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Exosomes originating from neural stem cells undergoing necroptosis participate in cellular communication by inducing TSC2 upregulation of recipient cells following spinal cord injury

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Neural Regeneration Research 2025年第11期20卷 3273-3286页

作者： Shiming li jianfeng li Guoliang Chen Tao lin Penghui Zhang Kuileung Tong Ningning Chen Shaoyu liu Shenzhen Key Laboratory of Bone Tissue Repair and Translational Research Department of Orthopedic SurgeryThe Seventh Affiliated HospitalSun Yat-sen UniversityShenzhenGuangdong ProvinceChina Department of Orthopedic Surgery The First Affiliated Hospital of Jinan UniversityGuangzhouGuangdong ProvinceChina Department of Orthopedics and Traumatology Zhujiang HospitalSouthern Medical UniversityGuangzhouGuangdong ProvinceChina Department of Orthopedic Surgery The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Department of Orthopedic Surgery The First Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina

We previously demonstrated that inhibiting neural stem cells necroptosis enhances functional recovery after spinal cord *** exosomes are recognized as playing a pivotal role in neural stem cells exocrine function,their precise function in spinal cord injury remains *** investigate the role of exosomes generated following neural stem cells necroptosis after spinal cord injury,we conducted singlecell RNA sequencing and validated that neural stem cells originate from ependymal cells and undergo necroptosis in response to spinal cord ***,we established an in vitro necroptosis model using neural stem cells isolated from embryonic mice aged 16-17 days and extracted *** results showed that necroptosis did not significantly impact the fundamental characteristics or number of *** sequencing of exosomes in necroptosis group identified 108 differentially expressed messenger RNAs,104 long non-coding RNAs,720 circular RNAs,and 14 microRNAs compared with the control *** of a competing endogenous RNA network identified the following hub genes:tuberous sclerosis 2(Tsc2),solute carrier family 16 member 3(Slc16a3),and forkhead box protein P1(Foxp1).Notably,a significant elevation in TSC2 expression was observed in spinal cord tissues following spinal cord ***2-positive cells were localized around SRY-box transcription factor 2-positive cells within the injury ***,in vitro analysis revealed increased TSC2 expression in exosomal receptor cells compared with other *** assessment of cellular communication following spinal cord injury showed that Tsc2 was involved in ependymal cellular communication at 1 and 3 days post-injury through the epidermal growth factor and midkine signaling *** addition,Slc16a3 participated in cellular communication in ependymal cells at 7 days post-injury via the vascular endothelial growth factor and macrophage migration inhibitory factor signaling

关键词： cellular communication competing endogenous RNA exosomes Foxp1 necroptosis neural stem cells Slc16a3 spinal cord injury transcriptome sequencing Tsc2

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Low complexity DOA estimation for massive UCA with single snapshot

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Journal of Systems Engineering and Electronics 2022年第1期33卷 22-27页

作者： li Ping li jianfeng ZHAO Gaofeng College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China

In this paper, a low complexity direction of arrival(DOA) estimation method for massive uniform circular array(UCA) with single snapshot is ***, the coarse DOAs are estimated by finding the peaks from the circular convolution between a fixed coefficient vector and the received data ***, in order to refine coarse DOA estimates, we reconstruct the direction matrix based on the coarse DOA estimations and take the first order Taylor expansion with DOA estimation offsets into ***, the refined estimations are obtained by compensating the offsets, which are obtained via least squares(LS) without any complex *** addition, the refinement can be iteratively implemented to enhance the estimation *** to the offset search method, the proposed method achieves a better estimation performance while requiring lower *** simulations are presented to demonstrate the effectiveness of the proposed method.

