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Role of inactivated SARS-CoV-2 vaccine induced T cell responses in ameliorating COVID-19 severity

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Virologica Sinica 2023年第2期38卷 324-326页

作者： Hongming Huang Jia liu Department of Infectious Diseases Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Joint International Laboratory of Infection and Immunity Huazhong University of Science and TechnologyWuhan430022China

The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)vaccine is one of the most effective weapons to fight the coronavirus disease 2019(COVID-19)pandemic(Lazarus et al.,2022).Among all SARS-CoV-2 vaccines generated on different platforms,those consisting of the inactivated virus,such as BBIBP-CorV and CoronaVac,have been frequently used(WHO,2023).By January 30,2023,92.9%of the entire,all-ages population had initiated vaccination and 90.6%had completed their primary series based on the whole population size reported in the seventh census of Chinese mainland(China CDC,2023).However,compared to SARS-CoV-2 mRNA vaccines,which can elicit extremely high quantities of anti-spike(S)antibodies,the levels of neutralizing antibodies induced by inactivated SARS-CoV-2 vaccines are quite lower and wane quickly(Peng et al.,2022;Lim et al.,2021).

关键词： vaccine severity acute

Photoaging mechanism of microplastics:a perspective on the effect of dissolved organic matter in natural water

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Frontiers of Environmental Science & Engineering 2023年第11期17卷 287-293页

作者： Ying Yu Xinna liu Yong liu Jia liu Yang Li College of Arts and Sciences Northeast Agricultural UniversityHarbin 150030China Key Laboratory of Water and Sediment Sciences of Ministry of Education State Key Laboratory of Water Environment SimulationSchool of EnvironmentBeijing Normal UniversityBeijing 100875China Institutional Center for Shared Technologies and Facilities Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing100101 China Institute of Analysis and Testing Beijing Academy of Science and TechnologyBeijing Center for Physical&Chemical AnalysisBeijing 100089China

Plastic products widespread in natural water can be broken into smaller-sized microplastics(MPs,<5 mm)under light irradiation,thermal degradation and biodegradation,posing a serious threat to aquatic ecosystems and human health.This perspective concludes that MPs can generate reactive oxygen species(ROS)through initiation,propagation and termination steps,which can attack the polymer resulting in the photoaging and breakdown of C–C and C–H bonds under ultraviolet(UV)irradiation.Free radical generation and weathering degree of MPs depend on their physicochemical properties and environmental conditions.In general,UV irradiation and co-existed MPs can significantly accelerate MP photoaging.With plentiful chromophores carbonyl,carboxyl and benzene rings,Dissolved organic matter(DOM)mainly absorbs photons(300–500 nm)and generates hydrated electrons,^(3)DOM^(*) and ROS,which may affect MP photoaging.However,whether DOM may transfer the electron and energy to MPs under UV irradiation,affect ROS generation of MPs and their photoaging pathway are inadequately studied.More studies are needed to elucidate MP photoaging pathways and mechanisms,consider the influence of stabilization capacity,photosensitization and photoionization of DOM as well as their competitive light absorption with MPs,which provides valuable insights into the environmental behavior and ecological risk of MPs in natural water.

关键词： Microplastics Photoaging Dissolved organic matter ROS generation

Design and optimization of electrolyte flow fields in electrochemical machining of cross-channel array with tool vibration

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Chinese Journal of Aeronautics 2022年第4期35卷 461-472页

作者： Yan liu Jia liu Di ZHU Hao WANG College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

A metallic interconnect plate with a flow channel array is one of the most important elements in a solid oxide fuel cell(SOFC). Electrochemical machining(ECM) is considered to be an adoptable technology for fabricating flow channels in an interconnect plate on account of its efficiency and low cost. With respect to the traditional electrolyte flow mode in ECM cross-channel array, the electrolyte usually flows from one side to the opposite side of the rectangular processing area. However, obvious flow marks are typically formed at the bottom of channels perpendicular to the flow. According to multiphysical simulation analysis, the low electrolyte velocity in the channels perpendicular to the flow leads to uneven distribution of electrolyte products. To improve the uniformity of the flow field, two new electrolyte flow modes, “two-in and two-out” and “three-in and one-out”, are proposed. By adding one or two additional electrolyte inlets to the sides of the traditional flow field, the electrolyte flow velocity in the channels perpendicular to the traditional flow will be increased. Corresponding simulations and experiments were performed and the results showed that the “three-in and one-out” flow mode can produce a flatter bottom surface for the cross-channel array. Parameter optimization experiments for the preferred flow mode were undertaken and the optimal flow field parameters were determined.

