Informação da dosimetria individual pelas organizações de saúde

A aplicação das radiações ionizantes na área da medicina tem vindo a crescer desde o século passado. Na área da medicina, existem três especialidades principais que desenvolvem as suas actividades recorrendo à aplicação de radiações ionizantes, no âmbito do diagnóstico e da terapêutica: a Medicina Nuclear, a Radiologia e a Radioterapia. Salienta-se uma quarta área, a Cardiopneumologia quando actua na cardiologia de intervenção. Segundo o Decreto-Lei nº 222/2008, de 17/11, cabe às Organizações de Saúde (OSs) a responsabilidade de assegurar a monitorização individual dos trabalhadores expostos a radiações ionizantes, a monitorização dos locais de trabalho e a vigilância médica dos trabalhadores expostos. No que respeita à monitorização individual dos profissionais, as OSs determinam qual e empresa que procederá ao fornecimento e leitura dos dosímetros, não esquecendo no momento da contratação o Decreto-Lei nº 222/2008, de 17/11, artigo 10, que salienta que a monitorização individual dos trabalhadores da categoria A deve ter uma periodicidade mensal, assim como as leituras de dosimetria individual também devem ser mensais. Todos os profissionais têm o direito de aceder a todos os dados referentes à sua monitorização individual das doses de radiação, incluindo os resultados das medições, individuais ou de área que levaram à estimação das doses recebidas. O objectivo geral deste estudo é verificar se as OSs notificam/informam os profissionais de saúde expostos a radiações ionizantes das leituras de dosimetria individual e com que periodicidade.

Mass- Radius Relation for Magnetized Strange Quarks Stars

We review the stability of magnetized strange quark matter (MSQM) within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the strange quark mass, baryon density, magnetic field and bag parameter. A comparison with magnetized asymmetric quark matter in beta-equilibrium as well as with strange quark matter (SQM) is presented. We obtain that the energy per baryon for MSQM decreases as the magnetic field increases, and its minimum value at vanishing pressure is lower than the value found for SQM, which implies that MSQM is more stable than non-magnetized SQM. The mass-radius relation for magnetized strange quark stars is also obtained in this framework.

Individual pension information: Recommendations for the case of Spain based on the experiences of other countries

The aim of this paper is to establish some basic guidelines to help draft the information letter sent to individual contributors should it be decided to use this model in the Spanish public pension system. With this end in mind and basing our work on the experiences of the most advanced countries in the field and the pioneering papers by Jackson (2005), Larsson et al. (2008) and Sunden (2009), we look into the concept of “individual pension information” and identify its most relevant characteristics. We then give a detailed description of two models, those in the United States and Sweden, and in particular look at how they are structured, what aspects could be improved and what their limitations are. Finally we make some recommendations of special interest for designing the model for Spain.

