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Unraveling transition-metal-mediated stability of spinel oxide via in situ neutron scattering

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Journal of Energy Chemistry 2022年第5期31卷 60-70页

作者： Yan chen ke An Neutron Scattering Division Oak Ridge National LaboratoryOak RidgeTN 37831USA

The energy materials performance is intrinsically determined by structures from the average lattice structure to the atom arrangement, valence, and distribution of the containing transition metal(TM) elements. Understanding the mechanism of the structure transition and atom rearrangement via synthesis or processing is key to expediting the exploration of excellent energy materials. In this work, in situ neutron scattering is employed to reveal the real-time structure evolution, including the TM-O bonds, lattice,TM valence and the migration of the high-voltage spinel cathode LiNi_(0.5)Mn_(1.5)O_(4). The transition-metalmediated spinel destabilization under the annealing at the oxygen-deficient atmosphere is pinpointed.The formation of Mn^(3+) is correlated to the TM migration activation, TM disordered rearrangement in the spinel, and the transition to a layered-rocksalt phase. The further TM interdiffusion and Mn^(3+) reduction are also revealed with multi-stage thermodynamics and kinetics. The mechanisms of phase transition and atom migrations as functions of temperature, time and atmosphere present important guidance on the synthesis in various-valence element containing oxides.

关键词： In situ neutron diffraction Pair distribution function Energy storage material Material synthesis High-temperature phase transition Disordering Atomic interdiffusion

Exercise-induced adaptation of neurons in the vertebrate locomotor system

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Journal of Sport and Health Science 2024年第2期13卷 160-171页

作者： Yue Dai Yi cheng Renkai Ge Ke Chen Liming Yang key Lab of Adolescent Health Assessment and Exercise Intervention of Ministry of Education College of Physical Education and Health CareEast China Normal UniversityShanghai 200241China Shanghai key Laboratory of Multidimensional Information Processing School of Communication and Electronic EngineeringEast China Normal UniversityShanghai 200241China School of Physical Education and Health Care East China Jiaotong UniversityNanchang 330013China key Laboratory of High Confidence Software Technologies of Ministry of Education School of Computer SciencePeking UniversityBeijing 100871China

Vertebrate neurons are highly dynamic cells that undergo several alterations in their functioning and physiologies in adaptation to various external stimuli.In particular,how these neurons respond to physical exercise has long been an area of active research.Studies of the vertebrate locomotor system’s adaptability suggest multiple mechanisms are involved in the regulation of neuronal activity and properties during exercise.In this brief review,we highlight recent results and insights from the field with a focus on the following mechanisms:(a)alterations in neuronal excitability during acute exercise;(b)alterations in neuronal excitability after chronic exercise;(c)exercise-induced changes in neuronal membrane properties via modulation of ion channel activity;(d)exercise-enhanced dendritic plasticity;and(e)exercise-induced alterations in neuronal gene expression and protein synthesis.Our hope is to update the community with a cellular and molecular understanding of the recent mechanisms underlying the adaptability of the vertebrate locomotor system in response to both acute and chronic physical exercise.

关键词： Dendritic plasticity Excitability Exercise Ion channel modulation Neuron adaptation

Targeted mechanical forces enhance the effects of tumor immunotherapy by regulating immune cells in the tumor microenvironment

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Cancer Biology & Medicine 2023年第1期20卷 44-55页

作者： Pengfei Zhu Hongrui Lu Mingxing Wang Ke Chen Zheling chen Liu Yang Cancer Center Department of Medical OncologyZhejiang Provincial People's Hospital(Affiliated People's HospitalHangzhoul Medical College)Hangzhou 310014China Graduate School of Clinical Medicine Bengbu Medical CollegeBengbu 233000China Department of Gastroenterology&Pancreatic Surgery Zhejiang Provincial People's HospitalHangzhou 310014China

Mechanical forces in the tumor microenvironment(TME)are associated with tumor growth,proliferation,and drug resistance.Strong mechanical forces in tumors alter the metabolism and behavior of cancer cells,thus promoting tumor progression and metastasis.Mechanical signals are transformed into biochemical signals,which activate tumorigenic signaling pathways through mechanical transduction.Cancer immunotherapy has recently made exciting progress,ushering in a new era of“chemo-free”treatments.However,immunotherapy has not achieved satisfactory results in a variety of tumors,because of the complex tumor microenvironment.Herein,we discuss the effects of mechanical forces on the tumor immune microenvironment and highlight emerging therapeutic strategies for targeting mechanical forces in immunotherapy.

