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Carbon-based solid lubricants:An overview

Friction 2025年第1期13卷 101-139页

作者： JoséDaniel Biasoli de Mello Laboratório de Tribologia e Materiais Universidade Federal de UberlândiaUberlândia 38408-100Brazil Laboratório de Materiais Universidade Federal de Santa CatarinaFlorianópolis 88040-900Brazil

Solid lubrication is an excellent option to reduce friction and wear in dry sliding conditions,as well as a secondary source of protection in fluid-lubricated *** the most widely used solid lubricants,carbon-based lubricants are among the most versatile for tribological *** reasons for this include their availability and their innate ability to adopt various *** crystalline ordering of carbon has been identified as the main factor governing its tribological *** work presents and discusses the most significant findings from an ongoing research program aimed at developing carbon-based solid *** this sense,several carbon-based materials with diverse levels of nanostructural order have been studied:three-dimensional(3D)crystalline graphite(GR);novel carbide-derived two-dimensional(2D)turbostratic carbon(CDC)produced from Fe–SiC(GSF)and B4C–Cr3C2(GBC)solid-state reactions;NH3 plasma-functionalized multilayer graphene(MLG);in situ fluorinated diamond-like carbon(DLC)(isfDLC);vertically aligned carbon nanotube(CNT)***,we present a brief description of the processing route for obtaining these materials,followed by their microstructural characterization and a synthesis of the most relevant aspects of tribological *** sliding tests in reciprocating motion were employed with different tribo-pair geometries,specimens and counter-body materials,varied surface topography,and diverse routes to add solid lubricants to the contact(vacuum impregnation of sintered steels,drop-casting,self-lubricating composites and vertically aligned films).The results provide a holistic view of the nature of the tribolayers formed by these ***,a new micro-Raman(µRaman)analysis technique for quantifying the point and line defects of the carbon present in tribolayers is used to correlate the lubrication and degradation mechanism of carbonaceous solid lubricants with their initial nanostructure and testing condit

关键词： carbon nanostructures solid lubrication defect quantification tribolayer micro-Raman(μRaman)spectroscopy

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Spherical quantum dot described by a scalar exponential potential under the influence of a linear electric field

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Communications in Theoretical Physics 2025年第2期77卷 172-175页

作者： K Bakke departamento de Física Universidade Federal da Paraíba

We study the confinement of a spinless charged particle to a spherical quantum dot under the influence of a linear electric field. The spherical quantum dot is described by a short-range potential given by the power-exponential potential. Then, by analysing the region near the spherical quantum dot centre, we discuss two cases where the energy levels can be obtained for s-waves and how the linear electric field modifies the spectrum of energy of the spherical quantum dot.

关键词： spherical quantum dot power-exponential potential short-range potential linear electric field

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Temperature sensing performance of Er^(3+):Yb^(3+)co-doped CaF_(2)ceramic powders using near-infrared light

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Journal of Rare Earths 2025年第2期43卷 253-261,I0001页

作者： Nikifor Rakov Francisco Matias Glauco S.Maciel IPCM-Ciencia dos Materiais Universidade Federal do Vale do Sao Francisco48902-300JuazeiroBABrazil Instituto de Fisica Universidade Federal Fluminense24210-346NiteroiRJBrazil

Luminescent materials for application in temperature sensing have caught a lot of interest in recent *** erbium(Er^(3+))-doped fluoride-based materials(EFM),which are readily accessible by near-infrared(NIR)excitation to produce efficient photon *** has been established that ytterbium(Yb^(3+))may improve the performance of EFMs in both bulk and nanostructured forms by energy transfer channels among rare-earth ions in interstitial *** this work,a comprehensive analysis of the Er^(3+):Yb^(3+):CaF_(2)crystalline structure,photoluminescence,and energy transfer from Yb^(3+)to Er^(3+)is presented for powders prepared by combustion *** Er^(3+):Yb^(3+):CaF_(2)powders display exceptional photon down-shift and up-conversion when exposed to NIR light(λ=975 nm).The luminescence spectral change of the NIR emission around 1.5μm,which corresponds to the Er^(3+)electronic transition ^(4)I_(13/2)→^(4)I_(15/2),was investigated in a temperature range of 298-423 K for application in temperature sensing of biological systems exploring the third biological *** luminescence intensity ratio technique was applied to the thermally coupled Stark sublevels of states^(4)I_(13/2)and^(4)I_(15/2)with the highest estimated temperature relative sensitivity being around 0.4%/K at 298 K.

