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151.
A detailed investigation of the conditions for formation and extraction of the thiocyanate complex of osmium by polyether-type polyurethane foam is reported. The complex which formed in solution was extracted through the “cation-chelation” mechanism and distribution coefficients of more than 104 were obtained. By using conditions which inhibit the formation of the osmium-thiocyanate complex, it was possible to leave 95% of osmium in the aqueous phase while extracting more than 95% of ruthenium into polyurethane foam. 相似文献
152.
Distributed automated docking of flexible ligands to proteins: Parallel applications of AutoDock 2.4 总被引:17,自引:0,他引:17
Garrett M. Morris David S. Goodsell Ruth Huey Arthur J. Olson 《Journal of computer-aided molecular design》1996,10(4):293-304
Summary AutoDock 2.4 predicts the bound conformations of a small, flexible ligand to a nonflexible macromolecular target of known structure. The technique combines simulated annealing for conformation searching with a rapid grid-based method of energy evaluation based on the AMBER force field. AutoDock has been optimized in performance without sacrificing accuracy; it incorporates many enhancements and additions, including an intuitive interface. We have developed a set of tools for launching and analyzing many independent docking jobs in parallel on a heterogeneous network of UNIX-based workstations. This paper describes the current release, and the results of a suite of diverse test systems. We also present the results of a systematic investigation into the effects of varying simulated-annealing parameters on molecular docking. We show that even for ligands with a large number of degrees of freedom, root-mean-square deviations of less than 1 Å from the crystallographic conformation are obtained for the lowest-energy dockings, although fewer dockings find the crystallographic conformation when there are more degrees of freedom.The AutoDock 2.4 suite is written in ANSI C, and is supplied with Makefiles for the following platforms: Convex, DEC Alpha OSF/1, Hewlett-Packard Precision Architecture, Silicon Graphics, and Sun. The AutoDock suite of programs is freely available to the noncommercial scientific community and to educational establishments. Further information, including additional figures and MPEG animations showing all docked conformations for each test system, can be found at the following URL: http://www.scripps.edu/pub/olson-web/doc/autodock. 相似文献
153.
Paul Hemmes Onkar S. Tomer Arthur T. Poulos William Macanka 《Journal of Molecular Liquids》1984,28(1):33-47
A spectroscopic method for studying quadrupole formation is described, and experimental results are presented for lithium thiocyanate in a tetrahydrofuran/hexane solvent system. From molar absorptivity equations and an equation by Fuoss and Kraus, a direct relationship is derived between the quadrupole formation constant, KQ, and the dielectric constant of the medium. Experimental results are consistent with the equation and allow an estimate of the distance between lithium and thiocyanate in the ion pair. 相似文献
154.
155.
Canonical forms are found for all real four-dimensional matrices of the pseudo-orthogonal group which differs from the Lorentz group only in that its metric has twoplus signs and twominus signs. 相似文献
156.
Appropriate selection of subjects is a critical element in assuring a valid evaluation of the clinical usefulness of a laboratory test. Careful definition of the clinical question to be answered by the test clearly points to the target population from which a representative sample must be obtained. 相似文献
157.
In this paper, we show that n ? 4 and if G is a 2-connected graph with 2n or 2n?1 vertices which is regular of degree n?2, then G is Hamiltonian if and only if G is not the Petersen graph. 相似文献
158.
159.
160.
The gas-phase high-resolution spectrum is reported for v1 of the linear molecule thioborine (HBS) from 2775 cm?1 to 2720 cm?1. Band centers and rotational constants are given for the 1000-0000 transitions of H11B32S, H10B32S, H11B34S and H10B34S and for the 1110-0110 transitions of H11B32S and H10B32S. A valence force field is determined from measured values of v1, Do (the centrifugal distortion) and q (the l-doubling constant). The remaining unobserved vibrational fundamentals are calculated from the force constants. 相似文献