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Advances in therapies using mesenchymal stem cells and their exosomes for treatment of peripheral nerve injury:state of the art and future perspectives

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Neural Regeneration Research 2025年第11期20卷 3151-3171页

作者： Fatima Aldali Chunchu Deng Mingbo Nie Hong chen Department of Rehabilitation Medicine Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei ProvinceChina Department of Orthopedics Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei ProvinceChina

“Peripheral nerve injury”refers to damage or trauma affecting nerves outside the brain and spinal *** nerve injury results in movements or sensation impairments,and represents a serious public health *** severed peripheral nerves have been effectively joined and various therapies have been offered,recovery of sensory or motor functions remains limited,and efficacious therapies for complete repair of a nerve injury remain *** emerging field of mesenchymal stem cells and their exosome-based therapies hold promise for enhancing nerve regeneration and *** stem cells,as large living cells responsive to the environment,secrete various factors and *** latter are nano-sized extracellular vesicles containing bioactive molecules such as proteins,microRNA,and messenger RNA derived from parent mesenchymal stem *** have pivotal roles in cell-to-cell communication and nervous tissue function,offering solutions to changes associated with cell-based *** ongoing investigations,mesenchymal stem cells and mesenchymal stem cell-derived exosome-based therapies are in the exploratory stage.A comprehensive review of the latest preclinical experiments and clinical trials is essential for deep understanding of therapeutic strategies and for facilitating clinical *** review initially explores current investigations of mesenchymal stem cells and mesenchymal stem cell-derived exosomes in peripheral nerve injury,exploring the underlying ***,it provides an overview of the current status of mesenchymal stem cell and exosomebased therapies in clinical trials,followed by a comparative analysis of therapies utilizing mesenchymal stem cells and ***,the review addresses the limitations and challenges associated with use of mesenchymal stem cell-derived exosomes,offering potential solutions and guiding future directions.

关键词： clinical trials exosome extracellular vesicles mesenchymal stem cells nerve regeneration peripheral nerve injury pre-clinical experiments

Different pre-S deletion patterns and their association with hepatitis B virus genotypes

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World Journal of Gastroenterology 2016年第35期22卷 8041-8049页

作者： bing-Fang chen School of Medicine Fu Jen Catholic University New Taipei City 24205 Taiwan

AIM To investigate the associations of different types of pre-S deletions with hepatitis B virus(HBV) *** The sequences of the pre-S region, basal core promoter(BCP) mutation, and precore(PC) mutation were examined through direct DNA sequencing or clonal analysis and sequencing in 273 HBV carriers, namely 55 asymptomatic carriers, 55 carriers with chronic hepatitis(CH), 55 with liver cirrhosis(LC), 53 with liver cirrhotic hepatocellular carcinoma(LC-HCC), and 55 with noncirrhotic HCC. A total of 126 HBV carriers(46.2%) harbored pre-S deletions. The DNA sequences of pre-S deletion mutants from 43 age-matched genotype B(HBV/B)-infected carriers and 43 agematched genotype C(HBV/C)-infected carriers were further examined, aligned, and *** No significant difference was observed in the mean age distribution(P = 0.464), male sex(P = 0.805), viral load(P = 0.635), or BCP mutation(P = 0.117) between the HBV/B and HBV/C groups. However, the rate of PC mutation was significantly higher in the HBV/B-infected carriers than in the HBV/C-infected carriers(P = 0.003). Both genotypes exhibited a high rate of deletion in the C-terminal half of the pre-S1 region and N-terminus of the pre-S2 region(86.0% and 79.1% in the HBV/B group; 69.8% and 72.1% in the HBV/C group, respectively). Epitope mapping showed that deletion in several epitope sites was frequent i n both genotypes, particularly p S1-BT and p S2-B2. Conversely, the rate of p S2-B1 deletion was significantly higher in the HBV/B group(72.1% vs 37.2%, P = 0.002), and the rate of pS 2-T deletion was significantly higher in the HBV/C group(48.8% vs 25.6%, P = 0.044). Functional mapping showed that the rate of deletion in three functional sites(the nucleocapsid binding site, start codon of M, and site for viral secretion) located in the N-terminus of the pre-S2 region was significantly higher in the HBV/B group(P < 0.05). One type of N-terminus pre-S1 deletion mutant with deletion of the start codon of t

关键词： Hepatitis B virus Pre-S deletion Chronic hepatitis Hepatocellular carcinoma Genotype Liver cirrhosis

