全文获取类型
收费全文 | 691篇 |
免费 | 46篇 |
国内免费 | 12篇 |
专业分类
儿科学 | 51篇 |
妇产科学 | 3篇 |
基础医学 | 83篇 |
口腔科学 | 12篇 |
临床医学 | 93篇 |
内科学 | 123篇 |
皮肤病学 | 2篇 |
神经病学 | 35篇 |
特种医学 | 150篇 |
外科学 | 36篇 |
综合类 | 8篇 |
一般理论 | 3篇 |
预防医学 | 38篇 |
眼科学 | 6篇 |
药学 | 46篇 |
中国医学 | 2篇 |
肿瘤学 | 58篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 15篇 |
2012年 | 8篇 |
2011年 | 10篇 |
2010年 | 14篇 |
2009年 | 26篇 |
2008年 | 13篇 |
2007年 | 20篇 |
2006年 | 15篇 |
2005年 | 16篇 |
2004年 | 14篇 |
2003年 | 17篇 |
2002年 | 17篇 |
2001年 | 11篇 |
2000年 | 20篇 |
1999年 | 17篇 |
1998年 | 41篇 |
1997年 | 65篇 |
1996年 | 43篇 |
1995年 | 32篇 |
1994年 | 36篇 |
1993年 | 26篇 |
1992年 | 17篇 |
1991年 | 18篇 |
1990年 | 8篇 |
1989年 | 23篇 |
1988年 | 25篇 |
1987年 | 21篇 |
1986年 | 25篇 |
1985年 | 22篇 |
1984年 | 12篇 |
1983年 | 7篇 |
1982年 | 12篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1967年 | 1篇 |
排序方式: 共有749条查询结果,搜索用时 31 毫秒
1.
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
2.
Tsuen‐Chiuan Tsai Peter H Harasym Sylvain Coderre Kevin McLaughlin Tyrone Donnon 《Medical education》2009,43(12):1188-1197
Context The assessment of ethical problem solving in medicine has been controversial and challenging. The purposes of this study were: (i) to create a new instrument to measure doctors’ decisions on and reasoning approach towards resolving ethical problems; (ii) to evaluate the scores generated by the new instrument for their reliability and validity, and (iii) to compare doctors’ ethical reasoning abilities between countries and among medical students, residents and experts. Methods This study used 15 clinical vignettes and the think‐aloud method to identify the processes and components involved in ethical problem solving. Subjects included volunteer ethics experts, postgraduate Year 2 residents and pre‐clerkship medical students. The interview data were coded using the instruments of the decision score and Ethical Reasoning Inventory (ERI). The ERI assessed the quality of ethical reasoning for a particular case (Part I) and for an individual globally across all the vignettes (Part II). Results There were 17 Canadian and 32 Taiwanese subjects. Based on the Canadian standard, the decision scores between Taiwanese and Canadian subjects differed significantly, but made no discrimination among the three levels of expertise. Scores on the ERI Parts I and II, which reflect doctors’ reasoning quality, differed between countries and among different levels of expertise in Taiwan, providing evidence of construct validity. In addition, experts had a greater organised knowledge structure and considered more relevant variables in the process of arriving at ethical decisions than did residents or students. The reliability of ERI scores was 0.70–0.99 on Part I and 0.75–0.80 on Part II. Conclusions Expertise in solving ethical problems could not be differentiated by the decisions made, but could be differentiated according to the reasoning used to make those decisions. The difference between Taiwanese and Canadian experts suggests that cultural considerations come into play in the decisions that are made in the course of providing humane care to patients. 相似文献
3.
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
4.
5.
6.
Factors influencing women to undergo screening mammography 总被引:2,自引:0,他引:2
7.
8.
9.
10.