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   1266篇
  免费   93篇
  国内免费   47篇
耳鼻咽喉   5篇
儿科学   53篇
妇产科学   34篇
基础医学   164篇
口腔科学   48篇
临床医学   159篇
内科学   316篇
皮肤病学   17篇
神经病学   59篇
特种医学   168篇
外科学   101篇
综合类   34篇
预防医学   80篇
眼科学   3篇
药学   111篇
  1篇
肿瘤学   53篇
  2023年   8篇
  2022年   8篇
  2021年   18篇
  2020年   10篇
  2019年   11篇
  2018年   20篇
  2017年   20篇
  2016年   23篇
  2015年   30篇
  2014年   37篇
  2013年   54篇
  2012年   41篇
  2011年   37篇
  2010年   36篇
  2009年   30篇
  2008年   36篇
  2007年   55篇
  2006年   36篇
  2005年   44篇
  2004年   21篇
  2003年   23篇
  2002年   27篇
  2001年   22篇
  2000年   35篇
  1999年   35篇
  1998年   51篇
  1997年   63篇
  1996年   59篇
  1995年   45篇
  1994年   40篇
  1993年   34篇
  1992年   18篇
  1991年   30篇
  1990年   25篇
  1989年   26篇
  1988年   34篇
  1987年   24篇
  1986年   24篇
  1985年   24篇
  1984年   12篇
  1983年   15篇
  1982年   15篇
  1981年   10篇
  1980年   23篇
  1979年   8篇
  1978年   15篇
  1977年   26篇
  1976年   8篇
  1973年   7篇
  1966年   6篇
排序方式: 共有1406条查询结果,搜索用时 15 毫秒
51.
In cor triatriatum sinister, one of the rarest congenital cardiac anomalies, a membrane divides the left atrium into a pulmonary venous component above and the vestibule below. The importance of the anomaly lies in the effects of the resultant pulmonary venous obstruction that usually present in the first year of life and can mimic obstructed total anomalous venous drainage or congenital mitral stenosis. A case presented as mitral stenosis in the third decade of life, ten years after a well documented episode of Sydenham's chorea. The diagnosis was made rapidly by transthoracic echocardiography and transoesophageal echocardiography was used for complete assessment. Cardiac catheterisation added nothing to the non-invasive diagnosis or the preoperative assessment. Uncomplicated corrective surgery was undertaken.  相似文献   
52.
Residual HIV-infected blood in needles and syringes is a source of HIV infection. Using radiolabelled blood we have stimulated needlestick injuries and sharing of syringes by intravenous drug users and quantified the volumes of blood which could be transferred to recipients in these situations. Up to 0.75 microliters of blood was transferred in needlestick simulations, but there was a large variation. In simulations of needlesharing, seven to ten times more blood was transferred from the index user to the first sharer when 2 ml syringes were used compared with 1 ml syringes. Washing with water was not effective in removing 'infected' blood from a syringe.  相似文献   
53.
54.
Manometry of the alimentary tract is a valuable and widely used means to evaluate and diagnose the function of the alimentary tract. However, the measurement can be inconvenient due to the invasive method used, and the many factors affecting results. Research on colonic pressure data is even more insufficient. This paper deals with colonic pressure data via an improved method ensuring that pressure data of the whole colon is available. The data is analysed based on the learning vector quantization (LVQ) method. Testing results show that this method distinguishes the normal data and the abnormal data, consistently with the original diagnoses. This method can serve as an assistant diagnosis of colonic motility and contributes to further research on colonic motility based on pressure data.  相似文献   
55.
56.
