全文获取类型
收费全文 | 256篇 |
免费 | 34篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 3篇 |
妇产科学 | 5篇 |
基础医学 | 51篇 |
口腔科学 | 1篇 |
临床医学 | 5篇 |
内科学 | 36篇 |
皮肤病学 | 1篇 |
神经病学 | 35篇 |
特种医学 | 69篇 |
外科学 | 25篇 |
综合类 | 8篇 |
预防医学 | 16篇 |
眼科学 | 3篇 |
药学 | 13篇 |
肿瘤学 | 25篇 |
出版年
2023年 | 6篇 |
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 16篇 |
2019年 | 40篇 |
2018年 | 19篇 |
2017年 | 14篇 |
2016年 | 10篇 |
2015年 | 16篇 |
2014年 | 15篇 |
2013年 | 14篇 |
2012年 | 8篇 |
2011年 | 15篇 |
2010年 | 8篇 |
2009年 | 2篇 |
2008年 | 13篇 |
2007年 | 5篇 |
2006年 | 15篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1990年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有299条查询结果,搜索用时 0 毫秒
41.
Improving hyperpolarized 129Xe ADC mapping in pediatric and adult lungs with uncertainty propagation
42.
43.
44.
45.
46.
47.
48.
Impaired attention is evident in several neurological and psychiatric disorders. In the present study, attentional capabilities were measured in the operant five-choice serial reaction time task (5-CSRTT) in male (C57BL/6Jx129Sv)F2 hybrid (B6129F2) mice. Main aims were to validate and standardize the test in these mice: to setup procedures, measure potential beneficial effects of sub-chronic nicotine in degraded versions of the 5-CSRTT (by decreasing stimulus duration, inducing white noise and making the stimuli unpredictable) and study disruptive effects of additional administration of the muscarinic antagonist scopolamine. During the baseline pre-nicotine sessions, the B6129F2 mice attained a very good performance in the test (95% accuracy). As stimulus duration was reduced from 2 s to 1 s, response accuracy of the mice decreased. Mice treated with nicotine (0.16 mg/kg) attained significantly higher response accuracy and had a lower percentage of incorrect responses in comparison with the solvent-treated animals. No further beneficial effects of nicotine were found. Reduced response accuracy was also obtained when stimulus duration was reduced from 1 s to 0.5 s and when a variable intertrial interval was introduced. Noise interpolation between trials did not impair performance. Finally, scopolamine (0.16 mg/kg) disrupted attentional functioning. Although most studies have been performed in rats, these results add to the existing evidence that the 5-CSRTT can also be used to assess attentional performance in mice. This offers the opportunity to test transgenic and knockout mice with similar background as the B6129F2 as animal models of psychiatric and neurological diseases. 相似文献
49.
Reproducibility of quantitative indices of lung function and microstructure from 129Xe chemical shift saturation recovery (CSSR) MR spectroscopy
下载免费PDF全文
![点击此处可从《Magnetic resonance in medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
50.
John P. Mugler III PhD Talissa A. Altes MD 《Journal of magnetic resonance imaging : JMRI》2013,37(2):313-331
By permitting direct visualization of the airspaces of the lung, magnetic resonance imaging (MRI) using hyperpolarized gases provides unique strategies for evaluating pulmonary structure and function. Although the vast majority of research in humans has been performed using hyperpolarized 3He, recent contraction in the supply of 3He and consequent increases in price have turned attention to the alternative agent, hyperpolarized 129Xe. Compared to 3He, 129Xe yields reduced signal due to its smaller magnetic moment. Nonetheless, taking advantage of advances in gas‐polarization technology, recent studies in humans using techniques for measuring ventilation, diffusion, and partial pressure of oxygen have demonstrated results for hyperpolarized 129Xe comparable to those previously demonstrated using hyperpolarized 3He. In addition, xenon has the advantage of readily dissolving in lung tissue and blood following inhalation, which makes hyperpolarized 129Xe particularly attractive for exploring certain characteristics of lung function, such as gas exchange and uptake, which cannot be accessed using 3He. Preliminary results from methods for imaging 129Xe dissolved in the human lung suggest that these approaches will provide new opportunities for quantifying relationships among gas delivery, exchange, and transport, and thus show substantial potential to broaden our understanding of lung disease. Finally, recent changes in the commercial landscape of the hyperpolarized‐gas field now make it possible for this innovative technology to move beyond the research laboratory. J. Magn. Reson. Imaging 2013;37:313–331. © 2012 Wiley Periodicals, Inc. 相似文献