关键词： Mechanical force microenvironment immunotherapy extracellular matrix cancer

Konjac glucomannan enhances 5-FU-induced cytotoxicity of hepatocellular carcinoma cells via TLR4/PERK/CHOP signaling to induce endoplasmic reticulum stress

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Oncology Research 2022年第4期30卷 201-210页

作者： YONGKANG SHI JUN MA Ke Chen BIN chen Department of General Surgery Cancer CenterDivision of Gastrointestinal and Pancreatic SurgeryZhejiang Provincial People’s HospitalAffiliated People’s HospitalHangzhou Medical CollegeHangzhou310011China

5-Fluorouracil(5-FU)is a commonly used chemotherapeutic agent for various cancers.However,the drug resistance developed by tumor cells hinders the therapeutic effect.Konjac glucomannan(KGM)is indicated to sensitize 5-FU-resistant hepatocellular carcinoma(HCC)cells to 5-FU.In our study,we found that KGM or 5-FU treatment alone did not affect the malignant cell behaviors and endoplasmic reticulum(ER)stress of 5-FU-resistant HCC cells or HepG2/5-FU and Bel-7402/5-FU cells,while cotreatment with KGM and 5-FU significantly facilitated HCC cell apoptosis and ER stress and suppressed cell proliferation potential and migration abilities.Moreover,we explored the underlying mechanism by which KGM induces 5-FU cytotoxicity in HCC cells.We found that Toll-like receptor 4(TLR4)was downregulated in KGM-and 5-FU-treated HCC cells.TLR4 overexpression reversed the KGM and 5-FU cotreatment-induced inhibition of the malignant behaviors of 5-FU-resistant HCC cells.Furthermore,KGM enhanced 5-FU-induced ER stress by inhibiting TLR4 to activate PERK/ATF4/CHOP signaling.Xenograft mouse models were established using HepG2/5-FU cells,and KGM was demonstrated to reverse 5-FU resistance in HCC tumors in vivo by suppressing TLR4 to enhance ER stress and activate PERK/ATF4/CHOP signaling.In conclusion,KGM combined with 5-FU treatment significantly promoted apoptosis and reduced cell proliferation,migration and ER stress in 5-FU-resistant HCC cells compared with KGM or 5-FU treatment alone by downregulating TLR4 to activate PERK/ATF4/CHOP signaling.

关键词： Konjac glucomannan 5-FU Hepatocellular carcinoma Drug resistance

Uncertainty-aware complementary label queries for active learning

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Frontiers of Information Technology & Electronic Engineering 2023年第10期24卷 1497-1503页

作者： Shengyuan LIU Ke Chen Tianlei HU Yunqing MAO key Lab of Intelligent Computing Based Big Data of Zhejiang Province Zhejiang UniversityHangzhou 310027China State key Laboratory of Blockchain and Data Security Zhejiang UniversityHangzhou 310027China City Cloud Technology(China)Co. Ltd.Hangzhou 310000China

Many active learning methods assume that a learner can simply ask for the full annotations of some training data from annotators.These methods mainly try to cut the annotation costs by minimizing the number of annotation actions.Unfortunately,annotating instances exactly in many realworld classification tasks is still expensive.To reduce the cost of a single annotation action,we try to tackle a novel active learning setting,named active learning with complementary labels(ALCL).ALCL learners ask only yes/no questions in some classes.After receiving answers from annotators,ALCL learners obtain a few supervised instances and more training instances with complementary labels,which specify only one of the classes to which the pattern does not belong.There are two challenging issues in ALCL:one is how to sample instances to be queried,and the other is how to learn from these complementary labels and ordinary accurate labels.For the first issue,we propose an uncertainty-based sampling strategy under this novel setup.

关键词： complementary instance ordinary

Inhibition of Abnormal Grain Growth in Stir Zone via In‑Situ Intermetallic Particle Formation During Friction Stir Welding of AA6061

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Acta Metallurgica Sinica(English Letters) 2023年第4期36卷 597-610页

作者： Xin Zou Cunli Liu Muyang Deng Ji chen Lanting Zhang Ke Chen School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Shanghai key Laboratory of Material Laser Processing and Modification Shanghai Jiao Tong UniversityShanghai 200240China Shanghai-FANUC Robotics CO. LTDShanghai 201906China

Abnormal grain growth(AGG)has been widely observed in many friction stir welded(FSWed)joints during post-weld heat treatment(PWHT).The coarse grain structure not only reduces the strength of the joint but also limits its usage in superplastic forming.Several methods have been reported in previous studies to inhibit AGG,but all of them can only mitigate AGG.Complete inhibition of AGG was not achieved.In the current research,AGG was widely observed during the PWHT of friction stir welded AA6061.Multi-pass FSW enhanced the thermal stability of the as-welded grain structure but did not eliminate the occurrence of AGG.A new welding method was developed with the ball-milled Al–Ti powder mixture introduced into the stir zone and proved effective in inhibiting AGG in FSWed AA6061 during PWHT.The adoption of 5-pass FSW with an alternate rotation mode succeeded in producing an AGG-free sample.Microscopic characterizations conducted in the stir zone showed an evolution of Al–Ti powder mixture into different particle formations and Al3Ti new phase.Quantitative analysis of the second phase particles(SPPs)in the stir zone confirmed the increases in both particle number and average size.The quantitative results fit well with Humphreys’grain growth model,which theoretically explains the mechanism for AGG inhibition,i.e.,the significantly enhanced particle pinning effect.

