全文获取类型
收费全文 | 603篇 |
免费 | 73篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 3篇 |
妇产科学 | 16篇 |
基础医学 | 65篇 |
口腔科学 | 4篇 |
临床医学 | 135篇 |
内科学 | 123篇 |
皮肤病学 | 10篇 |
神经病学 | 43篇 |
特种医学 | 23篇 |
外科学 | 122篇 |
综合类 | 7篇 |
预防医学 | 34篇 |
眼科学 | 4篇 |
药学 | 50篇 |
肿瘤学 | 26篇 |
出版年
2023年 | 6篇 |
2022年 | 11篇 |
2021年 | 18篇 |
2020年 | 13篇 |
2019年 | 7篇 |
2018年 | 22篇 |
2017年 | 18篇 |
2016年 | 24篇 |
2015年 | 38篇 |
2014年 | 65篇 |
2013年 | 62篇 |
2012年 | 18篇 |
2011年 | 23篇 |
2010年 | 36篇 |
2009年 | 50篇 |
2008年 | 17篇 |
2007年 | 16篇 |
2006年 | 11篇 |
2005年 | 14篇 |
2004年 | 7篇 |
2003年 | 15篇 |
2002年 | 10篇 |
2001年 | 14篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 18篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有681条查询结果,搜索用时 46 毫秒
671.
Stephen J. Thomas Kathleen A. Swanik Charles B. Swanik John D. Kelly IV 《Journal of Athletic Training》2010,45(1):44-50
Context:
Conditions such as labral and rotator cuff injuries have been linked with decreases in glenohumeral internal-rotation and increases in external-rotation motion. Also, decreased glenohumeral internal rotation is strongly associated with scapular dyskinesis.Objective:
To compare healthy collegiate and high school baseball players'' glenohumeral joint range of motion and scapular position.Design:
Cross-sectional study.Setting:
Institutional research laboratory.Patients or Other Participants:
Thirty-one male National Collegiate Athletic Association Division I collegiate (age = 20.23 ± 1.17 years, height = 186.24 ± 5.73 cm, mass = 92.01 ± 7.68 kg) and 21 male high school baseball players (age = 16.57 ± 0.76 years, height = 180.58 ± 6.01 cm, mass = 79.09 ± 11.51 kg).Main Outcome Measure(s):
Glenohumeral internal and external rotation and scapular upward rotation were measured with a digital inclinometer. Scapular protraction was measured with a vernier caliper. All variables except scapular upward rotation were calculated as the difference between the dominant and nondominant sides.Results:
Collegiate baseball players had more glenohumeral internal-rotation deficit (4.80°, P = .028) and total motion deficit (5.73°, P = .009) and less glenohumeral external-rotation gain (3.00°, P = .028) than high school players. Collegiate baseball players had less scapular upward rotation than high school players at the 90° (4.12°, P = .015, versus 3.00°, P = .025) and 120° (4.00°, P = .007, versus 3.40°, P = .005) positions. The scapular protraction difference was greater in collegiate baseball players than in high school players in the hands-on-hips and 90° positions (0.77 cm, P = .021, and 1.4 cm, P = .001).Conclusions:
When comparing high school with collegiate baseball players, these data suggest that glenohumeral internal-rotation deficit and scapular position change as the level of competition increases. 相似文献672.
Cisneros A Díaz-Badillo A Cruz-Martínez G Tovar R Ramírez-Palacios LR Jiménez-Rojas F Beaty B Black WC de Lourdes Muñoz M 《Archives of virology》2006,151(1):113-125
Summary. To genetically characterize dengue 2 (DEN-2) viruses in Oaxaca, Mexico, the C protein, and a portion of the prM protein genes
of 8 isolates from the 2001 DEN epidemic were sequenced. The sequences were compared to those of prototype DEN-2 viruses from
various parts of the world. Phylogenetic analysis suggested that the 2001 isolates of DEN-2 were of the American/Asian genotype
and were most similar to the Jamaica and Venezuelan isolates MARA3, LARD1996 and LARD1910. Molecular analyses confirmed the
origin of the isolates. This study indicates that DEN-2 strains of American/Asian genotype probably from Southeast Asian are
circulating in Oaxaca. 相似文献
673.
Matthew B. Morgan Barton F. Branstetter IV Jonathan Mates Paul J. Chang 《Journal of digital imaging》2006,19(1):69-75
Radiology workflows have become more distributed and complicated, and fewer tangible cues are available to the radiologist
to help optimize task prioritization and selection. Additionally, faster scanners, more detailed exams, and increased demand
for imaging services have precipitated a potential image overload for today's radiologists who are pressured to provide efficient,
quality service in less time. Radiologists are faced with the task of operating within complex systems but are lacking tools
to efficiently and effectively monitor these systems in real time. Dashboard technology can help address this deficiency in
radiology and facilitate informed, optimized decisions about workflow. Possible areas of application include workflow consolidation,
workload distribution, and urgency evaluation. Dashboards should be optimized, context-sensitive, customizable, and workflow-integrated.
