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   978476篇
  免费   69317篇
  国内免费   1484篇
耳鼻咽喉   13534篇
儿科学   25701篇
妇产科学   24085篇
基础医学   138491篇
口腔科学   29038篇
临床医学   85483篇
内科学   193055篇
皮肤病学   20061篇
神经病学   76536篇
特种医学   38740篇
外国民族医学   80篇
外科学   160061篇
综合类   18503篇
现状与发展   1篇
一般理论   281篇
预防医学   64710篇
眼科学   22116篇
药学   75464篇
  3篇
中国医学   2199篇
肿瘤学   61135篇
  2018年   10149篇
  2017年   7894篇
  2016年   8667篇
  2015年   9925篇
  2014年   13615篇
  2013年   19628篇
  2012年   27501篇
  2011年   28614篇
  2010年   16807篇
  2009年   15980篇
  2008年   27729篇
  2007年   29022篇
  2006年   29786篇
  2005年   28646篇
  2004年   27633篇
  2003年   26493篇
  2002年   25794篇
  2001年   55126篇
  2000年   56828篇
  1999年   47363篇
  1998年   11275篇
  1997年   9922篇
  1996年   9934篇
  1995年   9268篇
  1994年   8599篇
  1993年   7865篇
  1992年   35729篇
  1991年   34147篇
  1990年   32943篇
  1989年   32052篇
  1988年   29189篇
  1987年   28432篇
  1986年   26454篇
  1985年   25314篇
  1984年   18024篇
  1983年   15327篇
  1982年   8010篇
  1981年   6958篇
  1979年   15893篇
  1978年   10687篇
  1977年   9127篇
  1976年   7931篇
  1975年   8672篇
  1974年   10526篇
  1973年   9907篇
  1972年   9388篇
  1971年   8880篇
  1970年   8453篇
  1969年   7939篇
  1968年   7214篇
排序方式: 共有10000条查询结果,搜索用时 15 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