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China Foundry 2024年第2期21卷 168-174页

作者： Zhi-yong Zhang jiao-jiao Cheng Jia-qi xie Shi-bing Liu Kun Shi Jun Zhao Shenyang Research Institute of Foundry Co. Ltd.CAMShenyang 110022China National Key Laboratory of Advanced Casting Technologies Shenyang 110022China

Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high modulus.In this study,the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy and casting technique.Microstructural characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were evaluated.Results revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and TiC.However,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like morphology.Microhardness increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature elongation.Conversely,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.

关键词： titanium matrix composites microstucture microhardness tensile properties in-situ synthesis

Exposure to ephedrine attenuates Th1/Th2 imbalance underlying OVA-induced asthma through airway epithelial cell-derived exo-somal lnc-TRPM2-AS

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Chinese Journal of Natural Medicines 2024年第6期22卷 530-540页

作者： HU Yan WANG Mengqing xie Jing jiao Luojia DING Yi LUO Yinhe Department of Pediatrics The First Hospital of Hunan University of Chinese MedicineChangsha 410007China Hunan University of Chinese Medicine Changsha 410208China Department of Rehabilitation Medical CollegeChangsha Civil Affairs Vocational and Technical CollegeChangsha 410004Hunan ProvinceChina Teaching and Research Office of Chinese and Western Combination Hunan University of Chinese MedicineChangsha 410208China

Although various anti-inflammatory medications,such as ephedrine,are employed to manage cough-variant asthma,their underlying mechanisms are yet to be fully understood.Recent studies suggest that exosomes derived from airway epithelial cells(AECs)contain components like messenger RNAs(mRNAs),micro-RNAs(miRNAs),and long noncoding RNA(lncRNA),which play roles in the occurrence and progression of airway inflammation.This study investigates the influence of AEC-derived exosomes on the efficacy of ephedrine in treating cough-variant asthma.We established a mouse model of asthma and measured airway resist-ance and serum inflammatory cell levels.Real-time polymerase chain reaction(RT-qPCR),Western blotting,and enzyme-linked im-munosorbent assay(ELISA)analyses were used to assess gene and protein expression levels.Exosomes were isolated and character-ized.RNA immunoprecipitation(RIP)and RNA pull-down assays were conducted to examine the interaction between hnRNPA2B1 and lnc-TRPM2-AS1.In the ovalbumin(OVA)-challenged mouse model,ephedrine treatment reduced inflammatory responses,air-way resistance,and Th1/Th2 cell imbalance.Exosomes from OVA-treated AECs showed elevated levels of lnc-TRPM2-AS1,which were diminished following ephedrine treatment.The exosomal lnc-TRPM2-AS1 mediated the Th1/Th2 imbalance in CD4^(+)T cells,with its packaging into exosomes being facilitated by hnRNPA2B1.This study unveils a novel mechanism by which ephedrine ameli-orates OVA-induced CD4^(+)T cell imbalance by suppressing AEC-derived exosomal lnc-TRPM2-AS1.These findings could provide a theoretical framework for using ephedrine in asthma treatment.

关键词： Asthma Ephedrine Exosomal lnc-TRPM2-AS1 Th1/Th2 imbalance HnRNPA2B1 Airway epithelial cells

Insight study of rare earth elements in PM_(2.5)during five years in a Chinese inland city:Composition

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Journal of Environmental Sciences 2024年第4期138卷 439-449页

作者： Yi-Wen Shen Chang-Xian Zhao Hao Zhao Shuo-Fei Dong Qi Guo jiao-jiao xie Mei-Ling Lv Chun-Gang Yuan Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control Department ofEnvironmental Science&EngineeringNorth China Electric Power UniversityBaoding 071000China MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing 102206China Agilent Technologies Co.Ltd.(China) Beijing 100102China

The booming development of rare earth industry and the extensive utilization of its products accompanied by urban development have led to the accelerated accumulation of rare earth elements(REEs)as emerging pollutants in atmospheric environment.In this study,the variation of REEs in PM_(2.5)with urban(a non-mining city)transformation was investigated through five consecutive years of sample collection.The compositional variability and provenance contribution of REEs in PM_(2.5)were characterized,and the REEs exposure risks of children and adults via inhalation,ingestion and dermal absorption were also evaluated.The results showed an increase in the total REEs concentration from 46.46±35.16 mg/kg(2017)to 81.22±38.98 mg/kg(2021)over the five-year period,with Ce and La making the largest contribution.The actual increment of industrial and traffic emission source among the three pollution sources was 1.34 ng/m^(3).Coal combustion source displayed a downward trend.Ingestion was the main exposure pathway for REEs in PM_(2.5)for both children and adults.Ce contributed the most to the total intake of REEs in PM_(2.5)among the population,followed by La and Nd.The exposure risks of REEs in PM_(2.5)in the region were relatively low,but the trend of change was of great concern.It was strongly recommended to strengthen the concern about traffic-related non-exhaust emissions of particulate matter.

