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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.
61

Design and development of detector modules for a highly compact and portable preclinical PET system

ur-Rehman, Fazal January 2012 (has links)
Preclinical PET systems image animal models of chronic human disease that are used to evaluate new therapeutic strategies for the treatment of cancer and other diseases. Once these animals are out of a controlled environment for PET imaging, they typically can not be taken back as they may have been exposed to outside disease. A highly compact PET system is thus required to be developed that can operate within a bio-safety cabinet inside a barrier facility. We investigated using 100-mm-long LYSO scintillator crystals oriented in the axial direction and read out at both ends by position sensitive photomultiplier tubes (PSPMTs) to construct a compact PET. The optimization of light collection for axial encoding of events was carried out using different reflector materials and surface treatments of 3 × 2 × 100 mm3 and 2 × 2 × 100 mm3 polished crystals. The detector response was examined by irradiating the crystals at discrete positions using an electronically collimated 511 keV photon beam. The ratio of two PSPMT signals was used to find the axial-resolution while their sum was used to determine the energy resolution. We then explored the effects of creating systematic band patterns of surface roughing on 1 to 4 long surfaces of the crystals to modulate light-transport with the goal of further improving axial-resolution. These experimental results were used to benchmark DETECT2000 Monte Carlo simulations for our detector geometry. The axial-positioning calibration was carried out by evaluating a uniform flood-irradiation method and comparing with the collimated-irradiation method using 2 × 2 × 100 mm3 crystal detectors. The best axial-positioning resolution of 3.4 mm was achieved in this study for 2 × 2 × 100 mm3 Teflon-wrapped crystals with banding-patterns on only two opposite surfaces, fulfilling the design criteria of our proposed PET. The benchmarked DETECT2000 models can now be used to predict the performance of a complete detector module design. The calibration methods agreed if the trigger threshold energies were adjusted to give similar single event rates in both PSPMTs for uniform flood-irradiation. The implementation of flood-irradiation method in our complete PET scanner will provide a simple axial-positioning calibration.
62

Ecoulements des solides amorphes : modélisation élastoplastique et théorie de couplage de modes / The Flow of Amorphous Solids : Elastoplastic Models and Mode-Coupling Theory

Nicolas, Alexandre 08 October 2014 (has links)
À la différence des liquides simples, les solides amorphes, une vaste catégorie de matériaux allant des verres métalliques aux émulsions concentrées, ne se mettent à s'écouler qu'au-delà d'une contrainte finie. Notre thèse a pour objet la modélisation de cet écoulement, dans un cadre général et avec un accent mis sur les hétérogénéités. En premier lieu, notre travail a porté sur l'inclusion d'inhomogénéités dans le cadre de la théorie de couplage de modes appliquée à la rhéologie et nous avons notamment obtenu une équation générale d'évolution des inhomogénéités de densité. À basse température, l'écoulement est en effet fortement hétérogène : des phases de déformation élastique sont entrecoupées de réarrangements de particules, brusques et localisés, qui interagissent par le biais des déformations élastiques qu'ils génèrent. En second lieu, nous avons donc considéré un modèle calqué sur ce scénario et affiné ses éléments constitutifs pour rendre compte de la compétition entre cisaillement appliqué et réarrangements locaux, à l'origine de la courbe d'écoulement des matériaux athermiques. Cette dernière a été reproduite de manière satisfaisante. Pour ce qui est des corrélations spatiales dans l'écoulement, nous avons montré qu'il n'existe pas de loi d'échelle universelle dans les modèles élasto-plastiques, malgré la présence d'une classe de longueurs de corrélation décroissant comme dot{gamma}^{ icefrac{-1}{d}} en d dimensions, dans le régime dominé par le cisaillement. Par ailleurs, dans diverses variantes du modèle, le cisaillement se trouve localisé dans une région du matériau. Ce phénomène apparaît dès lors que les blocs élasto-plastiques sont durablement fragilisés à la suite d'un événement plastique. Enfin, les prédictions du modèle ont été directement mises en regard avec des expériences sur l'écoulement en microcanal d'émulsions concentrées et des simulations de dynamique moléculaire à température nulle. Les écarts observés nous ont poussé à développer et implémenter un code plus flexible, qui s'appuie sur une routine simplifiée d'Éléments Finis et rend mieux compte du désordre structurel et des effets inertiels. / Contrary to the case of simple fluids, a finite stress is required to initiate the flow of amorphous solids, a broad class of materials ranging from bulk metallic glasses to dense emulsions. The objective of this thesis is to model the flow of these materials in a general framework, with an emphasis on heterogeneities. In a first approach, using the liquid regime as a starting point, I have investigated to what extent inhomogeneities can be accommodated in the framework of the mode-coupling theory of rheology. A generic equation for the evolution of density inhomogeneities has been derived. At low temperatures, the flow is indeed quite heterogeneous: it consists of periods of elastic deformation interspersed with swift localised rearrangements of particles, that induce long-range elastic deformations and can thereby spark off new rearrangements. In a second approach, a model rooted in this scenario has been refined so as to reflect the interplay between the external drive and the localised rearrangements, which is at the origin of the flow curve of athermal solids. The latter has been reproduced satisfactorily. Turning to spatial correlations in the flow, we have shown that there exists no universal scaling for these correlations in elastoplastic models, although a broad class of correlation lengths scale with dot{gamma}^{ icefrac{-1}{d}} in the shear-dominated regime in d dimensions. Besides, shear localisation has been observed in diverse variants of the model, whenever blocks are durably weakened following a plastic event. Finally, we have directly compared model predictions to experimental results on the flow of dense emulsions through microchannels and to athermal molecular dynamics simulations. Spurred on by the observation of some discrepancies, we have developed and implemented a more flexible code, based on a simplified Finite Element routine, which notably provides a better account of structural disorder and inertial effects.
63

