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121.
目的了解GRGDSP/7E3对基质金属蛋白酶(MMP-2,MMP-9)mRNA表达的影响。方法体外培养人脐静脉内皮细胞,分别用酶谱法和逆转录聚合酶链式反应(RT-PCR)检测MMP-2,MMP-9活性和mRNA表达。待细胞融合成单层后,分别加入无血清培养基、静息期血小板、活化后血小板及interleukin-1β(IL-1β),共同培养60min后,洗去血小板,内皮细胞继续培养6h。上清液及细胞分别用于酶谱法检测MMP-2和MMP-9活性,以及RT-PCR分析mRNA表达。结果内皮细胞与活化血小板共同培养后,酶谱法显示:与对照组相比,未活化的血小板轻微诱导MMP-2和MMP-9分泌,而活化状态的血小板能显著诱导这二者的分泌,与IL-1β的作用相当;而且还可以见到62kDaMMP-2活化形式。加入阻断剂GRGDSP以及GPⅡb/Ⅲa单克隆抗体(7E3)作用后检测发现,MMP-2和MMP-9分泌减少。与活化血小板共同培养后的内皮细胞表面表达uPAR和MT1-MMP以及上清液中MMP-2的mRNA与对照组相比明显增高,而静息状态的血小板作用不显著。加入GRGDSP或7E3后,mR-NA的表达降低。结论①活化状态的血小板与IL-1β的作用相当,能显著诱导MMP-2和MMP-9分泌;能明显增高内皮细胞(EC)-uPAR和MT1-MMP及上清液中MMP-2mRNA的表达;②GPⅡb/Ⅲa阻断剂可能抑制血小板在不稳定斑块部位聚集、粘附等一系列炎症反应。  相似文献   
122.
合流污水经处理达到工业循环冷却水水质指标后,可用作泵站循环冷却水。该文介绍了污水处理的工艺流程和方法,以及与采用自来水作冷却水的成本比较。  相似文献   
123.
The authors provide an overview of optimal scaling results for the Metropolis algorithm with Gaussian proposal distribution. They address in more depth the case of high‐dimensional target distributions formed of independent, but not identically distributed components. They attempt to give an intuitive explanation as to why the well‐known optimal acceptance rate of 0.234 is not always suitable. They show how to find the asymptotically optimal acceptance rate when needed, and they explain why it is sometimes necessary to turn to inhomogeneous proposal distributions. Their results are illustrated with a simple example.  相似文献   
124.
商业秘密能够给权利人带来巨大的经济价值或竞争优势,因此要加强对商业秘密的保护,尤其是要加强对雇佣关系中的商业秘密的保护。在雇佣关系中,商业秘密权的保护与择业自由权的保护存在着冲突,是保护商业秘密的难点。竞业禁止作为保护商业秘密的手段,同时存在于在职期间和离职后,雇主通常与雇员签订竞业禁止协议来保护商业秘密,如何确认竞业禁止协议的合法性、合理性问题是保护商业秘密的又一个难点。  相似文献   
125.
A new sampling inspection system involving normal and tightened plans is presented. Performance measures are developed. The average sample number of the newly developed system is compared with those of existing plans. Procedures are indicated an tables are constructed for designing the system indexed by various combinations of parameters.  相似文献   
126.
