L’IRM cardiaque a une capacité unique d’étudier le remodelage ventriculaire gauche (VG) après infarctus du myocarde. Les objectifs principaux de ce travail étaient de caractériser le tissue de l’infarctus par IRM et d’évaluer les facteurs associés au remodelage du VG. Nous avons étudié prospectivement 114 patients présentant un premier infarctus du myocarde avec sus-décalage du segment ST et ayant subi une angioplastie primaire. Des IRM cardiaques ont été réalisées dans les 2 à 4 jours et à 6 mois suivant la revascularisation. Premièrement, nous avons réalisé une analyse comparative de différentes méthodes de segmentation de l’infarctus sur l’imagerie de rehaussement tardive (RT). Deuxièmement, nous avons étudié l’évolution des différentes composantes de la zone RT au cours des six mois, et observé que la réduction de la zone RT (33,8%) était représentée par l’extension de la zone grise initiale. Troisièmement, nous avons évalué le rôle clinique de la zone grise. Elle s’est révélée protectrice vis-à-vis du remodelage délétère. Quatrièmement, nous avons étudié l’influence de l’obstruction microvasculaire (OMV) sur le remodelage local du VG. Différents motifs ont été observés entre les patients atteints de l’OMV et ceux ne présentant pas d’OMV: un rétrécissement uniforme à travers le VG chez les patients sans OMV lorsque les sujets avec OMV présentaient une dilatation globale significative, ainsi qu’une dilatation plus importante dans les régions atteint d’OMV / Cardiac MRI (CMR) has the unique ability to study left ventricular remodeling after myocardial infarction. The main objectives of this work were to characterize infarct tissue by CMR and to evaluate factors associated with LV remodeling. We prospectively studied 114 patients with a first ST-segment elevation myocardial infarction (STEMI) undergoing primary angioplasty. CMR was performed within 2-4 days and at 6 months after the revascularization. First, we compared different methods for the segmentation of myocardial infarcts on late gadolinium enhancement (LGE) imaging. Second, we described the evolution of different components of LGE area during 6 months. We found that the decrease of LGE area (33.8%) matched the extent of initial gray zone. Third, we studied the clinical role of gray zone. The gray zone was found to be a protective factor for adverse remodeling. Fourth, we studied the influence of microvascular obstruction (MVO) on local LV remodeling and observed distinct remodeling patterns in patients with and without MVO: equally-distributed shrinkage throughout the LV cavity in patients without MVO whereas significant dilation occurring in those with MVO, tending to be greater in myocardial regions containing MVO