RhéoSpeckle : un nouvel outil d’étude du comportement multi-échelle des matériaux hétérogènes / RheoSpeckle : a new tool for studying the behavior of heterogeneous materials at multi-scales

Ali, Nabil 12 February 2016 (has links)
Ce travail de thèse cherche à mieux caractériser le comportement des matériaux hétérogènes sous cisaillement avec une approche multi-échelles (macro-méso-microscopique).Cela est rendu possible en développant un montage innovant qui couple un rhéomètre à un système d’imagerie de speckle résolue spatialement et temporellement (RheoSpeckle). Nous montrons la validation de notre expérience en l’appliquant sur deux matériaux parfaits : un solide et un liquide. Sur le solide, on mesure le champ de déplacement sur les images de speckle avec une résolution meilleure que 1 µm. Puis on prouve l’élasticité du matériau à l’échelle microscopique. Sur le liquide, la taille des nanoparticules est déterminée avec un excellent accord avec la spécification du fabriquant. Le champ de vitesse dans l’entrefer du Couette est calculé avec une bonne précision sur un temps inférieur à 1 s et avec une résolution spatiale de 100 µm sur 5mm. La dynamique microscopique d’une solution brownienne est étudiée et l’influence du cisaillement sur la décorrélation est déterminée. Nous montrons les capacités de notre expérience à étudier des matériaux hétérogènes en l’appliquant sur une solution concentrée de micelles géantes. La rhéologie linéaire est étudiée en rhéometrie classique mais aussi en utilisant l’imagerie du speckle. La rhéologie non linéaire de ce matériau est déterminé en rhéometrie (macro) mais aussi en calculant le champ de vitesse et l’intensité des images de speckle (méso) ou on caractérise les bandes de cisaillement qui se forment à partir d’un cisaillement critique. En fin la relaxation spatio-temporelle des bandes de cisaillement (micro) est caractérisée. On observe pour la première fois l’existence de deux temps de relaxation après l’arrêt du cisaillement et que la relaxation des bandes est relativement lente. / This work tries to better characterize the behavior of homogeneous and heterogeneous materials under shear with a multi-scale approach (macro-meso-micro-scopic). To do that, we have developed an innovative setup by coupling a rheometer to a speckle imaging geometry witch is spatially and temporally resolved (RheoSpeckle). We validate our experience using two perfect materials: a solid and a pure viscous fluid. On a solid sample, we calculate the displacement field on the speckle images with a resolution better than 1 µm. we demonstrate than, the microscopic elasticity of this material. On a pure viscous fluid, we measured the nanoparticle’s size with excellent accuracy. When a constant shear rate is applied, the velocity profile is measured with a time less than 1 s with a spatial resolution of 100 µm over 5 mm. The microscopic dynamic of a Brownian solution under shear is probed and the shear induced on the decorrelation of the intensity correlation function is studied. We show the capabilities of our experience using a concentrated solution of wormlike micelles. The linear rheology is studied using rheometric measurements and our speckle imaging system. Nonlinear rheology is studied using rheometric measurements (macro), but also by calculating the velocity filed and the intensity of speckle images (meso). With mesocopics measurements, the formation of shear banding is proved and characterized. Finally, the spatio-temporal relaxation (micro) of shear bands of this material is studied. We show for the first time the existence of two relaxations times after shear and that the relaxation of bands is relatively slow.
64

