Different protein expression of myocardium from Chinese mini-swine model of myocardial infarct

High-resolution two-dimensional gel electrophoresis (2-DE), followed by computer-assisted image analysis was used to screen protein patterns of normal and infarcted myocardial tissues for quantitative and qualitative differences in protein expression. In the gels of pH 5–8 immobilized pH gradient (IPG) strips, 851 protein spots were detected in normal myocardial tissue and 1 032 protein spots were resolved in infarcted myocardial tissue. Thirteen protein spots only expressed in normal myocardial tissue, and 14 protein spots only expressed in infarcted myocardial tissue. Results also showed that 49 protein spots displayed quantitative changes in expression between normal and infarcted myocardial tissue. Eleven protein spots were subjected to mass spectrometry (MS) analysis and seven proteins were identified by peptide mass fingerprinting (PMF). These proteins may be involved in cardiovascular injury, and could play an important role in the treatment of coronary heart disease. __________ Translated from Chemical Journal of Chinese Universities, 2006, 8(27): 1467–1471 [译自: 高等学校化学学报]     

Graphene as Solid-Phase Extraction Adsorbent for CZE Determination of Sulfonamide Residues in Meat Samples

A solid-phase extraction (SPE) using graphene as adsorbent coupled with capillary zone electrophoresis method was developed for the determination of four sulfonamide residues (sulfadimidine, sulfadimethoxine, sulfathiazole and sulfadiazine) in meat sample. Several condition parameters, such as elution solvents and volumes, sample pH and sample volume were optimized to obtain high SPE recoveries and extraction efficiency. Intra-day precisions of sulfonamides were in the range of 2.5–2.6 % and the inter-day precisions of sulfonamides were in the range of 2.6–3.4 %. Recoveries were 60.9–66.6 % for sulfadiazine and 86.1–111.4 % for other three sulfonamides in spiked meat sample. The developed method was successfully applied for the determination of sulfonamides in meat samples.     

Determination of dopamine,epinephrine, and norepinephrine by open‐tubular capillary electrochromatography using graphene oxide molecularly imprinted polymers as the stationary phase

A novel capillary electrochromatography method was developed for the determination of dopamine (DA), epinephrine (EP), and norepinephrine (NE) by using a graphene oxide (GO) molecularly imprinted polymers (MIPs) coated capillary. In this article, GO was introduced as supporting matrix to synthesize MIPs in the presence of DA as template molecule. Then GO MIPs were used as the stationary phase in electrochromatography for the determination of DA, EP, and NE. The separation of these three analytes was achieved under the optimal conditions with a satisfactory correlation coefficients (R²) > 0.9957 in the range of 5.0–200.0 μg/mL for EP and NE, and 20.0–200.0 μg/mL for DA, respectively. The RSDs for the determination of three analytes were <6.19%, and the detection limits were 1.25 μg/mL for EP and NE, and 10.0 μg/mL for DA, respectively. Finally, this method was used for the determination of DA, EP, and NE in human serum and DA hydrochloride injection.     

A capillary coated with a metal-organic framework for the capillary electrochromatographic determination of cephalosporins

The authors have developed a rapid and reliable method for the capillary electrochromatographic determination of cephalosporin antibiotics in environmental waters. An open-tubular capillary column was modified with the complex [Cu(mal)(bpy)], a copper(II) complex with malic acid and 4,4′-bipyridyl, by an amide coupling method to act as the stationary phase. The simultaneous determination of the cephalosporins formulations, namely cefapirin (CP), ceftiofur (EFT) and cefixime (CFM) in environmental water samples was accomplished in buffer of pH 5.0 by applying a voltage of 8 kV and with DAD detection. Detection limits typically are 0.1 μg?mL^?1.The method was applied to the analysis of cephalosporins in spiked water samples from Kunming Lake to give recoveries betwen 88 and 106%.

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Graphical abstract A metal-organic framework (MOF) was synthesized from copper(II), malic acid and 4,4′-bipyridyl and used as stationary phase of capillary electrochromatography (CEC) by covalent immobilization on the capillary inner walls. Compared to an uncoated fused-silica capillary, improved separation of cephalosporin antibiotics can be accomplished.

