全文获取类型
收费全文 | 6251篇 |
免费 | 668篇 |
国内免费 | 171篇 |
专业分类
耳鼻咽喉 | 56篇 |
儿科学 | 351篇 |
妇产科学 | 159篇 |
基础医学 | 227篇 |
口腔科学 | 84篇 |
临床医学 | 1299篇 |
内科学 | 1386篇 |
皮肤病学 | 120篇 |
神经病学 | 411篇 |
特种医学 | 224篇 |
外国民族医学 | 1篇 |
外科学 | 1711篇 |
综合类 | 19篇 |
预防医学 | 379篇 |
眼科学 | 328篇 |
药学 | 82篇 |
肿瘤学 | 253篇 |
出版年
2023年 | 110篇 |
2021年 | 67篇 |
2020年 | 105篇 |
2019年 | 58篇 |
2018年 | 141篇 |
2017年 | 181篇 |
2016年 | 199篇 |
2015年 | 144篇 |
2014年 | 235篇 |
2013年 | 314篇 |
2012年 | 131篇 |
2011年 | 144篇 |
2010年 | 238篇 |
2009年 | 351篇 |
2008年 | 149篇 |
2007年 | 85篇 |
2006年 | 135篇 |
2005年 | 108篇 |
2004年 | 70篇 |
2003年 | 79篇 |
2002年 | 75篇 |
2001年 | 136篇 |
2000年 | 95篇 |
1999年 | 158篇 |
1998年 | 182篇 |
1997年 | 214篇 |
1996年 | 312篇 |
1995年 | 264篇 |
1994年 | 202篇 |
1993年 | 128篇 |
1992年 | 149篇 |
1991年 | 161篇 |
1990年 | 97篇 |
1989年 | 155篇 |
1988年 | 126篇 |
1987年 | 101篇 |
1986年 | 120篇 |
1985年 | 104篇 |
1984年 | 100篇 |
1983年 | 89篇 |
1982年 | 76篇 |
1981年 | 63篇 |
1980年 | 83篇 |
1979年 | 47篇 |
1978年 | 59篇 |
1977年 | 46篇 |
1976年 | 47篇 |
1975年 | 54篇 |
1964年 | 49篇 |
1963年 | 47篇 |
排序方式: 共有7090条查询结果,搜索用时 15 毫秒
41.
W. G. Selley FDS Hon FCST R. E. Ellis MPhil F. C. Flack PhD C. R. Bayliss MB B Chir FRCR V. R. Pearce MB FRCP 《Dysphagia》1994,9(3):162-167
Simultaneous recording of adult subjects sipping small amounts of fluid from a cup have been obtained by videofluoroscopy together with feeding respiratory patterns and swallow sounds from the Exeter Dysphagia Assessment Technique (EDAT). These allowed visual representations of respiration and swallow sounds to be superimposed on a videofluoroscopy recording using a split-screen technique. Sequentially numbered, 1/50 sec, half-frame photographic prints were examined and schematic drawings of the relevant radiographs were made. These were superimposed on to the actual EDAT printed chart of the same swallow event, theri exact time relationship with respiration and cervical swallow sounds being preserved. The results allow events in the barium videofluoroscopy to be related to events in the feeding respiratory pattern and swallow sounds recorded by EDAT. 相似文献
42.
Six cases were examined to review the important anaesthetic implications of Larsen's syndrome. Potential problems arising in these patients are highlighted and emphasis placed on cervical spine and airway/respiratory management. 相似文献
43.
44.
P. Heyman D. Duh B. Van Der Kuylen C. Cochez M. Van Esbroeck C. Vandenvelde T. Avsic‐Zupanc 《Transboundary and Emerging Diseases》2007,54(5):276-279
This case report describes a dog suffering from a co‐infection with Babesia and Anaplasma parasites. Anaplasma platys was found to be responsible for the anaplasmosis by molecular biology techniques, while microscopical and serological evidence was found for a coexistent babesiosis, although this could not be confirmed by polymerase chain reaction. Moreover, the possible risk of import of exotic pathogens is highlighted. 相似文献
45.
