Physiologically Based Liver Modeling and Risk Assessment

Because of the inherent complexity of biological systems, there is often a choice between a number of apparently equally applicable physiologically based models to describe uptake and metabolism processes in toxicology or risk assessment. These models may fit the particular data sets of interest equally well, but may give quite different parameter estimates or predictions under different (extrapolated) conditions. Such competing models can be discriminated by a number of methods, including potential refutation by means of strategic experiments, and their ability to suitably incorporate all relevant physiological processes. For illustration, three currently used models for steady-state hepatic elimination--the venous equilibration model, the parallel tube model, and the distributed sinusoidal perfusion model--are reviewed and compared with particular reference to their application in the area of risk assessment. The ability of each of the models to describe and incorporate such physiological processes as protein binding, precursor-metabolite relations and hepatic zones of elimination, capillary recruitment, capillary heterogeneity, and intrahepatic shunting is discussed. Differences between the models in hepatic parameter estimation, extrapolation to different conditions, and interspecies scaling are discussed, and criteria for choosing one model over the others are presented. In this case, the distributed model provides the most general framework for describing physiological processes taking place in the liver, and has so far not been experimentally refuted, as have the other two models. These simpler models may, however, provide useful bounds on parameter estimates and on extrapolations and risk assessments.     

语气词在俄语口语中的结构功能

俄语传统语法历来认为语气词不充当句子成分,不发挥任何句法作用.然而,这种特性在口语中却发生了变化;有为数不少的语气词具有结构功能,在交际中发挥着极为重要的作用,这点在语气词研究中往往被忽视.受口语超语言特征的影响,语气词可以充当固定句位句素构成各种结构模式,表达各种情态意义.语气词发挥的结构功能主要有三大类:充当独立语句功能、充当语句结构要素功能及构成对话重复语句功能.     

关于广义Ramanujan-Nagell方程解数

设p是奇素数，D是适合p D是正奇数，证明了，当D≠Ap^r-1，其中r是正整数时，方程x^2 D=4p^n至多有1组正整数解（x,n）。     

资产证券化基本法律问题之探讨

资产证券化是 2 0世纪最重大的金融创新之一 ,它在中国的推行是必然的。但目前我国的资产证券化刚起步 ,实践经验贫乏和稀缺 ,有关理论也很模糊且存在颇多分歧 ,导致了建立资产证券化法律制度的工作因没有明确的指导原则和标准而滞后。本文暂不讨论资产证券化涉及的具体法律问题 ,而是在分析资产证券化的资产和证券的特点和范围之后 ,概括出资产证券化的法律内涵 ,在此基础上抽象出资产证券化法的价值 ,以期使资产证券化的基本法律问题引起更多思考     

世界贸易组织争端解决机制评析

从世界贸易组织（WTO）成立后的实践来看，它的争端解决机制为各成员方解决贸易争端、为帮助世界贸易秩序的稳定和发展发挥了重要作用。但是从对WTO争端解决机制的几个方面的具体的分析、评价中可以得知它也并非尽善尽美，还有待进一步的发展和完善。     

浅探杠杆收购战略在我国运用的可行性

企业购并是国外特别是美国企业成长和发展的一个重要手段。在一百多年的企业发展历史上,在完全市场经济的条件下,美国企业、金融界进行了大量的创新,开发了丰富的金融工具。其中杠杆收购战略就是创新工具的一个典型例子。尽管我国开始市场经济的时间较短,但是金融界和政府部门一直在改革和创新具有中国特色的金融市场。探讨杠杆收购战略在我国运用的可行性,可以为我国的企业购并注入新的活力。     

危机与改革——国际田联现状分析

为了更有效地推动田径的发展 ,国际田联应致力于组织机构、比赛项目设置、裁判规则与手段等方面的研究与改革 ,加大反兴奋剂的力度 ,并努力消除与国际奥委会和其他国际体育组织之间的冲突     

诗意的批判--论萧红小说的反讽叙事

反讽叙事在萧红的小说中是进行国民性批判的主要叙事策略,这种对反讽的自觉运用使作者以一种更具审美性的方式含蓄而诗意地表现国民性批判的意图,同时也是萧红小说语言诗化特点形成的原因之一。反讽机制的运用使萧红的小说叙事实现了对现实世界和人性世界的深层揭示和哲学反思。     

试论国有企业改革中的人力资源管理

本文从三个方面论述国有企业改革中的人力资源管理的必要性、重要性、变革思路,①知识经济时代要求企业增强人力资源意识;②人力资源是企业增强核心竞争力的关键;③重点从五个方面阐述国有企业人力资源管理变革的思路,即把人作为资源进行开发利用;建设高新技术产业人才发展工程;加大人力资本投资力度,全面提高人才素质;建立企业"人才仓库";建立精干、高效的人力资源管理部门,强化人力资源的管理职能.     

AN ALGORITHM FOR THE CONSTRUCTION OF OPTIMAL OR NEAR-OPTIMAL CHANGE-OVER DESIGNS

This paper presents an algorithm for the construction of optimal or near optimal change-over designs for arbitrary numbers of treatments, periods and units. Previous research on optimality has been either theoretical or has resulted in limited tabulations of small optimal designs. The algorithm consists of a number of steps:first find an optimal direct treatment effects design, ignoring residual effects, and then optimise this class of designs with respect to residual effects. Poor designs are avoided by judicious application of the (M, S)-optimality criterion, and modifications of it, to appropriate matrices. The performance of the algorithm is illustrated by examples.