly wound chiral matrixes. Liquid crystal thermometers portray temperatures as colors and can be used to follow temperature changes caused by heat flow. They can be used to observe that heat flows by conduction, convection, and radiation.
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Most developmental peptides are synthesized by this method, which lends itself to automation. As the intermediate products resulting from individual synthetic steps cannot be purified, a selectivity of effectively 100% is essential for the synthesis of larger-peptide molecules. Even at a selectivity of 99% per reaction step, the purity will drop to less than 75% for a dekapeptide (30 steps). Therefore, for industrial quantities of peptides not more than 10–15 amino acid peptides can be made using the solid- phase method.
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But the main advantage is the speed of response, there are few other effects able to control such large amounts of mechanical or hydraulic power so rapidly. Unfortunately, the increase in apparent viscosity experienced by most Electrorheological fluids used in shear or flow modes is relatively limited. The ER fluid changes from a Newtonian liquid to a partially crystalline "semi-hard slush". However, an almost complete liquid to solid phase change can be obtained when the electrorheological fluid additionally experiences compressive stress.
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Solid phase extraction also can be used to isolate YTXs from the sample medium. This technique separates the components of a mixture by using their different chemical and physical properties. This method is robust and extremely useful when small sample volumes are being analysed. It is advantageous over solvent extraction, as it concentrates (can give sample enrichment up to the power of 10) and can purify the sample by the removal of salts and nonpolar substances which can interfere with the final analysis.
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There are electronic devices that can detect ppm concentrations despite not being particularly selective. Others can predict with reasonable accuracy the molecular structure of the volatile organic compounds in the environment or enclosed atmospheres and could be used as accurate monitors of the chemical fingerprint and further as health monitoring devices. Solid-phase microextraction (SPME) techniques are used to collect VOCs at low concentrations for analysis. Direct injection mass spectrometry techniques are frequently utilized for the rapid detection and accurate quantification of VOCs.
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Mabinlins, as proteins, are readily soluble in water and found to be highly sweet; however, mabinlin-2 with its high heat stability has the best chance to be used as a sweetener. During the past decade, attempts have been made to produce mabinlin-2 industrially. The sweet-tasting protein has been successfully synthesised by a stepwise solid-phase method in 1998, however the synthetic protein had an astringent-sweet taste. Mabinlin-2 has been expressed in transgenic potato tubers, but no explicit results have been reported yet.
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DNA Double Helix Artificial gene synthesis, or gene synthesis, refers to a group of methods that are used in synthetic biology to construct and assemble genes from nucleotides de novo. Unlike DNA synthesis in living cells, artificial gene synthesis does not require template DNA, allowing virtually any DNA sequence to be synthesized in the laboratory. It comprises two main steps, the first of which is solid-phase DNA synthesis, sometimes known as DNA printing. This produces oligonucleotide fragments that are generally under 200 base pairs.
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Solid-state chemistry, also sometimes referred as materials chemistry, is the study of the synthesis, structure, and properties of solid phase materials, particularly, but not necessarily exclusively of, non-molecular solids. It therefore has a strong overlap with solid-state physics, mineralogy, crystallography, ceramics, metallurgy, thermodynamics, materials science and electronics with a focus on the synthesis of novel materials and their characterisation. Solids can be classified as crystalline or amorphous on basis of the nature of order present in the arrangement of their constituent particles.
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The effects of ion suppression can be minimized by reducing the complexity of the sample, for instance through sample extraction techniques such as solid phase extraction, or by separation of analytes of interest using chromatographic separation. However, these sample preparation steps can be laborious, time-consuming and expensive. PESI enables a reduction in ion suppression without the need for sample pre- treatment. By separating the ionization of different analytes, components causing ion suppression can be exhausted before enabling the ionization of components of interest.
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A solution of aquacyano-corrinoids, such as cobalamin or cobinamide, reacts with free cyanide in an aqueous sample. The binding of cyanide to the corrinoid cobalt center leads to a color change from orange to violet, allowing for semi-quantification by naked-eye. Precise quantification of the cyanide content is feasible by UV-vis spectroscopy. Absorption of the corrinoid on a solid phase, allows detection of cyanide even in colored samples, rendering this method appropriate for the analysis of cyanide in water, wastewater, blood, and food.
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Long-range order has been observed in thin films of colloidal liquids under oil—with the faceted edge of an emerging single crystal in alignment with the diffuse streaking pattern in the liquid phase. Structural defects have been directly observed in the ordered solid phase as well as at the interface of the solid and liquid phases. Mobile lattice defects have been observed via Bragg reflections, due to the modulation of the light waves in the strain field of the defect and its stored elastic strain energy.
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Approximately 50 hazelnuts can be found in each jar of Nutella, as claimed by the company. The cocoa powder is then mixed with the hazelnuts along with sugar, vanillin and skim milk in a large tank, until it becomes a paste-like spread. Modified palm oil is then added to help retain the solid phase of the Nutella at room temperature, which substitutes for the butter found in the cocoa bean. Whey powder is then added to the mix to act as a binder for the paste.
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Peptide synthesis can be easily conducted by the established method of solid-phase chemistry in grams or kilograms quantities. The d-isomer conformation can be used for peptide synthesis. Nanostructures can be made by dissolving dipeptides in 1,1,1,3,3, 3-hexafluoro-2-propanol at 100 mg/ml and then diluting it with water for a concentration of less than 2 mg/ml. Multiwall nanotubes with a diameter of 80–300 nm, made of dipeptides from the diphenylalanine motif of Alzheimer's β-amyloid peptide are made by this method.
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Marzipan is a food emulsion that contains four phases: a solid phase of suspended particles including almonds and sugars, a suspended air pocket phase formed from incorporated air during mixing, a water phase, and a lipid phase from almond oil. The phases can separate when left alone for long periods of time. It is stabilized by the phospholipids and triglycerides found in the almond cells. The fatty acids found in almonds include saturated fats such as stearic acid and unsaturated fats such as linoleic acid.
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HYCOR Biomedical is an American corporation specializing in the manufacture and supply of high-quality in vitro diagnostic products for blood testing for allergies. The company has offices in Garden Grove, California, and Kassel, Germany. HYCOR Biomedical mainly produces tests and equipment relating to Allergy. Current equipment released by HYCOR includes the fully-automated NOVEOS Immunoanalyzer that uses only 4 microliters of sample per test, paramagnetic microparticles as a solid phase, chemiluminescence and fluorescence methodology for high sensitivity, and liquid ready-to-use reagents.
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Commercially available oligonucleotide SNP arrays can be solid phase (Affymetrix, Santa Clara, CA, USA) or bead-based (Illumina, SanDiego, CA, USA). Despite the diversity of platforms, ultimately they all use genomic DNA from disrupted cells to recreate a high resolution karyotype in silico. The end product does not yet have a consistent name, and has been called virtual karyotyping, digital karyotyping, molecular allelokaryotyping, and molecular karyotyping. Other terms used to describe the arrays used for karyotyping include SOMA (SNP oligonucleotide microarrays) and CMA (chromosome microarray).
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It is seen in ice at high pressure (Ice X), and also in the solid phase of many anhydrous acids such as hydrofluoric acid and formic acid at high pressure. It is also seen in the bifluoride ion [F−H−F]−. Much has been done to explain the symmetric hydrogen bond quantum-mechanically, as it seems to violate the duet rule for the first shell: The proton is effectively surrounded by four electrons. Because of this problem, some consider it to be an ionic bond.
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Although Biosearch Technologies was founded in 1993, its roots can be traced back to 1979 when it was preceded by Dr. Ronald Cook's first company, Biosearch, Inc. Biosearch, Inc. experienced 9 years of DNA synthesis instrumentation and chemistry by playing a key role in engineering and manufacturing one of the first automated solid-phase DNA synthesis instruments, the SAM I. As time progressed, Biosearch was also able to bring other DNA synthesizers to market such as the Biosearch 8700, Biosearch 8800 Prep, and the Cyclone.
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Troitzsch, J.H. Flame retardants. Demands and innovations. 5th International SKZ Conference on Flame Retardant Plastics, Shanghai, China, 21 March 2014 The most important flame retardants systems used act either in the gas phase where they remove the high energy radicals H and OH from the flame or in the solid phase, where they shield the polymer by forming a charred layer and thus protect the polymer from being attacked by oxygen and heat.Lewin, M., Weil, E. Mechanisms and modes of action in flame retardancy of polymers, p.
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Entropy difference between crystal and undercooled melt As a liquid is supercooled, the difference in entropy between the liquid and solid phase decreases. By extrapolating the heat capacity of the supercooled liquid below its glass transition temperature, it is possible to calculate the temperature at which the difference in entropies becomes zero. This temperature has been named the Kauzmann temperature. If a liquid could be supercooled below its Kauzmann temperature, and it did indeed display a lower entropy than the crystal phase, the consequences would be paradoxical.
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Warner is an analytical/materials Chemist, with research focuses on fluorescence spectroscopy, organized media, and ionic liquid chemistry, particularly as applied to solid phase materials. He is known for his mentoring of Chemistry students, and focus on the advancement of women and chemists of color. He has won numerous awards for his mentoring including. He has graduated 67 PhD students from his group, including a significant number of women and minorities, helping to make Louisiana State University the leader in producing women and African American PhD students.
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A drawback of these plates is that they are highly absorptive and this increases the incidence of non-specific binding of components used in the ELISA. Non-specific binding to the plates is reduced through the use of buffers containing proteins such as casein and non-ionic detergents such as Tween 20. After coating, excess sample is removed and the plate typically treated with a 1% casein containing solution. Subsequent to this the solid phase is treated with antibodies raised against the antigen of interest.
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The simplest method of lipid separation is the use of thin layer chromatography (TLC). Although not as sensitive as other methods of lipid detection, it offers a rapid and comprehensive screening tool prior to more sensitive and sophisticated techniques. Solid-phase extraction (SPE) chromatography is useful for rapid, preparative separation of crude lipid mixtures into different lipid classes. This involves the use of prepacked columns containing silica or other stationary phases to separate glycerophospholipids, fatty acids, cholesteryl esters, glycerolipids, and sterols from crude lipid mixtures.
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Vapour pressure of ethyl cyanoacetate Ethyl cyanoacetate is a colorless liquid, it boils at atmospheric pressure at 209 °C. The vapor pressure follows the Antoine equation log10(P) = A−(B/(T+C)) (P in bar, T in K) with A = 7.46724, B = 3693.663 and C = 16.138 in the temperature range from 341 to 479 K In solid phase, two polymorphic forms can occur.Khodzhaeva, M.G.; Bugakov, Yu.V.; Ismailov, T.S.: Heat capacity and thermodynamic functions of ethyl cyanoacetate in Khim.-Farm. Zhur. 21 (1987) 760-762, DOI:10.1007/BF00872889.
