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   1960533篇
  免费   136985篇
  国内免费   4117篇
耳鼻咽喉   26841篇
儿科学   61470篇
妇产科学   53479篇
基础医学   279264篇
口腔科学   58462篇
临床医学   173602篇
内科学   377649篇
皮肤病学   43131篇
神经病学   151721篇
特种医学   78642篇
外国民族医学   450篇
外科学   304587篇
综合类   40162篇
现状与发展   1篇
一般理论   603篇
预防医学   145176篇
眼科学   45154篇
药学   146246篇
  8篇
中国医学   3980篇
肿瘤学   111007篇
  2018年   21447篇
  2017年   17876篇
  2016年   18967篇
  2015年   22385篇
  2014年   28399篇
  2013年   40360篇
  2012年   58124篇
  2011年   56480篇
  2010年   33340篇
  2009年   33193篇
  2008年   52075篇
  2007年   55494篇
  2006年   56695篇
  2005年   61882篇
  2004年   61716篇
  2003年   55797篇
  2002年   50127篇
  2001年   96110篇
  2000年   97513篇
  1999年   83995篇
  1998年   21088篇
  1997年   18519篇
  1996年   18703篇
  1995年   17791篇
  1994年   16522篇
  1993年   15168篇
  1992年   67206篇
  1991年   65362篇
  1990年   64023篇
  1989年   62129篇
  1988年   56727篇
  1987年   55941篇
  1986年   52311篇
  1985年   50070篇
  1984年   36508篇
  1983年   30803篇
  1982年   16843篇
  1981年   14889篇
  1979年   33577篇
  1978年   23233篇
  1977年   19612篇
  1976年   17791篇
  1975年   19761篇
  1974年   23993篇
  1973年   22699篇
  1972年   21424篇
  1971年   20198篇
  1970年   19027篇
  1969年   17821篇
  1968年   16388篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
23.
24.
25.
26.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
27.
Aims: In neuropsychological evaluations, it is often difficult to ascertain whether poor performance on measures of validity is due to poor effort or malingering, or whether there is genuine cognitive impairment. Dunham and Denney created an algorithm to assess this question using the Medical Symptom Validity Test (MSVT). We assessed the ability of their algorithm to detect poor validity versus probable impairment, and concordance of failure on the MSVT with other freestanding tests of performance validity.

Methods: Two previously published datasets (n?=?153 and n?=?641, respectively) from outpatient neuropsychological evaluations were used to test Dunham and Denney’s algorithm, and to assess concordance of failure rates with the Test of Memory Malingering and the forced choice measure of the California Verbal Learning Test, two commonly used performance validity tests.

Results: In both datasets, none of the four cutoff scores for failure on the MSVT (70%, 75%, 80%, or 85%) identified a poor validity group with proportionally aligned failure rates on other freestanding measures of performance validity. Additionally, the protocols with probable impairment did not differ from those with poor validity on cognitive measures.

Conclusions: Despite what appeared to be a promising approach to evaluating failure on the easy MSVT subtests when clinical data are unavailable (as recommended in the advanced interpretation program, or advanced interpretation [AI], of the MSVT), the current findings indicate the AI remains the gold standard for doing so. Future research should build on this effort to address shortcomings in measures of effort in neuropsychological evaluations.  相似文献   

28.
29.

Objective

To examine whether a healthy weight intervention embedded in the Parents as Teachers (PAT) home visiting program, which was previously found to improve mothers’ body mass index (BMI) and obesity-related behaviors, changed the BMI of preschool children or maternal feeding practices.

Methods

This stratified randomized trial included preschool-aged children at risk for overweight whose mothers were overweight or had obesity (n?=?179). The Healthy Eating and Active Living Taught at Home (HEALTH) intervention was based on the Diabetes Prevention Program. Differences were examined using repeated-measures mixed-ANOVA models.

Results

Compared with PAT usual care, the HEALTH intervention had no effect on children's BMI or maternal feeding practices. However, combined analyses showed that children's BMI percentile decreased (P??=?.007), BMI z-scores were maintained (P??=?.19), and 3 of 8 feeding practices improved over time (P < .05).

Conclusions and Implications

Additional research is needed to assess the effectiveness of PAT to prevent preschool-age obesity using rigorous designs (eg, group-randomized trials) and to identify its active components. HEALTH is ready to be scaled up to prevent maternal weight gain through embedding within the national PAT program.  相似文献   
30.
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