全文获取类型
收费全文 | 950篇 |
免费 | 40篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 46篇 |
妇产科学 | 3篇 |
基础医学 | 97篇 |
口腔科学 | 13篇 |
临床医学 | 104篇 |
内科学 | 158篇 |
皮肤病学 | 23篇 |
神经病学 | 85篇 |
特种医学 | 142篇 |
外科学 | 77篇 |
综合类 | 17篇 |
预防医学 | 34篇 |
眼科学 | 115篇 |
药学 | 86篇 |
中国医学 | 1篇 |
肿瘤学 | 28篇 |
出版年
2021年 | 5篇 |
2020年 | 7篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2015年 | 7篇 |
2014年 | 15篇 |
2013年 | 23篇 |
2012年 | 15篇 |
2011年 | 13篇 |
2010年 | 33篇 |
2009年 | 24篇 |
2008年 | 17篇 |
2007年 | 41篇 |
2006年 | 19篇 |
2005年 | 26篇 |
2004年 | 21篇 |
2003年 | 28篇 |
2002年 | 24篇 |
2001年 | 18篇 |
2000年 | 28篇 |
1999年 | 22篇 |
1998年 | 47篇 |
1997年 | 40篇 |
1996年 | 41篇 |
1995年 | 27篇 |
1994年 | 19篇 |
1993年 | 21篇 |
1992年 | 17篇 |
1991年 | 20篇 |
1990年 | 26篇 |
1989年 | 40篇 |
1988年 | 51篇 |
1987年 | 34篇 |
1986年 | 33篇 |
1985年 | 29篇 |
1984年 | 19篇 |
1983年 | 21篇 |
1982年 | 14篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 14篇 |
1976年 | 10篇 |
1975年 | 13篇 |
1974年 | 9篇 |
1973年 | 7篇 |
1972年 | 12篇 |
1971年 | 5篇 |
1970年 | 8篇 |
排序方式: 共有1035条查询结果,搜索用时 15 毫秒
61.
Based on the dissection of 30 hemi-mandibles, the authors report a study of the inferior alveolar artery in its intraosseous course. On morphologic considerations they propose a classification of the collaterals into two groups: the principal collaterals destined for the teeth and the bony alveolar tissue and the secondary collaterals destined for the sheath and the nerve as well as the bony tissue around the canal. Loss of the teeth and absorption of the alveolar bone modify the caliber of the inferior alveolar arterial axis, the distribution of its collaterals and possibly its mode of termination. These facts suggest a consideration of the vascularization of the mandible in terms of four sectors. They arrive at practical conclusions that may be drawn from this study in stomatology. 相似文献
62.
63.
A total of 140 sets of abdominal radiographs were reviewed independently by four qualified diagnostic radiologists. The degree of interobserver agreement was determined by calculating kappa values for 19 commonly used radiographic signs and diagnoses. There was fair to excellent interobserver agreement for 11 signs and diagnoses and poor agreement for the remaining eight. The signs and diagnoses for which agreement is poor cannot be considered reliable and include particularly large bowel obstruction and nonspecific gas pattern. 相似文献
64.
The effects of section separation on image contrast and calculated T1 relaxation times were investigated in healthy volunteers and a phantom using an early commercial version magnetic resonance imaging system. The effects are explained qualitatively on the basis of side lobes of excitation occurring outside the selected section resulting in reduction of the time permitted for T1 relaxation. The options for dealing with imperfect section selection, including separation of the sections (i.e., leaving gaps) and nonsequential excitation, are illustrated and the trade-offs involved in each explained. 相似文献
65.
Perforation of the inferior vena cava with aortic and vertebral penetration by a suprarenal Greenfield filter 总被引:1,自引:0,他引:1
Various complications have been reported after insertion of the Greenfield filter. This report describes an unusual complication after suprarenal placement of this filter: spreading of the filter struts, with perforation of the inferior vena cava, and penetration of the aorta and a vertebral body, followed by fracture of one of the struts. 相似文献
66.
67.
68.
69.
High-resolution MR imaging with local coils 总被引:4,自引:0,他引:4
We propose the following rules to govern the choice of local coils by the practicing radiologist: 1. Smaller coils permit smaller FOVs and better resolution. The coil should be as small as possible. 2. Match the ROS of the coil to the FOV, which will be determined by the anatomic region of interest. 3. For the case of a choice between surface coils or between a surface and a whole- or partial-volume coil, the anatomic region should lie on the high side of the crossover point. For the case of a choice among whole-volume coils, the smallest coil that surrounds the region of interest should be chosen. 4. Considerations in regard to the anatomic shape or the need to vary the position of the structure may alter the choice of coil from that obtained by S/N considerations alone. 相似文献
70.
White-matter lesions in MR imaging of clinically healthy brains of elderly subjects: possible pathologic basis 总被引:9,自引:0,他引:9
Patchy white-matter lesions occur in the magnetic resonance (MR) imaging brain studies of 20%-30% of neurologically healthy elderly subjects. To determine the frequency of histologically verifiable white-matter lesions at autopsy in such subjects the authors examined serial, microscopic, whole brain sections from 15 clinically healthy subjects aged 52-72 years. Small white-matter lesions were found in 12. In these 12, zones of atrophic perivascular demyelination were present in eight brains. These are not the familiar thrombotic, embolic, or ischemic vascular lesions that produce acute necrosis. This mild vascular insufficiency produces atrophy, which has been recognized in the pathology literature but whose clinical significance remains unknown. Other lesions seen were small vascular malformations in the centrum ovale in four brains, diverticula of the lateral ventricle extending into the white matter in three, and an isolated central white-matter infarction in one. All of these lesions are probably the basis of the patchy white-matter lesions seen on MR imaging studies in the neurologically healthy elderly population. 相似文献