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Mechanisms of neuroplasticity and brain degeneration: strategies for protection during the aging process

Neural Regeneration Research 2021年第1期16卷 58-67页

作者： Mariana Toricelli Arthur Antonio Ruiz Pereira guilherme souza abrao Helena Nascimento Malerba Julia Maia Hudson Sousa Buck Tania Araujo Viel Department of Physiological Sciences Santa Casa de Sao Paulo School of Medical SciencesSao PauloBrazil Laboratory of Neurobiology of Aging School of ArtsSciences and HumanitiesUniversidade de São PauloSao PauloBrazil

Aging is a dynamic and progressive process that begins at conception and continues until *** process leads to a decrease in homeostasis and morphological,biochemical and psychological changes,increasing the individual’s vulnerability to various *** growth in the number of aging populations has increased the prevalence of chronic degenerative diseases,impairment of the central nervous system and dementias,such as Alzheimer’s disease,whose main risk factor is age,leading to an increase of the number of individuals who need daily support for life *** theories about aging suggest it is caused by an increase of cellular senescence and reactive oxygen species,which leads to inflammation,oxidation,cell membrane damage and consequently neuronal ***,mitochondrial mutations,which are generated throughout the aging process,can lead to changes in energy production,deficiencies in electron transport and apoptosis induction that can result in decreased ***,increasing cellular senescence and the release of proinflammatory cytokines can cause irreversible damage to neuronal *** reports point to the importance of changing lifestyle by increasing physical exercise,improving nutrition and environmental enrichment to activate neuroprotective defense ***,this review aims to address the latest information about the different mechanisms related to neuroplasticity and neuronal death and to provide strategies that can improve neuroprotection and decrease the neurodegeneration caused by aging and environmental stressors.

关键词： cell senescence cell signaling cholinergic enriched environment long-term potentiation neurodegeneration neurogenesis neuroinflammatory neuronal death neuroprotection neurotophin

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Tribologically induced nanostructural evolution of carbon materials: A new perspective

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Friction 2024年第1期12卷 144-163页

作者： guilherme Oliveira NEVES Nicolás ARAYA Diego Berti SALVARO Thiago de souza LAMIM Renan Oss GIACOMELLI Cristiano BINDER Aloisio Nelmo KLEIN JoséDaniel Biasoli de MELLO Laboratório de Materiais Universidade Federal de Santa CatarinaSanta Catarina 88040-900Brazil Departamento de Ingeniería Mecánica Facultad de IngenieríaUniversidad del Bío-BíoConcepcion 4070-386Chile Universidad de Concepción Concepcion 4070-386Chile SENAI Innovation Institute for Laser Processing Santa Catarina 89218-153Brazil Universidade Federal de Uberlândia Minas Gerais 38408-100Brazil

Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes *** the macroscale,these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem *** a recently developed advanced Raman analysis on the tribolayers,it was possible to quantify the contactinduced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants,from graphite and carbide-derived carbon particles to multi-layer graphene and carbon *** addition,these materials were tested under various dry sliding conditions,with different geometries,topographies,and solid-lubricant application *** of the initial tribosystem conditions and allotrope level of atomic ordering,there is a remarkable trend of increasing the point and line defects density until a specific saturation limit in the same order of magnitude for all the materials tested.

关键词： carbon nanostructures tribology Raman spectroscopy defects quantification tribolayer solid lubrication

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Urea breath test for Helicobacter pylori infection in adult dyspeptic patients: A meta-analysis of diagnostic test accuracy

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World Journal of Gastroenterology 2024年第6期30卷 579-598页

作者： Fabian Fellipe Bueno Lemos Caroline Tianeze de Castro Marcel Silva Luz Gabriel Reis Rocha Gabriel Lima Correa Santos Luís guilherme de Oliveira Silva Mariana Santos Calmon Cláudio Lima souza Ana Carla Zarpelon-Schutz Kádima Nayara Teixeira Dulciene Maria de Magalhães Queiroz Fabrício Freire de Melo Instituto Multidisciplinar em Saúde Universidade Federal da BahiaVitória da Conquista 45029-094BahiaBrazil Instituto de Saúde Coletiva Universidade Federal da BahiaSalvador 40110040BahiaBrazil Campus Toledo Universidade Federal do ParanáToledo 85919-899ParanáBrazil Laboratory of Research in Bacteriology UFMGBelo Horizonte 30130-100Minas GeraisBrazil

