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Metal-modulated epitaxy of Mg-doped Al_(0.80)In_(0.20)n-based layer for application as the electron blocking layer in deep ultraviolet light-emitting diodes

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Journal of Semiconductors 2024年第5期45卷 80-89页

作者： Horacio Irán Solís-Cisneros Carlos Alberto hernández-Gutiérrez Enrique Campos-González Máximo López-López Optomechatronics Group Tecnológico Nacional de México Campus Tuxtla Gutiérrezcarretera Panamericana 1080C.P.29050Tuxtla GutiérrezChiapasMéxico Departamento de Física Instituto Nacional de Investigaciones NuclearesCarretera México-Toluca s/nC.P.52750La Marquesa OcoyoacacMéxico Departamento de Física Centro de Investigación y estudios Avanzados del Instituto Politécnico NacionalAv.Instituto Politécnico Nacional 2508San Pedro ZacatencoGustavo A.Madero07360 Ciudad de MéxicoCDMXMéxico

This work reports the growth and characterization of p-AlInn layers doped with Mg by plasma-assisted molecular beam epitaxy(PAMBE).AlInn was grown with an Al molar fraction of 0.80 by metal-modulated epitaxy(MME)with a thickness of 180 nm on Si(111)substrates using Aln as buffer *** substrate temperatures were used to enhance the incorporation of indium atoms into the alloy without clustering,as confirmed by X-ray diffraction(XRD).Cathodoluminescence measurements revealed ultraviolet(UV)range ***,Hall effect measurements indicated a maximum hole mobility of 146 cm^(2)/(V∙s),corresponding to a free hole concentration of 1.23×10^(19)cm^(−3).The samples were analyzed by X-ray photoelectron spectroscopy(XPS)estimating the alloy composition and extracting the Fermi level by valence band ***-doped AlInn layers were studied for use as the electron-blocking layer(EBL)in LED *** varied the Al composition in the EBL from 0.84 to 0.96 molar fraction to assess its theoretical effects on electroluminescence,carrier concentration,and electric field,using SILVACO *** results from this study highlight the importance and capability of producing high-quality Mg-doped p-AlInn layers through *** simulations suggest that an Al content of 0.86 is optimal for achieving desired outcomes in electroluminescence,carrier concentration,and electric field.

关键词： metal-modulated epitaxy AlInn DUV-LED EBL simulation

Assessment of Mg(OH)_(2)/TiO_(2) coating in the Mg-Ca-Zn alloy for improved corrosion resistance and antibacterial performance

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Journal of Magnesium and Alloys 2023年第1期11卷 361-378页

作者： Leonardo hernández Jesús Ramón-Sierra Montserrat Soria-Castro Ángel Bacelis Geonel Rodríguez-Gattorno Elizabeth Ortiz-Vázquez Gloria Acosta Applied Physics Department Center for Research and Advanced Studies of the National Polytechnic Institute(CINVESTAV-IPN)Carr.Ant.a Progreso km.6C.P.97310MeridaYucatanMexico Tecnológico nacional de México/Instituto Tecnológico de Mérida.Av.Tecnológico s/n Km.4.5 ant.Carr.Mérida-Progreso C.P.97118MéridaYucatánMéxico Facultad de Química Universidad Nacional Autónoma de México(UNAM)Av.Universidad 3000C.P.04510CoyoacánCDMXMéxico

The high activity of metallic magnesium and alloys limits its potential in biomedical applications;in recent years,extensive efforts have been devoted to modulating this *** this work,we present Mg(OH)_(2) and TiO_(2)barrier coatings to reduce the degradation of magnesium alloy(Mg-Ca-Zn)*** coatings were deposited by the anodization method and the spin-coating technique,*** anodized layer was coated with TiO_(2)generated from the hydrolysis of 3%weight of TTIP(Ti[OCH(CH_(3))_(2)]_(4),Titanium(IV)isopropoxide)in 2-Propanol deposited by the spin-coating *** the degradation in Ringer’s solution by electrochemical impedance spectroscopy and OCP revealed a 98%reduction in pittings in uncoated samples after 14 days of *** p H measurements revealed that the TiO_(2)coating reduced the alkalization of the physiological environment,keeping the pH at 6.0 *** vitro studies of two types of bacteria(*** and ***)exhibited zones of inhibition in the agar and activity bactericidal(kill time test).The mechanisms behind the improved degradation resistance and enhanced antibacterial activity are presented and discussed *** modification with Mg(OH)_(2)/TiO_(2)coatings is a promising strategy to control the biodegradation of magnesium implants for bone regeneration.

