14 resultados para light harvesting complex EPR monomer trimer structural analysis
Correlating EPR and X-ray structural analysis of arsenite-inhibited forms of aldehyde oxidoreductase
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J Biol Inorg Chem (2007) 12:353–366 DOI 10.1007/s00775-006-0191-9
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Nature has developed strategies to present us with a wide variety of colours, from the green of leaves to the bright colours seen in flowers. Anthocyanins are between these natural pigments that are responsible for the great diversity of colours seen in flowers and fruits. Anthocyanins have been used to sensitize titanium dioxide (TiO2) in Dye-Sensitized Solar Cells (DSSCs). DSSCs have become one of the most popular research topic in photovoltaic cells due to their low production costs when compared to other alternatives. DSSCs are inspired in what happens in nature during photosynthesis. A primary charge separation is achieved by means of a photoexcited dye capable of performing the electron injection into the conduction band of a wide band-gap semiconductor, usually TiO2. With this work we aimed to synthesize a novel mesoporous TiO2 structure as the semiconductor in order to increase the dye loading. We used natural occurring dyes such as anthocyanins and their synthetic flavylium relatives, as an alternative to the widely used metal complexes of Ru(II) which are expensive and are environmentally unsafe. This offers not only the chance to use safer dyes for DSSCs, but also to take profit of waste biological products, such as wine and olive oil production residues that are heavily loaded with anthocyanin dyes. We also performed a photodegradation study using TiO2 as the catalyst to degrade dye contaminants, such as those from the wine production waste, by photo-irradiation of the system in the visible region of the light spectrum. We were able to succeed in the synthesis of mesoporous TiO2 both powder and thin film, with a high capacity to load a large amount of dye. We proved the concept of photodegradation using TiO2 as catalyst. And finally, we show that wine production waste is a possible dye source to DSSCs application.
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Cell division is a highly dynamic process where sister chromatids remain associated with each other from the moment of DNA replication until the later stages of mitosis, giving rise to two daughter cells with equal genomes. The “molecular glue” that links sister DNA molecules is called cohesin, a tripartite ring-like protein complex composed of two Structural Maintenance of Chromosome proteins (Smc1 and Smc3) bridged by a kleisin subunit Rad21/Scc1, that together prevent precocious sister chromatid separation. Accumulating evidence has suggested that cohesion decay may be the cause of segregation errors that underlie certain human pathologies. However it remains to be determined how much cohesin loss abolishes functional sister chromatid cohesion. To answer these questions, we have developed different experimental conditions aiming to titrate the levels of cohesin on mitotic chromosomes in a precise manner. Using these tools, we will determine the minimal amount of cohesin needed to confer functional cohesion. The approaches described here take advantage of a system in Drosophila melanogaster where the Tobacco Etch Virus (TEV) protease can cleave the Rad21 subunit of cohesin leading to precocious sister chromatid separation. Firstly, we tried to express different levels of TEV protease to obtain partial loss of cohesion. However, this approach has failed to produce systematic different levels of sister chromatid separation. Most of the work was therefore focused on a second strategy, for which we established strains with different levels of cohesin sensitive/cohesin resistant to TEV protease. Strains containing different amounts of functional cohesin (TEV resistant) were tested by in vitro cleavage and by in vivo injections in embryos for their ability to promote sister chromatid cohesion. Our results reveal that removal of half of the cohesin complexes does not impair chromosome segregation, implying that chromosome cohesion is less sensitive to cohesin amounts than previously anticipated.
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Dissertação para obtenção do Grau de Doutor em Ciências da Educação Especialidade em Tecnologias, Redes e Multimédia na Educação e Formação
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Ion Mobility Spectrometry coupled with Multi Capillary Columns (MCC -IMS) is a fast analytical technique working at atmospheric pressure with high sensitivity and selectivity making it suitable for the analysis of complex biological matrices. MCC-IMS analysis generates its information through a 3D spectrum with peaks, corresponding to each of the substances detected, providing quantitative and qualitative information. Sometimes peaks of different substances overlap, making the quantification of substances present in the biological matrices a difficult process. In the present work we use peaks of isoprene and acetone as a model for this problem. These two volatile organic compounds (VOCs) that when detected by MCC-IMS produce two overlapping peaks. In this work it’s proposed an algorithm to identify and quantify these two peaks. This algorithm uses image processing techniques to treat the spectra and to detect the position of the peaks, and then fits the data to a custom model in order to separate the peaks. Once the peaks are separated it calculates the contribution of each peak to the data.
