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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Calorimetria indireta x Harris Benedict: determinação, validação e comparação para cálculo da taxa metabólica de repouso em obesos grau III. / Indirect calorimetry x Harris Benedict: determination, validation and comparision to calculate rest metabolic rate in morbidly obese.

Nonino, Carla Barbosa 22 March 2002 (has links)
Vários estudos analisando a taxa de metabolismo de repouso (TMR) contribuíram com equações cuja proposta era estabelecer padrões que pudessem ser genericamente utilizadas para se estimar a TMR. A equação de Harris-Benedict (HB), permanece como o método mais comumente utilizado para estimar a TMR. Porém, em indivíduos obesos o uso de equações preditivas da TMR pode levar a resultados conflitantes. Indivíduos obesos submetidos a dietas hipocalóricas podem apresentar uma diminuição da TMR e do gasto energético total. Isto pode ser a causa da redução na velocidade da perda de peso durante o tratamento. Outros estudos mostram que a TMR, quando corrigida para a massa livre de gordura (MLG), apresenta pouca variabilidade e propõem uma correlação entre MLG e TMR. Porém ainda existem dificuldades em se afirmar ou não se a redução de massa corporal também reduz a TMR. O presente estudo teve como objetivos determinar a TMR de indivíduos com obesidade grau III (IMC > 40 kg/m2) do sexo feminino obtida por meio de calorimetria indireta (CI) e comparar com a TMR estimada por meio da equação de HB utilizando-se peso atual e peso ideal. Relacionar a TMR medida por CI com a composição corporal e validar a relação entre a TMR e a MLG nestes indivíduos antes e após a perda de peso. As pacientes foram internadas na Unidade Metabólica da Divisão de Nutrologia do Departamento de Clínica Médica do HCFMRP-USP, durante um período de 8 semanas. No início e no final do estudo foram realizadas: avaliação nutricional incluindo antropometria, bioimpedância e calorimetria indireta. As pacientes foram submetidas a uma dieta hipocalórica durante a internação. A TMR medida por calorimetria indireta (CI) no início e final do estudo foi de 2540 ± 417 e 1924 ± 275 kcal/dia, respectivamente (p<0,05). Quando calculado pela equação de HB utilizando-se peso atual, os valores encontrados foram 2074 ± 214 e 1941 ± 190 kcal/dia (p<0,05). Utilizando-se o peso ideal a TMR calculada foi de 1343 ± 59 kcal/dia. A TMR medida por CI foi, em média, 18 % maior que a calculada por HB pelo peso atual e 47 % maior que a calculada por HB utilizando-se o peso ideal no início do estudo. No final do estudo estes valores passaram para 1% e 30% respectivamente. Comparando-se a TMR medida por CI e calculada por HB usando peso atual tem-se, no início do estudo uma diferença significante (p<0,05) que não se repete no final do estudo (p>0,05). A TMR, quando corrigida para massa livre de gordura no início e no final do estudo foi de 46 ± 6 e 35 ± 5 kcal/d/MLG (p<0,05) respectivamente e quando corrigida para a gordura corporal (GC) foi de 33 ± 6 e 30 ± 5 kcal/d/GC (p<0,05) respectivamente. Os dados encontrados no presente estudo não permitem afirmar que o uso da equação de HB possa estimar a TMR de maneira confiável em indivíduos obesos grau III do sexo feminino. Porém os dados sugerem que logo após submeter esses indivíduos à dieta hipocalórica, com conseqüente perda de peso a equação de HB se torna confiável para estimar a TMR. Pacientes obesos ingerindo dieta livre deveriam ter a TMR obtida por meio da equação de HB corrigida por um fator de 20% a mais. / Studies analyzing resting energy expenditure (REE) have contributed with equations that were intended to establish a pattern that could be used generally to estimate the REE. Harris Benedict’s (HB) equation remains as the most used in estimating the REE. But in obese subjects, the use of predictive equations can lead to conflicting results. Obese individuals undergoing a hypo caloric diet may have a reduction in the REE and in the total energy expenditure. These are the most probably cause of the slowing on weight loss during the treatment. Some studies show that when the REE is relative to the fat free mass (FFM) there is less variability and their proposal is a correlation between FFM and REE. But it is difficult to confirm if a reduction in total body mass also can diminish the REE. The objective of this study was to define the REE of female subjects with grade III obesity (body mass index (BMI) > 40 kg/m2) using indirect calorimetry (IC) and to compare this REE with the one estimated with HB equation using real body weight and ideal body weight, and try to correlate the REE obtained by IC with the body composition, validating the relation between REE and FFM in these individual before and after weight loss. The patients were under hospital regimen in the Metabolic Unit of the Nutrology Division of the Internal Medicine Department of the HCFMRP-USP, for an 8 weeks period. At the beginning and at the end of the study, nutritional assessment was realized, including anthropometry, bioimpedance and indirect calorimetry. The patients were undergoing a hypo caloric diet during the 8 week period. The REE obtained by indirect calorimetry (IC) at the beginning and at the end of the study was 2540 ± 417 e 1924 ± 275 kcal/day, respectively (p<0,05). When estimated with the HB equation using real weight the values were 2074 ± 214 e 1941 ± 190 kcal/day (p<0,05). Using the ideal weight, the calculated REE was 1343 ± 59 kcal/day. At the beginning of the study, REE obtained by IC was 18 % greater than the REE calculated with HB equation using the real weight and 47 % greater than the one calculated using the ideal body weight. At the end of the study these values changed to 1% e 30% respectively. There is a significant difference (p<0,05) when comparing the REE obtained by IC with the one calculated using the HB equation with real weight at the beginning of the study, but this does not happen at the end of the study (p>0,05). The REE corrected by the FFM at the beginning and at the end of the study was 46 ± 6 e 35 ± 5 kcal/d/FFM (p<0,05) respectively and the REE corrected by the fat mass (FM) was 3 ± 6 e 30 ± 5 kcal/d/FM (p<0,05) respectively. The data found in this study does not allow affirming that the use of HB equation to predict REE in female grade III obese subjects is reliable. But the data suggest that immediately after using a hypo caloric diet, the REE calculated using HB equation and real weight is reliable. When calculating the REE of female grade III obese patients undergoing a free diet using HB equation, the obtained value should be increased in 20 %.
182

