弹性聚四氟乙烯/聚氨酯共混薄膜的制备与性能研究

在分散型聚四氟乙烯树脂（PTFE）中混入热塑性弹性体聚氨酯（TPU）,采用二次双向拉伸制备了具有良好弹性的多微孔薄膜,并对薄膜进行弹性性能测试及透射电镜（TEM）和 表面扫描电镜（SEM）观察。结果表明：TPU在PTFE中能够均匀掺混,经二次双向拉伸后PTFE 形成了网状结构,TPU依附在PTFE纤维上也被拉伸成细小纤维,二者共同形成了多微孔薄膜,而且TPU的加入有效地改善了PTFE薄膜的弹性性能。     

凝固条件对聚醚砜膜结构和性能的影响

讨论了在聚醚矾／聚乙二醇／二甲基乙酰胺制膜体系中凝固簪件的变化对膜的结构及性能的影响。水通量随着顸蒸发时间的延长、凝固浴温度的上升而上升；孔隙率随着凝固浴温度的上升而上升，而与预蒸发时间的长短没有关系；对牛血清白蛋白的截留率随着凝固浴温度的上升而下降，随着预蒸发时间的延长先略有下降然后上升。当预蒸发时间较短和凝固浴温度较高时，膜的支撑层为典型的小而均匀的海绵状网络孔结构，基本看不出过渡层；而当预蒸发时间较长和凝固浴温度较低时，可以分出致密层、过渡层和多孔支撑层，且支撑层有更大更深的类似于针状孔或指状孔的孔结构。     

胎膜早破对新生儿脐血免疫球蛋白及补体的影响

目的:研究胎膜早破时新生儿脐血免疫球蛋白、补体的变化规律。方法:应用速率透射比浊法检测79例新生儿脐血IgG、IgA、IgM和补体C3、C4水平,追踪新生儿出生1周内感染发生的情况,其中有胎膜早破史的研究组38例,无胎膜早破史的对照组41例。结果:胎膜早破组脐血IgA(0.16±0.12)g/L,对照组(0.06±0.03)g/L,(P<0.01);胎膜早破组IgM(0.24±0.15)g/L,对照组(0.16±0.03)g/L,(P<0.01),差异有统计学意义;脐血IgG水平无明显变化;脐血IgA浓度在胎膜早破72h为0.234±0.156)g/L,较胎膜早破<12h的0.091±0.047g/L明显增加,差异有统计学意义(P<0.05);脐血补体C3(0.76±0.35)g/L,对照组(0.93±0.21)g/L,(P<0.05),C4(0.16±0.09)g/L,对照组0.20±0.05g/L,(P<0.05),研究组明显低于对照组,差异有统计学意义。结论:有胎膜早破史的新生儿,脐血免疫球蛋白IgA、IgM浓度升高,IgG不受胎膜早破的影响,脐血补体C3、C4水平下降。脐血IgA、IgM及补体C3、C4均能反映胎膜早破个体合并宫内感染。     

提取分离活性染料的微乳液膜体系研究

对适用于提取分离水溶液中活性染料的微乳液膜体系进行研究．以三元相图为实验方法，考察了表面活性剂、助表面活性剂、油溶剂以及促进迁移载体的选择和用量；分析了不同内水相浓度、温度等因素对微乳液膜的影响．实验结果表明，以OP-7为表面活性剂、异戊醇为助表面活性剂、煤油为油溶剂、N235为促进迁移载体组成有机相，以NaOH溶液为内水相的微乳液膜体系，可有效提取分离活性染料艳蓝-K．     

Functional significance of the lipid-protein interface in photosynthetic membranes

