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A short review of antibacterial Cu-bearing stainless steel:antibacterial mechanisms,corrosion resistance,and novel preparation techniques

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Journal of Iron and Steel Research(International) 2024年第1期31卷 24-45页

作者： shuai liu Han-jie Guo School of Artificial Intelligence Beijing Technology and Business UniversityBeijing100048China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials University of Science and Technology BeijingBeijing100083China

Cu-bearing stainless steel is widely used in the fields of food,medical and household sanitary equipment because of its surface finish and corrosion resistance.However,the growth of bacteria on stainless steel leads to the formation of biofilms,which causes corrosion.Therefore,the antibacterial property of stainless steel is a worthy research topic.Reviews of breakthroughs in the field of corrosion resistance and antimicrobial properties are still lacking.Herein,due to the scarcity of publications on the antibacterial mechanisms and processing methods of antibacterial Cu-bearing stainless steel,we review the current state of relevant research and progress.The toxicity of Cu,corrosion resistance mechanism of stainless steel,and antibacterial mechanism and preparation method of antibacterial stainless steel are reported.In addition,alloying,surface modification and other methods are found to have limitations in balancing the toxicity and antibacterial properties of copper and the relationship between the antibacterial properties and corrosion resistance of Cu-bearing stainless steel.A new preparation method of antibacterial stainless steel associated with selective laser melting(SLM)is proposed.SLM is becoming a powerful additive manufacturing technology that can be used to manufacture customized and complex metals.The research status of SLM applied in antibacterial stainless steel preparation is described.Finally,the future research direction of Cu-bearing antibacterial stainless steel is discussed.

关键词： Cu-bearing stainless steel Antibacterial Processing Additive manufacturing Corrosion resistance

Event-triggered distributed optimization for model-free multi-agent systems

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Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 214-224页

作者： Shanshan ZHENG shuai liu Licheng WANG College of Science University of Shanghai for Science and TechnologyShanghai200093China College of Automation Engineering Shanghai University of Electric PowerShanghai200090China

In this paper,the distributed optimization problem is investigated for a class of general nonlinear model-free multi-agent systems.The dynamical model of each agent is unknown and only the input/output data are available.A model-free adaptive control method is employed,by which the original unknown nonlinear system is equivalently converted into a dynamic linearized model.An event-triggered consensus scheme is developed to guarantee that the consensus error of the outputs of all agents is convergent.Then,by means of the distributed gradient descent method,a novel event-triggered model-free adaptive distributed optimization algorithm is put forward.Sufficient conditions are established to ensure the consensus and optimality of the addressed system.Finally,simulation results are provided to validate the effectiveness of the proposed approach.

关键词： Distributed optimization Multi-agent systems Model-free adaptive control Event-triggered mechanism

Neuronal conversion from glia to replenish the lost neurons

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Neural Regeneration Research 2024年第7期19卷 1446-1453页

作者： Shiyu Liang Jing Zhou Xiaolin Yu shuai Lu Ruitian liu National Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijingChina School of Chemical Engineering University of Chinese Academy of SciencesBeijingChina Department of Geriatric Rehabilitation Beijing Rehabilitation HospitalCapital Medical UniversityBeijingChina

Neuronal injury,aging,and cerebrovascular and neurodegenerative diseases such as cerebral infarction,Alzheimer’s disease,Parkinson’s disease,frontotemporal dementia,amyotrophic lateral sclerosis,and Huntington’s disease are characte rized by significant neuronal loss.Unfo rtunately,the neurons of most mammals including humans do not possess the ability to self-regenerate.Replenishment of lost neurons becomes an appealing therapeutic strategy to reve rse the disease phenotype.Transplantation of pluripotent neural stem cells can supplement the missing neurons in the brain,but it carries the risk of causing gene mutation,tumorigenesis,severe inflammation,and obstructive hydrocephalus induced by brain edema.Conversion of neural or non-neural lineage cells into functional neurons is a promising strategy for the diseases involving neuron loss,which may overcome the above-mentioned disadvantages of neural stem cell therapy.Thus far,many strategies to transfo rm astrocytes,fibroblasts,microglia,Muller glia,NG2 cells,and other glial cells to mature and functional neurons,or for the conversion between neuronal subtypes have been developed thro ugh the regulation of transcription factors,polypyrimidine tra ct binding protein 1(PTBP1),and small chemical molecules or are based on a combination of several factors and the location in the central nervous system.However,some recent papers did not obtain expected results,and discrepancies exist.Therefore,in this review,we discuss the history of neuronal transdifferentiation,summarize the strategies for neuronal replenishment and conversion from glia,especially astrocytes,and point out that biosafety,new strategies,and the accurate origin of the truly co nverted neurons in vivo should be focused upon in future studies.It also arises the attention of replenishing the lost neurons from glia by gene therapies such as up-regulation of some transc ription factors or downregulation of PTBP1 or drug interfe rence therapies.

