全文获取类型
收费全文 | 47889篇 |
免费 | 4439篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 615篇 |
儿科学 | 1305篇 |
妇产科学 | 1324篇 |
基础医学 | 6885篇 |
口腔科学 | 1279篇 |
临床医学 | 5934篇 |
内科学 | 8403篇 |
皮肤病学 | 607篇 |
神经病学 | 3805篇 |
特种医学 | 2288篇 |
外国民族医学 | 1篇 |
外科学 | 6191篇 |
综合类 | 878篇 |
一般理论 | 23篇 |
预防医学 | 5271篇 |
眼科学 | 1092篇 |
药学 | 3563篇 |
2篇 | |
中国医学 | 61篇 |
肿瘤学 | 2878篇 |
出版年
2021年 | 658篇 |
2019年 | 644篇 |
2018年 | 764篇 |
2017年 | 633篇 |
2016年 | 622篇 |
2015年 | 719篇 |
2014年 | 959篇 |
2013年 | 1480篇 |
2012年 | 2147篇 |
2011年 | 2229篇 |
2010年 | 1220篇 |
2009年 | 1031篇 |
2008年 | 1881篇 |
2007年 | 2015篇 |
2006年 | 2015篇 |
2005年 | 2003篇 |
2004年 | 1823篇 |
2003年 | 1679篇 |
2002年 | 1707篇 |
2001年 | 1609篇 |
2000年 | 1713篇 |
1999年 | 1449篇 |
1998年 | 665篇 |
1997年 | 541篇 |
1996年 | 559篇 |
1995年 | 556篇 |
1994年 | 469篇 |
1993年 | 481篇 |
1992年 | 1266篇 |
1991年 | 1167篇 |
1990年 | 1158篇 |
1989年 | 1097篇 |
1988年 | 1012篇 |
1987年 | 1019篇 |
1986年 | 941篇 |
1985年 | 928篇 |
1984年 | 723篇 |
1983年 | 631篇 |
1982年 | 460篇 |
1981年 | 399篇 |
1980年 | 405篇 |
1979年 | 656篇 |
1978年 | 523篇 |
1977年 | 421篇 |
1976年 | 410篇 |
1975年 | 384篇 |
1974年 | 451篇 |
1973年 | 438篇 |
1972年 | 450篇 |
1971年 | 423篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
Patrick L. Jacobs Edward T. Mahoney Brad Johnson 《The journal of spinal cord medicine》2013,36(2):141-144
AbstractBackground: Accurate, reliable assessment of upper extremity muscular power in persons with paraplegia caused by spinal cord injury (SCI) would provide an objective indication of their ability to generate the forces necessary for the performance of daily activities. Wingate Anaerobic Testing (WAnT) consists of a 30-second sprint test on a cycle ergometer and has been used widely in both athletic and research settings.Purpose: To examine test-retest reliability of arm WAnT performance in persons with complete SCI and paraplegia.Methods: Forty-three participants with thoracic-level paraplegia (T2 through T12) performed 2 trials of arm WAnT with 2 to 7 days between each trial. Testing was performed using a Monarch 834E ergometer with participants seated in their wheelchairs. Participants were directed to crank at maximal pace for 30 seconds against a resistance load equivalent to 3.5% of their body mass. The SMI OptoSensor 2000 system was used to determine values of peak power (Ppeak), mean power (Pmean), minimum power, and rate of fatigue, which were compared between trials using 1-way analysis of variance for repeated measures. Coeffi cients of determination (r2) were calculated between trials for Ppeak and Pmean.Results: No significant diffe rence was found between trials for any of the power output variables. Regression analysis ind icat ed that Ppeak and Pmean were closely associated between the 2 trials (r2= 0.92 and 0.94, respectively).Conclusion: Arm WAnT is a reliable measurement tool for the assessment of upper extremity muscular power in persons with complete paraplegia. 相似文献
994.
995.
