Otimização das propriedades de barreira de um sistema em multicamada para absorção seletiva da luz solar

Dissertação de mestrado em Física - Formação Contínua de ProfessoresO presente trabalho tem como principal objetivo o desenvolvimento e otimização de um sistema de multicamadas para absorção seletiva da radiação solar. Para isso, prepararam-se revestimentos das camadas individuais de TiAlNx, TiAlNxOy e SiO2 com diferentes condições de deposição, essencialmente através da variação do fluxo dos gases reativos. As duas primeiras camadas foram depositadas por pulverização catódica em magnetrão e a última por deposição química de vapores (CVD). Em seguida, realizou-se a caracterização ótica destas camadas individuais por medidas de transmitância e refletância para efetuar o respetivo cálculo das contantes óticas espetrais, com o auxílio do software SCOUT. Por fim, utilizando as constantes óticas das camadas individuais, efetuou-se a simulação de uma multicamada, com os requisitos definidos em termos de perfil ótico e as espessuras obtidas para a amostra 1 foram de 65 nm para a camada de TiAlNx (com fluxo de N2 de 2,5 sccm), de 51 nm para a camada de TiAlNxOy (com fluxo de N2/O2 de 4,25 sccm) e 100 nm para a de SiO2. A deposição desta multicamada foi efetuada de acordo com as espessuras e parâmetros considerados na simulação. Com esta amostra 1 obteve-se uma emissividade de 8% e um coeficiente de absorção solar de 95,50%. A amostra foi sujeita a um tratamento térmico ao ar durante 600 h a 278ºC, sendo que o coeficiente de absorção diminuiu 0,39% e a emissividade aumentou 1%, apresentando assim um critério de desempenho de 0,009, o que garante uma durabilidade de 25 anos se implementado numa aplicação de aquecimento de água para uso doméstico. Com o intuito de estudar a influência do número de camadas, mantendo a espessura total, na resistência à corrosão dos revestimentos para absorção seletiva da luz solar produziram-se três novas multicamadas, do tipo (TiAlNx/TiAlNxOy)n/SiO2 (n inteiro de 1 a 5) tendo por base as espessuras de TiAlNx e de TiAlNxOy da amostra 1. Para isso, em vez de duas camadas (nitreto e oxinitreto) foram depositadas 5, 9 e 11 camadas, respetivamente (n= 2, 4 e 5) com deposição alternada de nitreto e oxinitreto, de modo que a espessura total em cada amostra continuasse a mesma. Todas estas amostras tinham um coeficiente de absorção menor que o da amostra 1. Em termos de resistência à oxidação o desempenho destas amostras foi também inferior ao da amostra 1, embora só a amostra com 11 camadas (n=5) não tenha passado o critério de desempenho.The main objective of this work is the development and optimization of a multilayer system for selective absorption of solar radiation. In order to achieve our aim, individual layers of TiAlNx, TiAlNxOy and SiO2 were prepared with different deposition conditions, mainly by varying the flow of reactive gases. The first two layers were deposited by magnetron sputtering and the latter by chemical vapour deposition (CVD). The next step was performed the optical characterization of these individual layers by reflectance and transmittance measurements and the respective calculation of spectral optical constants by the use of the SCOUT software. Finally, by using the optical constants of the individual layers, it was performed a simulation of a multilayer with the defined requisites in terms of optical profile and the thicknesses obtained for sample 1 were 65 nm for the layer TiAlNx (with N2 flow of 2.5 sccm), 51 nm for the layer TiAlNxOy (with the N2/O2 flow of 4.25 sccm) and 100 nm for SiO2. The deposition of multilayer was conducted in accordance with the thicknesses and parameters considered in the simulation. For sample 1 the emissivity was 8% and the solar absorption coefficient was 95.50%. The sample was subjected to a heat treatment during 600 h at 278ºC, the absorption coefficient decreased 0.39% and the emissivity increased 1%, thus presenting a performance criterion of 0,009, which ensures a durability of 25 years if implemented in an application for heating water for domestic use. In order to study the influence of the number of layers, keeping the total thickness, in the corrosion resistance of coatings for selective absorption of solar light three new multilayer were produced: (TiAlNx/TiAlNxOy)n/SiO2 ( n integer 1 to 5) based on the thickness of TiAlNx and TiAlNxOy of sample 1. For this purpose, instead of two layers (nitride and oxynitride) 5, 9 and 11 layers were deposited, respectively (n = 2, 4 and 5) with alternated deposition of nitride and oxynitride, so that the overall thickness in each sample remained unchanged. All these samples had a smaller absorption coefficient than that of sample 1. As far as oxidation resistance is concerned the performance of these samples was also inferior to that of sample 1, although the sample with 11 layers (n=5) has not passed the performance criterion

