by Michael Chi Fai Tong. / "Revised March 2000." / Thesis (M.D.)--Chinese University of Hong Kong, 2000. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

This thesis consists of 3 studies: 1. Determination of the minimal important difference (MID) of the visual analogue scale for dyspnoea (VASD): Determining the MID of the VASD is essential to interpret the results of trials in patients with malignant pleural effusions (MPEs). Patients undergoing a pleural procedure assessed the change in their VASD and the degree of change in their symptoms on a Likert scale. The mean VASD in patients experiencing a ‘small but just worthwhile’ decrease in their symptoms is the MID for the VASD and was found to be 22mm (95% CI 16 - 27mm). 2. Development of a thoracic ultrasound septation score (TUSS): A TUSS is important for objectively assessing the degree of septation within a pleural effusion. An iterative process was used to demonstrate that degree of septation predicts clinical outcome, to identify candidate factors for inclusion in a TUSS and to determine which factors predicted the degree of septation. The final TUSS consisted of an assessment of the degree of homogeneity of septation distribution and number of septations at the most septated area. 3. Effect of an indwelling pleural catheter (IPC) versus standard care for relieving dyspnoea in patients with MPEs: the TIME2 randomised controlled trial (RCT). The objective of this unblinded RCT was to determine whether IPCs are more effective than chest drains and talc pleurodesis at relieving dyspnoea in patients with MPEs. 106 patients were randomised to either IPC or standard care in a 1:1 ratio. The primary outcome was daily VASD over 42 days post intervention. Dyspnoea improved in both groups with no significant difference in mean dyspnoea in the first 42 days (mean score: IPC 25mm (95% CI 19 – 30), standard care 24mm (95% CI 19 – 29)).

Full-coverage or effusion cooling is commonly used in the thermal management of gas turbine combustion systems. The combustor environment is characterised by highly turbulent free-stream conditions and relatively large turbulent length scales. This turbulent flow field is predominantly created by the upstream fuel injector for lean burn systems. In rich burn systems the turbulent flow field is augmented further by the addition of dilution ports. The available evidence suggests that large energetic eddies interact strongly with the injected coolant fluid and may have a significant impact on the film-cooling performance. The desire to create compact low-emission combustion systems with improved specific fuel consumption, has given rise to a desire to reduce the quantity of air used in wall cooling, and has led to the need for improved cooling correlations and validated computational methods. In order to establish a greater understanding of effusion cooling under conditions of very high free-stream turbulence, a new laboratory test facility has been created that is capable of simulating representative combustor flow conditions, and that allows for a systematic investigation of cooling performance over a range of free-stream turbulence conditions (up to 25% intensity, integral length scale-to-coolant hole diameter ratios of 26) and coolant to mainstream density ratios (??_c/??_??? ???2). This thesis describes this new test facility, including the method for generating combustor relevant flow conditions. The hot side film cooling performance of cylindrical and fanned hole effusion has been evaluated in terms of adiabatic film-cooling effectiveness and normalised heat transfer coefficient (HTC) and heat flux reduction (HFR). Infrared thermography was employed to produce spatial resolved surface temperature distributions of the effusion surface. The analysis of this data is supported by fluid temperature field measurements. The interpretation of the data has established the impact of turbulence intensity, integral length scale and density ratio on the mixing processes between free-stream and coolant flows. Elevated levels of free-stream turbulence increase the rate of mixing and degrade the cooling effectiveness at low blowing ratios whereas at high blowing ratios, where the coolant detaches from the surface, a modest increase has been observed under certain conditions; this is due to the turbulent transport of the detached coolant fluid back towards the wall. For angled cylindrical hole injection the impact of density ratio as an independent parameter was found to be relatively weak. Adiabatic effectiveness data gathered at DR's of 1 - 1.4 scaled reasonable well when plotted against momentum flux ratio. This suggests data collected at low DR's can be scaled to engine representative DR's. The investigation of shaped cooling holes found fanned effusion has the potential to dramatically improve film effectiveness. The diffusion of the flow through a fanned exit prevented jet detachment at blowing ratios up to 5, increasing spatially averaged effectiveness by 89%.

