全文获取类型
收费全文 | 2739篇 |
免费 | 193篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 85篇 |
妇产科学 | 23篇 |
基础医学 | 311篇 |
口腔科学 | 64篇 |
临床医学 | 313篇 |
内科学 | 647篇 |
皮肤病学 | 47篇 |
神经病学 | 186篇 |
特种医学 | 230篇 |
外科学 | 311篇 |
综合类 | 58篇 |
一般理论 | 2篇 |
预防医学 | 140篇 |
眼科学 | 68篇 |
药学 | 167篇 |
中国医学 | 7篇 |
肿瘤学 | 326篇 |
出版年
2023年 | 14篇 |
2022年 | 13篇 |
2021年 | 47篇 |
2020年 | 29篇 |
2019年 | 48篇 |
2018年 | 54篇 |
2017年 | 46篇 |
2016年 | 52篇 |
2015年 | 80篇 |
2014年 | 117篇 |
2013年 | 128篇 |
2012年 | 172篇 |
2011年 | 163篇 |
2010年 | 131篇 |
2009年 | 111篇 |
2008年 | 132篇 |
2007年 | 197篇 |
2006年 | 155篇 |
2005年 | 136篇 |
2004年 | 120篇 |
2003年 | 118篇 |
2002年 | 108篇 |
2001年 | 80篇 |
2000年 | 74篇 |
1999年 | 67篇 |
1998年 | 46篇 |
1997年 | 52篇 |
1996年 | 43篇 |
1995年 | 43篇 |
1994年 | 32篇 |
1993年 | 31篇 |
1992年 | 40篇 |
1991年 | 21篇 |
1990年 | 28篇 |
1989年 | 22篇 |
1988年 | 29篇 |
1987年 | 29篇 |
1986年 | 19篇 |
1985年 | 25篇 |
1984年 | 17篇 |
1983年 | 11篇 |
1982年 | 19篇 |
1981年 | 12篇 |
1980年 | 14篇 |
1978年 | 9篇 |
1977年 | 11篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1971年 | 9篇 |
1970年 | 6篇 |
排序方式: 共有3010条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Hung-Fat Tse Sukumaran Thambar Yok-Lam Kwong Philip Rowlings Greg Bellamy Jane McCrohon Paul Thomas Bruce Bastian John K F Chan Gladys Lo Chi-Lai Ho Wing-Sze Chan Raymond Y Kwong Anthony Parker Thomas H Hauser Jenny Chan Daniel Y T Fong Chu-Pak Lau 《European heart journal》2007,28(24):2998-3005
AIMS: Experimental studies have demonstrated that bone marrow (BM) cells can induce angiogenesis in ischaemic myocardium. Recently, several non-randomized pilot studies have also suggested that direct BM cells implantation appears to be feasible and safe in patients with severe coronary artery diseases (CAD). METHODS AND RESULTS: We performed a randomized, blinded, and placebo-controlled trial in 28 CAD patients. After BM harvesting, we assigned patients to receive low dose (1 x 10(6) cells/0.1 mL, n = 9), high dose (2 x 10(6) cells/0.1 mL, n = 10) autologous BM cells or control (0.1 mL autologous plasma/injection, n = 9) catheter-based direct endomyocardial injection as guided by electromechanical mapping. Our primary endpoint was the increase in exercise treadmill time and our secondary endpoints were changes in Canadian Cardiovascular Society (CCS) and New York Heart Association (NYHA) class, and myocardial perfusion and left ventricular ejection fraction (LVEF) assessed by single-photon emission computed tomography and magnetic resonance imaging, respectively. A total 422 injections (mean 14.6 +/- 0.7 per patient) were successfully performed at 41 targeted ischaemic regions without any acute complication. Baseline exercise treadmill time was 439 +/- 182 s in controls and 393 +/- 136 s in BM-treated patients, and changed after 6 months to 383 +/- 223s and 464 +/- 196 s [BM treatment effect +0.43 log seconds (+53%), 95% CI 0.11-0.74, P = 0.014]. Compared with placebo injection, BM implantation was associated with a significant increase in LVEF (BM treatment effect +5.4%, 95% CI 0.4-10.3, P = 0.044) and a lower NYHA class (odds ratio for treatment effect 0.12, 95% CI 0.02-0.73, P = 0.021) after 6 months, but CCS reduced similarly in both groups. We observed no acute or long-term complications, including ventricular arrhythmia, myocardial damage, or development of intramyocardial tumour or calcification associated with BM implantation. CONCLUSION: Direct endomyocardial implantation of autologous BM cells significantly improved exercise time, LVEF, and NYHA functional class in patients with severe CAD who failed conventional therapy. 相似文献
5.
