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41.
The stellarator W7-X will be equipped with two Neutral-Beam-Injector (NBI) boxes for balanced injection. Each NBI box has 2 tangential and 2 radial source positions. For the experimental start-up phase each NBI box will be only equipped with 2 ion sources. For the selection of the initial 2 NBI source positions per box three physical aspects were examined (transmission and duct power deposition, shine through and heating efficiency).Using hydrogen injection the heating power to the plasma under typically planned conditions should be 1.3 MW for the tangential sources and 1.1 MW for the radial sources (deuterium: 2 MW for the tangential sources, 1.8 MW for the radial sources). The tangential source positions all have similar heating efficiencies. One of them suffers from the lowest duct transmission (highest power-load to the duct). The same source hits a component with a low power-load capability. The W7-X inner wall design will be modified in order to enhance the maximum power-load capability of that component. For the radial source positions there is no clear physics advantage of one position over the other. Taking all aspects into consideration the decision was made to use one tangential source and one radial source per box during the experimental start-up phase.  相似文献   
42.
The effects were determined of adding various combinations of magnesium and sodium chloride plus tetrasodium pyrophosphate on the stability, pH, solubilized protein, chopping times and textural characteristics of raw and cooked meat emulsions.The results of adding different combinations of magnesium and sodium chloride were quite similar whether ionic strength or chloride ion concentration was kept constant.Emulsion stability and raw emulsion pH were reduced with increased proportion of added magnesium chloride. However,the level of solubilized protein found in raw emulsions increased with increasing proportions of magnesium chloride.  相似文献   
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BACKGROUND: We evaluated the efficacy and safety of ketorolac (Toradol). METHODS: In this prospective trial, 88 women in confirmed preterm labor at < or =32 weeks' gestation were randomized to receive magnesium sulfate given as an initial 6 g intravenous bolus followed by continuous infusion therapy (2 to 6 g/hr) or intramuscularly administered ketorolac (60 mg loading dose) followed by 30 mg every 6 hours for a maximum of 24 hours. RESULTS: The study groups were similar with respect to age, parity, cervical status, and gestational age on admission. Ketorolac was more rapid (2.71 hr+/-2.16) in the arrest of preterm labor than was magnesium sulfate (6.22 hr+/-5.65). No patient required discontinuance of either drug due to adverse effects. There was no difference in the incidence of neonatal complications between the two groups. CONCLUSION: In gestations with preterm labor at <32 weeks, ketorolac appears to be an appropriate first-line tocolytic agent.  相似文献   
45.
A transport network layer based on optical network elements   总被引:3,自引:0,他引:3  
An approach to the realization of a broadband, flexible, multiwavelength transport network employing an optical network layer. The design methodology for a network demonstrator is presented, and the transmission, switching, line, and management/supervisory subsystems and components are described  相似文献   
46.
Pigeons (Columba livia) searched for a goal location defined by a constant relative spatial relationship to 2 landmarks. For one group, landmark-to-goal bearings remained constant while distance varied. For another group, landmark-to-goal distances remained constant while direction varied. Birds were trained with 4 interlandmark distances and then tested with 5 novel interlandmark distances. Overall error magnitude was similar across groups and was larger than previously reported for Clark's nutcrackers (Nucifraga columbiana). During training, error magnitude increased with interlandmark distance for constant-bearing but not constant-distance birds. Both groups searched less accurately along the axis parallel to landmarks than along the perpendicular axis. Error magnitude increased with novel extrapolated interlandmark distances but not with novel interpolated distances. Results suggest modest geometric rule learning by pigeons. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
47.
OBJECTIVE: Our purpose was to prospectively evaluate the interobserver reliability of digital and endovaginal ultrasonographic cervical length measurements. STUDY DESIGN: Forty-three women were recruited from our antepartum clinic to participate in this study. Two independent and blinded digital cervical examinations were performed by the first author and a second examiner. Instructions were given to estimate the cervical length in millimeters. After micturition endovaginal ultrasonographic cervical length measurements were performed by two independent, blinded registered diagnostic medical sonographers. Cervical lengths were compared with the Student t test and Pearson's correlation coefficient. A kappa statistic was calculated for interobserver reliability at three levels of agreement +/- 1 mm, +/- 4 mm, and +/- 10 mm. Data are expressed as means +/- SD. RESULTS: Digital cervical lengths were not different between the two examiners (18.7 +/- 4.8 mm, 20.5 +/- 6.2 mm) nor between the two ultrasonographic measurements (38.6 +/- 6.1 mm, 39.2 +/- 5.4 mm). The digital cervical lengths agreed (+/- 1 mm) 35% of the time (R2 0.10, p = 0.02). The endovaginal ultrasonographic measurements agreed (+/- 1 mm) 74% of the time with a stronger correlation (R2 0.53, p = 0.0001). The kappa statistic for interobserver variability was marginal for both digital and endovaginal cervical length measurements when agreement was defined as +/- 1 mm. Endovaginal ultrasonography was significantly more reliable than digital examination when agreement between examiners was defined as either +/- 4 mm or +/- 10 mm. CONCLUSION: Although both digital and endovaginal ultrasonographic cervical length measurements show correlation between examiners, endovaginal ultrasonography is significantly more reliable when agreement is defined as > or = +/- 4 mm. Serial cervical length measurements to predict preterm labor will be enhanced by the interobserver reliability of endovaginal ultrasonography.  相似文献   
48.
在分析了采用ANSYS隐式有限元分析和LS-DYNA显式分析的一般情况之后,得到显式时间积分法对准静态极限荷载分析进行瞬态分析的时间和方式。然后将重点关注隐式分析的优点,探讨如何更有效地将ANSYS和LS-DYNA进行组合,使其能具有更好的瞬态分析效果。最后,概述了模型的离散化,控制方案的选择,缺陷的考虑和结果校核。  相似文献   
49.
Grid‐based simulation usually involves large quantities of data at each stage of the simulation process. These data include simulation input and output files, intermediate results files, log and error files, associated metadata, and information capturing the processes that generate the data. The question of how to effectively store and manage data files within a Grid computing environment is increasingly becoming an important issue. This paper illustrates how we built a lightweight e‐Science infrastructure for data management within a Grid computing environment, including the integration of data curation activities into the entire Grid‐based simulation process. Rather than focusing on specific implementation details, we aim to identify the key issues and research challenges, describing how various existing technologies and tools can be best integrated to address these requirements and challenges. Although the case of quantum mechanical simulation of materials properties is used in the paper, much of the discussion is as generic as possible so that approaches, methods and practice (e.g. integrated approach, workflow taxonomy and development approach, simple but useful semantic annotation approach) can be applied to wider domains and disciplines to facilitat the digital research. A comparison between our approach and Cloud computing, and lessons learned in data management within the Grid computing environment, are also presented. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
50.
Cell polarity is essential for many functions of cells and tissues including the initial establishment and subsequent maintenance of epithelial tissues, asymmetric cell division, and morphogenetic movements. Cell polarity along the apical-basal axis is controlled by three protein complexes that interact with and co-regulate each other: The Par-, Crumbs-, and Scrib-complexes. The localization and activity of the components of these complexes is predominantly controlled by protein-protein interactions and protein phosphorylation status. Increasing evidence accumulates that, besides the regulation at the protein level, the precise expression control of polarity determinants contributes substantially to cell polarity regulation. Here we review how gene expression regulation influences processes that depend on the induction, maintenance, or abolishment of cell polarity with a special focus on epithelial to mesenchymal transition and asymmetric stem cell division. We conclude that gene expression control is an important and often neglected mechanism in the control of cell polarity.  相似文献   
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