关键词： Magnesium alloy EIS Mg(OH)_(2) TiO_(2) Antibacterial coatings

Taxonomy-based differences in feeding guilds of fish

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Current Zoology 2020年第1期66卷 51-56页

作者： Javier SAnCHEZ-hernAndez Departamento de Zooloxla Xenetica e Antropoloxfa FlsicaFacultade de BioloxfaUniversidade de Santiago de CompostelaCampus Vida s/nSantiago de CompostelaEspana

It has been taken for granted that feeding guilds and behavior in animals are linked to the taxonomic relatedness of species,but empirical evidence supporting such relationship is virtually *** examine the importance of taxonomy on trophic ecology,I here present the first well-resolved dietary taxonomy analysis based on feeding guilds(predation,herbivory,and filtering)among families and genera within the fish order *** relatedness in feeding did not vary with ecosystem dimension(marine ***).Although predation dominates among Perciformes fishes,this study shows that in most cases taxonomic units(family or genus)are composed by species with several feeding *** species are more similar in feeding compared with species that are taxonomically more distant demonstrating that there is a greater variation of feeding guilds within families than ***,there is no consistency in feeding guilds between family-and genus-level *** study provides empirical support for the notion that genera are more informative than families,underlining that family-level taxonomy should be avoided to infer feeding habits of fish species at finer taxonomic ***,the choice of taxonomic resolution(family or genus level)in ecological studies is key to avoid information loss and misleading results.I conclude that high-rank taxonomic units(i.e.,above the generic level)are not appropriate to test research hypotheses about the feeding of fish.

关键词： aquatic systems clades FishBase global datasets taxonomic sufficiency trophic ecology

Insights into the Effect of a natural Arsenate Dose on Growth,nodulation and Redox Metabolism of Soybean Plants

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Pedosphere 2019年第4期29卷 527-533页

作者： Eliana BIAnUCCI Ana FURLAn Luis E.hernández Stella CASTRO Instituto de Investigaciones Agrobiotecnológicas InIAB CONICET-UNRC Facultad de Ciencias ExactasFísico-Químicas y Naturales Universidad Nacional de Río Cuarto Laboratorio de Fisiología Vegetal Departamento de BiologíaUniversidad Autónoma de Madrid

Dear Editor, Arsenic (As) is a harmful metalloid that occurs in soil and water;its concentration varies considerably among geographic regions, with groundwater being the principal source of human contamination (Smedley and Kinniburgh, 2002). Besides the direct contamination effect of drinking water that contains high As concentration, human poisoning may also occur after ingestion of contaminated food.

关键词： natural Arsenate Soybean Plants Redox Metabolism

Open versus laparoscopic cholecystectomies in patients with or without type 2 diabetes mellitus in Spain from 2003 to 2013

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Hepatobiliary & Pancreatic Diseases International 2016年第5期15卷 525-532页

作者： JoséM de Miguel-Yanes Manuel Méndez-Bailón Rodrigo Jiménez-García Valentín hernández-Barrera napoleón Pérez-Farinós Fernando Turégano nuria Munoz-Rivas Ana López-de-Andrés Internal Medicine Department Hospital General Universitario“Gregorio Maranón”46Doctor Esquerdo28007MadridSpain Internal Medicine Department Hospital Clínico San CarlosCalle Profesor Martín Lagos28040MadridSpain Preventive Medicine and Public Health Department Health Sciences FacultyRey Juan Carlos UniversityAvenida de AtenasAlcorcón28292MadridSpain Spanish Agency of Alimentary Safety and nutrition Ministry of HealthSocial Policy and Equality56Alcalá28071MadridSpain Internal Medicine Department Hospital Infanta Leonor80Avenida Gran Vía del Este28031MadridSpain Surgery Department Hospital General Universitario“Gregorio Maranón”46Doctor Esquerdo28007MadridSpain

