全文获取类型
收费全文 | 4286134篇 |
免费 | 351177篇 |
国内免费 | 15322篇 |
专业分类
耳鼻咽喉 | 61035篇 |
儿科学 | 133288篇 |
妇产科学 | 111865篇 |
基础医学 | 655600篇 |
口腔科学 | 118962篇 |
临床医学 | 388287篇 |
内科学 | 776932篇 |
皮肤病学 | 103427篇 |
神经病学 | 366651篇 |
特种医学 | 170992篇 |
外国民族医学 | 913篇 |
外科学 | 653261篇 |
综合类 | 126284篇 |
现状与发展 | 23篇 |
一般理论 | 2591篇 |
预防医学 | 362519篇 |
眼科学 | 100792篇 |
药学 | 302543篇 |
24篇 | |
中国医学 | 11376篇 |
肿瘤学 | 205268篇 |
出版年
2021年 | 55916篇 |
2020年 | 35582篇 |
2019年 | 58703篇 |
2018年 | 73385篇 |
2017年 | 56016篇 |
2016年 | 62337篇 |
2015年 | 75609篇 |
2014年 | 110391篇 |
2013年 | 175724篇 |
2012年 | 118163篇 |
2011年 | 121239篇 |
2010年 | 123051篇 |
2009年 | 126169篇 |
2008年 | 108196篇 |
2007年 | 114671篇 |
2006年 | 124148篇 |
2005年 | 119196篇 |
2004年 | 120084篇 |
2003年 | 110759篇 |
2002年 | 101318篇 |
2001年 | 154533篇 |
2000年 | 150655篇 |
1999年 | 139706篇 |
1998年 | 71295篇 |
1997年 | 67764篇 |
1996年 | 65651篇 |
1995年 | 61518篇 |
1994年 | 55595篇 |
1993年 | 51613篇 |
1992年 | 103674篇 |
1991年 | 99065篇 |
1990年 | 94144篇 |
1989年 | 91760篇 |
1988年 | 85389篇 |
1987年 | 83868篇 |
1986年 | 79546篇 |
1985年 | 77980篇 |
1984年 | 65979篇 |
1983年 | 58894篇 |
1982年 | 48152篇 |
1981年 | 44887篇 |
1980年 | 42177篇 |
1979年 | 57873篇 |
1978年 | 47044篇 |
1977年 | 41612篇 |
1976年 | 38671篇 |
1975年 | 37865篇 |
1974年 | 42448篇 |
1973年 | 40591篇 |
1972年 | 38046篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
K. Sjölund S. Fasth R. Ekman L. Hultén H. Jiborn S. Nordgren & F. Sundler 《Neurogastroenterology and motility》1997,9(3):143-150
Tissue specimens from the large bowel of 18 patients with long-standing slow transit constipation were investigated to determine the distribution and density of several neuropeptides and amines in the enteric nerve system, and also of endocrine cells in comparison to normal individuals. CGRP (calcitonin gene-related peptide), galanin, glucagon, GRP (gastrin-releasing peptide), metenkephalin, motilin, neuropeptide Y (NPY), PACAP, peptide YY (PYY), serotonin, somatostatin, substance P and VIP were studied by immunohistochemistry. Tissue concentrations of VIP, substance P and galanin were also measured by radioimmunoassay. Significantly increased VIP, SP and galanin contents were found in specimens from the ascending colon. Levels of VIP and galanin were also increased in the transverse colon. Immunohistochemistry revealed only marginal changes with an increased density of PACAP nerve fibres in the smooth muscle and of VIP and PACAP nerves in the myenteric plexus of the transverse colon. In the descending colon substance P and NPY immunoreactivity were also increased in the myenteric plexus while the density of VIP nerve fibres was reduced in the mucosa/submucosa. The frequency of PYY-containing cells and the 5-HT-containing cells in the ascending colon was significantly increased in the constipated patients. 相似文献
992.
993.
Therapeutic Consequences of Variation in Intraarterial Pressure Measurements After Iliac Angioplasty
Eric Tetteroo Cees Haaring Andries D. van Engelen Yolanda van der Graaf Willem P.T.M. Mali 《Cardiovascular and interventional radiology》1997,20(6):426-430
Purpose: To assess the accuracy of intraarterial measurement of transstenotic pressure gradients for the detection of hemodynamically
suboptimal iliac angioplasty.
Methods: In 14 patients, referred for diagnostic angiography, mean pressure gradients in the aorta and iliac artery were obtained
twice, using a double-sensor pressure catheter. Additional iliac measurements were performed during pharmacologically induced
flow augmentation. Repeatability was assessed by calculation of the mean difference plus standard deviation (MD ± SD) and
repeatability coefficient (2 × SD). These results were extrapolated to 137 iliac angioplasty procedures with secondary stenting
where there was a residual pressure gradient > 10 mmHg.
Results: MD ± SD for repeated measurements at rest and during flow augmentation were 0 ± 2 mmHg and 1 ± 3 mmHg, respectively. Repeatability
coefficients were 3 and 6 mmHg. Mean pressure gradients after hemodynamically insufficient angioplasty were 8 ± 7 mmHg at
rest and 17 ± 5 mmHg following vasodilatation. Inaccurate pressure recordings may have led to inappropriate stent placement
in less than 2.5%, and inappropriate denial of stent placement in less than 5% of the lesions.
Conclusion: Variability of intraarterial pressure measurements has little consequence in the detection of hemodynamically significant
stenosis after angioplasty.
Received: 0/00/00/Accepted: 0/00/00 相似文献
994.
995.
996.
997.
998.
999.
Emergency physicians and sexual involvement with patients: an Ontario survey 总被引:2,自引:1,他引:1 下载免费PDF全文
OBJECTIVE: To describe Ontario emergency physicians' knowledge of colleagues' sexual involvement with patients and former patients, their own personal experience of such involvement, and their attitudes toward postvisit relationships. DESIGN: Mailed survey. SETTING: Ontario. PARTICIPANTS: Emergency physicians practising in Ontario. RESULTS: Of 974 eligible mailed surveys, 599 (61.5%) were returned. Of these respondents, 52 (8.7%) reported being aware of a colleague in emergency practice who had been sexually involved with a patient or former patient. When describing their own behaviour, 37 respondents (6.2%) reported sexual involvement with a former patient. However, of this group, only 9 (25.0%) had met the patient in an emergency department. Thus, of the total number of respondents, only 1.5% (9/599) reported sexual involvement arising out of an emergency department visit. Most respondents (82.4%) agreed that it is inappropriate behaviour to ask a patient for a date after an emergency assessment and before the patient's departure, and 66.4% felt that it is inappropriate to contact the patient after discharge. However, only 10.6% believed it to be unacceptable to request a social meeting after encountering a patient previously cared for in the emergency department in a nonprofessional setting. Most respondents (96.5%) did not believe that sexual involvement could ever be therapeutic for the patient. However, only 66% felt that it was always an abuse of power and 62.4% supported zero tolerance of all sexual involvement between physicians and patients. CONCLUSIONS: Vague regulatory guidelines currently in place have failed to dispel confusion regarding what is acceptable social behaviour for physicians providing emergency care. Our results support the need for clarification, and suggest a basis for guidelines that would be acceptable to the emergency medical community: that an emergency visit should not form the basis for the initiation of personal or sexual relationships, yet neither should it preclude their development in nonmedical settings. 相似文献
1000.