W. B. Davenport M. P. Lowe D. H. Chamberlin S. A. Kamelle P. R. Johnson M. Tyndall T. D. Tillmanns 《Journal of robotic surgery》2013,7(1):15-20
The goal of our study was to determine whether there was a difference in operative outcomes in obese versus non-obese subjects undergoing robotic-assisted hysterectomies of varying levels of difficulty. Secondarily, we sought to analyze the published outcomes between robotic-assisted hysterectomy and total laparoscopic hysterectomy in obese women at each of these levels of difficulty. This was a multi-institutional retrospective cohort study of all patients undergoing robotic-assisted hysterectomy by five gynecologic oncologists at four geographically separate locations from April 2003 to March 2008. The cohort was stratified into obese vs. non-obese groups, and defined surgical outcomes compared between groups, then further divided into three subgroups based on case difficulty level. Univariate analysis and regression analysis using SAS 9.1 was performed. We then conducted a literature search of total laparoscopic hysterectomy outcomes in obese women, dividing the resulting studies into three comparative subgroups based on surgical difficulty levels for comparison with our robotic-assisted hysterectomy results. Our cohort had 228 obese and 323 non-obese subjects. Overall, the obese group had higher blood loss and longer operative time. When further stratified by level of difficulty, obese subjects also had a higher average blood loss and longer operative time in the hysterectomy-alone subgroup. No clinically significant differences in operative outcomes exist between obese and non-obese women when utilizing the da Vinci robotic system to perform a hysterectomy, independent of case difficulty level. More prospective, controlled studies which compare the two surgical approaches of robotic-assisted and laparoscopic hysterectomy approaches are needed. 相似文献
996.
Forensic odontologists play an important role locally and nationally in assisting in the identification of the victims of mass fatality incidents, whether natural or human-made. With the recent passage of legislation by Congress identifying dentists as a first-responder resource, knowledge of their expanding role in disaster response is particularly important. The purpose of this article is to describe the forensic dental course being taught at Creighton University School of Dentistry in Omaha, Nebraska, as a model for providing a fundamental education in forensic dentistry and disaster preparedness at the predoctoral dental level. This model is designed to 1) provide students with a broad view of forensic odontology; 2) give them a functional knowledge of the tools and techniques of the modern forensic dentist; 3) provide basic knowledge of their potential role in disaster preparedness and response; and 4) encourage students to pursue further forensic education, become active in national forensic organizations, and get involved in disaster preparedness/response in their home communities following graduation. This article includes lecture topics, demonstrations, and hands-on exercises being used at Creighton to teach students the fundamentals of forensic odontology and disaster preparedness. 相似文献
997.
998.
Michael T. Compton Dawn F. Ionescu Beth Broussard Sarah L. Cristofaro Stephanie Johnson Patrick J. Haggard Amy A. Potts Claire Ramsay Wan Elaine F. Walker 《Psychiatry research》2013
Research findings are mixed as to whether or not the inability to taste phenylthiocarbamide (PTC) might represent an endophenotypic trait marker for schizophrenia. We hypothesized associations between PTC-tasting status and select clinical characteristics and trait markers in patients with psychotic disorders that, if present, would provide support for the inability to taste PTC as a trait marker. In a first-episode psychosis sample (n=93), we measured PTC tasting, family history of psychosis, age at onset of prodrome and psychosis, severity of positive and negative symptoms, global impairment in functioning, neurological soft signs, and four neurocognitive domains (verbal learning/memory, visual learning/memory, verbal working memory, and spatial working memory). Associations between PTC-non-tasting and clinical/neurocognitive variables were examined with χ2 tests and independent samples t tests. Among participants, 67.7% tasted PTC in comparison to a strip of control paper, and 25.8% were non-tasters. Tasters and non-tasters did not show statistically significant differences with respect to family history, age at onset, severity of symptoms, neurological soft signs, or the four neurocognitive domains. In conjunction with other findings, it is unlikely that PTC-non-tasting is a trait marker of schizophrenia, though a conclusive study is warranted. 相似文献
999.
Sally M. Clifford Kristelle Hudry Mayada Elsabbagh Tony Charman Mark H. Johnson 《Journal of autism and developmental disorders》2013,43(3):673-686
The current study investigated early temperament in 54 infants at familial high-risk of ASD and 50 controls. Parental report of temperament was assessed around 7, 14 and 24 months of age and diagnostic assessment was conducted at 3 years. The high-risk group showed reduced Surgency at 7 and 14 months and reduced Effortful Control at 14 and 24 months, compared to controls. High-risk infants later diagnosed with ASD were distinguished from controls by a temperament profile marked by increased Perceptual Sensitivity from the first year of life, and increased Negative Affect and reduced Cuddliness in the second year of life. Temperament may be an important construct for understanding the early infant development of ASD. 相似文献
1000.