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Xenon difluoride is a linear molecule with an Xe–F bond length of in the vapor stage, and 200 pm in the solid phase. The packing arrangement in solid shows that the fluorine atoms of neighbouring molecules avoid the equatorial region of each molecule. This agrees with the prediction of VSEPR theory, which predicts that there are 3 pairs of non-bonding electrons around the equatorial region of the xenon atom. At high pressures, novel, non- molecular forms of xenon difluoride can be obtained.
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There are also other interface categories, rarely used, including liquid-gas, solid-gas, and solid-solid. In a liquid- solid interface, polymerization begins at the interface, and results in a polymer attached to the surface of the solid phase. In a liquid-liquid interface with monomer dissolved in one phase, polymerization occurs on only one side of the interface, whereas in liquid-liquid interfaces with monomer dissolved in both phases, polymerization occurs on both sides. An interfacial polymerization reaction may proceed either stirred or unstirred.
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Filter assays are a solid phase ligand binding assay that use filters to measure the affinity between two molecules. In a filter binding assay, the filters are used to trap cell membranes by sucking the medium through them. This rapid method occurs at a fast speed in which filtration and a recovery can be achieved for the found fraction. Washing filters with a buffer removes residual unbound ligands and any other ligands present that are capable of being washed away from the binding sites.
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When the green powder is brought into water a yellow/orange solution is obtained from left over ammonium dichromate. Observations obtained using relatively high magnification microscopy during a kinetic study of the thermal decomposition of ammonium dichromate provided evidence that salt breakdown proceeds with the intervention of an intermediate liquid phase rather than a solid phase. The characteristic darkening of crystals as a consequence of the onset of decomposition can be ascribed to the dissociative loss of ammonia accompanied by progressive anion condensation to , , etc., ultimately yielding .
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Thermal-induced phase separation separates a homogenous polymer solution into a multi-phase system via thermodynamic changes. The procedure involves five steps: polymer dissolution, liquid-liquid or liquid-solid phase separation, polymer gelation, extraction of solvent from the gel with water, and freezing and freeze-drying under vacuum. Thermal- induced phase separation method is widely used to generate scaffolds for tissue regeneration. The homogenous polymer solution in the first step is thermodynamically unstable and tends to separate into polymer-rich and polymer-lean phases under appropriate temperature.
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The group, X at the C-terminus can be a normal or activated carboxylate such as an anhydride, acid-chloride, or NHS-ester. The second modification required is the addition of an azide to the N-terminus. Unlike the addition of the alkyne this can be done on the whole peptide, or solely on the N-terminal residue which is added to the rest of the oligopeptide by solid-phase peptide synthesis. The addition of the azide occurs by Cu(II)-catalyzed diazo transfer.
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Since the discovery of IgE in 1967, Phadia has pioneered the development of in vitro test systems for allergy (immunoglobulin E). These IgE tests have been followed by tests for IgG and IgA antibodies, as well as other analytes with applications in asthma, celiac disease and autoimmunity. In addition, the ImmunoCAP testing system has revolutionized the level of automation and speed which these tests are processed. Based on the high binding capacity and solid phase technology, ImmunoCAP tests are both highly sensitive and highly specific.
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One of the important functions of an FSL construct is that it can optimise the presentation of antigens, both on cell surfaces and solid-phase membranes. This optimisation is achieved primarily by the spacer, and secondarily by the lipid tail. In a typical immunoassay, the antigen is deposited directly onto the microplate surface and binds to the surface either in a random fashion, or in a preferred orientation depending on the residues present on the surface of this antigen. Usually this deposition process is uncontrolled.
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Usually, a set of individually designed oligonucleotides is made on automated solid-phase synthesizers, purified and then connected by specific annealing and standard ligation or polymerase reactions. To improve specificity of oligonucleotide annealing, the synthesis step relies on a set of thermostable DNA ligase and polymerase enzymes. To date, several methods for gene synthesis have been described, such as the ligation of phosphorylated overlapping oligonucleotides, the Fok I method and a modified form of ligase chain reaction for gene synthesis. Additionally, several PCR assembly approaches have been described.
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Otherwise, the separation of the resulting mixture of reaction products is virtually impossible.Weng C. Chan, Peter D. White: Fmoc Solid Phase Peptide Synthesis, S. 10–12. The technique was introduced in the field of peptide synthesis by Robert Bruce Merrifield in 1977. As a proof of concept orthogonal deprotection is demonstrated in a photochemical transesterification by trimethylsilyldiazomethane utilizing the kinetic isotope effect: :Orthogonal protection Application in Photochemistry Due to this effect the quantum yield for deprotection of the right-side ester group is reduced and it stays intact.
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Solid sorbents for carbon capture include a diverse range of porous, solid- phase materials, including mesoporous silicas, zeolites and metal-organic frameworks. These have the potential to function as more efficient alternatives to amine gas treating processes for selectively removing CO2 from large, stationary sources including power stations.A. H. Lu, S. Dai, Porous Materials for Carbon Dioxide Capture Springer, 2014. While the technology readiness level of solid adsorbents for carbon capture varies between the research and demonstration levels, solid adsorbents have been demonstrated to be commercially viable for life-support and cryogenic distillation applications.
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Once the DNA is free, it can be separated from all other cellular components. After the DNA has been separated in solution, the remaining cellular debris can then be removed from the solution and discarded, leaving only DNA. The most common methods of DNA extraction include organic extraction (also called phenol chloroform extraction), Chelex extraction, and solid phase extraction. Differential extraction is a modified version of extraction in which DNA from two different types of cells can be separated from each other before being purified from the solution.
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First, they must be reversible with conditions that do not affect the unprotected side chains. Second, the protecting group must be able to withstand the conditions of solid-phase synthesis. Third, the removal of the thiol protecting group must be such that it leaves intact other thiol protecting groups, if orthogonal protection is desired. That is, the removal of PG A should not affect PG B. Some of the thiol protecting groups commonly used include the acetamidomethyl (Acm), tert-butyl (But), 3-nitro-2-pyridine sulfenyl (NPYS), 2-pyridine-sulfenyl (Pyr), and trityl (Trt) groups.
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Solid fat index (SFI) is a measure of the percentage of fat in crystalline (solid) phase to total fat (the remainder being in liquid phase) across a temperature gradient. The SFI of a fat is measured using a dilatometer that measures the expansion of a fat as it is heated; density measurements are taken at a series of standardized temperature check points. The resulting SFI/temperature curve is related to melting qualities and flavor. For example, butter has a sharp SFI curve, indicating that it melts quickly and that it releases flavor quickly.
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In place of solvent gradient elution, thermoresponsive polymers allow the use of temperature gradients under purely aqueous isocratic conditions. The versatility of the system is controlled not only through changing temperature, but through the addition of modifying moieties that allow for a choice of enhanced hydrophobic interaction, or by introducing the prospect of electrostatic interaction. These developments have already introduced major improvements to the fields of hydrophobic interaction chromatography, size exclusion chromatography, ion exchange chromatography, and affinity chromatography separations as well as pseudo-solid phase extractions ("pseudo" because of phase transitions).
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At room temperature, strontium bromide adopts a crystal structure with a tetragonal unit cell and space group P4/n. This structure is referred to as α-SrBr2 and is isostructural with EuBr2 and USe2. Around 920 K (650 °C), α-SrBr2 undergoes a first-order solid-solid phase transition to a much less ordered phase, β-SrBr2, which adopts the cubic fluorite structure. The beta phase of strontium bromide has a much higher ionic conductivity of about 1 S cm−1, comparable to that of molten SrBr2, due to extensive disorder in the bromide sublattice.
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Changing concentrations of BPA can be harmful to the ecology of an ecosystem, as well as to humans if the plants are produced to be consumed. The amount of absorbed BPA on sediment was also seen to decrease with increases in temperature, as demonstrated by a study in 2006 with various plants from the XiangJiang River in Central-South China. In general, as temperature increases, the water solubility of a compound increases. Therefore, the amount of sorbate that enters the solid phase will lower at the equilibrium point.
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The use of ELISA offered routine diagnostic laboratories a quick, effective and sensitive method of screening for a wide range of potato plant viruses. Detection of pathogens using ELISA relies on the interaction between the antigen and specific antibodies and has become a popular and cost- effective means of routine detection. In an ELISA the solid phase can be coated with the sample of interest containing the antigen.Tijssen, P. (1985). Burdon, R.H.and Knippenberg, P.H. [ed], Laboratory techniques in biochemistry and molecular biology practice and theory of enzyme immunoassays, volume 15, Elsevier Science Publishers B.V., Amsterdam.
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This development led to the discovery of fullerenes in 1986 and carbon nanotubes a few years later. In science, a lot is known about properties of the gas phase; however, comparatively little is known about the condensed phases (the liquid phase and solid phase.) The study of clusters attempts to bridge this gap of knowledge by clustering atoms together and studying their characteristics. If enough atoms were clustered together, eventually one would obtain a liquid or solid. The study of atomic and molecular clusters also benefits the developing field of nanotechnology.
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Nanoparticles have a much greater surface to volume ratio than bulk materials. The increased surface to volume ratio means surface atoms have a much greater effect on chemical and physical properties of a nanoparticle. Surface atoms bind in the solid phase with less cohesive energy because they have fewer neighboring atoms in close proximity compared to atoms in the bulk of the solid. Each chemical bond an atom shares with a neighboring atom provides cohesive energy, so atoms with fewer bonds and neighboring atoms have lower cohesive energy.
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1173-1174 It is also possible that heavy elements, such as iron, simply sink beneath the surface, leaving only light nuclei like helium and hydrogen. If the surface temperature exceeds 106 kelvin (as in the case of a young pulsar), the surface should be fluid instead of the solid phase that might exist in cooler neutron stars (temperature <106 kelvin). The "atmosphere" of a neutron star is hypothesized to be at most several micrometers thick, and its dynamics are fully controlled by the neutron star's magnetic field. Below the atmosphere one encounters a solid "crust".
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Take for example proteins in water, which would be a liquid phase that is passed through a column. The column is commonly known as the solid phase since it is filled with porous synthetic particles that are of a particular charge. These porous particles are also referred to as beads, may be aminated (containing amino groups) or have metal ions in order to have a charge. The column can be prepared using porous polymers, for macromolecules over 100,000 the optimum size of the porous particle is about 1 μm2.
