42 research outputs found

    Monitorização da qualidade do ar na envolvente de indústrias cimenteiras: Caso de estudo da fábrica SECIL-Outão

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    Dissertação Apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, perfil de Gestão e Sistemas AmbientaisA monitorização da qualidade do ar revela-se fundamental na gestão do recurso ar. Este trabalho teve como objectivo avaliar a resposta de uma rede de monitorização de qualidade do ar (RMQA) às emissões atmosféricas geradas por uma fonte de poluição pontual próxima, recorrendo a técnicas estatísticas de tratamento de dados. O caso de estudo foi a cimenteira SECIL-Outão e respectiva RMQA, que se insere numa região complexa em termos orográficos e meteorológicos. A avaliação foi realizada com base nos registos de Maio de 2006 a Maio de 2007, das emissões e concentrações dos poluentes SO2, NOx e PM10. Foram realizadas análises de correlação entre as estações da RMQA e entre estas e as emissões da fábrica SECIL-Outão e da Central Termoeléctrica de Setúbal (CTS). Os resultados apontam para a existência de correlações elevadas entre as estações para o poluente partículas PM10, sendo tal provavelmente resultado da poluição de fundo. Não se verificou qualquer correlação entre as emissões daquelas duas fontes pontuais e as estações. Foram realizadas análises de variância a um-factor (ANOVA), verificando-se que nenhuma das estações de monitorização está a detectar o efeito das emissões da fábrica SECIL-Outão. Apenas as estações Tróia e S. Filipe detectam,com 95% de confiança, o NOx emitido pela CTS

    Analysis and diagnosis of a hand tools production system

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    All rights reserved. Engineers must have a set of professional competences, which includes sound technical knowledge and the ability to solve engineering problems, integrated with a set of transversal competences, which must mobilized for managing projects, working in teams and communicate with the others effectively. The development of these sets of competences can be supported by projects in interaction with companies. This article reports the work developed by a group of students on the Integrated Project of the 4 th year of Industrial Engineering and Management of the University of Minho. The main objective of this work is to describe the type of project that a group of students can develop in interaction with an industrial company, and reflect about the main results that this project have for the development of their competences and for the company. This is a descriptive paper based upon on reports and the experience of the students. The target of the project was the diagnosis and analysis of a production system in an industrial environment. The company chosen to develop this project is a multinational and pioneer company on the manufacturing of hand tools. The content of this article will mainly cover the internal supplier of materials (Mizusumashi), namely the standardization of the Mizusumashi route and the improvement of the components` warehouse (materials organization and visual management). The suggested modifications can result in a 30% decrease of the time wasted in the warehouse, a 20% decrease of the time it takes the Mizusumashi to complete a full route, reaching the 45 minutes the company requested. The students were able to fulfil the project milestones and integrate the company culture in their weekly visits, during the 15 weeks of the project. Furthermore, the company showed to be very satisfied with their behaviour and performance.(undefined)info:eu-repo/semantics/publishedVersio

    Late results (>10 years) of intracoronary beta brachytherapy for diffuse in-stent restenosis

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    Introduction Until the development of drug-eluting stents (DES), diffuse in-stent restenosis (ISR) was the main limitation of bare-metal stents in percutaneous coronary intervention (PCI). Among the different treatments available, intracoronary brachytherapy (BT) emerged as one of the most promising, although it was almost abandoned with the increasing use of DES. Objective To assess the Portuguese experience with 90Sr/90Y beta brachytherapy for the treatment of diffuse ISR regarding long-term (>10 years) major adverse cardiac events (MACE) and angiographic restenosis. Methods This single-center, retrospective, observational study included 12 consecutive patients treated between January and June 2001, mean age 58.6±9.9 years (range 43-77 years), 11 male. All had chronic stable angina, 75% had dyslipidemia, 58% had hypertension, 50% had peripheral arterial disease, 42% had diabetes and 50% had multivessel disease. Recurrent ISR was present in half of the patients and 11 had normal left ventricular function. After balloon dilatation, BT was performed using an Sr90/Y90 (Novoste Beta-CathTM) beta radiation source. All patients remained under dual antiplatelet therapy until scheduled nine-month follow-up angiography. Patients were followed for the occurrence of death (all-cause and cardiovascular), non-fatal myocardial infarction (MI), revascularization, stent thrombosis and angiographic restenosis. MACE were defined as the combined incidence of cardiac death, MI and urgent target vessel revascularization. Results In all cases there was both clinical and angiographic success. In a mean follow-up of 10.9±2.5 years, 19 events occurred in seven patients: death in three (25%), only one cardiac (8.3%); ST-elevation MI in one (related to a non-target vessel) (8.3%); and 15 revascularizations in five (42%), of which nine were of the target vessel (mainly in the first two years). There was only one case of probable stent thrombosis. Angiographic restenosis at nine months was 27% (three out of 11 patients), of which two were total occlusions. Ten-year MACE-free survival was 42% (5 patients). Conclusions Intracoronary beta brachytherapy for the treatment of diffuse ISR in this small cohort of patients proved to be safe and efficacious, with no late adverse events related to intracoronary radiation.publishersversionpublishe