关键词： direction of arrival(DOA)estimation massive uniform circular array Taylor expansion low complexity

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Correlation between Single Factor Material Constitutive Model Parameters and Temperature for Ti6Al4V Alloy

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Chinese Journal of Mechanical Engineering 2010年第5期23卷 574-581页

作者： YANG Yong li jianfeng SUN Jie Department of Mechanical Engineering Qingdao Technological University Qingdao 266033 China Department of Mechanical Engineering Shandong University Jinan 250061 China

Accurate material constitutive model is considered highly necessary to perform finite element simulation and ***,it is difficult to establish the material constitutive model because of uncertainty of mathematical relationship and constraint of existing experimental *** present,there exists considerable gap between finite element simulation result and actual cutting *** emphases were put on investigating the correlation between ＂single factor＂ material constitutive model parameters and temperature for Ti6Al4V alloy,and also establishment of material constitutive model for this kind of *** analyses based on dislocation theory and material functional relations showed that material model was deeply affected by variation *** the least squares best fit to the available quasi-static and high-speed impact compression experiment data,material parameters at various temperatures were *** curves analyses and material parameters comparison showed that the ＂single factor＂ material constitutive model parameters were temperature *** the mathematical mapping between material parameters and temperature,＂single factor＂ material constitutive model of Ti6Al4V alloy was established,which was proven to be right by comparing with experimental *** work makes clear that the ＂single factor＂ material constitutive model parameters of Ti6Al4V alloy are temperature *** the same time,an accurate material constitutive model is established,which helps to optimize cutting process and control machining distortion for Ti6Al4V alloy aerospace parts.

关键词： metal cutting Ti6Al4V alloy finite element method material constitutive model

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Adaptive Cascaded High-Resolution Source Localization Based on Collaboration of Multi-UAVs

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China Communications 2020年第4期17卷 165-179页

作者： Yi He jianfeng li Xiaofei Zhang College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space Nanjing University of Aeronautics and AstronauticsNanjing 211106China

Effective information fusion is very important in hybrid source localization. In this paper, the performance analysis of conventional joint direction of arrival(DOA) and time difference of arrival(TDOA) system is derived and it is shown that this hybrid system may inferior to the single system when the ratio of angular measurements error to distance measurements error exceeds a threshold. To avoid this problem, an effective DOA/TDOA adaptive cascaded(DTAC) technique is presented. The rotation feature of UAVs and spatial filtering technique are applied to gain the signal-to-noise ratio(SNR), which leads to more accurate estimation of time delay by using DOAs. Nevertheless, the time delay estimation precision is still limited by the sampling frequency, which is constrained by the finite load of UAV. To break through the limitation, an enhanced self-delay-compensation(SDC) method is proposed, which aims at detecting the overlooked time delay within the sampling interval by adding a tiny time delay. Finally, the position of the source is estimated by the Chan algorithm. Compared to DOA-only algorithm, TDOA-only algorithm and joint DOA/TDOA(JDT) algorithm, the proposed method shows better localization accuracy regardless of different SNRs and sampling frequencies. Numerical simulations are presented to validate the effectiveness and robustness of the proposed algorithm.

关键词： source localization multi-UAVs adaptive cascaded high-resolution direction of arrival(DOA) time difference of arrival(TDOA) self-delay-compensation(SDC)

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高精度惯量积测量的支撑结构设计研究

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北京理工大学学报 2025年第1期45卷 52-59页

作者：荣吉利李剑峰周晓俊李亮杨梓航刘睿程修妍北京理工大学宇航学院北京100081 北京航天控制仪器研究所北京100039

针对惯性仪表组件高精度惯量积测量中的无干扰力矩支撑方式需求,设计了径向气浮和轴向气浮相结合的组合气体轴承作为非接触支撑结构.为了研究支撑结构的承载能力,建立其理论模型,结合计算流体力学进行仿真,同时设计并搭建试验装置验证... 详细信息

针对惯性仪表组件高精度惯量积测量中的无干扰力矩支撑方式需求,设计了径向气浮和轴向气浮相结合的组合气体轴承作为非接触支撑结构.为了研究支撑结构的承载能力,建立其理论模型,结合计算流体力学进行仿真,同时设计并搭建试验装置验证仿真的准确性.研究表明仿真与试验结果相近,并且发现非接触支撑结构的轴向承载力是惯量积测量时的薄弱处,结合参数化建模开展了轴向承载力提升研究.结果表明:增大支撑结构中的转子套筒大径有利于提高轴向承载力;结构改进后,轴向承载力提升182.98%,惯量积测量时的旋转速度上限提升54.10%,测量精度提升42.11%.

