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Regular Global Attractors of Type Ⅲ Thermoelastic Extensible Beams

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Chinese Annals of Mathematics,Series B 2010年第5期31卷 619-630页

作者： Michele COTI ZELATI Vittorino PATA ramon Quintanilla Mathematics Department Indiana UniversityRawles Hall Dipartimento di Matematica "F. Brioschi" Politecnico di Milano Matemtica Aplicada 2 ETSEIAT-UPC Terrassa

For β∈ R,the authors consider the evolution system in the unknown variables u and ααttu+αxxxxu+αxxtα-(β+αxu L22)αxxu=f,αttα-αxxα-αxxtα-αxxtu=0 describing the dynamics of type III thermoelastic extensible beams,where the dissipation is entirely contributed by the second equation ruling the evolution of the thermal displacement α.Under natural boundary conditions,the existence of the global attractor of optimal regularity for the related dynamical system acting on the phase space of weak energy solutions is established.

关键词：弹性梁热弹性 Ⅲ型自然边界条件进化系统动态扩展 III 热位移

A higher-order porous thermoelastic problem with microtemperatures

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Applied Mathematics and Mechanics(English Edition) 2023年第11期44卷 1911-1926页

作者： J.R.FERNáNDEZ R.quintanilla Department of Applied Mathematics I University of VigoETSI de Telecomunicacion Campus As Lagoas Marcosende s/nVigo 36310Spain Department of Mathematics Polytechnical University of CatalunyaTerrassa 08222BarcelonaSpain

In this paper,we study a porous thermoelastic problem with microtemperatures assuming parabolic higher order in time derivatives for the thermal variables.The model is derived and written as a coupled linear system.Then,a uniqueness result is proved by using the logarithmic convexity method in the case that we do not assume that the mechanical energy is positive definite.Finally,the existence of the solution is obtained by introducing an energy function and applying the theory of linear semigroups.

关键词： higher order thermoelasticity microtemperature logarithmic convexity method existence and uniqueness

A role for the Tgf-β/Bmp co-receptor Endoglin in the molecular oscillator that regulates the hair follicle cycle

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Journal of Molecular Cell Biology 2019年第1期11卷 39-52页

作者： Maria I.Calvo-Sanchez Sandra Fernandez-Martos Elisa Carrasco Gema Moreno-Bueno Carmelo Bernabeu Miguel quintanilla Jesus Espada Instituto de Investigaciones Biomedicas'Alberto Sols' Consejo Superior de Investigaciones Cientificas(CSIC)-Departamento de BioqufmicaUniversidad Autonoma de Madrid(UAM)Madrid 28029Spain Instituto de Investigaciones Biosanitarias Facultad de Ciencias ExperimentalesUniversidad Francisco de Vitoria(UFV)Pozuelo de Alarcon 28223Spain Centro de Investigacion Biomedica en Red de Cancer(CIBERONC) Spain Centro de Investigaciones Biologicas Consejo Superior de Investigaciones Cientificas(CSIC)and Centro de Investigacion Biomedica en Red de Enfermedades Raras(CIBERER)Madrid 28040Spain Centro Integrativo de Biologfa y Quimica Aplicada Universidad Bernardo O'HigginsSantiago 8370854Chile Instituto ramon y Cajal de Investigacion Sanitaria(IRYCIS) Hospital Universitario Ramon y CajalMadridSpain

The hair follicle is a biological oscillator that alternates growth,regression,and rest phases driven by the sequential activation of the proliferation differentiation programs of resident stem cell populations.The activation of hair follicle stem cell niches and subsequent entry into the growing phase is mainly regulated by Wnt/β-catenin signalling,while regression and resting phases are mainly regulated by Tgf-β/Bmp/Smad activity.A major question still unresolved is the nature of the molecular switch that dictates the coordinated transition between both signalling pathways.Here we have focused on the role of Endoglin(Eng),a key co-receptor for members of the Tgf-β/Bmp family of growth factors.Using an Eng haploinsufficient mouse model,we report that Eng is required to maintain a correct follicle cycling pattern and for an adequate stimulation of hair follicle stem cell niches.We further report thatβ-catenin binds to the Eng promoter depending on Bmp signalling.Moreover,we show thatβ-catenin interacts with Smad4 in a Bmp/Eng-dependent context and both proteins act synergistically to activate Eng promoter transcription.These observations point to the existence of a growth/rest switching mechanism in the hair follicle that is based on an Eng-dependent feedback cross-talk between Wnt/β-catenin and Bmp/Smad signals.