Reliability evaluation of avionics system with imperfect fault coverage and propagated failure mechanisms

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Chinese Journal of Aeronautics 2020年第12期33卷 3437-3446页

作者： Ying chen Song YANG rui KANG Science and Technology on Reliability and Environmental Engineering Laboratory Beihang UniversityBeijing 100083China

Fault tolerance designs are essential techniques for systems that require high levels of reliability,such as aircraft or spacecraft control *** Fault Coverage(IFC)may lead to the failure of a system or subsystem even with adequate *** studies of IFC mostly concentrated on evaluating Coverage Factor(CF),whereas the system failure behaviors with IFC have rarely been *** that occur in low-layer may be covered by ***,if the coverage is imperfect,uncovered failure will have functional and physical impact on the system *** this thesis,the failure behavior and reliability of IFC of multi-layer systems are studied and a Binary Decision Diagram(BDD)-based modeling and simulation method are proposed to evaluate system *** a case,the failure behavior of an aero engine electronic controller with IFC is *** results show that the IFC may impact system behavior without taking the IFC into account,the system maintenance intervals may reduce,and thus the maintenance costs will increase.

关键词： Acceleration Binary Decision Diagram(BDD) Failure mechanism Imperfect Fault Coverage Multi-layer system Reliability evaluation

An implicit upwind parabolized Navier-Stokes code for chemically nonequilibrium flows

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Acta Mechanica Sinica 2013年第1期29卷 36-47页

作者： bing chen Li Wang Xu Xu School of Astronautics Beihang University

The previously developed single-sweep parabolized Navier-Stokes （SSPNS） space marching code for ideal gas flows has been extended to compute chemically nonequilibrium flows. In the code, the strongly coupled set of gas dynamics, species conservation, and turbulence equations is integrated with the implicit lower-upper symmetric GaussSeidel （LU-SGS） method in the streamwise direction in a space marching manner. The AUSMPW＋ scheme is used to calculate the inviscid fluxes in the crossflow direction, while the conventional central scheme for the viscous fluxes. The k-g two-equation turbulence model is used. The revised SSPNS code is validated by computing the Burrows-Kurkov non-premixed H2/air supersonic combustion flows, premixed H2/air hypersonic combustion flows in a three-dimensional duct with a 15° compression ramp, as well as the hypersonic laminar chemically nonequilibrium air flows around two 10° half-angle cones. The results of these calculations are in good agreement with those of experiments, NASA UPS or Prabhu＇s PNS codes. It can be concluded that the SSPNS code is highly efficient for steady supersonic/ hypersonic chemically reaction flows when there is no large streamwise separation.

关键词： Parabolized Navier-Stokes (PNS) equations Chemical nonequilibrium Space marching algorithm Lower-upper symmetric Gauss-Seidel (LU-SGS) method AUSMPW+ scheme

Minimum Time Extrema Estimation for Large-Scale Radio-Frequency Identification Systems

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Journal of Computer Science & Technology 2020年第5期35卷 1099-1114页

作者： Xiao-Jun Zhu Li-Jie Xu Xiao-bing Wu bing chen College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Jiangsu Key Laboratory of Dig Data Security and Intelligent Processing Nanjing University of Posts and TelecommunicationsNanjing 210049China Wireless Research Centre University of CanterburyChristchurch 8041New Zealand

We consider the extrema estimation problem in large-scale radio-frequency identification(RFID)systems,where there are thousands of tags and each tag contains a finite *** objective is to design an extrema estimation protocol with the minimum execution *** the standard binary search protocol wastes much time due to inter-frame overhead,we propose a parameterized protocol and treat the number of slots in a frame as an unknown *** formulate the problem and show how to find the best parameter to minimize the worst-case execution ***,we propose two rules to further reduce the execution *** first is to find and remove redundant *** second is to concatenate a frame from minimum value estimation with a frame from maximum value estimation to reduce the total number of *** show that,in a typical scenario,the proposed protocol reduces execution time by 79%compared with the standard binary search protocol.

关键词： radio-frequency identification(RFID)system maximum value estimation minimum value estimation time efficient protocol

Dynamic modeling and simulation of a pressurized system used in flight vehicle

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Chinese Journal of Aeronautics 2018年第6期31卷 1232-1248页

作者： bing SUN Qi XU Yang chen School of Astronautics Beihang University

For a typical pressurized system with a novel dual-stage gas pressure reducing regulator,a system model is established with modular models of various typical components. The simulation study on the whole working period shows that the general trends and magnitudes of simulation curves are in agreement with experimental measured curves. As the key component in the pressurized system, the regulator is studied by a series of numerical simulations to reveal the influences of various structure parameters on its stability. Furthermore, the variable ranges which can guarantee the stability of regulator and system are obtained to provide guidance for design. The modeling and analysis approach can be applied to other systems and components.

