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Investigating local corrosion processes of magnesium alloys with scanning probe electrochemical techniques: A review

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Journal of Magnesium and Alloys 2022年第11期10卷 2997-3030页

作者： Mara Cristina Lopes de oliveira Rejane Maria Pereira da Silva Ricardo M.Souto Renato Altobelli Antunes Federal University of ABC Center for EngineeringModeling and Applied Social SciencesAv.Dos Estados500109210-580Santo AndréSP Brazil Instituto de Pesquisas Energéticas e Nucleares IPEN/CNENAv.Prof.Lineu Prestes2242São PauloBrazil Institute of Material Science and Nanotechnology University of La LagunaP.O.Box 456La LagunaTenerife 38200Spain

The study of corrosion of magnesium and its alloys has emerged a hot topic in the applications of lightweight structural materials. The inherently high electrochemical activity of bare magnesium surfaces still lacks a convincing mechanism to describe the observed experimental characteristics, and it has prompted the development of various types of protective coatings with the aim of slowing metal dissolution. In recent years, new instruments and techniques have been developed to study with spatial resolution the local corrosion processes that occur in metallic materials in general, and for magnesium and its alloys in particular, both for bare surfaces and coated. Scanning microelectrochemical techniques, such as local electrochemical impedance spectroscopy(LEIS), scanning electrochemical microscopy(SECM), scanning vibrating electrode technique(SVET), scanning ion-selective electrode technique(SIET) and scanning Kelvin probe(SKP) can provide information about the local electrochemical activity of metallic surfaces. In the present work, the applications of these techniques in corrosion studies of magnesium and its alloys are reviewed. Assessment of corrosion mechanisms, barrier properties of conventional coatings and active corrosion behavior of self-healing coatings are examined. Limitations and future developments in this area are discussed.

关键词： Magnesium alloys LEIS SECM SVET SIET SKP

Morphological traits explain the individual position within resource-consumer networks of a Neotropical marsupial

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Current Zoology 2024年第4期70卷 453-464页

作者： Nicholas F.de Camargo Hernani F.M.de oliveira Juliana F.Ribeiro Amabilio J.A.de Camargo Emerson M.Vieira Laboratorio de Ecologia de Vertebrados Departamento de EcologiaInstituto de Ciencias BiologicasUniversidade de BrasiliaCP 04457BrasiliaDF70910-900Brazil departamento de Zoologia Setor de Ciencias BiologicasUniversidade Federal do ParanaAvenida Coronel Francisco Heraclito dos Santos100CuritibaPR81531980Brazil Embrapa Cerrados Rodovia BR020km 18CP 08223PlanaltinaDE73310-970Brazil

Knowledge regarding the influence of individual traits on interaction patterns in nature can help understand the topological role of individuals within a network of intrapopulation *** tested hypotheses on the relationships between individuals'positions within networks(specialization and centrality)of 4 populations of the mouse opossum Gracilinanus agilis and their traits(i.e.,body length,body condition,tail length relative to body length,sex,reproductive condition,and botfly parasitism)and also seasonal effects in the Brazilian *** with lower body length,better body condition,and relatively shorter tail were more specialized(i.e.,less connected within the network).Individuals were also more specialized and less connected during the warm-wet *** relationship between individuals'position in the network and body traits,however,was independent of *** propose that specialization may arise not only as a result of preferred feed-ing strategies by more capable individuals(i.e.,those with better body condition and potentially prone to defend and access high-quality food resources)but alsobecause of morphological ***/younger individuals(consequently with less experience in foraging)and short-tailed individuals(less skilled to explore the vertical strata of the vegetation)would feed only on a subset of the available food resources and consequently become more ***,individuals are more specialized during the warm-wet season because of high competition(population-dense period)and higher ecological opportunities(resource-rich period).Therefore,our study reveals the relevance of individual traits inshaping interactionpatternsandspecialization inpopulations.

关键词： bodytraits centrality Cerrado Gracilinanus agilis seasonality specialization.