关键词： astrocytes neural stem cells neurodegenerative diseases neuron polypyrimidine tract binding protein 1 repair reprogramming small molecule transcription factor transdifferentiation

BCCLR:A Skeleton-Based Action Recognition with Graph Convolutional Network Combining Behavior Dependence and Context Clues

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Computers, Materials & Continua 2024年第3期78卷 4489-4507页

作者： Yunhe Wang Yuxin Xia shuai liu College of Information Science and Engineering Institute of Interdisciplinary StudiesHunan Normal UniversityChangsha410081China School of Educational Sciences Institute of Interdisciplinary StudiesHunan Normal UniversityChangsha410081China

In recent years,skeleton-based action recognition has made great achievements in Computer Vision.A graph convolutional network(GCN)is effective for action recognition,modelling the human skeleton as a spatio-temporal graph.Most GCNs define the graph topology by physical relations of the human joints.However,this predefined graph ignores the spatial relationship between non-adjacent joint pairs in special actions and the behavior dependence between joint pairs,resulting in a low recognition rate for specific actions with implicit correlation between joint pairs.In addition,existing methods ignore the trend correlation between adjacent frames within an action and context clues,leading to erroneous action recognition with similar poses.Therefore,this study proposes a learnable GCN based on behavior dependence,which considers implicit joint correlation by constructing a dynamic learnable graph with extraction of specific behavior dependence of joint pairs.By using the weight relationship between the joint pairs,an adaptive model is constructed.It also designs a self-attention module to obtain their inter-frame topological relationship for exploring the context of actions.Combining the shared topology and the multi-head self-attention map,the module obtains the context-based clue topology to update the dynamic graph convolution,achieving accurate recognition of different actions with similar poses.Detailed experiments on public datasets demonstrate that the proposed method achieves better results and realizes higher quality representation of actions under various evaluation protocols compared to state-of-the-art methods.

关键词： Action recognition deep learning GCN behavior dependence context clue self-attention

Thymoquinone affects hypoxia-inducible factor-1αexpression in pancreatic cancer cells via HSP90 and PI3K/AKT/mTOR pathways

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World Journal of Gastroenterology 2024年第21期30卷 2793-2816页

作者： Zhan-Xue Zhao shuai Li Lin-Xun liu Department of General Surgery Qinghai Provincial People's HospitalXining 810007Qinghai ProvinceChina Department of Clinical Pharmacy The Affiliated Hospital of Qinghai UniversityXining 810001Qinghai ProvinceChina

BACKGROUND Pancreatic cancer(PC)is associated with some of the worst prognoses of all major cancers.Thymoquinone(TQ)has a long history in traditional medical practice and is known for its anti-cancer,anti-inflammatory,anti-fibrosis and antioxidant pharmacological activities.Recent studies on hypoxia-inducible factor-1α(HIF-1α)and PC have shown that HIF-1αaffects the occurrence and development of PC in many aspects.In addition,TQ could inhibit the development of renal cancer by decreasing the expression of HIF-1α.Therefore,we speculate whether TQ affects HIF-1αexpression in PC cells and explore the mechanism.AIM To elucidate the effect of TQ in PC cells and the regulatory mechanism of HIF-1αexpression.METHODS Cell counting kit-8 assay,Transwell assay and flow cytometry were performed to detect the effects of TQ on the proliferative activity,migration and invasion ability and apoptosis of PANC-1 cells and normal pancreatic duct epithelial(hTERTHPNE)cells.Quantitative real-time polymerase chain reaction and western blot assay were performed to detect the expression of HIF-1αmRNA and protein in PC cells.The effects of TQ on the HIF-1αprotein initial expression pathway and ubiquitination degradation in PANC-1 cells were examined by western blot assay and co-immunoprecipitation.RESULTS TQ significantly inhibited proliferative activity,migration,and invasion ability and promoted apoptosis of PANC-1 cells;however,no significant effects on hTERT-HPNE cells were observed.TQ significantly reduced the mRNA and protein expression levels of HIF-1αin PANC-1,AsPC-1,and BxPC-3 cells.TQ significantly inhibited the expression of the HIF-1αinitial expression pathway(PI3K/AKT/mTOR)related proteins,and promoted the ubiquitination degradation of the HIF-1αprotein in PANC-1 cells.TQ had no effect on the hydroxylation and von Hippel Lindau protein mediated ubiquitination degradation of the HIF-1αprotein but affected the stability of the HIF-1αprotein by inhibiting the interaction between HIF-1αand HSP90,thus promoting its ubiquitination

