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Remediation of di(2-ethylhexyl)phthalate(DEHP)contaminated black soil by freeze-thaw aging biochar

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Journal of Environmental Sciences 2024年第1期135卷 681-692页

作者： Lei Wang Zeyu Dou Chaoran Ma xiaochen Jia Hongye Wang Wenjing Bao Lei Wang Jianhua Qu Ying zhang School of Resources and Environment Northeast Agricultural UniversityHarbin 150030China

Di(2-ethylhexyl)phthalate(DEHP),a complex structure with high toxicity,is a common organic pollutant.This study investigated the effects of fresh biochar(FBC),and freeze-thaw cycled aged biochar(FTC-BC)on DEHP-contaminated soils using a pot experiment.The specific surface area of FBC increased from 145.20 to 303.50 m~2/g,and oxygen-containing functional groups increased from 1.26 to 1.48 mol/g after freeze-thaw cycles,greatly enhancing the adsorption of DEHP by biochar in the soil.The comprehensive radar chart evaluation showed that FBC and FTC-BC reduced DEHP growth stress and improved the soil properties.Compared with FBC,FTC-BC performed better in protecting the normal growth of pakchoi and improving soil properties.In addition,the application of biochar increased the diversity and abundance of bacteria in the DEHP-contaminated soil and changed the composition of the soil bacterial community.The partial least squares path model(PLS-PM)showed that adding biochar as a soil remediation agent significantly positively impacted soil nutrients and indirectly reduced the DEHP levels in soil and plants by increasing soil microbial diversity.Compared with FBC,FTC-BC creates a more satisfactory living environment for microorganisms and has a better effect on the degradation of DEHP in the soil.This study provides a theoretical basis for future biochar remediation of DEHP-contaminated soils in cold high-latitude regions.

关键词： DEHP Freeze-thaw cycles Biochar Soil restoration

Secure resource allocation against colluding eavesdropping in a user-centric cell-free massive multiple-input multiple-output system

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 500-512页

作者： Na LI Yuanyuan GAO Kui XU xiaochen XIA Huazhi HU Yang LI Yueyue zhang College of Communication Engineering Army Engineering University of PLANanjing 210007China

We investigate the resource allocation problem of a cell-free massive multiple-input multiple-output system under the condition of colluding eavesdropping by multiple passive eavesdroppers.To address the problem of limited pilot resources,a scheme is proposed to allocate the pilot with the minimum pollution to users based on access point selection and optimize the pilot transmission power to improve the accuracy of channel estimation.Aiming at the secure transmission problem under a colluding eavesdropping environment by multiple passive eavesdroppers,based on the local partial zero-forcing precoding scheme,a transmission power optimization scheme is formulated to maximize the system’s minimum security spectral efficiency.Simulation results show that the proposed scheme can effectively reduce channel estimation error and improve system security.

关键词： Cell-free Colluding eavesdropping Limited pilot resources Access point selection Security rate

Oncogenic β-catenin-driven liver cancer is susceptible to methotrexate-mediated disruption of nucleotide synthesis

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Chinese Medical Journal 2024年第2期137卷 181-189页

作者： Fangming Liu Yuting Wu Baohui zhang Shuhui Yang Kezhuo Shang Jie Li Pengju zhang Weiwei Deng Linlin Chen Liang Zheng xiaochen Gai Hongbing zhang Department of Physiology State Key Laboratory of Common Mechanism Research for Major DiseasesHaihe Laboratory of Cell EcosystemInstitute of Basic Medical Sciences and School of Basic MedicineChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100005China Department of Physiology Institute of Basic Medical Sciences and School of Basic MedicineGraduate School of Peking Union Medical CollegeChinese Academy of Medical SciencesBeijing100005China Department of Physiology School of Life ScienceChina Medical UniversityShenyangLiaoning 110122China School of Life Sciences Westlake UniversityHangzhouZhejiang 310024China Key Laboratory of Pediatric Hematology and Oncology Ministry of HealthInstitute of Pediatric Translational MedicineShanghai Children’s Medical CenterShanghai Jiao Tong School of MedicineShanghai 200127China

