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关键词： 主成分分析   土壤   分类  

摘要： 采用火焰原子吸收光谱法对江西省南丰县南丰蜜桔种植区和非种植区土壤中锰、铜、锌、钴、镍5种元素的含量进行测定;用电位滴定法测定上述土壤样品的酸度;用灼烧法测定其中有机物质的含量;用干燥法测定自然水的含量。进而采用主成分分析法(PCA)对所测得的土壤样品的8个变量进行分类研究,发现蜜桔种植区和非种植区的样品能得到较好的分离识别,证明南丰蜜桔的质量与土壤中的微量元素的含量、有机物质的含量以及土壤的酸度之间存在相关性。

关键词： pattern recognition   capillary electrophoresis   toxicology   support vector machines  

摘要： In toxicology, hazardous substances detected in organisms may often lead to different pathological conditions depending on the type of exposure and level of dosage;hence, further analysis on this can suggest the best cure. Urine profiling may serve the purpose because samples typically contain hundreds of compounds representing an effective metabolic fingerprint. This paper proposes a pattern recognition procedure for determining the type of cadmium dosage, acute or chronic, administrated to laboratory rats, where urinary profiles are detected using capillary electrophoresis. The procedure is based on the composition of a sample data matrix consisting of areas of common peaks, with appropriate pre-processing aimed at reducing the lack of reproducibility and enhancing the potential contribution of low-level metabolites in discrimination. The matrix is then used for pattern recognition including principal components analysis, cluster analysis, discriminant analysis and support vector machines. Attention is particularly focussed on the last of these techniques, because of its novelty and some attractive features such as its suitability to work with datasets that are small and/or have low samples/variable ratios. The type of cadmium administration is detected as a relevant feature that contributes to the structure of the sample matrix, and samples are classified according to the class membership, with discriminant analysis and support vector machines performing complementarily on a training and on a test set.

关键词： Q-DAY活动   检疫部门   实验室标准化管理   卫生检验   质量日  

摘要： 对于实验室标准化体系的维护,我们的经验之一是深化ISO17025管理要素中的预防措施,作为管理要素内部审核的补充工作,使体系维护工作程序化,做到重在预防。"Q-day"是Qualityday的缩写,即"质量日"的意思,把每个月的某一天定为"Q-day"活动日,成立了专门的活动小组,轮流安排好每次活动的主题,进行体系检查,总结检查结果,在例会上公布并限期分析改正,下一个"Q-day"对其进行跟进。经过一段时间的运行,发现取得了较好的效果,问题也相应地少了,对体系的维护起到了积极的作用。

关键词： 检验科   预防措施   医院感染   检验报告  

摘要： 我院检验科加强科室自身建设过程中,加强医院感染的管理,充分发挥了在防染工作中的重要作用,使医院感染管理工作得到了可靠的保证,取得一定成效,现介绍如下。1　健全医院感染管理的组织机构我院成立了医院感染办公室,每周不定时下科室督查,加强管理力度,检验科成为防染工作中的主力军,检验科成立了自己的防染小组,负责各科室微生物的监测,监测的重点是感染科室空气消毒及无菌操作制度的落实情况。同时把检验报告单的消毒及各种检验标本的消毒处理工作纳入本科室的重点防染项目。2　加强指导和教育,提高控制感染意识加强科室人员的道德教育,普及医院感染知识,不断更新医院感染意识,根据卫生部制定的《医院感染管理规范》(试行)要求执行,有效地控制医院感染率,制定详细的工作流程,加强无菌观念,有情况及时与相关科室及防染办公室联系,发挥检验科在防染工作中的重要作用。3　检验科控制感染对策3.1　实验室管理　保持工作室整洁,物品放置有序,污染区、清洁区严格区分;保持空气流通、清新,做到卫生用具专室专用;加强对室内空气、墙壁、门窗、地面消毒;每日用0 .2 %～0 .5 %过氧乙酸或健之素2 5 0 0 m g/ L 擦拭表面。3.2　人员防护　检验人...

