The incidence and mortality rates of melanoma have risen for many decades in the United States. Increased exposure to ultraviolet (UV) radiation is generally considered to be responsible. Sunburns, a measure of excess sun exposure, have been identified as a risk factor for the development of melanoma. Because sunburns are primarily due to UVB (280-320 nm) radiation, UVB has been implicated as a...

During the course of a day human skin is exposed to solar UV radiation that fluctuates in fluence rate within the UVA (290-315 nm) and UVB (315-400 nm) spectrum. Variables affecting the fluence rate reaching skin cells include differences in UVA and UVB penetrating ability, presence or absence of sunscreens, atmospheric conditions, and season and geographical location where the exposure occurs....

The research reported in this paper on the changes in absorbance and the calibration of a proposed UVA (320-400 nm) dosimeter have established the phenothiazine-mylar combination as a potential UVA dosimeter for population studies of UVA exposures. The change in optical absorbance at 370 nm was employed to quantify the UVA exposures. This change starts to saturate at a change in absorbance of a...

Limbal stem cells (LSC) account for homeostasis and regeneration of corneal epithelium. Solar ultraviolet A (UVA) is the major source causing oxidative damage in the ocular surface. Autophagy, a lysosomal degradation mechanism, is essential for physiologic function and stress defense of stem cells. PAX6, a master transcription factor governing corneal homeostasis by regulating cell cycle and ce...

Exposure to UV radiation is known to be a causative factor in the induction of skin cancers and other sun-related disorders. Most acute responses of humans to UV exposure occur as a result of UVB (280 to 315 nm) exposures, as these wavelengths are highly sensitive in creating a human biological response. However, this does not mean that UVA radiation has no impact on human UV exposures and heal...

As part of a wider study into the use of smartphones as solar ultraviolet radiation monitors, this article characterizes the ultraviolet A (UVA; 320-400 nm) response of a consumer complementary metal oxide semiconductor (CMOS)-based smartphone image sensor in a controlled laboratory environment. The CMOS image sensor in the camera possesses inherent sensitivity to UVA, and despite the attenuati...

We investigated the effects of single and combined exposures to two ubiquitous environmental carcinogens, polycyclic aromatic hydrocarbons and UVA radiation, in Big Blue mouse embryonic fibroblasts. We quantified the cytotoxicity, DNA adduct formation, and induction of mutations in the cII transgene in cells treated with a single agent or combinations of agents in both direct and reverse order....

In Eastern cultures, such as India, it is traditionally recommended that women but not men cover their heads while working in the scorching sun. The purpose of this pilot study was to determine whether there was any scientific basis for this cultural tradition. We examined the differential cytotoxic effects of ultraviolet A light (UVA) on an established T cell line treated with female and male ...

background: different investigation showed that 5-methoxypsoralen and 8- methoxypsoralen reduce birth rates in the rats. objective: in this study we worked out the effect of methoxsalen together with ultraviolent a (uva) radiation on mature balb/c mice spermatogenesis. materials and methods: the ld50 standard was determined 160 mg/kg and the uva dose which causes erythema was calculated 0.046 j...

Photochemotherapy-in which a photosensitizing drug is combined with ultraviolet or visible radiation-has proven therapeutic effectiveness. Existing approaches have drawbacks, however, and there is a clinical need to develop alternatives offering improved target cell selectivity. DNA substitution by 4-thiothymidine (S(4)TdR) sensitizes cells to killing by ultraviolet A (UVA) radiation. Here, we ...