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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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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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Tailoring the properties of quantum dot-micropillars by ultrafast optical injection of free charge carriers

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Light(Science & Applications) 2021年第11期10卷 2083-2097页

作者： Emanuel Peinke Tobias Sattler guilherme M.Torelly Patricia L.souza Sylvain Perret Joel Bleuse Julien Claudon Willem L.Vos Jean-Michel Gerard UniversitéGrenoble Alpes CEAIRIG-PHELIQS“Nanophysique et Semiconducteurs”groupF-38000GrenobleFrance LabSem-CETUC Pontificia Universidade Catolica do Rio de JaneiroRio de Janeiro22451-900Brazil Complex Photonic Systems(COPS) MESA+Institute for NanotechnologyUniversity of TwenteP.O.Box 2177500 AEEnschedethe Netherlands

We review recent studies of cavity switching induced by the optical injection of free carriers in micropillar cavities containing quantum *** the quantum dots as a broadband internal light source and a streak camera as detector,we track the resonance frequencies for a large set of modes with picosecond time *** report a record-fast switch-on time constant(1.5 ps)and observe major transient modifications of the modal structure of the micropillar on the 10 ps time scale:mode crossings are induced by a focused symmetric injection of free carriers,while a lifting of several mode degeneracies is observed when off-axis injection breaks the rotational symmetry of the *** show theoretically and experimentally that cavity switching can be used to tailor the dynamic properties of the coupled QD-cavity *** report the generation of ultrashort spontaneous emission pulses(as short as 6 ps duration)by a collection of frequency-selected QDs in a switched pillar *** pulses display a very small coherence length,attractive for ultrafast speckle-free ***,the control of QD-mode coupling on the 10 ps time scale establishes cavity switching as an appealing resource for quantum photonics.

关键词： lifting injection cavity

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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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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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Marigold(Tagetes erecta): The Potential Value in the Phytoremediation of Chromium

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Pedosphere 2017年第3期27卷 559-568页

作者： Lívia C.COELHO Ana Rosa R.BASTOS Paulo J.PINHO guilherme A.souza Janice G.CARVALHO Viviane A.T.COELHO Luiz Carlos A.OLIVEIRA Rimena R.DOMINGUES Valdemar FAQUIN Soil Science Department Federal University of Lavras Chemistry Department Federal University of Minas Gerais

Environmental pollution with chromium （Cr） is harmful to humans, animals and plants, while in plants it causes diminished growth, anatomical alterations and death. In the present study, the potential value of marigold （Tagetes erecta） in the phytoremediation of Cr has been investigated. The randomized experimental design involved the exposure of plants to nutrient solutions containing 0.00, 0.04, 0.08, 0.12, 0.16 or 0.24 mmol L-1 Cr（III）. Chromium toxicity was observed at Cr（III） concentrations ≥ 0.12 mmol L-1 as demonstrated by diminished growth of the aerial parts and reduced density of the root system. Increasing Cr（III） concentrations in the nutrient solution resulted in a higher bioaccumulation of total Cr in the tissues, although translocation from roots to aerial parts was not efficient （maximum value of 25% at 0.12 mmol L-1 Cr（III））. The Cr bioaccumulation was up to 11-fold greater in roots than in the aerial parts. Tagetes erecta exhibited leaf plasticity when exposed to Cr, indicating the existence of a tolerance mechanism to Cr in this species. Chromium caused a reduction in xilem vases, resulting in a plastic effect in T. erecta leaves that increased the metal tolerance in culture solution. Tagetes spp. are potential Cr hyperaccumulators; at Cr（III） concentrations up to 0.12 mmol L-1, the plants accumulated levels above that proposed for hyperaccumulators and still maintained a considerable growth and even flourished. However, this study was conducted in nutrient solution, and studies on species confirmation as Cr hyperaccumulator should be conducted in soils for further clarification.

关键词： anatomical alterations heavy metal hyperaccumulor leaf anatomy toxicity

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