Maints auteurs ont affirmé que la race et le sexe repreésentent des bases de fractions de classe en ce sens que leur construction sociale permet à des segments d'une classe de se constituer à partir de caractéristiques liées à la race et au sexe. Cependant, les études ernpiriques antérieures tendent à considérer seulernent la race et le sexe comme des facteurs de fractionnernent au sein de la classe ouvrière seulement. À l'aide des données du recensement de 1986, cette communication analyse lea effets interactifs de la race et du sexe sur le revenu considéré comme facteur de fractionnement des classes. Les recherches de l'auteur indiquent que les effets produits par le groupement par race et par sexe sont inégaux en ce qui trait au revenu, les hommes gagnant davantage que les femmes tout en étant davantage ‘fractionnés’ par le revenu que les femmes. Lorsqu'on fait abstraction des différences de revenu entre classes, la race et le sexe demeurent des facteurs explicatifs importants du niveau de revenu, bien que leurs effets soient plus marqués chez les cadres, les professionnels et les ouvriers. L'écart entre les sexes est plus prononcé, mais la race demeure importante comme facteur de fractionnement au niveau des revenus des homrnes, měme après correction pour tenir cornpte d'autres variables. L'auteur affirme que l'assimilation des relations de sexe et de race aux relations entre classes est insatisfaisante et qu'il existe de sérieuses considérations théoriques pour considérer que les causes des inégalités entre les sexes et les races se trouvent non seulement à l'intérieur du domaine de la production, mais également à l'extérieur de celui-ci. The literature has argued that race and gender are bases of class fractions in that their social construction enables segments of a class to be constituted on racialized and gender-linked characteristics. However, previous empirical works tend to consider race or gender as fractionalizing the working class only. Using the 1986 Census data, this paper analyses the interactive effects of race and gender on earnings as grounds of fractionalizing classes. The findings indicate that race and gender groupings produce unequal effects on earnings: males have an income advantage over females, but race fractionalizes the earnings of men to a greater extent than for women. When inter-class differences in earnings are removed, race and gender remain important in explaining earnings, although their effects are stronger among the managerial, the professsional, and the working class. The gender gap is more pronounced, but race remains important in fractionalizing the earnings of men even after controlling for other variables. The paper argues that it is insufficient to subsume gender and race relations under class relations, and that there are compelling theoretical grounds to consider gender and race inequality as having roots both within and outside the sphere of production.  相似文献   
127.
The work-welfare nexus is essential in all social policy regimes. The question is in what situations individuals should be entitled to social welfare benefits and in which situations they should be obliged to work. Social welfare law and administrative practices define mechanisms that separate the deserving poor from people able to work. This article analyses the functions and character of these "separation mechanisms" in Sweden during three periods in history: a) in rural society in the late 19th century; b) in industrial society during the successful years of the Swedish model from World War II until the late 1970s; and c) the present, including the period of welfare retrenchment and reconsideration since the early 1980s. The conclusion is that Swedish social policy has always been strongly work-oriented, but the specific form and content of the work ethic has varied under the influence of different ideologies and handled in different social policy institutions. Under specific conditions the work line has been either generous or restrictive and it has been based on structural attempts to improve the opportunities to work as well as on attempts to strongly pressure the individual to work. The work line of today is seen as an interesting attempt to combine an effort to create good work through improved work conditions and an effort to reinforce elements of work enforcement in the social insurance system.  相似文献   
128.
129.
The problem of determining the number of multi-type protection devices and their locations on electrical supply tree networks with subtree dependency is investigated. The aim is to reduce the amount of inconvenience caused to customers that are affected by any given fault on the networks. An appropriate implementation of tabu search is proposed. We exploit a variable neighborhood and a soft aspiration level, and we embed a data structure and reduction tests into the search to speed up the process. Computational tests are performed on randomly generated electrical tree networks varying in size and branch complexity with encouraging results.  相似文献   
130.
Summary. Standard goodness-of-fit tests for a parametric regression model against a series of nonparametric alternatives are based on residuals arising from a fitted model. When a parametric regression model is compared with a nonparametric model, goodness-of-fit testing can be naturally approached by evaluating the likelihood of the parametric model within a nonparametric framework. We employ the empirical likelihood for an α -mixing process to formulate a test statistic that measures the goodness of fit of a parametric regression model. The technique is based on a comparison with kernel smoothing estimators. The empirical likelihood formulation of the test has two attractive features. One is its automatic consideration of the variation that is associated with the nonparametric fit due to empirical likelihood's ability to Studentize internally. The other is that the asymptotic distribution of the test statistic is free of unknown parameters, avoiding plug-in estimation. We apply the test to a discretized diffusion model which has recently been considered in financial market analysis.  相似文献   
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