The membrane-associated c-type cytochromes(c-Cyts) have been well known as the key enzymes mediating extracellular electron transfer to terminal electron acceptors, resulting in biogeochemical elemental transformation...The membrane-associated c-type cytochromes(c-Cyts) have been well known as the key enzymes mediating extracellular electron transfer to terminal electron acceptors, resulting in biogeochemical elemental transformation, contaminant degradation, and nutrient cycling. Although c-Cyts-mediated metal reduction or oxidation have been mainly investigated with the purified proteins of metal reducing/oxidizing bacteria, the in vivo behavior of c-Cyts is still unclear, given the difficulty in measuring the proteins of intact cells. Fortunately, the in situ spectroscopy would be ideal for measuring the reaction kinetics of c-Cyts in intact cells under noninvasive physiological conditions. It can also help the establishment of kinetic/thermodynamic models of extracellular electron transfer processes, which are essential to understand the electron transfer mechanisms at the molecular scale. This review briefly summarizes the current advances in spectral methods for examining the c-Cyts in intact cells of dissimilatory metal reducing bacteria and Fe(Ⅱ)-oxidizing bacteria.展开更多
The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibit...The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibited strong interaction with the fresh Mo2C/γ-Al2O3 catalyst and was adsorbed mainly on Moδ+ sites of fresh Mo2C/γ-Al2O3 catalyst. Moreover, CH3CN could affect the shifting of IR spectra for CO adsorption towards a lower wave number. The IR spectroscopic study on acetonitrile hydrogenation showed that CH3CN could be easily hydrogenated in the presence of H2 on the Mo2C/γ-Al2O3 catalyst. Furthermore, it was observed that CH3 CN could be selectively hydrogenated to imines on fresh Mo2C/γ-Al2O3 catalyst. Additionally, the active sites of fresh Mo2C/γ-Al2O3 catalyst might be covered with coke during the hydrogenation reaction of acetonitrile. The treatment of catalyst with hydrogen at 673 K could not completely remove coke deposits on the surface of the Mo2C/γ-Al2O3 catalyst.展开更多
We prepare oligothymonucleic acid (OTA) functionalized polyethylene (PE) film and evaluate its selective removal ability of mercury ions at ultra-low levels in aqueous solution. The selective binding of OTA with mercu...We prepare oligothymonucleic acid (OTA) functionalized polyethylene (PE) film and evaluate its selective removal ability of mercury ions at ultra-low levels in aqueous solution. The selective binding of OTA with mercury ions is confirmed by fluorescence in situ hybridization (FISH). The quantitative results via cold-vapor atomic fluorescence spectrometry (CVAFS) indicate that OTA-functionalized PE film is able to remove mercury ions at the sub-ppb level selectively from aqueous solution, even with the coexistence of other metal ions at concentrations 250-fold or higher than that of mercury.展开更多
基金funded by the National Natural Science Foundations of China(41522105 and 41571130052)Guangdong Natural Science Funds for Distinguished Young Scholar(2014A030306041)Special Support Program(2016)
文摘The membrane-associated c-type cytochromes(c-Cyts) have been well known as the key enzymes mediating extracellular electron transfer to terminal electron acceptors, resulting in biogeochemical elemental transformation, contaminant degradation, and nutrient cycling. Although c-Cyts-mediated metal reduction or oxidation have been mainly investigated with the purified proteins of metal reducing/oxidizing bacteria, the in vivo behavior of c-Cyts is still unclear, given the difficulty in measuring the proteins of intact cells. Fortunately, the in situ spectroscopy would be ideal for measuring the reaction kinetics of c-Cyts in intact cells under noninvasive physiological conditions. It can also help the establishment of kinetic/thermodynamic models of extracellular electron transfer processes, which are essential to understand the electron transfer mechanisms at the molecular scale. This review briefly summarizes the current advances in spectral methods for examining the c-Cyts in intact cells of dissimilatory metal reducing bacteria and Fe(Ⅱ)-oxidizing bacteria.
基金financially supported by the National Natural Science Foundation of China (No. 21573101)the Liaoning Provincial Natural Science Foundation (No. 2014020107)+1 种基金the Program for Liaoning Excellent Talents in Universities (No. LJQ2014041)sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (SRF for ROCS, SEM)
文摘The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibited strong interaction with the fresh Mo2C/γ-Al2O3 catalyst and was adsorbed mainly on Moδ+ sites of fresh Mo2C/γ-Al2O3 catalyst. Moreover, CH3CN could affect the shifting of IR spectra for CO adsorption towards a lower wave number. The IR spectroscopic study on acetonitrile hydrogenation showed that CH3CN could be easily hydrogenated in the presence of H2 on the Mo2C/γ-Al2O3 catalyst. Furthermore, it was observed that CH3 CN could be selectively hydrogenated to imines on fresh Mo2C/γ-Al2O3 catalyst. Additionally, the active sites of fresh Mo2C/γ-Al2O3 catalyst might be covered with coke during the hydrogenation reaction of acetonitrile. The treatment of catalyst with hydrogen at 673 K could not completely remove coke deposits on the surface of the Mo2C/γ-Al2O3 catalyst.
基金supported by National Natural Science Foundation of China(11175234, 11105210)the Knowledge Innovation Program of the Chinese Academy of Sciences (XDA02040300, KJCX2-YW-N49)Shanghai Municipal Commission for Science and Technology (10ZR1436700,11ZR1445400)
文摘We prepare oligothymonucleic acid (OTA) functionalized polyethylene (PE) film and evaluate its selective removal ability of mercury ions at ultra-low levels in aqueous solution. The selective binding of OTA with mercury ions is confirmed by fluorescence in situ hybridization (FISH). The quantitative results via cold-vapor atomic fluorescence spectrometry (CVAFS) indicate that OTA-functionalized PE film is able to remove mercury ions at the sub-ppb level selectively from aqueous solution, even with the coexistence of other metal ions at concentrations 250-fold or higher than that of mercury.
