全文获取类型
收费全文 | 612篇 |
免费 | 1篇 |
国内免费 | 3篇 |
专业分类
综合类 | 615篇 |
基础理论 | 1篇 |
出版年
2021年 | 6篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2012年 | 14篇 |
2011年 | 72篇 |
2010年 | 59篇 |
2009年 | 46篇 |
2008年 | 37篇 |
2007年 | 49篇 |
2006年 | 44篇 |
2005年 | 44篇 |
2004年 | 43篇 |
2003年 | 41篇 |
2002年 | 39篇 |
2001年 | 27篇 |
1995年 | 36篇 |
1994年 | 28篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1983年 | 3篇 |
排序方式: 共有616条查询结果,搜索用时 748 毫秒
271.
272.
The suspicion of an abnormality of the central nervous (CNS) system raises difficult questions for the clinician and the family and will inevitably lead to considerable anxiety. These questions include what it means for the child's future, whether it can be treated and whether it will happen again in subsequent pregnancies. For many disorders accurate prenatal diagnosis remains elusive, as even with fetal magnetic resonance imaging (MRI), early recognition and characterisation are simply not possible because of the immature state of brain development at that stage of pregnancy. The natural history of many prenatally diagnosed CNS disorders remains to be elucidated which means that an accurate prognosis cannot be given in all cases. We review the current state of knowledge regarding the investigation, management and prognosis of the most common and important CNS malformations. We also discuss the post-natal management of these conditions both in the neonate and subsequent pregnancies for the families. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
273.
274.
Fetal cardiac function is increasingly recognized as a marker of disease severity and prognosis in selected fetal conditions. Magnetic resonance imaging (MRI) has been used in experimental (animal) fetal cardiology but the lack of a noninvasive fetal electrocardiogram (ECG) to trigger image acquisition remains a major limiting factor precluding its application in humans. Fetal medicine specialists are therefore limited to ultrasound to evaluate human fetal cardiac function. In this review, we aim to provide a complete overview of the different ultrasound techniques that can be used for fetal cardiac function assessment and we discuss their (theoretical) strengths and shortcomings. Conventional methods include M-mode assessment of ventricular contractility and Doppler assessment of the precordial veins and cardiac output (CO). More recent techniques such as the measurement of the myocardial performance index (MPI), myocardial motion analysis with tissue Doppler, speckle tracking and three-dimensional (3D) ultrasound techniques are also discussed. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
275.
276.
277.
278.
279.
280.