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   52521篇
  免费   2621篇
  国内免费   259篇
耳鼻咽喉   186篇
儿科学   1227篇
妇产科学   682篇
基础医学   3055篇
口腔科学   858篇
临床医学   6583篇
内科学   6495篇
皮肤病学   489篇
神经病学   2010篇
特种医学   619篇
外科学   3039篇
综合类   6108篇
现状与发展   1篇
一般理论   4篇
预防医学   19183篇
眼科学   351篇
药学   2768篇
  27篇
中国医学   741篇
肿瘤学   975篇
  2024年   40篇
  2023年   985篇
  2022年   1785篇
  2021年   2419篇
  2020年   2389篇
  2019年   3436篇
  2018年   2928篇
  2017年   1964篇
  2016年   1364篇
  2015年   1592篇
  2014年   3849篇
  2013年   3601篇
  2012年   3422篇
  2011年   3715篇
  2010年   2838篇
  2009年   2567篇
  2008年   2424篇
  2007年   2309篇
  2006年   1776篇
  2005年   1170篇
  2004年   965篇
  2003年   779篇
  2002年   599篇
  2001年   547篇
  2000年   442篇
  1999年   389篇
  1998年   304篇
  1997年   214篇
  1996年   133篇
  1995年   154篇
  1994年   123篇
  1993年   102篇
  1992年   90篇
  1991年   54篇
  1990年   43篇
  1989年   30篇
  1988年   33篇
  1985年   333篇
  1984年   479篇
  1983年   392篇
  1982年   402篇
  1981年   405篇
  1980年   323篇
  1979年   312篇
  1978年   281篇
  1977年   211篇
  1976年   185篇
  1975年   176篇
  1974年   149篇
  1973年   129篇
排序方式: 共有10000条查询结果,搜索用时 23 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.
BackgroundPolypharmacy is commonly related to poor drug adherence, decreased quality of life and inappropriate prescribing in eldery. Furthermore, this condition also leads to a higher utilization of health services resources, due to the increased risk of adverse drug events, length of stays in hospitals and readmissions rates after discharge.ObjectiveThis Systematic Review aimed to synthesize the current evidence that evaluates pharmaceutical services on polymedicated patients, from an economic perspective.MethodsSystematic searches were conducted in MEDLINE, SCOPUS and Cochrane Library databases to identify studies that were published until January 2021. Experimental and observational studies were included in this review, using strict inclusion/exclusion criteria and were assessed for quality using the following tools: RoB and ROBINS-I. Two independent reviewers selected the articles and extracted the data.Results3,662 articles were retrieved from the databases. After the screening, 18 studies were included: 9 experimental and 9 observational studies. The studies reported that the integration of the pharmacist as a member of the healthcare team provides an optimized use of pharmacotherapy to polymedicated patients and contributes to health promotion, providing reduction of spending on medication, reduction of expenses related to emergency care and hospitalizations and other medical expenses. The ECRs made cost-effectiveness or cost-benefit analysis, and most of the Non Randomized studies had statistically significant cost savings even considering the expenses of pharmaceutical assistance. Experimental studies reported a cost reduction varying between US$ 193 to US$ 4,966 per patient per year. Furthermore, observational studies estimated a cost reduction of varying from US$ 3 to US$ 2,505 per patient per year. The cost savings are related to decrease in emergency visits and hospitalizations, through pharmacist intervention (medication review and pharmacotherapy follow-up).ConclusionsConsidering the set of studies included, pharmaceutical care services directed to polymedicated patients may cooperate to save financial resources. Most of the interventions showed positive economic trends and also contributed to improving clinical parameters and quality of life. However, due to the majority of the studies having exploratory or qualitative methodology, it is essential to carry out more robust studies, based on full economic evaluation.  相似文献   
3.
4.