Investigating Thermal Transformations of Ligand-Stabilized Gold Nanoparticles: Influence of the Structural Attributes of the Nanoparticle and Its Environment on Thermal Stability

Smith, Beverly 18 August 2015 (has links)
Ligand-stabilized metal nanoparticles (LSNPs) have garnered significant attention for use in applications including sensing, catalysis, and thin film fabrication. Many uses rely on the size-dependent properties of the metal nanoparticle core. Therefore, preservation of nanoparticle core size is of paramount importance. In other uses, the low processing temperatures afforded by metal LSNPs make them attractive as precursors for conductive thin films. In these distinctly different applications, understanding nanoparticle thermal stability is crucial. A key finding of this research is that nanoparticle sintering is dependent upon both core size and ligand functionality. Multi-technique analysis of four types of gold nanoparticles (AuNPs) with different ligand compositions and core sizes illustrates that more volatile ligands reduce the onset temperature for sintering. Also, AuNPs of larger core size with the same ligand composition exhibit lower sintering onset temperatures. Correlation between measurements reveals that only a small amount of ligand loss is necessary to trigger rapid sintering and that ligands are excluded to the surface of the porous gold films. AuNPs with ligand shells composed of two alkanethiols of different chain length and volatility indicate that the onset temperature of sintering can be tuned further through incorporation of a small amount of more volatile alkanethiol into a ligand shell of lower volatility. Mixed LSNPs further reveal that AuNP thermal stability depends upon the ligand shell composition and its intermolecular interactions, which can result in markedly different sintering behavior for different ligand compositions. Long-chain alkanethiol AuNPs sinter after only a small amount of ligand loss, whereas short-chain alkanethiol AuNPs sinter following complete ligand loss and the formation of metastable bare AuNPs. Heated AuNP films prepared with mixed-ligand AuNPs exhibit ligand-dependent differences in film morphology. To probe AuNP thermal stability in 2D-assemblies, self-assembly using larger ‘marker’ nanoparticles enables the study of small 1.5 nm AuNP arrays with successive TEM monitoring throughout ex situ heating. Monitoring images of the same area shows short-range (1-2 nm) nanoparticle migration/coalescence. In contrast to 3D assemblies, AuNP growth occurs at temperatures as low as 60 °C. This dissertation includes previously published and unpublished co-authored material. / 10000-01-01
183

Na,K-ATPase reconstituída em lipossomos de fosfolipídios e colesterol: caracterização biofísica e bioquímica / Na,K-ATPase reconstituted into phospholipids and cholesterol liposomes: biochemical and biophysical characterization.

