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1.
《Planning》2019,(6)
减少手术创伤始终是快速康复的决定性因素,这一点在目前的加速康复外科研究尤其是复杂手术,如妇科肿瘤手术中尚未得到充分重视。尊重学习曲线、全面规划手术方案、总结失利经验、开展前瞻性研究是解决此问题的主要方案。本文着重讨论妇科肿瘤手术创伤对术后加速康复的影响及可能的改进措施。 相似文献
2.
针对辽河油区超稠油采油污水的特点,采用Fenton试剂催化氧化,对采油污水处理进行研究。实验研究及现场应用结果表明,此方法对污水的CODCr具有良好的去除效果。处理后污水经过简单生化,进一步降解污染物,能够实现稳定迭标排放,且具有能耗低、运行成本低和操作简单等特点。 相似文献
3.
迷宫螺旋泵和密封工作特性研究 总被引:1,自引:1,他引:0
介绍了一种实测迷宫螺旋泵和密封工作特性的实验方法,通过该方法可以测得迷宫螺旋泵的泵送特性曲线、迷宫螺旋端面组合密封的最大密封压力以及端面开启的开始转速,具有一定的实用价值。 相似文献
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通过对国际岩石力学委员会JV 公式的论证 ,指出了该公式不符合数理逻辑。结合工程勘察实践 ,拟建了Ky新公式 ,提高了工程岩体完整程度评价方法的科学性。 相似文献
7.
Takahiro Hoshino 《Computational statistics & data analysis》2008,52(3):1413-1429
The estimation of the differences among groups in observational studies is frequently inaccurate owing to a bias caused by differences in the distributions of covariates. In order to estimate the average treatment effects when the treatment variable is binary, Rosenbaum and Rubin [1983. The central role of the propensity score in observational studies for causal effects. Biometrika 70, 41-55] proposed an adjustment method for pre-treatment variables using propensity scores. Imbens [2000. The role of the propensity score in estimating dose-response functions. Biometrika 87, 706-710] extended the propensity score methodology for estimation of average treatment effects with multivalued treatments.However, these studies focused only on estimating the marginal mean structure. In many substantive sciences such as the biological and social sciences, a general estimation method is required to deal with more complex analyses other than regression, such as testing group differences on latent variables. For latent variable models, the EM algorithm or the traditional Monte Carlo methods are necessary. However, in propensity score adjustment, these methods cannot be used because the full distribution is not specified.In this paper, we propose a quasi-Bayesian estimation method for general parametric models that integrate out the distributions of covariates using propensity scores. Although the proposed Bayes estimates are shown to be consistent, they can be calculated by existing Markov chain Monte Carlo methods such as Gibbs sampler. The proposed method is useful to estimate parameters in latent variable models, while the previous methods were unable to provide valid estimates for complex models such as latent variable models.We also illustrated the procedure using the data obtained from the US National Longitudinal Survey of Children and Youth (NLSY1979-2002) for estimating the effect of maternal smoking during pregnancy on the development of the child's cognitive functioning. 相似文献
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Hitsman Brian; Borrelli Belinda; McChargue Dennis E.; Spring Bonnie; Niaura Raymond 《Canadian Metallurgical Quarterly》2003,71(4):657
The authors conducted a meta-analysis of published studies to (a) evaluate the premise that a history of major depression is associated with failure to quit smoking and (b) identify factors that moderate the relationship between history of depression and cessation outcome. Fifteen studies met the selection requirements and were coded for various study methodology and treatment characteristics. DSTAT was used to calculate individual study effect sizes, determine the mean effect size across studies. and test for moderator effects. No differences in either short-term (≤ 3 months) or long-term abstinence rates (≥ 6 months) were observed between smokers positive versus negative for history of depression. Lifetime history of major depression does not appear to be an independent risk factor for cessation failure in smoking cessation treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
Using meta-analysis, randomized experiments in education that either clearly did or clearly did not experience student attrition were examined for the baseline comparability of groups. Results from 35 studies suggested that after attrition, the observed measures of baseline comparability of groups did not differ more than would be expected given sampling error. The degree of either overall or differential attrition did not relate to baseline comparability, a finding that held under sensitivity analyses. Also, both overall and differential attrition rates were unrelated to posttest effect sizes. All of these analyses, however, lacked sufficient statistical power to detect small but potentially meaningful effects. Results suggest caution is warranted when applying quality scales and other blanket rules pertaining to attrition that are meant to either serve as inclusion-exclusion criteria or in scoring study quality. Much greater attention is needed to both the reporting of attrition in primary studies and to the development of conceptual and empirical models of the attrition process. These developments would aid further investigation of the relation between attrition and study outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献