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41.
2-氨基二甲基吡啶镉的单晶已被单晶定向的~(113)Cd核磁共振进行了研究。在CdCl_2+2-氨基二甲基吡啶中对于两个氯-四个氮的~(113)Cd的屏蔽张量元素分别是σ_(33)=368,σ_(22)=266,和σ_(11)=236×10~(-6)。 相似文献
42.
核酸切割试剂与寡聚核苷酸(ODN)偶联制得的人工核酸酶能在特定位点断裂DNA或RNA,为人工核酸酶的分子设计提供了一种新方法.本文综述了金属配合物-ODN识别切割试剂的偶联方式及其与靶分子的作用机制,并指出了今后的研究方向. 相似文献
43.
Quantitative study on La~(3+) influx mediated by sodium-calcium exchanger in human lymphocytes 总被引:2,自引:0,他引:2
Whether La3+ can enter human peripheral blood lymphocytes by the Na+/Ca2+ exchanger or not and the effect of La3+on the Na+/Ca2+ exchanger activity are examined by fura-2 technique. And that whether La3+ is sequestered by intracellular organelles (mainly endoplasmic reticulum and mitochondria) is studied by this method. La3+uptake is obviously stimulated by pre-treating the cells with ouabain and by removing extracellular Na+, and intracellular La3+concentration ([La3+]i) is directly proportional to its extracellular concentration ([La3+]o). But when [La3+]o exceeds 0.4 mmol/L, the 340/380 nm ratio of fluorescence is no longer varied and the maximum [La3+], is 1.5×10-12 mol · L-1. The higher concentration of La3+ (0.1 mmol/L) increases Na+/Ca2+ exchange-mediated calcium influx, but lower concentration (10 μmol/L) appears to block calcium influx. The results also suggest that cytosolic La3+ is transported by the ATP-dependent Ca2+ pump. Intracellular Ca2+ stores are depleted by ionomycin, and then ion 相似文献
44.
With fluorometry this paper has proved that alpha-cyclodextrin (CD) and gamma-CD do not form inclusion complexes with procaine, while beta-CD and HP-beta-CD do. Their molar ratios are demonstrated both 1:1 with the equimolar variation method. The constant current coulometric titration method (CCCT) is first proposed and applied in the determination of the CD inclusion constant. To compare with this method, the fluorescence experiment has been done with the satisfactory results. 相似文献
45.
Chao J Meng D Li J Xu H Huang S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(3):729-734
The interaction of ciprofloxacin with HP-beta-cyclodextrin (HP-beta-CD) has been studied by several analytical techniques, including 1H nuclear magnetic resonance (NMR), 13C NMR, fluorescence spectra, infrared spectroscopy, thermal analyzer and scanning electron microscope. In this paper, solid inclusion complex of ciprofloxacin with HP-beta-CD was synthesized by the coprecipitation method. In addition, the characterization of the inclusion complex has been proved by fluorimetry, infrared, differential scanning calorimetry and one-dimensional (1D), 2D NMR. The experimental results confirmed the existence of 1:1 inclusion complex of ciprofloxacin with HP-beta-CD. The formation constant of complex was determined by fluorescence method and 1H NMR. Spacial configuration of complex has been proposed on two-dimensional NMR technique. 相似文献
46.
TIAN Yan-Ni YANG PinInstitute of Coordination Chemistry The State Key Laboratory of Coordination Chemistry Nanjing University Nanjing Jiangsu ChinaLI Qing-Shan ZHAO Chun-GuiInstitute of Molecular Science Shanxi University Taiyuan Shanxi China 《中国化学》1996,14(5):428-436
New complexes,of bis(2,2'-diamino-4,4'-bithiazole)sulfate nickel(Ⅱ) and bis(2,2'-diami-no-4,4'-bithiazole)sulfate cobalt(Ⅱ),have been prepared.The complexes were characterized by infrared and UV-Vis spectroscopy,1H NMR,elemental analyses and molar conductivity.The effect of these complexes on the DNA synthesis of sarcoma 180 cells has been studied by the technique of isotopic liquid scintillation.The results indicated that complexes show ability to inhibit DNA synthesis of the tumor cells.In order to provide a molecular basis for understanding the biological effects,the probe,[trana-en2Os(η2-H2)](CF3SO3)2 (en,ethylenediamine) as a monitor was first used to explore interaction of the complexes with 2'-deoxyguanosine-5'-monophosphate (dGMP). 相似文献
47.
48.
针对国际上对金属配合物同DNA间作用机量的争议,采用分子模拟手段在MM2力场下,搭建并优化了手性金属配合物△,Λ-[Co(phen)2tpphz]^3+与B-DNA[d(GTCGATCGAC)2]的模型,继而对其相互作用进行了模拟,得出的结论是:对所采用的B-DNA片断,该金属配合物有明显的立体选择性△型配合物从小沟插入占明显优势,而且,总体来看,从AT区插入更易进行。 相似文献
49.
细胞色素P450的电化学研究从一个侧面反映了为使细胞色素P450达到工业催化剂的最终目的人们所作的不懈努力。本文从细胞色素P450在电极上的电子转移研究,隧道扫描显微镜的微观成像研究和使用电极作为细胞色素P450的电子给体从而实现细胞色素P450底物转化三方面,评述了近年来细胞色素P450的电化学研究进展。 相似文献
50.
Wei Y Guo X Shuang S Dong C Sun X Wong M 《Journal of photochemistry and photobiology. B, Biology》2005,81(3):190-194
Novel dimeric capsules are generated from the noncovalent assembly of 5, 10, 15, 20-tetrakis(4-N-ethylpyridiniurmyl)prophyrin (TEPyP) and tetracarboxyl-phenyl calix[4]arene. The self-assembly system was investigated based on UV-Vis absorption and fluorescent spectra. The factors affecting the interaction process including pH and concentration were examined in detail. The association constants between TEPyP and calix[4]arene were determined by the nonlinear least squares fit. The results showed that the basic medium is favourable to the interaction and electrostatic interaction was determinate in the processes of self-assembly process. The related mechanism was discussed. 相似文献