紫杉醇类似物抗癌活性构效关系的神经网络模式识别研究

经对MM3、MM＋、MNDO、PM3几何优化结果进行比较，选用速度最快且精确度较好的MM3分子力学方法计算43个紫杉醇类似物的优势构型，应用MNDO法计算了化合物的电子结构，并用回归分析和BP神经网络模式识别方法寻找其电子结构与抗癌活性的关系．结果表明：（1）紫杉醇类似物及C13侧链的油水分配系数与活性参数问呈抛物线关系，最适油水分配系数Popt=3．14；（2）2-OBz中Bz基团的负电荷密度越大，C1、C3原子的正电荷密度越大对活性越有利；（3）R1、R2、1-OH和2-OBz基团可能是药物与受体作用的重要部位．四参数的定量构效关系显著性较好，神经网络模式识别总识别率为98％，可较精确地预测化合物的抗癌活性．     

拓扑指数法在QSPR研究中的应用

目前拓扑指数方法在定量构效关系(QSPR)研究中属活跃领域。简述了Wiener指数、Ran dic-Kier指数、Hosoya指数等拓扑指数,介绍了拓扑指数在定量构效关系研究、物化性质研究、药物设计研究、环境污染预测等方面的应用。表明拓扑指数法在QSPR研究中取得显著效果,具有良好的应用前景和实用价值。     

N，N，N-三（2-甲基苯并咪唑）胺及其稀土配合物的合成与荧光性质研究

为了考察三脚架配体及其稀土配合物的配住形式和性质，从而为进一步研究其荧光性质、生物活性提供依据，以氨三乙酸为母体合成了N，N，N-三（2-甲基苯并咪唑）胺及其稀土配合物（La^3＋，Sm^3＋，Y^3＋,Tb^3＋,Ce^3＋，Eu^3＋）．通过红外、核磁共振、差热-热重、紫外及荧光等分析手段研究了配体及其配合物的结构关系和荧光性质．研究表明。谊类配体是较好的主体分子。能够与稀土离子发生配位，形成配合物，配合物内界的NO3^-以双齿形式与中心离子配位；配合物热稳定性好，具有较好的荧光性质，特别是Tb^3＋配合物是高效的稀土有机发光配合物，可用于荧光材料的研究．     

橡胶类材料大应变硬化的本构关系

橡胶材料具有良好的弹性性能和拉伸能力,为典型的超弹性材料．其在大应变时常呈现出应力一应变的增强或软化效应,本构关系较复杂．目前,有关橡胶材料大应变硬化的本构关系实验研究尚属匮乏．文中对橡胶类材料大应变时的硬化现象进行了实验和理论研究,提出了一种新的应变能函数来描述橡胶材料的本构关系,测定了橡胶材料硬化时的本构参数,并进行了实验验证．研究结果表明该应变能函数可较好地描述橡胶材料在大应变时的硬化现象,为进一步研究橡胶材料硬化的本构特性提供了参考依据．     

抗癌药物α,β不饱和羰基化合物3D-QSAR研究

采用CoMFA和CoMSIA方法对31个α,β不饱和羰基化合物进行了三维定量构效关系研究,所得模型都具有良好统计学意义.CoMFA:q~2=0.687,R~2=0.956,N=9,SEE=0.090;CoMSIA:q~2=0.756,R2=0.954,N=9,SEE=0.093.通过三维等值图分析其影响抑制剂分子的活性因素,并设计出了新的活性较高抑制性分子.     

新烟碱型乙酰胆碱受体吡啶基醚类配体的3维定量构效关系

采用比较分子力场分析方法，对一系列与烟碱型乙酰胆碱受体作用的吡啶基醚类配体进行构效关系分析，建立了这类化合物的3维构效模型．其交叉验证回归系数Rcv^2、非交叉验证回归系数Rncv^2和标准偏差s分别为0．744，0．973和0．256．结论说明该系列化合物的分子立体场和静电场的分布与生物活性之间有良好的相关性．该模型对训练集分子的活性预测结果较好，表明该力场模型有一定的预测能力，可用来指导设计新的烟碱型乙酰胆碱受体配体．     

基于配体姜黄素的3D-QSAR研究进展

在药物设计合成过程中计算机辅助药物设计已经成为一种不可或缺的工具,其中,三维定量构效关系方法的应用最为广泛.文章简要介绍了姜黄素的研究进展,重点介绍计算机辅助药物设计的原理方法,综述了三维定量构效关系在药物设计中的应用,分析了三维定量构效关系在指导姜黄素类似物设计合成方面的现状,对3D-QSAR方法指导设计姜黄素类似物合成进行了展望,同时指出计算机辅助药物设计存在的一些问题.     

基于谱效关系的灰色关联度分辨系数确定

在中药指纹图谱的相关研究中,谱效关系是目前研究的一个重点和热点．谱效关系的研究可以为中药的国际化,现代化提供良好途径．文章对一种常用的关联度计算方法——灰色关联度进行了研究,给出了一种新的确定分辨系数方法,避免了人为主观选取分辨系数对实验结果带来的干扰．实证研究表明,新方法具有良好的效果．     

定量构效关系研究进展及其应用

定量构效关系是目前国际上一个比较活跃的研究领域.本文简要介绍了定量构效关系的发展历史及定量构效关系研究中常用方法等,其中较为详细地介绍了三维定量构效关系中广泛应用的CoMFA方法.综述了定量构效关系在环境污染物分析以及在农药、医药设计中的应用,并对定量构效关系研究的发展趋势进行了展望.     

一类新型罗非昔布开环衍生物抗炎构效关系

用PM3半经验量化方法优化了一类新型罗非昔布(RC)开环衍生物与RC的几何构型;对其中11个化合物搜寻和计算了它们的结构参数,采用多元逐步回归分析方法,建立了经典结构活性关系(2D-QSAR);并用SOM-FA2软件分析了全部化合物的3D-QSAR关系。结构优化表明活性RC开环衍生物具有类似RC的立体结构,构效关系研究也表明该类新型RC开环衍生物具有其它环氧合酶选择性抑制剂相似的构效关系。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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