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Volkerts M Bacelar JC van Goethem MJ Harakeh MN Hoefman M Huisman H Kalantar-Nayestanaki N Kopecky S Löhner H Messchendorp JG Nakayama K Ostendorf RW Schadmand S Scholten O Wilschut HW 《Physical review letters》2004,92(20):202301
Data on proton-neutron bremsstrahlung have been obtained from a measurement of the quasifree breakup channel in proton-deuteron bremsstrahlung. This high-precision measurement, with an incident proton energy of 190 MeV, is fully exclusive; i.e., the protons, the neutron, and the photon have been detected. The quasifree differential cross sections obtained are compared with microscopic calculations and calculations based on soft-photon models. There are sizable differences between the models and also between the models and the data obtained for this simple process. 相似文献
996.
Ali MM Alam MR Kawasaki T Nakayama S Nagatsugi F Sasaki S 《Journal of the American Chemical Society》2004,126(29):8864-8865
Nitric oxide (NO) is an important endogenous regulatory molecule, and S-nitrosothiols are believed to play a significant role in NO storage, transport, and delivery. On the basis of their ability to generate NO in vivo, S-nitrosothiols can be used as therapeutic drugs. In this study, we have developed an innovative method for sequence- and base-specific delivery of NO to a specific site of DNA followed by specific deamination. We designed a NO transfer reaction from S-nitroso thioguanine to an imino tautomer of cytosine. Nitrosation of the thioguanosine-containing ODN 1 was carried out with S-nitroso-N-acetylpenicillamine (SNAP) to produce ODN 2. An interstrand NO transfer reaction was performed using ODN 2 and its complementary ODN 3 having dC or dmC at the target site, and a rapid NO transfer reaction was observed. In contrast, a transfer reaction was not observed either with ODN 3 having dT, dA, or dG at the target site or with ODN 5-7 having dC at a nontarget site. In the analysis of deaminated products of the NO-transferred ODN 4, it was found that the transformation ratio from dmC to dT was as high as 42% together with the dmC-diazoate (13%). In conclusion, we have demonstrated the innovative method of sequence- and base-specific delivery of nitric oxide to cytidine and 5-methylcytidine. The selectivity and efficiency of NO transfer followed by deamination exhibited in this study are extremely high compared to those of the conventional methods. 相似文献
997.
3,3-Disubstituted dithiirane 1-oxides were efficiently reduced with Lawesson's reagent (LR) to give the corresponding dithiiranes. X-ray diffraction analysis of 3,3-di(1-adamantyl)dithiirane is reported. Reaction of (34)S-labeled 3,3-di(1-adamantyl)dithiirane 1-oxide with LR produced the corresponding dithiirane in which the (34)S atoms were retained quantitatively. 相似文献
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H Akagi T Hayashi T Nakayama T Nakajima T X Watanabe H Sokabe 《Chemical & pharmaceutical bulletin》1982,30(7):2498-2502
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