收费全文 | 1601703篇 |
免费 | 131750篇 |
国内免费 | 2585篇 |
耳鼻咽喉 | 21664篇 |
儿科学 | 52939篇 |
妇产科学 | 46228篇 |
基础医学 | 227782篇 |
口腔科学 | 47199篇 |
临床医学 | 140912篇 |
内科学 | 314923篇 |
皮肤病学 | 34096篇 |
神经病学 | 130119篇 |
特种医学 | 64733篇 |
外国民族医学 | 474篇 |
外科学 | 243822篇 |
综合类 | 39719篇 |
现状与发展 | 3篇 |
一般理论 | 544篇 |
预防医学 | 122877篇 |
眼科学 | 36471篇 |
药学 | 121262篇 |
3篇 | |
中国医学 | 2974篇 |
肿瘤学 | 87294篇 |
2018年 | 14768篇 |
2016年 | 12898篇 |
2015年 | 15026篇 |
2014年 | 20646篇 |
2013年 | 31350篇 |
2012年 | 42546篇 |
2011年 | 44755篇 |
2010年 | 26336篇 |
2009年 | 25306篇 |
2008年 | 42996篇 |
2007年 | 45244篇 |
2006年 | 46052篇 |
2005年 | 44672篇 |
2004年 | 44089篇 |
2003年 | 42178篇 |
2002年 | 41290篇 |
2001年 | 75682篇 |
2000年 | 78327篇 |
1999年 | 66390篇 |
1998年 | 17731篇 |
1997年 | 16335篇 |
1996年 | 16314篇 |
1995年 | 16021篇 |
1994年 | 15070篇 |
1993年 | 14217篇 |
1992年 | 55427篇 |
1991年 | 53775篇 |
1990年 | 52561篇 |
1989年 | 50832篇 |
1988年 | 47221篇 |
1987年 | 46560篇 |
1986年 | 44284篇 |
1985年 | 42843篇 |
1984年 | 32033篇 |
1983年 | 27565篇 |
1982年 | 16144篇 |
1981年 | 14436篇 |
1980年 | 13564篇 |
1979年 | 30460篇 |
1978年 | 21065篇 |
1977年 | 17764篇 |
1976年 | 16694篇 |
1975年 | 17574篇 |
1974年 | 21486篇 |
1973年 | 20672篇 |
1972年 | 18853篇 |
1971年 | 17770篇 |
1970年 | 16289篇 |
1969年 | 15268篇 |
1968年 | 13949篇 |
Objectives
This study reported a hospital outbreak due to an extensively drug-resistant (XDR) OXA-72-producing strain of Acinetobacter baumannii (A. baumannii).Methods and Results
The isolates were found to be genotypically indistinguishable by whole-genome multiple locus sequence typing, and to belong to the international clonal complex CC2. One of these isolates sequentially developed a high resistance to colistin and rifampicin under treatment, as a result of mutations in genes pmrB and rpoB, respectively. The blaOXA-72 gene was localised on a 10-kb transferable plasmid, named pAB-STR-1, whose sequence is nearly identical to that of another plasmid previously found in Lithuanian strains, pAB120.Conclusion
This report highlighted the need to carefully monitor the emergence of colistin and rifampicin resistance in patients treated for infections with multidrug-resistant A. baumannii. 相似文献Patients and methods — All cemented stems with > 100 implantations were identified in the National Joint Registry of England and Wales from April 1, 2003 to September 31, 2013 and categorised as taper-slip or composite beam. Survival analyses using Kaplan–Meier and Cox regression were performed.
Results — We identified 292,987 cemented arthroplasties, of which 16% (47,586) were composite beam stems, with taper-slip stems making up the remainder (n = 245,401). There was a statistically significant increased chance of revision in the composite beam group compared with the taper-slip group (1.7% vs 1.3%, p < 0.001) but statistically no significant differences of survival estimates (p = 0.06). When the 2 groups were segregated to delineate the most implanted model in each category, the differences became more profound with the most implanted taper-slip stem (Exeter V40) showing statistically and clinically significant superior 8-year survival: 97.9% compared with 97.6% for all other taper-slip; 97.5% for the most implanted composite beam (Charnley cemented stem); and 97.7% for all other composite beam.
Interpretation — There was an increased incidence of revision for composite beam stems. The most implanted taper-slip stem demonstrated significant survival advantage vs. all other stems. 相似文献