关键词： Cross-channel array Dynamic simulation Electrochemical machining Flow field Interconnect plate

Fast-Converging and Asymptotic-Preserving Simulation of Frequency Domain Thermoreflectance

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Communications in Computational Physics 2023年第6期33卷 65-93页

作者： Jia liu Lei Wu Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhen 518055P.R.China

The heat conduction under fast external excitation exists in many experiments measuring the thermal conductivity in solids,which is described by the phonon Boltzmann equation,i.e.,the Callaway’s model with dual relaxation times.Such a kinetic system has two spatial Knudsen numbers related to the resistive and normal scatterings,and one temporal Knudsen number determined by the external oscillation frequency.Thus,it is a challenge to develop an efficient numerical method.Here we first propose the general synthetic iterative scheme(GSIS)to solve the phonon Boltzmann equation,with the fast-converging and asymptotic-preserving properties:(i)the solution can be found within dozens of iterations for a wide range of Knudsen numbers and frequencies,and(ii)the solution is accurate when the spatial cell size in the bulk region is much larger than the phonon mean free path.Then,we investigate how the heating frequency affects the heat conduction in different transport regimes.

关键词： Frequency domain thermoreflectance phonon Boltzmann equation general synthetic iterative scheme

A novel pulmonary fibrosis murine model with immune-related liver injury

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Animal Models and Experimental Medicine 2023年第3期6卷 274-282页

作者： Kexin jia jianzhi Wu Yijie Li Jia liu Runping liu Yajie Cai Yinhao Zhang Xiaojiaoyang Li School of Life Sciences Beijing University of Chinese MedicineBeijingChina School of Chinese Materia Medica Beijing University of Chinese MedicineBeijingChina

Idiopathic pulmonary fibrosis(IPF),characterized by aggravated alveolar destruc-tion and fibrotic matrix deposition,tendentiously experiences the stage called acute exacerbation IPF(AE-IPF)and progresses to multiple organ damage,especially liver injury.Recent studies have found a variety of immune microenvironment disorders associated with elevated IPF risk and secondary organ injury,whereas current animal models induced with bleomycin(BLM)could not completely reflect the pathologi-cal manifestations of AE-IPF patients in clinic,and the exact underlying mechanisms are not yet fully explored.In the current study,we established an AE-IPF model by tracheal administration of a single dose of BLM and then repeated administrations of lipopolysaccharide in mice.This mouse model successfully recapitulated the clinical features of AE-IPF,including excessive intrapulmonary inflammation and fibrosis and extrapulmonary manifestations,as indicated by significant upregulation of Il6,Tnfa,Il1b,Tgfb,fibronectin,and Col1a1 in both lungs and liver and elevated serum aspartate transaminase and alanine transaminase levels.These effects might be attributed to the regulation of Th17 cells.By sharing this novel murine model,we expect to pro-vide an appropriate experimental platform to investigate the pathogenesis of AE-IPF coupled with liver injury and contribute to the discovery and development of targeted interventions.

关键词： bleomycin idiopathic pulmonary fibrosis lipopolysaccharide liver injury murine model

Qualitative analysis of a diffusive predator–prey model with Allee and fear effects

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International Journal of Biomathematics 2021年第6期14卷 1-31页

作者： Jia liu jiangsu Vocational College of Electronics and Information Huaian 223003 P.R.China

In this study,we consider a diffusive predator-prey model with multiple Allee effects induced by fear factors.We investigate the existence,boundedness and permanence of the solution of the system.We also discuss the existence and non-existence of non-constant solutions.We derive sufficient conditions for spatially homogeneous(non-homogenous)Hopf bifurcation and steady state bifurcation.Theoretical and numerical simulations show that strong Allee effect and fear effect have great effect on the dynamics of system.

