Ni/Mg/Al layered double hydroxides(LDHs) with different n(Ni)∶n(Mg)∶n(Al) ratio values were prepared via a coprecipitation reaction. Then Ni/Mg/Al mixed oxides were obtained by calcination of these LDHs precursors. ...Ni/Mg/Al layered double hydroxides(LDHs) with different n(Ni)∶n(Mg)∶n(Al) ratio values were prepared via a coprecipitation reaction. Then Ni/Mg/Al mixed oxides were obtained by calcination of these LDHs precursors. Carbon nanotubes were produced in the catalytic decomposition of propane over the Ni/Mg/Al mixed oxide catalysts. The quality of as-made nanotubes was investigated by SEM and TEM. The nanotubes were multiwall with a high length-diameter ratio and appeared to be flexible. The catalytic activities of these mixed oxides increased with increasing the Ni content. The Ni/Mg/Al mixed oxide with the highest Ni content [n(Ni)/n(Mg)/n(Al)=1/1/1] showed the highest activity and the carbon nanotubes grown on its surface had the best quality.展开更多
目的检测肠易激综合征大鼠肠道菌群及体内氨基酸的变化,探索应激致肠易激综合征的发生机制。方法采用母婴分离应激的方法建立肠易激综合征动物模型,收集大鼠的粪便和血清。采用高通量测序技术对粪便样本中所有细菌16S r DNA的V3、V4和V...目的检测肠易激综合征大鼠肠道菌群及体内氨基酸的变化,探索应激致肠易激综合征的发生机制。方法采用母婴分离应激的方法建立肠易激综合征动物模型,收集大鼠的粪便和血清。采用高通量测序技术对粪便样本中所有细菌16S r DNA的V3、V4和V6区进行测序,并进行菌群的生物信息学分析。采用全自动氨基酸分析仪检测分析大鼠粪便和血清样本的20种常见氨基酸含量。结果与正常大鼠相比,肠易激综合征大鼠肠道菌群的Shannon指数下降,表明菌群多样性有所下降。肠易激综合征大鼠的毛螺菌科、克里斯滕森菌科、单形拟杆菌、δ变形菌纲以及脱硫弧菌目、脱硫弧菌科和脱硫弧菌属的相对丰度均显著升高。同时,肠易激综合征大鼠粪便中的苏氨酸、丝氨酸、蛋氨酸、赖氨酸和脯氨酸浓度显著增高,血清中蛋氨酸、脯氨酸和苯丙氨酸浓度显著升高,甘氨酸和赖氨酸浓度则显著下降。结论应激引起肠道菌群失调以及氨基酸代谢异常,该变化可能与慢性应激导致的肠易激综合征有关。展开更多
文摘Ni/Mg/Al layered double hydroxides(LDHs) with different n(Ni)∶n(Mg)∶n(Al) ratio values were prepared via a coprecipitation reaction. Then Ni/Mg/Al mixed oxides were obtained by calcination of these LDHs precursors. Carbon nanotubes were produced in the catalytic decomposition of propane over the Ni/Mg/Al mixed oxide catalysts. The quality of as-made nanotubes was investigated by SEM and TEM. The nanotubes were multiwall with a high length-diameter ratio and appeared to be flexible. The catalytic activities of these mixed oxides increased with increasing the Ni content. The Ni/Mg/Al mixed oxide with the highest Ni content [n(Ni)/n(Mg)/n(Al)=1/1/1] showed the highest activity and the carbon nanotubes grown on its surface had the best quality.
文摘目的检测肠易激综合征大鼠肠道菌群及体内氨基酸的变化,探索应激致肠易激综合征的发生机制。方法采用母婴分离应激的方法建立肠易激综合征动物模型,收集大鼠的粪便和血清。采用高通量测序技术对粪便样本中所有细菌16S r DNA的V3、V4和V6区进行测序,并进行菌群的生物信息学分析。采用全自动氨基酸分析仪检测分析大鼠粪便和血清样本的20种常见氨基酸含量。结果与正常大鼠相比,肠易激综合征大鼠肠道菌群的Shannon指数下降,表明菌群多样性有所下降。肠易激综合征大鼠的毛螺菌科、克里斯滕森菌科、单形拟杆菌、δ变形菌纲以及脱硫弧菌目、脱硫弧菌科和脱硫弧菌属的相对丰度均显著升高。同时,肠易激综合征大鼠粪便中的苏氨酸、丝氨酸、蛋氨酸、赖氨酸和脯氨酸浓度显著增高,血清中蛋氨酸、脯氨酸和苯丙氨酸浓度显著升高,甘氨酸和赖氨酸浓度则显著下降。结论应激引起肠道菌群失调以及氨基酸代谢异常,该变化可能与慢性应激导致的肠易激综合征有关。
