Correlation of phenolic acid content of maize to resistance toSitophilus zeamais,the maize weevil,in CIMMYT'S collections

The (E)-ferulic acid content of the grain of nine populations of land races of maize derived from CIMMYT's collections was found to be negatively correlated to susceptibility characteristics towards the maize weevilSitophilus zeamais. Correlation coefficients for six susceptibility parameters and (E)-ferulic acid content were significant and ranged from –0.58 to –0.79. A multiple regression analysis by the SAS forward procedure using the primary seed characteristics associated with susceptibility indicated that the ferulic acid content was the only significant factor in explaining variation in at least two susceptibility parameters: the Dobie index and adult preference. In 15 CIMMYT pools, correlations between four susceptibility parameters and (E)-ferulic acid content were also significant (–0.76 to –0.81). The results suggest that phenolic acid content is a leading indicator of grain resistance or susceptibility to insects and may represent a newly identified mechanism of resistance.     

Passivation of pyrite due to surface treatment

Two samples of naturally occurring pyrite were treated with acetyl acetone, silanes, humic acids, lignin-NaOH mixture, and oxalic acid. The corrosion rate of pyrite was observed to decrease significantly due to the surface treatment by the chemicals used in this study. Surface characterization methods indicate that phenyl triacetoxy silane forms a passive coating a few Angstroms thick on the pyrite, thus preventing its dissolution in 1M H₂SO₄.     

多不饱和脂肪酸对人体神经系统保健作用研究进展

多不饱和脂肪酸,特别是ω-3系列的多不饱和脂肪酸对神经系统有着极其重要的作用,能够保护多巴胺能神经元、增强大脑活力、提高学习能力,尤其对胎儿及婴幼儿的大脑发育有很强的促进作用.多不饱和脂肪酸对视神经有保健作用,对神经系统肿瘤、精神性疾病也有较好的预防和治疗作用.     

薄层层析-紫外分光光度法测定银杏茶中银杏酸含量

采用薄层层析一紫外分光光度法建立了一种银杏茶中银杏酸快速检测的方法．采用正己烷索氏提取银杏茶中的银杏酸;以硅胶G为固定相,石油醚;乙酸乙酯：冰醋酸（18：1：1）为展开剂对银杏酸进行分离纯化;紫外分光光度法测定,波长为307nm．结果表明：该方法测定银杏酸含量的线性关系良好,线性范围为0．009-0．093mg／mL（R^2=0．9997）,精密度RSD为2．15％,平均回收率为100．90％,测定结果同HPLC法结果对照无明显差异,适用于银杏茶中银杏酸含量的测定．     

Polyamides incorporating furan moieties. 5. Synthesis and characterisation of furan-aromatic homologues

2,2′-Bis (5-chloroformyl 2-furyl) propane and various aromatic diamines were used as monomers in the study of their interfacial polycondensation and the properties of the ensuing furanic-aromatic polyamides. The effects of such variables as the nature of the organic phase, the temperature, the reaction time, and the type and concentration of the catalyst were investigated as well as the properties of the polyamides in terms of structure, average chain length, T_g, T_m and thermal stability.     

自乳化水性环氧防腐涂料乳液的探索研究

通过相转化法,用磷酸和丙烯酸及其酯类单体对环氧树脂进行改性,得到了一种性能优良的自乳化水性环氧防腐涂料乳液,主要用于容器内壁的防护装饰。     

DDI-microFIA--A readily configurable microarray-fluorescence immunoassay based on DNA-directed immobilization of proteins

We describe a chip-based immunoassay for multiplex antigen detection, based on the self-assembly of semi-synthetic DNA-protein conjugates to generate an easily configurable protein microarray. The general principle of this microarray-fluorescence immunoassay (microFIA) is similar to that of a two-sided (sandwich) immunoassay. However, covalent single-stranded DNA-streptavidin conjugates are employed for the efficient immobilization of biotinylated capture antibodies through hybridization to complementary surface-bound DNA oligomers. In a model system, we use the DNA-directed immobilization (DDI) of antibodies to generate an antibody microarray for the parallel detection of the tumor marker human carcinoembryonic antigen (CEA), recombinant mistletoe lectin rViscumin (rVis), ceruloplasmin (CEP), and complement-1-inactivator (C1A) in human blood serum samples. Detection limits down to 400 pg mL(-1) are reached. In addition, we describe a method for the internal standardization of protein microarray analyses, based on the simultaneous measurement of constant amounts of the blood proteins CEP and C1 A, intrinsically present in human serum, to compensate for interexperimental variations usually occurring in microarray analyses. The standardization leads to a significantly higher data reliability and reproducibility in intra- and interassay measurements. We further demonstrate that the DDI-microFIA can also be carried out in a single step by tagging of the analyte simultaneously with both capture and detection antibody and subsequent immobilization of the immunocomplex formed, on the DNA microarray capture matrix. This protocol significantly reduces handling time and costs of analysis.     

卡尔曼滤波同时pH滴定法研究

将卡尔曼滤波(KF)递推算法，用于多组分同时pH滴定中，讨论了方法原理，pH通道的选挥，同时对二、三、四元系统混合酸(碱)试祥，进行了多次测定，获得满意结果。     

复合氨基酸月桂醇酯的合成及性能

以菜籽粕水解制得的复合氨基酸浓缩液为原料,与月桂醇酯化制得复合氨基酸月桂醇酯.探讨了物料配比、反应时间、带水剂及催化剂对合成的影响,并对产品的表面活性进行了测定.结果表明:合成反应的最佳条件是月桂醇与复合氨基酸的摩尔比为1∶2.甲苯作带水剂(反应温度110～122℃),反应时间为4h,催化剂浓H2SO4的用量为复合氨基酸的8%,少量的聚乙二醇(PEG600)作相转移催化剂.制得的产品具有良好的泡沫稳定性.     

Tandem mass spectrometry in the study of fatty acids,bile acids,and steroids

Over the last 50 years, the mass spectrometry of lipids has evolved to become one of the most mature techniques in biomolecule analysis. Many volatile and non-polar lipids are directly amenable to analysis by gas-chromatography-mass spectrometry (GC-MS), a technique that combines the unsurpassed separation properties of gas-chromatography with the sensitivity and selectivity of electron ionization mass spectrometry. Less volatile and/or thermally labile lipids can be analyzed by GC-MS, following appropriate sample derivatization. However, many complex lipids are not readily analyzed by GC-MS, and it is these molecules that are the subject of the current review. Since the early 1970s, there have been three outstanding developments in mass spectrometry that are particularly appropriate in lipid analysis; i.e., the introduction of (i) fast atom bombardment (FAB); (ii) electrospray (ES); and (iii) tandem mass spectrometry (MS/MS). The FAB and ES ionization techniques will be discussed in relation to MS/MS, and examples of their application in biochemical studies will be presented. The review will concentrate on the analysis of fatty acids, bile acids, steroid conjugates, and neutral steroids.