Tea-derived carbon materials as anode for high-performance sodium ion batteries

Sodium-ion batteries(SIB) have attracted widespread attention in large-scale energy storage fields owing to the abundant reserve in the earth and similar properties of sodium to lithium. Biomass-based carbon materials with low-cost, controllable structure, simple processing technology, and environmental friendliness tick almost all the right boxes as one of the promising anode materials for SIB. Herein, we present a simple novel strategy involving tea tomenta biomass-derived carbon anode with enhanced interlayer carbon distance(0.44 nm) and high performance, which is constructed by N,P co-doped hard carbon(Tea-1100-NP) derived from tea tomenta. The prepared Tea-1100-NP composite could deliver a high reversible capacity(326.1 m Ah/g at 28 m A/g), high initial coulombic efficiency(ICE = 90% at 28 m A/g),stable cycle life(262.4 m Ah/g at 280 m A/g for 100 cycles), and superior rate performance(224.5 m Ah/g at 1400 m A/g). Experimental results show that the excellent electrochemical performance of Tea-1100-NP due to the high number of active N,P-containing groups, and disordered amorphous structures provide ample active sites and increase the conductivity, meanwhile, large amounts of microporous shorten the Na+diffusion distance as well as quicken ion transport. This work provides a new type of N,P co-doped high-performance tomenta-derived carbon, which may also greatly promote the commercial application of SIB.

SALL4 maintains self-renewal of porcine pluripotent stem cells through downregulation of OTX2

Sall4 as one of the spalt family members contains several alternative splicing variants, which are differentially expressed and has a key role in maintaining pluripotent stem cells. However, the molecular features and function of SALL4 have not been well elucidated in porcine induced pluripotent stem cells(piPSCs). In this study, we identi?ed SALL4 splice variants and found two SALL4 splicing variants through analysis of the porcine transcriptome data derived from piPSCs. SALL4 A was only detected in piPSCs but SALL4 B was globally expressed in porcine tissues and piPSCs. The level of SALL4 B was signi?cantly reduced when piPSCs differentiation occurred, however, the expression of SALL4 A was not affected, indicating that SALL4 B may be essential for the maintenance of piPSCs self-renewal. Overexpression of SALL4 A and SALL4 B in PEF cells could signi?cantly stimulated expression of endogenous pluripotent genes,when SALL4 B signi?cantly promoted OCT4 expression.Conversely, SALL4 A signi?cantly promoted KLF4 expression. Additionally, both SALL4 A and SALL4 B could repress OTX2 promoter activity in a dose-dependent manner. Conversely, OTX2 also negatively regulated SALL4 expression. These observations indicate that a negative feedback regulatory mechanism may exist between SALL4 and OTX2, which is useful for the maintenance of the self-renewal of piPSCs.