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   38546篇
  免费   2775篇
  国内免费   67篇
耳鼻咽喉   417篇
儿科学   1262篇
妇产科学   1060篇
基础医学   5125篇
口腔科学   464篇
临床医学   5010篇
内科学   7203篇
皮肤病学   562篇
神经病学   4013篇
特种医学   813篇
外国民族医学   13篇
外科学   3621篇
综合类   372篇
一般理论   46篇
预防医学   4898篇
眼科学   770篇
药学   2503篇
  1篇
中国医学   28篇
肿瘤学   3207篇
  2024年   45篇
  2023年   312篇
  2022年   548篇
  2021年   1185篇
  2020年   732篇
  2019年   1102篇
  2018年   1236篇
  2017年   902篇
  2016年   1039篇
  2015年   1094篇
  2014年   1443篇
  2013年   2019篇
  2012年   2963篇
  2011年   3216篇
  2010年   1700篇
  2009年   1418篇
  2008年   2612篇
  2007年   2632篇
  2006年   2367篇
  2005年   2285篇
  2004年   2042篇
  2003年   1785篇
  2002年   1797篇
  2001年   393篇
  2000年   369篇
  1999年   360篇
  1998年   377篇
  1997年   285篇
  1996年   221篇
  1995年   237篇
  1994年   186篇
  1993年   139篇
  1992年   197篇
  1991年   169篇
  1990年   164篇
  1989年   140篇
  1988年   150篇
  1987年   128篇
  1986年   123篇
  1985年   84篇
  1984年   83篇
  1983年   100篇
  1982年   76篇
  1981年   68篇
  1980年   50篇
  1979年   74篇
  1978年   44篇
  1977年   43篇
  1976年   50篇
  1974年   40篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Akteure der öffentlichen Gesundheit (Public Health) tragen wesentlich zu Gesundheitsschutz, -förderung und...  相似文献   
2.
3.
Despite orientation and mobility (O&M) being a significant factor determining quality of life of people with low vision or blindness, there are no gold standard measures or agreement on how to measure O&M performance. In the first part of this systematic review, an inventory of O&M outcome measures used by recent studies to assess the performance of orientation and/or mobility of adults with vision impairment (low vision and blindness) is presented. A wide variety of O&M outcome measures have been implemented in different fields of study, such as epidemiologic research and interventional studies evaluating training, assistive technology, vision rehabilitation and vision restoration. The most frequent aspect of outcome measures is efficiency such as time, distance, speed and percentage of preferred walking speed, followed by obstacle contacts and avoidance, and dis/orientation and veering. Other less commonly used aspects are target identification, safety and social interaction and self-reported outcome measures. Some studies employ sophisticated equipment to capture and analyse O&M performance in a laboratory setting, while others carry out their assessment in real-world indoor or outdoor environments. In the second part of this review, the appropriateness of implementing the identified outcome measures to assess O&M performance in clinical and functional O&M practice is evaluated. Nearly a half of these outcome measures meet all four criteria of face validity (either clinical or functional), responsiveness, reliability and feasibility and have the potential to be implemented in clinical or functional O&M practice. The findings of this review confirm the complicated and dynamic nature of O&M. Multiple measures are required in any evaluation of O&M performance to facilitate holistic assessment of O&M abilities and limitations of each individual.  相似文献   
4.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support.  相似文献   
5.
6.
7.
8.
9.
Serum thromboxane-B2 (TxB2), together with arachidonic acid (AA)-induced platelet aggregation, are, at the moment, the most used tests to identify patients displaying high on-aspirin treatment platelet reactivity (HAPR). Both tests are specific for aspirin action on cyclooxygenase-1. While the correlation between serum TxB2 assay and clinical outcome is established, data are conflicting with regard to aspirin treatment and a possible association with AA-stimulated platelet markers and clinical outcome. To understand such discrepancy, we performed a retrospective study to compare both assays. We collected data from 132 patients receiving a daily dose of aspirin (100?mg/day) and data from 48 patients receiving aspirin on alternate days. All Patients who received a daily dose of aspirin were studied for AA-induced platelet aggregation together with serum TxB2 levels and AA-induced TxB2 formation was also studied in 71 patients out of entire population. Consistent with recommendations in the literature, we defined HAPR by setting a cut-off point at 3.1?ng/ml for serum levels of thromboxane B2 and 20% for AA-induced platelet aggregation. According to this cut-off point, we divided our overall population into two groups: (1) TxB2?<?3.1?ng/ml and (2) TxB2?>?3.1?ng/ml. We found low agreement between such tests to identify patients displaying HAPR. Our results show that AA-induced platelet aggregation >20% identify a smaller number of HAPR patients in comparison with TxB2. A good correlation between serum TxB2 and arachidonic acid-induced TxB2 production was found (r?=?0.76619).  相似文献   
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