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   1080693篇
  免费   80276篇
  国内免费   3327篇
耳鼻咽喉   13960篇
儿科学   37005篇
妇产科学   30541篇
基础医学   156326篇
口腔科学   29642篇
临床医学   97067篇
内科学   211602篇
皮肤病学   24601篇
神经病学   86756篇
特种医学   41694篇
外国民族医学   328篇
外科学   161281篇
综合类   25302篇
一般理论   427篇
预防医学   82631篇
眼科学   23932篇
药学   78675篇
  6篇
中国医学   2518篇
肿瘤学   60002篇
  2019年   8722篇
  2018年   12325篇
  2017年   9591篇
  2016年   10808篇
  2015年   12261篇
  2014年   16606篇
  2013年   25222篇
  2012年   33240篇
  2011年   35248篇
  2010年   21369篇
  2009年   19995篇
  2008年   32709篇
  2007年   34585篇
  2006年   34857篇
  2005年   33364篇
  2004年   32990篇
  2003年   31733篇
  2002年   30787篇
  2001年   50030篇
  2000年   51085篇
  1999年   42727篇
  1998年   12182篇
  1997年   10863篇
  1996年   10847篇
  1995年   10437篇
  1994年   9685篇
  1993年   9062篇
  1992年   33740篇
  1991年   32960篇
  1990年   32287篇
  1989年   31094篇
  1988年   28280篇
  1987年   28328篇
  1986年   26420篇
  1985年   25484篇
  1984年   19055篇
  1983年   16113篇
  1982年   9673篇
  1981年   8710篇
  1979年   17361篇
  1978年   12573篇
  1977年   10641篇
  1976年   10045篇
  1975年   10565篇
  1974年   12757篇
  1973年   12238篇
  1972年   11255篇
  1971年   10457篇
  1970年   9689篇
  1969年   9058篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
In 1986 and 1987, four patients with tibial malunion involving both angular and torsional misalignment underwent surgical correction by a single-cut technique based on a mathematical model of long bone deformity. The technique involved a single surgical cut, followed by rotation of the two fragments along the osteotomy plane. The orientation of the osteotomy is based on a computer-assisted design. The deformity is measured on radiographs, computed tomography, and clinical exam and is then plotted on graphs to find the osteotomy orientation. The deformity involved varus and extension in four cases, internal rotation in 2, and external rotation in two. The deformities ranged from 9 to 26 degrees. The cutting angle of the osteotomy ranged from 50 to 66 degrees as measured from the transverse plane. Actual lengthening of 1 cm and functional lengthening over 1.5 cm was obtained without the use of bone graft. As no wedge of bone was removed, all corrected bones were easily suited to rigid internal fixation across the cut surface. In all cases, the desired correction was obtained within measurable error, and union was obtained with minimal immobilization. There were no soft tissue or joint contractures, and no neurovascular complications. In one patient, who had had four prior surgical procedures on the involved limb, an infection developed 6 weeks postoperatively that required debridement and delayed primary closure. As the technique involves only one cut, no wedge of bone is removed, no shortening occurs, and the osteotomy is highly suitable for rigid internal fixation. The described technique is the first to integrate in a precise way the correction of torsion with the correction of angular deformity.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
992.
Two patients with angiolymphoid hyperplasia with eosinophilia isolated to the orbit had eyelid swelling, a superior orbital mass, and histories of intermittent obstructive airway disease. One patient later developed a transient peripheral blood eosinophilia as high as 36%. One lesion recurred 38 months postoperatively and responded to systemic corticosteroid therapy.  相似文献   
993.
alpha 1- and beta-adrenoceptors were studied ex vivo in the brains of rats receiving repeated daily treatment with the standard antidepressant imipramine or the atypical antidepressant S-adenosyl-L-methionine (SAM), which has minimal effects on monoamine reuptake or turnover. Consistent with past studies, a decrease in the density of beta receptors at three weeks and an increase in the affinity of alpha 1 receptors for the agonist phenylephrine at one week of treatment was observed with imipramine. By comparison, an increase in the density of beta receptors and a decrease in the affinity of alpha 1 receptors for phenylephrine was observed at one week of treatment with SAM. These changes were no longer apparent at three weeks of treatment. The results suggest that treatment with SAM does lead to changes in adrenergic neurotransmission, but that down regulation of beta receptors or increased agonist affinity of alpha 1 receptors may not be necessary for the production of antidepressant effects.  相似文献   
994.
A 50-year old Chinese woman with the rare neurological disorder of Choreoacanthocytosis is described. Her illness is characterised by seizures, buccolingual dyskinesia, choreiform movements, arreflexia and mild sensorimotor polyneuropathy. Acanthocytes were present in her peripheral blood in large numbers but the serum lipid profile was normal. Her features are consistent with those so far described in Caucasian and Japanese patients. The disease differs from Huntington's chorea in that there are acanthocytes, peripheral neuropathy, and metal function remains relatively intact.  相似文献   
995.
Schistosomiasis caused by Schistosoma mansoni has not been reported in Baringo District of Rift Valley Province. The intermediate host (Biomphalaria species) though has been reported to occur along the shores of the lakes in this region. Three children from Baringo District were diagnosed to have schistosomiasis caused by S. mansoni by finding ova in their stools. They gave no history of visiting an endemic area. There are many dams being built for land reclamation, creating favourable conditions for the spread of the disease, in presence of the intermediate and definitive host. Studies on the current status of the disease and malacology should be undertaken in order to control the spread of the disease at an early stage.  相似文献   
996.
Epidemiologic studies have shown that blood pressure increases more rapidly in middle-aged women than in middle-aged men. Whether or not ovarian failure contributes to this rapid rise is still not clear. In a follow-up study begun in 1979 and to continue for 10 years, the blood pressure of 193 healthy normotensive perimenopausal women, who lived in the mixed rural/industrial community of Ede, the Netherlands and who were initially aged between 49 and 56 years, was measured annually. During the course of the study, the onset of menopause of each participant could be established. Because of the mixed longitudinal design of the study, it was possible to evaluate the effects of both chronologic aging and time pre- or postmenopause on blood pressure. After the first seven years of follow-up, it was demonstrated that blood pressure did not increase in 168 women whose body weight was relatively stable. After multivariate analyses, systolic as well as diastolic pressure showed a significant negative relation (slope, 1.34 mmHg per year and 0.63 mmHg per year, respectively) with the years since menopause. On the other hand, the observed positive relation (slope, 0.81 mmHg per year) of systolic pressure with chronologic aging was not significant. No consistent association was found between diastolic pressure and chronologic aging. It is concluded that menopause cannot be regarded as a cause of hypertension; on the contrary, ovarian failure appears to have a protective effect on the increase in blood pressure as a result of chronologic aging. on the increase in blood pressure as a result of chronologic aging.  相似文献   
997.
998.
999.
1000.
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