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   76500篇
  免费   8470篇
  国内免费   2862篇
耳鼻咽喉   828篇
儿科学   853篇
妇产科学   844篇
基础医学   6320篇
口腔科学   2589篇
临床医学   7820篇
内科学   9240篇
皮肤病学   612篇
神经病学   3430篇
特种医学   2346篇
外国民族医学   110篇
外科学   8397篇
综合类   18435篇
现状与发展   108篇
预防医学   7484篇
眼科学   1787篇
药学   7752篇
  96篇
中国医学   4000篇
肿瘤学   4781篇
  2024年   114篇
  2023年   1481篇
  2022年   2150篇
  2021年   3214篇
  2020年   3599篇
  2019年   1902篇
  2018年   2167篇
  2017年   1826篇
  2016年   2137篇
  2015年   2513篇
  2014年   5154篇
  2013年   4763篇
  2012年   6345篇
  2011年   6295篇
  2010年   4354篇
  2009年   4190篇
  2008年   3777篇
  2007年   5494篇
  2006年   4882篇
  2005年   3964篇
  2004年   3637篇
  2003年   2856篇
  2002年   2334篇
  2001年   1813篇
  2000年   1346篇
  1999年   1138篇
  1998年   798篇
  1997年   631篇
  1996年   432篇
  1995年   223篇
  1994年   353篇
  1993年   250篇
  1992年   366篇
  1991年   279篇
  1990年   229篇
  1989年   174篇
  1988年   154篇
  1987年   118篇
  1986年   88篇
  1985年   114篇
  1984年   76篇
  1983年   37篇
  1982年   37篇
  1981年   27篇
  1979年   1篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
1.
The purpose of this study was to investigate the association between habitual snoring (HS), middle ear disease (MED), and speech problems in children with cleft palate. This cross-sectional study included children aged 2.0–7.9 years with non-syndromic cleft palate anomalies. Parents completed the Pediatric Sleep Questionnaire and a questionnaire about MED. Audiograms and speech assessment were also conducted. Ninety-five children were enrolled; 15.2% of families reported HS, 97.6% MED, and 17.1% speech problems. HS (37.5% vs 10.3%, P = 0.007) and early episodes of MED (92.3% vs 58.2%, P = 0.021) were more likely to be reported for children with isolated cleft palate when compared to those with cleft lip and palate. Children with cleft lip and palate had a higher frequency of MED with effusion compared to those with Robin sequence (86.4% vs 57.1%, P = 0.049). The odds ratio for HS in children with ≥1 episode of MED in the last year was 7.37 (95% confidence interval 1.55–35.15, P = 0.012). There was a trend for children with speech problems reported by parents to have HS (30.8% vs 11.5%, P= 0.076). Anatomical factors play a role in the frequency of upper airway symptoms in children with cleft palate. A recent history of at least one episode of MED was associated with an increased frequency of HS.  相似文献   
2.
  1. Download : Download high-res image (173KB)
  2. Download : Download full-size image
  相似文献   
3.
4.
【目的】 在“中国科技期刊卓越行动计划”实施三周年之际,有必要对我国科技期刊2035年迈入“世界第一方阵”目标的具体任务进行重新审视和预判,以进一步明确发展方向,动态调整推进思路。【方法】 采用国内外科技期刊、科技论文、科技期刊评价成果的系统性发展数据对科技期刊“世界第一方阵” 国家(或地区)在高水平科技期刊数量与质量层面的入围标准进行界定,在深入总结现有基础和优势的同时,对我国科技期刊综合实力与“世界第一方阵”国家(或地区)的现实差距进行逐一梳理和剖析,并对实现目标的可行性和推进思路进行研判和设计。【结果】 必须继续加强高水平英文科技期刊创办和培育力度、持续加大优秀中文科技期刊的建设强度、快速推进国内外科技期刊论文等质同效评价制度的建设与引导,并积极探索建立科学家和科研机构办好一流科技期刊的责任制度和贡献激励机制、创新发展编辑人才队伍培养与激励管理思路、深入实践灵活多样的期刊出版市场资本运作模式、稳步推进期刊出版市场机制和管理制度改革,为我国科技期刊事业的高质量发展提速增效。【结论】 虽然当前阶段目标任务艰巨,但迈入“世界第一方阵”未来可期。  相似文献   
5.
