335 research outputs found

    Paediatric visceral leishmaniasis: experience of a paediatric referral center 1990-2009

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    INTRODUCTION: Visceral Leishmaniasis (VL) is a systemic infection, endemic in many parts of the world, including Portugal. The aim is to review all cases of VL admitted to our hospital. PATIENTS AND METHODS: Retrospective analysis of all cases of VL admitted to a Level III Paediatric Hospital, between January 1990 and December 2009 (20 years). Demographic, epidemiological, clinical, laboratorial, therapeutic and follow-up data were analysed. RESULTS: During the study period, 54 children were admitted with VL, three of which were excluded from the study due to incomplete clinical records. The mean age was 27 months (seven months - twelve years) and 53% were female. Two thirds of the cases were diagnosed during Spring and Summer. The mean time for diagnosis was 31 days (2-188 days). The most common clinical findings were splenomegaly (100%), fever (96%), pallor (90%) and hepatomegaly (82%). Bone marrow aspiration was performed in all children, with amastigotes identified in 73% of the cases. Indirect immunofluorescence was performed in 30 cases, being positive in 29 (97%). All were treated with meglumine antimoniate. Three children relapsed during the first year after the initial episode. A 17 months-old child died due to cardiac failure. CONCLUSIONS: The early diagnosis of VL is essential to carry out prompt management and prevent potential fatal complications. In our analysis, the management with meglumine antimoniate resulted in an overall favourable outcom

    Polylactic acid/carbon nanoparticle composite filaments for sensing

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    Polylactic acid (PLA) is a bio-based, biodegradable polymer that presents high potential for biomedical and sensing applications. Ongoing works reported in the literature concern mainly applications based on 3D printing, while textile applications are hindered by the limited flexibility of PLA and its composite filaments. In the present work, PLA/multiwall carbon nanotube (MWCNT) composite filaments were produced with enhanced flexibility and electrical conductivity, which may be applied on a textile structure. A biodegradable plasticizer was incorporated in the nanocomposites, aiming at improving MWCNT dispersion and increasing the flexibility of the filaments. Filaments were produced with a range of compositions and their morphology was characterized as well as their thermal, thermomechanical, and electrical properties. Selected compositions were tested for sensing activity using saturated acetone vapor, demonstrating a suitable response and potential for the application in fabrics with sensing capacity.This research was funded by FEDER/FEEI through FCT, National Funds Reference UID/CTM/50025/2019 and UID/CTM/00264/2019 and the Project TSSIPRO-Technologies for Sustainable and Smart Innovative Products, NORTE-01-0145-FEDER-000015, supported by Programa Operacional Regional do Norte Funding

    Tourism sector competitiveness in Portugal: applying Porter's Diamond

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    The tourism sector has stood out for its enormous capacity for growth on a global scale and holding a relevant role both as a tool for the competitiveness and as a driver of regional development. This profile stems not only from its multiplier effects but also the opportunities susceptible to identification within the scope of offsetting regional disparities in growth and prosperity. The objective of this research project consists of evaluating the competitiveness of the regional areas and directorates of tourism in Portugal with the methodology applied requiring the input of primary data (a sample of 446 companies), through a questionnaire aimed at companies displaying the activities characteristic of the World Tourism Organisation satellite account. Through the application of Porter’s Diamond Model, we arrived at a conceptual model through recourse to the Partial Least Square – Path Modelling technique with the objective of analysing the relationships unfolding among the determinant variables to competitiveness in the tourism sector. Despite the results returned proving clear, we also verify that encapsulating competitiveness proves no easy task given how Portugal reports regions with simultaneously very varied and very specific characteristics.O sector do turismo destaca-se pela enorme capacidade de crescimento a nível mundial, desempenhando um papel relevante tanto como ferramenta para a competitividade como enquanto motor do desenvolvimento regional. Este perfil decorre não apenas dos seus efeitos multiplicadores, mas também das oportunidades suscetíveis de identificação no âmbito da compensação das disparidades regionais no crescimento e prosperidade. O objetivo desta investigação consiste em avaliar a competitividade das áreas regionais e direções do turismo em Portugal. Utilizamos dados primários (uma amostra de 446 empresas), através de um questionário destinado a empresas que exibem as atividades características da conta satélite da Organização Mundial de Turismo. Através da aplicação do Modelo de Diamante de Porter, alcançamos um modelo conceitual através do recurso à técnica de Partial Least Square – Path Modelling com o objetivo de analisar as relações que se desdobram entre as variáveis determinantes para a competitividade no setor de turismo. Apesar de os resultados retornados serem claros, verificamos também que o encapsulamento da competitividade não se revela uma tarefa fácil, dado o fato de Portugal englobar regiões com características simultaneamente muito variadas e muito específicas

