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   15174篇
  免费   703篇
  国内免费   238篇
耳鼻咽喉   18篇
儿科学   309篇
妇产科学   197篇
基础医学   1251篇
口腔科学   88篇
临床医学   1586篇
内科学   5727篇
皮肤病学   61篇
神经病学   633篇
特种医学   307篇
外科学   1570篇
综合类   1325篇
一般理论   1篇
预防医学   1706篇
眼科学   26篇
药学   991篇
  20篇
中国医学   182篇
肿瘤学   117篇
  2023年   339篇
  2022年   563篇
  2021年   953篇
  2020年   669篇
  2019年   882篇
  2018年   931篇
  2017年   632篇
  2016年   500篇
  2015年   535篇
  2014年   1228篇
  2013年   1139篇
  2012年   674篇
  2011年   820篇
  2010年   578篇
  2009年   601篇
  2008年   650篇
  2007年   516篇
  2006年   406篇
  2005年   382篇
  2004年   301篇
  2003年   246篇
  2002年   208篇
  2001年   171篇
  2000年   138篇
  1999年   110篇
  1998年   77篇
  1997年   82篇
  1996年   64篇
  1995年   67篇
  1994年   72篇
  1993年   71篇
  1992年   47篇
  1991年   47篇
  1990年   41篇
  1989年   50篇
  1988年   47篇
  1987年   35篇
  1985年   85篇
  1984年   137篇
  1983年   120篇
  1982年   102篇
  1981年   125篇
  1980年   88篇
  1979年   100篇
  1978年   91篇
  1977年   76篇
  1976年   78篇
  1975年   78篇
  1974年   57篇
  1973年   51篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.

Background

It has been reported that particulate matter (PM) is associated with cardiovascular diseases (CVD) while metabolic syndrome is also an important risk factor for CVD. However, few studies have investigated the epidemiological association between PM and metabolic syndrome.

Objective

To investigate the association between one-year exposure to PM with an aerodynamic diameter <2.5?μm (PM2.5) and the risk of metabolic syndrome in Korean adults without CVD.

Methods

Exposure to PM2.5 was assessed using a Community Multiscale Air Quality (CMAQ) model. Metabolic syndrome was defined by National Cholesterol Education Program Adult Treatment Panel III. Andersen and Gill model with time-varying covariates, considering recurrent events, was used to investigate the association between one-year average PM2.5 and the risk of incident metabolic syndrome in 119,998 adults from the national health screening cohort provided by Korea National Health Insurance from 2009 to 2013.

Results

Higher risk of metabolic syndrome, waist-based obesity, hypertension, hypertriglyceridemia, low HDL cholesterol, and hyperglycemia were significantly associated with a 10-μg/m3 increase in PM2.5 [adjusted hazard ratio (HR): 1.070, 1.510, 1.499, 1.468, 1.627 and 1.380, respectively]. In addition, the risk of metabolic syndrome associated with PM2.5 exposure was significant in the consistently obese group (obese at baseline and endpoint).

Conclusion

Exposure to one-year average PM2.5 is associated with an increased risk of metabolic syndrome and its components in adults without CVD. These associations are particularly prominent in the consistently obese group (obese at baseline and endpoint). Our findings indicate that PM2.5 affects the onset of MS and its components which may lead to increase the risk of CVD.  相似文献   
3.
4.
5.
6.
ObjectiveHospitalization-associated disability [HAD, ie, the loss of ability to perform ≥1 basic activities of daily living (ADLs) independently at discharge] is a frequent condition among older patients. The present study assessed whether a simple inpatient exercise program decreases HAD incidence in acutely hospitalized very old patients.DesignIn this randomized controlled trial (Activity in Geriatric Acute Care) participants were assigned to a control or intervention group and were assessed at baseline, admission, discharge, and 3 months thereafter.Setting and ParticipantsIn total, 268 patients (mean age 88 years, range 75–102) admitted to an acute care for older patients unit of a public hospital were randomized to a control (n = 125) or intervention (exercise) group (n = 143).MethodsBoth groups received usual care, and patients in the intervention group also performed simple supervised exercises (walking and rising from a chair, for a total duration of ∼20 minutes/day). We measured ADL function (Katz index) and incident HAD at discharge and after 3 months (primary outcome) and Short Physical Performance Battery, ambulatory capacity, number of falls, rehospitalization, and death during a 3-month follow-up (secondary outcomes).ResultsMedian duration of hospitalization was 7 days (interquartile range 4 days). The intervention group had a lower risk of HAD with reference to both baseline [odds ratio (OR) 0.36; 95% confidence interval (CI) 0.17–0.76, P = .007] and admission (OR 0.29; 95% CI 0.10–0.89, P = .030). A trend toward an improved ADL function at discharge vs admission was found in the intervention group compared with controls (OR 0.32; 95% CI ‒0.04 to 0.68; P = .083). No between-group differences were noted for the other endpoints (all P > .05).Conclusion and ImplicationsA simple inpatient exercise program decreases risk of HAD in acutely hospitalized, very old patients.  相似文献   
7.
《Australian critical care》2019,32(6):540-559
ObjectivesThe objective of this review was to describe cardiovascular risk (CVR) assessment methods and to identify evidence-based practice recommendations when dealing with population at risk of developing cardiovascular diseases.Review methods and data sourcesA literature review following the Arksey and O'Malley scoping review methodology was conducted. By using appropriate key terms, literature searches were conducted in PubMed, SciELO, Cochrane Library, Dialnet, ENFISPO, Medigraphic, ScienceDirect, Cuiden, and Lilacs databases. A complementary search on websites related to the area of interest was conducted. Articles published in English or Spanish in peer-review journals between 2010 and 2017. Critical appraisal for methodological quality was conducted. Data was extracted using ad-hoc tables and qualitatively synthesized.ResultsAfter eliminating duplicates, 55 325 records remained, and 1432 records were selected for screening. Out of these, 88 full-text articles were selected for eligibility criteria, and finally, 67 studies were selected for this review, and 25 studies were selected for evidence synthesis. In total, 23 CVR assessment tools have been identified, pioneered by the Framingham study. Qualitative findings were grouped into four thematic areas: assessment tools and scores, CVR indicators, comparative models, and evidence-based recommendations.ConclusionsIt is necessary to adapt the instruments to the epidemiological reality of the population. The most appropriate way to estimate CVR is to choose the assessment tool that best suits individual conditions, accompanied by a comprehensive assessment of the patient. More research is required to determine a single, adequate, and reliable tool.  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