Aspiration of gastric content and delayed or failed intubation are the leading causes of anesthesia-related mortality and morbidity. In the recovery period, airway obstruction with subsequent hypoxia is a relatively common cause of morbidity, and is highly associated to the amount of opioids administered, especially in obese patients. The overall aim of this thesis was to study these risk factors for airway complications and postoperative hypoxia in obese patients, and to evaluate possible strategies for their prevention. In Study I, intubation times and incidence of failed intubation in obese patients were compared between direct laryngoscopy and videolaryngoscopy with the Stortz® C-MAC™. In Studies II and III, the effect of esmolol vs. remifentanil on the esophageal junction, and the possible analgesic properties of low-dose esmolol vs. placebo were evaluated using high-resolution manometry and the cold pressor test, respectively. Finally, in Study IV, the possible opioid-sparing effect of esmolol after laparoscopic gastric bypass surgery was evaluated. The use of videlaryngoscopy did not shorten intubation times, however appeared to reduce the incidence of failed intubation. Our results also show that esmolol has a favorable profile, compared to remifentanil, with regard to the protection against passive regurgitation and aspiration of gastric content. No analgesic effect of low-dose esmolol was however demonstrated. The intraoperative administration of esmolol instead of remifentanil also did not reduce the requirement of morphine for treatment of post-operative pain. The use of Stortz® C-MAC™ may be recommended for intubation of obese patients. Further studies are however required to clarify the possible role of esmolol in anesthesia.

Este estudo tem por escopo analisar o conceito das cláusulas de tax sparing e matching credit, os principais argumentos favoráveis e contrários à utilização desses mecanismos e as hipóteses em que tais cláusulas são adotadas, nos âmbitos nacional e internacional. Sabe-se que, em um primeiro momento, a Organização para a Cooperação e Desenvolvimento Econômico (OCDE) chegou a recomendar a utilização das cláusulas de tax sparing nos acordos de bitributação celebrados entre países com graus diferentes de desenvolvimento econômico, como uma forma de atrair investimentos para os países menos desenvolvidos. No entanto, em relatório publicado em 1998, denominado Tax sparing: a reconsideration, a OCDE reviu sua posição inicial sobre o assunto, passando então a desencorajar o uso dessas cláusulas por seus países membros, através de diversas críticas e questionamentos acerca de sua adoção. O Brasil, por sua vez, desde os primeiros acordos de bitributação celebrados, nos primórdios da década de 1960, tem firmado a política de sempre negociar cláusulas de tax sparing e matching credit, especialmente nos acordos celebrados com países desenvolvidos. Considerando-se tal cenário, pretende-se, com o presente trabalho, estudar as cláusulas de tax sparing e matching credit de forma profunda, de modo a oferecer subsídios para um adequado enfrentamento da questão em futuras negociações de acordos de bitributação pelo País. / The purpose of this study is to analyze the concept of tax sparing and matching credit clauses, the main arguments for and against the use of these mechanisms and the circumstances in which such clauses are adopted, nationally and internationally. It is known that, at first, the Organisation for Economic Co-operation and Development (OECD) used to recommend the inclusion of tax sparing clauses in double taxation conventions concluded between countries with different levels of economic development, as a way of attracting investments for less developed countries. However, the OECD revised its initial position on the subject in a report published in 1998, called \"Tax sparing: a reconsideration\", discouraging the use of such clauses by its member countries through various criticisms and questions about their adoption. In its turn, since the first double taxation agreements concluded in the early 1960s the Brazilian policy regarding the matter has always been to negotiate tax sparing and matching credit clauses, especially in conventions with developed countries. Given such a scenario, this paper aims at studying tax sparing and matching credit clauses deeply, in order to provide devices for an accurate understanding of the issue in future negotiations of double taxation conventions by the Country.