Yoneda, Juliana Sakamoto 03 March 2010 (has links)
A Na,K-ATPase é uma proteína integral que utiliza a energia derivada da hidrólise do ATP para transportar íons Na+ e K+ através da membrana contra seus gradientes eletroquímicos. É composta por três subunidades, denominadas alfa, beta e gama. Alguns autores defendem que o protômero (alfa-beta) seja a unidade estrutural e funcional da enzima, porém outros consideram que a enzima nativa da membrana funciona como um oligômero, na forma de um dímero (alfa-beta)2. Em estudos com proteínas de membrana, o uso de detergentes é bastante comum para manter a proteína de interesse em um estado funcional após ser retirada da bicamada lipídica, além disso, sabe-se que vários fatores interferem a atividade enzimática da Na,K-ATPase e existem evidências que mostram que a bicamada lipídica, na qual a enzima está inserida, também controla a interação entre os protômeros da proteína e alterações nas suas propriedades biofísicas podem modular a atividade da enzima. O objetivo do trabalho foi verificar o efeito de diferentes razões detergente/proteína na estabilidade da Na,K-ATPase solubilizada e de diferentes microambientes lipídicos na sua atividade, analisando as alterações no comportamento termotrópico da bicamada com a mudança da composição lipídica, observando as alterações da incorporação e recuperação da atividade enzimática quando a proteína foi reconstituída em sistemas miméticos de membrana. Utilizando o espalhamento dinâmico de luz (DLS) foi possível acompanhar o processo de agregação térmica da enzima, fornecendo informações da sua estrutura, bem como avaliar a sua estabilidade quando solubilizada. A desnaturação térmica da Na,K-ATPase também foi avaliada por calorimetria diferencial de varredura (DSC) e verificou-se que é um processo irreversível, e ocorreu entre 50 e 70°C, sendo a soma de três transições. Utilizando DSC, analisou-se ainda o comportamento termotrópico dos sistemas de lipossomos e proteolipossomos constituídos de DPPC, DPPE e colesterol. Para os sistemas vesiculares, na ausência da proteína, foi observado que para o sistema binário de DPPC e DPPE, o aumento da proporção do último lipídio induz uma separação de fase, assim como a presença de colesterol, tanto nos sistemas binários (DPPC:Col e DPPE:Col), quanto no ternário (DPPC:DPPE:Col). Avaliou-se ainda como o microambiente lipídico interfere na incorporação e atividade da Na,K-ATPase. Verificou que diferentes quantidades de colesterol alteram a atividade enzimática, confirmando que este possui um importante papel na modulação da atividade, alterando propriedades da membrana e influenciando na conformação da proteína. / Na,K-ATPase is an enzyme that is intrinsic to the plasma membrane, responsible for the coupled active transport of Na+ and K+ across animal cell membranes. The enzyme consists of alfa, beta and gama subunits. It has been demonstrated that the alfa-beta form of Na,K-ATPase is capable of both ATP hydrolysis and active ion transport, however accumulating evidence suggest that the enzyme normally self-associates as (alfa-beta)2 dimers. In membrane protein research, the most typical use of a detergent is to maintain a target membrane protein in a functional, folded state in the absence of a membrane. Moreover, it is known that several factors influence the enzymatic activity of Na, K-ATPase and there is evidence that the lipid bilayer, in which the enzyme is located, also controls the interaction between protomers and that changes in their biophysical properties can modulate the activity of the enzyme. The objective of this study was to investigate the effect of different detergent/protein ratios on the stability solubilized of Na, K-ATPase and different lipid microenvironments in their activity by analyzing changes in the thermotropic behavior of the bilayer, analysing the incorporation changes and the recovery of enzyme activity when the protein was reconstituted in a membrane mimetic systems. Dynamic light scattering (DLS) was used to monitor the process of thermal aggregation of the enzyme, providing information on their structure and evaluating its stability when solubized. The thermal denaturation of Na, K-ATPase was also evaluated by differential scanning calorimetry (DSC) and it was verified that it is an irreversible process, which occurred between 50 and 70 ° C, being the sum of three transitions. Using DSC, we analyzed the thermotropic behavior of proteolipossomos and liposomes consisting of DPPC, DPPE and cholesterol. For vesicular systems in the absence of the protein, it was observed that for the binary system of DPPC and DPPE, increasing the proportion of the latter induces a lipid phase separation and the presence of cholesterol in both binary systems (DPPC: Col and DPPE: Chol), and in the ternary system (DPPC: DPPE: Chol) it induces a lipid phase separation. It was also evaluated how the lipid microenvironment interferes on the incorporation and activity of Na, K-ATPase. It was found that different amounts of cholesterol alter the enzyme activity, confirming cholesterol has an important role in the modulation of the activity by altering the membrane properties and influencing the protein conformation.
184

Measured metabolic requirement for septic shock patients before and after liberation from mechanical ventilation

