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   40727篇
  免费   3376篇
  国内免费   112篇
耳鼻咽喉   706篇
儿科学   1134篇
妇产科学   693篇
基础医学   5353篇
口腔科学   817篇
临床医学   4081篇
内科学   8204篇
皮肤病学   747篇
神经病学   3326篇
特种医学   1363篇
外科学   6075篇
综合类   744篇
现状与发展   1篇
一般理论   44篇
预防医学   4093篇
眼科学   1151篇
药学   2630篇
中国医学   39篇
肿瘤学   3014篇
  2022年   317篇
  2021年   724篇
  2020年   435篇
  2019年   654篇
  2018年   845篇
  2017年   598篇
  2016年   706篇
  2015年   774篇
  2014年   1125篇
  2013年   1628篇
  2012年   2351篇
  2011年   2409篇
  2010年   1312篇
  2009年   1220篇
  2008年   2063篇
  2007年   2280篇
  2006年   2191篇
  2005年   2183篇
  2004年   2101篇
  2003年   1934篇
  2002年   1731篇
  2001年   918篇
  2000年   899篇
  1999年   845篇
  1998年   492篇
  1997年   400篇
  1996年   376篇
  1995年   350篇
  1994年   345篇
  1993年   303篇
  1992年   674篇
  1991年   591篇
  1990年   536篇
  1989年   573篇
  1988年   497篇
  1987年   488篇
  1986年   463篇
  1985年   455篇
  1984年   405篇
  1983年   317篇
  1982年   279篇
  1981年   306篇
  1980年   227篇
  1979年   350篇
  1978年   310篇
  1977年   237篇
  1975年   222篇
  1974年   283篇
  1973年   215篇
  1972年   231篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
ABSTRACT

Abortion is legal in South Africa, but negative abortion attitudes remain common and are poorly understood. We used nationally representative South African Social Attitudes Survey data to analyze abortion attitudes in the case of fetal anomaly and in the case of poverty from 2007 to 2016 (n = 20,711; ages = 16+). We measured correlations between abortion attitudes and these important predictors: religiosity, attitudes about premarital sex, attitudes about preferential hiring and promotion of women, and attitudes toward family gender roles. Abortion acceptability for poverty increased over time (b = 0.05, p < .001), but not for fetal anomaly (b = ?0.008, p = .284). Highly religious South Africans reported lower abortion acceptability in both cases (Odds Ratio (OR)anomaly = 0.85, p = .015; ORpoverty = 0.84, p = .02). Premarital sex acceptability strongly and positively predicted abortion acceptability (ORanomaly = 2.63, p < .001; ORpoverty = 2.46, p < .001). Attitudes about preferential hiring and promotion of women were not associated with abortion attitudes, but favorable attitudes about working mothers were positively associated with abortion acceptability for fetal anomaly ((ORanomaly = 1.09, p = .01; ORpoverty = 1.02, p = .641)). Results suggest negative abortion attitudes remain common in South Africa and are closely tied to religiosity, traditional ideologies about sexuality, and gender role expectations about motherhood.  相似文献   
4.
Theory: Immersive simulation is a common mode of education for medical students. Observation of clinical simulations prior to participation is believed to be beneficial, though this is often a passive process. Active observation may be more beneficial. Hypotheses: The hypothesis tested in this study was that the active use of a simple checklist during observation of an immersive simulation would result in better participant performance in a subsequent scenario compared with passive observation alone. Methods: Medical students were randomized to either passive or active (with checklist) observation of an immersive simulation involving cardiac arrest prior to participating in their own simulation. Performance measures included time to cardiopulmonary resuscitation (CPR) and time to defibrillation and were compared between first and second scenarios as well as between passive and active observers. Results: Seventy-nine simulations involving 232 students were conducted. Mean time to CPR was 18 seconds (SD = 11.6) for those using the checklist and 24 seconds (SD = 15.8) for those who observed passively (M difference = 6 seconds), t(35) = 1.46, p =.153. Time to defibrillation was 94 seconds (SD = 26.4) for those using the checklist and 92 seconds (SD = 23.8) for those who observed passively (M difference = –2 seconds), t(38) =.21, p =.837. Time to CPR was 24 seconds (SD = 15.8) for passive observers and 31 seconds (SD = 21.0; M difference = 7 seconds), t(35) = 1.13, p =.265, for their first scenario counterparts. Time to CPR was 18 seconds (SD = 11.6) for active observers and 36 seconds (SD = 26.2; M difference = 18 seconds), t(24) = 2.81, p =.010, for their first scenario counterparts. Time to defibrillation was 92 seconds (SD = 23.8) for passive observers and 125 seconds (SD = 32.2; M difference = 33 seconds), t(33) = 3.63, p =.001, for their first scenario counterparts. Time to defibrillation was 94 seconds (SD = 26.4) for the active observers and 132 seconds (SD = 52.9; M difference = 38 seconds), t(28) =.46, p =.008, for their first scenario counterparts. Conclusions: Observation alone leads to improved performance in the management of a simulated cardiac arrest. The active use of a simple skills-based checklist during observation did not appear to improve performance over passive observation alone.  相似文献   
5.
6.
7.
8.
We report on 4 children who experienced a syncopal episode while being treated with guanfacine without any other evident cause. Syncope appears to be an uncommon side effect of guanfacine and is probably due to drug-induced hypotension or bradycardia.  相似文献   
9.
To produce a stable epidermis, keratinocytes need to be firmly attached to the basement membrane. However, following wounding, keratinocytes are required to develop a migratory phenotype in order to reepithelialize the wound. To investigate some of the issues underlying reepithelialization, we have developed a three-dimensional in vitro model of tissue-engineered skin, comprising sterilized human dermis seeded with human keratinocytes and dermal fibroblasts. Using this model, we have shown that the inclusion of fibroblasts within the model increases the stability of keratinocyte attachment. We have also demonstrated that keratinocyte migration occurs most effectively in the absence of a basement membrane and following the inclusion of fibroblasts in the model. In addition, subjecting the keratinocyte layer to mechanical trauma induces a migratory phenotype. We conclude that this three-dimensional in vitro wound model can be used to increase our understanding of the factors that enhance keratinocyte migration and hence wound healing in vivo.  相似文献   
10.
Beliefs regarding the toleration of frustration and discomfort are often described as underlying psychological disturbance, and represent a fundamental concept in Rational Emotive Behavior Therapy (REBT). Nevertheless, there has been little systematic analysis of the content of these beliefs, which are often treated as a unidimensional construct. This paper investigates the relationship between a multidimensional Frustration Discomfort Scale (FDS) and measures of depressed mood, anxiety, and anger, in a clinical population. Results indicated that FDS sub-scales were differentially related to specific emotions, independent of self-esteem and negative affect. The entitlement sub-scale was uniquely associated with anger, discomfort intolerance with depressed mood, and emotional intolerance with anxiety. These results supported the validity of the FDS, the importance of distinguishing between frustration intolerance dimensions, and of separating these beliefs from those related to self-worth.Copies of the Frustration Discomfort Scale are available from the author on request  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