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981.
A piezoelectric nucleic acid sensor was constructed ofr detection of tumor necrosis factor gene.Two methods were employed for immobilization of nucleic acid probe on gold electrode of piezoelectric crystal.The results show that polyethyleneimine adbesion and glutaraldehyde cross-linking method has higher sensitivity,stability and selectivity than protein A method.The solid-phase nucleic acid hybridization of oligo unclecotides and tumor necrosis factor target gene sequence were monitorde using this sensor.Tumor necrosis factor gene sequence(580bp) was detected by this nucleic acid sensor for the first time. 相似文献
982.
Electrochromatography (EC) in microfluidic chips is emerging as an attractive alternative to capillary electrophoresis (CE) for on-chip separations. This review summarizes recent developments in the rapidly growing area of chip electrochromatography with a focus on "column" technologies. Relevant achievements are summarized according to the types of stationary phase used for the separations including open channels, microfabricated structures, and channels packed with beads or containing a porous monolith. The advantages and disadvantages of each, as well as practical aspects of their application, are discussed. The analytical performance of these devices is demonstrated with separations involving various families of compounds mostly in the reversed-phase chromatographic mode. 相似文献
983.
C. Bibaut‐Renauld D. Burget J. P. Fouassier C. G. Varelas J. Thomatos G. Tsagaropoulos L. O. Ryrfors O. J. Karlsson 《Journal of polymer science. Part A, Polymer chemistry》2002,40(18):3171-3181
The efficiency of several α‐diketones as visible light photoinitiators for the crosslinking of waterborne latex dispersions in the presence of acrylic monomers was evaluated. Among the eight α‐diketones studied, camphorquinone allows the fastest curing speed, and the curing of the acrylic waterborne coating is not affected by the presence of oxygen. The properties of the sunlight‐cured volatile organic compound (VOC)‐free pigmented paints prepared from the waterborne latex are as good or better than the equivalent conventional paint containing VOCs. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3171–3181, 2002 相似文献
984.
G. Gritzner P. Rechberger Prof. Dr. Viktor Gutmann 《Monatshefte für Chemie / Chemical Monthly》1976,107(3):809-814
The influence of solvents on the redox behaviour of bistriphenylphosphinomercury perchlorate has been investigated by polarographic, voltammetric and potentiometric methods. The electrode process was found to be reversible in acetonitrile, propylene carbonate, N,N-dimethylformamide and dimethyl sulfoxide. An irreversible process was observed in nitromethane employing the dropping mercury electrode as well as in N,N-dimethylthioformamide and N-methyl-2-thiopyrrolidinone employing the rotating platinum electrode. Half wave potentials and diffusion coefficients have been measured. A linear relationship between theE
1/2 and the donor number (DN) of the solvent has been found for the reversible electrode reactions. Ligand replacement occurs in N,N-dimethylthioformamide and N-methyl-2-thiopyrrolidinone.
Mit 1 Abbildung 相似文献
Mit 1 Abbildung 相似文献
985.
Graziano Bonetti Patrick Pibarot Alain Chaintreau Jean Paul Marion 《Journal of separation science》1992,15(5):305-306
The use of diethylene glycol monoethyl ether as a flavor solvent is restricted. Since existing methods of quantitation are tedious or require sophisticated multi-dimensional GC instrumentation, a simple method has been developed using low cost GC-MS. Monitoring of ions 31 and 45 enables quantitation of DEGEE in essential oils at levels down to 1 μg/g with accuracy equal to or better than 15%. 相似文献
986.
