关于"基质"概念的研究进展及应用

基质存在于细胞内和细胞外(细胞间).细胞内基质也叫细胞液,由细胞膜包被;细胞外基质是细胞间质的重要组成部分,也叫细胞外液.两者在形态学特征上均为无定形胶胨状,结构组成上有相似之处.     

腹腔镜胆囊切除术中并发症的防范

目的：探讨腹腔镜胆囊切除术中并发症的防范，以期减少和杜绝并发症的发生。方法：在术中对可能发生并发症的部位、组织器官正常与异常，做到解剖娴熟；能正确的使用腹腔镜的各种器械，特别是电凝钩剪等。结果：我院共施行腹腔镜胆囊切除术1咖例，发生胆总管横断伤1例，胃烙通伤1例，大出血2例，总发生率0．4％。结论：腹腔镜胆囊切除术具有创伤小、痛苦少、恢复快、腹部相对美容的优点；但要严密防范并发症的发生，因为一旦发生并发症，远比开胶胆囊切除的并发症处理困难得多。     

全球总动员寻找外星人

联合国计划耗资10多亿美元寻找外星人宇宙中到底有没有其他生命的存在,这一直是人类关心的大事。据美国媒体日前披露说,联合国正计划耗巨资研制超级设备来寻找外星人。寻找外星人的手段,一般是使用特殊的接收设备。因此,联合国有关部门目前正制定相关的计划,打算研制人类最大的射电     

关于单形稳定性几个不等式的推广

本文研究了F^n中n维单形的稳定性,在总结已有结论的基础上,对单形的稳定性进行了推广,同时也给出了单形几何不等式的新的稳定性版本,改进了已有的结论。     

A photovoltage-based integrated sensor for extracellular redox potential measurement and acidification detection

In this study,photovoltage technique is applied in the development of a monolithically integrated sensor for redox(reduction–oxidation)potential and pH measurement.The sensor employs the electrolyte–insulator–semiconductor structure,with deposition of a layer of gold metal on partial surface of insulator silicon dioxide.Silicon dioxide and gold layer on a single chip form two distinct sensing sites,by sharing the same measuring system,the detection of redox potential and pH variation can be realized.In this work,the sensor characteristics is tested,and the sensitivity for redox potential and pH measurement is53.8 mV/log([Fe(II)]/[Fe(III)])and 44.3 mV/pH respectively.To demonstrate the validity of the sensor in extracellular detection,neonatal rat kidney cells are cultured on the sensor surface and then packaged in a flow chamber,thus the acidification rate of metabolites and the redox potential variation in extracellular microenvironment can be continuously monitored.Experimental results indicate increasing acidification and reducing potentials under physiological conditions.The synthesis parameters have potentials in detail revelation of cell metabolism.     

Progress in crystallization of major histocompatibility complex class I in vertebrates

The major histocompatibility complex(MHC)of proteins that exists in all vertebrates is encoded by a cluster of genes associated with the immune response and related functions.MHC is divided into MHC I,II,and III;MHC I is involved in antigenic presentation,binding T cell receptors,and leading ultimately to specific cellular immune responses.The complicated functions of MHC I are determined by the nature of the complex.The crystal structure of MHC I has been solved for many animals,revealing the relationship between spatial structure and function.MHC I consists of an a heavy chain and a b2m light chain,both ligated non-covalently to a complex when a peptide is bound to the antigenic-binding groove.The a heavy chain is divided into an extracellular domain,a transmembrane domain,and an intracellular domain.The extracellular domain consists of sub-regions a1,a2,and a3.The a1 and a2 together form the antigenic-binding groove and bind antigenic peptides with 8–10 amino acid residues.MHC I can form a stable spatial structure;however,it should be noted that there are differences in the structure of MHC I among animal species,including anchored amino acids in binding peptides,binding sites,molecular distance,crystallization conditions,etc.Here,progress in determination of the crystal structure of human,mouse,chicken,non-human primate,and swine MHC I is described in detail.     

最大度为4的外平面图的无圈边色数

一个图G的无圈边染色是一个正常的边染色,使得任一个圈上至少有3种不同的颜色.G的无圈边色数a＇（G）是使得G有无圈k-边染色的最小整数k.设G是一个最大度为4的外平面图.对于现有结果 4≤a＇（G）≤5中,何时为4,何时为5,还没有一个完整的刻画.给出一个使得a＇（G）=4的充分条件,拓展了该领域的相关结果.     

钦州湾水质自动监测的周年变化特征

【目的】研究钦州湾(茅尾海和钦州湾外湾)周年水质变化特征,探讨海湾水质经常性超标的原因。【方法】利用2012年在线自动监测数据,分析海域水温、盐度、pH值、溶解氧以及叶绿素的周年日、季变化。【结果】两个海区盐度、pH值、溶解氧均呈现一、四季度高,二、三季度低的特征,其中最高值出现在第一季度,最低值出现在第三季度。茅尾海叶绿素最高值出现在第三季度,而钦州湾外湾出现在第一季度。茅尾海和钦州湾外湾水质超标主要为pH值,超标天数分别为243d和42d。【结论】茅尾海和钦州湾外湾受河流影响明显,pH值经常性超标,主要原因是采用海水标准评价,建议尽快确定河口区范围、制定河口水质评价方法和标准,以对主要河口区水质进行合理评价和管理。     

集胞藻胞外多糖的流变学性质和乳化活性

集胞藻在培养过程中向培养基中分泌大量胞外多糖,流变学研究表明这种胞外多糖呈现假塑性行为,粘度值接近黄原胶,当剪切速率在0.15 S-1时,两者粘度相等.集胞藻胞外多糖在0.1 mol/L氯化钠溶液中以及在30～70℃温度范围内粘度值具有一定的稳定性.集胞藻胞外多糖的粘弹谱类似于黄原胶.具有弱凝胶的特征.这种多糖具有良好稳定的乳化活性,对植物油、正十六烷、石蜡、二甲苯和2-甲基萘 正十六烷(1:1)都有乳化作用,而且在静置一个月后,乳液依然稳定.集胞藻胞外多糖可以作为增稠剂、稳定剂以及乳化剂在食品、化妆品工业等领域得到广泛应用.     

关于有根外-无弦平面地图计数

讨论了一般有根外-无弦平面地图依根点次和边数的计数问题.通过建立此类地图与有根不可分离平面地图之间的关系,利用已知不可分离平面地图的结果,得到外-无弦平面地图在以边数n为参数下的个数.