%0 Journal Article %J Polymer Composites %D Submitted %T New insight into natural fiber-reinforced polymer composites as pressure sensors: Experiment, theory, and application %A Costa, Cleidineia Cavalcante %A Ludmila Marotta Mapa %A Kelmer, Ana Carolina %A Ferreira, Sukarno Olavo %A Rodrigo Fernando Bianchi %K AC universality %K flexible device %K flexible electronics %K sustainable materials %X Abstract Research in hybrid and flexible natural fiber-reinforced polymer composites has included advances in innovative and environmentally sustainable devices. However, in practice, controversies still exist regarding the relationship between electrical and materials performance targets in a system design context. This work aimed to investigate the alternating conductivity of a novel pressure sensor based on semiconducting polyaniline (PANI)-coated vegetable fiber (VF, Euterpe oleracea Mart., Acai) in silicone polydimethylsiloxane (PDMS) rubber. We used alternating electrical conductivity measurements, σ*(ω) ∝ ωs (frequency range—ω from 1 Hz to 10 MHz; s 0.6), to adjust the optimal operating frequency region to enhance the pressure sensing performance of the PDMS-PANI-VF composites. A generalized effective-medium approach to the pressure-induced conductivity in terms of loading pressure, percolation regime, and the interpolation between Bruggeman's symmetric and asymmetric media theories was obtained. We have found a solution for inducing percolation in composites with a low concentration of fiber inclusions by uniaxial pressure (P), characterized by the expression σ ∝ (P−P0)t (0 ≤ t ≤ 4.0, 0 ≤ P0 ≤ 250 kPa). The sensor demonstrates maximum sensitivity of 1.5 Pa−1 in the operating electrical frequency from 1 to 100 Hz, and a wide linearity range from 0 to 250 kPa. The result provides new insight into the AC universality, s, and t behaviors of natural fiber-reinforced polymer composites to enhance pressure sensitivity of a new concept and technology for resource-efficiency optimization of sustainable environmental devices. %B Polymer Composites %V n/a %G eng %U https://onlinelibrary.wiley.com/doi/abs/10.1002/pc.27068 %N n/a %R https://doi.org/10.1002/pc.27068 %0 Journal Article %J The European Physical Journal Plus %D 2023 %T Black hole lensing in Kerr-de Sitter spacetimes %A Omwoyo, Eunice %A Belich, Humberto %A Fabris, Júlio C %A Velten, Hermano %B The European Physical Journal Plus %I Springer %V 138 %P 1043 %G eng %N 11 %0 Journal Article %J Applied Physics Letters %D 2023 %T B2N2O2: A wide-bandgap two-dimensional semiconductor featuring a zigzag nitrogen array of bonds %A Valentim, Mirela R. %A Matos, Matheus J. S. %A Mazzoni, Mario S. C. %X In this work, we apply a combination of theoretical techniques to characterize a two-dimensional material with formula B2N2O2, featuring a zigzag array of nitrogen atoms. We predict its energetic, thermal, and dynamic stability and determine its electronic properties, including band structure and mobility evaluation for a phonon-mediated mechanism. We show that the compound is a wideband-gap semiconductor, with parabolic band edges and with large electron and hole mobilities within the deformation potential approach. We ascribe this result to the existence of electronic channels defined by the zigzag array of nitrogen bonds, which define the edges of both conduction and valence bands. We also propose a mechanism to synthesize the compound based on oxygen functionalization and application of pressure. Finally, we show that the results can be generalized to represent a family of 2D compounds. %B Applied Physics Letters %V 123 %P 093103 %8 08 %G eng %U https://doi.org/10.1063/5.0160203 %N 9 %R 10.1063/5.0160203 %0 Journal Article %J Production %D 2023 %T Social Network Analysis in disaster management %A Flecha, Angela Cabral %A Bandeira, Renata Albergaria %A Campos, Vania Barcellos Gouvêa %A Silva, Alcides Volpato Castro %A Leiras, Adriana %B Production %I SciELO Brasil %V 33 %P e20220046 %G eng %0 Journal Article %J Symmetry %D 2023 %T Using Cosmological Perturbation Theory to Distinguish between GR and Unimodular Gravity %A Júlio C. Fabris %A Alvarenga, Marcelo H. %A Velten, Hermano %X Unimodular gravity is one of the oldest geometric gravity theories and alternatives to general relativity. Essentially, it is based on the Einstein–Hilbert Lagrangian with an additional constraint on the determinant of the metric. It can be explicitly shown that unimodular gravity can be recast as general relativity in the presence of a cosmological constant. This fact has led to many discussions on the equivalence of both theories at the classical and quantum levels. Here, we present an analysis focused on the classical scalar perturbations around a cosmological background. We focus on the unusual situation in which the typical conservation laws are not adopted. The discussion is extended to the case where a non-minimal coupled scalar field is introduced. We also present a gauge-invariant analysis showing that perturbations in unimodular gravity display instabilities. Our results reinforce that the equivalence is not verified completely at a cosmological perturbative level. %B Symmetry %V 15 %G eng %U https://www.mdpi.com/2073-8994/15/7/1392 %N 7 %R 10.3390/sym15071392 %0 Journal Article %J Nature Nanotechnology %D 2023 %T Pressure tuning of minibands in MoS2/WSe2 heterostructures revealed by moiré phonons %A Luiz G. Pimenta Martins %A Ruiz-Tijerina, David A. %A Occhialini, Connor A. %A Park, Ji-Hoon %A Song, Qian %A Ang-Yu Lu %A Pedro Venezuela %A Luiz G. Cançado %A Mazzoni, Mário S. C. %A Matos, Matheus J. S. %A Kong, Jing %A Riccardo Comin %X Moiré superlattices of two-dimensional heterostructures arose as a new platform to investigate emergent behaviour in quantum solids with unprecedented tunability. To glean insights into the physics of these systems, it is paramount to discover new probes of the moiré potential and moiré minibands, as well as their dependence on external tuning parameters. Hydrostatic pressure is a powerful control parameter, since it allows to continuously and reversibly enhance the moiré potential. Here we use high pressure to tune the minibands in a rotationally aligned MoS2/WSe2 moiré heterostructure, and show that their evolution can be probed via moiré phonons. The latter are Raman-inactive phonons from the individual layers that are activated by the moiré potential. Moiré phonons manifest themselves as satellite Raman peaks arising exclusively from the heterostructure region, increasing in intensity and frequency under applied pressure. Further theoretical analysis reveals that their scattering rate is directly connected to the moiré potential strength. By comparing the experimental and calculated pressure-induced enhancement, we obtain numerical estimates for the moiré potential amplitude and its pressure dependence. The present work establishes moiré phonons as a sensitive probe of the moiré potential as well as the electronic structures of moiré systems. %B Nature Nanotechnology %8 Jun %G eng %U https://doi.org/10.1038/s41565-023-01413-3 %R 10.1038/s41565-023-01413-3 %0 Journal Article %J PLOS ONE %D 2023 %T On the fractal patterns of language structures %A Leonardo Costa Ribeiro %A Américo Tristão Bernardes %A Mello, Heliana %X Natural Language Processing (NLP) makes use of Artificial Intelligence algorithms to extract meaningful information from unstructured texts, i.e., content that lacks metadata and cannot easily be indexed or mapped onto standard database fields. It has several applications, from sentiment analysis and text summary to automatic language translation. In this work, we use NLP to figure out similar structural linguistic patterns among several different languages. We apply the word2vec algorithm that creates a vector representation for the words in a multidimensional space that maintains the meaning relationship between the words. From a large corpus we built this vectorial representation in a 100-dimensional space for English, Portuguese, German, Spanish, Russian, French, Chinese, Japanese, Korean, Italian, Arabic, Hebrew, Basque, Dutch, Swedish, Finnish, and Estonian. Then, we calculated the fractal dimensions of the structure that represents each language. The structures are multi-fractals with two different dimensions that we use, in addition to the token-dictionary size rate of the languages, to represent the languages in a three-dimensional space. Finally, analyzing the distance among languages in this space, we conclude that the closeness there is tendentially related to the distance in the Phylogenetic tree that depicts the lines of evolutionary descent of the languages from a common ancestor. %B PLOS ONE %I Public Library of Science %V 18 %P 1-20 %8 05 %G eng %U https://doi.org/10.1371/journal.pone.0285630 %N 5 %R 10.1371/journal.pone.0285630 %0 Journal Article %J Liquid Crystals %D 2023 %T Unlocking the potential of 2,1,3-benzoxadiazole-based luminescent liquid crystals %A Fabrícia Nunes da Silva %A Eliane Oliveira Silva %A Gerson dos Santos %A Bruna B. Postacchini %A Cazati, Thiago %A Bechtold, Ivan H. %A André Alexandre Vieira %B Liquid Crystals %I Taylor & Francis %P 1-11 %G eng %U https://doi.org/10.1080/02678292.2023.2202160 %R 10.1080/02678292.2023.2202160 %0 Journal Article %J Ensaio Pesquisa em Educação em Ciências (Belo Horizonte) %D 2023 %T PRESENTATION OF CONCEPTS IN A CHILDREN’S SCIENCE COMMUNICATION BOOK: THE CASE OF “ISAAC NO MUNDO DAS PARTÍCULAS” %A Araujo, João Felipe Viana de %A Lima, Guilherme da Silva %A Almeida, Sheila Alves de %B Ensaio Pesquisa em Educação em Ciências (Belo Horizonte) %I SciELO Brasil %V 25 %P e39775 %G eng %0 Journal Article %J Ceramics International %D 2023 %T Nanostructured system based on hydroxyapatite and curcumin: A promising candidate for osteosarcoma therapy %A Jéssica Pauline Nunes Marinho %A Natalia Paz Neme %A Matheus Josue de Souza Matos %A Ronaldo Junio Campos Batista %A Waldemar Augusto de Almeida Macedo %A Pedro Lana Gastelois %A Dawidson Assis Gomes %A Michele Angela Rodrigues %A Marcelo Fernandes Cipreste %A Edésia Martins Barros Sousa %K Curcumin %K Hydroxyapatite %K Nanostructures %K Osteosarcoma %X Osteosarcoma is the most common type of bone cancer. Despite therapeutic progress, survival rates for metastatic cases or that do not respond well to chemotherapy remain in the 30% range. In this sense, the use of nanotechnology to develop targeted and more effective therapies is a promising tool in the fight against cancer. Nanostructured hydroxyapatite, due to its biocompatibility and the wide possibility of functionalization, is an interesting material to design nanoplatforms for targeted drug delivery. These platforms have the potential to enable the use of natural substances in the fight against cancer, such as curcumin. Curcumin is