Designing and/or searching for novel antioxidants against oxygen glucose effective strategy for the treatment of human isdlemic stroke. Selenium is deprivation （OGD）-induced oxidative damage represents an an essenti...Designing and/or searching for novel antioxidants against oxygen glucose effective strategy for the treatment of human isdlemic stroke. Selenium is deprivation （OGD）-induced oxidative damage represents an an essential trace dement, which is beneficial in the chemo- prevention and chemotherapy of cerebral ischemic stroke. The underlying mechanisms for its therapeutic effects, however, are not well documented. Selenocysteine （SeC） is a selenium-containing amino acid with neuroprotective potential. Studies have shown that SeC can reduce irradiation-induced DNA apoptosis by reducing DNA damage. In this study, the in vitro protective potential and mechanism of action of SeC against OGD-induced apoptosis and neurotoxicity were evaluated in HT22 mouse hippocampal neurons. We cultured HT22 cells in a glucose-free medium containing 2 mM Na2S402, which formed an OGD environment, for 90 minutes. Findings from MTT, flow cytometry and TUNEL staining showed obvious cytotoxicity and apoptosis in HT22 cells in the OGD condition. The activation of Caspa se-7 and Caspase-9 further revealed that OGD-induced apoptosis of HT22 cells was mainly achieved by triggering a mitochondrial-medi- ated pathway. Moreover, the OGD condition also induced serious DNA damage through the accumulation of reactive oxygen species and superoxide anions. However, SeC pre-treatment for 6 hours effectively inhibited OGD-induced cytotoxicity and apoptosis in HT22 cells by inhibiting reactive oxygen species-mediated oxidative damage. Our findings provide evidence that SeC has the potential to suppress OGD-induced oxidative damage and apoptosis in hippocampal neurons.展开更多
The catalytic behavior of ultra-low-gold-loaded Au/CeO2 during CO oxidation was studied using HRTEM, TGA, in-situ FTIR, CO--TPD, O2-TPD, and O2-TPO. Herein, water, which facilitates CO oxidation, is present on the cat...The catalytic behavior of ultra-low-gold-loaded Au/CeO2 during CO oxidation was studied using HRTEM, TGA, in-situ FTIR, CO--TPD, O2-TPD, and O2-TPO. Herein, water, which facilitates CO oxidation, is present on the catalyst rather than obtained from the reactant gas. The experimental results show that the presence of water on the catalyst enhances the adsorption and activation of 02 to produce Oact on the catalyst surface, resulting in excellent catalytic activity. Different reaction pathways for CO oxidation over Au/CeO2 may be present; however, the dominant pathway is influenced by the species on the catalyst surface.展开更多
基金supported by the Sci-Tech Development Project of Taian in Shandong,No.2016NS1058&2015NS2081the Sci-Tech Development Project of Linyi in Shandong,No.201515006
文摘Designing and/or searching for novel antioxidants against oxygen glucose effective strategy for the treatment of human isdlemic stroke. Selenium is deprivation （OGD）-induced oxidative damage represents an an essential trace dement, which is beneficial in the chemo- prevention and chemotherapy of cerebral ischemic stroke. The underlying mechanisms for its therapeutic effects, however, are not well documented. Selenocysteine （SeC） is a selenium-containing amino acid with neuroprotective potential. Studies have shown that SeC can reduce irradiation-induced DNA apoptosis by reducing DNA damage. In this study, the in vitro protective potential and mechanism of action of SeC against OGD-induced apoptosis and neurotoxicity were evaluated in HT22 mouse hippocampal neurons. We cultured HT22 cells in a glucose-free medium containing 2 mM Na2S402, which formed an OGD environment, for 90 minutes. Findings from MTT, flow cytometry and TUNEL staining showed obvious cytotoxicity and apoptosis in HT22 cells in the OGD condition. The activation of Caspa se-7 and Caspase-9 further revealed that OGD-induced apoptosis of HT22 cells was mainly achieved by triggering a mitochondrial-medi- ated pathway. Moreover, the OGD condition also induced serious DNA damage through the accumulation of reactive oxygen species and superoxide anions. However, SeC pre-treatment for 6 hours effectively inhibited OGD-induced cytotoxicity and apoptosis in HT22 cells by inhibiting reactive oxygen species-mediated oxidative damage. Our findings provide evidence that SeC has the potential to suppress OGD-induced oxidative damage and apoptosis in hippocampal neurons.
文摘The catalytic behavior of ultra-low-gold-loaded Au/CeO2 during CO oxidation was studied using HRTEM, TGA, in-situ FTIR, CO--TPD, O2-TPD, and O2-TPO. Herein, water, which facilitates CO oxidation, is present on the catalyst rather than obtained from the reactant gas. The experimental results show that the presence of water on the catalyst enhances the adsorption and activation of 02 to produce Oact on the catalyst surface, resulting in excellent catalytic activity. Different reaction pathways for CO oxidation over Au/CeO2 may be present; however, the dominant pathway is influenced by the species on the catalyst surface.
