Coupling Au with BO_(x) matrix induced by Closo-boron cluster for electrochemical synthesis of ammonia

Au is considered as one of the most promising catalysts for nitrogen reduction reaction(NRR),however maximizing the activity utilization rate of Au and understanding the synergistic effects between Au and carriers pose ongoing challenges.Herein,we systematically explore the synergistic catalytic effect of incorporating Au with boron clusters for accelerating NRR kinetics.An in-situ abinitio strategy is employed to construct B-doped Au nanoparticles(2-6 nm in diameter)loaded on BO_(x) substrates(AuBO_(x)),in which B not only modulates the surface electronic structure of Au but also forms strong coupling interactions to stabilize the nanoparticles.The electrochemical results show that Au-BO_(x) possesses excellent NRR activity(NH_(3) yield of 48.52μg h^(-1)mg_(cat)^(-1),Faraday efficiency of 56.18%),and exhibits high stability and reproducibility throughout the electrocatalytic NRR process.Theoretical calculations reveal that the introduction of B induces the formation of both Au dangling bond and Au-B coupling bond.which considerably facilitates the hydrogenation of~*N_(2)^(-)~*NH_(3).The present work provides a new avenue for the preparation of metal-boron materials achieved by one-step reduction and doping process,utilizing boron clusters as reducing and stabilizing agents.

Structure and immunomodulatory activity of Lentinus edodes polysaccharides modified by probiotic fermentation

Plant-based fermentations provide an untapped source for novel biotechnological applications.In this study,a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes.Polysaccharides were extracted from fermented and non-fermented L.edodes and purified via DEAE-52 and Sephadex G-100.The components designated F-LEP-2a and NF-LEP-2a were analyzed by FT-IR,HPGPC,HPAEC,SEM,GC-MS and NMR.The results revealed that probiotic fermentation increased the molecular weight from 1.16×10^(4) Da to 1.87×10^(4) Da and altered the proportions of glucose,galactose and mannose,in which glucose increased from 45.94%to 48.16%.Methylation analysis and NMR spectra indicated that F-LEP-2a and NF-LEP-2a had similar linkage patterns.Furthermore,their immunomodulatory activities were evaluated with immunosuppressive mice.NF-LEP and F-LEP improved immune organ indices,immunoglobulin(Ig G and Ig M)and cytokines concentrations;restored the antioxidation capacity of liver;and maintained the balance of gut microbiota.F-LEP displayed better moderating effects on the spleen index,immunoglobulin,cytokines and the diversity of gut microbiota than NF-LEP(200,400 mg/kg).Our study provides an efficient and environment-friendly way for the structural modification of polysaccharides,which helps to enhance their biological activity and promote their wide application in food,medicine and other fields.

Improved Diurnal Cycle of Precipitation on Land in a Global Non-Hydrostatic Model Using a Revised NSAS Deep Convective Scheme

In relatively coarse-resolution atmospheric models,cumulus parameterization helps account for the effect of subgridscale convection,which produces supplemental rainfall to the grid-scale precipitation and impacts the diurnal cycle of precipitation.In this study,the diurnal cycle of precipitation was studied using the new simplified Arakawa-Schubert scheme in a global non-hydrostatic atmospheric model,i.e.,the Yin-Yang-grid Unified Model for the Atmosphere.Two new diagnostic closures and a convective trigger function were suggested to emphasize the job of the cloud work function corresponding to the free tropospheric large-scale forcing.Numerical results of the 0.25-degree model in 3-month batched real-case simulations revealed an improvement in the diurnal precipitation variation by using a revised trigger function with an enhanced dynamical constraint on the convective initiation and a suitable threshold of the trigger.By reducing the occurrence of convection during peak solar radiation hours,the revised scheme was shown to be effective in delaying the appearance of early-afternoon rainfall peaks over most land areas and accentuating the nocturnal peaks that were wrongly concealed by the more substantial afternoon peak.In addition,the revised scheme enhanced the simulation capability of the precipitation probability density function,such as increasing the extremely low-and high-intensity precipitation events and decreasing small and moderate rainfall events,which contributed to the reduction of precipitation bias over mid-latitude and tropical land areas.