a polyphenol with promising properties in treating various types of cancer, including osteosarcoma. In this work, hydroxyapatite (n-HA) nanorods synthesized by the hydrothermal method were investigated as a carrier for curcumin. For this, first-principle calculations based on the Density Functional Theory (DFT) were performed, in which the modification of curcumin (CM) with the coupling agent (3-aminopropyl) triethoxysilane (APTES) was theoretically evaluated. Curcumin was incorporated in n-HA and the drug loading stability was evaluated by leaching test. Samples were characterized by a multi-techniques approach, including Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–Vis), X-ray diffraction (XRD), X-ray fluorescence spectrometry (FRX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), zeta potential analysis (ζ), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results show that n-HAs with a 90 nm average size were obtained and successful incorporation of curcumin in the nanostructure was achieved. Cell viability and the number of osteosarcoma cells were decreased by CMAP-HA treatment. Furthermore, the stability test suggests that hydroxyapatite nanoparticles present great potential for the transportation of curcumin in the bloodstream, crediting this system for biological performance evaluations aiming at the treatment of osteosarcomas. Keywords: nanostructures, curcumin, hydroxyapatite, osteosarcoma. %B Ceramics International %G eng %U https://www.sciencedirect.com/science/article/pii/S0272884223006995 %R https://doi.org/10.1016/j.ceramint.2023.03.115 %0 Journal Article %J Applied Physics Reviews %D 2023 %T High-pressure studies of atomically thin van der Waals materials %A Luiz G. Pimenta Martins %A Riccardo Comin %A Matos, Matheus J. S. %A Mazzoni, Mário S. C. %A Neves, Bernardo R. A. %A Yankowitz,Matthew %B Applied Physics Reviews %V 10 %P 011313 %G eng %U https://doi.org/10.1063/5.0123283 %N 1 %R 10.1063/5.0123283 %0 Book %D 2023 %T TRANSFORMAÇÕES DE FASES EM MATERIAIS %A André Barros Cota %C Ouro Preto %P 626 %G eng %U https://drive.google.com/file/d/1-p-XyYYyAlzvNujj2Xw_Yhpdo8rv80kU/view?usp=drive_web %0 Journal Article %J Beilstein Journal of Nanotechnology %D 2023 %T Liquid phase exfoliation of talc: effect of the medium on flake size and shape %A Sousa, Samuel M %A Morais, Helane LO %A Joyce C C Santos %A Ana Paula M Barboza %A Bernardo R A Neves %A Pinto, Elisângela S %A Prado, Mariana C %B Beilstein Journal of Nanotechnology %I Beilstein-Institut %V 14 %P 68–78 %G eng %N 1 %0 Journal Article %J REM-International Engineering Journal %D 2023 %T Growth and structural characterization of Tutton salt mixed of Co and Ni %A Leocádio, Rodolfo Rocha Vieira %A Perpétuo, Genivaldo Júlio %A Franco, Carlos Joel %A Batista, Adriano Corrêa %B REM-International Engineering Journal %I SciELO Brasil %V 76 %P 55–62 %G eng %0 Journal Article %J Beilstein Archives %D 2022 %T Carbon nanotube-cellulose ink for rapid liquid identification %A Tiago Amarante %A Cunha, Thiago H. R. %A Claudio Laudares %A Barboza, Ana P. M. %A Ana Carolina dos Santos %A Cintia L. Pereira %A Vinicius Ornelas %A Neves, Bernardo R. A. %A Ferlauto, Andre S. %A Lacerda, Rodrigo G. %B Beilstein Archives %G eng %R 10.3762/bxiv.2022.90.v1 %0 Journal Article %J The Journal of Physical Chemistry C %D 2022 %T Charge and Spin Current Rectification through Functionalized Boron Nitride Bilayers %A Moraes, Elizane E. de %A Alysson A. Pinto %A Batista, Ronaldo J. C. %A de Oliveira, Alan B. %A Chacham, Helio %B The Journal of Physical Chemistry C %P null %G eng %U https://doi.org/10.1021/acs.jpcc.2c03608 %R 10.1021/acs.jpcc.2c03608 %0 Journal Article %J Classical and Quantum Gravity %D 2022 %T Constraining GUP models using limits on SME coefficients %A Herkenhoff Gomes, André %X Generalized uncertainty principles (GUP) and, independently, Lorentz symmetry violations are two common features in many candidate theories of quantum gravity. Despite that, the overlap between both has received limited attention so far. In this brief paper, we carry out further investigations on this topic. At the nonrelativistic level and in the realm of commutative spacetime coordinates, a large class of both isotropic and anisotropic GUP models is shown to produce signals experimentally indistinguishable from those predicted by the Standard Model Extension (SME), the common framework for studying Lorentz-violating phenomena beyond the Standard Model. This identification is used to constrain GUP models using current limits on SME coefficients. In particular, bounds on isotropic GUP models are improved by a factor of $10^7$ compared to current spectroscopic bounds and anisotropic models are constrained for the first time. %B Classical and Quantum Gravity %G eng %U http://iopscience.iop.org/article/10.1088/1361-6382/ac9ae5 %0 Journal Article %J Liquid Crystals %D 2022 %T Rod-shaped cyanoacrylic derivatives with D-π-A architecture: synthesis, thermal, photophysical and theoretical studies %A Caroline S. B. Weber %A Aline Tavares %A Bruno Bercini de Araújo %A Rebeca O. Costa %A Manhabosco, Taise M. %A Bruna B. Postacchini %A Vieira, André A. %A Cazati, Thiago %A Aloir A. Merlo %B Liquid Crystals %I Taylor & Francis %P 1-11 %G eng %U https://doi.org/10.1080/02678292.2022.2122088 %R 10.1080/02678292.2022.2122088 %0 Journal Article %J Computational Materials Science %D 2022 %T BCN diamondol-like compounds: Stability trends and electronic properties %A A.K.M. Pinto %A J.M. Pontes %A Matos, Matheus J. S. %A Mazzoni, Mario S. C. %A Azevedo, S. %K 2D materials %K BCN compounds %K Diamane %K Diamondol %K Nanostructures %X In this work we apply first principles calculations to investigate the stability trends of mixed boron, nitrogen and carbon diamondol-like compounds. Several distinct geometric models are tested by varying the stoichiometry and position of boron and nitrogen dopants. We verify the special stability of a complete boron nitride compound – the bonitrol –, and we show that carbon substitutions in the bonitrol structure may also lead to stable systems. The electronic characterization of the resulting compounds indicates a rich phenomenology, with metallic, semimetallic, half-metallic and semiconducting behaviors. %B Computational Materials Science %V 215 %P 111737 %G eng %U https://www.sciencedirect.com/science/article/pii/S0927025622004566 %R https://doi.org/10.1016/j.commatsci.2022.111737 %0 Journal Article %J Formação Docente – Revista Brasileira de Pesquisa sobre Formação de Professores %D 2022 %T A FORMAÇÃO CONTINUADA DE PROFESSORES EM TEMPOS DA PANDEMIA DO COVID-19: CONTRIBUIÇÕES DA NEUROCIÊNCIA APLICADA À EDUCAÇÃO %A GOMES, Larissa Layane %A Guimarães, Michele Hidemi Ueno %A CRUZ, Luciana Hoffert Castro %B Formação Docente – Revista Brasileira de Pesquisa sobre Formação de Professores %V 14 %P 197–210 %8 ago. %G eng %U https://revformacaodocente.com.br/index.php/rbpfp/article/view/564 %N 30 %R 10.31639/rbpfp.v14i30.564 %0 Journal Article %J Phys. Rev. B %D 2022 %T Investigation of spatially localized defects in synthetic $\mathrmWS_2$ monolayers %A Rosa, Bárbara L. T. %A Kazunori Fujisawa %A Joyce C. C. Santos %A Tianyi Zhang %A Matos, Matheus J. S. %A Sousa, Frederico B. %A Tiago C. Barbosa %A Lucas Lafeta %A Ramos, Sérgio L. L. M. %A Bruno R. Carvalho %A Chacham, Helio %A Neves, Bernardo R. A. %A Mauricio Terrones %A Malard, Leandro M. %B Phys. Rev. B %I American Physical Society %V 106 %P 115301 %8 Sep %G eng %U https://link.aps.org/doi/10.1103/PhysRevB.106.115301 %R 10.1103/PhysRevB.106.115301 %0 Journal Article %J Cadernos de Astronomia %D 2022 %T Um critério energético para o desenvolvimento de vida em um exoplaneta %A Velten, Hermano %A Delladea, Douglas %A Primola, Arthur %B Cadernos de Astronomia %V 3 %P 59–65 %8 ago. %G eng %U https://periodicos.ufes.br/astronomia/article/view/38561 %N 2 %R 10.47456/Cad.Astro.v3n2.38561 %0 Journal Article %J Universe %D 2022 %T Brans–Dicke Unimodular Gravity %A Almeida, Alexandre M. R. %A Júlio C. Fabris %A Daouda, Mahamadou Hamani %A Kerner, Richard %A Velten, Hermano %A Hipólito-Ricaldi, Willian S. %X We propose a unimodular version of the Brans–Dicke theory designed with a constrained Lagrangian formulation. The resulting field equations are traceless. The vacuum solutions in the cosmological background reproduce the corresponding solutions of the usual Brans–Dicke theory but with a cosmological constant term. A perturbative analysis of the scalar modes is performed and stable and unstable configurations appear, in contrast with the Brans–Dicke case for which only stable configurations occur. On the other hand, tensorial modes in this theory remain the same as in the traditional Brans–Dicke theory. %B Universe %V 8 %G eng %U https://www.mdpi.com/2218-1997/8/8/429 %N 8 %R 10.3390/universe8080429 %0 Journal Article %J Food Analytical Methods %D 2022 %T Immobilization of Anthocyanin in Polymeric Film to Obtain a Colorimetric Sensor for Detection of Copper in Cachaça %A Figueiredo, Matheus Torres Duarte %A Ferreira, Gabriel Max Dias %A Lopez, Melany Alejandra Ruiz %A das Graças Cardoso, Maria %A de Oliveira, Juliano Elvis %A Rodrigo Fernando Bianchi %A Ferreira, Guilherme Max Dias %A Mageste, Aparecida Barbosa %B Food Analytical Methods %I Springer %P 1–19 %G eng %0 Journal Article %J Revista Brasileira Interdisciplinar de Saúde %D 2022 %T CONHECIMENTO DOS ADOLESCENTES COM RELA\cCÃO ÀS INFEC\cCÕES SEXUALMENTE TRANSMISSÍVEIS %A da Silva Lima, Guilherme %A de Souza, Luccas Vin{\'ıcio %A Farias, Maryana Rodrigues %A Caldeira, Angelita Giovana %A de Andrade Aoyama, Elisângela %B Revista Brasileira Interdisciplinar de Saúde %G eng %0 Journal Article %J Materials Research %D 2022 %T Characterization of Magnetic Tailings from Phosphate-Ore Processing in Alto Parana{\'ıba %A Silva, Fernando Brandão Rodrigues da %A Araújo, Fernando Gabriel Silva %A von Krüger, Fernando Leopoldo %A Guilherme Jorge Brigolini Silva %A Ronaldo Junio Campos Batista %A Manhabosco, Ta{\'ıse Matte %B Materials Research %I SciELO Brasil %V 25 %G eng %0 Journal Article %J ACS Applied Electronic Materials %D 2022 %T Delayed Fluorescence by Triplet–Triplet Annihilation from Columnar Liquid Crystal Films %A Franca, Larissa G. %A dos Santos, Paloma L. %A Pander, Piotr %A Cabral, Marília G. B. %A Cristiano, Rodrigo %A Cazati, Thiago %A Monkman, Andrew P. %A Bock, Harald %A Eccher, Juliana %B ACS Applied Electronic Materials %P null %G eng %U https://doi.org/10.1021/acsaelm.2c00432 %R 10.1021/acsaelm.2c00432 %0 Journal Article %J The European Physical Journal C %D 2022 %T Nonconservative unimodular gravity: a viable cosmological scenario? %A Júlio C. Fabris %A Alvarenga, Marcelo H. %A Hamani-Daouda, Mahamadou %A Velten, Hermano %X In this work we review the issue of imposing the conservation of the energy–momentum