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Three-dimensional acoustic propagation model for shallow waters based on an indirect boundary element method

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Chinese Physics B 2023年第5期32卷 485-495页

作者： Edmundo F.Lavia juan d.Gonzalez Silvia Blanc Acoustic Propagation department Argentinian Navy Research Office(DIIV)Buenos Aires 1638Argentina UNIdEF(National Council of Scientific and Technical Research/Ministry of defense) Buenos AiresArgentina

This work has a two-fold *** the one hand,the theoretical formulation of a three-dimensional(3d)acoustic propagation model for shallow waters with a constant sound speed is presented,based on the boundary element method(BEM),which uses a half-space Green function instead of the more conventional free-space Green *** the other hand,a numerical implementation is illustrated to explore the formulation in simple idealized cases,controlled by a few parameters,which provides necessary tests for the accuracy and performance of the *** half-space Green's function,which has been previously used in scattering and diffraction,adds terms to the usual expressions of the integral operators without altering their continuity *** against the wavenumber integration solution of the Pekeris waveguide suggest that the model allows an adequate prediction for the acoustic ***,numerical experiments in relation to the necessary mesh size for the description of the water-marine sediment interface lead to the conclusion that a transmission loss prediction with acceptable accuracy can be obtained with the use of a limited mesh around the desired evaluation region.

关键词： three-dimensional acoustic propagation boundary element method half-space Green function

Inflammasome links traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease

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Neural Regeneration Research 2025年第6期20卷 1644-1664页

作者： Gabriela Seplovich Yazan Bouchi juan Pablo de Rivero Vaccari Jennifer C.Munoz Pareja Andrew Reisner Laura Blackwell Yehia Mechref Kevin K.Wang J.Adrian Tyndall Binu Tharakan Firas Kobeissy department of Surgery Morehouse School of MedicineAtlantaGAUSA department of Neurobiology Center for NeurotraumaMultiomics&Biomarkers(CNMB)Neuroscience InstituteMorehouse School of MedicineAtlantaGAUSA department of Neurological Surgery and the Miami Project to Cure Paralysis University of Miami Miller School of MedicineMiamiFLUSA division of Pediatric Critical Care Department of PediatricsUniversity of Miami Miller School of MedicineMiamiFLUSA department of Pediatrics Emory UniversityAtlantaGAUSA department of Neurosurgery Children’s Healthcare of AtlantaAtlantaGAUSA department of Chemistry and Biochemistry Texas Tech UniversityLubbockTXUSA Morehouse School of Medicine AtlantaGAUSA

Traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease are three distinct neurological disorders that share common pathophysiological mechanisms involving neuroinflammation. One sequela of neuroinflammation includes the pathologic hyperphosphorylation of tau protein, an endogenous microtubule-associated protein that protects the integrity of neuronal cytoskeletons. Tau hyperphosphorylation results in protein misfolding and subsequent accumulation of tau tangles forming neurotoxic aggregates. These misfolded proteins are characteristic of traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease and can lead to downstream neuroinflammatory processes, including assembly and activation of the inflammasome complex. Inflammasomes refer to a family of multimeric protein units that, upon activation, release a cascade of signaling molecules resulting in caspase-induced cell death and inflammation mediated by the release of interleukin-1β cytokine. One specific inflammasome, the NOd-like receptor protein 3, has been proposed to be a key regulator of tau phosphorylation where it has been shown that prolonged NOd-like receptor protein 3 activation acts as a causal factor in pathological tau accumulation and spreading. This review begins by describing the epidemiology and pathophysiology of traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease. Next, we highlight neuroinflammation as an overriding theme and discuss the role of the NOd-like receptor protein 3 inflammasome in the formation of tau deposits and how such tauopathic entities spread throughout the brain. We then propose a novel framework linking traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease as inflammasomedependent pathologies that exist along a temporal continuum. Finally, we discuss potential therapeutic targets that may intercept this pathway and ultimately minimize long-term neurological decline.

关键词： Alzheimer's disease caspase-1 chronic traumatic encephalopathy inflammasomes neurodegeneration neuroinflammation NLRP1 NLRP3 pyroptosis tauopathy traumatic brain injury

Oligodendroctyes:the forgotten players of diabetes pathophysiology

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Neural Regeneration Research 2024年第11期19卷 2349-2350页

作者： juan Antonio López-Villodres Beatriz García-díaz departamento Fisiología Humana Histología HumanaAnatomía Patológica y Educación Física y DeportivaFacultad de MedicinaUniversidad de MálagaMálagaSpain UGC Neurociencia.Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina(IBIMA Plataforma Bionand) MálagaSpain

Oligodendrocytes(OLs),glial cells that provide myelin sheaths to axons in the central nervous system(CNS),have a dual ***,this myelin fatty cover around the axons protects the nerves and is crucial for the saltatory propagation of action *** and not less important,OLs provide trophic support to neurons and ***,OL metabolism is important for OL well-being and the proper accomplishment of their functions,and OL metabolism energetics directly affect the energy metabolism of neighboring neurons.

