Oscillation condition for a series piezoelectric sensor. Application to the determination of urease activity in plant seeds

The oscillating conditions for a series piezoelectric quartz crystal (SPQC) are proposed and verified experimentally. The influence of the cell constant and oscillator phase on the oscillational ability of the SPQC was investigated. It is shown that the SPQC possesses excellent oscillational ability in low or high conductivity solutions, but in solution of intermediate conductivity, the oscillational ability decreases with increasing oscillator phase or decreasing cell constant, sometimes resulting in a cease-to-oscillate zone. The SPQC was applied to determine the urease activity in plant seeds with a detection limit of 0.004 U ml⁻¹, based on the change in conductivity.     

Determination of Organophosphorus Pesticides in Soil by MMSPD-GC-NPD and Confirmation by GC-MS

A novel method, modified matrix solid-phase dispersion (MMSPD), has been developed for quantitative analysis of organophosphorus pesticide residues in soil. It was based on matrix solid-phase dispersion (MSPD) and continuous liquid-solid extraction (continuous LSE), using Florisil as sorbent and dichloromethane as the recycling solvent. Two soils with different texture and physicochemical properties were studied to validate the method. The effect of residence time of pesticides in soil was also studied. MMSPD was compared with MSPD and continuous LSE respectively. Determination was carried out by gas chromatography with nitrogen-phosphorus detection (GC-NPD). The method gave recoveries ranging from 72–105% with relative standard deviations (RSDs) lower than 15% for the pesticides studied. The limits of detection (LODs) ranged from 0.1 to 0.6 ng g⁻¹. Two pesticide residues have been detected in real soil samples from Fujian, China, using MMSPD. The pesticides were confirmed by gas chromatography-mass spectrometry (GC-MS) in a selected-ion monitoring (SIM) mode. Revised: 4 and 9 April 2006     

MOLECULAR ENGINEERING STUDIES ON NONTHROMBOGENIC BIOMATERIALS——A NOVEL CLASS OF NONTHROMBOGENIC BIOMATERIALS WITH ZWITTERIONIC STRUCTURE OF CARBOXYBETAINES

N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium (DMMCA) was graft-copolymerized onto the surface of segmented poly(ether urethane) (SPEU) and PE film. The carboxybetaine structure on SPEU and PE film surfaces was confirmed by ATR-FTIR, XPS and water contact angle measurements. Through the experiments with platelet adhesion and protein adhesion assay in vitro, the two materials studied, including poly-DMMCA gel, all show excellent nonthrombogenicity. This confirms once again that the zwitterionic molecular structure on the surfaces of materials is essential for improving their nonthrombogenicity and biocompatibility.     

烷基吡啶盐和芳基季铵盐作检测和改性剂的羟基酸间接光度高效液相色谱研究

研究了苄基三甲基溴化铵动态改性、十四烷基吡啶盐等“永久性”涂渍的两种反相色谱,系统分离和间接光度检测了强极性、弱紫外吸收羟基酸。测定这些检测和改性试剂在YWG-CH反相填料和甲醇-磷酸缓冲液色谱体系的吸附等温线,探讨试剂在固定相的吸附量和其它因素对羟基酸保留、检测灵敏度的影响及分离检测机理。     

中性芳烃稀土有机配合物的合成、结构及性能研究——Ⅲ.RE(C_6H_6)(AlCl_4)_3C_6H_6(RE=La,Nd)的合成及Nd(C_6H_6)(AlCl_4)_3C_6H_6的晶体结构

将加热活化的AlCl_3与三氯化稀土在苯溶液中反应,合成了2个新的轻稀土中性芳烃配合物RE(C_6H_6)(AlCl_4)_3C_6H_6(RE=La或Nd)。并用元素分析和红外光谱对其进行了表征。测定了含Nd配合物的晶体结构。对2个配合物结构的比较表明,中心金属离子对配合物的结构无明显影响,其键参数的差别主要来自“镧系收缩”。     

Co-immobilization of polymeric luminol,iron(II) tris(5-aminophenanthroline) and glucose oxidase at an electrode surface,and its application as a glucose optrode

The anodic polymerization of 3-aminophthalhydrazide (luminol) and iron(II) tris 5-aminophenanthroline (Fe(phen-NH2)3(2+)) has been reported in this paper. A bilayer electrode was developed based on these polymers and the ITO conductive glass (denoted ITO[Fe(phen-NH2)3(2+)]luminol electrode). This electrode emitted light (lambdaem: 430 nm) as it was brought into contact with H2O2. At pH 10, the resulting electrochemiluminescence (ECL) showed a linear relationship with the concentration of H2O2 in the range of 10 microM(-1) mM. This bilayer electrode also showed an application potential for the detection of glucose after being further modified with glucose oxidase (denoted ITO[Fe(phen-NH2)3(2+)]luminol]GOx electrode). Although the resulting ECL decayed more rapidly in concentrated glucose solutions (e.g., I M) because of the consumption of luminol during use, the decay became less severe in diluted glucose solutions (e.g., 10 mM). According to the flow injection analysis, a linear relationship existed between the ECL and the concentration of glucose from 10(-5)-10(-3) M at pH 9. The detection limit could reach a level of 5 x 10(-5) M at this pH.     

Mesoporous silica nanospheres with the ability of photo-driven releasing sandela 803 for the application to wallpaper

Mesoporous silica nanospheres loaded with sandela 803 (S803@MS-S) are prepared for application to wallpaper. The nano-fragrance has high encapsulation efficiency and property of photo-driven release.     

Study of urinary nucleosides as biological marker in cancer patients analyzed by micellar electrokinetic capillary chromatography

Thirteen normal and modified nucleosides, primarily degradation products of transfer ribonucleic acid (tRNA), were evaluated as potential tumor markers for cancer patients. Their urinary concentrations were determined by means of micellar electrokinetic capillary chromatography (MEKC) in the urine from 54 healthy adults and 70 cancer patients, then quantitatively expressed as a function of creatinine excretion. It was found that urinary nucleosides for cancer patients were on the average significantly higher than those for healthy controls, however, no significant differences were found between male and female or between different ages. Based on 13 urinary nucleoside concentrations, principal component analysis (PCA) could be used to classify 72% of cancer patients from the healthy controls. The present study shows that the precise measurement of urinary nucleosides by MEKC in combining with PCA technique may provide a clinically useful approach for diagnosis of cancer.     

Preparation of mesoporous aluminophosphate using poly(amido amine) as template

Mesoporous aluminophosphate was prepared by using G4.0 poly(amido amine)dendrimer as a template and characterized by Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N₂ adsorption/desorption methods. Results show that the title compound exhibits a typical mesoporous structure with the average pore size from 5 to 8 nm. The formation mechanism of the nanoporous structure using dendrimer as a template was also discussed. __________ Translated from Journal of Fujian Normal University (Natural Science Edition), 2007, 23(2): 67–70 [译自: 福建师范大学学报 (自然科学版)]     

微波照射合成不对称1，4－二氢吡啶的研究

微波照射合成不对称１，４－二氢吡啶的研究张雅文，沈宗旋，潘备，杨海康，陆新华，陆澄容（苏州大学化学系苏州２１５００６）关键词缩合，二氢吡啶，微波Ｈａｎｔｚｓｃｈ合成是制备１，４－二氢吡啶的经典方法。这一合成的改进方法之一是３－氨基巴豆酸酯与醛和乙酰乙...