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Artificial Self-Recovery Opens up a New Journey of Autonomous Health of Mechanical Equipments

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Engineering 2024年第6期37卷 22-26页

作者： Xin Pan Haoyu Zhang Jinji Gao Weimin Wang Zhinong Jiang Lidong He Beijing Key Laboratory of Health Monitoring and Self-recovery for High-end Mechanical Equipment Beijing University of Chemical TechnologyBeijing 100029China Engineering Research center of Chemical Safety Ministry of Education Beijing University of Chemical TechnologyBeijing 100029China

*** With the implementation of modern production strategies,such as“Industry 4.0”and“Made in China 2025,”the development of high-end mechanical equipment is gradually reaching a high degree of parameterization,digitalization,networking,and intelligence[1].High-end mechanical equipment no longer consists of traditional single devices,but is closely linked to the overall production process;that is,a variety of devices interact with each other and collectively form a complex ***,faults can lead to production delays throughout the system and even seriously threaten the safety of workers[2].In addition,equipment operating in unmanned air or space vehicles(including space robots)cannot be repaired by humans if they break down[3].Until recently,the typical method of addressing machine faults was primarily the“fault cure”method,which involves manually shutting down,inspecting,and repairing the equipment to restore normal ***,the maintenance cycle of the traditional“fault cure”method is time-consuming,and the quality of the maintenance depends on the skills of the technician[4].

关键词： collective consuming Open

Molecular Dynamics Simulation Studies on the Micromorphology and Proton Transport of Nafion/Ti_(3)C_(2)T_(x) Composite Membrane

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Chinese Journal of Polymer Science 2024年第3期42卷 373-387,I0009页

作者： Zhi-Yue Han Su-Peng Pei Chun-Yang Yu Yong-Feng Zhou School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai 201418China School of Chemistry&Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Key Laboratory of Electrical Insulation and Thermal AgingShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Green and High-end Utilization of Salt Lake Resources Chinese Academy of SciencesXining 810008China

The perfluorosulfonic acid(PFSA) membrane doped with two-dimensional conductive filler Ti_(3)C_(2)T_(x) is a fuel cell proton exchange membrane with high application potential. Experimental studies showed that the proton conductivity of Nafion/Ti_(3)C_(2)T_(x) composite membrane is improved significantly compared with that in pure Nafion. However, the microscopic mechanism of doping on the enhancement of membrane performance is remain unclear now. In this work, molecular dynamics simulation was used to investigate the microscopic morphology and proton transport behaviors of Nafion/Ti_(3)C_(2)T_(x) composite membrane at the molecular level. The results shown that there were significant differences about the diffusion kinetics of water molecules and hydroxium ions in Nafion/Ti_(3)C_(2)T_(x) at low and high hydration levels in the nanoscale *** the increase of water content, Ti_(3)C_(2)T_(x) in membrane was gradually surrounded by ambient water molecules to form a hydration layer, and forming a relatively continuous proton transport channel between Nafion polymer and Ti_(3)C_(2)T_(x) monomer. The continuous proton transport channel could increase the number of binding sites of proton and thus achieving high proton conductivity and high mobility of water molecules at higher hydration level. The current work can provide a theoretical guidance for designing new type of Nafion composite membranes.

关键词： Nafion/Ti_(3)C_(2)T_(x)composite membrane Proton transport Molecular dynamics simulation

Transient state analysis of a rub-impact rotor system during maneuvering flight

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Chinese Journal of Aeronautics 2024年第7期37卷 236-251页

作者： Jun WANG Yunfei LIU Zhaoye QIN Liang MA Fulei CHU Beijing Key Laboratory of Health Monitoring and Self-Recovery for High-end Machinery Equipment Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Tribology Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China College of Aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China

Maneuvering flight substantially affects the dynamic behavior of rotors;particularly,such flight may cause rubbing between a rotor and stator,which is one of the most serious damages in aircraft *** this paper,a nonlinear dynamic model for describing the dynamic characteristics of a rub-impact rotor system during maneuvering flight is established based on the Lagrange ***,numerical simulations employing the Newmark method are performed,delving into the detailed discussion of the influence of parameters such as rotational speed and maneuvering flight on the transient and steady-state responses of the rotor *** effect mechanism of maneuver load and its coupling with rub impact is *** results show that the impact response induced by maneuvering flight is more obvious in the subcritical state than in the supercritical *** additional stiffness and damping are also induced;in particular,the additional damping has a coupling ***,the rub impact imposes an additional constraint on the rotor system,thereby weakening the influence of the maneuver load and becoming the major factor that determines the dynamic behavior of the rotor system at high speeds.

关键词： Maneuvering flight Rub impact Rotor system Dynamic response Impact response

Intelligent Diagnosis Method for Typical Co-frequency Vibration Faults of Rotating Machinery Based on SAE and Ensembled ResNet-SVM

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Chinese Journal of Mechanical Engineering 2024年第4期 228-243页

作者： Xiancheng Zhang Xin Pan Hao Zeng Haofu Zhou Beijing Key Laboratoryof Health Monitoring and Self-recovery for High-end Mechanical Equipment Beijing University of Chemical Technology Engineering Research center of Chemical Safety (Ministry of Education) Beijing University of Chemical Technology Engineering Management Department of China Three Gorges New Energy (Group) Co. Ltd.