Research was conducted on twenty-seven preoperative myringotomy patients to clarify the correlation between tympanometry type and the presence of middle ear effusion. Test results indicate that the relationship between tympanometry and middle ear effusion is dependent on the amount of fluid present. In impacted ears primarily Type B tympanograms were obtained whereas for less than impacted ears all tympanogram types were seen. Also suggested was that a combination of height of the tympanogram and the amount of negative pressure may be diagnostically more important than negative pressure alone as an indicator of effusion. It was recommended that other measures in addition to tympanometry be employed in the diagnosis of middle ear effusion and that further research is needed to achieve optimal use of impedance audiometry.

Numerical simulation is progressively taking importance in the design of an aero- nautical engine. However, concerning the particular case of cooling devices, the high number of sub-millimetric cooling holes is an obstacle for computational sim- ulations. A classical approach goes through the modelling of the effusion cooling by homogenisation. It allows to simulate a full combustor but failsin representing the jet penetration and mixing. A new approach named thickened-hole model was developed during this thesis to overcome this issue. A work on improving the mesh resolution onkey areas thanks to an automatic adaptive method is also presented, leading to a clear breakthrough. In parallel, as the flame tube temperature is a cornerstone for the combustor durability,a low-cost approach is proposed to predict it. To meet the time-constraints of design, it is based on thermal modelling instead of a direct thermal resolution.

Introdução: O acúmulo de líquido na cavidade pleural afeta a dinâmica do sistema respiratório repercutindo no seu comportamento funcional. Contudo, seus efeitos sobre o sono permanecem indefinidos. Objetivos: Determinar a qualidade do sono e o grau de hipoxemia durante a vigília e sono antes e após a toracocentese de alívio em portadores de derrame pleural. Casuística e Métodos: Dentre os pacientes atendidos no grupo de doenças pleurais do HC-FMUSP foram selecionados, de forma consecutiva pacientes clinicamente estáveis com derrame pleural volumoso unilateral no estudo radiológico do tórax. Todos responderam questionários de sono incluindo Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index e Escala de Dispnéia Modificada de Borg. Os pacientes foram submetidos à polissonografia completa e questionários antes e após a punção esvaziadora. Resultados: Foram estudados 19 pacientes, com idade média de 55 ± 18 anos, sendo 11 do sexo masculino. Na presença de líquido pleural, a qualidade objetiva do sono basal não foi satisfatória (PSQI: 9,1 ± 3,5). Após a retirada de 1.624 ± 796 mL houve diminuição significante do índice de dispnéia (Escala Modificada de Borg: 2,3 ± 2,1 vs 0,8 ± 0,9; p < 0,001). As polissonografias pré e pós-toracocentese não demonstraram mudanças no índice apnéia-hipopnéia e no tempo de sono com saturação periférica de oxigênio inferior a 90 %. Houve, após a toracocentese, melhora significativa (p < 0,05) na eficiência do sono e aumento significativo da latência do sono, diminuição da latência do sono e do sono REM e no percentual de sono de estágio 1. Observou-se tendência no aumento do tempo total de sono, no tempo acordado após o início do sono e no percentual de sono REM. A melhora da qualidade do sono não se correlacionou com o volume de líquido pleural retirado, com mudanças no grau de dispnéia ou da SpO2 durante o sono. Conclusões: Pacientes com derrames pleurais volumosos têm qualidade de sono subjetiva e objetivamente insatisfatórias, que melhoram após o esvaziamento da cavidade pleural. Finalmente, não se observou influência da toracocentese no grau de hipoxemia durante a vigília e durante o sono, assim como não houve correlação entre volume de líquido retirado e a dispnéia avaliada pela escala de Borg modificada / Introduction: Large pleural effusion affects pulmonary physiology. However, the impact of pleural effusion on sleep remains unknown. Objectives: To determine the sleep quality and hypoxemia levels during awakeness and sleep before and after therapeutic thoracentesis in patients with pleural effusion. Methods: Among patients of Pleural Diseases Clinic at the Hospital das Clinicas da FMUSP, were recruited clinically stable consecutive patients with large unilateral pleural effusion documented by chest radiograph. All these patients were evaluated by Pittsburgh Sleep Quality Index (PSQI) questionnaire, Epworth Sleepiness Scale (ESS) before polysomnography. Dyspnea Borg scale and full polysomnography were also performed before and after thoracentesis. Results: We studied 19 patients (11 males), age 55 ± 18 years and body mass index 26 ± 5 kg/m2. The baseline quality of sleep was poor (PSQI = 9.1 ± 3.5). The amount of pleural fluid removed was 1624 ± 796 mL and resulted in a significant decrease in dyspnea according to Borg scale (2.3 ± 2.1 vs 0.8 ± 0.9, p < 0.001). The polysomnography before and after thoracentesis showed no significant changes in apnea hypopnea index and sleep time with oxygen saturation (SpO2) < 90%. Significant improvements (p < 0.05) occurred in sleep efficiency, increase in sleep onset, decrease in rapid eye movement (REM) latency from sleep onset and percentage of stage 1 sleep. There was a trend improvement in total sleep time, wake time during sleep period and percentage of REM sleep. However, the improvement in sleep quality was not associated with volume of pleural fluid withdrawn, changes in dyspnea or SpO2 during sleep. Conclusions: Patients with large pleural effusions have poor subjective and objective sleep quality that improves after thoracentesis. Finally, there was no impact of thoracentesis on hypoxemia levels during sleep and awakeness and no relationship was observed between the amount of fluid withdrawn and dyspnea according to Borg scale

