全文获取类型
收费全文 | 3441032篇 |
免费 | 246071篇 |
国内免费 | 10848篇 |
专业分类
耳鼻咽喉 | 45853篇 |
儿科学 | 112847篇 |
妇产科学 | 94946篇 |
基础医学 | 486972篇 |
口腔科学 | 94973篇 |
临床医学 | 322858篇 |
内科学 | 669507篇 |
皮肤病学 | 78433篇 |
神经病学 | 285480篇 |
特种医学 | 130067篇 |
外国民族医学 | 1049篇 |
外科学 | 502599篇 |
综合类 | 72422篇 |
现状与发展 | 6篇 |
一般理论 | 1373篇 |
预防医学 | 274990篇 |
眼科学 | 77190篇 |
药学 | 251549篇 |
14篇 | |
中国医学 | 7516篇 |
肿瘤学 | 187307篇 |
出版年
2019年 | 27954篇 |
2018年 | 39193篇 |
2017年 | 29941篇 |
2016年 | 34180篇 |
2015年 | 38591篇 |
2014年 | 53212篇 |
2013年 | 81164篇 |
2012年 | 108522篇 |
2011年 | 114910篇 |
2010年 | 68885篇 |
2009年 | 65234篇 |
2008年 | 106733篇 |
2007年 | 113115篇 |
2006年 | 114745篇 |
2005年 | 110039篇 |
2004年 | 105666篇 |
2003年 | 101820篇 |
2002年 | 98495篇 |
2001年 | 159689篇 |
2000年 | 163948篇 |
1999年 | 138442篇 |
1998年 | 40524篇 |
1997年 | 36017篇 |
1996年 | 35987篇 |
1995年 | 34722篇 |
1994年 | 32066篇 |
1993年 | 30134篇 |
1992年 | 108763篇 |
1991年 | 105194篇 |
1990年 | 101984篇 |
1989年 | 98167篇 |
1988年 | 90122篇 |
1987年 | 88474篇 |
1986年 | 83448篇 |
1985年 | 79775篇 |
1984年 | 59661篇 |
1983年 | 50939篇 |
1982年 | 30400篇 |
1981年 | 27100篇 |
1979年 | 53299篇 |
1978年 | 37868篇 |
1977年 | 31767篇 |
1976年 | 30033篇 |
1975年 | 31589篇 |
1974年 | 37706篇 |
1973年 | 36082篇 |
1972年 | 33703篇 |
1971年 | 31343篇 |
1970年 | 28996篇 |
1969年 | 27464篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Bernard–Soulier syndrome (BSS) is a rare autosomal recessively inherited bleeding disorder. Pregnancy in patients with BSS is characterized by ante‐, intra‐, or postpartum haemorrhage, which may be delayed and severe. There is no consensus in the management of BSS in pregnancy and so far only 16 pregnancies in nine patients have been described. We report a further three pregnancies in two women with the syndrome. We also outline our management of pregnant patients with BSS. 相似文献
62.
63.
G Steinitz M C Martín N Gazit-Yaari M L Quesada J de la Nuez R Casillas U Malik Z B Begin 《Applied radiation and isotopes》2006,64(4):520-524
Multi-day signals, generally with duration of 2-10 days, are a prominent temporal variation type of radon (Rn) in geogas in the unsaturated zone. Rare multi-day Rn signals have been found which are characterized by: (a) a declining limb lasting up to 10 days which conforms to the radioactive decay of Rn, (b) recurs at the same location and (c) is recorded in diverse situations-volcanic and seismogenic. It suggested that a Rn blob is injected at a lower level on a steady upward flow of geogas whereby the rise and final fall of the signal are attributed to the edges of the blob while the central Rn-decay segment records the passing of the decaying blob itself. Rn-decay signals are a small subset of multi-day Rn signals which are considered as highly irregular and unusable for the understanding of geophysical processes. In difference, it is concluded that multi-day Rn signals are probably proxies of subtle geodynamic processes at upper crustal levels and are therefore significant for studying such processes. 相似文献
64.
65.
D B Irving J L Cook H B Menz 《Journal of Science and Medicine in Sport》2006,9(1-2):11-22; discussion 23-4
66.
