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Global dynamics analysis for a nonlinear HTLV-I model with logistic proliferation and CTL response

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International Journal of Biomathematics 2024年第3期17卷 35-55页

作者： Siyu chen zhijun Liu Lianwen Wang Xingan Zhang School of Mathematics and Statistics Central China Normal University Wuhan Hubei 430079P.R.China School of Mathematics and Statistics Hubei Minzu University Enshi Hubei 445000P.R.China

It is beyond dispute that cytotoxic T-lymphocytes(CTLs)exert a vital function in the host's antiviral defense mechanism.With the idea of the above factor and the logistic proliferation of CD4+T-cells,we establish a HTLV-I(human T-cell leukemia virus type-I)mathematical model.First,two threshold parameters Ro and Re(the basic reproduction numbers for viral infection and CTL immune response,respectively)are obtained.Second,sufficient criteria for local and global asymptotic stabilities of the feasible equilibria of the model are deduced,respectively.Third,the sensitivity analyses of Ro and Rc are performed to better understand the effective strategies for HTLV-I infection.Finally,not only numerical simulations are given to illustrate the stability conclusions,but also the biological significance is stated.

关键词： HTLV-I infection logistic proliferation CTL response stability sensitivity analysis

Pathological progression of osteoarthritis:a perspective on subchondral bone

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Frontiers of Medicine 2024年第2期18卷 237-257页

作者： Xuefei Li Wenhua chen Dan Liu Pinghua chen Shiyun Wang Fangfang Li Qian chen Shunyi Lv Fangyu Li chen chen Suxia Guo Weina Yuan Pan Li zhijun Hu Longhua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine Shanghai200032China Research and Development Center of Chinese Medicine Resources and Biotechnology Shanghai University of Traditional Chinese MedicineShanghai201203China

Osteoarthritis(OA)is a degenerative bone disease associated with aging.The rising global aging population has led to a surge in OA cases,thereby imposing a significant socioeconomic burden.Researchers have been keenly investigating the mechanisms underlying OA.Previous studies have suggested that the disease starts with synovial inflammation and hyperplasia,advancing toward cartilage degradation.Ultimately,subchondral-bone collapse,sclerosis,and osteophyte formation occur.This progression is deemed as“top to bottom.”However,recent research is challenging this perspective by indicating that initial changes occur in subchondral bone,precipitating cartilage breakdown.In this review,we elucidate the epidemiology of OA and present an in-depth overview of the subchondral bone’s physiological state,functions,and the varied pathological shifts during OA progression.We also introduce the role of multifunctional signal pathways(including osteoprotegerin(OPG)/receptor activator of nuclear factor-kappa B ligand(RANKL)/receptor activator of nuclear factor-kappa B(RANK),and chemokine(CXC motif)ligand 12(CXCL12)/CXC motif chemokine receptor 4(CXCR4))in the pathology of subchondral bone and their role in the“bottom-up”progression of OA.Using vivid pattern maps and clinical images,this review highlights the crucial role of subchondral bone in driving OA progression,illuminating its interplay with the condition.

关键词： osteoarthritis subchondral bone OPG/RANKL/RANK CXCL12/CXCR4

Phosphate-Bismuthate Glass and Fiber with Heavy Doping of Silver Nanoparticles(Invited)

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激光与光电子学进展 2024年第3期61卷 168-177页

作者： chen Fuguang Jiang Bofan chen Zhi Ma Siyuan Huang Yupeng Zhang Hang Ma zhijun Research Center for Humanoid Sensing Zhejiang LabHangzhou 311121ZhejiangChina State Key Laboratory of Luminescent Materials and Devices School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510641GuangdongChina Laboratory for Shock Wave and Detonation Physics Research Institute of Fluid PhysicsChina Academy of Engineering PhysicsMianyang 621900SichuanChina

