Specific and genotypic identification of Cryptosporidium from a broad range of host species by nonisotopic SSCP analysis of nuclear ribosomal DNA

The accurate identification of Cryptosporidium (Protozoa: Apicomplexa) species and genotypes is central to the understanding of the transmission and to the diagnosis and control of cryptosporidiosis. In this study, we demonstrate the effectiveness of nonisotopic SSCP analysis of a approximately 300 bp region of the small subunit (pSSU) of ribosomal DNA for the specific identification of and delineation among 18 different Cryptosporidium species and genotypes from a wide range of hosts. This mutation scanning approach allowed the rapid and reliable differentiation between species/genotypes differing by as little as 1.3% in the pSSU sequence, with the capacity to detect point mutations. The present findings confirm the usefulness of this tool for the rapid genetic screening of Cryptosporidium samples from any host species, providing a foundation for detailed systematic, epidemiological and ecological studies. Although applied herein to pSSU, this low cost approach should be applicable to a wide range of genetic loci for population genetic investigations of Cryptosporidium.     

Haken 3-Manifolds in Small Covers*

The authors prove that a 3-dimensional small cover M is a Haken manifold if and only if M is aspherical or equivalently the underlying simple polytope is a flag polytope. In addition, they find that M being Haken is also equivalent to the existence of a Riemannian metric with non-positive sectional curvature on M.     

L\"obell多面体上的小覆盖

计算了L\"{o}bell多面体上的小覆盖的等变微分同胚类的个数. 在1991年, Davis和Januszkiewicz提出了小覆盖的概念, 给出了组合和拓扑间的一种直接联系, 并证明了单凸多面体上的特征映射($\mathbb{Z}_2^n$染色)与该多面体上的小覆盖一一对应. 文中作者给出了L\"{o}bell多面体上的自同构群和染色规律, 结合Burnside引理计算了一般的L\"{o}bell多面体上的小覆盖的等变微分同胚类的个数.     

甲基蓝与血红蛋白相互作用的共振瑞利散射光谱研究及小分子的影响

在弱酸性条件下,甲基蓝(MB)可以通过静电和疏水作用聚集到血红蛋白(Hb)上并形成离子缔合物,不仅使得吸收光谱发生变化,而且使得共振瑞利散射增强。据此发展了一种测定Hb的RRS便捷方法,其线性范围和检出限分别为0.2~20μg/mL和0.012μg/mL。与RRS法相比,分光光度法的线性范围和检出限分别为8~60μg/mL和0.688μg/mL(344 nm),5~60μg/mL和0.398μg/mL(408 nm)。此RRS法可用于尿样中Hb的痕量检测。实验考察了体系的吸收、散射光谱性质和最佳聚合条件,并在最佳条件下研究了分析参数及作用机理。并初步讨论了有机小分子对体系的影响,结果表明分子间氢键是主要作用力不容忽视。     

Highly viscoelastic reverse worm-like micelles formed in a lecithin/urea/oil system

While lecithin alone can form spherical or ellipsoidal reverse micelles in oil, we found that urea can promote the growth of lecithin reverse worm-like micelles in oil. In a mixed system of urea and lecithin, the urea binds to the phosphate group of lecithin, thus reducing the interface curvature of the molecular assembly and inducing the formation of reverse worm-like micelles. The regions in which these micelles form increased with lecithin concentration. In addition, the zero-shear viscosity (η ₀) of the reverse worm-like micelles rapidly increased upon the addition of urea, reaching a maximum of 2 million times the viscosity of n-decane. We examined the change in η ₀ in detail by performing dynamic viscoelasticity measurements. Values for η ₀ increased with urea concentration because the disentanglement time of reverse worm-like micelles increased with micellar growth.     

Analysis of Complex Molecular Systems: The Impact of Multivariate Analysis for Resolving the Interactions of Small Molecules with Biopolymers – a Review

This review is focused on the impact of chemometrics for resolving data sets collected from investigations of the interactions of small molecules with biopolymers. These samples have been analyzed with various instrumental techniques, such as fluorescence, ultraviolet–visible spectroscopy, and voltammetry. The impact of two powerful and demonstrably useful multivariate methods for resolution of complex data—multivariate curve resolution–alternating least squares (MCR–ALS) and parallel factor analysis (PARAFAC)—is highlighted through analysis of applications involving the interactions of small molecules with the biopolymers, serum albumin, and deoxyribonucleic acid. The outcomes illustrated that significant information extracted by the chemometric methods was unattainable by simple, univariate data analysis. In addition, although the techniques used to collect data were confined to ultraviolet–visible spectroscopy, fluorescence spectroscopy, circular dichroism, and voltammetry, data profiles produced by other techniques may also be processed. Topics considered including binding sites and modes, cooperative and competitive small molecule binding, kinetics, and thermodynamics of ligand binding, and the folding and unfolding of biopolymers. Applications of the MCR–ALS and PARAFAC methods reviewed were primarily published between 2008 and 2013.     

