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Study on the thermally induced spindle angular errors of a five-axis CNC machine tool

Advances in Manufacturing 2023年第1期11卷 75-92页

作者： Ji Peng Ming Yin Li Cao luo-feng xie Xian-Jun Wang Guo-Fu Yin School of Mechanical Engineering Sichuan UniversityChengdu610065People’s Republic of China

Thermally induced spindle angular errors of a machine tool are important factors that affect the machining accuracy of parts.It is critical to develop models with good generalization abilities to control these angular thermal errors.However,the current studies mainly focus on the modeling of linear thermal errors,and an angular thermal error model applicable to different working conditions has rarely been investigated.Furthermore,the formation mechanism of the angular thermal error remains to be studied.In this study,an analytical modeling method was proposed by analyzing the formation and propagation chain of the spindle angular thermal errors of a five-axis computer numerical control(CNC)machine tool.The effects of the machine tool structure and position were considered in the modeling process.The angular thermal error equations were obtained by analyzing the spatial thermoelastic deformation states.An analytical model of the spindle angular thermal error was established based on the geometric relation between thermal deformations.The model parameters were identified using the trust region least squares method.The results showed that the proposed analytical model exhibited good generalization ability in predicting spindle pitch angular thermal errors under different working conditions with variable spindle rotational speeds,spindle positions,and environmental temperatures in different seasons.The average mean absolute error(MAE),root mean square error(RMSE)and R2 in twelve different experiments were 4.7μrad,5.6μrad and 0.95,respectively.This study provides an effective method for revealing the formation mechanism and controlling the spindle angular thermal errors of a CNC machine tool.

关键词： Machine tool Angular thermal errors Thermal error modeling Analytical model

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Turbulence Statistics of Thermo-Buoyancy Supercritical Fuel Flow in a Regenerative Cooling Channel

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Journal of Thermal Science 2024年第1期33卷 126-137页

作者： SUN feng xie Gongnan School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Department of Thermal Engineering Tsinghua UniversityBeijing 100084China

Active regenerative cooling with supercritical hydrocarbon fuel is considered as the most promising thermal protection method.The existence of buoyancy force would lead to strongly anisotropic flow and thermal transport characteristics.It is closely related to the cooling performance of the engine.To elucidate the mechanisms of turbulent transport,the large eddy simulation(LES) was performed to assess turbulence statistics within different turbulence scales.The results indicated that the buoyancy and inertial force together dominated the change of turbulent structure.Moreover,the spatial thermal buoyancy effect significantly suppressed the vertical velocity fluctuation.This is due to the laminar motion caused by the buoyancy force,thereby weakening the thermal transport.For the statistics of velocity fluctuation,it was found that the buoyancy force and inertial force greatly weaken the vertical and streamwise velocity fluctuation,respectively.For the statistics of thermal transport,the results pointed out that the near-wall heat transport characteristics need to be paid more attention.The thickness of the temperature mixing boundary layer led to the attenuation of vertical heat flux,which inhibited vertical temperature diffusion and predisposed to extreme conditions of heat transfer deterioration.The results can enhance the academic understanding of the heat transfer mechanism of supercritical fluids,and give guidance for further applications of thermal protection.

关键词： active regenerative cooling large eddy simulation(LES) buoyancy force turbulence statistics

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Clinical application of COVID-19 vaccine in liver transplant recipients

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Hepatobiliary & Pancreatic Diseases International 2024年第4期23卷 339-343页

作者： feng-Chao Liu Man xie Wei Rao Division of Hepatology Liver Disease CenterThe Affiliated Hospital of Qingdao UniversityQingdao 266000China Organ Transplantation Center The Affiliated Hospital of Qingdao UniversityQingdao 266000China Institute of Organ Donation and Transplantation of Qingdao University Qingdao 266000China Department of Gastroenterology The Affiliated Hospital of Qingdao UniversityQingdao 266000China

