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Relict glacial landscape in the Sierra Baguales Mountain Range(50°-51°S):evidence of glaciation dynamics and types in the eastern foothills of the southern Patagonian Andes

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Journal of Mountain Science 2017年第2期14卷 282-295页

作者： ARAOS.JoséMiguel LE ROUX.Jacobus Philiphus gutierrez.néstor mauricio Department of Geology FCFMUniversidad de ChilePlaza Ercilla#803SantiagoChile Department of Geography Faculty of Social Sciences.Universidad Alberto HurtadoUienfuegos#41SantiagoChile Department of Geology FCFMUniversidad de Chile.Andean Geothermal Centre of ExcellencePlaza Ereilla#803SantiagoChile

The glacial morphology of southern South American presents invaluable evidence to reconstruct former glacier behaviour and its relation to climate and environmental changes. However, there are still spatial and temporal gaps in the reconstruction of the Holocene Patagonian glacial landscape. Here we present the first geomorphological record for the Sierra Baguales Mountain Range(SBMR), forming the eastern foothills of the Southern Patagonian Andes 200 km from the Pacific coast. This area is topographically isolated from the Southern Patagonian Ice Field(SPIF), and is affected by the Westerly Winds. The study area shows evidence of ice sheet and alpine glaciations related to Andean uplift,which caused a marked climatic contrast between its western and eastern flanks since the Last Glacial Maximum(LGM). The regional rock mass strength and precipitation gradient acted as a controlling factor in the glacial cirque distribution and sizes, as well as in the development of glaciation types. We report new radiocarbon dates associated with warm/dry to cold/wet climatic changes during the middle Holocene, when former small alpine glaciers were located in the uppermost section of the SBMR basins, and eventually converged to form a small ice field or a composite valley glacier at lower *** can be explained by an estimated regional temperature drop of 3.8°C±0.8°C, based on a 585±26m Equilibrium Line Altitude(ELA) descent, inferred by geomorphological evidence and the Accumulation Area Ratio(AAR), in addition to a free-air adiabatic lapse rate. Subsequently, the glaciers receded due to climatic factors including a rise in temperature, as well as non-climatic factors, mainly the glacier bedrock topography.

关键词： Glacial morphology Sierra Baguales Ice sheet glaciations Alpine glaciations Middle Holocene

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The pitfalls in electrocatalytic nitrogen reduction for ammonia synthesis

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Journal of Energy Chemistry 2021年第10期30卷 149-154,I0005页

作者： Huimin Liu néstor Guijarro Jingshan Luo Institute of Photoelectronic Thin Film Devices and Technology Solar Energy Research CenterKey Laboratory of Photoelectronic Thin Film Devices and Technology of TianjinMinistry of Education Engineering Research Center of Thin Film Photoelectronic TechnologyRenewable Energy Conversion and Storage CenterNankai UniversityTianjin 300350China Institute of Electrochemistry University of AlicanteAlicante E-03080Spain

Ammonia synthesis by electrocatalytic nitrogen reduction reaction(EC-nRR)has gained momentum in recent years fueled by its potential to operate at ambient conditions,unlike the highly energyintensive yet long-standing Haber-Bosch ***,the large disparity of the yields and Faradic efficiencies reported for EC-nRR raises serious concerns about the reliability of the experimental *** this perspective,we elaborate on the potential sources of error when assessing EC-nRR and update the testing protocols to circumvent them,and more importantly,we pose a general call for consensus on ammonia production analysis and reporting to lay the solid foundations that this burgeoning field requires to thrive.

关键词： Electrocatalytic nitrogen reduction Ammonia synthesis Pitfalls Standard protocols

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Glacier reconstruction of La Covacha Massif in Sierra de Gredos(central Spain) during the Last Glacial Maximum

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Journal of Mountain Science 2019年第6期16卷 1336-1352页

作者： néstor CAMPOS David PALACIOS Luis M.TAnARRO Department of Geography Complutense University of Madrid