关键词： Rare earth elements Exposure risks Pollution sources Traffic-related non-exhaust emissions

Physiological,transcriptome and gene functional analysis provide novel sights into cadmium accumulation and tolerance mechanisms in kenaf

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Journal of Environmental Sciences 2024年第3期137卷 500-514页

作者： Shan Cao Meng Wang jiao Pan Dengjie Luo Samavia Mubeen Caijin Wang jiao Yue Xia Wu Qijing Wu Hui Zhang Canni Chen Muzammal Rehman Sichen xie Ru Li Peng Chen Guangxi Key Laboratory of Agro-environment and Agric-products safety Key Laboratory of Plant Genetics and BreedingCollege of AgricultureGuangxi UniversityNanning 530004China State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources College of Life Science and TechnologyGuangxi UniversityNanning 530004China

Kenaf is considered to have great potential for remediation of heavy metals in ecosystems.However,studies on molecular mechanisms of root Cd accumulation and tolerance are still inadequate.In this study,two differently tolerant kenaf cultivars were selected as materials and the physiological and transcriptomic effects were evaluated under Cd stress.This study showed that 200μmol/L CdCl_(2) treatment triggered the reactive oxygen species(ROS)explosion and membrane lipid peroxidation.Compared with the Cd-sensitive cultivar‘Z',the Cd-tolerant cultivar‘F'was able to resist oxidative stress in cells by producing higher antioxidant enzyme activities and increasing the contents of ascorbic acid(AsA)and glutathione(GSH).The root cell wall of‘F'exhibited higher polysaccharide contents under Cd treatment,providing more Cd-binding sites.There were 3,439 differentially expressed genes(DEGs)that were co-regulated by Cd treatment in two cultivars.Phenylpropanoid biosynthesis and plant hormone signal transduction pathways were significantly enriched by functional annotation analysis.DEGs associated with pectin,cellulose,and hemi-cellulose metabolism were involved in Cd chelation of root cell wall;V-ATPases,ABCC3 and Narmp3 could participated in vacuolar compartmentalization of Cd;PDR1 was responsible for Cd effux;the organic acid transporters contributed to the absorption of Cd in soil.These genes might have played key roles in kenaf Cd tolerance and Cd accumulation.Moreover,HcZIP2 was identified to be involved in Cd uptake and transport in kenaf.Our findings provide a deeper understanding of the molecular pathways underlying Cd accumulation and detoxification mechanisms in kenaf.

关键词： Kenaf Cd stress Physiological Transcriptome HcZIP2

Vitamin D-binding protein in plasma microglia-derived extracellular vesicles as a potential biomarker for major depressive disorder

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Genes & Diseases 2024年第2期11卷 1009-1021页

作者： Gaojia Zhang Ling Li Yan Kong Dandan Xu Yu Bao Zhiting Zhang Zhixiang Liao jiao jiao Dandan Fan Xiaojing Long Ji Dai Chunming xie Zhiqiang Meng Zhijun Zhang Department of Neurology Affiliated Zhongda HospitalResearch Institution of NeuropsychiatrySchool of MedicineSoutheast UniversityNanjingJiangsu 210009China Department of Biochemistry and Molecular Biology School of MedicineSoutheast UniversityNanjingJiangsu 210009China Shenzhen Key Laboratory of Drug Addiction Brain Cognition and Brain Disease InstituteShenzhen Institute of Advanced TechnologyChinese Academy of Sciences (CAS)ShenzhenGuangdong 518000China CAS Key Laboratory of Brain Connectome and Manipulation The Brain Cognition and Brain Disease Institute (BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518055China Lauterbur Research Center for Biomedical Imaging Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518055China Shenzhen-Hong Kong Institute of Brain Sciences-Shenzhen Fundamental Research Institutions ShenzhenGuangdong 518000China Brain Cognition and Brain Disease Institute Department of Mental Health and Public HealthFaculty of Life and Health SciencesShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518055China

