全文获取类型
收费全文 | 2478539篇 |
免费 | 176604篇 |
国内免费 | 5561篇 |
专业分类
耳鼻咽喉 | 33639篇 |
儿科学 | 80927篇 |
妇产科学 | 67929篇 |
基础医学 | 352316篇 |
口腔科学 | 71380篇 |
临床医学 | 215246篇 |
内科学 | 489772篇 |
皮肤病学 | 55845篇 |
神经病学 | 194579篇 |
特种医学 | 93897篇 |
外国民族医学 | 563篇 |
外科学 | 374802篇 |
综合类 | 54346篇 |
现状与发展 | 4篇 |
一般理论 | 773篇 |
预防医学 | 189424篇 |
眼科学 | 59388篇 |
药学 | 181092篇 |
7篇 | |
中国医学 | 6083篇 |
肿瘤学 | 138692篇 |
出版年
2019年 | 19929篇 |
2018年 | 29415篇 |
2017年 | 22135篇 |
2016年 | 23987篇 |
2015年 | 27222篇 |
2014年 | 37526篇 |
2013年 | 55830篇 |
2012年 | 78119篇 |
2011年 | 82626篇 |
2010年 | 48552篇 |
2009年 | 44872篇 |
2008年 | 76522篇 |
2007年 | 81500篇 |
2006年 | 81818篇 |
2005年 | 78668篇 |
2004年 | 75603篇 |
2003年 | 72153篇 |
2002年 | 70056篇 |
2001年 | 121574篇 |
2000年 | 124860篇 |
1999年 | 103802篇 |
1998年 | 27582篇 |
1997年 | 24308篇 |
1996年 | 24353篇 |
1995年 | 23165篇 |
1994年 | 21480篇 |
1993年 | 19887篇 |
1992年 | 78981篇 |
1991年 | 75986篇 |
1990年 | 73507篇 |
1989年 | 70650篇 |
1988年 | 64825篇 |
1987年 | 63330篇 |
1986年 | 60172篇 |
1985年 | 57054篇 |
1984年 | 42256篇 |
1983年 | 35919篇 |
1982年 | 20648篇 |
1979年 | 38088篇 |
1978年 | 26380篇 |
1977年 | 22502篇 |
1976年 | 20993篇 |
1975年 | 22624篇 |
1974年 | 27344篇 |
1973年 | 26366篇 |
1972年 | 24627篇 |
1971年 | 22858篇 |
1970年 | 21491篇 |
1969年 | 20234篇 |
1968年 | 19053篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
Widder Randolf A. Lappas Alexandra Rennings Corinna Hild Matthias Roessler Gernot F. Dietlein Thomas S. 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2020,258(11):2581-2581
Graefe's Archive for Clinical and Experimental Ophthalmology - The published online version contains mistake as the author's first name and last name have been interchanged as "Hild... 相似文献
34.
35.
Philip S. Vendittelli Bassent Botros Howard S. Rosman Viren Govindaraju Anwar Zaitoun Tariq S. Marroush 《The American journal of the medical sciences》2019,357(4):333-337
Coronary embolism (CE) is an uncommon and unique cause of acute myocardial infarction. In this report, we review 216 cases of CE including 2 new cases from our institution. The mean patient age was 52.5 years and 62% of the patients were males. Chest pain was the most common presenting symptom followed by dyspnea, and the most commonly affected vessel was the left anterior descending artery. Leading etiologies of the embolus were atrial fibrillation, septic emboli, and iatrogenic causes. Treatment approaches varied with thrombus aspiration being used in 30% of cases. In-hospital mortality rate was 36% and 13% of the cases were complicated by cerebrovascular accident. CE is a unique pathology that leads to acute myocardial infarction. It portends a high mortality rate and requires a high level of suspicion as symptoms may be misleading. Further research is needed in order to improve recognition and management and to lower associated mortality. 相似文献
36.
Krishna S. Iyer 《Platelets》2020,31(4):474-482
Abstract Platelets are small, anucleated effector cells that play an important role in linking the hemostatic and inflammatory processes in the body. Platelet function is known to be altered under various inflammatory conditions including aging. A gain in platelet function during aging can increase the risk of thrombotic events, such as stroke and acute myocardial infarction. Anti-platelet therapy is designed to reduce risk of serious cerebrovascular and cardiovascular events, but the adverse consequences of therapy, such as risk for bleeding increases with aging as well. Age-associated comorbidities such as obesity, diabetes, and hyperlipidemia also contribute to increased platelet activity and thus can enhance the risk of thrombosis. Therefore, identification of unique mechanisms of platelet dysfunction in aging and in age-associated comorbidities is warranted to design novel antiplatelet drugs. This review outlines some of the current areas of research on aging-related mechanisms of platelet hyperactivity and addresses the clinical urgency for designing anti-platelet therapies toward novel molecular targets in the aging population. 相似文献
37.
38.
39.
