The Epidemiology and Health Economics of Ankle Injuries

Thesis (Ph.D, Community Health & Epidemiology) -- Queen's University, 2016-10-03 22:59:05.858

Caracterização do perfil lesional em futebolistas juniores da 2ª Divisão Distrital e análise do impacto do programa “FIFA 11+” na performance física e na prevenção de lesões

Projeto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciado em Fisioterapia

Growth of bainitic ferrite and carbon partitioning during the early stages of bainite transformation in a 2 mass% silicon steel studied by in situ neutron diffraction, TEM and APT

In situ neutron diffraction, transmission electron microscopy (TEM) and atom probe tomography (APT) have been used to study the early stages of bainite transformation in a 2 mass% Si nano-bainitic steel. It was observed that carbon redistribution between the bainitic ferrite and retained austenite at the early stages of the bainite transformation at low isothermal holding occurred in the following sequence: (i) formation of bainitic ferrite nuclei within carbon-depleted regions immediately after the beginning of isothermal treatment; (ii) carbon partitioning immediately after the formation of bainitic ferrite nuclei but substantial carbon diffusion only after 33 min of bainite isothermal holding; (iii) formation of the carbon-enriched remaining austenite in the vicinity of bainitic laths at the beginning of the transformation; (iv) segregation of carbon to the dislocations near the austenite/ferrite interface; and (v) homogeneous redistribution of carbon within the remaining austenite with the progress of the transformation and with the formation of bainitic ferrite colonies. Bainitic ferrite nucleated at internal defects or bainite/austenite interfaces as well as at the prior austenite grain boundary. Bainitic ferrite has been observed in the form of an individual layer, a colony of layers and a layer with sideplates at the early stages of transformation.

A model of grain fragmentation based on lattice curvature

A new model is proposed that aims to capture within a single modelling frame all the main microstructural features of a severe plastic deformation process. These are: evolution of the grain size distribution, misorientation distribution, crystallographic texture and the strain-hardening of the material. The model is based on the lattice curvature that develops in all deformed grains. The basic assumption is that lattice rotation within an individual grain is impeded near the grain boundaries by the constraining effects of the neighbouring grains, which gives rise to lattice curvature. On that basis, a fragmentation scheme is developed which is integrated in the Taylor viscoplastic polycrystal model. Dislocation density evolution is traced for each grain, which includes the contribution of geometrically necessary dislocations associated with lattice curvature. The model is applied to equal-channel angular pressing. The role of texture development is shown to be an important element in the grain fragmentation process. Results of this modelling give fairly precise predictions of grain size and grain misorientation distribution. The crystallographic textures are well reproduced and the strength of the material is also reliably predicted based on the modelling of dislocation density evolution coupled with texture development.

Factores asociados a mortalidad en pacientes con enfermedades autoinmunes en cuidado intensivo, Hospital de la Samaritana 2007-2013

Introducción y objetivos: Las enfermedades autoinmunes en cuidado intensivo están relacionadas con tasas de mortalidad elevadas. El propósito del presente estudio fue buscar factores asociados a mortalidad en estos pacientes. Materiales y métodos: estudio observacional de casos incidentes, retrospectivo, en base a revisión de historias clínicas de los pacientes que ingresaron a la unidad de cuidado intensivo del Hospital Universitario de la Samaritana; se recolecto un total de 68 eventos con los que se evaluó la relación de las variables estudiadas con mortalidad. Resultados: Las enfermedades autoinmunes se presentan más frecuentemente en mujeres (66%), el lupus eritematoso sistémico fue la afección reumatológica más común (36%), el promedio de edad fue de 46 años, la media de días en ventilación mecánica fue de 10 (desviación estándar 13 días), el valor del APACHE promedio fue de 19 puntos, el sistema orgánico más afectado fue el renal (58,5%) y la mortalidad global fue de 40%. Se encontró asociación estadísticamente significativa con cinco variables: presencia de shock al ingreso a UCI OR: 7,368 (IC95% 1,886-28,794); nivel de procalcitonina mayor a 10 OR: 5,231 (IC95% 1,724-15,869); complemento C3 consumido OR: 4,014 (IC95% 1,223-13,173); serositis en la radiografía de tórax OR: 3,771 (IC95% 1,238-11,492); recuento de plaquetas menor a 100.000 OR: 3,33 (IC95%: 1,037-10,714). Conclusión: Existen factores que pueden estar asociados con mortalidad en pacientes con enfermedades autoinmunes en cuidado intensivo, su detección temprana y manejo oportuno podría mejorar el pronóstico de estos pacientes.