关键词： Thymoquinone Pancreatic cancer Hypoxia-inducible factor-1α PI3K/AKT/mTOR HSP90

Incidence,prevalence,and causes of spinal injuries in China,1990-2019:Findings from the Global Burden of Disease Study 2019

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Chinese Medical Journal 2024年第6期137卷 704-710页

作者： Chenjun liu Tingling Xu Weiwei Xia shuai Xu Zhenqi Zhu Maigeng Zhou Haiying liu Department of Spinal Surgery Peking University People’s HospitalPeking UniversityBeijing 100044China Chinese Preventive Medicine Association Committee on Prevention and Control of Spinal DiseaseBeijing 100009China National Center for Chronic and Noncommunicable Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijing 100050China School of Public Health Xi’an Jiaotong UniversityXi’anShaanxi 710061China

Background:Spinal injuries are an urgent public health priority;nevertheless,no China-wide studies of these injuries exist.This study measured the incidence,prevalence,causes,regional distribution,and annual trends of spinal injuries in China from 1990 to 2019.Methods:We used data from the Global Burden of Diseases,Injuries,and Risk Factors Study 2019 to estimate the incidence and prevalence of spinal injuries in China.The data of 33 provincial-level administrative regions(excluding Taiwan,China)provided by the National Center for Chronic and Noncommunicable Disease Control and Prevention,Chinese Center for Disease Control and Prevention(CDC)were use to systematically analyze the provincial etiology,geographical distribution,and annual trends of spinal injuries.The Bayesian meta-regression tool DisMod-MR 2.1 was used to ensure the consistency among incidence,prevalence,and mortality rates in each case.Results:From 1990 to 2019,the number of living patients with spinal injuries in China increased by 138.32%,from 2.14 million to 5.10 million,while the corresponding age-standardized prevalence increased from 0.20%(95%uncertainty interval[UI]:0.18-0.21%)to 0.27%(95%UI:0.26-0.29%).The incidence of spinal injuries in China increased by 89.91%(95%UI:72.39-107.66%),and the prevalence increased by 98.20%(95%UI:89.56-106.82%),both the most significant increases among the G20 countries;71.00%of the increase could be explained by age-specific prevalence.In 2019,the incidence was 16.47(95%UI:12.08-22.00,per 100,000 population),and the prevalence was 358.30(95%UI:333.96-386.62,per 100,000 population).Based on the data of 33 provincial-level administrative regions provided by CDC,age-standardized incidence and prevalence were both highest in developed provinces in Eastern China.The primary causes were falls and road injuries;however,the prevalence and specific causes differed across provinces.Conclusions:In China,the overall disease burden of spinal injuries increased significantly during the past three decades but varied consi

关键词： Spinal injuries Global Burden of Diseases,Injuries and Risk Factors Study 2019 Incidence Prevalence Falls Road injuries

Photocatalytic transformation of selected biomass derivatives to value added chemicals and hydrogen fuel

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Chinese Chemical Letters 2024年第3期35卷 19-26页

作者： Xiangjun liu shuai Zhang Miao Wang Junqi Wang School of Human Settlements and Civil Engineering Xi'an Jiaotong UniversityXi'an 710049China

