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   517438篇
  免费   34275篇
  国内免费   638篇
耳鼻咽喉   6927篇
儿科学   16944篇
妇产科学   13606篇
基础医学   85722篇
口腔科学   14592篇
临床医学   44625篇
内科学   94581篇
皮肤病学   12311篇
神经病学   36499篇
特种医学   18556篇
外国民族医学   63篇
外科学   77526篇
综合类   8497篇
一般理论   121篇
预防医学   39239篇
眼科学   12225篇
药学   40828篇
中国医学   1017篇
肿瘤学   28472篇
  2018年   5080篇
  2016年   4176篇
  2015年   4650篇
  2014年   6209篇
  2013年   9723篇
  2012年   13140篇
  2011年   14536篇
  2010年   8478篇
  2009年   7905篇
  2008年   13945篇
  2007年   14920篇
  2006年   15163篇
  2005年   14595篇
  2004年   14256篇
  2003年   13566篇
  2002年   13415篇
  2001年   24117篇
  2000年   25128篇
  1999年   20608篇
  1998年   5470篇
  1997年   4736篇
  1996年   5062篇
  1995年   4643篇
  1994年   4332篇
  1992年   15756篇
  1991年   16329篇
  1990年   16457篇
  1989年   15827篇
  1988年   14594篇
  1987年   14444篇
  1986年   13611篇
  1985年   12994篇
  1984年   9642篇
  1983年   8257篇
  1982年   4566篇
  1981年   4237篇
  1979年   9437篇
  1978年   6871篇
  1977年   5785篇
  1976年   5608篇
  1975年   6404篇
  1974年   7648篇
  1973年   7135篇
  1972年   6965篇
  1971年   6692篇
  1970年   6187篇
  1969年   5899篇
  1968年   5567篇
  1967年   5020篇
  1966年   4456篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
FGFR–TACC, found in different tumor types, is characterized by the fusion of a member of fibroblast grown factor receptor (FGFR) tyrosine kinase (TK) family to a member of the transforming acidic coiled-coil (TACC) proteins. Because chromosome numerical alterations, hallmarks of FGFR–TACC fusions are present in many hematological disorders and there are no data on the prevalence, we studied a series of patients with acute myeloid leukemia and myelodysplastic syndrome who presented numerical alterations using cytogenetic traditional analysis. None of the analyzed samples showed FGFR3–TACC3 gene fusion, so screening for this mutation at diagnosis is not recommended.  相似文献   
63.
Objective:To study the effect of oral administration of dimethyl dimethoxy biphenyl dicarboxylate(DDB) on adjusting angiogeneic/inflammatory mediators and ameliorating the pathology of bones in rats with collagen-induced arthritis(CIA).Methods:Wistar rat model of CIA was set up using bovine collagen type Ⅱ.Fifty rats were divided into five groups randomly:normal,CIA model,DDB treatment,methotrexate(MTX) treatment,and combined DDB+MTX treatment.Ankle joints of rats were imaged with digital X-ray machine to show the destruction of joints.Fore and hind paw and knee joints were removed above the ankle joint then processed for haematoxylin and eosin staining.Plasma levels of vascular endothelial growth factor(VEGF),platelet derived growth factor,interleukin-8(IL-8),IL-4,tumor necrosis factor α(TNF-α),and cyclooxygenase-2(COX-2) were quantified by enzyme-linked immunosorbent assay.Nitric oxide levels were detected by Griess reagent.Results:Compared with the CIA model group,a remarkable reduction in various angiogenic(VEGF and IL-8) and inflammatory mediators(TNF-α,IL-4 and COX-2) after treatment with DDB either alone or combined with MTX(P0.05 or P0.01).Histopathological and X-ray findings were confirmatory to the observed DDB anti-arthritic effect.The DDB-treated group showed amelioration in signs of arthritis which appeared essentially similar to normal.Conclusion:Our data shed light on the therapeutic efficacy of DDB in experimental rheumatoid arthritis(RA) compared with a choice drug(MTX) and it may be offered as a second-line drug in the treatment of RA.  相似文献   
64.
65.
66.
67.

Aims

Variations of the anatomy of donor hepatic arteries increase the number of arterial anastomoses during liver transplantation and, possibly, the incidence of hepatic artery thrombosis (HAT). In this study, we describe the arterial anatomic variations in liver grafts procured and transplanted by a single center in Greece, the techniques of arterial anastomosis, and their effect on the incidence of early HAT.

Materials and Methods

From January 2013 to December 2017, the arterial anatomy of 116 grafts procured for liver transplantation were recorded, as well as the technique of arterial anastomosis and the incidence of early hepatic artery thrombosis (HAT <30 days).

Results

A single hepatic artery was recorded in 72.41% of the procured grafts, an aberrant left hepatic artery (accessory or replaced) in 18 grafts (15.52%), and an aberrant right hepatic artery (accessory or replaced) in 17 grafts (14.66%), while other variations were observed in less than 1% of the procured livers. Of the 116 primary liver transplantations, 6 patients (5.17%) developed early HAT <30 days. Two of these patients (1.72%) had 1 anastomosis of the hepatic artery and 4 (3.45%) had 2 anastomoses due to anatomic variations.

Conclusions

Anatomic variations of the hepatic artery in liver grafts is a common finding and increase the incidence of early HAT but not to a degree to make these grafts unusable.  相似文献   
68.
Pharmaceutical Chemistry Journal - Use of formylindolylacetic acid as a reagent at the stage of preparing the glycosides of bis(indolyl)furan-2,5-diones and dioxane as solvent increased yields from...  相似文献   
69.
70.
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