Bons e maus resultados de perda e manutenção do peso após colocação da banda gástrica ajustável: o que o discurso do paciente revela / Good and poor outcomes following adjustable gastric banding: what the patient s feedback reveals

Scavone, Flávia de Souza 21 May 2010 (has links)
Made available in DSpace on 2016-04-28T20:40:17Z (GMT). No. of bitstreams: 1 Flavia de Souza Scavone.pdf: 1468651 bytes, checksum: d5ee7e1fa5a0a6c904942e4c28be2c3a (MD5) Previous issue date: 2010-05-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aims to observe the differences in the feedback of the patients who had good and poor outcomes following adjustable gastric banding (AGB). In-depth interviews were conducted with thirty patients (22 women), from 20 to 73 years old, who had AGB within the past 24 to 92 months. Patients were split into two groups of 15: good outcomes were considered percentage of excess weight loss (%EWL) > 40% and, poor outcomes %EWL £40%. The answers were divided into categories. Statistical analysis was performed (Fischer s Exact Test and X² Test) to test the statistical differences between categories and groups (p £ 0,05). The significant results were qualitatively analyzed based on the theoretical guidelines of analytical psychology and the Jungian approach to psychosomatic illness. Analyzing differences among patients feedback, a relationship between psychological aspects and the outcomes of the AGB was observed. The decision to have AGB based on heath-related issues, psychological treatment, a better understanding of the use of food as a defense mechanism and the development of others strategies to deal with stress was related to good outcomes. Unrealistic expectations to the AGB outcomes, leaving treatment, conflictive relationship with medical team, stressful situations and high intake of sweets were related to poor outcomes. It was understood that the patients from the group with poor results had more difficulty elaborating on the many psychological aspects that are directly related to their eating behavior. This understanding suggests how important is to have psychological guidance after bariatric surgery to achieving good outcomes / Este estudo visa observar diferenças no discurso dos pacientes com bons e maus resultados após colocação da banda gástrica ajustável (BGA). Para isso, foi realizada entrevista semidirigida com trinta pacientes (22 mulheres), entre 20 e 73 anos e com tempo de pós-operatório entre 24 e 92 meses. Os entrevistados foram divididos em dois grupos de quinze, de acordo com critério de divisão em que bons resultados foram considerados porcentagem de perda do excesso de peso (%PEP) > 40% e maus resultados, %PEP £ 40%. As respostas das questões abertas foram transformadas em categorias e realizou-se análise estatística (Teste Exato de Fischer e Teste do x²) buscando diferenças significativas entre as categorias e os grupos (p £ 0,05). As diferenças foram analisadas por meio do referencial teórico da Psicologia Analítica e do modelo da psicossomática junguiana. Foram observadas diferenças no discurso dos pacientes, sugerindo relação entre aspectos psicológicos e resultados pós-cirúrgicos. Escolher o tratamento por preocupações com a saúde, fazer acompanhamento psicológico, compreender o comer demais como mecanismo de defesa e desenvolver outras estratégias para lidar com o estresse foram relacionados a bons resultados. Expectativas irreais sobre os resultados, passar por situações de estresse, abandono precoce do tratamento, não ter bom relacionamento com a equipe e alto consumo de doces foram relacionados a maus resultados. Compreende-se que o grupo dos maus resultados apresentou dificuldade em elaborar os aspectos psicológicos relacionados ao comportamento alimentar, sugerindo a importância do acompanhamento psicológico na busca de melhores resultados após cirurgia bariátrica
65

Uma abordagem sistemática em espécies de astyanax (characiformes, characidae, incertae sedis) da bacia do alto-médio rio Uruguai através da análise citogenética básica e molecular