Four cases of cell cannibalism in highly malignant feline and canine tumors

Four cases of tumors in which cell internalization was frequently visualized are reported: one feline mammary carcinoma, one feline cutaneous squamous cell carcinoma, one canine pulmonary squamous cell carcinoma and one canine pleural mesothelioma. Cell internalization was observed by cytology in two of these cases (the feline mammary tumour and the pleural effusion in the canine mesothelioma) and by histopathology in all but the canine mesothelioma. Immunohistochemical staining for pancytokeratin was positive for both internalized and host cells, while E-cadherin expression was frequently absent, although internalized cells occasionally stained positive. This cell-to-cell interaction seems to be associated with tumors displaying a strong epithelial-mesenchymal transitional phenotype, in which cancer cells become engulfed by other cancer cells. Such event could be regarded as an important hallmark of very high malignancy.This work was supported by ‘Fundação para a Ciência e Tecnologia’ through the Project PEst-OE/AGR/U10276/2014 and through PhD fellowship SFRH/BD/70720/2010

Asphalt binder "Skincare"? aging evaluation of an asphalt binder modified by Nano-TiO2

Aging by oxidation of asphalt roadway material promotes changes in its physical, chemical, and rheological properties, affecting its hardening and accelerating the degradation of its corresponding asphalt mixture. Titanium dioxide (TiO2) has been applied in engineering investigations to promote anti-aging and photocatalytic properties. In this study, a commercial binder was modified with nano-TiO2 (using contents of 0.1, 0.25, 0.5, 1, 2, 3, and 6%). It was evaluated by physicochemical and rheological tests (penetration, softening point, mass loss, dynamic viscosity, rheology, and Fourier transform infrared spectroscopy-FTIR) before and after aging by rolling thin-film oven test (RTFOT) and pressure aging vessel (PAV). The results indicated that incorporating nano-TiO2 mitigates binder aging, pointing out 0.25% as an optimum modification content for the investigated asphalt binder.This research was partially funded by the Portuguese Foundation for Science and Technology (FCT), PhD scholarship SFRH/BD/137421/2018, NanoAir PTDC/FISMAC/6606/2020, UIDB/04650/2020, and UIDB/04029/2020. V.C.B. would like to acknowledge National Council for Scientific and Technological Development (CNPq) for the funding on behalf of the scholarship 308360/2017-6. Furthermore, we would like to thank the Industrial Research Fund (IOF) for funding the PAPPoA project (IOF/SBO/41859/2020)

ENVIRONMENTAL AGENDA IN PUBLIC ADMINISTRATION: PRIORITY AXES FOR THE SECRETARIAT OF FINANCE IN THE CITY OF MANAUS, BRAZIL

The Environmental Agenda in Public Administration (A3P) emerges as an essential tool for the modernization of Brazilian public management. This study aimed to identify the priority axes and actions capable of structuring an A3P for the Municipal Finance Secretariat (SEMEF) of the municipality of Manaus. A qualitative study was carried out, whose respondents are SEMEF managers, consulted based on interview script, whose data were organized with word processors, analyzed with content analysis tools, and interpreted based on the similarities and differences in the respondents' positions. The results showed that the rational use of resources, adequate waste management, sustainable construction, and quality of life at work were the four axes considered priorities to structure the A3P. The conclusion shows that the axes, initiatives, and results found are consistent with the philosophy and practice intended by A3P.La Agenda Ambiental en la Administración Pública (A3P) surge como una herramienta esencial para la modernización de la gestión pública brasileña. Este estudio tuvo como objetivo identificar los ejes y acciones prioritarios capaces de estructurar un A3P para la Secretaría de Hacienda Municipal (SEMEF) del municipio de Manaus. Se realizó un estudio cualitativo, cuyos encuestados son gerentes de la SEMEF, consultados en base a guión de entrevista, cuyos datos fueron organizados con procesadores de texto, analizados con herramientas de análisis de contenido e interpretados en base a las similitudes y diferencias en las posiciones de los encuestados. Los resultados mostraron que el uso racional de los recursos, la adecuada gestión de residuos, la construcción sustentable y la calidad de vida en el trabajo fueron los cuatro ejes considerados prioritarios para estructurar el A3P. La conclusión muestra que los ejes, iniciativas y resultados encontrados son consistentes con la filosofía y práctica que pretende A3P.A Agenda Ambiental na Administração Pública (A3P) surge como uma ferramenta essencial para a modernização da gestão pública brasileira. Este estudo teve como objetivo identificar os eixos e ações prioritários capazes de estruturar um A3P para a Secretaria Municipal de Fazenda (SEMEF) do município de Manaus. Foi realizado um estudo qualitativo, cujos respondentes foram os gestores da SEMEF, consultados a partir de roteiro de entrevista, cujos dados foram organizados em processadores de texto, analisados ​​com ferramentas de análise de conteúdo e interpretados a partir das semelhanças e diferenças nas posições dos respondentes. Os resultados mostraram que o uso racional de recursos, a gestão adequada de resíduos, a construção sustentável e a qualidade de vida no trabalho foram os quatro eixos considerados prioritários para estruturar o A3P. A conclusão mostra que os eixos, iniciativas e resultados encontrados estão de acordo com a filosofia e prática pretendida pela A3P

