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71.
Noncovalent complexes of DNA and Hoechst 33258 were investigated by ESI-FT/ICR MS in various activation modes (collision-induced dissociation (CID), sustained off-resonance irradiation collision-induced dissociation (SORI-CID), infrared multiphoton dissociation (IRMPD) and electron detachment dissociation (EDD)). The binding selectivity of Hoechst 33258 was confirmed by the comparative study of its noncovalent association with different DNA sequences. The CID spectra of [ds + HO - 5H](5-) obtained with a linear hexapole ion trap resulted in unzipping of the strands. This outcome is a clue to the drug-binding mode, shading light on the localization of the binding sites of Hoechst 33258 to the DNA sequence. The IRMPD and SORI-CID experiments mainly gave DNA backbone cleavages and internal fragment ions. From this result, information on the localization of the binding sites of Hoechst 33258 in the DNA sequence was obtained. No sodium cationization was observed on the DNA sequence ions although they were present on fragmentation of the duplex, indicating that the backbone cleavages were generated from the single strand associated with the Hoechst 33258 where the number of alkali cation is restricted. Under electron detachment (ED) conditions, multiple EDs were achieved for the [ds + HO - 5H](5-) ion without any significant dissociation. The presence of drug appears to enhance the stability of the multiply charged system. It was proposed that the studied noncovalent complex involved the formation of zwitterions and consequently strong salt-bridge interactions between DNA and drug. 相似文献
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肖辉 孙丽萍 赵辉 霍丽华 Jean-Marc Bassat Aline Rougier Sbastien Fourcade Jean-Claude Grenier 《无机化学学报》2013,29(18)
采用固相法合成了中温固体氧化物燃料电池(IT-SOFCs)阴极材料LaBiMn2O6,并利用X射线衍射(XRD)和电化学阻抗谱(EIS)进行表征.结果表明该材料与电解质Ce0.7Bi0.3O1.85(CBO)在1 000 ℃烧结12 h不发生反应.交流阻抗和直流极化测试结果发现,阴极极化电阻随测试温度的增加而逐渐减小,700 ℃空气中的极化电阻为0.71 Ω·cm2;氧分压测试结果显示,在600~700 ℃范围内,电极反应的速率控制步骤为电极上发生的电荷转移反应.电极过电位为85 mV时,700 ℃的阴极电流密度达到 216 mA·cm-2 ,表明LaBiMn2O6是一种潜在的中温固体氧化物燃料电池(IT-SOFCs)阴极材料. 相似文献
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范宇航 孙丽萍 霍丽华 赵辉 Jean-Marc Bassat Aline Rougier Sbastien Fourcade Jean-Claude Grenier 《无机化学学报》2013,29(18)
采用EDTA-柠檬酸法合成了中温固体氧化物燃料电池阴极材料Sr1.5La0.5Mn1-xCoxO4(SLMCOx),并利用粉末X射线衍射(XRD)、X射线光电子能谱(XPS)以及电化学交流阻抗谱(EIS)进行表征。结果表明,该材料与Ce0.9Gd0.1O1.95(CGO)在1 200℃烧结12 h不发生化学反应。随着Co掺入量的增加,氧化物中Mn3+和Co2+含量增多,晶格氧含量降低,晶格畸变率增大。交流阻抗谱(EIS)测试结果显示,钴的掺杂明显降低电极的极化电阻,其中Sr1.5La0.5Mn0.7Co0.3O4阴极在700℃空气中的极化电阻为0.62 Ω·cm2,明显小于Sr1.5La0.5MnO4阴极在750℃的极化电阻(1.5 Ω·cm2),表明钴掺杂的Sr1.5La0.5Mn1-xCoxO4是一种潜在的IT-SOFC阴极材料。 相似文献
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Jean-Claude Petit 《Accreditation and quality assurance》1999,4(11):458-462
An appropriate Quality approach in fundamental research should have its roots in the very principles of the "scientific method".
Quality and fundamental research could thus reconcile at the condition, on the one hand, that Quality practioners understand
and take into account the reality of the "science in action" and, on the other hand, that scientists improve their awareness
of the new deal which is being made between science, technology and society as well as of the actual issues of Quality. A
modern Quality approach, well adapted to this specific activity, should help both scientists, decision-makers and the public
face the issues concerning the role of science in society in the future. In this context, I specify a number of practical
proposals concerning, in particular, the adaptation of the requirements of the quality approach to the type of research, the
distinction between the three major steps of a research programme (i.e. quality of the objective, the process and the results)
and the encouragement of experience feedback.
Received: 8 March 1998 / Accepted: 8 December 1998 相似文献
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The activation parameters for the oxidation of 13 secondary alcohols with chromic acid have been determined. Application of a statistical treatment of Exner [9] shows that the reactions are isoentropic with an average entropy of activation (ΔS≠) of ?24.0 e. u. 相似文献
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