全文获取类型
| 收费全文 | 1073839篇 |
| 免费 | 73372篇 |
| 国内免费 | 1360篇 |
专业分类
| 耳鼻咽喉 | 15083篇 |
| 儿科学 | 34658篇 |
| 妇产科学 | 28661篇 |
| 基础医学 | 153509篇 |
| 口腔科学 | 29701篇 |
| 临床医学 | 95018篇 |
| 内科学 | 203599篇 |
| 皮肤病学 | 24398篇 |
| 神经病学 | 81675篇 |
| 特种医学 | 42973篇 |
| 外国民族医学 | 201篇 |
| 外科学 | 163074篇 |
| 综合类 | 21721篇 |
| 现状与发展 | 1篇 |
| 一般理论 | 263篇 |
| 预防医学 | 74572篇 |
| 眼科学 | 24421篇 |
| 药学 | 86214篇 |
| 7篇 | |
| 中国医学 | 2805篇 |
| 肿瘤学 | 66017篇 |
出版年
| 2019年 | 7798篇 |
| 2018年 | 11332篇 |
| 2017年 | 8922篇 |
| 2016年 | 10128篇 |
| 2015年 | 11288篇 |
| 2014年 | 15315篇 |
| 2013年 | 22309篇 |
| 2012年 | 30668篇 |
| 2011年 | 32421篇 |
| 2010年 | 19014篇 |
| 2009年 | 17858篇 |
| 2008年 | 30064篇 |
| 2007年 | 32188篇 |
| 2006年 | 32818篇 |
| 2005年 | 31172篇 |
| 2004年 | 29822篇 |
| 2003年 | 28631篇 |
| 2002年 | 27608篇 |
| 2001年 | 60090篇 |
| 2000年 | 61554篇 |
| 1999年 | 50978篇 |
| 1998年 | 12466篇 |
| 1997年 | 11011篇 |
| 1996年 | 11038篇 |
| 1995年 | 10335篇 |
| 1994年 | 9352篇 |
| 1993年 | 8874篇 |
| 1992年 | 37842篇 |
| 1991年 | 36327篇 |
| 1990年 | 35796篇 |
| 1989年 | 34339篇 |
| 1988年 | 30921篇 |
| 1987年 | 30043篇 |
| 1986年 | 28265篇 |
| 1985年 | 26487篇 |
| 1984年 | 19222篇 |
| 1983年 | 16142篇 |
| 1982年 | 8825篇 |
| 1979年 | 17009篇 |
| 1978年 | 11392篇 |
| 1977年 | 10206篇 |
| 1976年 | 8836篇 |
| 1975年 | 10060篇 |
| 1974年 | 11652篇 |
| 1973年 | 11278篇 |
| 1972年 | 10759篇 |
| 1971年 | 10097篇 |
| 1970年 | 9250篇 |
| 1969年 | 8937篇 |
| 1968年 | 7916篇 |
排序方式： 共有10000条查询结果，搜索用时 15 毫秒
101.
A. Cattapan K. Browne D.M. Halperin A. Di Castri P. Fullsack J. Graham J.M. Langley B.A. Taylor S.A. McNeil S.A. Halperin 《Vaccine》2019,37(2):289-295
Introduction/Hypothesis
Recruitment of participants into phase 1 vaccine clinical trials can be challenging since these vaccines have not been used in humans and there is no perceived benefit to the participant. Occasionally, as was the case with a phase 1 clinical trial of an Ebola vaccine in Halifax, Canada, during the 2014–2016 West African Ebola virus outbreak, recruitment is less difficult. In this study, we explored the motivations of participants in two phase 1 vaccine trials that were concurrently enrolling at the same centre and compared the motivations of participants in a high-profile phase 1 Ebola vaccine trial to those in a less high-profile phase 1 adjuvanted seasonal influenza vaccine study.Methods
An online survey which included participants’ prior experience with clinical trials, motivations to participate (including financial incentives), and demographic information was developed to examine the motivations of healthy participants in two phase 1 clinical vaccine trials conducted at the Canadian Center for Vaccinology in Halifax, Nova Scotia. Participants were invited via email to complete the online survey. Readability and clarity were assessed through pilot testing.Results
A total of 49 (55.7%) of 88 participants of the two studies completed the survey (22 [55%] of 40 participants from the Ebola vaccine study and 27 [56.3%] of 48 from the adjuvanted influenza vaccine study). Motivations that were most frequently ranked among participants' top three in both trials were (1) wanting to contribute to the health of others, (2) wanting to participate in something important, (3) wanting to contribute to the advancement of science, and (4) wanting to receive an incentive such as money or a tablet.Conclusions/Recommendations
Although media attention and financial compensation were more often cited by Ebola vaccine trial participants as a reason to participate, both altruistic and self-interested factors were important motivations for participants in their decision to participate in a phase 1 vaccine clinical trial. 相似文献102.
103.
104.
