Energetic landscape of alpha-lytic protease optimizes longevity through kinetic stability.

During the evolution of proteins the pressure to optimize biological activity is moderated by a need for efficient folding. For most proteins, this is accomplished through spontaneous folding to a thermodynamically stable and active native state. However, in the extracellular bacterial alpha-lytic protease (alphaLP) these two processes have become decoupled. The native state of alphaLP is thermodynamically unstable, and when denatured, requires millennia (t1/2 approximately 1,800 years) to refold. Folding is made possible by an attached folding catalyst, the pro-region, which is degraded on completion of folding, leaving alphaLP trapped in its native state by a large kinetic unfolding barrier (t1/2 approximately 1.2 years). alphaLP faces two very different folding landscapes: one in the presence of the pro-region controlling folding, and one in its absence restricting unfolding. Here we demonstrate that this separation of folding and unfolding pathways has removed constraints placed on the folding of thermodynamically stable proteins, and allowed the evolution of a native state having markedly reduced dynamic fluctuations. This, in turn, has led to a significant extension of the functional lifetime of alphaLP by the optimal suppression of proteolytic sensitivity.     

氯化铝工业生产中几个工艺技术问题的探讨

本文详细论述了利用废铝生产氯化铝过程中,设备及各控制因此对产品质量和颗粒度的影响,(?)了适宜的控制条件和设计要求,为生产不同用户需求的合格产品提供了可靠的依据。     

Comparative study of the karyotypes of two Egyptian species of bats,Taphozous perforatus andTaphozous nudiventris (Chiroptera: Mammalia)

A detailed karyotypic analysis of two Egyptian species of bats,Taphozous perforatus andTaphozous nudiventris, was made on the basis of conventional data and G-band patterns. No detectable karyotypic difference was found between the two species (2n=42, F.N. 64). By comparison of G-band patterns, some differences between the two species were seen in the corresponding autosomal pairs. These results are reported for the first time in Egypt.     

浅谈高等医学院校物理实验室管理与建设

确立实验技术人员的地位和作用,加强对其综合素质进行培养;努力改善实验教学环境和条件,建立完善的制度,是高等医学院校物理实验室建设管理的重要环节.本文结合我校实际谈一些体会.     

Indoxyl derivatives of drug metabolites

Summary Indoxyl derivatives were detected as minor products among the urinary metabolites of two trial drugs, a benzodiazepine (GP 55 129) and a benzophenone (CGP 11 952). Their structures were elucidated by NMR and mass spectroscopy. Presumably, metabolites containing potential aldehyde functions react spontaneously with endogenous indoxyl. Such derivatives have not hitherto been encountered in drug metabolism.     

独立数≤5的3-边连通简单图的上可嵌入性

结合边连通度，本文探讨了3-边连通简单网的独立数与上可嵌人性的关系，我们得到了下列结果：设G是一个3-边连通简单图，α（G）是G的独立数，若α／（G）≤5，则G是上可嵌入的，同时我们又得到了两个在3-边连通意义下最小的非上可嵌入图例．     

新世纪图书馆员社会角色转换研究综述

就近几年图书馆界关于新世纪馆员意识转换及社会角色转换等方面的研究进行了综述，指出新时期的馆员要实现自我社会角色的转换，首先是要明确转换的必要性，然后采取有效的策略逐步地、系统地推进转换，才能取得较好的效果。     

Study on the Elasticity-Plasticity-Stickiness of the Railway Crushed Stone Ballast

This paper is mainly aimed at the mechanics characteristic elas of ticity-plasticitystickiness existed in the CWR (continuously welded rails) track plane of the railway crushed stone ballast. As an important mechanics parameter of the CWR track plane, the ballast resistance is mainly influenced by this mechanics characteristic. Through the systematic experimental research and the theoretical analysis, this mechanics characteristic of the ballast resistance is revealed and a reasonable theoretical model is built for it. This study set a sound foundation for further studying the CWR track deformation property. It will be beneficial to the development of high-speed railway in China.     

高温多雨地区高等级沥青路面材料的分析与应用措施

针对南方高温多雨地区的气候特点 ,为解决沥青混凝土路面修筑后的高温稳定性和水稳定性这两个突出的问题 ,依据本单位的一个工程实践 ,从集料、沥青、级配设计、施工工艺等方面进行了系统的分析与阐述。说明高温多雨地区高等级沥青路面只要材料科学选择、严格控制、应用措施得当 ,质量是能够达到规范要求的