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173篇 您的检索式:作者名="Xuejun Chen"
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1Research on heart sound identification technology显示文摘In this article,both the basic principles and the experimental methods of identity recognition technology based on heart sounds are addressed.First,the characteristics of heart sounds and the feasibility of heart sounds as a biometric were analyzed.A synthetic model of heart sounds was then developed based on a family of wavelets;Finally,the characteristic parameters of heart sounds were extracted by using the heart sounds linear band frequency cepstra(HS-LBFC)with a specified configuration,and the similarity distance was adopted for heart sound identification.To highlight the difference in two heart sound signals between the time and frequency domains,a construction method of the heart sound wavelet,a calculation method of the parameters of a synthetic model,selection of the characteristic parameters of heart sounds and the corresponding data processing technology were examined.The experimental results showed that the proposed method exhibited excellent performance and practicability.CHENG XieFeng MA Yong LIU Chen ZHANG XueJun GUO YuFeng 2012Science China(Information Sciences)2012,55,2:20
2Chinese progress in geomorphometry显示文摘Geomorphometry,the science of digital terrain analysis(DTA),is an important focus of research in both geomorphology and geographical information science(GIS).Given that 70% of China is mountainous,geomorphological research is popular among Chinese scholars,and the development of GIS over the last 30 years has led to significant advances in geomorphometric research.In this paper,we review Chinese progress in geomorphometry based on the published literature.There are three major areas of progress:digital terrain modelling methods,DTA methods,and applications of digital terrain models(DTMs).First,traditional vector-and raster-based terrain modelling methods,including the assessment of uncertainty,have received widespread attention.New terrain modelling methods such as unified raster and vector,high-fidelity,and real-time dynamic geographical scene modelling have also attracted research attention and are now a major focus of digital terrain modelling research.Second,in addition to the popular DTA methods based on topographical derivatives,geomorphological features,and hydrological factors extracted from DTMs,DTA methods have been extended to include analyses of the structure of underlying strata,ocean surface features and even socioeconomic spatial structures.Third,DTMs have been applied to fields including global climate change,analysis of various typical regions,lunar surface and other related fields.Clearly,Chinese scholars have made significant progress in geomorphometry.Chinese scholars have had the greatest international impact in areas including high-fidelity digital terrain modelling and DTM-based regional geomorphological analysis,particularly in the Loess Plateau and the Tibetan Plateau regions.LV Guonian XIONG Liyang CHEN Min TANG Guoan SHENG Yehua LIU Xuejun SONG Zhiyao LU Yuqi YU Zhaoyuan ZHANG Ka WANG Meizhen 2017Journal of Geographical Sciences2017,27,11:14
3Mechanical properties of gangue-containing aluminosilicate based cementitious materials显示文摘High performance aluminosilicate based cementitious materials were produced using calcined gangue as one of the majorraw materials. The gangue was calcined at 500°C. The main constituent was calcined gangue, fly ash and slag, while alkali-silicatesolutions were used as the diagenetic agent. The structure of gangue-containing aluminosilicate based cementitious materials wasstudied by the methods of IR, NMR and SEM. The results show that the mechanical properties are affected by the mass ratio betweenthe gangue, slag and fly ash, the kind of activator and additional salt. For 28-day curing time, the compressive strength of the samplewith a mass proportion of 2:1:1 (gangue: slag: fly ash) is 58.9 MPa, while the compressive strength of the sample containing 80wt%gangue can still be up to 52.3 MPa. The larger K+ favors the formation of large silicate oligomers with which Al(OH)4? prefers to bind.Therefore, in Na-K compounding activator solutions more oligomers exist which result in a stronger compressive strength of alumino-silicate-based cementitious materials than in the case of Na-containing activator. The reasons for this were found through IR and NMRanalysis. Glauber’s salt reduces the 3-day compressive strength of the paste, but increases its 7-day and 28-day compressive strengths.Huajian Li Henghu Sun Xuejun Xiao Hongxia Chen 2006Journal of University of Science and Technology Beijing2006,13,2:14
