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UV Protection (uv + protection)
Selected AbstractsInteraction of vitamins C and E as better cosmeceuticalsDERMATOLOGIC THERAPY, Issue 5 2007Karen E Burke ABSTRACT:, Although many cosmeceutical formulations contain vitamin C and/or vitamin E, very few are actually effective in topical application. First because there is only a low concentration, second because the stability is compromised as soon as the product is opened and exposed to air and light, and third because the form of the molecule (an ester or a mixture of isomers) is not absorbed or metabolized effectively by the skin. However, when a stable formulation delivers a high concentration of the nonesterified, optimal isomer of the antioxidant, vitamins C and E do indeed inhibit the acute ultraviolet (UV) damage of erythema, sunburn, and tanning as well as chronic UV photoaging and skin cancer. Both are highly effective depigmenting agents. Topical vitamin C also increases collagen synthesis in both young and old fibroblasts. Because vitamin C regenerates oxidized vitamin E, the combination in a cosmeceutical formulation is synergistic , particularly in UV protection. [source] Tuning and Transcription of the Supramolecular Organization of a Fluorescent Silsesquioxane Precursor into Silica-Based Materials through Direct Photochemical Hydrolysis,Polycondensation and MicropatterningADVANCED FUNCTIONAL MATERIALS, Issue 3 2009Xavier Sallenave Abstract A new fluorescent silsequioxane precursor with tuned optical properties and controlled aggregation properties is designed. The two cyclohexyl moieties introduced in the molecular structure allow the formation of very good quality films. The J-aggregated structure is transcribed into the solid by photoacid-catalyzed hydrolysis,polycondensation. Aggregation of the chromophores is reduced and highly fluorescent materials are obtained. The photoacid generator lies on the surface of the homogeneous layer of the sol,gel precursor. This phase separation presents several advantages, including UV protection of the chromophore and easy removal of the PAG. The first example of chemical amplification in the photolithography of the conjugated silsesquioxane precursor is demonstrated. As hydrolysis,polycondensation could be achieved in a controlled way by UV exposure, chemically amplified photolithography is achieved by irradiating a composite film (,110,nm thick) on silicon wafer by using a copper TEM grid as shadow mask. The pattern is produced uniformly on a miscroscopic scale of 3,mm, the photopatterned pixels remaining highly fluorescent. The sizes of the photolithographed pixels correspond to the sizes of the rectangular holes of the 300,×,75 mesh grid (hole: 63,<$>,<$>m,×,204,<$>,<$>m). [source] A quick, practical test procedure to evaluate the performance of instruments used for in vitro UV protection measurementsINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 6 2002E. Klette Synopsis The in vitro determination of the UV protection of sunscreens is usually performed by means of transmission measurements with special photometers. Many different instruments are used. Besides numerous commercially available instruments, which are equipped by the manufacturer for the specific measurement, other modular instruments are used. We present here a quick and practical method to evaluate the performance of these instruments with respect to their measuring ranges and to compare the uniformity and reliability of the results obtained with these instruments. Résumé La détermination in vitro de la protection anti-UV de produits solaires est généralement réalisée par la mesure de la transmission à l'aide de photomètres spéciaux. De nombreux appareils peuvent être utilisés à cette fin. A côté des instruments disponibles dans le commerce et spécialement équipés par les fabricants, d'autres appareils modulaires peuvent être employés. Nous présentons ici une méthode rapide et pratique pour évaluer les performances de ces appareils en respectant leurs gammes de mesure et pour comparer la crédibilité et l'uniformité des résultats obtenus. [source] The European standard for sun-protective clothing: EN 13758JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2 2006T Gambichler Abstract Clothing is considered one of the most important tools for sun protection. Contrary to popular opinion, however, some summer fabrics provide insufficient ultraviolet (UV) protection. The European Committee for Standardization (CEN), has developed a new standard on requirements for test methods and labelling of sun-protective garments. This document has now been completed and is published. Within CEN, a working group, CEN/TC 248 WG14 ,UV protective clothing', was set up with the mission to produce standards on the UV-protective properties of textile materials. This working group started its activities in 1998 and included 30 experts (dermatologists, physicists, textile technologists, fabric manufacturers and retailers of apparel textiles) from 11 European member states. Within this working group, all medical, ethical, technical and economical aspects of standardization of UV-protective clothing were discussed on the basis of the expertise of each member and in consideration of the relevant literature in this field. Decisions were made in consensus. The first part of the standard (EN 13758-1) deals with all details of test methods (e.g. spectrophotometric measurements) for textile materials and part 2 (EN 13758-2) covers classification and marking of apparel textiles. UV-protective cloths for which compliance with this standard is claimed must fulfill all stringent instructions of testing, classification and marking, including a UV protection factor (UPF) larger than 40 (UPF 40+), average UVA transmission lower than 5%, and design requirements as specified in part 2 of the standard. A pictogram, which is marked with the number of the standard EN 13758-2 and the UPF of 40+, shall be attached to the garment if