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   368篇
  免费   23篇
  国内免费   3篇
耳鼻咽喉   7篇
儿科学   13篇
妇产科学   2篇
基础医学   40篇
口腔科学   4篇
临床医学   16篇
内科学   122篇
神经病学   18篇
特种医学   7篇
外科学   67篇
综合类   1篇
预防医学   5篇
眼科学   58篇
药学   21篇
中国医学   1篇
肿瘤学   12篇
  2022年   3篇
  2021年   2篇
  2020年   4篇
  2019年   4篇
  2018年   9篇
  2017年   9篇
  2016年   13篇
  2015年   7篇
  2014年   10篇
  2013年   13篇
  2012年   19篇
  2011年   33篇
  2010年   18篇
  2009年   10篇
  2008年   19篇
  2007年   29篇
  2006年   26篇
  2005年   13篇
  2004年   15篇
  2003年   12篇
  2002年   12篇
  2001年   12篇
  2000年   4篇
  1999年   5篇
  1998年   5篇
  1995年   3篇
  1994年   3篇
  1993年   3篇
  1992年   2篇
  1990年   6篇
  1989年   2篇
  1988年   2篇
  1987年   5篇
  1986年   6篇
  1985年   3篇
  1984年   2篇
  1980年   2篇
  1979年   4篇
  1978年   2篇
  1977年   3篇
  1975年   2篇
  1974年   2篇
  1972年   2篇
  1971年   4篇
  1970年   5篇
  1969年   5篇
  1968年   3篇
  1967年   6篇
  1966年   3篇
  1958年   1篇
排序方式: 共有394条查询结果,搜索用时 0 毫秒
81.
82.
Squamous cell carcinoma (SCC) of the gallbladder is frequently detected at an advanced stage because of its tendency to infiltrate adjacent organs. In addition, more rapid growth of this type of carcinoma compared to that of adenocarcinoma, the most frequent subtype of gallbladder carcinoma, has been reported. Although it is not rare to find squamous cell carcinoma components in cases other than the usual adenocarcinoma of the gallbladder, these cases must be distinguished from those of pure squamous cell carcinoma, as diagnosed in the present case. Pure squamous cell carcinoma is characterized by a well-localized growth, no visceral metastasis, and a rarity or lack of lymph node metastasis, even when the tumor has grown to a large size locally. Prognosis of SCC of the gallbladder has generally been considered poor. Nevertheless, long-term survival after curative resection in patients with SCC of the gallbladder has been sporadically reported. We performed extended right hemihepatectomy with portal vein resection after portal vein embolization for a 55-year-old woman with advanced SCC of the gallbladder. The patient has not developed any signs of recurrence 40 months after the surgery. Although such radical surgery remains challenging, it may lead to a favorable outcome in selected patients with advanced SCC of the gallbladder.  相似文献   
83.

Background  

Postganglionic neurons in the sympathetic nervous system reportedly are involved in lumbar radicular pain and release norepinephrine (NE), a neurotransmitter. Increased numbers of sympathetic nerve fibers have been found in dorsal root ganglion (DRG) neurons in a root constriction model. Whether this is a reasonable model for pain, however, is unclear  相似文献   
84.
85.
In order to elucidate a relationship between newly formed micro-blood vessels in retinal tumor and blood-retina barrier, we studied light and electron microscopic and immunohistochemical findings of newly-formed micro-blood vessels in human adenovirus 12-induced retlnoblastoma-Hke tumors in rats. In contrast to other experimentally induced tumors of the central nervous system, there was no evidence of formation of Weibel-Palade bodies and endothelial gaps in this experimental model of retinoblastoma, but factor VIII related antigen was evidently demonstrated. Increased pinocytotic vesicles suggested that the vast majority of these blood vessels did not retain the normal physiological barrier functions. The basement membrane of the micro-blood vessels was poorly developed. The morphological characteristics of the micro-blood vessels of this retinoblastoma-like tumor were compared with those of human retinoblastoma and other experimentally induced tumors of the central nervous system.  相似文献   
86.
Interindividual differences in human CYP1A1 and CYP1A2 expression appear to be associated with variability in risk toward various types of environmental toxicity and cancer. These two genes are oriented head-to-head on human chromosome 15; the 23.3-kb spacer region might contain distinct regulatory regions for CYP1A1 and distinct regulatory regions for CYP1A2, or the regulatory regions for the two genes might overlap one another. From 24 unrelated subjects of five major, geographically-isolated subgroups, we resequenced both genes (all exons and all introns) plus some 3' flanking sequences and the entire spacer region (39.6 kb total); 85 SNPs were found, 49 of which were not currently in the National Center for Biotechnology Information (NCBI) database. Of the 57 double-hit SNPs, we carried out SNP-typing in 94 Africans, 96 Asians, and 83 Caucasians and found striking ethnic differences in SNP frequencies and haplotype evolution; the two CYP1A1 SNPs and the one CYP1A2 SNP that are most commonly used in epidemiological studies were shown not to be representative haplotype tag SNPs across these three human subgroups. Four BAC-transgenic mouse lines, carrying the human CYP1A2 and 15,190 bp of 5' flank, expressed only negligible basal or inducible CYP1A2 mRNA. A fifth BAC-transgenic mouse line, carrying both the human CYP1A1 and CYP1A2 genes and ample amounts of 3' flanking sequences, plus all of the spacer region--in the absence of the mouse Cyp1a1 or Cyp1a2 genes--expressed the human CYP1A1 and CYP1A2 mRNA, protein and enzyme activities in liver and nonhepatic tissues very similar to that of the mouse. Comparison of this hCYP1A1_1A2 transgenic line with hCYP1A1_1A2 lines carrying other common human haplotypes will enable us to evaluate function in human CYP1A1_CYP1A2 locus variability, with regard to toxicity and cancer caused by combustion products.  相似文献   
87.
A 52-year-old male patient with a history of total arch replacement using the elephant trunk technique for acute aortic dissection 4 years before visited our hospital with the chief complaint of persistent fever. Chest computed tomography (CT) suggested prosthetic vascular graft infection, which was treated surgically after chemotherapy. The first surgery consisted of debridement of an abscess around the vascular graft and in the aorta around the elephant trunk, and thoracic descending aorta replacement and vacuum-assisted closure (VAC) in view of the risk of bleeding from the peripheral region of the elephant trunk. One week later, omental filling was performed as the second step. This is a very rare case of aortic abscess around the elephant trunk that could successfully be managed by graft-conserving treatment.  相似文献   
88.
Bartonella quintana, known to cause various clinical symptoms, is increasingly recognized as one important cause of culture-negative endocarditis. We report a case of infectious endocarditis with B. quintana on the prosthetic valve, accompanied by proteinase 3-antineutrophil cytoplasmic antibody-positive collagen vascular disease-like symptoms 1 year earlier.  相似文献   
89.
90.
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