Direct tissue-sensing reprograms TLR4+ Tfh-like cells inflammatory profile in the joints of rheumatoid arthritis patients

Funding Information: We thank Cláudia Andrade for technical support and Juliana Gonçalves for testing samples for SARS-CoV-2 exposure. We are extremely grateful to all the participants of the study and to the whole rheumatology department at Hospital Egas Moniz that made this study possible. This work was supported by Fundação para a Ciência e Tecnologia (FCT) PTDC/MEC-REU/29520/2017, by iNOVA4Health UID/Multi/04462 and by Portuguese Society for Rheumatology (SPR) grants to H.S. H.S. is supported by FCT through IF/01722/2013 and CEECIND/01049/2020, DAS and RCT were supported by FCT through PD/BD/137409/2018 and UID/Multi/04462, respectively. Publisher Copyright: © 2021, The Author(s).CD4+ T cells mediate rheumatoid arthritis (RA) pathogenesis through both antibody-dependent and independent mechanisms. It remains unclear how synovial microenvironment impinges on CD4+ T cells pathogenic functions. Here, we identified a TLR4+ follicular helper T (Tfh) cell-like population present in the blood and expanded in synovial fluid. TLR4+ T cells possess a two-pronged pathogenic activity whereby direct TLR4+ engagement by endogenous ligands in the arthritic joint reprograms them from an IL-21 response, known to sponsor antibody production towards an IL-17 inflammatory program recognized to fuel tissue damage. Ex vivo, synovial fluid TLR4+ T cells produced IL-17, but not IL-21. Blocking TLR4 signaling with a specific inhibitor impaired IL-17 production in response to synovial fluid recognition. Mechanistically, we unveiled that T-cell HLA-DR regulates their TLR4 expression. TLR4+ T cells appear to uniquely reconcile an ability to promote systemic antibody production with a local synovial driven tissue damage program.publishersversionpublishe

SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal

Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team, IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation (https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing guidance on the implementation of the phylodynamic models; Joshua L. Cherry (National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health) for providing guidance with the subsampling strategies; and all authors, originating and submitting laboratories who have contributed genome data on GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions expressed in this article are those of the authors and do not reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government. This study is co-funded by Fundação para a Ciência e Tecnologia and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search

Peer reviewe

Searches for a heavy scalar boson H decaying to a pair of 125 GeV Higgs bosons hh or for a heavy pseudoscalar boson A decaying to Zh, in the final states with h -> tau tau

Peer reviewe

Search for a pseudoscalar boson decaying into a Z boson and the 125 GeV Higgs boson in ℓ+ℓ-bb final states

Results are reported on a search for decays of a pseudoscalar A boson into a Z boson and a light scalar h boson, where the Z boson decays into a pair of oppositely-charged electrons or muons, and the h boson decays into bb- The search is based on data from proton-proton collisions at a center-of-mass energy s=8 TeV collected with the CMS detector, corresponding to an integrated luminosity of 19.7 fb-1. The h boson is assumed to be the standard model-like Higgs boson with a mass of 125 GeV. With no evidence for signal, upper limits are obtained on the product of the production cross section and the branching fraction of the A boson in the Zh channel. Results are also interpreted in the context of two Higgs doublet models. © 2015