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Efeitos da sitagliptina no tecido ósseo em ratos diabéticos e não diabéticos / Effects of sitagliptin on bone tissue in diabetic and non-diabetic ratsBautista, Cristhian Reynaldo Gomez 30 May 2018 (has links)
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Previous issue date: 2018-05-30 / A diabetes mellitus, doença caracterizada pelo aumento da glicemia no sangue, é um dos mais importantes problemas de saúde pública do mundo, com incidência crescente, sobretudo em países em desenvolvimento. Novas terapias medicamentosas para controlar os níveis de glicose no sangue têm sido desenvolvidas, entre elas, os inibidores da enzima dipeptidil peptidase-4 (DPP-4) como a sitagliptina. Pesquisas atuais mostram que este medicamento, além do controle da glicemia, contribui na estimulação da formação e inibição da reabsorção óssea e possui ação anti-inflamatória. O objetivo deste trabalho foi avaliar os efeitos da sitagliptina no tecido ósseo em ratos diabéticos e não diabéticos. Foram utilizados 38 ratos machos, divididos em 4 grupos: Grupo diabético tratado com sitagliptina (GDS- 10 mg/Kg/dia); Grupo diabético (GD); Grupo normoglicêmico tratado sitagliptina (GNS-10 mg/Kg/dia); Grupo normoglicêmico (GN). Para indução da diabetes os animais receberam solução 10% de frutose na água de beber por 14 dias, após o quê receberam 40 mg/Kg de estreptozotocina via intraperitoneal. Quatro semanas depois, avaliou-se a glicemia e iniciou-se o tratamento com sitagliptina nos grupos GDS e GNS, que continuou por mais 4 semanas, quando ocorreu a eutanásia. A glicemia e a resistência à insulina (HOMA-IR) foram avaliadas também no dia da eutanásia. As tíbias foram removidas e avaliadas a porcentagem de volume ósseo (BV/TV), espessura trabecular (Tb.Th), número de trabéculas (Tb.N) e a separação de trabéculas (Tb Sp) da metáfise tibiana por microtomografia computadorizada. Os dados foram submetidos à análise estatística, ao nível de 0,05. Os animais dos grupos GD e GDS apresentaram maior glicemia que os animais dos demais grupos, mas não houve diferença entre os grupos com relação aos dados de HOMA-IR, evidenciando a indução de diabetes do tipo I. Os animais diabéticos apresentaram menor BV/TV e Tb.N, e maior Tb.Sp. Não houve diferença com relação à Tb.Th. O modelo experimental foi eficaz para a indução da diabetes, mas o tratamento com sitagliptina não foi suficiente para reverter os efeitos da diabetes no tecido ósseo. / Diabetes mellitus, a disease characterized by increased blood glucose levels, is one of the most important public health problems in the world, with a growing incidence, especially in developing countries. New drug therapies to control blood glucose levels have been developed, including dipeptidyl peptidase-4 (DPP-4) inhibitors such as sitagliptin. Current research shows that this drug, in addition to glycemic control, contributes to stimulate the formation and inhibition of bone resorption and has an anti-inflammatory action. The aim of this study was to evaluate the effects of sitagliptin on bone tissue in diabetic and non-diabetic rats. Thirty-eight male rats were divided into four groups: Diabetic group treated with sitagliptin (GDS-10 mg / kg / day); Diabetic group (GD); normoglycemic group treated with sitagliptin (GNS-10 mg / kg / day); normoglycemic group (GN). For induction of diabetes the animals received 10% solution of fructose in the drinking water for 14 days, after which they received 40 mg / kg streptozotocin intraperitoneally. Four weeks later, glycemia was evaluated and sitagliptin treatment was started in the GDS and GNS groups, which continued for another 4 weeks, when euthanasia occurred. Blood glucose and insulin resistance (HOMA-IR) were also evaluated on the day of sacrifice. Bone volume (BV/TV), trabecular thickness (Tb.Th), number of trabeculae (Tb.N) and trabeculae separation (Tb.Sp) of the tibial metaphysis were evaluated by computerized microtomography. Data were submitted to statistical analysis at the 0.05 level. The animals of groups GD and GDS presented higher glycemia, but there was no difference regarding HOMA-IR, evidencing diabetes type I induction. The animals in which diabetes was induced presented lower BV/TV and Tb.N, and higher Tb.Sp. There was no difference among groups in TB.Th. The experimental model was sufficient for the induction of diabetes, but treatment with sitagliptin was not enough to reverse the effects of diabetes on bone tissue.