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The principle how SAF Microscopy works is as follows: A fluorescent specimen does not emit fluorescence isotropically when it comes close to a surface, but approximately 70% of the fluorescence emitted is directed into the solid phase. Here, the main part enters the solid body above the critical angle.J. Enderlein, T. Ruckstuhl, S. Seeger: Highly Efficient Optical Detection of Surface-Generated Fluorescence. Appl. Opt. 38 (4) 724-32 (1999) When the emitter is located just 200 nm above the surface, fluorescent light entering the solid body above the critical angle is decreased dramatically.
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This precluded the formation of oligonucleotides branched at the internucleosidic phosphate. The higher selectivity of the method allowed the use of more efficient coupling agents and catalysts, which dramatically reduced the length of the synthesis. The method, initially developed for the solution-phase synthesis, was also implemented on low-cross-linked "popcorn" polystyrene, and later on controlled pore glass (CPG, see "Solid support material" below), which initiated a massive research effort in solid-phase synthesis of oligonucleotides and eventually led to the automation of the oligonucleotide chain assembly.
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Also included is a small catalog of unsaturated soil hydraulic properties, as well as pedotransfer functions based on neural networks. Both HYDRUS models also consider various provisions for simulating non-equilibrium flow and transport. The flow equation for the latter purpose can consider dual-porosity-type flow with a fraction of the water content being mobile, and a fraction immobile. The transport equations additionally were modified to allow consideration of kinetic attachment/detachment processes of solutes to the solid phase, and hence of solutes having a finite size.
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The agitation is achieved by movement of the heterogeneous mass(liquid-solid phase),to the impeller. This is due to mechanical agitators, to the rotation of an impeller. The bulk can be composed of different substances and the aim of the operation is to blend it or to improve the efficiency of a reaction by a better contact between reactive product. Or the bulk is already blended and the aim of agitation is to increase a heat transfer or to maintain particles in suspension to avoid any deposit.
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All of the reactants associate with the polyleucine catalyst prior to reaction to form the hydroperoxide enolate intermediate. The catalyst orients the reactants and, even more significantly, the peroxide enolate intermediate by a series of hydrogen bonding interactions with the four N-terminal amino groups in the poly-leucine α-helix. While other models have been proposed,Berkessel, A.; Gasch, N.; Glaubitz, K.; Koch, C., "Highly enantioselective enone epoxidation catalyzed by short solid phase-bound peptides: Dominant role of peptide helicity". Org. Lett. 2001, 3 (24), 3839–3842.
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She brought in several new projects, including HIV/AIDS research. Nancy's team participated in a consortium, which sequenced the HIV genome structure. Nancy was instrumental in developing the first diagnostic assay to detect HIV infection by employing a peptide segment of HIV as the solid-phase antigen in the immunoassay. She was Director of Research at Centocor from 1982 to 1986. In 1986, the Changs moved to Houston, TX. Baylor College of Medicine in Houston offered Tse Wen a faculty position, and Nancy was able to obtain a position as well.
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In the +4 oxidation state, halotellurate anions are known, such as and . Halotellurium cations are also attested, including , found in . ;Oxocompounds A sample of tellurium dioxide powder Tellurium monoxide was first reported in 1883 as a black amorphous solid formed by the heat decomposition of in vacuum, disproportionating into tellurium dioxide, and elemental tellurium upon heating. Since then, however, existence in the solid phase is doubted and in dispute, although it is known as a vapor fragment; the black solid may be merely an equimolar mixture of elemental tellurium and tellurium dioxide.
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The weld is made by rotating the stud at high speed and forcing it onto the substrate causing friction which heats the stud tip and substrate surface. Metal at the interface between the stud and the substrate flows plastically under pressure, removing impurities from the metal surfaces, and a solid phase weld is formed. The rotation of the stud is then stopped but the force on the stud is maintained for a few seconds. The maximum temperatures reached during welding are much lower than the melting point of the metals.
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Sublimation is a direct phase transition from the solid phase to the gas phase, skipping the intermediate liquid phase. Because it does not involve the liquid phase, it is not a form of vaporization. The term vaporization has also been used in a colloquial or hyperbolic way to refer to the physical destruction of an object that is exposed to intense heat or explosive force, where the object is actually blasted into small pieces rather than literally converted to gaseous form. Examples of this usage include the "vaporization" of the uninhabited Marshall Island of Elugelab in the 1952 Ivy Mike thermonuclear test.
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Hence as long as the film is thin compared to the frequency interaction from the solid to the whole film is possible. But when d gets large compared to typical VUV frequencies the electronic structure of the film will be too slow to pass the high frequencies to the other end of the liquid phase. Thus this end of the liquid phase feels only a retarded van der Waals interaction with the solid phase. Hence the attraction between the liquid molecules themselves will predominate and they will start forming droplets instead of thickening the film further.
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Eh–pH (Pourbaix) diagrams are commonly used in mining and geology for assessment of the stability fields of minerals and dissolved species. Under the conditions where a mineral (solid) phase is predicted to be the most stable form of an element, these diagrams show that mineral. As the predicted results are all from thermodynamic (at equilibrium state) evaluations, these diagrams should be used with caution. Although the formation of a mineral or its dissolution may be predicted to occur under a set of conditions, the process may practically be negligible because its rate is too slow.
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Solid-state 900 MHz (21.1 T) NMR spectrometer at the Canadian National Ultrahigh-field NMR Facility for Solids A variety of physical circumstances do not allow molecules to be studied in solution, and at the same time not by other spectroscopic techniques to an atomic level, either. In solid-phase media, such as crystals, microcrystalline powders, gels, anisotropic solutions, etc., it is in particular the dipolar coupling and chemical shift anisotropy that become dominant to the behaviour of the nuclear spin systems. In conventional solution-state NMR spectroscopy, these additional interactions would lead to a significant broadening of spectral lines.
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Oxford University Press, Washington, DC, pp. 186-199. With their high reactivity and large surface area, nanoparticles may be effective sorbents to help concentrate target contaminants for solid-phase microextraction, particularly in the form of self-assembled monolayers on mesoporous supports. The mesoporous silica structure, made through a surfactant templated sol-gel process, gives these self-assembled monolayers high surface area and a rigid open pore structure. This material may be an effective sorbent for many targets, including heavy metals such as mercury, lead, and cadmium, chromate and arsenate, and radionuclides such as 99Tc, 137CS, uranium, and the actinides.
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The sintering of liquid-phase materials involves a fine- grained solid phase to create the needed capillary pressures proportional to its diameter, and the liquid concentration must also create the required capillary pressure within range, else the process ceases. The vitrification rate is dependent upon the pore size, the viscosity and amount of liquid phase present leading to the viscosity of the overall composition, and the surface tension. Temperature dependence for densification controls the process because at higher temperatures viscosity decreases and increases liquid content. Therefore, when changes to the composition and processing are made, it will affect the vitrification process.
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Fig.1 Energy gap versus gallium composition for GaInAs InGaAs has a lattice parameter that increases linearly with the concentration of InAs in the alloy. The liquid-solid phase diagram shows that during solidification from a solution containing GaAs and InAs, GaAs is taken up at a much higher rate than InAs, depleting the solution of GaAs. During growth from solution, the composition of first material to solidify is rich in GaAs while the last material to solidify is richer in InAs. This feature has been exploited to produce ingots of InGaAs with graded composition along the length of the ingot.
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When Merrifield was awarded the Nobel Prize in Chemistry in 1984 for the invention of solid phase peptide synthesis some, such as Daniel Rich of the American Chemical Society expressed the view that he was "surprised that Hirschmann didn't share the Nobel Prize". He was awarded the National Medal of Science in 2000 by President of the United States Bill Clinton. He was presented the award at a December 1, 2000, dinner by Dr. Neal Francis Lane, Assistant to the President for Science & Technology:The President's National Medal of Science: Recipient Details - Ralph F. Hirschmann, National Science Foundation. Accessed July 19, 2009.
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Rittmann and several colleagues were the first to define soluble microbial products (SMP), which comprise a wide range of soluble organic molecules that microorganisms release to their environment. With Dr. Chrysi Laspidou, Rittmann linked SMP to the solid-phase products generated by microorganisms, the extracellular polymeric substances (EPS); they created the “unified model” of SMP, EPS, and active biomass, and it has been expanded and applied to all types of microbiological processes. Being major sinks for electrons and carbon, SMP and EPS have profound impacts on the performance of environmental biotechnologies in terms of effluent quality and the composition of the biomass.
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The established method for the production of synthetic peptides in the lab is known as solid-phase peptide synthesis (SPPS). Pioneered by Robert Bruce Merrifield, SPPS allows the rapid assembly of a peptide chain through successive reactions of amino acid derivatives on an insoluble porous support. The solid support consists of small, polymeric resin beads functionalized with reactive groups (such as amine or hydroxyl groups) that link to the nascent peptide chain. Since the peptide remains covalently attached to the support throughout the synthesis, excess reagents and side products can be removed by washing and filtration.
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Phenol extraction is a processing technology used to prepare phenols as raw materials, compounds or additives for industrial wood processing and for chemical industries. Extraction can be performed using different solvents. There is a risk that polyphenol oxidase (PPO) degrades the phenolic content of the sample therefore there is a need to use PPO inhibitors like potassium dithionite (K2S2O4) or to perform experiment using liquid nitrogen or to boil the sample for a few seconds (blanching) to inactivate the enzyme. Further fractionation of the extract can be achieved using solid phase extraction columns, and may lead to isolation of individual compounds.
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Solid rockets use propellant in the solid phase, liquid fuel rockets use propellant in the liquid phase, gas fuel rockets use propellant in the gas phase, and hybrid rockets use a combination of solid and liquid or gaseous propellants. In the case of solid rocket motors, the fuel and oxidizer are combined when the motor is cast. Propellant combustion occurs inside the motor casing, which must contain the pressures developed. Solid rockets typically have higher thrust, less specific impulse, shorter burn times, and a higher mass than liquid rockets, and additionally cannot be stopped once lit.
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Other parameters that can be used to alter the order or time of retention are the carrier gas flow rate, column length and the temperature.Diagram of a gas chromatograph.In a GC analysis, a known volume of gaseous or liquid analyte is injected into the "entrance" (head) of the column, usually using a microsyringe (or, solid phase microextraction fibers, or a gas source switching system). As the carrier gas sweeps the analyte molecules through the column, this motion is inhibited by the adsorption of the analyte molecules either onto the column walls or onto packing materials in the column.
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An effective sample preparation protocol, usually involving either liquid-liquid extraction (LLE) or solid phase extraction (SPE) and frequently derivatisation can remove ion suppressing species from the sample matrix prior to analysis. These common approaches may also remove other interferences, such as isobaric species. Protein precipitation is another method that can be employed for small molecule analysis. Removal of all protein species from the sample matrix may be effective in some cases, although for many analytes, ion suppressing species are not of protein origin and so this technique is often used in conjunction with extraction and derivatisation.