6.
Siu Fai Li MD Nashat Latib MD Angela Kwong MD Shreni Zinzuwadia MD Ethan Cowan MD 《Academic emergency medicine》2007,14(12):1194-1196
Background In recent years, the number of women entering the field of emergency medicine (EM) has increased.
Objectives To determine if authorship in EM publications has increased in parallel with this trend.
Methods The gender of first and last authors of EM articles in Academic Emergency Medicine , American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine were examined. The authors reviewed articles from 1985, 1995, and 2005 for American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine and from 1999 and 2005 for Academic Emergency Medicine . The primary outcomes were the proportions of female authors.
Results A total of 2,016 articles were reviewed. Overall, 18% of first and last authors were female. Respectively, for 1985, 1995, 1999, and 2005, the proportions of female first authors were 9%, 15%, 19%, and 24%; the proportions of female last authors were 9%, 18%, 19%, and 22%. The trend of increases in female authorship was statistically significant.
Conclusions Although female authorship remains a minority in EM publications, it has increased significantly in parallel with increases in female participation in EM. 相似文献
Objectives To determine if authorship in EM publications has increased in parallel with this trend.
Methods The gender of first and last authors of EM articles in Academic Emergency Medicine , American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine were examined. The authors reviewed articles from 1985, 1995, and 2005 for American Journal of Emergency Medicine , Annals of Emergency Medicine , and Journal of Emergency Medicine and from 1999 and 2005 for Academic Emergency Medicine . The primary outcomes were the proportions of female authors.
Results A total of 2,016 articles were reviewed. Overall, 18% of first and last authors were female. Respectively, for 1985, 1995, 1999, and 2005, the proportions of female first authors were 9%, 15%, 19%, and 24%; the proportions of female last authors were 9%, 18%, 19%, and 22%. The trend of increases in female authorship was statistically significant.
Conclusions Although female authorship remains a minority in EM publications, it has increased significantly in parallel with increases in female participation in EM. 相似文献
7.
8.
Peter Reimer Sanjay Saini Ken K. Kwong Mark S. Cohen Ralph Weissleder Thomas J. Brady 《Journal of magnetic resonance imaging : JMRI》1994,4(3):331-335
To develop guidelines for clinical magnetic resonance imaging of the liver, the authors undertook an animal study to investigate the effect of dose and pulse sequence on liver signal intensity in gadopentetate dimeglumine—enhanced echo-planar imaging. Serial imaging of the liver was performed in anesthetized rats after intravenous administration of five different doses (0.01, 0.05, 0.1, 0.2, and 0.5 mmol/kg) of contrast agent, with six different pulse sequences. The results show that gadopentetate dimeglumine—enhanced echo-planar images obtained during the perfusion phase can yield either positive (due to increased T1 relaxation rates) or negative (due to susceptibility-induced increased T2 relaxation rates) liver enhancement depending on choice of pulse sequence and dose. At the current clinically recommended dose of 0.1 mmol/kg, maximal liver signal enhancement was seen with a T1-weighted inversion-recovery sequence, while maximal liver signal diminution was seen with a T2*-weighted gradient-echo sequence. The authors conclude that gadopentetate dimeglumine—enhanced echo-planar imaging can provide T1, T2, and T2* contrast that may be exploited for both lesion detection and lesion characterization. 相似文献
9.
A 16 year old girl with post-streptococcal glomerulonephritis developed acute rheumatic fever 19 days afterwards. Previous publications on concurrent post-streptococcal glomerulonephritis and acute rheumatic fever are reviewed. 相似文献
10.
Terry Kwong MB BS FRACP Senior Fellow Elsa Valderrama MD Assistant Professor of Pediatric Pathology Carole Paley MD Assistant Professor of Pediatrics Norman Ilowite MD Associate Professor of Pediatrics 《Seminars in arthritis and rheumatism》1994,23(6)
Childhood sarcoidosis is a rare disorder with protean manifestations. The case of a child with prolonged fever, hepatosplenomegaly, pancytopenia, and systemic necrotizing vasculitis manifesting as fever, rash and skin infarctions, digital pregangrene, and foot drop is reported. This is the first case of systemic necrotizing vasculitis reported in sarcoidosis. The fulminant course of the disease required treatment with intravenous pulsed cyclophosphamide and high doses of corticosteroids. The spectrum of vasculitis in childhood and adult sarcoidosis is reviewed. 相似文献