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   870篇
  免费   34篇
  国内免费   3篇
儿科学   72篇
妇产科学   11篇
基础医学   73篇
口腔科学   25篇
临床医学   80篇
内科学   212篇
皮肤病学   21篇
神经病学   16篇
特种医学   250篇
外科学   38篇
综合类   10篇
预防医学   31篇
眼科学   4篇
药学   26篇
中国医学   1篇
肿瘤学   37篇
  2023年   2篇
  2022年   2篇
  2021年   2篇
  2020年   1篇
  2018年   11篇
  2017年   9篇
  2016年   7篇
  2015年   10篇
  2014年   15篇
  2013年   14篇
  2012年   14篇
  2011年   6篇
  2010年   33篇
  2009年   38篇
  2008年   21篇
  2007年   13篇
  2006年   16篇
  2005年   11篇
  2004年   10篇
  2003年   13篇
  2002年   7篇
  2001年   8篇
  2000年   4篇
  1999年   11篇
  1998年   49篇
  1997年   65篇
  1996年   49篇
  1995年   40篇
  1994年   50篇
  1993年   51篇
  1992年   9篇
  1991年   10篇
  1990年   10篇
  1989年   36篇
  1988年   39篇
  1987年   28篇
  1986年   28篇
  1985年   26篇
  1984年   11篇
  1983年   21篇
  1982年   17篇
  1981年   18篇
  1980年   21篇
  1979年   3篇
  1978年   8篇
  1977年   12篇
  1976年   9篇
  1975年   17篇
  1973年   1篇
  1948年   1篇
排序方式: 共有907条查询结果,搜索用时 15 毫秒
851.
852.
Perianal fistulas: use of MR imaging for diagnosis   总被引:3,自引:0,他引:3  
  相似文献   
853.
Bladder cancer: staging with CT and MR imaging   总被引:10,自引:0,他引:10  
Magnetic resonance (MR) imaging and computed tomography (CT) were compared in 30 patients with histologically proved bladder cancer. MR imaging was accurate in depicting the presence or absence of extravesical spread in 22 patients (accuracy, 73%; sensitivity, 82%; specificity, 62%), and CT was accurate in 24 patients (accuracy, 80%; sensitivity, 94%; specificity, 62%). The MR examinations of two patients were of undiagnostic quality and therefore considered to be technical failures. Each technique resulted in five false-positive and one false-negative examination for the diagnosis of extravesical tumor spread. In 28 patients the integrity of the bladder wall was assessed with MR imaging. In 22 patients the bladder wall was disrupted, and 18 of these patients had deep muscle invasion. In six patients the bladder wall was intact, and none of these patients had evidence of deep muscle invasion at pathologic examination. In this study MR imaging was slightly inferior to CT in the delineation of invasive tumors beyond the bladder wall. However, if one excludes from analysis the two patients with undiagnostic studies, there is no significant difference in accuracy between the two techniques.  相似文献   
854.
Corbett  SA; Wilson  CL; Schwarzbauer  JE 《Blood》1996,88(1):158-166
Plasma fibronectin (pFN) cross-linked to fibrin during the injury response provides a provisional matrix required for cells to begin tissue repair. Using a synthetic matrix of pFN and fibrin as a substrate for cell adhesion and spreading, we have determined that pFN covalently cross-linked to fibrin into a complex multimer is functionally distinct from pFN immobilized onto a plastic surface. NIH- 3T3 cells on a FN-fibrin matrix reach 50% of the maximal cell area of cells spread on FN-coated plastic. They neither attach nor spread on cross-linked fibrin alone. Cells on pFN-fibrin matrices form few prominent stress fibers and exhibit clear differences in membrane ruffling and filopodial extension when stained with rhodamine-labeled phalloidin. Interestingly, these differences are enhanced by upregulation of protein kinase C. These data suggest that cell-FN interactions can be modified by the molecular context of the protein within the extracellular matrix resulting in distinct cell morphology and cytoskeletal organization.  相似文献   
855.