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A computer simulation study of liquid crystal phase coexistenceMills, Stuart James January 1999 (has links)
Results are presented from a variety of molecular simulations of phase coexistence using the well established Gay-Berne (GB) liquid crystal model. Firstly, the simulation of bulk phase coexistence using the Gibbs ensemble Monte Carlo technique is presented, both for one and two-component GB systems. The one-component results, using a novel parameterisation of the GB, show a rich phase behaviour, displaying both isotropic and nematic-vapour coexistence, in good comparison with previous studies. A method for arriving at the two-component parameterisation is then discussed, followed by a novel application of the Gibbs ensemble to the isotropic-nematic transition in two-component systems. Results in broad agreement with theoretical predictions, subject to a large finite size effect, are obtained. Secondly, upon the basis of the one-component Gibbs results, results are presented from a series of molecular dynamics simulations of a free standing GB film in equilibrium with its own saturated vapour. The introduction of inhomogeneity is shown to induce a preferred molecular alignment in the nematic film perpendicular to the liquid-vapour interface. At slightly higher temperatures the nematic film is wet by the isotropic phase, displaying an intermediate ordering regime where the formation of short-lived nematic domains within the film is observed. This effect has been analysed using orientational correlation functions, and shown to result from a decoupling of the planar and perpendicular nematic ordering caused by the system inhomogeneity. A system-size analysis of this effect has also been undertaken, showing a definite increase in the range of decay of these orientational correlations with increasing system size.
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A Model of Process-Based Automation: Cost and Quality Implications in the Medication Management ProcessJanuary 2011 (has links)
abstract: The objective of this research is to understand how a set of systems, as defined by the business process, creates value. The three studies contained in this work develop the model of process-based automation. The model states that complementarities among systems are specified by handoffs in the business process. The model also provides theory to explain why entry systems, boundary spanning systems, and back-end control systems provide different impacts on process quality and cost. The first study includes 135 U. S. acute care hospitals. The study finds that hospitals which followed an organizational pattern of process automation have better financial outcomes. The second study looks in more depth at where synergies might be found. It includes 341 California acute care hospitals over 11 years. It finds that increased costs and increase adverse drug events are associated with increased automation discontinuity. Further, the study shows that automation in the front end of the process has a more desirable outcome on cost than automation in the back end of the process. The third study examines the assumption that the systems are actually used. It is a cross-sectional analysis of over 2000 U. S. hospitals. This study finds that system usage is a critical factor in realizing benefits from automating the business process. The model of process-based automation has implications for information technology decision makers, long-term automation planning, and for information systems research. The analyses have additional implications for the healthcare industry. / Dissertation/Thesis / Ph.D. Information Management 2011
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Reconstrução tridimensional de objetos a partir das projeções de suas secções / Tridimensional objects reconstruction from the projections of theirs sectionsMattos, Patrícia Noll de January 1996 (has links)