Influence of blasting load directions on tunnel stability in fractured rock mass

Tunnels in fractured rock masses are typically damaged by dynamic disturbances from various directions.To investigate the influence of blasting load directions on the stability of a tunnel with a precrack nearby,blasting tests were conducted on the physical models of an external crack around a tunnel(ECT)in this study.Failure modes of the tunnels were analysed based on stress wave theory.The Riedel-Hiermaier-Thoma(RHT)material model was employed to perform the numerical simulations on ECT models.Stress distribution around the tunnels and final failure patterns of the tunnels were characterised.The results show that,under blasting loads,the pre-crack propagates and then new cracks initiates on the incident side of the tunnel.These cracks extend towards each other and eventually coalesce.Blasting load directions significantly influence the ultimate failure mode of the tunnel in the fractured rock masses.The new cracks on the shadow side of the tunnel appear at different positions when the blasting stress waves come from various directions.The results are meaningful to the analysis of tunnel stability and optimisation of the tunnel support scheme.

Impact of Revised Trigger and Closure of the Double-Plume Convective Parameterization on Precipitation Simulations over East Asia

A double-plume convective parameterization scheme is revised to improve the precipitation simulation of a global model(Global-to-Regional Integrated Forecast System;GRIST).The improvement is achieved by considering the effects of large-scale dynamic processes on the trigger of deep convection.The closure,based on dynamic CAPE,is improved accordingly to allow other processes to consume CAPE under the more restricted convective trigger condition.The revised convective parameterization is evaluated with a variable-resolution model setup(110–35 km,refined over East Asia).The Atmospheric Model Intercomparison Project(AMIP)simulations demonstrate that the revised convective parameterization substantially delays the daytime precipitation peaks over most land areas,leading to an improved simulated diurnal cycle,evidenced by delayed and less frequent afternoon precipitation.Meanwhile,changes to the threshold of the trigger function yield a small impact on the diurnal amplitude of precipitation because of the consistent setting of dCAPE-based trigger and closure.The simulated mean precipitation remains reasonable,with some improvements evident along the southern slopes of the Tibetan Plateau.The revised scheme increases convective precipitation at the lower levels of the windward slope and reduces the large-scale precipitation over the upper slope,ultimately shifting the rainfall peak southward,which is in better agreement with the observations.

Multi-branched AgAuPt nanoparticles for efficient electrocatalytic hydrogen evolution:Synergism of tip-enhanced electric field effect and local electric field effect

High-curvature multi-noble metallic heterostructures can effectively enhance the electrocatalytic hydrogen evolution performance by utilizing the synergism of tip-enhanced electric field effect and local electric field effect.Herein,we report a two-step synthesis strategy to obtain multi-branched high-curvature Ag Au Pt heterostructure,firstly amino acids-induced growth of Au branches on Ag nanocubes,and secondly L-AA reduction of H_(2)PtCl_(6) to incorporate tiny Pt nanoparticles on Au branches.The D-CAgAuPt results in a low overpotential of 38 m V to deliver a cathodic current density of 10 m A cm^(-2),which is superior to commercial 20%Pt/C(46 m V).The strong electronic interactions between multi-noble metals intrinsically enhance the durability and stability of the catalysts.The intrinsic mechanism of promoting HER performance is investigated and revealed in-depth via the FDTD simulations and DFT calculations.In addition,D-CAg Au Pt can also achieve efficient and stable hydrogen evolution in a proton exchange membrane electrolyzer,which has the potential for commercial practical application.This work designs a novel multi-branched high-curvature multi-noble metallic heterostructure,and fully provides insights into the generical and efficient enhancement of electrocatalytic HER performance of multi-noble metallic heterostructures.