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The growing need to patrol and survey large maritime and terrestrial areas increased the need to integrate external sensors on aircraft in order to accomplish those patrols at increasingly higher altitudes, longer range and not depending upon vehicle type. The main focus of this work is to elaborate a practical, simple, effective and efficient methodology for the aircraft modification procedure resulting from the integration of an Elec-tro-Optical/Infra-Red (EO/IR) turret through a support structure. The importance of the devel-opment of a good methodology relies on the correct management of project variables as time, available resources and project complexity. The key is to deliver a proper tool for a project de-sign team that will be used to create a solution that fulfils all technical, non-technical and certi-fication requirements present in this field of transportation. The created methodology is inde-pendent of two main inputs: sensor model and aircraft model definition, and therefore it is in-tended to deliver the results for different projects besides the one that was presented in this work as a case study. This particular case study presents the development of a structure support for FLIR STAR SAPHIRE III turret integration on the front lower fuselage bulkhead (radome) of the LOCKHEED MARTIN C-130 H. Development of the case study focuses on the study of local structural analysis through the use of Finite Element Method (FEM). Development of this Dissertation resulted in a cooperation between Faculty of Science and Technology - Universidade Nova de Lisboa and the company OGMA - Indústria Aeronáutica de Portugal
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The thesis is divided into two parts corresponding to structural studies on two different proteins. The first part concerns the study of two UDP-glucose dehydrogenases (UGDs) from Sphingomonas elodea ATCC 31461 and Burkholderia cepacia IST 408, both involved in exopolysaccharide production. Their relevance arises because some of these bacterial exopolysaccharides are valuable as established biotechnological products, the former case, whilst others are highly problematic, when used by pathogens in biofilm formation over biological surfaces, as the latter case, namely in the human lungs. The goal of these studies is to increase our knowledge regarding UGDs structural properties, which can potentiate either the design of activity enhancers to respond to the increased demand of useful biofilms, or the design of inhibitors of biofilm production, in order to fight invading pathogens present in several infections. The thesis reports the production and crystallisation of both proteins, the determination of initial phases by single-wavelength anomalous dispersion (SAD) in S. elodea crystals using a seleno-methionine isoform, and phasing of B. cepacia crystals by molecular replacement (MR) using the S. elodea model, as well as the refinement, structural analysis and comparison between the several UGDs structures available during this work.(...)
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Mecânica Especialização em Concepção e Produção
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em BioOrgânica
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Dissertation for the Master Degree in Structural and Functional Biochemistry
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Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica
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RESUMO: Introdução: A integração da saúde mental (SM) na atenção primária (AP) é a principal garantia de acesso da população às boas práticas em SM. Embora amplamente recomendada há décadas, existem poucos modelos de integração efetiva da SM na AP. Em 2008 o Ministério da Saúde do Brasil criou o Núcleo de Apoio à Saúde da Família (NASF), que passou a ser o responsável pela integração da SM na AP. O objetivo deste estudo é conhecer, a partir da ótica dos gerentes da AP, como se dá a integração da SM na AP, suas visões sobre o NASF e sugestões para melhorar este modelo de integração. A partir dos resultados apresentaremos recomendações para aperfeiçoar o modelo vigente de integração da SM na AP. Método: Pesquisa qualitativa, de caráter exploratório, com orientação analítica – descritiva. Foram realizadas 10 entrevistas semi-estruturadas com gerentes da AP, na região metropolitana de São Paulo. Trabalhou-se com o conceito de amostragem intencional, utilizando como critério de escolha os casos extremos ou desviantes. Foi utilizado o método da Análise Estrutural ou Framework Analysis, uma modalidade de análise de conteúdo. Resultados: Os entrevistados consideraram haver mais barreiras do que facilitadores à integração da SM na AP. As barreiras e facilitadores apresentados estavam relacionados ao contexto social, fatores organizacionais, e componentes pessoais das equipes de trabalhadores. Os gerentes mostram não ter clareza sobre como operacionalizar suas ideias sobre integração da SM na AP e sobre o escopo das intervenções da SM na AP. Na visão dos gerentes a atuação do NASF ainda é incapaz de promover o cuidado integrado. Conclusões: A maior dificuldade não é criar a política de integração da SM na AP, mas viabilizar sua implementação. Recomenda-se aperfeiçoamento do processo de trabalho do NASF e investigações sobre a natureza e exequibilidade do apoio matricial no contexto da AP.