Background:Liver cancer is largely resistant to chemotherapy.This study aimed to identify the effective chemotherapeutics forβ-catenin-activated liver cancer which is caused by gain-of-function mutation of catenin beta 1(CTNNB1),the most frequently altered proto-oncogene in hepatic neoplasms.Methods:Constitutiveβ-catenin-activated mouse embryonic fibroblasts(MEFs)were established by deleting exon 3(β-catenin^(Δ(ex3)/+)),the most common mutation site in CTNNB1 gene.A screening of 12 widely used chemotherapy drugs was conducted for the ones that selectively inhibitedβ-catenin^(Δ(ex3)/+)but not for wild-type MEFs.Untargeted metabolomics was carried out to examine the alterations of metabolites in nucleotide synthesis.The efficacy and selectivity of methotrexate(MTX)onβ-catenin-activated human liver cancer cells were determined in vitro.Immuno-deficient nude mice subcutaneously inoculated withβ-catenin wild-type or mutant liver cancer cells and hepatitis B virus(HBV);β-catenin^(lox(ex3)/+)mice were used,respectively,to evaluate the efficacy of MTX in the treatment ofβ-catenin mutant liver cancer.Results:MTX was identified and validated as a preferential agent against the proliferation and tumor formation ofβ-catenin-activated cells.Boosted nucleotide synthesis was the major metabolic aberration inβ-catenin-active cells,and this alteration was also the target of MTX.Moreover,MTX abrogated hepatocarcinogenesis of HBV;β-catenin^(lox(ex3)/+)mice,which stimulated concurrent Ctnnb1-activated mutation and HBV infection in liver cancer.Conclusion:MTX is a promising chemotherapeutic agent forβ-catenin hyperactive liver cancer.Since repurposing MTX has the advantages of lower risk,shorter timelines,and less investment in drug discovery and development,a clinical trial is warranted to test its efficacy in the treatment ofβ-catenin mutant liver cancer.

关键词： Liver cancer β-catenin Methotrexate Nucleotide synthesis Chemotherapy

Recent progress in functional metal-organic frameworks for bio-medical application

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Regenerative Biomaterials 2024年第2期3卷 37-54页

作者： Wenwen Chai xiaochen Chen Jing Liu Liyan zhang Chunyu Liu Li Li John Robert Honiball Haobo Pan Xu Cui Deping Wang School of Materials Science and Engineering Tongji UniversityShanghai 201804China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China Department of Orthopaedics&Traumatology School of Clinical MedicineLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongChina

Metal-organic frameworks(MOFs)have a high specific surface area,adjustable pores and can be used to obtain functional porous materials with diverse and well-ordered structures through coordination and self-assembly,which has intrigued wide interest in a broad range of disciplines.In the arena of biomedical engineering,the functionalized modification of MOFs has produced drug carriers with excellent dispersion and functionalities such as target delivery and response release,with promising applications in bio-detection,disease therapy,tissue healing,and other areas.This review summa-rizes the present state of research on the functionalization of MOFs by physical binding or chemical cross-linking of small molecules.***.bioma romolecules.and hvdrogels and evaluates the role and approach of MOFs functionalization in boosting the reactivity of materials.On this basis,research on the application of functionalized MOFs composites in biomedical engineering fields such as drug delivery,tissue repair,disease treatment,bio-detection and imaging is surveyed,and the development trend and application prospects of functionalized MOFs as an important new class of biomedical materials in the biomedical field are anticipated,which may provide some inspiration and reference for further development of MOF for bio-medical applications.

关键词： metal-organic frameworks porous functionalization tissue repair disease treatment

Joint UAV trajectory and communication design with heterogeneous multi-agent reinforcement learning

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Science China(Information Sciences) 2024年第3期67卷 225-245页

作者： Xuanhan ZHOU Jun XIONG Haitao ZHAO Xiaoran LIU Baoquan REN xiaochen zhang Jibo WEI Hao YIN College of Electronic Science and Technology National University of Defense Technology Systems Engineering Institute Academy of Military Sciences PLA

Unmanned aerial vehicles(UAVs) are recognized as effective means for delivering emergency communication services when terrestrial infrastructures are unavailable. This paper investigates a multiUAV-assisted communication system, where we jointly optimize UAVs’ trajectories, user association, and ground users(GUs)’ transmit power to maximize a defined fairness-weighted throughput metric. Owing to the dynamic nature of UAVs, this problem has to be solved in real time. However, the problem’s non-convex and combinatorial attributes pose challenges for conventional optimization-based algorithms, particularly in scenarios without central controllers. To address this issue, we propose a multi-agent deep reinforcement learning(MADRL) approach to provide distributed and online solutions. In contrast to previous MADRLbased methods considering only UAV agents, we model UAVs and GUs as heterogeneous agents sharing a common objective. Specifically, UAVs are tasked with optimizing their trajectories, while GUs are responsible for selecting a UAV for association and determining a transmit power level. To learn policies for these heterogeneous agents, we design a heterogeneous coordinated QMIX(HC-QMIX) algorithm to train local Q-networks in a centralized manner. With these well-trained local Q-networks, UAVs and GUs can make individual decisions based on their local observations. Extensive simulation results demonstrate that the proposed algorithm outperforms state-of-the-art benchmarks in terms of total throughput and system fairness.

