Metal oxide (MO) nanoparticles have been studied as nano-antibiotics due to their antimicrobial activities even in antibiotic-resistant microorganisms. We hypothesized that a hybrid system of dual UV irradiation and MO nanoparticles would have enhanced antimicrobial activities compared with UV or MO nanoparticles alone. In this study, nanoparticles of ZnO, ZnTiO3, MgO, and CuO were selected as ...

Exposure of mammalian cells to ultraviolet (UV) light elicits a cellular response and can also lead to apoptotic cell death. In this report, we show that a 36-kDa myelin basic protein (MBP) kinase detected by an in-gel kinase assay can be dramatically activated during the early stages of UV irradiation-triggered apoptosis of A431 cells. Immunoblot analysis revealed that this 36-kDa MBP kinase c...

Spore-forming microbes recovered from spacecraft surfaces and assembly facilities were exposed to simulated Martian UV irradiation. The effects of UVA (315 to 400 nm), UVA+B (280 to 400 nm), and the full UV spectrum (200 to 400 nm) on the survival of microorganisms were studied at UV intensities expected to strike the surfaces of Mars. Microbial species isolated from the surfaces of several spa...

BACKGROUND DNA damage in mammalian cells stabilizes the p53 protein which then functions as a cell cycle checkpoint by leading to growth arrest or apoptosis. p53 is a transcription factor and positively regulates the expression of the p21/WAF-1 gene and the mdm2 gene. After high-dose UV irradiation, p53 increases the expression of the p21/WAF-1 gene immediately (2 to 5 hours after irradiation) ...

The tumor-suppressor gene p53 encodes a phosphoprotein involved in the control of cell growth. p53 expression and function have been documented in malignancy, apoptosis and the aging processes. Recently, p53 has been mapped and characterized in the normal cornea across different species. In the present study, high levels of cytoplasmic p53 protein...

Synchronized and asynchronously growing cells of a V79 sub-line of the Chinese hamster were either whole-cell irradiated ( gamma, 254 nm) or laser-UV-microirradiated ( gamma, 257 nm). Post-incubation with caffeine (1-2 mM) often resulted in chromosome shattering, which was a rare event in the absence of this compound. In experiments with caffeine, the following results were obtained. Shattering...

In this study, in order to achieve effective coating of the homogeneous titanium dioxide (TiO2) thin film, UV irradiation pre-treatment was carried out to activate PC surfaces before coating. Sol-gel-based nanocrystalline TiO2 thin films were prepared by employing tetrabutyl-titanate as a precursor. Nanocrystalline TiO2 thin films were deposited by sol-gel spin coating on the treated substrates...

UV irradiation of mammalian cells activates AP-1 through a Ras-dependent pathway, independently of DNA damage. We show that the yeast S. cerevisiae has a remarkably similar UV response involving the AP-1 factor Gcn4, which is distinct from the DNA damage response. Transcriptional activation of HIS3 and HIS4 by Gcn4 is triggered by UV irradiation in a Ras-dependent fashion. Moreover, resistance ...

PURPOSE The object of this study was to investigate the effect of UV irradiation (by a general commercial UV sterilizer) on anodized titanium surface. Surface characteristics and cellular responses were compared between anodized titanium discs and UV irradiated anodized titanium discs. MATERIALS AND METHODS TITANIUM DISCS WERE ANODIZED AND DIVIDED INTO THE FOLLOWING GROUPS: Group 1, anodized ...

In both natural and agricultural conditions, plants are frequently subjected to unfavourable environments, resulting in varying degrees of stress. UV irradiation, drought, heat shock, chilling/freezing, salinity and oxygen deficiency are a few of the major abiotic factors restricting plant growth and development. An important consequence of stratospheric ozone depletion is increased transmissio...