Behavior of wood basic density according to environmental variables

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Journal of Forestry Research 2022年第2期33卷 497-505页

作者： Gabriel Marcos Vieira oliveira JoséMárcio de Mello Carlos Rogério de Mello JoséRoberto Soares Scolforo Eder Pereira Miguel Thiago Campos Monteiro Brazil Institute of Agricultural and Forestry defense of Espírito Santo(IDAF) Av.Lourival Lugon Moulinnº300CentroJerônimo MonteiroES CEP:29.550-000Brazil department of Forestry Sciences Universidade Federal de Lavras-UFLACaixa Postal 3037LavrasMG CEP:37.200-000Brazil Engineering department Universidade Federal de Lavras-UFLACaixa Postal 3037LavrasMG CEP:37.200-000Brazil Forestry Engineering department Faculdade de TecnologiaUniversity of Brasilia-UnBCampus Universitário Darcy RibeiroCaixa Postal 4357Asa Norte-BrasíliaDF CEP:70910-900Brazil department of Forestry Engineering and Technology Universidade Federal do Paraná-UFPRAv.Pref.Lothário Meissner632Jardim BotânicoCuritibaPR CEP:80.210-170Brazil

The relationships between climate conditions and wood density in tropical forests are still poorly *** quantify spatial dependence of wood density in the state of Minas Gerais(MG,Brazil),map spatial distribution of density,and correlate density with climate variables,we extracted data from the Forest Inventory of Minas Gerais for 1988 trees scaled throughout the territory and measured wood density of discs removed from the *** variables were extracted from the database of the Ecological-Economic Zoning of Minas *** spatial analysis,tree densities were measured at 44 georeferenced sampling *** data were subjected to exploratory analysis,variography,cross-validation,model selection,and ordinary *** relationships between wood density and environmental variables were calculated using dispersion matrices,linear correlation,and *** density proved to be highly spatially dependent,reaching a correlation of 96%,and was highly continuous over a distance of 228 *** distribution of wood density followed a continuous gradient of 514-659 kg m^(−3),enabling corre-lation with environment *** was correlated with mean annual precipitation(−0.57),temperature(0.63),and evapotranspiration(0.83).Geostatistical methods proved useful in predicting wood density in native tropical forests with different climate *** results confirmed the sensitivity of wood density to climate change,which could affect future carbon stock in forests.

关键词： Biomass Climate variables Geostatistics Hardwood Forest inventory Minas Gerais

Changes in calcium accumulation and utilization efficiency and their impact on recycling,immobilization,and export across the oil palm cycle

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Oil Crop Science 2024年第3期9卷 143-150页

作者： Ismael de Jesus Matos Viégas Luma Castro de Souza Eric Victor de oliveira Ferreira Milton Garcia Costa Glauco André dos Santos Nogueira Vitor Resende do Nascimento Candido Ferreira de oliveira Neto Capanema Campus Federal Rural University of the Amazon(UFRA)Av.Barao de CapanemaCaixa D'agua5514-6434ParaBrazil Center of Agricultural and Environmental Sciences Federal University of Maranhao(UFMA)ChapadinhaBR-222km 04SNBoa Vista65500000MaranhaoBrazilc Capitao Poço Campus Federal Rural University of the Amazon(UFRA)Tv.Pau AmareloS/n-Vila Nova68650-000Capitao PoçoParaBrazil department of Soil Science Sao Paulo State University(Unesp)School of Agricultural and Veterinarian SciencesJaboticabalVia de Acesso Prof.Paulo Donato CastelaneCastellane-S/N-Vila Industrial14884-900Sao PauloBrazil Institute of Agricultural Sciences(ICA) Federal Rural University of the Amazon(UFRA)Estr.Principal da Ufra2150Curio-Utinga66077-580BelemParaBrazil