关键词： Abnormal grain growth Friction stir welding AA6061 Second phase particle Particle pinning

Smart Contract Vulnerability Detection Method Based on Feature Graph and Multiple Attention Mechanisms

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Computers, Materials & Continua 2024年第5期79卷 3023-3045页

作者： Zhenxiang He Zhenyu Zhao Ke Chen Yanlin Liu School of Cyber Security Gansu University of Political Science and LawLanzhou730070China

The fast-paced development of blockchain technology is evident.Yet,the security concerns of smart contracts represent a significant challenge to the stability and dependability of the entire blockchain ecosystem.Conventional smart contract vulnerability detection primarily relies on static analysis tools,which are less efficient and accurate.Although deep learning methods have improved detection efficiency,they are unable to fully utilize the static relationships within contracts.Therefore,we have adopted the advantages of the above two methods,combining feature extraction mode of tools with deep learning techniques.Firstly,we have constructed corresponding feature extraction mode for different vulnerabilities,which are used to extract feature graphs from the source code of smart contracts.Then,the node features in feature graphs are fed into a graph convolutional neural network for training,and the edge features are processed using a method that combines attentionmechanismwith gated units.Ultimately,the revised node features and edge features are concatenated through amulti-head attentionmechanism.The result of the splicing is a global representation of the entire feature graph.Our method was tested on three types of data:Timestamp vulnerabilities,reentrancy vulnerabilities,and access control vulnerabilities,where the F1 score of our method reaches 84.63%,92.55%,and 61.36%.The results indicate that our method surpasses most others in detecting smart contract vulnerabilities.

关键词： Blockchain smart contracts deep learning graph neural networks

Effective and selective adsorption of uranyl ions by porous polyethylenimine-functionalized carboxylated chitosan/oxidized activated charcoal composite

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Frontiers of Chemical Science and Engineering 2022年第3期16卷 408-419页

作者： Juan Shen Fang Cao Siqi Liu Congjun Wang Rigui chen Ke Chen School of Materials Science and Engineering Southwest University of Science and TechnologyMianyang621010China State key Laboratory of Environmental-friendly Energy Materials Southwest University of Science and TechnologyMianyang621010China

Composite materials have elicited much interest because of their superior performance in the removal of toxic and radioactive uranyl ions from aqueous solutions.With polyethyleneimine as a functional group,carboxylated chitosan as a matrix,and oxidizing activated carbon as a nanofiller,this study synthesized a novel environment-friendly polyethylenimine-functionalized carboxylated chitosan/oxidized activated charcoal(PCO)biocomposite with a unique three-dimensional porous structure.PCO was synthesized through an easy chemical cross-linking method.Detailed characterization certified the formation of the unique three-dimensional porous structure.The obtained PCO was used to remove uranyl ions from an aqueous solution,demonstrating the maximum adsorption capacity of 450 mg·g^(−1).The adsorption capacity of PCO decreased by less than 7.51%after five adsorption-desorption cycles.PCO exhibited good adsorption selectivity(K_(d)=3.45×10^(4) mL·g^(−1))for uranyl ions.The adsorption mechanism of PCO was also discussed.The material showed good potential for application in the treatment of wastewater containing uranyl ions.

关键词： polyethylenimine carboxylated chitosan activated charcoal uranyl ion adsorption

Unique Continuation on Quadratic Curves for Harmonic Functions

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Chinese Annals of Mathematics,Series B 2022年第1期43卷 17-32页

作者： Yufei ke Yu chen School of Mathematics Shanghai University of Finance and EconomicsShanghai 200433China

The unique continuation on quadratic curves for harmonic functions is dis-cussed in this paper.By using complex extension method,the conditional stability of unique continuation along quadratic curves for harmonic functions is illustrated.The nu-merical algorithm is provided based on collocation method and Tikhonov regularization.The stability estimates on parabolic and hyperbolic curves for harmonic functions are demonstrated by numerical examples respectively.

关键词： Unique continuation Quadratic curves Harmonic function