The ameliorative effect of external Ca^2＋ on Jerusalem artichoke （Helianthus tuberosus L.） under salt stress was studied through biochemical and physiological analyses of Jerusalem artichoke seedlings treated with ...The ameliorative effect of external Ca^2＋ on Jerusalem artichoke （Helianthus tuberosus L.） under salt stress was studied through biochemical and physiological analyses of Jerusalem artichoke seedlings treated with or without 10 mol L^-1 CaCl2, 150 mmol L^-1 NaCl, and/or 5 mmol L^-1 ethylene-bis（oxyethylenenitrilo）-tetraacetic acid （EGTA） for five days. Exposure to NaC1 （150 mmol L^-1） decreased growth, leaf chlorophyll content, and photosynthetic rate of Jerusalem artichoke seedlings. NaC1 treatment showed 59% and 37% higher lipid peroxidation and electrolyte leakage, respectively, than the control. The activities of superoxide dismutase （SOD）, peroxidase （POD）, and catalase （CAT） were decreased by NaCl, indicating an impeded antioxidant defense mechanism of Jerusalem artichoke grown under salt stress. Addition of 10 mmol L^-1 CaCl2 to the salt solutions significantly decreased the damaging effect of NaC1 on growth and chlorophyll content and simultaneously restored the rate of photosynthesis almost to the level of the control. Ca^2＋ addition decreased the leaf malondialdehyde （MDA） content and electrolyte leakage from NaCl-treated seedlings by 47% and 24%, respectively, and significantly improved the activities of SOD, POD, and CAT in NaCl-treated plants. Addition of EGTA, a specific chelator of Ca2＋, decreased the growth, chlorophyll content, and photosynthesis, and increased level of MDA and electrolyte leakage from NaCl-treated plants and from the control plants. EGTA addition to the growth medium also repressed the activities of SOD, POD, and CAT in NaCl-treated and control seedlings. External Ca2＋ might protect Jerusalem artichoke against NaC1 stress by up-regulating the activities of antioxidant enzymes and thereby decreasing the oxidative stress.展开更多
Isothermal and cyclic oxidation behaviors of pure and yttrium-implanted nickel were studied at 1 000℃ in air. The oxide scales formed on nickel substrates were performed using SEM and TEM. It was found that Y-implant...Isothermal and cyclic oxidation behaviors of pure and yttrium-implanted nickel were studied at 1 000℃ in air. The oxide scales formed on nickel substrates were performed using SEM and TEM. It was found that Y-implantation greatly improved the anti-oxidation ability of nickel both in isothermal and cyclic oxidizing experiments. Laser Raman microscopy was also used to study the stress status of oxide scales formed on nickel with and without yttrium. The main reason for the improvement in anti-oxidation and adhesion of oxide scale was Y-implantation greatly reduced the grain size of NiO and lowered the compressive stress within the scale. Yttrium implantation enhanced the adhesion of protective NiO oxide scale formed on nickel substrate.展开更多
Oxidative stress therapy targeted on ox plays idativ critical role in the pathogenesis of chronic obstructive e stress is of great importance for COPD. However, since pu the lmonary disease （COPD）, so current used a...Oxidative stress therapy targeted on ox plays idativ critical role in the pathogenesis of chronic obstructive e stress is of great importance for COPD. However, since pu the lmonary disease （COPD）, so current used antioxidants are not satisfying, scientists have to find more effective antioxidants for COPD. Hydrogen, the most abundant chemical element in the universe, was recently discovered as a novel therapeutic medical gas, and has shown great antioxidant potential in a series of recent published researches for its feature of selectively reducing toxic reactive oxygen species. Based on these findings, we hypothesize that hydrogen gas therapy might be a novel, effective, safe, and economic treatment for COPD patients in one day展开更多
基金the National High Technology Research and Development Program of China (863 Program)(No. 2003AA627040).
文摘The ameliorative effect of external Ca^2＋ on Jerusalem artichoke （Helianthus tuberosus L.） under salt stress was studied through biochemical and physiological analyses of Jerusalem artichoke seedlings treated with or without 10 mol L^-1 CaCl2, 150 mmol L^-1 NaCl, and/or 5 mmol L^-1 ethylene-bis（oxyethylenenitrilo）-tetraacetic acid （EGTA） for five days. Exposure to NaC1 （150 mmol L^-1） decreased growth, leaf chlorophyll content, and photosynthetic rate of Jerusalem artichoke seedlings. NaC1 treatment showed 59% and 37% higher lipid peroxidation and electrolyte leakage, respectively, than the control. The activities of superoxide dismutase （SOD）, peroxidase （POD）, and catalase （CAT） were decreased by NaCl, indicating an impeded antioxidant defense mechanism of Jerusalem artichoke grown under salt stress. Addition of 10 mmol L^-1 CaCl2 to the salt solutions significantly decreased the damaging effect of NaC1 on growth and chlorophyll content and simultaneously restored the rate of photosynthesis almost to the level of the control. Ca^2＋ addition decreased the leaf malondialdehyde （MDA） content and electrolyte leakage from NaCl-treated seedlings by 47% and 24%, respectively, and significantly improved the activities of SOD, POD, and CAT in NaCl-treated plants. Addition of EGTA, a specific chelator of Ca2＋, decreased the growth, chlorophyll content, and photosynthesis, and increased level of MDA and electrolyte leakage from NaCl-treated plants and from the control plants. EGTA addition to the growth medium also repressed the activities of SOD, POD, and CAT in NaCl-treated and control seedlings. External Ca2＋ might protect Jerusalem artichoke against NaC1 stress by up-regulating the activities of antioxidant enzymes and thereby decreasing the oxidative stress.
文摘Isothermal and cyclic oxidation behaviors of pure and yttrium-implanted nickel were studied at 1 000℃ in air. The oxide scales formed on nickel substrates were performed using SEM and TEM. It was found that Y-implantation greatly improved the anti-oxidation ability of nickel both in isothermal and cyclic oxidizing experiments. Laser Raman microscopy was also used to study the stress status of oxide scales formed on nickel with and without yttrium. The main reason for the improvement in anti-oxidation and adhesion of oxide scale was Y-implantation greatly reduced the grain size of NiO and lowered the compressive stress within the scale. Yttrium implantation enhanced the adhesion of protective NiO oxide scale formed on nickel substrate.
文摘Oxidative stress therapy targeted on ox plays idativ critical role in the pathogenesis of chronic obstructive e stress is of great importance for COPD. However, since pu the lmonary disease （COPD）, so current used antioxidants are not satisfying, scientists have to find more effective antioxidants for COPD. Hydrogen, the most abundant chemical element in the universe, was recently discovered as a novel therapeutic medical gas, and has shown great antioxidant potential in a series of recent published researches for its feature of selectively reducing toxic reactive oxygen species. Based on these findings, we hypothesize that hydrogen gas therapy might be a novel, effective, safe, and economic treatment for COPD patients in one day