Gavazzoni, Mariane 22 February 2016 (has links)
Made available in DSpace on 2017-07-10T14:17:13Z (GMT). No. of bitstreams: 1 Dissertacao PPRN Mariane_ Gavazzoni 2016.pdf: 1443094 bytes, checksum: 5fe99142fa5f6e62c58e029f07ceeebb (MD5) Previous issue date: 2016-02-22 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Astyanax is a polyphyletic taxon with richness of species and wide geographic distribution. Astyanax comprises species that are morphologically very similar with poorly detailed taxonomic delimitations, which makes it difficult to identify and to establish phylogenetic relationships. In order to provide data to contribute to cytogenetic, taxonomy and systematics of Astyanax, cytogenetics analyzes were carried out on ten Astyanax species from three river basins. Astyanax altiparanae and A. aff. fasciatus were collected on the Upper Paraná River basin; A. abramis and A. asuncionensis were collected on the Middle-low Paraná River basin; and A. cf. aramburui, A. eigenmanniorum, A. aff. fasciatus, A. jacuhiensis, A. aff. laticeps, A. cf. paris and Astyanax sp. were collected on the Upper-Middle Uruguai River basin. The results show interespecific variation in diploid number, 2n=46 chromosomes for A. cf. aramburui and A. aff. fasciatus, 2n=48 chromosomes for A. eigenmanniorum, and 2n=50 chromosomes for the remaining species. NORs (Ag-staining and 18S rDNA-FISH) showed species bearing single sites and species bearing multiple sites (up to 10 cistrons in Astyanax sp.), confirming the high variability reported for the genus. The species from A. bimaculatus complex (A. abramis, A. altiparanae, A. jacuhiensis e A. asuncionensis) showed single NORs, a plesiomorphic condition for the complex. FISH with 5S rDNA probes revealed a more conserved condition, with centromeric sites in at least one metacentric chromosome pair and one subtelocentric/acrocentric chromosome pair, however with interspecific variation, which proves it to be an important marker in the characterization and differentiation of these species. Heterochromatin distribution pattern was distinct for all species, except for A. cf. aramburui and A. aff. fasciatus (Ijuí River). This demonstrates that cytogenetic similarities may indicate closer relationship between each other than among to the other analyzed species; on the other hand, 5S rDNA genes showed to be important in differentiation of these cryptic species. The results reported the first cytogenetic data for A. cf. paris and reinforce their cytogenetic similarity with other congenus species, and we also report the occurrence of a Astyanax species that has not been taxonomically described yet. Thus, the results of this study provide data that assist taxonomy and systematic of Astyanax clade and Astyanax paris clade , reinforcing the need for extensive revisions, especially in A. bimaculatus and A. fasciatus complex, including markers such as 5S rRNA and heterochromatin distribution pattern, forthe better understanding of the phylogenetic relationships in Astyanax. / Astyanax é um taxon polifilético com grande riqueza de espécies e ampla distribuição geográfica. Compreende espécies com formas bastante semelhantes e delimitações taxonômicas pouco detalhadas que dificultam a identificação e o estabelecimento das relações filogenéticas. Com o objetivo de fornecer dados que contribuam com a citogenética, taxonomia e sistemática de Astyanax, foram realizadas análises citogenéticas em dez espécies de Astyanax de três bacias hidrográficas. Foram coletados exemplares de Astyanax altiparanae e A. aff. fasciatus na bacia do Alto rio Paraná; A. abramis e A. asuncionensis na bacia do Médio-Baixo rio Paraná; e A. cf. aramburui, A. eigenmanniorum, A. aff. fasciatus, A. jacuhiensis, A. aff. laticeps, A. cf. paris e Astyanax sp. na bacia do Alto-Médio rio Uruguai. Os resultados mostraram variação interespecífica no número diplóide, de 2n=46 cromossomos em A. cf. aramburui e A. aff. fasciatus, 2n=48 cromossomos em A. eigenmanniorum, e 2n=50 cromossomos nas demais espécies. As AgRONs, confirmadas pela 18S rDNA-FISH, evidenciaram espécies portando sítios simples e espécies portando sítios múltiplos (até 10 cístrons em Astyanax sp.), confirmando a alta variabilidade encontrada no gênero. Nas espécies do complexo A. bimaculatus (A. abramis, A. altiparanae, A. jacuhiensis e A. asuncionensis), foram evidenciadas RONs simples, característica plesiomórfica para o complexo. FISH com sonda de 5S rDNA evidenciou uma condição mais conservada, com cístrons centroméricos em pelo menos um par de cromossomos metacêntricos e em um par de cromossomos subtelocêntricos/acrocêntricos, porém com variação interespecífica, demostrando ser um importante marcador na caracterização e diferenciação destas espécies. O padrão de distribuição da heterocromatina mostrou-se distinto para as espécies, com exceção de A. cf. aramburui e A. aff. fasciatus (rio Ijuí), onde foi verificado semelhanças citogenéticas que podem indicar maior proximidade entre estas espécies quando comparadas com as demais analisadas, sendo que a distribuição dos genes 5S rDNA se mostrou importante na diferenciação destas espécies crípticas. Os resultados relatam os primeiros dados citogenéticos para A. cf. paris e reforçam sua semelhança citogenética com outras espécies congêneres, além de relatar a ocorrência de uma espécie de Astyanax ainda não descrita taxonomicamente. Em suma, os resultados do presente estudo fornecem dados que auxiliam na taxonomia e sistemática do clado Astyanax e clado Astyanax paris , reforçando a necessidade de revisões amplas, principalmente nos complexos A. bimaculatus e A. fasciatus que incluam marcadores como 5S rDNA e padrão de distribuição da heterocromatina, para melhor compreensão das relações filogenéticas em Astyanax.
66