Linkage position influences of anthracene and tricyanovinyl groups on the opto-electrical and photovoltaic properties of anthracene-based organic small molecules

Anthracene-based small molecules incorporating an electron accepting tricyanovinyl (TCV) group was prepared to investigate the linkage position influences of the anthracene and TCV groups on the opto-electrical and photovoltaic properties of the molecules. The maximum absorptions of the anthracene-based molecules incorporating the TCV group at the phenyl group of the triphenylamine unit (TCV-TpaA_9,10T, TCV-TpaTA_9,10T, and TCV-TpaA_2,6T) or at the thiophene unit (TpaA_9,10T-TCV, TpaTA_9,10T-TCV, and TpaA_2,6T-TCV) were found to be dependent on the linkage position of the anthracene unit. The HOMO energy levels of the molecules containing TCV group at the phenyl group of the triphenylamine unit were deeper than those of the molecules containing TCV group at the thiophene unit. The solution processed small molecule organic solar cells (SMOSCs) prepared with the structure of ITO/PEDOT:PSS/TCV-TpaA_9,10T or TCV-TpaA_2,6T or TpaA_2,6T-TCV:PC₇₁BM (2:1 wt %)/LiF/Al exhibited a maximum energy conversion efficiency of 1.04%, 1.67%, and 1.95%, respectively, under AM 1.5 irradiation (100 mW cm⁻²).     

Analysis of small carbohydrates in several bioactive botanicals by gas chromatography with mass spectrometry and liquid chromatography with tandem mass spectrometry

Bioactive botanicals contain natural compounds with specific biological activity, such as antibacterial, antioxidant, immune stimulating, and taste improving. A full characterization of the chemical composition of these botanicals is frequently necessary. A study of small carbohydrates from the plant materials of 18 bioactive botanicals is further described. The study presents the identification of the carbohydrate using a gas chromatographic‐mass spectrometric analysis that allows detection of molecules as large as maltotetraose, after changing them into trimethylsilyl derivatives. A number of carbohydrates in the plant (fructose, glucose, mannose, sucrose, maltose, xylose, sorbitol, and myo‐, chiro‐, and scyllo‐inositols) were quantitated using a novel liquid chromatography with tandem mass spectrometric technique. Both techniques involved new method developments. The gas chromatography with mass spectrometric analysis involved derivatization and separation on a Rxi^®‐5Sil MS column with H₂ as a carrier gas. The liquid chromatographic separation was obtained using a hydrophilic interaction type column, YMC‐PAC Polyamine II. The tandem mass spectrometer used an electrospray ionization source in multiple reaction monitoring positive ion mode with the detection of the adducts of the carbohydrates with Cs⁺ ions. The validated quantitative procedure showed excellent precision and accuracy allowing the analysis in a wide range of concentrations of the analytes.     

新型双极有机小分子化合物及其Al3+配合物的合成与发光

合成了一种新的具有“双极”(bipolar)性质的有机小分子蓝色发光材料2-(5-(4-(二苯胺基)苯基)-1,3,4-噁二唑-2-)苯酚［2(5-(4-(diphenylamino)phenyl)-1,3,4-oxadiazol-2-yl)phenol, HPOT］, 并以HPOT为配体, 与铝离子配位, 合成了三(2-(5-(4-(二苯胺基)苯基) 1,3,4-噁二唑-2-)苯酚)合铝［tri(2-(5-(4-(diphenylamino)phenyl)-1,3,4-oxadiazol-2-yl)phenonate)aluminum, AlPOT］配合物. 用 1 H NMR、 HRMS和元素分析进行了表征, 并测定了两种化合物的光致发光性质和热稳定性. 结果表明: 两种新化合物的热稳定性好, 光致发光性能优良, 是制作有机电致发光器件的候选材料.