基于新型可视化学传感阵列的氨基酸快速识别

以卟啉和其衍生物及指示剂为传感元件,构建了一种对氨基酸敏感的可视传感阵列.可视化学传感阵列以交互响应的敏感元件组成阵列,对不同物质产生特异的响应,并通过信号识别处理系统,将检测结果以图谱的方式显示,实现检测的可视化.研究中筛选了对氨基酸敏感的36种化学物质,构建了6×6的传感阵列,使用自主研发的阵列数据采集与处理系统,对10种具有代表性的常见氨基酸进行了检测,氨基酸溶液与阵列的反应时间为5 min.对实验检测结果数据采用主成分分析和判别分析进行了计算和分析.实验结果显示,通过阵列响应的可视差图可以将浓度为375 μmol/L的10种氨基酸明显区分.判别分析结果显示,本可视阵列对氨基酸识别的准确率达到97%.二维主成分散点图和判别分析散点图对10种氨基酸都有显著分辨效果.本可视传感阵列可用于氨基酸的快速识别.     

羟基系列卟啉对三聚氰胺的检测研究

研究了四苯基卟啉(TPP)及5种羟基系列卟啉对三聚氰胺的检测,结果表明,TPP及羟基系列卟啉可以用来检测三聚氰胺,三聚氰胺与卟啉发生作用,导致其soret带特征峰强度的变化,其中邻二羟基卟啉对三聚氰胺的检测效果最好,检测限为0.2μg/L,摩尔吸光系数ε为0.6×106L·mol-1.cm-1。并对其作用机理进行了简要分析。     

用同步辐射X射线衍射技术分析GaN/Si外延膜的结构与应变

选用有AlN和AlGaN缓冲层的GaN/Si作为测试样品,采用同步辐射X射线衍射(SRXRD)技术对样品外延膜(GaN)的几何结构、晶格常量及其应变进行了分析.结果表明,同步辐射X射线衍射实验可以作为一种有效的技术手段,测试固体结构及应变.     

一种可视化液体传感阵列农药检测新方法

以筛选出的7种染料与合成的纳米金共同构建了液体传感器阵列,每个敏感点对不同农药样品产生不同的响应光谱,通过酶标仪采集光谱数据,结合主成分分析(PCA)、分层聚类分析(HCA)、判别分析(LDA)等模式识别方法建立了一种快速检测有机磷、氨基甲酸酯、有机氯、拟除虫菊酯类农药残留的新方法。PCA结果表明,前三个主成分反映了总信息量的92.69%,且能够对5种农药进行区分;HCA结果表明,对25个样品能够正确的归类;LDA结果表明,对5种农药识别的准确率达100%。表明这种可视化的液体阵列可为农药残留检测提供一个可靠平台,在农药残留检测中具有潜在的应用价值。     

Alterations in rabbit kidney protein expression following lead exposure as analyzed by two-dimensional gel electrophoresis.

It was recently reported that low blood lead levels impaired kidney function in men. To develop a set of molecular markers of renal lead exposure and effect, we investigated changes in renal protein expression while approximating occupational lead exposure at subchronic, low blood levels. Lead was administered to male Dutch Belted rabbits as a lead acetate solution adjusted weekly to achieve and maintain the target blood lead levels of 0, 20, 40, and 80 microg/dL for 15 weeks. Lead exposure did not affect kidney or body weights. The effect of increasing blood lead on protein expression was evaluated in rabbit kidney by large-scale two-dimensional electrophoresis (2-DE). Significant quantitative changes (p < 0.05) occurred in a dose-related manner in 12 proteins at 20 microg/dL exposure, 25 at 40 microg/dL, and 102 at 80 microg/dL. At a higher level of significance (p < 0.001), 40 microg/dL blood lead resulted in one protein alteration and 80 microg/dL affected 14 proteins. A set of quantitatively altered charge variants was tentatively identified as glutathione-S-transferase (GST), based on similar observations in rodents subjected to short-term, very high lead exposure. The significance of the protein alterations observed as markers of toxicity awaits their conclusive identification. Investigation of the kidney 2-DE profile in lead-exposed rabbit may be useful in understanding the mechanism of lead nephrotoxicity in humans.     

单质碘掺杂纳米TiO2光催化剂的制备及性能

以钛酸四异丙酯和单质碘为起始原料,用改进的溶胶-凝胶法制备了掺碘的纳米TiO2的前驱体,经500 ℃煅烧得到棕黄色TiO2/I2纳米粉末.采用X射线衍射(XRD),紫外-可见(UV-Vis)漫反射光谱,透射电镜(TEM)等手段对TiO2/I2粉末进行了表征,并研究了其光催化性能.结果表明,掺杂的碘存在于TiO2内部纳米孔洞中,不会因为高温而被氧化;光催化降解甲基橙反应是一级反应;TiO2掺杂碘单质后对光响应波长拓展至可见光范围,对甲基橙的降解效率可提高15%以上.     

Proteomic evaluation of cell preparation methods in primary hepatocyte cell culture

In vitro liver preparations are being used increasingly to study various aspects of chemical hepatotoxicity and thus have become powerful alternatives to in vivo toxicologic models. Primary hepatocyte culture systems are especially useful in screening cytotoxic and genotoxic compounds and assessing biochemical lesions associated with chemical exposure. We have begun to use this approach in combination with proteomic analysis to construct a molecular "toxicoproteomic" test system for a broad range of relevant and potentially toxic chemicals. Using a highly parallel two-dimensional electrophoretic (2-DE) protein separation system to analyze cells from culture systems, we previously observed significant variations in protein expression that were unrelated to chemical exposure. We hypothesized these artifactual protein alterations were the result of the variations in the culture conditions or cell manipulations, or both. Therefore, we conducted a study to assess the expression of hepatocyte proteins cultured on 6-well plates and recovered for analysis either by scraping/pelleting or direct in-well solubilization. Following incubation of 1.2 x 10(6) hepatocytes in six-well plate, recovery and solubilization of the cells and 2-DE of the solubilized lysates of 100 000 cells, we detected 1388 proteins in the in-well solubilized samples compared to 899 proteins in the washed/scraped/pelleted cell samples, a loss of 35%. Based on protein identification by peptide mass fingerprinting, the subcellular location of nearly all of the proteins whose abundance decreased were cytosolic and those few that increased were either microsomal, mitochondrial, or cytoskeletal proteins. These results emphasize the variation introduced by cell-handling during recovery of hepatocytes from culture plates and may explain at least some of the artifactual differences observed in earlier in vitro experiments.     

Application of pressure cycling technology to tissue sample preparation for 2-DE

2-DE is a powerful protein analytical tool whose major strengths include semiglobal quantitation and charge separation of complex protein mixtures, enabling the analysis of differential protein expression, and variable post-translational modification. One of 2-DE's limitations relates to its limited dynamic range and consequently the number of proteins expressed that can be analyzed on a single gel. In an attempt to improve the yield of detectable proteins during sample preparation, we applied a novel extraction technique called pressure cycling technology.