Sunlight, exposure

It is primarily for testing materials to be used in products subject to indoor exposure and to sunlight. Exposure in the Fadeometer cannot be related directly to exposure in direct sunlight, partially because other weather factors are always present outdoors. 

Vitamin D is not strictly a vitamin since it can be synthesized in the skin, and under most conditions that is its major source. Only when sunlight is inadequate is a dietary source required. The main function of vitamin D is in the regulation of calcium absorption and homeostasis most of its actions are mediated by way of nuclear receptors that regulate gene expression. Deficiency—leading to rickets in children and osteomalacia in adults—continues to be a problem in northern latitudes, where sunlight exposure is poor. 

Worwood, M. (1990). Ferritin. Blood Rev. 4, 259-269. Yohn, J.J., Duncan, K.O., Loudon, E., Dormish, J., Repine, J.E. and Norris, D.A. (1992). Human keratinocyte catalase synthesis is decreased by simulated sunlight exposure (abstr). J. Invest. Dermatol. 98, 655A. 

Fletcher, A. E., G. C. Bentham et al. (2008). Sunlight exposure, antioxidants, and age-related macular degeneration. Arch. Ophthalmol. 126(10) 1396-1403. 

Carr et al. [2004] studied the incidence of different cleaning procedures on wool. ToF-SIMS analyses performed on the commercially scoured wool (negative ion mode) showed the presence of 18-methyleicosanoic acid thioester species (m/z 341), attributed to the presence of 18-methyleicosanoic acid (18-MEA) which is normally the predominant compound of the surface layer of wool. Other lipids are also detected. After artificial sunlight exposure, analyses show that 18-MEA disappears from the surface. 

A second issue that apparently elevates public anxiety about industrial products to a high level concerns the fact that people feel they have little or no personal control over those products. Tobacco and alcohol usage, diet, reproductive and sexual habits, and sunlight exposure are... 

Phototoxicity It is prudent for patients to minimize or avoid natural or artificial sunlight exposure. 

Photoreactivity In Tubo Prescreening of Compounds Producing ROS Upon Sunlight Exposure... 

Limit UV/sunlight exposure, wear protective clothing, and use sunsreen due to increased risk of skin cancer... 

Treatment of psoriasis should be limited to once-daily application not to exceed 20% of total body surface area. Adverse local effects include a burning or stinging sensation (sensory irritation) and peeling, erythema, and localized edema of the skin (irritant dermatitis). Potentiation of photosensitizing medication may occur, and patients should be cautioned to minimize sunlight exposure and to use sunscreens and protective clothing. 

A pressure-sensitive tape having an extremely long life under sunlight exposure is needed for use in sealing gaps between glass panels. 

Hayashi, N., Togawa, K., Yanagisawa, M., Hosogi, J., Mimura, D., and Yamamoto, Y., Effect of sunlight exposure and aging on skin surface lipids and urate, Exp. Dermatol., 12, 13-17, 2003. 

However, a study by Salih (2006) demonstrated that when a food additive was present in E. coli cell suspension during sunlight exposure, the number of induced mutations increased to varying extents over that seen with sunlight alone. Vanilla produced mutations in an additive fashion,... 

So it is difficult to draw comparisons between the performance of fibers on sunlight exposure. Available publications containing data obtained with undyed materials show that acrylic fibers consistently have excellent resistance to photodegradation whether exposed to direct sunlight or to sunlight behind glass (13, 18, 28, 29, 30). The comparative... 

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