53 research outputs found

    Formulation and characterization of potential composites filaments from PLA and tobacco stems for application in additive manufacturing

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    A tecnologia de fabricação por filamento fundido (FFF) utilizando polímeros como PLA e ABS é bem conhecida. Contudo, o desenvolvimento de filamentos compósitos para esta tecnologia de manufatura aditiva, bem como a determinação dos parâmetros de processamento e das propriedades resultantes na extrusão e na impressão 3D, ainda requerem pesquisa. Esse estudo exploratório analisa as propriedades químicas, térmicas e a morfologia de filamento de matriz polimérica de PLA e talos de tabaco, visando sua utilização no processo FFF. Os materiais utilizados foram talos de tabaco moídos e PLA. As partículas de tabaco, com tamanho médio de 50 m, apresentaram-se aleatoriamente distribuídas no filamento. No entanto, aglomerados de partículas, bolhas e porosidades foram observados no centro do filamento. Ensaios por espectroscopia no infravermelho por transformada de Fourier mostraram que o filamento compósito apresentou interação mecânica entre os materiais. A análise térmica permitiu verificar que não houve degradação do pó de talos de tabaco, mantendo a integridade química e física do filamento compósito a temperatura de extrusão de 180 °C. A calorimetria exploratória diferencial revelou que as partículas de pó de talos de tabaco podem ter atuado como agente nucleante, aumentando o grau de cristalinidade do filamento compósito. Sugere-se para estudos futuros o aumento do percentual de pó de talos de tabaco, a investigação de outros métodos de preparação de compósitos, bem como um estudo da adição de plastificantes ou agentes compatibilizantes para aprimorar a ligação entre a interface do PLA e as partículas de tabaco.Fused filament fabrication (FFF) using polymers such as PLA and ABS are well known. However, the development of composite filaments for this type of additive manufacturing technology, as well as the study of processing parameters and properties resulting from extrusion process and printing still require investigation. This exploratory research aims to analyze chemical and thermal properties and the morphology of a composite filament from PLA polymer matrix and tobacco stems to seek its use in the FFF process. The materials used were waste of tobacco stems powder and PLA. Tobacco particles, with an average size of 50 m, have distribution on the filament. However, clusters of particles, bubbles and porosities were observed in the center of the filament. Fourier Transform Infrared analyses showed that the composite filament presented mechanical interaction between the materials. Thermal analyses allowed to verify that there was no degradation of tobacco stem powder. Therefore, chemical and physical integrity of the composite filament was kept at an extrusion temperature of 180 °C. Differential scanning calorimetry revealed that micronized particles of tobacco stems may have acted as nucleating agents for crystallization, increasing the crystallinity degree of the composite filament. It is recommended for future studies to increase the percentage of tobacco stems powder, the investigation of other methods for composites preparation, as well as a study of the addition of plasticizers or coupling agents to improve the interface between PLA and tobacco particles

    Formulação e caracterização de potenciais filamentos compósitos de PLA e talos de tabaco para aplicação em manufatura aditiva

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    A tecnologia de fabricação por filamento fundido (FFF) utilizando polímeros como PLA e ABS é bem conhecida. Contudo, o desenvolvimento de filamentos compósitos para esta tecnologia de manufatura aditiva, bem como a determinação dos parâmetros de processamento e das propriedades resultantes na extrusão e na impressão 3D, ainda requerem pesquisa. Esse estudo exploratório analisa as propriedades químicas, térmicas e a morfologia de filamento de matriz polimérica de PLA e talos de tabaco, visando sua utilização no processo FFF. Os materiais utilizados foram talos de tabaco moídos e PLA. As partículas de tabaco, com tamanho médio de 50 m, apresentaram-se aleatoriamente distribuídas no filamento. No entanto, aglomerados de partículas,  bolhas e porosidades foram observados no centro do filamento. Ensaios por espectroscopia no infravermelho por transformada de Fourier mostraram que o filamento compósito apresentou interação mecânica entre os materiais. A análise térmica permitiu verificar que não houve degradação do pó de talos de tabaco, mantendo a integridade química e física do filamento compósito a temperatura de extrusão de 180 °C. A calorimetria exploratória diferencial revelou que as partículas de pó de talos de tabaco podem ter atuado como agente nucleante, aumentando o grau de cristalinidade do filamento compósito. Sugere-se para estudos futuros o aumento do percentual de pó de talos de tabaco, a investigação de outros métodos de preparação de compósitos, bem como um estudo da adição de plastificantes ou agentes compatibilizantes para aprimorar a ligação entre a interface do PLA e as partículas de tabaco.Palavras-chave: impressão 3D, fabricação de filamento fundido, manufatura aditiva, compósitos, tabaco.

