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   23321篇
  免费   1948篇
  国内免费   40篇
耳鼻咽喉   247篇
儿科学   605篇
妇产科学   572篇
基础医学   2899篇
口腔科学   448篇
临床医学   2727篇
内科学   4189篇
皮肤病学   235篇
神经病学   2386篇
特种医学   668篇
外科学   2975篇
综合类   656篇
一般理论   27篇
预防医学   2423篇
眼科学   560篇
药学   1838篇
中国医学   23篇
肿瘤学   1831篇
  2022年   160篇
  2021年   309篇
  2020年   225篇
  2019年   318篇
  2018年   416篇
  2017年   308篇
  2016年   375篇
  2015年   419篇
  2014年   543篇
  2013年   835篇
  2012年   1283篇
  2011年   1269篇
  2010年   692篇
  2009年   621篇
  2008年   1134篇
  2007年   1239篇
  2006年   1150篇
  2005年   1138篇
  2004年   1136篇
  2003年   1013篇
  2002年   1021篇
  2001年   641篇
  2000年   598篇
  1999年   549篇
  1998年   303篇
  1997年   235篇
  1996年   245篇
  1995年   230篇
  1994年   210篇
  1993年   211篇
  1992年   406篇
  1991年   399篇
  1990年   433篇
  1989年   385篇
  1988年   372篇
  1987年   364篇
  1986年   353篇
  1985年   310篇
  1984年   252篇
  1983年   203篇
  1982年   146篇
  1981年   129篇
  1979年   243篇
  1978年   162篇
  1977年   142篇
  1976年   124篇
  1975年   145篇
  1974年   168篇
  1973年   135篇
  1968年   117篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Vacuum-assisted closure (VAC), although a modern adjunct in wound management, has not been used previously in pyoderma gangrenosum (PG), probably to avoid the potential complications of ‘pathergy’. We would like to report our experience of VAC in three cases of PG with the relevant review of literature.  相似文献   
3.
Mucosal trypsin, a protease-activated receptor (PAR) stimulant, may have an endogenous bronchoprotective role on airway smooth muscle. To test this possibility the effects of lumenal trypsin on airway tone in segments of pig bronchus were tested. Bronchial segments from pigs were mounted in an organ chamber containing Kreb's solution. Contractions were assessed from isovolumetric lumen pressure induced by acetylcholine (ACh) or carbachol added to the adventitia. Trypsin, added to the airway lumen (300 microg x mL(-1)), had no immediate effect on smooth muscle tone but suppressed ACh-induced contractions after 60 min, for at least 3 h. Synthetic activating peptides (AP) for PAR1, PAR2 or PAR3 were without effect, but PAR4 AP caused rapid, weak suppression of contractions. Lumenal thrombin was without effect and did not prevent the effects of trypsin. Effects of trypsin were reduced by N(omega)-nitro-L-arginine methyl ester but not indomethacin. Trypsin, thrombin and PAR4 AP released prostaglandin E2. Adventitially, trypsin, thrombin and PAR4 AP (but not PAR2 AP) relaxed carbachol-toned airways after <3 min. The findings of this study show that trypsin causes delayed and persistent bronchoprotection by interacting with airway cells accessible from the lumen. The signalling mechanism may involve nitric oxide synthase but not prostanoids or protease-activated receptors.  相似文献   
4.
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   
5.
Choledochal cyst is an unusual but serious condition which most commonly affects Oriental people. Recent experience of three patients with this condition in whom diagnosis was made by ultrasound examination is reported. Cholangiography (ERCP or PTC) was performed in two of the cases to define the anatomy. All three cases were successfully managed by cyst excision and biliary reconstruction by Roux-en-Y hepaticojejunostomy. The rationale for and importance of cyst excision are discussed.  相似文献   
6.
7.
Depression continues to be a major cause of morbidity and mortality in the elderly. It is estimated that 1–5% of elderly persons who live in the community and 5–43% of nursing–home patients have major depression. Symptoms of depression in the elderly do not differ substantially from younger patients. Tricyclic antidepressants continue to be the drugs of choice in the elderly because of their long record of use with proven efficacy, known adverse effect profile and availability of less expensive generic formulations. The newer secondgeneration antidepressants, including serotonin reuptake inhibitors, appear to offer a major advantage of fewer serious adverse effects in the elderly. This review will highlight recent developments regarding the prevalence and treatment of depression in the elderly.  相似文献   
8.
The effect of psychosocial factors on lung cancer mortality at one year   总被引:1,自引:0,他引:1  
In this study newly diagnosed male and female lung cancer patients admitted to two Ontario Cancer Foundation treatment clinics were interviewed. Information was obtained on demographic variables, presence of other chronic illness and the following psychosocial attributes: locus of control, social support and personality traits. From the clinic charts, information on stage of disease and pathological diagnosis was obtained. After controlling for the effects of stage and pathological diagnosis, the following psychological variables were found to increase the odds of death from lung cancer among males and females combined at one year after diagnosis: a high need for one aspect of social support, a reserved personality and the extremes of the personality trait soberness vs enthusiasm.  相似文献   
9.
10.
The renin-angiotensin system has traditionally been associated with the regulation of fluid and electrolyte balance. In this review we summarize the data which ascribes a completely new function to this system, i.e., the regulation of alcohol consumption. In addition, we suggest a possible mechanism for this effect based on the concept of a satiety or stop process. The approach taken was to examine the effect on alcohol intake of a wide variety of drug, genetic, dietary, surgical and neurosurgical manipulations, each of which has a range of biological effects characteristic of that manipulation, but all of which share the common property of altering activity in the renin-angiotensin system. The effect of these manipulations on alcohol intake was most parsimoniously explained by reference to their ability to raise or lower activity in the renin-angiotensin system. Any intervention which modulates activity in this system, either directly or indirectly, is likely to have consequences for alcohol consumption.  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