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   1483篇
  免费   84篇
  国内免费   3篇
耳鼻咽喉   6篇
儿科学   31篇
妇产科学   21篇
基础医学   236篇
口腔科学   48篇
临床医学   81篇
内科学   399篇
皮肤病学   18篇
神经病学   181篇
特种医学   79篇
外科学   136篇
综合类   10篇
预防医学   57篇
眼科学   16篇
药学   111篇
肿瘤学   140篇
  2023年   12篇
  2022年   16篇
  2021年   35篇
  2020年   19篇
  2019年   22篇
  2018年   27篇
  2017年   24篇
  2016年   29篇
  2015年   28篇
  2014年   35篇
  2013年   40篇
  2012年   82篇
  2011年   81篇
  2010年   45篇
  2009年   45篇
  2008年   83篇
  2007年   89篇
  2006年   89篇
  2005年   86篇
  2004年   100篇
  2003年   97篇
  2002年   94篇
  2001年   26篇
  2000年   17篇
  1999年   25篇
  1998年   22篇
  1997年   19篇
  1996年   20篇
  1995年   20篇
  1994年   13篇
  1993年   14篇
  1992年   23篇
  1991年   17篇
  1990年   18篇
  1989年   19篇
  1988年   8篇
  1987年   17篇
  1986年   12篇
  1985年   17篇
  1984年   8篇
  1983年   15篇
  1982年   8篇
  1981年   5篇
  1980年   6篇
  1979年   9篇
  1978年   9篇
  1977年   6篇
  1976年   3篇
  1975年   3篇
  1970年   3篇
排序方式: 共有1570条查询结果,搜索用时 31 毫秒
1.
2.
3.
Gross hemorrhage is the most serious complication of anticoagulant therapy. We report the discovery and treatment of a large pseudoaneurysm of the superior gluteal artery in one patient who had been receiving oral anticoagulant therapy. We diagnosed the pseudoaneurysm by contrast-enhanced computed tomography, and embolized the artery with stainless steel coils. The exact cause of the pseudoaneurysm remains unclear, however, minor trauma appears most likely.  相似文献   
4.
Masumi Ichikawa   《Brain research》1987,420(2):253-258
The rearrangement of terminations from the bed nucleus of stria terminalis (BST) was examined in the medial amygdaloid nucleus (MAN) at 2 months following the lesion of the accessory olfactory bulb (AOB) using an electron microscopy and degeneration study. At 2 days following a BST lesion, the number of degenerating synapses was 0.7 ± 0.1 (mean±S.E.M.) per unit area (2500 μm2 in the molecular layer, and 3/0 ± 0.3 in the cellular part. At 2 months after an AOB lesion, the degenerating synapses from the AOB had completely disappeared from the MAN. The BST was then lesioned at 2 months after the AOB lesion and, 2 days following this BST lesion, the degenerating synapses were counted in MAN. The numbers observed were 3.3 ± 0.6 per unit area in the molecular layer and 4.5 ± 0.4 in the cellular part. Therefore, the number of these degenerating synapses increased significantly within the molecular layer, though, in the cellular part the number of synapses was not significantly elevated over control. No differences in postsynaptic profiles (ratio of synapses on dendritic spine to dendritic shaft) were observed after the AOB lesion. These results indicate that the BST fibers formed new synapses in the molecular layer following the denervation of AOB fibers. The possibility of new synapse formation by other afferent fibers in addition to the AOB fibers is discussed as is the relationship between lesion induced synaptic reorganization and functional recovery after injury.  相似文献   
5.
6.
The purpose of this study was to determine the relationship between segmental hyperintensity of the liver on T1-weighted images and segmental cholestasis in patients with obstructive jaundice. T1-weighted and T2-weighted MR images were obtained of 73 patients with obstructive jaundice caused by various diseases. Fat-suppressed T1-weighted images were also obtained of 10 patients. Eleven patients with segmental intra-hepatic bile duct dilatation (cholestasis) showed segmental hyperintensity on T1-weighted images and/or fat-suppressed T1-weighted images and no signal intensity difference on T2-weighted images. Sixty-two patients with widespread intrahepatic bile duct dilatation showed no intensity difference on T1-weighted and T2-weighted images (P < .01). Segmental hyperintensity on T1-weighted images was correlated with intrahepatic cholestasis.  相似文献   
7.