A paleoglacier reconstruction during the Last Glacial Maximum(LGM) is presented for a high mountain area of La Covacha massif in Sierra de Gredos(Iberian Central System) in central Spain. The moraines that, according with the previous literature, had formed during the global LGM, were mapped through photo interpretation of digital aerial photographs and 3D images and detailed field surveys. The topography of the paleoglaciers was estimated using a simple steady-state model that assumed a perfectly plastic ice rheology, reconstructing the theoretical ice profiles and obtaining the ice thickness of the glaciers during the LGM. The reconstruction of the glaciers was carried out using automated and semi-automated physically-based models, obtaining more realistic results with semi-automated models. According to our study, the paleoglaciers in the study area covered an area of 34.79 km^2 during the global LGM, with a maximum ice thickness of 366 meters in La Vega gorge, a total volume of 34.25 × 108 m^3 and a mean paleoELA of 1932 meters. Most of the ice(~82%) was in paleoglaciers facing north, and the rest was in paleoglaciers with other orientations. This emphasizes the importance of orientation in relation to glacier dynamics and ice accumulation. The results obtained in the calculation of paleoELAs during the global LGM in Gredos are average compared to the Iberian mountains of the northwest where the values were much lower, and with respect to those of the Southwest, much higher. This demonstrates the importance of the exposure of Mediterranean mountains to the humidity sources coming from the nW during the global LGM, as is the case at present.

关键词： Glacier reconstruction Paleoglacier Ice thickness Equilibrium line altitude Iberian Central System

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Sol–gel La2O3–ZrO2 mixed oxide catalysts for biodiesel production

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Journal of Energy Chemistry 2018年第2期27卷 565-572页

作者： Daniela Salinas Catherine Sepúlveda néstor Escalona J.L.GFierro Gina Pecchi Departamento de Fisicoquimica. Facultad de Ciencias Quimicas Universidad de Concepcion Post Office 160-C Concepcion Chile Departamento de Quimica Facultad de Ciencias Universidad del Biobio Post Office 5-C Concepcion Chile Departamento Ingenieria Quimica y Bioprocesos Escuela de lngenieria Pontificia Universidad Catolica de Chile Avda. Vicuria Mackenna 4870 Maeul Santiago 7820436 Chile Centro de Investigacion en nanotecnolagia y Materiales Avanzados (CIEn-UC) Pontificia Universidad Catolica de Chile Post Office 306 Santiago Chile Departamento de Quimica Fisica Facultad de Quimica Pontificia Universidad Catolica de Chile Post Offce 306 Santiago Chile Instituto de Catalisis y Petroleoquimica CSIC 28049 Madrid. Espana

Different La2O3 contents（0, 1, 2, 3, and 5 wt%） were used to prepared La2O3-ZrO2 mixed oxides calcined at 600 ℃ by the sol-gel method. The catalytic activity was measured as biodiesel production from canola oil through a transesterification reaction. The characterization results indicate that the La2O3 monolayer formation and extent of basicity of m-ZrO2 have a large influence on biodiesel *** biodiesel conversion（56% at 4 h） was obtained with the 3% La2O3-ZrO2 catalyst in the presence of basic sites and the formation of a monolayer of La2O3. The decrease in the catalytic activity for 5% La2O3-ZrO2 resulted from the loss of active sites on the catalyst because of agglomeration, which was suggested by XPS and the isoelectric point. The kinetic data fit to a pseudo-first order constant, and the largest kinetic constant corresponds to 3% La2O3-ZrO2, currently the largest heterogeneous non-alkaline metal catalyst reported for a transesterification reaction.

关键词： La2O3 -ZrO2 Sol-gel Biodiesel Canola oil Transesterification

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nucleoside modified mRnA-lipid nanoparticles as a new delivery platform for the repair of the injured spinal cord

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neural Regeneration Research 2025年第8期20卷 2311-2312页

作者： Krisztián Pajer Tamás Bellák Antal nógrádi Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary

Spinal cord injury and treatment opportunities:The adult mammalian spinal cord has a very limited capacity for spontaneous regeneration due to various intrinsic molecular and cellular *** the spinal cord neurons have the capacity to regenerate their axons,the expression of growth inhibitory factors,lack or suppression of proper guidance cues,and profound inflammatory responses do not permit successful regeneration(Khyeam et al.,2021).

