Submitted by Renata Lopes (renatasil82@gmail.com) on 2018-02-28T14:32:12Z No. of bitstreams: 1 marianeflorianolopessantoslacerda.pdf: 10232685 bytes, checksum: 43a6424d223e0874ce221a2e6565b3ef (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-03-01T15:58:28Z (GMT) No. of bitstreams: 1 marianeflorianolopessantoslacerda.pdf: 10232685 bytes, checksum: 43a6424d223e0874ce221a2e6565b3ef (MD5) / Made available in DSpace on 2018-03-01T15:58:28Z (GMT). No. of bitstreams: 1 marianeflorianolopessantoslacerda.pdf: 10232685 bytes, checksum: 43a6424d223e0874ce221a2e6565b3ef (MD5) Previous issue date: 2017-03-31 / PROQUALI (UFJF) / Objetivos: O presente estudo se propôs a avaliar a limpeza e modelagem de canais ovais após preparo com 3 sistemas de instrumentação usando correlação entre método analíticos. Materiais e métodos: Raízes distais de molares inferiores com canais ovais e vitalidade pulpar foram inicialmente escaneadas por microtomografia computadorizada (micro-CT) para seleção e distribuição das amostras em três grupos experimentais de acordo com o instrumento a ser avaliado: selfadjusting files (SAF), TRUShape e XP-endo Shaper. Em todos os grupos, hipoclorito de sódio a 5,25% aquecido a 37°C foi o irrigante. Após novo escaneamento em micro-CT, as áreas não tocadas das paredes do canal foram calculadas e, em seguida, avaliadas histologicamente quanto à quantidade de remanescente pulpar nos terços radiculares. Resultados: A 4mm do ápice, SAF apresentou valor significativamente menor de paredes não tocadas em relação ao XP-endo Shaper (P<0,049). Não foi possível verificar diferença estatística a 10 mm do ápice (P>0,05). A quantidade de remanescentes pulpares não apresentou diferença significativa entre os instrumentos, em nenhum dos terços avaliados. Não houve correlação significativa entre área não tocada e remanescente pulpar para os instrumentos testados. Conclusão: Não houve diferença no percentual de paredes não tocadas entre os 3 grupos, exceto entre SAF e XP-endo Shaper na avaliação dos 4 mm apicais. Também não houve diferença significativa na limpeza das paredes não tocadas. A não correlação entre paredes não tocadas e a quantidade de remanescentes pulpares indica a eficácia do preparo químico-mecânico com hipoclorito de sódio como irrigante na eliminação de matéria orgânica sobre as paredes. / Purpose: The present study evaluated the cleaning and shaping ability of three instrumentation systems in oval canals of vital teeth using a correlative analytical approach. Materials and methods: Distal roots of oval canals with pulp vitality were scanned by computed microtomography (micro-CT) for sample selection and distribution into three experimental groups according to the instrument to be evaluated: self-adjusting files (SAF), TRUShape and XP-endo Shaper. In all groups, the irrigant was sodium hypochlorite (5.25%) heated at 37°C. After rescanning by micro-CT, the untouched walls were measured and then histologically evaluated for the amount of pulp remaining in the root thirds. Results: SAF was more effective in touching the walls at 4 mm from the apex, presenting a significantly lower value of untouched walls when compared to XPendo Shaper (P <0.049). However, it was not possible to verify significant differences in the full canal length between groups. The amount of pulp remnants also did not differ between instruments in the canal thirds. There was no significant correlation between untouched areas and pulp remnants for any instrument. Conclusion: There was no significant difference in the amount of untouched walls between instruments, except between SAF and XP-endo Shaper in the apical 4 mm. There was no significant difference in the cleaning ability either. The non-correlation between untouched walls and pulp remnants indicates the effectiveness of different instruments and sodium hypochlorite irrigation in the elimination of soft tissue from unprepared walls.