Background and objective: Myocardial infarction (MI) is a common critical disease of the cardiovascular system. The process of MI is often accompanied by the excessive activation of cardiac sympathetic nerves, which leads to arrhythmia. Resiniferatoxin (RTX) is a transient receptor potential vanilloid 1 (TRPV1), involved in the cardiac sympathetic afferent reflex. However, whether RTX can reduce the occurrence of arrhythmia and exert a cardioprotective effect by inhibiting the sympathetic reflex during MI is still unknown. Methods: The left anterior descending artery of cardiac was clamped to construct a model of MI. RTX (50 μg/ml) was used by epicardial application in MI rats. Ventricular electrophysiologic properties were continuously monitored by a body surface ECG. Yrosine hydroxylase (TH) and growth associated protein 43 (GAP43) were detected by Immunofluorescence staining. Connexin43 and transforming growth factor beta receptor 1 (TGF-β1) were detected by western blot. Norepinephrine (NE) and BNP levels in blood and tissue were determined by ELISA. Cardiac function was assessed by echocardiography. Results: The ERP, APD90, QRS, QT and the Tend-Tpeak intervals in MI rats were all prolonged, but decreased after RTX treatment (n = 3, P<0.05). In contrast, the RR interval was shortened in the MI group, but prolonged in the MI+RTX group (n = 3, P<0.05). RTX treatment significantly reduced ventricular arrhythmias after MI. TH- and GAP43-positive nerve densities and TGF-β1, and cx-43 protein expression were up-regulated in the MI group compared to the sham group, and they were decreased in the MI+RTX group compared to the MI group (n = 3, P<0.05). RTX can decrease serum and tissue NE and BNP levels (n = 3, P<0.05). RTX pretreatment significantly decreased heart rate, HW/BW ratio and LVIDS, and increased LVEF andLVFS values (n = 3, P<0.05). Conclusion: RTX improved cardiac dysfunction, ventricular electrophysiologic properties, and sympathetic nerve remodeling in rats with MI by inhibiting the excessive cardiac sympathetic drive.  相似文献   
6.
BackgroundThe American Joint Committee on Cancer (AJCC) made improvements for staging pancreatic neuroendocrine tumors (pNETs) in its 8th Edition; however, multicenter studies were not included.MethodsWe collected multicenter datasets (n = 1,086, between 2004 and 2018) to validate the value of AJCC 8 and other coexisting staging systems through univariate and multivariate analysis for well-differentiated (G1/G2) pNETs.ResultsCompared to other coexisting staging systems, AJCC 7 only included 12 (1.1%) patients with stage III tumors. Patients with European Neuroendocrine Tumor Society (ENETS) stage IIB disease had a higher risk of death than patients with stage IIIA (hazard ratio [HR]: 4.376 vs. 4.322). For the modified ENETS staging system, patients with stage IIB disease had a higher risk of death than patients with stage III (HR: 6.078 vs. 5.341). According to AJCC 8, the proportions of patients with stage I, II, III, and IV were 25.7%, 40.3%, 23.6%, and 10.4%, respectively. As the stage advanced, the median survival time decreased (NA, 144.7, 100.8, 72.0 months, respectively), and the risk of death increased (HR: II = 3.145, III = 5.925, and IV = 8.762).ConclusionThese findings suggest that AJCC 8 had a more reasonable proportional distribution and the risk of death was better correlated with disease stage.  相似文献   
7.
8.
对当前的疾病预防控制体系和机构面临的体系不健全、政府投入不充分、事业发展不平衡、人才缺失和能力不足、缺乏系统的理论指导、体系的碎片化严重、与社会经济发展的战略衔接不力、机构内部内生动力和活力不足以及体系治理能力不足等问题做了讨论分析,以期进一步分析在健康中国战略和事业单位机构改革等宏观环境变化所带来的机遇以及疾控体系的发展策略和具体措施,促进疾病预防控制事业在改革中谋发展。  相似文献   
9.
ObjectiveTo clarify the associations between the IL-17A rs2275913 and IL-17F rs763780 polymorphisms and the risk of digestive system neoplasms.MethodsAn internet search was used to identify relevant articles from CNKI, Wanfang, VIP, PubMed, EMBASE and Elsevier up to December 2017. The meta-analysis was performed using Stata 11.0 software.ResultsTwenty-three studies were included. Among these, 21 studies with 6978 cases and 8000 controls were related to IL-17A rs2275913, while 18 studies that included 5073 cases and 6040 controls were related to IL-17F rs763780. The meta-analysis results demonstrated that the overall effects of the two polymorphisms were significantly different (P < 0.05) in the allele model, dominant model, recessive model and codominant model. Subgroup analysis showed that both polymorphisms were significantly associated with susceptibility to gastric cancer but not with hepatocellular carcinoma or colorectal cancer. In the ethnicity analysis, these two polymorphisms were associated with Asian populations but not with Caucasians. Similar results were observed in the hospital-based and population-based control subgroups.ConclusionsThe IL-17A rs2275913 and IL-17F rs763780 polymorphisms were associated with susceptibility to digestive system neoplasms.  相似文献   
10.
通过对大数据深度学习,近年人工智能技术已逐渐渗透到医学各个领域,实现一定程度应用。虽然耳鼻咽喉头颈外科专业近几年发表相关文献数量急剧增长,但大部分临床医生对于人工智能的研究还比较陌生。介绍人工智能的基本原理,列举、分析其在耳鼻喉科的主要研究情况,探讨目前人工智能技术实际应用的局限,展望未来人工智能技术在耳鼻喉科可能的应用。  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