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   152078篇
  免费   31347篇
  国内免费   2418篇
耳鼻咽喉   5204篇
儿科学   5387篇
妇产科学   2442篇
基础医学   3362篇
口腔科学   1505篇
临床医学   26755篇
内科学   47548篇
皮肤病学   7451篇
神经病学   14855篇
特种医学   6499篇
外科学   41097篇
综合类   330篇
现状与发展   72篇
一般理论   2篇
预防医学   7068篇
眼科学   3337篇
药学   1148篇
中国医学   14篇
肿瘤学   11767篇
  2024年   684篇
  2023年   4795篇
  2022年   1224篇
  2021年   3136篇
  2020年   6039篇
  2019年   2176篇
  2018年   7408篇
  2017年   7353篇
  2016年   8429篇
  2015年   8425篇
  2014年   15516篇
  2013年   15674篇
  2012年   5577篇
  2011年   5598篇
  2010年   10414篇
  2009年   14271篇
  2008年   5853篇
  2007年   4085篇
  2006年   6559篇
  2005年   3801篇
  2004年   3087篇
  2003年   2049篇
  2002年   2127篇
  2001年   3804篇
  2000年   3026篇
  1999年   3225篇
  1998年   3649篇
  1997年   3473篇
  1996年   3372篇
  1995年   3219篇
  1994年   1941篇
  1993年   1565篇
  1992年   1392篇
  1991年   1421篇
  1990年   1065篇
  1989年   1187篇
  1988年   1023篇
  1987年   863篇
  1986年   895篇
  1985年   737篇
  1984年   556篇
  1983年   535篇
  1982年   522篇
  1981年   408篇
  1980年   371篇
  1979年   312篇
  1978年   337篇
  1977年   402篇
  1975年   289篇
  1972年   309篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
CONTEXT: The physician assistant profession has been moving toward requiring master's degrees for new practitioners, but some argue this could change the face of the discipline. PURPOSE: To see if there is an association between physician assistants' academic degrees and practice in primary care, in rural areas, and with the medically underserved. METHODS: Surveys were sent to 880 graduates of the first 32 University of Washington physician assistant classes through 2000. Respondents noted their academic degree at program entry and the highest degree attained at any time up to the time of survey. Relationships between practice characteristics and academic degree levels were tested by unadjusted odds ratios and logistic regression after controlling for year of graduation and sex. RESULTS: Of the 478 respondents, 54% worked in primary care, about 30% practiced in nonmetropolitan communities, and 42% reported providing care for the medically underserved. Respondents with no degree (33% of total at entry, 24% at survey) were significantly more likely than degree holders to work in primary care and nonmetropolitan areas. Respondents with no degree at program entry were significantly more likely, and those with no degree at the time of the survey were marginally more likely, to self-report work with the medically underserved. CONCLUSION: Respondents with no academic degree are significantly more likely to demonstrate a commitment to primary, rural, and underserved health care. These findings may inform the national debate about the impact of required advanced degrees on the practice patterns of nonphysician providers.  相似文献   
13.
14.
15.
16.
The prevalence of heavy alcohol consumption is a major problem of increasing proportions throughout the world. Although alcohol sensitizing drugs and more recently serotonin uptake inhibitors are drug interventions with some following, their long term beneficial consequences have yet to be demonstrated. In recent years, we have demonstrated that manipulating activity in the renin-angiotensin system will dramatically alter voluntary alcohol consumption in rats. Based on these findings, the present study evaluated the ability of a class of drugs known as the angiotensin converting enzyme inhibitors to reduce voluntary alcohol drinking in laboratory animals. These drugs prevent the conversion of angiotensin I to angiotensin II. They have been licensed for use in Europe and North America and are indicated in the treatment of hypertension. Our experiments showed that both captopril (Capoten, Squibb) and enalapril (Vasotec, Merck Sharpe & Dohme) can reduce alcohol drinking in both normotensive and hypertensive animals regardless of whether the pattern of intake is in a bout or of a less exaggerated nature. Furthermore, this change in alcohol intake can occur without concomitant changes in blood pressure, plasma renin activity, overall fluid balance, or the distribution and metabolism of alcohol. Taken together these findings suggest that the angiotensin converting enzyme inhibitors should be evaluated in a clinical setting for they may prove to be a useful new treatment or treatment adjunct for alcohol abuse in humans.  相似文献   
17.
Concanavalin A-induced lymphocyte proliferation was studied in 25 patients with alcoholic hepatitis or compensated alcoholic cirrhosis. Nine alcoholics without evidence of liver disease were also evaluated. A nonlinear correlation equation, which was natural logarithmic, was applied to individual dose-response proliferation curves and permitted comparisons between patient groups and controls. The proliferative response in all patient groups was significantly lower when compared to healthy controls and was independent of the presence or absence of liver disease. This suggests that some changes in immune function observed in alcoholics may be linked to the direct effects of alcohol on the immune system rather than to the associated liver disease.  相似文献   
18.
EDITORIAL COMMENT: We accepted this case for publication to remind readers that although uterine rupture during labour in a primigravida is extremely uncommon it does occur, or at any rate nulliparas can develop abdominal pain and shock in labour with a haemoperitoneum resulting from a tear in a vein in the lower posterior uterine wall. When one sees the hugely dilated uterine and ovarian venous plexuses at Caesarean section it is easy to believe that bleeding from such a vessel during labour could be prodigious. This case suggests that a dilated vein with blood flow derangements may be the cause. Nonetheless, as the authors warn us, the necessary response is not a precise diagnosis, but rapid laparotomy. See also Editorial Comment to Chin MMS, Harvey JA, Duffy BL. Uterine rupture during labour in a primigravida. Aust NZ J Obstet Gynaecol 1996; 36: 210.  相似文献   
19.
20.
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