Kelner (1949a) first reported that mutations to phage resistance induced in Escherichia coli by ultraviolet light could be reversed by immediate irradiation with white light. In addition he noted that end-point mutations in contrast to zero-point mutations were not reversed by visible light (1949b). At the same time Novick and Szilard (1949) reported that light-reactivation of E. coli reduced t...

OBJECTIVE To study the effect of Xingding Injection on the expression of heat shock protein 72 (HSP 72) in vascular endothelial cells after ultraviolet radiation. METHODS Porcine aortic endothelial cells were cultured for 72 hours in culture mediums with different concentrations (0.1, 0.5, 1.0, 5.0, 10 mg/ml) of Xingding Injection. Ultraviolet radiation was administered to the cultured cells ...

Plasma is one of the most researched fields. Its use as a sterilizer is being rapidly explored. Thus, in this process it has become necessary to understand the effect of UV radiation produced due to plasma. The goal for our project is to measure the levels of ultraviolet radiation plasma creates and then compare the result with the safety standards of UV radiation individuals can be exposed to....

Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are...

While our data do not permit us to state the exact locus or mode of action of ultraviolet radiation in the Arbacia egg, certain general conclusions may be reached. The amount of delay of cleavage of these eggs is determined by two principal factors: (1) The extent of an effect, resulting from photochemical action induced by ultraviolet radiation, which is reversible in a biological sense, the r...

basil plants (ocimum basilicum l.) were sprayed with salicylic acid (1mm) and exposed to ultraviolet-c (uv-c) radiation (40 wm-2) after emergence of six developed leaves. plants were grown for 18 days and exposed to uv-c for 5 mind-1 alternatively. chlorophyll a, chlorophyll b and carotenoide were considered for analysis of photosynthetic pigments. the results showed that the photosynthetic pig...

ultraviolet waves, because of their short wavelength, have a high energy and considerable damaging effects on surfaces. protection against ultraviolet radiations is one of the finishing treatments done on surfaces exposed to sunlight. the importance of this issue in relation to human health, due to complications such as skin burns and cancer, is doubled. up to now, different materials such as z...

URING the first two decades following MULLER'S (1927) proof that D irradiation induced genetic changes, most of the effect was considered to result from ionizations (and excitations) within the chromosome itself. LEA (1946) interpreted the evidences accumulated up to that time as indicating that most genetic damage was induced directly, although he believed that ionizing and ultraviolet radiati...