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Browsing by Issue Date, starting with "2018-08"

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  • Occupational exposure to cytotoxic drugs: the importance of surface cleaning to prevent or minimise exposure
    Publication . Viegas, Susana; Oliveira, Ana Cebola de; Carolino, Elisabete; Pádua, Mário
    Healthcare workers who prepare or administer cytotoxic agents run the risk of exposure, and the risks for health are real even at doses lower than those applied in cancer patients, because, in theory, no dose is safe. The most common and problematic route of exposure is through the skin, especially as work surfaces can remain contaminated even after cleaning. This pilot study aimed to demonstrate the importance of having an effective surface decontamination protocol by determining surface contamination with cyclophosphamide, 5-fluorouracil, and paclitaxel as the most common cytotoxic drugs in an oncology day service. Samples were collected before and after drug handling and analysed with high performance liquid chromatography with diode array detection (HPLC-DAD). Of the 29 samples collected before drug handling 23 were contaminated, five of which with more than one drug. Of the 30 samples collected after drug handling 25 were contaminated, eight of which with more than one drug. The two time points did not significantly differ, which evidences a widespread contamination and ineffective cleaning. This calls for revising the cleaning protocol and handling procedure to place contamination under control as much as possible.
    2018-08Journal article Open access Show more
  • Formation of intermetallic structures at the interface of steel-to-aluminium explosive welds
    Publication . Carvalho, Gustavo; Galvão, Ivan; Mendes, R.; Leal, Rui; Loureiro, A.
    The formation of intermetallic structures at the interface of carbon steel to 6082 aluminium alloy explosive welds and their influence on the weldability of these two materials were studied. The morphology, the microstructure, the chemical and phase compositions of the welds were characterised by several types of microscopy techniques. The interface characterisation proved that explosive mixtures with a lower detonation velocity were revealed as being more suitable for achieving consistent welds since jet entrapment was prevented and continuous molten layers were not formed at the weld interface. It was also found that the physical properties of the intermetallic phases generated at the weld interface have a strong influence on the weldability of steel-to-aluminium explosive welds. Specifically, it was shown that the formation of aluminium-rich intermetallic phases at the weld interface increases the solidification time of the interfacial molten material, decreasing the weldability of these two materials. The formation of these intermetallic compounds should be avoided by reducing the interaction between the flyer and the baseplate as well as by avoiding excessive molten layers.
    2018-08Journal article Restricted access Show more
  • Bactericidal efficacy of molybdenum oxide nanoparticles against antimicrobial-resistant pathogens
    Publication . Lopes, Elizeth; Piçarra, S.; Almeida, Pedro L.; Lencastre, H. de; Aires-de-Sousa, Marta
    Multidrug-resistant bacteria pose a major threat to effective antibiotics and alternatives to fight multidrug-resistant pathogens are needed. We synthetized molybdenum oxide (MoO3) nanoparticles (NP) and determined their antibacterial activity against 39 isolates: (i) eight Staphylococcus aureus, including representatives of methicillin-resistant S. aureus epidemic clones; (ii) six enterococci, including vancomycin-resistant isolates; and (iii) 25 Gram-negative isolates (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae), including extended spectrum beta-lactamases and carbapenemases producers. All isolates showed a MoO3 NP MIC of 700–800 mg l−1. MoO3 NP produced a clear inhibition zone for S. aureus and all Gram-negative isolates at concentrations ≥25 mg ml−1 and ≥50 mg ml−1 for enterococci. When the NP solutions were adjusted to pH ~7, the biocidal activity was completely abolished. MoO3 NP create an acidic pH and show a universal antimicrobial activity against susceptible and resistant isolates belonging to the most relevant bacterial species responsible for hospital-acquired infections.
    2018-08Journal article Restricted access Show more
  • Lite-CNN: a high-performance architecture to execute CNNs in low density FPGAs
    Publication . Véstias, Mário; Duarte, Rui; De Sousa, Jose; Cláudio de Campos Neto, Horácio
    Due to the computational complexity of Convolutional Neural Networks (CNNs), high performance platforms are generally considered for their execution. However, CNNs are very useful in embedded systems and its execution right next to the source of data has many advantages, like avoiding the need for data communication. In this paper, we propose an architecture for CNN inference (Lite-CNN) that can achieve high performance in low density FPGAs. Lite-CNN adopts a fixed-point representation for both neurons and weights, which was already shown to be sufficient for most CNNs. Also, with a simple and known dot product reorganization, the number of multiplications is reduced to half. We show implementation results for 8 bit fixed-point in a ZYNQ7020 and extrapolate for other larger FPGAs. Lite-CNN achieves 410 GOPs in a ZYNQ7020.