Prostatectomy, surgical resection of the whole prostate is a common treatment for high- risk prostate cancer. Common side effects include long-time urinary and or erectile dysfunction due to damage inflicted to periprostatic nerves. The aim of this study was to identify an optimal magnetic resonance diffusion tensor imaging protocol for visualization and quantification of these nerves, as pre-surgery visualization may help nerve-sparing surgery. Both scanner filter, parameters for accelerated scan techniques, diffusion-related acquisition parameters and post- processing tractography parameters were investigated. Seven healthy volunteers were scanned with a state-of-art 3 T MRI scanner with varying protocol parameters. Diffusion data were processed and analysed using Matlab and Explore DTI. The resulting protocol recommendation included a normalized scanner filter, a parallel imaging acceleration factor of 2, partial Fourier sampling of 6/8, a right-left phase encoding direction, a b-value of 600 s/mm2, monopolar gradient polarity with applied eddy current correction, four acquisitions of 12 diffusion- sensitizing gradient directions, and a reverse phase encoding approach for correction of geometrical image distortions induced by static field inhomogeneity. For post-processing tractography, the recommended parameters were a lower limit for fractional anisotropy of 0.05, a minimum tract length of 3 centimetres and a maximum turning angle between voxels of 60 degrees. The limited parameter range that was tested and the low number of volunteers can be regarded as limitations to this study. Future work should address these issues. Furthermore, feasibility of periprostatic nerve tracking with the optimized protocol should be tested in a patient study.

Aortic valve-sparing procedures treating patients with aortic root aneurysm with or without aortic insufficiency and patients with ascending aortic aneurysm and aortic insufficiency are no longer experimental and unproven procedures. A successful aortic valve-sparing or repair operation aims not only to correct the failing part of the aortic root but also to restore the intro- and the inter-component relationship of the aortic root elements to optimal dimensions and relations. The avoidance of anticoagulation therapy and prosthesis-related complications makes aortic valve repair a tempting procedure. Considering the increasing rate of cusp repair reported in scientific literature, conservative aortic valve surgery seems to be developing into aortic valve repair surgery. This Dissertation Theses are devoted to the study of some specific technical aspects of aortic root sparing surgery, namely to the study of structural changes occurring in cryopreserved human aortic root allografts and the reproducibility of Coroneo ring implantation procedure. The Introduction of these Dissertation Theses deals with the general review of aortic valve- sparing operations in the light of the historical aspects of used surgical technique, dynamic anatomy and the current situation. One part of the Introduction is...

