首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   850篇
  免费   76篇
  926篇
  2021年   12篇
  2019年   4篇
  2018年   8篇
  2017年   4篇
  2016年   20篇
  2015年   20篇
  2014年   21篇
  2013年   28篇
  2012年   29篇
  2011年   49篇
  2010年   25篇
  2009年   23篇
  2008年   38篇
  2007年   27篇
  2006年   36篇
  2005年   31篇
  2004年   33篇
  2003年   36篇
  2002年   33篇
  2001年   24篇
  2000年   35篇
  1999年   26篇
  1998年   10篇
  1997年   4篇
  1996年   14篇
  1995年   15篇
  1994年   12篇
  1993年   11篇
  1992年   14篇
  1991年   16篇
  1990年   19篇
  1989年   13篇
  1988年   21篇
  1987年   17篇
  1986年   10篇
  1985年   10篇
  1984年   16篇
  1983年   17篇
  1982年   5篇
  1981年   5篇
  1980年   9篇
  1979年   9篇
  1978年   8篇
  1977年   8篇
  1976年   6篇
  1973年   8篇
  1972年   5篇
  1970年   7篇
  1969年   5篇
  1967年   7篇
排序方式: 共有926条查询结果,搜索用时 0 毫秒
131.
JL Hudson  HF Dodd 《PloS one》2012,7(8):e42359

Background

To inform early intervention practice, the present research examines how child anxiety, behavioural inhibition, maternal overinvolvement, maternal negativity, mother-child attachment and maternal anxiety, as assessed at age four, predict anxiety at age nine.

Method

202 children (102 behaviourally inhibited and 100 behaviourally uninhibited) aged 3–4 years were initially recruited and the predictors outlined above were assessed. Diagnostic assessments, using the Anxiety Disorders Interview Schedule, were then conducted five years later.

Results

Behavioural inhibition, maternal anxiety, and maternal overinvolvement were significant predictors of clinical anxiety, even after controlling for baseline anxiety (p<.05). No significant effect of negativity or attachment security was found over and above baseline anxiety (p>.1).

Conclusions

Preschool children who show anxiety, are inhibited, have overinvolved mothers and mothers with anxiety disorders are at increased risk for anxiety in middle childhood. These factors can be used to identify suitable participants for early intervention and can be targeted within intervention programs.  相似文献   
132.
Dodd SR  White IR  Williamson PR 《Trials》2012,13(1):84-16
ABSTRACT: This review aimed to ascertain the extent to which nonadherence to treatment protocol is reported and addressed in a cohort of published analyses of randomised controlled trials (RCTs). One hundred publications of RCTs, randomly selected from those published in BMJ, New England Journal of Medicine, the Journal of the American Medical Association and The Lancet during 2008, were reviewed to determine the extent and nature of reported nonadherence to treatment protocol, and whether statistical methods were used to examine the effect of such nonadherence on both benefit and harms analyses. We also assessed the quality of trial reporting of treatment protocol nonadherence and the quality of reporting of the statistical analysis methods used to investigate such nonadherence. Nonadherence to treatment protocol was reported in 98 of the 100 trials, but reporting on such nonadherence was often vague or incomplete. Forty-two publications did not state how many participants started their randomised treatment. Reporting of treatment initiation and completeness was judged to be inadequate in 64% of trials with short-term interventions and 89% of trials with long-term interventions. More than half (51) of the 98 trials with treatment protocol nonadherence implemented some statistical method to address this issue, most commonly based on per protocol analysis (46) but often labelled as intention to treat (ITT) or modified ITT (23 analyses in 22 trials). The composition of analysis sets for their benefit outcomes were not explained in 57% of trials, and 62% of trials that presented harms analyses did not define harms analysis populations. The majority of defined harms analysis populations (18 out of 26 trials, 69%) were based on actual treatment received, while the majority of trials with undefined harms analysis populations (31 out of 43 trials, 72%) appeared to analyse harms using the ITT approach. Adherence to randomised intervention is poorly considered in the reporting and analysis of published RCTs. The majority of trials are subject to various forms of nonadherence to treatment protocol, and though trialists deal with this nonadherence using a variety of statistical methods and analysis populations, they rarely consider the potential for bias introduced. There is a need for increased awareness of more appropriate causal methods to adjust for departures from treatment protocol, as well as guidance on the appropriate analysis population to use for harms outcomes in the presence of such nonadherence.  相似文献   
133.
Rational design, synthesis, and SAR studies of a novel class of benzothiazole based inhibitors of p38alpha MAP kinase are described. The issue of metabolic instability associated with vicinal phenyl, benzo[d]thiazol-6-yl oxazoles/imidazoles was addressed by the replacement of the central oxazole or imidazole ring with an aminopyrazole system. The proposed binding mode of this new class of p38alpha inhibitors was confirmed by X-ray crystallographic studies of a representative inhibitor (6a) bound to the p38alpha enzyme.  相似文献   
134.
135.
136.
137.
Most perfusion techniques rely on mechanical means to provide blood flow to the isolated organ for maintaining its physiological conditions. The approach usually requires a complicated mechanical system with the associated problems of blood type matching and prevention of blood cell damage. This paper describes a gastrointestinal tract perfusion technique that uses the rabbit's own cardiopulmonary system as the autologous blood supply source. The technique allows for the removal of the complete intestinal loop from the abdominal cavity of the rabbit, and maintains its blood circulation through silastic tubing connections of the catheterized portal vein and cranial and caudal mesenteric arteries. An alternative perfusion site that uses the aorta as the arterial blood supply and the vena cava as the venous return also is described. The isolated perfused GI tract may then be placed in a separate test environment for controlled experiments. For an acute animal test, the approach was found to be a convenient alternative to conventional approaches.  相似文献   
138.
139.
The numbers of coliforms, Enterobacteriaceae and Staphylococcus aureus and the extent of their colonization of the fingers of the defeathering machinery within a poultry processing plant were increased after changes in machinery design and a reduction in the level of chlorination. Such increases and the pattern of contamination suggested that the changes had allowed an endemic flora to develop on the fingers.  相似文献   
140.
Summary Tadpoles and young toads of Xenopus laevis were maintained in aqueous solutions of potassium perchlorate or thiourea (0.005% or 0.01% w/v) for up to 20 months. Metamorphosis of tadpoles was inhibited. Within a short time large well-vascularized goitres developed in both tadpoles and toads. An ultrastructural investigation of some of the follicular epithelial cells of these goitres revealed some unusual cytoplasmic membranous inclusions and a morphological account of these structures is presented. It is suggested that some of these complex membranous inclusions may give rise to cytosomes. The relationship between these complex cytoplasmic organelles is considered together with their possible significance and role in thyroid cell functioning.This work was carried out during the tenure by one of us (R.C.) of a Medical Research Council Scholarship and forms part of a programme of research in amphibian thyroid physiology supported by the Medical Research Council to whom we are indebted for their generous assistance.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号