Flow-induced release of adenosine 5′-triphosphate from endothelial cells of the rat mesenteric arterial bed

Adenosine 5-triphosphate (ATP) was released into the perfusate of rat isolated mesenteric arterial beds during each of two consecutive increases in flow. There was no significant difference between the amounts of ATP released on each occasion. Substance P was also released into the perfusate by increased flow, although its release was more variable. Removal of the endothelium of the mesenteric vessels with sodium deoxycholate led to a significant reduction (74%) in the amount of ATP released compared with the release before the endothelium had been removed. This suggests that the ATP released into the mesenteric arterial perfusate during increased flow arises from endothelial cells.     

Determination of erythrocyte pyrimidine 5′-nucleotidase activity by31P nuclear magnetic resonance: Comparison of normal controls and multiple sclerosis patients

Summary A technique to assay erythrocyte pyrimidine 5-nucleotidase activity in situ using³¹P nuclear magnetic resonance spectroscopy is presented. The assay is chemically specific, simple and applicable to untreated lysates. A comparison of enzyme levels in normal controls and in multiple sclerosis patients employing the assay yielded no significant differences between both groups. Difficulties encountered in the quantitative analysis of the assay using¹H-NMR spectroscopy are briefly discussed.     

白沙县黎族贫困山区中学生参加课外体育活动的动机调查与分析

通过实地考察、问卷调查、文献资料、座谈和统计,对白沙县黎族贫困山区中学生参加课外体育活动的情况进行调查,结果显示白沙县黎族贫困山区中学生参加课外体育活动的动机主要是为了提高学习效率、丰富生活情趣、增强体质,兴趣趋向集中于健身性、健美性、趣味性、娱乐性和竞技性.     

鸡脑P物质的制取及分析

P物质是一种广泛存在于哺乳动物中枢及外周神经元系统中的11肽。采用有机溶剂分级法提纯鸡脑P物质,紫外分光光度计测定含量,聚酰胺薄膜层析分析氨基酸组成。结果表明:鸡脑P物质的氨基酸组成和N端氨基酸与资料中完全一致。     

宿根福禄考组织培养技术与快繁研究

本文利用组织培养技术研究宿根福禄考的快速繁殖，为大量培育宿根福禄考种苗提供可靠方法。所用适宜诱芽培养基为：ＭＳ＋６－ＢＡ３ｍｇ／ｌ＋ＮＡ·０．１ｍｇ／ｌ＋糖３０ｇ／ｌ＋琼脂６ｇ／ｌ；适宜生根培养基为１／２ＭＳ＋肌醇全＋有机物全＋１／２Ｆｅ盐＋ＮＡＡ０．５ｍｇ／ｌ＋糖１５ｇ／ｌ＋琼脂６ｇ／ｌ；适宜过渡移栽基质训：珍珠岩／沸石＝１：１。     

MUSICAM算法仿真及DSP实现

介绍了ＭＰＥＧ声音压缩编码采用ＭＵＳＩＣＡＭ算法的计算机仿真过程及用定点ＤＳＰ实现这种算法的结果，并给出编解码器各子功能块所占运算量和存储器容量。     

从耗散结构理论看体育学习的有序性

本文以耗散结构理论为依据，以体育教学论为根本出发点，分析了体育教学过程中体育学习的耗散结构特征．认为体育学习过程就是耗散结构的形成过程，是一个从无序向有序，从低级有序向高级有序的转化过程．     

基于J2ME的移动银行混合加密方案

移动网络的安全性是移动银行发展的关键,数据加密技术则是保证移动网络安全的主要技术之一,设计合理的数据协议、加密方案对移动银行发展具有很重要的意义。考虑到移动银行实现方式、传输数据量等因素,提出了基于无线消息与移动多媒体两种类型下混合加密方案,分别给出了两种类型下的数据传输协议、混合加密、混合解密的流程,并给出了两种混合加密方案时间与数据量函数图像,验证了方案的可用性。     

P2P应用的安全体系结构研究

P2P(Peer-to-Peer)技术得到了快速的发展和应用.针对P2P技术的应用特点,对Peer进行了定义,并对其属性进行了描述.建立了P2P应用的安全体系结构,提出了“一个核心、三个层次、四个接口”的体系结构,通过四个接口为P2P应用提供所需的安全服务,并对安全体系结构的层次关系进行了描述.该体系结构的建立能为P2P应用提供一个通用平台,通过该通用平台,实现对P2P应用系统中各类对象的统一描述,对用户进行鉴别,实现对各类对象的统一权限与授权管理,提供所需的安全服务,从而建立有序、可信的网络环境.     

Attentional negativity bias moderated by positive mood arousal

Automatically allocation of more attention to negative stimuli is called emotional negativity bias. An event-related potentials (ERPs) experiment investigated whether or not this bias was altered by positive mood arousal. The results suggested that the attention bias towards negative stimuli was attenuated when positive information was accessible.