نتایج جستجو برای: ultraviolet radiation uv a
تعداد نتایج: 13529841 فیلتر نتایج به سال:
In order to evaluate the effects of ultraviolet radiation (UV; 280 400 nm) on aquatic ecosystems, and to predict the potential influence of enhanced ultraviolet-B radiation (UV-B; 280 320 nm) from ozone depletion, it is necessary to observe the effects of natural and experimentallyaltered UV on different biological and chemical systems, and to quantify measured responses as functions of irradia...
To optimize their growth and survival, plants perceive and respond to ultraviolet-B (UV-B) radiation. However, neither the molecular identity of the UV-B photoreceptor nor the photoperception mechanism is known. Here we show that dimers of the UVR8 protein perceive UV-B, probably by a tryptophan-based mechanism. Absorption of UV-B induces instant monomerization of the photoreceptor and interact...
The results of spectral measurements of the daily near-noon surface direct solar ultraviolet radiation in the wavelength range of 295–345 nm obtained in Irkutsk (East Siberia) for the time interval of 1998–2000 are presented. For the period under consideration, the seasonal UV radiation variations are analysed that are associated with the total ozone dynamics, the transition of cyclonic and ant...
Ultraviolet (UV) radiation is the source energy for tropospheric photolysis processes, while harmful for living organism of the earth. It is thus necessary to incorporate UV radiation for an integrated earth modeling system to predict interactions between climate, chemistry and ecosystem processed. The widely-used NCAR TUV (Tropospheric Ultraviolet and Visible) radiation model has been coupled ...
The isolation and characterization of mutants hypersensitive to ultraviolet (UV) radiation has been a powerful tool to learn about the mechanisms that protect plants against UV-induced damage. To increase our understanding of the various mechanisms of defense against UVB radiation, we searched for mutations that would increase the level of tolerance of Arabidopsis plants to UV radiation. We des...
Introduction: The skin, can be exposed to harmful factors like ultraviolet radiation (UV). Exposure to this physical hazardous agent could be contributed to pigmentation, erythemas, early aging, skin cancer, and DNA damage. The aim of this study, therefore, was to fabricate the polyacrylonitrile (PAN) nanofibers with the UV protection property by the use of various concentrations of titanium di...
Global warming and ozone depletion, and the resulting increase of ultraviolet radiation (UVR), have far-reaching impacts on biota, especially affecting the algae that form the basis of the food webs in aquatic ecosystems. The aim of the present study was to investigate the interactive effects of temperature and UVR by comparing the photosynthetic responses of similar taxa of Chlorella from Anta...
Excessive ultraviolet (UV) radiation induces acute and chronic effects on the skin, eye and immune system. Personalized monitoring of UV radiation is thus paramount to measure the extent of personal sun exposure, which could vary with environment, lifestyle, and sunscreen use. Here, we demonstrate an ultralow modulus, stretchable, skin-mounted UV patch that measures personal UV doses. The patch...
s the most common type of cancer in the United States, skin cancer is a significant public health issue.1 It is estimated that in 2004 more han 1 million people will be diagnosed as having basal ell carcinoma and squamous cell carcinoma, and 2300 ill die. Melanoma, predicted to affect 55,100 individals, has a much higher mortality rate and will result in 900 deaths.2 Furthermore, although rates...
Fusarium oxysporum strain BM-201 was treated with ultraviolet (UV) radiation to obtain a high pectinase-producing strain. Mutant UV-10-41 was obtained and then treated by diethyl sulfate. Next, the mutant UV-diethyl sulfate-43 derived from UV-10-41 was selected as high pectinase-producing strain. Mutant UV-diethyl sulfate-43 was incubated on slant for 10 generations, demonstrating that the pect...
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