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   25444篇
  免费   1883篇
  国内免费   96篇
耳鼻咽喉   427篇
儿科学   833篇
妇产科学   616篇
基础医学   3351篇
口腔科学   1360篇
临床医学   2061篇
内科学   6095篇
皮肤病学   712篇
神经病学   2047篇
特种医学   547篇
外科学   3545篇
综合类   138篇
现状与发展   1篇
一般理论   10篇
预防医学   2316篇
眼科学   467篇
药学   1510篇
中国医学   116篇
肿瘤学   1271篇
  2023年   204篇
  2022年   449篇
  2021年   918篇
  2020年   562篇
  2019年   935篇
  2018年   986篇
  2017年   661篇
  2016年   726篇
  2015年   835篇
  2014年   1074篇
  2013年   1280篇
  2012年   1751篇
  2011年   1872篇
  2010年   1088篇
  2009年   847篇
  2008年   1401篇
  2007年   1428篇
  2006年   1316篇
  2005年   1190篇
  2004年   1056篇
  2003年   946篇
  2002年   869篇
  2001年   573篇
  2000年   684篇
  1999年   517篇
  1998年   169篇
  1997年   111篇
  1996年   103篇
  1995年   103篇
  1994年   103篇
  1993年   79篇
  1992年   254篇
  1991年   248篇
  1990年   219篇
  1989年   212篇
  1988年   144篇
  1987年   141篇
  1986年   129篇
  1985年   142篇
  1984年   88篇
  1983年   69篇
  1980年   48篇
  1979年   83篇
  1978年   79篇
  1975年   70篇
  1974年   75篇
  1973年   67篇
  1972年   57篇
  1971年   44篇
  1970年   50篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
4.
Objective: Polyunsaturated fatty acids n-3 (PUFA n-3) have shown effects in reducing tumor growth, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) abundantly present in fish oil (FO). When these fatty acids are provided in the diet, they alter the functions of the cells, particularly in tumor and immune cells. However, the effects of α-linolenic fatty acid (ALA), which is the precursor of EPA and DHA, are controversial. Thus, our objective was to test the effect of this parental fatty acid. Methods: Non-tumor-bearing and tumor-bearing Wistar rats (70 days) were supplemented with 1 g/kg body weight of FO or Oro Inca® (OI) oil (rich in ALA). Immune cells function, proliferation, cytokine production, and subpopulation profile were evaluated. Results: We have shown that innate immune cells enhanced phagocytosis capacity, and increased processing and elimination of antigens. Moreover, there was a decrease in production of pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6)) by macrophages. Lymphocytes showed decreased proliferation capacity, increased cluster of differentiation 8 (CD8+) subpopulation, and increased TNF-α production. Conclusions: Oil rich in ALA caused similar immune modulation in cancer when compared with FO.  相似文献   
5.
6.
7.
ABSTRACT

Introduction

‘Critical Asthma Syndrome’ (CAS) is an umbrella term proposed to include several forms of asthma, responsible for acute and life-threatening exacerbations. CAS requires urgent and adequate supportive and pharmacological treatments to prevent serious outcomes.  相似文献   
8.
9.
10.
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