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The CRMN was one of the groups developing tools and protocols for the structural and dynamic characterization of proteins in solid phase, including preparations of micro-crystalline samples, role of solvent, paramagnetic systems and sequential assignment, with a progressive introduction thanks to ultra-fast MAS of direct proton acquisition mimicking the sequences used for liquid NMR spectra. In collaboration with Martin Blackledge his team published some of the first ssNMR methods for the characterization of atom-specific dynamics in biosolids and its relation with solvent behaviour and function, providing detailed insight about the hierarchy of motions in proteins with the increase of temperature.
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Since then, a variety of small proteins (up to 200 residues) have been synthesized, including ubiquitin and other similar modifier proteins, hormone proteins, nitrophorin 4, S100A4 and cyclic proteins. C-terminal ketoacid monomers are pre-loaded on resin via a linker for Fmoc-SPPS (Fmoc-based solid phase peptide synthesis). Initial research utilised sulfur ylide linkers, but more recently the group developed acid- and photo-labile ketoacid monomers that can be loaded directly on Rink Amide resin. The most commonly used N-terminal hydroxylamine is the 5-oxaproline, which results in a homoserine residue after ligation and O-N rearrangement.
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The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Engvall and Perlmann in 1971. The assay uses a solid-phase type of enzyme immunoassay (EIA) to detect the presence of a ligand (commonly a protein) in a liquid sample using antibodies directed against the protein to be measured. ELISA has been used as a diagnostic tool in medicine, plant pathology, and biotechnology, as well as a quality control check in various industries. In the most simple form of an ELISA, antigens from the sample to be tested are attached to a surface.
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Olive oil begins to solidify (via liquid-solid phase separation) at around 4 °C, whereas winter temperatures in temperate countries can often be colder than 0 °C. In these conditions, olive oil begins to develop white, waxy clumps/spheres of solidified oil that sink to the bottom of the container. In crude or heavy oils, cloud point is synonymous with wax appearance temperature (WAT) and wax precipitation temperature (WPT). The cloud point of a nonionic surfactant or glycol solution is the temperature at which the mixture starts to phase- separate, and two phases appear, thus becoming cloudy.
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Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small bits of nucleic acids can be manufactured as single-stranded molecules with any user- specified sequence, and so are vital for artificial gene synthesis, polymerase chain reaction (PCR), DNA sequencing, molecular cloning and as molecular probes. In nature, oligonucleotides are usually found as small RNA molecules that function in the regulation of gene expression (e.g. microRNA), or are degradation intermediates derived from the breakdown of larger nucleic acid molecules.
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Chromatography column In analytical and organic chemistry, elution is the process of extracting one material from another by washing with a solvent; as in washing of loaded ion-exchange resins to remove captured ions. In a liquid chromatography experiment, for example, an analyte is generally adsorbed, or "bound to", an adsorbent in a liquid chromatography column. The adsorbent, a solid phase (stationary phase), is a powder which is coated onto a solid support. Based on an adsorbent's composition, it can have varying affinities to "hold" onto other molecules—forming a thin film on the surface of its particles.
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In these reviews he gives also a description and explanation of the chemical and corresponding biochemical results of the methylphosphotriester DNA, RNA and related systems. This contribution that is mainly based on the work at Eindhoven also consists of new insights in solid-phase synthesis, B-Z transition, and methyl transfer reactions connected with replicational and transcriptional silencing. Special attention is given to the effect of phosphate shielding on duplex stability. Models based on molecular mechanics calculations and recent density functional ab initio calculations support the impact of phosphate shielding at the various levels of stability of the DNA duplex.
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SRTXs are abundant in venoms, whereas ETs are present in a low concentration in mammals. Both, ETs and SRTXs are generated in vivo by proteolytic cleavage from larger precursors. They also can be produced by solid phase peptide synthesis and fold spontaneously in vitro in high yield into native tertiary structures with the correct disulfide bond pairing of cysteines. SRTXs complete cDNA sequence comprises 1948 base pairs (bp) coding for a pre-pro-polypeptide of 543 amino acids which starts with a methionine that initiates translation followed by a hydrophobic peptide characteristic of a signal sequence.
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It is hard to say something general about the soil thermal properties at a certain location because these are in a constant state of flux from diurnal and seasonal variations. Apart from the basic soil composition, which is constant at one location, soil thermal properties are strongly influenced by the soil volumetric water content, volume fraction of solids and volume fraction of air. Air is a poor thermal conductor and reduces the effectiveness of the solid and liquid phases to conduct heat. While the solid phase has the highest conductivity it is the variability of soil moisture that largely determines thermal conductivity.
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A NERVA solid-core design Solid core nuclear reactors have been fueled by compounds of uranium that exist in solid phase under the conditions encountered and undergo nuclear fission to release energy. Flight reactors must be lightweight and capable of tolerating extremely high temperatures, as the only coolant available is the working fluid/propellant. A nuclear solid core engine is the simplest design to construct and is the concept used on all tested NTRs. A solid core reactor's performance is ultimately limited by the material properties, including melting point, of the materials used in the nuclear fuel and reactor pressure vessel.
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A further complication is that many solids change their crystal structure to more compact arrangements at extremely high pressures (up to millions of bars, or hundreds of gigapascals). These are known as solid–solid phase transitions wherein latent heat is liberated as a crystal lattice changes to a more thermodynamically favorable, compact one. The above complexities make for rather cumbersome blanket statements regarding the internal energy in T = 0 substances. Regardless of pressure though, what can be said is that at absolute zero, all solids with a lowest-energy crystal lattice such those with a closest-packed arrangement (see Fig.
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The target is inserted into the vacuum chamber of the mass spectrometer and the desorption and ionisation of the polypeptide fragments is initiated by a pulsed laser beam which transfers high amounts of energy into the matrix molecules. The energy transfer is sufficient to promote the ionisation and transition of matrix molecules and peptides from the solid phase into the gas phase. The ions are accelerated in the electric field of the mass spectrometer and fly towards an ion detector where their arrival is detected as an electric signal. Their mass-to-charge ratio is proportional to their time of flight (TOF) in the drift tube and can be calculated accordingly.
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MSRR-1 (NASA) The Materials Science Laboratory (MSL) of the European Space Agency is a payload on board the International Space Station for materials science experiments in low gravity. It is installed in NASA's first Materials Science Research Rack which is placed in the Destiny laboratory on board the ISS. Its purpose is to process material samples in different ways: directional solidification of metals and alloys, crystal growth of semi-conducting materials, thermo-physical properties and diffusion experiments of alloys and glass-forming materials, and investigations on polymers and ceramics at the liquid-solid phase transition. MSL was built for ESA by EADS Astrium in Friedrichshafen, Germany.
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When a continuous rim of C-S-H completely envelops the external surface of the attacked siliceous aggregate, it behaves as a semi-permeable barrier and hinders the expulsion of the viscous sodium silicate while allowing the NaOH / KOH to diffuse from the hardened cement paste inside the aggregate. This selective barrier of C-S-H contributes to increase the hydraulic pressure inside the aggregate and aggravates the cracking process. It is the expansion of the aggregates which damages concrete in the alkali-silica reaction. Portlandite (Ca(OH)2) represents the main reserve of OH– anions in the solid phase as emphasized by Wang and Gillott (1991).
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This can repeat such that every water molecule is H-bonded with up to four other molecules, as shown in the figure (two through its two lone pairs, and two through its two hydrogen atoms). Hydrogen bonding strongly affects the crystal structure of ice, helping to create an open hexagonal lattice. The density of ice is less than the density of water at the same temperature; thus, the solid phase of water floats on the liquid, unlike most other substances. Liquid water's high boiling point is due to the high number of hydrogen bonds each molecule can form, relative to its low molecular mass.
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Unless signatures of causality manipulations were detected, Dolans concealed themselves on remote uninhabited planets and stayed in stasis, resembling a deflated balloon hull. In its active state, a Dolan became a reddish or black and outwardly almost featureless sphere of about 100 meters diameter. Its body consisted mainly of matrix tissue built from structural cells that could adapt to almost any function (including absorption of nutrients) and could undergo multiple rounds of local cell division whenever this was called for; therefore, few dedicated organs were required. Within minutes, this tissue could undergo a solid-phase transformation to harden its structure to a polycristalline steel- like quality.
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Peptoid nanosheets have a very high surface area, which can be readily functionalized to serve as a platform for sensing and templating.Olivier, G.K.; Cho, A.; Sanii, B.; Connolly, M.D.; Tran, H.; Zuckermann, R.N. "Antibody-mimetic peptoid nanosheets for molecular recognition" ACS Nano. 7, 9276-9386, (2013). Also, their hydrophobic interiors can accommodate hydrophobic small molecule cargos, which have been demonstrated by the sequestration of Nile red when this dye was injected into an aqueous solution of the peptoid nanosheets.Tran, H., Gael, S.L., Connolly, M.D., Zuckermann, R.N. “Solid-phase submonomer synthesis of peptoid polymers and their self-assemble into highly-ordered nanosheets” J. Vis. Exp.
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A large number of support staff operate the facility, aid users, and carry out research, the control room is staffed 24 hours a day, every day of the year. Instrument scientists oversee the running of each instrument and liaise with users, and other divisions provide sample environment, data analysis and computing expertise, maintain the accelerator, and run education programmes. ISIS is also one of the few neutron facilities to have a significant detector group that researches and develops new techniques for collecting data. Among the important and pioneering work carried out was the discovery of the structure of high-temperature superconductors and the solid phase of buckminster- fullerene.
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As revealed by X-ray crystallographic refinement, solid-phase magnesocene exhibits an average Mg-C and C-C bond distance of 2.30 Å and 1.39 Å, respectively, and the Cp rings adopt a staggered conformation (point group D5d). Gas-phase electron diffraction has shown similar bond lengths, albeit with the Cp rings in an eclipsed conformation (point group D5h). The nature of Mg-Cp bonding has been hotly contested as to whether the interaction is primarily ionic or covalent in character. Gas-phase electron diffraction measurements have been invoked to argue for a covalent model, while vibrational spectroscopy measurements have offered evidence for both.
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Tyc TE can also be used biomimetically in which it mimics the environment created by the TE domain with the substrate's PCP through use of a synthetic tether linked to a polyethylene glycol (PEG) amide resin. Use of this resin bound to a desired substrate with isolated TE can allow for catalytic release of the resin as well as macrocyclization of the substrate (See figure 6 ). Use of solid phase peptide synthesis (SPPS) allowed the incorporation of a diverse array of monomers into the peptide chain. Later studies used the high tolerance of Tyc TE in order to modify the peptide backbone post-synthetically.