Further research is needed to identify the most important dashboard metrics, determine their optimal display, and validate
their utility. 相似文献
674.
675.
Unlike extant birds and mammals, most non‐avian theropods had large muscular tails, with muscle arrangements similar to those of modern reptiles. Examination of ornithomimid and tyrannosaurid tails revealed sequential diagonal scarring on the lateral faces of four or more hemal spines that consistently correlates with the zone of the tail just anterior to the disappearance of the vertebral transverse processes. This sequential scarring is interpreted as the tapering boundary between the insertions of the M. caudofemoralis and the M. ilioischiocaudalis. Digital muscle reconstructions based on measurements of fossil specimens and dissections of modern reptiles showed that the M. caudofemoralis of many non‐avian theropods was exceptionally large. These high caudofemoral mass estimates are consistent with the elevation of the transverse processes of the caudal vertebra above the centrum, which creates an enlarged hypaxial region. Dorsally elevated transverse processes are characteristic of even primitive theropods and suggest that a large M. caudofemoralis is a basal characteristic of the group. In the genus Tyrannosaurus, the mass of the M. caudofemoralis was further increased by dorsoventrally lengthening the hemal arches. The expanded M. caudofemoralis of Tyrannosaurus may have evolved as compensation for the animal's immense size. Because the M. caudofemoralis is the primary hind limb retractor, large M. caudofemoralis masses and the resulting contractile force and torque estimates presented here indicate a sizable investment in locomotive muscle among theropods with a range of body sizes and give new evidence in favor of greater athleticism, in terms of overall cursoriality, balance, and turning agility. Anat Rec,, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
676.
677.
Caitlin I. Stoddard Kevin Sung Ednah Ojee Judith Adhiambo Emily R. Begnel Jennifer Slyker Soren Gantt Frederick A. Matsen IV John Kinuthia Dalton Wamalwa Julie Overbaugh Dara A. Lehman 《Viruses》2022,14(7)
Pre-existing antibodies that bind endemic human coronaviruses (eHCoVs) can cross-react with SARS-CoV-2, which is the betacoronavirus that causes COVID-19, but whether these responses influence SARS-CoV-2 infection is still under investigation and is particularly understudied in infants. In this study, we measured eHCoV and SARS-CoV-1 IgG antibody titers before and after SARS-CoV-2 seroconversion in a cohort of Kenyan women and their infants. Pre-existing eHCoV antibody binding titers were not consistently associated with SARS-CoV-2 seroconversion in infants or mothers; however, we observed a very modest association between pre-existing HCoV-229E antibody levels and a lack of SARS-CoV-2 seroconversion in the infants. After seroconversion to SARS-CoV-2, antibody binding titers to the endemic betacoronaviruses HCoV-OC43 and HCoV-HKU1, and the highly pathogenic betacoronavirus SARS-CoV-1, but not the endemic alphacoronaviruses HCoV-229E and HCoV-NL63, increased in the mothers. However, eHCoV antibody levels did not increase following SARS-CoV-2 seroconversion in the infants, suggesting the increase seen in the mothers was not simply due to cross-reactivity to naively generated SARS-CoV-2 antibodies. In contrast, the levels of antibodies that could bind SARS-CoV-1 increased after SARS-CoV-2 seroconversion in both the mothers and infants, both of whom were unlikely to have had a prior SARS-CoV-1 infection, supporting prior findings that SARS-CoV-2 responses cross-react with SARS-CoV-1. In summary, we found evidence of increased eHCoV antibody levels following SARS-CoV-2 seroconversion in the mothers but not the infants, suggesting eHCoV responses can be boosted by SARS-CoV-2 infection when a prior memory response has been established, and that pre-existing cross-reactive antibodies are not strongly associated with SARS-CoV-2 infection risk in mothers or infants. 相似文献
678.
Nancy L. Van Buren Srijana Rajbhandary Vanessa Reynolds Jed B. Gorlin Susan L. Stramer Edward P. Notari IV Galen Conti Louis Katz James R. Stubbs Camille M. van Buskirk Kip Kuttner Debra L. Smith Samantha G. Ngamsuntikul Suchitra Pandey Dawn C. Ward Alyssa Ziman Matthew Hiskey Mary Townsend Bruce S. Sachais 《Transfusion》2023,63(3):552-563
679.
680.