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Small extracellular vesicles from hypoxia-preconditioned bone marrow mesenchymal stem cells attenuate spinal cord injury via miR-146a-5p-mediated regulation of macrophage polarization

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Neural Regeneration Research 2024年第10期19卷 2259-2269页

作者： Zeyan Liang Zhelun Yang Haishu Xie Jian Rao Xiongjie Xu yike lin Chunhua Wang Chunmei Chen Department of Neurosurgery Fujian Medical University Union HospitalFuzhouFujian ProvinceChina Fujian Neurosurgical Institute FuzhouFujian ProvinceChina

Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.

关键词： bone marrow mesenchymal stem cells hypoxia preconditioning interleukin-1 receptor-associated kinase 1 macrophages mesenchymal stem cells small extracellular vesicles spinal cord injury

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Mesenchymal stem cell-derived extracellular vesicles therapy in traumatic central nervous system diseases:a systematic review and meta-analysis

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Neural Regeneration Research 2023年第11期18卷 2406-2412页

作者： Zhelun Yang Zeyan Liang Jian Rao Fabin lin yike lin Xiongjie Xu Chunhua Wang Chunmei Chen Department of Neurosurgery Fujian Medical University Union HospitalFuzhouFujian ProvinceChina

Although there are challenges in treating traumatic central nervous system diseases,mesenchymal stem cell-de rived extracellular vesicles(MSC-EVs) have recently proven to be a promising non-cellular the rapy.We comprehensively evaluated the efficacy of mesenchymal stem cell-de rived extracellular vesicles in traumatic central nervous system diseases in this meta-analysis based on preclinical studies.Our meta-analysis was registered at PROSPERO(CRD42022327904,May 24,2022).To fully retrieve the most relevant articles,the following databases were thoro ughly searched:PubMed,Web of Science,The Cochrane Library,and Ovid-Embase(up to April 1,2022).The included studies were preclinical studies of mesenchymal stem cell-derived extracellular vesicles for traumatic central nervous system diseases.The Systematic Review Centre for Laboratory Animal Experimentation(SYRCLE)’s risk of bias tool was used to examine the risk of publication bias in animal studies.After screening 2347studies,60 studies were included in this study.A meta-analysis was conducted for spinal co rd injury(n=52) and traumatic brain injury(n=8).The results indicated that mesenchymal stem cell-derived extracellular vesicles treatment prominently promoted motor function recovery in spinal co rd injury animals,including rat Basso,Beattie and Bresnahan locomotor rating scale scores(standardized mean difference [SMD]:2.36,95% confidence interval [CI]:1.96-2.76,P <0.01,I2=71%) and mouse Basso Mouse Scale scores(SMD=2.31,95% CI:1.57-3.04,P=0.01,I2=60%) compared with controls.Further,mesenchymal stem cell-de rived extracellular vesicles treatment significantly promoted neurological recovery in traumatic brain injury animals,including the modified N eurological Severity Score(SMD=-4.48,95% CI:-6.12 to-2.84,P <0.01,I2=79%) and Foot Fault Test(SMD=-3.26,95% CI:-4.09 to-2.42,P=0.28,I2=21%) compared with controls.Subgroup analyses showed that characteristics may be related to the therapeutic effect of mesenchymal stem cell-de rived extra cellular vesicles.For Basso,Bea

关键词： animals central nervous system diseases extracellular vesicles mesenchymal stromal cell meta-analysis spinal cord injury traumatic brain injury

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超高输电铁塔的气动噪声特性研究

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噪声与振动控制 2024年第2期44卷 82-87页

作者：贺伟军潘巍巍郑新龙卢正通林晓波吴易科国网浙江省电力有限公司舟山供电公司浙江舟山316000

超高输电铁塔在保障居民日常生活和工业生产中起到了重要作用,由于极高的高度,其在风荷载作用下产生的气动噪声问题不容忽视。本文针对超高输电铁塔气动噪声扰民的问题,建立了其计算流体力学(Computational Fluid Dynamics,CFD)计算模型... 详细信息

超高输电铁塔在保障居民日常生活和工业生产中起到了重要作用,由于极高的高度,其在风荷载作用下产生的气动噪声问题不容忽视。本文针对超高输电铁塔气动噪声扰民的问题,建立了其计算流体力学(Computational Fluid Dynamics,CFD)计算模型,采用标准k-ε湍流方程进行稳态初场的计算,并在此基础上采用大涡模拟方法与声类比方法进行瞬态流场计算及气动噪声计算,分析流场的流动特性及气动噪声特性。结果表明,4根主纵梁以及电梯井的左右两侧具有强烈的压力脉动,是主要的气动噪声源,其最大值出现在电梯井顶端区域;各虚拟测点的总声压级沿高度先增加后减小,总声压级沿高度的变化由风速与输电铁塔自身结构尺度参数共同控制;通过声成像测量方法确定了声源的在塔身中部以上、横担以下的位置,验证了仿真结果的正确性;声压级与风速的峰值出现的时刻基本吻合,输电铁塔风致噪声与风速存在着强相关性。本文的研究结论对于超高输电塔气动噪声特性的研究和输电塔的降噪设计具有指导意义。

