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   997404篇
  免费   80949篇
  国内免费   2538篇
耳鼻咽喉   14083篇
儿科学   28157篇
妇产科学   27613篇
基础医学   142704篇
口腔科学   28734篇
临床医学   88644篇
内科学   193115篇
皮肤病学   19701篇
神经病学   83322篇
特种医学   40738篇
外国民族医学   177篇
外科学   156582篇
综合类   26322篇
现状与发展   4篇
一般理论   399篇
预防医学   76931篇
眼科学   23485篇
药学   74145篇
中国医学   1819篇
肿瘤学   54216篇
  2018年   10420篇
  2016年   9294篇
  2015年   10887篇
  2014年   15582篇
  2013年   22893篇
  2012年   32051篇
  2011年   33750篇
  2010年   19541篇
  2009年   18501篇
  2008年   31709篇
  2007年   34285篇
  2006年   33773篇
  2005年   33719篇
  2004年   32694篇
  2003年   31343篇
  2002年   29919篇
  2001年   37215篇
  2000年   37505篇
  1999年   32330篇
  1998年   11125篇
  1997年   10038篇
  1996年   9774篇
  1995年   9191篇
  1994年   8764篇
  1993年   8232篇
  1992年   27378篇
  1991年   26829篇
  1990年   26186篇
  1989年   25231篇
  1988年   23744篇
  1987年   23402篇
  1986年   22213篇
  1985年   21577篇
  1984年   16958篇
  1983年   14532篇
  1982年   9543篇
  1981年   8836篇
  1979年   17068篇
  1978年   12464篇
  1977年   10560篇
  1976年   9650篇
  1975年   10422篇
  1974年   12880篇
  1973年   12346篇
  1972年   11700篇
  1971年   10792篇
  1970年   10327篇
  1969年   9983篇
  1968年   8982篇
  1967年   8286篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.

Physical activity brings significant health benefits to middle-aged adults, although the research to date has been focused on late adulthood. This study aims to examine how ageing affects the self-reported and accelerometer-derived measures of physical activity levels in middle-aged adults. We employed the data recorded in the UK Biobank and analysed the physical activity levels of 2,998 participants (1381 men and 1617 women), based on self-completion questionnaire and accelerometry measurement of physical activity. We also assessed the musculoskeletal health of the participants using the dual-energy X-ray absorptiometry (DXA) measurements provided by the UK Biobank. Participants were categorised into three groups according to their age: group I younger middle-aged (40 to 49 years), group II older middle-aged (50 to 59 years), and group III oldest middle-aged (60 to 69 years). Self-reported physical activity level increased with age and was the highest in group III, followed by group II and I (P?<?0.05). On the contrary, physical activity measured by accelerometry decreased significantly with age from group I to III (P?<?0.05), and the same pertained to the measurements of musculoskeletal health (P?<?0.05). It was also shown that middle-aged adults mostly engaged in low and moderate intensity activities. The opposing trends of the self-reported and measured physical activity levels may suggest that middle-aged adults over-report their activity level as they age. They should be aware of the difference between their perceived and actual physical activity levels, and objective measures would be useful to prevent the decline in musculoskeletal health.

  相似文献   
2.
Die Anaesthesiologie - Auch wenn für Anästhesiologen über Jahrzehnte die Prophylaxe und Therapie postoperativer Schmerzen im Rahmen des postoperativen Patientenkomforts an vorderster...  相似文献   
3.
4.
Die Anaesthesiologie - Die Anlage einer Magensonde im OP oder auf einer Intensivstation (ITS) stellt eine alltäglich durchgeführte Prozedur dar. Obwohl die Sonde häufig durch...  相似文献   
5.
PurposeUnderstanding the value of genetic screening and testing for monogenic disorders requires high-quality, methodologically robust economic evaluations. This systematic review sought to assess the methodological quality among such studies and examined opportunities for improvement.MethodsWe searched PubMed, Cochrane, Embase, and Web of Science for economic evaluations of genetic screening/testing (2013-2019). Methodological rigor and adherence to best practices were systematically assessed using the British Medical Journal checklist.ResultsAcross the 47 identified studies, there were substantial variations in modeling approaches, reporting detail, and sophistication. Models ranged from simple decision trees to individual-level microsimulations that compared between 2 and >20 alternative interventions. Many studies failed to report sufficient detail to enable replication or did not justify modeling assumptions, especially for costing methods and utility values. Meta-analyses, systematic reviews, or calibration were rarely used to derive parameter estimates. Nearly all studies conducted some sensitivity analysis, and more sophisticated studies implemented probabilistic sensitivity/uncertainty analysis, threshold analysis, and value of information analysis.ConclusionWe describe a heterogeneous body of work and present recommendations and exemplar studies across the methodological domains of (1) perspective, scope, and parameter selection; (2) use of uncertainty/sensitivity analyses; and (3) reporting transparency for improvement in the economic evaluation of genetic screening/testing.  相似文献   
6.
7.
8.
Fibroblast growth factor receptors (FGFRs) are aberrantly activated through single-nucleotide variants, gene fusions and copy number amplifications in 5–10% of all human cancers, although this frequency increases to 10–30% in urothelial carcinoma and intrahepatic cholangiocarcinoma. We begin this review by highlighting the diversity of FGFR genomic alterations identified in human cancers and the current challenges associated with the development of clinical-grade molecular diagnostic tests to accurately detect these alterations in the tissue and blood of patients. The past decade has seen significant advancements in the development of FGFR-targeted therapies, which include selective, non-selective and covalent small-molecule inhibitors, as well as monoclonal antibodies against the receptors. We describe the expanding landscape of anti-FGFR therapies that are being assessed in early phase and randomised controlled clinical trials, such as erdafitinib and pemigatinib, which are approved by the Food and Drug Administration for the treatment of FGFR3-mutated urothelial carcinoma and FGFR2-fusion cholangiocarcinoma, respectively. However, despite initial sensitivity to FGFR inhibition, acquired drug resistance leading to cancer progression develops in most patients. This phenomenon underscores the need to clearly delineate tumour-intrinsic and tumour-extrinsic mechanisms of resistance to facilitate the development of second-generation FGFR inhibitors and novel treatment strategies beyond progression on targeted therapy.Subject terms: Cancer, Cancer  相似文献   
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