BACKGROUND Helicobacter pylori(***)infection has been well-established as a significant risk factor for several gastrointestinal *** urea breath test(UBT)has emerged as a leading non-invasive method for detecting *** numerous studies confirming its substantial accuracy,the reliability of UBT results is often compromised by inherent *** findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of *** *** To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for *** infection in adult patients with *** We conducted an independent search of the PubMed/MEDLINE,EMBASE,and Cochrane Central databases until April *** search included diagnostic accuracy studies that evaluated at least one of the index tests(^(13)C-UBT or ^(14)C-UBT)against a reference *** used the QUADAS-2 tool to assess the methodo-logical quality of the *** utilized the bivariate random-effects model to calculate sensitivity,specificity,positive and negative test likelihood ratios(LR+and LR-),as well as the diagnostic odds ratio(DOR),and their 95%confidence *** conducted subgroup analyses based on urea dosing,time after urea administration,and assessment *** investigate a possible threshold effect,we conducted Spearman correlation analysis,and we generated summary receiver operating characteristic(SROC)curves to assess ***,we visually inspected a funnel plot and used Egger’s test to evaluate publication *** both as reliable diagnostic tools in clinical *** In summary,our study has demonstrated that ^(13)C-UBT has been found to outperform the ^(14)C-UBT,making it the preferred diagnostic ***,our results emphasize the significance of carefully considering urea dosage,assessment timing,and measurement techniques for both tests to enh

关键词： Helicobacter pylori Urea breath test Diagnosis Diagnostic test accuracy Meta-analysis

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Trends of stellar entropy along stellar evolution

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Research in Astronomy and Astrophysics 2016年第2期16卷 1-12页

作者： Marcio guilherme Bronzato de Avellar Rodrigo Alvares de souza Jorge Emesto Horvath Instituto de Astronomia Geofísica e Ciencias Atmosféricas-Universidade de Sao PauloRua do Matao1226

This paper is devoted to discussing the difference in the thermodynamic entropy budget per baryon in each type of stellar object found in the Universe. We track and discuss the actual decrease of the stored baryonic thermodynamic entropy from the most primitive molecular cloud up to the final fate of matter in black holes, passing through evolved states of matter as found in white dwarfs and neutron stars. We then discuss the case of actual stars with different masses throughout their evolution, clarifying the role of the virial equilibrium condition for the decrease in entropy and related issues. Finally, we discuss the role of gravity in driving the composition and the structural changes of stars with different Main Sequence masses during their evolution up to the final product. Particularly, we discuss the entropy of a black hole in this context arguing that the dramatic increase in its entropy, differently from the other cases, is due to the gravitational field itself.

关键词： stars formation -- stars neutron -- black holes

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Ultrastructural analysis of sperm from the genus Idarnes(Hymenoptera:Chalcidoidea,Sycophaginae)

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BIOCELL 2022年第1期46卷 275-283页

作者： KHESLLER PATRÍCIA OLAZIA JULIANA souza DA SILVA guilherme SIRIMARCO DE souza TONELLI SÔNIA NAIR BÁO Departamento de Biologia Celular Instituto de Ciências BiológicasUniversidade de BrasíliaBrasíliaBrazil Instituto de Ciências da Saúde Coordenação de Ciências BiológicasUniversidade Paulista UNIPBrasíliaBrazil

In this study,the sperm ultrastructure of three species of Idarnes genus was investigated using light and transmission electron *** morphology of the three species was similar to that of most Chalcidoidea,with helicoidally twisted nucleus and *** head region consists of an acrosome and a nucleus;the nucleus-flagellum transition region characterized by the presence of mitochondrial derivatives and the centriolar adjunct;a flagellum region,which includes the axoneme with microtubular arrangement 9+9+2 and two mitochondrial ***,the sperm of these three species exhibit features that discriminate one species from each other:(1)only one species,Idarnes sp.2(carme group)exhibited an extracellular sheath surrounding the anterior portion of the nucleus,which extends to the anterior region of the flagellum,but it did not present filaments;(2)the acrosome in the three species was quite different,Idarnes sp.1 and Idarnes sp.2(carme group)has two compartments(acrosomal and subacrosomal vesicles)while Idarnes sp.3(flavicollis group)has a third compartment(perforatorium);(3)the centriolar adjunct elongated and its location among the mitochondrial derivatives is similar for the three species analyzed;(4)mitochondrial derivatives differ between the species,with triangular(Idarnes sp.1 and sp.3)and elongated or flat shaped(Idarnes sp.2)*** data shows that sperm structure may differ within the same genus and confirms the potential of these cells in phylogenetic and taxonomic analyses in the Chalcidoidea superfamily,as well as in Hymenoptera in general.