关键词： unmanned aerial vehicle (UAV) trajectory design resource allocation multi-agent deep reinforcement learning (MADRL) heterogeneous agents

Synergy of phosphorus vacancies and build-in electric field into NiCo/NiCoP Mott-Schottky integrated electrode for enhanced water splitting performance

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Chinese Chemical Letters 2024年第2期35卷 604-610页

作者： xiaochen zhang Hui Xue Jing Sun Niankun Guo Tianshan Song Jiawen Sun Yi-Ru Hao Qin Wang College of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhot 010021China

Vacancy engineering and Mott-Schottky heterostructure can accelerate charge transfer,regulate adsorption energy of reaction intermediates,and provide additional active sites,which are regarded as valid means for improving catalytic activity.However,the underlying mechanism of synergistic regulation of interfacial charge transfer and optimization of electrocatalytic activity by combining vacancy and Mott-Schottky junction remains unclear.Herein,the growth of a bifunctional NiCo/NiCoP Mott-Schottky electrode with abundant phosphorus vacancies on foam nickel(NF)has been synthesized through continuous phosphating and reduction processes.The obtained NiCo/NiCoP heterojunctions show remarkable OER and HER activities,and the overpotentials for OER and HER are as low as 117 and 60 mV at 10 mA/cm^(2) in 1 mol/L KOH,respectively.Moreover,as both the cathode and anode of overall water splitting,the voltage of the bifunctional NiCo/NiCoP electrocatalyst is 1.44 V at 10 mA/cm^(2),which are far exceeding the benchmark commercial electrodes.DFT theoretical calculation results confirm that the phosphorus vacancies and build-in electric field can effectively accelerate ion and electron transfer between NiCo alloy and NiCoP semiconductor,tailor the electronic structure of the metal centers and lower the Gibbs free energy of the intermediates.Furthermore,the unique self-supported integrated structure is beneficial to facilitate the exposure of the active site,avoid catalyst shedding,thus improving the activity and structural stability of NiCo/NiCoP.This study provides an avenue for the controllable synthesis and performance optimization of Mott-Schottky electrocatalysts.

关键词： Mott-Schottky Build-in electric field Phosphorus vacancies Phosphides Overall water splitting

Refractive index sensing based on a twisted nano-kirigami metasurface

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Photonics Research 2024年第2期12卷 218-225页

作者： SHUQI QIAO xiaochen zhang QINGHUA LIANG YANG WANG CHANG-YIN JI XIAOWEI LI LAN JIANG SHUAI FENG HONGLIAN GUO JIAFANG LI School of Science Minzu University of ChinaBeijing 100081China Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(Ministry of Education) Beijing Key Laboratory of Nanophotonics&Ultrafine Optoelectronic Systemsand School of PhysicsBeijing Institute of TechnologyBeijing 100081China Laser Micro/Nano Fabrication Laboratory School of Mechanical EngineeringBeijing Institute of TechnologyBeijing 100081China

Plasmonic sensing technology has attracted considerable attention for high sensitivity due to the ability to effectively localize and manipulate light.In this study,we demonstrate a refractive index(RI)sensing scheme based on open-loop twisted meta-molecule arrays using the versatile nano-kirigami principle.RI sensing has the features of a small footprint,flexible control,and simple preparation.By engineering the morphology of meta-molecules or the RI of the ambient medium,the chiral surface lattice resonances can be significantly enhanced,and the wavelength,intensity,and sign of circular dichroism(CD)can be flexibly tailored.Utilizing the relation between the wavelength of the CD peak and the RI of the superstrate,the RI sensor achieves a sensitivity of 1133 nm/RIU.Additionally,we analyze these chiroptical responses by performing electromagnetic multipolar decomposition and electric field distributions.Our study may serve as an ideal platform for applications of RI measurement and provide new insights into the manipulation of chiral light–matter interactions.

