Surpassing electrocatalytic limit of earth-abundant Fe^(4+)embedded in N-doped graphene for(photo)electrocatalytic water oxidation

Developing highly active,cost-effective,and environmental friendly oxygen evolution reaction(OER)electrocatalysts facilitates various(photo)electrochemical processes.In this work,Fe3N nanoparticles encapsulated into N-doped graphene nanoshells(Fe_(3)N@NG)as OER electrocatalysts in alkaline media were reported.Both the experimental and theoretical comparison between Fe_(3) N@NG and Fe_(3)N/NG,specifically including in situ Mossbauer analyses,demonstrated that the NG nanoshells improved interfacial electron transfer process from Fe_(3)N to NG to form high-valence Fe^(4+)ions(Fe^(4+)@NG),thus modifying electronic properties of the outer NG shells and subsequently electron transfer from oxygen intermediate to NG nanoshells for OER catalytic process.Meanwhile,the NG nanoshells also protected Fe-based cores from forming OER inactive and insulated Fe_(2)O_(3),leading to high OER stability.As a result,the as-formed Fe^(4+)@NG shows one of the highest electrocatalytic efficiency among reported Fe-based OER electrocatalysts,which can as well highly improve the photoelectrochemical water oxidation when used as the cocatalysts for the Fe_(2)O_(3) nanoarray photoanode.

Simvastatin Blocks Reinstatement of Cocaine-induced Conditioned Place Preference in Male Mice with Brain Lipidome Remodeling

Drug-associated reward memories are conducive to intense craving and often trigger relapse.Simvastatin has been shown to regulate lipids that are involved in memory formation but its influence on other cognitive processes is elusive.Here,we used a mass spectrometry-based lipidomic method to evaluate the impact of simvastatin on the mouse brain in a cocaine-induced reinstatement paradigm.We found that simvastatin blocked the reinstatement of cocaine-induced conditioned place preference(CPP)without affecting CPP acquisition.Specifically,only simvastatin administered during extinction prevented cocaine-primed reinstatement.Global lipidome analysis showed that the nucleus accumbens was the region with the greatest degree of change caused by simvastatin.The metabolism of fatty-acids,phospholipids,and triacylglycerol was profoundly affected.Simvastatin reversed most of the effects on phospholipids induced by cocaine.The correlation matrix showed that cocaine and simvastatin significantly reshaped the lipid metabolic pathways in specific brain regions.Furthermore,simvastatin almost reversed all changes in the fatty acyl profile and unsaturation caused by cocaine.In summary,pre-extinction treatment with simvastatin facilitates cocaine extinction and prevents cocaine relapse with brain lipidome remodeling.

Response of the sediment geochemistry of the Changjiang River(Yangtze River) to the impoundment of the Three Gorges Dam

Based on the measurement of major and trace elements in suspended sediments in the low reaches of the Changjiang River during throughout a whole hydrologic year, the origins, seasonal variations, and fluxes of multielements and the human impacts on multielements transport processes have been analyzed along with the influence of weathering in the Changjiang River basin. The results show that most element contents were high in both autumn and winter and low in summer, which was largely caused by the dilution of discharge. Weathering detritus in the Changjiang River basin is the main source of most elements in suspended sediments. However, riverine pollution could bring more loadings of Cd, Pb, As and Zn into river water than it did a few decades ago. The annual average fluxes of Cd, Pb and Zn, which are major contamination elements, to the sea were 179 ± 21 tons/year, 7810 ± 675 tons/year, and 12,000 ± 1320 tons/year,respectively, in which approximately 8.7%, 11.9% and 2.7% of their loadings, respectively,were contributed by pollution inputs. Element exports mainly occurred in the summer(44.4%–57.4%) in the lower part of the Changjiang River. A general relationship between sediment retention and element content suggests a positive feedback mechanism for the decreased number of particles, in which element riverine loadings are reduced due to the enhanced trapping effect by the Three Gorges Dam(TGD). Compared to those in 1980,current element shares of the Changjiang River compared to the global budget have declined due to the construction of the TGD.

Band degeneracy enhanced thermoelectric performance in layered oxyselenides by first-principles calculations

Band degeneracy is effective in optimizing the power factors of thermoelectric(TE)materials by enhancing the Seebeck coefficients.In this study,we demonstrate this effect in model systems of layered oxyselenide family by the density functional theory(DFT)combined with semi-classical Boltzmann transport theory.TE transport performance of layered LaCuOSe and BiCuOSe are fully compared.The results show that due to the larger electrical conductivities caused by longer electron relaxation times,the n-type systems show better TE performance than p-type systems for both LaCuOSe and BiCuOSe.Besides,the conduction band degeneracy of LaCuOSe leads to a larger Seebeck coefficient and a higher optimal carrier concentration than n-type BiCuOSe,and thus a higher power factor.The optimal figure of merit(ZT)value of 1.46 for n-type LaCuOSe is 22%larger than that of 1.2 for n-type BiCuOSe.This study highlights the potential of wide band gap material LaCuOSe for highly efficient TE applications,and demonstrates that inducing band degeneracy by cations substitution is an effective way to enhance the TE performance of layered oxyselenides.

Histone deacetylase 8 regulates NF-κB-related inflammation in asthmatic mice through H3K9 acetylation

To the Editor:Bronchial asthma is a respiratory disease with pathological features that mainly comprise changes in airway inflammation,airway remodeling,and airway hyperresponsiveness.