检索结果-南通市图书馆

维普期刊数据库博看期刊

High-dose dexamethasone regulates microglial polarization via the GR/JAK1/STAT3 signaling pathway after traumatic brain injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2611-2623页

作者： Mengshi Yang Miao Bai Yuan Zhuang Shenghua Lu Qianqian Ge Hao Li Yu Deng Hongbin Wu xiaojian xu Fei Niu Xinlong Dong Bin Zhang Baiyun Liu Beijing Tiantan Hospital Capital Medical UniversityBeijingChina Department of Neurology The First Hospital of Tsinghua UniversityBeijingChina Department of Neurotrauma and Beijing Key Laboratory of Central Nervous System Injury Beijing Neurosurgical InstituteCapital Medical UniversityBeijingChina Department of Critical Care Medicine Beijing Tiantan HospitalCapital Medical UniversityBeijingChina Center for Nerve Injury and Repair Beijing Institute of Brain DisordersChina National Clinical Research Center for Neurological DiseasesBeijingChina

Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently *** potent anti-inflammato ry agents,the use of glucoco rticoids in traumatic brain injury is still controversial,and their regulatory effects on microglial polarization are not yet *** the present study,we sought to determine whether exacerbation of traumatic brain injury caused by high-dose dexamethasone is related to its regulatory effects on microglial polarization and its mechanisms of *** vitro cultured BV2 cells and primary microglia and a controlled cortical impact mouse model were used to investigate the effects of dexamethasone on microglial ***,dexamethasone,RU486(a glucocorticoid receptor antagonist),and ruxolitinib(a Janus kinase 1 antagonist)were ***-sequencing data obtained from a C57BL/6 mouse model of traumatic brain injury were used to identify potential targets of *** Morris water maze,quantitative reverse transcription-polymerase chain reaction,western blotting,immunofluorescence and confocal microscopy analysis,and TUNEL,Nissl,and Golgi staining were performed to investigate our ***-throughput sequencing results showed that arginase 1,a marker of M2 microglia,was significantly downregulated in the dexamethasone group compared with the traumatic brain injury group at3 days post-traumatic brain *** dexamethasone inhibited M1 and M2 microglia,with a more pronounced inhibitory effect on M2microglia in vitro and in *** receptor plays an indispensable role in microglial polarization after dexamethasone treatment following traumatic brain ***,glucocorticoid receptor activation increased the number of apoptotic cells and neuronal death,and also decreased the density of dendritic spines.A possible downstream receptor signaling mechanism is th

关键词： apoptosis BV2 microglia dexamethasone glucocorticoid receptor glucocorticoids innate immune system microglial polarization neuroinflammation primary microglia traumatic brain injury

High-dose dexamethasone regulates microglial polarization via the GR/JAK1/STAT3 signaling pathway after traumatic brain injury

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第09期 2611-2623页

作者： Mengshi Yang Miao Bai Yuan Zhuang Shenghua Lu Qianqian Ge Hao Li Yu Deng Hongbin Wu xiaojian xu Fei Niu Xinlong Dong Bin Zhang Baiyun Liu Beijing Tiantan Hospital Capital Medical University Department of Neurology The First Hospital of Tsinghua University Department of Neurotrauma and Beijing Key Laboratory of Central Nervous System Injury Beijing Neurosurgical InstituteCapital Medical University Department of Critical Care Medicine Beijing Tiantan HospitalCapital Medical University Center for Nerve Injury and Repair Beijing Institute of Brain DisordersChina National Clinical Research Center for Neurological Diseases

Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently *** potent anti-inflammato ry agents,the use of glucoco rticoids in traumatic brain injury is still controversial,and their regulatory effects on microglial polarization are not yet *** the present study,we sought to determine whether exacerbation of traumatic brain injury caused by high-dose dexamethasone is related to its regulatory effects on microglial polarization and its mechanisms of *** vitro cultured BV2 cells and primary microglia and a controlled cortical impact mouse model were used to investigate the effects of dexamethasone on microglial ***,dexamethasone,RU486(a glucocorticoid receptor antagonist),and ruxolitinib(a Janus kinase 1 antagonist) were ***-sequencing data obtained from a C57BL/6 mouse model of traumatic brain injury were used to identify potential targets of *** Morris water maze,quantitative reverse transcription-polymerase chain reaction,western blotting,immunofluorescence and confocal microscopy analysis,and TUNEL,Nissl,and Golgi staining were performed to investigate our ***-throughput sequencing results showed that arginase 1,a marker of M2 microglia,was significantly downregulated in the dexamethasone group compared with the traumatic brain injury group at3 days post-traumatic brain *** dexamethasone inhibited M1 and M2 microglia,with a more pronounced inhibitory effect on M2microglia in vitro and in *** receptor plays an indispensable role in microglial polarization after dexamethasone treatment following traumatic brain ***,glucocorticoid receptor activation increased the number of apoptotic cells and neuronal death,and also decreased the density of dendritic spines.A possible downstream receptor signaling mechanism is t