Effective calcium(Ca)management is crucial for optimizing oil palm cultivation and enhancing crop *** study aimed to gain insights into the dynamics of Ca concentration,accumulation,exportation,immobilization,and recycling in various oil palm organs relative to plant *** experiment was conducted at the Agropalma enterprise site in the northeastern region of Para State,Brazil,evaluating seven plant age treatments:2,3,4,5,6,7,and 8 years *** a completely randomized design with four *** results demonstrated an age-related increase in Ca concentration in petioles,rachis,arrows,male inflorescences,peduncles,and ***,Ca accumulation exhibited an upward trend in all organs with progressing plant ***,the study revealed an enhanced Ca use efficiency across all plant organs in correlation with the age of oil palm *** findings underscore the dynamic nutritional demands of oil palm,influencing Ca immobilization,cycling,and export throughout its developmental stages.

关键词： Elaeis guineensis Jacq Ca cycling Ca export Ca immobilization Ca use efficiency Plant nutrition Amazon

Vitellogenin content in fat body and ovary homogenates of workers and queens of Melipona quadrifasciata anthidioides during vitellogenesis

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Insect Science 2012年第2期19卷 213-219页

作者： Vagner Tadeu Paes de oliveira Bruno Berger Carminda da Cruz-Landim Zila Luz Paulino Simoes departamento de Biologia Instituto de Biociencias de Rio ClaroUNESP-Univ.Bela VistaRio ClaroSao Paulo departamento de Biologia FFFL de Ribeirao PretoUniversidade de Sao PauloUSPSao PauloBrazil

Vitellogenin （Vg） is an egg yolk protein that is produced primarily in the fat body of most female insects. In the advanced social structure of eusocial honeybees, the presence of the queen inhibits egg maturation in the workers＇ ovaries. However in the stingless bee Melipona quadrifasciata, the workers always develop ovaries and lay a certain amount of eggs while provisioning the brood cells with larval food during what is known as the worker nurse phase. The present work is a comparative study of the presence of Vg in homogenates of the fat bodies and ovaries of the nurse workers, and the virgin and physogastric queens of M. quadrifasciata. The presence of Vg was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and irnmunoblotting using Apis mellifera anti-egg antibody. Vg was not detected in the fat bodies or ovaries of the workers, but it was found in the ovaries of virgin and physogastric queens and in the fat body ofphysogastric queens. The results are discussed, taking into account the reproductive state of the individuals and the other possible roles of Vg, such as a storage protein for metoabolism of other organs.

关键词： egg yolk electrophoresis immunoblotting nurse worker stingless bee virginand physogastric queen

Paleoproterozoic juvenile magmatism within the northeastern sector of the Sao Francisco paleocontinent:Insights from the shoshonitic high Ba-Sr Montezuma granitoids

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Geoscience Frontiers 2020年第5期11卷 1821-1840页

作者： Samuel Moreira Bersan Alice Fernanda de oliveira Costa Andre Danderfer Francisco Roberio de Abreu Cristiano Lana Glaucia Queiroga Craig Storey Hugo Moreira Universidade Federal de Ouro Preto Programa de Pos-graduacaoDepartamento de GeologiaCampus Morro do CruzeiroOuro PretoMGCEP 35400-000Brazil Universidade Federal de Ouro Preto Departamento de GeologiaCampus Morro do CruzeiroOuro PretoMGCEP 35400-000Brazil Sustain Geologia Ltda Teresa M.Valadares 503/502Belo HorizonteMGCEP 30575-160Brazil University of Portsmouth School of Earth and Environmental SciencesBurnaby BuildingBurnaby RoadPortsmouthPO13QLUK

