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   343273篇
  免费   35271篇
  国内免费   122篇
  378666篇
  2018年   3137篇
  2016年   4325篇
  2015年   5475篇
  2014年   6540篇
  2013年   9039篇
  2012年   10187篇
  2011年   10579篇
  2010年   7252篇
  2009年   6795篇
  2008年   9715篇
  2007年   10136篇
  2006年   9445篇
  2005年   9042篇
  2004年   9051篇
  2003年   8543篇
  2002年   8361篇
  2001年   13893篇
  2000年   14070篇
  1999年   11085篇
  1998年   4000篇
  1997年   4243篇
  1996年   3919篇
  1995年   3668篇
  1994年   3545篇
  1993年   3606篇
  1992年   9311篇
  1991年   9256篇
  1990年   9085篇
  1989年   8711篇
  1988年   8321篇
  1987年   8038篇
  1986年   7411篇
  1985年   7370篇
  1984年   6243篇
  1983年   5297篇
  1982年   4112篇
  1981年   3669篇
  1980年   3607篇
  1979年   5946篇
  1978年   4662篇
  1977年   4286篇
  1976年   4127篇
  1975年   4439篇
  1974年   5036篇
  1973年   4939篇
  1972年   4637篇
  1971年   4237篇
  1970年   3717篇
  1969年   3666篇
  1968年   3506篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Introduction

Although anticoagulation therapy is mandated after implantation of a left ventricular assist device (LVAD), postoperative bleedings and reoperations occur relatively frequently and are associated with worse outcomes. We evaluated the use of a conservative postoperative anticoagulation protocol in patients implanted with a HeartMate 3 (HM3) LVAD.

Methods

In a single-centre retrospective analysis of postoperative outcomes after HM3 LVAD implantation, a standard (old) anticoagulation protocol (i.e. early, full-dose anticoagulation with low-molecular weight heparin and overlapping vitamin K antagonist) was compared with a new conservative anticoagulation protocol (i.e. slow initiation of vitamin K antagonists without overlapping heparin). Main outcomes were changes in international normalised ratio (INR), lactate dehydrogenase (LDH), bleeding and/or tamponade events requiring reoperation, length of stay and adverse events.

Results

In total, 73 patients (48 in old vs 25 in new protocol group) were evaluated. Mean age was 56 years (standard deviation 13) and most patients (78%) were males. Changes in INR and LDH in the first 14 days were similar in both groups (p?=?0.50 and p?=?0.997 for interaction, respectively). Number of bleeding/tamponade events requiring reoperation was lower in the new than in the old protocol group (4% vs 33%, p?=?0.005). Postoperative 30-day mortality was similar, and we observed no thromboembolic events. Median (25th–75th percentiles) total length of postoperative hospital stay (27 (25–41) vs 21 (19–27) days, p?<?0.001) and length of intensive care unit stay (5 (2–9) vs 2 (2–5) days, p?=?0.022) were significantly shorter in the new protocol group.

Conclusion

These retrospective data suggest that conservative slow initiation of anticoagulation therapy after HM3 LVAD implantation is associated with less bleeding/tamponade events requiring reoperation, a similar safety profile and a shorter duration of stay than the currently advised standard anticoagulation protocol.

  相似文献   
992.
Plant and Soil - Root residues are an important factor influencing soil phosphorus (P) availability for crop uptake, but how the residues from different species combinations in sole cropping or...  相似文献   
993.
Molecular Biology - Human translational methyltransferase (methylase) HEMK2, whose orthologues are found in many prokaryotes and eukaryotes, methylates such diverse substrates as glutamine and...  相似文献   
994.
Microbiology - The composition of microbial communities and the rates of microbial processes in the water column of a meromictic trough in the Biofilter Bay, Kandalaksha Bay, White Sea were...  相似文献   
995.
Microbiology - Polyethylene glycol (PEG 6000) was used to establish osmotic stress conditions during growth of the type strain Azospirillum brasilense Sp7 and its spontaneous variants Sp7.4 and...  相似文献   
996.
Molecular Biology - The endoplasmic reticulum (ER) stress inducers dithiothreitol (DTT) and sodium selenite (SS) were tested for effect on expression of ER selenoproteins and apoptosis markers in...  相似文献   
997.
Microbiology - The structure of the cell wall glycopolymer and the taxonomic position of the pyridine-degrading strain VKM Ac-1098D were established. By using chemical and NMR spectroscopic...  相似文献   
998.
Microbiology - Localization and structural organization of microbial biofilms developing in anthropogenic ecological niches of meat-processing plants using different raw materials (poultry, pork,...  相似文献   
999.
Microbiology - The strain of facultative chemolithotrophic bacteria isolated from soil within the aphotic zone of the Kinderlinskaya Cave (Southern Urals, Russia) was identified as member of the...  相似文献   
1000.
Plant Cell, Tissue and Organ Culture (PCTOC) - Leaf chlorosis is often a problem in micropropagated&nbsp;Rubus&nbsp;idaeus, which makes successful acclimatization difficult. We found that...  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