5,924 research outputs found

    Effect of conductivity, viscosity, and density of water-in-salt electrolytes on the electrochemical behavior of supercapacitors: Molecular dynamics simulations and: In situ characterization studies

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    We report here molecular dynamics simulations combined with in situ experimental studies to understand the advantages and disadvantages of replacing conventional (salt-in-water, SiWE) aqueous-based electrolytes with very concentrated (water-in-salt, WiSE) systems in supercapacitors. Atomistic molecular dynamics simulations were employed to investigate the energetic, structural, and transport properties of aqueous electrolytes based on sodium perchlorate (NaClO4). Simulations covered the concentrations range of 1 mol dm-3 (1 mol kg-1) to 8 mol dm-3 (15 mol kg-1), demonstrating a significant increase in viscosity and density and reduction in ionic conductivity as the concentration reaches the WiSE conditions. A carbon-based symmetric supercapacitor filled with WiSE showed a larger electrochemical stability window (ESW), allowing to span the cell voltage and specific energy. Larger ESW values are possible due to the formation of a solvent blocking interface (SBI). The formation of ionic aggregates owing to the increasing cohesive energy in WiSE disturbs the hydrogen-bond network resulting in physicochemical changes in the bulk liquid phase. In addition, the molal ratio between water and ions is decreased, resulting in a low interaction of the water molecules with the electrode at the interface, thus inhibiting the water-splitting considerably.Fil: Da Silva, Débora A. C.. Universidade Estadual de Campinas; BrasilFil: Pinzón, Manuel J.. Universidade Estadual de Campinas; BrasilFil: Messias Da Silva, Andresa. Universidad Federal do Abc; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Fileti, Eudes E.. Universidade de Sao Paulo; BrasilFil: Pascon, Aline. Universidade Estadual de Campinas; BrasilFil: Franco, Débora V.. University of Jequitinhonha e Mucuri's Valley; BrasilFil: Da Silva, Leonardo Morais. University of Jequitinhonha e Mucuri's Valley; BrasilFil: Zanin, Hudson G.. Universidade Estadual de Campinas; Brasi

    Hemispheric asymmetry in the sunspot cycle as a nonextensive phenomenon

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    The appearance of dark sunspots over the solar photosphere is not considered to be symmetric between the northern and southern hemispheres. Among the different conclusions obtained by several authors, we can point out that the North-South asymmetry is a real and systematic phenomenon and is not due to random variability. In the present work, we selected the sunspot area data of a sample of 13 solar cycles divided by hemisphere extracted from the Marshall Space Flight Centre (MSFC) database to investigate the behavior of probability distributions using an out-of-equilibrium statistical model a.k.a non-extensive statistical mechanics. Based on this statistical framework, we obtained that the non-extensive entropic parameter qq has a semi-sinusoidal variation with a period of \sim22 year (Hale cycle). Among the most important results, we can highlight that the asymmetry index q(A)q(A) revealed the dominance of the northern hemisphere against the southern one. Thus, we concluded that the parameter q(A)q(A) can be considered an effective measure for diagnosing long-term variations of the solar dynamo. Finally, our study opens a new approach to investigating solar variability from the nonextensive perspective.Comment: 17 pages, 2 tables and 5 figures. Submitted to Solar Physic

    Towards Automated Semantic Segmentation in Mammography Images

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    Mammography images are widely used to detect non-palpable breast lesions or nodules, preventing cancer and providing the opportunity to plan interventions when necessary. The identification of some structures of interest is essential to make a diagnosis and evaluate image adequacy. Thus, computer-aided detection systems can be helpful in assisting medical interpretation by automatically segmenting these landmark structures. In this paper, we propose a deep learning-based framework for the segmentation of the nipple, the pectoral muscle, the fibroglandular tissue, and the fatty tissue on standard-view mammography images. We introduce a large private segmentation dataset and extensive experiments considering different deep-learning model architectures. Our experiments demonstrate accurate segmentation performance on variate and challenging cases, showing that this framework can be integrated into clinical practice.Comment: 6 page