Intelligent fault diagnosis is an important method in rotating machinery fault diagnosis and equipment health management. To deal with co-frequency vibration faults, a type of typical fault in rotating machinery, this paper proposes a fault diagnosis method based on the stacked autoencoder(SAE) and ensembled ResNet-SVM. Furthermore, the time-and frequency-domain features of several co-frequency vibration faults are summarized based on the mechanism analysis and calculated using actual vibration data. To realize and validate the high-precision diagnosis method of rotating equipment with co-frequency faults proposed in this study, the following three criteria are required: First, to improve the effectiveness and robustness of the ensembled model and the sliding window using data augmentation, adding noise, autoencoder(AE) and SAE methods are analyzed in terms of principle and practical effects. Second, ResNet is used as the feature extractor for the ensembled ResNet-SVM model. Feature extraction is carried out twice, and the extracted co-frequency fault features are more comprehensive. Finally, the data augmentation method and ensemble ResNet-SVM are combined for fault diagnosis and compared with other methods. The experimental results show that the accuracy of the proposed method can exceed 99.9%.

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A homing rescue gene drive with multiplexed gRNAs reaches high frequency in cage populations but generates functional resistance

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Journal of Genetics and Genomics 2024年第8期51卷 836-843页

作者： Shibo Hou Jingheng Chen Ruobing Feng Xuejiao Xu Nan Liang Jackson Champer center for Bioinformatics Center for Life SciencesSchool of Life SciencesPeking UniversityBeijing 100871China

CRISPR homing gene drives have considerable potential for managing populations of medically and agriculturally significant *** operate by Cas9 cleavage followed by homology-directed repair,copying the drive allele to the wild-type chromosome and thus increasing in frequency and spreading throughout a ***,resistance alleles formed by end-joining repair pose a significant *** address this,we create a homing drive targeting the essential hairy gene in Drosophila *** resistance alleles are recessive lethal,while drive carriers have a recoded“rescue”version of *** drive inheritance rate is moderate,and multigenerational cage studies show drive spread to 96%–97%of the ***,the drive does not reach 100%due to the formation of functional resistance alleles despite using four *** alleles have a large deletion but likely utilize an alternate start ***,revised designs targeting more essential regions of a gene may be necessary to avoid such functional *** of the rescue element’s native 3'UTR with a homolog from another species increases drive inheritance by 13%–24%.This was possibly because of reduced homology between the rescue element and surrounding genomic DNA,which could also be an important design consideration for rescue gene drives.

关键词： Genedrive Homing drive Rescueelement Population modification Multiplexed gRNAs Resistance alleles Cage study

THE TRUNCATED EM METHOD FOR JUMP-DIFFUSION SDDES WITH SUPER-LINEARLY GROWING DIFFUSION AND JUMP COEFFICIENTS

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Journal of Computational Mathematics 2024年第1期42卷 178-216页

作者： Shounian Deng Chen Fei Weiyin Fei Xuerong Mao Key Laboratory of Advanced Perception and Intelligent Control of High-end Equipment Ministry of Educationand School of Mathematics-Physics and FinanceAnhui Polytechnic UniversityWuhu 241000China Business School University of Shanghai for Science and TechnologyShanghai 200093China Department of Mathematics and Statistics University of StrathclydeGlasgow G11XHUK

This work is concerned with the convergence and stability of the truncated EulerMaruyama(EM)method for super-linear stochastic differential delay equations(SDDEs)with time-variable delay and Poisson *** constructing appropriate truncated functions to control the super-linear growth of the original coefficients,we present two types of the truncated EM method for such jump-diffusion SDDEs with time-variable delay,which is proposed to be approximated by the value taken at the nearest grid points on the left of the delayed *** first type is proved to have a strong convergence order which is arbitrarily close to 1/2 in mean-square sense,under the Khasminskii-type,global monotonicity with U function and polynomial growth *** second type is convergent in q-th(q<2)moment under the local Lipschitz plus generalized Khasminskii-type *** addition,we show that the partially truncated EM method preserves the mean-square and H∞stabilities of the true ***,we carry out some numerical experiments to support the theoretical results.

关键词： SDDEs Truncated EM method Time-variable delay Poisson jumps

Di-and tri-methylation of histone H3K36 play distinct roles in DNA double-strand break repair

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Science China(Life Sciences) 2024年第6期67卷 1089-1105页

作者： Runfa Chen Meng-Jie Zhao Yu-Min Li Ao-Hui Liu Ru-Xin Wang Yu-Chao Mei Xuefeng Chen Hai-Ning Du Hubei Key Laboratory of Cell Homeostasis College of Life SciencesTaiKang Center for Life and Medical SciencesFrontier Science Center for Immunology and MetabolismHubei Clinical Research Center of Emergency and ResuscitationEmergency Center of Zhongnan HospitalWuhan UniversityWuhan 430072China Hubei Key Laboratory of Cell Homeostasis College of Life SciencesTaiKang Center for Life and Medical SciencesFrontier Science Center for Immunology and MetabolismWuhan UniversityWuhan 430072China