4MicroRNA-191 targets N-deacetylase/N-sulfotransferase 1 and promotes cell growth in human gastric carcinoma cell line MGC803显示文摘作为基因表示的 post-transcriptional 管理者的一个家庭, microRNAs (miRNAs ) 控制包括房间区别,增长和 apoptosis 的生物进程的一个宽数组,和 miRNAs 的 dysregulation 是癌症的一个特点。这里,我们发现 microRNA-191 (miR-191 ) 在在人的胃的腺癌房间线 MGC803 和人的胃的癌症纸巾的高表示的水平。-2,5-diphenyltetrazolium 溴化物和殖民地形成试金显示出的 3-(4,5-dimethylthiazol-2-yl ) 的结果那 miR-191 能支持房间生长并且压制 MGC803 房间的 apoptosis。N-deacetylase/N-sulfotransferase 1 (NDST1 ) 被证实是提高的绿色边的 miR-191 的直接目标基因荧光灯蛋白质记者实验。NDST1 的 mRNA 和蛋白质层次相反地在 MGC803 房间与 miR-191 被相关,建议由 miR-191 的 NDST1 的否定规定。而且, NDST1 起了一个禁止的作用并且能压制 MGC803 房间增长。我们的调查结果建议 miR-191 能在 MGC803 房间充当 oncogene,并且细胞的功能部分由于它 NDST1 的否定规定。Xuejun Shi Shicang SU Jian Long Bing Mei Yajun Chen 2011Acta Biochimica et Biophysica Sinica2011,43,11:12
5m^6A Regulates Neurogenesis and Neuronal Development by Modulating Histone Methyltransferase Ezh2显示文摘N6-methyladenosine (m6A),catalyzed by the methyltransferase complex consisting of Mettl3 and Mettl14,is the most abundant RNA modification in mRNAs and participates in diverse biological processes. However,the roles and precise mechanisms of m6A modification in regulating neuronal development and adult neurogenesis remain unclear. Here,we examined the function of Mettl3,the key component of the complex,in neuronal development and adult neurogenesis of mice. We found that the depletion of Mettl3 significantly reduced m6A levels in adult neural stem cells (aNSCs) and inhibited the proliferation of aNSCs. Mettl3 depletion not only inhibited neu-ronal development and skewed the differentiation of aNSCs more toward glial lineage,but also affected the morphological maturation of newborn neurons in the adult brain. m6A immunoprecip-itation combined with deep sequencing (MeRIP-seq) revealed that m6A was predominantly enriched in transcripts related to neurogenesis and neuronal development. Mechanistically,m6A was present on the transcripts of histone methyltransferase Ezh2,and its reduction upon Mettl3 knockdown decreased both Ezh2 protein expression and consequent H3K27me3 levels. The defects of neurogenesis and neuronal development induced by Mettl3 depletion could be rescued by Ezh2 overexpression. Collectively,our results uncover a crosstalk between RNA and histone modifica-tions and indicate that Mettl3-mediated m6A modification plays an important role in regulating neurogenesis and neuronal development through modulating Ezh2.Junchen Chen Yi-Chang Zhang Chunmin Huang Hui Shen Baofa Sun Xuejun Cheng Yu-Jie Zhang Yun-Gui Yang Qiang Shu Ying Yang Xuekun Li 2019Genomics, Proteomics & Bioinformatics2019,17,2:12
6Aircraft conflict resolution method based on hybrid ant colony optimization and artificial potential field显示文摘Dear editor, With the significant growth of the civil aviation industry and especially its rapid development in booming economies such as that of China,air traffic flow is drastically increasing,leading to greater congestion around airport terminal areas and in busy airspace [i].The substantial increase in air traffic flow has intensified the risk of violating safe separation regulations,endangering the airspace operational safety.Furthermore,as the result of this significant growth has resulted in problems such as longer delays,which increase fuel consumption and cost the airline industry billions of dollars every year [2,3].Huaxian LIU Feng LIU Xuejun ZHANG Xiangmin GUAN Jun CHEN Pascal SAVINAUD 2018Science China(Information Sciences)2018,61,12:11