Glass with heavy doping of noble metal nanoparticles is expected to exhibit high optical nonlinearity.In this study,the effects of glass composition,structure,and heat treatment on the formation of silver nanoparticles(Ag NPs)in phosphate-bismuthate(PB)glass are investigated.By optimizing the chemical composition and preparation parameters,strong localized surface plasmon resonance is achieved in the PB glass with a silver mass fraction of more than 13%,which is 20 and 6 times higher than that in bismuthate and phosphate glasses reported previously,respectively.The high solubility of the phosphate component and the self-reduction effect of the bismuthate component jointly contributed to the stability and high content of Ag NPs in the PB glass.Z-scan measurements show that such heavy doping PB glass has a reverse saturable absorption coefficient of-14×10^(-12)m·W^(-1)and a saturable absorption coefficient of 4.94×10^(-12)m·W^(-1)at 800 nm.Furthermore,the heavy doping PB glass exhibits excellent thermal stability,making it promising for the fabrication of nonlinear optical fibers.In addition,with a heavily silver-doped PB glass rod as the core and a commercial silicate glass tube as the cladding,a composite glass fiber with high Ag-NP doping is successfully fabricated using a“molten-core”fiber drawing method.

关键词： phosphate-bismuthate glass silver nanoparticle optical nonlinearity molten-core fiber drawing

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Long non-coding RNA H19 regulates neurogenesis of induced neural stem cells in a mouse model of closed head injury

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Neural Regeneration Research 2024年第4期19卷 872-880页

作者： Mou Gao Qin Dong zhijun Yang Dan Zou Yajuan Han Zhanfeng chen Ruxiang Xu Department of Neurosurgery Sichuan Academy of Medical Sciences and Sichuan Provincial People's HospitalSchool of MedicineUniversity of Electronic Science and Technology of China Department of Neurosurgery Chinese PLA General Hospital Zhongsai Stem Cell Genetic Engineering Co. Ltd. Department of Neurology Fu Xing HospitalCapital Medical University

Stem cell-based therapies have been proposed as a potential treatment for neural regeneration following closed head injury.We previously reported that induced neural stem cells exert beneficial effects on neural regeneration via cell replacement.However,the neural regeneration efficiency of induced neural stem cells remains limited.In this study,we explored differentially expressed genes and long non-coding RNAs to clarify the mechanism underlying the neurogenesis of induced neural stem cells.We found that H19 was the most downregulated neurogenesis-associated lnc RNA in induced neural stem cells compared with induced pluripotent stem cells.Additionally,we demonstrated that H19 levels in induced neural stem cells were markedly lower than those in induced pluripotent stem cells and were substantially higher than those in induced neural stem cell-derived neurons.We predicted the target genes of H19 and discovered that H19 directly interacts with mi R-325-3p,which directly interacts with Ctbp2 in induced pluripotent stem cells and induced neural stem cells.Silencing H19 or Ctbp2 impaired induced neural stem cell proliferation,and mi R-325-3p suppression restored the effect of H19 inhibition but not the effect of Ctbp2 inhibition.Furthermore,H19 silencing substantially promoted the neural differentiation of induced neural stem cells and did not induce apoptosis of induced neural stem cells.Notably,silencing H19 in induced neural stem cell grafts markedly accelerated the neurological recovery of closed head injury mice.Our results reveal that H19 regulates the neurogenesis of induced neural stem cells.H19 inhibition may promote the neural differentiation of induced neural stem cells,which is closely associated with neurological recovery following closed head injury.

关键词： closed head injury Ctbp2 induced neural stem cell lncRNA H19 miR-325-3p neurogenesis

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A facile strategy for large-scale production of 2D nanosheets exfoliated by three-roll milling

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Journal of Advanced Ceramics 2024年第1期13卷 11-18页

作者： Xin Wang Yang Xia Juntong Huang Yao Su Zhi chen Linlin chen Zhaohui Wu zhijun Feng Huiyong Yang Xibao Li School of Materials Science and Engineering Nanchang Hangkong UniversityNanchang 330063China

Two-dimensional(2D)nanomaterials,such as graphene,MoS_(2),and MAX,have attracted increasing research attention in recent years due to their unique structural and performance advantages.However,their complex production processes and equipment requirements are significant issues affecting their widespread use.Here,with an exfoliation strategy using three-roll milling,we present a simple,cost-effective,and extensible method to produce multilayer graphene,BN,MoS_(2),and Ti_(3)AlC_(2) nanosheets.The roller and phenolic resin created three kinds of forces on the layered 2D materials,i.e.,shear forces,compressive forces,and adhesive forces,which exfoliated layered materials from their edges and surfaces into nanosheets.Subsequently,the exfoliated materials were ultrasonically washed with alcohol,treated with ultrasonic vibration,and centrifuged to obtain 2D nanomaterials.The easy operation and high yield are attractive for research based on the construction of high-performance 2D nanosheet-based devices at low cost.Herein,the obtained multilayer graphene and MoS_(2) nanosheets were used as anode materials of sodium/potassium-ion batteries,respectively,to test their electrochemical properties.Better performances are obtained compared with their primary bulk materials.