Estudo da resposta de um dosímetro eletrónico individual

Introdução – A monitorização da exposição ocupacional a doses de radiação ionizante pode ser complementada por dosímetros eletrónicos individuais que permitem uma leitura direta da dose de radiação recebida. Dada a dependência energética e de débito de dose já reportada para estes dosímetros, este trabalho pretende determinar a linearidade da resposta de um dosímetro eletrónico individual e estudar o comportamento da sua resposta em função da energia de radiação e do débito de dose. Metodologia – Para estudar a dependência da energia da radiação do dosímetro eletrónico pessoal Vertec Bleeper Sv procedeu‑se à sua irradiação com um equivalente de dose individual, Hp(10), de 500 μSv de radiação gama do Cobalto – 60 (60C) e Césio – 137 (137Cs) e das qualidades de radiação X da série Narrow (N): N‑30, N‑40, N‑60, N‑80, N‑100 e N‑120. Para investigar a dependência da resposta em função do débito de dose aplicaram‑se à ampola de raios X as intensidades de corrente elétrica de 1 mA, 5 mA, 10 mA, 15 mA e 20 mA. Resultados – Não existe uma relação entre a resposta do detetor e a energia de radiação a que este é exposto. Ocorre uma subestimação superior a 50% na grandeza medida para energias inferiores a 33 keV, mas ostenta uma medida relativamente linear da grandeza Hp(10) para doses inferiores a 100 μSv. Também se constata que, à medida que o débito de dose aumenta, existe uma diminuição na resposta do dosímetro. O menor decréscimo na resposta deste dosímetro eletrónico individual dá‑se para as qualidades de radiação N‑30 (1,1%), N‑40 (4,1%) e N‑120 (20,0%). Conclusão – Verifica‑se que a resposta do dosímetro individual Vertec Bleeper Sv depende fortemente da energia da radiação e do débito de dose. ABSTRACT: Introduction – The measurement of occupational exposure to radiation doses can be completed with an electronic personal dosemeter that allows a direct reading and alarm function of the received radiation dose. Due to the energy and dose rate dependence already reported for this type of dosemeter, it is intended, with this work, to determine the response linearity of an Electronic Personal Dosemeter and to study its response behavior to the dose rate and radiation energy. Methodology – The electronic personal dosemeter Vertec Bleeper Sv energy dependency was evaluated by its irradiation with 500 μSv from the radionuclides Cobalt – 60 (60C) and Cesium – 137 (137Cs) as well as by the radiation qualities of the Narrow (N) series: N‑30, N‑40, N‑60, N‑80, N‑100 e N‑120. To investigate the dose rate dependency, the intensities of electric current of 1 mA, 5 mA, 10 mA, 15 mA and 20 mA were applied to the X‑ray tube. Results – There is no relationship between the response of the detector and the radiation energy. For energies below 33 keV there is an underestimation over 50% of the radiation dose measured but the detector presents a linear response for energies under 100 μSv. A dependency on the dose rate is perceived since as the dose rate increases, the response of the individual monitor decreases. There is a smaller decrease for the radiation qualities of N‑30 (1.1%), N‑40 (4.1%) and N‑120 (20.0%). Conclusion – It is concluded that there is a strong dependence of radiation energy and dose rate on the response of an electronic personal dosemeter.

Compact Stars and Magnetized CFL Matter

The stability of the color flavor locked phase in the presence of a strong magnetic field is investigated within the phenomenological MIT bag model. It is found that the minimum value of the energy per baryon in a color flavor locked state at vanishing pressure is lower than the corresponding one for unpaired magnetized strange quark matter and, as the magnetic field increases, the energy per baryon decreases. This implies that magnetized color flavor locked matter is more stable and could become the ground state inside neutron stars. The anisotropy of the pressures is discussed. The mass-radius relation for such stars is also studied.

Experiencing flow while teaching and learning in individual tuition settings

Conferência anual da ISME

Magnetized color flavor locked state and compact stars

The stability of the color flavor locked phase in the presence of a strong magnetic field is investigated within the phenomenological MIT bag model, taking into account the variation of the strange quark mass, the baryon density, the magnetic field, as well as the bag and gap parameters. It is found that the minimum value of the energy per baryon in a color flavor locked state at vanishing pressure is lower than the corresponding one for unpaired magnetized strange quark matter and, as the magnetic field increases, the energy per baryon decreases. This implies that magnetized colorflavor locked matter is more stable and could become the ground state inside neutron stars. The mass-radius relation for such stars is also studied.

Monte Carlo simulation of the basic features of the GE Millennium MG single photon emission computed tomography gamma camera

Objective - To describe and validate the simulation of the basic features of GE Millennium MG gamma camera using the GATE Monte Carlo platform. Material and methods - Crystal size and thickness, parallel-hole collimation and a realistic energy acquisition window were simulated in the GATE platform. GATE results were compared to experimental data in the following imaging conditions: a point source of 99mTc at different positions during static imaging and tomographic acquisitions using two different energy windows. The accuracy between the events expected and detected by simulation was obtained with the Mann–Whitney–Wilcoxon test. Comparisons were made regarding the measurement of sensitivity and spatial resolution, static and tomographic. Simulated and experimental spatial resolutions for tomographic data were compared with the Kruskal–Wallis test to assess simulation accuracy for this parameter. Results - There was good agreement between simulated and experimental data. The number of decays expected when compared with the number of decays registered, showed small deviation (≤0.007%). The sensitivity comparisons between static acquisitions for different distances from source to collimator (1, 5, 10, 20, 30cm) with energy windows of 126–154 keV and 130–158 keV showed differences of 4.4%, 5.5%, 4.2%, 5.5%, 4.5% and 5.4%, 6.3%, 6.3%, 5.8%, 5.3%, respectively. For the tomographic acquisitions, the mean differences were 7.5% and 9.8% for the energy window 126–154 keV and 130–158 keV. Comparison of simulated and experimental spatial resolutions for tomographic data showed no statistically significant differences with 95% confidence interval. Conclusions - Adequate simulation of the system basic features using GATE Monte Carlo simulation platform was achieved and validated.

