Field emission (FE) behaviours of ZnO nanoneedle array under ultraviolet (UV) irradiation have been investigated. UV irradiation noticeably stabilized the FE behaviours. Modifications in the tunnelling barrier height and effective aspect ratio due to the oxygen-related surface species, which can be desorbed by UV irradiation, are supposed to be responsible for these observations. © 2007 Elsevie...

Silver nanoparticles (Ag-NPs) were successfully synthesized using the UV irradiation of aqueous solutions containing AgNO(3) and gelatin as a silver source and stabilizer, respectively. The UV irradiation times influence the particles' diameter of the Ag-NPs, as evidenced from surface plasmon resonance (SPR) bands and transmission electron microscopy (TEM) images. When the UV irradiation time w...

Inhibition of photosynthesis by ultraviolet-A radiation (UV-A, 315-380 nanometers) was examined in three marine angiosperms: Halophila engelmannii Aschers, Halodule wrightii Aschers, and Syringodium filiforme Kütz. Sensitivity to UV-A and photosensitization to UV-A by photosynthetically active radiation (PAR, 380-700 nanometers) were characterized.Net photosynthesis by Halodule and Syringodium ...

UV is one of the major causes of DNA damage induced apoptosis. However, cancer cells adopt alternative mechanisms to evade UV-induced apoptosis. To identify factors that protect cancer cells from UV-induced apoptosis, we performed a genome wide short-hairpin RNA (shRNA) screen, which identified Zinc finger protein 598 (ZNF598) as a key regulator of UV-induced apoptosis. Here, we show that UV ir...

p53-mediated increase in cyclin-dependent kinase inhibitor p21(WAF1) protein is thought to be the major mediator of cell cycle arrest after DNA damage. Previously p21 protein levels have been reported to increase or to decrease after UV irradiation. We show that p21 protein is degraded after irradiation of a variety of cell types with low but not high doses of UV. Cell cycle arrest occurs despi...

Induction of p53 by DNA damage results in apoptosis of teratocarcinoma cells, whereas MDM2, encoded by a p53-responsive gene, can reverse this phenotype by inhibiting p53 function. Here we report that UV (10 or 20 J/m2), but not gamma irradiation (7 or 10 Gy), caused a massive apoptosis of human teratoma Tera-2 or murine testicular carcinoma F9 cells, both of which contain wild-type p53, but no...

UV irradiation has the potential to induce the development of lens opacities. This has been demonstrated since long with animal experiments. Unfortunately these animal cataracts did not explain or elucidate the epidemiological observation that the frequency of human cataracts--such as the so called senile cataract--is remarkably higher in regions with increased cosmic UV irradiation or in the p...

background: organophosphorus pesticides are one of the most consumable poisons. such poisons can enter water sources by different routes. since consuming some drinking water containing an amount of poison higher than the standard level, causes undesirable effects on human health. this research aimed to study the effectiveness of elimi­nating malathion from water by ultraviolet irradiation (uv) ...

The loss of stratospheric ozone and the accompanying increase in solar UV flux have led to concerns regarding decreases in global microbial productivity. Central to understanding this process is determining the types and amounts of DNA damage in microbes caused by solar UV irradiation. While UV irradiation of dormant Bacillus subtilis endospores results mainly in formation of the "spore photopr...

It was shown previously that CsI sensitivity can be substantially reduced by intense UV irradiation. In the present study we measure the influence of negative and positive electric fields on the degradation of CsI photocathode sensitivity when it is subject to a large dose UV irradiation. The UV sensitivity of positively biased CsI photocathodes did not decay as fast as in case of negatively bi...