Este trabalho trata da reconstrução tomográfica bidimensional e tridimensional, a partir de projeções, visando sua utilização em qualquer aplicação que necessite do volume completo do objeto em questão ou que necessite das imagens adquiridas dos- objetos projetados. Propicie-se utilizar um dos métodos pelo qual a tomografia Computadorizada gera as fatias bidimensionais do corpo exposto, expandindo-o para a terceira dimensão. Para tornar isto possível, é necessário o estudo de métodos de reconstrução-bidimensional, bem como a implementação de um deles. E desenvolvido, então, um estudo sobre os conceitos da tomografia computadorizada, seus diferentes tipos, contendo, os métodos de reconstruçãobidimensional utilizado por elas, alem, dos métodos de aquisição das projeções dos objetos a serem reconstruídos. E apresentada uma proposta de trabalho bidimensional, onde será implementado, alem do algoritmo de reconstrução, o processo de aquisição das projeções do objeto em questão, bem como, a modelagem do mesmo. Além, do desenvolvimento de uma proposta de trabalho tridimensional, onde o método de reconstrução bidimensional desenvolvido será expandido para a terceira dimensão e implementado, juntamente com o processo de aquisição dos objetos tridimensionais projetados, bem como, a modelagem dos mesmos. Um protótipo para cada uma destas propostas é gerado, contendo, cada um, a etapa de aquisição das imagens projetadas, e a etapa de reconstrução do objeto. Tanto os resultados da imagem sendo reconstruída, como as imagens adquiridas dos objetos projetados, são Bravados em arquivos. Por fim, é apresentada uma analise dos resultados gerados por estes protótipos, no que diz respeito a convergência de seus algoritmos, e a melhor maneira de utilizá-los, a fim de se obter um melhor resultado. / This paper is about bidimensional and tridimensional tomographic reconstruction working with projections in order to use in any application that needs complete volume of the object used or that needs images of the projected objects acquired. It is used one of the methods by which the computerized tomography generates bidimensional slices of the exposed body expanding it to third dimension. In order to make it possible it was necessary to study bidimensional reconstruction methods, as well as implementing one of them. It is developed a study on concepts of computerized tomography, its different types, including bidimensional reconstruction methods used by them, besides the methods used to acquire projections of the objects to be reconstructed. It is presented a proposal of the bidimensional work, where it will be implemented, besides the reconstruction algorithm, the aquisition process of the projection of the meant objects, as well as modelling them. It is also developed a proposal of a tridimensional work, where the bidimensional reconstruction method developed will be implemented and expanded to third dimension as well as the process of aquisition of the tridimensionals projected objects as well as modelling them. A prototype of these proposals is generated , containing each one the aquisition step of the projected images and the reconstruction step of the object. The results of the reconstructed image as well as the acquired images of the projected objects are saved in files. Finally it is presented an analysis of the generated results of the prototypes as to the convergence of these algorithms and the best way to use them in order to obtain a better result.
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Análise bi e tridimensional das alterações morfológicas em raízes mesiais de molares inferiores com curvaturas severas preparados por diferentes sistemas mecanizados. Estudo por microtomografia computadorizada / Bi and three-dimensional analysis of morphological alterations in mesial roots of mandibular molars with severe curvatures prepared by different mechanized systems. Computerized microtomography studyLuís Eduardo Souza Flamini 19 April 2017 (has links)
O presente estudo teve como objetivo analisar, por meio de microtomografia computadorizada, os parâmetros morfológicos das raízes mesiais de molares inferiores, preparados por três sistemas mecanizados: reciprocante (Reciproc - RC), rotatório contínuo (OneShape - OS) e reciprocante/rotatório (Twisted-File Adaptive - TFA), precedidos ou não de pré-alargamento (ProGlider - PG). Foram utilizados trinta molares inferiores, com raiz mesial apresentando ângulo (≥25º) e raio de curvatura (≤2mm) severos e dois canais distintos. Por meio da técnica de amostragem estratificada, os canais foram distribuídos em seis grupos (n=10) conforme protocolo de instrumentação: G1-TFA; G2-RC; G3-OS; G4-PG + TFA; G5 - PG + RC; G6- PG + OS. Após o preparo, foram avaliados os parâmetros bidimensionais (área, perímetro, circularidade, diâmetro maior e menor) nos 5mm apicais e tridimensionais (volume, área de superfície e