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Ultraviolet Exposure (ultraviolet + exposure)
Selected AbstractsVitamin D and innate immunityDERMATOLOGIC THERAPY, Issue 1 2010Jeremiah Miller ABSTRACT Vitamin D's role in bone health has been well established. Recently, studies have identified additional roles of vitamin D in the immune system, cardiovascular system, and cancer prevention. The effect of vitamin D on the immune system is particularly relevant to the dermatologist in that it has implications for atopic dermatitis, psoriasis, and skin cancer. However, there is much disagreement on a dose of vitamin D that is both safe and effective as both ultraviolet exposure and certain vitamin D-rich foods come with unwanted consequences. This review aims to update the dermatologist on the roles of vitamin D in the immune system, the safety and dose of different sources, and risk factors for vitamin D deficiency that may necessitate supplementation. Immune consequences of vitamin D status represent one additional aspect that illustrates how guidelines for supplementation are needed and will only be useful clinically if they are presented in context with validated controlled clinical trials. [source] Synthesis of autophotosensitive hyperbranched polyimides based on 3,3,,4,4,-benzophenonetetracarboxylic dianhydride and 1,3,5-tris(4-aminophenoxy)benzene via end capping of the terminal anhydride groups by ortho -alkyl anilineJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 13 2003Huan Chen Abstract Benzophenone-containing, anhydride-terminated hyperbranched poly(amic acid)s were end-capped by ortho -alkyl aniline in situ and then chemically imidized, yielding autophotosensitive hyperbranched polyimides. The polyimides were soluble in strong polar solvents, such as N -methyl-2-pyrrolidone, N -dimethylformamide, dimethylacetamide, and dimethyl sulfoxide. Thermogravimetric analysis revealed their excellent thermal stability, with a 5 wt % thermal loss temperature in the range of 527,548 °C and a10 wt % thermal loss temperature in the range of 562,583 °C. The strong absorption of the polyimide films in ultraviolet,visible spectra at 365 nm indicated that the hyperbranched polyimides were patternable. Highly resolved images with a line width of 6 ,m were developed by ultraviolet exposure of the polymer films. A well-defined image with lines as thin as 3 ,m was also patterned, but the lines were rounded at the edges. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2026,2035, 2003 [source] Large Photoinduced Densification in Organically Modified Germanosilicate GlassesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2004Jae Hyeok Jang Organically modified germanosilicate (ORMOGSIL) glasses prepared by a sol-gel method showed a large refractive index change on ultraviolet exposure. The large photoinduced refractive index change in the ORMOGSIL glasses is mainly due to the structural densification caused by ultraviolet irradiation. The shifts in frequency of the Raman bands measured at room temperature reveal structural densification by reduction of the average intertetrahedral bonding angle , in the ORMOGSIL glasses. Surface relief patterns by photoinduced densification were directly inscribed on the ORMOGSIL glasses. [source] Is casual exposure to summer sunlight effective at maintaining adequate vitamin D status?PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 4 2010Brian L. Diffey Background/purpose: The advice that an adequate vitamin D status can be achieved by short, casual exposure to summer sunlight is ubiquitous. This review will examine the value of this advice. Methods: The results of experimental studies on changes in serum 25-hydroxyvitamin D [25(OH)D] concentrations following ultraviolet exposure are interpreted in the context of human exposure to sunlight. Results: It is shown that current advice about modest sun exposure during the summer months does little in the way of boosting overall 25(OH)D levels, while sufficient sun exposure that could achieve a worthwhile benefit would compromise skin health. Conclusions: Failure to understand the nature of human exposure to sunlight has led to misguided advice concerning the sun exposure necessary for an adequate vitamin D status. [source] A quantitative estimate of melanoma mortality from ultraviolet A sunbed use in the U.K.BRITISH JOURNAL OF DERMATOLOGY, Issue 3 2003B.L. Diffey Summary Background, Concern has been expressed for many years in the medical and regulatory literature about the adverse health effects, especially melanoma, from the use of sunbeds for cosmetic tanning. Objectives, To estimate the mortality from melanoma as a result of the use of sunbeds for cosmetic tanning in the U.K. Methods A model using a Monte Carlo random sampling technique was developed to estimate human ultraviolet exposure to both sunlight and sunbeds, and these data were used to predict the contribution of sunbeds to melanoma mortality in the U.K. Results, The mortality from melanoma due to sunbed use each year in the U.K. is estimated to be about 100 deaths. Conclusions, Sunbed use could be regarded as a relatively minor self-imposed detriment to public health compared with other voluntary ,pleasurable' activities associated with significant mortality, such as smoking and drinking alcohol. While cosmetic tanning using sunbeds should be discouraged, prohibition is not warranted especially as exposure to the sun, which cannot be regulated, remains the major contributory factor to the risk of melanoma. [source] | |||||||||||||