246 research outputs found

    Evaluation of the total photoabsorption cross sections for actinides from photofission data and model calculations

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    We have calculated the fission probabilities for 237-Np, 233,235,238-U, 232-Th, and nat-Pb following the absorption of photons with energies from 68 MeV to 3.77 GeV using the RELDIS Monte-Carlo code. This code implements the cascade-evaporation-fission model of intermediate-energy photonuclear reactions. It includes multiparticle production in photoreactions on intranuclear nucleons, pre-equilibrium emission, and the statistical decay of excited residual nuclei via competition of evaporation, fission, and multifragmentation processes. The calculations show that in the GeV energy region the fission process is not solely responsible for the entire total photoabsorption cross section, even for the actinides: ~55-70% for 232-Th, \~70-80% for 238-U, and ~80-95% for 233-U, 235-U, and 237-Np. This is because certain residual nuclei that are created by deep photospallation at GeV photon energies have relatively low fission probabilities. Using the recent experimental data on photofission cross sections for 237-Np and 233,235,238-U from the Saskatchewan and Jefferson Laboratories and our calculated fission probabilities, we infer the total photoabsorption cross sections for these four nuclei. The resulting cross sections per nucleon agree in shape and in magnitude with each other. However, disagreement in magnitude with total-photoabsorption cross-section data from previous measurements for nuclei from C to Pb calls into question the concept of a ``Universal Curve'' for the photoabsorption cross section per nucleon for all nuclei.Comment: 39 pages including 11 figure

    A novel procedure for genotyping of single nucleotide polymorphisms in trisomy with genomic DNA and the invader assay

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    Individuals with trisomy 21 display complex phenotypes with differing degrees of severity. Numerous reliable methods have been established to diagnose the initial trisomy in these patients, but the identification and characterization of the genetic basis of the phenotypic variation in individuals with trisomy remains challenging. To date, methods that can accurately determine genotypes in trisomic DNA samples are expensive, require specialized equipment and complicated analyses. Here we report proof-of-concept results for an Invader® assay-based genotyping procedure that can determine SNP genotypes in trisomic genomic DNA samples in a simple and cost-effective manner. The procedure requires only two experimental steps: a real-time measurement of the fluorescent Invader® signal and analysis with a specifically designed clustering algorithm. The approach was tested using genomic DNA samples from 23 individuals with trisomy 21, and results were compared to genotypes previously determined with pyrosequencing. Additional assays for 15 SNPs were tested in a set of 21 DNA samples to assess assay performance. Our method successfully identified the correct SNP genotypes for the trisomic genomic DNA samples tested, and thus provides an alternative to determine SNP genotypes in trisomic DNA samples for subsequent association studies in patients with Down syndrome and other trisomies

    Noninvasive Assessment of Coronary Artery Disease in Women: What’s Next?

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    Significant progress in research has been made in the areas of sex-specific aspects of cardiovascular disease. Despite these advances, coronary artery disease (CAD) is the leading cause of death of women in the Western world. Over the past decade, the focused research on women at risk for ischemic heart disease has helped to clarify our understanding of some of the sex-specific factors, which are important in detecting CAD. In women, the detection and evaluation of physiologically significant CAD is challenging, especially given that traditional tests designed to detect focal areas of coronary artery stenosis are less sensitive and specific in female patients who have a lower prevalence of obstructive coronary disease, greater burden of symptoms, and a high atherosclerotic burden. In this article, we review the available evidence on the role of contemporary cardiovascular imaging techniques in evaluating ischemic heart disease in women

    Usefulness of C-reactive protein as a marker of early post-infarct left ventricular systolic dysfunction

