Three-stage designs for monitoring clinical trials

Optimal three-stage designs with equal sample sizes at each stage are presented and compared to fixed sample designs, fully sequential designs, designs restricted to use the fixed sample critical value at the final stage, and to modifications of other group sequential designs previously proposed in the literature. Typically, the greatest savings realized with interim analyses are obtained by the first interim look. More than 50% of the savings possible with a fully sequential design can be realized with a simple two-stage design. Three-stage designs can realize as much as 75% of the possible savings. Without much loss in efficiency, the designs can be modified so that the critical value at the final stage equals the usual fixed sample value while maintaining the overall level of significance, alleviating some potential confusion should a final stage be necessary. Some common group sequential designs, modified to allow early acceptance of the null hypothesis, are shown to be nearly optimal in some settings while performing poorly in others. An example is given to illustrate the use of several three-stage plans in the design of clinical trials.     

Unifying CRM and EWOC designs for phase I cancer clinical trials

The main goal of phase I cancer clinical trials is to determine the highest dose of a new therapy associated with an acceptable level of toxicity for the use in a subsequent phase II trial. The continual reassessment method (CRM) [O’Quigley, J., Pepe, M., Fisher, L., 1990. Continual reassessment method: a practical design for phase I clinical trials in cancer. Biometrics 46, 33–48] and escalation with overdose control (EWOC) [Babb, J., Rogatko, A., Zacks, S., 1998. Cancer phase I clinical trials: efficient dose escalation with overdose control. Statist. Med. 17 (10), 1103–1120] are two model-based designs used for phase I cancer clinical trials. A few modifications of the (original) CRM and EWOC have been made by many authors. In this paper, we show how CRM and EWOC can be unified and present a hybrid design. We study the characteristics of the approach of the hybrid design. The comparisons of the three designs (CRM, EWOC, and the hybrid design) are presented by convergence rates and overdose proportions. The simulation results show that the hybrid design generally has faster convergence rates than EWOC and smaller overdose proportions than CRM, especially when the true maximum tolerated dose (MTD) is above the mid-level of the dose range considered. The performance of these three designs is also evaluated in terms of sensitivity to outliers.     

不断改革教学方法,努力提高实验课质量

本文针对学生的实际问题,联系实际,在植物生理学实验的教学过程中,不断改进教学方法,并介绍了提高实验课质量的具体做法。     

加强临床实验室建设 促进和谐医院的构建

构建和谐医院既是建设社会主义和谐社会的本质要求,也是新时期医院生存和发展的重要条件。构建和谐医院就是要构建和谐的医患关系、和谐的医疗手段和和谐的医院文化。以人为本、人性化管理和实施医院管理年活动是加强医院管理,建设和谐医院的两个主要手段。临床实验室在和谐医院构建中发挥重要作用,这主要通过全面的实验室质量管理和优质的人性化服务来实现。     

文化与基因有无联系?——现代达尔文主义进军社会领域的思想轨迹

文化与基因是否有关系?达尔文的进化论与社会人文科学的关系如何?解决这些问题,就需要从达尔文主义入手,进而研究达尔文主义与"社会达尔文主义"和种族主义的根本差别,显然,达尔文主义进入人性和道德等领域过程中出现的动物行为学、社会生物学和进化心理学等学科,扩展了人们关于人自身的认识,对人文社会科学的发展具有推动作用。但也留下一系列不能简单地用基因与文化的直接关系来解决的难题。为了解决这些问题,需要对人类的行为模式和心理机制作深入科学的、历史的研究。     

模具虚拟实验室的研究与开发

针对传统模具培训资源存在的问题,提出了模具虚拟实验室的构想。主体功能包括模具结构认知、拆装实训和运动仿真3大模块,其中的特色功能有：模具知识立体词典、查看标准部件、自主拆装、实训考核等。基于在模具设计和分析方面广泛应用的UG软件,开发了模具教学虚拟实验室,实现了交互式的实训和知识关联,可广泛应用于模具人才培训,以及模具企业知识管理。     

实验室管理体制的改革与实践

分析了我校实验室管理体制上存在的体制滞后、实验课体系不健全、工作缺乏量化机制等问题,提出了实验室必须独立设置,成立实验中心,切实加强实验室统一管理、统一建设,实现实验资源优化、资源共享的构想,探讨了建立全新高效的实验室管理体系和规范化管理模式。     

“矿山地理信息系统建设”大学生创新实验室方案

为了给采矿工程专业、地理信息系统专业学生提供实训教学的更多机会,提出了进行＂矿山地理信息系统建设＂大学生创新实验室建设的方案,从实验室运作模式、实验室主要研究方向的角度进行了阐述,实验室的建立必将为采矿工程、地理信息系统专业就业以及创业奠定基础。     

新建本科院校实验室的建设与管理

针对目前新建本科院校实验室建设与管理中存在的问题进行分析,提出了解决问题的基本对策:更新高等教育理念,加强顶层设计,按照"集中建设、统一管理、提高效率、全面开放、资源共享"的原则进行规划,建章立制,以加强实验室软条件建设促进实验室的规范管理,保证实验室可持续健康发展。     

当代生物学中的非线性因果观

随着当代自然科学尤其是生物学在微观领域的研究 ,传统的线性因果观受到了巨大的冲击 ,大量的生物学现象表现出的是一种非线性的关系。当代生物学的研究对非线性因果关系影响重大 ,遗传科技的发展对因果必然性的重新认识起了重要作用。从哲学层面上看 ,遗传决定论是对因果必然性的一种误区