关键词：声学超高输电铁塔气动噪声计算流体力学大涡模拟 FW-H声类比

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Generation of color-controllable room-temperature phosphorescence via luminescent center engineering and in-situ immobilization

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Chinese Chemical Letters 2023年第7期34卷 193-199页

作者： Licheng Zheng Kai Jiang Jiaren Du yike Li Zhongjun Li Hengwei lin International Joint Research Center for Photo-responsive Molecules and Materials School of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China College of Chemistry and Molecular Engineering Zhengzhou UniversityZhengzhou 450001China

Materials with controllable luminescence colors are highly desirable for numerous promising applications, however, the preparation of such materials, particularly with color-controllable room-temperature phosphorescence(RTP), remains a formidable challenge. In this work, we reported on a facile strategy to prepare color-controllable RTP materials via the pyrolysis of a mixture containing 1-(2-hydroxyethyl)-urea(H-urea) and boric acid(BA). By controlling the pyrolysis temperatures, the as-prepared materials exhibited ultralong RTP with emission colors ranging from cyan, green, to yellow. Further studies revealed that multiple luminescent centers formed from H-urea, which were in-situ embedded in the B2O3matrix(produced from BA) during the pyrolysis process. The contents of the different luminescent centers could be regulated by the pyrolysis temperatures, resulting in color-tunable RTP. Significantly, the luminescent center engineering and in-situ immobilization strategy not only provided a facile method for conveniently preparing color-controllable RTP materials, but also endowed the materials prepared at relatively lower temperatures with color-changeable RTP features under thermal stimulus. Considering their unique properties, the potential applications of the as-obtained materials for advanced anti-counterfeiting and information encryption were preliminarily demonstrated.

关键词： Carbon dots Room-temperature phosphorescence Luminescent center engineering In-situ immobilization Anti-counterfeiting Information security

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真空气淬工艺对模具钢Cr12MoV组织和性能的影响

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锻压技术 2024年第5期49卷 226-234页

作者：汪拥进占克勤裴薇邵光保唐学峰蒙祎珂李古海朱琳胡盛德湖北三环锻造有限公司湖北谷城441700 武汉科技大学材料学部湖北武汉430081 华中科技大学材料成形与模具技术国家实验室湖北武汉430074

针对Cr12MoV钢常规热处理后不能同时具备高硬度和冲击韧性的问题,开展了Cr12MoV钢的真空热处理强韧化研究。以奥氏体化温度、奥氏体化保温时间、气淬压力、低温等温温度以及低温等温时间5个关键工艺参数设计了Cr12MoV钢的真空气淬正交试... 详细信息

针对Cr12MoV钢常规热处理后不能同时具备高硬度和冲击韧性的问题,开展了Cr12MoV钢的真空热处理强韧化研究。以奥氏体化温度、奥氏体化保温时间、气淬压力、低温等温温度以及低温等温时间5个关键工艺参数设计了Cr12MoV钢的真空气淬正交试验,以洛氏硬度和冲击韧性作为材料的强韧性评价指标,利用极差方法分析了热处理工艺参数对Cr12MoV钢材料性能的影响。利用金相显微镜、扫描电子显微镜对Cr12MoV钢真空气淬后的微观组织进行了观察,分析了热处理工艺参数对Cr12MoV钢材料微观组织的影响。结果表明:低温等温温度、奥氏体化温度和气淬压力3个工艺参数对Cr12MoV钢真空热处理后的硬度和冲击韧性影响最大,而奥氏体化保温时间影响最小,最终获得了综合性能较好的马氏体/下贝氏体复相组织。

关键词： Cr12MoV钢真空等温气淬硬度冲击韧性组织演变

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Tumor-specific and photothermal-augmented chemodynamic therapy by ferrocene-carbon dot-crosslinked nanoparticles

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SmartMat 2022年第2期3卷 311-322页

作者： Shan Sun Qiao Chen yike Li Yao Yu Zhongjun Li Hengwei lin School of Chemical and Material Engineering International Joint Research Center for Photo-responsive Molecules and MaterialsJiangnan UniversityWuxiChina Mechanobiology and Regenerative Medicine Laboratory Bioengineering CollegeChongqing UniversityChongqingChina College of Chemistry and Molecular Engineering Zhengzhou UniversityZhengzhouChina Department of Cardiovascular Thoracic Surgery Tianjin Medical University General HospitalTianjinChina

