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   933279篇
  免费   66426篇
  国内免费   1349篇
耳鼻咽喉   12968篇
儿科学   24381篇
妇产科学   23249篇
基础医学   133047篇
口腔科学   28287篇
临床医学   80631篇
内科学   183591篇
皮肤病学   19312篇
神经病学   72275篇
特种医学   36860篇
外国民族医学   79篇
外科学   152321篇
综合类   18056篇
现状与发展   1篇
一般理论   234篇
预防医学   61795篇
眼科学   21313篇
药学   72648篇
  3篇
中国医学   2167篇
肿瘤学   57836篇
  2018年   8993篇
  2017年   7068篇
  2016年   7799篇
  2015年   8899篇
  2014年   12022篇
  2013年   17541篇
  2012年   24160篇
  2011年   25135篇
  2010年   14863篇
  2009年   14310篇
  2008年   24659篇
  2007年   25777篇
  2006年   26557篇
  2005年   25502篇
  2004年   24637篇
  2003年   23685篇
  2002年   23224篇
  2001年   54767篇
  2000年   56570篇
  1999年   46974篇
  1998年   10749篇
  1997年   9470篇
  1996年   9601篇
  1995年   8941篇
  1994年   8287篇
  1993年   7603篇
  1992年   35503篇
  1991年   33925篇
  1990年   32746篇
  1989年   31878篇
  1988年   29009篇
  1987年   28258篇
  1986年   26297篇
  1985年   25156篇
  1984年   17845篇
  1983年   15153篇
  1982年   7801篇
  1981年   6773篇
  1979年   15786篇
  1978年   10599篇
  1977年   9062篇
  1976年   7876篇
  1975年   8637篇
  1974年   10467篇
  1973年   9865篇
  1972年   9365篇
  1971年   8857篇
  1970年   8434篇
  1969年   7935篇
  1968年   7205篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Patients on long-term haemodialysis suffer from dialysis arthropathy due to the deposition of dialysis amyloid. We investigated the use of 99Tc-labelled methylene diphosphonate bone scans in 17 patients as a possible in vivo diagnostic technique. In most clinically affected joints, with the exception of shoulders and hands, there was increased radioisotope uptake consistent with uptake by periarticular bone. In addition, we describe intense soft-tissue uptake around some clinically affected large joints. In contrast, control groups of patients on haemodialysis without arthropathy and patients without renal failure did not have increased uptake. A semi-quantitative scale of uptake was devised, and the following correlations were significant: pain perception and isotope uptake score in the ankles and feet, and the number of radiological lesions and isotope uptake scores in the wrists and knees. The following sites where the radioisotope might bind in the affected joints are proposed: amyloid deposits, areas of soft-tissue calcification, or areas of increased bone turnover. It is concluded that whereas the scanning technique cannot make a definite diagnosis of amyloid and, therefore, cannot be expected to supersede histological diagnosis, it is a useful adjuvant investigation, of particular importance in those patients unable or unwilling to undergo biopsy.  相似文献   
82.
Eleven patients with lunatomalacia were treated by excision of the lunate and instillation of liquid silicone. The silicone vulcanised and formed an in-situ molded prosthesis. The patients were reexamined after a mean of 7.1 years. Four patients were pain-free and two had pain only at work; three had not been improved by the operation and two had undergone arthrodesis. The patients with good results all belonged to group IV pre-operatively. Surprisingly, no patient showed any sign of silicone synovitis, although all the prostheses except one had either fractured or deformed. The reasons for this are discussed and the indications for the operation established.  相似文献   
83.
84.
Excision of the rectum should take in account that the main lymphatic spread follows the cranial route and that dissection of the rectal wall should be performed across its adjacent anatomical lamellae. It is not clear whether an extensive pelvic dissection and high ligature of the inferior mesenteric artery are beneficial. Spontaneous or iatrogenic perforation of the tumour considerable increases the incidence of local recurrence. The frequency of postoperative urinary and sexual dysfunction ranges from 3.5-57% and 14-38% respectively. The reported surgical mortality averages 5-6%.  相似文献   
85.
Summary A case of bilateral congenital pseudarthrosis of the clavicle in a baby boy is described. The patient is fully asymptomatic, and no functional impairment is present. This is probably only the seventh case described of this rare congenital anomaly.  相似文献   
86.
Regional effects of craniotomy on cerebral circulation and metabolism, such as regional cerebral blood flow (rCBF), regional cerebral oxygen consumption (rCMRO2), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) were examined by a PET (positron emission tomography) study concerning surgery that was performed on unruptured aneurysm patients. Eight patients with intracranial un-ruptured aneurysms were studied pre- and post-operatively by the 15O labelled-gas steady-state method, using HEADTOME-III. All patients underwent aneurysmal surgery performed by the transsylvian approach. There was a significant increase in the mean OEF values taken from the whole-brains of 8 patients, but there was not a significant change in CBF, CMRO2 or CBV. The increase in OEF was caused by decrease of O2 content, which was caused by post-operative decrease in the Hb value. So, this OEF increase was not the direct effect of craniotomy. In 2 patients, the rCBF and rCMRO2, in the fronto-temporal region (where craniotomy was performed) increased post-operatively. This regional effect suggests transient reactive hyperemia following compressive ischemia during the operative procedure, and metabolic demands for recovery of brain function. In 2 other patients, who had relatively low rCBFs during the pre-operative study, rCBF and rCMRO2 in the bi-frontal region had decreased more at the post-operative study. This change appears to have been caused by removal of cerebrospinal fluid and depression of the frontal lobe. From this study, it becomes evident that the regional effect of craniotomy on cerebral circulation and metabolism is not so great, when adequate microsurgical techniques are used.  相似文献   
87.
88.
89.
90.
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