998 resultados para MC-Sym
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Lisbon is the largest urban area in the Western European coast. Due to this geographical position the Atlantic Ocean serves as an important source of particles and plays an important role in many atmospheric processes. The main objectives of this study were to (1) perform a chemical characterization of particulate matter (PM2.5) sampled in Lisbon, (2) identify the main sources of particles, (3) determine PM contribution to this urban area, and (4) assess the impact of maritime air mass trajectories on concentration and composition of respirable PM sampled in Lisbon. During 2007, PM2.5 was collected on a daily basis in the center of Lisbon with a Partisol sampler. The exposed Teflon filters were measured by gravimetry and cut into two parts: one for analysis by instrumental neutron activation analysis (INAA) and the other by ion chromatography (IC). Principal component analysis (PCA) and multilinear regression analysis (MLRA) were used to identify possible sources of PM2.5 and determine mass contribution. Five main groups of sources were identified: secondary aerosols, traffic, calcium, soil, and sea. Four-day backtracking trajectories ending in Lisbon at the starting sampling time were calculated using the HYSPLIT model. Results showed that maritime transport scenarios were frequent. These episodes were characterized by a significant decrease of anthropogenic aerosol concentrations and exerted a significant role on air quality in this urban area.
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The objectives of this study were to (1) conduct an elemental characterization of airborne particles sampled in Cape Verde and (2) assess the influence of Sahara desert on local suspended particles. Particulate matter (PM10) was collected in Praia city (14°94'N; 23°49'W) with a low-volume sampler in order to characterize its chemical composition by k0-INAA. The filter samples were first weighed and subsequently irradiated at the Portuguese Research Reactor. Results showed that PM10 concentrations in Cape Verde markedly exceeded the health-based air quality standards defined by the European Union (EU), World Health Organization (WHO), and U.S. Environmental Protection Agency (EPA), in part due to the influence of Sahara dust transport. The PM10 composition was characterized essentially by high concentrations of elements originating from the soil (K, Sm, Co, Fe, Sc, Rb, Cr, Ce, and Ba) and sea (Na), and low concentrations of anthropogenic elements (As, Zn, and Sb). In addition, the high concentrations of PM measured in Cape Verde suggest that health of the population may be less affected compared with other sites where PM10 concentrations are lower but more enriched with toxic elements.
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RESUMO: A mamografia é o método de diagnóstico mais eficaz para deteção precoce de carcinoma da mama. A realização periódica deste exame tem vindo a ser associada a melhores prognósticos como deteção da doença em fases mais precoces e redução de mortalidade. Contudo, a mamografia não é encarada como mais um exame complementar de diagnóstico e constitui, para a maioria das mulheres, uma situação de ameaça. Na verdade, muitas mulheres referem ter experienciado ansiedade, dor ou desconforto durante a realização deste procedimento. Por outro lado, uma percentagem elevada de mulheres falha na realização periódica de mamografias. Este artigo pretende abordar as reações psicológicas associadas ao exame de mamografia e enfatizar a forma como os técnicos de radiologia podem melhorar o atendimento das mulheres que realizam este exame. O papel do técnico de radiologia no fornecimento de informação antes do exame, na criação de uma atmosfera agradável e empática e na utilização de estratégias de confronto para redução de dor e desconforto e na promoção do controlo e autonomia da paciente são alguns dos aspetos abordados.
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The International Agency for Research on Cancer classified formaldehyde as carcinogenic to humans because there is “sufficient epidemiological evidence that it causes nasopharyngeal cancer in humans”. Genes involved in DNA repair and maintenance of genome integrity are critically involved in protecting against mutations that lead to cancer and/or inherited genetic disease. Association studies have recently provided evidence for a link between DNA repair polymorphisms and micronucleus (MN) induction. We used the cytokinesis-block micronucleus (CBMN assay) in peripheral lymphocytes and MN test in buccal cells to investigate the effects of XRCC3 Thr241Met, ADH5 Val309Ile, and Asp353Glu polymorphisms on the frequency of genotoxicity biomarkers in individuals occupationally exposed to formaldehyde (n = 54) and unexposed workers (n = 82). XRCC3 participates in DNA double-strand break/recombination repair, while ADH5 is an important component of cellular metabolism for the elimination of formaldehyde. Exposed workers had significantly higher frequencies (P < 0.01) than controls for all genotoxicity biomarkers evaluated in this study. Moreover, there were significant associations between XRCC3 genotypes and nuclear buds, namely XRCC3 Met/Met (OR = 3.975, CI 1.053–14.998, P = 0.042) and XRCC3 Thr/Met (OR = 5.632, CI 1.673–18.961, P = 0.005) in comparison with XRCC3 Thr/Thr. ADH5 polymorphisms did not show significant effects. This study highlights the importance of integrating genotoxicity biomarkers and genetic polymorphisms in human biomonitoring studies.
