A fluorescent derivatization method of proteins for the detection of low‐level impurities by microchip capillary gel electrophoresis

A novel pre‐chip fluorescent derivatization method is presented for protein sizing and quantification by microchip CGE. The derivatization reaction employed a water‐soluble and stable fluorescent dye and was performed under conditions that favored the formation of homogeneous reaction products. The method delivered in terms of protein sizing similar results as microchip CGE with on‐chip staining but showed an extended linear dynamic range for protein quantification encompassing four orders of magnitude. The sensitivity of the method was similar to standard silver‐stained planar gels. The characterization of derivatization reaction products by MS and preparative isoelectric focusing indicated that a constant degree of dye molecule tagging was obtained over a broad range of protein/dye ratios. The method allowed detecting and quantifying an impurity spiked into an antibody preparation down to a level of 0.05%. Advantages of this method compared with CGE approaches with pre‐column derivatization include a shorter analysis time and an increased robustness and ease of use.     

Rational design for variability minimization in bioanalytical method validation: illustration with LC-MS/MS assay method for terbinafine estimation in human plasma

Terbinafine, a widely used antifungal drug, is a challenging molecule for quantitative bioanalysis due to certain factors contributing assay variability. Despite previous attempts at human plasma determination of terbinafine, exhaustive stability of the drug or an internal standard was lacking. Internal standard stability with negligible variation throughout the analysis is an indicator of a reliable bioanalytical method as the majority of LC–MS/MS assays are based on analyte/IS response ratios for quantitation. A newly developed high‐throughput simple LC‐MS/MS method is described for human plasma determination of terbinafine using naftifine internal standard and eluting all compounds within 2 min. A solid‐phase extraction of terbinafine achieving mean recovery of 84.3% (CV < 4%) without compromising sensitivity (limit of quantitation 5.11 ng/mL) or linearity (5.11–3014.19 ng/mL) is delineated in this paper. A heated nebulizer in positive multiple reaction monitoring mode was employed with transitions m/z 292.2 →141.1 and 288.2 →117.0 for terbinafine and naftifine, respectively, resulting in excellent chromatographic separation on a Hypurity Advance (50 × 4.6 mm, 5 µm) column. The developed method was successfully applied to clinical samples and for the first time demonstrated marked improved extraction efficiency and reliable long‐term plasma stability results without any internal standard response variation during the entire course of study. Copyright © 2010 John Wiley & Sons, Ltd.     

高岭石插层效率评价

用基于X射线衍射分析(XRD)的插层率、基于热重分析(TGA)的热失重率和基于红外光谱分析(FTIR)的3 600 cm^-1谱带与3 700 cm^-1谱带强度比值对高岭石/二甲基亚砜(DMSO)插层复合物和高岭石/N-甲基甲酰胺(NMF)插层复合物的插层效率进行了综合评价。结果表明,当插层反应进行到1、6和25 d,高岭石/DMSO的插层率分别为5%、52%和89%;而高岭石/NMF的插层率则分别为93%、94%和95%。与此同时,高岭石/DMSO的热失重率分别为1.06%、8.06%和17.46%;而高岭石/NMF的失重率分别为6%、6.5%和14.2%。在红外光谱图中,高岭石/DMSO复合物的3 600与3 700 cm^-1带强度比分别为1.03,1.141和1.628,而高岭石/NMF复合物分别为1.403,1.433和1.612。3种评价方法显示很好的一致性,相对而言,在插层作用的初期,XRD方法比较灵敏,而在插层作用的后期,TGA和FTIR方法则显得更为灵敏和有效。     

Are multi-criteria decision-making tools useful? An experimental comparative study of three methods

Many decision makers still question the usefulness of multi-criteria decision-making methods and prefer to rely on intuitive decisions. In this study we evaluated a number of multi-criteria decision-making tools for their usefulness using incentive-based experiments, which is a novel approach in operations research but common in psychology and experimental economics. In this experiment the participants were asked to compare five coffee shops to win a voucher for their best-rated shop. We found that, although the usefulness of different multi-criteria decision-making tools varied to some extent, all the tools were found to be useful in the sense that, when they decided to change their ranking, they followed the recommendation of the multi-criteria decision-making tool. Moreover, the level of inconsistency in the judgements provided had no significant effect on the usefulness of these tools.     

