It's been over three years since Lizzo released an LP. Thank you, Lizzo, for kicking off 2019 in the most fluorescent way possible.
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But this weekend, the star out-Kylied herself with a shade that she's never worn before: the most fluorescent shade of neon yellow we've seen yet.
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Broad-spectrum blue light (for example, including cyan wavelengths, such as in natural light or most fluorescent lights) is essential to wakefulness. Because it stimulates melanopsin receptors in the eye. This suppresses daytime melatonin, enabling wakefulness. Working in blue-free light (aka yellow light) for long periods of time disrupts circadian patterns because there is no melatonin suppression during the day, and reduced melatonin rebound at night.
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Absorption spectrum of ethidium bromide As with most fluorescent compounds, ethidium bromide is aromatic. Its core heterocyclic moiety is generically known as a phenanthridine, an isomer of which is the fluorescent dye acridine. Absorption maxima of EtBr in aqueous solution are at 210 nm and 285 nm, which correspond to ultraviolet light. As a result of this excitation, EtBr emits orange light with wavelength 605 nm.
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A cold-cathode fluorescent lamp from an emergency-exit sign. Operating at a much higher voltage than other fluorescents, the lamp produces a low-amperage glow discharge rather than an arc, similar to a neon light. Without direct connection to line voltage, current is limited by the transformer alone, negating the need for a ballast. Most fluorescent lamps use electrodes that emit electrons into the tube by heat.
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Most fluorescent DNA dyes (one of exceptions is Hoechst 33342) are not plasma membrane permeant, that is, unable to pass through an intact cell membrane. Permeabilisation is therefore crucial for the success of the next step, the staining of the cells. Prior to (or during the staining step) the cells are often treated with RNase A to remove RNAs. This is important because certain dyes that stain DNA will also stain RNA, thus creating artefacts that would distort the results.
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Compact fluorescent lamps (CFL) have been used more frequently as time has improved the quality of these lamps. These lamps have been used on municipal walkways and street lighting though they are still rare at this time. Improvements in reliability still need to be made. Some issues with them are limited lumen output, high heat build up in the self-contained ballast, low life/burnout due to frequent cycling (on/off) of the lamp, and the problem where most fluorescent sources become dimmer in cold weather (or fail to start at all).
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The outer bulb may be clear or coated with a phosphor; in either case, the outer bulb provides thermal insulation, protection from the ultraviolet radiation the light produces, and a convenient mounting for the fused quartz arc tube. Mercury vapor lamps are more energy efficient than incandescent and most fluorescent lights, with luminous efficacies of 35 to 65 lumens/watt. Their other advantages are a long bulb lifetime in the range of 24,000 hours and a high intensity, clear white light output. For these reasons, they are used for large area overhead lighting, such as in factories, warehouses, and sports arenas as well as for streetlights.
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