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   1802篇
  免费   103篇
  国内免费   3篇
耳鼻咽喉   16篇
儿科学   37篇
妇产科学   30篇
基础医学   225篇
口腔科学   35篇
临床医学   130篇
内科学   480篇
皮肤病学   44篇
神经病学   164篇
特种医学   32篇
外科学   224篇
综合类   24篇
一般理论   1篇
预防医学   230篇
眼科学   31篇
药学   86篇
中国医学   12篇
肿瘤学   107篇
  2023年   10篇
  2022年   12篇
  2021年   33篇
  2020年   21篇
  2019年   38篇
  2018年   57篇
  2017年   48篇
  2016年   31篇
  2015年   43篇
  2014年   44篇
  2013年   79篇
  2012年   115篇
  2011年   109篇
  2010年   63篇
  2009年   43篇
  2008年   79篇
  2007年   105篇
  2006年   78篇
  2005年   97篇
  2004年   84篇
  2003年   104篇
  2002年   70篇
  2001年   62篇
  2000年   63篇
  1999年   52篇
  1998年   17篇
  1997年   9篇
  1996年   10篇
  1995年   10篇
  1994年   12篇
  1992年   14篇
  1991年   17篇
  1990年   7篇
  1989年   9篇
  1988年   13篇
  1987年   11篇
  1986年   16篇
  1985年   13篇
  1984年   10篇
  1983年   12篇
  1981年   7篇
  1977年   9篇
  1975年   8篇
  1974年   14篇
  1973年   11篇
  1972年   7篇
  1971年   7篇
  1970年   7篇
  1967年   11篇
  1966年   7篇
排序方式: 共有1908条查询结果,搜索用时 15 毫秒
11.
12.
13.
Necrotizing granulomatous vasculitis in advanced HIV infection   总被引:1,自引:0,他引:1  
We describe the first case of granulomatous necrotizing vasculitis not restricted to the central nervous system in an HIV-infected patient. No mycobacteria or drugs potentially associated with granuloma formation were involved in this patient, suggesting that the cause of this vasculitis was probably autoimmune. The development of granulomatous vascular inflammation in this patient with less than 200 CD4 cells/microl might have been due to immune overactivation. After starting potent antiretroviral therapy a profound immune deactivation was observed and the vasculitis did not relapse.  相似文献   
14.
OBJECTIVE: Analysis of serum concentrations and modifications of tumor necrosis factor-a (TNF-a), its soluble receptors (TNFR), interleukin 10 (IL-10), and vascular related molecules [soluble vascular cell adhesion molecule 1 (sVCAM-1), vascular endothelial growth factor (VEGF)] after therapy with methotrexate (MTX) and anti-TNF (infliximab) in patients with rheumatoid arthritis (RA). METHODS: Thirty-six patients with RA and 20 healthy controls were included. Patients had been orally taking a stable dose of MTX of at least 12.5 mg/week for a minimum of 6 months before inclusion in the study. Twenty-five patients had shown a clinical response to MTX (MTX Group). The other 11 had shown an unsatisfactory response and presented with active RA; they were selected for additional treatment with infliximab (MTX + IFM Group). Disease activity score (DAS28), hemoglobin concentration, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum levels of TNF-a, soluble TNFR, IL-10, sVCAM-1 and VEGF were determined at baseline and prior to every infusion of infliximab (3 mg/kg) at 2, 6, 14, 22, and 30 weeks. RESULTS: Although serum levels of TNF-a were similar in patients and controls, patients showed significantly higher concentrations of both soluble TNFR (sTNFR55 and sTNFR75), IL-10, sVCAM-1, and VEGF than healthy individuals. Significantly higher levels of sVCAM-1 and VEGF, but not of the other tested molecules, were detected in those with active disease. After infliximab treatment (MTX + IFM Group) there was a significant decrease in DAS28 and modified Health Assessment Questionnaire scores and ESR and CRP levels. Serum concentration of VEGF showed a significant decrease after infliximab, with levels comparable to those of patients with inactive RA, although VEGF continued to present higher values than in healthy controls. CONCLUSION: Increased levels of vascular related molecules sVCAM-1 and VEGF are serum markers of active RA. The absence of normalization of levels of these molecules in patients with inactive RA could be one of the reasons response to therapy is only temporary.  相似文献   
15.
