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   215081篇
  免费   17731篇
  国内免费   6863篇
耳鼻咽喉   1250篇
儿科学   7630篇
妇产科学   1542篇
基础医学   18969篇
口腔科学   3599篇
临床医学   22863篇
内科学   54495篇
皮肤病学   2721篇
神经病学   25709篇
特种医学   6223篇
外国民族医学   4篇
外科学   16468篇
综合类   29885篇
现状与发展   32篇
一般理论   9篇
预防医学   17075篇
眼科学   2332篇
药学   15025篇
  184篇
中国医学   9916篇
肿瘤学   3744篇
  2024年   223篇
  2023年   4345篇
  2022年   5834篇
  2021年   10874篇
  2020年   10965篇
  2019年   8332篇
  2018年   8250篇
  2017年   8196篇
  2016年   8516篇
  2015年   8224篇
  2014年   15582篇
  2013年   17067篇
  2012年   12757篇
  2011年   13792篇
  2010年   10850篇
  2009年   10441篇
  2008年   10448篇
  2007年   10104篇
  2006年   9006篇
  2005年   7426篇
  2004年   6319篇
  2003年   5425篇
  2002年   4573篇
  2001年   3950篇
  2000年   3270篇
  1999年   2719篇
  1998年   2442篇
  1997年   2093篇
  1996年   1862篇
  1995年   1926篇
  1994年   1778篇
  1993年   1513篇
  1992年   1453篇
  1991年   1280篇
  1990年   1011篇
  1989年   859篇
  1988年   807篇
  1987年   734篇
  1986年   633篇
  1985年   737篇
  1984年   617篇
  1983年   379篇
  1982年   446篇
  1981年   377篇
  1980年   283篇
  1979年   247篇
  1978年   185篇
  1977年   164篇
  1976年   136篇
  1975年   49篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Alveoli are the basic structure of the lungs, consisting of various types of parenchymal and bone marrow-derived cells including alveolar macrophages. These various types of cells have several important functions; thus, communication between these cells plays an important role in homeostasis as well as in the pathophysiology of diseases in the lungs. For a better understanding of the pathophysiology of lung diseases, researchers have isolated each type of lung cell to investigate the changes in their gene expressions, including their humoral factor or adhesion molecules, to reveal the intercellular communication among these cells. In particular, investigations during the past decade have focused on extracellular vesicles, which are lipid bilayer delimited vesicles released from a cell that can move among various cells and transfer substances, including microRNAs, mRNAs and proteins, thus, functioning as intercellular messengers. Extracellular vesicles can be classified into three general groups: apoptotic bodies, exosomes, and microparticles. Extracellular vesicles, especially exosomes and microparticles, are attracting increasing attention from pulmonologists as tools for understanding pathogenesis and disease diagnosis. Here, we review studies, including our own, on exosomes and microparticles and their roles in both lung homeostasis and the pathogenesis of lung diseases such as idiopathic pulmonary fibrosis, chronic obstructive lung diseases, and acute respiratory distress syndrome. This review also addresses the roles of extracellular vesicles in COVID-19, the current global public health crisis.  相似文献   
93.
《Indian heart journal》2021,73(5):549-554
ObjectiveRobotically assisted PCI offers a great alternative to S–PCI. This has gained even more relevance during the COVID-19 pandemic era however safety of R–PCI compared to S–PCI has not been studied well. This study explores the safety and efficacy of robotically assisted PCI (R–PCI) compared to standard PCI (S–PCI) for the treatment of coronary artery disease (CAD).MethodsPubMed, Scopus, Ovid, and Google scholar databases were searched for studies comparing R–PCI to S–PCI. Outcomes included clinical success, procedure time, fluoroscopy time, contrast use and radiation exposure.ResultsTheauthors included 5 studies comprising 1555 patients in this meta-analysis. Clinical success was comparable in both arms (p = 0.91). Procedure time was significantly longer in R–PCI group (risk ratio: 5.52, 95% confidence interval: 1.85 to 9.91, p = 0.003). Compared to S–PCI, patients in R–PCI group had lower contrast use (meandifference: −19.88, 95% confidence interval: −21.43 to −18.33, p < 0.001), fluoroscopy time (mean difference:-1.82, 95% confidence interval: −3.64 to −0.00, p = 0.05) and radiation exposure (mean difference:-457.8, 95% confidence interval: −707.14 to −208.14, p < 0.001).ConclusionR–PCI can achieve similar success as S–PCI at the expense of longer procedural times. However, radiation exposure and contrast exposure were lower in the R–PCI arm.  相似文献   
94.