We raised polyclonal and monoclonal antibodies against rat recombinant HPC-1/syntaxin 1A lacking a transmembrane domain. The polyclonal antibody recognized two major bands at 35 and 40 kDa from rat brain membranes. A hybridoma clone designated 14D8, however, recognized only one band at 35 kDa. A polyclonal antibody detected recombinant syntaxin 1B, as well as HPC-1/syntaxin 1A on an immunoblot, whereas 14D8 recognized recombinant HPC-1/syntaxin 1A, but not syntaxin 1B. Therefore, 14D8 is specific for HPC-1/syntaxin 1A. Using this monoclonal antibody, we investigated the expression of HPC-1/syntaxin 1A in the rat hippocampal membranes. HPC-1/syntaxin 1A was present even in the embryonic d 19 (E19) hippocampal membranes, and it increased during the next two postnatal wk. Pyramidal cell axons were intensely stained with the 14D8 monoclonal antibody, suggesting that HPC-1/syntaxin 1A was not restricted to the presynaptic terminal. Furthermore, we investigated the phosphorylation of HPC-1/syntaxin 1A in the rat brain membranes. HPC-1/syntaxin 1A affinity-purified on a 14D8 IgG-coupled column was recognized by antiphophoserine antibody, but not by antiphosphotyrosine and phosphothreonine antibodies.  相似文献   
8.
1. In an attempt to explain the previous electrophysiological data on the ontogeny of beta-adrenergic and muscarinic cholinergic interactions on cardiac Ca2+ current, biochemical studies were performed on the ontogeny of beta-adrenoceptors, muscarinic cholinoceptors and Ca2+ channels in cardiac muscle of developing rats: 16-20 days old foetuses, 0-20 days old neonates, and 2-3 months old adults. 2. Developmental changes in cardiac beta-adrenoceptors, muscarinic cholinoceptors, and Ca2+ channels were determined with the use of specific radioligands, [3H]-dihydroalprenolol (DNA), [3H]-quinuclidinyl benzilate (QNB), and [3H]-nitrendipine (NTD), respectively. 3. The Bmax value (fmol mg-1 tissue) for [3H]-DNA binding started to increase on post-gestation day 20, reached almost its maximum level on neonatal day 6, kept almost the same level until neonatal day 20, and then decreased slightly to its adult level. 4. The Bmax value (fmol mg-1 tissue) for [3H]-QNB binding started to increase on post-gestation day 16, reached almost its maximum level on neonatal day 0, remained almost constant until neonatal day 15, and then decreased to its adult level. 5. The Bmax value (fmol mg-1 tissue) for [3H]-NTD binding increased with age between post-gestation day 18 and neonatal day 15, stayed almost constant until neonatal day 20, and then decreased to its adult level. 6. The Kd values for [3H]-DHA, [3H]-QNB, and [3H]-NTD bindings remained almost constant during the developmental period examined.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
9.
Hypertrophic scars (HS) are a consequence of abnormal wound healing. We examined fatty acids that are contained within, and participate in, every reaction through the membrane; then, we analyzed the percentage composition of the fatty acids in deepithelialized normal dermis (ND) and HS. In vivo HS samples were obtained from six patients undergoing surgical excision, and ND samples from five patients undergoing skin grafting surgery for excess. In vitro, cultured fibroblasts from HS and ND were also analyzed. The percentage composition of fatty acids extracted from all the samples was analyzed. In vivo, arachidonic acid (20:4) was significantly more abundant in HS than in ND, in the phospholipids from both whole tissue and cell membranes. In vitro, there were no significant differences among ND, HS, and 10% fetal calf serum. The results suggest that HS formation does not necessarily involve simple excess of 20:4; however, there are considerable differences in the percentage composition of 20:4 between ND and HS. Arachidonic acid probably participates in the formation and maintenance of HS, whereas in vitro cultured fibroblasts are affected largely by fetal calf serum.  相似文献   
10.
We reported a case of the biliary cystadenoma of the liver. The cystic mass had labulation and septation and showed marked hyperintensity on T1-weighted images and hypointensity on T2-weighted images; MR findings were very unusual for cystadenoma. The content of the cystic mass was jelly-like, thick mucinous fluid without intracystic hemorrhage. We concluded that these unusual signal intensities of the cyst were due to hyperproteinous mucinous fluid.  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