2,994 research outputs found

    Non-vascular interventional procedures: effective dose to patient and equivalent dose to abdominal organs by means of dicom images and Monte Carlo simulation

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    This study evaluates X-ray exposure in patient undergoing abdominal extra-vascular interventional procedures by means of Digital Imaging and COmmunications in Medicine (DICOM) image headers and Monte Carlo simulation. The main aim was to assess the effective and equivalent doses, under the hypothesis of their correlation with the dose area product (DAP) measured during each examination. This allows to collect dosimetric information about each patient and to evaluate associated risks without resorting to in vivo dosimetry. The dose calculation was performed in 79 procedures through the Monte Carlo simulator PCXMC (A PC-based Monte Carlo program for calculating patient doses in medical X-ray examinations), by using the real geometrical and dosimetric irradiation conditions, automatically extracted from DICOM headers. The DAP measurements were also validated by using thermoluminescent dosimeters on an anthropomorphic phantom. The expected linear correlation between effective doses and DAP was confirmed with an R(2) of 0.974. Moreover, in order to easily calculate patient doses, conversion coefficients that relate equivalent doses to measurable quantities, such as DAP, were obtained

    Near-critical free-surface flows: Real fluid flow analysis

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    An open channel flow with a flow depth close to the critical depth is characterised by a curvilinear streamline flow field that results in steady free surface undulations. Near critical flows of practical relevance encompass the undular hydraulic jump when the flow changes from supercritical (F > 1) to subcritical (F 1). So far these flows were mainly studied based on ideal fluid flow computations, for which the flow is assumed irrotational and, thus, shear forces are absent. While the approach is accurate for critical flow conditions (F = 1) in weir and flumes, near-critical flows involve long distances reaches, and the effect of friction on the flow properties cannot be neglected. In the present study the characteristics of near-critical free-surface flows are reanalysed based on a model accounting for both the streamline curvature and friction effects. Based on the improved model, some better agreement with experimental results is found, thereby highlighting the main frictional features of the flow profiles

    Detección molecular de infecciones múltiples en mujeres con y sin lesión de cuello uterino positivas para el virus del papiloma humano de alto riesgo, período 2007-2011

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    El cáncer de cuello uterino, causado por el virus del papiloma humano (HPV), constituye el tercer tipo de cáncer más común en mujeres en el mundo. El objetivo del presente trabajo fue determinar por reacción en cadena de la polimerasa seguida de hibridación reversa, la frecuencia de infecciones múltiples en mujeres positivas para HPV de alto riesgo oncogénico por captura híbrida II, según severidad de la lesión escamosa intraepitelial (SIL), carga viral relativa y edad, en el periodo 2007-2011. Este estudio de corte transverso incluyó 123 mujeres que acudieron al Instituto de Investigaciones en Ciencias de la Salud, 18 sin lesión (NSIL), 78 con SIL de bajo grado (LSIL) y 27 con SIL de alto grado (HSIL). Se detectaron infecciones múltiples en 37/123 mujeres (30,1%). Las mujeres con NSIL presentaron menor frecuencia de infecciones múltiples (5,6%) que las mujeres con SIL (34,3%) (p=0,03). No se observó aumento de frecuencia de infecciones múltiples con la severidad de la lesión, presentando las mujeres con LSIL un 34,6% y con HSIL, un 33,3%. No fue observada diferencia significativa entre la carga viral relativa de infecciones simples y múltiples, lo cual sugiere que en la infección múltiple podría ser solo uno de los tipos de HPV el que se esté replicando, causando una infección productiva. Además, se observó una alta frecuencia de infecciones múltiples (75%) en mujeres menores a 30 años. Finalmente los resultados sugieren que las infecciones múltiples podrían orientar la presencia de SIL, pero no el grado de severidad de la lesión cervical

    Use of mixed methods designs in substance research: a methodological necessity in Nigeria

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    The utility of mixed methods (qualitative and quantitative) is becoming increasingly accepted in health sciences, but substance studies are yet to substantially benefit from such utilities. While there is a growing number of mixed methods alcohol articles concerning developed countries, developing nations are yet to embrace this method. In the Nigerian context, the importance of mixed methods research is yet to be acknowledged. This article therefore, draws on alcohol studies to argue that mixed methods designs will better equip scholars to understand, explore, describe and explain why alcohol consumption and its related problems are increasing in Nigeria. It argues that as motives for consuming alcohol in contemporary Nigeria are multiple, complex and evolving, mixed method approaches that provide multiple pathways for proffering solutions to problems should be embraced

    Social representations and the politics of participation

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    Recent work has called for the integration of different perspectives into the field of political psychology (Haste, 2012). This chapter suggests that one possible direction that such efforts can take is studying the role that social representations theory (SRT) can play in understanding political participation and social change. Social representations are systems of common-sense knowledge and social practice; they provide the lens through which to view and create social and political realities, mediate people's relations with these sociopolitical worlds and defend cultural and political identities. Social representations are therefore key for conceptualising participation as the activity that locates individuals and social groups in their sociopolitical world. Political participation is generally seen as conditional to membership of sociopolitical groups and therefore is often linked to citizenship. To be a citizen of a society or a member of any social group one has to participate as such. Often political participation is defined as the ability to communicate one's views to the political elite or to the political establishment (Uhlaner, 2001), or simply explicit involvement in politics and electoral processes (Milbrath, 1965). However, following scholars on ideology (Eagleton, 1991; Thompson, 1990) and social knowledge (Jovchelovitch, 2007), we extend our understanding of political participation to all social relations and also develop a more agentic model where individuals and groups construct, develop and resist their own views, ideas and beliefs. We thus adopt a broader approach to participation in comparison to other political-psychological approaches, such as personality approaches (e.g. Mondak and Halperin, 2008) and cognitive approaches or, more recently, neuropsychological approaches (Hatemi and McDermott, 2012). We move away from a focus on the individual's political behaviour and its antecedents and outline an approach that focuses on the interaction between psychological and political phenomena (Deutsch and Kinnvall, 2002) through examining the politics of social knowledge

    Cell walls of the dimorphic fungal pathogens Sporothrix schenckii and Sporothrix brasiliensis exhibit bilaminate structures and sloughing of extensive and intact layers

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    This work was supported by the Fundação Carlos Chagas de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), grants E-26/202.974/2015 and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), grants 229755/2013-5, Brazil. LMLB is a senior research fellow of CNPq and Faperj. NG acknowledged support from the Wellcome Trust (Trust (097377, 101873, 200208) and MRC Centre for Medical Mycology (MR/N006364/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
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