BackgroundThe Coronavirus Disease 2019 pandemic provided a natural experiment to study the effect of social distancing on the risk of developing Hirschsprung's Associated Enterocolitis (HAEC).MethodsUsing the Pediatric Health Information System (PHIS), a retrospective cohort study of children (<18 years) with Hirschsprung's Disease (HSCR) across 47 United States children's hospitals was performed. The primary outcome was HAEC admissions per 10,000 patient-days. The exposure (COVID-19) was defined as April 2020–December 2021. The unexposed (historical control) period was April 2018–December 2019. Secondary outcomes included sepsis, bowel perforation, intensive care unit (ICU) admission, mortality, and length of stay.ResultsOverall, we included 5707 patients with HSCR during the study period. There were 984 and 834 HAEC admissions during the pre-pandemic and pandemic periods, respectively (2.6 vs. 1.9 HAEC admissions per 10,000 patient-days, incident rate ratio [95% confidence interval]: 0.74 [0.67, 0.81], p < 0.001). Compared to pre-pandemic, those with HAEC during the pandemic were younger (median [IQR]: 566 [162, 1430] days pandemic vs. 746 [259, 1609] days pre-pandemic, p < 0.001) and more likely to live in the lowest quartile of median household income zip codes (24% pandemic vs. 19% pre-pandemic, p = 0.02). There were no significant differences in rates of sepsis (6.1% pandemic vs. 6.1% pre-pandemic, p > 0.9), bowel perforation (1.3% pandemic vs. 1.2% pre-pandemic, p = 0.8), ICU admissions (9.6% pandemic vs. 12% pre-pandemic, p = 0.2), mortality (0.5% pandemic vs. 0.6% pre-pandemic, p = 0.8), or length of stay (median [interquartile range]: 4 [(Pastor et al., 2009; Gosain and Brinkman, 2015) 2,112,11 days pandemic vs. 5 [(Pastor et al., 2009; Tang et al., 2020) 2,102,10 days pre-pandemic, p = 0.4).ConclusionsThe COVID-19 pandemic was associated with significantly decreased incidence of HAEC admissions across US children's hospitals. Possible etiologies such as social distancing should be explored.Level of evidenceII.  相似文献   
5.
Background & aimsTo determine the trends of self-reported non-adherence rates among adults taking Type 2 medicines (T2D) medicines between 2017 and 2019 and to identify the patterns for the frequently reported reasons for non-adherence in the United States.Methods & resultsData from the National Health and Wellness Survey, a self-administered, internet-based cross-sectional survey of US adults from 2017 to 2019 was used. Non-adherence was measured using the self-reported Medication Adherence Reasons Scale (MAR-Scale). Frequencies were used to identify the reasons for non-adherence for insulin and non-insulin therapies for T2D.Data were obtained from 2983 respondents in 2017, 5416 in 2018, and 5268 in 2019. Based on the MAR-Scale, the self-reported medication non-adherence rate was 25% in 2017, 21% in 2018, and 27% in 2019. The most common reason for non-adherence across all the three years was simple forgetfulness, yet patients reported the lowest mean number of days missing medication for that reason. Though less frequently reported, non-adherence lasted longer when patient did not know how to take their medicines, cost was a reason, or had concerns about the long term effects of the medicines.ConclusionsWith no significant improvement in adherence with T2D medicines over time, regardless of better awareness and extensive diabetes education, focus should be on individualized non-adherence reasons-based interventions.  相似文献   
6.
7.
目的 围绕足三里穴(ST36)进行文献可视化分析,探索近20年来有关足三里穴的研究进程、热点以及未来发展趋势。方法 以中国知网(CNKI)为数据来源,利用citespace软件对检索出的2000年1月至2021年11月收录的基础研究和临床研究文献分别进行可视化分析,绘制关键词、作者、机构相关图谱。结果 基础研究纳入1030篇文献,得到9个关键词聚类,电针中心度最高(0.53),发文量最多的作者是胡森(22篇),发文量最大的机构是北京中医药大学针灸推拿学院(23篇)。临床研究纳入2067篇文献,得到9个关键词聚类,穴位注射和针刺中心度最高(0.27),发文量最多的作者是张波(7篇),发文量最大的机构是浙江中医药大学附属第一医院(8篇)。结论 足三里穴在基础和临床的研究重点、热点和趋势不一致。并且在基础研究和临床研究之间,针刺镇痛、电针疗法、胃肠功能这三个内容是同步的,而关于代谢组学、穴位注射、温针灸和揿针的内容则是脱节的。  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