    2018-08Conference object Open access Show more
  • Parâmetros quantitativos em OCT-A na avaliação da resposta ao tratamento com anti-VEGF em doentes com neovascularização secundária à degenerescência macular relacionada com a idade
    Publication . Reis Cabral, Diogo; Rodrigues, Pedro; Pereira, Telmo; Camacho, Pedro; Vila-Franca, Marta; Coscas, Florence; Caldeira-Rosa, Paulo; Àgoas, Victor; Coscas, Gabriel
    Objetivo: Estudar a correlação entre o número de tratamentos e os parâmetros quantitativos em OCT-A da neovascularização coroideia (NVC) secundária à degenerescência macular relacionada com a idade (DMIn). Métodos: Estudo transversal após amostragem consecutiva de doentes com DMIn exsudativa (grupo 1) e indivíduos sem patologia vascular (grupo 2). Avaliação imagiológica (retinografia; OCT-B; OCT-A) e do processo clínico (número de injecções intravitreas (IIV); duração da doença). No grupo 1 foi analisada a camada retiniana externa avascular e no grupo 2 o complexo vascular superficial. As NVC foram delineadas automaticamente em Matlab. A análise quantitativa envolveu: área, densidade vascular (DV), lacunaridade e análise da dimensão fractal (DF). A análise estatística compreendeu comparação de médias e associação entre as variáveis de interesse. Resultados: Inclusão de 131 doentes (131 olhos): idade média 78.38 +/- 9.7 anos, 34% eram mulheres (comparação de médias entre grupos p >0.05). No grupo 1 o número médio de IIV foi 23.4 +/- 15 e a duração da doença média 56.8 +/- 33.3 meses. O valor médio da área vascular foi 3.6 +/-3.2 mm2; a DV 45.5 +/ 13.7%; a lacunaridade 1.95 +/- 0.6 e a DF 1.35 +/- 0.13. No grupo 2 o valor médio da DF foi 1.63 +/-0.04 (p <0.01). Verificou-se: associação entre duração da doença e: número de IIV (r=0.763, p<0.01), DF (r=0.321, p<0.01) e DV (r=-0.183, p =0.02); correlação linear moderada entre a DF e o número de IIV (r = 0.431, p < 0,01). Conclusões: A análise da dimensão fractal pode ser um biomarcador útil na avaliação quantitativa da resposta ao tratamento com fármacos intravítreos.
    2018-08Journal article Open access Show more
  • Internal dose of particles in the elderly: modeling based on aerosol measurements
    Publication . Almeida-Silva, Marina; Pilou, Marika; Housiadas, Christos; Almeida, Susana M.
    The paper presents an integrated methodology that combines experimental and modeling techniques and links exposure to airborne particulate matter (PM) with internal dose in the respiratory system and burden in adjacent tissues over a period of time. The methodology is used to estimate doses in the respiratory systems of elders that reside in 10 elderly care centers (ECCs) in the metropolitan area of Lisbon. Measurements of PM were performed in the ECCs and combined with a time-budget survey for the occupants. This information served as input to the first model that estimated particle doses in the different regions of the respiratory tract of the elderly, and then a second model was used to calculate particle build-up in the alveolar region, the interstitium and the hilar lymph nodes of the elders over a 5-year exposure period. It was found that in 5 years of continuous exposure to the average particle concentration measured over all ECCs, 258 mg of all particles are deposited on the surface of the alveoli of which 79.6% are cleared, 18.8% are retained in the alveolar region, 1.5% translocate to the hilar lymph nodes, and 0.1% are transferred to the interstitium.
