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   174943篇
  免费   7000篇
  国内免费   320篇
耳鼻咽喉   3095篇
儿科学   6550篇
妇产科学   4572篇
基础医学   24726篇
口腔科学   4916篇
临床医学   13045篇
内科学   31788篇
皮肤病学   4938篇
神经病学   16150篇
特种医学   8829篇
外国民族医学   24篇
外科学   28742篇
综合类   1104篇
一般理论   39篇
预防医学   8394篇
眼科学   4732篇
药学   12188篇
中国医学   357篇
肿瘤学   8074篇
  2023年   786篇
  2021年   1259篇
  2020年   1137篇
  2019年   1326篇
  2018年   2944篇
  2017年   2451篇
  2016年   3387篇
  2015年   3733篇
  2014年   3910篇
  2013年   5546篇
  2012年   8575篇
  2011年   8000篇
  2010年   4704篇
  2009年   3766篇
  2008年   7915篇
  2007年   8769篇
  2006年   8789篇
  2005年   9207篇
  2004年   8785篇
  2003年   8628篇
  2002年   8553篇
  2001年   6397篇
  2000年   6473篇
  1999年   5568篇
  1998年   1618篇
  1997年   1332篇
  1996年   1010篇
  1995年   825篇
  1994年   769篇
  1992年   2476篇
  1991年   2382篇
  1990年   2359篇
  1989年   2186篇
  1988年   1929篇
  1987年   1893篇
  1986年   1762篇
  1985年   1687篇
  1984年   1321篇
  1983年   1065篇
  1979年   1420篇
  1978年   1044篇
  1977年   879篇
  1975年   1097篇
  1974年   1131篇
  1973年   1041篇
  1972年   1052篇
  1971年   1018篇
  1970年   903篇
  1969年   865篇
  1968年   832篇
排序方式: 共有10000条查询结果,搜索用时 95 毫秒
71.
Adamantinoma of long bones is one of the rarest of malignant bone tumors; it is commonly located in the middle or lower third of the diaphysis of the tibia. A case with multiple occurrences affecting both the tibia and fibula is presented. En bloc resection with wide operative margins was performed, and a large tibial defect of 23 cm was effectively bridged by a revascularized free fibular flap. At 13 months follow-up, there was no sign of local recurrence or metastasis, and the patient was mobile.  相似文献   
72.
73.
74.
Volume and profile of alcohol consumption among students and classmates as predictors of aggression and victimization: a multilevel analysis among Swiss adolescents

Objective:  

To test the effects of the volume of alcohol consumption and drinking patterns on alcohol-related aggression and victimization, both at the individual and class levels.  相似文献   
75.
Background Gastrointestinal stromal tumours (GISTs) are thought to arise from the interstitial cells of Cajal (ICCs). ICCs form a network surrounding the myenteric plexus and between-muscle fibres of the muscularis propria of the tubular GI tract. The cell of origin of so-called extra-gastrointestinal stromal tumours (EGISTs) is not known.Aim and methods To study the diversity of gross presentation of GISTs and to critically assess the incidence of EGISTs and their relationship to mural GISTs, a total of 200 neoplasms with typical morphologic and immunohistochemical features of GISTs were reviewed, looking for any degree of association with the muscularis propria of the gut wall.Results There were 130 gastric (65%), 9 duodenal (4.5%), 48 small intestinal (24%), 9 colorectal (4.5%), 1 appendiceal (0.5%) and 3 unclassifiable GISTs (1.5%). Fourteen cases (7%) were initially submitted as EGISTs (four mesenteric, four omental, one pararectal/prostatic, one pelvic/Douglas, one perivesical, one located between root of mesentery and tail of pancreas, one involving the mesentery, omentum and abdominal wall extensively and one located between liver and stomach). After critical re-evaluation of surgical reports and remote clinical history and a careful search for residual muscular tissue from the gut wall in the tumour pseudocapsule (in some cases supported by desmin immunoreactivity), it was possible to reclassify most of these cases (11/14) as either GISTs with extensive extramural growth resulting in loss of contact to the external muscle coat of the gut (8/14) or as metastases from an inoperable GIST (2/14) or from a previously resected deceptively benign tumour (1/14).Conclusion EGISTs are probably rarer than previously reported (1.5% or less in this study). We concluded that most so-called EGISTs represent apparent EGISTs that should have arisen from the outermost muscle coat, but have lost their contact to the point of origin due to extensive extramural growth pattern. From a surgical point of view, it is crucial to document and mark any focal attachment or adhesions to the gut wall noticed during surgery for an apparent EGIST. In contrast to most other neoplasms, GISTs should be defined by virtue of any degree of association with the muscularis propria (no matter how minimal), but not by localisation of the bulk of the tumour.  相似文献   
76.
Poor results after surgery for bronchioloalveolar carcinoma.   总被引:2,自引:0,他引:2  
BACKGROUND: Bronchioloalveolar carcinoma (BAC) is suggested to be less aggressive than other types of lung cancer. To assess the option of treatment modification, actual outcome data were studied and compared with results for other types of lung cancer. METHOD: Retrospective analysis of all consecutive patients who underwent resection for stage I lung cancer in our hospital. For 18 BAC cases, histological specimens were re-evaluated and in three cases diagnosis was revised. RESULTS: In the period 1989 through 2000, 15 patients with BAC and 260 patients with other tumour types underwent surgery in our hospital. Five-year survival rates were 24 and 53%, respectively, (p = 0.01). CONCLUSIONS: Given the poor results after standard surgery, parenchyma-sparing operations do not seem justified in patients with invasive BAC.  相似文献   
77.
Abstract Chorea is a rare complication of polycythaemia vera. Polycythaemic chorea occurs predominantly in females and usually in generalised form. We present a 66-year-old woman with acute onset hemichorea-ballism with no vascular pathology in the basal ganglia region. A clear relationship was observed between the onset of chorea and worsening of haematological parameters in the patient. After repeated phlebotomies the patient's clinical status was improved. Polycythaemic chorea must be considered, especially in the elderly, as early diagnosis leads to effective treatment and prevention of complications.  相似文献   
78.
Renal fibrosis and the origin of the renal fibroblast.   总被引:4,自引:0,他引:4  
Many studies have determined that the extent of tubulointerstitialinvolvement, particularly fibrosis, correlates better with renalfunction than glomerular changes do, thus, the extent of tubulointerstitialdamage in any given renal biopsy has important implicationsfor the renal prognosis of the patient (summarized in [1]).Tubulointerstitial fibrosis is characterized by the accumulationof extracellular matrix components including collagen typesI, III, IV, proteoglycans and fibronectin. In recent years,much controversy has been created in the nephrology communityregarding the origin of matrix-producing cells in the kidney.Several possibilities exist, including activation of residentinterstitial fibroblasts, migrating haematopoietic or mesenchymalstem cells from the bone marrow, periadventitial cells and epithelial–mesenchymaltransition (EMT) of tubular epithelial cells. This review summarizesrecent data indicating the possible origin of matrix-producingcells in the kidney, and illustrates from a clinical point of  相似文献   
79.
80.

Background  

Patient falls in hospitals are common and may lead to negative outcomes such as injuries, prolonged hospitalization and legal liability. Consequently, various hospital falls prevention programs have been implemented in the last decades. However, most of the programs had no sustained effects on falls reduction over extended periods of time.  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