New,integrated petrographic,mineral chemistry,whole rock geochemical,zircon and titanite UPb geochronology,and zircon Hf isotopic data from the Montezuma granitoids,as well as new geochemical results for its host rocks represented by the Corrego Tingui Complex,provides new insights into the late-to post-collisional evolution of the northeastern Sao Francisco paleocontinent.U-Pb zircon dates from the Montezuma granitoids spread along the Concordia between ca.2.2 Ga to 1.8 Ga and comprise distinct *** I have crystallization ages between ca.2.15 Ga and 2.05 Ga and are interpreted as inherited *** II zircon dates vary from 2.04 Ga to1.9 Ga and corresponds to the crystallization of the Montezuma granitoids,which were constrained at ca.2.03 Ga by the titanite U-Pb *** age zoning is common within the ca.1.8 Ga Group III zircon ages,being related to fluid isotopic re-setting during the Espinhaco rifiting ***εHf(t)analysis show dominantly positive values for both Group I(-4 to+9)andⅡ(-3 to+8)zircons and TDM2 model ages of 2.7-2.1 Ga and 2.5-1.95 Ga,***,the Montezuma granitoids are weakly peraluminous to metaluminous magnesian granitoids,enriched in LILES and LREE,with high to moderate Mg#and depleted in some of the *** lithochemical signature,added to the juvenile signature of both inherited and crystallized zircons,allowed its classification as a shoshonitic high Ba-Sr granitoid related to a late-to post-collisional lithosphere delamination followed by asthenospheric *** this scenario,the partial melting of the lithospheric mantle interacted with the roots of an accreted juvenile intra-oceanic arc,being these hybrid magma interpreted as the source of the Montezuma *** Corrego Tingui Complex host rocks are akin to a syn-to late-collisional volcanic arc granitoids originated from the partial melting of ancient crustal *** results presented in this study have revealed the occurrence of j

关键词： Zircon U–Pb-Hf Titanite U–Pb High Ba–Sr Late-to post-collisional Sao Francisco paleocontinent

Curcumin in inflammatory bowel diseases:Cellular targets and molecular mechanisms

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BIOCELL 2023年第11期47卷 2547-2566页

作者： AMYLLY SANUELLY DA PAZ MARTINS MARLA de CERQUEIRA ALVES ORLANDO ROBERTO PIMENTEL de ARAÚJO FABIANA oliveira DOS SANTOS CAMATARI MARÍLIA oliveira FONSECA GOULART FABIANA ANDRÉA MOURA Rede Nordeste de Biotecnologia(RENORBIO) Instituto de química e BiotecnologiaUniversidade Federal de Alagoas(UFAL)Maceió57072-900Brasil Programa de Pós-graduação em Nutrição(PPGNUT) Faculdade de Nutrição(FANUT)Universidade Federal de Alagoas(UFAL)Maceió57072-900Brasil Programa de Pós-Graduação em Química e Biotecnologia(PPGQB) Instituto de química e BiotecnologiaUniversidade Federal de Alagoas(UFAL)Maceió57072-900Brasil Colegiado de Nutrição Universidade de Pernambuco(UPE)Campus PetrolinaPernambuco56328-900Brasil Programa de Pós-Graduação em Ciências da Saúde(PPGCS) Instituto de Ciências da SaúdeUniversidade Federal de Alagoas(UFAL)Maceió57072-900Brasil Programa de Pós-graduação em Ciências Médicas(PPGCM) Faculdade de MedicinaUniversidade Federal de Alagoas(UFAL)Maceió57072-900Brasil

Curcumin,a natural product,has exhibited promising effects in both animal models and clinical trials,interacting with a multitude of factors linked to Inflammatory Bowel Disease(IBD).These factors encompass cytokines,oxidative stress-associated enzymes,and modulation of the intestinal ***,curcumin has demonstrated therapeutic potential in animal models of colitis,wherein it exerts a negative regulatory influence on pivotal signaling pathways such as PI3/Akt,JAK/STAT,andβ-***,it inhibits the expression of proinflammatory enzymes and co-stimulatory molecules(including RANKL,ICAM-1,CD205,CD256,TLR4,among others),while curbing immune cell chemotaxis,thereby attenuating the characteristic neutrophil infiltration observed in *** facet of curcumin’s action involves its modulation of the intestinal ***,the microbiota itself contributes to beneficial biotrans formations of curcumin,thereby enhancing its effectiveness in IBD *** a clinical front,curcumin has demonstrated the ability to induce clinical and/or endoscopic remission without any reported toxic ***,curcumin warrants consideration as an adjunctive therapy in IBD *** clinical investigations should concentrate on meticulously evaluating curcumin’s impact on these precise therapeutic targets.