Submitted by Aline Batista (alinehb.ufpel@gmail.com) on 2017-08-16T14:21:20Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) José_Henrique_Nunes_Flores_Modelagem_matemática_da_perda_de_carga_em_emissores_integrados_a_tubulação_de_irrigação_localizada.pdf: 4719317 bytes, checksum: b86c8f8b440b56d663a03abb04efaf4f (MD5) / Made available in DSpace on 2017-08-16T14:21:20Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) José_Henrique_Nunes_Flores_Modelagem_matemática_da_perda_de_carga_em_emissores_integrados_a_tubulação_de_irrigação_localizada.pdf: 4719317 bytes, checksum: b86c8f8b440b56d663a03abb04efaf4f (MD5) Previous issue date: 2017-02-20 / Sem bolsa / Os objetivos deste trabalho foram: (i) Determinar a perda de carga em função da geometria dos emissores, bem como desenvolver uma relação entre a perda de carga localizada, causada pela inserção do emissor, e as características geométricas da tubulação, mediante a utilização do índice de obstrução, para tubogotejadores com emissores integrados do tipo pastilha; e (ii) Gerar um modelo semiteórico, para estimativa da perda de carga localizada no emissor, causada por sua inserção dentro da tubulação, para tubos emissores integrados do tipo pastilha. Para isso, utilizou-se uma bancada experimental desenvolvida para controle do sistema, e obtenção das variáveis pertinentes ao estudo (vazão, temperatura e perda de carga total no tubo emissor). Obteve-se então, através da utilização da equação da continuidade, a velocidade de escoamento. A partir da diferença da perda de carga total no tubo emissor do valor obtido com o cálculo da perda de carga continua na tubulação, obteve-se a perda de carga localizada causada pela inserção do emissor. Através de um projetor ótico de perfil, foram determinadas as características geométricas dos tubos emissores (áreas de seção transversal e perímetros molhados). Obteve-se, a partir da perda de carga localizada no emissor e da carga cinética, o coeficiente k, e gerou-se um modelo para sua estimativa baseado no índice de obstrução. Desenvolveu-se um modelo semiteórico para estimativa da perda de carga no emissor, a partir do Teorema de Bélanger, levando em consideração as características geométricas da tubulação. Os emissores escolhidos para este estudo são: (a) AZUD Premier Line PC; (b) Naan Dan Jain Amnon Drip AC; e (c) Rain Bird XF-SDI. Os resultados permitiram inferir que a perda de carga total no tubo emissor e a perda de carga localizada no emissor apresentaram relação potencial com a vazão. As razões de obstrução dos emissores foram 0,62, 0,68, e 0,65, e os índices de obstrução 0,37, 0,22, e 0,28, para os emissores AZUD Premier Line PC, Naan Dan Jain Amnon Drip AC, e Rain Bird XF-SDI, respectivamente. Já os coeficientes k foram, respectivamente, 1,03, 1,07, e 0,86, para os emissores AZUD Premier Line PC, Naan Dan Jain Amnon Drip AC e Rain Bird XF-SDI. O modelo potencial correlacionando o coeficiente k com o índice de obstrução, foi k=1,66 IO0,413. Em relação ao modelo semiteórico proposto, houve superestimava em 9% e 2%, para os emissores AZUD Premier Line PC e Rain Bird XF-SDI, respectivamente, e subestimativa em 34% para o emissor Naan Dan Jain Amnon Drip AC, apresentando ajuste considerado muito bom, através do índice c, para os três emissores estudados. Conclui-se que cada emissor apresentou um valor para o coeficiente k, existindo correlação com a geometria do tubo emissor, e que o modelo semiteórico proposto, pode ser utilizado para emissores de geometria semelhantes ao AZUD Premier Line PC e Rain Bird XFSDI. / The objectives of this work was: (i) To determine the variability of the head loss as a function of the geometry of the emitters, as well as to develop a relation between the local head loss caused by the emitter insertion and the geometric characteristics of the emitting pipe, using the obstruction index, for emitting pipes with non-coaxial emitters; and (ii) Generate a semi-analytical model to estimate the local head loos in the emitter, caused by its insertion into the pipeline, for emitting pipes with non-coaxial emitters. For this, an experimental bench was developed to control the system and obtain the variables pertinent to the study (flow, temperature and total head loss in the emitter pipe). Then, through the use of the continuity equation, the flow velocity was obtained. From the difference of the total head loss in the emitter pipe and the value obtained with the calculation of the continuous head loss in the pipeline, the local head loss caused by the insertion of the emitter was obtained. The geometric characteristics of the emitting tubes (cross-sectional areas and wetted perimeters) were determined through an optical profile projector. The k coefficient was obtained from the local head loss in the emitter and kinetic energy, and a model was generated for its estimation based on the obstruction index. A semi-analytical model was developed to estimate the head loss in the emitter from the Bélanger Theorem, taking into account the geometric characteristics of the pipe. The emitters chosen for this study are: (a) AZUD Premier Line PC; (b) Naan Dan Jain Amnon Drip AC; And (c) Rain Bird XF-SDI. The results allowed to infer that the total head loss in the emitter pipe and the local head loss in the emitter presented a potential relation with the flow rate. Emitter obstruction ratio were 0.62, 0.68, and 0.65, and obstruction index was 0.37, 0.22, and 0.28 for the emitters AZUD Premier Line PC, Naan Dan Jain Amnon Drip AC, and Rain Bird XFSDI, respectively. The k coefficients were 1.03, 1.07 and 0.86, respectively, for the AZUD Premier Line PC, Naan Dan Jain Amnon Drip AC and Rain Bird XF-SDI emitters respectively. The potential model correlating the k coefficient with the obstruction index was k=1,66 OI0,413. In relation to the proposed semi-analytical model, there was a 9% and 2% overestimation of the AZUD Premier Line PC and Rain Bird XF-SDI emitters, respectively, and a 34% underestimation by Naan Dan Jain Amnon Drip AC, but presenting an adjustment considered very good, through the index c, for the three emitters studied. It is concluded that each emitter presented a value for the k coefficient, there being a correlation with the geometry of the emitter tube, and that the proposed semi-analytical model can be used for geometric emitters similar to AZUD Premier Line PC and Rain Bird XF-SDI.