BackgroundVenoarterial extracorporeal membrane oxygenation (V-A ECMO) improves perfusion and oxygenation in patients with cardiogenic shock. However, it can also result in supranormal oxygen exposure. Recent evidence suggests hyperoxia may be harmful, particularly in critically ill patients. The aim of this study was to describe oxygen exposure in patients receiving V-A ECMO after acute myocardial infarction and to investigate the association between hyperoxia and in-hospital mortality.Methods and designWe conducted a retrospective, cohort study of consecutive patients receiving V-A ECMO at a single tertiary level ECMO centre. We compared the mean and peak arterial oxygen tensions over the first 72 h after V-A ECMO initiation (n = 30) with those from a convenience sample of patients treated with an intra-aortic balloon pump (IABP) (n = 30) for cardiogenic shock.ResultsSixty patients admitted between January 2012 and March 2018 were included in the study. Patients on V-A ECMO had significantly higher arterial oxygen tensions during the first three days than those with an IABP, at 0–24 h; V-A ECMO: 286.51 mmHg (135.76) vs IABP: 103.48 mmHg (15.22), p < 0.01.Thirteen of 30 (44.8%) patients in the V-A ECMO cohort manifested extreme hyperoxia (PaO2 ≥300 mmHg) in the first 24 hrs, compared with none in the IABP population. Within the V-A ECMO group, there was no significant association between extreme hyperoxia and in-hospital mortality (P = 0.19), duration of mechanical ventilation (P = 0.63), or troponin levels (P = 0.16) in the first 24 hrs.ConclusionSevere hyperoxia is common in patients receiving V-A ECMO after acute myocardial infarction, and this continues for at least 72 h. We found no association between extreme hyperoxia and clinical outcomes.  相似文献   
57.
We describe a patient with angioimmunoblastic lymphadenopathy with dysproteinemia (AILD), who subsequently developed large-cell immunoblastic lymphoma of B-cell immunophenotype. At the time of the initial diagnosis, histologic examination of an inguinal lymph node showed typical features of AILD, and there was no evidence of a monoclonal B-cell population by immunohistochemical analysis. In situ hybridization and Southern blot analysis for Epstein-Barr virus (EBV) were negative. At autopsy 2 years later, the patient had widespread lymph node and organ involvement by large-cell immunoblastic lymphoma of B-cell immunophenotype. Southern blot analysis performed on DNA extracted from lymph nodes, liver, and spleen showed two patterns of Ig heavy chain and kappa light chain gene rearrangements. The T-cell receptor beta chain gene was in the germline configuration. Analysis with an EBV terminal repeat region probe showed two clonal populations that paralleled the Ig gene rearrangement studies. Double-labeling immunohistochemistry and in situ hybridization confirmed the presence of EBV within the neoplastic B cells. The data support the hypothesis that EBV was not etiologically related to AILD in this case, and that EBV proliferation may occur after the onset of the disease. Further, the data suggest that some B-cell lymphomas that arise in the setting of AILD resemble EBV-associated B-cell lymphomas that arise in other immunodeficiency states.  相似文献   
58.
Ley  K; Linnemann  G; Meinen  M; Stoolman  LM; Gaehtgens  P 《Blood》1993,81(1):177-185
Leukocyte rolling in venules is inhibited by several sulfated polysaccharides, by antibodies to the leukocyte adhesion receptor L- selectin (LECAM-1), and by recombinant soluble L-selectin. The sulfated fucose polymer fucoidin and the polyphosphomannan PPME bind to L- selectin and inhibit L-selectin-mediated lymphocyte adhesion to lymph node high endothelial venules (LN-HEV). We investigated whether fucoidin and PPME also inhibit leukocyte rolling. Rolling leukocyte flux was determined by intravital microscopy in 47 venules (diameter 21 to 50 microns) of the rat mesentery with and without micro-infusion of each reagent through 8-microns glass micropipettes. Micro-infusion (1 mg/mL) or intravenous (IV) injection (25 mg/kg) of fucoidin, but not vehicle, reduced leukocyte rolling by greater than 90%. The half- effective concentration was approximately 2.5 micrograms/mL. Stroboscopic fluorescence video microscopy showed that fucoidin decreased the fraction of rolling leukocytes from 44% of all leukocytes passing the venules in control to less than 1%. PPME micro-infusion (1 mg/mL) or IV injection (14 mg/kg) did not reduce leukocyte rolling. Hence, leukocyte rolling differs from lymphocyte homing with respect to the effect of PPME. This may be related to fucoidin binding to L- selectin with greater affinity than PPME. Alternatively, inflamed venular endothelium may express a ligand for L-selectin different from that constitutively expressed on LN-HEV.  相似文献   
59.
60.
该文旨在介绍Beth Israel医疗中心采用大剂量术中放疗(HDR-IORT)治疗复发头颈癌的经验。对2001-2010年间头颈癌局部复发接受大剂量HDR-IORT的患者进行回顾分析。结果,76例患者的87个部位在肿瘤切除后接受了治疗。术后2年控制率为62%。平均总生存期为19个月,其中42%的患  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