Introdução: O acúmulo de líquido na cavidade pleural afeta a dinâmica do sistema respiratório repercutindo no seu comportamento funcional. Contudo, seus efeitos sobre o sono permanecem indefinidos. Objetivos: Determinar a qualidade do sono e o grau de hipoxemia durante a vigília e sono antes e após a toracocentese de alívio em portadores de derrame pleural. Casuística e Métodos: Dentre os pacientes atendidos no grupo de doenças pleurais do HC-FMUSP foram selecionados, de forma consecutiva pacientes clinicamente estáveis com derrame pleural volumoso unilateral no estudo radiológico do tórax. Todos responderam questionários de sono incluindo Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index e Escala de Dispnéia Modificada de Borg. Os pacientes foram submetidos à polissonografia completa e questionários antes e após a punção esvaziadora. Resultados: Foram estudados 19 pacientes, com idade média de 55 ± 18 anos, sendo 11 do sexo masculino. Na presença de líquido pleural, a qualidade objetiva do sono basal não foi satisfatória (PSQI: 9,1 ± 3,5). Após a retirada de 1.624 ± 796 mL houve diminuição significante do índice de dispnéia (Escala Modificada de Borg: 2,3 ± 2,1 vs 0,8 ± 0,9; p < 0,001). As polissonografias pré e pós-toracocentese não demonstraram mudanças no índice apnéia-hipopnéia e no tempo de sono com saturação periférica de oxigênio inferior a 90 %. Houve, após a toracocentese, melhora significativa (p < 0,05) na eficiência do sono e aumento significativo da latência do sono, diminuição da latência do sono e do sono REM e no percentual de sono de estágio 1. Observou-se tendência no aumento do tempo total de sono, no tempo acordado após o início do sono e no percentual de sono REM. A melhora da qualidade do sono não se correlacionou com o volume de líquido pleural retirado, com mudanças no grau de dispnéia ou da SpO2 durante o sono. Conclusões: Pacientes com derrames pleurais volumosos têm qualidade de sono subjetiva e objetivamente insatisfatórias, que melhoram após o esvaziamento da cavidade pleural. Finalmente, não se observou influência da toracocentese no grau de hipoxemia durante a vigília e durante o sono, assim como não houve correlação entre volume de líquido retirado e a dispnéia avaliada pela escala de Borg modificada / Introduction: Large pleural effusion affects pulmonary physiology. However, the impact of pleural effusion on sleep remains unknown. Objectives: To determine the sleep quality and hypoxemia levels during awakeness and sleep before and after therapeutic thoracentesis in patients with pleural effusion. Methods: Among patients of Pleural Diseases Clinic at the Hospital das Clinicas da FMUSP, were recruited clinically stable consecutive patients with large unilateral pleural effusion documented by chest radiograph. All these patients were evaluated by Pittsburgh Sleep Quality Index (PSQI) questionnaire, Epworth Sleepiness Scale (ESS) before polysomnography. Dyspnea Borg scale and full polysomnography were also performed before and after thoracentesis. Results: We studied 19 patients (11 males), age 55 ± 18 years and body mass index 26 ± 5 kg/m2. The baseline quality of sleep was poor (PSQI = 9.1 ± 3.5). The amount of pleural fluid removed was 1624 ± 796 mL and resulted in a significant decrease in dyspnea according to Borg scale (2.3 ± 2.1 vs 0.8 ± 0.9, p < 0.001). The polysomnography before and after thoracentesis showed no significant changes in apnea hypopnea index and sleep time with oxygen saturation (SpO2) < 90%. Significant improvements (p < 0.05) occurred in sleep efficiency, increase in sleep onset, decrease in rapid eye movement (REM) latency from sleep onset and percentage of stage 1 sleep. There was a trend improvement in total sleep time, wake time during sleep period and percentage of REM sleep. However, the improvement in sleep quality was not associated with volume of pleural fluid withdrawn, changes in dyspnea or SpO2 during sleep. Conclusions: Patients with large pleural effusions have poor subjective and objective sleep quality that improves after thoracentesis. Finally, there was no impact of thoracentesis on hypoxemia levels during sleep and awakeness and no relationship was observed between the amount of fluid withdrawn and dyspnea according to Borg scale

