首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   617篇
  免费   31篇
  国内免费   4篇
耳鼻咽喉   4篇
儿科学   4篇
妇产科学   11篇
基础医学   77篇
口腔科学   61篇
临床医学   74篇
内科学   123篇
皮肤病学   13篇
神经病学   61篇
特种医学   22篇
外国民族医学   1篇
外科学   79篇
综合类   9篇
预防医学   30篇
眼科学   7篇
药学   35篇
中国医学   5篇
肿瘤学   36篇
  2024年   2篇
  2023年   8篇
  2022年   37篇
  2021年   35篇
  2020年   17篇
  2019年   30篇
  2018年   29篇
  2017年   14篇
  2016年   19篇
  2015年   27篇
  2014年   52篇
  2013年   51篇
  2012年   46篇
  2011年   37篇
  2010年   22篇
  2009年   22篇
  2008年   29篇
  2007年   30篇
  2006年   13篇
  2005年   23篇
  2004年   22篇
  2003年   21篇
  2002年   13篇
  2001年   9篇
  2000年   11篇
  1999年   9篇
  1998年   2篇
  1997年   3篇
  1996年   1篇
  1995年   2篇
  1992年   2篇
  1991年   1篇
  1986年   3篇
  1984年   1篇
  1983年   2篇
  1981年   1篇
  1977年   1篇
  1976年   1篇
  1970年   1篇
  1968年   2篇
  1967年   1篇
排序方式: 共有652条查询结果,搜索用时 15 毫秒
71.
The varus knee has been defined as a Hip-Knee-Ankle alignment of less than 180 degrees. Varus knee alignment increases the load on the medial knee and also the risk of osteoarthritis. High tibial osteotomy has been designed to modify the malalignment of varus knee. The aim of this study was to investigate the osteotomy effects on knee adduction moment (KAM) and contact forces using a musculoskeletal and subject-specific knee model. A patient with varus knee and no symptoms of any other disease or disability participated in this study. The geometry of the multibody knee model has been modified using MR images. The solutions of its finite element model have been used to determine the parameters of the multibody model. The motion data, ground reaction force and kinetic data have been applied to run the subject-specific musculoskeletal model during the stance phase of gait. After osteotomy, the adduction moment decreased, where the maximum values are comparable to other studies. The pattern of KAM did not witness any significant changes. The total and medial contact forces reduced considerably after surgery, but the lateral contact force did not significantly change. The changes in total and medial contact forces and lack of change in lateral contact force could be explained by modification of the gait pattern after surgery.  相似文献   
72.
73.
Micro‐ and nanotechnologies have emerged as potentially effective fabrication tools for addressing the challenges faced in tissue engineering and drug delivery. The ability to control and manipulate polymeric biomaterials at the micron and nanometre scale with these fabrication techniques has allowed for the creation of controlled cellular environments, engineering of functional tissues and development of better drug delivery systems. In tissue engineering, micro‐ and nanotechnologies have enabled the recapitulation of the micro‐ and nanoscale detail of the cell's environment through controlling the surface chemistry and topography of materials, generating 3D cellular scaffolds and regulating cell–cell interactions. Furthermore, these technologies have led to advances in high‐throughput screening (HTS), enabling rapid and efficient discovery of a library of materials and screening of drugs that induce cell‐specific responses. In drug delivery, controlling the size and geometry of drug carriers with micro‐ and nanotechnologies have allowed for the modulation of parametres such as bioavailability, pharmacodynamics and cell‐specific targeting. In this review, we introduce recent developments in micro‐ and nanoscale engineering of polymeric biomaterials, with an emphasis on lithographic techniques, and present an overview of their applications in tissue engineering, HTS and drug delivery. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
74.
The levels of Cd, Cu, Pb and Zn in surface sediment, soft tissue and shell of the oyster Saccostrea cucullata collected from three locations, in the intertidal zones of Lengeh Port, northern part of Persian Gulf were measured. Results indicated that there were a positive correlation across Zn (r = 0.58, p = 0.025), Cd (r = 0.74, p < 0.01) and Cu (r = 0.80, p < 0.01) levels in the soft tissue of oyster and sediment which supported this fact that the soft tissue of S. cucullata can be considered as biomonitoring agent for Cd, Zn and Cu in the Lengeh Port.  相似文献   
75.

Objectives

Atrial Septal Defect (ASD) accounts for 10% of congenital cardiac defects. The purpose of this retrospective study was to compare the short-term outcomes of surgical versus trans catheter closure of secundum atrial septal defect.

Methods

This is a single-center retrospective cohort study in patients who had surgical or trans catheter ASD closure. ASD closure outcomes such as hospital cost, length of hospital and ICU stay, residual ASDs, complications, readmission, hospital and three month mortality were recorded and compared.

Results

Between March 2010 and March 2016, total of 102 secundum ASD patients were treated in our center (71 patients surgical ASD closure and 31 patients trans catheter ASD closure). About 13.9% of patients (5/36) in the device group had failed procedural attempt for various reasons and these patients underwent surgery closure. Complete closure was observed in 26 of 31 patients (83.9%) in the device group and in 70 of 71 patients in the surgery group (98.6%). The mean length of hospital stay was 5.56?days for surgical group and 2.06?days for device group. The procedure cost for surgery was found to be 5.7% lower than trans catheter closure (patient payment). The complication rates were 18.3% for surgical group and 25.8% for the device group. Readmission after discharge was more common in surgery group (11.2 vs 6.4%). Hospital and three months mortality in both groups were zero.

Conclusions

Both trans catheter and surgical procedure are good methods of successful ASD closure. Considering that the surgical group patients were higher risk patients, mean total hospital cost of patient's procedures were significantly higher in device closure group, failed intervention rate and residual ASD were more common in device group and complications of device group were more serious; thus, appropriate patient selection is an important factor for successful device closure.  相似文献   
76.
77.
78.
The mapping of genes which affect individual cancer risk is an important but complex challenge. A surrogate assay of susceptibility to radiation-induced acute myeloid leukaemia (AML) in the mouse based on chromosomal radiosensitivity has been developed and validated. This assay was applied to the mapping of radiation-induced AML risk modifier loci by association with microsatellite markers. A region on chromosome (chr) 18 with strong association is identified and confirmed by backcross analysis. Additional loci on chrs 8 and 13 show significant association. A key candidate gene Rbbp8 on chr18 is identified. Rbbp8 is shown to be upregulated in response to X-irradiation in the AML sensitive CBA strain but not AML resistant C57BL/6 strain. This study demonstrates the strength of utilizing surrogate endpoints of cancer susceptibility in the mapping of mouse loci and identifies additional loci that may affect radiation cancer risk.  相似文献   
79.
80.
Allergic diseases are frequent in children and their prevalence and severity differ in the different regions of the world. The association between pet ownership in childhood and subsequent asthma and sensitization is very controversial.In our survey conducted with standardized method (International Study of Asthma and Allergies in Childhood), 3200 children 6-7 years old were questioned regarding asthma, allergic rhinitis and eczema. The prevalence of Attacks and shortness of breath with wheezing during last 12 months in the children who had exposure to pets in the first year of life was 34.3% 'that was less than children who had not exposure (OR=3.06, 95% confidence interval [CI] 1.14-8.21, P=0.021). Also during the past 12 months the prevalence of night dry coughs, allergic rhinitis symptoms and eczema symptoms in those who had pet exposure in the first year of their life was lower than the children did not have it. However there was no significant difference in some other symptoms of asthma in two groups.Our findings suggest that pet exposure in the first year of life can have a protective effect on asthma, allergic rhinitis and eczema.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号