目的:观察己酮可可碱(PTX)对内毒素(LPS)诱导急性肺损伤(ALI)大鼠模型各项病理生理和生化指标的影响,探讨PTX对ALI的干预阻断作用.方法:将72只月龄和体质量相近的雄性SD大鼠随机分为3组:对照组(NS组),实验组(LPS组),治疗组(PTX组),每组2...目的:观察己酮可可碱(PTX)对内毒素(LPS)诱导急性肺损伤(ALI)大鼠模型各项病理生理和生化指标的影响,探讨PTX对ALI的干预阻断作用.方法:将72只月龄和体质量相近的雄性SD大鼠随机分为3组:对照组(NS组),实验组(LPS组),治疗组(PTX组),每组24只.给予对照组大鼠尾静脉注射生理盐水,实验组大鼠尾静脉内注射LPS4mg/kg,治疗组大鼠尾静脉注射LPS前1h,由腹腔注射0.036mol/LPTX10mg/kg.确认实验组复制ALI模型成功之后,即刻给予PTX10mg/kg腹腔注射,间隔1h重复给药,连续5次;其余两组大鼠与实验组同样时间间隔给予腹腔注射等容积的生理盐水.测定各组动脉血氧分压(PaO2),pH值,二氧化碳分压(PaCO2),肺系数,肺水含量,肺通透性指数,检测支气管肺泡灌洗液中性白细胞及巨噬细胞比例,检测丙二醛(MDA),超氧化物歧化酶(SOD),一氧化氮(NO),诱生性一氧化氮合成酶(iNOS)含量,并进行肺组织大体,病理形态学观察.结果:治疗组与实验组相比,PaO2和pH值升高,PaCO2降低,肺系数(0.59±0.17 vs 0.92±0.11,P<0.05),肺含水量(84.46±0.39 vs 80.22±0.37,P<0.05),肺通透性指数(7.28±0.54 vs 12.32±0.28,P<0.05)均有明显下降;肺泡灌洗液中性粒白细胞比例下降,肺通透指数减低,NO,iNOS明显下降,SOD水平显著升高(P<0.05).病理学观察治疗组肺组织病变较实验组为轻.结论:PTX对LPS诱导ALI大鼠模型具有保护作用,其机制可能与PTX改善能量代谢及减少局部细胞毒性物质有关.PTX对由LPS诱导的ALI具有一定保护作用.展开更多
Low‐temperature CO oxidation is important for both fundamental studies and practical applica‐tions. Supported gold catalysts are generally regarded as the most active catalysts for low‐temperature CO oxidation. The...Low‐temperature CO oxidation is important for both fundamental studies and practical applica‐tions. Supported gold catalysts are generally regarded as the most active catalysts for low‐temperature CO oxidation. The active sites are traditionally believed to be Au nanoclusters or nanoparticles in the size range of 0.5–5 nm. Only in the last few years have single‐atom Au catalysts been proved to be active for CO oxidation. Recent advances in both experimental and theoretical studies on single‐atom Au catalysts unambiguously demonstrated that when dispersed on suitable oxide supports the Au single atoms can be extremely active for CO oxidation. In this mini‐review, recent advances in the development of Au single‐atom catalysts are discussed, with the aim of illus‐trating their unique catalytic features during CO oxidation.展开更多
The structure and catalytic desulfurization characteristics of CeO2-TiO2 mixed oxides were investigated by means ofX-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and catalytic activity tests. Acco...The structure and catalytic desulfurization characteristics of CeO2-TiO2 mixed oxides were investigated by means ofX-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and catalytic activity tests. According to the results, a CeO2-TiO2solid solution is formed when the mole ratio of cerium to titanium n（Ce）：n（Ti） is 5：5 or greater, and the most suitable n（Ce）：n（Ti） isdetermined as 7：3, over which the conversion rate of SO2 and the yield of sulfur at 500℃ reach 93% and 99%, respectively.According to the activity testing curve, Ce0.7Ti0.3O2 （n（Ce）：n（Ti）=7：3） without any pretreatment can be gradually activated by reagentgas after about 10 min, and reaches a steady activation status 60 min later. The XPS results of Ce0.7Ti0.3O2 after different time ofSO2＋CO reaction show that CeO2 is the active component that offers the redox couple Ce4＋/Ce3＋ and the labile oxygen vacancies, andTiO2 only functions as a catalyst structure stabilizer during the catalytic reaction process. After 48 h of catalytic reaction at 500℃,Ce0.7Ti0.3O2 still maintains a stable structure without being vulcanized, demonstrating its good anti-sulfur poisoning performance.展开更多
CO oxidation is probably the most studied reaction in heterogeneous catalysis.This reaction has become a hot topic with the discovery of nanogold catalysts,which are active at low temperatures（at or below room temper...CO oxidation is probably the most studied reaction in heterogeneous catalysis.This reaction has become a hot topic with the discovery of nanogold catalysts,which are active at low temperatures（at or below room temperature）.Au catalysts are the benchmark for judging the activities of other metals in CO oxidation.Pt-group metals（PGMs） that give comparable performances are of particular interest.In this mini-review,we summarize the advances in various PGM（Pt,Pd,Ir,Rh,Ru）catalysts that have high catalytic activities in low-temperature CO oxidation arising from reducible supports or the presence of OH species.The effects of the size of the metal species and the importance of the interface between the metal and the reducible support are covered and discussed in terms of their promotional role in CO oxidation at low temperatures.展开更多
