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   13770篇
  免费   944篇
  国内免费   161篇
耳鼻咽喉   187篇
儿科学   348篇
妇产科学   246篇
基础医学   1931篇
口腔科学   1205篇
临床医学   1170篇
内科学   3093篇
皮肤病学   387篇
神经病学   910篇
特种医学   721篇
外国民族医学   2篇
外科学   1480篇
综合类   107篇
一般理论   6篇
预防医学   1338篇
眼科学   214篇
药学   936篇
中国医学   83篇
肿瘤学   511篇
  2023年   113篇
  2022年   290篇
  2021年   456篇
  2020年   321篇
  2019年   438篇
  2018年   494篇
  2017年   342篇
  2016年   399篇
  2015年   415篇
  2014年   567篇
  2013年   709篇
  2012年   973篇
  2011年   1052篇
  2010年   631篇
  2009年   514篇
  2008年   705篇
  2007年   802篇
  2006年   615篇
  2005年   618篇
  2004年   474篇
  2003年   398篇
  2002年   378篇
  2001年   292篇
  2000年   299篇
  1999年   226篇
  1998年   167篇
  1997年   158篇
  1996年   162篇
  1995年   117篇
  1994年   109篇
  1993年   102篇
  1992年   97篇
  1991年   112篇
  1990年   112篇
  1989年   106篇
  1988年   99篇
  1987年   121篇
  1986年   87篇
  1985年   98篇
  1984年   76篇
  1983年   58篇
  1982年   61篇
  1981年   38篇
  1980年   51篇
  1979年   41篇
  1978年   39篇
  1977年   35篇
  1976年   43篇
  1975年   29篇
  1967年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
Arterial occlusion with subsequent amputation of extremities is a rare manifestation of systemic lupus erythematosus (SLE). It may be caused by local arteritis and/or thrombosis. We describe the clinical and laboratory manifestations and treatment administered to six SLE patients who developed peripheral arterial necrosis necessitating amputation of extremities secondary to the arterial occlusion. All patients were female, with ages ranging from 16 to 65 years. Arterial occlusion took place in the initial months of disease (median: 7 months). Only one of five patients tested for antiphospholipid antibodies had these antibodies who also had vasculitis and thrombosis in a histopathological study. Most patients presented a very benign outcome after the amputation of extremities and stayed in remission for several years. The satisfactory outcome of most patients after the vascular phenomenon allows us to consider the possibility that such a complication could be, for unknown reasons, a marker for good prognosis in SLE or, alternatively, that the aggressive therapy administrated for patients with this complication at the beginning of the disease could recover the balance of the immune system, avoiding future relapses.  相似文献   
996.
Narcolepsy is a chronic sleep disorder. It is linked to the HLA-DQB1*0602 allele. A recent report established a genetic linkage between narcolepsy and the chromosomal region 4p13-q21 that contains the Clock gene. We studied two SNPs in the Clock gene aiming to find any association with narcolepsy. We did not find differences in genetic frequencies in the patients group. We concluded that these two SNPs are not associated with narcolepsy.  相似文献   
997.
This is a factorial (2 x 2 x 2) spatial memory and cholinergic parameters study in which the factors are chronic ethanol, thiamine deficiency and naivety in Morris water maze task. Both learning and retention of the spatial version of the water maze were assessed. To assess retrograde retention of spatial information, half of the rats were pre-trained on the maze before the treatment manipulations of pyrithiamine (PT)-induced thiamine deficiency and post-tested after treatment (pre-trained group). The other half of the animals was only trained after treatment to assess anterograde amnesia (post-trained group). Thiamine deficiency, associated to chronic ethanol treatment, had a significant deleterious effect on spatial memory performance of post-trained animals. The biochemical data revealed that chronic ethanol treatment reduced acetylcholinesterase (AChE) activity in the hippocampus while leaving the neocortex unchanged, whereas thiamine deficiency reduced both cortical and hippocampal AChE activity. Regarding basal and stimulated cortical acetylcholine (ACh) release, both chronic ethanol and thiamine deficiency treatments had significant main effects. Significant correlations were found between both cortical and hippocampal AChE activity and behaviour parameters for pre-trained but not for post-trained animals. Also for ACh release, the correlation found was significant only for pre-trained animals. These biochemical parameters were decreased by thiamine deficiency and chronic ethanol treatment, both in pre-trained and post-trained animals. But the correlation with the behavioural parameters was observed only for pre-trained animals, that is, those that were retrained and assessed for retrograde retention.  相似文献   
998.
OBJECTIVE: Searching usefulness of computed tomography with three dimensional reconstruction in planning accurate cranial approaches to treat subcortical lesions. METHOD: Eight patients with neoplastic subcortical convexity-based lesions were surgically treated following spatial coordination obtained with three dimensional computed tomography reconstruction (CT 3D). RESULTS: Accurate approaches were accomplished, allowing a safe and optimized removal of neoplasms in all cases. CONCLUSION: The study manifests the benefits of CT 3D in planning suitable craniotomies, avoiding incongruous approaches.  相似文献   
999.
1000.
OBJECTIVE: This article reviews various CT protocols for appendicitis, identifies key CT findings for diagnosing appendicitis, discusses unusual manifestations such as chronic and recurrent appendicitis, and profiles imaging features that differentiate appendicitis from other inflammatory and neoplastic ileocecal conditions. Patients were studied with helical CT. CONCLUSION: CT is a highly accurate, noninvasive test for appendicitis, but the optimal CT technique is controversial. Major complications of appendicitis (perforation, abscess formation, peritonitis, bowel obstruction, septic seeding of mesenteric vessels, gangrenous appendicitis) and their management are discussed. Abdominal CT is a well-established technique in the study of acute abdominal pain and has shown high sensitivity and specificity for diagnosing and differentiating appendicitis, providing an accurate diagnosis in the early stages of disease.  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