关键词： metabolism nerves myelin

Nonlinear numerical assessment of the seismic response of hillside RC buildings

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Earthquake Engineering and Engineering Vibration 2021年第2期20卷 423-440页

作者： Miguel A.Gómez Edgar Giovanny díaz-Segura juan Carlos Vielma Civil Engineering School Pontificia Universidad Católica de ValparaísoValparaíso 2340000Chile

Major damage has been reported in hilly areas after major earthquakes,primarily because of two special conditions:the variation in the seismic ground motion due to the inclined ground surface and the irregularities caused by a stepped base level in the *** aim of this study is to evaluate possible differences in the responses of Chilean hillside buildings through numerical linear-elastic and nonlinear *** the first step,a set of response-spectrum analyses were performed on four simplified 2d structures with mean base inclination angles of 0°,15°,30°,and 45°.The structures were designed to comply with Chilean seismic codes and standards,and the primary response parameters were *** assess the seismic performance of the buildings,nonlinear static(pushover)and dynamic(time-history)analyses were performed with SeismoStruct *** analyses were used to compare the nonlinear response at the maximum roof displacement and the damage ***-history analyses were performed to assess the nonlinear dynamic response of the structures subjected to seismic ground motions modified by topographic *** consider the topographic modification,acceleration records were obtained from numerical models of soil,which were calculated using the rock acceleration record of the Mw 8.01985 Chilean *** differences in the structure responses(roof displacements and maximum element forces and moments)were caused by the topographic effects in the seismic input motion,with the highly predominant ones being the differences caused by the step-back configuration at the base of the *** concentrations of shear forces in short walls were observed,corresponding to the walls located in the upper zone of the foundation *** response of the structures with higher angles was observed to be more prone to fragile failures due to the accumulation of shear *** though hillside buildings gain stiffness in the lower stories,resulting

关键词： topographic effect hillside buildings nonlinear analyses shear-wall buildings

Optimized Convolutional Neural Network Models for Skin Lesion Classification

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Computers, Materials & Continua 2022年第2期70卷 2131-2148页

作者： juan Pablo Villa-Pulgarin Anderson Alberto Ruales-Torres daniel arias-GarzónMario Alejandro Bravo-Ortiz Harold Brayan Arteaga-Arteaga Alejandro Mora-RubioJesus Alejandro Alzate-Grisales Esteban Mercado-Ruiz M.Hassaballah Simon Orozco-arias Oscar Cardona-Morales Reinel Tabares-Soto department of Electronics and Automation Universidad Autónoma deManizalesManizales170001Colombia SEdMATEC Corporación Universitaria Autónoma de Nari駉Pasto520002Colombia department of Computer Science Faculty of Computers and InformationSouth Valley UniversityQena83523Egypt department of Computer Science Universidad Autónoma de ManizalesManizales170001Colombia department of Systems and Informatics Universidad de CaldasManizales170001Colombia

Skin cancer is one of themost severe diseases,andmedical imaging is among themain tools for cancer *** images provide information on the evolutionary stage,size,and location of tumor *** paper focuses on the classification of skin lesion images considering a framework of four experiments to analyze the classification performance of Convolutional Neural Networks(CNNs)in distinguishing different skin *** CNNs are based on transfer learning,taking advantage of ImageNet ***,in each experiment,different workflow stages are tested,including data augmentation and fine-tuning *** CNN models based on denseNet-201,Inception-ResNet-V2,and Inception-V3 are proposed and compared using the HAM10000 *** results obtained by the three models demonstrate accuracies of 98%,97%,and 96%,***,the best model is tested on the ISIC 2019 dataset showing an accuracy of 93%.The proposed methodology using CNN represents a helpful tool to accurately diagnose skin cancer disease.

关键词： deep learning skin lesion convolutional neural network data augmentation transfer learning

Virtual Conductance Based Cascade Voltage Controller for VSCs in Islanded Operation Mode

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1704-1713页

作者： Francisco Jesús Matas-díaz Manuel Barragán-Villarejo juan Carlos Olives-Camps juan Manuel Mauricio JoséMaría Maza-Ortega department of Elec‐trical Engineering Universidad de SevillaSeville 41092Spain

Voltage source converters have become the main enabler for the integration of distributed energy resources in *** the case of islanded operation,these devices normally set the amplitude and frequency of the network voltage by means of a cascade controller composed of an outer voltage control loop and an inner current control *** strategies to compute the gains of both control loops have been proposed in the literature in order to obtain a fast and decoupled response of the voltages at the point of common *** paper proposes an alternative and simple methodology based on the introduction of a virtual conductance in the classic cascade *** strategy allows to design each control loop independently,obtaining a closed-loop response of a first-order *** this way,the gains of each control loop are easily derived from the parameters of the LC coupling filter and the desired closed-loop time ***,a state observer is included in the controller to estimate the inductor current of the LC filter in order to reduce the number of required measurements.A laboratory testbed is used to validate and compare the proposed *** experimental results demonstrate the effectiveness of the proposal both in steady-state and transient regimes.