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    Objective To assess the usefulness of in-hospital measurement of C-reactive protein (CRP) concentration in comparison to well-established risk factors as a marker of post-infarct left ventricular systolic dysfunction (LVSD) at discharge. Materials and methods Two hundred and four consecutive patients with ST-segment-elevation myocardial infarction (STEMI) were prospectively enrolled into the study. CRP plasma concentrations were measured before reperfusion, 24 h after admission and at discharge with an ultra-sensitive latex immunoassay. Results CRP concentration increased significantly during the first 24 h of hospitalization (2.4 ± 1.9 vs. 15.7 ± 17.0 mg/L; p\0.001) and persisted elevated at discharge (14.7 ± 14.7 mg/L), mainly in 57 patients with LVSD (2.4 ± 1.8 vs. 25.0 ± 23.4 mg/L; p\0.001; CRP at discharge 21.9 ± 18.6 mg/L). The prevalence of LVSD was significantly increased across increasing tertiles of CRP concentration both at 24 h after admission (13.2 vs. 19.1 vs. 51.5 %; p\0.0001) and at discharge (14.7 vs. 23.5 vs. 45.6 %; p\0.0001). Multivariate analysis demonstrated CRP concentration at discharge to be an independent marker of early LVSD (odds ratio of 1.38 for a 10 mg/L increase, 95 % confidence interval 1.01–1.87; p\0.04). Conclusion Measurement of CRP plasma concentration at discharge may be useful as a marker of early LVSD in patients after a first STEMI

    Permanent education in health: a review

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    OBJECTIVE : To undertake a meta-synthesis of the literature on the main concepts and practices related to permanent education in health. METHODS : A bibliographical search was conducted for original articles in the PubMed, Web of Science, LILACS, IBECS and SciELO databases, using the following search terms: “public health professional education”, “permanent education”, “continuing education”, “permanent education health”. Of the 590 articles identified, after applying inclusion and exclusion criteria, 48 were selected for further analysis, grouped according to the criteria of key elements, and then underwent meta-synthesis. RESULTS : The 48 original publications were classified according to four thematic units of key elements: 1) concepts, 2) strategies and difficulties, 3) public policies and 4) educational institutions. Three main conceptions of permanent education in health were found: problem-focused and team work, directly related to continuing education and education that takes place throughout life. The main strategies for executing permanent education in health are discussion, maintaining an open space for permanent education, and permanent education clusters. The most limiting factor is mainly related to directly or indirect management. Another highlight is the requirement for implementation and maintenance of public policies, and the availability of financial and human resources. The educational institutions need to combine education and service aiming to form critical-reflexive graduates. CONCLUSIONS : The coordination between health and education is based as much on the actions of health services as on management and educational institutions. Thus, it becomes a challenge to implement the teaching-learning processes that are supported by critical-reflexive actions. It is necessary to carry out proposals for permanent education in health involving the participation of health professionals, teachers and educational institutions.OBJETIVO : Realizar metasíntesis de la literatura sobre los principales conceptos y prácticas relacionados con la educación permanente en salud. MÉTODOS : Se realizó búsqueda bibliográfica de artículos originales en las bases de datos PubMed, Web of Science, Lilacs, IBECS y SciELO, utilizando los siguientes descriptores: “ public health professional education”, “permanent education”, “continuing education”, “permanent education health ”. De un total de 590 artículos identificados, posterior a los criterios de inclusión y exclusión, fueron seleccionados 48 para análisis, los cuales fueron sometidos al análisis individual, análisis comparativo, análisis con criterios de agrupamiento de elementos-clave y sometidos a metasíntesis. RESULTADOS : Los 48 artículos originales fueron clasificados como elementos-clave en cuatro unidades temáticas: 1) Concepciones; 2) Estrategias y dificultades; 3) Políticas públicas e 4) Instituciones formadoras. Se encontraron tres concepciones principales de educación permanente en salud: ubicación del problema y enfocarlo en el trabajo en equipo, directamente relacionado con la educación continua y educación que se da a lo largo de la vida. Las principales estrategias para efectivar la educación permanente fueron la ubicación del problema, mantenimiento de espacios para la educación permanente y polos de educación permanente. El mayor factor limitante estuvo relacionado con la gerencia directa o indirecta. Fueron mencionadas la necesidad de implementación y mantenimiento de políticas públicas, así como la disponibilidad de recursos financieros y humanos. Las instituciones formadoras tendrían la necesidad de articular educación y servicio para la formación de egresados críticos-reflexivos. CONCLUSIONES : La articulación educación y salud se encuentra pautada tanto en las acciones de los servicios de salud, cuanto en la gestión y de instituciones formadoras. Así, se torna un desafío implementar procesos de educación-aprendizaje que sean respaldados por acciones crítico-reflexivas. Es necesario realizar propuestas de educación permanente en salud con la participación de profesionales de los servicios, profesores y profesionales de las instituciones de educación.OBJETIVO : Realizar metassíntese da literatura sobre os principais conceitos e práticas relacionados à educação permanente em saúde. MÉTODOS : Foi realizada busca bibliográfica de artigos originais nas bases de dados PubMed, Web of Science, Lilacs, IBECS e SciELO, utilizando os seguintes descritores: “ public health professional education ”, “ permanent education”, “continuing education ”, “ permanent education health ”. De um total de 590 artigos identificados, após os critérios de inclusão e exclusão, foram selecionados 48 para análise, os quais foram submetidos à análise individual, análise comparativa, análise com critérios de agrupamentos de elementos-chave e submetidos à metassíntese. RESULTADOS : Os 48 artigos originais foram classificados como elementos-chave em quatro unidades temáticas: 1) Concepções; 2) Estratégias e dificuldades; 3) Políticas públicas; e 4) Instituições formadoras. Foram encontradas três concepções principais de educação permanente em saúde: problematizadora e focada no trabalho em equipe, diretamente relacionada à educação continuada e educação que se dá ao longo da vida. As principais estratégias para efetivação da educação permanente foram a problematização, manutenção de espaços para a educação permanente e polos de educação permanente. O maior fator limitante foi relacionado à gerência direta ou indireta. Foram indicadas a necessidade de implementação e manutenção de políticas públicas, além de disponibilidade de recursos financeiros e de recursos humanos. As instituições formadoras teriam necessidade de articular ensino e serviço para a formação de egressos críticos-reflexivos. CONCLUSÕES : A articulação educação e saúde encontra-se pautada tanto nas ações dos serviços de saúde, quanto de gestão e de instituições formadoras. Assim, torna-se um desafio implementar processos de ensino-aprendizagem que sejam respaldados por ações crítico-reflexivas. É necessário realizar propostas de educação permanente em saúde com a participação de profissionais dos serviços, professores e profissionais das instituições de ensino

