Red blood cell glutathione peroxidase in simple trisomy 21 and translocation 21/22

Summary Red blood cell glutathione peroxidase activity was increased by bbout 50% in all Down's syndrome patients studied. It was slightly lower in translocation as compared with simple trisomy 21 but much higher with respect to controls. We are indebted to Prof. M. Ferguson-Smith from the Department of Medical Genetics, Royal Hospital for Sick Children, Glasgow, Scotland, for helpful discussions regarding our results.     

面向21世纪的微电子技术

本文对21世纪微电子技术的发展趋势作了一个展望。本文认为21世纪初的微电子技术仍将以硅基CMOS电路为主流工艺，但将突破目前所谓的物理“限制”，继续快速发展；集成电路将逐步发展成为集成系统；微电子技术将与其他技术结合形成一系列新的增长点，例如微机电系统（MEMS）、DNA芯片等将得到突飞猛进的发展。具体地，超微细光刻技术、虚拟工厂技术、铜互连及低κ互连绝缘介质、高κ栅绝缘介质、SOI技术等将在近几年内得到快速发展。21世纪将是我国微电子产业的黄金时代。     

21世纪的神经科学研究

主要沿着还元论的研究路线,２０世纪神经科学的成就空前,主要借助于超分析和超综合的研究策略,２１世纪的社会科学研究可望在中枢神经系统活动的本质和工作原理、神经系统疾患的发生机制和诊治措施,以及人工智能领域取得更多更新的突破或进展。     

21世纪的新药发现:从基因到药物

随着人类基因线计划的实施将会发现越来越多的功能基因。从中了解到的生物信息对我们了解发病机制将提供很大的帮助，同时可进行广泛的人群遗传相关性和基因治疗研究，并可能发现新的药物作用靶，其取得的研究进展对疾病治疗的合理用药及新药的研究开发将产生深远的影响，未来将会看到更多的新药出现，但一定是随着新基因的发现而开始的。     

The synthesis of corticosteroids methylated at C21

Zusammenfassung Die Darstellung der beiden epimeren C₂₁-Methylderivate des 9-Fluorprednisolons wird beschrieben. 9-Fluor-21-methyl-1, 4-pregnadien-11, 17, 21B-triol-3, 20-dion-21-azetat ist ein hochwirksames entzündungshemmendes Steroid, vollkommen frei von Nebenwirkungen der Natrium- und Wasserretention des C₂₁-unsubstituierten 9-Fluorprednisolons.     

基因学(Genics)--未来的新兴学科

遗传学的发展是从Heredity(以生物外部表现型为主的数量遗传研究）→Genetics(以生物体内染色体为主的细胞遗传研究）→Genics(以染色体上核酸为主的分子遗传研究）,基因是研究的核心。在二十世纪,在理论方面,基因的结构、功能和概念不断扩展,由单基因→基因家庭→基因簇→同源框基因→基因组学,在应用方面,从基因工程→基因克 隆→转基因→基因沉默→基因流→转基因安全性的研究,有了飞跃性的发展。基因研究已渗透到各个科学领域,出现了后基因组学,功能基因组学,蛋白组学,功能蛋白组学,功能酶学,生物信息学,生物计算机,药物基因组学,疾病基因组学,工业基因组学,转基因（食品）安全性,基因流,环境基因学等新的基因研究方向。基因产业和基因经济将会成为二十一世纪经济发展的新生点。基因学将在二十一世纪走向更加成熟和完善。     

迈进二十一世纪的集成电路

文章讨论了进入二十一世纪微电子科学技术所面临的诸多问题：超微细加工新技术,高电导率金属和低介电常数介质的互连技术,SiCMOS工艺的限制以及GaAs集成电路的崛起等。     

Overexpression of copper-zinc superoxide dismutase in trisomy 21

Down's syndrome (DS), the most frequent of congenital birth defects, results from the trisomy of chromosome 21 in all cells of affected patients. This disease is characterized by developmental anomalies, mental retardation and features of rapid aging, particularly in the brain, where the occurrence of Alzheimer's disease is observed in trisomy 21 patients over the age of 35. Copper-zinc superoxide dismutase (CuZnSOD) is one of the proteins encoded by chromosome 21 (21q22.1). As a consequence of gene dosage excess, CuZnSOD activity is increased by 50% in all DS tissues. This work reports the SOD activity of a population of DS patients with complete trisomy 21, partial trisomy 21, translocations and mosaicism, in order to confirm the gene dosage effect of SOD on the clinical features of DS, and to help to establish which is the critical region of chromosome 21 in DS. CuZnSOD was measured in red blood cells using the Minami and Yoshikawa method. In the population with complete trisomy 21, SOD activity was increased by 42%; in the population with partial trisomy 21, translocations and mosaicism, SOD activity was normal. In the population diagnosed as DS, but not karyotyped, SOD activity was increased by 28%. No differences between sexes or among ages were found. We conclude that the 21q22.1 segment is not the critical region responsible for DS, as we have found normal SOD activity in patients with the clinical features of DS.     