DRP1 deficiency induces mitochondrial dysfunction and oxidative stress-mediated apoptosis during porcine oocyte maturation

Background: Environmental pollution induces oxidative stress and apoptosis in mammalian oocytes, which can cause defects in reproduction;however, the molecular regulation of oxidative stress in oocytes is still largely unknown. In the present study, we identified that dynamin-related protein 1(DRP1) is an important molecule regulating oocyte mitochondrial function and preventing oxidative stress/apoptosis. DRP1 is a member of the dynamin GTPase superfamily localized at the mitochondrial-endoplasmic reticulum interaction site, where it regulates the fission of mitochondria and other related cellular processes.Results: Our results show that DRP1 was stably expressed during different stages of porcine oocyte meiosis, and might have a potential relationship with mitochondria as it exhibited similar localization. Loss of DRP1 activity caused failed porcine oocyte maturation and cumulus cell expansion, as well as defects in polar body extrusion.Further analysis indicated that a DRP1 deficiency caused mitochondrial dysfunction and induced oxidative stress,which was confirmed by increased reactive oxygen species levels. Moreover, the incidence of early apoptosis increased as detected by positive Annexin-V signaling.Conclusions: Taken together, our results indicate that DRP1 is essential for porcine oocyte maturation and that a DRP1 deficiency could induce mitochondrial dysfunction, oxidative stress, and apoptosis.

Boosting self-trapped exciton emission from Cs_(3)Cu_(2)I_(5)nanocrystals by doping-enhanced exciton-phonon coupling

Self-trapped excitons(STEs)emission from halide perovskites with strong exciton-phonon coupling has attracted considerable attention due to the widespread application in optoelectronic devices.Nevertheless,the in-depth understanding of the relationship between exciton-phonon coupling and luminescence intensity remains incomplete.Herein,a doping-enhanced exciton-phonon coupling effect is observed in Cs_(3)Cu_(2)I_(5)nanocrystals(NCs),which leads to a remarkable increasement of their STEs emission efficiency.Mechanism study shows that the hetero-valent substitution of Cu+with alkaline-earth metal ions(AE^(2+))causes a greater degree of Jahn-Teller distortion between the ground state and excited state structures of[Cu_(2)I_(5)]_(3)-clusters as evidenced by our spectral analysis and first-principles calculations.As a consequence,an X-ray detector based on these Cs_(3)Cu_(2)I_(5):AE NCs delivers an X-ray imaging resolution of up to 10 lp·mm^(-1) and a low detection limit of 0.37μGyair·s^(-1),disclosing the potential of doping-enhanced exciton-phonon coupling effect in improving STEs-emission and practical application for X-ray imaging.

lncR-GAS5 upregulates the splicing factor SRSF10 to impair endothelial autophagy,leading to atherogenesis

Long noncoding RNAs(lncRNAs)play a critical role in the regulation of atherosclerosis.Here,we investigated the role of the lncRNA growth arrest-specific 5(lncR-GAS5)in atherogenesis.We found that the enforced expression of lncR-GAS5 contributed to the development of atherosclerosis,which presented as increased plaque size and reduced collagen content.Moreover,impaired autophagy was observed,as shown by a decreased LC3II/LC3I protein ratio and an elevated P62 level in lncR-GAS5-overexpressing human aortic endothelial cells.By contrast,lncR-GAS5 knockdown promoted autophagy.Moreover,serine/arginine-rich splicing factor 10(SRSF10)knockdown increased the LC3II/LC3I ratio and decreased the P62 level,thus enhancing the formation of autophagic vacuoles,autolysosomes,and autophagosomes.Mechanistically,lncR-GAS5 regulated the downstream splicing factor SRSF10 to impair autophagy in the endothelium,which was reversed by the knockdown of SRSF10.Further results revealed that overexpression of the lncR-GAS5-targeted gene miR-193-5p promoted autophagy and autophagic vacuole accumulation by repressing its direct target gene,SRSF10.Notably,miR-193-5p overexpression decreased plaque size and increased collagen content.Altogether,these findings demonstrate that lncR-GAS5 partially contributes to atherogenesis and plaque instability by impairing endothelial autophagy.In conclusion,lncR-GAS5 overexpression arrested endothelial autophagy through the miR-193-5p/SRSF10 signaling pathway.Thus,miR-193-5p/SRSF10 may serve as a novel treatment target for atherosclerosis.