Extensive research have been devoted to the exploration of multifunctional theranostic agents for cancer,but the poor tumor specificity and unsatisfactory treatment efficacy are some of the critical obstacles for their clinical translations.Herein,ferrocene-carbon dot-crosslinked nanoparticles(Fc-CD NPs)were designed and fabricated for achieving highly specific and photothermal-augmented chemodynamic therapy(CDT).The Fc-CD NPs were found not only to inherit the immanent fluorescence,photoacoustic,and photothermal properties of carbon dots(CDs),but also be endowed with CDT that could occur selectively in tumor microenvironment(TME)due to the presence of Fc for triggering Fenton reaction.Moreover,the enlarged particle size of Fc-CD NPs facilitated their effective accumulation at tumor sites,thus realizing great improvement for antitumor treatment outcomes.Once docking at tumor and being exposed to 660 nm laser irradiation,significantly amplified CDT effect of Fc-CD NPs was observed due to heataccelerating generation of reactive oxygen species(ROS).More interestingly,since the produced ROS could in turn alleviate the thermal-resistance of photothermal therapy(PTT),the therapeutic efficiency of integrated PTT and CDT was synergized to the maximum extent.This study on the one hand provides a facile approach to fabricate CDs-based multifunctional theranostic nanoplatform with enhanced tumor accumulation and specificity,on the other hand emphasizes the merits of synergizing mutually beneficial therapeutic modalities for more efficient cancer therapy.

关键词： carbon dots crosslinked nanoparticles ferrocene synergistic therapy tumor specificity

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基于深度学习的城市街道景观视觉质量分析与研究——以天津市鼓楼街道为例

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景观设计 2024年第1期22卷 22-25页

作者：邹尚恩林朝杨瀚文胡一可天津大学建筑学院中交第二公路工程局有限公司华西公司

城市街道景观是城市整体景观的重要组成部分,直接影响人们对城市环境的感知与评价。以天津市鼓楼街道为例,利用街景图像数据和LaDeco景观视觉评估模型,深入分析城市街道景观的视觉要素,包括自然和人工景观的比例、主要视觉要素、形态特... 详细信息

城市街道景观是城市整体景观的重要组成部分,直接影响人们对城市环境的感知与评价。以天津市鼓楼街道为例,利用街景图像数据和LaDeco景观视觉评估模型,深入分析城市街道景观的视觉要素,包括自然和人工景观的比例、主要视觉要素、形态特征及景观特征的粒度信息。结果表明,鼓楼街道以人工景观为主,自然景观不稳定且不连贯;主要视觉要素包括街道、天空和建筑,LaDeco模型能有效识别这些要素;道路、天空和建筑是街道景观的主要形态特征,其中道路占比较高,而建筑和天空影响着城市环境的审美感知;景观的布局、比例和相对位置共同构建了整体视觉印象,对街道形象和城市环境产生重要影响。提供了一种有效的评估方式,能快速、客观地计算图像中视觉要素的比例,为城市街道景观的研究、规划和评估提供新的思路和方法。

关键词：城市街道景观评估街景图像深度学习景观视觉要素

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2022北京冬奥会管控下新乡市农村地区PM_(2.5)中重金属及生态风险变化特征

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环境科学学报 2024年第1期44卷 47-61页

作者：王光奇王玲玲马双良王一克赵文鹏马琳李红亮黄皓旻范丽雅叶代启华南理工大学环境与能源学院广州510006 河南省生态环境监测和安全中心郑州450000 河南省新乡生态环境监测中心新乡453000 挥发性有机物污染治理技术与装备国家工程实验室广州510006 广东省大气环境与污染控制重点实验室广州510006 广东省环境风险防控与应急处置工程技术研究中心广州510006

细颗粒物(PM_(2.5))中的重金属威胁着人体健康和生态环境.本文基于2022年北京冬奥会期间新乡市采取的不同污染管控措施,于2022年1月20日—2月20日在新乡市一个农村站点对PM_(2.5)进行逐小时采样,并检测了其中20种重金属元素的浓度,研究... 详细信息