    Extracellular vesicle-mediated export of fungal RNA

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    Extracellular vesicles (EVs) play an important role in the biology of various organisms, including fungi, in which they are required for the trafficking of molecules across the cell wall. Fungal EVs contain a complex combination of macromolecules, including proteins, lipids and glycans. in this work, we aimed to describe and characterize RNA in EV preparations from the human pathogens Cryptococcus neoformans, Paracoccidiodes brasiliensis and Candida albicans, and from the model yeast Saccharomyces cerevisiae. the EV RNA content consisted mostly of molecules less than 250 nt long and the reads obtained aligned with intergenic and intronic regions or specific positions within the mRNA. We identified 114 ncRNAs, among them, six small nucleolar (snoRNA), two small nuclear (snRNA), two ribosomal (rRNA) and one transfer (tRNA) common to all the species considered, together with 20 sequences with features consistent with miRNAs. We also observed some copurified mRNAs, as suggested by reads covering entire transcripts, including those involved in vesicle-mediated transport and metabolic pathways. We characterized for the first time RNA molecules present in EVs produced by fungi. Our results suggest that RNA-containing vesicles may be determinant for various biological processes, including cell communication and pathogenesis.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Instituto Nacional de Ciencia e Tecnologia de Inovacao em Doencas Negligenciadas (INCT-IDN)Brazilian agency Fundacao Araucaria - PRONEXBrazilian agency Papes-FiocruzUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilFundacao Oswaldo Cruz, CDTS, Rio de Janeiro, RJ, BrazilUniv Fed Rio de Janeiro, Inst Microbiol Prof Paulo de Goes, BR-21941 Rio de Janeiro, RJ, BrazilFiocruz PR, Fundacao Oswaldo Cruz, Inst Carlos Chagas, Curitiba, PR, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilWeb of Scienc

    O Papel do ensino do português como língua estrangeira na defesa do multicultarismo

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    As política actuais existentes a nível oficial para a implementação e defesa do ensino da Língua Portuguesa como Língua Estrangeira (L. E.) na Europa e no resto do mundo levam-nos a pensar que são, sobretudo, os casos isolados de leitores portugueses pioneiros, inspirados e marginais que na sua missão individual e afastada lutam pela implementação e defesa desta língua nos seus países de acolhimento. Segundo Volfgram, “cabe ensinar a alguns que o multiculturalismo não está apenas na teoria e sim ao nosso redor, nos elevando realmente à condição de seres humanos” (2005), e o mesmo é dizer que o multiculturalismo começa nas suas bases pela aprendizagem desinteressada e não interesseira das crianças na sua mais tenra idade. Não é impunemente que em países multiculturais como a Bélgica, a Língua Portuguesa ensinada como segunda língua ou como língua estrangeira desempenha um papel preponderante na defesa e na preservação do Português e, em simultâneo, pugna pela defesa incontestável da necessidade incontornável que o multiculturalismo é hoje. É indubitável que a luta contra a xenofobia, a luta pela tolerância e o respeito mútuo, bem como o diálogo profícuo biunívoco não podem sobreviver actualmente sem uma consciencialização da importância das línguas minoritárias, da crioulização, da relação com as línguas maioritárias e da conquista da defesa do multiculturalismo hic et nunc. Abordando algumas opiniões avisadas, esperamos trazer à discussão temas importantes, tais como, a necessidade de articulação de políticas de difusão da língua portuguesa na Europa e no Mundo concertadamente com o Brasil e outros Países Lusófonos, a necessidade de implementação de medidas concretas no terreno para defesa da Língua de Camões fora de Portugal, a sobrevivência do Português que embora sendo minoritária na Europa é uma das línguas mais faladas no mundo, a necessidade da consciencialização para a crescente importância geo-estratégica do Português paralelamente com o recrudescimento do multiculturalismo à escala global

    A self-organizing map clustering approach to support territorial zoning

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    This work aims to evaluate three strategies for analyzing clusters of ordinal categorical data (thematic maps) to support the territorial zoning of the Alto Taquari basin, MS/MT. We evaluated a model-based method, another based on the segmentation of the multi-way contingency table, and the last one based on the transformation of ordinal data into intervals and subsequent analysis of clusters from a proposed method of segmentation of the Self-Organizing Map after the neural network training process. The results showed the adequacy of the methods based on the Self-Organizen Map and the segmentation of the contingency table, as these techniques generated unimodal clusters with distinguishable groups.Supported by National Council for Scientific and Technological Development –CNPq, Brazil, and by National Funds through the Portuguese funding agency, FCT -Fundação para a Ciência e a Tecnologia within project 2022.06822.PTDC. The work of Pedro Oliveira was also supported by the doctoral Grant PRT/BD/154311/2022 financed by the Portuguese Foundation for Science and Technology (FCT), and with funds from European Union, under MIT Portugal Progra

