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81.
Baell JB Forsyth SA Gable RW Norton RS Mulder RJ 《Journal of computer-aided molecular design》2001,15(12):1119-1136
Our interest lies in the rational design and synthesis of type-III mimetics of protein and polypeptide structure and function. Our approach involves interactive design of conformationally defined molecular scaffolds that project certain functional groups in a way that mimics the projection of important binding residues as determined in the parent structure. These design principles are discussed and applied to the structurally defined polypeptide, -conotoxin GVIA, which blocks voltage-gated, neuronal N-type calcium channels. These ion channels represent therapeutic targets for the development of new analgesics that can treat chronic pain. It is shown how a discontinuous, 3-residue pharmacophore of GVIA can be mimicked by different molecular scaffolds. It is illustrated how such 1st generation leads must necessarily be weak and that optimisability must therefore be built-in during the design process. 相似文献
82.
Joyce MJ Sharpey-Schafer JF Twin PJ Beausang CW Cullen DM Riley MA Clark RM Dagnall PJ Deloncle I Duprat J Fallon P Forsyth PD Fotiades N Gale SJ Gall B Hannachi F Harissopulos S Hauschild K Jones PM Kalfas CA Korichi A Le Coz Y Meyer M Paul ES Porquet MG Redon N Schuck C Simpson J Vlastou R Wadsworth R 《Physical review letters》1993,71(14):2176-2179
83.
Determination of butyltin, methyltin and tetraalkyltin in marine food products with gas chromatography-atomic absorption spectrometry 总被引:1,自引:0,他引:1
Extraction methods were developed for the determination of butyltin, methyltin and tetraalkyltin in marine food products. Alkyltins were complexed with either diphenylthiocarbazone (dithizone) or tropolone from enzymatically hydrolysed samples. Tetraalkyltins were extracted with hexane. Butyl or methyl derivatives of the alkyltins were made by Grignard reaction for analysis by gas chromatography-atomic absorption spectrometry. Many of the examined marine food products contained ppb levels of alkyltins. Tetramethyltin and tetraethyltin levels were less than the method detection limits of 0.8 and 0.7 ng/g (as Sn), respectively. 相似文献
84.
85.
Yu-Ming ZHENG Hong-Min LIU Ben-Hao SA Zhong-Dao LU Zhong-Qi WANG Xiao-Ze ZHANG 《理论物理通讯》1993,19(1):71-74
A simple Monte Carlo simulation and even a partition method can be used to reproduce quite well the power law behavior between the factorial moment and the charge interval of fragment charge distributions from the multifragmentation of 197Au nucleus bombarding emulsion at~1 GeV/nucleon. This indicates that the above power law seems not to be a unique precursor of the intermittent behavior in nuclear multifragmentations. 相似文献
86.
Following the method developed by the authors,recently,the equation of state of hot nuclei(238U in concrete) before break-up was investigated numerically.The isotherms are drawn in the plan of the general pressure P versus volume VRT. They are similar to those of Van der Waals gas.The critical temperature of phase transition should correspond to the isotherm with one turning point only.It turns out that the data of mass yield distribution can be reproduced by many pairs of parameters T and VRT (freeze-out temperature and freeze-out volume) varying in certain range.For each isotherm (each T),the data are always best reproduced by the value of VRT located at the maximum general pressure within two phases coexistence region. 相似文献
87.
88.
Summary In recent years spatially resolved ESCA techniques have become increasingly popular for the analysis of samples with structured surfaces. The chemical information available in ESCA is highly important in surface analysis and there is a great need to realise this information in an imaging mode. The method of parallel imaging ESCA was first implemented on the VG Scientific ESCASCOPE and has more recently been developed for the ESCALAB 220i range of instruments. The Fourier transform electron optics used on these instruments provides the flexibility of real time or accumulated imaging along with the highest spatial resolution ever achieved. Some examples are shown exhibiting image resolution better than 2 microns and spectroscopy from an area of 15 microns (classically defined as a spatial resolution of about 7.5 microns). The use of a focussed monochromator in conjunction with the imaging facility allows fast chemical state imaging. An example of this is shown. 相似文献
89.
H. Windcliff J. Wang P.A. Forsyth K.R. Vetzal 《Journal of Computational and Applied Mathematics》2007
Hedging a contingent claim with an asset which is not perfectly correlated with the underlying asset results in unhedgeable residual risk. Even if the residual risk is considered diversifiable, the option writer is faced with the problem of uncertainty in the estimation of the drift rates of the underlying and the hedging instrument. If the residual risk is not considered diversifiable, then this risk can be priced using an actuarial standard deviation principle in infinitesimal time. In both cases, these models result in the same nonlinear partial differential equation (PDE). A fully implicit, monotone discretization method is developed for solution of this pricing PDE. This method is shown to converge to the viscosity solution. Certain grid conditions are required to guarantee monotonicity. An algorithm is derived which, given an initial grid, inserts a finite number of nodes in the grid to ensure that the monotonicity condition is satisfied. At each timestep, the nonlinear discretized algebraic equations are solved using an iterative algorithm, which is shown to be globally convergent. Monte Carlo hedging examples are given to illustrate the profit and loss distribution at the expiry of the option. 相似文献
90.
Deacon GB Forsyth CM Behrsing T Konstas K Forsyth M 《Chemical communications (Cambridge, England)》2002,(23):2820-2821
The syntheses and structures of the novel Ce-Fe bimetallic complexes [[Fe(sal)2(bpy)]2Ce(NO3)(H2O)3].EtOH and [[Fe(sal)2(bpy)]4Ce2(H2O)11][salH]2.EtOH.3H2O (salH2 = salicylic acid) suggest Fe(3+)-sal2- units and Ce-OC(R)O-Fe bridging contribute to the formation of corrosion inhibitive layers on steel surfaces exposed to [Ce(salH)3(H2O)]. 相似文献