Lee, Peggy S. P. January 2015 (has links)
Objectives: Negative energy balance can impair regeneration of the respiratory epithelium and limit the functionality of respiratory muscles, which can prolong mechanical ventilation. The present study sought to quantify and identify deviation in energy requirements of patients with septic shock during and upon liberation from mechanical ventilation. Methods: Patients admitted into intensive care with initial diagnosis of septic shock and mechanical ventilation-dependent were recruited. Their metabolic requirements before and after liberation from mechanical ventilation were measured by indirect calorimetry. Paired t-test was used to examine the variance between the two modes of breathing and Spearman rho correlation coefficient to examine relationship of selected indicators. Results: Thirty-five patients, 20 males and 15 females mean age 69 ±10 years, body height of 1.58 ±0.08 meters, and ideal body weight 59.01 ±7.63 kg were recruited. Median APACHEII score was 22, length of stay in the intensive care was 45 ±65 days and duration on mechanical ventilation was 24 ±25 days. Measured energy expenditure during ventilation was 2090 ±489 kcal∙d-1 upon liberation from ventilation was 1910 ±579 kcal∙d-1, and actual caloric intake was 1148 ±495 kcal∙d-1. Paired-t test showed that measured energy expenditure (p=0.02), actual calories provision and energy expenditure with (p=0.00) and without (p=0.00) ventilator support were all significantly different. Mean carbohydrate oxidation was 0.17 ±0.09 g·min-1 when patients were on mechanical ventilation compared to 0.14 ±0.08 g·min-1 upon liberalization from it, however, the results were not statistically significant. Furthermore, mean lipid oxidation was 0.08 ±0.05 g·min-1 during mechanical ventilation and 0.09±0.07 g·min-1 upon liberalization from it and the mean difference was not statistically significant. Spearman correlation coefficient showed a positive relationship between actual calorie provision and duration of stay in intensive care (r=0.41 and p=0.01) and duration on mechanical ventilation (r=0.55 and p=0.00). Oxygen consumption (r=0.49 and p=0.00) and carbon dioxide production (r=0.4 and p=0.02) were moderately strong and positive during and upon liberation from mechanical ventilation. Correlation between lipid oxidation and oxygen consumption during ventilation (r=0.74, p=0.00) and after ventilation (r=0.82, p=0.00) as well as lipid oxidation and carbon dioxide production during ventilation (r=0.37, p=0.03) and liberation from ventilator (r=0.91, p=0.00) were significantly correlated with each other in grams per minute only. Conclusions: This is a pioneering study to examine energy expenditure and substrate utilization and oxidation within a single cohort of patients. The lower measured energy expenditure upon liberation from mechanical ventilation among critically ill patients could result from positive pressure support from ventilation, the repeated cycle of “rest” and “work” during weaning from ventilators and the asynchronization between self-initiated breathing effort and the ventilatory support. The positive relationship in duration on mechanical ventilation and length of stay with calorie consumption could be longer stay led to more time for progression to reach nutrition targets. . Any discrepancy in energy expenditure and substrate utilization with and without ventilatory support should be monitored. Future studies are important to examine whether matching energy expenditure with energy intake could promote positive clinical outcomes.
185

Síntese, caracterização e estudo do comportamento térmico dos 2-metoxibenzoatos de Mn(II), Co(II), Ni(II), Cu(II) e Zn(II) no estado sólido /

