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In low and middle income countries, foods fortified with vitamin D are "practically nonexistent." Most people in the world depend on the sun to get vitamin D, [31] and elderly populations in low UVB countries experience higher rates of cancer. [32] There are not many foods that naturally have vitamin D. [33] Examples are cod liver oil and oily ...
Melanin is a chromophore that exists in the human epidermal layer of skin responsible for protection from harmful UV radiation. When melanocytes are stimulated by solar radiation, melanin is produced. [7] Melanin is one of the major absorbers of light in some biological tissue (although its contribution is smaller than other components).
Micrograph of paper autofluorescing under ultraviolet illumination. The individual fibres in this sample are around 10 μm in diameter.. Autofluorescence is the natural fluorescence of biological structures such as mitochondria and lysosomes, in contrast to fluorescence originating from artificially added fluorescent markers (fluorophores).
Light therapy, also called phototherapy or bright light therapy is the exposure to direct sunlight or artificial light at controlled wavelengths in order to treat a variety of medical disorders, including seasonal affective disorder (SAD), circadian rhythm sleep-wake disorders, cancers, neonatal jaundice, and skin wound infections.
Pathogen reduction using riboflavin and UV light is a method by which infectious pathogens in blood for transfusion are inactivated by adding riboflavin and irradiating with UV light. [ 1 ] [ 2 ] [ 3 ] This method reduces the infectious levels of disease-causing agents that may be found in donated blood components, while still maintaining good ...
The TLVs for the 222 nm UV-C wavelength (peak emissions from KrCl excimer lamps), following the 2022 revision, are now 161 mJ/cm 2 for eye exposure and 479 mJ/cm 2 for skin exposure over an eight-hour period. [93] For the 254 nm UV wavelength, the updated exposure limit is now set at 6 mJ/cm 2 for eyes and 10 mJ/cm 2 for skin. [93]
Blood irradiation therapy is an alternative medical procedure in which the blood is exposed to low-level light (often laser light) for therapeutic reasons. [1] The practice was originally developed in the United States, [1] but most recent research on it has been conducted in Germany (by UV lamps) and in Russia (in all variants).
He named them "mitogenetic rays" because his experiments convinced him that they had a stimulating effect on cell division. [23] In the 1970s Fritz-Albert Popp and his research group at the University of Marburg showed that the spectral distribution of the emission fell over a wide range of wavelengths, from 200 to 750 nm. [24]