Biomass is the most bountiful renewable carbon resource on earth.Photocatalytic transformation is a promising method to utilize biomass to obtain high-value-added chemicals and it has more obvious advantages compared with thermochemical and biological processes due to the milder operational conditions,fewer reagents and equipment.Semiconductor material is one of the most common kinds of heterogeneous biomass photocatalysts,which has the advantages of high selectivity,stable catalytic performance,long activation time,and low cost.In this paper,the significant research progress on the photocatalytic transformation of biomass with semiconductor materials to produce high-value-added chemicals is reviewed,and the three most typical semiconductor photocatalysts(TiO_(2),Cd S,and g-C_(3)N_(4))are detailed.The photocatalytic mechanism and photocatalytic system optimization including structural modification,metal co-catalyst loading,and introduction of heterojunction are presented.Besides,the main problems,the development direction and trend of semiconductor materials in photocatalytic transformations of biomass in the future are prospected,which provide guidance and inspiration for the further development of semiconductor photocatalysts and make contributions to the progress in efficient utilization of biomass.

关键词： Photocatalytic transformation Biomass Semiconductor material H_(2) High value-added chemical

Ammonia storage and slip under steady and transient state in close-coupled SCR

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Journal of Environmental Sciences 2024年第4期138卷 470-481页

作者： Shiyu liu Zhaohuan Zhang Zexian Guo Boyuan Wang Buyu Wang Xiao Ma Shijin shuai State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China Institute for Aero Engine Tsinghua UniversityBeijing 100084China

The close-coupled selective catalytic reduction(cc-SCR)catalyst is an effective technology to reduce tailpipe NOx emission during cold start.This paper investigated the optimal ammonia storage under steady and transient state in the cc-SCR.The study showed that a trade-off between NOx conversion efficiency and ammonia slip is observed on the pareto solutions under steady state,and the optimal ammonia storage is calculated with ammonia slip less than 10μL/L based on the ChinaⅥemission legislation.The rapid temperature increase will lead to severe ammonia slip in the transient test cycle.A simplified 0-D calculation method on ammonia slip under transient state is proposed based on kinetic model of ammonia adsorption and desorption.In addition,the effect of ammonia storage,catalyst temperature and temperature increasing rate on ammonia slip are analyzed.The optimal ammonia storage is calculated with maximum ammonia slip less than 100μL/L according to the oxidation efficiency of ammonia slip catalyst(ASC)downstream cc-SCR.It was found that the optimal ammonia storage under transient state is much lower than that under steady state in cc-SCR at lower temperature,and a phase diagram is established to analyze the influence of temperature and temperature increasing rate on optimal ammonia storage.

关键词： Close-coupled SCR Ammonia storage and slip Steady and transient state Generic algorithm

Configuration and Kinematics of a 3-DOF Generalized Spherical Parallel Mechanism for Ankle Rehabilitation

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 176-188页

作者： Jianjun Zhang shuai Yang Chenglei liu Xiaohui Wang Shijie Guo School of Mechanical Engineering Hebei University of TechnologyTianjin 300401China Key Laboratory of Robot Perception and Human-Machine Fusion Tianjin 300401China

The kinematic equivalent model of an existing ankle-rehabilitation robot is inconsistent with the anatomical structure of the human ankle,which influences the rehabilitation effect.Therefore,this study equates the human ankle to the UR model and proposes a novel three degrees of freedom(3-DOF)generalized spherical parallel mechanism for ankle rehabilitation.The parallel mechanism has two spherical centers corresponding to the rotation centers of tibiotalar and subtalar joints.Using screw theory,the mobility of the parallel mechanism,which meets the requirements of the human ankle,is analyzed.The inverse kinematics are presented,and singularities are identified based on the Jacobian matrix.The workspaces of the parallel mechanism are obtained through the search method and compared with the motion range of the human ankle,which shows that the parallel mechanism can meet the motion demand of ankle rehabilitation.Additionally,based on the motion-force transmissibility,the performance atlases are plotted in the parameter optimal design space,and the optimum parameter is obtained according to the demands of practical applications.The results show that the parallel mechanism can meet the motion requirements of ankle rehabilitation and has excellent kinematic performance in its rehabilitation range,which provides a theoretical basis for the prototype design and experimental verification.

关键词： Ankle rehabilitation Parallel mechanism Kinematic analysis Parameter optimization