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   4986篇
  免费   327篇
  国内免费   30篇
耳鼻咽喉   21篇
儿科学   226篇
妇产科学   203篇
基础医学   526篇
口腔科学   150篇
临床医学   553篇
内科学   919篇
皮肤病学   74篇
神经病学   259篇
特种医学   250篇
外科学   746篇
综合类   89篇
预防医学   360篇
眼科学   148篇
药学   311篇
中国医学   32篇
肿瘤学   476篇
  2023年   44篇
  2022年   49篇
  2021年   144篇
  2020年   87篇
  2019年   108篇
  2018年   139篇
  2017年   106篇
  2016年   98篇
  2015年   116篇
  2014年   169篇
  2013年   187篇
  2012年   336篇
  2011年   367篇
  2010年   200篇
  2009年   197篇
  2008年   264篇
  2007年   289篇
  2006年   279篇
  2005年   284篇
  2004年   232篇
  2003年   224篇
  2002年   229篇
  2001年   171篇
  2000年   142篇
  1999年   109篇
  1998年   45篇
  1997年   35篇
  1996年   39篇
  1995年   40篇
  1994年   25篇
  1993年   26篇
  1992年   57篇
  1991年   48篇
  1990年   43篇
  1989年   43篇
  1988年   50篇
  1987年   56篇
  1986年   56篇
  1985年   31篇
  1984年   22篇
  1983年   17篇
  1982年   16篇
  1981年   14篇
  1979年   16篇
  1978年   13篇
  1977年   11篇
  1976年   10篇
  1975年   7篇
  1973年   10篇
  1971年   7篇
排序方式: 共有5343条查询结果,搜索用时 31 毫秒
81.
82.
83.
84.
85.
86.
This study aims to compare the therapeutic effectiveness of continuous catheter drainage versus intermittent needle aspiration in the percutaneous treatment of pyogenic liver abscesses. Over a 5-year period, 64 consecutive patients with pyogenic liver abscess were treated with intravenous antibiotics (ampicillin, cefuroxime, and metronidazole) and randomized into two percutaneous treatment groups: continuous catheter drainage (with an 8F multi-sidehole pigtail catheter); and intermittent needle aspiration (18G disposable trocar needle). There was no statistically significant difference between the two groups regarding patient demographics, underlying coexisting disease, abscess size, abscess number, number of loculation of abscess, the presenting clinical symptoms such as fever, abdominal pain, and pretreatment liver function test. Although not statistically significant, the duration of intravenous antibiotics treatment before percutaneous treatment was longer with the catheter group, and the change of antibiotics after the sensitivity test was more frequent with the needle group. The needle group was associated with a higher treatment success rate, a shorter duration of hospital stay, and a lower mortality rate, although this did not reach statistical significance. In conclusion, this study suggests that intermittent needle aspiration is probably as effective as continuous catheter drainage for the treatment of pyogenic liver abscess, although further proof with a large-scale study is necessary. Due to the additional advantages of procedure simplicity, patient comfort, and reduced price, needle aspiration deserves to be considered as a first-line drainage approach.  相似文献   
87.
BACKGROUND: AND OBJECTIVES: The mitochondrial DNA A to G mutation at nucleotide 3243 (mt3243) is associated with a subtype of diabetes characterized by maternal transmission and deafness. We have previously reported a 2.7% prevalence of this mutation in a cohort of young patients with either type 1 or type 2 diabetes. In this study, we aimed to confirm this finding by examining for the prevalence of this mutation in a large-scale study. SUBJECTS AND METHODS: Nine hundred and six unrelated Chinese patients with type 2 diabetes and 213 nondiabetic controls were studied. The presence of mt3243 mutation was determined by polymerase chain reaction amplification and ApaI digestion. RESULTS: This mutation was found in four of 133 (3.0%) patients with early onset ( 40 years) diabetes and no family history. Basal pancreatic beta-cell function, as assessed by fasting plasma C-peptide, was variable amongst mutation carriers, and did not correlate with the level of heteroplasmy of mutation. CONCLUSIONS: In agreement with most studies, our results suggest that despite the high prevalence of positive maternal family history of diabetes amongst our type 2 diabetic patients, mt3243 mutation was not a major cause of diabetes in either early- or late-onset diabetic patients in Hong Kong. The role of other genetic, environmental and intrauterine factors needs further investigation.  相似文献   
88.
Introduction: Challenges remain in predicting mortality and severe myocardial dysfunction in patients undergoing primary percutaneous coronary intervention (PPCI) for ST elevation myocardial infarction (STEMI).

Areas covered: Cardiogenic shock is associated with a high mortality rate. Less well characterized are patients who are not in cardiogenic shock but will die from pump failure as a result of a STEMI. There is a long history of using hemodynamics to risk stratify patients with acute MI with the Killip class being shown to provide prognostic information in the prereperfusion, thrombolytic and PPCI eras. Recent studies have identified low systolic blood pressure (SBP), elevated heart rate, elevated left ventricular end diastolic pressure (LVEDP), and low SBP/LVEDP ratio as hemodynamic parameters associated with early mortality in patients undergoing PPCI. Although infrequently used, prognostic information can be obtained from right heart catheterization in the setting of STEMI with the best-studied parameters being cardiac power, pulmonary capillary wedge pressure (PCWP), cardiac output, right atrial pressure/PCWP ratio, and pulmonary artery pulsatility index.

Expert commentary: Hemodynamic parameters measured at the time of PPCI provide important prognostic information. Whether hemodynamics can be used to determine which patients benefit from early initiation of mechanical support remains to be determined.  相似文献   

89.
Identification of gene‐environment interaction (G × E) is important in understanding the etiology of complex diseases. Based on our previously developed Set Based gene EnviRonment InterAction test (SBERIA), in this paper we propose a powerful framework for enhanced set‐based G × E testing (eSBERIA). The major challenge of signal aggregation within a set is how to tell signals from noise. eSBERIA tackles this challenge by adaptively aggregating the interaction signals within a set weighted by the strength of the marginal and correlation screening signals. eSBERIA then combines the screening‐informed aggregate test with a variance component test to account for the residual signals. Additionally, we develop a case‐only extension for eSBERIA (coSBERIA) and an existing set‐based method, which boosts the power not only by exploiting the G‐E independence assumption but also by avoiding the need to specify main effects for a large number of variants in the set. Through extensive simulation, we show that coSBERIA and eSBERIA are considerably more powerful than existing methods within the case‐only and the case‐control method categories across a wide range of scenarios. We conduct a genome‐wide G × E search by applying our methods to Illumina HumanExome Beadchip data of 10,446 colorectal cancer cases and 10,191 controls and identify two novel interactions between nonsteroidal anti‐inflammatory drugs (NSAIDs) and MINK1 and PTCHD3.  相似文献   
90.
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