关键词： Chalcidoidea Idarnes genus Insect sperm Sperm ultrastructure Fig wasps

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Characterization of Read/Write Head Shield Asperities in Hard Disk Drives

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Materials Sciences and Applications 2023年第9期14卷 439-457页

作者： guilherme Parente souza Western Digital Storage Technologies (Thailand) Ltd. Ayutthaya Thailand

A new way to characterize asperities on metallic surfaces at the nanometer scale is proposed. Asperities are often treated using conventional statistical descriptors such as average and root mean square roughness, which do not provide adequate mechanistic insight into surface defect formation and mitigation. The new rationale revolves around developing a mathematical description of the evolution of the area occupied by asperities at each height slice on a topography image, with direct implications on how asperity instances are tracked and their risk of breakage leading to potential exposure and degradation of the metal surface upon thermo-mechanical stresses during the operation of read/write heads is assessed. The technique was shown to be disruptive by surpassing all other surface quality metrics, such as conventional roughness and static area % asperity at 0.5 nm height, in its ability to statistically differentiate surfaces coming from various manufacturing process iterations tailored to produce different surface conditions in the hard disk drive industry. A theoretical formulation proposing that the static asperity technique is fundamentally insufficient, is presented and validated experimentally.

关键词： DLC AFM Surface Characterization Thin Film HDD

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Dipeptidyl peptidase 4(DPP4),adipose inflammation,and insulin resistance:is it time to look to the hepatocyte?

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Hepatobiliary Surgery and Nutrition 2018年第6期7卷 499-500页

作者： Wellington S.Silva Júnior Maria das Gracas C.souza Luiz guilherme Kraemer-Aguiar Endocrinology Discipline Faculty of MedicineCenter of NaturalHumanHealthand Technology SciencesFederal University of Maranhao(UFMA)PinheiroMABrazil Laboratory for Clinical and Experimental Research on Vascular Biology(BioVasc) Biomedical CenterState University of Rio de Janeiro(UERJ)Rio de JaneiroRJBrazil Postgraduate Program in Clinical and Experimental Physiopathology(FISCLINEX) Faculty of Medical SciencesUERJRio de JaneiroRJBrazil Endocrinology Department of Internal MedicineFaculty of Medical SciencesUERJRio de JaneiroRJBrazil

Dipeptidyl peptidase 4(DPP4),also known as adenosine deaminase binding protein or cluster of differentiation 26(CD26),is a serine exopeptidase able to inactivate peptides composed of proline,hydroxyproline,or alanine as the penultimate *** has a strong capacity to act in various peptides and is also widely expressed in many specialized cell types,such as endothelial cells,macrophages,and *** its physiological aspects,DPP4 inactivates the glucagon-like peptide-1(GLP-1),an incretin secreted by the gastrointestinal tract(1).Based on the antidiabetic actions of this incretin,several DPP4 inhibitors(named as gliptins)were launched in the market and are being in use for the treatment of type 2 diabetes(1).It is noteworthy that DPP4 also inactivate some cytokines,chemokines,and neuropeptides involved in inflammation,immunity,and vascular function(2).

关键词： inflammation immunity peptidase

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Does landscape context affect pollinationrelated functional diversity and richness of understory flowers in forest fragments of Atlantic Rainforest in southeastern Brazil?

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Ecological Processes 2020年第1期9卷 737-748页

作者： Karoline Baptista de Lima Patrícia Alves Ferreira Milton Groppo Renato Goldenberg Emerson Ricardo Pansarin Roxana Cardoso Barreto guilherme Peres Coelho Yago Barros-souza Danilo Boscolo Biology Department Faculty of PhilosophySciences and LettersUniversity of São PauloRibeirão PretoSP 14040-901Brazil National Institute of Science and Technology in Interdisciplinary and Transdisciplinary Studies in Ecology and Evolution(IN-TREE) SalvadorBrazil Botany Department Biological Science SectorParanáFederal UniversityCuritibaPR 81531-970Brazil Botany Department Biological Science CenterPernambuco Federal UniversityRecifePE 50670-420Brazil Institute of Bioscience Rio Grande do Sul Federal UniversityPorto AlegreRS 90040-060Brazil Botany Department Federal University of São CarlosSão CarlosSP 13565-905Brazil.

