Segmented polyurethane: a new elastomer for biomedical applications

A segmented polyurethane elastomer, originally developed for elastic thread, is now being used for molded prostheses. Performance of this material when used for components of a heart-assist system warrants a thorough investigation of its effectiveness in a variety of biomedical devices.     

Biodegradable, elastic shape-memory polymers for potential biomedical applications

The introduction of biodegradable implant materials as well as minimally invasive surgical procedures in medicine has substantially improved health care within the past few decades. This report describes a group of degradable thermoplastic polymers that are able to change their shape after an increase in temperature. Their shape-memory capability enables bulky implants to be placed in the body through small incisions or to perform complex mechanical deformations automatically. A smart degradable suture was created to illustrate the potential of these shape-memory thermoplastics in biomedical applications.     

A policy for investment in biomedical research

Given a continuation of the current approach toward the managing and funding of research across the spectrum of disciplines basic to health, the country is headed for stultification and possible social disaster. Health care delivery should be considered as a science-based social industry and managed accordingly. Stability and adequate relation of the research effort to the industry's output should be sought. The establishment of a trust fund, derived as a percentage of health revenues, and of a public commission or a board of directors to provide expert advice on its expenditures are suggested.     

Research funding. Windfall for French biomedical agency

Researchers at France's giant biomedical research agency, INSERM, are rejoicing over a 16% hike in the organization's research budget for 2001. The windfall, announced by INSERM director-general Claude Griscelli last week, is the biggest such increase since 1983.     

Third-generation biomedical materials

Whereas second-generation biomaterials were designed to be either resorbable or bioactive, the next generation of biomaterials is combining these two properties, with the aim of developing materials that, once implanted, will help the body heal itself.     

Designing small-molecule switches for protein-protein interactions

Mutations introduced into human growth hormone (hGH) (Thr175 --> Gly-hGH) and the extracellular domain of the hGH receptor (Trp104 --> Gly-hGHbp) created a cavity at the protein-protein interface that resulted in binding affinity being reduced by a factor of 10(6). A small library of indole analogs was screened for small molecules that bind the cavity created by the mutations and restore binding affinity. The ligand 5-chloro-2-trichloromethylimidazole was found to increase the affinity of the mutant hormone for its receptor more than 1000-fold. Cell proliferation and JAK2 phosphorylation assays showed that the mutant hGH activates growth hormone signaling in the presence of added ligand. This approach may allow other protein-protein and protein-nucleic acid interactions to be switched on or off by the addition or depletion of exogenous small molecules.     

Biomaterials and biomedical devices

This review discusses the factors important in the incorporation or integration of biomaterials and devices by tissue. Methods for surface modification and surface-sensitive techniques for analysis are cited. In vitro methods to evaluate the biocompatibility or efficacy of certain biomaterials and devices are presented. Present and future directions in neural prostheses, cardiovascular materials, blood or bone substitutes, controlled drug delivery, orthopedic prostheses, dental materials, artificial organs, plasma- and cytapheresis, and dialysis are discussed.     

关于我国股指期货设计方案的几点建议

本文主要阐述了作者对我国股指期货设计方案的一些看法。关于指数选择问题，本文认为不宜将现有的股价指数直接作为期货合约的交易基础，而应在对沪深两地现有成分股指数进行调整的基础上合成一个新指数:关于期货合约的设计，木文认为在确定乘数，最小波动点，合约交割月份，保证金水平及侮日涨跌幅限制时，既要参考发达国家的经验，又要结合我国的国情:关于交易场所的选择，本文认为上海期货交易所应是首选。     

生物医学实体关系抽取的研究

人类基因组计划使生物医学的研究取得了前所未有的成就,在研究结果中得到了大量的生物医学实体,如基因、蛋白质、器官、疾病和药物等,但这些生物实体之间存在什么样的关系仍不完全清楚。作为生物医学研究成果载体的文献呈指数增长,已成为科研人员获取知识的瓶颈。文本挖掘能够解决信息超载问题,故对生物医学实体关系的挖掘流程和评价指标进行介绍,对生物医学文本挖掘在研究生物实体关系抽取中采用的基于统计的方法、基于自然语言处理的方法和基于模式匹配的方法进行了阐述,对各种方法进行了综合比较,同时介绍了国内外相关研究。