    On the nature of the (de)coupling of the magnetostructural transition in Er5_5Si4_4

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    In this report, a successful thermodynamical model was employed to understand the structural transition in Er5_5Si4_4, able to explain the decoupling of the magnetic and structural transition. This was achieved by the DFT calculations which were used to determine the energy differences at 0 K, using a LSDA+U approximation. It was found that the M structure as the stable phase at low temperatures as verified experimentally with a ΔF0=\Delta F_0 = -0.262 eV. Finally, it was achieved a variation of Seebeck coefficient (\sim 6 μ\muV) at the structural transition which allow to conclude that the electronic entropy variation is negligible in the transition.Comment: 17 pages, 3 figures, 1 tabl

    A practical clinical score

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    Copyright © 2022 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.INTRODUCTION AND OBJECTIVES: Obstructive coronary artery disease (CAD) remains the most common etiology of heart failure with reduced ejection fraction (HFrEF). However, there is controversy whether invasive coronary angiography (ICA) should be used initially to exclude CAD in patients presenting with new-onset HFrEF of unknown etiology. Our study aimed to develop a clinical score to quantify the risk of obstructive CAD in these patients. METHODS: We performed a cross-sectional observational study of 452 consecutive patients presenting with new-onset HFrEF of unknown etiology undergoing elective ICA in one academic center, between January 2005 and December 2019. Independent predictors for obstructive CAD were identified. A risk score was developed using multivariate logistic regression of designated variables. The accuracy and discriminative power of the predictive model were assessed. RESULTS: A total of 109 patients (24.1%) presented obstructive CAD. Six independent predictors were identified and included in the score: male gender (2 points), diabetes (1 point), dyslipidemia (1 point), smoking (1 point), peripheral arterial disease (1 point), and regional wall motion abnormalities (3 points). Patients with a score ≤3 had less than 15% predicted probability of obstructive CAD. Our score showed good discriminative power (C-statistic 0.872; 95% CI 0.834-0.909: p<0.001) and calibration (p=0.333 from the goodness-of-fit test). CONCLUSIONS: A simple clinical score showed the ability to predict the risk of obstructive CAD in patients presenting with new-onset HFrEF of unknown etiology and may guide the clinician in selecting the most appropriate diagnostic modality for the assessment of obstructive CAD.proofepub_ahead_of_prin

    Single photon emission computed tomography, invasive coronary angiography and cardiac computed tomography angiography

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    Introduction: Diagnostic tests that use ionizing radiation play a central role in cardiology and their use has grown in recent years, leading to increasing concerns about their potential stochas-tic effects. The aims of this study were to compare the radiation dose of three diagnostic tests: single photon emission computed tomography (SPECT), invasive coronary angiography (ICA) and cardiac computed tomography (cardiac CT) and their evolution over time, and to assess the influence of body mass index on radiation dose. Methods: We assessed consecutive patients included in three prospective registries (SPECT, ICA and cardiac CT) over a period of two years. Radiation dose was converted to mSv and compared between the three registries. Differences over time were evaluated by comparing the first with the fourth semester. Results: A total of 6196 exams were evaluated: 35% SPECT, 53% ICA and 22% cardiac CT. Mean radiation dose was 10.7±1.2 mSv for SPECT, 8.1±6.4 mSv for ICA, and 5.4±3.8 mSv for cardiac CT (p<0.001 for all). With regard to the radiation dose over time, there was a very small reduction in SPECT (10.7 to 10.5 mSv, p=0.004), a significant increase (25%) in ICA (7.0 to 8.8mSv; p<0.001), and a significant reduction (29%) in cardiac CT (6.5 to 4.6 mSv, p<0.001). Obesity was associated with a significantly higher radiation dose in all three exams. Conclusions: Cardiac CT had a lower mean effective radiation dose than invasive coronary angiography, which in turn had a lower mean effective dose than SPECT. There was a significant increase in radiation doses in the ICA registry and a significant decrease in the cardiac CT registry over time.publishersversionpublishe

    Adoption and patterns of use of invasive physiological assessment of coronary artery disease in a large cohort of 40 821 real-world procedures over a 12-year period