关键词： injured capacity modified

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Green ionic metal-organic frameworks as nanocatalysts for CO_(2)fixation

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nano Research 2025年第1期18卷 260-269页

作者： nuria Martín Miguel Maireles-Porcar Julián Sánchez Velandia Belén Altava Francisco G.Cirujano Eduardo García-Verdugo Departamento de Química Inorgánica y Orgánica Universidad Jaume IAv.Sos Baynats/nCastellóde la PlanaCastellón 12071Spain

Co,ni,and Zn iso-reticular coordination polymers of 2,5-dihydroxyterphthalic acid(H_(2)dot)can be rapidly obtained under room temperature and aqueous conditions using either sodium or ammonium hydroxide as the bases to deprotonate the *** use of metal bromides and tetrabutylammonium hydroxide(TBAOH)as the base allows the green synthesis of ionic metal-organic frameworks(MOFs),characterized by X-ray diffraction(XRD),Fourier transform infrared(FTIR),scanning electron microscopy(SEM),thermo gravimetric analysis(TGA),H-nuclear magnetic resonance(nMR),elemental analysis,and X-ray photoelectron spectroscopy(XPS),and employed in the pressure,solvent,and additive-free CO_(2)fixation to epoxides by its cycloaddition to epichlorohydrin,exhibiting a cooperative behavior between the MOF and the ionic liquid formed within the framework,achieving TOns of the confined tetrabutylammonium bromide(TBABr)up to 700.

关键词： metal-organic frameworks(MOFs) ionic liquids heterogeneous catalysis CO_(2)conversion

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Impacts of PI3K/protein kinase B pathway activation in reactive astrocytes: from detrimental effects to protective functions

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neural Regeneration Research 2025年第4期20卷 1031-1041页

作者： Ramón Pérez-núñez María Fernanda González Ana María Avalos Lisette Leyton Cellular Communication Laboratory Programa de Biología Celular y MolecularCenter for Studies on ExerciseMetabolism and Cancer(CEMC)Instituto de Ciencias Biomédicas(ICBM)Facultad de MedicinaUniversidad de ChileSantiagoChile Advanced Center for Chronic Diseases(ACCDiS) Faculty of Chemical and Pharmaceutical Sciences&Faculty of MedicineUniversidad de ChileSantiagoChile Instituto de Ciencias Biomédicas Facultad de Ciencias de la SaludUniversidad Autónoma de ChileSantiagoChile

Astrocytes are the most abundant type of glial cell in the central nervous *** injury and inflammation,astrocytes become reactive and undergo morphological and functional *** on their phenotypic classification as A1 or A2,reactive astrocytes contribute to both neurotoxic and neuroprotective responses,***,this binary classification does not fully capture the diversity of astrocyte responses observed across different diseases and *** analysis has revealed that reactive astrocytes have a complex landscape of gene expression profiles,which emphasizes the heterogeneous nature of their *** actively participate in regulating central nervous system inflammation by interacting with microglia and other cell types,releasing cytokines,and influencing the immune *** phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)signaling pathway is a central player in astrocyte reactivity and impacts various aspects of astrocyte behavior,as evidenced by in silico,in vitro,and in vivo *** astrocytes,inflammatory cues trigger a cascade of molecular events,where nuclear factor-κB serves as a central mediator of the pro-inflammatory ***,we review the heterogeneity of reactive astrocytes and the molecular mechanisms underlying their *** highlight the involvement of various signaling pathways that regulate astrocyte reactivity,including the PI3K/AKT/mammalian target of rapamycin(mTOR),αvβ3 integrin/PI3K/AKT/connexin 43,and notch/PI3K/AKT *** targeting the inactivation of the PI3K/AKT cellular signaling pathway to control reactive astrocytes and prevent central nervous system damage,evidence suggests that activating this pathway could also yield beneficial *** dual function of the PI3K/AKT pathway underscores its complexity in astrocyte reactivity and brain function *** review emphasizes the importance of employing astrocyte-exclusive models to underst

关键词： inflammation integrins neuroprotective neurotoxic phosphatidylinositol 3-kinase reactive astrocytes signal transduction Thy-1(CD90)

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A MIXED VIRTUAL ELEMEnT METHOD FOR THE BOUSSInESQ PROBLEM On POLYGOnAL MESHES

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Journal of Computational Mathematics 2021年第3期39卷 392-427页

作者： Gabriel n.Gatica mauricio Munar Filander A.Sequeira CI^2 MA and Departamento de Ingenieria Matemitica Universidad de ConcepcionCasilla 160-CConcepcionChile Escuela de Matemaitica Universidad NacionalCampus Omar DengoHerediaCosta Rica

