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Xiaolu Jiang 《Tetrahedron》2010,66(52):9828-9834
Gold(I) and (III) salts have been found to be highly effective at the catalysis of ether formation from alcohols. Intramolecular ether formation of a 1,5-diol was also achieved, with a stereoselectivity that indicates that an SN1 mechanism predominates. In an attempt to form a seven-membered ring, a stable 14-membered dimer product was also formed. Attempts to control the diastereoselectivity of the reaction using a chiral anionic counterion did not give products with a high de. 相似文献
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Shu‐Ping Wang Lei Liu Ling‐Ling Wang Peng Jiang Ji‐Quan Zhang Wei‐Dong Zhang Run‐Hui Liu 《Rapid communications in mass spectrometry : RCM》2010,24(11):1641-1652
Based on the serum pharmacochemistry technique and high‐performance liquid chromatography/diode‐array detection (HPLC/DAD) coupled with electrospray tandem mass spectrometry (HPLC/ESI‐MS/MS), a method for screening and analysis of the multiple absorbed bioactive components and metabolites of Jitai tablets (JTT) in orally dosed rat plasma was developed. Plasma was treated by methanol precipitation prior to liquid chromatography, and the separation was carried out on a Symmetry C18 column, with a linear gradient (0.1% formic acid/water/acetonitrile). Mass spectra were acquired in negative and positive ion modes, respectively. As a result, 26 bioactive components originated from JTT and 5 metabolites were tentatively identified in orally dosed rat plasma by comparing their retention times and MS spectra with those of authentic standards and literature data. It is concluded that an effective and reliable analytical method was set up for screening the bioactive components of Chinese herbal medicine, which provided a meaningful basis for further pharmacology and active mechanism research of JTT. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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L.Z. Cao H. Jiang H. Song X. Liu W.G. Guo S.Z. Yu Z.M. Li G.Q. Miao 《Solid State Communications》2010,150(15-16):794-798
Three different shapes of SiC/SiO2 core–shell nanowires were synthesized on Si substrates through a reaction between methane and silica using iron as catalyst. Analysis of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results indicated that catalyst morphology was the key factor for the formation of these three different products. The field emission properties of these three nanowires were investigated. Comparing the field emission results of these three nanowires, we can obtain a conclusion that a vertically well-aligned orientation to the substrate played a very significant role in improving the field emission properties when the emitters are up to a considerable number. 相似文献
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S. Chen X. S. Jiang J. X. Chen X. Q. Zhu L. Q. Zheng S. M. Zhuo H. Q. Yang D. J. Wang 《Laser Physics》2010,20(4):900-903
We use a novel nonlinear optical technique, multiphoton microscopy, to differentiate keloids from hypertrophic and normal scars through the morphological and quantitative analysis of collagen and elastin in superficial dermis of scar tissues and boundary between normal skin and scar tissue. 相似文献