关键词：组合气体轴承承载能力数值模拟非接触支撑惯量积

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A novel micro-rolling&incremental sheet forming hybrid process:Deformation behavior and microstructure evolution

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Chinese Journal of Aeronautics 2024年第5期37卷 603-622页

作者： Yanle li Feifei liU Hao YUAN Xiaoqiang li jianfeng li Guoqun ZHAO Key Laboratory of High Efficiency and Clean Mechanical Manufacture Ministry of EducationShandong UniversityJi'nan 250061China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Key Laboratory for liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJi'nan 250061China

Thin-walled metal parts with functional micro-featured surface have broad application prospects in the fields of resistance reduction,noise reduction,*** this study,a novel micro-rolling&incremental sheet forming hybrid process(μR-ISF)is proposed to fabricate thin-walled metal parts with microgroove *** analytical model which relates the rolling force and microgroove depth in the micro-rolling stage was first ***,the formation mechanism of microgroove morphology during both micro-rolling stage and macro-shape forming stage are *** the micro-grooved sheet being incrementally formed,a significant reduction(between 21%to nearly 60%)is occurred in the depth of both transverse and longitudinal grooves compared to the flat ***,the width of transverse grooves decreases slightly by about 10%on average,while the width of longitudinal microgrooves increases significantly by more than 30%on *** micro-rolling,85°{102}tensile twins appear on the micro-grooved sheet and the percentage of 65°{112}compressive twins *** incremental forming,the percentage of low-angle grain boundaries and the density of geometrically necessary dislocations in the formed part increase significantly,and the grain size distribution becomes more *** present work provides a new strategy for the fabrication of 3D metal thin-walled components with surface micro-features.

关键词： Incremental sheet forming Microgrooves rolling Surface micromachining Groove size Microstructural evolution

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Microfibrous entrapped ZnO-CaO/Al_2O_3 for high efficiency hydrogen production via methanol steam reforming

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Particuology 2010年第3期8卷 225-230页

作者： Ying Tang li Chen Miaomiao Wang jianfeng li Yong Lu Shanghai Key Laboratory of Green Chemistry and Chemical Processes Department of Chemistry East China Normal University Shanghai 200062 China

Sinter-locked microfibrous networks consisting of -3 vol.% of 8 p.m （dia.） nickel microfibers have been utilized to entrap -30vo1.% of 100-200 μm dia. porous AI203. ZnO and CaO were then highly dispersed onto the pore surface of entrapped A1203 by the incipient wetness impregnation method. Due to the unique combination of surface area, pore size/particle size, thermal conductivity, and void volume, the resulting microfibrous catalyst composites provided significant improvement of catalytic bed reactivity and utilization efficiency when used in methanol steam reforming. Roughly 260 mL/min of reformate, comprising 〉70% H2, 〈5% CO and trace CH4, with 〉97% methanol conversion, could be produced in a I cm3 bed volume of our novel microfihrous entrapped ZnO-CaO/Al2O3 catalyst composite at 470℃ with a high weight hourly space velocity （WHSV） of 15 h-1 using steam/methanol （1.3/1） mixture as feedstock. Compared to a packed bed of 100-200μm ZnO-CaO/Al2O3, our composite bed provided a doubling of the reactor throughput with a halving of catalyst usage.