SMI), bem como o transporte do canal radicular. Os dados obtidos foram analisados estatisticamente por meio do teste ANOVA seguido do complementar de Tukey (α=0,05). O RC apresentou valores, significantemente, maiores de área, perímetro e diâmetro menor em relação ao TFA (p<0,001), não havendo diferença significante entre os sistemas em relação à circularidade (p=0,056) e diâmetro maior (p=0,477). O aumento do volume do canal proporcionado pelos sistemas RC e OS foram semelhantes entre si (p=0,979) e diferente estatisticamente ao TFA (p<0,001). O aumento da área de superfície promovida pelo RC foi similar ao OS (p=0,254) e diferente estatisticamente ao TFA (p=0,001), não havendo diferença entre os dois últimos sistemas (p=0,075). Os valores de SMI do grupo PG + OS foram significativamente maiores que dos demais grupos (p<0,001). Não houve diferença entre os sistemas em relação ao transporte nos terços apical e médio. Concluiu-se que todos os sistemas avaliados apresentaram alterações morfológicas bi e tridimensionais após o preparo biomecânico. O emprego do sistema ProGlider previamente aos sistemas de instrumentação não influenciou as alterações dos parâmetros avaliados. / The present study aimed to analyze, by computerized microtomography, the morphological parameters of mesial roots of mandibular molars prepared by three mechanized systems: reciprocating (Reciproc - RC), continuous rotating (OneShape - OS) and Twisted - File Adaptive (TFA), preceded or not by pre - enlargement (ProGlider-PG). Thirty teeth were used, with mesial root presenting severe angle (≥25º) and a radius of curvature (≤2mm) and two distinct canals. By means of the stratified sampling technique, the canals were distributed in six groups (n = 10) according to the instrumentation protocol: G1-TFA; G2-RC; G3-OS; G4-PG + TFA; G5 - PG + RC; G6- PG + OS. After preparation, the two-dimensional parameters (area, perimeter, roundness, major and minor diameter) were evaluated in the apical 5mm as well as three-dimensional parameters (volume, surface area and SMI) and root canal transportation. The data were statistically analyzed using the ANOVA test followed by Tukey\'s complement (α = 0.05). The RC presented significantly larger values of area, perimeter, and minor diameter in relation to the TFA (p<0,001), and there was no significant difference between the systems in relation to the roundness (p=0,056) and major diameter (p=0,477). The increased canal volume provided by the RC and the OS systems were similar to each other (p=0,979) and statistically different from the TFA (p<0,001). The increase of the surface area promoted by the RC was similar to the OS (p=0,254) and statistically different to the TFA (p=0,001), with no difference between the other two systems (p=0,075). The SMI values of the PG + OS group were significantly higher than the other groups (p<0,001). There was no difference between the systems in relation to transport in the apical and middle thirds. It was concluded that all evaluated systems presented bi-dimensional and three-dimensional morphological alterations after biomechanical preparation. The use of the ProGlider system prior to the instrumentation systems did not influence the parameters evaluated.
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Guide tubes for ultracold neutronsAl-Ayoubi, Samer January 2001 (has links)
No description available.
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Continuous-time quantum Monte Carlo studies of lattice polaronsSpencer, Paul E. January 2000 (has links)
The polaron problem is studied, on an infinite lattice, using the continuous-time path-integral quantum Monte Carlo scheme The method is based on the Feynman technique to analytically integrate out the phonon degrees of freedom. The transformed problem is that of a single electron with retarded self-interaction in imaginary time. The Metropolis algorithm is used to sample an ensemble of electron trajectories with twisted (rather than periodic) boundary conditions in imaginary time, which allows dynamic properties of the system to by measured directly. The method is numerically "exact", in the sense that there are no systematic errors due to finite system size, trotter decomposition or finite temperature The implementation of the algorithm in continuous imaginary time dramatically increases computational efficiency compared with the traditional discrete imaginary time algorithms.