No well-established biomarkers are available for the clinical diagnosis of major depressive disorder(MDD).Vitamin D-binding protein(VDBP)is altered in plasma and postmortem dorsolateral prefrontal cortex(DLPFC)tissues of MDD patients.Thereby,the role of VDBP as a potential biomarker of MDD diagnosis was further assessed.Total extracellular vesicles(EVs)and brain cell-derived EVs(BCDEVs)were isolated from the plasma of first-episode drug-naïve or drug-free MDD patients and well-matched healthy controls(HCs)in discovery(20 MDD patients and 20 HCs)and validation cohorts(88 MDD patients and 38 HCs).VDBP level in the cerebrospinal fluid(CSF)from chronic glucocorticoid-induced depressed rhesus macaques or prelimbic cortex from lipopolysaccharide(LPS)-induced depressed mice and wild control groups was measured to evaluate its relationship with VDBP in plasma microglia-derived extracellular vesicles(MDEVs).VDBP was significantly decreased in MDD plasma MDEVs compared to HCs,and negatively correlated with HAMD-24 score with the highest diagnostic accuracy among BCDEVs.VDBP in plasma MDEVs was decreased both in depressed rhesus macaques and mice.A positive correlation of VDBP in MDEVs with that in CSF was detected in depressed rhesus macaques.VDBP levels in prelimbic cortex microglia were negatively correlated with those in plasma MDEVs in depressed mice.The main results suggested that VDBP in plasma MDEVs might serve as a prospective candidate biomarker for MDD diagnosis.

关键词： Biomarker Cerebrospinal fluid Major depressive disorder Microglia derived extracellular vesicles Vitamin-D binding protein

Evolution model and failure mechanisms of rainfall-induced cracked red clay slopes:insights from Xinshao County,China

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Journal of Mountain Science 2024年第3期21卷 867-881页

作者： jiao Weizhi ZHANG Ming LI Peng xie Junjin PANG Haisong LIU Fuxing YANG Long Faculty of Engineering China University of GeosciencesWuhan 430074China

Red clay landslides are widely distributed worldwide,resulting in severe loss of life and property.Although rainfall-induced red clay slopes have received extensive attention,the role of cracks in the evolutionary process of red clay slopes and their connection to failure mechanisms is still poorly understood.A comprehensive approach integrating field investigation,laboratory tests,and numerical simulations was conducted to study the 168 red clay landslides in Xinshao County,China.The results show that red clay is prone to forming cracks at high moisture content due to its low swelling and high shrinkage properties.The failure mode of red clay slopes can be summarized in three stages:crack generation,slope excavation,and slope failure.Furthermore,the retrospective analysis and numerical simulations of the typical landslide in Guanchong indicated that intense rainfall primarily impacts the shallow layer of soil within approximately 0.5 m on the intact slope.However,cracks change the pattern of rainfall infiltration in the slope.Rainwater infiltrates rapidly through the preferential channels induced by the cracks rather than uniformly and slowly from the slope surface.This results in a significant increase in both the depth of infiltration and the saturated zone area of the cracked slope,reaching 3.8 m and 36.2 m^(2),respectively.Consequently,the factor of safety of the slope decreases by 13.4%compared to the intact slope,ultimately triggering landslides.This study can provide valuable insights into understanding the failure mechanisms of red clay slopes in China and other regions with similar geological settings.

关键词： Red clay slopes Cracks Preferential flow Failure mechanism

Disulfide bridge-targeted metabolome mining unravels an antiparkinsonian peptide

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Acta Pharmaceutica Sinica B 2024年第2期14卷 881-892页

作者： Zhiwu Tong Xiahong xie Huiming Ge Ruihua jiao Tingting Wang Xincun Wang Wenying Zhuang Gang Hu Renxiang Tan State Key Laboratory of Pharmaceutical Biotechnology Institute of Functional BiomoleculesSchool of Life SciencesNanjing UniversityNanjing 210023China State Key Laboratory Cultivation Base for TCM Quality and Efficacy Nanjing University of Chinese MedicineNanjing 210023China Institute of Microbiology Chinese Academy of SciencesBeijing 100101China