关键词： Curcuminoids Polyphenols CDAI scores Ulcerative colitis Antioxidant

Increasing analyzable steel thickness for thin layer activation experiments

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Nuclear Science and Techniques 2020年第3期31卷 35-44页

作者： Joao Francisco de oliveira Antunes Mauro Lucio Borges Lemos Michel de Almeida Franca Julio Cezar Suita Celso Marcelo Franklin Lapa Instituto de Engenharia Nuclear Rio de Janeiro 21941-614Brazil Programa de Engenharia Nuclear-COPPE/UFRJ Riode Janeiro 21941-450Brazil

The thin layer activation technique(TLA)is very effective in wear analysis for tribological systems where disassembly is costly or *** its development in the 1970s,TLA has been applied through direct irradiation of solid targets using ionizing particle beams to obtain an activation with a specific *** profile is then used to measure wear in a variety of *** experiments rely heavily on how deep the normalized activation *** of 30μm to 50μm are obtained for constant activation by the standard method,which for many experiments is ***,many others would benefit greatly from a 300μm constant activation layer,such as high-performance engines,softer alloys(brakes),and oil transport *** this aim was the goal of this ***,we needed to find an adequate irradiation line for the TLA ***,another technique/system was developed(the Attenuation Wheel),which would bring the depth of constant activation from 50μm to 300μm.

关键词： Thin layer activation Wear Proton beam Attenuation wheel

Stepped machine learning for the development of mineral models: Concepts and applications in the pre-salt reservoir carbonate rocks

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Energy and AI 2021年第1期3卷 167-179页

作者： Lucas Abreu Blanes de oliveira Luiz Felipe Niedermaier Custodio Thais Bortotti Fagundes Carina Ulsen Cleyton de Carvalho Carneiro Petrobras–Petroleo Brasileiro S.A. Avenida Henrique Valadares 28CentroRio de Janeiro20231-030 Rio de JaneiroBrazil Universidade de Sao Paulo USPEscola PolitecnicaPraça Narciso de AndradeVila MathiasSantosSão Paulo 11013-560Brazil

Understanding rock mineralogy is essential for formation evaluation,improving the calculation of porosity and hydrocarbon *** primary method to obtain the mineralogy from a well is by applying a model to the geochemical tool’s chemical ***,creating a mineralogical model presents challenges such as the minerals’chemical composition and the decision to include a mineral in the *** traditional application of machine learning can make mineral models less realistic since conventional training is developed based on a set of minerals with different occurrences,lowering some minerals’*** present research proposes the stepped machine learning(SML),a stepped way to use machine learning to create a mineralogical model from chemical and mineralogical data.A database was assembled with the elemental concentration obtained with XRF analyses and the mineral concentrations obtained with XRD *** chemical elements were Al,Ca,Fe,K,Mg,Mn,Na,Si,and *** minerals were calcite,dolomite,quartz,clays,K-feldspar,plagioclase,and *** algorithms were tested:MLP,GAN,Random Forest,and XGBoost,with XGBoost showing the best *** was applied,where a mineral model results are used to train a subsequent *** allowed for a significant improvement in some models,notably to clays with an increase in R 2 from 0.597 to 0.853,quartz an increase from 0.673 to 0.869,and calcite,from 0.758 to 0.862.A decrease in the mean squared error of these minerals’models was also *** model was applied to the geochemical logs from three wells drilled in the Brazilian pre-salt,and the results were compared with XRD *** SML model was able to honor the mineral concentrations for different *** is demonstrated that the integration between machine learning tools and geological knowledge in SML was crucial for creating a representative mineralogical model.

关键词： minerals quartz reservoir