A new inorganic–organic hybrid compound constructed from polyoxoanions and rare earth coordination complexes

A new chainlike polymer, Na[Ce(dipic)(H₂O)₃]₂ [CrMo₆H₆O₂₄] · 13H₂O (H₂dipic = pyridine-2,6-dicarboxylic acid) (1), has been synthesized and characterized by elemental analysis; IR and XPS spectroscopy, TG analysis, and single-crystal X-ray diffraction. Compound (1) is built up of Anderon-type polyoxoanions as structural motifs and cerium–dipic coordination fragments as linkers to yield an unprecedented one-dimensional chain. Such chains are further in close contact forming a three-dimensional supramolecular framework with channels via extensive hydrogen-bonding interactions among polyoxoanions, dipic ligands and water molecules. Furthermore, the magnetic properties of compound (1) have been studied by measuring their magnetic susceptibility in the temperature range 2–300 K.     

DNA／聚（3-甲基噻吩）复合膜修饰电极的制备及其应用于研究8-羟基-2＇-脱氧鸟嘌呤核苷的伏安行为及测定

首先通过电聚合方法在玻碳电极表面制备了聚（3-甲基噻吩）（P3MT）修饰膜,然后在一定电位下将DNA分子电沉积到P3MT表面,制备了DNA／（P3MT）复合膜修饰玻碳电极．研究了8-羟基-2’-脱氧鸟嘌呤核苷（8-OH-dG）在该复合膜修饰电极上的伏安行为以及扫描速度、pH值和尿酸对其伏安行为和检测的影响．实验结果表明,该复合膜修饰电极结合了P3MT和DNA两者的优点,使8-OH-dG在复合膜修饰电极上的电化学行为明显改善,而且具有很好的重现性和稳定性．在0．1mol／LpH7．0的磷酸盐缓冲溶液（PBS）中,8-OH-dG的氧化峰电流与其浓度在0．28～4．2μmol／L和4．2～19．6μmol／L两个范围内成良好的线性关系,检出限为56nmol／L（S／N=3）．该研究可以为制备HPLC或毛细管电泳电化学检测器检测8-OH—dG打下一定的基础,因此在检测尿样中8-OH-dG的研究方面具有潜在的应用价值．     

Synthesis, Structure and Luminescent Property of a Zinc(Ⅱ) Coordination Polymer Incorporating Flexible Cyclohexane-1,2,3,4,5,6-hexacarboxylate Ligand

The hydrothermal reaction of Zn(NO3)2·4H2O, cyclohexane-1,2,3,4,5,6-hexacarboxylic acid hydrate (H6LI·H2O, cis-conformation LI: a,e,a,e,a,e) and 2,2'-bpy yielded a new coordination polymer [Zn2(H2LII)(2,2'-bpy)]·2H2O(trans-conformation LII: e,e,e,e,e,e), which was characterized by single-crystal X-ray diffraction, elemental analysis, IR and XRPD(X-ray powder diffraction). This complex crystallized in the triclinic system, with P1 space group and parameters a=0.66922(5) nm, b=0.97291(8) nm, c=1.22184(9) nm, ...     

One-pot synthesis of stable NIR tetracene diimides via double cross-coupling

Tetracene tetracarboxylic diimides have been synthesized based on direct double ring extension of electron-deficient naphthalene diimides involving metallacyclopentadienes. Atomic structure and electronic transitions responsible for their NIR absorption spectra are investigated with quantum-chemical calculations. In light of their unique structure and admirable photophysical and electronic properties, this new molecular skeleton is promising candidate for n-type semiconductors.     

The use of ethylene glycol solution as the running buffer for highly efficient microchip-based electrophoresis in unmodified cyclic olefin copolymer microchips

An ethylene glycol solution was used as the electrophoretic running buffer in unmodified cyclic olefin copolymer (COC) microchips to minimize the interactions between the analytes and the hydrophobic walls of the plastic microchannels, enhance the resolution of the analytes and eliminate the uncontrollable dispersion caused by uneven liquid levels and non-uniform surfaces of the separation channels. Five amino acids that were labeled with fluorescein isothiocyanate (FITC) were used as model analytes to examine the separation efficiency. The effects of ethylene glycol concentration, pH and sodium tetraborate concentration were systematically investigated. The five FITC-labeled amino acids were effectively resolved using a COC microchip with an effective length of 2.5 cm under optimum conditions, which included using a running buffer of 20 mmol/L sodium tetraborate in ethylene glycol:water (80:20, v/v), pH 6.7. A theoretical plate number of 4.8 × 10(5)/m was obtained for aspartic acid. The system exhibited good repeatability, and the relative standard deviations (n=5) of the peak areas and migration times were no more than 3.4% and 0.7%, respectively. Furthermore, the system was successfully applied to elucidate these five amino acids in human saliva.     

