荧光素酶与金丝桃素-镁离子配合物的相互作用

采用紫外-可见光谱法、荧光光谱法、圆二色谱法等研究了荧光素酶(Luc)与金丝桃素-镁离子配合物(Hyp-Mg~(2+))的相互作用,包括结合位点、结合常数、结合力强弱、生物大分子构象变化等因素的影响.紫外-可见光谱表明,Hyp-Mg~(2+)与荧光素酶发生反应且改变了荧光素酶的分子结构.荧光数据表明Hyp-Mg~(2+)与荧光素酶通过生成非荧光复合物的静态猝灭而有效地猝灭了荧光素酶的荧光.对荧光光谱数据处理得到298 K下Hyp-Mg~(2+)与荧光素酶的结合常数为3.13×10~5L/mol.CD光谱表明,Hyp-Mg~(2+)可改变荧光素酶的分子构象.     

CD-1型气介式超声波测距仪

上海超声波仪器厂最近研制成功的CD-1超声波测距仪,体积小,集成度高,可靠性好.耗电量小,功能全,使用简便.它以空气为媒介,非接触地遥测距离.它可广泛应用于自动控制系统中.如距离跟踪仪,位移控制器,行车防撞器,汽车倒车指示器,多种防盗设备,各种遥控开关和遥测装置等. 本仪器不仅能自动遥测数字显示距离,还可根据用户要求在0.5—9.9m的范围内输出随距离而连续变化的电压、BCD码、CP脉冲和定点(定距离)的开关信号,以满足各种自动控制设备的特殊需要. 本仪器的特点:体积小 39×20×130(mm~3);功耗低 整机耗电0.03W;无极性供电 首创无极性供     

适配体功能化DNA纳米生物传感器应用研究进展EI北大核心CSCD

适配体功能化DNA纳米结构是构建新型生物传感器的理想材料,为临床诊断、食品安全、环境监测等领域提供了材料基础。本文介绍了核酸适配体在功能化DNA纳米结构中的作用,论述了适配体功能化DNA纳米结构的构建方法,以及其在基于固定化和构象开关的电化学生物传感器的最新应用研究。本文为适配体功能化DNA生物传感器的构建提供了制备方法以及生物传感策略等方面的参考,并展望了以适配体功能化DNA纳米结构为材料的生物传感器的应用前景。     

流泪的滋味

当你流泪的时候,你就会觉得身边的一切都令人心酸当你想痛快地大哭一场的时候,你就会明白眼泪是多么的可贵当我们抱在一起大哭,我深深地感受到这一刻,幸福是那么的令人陶醉等哭完冷静下来,我终于体味到流泪的个中滋味,为了它我奢侈地想再哭一回眼泪呀,你为何那样珍贵珍贵到可以与珍珠相媲美眼泪呀,我多想一个人自私地拥有你可是无奈的是流泪谁都会是的,流泪谁都会可是一生中又有谁痛痛快快地哭过几回幻想着,幻想着还能有一次机会让我酣畅淋漓地哭一回我会把流泪的滋味反复回味流泪的滋味@坊郭晴$西安铁一小童心文学坊!710015西安市西闸口19…     

Determination of Polysaccharide in Radix pseudostellariae Extract by Size-Exclusion High-Performance Liquid Chromatography

A simple size-exclusion high-performance liquid chromatographic method was developed for rapid molecular mass screening to determine the average molecular mass, polydispersity, and quantity of Taizishen polysaccharides extract. The screening used a TOSOH TSK-GEL G3000SW high-performance liquid chromatographic column with 0.1 mol/L NaNO3 buffer as the mobile phase and refractive index detec- tor. The molecular mass calibration curve was linear for polysaccharide standards from 10 to 100 kDa with a correlation coefficient of 0.9991. The method can be used to analyze the quantity, average molecular mass, and polydispersity of polysaccharides. In addition, the screening method is suitable for quality control of polysaccharide preparations in Chinese medicines and pharmaceutical products.     

班主任工作漫谈

班主任所面对的是成长中的、充满生命活力的青少年,主要是"人的培养"而不是"知识的传递"看作教育的终极目标,她的工作就会不断地向自己的智慧、人格、能力发出挑战,推动她学习、思考、探索,给她的生命增添发现、成功的欢乐.     

A nonenzyme glucose sensor based on Cu/Ni/CMWCNTs nanocompositesEI北大核心CSCD

Copper-nickel bimetallic nanoparticles decorated on carboxylated multi-walled carbon nanotubes （Cu/Ni/CMWCNTs）were prepared by using a simple one-pot solvothermal method,which was then employed to construct a highly sensitive non-enzymatic glucose sensor. The modified electrode showed high sensitivity and stability in glucose detection,which was mainly attributed to the synergistic effect of the compact copper-nickel nanocomposite and carboxylated multi-walled carbon nanotubes that possessing high specific surface area to increase the number of active sites and to improve the electrocatalytic activity of the modified electrode. The phase structure and morphology of the material were characterized by X-ray diffraction and scanning electron microscope; the electrochemical performance of the sensor was studied by cyclic voltammetry and chronoamperometry. The sensor had a sensitivity of 1949.1 μµA·L/（mmol·cm2）for glucose detection in the linear range of 1.0-8000 μµmol/L at a potential of 0.55 V,and the detection limit was 0.2 μµmol/L. The sensor was also applied to measure the concentration of glucose in serum samples. The developed nanocomposites sensor has the potential prospect to monitor blood glucose. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Crystallographic Studies of Cephalosporin Acylase from Pseudomonas sp. Strain 130

The cephalosporin acylases are a group of enzymes that hydrolyze cephalosporin C and/or glutaryl 7-aminocephalosporanic acid to produce ?-aminocephalosporanic acid. The cephalosporin acylase from Pseudomonas sp. strain 130 was crystallized in two different forms suitable for structural studies. A tetragonal crystal form diffracted to 0.24 nm belonged to the space group P41212. There was one αβ heterodimer per asymmetric unit. A second crystal form diffracted to 0.21nm belonged to the space group P21. There was four αβ heterodimers per asymmetric unit. The tetragonal crystal structure of CA-130 was determined using the multiwavelength anomalous diffraction method and the P21 crystal structure was then determined using the molecular replacement method.     

关于技工院校德育教育问题的几点思考

本文是我在长期从事学生思想品德教育教学实践的基础上总结形成的一些观点,关于德育工作缺乏实效性和出现功利化倾向等问题进行了初步探索。     

德育教育之——心理素质教育

从心理学角度讲：心理素质包括情感,信心,意志力,和韧性等等。一个人的心理素质是在先天素质的基础上,经过后天的环境与教育的影响而逐步形成的。德育工作是塑造学生心灵的工作,心灵的塑造必须以心理健康为基础,必须把健康的心理,健全的人格作为重要目标和内容。