Angiotensin-converting enzyme 2 protects from severe acute lung failure

Acute respiratory distress syndrome (ARDS), the most severe form of acute lung injury, is a devastating clinical syndrome with a high mortality rate (30-60%) (refs 1-3). Predisposing factors for ARDS are diverse and include sepsis, aspiration, pneumonias and infections with the severe acute respiratory syndrome (SARS) coronavirus. At present, there are no effective drugs for improving the clinical outcome of ARDS. Angiotensin-converting enzyme (ACE) and ACE2 are homologues with different key functions in the renin-angiotensin system. ACE cleaves angiotensin I to generate angiotensin II, whereas ACE2 inactivates angiotensin II and is a negative regulator of the system. ACE2 has also recently been identified as a potential SARS virus receptor and is expressed in lungs. Here we report that ACE2 and the angiotensin II type 2 receptor (AT2) protect mice from severe acute lung injury induced by acid aspiration or sepsis. However, other components of the renin-angiotensin system, including ACE, angiotensin II and the angiotensin II type 1a receptor (AT1a), promote disease pathogenesis, induce lung oedemas and impair lung function. We show that mice deficient for Ace show markedly improved disease, and also that recombinant ACE2 can protect mice from severe acute lung injury. Our data identify a critical function for ACE2 in acute lung injury, pointing to a possible therapy for a syndrome affecting millions of people worldwide every year.     

浅议工科院校经管类学生的能力培养

针对工科院校经管类专业学生能力培养方面较为薄弱的状况，论述了通过重视基础理论、加强工程背景、强调能力培养、开展技能培训等措施来改善学生能力培养与质量的必要性。     

Nanotube electronics: large-scale assembly of carbon nanotubes

Nanoscale electronic devices made from carbon nanotubes, such as transistors and sensors, are much smaller and more versatile than those that rely on conventional microelectronic chips, but their development for mass production has been thwarted by difficulties in aligning and integrating the millions of nanotubes required. Inspired by biomolecular self-assembly processes, we have created chemically functionalized patterns on a surface, to which pre-grown nanotubes in solution can align themselves in huge numbers. This method allows wafer-scale fabrication of millions of carbon-nanotube circuits with single-nanotube precision, and may enable nanotube-based devices, such as computer chips and high-density sensor arrays, to be produced industrially.     

Pseudo-isochromosomes in pearl millet

Summary Meiosis in a plant with 2n=12+2 pseudo-isochromosomes was studied. The pseudo-isochromosomes were compensating for the loss of the 3rd chromosome pair of the normal diploid complement.Acknowledgments. The authors are thankful to Dr J. Sybenga, for his helpful suggestions. The first 2 authors are thankful to the University Grants Commission, New Delhi, for financial assistance.     

Identification of two new metabolites of caffeine in the rat urine

Résumé L'acide 1, 3, 7-triméthyldihydro-urique et la 3, 6, 8-triméthylallantoïne ont été identifiés comme métabolites nouveaux de la cafféine dans l'urine de rat.     

Potassium levels in human semen with reference to sperm motility

Résumé Il est connu que la motilité et le métabolisme des spermes de mammifères sont sous influence des ions inorganiques, spécialement des ions de potassium. Nous avons étudié le contenu de potassium dans des échantillons de personnes fertiles et infertiles. Nous avons observé que les échantillons dont 30% de spermes étaient motiles, ont la teneur de potassium peu élevée. Les résultats indiquent que le potassium est un des constituants importants du plasma séminal et qu'il a une forte influence sur la motilité des spermes.     

在OA环境下TRANS-NET微机局部网络的功能开发及命令扩充

本文分四个部分。第一部分介绍了微机局部网络及其系统的基本概念;第二部分介绍了Trans——Net局部网络的主要性能及其功能;第三部分是全文的重点,这部分详细地叙述了在办公自动化(OA)环境下T——Net局部网络的应用、功能开发及扩充的十七条命令;第四部分以发文命令为例介绍了程序框图及其执行过程。