Morphine-induced conditioned place preference in mice: Metabolomic profiling of brain tissue to find “molecular switch” of drug abuse by gas chromatography/mass spectrometry

Conditioned place preference (CPP) is a widely used model to explore the mechanism of context-dependent learning. In this work, we developed a GC–MS method to investigate the metabolites in mice brain which was used to study the mechanism of context-dependent learning associated with rewarding effect of morphine. Metabolites were extracted from brain tissues and derivatized followed by analysis by gas chromatography/mass spectrometry (GC–MS). In total, 69 peaks were identified as known compounds. By a Wilcoxon ran sum test with p value ≤0.05, 21 metabolites were selected and considered as the potential biomarkers of morphine in mice brain. Using principal component analysis (PCA) and receiver-operator characteristic (ROC) curves, a model was constructed with a combination of these 21 metabolic markers. Multivariate statistics of the model yielded separation between the two groups with an area under the curve value of 0.947. Some metabolites were further discussed in detail about their pathway. Results showed that our technique can be successfully applied to profile for biomarkers and in understanding molecular mechanisms of drug abuse.     

A Mini Review on the Functional Biomaterials Based on Poly(lactic acid) Stereocomplex

Poly(lactic acid) stereocomplex (sc-PLA) prevails over homo-poly(lactic acid)s in many aspects and showed great potential as biomaterials depending on its extraordinary biological, thermal, and mechanical properties. In the past few years, sc-PLA has gained tremendous attention as a new approach to the development of new types of functional biomaterials. This paper summarizes recent progress in the application of the concept of sc-PLA in the design and fabrication of stabilized nanoparticles and in situ gelling hydrogels for biomedical applications.     

SnO2TiO2 复合半导体纳米薄膜的研究进展*

本文概述了SnO₂TiO₂ 复合半导体纳米薄膜的发展历史和研究现状,对比分析了“混合”、“核壳”和“叠层”3 种复合薄膜的结构和性能特点,着重论述了叠层结构的SnO₂ /TiO₂复合薄膜的光电化学和光催化特性。结合作者的研究工作,探讨了SnO₂ /TiO₂双层复合薄膜上下层厚度对其光催化活性的影响,指出复合薄膜光催化活性的提高可归因于电子从TiO₂ 向SnO₂ 的迁移。最后对SnO₂ /TiO₂复合薄膜的局限性和发展潜势做一简要分析,强调了该复合薄膜本身的应用特点。     

Evolution of self-diffusion and local structure in some amines over a wide temperature range at high pressures: a molecular dynamics simulation study

Self-diffusion and structural properties of ammonia, methylamine and trimethylamine have been studied by molecular dynamics simulation in the temperature range between the melting pressure curve and 700 K at pressures up to 400 MPa. The calculation results agree well with the experiment, which suggests that one can use the simulation method as a powerful tool to obtain self-diffusion coefficients over wide range of temperatures and pressures, under which it is rather difficult for experiments. The local structures of such fluids are investigated by calculating radial distribution functions (RDFs), the numbers of hydrogen bonds and coordination numbers. The correlation between self-diffusion and structural properties, and the influence of temperature and pressure on them are discussed. The simulation results demonstrate that the temperature effects are more pronounced than the pressure effects on self-diffusion and structural properties, and the effect of hydrogen bonding on the translational dynamics in any of these systems is a minor factor, while it is mainly affected by the close packing of amine molecules.     

钨酸钠/冰乙酸/过氧化氢作用下聚丁二烯橡胶环氧化及降解行为研究

本文研究了在钨酸钠/冰乙酸/过氧化氢催化体系作用下聚丁二烯橡胶环氧化及降解行为.采用红外(FT-IR)、核磁(1H-NMR)和气相凝胶渗透色谱(GPC)对降解产物进行了表征,结果表明60℃反应24h,聚丁二烯橡胶环氧度为21.27％,而其分子量没有明显降低.