关键词：

基于5G网络与夜视系统的高速铁路昼夜实时监控技术

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国铁路 2024年第8期 131-138页

作者：宋明徐晓建中国铁道科学研究院集团有限公司标准计量研究所浙江大华技术股份有限公司

随着铁路事业的高速发展，为保障铁路安全运营，对视频监控摄像机的要求越来越高，现有视频监控摄像机已无法满足当前需求，亟须研发一种新型的产品实现超越，达到昼夜连续智能监控的目的。利用激光补光技术，对激光亮度、激光功率、激... 详细信息

随着铁路事业的高速发展，为保障铁路安全运营，对视频监控摄像机的要求越来越高，现有视频监控摄像机已无法满足当前需求，亟须研发一种新型的产品实现超越，达到昼夜连续智能监控的目的。利用激光补光技术，对激光亮度、激光功率、激光光斑等进行提升分析。基于成像技术、图像处理技术和图像增强技术，对图像的清晰度、颗粒度和还原度能力进行优化分析，并建立适用于铁路智能分析的模型库，构建适用于铁路线路特征的算法模型。应用视频可伸缩的编码算法，分析智能5G网络感知系统，感知网络性能的变化，由网络的变化触发视频编码变化。通过上述研究分析，提出关键技术方案、技术手段及解决途径，为提升摄像机夜视、AI智能分析和5G网络承载视频业务能力等方面提供技术支撑。

关键词：夜视补光夜视成像 AI智能分析 5G网络视频业务

基于改进SBR技术的地面目标SAR图像快速生成技术

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

电波科学学报 2024年第2期39卷 322-331页

作者：单敬喆曲晓杰晁坤许小剑北京航空航天大学电子信息工程学院北京100191 中国电波传播研究所青岛266107

传统的弹跳射线(shooting and bouncing ray,SBR)技术主要适用于自由空间目标的电磁散射计算,当用于地面目标与背景复合场景的电磁散射计算和合成孔径雷达(synthetic aperture radar,SAR)图像建模与仿真时,在小擦地角下其计算误差显著... 详细信息

传统的弹跳射线(shooting and bouncing ray,SBR)技术主要适用于自由空间目标的电磁散射计算,当用于地面目标与背景复合场景的电磁散射计算和合成孔径雷达(synthetic aperture radar,SAR)图像建模与仿真时,在小擦地角下其计算误差显著增大。针对此问题,提出了一种基于“四路径”模型的改进SBR技术,其考虑了目标与邻域地面之间的多次反射效应以及目标与远区地面之间的多径散射效应对地面目标散射回波的影响。首先构建一个尺寸略大于目标包围盒的粗糙地面实体模型;然后结合“镜像法”改进射线追踪技术,分析电磁波在目标各部件间、目标同实体地面之间以及同虚拟半空间分界面之间的射线传播过程;最后结合高频渐近方法完成电磁散射计算。利用精确数值法计算结果对所提出技术进行了验证,并将其应用于地面目标的SAR图像高逼真度仿真,同实测SAR图像比对表明了所提技术具有良好的适用性。

关键词：电磁散射合成孔径雷达(SAR) 地面目标弹跳射线(SBR)技术 “四路径”模型

维普期刊数据库博看期刊

Angular glint calculation and analysis of radar targets via adaptive cross approximation algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2014年第3期25卷 411-421页

作者： Miao Sui xiaojian xu School of Electronics and Information Engineering Beihang University

Angular glint is a significant electromagnetic （EM） scattering signature of extended radar targets. Based on the adaptive cross approximation （ACA） algorithm accelerated method of moments （MoM） and the plane incident wave assumption, the narrowband, wideband and newly developed high-resolution range profile （HRRP） based angular glint calculation formulations are derived and applied to arbitrarily shaped three-dimensional （3D） perfectly electrical y conducting （PEC） objects. In addition, the near-field angular glint is emphasized, which is of great importance for radarseeker applications. Furthermore, with the HRRP based angular glint, an approach to rigorously determine range resolution cel s which own relatively smal er angular glint is provided. Numerical results are presented with new findings to demonstrate the usefulness of the developed formulations.

