Construction of dsDNA biosensor based on dendritic SiO2 nanoparticle and investigation on its interaction with benzo[a]pyrene

In this work, a new dsDNA biosensor was constructed to monitor the interaction of DNA and benzo[a]pyrene (BaP). Firstly, dendritic SiO₂ nanoparticles were synthesized by silanization of SiO₂ nanoparticles with (??-(methacryloyloxy)propyl) trimethoxysilane and polymerization with acrylic acid. Then, due to the rich carboxyl groups of these nanoparticles, they were associated with the amino groups of a self-assembly membrane formed on the gold electrode by a sulfur-containing compound, 5-amino-3-mercapto-1,2,4-triazole. Finally, dsDNA was immobilized on the electrode surface by static adsorption with the aid of metallic ion. The whole immobilization steps were characterized by cyclic voltammogram and electrochemical impedance spectrum. After that, using methylene blue as a probe, the interaction of BaP with dsDNA was investigated. A linear relationship between the percentages of current decrease with the logarithm of BaP concentrations was found in the range from 0.33 to 133???M.     

Density, viscosity, and surface tension of n-octanol-phosphoric acid solutions in a temperature range 293.15–333.15 K

Densities, viscosities, and surface tensions have been measured for n-octanol-phosphoric acid solutions in the range from x ₁ = 0 to 0.0266 and temperature from 293.15 to 333.15 K at atmospheric pressure. The coefficient of thermal expansion, excess molar volumes and deviations of surface tension are calculated from the experimental data. The excess molar volumes and deviations of surface tensions are fitted to use the Redlich-Kister polynomial equation. According to the experimental data, the measured viscosities are well fitted to regression equation under the correlating temperature and mass fraction of phosphoric acid. The experimental and calculated thermodynamic properties can be used in research on the nature of mixing behavior of the solutions for molecular models and industrial applications.     

Pharmacokinetic study of metoprolol in rabbit plasma by capillary electrophoresis with laser-induced Fluorescence detection

This work described a sensitive method for determination of metoprolol in rabbit plasma. The method involved purification by ultrafiltration, derivatization with Fluorescein isothiocyanate, separation by capillary electrophoresis and determination by laser-induced fluorescence detector. Other components in plasma including a variety of amino acids and proteins did not interfere with the determination of metoprolol under experimental conditions. The assay had a wide range (2.0?C500 ng/mL) of linearity and a detection limit of 0.8 ng/mL. The intra- and inter-day precisions of the QC samples were satisfactory with RSD less than 10% and accuracy within 10%. This method was successfully applied to pharmacokinetic study of metoprolol in rabbit blood.     

有机太阳能电池用聚合物给体材料的研究进展

有机太阳能电池由于质轻、价廉、柔性,受到人们的广泛关注.开发性能优异的聚合物给体材料,是近期有机太阳能电池研究的主流方向之一.迄今为止,已经成功开发出各种各样具有优秀的给体性质的共轭聚合物.基于这些材料制备的有机太阳能电池器件,已经突破9%的光电转换效率.按照聚合物给体材料的主链结构分类,综述了近年来这方面的研究进展.对一些受到普遍关注的材料,从设计思想、性能剖析到器件制备和性能,做了详细的介绍,以期能够深层次理解材料的化学结构-凝聚态结构-性能间的基本规律,为今后的材料研发提供有价值的参考.     

Detect early stage lung cancer by a LAMP microfluidic chip system with a real-time fluorescent filter processor

This work presents a promising clinical molecular diagnostics for early stage lung cancer. This novel diagnostic method utilized the loop-mediated isothermal amplification (LAMP), microfluidic chips and a confocal optical detector with a non-linear fluorescent filter processor. An isothermal amplification based microfluidic chip for the early diagnostics of lung cancer was developed and a confocal optical detector was improved by a novel real-time fluorescent filter to sensitively monitor the DNA amplification procedure with high signal to noise ratio and fluorescence collecting ability. Experiment showed that a rapid diagnostic of lung cancer by detecting the existence of the CEA mRNA could be performed in only 5 μL of reaction assay in less than 45 min. While the traditional in-tube RT-PCR set consumed more than 25 μL of the assay and took more than 90 min.     

Simultaneous determination of 20 food additives by high performance liquid chromatography with photo-diode array detector

An efficient and accurate analytical method was developed for the simultaneous determination of 20 synthetic food additives, including three sweeteners,seven food colorants,nine synthetic preservatives and caffeine,by high performance liquid chromatography (HPLC) with photodiode array detector(PDA).This method permits the detection of food additives at very low concentrations(0.005-0.150μg/mL).The applicability was verified by the determination of food additives present in various foodstuffs.     

Synthesis of pyridine-based poly(N-arylenebenzimidazole sulfone)

Poly（N-arylenebenzimidazole pyridine sulfone）（PNABIPS） has been prepared via the aromatic nucleophilic displacement reaction of 2,6-bis（2-benzimidazoly）pyridine（BBP） with bis（4-fluorophenyl） sulfone.BBP was synthesized by reaction of 2,6- pyridinedicarboxylic acid with 1,2-phenylenediamine in polyphosphoric acid.The chemical structure of BBP was confirmed by FTIR, HRMS,¹H NMR and ¹³C NMR.The characterization of the polymer was performed with FT-IR,¹H NMR,elemental analysis, GPC,XRD,DSC,TGA and solubility tests.The polymer was obtained in quantitative yield with M_n value 12,600 and M_w value 28,300,respectively.DSC and TGA measurements show that the glass transition temperature（T_g） is 312℃ and 5%weight loss temperature is 434℃ in nitrogen and 545℃ in air,respectively.In addition,the novel polymer exhibits good solubility,which can be dissolved in common organic solvent at room temperature.     

Effect of C∶N molar ratio on monomer composition of polyhdroxyalk anoates produced by Pseudomonas mendocina 0806 and Pseudomonas pseudoalkaligenus YS1

Polyhydroxyalkanoates (PHAs) are biodegradable polymers produced by bacteria. In this study, the effect of C∶N molar ratio on the monomer composition of PHAs was investigated, including medium chain length PHA produced by Pseudomonas mendocina 0806 and PHA blends consisting of monomers of 3-hydroxybutyrate and medium chain length hydroxyalkan⇘te produced by Pseudomonas pseudoalkaligenus YS1. It was observed that there were some fixed ranges of C∶N molar ratio that affect the monomer composition of PHA independently of the substrate. For strain 0806, the ranges were C∶N <20, 20<C∶N<200, and C∶N>200. The monomer composition was constant among these ranges when using glucose and octanoate as the sole substrate. For strain YS1, the ranges were C∶N<20, 20<C∶N<45, and C∶N>45. These results are useful for controlling monomer composition in PHA production.     

酸性铬蓝K固体石蜡碳糊修饰电极溶出伏安法测定痕量铅

在pH为8．5,0．2mol/L氨性缓冲底液中,以酸性铬蓝K（ACBK）为修饰剂,固体石蜡为粘合剂,制备了ACBK修饰碳糊电极。Pb2+以Pb-ACBK络合物的形式吸附在电极上,在-1．0V电位下电解,以阳极溶出伏安法测定Ph2+,在0．11V（vs.SCE）处有灵敏的氧化峰,其一次微分峰电流与Pb2+浓度在1．0×10-11～1．0×10-5mol/L范围内的对数呈良好的线性关系。此法的检测限为5．0×10-12mol/L。