نتایج جستجو برای: ultraviolet radiation effect
تعداد نتایج: 1874289 فیلتر نتایج به سال:
Urocanic acid is a major ultraviolet (UV)-absorbing chromophore. Chitins are highly crystalline structures that are found predominantly in crustacean shells. Alpha-chitin consists of microfibers that contain nanofibrils embedded in a protein matrix. Acid hydrolysis is a common method used to prepare chitin nanofibrils (NFs). We typically obtain NFs by hydrolyzing chitin with acetic acid. Howeve...
We analyzed the effects of UV radiation (UVR) effects on acetylcholinesterase (AChE) activity in two calanoid copepods, Boeckella gibbosa and Parabroteas sarsi that inhabit Patagonian shallow lakes. We studied the effect of experimental UVR (UV-B and UV-A) exposure on AChE activity in relation to basal antioxidant capacities of both copepods. Our experiments showed that UVR can effectively depr...
Ultraviolet (UV) radiation in high doses may have harmful effects on the eye. The sources of UV radiation are the sun, as well as some artificial sources such as UV lamps or voltaic arcs. Chronic exposure to UV can cause damage to the anterior pole of the eye, ranging from minor (pterygium) to serious photokeratitis. In our study, we applied a UV dose of 6.5 J/cm(2) in the wavelength range of 2...
Copper nanowires were prepared through electrochemical template synthesis using Nucleopore polycarbonate membranes having nominal pore sizes of 800nm and 15nm diameter. The 800nm and 15nm nanowires thus grown were viewed under SEM and TEM respectively, while their FCC crystallographic structure was confirmed through X-ray and electron diffraction patterns. The X-ray diffraction peaks indicated ...
Defects in the bacterial recB or recC or phage red or int gene did not impair ultraviolet light-induced clear mutations of lambda phage. Clear mutants of cI and cII genes were not enriched among RecA-promoted UV-induced recombinants between the N and O genes which closely encompass the c genes. No correlation was observed between UV-induced mutation and genetic recombination.
Pressure ulcers heal slowly and this often results in prolonged hospitalization. Wound infection delays healing in decubitus ulcers and standard treatment include wound dressing and use of antibiotics. However, there is increasing resistance of bacteria to antibiotics. The purpose of this study was to determine the effects of ultraviolet radiation (UVB) on the healing of decubitus ulcers. The s...
We perform radiation hydrodynamics simulations on the evolution of galactic gas disks irradiated by ultraviolet radiation background. We find gas disks with NH & 10 cm exposed to ultraviolet radiation at a level of I21 = 1 can be self-shielded from photoheating, whereas the disk with NH . 10 cm cannot. We also find that the unshielded disks keep smooth density distribution without any sign of f...
Skin cancer incidence in Croatia is steadily increasing in spite of public and governmental permanently measurements. It is clear that will soon become a major public health problem. The primary cause of skin cancer is believed to be a long exposure to solar ultraviolet (UV) radiation. The future designers of UV protective materials should be able to block totally the ultraviolet radiation. The...
CONTEXT Skin cancer is a preventable and commonly diagnosed cancer in the U.S. Excessive ultraviolet radiation exposure is a known cause of skin cancer. This article presents updated results of two types of interventions evaluated in a previously published Community Guide systematic review: multicomponent community-wide interventions and mass media interventions when used alone. EVIDENCE ACQU...
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