Histone H3 Lys36(H3K36)methylation and its associated modifiers are crucial for DNA double-strand break(DSB)repair,but the mechanism governing whether and how different H3K36 methylation forms impact repair pathways is ***,we unveil the distinct roles of H3K36 dimethylation(H3K36me2)and H3K36 trimethylation(H3K36me3)in DSB repair via non-homologous end joining(NHEJ)or homologous recombination(HR).Yeast cells lacking H3K36me2 or H3K36me3 exhibit reduced NHEJ or HR efficiency.y Ku70 and Rfa1 bind H3K36me2-or H3K36me3-modified peptides and chromatin,*** these interactions impairs y Ku70 and Rfa1 recruitment to damaged H3K36me2-or H3K36me3-rich loci,increasing DNA damage sensitivity and decreasing repair ***,H3K36me2-enriched intergenic regions and H3K36me3-enriched gene bodies independently recruit y Ku70 or Rfa1 under DSB ***,human KU70 and RPA1,the homologs of y Ku70 and Rfa1,exclusively associate with H3K36me2 and H3K36me3 in a conserved *** findings provide valuable insights into how H3K36me2 and H3K36me3 regulate distinct DSB repair pathways,highlighting H3K36 methylation as a critical element in the choice of DSB repair pathway.

关键词： histone H3K36 methylation Ku70 RPA non-homologous end joining homologous recombination

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Three-dimensional cell-based strategies for liver regeneration

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BIOCELL 2024年第7期48卷 1023-1036页

作者： DAN GUO XI XIA JIAN YANG Liver Transplant center Transplant CenterWest China HospitalSichuan UniversityChengdu610041China Frontiers Medical center Tianfu Jincheng LaboratoryChengdu610212China

Liver regeneration and the development of effective therapies for liver failure remain formidable challenges in modern *** recent years,the utilization of 3D cell-based strategies has emerged as a promising approach for addressing these urgent clinical *** review provides a thorough analysis of the application of 3D cell-based approaches to liver regeneration and their potential impact on patients with end-stage liver ***,we discuss various 3D culture models that incorporate hepatocytes and stem cells to restore liver function and ameliorate the consequences of liver ***,we explored the challenges in transitioning these innovative strategies from preclinical studies to clinical *** collective insights presented herein highlight the signiﬁcance of 3D cell-based strategies as a transformative paradigm for liver regeneration and improved patient care.

关键词： Three-Dimensional Liver regeneration Organoids Stem cells Cell therapy

SARS-CoV2 Nsp3 protein triggers cell death and exacerbates amyloid β42-mediated neurodegeneration

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Neural Regeneration Research 2024年第6期19卷 1385-1392页

作者： Aditi Singh Anuradha Venkatakrishnan Chimata Prajakta Deshpande Soumya Bajpai Anjali Sangeeth Mrigendra Rajput Amit Singh Department of Biology University of Dayton Premedical Program University of Dayton center for Tissue Regeneration and Engineering at Dayton (TRend) University of Dayton The Integrative Science and Engineering center University of Dayton center for Genomic Advocacy (TCGA) Indiana State University

Infection caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV2) virus, responsible for the coronavirus disease 2019(COVID-19) pandemic, induces symptoms including increased inflammatory response, severe acute respiratory syndrome(SARS), cognitive dysfunction like brain fog, and cardiovascular defects. Long-term effects of SARS-CoV2 COVID-19 syndrome referred to as post-COVID-19 syndrome on age-related progressive neurodegenerative disorders such as Alzheimer’s disease remain understudied. Using the targeted misexpression of individual SARS-CoV2 proteins in the retinal neurons of the Drosophila melanogaster eye, we found that misexpression of nonstructural protein 3(Nsp3), a papain-like protease, ablates the eye and generates dark necrotic spots. Targeted misexpression of Nsp3 in the eye triggers reactive oxygen species production and leads to apoptosis as shown by cell death reporters, terminal deoxynucleotidyl transferase(TdT) dUTP Nick-end labeling(TUNEL) assay, and dihydroethidium staining. Furthermore, Nsp3 misexpression activates both apoptosis and autophagy mechanism(s) to regulate tissue homeostasis. Transient expression of SARS-CoV2 Nsp3 in murine neuroblastoma, Neuro-2a cells, significantly reduced the metabolic activity of these cells and triggers cell death. Misexpression of SARS-CoV2 Nsp3 in an Alzheimer’s disease transgenic fly eye model(glass multiple repeats [GMR]>amyloid β42) further enhances the neurodegenerative rough eye phenotype due to increased cell death. These findings suggest that SARS-CoV2 utilizes Nsp3 protein to potentiate cell death response in a neurodegenerative disease background that has high pre-existing levels of neuroinflammation and cell death.

关键词： Alzheimer's disease apoptosis autophagy COVID-19 Drosophila necrosis Neuro-2a cells neurodegeneration post COVID-19 syndrome SARS-CoV2