Exploring the role of iron in Fe_(5)Ni_(4)S_(8)toward oxygen evolution through modulation of electronic orbital occupancy

Ni-Fe-based catalysts are considered to be among the most active catalysts for the oxygen evolution reaction(OER)under alkaline conditions,with Fe playing a crucial role.However,Fe leaching occurs during the reaction due to thermodynamic instability,which has resulted in conflicting reports within the literature regarding its role.To clarify this point,we propose a strategy consisting of modulating the electronic orbital occupancy to suppress the extensive loss of Fe atoms during the OER process.Theoretical calculations,in-situ X-ray photoelectron spectroscopy,molecular dynamics simulations,and a series of characterization showed that the stable presence of Fe not only accelerates the electron transfer process but also optimizes the reaction barriers of the oxygen evolution intermediates,promoting the phase transition of Fe_(5)Ni_(4)S_(8)to highly active catalytic species.The modulated Fe_(5)Ni_(4)S_(8)-based pre-catalysts exhibit improved OER activity and long-term durability.This study provides a novel perspective for understanding the role of Fe in the OER process.

Enhanced reconstruction of Fe_(5)Ni_(4)S_(8) by implanting pyrrolidone to unlock efficient oxygen evolution

During oxygen evolution reaction(OER),complex changes have been reported on surfaces of bimetallic Fe-Ni-based catalysts,and regulating the dynamic evolution could improve their electrocatalytic performances.Herein,a pyrrolidone-promoted reconstruction of pentlandite was investigated to uncover the correlation between the reconstructed surface and the OER performance.The theoretical calculations indicated the preferential implantation of pyrrolidone at Fe atoms,useful for regulating the electronic structures of pentlandite.The vale nce state of Ni increased,suggesting the promotion of the in-situ reconstruction of pentlandite via strengthening hydroxyl adsorption to generate highly active NiOOH.The electron-rich pentlandite was also found conducive to charge transfer under applied voltages.The Operando Raman and various quasi-in-situ characterizations confirmed the realization of more delocalized electronic structures of pentlandite by introducing pyrrolidone.This,in turn,promoted the accumulation of hydroxyl groups on the pentlandite surface,thereby boosting the formation of highly active NiOOH at lower OER potentials.Consequently,the adsorption energies of intermediates were optimized,conducive to enhanced OER reaction kinetics.As a proof of concept,the pentlandite decorated by pyrrolidone exhibited an overpotential as low as 265 mV at 10 mA cm^(-2) coupled with stable catalysis for 1000 hours at a high current density of 100 mA cm^(-2).In sum,new insights into unlocking the high catalytic activity of bimetallic Fe-Ni-based catalysts were provided,promising for future synthesis of advanced catalysts.

Ca^(2+)-independent ZmCPK2 is inhibited by Ca^(2+)-dependent ZmCPK17 during drought response in maize

Calcium oscillations are induced by different stresses.Calcium-dependent protein kinases(CDPKs/CPKs)are one major group of the plant calcium decoders that are involved in various processes including drought response.Some CPKs are calcium-independent.Here,we identified ZmCPK2 as a negative regulator of drought resistance by screening an overexpression transgenic maize pool.We found that ZmCPK2 does not bind calcium,and its activity is mainly inhibited during short term abscisic acid(ABA)treatment,and dynamically changed in prolonged treatment.Interestingly,ZmCPK2 interacts with and is inhibited by calcium-dependent ZmCPK17,a positive regulator of drought resistance,which is activated by ABA.ZmCPK17 could prevent the nuclear localization of ZmCPK2 through phosphorylation of ZmCPK2T60.ZmCPK2 interacts with and phosphorylates and activates ZmYAB15,a negative transcriptional factor for drought resistance.Our results suggest that drought stress-induced Ca^(2+)can be decoded directly by ZmCPK17 that inhibits ZmCPK2,thereby promoting plant adaptation to water deficit.

A survey of ictal physical examination during VEEG monitoring in a tertiary epilepsy center

Background Ictal examination based on video-based electroencephalography(EEG)is crucial for locating and lat-eralizing seizures.In this study,we aimed to evaluate the quality of ictal examination in the Comprehensive Epilepsy Center of West China Hospital,Sichuan University,in order to provide information for quality improvement in daily clinical practice.Methods Video recordings of 100 patients with epilepsy were retrospectively reviewed.The performance of the ictal examination was independently reviewed by two epileptologists using an ictal examination protocol.Results In this retrospective analysis,589 seizure episodes from 100 patients with epilepsy were reviewed.The ages of the patients ranged from 3 to 77 years,with a mean age of 25.8±12.8 years.Among the 589 seizure episodes,a majority(93.7%)were focal seizures.For 226(38.4%)seizures,the medical staff arrived at the bedside.Among them,153(153/226,64.7%)seizure episodes,the medical staff arrival at the bedside within 30 s of onset,and 120(120/226,53.1%)seizures were tested by the medical staff.The compliance rates for"safety"and"visibility"reached 80%or higher while"naming","retelling",and“memory testing”only reach less than 3%.Conclusions Our survey identified the main problems in ictal assessments.It is challenging to complete a standard-ized examination for new trainees at Epilepsy Monitoring Units.Regularly strengthening training in ictal examination and understanding of semiology may improve patients’examination ability.However,further study of the implemen-tation of training is necessary.

Biodegradable,superhydrophobic walnut wood membrane for the separation of oil/water mixtures

The preparation of environmentally friendly oil/water separation materials remains a great challenge.Freeze-drying of wood after lignin removal yields wood aerogels,which can be used as substrates to prepare fluorine-free environmentally friendly superhydrophobic materials,However,they are more suitable for absorption rather than filtration applications due to their poor strength.A study using cross-sections of pristine wood chips as substrates retains the original strength of wood,but the use of the cross-sectional of wood pieces limits their thickness,strength,and size.In this paper,a degradable fluorine-free superhydrophobic film(max.water contact angle of approximately 164.2°)with self-cleaning and abrasion resistance characteristics was prepared by a one-step method using pristine and activated walnut longitudinal section films as the substrate,with tetraethyl orthosilicate as a precursor and dodecyltriethoxysilane as a modifier.The tensile strength results show that superhydrophobic films with pristine or activated wood substrates maintained the strength of pristine wood and were 2.2 times stronger than the wood aerogel substrate.In addition,after cross-laminating the two samples,the films had the ability to separate oil and water by continuous filtration with high efficiency(98.5%)and flux(approximately 1.3×10^(3)L∙m^(‒2)∙h^(‒1)).The method has potential for the large-scale fabrication of degradable superhydrophobic filtration separation membranes.