95.
目的探析慢性阻塞性肺疾病合并侵袭性肺曲霉菌病患者的临床特点。方法对医院2018年2月—2019年12月间收治的慢性阻塞性肺疾病合并侵袭性肺曲霉菌病患者24例相关临床数据进行回顾性分析,归纳此类患者的临床特点,以期为以后收治此类患者在诊疗上提供可参考数据。结果慢性阻塞性肺疾病合并侵袭性肺曲霉菌病患者典型临床症状为肺部罗音、呼吸障碍、胸痛、咳嗽咳痰、发热。影像学检查后典型表现为肺部炎性渗出、空洞、结节、实变。经过积极治疗后有8例患者判定为治疗有效。结论收治慢性阻塞性肺疾病合并侵袭性肺曲霉菌病患者应该做到早期阶段准确诊断,积极治疗,是保障预后的重点。  相似文献   
96.
胆囊切除术是公认的胆囊良性疾病的治愈手段,国内外学术界对于手术适应证和手术时机已有明确共识。近年来,“保胆手术”治疗胆囊良性疾病颇受热议,一些医生将“保护胆囊”的学术观点等同于“保留胆囊”的手术技术,这种误解可能导致病人出现差异性的预后。因此,临床医师应明晰“保护胆囊”理念与“保胆手术”的差别,对胆囊良性疾病的诊疗原则有正确的理解和应用。  相似文献   
97.
BackgroundSeizures and subclinical epileptiform activity are common yet easily overlooked among demented patients. We aimed to investigate their epidemiological characteristics in patients with dementia from various aspects.MethodsWe retrieved relevant observational studies from PubMed and Embase Library until March 2021. Pooled estimate effects were calculated using random-effects models. This study is registered with PROSPERO, number CRD42020200949.ResultsOf the 19144 identified studies, 27 were eligible for inclusion. The pooled period prevalence rates of seizures were 4.86% (95%CI: 3.43–6.51%), 2.68% (95%CI: 2.13–3.28%), 2.81% (95%CI: 2.02–3.71%)and 7.13% (95%CI: 2.67–13.14%) among patients with Alzheimer’s disease (AD), Dementia of Lewy Body (DLB), Frontotemporal dementia (FTD) and Vascular dementia (VaD), respectively. The pooled incidence rate of seizures was [8.4 (95%CI: 4.2–12.7) per 1000 person-years] in AD patients. And the pooled relative risk of seizures in patients with AD was 3.35 (95%CI: 2.69–4.19). Besides, the pooled cumulative incidence rate and prevalence rate of subclinical epileptiform activity among AD patients were [21.41% (95%CI: 0.001–63.60%)] and 9.73% (95%CI: 0.26–28.38%), respectively.ConclusionsThe accurate rates of seizures and subclinical epileptiform activities in the four major dementia types are high. Besides, patients with AD are likely at a higher risk of seizures.  相似文献   
98.
本文通过对特发性肺纤维化急性发作病因病机的分析,认为其病因为外邪或内伤引动肺络虚火,从阳化热,病机为“肺热”、“络瘀”;并结合其病因病机,探究归纳《温病条辨》中清络法和中药复方清络饮在论治特发性肺纤维化急性发作时的理论基础,为临床中论治特发性肺纤维化急性发作,改善患者症状提供新方法,为肺络病证治体系构建及应用提供新思路。  相似文献   
99.
100.
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