    Yicathins B and C and analogues: total synthesis, lipophilicity and biological activities

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    Natural products had always be an important source of new hits and leads in drug discovery. The marine environment has been regarded as a significant souce of novel and exquisite bioactive compounds. Yicathins B and C are two marine derived xanthones that have shown antibacterial and antifungal activities. Herein, the total synthesis of these yicathins is reported for the first time as well as six novel analogues. As marine natural products tend to bear very lipophilic scaffolds, the lipophilicity of yicathins and its analogues was evaluated using the classical octanol:water system and a biomimetic model based system. As the xanthonic nucleus is a â privileged structureâ , other biological activities were evaluated, namely antitumor and anti-inflammatory activities. An interesting anti-inflammatory activity was identified for yicathins analogues that paves the way for the design of dual activity (anti-infective and anti-inflammatory) marine inspired xanthones derivatives.This work was supported through national funds provided by FCT/MCTES - Foundation for Science and Technology from the Minister of Science, Technology and Higher Education (PIDDAC) and European Regional Development Fund (ERDF) through the COMPETE - Programa Operacional Factores de Competitividade (POFC) programme, under the projects PTDC/MAR-BIO/4694/2014 (reference POCI-01-0145-FEDER-016790; Project 3599 - Promover a ProducAo Cientifica e Desenvolvimento Tecnologico e a ConstituicAo de Redes Tematicas (3599-PPCDT)) and PTDC/SAU-PUB/28736/2017 (reference POCI-01-0145-FEDER- 028736) in the framework of the programme PT2020. D. R. P. L. is grateful for research grant PTDC/MAR-BIO/4694/2014-BI-2017-003. J. X. S. thanks the FCT PhD Programmes and Programa Operacional Capital Humano (POCH), specifically the BiotechHealth Programme (Doctoral Programme on Cellular and Molecular Biotechnology Applied to Health Sciences), reference PD/00016/2012; through the FCT and POCH for PhD grants (SFRH/BD/98105/2013 and SFRH/BD/116167/2016). The authors would like to thank Sara Cravo and Gisela Adriano for the technical support, the Centro de Apoio Cientifico e Tecnoloxico a Investigation (C.A.C.T.I., University of Vigo, Pontevedra, Spain) for HRMS analysis, the Centro de Materiais da Universidade do Porto (CEMUP, Porto, Portugal) for HRMS, and the Departamento de Quimica da Universidade de Aveiro (Portuguese NMR network) for the NMR analysis

    Materialidades epistemológicas: Fundamentos e representações da pesquisa arquitetónica

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    ISCTE, Programa de Doutoramento em Arquitetura dos Territórios Metropolitanos Contemporâneos, DINÂMIA'CET-Iscte, Linha Temática "Representação e Discurso na Arquitetura e no Território"A compilação de textos em torno do tema: Materialidades Epistemológicas - Fundamentos e Representações da Pesquisa Arquitetónica, resulta de um trabalho realizado no âmbito da linha temática: “Representação e Discurso na Arquitetura e no Território”, do programa de doutoramento em Arquitetura dos Territórios Metropolitanos Contemporâneos. Os doutorandos, todos eles em processo de desenvolvimento de tese, foram envolvidos num debate transversal, onde se procuraram nexos e ligação entre as várias investigações em curso. Este processo partilhado convergiu na definicão temática e conceptual da materialidade arquitetónica, como agente unificador de diversos temas de investigação. O processo potenciou a definição de um itinerário científico, que se foi autonomizando através de diferentes leituras dos processos de investigação, com foco no tema da materialidade. Os resultados foram fixados num conjunto de textos sequenciais que propõem enquadramentos temáticos e críticos sobre a base do pensamento arquitetónico, colocando a matéria como alicerce desse mesmo pensamento e como representação da pesquisa em arquitetura

    A prediction rule to stratify mortality risk of patients with pulmonary tuberculosis

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    Tuberculosis imposes high human and economic tolls, including in Europe. This study was conducted to develop a severity assessment tool for stratifying mortality risk in pulmonary tuberculosis (PTB) patients. A derivation cohort of 681 PTB cases was retrospectively reviewed to generate a model based on multiple logistic regression analysis of prognostic variables with 6-month mortality as the outcome measure. A clinical scoring system was developed and tested against a validation cohort of 103 patients. Five risk features were selected for the prediction model: hypoxemic respiratory failure (OR 4.7, 95% CI 2.8-7.9), age >= 50 years (OR 2.9, 95% CI 1.7-4.8), bilateral lung involvement (OR 2.5, 95% CI 1.44.4), >= 1 significant comorbidity-HIV infection, diabetes mellitus, liver failure or cirrhosis, congestive heart failure and chronic respiratory disease-(OR 2.3, 95% CI 1.3-3.8), and hemoglobin = 6) mortality risk. The mortality associated with each group was 2.9%, 22.9% and 53.9%, respectively. The model performed equally well in the validation cohort. We provide a new, easy-to-use clinical scoring system to identify PTB patients with high-mortality risk in settings with good healthcare access, helping clinicians to decide which patients are in need of closer medical care during treatment.This work was supported by Fundacao Amelia de Mello/Jose de Mello Saude and Sociedade Portuguesa de Pneumologia (SPP). This work was developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). NSO is a FCT (Fundacao para a Ciencia e Tecnologia) investigator. MS is an Associate FCT Investigator. The fundershad no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Identification of clusters of asthma control: A preliminary analysis of the inspirers studies