Résumé Introduction L’efficacité de la mastectomie prophylactique est bien démontrée. La mastectomie NSM (nipple-sparing mastectomy) peut potentiellement améliorer les résultats esthétiques, mais elle n’est pas pratiquée d’emblée en raison de doutes face à sa sécurité oncologique. Objectif Évaluer la faisabilité et la sécurité oncologique de la NSM dans un contexte prophylactique ainsi que les résultats esthétiques et la satisfaction des patientes. Méthodologie Une étude rétrospective fut conduite chez toutes les femmes ayant subi une mastectomie prophylactique suivie d’une reconstruction mammaire immédiate au centre hospitalier de l’Université de Montréal (CHUM) entre1997 et 2008. Les données concernant les facteurs de risque de cancer, les complications post-opératoires et les incidences de cancer furent notées. La satisfaction des patientes était évaluée par questionnaire. Deux chirurgiens ont évalué les résultats esthétiques sur des photos. Résultats Soixante et onze patientes ont subi 86 mastectomies prophylactiques, dont 21 NSM et 65 SSM (skin-sparing mastectomy). Suivant une SSM, 34 CAM (complexe aréolo- mamelonaire) furent reconstruits. Une nécrose totale s’est produite dans 2 CAM préservés et dans 2 CAM reconstruits. Le taux général de complications était significativement plus élevé parmi les CAM reconstruits. La satisfaction des patientes quant à l’apparence du CAM était significativement plus élevée dans le groupe NSM et les résultats esthétiques, meilleurs. Avec un temps de suivi moyen de 50 mois, aucune incidence au niveau du CAM n’est survenue. i Conclusion Les NSM offrent de meilleures résultats, n’augmentent pas les complications post- opératoire et semblent sécuritaires au plan oncologique. / Introduction The efficiency of prophylactic mastectomy is well acknowledged. Nipple sparing mastectomy (NSM) can potentially improve cosmetic results, but it is not the current practice because of doubts regarding its oncological safety. Objectives To evaluate NSM’s feasibility and oncological safety in a prophylactic setting, as well as aesthetic results and patient satisfaction. Methods A retrospective study was conducted on every women that underwent prophylacitc mastectomy followed by immediate breast reconstruction in the centre hospitalier de l’Université de Montréal (CHUM) between 1997 and 2008. Data regarding cancer risk factors, post operative complication and cancer incidence were compiled. Patient satisfaction was evaluated using a questionnaire and two plastic surgeons rated the aesthetic results on photos. Results Seventy-one patients underwent 21 NSM et 65 skin-sparing mastectomies (SSM) for a total of 86 prophylactic procedures. Following SSM, 34 nipple areolar-complexes (NAC) were reconstructed. Necrosis was noted in 2 preserved NAC and in 2 reconstructed NAC. The overall complication rate was superior among the reconstructed NAC. Patient satisfaction regarding NAC appearance was significantly higher within the preserved NAC group and the aesthetic results were evaluated as better. With a mean follow-up time of 50 months, no incidence was noted in the NAC area. iii Conclusion NSM offer superior aesthetic results, do not increase post-operative complications and appear the be oncologicaly safe.

Résumé Introduction L’efficacité de la mastectomie prophylactique est bien démontrée. La mastectomie NSM (nipple-sparing mastectomy) peut potentiellement améliorer les résultats esthétiques, mais elle n’est pas pratiquée d’emblée en raison de doutes face à sa sécurité oncologique. Objectif Évaluer la faisabilité et la sécurité oncologique de la NSM dans un contexte prophylactique ainsi que les résultats esthétiques et la satisfaction des patientes. Méthodologie Une étude rétrospective fut conduite chez toutes les femmes ayant subi une mastectomie prophylactique suivie d’une reconstruction mammaire immédiate au centre hospitalier de l’Université de Montréal (CHUM) entre1997 et 2008. Les données concernant les facteurs de risque de cancer, les complications post-opératoires et les incidences de cancer furent notées. La satisfaction des patientes était évaluée par questionnaire. Deux chirurgiens ont évalué les résultats esthétiques sur des photos. Résultats Soixante et onze patientes ont subi 86 mastectomies prophylactiques, dont 21 NSM et 65 SSM (skin-sparing mastectomy). Suivant une SSM, 34 CAM (complexe aréolo- mamelonaire) furent reconstruits. Une nécrose totale s’est produite dans 2 CAM préservés et dans 2 CAM reconstruits. Le taux général de complications était significativement plus élevé parmi les CAM reconstruits. La satisfaction des patientes quant à l’apparence du CAM était significativement plus élevée dans le groupe NSM et les résultats esthétiques, meilleurs. Avec un temps de suivi moyen de 50 mois, aucune incidence au niveau du CAM n’est survenue. i Conclusion Les NSM offrent de meilleures résultats, n’augmentent pas les complications post- opératoire et semblent sécuritaires au plan oncologique. / Introduction The efficiency of prophylactic mastectomy is well acknowledged. Nipple sparing mastectomy (NSM) can potentially improve cosmetic results, but it is not the current practice because of doubts regarding its oncological safety. Objectives To evaluate NSM’s feasibility and oncological safety in a prophylactic setting, as well as aesthetic results and patient satisfaction. Methods A retrospective study was conducted on every women that underwent prophylacitc mastectomy followed by immediate breast reconstruction in the centre hospitalier de l’Université de Montréal (CHUM) between 1997 and 2008. Data regarding cancer risk factors, post operative complication and cancer incidence were compiled. Patient satisfaction was evaluated using a questionnaire and two plastic surgeons rated the aesthetic results on photos. Results Seventy-one patients underwent 21 NSM et 65 skin-sparing mastectomies (SSM) for a total of 86 prophylactic procedures. Following SSM, 34 nipple areolar-complexes (NAC) were reconstructed. Necrosis was noted in 2 preserved NAC and in 2 reconstructed NAC. The overall complication rate was superior among the reconstructed NAC. Patient satisfaction regarding NAC appearance was significantly higher within the preserved NAC group and the aesthetic results were evaluated as better. With a mean follow-up time of 50 months, no incidence was noted in the NAC area. iii Conclusion NSM offer superior aesthetic results, do not increase post-operative complications and appear the be oncologicaly safe.