    Estudos sobre a paz e cultura da paz

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    Segundo o autor, a cultura da paz implica uma mudança quer na forma como a “alta cultura” lida com a realidade quer no tipo de abordagem que o senso comum faz às relações sociais, sendo que a ruptura com a ideologia conservadora, ou seja, com o senso comum realista só é possível graças a estas alterações. O autor realça tanto a importância que os estudos sobre a paz têm para o surgimento de um conceito amplo de paz, desenvolvido por Johan Galtung, como o facto destes estarem estrategicamente orientados para a transformação do sistema internacional. Sequentemente, conclui que a paz é uma categoria moral e cultural que só pode ser alcançada através do comportamento quotidian

    Evaluation of in vitro Antifungal Activity of Xylosma prockia (Turcz.) Turcz. (Salicaceae) Leaves Against Cryptococcus spp.

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    Cryptococcus species are responsible for important systemic mycosis and are estimated to cause millions of new cases annually. The available therapy is limited due to the high toxicity and the increasing rates of yeast resistance to antifungal drugs. Popularly known as “sucará,” Xylosma prockia (Turcz.) Turcz. (Salicaceae) is a native plant from Brazil with little information on its pharmacological potential. In this work, we evaluated in vitro anticryptococcal effects of the leaf ethanolic extract of X. prockia and its fractions against Cryptococcus gattii and Cryptococcus neoformans. We also evaluated phenotypic alterations caused by ethyl acetate fraction (EAF) (chosen according to its biological results). The liquid chromatography–mass spectrometry (LC-MS) analysis of EAF demonstrated the presence of phenolic metabolites that belong to three structurally related groups as majority compounds: caffeoylquinic acid, coumaroyl-glucoside, and caffeoyl-glucoside/deoxyhexosyl-caffeoyl glucoside derivatives. The minimum inhibitory concentration (MIC) values against C. gattii and C. neoformans ranged from 8 to 64 mg/L and from 0.5 to 8 mg/L, for ethanolic extract and EAF, respectively. The EAF triggered an oxidative burst and promoted lipid peroxidation. EAF also induced a reduction of ergosterol content in the pathogen cell membrane. These effects were not associated with alterations in the cell surface charge or in the thermodynamic fingerprint of the molecular interaction between EAF and the yeasts evaluated. Cytotoxic experiments with peripheral blood mononuclear cells (PBMCs) demonstrated that EAF was more selective for yeasts than was PBMCs. The results may provide evidence that X. prockia leaf extract might indeed be a potential source of antifungal agents.Fil: Folly, Mariany L. C.. Universidade Federal de Juiz de Fora; BrasilFil: Ferreira, Gabriella F.. Universidade Federal de Juiz de Fora; BrasilFil: Salvador, Maiara R.. Universidade Federal de Juiz de Fora; BrasilFil: Sathler, Ana A.. Universidade Federal de Juiz de Fora; BrasilFil: da Silva, Guilherme F.. Universidade Federal de Juiz de Fora; BrasilFil: Santos, Joice Castelo Branco. Ceuma University; BrasilFil: Santos, Julliana R. A. dos. Ceuma University; BrasilFil: Nunes Neto, Wallace Ribeiro. Ceuma University; BrasilFil: Rodrigues, João Francisco Silva. Ceuma University; BrasilFil: Fernandes, Elizabeth Soares. Ceuma University; BrasilFil: da Silva, Luís Cláudio Nascimento. Ceuma University; BrasilFil: de Freitas, Gustavo José Cota. Universidade Federal de Minas Gerais; BrasilFil: Denadai, Ângelo M.. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; BrasilFil: Rodrigues, Ivanildes V.. Universidade Federal de Juiz de Fora; BrasilFil: Mendonça, Leonardo M.. Universidade Federal de Juiz de Fora; BrasilFil: Monteiro, Andrea Souza. Ceuma University; BrasilFil: Santos, Daniel Assis. Universidade Federal de Minas Gerais; BrasilFil: Cabrera, Gabriela Myriam. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Siless, Gastón Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Lang, Karen L.. Universidade Federal de Juiz de Fora; Brasi
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