全文获取类型
收费全文 | 57740篇 |
免费 | 3970篇 |
国内免费 | 224篇 |
专业分类
耳鼻咽喉 | 683篇 |
儿科学 | 1472篇 |
妇产科学 | 1080篇 |
基础医学 | 7238篇 |
口腔科学 | 948篇 |
临床医学 | 5584篇 |
内科学 | 11830篇 |
皮肤病学 | 711篇 |
神经病学 | 5545篇 |
特种医学 | 1940篇 |
外国民族医学 | 4篇 |
外科学 | 9779篇 |
综合类 | 813篇 |
现状与发展 | 1篇 |
一般理论 | 69篇 |
预防医学 | 5092篇 |
眼科学 | 1180篇 |
药学 | 3550篇 |
中国医学 | 62篇 |
肿瘤学 | 4353篇 |
出版年
2023年 | 220篇 |
2022年 | 422篇 |
2021年 | 994篇 |
2020年 | 557篇 |
2019年 | 947篇 |
2018年 | 1156篇 |
2017年 | 795篇 |
2016年 | 890篇 |
2015年 | 992篇 |
2014年 | 1642篇 |
2013年 | 2434篇 |
2012年 | 3575篇 |
2011年 | 3881篇 |
2010年 | 2188篇 |
2009年 | 2016篇 |
2008年 | 3503篇 |
2007年 | 3681篇 |
2006年 | 3656篇 |
2005年 | 3747篇 |
2004年 | 3676篇 |
2003年 | 3358篇 |
2002年 | 3291篇 |
2001年 | 472篇 |
2000年 | 358篇 |
1999年 | 565篇 |
1998年 | 748篇 |
1997年 | 635篇 |
1996年 | 571篇 |
1995年 | 538篇 |
1994年 | 482篇 |
1993年 | 439篇 |
1992年 | 358篇 |
1991年 | 364篇 |
1990年 | 297篇 |
1989年 | 302篇 |
1988年 | 285篇 |
1987年 | 272篇 |
1986年 | 253篇 |
1985年 | 302篇 |
1984年 | 468篇 |
1983年 | 399篇 |
1982年 | 522篇 |
1981年 | 508篇 |
1980年 | 495篇 |
1979年 | 251篇 |
1978年 | 291篇 |
1977年 | 284篇 |
1976年 | 221篇 |
1975年 | 218篇 |
1974年 | 235篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
22.
23.
Joseph F Malouf Manfredi Ballo Heidi M Connolly David O Hodge Regina M Herges Charles J Mullany Fletcher A Miller 《Journal of the American Society of Echocardiography》2005,18(3):252-256
The purpose of this study was to provide, in a large number of patients, comprehensive Doppler echocardiographic assessment of normal St Jude Medical mitral valve prosthesis function using Doppler-derived hemodynamic variables, including the mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio and prosthesis performance index. The pressure half-time was less than 130 milliseconds in all patients, and all but one patient had either a peak early mitral diastolic velocity of 2 m/s or less or a mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio of less than 2.2. There was a significant (P < .001) negative correlation between the prosthesis performance index and prosthesis size. This negative correlation suggests that there is more efficient use of the in vitro geometric orifice area with smaller prostheses. 相似文献
24.
25.
26.
27.
Charles Opondo Stephen Ntoburi John Wagai Jackline Wafula Aggrey Wasunna Fred Were Annah Wamae Santau Migiro Grace Irimu Mike English 《Tropical medicine & international health : TM & IH》2009,14(10):1165-1172
Objective To assess the availability of resources that support the provision of basic neonatal care in eight first‐referral level (district) hospitals in Kenya. Methods We selected two hospitals each from four of Kenya’s eight provinces with the aim of representing the diversity of this part of the health system in Kenya. We created a checklist of 53 indicator items necessary for providing essential basic care to newborns and assessed their availability at each of the eight hospitals by direct observation, and then compared our observations with the opinions of health workers providing care to newborns on recent availability for some items, using a self‐administered structured questionnaire. Results The hospitals surveyed were often unable to maintain a safe hygienic environment for patients and health care workers; staffing was insufficient and sometimes poorly organised to support the provision of care; some key equipment, laboratory tests, drugs and consumables were not available while patient management guidelines were missing in all sites. Conclusion Hospitals appear relatively poorly prepared to fill their proposed role in ensuring newborn survival. More effective interventions are needed to improve them to meet the special needs of this at‐risk group. 相似文献
28.
29.
30.
Charles D Phillips 《BMC health services research》2006,6(1):117-4
This commentary discusses the need for, and the advantages of, a more concise, revised definition of the field of health services
research. It argues for a definition that includes not only the topics on which health services research focuses but also
the goals of health services research. A number of condensed definitions are provided for consideration. 相似文献