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   939571篇
  免费   67217篇
  国内免费   1444篇
耳鼻咽喉   13059篇
儿科学   24540篇
妇产科学   23405篇
基础医学   133819篇
口腔科学   28390篇
临床医学   81390篇
内科学   184982篇
皮肤病学   19322篇
神经病学   72681篇
特种医学   37088篇
外国民族医学   80篇
外科学   153358篇
综合类   18498篇
现状与发展   2篇
一般理论   240篇
预防医学   62247篇
眼科学   21431篇
药学   73144篇
  3篇
中国医学   2269篇
肿瘤学   58284篇
  2018年   9220篇
  2017年   7247篇
  2016年   7998篇
  2015年   9140篇
  2014年   12323篇
  2013年   17857篇
  2012年   24569篇
  2011年   25546篇
  2010年   15175篇
  2009年   14503篇
  2008年   24978篇
  2007年   26105篇
  2006年   26907篇
  2005年   25807篇
  2004年   24948篇
  2003年   23987篇
  2002年   23478篇
  2001年   54938篇
  2000年   56718篇
  1999年   47083篇
  1998年   10793篇
  1997年   9534篇
  1996年   9642篇
  1995年   8978篇
  1994年   8324篇
  1993年   7622篇
  1992年   35578篇
  1991年   34002篇
  1990年   32826篇
  1989年   31946篇
  1988年   29080篇
  1987年   28319篇
  1986年   26358篇
  1985年   25206篇
  1984年   17873篇
  1983年   15182篇
  1982年   7820篇
  1981年   6794篇
  1979年   15802篇
  1978年   10615篇
  1977年   9066篇
  1976年   7888篇
  1975年   8641篇
  1974年   10481篇
  1973年   9877篇
  1972年   9373篇
  1971年   8866篇
  1970年   8435篇
  1969年   7931篇
  1968年   7212篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
91.
92.
93.
94.
95.
To investigate the role of cell-mediated immunity (CMI) in glomerulonephritis (GN), we identified the infiltrating immune cells both within the glomerulus and in the interstitium. Frozen sections from 103 patients with various forms of GN: 10 with minor glomerular abnormality (MGA) as control, 10 with minimal change nephrotic syndrome (MCNS), 10 with membranous nephropathy (MN), 9 with focal glomerulosclerosis (FGS), 30 with IgA nephropathy (IgAN), 22 with acute post streptococcal glomerulonephritis (APSGN), and 2 with rapidly progressive glomerulonephritis (RPGN) were examined using monoclonal antibodies (MoAb) by indirect immunoalkaline-phosphatase labelling. In most glomerulonephritis, monocyte/M phi and helper/inducer T cells were predominantly infiltrating in the interstitium, but intraglomerular infiltration was rare, except for APSGN. This interstitial infiltration increased proportionally to the level of serum creatinine, and was most prominent in RPGN. Apparently different distribution was seen in APSGN, that is, prominent increase in total number of intra-glomerular monocyte/M phi infiltration with slightly increased T cells. The change was correlated with time after onset; namely the more leucocytic infiltration was observed when the tissue was taken earlier. These data suggest that in APSGN, monocyte/M phi accumulate in glomeruli via cell mediated immunity in addition to humoral immune mechanism resulting in glomerular hypercellularity, whereas in most chronic glomerulonephritis interstitial leucocyte infiltration, particularly helper T cells and monocyte/M phi may play an important role in the progression of glomerulonephritis.  相似文献   
96.
Free-floating clots of the extracranial internal carotid artery are generally considered as surgical emergencies. This retrospective study analyzes six free-floating clots diagnosed by arteriography. Three of these patients had a fixed stroke while the other three had an evolving stroke. Three patients had antecedent ocular or hemispheric transient ischemic attacks. The causes of free-floating clots in the internal carotid artery were atheromatous stenosis in two cases, ulcerated plaque in three cases, and carotid artery dissection in one. All six patients were seen late, approximately 15 hours after their neurologic accident. They were treated with intravenous heparin over a two to five week period. Repeat arteriograms demonstrated complete clot lysis in four instances, while partial lysis was seen in one case. Moderate extension of thrombus occurred in one case only. No further neurologic complications were noted during the treatment by heparin. As indicated by follow-up arteriographic findings, secondary surgery was performed for major carotid lesions and residual clots in five cases. The free-floating thrombus syndrome of the carotid artery should not be considered as a surgical emergency when discovered late in the wake of an acute neurologic accident.  相似文献   
97.
The amount of endothelial cell loss that occurs to the donor cornea during the trephination process was evaluated in 40 porcine eyes. A vital staining technique (alizarin red S and acid violet 19) was used to quantify the extent of endothelial damage and removal. Two types of corneal punches (Weck and H&I0 were used for trephination. The average amount of endothelial loss from the peripheral cornea was 7.9%, accounting for only a 3% loss of endothelial cells over the total surface area of the corneal button. a comparison of the Weck and H&I corneal punches showed no significant difference (P greater than 0.1) by Student's test for both endothelial cell damage and removal.  相似文献   
98.
Multicentricity of hepatocellular carcinoma (HCC) is considered, especially in patients with liver cirrhosis. This paper describes an operative case of a male patient with probable multicentric development of HCC in precirrhotic fibrosis. The main tumors inside the capsule were completely necrotic due to transarterial embolization (TAE). Histologic examination disclosed discrete tiny nodules of HCC that were not detected grossly. They showed highly differentiated trabecular arrangements: Edmondson I. A scirrhous type was noted in the center of the tumors. At the borders of the tumors the carcinoma cells exhibited replacing growth patterns and it was thought that they developed multicentrically. Partial resection must be performed as extensively as possible in a case such as the present one.  相似文献   
99.
100.
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