7A large-scale multi-objective flights conflict avoidance approach supporting 4D trajectory operation显示文摘Recently, the long-term conflict avoidance approaches based on large-scale flights scheduling have attracted much attention due to their ability to provide solutions from a global point of view. However, current approaches which focus only on a single objective with the aim of minimizing the total delay and the number of conflicts, cannot provide controllers with variety of optional solutions, representing different tradeoffs. Furthermore, the flight track error is often overlooked in the current research. Therefore, in order to make the model more realistic, in this paper, we formulate the long-term conflict avoidance problem as a multi-objective optimization problem, which minimizes the total delay and reduces the number of conflicts simultaneously. As a complex air route network needs to accommodate thousands of flights, the problem is a large-scale combinatorial optimization problem with tightly coupled variables, which make the problem difficult to deal with. Hence,in order to further improve the search capability of the solution algorithm, a cooperative co-evolution(CC)algorithm is also introduced to divide the complex problem into several low dimensional sub-problems which are easier to solve. Moreover, a dynamic grouping strategy based on the conflict detection is proposed to improve the optimization efficiency and to avoid premature convergence. The well-known multi-objective evolutionary algorithm based on decomposition(MOEA/D) is then employed to tackle each sub-problem. Computational results using real traffic data from the Chinese air route network demonstrate that the proposed approach obtained better non-dominated solutions in a more effective manner than the existing approaches, including the multi-objective genetic algorithm(MOGA), NSGAII, and MOEA/D. The results also show that our approach provided satisfactory solutions for controllers from a practical point of view.Xiangmin GUAN Xuejun ZHANG Renli LV Jun CHEN Weiszer MICHAL 2017Science China(Information Sciences)2017,60,11:8
8Interactions of Sn and S and their effects on the magnetic properties of non-oriented silicon steel sheets显示文摘The interactions of Sn and S and their effects on the magnetic properties of non-oriented silicon steel sheets were discussed in reference to industrial production.Results show that minor amounts of Sn can improve magnetic induction sharply but have little effect on core loss when the S content is below 10×10-4%.The precipitation of AIN can be restrained effectively by Sn.Sn,as the nucleus,can remove some of the inclusions with a size of 0.5μm or larger,but has little effect on inclusions smaller than 0.5μm,which is the key factor affecting core loss.Sn improves the magnetic induction of finished steel sheets mainly through the change of the steel texture.The relationship between the magnetic induction and Sn and S content can be regressed as B50= 1.69 -4.37 ws+0.30 wSn.From the regression formulation,the magnetic induction can be improved by 0.03 T when 0.01%Sn is added under relatively low S content conditions.ZHANG Feng WANG Bo LV Xuejun CHEN Lingyun 2013Baosteel Technical Research2013,7,2:8
9Electrochemically driven conversion reaction in fluoride electrodes for energy storage devices显示文摘Exploring electrochemically driven conversion reactions for the development of novel energy storage materials is an important topic as they can deliver higher energy densities than current Li-ion battery electrodes.Conversion-type fluorides promise particularly high energy densities by involving the light and small fluoride anion,and bond breaking can occur at relatively low Li activity(i.e.,high cell voltage).Cells based on such electrodes may become competitors to other envisaged alternatives such as Lisulfur or Li-air systems with their many unsolved thermodynamic and kinetic problems.Relevant conversion reactions are typically multiphase redox reactions characterized by nucleation and growth processes along with pronounced interfacial and mass transport phenomena.Hence significant overpotentials and nonequilibrium reaction pathways are involved.In this review,we summarize recent findings in terms of phase evolution phenomena and mechanistic features of(oxy)fluorides at different redox stages during the conversion process,enabled by advanced characterization technologies and simulation methods.It can be concluded that well-designed nanostructured architectures are helpful in mitigating kinetic problems such as the usually pronounced voltage hysteresis.In this context,doping and open-framework strategies are useful.By these tools,simple materials that are unable to allow for substantial Li nonstoichiometry(e.g.,by Li-insertable channels)may be turned into electroactive materials.Chilin Li Keyi Chen Xuejun Zhou Joachim Maier 2018npj Computational Materials2018,,1:8