Knee osteoarthritis (OA) is a progressive disease and a leading cause of morbidity in older adults, resulting in severe mobility limitations. While the osteoligamentous and neuromuscular systems are altered in knee OA, little data is available to illustrate an association among these systems. The objective of this dissertation was to improve our understanding of how muscle activation patterns during gait are altered across the knee OA severity spectrum and to examine how factors related to the OA process are associated with these alterations. Three independent but related studies were conducted. Muscle activation of the medial and lateral orientations of the gastrocnemii, quadriceps and hamstrings were recorded during gait using surface electromyography for all three studies. Key activation features were identified using principal component analysis. First, participants selected from a large group (n=272) of individuals classified as asymptomatic, ii) moderate ii) severe knee OA were matched for walking velocity. Significant amplitude and temporal activation characteristics were found, supporting that differences among OA severities exist and were not the result of walking velocity only. Secondly, individuals with moderate OA were sub-grouped based on structural severity determined using Kellgren-Lawrence radiographic scores (II-IV) and were compared to a velocity-matched asymptomatic group. Medial gastrocnemius, lateral hamstring and quadriceps amplitudes and temporal patterns were significantly altered by structural severity where significant activation imbalances between the lateral:medial gastrocnemii and hamstrings were found with greater structural impairment (score>II). Thirdly, individuals with moderate OA were prospectively evaluated and divided into knee effusion and no effusion groups, based on a positive bulge test. A significantly higher knee flexion angle during mid-stance, higher quadriceps amplitudes and prolonged hamstrings amplitudes were found when effusion was found. These studies showed that muscle activation patterns during walking were related to i) OA presence and severity based on functional, symptoms and radiographic evidence, ii) structural severity and iii) knee joint effusion. These findings improve our understanding of the interrelationships between alterations in joint structure and function associated with knee OA and muscle activation patterns during gait. These data can contribute to the development of gait-based metrics that can facilitate knee OA diagnosis and monitor progression.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 5 uppsatser.

Techn. University, Diss., 2005--München.