Liquid cultures of the terrestrial cyanobacterium Nostoc commune derived from field material were treated with artificial UV-B and UV-A irradiation. We studied the induction of various pigments which are though to provide protection against damaging UV-B irradiation. First, UV-B irradiation induced an increase in carotenoids, especially echinenone and myxoxanthophyll, but did not influence prod...

PURPOSE UV-C irradiation of corneal epithelial cells elicits K+ channel activation, which in turn causes them to undergo apoptosis. In the present study, the intermediary role played by mitogen-activated protein kinase (MAPK) signaling pathways in mediating this response was investigated. METHODS Western blot and kinase assays were used to measure UV-induced activation (i.e., phosphorylation)...

We examine the gelation of alginate undergoing ionic crosslinking upon ultraviolet (UV) irradiation using in situ dynamic rheology. Hydrogels are formed by combining alginate with calcium carbonate (CaCO3) particles and a photoacid generator (PAG). The PAG is photolyzed upon UV irradiation, resulting in the release of free calcium ions for ionic crosslinking. The viscous and elastic moduli duri...

The subcellular distribution and posttranslational modification of human chromatin assembly factor 1 (CAF-1) have been investigated after UV irradiation of HeLa cells. In an asynchronous cell population only a subfraction of the two large CAF-1 subunits, p150 and p60, were found to exist in a chromatin-associated fraction. This fraction is most abundant during S phase in nonirradiated cells and...

.. Several strains of beta-hemolytic Streptococci produce streptokinase enzyme that can bind and activate human plasminogen to plasmin. Streptokinase degrades the fibrin lump by its explicit lysine joining site and so it is applied as a remedy in thrombolytic therapy. The purpose of the study was to subject wild strain of Streptococcus equisimilis to strain development technique, using random m...

The galaxy M 31 is interesting, in particular, because its diffuse interstellar medium emits the Unidentified Infrared Bands although it is devoid of far UV radiation. This compels us to seek an alternative to stochastic, transient, heating of dust by absorption of far UV photons. The alternative proposed here is chemiluminescence, or the excitation of the vibrations of chemical bonds of carbon...

OBJECTIVE To determine the effectiveness of a pulsed xenon ultraviolet (PX-UV) disinfection device for reduction in recovery of healthcare-associated pathogens. SETTING Two acute-care hospitals. METHODS We examined the effectiveness of PX-UV for killing of Clostridium difficile spores, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus (VRE) on glass carri...

The aims of the study were to characterize a nanostructured photoactive titanium dioxide (TiO(2)) coating and to compare the cellular response of human osteoblasts before and after ultraviolet (UV) irradiation of the coating. A specific nanostructured TiO(2) powder (Degussa P-25), which consists of approximately 80% anatase and 20% rutile, was spin-coated onto commercially pure titanium discs, ...

We have studied the effect of UV irradiation on the cell cycle progression of synchronized Chinese hamster ovary cells. Synchronization of cells in S or G2 phase was accomplished by the development of a novel protocol using mimosine, which blocks cell cycle progression at the G1/S boundary. After removal of mimosine, cells proceed synchronously through the S and G2 phases, allowing manipulation...

DNA damage triggers complex cellular responses in eukaryotic cells, including initiation of DNA repair and activation of cell cycle checkpoints. In addition to inducing cell cycle arrest, checkpoint also has been suggested to modulate a variety of other cellular processes in response to DNA damage. In this study, we present evidence showing that the cellular function of xeroderma pigmentosum gr...