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   373492篇
  免费   45500篇
  国内免费   3210篇
耳鼻咽喉   7242篇
儿科学   11072篇
妇产科学   6644篇
基础医学   32033篇
口腔科学   5712篇
临床医学   49012篇
内科学   93251篇
皮肤病学   10414篇
神经病学   37285篇
特种医学   15936篇
外国民族医学   13篇
外科学   75360篇
综合类   2750篇
现状与发展   73篇
一般理论   177篇
预防医学   23030篇
眼科学   8650篇
药学   16376篇
  1篇
中国医学   325篇
肿瘤学   26846篇
  2024年   588篇
  2023年   5697篇
  2022年   2953篇
  2021年   8137篇
  2020年   8643篇
  2019年   7002篇
  2018年   12929篇
  2017年   11269篇
  2016年   12655篇
  2015年   13526篇
  2014年   22837篇
  2013年   25818篇
  2012年   22249篇
  2011年   23016篇
  2010年   19714篇
  2009年   22594篇
  2008年   21203篇
  2007年   20321篇
  2006年   22205篇
  2005年   19480篇
  2004年   17799篇
  2003年   15570篇
  2002年   15079篇
  2001年   5504篇
  2000年   4252篇
  1999年   5038篇
  1998年   6211篇
  1997年   5489篇
  1996年   5083篇
  1995年   4793篇
  1994年   3356篇
  1993年   2968篇
  1992年   2286篇
  1991年   2259篇
  1990年   1798篇
  1989年   1868篇
  1988年   1647篇
  1987年   1426篇
  1986年   1485篇
  1985年   1359篇
  1984年   1428篇
  1983年   1280篇
  1982年   1524篇
  1981年   1351篇
  1980年   1182篇
  1979年   761篇
  1978年   841篇
  1977年   833篇
  1976年   638篇
  1975年   589篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
101.
102.
Adrenoceptor and calcium channel modulating medications are widely used in clinical practice for acute neurological and systemic conditions. It is generally assumed that the cerebrovascular effects of these drugs mirror that of their systemic effects – and this is reflected in how these medications are currently used in clinical practice. However, recent research suggests that there are distinct cerebrovascular-specific effects of these medications that are related to the unique characteristics of the cerebrovascular anatomy including the regional heterogeneity in density and distribution of adrenoceptor subtypes and calcium channels along the cerebrovasculature. In this review, we critically evaluate existing basic science and clinical research to discuss known and putative interactions between adrenoceptor and calcium channel modulating pharmacotherapies, the neurovascular unit, and cerebrovascular anatomy. In doing so, we provide a rationale for selecting vasoactive medications based on lesion location and lay a foundation for future investigations that will define neuroprotective paradigms of adrenoceptor and calcium channel modulating therapies to improve neurological outcomes in acute neurological and systemic disorders.  相似文献   
103.
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   
104.
ABSTRACT

Objectives: The present study investigated the relationships of enculturation and depressive symptoms with health risk behavior engagement in Mexican-American college students and examined how these relationships differed by gender. Previous research has noted consistent gender differences in health risk behavior (e.g. alcohol use, substance use, and risky sexual behavior) among Latina/os, and emphasized the role of U.S. acculturation in this difference. Research examining the role of heritage cultural retention (i.e. enculturation), and including the added influence of mental health variables, such as depressive symptoms, is currently lacking. This study sought to address this gap.

Design: A large sample (N?=?677) of Mexican-American college students from four universities (located in New York, California, Florida, and Texas) completed an online questionnaire assessing health risk behaviors and corresponding variables.

Results: We found that males who endorsed more behavioral enculturation and depressive symptoms were more likely to engage in health risk behavior than all others in the sample. Contrary to previous literature, no relationship was found between behavioral enculturation and health risk behavior in females.

Conclusion: The current study found behavioral enculturation to be associated with depressive symptoms, and in turn with health risk behaviors among the males in our sample. Additional research will be needed to identify the mechanism underlying the relationship between enculturation and depressive symptoms as well as between depressive symptoms and risky behavior.  相似文献   
105.
Abstract

Objective

Two similarly designed studies compared user experiences with a second-generation extra-thin-wall, 5-bevel 32?G?×?4?mm pen needle (PN) with redesigned hub versus four thinner commercially available PNs.  相似文献   
106.
107.
108.
109.
110.
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