细颗粒物(PM_(2.5))中的重金属威胁着人体健康和生态环境.本文基于2022年北京冬奥会期间新乡市采取的不同污染管控措施,于2022年1月20日—2月20日在新乡市一个农村站点对PM_(2.5)进行逐小时采样,并检测了其中20种重金属元素的浓度,研究了不同管控阶段(管控前阶段P1、严格管控阶段P2、宽松管控阶段P3)新乡市农村地区重金属污染特征及其与管控措施的关系.结果表明:严格管控期间Zn、Pb、Mn、As、Se、Hg、Cr和Ni的浓度明显下降,降幅分别为50.2%、29.3%、39.1%、67.9%、33.4%、27.7%、51.9%和32.2%,其中,As和Cr的污染程度(I_(geo))显著降低,降幅分别为34.3%和27.8%,其余元素的I_(geo)仅轻微降低或未降低.宽松管控期间Mn、Cr、Ni的浓度和I_(geo)均显著上升,浓度分别上升49.8%、26.3%和17.4%,I_(geo)分别上升27.9%、21.1%和22.5%.日变化分析表明,严格管控措施下K、Ca、Pb和As的日变化特征与其他时段有所不同,其余元素则无显著差异.此外,严格管控期间气象条件对所测元素的作用也与其他时段不同,表现得更为复杂.新乡市农村地区重金属的潜在生态风险等级为极高(生态风险综合指数>1200),其中,风险最高的元素为Cd、Se、Pb、As(生态风险指数:64~12714).污染程度和潜在生态风险均较高的4种元素为Cd、As、Pb、Se,其浓度权重轨迹(CWT)结果显示Cd的主要潜在源区在山东中南部,而其余3种元素的潜在源区则集中在河北东南部,且不同阶段的潜在源区有一定差异.

关键词：北京冬奥会新乡农村 PM_(2.5) 重金属生态风险潜在源

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Green and Near-Infrared Dual-Mode Afterglow of Carbon Dots and Their Applications for Confidential Information Readout

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Nano-Micro Letters 2021年第12期13卷 148-162页

作者： Yuci Wang Kai Jiang Jiaren Du Licheng Zheng yike Li Zhongjun Li Hengwei lin College of Chemistry Zhengzhou UniversityZhengzhou 450001People’s Republic of China International Joint Research Center for Photo-Responsive Molecules and Materials School of Chemical and Material EngineeringJiangnan UniversityWuxi 214122People’s Republic of China Key Laboratory of Graphene Technologies and Applications of Zhejiang Province Ningbo Institute of Materials Technology&Engineering(NIMTE)Chinese Academy of SciencesNingbo 315201People’s Republic of China

Near-infrared(NIR),particularly NIR-containing dual-/multimode afterglow,is very attractive in many fields of application,but it is still a great challenge to achieve such property of materials. Herein,we report a facile method to prepare green and NIR dual-mode afterglow of carbon dots(CDs) through in situ embedding o-CDs(being prepared from o-phenylenediamine) into cyanuric acid(CA) matrix(named o-CDs@CA). Further studies reveal that the green and NIR afterglows of o-CDs@CA originate from thermal activated delayed fluorescence(TADF) and room temperature phosphorescence(RTP) of o-CDs,respectively. In addition,the formation of covalent bonds between o-CDs and CA,and the presence of multiple fixation and rigid e ects to the triplet states of o-CDs are confirmed to be critical for activating the observed dual-mode afterglow. Due to the shorter lifetime and insensitiveness to human vision of the NIR RTP of o-CDs@CA,it is completely covered by the green TADF during directly observing. The NIR RTP signal,however,can be readily captured if an optical filter(cut-o wavelength of 600 nm) being used. By utilizing these unique features,the applications of o-CDs@CA in anti-counterfeiting and information encryption have been demonstrated with great confidentiality. Finally,the as-developed method was confirmed to be applicable to many other kinds of CDs for achieving or enhancing their afterglow performances.

关键词： Carbon dots Dual-mode afterglow Room temperature phosphorescence Thermal activated delayed fluorescence Information security

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自磨改性对再生粗骨料及再生混凝土性能的影响

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材料导报 2023年第16期37卷 157-162页

作者：林一柯何廷树达永琪西安建筑科技大学材料科学与工程学院西安710055

提出了一种新的再生骨料改性技术即自磨改性,系统研究了该技术对再生粗骨料和再生混凝土性能的影响规律,探究了再生微粉附着于再生骨料表面时,对再生混凝土工作性能及力学性能的影响规律。结果表明:自磨改性可以有效改善再生粗骨料的粒... 详细信息

提出了一种新的再生骨料改性技术即自磨改性,系统研究了该技术对再生粗骨料和再生混凝土性能的影响规律,探究了再生微粉附着于再生骨料表面时,对再生混凝土工作性能及力学性能的影响规律。结果表明:自磨改性可以有效改善再生粗骨料的粒形和界面形貌,有利于附着表面砂浆层的剥离,改性后再生粗骨料的表观密度提高了9.7%,压碎指标及吸水率分别降低了37.6%和51.4%,改善了再生混凝土的流动性和黏聚性,有效提升了再生混凝土的抗压强度。再生微粉颗粒尺寸小且表面疏松多孔,同时具有微集料填充效应和火山灰活性,对再生混凝土的后期强度具有明显的提升作用。

关键词：自磨改性再生粗骨料再生混凝土再生微粉二次水化

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