一种求解物流设施二次分配问题的混合分布估计算法

为了求解物流设施二次分配问题,提出了一种混合分布估计算法(HEDA)。首先,根据QAP的距离和物流量矩阵信息,提出了一种基于假设物流中心启发式规则的种群初始化方法,用于提高初始种群的质量和算法的搜索效率;其次,针对HEDA的概率模型,提出了一种概率矩阵初始构型生成机制和扰动操作,用于提高算法的全局探索能力;最后,在分析QAP的结构性质的基础上,设计了一种基于快速评价的局部搜索策略,用于提高算法的局部开发能力。仿真计算实验和算法比较验证了HEDA的优化性能。     

蕴含权重的偏序集多准则决策法

针对偏序集方法不能解决含有权重的多准则决策问题,提出一种“隐式”赋权的偏序决策方法。首先将含有m个方案和n个准则的决策问题表示成偏序集,之后按权重由大到小的顺序,对准则进行逐步相加形成n个新的准则,得到一个新的偏序集。根据偏序集间的包含关系,证明了新偏序集不仅蕴含了权重信息,而且比初始偏序集有更强的排序能力。结果表明,该法在应用中仅需获取权重排序信息,无需精确权重,适用于权重难以确定的多准则决策问题。以三峡库区水质评价为例,例子表明新方法明显优于原有的偏序决策方法,能够对13个方案进行聚类和排序,而原有方法在该例中几乎难以应用。     

PLS-DEMATEL方法及其应用研究——以组织敏捷性的IT影响因素分析为例

DEMATEL(决策试验与评价实验室)方法是一种在影响因素关联关系评估的基础上,进行影响因素识别与区分的方法。但现实中的管理问题影响因素众多,通过专家打分准确评估影响因素关联关系难度较大,这限制了DEMATEL方法的应用。基于此,本文先采用基于偏最小二乘(PLS)的结构方程方法计算的路径系数来得到影响因素直接关联矩阵,降低了获取直接关联矩阵的难度,再运用传统的DEMATEL方法进行影响因素分析,从而提出了PLS-DEMATEL方法。然后把PLS-DEMATEL方法运用于组织敏捷性的IT影响因素分析的案例研究中,在为增强组织敏捷性提供IT战略支持的同时,也对PLS-DEMATEL方法的实效性进行了验证。     

基于SPA-TOPSIS方法的能源结构优化程度评价

以能源低碳化发展为基础,从社会经济发展程度、能源规划合理程度、环境和谐程度三个准则层入手,构建能源结构优化程度评价指标体系。运用改进惯性权重的PSO算法确定评价体系权重,并基于SPA-TOPSIS法构建能源结构优化程度评价模型,对30个省、自治区、直辖市的区域能源结构优化程度进行实证研究。实证结果表明:区域社会经济发展水平对能源结构优化程度有直接影响,且各区域能源结构优化程度差异较大,总体呈现“东高西低”的格局;清洁能源消费占比、原煤消费占比、烟尘排放等因素对能源结构优化程度影响显著。     

世界经合组织金融素质测量工具的实用性评估——基于甘肃省辖集中连片特殊困难地区实地调查

为了推进国家间国民金融素质比较研究,世界经合组织(OECD)构建了标准化的跨国金融素质测量工具,目前该工具已被30多个国家采信,对于后发国家具有重要的借鉴意义。然而,金融素质是高度情境化的构念,测量工具的情境化是保证测量结果稳健可靠的必要环节。为此,本文实施了针对该工具措辞和计分体系的实用性调查,此次调查的对象分别为相关领域专家和甘肃省辖集中连片特殊困难地区农户,旨在为该工具中国化的路径选择提供佐证。调查结果显示,对于受访农户而言,该工具中“通货膨胀的认知”等5个问题的措辞过于复杂,需要进一步修正;不同类型专家对该工具各构成要件的重要性评估未形成一致意见,需要进一步探寻上述差异产生的原因及其可能的弥合方式。     

基于关系网络的大规模交互式群体评价方法

针对大规模交互式群体评价中如何实现群体意见的有效集结问题,以关系网络为切入点,提出了一种基于关系网络结构的群体评价方法。首先,将评价者视为网络节点,并通过计算节点之间的正负相关系数来构造关系矩阵;其次,设计节点中心度和子群凝聚度,以度量节点和子群的重要性;然后,测量群体评价信息的一致性和稳定性,以此确定交互终止条件;最后,引入阶段权重以集结交互阶段的评价信息,并对最终结果排序。算例验证了该方法的适用性和有效性。