关键词： twisted chiral index

A high-sensitive and self-selective humanoid mechanoreceptor for spatiotemporal tactile stimuli cognition

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Nano Research 2024年第5期17卷 4400-4409页

作者： Shuxin Bi Xuan Zhao Fangfang Gao xiaochen Xun Bin Zhao Liangxu Xu Tian Ouyang Qingliang Liao Yue zhang Academy for Advanced Interdisciplinary Science and Technology Beijing Advanced Innovation Center for Materials Genome EngineeringUniversity of Science and Technology(Beijing)Beijing 100083China Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of EducationBeijing Key Laboratory for Advanced Energy Materials and TechnologiesSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

The cognition of spatiotemporal tactile stimuli,including fine spatial stimuli and static/dynamic temporal stimuli,is paramount for intelligent robots to feel their surroundings and complete manipulation tasks.However,current tactile sensors have restrictions on simultaneously demonstrating high sensitivity and performing selective responses to static/dynamic stimuli,making it a challenge to effectively cognize spatiotemporal tactile stimuli.Here,we report a high-sensitive and self-selective humanoid mechanoreceptor(HMR)that can precisely respond to spatiotemporal tactile stimuli.The HMR with PDMS/chitosan@CNTs(PDMS:polydimethylsiloxane;CNT:carbon nanotube)graded microstructures and polyurethane hierarchical porous spacer exhibits high sensitivity of 3790.8 kPa^(-1).The HMR demonstrates self-selective responses to static and dynamic stimuli with mono signal through the hybrid of piezoresistive and triboelectric mechanisms.Consequently,it can respond to spatiotemporal tactile stimuli and generate distinguishable and multi-type characteristic signals.With the assistance of the convolutional neural network,multiple target objects can be easily identified with a high accuracy of 99.1%.This work shows great potential in object precise identification and dexterous manipulation,which is the basis of intelligent robots and natural human-machine interactions.

关键词： mechanoreceptors self-selective high-sensitive spatiotemporal tactile stimuli cognition sensors

Tumor microenvironment-activated theranostic nanoreactor for NIR-II Photoacoustic imaging-guided tumor-specific photothermal therapy

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Fundamental Research 2024年第1期4卷 178-187页

作者： Nan Yang Hui Li Changyu Cao Lei Zhao Xuejiao Song Wenjun Wang Wenjing Xu Yewei zhang Peng Chen xiaochen Dong Key Laboratory of Flexible Electronics(KLOFE)and Institute of Advanced Materials(IAM) School of Physical and Mathematical SciencesNanjing Tech University(NanjingTech)Nanjing 211816China School of Physical Science and Information Technology Liaocheng UniversityLiaocheng 252059China Department of Hepatobiliary and Pancreatic Surgery the Second Affiliated Hospital of Nanjing Medical UniversityNanjing 210011China School of Chemical and Biomedical Engineering Lee Kong Chian School of MedicineNanyang Technological University62 Nanyang DriveSingapore 637459Singapore

Theranostic agents that can be sensitively and specifically activated by the tumor microenvironment(TME)have recently attracted considerable attention.In this study,TME-activatable 3,3′,5,5′-tetramethylbenzidine(TMB)-copper peroxide(CuO_(2))@poly(lactic-co-glycolic acid)(PLGA)@red blood cell membrane(RBCM)(TCPR)nanoparticles(NPs)for second near-infrared photoacoustic imaging-guided tumor-specific photothermal therapy were developed by co-loading CuO_(2)NPs and TMB into PLGA camouflaged by RBCMs.As an efficient H_(2)O_(2)supplier,once exposed to a proton-rich TME,CuO_(2)NPs can generate H_(2)O_(2)and Cu^(2+),which are further reduced to Cu^(+) by endogenous glutathione.Subsequently,the Cu^(+)-mediated Fenton-like reaction produces cytotoxic·OH to kill the cancer cells and induce TMB-mediated photoacoustic and photothermal effects.Combined with the RBCM modification-prolonged blood circulation,TCPR NPs display excellent specificity and efficiency in suppressing tumor growth,paving the way for more accurate,safe,and efficient cancer theranostics.

关键词： Nanoparticles Photoacoustic imaging Second near-infrared region Tumor microenvironment Self-sufficient H_(2)O_(2)