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   15269篇
  免费   799篇
  国内免费   71篇
耳鼻咽喉   80篇
儿科学   382篇
妇产科学   309篇
基础医学   1277篇
口腔科学   250篇
临床医学   2739篇
内科学   2383篇
皮肤病学   179篇
神经病学   687篇
特种医学   247篇
外科学   1105篇
综合类   1296篇
预防医学   2242篇
眼科学   172篇
药学   1303篇
  5篇
中国医学   958篇
肿瘤学   525篇
  2024年   48篇
  2023年   431篇
  2022年   777篇
  2021年   894篇
  2020年   782篇
  2019年   1500篇
  2018年   1099篇
  2017年   696篇
  2016年   392篇
  2015年   345篇
  2014年   1007篇
  2013年   913篇
  2012年   724篇
  2011年   795篇
  2010年   569篇
  2009年   575篇
  2008年   478篇
  2007年   413篇
  2006年   289篇
  2005年   217篇
  2004年   146篇
  2003年   114篇
  2002年   74篇
  2001年   87篇
  2000年   64篇
  1999年   45篇
  1998年   33篇
  1997年   24篇
  1996年   23篇
  1995年   27篇
  1994年   17篇
  1993年   9篇
  1991年   7篇
  1989年   12篇
  1988年   8篇
  1987年   6篇
  1986年   6篇
  1985年   204篇
  1984年   296篇
  1983年   268篇
  1982年   263篇
  1981年   258篇
  1980年   200篇
  1979年   197篇
  1978年   140篇
  1977年   146篇
  1976年   170篇
  1975年   140篇
  1974年   101篇
  1973年   98篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Rehabilitation is under-represented in the neurological literature on disabling diseases. A Medline search was conducted to retrieve the articles published between January 1991 and June 1994 under the main headings of Stroke, Parkinson's disease, Multiple sclerosis, Brain injury, Ataxia and Dementia. These were then combined with the sub-heading Rehabilitation. The former search yielded 27724 articles, the latter 1272 (4.6%). In 1992, the Journal of Citation Reports (JCR) assigned to Journals publishing rehabilitation papers an average Impact Factor (IF) of 0.7–2.8 (median 1.8): that is, 31–90% (depending on the various main headings, median 68%) of the average IF given to Journals publishing non-rehabilitation papers. In the present study, the weight of the literature was defined as the product of the number of articles multiplied by the IF of the corresponding Journal (IF=0 for non-JCR Journals). Across the various neurologic conditions, the weight of the Rehab literature was 0.1–7% (median 2%) of the weight of the non-Rehab literature. The results suggest that neurology is still reluctant to face the disability challenge.
Sommario La riabilitazione è scarsamente rappresentata nella letteratura neurologica sulle patologie che causano disabilità. Gli Autori hanno interrogato la banca-dati Medline nella ricerca degli articoli pubblicati fra il Gennaio 1991 ed il Giugno 1994 sotto le parole-chiave Stroke, Parkinson's disease, Multiple Sclerosis, Brain injury, Ataxia e Dementia. È stato poi eseguito un incrocio con la parola-chiave secondaria Riabilitazione.La prima ricerca ha prodotto 27724 articoli mentre la seconda ne ha prodotti 1272 (4.6%). Nel 1992 il Journal of Citation Reports (JCR) ha attribuito alle Riviste che hanno pubblicato articoli con tema riabilitativo un Impact Factor (IF) medio di 0.7–2.8 (mediana 1.8), pari al 31–90% (a seconda della parola-chiave principale: mediana delle percentuali 68%) dell'IF medio attribuito alle Riviste che hanno pubblicato soltanto articoli su temi non riabilitativi. In questo studio è stato definito come peso della letteratura il prodotto del numero di articoli per l'IF delle rispettive Riviste (IF=0 per le Riviste non censite dal JCR). A seconda delle diverse patologie neurologiche, il peso della letteratura riabilitativa variava fra 0.1 e 7% (mediana 2%) del peso della letteratura non riabilitativa.I risultati suggeriscono che la Neurologia sia ancora riluttante ad affrontare la sfida che le pone la disabilità.