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These anionic fullerene cages are very stable molecules and do not have the reactivity associated with ordinary empty fullerenes. They are stable in air up to very high temperatures (600 to 850 °C). The lack of reactivity in Diels- Alder reactions is utilised in a method to purify [C80]−6 compounds from a complex mixture of empty and partly filled fullerenes of different cage size. In this method Merrifield resin is modified as a cyclopentadienyl resin and used as a solid phase against a mobile phase containing the complex mixture in a column chromatography operation. Only very stable fullerenes such as [Sc3N]+6@[C80]−6 pass through the column unreacted.
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Single-crystal X-ray studies indicate that the PF5 has trigonal bipyramidal geometry. Thus it has two distinct types of P−F bonds (axial and equatorial): the length of an axial P−F bond is distinct from the equatorial P−F bond in the solid phase, but not the liquid or gas phases due to Pseudo Berry Rotation. Fluorine-19 NMR spectroscopy, even at temperatures as low as −100 °C, fails to distinguish the axial from the equatorial fluorine environments. The apparent equivalency arises from the low barrier for pseudorotation via the Berry mechanism, by which the axial and equatorial fluorine atoms rapidly exchange positions.
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The Genetic Design arranged with Dr Christian Birr (Max-Planck-Institute for Medical Research) a week before the event to convert his solid phase sequencer into the semi-automated synthesizer. The team led by Dr Alex Bonner and Rick Neves converted the unit and transported it to Darmstadt for the event and installed into the Biochemistry lab at the Technische Hochschule. As the system was semi-automatic, the user injected the next base to be added to the growing sequence during each cycle. The system worked well and produced a series of test tubes filled with bright red trityl color indicating complete coupling at each step.
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In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.. It is that temperature and pressure at which the sublimation curve, fusion curve and the vaporisation curve meet. For example, the triple point of mercury occurs at a temperature of and a pressure of 0.2 mPa. In addition to the triple point for solid, liquid, and gas phases, a triple point may involve more than one solid phase, for substances with multiple polymorphs. Helium-4 is a special case that presents a triple point involving two different fluid phases (lambda point).
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Most of the methodologies found in the literature to quantify EC use gas chromatography, using LLE and SPE as extraction techniques. Nevertheless, several efforts have also been done to develop new methodologies to determine EC without using long procedures and hard-working analyses, combining precision to high sensitivity. In this regard, headspace solid phase microextraction (HS-SPME) has been gaining great highlighting and alternative methodologies has been proposed using the most recent identification and quantification technology, such as gas chromatography with tandem mass spectrometry detection (GC–MS/MS) and two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC–ToFMS). Microextraction by packed sorbent (MEPS) is also feasible.
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As ionic potential is greater than this of , it exerts a greater Coulomb interaction with its neighboring anions in the solid phase, or with water molecules in solution. As a consequence, the lattice energy of magnesite () is higher than that of calcite () and therefore the solubility of is lower than that of because it requires more energy to separate the ions of opposite charge present in the crystal lattice. Similarly, in aqueous solution, the intermolecular forces (IMF) due to the ion-dipole interactions between and the immediately surrounding molecules are also stronger than for . The ion is hexahydrated in aqueous solution and presents an octahedral configuration.
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It is widely believed that there is no way to distinguish between poppy seeds and any other kind of opiate. However, a study published by the University of Connecticut's Department of Chemistry proposed that thebaine could be used as a marker of poppy seed consumption. They examined the urine of test subjects given 11 grams of poppy seeds, the urine of heroin users and clean urine spiked with thebaine, as a reference for GC- MS. They also tested street heroin, one morphine tablet and one codeine tablet. Urine specimens were screened by EMIT and confirmed for thebaine by GC-MS using a solid-phase extraction method.
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Above 0 °C, an H2O molecule that is in the liquid phase (liquid water) has a lower chemical potential than a water molecule that is in the solid phase (ice). When some of the ice melts, H2O molecules convert from solid to liquid where their chemical potential is lower, so the ice cubes shrink. Below 0 °C, the molecules in the ice phase have the lower chemical potential, so the ice cubes grow. At the temperature of the melting point, 0 °C, the chemical potentials in water and ice are the same; the ice cubes neither grow nor shrink, and the system is in equilibrium.
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In 1995 it was suggested that asteroseismological observations of pulsating white dwarfs yielded a potential test of the crystallization theory, and in 2004, observations were made that suggested approximately 90% of the mass of BPM 37093 had crystallized. Other work gives a crystallized mass fraction of between 32% and 82%. As a white dwarf core undergoes crystallization into a solid phase, latent heat is released which provides a source of thermal energy that delays its cooling. This effect was first confirmed in 2019 after the identification of a pile up in the cooling sequence of more than 15,000 white dwarfs observed with the Gaia satellite.
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The beauty of this method is that the identity of each product can be known simply by its location along the thread, and the corresponding biological activity is identified by Fourier transformation of fluorescence signals. Use of a traceless linker In most of the syntheses described here, it is necessary to attach and remove the starting reagent to/from a solid support. This can lead to the generation of a hydroxyl group, which can potentially affect the biological activity of a target compound. Ellman uses solid phase supports in a multi-step synthesis scheme to obtain 192 individual 1,4-benzodiazepine derivatives, which are well-known therapeutic agents.
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Originally part of the Pharmacia group of companies and an offshoot of the diagnostics division that developed out of Pfizer and Pharmacia & Upjohn (all Uppsala-based companies), Phadia was renamed in January 2006. The first steps towards the present Phadia AB were taken in the mid 1960s. Three scientists working at Uppsala University Hospital, Leif Wide, Rolf Axén and Jerker Porath, then presented their ideas to use Pharmacia's separation medium Sephadex as the solid phase in immunodiagnostics tests and proposed a collaboration with the company for the commercial development. Pharmacia's management decided to go for the project and established a special R&D; group for diagnostics products.
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Since most impurities will be more soluble in the liquid than in the solid phase during solidification, impurities will be "pushed" by the solidification front, causing much of the finished casting to have a lower concentration of impurities than the feedstock material, while the last solidified metal will be enriched with impurities. This last part of the metal can be scrapped or recycled. The suitability of directional solidification in removing a specific impurity from a certain metal depends on the partition coefficient of the impurity in the metal in question, as described by the Scheil equation. Directional solidification (in zone melting) is frequently employed as a purification step in the production of multicrystalline silicon for solar cells.
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Because there are no known naturally occurring deoxyribozymes, most known deoxyribozyme sequences have been discovered through a high- throughput in vitro selection technique, similar to SELEX. in vitro selection utilizes a "pool" of a large number of random DNA sequences (typically 1014–1015 unique strands) that can be screened for a specific catalytic activity. The pool is synthesized through solid phase synthesis such that each strand has two constant regions (primer binding sites for PCR amplification) flanking a random region of a certain length, typically 25–50 bases long. Thus the total number of unique strands, called the sequence space, is 4N where N denotes the number of bases in the random region.
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Researchers have synthesized many three-dimensional DNA complexes that each have the connectivity of a polyhedron, such as a cube or octahedron, meaning that the DNA duplexes trace the edges of a polyhedron with a DNA junction at each vertex.Overview: The earliest demonstrations of DNA polyhedra were very work-intensive, requiring multiple ligations and solid-phase synthesis steps to create catenated polyhedra.DNA polyhedra: Subsequent work yielded polyhedra whose synthesis was much easier. These include a DNA octahedron made from a long single strand designed to fold into the correct conformation,DNA polyhedra: and a tetrahedron that can be produced from four DNA strands in one step, pictured at the top of this article.
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It has seen a mayor development in last two decades and describes motion of the solid phase by the Discrete Element Method (DEM) on an individual particle scale and the remaining phases are treated by the Navier- Stokes equations. Thus, the method is recognized as an effective tool to investigate into the interaction between a particulate and fluid phase as reviewed by Yu and Xu, Feng and Yu and Deen et al. Based on the CCDM methodology the characteristics of spouted and fluidised beds are predicted by Gryczka et al. The theoretical foundation for the XDEM was developed in 1999 by Peters, who described incineration of a wooden moving bed on a forward acting grate.
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Dark green crystals of nickelocene, sublimed and freshly deposited on a cold finger Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state. Sublimation is an endothermic process that occurs at temperatures and pressures below a substance's triple point in its phase diagram, which corresponds to the lowest pressure at which the substance can exist as a liquid. The reverse process of sublimation is deposition or desublimation, in which a substance passes directly from a gas to a solid phase. Sublimation has also been used as a generic term to describe a solid-to-gas transition (sublimation) followed by a gas-to-solid transition (deposition).
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As an example, it was still taught as a useful analytic procedure in Cohen's Practical Organic Chemistry of 1910, in which the molar mass of naphthalene is determined using a Beckmann freezing apparatus. Freezing-point depression can also be used as a purity analysis tool when analyzed by differential scanning calorimetry. The results obtained are in mol%, but the method has its place, where other methods of analysis fail. This is also the same principle acting in the melting-point depression observed when the melting point of an impure solid mixture is measured with a melting-point apparatus since melting and freezing points both refer to the liquid-solid phase transition (albeit in different directions).
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As described above, the use of N-terminal and side chain protecting groups is essential during peptide synthesis to avoid undesirable side reactions, such as self-coupling of the activated amino acid leading to (polymerization). This would compete with the intended peptide coupling reaction, resulting in low yield or even complete failure to synthesize the desired peptide. Two principle orthogonal protecting group schemes exist for use in solid-phase peptide synthesis: so-called Boc/Bzl and Fmoc/tBu approaches. The Boc/Bzl strategy utilizes TFA-labile N-terminal Boc protection alongside side chain protection that is removed using anhydrous hydrogen fluoride during the final cleavage step (with simultaneous cleavage of the peptide from the solid support).
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By melting and solidifying at the phase change temperature (PCT), a PCM is capable of storing and releasing large amounts of energy compared to sensible heat storage. Heat is absorbed or released when the material changes from solid to liquid and vice versa or when the internal structure of the material changes; PCMs are accordingly referred to as latent heat storage (LHS) materials. There are two principal classes of phase change material: organic (carbon-containing) materials derived either from petroleum, from plants or from animals; and salt hydrates, which generally either use natural salts from the sea or from mineral deposits or are by-products of other processes. A third class is solid to solid phase change.
