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Transplantation of fibrin-thrombin encapsulated human induced neural stem cells promotes functional recovery of spinal cord injury rats through modulation of the microenvironment

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Neural Regeneration Research 2024年第2期19卷 440-446页

作者： Sumei liu Baoguo liu Qian Li tianqi Zheng Bochao liu Mo Li Zhiguo Chen Cell Therapy Center Beijing Institute of GeriatricsXuanwu HospitalCapital Medical UniversityNational Clinical Research Center for Geriatric Diseasesand Key Laboratory of Neurodegenerative DiseasesMinistry of EducationBeijingChina Center of Neural Injury and Repair Beijing Institute for Brain DisordersBeijingChina Center of Parkinson’s Disease Beijing Institute for Brain DisordersBeijingChina

Recent studies have mostly focused on engraftment of cells at the lesioned spinal cord,with the expectation that differentiated neurons facilitate recovery.Only a few studies have attempted to use transplanted cells and/or biomaterials as major modulators of the spinal cord injury microenvironment.Here,we aimed to investigate the role of microenvironment modulation by cell graft on functional recovery after spinal cord injury.Induced neural stem cells reprogrammed from human peripheral blood mononuclear cells,and/or thrombin plus fibrinogen,were transplanted into the lesion site of an immunosuppressed rat spinal cord injury model.Basso,Beattie and Bresnahan score,electrophysiological function,and immunofluorescence/histological analyses showed that transplantation facilitates motor and electrophysiological function,reduces lesion volume,and promotes axonal neurofilament expression at the lesion core.Examination of the graft and niche components revealed that although the graft only survived for a relatively short period(up to 15 days),it still had a crucial impact on the microenvironment.Altogether,induced neural stem cells and human fibrin reduced the number of infiltrated immune cells,biased microglia towards a regenerative M2 phenotype,and changed the cytokine expression profile at the lesion site.Graft-induced changes of the microenvironment during the acute and subacute stages might have disrupted the inflammatory cascade chain reactions,which may have exerted a long-term impact on the functional recovery of spinal cord injury rats.

关键词： biomaterial fibrinogen functional recovery induced neural stem cell transplantation microenvironment microglia spinal cord injury thrombin

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Research on the Voltage Interaction of Multi-Infeed HVDC System and Interaction Factor

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Journal of Power and Energy Engineering 2015年第4期3卷 41-48页

作者： Shengjun Zhou Guangyao Qiao Chuan He Wenhui Wang tianqi liu State Grid Corporation State Grid Smart Gird Research Institute Beijing 102200 China School of Electrical Engineering and Information Sichuan University Chengdu 610065 China

In multi-infeed HVDC system, the interactions and influences between DC systems AC systems are complex as the electrical distances among DC converter stations which are relatively short. Multi-infeed interaction factor (MIIF) can effectively reflect the interaction among DC systems. The paper theoretically analyzes the impact factors of MIIF like the electrical distances between two DC converter stations and the equivalent impedance of the receiving end AC system. By applying the Kirchhoff’s current law on the inverter AC bus, the paper deduces the analytical expressions for MIIF. From the expression, it is clear how the equivalent impedance of AC system and coupling impedance can affect MIIF. PSCAD simulations validate the effectiveness and the correctness of the proposed expression and some useful conclusions are drawn.

关键词： Multi-Infeed HVDC Inverter Bus Voltage Voltage Interaction Interaction Factor Equivalent Impedance Coupling Impedance

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应用于火灾救援机器人的相变胶囊多层堆积热防护数值研究

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沈阳工程学院学报（自然科学版） 2024年第1期20卷 82-88页

作者：王潇李永强刘天奇张国伟沈阳航空航天大学安全工程学院辽宁沈阳110136 沈阳工程学院机械学院辽宁沈阳110136

持续高温的工作环境产生的热量是导致火灾中救援机器人电子元器件失效的主要因素。因此,为了设计合理地保护救援机器人内部电子元器件的热防护结构,利用COMSOL Multiphysics软件分别建立了相变胶囊复合结构、热障-隔热双层结构及玻璃棉... 详细信息

持续高温的工作环境产生的热量是导致火灾中救援机器人电子元器件失效的主要因素。因此,为了设计合理地保护救援机器人内部电子元器件的热防护结构,利用COMSOL Multiphysics软件分别建立了相变胶囊复合结构、热障-隔热双层结构及玻璃棉胶囊复合结构模型,通过数值模拟的方法对比3种结构的热防护性能。然后,通过改变相变胶囊尺寸和堆积方式,设计了相变胶囊单层堆积结构、双层堆积结构和大小胶囊混合堆积结构,进一步探究了相变材料含量和堆积方式对热防护效果的影响。结果表明:应用相变材料的相变胶囊复合结构具有更优秀的热防护性能;在整个加热期内,大尺寸相变胶囊堆积的单层结构内壁平均温升相较于双层堆积结构和混合堆积结构分别降低了41.8%和29%,表现出更优的热防护效果。