关键词： Dual-stage gas pressure reducing regulator Dynamic characteristics Finite volume method Numerical simulation Pressurized system Stability

Hepatitis B virus pre-S/S variants in liver diseases

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World Journal of Gastroenterology 2018年第14期24卷 1507-1520页

作者： bing-Fang chen School of Medicine Fu-Jen Catholic University

Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis(CH), liver cirrhosis(LC), and hepatocellular carcinoma(HCC). Because of the spontaneous error rate inherent to viral reverse transcriptase, the hepatitis B virus(HBV) genome evolves during the course of infection under the antiviral pressure of host immunity. The clinical significance of pre-S/S variants has become increasingly recognized in patients with chronic HBV infection. Pre-S/S variants are often identified in hepatitis B carriers with CH, LC, and HCC, which suggests that these naturally occurring pre-S/S variants may contribute to the development of progressive liver damage and hepatocarcinogenesis. This paper reviews the function of the pre-S/S region along with recent findings related to the role of pre-S/S variants in liver diseases. According to the mutation type, five pre-S/S variants have been identified: pre-S deletion, pre-S point mutation, pre-S1 splice variant, C-terminus S point mutation, and pre-S/S nonsense mutation. Their associations with HBV genotype and the possible pathogenesis of pre-S/S variants are discussed. Different pre-S/S variants cause liver diseases through different mechanisms. Most cause the intracellular retention of HBV envelope proteins and induction of endoplasmic reticulum stress, which results in liver diseases. Pre-S/S variants should be routinely determined in HBV carriers to help identify individuals who may be at a high risk of less favorable liver disease progression. Additional investigations are required to explore the molecular mechanisms of the pre-S/S variants involved in the pathogenesis of each stage of liver disease.

关键词： hepatitis B virus pre-S/S mutant pre-S deletion splice variant spPS1 chronic hepatitis liver cirrhosis hepatocellular carcinoma

Preparation and Characterization of Platinum Supported on Carbon Nanotubes with Different Tube Diameter for Cathode Catalysts of Proton Exchange Membrane Fuel Cells

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Journal of Materials Science & Technology 2010年第6期26卷 529-534页

作者： Hong Su bing Zhang Lijuan chen Tecchnical Instituteof Physms and Chemistry of CAS Beijing 100190 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China

Platinum supported on carbon nanotubes （CNTs） with different tube diameters 〈10, 10-20, 40-60 and 60- 100 nm were prepared. The catalysts were characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）. The metal particle size for 40 wt pct Pt catalysts were 2-5 nm. Self-prepared Pt/CNTs catalysts and purchased Pt/XC-72 were studied by polarization curves, and it was found that in the H2/O2 fuel cell system, Pt supported on Vulcan XC-72 （Pt/XC-72） possessed higher catalytic activity than Pt/CNTs. But in H2/air system, Pt supported on CNTs with diameter 10-20 nm （Pt/CNTI020） possessed higher activity than other Pt/C catalysts.

关键词： Fuel cell Pt/C catalyst Carbon nanotubes (CNTs) Catalytic activity

Circular object recognition based on shape parameters

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Journal of Systems Engineering and Electronics 2007年第2期18卷 199-204页

作者： chen Aijun Li Jinzong Zhu bing Inst. of Image Information Technology and Engineering Harbin Inst. of Technology Harbin 150001 P. R. China

To recognize circular objects rapidly in satellite remote sensing imagery, an approach using their geometry properties is presented. The original image is segmented to be a binary one by one dimension maximum entropy threshold algorithm and the binary image is labeled with an algorithm based on recursion technique. Then, shape parameters of all labeled regions are calculated and those regions with shape parameters satisfying certain conditions are recognized as circular objects. The algorithm is described in detail, and comparison experiments with the randomized Hough transformation （RHT） are also provided. The experimental results on synthetic images and real images show that the proposed method has the merits of fast recognition rate, high recognition efficiency and the ability of anti-noise and anti-jamming. In addition, the method performs well when some circular objects are little deformed and partly misshapen.

关键词： Circular object Pattern recognition Shape parameter Region labeling Image segmentation