    Artificial Intelligence Decision Support System Based on Artificial Neural Networks to Predict the Commercialization Time by the Evolution of Peach Quality

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    Climacteric fruit such as peaches are stored in cold chambers after harvest and usually are maintained there until the desired ripening is reached to direct these fruit to market. Producers, food industries and or traders have difficulties in defining the period when fruit are at the highest level of quality desired by consumers in terms of the physical‐chemical parameters (hardness –H–, soluble solids content –SSC–, and acidity –Ac–). The evolution of peach quality in terms of these parameters depends directly on storage temperature –T– and relative humidity –RH–, as well on the storage duration –t–. This paper describes an Artificial Intelligence (AI) Decision Support Sys‐ tem (DSS) designed to predict the evolution of the quality of peaches, namely the storage time re‐ quired before commercialization as well as the late commercialization time. The peaches quality is stated in terms of the values of SSC, H and Ac that consumers most like for the storage T and RH. An Artificial neuronal network (ANN) is proposed to provide this prediction. The training and val‐ idation of the ANN were conducted with experimental data acquired in three different farmers’ cold storage facilities. A user interface was developed to provide an expedited and simple predic‐ tion of the marketable time of peaches, considering the storage temperature, relative humidity, and initial physical and chemical parameters. This AI DSS may help the vegetable sector (logistics and retailers), especially smaller neighborhood grocery stores, define the marketable period of fruit. It will contribute with advantages and benefits for all parties—producers, traders, retailers, and con‐ sumers—by being able to provide fruit at the highest quality and reducing waste in the process. In this sense, the ANN DSS proposed in this study contributes to new AI‐based solutions for smart cities.This study is within the activities of project PrunusPós—Otimização de processos de ar‐ mazenamento, conservação em frio, embalamento ativo e/ou inteligente, e rastreabilidade da qual‐ idade alimentar no póscolheita de produtos frutícolas (Optimization of processes of storage, cold conservation, active and/or intelligent packaging, and traceability of food quality in the postharvest of fruit products), Operation n.º PDR2020‐101‐031695 (Partner), Consortium n.º 87, Initiative n.º 175 promoted by PDR2020 and co‐financed by FEADER under the Portugal 2020 initiative.info:eu-repo/semantics/publishedVersio

    Surface degradation of glass ceramics after exposure to acidulated phosphate fluoride

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    OBJECTIVE: This study evaluated the surface degradation effect of acidulated phosphate fluoride (APF) gel exposure on the glassy matrix ceramics as a function of time. MATERIAL AND METHODS: Disc-shaped ceramic specimens (N = 120, 10/per ceramic material) were prepared in stainless steel molds (inner diameter: 5 mm, height: 2 mm) using 6 dental ceramics: 3 indicated for ceramic-fused-to-metal (Vita Omega 900, Carmen and Vita Titankeramik), 2 for all-ceramic (Vitadur Alpha and Finesse® Low Fusing) and 1 for both types of restorations (IPS d.SIGN). The specimens were wet ground finished, ultrasonically cleaned and auto-glazed. All specimens were subjected to calculation of percentage of mass loss, surface roughness analysis and topographical description by scanning electron microscopy (SEM) before (0 min) and after exposure to 1.23 % APF gel for 4 min and 60 min representing short- and long-term etching effect, respectively. The data were analyzed using two-way ANOVA with repeated measures and Tukey's test (a=0.05). RESULTS: Significant effect of the type of the ceramics (p=0.0000, p=0.0031) and exposure time (p=0.0000) was observed in both surface roughness and percentage of mass loss values, respectively. The interaction factor between both parameters was also significant for both parameters (p=0.0904, p=0.0258). Both 4 min (0.44±0.1 - 0.81±0.2 mm) and 60 min (0.66±0.1 - 1.04±0.3 mm) APF gel exposure created significantly more surface roughness for all groups when compared to the control groups (0.33±0.2 - 0.68±0.2 mm) (p;0.05) but at 60 min exposure, IPS d.SIGN showed the highest percentage of mass loss (0.1151±0.11). The mean surface roughness for Vita Titankeramik (0.84±0.2 mm) and Finesse® Low Fusing (0.74.±0.2 mm) was significantly higher than those of the other ceramics (0.59±0.1 mm - 0.49±0.1 mm) and Vita Titankeramik (

    Transferência de tecnologias, comunicação e negócios na Embrapa Gado de Leite: março de 2004 a maio de 2008.