关键词： Photoluminescence Frequency up-conversion Thermal sensor Rare-earth doped materials

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Impact of Zika virus non-structural protein mutations on hippocampal damage

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Neural Regeneration Research 2025年第8期20卷 2307-2308页

作者： Larissa M.G.Cassiano Roney S.Coimbra Neurogenômica/Imunopatologia Instituto RenéRachouFiocruzBelo HorizonteBrazil departamento de Bioquímica e Imunologia Instituto de Ciências BiológicasUniversidade Federal de Minas GeraisBelo HorizonteBrazil

The Zika virus(ZIKV),a member of the Flaviviridae family,attracted worldwide attention for its connection to severe neurological effects,notably microcephaly in newborns,first reported during the 2015 epidemic in ***,its impact goes beyond fetal and neonatal abnormalities,also affecting the central nervous system(CNS)in both children and adults,leading to enduring cognitive and behavioral impairments.

关键词： damage fetal neonatal

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SARS-CoV-2 proteins show great binding affinity to resin composite monomers and polymerized chains

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World Journal of Experimental Medicine 2025年第1期15卷 96-103页

作者： Pedro Henrique Sette-de-Souza Moan Jéfter Fernandes Costa Boniek Castillo Dutra Borges Faculdade de Odontologia Universidade de Pernambuco-campus ArcoverdeArcoverde 56503-146PernambucoBrazil Programa de Pós-Graduação em Saúde e desenvolvimento Socioambiental Universidade de Pernambuco-campus GaranhunsGaranhuns 55294-902PernambucoBrazil Programa de Pós-Graduação em Biologia Celular e Molecular Aplicada Universidade de Pernambuco-campus Santo AmaroRecife 50100-130PernambucoBrazil department of Odontologia Universidade Federal do Rio Grande do NorteNatal 59056-000Rio Grande do NorteBrazil Programa de Pós-Graduação em Ciências Odontológicas Universidade Federal do Rio Grande do NorteNatal 59056-000Rio Grande do NorteBrazil

BACKGROUND Due to saliva and salivary glands are reservoir to severe acute respiratory syndrome-coronavirus 2(SARS-CoV-2),aerosols and saliva droplets are primary sources of cross-infection and are responsible for the high human–human transmission of ***,there is no evidence about how SARSCoV-2 interacts with oral structures,particularly resin *** To evaluate the interaction of SARS-CoV-2 proteins with monomers present in resin composites using in silico *** Four SARS-CoV-2 proteins[*** protease,3C-like protease,papain-like protease(PLpro),and glycoprotein spike]were selected along with salivary amylase as the positive control,and their binding affinity with bisphenol-A glycol dimethacrylate,bisphenol-A ethoxylated dimethacrylate,triethylene glycol dimethacrylate,and urethane dimethacrylate was *** docking was performed using AutoDock Vina and visualised in Chimera UCSF *** best ligand–protein model was identified based on the binding energy(ΔG–kcal/moL).RESULTS Values for the binding energies ranged from-3.6 kcal/moL to-7.3 kcal/*** 3-monomer chain had the lowest binding energy(*** affinity)to PLpro and the glycoprotein ***-polymerised monomers and polymerised chains interacted with SARS-CoV-2 proteins via hydrogen bonds and hydrophobic *** findings suggest an interaction between SARS-CoV-2 proteins and resin *** SARS-CoV-2 proteins show affinity to non-polymerised and polymerised resin composite chains.

关键词： Composite resins COVID-19 SARS-CoV-2 dental restorations Molecular docking simulation dentistry

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Water Dynamics on Germinating Diaspores:Physiological Perspectives from Biophysical Measurements

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Plant Phenomics 2020年第1期2卷 389-404页

作者： J.P.Ribeiro-Oliveira M.A.Ranal M.A.Boselli Instituto de Ciências Agrárias Universidade Federal de UberlândiaAvenida João Naves deÁvila212138400-902 UberlândiaMinas GeraisBrazil Instituto de Biologia Universidade Federal de UberlândiaAvenida João Naves deÁvila212138400-902 UberlândiaMinas GeraisBrazil Instituto de Física Universidade Federal de UberlândiaAvenida João Naves deÁvila212138400-902 UberlândiaMinas GeraisBrazil