关键词： two-dimensional(2D)nanosheets exfoliation three-roll milling(TRM) sodium/potassium-ion batteries

Kinematic Calibration of a Six-Legged Walking Machine Tool

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Chinese Journal of Mechanical Engineering 2022年第2期35卷 28-44页

作者： Jimu Liu zhijun chen Feng Gao State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

This paper presents the kinematic calibration of a novel six-legged walking machine tool comprising a six-legged mobile robot integrated with a parallel manipulator on the body.Each leg of the robot is a 2-universal-prismatic-spherical(UPS)and UP parallel mechanism,and the manipulator is a 6-PSU parallel mechanism.The error models of both subsystems are derived according to their inverse kinematics.The objective function for each kinematic limb is formulated as the inverse kinematic residual,i.e.,the deviation between the actual and computed joint coordinates.The hip center of each leg is first identified via sphere fitting,and the other kinematic parameters are identified by solving the objective function for each limb individually using the least-squares method.Thus,the kinematic parameters are partially decoupled,and the complexities of the error models are reduced.A calibration method is proposed for the legged robot to overcome the lack of a fixed base on the ground.A calibration experiment is conducted to validate the proposed method,where a laser tracker is used as the measurement equipment.The kinematic parameters of the entire robot are identified,and the motion accuracy of each leg and that of the manipulator are significantly improved after calibration.Validation experiments are performed to evaluate the positioning and trajectory errors of the six-legged walking machine tool.The results indicate that the kinematic calibration of the legs and manipulator improves not only the motion accuracy of each individual subsystem but also the cooperative motion accuracy among the subsystems.

关键词： Parallel mechanism Legged robot Kinematic calibration

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How neonatal diet affects the long-term development of rumination behavior, rumen fermentation and feed digestion in dairy calves fed a high milk level?

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Animal Nutrition 2024年第1期16卷 326-337页

作者： Jianxin Xiao Tianyu chen Rong Peng Gibson M. Alugongo Hui Yang Shuai Liu Yulin Ma Jingjun Wang Shengli Li zhijun Cao State Key Laboratory of Animal Nutrition and Feeding International Calf and Heifer Organization College of Animal Science and Technology China Agricultural University Key Laboratory of Low Carbon Culture and Safety Production in Cattle in Sichuan Animal Nutrition Institute Sichuan Agricultural University

This study was to investigate growth performance, rumination development, rumen fermentation and feed digestion in young calves provided high volumes(about 20% of calf birth weight) of milk with or without forage inclusion and how these parameters correlate with each other. Immediately after birth,160 newborn Holstein female calves(41.6 ± 4.2 kg of initial BW) were randomly divided into 2 treatments: 1) starter(CON, only starter) and 2) starter and hay(HAY, both starter and hay). The calves were fed their respective experimental diets from d 4 to 84, after which they were all introduced to similar diets until the end of the experiment on d 196. Treatment had no effect on growth and structural measurements throughout the experimental period. However, treatment had an effect on the other parameters, mainly during the post-weaning period. Forage supplementation tended to reduce starter dry matter intake(P = 0.05), while increasing the forage intake(P < 0.01) and the feed-to-gain ratio(P < 0.01). HAY calves had increased neutral detergent fiber(NDF) and physically effective NDF(peNDF)intakes(P < 0.05) and tended to lower(P < 0.01) starch intake compared to CON calves. The HAY calves had a higher rumination time(P < 0.01), ruminal pH(P < 0.01), and acetate-to-propionate ratio(P = 0.05)compared to the CON calves. Spearman correlation analysis showed that rumination time was positively related to the ruminal p H at d 84(P = 0.01) and 196(P = 0.02). The HAY calves had similar apparent total-tract digestibility of dry matter(DM), NDF and ether extract(EE), but lower digestibility of organic matter(OM, P = 0.03), crude protein(CP, P < 0.01) and starch(P < 0.01) compared to those of the CON calves at week 12. Furthermore, there were no positive relationships between rumination time and nutrient digestibility or between rumination time per kilogram DM and nutrient digestibility. In conclusion, feeding hay to calves fed a high milk level improved rumination during the post-weaning period only, without a concomitant effect on

