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61.
Liu GD Zhong TS Huang SS Shen GL Yu RQ 《Fresenius' Journal of Analytical Chemistry》2001,370(8):1029-1034
A renewable amperometric immunosensor based on the sol-gel technique has been constructed by dispersing graphite, complement 3 (C3) antiserum, and sol-gel at low temperature. The prepared immunosensor is rigid, porous, and has a renewable external surface. A competitive binding assay has been used to determine C3 in human serum with the aid of C3 labeled with horseradish peroxidase. The enzyme-labeled antigen can readily diffuse toward the encapsulated antibody, which retains its binding properties. The experimental conditions for the assay with the biocomposite, including the loading of C3 antiserum in the biocomposite, the amount of labeled C3 in incubation solution, incubation time, and temperature, have been optimized. Using C3 labeled with horseradish peroxidase, and o-AP as the substrate, amperometric detection at -150 mV (relative to the SCE) results in a linear detection range of 1.17-35.1 microg mL(-1), with a detection limit of 0.56 microg mL(-1). Serum samples have been assayed and the results demonstrate the feasibility of the proposed immunosensor for clinical analysis. The surface of the immunosensor can be renewed simply by polishing to obtain a fresh immunocomposite ready to use in a new competitive assay. 相似文献
62.
Two inorganic-organic hybrid solids, Zn2(phen)(HPO3)2 (1) and Zn(phen)(HPO3) (2), have been synthesized under solvothermal conditions in the presence of 1,10-phenanthroline (phen) ligands. Their structures were determined by single-crystal X-ray diffraction and further characterized by FTIR, elemental analysis, powder X-ray diffraction, thermogravimetric analysis and fluorescent spectra. Compound 1 crystallizes in the triclnic system, space group P-1, , , , α=75.609(1)°, β=79.145(2)°, γ=67.157(2)°, , Z=2. Compound 2 is monoclinic, C2/c, , , , β=94.175(4)°, , Z=8. Both structures consist of 1D chains constructed from strictly alternating ZnO4 and HPO3 polyhedra through sharing vertices. The chains are further decorated by Zn-centered complex architectures, [Zn(phen)]2+ for 1 and [Zn(phen)2]2+ for 2. The 2D and 3D supramolecular arrays for 1 and 2 are stably stacked via strong π-π interactions of the phen groups, respectively. 相似文献
63.
负载型TiO2-聚酰亚胺亲水复合膜的制备与分离性能 总被引:4,自引:1,他引:4
采用溶解-流涎法,湿相转换法和干湿相转换法制轩了负载型TiO2-聚酰亚胺亲水复合膜,采用扫描电镜,红外光谱,压汞和透气性实验等手段对该膜的孔径分布,表面结构及扩散性能进行了表征,并讨论了制备亲水对膜孔结构的影响,实验结果表明,三种膜均具有很好的亲水性能,而干湿相转换膜具有良好的孔径分布和分离性能。 相似文献
64.
The CHCl3 extract of dried roots of Hemerocallis fulva (L.) L. afforded a novel diterpene named hemerocallal A ( 1 ), which is the second reported naturally occurring diterpene with a trans‐bicyclo[5.1.0]octane system. The BuOH extract afforded a new glycoside named hemerocalloside ( 2 ). Their structures were established on the basis of spectroscopic and chemical studies. 相似文献
65.
Sesquiterpene Lactone Glycosides from Carpesium macrocephalum 总被引:1,自引:0,他引:1
Two new sesquiterpene lactone glycosides were isolated from the seeds of Carpesium meacrocephalum. Their structures were elucidated as 2α-O-β-D-glucopyranosy-5α,11αH-eudesma-4(15)-en-12,8β-olide and 2α-O-β-D-glucopyranosy-5αH-eudesma-4(15),11(13)-dien-12,8β-olide by spectral methods (HRMS,1D and 2D NMR). 相似文献
66.
Nicolaou KC Baran PS Zhong YL Barluenga S Hunt KW Kranich R Vega JA 《Journal of the American Chemical Society》2002,124(10):2233-2244
The discovery and development of the o-iodoxybenzoic acid (IBX) reaction with certain unsaturated N-aryl amides (anilides) to form heterocycles are described. The application of the method to the synthesis of delta-lactams, cyclic urethanes, hydroxy amines, and amino sugars among other important building blocks and intermediates is detailed. In addition to the generality and scope of this cyclization reaction, this article describes a number of mechanistic investigations suggesting a single electron transfer from the anilide functionality to IBX and implicating a radical-based mechanism for the reaction. 相似文献
67.
68.
Berkowitz SA Zhong H Berardino M Sosic Z Siemiatkoski J Krull IS Mhatre R 《Journal of chromatography. A》2005,1079(1-2):254-265
A simple high-resolution capillary zone electrophoresis (CZE) method capable of rapidly assessing the micro-heterogeneity of a 24 kDa molecular weight glycoprotein, has been developed. Separation is carried out using a bare silica capillary at a pH of 2.5 in a commercially available electrophoresis buffer system composed of triethanolamine and phosphoric acid. Over 30 peaks were detected within a run time of 15 min using a 27 cm capillary and approximately 60 peaks were detected using a 77 cm capillary. Although most of the peaks arise from differences in the oligosaccharide structures present on the one glycosylation site on this molecule, other forms of micro-heterogeneity due to the presence of the nonglycosylated form of this glycoprotein and various types of chemical degradation, e.g., deamidation, are also responsible for the multitude of peaks observed. Although the exact chemical identity of each peak in the resulting electropherogram of this glycoprotein is not known, useful information can be obtained for assessing comparability, stability, and batch consistency. Factors impacting the resolution, precision, accuracy, and robustness of the assay are also discussed along with inherent advantages and limitations associated with measuring the micro-heterogeneity of intact glycoproteins. 相似文献
69.
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
70.