We demonstrated that classical biophysical measurements of water dynamics on germinating diaspores(seeds and other dispersal units)can improve the understanding of the germination process in a simpler,safer,and newer *** was done using diaspores of cultivated species as a biological *** calculate the water dynamics measurements(weighted mass,initial diffusion coefficient,velocity,and acceleration),we used the mass of diaspores recorded over germination *** mass of germinating diaspores has a similar pattern,independent of the physiological quality,species,or genetic improvement ***,the initial diffusion coefficient(related to imbibition per se),velocity,and acceleration(related to the whole germination metabolism)are influenced by species characters,highlighting the degree of genetic improvement and physiological *** in the inflection of velocity curves demonstrated each phase of germination sensu *** is no pattern related to the number of these phases,which could range between three and *** models can demonstrate initial velocity and velocity increments for each phase,giving an idea of the management of germinative *** finds demonstrated that germination is a polyphasic process with a species-specific pattern but still set by the degree of genetic improvement and(or)physiological quality of *** the biophysical measurements,velocity has the greatest potential to define the germination metabolism.

关键词： pattern acceleration germination

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Revealing the kinetics of Leishmania chagasi infection in the male genital system of hamsters

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Infectious Diseases of Poverty 2016年第1期5卷 261-265页

作者： Amanda P.N.Quintal Bruna C.Borges Paula C.Brígido Rebecca T.Silva Ana F.Notário Marlus A.Santos Maria A.de Souza Fernanda G.O.Nascimento Antônio V.Mundim Guilherme M.J.Costa André B.Vasconcelos Claudio V.da Silva Instituto de Ciências Biomédicas Universidade Federal de UberlândiaUberlândiaMinas GeraisBrasil Hospital Veterinário Universidade Federal de UberlândiaUberlândiaMinas GeraisBrasil departamento de Ciências Biomédicas Universidade Federal de Minas GeraisBelo HorizonteBrasil universidade de Uberaba UberabaMinas GeraisBrasil departamento de Imunologia–Instituto de Ciências Biomédicas Universidade Federal de UberlândiaCampus UmuaramaUberlândiaMGBrasil

Background:Leishmaniasis causes alterations and lesions in the genital system,which leads to azoospermia and testicular atrophy in animals during the chronic phase of the *** aim of this study was to reveal the kinetics of Leishmania chagasi infection in the genital system of male golden hamsters(Mesocricetus auratus).Methods:Animals were intraperitoneally inoculated with amastigotes from *** different time points animals were euthanized and genital organs processed for histo-pathological,qPCR,cytokines and testosterone detection ***:Our results showed a high parasite load in testis,followed by an increase of pro-inflammatory cytokines IL1-β,TNF-αand IFN-γ,and ***,IL-4 expression was upregulated and basal parasite persistence in testis was observed using the experimental ***:Extracellular amastigotes migrated to the epididymis posing as a potential major factor of parasite persistence and venereal transmission of *** infection in hamsters.

关键词： Leishmania chagasi Extracellular amastigotes Testis Epididymis Immune response Testosterone

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Brazilian savanna re-establishment in a monoculture forest:diversity and environmental relations of native regenerating understory in Pinus caribaea Morelet. stands

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Journal of Forestry Research 2015年第3期26卷 571-579页

作者： Gasto Viegas de Pinho Júnior AndréR. Terra Nascimento Barbara Tahara Valverde Lucas H. Clemente Elementary/High Schools in uberlndia UberlndiaMinas Gerais 38412-436 Brazil universidade federal de uberlndia UberlndiaMinas Gerais 38412-436 Brazil Avenida Ortizio Borges 2836 Bairro Santa MnicaUberlndia Minas Gerais 38412-436 Brazil

In this paper we analyze and compare natural regeneration in shrub-tree community in three areas below Pinus caribaea stands and a natural area （cerrado sensu stricto）. We also analyze the influence of biophysical and environmental variables on the distribution of regenerating shrub-tree species. The areas were analyzed and compared in relation to dispersal syndromes as well, being zoochory and anemochory the prevailing syndroms in the four areas. The sites below P. caribaea show a heterogeneous regen- eration with the number of species ranging from 18 to 42. We analyzed the influence of the biophysical and envi- ronmental variables performing a canonical correspon- dence analyses, being found significant values for variables distance from remnant and basal area. The species Si- paruna guianensis, Miconia albicans, Xylopia aromatica, Sclerolobium paniculatum, Casearia sylvestris and P. caribaea were the most importante ones in the four areas,

