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   6095篇
  免费   300篇
  国内免费   25篇
耳鼻咽喉   68篇
儿科学   169篇
妇产科学   110篇
基础医学   914篇
口腔科学   501篇
临床医学   536篇
内科学   1247篇
皮肤病学   138篇
神经病学   485篇
特种医学   97篇
外科学   649篇
综合类   27篇
一般理论   1篇
预防医学   610篇
眼科学   40篇
药学   399篇
中国医学   26篇
肿瘤学   403篇
  2023年   52篇
  2022年   77篇
  2021年   155篇
  2020年   105篇
  2019年   142篇
  2018年   183篇
  2017年   108篇
  2016年   137篇
  2015年   155篇
  2014年   223篇
  2013年   250篇
  2012年   460篇
  2011年   551篇
  2010年   287篇
  2009年   231篇
  2008年   397篇
  2007年   410篇
  2006年   382篇
  2005年   364篇
  2004年   325篇
  2003年   282篇
  2002年   250篇
  2001年   65篇
  2000年   78篇
  1999年   83篇
  1998年   60篇
  1997年   43篇
  1996年   41篇
  1995年   39篇
  1994年   40篇
  1993年   34篇
  1992年   34篇
  1991年   33篇
  1990年   30篇
  1989年   30篇
  1988年   16篇
  1987年   26篇
  1986年   26篇
  1985年   21篇
  1984年   19篇
  1983年   22篇
  1982年   16篇
  1981年   15篇
  1979年   9篇
  1977年   9篇
  1976年   8篇
  1974年   11篇
  1973年   8篇
  1972年   16篇
  1967年   8篇
排序方式: 共有6420条查询结果,搜索用时 109 毫秒
1.
2.
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   
3.
4.
Abstract

The purpose of this study was to investigate the strength of the relationships between self-efficacy and (i) functional exercise capacity and (ii) physical activity in chronic obstructive pulmonary disease (COPD), and whether self-efficacy assessment type (i.e., COPD symptoms, exercise-task, exercise-barrier, general, falls) and physical activity assessment type (i.e., self-report vs. objective) are moderators. A systematic search of COPD and self-efficacy concepts was conducted using eight databases from inception to 23 January 2019. Studies were included if they provided correlation coefficients of the relationship between self-efficacy and functional exercise capacity or physical activity, were conducted in adults diagnosed with COPD, and were published in English-language journals. A total of 14 correlation coefficients were included in the self-efficacy and functional exercise capacity meta-analysis, and 16 in the self-efficacy and physical activity meta-analysis. Data were screened, reviewed, and extracted independently by two reviewers, with discrepancies resolved by a third reviewer. Stronger self-efficacy was associated with better functional exercise capacity (weighted r?=?0.38, 95%CI [0.25, 0.50]), and greater physical activity (weighted r?=?0.25, 95%CI [0.17, 0.34]). Exercise-task self-efficacy had the strongest relationship to functional exercise capacity (weighted r?=?0.64, 95% CI [0.51, 0.73]). For physical activity, the type of self-efficacy most strongly related was inconclusive. In COPD, self-efficacy has a relationship to functional exercise capacity and physical activity, the strength of which is influenced by the choice of self-efficacy measure. An understanding of these relationships will assist clinicians in selecting the self-efficacy measure most closely related to the outcome of interest.  相似文献   
5.
Is it possible to modify intake behaviors for body weight control purposes? Over the last 40 years, dozens of international, peer-reviewed articles have described behavior modification approaches aiming at body weight reduction. The present article first presents a historical account of behavioral methods and their results. From the early therapies exclusively addressing behaviors (excluding restrictive diets) until the recent cognitive-behavioral treatments, published studies have reported modest weight losses associated with numerous metabolic, nutritional and psychological benefits whose maintenance, beyond the treatment duration, appear reasonably good. Recent studies specifically address the conditions of long-term maintenance. The main elements of behavioral-cognitive treatments are described briefly. Finally, the particular problems associated with these approaches in the French context are underlined.  相似文献   
6.
7.
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