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    Liquefaction Characteristics of Sand as Studied by Cyclic Torsional Testing Using Hollow Cylinder Apparatus

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    The DNA recombination and repair machineries of Mycoplasma genitalium and Mycoplasma pneumoniae differ considerably from those of gram-positive and gram-negative bacteria. Most notably, M. pneumoniae is unable to express a functional RecU Holliday junction (HJ) resolvase. In addition, the RuvB homologues from both M. pneumoniae and M. genitalium only exhibit DNA helicase activity but not HJ branch migration activity in vitro. To identify a putative role of the RuvA homologues of these mycoplasmas in DNA recombination, both proteins (RuvA(Mpn) and RuvA(Mge), respectively) were studied for their ability to bind DNA and to interact with RuvB and RecU. In spite of a high level of sequence conservation between RuvA(Mpn) and RuvA(Mge) (68.8% identity), substantial differences were found between these proteins in their activities. First, RuvA(Mge) was found to preferentially bind to HJs, whereas RuvA(Mpn) displayed similar affinities for both HJs and single-stranded DNA. Second, while RuvA(Mpn) is able to form two distinct complexes with HJs, RuvA(Mge) only produced a single HJ complex. Third, RuvA(Mge) stimulated the DNA helicase and ATPase activities of RuvB(Mge), whereas RuvA(Mpn) did not augment RuvB activity. Finally, while both RuvA(Mge) and RecU(Mge) efficiently bind to HJs, they did not compete with each other for HJ binding, but formed stable complexes with HJs over a wide protein concentration range. This interaction, however, resulted in inhibition of the HJ resolution activity of RecU(Mge)

    Production of cellulose nanofibers from Alfa grass and application as reinforcement for polyvinyl alcohol

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    The work reported demonstrates an simple method of extracting cellulose nanofibers (CNF) from cellulose microfibers (CMF) obtained from the plant Stipatenacissima. Here, a method for the production of CNF from CMF extracted from Alfa grass by exfoliation in polyvinyl alcohol (PVA) solution, is demonstrated. The CMF were produced in powder form and exfoliated in PVA aqueous solution to produce composites with 2, 4, 5 and 10 wt-% of CNF. Scanning Electron Microscopy demonstrated exfoliation of CMF, dispersion of the CNF and wetting by the polymer. The composites were characterised by thermogravimetry, differential scanning calorimetry, X-ray diffraction and tensile testing. The addition of CNF to PVA reduced the crystallinity degree of PVA. The large increase of the Young’s modulus from 38 to 113% (relative to pure PVA) for composites with 2 to 10 wt-% of CNF incorporation is consistent with the extensive exfoliation of CMF into CNF and its excellent interface with PVA.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for project PEst-C/CTM/ LA0025/2013 (Strategic Project - LA 25 - 2013–2014). Salma Ben Cheikh acknowledges the Ministry of Higher Education and Scientific Research (Tunisia) for a grant to travel to IPC/i3N in Portugal

    Impactos da substituição de importações de produtos agrícolas e agroindustriais na economia brasileira

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    Due to its natural resources, the Brazilian economy has been able, at the same time, to provide the needs of the internal market of agricultural an agroindustrial products as well as of playing a major role in the international market for some agricultural and agroindustrial products. However, it can be observed a negative surplus in the trade balance of some agricultural products. This paper evaluates the impacts that a supposed process of import substitution of agricultural and agroindustrials products would have in the Brazilian economy. To do so, it is made use of the input-output theory, where the imports of the above products are now being considered as domestic products. In this procedure, it was implicitly assumed that there would be some kind of compensatory policy to allow for the domestic sectors to supply the imported products at the same price level as in the international market and that there would not be retaliations in the international market. The impacts are measured by applying different kinds approaches, e.g., multipliers, forward and backward linkages, and field-of-influence, to the observed and modified input-output systems. The results show gains for the economy as a whole, without significant changes in the productive structure. The Textile sector would be the one to respond more positively to the policy being proposed here
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