关键词： Native regeneration Cerrado Commercialforests Multivariate analysis Plant ecology

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The Abundance of the Remaining Mammalian Fauna and the Impacts of Hunting in a Biodiversity Hotspot’s Hotspot in the Atlantic Forest of North-Eastern Brazil

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Open Journal of Ecology 2025年第1期15卷 65-91页

作者： Éverton Renan de Andrade Melo José Ramon Gadelha Leandro Ricardo Rodrigues de Lucena Antonio Rossano Mendes Pontes IBAMA-SCEN Brasilia Brazil universidade federal de Pernambuco Recife Pernambuco Brazil universidade federal Rural de Pernambuco Serra Talhada Pernambuco Brazil Camaragibe Pernambuco Brazil Former Address: INPA-NAPRR-Boa Vista Roraima Brazil

Although hunting in the north-eastern Atlantic forest of Brazil began more than 500 years ago, no study to date has evaluated its impacts on the region’s mammalian fauna. For one year we carried out diurnal and nocturnal surveys using the Line Transect method in seven forest fragments varying from 7.32 ha to 469.76 ha, within a 4000 ha forest island archipelago, in Pernambuco State, Atlantic forest of northeastern Brazil. We calculated species density, population size, biomass and synergetic biomass, and recorded direct and indirect human impacts along the study transects. We recorded 44 mammalian species, of which 45.5% (n = 20) went extinct through hunting. The smallest forest fragment had the lowest richness, diversity, population size, and total biomass. It also had no synergetic biomass. The largest fragment had the highest richness, total density, and population size. There was a statistically significant relationship between fragment area and number of gunshots heard and suspended hunting platforms found;between population size and gunshots heard, suspended hunting platforms, free-roaming and feral dogs, and between total density and free-roaming and feral dogs. After more than 500 years of colonization hunting is still devastating, with larger fragments being linked to more hunters. Higher mammal abundances attracted more free-roaming and feral dogs, which have adapted to hunt wildlife on their own. Unless we protect every single forest fragment and create sustainable landscapes, we will not be able to save this hotspot’s hotspot.

关键词： Atlantic Forest Mammals Abundance Human Impact Extinction

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Oregano and Rosemary Essential Oils in Collagen Fiber and Polyvinyl Alcohol Films: Application as Biodegradable Active Packaging for Ready-to-Eat Meat Products

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Food and Nutrition Sciences 2025年第1期16卷 1-27页

作者： Suslin Raatz Thiel Cássio Poerschke Rodrigues José Dilson Francisco da Silva Mari Silvia Rodrigues de Oliveira Stephanie Reis Ribeiro Rosa Cristina Prestes Ernesto Hashime Kubota Roger Wagner Renius Mello department of Food Science and Technology Universidade Federal de Santa Maria Rio Grande do Sul Brazil

developing packaging using biomaterials offers a solution to the problem of solid plastic waste in urban areas. However, selecting suitable materials remains challenging, particularly when the packaging is intended for food products with high moisture content, such as meat. In response to this challenge, a novel film comprising a blend of collagen fiber and polyvinyl alcohol, supplemented with varying concentrations of oregano and rosemary essential oils, was developed. The mechanical properties, in vitro antioxidant activity, and chemical composition of these collagen fiber and polyvinyl alcohol films, enhanced with oregano and rosemary essential oils, were thoroughly characterized. The compounds γ-terpinene and ρ-cymene played a significant role in the antioxidant activity of the packaging. The impact of this active packaging on the quality of sliced mortadella was evaluated over 0, 3, 6, and 9 days of refrigeration. Time significantly influenced most of the variables examined. The concentration of essential oils (0%, 2%, 4%, and 6%) significantly affected the moisture level, water activity, pH, and Escherichia coli count in the packaged product. For lipid oxidation analysis, the type of essential oil proved significant, with oregano essential oil demonstrating superior activity. A pro-oxidant effect was noted in products with 6% rosemary essential oil. Packages containing essential oils from oregano and rosemary exhibited lower E. coli counts. Films enriched with essential oils showed a higher rate of biodegradation.

关键词： Lipid Oxidation Escherichia coli Principal Component Analysis Bioactive Compounds Shelf Life Mechanical Properties

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