  相似文献   
62.
槐耳的研制及临床应用   总被引:4,自引:0,他引:4  
槐耳是一种人药1500余年但已湮没300余年的重要药用真菌。它和其原料药材槐耳菌质近年来已被批准为中药国家一类新药,就有关槐耳的研制及其在肿瘤疾病方面的应用作一综述。  相似文献   
63.
The present paper reports on the inaugural meeting of the Mental Health Special Interest Research Group (SIRG) of the International Association for the Scientific study of Intellectual disability which was held at Fitzwilliam College, Cambridge, UK, in March 1998. The meeting was organized in conjunction with the Ninth Annual SIRG on ageing and intellectual disability. Representatives from North America, several European and Scandinavian countries, Australia, and Israel attended. Two broad themes had been determined prior to the meeting: ‘Improving the detection of mental health problems’ and ‘Research strategies for identifying risk factors for mental health problems’. In the presentations and subsequent discussions, it was apparent that there were extrenely diverse perspectives both across and within the different countries represented. Not only were individuals' experiences very different, but most strikingly, the theoretical frameworks were very diverse. This was partly a function of there being understandable differences in perspectives across disciplines, but at its most marked, there were fundamental differences in the way both intellectual disability and mental health were conceptualized.  相似文献   
64.
背景 农村订单定向医学生(简称定向医学生)的免费培养工作是缓解农村地区基层医生匮乏、提升基层医疗卫生队伍整体素质和水平的重要举措。目的 探索我国定向医学生培养的研究热点、研究动态和未来趋势,为后续研究提供参考。方法 于2022-02-15,在中国知网、万方数据知识服务平台、维普网中检索2010-01-01至2021-12-31发表的关于定向医学生培养相关论文,统计其发文量,运用Cite Space软件对样本文献作者、研究机构、关键词进行知识图谱的可视化分析。结果 共纳入598篇文献,关于定向医学生培养研究的文献量呈上升趋势,2018年达到历年顶峰(n=81)。该领域存在5个大的作者群,发文量排在前3位的机构为赣南医学院[113篇(18.9%)]、广西医科大学[40篇(6.7%)]及新乡医学院[28篇(4.7%)]。关键词词频排在前3位的分别是“订单定向”(70次)、“定向生”(57次)、“人才培养”(44次)。关键词聚类图谱得到“#0学习动力”“#1教学模式”“#2定向培养”“#3影响因素”“#4全科医学”“#5基层”“#6医学院”“#7医学生”8个聚类主题。最强突现词显示,排在前3位...  相似文献   
65.
背景 小儿遗尿症是儿科常见病之一,有效的小儿遗尿症诊疗指南有助于症状的规范化控制和缓解,而制定高质量的临床实践指南是提高小儿遗尿症诊疗水平的重要方式。目的 基于AGREEⅡ和RIGHT工具,评价2010年以来国内外发布的小儿遗尿症指南和专家共识的质量,以期为临床实践及后续指南的制订提供参考。方法 检索中国知网、万方数据知识服务平台、维普网、中国生物医学文献数据库和PubMed(补充检索医脉通、世界卫生组织以及英国国家临床示范研究所等数据库)2010-01-01至2022-01-31公开发表的小儿遗尿症相关的诊疗指南和专家共识。采用AGREEⅡ和RIGHT工具评价纳入文献的方法学和报告质量。根据AGREE Ⅱ工具评价结果,将各指南/共识推荐等级评定为“推荐(A级)”“更新后推荐(B级)”和“不推荐(C级)”。使用组内相关系数(ICC)进行一致性评价。结果 纳入8部指南和5部专家共识。共形成推荐意见185条,其中44条为诊断评估方面的意见,140条为治疗方面的推荐意见,1条为随访推荐意见。AGREEⅡ工具评价结果显示,范围和目的、参与人员、严谨性、清晰性、应用性和独立性6个领域的总得分(报...  相似文献   
66.