A method for rapid prenatal diagnosis of glycogenosis II (Pompe's disease)   总被引:3,自引:0,他引:3  
A method is described enabling prenatal diagnosis of glycogenosis II (Pompe's disease) within 7–10 days after amniocentesis in the 14th–16th week of pregnancy. The procedure is based on amniotic fluid cell cultivation on thin plastic foil, freezing and freeze-drying of the cells and subsequent microdissection of pieces of plastic foil each containing 70–250 lyophilized cells. These are incubated in microliter volumes of substrate. The extinction or fluorescence values are measured in microcuvettes adapted to a normal spectrofluorometer or in microcapillaries using a microscope spectrofluorometer design. The methods developed are compared with conventional biochemical analyses.  相似文献   
856.
Pulse Cyclophosphamide for Severe Neuropsychiatric Lupus   总被引:1,自引:1,他引:0  
We Studied the effect of parenteral pulse cyclophosphamide therapyin nine patients with active systemic lupus erythematosus andsevere central nervous system involvement. Seven patients hadfocal neurological deficits and/or seizures associated withabnormalities on cerebrospinal fluid analysis and/or magneticresonance imaging. Two patients had organic brain syndrome withpsychosis and normal cerebrospinal fluid and/or magnetic resonanceimaging analysis. Six patients were unresponsive to treatmentwith high dose corticosteroid. Cyclophosphamide 0.75–1.0g/m2 body surface area, was administered intravenously everymonth for at least 2 months. Eight patients had a complete recoveryor recovered with minor residuals. Cyclophosphamide was welltolerated with few side effects. We conclude that parenteralpulse cyclophosphamide is an effective adjunctive therapy forthe management of patients with active systemic lupus erythematosusand central nervous system symptoms.  相似文献   
857.
858.
Over the past 6 years, the authors evaluated 300 patients with hepatoma as part of phase 1 and 2 treatment protocol trials. Analysis of the available clinical data and radiographic studies revealed 22 patients (7.3%) with skeletal metastases demonstrated by radiography, computed tomography (CT), and/or nuclear scintigraphy. The plain film appearance of skeletal metastases from hepatoma was osteolytic in all cases. CT scanning best demonstrated the expansile, destructive nature of these metastases, which were often associated with large, bulky soft-tissue masses. Skeletal metastases from hepatomas demonstrated increased radiotracer uptake on standard bone scans and were gallium avid, similar to the hepatoma itself. In addition, they could be targeted therapeutically with I-131 antiferritin immunoglobulin. The most frequent sites of skeletal metastases were the ribs, spine, femur, pelvis, and humerus. An initial symptom in ten patients was skeletal pain corresponding to the osseous metastases. In five patients, pathologic fractures of the proximal femur or humerus developed and required total hip replacement or open-reduction internal fixation. Patients with long-standing cirrhosis or known hepatocellular carcinoma who also have skeletal symptoms should be evaluated for possible osseous metastases.  相似文献   
859.
Transvenous inferior vena caval filters were placed in 32 patients (21 bird's nest [BN] and 11 Kimray-Greenfield [K-G] filters). Positive contrast cavography was performed before and immediately after filter placement as well as during long-term follow-up studies. In 23 patients, computed tomographic (CT) scanning was also performed; in 10 patients, real-time ultrasound (US) study was used as an adjunct. CT scans of the BN filter showed one case of hemorrhage and one case of air embolism, both of which were not recognized at cavography. CT scanning of the K-G filter demonstrated two cases of deep penetration of the prongs and one large retroperitoneal hematoma. Real-time US scanning played a major role in checking the final position of the filter and in determining its stability during repositioning of the upper prongs of one BN filter. Noninvasive examinations, including CT and US scanning, are valuable adjuncts in immediate and long-term follow-up study of patients with inferior vena caval filters.  相似文献   
860.
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