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Abe K Abt I Ash WW Aston D Bacchetta N Baird KG Baltay C Band HR Barakat MB Baranko G Bardon O Barklow T Bazarko AO Ben-David R Benvenuti AC Bienz T Bilei GM Bisello D Blaylock G Bogart JR Bolton T Bower GR Brau JE Breidenbach M Bugg WM Burke D Burnett TH Burrows PN Busza W Calcaterra A Caldwell DO Calloway D Camanzi B Carpinelli M Cassell R Castaldi R Castro A Cavalli-Sforza M Church E Cohn HO Coller JA Cook V Cotton R Cowan RF Coyne DG D'Oliveira A Damerell CJ Dasu S De Sangro R De Simone P 《Physical review D: Particles and fields》1994,50(9):5580-5590
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Abe K Abt I Acton PD Agnew G Ash WW Aston D Bacchetta N Baird KG Baltay C Band HR Baranko G Bardon O Battiston R Bazarko AO Bean A Belcinski RJ Ben-David R Benvenuti AC Biasini M Bienz T Bilei GM Bisello D Blaylock G Bogart JR Bolton T Bower GR Brau JE Breidenbach M Bugg WM Burke D Burnett TH Burrows PN Busza W Calcaterra A Caldwell DO Calloway D Camanzi B Carpinelli M Carr J Cassell R Castaldi R Castro A Cavalli-Sforza M Chadwick GB Chen L Church E Claus R Cohn HO Coller JA Cook V Cotton R 《Physical review letters》1993,71(16):2528-2532
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Jean-Philippe Demaret † Simone Brunie Jean-Pierre Ballini Paul Vigny 《Photochemistry and photobiology》1989,50(1):7-21
The results of molecular mechanical calculations on intercalation complexes of 3-carbethoxypsoralen, 5-methoxypsoralen, 8-methoxypsoralen, 7-methylpyrido[3,4-c]psoralen (MepyPs) and 7-methylpyrido[4,3-c]psoralen (2N-MePyPs) with the double stranded duodecanucleotide d(CGCGATATCGCG)2 are presented. In the energy-minimized structures, the psoralens are intercalated with their plane orthogonal to the helix axis. Stacking interactions between the furan ring of the psoralen and the adjacent bases are maximized in most derivatives studied, whereas the effect of the various substituents of the psoralen ring is to specifically push part of the molecule towards either the minor or the major groove, preventing a symmetrical intercalation (with respect to the two strands of the DNA). The relative position of the psoralen ring and of the adjacent thymine foreshadows the formation of furan-side monoadducts in 3-CPs, MePyPs and 2N-MePyPs, whereas the formation of a pyrone-side monoadduct appears as geometrically more favourable in 5-MOP and both furan- and pyrone-side monoadducts can be geometrically envisaged in 8-MOP. A good correlation therefore exists between the more or less favourable equilibrium geometries and the experimentally observed photoreactions. The present study is the first attempt to characterize the geometrical parameters as part of a complex set of geometrical, dynamical and excited state parameters governing the overall DNA-psoralen photoreaction. 相似文献
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E. Alabiso P. Ciambelli V. De Simone C. Porcellu R. Valentino 《Reaction Kinetics and Catalysis Letters》1979,12(4):451-456
The catalytic activity of a chabazite tuff in the partial oxidation of H2S to sulfur has been determined. The effects of temperature, feed concentration and chemical composition of the tuff on H2S conversion and selectivity to sulfur have been investigated. Encouraging results in view of a possible use in H2S removal processes have been obtained.
H2S . , H2S . H2S.相似文献
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We studied the thermal diffusion behavior of poly(N-isopropylacrylamide) (PNiPAM) in ethanol in a temperature range from T = 14.0 degrees C to T = 40.0 degrees C by means of thermal diffusion forced Rayleigh scattering. The obtained Soret coefficient S(T) of PNiPAM was positive for lower temperatures (T < 34 degrees C), while S(T) showed a negative value for higher temperatures (T > 34 degrees C). This means PNiPAM molecules move to the cold side for temperatures T < 34 degrees C, whereas they move to the warm side for T > 34 degrees C. This is the first nonaqueous polymeric system for which a sign change with temperature has been observed. We performed static and dynamic light scattering experiments in the same temperature range. The second virial coefficient determined from dilute solutions by static light scattering (SLS) was positive in the comparable temperature range. The results of SLS for the semidilute solution showed a strong repulsion among PNiPAM chains which was enhanced by increasing temperature. These results imply that the observed thermally induced sign change of S(T) does not depend on the intermolecular interactions among PNiPAM chains. 相似文献