关键词： Hydrogen Monolithic catalyst Methanol steam reforming ZnO CaO Fuel cells

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High-Precision Time Delay Estimation Based on Closed-Form Offset Compensation

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Computer Modeling in Engineering & Sciences 2023年第3期134卷 2123-2136页

作者： Yingying li Hang Jiang lianjie Yu jianfeng li The Key Laboratory of Dynamic Cognitive Systemof Electromagnetic Spectrum Space Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing211106China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou570100China

To improve the estimation accuracy,a novel time delay estimation(TDE)method based on the closed-form offset compensation is ***,we use the generalized cross-correlation with phase transform(GCC-PHAT)method to obtain the initial ***,a signal model using normalized cross spectrum is established,and the noise subspace is extracted by eigenvalue decomposition(EVD)of covariance *** the orthogonal relation between the steering vector and the noise subspace,the first-order Taylor expansion is carried out on the steering vector reconstructed by the initial ***,the offsets are compensated via simple least squares(LS).Compared to other state-of-the-art methods,the proposed method significantly reduces the computational complexity and achieves better estimation *** on both simulation and real-world data verify the efficiency of the proposed approach.

关键词： Time delay estimation(TDE) time difference of arrival(TDOA) taylor expansion super-resolution

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Mobility Analysis of the Deployable Structure of SLE Based on Screw Theory

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Chinese Journal of Mechanical Engineering 2013年第4期26卷 793-800页

作者： SUN Yuantao WANG Sanmin li jianfeng ZHI Changjian School of Mechanical Engineering Northwestern Polytechnical University

Scissor-like element has a number of applications in deployable structures such as planar deployable structure (PDS) and ring deployable structure(RDS). However, the mobility analysis of the multi-loop deployable structures is made more difficulty by the traditional mobility formula, because the deployable structure is a very complex structure with multi-loop. Therefore, On the basis of screw theory, the calculation method of mobility of deployable structures of SLE is thoroughly discussed. In order to investigate the mobility, decomposing and composing structures(DCS) are developed, and the basic units are able to be obtained. On the basis of the deployable structures’ geometrical characteristics, there exists a closed-loop quadrilateral structure and some non-closed-loop quadrilateral structures in PDS. Also, a six legs parallel structure is present in RDS. The basic units’ mobility can be solved by both the methods of screw theory and topology constraint graphs. Then, composing the related basic units, the formula of planar deployable structures’ mobility can be built and solves the mobility of ring deployable structure. The analysis method solves the mobility analysis of the multi-loop deployable structures which is difficulty by the traditional method, and plays an important role in further research about the mobility of other complex deployable structures.

关键词： Scissor-like element(SLE) screw theory decomposing and composing structures (DCS) mobility

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Review on Stress Corrosion and Corrosion Fatigue Failure of Centrifugal Compressor Impeller

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Chinese Journal of Mechanical Engineering 2015年第2期28卷 217-225页

作者： SUN Jiao CHEN Songying QU Yanpeng li jianfeng School of Mechanical Engineering Shandong University Research Center for Sustainable Manufacturing Shandong University Key Laboratory of High efficiency and Clean Mechanical Manufacture Ministry of Education Shandong University

Corrosion failure,especially stress corrosion cracking and corrosion fatigue,is the main cause of centrifugal compressor impeller *** it is concealed and *** paper summarizes the main theories of stress corrosion cracking and corrosion fatigue and its latest developments,and it also points out that existing stress corrosion cracking theories can be reduced to the anodic dissolution（AD）,the hydrogen-induced cracking（HIC）,and the combined AD and HIC *** corrosion behavior and the mechanism of corrosion fatigue in the crack propagation stage are similar to stress corrosion *** effects of stress ratio,loading frequency,and corrosive medium on the corrosion fatigue crack propagation rate are analyzed and *** corrosion behavior and the mechanism of stress corrosion cracking and corrosion fatigue in corrosive environments,which contain sulfide,chlorides,and carbonate,are *** working environments of the centrifugal compressor impeller show the behavior and the mechanism of stress corrosion cracking and corrosion fatigue in different corrosive *** current research methods for centrifugal compressor impeller corrosion failure are *** analysis,numerical simulation,and the fluid-structure interaction method play an increasingly important role in the research on impeller deformation and stress distribution caused by the joint action of aerodynamic load and centrifugal load.

关键词： stress corrosion cracking corrosion fatigue stainless steel centrifugal compressor impeller

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