关键词： Predator-prey diffusion fear effect Allee effect bifurcation

Design method and experimental study of a cathode tool with an extremely high leveling ratio for electrochemical machining of blisk

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Chinese Journal of Aeronautics 2024年第4期37卷 593-608页

作者： Moqi SHEN Jia liu Jingtao WANG Di ZHU College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

To obtain final parts with the desired dimensional accuracy and repeatability via electrochemical machining(ECM), the machining process must enter an ECM balanced state. However,for the ECM processing of blisk, a key component of aerospace engines, the surface of the blade blank often has an uneven allowance distribution due to the narrow passage of the cascade. It is difficult to remedy this issue in subsequent processing steps, which is necessary to ensure the dimensional accuracy and repeatability of the final blade profile. To solve this problem, electrolytic machining must be preceded by electrolytic shaping, which requires cathode tools with large leveling ratios to quickly homogenize the blank surface of the blade. In this study, to obtain a cathode tool with an extremely high leveling ratio, a design method based on the variation in the electrode gap in the non-equilibrium electrolytic state is proposed, and a dissolution model based on the nonequilibrium state is established. In this design method, the allowance on the blank to be machined is first divided into many discrete allowances with the normal direction. The initial machining clearance, feed rate, and total machining time are then calculated using classical ECM equilibrium state theory based on the maximum allowance. Meanwhile, the point coordinates of the cathode tool at maximum allowance can be determined. The non-equilibrium model can then be used to calculate the relative coordinate positions corresponding to the remaining discrete allowances. Finally, the entire cathode tool profile is designed. Simulations, fundamental experiments, and blisk unit workpiece experiments were carried out to validate the design approach. In the simulated processing of the plane workpiece, the leveling ratio of the cathode tool designed by the proposed method(0.77)was 83% higher than that of the cathode tool designed using the traditional method. The simulation results were confirmed by processing experiments. In the machining of blisk unit workpieces with compl

关键词： Electrochemical machining(ECM) Non-equilibrium machining Large leveling ratios Cathode design Finite element simulation Blisk

Comparison of electrochemical behaviors of Ti-5Al-2Sn-4Zr-4Mo-2Cr-1Fe and Ti-6Al-4V titanium alloys in NaNO_(3) solution

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 750-763页

作者： Jia liu Shuanglu Duan Xiaokang Yue Ningsong Qu College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The Ti-5Al-2Sn-4Zr-4Mo-2Cr-1Fe(β-CEZ)alloy is considered as a potential structural material in the aviation industry due to its outstanding strength and corrosion resistance.Electrochemical machining(ECM)is an efficient and low-cost technology for manufacturing theβ-CEZ alloy.In ECM,the machining parameter selection and tool design are based on the electrochemical dissolution behavior of the materials.In this study,the electrochemical dissolution behaviors of theβ-CEZ and Ti-6Al-4V(TC4)alloys in NaNO3solution are discussed.The open circuit potential(OCP),Tafel polarization,potentiodynamic polarization,electrochemical impedance spectroscopy(EIS),and current efficiency curves of theβ-CEZ and TC4 alloys are analyzed.The results show that,compared to the TC4 alloy,the passivation film structure is denser and the charge transfer resistance in the dissolution process is greater for theβ-CEZ alloy.Moreover,the dissolved surface morphology of the two titanium-based alloys under different current densities are analyzed.Under low current densities,theβ-CEZ alloy surface comprises dissolution pits and dissolved products,while the TC4 alloy surface comprises a porous honeycomb structure.Under high current densities,the surface waviness of both the alloys improves and the TC4 alloy surface is flatter and smoother than theβ-CEZ alloy surface.Finally,the electrochemical dissolution models ofβ-CEZ and TC4 alloys are proposed.

关键词： electrochemical machining dissolution behavior β-CEZ titanium alloy polarization curve current efficiency

Event-triggered dynamic output-feedback control for a class of Lipschitz nonlinear systems

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Frontiers of Information Technology & Electronic Engineering 2022年第11期23卷 1684-1699页

作者： Zhiqian liu Xuyang LOU jia jia jia Key Laboratory of Advanced Process Control for Light Industry(Ministry of Education) Jiangnan UniversityWuxi 214122China

This paper investigates the problem of dynamic output-feedback control for a class of Lipschitz nonlinear systems.First,a continuous-time controller is constructed and sufficient conditions for stability of the nonlinear systems are presented.Then,a novel event-triggered mechanism is proposed for the Lipschitz nonlinear systems in which new event-triggered conditions are introduced.Consequently,a closed-loop hybrid system is obtained using the event-triggered control strategy.Sufficient conditions for stability of the closed-loop system are established in the framework of hybrid systems.In addition,an upper bound of a minimum inter-event interval is provided to avoid the Zeno phenomenon.Finally,numerical examples of a neural network system and a genetic regulatory network system are provided to verify the theoretical results and to show the superiority of the proposed method.

关键词： Lipschitz nonlinear system Dynamic output-feedback control Event-triggered control Global asymptotic stability