关键词： Endoglin hair follicle skin stem cells Wnt/β-catenin Tgf-β/Bmp/Smad

The use of fibroblasts as a valuable strategy for studying mitochondrial impairment in neurological disorders

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Translational Neurodegeneration 2022年第1期11卷 401-425页

作者： Margrethe A.Olesen Francisca Villavicencio-Tejo Rodrigo A.quintanilla Laboratory of Neurodegenerative Diseases Facultad de Ciencias de La SaludInstituto de Ciencias BiomédicasUniversidad Autónoma de ChileSantiagoChile

Neurological disorders(NDs)are characterized by progressive neuronal dysfunction leading to synaptic failure,cognitive impairment,and motor injury.Among these diseases,Alzheimer’s disease(AD),Parkinson’s disease(PD),Huntington’s disease(HD),and amyotrophic lateral sclerosis(ALS)have raised a significant research interest.These disorders present common neuropathological signs,including neuronal dysfunction,protein accumulation,oxidative damage,and mitochondrial abnormalities.In this context,mitochondrial impairment is characterized by a deficiency in ATP production,excessive production of reactive oxygen species,calcium dysregulation,mitochondrial transport failure,and mitochondrial dynamics deficiencies.These defects in mitochondrial health could compromise the synaptic process,leading to early cognitive dysfunction observed in these NDs.Interestingly,skin fibroblasts from AD,PD,HD,and ALS patients have been suggested as a useful strategy to investigate and detect early mitochondrial abnormalities in these NDs.In this context,fibroblasts are considered a viable model for studying neurodegenerative changes due to their metabolic and biochemical relationships with neurons.Also,studies of our group and others have shown impairment of mitochondrial bioenergetics in fibroblasts from patients diagnosed with sporadic and genetic forms of AD,PD,HD,and ALS.Interestingly,these mitochondrial abnormalities have been observed in the brain tissues of patients suffering from the same pathologies.Therefore,fibroblasts represent a novel strategy to study the genesis and progression of mitochondrial dysfunction in AD,PD,HD,and ALS.This review discusses recent evidence that proposes fibroblasts as a potential target to study mitochondrial bioenergetics impairment in neurological disorders and consequently to search for new biomarkers of neurodegeneration.

关键词： Mitochondria Fibroblasts Cell reprogramming Alzheimer’s disease Parkinson’s disease Huntington’s disease Amyotrophic lateral sclerosis Mitochondrial dysfunction

Moore-Gibson-Thompson theory for thermoelastic dielectrics

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Applied Mathematics and Mechanics(English Edition) 2021年第2期42卷 309-316页

作者： J.R.FERNANDEZ R.quintanilla Department of Applied Mathematics I University of VigoCampus As Lagoas MarcosendeVigo 36310Spain Department of Mathematics Polytechnic University of CataloniaTerrassa 08222Spain

We consider the system of equations determining the linear thermoelastic deformations of dielectrics within the recently called Moore-Gibson-Thompson(MGT)theory.First,we obtain the system of equations for such a case.Second,we consider the case of a rigid solid and show the existence and the exponential decay of solutions.Third,we consider the thermoelastic case and obtain the existence and the stability of the solutions.Exponential decay of solutions in the one-dimensional case is also recalled.

关键词： Moore-Gibson-Thompson(MGT)thermoelastic dielectrics existence semigroup exponential decay

Evaluation of different Krylov subspace methods for simulation of the water faucet problem

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Nuclear Science and Techniques 2021年第5期32卷 1-16页

作者： Hong-Yang Wei Kevin Briggs Victor quintanilla Yi-Tung Chen Department of Mechanical Engineering University of NevadaLas VegasNV 89154USA

In this study,a one-dimensional two-phase flow four-equation model was developed to simulate the water faucet problem.The performance of six different Krylov subspace methods,namely the generalized minimal residual(GMRES),transpose-free quasi-minimal residual,quasi-minimal residual,conjugate gradient squared,biconjugate gradient stabilized,and biconjugate gradient,was evaluated with and without the application of an incomplete LU(ILU)factorization preconditioner for solving the water faucet problem.The simulation results indicate that using the ILU preconditioner with the Krylov subspace methods produces better convergence performance than that without the ILU preconditioner.Only the GMRES demonstrated an acceptable convergence performance under the Krylov subspace methods without the preconditioner.The velocity and pressure distribution in the water faucet problem could be determined using the Krylov subspace methods with an ILU preconditioner,while GMRES could determine it without the need for a preconditioner.However,there are significant advantages of using an ILU preconditioner with the GMRES in terms of efficiency.The different Krylov subspace methods showed similar performance in terms of computational efficiency under the application of the ILU preconditioner.