tensor as a necessary condition to recover the equivalence between the unimodular gravity and General Relativity (GR) equipped with a cosmological constant. This procedure is usually interpreted as an ad hoc imposition on the unimodular theory's structure. Whereas the consequences of avoiding the conservation of the total energy–momentum tensor has been already introduced in the literature, it has been not widely explored so far. We study an expanding universe sourced by a single effective perfect fluid such that the null divergence of its energy–momentum tensor is not imposed. As we shall show, in this scheme, the unimodular theory has its own conservation equation obtained from the Bianchi identities. We explore the evolution of the homogeneous and isotropic expanding background and show that a viable cosmological scenario exists. Also, we consider scalar perturbations with particular attention given to the gauge issue. We show that contrary to the traditional unimodular theory where the synchronous and longitudinal (newtonian) gauge for cosmological perturbations are not permitted, if the conservation of the energy–momentum is relaxed the scalar perturbations in the synchronous condition survive and present a growing mode behavior. We study therefore a new cosmological scenario in which the dynamics of the universe transits from the radiative phase directly to a accelerated one but allowing thus for structure formation. %B The European Physical Journal C %V 82 %P 522 %8 Jun %G eng %U https://doi.org/10.1140/epjc/s10052-022-10470-2 %N 6 %R 10.1140/epjc/s10052-022-10470-2 %0 Journal Article %J Surface and Coatings Technology %D 2022 %T Improved bioceramic coatings reinforced by nanostructured talc %A Ana Barbara Batista %A Michael Stanley %A de Brito, Ana Carolina Ferreira %A Rebecca Vasconcellos %A Munk, Michele %A Mário José-Bueno %A Cristina Godoy %A Érika Costa de Alvarenga %A Cláudia Karina Barbosa de Vasconcelos %A Ariete Righi %A Edésia M.B. de Sousa %A de Oliveira, Alan Barros %A Ronaldo Junio Campos Batista %A Jaqueline dos Santos Soares %A Almeida Neves, Bernardo Ruegger %A Ana Paula Moreira Barbosa %A Taíse Matte Manhabosco %K Biocompatibility %K Hydroxyapatite %K Mechanical properties %K Pulsed electrodeposition %K Soapstone nano-talc %X Nano-talc was successfully incorporated in the hydroxyapatite matrix via pulsed electrodeposition after being obtained using an eco-friendly liquid-phase exfoliation process. Scanning electron microscopy, atomic force microscopy, X-ray spectroscopy, Raman spectroscopy, corrosion and wear resistance, and cytocompatibility tests were used to characterize the biocomposite ceramics. Talc significantly improves the nanomechanical and wear properties of bioceramics (i.e., higher stiffness, reduced friction coefficient, and lower wear damage) as well as corrosion resistance. Talc does not induce cytotoxic activity in in vitro cells and may induce bone maturation as per biocompatibility tests. %B Surface and Coatings Technology %V 441 %P 128589 %G eng %U https://www.sciencedirect.com/science/article/pii/S0257897222005102 %R https://doi.org/10.1016/j.surfcoat.2022.128589 %0 Journal Article %J Phys. Rev. D %D 2022 %T Skewness as a test of dark energy perturbations %A Fazolo, Raquel Emy %A Amendola, Luca %A Velten, Hermano %B Phys. Rev. D %I American Physical Society %V 105 %P 103521 %8 May %G eng %U https://link.aps.org/doi/10.1103/PhysRevD.105.103521 %R 10.1103/PhysRevD.105.103521 %0 Journal Article %J ACS Nano %D 2022 %T Electronic Band Tuning and Multivalley Raman Scattering in Monolayer Transition Metal Dichalcogenides at High Pressures %A Luiz G. Pimenta Martins %A Bruno R. Carvalho %A Occhialini, Connor A. %A Neme, Natália P. %A Park, Ji-Hoon %A Song, Qian %A Pedro Venezuela %A Mazzoni, Mário S. C. %A Matos, Matheus J. S. %A Kong, Jing %A Riccardo Comin %B ACS Nano %P null %G eng %U https://doi.org/10.1021/acsnano.2c01065 %R 10.1021/acsnano.2c01065 %0 Journal Article %J arXiv preprint arXiv:2205.02044 %D 2022 %T Deformations of the canonical commutation relation and Lorentz symmetry violation %A Gomes, André H %B arXiv preprint arXiv:2205.02044 %G eng %0 Journal Article %J The European Physical Journal C %D 2022 %T Remarks on the black hole shadows in Kerr-de Sitter space times %A Omwoyo, Eunice %A Belich, Humberto %A Fabris, Júlio C %A Velten, Hermano %B The European Physical Journal C %I Springer %V 82 %P 1–17 %G eng %N 5 %0 Journal Article %J Experiências em Ensino de Ciências %D 2022 %T UMA ANÁLISE CRÍTICA SOBRE A IMPLEMENTA\cCÃO DO SCALE-UP NO INSTITUTO DE FÍSICA DA UNIVERSIDADE DE SÃO PAULO %A Guimarães, Michele Hidemi Ueno %A Muramatsu, Mikiya %A Passos, Marinez Meneghello %B Experiências em Ensino de Ciências %V 17 %P 57–75 %G eng %N 1 %0 Journal Article %J Research, Society and Development %D 2022 %T Astronomical phenomena: a teaching proposal %A Lima, Filipe Paixão de %A Guimarães, Michele Hidemi Ueno %A Passos, Marinez Meneghello %B Research, Society and Development %V 11 %P e15211629011 %8 Apr. %G eng %U https://rsdjournal.org/index.php/rsd/article/view/29011 %N 6 %R 10.33448/rsd-v11i6.29011 %0 Journal Article %J Journal of Materials Science %D 2022 %T Graphene nanoencapsulation action at an air/lipid interface %A Ferrari, Gustavo A %A Chacham, Helio %A Alan B de Oliveira %A Matheus J S Matos %A Ronaldo J C Batista %A Meireles, Leonel M %A Ana Paula M Barboza %A Silvestre, Ive %A Bernardo R A Neves %A Rodrigo G Lacerda %B Journal of Materials Science %I Springer %P 1–10 %G eng %0 Journal Article %J ACS Omega %D 2022 %T Aerosol-Printed MoS2 Ink as a High Sensitivity Humidity Sensor %A Pereira, Neuma M. %A Rezende, Natália P. %A Cunha, Thiago H. R. %A Barboza, Ana P. M. %A Silva, Glaura G. %A Lippross, Daniel %A Neves, Bernardo R. A. %A Chacham, Hélio %A Ferlauto, Andre S. %A Lacerda, Rodrigo G. %B ACS Omega %P null %G eng %U https://doi.org/10.1021/acsomega.1c06525 %R 10.1021/acsomega.1c06525 %0 Journal Article %J Vaccines %D 2022 %T Successive Pandemic Waves with Different Virulent Strains and the Effects of Vaccination for SARS-CoV-2 %A Castro e Silva, Alcides %A Américo Tristão Bernardes %A Barbosa, Eduardo Augusto Gonçalves %A Chagas, Igor Aparecido Santana das %A Dáttilo, Wesley %A Reis, Alexandre Barbosa %A Ribeiro, Sérvio Pontes %X One hundred years after the flu pandemic of 1918, the world faces an outbreak of a new severe acute respiratory syndrome, caused by a novel coronavirus. With a high transmissibility, the pandemic has spread worldwide, creating a scenario of devastation in many countries. By the middle of 2021, about 3% of the world population had been infected and more than 4 million people had died. Different from the H1N1 pandemic, which had a deadly wave and ceased, the new disease is maintained by successive waves, mainly produced by new virus variants and the small number of vaccinated people. In the present work, we create a version of the SIR model using the spatial localization of persons, their movements, and considering social isolation probabilities. We discuss the effects of virus variants, and the role of vaccination rate in the pandemic dynamics. We show that, unless a global vaccination is implemented, we will have continuous waves of infections. %B Vaccines %V 10 %G eng %U https://www.mdpi.com/2076-393X/10/3/343 %N 3 %R 10.3390/vaccines10030343 %0 Journal Article %J Solid State Communications %D 2022 %T Optical properties of boron nitride nanoribbons with reconstruted edges %A Gonçalves, Juliana A. %A Osmar F.P. dos Santos %A Batista, Ronaldo J. C. %A Sérgio Azevedo %K Boron nitride nanosheets %K Optical properties %K Reconstructions edges %X In this work, we employ first-principles calculations to investigate the optical properties of boron nitride nanoribbons with reconstructed edges. We found that because of the presence of homopolar B-B and N-N bonds in the edges, such nanoribbons, unlike boron nitride nanotubes, absorb light and have non-null optical conductivity in the visible and infrared range. The stoichiometry and distribution of the homopolar bonds in the edges change the absorption, reflectance, refraction index, and optical conductivity of nanoribbons, which may allow the tuning of those properties. Regarding the absorption in the infrared and visible range, the nanoribbons with B excess are almost unaffected by the direction of light incidence. On the other hand, the direction of light incidence strongly affects the intensity of the absorption peaks of nanoribbons with N excess in the region. At ultraviolet and above non-cylindrical geometry of the ribbons with the homopolar bonds at the edges also lead to a dependence of the optical properties with the direction of light incidence. %B Solid State Communications %P 114627 %G eng %U https://www.sciencedirect.com/science/article/pii/S0038109821004051 %R https://doi.org/10.1016/j.ssc.2021.114627 %0 Journal Article %J Chemical Physics Letters %D 2022 %T First-principle investigation of silicon carbide nanosheets fluorination: Stability trends, electronic, optical and magnetic properties %A Gonçalves, Juliana A. %A Osmar F.P. dos Santos %A Batista, Ronaldo J. C. %A Sérgio Azevedo %K DFT %K Nanomaterials %K Nanosheets %K Silicon Carbide(SiC) %X We employed first-principles calculations to investigate the fluorination of silicon carbide nanosheets. We found that the Si atoms are the energetically favorable adsorption sites for F atoms in silicon carbide nanosheets in all studied cases. The strain caused by the fourfold coordinated Si atoms in the flat SiC nanosheet determines the relative position of the adsorbed F atoms: occupying nearest-neighbor Si sites if they bound sheet’s opposing sides or away from each other if they are on the same side of the sheet. The fluorinated nanosheets’ electronic and magnetic properties are weakly dependent on which side of the sheet the F atoms bind; however, they are strongly dependent on the relative distance between them. For F atoms adsorbed on nearest-neighbor Si sites, the system is a small gap p-type semiconductor with 1 μB per adsorbed atom. On the other hand, if F atoms do not occupy nearest-neighbor Si sites, the system is a metal with 1/2 μB per adsorbed atom. The adsorption of F atoms strongly affects the optical properties of SiC sheets inducing optical anisotropy regarding the direction of the incidence of light. %B Chemical Physics Letters %V 787 %P 139266 %G eng %U https://www.sciencedirect.com/science/article/pii/S0009261421009490 %R https://doi.org/10.1016/j.cplett.2021.139266 %0 Journal Article %J Revista Brasileira de Pesquisa em Educação em Ciências %D 2021 %T Interações Discursivas entre Educadores Museais e Estudantes: Um Estudo de Caso em um Museu de Ciências a partir das Contribuições de Bakhtin e do C{\'ırculo %A Lima, Guilherme %A Rocha, Jessica Norberto %B Revista