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   66167篇
  免费   5088篇
  国内免费   231篇
耳鼻咽喉   800篇
儿科学   1767篇
妇产科学   1260篇
基础医学   8383篇
口腔科学   1174篇
临床医学   6518篇
内科学   14122篇
皮肤病学   911篇
神经病学   6112篇
特种医学   2202篇
外国民族医学   4篇
外科学   10596篇
综合类   1096篇
现状与发展   1篇
一般理论   73篇
预防医学   6017篇
眼科学   1289篇
药学   4294篇
中国医学   74篇
肿瘤学   4793篇
  2022年   470篇
  2021年   1095篇
  2020年   642篇
  2019年   1079篇
  2018年   1290篇
  2017年   917篇
  2016年   1033篇
  2015年   1158篇
  2014年   1843篇
  2013年   2698篇
  2012年   3931篇
  2011年   4305篇
  2010年   2405篇
  2009年   2221篇
  2008年   3814篇
  2007年   4027篇
  2006年   4031篇
  2005年   4126篇
  2004年   4015篇
  2003年   3665篇
  2002年   3593篇
  2001年   772篇
  2000年   649篇
  1999年   801篇
  1998年   864篇
  1997年   717篇
  1996年   657篇
  1995年   645篇
  1994年   569篇
  1993年   532篇
  1992年   554篇
  1991年   562篇
  1990年   469篇
  1989年   475篇
  1988年   459篇
  1987年   442篇
  1986年   439篇
  1985年   473篇
  1984年   609篇
  1983年   499篇
  1982年   614篇
  1981年   590篇
  1980年   569篇
  1979年   372篇
  1978年   371篇
  1977年   358篇
  1976年   292篇
  1975年   290篇
  1974年   318篇
  1973年   265篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
The bioavailability of a new sustained-release potassium chloride (KC1) tablet, designed for once-a-day dosing, was compared to a KC1 elixir using urinary excretion data. The study utilized 25 male volunteers dosed in a crossover design in a dietary/activity-controlled environment. The regimens consisted of a total of 80 mEq of potassium in three equally divided doses of elixir every 6 hr and a single 80-mEq dose using four 20-mEq sustained-release (SR) tablets. The mean time to maximum rate of potassium urinary excretion was 2.2 hr for the first elixir dose and 5.5 hr after the SR tablet (P < 0.01), thereby supporting the prolonged-release properties of this formulation. After correction for baseline urinary potassium excretion, the mean total 24-hr urinary potassium excretion was 42.18 mEq for the elixir and 40.41 mEq for the SR tablet. The results indicate that the absorption pattern from the SR tablet is equal to three doses of KC1 elixir dosed 6 hr apart.  相似文献   
42.
This paper models the proximate determinants of school attendance and scores on cognitive and educational achievement tests and on school examinations of over 600 schoolchildren from the Control group of a randomized trial in Tanzania, where children in the Intervention group heavily infected with hookworm and schistosomiasis received treatment. The modeling approach used a random effects framework and incorporated the inter-relationships between school attendance and performance on various tests, controlling for children's health status, socioeconomic variables, grade level, and the educational infrastructure. The empirical results showed the importance of variables such as children's height and hemoglobin concentration for the scores, especially on educational achievement tests that are easy to implement in developing countries. Also, teacher experience and work assignments were significant predictors of the scores on educational achievement tests, and there was some evidence of multiplicative effects of children's heights and work assignments on the test scores. Lastly, some comparisons were made for changes in test scores of treated children in the Intervention group with the untreated children in the Control group.  相似文献   
43.
44.
45.
46.
The authors report a new case of abdominal pregnancy with living baby. The analysis of this observation permits to present then the clinical and paraclinical characteristics of this exceptional localization of pregnancy and emphasize the surgical principles involved with its treatment, around the time of the term delivery.  相似文献   
47.
48.
Irritability is often a problem for patients with Post-Traumatic Stress Disorder (PTSD). We describe two cases that illustrate the use of lithium in the treatment of veterans with PTSD who complained of serious problems with irritability or angry outbursts. These cases are discussed in the context of evidence that lithium may be useful in other patients with disorders of impulse control. The evidence linking disorders of anger and impulse control to a dysregulation in neurotransmitter regulation, particularly in serotonergic pathways, supports a psychopharmacologic approach to treatment. These findings should lead to further study of the role of lithium in the treatment of this symptom complex in patients with PTSD.  相似文献   
49.
There are conflicting reports on the relationship between cerebellar vermal lobule hypoplasia and autism. Using quantitative magnetic resonance image analysis, we measured the cerebellar vermis in 125 normal individuals with a broad age range and 102 patients with a variety of neurogenetic abnormalities. We conclude that hypoplasia of cerebellar vermal lobules VI and VII is a nonspecific finding that even occurs in several conditions without autistic behavior. This suggests that it is not a specific neuroanatomical marker for autism, nor is cerebellar dys- genesis likely to be solely responsible for clinical autistic behaviors.  相似文献   
50.
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