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A computer simulation study of tilted smectic mesophasesWithers, Ian Michael January 2000 (has links)
Results are presented from a series of simulations undertaken to determine the effect of a novel form of molecular biaxiality upon the phase behaviour of the well established Gay-Berne (GB) liquid crystal model. Firstly, the simulation of a bulk system interacting via the Internally-Rotated Gay-Berne (IRGB) potential, which offers a single-site representation of a molecule rigidly constrained into a zig-zag conformation, is presented. The results of simulations performed for systems of IRGB particles with an aspect ratio of 3:1 confirm that the introduction of biaxiality into the model results in the destabilisation of the orientationally ordered phases. For particles with a sufficiently pronounced zig-zag conformation, this results in the complete destabilisation of the smectic A phase and the smectic B phase being replaced by the tilted smectic J phase. Following these observations, the effect upon the phase behaviour of increasing molecular elongation is also considered, with an increase in the aspect ratio from 3:1 to 4:1 resulting in the nematic and smectic J phases being replaced by smectic A and smectic G phases respectively. Secondly, a version of the IRGB potential modified to include a degree of molecular flexibility is considered. Results obtained from bulk systems interacting via the flexible IRGB for 3:1 and 4:1 molecules show that the introduction of flexibility results in the destabilisation of the smectic A phase and the stabilisation of the nematic and tilted hexatic phases. Finally, the effect upon the phase behaviour of the rigid IRGB model of the inclusion of a longitudinal linear quadrupole is examined. These results show that increasing quadrupole moment results in the destabilisation of the tilted hexatic phase, although the biaxial order parameter is increased with increasing quadrupole moment. There is no clear correlation between quadrupole magnitude and the other observed phase transitions, with the nematic and smectic A phases being variously stabilised and destabilised with increasing quadrupole magnitude. For the 4:1 molecules with large quadrupole moments, buckled smectic layers are observed where some molecules are tilted with respect to a local layer normal. Of all the systems considered here, this buckled structure is the one which most closely resembles the elusive smectic C phase.
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Desenvolvimento e implantação de um sistema de planejamento e controle da manutenção informatizado em uma instituição de ensino superiorKlein, João Jorge January 2007 (has links)
Com o intuito de mudar a situação em que se encontra a manutenção na UFRGS, de defasagem e dificuldades de ordens diversas, é elaborada uma proposta de construção de uma política de manutenção para a Instituição, a partir da qual, apresenta-se um plano de desenvolvimento e implantação de um Sistema de Planejamento e Controle da Manutenção Informatizado, criando as condições necessárias à Gestão da Manutenção. Neste contexto, no presente trabalho, realiza-se uma revisão bibliográfica sobre o tema, um estudo da manutenção no Brasil e a concepção de um Sistema de Planejamento e Controle da Manutenção na Instituição, iniciado com um diagnóstico dos problemas operacionais encontrados. As questões consideradas mais críticas detectadas foram: inexistência de recursos humanos capacitados e de uma estrutura de gestão definida, infra-estrutura inadequada para o desenvolvimento das tarefas, falta de uma política de manutenção e de investimentos nas instalações, equipamentos e treinamento. Constatação de falta de documentação e histórico dos serviços realizados e de ferramentas ou software de planejamento e controle da manutenção, resistência passiva dos trabalhadores a mudanças, necessidade de alterações nas rotinas das atividades e demora no atendimento das solicitações. As medidas corretivas adotadas para a solução dos problemas identificados foram implantadas no período de dois anos e continuam com novas etapas ainda por executar numa estimativa de quatro anos para sua consolidação. Os principais resultados obtidos, até o momento, foram a definição e implantação da política de Manutenção – “Manutenção Criativa”, aumento da capacidade e a melhora na qualidade de atendimento das solicitações de serviços suportado por um sistema informatizado, um controle mais eficaz dos serviços e das informações da manutenção e o seu acompanhamento em tempo real, o início do gerenciamento da manutenção pelas ferramentas disponibilizadas. Também se constata uma mudança no comportamento dos trabalhadores passando a uma conduta mais participativa e com menor resistência às mudanças. / With the intention of changing the actual maintenance at UFRGS – one of discrepancy and difficulties of several orders, a proposal for constructing a maintenance politics is elaborated for the Institution, starting from which derives a plan for the development and implantation of a Computerized Planning and Controlling Maintenance System, creating the necessary conditions to the Maintenance Management. In this context, in the present work, take place a bibliographical revision on the theme, a study of the maintenance in Brazil and the conception of the institution’s Maintenance Planning and Controlling System, started with a diagnosis of the found operational problems. The most critic issues detected were: the absence of qualified human resources and of a defined structure management, an inadequate infrastructure for development of the tasks, lacks of a maintenance politics and of investments in the facilities, equipments and training. Verification of documentation lack and historical of the accomplished services and absence of tools or soft wares of Planning and Controlling Maintenance, passive resistance of the workers to changes, need of alterations in the routines of the activities and delay in the service of the requests. The corrective actions adopted for the solution of the identified problems were implanted in the period of two years and continue with new stages still for executing in a four year-old estimate for its consolidation. The main obtained results, until the moment, they were the definition and implantation of the politics of Maintenance-“Creative Maintenance”, an increase of the capacity and the improvement in the quality of service of the requests of services supported by a computerized system, a more effective control of the services and the information of the maintenance its availability in real time, the beginning of the maintenance management for the made available tools. Also a change is verified in the workers' behavior passing to a conduct more participative and with smaller resistance to the changes.
