全文获取类型
收费全文 | 1873330篇 |
免费 | 337070篇 |
国内免费 | 40810篇 |
专业分类
耳鼻咽喉 | 25964篇 |
儿科学 | 54051篇 |
妇产科学 | 49895篇 |
基础医学 | 302055篇 |
口腔科学 | 49295篇 |
临床医学 | 189768篇 |
内科学 | 396437篇 |
皮肤病学 | 38138篇 |
神经病学 | 151906篇 |
特种医学 | 75062篇 |
外国民族医学 | 498篇 |
外科学 | 293233篇 |
综合类 | 88867篇 |
现状与发展 | 2篇 |
一般理论 | 505篇 |
预防医学 | 158452篇 |
眼科学 | 55524篇 |
药学 | 173124篇 |
3篇 | |
中国医学 | 49865篇 |
肿瘤学 | 98566篇 |
出版年
2019年 | 24252篇 |
2018年 | 29191篇 |
2017年 | 26579篇 |
2016年 | 26464篇 |
2015年 | 28345篇 |
2014年 | 34780篇 |
2013年 | 46590篇 |
2012年 | 57897篇 |
2011年 | 62067篇 |
2010年 | 44879篇 |
2009年 | 49898篇 |
2008年 | 57475篇 |
2007年 | 57780篇 |
2006年 | 57136篇 |
2005年 | 56298篇 |
2004年 | 56807篇 |
2003年 | 54478篇 |
2002年 | 53116篇 |
2001年 | 81329篇 |
2000年 | 79155篇 |
1999年 | 72481篇 |
1998年 | 29185篇 |
1997年 | 27162篇 |
1996年 | 27286篇 |
1995年 | 26586篇 |
1994年 | 25648篇 |
1993年 | 23791篇 |
1992年 | 60174篇 |
1991年 | 58144篇 |
1990年 | 56440篇 |
1989年 | 54484篇 |
1988年 | 51138篇 |
1987年 | 49990篇 |
1986年 | 47701篇 |
1985年 | 45276篇 |
1984年 | 34617篇 |
1983年 | 30287篇 |
1982年 | 21402篇 |
1981年 | 19415篇 |
1979年 | 33989篇 |
1978年 | 25073篇 |
1977年 | 22032篇 |
1976年 | 20533篇 |
1975年 | 21800篇 |
1974年 | 25679篇 |
1973年 | 24471篇 |
1972年 | 23382篇 |
1971年 | 21437篇 |
1970年 | 20445篇 |
1969年 | 19252篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
Bifid mandibular canal. 总被引:1,自引:0,他引:1
PURPOSE: To determine the incidence and characteristics of bifid mandibular canals. METHODS: A retrospective study was performed using panoramic radiographs of 2012 patients subjected to dental treatment in the Dental Clinic of the Valencia University Dental School (Valencia, Spain) between 1996 and 1999. The goal was to investigate the presence of double mandibular canals. RESULTS: The extraoral panoramic radiographs revealed a total of 7 images suggestive of bifid canals. Mandibular computed tomography revealed the existence of this anatomic variant in 2 of 3 patients. An analysis was performed on the incidence of this type of image in extraoral panoramic radiography, its possible interpretations, and the clinical implications of bifid mandibular canals. CONCLUSIONS: In this study, 0.35% of canals were bifid. All cases were in women. 相似文献
63.
64.
Lisa A. Lang DDS MS David C. Holmes DDS MS Craig Passon DDS MS Robert M. Trombly DDS JD Jeffrey D. Astroth DDS MSPH Arnold F. Tavel DMD 《Journal of prosthodontics》2003,12(3):206-210
Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience. 相似文献
65.
F Pitta T Troosters V S Probst M A Spruit M Decramer R Gosselink 《The European respiratory journal》2006,27(5):1040-1055
Accurate assessment of the amount and intensity of physical activity in daily life is considered very important due to the close relationship between physical activity level, health, disability and mortality. For this reason, assessment of physical activity in daily life has gained interest in recent years, especially in sedentary populations, such as patients with chronic obstructive pulmonary disease (COPD). The present article aims to compare and discuss the two kinds of instruments more commonly used to quantify the amount of physical activity performed by COPD patients in daily life: subjective methods (questionnaires, diaries) and motion sensors (electronic or mechanical methods). Their characteristics are summarised and evidence of their validity, reliability and sensitivity is discussed, when available. Subjective methods have practical value mainly in providing the patients' view on their performance in activities of daily living and functional status. However, care must be taken when using subjective methods to accurately quantify the amount of daily physical activity performed. More accurate information is likely to be available with motion sensors rather than questionnaires. The selection of which motion sensor to use for quantification of physical activity in daily life should depend mainly on the purpose of its use. 相似文献
66.
C T Gan G P McCann J T Marcus S A van Wolferen J W Twisk A Boonstra P E Postmus A Vonk-Noordegraaf 《The European respiratory journal》2006,28(6):1190-1194
The aim of the current study was to investigate whether alterations in N-terminal pro brain natriuretic peptide (NT-proBNP) reflect changes in right ventricular structure and function in pulmonary hypertension patients during treatment. The study consisted of 30 pulmonary hypertension patients; 15 newly diagnosed and 15 on long-term treatment. NT-proBNP, right heart catheterisation and cardiac magnetic resonance imaging measurements were performed, at baseline and follow-up. There were no significant differences between newly diagnosed patients and those on treatment at baseline or follow-up with respect to NT-proBNP, haemodynamics and right ventricular parameters. Relative changes in NT-proBNP during treatment were correlated to the relative changes in right ventricular end-diastolic volume index (r = 0.59), right ventricular mass index (r = 0.62) and right ventricular ejection fraction (r = -0.81). N-terminal pro brain natriuretic peptide measurements reflect changes in magnetic resonance imaging-measured right ventricular structure and function in pulmonary hypertension patients. An increase in N-terminal pro brain natriuretic peptide over time reflects right ventricular dilatation concomitant to hypertrophy and deterioration of systolic function. 相似文献
67.
Chan C. H. Y Ng E. H. Y Chan C. L W 《世界核心医学期刊文摘》2006,2(6):15-15
目的:评价东部身体-智力-精神(EBMS)群体干预对进行体外受精(IVF)的中国妇女焦虑缓解的作用。设计:随机对照研究。机构:三级辅助生殖机构。受试者:227例接受第1个IVF周期治疗的妇女。干预:干预组(n=69)接受4次EBMS群体咨询,而对照组(n=115)无任何干预。主要观察指标:状态-特质焦虑问卷。结果:与对照组相比,干预组在干预后状态焦虑平均分显著下降。每组移植同样数目的卵子,但干预组没有明显更高妊娠率的倾向。 相似文献
68.
69.
70.
Abstract The pain of cluster headache attacks is severe, excruciating and selectively responsive to subcutaneous sumatriptan. Serious
cardiovascular events attributed to sumatriptan are extremely rare and have most often been reported in patients at significant
cardiovascular risk, or in overt cardiovascular disease. They also have occurred, however, in patients without evidence of
cardiovascular disease. We describe a 42-year-old man with episodic cluster headache without history of coronary artery disease
who was admitted to our coronary care unit for acute myocardial infarction after 3 h of subcutaneous injection of sumatriptan.
During hospitalisation cluster headache attacks were successfully treated with e.v. indomethacin. 相似文献