21世纪南极科学研究展望

21世纪的南极科学研究更加强调多学科和全球化，更注意时间和空间尺度上突破。在突出研究南极地区在全球变化中的作用同时，加强对南极的监测和保护，关注人类活动对南极地区的影响。合理利用南极的资源尤其是生物资源也是21世纪列入各国南极研究的任务之一。     

21世纪初美国教育热点问题——“911事件”后美国教育的若干变化

进入21世纪后，特别是“911事件”以来，美国以独有的紧迫感，采取切实措施，大力提高基础教育和高等教育质量，努力培养具有爱国主义精神的新型人才，提高全球公民的科学文化素质。     

Effect of progesterone on human corticosteroid 21-hydroxylation.

Progesterone inhibits the 21-hydroxylation of 17alpha-hydroxyprogesterone by human adrenal cortex microsomes. The possible light this finding may shed on the genetic condition, the 'adrenogenital syndrome' is discussed. Km and Vmax data for the above hydroxylation reaction are given.     

空间天气学--21世纪的新兴学科

本文简要介绍空间天气及其对人类活动的影响空间天气和空间天气学的发展、空间天气国内外研究现状及开展空间天气研究与高科技发展的需求等等,然后对发展空间灾害性天气事件数值预报所涉及的问题阐述了作者的一些不成熟的看法。     

信息材料的跨世纪展望

本文回顾了信息技术的发展以及跨世纪的展望。介绍了与若干关键的技术,如信息处理、信息传递,信息存储,信息显示,信息获取以及激光和光功能相关的材料的发展。讨论了２１世纪信息材料产业的发展。     

超微金刚石--二十一世纪新材料

超微金刚石（ＵＦＤ）是爆炸力学与材料科学相结合的产物。建立了较完整的ＵＦＤ生成机理，建立了爆轰中游离碳聚结成液滴的直接蒙特卡洛方法计算、爆炸热力学条件计算和相变动力学计算程序；测定了ＵＦＤ的各种特性，论述了其应用及发展前景，认为ＵＦＤ兼具金刚石和纳米颗粒的两类特征，是二十一世纪新材料。     

Pathogenic enterococci: new developments in the 21st century

Enterococci, traditionally viewed as Gram-positive commensal bacteria inhabiting the alimentary canals of humans and animals, are now acknowledged to be organisms capable of causing life-threatening infections in humans, especially in the nosocomial environment. The existence of enterococci in such a dual role is facilitated, at least in part, by its intrinsic and acquired resistance to virtually all antibiotics currently in use. Beginning with the initial identification of a streptococci of fecal origin in the late 19th century, enterococci have been studied for over a century now. A number of comprehensive reviews during this time have addressed various aspects of enterococci, including classification, biology, virulence, antibiotic resistance and so on. This review specifically addresses the important advances in the field of enterococcal research that have occurred since the beginning of the 21st century. Most notable among these developments have been the insights into enterococcal genomes and pathogenicity.Received 10 April 2003; received after revision 31 May 2003; accepted 3 June 2003     

21世纪物理学发展展望

本文在回顾20世纪物理学主要进展的基础上，从五个方面对21世纪物理学的发展作了展望，论述了物理学研究的一些前沿学科和领域。     

ETT-引领21世纪的高速运输

19世纪汽车、火车的出现代替了马拉车，20世纪飞机的发明使运输速度比汽车和火车又提高10倍以上。20世纪60年代，有些研究机构通过理论分析，提出了最高速度可达到22500km/h的ETT－真空管运输系统的设想，即运输速度比普通飞机再提高10倍以上。自提出设想以来几十年过去了，建设ETT所需的工程技术，材料工艺，真空技术和自动控制技术等均已成熟，让我们肩负起历史的重托，积极投身到ETT项目的实践中去，迎接这场21世纪运输革命的到来。     

Increase of lymphocytic H-Y antigen in female 21-hydroxylase deficiency

Summary H-Y antigen was found to be increased in lymphocytes from 10 female 21-hydroxylase deficiencies, suggesting a correlation between the degree of virilization of these patients and their H-Y+lymphocytes proportions. Furthermore, these findings demonstrate the ability of a 46,XX female subject to produce, in some circumstances, an excess of H-Y antigen.