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   134215篇
  免费   11251篇
  国内免费   7045篇
耳鼻咽喉   1400篇
儿科学   2089篇
妇产科学   2792篇
基础医学   16880篇
口腔科学   2833篇
临床医学   16603篇
内科学   22034篇
皮肤病学   1459篇
神经病学   8267篇
特种医学   4639篇
外国民族医学   44篇
外科学   15212篇
综合类   16989篇
现状与发展   23篇
一般理论   28篇
预防医学   7942篇
眼科学   3513篇
药学   13458篇
  56篇
中国医学   5193篇
肿瘤学   11057篇
  2024年   283篇
  2023年   1596篇
  2022年   4011篇
  2021年   5344篇
  2020年   3744篇
  2019年   3582篇
  2018年   4166篇
  2017年   3420篇
  2016年   3329篇
  2015年   4970篇
  2014年   6337篇
  2013年   5952篇
  2012年   8815篇
  2011年   9553篇
  2010年   5792篇
  2009年   4516篇
  2008年   6432篇
  2007年   6792篇
  2006年   6545篇
  2005年   6663篇
  2004年   4696篇
  2003年   4199篇
  2002年   3686篇
  2001年   4620篇
  2000年   4736篇
  1999年   4431篇
  1998年   2215篇
  1997年   1911篇
  1996年   1614篇
  1995年   1427篇
  1994年   1219篇
  1993年   853篇
  1992年   1957篇
  1991年   1662篇
  1990年   1446篇
  1989年   1443篇
  1988年   1350篇
  1987年   1219篇
  1986年   1066篇
  1985年   904篇
  1984年   577篇
  1983年   470篇
  1982年   253篇
  1981年   225篇
  1980年   196篇
  1979年   312篇
  1978年   137篇
  1977年   137篇
  1973年   130篇
  1971年   132篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
Patients with mechanic ankle instability experience increased tibiotalar and subtalar joint laxity. However, in vivo joint kinematics in functional ankle instability (FAI) patients and lateral ankle sprain (LAS) copers, especially during dynamic activities, are poorly understood. Ten FAI patients, 10 LAS copers, and 10 healthy controls were included in this study. A dual fluoroscopic imaging system was used to analyze the tibiotalar and subtalar joint kinematics during stair descent. Five key poses of stair descent were analyzed. Kinematic data from six degrees of freedom were calculated utilizing a solid modeling software. The range of motion and joint positions in each degree of freedom were compared among the three groups. The tibiotalar joints of FAI patients and LAS copers were significantly more inverted than those of healthy controls during the foot strike (p = 0.016, = 0.264). The subtalar joints of FAI patients were significantly more anteriorly translated (pose 2, p = 0.003, = 0.352; pose 3, p < 0.001, = 0.454; pose 4, p = 0.004, = 0.334), inverted (pose 4, p = 0.027, = 0.234; pose 5,p = 0.034, = 0.221), and externally rotated (pose 4, p = 0.037, = 0.217; pose 5; p = 0.004, = 0.331) than those of healthy controls during the mid‐stance and the heel off. The FAI patients showed excessive tibiotalar inversion and subtalar joint hypermobility during stair descent. Meanwhile, the LAS copers maintained subtalar joint stability, and only showed excessive tibiotalar inversion in foot strike. These data provide insight into the mechanisms behind the development of FAI after initial LAS. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1860–1867, 2019  相似文献   
3.
Abstract

Background

Comorbidities are commonly seen in patients with coronavirus disease 2019 (COVID-19), but the clinical implication is not yet well-delineated. We aim to characterize the prevalence and clinical implications of comorbidities in patients with COVID-19.  相似文献   
4.
5.
6.
7.
Pancreatic cancer is a lethal disease characterized by early metastasis, local invasion, and resistance to conventional therapies. To understand its etiology and eventually make prevention of it possible and effective, appropriate carcinogenesis models will certainly help us understand the effects of environmental and genetic elements on pancreatic carcinogenesis. The development of new treatment strategies to control cancer metastasis is of immediate urgency. Fulfillment of this task relies on our knowledge of the cellular and molecular biology of pancreatic cancer metastasis and the availability of biologically and clinically relevant model systems. Many of the existing pancreatic cancer carcinogenesis and metastasis animal models are described in this review. The advantages and disadvantages of each model and their clinical implications are discussed, and special attention is focused on experimental therapeutic strategies targeting pancreatic cancer metastasis.  相似文献   
8.
9.
[目的]探讨负压进针在心血管内科病人的静脉输注中是否优于常规进针法.[方法]将2004年1月-2005年6月我科收治且静脉穿刺难度大的病人随机分为实验组和对照组,实验组150例应用负压进针法,对照组150例应用常规进针法,比较两组的穿刺成功率和回血率.[结果]负压进针法比常规进针法的穿刺成功率提高了12%,回血率提高了13%,两组间穿刺成功率和回血率的差异有统计学意义(P<0.01).[结论]负压进针大大提高了穿刺成功率和回血率,减少了病人的痛苦,提高护理人员的工作效率和住院病人满意度.  相似文献   
10.
OBJECTIVE: Surgical reduction and retention of apophyseal avulsion injuries at the medial epicondyle to prevent joint instability, lasting malalignment, or pseudarthrosis. INDICATIONS: Absolute: intraarticular apophyseal dislocation of the medial epicondyle, complete lesion of the ulnar nerve. Relative: dislocation of the apophysis (> 4 mm) in children > 5 years of age; the need for intervention increases in children as the degree of dislocation, age, and athletic activity increase. CONTRAINDICATIONS: Dislocation of the medial epicondyle (< or = 4 mm) in children < 5 years of age, provided the fragment location is not intraarticular. SURGICAL TECHNIQUE: Open reduction of the apophysis through a medial approach. Identification of the ulnar nerve. In young children or with small fragments fixation with Kirschner wire. Screw fixation in older children or for larger fragments. POSTOPERATIVE MANAGEMENT: Long upper-arm plaster cast until wound healing is achieved. Subsequently, upper-arm plaster cast for 3 weeks. Removal of Kirschner wires after 4-6 weeks, screw removal after 8-12 weeks. Physiotherapy only if marked reduction of elbow mobility is found 6 weeks after cast removal. RESULTS: From January 1, 1994 to December 31, 2003, 25 children with an average age of 12 years suffering from medial epicondylar avulsion fractures were operated on using open reduction and Kirschner wire fixation. An average of 3 years after the injury 14 of these children underwent follow-up examination using a procedure that took subjective, clinical and radiologic parameters into account. Two children showed a slight reduction in overall strength of the injured extremity when compared with the contralateral extremity. One child had a flexion deficit of 10 degrees, all other children showed movement limitations of < or = 5 degrees compared to the contralateral extremity. In all the cases available to follow-up, there was a slight increase in valgus alignment of the elbow joint compared with the uninjured side (3 degrees on average). All fractures consolidated within 6 weeks.  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