文摘目的:观察己酮可可碱(PTX)对内毒素(LPS)诱导急性肺损伤(ALI)大鼠模型各项病理生理和生化指标的影响,探讨PTX对ALI的干预阻断作用.方法:将72只月龄和体质量相近的雄性SD大鼠随机分为3组:对照组(NS组),实验组(LPS组),治疗组(PTX组),每组24只.给予对照组大鼠尾静脉注射生理盐水,实验组大鼠尾静脉内注射LPS4mg/kg,治疗组大鼠尾静脉注射LPS前1h,由腹腔注射0.036mol/LPTX10mg/kg.确认实验组复制ALI模型成功之后,即刻给予PTX10mg/kg腹腔注射,间隔1h重复给药,连续5次;其余两组大鼠与实验组同样时间间隔给予腹腔注射等容积的生理盐水.测定各组动脉血氧分压(PaO2),pH值,二氧化碳分压(PaCO2),肺系数,肺水含量,肺通透性指数,检测支气管肺泡灌洗液中性白细胞及巨噬细胞比例,检测丙二醛(MDA),超氧化物歧化酶(SOD),一氧化氮(NO),诱生性一氧化氮合成酶(iNOS)含量,并进行肺组织大体,病理形态学观察.结果:治疗组与实验组相比,PaO2和pH值升高,PaCO2降低,肺系数(0.59±0.17 vs 0.92±0.11,P<0.05),肺含水量(84.46±0.39 vs 80.22±0.37,P<0.05),肺通透性指数(7.28±0.54 vs 12.32±0.28,P<0.05)均有明显下降;肺泡灌洗液中性粒白细胞比例下降,肺通透指数减低,NO,iNOS明显下降,SOD水平显著升高(P<0.05).病理学观察治疗组肺组织病变较实验组为轻.结论:PTX对LPS诱导ALI大鼠模型具有保护作用,其机制可能与PTX改善能量代谢及减少局部细胞毒性物质有关.PTX对由LPS诱导的ALI具有一定保护作用.
文摘Low‐temperature CO oxidation is important for both fundamental studies and practical applica‐tions. Supported gold catalysts are generally regarded as the most active catalysts for low‐temperature CO oxidation. The active sites are traditionally believed to be Au nanoclusters or nanoparticles in the size range of 0.5–5 nm. Only in the last few years have single‐atom Au catalysts been proved to be active for CO oxidation. Recent advances in both experimental and theoretical studies on single‐atom Au catalysts unambiguously demonstrated that when dispersed on suitable oxide supports the Au single atoms can be extremely active for CO oxidation. In this mini‐review, recent advances in the development of Au single‐atom catalysts are discussed, with the aim of illus‐trating their unique catalytic features during CO oxidation.
文摘The structure and catalytic desulfurization characteristics of CeO2-TiO2 mixed oxides were investigated by means ofX-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and catalytic activity tests. According to the results, a CeO2-TiO2solid solution is formed when the mole ratio of cerium to titanium n（Ce）：n（Ti） is 5：5 or greater, and the most suitable n（Ce）：n（Ti） isdetermined as 7：3, over which the conversion rate of SO2 and the yield of sulfur at 500℃ reach 93% and 99%, respectively.According to the activity testing curve, Ce0.7Ti0.3O2 （n（Ce）：n（Ti）=7：3） without any pretreatment can be gradually activated by reagentgas after about 10 min, and reaches a steady activation status 60 min later. The XPS results of Ce0.7Ti0.3O2 after different time ofSO2＋CO reaction show that CeO2 is the active component that offers the redox couple Ce4＋/Ce3＋ and the labile oxygen vacancies, andTiO2 only functions as a catalyst structure stabilizer during the catalytic reaction process. After 48 h of catalytic reaction at 500℃,Ce0.7Ti0.3O2 still maintains a stable structure without being vulcanized, demonstrating its good anti-sulfur poisoning performance.
基金supported by the National Natural Science Foundation of China(21076211,21203181,21576251,21676269)the "Strategic Priority Research Program" of the Chinese Academy of Sciences(XDB17020100)+1 种基金the National Key projects for Fundamental Research and Development of China(2016YFA0202801)Department of Science and Technology of Liaoning Province under contract of 2015020086-101~~
文摘CO oxidation is probably the most studied reaction in heterogeneous catalysis.This reaction has become a hot topic with the discovery of nanogold catalysts,which are active at low temperatures（at or below room temperature）.Au catalysts are the benchmark for judging the activities of other metals in CO oxidation.Pt-group metals（PGMs） that give comparable performances are of particular interest.In this mini-review,we summarize the advances in various PGM（Pt,Pd,Ir,Rh,Ru）catalysts that have high catalytic activities in low-temperature CO oxidation arising from reducible supports or the presence of OH species.The effects of the size of the metal species and the importance of the interface between the metal and the reducible support are covered and discussed in terms of their promotional role in CO oxidation at low temperatures.
