Small heat shock proteins: molecular structure and chaperone function

Small heat shock proteins (sHSPs) associate with nuclei, cytoskeleton and membranes, and as molecular chaperones they bind partially denatured proteins, thereby preventing irreversible protein aggregation during stress. sHSP monomers consist of a conserved α-crystallin domain of approximately 90 amino acid residues, bordered by variable amino- and carboxy-terminal extensions. The sHSPs undergo dynamic assembly into mono- and poly-disperse oligomers where the rate of disassembly affects chaperoning. The α-crystallin domain contains several β-strands organized into two β-sheets responsible for dimer formation, the basic building block of most sHSPS. The amino-terminal extension modulates oligomerization, subunit dynamics and substrate binding, whereas the flexible carboxy-terminal extension promotes solubility, chaperoning and oligomerization, the latter by inter-subunit linkage. Crystallization studies have revealed sHSP structure and function. Additionally, site-directed mutagenesis, biophysical investigations, functional studies and the discovery of relationships between mutated sHSPs and diseases have illuminated the role of sHSP within cells. Received 8 May 2005; received after revision 24 June 2005; accepted 19 July 2005     

乘法半群为矩形群的nil扩张的半环

研究了加法半群为半格、乘法半群为矩形群的nil扩张的半环，从半环的子集出发构造乘法半群上的关系，得到H-为半环(Reg(S),+,·)上同余关系的充要条件，给出了矩形群的nil扩张转化为矩形带的nil扩张条件，并将矩形群的nil扩张性质推广到矩形带的nil扩张和矩形群上。     

h强竞赛图的得分向量和单扩张

在竞赛图得分向量分类的基础上解决h强竞赛图得分向量问题.同时,讨论了h强竞赛图的单扩张和次弧泛圈性.     

群中心扩张与二维上同调群通用系数定理

本文在Ｇｒｕｅｎｂｅｒｇ中给出了范畴之中心自由对象构作基础上进行群Ｇ中心扩张构作，使用覆盖及衍生同态ψＥθ为中心自由扩张，文中称作普适覆盖扩张，Ｅ是Ａｂｅｌ群Ａ经群Ｇ的中心扩张。定理１指出ｆ是一个二因子次直接和，尽管非交换，因子之一为Ｖ经Ｈ１（Ｇ）的交换扩张，另一是Ｇ的本盖扩张，二是者上交于因子群Ｈ１（Ｇ）。     

Beurling-Ahlfors扩张伸缩商的上界估计

设h(x)是实轴上的保向同胚,满足h(±∞)=±∞.当h(x)的拟对称函数(,)()()()()x th x t h xρ=h x+?h?x?t(x∈R,t>0)被递减函数ρ(t)所控制时,h(x)的Beurling-Ahlfors扩张的伸缩商D(z)具有下述估计:21 1D≤ρ?+ρ??2,其中()2ρ?=ρy.     

α-斜线性McCoy环的扩张性质

研究了α-斜线性McCoy环与相关环的关系,以及它的一些扩张性质.     

Unramified extensions of quadratic fields

Let K be a global quadratic field, then every unramified abelian extension of K is proved to be absolutely Galois when K is a number field or under some natural conditions when K is a function field. The absolute Galois group is also determined explicitly.     

Beurling-Ahlfors延拓的伸张函数之估计

研究实轴R^1上的保向同胚映照到上半平面Beurling—Ahlfors延拓的伸张函数的性质．通过证明几个不等式,对伸张函数D(z)作进一步的估计．改进了相关的结果．     

Beurling-Ahlfors扩张的伸张函数的边界极限

设h(χ)是实轴R到自身的同胚,讨论h(χ)的Beurling-Ahlfors扩张的伸张函数在实轴附近的性质,指出一个现有结果的错误并得到新的结果．     

含k-布尔环的半单类的结构定理

借助给出环的超裂零扩张的定义的手法,对遗传根的半单类的结构进行了研究,主要得出含k-布尔环的半单类的结构定理,证明了若遗传根的半单类S_R包含所有的k-布尔环(k是某个固定不变的整数)以及所有零环,而且S_R对k-布尔理想保持同态闭,则S_R包含所有布尔环。