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   134084篇
  免费   7702篇
  国内免费   1158篇
耳鼻咽喉   2150篇
儿科学   2025篇
妇产科学   2004篇
基础医学   21386篇
口腔科学   3248篇
临床医学   12395篇
内科学   23891篇
皮肤病学   4359篇
神经病学   10788篇
特种医学   7669篇
外科学   17722篇
综合类   562篇
现状与发展   3篇
一般理论   33篇
预防医学   6957篇
眼科学   3382篇
药学   12110篇
中国医学   1540篇
肿瘤学   10720篇
  2023年   968篇
  2022年   2914篇
  2021年   4703篇
  2020年   2242篇
  2019年   3152篇
  2018年   3954篇
  2017年   3210篇
  2016年   4191篇
  2015年   5842篇
  2014年   6896篇
  2013年   8041篇
  2012年   11988篇
  2011年   11480篇
  2010年   6626篇
  2009年   5666篇
  2008年   7990篇
  2007年   7556篇
  2006年   6794篇
  2005年   6262篇
  2004年   5411篇
  2003年   4747篇
  2002年   4054篇
  2001年   3073篇
  2000年   2815篇
  1999年   2160篇
  1998年   926篇
  1997年   689篇
  1996年   524篇
  1995年   467篇
  1994年   414篇
  1993年   347篇
  1992年   752篇
  1991年   708篇
  1990年   645篇
  1989年   559篇
  1988年   472篇
  1987年   473篇
  1986年   340篇
  1985年   368篇
  1984年   273篇
  1983年   191篇
  1982年   137篇
  1981年   172篇
  1980年   130篇
  1979年   224篇
  1978年   164篇
  1976年   134篇
  1975年   120篇
  1974年   141篇
  1973年   120篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.

Introduction

We studied the incidence of vesicoureteral reflux (VUR) in the graft kidney and its effect on the occurrence of urinary tract infection (UTI) and long-term graft function.

Methods

We performed a retrospective analysis of 64 adult kidney transplant recipients based upon voiding cystourethrography at 12 months post-transplantation. Patients underwent analysis of survival, incidence of UTIs beyond 1 year, and graft function.

Results

Thirty-seven male and 27 female patients in the study populations showed a mean age 42 years. VUR in the transplanted kidney at 12 months post-transplant occurred among 78.1% (50/64) of subjects: grade I (n = 6), grade II (n = 30), or grade III (n = 14) reflux. Patients followed for a median 61 months (range 44–74s) showed 11 cases of UTIs in 9 subjects. There were no significant differences in clinical characteristics or incidence of, UTIs according to the presence or severity of VUR (P = .81) or the Serum creatinine and estimated glomerular filtration rate values at 12, 36, 48, or 60 months post-transplantation.

Conclusions

VUR present in 78.1% of patients after kidney transplantation affected neither graft functions or graft survival. The incidence of UTI did not differ according to the presence of VUR.  相似文献   
992.
993.

Background

The purpose of this study is to report a modified transtibial technique to approach the center of anatomical femoral footprint in anterior cruciate ligament (ACL) reconstruction and to investigate the accurate femoral tunnel position with 3-dimensional computed tomography (3D-CT) and radiography after reconstruction.

Methods

From December 2010 to October 2011, we evaluated 98 patients who underwent primary ACL reconstruction using a modified transtibial technique to approach the center of anatomical femoral footprint in single bundle ACL reconstruction with hamstring autograft. Their femoral tunnel positions were investigated with 3D-CT and radiography postoperatively. Femoral tunnel angle was measured on the postoperative anteroposterior (AP) radiograph and the center of the femoral tunnel aperture on the lateral femoral condyle was assessed with 3D-CT according to the quadrant method by two orthopedic surgeons.

Results

According to the quadrant method with 3D-CT, the femoral tunnel was measured at a mean of 32.94% ± 5.16% from the proximal condylar surface (parallel to the Blumensaat line) and 41.89% ± 5.58% from the notch roof (perpendicular to the Blumensaat line) with good interobserver (intraclass correlation coefficients [ICC], 0.766 and 0.793, respectively) and intraobserver reliability (ICC, 0.875 and 0.893, respectively). According to the radiographic measurement on the AP view, the femoral tunnel angles averaged 50.43° ± 7.04° (ICC, 0.783 and 0.911, respectively).

Conclusions

Our modified transtibial technique is anticipated to provide more anatomical placement of the femoral tunnel during ACL reconstruction than the former traditional transtibial techniques.  相似文献   
994.
995.
996.
Introduction: We sought to the ideal sites for botulinum toxin injection by examining the intramuscular nerve patterns of the ankle invertors. Methods: A modified Sihler method was performed on the flexor hallucis longus, tibialis posterior, and flexor digitorum longus muscles (10 specimens each). The muscle origins, nerve entry points, and intramuscular arborization areas were measured as a percentage of the total distance from the most prominent point of the lateral malleolus (0%) to the fibular head (100%). Results: Intramuscular arborization patterns were observed at 20–50% for the flexor hallucis longus, 70–80% for the tibialis posterior, and 30–40% for the flexor digitorum longus. Conclusions: These findings suggest that treatment of muscle spasticity of the ankle invertors involves botulinum toxin injections in specific areas. These areas, corresponding to the areas of maximum arborization, are recommended as the most effective and safest points for injection. Muscle Nerve 53 : 742–747, 2016  相似文献   
997.
998.
Our prior research showed that faces and bodies activate overlapping regions of the ventral occipitotemporal cortex (VOTC). However, faces and bodies were nonetheless discriminable in these same overlapping regions when their spatial patterns of activity were classified using multivoxel pattern analysis (MVPA). Here we investigated whether these spatial patterns and their time courses were influenced by different categorization tasks. Participants viewed pictures of faces or headless bodies depicting a happy or fearful emotion. In one task, they categorized the picture as a face or a body regardless of emotion. In the other task, they categorized the emotion regardless of whether it was depicted by a face or body. Using a classifier trained on independent data, we found higher face–body classification accuracy for the emotion categorization task. The classifier was applied to each post-stimulus time-point to characterize the temporal course of classification. Accuracy initially rose equivalently above chance for both tasks, but then increased over a longer duration when participants categorized emotions. Thus, the temporal course of pattern differences between faces and bodies in VOTC was modulated by the behavioral goal of the observer, suggesting the top-down modulatory effect of task context on the category-selectivity activity in the VOTC.  相似文献   
999.
1000.
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