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   1520篇
  免费   145篇
  国内免费   2篇
  2023年   8篇
  2022年   8篇
  2021年   31篇
  2020年   14篇
  2019年   17篇
  2018年   24篇
  2017年   21篇
  2016年   36篇
  2015年   62篇
  2014年   72篇
  2013年   92篇
  2012年   115篇
  2011年   103篇
  2010年   65篇
  2009年   71篇
  2008年   103篇
  2007年   99篇
  2006年   81篇
  2005年   87篇
  2004年   70篇
  2003年   75篇
  2002年   84篇
  2001年   15篇
  2000年   10篇
  1999年   14篇
  1998年   17篇
  1997年   17篇
  1996年   8篇
  1995年   9篇
  1994年   6篇
  1993年   11篇
  1992年   8篇
  1991年   7篇
  1990年   7篇
  1989年   6篇
  1988年   9篇
  1987年   7篇
  1986年   5篇
  1985年   9篇
  1984年   16篇
  1983年   7篇
  1982年   10篇
  1981年   7篇
  1980年   5篇
  1978年   5篇
  1974年   6篇
  1973年   5篇
  1966年   4篇
  1908年   5篇
  1889年   4篇
排序方式: 共有1667条查询结果,搜索用时 46 毫秒
981.
The carbohydrate chains of the respiratory-mucus glycoproteins of a patient suffering from bronchiectasis due to Kartagener's syndrome were released by alkaline borohydride treatment. Low-molecular-mass, monosialyl oligosaccharide-alditols were isolated by anion-exchange chromatography and fractionated by consecutive straight-phase high-performance liquid chromatography (HPLC) on a silica-based alkylamine column, and reverse-phase HPLC on a silica-based octadecyl column, respectively. The structures of the oligosaccharidealditols were determined by 500-MHz 1H-NMR spectroscopy in combination with sugar composition analysis. The 24 structures established range in size from disaccharides to heptasaccharides. Novel oligosaccharides obtained from the bronchiectasis mucus glycoproteins are: (formula; see text) 23 of the 24 monosialyl oligosaccharides characterized can be conceived of as extensions of neutral oligosaccharides purified from the bronchial mucus of this patient [Klein, A. et al. (1988) Eur. J. Biochem. 171, 631-642; Breg, J. et al. (1988) Eur. J Biochem. 171, 643-654]. The sialic acid residue was found to occur either in alpha (2----3)- or alpha (2----6)-linkage to a galactosyl residue or in alpha (2----6)-linkage to GalNAc-ol.  相似文献   
982.
983.
984.
985.
986.
We investigated whether partitioning DLCO into membrane conductance for CO (DmCO) and pulmonary capillary blood volume (Vcap) was helpful in suspecting precapillary pulmonary (arterial) hypertension (P(A)H) in systemic sclerosis (SSc) patients with or without interstitial lung disease (ILD). We included 63 SSc patients with isolated PAH (n=6), isolated ILD (n=19), association of both (n=12) or without PAH and ILD (n=26). Partitioning of DLCO was performed by the combined DLNO/DLCO method. DLCO, DmCO and Vcap were equally reduced in patients with isolated PAH and patients with isolated ILD but Vcap/alveolar volume (VA) ratio was significantly lower in the isolated PAH group. In patients without ILD, DLCO, DmCO, Vcap and Vcap/VA ratio were reduced in patients with isolated PAH when compared to patients without PAH and both Vcap/VA and DLCO had the highest AUC to detect PAH. In patients with ILD, Vcap had the highest AUC and performed better than DLCO to detect PH in this subgroup. In conclusion, Vcap/VA was lower in PAH than in ILD in SSC whereas DLCO was not different. Vcap/VA ratio and DLCO had similar high performance to detect PAH in patients without ILD. Vcap had better AUC than DLCO, DmCO and FVC/DLCO ratio to detect PH in SSC patients with ILD. These results suggest that partitioning of DLCO might be of interest to detect P(A)H in SSC patients with or without ILD.  相似文献   
987.
988.
989.
990.
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