46.
Depth of epidural space in children 总被引:1,自引:0,他引:1
M. A. Hasan MB ChB DA FRCA R. F. Howard BSc MB ChB FRCA A. R. Lloyd-Thomas MB BS FRCA 《Anaesthesia》1994,49(12):1085-1087
47.
48.
49.
G. J. Wiener MD T. M. Morgan PhD J. B. Copper PA W.C. Wu MB BS D. O. Castell MD J. W. Sinclair PA Dr. J. E. Richter MD 《Digestive diseases and sciences》1988,33(9):1127-1133
If 24-hour esophageal pH monitoring is to be a useful diagnostic tool, it must reliably discriminate gastroesophageal reflux patients despite daily variations in distal esophageal acid exposure. To address this issue, we studied 53 subjects (14 healthy normals, 14 esophagitis patients, and 25 patients with atypical symptoms) with two ambulatory pH tests performed within 10 days of each other. Intrasubject reproducibility of 12 pH parameters to discriminate the presence of abnormal acid reflux was determined. As a group, the parameters of percent time with pH<4 (total, upright, recumbent) were most reproducible (80%). Therefore, a subject was defined as having gastroesophageal reflux disease if at least one of these three values were abnormal. Intrasubject reproducibility for the diagnosis of reflux disease was 89% for the entire sample. Among subsets, the reproducibility was 93% for the normals and esophagitis patients and 84% for the atypical symptom patients. Total percent time with pH<4 was the single most discriminate pH parameter (85%) and nearly equaled that of the three combined parameters (89%). The intrasubject variability of this parameter was determined by the mean ±2sd of the relative differences between the two test results for all 53 subjects. Total percent time with pH<4 may vary between tests by a factor of 3.2-fold or less (218% higher to 69% lower). We conclude: (1) ambulatory 24-hr esophageal monitoring is a reproducible test for the diagnosis of gastroesophageal reflux disease; and (2) the large intrastudy variability in 24-hr total acid exposure may limit this test's usefulness as a measurement of therapeutic improvement.Supported, in part, by Public Health Services Grant AM 34200-01A1 from NIADDIK. 相似文献
50.
Development of a reconstructed human skin model for angiogenesis 总被引:4,自引:0,他引:4
Parbinder S. Sahota MB ChB MRCS ; J. Lance Burn PhD ; Martin Heaton FRCS MD ; Eric Freedlander FRCS MD ; Simon K. Suvarna FRCPath ; Nicola J. Brown PhD ; Shelia Mac Neil PhD 《Wound repair and regeneration》2003,11(4):275-284
We have previously shown that reconstructed human skin engineered from autologous keratinocytes, fibroblasts, and sterilized donor allodermis stimulates angiogenesis within 5-7 days when placed on well-vascularized wound beds in nude mice. When this reconstructed skin was used clinically in more demanding wound beds, some grafts were lost, possibly due to delayed vascularization. As this reconstructed skin lacks any endothelial cells, our aim in this study was to develop an angiogenic reconstructed skin model in which to explore strategies to improve angiogenesis both in vitro and in vivo. We report that culture of small-vessel human dermal microvascular endothelial cells (HuDMECs) was achieved using magnetic beads coated with an antibody to platelet cell adhesion molecule as a means of purifying the culture. Keratinocytes, fibroblasts, and HuDMECs could be cultured from the same skin biopsy. Initial studies culturing HuDMECs and other sources of endothelial cells with the tissue-engineered skin showed that these cells were capable of slowly entering the dermis under standard culture conditions in vitro. In conclusion, this provides us with a model in which to explore strategies for improving angiogenesis in vitro and also establishes the culture methodologies for the production of reconstructed skin containing autologous keratinocytes, fibroblasts, and endothelial cells. 相似文献