人们研究药物的中心问题是揭示药物的化学结构、理化性质与生物活性之间的内在 联系。19世纪中叶就有人提出了它们的定量关系式: =F(C)(式212) 式中和C分别表示化合物的生物效应和结构性质。后来, Me yer和 Overton的研究表 明,一些化合物的脂水分配系数与麻醉作用呈线性关系

药物代谢在药学领域中,已日益成为一个重要的组成部分。通过对药物代谢的研究, 人们能从定性、定量及动力学方面了解药物在体内的活化、去活化、解毒及产生毒性的 过程。对于药物化学家来讲,通过对药物代谢原理和规律的认识,能合理地设计新药, 指导新药的研究和开发

对人体而言,绝大多数药物是一类生物异源物质 (Xenobiotics)。当药物进入机体后,一方面药物对机体产生诸 多生理药理作用,即治疗疾病;另一方面,机体也对药物产生 作用,即对药物的吸收、分布,排泄和代谢。药物代谢既是药 物在人体内发生的化学变化,也是人体对自身的一种保护机能

药物的第相生物转化是指体内各种酶对药物分子进行的官能团化反应,主要发生在药物分子的 官能团上,或分子结构中活性较高、位阻较小的部位,包括引入新的官能团及改变原有的官能团。本 节讲授的主要内容包括氧化反应、还原反应、脱卤素反应和水解反应

Earth's Internal Structure When a meteorite impacts a planet or moon, its energy of motion (called kinetic energy)is transformed into heat energy. As Earth grew larger and larger from continual impacts, its temperature increased. Radioactive decay of materials like uranium, thorium and potassium also added heat

Unit Four The Multicultural Society Reference Book: (New) Integrated Coursey as a collage Student's and Teaching's Book Teaching Method: Explanation Combination Objectives 1 grasp the main idea and structure of the text 2 practice their critical thinking ability

Unit One Fighting with the Forces of nature Texta the Icy Defender Reference Book:(New) Integrated Course 4 Student's and Teaching,'s Book Teaching Method: ESA(engage, study, activate 1 grasp the main idea and structure of the text

3.064Quiz10/10/03 Sample questions 1. What is the glass transition temperature of a polymer How can it be measured? What molecular characteristics determine its value Illustrate by giving the chemical structure and Tg for polyethylene polyvinyl chloride and polystyrene

Law is omnipresent in modern society and legal institutions have a major place in the structure of Westem societies. Law and legal process are increasing enormously Law seems to be a kind of replacement, a substitute for traditional authority. The same goes for the Netherlands there is a great deal of litigation. However, we should not exaggerate: we cannot say that a

1. The ownership structure of a business includes the following forms: A. Individual, group, corporate. B. Sole proprietorship, partnership, or corporation D. Debtors, creditors, and ownesancia C. Service, manufacturing, and financial. 2. Which of the following is NOT true concerning a sole proprietorship? A. A sole proprietorship is a company