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161.
InteractionbetweenMetalinMetalloEnzymeandSmallBiologicalMolecules¥HuJie-Han;ShuZan-Yong;TaoLi-Mei;ChengGuo-Bao(DalianInstitut... 相似文献
162.
Sequence heterogeneity in a portion of the mitochondrial cytochrome c oxidase subunit 1 gene (pcox1) was measured for the hookworms, Ancylostoma caninum from Australia, A. duodenale from China, and Necator americanus from China and Togo using single-strand conformation polymorphism (SSCP) analysis combined with DNA sequencing. The pcox1 sequences were characterised for individual nematodes displaying genetic variation within each of the three species, and those were compared with pcox1 sequences of four other species of hookworm. While intraspecific variation in the pcox1 sequence ranged from 0.5 to 8.6% for A. caninum, 0.3 to 3.3% forA. duodenale, and 0.3 to 4.3% for N. americanus, interspecific differences varied from 4.8 to 12.9%. Sequence data also provided information on nucleotide compositions and substitution patterns. Genetically distinct groups were detected within A. caninum and A. duodenale, indicating significant population substructuring within these species. Also, N. americanus individuals from China all differed from those from Togo at four nucleotide positions, supporting a previous proposal (based on ribosomal DNA sequence data) that N. americanus may represent a species complex. The findings indicated the value of pcox1 sequence data and the mutation scanning approach for studying the genetic structures of hookworm populations, which should have important epidemiological relevance. 相似文献
163.
164.
Tanaka K Mori M Xu Q Helaleh MI Ikedo M Taoda H Hu W Hasebe K Fritz JS Haddad PR 《Journal of chromatography. A》2003,997(1-2):127-132
In this study, an aqueous solution consisting of benzoic acid with low background conductivity and beta-cyclodextrin (beta-CD) of hydrophilic nature and the inclusion effect to benzoic acid were used as eluent for the ion-exclusion chromatographic separation of aliphatic carboxylic acids with different pKa values and hydrophobicity on a polymethacrylate-based weakly acidic cation-exchange resin in the H+ form. With increasing concentration of beta-cyclodextrin in the eluent, the retention times of the carboxylic acids decreased due to the increased hydrophilicity of the polymethacrylate-based cation-exchange resin surface from the adsorption of OH groups of beta-cyclodextrin. Moreover, the eluent background conductivity decreased with increasing concentration of beta-cyclodextrin in 1 mM benzoic acid, which could result in higher sensitivity for conductimetric detection. The ion-exclusion chromatographic separation of carboxylic acids with high resolution and sensitivity was accomplished successfully by elution with a 1 mM benzoic acid-10 mM cyclodextrin solution without chemical suppression. 相似文献
165.
In this paper, the voltammetric method was used for the first time to study the effect of Cisplatin-liposome on Hela cells. The results showed the voltammetric behavior of Hela cells was irreversible and the peak current had linear relationship with the cell number. With both Cisplatin-liposome concentration and treating time increasing, the peak current decreased. The peak current decreasing was in accordance with the nuclear damage and loss of mitochondrial membrane potential revealed by two-photon laser scanning microscopy and confocal laser scanning microscopy. This voltammetric method may provide a simple way to study the electron-transfer mechanism in drug-treating cells. 相似文献
166.
A novel diterpene derivative, 5-methyl-5-(4,8,12-trimethyl-tridecyl)-dihydro-furan-2-one (1) and a new chromone, 5-hydroxy-7-methoxy-3-methyl-chromen-4-one (2), along with a known compound, phytol (3) have been isolated from the aerial parts of Hypericum perforatum. Their structures were established on the basis of spectroscopic analysis and by comparison with published values. 相似文献
167.
Reaction of 1,4-diisocyanobenzene or 4-isocyanobenzonitrile with trans-W(N(2))(2)(DPPE)(2) (DPPE = 1,2-bis(diphenylphosphino)ethane) produced cis-WL(2)(DPPE)(2), where L = 1,4-diisocyanobenzene or 4-isocyanobenzonitrile. cis-(CNC(6)H(4)NC)(2)W(DPPE)(2) crystallizes in the triclinic space group P&onemacr;, with a = 12.848(3) ?, b = 13.596(3) ?, c = 19.072(3) ?, alpha = 78.99(2) degrees, beta = 70.66(2) degrees, gamma = 65.26(2) degrees, V = 2849.8(11) ?(3), and Z = 2. cis-(NCC(6)H(4)NC)(2)W(DPPE)(2) crystallizes in the triclinic space group P&onemacr;, with a = 12.712(3) ?, b = 13.700(3) ?, c = 19.109(3) ?, alpha = 77.91(2) degrees, beta = 70.63(2) degrees, gamma = 64.76(2) degrees, V = 2830.7(13) ?(3), and Z = 2. Both compounds possess a distorted octahedral geometry about the metal center, with the two isocyanide ligands cis to one another. The isocyanide ligands are substantially bent along the CNC axis of the isocyanide group coordinated to tungsten. For the complex containing the symmetric ligand, CNC(6)H(4)NC, the mean CNC angle for the coordinated end of the isocyanide is 139.1(11) degrees, the average W-C bond length is 1.86(1) ?, and the C&tbd1;N bond lengths have a mean value of 1.30(2) ?. These data indicate substantial back-donation from an electron-saturated tungsten atom. This is supported spectroscopically, with substantial shifts to lower wavenumbers for the C-N stretching frequencies of the coordinated isocyanide groups. Similar trends are observed in cis-(NCC(6)H(4)NC)(2)W(DPPE)(2). Both compounds contain electron-rich metals surrounded by large ligands which apparently protect the metals from atmospheric oxidation. The isocyanide ligands in both complexes contain a second coordinating group pointing away from the metal into the environment surrounding the molecules, providing the potential for polymetallic complexes containing metals in a variety of oxidation states. 相似文献
168.
Hong-Wen Hu Xu-Dong Wei Cun Li Hong-Zhe Sun Yi-Ming Yao Zhong-Yuan Zhou Kai-Bei Yu 《中国化学》1992,10(3):278-284
The reaction of m-chlorobenzaldoxime dehydrodimer with styrene gives two 1:1 adducts.The main product 7 is a bisnitrone. The minor product 8 has been shown by X-ray diffraction anal-ysis to possess the structure: ArCH(N=O)CH_2CH (Ph)O--N=CHAr. The two C=N bonds areall in Z configuration. The structure of the adducts from benzaldoxime dehydrodimer and styrene isalso assigned. 相似文献
169.
四核钴羰基簇合物Co4(CO)8(μ-CO)2(μ4-PSR)2的合成和晶体结构 总被引:1,自引:0,他引:1
The title compounds Co4(CO)8(μ-CO)2 (μ4-PSR) [R=-CH3, -C2H5, -C(CH3)3,-(CHa)4CH3] were synthesized by the reaction of Co2(CO)8 with RSPCl2. They were characterized by IR, 1HNMR, elemental analysis. The crystal and molecular structure of Co4(Co)8(μ-CO)2 (μ4-PSC2H5) has been determined by single crystal diffraction method. Crystal data: monoclinic, space group P21 /c, with a=8-445(3), 6=8.562(3), c= 17.125(6)Å, β=104.26 (3)' 9 V=1200.1Å3, Z=2, Dc=1.937gcm-3. Its molecular structure contains an octahedral Co4P2 skeleton which consists of a rectangular four cobalt atoms core and the Co4 core is capped above and below by two quadruply bridging PSR ligands. 相似文献
170.