全文获取类型
收费全文 | 1448篇 |
免费 | 147篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 64篇 |
妇产科学 | 118篇 |
基础医学 | 240篇 |
口腔科学 | 19篇 |
临床医学 | 152篇 |
内科学 | 214篇 |
皮肤病学 | 19篇 |
神经病学 | 29篇 |
特种医学 | 216篇 |
外科学 | 181篇 |
综合类 | 29篇 |
预防医学 | 80篇 |
眼科学 | 10篇 |
药学 | 127篇 |
中国医学 | 4篇 |
肿瘤学 | 97篇 |
出版年
2021年 | 13篇 |
2018年 | 20篇 |
2017年 | 10篇 |
2016年 | 16篇 |
2015年 | 10篇 |
2014年 | 24篇 |
2013年 | 29篇 |
2012年 | 32篇 |
2011年 | 33篇 |
2010年 | 27篇 |
2009年 | 27篇 |
2008年 | 29篇 |
2007年 | 49篇 |
2006年 | 35篇 |
2005年 | 50篇 |
2004年 | 48篇 |
2003年 | 50篇 |
2002年 | 43篇 |
2001年 | 35篇 |
2000年 | 23篇 |
1999年 | 32篇 |
1998年 | 57篇 |
1997年 | 73篇 |
1996年 | 56篇 |
1995年 | 46篇 |
1994年 | 45篇 |
1993年 | 37篇 |
1992年 | 52篇 |
1991年 | 52篇 |
1990年 | 34篇 |
1989年 | 50篇 |
1988年 | 41篇 |
1987年 | 46篇 |
1986年 | 32篇 |
1985年 | 41篇 |
1984年 | 24篇 |
1983年 | 17篇 |
1982年 | 25篇 |
1981年 | 12篇 |
1980年 | 20篇 |
1979年 | 15篇 |
1978年 | 17篇 |
1977年 | 28篇 |
1976年 | 14篇 |
1975年 | 19篇 |
1974年 | 8篇 |
1973年 | 8篇 |
1972年 | 21篇 |
1971年 | 18篇 |
1970年 | 8篇 |
排序方式: 共有1603条查询结果,搜索用时 31 毫秒
1.
2.
Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography 总被引:2,自引:0,他引:2
The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study. 相似文献
3.
Jim Orford Lorna Templeton Asmita Patel Richard Velleman Alex Copello 《Drugs (Abingdon, England)》2007,14(2):117-135
Background: This is the second of two papers using qualitative methods from a study of an intervention for family members affected by close relatives' substance misuse problems.
Participants: 168 primary healthcare professionals (PHCPs: GPs, practice nurses and health visitors) working in general practices in two areas of England, and who took part in the study.
Data sources: Recruitment and post-session forms completed by PHCPs; telephone interviews with each PHCP 12 weeks after recruitment of a family member; interviews with PHCPs at the end of the study.
Results: At the end of the project PHCPs were overwhelmingly positive about the family member intervention and about primary care as the appropriate site. Difficulties were encountered, however, in identifying and engaging affected family members, who were often excluded on grounds of the complexity of their problems or the level of their distress. Shortage of PHCP time and other practice-related factors added to the difficulty. Active work by a PHCP was often necessary in order to make the link between presenting symptoms of physical or mental ill-health and the existence of a family substance misuse problem. When family members were identified and recruited, PHCPs were usually positive about what was achieved. Nearly all were in favour of an approach that combined giving a self-help manual with some follow-up contact with a family member as needed.
Conclusions: Taken in conjunction with statistical outcome findings of significant reductions in symptoms and changes in ways of coping, plus qualitative analysis of the views of family members, the present results encourage the view that a flexible form of this intervention should be developed for use in primary healthcare, and that further work should build on existing strengths and attempt to overcome weaknesses identified. 相似文献
Participants: 168 primary healthcare professionals (PHCPs: GPs, practice nurses and health visitors) working in general practices in two areas of England, and who took part in the study.
Data sources: Recruitment and post-session forms completed by PHCPs; telephone interviews with each PHCP 12 weeks after recruitment of a family member; interviews with PHCPs at the end of the study.
Results: At the end of the project PHCPs were overwhelmingly positive about the family member intervention and about primary care as the appropriate site. Difficulties were encountered, however, in identifying and engaging affected family members, who were often excluded on grounds of the complexity of their problems or the level of their distress. Shortage of PHCP time and other practice-related factors added to the difficulty. Active work by a PHCP was often necessary in order to make the link between presenting symptoms of physical or mental ill-health and the existence of a family substance misuse problem. When family members were identified and recruited, PHCPs were usually positive about what was achieved. Nearly all were in favour of an approach that combined giving a self-help manual with some follow-up contact with a family member as needed.
Conclusions: Taken in conjunction with statistical outcome findings of significant reductions in symptoms and changes in ways of coping, plus qualitative analysis of the views of family members, the present results encourage the view that a flexible form of this intervention should be developed for use in primary healthcare, and that further work should build on existing strengths and attempt to overcome weaknesses identified. 相似文献
4.
5.
Paediatric dacryocystorhinostomy 总被引:1,自引:0,他引:1
KN Hakin FRCS FRCOphth TJ Sullivan FRACO FRACS A Sharma FCOphth † RAN Welham FRCS FCOphth † 《Clinical & experimental ophthalmology》1994,22(4):231-235
Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease. 相似文献
6.
7.
8.
9.
Topically applied chitosan fails to improve the control of bleeding in a liver laceration model when compared to pressure alone in both normal and heparinized rats, and both chitosan and pressure alone are significantly less effective in controlling bleeding than the application of thrombin. In addition, our histologic results suggest that there may be an increased inflammatory response by the healing liver following topical application of chitosan. 相似文献
10.
Factors influencing women to undergo screening mammography 总被引:2,自引:0,他引:2