关键词： Neonatal calf Early forage feeding Rumination Rumen fermentation Nutrient digestibility

Construction of a cement-rebar nanoarchitecture for a solution-processed and flexible film of a Bi_(2)Te_(3)/CNT hybrid toward low thermal conductivity and high thermoelectric performance

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Carbon Energy 2022年第1期4卷 115-128页

作者： zhijun chen Haicai Lv Qichun Zhang Hanfu Wang Guangming chen College of Materials Science and Engineering Shenzhen UniversityShenzhenChina College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhenChina Department of Materials Science and Engineering City University of Hong KongHong KongChina Center of Super-Diamond and Advanced Films(COSDAF) City University of Hong KongHong KongChina National Center for Nanoscience and Technology BeijingChina

Solution processability and flexibility still remain major challenges for many thermoelectric(TE)materials,including bismuth telluride(Bi_(2)Te_(3)),a typical and commercially available TE material.Here,we report a new solutionprocessed method to prepare a flexible film of a Bi_(2)Te_(3)/single-walled carbon nanotube(SWCNT)hybrid,where the dissolved Bi_(2)Te_(3) ion precursors are mixed with dispersed SWCNTs in solution and recrystallized on the SWCNT surfaces to form a“cement-rebar”-like architecture.The hybrid film shows an n-type characteristic,with a stable Seebeck coefficient of^(−1)00.00±1.69μVK^(−1) in air.Furthermore,an extremely low in-plane thermal conductivity of∼0.33Wm^(−1) K^(−1) is achieved at 300 K,and the figure of merit(ZT)reaches 0.47±0.02.In addition,the TE performance is independent of mechanical bending.The unique“cement-rebar”-like architecture is believed to be responsible for the excellent TE performances and the high flexibility.The results provide a new avenue for the fabrication of solution-processable and flexible TE hybrid films and will speed up the applications of flexible electronics and energy conversion.

关键词： Bi_(2)Te_(3) carbon nanotube hybrid solution-processed thermoelectrics

A Novel Method to Enhance the Inversion Speed and Precision of the NMR T_(2) Spectrum by the TSVD Based Linearized Bregman Iteration

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Computer Modeling in Engineering & Sciences 2023年第9期136卷 2451-2463页

作者： Yiguo chen Congjun Feng Yonghong He zhijun chen Xiaowei Fan Chao Wang Xinmin Ge State Key Laboratory of Continental Dynamics Northwest UniversityXi’an710069China Department of Geology Northwest UniversityXi’an710069China Reseach Institute of Shaanxi Yanchang Petroleum(Group)Co. Ltd.Xi’an710075China School of Geosciences China University of PetroleumQingdao266580China

The low-field nuclear magnetic resonance(NMR)technique has been used to probe the pore size distribution and the fluid composition in geophysical prospecting and related fields.However,the speed and accuracy of the existing numerical inversion methods are still challenging due to the ill-posed nature of the first kind Fredholm integral equation and the contamination of the noises.This paper proposes a novel inversion algorithmto accelerate the convergence and enhance the precision using empirical truncated singular value decompositions(TSVD)and the linearized Bregman iteration.The L1 penalty term is applied to construct the objective function,and then the linearized Bregman iteration is utilized to obtain fast convergence.To reduce the complexity of the computation,empirical TSVD is proposed to compress the kernel matrix and determine the appropriate truncated position.This novel inversion method is validated using numerical simulations.The results indicate that the proposed novel method is significantly efficient and can achieve quick and effective data solutions with low signal-to-noise ratios.

关键词： Low field nuclear magnetic resonance linearized bregman iteration truncated singular value decomposition numerical simulations