The functional significance of the lipid-protein interface in photosynthetic membranes, mainly in thylakoids, is reviewed with emphasis on membrane structure and dynamics. The lipid-protein interface is identified primarily by the restricted molecular dynamics of its lipids as compared with the dynamics in the bulk lipid phase of the membrane. In a broad sense, lipid-protein interfaces comprise solvation shell lipids that are weakly associated with the hydrophobic surface of transmembrane proteins but also include lipids that are strongly and specifically bound to membrane proteins or protein assemblies. The relation between protein-associated lipids and the overall fluidity of the thylakoid membrane is discussed. Spin label electron paramagnetic resonance spectroscopy has been identified as the technique of choice to characterize the protein solvation shell in its highly dynamic nature; biochemical and direct structural methods have revealed an increasing number of protein-bound lipids. The structural and functional roles of these protein-bound lipids are mustered, but in most cases they remain to be determined. As suggested by recent data, the interaction of the non-bilayer-forming lipid, monogalactosyldyacilglycerol (MGDG), with the main light-harvesting chlorophyll a/b-binding protein complexes of photosystem-II (LHCII), the most abundant lipid and membrane protein components on earth, play multiple structural and functional roles in developing and mature thylakoid membranes. A brief outlook to future directions concludes this review.     

Lipid transfer in plants

Summary Plant cells contain cytosolic proteins, called lipid transfer proteins (LTP), which are able to facilitate in vitro intermembrane transfer of phospholipids. Proteins of this kind from three plants, purified to homogeneity, have several properties in common: molecular mass around 9 kDa, high isoelectric point, lack of specificity for phospholipids, and binding ability for fatty acids. The comparison of their amino acid sequences revealed striking homologies and conserved domains which are probably involved in their function as LTPs. These proteins could play a major role in membrane biogenesis by conveying phospholipids from their site of biosynthesis to membranes unable to form these lipids. Immunochemical methods were used to establish an in vivo correlation between membrane biogenesis and the level of LTP or the amount of LTP synthesized in vitro from mRNAs. The recent isolation of a full-length cDNA allows novel approaches to studying the participation of LTPs in the biogenesis of plant cell membranes.     

聚2-乙烯基吡啶/聚苯乙烯互穿聚合物网络双电荷膜的合成

通过分步光聚合法制备聚2-乙烯基吡啶/聚苯乙烯(P(2-VP)/PS)IPN膜,采用苯环磺化和吡啶环季胺化分别引入正负双电荷,经过电镜、动态力学性能及交换容量的测试表明,所合成的双电荷IPN膜是双相连续并对Na~+及Cl~-有一定交换容量。     

微波（2450MHz）对整体小白鼠红细胞膜的损伤效应及药物防护

本文采用２４５０ＭＨｚ微波慢性辐射整体昆明小白鼠，从分子水平研究微波对小白鼠红细胞膜的影响。选择功率密度０ｍＷ／ｃｍ２、５ｍＷ／ｃｍ２（ＳＡＲ＝５．５ｍＷ／ｇ）、１０ｍＷ／ｃｍ２（ＳＡＲ＝１１ｍＷ／ｇ）的微波连续辐射小白鼠４０天，每天６小时。发现１０ｍＷ／ｃｍ２的微波对小白鼠红细胞膜的损伤较为明显。表现为小白鼠红细胞的渗透脆性增加，膜脂流动性下降，血浆丙二醛（ＭＤＡ）及红细胞膜ＭＤＡ均为明显升高，但红细胞溶血度未增加，红细胞ＳＯＤ、红细胞膜ＡｃｈＥ活动和膜蛋白组份的百分含量也未见明显变化。此外，本文还从自由基角度初步探讨了微波辐射损伤的机理。实验表明，喂服维生素Ｃ的小白鼠有抗微波损伤的作用，这启示一定剂量的维生素Ｃ对微波损伤有防护作用。     

乳化液膜的拟稳态扩散-反应模型

导出了文题的模型。该模型假设乳液滴无再分散、无内循环、且直径均一;内相微滴在乳液滴中均匀分布,考虑了扩散组分在乳液滴内、外的传质及其与内相试剂在滴内的反应,得到了含有参数E、B_i及D_a的分析解(E为试剂比的3倍:B_i为扩散组分在滴内、外的传质阻力之比;D_a为滴内反应速率与扩散速率之比)。当D_a→∞时,此解与外相边界层及膜相扩散控制模型的解相同。当D_a→∞且同时B_i→∞时,它又还原为渐进前沿模型的解。计算结果表明:萃取速率分别随E、B_i及D_a的增加而增加;在一定条件下,当D_a<2或D_a>200时,过程分别受反应与扩散控制,而当D_a介于两者之间时,过程同时受反应与扩散的影响;D_a对过程的影响随E或B_i的增加而增加。模型计算值与实验值能很好地吻合。