Carvalho, Cláudio Teodoro de. January 2006 (has links)
Orientador: Massao Ionashiro / Banca: João Olimpio Tognolli / Banca: Salvador Claro Neto / Resumo: Carbonatos de Mn(II), Co(II), Ni(II), Cu(II) e Zn(II) foram preparados por adição lenta da solução saturada de hidrogeno carbonato de sódio com gotejamento contínuo às soluções dos respectivos cloretos metálicos, exceto para o cobre, até a total precipitação do íon metálico. Os precipitados foram lavados com água destilada para eliminar os íons cloretos e teste qualitativo com solução de AgNO3/HNO3 foi realizado para confirmar a ausência destes, e após isso, foi mantida em suspensão. Os compostos no estado sólido foram preparados pela mistura dos respectivos carbonatos metálicos com o ácido 2-metoxibenzóico (2-MeO-HBz). A suspensão aquosa foi aquecida lentamente próximo da ebulição até neutralização total dos carbonatos. As soluções resultantes depois de arrefecidas foram mantidas em banho de gelo para recristalizar o ácido em excesso e filtradas. Assim, as soluções aquosas dos metoxibenzoatos metálicos foram concentradas em banho maria e o precipitado seco resultante deste processo colocado em um dessecador contendo cloreto de cálcio. O composto de cobre devido a sua baixa solubilidade foi preparado pela adição lenta com gotejamento contínuo de solução do 2-metoxibenzoato de sódio 0.1 mol L-1 à solução de sulfato de cobre, até a total precipitação do íon cobre e o precipitado lavado com água destilada para eliminação do íon sulfato e teste qualitativo de confirmação realizado com BaCl2 0.1 mol L-1, em seguida filtrada em papel de filtro Whatman 40 e o precipitado após seco foi colocado em dessecador contendo cloreto de cálcio. Os compostos sintetizados foram investigados por meio de espectroscopia de infravermelho, difratometria de raio X pelo método do pó, termogravimetria e análise térmica diferencial simultânea (TG-DTA), termogravimetria, termogravimetria derivada (TG/DTG), calorimetria exploratória diferencial (DSC) e outros métodos de análise. / Abstract: Carbonates of Mn (II), Co (II), Ni (II), Cu (II) and Zn (II) were prepared by adding slowly with continuous stirring saturated sodium hydrogen carbonate solution to the corresponding metal chloride solutions (except copper), until total precipitation of the metal ions. The precipitates were washed with distilled water until elimination of chloride ions (qualitative test with AgNO3/HNO3 solution) and maintained in aqueous suspension. olid state Mn (II), Co (II), Ni (II) and Zn (II) compounds were prepared by mixing the respective metal carbonates with 2-methoxybenzoic acid 99% (2-MeO-HBz) obtained from Aldrich, in slight excess. The aqueous suspension was heated slowly up to near ebullition, until total neutralization of the respective carbonates. The resulting solutions after cooled were maintained in an ice bath to recrystallize the acid in excess and filtered through a Whatman nº 40 filter paper. Thus, the aqueous solutions of the respective metal 2-methoxybenzoates were evaporated in a water bath until near dryness and kept in a desiccator over calcium chloride. The copper compound due to its low solubility was prepared by adding slowly, with continuous stirring, the aqueous solution of Na-2-MeO-Bz 0.1 mol L-1 to the respective metal sulphate solution, until total precipitation of the metal ions. The precipitate was washed with distilled water until elimination of the sulphate ion, filtered through and dried on Whatman no42 filter paper, and kept in a desiccator over anhydrous calcium chloride, under reduced pressure to constant mass. The compounds were investigated by means of infrared spectroscopy, X-Ray powder diffractometry, simultaneous thermogravimetry and differential thermal analysis (TG-DTA), Thermogravimetry derivative termogravimetry (TG/DTG), differential scanning calorimetry (DSC) and other methods of analysis. / Mestre
186

Thermal Conductivity of Nanowires, Nanotubes and Polymer-Nanotube Composites

PRADHAN, NIHAR R. 14 April 2010 (has links)
Ever rising power densities and smaller transistor dimensions are increasing the challenge of thermal management within integrated-circuit chips and their surrounding packaging. In addition, the need for sustainable energy has placed urgent emphasis on energy conversion. Thermoelectric phenomena, involving the conversion of heat to electrical current, provide a central focus for both needs. Specifically, there is a need to engineer materials or composites with low thermal conductivity and high electrical conductivity for energy conversion and the opposite for heat management. In this presentation, experimental results will be presented of the specific heat and thermal conductivity of cobalt nanowires (CoNW), carbon nanotubes (CNT) and polymer-carbon nanotubes, in various composite arrangements with our high precession Calorimetric technique. Due to the nature of these samples, boundary and defect scattering of phonons in nanomaterials can dominate. This scattering phenomena shows decreasing thermal conductivity in metal nanowires, turns to be good for thermoelectric application. For the CNT, and possibly due to the high volume per atom leading to ballistic phonon propagation, the observed thermal conductivity along the nanotube direction, which leads to manage the heat dissipation problem in integrated circuits (ICs) and microprocessors. The thermal conductivity of a single Single-Wall Carbon Nanotube (SWCNT) was found to be 6600 W/mK, theoretically, twice that of diamond. When such high thermal conductivity materials are dispersed in a low thermal conducting polymer (PMMA), the effective thermal conductivity and thermal stability of the composite can change dramatically. The experimental results show good agreement with theoretical model proposed by Nelsen, Hamilton, Crosse, Geometric, and Xue. The thermal relaxation phenomena such as glass transition temperature (Tg) and dynamics of the molecules in the polymer-nanotubes composites, changes significantly different than the pure polymers during thermal treatment and is one of the focusing point of this presentation. Liquid crystalline materials confined to restrictive nano-channels are of great interest in many potential applications of electro-optics and display technology. This part of the presentation investigates the unexplored phenomenon of the coating and filling of 8CB and 10CB liquid crystals inside ~200nm diameter Multi-Wall Carbon nanopipes. The phase transition characteristics of the confined liquid crystal films were studied using MDSC technique and will be the last part of this presentation.
187

Bench Scale Apparatus Measurement Uncertainty and Uncertainty Effects on Measurement of Fire Characteristics of Material Systems

