Browsing by Author "Wang, Q"

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    Teasaponin improves leptin sensitivity in the prefrontal cortex of obese mice
    (John Wiley and Sons, 2015-09-21) Yu, YH; Wu, YZ; Szabo, A; Wang, S; Yu, SJ; Wang, Q; Huang, XF
    Scope Obesity impairs cognition, and the leptin-induced increase of brain-derived neurotrophic factor (BDNF) and neurogenesis. Tea consumption improves cognition and increases brain activation in the prefrontal cortex. Methods and results This study examined whether teasaponin, an active ingredient in tea, could improve memory and central leptin effects on neurogenesis in the prefrontal cortex of obese mice, and in vitro in cultured prefrontal cortical neurons. Teasaponin (10 mg/kg, intraperitoneal) for 21 days improved downstream leptin signaling (JAK2 and STAT3), and leptin's effect on BDNF, in the prefrontal cortex of high-fat diet (HFD) fed mice. Prefrontal cortical neurons were cultured with teasaponin and palmitic acid (the most abundant dietary saturated fatty acid) to examine their effects on neurogenesis and BDNF expression in response to leptin. Palmitic acid decreased leptin's effect on neurite outgrowth, postsynaptic density protein 95, and BDNF expression in cultured cortical neurons, which was reversed by teasaponin. Conclusion Teasaponin improved the leptin sensitivity of prefrontal cortical neurons in obese mice or when treated by palmitic acid. This in turn increased BDNF expression and neurite growth. Therefore, teasaponin supplementation may be used to prevent obesity-associated neurodegeneration and improve cognitive function. © 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
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    Unlocking anionic redox activity in O3-type sodium 3d layered oxides via Li substitution
    (Springer Nature, 2021-01-11) lorem, Ipsum; Wang, Q; Mariyappan, S; Rousse, G; Morozov, AV; Porcheron, B; Dedryvère, R; Wu, JP; Yang, WL; Zhang, LT; Chakir, M; Avdeev, M; Deschamps, M; Yu, YS; Cabana, J; Doublet, ML; Abakumov, AM; Tarascon, JM
    Sodium ion batteries, because of their sustainability attributes, could be an attractive alternative to Li-ion technology for specific applications. However, it remains challenging to design high energy density and moisture stable Na-based positive electrodes. Here, we report an O3-type NaLi1/3Mn2/3O2 phase showing anionic redox activity, obtained through a ceramic process by carefully adjusting synthesis conditions and stoichiometry. This phase shows a sustained reversible capacity of 190 mAh g−1 that is rooted in cumulative oxygen and manganese redox processes as deduced by combined spectroscopy techniques. Unlike many other anionic redox layered oxides so far reported, O3-NaLi1/3Mn2/3O2 electrodes do not show discernible voltage fade on cycling. This finding, rationalized by density functional theory, sheds light on the role of inter- versus intralayer 3d cationic migration in ruling voltage fade in anionic redox electrodes. Another practical asset of this material stems from its moisture stability, hence facilitating its handling and electrode processing. Overall, this work offers future directions towards designing highly performing sodium electrodes for advanced Na-ion batteries. © 2021, The Author(s), under exclusive licence to Springer Nature Limited.