关键词： electromagnetic (EM) scattering radar signature,near-field multistatic scattering.

Wave Propagation Characteristics in Thick Conventional and Auxetic Cellular Plates

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2016年第2期29卷 159-166页

作者： xiaojian xu Zichen Deng Key Laboratory for Special Area Highway Engineering of Ministry of Education School of HighwayChang'an University Department of Engineering Mechanics Northwestern Polytechnical University

Based on Mindlin plate models and Kirchhoff plate models,this study was concerned with the wave propagation characteristics in thick conventional and auxetic cellular structures,with the objective to clarify the effects of negative Poisson＇s ratio,shear factor and orthotropic mechanical properties on the dynamic behaviors of thick *** results revealed that the predictions using variable shear factor in Mindlin plate models resulted in high wave frequencies,which were more significant for plates with negative values of Poisson＇s *** present study can be useful for the design of critical applications by varying the values of Poisson＇s ratio.

关键词： auxetic cellular structure plate frequency shear factor negative Poisson's ratio

Ultrawide-band radar imagery from multiple incoherent frequency subband measurements

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2011年第3期22卷 398-404页

作者： xiaojian xu Jia Li School of Electronic and Information Engineering Beihang UniversityBeijing 100191P.R.China Department of Electrical Computer and Systems EngineeringRensselaer Polytechnic InstituteTroy NY12180USA

The problem of combined radar imagery from multiple sparse frequency subbands initially incoherent to each other is of practical importance for radar target discrimination.A new coherent processing technique based on probability density analysis of the subband data is proposed,which is applicable for radar imaging from measurements of two or more initially incoherent radar *** coherence parameters for both amplitude and phase are obtained by combining modern spectral analysis with probability density *** major advantage of the proposed technique lies in that it enables much more robust cohering for the sparse subband data of real-world complex targets.

关键词： radar imagery coherent processing subband spectral analysis.

Doppler spectral analysis for time-evolving sea surfaces using second-order small slope approximation

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2011年第5期22卷 754-759页

作者： Xiaofei Li xiaojian xu School of Electronics and Information Engineering Beihang University Beijing 100191 P. R. China

The second-order small slope approximation （SSA2） method is introduced to study the Doppler characteristics from time-evolving sea surfaces. Simulation results show better agreement between the SSA2 model and the numerical method for both vertical and horizontal polarizations, meaning that SSA2 gives a satisfactory prediction of the spectral difference between two po- larizations; while such discrepancy cannot be captured using the lowest-order SSA （SSA1） model. In particular, the Doppler shifts and spectral widths for different incident angles, wind directions and polarizations are analyzed, demonstrating correct variations with respect to such parameters. Those observations prove that the SSA2 provides an efficient and relatively fast tool for sea surface Doppler spectral analysis.

关键词： rough sea surface electromagnetic scattering sma slope approximation Doppler spectra.

Analytical solutions for buckling of size-dependent Timoshenko beams

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2019年第7期40卷 953-976页

作者： xiaojian xu Mulian ZHENG Key Laboratory for Special Area Highway Engineering of Ministry of Education School of Highway Chang'an University Xi'an 710064 China Department of Engineering Mechanics Northwestern Polytechnical University Xi'an 710072 China

The inconsistences of the higher-order shear resultant expressed in terms of displacement(s) and the complete boundary value problems of structures modeled by the nonlocal strain gradient theory have not been well addressed. This paper develops a size-dependent Timoshenko beam model that considers both the nonlocal effect and strain gradient effect. The variationally consistent boundary conditions corresponding to the equations of motion of Timoshenko beams are reformulated with the aid of the weighted residual method. The complete boundary value problems of nonlocal strain gradient Timoshenko beams undergoing buckling are solved in closed forms. All the possible higher-order boundary conditions induced by the strain gradient are selectively suggested based on the fact that the buckling loads increase with the increasing aspect ratios of beams from the conventional mechanics point of view. Then, motivated by the expression for beams with simply-supported (SS) boundary conditions, some semiempirical formulae are obtained by curve fitting procedures.

关键词： buckling strain gradient theory boundary condition