Ultraviolet laser irradiation of a lithium niobate +z polar surface enables the production of ridge waveguides. Ultraviolet laser induced inhibition of poling is used to define an inverted domain pattern which transforms into a ridge structure by differential etching in Hydrofluoric acid. The laser irradiation step also induces a refractive index change that provides the vertical confinement wi...

In previous communications the authors have described the cellular and subcellular responses to ultraviolet irradiation directed to whole Chang liver cells and to portions of Chang liver cells (3-6). Two sources of ultraviolet have been utilized in these studies. One source was a mercury arc lamp the output of which was passed through a grating monochromator, and the second source was the ultra...

Aqueous solutions of isovaline and its precursor molecule, 5-ethyl-5-methylhydantoin, were irradiated with ultraviolet and γ-ray photons, to evaluate their structural stability against space radiation. The degree of photolysis was measured and irradiation products were identified using chiral, reversed-phase and ion-exchange high-performance liquid chromatography. The experimental results show ...

Effects of ultraviolet-B radiation on the photosynthesis of seagrasses (Halophila engelmanni Aschers, Halodule wrightii Aschers, and Syringodium filiforme Kütz) were examined. The intrinsic tolerance of each seagrass to ultraviolet-B, the presence and effectiveness of photorepair mechanisms to ultraviolet-B-induced photosynthetic inhibition, and the role of epiphytic growth as a shield from ult...

Thermodynamical and optical properties of pure and electron beam irradiated (20, 80 and 100 kGy doses) liquid crystalline material cholesteryl pelargonate (nonanoate) have been investigated by differential scanning calorimeter, polarized light microscopy and ultraviolet-visible spectroscopy. Transition temperatures, enthalpies and entropies are found to be lowered due to the irradiation. A dono...

Involvement of Py pyrimidine dimers Py correnconucleases I and II in repair of ultraviolet radiation damage in vivo by Micrococcus luteus has been demonstrated by their absence in the ultraviolet-sensitive mutant DB-7 derived by treatment of the wild type parent with N-methyl-N'-nitro-N-nitrosoguanidine. The necessity for their combined action in DNA repair in M. luteus is shown by: (a) reactiv...

An increase in the amount of tyrosinase was demonstrated in the cultured human melanocyte after 6-day culturing with cholecalciferol (vitamin D3) by increased intensity of the immunofluorescent staining using monoclonal antibody against tyrosinase. Furthermore, the melanocytes became more dendritic as noted in those in the skin after the irradiation of ultraviolet. However, 7-dehydrocholesterol...

The addition of the enzyme catalase to cells of certain strains of E8cherichia coli strain K 12, after exposure to ultraviolet light (2537A), has been found to increase the survival ratio (Monod et al., 1949; Latarjet et al., 1954; Miletic, 1954; Teti, 1954). Catalase has also been found to counteract the biological effects produced in Micrococcus pyogenes var. aureus, either by ultraviolet irr...