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Chemistry and Isotopes of Iodine
Published in Erwin Regoeczi, Iodine-Labeled Plasma Proteins, 2019
Data regarding the solubility of iodine in metal halides are found in Section I.B.2.C. Of some other solvents in common use, 100-g quantities dissolve the following approximate amounts of iodine: CC14, 0.7 g (0°C), 2.6 g (35°C); CHC13, 1.2 g (0°C), 2.6 g (20°C); CS2, 7.8 g (0°C), 14.6 g (20°C); ethanol, 16.1 g (8°C), 26.6 g (24°C).
UV Reflectance Photography
Published in Adrian Davies, Digital Ultraviolet and Infrared Photography, 2017
Metal halide lamps use various gases in a mercury discharge source to produce a regenerative cycle, similar to the quartz halogen type of bulb, but with increased and specific spectral output. A popular example for UV and multispectral photography is the EyeColor Arc bulb (M770D). This lamp needs to be run from a ballast and will need wiring together. The wiring is fairly straightforward, but do ask an electrician if you’re not completely comfortable doing that.
Systemic and Topical PUVA Therapy
Published in John Y. M. Koo, Ethan C. Levin, Argentina Leon, Jashin J. Wu, Alice B. Gottlieb, Moderate to Severe Psoriasis, 2014
Warwick L. Morison, Elisabeth G. Richard
Photobiology Psoralens must absorb photons in order to photosensitize; they must, therefore, be exposed to a source of radiation that emits a waveband that includes their absorption spectrum. Early studies suggested that the peak of the action spectrum for psoralen photosensitization was between 340 and 380 nm, which led to the use of fluorescent bulbs with a peak emission of approximately 355–365 nm. A more recent work [8] indicates that the peak of the spectrum is between 320 and 340 nm. Because the same fluorescent bulbs have good emission at these shorter wavelengths, they continue to be the most commonly used PUVA lamps. These fluorescent bulbs are usually placed in a cylindrical chamber for whole-body exposure or in a specialized apparatus for hand and foot treatment. Banks of metal halide lamps are also used for whole-body treatment, and single lamps can be used for treating localized disease. Other sources of UVA radiation should not be used for PUVA therapy at this time because the cutaneous responses to them in combination with psoralens have not been determined or clinically evaluated. The sun is not a safe source of UVA radiation in combination with methoxsalen because severe phototoxic reactions are common, even when sophisticated radiometry is used [9].
The loss of ecosystem-services emerging from artificial light at night
Published in Chronobiology International, 2019
Haim Abraham, David M. Scantlebury, Abed E. Zubidat
The adverse effect of light pollution needs to be avoided where possible and to be minimized to acceptable level where it cannot be entirely avoided. Previously, the spectra of common types of lamps for outdoor illumination were evaluated in relation to melatonin suppression (Falchi et al. 2011). In this study, a clear association was detected between the pollution level and the spectral composition of the lamps, with the more “environmentally friendly” being low pressure sodium, followed by high pressure sodium. Conversely, the strong blue emission lamps such as Metal Halide and white LEDs were the most significant source of light pollution (Falchi et al. 2011). Therefore, developing an “environmentally friendly” lighting technology with no blue emission is the first step in reducing the adverse impacts of light pollution on health and environment. As red lights present the least power to induce circadian disruption (Wright and Lack 2001; Wright et al. 2004), developing red LED lamps would be of a great interest regarding light pollution as such illumination may offer the power and energy efficient characteristics of the LED technology, but without blue emission at the SWL end of the visual spectrum. Furthermore, behavioural changes such as avoiding over lighting, turning off lights when they are not needed, and limiting the use of SWL-blue light, can also contribute to minimizing the adverse impact of light pollution (Falchi et al. 2011).
Evaluation of xenon, light-emitting diode (LED) and halogen light toxicity on cultured retinal pigment epithelial cells
Published in Cutaneous and Ocular Toxicology, 2019
Taha Sezer, Muhammed Altinisik, Eray Metin Guler, Abdurrahim Kocyigit, Hakan Ozdemir, Arif Koytak
The use of endoillumination in vitreoretinal surgery dates back to the 1970s13. As vitreoretinal surgery has progressed, the instruments used to illuminate the fundus during surgery have also become more advanced. The first of these innovations were halogen and metal halide lamps, followed by trials of illuminated infusion systems, illuminated trocar systems and illuminated surgical instruments. When these did not yield the desired output, xenon lights that provide brighter illumination came into use. The most recent development in this process is the use of LEDs in vitreoretinal surgical devices instead of halogen and xenon lights due to their better durability, lower power consumption, and heat production and adjustable wavelength14,15.
Advances in the tools and techniques of vitreoretinal surgery
Published in Expert Review of Ophthalmology, 2020
Ashish Markan, Aman Kumar, Jayesh Vira, Vishali Gupta, Aniruddha Agarwal
Conventionally halogen or metal halide light sources were used, but these sources caused decreased illumination with smaller gauge light probes by 40–50%. This required the use of high power sources like xenon and mercury vapor sources for small gauge endoilluminators. Newer light emitting diode (LED) light sources are long-lasting and provide higher illumination. Newer light probes have wide cone angles making peripheral viewing easier [27].