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   156580篇
  免费   12534篇
  国内免费   5137篇
耳鼻咽喉   792篇
儿科学   2322篇
妇产科学   1412篇
基础医学   13951篇
口腔科学   2308篇
临床医学   15128篇
内科学   18483篇
皮肤病学   2535篇
神经病学   11895篇
特种医学   3598篇
外国民族医学   17篇
外科学   8289篇
综合类   23390篇
一般理论   4篇
预防医学   15361篇
眼科学   1796篇
药学   39311篇
  192篇
中国医学   6095篇
肿瘤学   7372篇
  2024年   151篇
  2023年   2485篇
  2022年   3271篇
  2021年   5489篇
  2020年   5921篇
  2019年   4942篇
  2018年   4781篇
  2017年   5108篇
  2016年   4981篇
  2015年   5055篇
  2014年   9822篇
  2013年   12878篇
  2012年   9681篇
  2011年   10429篇
  2010年   8400篇
  2009年   7722篇
  2008年   7792篇
  2007年   7811篇
  2006年   6948篇
  2005年   6367篇
  2004年   5308篇
  2003年   4840篇
  2002年   3856篇
  2001年   3522篇
  2000年   2925篇
  1999年   2517篇
  1998年   2225篇
  1997年   2064篇
  1996年   1708篇
  1995年   1815篇
  1994年   1636篇
  1993年   1347篇
  1992年   1324篇
  1991年   1176篇
  1990年   907篇
  1989年   748篇
  1988年   759篇
  1987年   727篇
  1986年   617篇
  1985年   759篇
  1984年   644篇
  1983年   446篇
  1982年   445篇
  1981年   396篇
  1980年   334篇
  1979年   239篇
  1978年   222篇
  1977年   201篇
  1976年   171篇
  1975年   91篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction.  相似文献   
2.
3.
4.
BackgroundAdverse drug reactions (ADRs) and adverse drug events (ADEs) in older people contribute to a significant proportion of hospital admissions and are common following discharge. Effective interventions are therefore required to combat the growing burden of preventable ADRs. The Prediction of Hospitalisation due to Adverse Drug Reactions in Elderly Community Dwelling Patients (PADR-EC) score is a validated risk score developed to assess the risk of ADRs in people aged 65 years and older and has the potential to be utilised as part of an intervention to reduce ADRs.ObjectivesThis trial was designed to investigate the effectiveness of an intervention to reduce ADR incidence in older people and to obtain further information about ADRs and ADEs in the 12–24 months following hospital discharge.MethodsThe study is an open-label randomised-controlled trial to be conducted at the Royal Hobart Hospital, a 500-bed public hospital in Tasmania, Australia. Community-dwelling patients aged 65 years and older with an unplanned overnight admission to a general medical ward will be recruited. Following admission, the PADR-EC ADR score will be calculated by a research pharmacist, with the risk communicated to clinicians and discussed with participants. Following discharge, nominated general practitioners and community pharmacists will receive the risk score and related medication management advice to guide their ongoing care of the patient. Follow-up with participants will occur at 3 and 12 and 18 and 24 months to identify ADRs and ADEs. The primary outcome is moderate-severe ADRs at 12 months post-discharge, and will be analysed using the cumulative incidence proportion, survival analysis and Poisson regression.SummaryIt is hypothesised that the trial will reduce ADRs and ADEs in the intervention population. The study will also provide valuable data on post-discharge ADRs and ADEs up to 24 months post-discharge.  相似文献   
5.
6.
7.
美国食品药品管理局(FDA)于2022年7月发布了"治疗等效性评价供企业用指导原则"(草案)。该指导原则阐明了FDA治疗等效性的标准以及治疗等效性编码系统,目的是准确评价仿制药与参比制剂的治疗等效性并通过治疗等效性代码,在"橙皮书"中迅速检索到治疗等效的仿制药。而中国目前尚无类似的指导原则,详细介绍FDA该指导原则主要内容,期望对中国加强仿制药的治疗等效性评价和加速完善和实施符合国情的治疗等效性编码系统有所帮助。  相似文献   
8.
BackgroundInflammation surrounding the coronary arteries can be non-invasively assessed using pericoronary adipose tissue attenuation (PCAT). While PCAT holds promise for further risk stratification of patients with low coronary artery disease (CAD) prevalence, its value in higher risk populations remains unknown.MethodsCORE320 enrolled patients referred for invasive coronary angiography with known or suspected CAD. Coronary computed tomography angiography (CCTA) images were collected for 381 patients for whom clinical outcomes were assessed 5 years after enrollment. Using semi-automated image analysis software, PCAT was obtained and normalized for the right coronary (RCA), left anterior descending (LAD), and left circumflex arteries (LCx). The association between PCAT and major adverse cardiovascular events (MACE) during follow up was assessed using Cox regression models.ResultsThirty-seven patients were excluded due to technical failure. For the remaining 344 patients, median age was 62 (interquartile range, 55–68) with 59% having ≥1 coronary artery stenosis of ≥50% by quantitative coronary angiography. Mean attenuation values for PCAT in RCA, LAD, and LCx were ?74.9, ?74.2, and ?71.2, respectively. Hazard ratios and 95% confidence intervals (CI) for normalized PCAT in the RCA, LAD, and LCx for MACE were 0.96 (CI: 0.75–1.22, p ?= ?0.71), 1.31 (95% CI: 0.96–1.78, p ?= ?0.09), and 0.98 (95% CI: 0.78–1.22, p ?= ?0.84), respectively. For death, stroke, or myocardial infarction only, hazard ratios were 0.68 (0.44–1.07), 0.85 (0.56–1.29), and 0.57 (0.41–0.80), respectively.ConclusionsIn patients referred for invasive coronary angiography with suspected CAD, PCAT did not predict MACE during long term follow up. Further studies are needed to understand the relationship of PCAT with CAD risk.  相似文献   
9.
10.
A delayed haemolytic transfusion reaction (DHTR) encompasses a positive direct antiglobulin test (DAT) developed anytime between 24 hours to 28 days after cessation of transfusion, a positive eluate or a newly identified alloantibody in the plasma or serum along with features of haemolysis in the patient. Routinely, it is expected that with the transfusion of one unit of packed red cells in a patient of average height and weight, the haemoglobin level and hematocrit increase by 1 g/dL and 3% respectively. However, in a patient with DHTR, an inadequate rise of post-transfusion haemoglobin (< 1 g/dL) or rapid fall in haemoglobin back to pre-transfusion levels is observed. Kidd antibodies are particularly known to cause DHTR, maybe alone or in unison with other antibodies. Detection of these alloantibodies is consequential in providing good transfusion support to these patients. These events may be difficult to detect as they may present as varied clinical features or immunological nuisances. In this case series, we have presented three cases of DHTR with special emphasis on their clinical presentations, immunohaematological evaluations, laboratory parameters and the role of proper transfusion support in these patients to avoid further complications.  相似文献   
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