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   242篇
  免费   29篇
耳鼻咽喉   1篇
儿科学   1篇
妇产科学   1篇
基础医学   50篇
临床医学   53篇
内科学   57篇
皮肤病学   3篇
神经病学   6篇
特种医学   20篇
外科学   32篇
综合类   1篇
预防医学   29篇
眼科学   1篇
药学   16篇
  2023年   2篇
  2022年   5篇
  2021年   7篇
  2019年   1篇
  2018年   5篇
  2017年   1篇
  2016年   4篇
  2015年   4篇
  2014年   10篇
  2013年   6篇
  2012年   19篇
  2011年   12篇
  2010年   7篇
  2009年   5篇
  2008年   9篇
  2007年   13篇
  2006年   15篇
  2005年   18篇
  2004年   17篇
  2003年   21篇
  2002年   21篇
  2001年   1篇
  2000年   3篇
  1999年   6篇
  1998年   5篇
  1997年   1篇
  1996年   3篇
  1995年   1篇
  1994年   2篇
  1993年   1篇
  1992年   6篇
  1991年   1篇
  1990年   4篇
  1989年   5篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1983年   2篇
  1976年   2篇
  1973年   3篇
  1972年   3篇
  1971年   3篇
  1970年   3篇
  1969年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有271条查询结果,搜索用时 15 毫秒
51.
Spinal cord ischemia is a major cause of complications after operative and endovascular treatment of descending thoracic or thoracoabdominal aortic aneurysms. Prior revascularization of the intercostal artery (IA) giving rise to the artery of Adamkiewicz (AA) using an artery of the thoracic wall would preserve circulation in the AA and allow obstruction of the IA at its origin. The purpose of this study was to determine the feasibility of revascularization of the IA giving rise to the AA using three thoracic wall arteries, i.e., lateral thoracic artery, thoracodorsal artery, and descending scapular artery. A total of 16 specimens from 8 cadavers (6 men and 2 women) were prepared. The length and diameter of the thoracic wall arteries were measured to ascertain the feasibility of revascularization of the IA giving rise to the AA. In addition, 12 preoperative spinal cord arteriograms were studied. We found that revascularization of the IA giving rise to the AA using thoracic wall arteries is feasible. This technique could be used to prevent spinal cord complications after treatment of descending thoracic or thoracoabdominal aortic aneurysms.  相似文献   
52.

Purpose  

Probiotics have been shown to be able to restore a non-pathogenic digestive flora, to prevent digestive colonization by pathogenic bacteria, and to modulate immunity. The aim of this study was to assess the effects of prophylactic probiotic administration in patients ventilated for up to 2 days.  相似文献   
53.
Human pegivirus (HPgV, formerly GBV-C) is a member of the genus Pegivirus, family Flaviviridae. Despite its identification more than 20 years ago, both natural history and distribution of this viral group in human hosts remain under exploration. Analysis of HPgV genomes characterized up to now points out the scarcity of French pegivirus sequences in databases. To bring new data regarding HPgV genomic diversity, we investigated 16 French isolates obtained from hepatitis C virus-RNA and human immunodeficiency virus-RNA–positive blood donations following deep sequencing and coupled molecular protocols. Initial phylogenetic analysis of 5′-untranslated region (5′-UTR)/E2 partial sequences permitted to assign HPgV isolates to genotypes 2 (n = 15) and 1 (n = 1), with up to 16% genetic diversity observed for both regions considered. Seven nearly full-length representative genomes were characterized subsequently, with complete polyprotein coding sequences exhibiting up to 13% genetic diversity; closest nucleotide (nt) divergence with available HPgV sequences was in the range 7% to 11%. A 36 nts deletion located on the NS4B coding region (N-terminal part, 12 amino acids) of the genotype 1 HPgV genome characterized was identified, along with single nucleotide deletions in two genotype 2, 5′-UTR sequences.  相似文献   
54.
A 52-year-old man was admitted to the hospital following the development of an inoculation eschar and fever six days after being bitten by a tick. He was clinically diagnosed as suffering from rickettsiosis. Eschar biopsy cultures on standard bacteriological media remained sterile. However, inoculation of cells with the homogenized specimen by the centrifugation-shell vial technique (M. Marrero and D. Raoult, Am. J. Trop. Med. Hyg. 40:197–199, 1989) resulted in the recovery of a bacterium. Determination of the sequence of the 16S rRNA gene amplified from the organism and comparison of the sequence to other sequences identified it as a strain of Francisella tularensis, whereas the specific serology was still negative. Our findings demonstrate that the centrifugation-cell culture, which is a tool for investigation of tick-transmitted diseases, may have the potential to serve as a method for the cultural isolation of F. tularensis.  相似文献   
55.
Prospectively collected, contemporary data are lacking on how the features of infective endocarditis (IE) vary according to region. We, therefore, compared IE in Rennes, France and Khon Kaen, Thailand. Fifty-eight patients with confirmed IE were enrolled at each site during 2011 and 2012 using a common protocol. Compared with French patients, Thais had a lower median age (47 versus 70 years old; P < 0.001) and reported more animal contact (86% versus 21%; P < 0.001). There were more zoonotic infections among Thai than France patients (6 and 1 cases; P = 0.017) and fewer staphylococcal infections (4 versus 15 cases; P = 0.011). Underlying rheumatic heart disease was more prevalent in Thai than in French patients (31% and 4%; P = 0.001), whereas prosthetic heart valves were less prevalent (9% and 35%; P = 0.001). Our data strengthen previous observations that IE in the tropics has distinctive demographic characteristics, risk factors, and etiologies and underscore the need for improved prevention and control strategies.  相似文献   
56.
Acute unilateral renal failure and contralateral ureteral obstruction.   总被引:1,自引:0,他引:1  
After obstetrical surgery, a young woman developed an acute renal failure of one kidney, the other having been protected by a fortuitous ureteral ligation. The possible effects of a temporary kidney exclusion on itself and on the other kidney are discussed.  相似文献   
57.
A case of pulmonary oedema following acute pharyngo-laryngeal obstruction is reported. The case is compared with the results of the literature. The haemodynamic data suggested a non-cardiogenic effect, with low pulmonary arterial occlusion pressure of 1 mmHg and right-to-left shunting. Positive end-expiratory pressure was used with success. The mechanisms underlying such oedema are not well known, and may include disturbances in the balance of transpulmonary forces or hypoxia. However the outcome is usually favourable.  相似文献   
58.
59.
60.
We developed a new molecular tool based on rpoB gene (encoding the beta subunit of RNA polymerase) sequencing to identify streptococci. We first sequenced the complete rpoB gene for Streptococcus anginosus, S. equinus, and Abiotrophia defectiva. Sequences were aligned with these of S. pyogenes, S. agalactiae, and S. pneumoniae available in GenBank. Using an in-house analysis program (SVARAP), we identified a 740-bp variable region surrounded by conserved, 20-bp zones and, by using these conserved zones as PCR primer targets, we amplified and sequenced this variable region in an additional 30 Streptococcus, Enterococcus, Gemella, Granulicatella, and Abiotrophia species. This region exhibited 71.2 to 99.3% interspecies homology. We therefore applied our identification system by PCR amplification and sequencing to a collection of 102 streptococci and 60 bacterial isolates belonging to other genera. Amplicons were obtained in streptococci and Bacillus cereus, and sequencing allowed us to make a correct identification of streptococci. Molecular signatures were determined for the discrimination of closely related species within the S. pneumoniae-S. oralis-S. mitis group and the S. agalactiae-S. difficile group. These signatures allowed us to design a S. pneumoniae-specific PCR and sequencing primer pair.  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