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   1435282篇
  免费   109267篇
  国内免费   4443篇
耳鼻咽喉   17727篇
儿科学   46430篇
妇产科学   38550篇
基础医学   213782篇
口腔科学   38818篇
临床医学   138405篇
内科学   277863篇
皮肤病学   28275篇
神经病学   121876篇
特种医学   52363篇
外国民族医学   375篇
外科学   196485篇
综合类   29207篇
现状与发展   3篇
一般理论   558篇
预防医学   126454篇
眼科学   30619篇
药学   104906篇
  6篇
中国医学   3366篇
肿瘤学   82924篇
  2021年   12521篇
  2019年   13336篇
  2018年   18393篇
  2017年   14034篇
  2016年   15187篇
  2015年   17399篇
  2014年   23849篇
  2013年   36028篇
  2012年   50369篇
  2011年   53109篇
  2010年   30397篇
  2009年   28412篇
  2008年   48233篇
  2007年   50745篇
  2006年   50661篇
  2005年   48784篇
  2004年   46010篇
  2003年   43658篇
  2002年   42094篇
  2001年   64155篇
  2000年   65745篇
  1999年   55267篇
  1998年   15883篇
  1997年   14314篇
  1996年   14234篇
  1995年   13381篇
  1994年   12443篇
  1993年   11684篇
  1992年   43600篇
  1991年   42603篇
  1990年   41224篇
  1989年   38989篇
  1988年   36103篇
  1987年   35072篇
  1986年   33441篇
  1985年   31884篇
  1984年   23913篇
  1983年   20381篇
  1982年   12157篇
  1981年   10666篇
  1979年   21505篇
  1978年   15246篇
  1977年   12408篇
  1976年   12147篇
  1975年   12406篇
  1974年   15134篇
  1973年   14811篇
  1972年   13662篇
  1971年   12725篇
  1970年   11726篇
排序方式: 共有10000条查询结果,搜索用时 248 毫秒
991.
992.
Cancer risk after evaluation for infertility   总被引:3,自引:0,他引:3  
To evaluate cancer risk by various causes of infertility, the authors conducted a retrospective cohort study among 2,335 women evaluated for infertility at the Mayo Clinic between 1935 and 1964. Most cancers occurred at expected frequencies, with the exception of cancers of the thyroid (standardized incidence ratio (SIR) = 2.6) and other endocrine glands (SIR = 6.7), although analyses were based on small numbers. Patients with progesterone deficiencies (31 per cent of the study subjects) had a 20 per cent higher cancer risk than did those with other causes of infertility, with excesses deriving primarily from cancers of the lung, cervix, ovary, and thyroid and from melanoma. Breast cancer risk, however, was not elevated in either patients with progesterone deficiencies (SIR = 0.9) or patients with other causes of infertility (SIR = 1.0). Examination of other parameters of infertility, including age at evaluation, type of infertility (primary vs. secondary), and years of attempted conception, showed no elevated risks of breast cancer in any subgroup. These results fail to support previous studies that have linked progesterone deficiencies among infertile women to elevated breast cancer risk. However, the data suggest a possible involvement of a progesterone deficiency in the etiology of other cancers, particularly thyroid cancer and melanoma.  相似文献   
993.
994.
995.
A general overview of the literature concerning the development of diabetic neuropathic arthropathy is discussed. A case report is presented dealing with spontaneous fractures of the lesser metatarsal in a patient with an amputated hallux and peripheral neuropathy secondary to diabetes mellitus.  相似文献   
996.
997.
The anti-granulocyte activity of serum from patients with B-cell chronic lymphocytic leukaemia (CLL) and other lymphoproliferative disorders was investigated. Granulocyte-binding IgG was measured in 34 patients with CLL, 13 patients with hairy cell leukaemia, one patient with prolymphocytic leukaemia, two patients with Sézary cell leukaemia, and seven patients with chronic T-cell lymphocytosis who had a predominance of circulating large granular lymphocytes. Anti-granulocyte activity was absent in CLL and its variants, but present in the majority of granulocytopenic patients with chronic T-cell lymphocytosis. In one of these patients, granulocytopenia was associated with complement-activating IgG granulocyte antibody. Thus, antibody-mediated granulocyte injury appears to be an unusual occurrence in chronic lymphocytic leukaemia, but is a frequent complication of chronic T-cell lymphocytosis.  相似文献   
998.
Circulating immune complexes (CIC), adult schistosome antibody, and total immunoglobulin concentrations were estimated in sera from 35 chronic Schistosoma mansoni patients with different infection intensities and different pathological complications. High CIC levels were present in about one-third (10/35) of the sera. Most of the patients (9/10) with elevated CIC levels also had hepatomegaly or hepatosplenomegaly. This finding is significant in the pathogenesis of schistosomal liver fibrosis and may also apply to other liver diseases, especially cirrhosis. No correlation was found between infection intensity as judged by stool egg counts and CIC levels. A reverse relationship was observed between the level of anti-adult worm IgG and CIC levels. CIC levels were elevated within 7 and 28 days after treatment in most patients. Hypergammaglobulinaemia was detected in most sera.  相似文献   
999.
One hundred and one children over 1 year of age have had surgery for pelviureteric obstruction over an 11 year period. The common clinical features were abdominal pain, urinary infection or haematuria, but number presented as an incidental finding. Less commonly, the patients presented with an abdominal mass or with hypertension. The diagnosis was usually made on intravenous pyelography (IVP) but in the latter part of the series, renal nuclide scan (RNS) and ultrasonography (US) were preferred. Ninety–three patients had unilateral pyeloplasty, three had bilateral pyeloplasty and five had nephrectomy or heminephrectomy. Whereas initially nephrostomy drainage was used in the majority of patients after pyeloplasty, trend away from nephrostomy evolved in the latter part of the series. With experience, the incidence of postoperative complications was also reduced and there was reduction in the period of hospitalization. Clinical results were consistently satisfactory. Postoperative assessment after pyeloplasty was made by IVP and/or RNS and also US. A review of these investigations showed that RNS provided more factual information of the result when compared with the IVP.  相似文献   
1000.
Essential tremor     
Essential tremor is a common disorder whose aetiology is unknown. Characteristically it is present on maintaining posture, absent at rest, and not made significantly worse with movement.  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