The Effect of Pay Banding on Generational Cohort Perceptions of Job Satisfaction

Polk, Charles Terence 01 January 2015 (has links)
For over 3 decades, the federal government has attempted to introduce pay-for-performance into the federal workforce. It is important for federal agencies to understand the impact of pay-for-performance, specifically pay banding, on job satisfaction and retention of frontline managers as agencies face the exodus of the retiring Baby Boomer generation. The purpose of this study was to explore the effect of pay banding on job satisfaction and intention of frontline managers to leave the Internal Revenue Service (IRS). The theoretical foundation for this study was Adams's equity theory as viewed through the lens of Mannheim's generational theory. The overarching research question was concerned with whether pay banding effects generational perceptions of job satisfaction and predicts turnover intention. This quantitative study used ANOVA, hierarchical multiple regression, mediation analysis, moderation analysis, and logistic regression to analyze the impact of pay banding on generational perceptions of job satisfaction and turnover intention among IRS frontline managers. The sample was limited to frontline managers of the Department of the Treasury (n = 2,525). Key findings indicated that pay banding was negatively associated with job satisfaction and that pay banded managers were 1.36 times more likely to leave the agency than managers who were not pay banded. Pay banding mediated the relationship between gender and job satisfaction. Positive social changes that may result from governmental policymakers applying the findings of this study are improved retention of highly skilled frontline managers, improved the efficiency and effectiveness of government services, and reduced cost of retraining managers due to attrition. These changes may improve the work environment for employees and improve governmental services provided to the citizenry.
67

Modélisation numérique de la rupture ductile dynamique par cisaillement adiabatique et micro-endommagement couplés / Numerical modelling of coupled adiabatic shear banding and micro-voiding assisted dynamic ductile failure

