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F.t.-i.r. and laser-Raman spectra of thymine and thymidine in the solid state were recorded. Assignments were proposed for the frequencies observed. The influence of the deoxy sugar on the vibrations of the nucleoside are discussed as a function of its particular puckering. The aim of this work is to elucidate the differences between the molecules constituting the nucleic acids, in order the better to comprehend their biological functions. 相似文献
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F.t.-i.r. and laser-Raman spectra of cytosine and cytidine 总被引:1,自引:0,他引:1
Fourier-transform infrared (F.t.-i.r.) and laser-Raman spectra of cytosine and cytidine in the solid state have been recorded and assignments of the frequencies made. Comparison of the observed frequencies for cytosine with those for cytidine permits identification of the bands characteristic of the sugar on the one hand, and of the pyrimidine base on the other. 相似文献
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W F Ward H Aceto R Jolly D Buckle 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1976,30(4):317-326
Rats were exposed under aerobic or hypoxic conditions to 200-1200 rads of 60Co gamma-rays or extended-Bragg-peak helium ions on the eighth day of gestation. Uterine contents were examined on the twentieth day of gestation. At the 50 per cent embryonic survival level, helium ion r.b.e. was 1(.0) (aerobic) and 1(.2) (hypoxic). Maximum attainable gamma-ray and helium-ion o.e.r.s. were 2(.2) and 1(.7) respectively, indicating an oxygen-effect gain (o.e.g.) of 1(.2). At the 10 per cent survival level helium ion r.b.e. was 1(.1) (aerobic) and 1(.4) (hypoxic). Gamma-ray and helium-ion 0.e.r.s. were 2(.0) and 1(.5) respectively, indicating a helium ion o.e.g. of 1(.3). These data demonstrate that the small fraction of high-LET radiation present in this helium ion beam has a neglible effect on the aerobic r.b.e., but lowers the effective o.e.r. of the beam approximately 25 per cent relative to that of gamma-rays. Helium ions were significantly more effective than gamma-rays in killing embryos under hypoxic conditions, in producing congenital abnormalities under aerobic conditions, and in stunting foetal growth under both conditions. 相似文献
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F.t.-i.r. and laser-Raman spectra of guanine and guanosine 总被引:1,自引:0,他引:1
Fourier-transform infrared (F.t.-i.r.) and laser-Raman spectra have been obtained for solid guanine. The F.t.-i.r. spectrum of guanosine in the solid state was also recorded. Assignments are proposed for the i.r. bands. The molecular basis of the spectral differences between guanine and guanosine are discussed. 相似文献
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Webb-Johnson 《BMJ (Clinical research ed.)》1949,1(4592):70-71
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The 1H- and 13C-n.m.r. spectra of eledoisin and minor oligopeptides were measured and assigned. The proton spectra were interpreted on the basis of homonuclear decoupling, chemical shift criteria and spectra simulation. The information obtained was used in the assignment of the 13C spectrum via heteronuclear 1H-13C. The steric arrangement of proline residue was deduced from the 13C spectrum. Moreover the similarity of the 13C spectrum of eledoisin with that of component oligopeptides suggests that no considerable conformational change occurs in the undecapeptide relative to the component fragments. 相似文献
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T.H. Thomas 《Plant Growth Regulation》2000,31(3):226-227
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