10A new type of internal solitary waves with a re-appearance period of 23 h observed in the South China Sea显示文摘The South China Sea (SCS), in particular the northern SCS, is one of ocean areas where energetic internal solitary waves (ISWs)occur most frequently (Cai et al., 2012; Zheng, 2017). Based on the re-appearance period (RP) at an observation station, Ramp et al.(2004) divided the ISWs into two types:Type-a and Type-b. Type-a ISWs arrive regularly at the same time every day, i.e., the RP is about 24 h, and Type-b ISWs arrive about one hour late every day, i.e., the RP is about 25 h. The discovery of the Types-a and bCHEN Liang ZHENG Quanan XIONG Xuejun YUAN Yeli XIE Huarong 2018Acta Oceanologica Sinica2018,37,9:7
11Progress in research of submesoscale processes in the South China Sea显示文摘This paper overviews research progress in observation, theoretical analysis and numerical modeling of submesoscale dynamic processes in the South China Sea(SCS) particularly during recent five years. The submesoscale processes are defined according to both spatial and dynamic scales, and divided into four subcategories as submesoscale waves, submesoscale vortexes, submesoscale shelf processes, and submesoscale turbulence. The major new findings are as follows.(1) Systematic mooring observations provide new insights into the solitary waves(ISWs) and the typhoon-forced near-inertial waves(NIWs), of which a new type of ISWs with period of 23 h was observed in the northern SCS(NSCS), and the influences of background vorticity, summer monsoon onset, and deep meridional overturning circulation on the NIWs, as well as nonlinear wave-wave interaction between the NIWs and internal tides, are better understood. On the other hand, satellite altimeter sea surface height data are used to reveal the internal tide radiation patterns and provide solid evidence for that the ISWs in the northeastern SCS originate from the Luzon Strait.(2) Submesoscale offshore jets and associated vortex trains off the Vietnam coast in the western boundary of the SCS were observed from satellite chlorophyll concentration images. Spiral trains with the horizontal scale of 15–30 km and the spacing of 50–80 km were identified.(3) 3-D vertical circulation in the upwelling region east of Hainan Island was theoretically analyzed. The results show that distribution patterns of all the dynamic terms are featured by wave-like structures with horizontal wavelength scale of 20–40 km.(4) Numerical models have been used for the research of submesoscale turbulence. Submesoscale vertical pump of an anticyclonic eddy and the spatiotemporal features of submesoscale processes in the northeastern SCS are well modeled.Quanan Zheng Lingling Xie Xuejun Xiong Xiaomin Hu Liang Chen 2020Acta Oceanologica Sinica2020,39,1:7
12Pathogenic effects of biofilm with chronic pseudomonas aeruginosa lung infection in rats显示文摘Objective:To establish an animal model of P.aeruginosa biofilm associated with chronic pulmonary infection and investigate the pathogenic effects of biofilm.Methods:Experiments in vitro,measuring the MICS,MBCS of levofloxacin(LFX),ceftazidime(CAZ)in PAO579 in alginate beads and planktonic PAO579.Rats were challenged with 0.1 ml of PAO579(109CFU/ml)in alginate beads or 0.1 ml of planktonic PAO579(109 CFU/ml),3,7,14 days after challenging,bacteriological,pathological features were observed.Results:The MICS,MBCS of LFX,CAZ in PAO579 in alginate beads were higher than those in planktonic PAO579 in vitro.CFU/lung in alginate beads group was significantly higher than that in planktonic bacteria group(P = 0.002,P = 0.004,P = 0.002,respectively);macroscopic lung pathology and the inflammation in alginate beads group were significantly more severe compared to those in planktonic bacteria group in vivo.Conclusion:P.aeruginosa biofilm protected bacterium from killing of antibiotics and might mediate the host immune damage in the lung tissue and made bacterium evade the host immune defense.Ping Yan Yiqiang Chen Zhijun Song Hong Wu Jinliang Kong Xuejun Qin 2008Journal of Nanjing Medical University2008,22,1:7