it is in compliance with the standard. The dermatology community should take cognizance of this new standard document. Garment manufacturers and retailers may now follow these official guidelines for testing and labelling of UV-protective summer clothes, and the sun-aware consumer can easily recognize garments that definitely provide sufficient UV protection. [source] Review of the potential photo-cocarcinogenicity of topical calcineurin inhibitorsJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 6 2005Position statement of the European Dermatology Forum ABSTRACT, Topical Calcineurin Inhibitors (TCIs) used for the treatment of atopic eczema modify the immune regulatory function of the skin and may have the potential to enhance immunosuppressive ultraviolet (UV) effects. Current recommendations on UV protection in eczema patients treated with PCIs are inconsistent and have given rise to uncertainty and anxiety in patients. Therefore, the European Dermatology Forum (EDF) developed a position statement which reviews critically the available data with regard to the problem, especially analysing and commenting the limitations of rodent models for the human situation. There is no conclusive evidence from rodent trials to indicate that long-term application of TCIs is photococarcinogenic. There is a need for further studies to investigate the validity of mouse models as well as long-term cohort studies in patients using TCIs. Available data suggest that long-term application of TCIs is safe, that there is no evidence of increased skin cancer risk and that it is ethical to treat patients with TCIs when indicated. [source] Microspectrophotometric Analysis of Intact Chromatophores of the Japanese Medaka, Oryzias latipesPIGMENT CELL & MELANOMA RESEARCH, Issue 2 2000TINA N. ARMSTRONG To investigate the possible photoprotective role of chromatophores in fish, the absorbances of four types of intact chromatophores in adult and larval Japanese medaka were analyzed using microspectrophotometric techniques. The absorbance spectrum of each chromatophore class was obtained from 300 to 550 nm. The absorbance spectra of intact leucophores, melanophores and xanthophores were very similar to the published absorbance spectra of the isolated pure pigments contained in each chromatophore type, pteridines, melanin and carotenoids or pteridines, respectively. Based on these absorbance spectra, leucophores and melanophores should provide the most ultraviolet (UV) photoprotection to fish since the compounds they contain, pteridines and melanin, correspondingly, have strong absorbances in the UV region of the spectrum. Xanthophores containing carotenoids are not likely to provide much protection to fish from UV-induced damage since carotenoids have low absorbances in the UV range. Xanthophores containing colored pteridines, however, may provide somewhat greater UV protection to fish, since pteridines absorb more light than carotenoids in the UV portion of the spectrum. The relative frequency, coverage and thickness of these two types of xanthophores should determine how much protection xanthophores as a chromatophore type would provide against UV-induced damage. [source] Significance of Flavonoids in Plant Resistance and Enhancement of Their BiosynthesisPLANT BIOLOGY, Issue 6 2005D. Treutter Abstract: The roles of flavonoids in plant defence against pathogens, herbivores, and environmental stress are reviewed and their significant contribution to plant resistance is discussed. The induction of flavonoids is of particular interest for gathering evidence of their roles. Tools are mentioned which may enhance flavonoid biosynthesis and accumulation. These include metabolic engineering and UV light. The induction of defence-related flavonoids is modified by other determining factors and competition between growth and secondary metabolism may exist. In an evolutionary context, stress-related oxidative pressure may have been a major trigger for the distribution and abundance of flavonoids. UV protection is one of their most significant, or even the most significant, functional role for flavonoids. The multi-functionality of these compounds, however, often complicates the interpretation of experimental results but, overall, it supports the importance of flavonoids. [source] The influence of ultraviolet radiation on growth, photosynthesis and phenolic levels of green and red lettuce: potential for exploiting effects of ultraviolet radiation in a production systemANNALS OF APPLIED BIOLOGY, Issue 3 2010E. Tsormpatsidis Studies have shown that natural ultraviolet (UV) radiation increases secondary products such as phenolics but can significantly inhibit biomass accumulation in lettuce plants. In the work presented here, the effect of UV radiation on phenolic concentration and biomass accumulation was assessed in relation to photosynthetic performance in red and green lettuce types. Lettuce plants in polythene clad tunnels were exposed to either ambient (UV transparent film) or UV-free conditions (UV blocking film). The study tested whether growth reduction in lettuce plants exposed to natural UV radiation is because of inhibition of photosynthesis by direct damage to the photosynthetic apparatus or by internal shading by anthocyanins. Ambient levels of UV radiation did not limit the efficiency of photosynthesis suggesting that phenolic compounds may effectively protect the photosynthetic apparatus. Growth inhibition does, however, occur in red lettuce and could be explained by the high metabolic cost of phenolic compounds for UV protection. From a commercial perspective, UV transparent and UV blocking films offer opportunities because, in combination, they could increase plant quality as well as productivity. Growing plants continuously under a UV blocking film, and then 6 days before the final harvest transferring them to a UV transparent film, showed that high yields and high phytochemical content can be achieved complementarily. [source] | |||||||||||||