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    Funding Information: The authors wish to acknowledge the invaluable contributions of Paulo Leal regarding data acquisition and management, and John Henderson for statistical consultancy. Publisher Copyright: © 2021 Sociedade Portuguesa de CardiologiaIntroduction and Objectives: Use of invasive physiological assessment in patients with coronary artery disease varies widely and is perceived to be low. We aimed to examine adoption rates as well as patterns and determinants of use in an unselected population undergoing invasive coronary angiography over a long time frame. Methods: We retrospectively determined the per-procedure prevalence of physiological assessment in 40 821 coronary cases performed between 2007 and 2018 in two large-volume centers. Adoption was examined according to procedure type and patient- and operator-related variables. Its association with relevant scientific landmarks, such as the release of clinical trial results and practice guidelines, was also assessed. Results: Overall adoption was low, ranging from 0.6% in patients undergoing invasive coronary angiography due to underlying valve disease, to 6% in the setting of stable coronary artery disease (CAD); it was 3.1% in patients sustaining an acute coronary syndrome. Of scientific landmarks, FAME 1, the long-term results of FAME 2 and the 2014 European myocardial revascularization guidelines were associated with changes in practice. Publication of instantaneous wave-free ratio (iFR) trials had no influence on adoption rates, except for a higher proportion of iFR use. In 42.9% of stable CAD patients undergoing percutaneous coronary intervention there was no objective non-invasive evidence of ischemia, nor was physiological assessment performed. Younger operator age (4.5% vs. 4.0% vs. 0.9% for ages 55 years, respectively; p<0.001) and later time of procedure during the day (2.9% between 6 and 8 p.m. vs. 4.4% at other times) were independent correlates of use of invasive physiology. Conclusions: Our study confirms the low use of invasive physiology in routine practice. The availability of resting indices did not increase adoption. Strategies are warranted to promote guideline implementation and to improve patient care and clinical outcomes.publishersversionpublishe

    Valorização comercial de uma amostra de própolis do Gerês (Portugal)

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    O própolis e um material resinoso produzido por abelhas a partir de exsudados de plantas. Tem vindo a ser considerado um produto de excelência visto exibir inúmeras propriedades biológicas[1] . Atualmente, a dimensão do mercado global do própolis e avaliado em cerca de 2300 toneladas e estima-se atingir as 2900 toneladas em 2021, revelando-se um mercado promissor para utilizações nas indústrias farmacêutica, cosmética, alimentar e na apiterapia [2]. Porem, própolis de diferentes regiões geográficas podem apresentar diferentes composições químicas e, portanto, um perfil de propriedades biológicas distinto e/ou atividades específicas com eficiências muito distintas

    The coronary artery disease equivalent revisited

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    (1) To study the prevalence and severity of coronary artery disease (CAD) in diabetic patients. (2) To provide a detailed characterization of the coronary atherosclerotic burden, including the localization, degree of stenosis and plaque composition by coronary computed tomography angiography (CCTA). Single center prospective registry including a total of 581 consecutive stable patients (April 2011-March 2012) undergoing CCTA (Dual-source CT) for the evaluation of suspected CAD without previous myocardial infarction or revascularization procedures. Different coronary plaque burden indexes and plaque type and distribution patterns were compared between patients with (n = 85) and without diabetes (n = 496). The prevalence of CAD (any plaque; 74.1 vs. 56 %; p = 0.002) and obstructive CAD (≥50 % stenosis; 31.8 vs. 10.3 %; p<0.001) were significantly higher in diabetic patients. The remaining coronary atherosclerotic burden indexes evaluated (plaque in LM-3v-2v with prox. LAD; SIS; SSS; CT-LeSc) were also significantly higher in diabetic patients. In the per segment analysis, diabetics had a higher percentage of segments with plaque in every vessel (2.6/13.1/7.5/10.5 % for diabetics vs. 1.4/7.1/3.3/4.4 % for nondiabetics for LM, LAD, LCx, RCA respectively; p<0.001 for all) and of both calcified (19.3 vs. 9.2 %, p<0.001) and noncalcified or mixed types (14.4 vs. 7.0 %; p<0.001); the ratio of proximal-to-distal relative plaque distribution (calculated as LM/proximal vs. mid/distal/branches) was lower for diabetics (0.75 vs. 1.04; p = 0.009). Diabetes was an independent predictor of CAD and was also associated with more advanced CAD, evaluated by indexes of coronary atherosclerotic burden. Diabetics had a significantly higher prevalence of plaques in every anatomical subset and for the different plaque composition. In this report, the relative geographic distribution of the plaques within each subgroup, favored a more mid-to-distal localization in the diabetic patients.publishersversionpublishe
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