Zhao, Lei 01 May 2005 (has links)
Traditional probability and statistics methodologies recommended by ISO and NIST were applied to standardize measurement uncertainty analysis on calorimetry bench scale apparatuses. The analysis was conducted for each component instrument (direct measurement) and each related physics quantity measured indirectly. There were many sources contributing to the ultimate uncertainty, however, initially, we dealt with the intrinsic uncertainty of each measuring instrument and the uncertainty from calibration. All other sources of uncertainty, i.e., drift, data acquisition, data reduction (round off, truncation, and curve smoothing) and personal operation were assumed to be negligible. Results were expressed as an interval having 95% confidence that the ¡°true¡± value would fall within. A Monte Carlo Simulation technique with sampling size of 10000 was conducted to model the experiments. It showed that at least 95% of the modeled experiment results were inside the estimate interval. The consistency validated our analysis method. An important characteristic of composite material systems is the ability to ¡°custom design¡± the system to meet performance criteria such as cost, durability, strength and / or reaction to fire. To determine whether a new system is an improvement over previous ones and can meet required performance criteria, sufficiently accurate and precise instruments are needed to measure the system¡¯s material properties in bench scale testing. Commonly used bench scale apparatuses are the cone calorimeter (Cone) and the FMGR fire propagation apparatus (FPA). For this thesis, thermally ¡°thin¡± and ¡°thick¡± specimens of a natural composite, red oak, were tested in the Cone in an air environment and in the FPA in a nitrogen environment. Cone test data of two FRP composite systems from the previous work of Alston are also considered. The material reaction to fire properties were estimated considering both ignition and pyrolysis measurements made via the Cone and FPA. Investigation of the ultimate uncertainty of these material fire properties based on the intrinsic uncertainty of the component instruments (e.g. load cell) as well as the uncertainty introduced via use of a current ignition and pyrolysis model are considered.
188

Comparação do efeito de três intervenções não medicamentosas sobre a evolução clínica e metabólica de crianças com excesso de peso : atenção em um ambulatório de obesidade infantil vs. atividade física dirigida vs. dieta ajustada por calorimetria

