Nanosized fibrous cerium（IV） hydrogen phosphate membrane, Ce（HPO4）2·2.9H20 （nCePf）, was prepared and characterized by chemical, XRD （X-ray diffraction）, TGA （thermogravimetric analysis）, SEM （scanning ...Nanosized fibrous cerium（IV） hydrogen phosphate membrane, Ce（HPO4）2·2.9H20 （nCePf）, was prepared and characterized by chemical, XRD （X-ray diffraction）, TGA （thermogravimetric analysis）, SEM （scanning electron microscopy） and TEM （transmission electron microscopy）. Novel supported nanofibrous Ce（IV） phosphate/polyiondole nanocomposite membranes were prepared via in-situ chemical oxidation of the monomer that was promoted by the reduction of Ce（IV） ions present in the inorganic matrix. The presence of Ce（IV） ions allows redox reactions necessary to oxidative polymerization to occur. The resultant material was characterized by TGA, elemental （C, H, N） analysis and FT-IR （Fourier transform spectroscopy）. SEM images of the resulting nanocomposite reveals a uniform distribution of the polymer on the inorganic matrix. Amount of polyindole polymer present in the composite is found to be - 7.0%.展开更多
The activity of plasma membrane （PM） nicotinamide adenine dinucleotide phosphate （NADPH） oxidase and its catalytic properties in rice was investigated under drought stress conditions. Drought stress led to decreas...The activity of plasma membrane （PM） nicotinamide adenine dinucleotide phosphate （NADPH） oxidase and its catalytic properties in rice was investigated under drought stress conditions. Drought stress led to decreased leaf relative water content （RWC） and, as a result of drought-induced oxidative stress, the activities of antioxidant enzymes increased significantly. More interestingly, the intensity of applied water stress was correlated with increased production of H2O2 and O2^- and elevated activity of PM NADPH oxidase, a key enzyme of reactive oxygen species generation in plants. Histochemical analyses also revealed increased H2O2 and O2^- production in drought-stressed leaves. Application of diphenylene iodonium （DPI）, an inhibitor of PM NADPH oxidase, did not alleviate drought-induced production of H2O2 and O2^-. Catalysis experiments indicated that the rice PM NADPH oxidase was partially fiavin-dependent. The pH and temperature optima for this enzyme were 9.8 and 40 ℃, respectively. In addition, drought stress enhanced the activity under alkaline pH and high temperature conditions. These results suggest that a complex regulatory mechanism, associated with the NADPH oxidase-H2O2 system, is involved in the response of rice to drought stress.展开更多
文摘Nanosized fibrous cerium（IV） hydrogen phosphate membrane, Ce（HPO4）2·2.9H20 （nCePf）, was prepared and characterized by chemical, XRD （X-ray diffraction）, TGA （thermogravimetric analysis）, SEM （scanning electron microscopy） and TEM （transmission electron microscopy）. Novel supported nanofibrous Ce（IV） phosphate/polyiondole nanocomposite membranes were prepared via in-situ chemical oxidation of the monomer that was promoted by the reduction of Ce（IV） ions present in the inorganic matrix. The presence of Ce（IV） ions allows redox reactions necessary to oxidative polymerization to occur. The resultant material was characterized by TGA, elemental （C, H, N） analysis and FT-IR （Fourier transform spectroscopy）. SEM images of the resulting nanocomposite reveals a uniform distribution of the polymer on the inorganic matrix. Amount of polyindole polymer present in the composite is found to be - 7.0%.
基金Supported by the National Natural Science Foundation of China under GrantNo. 30871469the Zhejiang Province Natural Science Foundation of China under Grant No. Y306087
文摘The activity of plasma membrane （PM） nicotinamide adenine dinucleotide phosphate （NADPH） oxidase and its catalytic properties in rice was investigated under drought stress conditions. Drought stress led to decreased leaf relative water content （RWC） and, as a result of drought-induced oxidative stress, the activities of antioxidant enzymes increased significantly. More interestingly, the intensity of applied water stress was correlated with increased production of H2O2 and O2^- and elevated activity of PM NADPH oxidase, a key enzyme of reactive oxygen species generation in plants. Histochemical analyses also revealed increased H2O2 and O2^- production in drought-stressed leaves. Application of diphenylene iodonium （DPI）, an inhibitor of PM NADPH oxidase, did not alleviate drought-induced production of H2O2 and O2^-. Catalysis experiments indicated that the rice PM NADPH oxidase was partially fiavin-dependent. The pH and temperature optima for this enzyme were 9.8 and 40 ℃, respectively. In addition, drought stress enhanced the activity under alkaline pH and high temperature conditions. These results suggest that a complex regulatory mechanism, associated with the NADPH oxidase-H2O2 system, is involved in the response of rice to drought stress.
