The expression levels of three raft-associated molecules in cultivated vascular cells are dependent on culture conditions

Relaying a signal across the plasma membrane requires functional connections between the partner molecules. Membrane microdomains or lipid rafts provide an environment in which such specific interactions can take place. The integrity of these sites is often taken for granted when signalling pathways are investigated in cell culture. However, it is well known that smooth muscle and endothelial cells undergo cytoskeletal rearrangements during monolayer culturing. Likewise affected – and with potentially important consequences for signalling events – is the organization of the plasma membrane. The expression levels of three raft markers were massively upregulated, and raft-associated 5-nucleotidase activity increased in conventional monolayer cultures as compared with a spheroidal coculture model, shown to promote the differentiation of endothelial cells. Our data point to a shift of raft components in monolayer cultures and demonstrate potential advantages of the spheroid coculture system for investigation of raft-mediated signalling events in endothelial cells.Received 4 August 2003; received after revision 18 September 2003; accepted 25 September 2003     

YACC在Aim-16微型机上实现的方法

本文分析了YACC的可移植性和MP/M-86的特性后,成功地将YA-CC移植到Aim-16微型计算机上,为Aim-16机新开发了一个有效的软件开发工具,增强了Aim-16微机的处理能力。     

关于m.c环的K_0的一点注记

K群的计算是代数K—理论中的主要问题。本注记给出m.c环的K_0的一点计算:若M_R、M′_R′是有限生成的,R,R′是Classical环且分别为I_(m(τ)-adic),I_(m(μ) adic)拓扑完备的,则     

K_0R的p－子群

建立了范畴（Ｒ），讨论了－群与Ｋ_０Ｒ的ｐ－子群之间的关系，特别地，给出了二次域的代数整元环上Ｋ_０Ｒ的ｐ－子群结构。     

0—1型整数规划问题的求解方法

求解0—1型整数规划问题已经有许多较完善的方法,本文正是通过对这些方法的讨论和研究,提出一种新的求解方法,这种新方法对于求解较复杂的问题,非常有效。     

一种内对称引力规范相互作用的量子理论

在文[1]的基础上提出:引力可能存在一种内对称U(1)_2规范场。这种规范场是可量子化的,并给出了弗曼图与传播子。引力相互作用是通过这种规范场实现的。引力度规范场可能包含着不可量子化的内因。     

求二分图所有最小复盖的交的好算法以及由此求所有最小复盖的算法

本文给出了一个求二分图G所有最小复盖的交的好算法,其时间复杂性为O(max{|V(G))|~(1/2)。|E(G)|,|V(G)|~2})。并且在上述基础上再给出求所有最小复盖的算法,其时间复杂性为O(max{|V(G)|~(1/2)·|E(G)|,|V(G)|~2,|C|·|V(G)|})。其中V(G),E(G)分别是G的顶点集,边集,C是G的最小复盖组成的集     

Alzheimer’s disease: the impact of age-related changes in reproductive hormones

The relationship between menopause and cognitive decline has been the subject of intense research since a number of studies have shown that hormone replacement therapy could reduce the risk of developing Alzheimers disease in women. In contrast, research into andropause has only recently begun. Furthermore, evidence now suggests that steroidogenesis is not restricted to the gonads and adrenals, and that the brain is capable of producing its own steroid hormones, including testosterone and estrogen. Sex hormones have been demonstrated to be of critical importance in the embryonic development of the central nervous system (CNS); however, we are only just beginning to understand the role that these hormones may play in the normal functioning and repair of the adult mammalian CNS. This review will summarize current research into the role of androgens and andropause on cognition and the possible mechanisms of action of androgens, with particular reference to Alzheimers disease.