Gazal, Claudia Hallal Alves January 2013 (has links)
Introdução: A prevalência da obesidade infanto juvenil tem aumentado, sendo importante que mais profissionais estejam habilitados para o manejo. Objetivo: Comparar o efeito, após 12 meses, de três intervenções: programa de atividade física (AF), manejo dietoterápico (D) e atendimento ambulatório de referência em um hospital terciário (AMO) sobre o índice de massa corporal (IMC), composição corporal, taxa metabólica (TMB) e perfil metabólico de crianças e adolescentes com obesidade. Procedimentos Metodológicos: Ensaio clínico randomizado em 82 sujeitos de 8 a 15 anos, com obesidade. No grupo D, recebia dieta ajustada a partir da TMB por calorimetria indireta; no grupo AF, educador físico orientava prática de AF no domicílio e, no grupo AMO, orientações para introdução e manutenção de hábitos saudáveis. O acompanhamento foi mensal e os dados antropométricos, composição corporal, taxa metabólica basal e exames laboratoriais foram determinados no início, aos 6 e 12 meses de seguimento. O projeto foi aprovado pelo Comitê de Ética e Pesquisa do HCPA número 10-0011 e registrado www.clinicaltrials.gov NCT012973774. Resultados: Foram avaliados 82 sujeitos. A diferença (percentual) entre os grupos AF, D e AMO, respectivamente, foi de: escore Z do IMC -7,1% (-10,8 a -3,3), -5,0% (-8,4 a -1,5) e –15,2%(- 19,5 a -10,9); p=0,001; Peso (Kg) massa gorda 9,2% (4,3 a 14,2), 10,4% (4,8 a 15,9) e 4,3% (-1,7 a 10,4), p=0,248; Peso(Kg) massa livre de gordura 10,5%(7,5 a 13,4), 7,0% (4,1 a 10,0) e 6,7% (2,8 a 10,7) p=0,203; TMB 50,3%(2,2 a 232), 31,6%(-23,7 a 147), 38,6%(-17,3 a 232), p=0,669. As alterações laboratoriais mais frequentes no início do estudo nos grupos AMO, AF e D foram, respectivamente, valor HDL baixo (82,1%, 77,8%, 63%), insulina jejum 15 μUI/mL (71,4%, 81,5% e 66,7%) e homeostasis model assessment insulin resistence índex alterado (67,9%, 81,5%, 63%). O diagnóstico de síndrome metabólica (SM) foi feito em 20% das crianças obesas. No grupo AMO houve redução maior significativa do escore Z do IMC, da circunferência da cintura (CC), aumento do valor do HDL, redução da insulina de jejum e do HOMA-IR, redução da pressão sistólica e no número de componentes da SM. No grupo AF houve uma redução maior no colesterol total, no valor do LDL e dos triglicerídeos (TG). O grupo D também mostrou melhora no escore Z do IMC, redução do valor do colesterol total (CT), do LDL e dos TG. Apesar da redução dos indivíduos com diagnóstico de síndrome metabólica no grupo AMO (de 7 para 2) e AF (de 4 para 1) não houve diferença significativa quando comparados os 3 grupos. Conclusões: As três intervenções foram efetivas no tratamento da obesidade de crianças e adolescentes. Este estudo comprova a necessidade de estratégias combinadas e a longo prazo no manejo da obesidade na criança e adolescente para reduzir as alterações cardio metabólicas presentes nesta população e evitar a progressão dos fatores de risco para doenças cardiovasculares, metabólicas e morte prematura. Portanto, estas 3 estratégias podem ser utilizadas no manejo da obesidade infanto juvenil. / Background: The prevalence of paediatric obesity has increased in recent years, and health care workers must be trained to treat these conditions. Objective: To compare the effect of three year-long interventions: physical activity (PA) programme, dietary intervention (D) and treatment in an outpatient obesity clinic (OOC), on the body mass index (BMI), body composition, basal metabolic rate (BMR) and biochemical measurements of children and adolescents with obesity. Methodological Procedures: Randomized clinical trial of 82 participants aged between 8 and 15, diagnosed with obesity. Participants in the PA group received individualised home-based physical activity programmes from a physical education teacher. In the D group, participants received dietary counselling based on BMRs as measured by indirect calorimetry. In the OOC group, participants were given instructions on how to adopt and maintain healthy lifestyle habits. Participants had monthly appointments with physical educators, nutritionists or health care workers, depending on participant group. Anthropometric data, body composition, BMR and biochemical measurements were assessed at baseline, and after 6 and 12 months of treatment. Project approved by Comitê de Ética e Pesquisa do HCPA número 10-0011 and registred www.clinicaltrials.gov NCT012973774. Results: Differences between the PA, D and OOC groups over the course of the study were as follows: BMI Z score -7.1% (-10.8 to -3.3), -5.0% (-8.4 to -1.5) and –15.2%(-19.5 to -10.9); p=0.001; Fat mass (Kg) 9,2% (4,3 a 14,2), 10,4% (4,8 a 15,9) and 4,3% (-1,7 a 10,4), p=0,248; Fat-free mass weight(Kg) 10.5%(7.5 to 13.4), 7.0% (4.1 to 10.0) and 6.7% (2.8 to 10.7) p=0.203; BMR 50.3%(2.2 to 232), 31.6%(-23.7 to 147), 38.6%(-17.3 to 232), p=0.669. The most frequent laboratory anormalities at baseline in groups OOC, PA and D were, respectively, value low HDL (82.1%, 77.8%, 63%), fasting insulin 15 μUI / mL (71.4% , 81.5% and 66.7%) and high homeostasis model assessment insulin resistence index (67.9%, 81.5%, 63%). The diagnosis of metabolic syndrome was made in 20% of obese children. OOC group was significantly greater reduction in BMI Z score, waist circumference, total cholesterol, increasing the value of HDL, reduced fasting insulin and HOMA-IR, systolic blood pressure reduction and the number of metabolic syndrome components. In the PA group, there was a greater reduction in total cholesterol in the amount of LDL and TG. Group D also showed improvement in BMI Z score, reducing the value of total cholesterol, LDL and TG. Despite the reduction of individuals diagnosed with metabolic syndrome in the group OOC (7 to 2) and PA (4 to 1) no significant difference when comparing the three groups. Conclusions: All three interventions led to a reduction in BMI Z score, and increased fat free mass, BMR and biochemical measurements over the course of a year. This study demonstrates the need for combined strategies and long-term management of obesity in children and adolescents to reduce cardio metabolic changes present in this population and prevent the progression of risk factors for cardiovascular and metabolic diseases and premature death. Therefore, all three interventions are suitable treatments for paediatric obesity.
189

Using Design of Experiments in Validation of a new calorimetric method for the specific heat capacity determination