     

Freestanding Carbon Nanotube Film for Flexible Straplike Lithium/Sulfur Batteries

Flexible lithium/sulfur (Li/S) batteries are promising to meet the emerging power demand for flexible electronic devices. The key challenge for a flexible Li/S battery is to design a cathode with excellent electrochemical performance and mechanical flexibility. In this work, a flexible strap-like Li/S battery based on a S@carbon nanotube/Pt@carbon nanotube hybrid film cathode was designed. It delivers a specific capacity of 1145 mAh g⁻¹ at the first cycle and retains a specific capacity of 822 mAh g⁻¹ after 100 cycles. Moreover, the flexible Li/S battery retains stabile specific capacity and Coulombic efficiency even under severe bending conditions. As a demonstration of practical applications, an LED array is shown stably powered by the flexible Li/S battery under flattened and bent states. We also use the strap-like flexible Li/S battery as a real strap for a watch, which at the same time provides a reliable power supply to the watch.     

MAE–GC Determination of Methamphetamine, 3,4-Methylenedioxyamphetamine and 3,4-Methylenedioxymethamphetamine in Human Urine

Methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) were extracted from human urine by using microwave-assisted extraction (MAE) followed by gas chromatography analysis with flame ionization detection. In order to improve the extraction efficiency, experimental parameters on the extraction, including extraction solvent and its volume, pH value of sample, extraction time and temperature were investigated. Under the optimal conditions, the average recoveries of MA, MDA and MDMA were 92.25, 85.94 and 91.50%, respectively. And the intra-day and inter-day relative standard deviations were not greater than 6.9%. The results indicate that the developed method is rapid, accurate and sensitive, and can be used for the simultaneous determination of MA, MDA and MDMA in urine for forensic application.     

微波萃取-气相色谱法测定血液中的可卡因及其代谢物爱冈宁甲基酯

建立了血液中可卡因(cocaine, COC)及其代谢物爱冈宁甲基酯(ecgonine methyl ester, EME)的气相色谱-质谱(CG-MS)和气相色谱-氢火焰离子化检测(GC-FID)方法。该方法采用微波萃取提取血液中的COC和EME,优化并确定了最佳提取条件: 以氯仿-异丙醇(体积比为9:1)混合溶液为提取溶剂,用0.05 mol/L Na2CO3-NaHCO3缓冲溶液调节样品溶液的pH至10.0,在40 ℃下微波萃取6 min;采用GC-MS对萃取液中的COC和EME进行定性,采用GC-FID进行定量检测。COC和EME的平均回收率分别为79.91%～99.85%,相对标准偏差(RSD)均小于3.10%,检出限(S/N=3)分别为60 mg/L和40 mg/L。该方法无需衍生化,快速、准确、灵敏,可同时检测血液中的COC和EME。     

关于随机紧凸集的更新定理

该文在讨论了多维更新定理的基础上,重点研究了随机紧凸集的Minkowski和的更新定理,得到了一系列重要结论.     

固相萃取-胶束电动色谱法测定牛奶中的4种β-内酰胺类抗生素

建立了同时分离检测牛奶中的氨苄西林、阿莫西林、青霉素V和头孢氨苄4种β-内酰胺类抗生素的固相萃取-胶束电动色谱法。牛奶样品经沉淀蛋白后,采用HLB固相萃取柱净化浓缩;以含十二烷基硫酸钠(SDS)的磷酸盐为缓冲液,胶束电动色谱分离,210 nm波长下检测。分离电压为18 kV,于9 min内达到基线分离。各组分在0.5～20 mg/L范围内呈良好的线性关系,相关系数(r2)为0.9943～0.9976;检出限为0.16～0.20 mg/L;除了阿莫西林外,回收率均大于70%。该方法准确可靠,重复性好,灵敏度高,可以用于牛奶中β-内酰胺类抗生素的定量检测。