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   265863篇
  免费   25545篇
  国内免费   20444篇
耳鼻咽喉   2040篇
儿科学   2323篇
妇产科学   3013篇
基础医学   32710篇
口腔科学   4308篇
临床医学   38300篇
内科学   38917篇
皮肤病学   2405篇
神经病学   15016篇
特种医学   9609篇
外国民族医学   198篇
外科学   25656篇
综合类   44433篇
现状与发展   74篇
一般理论   27篇
预防医学   15945篇
眼科学   8267篇
药学   28442篇
  304篇
中国医学   15976篇
肿瘤学   23889篇
  2024年   3349篇
  2023年   4488篇
  2022年   11397篇
  2021年   14111篇
  2020年   10991篇
  2019年   9385篇
  2018年   9725篇
  2017年   8609篇
  2016年   8159篇
  2015年   12195篇
  2014年   14958篇
  2013年   12541篇
  2012年   18777篇
  2011年   21528篇
  2010年   13028篇
  2009年   10057篇
  2008年   13330篇
  2007年   13361篇
  2006年   13593篇
  2005年   13848篇
  2004年   8200篇
  2003年   7602篇
  2002年   6374篇
  2001年   5695篇
  2000年   6423篇
  1999年   7171篇
  1998年   4736篇
  1997年   4752篇
  1996年   3679篇
  1995年   3514篇
  1994年   2898篇
  1993年   1963篇
  1992年   2213篇
  1991年   1842篇
  1990年   1566篇
  1989年   1333篇
  1988年   1133篇
  1987年   990篇
  1986年   748篇
  1985年   608篇
  1984年   349篇
  1983年   214篇
  1982年   115篇
  1981年   126篇
  1980年   85篇
  1979年   91篇
  1965年   1篇
  1962年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Background: In this study, we coordinated a network meta‐analysis to establish the efficacy and safety of different agents used in the treatment of hyperphosphatemia patients with chronic kidney disease. Methods: PubMed, CNKI, and Embase were systematically searched to retrieve relevant studies. Outcomes were presented by mean differences, odds ratios, and corresponding 95% credible intervals for continuous outcomes and binary outcomes, respectively. Each therapy was ranked according to the value of surface under the cumulative ranking curve. Consistencies between direct and indirect comparisons were assessed with a node‐splitting plot. Results: In terms of efficacy end points (including levels of serum phosphate, serum calcium, serum intact parathyroid hormone, and serum calcium × phosphorus product), all 7 kinds of agents outperformed or performed at least equally to placebo, with iron‐based phosphate‐binding agents being potentially the most effective. As for safety end points (including mortality, adverse events, and all‐cause discontinuation), almost all agents were equivalent in term of mortality and all‐cause discontinuation except in the comparison between iron‐based phosphate‐binding agents and placebo. Meanwhile, iron‐based phosphate‐binding agents colestilan and nicotinic acid performed poorly compared with placebo in terms of adverse events. Furthermore, iron‐based phosphate‐binding agents were potentially the safest agents followed sequentially by calcium‐based phosphate‐binding agents and placebo. Conclusion: Iron‐based phosphate‐binding agents were the preferable agents when considering efficacy and safety simultaneously.  相似文献   
52.
53.
54.
55.
ABSTRACT

Despite significant health benefits of regular physical activity, over 60 percent of college women do not meet recommended physical activity guidelines to promote their health and health-related quality of life (HRQoL), a comprehensive construct including physical and psychosocial health functioning. The major purpose of this study was to examine the influences of individual (e.g., self-efficacy, enjoyment), social (e.g., family and friend support), and physical environmental factors (e.g., crime safety) on college women’s physical activity and HRQoL. Participants were 235 (Mean age = 21.0 years) college women from a public research university located in the southwest region of the United States. They completed validated surveys assessing their perceptions of physical activity, HRQoL, and social ecological factors during the spring semester of 2012. The findings of three multiple linear regressions, entering individual factors first, followed by social and physical environmental factors, revealed that self-efficacy and crime safety were significantly related to physical activity. For HRQoL-physical functioning, significant factors were self-efficacy, enjoyment, and crime safety. Enjoyment was the only factor related to HRQoL-psychosocial functioning. These findings indicated that physical activity professionals need to foster safe environments, enhance self-efficacy, and provide enjoyable activities to promote college women’s physical activity and HRQoL.  相似文献   
56.
Context: MOTILIPERM was prepared as a mixture of extracts of three medicinal herbs [roots of Morinda officinalis How (Rubiaceae), outer scales of Allium cepa L. (Liliaceae) and seeds of Cuscuta chinensis Lamark (Convolvulaceae)].

Objective: To investigate the role of reactive oxygen species (ROS)-based endoplasmic reticulum (ER) stress in a rat model of varicocele and the therapeutic efficacy of MOTILIPERM in this model.

Materials and methods: Sixty male rats were divided into five experimental groups: a normal control group (CTR?+?vehicle), a control group administered MOTILIPERM 200?mg/kg (CTR?+?M 200), a varicocele-induced control group (VC?+?vehicle) and two varicocele-induced groups administered MOTILIPERM 100 (VC?+?M 100) or 200 (VC?+?M 200) mg/kg for 4 weeks. Testis weights were recorded and serums were assayed for hormone concentrations. Tissues were subjected to semen analysis, histopathology, analyses of ER response protein expression levels and oxidative stress were assessed by measuring ROS, reactive nitrogen species (RNS), malondialdehyde (MDA) level and ratios of total glutathione (GSH)/oxidized GSH (GSSG).

Results: MOTILIPERM treatment of varicocele-induced groups significantly increased left testis weight, testosterone level, sperm motility, count and spermatogenic cell density. ER-response protein expression levels were dose-dependently decreased in VC?+?M 200 group compared with VC?+?vehicle group. MOTILIPERM treatment also decreased MDA and ROS/RNS level but increased GSH/GSSG ratio.

Discussion and conclusions: This study suggests that ROS-related ER stress may play a major role in varicocele-induced infertility and MOTILIPERM, a novel compound targeting ROS-based ER stress, may be therapeutically useful in treatment of varicocele, or as a supplement for the treatment of infertility.  相似文献   
57.
58.
59.
60.
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