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Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight , and constitutes about 10% of the total electromagnetic radiation output from the Sun.
Effects of UV-radiation at high latitudes, where snow stays on the ground into early summer and the sun then remains at a low position even at its zenith, have been reviewed by Meyer-Rochow. [15] UV map . Exposure to ultraviolet radiation from the sun is a source of vitamin D.
Ultraviolet radiation is known to suppress the immune system and reduce inflammatory responses. Light therapy for skin conditions like psoriasis usually use 313 nanometer UVB though it may use UVA (315–400 nm wavelength) or a broader spectrum UVB (280–315 nm wavelength). UVA combined with psoralen, a drug taken orally, is known as PUVA ...
Upon exposure to ultraviolet UV-B rays in the sun light, 7-DHC is converted into vitamin D 3 via previtamin D 3 as an intermediate isomer. It is also found in the milk of several mammalian species. [ 1 ] [ 2 ] Lanolin , a waxy substance that is naturally secreted by wool-bearing mammals, contains 7-DHC which is converted into vitamin D by ...
UV-B lamps are lamps that emit a spectrum of ultraviolet light with wavelengths ranging from 290–320 nanometers. This spectrum is also commonly called the biological spectrum due to the human body's sensitivity to light of such a wavelength. [1] UV-B light does not tan the skin very much, compared to the UV-A lamps that are used in tanning beds.
The location of 'far-UVC' radiation (200-235 nm) in the electromagnetic spectrum. Far-UVC is a type of ultraviolet germicidal irradiation being studied and commercially developed for its combination of pathogen inactivation properties and reduced negative effects on human health when used within exposure guidelines. [1] [2] [3] [4]
Of the various components of sunlight, ultraviolet radiation B (UVB) (290-320 nm) is considered to be the most harmful. This type of radiation acts primarily on the epidermis, and in particular the keratinocytes. Keratinocytes are known to form a barrier to provide a layer of protection within the skin against environmental hazards.
The extracorporeal (outside the body) method removes blood from the body and irradiates it in a special cuvette (tube). This method is used for the ultraviolet (UV) blood irradiation (UVBI) by UV lamps. In the transcutaneous method, the radiation goes through the skin, by placing a device on the outside of the skin.