@article{EpeHaeringRamaiahetal.1993, author = {Epe, Bernd and H{\"a}ring, Martin and Ramaiah, Danaboyina and Stopper, Helga and Abou-Elzahab, Mohamed M. and Adam, Waldemar and Saha-M{\"o}ller, Chantu R.}, title = {DNA damage induced by furocoumarin hydroperoxides plus UV (360 nm)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86870}, year = {1993}, abstract = {Wben irradiated at 360 nm, furocoumarins with a hydroperoxide group in a side chain effciently give rise to a type of DNA damage that can best be explained by a photoinduced generation of hydroxyl radicals from the excited pbotosensitizers. The observed DNA damage profiles, i.e. the ratios of single-strand breaks, sites of base loss (AP sites) and base modifications sensitive to fonnamidopyrimidine-DNA glycosylase (FPG protein) and endonuclease m, are similar to the DNA damage profile produced by hydroxyl radicals generated by lonizing radiation or by xanthine and xanthine oxidase in the presence of Fe(III)-EDTA. No such damage is observed with the corresponding furocoumarin alcohols or in the absence of near-UV radiation. The damage caused by the photo-excited hydroperoxides is not influenced by superoxide dismutase (SOD) or catalase or by D2O as solvent. The presence of t-butanol, however, reduces both the formation of single-strand breaks and of base odifications sensitive to FPG protein. The cytotoxicity caused by one of the hydroperoxides in L5178Y mome lymphoma cells is found to be dependent on the near-UV irradiation and to be much higher than that of the corresponding alcohol. Therefore the new type of photoinduced damage occurs inside cells. Intercalating photosensitizers with an attached hydroperoxide group might represent a novel and versatile class of DNA damaging agents, e.g. for phototherapy.}, subject = {DNS-Sch{\"a}digung}, language = {en} } @article{StaikovaEngelsPericetal.1993, author = {Staikova, M. and Engels, Bernd and Peric, M. and Peyerimhoff, S. D.}, title = {Ab initio calculation of the vibronically averaged hyperfine coupling constants in the two lowest electronic states of H\(_2\)O\(^+\)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58998}, year = {1993}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {en} } @article{GittinsHarrisFieldetal.1993, author = {Gittins, C. M. and Harris, N. A. and Field, R. W. and Verges, J. and Ernst, W. E. and B{\"u}ndgen, P. and Engels, Bernd}, title = {Analysis and Depertubation of the C\(^2\)Π and D\(^2\)Σ\(^+\) states of CaF}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58980}, year = {1993}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {en} } @article{Engels1993, author = {Engels, Bernd}, title = {Study of influences of various excitation classes on ab initio calculated isotropic hyperfine coupling constants}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58973}, year = {1993}, abstract = {Reliable prediction of the isotropic hyperfine coupling constant A\(_{iso}\) is still a difficult task for ab initio calculations. Strang dependence on the method employed for its ca1culation has been found. Within a CI ansatz A\(_{iso}\) is considerably affected by the excitation classes taken into account within the CI calculation. In the present work the influence of various excitation classes on A\(_{iso}\) is examined. Calculations including all single, double, triple and a large part of the quadruple excitations are performed and the individual effects of the excitation classes are studied. It is found that the surprisingly good agreement found for S-CI treatments is due to large error cancellations. The importance of higher than double excitations arises from their indirect influence on the single excitations.}, subject = {Organische Chemie}, language = {en} } @article{MetropoulosEngelsPeyerimhoff1993, author = {Metropoulos, B. and Engels, Bernd and Peyerimhoff, S.D.}, title = {On the chemi-ionization reaction O + CH ----> HCO\(^+\)+ e\(^-\). Coollinear O-CH Approach}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58963}, year = {1993}, abstract = {We have investigated theoretically the importance of the O(\(^3\)P)+CH(a\(^4\sum^-\)) and the O(\(^3\)P)+CH(X\(^2\Pi\)) channels in the collinear chemi-ionization reaction O+CH->HCO\(^+\) +e\(^-\). We have found that both channels may lead to chemi-ionization via favorable Franck-Condon overlaps with the states ofthe ionic species.}, subject = {Organische Chemie}, language = {en} } @article{BentleyNormanGerstneretal.1993, author = {Bentley, T. W. and Norman, S. J. and Gerstner, E. and Kemmer, R. and Christl, Manfred}, title = {Solvolysis of Tricyclo[3.1.0.0\(^{2,6}\)]hex-3-yl and Bicyclo[2.1.1]hex-2-yl Sulfonates}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58689}, year = {1993}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {en} } @article{FeineisSchwarzHegmannetal.1993, author = {Feineis, E. and Schwarz, H. and Hegmann, J. and Christl, Manfred and Peters, K. and Peters, E.-M. and Schnering, H. G. von}, title = {Cycloadditionen von 6H-1,3,4-0xadiazin-6-onen (4,5-Diaza-α-pyronen), 13 - Diels-Alder-Reaktionen mit 6H-1,3,4-Oxadiazin-6-onen als Dienophil}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58673}, year = {1993}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {de} } @article{ChristlLanzendoerferGroetschetal.1993, author = {Christl, Manfred and Lanzend{\"o}rfer, U. and Gr{\"o}tsch, M. M. and Hegmann, J. and Ditterich, E. and H{\"u}ttner, G. and Peters, K. and Peters, E.-M. and Schnering, H. G. von}, title = {Cycloadditionen von 6H-1,3,4-0xadiazin-6-onen (4,5-Diaza-α-pyronen), 12 - Dieckmann-Kondensationen ohne Basen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58665}, year = {1993}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {de} } @article{ChristlMueller1993, author = {Christl, Manfred and M{\"u}ller, H.}, title = {Induktiver Effekt, negative Hyperkonjugation und Gegenion sind nicht die Ursache der besonderen Eigenschaften des Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anions. - Eine NMR-Studie mit phenylsubstituierten Modellen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-58655}, year = {1993}, abstract = {No abstract available}, subject = {Organische Chemie}, language = {de} }