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Mestrado em Segurança e Higiene do Trabalho.
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OBJETIVO: Analisar a qualidade de vida relacionada à saúde de pacientes com osteoporose e compará-la com a população geral. MÉTODOS: Foi realizado um estudo descritivo transversal com 60 pacientes do sexo feminino no serviço de reumatologia de um hospital universitário na Espanha, de abril a outubro de 2003. Foi aplicado o questionário Short Form-36, abordando dados demográficos, características clínicas e dados sobre estilos de vida relacionados à saúde. As pacientes foram classificadas em grupos etários. Foram utilizados os seguintes testes estatísticos: qui-quadrado, modelo linear geral, t de Student. RESULTADOS: As entrevistadas tinham idade média de 65,57 (DP: ±9,7 anos), e tempo de diagnóstico médio de 3,4±2,84 anos. As melhores pontuações foram obtidas nas dimensões aspectos sociais (89), aspectos emocionais (72,2) e saúde mental (63). As mais baixas foram em estado geral de saúde (45,1), capacidade funcional (47,7), dor (52,3) e aspectos físicos (59,9). As pontuações médias dos pacientes resultaram inferiores às pontuações conhecidas da população geral espanhola nas dimensões capacidade funcional, aspectos físicos, dor e estado geral de saúde. As máximas diferenças entre as pontuações médias do SF-36 dos pacientes e os valores populacionais espanhóis correspondem ao grupo de idade de 55 a 64 anos. Nas demais dimensões do SF-36, as pontuações foram inferiores ou similares aos valores populacionais espanhóis. Não se encontraram associações significativas entre as dimensões do SF-36 estudadas e os dados clínicos, demográficos e de estilos de vida analisados. CONCLUSÕES: Os pacientes apresentaram baixa qualidade de vida, sobretudo nas dimensões mais relevantes da enfermidade, quando comparada com valores da população espanhola em geral. As áreas físicas foram as mais afetadas.
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XIX Simposio de Botánica Criptogámica, Las Palmas de Gran Canaria, 24-28 de junio de 2013.
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10th International Phycological Congress, Orlando, Florida, USA, 4-10 de agosto 2013.
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Jornadas "Ciência nos Açores – que futuro?", Ponta Delgada, 7-8 de Junho de 2013.
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XIX Simposio de Botánica Criptogámica, Las Palmas de Gran Canaria, 24-28 de junio de 2013.
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10th International Phycological Congress, Orlando, Florida, USA, 4-10 de agosto 2013.
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O ambiente marinho constitui uma extraordinária reserva de compostos com características estruturais únicas, diferentes das encontradas nos Produtos Naturais de origem terrestre. Os compostos de origem marinha assumem assim um papel cada vez mais significativo na descoberta de novos medicamentos, de novas aplicações em cosmética, na produção de enzimas com características específicas ou como biomateriais para engenharia de tecidos. A investigação nesta área, no âmbito do Crescimento Azul, ganhou novo impulso com a Estratégia Nacional para o Mar e as diretivas do Horizonte 2020. A elevada biodiversidade do mar dos Açores e os ambientes e ecossistemas que o distinguem de outras regiões, nomeadamente a influência do vulcanismo ativo e residual, estão na base da investigação que tem vindo a ser feita na Universidade dos Açores, pelo Grupo de Biotecnologia do Centro de Investigação em Recursos Naturais (CIRN), em colaboração com o DCTD, DB e CIBIO-Açores.