13Discovery of low-mature hydrocarbon in manganese nodules and ooze from the Central Pacific deep sea floor显示文摘Extracts from manganese nodules and ooze from the Central Pacific deep sea floor were analyzed using the chromatogram-mass spectrum, and it was found that most of the biomarker molecules are of the low-mature type (some have characteristics of mature): the ratio of 'A'/C is high between 11.4%-19.75%; CPI is 1.22-1.23; C31-22S/ (22S+22R) hopane is 0.59-0.60, Tm/Ts is 0.99-1.99; pa moretane/(αβ+βα) hopane is 0.12-0.14; C29 sterane 20S/(20S+20R) is 0.35-0.41; ββ/(ββ+αα) is 0.38-0.45; arene TA(I)/TA(I+Ⅱ) is 0.16-0.21; methyl-phenanthrene index (MPI1) is 0.35-0.67. According to the geological settings of the sampling area and its organic geochemical characteristics, it is considered that the hydrothermal activities on the ocean floor facilitate the decomposition of organic matter in the sediment, which leads to the generation and migration of hydrocarbon into manganese nodules and ooze. This discovery is important for understanding the mechanisms of hydrocarbon generation in the ocean floor andHU Wenxuan JIN Zhijun YAO Suping LU Xiancai CHEN Zhilin ZHANG Linye ZHANG Xuejun ZHOU Huaiyang 2002Chinese Science Bulletin2002,47,11:7
14Microstructure Evolution and Tensile Properties of Ti_3Al/Ni-based Superalloy Welded Joint显示文摘In the present work,the dissimilar joining of a Ti_3AI-based alloy to a Ni-based superalloy was attempted by gas tungsten arc(GTA) welding technology.Sound joints were successfully achieved by using a Cu—Ni alloy as filler material.According to X-ray energy dispersive spectroscopy and X-ray diffraction analysis results three transitional layers at the weld/Ti_3AI interface were verified as follows:Ti_2AINb phase dissolved with Cu and Ni;AI(Cu,Ni)_2Ti,(Cu,Ni)_2Ti and(Nb,Ti) solid solution;Cu-rich phase and a complex multi-element phase.The In718/weld interface is characterized by solid solutions of Ni,Cu,Cr,Fe and Nb.The average tensile strength of the as-welded joints at room temperature is 1 63 MPa,and after a post—weld heat treatment it is increased slightly to 177 MPa.The fracture occurred at the surfacial layer of the joined Ti_3AI base alloy,indicating that the Ti_2AINb layer dissolved with Cu and Ni is the weak link of the Ti_3AI/ln71 8 joint.Bingqing Chen Huaping Xiong Bingbing Sun Siyi Tang Shaoqing Guo Xuejun Zhang 2014Journal of Materials Science & Technology2014,30,7:7
15First light of the 1.8-m solar telescope–CLST显示文摘Large-aperture solar telescopes play an important role in solar observations and research,and require high temporal and spatial resolution[1].To solve some fundamental problems such as the solar dynamo,coronal heating,and the triggering of major solar eruptions,the spatial resolution for solar-atmosphere observation should reach at least 0.1 arcsec[2].ChangHui Rao NaiTing Gu XueJun Rao Cheng Li LanQiang Zhang JinLong Huang Lin Kong Ming Zhang YunTao Cheng Yi Pu Hua Bao YouMing Guo YangYi Liu JinSheng Yang LiBo Zhong ChangJun Wang Kai Fang XiaoJun Zhang DongHong Chen Cheng Wang XinLong Fan ZhiWu Yan KeLe Chen XiYa Wei Lei Zhu Hong Liu YongJian Wan Hao Xian WenLi Ma 2020Science China(Physics,Mechanics & Astronomy)2020,63,10:6
16Electrochemical oxidation of recalcitrant organic compounds in biologically treated municipal solid waste leachate in a flow reactor显示文摘Biologically-treated municipal solid waste(MSW) leachate still contains many kinds of bio-recalcitrant organic matter. A new plate and frame electrochemical reactor was designed to treat these materials under flow conditions. In the electrochemical oxidation process, NH3and color could be easily removed by means of electro-generated chlorine/hypochlorite within 20 min. The efects of major process parameters on the removal of organic pollutants were investigated systematically. Under experimental conditions, the optimum operation parameters were current density of 65 mA/cm2, flow velocity of 2.6 cm/sec in electrode gap, and initial chloride ion concentration of 5000 mg/L. The COD in the leachate could be reduced below 100 mg/L after 1 hr of treatment. The kinetics and mechanism of COD removal were investigated by simultaneously monitoring the COD change and chlorine/hypochlorite production.The kinetics of COD removal exhibited a two-stage kinetic model, and the decrease of electro-generated chlorine/hypochlorite production was the major mechanism for the slowing down of the COD removal rate in the second stage. The narrowing of the electrode gap is beneficial for COD removal and energy consumption.Xuejun Quan Zhiliang Cheng Bo Chen Xincai Zhu 2013Journal of Environmental Sciences2013,25,10:6
