A study on the interaction between ibuprofen and bilayer lipid membrane

Ibuprofen is a well-known nonsteroidal anti-inflammatory drug, which can interact with lipid membranes. In this paper, the interaction of ibuprofen with bilayer lipid membrane was studied by UV-vis spectroscopy, cyclic voltammetry and AC impedance spectroscopy. UV-vis spectroscopy data indicated directly that ibuprofen could interact with lipid vesicles. In electrochemical experiments, ibuprofen displayed a biphasic behavior on bilayer lipid membrane supported on a glassy carbon electrode. It could stabilize the lipid membrane in low concentration, while it induced defects formation, even removed off bilayer lipid membrane from the surface of the electrode with increasing concentration. The mechanism about the interaction between ibuprofen and supported bilayer lipid membrane was discussed.     

高频MnZn功率铁氧体烧结工艺研究

按照氧化物陶瓷工艺对高频MnZn功率铁氧体烧结工艺条件进行了研究。烧结温度越高，晶粒越大，晶界越薄，电阻率越低，磁芯损耗越大，起始磁导率和烧结密度分别在1240℃和1230℃达到最大值。延长保温时间，可以使晶粒充分生长，晶界变薄，电阻率减小，损耗增大。保温3h后，起始磁导率和烧结密度均可达到最大值。氧分压越低，材料起始磁导率越高，电阻率越小，损耗越大，但氧分压低于5％后烧结密度不再继续增加。     

Concast连铸机自控系统简介

天津钢铁有限公司引进了瑞士Concast公司6机6流方、圆坯连铸机及相关技术，文章简要介绍了Concast连铸机的自动控制系统的特点和功能。     

科研项目管理信息系统的设计

介绍了用自顶向下的结构化方法进行科研项目管理信息系统设计的过程。该系统的应用节省了大量人力、物力和财力,提高了企业科研项目管理水平。     

Miniaturized Hexagonal Stepped-Impedance Resonators and Their Applications to Filters

Miniaturized hexagonal stepped-impedance resonators and their applications to bandpass filters are presented. Based on the odd- and even-mode equivalent circuits, the resonance characteristics of these resonators are investigated. A series of circuit configurations, including the third-order Chebyshev, trisection, and fifth-order cascaded trisection filters, are constructed by the proposed resonators. These filters are very compact and have good stopband responses. Measured results validate the analysis and theoretical prediction with good agreement.     

基础锚栓预埋加固方案

结合工程实例 ,介绍轻钢结构系统基础锚栓预埋、加固解决方案 ,并介绍了加固系统的制作及使用方法 ,可供工程人员参考     

Application of ultrasonic waves in activation of microcrystalline cellulose

In this work, microcrystalline cellulose (MCC) was activated with ultrasonic waves. The influences of ultrasonic treatment on the changes of supramolecular structures and morphology structure were studied by WAXS and SEM. The accessibility of the MCC was characterized by water retention value (WRV) and specific surficial area. The influence of ultrasonic treatment on the reactivity of MCC was investigated through the reaction of MCC being oxidized into 2,3‐diadehyde cellulose (DAC) by periodate sodium. The mechanism of the reactivity change of ultrasonically treated MCC was examined. The results showed that the degree of crystallinity of MCC decreased and the degree of polymerization showed little change after treatment with ultrasonic waves. The morphologial variation of the treated MCC was significant when compared with the untreated MCC, which contribute to the improvement of accessibility. The aldehyde content of DAC prepared from ultrasonically treated MCC was improved from 64.19 to 85.00%, indicating that the regioselective oxidation reactivity of MCC was significantly improved. The aldehyde content was found to first increase with time of ultrasonic treatment to a point, and then decrease as time progressed. In addition, the aldehyde content was found to increase with an increase in ultrasonic power. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

A disposable sensor based on immobilization of acetylcholinesterase to multiwall carbon nanotube modified screen-printed electrode for determination of carbaryl

A simple method has been devised for immobilization of acetylcholinesterase (AChE) covalent bonding to a multiwall carbon nanotube (MWNT)-cross-linked cellulose acetate composite on a screen-printed carbon electrode (SPCE) and a sensitive and disposable amperometric sensor for rapid determination of carbaryl pesticide is proposed. The immobilized enzyme was preserved on this film because of the excellent biocompatibility and non-toxicity of cellulose acetate. Based on the inherent conductive properties of the MWNT, the immobilized AChE had greater affinity for ATCl and excellent catalytic effect in the hydrolysis of ATCl. MWNT improved the interface enzymatic hydrolysis reaction and increased the amperometric response of the sensor. Under optimum conditions, the inhibition of carbaryl on AChE increased linearly with the increasing concentration of carbaryl in two ranges, from 0.01 to 0.5 μg mL⁻¹ and from 2 to 20 μg mL⁻¹, with the correlation coefficients of 0.9985 and 0.9977, respectively. The detection limit was 0.004 μg mL⁻¹ taken as the concentration equivalent to 10% decrease in signal. The sensor showed acceptable stability, accuracy and could be fabricated in batches, thus it is economic and portable. This type of disposable enzyme-based amperometric sensor has extensive application potential in environmental monitoring of pesticides.