The Tetrahymena chaperonin subunit CCT eta gene is coexpressed with CCT gamma gene during cilia biogenesis and cell sexual reproduction

We report here the cloning and the characterization of the T. pyriformis CCT eta gene (TpCCT eta) and also a partial sequence of the corresponding T. thermophila gene (TtCCT eta). The TpCCt eta gene encodes a protein sharing a 60.3% identity with the mouse CCT eta. We have studied the expression of these genes in Tetrahymena exponentially growing cells, cells regenerating their cilia for different periods and during different stages of the cell sexual reproduction. These genes have similar patterns of expression to those of the previously identified TpCCt gamma gene. Indeed, the Tetrahymena CCT eta and CCT gamma genes are up-regulated at 60-120 min of cilia recovery, and in conjugation when vegetative growth was resumed and cell division took place. Our results seem to indicate that both CCT subunits play an important role in the biogenesis of the newly synthesized cilia of Tetrahymena and during its cell division.

O currículo específico individual práticas de construção e Implementação: um estudo exploratório no segundo ciclo

Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção do grau de Mestre em Educação - Especialização em Educação Especial

Gamma radiation effects on microbial inactivation of two medicinal plants

The consumption of natural products has become a public health problem, since these medicinal teas are prepared using natural plants without an effective hygienic and sanitary control. The aim of this study was to assess the effects of gamma radiation, on the microbial burden of two medicinal plants: Melissa officinalis and Lippia citriodora. Dried samples of the two plants were irradiated at a Co-60 experimental equipment. The applied gamma radiation doses were 1, 3, and 5 kGy at a dose rate of 1.34 kGy/h. Non-irradiated samples followed all the experiments. Bacterial and fungal counts were assessed before and after irradiation by membrane filtration method. Challenging tests with Escherichia coli were performed in order to evaluate the disinfection efficiency of gamma radiation treatment. Characterization of M. officinalis and L. citriadora microbiota indicated an average bioburden value of 102CFU/g. The inactivation studies of the bacterial mesophilic population of both dried plants pointed out to a one log reduction of microbial load after irradiation at 5 kGy. Regarding the fungal population, the initial load of 30 CFU/g was only reduced by 0.5 log by an irradiation dose of 5 kGy. The dynamics with radiation doses of plants microbial population’s phenotypes indicated the prevalence of gram-positive rods for M. officinalis before and after irradiation, and the increase of the frequency of gram-negative rods with irradiation for L. citriadora. Among fungal population of both plants, Mucor, Neoscytalidium, Aspergillus and Alternaria were the most isolated genera. The results obtained in the challenging tests with E. coli on plants pointed out to an inactivation efficiency of 99.5% and 99.9% to a dose of 2 kGy, for M.officinalis and L. citriadora, respectively. The gamma radiation treatment can be a significant tool for the microbial control in medicinal plants.

O trabalho individual e o trabalho de grupo no processo de ensino-aprendizagem do estudo do meio no 1º Ciclo

Relatório Final apresentado à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ensino do 1º e 2º ciclo do Ensino Básico

Rising stars: da ESTeSL para o mundo da radiologia

Serão apresentadas duas experiências que estudantes de radiologia da ESTeSL tiveram no estrangeiro: a experiência que as estudantes tiveram no seu ERASMUS em Viena de Áustria no 2º semestre de 2014/15 e o decorrer da Summer School OPTIMAX2015, em que as estudantes participaram em agosto de 2015, em Groningen, nos Países Baixos. Falar-se-á um pouco sobre os estudos em radiologia. Discutir-se-ão os desafios que são habitualmente apresentados a um estudante aquando da realização do seu artigo final de investigação, como se podem prevenir e ultrapassar esses obstáculos e construir um artigo científico de qualidade.

Embedded system for individual recognition based on ECG biometrics

Biometric recognition is emerging has an alternative solution for applications where the privacy of the information is crucial. This paper presents an embedded biometric recognition system based on the Electrocardiographic signals (ECG) for individual identification and authentication. The proposed system implements a real-time state-of-the-art recognition algorithm, which extracts information from the frequency domain. The system is based on a ARM Cortex 4. Preliminary results show that embedded platforms are a promising path for the implementation of ECG-based applications in real-world scenario.