Brasileira de Pesquisa em Educação em Ciências %P e21788–33 %G eng %0 Journal Article %J Revista Brasileira de Pesquisa em Educação em Ciências %D 2021 %T As Representações de Stephen Hawking em Filmes Biográficos %A Fernandes, João %A Lima, Guilherme %A Aguiar Jr, Orlando Gomes %B Revista Brasileira de Pesquisa em Educação em Ciências %P e16539–32 %G eng %0 Journal Article %J Investigações em Ensino de Ciências %D 2021 %T CIÊNCIA, ARTE E FILOSOFIA: MOBILIZANDO DISCURSOS NO USO EDUCATIVO DO CINEMA NUMA ATIVIDADE NÃO FORMAL %A da Silva Lima, Guilherme %A Pagliarini, Cassiano Rezende %A Aguiar Jr, Orlando Gomes %B Investigações em Ensino de Ciências %I Universidade Federal do Rio Grande do Sul, Instituto de F{\'ısica %V 26 %P 305–323 %G eng %N 1 %0 Journal Article %J Chasqui: Revista Latinoamericana de Comunicación %D 2021 %T Mensagens falsas sobre o novo coronav{\'ırus: legitimidade e manipulação na luta de classes %A da Silva Lima, Guilherme %A Calazans, Marcos Moraes %A Massi, Luciana %B Chasqui: Revista Latinoamericana de Comunicación %I Centro Internacional de Estudios Superiores de Comunicación para América … %P 259–279 %G eng %N 147 %0 Journal Article %J História, Ciências, Saúde-Manguinhos %D 2021 %T Da reformulação discursiva a uma práxis da cultura cient{\'ıfica: reflexões sobre a divulgação cient{\'ıfica %A Lima, Guilherme da Silva %A Giordan, Marcelo %B História, Ciências, Saúde-Manguinhos %I SciELO Brasil %V 28 %P 375–392 %G eng %0 Journal Article %J Physics %D 2021 %T Stellar Structure in a Newtonian Theory with Variable G %A Júlio C. Fabris %A Ottoni, Túlio %A Júnior D. Toniato %A Velten, Hermano %X A Newtonian-like theory inspired by the Brans–Dicke gravitational Lagrangian has been recently proposed by us. For static configurations, the gravitational coupling acquires an intrinsic spatial dependence within the matter distribution. Therefore, the interior of astrophysical configurations may provide a testable environment for this approach as long as no screening mechanism is evoked. In this work, we focus on the stellar hydrostatic equilibrium structure in such a varying Newtonian gravitational coupling G scenario. A modified Lane–Emden equation is presented and its solutions for various values of the polytropic index are discussed. The role played by the theory parameter ω, the analogue of the Brans–Dicke parameter, in the physical properties of stars is discussed. %B Physics %V 3 %P 1123–1132 %G eng %U https://www.mdpi.com/2624-8174/3/4/71 %N 4 %R 10.3390/physics3040071 %0 Journal Article %J ACS Applied Nano Materials %D 2021 %T Electromechanical Modulations in Transition Metal Dichalcogenide Nanosheets: Implications for Environmental Sensors %A Bessa, Mauricio V. %A Freitas, Wellington D. %A Neme, Natália P. %A Martins, Luiz G. P. %A Barboza, Ana P. M. %A Matos, Matheus J. S. %A Mazzoni, Mario S. C. %A Neves, Bernardo R. A. %B ACS Applied Nano Materials %P null %G eng %U https://doi.org/10.1021/acsanm.1c03002 %R 10.1021/acsanm.1c03002 %0 Journal Article %J Caderno Brasileiro de Ensino de F{\'ısica %D 2021 %T Sequência Didática para o ensino de Astronomia %A Silva, Victor Peres %A Guimarães, Michele Hidemi Ueno %A Passos, Marinez Meneghello %B Caderno Brasileiro de Ensino de F{\'ısica %V 38 %P 1135–1165 %G eng %N 2 %0 Journal Article %J medRxiv %D 2021 %T Successive pandemic waves with more virulent strains, and the effects of vaccination for SARS-CoV-2 %A Castro-e-Silva, Alcides %A Bernardes, Américo T %A Gon\c calves Barbosa, Eduardo Augusto %A Dáttilo, Wesley %A SÉRVIO P. RIBEIRO %X Hundred years after the flu pandemic of 1918, the world faces an outbreak of a new severe acute respiratory syndrome, caused by a novel coronavirus. With a high transmissibility, the pandemic spreads worldwide, creating a scenario of devastation in many countries. By the middle of 2021, about 3% of the world population has been infected and more than 4 million people have died. Different from the H1N1 pandemic, which had a deadly wave and cessed, the new disease is maintained by successive waves, mainly produced by new virus variants, and the small number of vaccinated people. In the present work, we create a version of the SIR model with spatial localization of persons, their movements, and taking into account social isolation probabilities. We discuss the effects of virus variants, and the role of vaccination rate in the pandemic dynamics. We show that, unless a global vaccination is implemented, we will have continuous waves of infections.HighlightsThe COVID-19 has infected more than 200 millions and has killed more than 4 million persons.WHO has not been successful in defining a global vaccination policy.Many epidemic scenarios arise when different countries apply different vaccination strategies.Present model can show some insights on how vaccination programs can be managed.Competing Interest StatementThe authors have declared no competing interest.Funding StatementThis research did not receive any specific grant from funding agencies in the commercial, or non-profit sectors. SPR acknowledges grant from Conselho Nacional de Desenvolvimento Cientifico e Tecnologico - CNPq, through proccess 306572/2019-2.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The manuscript is a modeling paper, there was no clinical trial of any kind.All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesThe code of model is included in manuscript files. %B medRxiv %I Cold Spring Harbor Laboratory Press %G eng %U https://www.medrxiv.org/content/early/2021/09/24/2021.09.21.21263901 %R 10.1101/2021.09.21.21263901 %0 Journal Article %J Phys. Rev. D %D 2021 %T Early-time thermalization of cosmic components? A hint for solving cosmic tensions %A Velten, Hermano %A Costa, Ingrid %A Zimdahl, Winfried %B Phys. Rev. D %I American Physical Society %V 104 %P 063507 %8 Sep %G eng %U https://link.aps.org/doi/10.1103/PhysRevD.104.063507 %R 10.1103/PhysRevD.104.063507 %0 Journal Article %J RSC Adv. %D 2021 %T Interplay between structural deformations and flat band phenomenology in twisted bilayer antimonene %A Alan C.R. Souza %A Matos, Matheus J. S. %A Mazzoni, Mario S. C. %X In this work we apply first principles calculations to investigate the flat band phenomenology in twisted antimonene bilayer. We show that the relatively strong interlayer interactions which characterize this compound have profound effects in the emergence and properties of the flat bands. Specifically, when the moiré length becomes large enough to create well defined stacking patterns along the structure, out-of-plane displacements take place and are stabilized in the regions dominated by the AB stacking, leading to the emergence of flat bands. The interplay between structural and electronic properties allows for detection of flat bands in higher twist angles comparable to other two-dimensional materials. We also show that their energy position may be modulated by noncovalent functionalization with electron acceptor molecules. %B RSC Adv. %I The Royal Society of Chemistry %V 11 %P 27855-27859 %G eng %U http://dx.doi.org/10.1039/D1RA05301A %R 10.1039/D1RA05301A %0 Journal Article %D 2021 %T From Spanish Flu to Syndemic COVID-19: long-standing sanitarian vulnerability of Manaus, warnings from the Brazilian rainforest gateway %A SÉRVIO P. RIBEIRO %A ALEXANDRE B. REIS %A Dáttilo, Wesley %A ALCIDES V.C. DE CASTRO E SILVA %A EDUARDO AUGUSTO G. BARBOSA %A Coura-vital, Wendel %A Góes-Neto, Aristóteles %A VASCO A.C. AZEVEDO %A Fernandes, Geraldo Wilson %I FapUNIFESP (SciELO) %V 93 %G eng %U https://doi.org/10.1590%2F0001-3765202120210431 %N suppl 3 %R 10.1590/0001-3765202120210431 %0 Journal Article %J Phys. Rev. D %D 2021 %T Post-Newtonian $\ensuremath\gamma$-like parameters and the gravitational slip in scalar-tensor and $f(R)$ theories %A Júnior D. Toniato %A Rodrigues, Davi C. %B Phys. Rev. D %I American Physical Society %V 104 %P 044020 %8 Aug %G eng %U https://link.aps.org/doi/10.1103/PhysRevD.104.044020 %R 10.1103/PhysRevD.104.044020 %0 Journal Article %J Journal of the Mechanical Behavior of Biomedical Materials %D 2021 %T Comparison between hydroxyapatite/soapstone and hydroxyapatite/reduced graphene oxide composite coatings: Synthesis and property improvement %A Daniel Nilson Nunes Nicomedes %A Laureana Moreira Mota %A Rebecca Vasconcellos %A Nathanael Vieira Medrado %A Michelle de Oliveira %A Érika Costa de Alvarenga %A Karyne R.C. Juste %A Ariete Righi %A Sara Matte Manhabosco %A Guilherme Jorge Brigolini Silva %A Fernando Gabriel S. Araújo %A de Oliveira, Alan Barros %A Ronaldo Junio Campos Batista %A Jaqueline dos Santos Soares %A Taíse Matte Manhabosco %K Biocompatibility %K Hydroxyapatite %K Pulsed electrodeposition %K rGO %K Soapstone talc %X Economic viability and eco-friendliness are important characteristics that make implants available to the population in a sustainable way. In this work, we evaluate the performance of a low-cost, widely available, and eco-friendly material (talc from soapstone) relative to reduced graphene oxide as reinforcement to brittle hydroxyapatite coatings. We employ a low-cost and straightforward technique, electrodeposition, to deposit the composite coatings on the titanium substrate. Corrosion, wear, and biocompatibility tests indicate that the reduced graphene oxide can be effectively replaced by talc without reducing the mechanical, anticorrosion, and biocompatible composite coatings properties. Our results indicate that talc from soapstone is a promising material for biomedical applications. %B Journal of the Mechanical Behavior of Biomedical Materials %V 121 %P 104618 %G eng %U https://www.sciencedirect.com/science/article/pii/S175161612100299X %R https://doi.org/10.1016/j.jmbbm.2021.104618 %0 Journal Article %J Review of Scientific Instruments %D 2021 %T White LED phototherapy as an improved treatment for neonatal jaundice %A Savedra,R. M. L. %A Fonseca,A. M. T. %A Silva,M. M. %A R.F. Bianchi %A M.F. Siqueira %B Review of Scientific Instruments %V 92 %P 064101 %G eng %U https://doi.org/10.1063/5.0046430 %N 6 %R 10.1063/5.0046430 %0 Journal Article %J J. Braz. Chem. Soc. %D 2021 %T In vitro Photoprotective Evaluation and Development of Novel Nanoemulsion with Chromone Derivative %A Amanda Antunes %A Ana Paula Gouveia %A Gabriela Diogo %A Taylor, Jason %A Lucas Sousa %A Tatiane Amparo %A Fernanda Perasoli %A Orlando dos Santos %A Cazati, Thiago %A Paula Vieira %A Ricardo Penido %A Viviane dos Santos %B J. Braz. Chem. Soc. %I Sociedade Brasileira de Quimica (SBQ) %G eng %U https://doi.org/10.21577%2F0103-5053.20210072 %R 10.21577/0103-5053.20210072 %0 Journal Article %J npj 2D Mater Appl %D 2021 %T Topological vectors as a fingerprinting system for 2D-material flake distributions %A Joyce C. C. Santos %A Prado, Mariana C. %A Helane L. O. Morais %A Samuel M. Sousa %A Elisangela Silva-Pinto %A Luiz G. Cançado %A Neves, Bernardo R. A. %B npj 2D Mater Appl %I Springer Science and Business Media LLC %V 5 %8 may %G eng %U https://doi.org/10.1038%2Fs41699-021-00234-z %N 1 %R 10.1038/s41699-021-00234-z %0 Journal Article %J Ceramics International %D 2021 %T Structural, optical, and magnetic evaluation of Co-, Ni-, and Mn-modified multiferroic BiFeO3 ceramics %A J.N.B. Sales %A R.T. da Silva %A L.R.S. Lara %A S.L.L.M. Ramos %A Soares, J. S. %A T.A.S. Soares %A G. Machado %A Manhabosco, S. M. %A de Oliveira, A. B. %A H.B. de Carvalho %A Batista, R. J. C. %A H.O. Stumpf %A T.M. Manhabosco %K A. powders: solid-state reaction %K C. Magnetic properties %K D. Ferrites %X Co-, Ni-, and Mn-doped BiFeO3 (BFO) ceramics were synthesized herein through a solid-state reaction. All doped BFO samples exhibit visible-light response, and the Co- and Ni-doped BFO samples present enhanced ferromagnetic order at room temperature. All doped samples show secondary phases in minor quantities. Optical spectra reveal two absorptions bands, indicating multiple electron transitions for BFO and its secondary phases. M − H hysteresis loops suggest enhanced ferromagnetism in the Co- and Ni-doped BFO samples because of magnetic spinel CFP and NFO phases, respectively, whereas changes in oxygen vacancies and Fe–O–Fe bond angle play minor roles in the ferromagnetic behavior. %B Ceramics International %G eng %U https://www.sciencedirect.com/science/article/pii/S0272884221015765 %R https://doi.org/10.1016/j.ceramint.2021.05.176 %0 Journal Article %J Revista Brasileira de Ensino de FÃ\-sica %D 2021 %T Fotografando com uma cÃ\textcentmera de pixel Ã\textordmasculinenico %A Alencar, Thonimar V. %A Carvalho, Edson J. %B Revista Brasileira de Ensino de FÃ\-sica %I scielo %V 43 %8 00 %G eng %U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-11172021000100712&nrm=iso %0 Journal Article %J Nano Res. %D 2021 %T Angle-tunable intersubband photoabsorption and enhanced photobleaching in twisted bilayer graphene %A Eva A. A. Pogna %A Xianchong Miao %A Driele von Dreifus %A Alencar, Thonimar V. %A Marcus V. O. Moutinho %A Pedro Venezuela %A Cristian Manzoni %A Minbiao Ji %A Giulio Cerullo %A Ana Maria de Paula %B Nano Res. %I Springer Science and Business Media LLC %8 jan %G eng %U https://doi.org/10.1007%2Fs12274-021-3288-0 %R 10.1007/s12274-021-3288-0 %0 Journal Article %J Physica A: Statistical Mechanics and its Applications %D 2021 %T Information, opinion and pandemic %A Américo T. Bernardes %A Leonardo Costa Ribeiro %K COVID-19 %K Opinion diffusion %K Pandemic %K SIR model %K Sznajd model %X The world’s population suffers a COVID-19 pandemic. By September 2020 nearly 1 million people had died. These are official numbers. The real cases might be much higher, due to under-reporting in many countries. Different strategies were adopted by national governments. Neglecting what was defined by sanitarian authorities, some politicians, at the beginning of the pandemic, declared that it would be a little flu, without consequences, lighter than seasonal flues. Some politicians propagated medicines with no scientific support. In many countries and regions, people became confused. The population’s reactions to these political positions may facilitate or block the virus spread. In this paper, we propose a model connecting the spreading of opinions with the propagation of a pandemic. We discuss how conflicting opinions can diffuse in the pandemic environment and the influence it has on the population’s behavior; how it may cause a greater or smaller number of infected individuals. %B Physica A: Statistical Mechanics and its Applications %V 565 %P 125586 %G eng %U https://www.sciencedirect.com/science/article/pii/S0378437120308840 %R https://doi.org/10.1016/j.physa.2020.125586 %0 Journal Article %J Recycling %D 2021 %T Mechanical Property Assessment of Interlocking Plastic Pavers Manufactured from Electronic Industry Waste in Brazil %A Luiz Tadeu Gabriel %A Rodrigo Fernando Bianchi %A Américo T. Bernardes %B Recycling %I MDPI AG %V 6 %P 15 %8 feb %G eng %U https://doi.org/10.3390%2Frecycling6010015 %N 1 %R 10.3390/recycling6010015 %0 Journal Article %J J. Braz. Chem. Soc. %D 2021 %T Trypanocidal Activity and Increased Solubility of Benznidazole Incorporated in PEG 4000 and Its Derivatives %A Lucas Sousa %A Maria Lu\'ıza Azevedo %A Dayana Rocha %A Ângela Andrade %A Tatiane Amparo %A Orlando dos Santos %A Jana\'ına Seibert %A Luciano Pereira %A Paula Vieira %A Cláudia Carneiro %A Ana Paula Barboza %A Bernardo Neves %A Policarpo Sales Jr. %A Silvane Murta %A Kátia Novack %A Viviane dos Santos %B J. Braz. Chem. Soc. %I Sociedade Brasileira de Quimica (SBQ) %G eng %U https://doi.org/10.21577%2F0103-5053.20210017 %R 10.21577/0103-5053.20210017 %0 Journal Article %J Cadernos de Astronomia %D 2021 %T Matéria escura e as estruturas cósmicas %A Velten, Hermano %B Cadernos de Astronomia %V 2 %P 58 %8 fev. %G eng %U https://www.periodicos.ufes.br/astronomia/article/view/33609 %N 1 %R 10.47456/Cad.Astro.v2n1.33609 %0 Journal Article %J Universe %D 2021 %T To conserve, or not to conserve: A review of nonconservative theories of gravity %A Velten, Hermano %A Caramês, Thiago R. P. %B Universe %V 7 %P 38 %G eng %N 2 %R 10.3390/universe7020038 %0 Journal Article %J Eur. Phys. J. Plus %D 2021 %T Newtonian-like gravity with variable G %A Júlio C. Fabris %A Tales Gomes %A Júnior D. Toniato %A Velten, Hermano %B Eur. Phys. J. Plus %I Springer Science and Business Media LLC %V 136 %8 jan %G eng %U https://doi.org/10.1140%2Fepjp%2Fs13360-021-01146-z %N 2 %R 10.1140/epjp/s13360-021-01146-z %0 Journal Article %J Notas Técnicas Cedeplar-UFMG %D 2020 %T Estimate of underreporting of COVID-19 in Brazil by Acute Respiratory Syndrome hospitalization reports %A Leonardo Costa Ribeiro %A Américo Tristão Bernardes %X The number of COVID-19 infected people in each country is a crucial factor to determine public policies. It guides the governments to strengthen movement restrictions of people or to relieve it. The number of infected people is very important to forecast the needs of the health systems, which are collapsing in many countries. Thus, underreporting of infected people is a huge problem, since authorities do not know the real problem and act in darkness. In the present work, we discuss this subject for the Brazilian case. We take the time series of acute respiratory syndromes reported in the health public system in the last ten years and estimated the number for March/20 when the COVID-19 appeared in Brazil. Our results show a 7.7:1 rate of underreporting, meaning that the real cases in Brazil should be, at least, seven times the publicized number. %B Notas Técnicas Cedeplar-UFMG %V xx %P xx %G eng %U https://ideas.repec.org/p/cdp/tecnot/tn010.html %N xx %0 Journal Article %J Nova Economia %D 2020 %T Os primeiros 80 dias da pandemia da COVID-19 em Belo Horizonte: da contenção à flexibilização %A Andrade, Monica Viegas %A Noronha, Kenya %A Turra, Cassio Maldonado %A Guedes, Gilvan %A Cimini, Fernanda AND Ribeiro %A Leonardo Costa %A Bernardes, Americo Tristao %A et. al. %X Este artigo examina o contexto e as implicações da pandemia por Covid-19 na cidade de Belo Horizonte (BH) nos primeiros 80 dias da doença. Utilizamos um recorte analítico descritivo para mensurar a evolução dos casos, o excesso de óbitos, a taxa de transmissibilidade do vírus e a pressão da doença sobre o sistema de saúde de BH e região, através da taxa de ocupação hospitalar nos leitos públicos. Além disso, identificamos as principais políticas de contenção adotadas pelas autoridades locais, bem como as implicações da redução do distanciamento social. Nossos resultados demonstram que o Sistema Único de Saúde (SUS), bem gerido, é fundamental para o enfrentamento da pandemia e a mitigação de suas consequências para a população. O processo de flexibilização que se inicia tem imposto novos desafios que requererão monitoramento atento das autoridades e da sociedade. %B Nova Economia %V 30 %P 701-737 %G eng %U https://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-63512020000200701&nrm=iso %N 0103-6351 %0 Journal Article %J Journal of Physics: Condensed Matter %D 2020 %T Crystal reorientation and plastic deformation of single-layer MoS2 and MoSe2 under uniaxial stress %A Ananias B Alencar %A Alan de Oliveira %A Chacham, Helio %X We investigate theoretically, through of first-principles calculations, the effect of the application of large in-plane uniaxial stress on single-layer of MoS2, MoSe2, and MoSSe alloys. For stress applied along the zigzag direction, we predict an anomalous behavior near the point fracture. This behavior is characterized by the reorientation of the MoS2 structure along the applied stress from zigzag to armchair due to the formation of transient square-lattice regions in the crystal, with an apparent (although not real) crystal rotation of 30 degrees. After reorientation, a large plastic deformation √3-1 remains after the stress is removed. This behavior is also observed in MoSe2 and in MoSSe alloys. This phenomenon is observed both in stress-constrained geometry optimizations and in ab initio molecular dynamics simulations at finite temperature and applied stress. %B Journal of Physics: Condensed Matter %G eng %U http://iopscience.iop.org/article/10.1088/1361-648X/abd5f5 %0 Journal Article %J Universe %D 2020 %T Post-Editorial of the Special Issue “Estate Quantistica Conference—Recent Developments in Gravity, Cosmology, and Mathematical Physics” %A Velten, Hermano %A Giuseppe Dito %B Universe %I MDPI AG %V 6 %P 240 %8 dec %G eng %U https://doi.org/10.3390%2Funiverse6120240 %N 12 %R 10.3390/universe6120240 %0 Journal Article %J Journal of Molecular Liquids %D 2020 %T Highly luminescent liquid crystals by connecting 1,3,4-oxadiazole with thiazolo[5,4-d]thiazole units %A Arthur B.S. de Santos %A Alex M. Manfredi %A Salla, Cristian A. M. %A Farias, Giliandro %A Edivandro Girotto %A Eccher, Juliana %A Eduard Westphal %A Curcio, Sergio F. %A Cazati, Thiago %A Ivani Malvestiti %A Eduardo H.L. Falcão %A Bechtold, Ivan H. %A Hugo Gallardo %K 1 %K 3 %K 4-Oxadiazole %K 4-]thiazole %K Fluorescence %K Liquid crystals %K Polycatenar %K Thiazolo[5 %X The direct bonding between a thiazolo[5,4-d]thiazole and two 1,3,4-oxadiazole units allowed us to create a new and versatile rigid core for luminescent liquid crystal, which showed interesting and variable mesomorphic and photophysical properties. From the 5-bis(5-phenyl-1,3,4-oxadiazol-2-yl)thiazolo[5,4-d]thiazole new core, three molecules with different number of alkoxy chains were synthesized and had their properties correlated with the molecular structure. The molecule with two chains showed a smectic C mesophase, while the mesogens with four and six chains presented hexagonal columnar mesomorphism, which was