Macrophage-derived exosomal miR-342-3p promotes the progression of renal cell carcinoma through the NEDD4L/CEP55 axis

Due to its difficulty in early diagnosis and lack of sensitivity to chemotherapy and radiotherapy,renal cell carcinoma(RCC)remains to be a frequent cause of cancer-related death.Here,we probed into new targets for its early diagnosis and treatment for RCC.microRNA(miRNA)data of M2-EVs and RCC were searched on the Gene Expression Omnibus database,followed by the prediction of the potential downstream target.Expression of target genes was measured via RT-qPCR and Western blot,respectively.M2 macrophage was obtained viaflow cytometry with M2-EVs extracted.The binding ability of miR-342-3p to NEDD4L and to CEP55 ubiquitination was studied with their roles in the physical abilities of RCC cells assayed.Subcutaneous tumor-bearing mouse models and lung metastasis models were prepared to observe in vivo role of target genes.M2-EVs induced RCC growth and metastasis.miR-342-3p showed high expression in both M2-EVs and RCC cells.M2-EVs carrying miR-342-3p promoted RCC cell abilities to proliferate,invade and migrate.In RCC cells,M2-EV-derived miR-342-3p could specifically bind to NEDD4L and consequently elevate CEP55 protein expression via suppressing NEDD4L,thereby exerting tumor-promoting effects.CEP55 could be degraded by ubiquitination under the function of NEDD4L,and miR-342-3p delivered by M2-EVs facilitated the RCC occurrence and development by activating the PI3K/AKT/mTOR signaling pathway.In conclusion,M2-EVs promote RCC growth and metastasis by delivering miR-342-3p to suppress NEDD4L and subsequently inhibit CEP55 ubiquitination and degradation via activation of the PI3K/AKT/mTOR signaling pathway,strongly driving the proliferative,migratory and invasive of RCC cells.

Interfaces in Sulfide Solid Electrolyte‑Based All‑Solid‑State Lithium Batteries:Characterization,Mechanism and Strategy

Owing to the advantages of high energy density and environmental friendliness,lithium-ion batteries(LIBs)have been widely used as power sources in electric vehicles,energy storage systems and other devices.Conventional LIBs composed of liquid electrolytes(LEs)have potential safety hazards;thermal runaway easily leads to battery explosion and spontaneous combustion.To realize a large-scale energy storage system with higher safety and higher energy density,replacing LEs with solid-state electrolytes(SSEs)has been pursued.Among the many SSEs,sulfide SSEs are attractive because of their high ionic conductivities,easy processabilities and high thermostabilities.However,interfacial issues(interfacial reactions,chemo-mechanical failure,lithium dendrite formation,etc.)between sulfide SSEs and electrodes are factors limiting widespread application.In addition,the intrinsic interfacial issues of sulfide SSEs(electrochemical windows,diffusion mechanisms of Li^(+),etc.)should not be ignored.In this review,the behaviors,properties and mechanisms of interfaces in all-solid-state lithium batteries with a variety of sulfide SSEs are comprehensively summarized.Additionally,recent research progress on advanced characterization methods and designs used to stabilize interfaces is discussed.Finally,outlooks,challenges and possible interface engineering strategies are analyzed and proposed.

Correction:Interfaces in Sulfide Solid Electrolyte‑Based All‑Solid‑State Lithium Batteries:Characterization,Mechanism and Strategy

Correction to:Electrochemical Energy Reviews(2023)6:10 https://doi.org/10.1007/s41918-022-00176-0 The publication of this article unfortunately contained mistakes.The conflict of interest of one of the authors was missing.

光致变色吡啶三嗪鎓盐配体的合成和晶体结构

本文通过1,3,5-三(4-吡啶)-2,4,6-三嗪(TPT)三齿三角配体与对溴甲基苯甲酸的亲核取代设计合成了一例三取代吡啶鎓盐分子,并对其进行核磁、红外光谱和单晶X-射线衍射分析等结构表征。采用溶液挥发法得到的单晶结构分析表明,该配体属于正交晶系,空间群为Fdd2。该化合物具有良好的光致变色性能,通过光照前后的电子自旋共振光谱测试,发现光照后的样品出现强的吡啶鎓盐特征自由基顺磁信号(g = 2.0039)。