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HOF is explosive at room temperature, forming HF and O2: :2 HOF → 2 HF + O2 It was isolated in the pure form by passing F2 gas over ice at −40 °C, collecting the HOF gas, and condensing it: :F2 \+ H2O → HOF + HF The compound has been characterized in the solid phase by X-ray crystallography as a bent molecule with an angle of 101°. The O–F and O–H bond lengths are 144.2 and 96.4 picometres, respectively. The solid framework consists of chains with O–H···O linkages. The structure has also been analyzed in the gas phase, a state in which the H–O–F bond angle is slightly narrower (97.2°).
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Olfactory heritage is an aspect of cultural heritage concerning smells that are meaningful to a community due to their connections with significant places, practices, objects or traditions, and can therefore be considered part of the cultural legacy for future generations. . Research in olfactory heritage involves many disciplines such as chemistry, archaeology, conservation science, neuroscience, philosophy, psychology and history. Documentation olfactory heritage Researcher sampling the volatile organic compounds (VOCs) of a historic book using solid phase microextraction (SPME) at the Heritage Science Lab in University College London Institute for Sustainable Heritage. Olfactory heritage science is an emerging field of research, focused on the scientific techniques to analyse, document and preserve odours and the perspectives to understand their relevance.
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His lab is devoted towards synthesizing hydrophobic surfaces, diamond stationary phases for liquid chromatography and microfabricated TLC plates. Lindford works in surface modification and characterization, particularly in studying organic thin films (monolayer and polymer), modifying silicon, diamond, silicon oxide, gold, and polymers, surface patterning, surface organic chemistry, thin-film deposition with silanes, alkenes, thiols, and by sputtering. In his group they also undertake liquid chromatography (HPLC and TLC) and solid phase extraction (SPE), develop hydrophobic coatings for various materials, study materials for optical data storage, and perform surface analysis by XPS, ToF-SIMS, wetting, optical ellipsometry, and FTIR. His lab also performs chemometrics of mass spec data (PCA, MCR, cluster analysis, and PLS).
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William F. "Bill" DeGrado, Ph.D., is the Professor of Pharmaceutical Chemistry at the University of California, San Francisco (UCSF) and a member of the National Academy of Sciences. He received a B.S. (chemistry) from Kalamazoo College and a Ph.D. (Chemistry) from the University of Chicago in 1977 working with Emil T. Kaiser and F. Kezdy. His graduate work focused on the design of the oxime resin for solid-phase synthesis, which was used for synthesis of protected peptides and is still in use for various types of combinatorial chemistry today. He also used peptide design to demonstrate that melittin adopts an amphiphilic helical structure, which is responsible for its membrane-disrupting activity.
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A rod of semiconductor-grade polysilicon At the component level, polysilicon has long been used as the conducting gate material in MOSFET and CMOS processing technologies. For these technologies it is deposited using low-pressure chemical-vapour deposition (LPCVD) reactors at high temperatures and is usually heavily doped n-type or p-type. More recently, intrinsic and doped polysilicon is being used in large-area electronics as the active and/or doped layers in thin-film transistors. Although it can be deposited by LPCVD, plasma-enhanced chemical vapour deposition (PECVD), or solid-phase crystallization of amorphous silicon in certain processing regimes, these processes still require relatively high temperatures of at least 300 °C.
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Oligonucleotide synthesis is the chemical synthesis of relatively short fragments of nucleic acids with defined chemical structure (sequence). The technique is extremely useful in current laboratory practice because it provides a rapid and inexpensive access to custom-made oligonucleotides of the desired sequence. Whereas enzymes synthesize DNA and RNA only in a 5' to 3' direction, chemical oligonucleotide synthesis does not have this limitation, although it is most often carried out in the opposite, 3' to 5' direction. Currently, the process is implemented as solid-phase synthesis using phosphoramidite method and phosphoramidite building blocks derived from protected 2'-deoxynucleosides (dA, dC, dG, and T), ribonucleosides (A, C, G, and U), or chemically modified nucleosides, e.g.
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Scheme. 1. i: N-Chlorosuccinimide; Bn = -CH2Ph In the early 1950s, Alexander Todd’s group pioneered H-phosphonate and phosphate triester methods of oligonucleotide synthesis. The reaction of compounds 1 and 2 to form H-phosphonate diester 3 is an H-phosphonate coupling in solution while that of compounds 4 and 5 to give 6 is a phosphotriester coupling (see phosphotriester synthesis below). Scheme 2. Synthesis of oligonucleotides by the H-Phosphonate Method Thirty years later, this work inspired, independently, two research groups to adopt the H-phosphonate chemistry to the solid-phase synthesis using nucleoside H-phosphonate monoesters 7 as building blocks and pivaloyl chloride, 2,4,6-triisopropylbenzenesulfonyl chloride (TPS-Cl), and other compounds as activators.
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In solid-phase synthesis, an oligonucleotide being assembled is covalently bound, via its 3'-terminal hydroxy group, to a solid support material and remains attached to it over the entire course of the chain assembly. The solid support is contained in columns whose dimensions depend on the scale of synthesis and may vary between 0.05 mL and several liters. The overwhelming majority of oligonucleotides are synthesized on small scale ranging from 10 nmol to 1 μmol. More recently, high-throughput oligonucleotide synthesis where the solid support is contained in the wells of multi-well plates (most often, 96 or 384 wells per plate) became a method of choice for parallel synthesis of oligonucleotides on small scale.
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In the branch dedicated to solid state chemistry, Werner Urland et al. synthesized and characterized structurally, by X-Ray crystallography, several lanthanide-chalcogenide systems with unusual anionic structures, such as PrSe2, PrSe1.9−x, CeSe1.9−x NdSe1.9 or more complex compositions, such as chalcogenide-silicates like Nd2 SeSiO4 like M 4X 3 [Si2 O 7] (M = Ce - Er; X = S, Se) The crystal structures of prototypic chalcogenides of trivalent lanthanides, like Ln2Se3 (Ln=Sm, Tb, Ho) were resolved., treating also their polymorphic manifestations and the electronic structure. Other solid phase systems such as lanthanide aluminium halides, LnAl3X12 (with Ln = lanthanide trivalent ions in the La-Ho series and X= Cl, Br) were considered as synthetic and structural problems.
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The vapor-liquid critical point in a pressure-temperature phase diagram is at the high- temperature extreme of the liquid–gas phase boundary. (The dotted green line gives the anomalous behaviour of water.) Vapor refers to a gas phase at a temperature where the same substance can also exist in the liquid or solid state, below the critical temperature of the substance. (For example, water has a critical temperature of 374 °C (647 K), which is the highest temperature at which liquid water can exist.) If the vapor is in contact with a liquid or solid phase, the two phases will be in a state of equilibrium. The term gas refers to a compressible fluid phase.
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This pool of products is then split into three equal portions containing each of the three products, and then each of the three individual pools is then reacted with another unit of reagent B, C, or D, producing 9 unique compounds from the previous 3. This process is then repeated until the desired number of building blocks is added, generating many compounds. When synthesizing a library of compounds by a multi-step synthesis, efficient reaction methods must be employed, and if traditional purification methods are used after each reaction step, yields and efficiency will suffer. Solid-phase synthesis offers potential solutions to obviate the need for typical quenching and purification steps often used in synthetic chemistry.
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The ideal formula of monazite is [LREE(PO4)], the variation in composition is mainly due to the chemical substitutions of light rare earth elements (REE) in monazite by other elements. One of the common substitutions are the exchange between LREE with Th and Ca, and P with Si to form huttonite [Th(SiO4)] and brabantite [CaTh(PO4)2]. Since all three minerals share the same chemical structure, they are the three endmembers in their solid solution, meaning that they appear in a same solid phase where substitutions happen. It is important to note that the compositional zonation patterns may not be the same when we are considering different elements, and age zonation may have no relationship with compositional zonation at all.
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Nanodiamonds have the ability to self-assemble and a wide range of small molecules, proteins antibodies, therapeutics and nucleic acids can bind to its surface allow for drug delivery, protein- mimicking and surgical implants. Other potential biomedical applications are the use of nanodiamonds as a support for solid-phase peptide synthesis and as sorbents for detoxification and separation and fluorescent nanodiamonds for biomedical imaging. Nanodiamonds are capable of biocompatibility, the ability to carry a broad range of therapeutics, dispersibility in water and scalability and thee potential for targeted therapy all properties needed for a drug delivery platform. The small size, stable core, rich surface chemistry, ability to self-assemble and low cytotoxicity of nanodiamonds have led to suggestions that they could be used to mimic globular proteins.
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The ocean is the largest sink or reservoir of atmospheric carbon dioxide (CO2), continually taking in carbon from the air. This CO2 is then dissolved and reacts with water to form carbonic acid, which reacts further to generate carbonate (CO32−), bicarbonate (HCO3−), and hydrogen (H+) ions. The saturation state of seawater refers to how saturated (or unsaturated) the water is with these ions, and this determines if an organism will calcify or if the already calcified crystals will dissolve. The saturation state for calcium carbonate (CaCO3) can be determined using the equation: Ω = ([Ca2+][CO32−])/ Ksp Where the numerator denotes the concentrations of calcium ions to carbonate ions, and the denominator Ksp refers to the stoichiometric solubility product for the mineral (solid) phase of calcium carbonate.
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The principle is that the segregation coefficient k (the ratio of an impurity in the solid phase to that in the liquid phase) is usually less than one. Therefore, at the solid/liquid boundary, the impurity atoms will diffuse to the liquid region. Thus, by passing a crystal boule through a thin section of furnace very slowly, such that only a small region of the boule is molten at any time, the impurities will be segregated at the end of the crystal. Because of the lack of impurities in the leftover regions which solidify, the boule can grow as a perfect single crystal if a seed crystal is placed at the base to initiate a chosen direction of crystal growth.
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Between each step, the plate is typically washed with a mild detergent solution to remove any proteins or antibodies that are non-specifically bound. After the final wash step, the plate is developed by adding an enzymatic substrate to produce a visible signal, which indicates the quantity of antigen in the sample. Of note, ELISA can perform other forms of ligand binding assays instead of strictly "immuno" assays, though the name carried the original "immuno" because of the common use and history of development of this method. The technique essentially requires any ligating reagent that can be immobilized on the solid phase along with a detection reagent that will bind specifically and use an enzyme to generate a signal that can be properly quantified.
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Experimental and theoretical work on the perovskite/post-perovskite phase transition continues, while many important features of this phase transition remain ill-constrained. For example, the Clapeyron slope (characterized by the Clausius–Clapeyron relation) describing the increase in the pressure of the phase transition with increasing temperature is known to be relatively high in comparison to other solid-solid phase transitions in the Earth's mantle, however, the experimentally determined value varies from about 5 MPa/K to as high as 13 MPa/K. Ab initio calculations give a tighter range, between 7.5 MPa/K and 9.6 MPa/K, and are probably the most reliable estimates available today. The difference between experimental estimates arises primarily because different materials were used as pressure standards in Diamond Anvil Cell experiments.
