Effects of solute-matrix interaction on monitoring the conformational changes of immobilized proteins by surface plasmon resonance sensor

A real-time and labeling-free surface plasmon resonance (SPR) sensor was used to monitor the conformational changes of immobilized globule proteins (RNase A and lysozyme) in chemical unfolding and refolding. The effects of chemical denaturants on the protein structures were investigated. The methodology in protein conformational study on the solid surface is refined through the theoretic calculations and the conformational information of native/denatured proteins in solution. Additionally, our observation illustrates that the ambient buffer solution is merit to influence the refractive index of immobilized protein films and directly be observed from the SPR resonance angle shifts.     

Intramolecular Diels-Alder Reactions of Thio-Substituted Dienes with Enones

Thio-substituted dienes bearing an enone moiety were readily prepared from 3-sulfolenes, and their intramolecular Diels-Alder (IMDA) reactions were studied. Octahydronaphthalenones were produced in good yield with high stereoselectivity. Hexahydroindenones were also obtained, but the stereoselectivity was lower.     

二氧化硫的电化学氧化过程：Ⅲ.SO2在聚钴卟啉电极上的氧化机理

采用循环伏安法，稳态法，计时电位法等研究了ＳＯ２在聚钴卟啉膜电极上的电化学氧化过程，并和ＳＯ２在贵金属电极上的行为进行了比较。     

Studies on the thermotropic liquid crystalline polymer. XII. Synthesis and properties of crosslinkable thermotropic liquid crystalline homo- and copoly(ether-ester)s

A series of crosslinkable thermotropic liquid crystalline poly(ether-ester)s and copoly(ether-ester)s was prepared. All of the polymers were crosslinked by thermal treatment or photo-irradiation upon heating. The thermal stability and thermal crosslinking reaction of these polymers were investigated. These polymers also could be crosslinked by copolymerization with vinyl monomers, such as styrene or methyl methacrylate. The crosslinked polymers exhibited thermotropic liquid crystalline behavior after softening by heating. The phase behavior of linear polymers and crosslinked polymers was studied by differential scanning calorimetry (DSC) and an optical polarizing microscope equipped with a heating stage. © 1995 John Wiley & Sons, Inc.     

A validated HPLC method with ultraviolet detection for the determination of buformin in plasma

A sensitive and rapid high-performance liquid chromatographic assay is developed and validated for the determination of buformin in plasma. After addition of metformin as the internal standard, the analytes were deproteinated with acetonitrile, washed with dichloromethane, and the resulting supernatant injected. Chromatography was performed at ambient temperature by pumping a mobile phase of 0.03 m diammonium hydrogen phosphate buffer (pH 7, 250 mL) in methanol (750 mL) at a fl ow rate of 1 mL/min through a silica column. Buformin and metformin were detected at 236 nm, and eluted 9.8 and 15.4 min, respectively. No endogenous substances were found to interfere. Calibration curves were linear over the concentration range of 20-2000 ng/mL. The limit of quantitation was 20 ng/mL. The intra- and inter-day relative standard deviation (RSD) was 8.3%, or less, and the accuracy was within 10.1% of the relative error (RE). The method is suitable in pharmacokinetic investigation of buformin.     

微芯片电泳与电感耦合等离子体质谱的连接技术研究

研究了基于微芯片电泳分离和电感耦合等离子体质谱的连接技术,并对不同形态的Cu和As进行了快速分离和检测.     

Nitrato- and fluoroboracites M3B7O13NO3 and M3B7O13F

New boracites containing nitrato- or fluoroanions that appear to be true low-pressure phases have been synthesized at superatmospheric pressures. The M₃B₇O₁₃NO₃ compounds (M = Co, Ni, Cu, Zn, Cd) transform rapidly and reversibly in the temperature region 300–500°C between probable orthorhombic and face centered cubic symmetry, while the M₃B₇O₁₃F compounds (M = Mg, Mn, Fe, Co, Zn) appear to maintain rhombohedral symmetry up to their decomposition temperatures of 800–900°C. True high-pressure boracite-like phases containing F and Cr, Mn, Fe, or Co that decompose upon heating to M₃B₇O₁₃F have also been isolated.     

拟薄水铝石/陶瓷胶态加工浆料的流变性能

用拟薄水铝石纳米胶粒分散微米二硼化钛形成固含量为60Wt%的稳定陶瓷浆料,实验考察了拟薄水铝石固含量、二硼化钛固含量、温度对浆料流变性、稳定性的影响,对纳米γ-AlOOH胶粒分散微米TiB2的机制进行了讨论.大小约20nm的γ-AlOOH颗粒相互网联,成为外加微米陶瓷颗粒的骨架.浆料粘度随二硼化钛固含量的增加而增大,温度升高有利于胶体中薄水铝胶团与二硼化钛颗粒的相互作用并促进分散.     

Etudes cristallographique magnétique et par résonance Mössbauer de la variété de haute température du pyrophosphate NaFeP2O7

Single crystals of the high-temperature form of NaFeP₂O₇ have been grown by a flux technique. II-NaFeP₂O₇ crystallizes in the monoclinic $\text{P2}{}_1\text{c}$ space group with lattice parameters: a = 7.298(2) Å, b = 7.874(2) Å, c = 9.536(3) Å, β = 111.85(2)°. The structure refined from 1481 independent reflections leads to R = 0.044 and confirms the work previously published by M. Gabelica-Robert, M. Goreaud, P. Labbe, and B. Raveau (J. Solid State Chem.45, 389, 1982). Magnetic Mössbauer resonance studies have shown the existence of antiferromagnetic ordering with a weak ferromagnetic component below 30 K. The FeO bond is markedly ionic in character due to the highly polarizing power of phosphorus in tetrahedral site.