青藏高原盆栽一年生和多年生豆科牧草对土壤线虫群落的影响

查明一年生及多年生豆科牧草对土壤线虫群落的影响,可为青藏高原地区科学种植豆科牧草提供技术支撑。作者于2020–2022年在川西北红原县盆栽种植一年生光叶紫花苕(Viciavillosa,VV)和多年生紫花苜蓿(Medicagosativa,MS),以天然草地的植物作对照(control,CK)。每年9月下旬对土壤线虫组成、密度、多样性和营养类群,植物的高度、盖度、生物量及土壤理化性质进行调查。结果表明:(1)3种处理间的线虫群落组成结构存在差异,并随年际变化而增大;(2)光叶紫花苕的土壤线虫群落密度显著高于紫花苜蓿和对照,紫花苜蓿的线虫类群数和Shannon-Wiener指数显著高于光叶紫花苕和对照;随着年际变化,光叶紫花苕的线虫类群数及Shannon-Wiener指数、紫花苜蓿的线虫密度及Shannon-Wiener指数均显著下降;(3)光叶紫花苕的食真菌和植物寄生线虫密度显著高于紫花苜蓿和对照,捕食杂食线虫相对密度显著低于紫花苜蓿和对照;紫花苜蓿的植物寄生线虫相对密度显著低于光叶紫花苕和对照;随年际变化,光叶紫花苕的食细菌和植物寄生线虫相对密度分别显著下降和上升,紫花苜蓿和对照的食细菌线虫和食真菌线虫密度及食细菌线虫相对密度显著下降,捕食杂食线虫相对密度显著上升;(4)光叶紫花苕线虫群落的基础指数、结构指数和通道指数显著高于紫花苜蓿;(5)影响土壤线虫群落的主要环境因子主要为土壤pH、有效钾和植物群落高度、盖度和地上生物量。研究结果表明,一年生和多年生豆科牧草分别有利于维持较高的线虫群落密度和多样性,二者间作可能有利于提高线虫群落密度、多样性及生态功能。

Simulation of nonlinear vibration responses of cab system subject to suspension damper complete failure for trucks

The strong vibration responses of the cab system can be restrained by the damper force and the friction of the suspensions for trucks.After the failures of dampers,especially in the case of the complete failure,the anti vibration effect of the friction is prominent.However,the nonlinear vibration response characteristics of the cab subject to the damper complete failure have not been revealed.In order to reveal the nonlinear vibration response characteristics,a dynamic model of the cab system was established and its vibration equations were given.The friction forces existing in the suspensions were determined by the bench test.The influences of the friction forces on the cab vibration under different amplitude harmonic inputs were investigated when the dampers completely fail.The cab vertical displacement changes with the excitation amplitude and the vibration represents various motion states,including the periodic motion,the quasi-periodic motion,and the chaotic motion.The simulation results show that when the dampers fail,the proper friction forces help to suppress the quasi-periodic motion and the chaotic motion of the cab and to reduce the amplitude of the periodic motion.The proper friction forces can make the cab movement far away from the chaos area.They also help to avoid the fatigue damage of the cab floor and suspension parts to improve the service life of the suspension parts and to reduce the maintenance cost of the cab suspensions.

Modeling and analytic optimization of dynamic comfort for wheelchair robots undergoing random roads

To make a rapid comfort assessment and a reasonable dynamic parameters choice of wheelchair robots,this paper proposes a dynamic comfort coefficientκand analytically optimizes the cushion damping.Firstly,a traveling vibration model of the occupantwheelchair system for wheelchair robots running on random roads was created.Secondly,the analytic formula of the occupant RMS(root mean square)acceleration was deduced.Moreover,the dynamic coefficientκwas proposed and its influence laws were revealed.Finally,the cushion system optimal damping ratio was calculated based onκ.The results show that theκvalue is only determined by the parameters of the occupant-wheelchair system.The smaller theκvalue is,the better the dynamic comfort is for wheelchair robots running on random roads.By minimizingκ,the occupant-wheelchair system can achieve a statistically optimal dynamic comfort effect.

Analytical simulation of dynamic characteristics of seat system with nonlinear suspension considering friction effects

The friction inevitably exists in the nonlinear suspension system for seats.It affects dynamic characteristics of the seat with the nonlinear suspension system.Analysis of the influences of the friction on the seat vibration responses is helpful to improve comfort.Moreover,it is also an important part of promoting the industrialization application of the nonlinear suspension system for seats.In order to verify the influences,a model of the seat with the nonlinear suspension system considering friction effects was established by combining experiments.Based on the model,by using the harmonic balance method,the analytical formulas of the seat frequency-domain vibration response considering friction effects were deduced,and the influences of the friction on the frequency response characteristics of the system were simulated and analyzed.Moreover,the influences of the friction on the time-domain response characteristics were investigated.The results show that the existence of the friction can help to reduce the vibration in the peak region and to increase the system stability,however,it is not conducive to the improvement of the seat comfort under random road conditions.