关键词：救援机器人热防护相变胶囊数值研究

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误拆电缆导致计量故障的差错电量分析

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农村电气化 2024年第5期 82-84页

作者：廖涛张欲晓赵玉富刘天齐曾信义王平国网河南省电力公司营销服务中心河南郑州450051

以一起因误拆电缆导致关口电能表失压为例,对故障过程进行分析,并阐述差错电量计算的方法及结果。为使结果更合理,采用站内电量平衡法和母线电量平衡法分别进行计算,所得差错电量接近,证明了计算方法的正确性,为类似电能计量故障的分析... 详细信息

以一起因误拆电缆导致关口电能表失压为例,对故障过程进行分析,并阐述差错电量计算的方法及结果。为使结果更合理,采用站内电量平衡法和母线电量平衡法分别进行计算,所得差错电量接近,证明了计算方法的正确性,为类似电能计量故障的分析处理和差错电量的计算提供了参考和依据。

关键词：计量故障关口电能表站内电量平衡法母线电量平衡法

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Rare earth fluorescent nanoprobes with minimal side effects enable tumor microenvironment activation for chemotherapy

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Journal of Rare Earths 2024年第2期42卷 256-262,I0001页

作者： tianqi Cao Yuxin liu Qi Jia Xiaolu Wang Shouqiang Zhang Jing Zhou Department of Chemistry Capital Normal UniversityBeijing100048China

Chemotherapy,the use of antitumor drugs to kill cancer cells,is currently one of the most effective treatments for cancer.However,serious toxic side effects caused by long-term drug accumulation can cause significant damage to the body,which limits the clinical application of antitumor drugs.In this study,a novel RENPs@DOX-Fe nanoprobe(NP) was constructed by coating the surface of rare earth nanomaterials(NaLuF_(4):Yb,Er) with a complex formed by doxorubicin(DOX) and iron ion(Ⅲ).Due to the low toxicity of anthracycline-metal complexes,the damage to normal cells is reduced.The unique acidic microenvironment in tumor cells facilitates the decomposition and gradual release of DOX from the DOX-Fe complex.In addition,the DOX-Fe complex can convert near-infrared(NIR) light into heat energy,which promotes the decomposition of the complex,further enhancing the release of DOX in the tumor environment.The change of ratio fluorescence of rare earth nanomaterials at 660 and 1550 nm after DOX release enables visual monitoring of drug release,which can potentially improve the chemotherapeutic effect.In vitro experiments established that RENPs@DOX-Fe NPs with NIR illumination had good therapeutic efficacy in tumors.This work provides new insights into designing tumor microenvironment-responsive nanoprobes for chemotherapy with minimal side effects.

关键词： Rare earth nanoprobes Fluorescence Ratiometric imaging DOX Chemotherapy

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BIM技术在大型学校项目建设中的应用实践研究

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绿色建造与智能建筑 2024年第2期 29-33页

作者：吕晓欢刘天奇付强王猛猛赵亮深圳市建筑工务署教育工程管理中心深圳518040 深圳市斯维尔科技股份有限公司深圳518057

BIM技术在建筑领域的应用日趋成熟,其具备卓越的数字化、可视化、协同化等特性,可对建筑项目的所有信息进行集成、管理和共享,推动国内建筑行业迈入信息化新时代。在大型建筑项目中,BIM技术尤具优势,该类建筑建设周期长、涉及专业多、... 详细信息

BIM技术在建筑领域的应用日趋成熟,其具备卓越的数字化、可视化、协同化等特性,可对建筑项目的所有信息进行集成、管理和共享,推动国内建筑行业迈入信息化新时代。在大型建筑项目中,BIM技术尤具优势,该类建筑建设周期长、涉及专业多、协调范围广,且构筑物和管线在竖向、横向空间排布较为复杂,需要系统、清晰的全局管控。本文以深圳技术大学(一期)项目为例,阐述BIM技术在大型学校项目建设中的应用和价值,旨在进一步巩固、拓广BIM技术在建筑领域的应用。

关键词： BIM 大型学校数字化可视化应用研究

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虚拟同步发电机技术研究现状

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黑龙江电力 2024年第1期46卷 55-60页

作者：蔡雷蒋晓艳宋朋骏刘天奇牟泓妃西藏农牧学院水利土木工程学院西藏林芝860000 西藏农牧学院电气工程学院西藏林芝860000

随着“十四五”期间新能源开发规模持续增加,电力系统“双高”特性将更加凸显,致使新型电力系统缺少转动惯量与阻尼,频率稳定受到威胁。虚拟同步发电机(VSG)技术引入虚拟惯量与虚拟阻尼,对电网频率的稳定产生支撑作用。通过描述转子机... 详细信息

随着“十四五”期间新能源开发规模持续增加,电力系统“双高”特性将更加凸显,致使新型电力系统缺少转动惯量与阻尼,频率稳定受到威胁。虚拟同步发电机(VSG)技术引入虚拟惯量与虚拟阻尼,对电网频率的稳定产生支撑作用。通过描述转子机械运动方程、无功-电压控制方程介绍VSG控制原理,从有功-频率控制、无功-电压控制、无缝切换技术,归纳总结目前VSG研究热点,并针对VSG存在的功率耦合、限流保护、低电压穿越、多机并联协同控制等问题提供一定的参考思路。