Background:How landscape modifications affect functional diversity of floral characteristics pertinent to pollinators is poorly *** possess functional traits that sometimes coevolved with pollinators,crucial for the maintenance of both pollinator and plant *** evaluated how richness and functional diversity of available understory flowers respond to forest cover and landscape heterogeneity in a multiscale *** in bloom were sampled from 25 landscapes in the understory of Atlantic Forest fragments in *** were classified into functional groups regarding flower characteristics relevant to *** heterogeneity and forest cover were measured in buffers ranging from 200 to 2000 m from sampling units and their correlation with plant richness and functional diversity was assessed using generalized linear models and further model selection through Akaike’s second-order information ***:Plants’richness and functional diversity were affected negatively by forest *** former responded to forest cover at a regional scale while the latter responded at a local *** landscape heterogeneity increased richness and functional ***:Our results showed that forest cover and landscape heterogeneity are important to support biodiversity related to pollination,mostly due to the availability of diversified resources and nesting sites associated to different land-uses for pollinators and flowering plant *** findings should highlight,along with forest cover,landscape heterogeneity as an environmental management priority in rural tropical areas for mitigating the loss of plant biodiversity and enhancing ecosystem functioning.

关键词： Functional diversity Pollination Landscape heterogeneity Forest cover Understory plant community

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Evaluation of Impairment Caused by MPEG Video Frame Loss

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Engineering（科研） 2017年第5期9卷 493-503页

作者： Carlos Alexandre Gouvea da Silva guilherme Fernandes de souza Miguel Joao guilherme Sauer Carlos Marcelo Pedroso Department of Electrical Engineering Federal University of ParanaCuritibaBrazil

This article presents a study on the impact of video frame losses on the quality perceived by users. Video compression standards, such as MPEG, use a sequence of frames called Group of Pictures (GOP), which is a video compression method which a frame is expressed in terms of one or more neighboring frames. This dependence between frames impacts directly in the quality because a loss of a reference frame prevents the decoding of other frames in GOP, thereby reducing the user-perceived quality. The assessment of quality in this article is estimated by Peak Signal Noise Ratio (PSNR), which compares the original and the received images. Computer simulations were used to show that the degradation on the quality may vary for different patterns of GOPs and type of lost frames.

关键词： MPEG-4 Video Streaming PSNR Frame Loss

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Physical Properties and Heat Transfer of Tectona grandis L.f. Wood

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Journal of Environmental Science and Engineering(B) 2012年第12期1卷 1303-1310页

作者： Joao Vicente de Figueiredo Latorraca Gilmar Correia Silva Luiz guilherme souza Lima Department of Forest Products Forest Institute Federal Rural University of Rio de Janeiro BrazilSeropedica 23890-000 Department of Plant Science and Zootechny State University of Southwest BahiaBrazil Vit6ria da Conquista 45083-900

Tectona grandis L.f. （teak） is native to the Indian subcontinent and southeast Asia, and today is grown in almost every tropical region, for the physical and mechanical properties of its wood. Also, important qualitative aspects render it one of the most expensive wood species in the world. This work presents a study about the physical properties and heat transfer of T. grandis wood from plantations in ***, Mato Grosso, Brazil. Six trees planted at three different intervals were used--two from each planting density--selected at random and with good phytosanitary characteristics, as well as having representative diameters and heights. The following properties were determined： basic and apparent densities, volume contraction, heat transfer and fiber saturation point. The basic and apparent mean general density of the samples was 0.48 g/cm3 and 0.55 g/cm3, respectively. The mean volume contraction of the teak wood was 8.57%. With decreased levels of wood humidity, loss of volume and planting effects were not significant at 5% probability. Mean heat transfer was 7.3 h/cm and the wood fiber saturation point was 17.25%, below the range found in literature, and there was no influence of the planting density on this property. According to the results, it was concluded that planting density significantly influenced the base density of the wood; the same effect does not occur for the other physical properties, and with respect to heat transfer, the wood was considered difficult to dry.

关键词： Wood material science wood behavior wood drying Tectona grand& teak.

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