    Non-invasive cardiac imaging techniques and vascular tools for the assessment of cardiovascular disease in type 2 diabetes mellitus

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    Cardiovascular disease is the major cause of mortality in type 2 diabetes mellitus. The criteria for the selection of those asymptomatic patients with type 2 diabetes who should undergo cardiac screening and the therapeutic consequences of screening remain controversial. Non-invasive techniques as markers of atherosclerosis and myocardial ischaemia may aid risk stratification and the implementation of tailored therapy for the patient with type 2 diabetes. In the present article we review the literature on the implementation of non-invasive vascular tools and cardiac imaging techniques in this patient group. The value of these techniques as endpoints in clinical trials and as risk estimators in asymptomatic diabetic patients is discussed. Carotid intima–media thickness, arterial stiffness and flow-mediated dilation are abnormal long before the onset of type 2 diabetes. These vascular tools are therefore most likely to be useful for the identification of ‘at risk’ patients during the early stages of atherosclerotic disease. The additional value of these tools in risk stratification and tailored therapy in type 2 diabetes remains to be proven. Cardiac imaging techniques are more justified in individuals with a strong clinical suspicion of advanced coronary heart disease (CHD). Asymptomatic myocardial ischaemia can be detected by stress echocardiography and myocardial perfusion imaging. The more recently developed non-invasive multi-slice computed tomography angiography is recommended for exclusion of CHD, and can therefore be used to screen asymptomatic patients with type 2 diabetes, but has the associated disadvantages of high radiation exposure and costs. Therefore, we propose an algorithm for the screening of asymptomatic diabetic patients, the first step of which consists of coronary artery calcium score assessment and exercise ECG
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