Timo Rath Lukas Pfeifer Clemens Neufert reas Kremer Moritz Leppkes Arthur Hoffman Markus F Neurath Steffen Zopf 《World journal of gastroenterology : WJG》2020,26(16):1962-1970
BACKGROUND The adenoma detection rate(ADR) is inversely associated with the incidence of interval colorectal cancer and serves as a benchmark quality criterion during screening colonoscopy. However, adenoma miss rates reach up to 26% and studies have shown that a second inspection of the right colon in retroflected view(RFV) can increase ADR.AIM To assess whether inspection of the whole colon in RFV compared to standard forward view(SFV) can increase ADR.METHODS Patients presenting for screening or surveillance colonoscopy were invited to participate in this randomized controlled trial and randomized into two arms. In RFV arm colonoscopy was initially performed with SFV, followed by a second inspection of the whole colon in RFV. In the SFV arm first withdrawal was performed with SFV, followed by a second inspection of the whole colon again with SFV. Number, size and morphology of polyps found during first and second inspection in each colonic segment were recorded and all polyps were removed and sent for histopathology in separate containers.RESULTS Two hundred and five patients were randomly assigned to the RFV(n = 101) and SFV(n = 104) arm. In the RFV arm, both polyp detection rate(PDR) and ADR were increased under second inspection in RFV(PDR 1~(st) SFV: 39.8%, PDR 2~(nd)RFV: 46.6%; ADR 1~(st) SFV: 35.2%, ADR 2~(nd) RFV: 42%). Likewise, in the SFV arm,PDR and ADR were increased under second inspection(PDR 1~(st) SFV: 37.5%, PDR 2~(nd) SFV: 46.6%; ADR 1~(st) SFV: 34.1%, ADR 2~(nd)SFV: 44.3%) with no significant differences in ADR and PDR between the SFV and RFV arm. Mean number of adenomas per patient(APP) was increased in the RFV and SFV(APP RFV arm: 1~(st) SFV: 1.71; 2~(nd) RFV: 2.38; APP SFV arm: 1~(st) SFV: 1.83, 2~(nd)SFV:2.2). The majority of adenomas additionally found during second inspection in RFV or in SFV were located in the transverse and left-sided colon and were 5 mm in size.CONCLUSION Second inspection of the whole colon leads to increased adenoma detection with no differences between SFV and RFV. Hence, increased detection is most likely a feature of the second inspection itself but not of the inspection mode. 相似文献
40.
Mohid S Khan Thomas Walter Amy Buchanan-Hughes Emma Worthington Lucie Keeber Marion Feuilly Enrique Grande 《World journal of gastroenterology : WJG》2020,26(30):4537-4556
BACKGROUND Approximately 20% of patients with neuroendocrine tumours(NETs) develop carcinoid syndrome(CS),characterised by flushing and diarrhoea.Somatostatin analogues or telotristat can be used to control symptoms of CS through inhibition of serotonin secretion.Although CS is often the cause of diarrhoea among patients with gastroenteropancreatic NETs(GEP-NETs),other causes to consider include pancreatic enzyme insufficiency(PEI),bile acid malabsorption and small intestinal bacterial overgrowth.If other causes of diarrhoea unrelated to serotonin secretion are mistaken for CS diarrhoea,these treatments may be ineffective against the diarrhoea,risking detrimental effects to patient quality of life.AIM To identify and synthesise qualitative and quantitative evidence relating to the differential diagnosis of diarrhoea in patients with GEP-NETs.METHODS Electronic databases(MEDLINE,Embase and the Cochrane Library) were searched from inception to September 12,2018 using terms for NETs and diarrhoea.Congresses,systematic literature review bibliographies and included articles were also hand-searched.Any study designs and publication types were eligible for inclusion if relevant data on a cause(s) of diarrhoea in patients with GEP-NETs were reported.Studies were screened by two independent reviewers at abstract and full-text stages.Framework synthesis was adapted to synthesise quantitative and qualitative data.The definition of qualitative data was expanded to include all textual data in any section of relevant publications.RESULTS Forty-seven publications(44 studies) were included,comprising a variety of publication types,including observational studies,reviews,guidelines,case reports,interventional studies,and opinion pieces.Most reported on PEI on/after treatment with somatostatin analogs;9.5%-84% of patients with GEP-NETs had experienced steatorrhoea or confirmed PEI.Where reported,14.3%–50.7% of patients received pancreatic enzyme replacement therapy.Other causes of diarrhoea reported in patients with GEP-NETs included bile acid malabsorption(80%),small intestinal bacterial overgrowth(23.6%-62%),colitis(20%) and infection(7.1%).Diagnostic approaches included faecal elastase,breath tests,tauroselcholic(selenium-75) acid(Se HCAT) scan and stool culture,although evidence on the effectiveness or diagnostic accuracy of these approaches was limited.Assessment of patient history or diarrhoea characteristics was also reported as initial approaches for investigation.From the identified evidence,if diarrhoea is assumed to be CS diarrhoea,consequences include uncontrolled diarrhoea,malnutrition,and perceived ineffectiveness of CS treatment.Approaches for facilitating differential diagnosis of diarrhoea include improving patient and clinician awareness of non-CS causes and involvement of a multidisciplinary clinical team,including gastroenterologists.CONCLUSION Diarrhoea in GEP-NETs can be multifactorial with misdiagnosis leading to delayed patient recovery and inefficient resource use.This systematic literature review highlights gaps for further research on prevalence of non-CS diarrhoea and suitability of diagnostic approaches,to determine an effective algorithm for differential diagnosis of GEP-NET diarrhoea. 相似文献