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   41552篇
  免费   2265篇
  国内免费   159篇
耳鼻咽喉   552篇
儿科学   2709篇
妇产科学   739篇
基础医学   4967篇
口腔科学   1254篇
临床医学   2926篇
内科学   7578篇
皮肤病学   1132篇
神经病学   2472篇
特种医学   1299篇
外科学   6151篇
综合类   1344篇
一般理论   18篇
预防医学   2095篇
眼科学   1475篇
药学   4161篇
中国医学   356篇
肿瘤学   2748篇
  2023年   296篇
  2022年   702篇
  2021年   1670篇
  2020年   926篇
  2019年   1016篇
  2018年   1437篇
  2017年   1052篇
  2016年   1394篇
  2015年   1401篇
  2014年   2037篇
  2013年   2325篇
  2012年   3275篇
  2011年   3159篇
  2010年   1928篇
  2009年   1514篇
  2008年   2146篇
  2007年   2171篇
  2006年   1957篇
  2005年   1732篇
  2004年   1628篇
  2003年   1381篇
  2002年   1189篇
  2001年   819篇
  2000年   738篇
  1999年   629篇
  1998年   283篇
  1997年   222篇
  1996年   224篇
  1995年   193篇
  1994年   161篇
  1993年   136篇
  1992年   371篇
  1991年   356篇
  1990年   381篇
  1989年   357篇
  1988年   327篇
  1987年   279篇
  1986年   268篇
  1985年   268篇
  1984年   198篇
  1983年   139篇
  1982年   76篇
  1981年   78篇
  1980年   79篇
  1979年   133篇
  1978年   82篇
  1977年   99篇
  1976年   81篇
  1974年   75篇
  1971年   79篇
排序方式: 共有10000条查询结果,搜索用时 546 毫秒
71.
Defects involving the distal leg and foot are frequently encountered following various aetiological factors. Paucity of local tissue causes surgeons to resort to the retrograde peninsular flap, the cross leg flap or the free flap. With specific knowledge of perforators, the fasciocutaneous flap from the calf area can be transferred to the defect in a single stage based on skeletonised distal perforators. The surgical anatomy, flap planning and procedure have been detailed. Nineteen patients were treated during the period 1995 to 2005. The perforators were identified preoperatively by audio Doppler. The flaps were marked and dissected proximal to the defect skeletonising the distal perforators under loupe magnification and transferred to the defect in a single stage. The donor site was skin grafted. Out of 19 cases, 16 flaps healed uneventfully, one flap necrosed completely and in two cases there was marginal necrosis. The cases were followed up for 2-10 years with an average of 6 years. With detailed knowledge of perforators one can safely reconstruct distal moderate-size defects of the lower limb in a single stage, thus having the benefits of free tissue transfer without resorting to microsurgery. This technique has proved to be an advancement in the reconstructive repertoire allowing flaps of non conventional dimensions to be perfused by skeletonised perforators.  相似文献   
72.
The treatment of Legg-Calvé-Perthes disease remains controversial. The aim of this survey was to ascertain the current management strategies of this condition amongst UK paediatric orthopaedic surgeons, with particular regard to containment procedures in the fragmentation phase. Questionnaires were distributed at the January 2006 meeting of the British Society for Children’s Orthopaedic Surgery (BSCOS) and was posted to all absent members. The results showed a great deal of variability not only in the treatment of Perthes disease, but also in the decision-making processes. Consideration must now be given to a carefully constructed national multi-centre prospective randomised controlled study into the optimum management of this disease  相似文献   
73.
74.
Laparoscopic cholecystectomy for left-sided gallbladder (sinistroposition).   总被引:1,自引:0,他引:1  
Transposition of the gallbladder to the left side without situs inversus viscerum is rare. These gallbladders are situated under the left lobe of the liver between Segment III and IV or on Segment III to the left of the falciform ligament. Because routine preoperative studies may not detect the anomaly, it may provide the surgeons with an unusual surprise during laparoscopy. Awareness of the unpredictable confluence of the cystic duct into the common bile duct and selective use of intraoperative cholangiography aid in the safe laparoscopic management of this unusual problem.  相似文献   
75.
76.
77.
78.
Extrame dullary plasmacytoma of larynx is extremely rare. We report a case of multiple myeloma which presented as extrame dullary manifestation in larynx. The rarity of incidence and difficulty in diagnosis of the disease is discussed.  相似文献   
79.
We report a 40-year-old man with rheumatic heart disease who presented with abdominal pain for three weeks and hematemesis for 24 hours. CT scan showed a large splenic artery aneurysm without evidence of pancreatitis. Mycotic aneurysm due to infective endocarditis was considered and confirmed by echocardiogram, which showed aortic and mitral valve regurgitation and vegetations. He was managed successfully with coil embolization of the aneurysm and antibiotics.  相似文献   
80.
Mapping brain size and cortical gray matter changes in elderly depression.   总被引:1,自引:0,他引:1  
BACKGROUND: In elderly depression, volumetric brain imaging findings suggest abnormalities of the frontal lobe, particularly the orbitofrontal cortex, and the hippocampus. No studies to date have mapped cortical abnormalities over the entire brain surface in major depression. Here, we conducted detailed spatial analyses of brain size and gray matter within the cortical mantle in elderly patients with major depression. METHODS: High-resolution, three-dimensional, structural magnetic resonance imaging data and cortical pattern matching methods were used in 24 depressed elderly patients and 19 group-matched controls to measure local brain size and proportions of gray matter at thousands of homologous cortical surface locations. RESULTS: Prominent brain size reductions were observed in the depressed subjects in the orbitofrontal cortex bilaterally. Cortical gray matter measurements revealed significant gray matter increases in the orbitofrontal cortex, adjacent to focal trend level significant decreases of gray matter in the same region. Depressed patients also exhibited significant gray matter increases in parietal cortices, as well as the left temporal cortex. CONCLUSIONS: Complex cortical changes may contribute to the brain size reduction of the orbitofrontal cortex and to the gray matter abnormalities detected in orbitofrontal cortex and temporoparietal cortices, thereby providing a potentially new window into the pathophysiology of elderly depression.  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