关键词： Water faucet problem Krylov subspace methods ILU preconditioner

Convergence in leaf phenology traits of two understorey ferns in the northwestern Iberian Peninsula

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Journal of Plant Ecology 2018年第1期11卷 92-102页

作者： Luis G.quintanilla Beatriz Pías Department of Biology and Geology Physics and Inorganic ChemistrySchool of Environmental Sciences and TechnologyRey Juan Carlos Universityc/Tulipán s/n28933 MóstolesMóstolesSpain Department of Plant Sciences Faculty of BiologyComplutense of Madrid UniversityMadridSpain

Aims Plants control leaf phenology to maximize annual photosynthetic product.Although ferns play an important ecological role in many habitats,especially forests,their phenology traits have been poorly studied.Here,we investigate the leaf phenology of two ferns of the forest understorey and analyse the relationship between the timing of leaf emergence and spore dispersal and the effect of between-year climatic variation.Methods We compared the leafing and sporing phenologies of two ferns with very large(>2 m),overwintering leaves:Culcita macrocarpa and Woodwardia radicans.We regularly monitored individuals of six popu-lations in the northwestern Iberian Peninsula during a 3-year study.We studied eight phenology variables:leafing start date,leafing end date,leaf expansion time,number of new leaves per individual,between-individual synchrony,within-individual synchrony,percentage of fertile leaves and spore release date.We also determined leaf mass per area(LMA)and gathered data on air temperature and humidity.Important findings Both C.macrocarpa and W.radicans produce few leaves(~2 leaves individual−1 year−1),which expand simultaneously for a very long period(from midwinter to early summer),are retained for more than 1 year(37 and 19 months,respectively)and have relatively high LMAs.Such traits,together with large leaf size,have also been found in seed plants from the forest understorey and represent adap-tations to this light-limited environment.Spores of both study ferns are simultaneously released in late winter,with little between-year variation caused by differences in air humidity.This remarkable similarity between species suggests that the convergence in tim-ing of leaf emergence favours the convergence in timing of spore dispersal.

关键词： Culcita macrocarpa leaf phenology spore dispersal temperate forest Woodwardia radicans

Use of silica nanopowder to accelerate CO_2 sorption by Ca(OH)_2

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Particuology 2013年第4期11卷 448-453页

作者： M.A.S.quintanilla J.M.Valverde Faculty of Physics University of SevilleAvenida Reina Mercedes s/n

Promising technologies have recently emerged to capture CO2 from postcombustion flue gas and to enhance the production of hydrogen from natural gas by steam-methane reforming, on the basis of sorp- tion of CO2 by Ca-based powders. The rate of CO2 sorption on Ca-based powders is limited by both carbonation kinetics and transport of CO2 to unreacted sorption sites. Ca-based powders may exhibit cohesive aggregation, thus hindering gas-solids contact efficiency. In our work, we tested the sorption rate of powder samples prepared by dry mixing of a cohesive Ca（OH）2 powder with a silica nanopowder used as additive. The silica nanopowder serves to improve the dispersibility of Ca（OH）2. Consequently, when a CO2 enriched gas and the modified sorbent are brought into contact, the rate of CO2 sorption is enhanced in the initial fast phase of interest for practical applications.

关键词： FluidizationFine powdersCO2 sorptionNanoparticles

Effect of magnetic field orientation on fluidized beds of magnetic particles:Theory and experiment

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Particuology 2014年第1期12卷 54-63页

作者： Miguel ángel Sánchez quintanilla Manuel Jesús Espin José Manuel Valverde Department of Electronics and Electromagnetism University of Seville Department of Applied PhysicsⅡ University of Seville

Geldart-A fluidized beds of fine particles experience a jamming transition between a fluid-like state and a solid-like state at a certain superficial gas velocity, that depends on the relative strength of interparticle attractive forces with respect to particle weight, lnterparticle forces provide the bed with a certain tensile strength in the jammed state. In the work presented here we analyze the behavior of a fluidized bed of magnetic particles subjected to an externally applied magnetic field, which contributes to enhance interparticle forces. The importance of the magnetic contribution to interparticle forces is measured by the changes in the tensile strength and the superficial gas velocity at the jamming transition. The link of the field orientation with the microstructure of the bed is discussed,

关键词： Magneto-fluidization Jamming transition Fluidization Fine powders Cohesion Magnetization