    2018-08Journal article Open access Show more
  • Light-emitting diodes aided indoor localization using visible light communication technology
    Publication . Vieira, Manuela; Vieira, Manuel; Louro, Paula; Vieira, Pedro
    This paper focuses on designing and analyzing a visible light-based communication and positioning system for indoor wireless communication under light-emitting diodes (LEDs) lighting environments. The indoor positioning system uses trichromatic white LEDs, both for illumination purposes and as transmitters, and an optical processor, based on a-SiC:H technology, as a mobile receiver. An on–off keying modulation scheme is used, proving a good trade-off between system performance and implementation complexity. The relationship between the transmitted data and the received output levels is decoded. LED bulbs work as transmitters, sending information together with different identifiers, IDs, related to their physical locations. Square and diamond topologies for the unit cell are analyzed, and a two-dimensional localization design, demonstrated by a prototype implementation, is presented. Fine-grained indoor localization is tested. The received signal is used in coded multiplexing techniques for supporting communications and navigation concomitantly on the same channel. The location and motion information are found by mapping the position and estimating the location areas.
    2018-08Journal article Restricted access Show more
  • A pobreza da cultura na época da sua descentralização
    Publication . Matoso, Rui
    Com a aprovação da Lei-quadro da transferência de competências para as autarquias locais e para as entidades intermunicipais (Lei n.º 50/2018 de 16 de agosto), que visa concretizar os princípios da subsidiariedade, da descentralização administrativa e da autonomia do poder local, a dimensão cultural fica reduzida a umas míseras quatro alíneas do Artº 15, e praticamente despida de qualquer sentido democrático e da sua importância vital para os territórios.
    2018-08Journal article Open access Show more
  • Programa de iniciação no ensino do contrabaixo, no 1.º ciclo do ensino básico: orientações e metas
    Publication . Costa, Carlos Miguel Amorim da; Rêgo, Manuel Luís
    Resumo I - O presente trabalho relata o Estágio do Ensino Especializado realizado no ano letivo 2017/2018 na Escola Artística de Música do Conservatório Nacional e na Escola Básica Luís António Verney. Nele é possível encontrar as várias informações acerca do decorrer deste estágio. Sendo que este relatório está dividido em duas partes, a primeira apresenta todos os conteúdos referentes à Prática Pedagógica expostos em sete capítulos, e a segunda expõe o trabalho de investigação cientifica. A organização da primeira secção está estruturada da seguinte forma: introdução, âmbito e objetivos, caracterização das escolas, práticas pedagógicas desenvolvidas, programa de estudos e descrição da prática pedagógica e por último a reflexão sobre a prática pedagógica. Assim, esta parte é uma compilação das informações obtidas por mim ao longo deste ano letivo, informações que provém quer dos Projetos Educativos, professores cooperantes e experiências pessoais.
    2018-08Master thesis Restricted access Show more
  • Curricula, attributes and clinical experiences of radiography programs in four European educational institutions
    Publication . Reis, Cláudia; Jorge, José; York, H.; Flaction, L.; Johansen, S.; Maehle, S.
    Introduction - The aim of this study was to compare radiography curricula, teaching/learning strategies, skill development, clinical practice outcomes and research development delivered by four European educational institutions. Methods - This study was carried out in two phases: the first focused on curricula analysis; the second involved online questionnaires to ascertain data from two key-informants: students who had recently completed their bachelor thesis and teaching staff. Questionnaires were designed to capture teaching and learning strategies, skill acquisition and outcomes of clinical practice and research. Descriptive statistics and thematic analysis were performed according to the nature of the questions. Results - The European Credits Transfer System dedicated per core subject area (natural sciences, clinical practice, research, imaging technology, humanities) differed between institutions. Students classified technical, practical and communication skills as the most important, teaching-staff highlighted also critical thinking. The students defined as “very good” their experience in radiography (58.5%) and computed-tomography (45%). Magnetic resonance imaging practice was considered “Average” by 53% of the UK-students and “Good” by the other European students (40%). According to 71% (55/78) of the students, research work contributed to the development of critical/reflective thinking. Conclusions - The four radiography programs presented variations in curricula, contact-hours, clinical experience, and outcomes. Research units allowed the participant-students to develop their critical thinking capabilities. The outcomes from clinical practice differ across the institutions, mainly due to differences in background and access to specialties. Further work is necessary to assess the real impact of different radiography programs on professional and academic mobility across Europe.
    2018-08Journal article Restricted access Show more