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Redox flow batteries, and to a lesser extent hybrid flow batteries, have the advantages of flexible layout (due to separation of the power and energy components), long cycle life (because there are no solid-to-solid phase transitions), quick response times, no need for "equalisation" charging (the overcharging of a battery to ensure all cells have an equal charge) and no harmful emissions. Some types also offer easy state-of-charge determination (through voltage dependence on charge), low maintenance and tolerance to overcharge/overdischarge. They are safe and typically do not contain flammable electrolytes and due to the reason that electrolytes can be stored away from the power stack. These technical merits make redox flow batteries a well-suited option for large-scale energy storage.
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Schematic representation of the different stages and routes of the sol–gel technology In this chemical procedure, a "sol" (a colloidal solution) is formed that then gradually evolves towards the formation of a gel-like diphasic system containing both a liquid phase and solid phase whose morphologies range from discrete particles to continuous polymer networks. In the case of the colloid, the volume fraction of particles (or particle density) may be so low that a significant amount of fluid may need to be removed initially for the gel-like properties to be recognized. This can be accomplished in any number of ways. The simplest method is to allow time for sedimentation to occur, and then pour off the remaining liquid.
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Caliper has held a long- standing position in laboratory automation starting with the introduction of the world's first lab robotic system, the Zymark Zymate. To date, Caliper has a number of lab automation and liquid handling systems for the life sciences industry. In January 2009, the Zephyr Genomics Workstation was introduced which promises to deliver a benchtop solution for automating routine but critical processes for molecular biology such as nucleic acid purification, reaction setup and normalization. In addition to automating molecular biology, Caliper has many other robotic systems including the Zephyr SPE and RapidTrace SPE workstations to automate solid phase extraction and several liquid handling and plate management systems including the Sciclone ALH 3000 liquid handler and Twister II systems to automate drug discovery and development.
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In MCCs, there is no deconvolution required to determine which compounds are biologically- active because each synthesis in an array has only a single product, thus the identity of the compound should be unequivocally known. Example of a solid- phase supported dye to signal ligand binding In another array synthesis, Still generated a large library of oligopeptides by split synthesis. The drawback to making many thousands of compounds is that it is difficult to determine the structure of the formed compounds. Their solution is to use molecular tags, where a tiny amount (1 pmol/bead) of a dye is attached to the beads, and the identity of a certain bead can be determined by analyzing which tags are present on the bead.
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The earliest reported synthesis of a rotaxane in 1967 relied on the statistical probability that if two halves of a dumbbell-shaped molecule were reacted in the presence of a macrocycle that some small percentage would connect through the ring. To obtain a reasonable quantity of rotaxane, the macrocycle was attached to a solid-phase support and treated with both halves of the dumbbell 70 times and then severed from the support to give a 6% yield. However, the synthesis of rotaxanes has advanced significantly and efficient yields can be obtained by preorganizing the components utilizing hydrogen bonding, metal coordination, hydrophobic forces, covalent bonds, or coulombic interactions. The three most common strategies to synthesize rotaxane are "capping", "clipping", and "slipping", though others do exist.
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Where classical column chromatography uses a solid phase made by a packed bed, EBA uses particles in a fluidized state, ideally expanded by a factor of 2. Expanded bed adsorption is, however, different from fluidised bed chromatography in essentially two ways: one, the EBA resin contains particles of varying size and density which results in a gradient of particle size when expanded; and two, when the bed is in its expanded state, local loops are formed. Particles such as whole cells or cell debris, which would clog a packed bed column, readily pass through a fluidized bed. EBA can therefore be used on crude culture broths or slurries of broken cells, thereby bypassing initial clearing steps such as centrifugation and filtration, which is mandatory when packed beds are used.
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Fmoc carbamate is frequently used as a protecting group for amines, where the Fmoc group can be introduced by reacting the amine with fluorenylmethyloxycarbonyl chloride (Fmoc-Cl), e.g.: :Scheme showing addition of an Fmoc group to an amino acid The other common method for introducing the Fmoc group is through 9-fluorenylmethylsuccinimidyl carbonate (Fmoc-OSu), which may itself be obtained by the reaction of Fmoc-Cl with the dicyclohexylammonium salt of N-hydroxysuccinimide. It may be cleaved by bases, typically a solution of piperidine: :Mechanism of the deprotection of the Fmoc group with piperidine Fmoc protection has found significant use in solid phase peptide synthesis because its removal with piperidine solution does not disturb the acid labile linker between the peptide and the resin.J. Jones, Amino Acid and Peptide Synthesis, 2nd edn.
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For laboratory quantities, up to 40 are possible. In order to prepare larger peptides, individual fragments are first produced, purified, and then combined to the final molecule by liquid phase synthesis. Thus, for the production of Roche’s anti-AIDS drug Fuzeon (enfuvirtide), three fragments of 10–12 amino acids are first made by solid-phase synthesis and then linked together by liquid-phase synthesis. The preparation of the whole 35 amino acid peptide requires more than 130 individual steps. Microreactor Technology (MRT), making part of “process intensification”, is a relatively new tool that is being developed at several universities,Examples: Swiss Federal Institute of Technology (ETHZ), Switzerland; Massachusetts Institute of Technology (MIT), USA; Institut für Mikrotechnik (IMM), Germany; University of Washington (WU), USA; Micro-Chemical ProcessTechnology Research Association (MCPT), Japan.
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The four reactions in the Cu–Cl cycle are listed as follows:Rosen, M.A., Naterer, G.F., Sadhankar, R., Suppiah, S., "Nuclear-Based Hydrogen Production with a Thermochemical Copper-Chlorine Cycle and Supercritical Water Reactor", Canadian Hydrogen Association Workshop, Quebec, October 19 – 20, 2006. (PDF) .Lewis, M. and Masin, J., "An Assessment of the Efficiency of the Hybrid Copper-Chloride Thermochemical Cycle", Argonne National Laboratory, University of Chicago, 2 November 2005. (PDF). #2 Cu + 2 HCl(g) → 2 CuCl(l) + H2(g) (430–475 °C) #2 CuCl2 \+ H2O(g) → Cu2OCl2 \+ 2 HCl(g) (400 °C) #2 Cu2OCl2 → 4 CuCl + O2(g) (500 °C) #2 CuCl → CuCl2(aq) + Cu (ambient-temperature electrolysis) : : Net reaction: 2 H2O → 2 H2 \+ O2 : Legend: (g)—gas; (l)—liquid; (aq)—aqueous solution; the balance of the species are in a solid phase.
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According to the formal rules for naming inorganic compounds, the name for is aluminium acetate, though more formal names like aluminium(III) acetate and aluminium ethanoate are acceptable. The use of the "tri" multiplying prefix in the name aluminium triacetate, while not technically required, is regularly used to avoid potential confusion with related compounds with hydroxo ligands. Basic aluminium diacetate, formally hydroxyaluminium diacetate (CAS RN 142-03-0), has composition with one hydroxo ligand in place of an acetate ligand, and dibasic aluminium monoacetate, formally dihydroxyaluminium acetate (CAS RN 7360-44-3), has composition with only one acetate ligand. These three compounds are distinct in the solid phase but are usually treated as a group and described collectively as aluminium acetate in solution, due to the triacetate hydrolyzing to a mixture which includes the other two forms.
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In other words, as it is sometimes possible to fight fire with fire, it is also feasible to combat the ASR reaction by itself. A prompt reaction initiated at the early stage of concrete hardening on very fine silica particles will help to suppress a slow and delayed reaction with larger siliceous aggregates on the long term. Following the same principle, the fabrication of low-pH cement also implies the addition of finely divided pozzolanic materials rich in silicic acid to the concrete mix to decrease its alkalinity. Beside initially lowering the pH value of the concrete pore water, the main working mechanism of silica fume addition is to consume portlandite (the reservoir of hydroxyde (OH-) in the solid phase) and to decrease the porosity of the hardened cement paste by the formation of calcium silicate hydrates (C-S-H).
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Codeine is the most widely used opiate in the world, and is one of the most commonly used drugs overall according to numerous reports by organizations including the World Health Organization and its League of Nations predecessor agency. It is one of the most effective orally administered opioid analgesics and has a wide safety margin. Its strength ranges from 8% to 12% of morphine in most people; differences in metabolism can change this figure as can other medications, depending on its route of administration. While codeine can be directly extracted from opium, its original source, most codeine is synthesized from the much more abundant morphine through the process of O-methylation, through a process first completed in the late 20th century by Robert C. Corcoran and Junning Ma.Corcoran, R. C.; Ma, J. Solid-phase synthesis of codeine from morphine.
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Polar ice cap on Mars, seen by the Hubble Telescope A polar ice cap or polar cap is a high-latitude region of a planet, dwarf planet, or natural satellite that is covered in ice.The National Snow and Ice Data Center Glossary There are no requirements with respect to size or composition for a body of ice to be termed a polar ice cap, nor any geological requirement for it to be over land, but only that it must be a body of solid phase matter in the polar region. This causes the term "polar ice cap" to be something of a misnomer, as the term ice cap itself is applied more narrowly to bodies that are over land, and cover less than 50,000 km2: larger bodies are referred to as ice sheets. The composition of the ice will vary.
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The concerns raised by the toxicological aspects of EC together with the low concentration levels (µg/L) found in wines, as well as the occurrence of interferences on detection, has motivated several researchers to develop new methods to determine it in wines. Several extraction and chromatographic techniques have been used, including continuous liquid–liquid extraction (LLE) with Soxhlet apparatus, derivatization with 9-xanthydrol followed by high- pressure liquid chromatography (HPLC) with fluorescence detection and even LLE after derivatization, followed by gas chromatography coupled with mass spectrometry detection (GC–MS). On the other hand, the reference method set by the International Organization of Vine and Wine (OIV) uses solid phase extraction (SPE) preceding GC–MS quantification. Other methods also make use of SPE, but use gas chromatography with mass spectrometry (MDGC/MS) and liquid chromatography with tandem mass spectrometry (LC–MS/MS) for detection.
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A frit compression system for casting buckypaper An alternative casting method was developed in 2008 to produce buckypaper that did not require the use of surfactants or the acid oxidation of carbon nanotubes in order to obtain high-purity buckypaper for biomedical applications. The frit-compression system was adapted from a Solid phase extraction (SPE) column, where a suspension of carbon nanotubes is squeezed between two polypropylene frits (70 micrometre pore diameter) inside a syringe column. The pore structure of the frit allows a rapid exit of the solvent leaving the carbon nanotubes to be pressed together. The presence of the solvent controls the interaction between the tubes allowing the formation of tube-tube junctions; its surface tension directly affects the overlap of adjoining nanotubes thus gaining control over the porosity and pore diameter distribution of buckypaper.