--------------ABSTRACT: Introduction: The integration of mental health (MH) in primary care (PC) is the main guarantee of access to good practices in MH. Although widely recommended for decades, there are few models of effective integration of MH in PC. In 2008 the Brazilian Ministry of Health created the Core of Support for the Family Health Strategy (NASF), to be the responsible for the integration of MH in PC. This study aims understanding the PC manager’s perspective about the integration of MH in PC, their visions about the NASF and their suggestions to improve this model of integrated care. Based on results we will present recommendations to improve NASF’s model of integration MH in PC. Method: Qualitative research, exploratory and analytical descriptive study. We conducted 10 semi-structured interviews with PC managers, in the metropolitan region of Sao Paulo. We worked with the concept of intentional sampling, using as a criterion for choosing the extreme or deviant cases. We used the Framework Analysis methodological approach, a method of contente analysis. Results: The interviewees considered that there are more barriers than facilitators for the integration of MH in PC. The barriers and facilitators presented were related to the social context,organizational factors, and personal component of the PC staff. Managers’ shows not have clarity about how implement their ideas about integration of MH in PC and about the scope of the interventions of MH in PC. The NASF is still unable to promote the integrated care in managers perception. Conclusions: The biggest difficulty is not to create a policy of integration of MH in PC, but its implementation. It is recommended to improve the NASF work process and to research about the nature and feasibility of matrix support in the context of PC.
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The theme of this dissertation is the finite element method applied to mechanical structures. A new finite element program is developed that, besides executing different types of structural analysis, also allows the calculation of the derivatives of structural performances using the continuum method of design sensitivities analysis, with the purpose of allowing, in combination with the mathematical programming algorithms found in the commercial software MATLAB, to solve structural optimization problems. The program is called EFFECT – Efficient Finite Element Code. The object-oriented programming paradigm and specifically the C ++ programming language are used for program development. The main objective of this dissertation is to design EFFECT so that it can constitute, in this stage of development, the foundation for a program with analysis capacities similar to other open source finite element programs. In this first stage, 6 elements are implemented for linear analysis: 2-dimensional truss (Truss2D), 3-dimensional truss (Truss3D), 2-dimensional beam (Beam2D), 3-dimensional beam (Beam3D), triangular shell element (Shell3Node) and quadrilateral shell element (Shell4Node). The shell elements combine two distinct elements, one for simulating the membrane behavior and the other to simulate the plate bending behavior. The non-linear analysis capability is also developed, combining the corotational formulation with the Newton-Raphson iterative method, but at this stage is only avaiable to solve problems modeled with Beam2D elements subject to large displacements and rotations, called nonlinear geometric problems. The design sensitivity analysis capability is implemented in two elements, Truss2D and Beam2D, where are included the procedures and the analytic expressions for calculating derivatives of displacements, stress and volume performances with respect to 5 different design variables types. Finally, a set of test examples were created to validate the accuracy and consistency of the result obtained from EFFECT, by comparing them with results published in the literature or obtained with the ANSYS commercial finite element code.
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The airport pavement deteriorates during service due to traffic and climate effects therefore systematic monitoring is required in order to assess their structural and functional condition. The aim of this work is to present the methodologies used nowadays for airport pavement evaluation and to contribute to their improvement in structural analysis area The main aspects that are addressed are the application of the Ground Penetrating Radar (GPR) and the use of the Falling Weight Deflectometer (FWD) tests, for structural evaluation, and the use of the GRIP tester and the measurement of texture depth of the wearing course layer, for the functional evaluation of the runway. Also, freeware computer softwares used to design new runways (FAARFIELD and COMFAA) are presented and examples are given. Case studies are described both for structural and functional evaluation.