关键词： 行业标准   检测方法   标准化工作   食品工业   微生物  

摘要： 对SN0168-92、GB4789.2-94ΓOCT29184-91标准中菌落总数的检验方法进行了比较:对SN0169-92、GB4789.3-94、ΓOCT50474-93标准中大肠菌群的检验方法进行了比较;找出了3类标准检验方法的区别,提出了标准不同给检验检疫工作带来的不便,阐述了检验检疫行业标准国际标准化的重要作用。

关键词： PROTEIN-protein interactions   RADIATION chemistry   MOLECULAR association   AMINO acids   PEPTIDES   SPECTROSCOPIC imaging  

摘要： Hydroxyl radical-mediated footprinting coupled with mass spectroscopic analysis is a new technique for mapping protein surfaces, identifying structural changes modulated by protein-ligand binding, and mapping protein-ligand interfaces in solution. In this study, we examine the radiolytic oxidation of aspartic and glutamic acid residues to probe their potential use as structural probes in footprinting experiments. Model peptides containing Asp or Glu were irradiated using white light from a synchrotron X-ray source or a cesium-137 y-ray source. The radiolysis products were characterized by electrospray massspectrometry including tandem mass spectrometry. Both Asp and Glu are susceptible to radiolytic oxidization by y-rays or synchrotron X-rays. Radiolysis results primarily in the oxidative decarboxylation of the side chain carboxyl group and formation of an aldehyde group at the carbon next to the original carboxyl group, giving rise to a characteristic product with a -30 Da mass change. A similar oxidative decarboxylation also takes place for amino acids with C-terminal carboxyl groups. The methylene groups in the Asp and Glu. side chains also undergo oxygen addition forming ketone or alcohol groups with mass changes of +14 and +16 Da, respectively. Characterizing the oxidation reactions of these two acidic residues extends the number of useful side chain probes for hydroxyl. radical-mediated protein footprinting from 10 (Cys, Met, Trp, Tyr, Phe, Arg, Leu, Pro, His, Lys) to 12 amino acid residues, thus enhancing our ability to map protein surface structure and in combination with previously identified basic amino acid probes can be used to examine molecular details of protein-protein interactions that are driven by electrostatics.

关键词： 卫生检验质量   检验人员   卫生防疫站   卫生防疫工作   实验室   整体水平   检验工作   重要作用   重要组成部分   技术水平  

摘要： 卫生检验是我国卫生防疫事业的一个重要组成部分,在各级卫生防疫站中占有重要的地位,检验机构的能力、技术水平以及检验数据的公正性、可靠性直接关系到执法的严肃性和权威性,关系到卫生防疫工作的声誉。随着卫生体制改革的不断深入,卫生检测在卫生防疫站发展中的作用日益突出,卫生检验水平的高低,可以反映一个卫生防疫站的整体水平,

关键词： CONTRACTS   COMMERCIAL law   LEGAL instruments   OBLIGATIONS (Law)   CONTRACT method   LAW  

摘要： For over a century, legal commentators have debated the relative merits of formal and substantive approaches to the interpretation Of contracts;in recent years, the debate has increasingly been conducted in the language of the economic approach to contract law. Mile this new wave of scholarship has been relatively successful in relating the traditional debates over formalism to specific transactional and institutional problems such as imperfect information, it has been less productive in terms of generating useful legal or policy recommendations. This Essay proposes a different approach: one that focuses on private rather than public legal decision makers as its primary audience. In general, private lawmakers are better able to make practical use of the economic analysis of contracts, in part because the detailed information that is necessary to implement such analysis intelligently is likelier to be available at the individual level. Furthermore, there are many opportunities for contracting parties to choose between relatively formal and relatively substantive interpretive regimes. What is needed is a basic taxonomy of economic considerations that can serve as an organizing framework for parties choosing between form and substance when designing contracts. The later Part of the Essay sets out such a framework.

关键词： Support Vector Machines   Classification   Clustering   K-mean  

摘要： Support Vector Machines (SVMs) have gained wide acceptance because of the high generalization ability for a wide range of classification applications. Although SVMs have shown potential and promising performance in classification, they have been limited by speed particularly when the training data set is large. The hyper plane constructed by SVM is dependent on only a portion of the training samples called support vectors that lie close to the decision boundary (hyper plane). Thus, removing any training samples that are not relevant to support vectors might have no effect on building the proper decision function. We propose the use of clustering techniques such as K-mean to find initial clusters that are further altered to identify non-relevant samples in deciding the decision boundary for SVM. This will help to reduce the number of training samples for SVM without degrading the classification result.