全文获取类型
收费全文 | 5205717篇 |
免费 | 375451篇 |
国内免费 | 13302篇 |
专业分类
耳鼻咽喉 | 75614篇 |
儿科学 | 167490篇 |
妇产科学 | 144664篇 |
基础医学 | 722423篇 |
口腔科学 | 153845篇 |
临床医学 | 483325篇 |
内科学 | 990723篇 |
皮肤病学 | 117754篇 |
神经病学 | 429715篇 |
特种医学 | 198618篇 |
外国民族医学 | 2019篇 |
外科学 | 775668篇 |
综合类 | 124063篇 |
现状与发展 | 13篇 |
一般理论 | 2323篇 |
预防医学 | 418565篇 |
眼科学 | 125394篇 |
药学 | 384288篇 |
17篇 | |
中国医学 | 10785篇 |
肿瘤学 | 267164篇 |
出版年
2018年 | 55965篇 |
2017年 | 43026篇 |
2016年 | 48720篇 |
2015年 | 55073篇 |
2014年 | 77872篇 |
2013年 | 118880篇 |
2012年 | 157552篇 |
2011年 | 167846篇 |
2010年 | 100761篇 |
2009年 | 95537篇 |
2008年 | 156749篇 |
2007年 | 167072篇 |
2006年 | 168346篇 |
2005年 | 163656篇 |
2004年 | 157606篇 |
2003年 | 152337篇 |
2002年 | 148252篇 |
2001年 | 226153篇 |
2000年 | 232601篇 |
1999年 | 197720篇 |
1998年 | 61185篇 |
1997年 | 54167篇 |
1996年 | 52759篇 |
1995年 | 50912篇 |
1994年 | 47059篇 |
1993年 | 44189篇 |
1992年 | 156820篇 |
1991年 | 152383篇 |
1990年 | 147852篇 |
1989年 | 143245篇 |
1988年 | 132831篇 |
1987年 | 130638篇 |
1986年 | 124271篇 |
1985年 | 119475篇 |
1984年 | 90756篇 |
1983年 | 77764篇 |
1982年 | 47432篇 |
1981年 | 42648篇 |
1979年 | 84873篇 |
1978年 | 60567篇 |
1977年 | 51815篇 |
1976年 | 48269篇 |
1975年 | 51869篇 |
1974年 | 62654篇 |
1973年 | 60428篇 |
1972年 | 57247篇 |
1971年 | 53392篇 |
1970年 | 50232篇 |
1969年 | 47751篇 |
1968年 | 44409篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
15.
16.
Ian M. Windmill 《中国听力语言康复科学杂志》2015,(1)
随着婴儿潮、人口老龄化及新技术的广泛应用,人们对听力保健的需求显著增加。在美国,听力保健服务由助听设备专员、耳鼻喉科医生和听力师3类人员提供,其中听力师提供除医疗、手术外宽泛的听力保健服务。美国的听力保健服务体系及听力师教育体系经历了一个渐进的过程:20年前对从业人员的学历要求是听力学硕士,随着对服务质量要求的提高和服务范围的扩大,美国听力师逐渐要求专业博士学位(Au.D),毕业后还需3~4年的专门教育才能成为一名听力师。听力师教育有统一的标准,大学课程要通过听力教育认证委员会(the Accreditation Commission for Audiology Education, ACAE)或学术认证委员会(the Council on Academic Accreditation,CAA)的多程序严格的认证才能被承认。美国听力师需求存在巨大缺口,但是各国听力学教育标准不统一及听力师收入与教育投资不匹配,阻碍了更多的人进入这一领域。美国试图通过改变教育模式,降低教育成本及革新教学方法等改善听力师教育状况,但是听力师教育体系远未完善。 相似文献
17.
18.
Accuracy and Precision of Acetabular Component Placement With Imageless Navigation in Obese Patients
Leonard T. Buller Alexander S. McLawhorn Jose A. Romero Peter K. Sculco David J. Mayman 《The Journal of arthroplasty》2019,34(4):693-699
Background
Obesity is a risk factor for acetabular component malposition when total hip arthroplasty is performed with manual techniques. The utility of imageless navigation in obese patients remains unknown. This study compared the accuracy and precision of imageless navigation for component orientation between obese and nonobese patients.Methods
A total of 459 total hip arthroplasties performed for osteoarthritis using imageless navigation were reviewed from a single surgeon’s institutional review board–approved database. Einzel-Bild-Roentgen Analyse determined component orientation on 6-week postoperative anteroposterior radiographs. Mean orientation error (accuracy) and precision were compared between obese (body mass index ≥ 30 kg/m2) and nonobese patients. Regression analysis evaluated the influence of obesity on component position.Results
The difference in mean inclination and anteversion between obese and nonobese groups was 1.1° (43.0° ± 3.5°; range, 35.8°-57.8° vs 41.9° ± 4.4°; range, 33.0°-57.1° and 24.9° ± 6.3°; range, 14.2°-44.3° vs 23.8° ± 6.6°; range, 7.0°-38.6°, respectively). Inclination precision was better for nonobese patients. No difference in inclination accuracy or anteversion accuracy or precision was detected between groups. And 83% of components were placed within the target range. There was no relationship between obesity (dichotomized) and component placement outside the target ranges for inclination, anteversion, or both. As a continuous variable, increased body mass index correlated with higher odds of inclination outside the target zone (odds ratio, 1.06; P = .001).Conclusion
Using imageless navigation, inclination orientation was less precise for obese patients, but the observed difference is likely not clinically relevant. Accurate superficial registration of landmarks in obese patients is achievable, and the use of imageless navigation similarly improves acetabular component positioning in obese and nonobese patients.Level of Evidence
Therapeutic Level IV. 相似文献19.
Stephan Koter Tina U. Cohnert Korbinian B. Hindermayr Jörg Lindenmann Maximilian Brückner Wolfgang K. Oswald Georg Werkgartner Doris Wagner 《Journal of vascular surgery》2019,69(4):1227-1232
Objective
Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.Methods
Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.Results
We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.Conclusions
Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients. 相似文献20.
Julia H. Vermylen Gordon J. Wood Elaine R. Cohen Jeffrey H. Barsuk William C. McGaghie Diane B. Wayne 《Journal of pain and symptom management》2019,57(3):682-687