confirmed by POM and XRD measurements. In addition, the molecule with six chains presented liquid crystalline behavior close to room temperature. In solution, the molecules presented strong photoluminescence ranging from blue to yellow, with quantum yields higher than 0.6. Excited state lifetimes allowed to correlate the fluorescence component associated to the different emitting species to the molecular organization in spin coated films. The molecular energy levels, together with thermal stability and possible charge carrier transport due to molecular packing, suggest that these molecules are promising for optoelectronic applications. Overall, this work contributes to the development of the use of thiazolo[5,4-d]thiazole in liquid crystals, demonstrating its great efficiency and versatility. %B Journal of Molecular Liquids %P 114887 %G eng %U http://www.sciencedirect.com/science/article/pii/S0167732220371294 %R https://doi.org/10.1016/j.molliq.2020.114887 %0 Journal Article %J Beilstein J. Nanotechnol. %D 2020 %T Nanomechanics of few-layer materials: do individual layers slide upon folding? %A Batista, Ronaldo J. C. %A Dias, Rafael F. %A Barboza, Ana P. M. %A de Oliveira, Alan B. %A Manhabosco, Taise M. %A Thiago R. Gomes-Silva %A Andreij C. Gadellha %A Cassiano Rabelo %A Luiz G. L. Cançado %A Jorio, Ado %A Chacham, Hélio %A Neves, Bernardo R. A. %B Beilstein J. Nanotechnol. %V 11 %P 1801–1808 %G eng %R doi:10.3762/bjnano.11.162 %0 Journal Article %J Journal of Electronic Materials %D 2020 %T Electrical Impedance of V 2 O 5/POMA Hybrid Film Deposited by Casting for Application in Ammonia Gas Sensor %A Diniz, MO %A Coelho, RS %A R F Bianchi %A Guerra, EM %B Journal of Electronic Materials %I Springer %P 1–6 %G eng %0 Journal Article %J Carbon %D 2020 %T Hard, transparent, sp3-containing 2D phase formed from few-layer graphene under compression %A Luiz G. Pimenta Martins %A Diego L. Silva %A Jesse S. Smith %A Ang-Yu Lu %A Cong Su %A Marek Hempel %A Connor Occhialini %A Xiang Ji %A Ricardo Pablo %A Rafael S. Alencar %A Alan C.R. Souza %A Alysson A. Pinto %A de Oliveira, Alan B. %A Batista, Ronaldo J. C. %A Tomás Palacios %A Mazzoni, Mário S. C. %A Matos, Matheus J. S. %A Riccardo Comin %A Kong, Jing %A Luiz G. Cançado %X Despite several theoretically proposed two-dimensional (2D) diamond structures, experimental efforts to obtain such structures are in initial stage. Recent high-pressure experiments provided significant advancements in the field, however, expected properties of a 2D-like diamond such as sp3 content, transparency and hardness, have not been observed together in a compressed graphene system. Here, we compress few-layer graphene samples on SiO2/Si substrate in water and provide experimental evidence for the formation of a quenchable hard, transparent, sp3-containing 2D phase. Our Raman spectroscopy data indicates phase transition and a surprisingly similar critical pressure for two-, five-layer graphene and graphite in the 4-6 GPa range, as evidenced by changes in several Raman features, combined with a lack of evidence of significant pressure gradients or local non-hydrostatic stress components of the pressure medium up to ≈ 8 GPa. The new phase is transparent and hard, as evidenced from indentation marks on the SiO2 substrate, a material considerably harder than graphene systems. Furthermore, we report the lowest critical pressure (≈ 4 GPa) in graphite, which we attribute to the role of water in facilitating the phase transition. Theoretical calculations and experimental data indicate a novel, surface-to-bulk phase transition mechanism that gives hint of diamondene formation. %B Carbon %G eng %U http://www.sciencedirect.com/science/article/pii/S0008622320311179 %R https://doi.org/10.1016/j.carbon.2020.11.038 %0 Journal Article %J J. Mater. Chem. C %D 2020 %T Reducing Lifetime in Cu(I) Complexes with Thermally Activated Delayed Fluorescence and Phosphorescence promoted by Chalcogenolate-Diimine Ligand %A Farias, Giliandro %A Salla, Cristian A. M. %A da Silva Heying, Renata %A Bortoluzzi, Adailton J %A Curcio, Sergio %A Cazati, Thiago %A dos Santos, Paloma L. %A Monkman, Andrew P %A de Souza, Bernardo %A BECHTOLD, IVAN H %X Luminescent copper(I) complexes have drawn attention due to their promising performance as alternative optoelectronic materials to the well-known heavy transition metals complexes. Herein, we report the synthesis of six luminescent Cu(I) complexes with phosphines and 1,10-phenanthroline-derived ligands with thiadiazole and selenodiazole groups in order to evaluate the effect of heavy atom on their photophysical properties. Steady-state and time-resolved spectroscopy confirmed delayed fluorescence emission via a thermally activated delayed fluorescence mechanism in all cases. The experimental spectroscopic data was analyzed with detailed quantum-chemical calculations. Interestingly, these complexes did not show the expected “heavy atom effect”, that enhances the spin-orbit coupling matrix elements, but nevertheless the addition of the heavier chalcogens contributed to reduce the photoluminescence lifetime to roughly 800 ns, which is the lowest reported so far for such TADF materials. %B J. Mater. Chem. C %I The Royal Society of Chemistry %P - %G eng %U http://dx.doi.org/10.1039/D0TC03660A %R 10.1039/D0TC03660A %0 Journal Article %J Toxicology in Vitro %D 2020 %T Association of electroanalytical and spectrophotometric methods to evaluate the antioxidant activity of isobenzofuranone in primary cultures of hippocampal neurons %A Aniely dos Reis Teixeira %A Róbson Ricardo Teixeira %A Iara Mariana Lellis Ribeiro %A Wagner Luiz Pereira %A Taise Matte Manhabosco %A de Brito, Ana Carolina Ferreira %A Laser Antônio Machado Oliveira %A Katiane de Oliveira %A Pinto Coelho Nogueira %K Antioxidants %K Cyclic voltammetry %K Free radicals %K Hippocampal neurons %K Isobenzofuranones %K Spectrophotometric methods %X The isobenzofuran-1(3H)-ones (phthalides) exhibit various biological activities, including antioxidant activity on reactive oxygen species (ROS). An excess of ROS that cannot be naturally contained by cellular enzymatic systems is called redox imbalance, which damage cell membranes, proteins, and DNA, thereby possibly triggering neuronal death in several neurodegenerative diseases. Considering our ongoing efforts to find useful compounds to control redox imbalance, herein we evaluated the antioxidant activity of two phtalides (compounds 3 and 4), using primary cultures of hippocampal neurons. Spectrophotometric assays showed that compound 3 significantly reduced (p ≤ 0.05) ROS levels and lipid peroxidation compared to the control treatment, while compound 4 was unable at any of the tested concentrations. Despite their structural similarity, these compounds behave differently in the intracellular environment, which was reliably corroborated by the determination of oxidation potentials via cyclic voltammetry. It was demonstrated that compound 3 presents a lower oxidation potential. The combination of the mentioned methods allowed us to find a strong correlation between the chemical structure of compounds and their biological effects. Taking together, the results indicate that compound 3 presents desirable characteristics to act as a candidate pharmacological agent for use in the prevention and treatment of neurodegenerative diseases. %B Toxicology in Vitro %P 104970 %G eng %U http://www.sciencedirect.com/science/article/pii/S0887233320305208 %R https://doi.org/10.1016/j.tiv.2020.104970 %0 Journal Article %J New J. Chem. %D 2020 %T Synthesis, Photophysical and Electrochemical Properties of Novel and Highly Fluorescent Difluoroboron Flavanone β-Diketonate Complexes %A Paez, Elida Betania Ariza %A Curcio, Sergio %A Neme, Natália %A Matos, Matheus %A Correa, Rodrigo S. %A Pereira, Fabio Junio %A Hilário, Flaviane Francisco %A Cazati, Thiago %A Taylor, Jason Guy %X Difluoroboron β-diketonates complexes are highly luminescent with extensive properties such as their fluorescence both in solution and in solid state and their high molar extinction coefficients. Due to their rich optical properties, these compounds have been studied for their applications in organic electronics such as in self-assembly and applications in biosensors, bio-imaging and optoelectronic devices. The easy and fast synthesis of difluoroboron β-diketonate (BF2dbm) complexes makes their applications even more attractive. Although many different types of difluoroboron β-diketonates complexes have been studied, the cyclic flavanone analogues of these compounds have never been reported in the literature. Therefore, the present work aims to synthesize difluouroboron flavanone β-diketonate complexes, study their photophysical and electrochemical properties and assess their suitability for applications in optoelectronic devices. The synthesis was based on a Baker–Venkataraman reaction which initially provided substituted diketones, which were subsequently reacted with aldehydes to afford the proposed flavanones. The complexation was achieved by reacting flavanones and BF3. Et2O and in total 9 novel compounds were obtained. A representative difluoroboron flavanone complex was subjected to single crystal X-ray diffraction to unequivocally confirm the chemical structure. A stability study indicated only partial degradation of these compounds over a few days in a protic solvent at elevated temperatures. Photophysical studies revealed that the substituent groups and the solvent media significantly influence the electrochemical and photophysical properties of the final compounds, especially the molar absorption coefficient, fluorescence quantum yields, and the band gap. Moreover, the compounds exhibited a single excited-state lifetime in all studied solvent. Computational studies were employed to evaluate ground and excited states properties and carry out DFT and TDDFT level analysis. These studies clarify the role of each state in the experimental absorption spectra as well as the effect of the solvent. %B New J. Chem. %I The Royal Society of Chemistry %P - %G eng %U http://dx.doi.org/10.1039/D0NJ03525D %R 10.1039/D0NJ03525D %0 Journal Article %J Cadernos de Astronomia %D 2020 %T Matéria escura, energia escura e a busca por uma nova teoria para a gravitação %A Velten, Hermano %B Cadernos de Astronomia %V 1 %P 40-51 %8 jul. %G eng %U https://periodicos.ufes.br/astronomia/article/view/31674 %N 1 %R 10.47083/Cad.Astro.v1n1.31674 %0 Journal Article %J Cadernos de Astronomia %D 2020 %T Astrobiologia: como modelar o crescimento de organismos na Terra e em exoplanetas %A Pinheiro, Carlos Felipe Saraiva %A Castro e Silva, Alcides %A Velten, Hermano %B Cadernos de Astronomia %V 1 %P 116-122 %8 jul. %G eng %U https://periodicos.ufes.br/astronomia/article/view/31097 %N 1 %R 10.47083/Cad.Astro.v1n1.31097 %0 Journal Article %J QuÃ\-mica Nova %D 2020 %T Novel PEG 4000 derivatives and its use in controlled release of drug indomethacin %A Nascimento, LÃ\textordmasculinebia G. %A Lopes, Suellen A. %A Teodolino, Ayron B. L. %A Novack, KÃ!