Babaee Koochaksaraee, Sima, Ghahremanpour, Sara January 2009 (has links)
Total Quality Management as a holistic management system is widely practical inevery organization these days and one of the foundations of TQM which should betaken into account in all functions of the company is continuous improvement.Customer satisfaction is an important topic in which continuous improvement play akey role and leads to enhance it. Therefore, it is very worthwhile for the organizationto define the designing new products/methods based on recent and future customerneeds as one of its main activities.Generally, during the development and before launching a new product/method,validation is a useful process to improve the quality and establish the qualification ofthat product/method.This project was conducted to perform a validation for a new calorimetric method byuse of DOE (Design Of Experiments) in “SP Technical Research Institute of Sweden”.The study have presented the results of implementing DOE in such a way that thenew calorimetric method is validated; besides it could determine the best condition inwhich the intended results could be achieved.This thesis is a completion part of the master program in Industrial Engineering with aspecialization in Quality and Environmental Management at University of Borås.
190

Análise térmica dos biodieseis obtidos por rota enzimática e suas respectivas matérias-primas / Thermal analysis of biodieseis obtained by enzymatic route and their raw materials.

Oliveira, Levi Ezequiel de 30 August 2010 (has links)
A maior parte de toda a energia consumida no mundo provém do petróleo, carvão e gás natural (87% da matriz energética mundial). No entanto, essas fontes não renováveis possuem previsão de esgotamento em um futuro próximo. Além disso, são poluidores, afetando o meio ambiente, motivando a sociedade buscar fontes alternativas para mitigar esses problemas. O biodiesel, como alternativa de combustível, começou a ser estudado em 1937, e hoje mostra ser uma alternativa eficiente e não poluidora à utilização do diesel mineral. O estudo presente foi realizado com amostras de biodieseis obtidos utilizando catalisadores enzimáticos. Essa rota vem sendo investigada no país por diversos pesquisadores, e vem mostrando que o uso da enzima como catalisador minimiza os problemas relativos às etapas finais de purificação do biodiesel, pois reduz a ocorrência das reações indesejáveis de saponificação e permite uma simplificação e redução dos custos dos processos pela diminuição do número de operações associadas. Para ser um substituto, o biodiesel precisa se enquadrar em normas, no caso do Brasil, a resolução nº 42 da ANP (Agência Nacional de Petróleo, Gás Natural e Biocombustíveis) de 2004. Além disso, deve possuir qualidades que viabilize a sua substituição. Esse trabalho tem o objetivo de realizar o estudo térmico utilizando a Termogravimetria (TG) e a Calorimetria Exploratória Diferencial (DSC) dos biodieseis de babaçu, palma e sebo bovino obtidos pela rota enzimática e suas respectivas matérias-primas. Com os resultados da TG em atmosfera Inerte, foi possível analisar a volatilidade desses biodieseis, e também verificar o seu enquadramento no parâmetro de destilação da resolução nº 42 da ANP. A TG em atmosfera oxidativa possibilitou comparar esses biodieseis em relação às suas estabilidades termo-oxidativas. Também foram realizados o Estudo Cinético das curvas TG, visando o valor da energia de ativação das primeiras etapas de cada curva, utilizando o modelo matemático Ozawa. O estudo cinético das curvas TG em atmosfera de nitrogênio mostrou que a energia de ativação e a temperatura de inicio da degradação têm uma relação direta. / Most of all energy consumed worldwide comes from oil, coal and natural gas (87% of global energy production). However, these non-renewable resources are expected to exhaust in the near future. Moreover, they are polluters, affecting the environment, prompting the company to seek alternative sources to mitigate these problems. Biodiesel as alternative fuel, that began to be studied in 1937 and today has proved an efficient and non-polluting alternative to the use of mineral diesel. The present study was performed with babassu, palm and tallow biodiesel obtained using enzymatic catalysts. This route has been investigated by several researchers in the country, and has shown that the use of enzyme as catalyst minimizes the problems related to the final stages of purification of biodiesel, it reduces the occurrence of undesirable reactions of saponification and allows for simplification and cost reduction processes by reducing the number of associated operations. To be a substitute, biodiesel must fit in standards, in the case of Brazil, the resolution No. 42 of the ANP (National Agency of Petroleum, Natural Gas and Biofuels), 2004. Also this biofuel must posses qualities thet might allow the replacement. This work aims to realize the thermal studies using thermogravimetry (TG) and Differential Scanning Calorimetry (DSC) of babassu, palm and tallow biodiesel obtained by enzymatic route and also their raw materials. With the results of TG in an inert atmosphere, it was possible to analyze the volatility of biodieseis, and also check your guidelines on the parameter of the distillation of Resolution No. 42 of the Brazilian Petroleum Agency (ANP). The TG analysis of biodiesel in oxidative atmosphere turns possible to study their thermo-oxidative stabilities. Also, it was performed a kinetic study of the TG curves, seeking the value of activation energy of the first steps of each curve, using the mathematical model Ozawa. The kinetic study of the TG curves in nitrogen atmosphere showed that the activation energy and temperature of the beginning of degradation have a direct relationship.

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