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The unsolvated hydron (a completely free or "naked" hydrogen atomic nucleus) does not exist in the condensed (liquid or solid) phase. Although superacids are sometimes said owe their extraordinary hydron-donating power to the presence of "free hydrons", such a statement is highly misleading: even for a source of "free hydrons" like , one of the superacidic cations present in the superacid fluoroantimonic acid (HF:SbF5), detachment of a free still comes at an enormous energetic penalty on the order of several hundred kcal/mol. This effectively rules out the possibility of the free hydron being present in solution, even as a fleeting intermediate. For this reason, in liquid strong acids, hydrons are believed to diffuse by sequential transfer from one molecule to the next along a network of hydrogen bonds through what is known as the Grotthuss mechanism.
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A multi-anvil press, or anvil press is a type of device related to a machine press that is used to create extraordinarily high pressures within a small volume. They are used in materials science and geology for the synthesis and study the different phases of materials under extreme pressure, as well as for the industrial production of valuable minerals, especially synthetic diamonds, as they mimic the pressures and temperatures that exist deep in the Earth. These instruments allow the simultaneous compression and heating of millimeter size solid phase samples such as rocks, minerals, ceramics, glasses, composite materials, or metals and are capable of reaching pressures above 25 GPa and temperatures exceeding 2,500 °C. This allows mineral physicists and petrologists studying the Earth's interior to experimentally reproduce the conditions found throughout the lithosphere and upper mantle, a region that spans the near surface to a depth of 700 km.
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He went to the California Institute of Technology to study under John Gamble Kirkwood for his PhD in 1948 and worked for the investigation of phase transitions in hard-sphere gas with Stan Frankel, where he got the idea to use the Monte Carlo method. After he finished at Caltech in 1952, he went to Berkeley and worked part-time at Berkeley to teach chemistry and part-time as a consultant under suggestion of Edward Teller in the nuclear weapons program for the Lawrence Livermore National Laboratory to help with the equations of state. In collaboration with Thomas Everett Wainwright, he developed techniques for molecular dynamics simulation in the mid-1950s, including the liquid-solid phase transition for hard sphere and the velocity autocorrelations function decay in liquids. In the late 1950s, together, they began conducting computer simulations of idealized molecular dynamics of 2D hard spheres to investigate transitions between solids, liquids and gasses.
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Kerala University A. Ajayaghosh, born on 30 July 1962 in Kollam in the south Indian state of Kerala, graduated in science from the University of Kerala and completed his master's degree from the same university in 1984. Subsequently, working under the guidance of V. N. Rajasekharan Pillai, he secured a PhD from University of Calicut in 1989; his thesis was based on Solid-phase Peptide Synthesis. His career started in 1988 at the National Institute for Interdisciplinary Science and Technology (NIIST), then known as Regional Research Laboratory, of the Council of Scientific and Industrial Research, as a Scientist (Grade-C) and held various grades before reaching the position of a Scientist Grade-H and the head of the Photosciences and Photonics Group of NIIST in 2010. He is the director of the Institute since 2015 and holds the additional responsibility as the Dean of Chemical Sciences, Academy of Scientific and Innovative Research (AcSIR) New Delhi.
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SPE is a method of chromatography, except in the broadest, simplest sense. It is an extractive technique, a solid-liquid extractive technique—taking advantage of large differences in the Keq, or equilibrium constant, of mixture components between the solid phase and the mobile phase resulting, for a well-designed and executed separation, in a bulk separation of one or more of the mixture components so that it is significantly enriched as a result of the rapid extractive procedure. Granted many of the adsorbents/materials are the same as in chromatographic methods, and when these materials are packed into long columns—such that the number of theoretical plates increases by orders of magnitude as a result—the same materials result in chromatographic separations of components with even small difference is their Keq between phases. Even so, grey line that it might be that divides SPE and chrom, the distinctives are clear enough to say that SPE is an extractive technique, with theory, procedures, and aims separate from chromatography, and so with a unique niche in modern chemical science.
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An investigator for this study, Professor Moussa, generalized from its findings in a video interview and stated that pure C60 is not toxic. When considering toxicological data, care must be taken to distinguish as necessary between what are normally referred to as fullerenes: (C60, C70, ...); fullerene derivatives: C60 or other fullerenes with covalently bonded chemical groups; fullerene complexes (e.g., water-solubilized with surfactants, such as C60-PVP; host–guest complexes, such as with cyclodextrin), where the fullerene is supermolecular bound to another molecule; C60 nanoparticles, which are extended solid-phase aggregates of C60 crystallites; and nanotubes, which are generally much larger (in terms of molecular weight and size) molecules, and are different in shape to the spheroidal fullerenes C60 and C70, as well as having different chemical and physical properties. The molecules above are all fullerenes (close-caged all-carbon molecules) but it is unreliable to extrapolate results from C60 to nanotubes or vice versa, as they range from insoluble materials in either hydrophilic or lipophilic media, to hydrophilic, lipophilic, or even amphiphilic molecules, and with other varying physical and chemical properties.
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On 25 September 2009, ISRO announced that the MIP had discovered water on the Moon just before impact. This announcement was made after the discovery of water was announced on 24 September 2009 by Science magazine by the NASA payload Moon Mineralogy Mapper carried on board Chandrayaan-1. MIP discovered water on the Moon before NASA's Moon Mineralogy Mapper, the announcement of this discovery was not made until NASA confirmed it. This gave the answer to the millennia-old question whether there is water on or in Earth's moon when it led to the discovery of water in its vapour phase by the CHACE (CHandra's Altitudinal Composition Explorer) payload on board the Moon Impact Probe (MIP) and complementarily in its solid phase by the Moon Mineralogy Mapper (M3) payload on board the main orbiter in the Chandrayaan I mission. This ‘discovery-class-of-finding’ by CHACE was achieved by direct in situ measurement of the lunar atmosphere during the descend journey of the MIP to the Lunar South Pole, while M3 discovered water in ice form by remote sensing techniques.
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Broad screening and identification of β-agonists in feed and animal body fluid and tissues using ultra-high performance liquid chromatography-quadrupole-orbitrap high resolution mass spectrometry combined with spectra library search • Tingting Lia, 1, • Jingjing Caob, 1, • Zhen Lib, • Xian Wanga, • Pingli Hea, Broad screening and identification of β-agonists in feed, serum, urine, muscle and liver samples was achieved in a quick and highly sensitive manner using ultra high performance liquid chromatography- quadrupole-orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) combined with a spectra library search. Solid-phase extraction technology was employed for sample purification and enrichment. After extraction and purification, the samples were analyzed using a Q-Orbitrap high-resolution mass spectrometer under full-scan and data-dependent MS/MS mode. The acquired mass spectra were compared with an in-house library (compound library and MS/MS mass spectral library) built with TraceFinder Software which contained the M/Z of the precursor ion, chemical formula, retention time, character fragment ions and the entire MS/MS spectra of 32 β-agonist standards.
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In Grenoble, he set up in 1959 at the master level a new syllabus in general geophysics which will flourish in the 1960s when the Earth's sciences will be refounded by the plate tectonics "theory". Two articles published in 1969 and 1970 on the modelling of convection within the Earth's mantle showed him, with Claude Allègre, Xavier Le Pichon and Dan McKenzie, in the very closed circle of European scientists at the leading edge of the new theory. He was the first to notice that the viscosity of the asthenosphere, due to partial melting (of the order of one percent), is analogous to what happens in so-called "temperate glaciers" where ice is also partially melted in the same order of magnitude, with the coexistence of a liquid phase and a solid phase. He also modelled the postglacial rebound of the lithosphere as observed in Fennoscandia or Canada following the disappearance of Quaternary ice caps, which allowed him to infer the mechanical properties of the Earth's mantle, its rheology and its viscosity.
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Historically the solid-phase support for immunoprecipitation used by the majority of scientists has been highly- porous agarose beads (also known as agarose resins or slurries). The advantage of this technology is a very high potential binding capacity, as virtually the entire sponge-like structure of the agarose particle (50 to 150μm in size) is available for binding antibodies (which will in turn bind the target proteins) and the use of standard laboratory equipment for all aspects of the IP protocol without the need for any specialized equipment. The advantage of an extremely high binding capacity must be carefully balanced with the quantity of antibody that the researcher is prepared to use to coat the agarose beads. Because antibodies can be a cost-limiting factor, it is best to calculate backward from the amount of protein that needs to be captured (depending upon the analysis to be performed downstream), to the amount of antibody that is required to bind that quantity of protein (with a small excess added in order to account for inefficiencies of the system), and back still further to the quantity of agarose that is needed to bind that particular quantity of antibody.
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Mayer played a pivotal role in the application of particle detectors to the fledgling field of ion beam analysis (often referred to as Rutherford Backscattering Spectrometry or RBS) and the development of this field into a major analytical tool. He went on to define many of the advances in thin film science of the 1970s and 80s, including thin film reactions and kinetics (especially of metal silicides), solid phase regrowth of semiconductors, ion beam mixing for the formation of metastable alloys, implantation disorder and impurity location in semiconductors, and the study of thin dielectric films. In the rapid surge of industrial interest in ion implantation of Si, starting around 1965, Mayer and his coworkers used ion channeling to understand defect production during dopant ion implantation into Si, the recovery of this damage, and the activation of dopants during subsequent anneals, thereby making ion implantation a viable tool for the production of integrated circuits. In 1967, he was chosen by Academic Press to author the first monograph on Ion Implantation of Semiconductors and by 1970 ion implantation first began being used in the commercial production of integrated circuits.
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As part of the post- September 11 drive towards increased capability in homeland security and public health preparedness, traditional GC-MS units with transmission quadrupole mass spectrometers, as well as those with cylindrical ion trap (CIT-MS) and toroidal ion trap (T-ITMS) mass spectrometers have been modified for field portability and near real-time detection of chemical warfare agents (CWA) such as sarin, soman, and VX. These complex and large GC-MS systems have been modified and configured with resistively heated low thermal mass (LTM) gas chromatographs that reduce analysis time to less than ten percent of the time required in traditional laboratory systems. Additionally, the systems are smaller, and more mobile, including units that are mounted in mobile analytical laboratories (MAL), such as those used by the United States Marine Corps Chemical and Biological Incident Response Force MAL and other similar laboratories, and systems that are hand-carried by two-person teams or individuals, much ado to the smaller mass detectors. Depending on the system, the analytes can be introduced via liquid injection, desorbed from sorbent tubes through a thermal desorption process, or with solid-phase micro extraction (SPME).
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