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   6881篇
  免费   712篇
  国内免费   97篇
耳鼻咽喉   115篇
儿科学   184篇
妇产科学   176篇
基础医学   877篇
口腔科学   95篇
临床医学   1074篇
内科学   1283篇
皮肤病学   142篇
神经病学   592篇
特种医学   225篇
外科学   789篇
综合类   148篇
预防医学   828篇
眼科学   127篇
药学   605篇
中国医学   8篇
肿瘤学   422篇
  2021年   92篇
  2020年   63篇
  2019年   86篇
  2018年   112篇
  2017年   92篇
  2016年   86篇
  2015年   123篇
  2014年   142篇
  2013年   208篇
  2012年   282篇
  2011年   288篇
  2010年   203篇
  2009年   175篇
  2008年   252篇
  2007年   349篇
  2006年   275篇
  2005年   287篇
  2004年   241篇
  2003年   263篇
  2002年   231篇
  2001年   212篇
  2000年   244篇
  1999年   230篇
  1998年   117篇
  1997年   123篇
  1996年   100篇
  1995年   88篇
  1994年   78篇
  1993年   88篇
  1992年   175篇
  1991年   181篇
  1990年   187篇
  1989年   191篇
  1988年   168篇
  1987年   140篇
  1986年   137篇
  1985年   121篇
  1984年   82篇
  1983年   83篇
  1982年   66篇
  1981年   71篇
  1980年   64篇
  1979年   72篇
  1978年   55篇
  1977年   39篇
  1976年   44篇
  1975年   41篇
  1974年   42篇
  1973年   44篇
  1972年   48篇
排序方式: 共有7690条查询结果,搜索用时 15 毫秒
1.
2.
Pancreatic panniculitis is an uncommon condition that can occur in association with pancreatic disease. We present a case of pancreatic panniculitis in a female pancreas-kidney transplant recipient 5 months post-transplant. The patient was on standard immunosuppressive medications and had acute rejection of her renal allograft. The diagnosis of allograft pancreatitis and rejection presenting with pancreatic panniculitis was supported clinically, histopathologically and by laboratory and imaging data. This is the fourth case of pancreatic panniculitis occurring in a transplant recipient and the first in a simultaneous pancreas-kidney transplant recipient. It is also the first case associated with allograft rejection. Clinicians should be aware that pancreatic panniculitis may be a manifestation of underlying allograft pancreatic disease.  相似文献   
3.
Fibroblasts incorporated within collagen gels induce a cell-mediated contraction of the gel to form a three-dimensional, tissue-like structure by a mechanism thought to mimic wound contraction in vivo . In this study a gel contraction model was used to investigate the ability of fibroblasts derived from adult gingiva, adult skin and fetal skin to organise a collagen matrix. In addition the effects of interleukin-1β (IL-1β) on the contraction process was also investigated. Over the concentration range 5-50 U/ml, IL-1β induced a statistically significant inhibition of gel contraction in all fibroblast cell types ( P <0.05), although fetal fibroblasts appeared least responsive and gingival fibroblasts most responsive to the inhibitory effects of this cytokine. Comparison of gel contraction by the different fibroblast strains indicated that fetal and gingival fibroblasts shared similar contraction kinetics. For the adult skin fibroblasts, three of five strains studied showed significantly diminished levels of gel contraction compared to fetal and gingival cells. This apparent difference in fibroblast phenotype may, at least in part, explain the fetal-like wound healing pattern seen in the oral mucosa.  相似文献   
4.
We used vitreous surgery to remove idiopathic epiretinal membranes from the macular area in 70 consecutive cases. The abnormal tissue was successfully removed in each case. Vision improved postoperatively in 61 eyes (87%), remained unchanged in six eyes (9%), and worsened in three eyes (4%). However, at the time of final examination vision was improved in only 47 eyes (67%), primarily because of the occurrence or progression of nuclear sclerosis, which occurred in 38 of 60 phakic eyes (63%). Four preoperative factors were associated with final visual acuity of 20/60 or better: (1) initial vision of 20/100 or better, (2) shorter preoperative duration of blurred vision, (3) thin epiretinal membrane, and (4) absence of traction retinal detachment.  相似文献   
5.
6.
7.
8.
Partial N-terminal amino acid sequences for the three largest nonstructural proteins of two flaviviruses, yellow fever virus and St. Louis encephalitis virus, have been obtained. The determined sequences of these proteins exhibit significant amino acid sequence homology, and allow the positioning of these three nonstructural proteins in the polyprotein sequence deduced from the nucleotide sequence of yellow fever virus (C. M. Rice, E. M. Lenches, S. R. Eddy, S. J. Shin, R. L. Sheets, and J. H. Strauss, 1985, Science 229, 726-733.) The deduced start points support the hypothesis that the N terminus of nonstructural glycoprotein NS1 results from cleavage by signalase, whereas the N termini of NS3 and NS5 result from cleavages following double basic residues that are flanked by amino acids with short side chains.  相似文献   
9.
A. S. C. Rice  MB  BS  Registrar  F. Reynolds  MD  FFARCS 《Anaesthesia》1987,42(12):1320-1323
Forty women who underwent gynaecological surgery were randomly allocated to receive trichloroethylene, enflurane, or enflurane plus fentanyl as adjuncts to nitrous oxide/relaxant anaesthesia with controlled ventilation. No serious cardiac dysrhythmias were seen in any group. Each patient was observed postoperatively for 4 hours by a nurse blind to the technique used, and questioned at 24 hours by a similarly blinded anaesthetist. Recovery after trichloroethylene was not significantly prolonged although postoperative analgesia by visual analogue was better, opiate analgesia was required less frequently and there was less nausea and vomiting than in either of the enflurane groups. We argue for the continued use of trichloroethylene by this technique, because it costs one hundred times less than enflurane and because of the potential morbidity of the postoperative opiate dosage required after enflurane.  相似文献   
10.
Diabetes mellitus has deleterious effects on the immune system which may lead to infection that is more serious and difficult to treat. Fifteen diabetic patients with acute bacterial sinusitis are reviewed. Diabetic pathophysiology and its relationship to infection are discussed. A protocol for treatment is outlined, with emphasis on the importance of intravenous antibiotics.  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