全文获取类型
收费全文 | 1689篇 |
免费 | 98篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 68篇 |
妇产科学 | 24篇 |
基础医学 | 184篇 |
口腔科学 | 32篇 |
临床医学 | 229篇 |
内科学 | 338篇 |
皮肤病学 | 7篇 |
神经病学 | 121篇 |
特种医学 | 58篇 |
外科学 | 283篇 |
综合类 | 17篇 |
一般理论 | 3篇 |
预防医学 | 129篇 |
眼科学 | 47篇 |
药学 | 132篇 |
中国医学 | 9篇 |
肿瘤学 | 77篇 |
出版年
2023年 | 14篇 |
2022年 | 32篇 |
2021年 | 79篇 |
2020年 | 45篇 |
2019年 | 61篇 |
2018年 | 53篇 |
2017年 | 34篇 |
2016年 | 53篇 |
2015年 | 55篇 |
2014年 | 55篇 |
2013年 | 86篇 |
2012年 | 140篇 |
2011年 | 135篇 |
2010年 | 64篇 |
2009年 | 59篇 |
2008年 | 106篇 |
2007年 | 122篇 |
2006年 | 105篇 |
2005年 | 89篇 |
2004年 | 70篇 |
2003年 | 66篇 |
2002年 | 61篇 |
2001年 | 25篇 |
2000年 | 18篇 |
1999年 | 8篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 7篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 10篇 |
1981年 | 10篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1973年 | 6篇 |
1969年 | 2篇 |
排序方式: 共有1802条查询结果,搜索用时 15 毫秒
1.
2.
Dr. Menon Raj Gopal M.Ch. AlDelamie Taha FRCS Valliathu John FRCS Zacharias Sunny FRCS Lawati Al Adil FRCS Venkatraman M.Ch. 《Indian Journal of Thoracic and Cardiovascular Surgery》2006,22(3):173-177
Background Despite improving surgical techniques, treatment of heart valve disease in children remains controversial. Somatic growth
and adequate anticoagulation are of concern when children undergo valve replacement. We conducted this study to evaluate the
performance of valves in this age group.
Methods 42 children under the age of 13 years who underwent valve replacement were included in this study. Totally, 50 valves were
implanted in 42 patients: 48 were mechanical prostheses, two were bioprosthetic both in pulmonary position. 37 (74%) valves
were implanted in mitral position, 10 (20%) in aortic position, 1 (2%) in tricuspid position and 2 (4%) in pulmonary position.
Preoperatively, 14 (33,3%) patients were in New York Heart Association (NYHA) class IV, while 27 (64.2%) were in NYHA class
III.
Results There were 2 (4.7%) hospital deaths and 2 (4.7%) late deaths while 2 (4.7%) patients were lost to follow up. The mean follow
up period was 9.4 yrs. 35 (83.3%) patients are in NYHA Class I and free of all medications except warfarin. 3 (7.1%) patients
have undergone 5 successful pregnancies. The median INR was 2.23. Major thrombo-embolic episode occurred in 1 (2.3%) patient.
Conclusions In view of the problems of sizing, anticoagulation and need for re-operation at an early age, there is a reluctance to replace
valves in children. This study shows that despite these problems, valve replacement can be undertaken safely and successfully
in children, when repair has failed or not technically feasible. 相似文献
3.
Predictors of clustering of tuberculosis in Greater Vancouver: a molecular epidemiologic study 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Canadian Medical Association journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
4.
5.
Paul C. Ivancic Manohar M. Panjabi Yasuhiro Tominaga Adam M. Pearson S. Elena Gimenez Travis G. Maak 《European spine journal》2006,15(6):891-901
Between 23 and 70% of occupants involved in frontal impacts sustain cervical spine injuries, many with neurological involvement. It has been hypothesized that cervical spinal cord compression and injury may explain the variable neurological profile described by frontal impact victims. The goals of the present study, using a biofidelic whole cervical spine model with muscle force replication, were to quantify canal pinch diameter (CPD) narrowing during frontal impact and to evaluate the potential for cord compression. The biofidelic model and a sled apparatus were used to simulate frontal impacts at 4, 6, 8, and 10 g horizontal accelerations of the T1 vertebra. The CPD was measured in the intact specimen in the neutral posture (neutral posture CPD), under static sagittal pure moments of 1.5 Nm (pre-impact CPD), during dynamic frontal impact (dynamic impact CPD), and again under static pure moments following each impact (post-impact CPD). Frontal impact caused significant (P<0.05) dynamic CPD narrowing at C0-dens, C2-C3, and C6-C7. The narrowest dynamic CPD was observed at C0-dens during the 10 g impact and was 25.9% narrower than the corresponding neutral posture CPD. Interpretation of the present results indicate that the neurological symptomatology reported by frontal impact victims is most likely not due to cervical spinal cord compression. Cord compression due to residual spinal instability is also not likely. 相似文献
6.
Predicting outbreaks: a spatial risk assessment of West Nile virus in British Columbia 总被引:1,自引:0,他引:1
Kaoru Tachiiri Brian Klinkenberg Sunny Mak Jamil Kazmi 《International journal of health geographics》2006,5(1):21-21
Background
West Nile virus (WNv) has recently emerged as a health threat to the North American population. After the initial disease outbreak in New York City in 1999, WNv has spread widely and quickly across North America to every contiguous American state and Canadian province, with the exceptions of British Columbia (BC), Prince Edward Island and Newfoundland. In this study we develop models of mosquito population dynamics for Culex tarsalis and C. pipiens, and create a spatial risk assessment of WNv prior to its arrival in BC by creating a raster-based mosquito abundance model using basic geographic and temperature data. Among the parameters included in the model are spatial factors determined from the locations of BC Centre for Disease Control mosquito traps (e.g., distance of the trap from the closest wetland or lake), while other parameters were obtained from the literature. Factors not considered in the current assessment but which could influence the results are also discussed. 相似文献7.
8.
Manohar Bance Alfredo Campos Lillian Wong David P Morris Rene van Wijhe 《Otolaryngology--head and neck surgery》2007,137(1):70-73
OBJECTIVES: The transmission of vibrations from the tympanic membrane to the stapes footplate by an ossicular reconstruction prosthesis is affected by the size of the prosthesis head. We sought to determine if augmenting or reducing the head size of prosthesis had a systematic effect on transmission of vibrations to the stapes. STUDY DESIGN: We conducted a fresh cadaveric temporal bone middle ear study. METHODS: The incus was replaced with a prosthesis using a tympanic membrane to stapes head (TASH)-type hydroxyapatite prosthesis in nine fresh cadaveric temporal bones. Three prosthesis head sizes were created: unaltered, reduced, and augmented. Stapes vibrations were measured with a laser Doppler vibrometer in response to acoustic frequency chirps at 90 dB SPL. RESULTS: All three head size prostheses resulted in smaller stapes vibrations than the intact ear. There was no difference in the vibration transmission between the three different head sizes. All prostheses showed a vibration loss of 10 to 15 dB compared to the intact ear. CONCLUSIONS AND SIGNIFICANCE: Within the range of sizes tested, prosthesis head size had little impact on vibration transmission to the stapes footplate. 相似文献
9.
10.