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关键词： ELECTROPHORESIS   DIELECTRIC devices   MICROFLUIDICS   POLYSTYRENE   ELECTRIC fields   OXIDES  

摘要： The authors present dielectrophoresis (DEP)-based tweezers that can be used to characterize the interactions between a particle and the surface it is attached to, within a microfluidic device. As a proof of concept, 5.4 mu m polystyrene beads functionalized by carboxyl group were attached on a bare and poly-L-lysine functionalized oxide surface. Negative dielectrophoresis force was generated using interdigitated electrodes and the peak dielectrophoresis voltage where the beads were repelled away from the surface was used to characterize the strength of interaction between the particle and the surface. Electric field and DEP force calculation were used to corroborate the measured results. (C) 2007 American Institute of Physics.

关键词： gas chromatography   comprehensive two-dimensional   compound classification   chemometric data processing   aerosols   environmental particles   time-of-flight mass spectrometry  

摘要： Comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOF-MS) is useful in analyzing complex samples, such as the semi-volatile organic compounds (SVOC) in daily aerosol samples collected in Augsburg, Germany. For efficient routine analysis, a partial classification system based on mass spectra has been proposed to group compounds into substance classes. Classifiers based on fragmentation patterns, retention time, and spectral transformations are incorporated into software scripts for automated classification. Fragmentation pattern rules are also applied to an aerosol sample analyzed using direct thermal desorption (DTD)-GC x GC-TOF-MS and a non-traditional column combination. (C) 2007 Elsevier B.V. All rights reserved.

关键词： paclitaxel   conjugation   cytotoxicity   prostate cancer  

摘要： Sixteen different taxoid conjugates were prepared by linking various anticancer compounds, including camptothecin (CPT), epipodophyllotoxin (EP), colchicine (COL), and glycyrrhetinic acid (GA), at the 2'- or 7-position on paclitaxel (TXL, 1) through an ester, imine, amine, or amide bond. Newly synthesized conjugates were evaluated for cytotoxic activity against replication of several human tumor cell lines. Among them, TXL-CPT conjugates, 8-10, were more potent than TXL itself against the human prostate carcinoma cell line PC-3 (ED50 = 14.8, 3.1, 19.4 nM compared with 55.5 nM), and conjugate 10 was also 8-fold more active than TXL against the LN-CAP prostate cancer cell line. These compounds also possessed anti-angiogenesis ability as well as lower inhibitory effects against a normal cell line (MRC-5). Thus, conjugates 8-10 are possible antitumor drug candidates, particularly for prostate cancer. (c) 2007 Elsevier Ltd. All rights reserved.

关键词： 检验科   核医学   应急救援  

摘要： 检验科作为一门多学科融合的独立专业，在医院医疗工作中发挥着重要的作用。现结合实际将检验科在核医学应急救援中的作用讨论如下：

关键词： subset selection   type-III error   control population   probability of correct selection   simultaneous confidence intervals  

摘要： Consider k(>= 2) independent populations pi 1,...,pi(k) such that an observation from population pi(i) follows a logistic distribution with unknown location parameter mu(i) and common known scale parameter sigma(2), i = 1,...,k. Let mu([1]) <= ... <= mu([k]) be the unknown ordered values of its and the population associated with mu([k]), be the upper extreme population (UEP) and the population associated mu([1]) be the lower extreme population (LEP). In this paper, we discuss a procedure on the lines of Liu [On a multiple three-decision procedure for comparing several treatments with a control. Austral. J. Statist. 39, 79-97] and Boher [Multiple three-decision rules for parametric signs. J. Amer. Statist. Assoc. 74, 432-437], for classifying k logistic populations by the location parameters as better or worse than a control/standard population. In the absence of any standard/control population, we propose a selection procedure for simultaneous selection of two non-empty random size subsets, one containing population associated with largest mean and the other containing population associated with smallest mean with a pre-specified probability P* (1/k(k-1) < P* < 1). The required selection constants to implement the proposed procedures are tabulated. Using these selection constants, the simultaneous confidence intervals for the parameters mu([i])-mu([1]), i = 2,...,k, mu([k])-mu([i]), i = 1,...,k-1, are constructed. A simple instructive numerical example is given. (c) 2006 Elsevier B.V. All rights reserved.

关键词： 解不等式   应用题   不等式组  

摘要： 　　利用不等式解应用题的步骤与利用方程解应用题的步骤相似:即设未知数、列不等式(组)解不等式(组)、检验、写出答案.但是,同学们很容易忽略检验这一步骤.下面就举例来说明检验这一步骤的重要性和必要性.……

关键词： GPS水准测量   多项式曲面拟合   回归分析   相关性检验   模型优化  

摘要： 多项式曲面拟合实质上是数理统计中回归分析与预测估计的组合运用。将回归分析中在变量间进行相关显著性检验的方法引入到求取转换参数的过程中使用,发现了一个可以减少转换参数总量并实现不低于原标准模型拟合计算精度的数据处理方式。

关键词： 检验批   验收   表格填写   验收制度  

摘要： 随着建设的高速发展,各个地方对工程质量重视程度不同,因此在结合实际进行操作时,不能熟练的按照检查验收的内容和方法进行检查验收。在中间阶段性验收时,发现检验批的质量验收记录,不够详细,也不够及时、真实和准确,达不到新版规范强化管理、过程控制的目的。因此,对检验批的质量验收,应该引起参建各方的重视,以提高检验批验收的操作水平。

关键词： infrared spectroscopy   hierarchical classification ascendant   food analysis   chemometrics   outer product analysis  

摘要： A chemometric analysis has been developed to emphasise the discrimination power of spectroscopic techniques such as near infrared, mid-infrared and visible spectroscopy. The combination of two spectral domains using outer product analysis (OPA) leads to the calculation of an outer product (OP) matrix. The representation of this matrix is called the "analytical fingerprint" of the samples and their classification is performed in the following steps. First, two different techniques are tested by subtracting the images one-by-one and the sum of all the elements of the resulting difference matrix gives a scalar, characteristic of the distance between the two images. Combining chemical analysis with image, processing techniques provides an original approach to study butters and margarines in relation to their fat content. Best results were obtained with the OP matrix built from NIR and visible signals following the use of city-block distance and average linkage. Samples were arranged in four groups: 100%, 82-75%, 70-59% and 38-25% w/w fat. The cophenetic correlation coefficient (validity of the cluster information generated by the linkage function) associated with these spectral data has a value of 0.973. Similar results were obtained using Ward's algorithm which generated four groups and a cophenetic correlation coefficient equal to 0.959. (c) 2006 Elsevier B.V. All rights reserved.

关键词： 解除劳动合同   公共汽车公司   公告   单位   企业发展基金   驾驶员   合同书   案例  

摘要： 【案例】：现年49岁的候某自1999年7月起，受聘于某公共汽车公司（以下简称公汽公司】当驾驶员。双方签订了《聘用劳动合同书》，期限为一年，其中约定候某“缴纳企业发展基金1000元，不予退还”。