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   159115篇
  免费   10836篇
  国内免费   730篇
耳鼻咽喉   1769篇
儿科学   3932篇
妇产科学   2620篇
基础医学   20976篇
口腔科学   3421篇
临床医学   15653篇
内科学   33719篇
皮肤病学   3247篇
神经病学   14614篇
特种医学   7031篇
外国民族医学   14篇
外科学   25243篇
综合类   1994篇
一般理论   109篇
预防医学   11817篇
眼科学   3311篇
药学   10183篇
中国医学   239篇
肿瘤学   10789篇
  2023年   885篇
  2022年   1485篇
  2021年   3378篇
  2020年   2081篇
  2019年   3121篇
  2018年   3595篇
  2017年   2805篇
  2016年   3143篇
  2015年   3595篇
  2014年   5096篇
  2013年   6863篇
  2012年   10341篇
  2011年   11014篇
  2010年   6324篇
  2009年   6030篇
  2008年   9748篇
  2007年   10245篇
  2006年   10105篇
  2005年   10165篇
  2004年   9319篇
  2003年   8626篇
  2002年   8279篇
  2001年   2154篇
  2000年   1851篇
  1999年   2132篇
  1998年   1969篇
  1997年   1586篇
  1996年   1370篇
  1995年   1268篇
  1994年   1147篇
  1993年   1029篇
  1992年   1301篇
  1991年   1192篇
  1990年   1042篇
  1989年   985篇
  1988年   925篇
  1987年   896篇
  1986年   895篇
  1985年   870篇
  1984年   927篇
  1983年   796篇
  1982年   963篇
  1981年   864篇
  1980年   730篇
  1979年   655篇
  1978年   647篇
  1977年   537篇
  1976年   520篇
  1974年   512篇
  1973年   449篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Summary The authors report 165 cases of thoraco-lumbar lesions with neurological dysfunction. All the patient were operated. They analyze the neurological and mechanical results and indicate the use of different osteosynthesis apparatus according to the type and level of lesions.Harrington's rods seem to give more precise repositioning while Roy Camille's plates give more stability. When the posterior wall of the spinal canal is intact, Kempf's compression rods can be used.Thoraxic spine injuries seem to be an indication for Harrington's rods, while lumbar injuries seem to call for Camille's plates.  相似文献   
32.
33.
Mechanics and function in heart morphogenesis.   总被引:4,自引:0,他引:4  
For years, biomechanical engineers have studied the physical forces involved in morphogenesis of the heart. In a parallel stream of research, molecular and developmental biologists have sought to identify the molecular pathways responsible for embryonic heart development. Recently, several studies have shown that these two avenues of research should be integrated to explain how genes expressed in the heart regulate early heart function and affect physical morphogenetic steps, as well as to conversely show how early heart function affects the expression of genes required for morphogenesis. This review combines the perspectives of biomechanical engineering and developmental biology to lay out an integrated view of the role of mechanical forces in heart development.  相似文献   
34.
Follicular fluids from eight patients with one ovary and from ten patients with two ovaries were investigated for bioactive inhibin, total renin, oestradiol (E2) and progesterone (P4) concentrations. Four follicular fluids were pooled per patient before assessment. All women had been stimulated similarly using a protocol including a GnRH agonist, HMG and HCG. Renin levels were significantly lower and P4 significantly higher in pools of follicular fluid from patients with one ovary, whereas inhibin and E2 concentrations were similar in both patient groups. A significant negative correlation was found in the pools of follicular fluid between inhibin and E2 in both groups. These results suggest a role for inhibin and renin in the paracrine and autocrine control of stimulated follicular development.  相似文献   
35.
A study of intravenous (i.v.) cannula usage for medical emergencies admitted to hospitals in the Newham Health District was undertaken during two defined periods (24 and 35 days). Almost half the cannulas inserted (47%) were not flushed following an initial bolus injection of heparinized saline. The duration that cannulas remained in a vein ranged from 24 hours to 8 days (median 2 days) and inflammation around the cannula site was related to the length of time since insertion but unrelated to whether the cannula was flushed regularly or to the type of fluid used. Our findings indicate a substantial wastage of i.v. cannulas due to difficulties with insertion and suggest that isotonic saline, without heparin, is effective in maintaining cannula patency for 48 hours. It is concluded that these findings are not unique to the Newham Health District and worthwhile financial savings should be achieved throughout the NHS if clinicians reconsider the indications and use of i.v. cannulas for their patients.  相似文献   
36.
37.
Hirschsprung's disease in young adults   总被引:3,自引:0,他引:3  
Hirschsprung's disease is rarely seen in the young adult, and presents unique problems in management because of the massive dilatation and hypertrophy that occur proximal to the aganglionic rectum or the rectosigmoid colon. The diagnosis, which may be suspected by barium enema, is confirmed by suction or full-thickness biopsy of the rectum that may be complemented by anal manometry. Based on our experience with eight patients, a two-stage surgical reconstruction is recommended, with a preliminary sigmoid colostomy through the normally innervated colon and an associated defunctionalized stoma constituting the initial operation. The distal colonic stoma permits cleansing of the caudal colon while the normally innervated proximal colon reverts to near normal caliber, usually within 2 to 6 months. This approach is in accord with the recommendation of Fairgrieve. Reconstruction using a Duhamel or Soave procedure has given good results. The Duhamel procedure seems preferable when a considerable discrepancy remains between the ganglionic and aganglionic segments of rectum.  相似文献   
38.
39.
Encephalo-myelo-radiculo-ganglionitis presenting as pandysautonomia   总被引:2,自引:0,他引:2  
A 68-year-old man developed pandysautonomia with severe orthostatic dysfunction, fixed heart rate, low serum levels of norepinephrine and epinephrine, absent sympathetic skin responses, and pupillary abnormalities. CSF protein was 92 mg/dl. In spite of a good recovery following corticosteroid administration, a relapse occurred, with accompanying sensory symptoms confined to both arms. Fatal sudden cardiac arrest occurred after 4 months. Autopsy revealed numerous lymphocytic infiltrates, predominantly in autonomic and sensory ganglia and, to a lesser extent, in the nerve roots, spinal cord, and brainstem without evidence for an underlying tumor. This case provides histopathologic evidence for an inflammatory etiology of panautonomic neuropathy in some patients.  相似文献   
40.
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