目的分析产KPC-2肺炎克雷伯菌ST11株在南京大学附属鼓楼医院重症监护室(Intensive Care Unit,ICU)住院患者胃肠道的定植情况,并分析bla_(KPC-2)阳性肺炎克雷伯菌ST11菌株之间的遗传相关性。方法采集我院ICU患者的肛拭子,使用含有0.5μg...目的分析产KPC-2肺炎克雷伯菌ST11株在南京大学附属鼓楼医院重症监护室(Intensive Care Unit,ICU)住院患者胃肠道的定植情况,并分析bla_(KPC-2)阳性肺炎克雷伯菌ST11菌株之间的遗传相关性。方法采集我院ICU患者的肛拭子,使用含有0.5μg/mL美罗培南的麦康凯平板筛选碳青霉烯耐药肺炎克雷伯菌,K-B法测定其对临床常用抗菌药物的敏感性;采用PCR法和DNA测序技术检测bla_(KPC-2)基因;多位点序列分型技术分析bla_(KPC-2)基因阳性肺炎克雷伯菌的序列分型(sequence type,ST),筛选出ST11菌株。脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)技术分析产bla_(KPC-2)肺炎克雷伯菌ST11菌株之间的遗传相关性。结果共收集肛拭子125份,30株(24.2%)为碳青霉烯耐药肺炎克雷伯菌。其中,27株(90.0%)携带bla_(KPC-2)基因,26株(86.7%)细菌为肺炎克雷伯菌ST11,25株(83.3%)细菌为产KPC-2肺炎克雷伯菌ST11株。PFGE结果显示,19株产KPC-2肺炎克雷伯菌ST11菌株之间有很大的遗传相关性。结论产bla_(KPC-2)肺炎克雷伯菌ST11株在我院ICU患者胃肠道中定植广泛,可能是其感染的主要病原菌,需加强感染控制措施。展开更多
Supporting Pd catalysts characterized significant different size distribution were obtained using PdCl2,[Pd(NH3)4](NO3)2 and Pd(acac)2 as precursors.High-resolution transmission electron microscopy(TEM),X-ray diffract...Supporting Pd catalysts characterized significant different size distribution were obtained using PdCl2,[Pd(NH3)4](NO3)2 and Pd(acac)2 as precursors.High-resolution transmission electron microscopy(TEM),X-ray diffraction(XRD),in-situ Fourier transform infrared spectroscopy(FTIR)and Raman spectroscopy were used to examine the dispersion of Pd.Catalytic performance measurements show that the activities for CO oxidation increase as the Pd particle size decreases and the O2/CO ratio increases.The activities under oxygen rich conditions are significantly higher than those at near the stoichiometric conditions.Pd on TiO2 prepared by the Pd(acac)2 precursor is highly dispersed,leading to a considerable activity for CO oxidation at near room temperature.CO oxidation on the 1 wt%Pd/TiO2 and under an O2/CO ratio of 1 characterized an apparent activation energy of 36.7 kJ/mol,which is closed to those reported for CO oxidation on the supported Au catalysts.The present work demonstrates a high catalytic activity of highly dispersed noble metals,and suggests a promising approach of using noble metals as catalysts with exceeding high efficiency.展开更多
In situ time-resolved FTIR spectroscopy was used to study the reaction mechanism of partial oxidation of methane (POM) to synthesis gas and the reaction of CH4/O2/He (2/1/45, molar ratio) gas mixture with adsorbed CO ...In situ time-resolved FTIR spectroscopy was used to study the reaction mechanism of partial oxidation of methane (POM) to synthesis gas and the reaction of CH4/O2/He (2/1/45, molar ratio) gas mixture with adsorbed CO species over Rh/SiO2, Ru/γ-Al2O3 and Ru/SiO2 catalysts at 500-600℃. It was found that CO is the primary product of POM reaction over reduced and working state Rh/SiO2 catalysts. Direct oxidation of CH4 is the main pathway of synthesis gas formation over Rh/SiO2 catalyst. CO2 is the primary product of POM over Ru/γ-Al2O3 and Ru/SiO2 catalysts. The dominant reaction pathway for synthesis gas formation over Ru/γ-Al2O3 catalyst is via the reforming reactions of CH4 with CO2 and H2O. For the POM reaction over Rh/SiO2 and Ru/γ-Al2O3 catalysts, consecutive oxidation of surface CO species is an important pathway of CO2 formation.展开更多