Dorothy, Hannah Lois 15 October 2018 (has links)
Les matériaux à haute résistance, notamment les aciers et les alliages à base d'aluminium et de titane, sont largement utilisés dans l'aéronautique comme matériaux structuraux et de protection. Dans le cas de surcharges accidentelles impliquant des vitesses de chargement élevées et des conditions quasi adiabatiques, ces matériaux sont souvent sensibles au cisaillement adiabatique par bande. Les bandes de cisaillement adiabatique (BCA) sont des zones étroites de cisaillement intense qui résultent d'une instabilité thermomécanique et qui conduisent à une rupture prématurée du matériau. À un stade avancé du processus de localisation, des micro-cavités (MCs) ont été observées dans les BCAs. Ces MCs peuvent coalescer pour former des fissures et mener à la rupture de la structure. Ainsi, les mécanismes couplés d'ASB+MC agissent comme un précurseur à la rupture catastrophique et il est par conséquent important de modéliser numériquement leurs effets dans des structures soumises à des sollicitations à haute vitesse. Les BCAs apparaissent aussi dans certaines applications industrielles, telles que l'usinage à grande vitesse, où elles favorisent le festonnement du copeau. Un postulat de grande échelle est appliqué ici où la longueur caractéristique du volume élémentaire représentatif (VER) est plus grande que la largeur de bande, et non l'inverse comme fait communément. L'objectif du travail présenté est d'enrichir un modèle décrivant les effets des BCAs en prenant en compte les conséquences de l'endommagement par MC dans le processus progressif de la rupture. Les effets des BCAs et des MCs sur la réponse du VER sont doubles : cinématique, à savoir une déviation progressif de l'écoulement plastique dans le plan de la bande décrite via des gradients de vitesse induits par les BCAs et par les MCs; et matériel, à savoir une dégradation anisotrope des modules élastiques et plastiques décrite via des variables tensorielles d'ordre deux de détérioration induite par les BCAs et par les MCs. L'amorçage des BCAs est déterminé à partir d'une analyse linéaire de stabilité et celui des MCs par une valeur critique du taux de restitution d'énergie local. L'intérêt de ce modèle avancé est démontré par comparaison avec un modèle orienté application du type (1-D) où D est une variable de détérioration isotrope. Le modèle enrichi ASB+MC est implémenté comme matériau utilisateur dans le code de calculs commercial par éléments finis LS-DYNA. [...] / High strength metallic materials, notably steel and light-weight titanium and aluminium alloys, are widely used in aeronautical and other structures. In case of accidental overload involving high strain rates and quasi adiabatic conditions, these materials are often susceptible to adiabatic shear banding. The adiabatic shear bands (ASB) are intense shear localisation zones resulting from thermomechanical instability and provoking premature material failure. At an advanced stage of the localisation process, the ASBs have been shown to contain micro-voids (MV) which may coalesce to form cracks and ultimately lead to the fracture of the structure. Thus the coupled mechanisms of ASB+MV act as a precursor to catastrophic failure and it is consequently crucial to numerically model their formation and effects when dealing with structures submitted to high loading rates. The ASBs are also observed in industrial applications such as high speed machining where their formation favours the chip serration. A large scale postulate is used herein to obtain a global insight into the structural material response. The shear band cluster is indeed contained/ embedded within the representative volume element (RVE), and not the opposite as usually considered. The objective here is to enrich a model describing the ASB effects by taking into account the consequences of the micro-voiding within the progressive failure process. The effects of ASB and MV initiation and evolution on the RVE (material point) response are double: kinematic, namely a progressive deviation of the plastic flow in the band plane described via specific ASB and MV induced velocity gradients; and material, namely a progressive anisotropic degradation of the elastic and plastic moduli described via ASB and MV induced second order tensor deterioration variables. The ASB onset criterion is derived from the linear perturbation analysis and the MV is activated using a critical value for the local energy release rate. The interest of this advanced constitutive model is emphasised by comparison with an application oriented (1-D) model where D is a scalar damage variable. [...]
