Notch pathway inhibitor DAPT enhances Atoh1 activity to generate new hair cells in situ in rat cochleae

Atoh1 overexpression in cochlear epithelium induces new hair cell formation. Use of adenovirus-mediated Atoh1 overexpression has mainly focused on the rat lesser epithelial ridge and induces ectopic hair cell regeneration. The sensory region of rat cochlea is difficult to transfect, thus new hair cells are rarely produced in situ in rat cochlear explants. After culturing rat cochleae in medium containing 10% fetal bovine serum, adenovirus successfully infected the sensory region as the width of the supporting cell area was significantly increased. Adenovirus encoding Atoh1 infected the sensory region and induced hair cell formation in situ. Combined application of the Notch inhibitor DAPT and Atoh1 increased the Atoh1 expression level and decreased hes1 and hes5 levels, further promoting hair cell generation. Our results demonstrate that DAPT enhances Atoh1 activity to promote hair cell regeneration in rat cochlear sensory epithelium in vitro.

First-principles insight into Li and Na ion storage in graphene oxide

The structural, electronic, and adsorption properties of Li/Na ions on graphene decorated by epoxy groups are investigated by first-principles calculations based on density functional theory.Our results show that the concentration of epoxy groups remarkably affects the structural and electronic properties of graphene.The bandgaps change monotonically from0.16 eV to 3.35 eV when the O coverage increases from 12.5% to 50%(O/C ratio).Furthermore, the highest lithiation potential of 2.714 V is obtained for the case of graphene oxide(GO) with 37.5 % O coverage, while the highest sodiation potential is 1.503 V for GO with 12.5% O coverage.This clearly demonstrates that the concentration of epoxy groups has different effects on Li and Na storage in GO.Our results provide a new insight into enhancing the Li and Na storage by tuning the concentration of epoxy groups on GO.

Configurational entropy-induced phase transition in spinel LiMn_(2)O_(4)

The spinel-type LiMn_(2)O_(4) is a promising candidate as cathode material for rechargeable Li-ion batteries due to its good thermal stability and safety.Experimentally,it is observed that in this compound there occur the structural phase transitions from cubic(Fd3m)to tetragonal(I4_(1)/amd)phase at slightly below room temperature.To understand the phase transition mechanism,we compare the Gibbs free energy between cubic phase and tetragonal phase by including the configurational entropy.Our results show that the configurational entropy contributes substantially to the stability of the cubic phase at room temperature due to the disordered Mn^(3+)/Mn^(4+)distribution as well as the orientation of the Jahn-Teller elongation of the Mn^(3+)O_(6) octahedron in the the spinel phase.Meanwhile,the phase transition temperature is predicted to be 267.8 K,which is comparable to the experimentally observed temperature.These results serve as a good complement to the experimental study,and are beneficial to the improving of the electrochemical performance of LiMn_(2)O_(4) cathode.