17Pioneering function of Isl1 in the epigenetic control of cardiomyocyte cell fate显示文摘Generation of widely differing and specialized cell types from a single totipotent zygote involves large-scale transcriptional changes and chromatin reorganization. Pioneer transcription factors play key roles in programming the epigenome and facilitating recruitment of additional regulatory factors during successive cell lineage specification and differentiation steps. Here we show that Isl1 acts as a pioneer factor driving cardiomyocyte lineage commitment by shaping the chromatin landscape of cardiac progenitor cells. Using an Isl1 hypomorphic mouse line which shows congenital heart defects, genome-wide profiling of Isl1 binding together with RNA- and ATAC-sequencing of cardiac progenitor cells and their derivatives, we uncover a regulatory network downstream of Isl1 that orchestrates cardiogenesis. Mechanistically, we show that Isl1 binds to compacted chromatin and works in concert with the Brg1-Baf60c-based SWI/SNF complex to promote permissive cardiac lineage-specific alterations in the chromatin landscape not only of genes with critical functions in cardiac progenitor cells, but also of cardiomyocyte structural genes that are highly expressed when Isl1 itself is no longer present. Thus, the Isl1/Brg1-Baf60c complex plays a crucial role in orchestrating proper cardiogenesis and in establishing epigenetic memory of cardiomyocyte fate commitment.Rui Gao Xingqun Liang Sirisha Cheedipudi Julio Cordero Xue Jiang Qingquan Zhang Luca Caputo Stefan Günther Carsten Kuenne Yonggang Ren Shoumo Bhattacharya Xuejun Yuan Guillermo Barreto Yihan Chen Thomas Braun Sylvia M. Evans Yunfu Sun Gergana Dobreva 2019Cell Research2019,29,6:5
18Developing individual tree-based models for estimating aboveground biomass of five key coniferous species in China显示文摘Estimating individual tree biomass is critical to forest carbon accounting and ecosystem service modeling.In this study,we developed one-(tree diameter only) and two-variable(tree diameter and height) biomass equations,biomass conversion factor(BCF) models,and an integrated simultaneous equation system(ISES) to estimate the aboveground biomass for five conifer species in China,i.e.,Cunninghamia lanceolata(Lamb.) Hook.,Pinus massoniana Lamb.,P.yunnanensis Faranch,P.tabulaeformis Carr.and P.elliottii Engelm.,based on the field measurement data of aboveground biomass and stem volumes from 1055 destructive sample trees across the country.We found that all three methods,including the one-and two-variable equations,could adequately estimate aboveground biomass with a mean prediction error less than 5%,except for Pinus yunnanensis which yielded an error of about 6%.The BCF method was slightly poorer than the biomass equation and the ISES methods.The average coefficients of determination(R^2) were 0.944,0.938 and 0.943 and the mean prediction errors were 4.26,4.49 and 4.29% for the biomass equation method,the BCF method and the ISES method,respectively.The ISES method was the best approach for estimating aboveground biomass,which not only had high accuracy but also could estimate stocking volumes simultaneously that was compatible with aboveground biomass.In addition,we found that it is possible to develop a species-invariant one-variable allometric model for estimating aboveground biomass of all the five coniferous species.The model had an exponent parameter of 7/3 and the intercept parameter a_0 could be estimated indirectly from stem basic density(a_0= 0.294 q).Weisheng Zeng Liyong Fu Ming Xu Xuejun Wang Zhenxiong Chen Shunbin Yao 2018Journal of Forestry Research2018,29,5:5
