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   1733篇
  免费   84篇
  国内免费   58篇
耳鼻咽喉   5篇
儿科学   73篇
妇产科学   22篇
基础医学   182篇
口腔科学   53篇
临床医学   203篇
内科学   459篇
皮肤病学   51篇
神经病学   114篇
特种医学   338篇
外科学   114篇
综合类   26篇
一般理论   1篇
预防医学   52篇
眼科学   10篇
药学   88篇
中国医学   3篇
肿瘤学   81篇
  2023年   5篇
  2022年   8篇
  2021年   17篇
  2020年   14篇
  2019年   17篇
  2018年   30篇
  2017年   15篇
  2016年   20篇
  2015年   28篇
  2014年   34篇
  2013年   71篇
  2012年   61篇
  2011年   50篇
  2010年   50篇
  2009年   71篇
  2008年   45篇
  2007年   77篇
  2006年   54篇
  2005年   49篇
  2004年   38篇
  2003年   37篇
  2002年   24篇
  2001年   33篇
  2000年   28篇
  1999年   43篇
  1998年   77篇
  1997年   87篇
  1996年   108篇
  1995年   66篇
  1994年   64篇
  1993年   54篇
  1992年   29篇
  1991年   29篇
  1990年   34篇
  1989年   56篇
  1988年   55篇
  1987年   46篇
  1986年   50篇
  1985年   46篇
  1984年   12篇
  1983年   15篇
  1982年   15篇
  1981年   12篇
  1980年   11篇
  1979年   10篇
  1978年   16篇
  1977年   10篇
  1976年   16篇
  1975年   15篇
  1968年   5篇
排序方式: 共有1875条查询结果,搜索用时 31 毫秒
991.
992.
The aim of our research was to study if cholesterol feeding might affect the ischemic changes in the vessels surrounding infarction foci in Sephadex G-75-induced cerebral ischemia model (SG-75). One hundred-twenty-four rabbits were divided as follows: group I was given standard food for 5 weeks; group II: as group I and then injected with SG-75; group III: standard food plus 1% cholesterol for 5 weeks; and group IV: as group III and then injected with SG-75. Rabbits were sacrificed 3 h, 6 h and 2, 5 and 7 days after ischemia had occurred. Vessels surrounding infarction foci (SIF) were identified by using a 6% carbon perfusion. Samples were examined by light microscopy and transmission electron microscopy (TEM). The occurrence of hemorrhagic infarction (HI) showed a clear time/course increase in group II whereas a decrease after 2 days in group IV was observed. The rate of HI was 40% and 20% in group II and IV, respectively. SIF vessels showed red blood cells leakage in group II, whereas multiple platelet thrombi appeared in group IV. This phenomenon caused a more extensive ischemic damage, when compared to group II. By making use of a widely employed model of high cholesterol diet and of a more physiological model of cerebral ischemia devised by us, we have provided the evidence that the hypercholesterolemia-induced changes in the SIF vessels strongly affect the pattern and progression of cerebral ischemia.  相似文献   
993.
Outpatient percutaneous nephrostomy   总被引:1,自引:0,他引:1  
  相似文献   
994.
995.
996.
Primary open-angle glaucoma (POAG) is a highly prevalent cause of irreversible blindness which associates cupping of the optic disc and alteration of the visual field, elevation of intraocular pressure being a major risk factor. Provided diagnosis is made at an early stage, treatments are available to prevent visual impairment. A locus, GLC1A, has been mapped on chromosome 1q23-q25 in several families affected with juvenile-onset POAG (JOAG) and also in some families affected with juvenile and middle-age onset POAG. Recently, three mutations of the TIGR (Trabecular meshwork-Induced Glucocorticoid Response) gene were shown to be responsible for the disease in several American families and in unrelated POAG patients. We now describe five new mutations in eight French families. All mutations known to date appear to concentrate in the evolutionarily conserved C-terminal domain of TIGR which bears homology to frog olfactomedin, an extracellular matrix glycoprotein of the olfactory epithelium, to rat and human neuronal olfactomedin-related proteins and to F11C3.2, a protein from Caenorhabditis elegans . Moreover, this conserved domain of TIGR is encoded by a single exon to which mutation screening could be limited. Surprisingly, the TIGR message, which is abundantly transcribed in the trabecular meshwork and also in the ciliary body and the sclera, is not expressed in the optic nerve whose degeneration is, however, the primary lesion of POAG.   相似文献   
997.
998.
A nine year retrospective survey was carried out at the National Cancer Center Hospital in order to define the diagnostic clues and most suitable diagnostic assessment in resectable pancreatic cancer patients. Forty six cases were detected (27 pancreatic head cancers, 19 pancreatic body and tail cancers). There were 8, 26, 3 and 9 cases of t1, t2, t3 and t4 tumour size cancers, respectively. Abdominal pain and/or discomfort and back pain were the most common initial symptoms and chief complaints. Jaundice was present only in pancreatic head cancer cases. Abnormal GTT and CA 19-9 were the biochemical tests most commonly found abnormal, irrespective of tumour size. ERCP followed by US and CT were the most accurate technical tests. The best care toward the awareness of the initial symptoms needs to be followed, as a first choice, by a proper biochemical (CA 19-9, GTT) and technical (US, ERCP, CT) assessment in the hope of identifying those patients whose prognosis might be improved by an early operation.  相似文献   
999.
1000.
Tong  AW; Lee  JC; Stone  MJ 《Blood》1987,69(1):238-245
A myeloma cell-reactive monoclonal antibody (MoAb), MM4, was generated from BALB/c mice immunized with alternate injections of cells from two human multiple myeloma (MM) cell lines. Screening by the enzyme-linked immunosorbent assay (ELISA) technique showed that MM4 reacted with human MM cell lines (7 of 7 positive), as well as bone marrow aspirates from MM patients (4 of 4 cases positive). MM4 did not react with marrow aspirates from control patients (3 cases), or with peripheral blood mononuclear (PBM) cells from normal subjects, lymphocytic (12 cases) and myelogenous (8 cases) leukemia patients. In addition, MM4 was negative with polymorphonuclear leukocytes and RBCs from normal donors. By means of the immunoperoxidase technique, the MM4-reactive antigen was detected in paraffin-embedded, Zenker formalin-fixed bone marrow biopsies of MM (12 of 12 cases positive), Waldenstrom's macroglobulinemia (2 of 2 cases positive), asymptomatic plasma cell dyscrasia (4 of 4 cases positive), and certain lymphomas (2 of 5 cases positive). Marrow biopsies from lymphocytic (5 cases) and myelogenous (5 cases) leukemias were uniformly negative. The MM4-reactive antigen also was expressed on plasma cells generated from pokeweed mitogen (PWM)-stimulated normal PBM cultures. The pattern of reactivity of MM4 with lymphocytes of B origin was similar to that of the plasma cell MoAb PCA-1. Competitive binding studies showed, however, that these two MoAbs recognized distinct antigenic determinants. These observations suggest that MM4 may be useful for the study of human plasma cell dyscrasias.  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