关键词：虚拟同步发电机虚拟惯量功率耦合低电压穿越多机并联

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Time-history performance optimization of flapping wing motion using a deep learning based prediction model

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Chinese Journal of Aeronautics 2024年第5期37卷 317-331页

作者： tianqi WANG liu liu Jun LI Lifang ZENG School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027China Huanjiang Laboratory Zhuji 311800China

Flapping Wing Micro Aerial Vehicles(FWMAVs)have caused great concern in various fields because of their high efficiency and maneuverability.Flapping wing motion is a very important factor that affects the performance of the aircraft,and previous works have always focused on the time-averaged performance optimization.However,the time-history performance is equally important in the design of motion mechanism and flight control system.In this paper,a time-history performance optimization framework based on deep learning and multi-island genetic algorithm is presented,which is designed in order to obtain the optimal two-dimensional flapping wing motion.Firstly,the training dataset for deep learning neural network is constructed based on a validated computational fluid dynamics method.The aerodynamic surrogate model for flapping wing is obtained after the convergence of training.The surrogate model is tested and proved to be able to accurately and quickly predict the time-history curves of lift,thrust and moment.Secondly,the optimization framework is used to optimize the flapping wing motion in two specific cases,in which the optimized propulsive efficiencies have been improved by over 40%compared with the baselines.Thirdly,a dimensionless parameter C_(variation)is proposed to describe the variation of the time-history characteristics,and it is found that C_(variation)of lift varies significantly even under close time-averaged performances.Considering the importance of time-history performance in practical applications,the optimization that integrates the propulsion efficiency as well as C_(variation)is carried out.The final optimal flapping wing motion balances good time-averaged and time-history performance.

关键词： FWMAV Flapping wing motion Deep learning Unsteady aerodynamic performance Optimization Time-history curve

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鲤PPARγ基因序列特征及其与脂肪沉积的相关性

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水产学杂志 2024年第2期37卷 18-25页

作者：周佳刘天奇孙志鹏吉宇丹鲁翠云曹顶臣郑先虎中国水产科学研究院黑龙江水产研究所淡水鱼类育种国家地方联合工程实验室农业农村部淡水水产生物技术与遗传育种重点实验室黑龙江哈尔滨150070 上海海洋大学农业农村部淡水水产种质资源重点实验室上海201306

为探讨过氧化物酶体增殖物激活受体γ(peroxisome proliferator activated receptor,PPARγ)对鲤(Cyprinus carpio)脂肪沉积的调控机制,采用RACE和实时荧光定量PCR技术克隆体质量(215.20±8.21)g鲤的PPARγ基因,分析其组织表达特征。结果显示,PPARγ基因c DNA全长为3 077 bp,包括233 bp的5′非编码区、1 311bp的3′非编码区和编码510个氨基酸的开放阅读框。鲤PPARγ包括4个功能结构域,即A/B区,DNA结合区(DNA binding domain,DBD区),铰链区和配体结合区(ligand binding domain,LBD区)。鲤PPARγ与鲫(Carassius auratus)、斑马鱼(Danio rerio)的氨基酸序列相似性最高,分别为98.63%和87.28%。PPARγ基因在各组织均有表达,肝脏中相对表达量最高,脑次之,脾和心脏中最少。腹腔脂肪中PPARγ基因表达量多脂鲤显著高于少脂鲤(P<0.05),背部肌肉中PPARγ基因表达量多脂鲤极显著高于少脂鲤(P<0.01)。推测PPARγ具有促进脂肪沉积的作用,PPARγ基因可以作为鲤脂肪沉积候选基因用于分子选择。本研究为进一步解析鲤PPARγ基因调控脂肪沉积分子机制研究奠定了理论基础。

关键词：鲤 PPARγ基因基因表达脂肪沉积

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Tailoring the microstructure of Mg-Al-Sn-RE alloy via friction stir processing and the impact on its electrochemical discharge behaviour as the anode for Mg-air battery

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Journal of Magnesium and Alloys 2024年第4期12卷 1554-1565页

作者： Jingjing liu Hao Hu tianqi Wu Jinpeng Chen Xusheng Yang Naiguang Wang Zhicong Shi School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China Hunan Institute of Metrology and Test Changsha 410014China Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

Constructing the magnesium alloy with fine grains,low density of dislocations,and weak crystal orientation is of crucial importance to enhance its comprehensive performance as the anode for Mg-air battery.However,this unique microstructure can hardly be achieved with conventional plastic deformation such as rolling or extrusion.Herein,we tailor the microstructure of Mg-Al-Sn-RE alloy by using the friction stir processing,which obviously refines the grains without increasing dislocation density or strengthening crystal orientation.The Mg-air battery with the processed Mg-Al-Sn-RE alloy as the anode exhibits higher discharge voltages and capacities than that employing the untreated anode.Furthermore,the impact of friction stir processing on the electrochemical discharge behaviour of Mg-Al-Sn-RE anode and the corresponding mechanism are also analysed according to microstructure characterization and electrochemical response.

关键词： Magnesium anode Electrochemical discharge behaviour Mg-air battery Friction stir processing

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