Novel chemiluminescent assay for staphylococcal enterotoxin B

An enzyme-linked immunosorbent assay, a horseradish peroxidase-catalyzed fluorogenic reaction, and chemiluminescence (CL) analysis have been combined to develop a sandwich ELISA for Staphylococcal enterotoxin B (SEB) using monoclonal antibodies for different epitopes of SEB. The enzyme catalyzed reaction of 3-(4-hydroxyphenyl propionate) with the urea complex of hydrogen peroxide produced a fluorescent dimer which was detected by chemiluminescence analysis. The CL response to SEB is linear in the range from 6.0 to 564?pg?mL^?1 (r?=?0.9993), and the detection limit is 3.3?pg?mL^?1 (S/N?=?3). Intra- and interassay coefficients of variation are <7.0% at three concentrations (24, 96 and 384?pg?mL^?1). The method was applied to the analysis of SEB in serum, lake water and milk samples. The results compared well with those obtained by conventional ELISAs.

Rhodium or palladium-catalyzed cascade aryl addition/intramolecular lactonization of phthalaldehydonitrile to access 3-aryl and 3-alkenyl phthalides

A rhodium or palladium-catalyzed addition of boronic acids to phthalaldehydonitrile, followed by an intramolecular lactonization of cyano to access 3-substituted phthalides, is described. This procedure tolerates a series of functional groups, such as methoxy, fluoro, chloro, and vinyl groups. It is a novel procedure for the synthesis of 3-arylphthalides.     

新型2-胺基-1,3,4-噻二唑类化合物的合成及其抗肿瘤活性的研究

设计合成了一系列新型的N1-(5-取代基-1,3,4-噻二唑-2-基)-N3-取代苯基-脲类化合物,并测定了它们的抗肿瘤活性.标题化合物对肿瘤转移的生物活性实验是以荷Lewis肺癌小鼠为模型的.生物活性表明部分标题化合物对肿瘤的转移和肿瘤生长具有较好的抑制作用.其结构经元素分析、红外光谱及1H NMR确证.     

N-(4-取代苯基-噻唑-2-基)香豆素类亚胺化合物的合成及抑菌活性研究

由含不同取代基的水杨醛与乙酰乙酸乙酯在哌啶存在下反应,得到乙酰基香豆素中间体,再与氨基硫脲缩合,得到含香豆素基的缩氨基硫脲化合物,继而与a-溴代芳基酮发生缩合反应,合成了9个未见报道的新的N-(4-取代苯基-噻唑-2-基)香豆素类亚胺化合物,其结构用IR,1HNMR和HRMS进行了确证,初步生物活性测定实验证明部分目标化合物具有良好的抑菌活性.     

含脱氢松香骨架的1,8-萘酰亚胺衍生物的合成及其对阴离子的识别

以歧化松香胺为原料合成了6个新型含脱氢松香骨架的1,8-萘酰亚胺衍生物2a～2b和3a～3d,其结构用1H NMR,13C NMR,MS和元素分析进行了表征.对3a～3d进行了阴离子识别研究,并对其识别机理进行了讨论.     

常压高频放电等离子体炬改进制备CO2/CH4重整用Ni/MgO催化剂

比较了常规法、等离子体炬法和等离子体炬辅助焙烧法制得的Ni/MgO催化剂上CO2/CH4重整反应性能差异,并利用X射线衍射、透射电镜、X射线光电子能谱和CO2程序升温表面反应等技术对反应前后催化剂进行了表征,结果表明,采用等离子体炬辅助焙烧法制备的催化剂上Ni晶粒粒径小,分散度较高,低温活性和抗积炭性能较高;在常压,7...     

A hevein-like protein and a class I chitinase with antifungal activity from leaves of the paper mulberry

Paper mulberry (Broussonetia papyrifera, syn. Morus papyrifera L.) is a Chinese traditional medicine and its low‐molecular‐weight extracts are reported to have antifungal activity. In this study, two proteins (PMAPI and PMAPII) with activity against Trichoderma viride were obtained from paper mulberry leaves with a fast protein liquid chromatography (FPLC) unit. The purification protocol employed (NH₄)₂SO₄ precipitation, ion‐exchange chromatography and hydrophobic‐interaction chromatography on FPLC. Molecular masses were 18,798 Da for PMAPI, and 31,178 Da for PMAPII determined by Matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry. Peptide mapping fingerprint analysis showed that PMAPI has no peptides similar to PMAPII. N‐terminal amino acid sequencing revealed that PMAPI is a hevein‐like protein, and PMAPII is a class I chitinase. They both had a half‐maximal inhibitory concentration (IC50) of 0.1 µg/µL against T. viride. This is the first report of high‐molecular‐weight extracts with antifungal activity from paper mulberry. Copyright © 2011 John Wiley & Sons, Ltd.     

Spatial bandgap engineering along single alloy nanowires

Bandgap engineering of semiconductor nanowires is important in designing nanoscale multifunctional optoelectronic devices. Here, we report a facile thermal evaporation method, and realize the spatial bandgap engineering in single CdS(1-x)Se(x) alloy nanowires. Along the length of these achieved nanowires, the composition can be continuously tuned from x = 0 (CdS) at one end to x = 1 (CdSe) at the other end, resulting in the corresponding bandgap (light emission wavelength) being modulated gradually from 2.44 eV (507 nm, green light) to 1.74 eV (710 nm, red light). In spite of the existing composition (crystal lattice) transition along the length, these multicolor nanowires still possess high-quality crystallization. These bandgap engineered nanowires will have promising applications in such as multicolor display and lighting, high-efficiency solar cells, ultrabroadly spectral detectors, and biotechnology.     

Communication: vacuum ultraviolet laser photodissociation studies of small molecules by the vacuum ultraviolet laser photoionization time-sliced velocity-mapped ion imaging method

We demonstrate that the vacuum ultraviolet (VUV) photodissociation dynamics of N(2) and CO(2) can be studied using VUV photoionization with time-sliced velocity-mapped ion imaging (VUV-PI-VMI) detection. The VUV laser light is produced by resonant sum frequency mixing in Kr. N(2) is used to show that when the photon energy of the VUV laser is above the ionization energy of an allowed transition of one of the product atoms it can be detected and characterized as the wavelength is varied. In this case a β parameter = 0.57 for the N((2)D°) was measured after exciting N(2)(o(1)Π(u), v(') = 2, J(') = 2) ← N(2)(X(1)Σ(g) (+), v(") = 0, J(") = 1). Studies with CO(2) show that when there is no allowed transition, an autoionization resonance can be used for the detection of a product atom. In this case it is shown for the first time that the O((1)D) atom is produced with CO((1)Σ(+)) at 92.21 nm. These results indicate that the VUV laser photodissociation combined with the VUV-PI-VMI detection is a viable method for studying the one-photon photodissociation from the ground state of simple molecules in the extreme ultraviolet and VUV spectral regions.