Stable cell membrane labelling

Binding fluorescent or radioactive reporter molecules to the lipid bilayer of cell membranes allows cell growth and trafficking to be monitored in vivo.     

Light-dependent antibody labelling of photoreceptors

Monoclonal antibodies are tools widely used to analyse the structure of the nervous system. Whereas some labelling patterns are highly reproducible, others appear to vary from one preparation to the next, as we noticed in particular for some antibodies with respect to photoreceptor labelling. To establish whether some of this variability can be linked to functional criteria, we tested for light-dependence. We found two antibodies that label photoreceptor outer segments, only when the retina has been illuminated, and a third antibody that has a selective affinity for dark-adapted outer segments. The two antibodies against light-activated sites are primarily directed against the highly phosphorylated neurofilament subunit at relative molecular mass 200,000 (200K). One of them, RT97, recognizes on immunoblots, in addition to neurofilaments, a light-activated epitope on a protein that resembles the photopigment rhodopsin, presumably a phosphorylation-dependent site. Antibodies like those described here may allow the study of physiological processes such as light and dark adaptation using morphological techniques.     

Radioactive cell membrane labelling.

Building upon earlier studies with fluorescent probes, the authors describe a new cell tracking compound, PKH95, with a radioactive signal, which has been developed specifically for high-sensitivity cell tracking and biodistribution studies.     

双圈图边幻和全标号

图的边幻和全标号是指图G(p,q)中任意一条边与其关联顶点的标号之和等于常数,且点和边的所有标号值一一映射到集合.该文针对双圈图,设计了一种边幻和标号判定算法,利用该算法可以得到15个点内的所有双圈图边幻和全标号.通过结果分析,找到了两类双圈图的标号规律,定义了新的图运算符号CnΔCl SymbolQCpSm和CnΔCl ΔSm来刻画这两类图,总结了若干定理并给出证明,进一步猜测当顶点数p≥16时,相关结论仍然成立.     

A note on vector labelling algorithm

An example is presented to show that it is unable to find any numerical Kakutani fixed point with vector labelling algorithms sometimes, and two sufficient conditions of finding numerical Kakutani fixed points are established.     

期刊条形码误用类型统计以及纠错对策

目的研究期刊条形码使用现状,指出期刊条形码使用乱象,提出纠正对策。方法以宝鸡文理学院图书馆馆藏期刊为主要统计研究对象,进行统计分析。结果统计了1143种期刊,其中未使用条形码的期刊有39种,在使用条形码的1104种期刊中,用年份码表示期刊出版年的期刊有146种,充其量仅有13．29／6,即约879／6的期刊条形码使用有误。一套条形码多年重复误用最为严重,有1999年的条形码至今仍然在重复误用!还有ISSN号与条形码不一致、误用前缀码、缺少校验码、附加码含义不清等误用类型,提出了尽快扭转期刊条形码使用混乱局面的几项对策,包括利用CorelDRAW9或者更高级的版本制作条形码等。结论普及期刊条形码结构常识,提高对于规范使用期刊条形码认识的自觉性,加强期刊条形码规范使用的检查力度,督促期刊编辑部尽快纠正期刊条形码使用过程中的种种乱象很有必要。     

Optimal isotope labelling for NMR protein structure determinations

Nuclear-magnetic-resonance spectroscopy can determine the three-dimensional structure of proteins in solution. However, its potential has been limited by the difficulty of interpreting NMR spectra in the presence of broadened and overlapping resonance lines and low signal-to-noise ratios. Here we present stereo-array isotope labelling (SAIL), a technique that can overcome many of these problems by applying a complete stereospecific and regiospecific pattern of stable isotopes that is optimal with regard to the quality and information content of the resulting NMR spectra. SAIL uses exclusively chemically and enzymatically synthesized amino acids for cell-free protein expression. We demonstrate for the 17-kDa protein calmodulin and the 41-kDa maltodextrin-binding protein that SAIL offers sharpened lines, spectral simplification without loss of information, and the ability to rapidly collect the structural restraints required to solve a high-quality solution structure for proteins twice as large as commonly solved by NMR. It thus makes a large class of proteins newly accessible to detailed solution structure determination.     

一类二部图的(d,1)-全标号

图G的一个k-(d,1)-全标号是一个映射f:V(G)∪E(G)→｛0,1,2…,k｝,使得(1) 相邻的顶点标不同的号;(2) 相邻的边标不同的号;(3) 顶点与所关联的边标号数相差至少为d (d≥2)。图G的(d,1)-全标号数定义为G有一个k-(d,1)-全标号的最小的k值。给出了一类二部图的(d,1)-全标号数。     

绿色化学与绿色化学教育

文章讨论了绿色化学的提出背景,系统地论述了绿色化学的研究内容,并提出了教改措施.     

绿色化学与绿色化学教育

文章讨论了绿色化学的提出背景,系统地论述了绿色化学的研究内容,并提出了教改措施。