文摘目的分析产KPC-2肺炎克雷伯菌ST11株在南京大学附属鼓楼医院重症监护室(Intensive Care Unit,ICU)住院患者胃肠道的定植情况,并分析bla_(KPC-2)阳性肺炎克雷伯菌ST11菌株之间的遗传相关性。方法采集我院ICU患者的肛拭子,使用含有0.5μg/mL美罗培南的麦康凯平板筛选碳青霉烯耐药肺炎克雷伯菌,K-B法测定其对临床常用抗菌药物的敏感性;采用PCR法和DNA测序技术检测bla_(KPC-2)基因;多位点序列分型技术分析bla_(KPC-2)基因阳性肺炎克雷伯菌的序列分型(sequence type,ST),筛选出ST11菌株。脉冲场凝胶电泳(pulsed field gel electrophoresis,PFGE)技术分析产bla_(KPC-2)肺炎克雷伯菌ST11菌株之间的遗传相关性。结果共收集肛拭子125份,30株(24.2%)为碳青霉烯耐药肺炎克雷伯菌。其中,27株(90.0%)携带bla_(KPC-2)基因,26株(86.7%)细菌为肺炎克雷伯菌ST11,25株(83.3%)细菌为产KPC-2肺炎克雷伯菌ST11株。PFGE结果显示,19株产KPC-2肺炎克雷伯菌ST11菌株之间有很大的遗传相关性。结论产bla_(KPC-2)肺炎克雷伯菌ST11株在我院ICU患者胃肠道中定植广泛,可能是其感染的主要病原菌,需加强感染控制措施。
基金supported by the National Natural Science Foundation of China(20873109)National Basic Research Program of China(973 program)(2005CB221401,2010CB732303)+2 种基金Major Project of Chinese Minis-try of Education(309019)the PhD Programs Foundation of Chinese Ministry of Education(200803841011)Natural Science Foundation of Fujian Province,China(2008J0168)
文摘Supporting Pd catalysts characterized significant different size distribution were obtained using PdCl2,[Pd(NH3)4](NO3)2 and Pd(acac)2 as precursors.High-resolution transmission electron microscopy(TEM),X-ray diffraction(XRD),in-situ Fourier transform infrared spectroscopy(FTIR)and Raman spectroscopy were used to examine the dispersion of Pd.Catalytic performance measurements show that the activities for CO oxidation increase as the Pd particle size decreases and the O2/CO ratio increases.The activities under oxygen rich conditions are significantly higher than those at near the stoichiometric conditions.Pd on TiO2 prepared by the Pd(acac)2 precursor is highly dispersed,leading to a considerable activity for CO oxidation at near room temperature.CO oxidation on the 1 wt%Pd/TiO2 and under an O2/CO ratio of 1 characterized an apparent activation energy of 36.7 kJ/mol,which is closed to those reported for CO oxidation on the supported Au catalysts.The present work demonstrates a high catalytic activity of highly dispersed noble metals,and suggests a promising approach of using noble metals as catalysts with exceeding high efficiency.
文摘In situ time-resolved FTIR spectroscopy was used to study the reaction mechanism of partial oxidation of methane (POM) to synthesis gas and the reaction of CH4/O2/He (2/1/45, molar ratio) gas mixture with adsorbed CO species over Rh/SiO2, Ru/γ-Al2O3 and Ru/SiO2 catalysts at 500-600℃. It was found that CO is the primary product of POM reaction over reduced and working state Rh/SiO2 catalysts. Direct oxidation of CH4 is the main pathway of synthesis gas formation over Rh/SiO2 catalyst. CO2 is the primary product of POM over Ru/γ-Al2O3 and Ru/SiO2 catalysts. The dominant reaction pathway for synthesis gas formation over Ru/γ-Al2O3 catalyst is via the reforming reactions of CH4 with CO2 and H2O. For the POM reaction over Rh/SiO2 and Ru/γ-Al2O3 catalysts, consecutive oxidation of surface CO species is an important pathway of CO2 formation.