Peptides are a particular molecule class with inherent attributes of some small-molecule drugs and macromolecular biologics,thereby inspiring continuous searches for peptides with therapeutic and/or agrochemical potentials.However,the success rate is decreasing,presumably because many interesting but less-abundant peptides are so scarce or labile that they are likely‘overlooked’during the characterization effort.Here,we present the biochemical characterization and druggability improvement of an unprecedented minor fungal RiPP(ribosomally synthesized and post-translationally modified peptide),named acalitide,by taking the relevant advantages of metabolomics approach and disulfide-bridged substructure which is more frequently imprinted in the marketed peptide drug molecules.Acalitide is biosynthetically unique in the macrotricyclization via two disulfide bridges and a protease(AcaB)-catalyzed lactamization of AcaA,an unprecedented precursor peptide.Such a biosynthetic logic was successfully re-edited for its sample supply renewal to facilitate the identification of the in vitro and in vivo antiparkinsonian efficacy of acalitide which was further confirmed safe and rendered brain-targetable by the liposome encapsulation strategy.Taken together,the work updates the mining strategy and biosynthetic complexity of RiPPs to unravel an antiparkinsonian drug candidate valuable for combating Parkinson’s disease that is globally prevailing in an alarming manner.

关键词： Fungal RiPPs Biosynthesis Macrocyclic peptide Acalitide Antiparkinsonian

Aero-Hydro-Elastic-Servo Modeling and Dynamic Response Analysis of A Monopile Offshore Wind Turbine Under Different Operating Scenarios

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China Ocean Engineering 2024年第3期38卷 379-393页

作者： xie Shuang-yi GAO Jian LI Yong-ran JIANG Shu-xin ZHANG Cheng-lin HE jiao College of Mechanical Engineering Chongqing University of TechnologyChongqing 400044China Beijing Institute of Precision Mechatronics and Controls Beijing 100076China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China Fishery Machinery and Instrument Research Institute Chinese Academy of Fishery SciencesShanghai 200092China School of Mechanical and Power Engineering Chongqing University of Science&TechnologyChongqing 401331China

This paper constructs a coupled aero-hydro-elastic-servo simulation framework for a monopile offshore wind turbine(OWT).In this framework,a detailed multi-body dynamics model of the monopile OWT including the gearbox,blades,tower and other components(nacelle,hub,bedplate,etc.)has been explicitly established.The effects of pile−soil interaction,controller and operational conditions on the turbine dynamic responses are studied systematically in time domain and frequency domain.The results show that(1)a comprehensive drivetrain model has the capability to provide a more precise representation of the complex dynamic characteristics exhibited by drivetrain components,which can be used as the basis for further study on the dynamic characteristics of the drivetrain.(2)The pile−soil interaction can influence the wind turbine dynamic responses,particularly under the parked condition.(3)The effect of the pile−soil interaction on tower responses is more significant than that on blade responses.(4)The use of the controller can substantially affect the rotor characteristics,which in turn influences the turbine dynamic responses.(5)The tower and blade displacements under the operational condition are much larger than those under the parked condition.The model and methodology presented in this study demonstrate potential for examining complex dynamic behaviors of the monopile OWTs.To ensure accuracy and precision,it is imperative to construct a detailed model of the wind turbine system,while also taking into account simulation efficiency.

关键词： offshore wind turbine(OWT) pile−soil interaction dynamic response parked condition operating condition

UAV-Assisted Dynamic Avatar Task Migration for Vehicular Metaverse Services: A Multi-Agent Deep Reinforcement Learning Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 430-445页

作者： Jiawen Kang Junlong Chen Minrui Xu Zehui Xiong Yutao jiao Luchao Han Dusit Niyato Yongju Tong Shengli xie IEEE School of Automation Guangdong University of TechnologyGuangzhou 510006China 111 Center for Intelligent Batch Manufacturing based on IoT Technology Guangzhou 510006China Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China School of Computer Science and Engineering Nanyang Technological UniversitySingaporeSingapore Pillar of Information Systems Technology and Design Singapore University of Technology and DesignSingaporeSingapore College of Communication Engineering Army Engineering University of PLANanjing 210007China National Natural Science Foundation of China Beijing 100085China Key Laboratory of Intelligent Detection and IoT in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong Key Laboratory of IoT Information Technology Guangzhou 510006China