Nosso objetivo neste trabalho é estudar a obstrução de Euler de uma função, este conceito foi definido por J.-P. Brasselet, D. Massey, A. J. Parameswaran e J. Seade, e generaliza dois conceitos importantes, a obstrução de Euler definida por R. D. MacPherson assim como o número de Milnor de uma função. O resultado principal deste trabalho mostra a relação existente entre a obstrução de Euler e a obstrução de Euler de uma função / Our goal in this work is to study the Euler obstruction of a function, this concept was defined by J.-P. Brasselet, D. Massey, A. J. Parameswaran and J. Seade, and it generalizes two important concepts, the Euler obstruction defined by R. D. MacPherson and the Milnor number of a function. The main result of this study shows the relation between the Euler obstruction and the Euler obstruction of a function

Au décours d'une première embolie pulmonaire (EP), certains patients présentent un syndrome post EP : un tiers des patients ont une obstruction persistante de la vascularisation pulmonaire, associée à la persistance d'une dyspnée et une limitation des performances à l'effort. Certains patients présenteront une récidive d'EP ou, plus rarement, une hypertension pulmonaire, dont les séquelles perfusionnelles sont un critère diagnostique indispensable. Le rôle et la physiopathologie des séquelles perfusionnelles au cours du syndrome post EP est incomprise. Ce travail a mis en évidence l'existence d'un risque majoré de récidive d'EP (odds ratio 1,9) chez les patients présentant des séquelles perfusionnelles >10% à la vascularisation pulmonaire. L'analyse des propriétés fonctionnelles du fibrinogène purifié à partir du plasma de patients suivis pour une première EP améliore la prédiction de séquelles perfusionnelles confirmant le rôle clé de celui-ci dans la physiopathologie de la maladie. Ainsi, une forte proportion de chaine Bβ porteuse d'un seul résidu acide sialique majore le risque de séquelles. L'étude des cellules endothéliales circulantes à la phase aigüe et après une EP montre que les patients qui développeront des séquelles mobilisent peu de cellules endothéliales, témoignant d'une forte altération des processus de réparation de l'endothélium pulmonaire. L'interaction de la fibrine avec les progéniteurs endothéliaux dans cette anomalie de la régulation est possible : les progéniteurs expriment le récepteur VLDLr dont l'épitope β15-42 de la fibrine est un ligand impliqué dans la régulation du cycle cellulaire et l'inhibition de l'angiogenèse. / Pulmonary vascular sequels after pulmonary embolism: prognosis, prediction and physiopathologyAbstract: Post Pulmonary Embolism (PE) syndrome is not rare after PE: one third of the patients presents residual pulmonary vascular obstruction (RPVO) traducing sequels associated with increased dyspnea and impaired exercise capacity. Some of these patients will suffer PE recurrence or, more rarely, chronic thromboembolic pulmonary hypertension, whose one the diagnosis criteria is persistent perfusion defect. Prognosis value and mechanisms underlying vascular sequels are still unclear. The present work shows that RPVO > 10% after a first PE is associated with an increased risk for venous thromboembolism recurrence (odds ratio 1.9). Secondly, fibrinogen properties were investigated in PE patients. Patients with RPVO >10% presented more monosialiated Bβchain form. Prediction models for RPVO that include fibrinogen analysis were more accurate than those without fibrinogen data; This results highlights the key role of fibrin in the pathophysiology of chronic venous thromboembolism. Interestingly, the present work shows that patient who will present RPVO had an impaired endothelial cells mobilization. Compared to patients without RPVO, patients with RPVO had lower circulating endothelial cells at the acute phase of PE. This endothelial dysfunction is probably triggered by endothelial progenitors that expressed the very low density lipoprotein receptor (VLDLr), implicated in the inhibition of angiogenesis and able to bind the β15-42 N terminal sequence of the fibrin Bβ chain.

No description available.

