Recently, apoptosis (genetically programmed cell death) induced by UV has been documented in some cell culture models. However, the significance of apoptosis in UV-induced cytotoxicity and resistance is uncertain. In this study, we investigated the induction of apoptosis in HeLa cells and its role in acquired UV-resistance. The membrane receptor Fas was induced to assembly, and its immediate do...

Solar Water Disinfection (SODIS) is a simple, yet effective method for water decontamination by utilizing heat and UV-A from sunlight to kill microbes. However, the mechanism for UV-A mediated cell death is unknown. UV-A has been shown to cause DNA damage by the induction of reactive oxygen species (ROS). This damage might cause cell death in SODIS. Therefore, we investigated whether limiting t...

Endonuclease V of bacteriophage T4 possesses two enzymatic activities, a DNA N-glycosylase specific for cyclobutane pyrimidine dimers (CBPD) and an associated apurinic/apyrimidinic (AP) lyase. Extensive structural and functional studies of endonuclease V have revealed that specific amino acids are associated with these two activities. Controversy still exists regarding the role of the aromatic ...

Adenoviruses are resistant to monochromatic, low-pressure (LP) UV disinfection--but have been shown to be susceptible to inactivation by polychromatic, medium-pressure (MP) UV--when assayed using cell culture infectivity. One possible explanation for the difference between UV lamp types is that the additional UV wavelengths emitted by MP UV enable it to cause greater damage to viral proteins th...

OBJECTIVE To determine if UV-B phototherapy clears psoriasis through systemic effects. DESIGN Randomized, within-subject comparison of change in psoriasis in 3 plaques in patients attending for whole-body UV-B therapy. Change in patients' psoriasis plaques covered during UV-B treatment was compared with plaques in an untreated control group. SETTING University hospital phototherapy unit. ...

Mushrooms are prone to microbial spoilage and browning during growing and processing. Ultraviolet light (254 nm, UV-C) has been used as an alternative technology to chemical sanitizersfor food products. Hydrogen peroxide (H2O2) is classified as generally recognized as safe for use in foods as a bleaching and antimicrobial agent, and could control the bacterial blotch and browning of mushrooms. ...

A measurement campaign was performed in the region of Vienna and its surroundings from May to July 2007. Within the scope of this campaign erythemal UV was measured at six ground stations within a radius of 30 km. First, the homogeneity of the UV levels within the area of one satellite pixel was studied. Second, the ground UV was compared to ground UV retrieved by the ozone monitoring instrumen...

Photoinhibition is light-induced inactivation of PSII, and action spectrum measurements have shown that UV light causes photoinhibition much more efficiently than visible light. In the present study, we quantified the contribution of the UV part of sunlight in photoinhibition of PSII in leaves. Greenhouse-grown pumpkin leaves were pretreated with lincomycin to block the repair of photoinhibited...

The use of Aspergillus niger (A. niger) fungal spores as challenge organism for UV reactor validation studies is attractive due to their high UV-resistance and non-pathogenic nature. However A. niger spores UV dose-response was dependent upon sporulation conditions and did not follow the Bunsen-Roscoe Principle of time-dose reciprocity. Exposure to 8 h of natural sunlight for 10 consecutive day...