No abstract

No abstract

No abstract

No abstract

Sodium‐ion batteries (SIBs), which are an alternative to lithium‐ion batteries (LIBs), have attracted increasing attention due to their low cost of Na resources and similar Na storage mechanism to LIBs. Compared with anode materials and electrolytes, the development of cathode materials lags behind. Therefore, the key to improving the specific energy and promoting the application of SIBs is to develop high‐performance sodium intercalation cathode materials. Transition‐metal oxides are one of the most promising cathode materials for SIBs owing to their excellent energy density, high specific discharge capacity, and environmentally friendly nature. In the present work, the latest progress in the research of transition‐metal oxides is summarized. Moreover, the existing challenges are discussed, and a series of strategies are proposed to overcome these drawbacks. This review aims at providing guidance for the development of metal oxides in the next stage.

Sirtuin3 (SIRT3) is an important member of the sirtuin family of protein deacetylases that is localized to mitochondria and linked to lifespan extension in organisms ranging from yeast to humans. As aged cells have less regenerative capacity and are more susceptible to oxidative stress, we investigated the effect of ageing on SIRT3 levels and its correlation with antioxidant enzyme activities. Here, we show that severe oxidative stress reduces SIRT3 levels in young human mesenchymal stromal/stem cells (hMSCs). Overexpression of SIRT3 improved hMSCs resistance to the detrimental effects of oxidative stress. By activating manganese superoxide dismutase (MnSOD) and catalase (CAT), SIRT3 protects hMSCs from apoptosis under stress. SIRT3 expression, levels of MnSOD and CAT, as well as cell survival showed little difference in old versus young hMSCs under normal growth conditions, whereas older cells had a significantly reduced capacity to withstand oxidative stress compared to their younger counterparts. Expression of the short 28 kD SIRT3 isoform was higher, while the long 44 kD isoform expression was lower in young myocardial tissues compared with older ones. These results suggest that the active short isoform of SIRT3 protects hMSCs from oxidative injury by increasing the expression and activity of antioxidant enzymes. The expression of this short isoform decreases in cardiac tissue during ageing, leading to a reduced capacity for the heart to withstand oxidative stress.

A new cathode material with high energy density, high capacity and excellent cycling performance.

No abstract