关键词： Voltage source converter microgrid cascade controller virtual conductance

Stress tensors and quantification of fracture patterns to analyze connectivity and potential fluid flow in a mesa landform of the Northern Andes

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Journal of Mountain Science 2024年第1期21卷 271-291页

作者： GARCÍA-arias Sergio VELANdIA Francisco ALVAREZ Angélica SANABRIA-GÓMEZ Joséd TARAZONA Yessenia VARGAS María Camila Escuela de Geología Universidad Industrial de SantanderCra.27 Calle 9BucaramangaColombia Escuela de Física Universidad Industrial de SantanderCra.27 Calle 9BucaramangaColombia

This work applies stress tensors inversions and quantification of fracture patterns along the Mesa de Los Santos, in the Eastern Cordillera of Colombia, to better understand the potential fluid flow. It thus contributes to the conceptual hydrogeological model. The area was subdivided into three blocks, separated by the NW Potreros and the Los Santos faults, having minor inner faults of different orientations. This separation facilitates the analysis of the fractures measured in the field, which in general show high dip angles and a conjugate geometry in the northern block, tension fractures(Mode I) in the central block, and a random distribution in the southwestern block. WinTensor treatment of slickensides yielded a maximum horizontal stress(SHmax) of 111o, which coincides with the WNW-ESE tensor observed from the conjugate and tension joints. We then used Frac Pa Q to generate interpolation maps of fracture intensity and density. The maps show the highest values in the central block and the lowest in the northern block,where the precipitation is higher, causing intensive rock weathering and homogenization of the fracture planes. Although the highest values of connectivity by line are found to the south of the mesa, we suggest the possibility of greater flow from the recharge zone(NE) along bedding planes and open NW-SE fractures.

关键词： Mesa de Los Santos Colombia Win-Tensor FracPaQ Strike-slip faults Fractured aquifers

Thermo-electro-mechanical microstructural interdependences in conductive thermoplastics

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npj Computational Materials 2023年第1期9卷 955-965页

作者： Javier Crespo-Miguel Sergio Lucarini Angel arias daniel Garcia-Gonzalez department of Continuum Mechanics and Structural Analysis Universidad Carlos III de MadridAvda.de la Universidad 3028911 LeganésMadridSpain department of Civil and Environmental Engineering Imperial College of LondonSouth Kensington CampusLondon SW72AZUK

Additive manufacturing has enabled the design of thermoplastic components that provide structural support,electrical conductivity and heat generation modulated by mechanical *** mechanisms and interplays that govern the material response at the microstructural level remain,however,***,we develop an experimental method to characterise conductive filaments from a combined mechanical,electrical and thermal *** approach is used to unravel exciting material interplays of conductive polylactic *** overcome experimental limitations that prevent a complete microstructural analysis of the problem,we develop a full-field homogenisation framework and implement it for finite *** framework accounts for viscoplasticity,electrical and thermal conduction,convection and heat generation via Joule effect,as well as for the interdependences between *** experimental validation,the framework is applied to virtually optimise fabrication requirements to obtain desired properties in final products,i.e.,stiffer products,filaments with higher conductivities or with better sensing capabilities.

关键词： conductive electrical overcome

Towards full repair of defects in reduced graphene oxide films by two-step graphitization

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Nano Research 2013年第3期6卷 216-233页

作者： Ruben Rozada juan I, Paredes Silvia Villar-Rodil Amelia Marlinez-Alonso juan M. d. Tascon Instituto Nacional del Carbon INCAR-CSIC Apartado 73 33080 Oviedo Spain

The complete restoration of a perfect carbon lattice has been a central issue in the research on graphene derived from graphite oxide since this preparation route was first proposed several years ago, but such a goal has so far remained elusive. Here, we demonstrate that the highly defective structure of reduced graphene oxide sheets assembled into free-standing, paper-like films can be fully repaired by means of high temperature annealing （graphitization）. Characterization of the films by X-ray photoelectron and Raman spectroscopy, X-ray diffraction and scanning tunneling microscopy indicated that the main stages in the transformation of the films were （i） complete removal of oxygen functional groups and generation of atomic vacancies （up to 1,500 ~C）, and （ii） vacancy annihilation and coalescence of adjacent overlapping sheets to yield continuous polycrystalline layers （1,800-2,700 ~C） similar to those of highly oriented graphites. The prevailing type of defect in the polycrystalline layers were the grain boundaries separating neighboring domains, which were typically a few hundred nanometers in lateral size, exhibited long-range graphitic order and were virtually free of even atomic-sized defects. The electrical conductivity of the annealed films was as high as 577,000 S-m-1, which is by far the largest value reported to date for any material derived from graphene oxide, and strategies for further improvement without the need to resort to higher annealing temperatures are suggested. Overall, this work opens the prospect of truly achieving a complete restoration of the carbon lattice in graphene oxide materials.

关键词： graphene graphene oxide films annealing defect