Hans‐Peter Kormann Günter Schmid Katrin Pelzer K. Philippot Bruno Chaudret 《无机化学与普通化学杂志》2004,630(12):1913-1918
Nanoporous alumina membranes, loaded with palladium and ruthenium nanoparticles of various size, were used for gas phase hydrogenation of 1, 3‐butadiene and for oxidation of carbon monoxide, respectively. Those membranes contain 109 ‐ 1011 pores per cm2, all running perpendicular to the surface. Membrane discs of 20 mm in diameter and only 60 μm thick, incorporated in a reactor in which the reactants can be pumped in a closed circuit through the pores, turned out to very actively catalyze hydrogenation of butadiene (Pd) and oxidation of CO (Ru). The activity of the Pd catalysts depends characteristically on the particles size, the gas flow, and of the educts ratio. As could be expected, larger particles are less active than smaller ones, whereas increasing gas flows in case of hydrogenation accelerates the reactions. Excessive hydrogen reduces selectivity with respect to the various butenes, but favours formation of butane. 相似文献
987.
A. Subbiah Pandi V. Rajakannan D. Velmurugan Masood Parvez Moon‐Jib Kim A. Senthilvelan S. Narasinga Rao 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):o164-o167
N‐(2‐Chlorobenzyl)‐1,2,3,4‐tetrahydroisoquinoline‐1,3‐dione, C16H12ClNO2, crystallizes in P21/n with three crystallographically independent molecules in the asymmetric unit, which differ slightly in conformation, N‐(2‐bromo‐4‐methylphenyl)‐1,2,3,4‐tetrahydroisoquinoline‐1,3‐dione, C16H12BrNO2, crystallizes in P21/n with one molecule in the asymmetric unit andN‐(2,3‐dichlorophenyl)‐1,2,3,4‐tetrahydroisoquinoline‐1,3‐dione, C15H9Cl2NO2, crystallizes in P21/c with one molecule in the asymmetric unit. In all three structures, the heterocyclic rings adopt approximately planar conformations. The pyridine rings are orthogonal to the substituted phenyl rings. In all three structures, the crystal packing is stabilized by intermolecular C—H?O hydrogen bonds. 相似文献
988.
Zhaoyang Cheng Shipei Xing Jun Guo Biao Cheng Lan‐Fang Hu Xing‐Hong Zhang Zhan Lu 《中国化学》2019,37(5):421-421
The cover picture shows that sequential 1,1‐dihydrosilylation of terminal aliphatic alkynes with primary silanes enabled by one earth‐abundant cobalt catalyst has been developed. This protocol is operationally simple using readily available aliphatic alkynes, including simple acetylene and complex drug derivative, for efficient access to valuable gem‐bis(dihydrosilyl)alkanes in highly regioselective and atom‐economic manners. Corresponding asymmetric transformations are achieved with excellent enantioselectivities. More details are discussed in the article by Lu et al. on page 457–461.
989.
A new method for indirect determination of captopril (CPT) with NaNO3 and NH4SCN by floatation and separation of copper has been studied. In the weak acid, a small amount of Cu(II) can be reduced to Cu(I) by CPT, then Cu(I) reacted with the SCN, which can float on the surface of the liquid phase with NaNO3. A good linear relationship is observed between the floatation yield (E%) of Cu(II) and the amount of captopril. The linear range is 2?32 mg/L. On the ground, captopril can be indirectly determined by determining E(%) of Cu(II). The method is simple, rapid, reliable and has good selectivity. The developed method can be applied to indirect determination of captopril with satisfactory results. 相似文献
990.
Dr. H. Newesely 《Monatshefte für Chemie / Chemical Monthly》1963,94(1):270-280
Zusammenfassung Zwecks Kristallisation von Carbonat-Apatiten wurden Hydrothermalreaktionen sowie Schmelzvorgänge bei Gemischen von Calciumphosphaten und Calcit untersucht. Die vorliegenden Produkte konnten mit analytischen, kristallchemischen und elektronenmikroskopischen Beobachtungen und Messungen als Einkristalle von Hydroxyl- bzw. Fluorapatit identifiziert werden mit einem Carbonatgehalt, der in der Kristallstruktur eingelagert ist.Mit 4 AbbildungenUnter Mitarbeit vonHelga Schmidt. Vortrag auf der Jahrestagung des Vereins Österreichischer Chemiker, Wien 1962. 相似文献