BACKGROUnD: This study aimed to compare the rates of open and laparoscopic cholecystectomies and outcomes in patients with or without type 2 diabetes mellitus (T2DM) in Spain from 2003 to 2013. METHODS: We collected all cases of open and laparoscopic cholecystectomies using national hospital discharge data and evaluated the annual cholecystectomy rates stratiifed by T2DM status. We analyzed tendency for in-hospital mortality (IHM). We also analyzed the impact of T2DM on IHM in patients who underwent cholecystectomies. RESULTS: We identiifed 611 533 cholecystectomies (71.3%laparoscopic) in the patients, in whom 78 227 (12.8%) patients had T2DM. The rates of open cholecystectomies were 3-fold higher (130.0/105 vs 41.1/105) in patients with T2DM than in those without T2DM, and the rate of laparoscopic cholecys-tectomies was almost 2-fold higher (195.2/105 vs 111.8/105) in patients with T2DM. The annual rate of laparoscopic pro-cedures showed an 11-year relative increase of 88.3% (from 117.0/105 to 220.3/105) in T2DM and 49.2% (from 79.2/105 to 118.2/105) in patients without T2DM (Pn procedures showed an 11-year relative decrease of 27.6% in patients with T2DM and 37.9% in those without T2DM (Pncy laparoscopic cho-lecystectomy was increased in the 11 years, whereas the rate of emergency open cholecystectomies was decreased (both Pnalysis revealed that older age, higher comorbidity and emergency cholecystectomy were associated with a higher IHM. Compared with patients without T2DM, patients with T2DM demonstrated a lower IHM after open cholecystectomy [OR=0.82 (0.78-0.87)], but a higher IHM after laparoscopic cholecystectomy (OR=1.18 (1.03-1.35))Time-trend analyses showed a signiifcant reduction in IHM in patients with or without T2DM after the two procedures. COnCLUSIOn: The rate of cholecystectomy was higher in patients with T2DM, and laparoscopic cholecystectomy was p

关键词： diabetes mellitus cholecystectomy mortality in-hospital mortality

Comparison of heuristic and deep learning-based methods for ground classification from aerial point clouds

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International Journal of Digital Earth 2020年第10期13卷 1115-1134页

作者： Mario Soilán belén Riveiro Jesús Balado Pedro Arias Department of Materials Engineering Applied Mechanics and ConstructionSchool of Industrial EngineeringUniversity of VigoVigoSpain Department of natural Resources and Environmental Engineering School of Mining EngineeringUniversity of VigoVigoSpain

The automatic definition of the ground from 3D point clouds has been a common process for the last two decades,with many different approaches and applications that can be found in a vast *** paper presents a comparison of three different methodological concepts for ground classification,in order to establish the advantages and drawbacks of each ***,a heuristic method,based on previous knowledge of the geometry and context of the 3D ***,a Deep Convolutional network based on Segnet that classifies 2D images generated from the 3D point ***,the third method applies a Deep Learning classification based on Pointnet,which takes 3D points directly as *** validate each method and compare them,public and labelled point clouds from the Actueel Hoogtebestand nederland dataset are ***,the three methods are validated against the ISPRS 3D Semantic Labeling Contest *** results obtained show that the deep learning-based approaches outperform the heuristic method,with F-scores above 96%.The best results were obtained using a shallower version of Segnet,with F-score above 97%.

关键词： Ground classification aerial point cloud deep learning point cloud processing

An OPTIMAL COnTROL PROBLEM FOR A LOTKA-VOLTERRA COMPETITIOn MODEL WITH CHEMO-REPULSIOn

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Acta Mathematica Scientia 2024年第2期44卷 721-751页

作者： Diana I.hernÁndez Diego A.RUEDA-GOMEZ Élder J.VILLAMIZAR-ROA Universidad Industrial de Santander Escuela de MatemáticasA.A.678BucaramangaColombia

In this paper we study a bilinear optimal control problem for a diffusive Lotka-Volterra competition model with chemo-repulsion in a bounded domain of ℝ^(ℕ),n=2,*** model describes the competition of two species in which one of them avoid encounters with rivals through a chemo-repulsion *** prove the existence and uniqueness of weak-strong solutions,and then we analyze the existence of a global optimal solution for a related bilinear optimal control problem,where the control is acting on the chemical ***,we derive first-order optimality conditions for local optimal solutions using the Lagrange multipliers ***,we propose a discrete approximation scheme of the optimality system based on the gradient method,which is validated with some computational experiments.