This master’s thesis studies the problems of high temperatures on cement concretes, their following diagnostics from pre-treatment to rehabilitation, the emphasis was on the use of high-speed water jet. In the experimental part of the design of a concrete composition with basalt aggregate. Were reviewed the physico-mechanical properties after thermal loading. The influence of pressure water jet on the thermal load on concrete, pull-off test, the volume of the removed concrete with a strength evaluation and comparison.

The objective of this diploma thesis is to state the influence of porosity, DAS and shape factor on mechanical characteristics for the cast transmission cover made in Kovolit Modrice a.s.Which was molten from AlSi9Cu3. It was used an imaging software (Olympus Five) for classification of metallographical structures.

The result of this master’s thesis is acquaintance with the issues of cement concrete resistance to high temperatures. This work describes the processes ongoing in the structure of concrete at extreme thermal loads and analysis of effects of high temperatures on the individual components of reinforced concrete structures is given, then influence of high temperatures and fire on the aggregates, matrix, reinforcement steel and the resulting changes in their properties. In the experimental part is given design of composition of concrete with a higher resistance to high temperatures and subsequent verification of the physico-mechanical properties of sample of concrete after exposure to temperatures at intervals of 200 ° C, 400 ° C, 600 ° C and 900 ° C. In individual recipes were observed changes of volume weight, changes of compressive strength and tensile strength flexural , tensile strength of surface layers and the occurrence of cracks and then were compared the results of thermally loaded and unloaded samples. The benefit in this issue is to evaluate the surface appearance of samples after heat load - study of area of crack and measurement of their width - was used according to the methodology's authors Xing, Hebert, Noumowe a Ledesert given in Cement and Concrete Research. This methodology allows to quantify changes of surface, after temperature load.

Land-use intensification in agroecosystems has led to population declines in many taxonomic groups, especially farmland birds. Two contrasting conservation strategies have therefore been proposed: land sharing (the integration of biodiversity conservation in low-intensity agriculture) and land sparing (the spatial separation of high-yielding agriculture and areas for conservation). Despite the large academic interest in this field, only few studies have taken into account stakeholders’ perspectives of these strategies when assessing conservation implications. We modeled the effects of three land-use scenarios (a business-as-usual, a land-sharing, and a land-sparing scenario), developed together with regional stakeholders, on the habitat area of 13 regionally endangered bird species in the Middle Mulde River Basin (Saxony, Germany). We used random forest models based on environmental variables relating to land-use/cover, climate and soil characteristics, occurrence of linear landscape elements (hedges and tree rows), and distance to water and major roads. Responses to the three land-use scenarios were species-specific, but extensively managed permanent grassland and the density of forest edges were positively associated with the occurrence of most bird species. Overall, the land-sharing scenario provided the largest breeding habitat area: 76% of the species had a significant (p < 0.05) increase in breeding habitat, and none showed a significant decrease. Our findings confirm that balancing the different, often contrasting habitat requirements of multiple species is a key challenge in conservation and landscape management. Land sharing, which local stakeholders identified as the most desirable scenario, is a promising strategy for the conservation of endangered birds in agricultural landscapes like our study region.