子宫内膜息肉是妇科常见疾病,现代中医认为本病主要病理因素是瘀滞,临床常见气滞血瘀、痰湿瘀阻、湿热瘀滞、气虚血瘀、阳虚血瘀诸证,运用中医药辨证治疗、中医外治法,可有效改善临床症状,降低息肉复发率,提高妊娠率。本文将近十年中医药治疗子宫内膜息肉的临床研究作以综述。  相似文献   
67.
Chromosome banding analyses were made on 10 cases of Ph1-positive AML (7 M1 and 3 M2). The standard type Ph1 translocation, t(9q +;22q -), was identified in all of them. Karyotypically normal cells were observed in 6-65% of bone marrow metaphases at the initial cytogenetic examination of 7 patients, whereas the remaining 3 patients had only Ph1-positive cells at diagnosis. Follow-up studies performed in 5 cases indicated that the frequency of karyotypically normal cells increased up to 81-100% when the patients were in remission, whereas it was much reduced in relapse. In 5 cases, there was observed a clone of cells in which the Ph1 translocation was the sole karyotypic abnormality. Various types of other chromosome abnormalities, in addition to the Ph1, were observed in all cases, among which-7 was the most frequent, being found in three cases as a stem line. Other additional changes encountered were + Ph1, del(5), i(17q), - 10, + 18, + X, and various numerical and structural changes including certain secondary translocations that occurred in the Ph1 (22q -) or its partner (9q +). The types and frequencies of these additional changes appeared to be different from those found in the acute phase of CML or in Ph1-positive ALL.  相似文献   
68.
Male wild (Cavia aperea) and domestic (C. porcellus) guinea pigs were tested in two-bottle choice tests for preferences between glucose solutions of different concentrations and de-ionized water. Wild males showed significant preferences for concentrations between 0.025 and 0.4 M glucose while domestic males preferred only the 0.2 M glucose solution to de-ionized water. C. aperea males also consumed significantly greater volumes of liquid per kg body wt.34 during the glucose tests than did the C. porcellus males. These comparative results contrast sharply with those obtained by other authors with wild and domestic Norway rats.  相似文献   
69.
目的探讨抑郁认知理论的发展状况。方法从抑郁三联症和抑郁自我图式两方面对抑郁的认知理论的研究状况进行综述。结果抑郁三联症可缩减为对自我的消极想法1个维度,抑郁者消极自我图式中还存在大量积极信息。结论需要加强对抑郁认知理论的研究。  相似文献   
70.
BACKGROUND: The importance of the standardisation of nucleic acid amplification technology (NAT) assays for the detection of hepatitis C virus RNA is well known today, as many studies carried out in different European countries attest. The results of a previous study performed in Italy (J. Clin. Virol. 1 (2003) 83) by the Italian Society of Clinical Microbiology (AMCLI) showed that the use of external reference standards and of multicentre collaborative studies significantly improves laboratory performance for the qualitative evaluation of HCV RNA. OBJECTIVES: the AMCLI organised a new study on the standardisation of both the qualitative and the quantitative evaluation of HCV RNA with NAT in order to improve the implementation of the diagnostic methods for HCV RNA detection. STUDY DESIGN: seventeen diagnostic centres of major Italian Hospitals participated in this quality control study. The study consisted of testing three panels, each made up of 10 coded samples including negative and positive samples. Positive samples contained four levels of HCV RNA (genotype 1). RESULTS AND CONCLUSION: Seven out of 510 qualitative results obtained were incorrect (1.4%), two false negative and five false positive. The results gave a sensitivity of 99.5% and a specificity of 95.8%. Regarding quantitative tests, the geometric mean (GM) and standard deviation (S.D.) could be calculated only for the three highest HCV RNA levels. The percentage of results within the range of GM +/- 0.5 log(10) varied from 91% to 100%. Some laboratories had some difficulty in the exact quantification of the lowest (3.00 log IU/ml) as well as of the highest viral levels (6.35 log IU/ml) values, very near to the limits of the dynamic range of the assays. The comparison of the results of this study with that previously carried out one confirms that a regular participation in external quality assessment (EQA) assures the achievement of a high proficiency level in the diagnosis of HCV infection.  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