关键词： Lotka-Volterra chemo-repulsion optimal control optimality conditions

Alexander disease:the road ahead

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neural Regeneration Research 2023年第10期18卷 2156-2160页

作者： María A.Pajares Elena hernández-Gerez Milos Pekny Dolores Pérez-Sala Department of Structural and Chemical Biology Centro de Investigaciones Biológicas Margarita SalasMadridSpain Laboratory of Astrocyte Biology and CnS Regeneration Center for Brain RepairDepartment of Clinical NeuroscienceInstitute of Neuroscience and PhysiologySahlgrenska Academy at the University of GothenburgGothenburgSweden University of newcastle NewcastleNSWand the Florey Institute of Neuroscience and Mental HealthParkvilleVICAustralia

Alexander disease is a rare neurodegenerative disorder caused by mutations in the glial fibrillary acidic protein,a type III intermediate filament protein expressed in *** early(infantile or juvenile)and adult onsets of the disease are known and,in both cases,astrocytes present characteristic aggregates,named Rosenthal *** are spread along the glial fibrillary acidic protein sequence disrupting the typical filament network in a dominant *** the presence of aggregates suggests a proteostasis problem of the mutant forms,this behavior is also observed when the expression of wild-type glial fibrillary acidic protein is ***,several isoforms of glial fibrillary acidic protein have been described to date,while the impact of the mutations on their expression and proportion has not been exhaustively ***,the posttranslational modification patterns and/or the protein-protein interaction networks of the glial fibrillary acidic protein mutants may be altered,leading to functional changes that may modify the morphology,positioning,and/or the function of several organelles,in turn,impairing astrocyte normal function and subsequently affecting *** particular,mitochondrial function,redox balance and susceptibility to oxidative stress may contribute to the derangement of glial fibrillary acidic protein mutant-expressing *** study the disease and to develop putative therapeutic strategies,several experimental models have been developed,a collection that is in constant *** fact that most cases of Alexander disease can be related to glial fibrillary acidic protein mutations,together with the availability of new and more relevant experimental models,holds promise for the design and assay of novel therapeutic strategies.

关键词： astrocytes endoplasmic reticulum stress glial fibrillary acidic protein mutants metabolism misassembly misfolding neurodegeneration oxidative stress posttranslational modifications unfolded protein response

Short-term effects of different fire severities on soil properties and Pinus halepensis regeneration

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Journal of Forestry Research 2020年第4期31卷 1271-1282页

作者： Federico Romeo Pasquale A.Marziliano Maria belén Turrión Adele Muscolo Department of Agraria Mediterranea UniversityFeo di Vito89122 Reggio CalabriaItaly

Considering that diverse fire severities can affect soil properties differently,the aim of this study was to examine to what extent changes in soil properties caused by fire could condition seedling *** new approach is for identifying a new fire cause-effect chain to qualify the impacts of fire on soils with the purpose of using fire as a tool in forest management to favour Pinus halepensis *** study area was a reforested *** area which had been crossed by fire for78.8 ha,causing various degrees of *** forest was subdivided into three large areas according to the gravity of crown scorch,[low(LS),medium(MS)and high(HS)severity],on the basis of needle yellowing which usually occurs after exposure to direct *** showed significant differences in soil properties with respect to fire *** the HS area,total nitrogen and carbon were considerably reduced while ash and phosphorus contents significantly *** changes in soil properties,in particular to nutrient levels,affected *** regeneration,mainly the first year after the *** regeneration occurred in areas affected by moderate fire severity in which the temperatures reached increased the mineralization of soil organic matter with the consequent release of nutrients available for seedling ***,moderate fire severity suppressed the regeneration of grasses,reducing the interspecific *** of seedlings were inversely proportional to the density of *** the number was abundant(LS),the height was modest;conversely,where the number was low(HS),the greater hypsometric differentiation of pine seedlings was *** results suggest that moderate fire severity represents an environmental stress(hormesis)altering microscale conditions to increase pine germination and *** exposure of *** to a moderate environmental factor that is damaging at higher intensities,induces an adaptive

关键词： Ecophysiology Fire severity Pinus halepensis Post-fire regeneration Soil chemical properties