Nishard Abdeen Albert Cross Gregory Cron Steven White Thomas Rand David Miller Giles Santyr 《Magnetic resonance in medicine》2006,56(2):255-264
We used the dual capability of hyperpolarized 129Xe for spectroscopy and imaging to develop new measures of xenon diffusing capacity in the rat lung that (analogously to the diffusing capacity of carbon monoxide or DLCO) are calculated as a product of total lung volume and gas transfer rate constants divided by the pressure gradient. Under conditions of known constant pressure breath-hold, the volume is measured by hyperpolarized 129Xe MRI, and the transfer rate is measured by dynamic spectroscopy. The new quantities (xenon diffusing capacity in lung parenchyma (DLXeLP)), xenon diffusing capacity in RBCs (DLXeRBC), and total lung xenon diffusing capacity (DLXe)) were measured in six normal rats and six rats with lung inflammation induced by instillation of fungal spores of Stachybotrys chartarum. DLXeLP, DLXeRBC, and DLXe were 56 +/- 10 ml/min/mmHg, 64 +/- 35 ml/min/mmHg, and 29 +/- 9 ml/min/mmHg, respectively, for normal rats, and 27 +/- 9 ml/min/mmHg, 42 +/- 27 ml/min/mmHg, and 16 +/- 7 ml/min/mmHg, respectively, for diseased rats. Lung volumes and gas transfer times for LP (TtrLP) were 16 +/- 2 ml and 22 +/- 3 ms, respectively, for normal rats and 12 +/- 2 ml and 35 +/- 8 ms, respectively, for diseased rats. Xenon diffusing capacities may be useful for measuring changes in gas exchange associated with inflammation and other lung diseases. 相似文献
67.
Fast CT-PRESS-based spiral chemical shift imaging at 3 Tesla. 总被引:2,自引:0,他引:2
Dirk Mayer Dong-Hyun Kim Elfar Adalsteinsson Daniel M Spielman 《Magnetic resonance in medicine》2006,55(5):974-978
A new sequence is presented that combines constant-time point-resolved spectroscopy (CT-PRESS) with fast spiral chemical shift imaging. It allows the acquisition of multivoxel spectra without line splitting with a minimum total measurement time of less than 5 min for a field of view of 24 cm and a nominal 1.5x1.5-cm2 in-plane resolution. Measurements were performed with 17 CS encoding steps in t1 (Deltat1=12.8 ms) and an average echo time of 151 ms, which was determined by simulating the CT-PRESS experiment for the spin systems of glutamate (Glu) and myo-inositol (mI). Signals from N-acetyl-aspartate, total creatine, choline-containing compounds (Cho), Glu, and mI were detected in a healthy volunteer with no or only minor baseline distortions within 14 min on a 3 T MR scanner. 相似文献
68.
69.
70.
Barry L Eppley A Michael Sadove David Hennon John A van Aalst 《The Cleft palate-craniofacial journal》2006,43(3):374-378
OBJECTIVE: A series of nasopharyngeal appliance designs is presented that represents our evolving experience over a 20-year period in the adjunctive use of prosthetic stents in the surgical correction of nasopharyngeal stenosis. DESIGN: Retrospective assessment of effectiveness of two nasopharyngeal stenosis hollow stent designs in a consecutive series of patients for relief of nasal obstructive symptoms. SETTING: Tertiary academic medical center, Craniofacial Program at Children's Hospital. PATIENTS: Four patients with nasopharyngeal stenosis were treated with a preoperatively fabricated stent made from a clasped palatal appliance onto which hollow acrylic conduits were extended through surgically re-created pharyngeal ports. A subsequent set of four patients with nasopharyngeal stenosis were treated with intraoperatively-fashioned silastic grommets, as opposed to palatal appliances. INTERVENTIONS: Postoperative intraoral stenting of nasopharyngeal ports. MAIN OUTCOME MEASURES: Maintenance of pharyngeal port opening after 1 year, improvement in nasal airway obstructive symptoms. RESULTS: The palatal appliance stents were less well tolerated and had a lower maintenance of port patency after device removal (4 of 8, 50%). The silastic grommets provided better retention into the ports and increased patient tolerance, as well as better 1-year port maintenance (6 of 8, 75%). CONCLUSIONS: The grommet stent appliance offers numerous advantages over a conventional dental-clasped appliance for prosthetic nasopharyngeal stenting, including obviation of extensive preoperative preparation, ease of insertion and removal, and exchange of air during the stenting period. Improved nasopharyngeal patency with this device may be due to greater patient tolerance and subsequent longer use. 相似文献