`tia M. %A Barboza, Ana Paula M. %A Neves, Bernardo R. A. %A Azevedo, Maria Luiza S. %A Sousa, Lucas R. D. %A M. R. dos Santos, Viviane %B QuÃ\-mica Nova %I scielo %V 43 %P 685 - 691 %8 06 %G eng %U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422020000600685&nrm=iso %0 Journal Article %J Physics of the Dark Universe %D 2020 %T On (non-)dynamical dark energy %A Zimdahl, Winfried %A Júlio C. Fabris %A Velten, Hermano %A Ramón Herrera %X The current Universe is composed by a mixture of relativistic species, baryonic matter, dark matter and dark energy which evolve in a non-trivial way at perturbative level. An advanced description of the cosmological dynamics should include non-standard features beyond the simplistic approach idealized by the standard cosmology in which cosmic components do not interact, are adiabatic and dissipationless. We promote a full perturbative analysis of linear scalar perturbations of a non-interacting cosmological model containing baryons, dark matter (both pressureless) and a scalar field allowing for the presence of relative entropic perturbations between the three fluids. Assuming an effective scalar-field sound speed equal to one and neglecting anisotropic stresses we establish a new set of equations for the scalar cosmological perturbations. As a consequence of this new approach, we show that tiny departures from a constant scalar field equation of state wS=−1 damage structure formation in a non-acceptable manner. Hence, by strongly constraining wS our results provide compelling evidence in favor of the standard cosmological model and rule out a large class of dynamical dark energy models. %B Physics of the Dark Universe %V 30 %P 100681 %G eng %U http://www.sciencedirect.com/science/article/pii/S2212686420303125 %R https://doi.org/10.1016/j.dark.2020.100681 %0 Journal Article %J Materials Chemistry and Physics %D 2020 %T A new theranostic system for bone disorders: Functionalized folate-MDP hydroxyapatite nanoparticles with radiolabeled copper-64 %A Marcelo Fernandes Cipreste %A Wagner [da Nova Mussel] %A Juliana [Batista da Silva] %A Maria [Betânia de Freitas Marques] %A Ronaldo Junio [Campos Batista] %A Pedro Lana Gastelois %A Waldemar [Augusto de Almeida Macedo] %A Edésia Martins [Barros de Sousa] %K Copper-64 %K Folate %K Hydroxyapatite nanoparticles %K Medronate %K Theranostic system %X Hydroxyapatite nanoparticles have been investigated as biological agents for the treatment and diagnosis of bone diseases due to their properties, providing high affinity to bone tissues and also due to the possibility to chemically modify the surfaces of these nanoparticles to provide active targeting to bone tumors or other bone disorders. In this work, synthetic hydroxyapatite nanoparticles and their surface modifications with folic and medronic acid were studied. Copper-64 was produced by neutron irradiation in a TRIGA MARK I nuclear reactor, and the functionalized nanoparticles radiolabeled with this radioisotope. The multi-technique characterization includes FTIR, PXRD, TGA, DSC, CHN, Zeta potential, XPS, SEM, TEM, and Gamma spectroscopy. Furthermore, the evaluation of the chemical interaction stability was through leaching tested for efficiency. The results indicate that folic and medronic acids can be covalently bonded to HA surface, producing a new material not yet described in the literature, been stably attached to hydroxyapatite nanoparticle surfaces, able to provide active targeting for bone disorders. The complexation of copper-64 provides high radiochemistry purity, although the specific activity must be improved. %B Materials Chemistry and Physics %P 123265 %G eng %U http://www.sciencedirect.com/science/article/pii/S0254058420306350 %R https://doi.org/10.1016/j.matchemphys.2020.123265 %0 Journal Article %J Vibrational Spectroscopy %D 2020 %T Growth and vibrational spectroscopy of K2LiyNixCo1-xSO42.6H2O (y=0.1;0.2;0.3;0.4) crystals %A Tiago S. Pacheco %A Zélia M.C. Ludwig %A Diogo R. Sant’Anna %A Genivaldo J. Perpétuo %A Carlos J. Franco %A Edinei C. Paiva %A Santunu Ghosh %K Chemical Analysis %K Crystal growth %K Optical Energy Gap %K Raman Spectroscopy %K Tutton’s Salt %X The mixed crystals of the Tutton’s salt doped with Li following the empirical formula K2LiyNixCo1-x (SO4)2.6H2O, were synthesized from the slow evaporation of the solvent at constant temperature. The presence of K, S, Ni, Co and O elements in the studied crystalline structure was confirmed by EDS spectroscopy using a scanning electron microscope and their quantification including Li was carried out with the help of ICP-OES technique. Raman spectroscopy in the range 100−3600 cm−1, confirmed the presence of tetrahedral (SO4), octahedral complexes Ni(H2O)6, Co(H2O)6, and H2O molecules in the crystal structure. Our UV–vis studies have shown that the mixed crystals have good optical transparency in the ultraviolet (200−350 nm) and infrared (750−1000 nm) region. The direct and indirect optical energy gap of the synthesized crystals were determined from the Tauc’s plot. XRD diffractograms of the sample crystals do not show any specific changes due to the presence of Li ion in the crystalline network. %B Vibrational Spectroscopy %V 109 %P 103093 %G eng %U http://www.sciencedirect.com/science/article/pii/S0924203120300965 %R https://doi.org/10.1016/j.vibspec.2020.103093 %0 Journal Article %J PeerJ %D 2020 %T Severe airport sanitarian control could slow down the spreading of COVID-19 pandemics in Brazil %A Ribeiro, Sérvio Pontes %A Castro e Silva, Alcides %A Dáttilo, Wesley %A Reis, Alexandre Barbosa %A Góes-Neto, Aristóteles %A Alcantara, Luiz Carlos Junior %A Giovanetti, Marta %A Coura-vital, Wendel %A Fernandes, Geraldo Wilson %A Azevedo, Vasco Ariston C. %K Amazonia %K Indigenous people %K Metapopulation dynamics %K One-Ecohealth %K SARS-CoV-2 pandemic %K SIR model %X Background We investigated a likely scenario of COVID-19 spreading in Brazil through the complex airport network of the country, for the 90 days after the first national occurrence of the disease. After the confirmation of the first imported cases, the lack of a proper airport entrance control resulted in the infection spreading in a manner directly proportional to the amount of flights reaching each city, following the first occurrence of the virus coming from abroad. Methodology We developed a Susceptible-Infected-Recovered model divided in a metapopulation structure, where cities with airports were demes connected by the number of flights. Subsequently, we further explored the role of the Manaus airport for a rapid entrance of the pandemic into indigenous territories situated in remote places of the Amazon region. Results The expansion of the SARS-CoV-2 virus between cities was fast, directly proportional to the city closeness centrality within the Brazilian air transportation network. There was a clear pattern in the expansion of the pandemic, with a stiff exponential expansion of cases for all the cities. The more a city showed closeness centrality, the greater was its vulnerability to SARS-CoV-2. Conclusions We discussed the weak pandemic control performance of Brazil in comparison with other tropical, developing countries, namely India and Nigeria. Finally, we proposed measures for containing virus spreading taking into consideration the scenario of high poverty. %B PeerJ %V 8 %P e9446 %G eng %U https://doi.org/10.7717/peerj.9446 %R 10.7717/peerj.9446 %0 Journal Article %J Revista Brasileira de Farmacognosia %D 2020 %T Green Propolis: In Vitro Photoprotective and Photostability Studies of Single and Incorporated Extracts in a Sunscreen Formulation %A Almeida, Wanessa Aparecida da Silveira %A Sousa, Lucas Resende Dutra %A dos Santos Antunes, Amanda %A de Azevedo, Amanda Scofield %A do Nascimento, Andréa Mendes %A Amparo, Tatiane Roquete %A de Souza, Gustavo Henrique Bianco %A dos Santos, Orlando David Henrique %A Andrade, Ã?ngela Leão %A Cazati, Thiago %A de Abreu Vieira, Paula Melo %A Bueno, Paula Carolina Pires %A dos Santos, Viviane Martins Rebello %X Propolis is a natural, non-toxic resin produced by honey bees that has been used for hundreds of years for its biological activities, such as antimicrobial, anti-inflammatory, anesthetic, cytostatic, and cariostatic properties. Currently, it is used in food, pharmaceutical, and cosmetic industries. The aim of this work was to evaluate the antioxidant activity, sun protection factor, and photostability of different hydroalcoholic extracts of green propolis. All extracts prepared presented high absorption in the UVB region. The extract of 70% green propolis (high temperature) was incorporated into Gel Permulen TR-1. This new formulation presented a higher value of sun protection factor. Besides that, the formulation developed with Gel Permulen TR-1 and the hydroalcoholic extract of 70% green propolis (high temperature) showed good photostability and it was safe to be applied on the skin according the HET-CAM test. These results indicated the potential of hydroalcoholic extracts of 70% green propolis (high temperature) for use in sunscreen. %B Revista Brasileira de Farmacognosia %G eng %U https://doi.org/10.1007/s43450-020-00071-z %R 10.1007/s43450-020-00071-z %0 Journal Article %J Journal of Applied Polymer Science %D 2020 %T Partially ordered porous structures on layer-by-layer polyaniline/poly(vinyl sulfate sodium) ultrathin films: Easy fabrication of robust submicroscopic patterning %A Faria, A. M. A. %A Miranda, M. A. %A Gonçalves, G. E. %A R.F. Bianchi %A A.G.C. Bianchi %A Cuba, C. %A Neves, B. R. A. %A Pinto, E. S. %X ABSTRACT The use of polyaniline (PANI) as a conductive material has steadily increased in recent years due to its interesting physicochemical properties, low manufacturing cost, and easy processing. This conductive material, associated with the diffraction properties of organized nanostructures in thin films, has excellent application potential in microelectronics and photonic devices. Initially, this work presents improvement routes for the breath figure method (a nanopatterning technique) in polystyrene (PS) films through the control of film deposition parameters and the presence of water in the polymer solution. Such improvements are then extended to the production of PANI nanostructures, in the form of pores, from patterned porous PS films. Consequently, PANI films with a partially ordered pore structure (mean pore diameter of 100 nm) are produced in a facile and easily scalable method. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48597. %B Journal of Applied Polymer Science %V 137 %P 48597 %G eng %U https://onlinelibrary.wiley.com/doi/abs/10.1002/app.48597 %N 17 %R 10.1002/app.48597 %0 Journal Article %J Carbon %D 2020 %T Oxygen intercalated graphene on SiC(0001): Multiphase SiOx layer formation and its influence on graphene electronic properties %A Igor Antoniazzi %A Chagas, Thais %A Matos, Matheus J. S. %A Lucas A.B. Marçal %A Edmar A. Soares %A Mazzoni, Mário S. C. %A Roberto H. Miwa %A João Marcelo J. Lopes %A Ângelo Malachias %A Rogério Magalhães-Paniago %A Myriano H. Oliveira %X Low-dimensionality materials are highly susceptible to interfaces. Indeed, intercalation of different chemical species in between epitaxial graphene and silicon carbide (SiC), for instance, may decouple the graphene with respect to the substrate due to the conversion of the buffer layer into a graphene layer. O-intercalation is known to release the strain of such 2D material and to lead to the formation of high structural quality AB-stacked bilayer graphene. Nonetheless, this interface transformation concomitantly degrades graphene electronic transport properties. In this work we employed different techniques in order to better understand the structure of the graphene/SiC interface generated by O-intercalation and to elucidate the origin of the poor electronic properties of graphene. Experimental results revealed the formation of a SiO2 rich layer with a defective transition layer in between it and the SiC, which is characterized by the existence of silicon oxycarbide structures. Scanning tunneling spectroscopy measurements revealed an extensive presence of electronic states just around the Fermi level all over the sample surface, which may suppress the charge carriers mobility around this region. According to theoretical calculations, such states are mainly due to the formation of silicon oxicarbides within the interfacial layer. %B Carbon %G eng %U http://www.sciencedirect.com/science/article/pii/S0008622320305054 %R https://doi.org/10.1016/j.carbon.2020.05.064 %0 Journal Article %J Chemical Physics %D 2020 %T Water Diffusion in Carbon Nanotubes Under Directional Electric Fields: Coupling Between Mobility and Hydrogen Bonding %A Débora N. [de Freitas] %A Bruno H.S. Mendonça %A Mateus H. Köhler %A Barbosa, Marcia C. %A Matos, Matheus J. S. %A Batista, Ronaldo J. C. %A Alan B. [de Oliveira] %K Carbon nanotube %K Electric Fields %K Hydrogen Bonds %K Water %X Molecular Dynamics simulations of water confined in carbon nanotubes subjected to external electric fields show that water mobility strongly depends on the confining geometry, the intensity and directionality of the electric field. While fields forming angles of 0° and 45° slow down the water dynamics by increasing organization, perpendicular fields can enhance water diffusion by decreasing hydrogen bond formation. For 1.2 diameter long nanotubes, the parallel field destroys the ice-like water structure increasing mobility. These results indicate that the structure and dynamics of confined water are extremely sensitive to external fields and can be used to facilitate filtration processes. %B Chemical Physics %P 110849 %G eng %U http://www.sciencedirect.com/science/article/pii/S0301010420301592 %R https://doi.org/10.1016/j.chemphys.2020.110849 %0 Journal Article %J Frontiers in Chemistry %D 2020 %T Synthesis of 2,1,3-Benzoxadiazole Derivatives as New Fluorophores—Combined Experimental, Optical, Electro, and Theoretical Study %A Frizon, Tiago E. A. %A Vieira, André A. %A da Silva, Fabricia N. %A Saba, Sumbal %A Farias, Giliandro %A de Souza, Bernardo %A Zapp, Eduardo %A Lôpo, Michell N. %A Braga, Hugo de C. %A Grillo, Felipe %A Curcio, Sergio F. %A Cazati, Thiago %A Rafique, Jamal %X Herein, we report the synthesis and characterization of fluorophores containing a 2,1,3-benzoxadiazole unit associated with a π-conjugated system (D-π-A-π-D). These new fluorophores in solution exhibited an absorption maximum at around 419 nm (visible region), as expected for electronic transitions of the π-π* type (ε 2.7 × 107 L mol−1 cm−1), and strong solvent-dependent fluorescence emission (ΦFL 0.5) located in the bluish-green region. The Stokes' shift of these compounds is ca. 3,779 cm−1, which was attributed to an intramolecular charge transfer (ICT) state. In CHCl3 solution, the compounds exhibited longer and shorter lifetimes, which was attributed to the emission of monomeric and aggregated molecules, respectively. Density functional theory was used to model the electronic structure of the compounds 9a–d in their excited and ground electronic states. The simulated emission spectra are consistent with the experimental results, with different solvents leading to a shift in the emission peak and the attribution of a π-π* state with the characteristics of a charge transfer excitation. The thermal properties were analyzed by thermogravimetric analysis, and a high maximum degradation rate occurred at around 300°C. Electrochemical studies were also performed in order to determine the band gaps of the molecules. The electrochemical band gaps (2.48–2.70 eV) showed strong correlations with the optical band gaps (2.64–2.67 eV). %B Frontiers in Chemistry %V 8 %P 360 %G eng %U https://www.frontiersin.org/article/10.3389/fchem.2020.00360 %R 10.3389/fchem.2020.00360 %0 Journal Article %J medRxiv %D 2020 %T Severe airport sanitarian control could slow down the spreading of COVID-19 pandemics in Brazil %A Ribeiro, Servio Pontes %A Dattilo, Wesley %A Castro e Silva, Alcides %A Reis, Alexandre Barbosa %A Goes-Neto, Aristoteles %A Alcantara, Luiz %A Giovanetti, Marta %A Fernandes, Geraldo Wilson %A Azevedo, Vasco Ariston %A Coura-vital, Wendel %X Background. We investigated a likely scenario of COVID-19 spreading in Brazil through the complex airport network of the country, for the 90 days after the first national occurrence of the disease. After the confirmation of the first imported cases, the lack of a proper airport entrance control resulted in the infection spreading in a manner directly proportional to the amount of flights reaching each city, following first occurrence of the virus coming from abroad. Methodology. We developed a SIR (Susceptible-Infected-Recovered) model divided in a metapopulation structure, where cities with airports were demes connected by the number of flights. Subsequently, we further explored the role of Manaus airport for a rapid entrance of the pandemic into indigenous territories situated in remote places of the Amazon region. Results. The expansion of the SARS-CoV-2 virus between cities was fast, directly proportional to the airport closeness centrality within the Brazilian air transportation network. There was a clear pattern in the expansion of the pandemic, with a stiff exponential expansion of cases for all cities. The more an airport showed closeness centrality, the greater was its vulnerability to SARS-CoV-2. Conclusions. We discussed the weak pandemic control performance of Brazil in comparison with other tropical, developing countries, namely India and Nigeria. Finally, we proposed measures for containing virus spreading taking into consideration the scenario of high poverty.Competing Interest StatementThe authors have declared no competing interest.Funding StatementFunding by CNPqAuthor DeclarationsAll relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript.YesAll necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesI state all data will be available in submission material %B medRxiv %I Cold Spring Harbor Laboratory Press %G eng %U https://www.medrxiv.org/content/early/2020/03/27/2020.03.26.20044370 %R 10.1101/2020.03.26.20044370 %0 Journal Article %J International Journal of Modern Physics A %D 2020 %T Viscous effects in the dark sector of the Universe %A Fabris, J. C. %A Caramês, T. R. P. %A Wojnar, A. %A Velten, H. E. S. %X Viscous properties are attributed to the dark sector of the Universe. They contribute to the accelerated expansion phase of the Universe and can alleviate existing tensions in the ΛCDM model at small scales. We provide a short review of recent efforts on this topic. Different viscous models for the dark sector are analysed both from theoretical and observational point of view. %B International Journal of Modern Physics A %V 35 %P 2040041 %G eng %U https://doi.org/10.1142/S0217751X20400412 %N 02n03 %R 10.1142/S0217751X20400412 %0 Journal Article %J Phys. Rev. D %D 2020 %T Skewness of matter distribution in clustering dark energy cosmologies %A Velten, Hermano %A Fazolo, Raquel Emy %B Phys. Rev. D %I American Physical Society %V 101 %P 023518 %8 Jan %G eng %U https://link.aps.org/doi/10.1103/PhysRevD.101.023518 %R 10.1103/PhysRevD.101.023518 %0 Journal Article %J Phys. Rev. D %D 2020 %T Is the Hubble diagram of quasars in tension with concordance cosmology? %A Velten, Hermano %A Gomes, Syrios %B Phys. Rev. D %I American Physical Society %V 101 %P 043502 %8 Feb %G eng %U https://link.aps.org/doi/10.1103/PhysRevD.101.043502 %R 10.1103/PhysRevD.101.043502 %0 Journal Article %J Journal of Physics: Condensed Matter %D 2020 %T Oxidation-driven formation of precisely ordered antimonene nanoribbons %A Alan Souza %A Matheus J S Matos %A Mario S C Mazzoni %X The control of geometric structure is a key aspect in the interplay between theoretical predictions and experimental realization in the science and applications of nanomaterials. This is particularly important in one-dimensional structures such as nanoribbons, in which the edge morphology dictates most of the electronic behavior in low energy scale. In the present work we demonstrate by means of first principles calculations that the oxidation of few-layer antimonene may lead to an atomic restructuring with formation of ordered multilayer zig-zag nanoribbons. The widths are uniquely determined by the number of layers of the initial structure, allowing the synthesis of ultranarrow ribbons and chains. We also show that the process may be extended to other compounds based on group V elements, such as arsenene. The characterization of the electronic structure of the resulting ribbons shows an important effect of stacking on band gaps and on modulation of electronic behavior. %B Journal of Physics: Condensed Matter %I IOP Publishing %8 jan %G eng %U https://doi.org/10.1088%2F1361-648x%2Fab678b %R 10.1088/1361-648x/ab678b %0 Journal Article %J Revista Brasileira de Ensino de FÃ\-sica %D 2019 %T RadiaÃ\SÃ\poundso de baixa frequÃ\textordfemeninencia e possÃ\-vel influÃ\textordfemeninencia nociva a sistemas biolÃ\textthreesuperiorgicos %A Rodrigues, F.G.F. %A Brizola, A. %B Revista Brasileira de Ensino de FÃ\-sica %I scielo %V 41 %8 00 %G eng %U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-11172019000300413&nrm=iso %0 Journal Article %J Revista Conexões %D 2019 %T O que conhecemos de todos o cosmos? %A Hermano Endlich Schneider Velten %X