The antibody response against Leishmania (Leishmania) amazonensis crude antigen was measured through the indirect immunofluorescent assay (IFA) and the immunoenzymatic assay (ELISA) in 114 patients with cutaneous leishmaniasis (CL) in Brazil. Fifty-four patients were infected by Leishmania (Viannia) braziliensis, and 60 patients had L. (V.) guyanensis infection. Patients were comparable by age, sex, disease duration and the Montenegro skin test diameter. L. (V.) braziliensis-infected patients showed significant lower number of ulcerated lesions, greater ulcerated area and higher proportion of lymph node enlargement. Sensitivity of IFA was 79.6% (95% CI 66.1-88.9) and 71.7% (95% CI 58.4-82.2) for L. (V.) braziliensis and L. (V.) guyanensis-infected patients, respectively (P=0.324). Sensitivity of ELISA was 98.2% (95% CI 88.8-99.9) and 85.0% (95% CI 72.9-92.5) for L. (V.) braziliensis and L. (V.) guyanensis-infected patients, respectively (P=0.018). Significant differences were observed in the magnitude of the antibody response before treatment with higher levels detected in L. (V.) braziliensis-infected patients by both serologic techniques. Eighty-four patients had serologic evaluations before and 12 weeks after treatment with meglumine antimoniate, 20 mg/kg/day for 20 days. Significant lower optic density values were observed after treatment with both species independent of cure or failure. Our data showed that L. (V.) braziliensis induces a higher antibody response against L. (L.) amazonensis antigens than L. (V.) guyanensis and that down-modulation of the antibody response occurs shortly during disease evolution after treatment. Moreover the data support the use of ELISA as a better tool for detection of antibodies in CL.  相似文献   
16.
17.
18.
INTRODUCTION AND OBJECTIVES: To evaluate the clinical characteristics and prognosis of heart failure (HF) development in patients hospitalized for acute myocardial infarction (AMI). PATIENTS AND METHOD: Between May 1990 and March 2000, 836 consecutive patients were admitted with a diagnosis of AMI within 24 h of symptom onset. HF was defined as the presence of rales and a third heart sound with gallop, and evidence of pulmonary congestion on chest x-ray. It was diagnosed in 263 subjects (31.5%). RESULTS: The mean age of patients with HF (group 1) was 63.4 (11.4) years compared with 59.9 (11.6) years in those without HF (group 2) (P<.01). There were differences between groups 1 and 2 in history of diabetes (36% vs 20%; P<.001) or previous HF (9.2% vs 1.1%; P<.001). The reperfusion strategy used in patients with Q-wave infarction, with or without HF, was primary angioplasty in 15% and 14%, respectively (P=.81), and thrombolytic agents in 28% and 37%, respectively (P=.013). Patients with HF were more likely to develop recurrent angina (26.8% vs 19.6%; P=.02), pericarditis (17.5% vs 6.3%; P<.001), and atrial fibrillation (12.3% vs 5.1%; P<.01). In-hospital mortality in groups 1 and 2 was 15.6% and 2.3% (P<.001), respectively, and 10-year survival was 10% and 30%, respectively (P<.001). The variables associated with mortality were: age (HR=1.022; P<.001), hyperglycemia (HR=1.748 per 1.0-g/L increase; P<.001), leukocytosis (HR=1.035 per 1000-cell/.L increase; P<.001), and HF (HR=1.308; P=.028). CONCLUSIONS: AMI is still frequently complicated by HF, which increases short- and long-term morbidity and mortality. Heart failure, age, hyperglycemia, and leukocytosis at admission were independent predictors of mortality during follow-up.  相似文献   
19.
20.
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