The use of non-standard CT conversion ramps for Monte Carlo verification of 6 MV prostate IMRT plans
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Monte Carlo (MC) dose calculation algorithms have been widely used to verify the accuracy of intensity-modulated radiotherapy (IMRT) dose distributions computed by conventional algorithms due to the ability to precisely account for the effects of tissue inhomogeneities and multileaf collimator characteristics. Both algorithms present, however, a particular difference in terms of dose calculation and report. Whereas dose from conventional methods is traditionally computed and reported as the water-equivalent dose (Dw), MC dose algorithms calculate and report dose to medium (Dm). In order to compare consistently both methods, the conversion of MC Dm into Dw is therefore necessary. This study aims to assess the effect of applying the conversion of MC-based Dm distributions to Dw for prostate IMRT plans generated for 6 MV photon beams. MC phantoms were created from the patient CT images using three different ramps to convert CT numbers into material and mass density: a conventional four material ramp (CTCREATE) and two simplified CT conversion ramps: (1) air and water with variable densities and (2) air and water with unit density. MC simulations were performed using the BEAMnrc code for the treatment head simulation and the DOSXYZnrc code for the patient dose calculation. The conversion of Dm to Dw by scaling with the stopping power ratios of water to medium was also performed in a post-MC calculation process. The comparison of MC dose distributions calculated in conventional and simplified (water with variable densities) phantoms showed that the effect of material composition on dose-volume histograms (DVH) was less than 1% for soft tissue and about 2.5% near and inside bone structures. The effect of material density on DVH was less than 1% for all tissues through the comparison of MC distributions performed in the two simplified phantoms considering water. Additionally, MC dose distributions were compared with the predictions from an Eclipse treatment planning system (TPS), which employed a pencil beam convolution (PBC) algorithm with Modified Batho Power Law heterogeneity correction. Eclipse PBC and MC calculations (conventional and simplified phantoms) agreed well (<1%) for soft tissues. For femoral heads, differences up to 3% were observed between the DVH for Eclipse PBC and MC calculated in conventional phantoms. The use of the CT conversion ramp of water with variable densities for MC simulations showed no dose discrepancies (0.5%) with the PBC algorithm. Moreover, converting Dm to Dw using mass stopping power ratios resulted in a significant shift (up to 6%) in the DVH for the femoral heads compared to the Eclipse PBC one. Our results show that, for prostate IMRT plans delivered with 6 MV photon beams, no conversion of MC dose from medium to water using stopping power ratio is needed. In contrast, MC dose calculations using water with variable density may be a simple way to solve the problem found using the dose conversion method based on the stopping power ratio.
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Throughout the world, epidemiological studies were established to examine the relationship between air pollution and mortality rates and adverse respiratory health effects. However, despite the years of discussion the correlation between adverse health effects and atmospheric pollution remains controversial, partly because these studies are frequently restricted to small and well-monitored areas. Monitoring air pollution is complex due to the large spatial and temporal variations of pollution phenomena, the high costs of recording instruments, and the low sampling density of a purely instrumental approach. Therefore, together with the traditional instrumental monitoring, bioindication techniques allow for the mapping of pollution effects over wide areas with a high sampling density. In this study, instrumental and biomonitoring techniques were integrated to support an epidemiological study that will be developed in an industrial area located in Gijon in the coastal of central Asturias, Spain. Three main objectives were proposed to (i) analyze temporal patterns of PM10 concentrations in order to apportion emissions sources, (ii) investigate spatial patterns of lichen conductivity to identify the impact of the studied industrial area in air quality, and (iii) establish relationships amongst lichen conductivity with some site-specific characteristics. Samples of the epiphytic lichen Parmelia sulcata were transplanted in a grid of 18 by 20 km with an industrial area in the center. Lichens were exposed for a 5-mo period starting in April 2010. After exposure, lichen samples were soaked in 18-MΩ water aimed at determination of water electrical conductivity and, consequently, lichen vitality and cell damage. A marked decreasing gradient of lichens conductivity relative to distance from the emitting sources was observed. Transplants from a sampling site proximal to the industrial area reached values 10-fold higher than levels far from it. This finding showed that lichens reacted physiologically in the polluted industrial area as evidenced by increased conductivity correlated to contamination level. The integration of temporal PM10 measurements and analysis of wind direction corroborated the importance of this industrialized region for air quality measurements and identified the relevance of traffic for the urban area.
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Background - Being patient centered is a core value for nursing. Patient centered-care has been related to patient and health provider satisfaction, better health outcomes, higher quality of care and more efficient health care delivery. Objectives - The purpose was to assess the orientation adopted by nurses and students in patient care, using The Patient-Practitioner Orientation Scale, as well as to compare the results between resident nurses and students from different academic years. Settings - Public School of Nursing and a Central Hospital, in Lisbon (Portugal). Participants - Students in the first, second and fourth year of nursing school and nurses participated in the study. Methods - For data collection, we used The Patient-Practitioner Orientation Scale (European Portuguese version), an instrument designed to measure individual preferences toward the dimension of caring a sharing in health professional-patient relationship. Students and nurses also filled out two additional questions about their perception of competence in technical and communication skills. Additional demographic information was also collected, including gender, age, academic year and length of professional experience. Results - A total of 525 students (84.7% female) and 108 nurses (77.8% female) participated in this study. In general, caring sub-scores, measuring the preference of about attending to patient emotional aspects, were higher than sharing sub-scores, measuring beliefs about giving information and perceiving patient as a member of the health team. Students were significantly more patient-centered throughout their nursing education (p<0.001). Comparing to students in the second and fourth academic years (p<0.001) nurses' scores were significantly lower both in total PPOS and in caring and sharing subscales. Conclusions - These results reinforce the idea that patient centeredness may be developed in academic context. The scores obtained highlight the importance of studies that aim to identify factors that may explain the decrease of patient centeredness in professional practice.