68

Bariatric Surgery Using Different Adjustable Gastric Bands: the Results of Prospective Randomised Study / Nutukimo chirurginis gydymas naudojant skirtingas skrandį apjuosiančias reguliuojamas juostas: perspektyviojo atsitiktinės atrankos imčių biomedicininio tyrimo rezultatai

Abalikšta, Tomas 22 November 2011 (has links)
It has been estimated that LAGB represents about 42% of bariatric operations performed worldwide. There are a number of different adjustable gastric bands available. Few attempts have been made to compare the influence of band design differences for efficiency and complication rate. There are no accepted criteria for choosing this particular operation. In the dissertation we compared one year results after adjustable gastric banding using different adjustable gastric bands – SAGB and MiniMizer Extra. We have determined that laparoscopic adjustable gastric banding is effective and safe bariatric procedure: the average percentage of initial excess body mass index loss was 33,1 ± 21,9%; 34.1% of patients achieved fair, 30,6% - good, 9,4% - very good and 2,4% - excellent results according to BAROS; only 5 (4,9%) major complications were diagnosed. No radical differences were stated between the efficiency and complication rate of the compared adjustable gastric bands: the average percentage of initial excess body mass index loss in SAGB and MiniMizer Extra groups was 28,9 ± 21,3% and 36,8 ± 22.1% respectively, p=0.075; major complication rate was 0 (0%) and 5 (9.3%) respectively, p=0.069. Patients at the age of 40 and older achieved better results using MiniMizer Extra band - the average percentage of initial excess body mass index loss was 37,5 ± 20,8% versus 23,6 ± 13,8% in SAGB group, p=0.002. Patients with initial BMI ≤ 47 achieved better results using MiniMizer Extra band... [to full text] / Šiuo metu Pasaulyje skrandžio apjuosimo reguliuojama juosta operacijos sudaro apie 43 % visų chirurginių operacijų, atliekamų nutukimui gydyti. Iki šiol nėra pilnai ištirta operacijoje naudojamų skrandį apjuosiančių reguliuojamų juostų konstrukcijos skirtumų įtaka gydymo rezultatams, taip pat nėra priimtų pacientų atrankos šiai operacijai kriterijų. Disertacijoje palyginome vienerių metų nutukimo chirurginio gydymo rezultatus naudojant skirtingas skrandį apjuosiančias reguliuojamas juostas – SAGB ir MiniMizer Extra. Nustatėme, kad skrandžio apjuosimo reguliuojama juosta operacija yra efektyvus ir saugus nutukimo gydymo būdas: vidutinis procentinis perteklinio kūno masės indekso sumažėjimas buvo 33,1 ± 21,9%; vertinant pagal BAROS, 34.1% pacientų pasiekė patenkinamą, 30,6% - gerą, 9,4% – labai gerą ir 2,4% – puikų gydymo rezultatą; pasitaikė 5 (4,9%) „didžiosios” komplikacijos. Esminių skirtumų tarp lygintų juostų efektyvumo ir komplikacijų skaičiaus po vienerių metų po operacijos nenustatyta: vidutinis procentinis perteklinio kūno masės indekso sumažėjimas SAGB ir MiniMizer Extra grupėse buvo atitinkamai 28,9 ± 21,3% ir 36,8 ± 22.1%, p=0.075, o „didžiųjų” komplikacijų skaičius atitinkamai 0 (0%) ir 5 (9.3%), p=0.069. 40 metų ir vyresni pacientai geresnių rezultatų pasiekė naudojant MiniMizer Extra juostą - vidutinis procentinis perteklinio kūno masės indekso sumažėjimas buvo 37,5 ± 20,8% prieš 23,6 ± 13,8 % SAGB grupėje, p=0.002. Pacientai, kurių pradinis KMI ≤ 47, geresnių... [toliau žr. visą tekstą]
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Bariatric Surgery for Obesity: A Systematic Review and Meta-analysis