Background:Solid organ transplant(SOT)activities,such as liver transplant,have been greatly influenced by the pandemic of coronavirus disease 2019(COVID-19),a disease caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Immunosuppressed individuals of liver transplant recipients(LTRs)tend to have a high risk of COVID-19 infection and related complications.Therefore,COVID-19 vaccination has been recommended to be administered as early as possible in LTRs.Data sources:The keywords“liver transplant”,“SARS-CoV-2”,and“vaccine”were used to retrieve articles published in PubMed.Results:The antibody response following the 1st and 2nd doses of vaccination was disappointingly low,and the immune responses among LTRs remarkably improved after the 3rd or 4th dose of vaccination.Although the 3rd or 4th dose of COVID-19 vaccine increased the antibody titer,a proportion of patients remained unresponsive.Furthermore,recent studies showed that SARS-CoV-2 vaccine could trigger adverse events in LTRs,including allograft rejection and liver injury.Conclusions:This review provides the recently reported data on the antibody response of LTRs following various doses of vaccine,risk factors for poor serological response and adverse events after vaccination.

关键词： Liver transplant COVID-19 SARS-CoV-2 Vaccine Antibody response

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Striking a growth–defense balance:Stress regulators that function in maize development

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Journal of Integrative Plant Biology 2024年第3期66卷 424-442页

作者： Shiyi xie Hongbing luo Wei Huang Weiwei Jin Zhaobin Dong Maize Engineering and Technology Research Center of Hunan Province College of AgronomyHunan Agricultural UniversityChangsha 410128China State Key Laboratory of Maize Bio-breeding National Maize Improvement CenterFrontiers Science Center for Molecular Design BreedingChina Agricultural UniversityBeijing 100193China Tianjin Key Laboratory of Intelligent Breeding of Major Crops Fresh Corn Research Center of BTHCollege of Agronomy&Resources and EnvironmentTianjin Agricultural UniversityTianjin 300384China

Maize(Zea mays)cultivation is strongly affected by both abiotic and biotic stress,leading to reduced growth and productivity.It has recently become clear that regulators of plant stress responses,including the phytohormones abscisic acid(ABA),ethylene(ET),and jasmonic acid(JA),together with reactive oxygen species(ROS),shape plant growth and development.Beyond their well established functions in stress responses,these molecules play crucial roles in balancing growth and defense,which must be finely tuned to achieve high yields in crops while maintaining some level of defense.In this review,we provide an in-depth analysis of recent research on the developmental functions of stress regulators,focusing specifically on maize.By unraveling the contributions of these regulators to maize development,we present new avenues for enhancing maize cultivation and growth while highlighting the potential risks associated with manipulating stress regulators to enhance grain yields in the face of environmental challenges.

关键词： stress regulators maize development ABA ET JA ROS

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Experimental study on shock interaction control of double wedge in high-enthalpy hypersonic flow subject to plasma synthetic jet

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Chinese Journal of Aeronautics 2024年第4期37卷 151-165页

作者： Xuzhen xie Qiang LIU Yan ZHOU Zhenbing luo Wei xie Guanghui BAI Kai luo Qiu WANG Jianjun WU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China China Academy of Launch Vehicle Technology Beijing 100076China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China

The hypersonic shock-shock interaction flow field at double-wedge geometries controlled by plasma synthetic jet actuator is experimentally studied in a Ma = 8 high-enthalpy shock tunnel with the purpose of exploring a novel technique for reducing surface heat flux in a real flight environment. The results demonstrate that increasing the discharge energy is advantageous in eliminating the shock wave, shifting the shock wave interaction point, and shortening the control response time. The oblique shock wave can be completely removed when the actuator's discharge energy grows from 0.4 J to 11.5 J, and the displacement of the shock wave interaction point increases by 124.56%, while the controlled response time is shortened by 30 μs. Besides, the reduction in diameter of the jet exit is firstly proved to have a negative impact on energy deposition in a working environment with incoming flow, which reduces the discharge energy and hence decreases the control effect. The shock wave control response time lengthens when the jet exits away from the second wedge. Along with comparing the change in wall heat flux at the second wedge over time, the control effect of plasma synthetic jet actuator with and without inflation is also analyzed. When plasma synthetic jet works in inflatable mode, both the ability to eliminate shock waves and the shifting effect of the shock wave interaction point are increased significantly, and the wall heat flux is also reduced.

