低温胁迫下油菜素内酯对高山离子芥悬浮细胞膜系统的影响

为研究低温胁迫下油菜素内酯(brassinosteroids, BRs)对植物细胞膜系统的影响,使用24-表油菜素内酯(24-epibrassinolide, EBR)在4℃处理高山离子芥(Chorispora bungeana)悬浮细胞.结果显示,低温胁迫下高山离子芥悬浮细胞的离子渗漏率和丙二醛(MDA)含量明显升高,而EBR处理显著降低了细胞的离子渗漏率和MDA含量.此外,低温胁迫下,EBR处理在一定程度上提高了膜脂脂肪酸不饱和程度并明显增强了细胞质膜H~+-ATPase,K~+-ATPase,Ca~(2+)-ATPase以及Mg~(2+)-ATPase的活性.另外,低温诱导CbCOR15基因大量表达.而在低温胁迫初期,EBR处理细胞的CbCOR15基因表达水平更高.以上实验结果表明,EBR在稳定低温胁迫下高山离子芥悬浮细胞膜系统的结构与功能方面发挥积极作用,从而保证细胞生理代谢的正常进行,以提高其抗寒能力.     

膜分离技术在制浆造纸工业中的应用

综述了膜分离技术在制浆造纸工业中的应用。膜分离技术可以用于制浆废液的浓缩,制浆废液中主要成分的分离,漂白废水、脱墨废水、涂布废水、纸机白水的处理。在制浆造纸工业中充分利用膜分离技术对解决污染问题,降低运行成本具有重要的意义。     

光合膜的研究进展

介绍了真核光合生物的光合膜的结构、组成、功能的最新研究进展。     

船舷侧板遭球鼻首撞击时的刚塑性分析及简化计算

本文从碰撞变形机理出发,采用薄膜理论,以数学表达式来描述舷侧板遭受球鼻首撞击时的变形模态,分别导出了舷侧板大变形下的撞击力P(λ),撞击能U(λ)和最大残余变形λ的理论公式;文中还从工程应用出发,导出了简化计算的解析式;经过实验验证,理论公式和简化计算公式,均与实验值吻合较好.     

膜反应器的开发进展

本文是有关膜反应器的一篇文献综述。文中详细讨论了膜反应器所用膜材料的种类、性能以及在各种化学反应中的应用。     

膜生物反应器的技术进展

本文主要叙述了UF膜、MF膜、RO膜及PV膜等的性质及其在生物反应器中的应用.其中平膜生物反应器、中空纤维膜生物反应器以及凝胶膜生物反应器在食品工业、医药工业、发酵工业、污水处理等部门获得了部分工业应用.     

可编程序控制器在真空镀膜机上的应用

中文介绍采用可编程序控制器改进单机单片磁控溅射真空镀膜机的设计和运行情况。本系统可以连续工作，每次可镀三十片玻璃，并可镀复合膜多达三层，比以前单机单片镀膜工艺显著提高了工作效率，降低了成本，改善了产品质量。     

纳滤膜的制备技术及进展

介绍了纳滤膜的几种主要制备方法，概述了近年来国内外在纳滤膜材质、制备技术及制膜的性能等方面的进展情况。     

Membrane protein folding on the example of outer membrane protein A of <Emphasis Type="Italic">Escherichia coli</Emphasis>

The biophysical principles and mechanisms by which membrane proteins insert and fold into a biomembrane have mostly been studied with bacteriorhodopsin and outer membrane protein A (OmpA). This review describes the assembly process of the monomeric outer membrane proteins of Gram-negative bacteria, for which OmpA has served as an example. OmpA is a two-domain outer membrane protein composed of a 171-residue eight-stranded -barrel transmembrane domain and a 154-residue periplasmic domain. OmpA is translocated in an unstructured form across the cytoplasmic membrane into the periplasm. In the periplasm, unfolded OmpA is kept in solution in complex with the molecular chaperone Skp. After binding of periplasmic lipopolysaccharide, OmpA insertion and folding occur spontaneously upon interaction of the complex with the phospholipid bilayer. Insertion and folding of the -barrel transmembrane domain into the lipid bilayer are highly synchronized, i.e. the formation of large amounts of -sheet secondary structure and -barrel tertiary structure take place in parallel with the same rate constants, while OmpA inserts into the hydrophobic core of the membrane. In vitro, OmpA can successfully fold into a range of model membranes of very different phospholipid compositions, i.e. into bilayers of lipids of different headgroup structures and hydrophobic chain lengths. Three membrane-bound folding intermediates of OmpA were discovered in folding studies with dioleoylphosphatidylcholine bilayers. Their formation was monitored by time-resolved distance determinations by fluorescence quenching, and they were structurally distinguished by the relative positions of the five tryptophan residues of OmpA in projection to the membrane normal. Recent studies indicate a chaperone-assisted, highly synchronized mechanism of secondary and tertiary structure formation upon membrane insertion of -barrel membrane proteins such as OmpA that involves at least three structurally distinct folding intermediates.     

冬季低温胁迫对长叶竹柏幼苗细胞膜的伤害

为探讨冬季低温胁迫对长叶竹柏幼苗细胞膜的影响，选取长叶竹柏的2龄幼苗为试验材料，进行不同海拔的低温胁迫对比试验．结果表明，在冬季低温胁迫下，细胞发生膜脂过氧化作用，细胞质膜的结构和功能受刭损伤，从而导致了叶片细胞膜透性增大，电解质外渗，电导率增大．同时，SOD，CAT和POD活性及膜脂过氧化产物MDA含量的测定表明，零上低温胁迫不会对植物造成严重的膜脂过氧化伤害，部分原因可能是SOD，CAT和POD活性的协调一致性．