In this work we introduce and analyze a mixed virtual element method(mixed-VEM)for the two-dimensional stationary Boussinesq *** continuous formulation is based on the introduction of a pseudostress tensor depending nonlinearly on the velocity,which allows to obtain an equivalent model in which the main unknowns are given by the aforementioned pseudostress tensor,the velocity and the temperature,whereas the pressure is computed via a postprocessing *** addition,an augmented approach together with a fixed point strategy is used to analyze the well-posedness of the resulting continuous *** the discrete problem,we follow the approach employed in a previous work dealing with the navier-Stokes equations,and couple it with a VEM for the convection-diffusion equation modelling the *** precisely,we use a mixed-VEM for the scheme associated with the fluid equations in such a way that the pseudostress and the velocity are approximated on virtual element subspaces of H(div)and H^(1),respectively,whereas a VEM is proposed to approximate the temperature on a virtual element subspace of H^(1).In this way,we make use of the L^(2)-orthogonal projectors onto suitable polynomial spaces,which allows the explicit integration of the terms that appear in the bilinear and trilinear forms involved in the scheme for the fluid *** the other hand,in order to manipulate the bilinear form associated to the heat equations,we define a suitable projector onto a space of polynomials to deal with the fact that the diffusion tensor,which represents the thermal conductivity,is ***,the corresponding solvability analysis is performed using again appropriate fixed-point ***,Strang-type estimates are applied to derive the a priori error estimates for the components of the virtual element solution as well as for the fully computable projections of them and the postprocessed *** corresponding rates of convergence are als

关键词： Boussinesq problem Pseudostress-based formulation Augmented formulation Mixed virtual element method.High-order approximations

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Astrocytes, reactive astrogliosis, and glial scar formation in traumatic brain injury

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neural Regeneration Research 2025年第4期20卷 973-989页

作者： María Belén Cieri Alberto Javier Ramos Laboratorio de neuropatología Molecular IBCN UBA-CONICETFacultad de MedicinaUniversidad de Buenos AiresBuenos AiresArgentina

Traumatic brain injury is a global health crisis,causing significant death and disability *** that follows traumatic brain injury has serious consequences for neuronal survival and cognitive impairments,with astrocytes involved in this *** traumatic brain injury,astrocytes rapidly become reactive,and astrogliosis propagates from the injury core to distant brain *** astroglial proteins are downregulated near the traumatic brain injury core,while pro-inflammatory astroglial genes are *** altered gene expression is considered a pathological remodeling of astrocytes that produces serious consequences for neuronal survival and cognitive *** addition,glial scar formed by reactive astrocytes is initially necessary to limit immune cell infiltration,but in the long term impedes axonal reconnection and functional *** therapeutic strategies for traumatic brain injury are focused on preventing acute ***,cannabinoids,progesterone,beta-blockers,and cerebrolysin demonstrate neuroprotective benefits but most of them have not been studied in the context of *** this review,we discuss the cell signaling pathways activated in reactive astrocytes following traumatic brain injury and we discuss some of the potential new strategies aimed to modulate astroglial responses in traumatic brain injury,especially using cell-targeted strategies with miRnAs or lncRnA,viral vectors,and repurposed drugs.

关键词： astrocyte glial scar innate immunity neuroinflammation stab injury Toll-like receptors

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Sex differences in aging and injured brain

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neural Regeneration Research 2025年第10期20卷 2901-2902页

作者： Jordan n.Williamson Yuan Yang University of Illinois Urbana-Champaign Grainger College of EngineeringDepartment of BioengineeringUrbanaILUSA Carle Foundation Hospital Stephenson Family Clinical Research InstituteClinical Imaging Research CenterUrbanaILUSA University of Illinois Urbana-Champaign Beckman Institute for Advanced Science and TechnologyUrbanaILUSA northwestern University Department of Physical Therapy and Human Movement SciencesChicagoILUSA

Background:The prevalence,age of onset,and symptomatology of traumatic brain injury,stroke,and neurodegenerative diseases(such as Alzheimer’s disease(AD),Parkinson’s disease,amyotrophic lateral sclerosis,and Huntington’s disease)differ substantially between males and *** higher prevalence of these brain disorders has been attributed to females having a greater longevity compared with *** one of the greatest risk factors of acquired brain injury(such as stroke,traumatic brain injury caused by fall)and neurodegenerative disease is age.

关键词： Huntington prevalence traumatic

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