Alobaid, Abdulhakeem M. 14 May 2013 (has links)
Obesity is the fifth leading cause of global deaths. The efficacy and safety of obesity treatment is still controversial. The objective of the thesis is to evaluate the efficacy and safety of bariatric surgery, through a systematic review of the current evidence and meta- analysis of important outcomes. Nineteen (19) randomized controlled trials (RCTs) with 1346 participants were included. Bariatric surgery resulted in greater weight loss when compared to non-surgical treatment. Weight loss was also associated with resolution and/or improvement of obesity related comorbidites such as diabetes, hypertension, hyperlipidemia, and sleep apnea. Weight loss and safety varied across the surgical procedures. Biliopancreatic diversion/duodenal switch had the greatest weight loss, followed by sleeve gastrectomy and Roux-en-Y gastric bypass, purely restrictive procedures such as vertical banded gastroplasty and adjustable gastric banding resulted in the least weight loss. Long term, high quality, and adequately powered trials are still needed to support the available evidence
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Estudos cariotípicos em Asteraceae da Reserva Biológica Municipal (RBM) Serra do Japi (SP) / Karyotypic studies in Asteraceae from the Municipal Biological Reserve (MBR) of Japi mountain range (SP)

Braga, Klenya Rosa Rocha, 1978- 09 September 2014 (has links)
Orientador: Eliana Regina Forni Martins / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-25T23:43:47Z (GMT). No. of bitstreams: 1 Braga_KlenyaRosaRocha_D.pdf: 3638781 bytes, checksum: f3a0b3548e4388cdabb276fb9662c32a (MD5) Previous issue date: 2014 / Resumo: A família Asteraceae (Compositae) possui cerca de 23.000 espécies e 1.600 gêneros. Sua distribuição é cosmopolita, com representantes em todos os continentes. Sua maior diversidade está na América do Sul. A família está bem representada no Brasil (cerca de 300 gêneros e 2.000 espécies), ocorrendo principalmente em formações abertas, como cerrados e campos. Cassini, em 1817 foi o primeiro a propor um sistema de classificação para a família, que foi alterado por vários autores. Atualmente a família está dividida 12 subfamílias e 43 tribos. Dentre os parâmetros que podem ser obtidos a partir de estudos citogenéticos, o número cromossômico é o mais amplamente utilizado. Estima-se que cerca de 61,6% dos gêneros de Asteraceae possuem pelo menos uma contagem de números cromossômicos, sendo relatada grande variação (2n= 4 a ca. 432). O número básico x=9 é o mais frequente. Apesar do número considerável de trabalhos referentes à contagem cromossômica e análise de cariótipos de espécies de Asteraceae, este número ainda é muito pequeno quando comparado com a riqueza de espécies da família. No que diz respeito aos estudos cromossômicos utilizando bandamento cromossômico e hibridização de DNA in situ, os trabalhos são mais escassos. Diante da riqueza de espécies, da diversidade cariotípica da família e da carência de dados citogenéticos para subsidiar a reavaliação das delimitações de seus grupos taxonômicos, este trabalhou objetivou caracterizar o cariótipo de diversas espécies nativas de Asteraceae proveniente da Reserva Biológica Municipal (RBM) da Serra do Japi uma das últimas grandes áreas de floresta contínua do Estado de São Paulo, que apresenta uma grande diversidade de espécies de Asteraceae. Foram feitos a determinação do número cromossômico, o detalhamento de caracteres morfológicos dos cromossomos (tamanho e forma) e a aplicação de técnicas de bandamento CMA/DAPI e técnica de FISH. Foi determinado o número cromossômico de 35 espécies, as quais estão distribuídas em 14 tribos e 26 gêneros, com variação de 2n=16 a 72. As tribos mais bem representadas foram Eupatorieae (9spp.), Vernonieae (6spp.) e Astereae (5spp.). Seis novas contagens foram determinadas e quatro divergiram de relatos anteriores: Bidens subalternans (2n=72), Chromolaena odorata (2n=30), Praxelis kleineoides (2n=30) e Vernonia diffusa (2n=34). Os cariótipos podem ser considerados moderadamente simétricos, com o índice TF% variando de 29 em Praxelis kleineoides (2n=30) a 44 into G. intermedia (2n=20). Dezesseis espécies foram submetidas à técnica de bandamento CMA/DAPI. Houve variação de 2 a 12 bandas CMA+/DAPI-. A técnica de FISH revelou diferenças cariotípicas em cinco espécies estudadas: Conyza sumatrensis var. leotheca, Bidens pilosa, Mikania sp, Vernonia diffusa e V. remotiflora, que apresentaram 2 a 6 sítios de DNAr 45S e 2 a 3 sítios de DNAr 5S. Nossos dados de bandamento CMA/DAPI e FISH são inéditos para todas as espécies estudadas / Abstract: The Asteraceae family (Compositae) comprises around 23.000 species and 1.600 genera. Its distribution is comospolitan, with representatives in all continents. The highest diversity is found in South America. The family is well represented in Brazil (with 300 genera and 2.000 species), mainly occurring in the opened formations, like savannas and fields. Cassini, in 1817 was the first to propose a system of classification for the family, which was later changed by several authors. Nowadays the family is divided in 12 subfamilies and 43 tribes. Among the parameters that can be obtained from cytogenetic studies, the number of chromosomes is the most commonly used. Its estimated that about 61,6% of Asteraceae genera have at least a count chromosome numbers, being reported wide variation (2n= 4 a ca. 432). The basic number x=9 is the most frequent. In spite of considerable number of works on the chromosomal count and karyotpe analysis from species of Asteraceae, this number is still very small when compared with species richness within the family. In respect of chromosomal studies used in the chromosome banding and in situ DNA hybridization, the works are more scarce. Before wealth of species, of karyotype diversity of family and of lack of data cytogenetics to subsidize the revaluation of delimitations of its taxonomic groups, this work aims to characterize the karyotype of several native species of Asteraceae from the Municipal Biological Reserve (MBR) of Japi, one of the last large areas of continuous forest of São Paulo, that has a great diversity of species of Asteraceae. We determined the chromosomal number, detailing the morphological characters of chromosomes (size and shape), and applied techniques of CMA/DAPI banding and FISH. We determined the chromosome number of 35 species, which are distributed in 14 tribes and 26 genera, ranging from 2n = 16-72. The most well represented tribes were Eupatorieae (9spp.), Vernonieae (6spp.) and Astereae (5spp.). Six new counts were determined and four differed from previous scores: Bidens subalternans (2n=72), Chromolaena odorata (2n=30), Praxelis kleineoides (2n=30) and Vernonia diffusa (2n=34). The karyotpes can be considered moderately symmetric, with index TF% ranging from 29 in Praxelis kleineoides (2n=30) to 44 in G. intermedia (2n=20). Sixteen species were submitted to technique of banding CMA/DAPI. There were variations of 2 to 12 CMA+/DAPI- bands. The technique of FISH revealed varied karyotypes in five species: Conyza sumatrensis var. leotheca, B. pilosa, Mikania sp, Vernonia diffusa and V. remotiflora showed 2 to 6 sites of 45S rDNA and 2 to 3 sites of 5S rDNA. Our data of banding CMA/DAPI and FISH are original for all studied species / Doutorado / Biologia Vegetal / Doutora em Biologia Vegetal

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