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A efetividade de feedbacks informatizados sobre a autoregulação da aprendizagem em cursos a distância : um estudo de caso na área da computaçãoMáximo, Luis Fernando January 2009 (has links)
O objetivo desta Tese é analisar a efetividade de feedbacks informatizados sobre a auto-regulação da aprendizagem em um de curso superior a distância na área de Computação. A análise se deu a partir do desenvolvimento de um estudo de caso. O caso estudado constituiu-se da observação de registros provenientes da interação de alunos com uma ferramenta para a exercitação da construção de algoritmos em um curso superior de Tecnologia em Análise e Desenvolvimento de Sistemas a distância. Comparamos os registros de feedbacks fornecidos pela ferramenta com o alcance do objetivo do aluno em construir um algoritmo sem erros de sintaxe verificados em tempo de execução. Conjuntamente analisamos o projeto pedagógico do curso que, à época deste estudo, atendia aproximadamente cinco mil alunos dispersos no território nacional. Para a análise e a discussão dos dados coletados foi construída uma fundamentação teórica tratando sobre educação a distância, avaliação e mediação da aprendizagem. A partir dos resultados de testes estatísticos de significância e correlação analisamos, dentro das condições de comunicação, estrutura e autonomia do curso, a efetividade dos feedbacks informatizados sobre a auto-regulação da aprendizagem dos alunos. Entre os principais resultados destacamos a constatação de que os feedbacks informatizados apresentam forte correlação com a auto-regulação da aprendizagem, no entanto, não podem ser apontados como causa direta de tal auto-regulação. Esperamos que esta Tese possa contribuir para a criação de recursos e sistemas informatizados capazes de ajudar estudantes a assumirem papéis mais ativos e determinantes nos seus próprios processos de aprendizagem, sobretudo, em cursos a distância. / The aim of this Thesis is analyzing the effectiveness of computerized feedback on self-regulation of learning in a distance education course of computation. The analysis was developed from a case study. The case study was developed from the observation of the students interactions with a tool for algorithms construction in a distance education course of Technology in Development and Systems Analysis. The records of feedback provided by the tool were compared with the reach of the student's goal in construct an algorithm with no runtime syntax errors. It was analyzed too the pedagogical project of the course that at the time of this study had approximately five thousand students scattered in the national territory. For analysis and discussion of the collected data was built a theoretical basis addressing distance education, assessment and mediation of learning. From the results of statistical tests of significance and correlation we analyzed within the conditions of communication, structure and autonomy of the course, the effectiveness of computerized feedback on self-regulation of students' learning. Among the key findings highlight the fact that the feedback systems have strong correlation with self-regulation of learning, however, can not be described as direct cause of such self-regulation. We hope that this thesis may contribute to the creation of resources and systems capable of helping students to take more active and decisive roles in their own learning processes especially in the distance courses.
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