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81.
A novel and highly sensitive colorimetric sensor array was developed for the detection and identification of breath volatile organic compounds(VOCs) of patients with lung cancer.Employing dimeric metalloporphyrins,metallosalphen complexes,and chemically responsive dyes as the sensing elements,the developed sensor array of artificial nose shows a unique pattern of colorific changes upon its exposure to eight less-reactive VOCs and their mixture gas at a concentration of 735 nmol/L within 3 min.Potential of quantitative analysis of VOCs samples was proved.A good linear relationship of 490-3675 nmol/L was obtained for benzene vapor with a detection limit of 49 nmol/L(S/N=3).Data analysis was carried out by Hierarchical cluster analysis(HCA) and principal component analysis(PCA).Each category of breath VOCs clusters together in the PCA score plot.No errors in classification by HCA were observed in 45 trials.Additionaly,the colorimetric sensor array showed good reproducibility under the cyclic sensing experiments.These results demonstrate that the developed colorimetric artificial nose system is an excellent sensing platform for the identification and quantitative analysis of breath VOCs of patients with lung cancer. 相似文献
82.
Effects of polymer wrapping and covalent functionalization on the stability of MWCNT in aqueous dispersions 总被引:1,自引:0,他引:1
Ntim SA Sae-Khow O Witzmann FA Mitra S 《Journal of colloid and interface science》2011,355(2):383-388
The colloidal behavior of aqueous dispersions of functionalized multiwall carbon nanotubes (F-CNTS) formed via carboxylation and polymer wrapping with polyvinyl pyrrolidone (PVP) is presented. The presence of polymer on the nanotube surface provided steric stabilization, and the aggregation behavior of the colloidal system was quite different from its covalently functionalized analog. Based on hydrophobicity index, particle size distribution, zeta potential as well as the aggregation kinetics studied using time-resolved dynamic light scattering, the PVP wrapped CNT was somewhat less prone to agglomeration. However, its long-term stability was lower, and this was attributed to the partial unwrapping of the polyvinyl pyrrolidone layer on the CNT surface. 相似文献
83.
利用卟啉中位羧基基团直接缩合卟啉二聚体 总被引:2,自引:0,他引:2
卟啉单体的直接偶合法. 这种方法包括有β-β, meso-β直接连接的二聚体[8,9]和直接连接的N混杂的卟啉二聚体[10]. 我们利用二环己烷基羰化二亚胺(DCC)作催化剂, 在冰盐浴条件下, 通过两个5-(p-羧基苯基)-10,15,20-三苯基卟啉(H2CPTPP)周边上的羧酸基团一步直接缩合获得以羧酸酐连接的新型卟啉二聚体. 利用多种光谱手段证实所合成的物质为目标产物. 该方法具有反应物单一、 反应步骤简单、 副反应少、 产物纯化方便、 时间短和产率高等优点. 相似文献
84.
本文研究了一类超W-代数上某一权空间维数有限的不可约权模,证明了该权模必是Harish-Chandra模. 相似文献
85.
Partially purified transducin was resolved using two-dimensional gel electrophoresis (2-DE). Peptide mass fingerprinting of several different spots believed to correspond to the 37 kDa beta-subunit of transducin (T(beta)) was performed. Spots were excised and proteolyzed using modified trypsin. Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was performed on the peptide mixture resulting from each spot. As many as six spots with different pI, ranging from 5.2 to 6.1, were observed when separated using 2-DE. MALDI peptide mass fingerprinting determined with high probability that all of the spots were the same gene product, guanine nucleotide-binding protein G(I)/G(S)/G(T) beta-subunit 1 (GNB1; T(beta1)). This suggested that post-translational modification was responsible for the differences in pI. Phosphorylation experiments showed that at least one T(beta1) spot was phosphorylated in vitro with [gamma-(32)P]ATP by an endogenous kinase. Treatment of T(beta) with alkaline phosphatase caused a large change in the spot pattern of T(beta), suggesting that phosphorylated T(beta) is a substrate for alkaline phosphatase. We conclude that T(beta1) constitutes over 99% of the T(beta) expressed in bovine rod outer segments and displays structural heterogeneity that is due to post-translational modification. We also conclude that some, but not all, of the heterogeneity observed is due to phosphorylation of Tb1. 相似文献
86.
本文从反应产物, 化学反应计量关系, 电化学模拟和动力学测定诸方面对氧铵盐与dl-半胱氨酸在盐酸水溶液中的反应作了研究. 相似文献
87.
88.