Avatars, as promising digital representations and service assistants of users in Metaverses, can enable drivers and passengers to immerse themselves in 3D virtual services and spaces of UAV-assisted vehicular Metaverses. However, avatar tasks include a multitude of human-to-avatar and avatar-to-avatar interactive applications, e.g., augmented reality navigation,which consumes intensive computing resources. It is inefficient and impractical for vehicles to process avatar tasks locally. Fortunately, migrating avatar tasks to the nearest roadside units(RSU)or unmanned aerial vehicles(UAV) for execution is a promising solution to decrease computation overhead and reduce task processing latency, while the high mobility of vehicles brings challenges for vehicles to independently perform avatar migration decisions depending on current and future vehicle status. To address these challenges, in this paper, we propose a novel avatar task migration system based on multi-agent deep reinforcement learning(MADRL) to execute immersive vehicular avatar tasks dynamically. Specifically, we first formulate the problem of avatar task migration from vehicles to RSUs/UAVs as a partially observable Markov decision process that can be solved by MADRL algorithms. We then design the multi-agent proximal policy optimization(MAPPO) approach as the MADRL algorithm for the avatar task migration problem. To overcome slow convergence resulting from the curse of dimensionality and non-stationary issues caused by shared parameters in MAPPO, we further propose a transformer-based MAPPO approach via sequential decision-making models for the efficient representation of relationships among agents. Finally, to motivate terrestrial or non-terrestrial edge servers(e.g., RSUs or UAVs) to share computation resources and ensure traceability of the sharing records, we apply smart contracts and blockchain technologies to achieve secure sharing management. Numerical results demonstrate that the proposed approach outperforms the MAPPO approach by around 2% and

关键词： Avatar blockchain metaverses multi-agent deep reinforcement learning transformer UAVs

Variation Characteristics of Root Traits of Different Alfalfa Cultivars under Saline-Alkaline Stress and their Relationship with Soil Environmental Factors

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Phyton-International Journal of Experimental Botany 2024年第1期93卷 29-43页

作者： Tian-jiao Wei Guang Li Yan-Ru Cui jiao xie Xing-Ai Gao Xing Teng Xin-Ying Zhao Fa-Chun Guan Zheng-Wei Liang Northeast Agricultural Research Center of China Jilin Academy of Agricultural SciencesChangchun130033China Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun130102China

Soil salinization is the main factor that threatens the growth and development of plants and limits the increase of yield.It is of great significance to study the key soil environmental factors affecting plant root traits to reveal the adaptation strategies of plants to saline-alkaline-stressed soil environments.In this study,the root biomass,root morphological parameters and root mineral nutrient content of two alfalfa cultivars with different sensitivities to alkaline stress were analyzed with black soil as the control group and the mixed saline-alkaline soil with a ratio of 7:3 between black soil and saline-alkaline soil as the saline-alkaline treatment group.At the same time,the correlation analysis of soil salinity indexes,soil nutrient indexes and the activities of key enzymes involved in soil carbon,nitrogen and phosphorus cycles was carried out.The results showed that compared with the control group,the pH,EC,and urease(URE)of the soil surrounding the roots of two alfalfa cultivars were significantly increased,while soil total nitrogen(TN),total phosphorus(TP),organic carbon(SOC),andα-glucosidase activity(AGC)were significantly decreased under saline-alkaline stress.There was no significant difference in root biomass and root morphological parameters of saline-alkaline tolerant cultivar GN under saline-alkaline stress.The number of root tips(RT),root surface area(RS)and root volume(RV)of AG were reduced by 61.16%,44.54%,and 45.31%,respectively,compared with control group.The ratios of K^(+)/Na^(+),Ca^(2+)/Na^(+)and Mg^(2+)/Na^(+)of GN were significantly higher than those of AG(p<0.05).The root fresh weight(RFW)and dry weight(RDW),root length(RL),RV and RT of alfalfa were positively regulated by soil SOC and TN,but negatively regulated by soil pH,EC,and URE(p<0.01).Root Ca^(2+)/Na+ratio was significantly positively correlated with soil TN,TP and SOC(p<0.01).The absorption of Mg and Ca ions in roots is significantly negatively regulated by soilβ-glucosidase activity(BGC)and acid phosphatase activity(APC)(p<

关键词： Saline-alkaline stress alfalfa root traits soil environmental factors correlation analysis