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   43604篇
  免费   2344篇
  国内免费   151篇
耳鼻咽喉   556篇
儿科学   2766篇
妇产科学   747篇
基础医学   5075篇
口腔科学   1320篇
临床医学   3173篇
内科学   7921篇
皮肤病学   1252篇
神经病学   2679篇
特种医学   1267篇
外科学   6597篇
综合类   1335篇
一般理论   18篇
预防医学   2173篇
眼科学   1616篇
药学   4260篇
  1篇
中国医学   373篇
肿瘤学   2970篇
  2023年   352篇
  2022年   1006篇
  2021年   1729篇
  2020年   940篇
  2019年   1071篇
  2018年   1489篇
  2017年   1110篇
  2016年   1436篇
  2015年   1471篇
  2014年   2155篇
  2013年   2462篇
  2012年   3488篇
  2011年   3442篇
  2010年   2030篇
  2009年   1605篇
  2008年   2296篇
  2007年   2314篇
  2006年   2087篇
  2005年   1895篇
  2004年   1751篇
  2003年   1469篇
  2002年   1275篇
  2001年   789篇
  2000年   720篇
  1999年   617篇
  1998年   291篇
  1997年   232篇
  1996年   231篇
  1995年   196篇
  1994年   165篇
  1993年   142篇
  1992年   358篇
  1991年   344篇
  1990年   362篇
  1989年   335篇
  1988年   289篇
  1987年   246篇
  1986年   237篇
  1985年   233篇
  1984年   179篇
  1983年   125篇
  1982年   76篇
  1981年   81篇
  1980年   76篇
  1979年   114篇
  1978年   79篇
  1977年   91篇
  1976年   70篇
  1973年   64篇
  1971年   60篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
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   
62.
63.
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   
64.
65.
66.
67.
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   
68.
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   
69.
We report a seven-year-old girl who presented with a sudden tumor apoplexy due to a parasagittal hemangiopericytoma. Following tumor excision, the child was noted to have bilateral optic nerve dysfunction and progressive papilledema, despite rapid overall neurological improvement. Based on the clinical features, we feel that this case represents an unusual form of visual deterioration related to impaired CSF absorption somehow precipitated by the acute tumour apoplexy. This unusual case of blindness responded significantly to CSF shunting. Several reports exist describing raised intracranial pressure with papilledema caused by nonthrombotic sinus occlusion due to tumors in proximity to the posterior superior sagittal sinus, torcular herophili and the jugular outlet. Communicating hydrocephalus, pseudotumor syndrome or intracranial venous sinus obstruction should be considered when otherwise inexplicable visual loss coexists with optic nerve dysfunction and papilledema. We emphasize the importance of a thorough search for the cause of visual loss.  相似文献   
70.
We investigated the mechanism(s) responsible for differences in the effects of acidic pH on Ca2+ activation of the activity of adult and neonatal rat heart myofilaments. Studies on preparations of myofilaments reconstituted with adult troponin-tropomyosin (Tn-Tm) and either adult or neonatal thick filaments indicated that the difference in effect of acidic pH is related to differences in Tn-Tm and not other myofilament proteins. Immunoblotting analysis showed that development of the rat heart myofibrils is associated with isoform switching from slow skeletal TnI to cardiac TnI and from a slow mobility isoform of TnT (TnT1) to a faster Mr isoform (TnT2. Expression of slow skeletal TnI was associated with a relative insensitivity of myofilament Ca2+ activation to deactivation by acidic pH. Moreover, the effect of acidic pH on Ca2+ activation of ATPase activity of soleus myofibrils, which contain cardiac TnC and slow skeletal TnI, was essentially the same as the effect of acidic pH on rat cardiac myofibrils in the early neonatal period. Neonatal myofilaments also contained a relative abundance of a set of polypeptides copurifying with the thin filaments. We have identified these proteins as histones. The relative amount of histones among a variety of preparations from different species was not correlated with the pH sensitivity of myofibrillar Ca2+ activation. Shifts in TnT isoforms among these species were also not correlated with an altered response to acidic pH. Our data provide evidence in support of the hypothesis that the relative insensitivity of neonatal myofilament activity to acidic pH is due to the presence of slow skeletal TnI in the thin-filament regulatory complex.  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