Effects of feature selection on lane-change maneuver recognition:an analysis of naturalistic driving data

Purpose–Feature selection is crucial for machine learning to recognize lane-change(LC)maneuver as there exist a large number of feature candidates.Blindly using feature could take up large storage and excessive computation time,while insufficient feature selection would cause poor performance.Selecting high contributive features to classify LC and lane-keep behavior is effective for maneuver recognition.This paper aims to propose a feature selection method from a statistical view based on an analysis from naturalistic driving data.Design/methodology/approach–In total,1,375 LC cases are analyzed.To comprehensively select features,the authors extract the feature candidates from both time and frequency domains with various LC scenarios segmented by an occupancy schedule grid.Then the effect size(Cohen’s d)and p-value of every feature are computed to assess their contribution for each scenario.Findings–It has been found that the common lateral features,e.g.yaw rate,lateral acceleration and time-to-lane crossing,are not strong features for recognition of LC maneuver as empirical knowledge.Finally,cross-validation tests are conducted to evaluate model performance using metrics of receiver operating characteristic.Experimental results show that the selected features can achieve better recognition performance than using all the features without purification.Originality/value–In this paper,the authors investigate the contributions of each feature from the perspective of statistics based on big naturalistic driving data.The aim is to comprehensively figure out different types of features in LC maneuvers and select the most contributive features over various LC scenarios.

手性等离子体核壳纳米结构的设计及应用

手性描述了一个物体不能与其镜像重叠的几何性质,自19世纪以来一直是化学和生物学中的一个关键概念。随着纳米技术的发展,手性等离子体纳米材料凭借其特殊的手性光学性质和良好的生物相容性已经成为科学家们的研究重点和手性功能材料开发的热点。然而,较弱的手性响应信号限制了其应用和发展。将手性等离子体纳米材料和核壳结构结合得到的手性等离子体核壳纳米结构是一种放大手性响应信号的有效策略。核壳纳米结构整合了内外两种材料的性质,互相补充各自的不足,能够进一步改善材料的物理化学性质,提升材料在各个领域的性能。本文依据手性分子的空间分布对手性等离子体核壳纳米结构的设计策略进行了总结,并综述了其在超灵敏传感和手性催化领域的应用,分析了目前尚存在的问题和可能的解决方式,对其未来的发展作了进一步展望。

Research Article Acetic acid-mediated rapid cubic-to-hexagonal(α-β)phase transformation for ultra-bright lanthanide-dopedβ-NaYF_(4)nanobioprobes

Hexagonal-phase NaYF_(4)(β-NaYF_(4))has been acknowledged to be one of the most efficient doping hosts to prepare bright lanthanide-doped luminescent nano-bioprobes for various biomedical applications.However,to date,it remains a great challenge to synthesize ultra-bright lanthanide-dopedβ-NaYF_(4)nano-bioprobes under a low reaction temperature by using conventional synthetic methods.Herein,we first develop an acetic acid(HAc)-mediated coprecipitation method for the preparation of ultrabright lanthanide-dopedβ-NaYF_(4)nanoprobes under a low reaction temperature at 200℃.Based on a series of comparative spectroscopic investigations,we show that the use of HAc in the reaction environment can not only promote the rapidα-βphase transformation of NaYF_(4)host at 200℃ within 1 h but also boost the absolute photoluminescence quantum yield(PLQY)of NaYF_(4)nanocrystals to 30.68%for near-infrared emission and to 3.79%for upconversion luminescence,both of which are amongst the highest values for diverse lanthanide-doped luminescent nanocrystals ever reported.By virtue of their superior nearinfrared luminescence,we achieve optical-guided dynamic vasculature imaging in vivo of the whole body at a high spatial resolution(23.8μm)under 980 nm excitation,indicating its potential for the diagnosis and treatment evaluation of vasculaturerelated diseases.