Three transducers for one photodetector: essays for optical communications

Dissertation presented to obtain the PhD degree in Electrical and Computer Engineering - Electronics

Gastric adenocarcinoma: contribute of computed tomography in preoperative T nad N staging

RESUMO:Os recentes progressos na imagiologia médica possibilitaram um papel de destaque para a Tomografia Axial Computorizada Multicorte no estadiamento do carcinoma do estômago (GA). Foi objetivo deste estudo avaliar a acuidade desta técnica no estadiamento T (invasão mural) e N (ganglionar) e avaliar fatores de prognóstico como fatores de representação/substituição para melhorar a referida acuidade. Sessenta e nove pacientes operados a carcinoma gástrico (GA) entre Janeiro de 2010 e Julho de 2012 e avaliados por Tomografia Computorizada, a maioria recorrendo a técnica de multicorte com distensão gástrica, foram estadiados retrospetivamente por três imagiologistas. Utilizaram-se critérios de avaliação referidos na literatura especializada e fatores de substituição/representação nos estadios menos eficazes. O estadiamento T revelou acuidade de 66,7% e sensibilidade de 92% e a acuidade, sensibilidade e especificidade obtidas para o estadiamento N foram respetivamente 49%, 40,9% e 64%. Usando um fator de substituição de estadiamento diagnóstico T4/N2 para mudar o estadiamento N2 obtido por MDCT para estadiamento N3A aumentaria a acuidade do estadiamento N para 59% e a sensibilidade para 58,1% e baixaria a especificidade para 61,5%, embora essa mudança não fosse estatisticamente significativa (Teste exato de Fisher 0,159). Em conclusão a acuidade de uma técnica simples de MDCT com distensão gástrica no estadiamento T e N do GA está dentro dos valores citados na literatura e fatores de substituição/representação como o estadiamento T4 e o tipo Difuso da classificação de Lauren podem melhorar a acuidade do estadiamento N.-------------- ABSTRACT: Recent innovations in medical sectional imaging have allowed a major role of multi-detector computed tomography (MDCT) in staging of gastric adenocarcinoma (GA). The purpose of this study was to evaluate the accuracy of this technique in depth of mural invasion (T) and nodal (N) staging of GA and to evaluate prognostic factors as surrogate factors to improve such accuracy. Sixty nine patients operated to GA between January 2010 and July 2012 that underwent Computed Tomography, the majority through Multidetector Computed Tomography (MDCT) with gastric distention, were staged retrospectively by three imagiologists with state-of-the-art criteria and surrogate prognostic factors were analyzed for less accurate stages. MDCT T-staging was 66,7 % accurate with a sensibility of 92 % and there was a 49 % accuracy, 40,9 % sensibility and 64 % specificity for N Staging. Using a surrogate factor of T4/N2 diagnostic staging to change diagnostic MDCT N2 disease to N3A disease would increase accuracy of N staging to 59% and sensibility to 58,1% and would decrease specificity to 61,5 %, although that change was not statistically significant (Fisher´s Exact Test 0,159)In conclusion the accuracy of a simple hydro-MDCT technique in T and N staging of GA is in the range of values cited in the literature and surrogate factors as diagnostic T4 disease and diffuse type of Lauren´s Classification may improve the accuracy of N staging.

Ground truth determination for segmentation of tomographic volumes using interpolation

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Role of sympathetic innervation in obesity

Part of the results presented in this thesis were published in the following reference (DOI 10.1016/j.cell.2015.08.055): Wenwen Zeng*, Roksana M. Pirzgalska*, Mafalda M.A. Pereira, Nadiya Kubasova, Andreia Barateiro, Elsa Seixas, Yi-Hsueh Lu, Albina Kozlova, Henning Voss, Gabriel G. Martins, Jeffrey M. Friedman and Ana I. Domingos. Sympathetic Neuro-adipose Connections Mediate Leptin-Driven Lipolysis. Cell 163, 84-94 (2015). The work was also presented through poster presentations at iMED Conference 6.0 (Lisbon, 2014), Sociedade Portuguesa de Bioquímica Meeting (Coimbra, 2014) and Sociedade Portuguesa de Neurociências Meeting (Póvoa de Varzim, 2015).

Electro-Optical/Infrared sensor turret integration on an aircraft - structural im-pact on LOCKHEED MARTIN C-130H and design methodology

The growing need to patrol and survey large maritime and terrestrial areas increased the need to integrate external sensors on aircraft in order to accomplish those patrols at increasingly higher altitudes, longer range and not depending upon vehicle type. The main focus of this work is to elaborate a practical, simple, effective and efficient methodology for the aircraft modification procedure resulting from the integration of an Elec-tro-Optical/Infra-Red (EO/IR) turret through a support structure. The importance of the devel-opment of a good methodology relies on the correct management of project variables as time, available resources and project complexity. The key is to deliver a proper tool for a project de-sign team that will be used to create a solution that fulfils all technical, non-technical and certi-fication requirements present in this field of transportation. The created methodology is inde-pendent of two main inputs: sensor model and aircraft model definition, and therefore it is in-tended to deliver the results for different projects besides the one that was presented in this work as a case study. This particular case study presents the development of a structure support for FLIR STAR SAPHIRE III turret integration on the front lower fuselage bulkhead (radome) of the LOCKHEED MARTIN C-130 H. Development of the case study focuses on the study of local structural analysis through the use of Finite Element Method (FEM). Development of this Dissertation resulted in a cooperation between Faculty of Science and Technology - Universidade Nova de Lisboa and the company OGMA - Indústria Aeronáutica de Portugal