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    This work was funded by ERDF (European Regional Development Fund) through the operations: POCI- -01-0145-FEDER-029130 (“mINSPIRERS—mHealth to measure and improve adherence to medication in chronic obstructive respiratory diseases - generalisation and evaluation of gamification, peer support and advanced image processing technologies”) co-funded by the COMPETE2020 (Programa Operacional Competitividade e Internacionalização), Portugal 2020 and by Portuguese Funds through FCT (Fundação para a Ciência e a Tecnologia).© 2020, Sociedade Portuguesa de Alergologia e Imunologia Clinica. All rights reserved. Aims: To identify distinct asthma control clusters based on Control of Allergic Rhinitis and Asthma Test (CARAT) and to compare patients’ characteristics among these clusters. Methods: Adults and adolescents (≥13 years) with persistent asthma were recruited at 29 Portuguese hospital outpatient clinics, in the context of two observational studies of the INSPIRERS project. Demographic and clinical characteristics, adherence to inhaled medication, beliefs about inhaled medication, anxiety and depression, quality of life, and asthma control (CARAT, >24 good control) were collected. Hierarchical cluster analysis was performed using CARAT total score (CARAT-T). Results: 410 patients (68% adults), with a median (percentile 25–percentile 75) age of 28 (16-46) years, were analysed. Three clusters were identified [mean CARAT-T (min-max)]: cluster 1 [27(24-30)], cluster 2 [19(14-23)] and cluster 3 [10(2-13)]. Patients in cluster 1 (34%) were characterised by better asthma control, better quality of life, higher inhaler adherence and use of a single inhaler. Patients in clusters 2 (50%) and 3 (16%) had uncontrolled asthma, lower inhaler adherence, more symptoms of anxiety and depression and more than half had at least one exacerbation in the previous year. Further-more, patients in cluster 3 were predominantly female, had more unscheduled medical visits and more anxiety symp-toms, perceived a higher necessity of their prescribed inhalers but also higher levels of concern about taking these inhalers. There were no differences in age, body mass index, lung function, smoking status, hospital admissions or specialist physician follow-up time among the three clusters. Conclusion: An unsupervised method based on CARAT--T, identified 3 clusters of patients with distinct, clinically meaningful characteristics. The cluster with better asthma control had a cut-off similar to the established in the validation study of CARAT and an additional cut-off seems to distinguish more severe disease. Further research is necessary to validate the asthma control clusters identified.publishersversionpublishe

    MAMMALS IN PORTUGAL : A data set of terrestrial, volant, and marine mammal occurrences in P ortugal

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    Mammals are threatened worldwide, with 26% of all species being includedin the IUCN threatened categories. This overall pattern is primarily associatedwith habitat loss or degradation, and human persecution for terrestrial mam-mals, and pollution, open net fishing, climate change, and prey depletion formarine mammals. Mammals play a key role in maintaining ecosystems func-tionality and resilience, and therefore information on their distribution is cru-cial to delineate and support conservation actions. MAMMALS INPORTUGAL is a publicly available data set compiling unpublishedgeoreferenced occurrence records of 92 terrestrial, volant, and marine mam-mals in mainland Portugal and archipelagos of the Azores and Madeira thatincludes 105,026 data entries between 1873 and 2021 (72% of the data occur-ring in 2000 and 2021). The methods used to collect the data were: live obser-vations/captures (43%), sign surveys (35%), camera trapping (16%),bioacoustics surveys (4%) and radiotracking, and inquiries that represent lessthan 1% of the records. The data set includes 13 types of records: (1) burrowsjsoil moundsjtunnel, (2) capture, (3) colony, (4) dead animaljhairjskullsjjaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8),observation in shelters, (9) photo trappingjvideo, (10) predators dietjpelletsjpine cones/nuts, (11) scatjtrackjditch, (12) telemetry and (13) vocalizationjecholocation. The spatial uncertainty of most records ranges between 0 and100 m (76%). Rodentia (n=31,573) has the highest number of records followedby Chiroptera (n=18,857), Carnivora (n=18,594), Lagomorpha (n=17,496),Cetartiodactyla (n=11,568) and Eulipotyphla (n=7008). The data setincludes records of species classified by the IUCN as threatened(e.g.,Oryctolagus cuniculus[n=12,159],Monachus monachus[n=1,512],andLynx pardinus[n=197]). We believe that this data set may stimulate thepublication of other European countries data sets that would certainly contrib-ute to ecology and conservation-related research, and therefore assisting onthe development of more accurate and tailored conservation managementstrategies for each species. There are no copyright restrictions; please cite thisdata paper when the data are used in publications.info:eu-repo/semantics/publishedVersio

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

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    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
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