Peritoneal adhesions occur in up to 93% of adults after peritoneal trauma during surgery. Most adhesions are asymptomatic but can cause female infertility, small bowel obstruction (SBO) and chronic abdominal pain. Adhesion prophylaxis is needed to reduce the significant morbidity and increased health care costs resulting from peritoneal adhesions. This thesis aims to establish a relevant and reproducible experimental adhesion model to simultaneously study the healing processs and adhesion formation and later to examine whether carbazate-activated polyvinyl alcohol (PVAC), an aldehyde-carbonyl scavenger, can reduce adhesion formation or not; and, in a long-term follow-up, to investigate the incidence of and identify risk factors for adhesive SBO requiring surgical treatment after laparotomy during infancy and to survey the prevalence of self-reported chronic abdominal pain and female infertility. Male Sprague-Dawley rats were subjected to laparotomy, cecal abrasion, and construction of a small bowel anastomosis and examined at various time points after surgery. Early elevation of IL-6, IL-1β and TNF-α concentrations in peritoneal fluid but not in plasma correlate to adhesion formation in this rodent adhesion model, indicating that anti-adhesion treatment should be early, local and not systemic. The animals were treated with either peritoneal instillation of PVAC, or the anastomosis was sutured with PVAC-impregnated resorbable polyglactin sutures. At day 7, bursting pressure of the anastomosis was measured and adhesions were blindly evaluated using Kennedy- and Nair scoring systems. PVAC-impregnated sutures reduced adhesion formation without reducing bursting pressure. Infants who underwent laparotomy between 1976 and 2011 were identified (n=1185) and 898 patients were included with a median follow-up time of 14.7 (range 0.0-36.0) years. The median age at first laparotomy was 6 (range 1.0-365.0) days. There were 113 patients (12.6%) with adhesive SBO, with the highest incidence found in patients with Hirschsprung’s disease (19 of 65, 29%), malrotation (13 of 45, 29%), intestinal atresia (11 of 40, 28%) and necrotizing enterocolitis (16 of 64, 25%). Lengthy duration of surgery (hazard ratio (HR) 1.25, 95% CI, 1.07 to 1.45), stoma formation (HR 1.72, 1.15 to 2.56) and postoperative complications (HR 1.81, 1.12 to 2.92) were independent risk factors. Chronic abdominal pain was reported in 180 (24.0%) of 750 patients, and 17 (13.8%) of 123 women reported infertility. The morbidity after laparotomy in neonates and infants is high. Awareness of the risk factors may promote changes in surgical practice.

In this thesis, we study the Hasse principle for curves and K3 surfaces. We give several sufficient conditions under which the Brauer-Manin obstruction is the only obstruction to the Hasse principle for curves and K3 surfaces. Using these sufficient conditions, we construct several infinite families of curves and K3 surfaces such that these families are counterexamples to the Hasse principle that are explained by the Brauer-Manin obstruction.

Let Knots be the abelian monoid of isotopy classes of knots S1 ⊂ S3 under connected sum, and let C be the topological knot concordance group of knots modulo slice knots. Cochran-Orr-Teichner [COT03] defined a filtration of C: C ⊃ F(0) ⊃ F(0.5) ⊃ F(1) ⊃ F(1.5) ⊃ F(2) ⊃ . . .The quotient C/F(0.5) is isomorphic to Levine’s algebraic concordance group AC1 [Lev69]; F(0.5) is the algebraically slice knots. The quotient C/F(1.5) contains all metabelian concordance obstructions. The Cochran-Orr-Teichner (1.5)-level two stage obstructions map the concordance class of a knot to a pointed set (COT (C/1.5),U). We define an abelian monoid of chain complexes P, with a monoid homomorphism Knots → P. We then define an algebraic concordance equivalence relation on P and therefore a group AC2 := P/ ~, our second order algebraic knot concordance group. The results of this thesis can be summarised in the following diagram: . That is, we define a group homomorphism C → AC2 which factors through C/F(1.5). We can extract the two stage Cochran-Orr-Teichner obstruction theory from AC2: the dotted arrows are morphisms of pointed sets. Our second order algebraic knot concordance group AC2 is a single stage obstruction group.

The main results of this dissertation show evidence supporting the Successive Surface Scaffolding Conjecture. This is a new conjecture that, if true, guarantees the existence of all the wye-delta-order minimal obstructions of a surface S as subgraphs of the irreducible triangulations of the surface S with a crosscap added. A new data structure, i.e. an augmented rotation system, is presented and used to create an exponential-time algorithm for embedding graphs in any surface with a constant-time check of the change in genus when inserting an edge. A depiction is a new formal definition for representing an embedding graphically, and it is shown that more than one depiction can be given for nonplanar embeddings, and that sometimes two depictions for the same embedding can be drastically different from each other. An algorithm for finding the essential cycles of an embedding is given, and is used to confirm for the projective-plane obstructions, a theorem that shows any embedding of an obstruction must have every edge in an essential cycle. Obstructions of a general surface S that are minor-minimal and not double-wye-delta-minimal are shown to each have an embedding on the surface S with a crosscap added. Finally, open questions for further research are presented. / Graduate

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.