19Bushen Qiangjin capsule(补肾强筋胶囊) inhibits the Wnt/β-catenin pathway to ameliorate papain-induced knee osteoarthritis in rats显示文摘OBJECTIVE:To evaluate the molecular mechanism underlying the beneficial effect of Bushen Qiangjin capsule(补肾强筋胶囊,BSQJ),a Traditional Chinese Medicine,on knee osteoarthritis(KOA).METHODS:In the present study,32 female Sprague-Dawley rats were randomly divided into four groups:control,KOA,high-dose BSQJ(H-BSQJ),and low-dose BSQJ(L-BSQJ).After successfully establishing the KOA model by intra-articular injection of papain,H-BSQJ and L-BSQJ groups were intragastrically administered 0.243 and 0.122 g/kg BSQJ,respectively,daily for 6 weeks.At the end of the experiment,knee articular cartilage tissues of rats were collected for evaluation by hematoxylin and eosin staining,Safranin O-Fast Green staining,and terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling assay.Serum interleukin-1βand tumor necrosis factor-αlevels of rats were detected with an enzyme-linked immunosorbent assay method.Gene expression of Wnt-4,β-catenin,Frizzled-2,glycogen synthase kinase-3β(GSK-3β),cysteinyl aspartate-specific proteinases 3 and 9(caspases 3 and 9),collagen typeⅡalpha 1(Col2 a1),and matrix metalloproteinases 1 and 13(MMP-1 and MMP-3)of rat knee articular cartilage was quantified by reverse transcription-quantitative polymerase chain reaction analysis.Wnt-4,β-catenin,Frizzled-2,GSK-3β,cleaved caspase-3,and cleaved caspase-9 protein expression in rat knee articular cartilage was determined by western blot analysis.RESULTS:BSQJ obviously reduced pathological damage and matrix degradation of articular cartilage in KOA rats.Compared with the KOA group,H-BSQJ rats exhibited downregulated m RNA and protein expression of Wnt-4,β-catenin,Frizzled-2,and caspase-3,as well as upregulated m RNA and protein expression of GSK-3β.In addition,H-BSQJ significantly increased m RNA expression of Col2 a1 and decreased m RNA expression of MMP-1 and MMP-13.CONCLUSION:BSQJ exerted a beneficial effect on KOA by a mechanism involving downregulation of the Wnt/β-catenin pathway,which inhibited both cartilage extracellular matrix degradation and chondrocyte apoptosis to ameliorate KOA in rats.YAO Nan CHEN Guocai LU Yanyan XU Xuemeng ZHAO Chuanxi HUANG Xuejun LIU Wengang PENG Sha WU Huai 2021Journal of Traditional Chinese Medicine2021,41,6:5
20A Formation Reconfiguration Algorithm for Multi-UAVs Based on Distributed Cooperative Coevolutionary with an Adaptive Grouping Strategy显示文摘The Formation reconfiguration problem plays a crucial role in the implementation of complex t asks for multiple unmanned aerial vehicles,which attracted increasing attention in the past decade.Taking into consideration the control parame ters and time discretization of the multi-UAVs in the 3 Dimensional(3-D)space,the formation reconfiguration problem can be formulated as a large-scale combinatorial optimization problem with complex constraints and tight couplings between variables.The problem results in the reduction in efficiency and effectiveness using classic bio-inspired algorithms.In this paper,a formation reconfiguration method based on cooperative coevolutionary algorithm is proposed along with a new decomposition strategy to improve the optimization capability and prevent premature convergence.In the proposed approach,variables of multi-UAV are divided into several sub-groups based on an adaptive grouping strategy.The proposed strategy groups the variables in order to better deal with the tight coupling among them,taking into account the variables'variance and multi-UAVs characteristics of the formation reconfiguration problem.Therefore,each sub・group can adopt the Self-adaptive differential evolution strategy with neighborhood search(SaNSDE)with the aim to optimize the UAV's control inputs using multithreaded programming.SaNSDE contributes to calculating the results in a fully distributed and paralleled manner.Optimal solution is then obtained through cooperation and coordina tion with all subcomponents.Simulation results based on extreme scenarios adopted by previous researches demonstrate that the proposed algorithm out performed the existing approaches including Par ti cle swarm optimization(PSO),Differential evolution(DE),and the cooperative coevolution algorithms with different well-known grouping strategies.LIU Huaxian LIU Feng ZHANG Xuejun GUAN Xiangmin CHEN Jun 2020Chinese Journal of Electronics2020,29,5:5
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