An aqueous extract of Liu Wei Di Huang Wan alters the labeling of blood constituents with Technetium-99m

The Liu Wei Di Huang Wan is a formula of a traditional Chinese medicine that is used to treat asthma patients and has been shown to have several important properties,such as antioxidant and free radical scavenging activities.The influence of an extract of Liu Wei Di Huang Wan on the labeling of blood constituents with technetium-99m was investigated.Anticoagulated blood(Wistar rats) was incubated with the extract,stannous chloride and technetium-99m,as sodium pertechnetate.Samples were centrifuged and aliquots of plasma and blood cells were separated and precipitated with trichloroacetic acid,to obtain soluble and insoluble fractions of the blood constituents.The percentage of radioactivity(%ATI) in all the fractions was determined.The analysis of the results shows that the extract at the highest concentration used(70 mg/mL) decreased significantly(P<0.05) the %ATI(from 96.48 ± 1.19 to 54.46 ± 7.38) on blood cells compartment,(from 81.11 ± 4.15 to 61.33 ± 4.74) on insoluble fractions of blood cells and(from 65.91 ± 2.44 to 13.15 ± 3.62) on insoluble fractions of plasma.In conclusion,the results suggest that the substances present on this extract can alter this labeling process,probably due to(i) redox properties(antioxidant and chelator activities) and/or(ii) specific actions in the binding sites where the 99mTc would be bound on the blood constituents.As a consequence,precaution is suggested on the interpretation of the nuclear medicine results from performed with blood constituents labeled with 99m Tc in patients that have undertaken LWDHW,although the current findings were obtained in experimental animal models.     

Tween-modified suspension array for sensitive biomolecular detection

Suspension arrays are attracting increasing interest for detecting and quantifying proteins, nucleic acids and other biomolecules. Among various suspension arrays, sillica-based suspension arrays which benefit from low fluorescence background and material stability have been widely used. Sillica-based suspension arrays are often manufactured with the popular aldehyde-aminosilane chemistry for the attachment of a variety of biomolecules. One drawback of this immobilization strategies is the relatively high array particles lost efficiency when washed by centrifugation. Due to this shortcoming, it is low reproductivity and limited in multiplex assay. Herein we report a novel method to fabricate Tween-coated suspension sillica particles, which could achieve good- reproductivity and the low limit of detection. Tween surfactants, each containing hydrophilic ethylene glycol head groups and a hydrophobic alkyl tail, prevent silica particles from being adsorbed onto the centrifuge tube wall and make beads resuspended well. Also, Tween with low fluorescence background could reduce non-specific protein adsorption. Also Tween surfactants are economic and facile agent. In this study, we demonstrate the preparation of the protein array to substantiate the applicability of our approach. Under the optimized experiment conditions, the limit of detection of our Tween-modified particles is as low as 50 pg/mL, which is sufficiently low for the current methods. We believe that the proposed method could provide a perspective on the improvement of self-encoded silica particle arrays.     

全球清洁能源产业链条上，中国在哪儿

一份报告引发的思考 美国皮尤慈善信托基金会2011年发布的报告《全球清洁能源：价值2．37万亿美元的机遇》预测,未来十年中国将保持其作为清洁能源项目投资首要目标市场地位。随着中国采取更为强硬的清洁能源政策,到2020年中国吸引的投资将达到6200亿美元,远远超出20国集团的绝大部分国家。中国迅速崛起的清洁能源行业,促使可再生能源投资的重心在未来十年从西方转向东方。     

一种实用的RS-232电平检测电路

给出了一个采用1.2 μm BiCMOS工艺设计的检测RS-232电平是否有效的电路.电路由施密特触发器、或非门单元以及经过改进设计的能够实现30 μs延迟的电容充放电回路组成.该电路结构简单,功能完善,能够将检测到的持续30 μs以上的无效信号在输出端以低电平输出,并作为使能信号给芯片内部,关断电荷泵和发送器,节省功耗.     

刘翔打破110m栏世界纪录的时间特征分析

运用信息技术为主的方法,以刘翔雅典奥运会平男子110 m栏世界纪录为参照,对刘翔洛桑破世界纪录的时间特征进行了比较分析.研究指出,雅典奥运会后,刘翔通过训练,提高了加速能力和过栏能力,改进了栏间节奏,这是刘翔成功打破世界纪录主要原因.同时指出,刘翔过栏平均时间水平与世界优秀运动员存在一定差距,其速度耐力水平还有待于提高.进一步改进跨栏步技术,提高跑跨结合能力和速度耐力水平.应成为刘翔今后一段时间训练工作的重点.     

二线制4～20mA电流环电路的设计

本文介绍了一种基于ARM芯片的二线制4～20mA电流环输出电路,给出了ARM7芯片与AD421连接的硬件及软件设计     

99mTc标记的一种抗植物蛋白抗体及其生物分布

通过对比几种标记方法,选择预亚锡化法对一种抗植物蛋白抗体进行99mTc标记,标记条件相对简单,初始标记率约为65%,经Sephadex G25凝胶柱纯化后该标记抗体的放射化学纯度达到80%以上.进一步研究了标记配合物在正常小鼠以及荷瘤(H22)小鼠体内的生物分布.生物性能研究表明:99mTc标记的抗体在小鼠体内主要经肾代谢,其在肿瘤内有一定的初始摄取,且清除较慢;靶与非靶比值随时间的增加而提高.但遗憾的是该标记配合物仍存在血液本底较高的缺点,希望通过进一步对该抗体片断的标记研究为肿瘤的早期诊断提供一种新的显像剂.     

永远的接力棒

时光倒流,定格在20世纪80年代中叶。 一天下午,我正在家中读书,周一良老师突然来访。我一阵惶恐、忙乱,一良师依旧是一片淡定的笑容。听了来意,方知这一次老师的“下访”,是来约稿的。原来,“文革”之前,一良师曾在周扬同志的领导和关切下,主持过世界史教材的编撰。     

跨栏跑技术的研究综述

本文采用文献资料研究法,对110m跨栏跑技术的研究资料进行综合性探讨分析.结果表明,平跑速度是决定跨栏跑速度的主要因素,而跨栏跑技术成为又一重要影响因素;最大栏间速度快,以高速跑完全程是世界跨栏跑全程跑技术的发展趋向;过栏时间短、摆动腿摆动快、起跨攻栏水平速度大、下栏距离小是现代跨栏步技术的特征;栏间步长比例合理、节奏稳定有利于跨栏跑技术的提高.     

男子400m跑节奏探析

通过阐述了400m跑人体的能量来源、供能的过程以及对第6,7届世界田径锦标赛男子400m决赛选手全程和分段成绩进行分析,揭示当今世界男子400m跑速度节奏特征及发展趋势。研究认为:扩大无氧糖酵解、机体抗乳酸能力,尤其合理分配体力,匀速的节奏跑,是训练工作中应抓好的主要环节。