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   7256篇
  免费   348篇
  国内免费   24篇
耳鼻咽喉   78篇
儿科学   191篇
妇产科学   154篇
基础医学   812篇
口腔科学   329篇
临床医学   537篇
内科学   1567篇
皮肤病学   218篇
神经病学   641篇
特种医学   137篇
外科学   1168篇
综合类   37篇
一般理论   1篇
预防医学   673篇
眼科学   203篇
药学   382篇
中国医学   62篇
肿瘤学   438篇
  2023年   55篇
  2022年   100篇
  2021年   253篇
  2020年   131篇
  2019年   201篇
  2018年   250篇
  2017年   145篇
  2016年   163篇
  2015年   182篇
  2014年   277篇
  2013年   337篇
  2012年   593篇
  2011年   569篇
  2010年   331篇
  2009年   299篇
  2008年   492篇
  2007年   539篇
  2006年   436篇
  2005年   457篇
  2004年   406篇
  2003年   375篇
  2002年   366篇
  2001年   55篇
  2000年   49篇
  1999年   62篇
  1998年   45篇
  1997年   32篇
  1996年   32篇
  1995年   30篇
  1994年   19篇
  1993年   24篇
  1992年   23篇
  1991年   21篇
  1990年   14篇
  1989年   20篇
  1988年   18篇
  1987年   13篇
  1986年   14篇
  1985年   11篇
  1984年   16篇
  1983年   13篇
  1982年   19篇
  1981年   15篇
  1980年   15篇
  1979年   18篇
  1978年   12篇
  1977年   10篇
  1976年   8篇
  1975年   10篇
  1973年   8篇
排序方式: 共有7628条查询结果,搜索用时 15 毫秒
951.
Abstract

Background and aims

The diagnostic yield (DY) and therapeutic yield (TY) of balloon-assisted enteroscopy (BAE) in overt obscure gastrointestinal bleeding (OGIB) is higher in the first 72?h. This study aimed to evaluate if this higher DY and TY after urgent BAE impacted the rebleeding rate, time to rebleed and short-term mortality.  相似文献   
952.
OBJECTIVE: T-cell depletion (TCD), primarily developed to prevent graft-vs-host disease (GVHD), might reduce early liver dysfunction after allogeneic hematopoietic stem cell transplantation. However, no comparative studies have been performed to investigate this. We analyzed the influence of selection for CD34(+) cells on the incidence and severity of hepatic veno-occlusive disease (VOD). PATIENTS AND METHODS: Five hundred and one patients who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) from HLA-identical siblings were included in the present study. Two hundred and ninety patients (59%) were grafted with CD34+ positively selected grafts and 211 (41%) with nonmanipulated grafts. Their mean age was 38 years (range 17-63). All patients had hematological malignancies and 96% were conditioned with combinations either of cyclophosphamide plus total-body irradiation or of cyclophosphamide plus busulphan. Most of the patients received GVHD prophylaxis with methotrexate (MTX) or cyclosporin A. RESULTS: Fifty-two patients (10.4%) developed VOD. VOD was more frequent in patients receiving nonmanipulated grafts (16.1% vs 6.2%; p<0.0009), in those with a Karnofsky score less than 90 (17.5% vs 7.8%; p=0.001), and with the use of MTX for GVHD prophylaxis (14.8% vs 7%; p=0.005). In multivariate analyses, only CD34+ positive selection (p=0.0007) and Karnofsky score (p=0.004) emerged as independent risk factors for VOD. The same effect was observed in the subset of patients with severe VOD. CONCLUSION: These findings show that CD34+ selection not only decreases the incidence of GVHD but also prevents VOD after HLA-identical sibling PBSCT.  相似文献   
953.
954.
955.
This is a case report of the first patient with Alagille syndrome (AGS) to undergo a partial internal biliary diversion (PIBD) for the treatment of symptoms refractory to medical therapy. Alagille syndrome is a hereditary disease resulting in chronic cholestasis and hypercholesterolemia that can lead to severe and intractable pruritus and disfiguring and debilitating xanthomas. PIBD has proven to be an effective treatment option for other causes of cholestatic liver disease. This report reviews the immediate and 2-year follow-up of a patient after this surgical procedure. The results suggest that PIBD has potential to provide relief of intractable symptoms and improve the quality of life in patients with AGS while avoiding an external stoma. It does not, however, appear to prevent the progression of liver disease. Long-term follow-up is still needed.  相似文献   
956.
957.
958.
959.
960.
The intracardiac injection model is a commonly used in vivo model to test therapeutic response in bone metastases. However, few studies have critically compared the performance of different imaging methods in terms of sensitivity and quantitative assessment of osteolytic lesions. We performed in vivo optical and plain radiographic imaging of bone metastases followed by high-sensitivity ex vivo micro-computed tomography (micro-CT) imaging. This approach allowed for quantitative assessment of in vivo imaging techniques using fluorescence and plain radiography. Comparison of lesions detected in vivo by fluorescent optical imaging with ex vivo micro-CT revealed that the limited spatial resolution of fluorescent optical imaging may underestimate the number of bone metastases. Radiography was compared with micro-CT for the detection of osteolytic lesions. When using dichotomous yes/no grading, there was a 64% agreement in detection of osteolytic lesions. When subjective semiquantitative grading methods were used to assess the extent of osteolytic lesions, a positive association between the micro-CT grades and the square root of the radiography-based grades was observed (p < 0.05). Micro-CT also showed a significant association with fluorescent optical values; however, no such association was observed between lesion scores based on radiographs and those based on fluorescent imaging. The findings reveal an approximate two-fold sensitivity for micro-CT compared to plain radiography in the detection of osteolytic lesions. Significant associations between micro-CT-based osteolytic lesion grade and tumor growth characterized by increased fluorescent area document the value of these two techniques for the assessment of osteolytic bone metastases.  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