关键词： Hypersonic flow High-enthalpy flow Plasma synthetic jet Shock wave Flow control

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Unveiling the performance of a novel alkalizing bacterium Enterobacter sp.LYX-2 in immobilization of available Cd

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Journal of Environmental Sciences 2024年第3期137卷 245-257页

作者： Yixin luo Min Liao Xiongxiong Lu Na Xu Xiaomei xie Weiming Gao College of Environmental and Resource Science Zhejiang UniversityHangzhou 310058China Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment Hangzhou 310058China National Demonstration Center for Experimental Environmental and Resources Education Zhejiang UniversityHangzhou 310058China

A novel alkalizing strain Enterobacter sp.LYX-2 that could resist 400 mg/L Cd was isolated from Cd-contaminated soil,which immobilized 96.05%Cd^(2+)from medium.Cd distribution analysis demonstrated that more than half of the Cd^(2+)was converted into extracellular precipitated Cd through mobilization of the alkali-producing mechanism by the strain LYX-2,achieving the high immobilization efficiency of Cd^(2+).Biosorption experiments revealed that strain LYX-2 had superior biosorption capacity of 48.28 mg/g for Cd.Pot experiments with Brassica rapa L.were performed with and without strain LYX-2.Compared to control,15.92%bioavailable Cd was converted to non-bioavailable Cd and Cd content in aboveground vegetables was decreased by 37.10%with addition of strain LYX-2.Available Cd was mainly immobilized through extracellular precipitation,cell-surface biosorption and intracellular accumulation of strain LYX-2,which was investigated through Cd distribution,Scanning Electron Microscope and Energy-Dispersive X-ray Spectroscopy(SEM-EDS),Fourier Transform Infrared Spectroscopy(FT-IR),X-ray Photoelectron Spectroscopy(XPS)and Transmission Electron Microscopy(TEM)analysis.In addition,the application of strain LYX-2 significantly promoted the growth of vegetables about 2.4-fold.Above results indicated that highly Cd-resistant alkalizing strain LYX-2,as a novel microbial passivator,had excellent ability and reuse value to achieve the remediation of Cd-contaminated soil coupled with safe production of vegetables simultaneously.

关键词： Cadmium Enterobacter sp.LYX-2 Cd Immobilization Microbial passivator

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Factors hindering the degradation of pharmaceuticals from human urine in an iron-activated persulfate system

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Journal of Environmental Sciences 2024年第1期135卷 130-148页

作者： Yiruiwen xie Dao Guan Yangfan Deng Yugo Sato Yu luo Guanghao Chen Department of Civil and Environmental Engineering Water Technology LabHong Kong Branch of Chinese National Engineering Research Center for Control&Treatment of Heavy Metal PollutionThe Hong Kong University of Science&TechnologyHong Kong 999077China

This study investigated the degradation of clofibric acid(CFA),bezafibrate(BZF),and sulfamethoxazole(SMX)in synthetic human urine using a novel mesoporous iron powderactivated persulfate system(mFe-PS system),and identified the factors limiting their degradation in synthetic human urine.A kinetic model was established to expose the radical production in various reaction conditions,and experiments were conducted to verify the modeling results.In the phosphate-containing mFe-PS system,the 120 min removal efficiency of CFA decreased from 95.1%to 76.6%as the phosphate concentration increased from 0.32 to 6.45 mmol/L,but recovered to 90.5%when phosphate concentration increased to 16.10 mmol/L.Meanwhile,the increased concentration of phosphate from 0.32 to 16.10mmol/L reduced the BZF degradation efficacy from 91.5%to 79.0%,whereas SMX removal improved from 37.3%to 62.9%.The m Fe-PS system containing(bi)carbonate,from 4.20 to166.70 mmol/L,reduced CFA and BZF removal efficiencies from 100%to 76.8%and 80.4%,respectively,and SMX from 83.5%to 56.7%within a 120-min reaction time.In addition,alkaline conditions(pH≥8.0)inhibited CFA and BZF degradations,while nonacidic pH(pH≥7.0)remarkably inhibited SMX degradation.Results of the kinetic model indicated the formation of phosphate(H_(2)PO_(4)^(·)/HPO_(4)^(·-))and/or carbonate radicals(CO_(3)^(·-))could limit pharmaceutical removal.The transformation products(TPs)of the pharmaceuticals revealed more incompletely oxidized TPs occurred in the phosphate-and(bi)carbonate-containing m Fe-PS systems,and indicated that H_(2)PO_(4)^(·)/HPO_(4)^(·-)mainly degraded pharmaceuticals via a benzene ring-opening reaction while CO_(3)^(·-)preferentially oxidized pharmaceuticals via a hydroxylation reaction.