Gordon K. B. Saburov V. O. Koryakin S. N. Gulidov I. A. Fatkhudinov T. Kh. Arutyunyan I. V. Kaprin A. D. Solov’ev A. N. 《Bulletin of experimental biology and medicine》2022,173(2):281-285
Bulletin of Experimental Biology and Medicine - Fast neutron therapy, which previously has demonstrated effective results, but along with a large number of complications, can again be considered a... 相似文献
105.
106.
107.
K. Miura S. Yamaoka K. Arizono S. Ohba T. Koga T. Kawasaki N. Yoshida I. Asahina 《The British journal of oral & maxillofacial surgery》2019,57(6):529-535
Our aim was to evaluate the long-term skeletal stability of the mandible in 21 patients after orthognathic surgery with physiological positioning. The measurement points SNB, B point (X, Y), Pog (X, Y), and the angle of the ramus were measured on cephalometric photographs to assess skeletal stability preoperatively, immediately after operation, and one and two years postoperatively. In addition, we evaluated the clinical symptoms of disorders of the temporomandibular joint (TMJ). The analysis of the cephalometric photographs showed that SNB, B point X, and Pog X showed no significant differences among the postoperative time points. On the other hand, B point Y and Pog Y showed no significant differences throughout the study period. We compared the angle of the ramus before operation and two years postoperatively, and no significant difference was found. In addition, no cases showed any pathological symptoms of disorders of the TMJ two years postoperatively. The long-term stability after orthognathic surgery with physiological positioning was confirmed, and it seems to be a reliable orthognathic treatment in patients with mandibular prognathism. 相似文献
108.
Leandro Viçosa Bonetti Syed A. Hassan Sin-Tung Lau Luana T. Melo Takako Tanaka Kara K. Patterson 《The International journal of neuroscience》2019,129(2):195-203
Purpose of the study: the aim of this study was to synthesize PFC fNIRS outcomes on the effects of cognitive tasks compared to resting/baseline tasks in healthy adults from studies utilizing a pre/post design.
Material and methods: original research studies were searched from seven databases (MEDLINE, EMBASE, CENTRAL, CINAHL, SCOPUS, PEDro and PubMed). Subsequently, two independent reviewers screened the titles and abstracts followed by full-text reviews to assess the studies' eligibility.
Results: eleven studies met the inclusion criteria and had data abstracted and quality assessed. Methodology varied considerably and yet cognitive tasks resulted in the ΔO2Hb increasing in 8 of the 11 and ΔHHb decreasing in 8 of 8 studies that reported this outcome. The cognitive tasks from 10 of the 11 studies were classified as “Working Memory” and “Verbal Fluency Tasks”.
Conclusions: although, the data comparison was challenging provided the heterogeneity in methodology, the results across studies were similar. 相似文献
109.
Yinong Young-Xu Julia Thornton Snider Robertus van Aalst Salaheddin M. Mahmud Edward W. Thommes Jason K.H. Lee David P. Greenberg Ayman Chit 《Vaccine》2019,37(11):1484-1490
Background
Observational studies of the relative effectiveness of influenza vaccines are essential for public health decision making. Their estimates, however, are subject to bias due to unmeasured confounders. Instrumental variable (IV) methods can control for observed and unobserved confounders.Methods
We used linked electronic medical record databases in the Veterans Health Administration (VHA) as well as Medicare administrative files to examine the relative vaccine effectiveness (rVE) of high-dose influenza vaccine (HD) versus standard-dose influenza vaccines (SD) in preventing hospitalizations among VHA-enrolled Veterans ≥65?years of age during 5 influenza seasons (2010–2011 through 2014–2015). Using multivariable IV Poisson regression modeling to address unmeasured confounding and bias, we analyzed the data by each season and through longitudinal analysis of all five seasons.Findings
We included 3,638,924 person–influenza seasons of observation where 158,636 (4%) were among HD vaccine recipients and 3,480,288 (96%) were among SD vaccine recipients. Of the 1,728,562 Veterans, 1,702,824 (98.5%) were male and 1,299,412 (75%) were non-Hispanic white. Based on the longitudinal analysis of all five seasons, the IV-adjusted rVE estimate of HD vs. SD was 10% (95% CI, 8–12%) against all-cause hospitalization; 18% (95% CI, 15–21%) against cardiorespiratory-associated hospitalization; and 14% (95% CI, 6–22%) against influenza/pneumonia-associated hospitalization. The findings by season were similar.Interpretation
Our analysis of VHA clinical data collected from approximately 1.7 million Veterans 65?years and older during five seasons demonstrates that high-dose influenza vaccine is more effective than standard-dose influenza vaccines in preventing influenza- or pneumonia-associated hospitalizations, cardiorespiratory hospitalizations, and all-cause hospitalizations. 相似文献110.
Stress Testing Versus CT Angiography in Patients With Diabetes and Suspected Coronary Artery Disease
Abhinav Sharma Adrian Coles Nishant K. Sekaran Neha J. Pagidipati Michael T. Lu Daniel B. Mark Kerry L. Lee Hussein R. Al-Khalidi Udo Hoffmann Pamela S. Douglas 《Journal of the American College of Cardiology》2019,73(8):893-902