收费全文 | 7880篇 |
免费 | 539篇 |
国内免费 | 17篇 |
耳鼻咽喉 | 38篇 |
儿科学 | 200篇 |
妇产科学 | 77篇 |
基础医学 | 916篇 |
口腔科学 | 322篇 |
临床医学 | 1012篇 |
内科学 | 1348篇 |
皮肤病学 | 44篇 |
神经病学 | 734篇 |
特种医学 | 275篇 |
外科学 | 862篇 |
综合类 | 501篇 |
一般理论 | 12篇 |
预防医学 | 942篇 |
眼科学 | 158篇 |
药学 | 639篇 |
中国医学 | 3篇 |
肿瘤学 | 353篇 |
2023年 | 39篇 |
2022年 | 49篇 |
2021年 | 163篇 |
2020年 | 95篇 |
2019年 | 139篇 |
2018年 | 204篇 |
2017年 | 127篇 |
2016年 | 161篇 |
2015年 | 163篇 |
2014年 | 224篇 |
2013年 | 345篇 |
2012年 | 585篇 |
2011年 | 672篇 |
2010年 | 345篇 |
2009年 | 308篇 |
2008年 | 564篇 |
2007年 | 652篇 |
2006年 | 579篇 |
2005年 | 591篇 |
2004年 | 573篇 |
2003年 | 570篇 |
2002年 | 487篇 |
2001年 | 95篇 |
2000年 | 69篇 |
1999年 | 70篇 |
1998年 | 100篇 |
1997年 | 55篇 |
1996年 | 41篇 |
1995年 | 42篇 |
1994年 | 38篇 |
1993年 | 46篇 |
1992年 | 24篇 |
1991年 | 20篇 |
1990年 | 21篇 |
1989年 | 16篇 |
1988年 | 17篇 |
1987年 | 15篇 |
1986年 | 20篇 |
1985年 | 16篇 |
1984年 | 16篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1974年 | 4篇 |
1973年 | 3篇 |
Purpose
To image multidimensional flow in fetuses using golden-angle radial phase contrast cardiovascular magnetic resonance (PC-CMR) with motion correction and retrospective gating.Methods
A novel PC-CMR method was developed using an ungated golden-angle radial acquisition with continuously incremented velocity encoding. Healthy subjects (n?=?5, 27?±?3 years, males) and pregnant females (n?=?5, 34?±?2 weeks gestation) were imaged at 3 T using the proposed sequence. Real-time reconstructions were first performed for retrospective motion correction and cardiac gating (using metric optimized gating, MOG). CINE reconstructions of multidimensional flow were then performed using the corrected and gated data.Results
In adults, flows obtained using the proposed method agreed strongly with those obtained using a conventionally gated Cartesian acquisition. Across the five adults, bias and limits of agreement were ??1.0 cm/s and [??5.1, 3.2] cm/s for mean velocities and???1.1 cm/s and [??6.5, 4.3] cm/s for peak velocities. Temporal correlation between corresponding waveforms was also high (R~?0.98). Calculated timing errors between MOG and pulse-gating RR intervals were low (~?20 ms). First insights into multidimensional fetal blood flows were achieved. Inter-subject consistency in fetal descending aortic flows (n =?3) was strong with an average velocity of 27.1?±?0.4 cm/s, peak systolic velocity of 70.0?±?1.8 cm/s and an intra-class correlation coefficient of 0.95 between the velocity waveforms. In one fetal case, high flow waveform reproducibility was demonstrated in the ascending aorta (R =?0.97) and main pulmonary artery (R =?0.99).Conclusion
Multidimensional PC-CMR of fetal flow was developed and validated, incorporating retrospective motion compensation and cardiac gating. Using this method, the first quantification and visualization of multidimensional fetal blood flow was achieved using CMR.![点击此处可从《Journal of ultrasound in medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
- Implications for rehabilitation
The Evaluation of Daily Activity Questionnaire evaluates users’ ability to perform common daily activities (in 12 domains) that were identified as problematic by people with seven musculoskeletal conditions (i.e., osteoarthritis, systemic lupus, ankylosing spondylitis, chronic pain, chronic upper limb conditions, systemic sclerosis, Sjogren’s syndrome).
Most patients considered the Evaluation of Daily Activity Questionnaire was the right length and would be helpful for discussing everyday problems with an occupational therapist.
The 12 domains have good reliability and validity and can be combined into two components: Self-Care and Mobility.
The Evaluation of Daily Activity Questionnaire is suitable for use both in clinical practice and research and a User Manual is available for therapists and researchers.