关键词： Pharmaceutical degradation Human urine Iron-activated persulfate system Phosphate radicals Carbonate radicals Transformation products

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Cerebral furin deficiency causes hydrocephalus in mice

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Genes & Diseases 2024年第3期11卷 438-451页

作者： Shiqi xie Xiaoyong xie Jing Tang Biao luo Jian Chen Qixin Wen Jianrong Zhou Guojun Chen Nursing College Chongqing Medical UniversityChongqing 400016China Department of Neurology The First Affiliated Hospital of Chongqing Medical UniversityChongqing Key Laboratory of Major Neurological and Mental DisordersChongqing Key Laboratory of NeurologyChongqing 400016China

Furin is a pro-protein convertase that moves between the trans-Golgi network and cell surface in the secretory pathway.We have previously reported that cerebral overexpres-sion of furin promotes cognitive functions in mice.Here,by generating the brain-specific furin conditional knockout(ckO)mice,we investigated the role of furin in brain development.We found that furin deficiency caused early death and growth retardation.Magnetic resonance im-aging showed severe hydrocephalus.In the brain of furin cko mice,impaired ciliogenesis and the derangement of microtubule structures appeared along with the down-regulated expres-sion of RAB28,a ciliary vesicle protein.In line with the widespread neuronal loss,ependymal cell layers were damaged.Further proteomics analysis revealed that cell adhesion molecules including astrocyte-enriched ITGB8 and BCAR1 were altered in furin cKO mice;and astrocyte overgrowth was accompanied by the reduced expression of sox9,indicating a disrupted differ-entiation into ependymal cells.Together,whereas alteration of RAB28 expression correlated with the role of vesicle trafficking in ciliogenesis,dysfunctional astrocytes might be involved in ependymal damage contributing to hydrocephalus in furin ckO mice.The structural and mo-lecular alterations provided a clue for further studying the potential mechanisms of furin.

关键词： Astrocyte Ciliogenesis Conditionalknockout Ependymal Furin Hydrocephalus Proteomics

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Impairment of Autophagic Flux After Hypobaric Hypoxia Potentiates Oxidative Stress and Cognitive Function Disturbances in Mice

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Neuroscience Bulletin 2024年第1期40卷 35-49页

作者： Shuhui Dai Yuan feng Chuanhao Lu Hongchen Zhang Wenke Ma Wenyu xie Xiuquan Wu Peng luo Lei Zhang Fei Fei Zhou Fei Xia Li Department of Neurosurgery Xijing HospitalFourth Military Medical UniversityXi'an 710000China National Translational Science Center for Molecular Medicine and Department of Cell Biology Fourth Military Medical UniversityXi'an 710000China Department of Neurosurgery The Central Hospital of BaojiBaoji 721000China Department of Ophthalmology Xijing HospitalFourth Military Medical UniversityXi'an 710000China

Acute hypobaric hypoxic brain damage is a potentially fatal high-altitude sickness.Autophagy plays a critical role in ischemic brain injury,but its role in hypo-baric hypoxia(HH)remains unknown.Here we used an HH chamber to demonstrate that acute HH exposure impairs autophagic activity in both the early and late stages of the mouse brain,and is partially responsible for HH-induced oxidative stress,neuronal loss,and brain damage.The autophagic agonist rapamycin only promotes the initiation of autophagy.By proteome analysis,a screen showed that protein dynamin2(DNM2)potentially regulates autophagic flux.Overexpression of DNM2 significantly increased the formation of autolysosomes,thus maintaining autophagic flux in combination with rapamycin.Furthermore,the enhancement of autophagic activity attenuated oxidative stress and neurological deficits after HH exposure.These results contribute to evidence supporting the conclusion that DNM2-mediated autophagic flux represents a new therapeutic target in HH-induced brain damage.

关键词： Autophagy-Proteomics Oxidative stress Hypobaric hypoxia-Brain injury

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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

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