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2018-11-22T11:04:41Z No. of bitstreams: 1 maraisaaparecidapintoresende.pdf: 6162684 bytes, checksum: 81f875f5effd371befe15f0ee40da393 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-11-23T12:58:47Z (GMT) No. of bitstreams: 1 maraisaaparecidapintoresende.pdf: 6162684 bytes, checksum: 81f875f5effd371befe15f0ee40da393 (MD5) / Made available in DSpace on 2018-11-23T12:58:47Z (GMT). No. of bitstreams: 1 maraisaaparecidapintoresende.pdf: 6162684 bytes, checksum: 81f875f5effd371befe15f0ee40da393 (MD5) Previous issue date: 2018-09-19 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo deste estudo clínico controlado randomizado microtomográfico foi comparar a qualidade óssea entre dois métodos diferentes de preservação do rebordo alveolar e avaliar as estabilidades primária e secundária dos implantes instalados nessas regiões. Vinte pacientes foram divididos aleatoriamente em dois grupos de tratamento após uma única extração dentária. Dez alvéolos foram enxertados com fosfato de cálcio bifásico (SBC, n = 10) associado a um retalho de tecido conjuntivo subepitelial pediculado para o fechamento primário. Dez alvéolos foram selados com uma restauração provisória de pôntico ovóide (PROV, n = 10) sem material de enxertia. Após 12 meses, 9 pacientes perderam-se no acompanhamento e 11 pacientes receberam implantes dentários. As biópsias ósseas foram avaliadas por microtomografia computadorizada (8 μm), quanto às características do osso trabecular. Valores de torque de inserção (ITV) e quociente inicial de estabilidade do implante (ISQI) foram registrados no momento da instalação dos implantes. O ISQ também foi registrado aos 7 dias, 30 dias e 60 dias pós-operatórios. Todos os onze pacientes tiveram os implantes osseointegrados sem intercorrências. O grupo PROV apresentou trabéculas mais espessas (0,17 ± 0,03) em relação ao grupo SBC (0,11 ± 0,03) (p = 0,03). O osso trabecular foi mais anisotrópico em PROV (0,3 ± 0,08) comparado com SBC (0,1 ± 0,07) (p = 0,01). O grupo PROV apresentou menor superfície óssea (26,02 ± 10,36) que o grupo SBC (40,09 ± 10,94) (p = 0,05). Além disso, o PROV apresentou ISQ inicial mais alto (72,3 ± 21) em comparação com o SBC (67 ± 3,9) (p = 0,05). O osso trabecular revelou diferenças na microarquitetura entre os dois métodos de preservação do rebordo alveolar e ambos os métodos foram satisfatórios para a instalação do implante e resultaram em altos valores de ITV e ISQ. / This randomized controlled clinical microtomographic trial aimed to compare the bone quality between two different methods of alveolar ridge preservation and to evaluate the primary and secondary implant stability. Twenty patients were randomly divided into two groups following a single tooth extraction: SBC group (n=10), sockets were grafted with alloplastic biphasic calcium phosphate and a pedicle subepithelial connective tissue flap was used for primary closure; and PROV group (n=10), sockets were sealed with an ovate pontic provisional restoration. After 12 months, 11 patients received dental implants, with nine patients lost to follow-up. Bone biopsies were evaluated by microcomputed-tomography (8 μm) to determine cancellous bone characteristics. Insertion torque values (ITV) and initial implant stability quotient (ISQI) were recorded at installation. The ISQ was also recorded 7, 30 and 60 days after the implant was installed. All implants showed uneventful osseointegration. The PROV group presented thicker trabeculae (0.17±0.03) compared to the SBC group (0.11±0.03; p 0.03). Trabeculae bone was more anisotropic in the PROV group (0.3±0.08) compared with the SBC group (0.1±0.07; p 0.01). The PROV group presented less bone surface (26.02±10.36) than the SBC group (40.09±10.94; p 0.05). Also, PROV showed higher ISQI (72.3±21) than SBC (67±3.9; p 0.05). The characteristics of the trabecular bone differed between the two alveolar ridge preservation methods and the both preservation methods gave satisfactory results with regard to implant placement, and both resulted in high values for ITV and ISQ.

In recent years, automated mineralogy has become an essential tool in geometallurgy. Automated mineralogical tools allow the acquisition of mineralogical and liberation data of ore particles in a sample. These particle data can then be used further for particle-based mineral processing simulation in the context of geometallurgy. However, most automated mineralogical tools currently in application are based on two-dimensional (2D) microscopy analysis, which are subject to stereological error when analyzing three-dimensional(3D) object such as ore particles. Recent advancements in X-ray microcomputed tomography (µCT) have indicated great potential of such system to be the next automated mineralogical tool. µCT's main advantage lies on its ability in monitoring 3D internal structure of the ore at resolutions down to few microns, eliminating stereological error obtained from 2D analysis. Aided with the continuous developments of computing capability of 3D data, it is only the question of time that µCT system becomes an interesting alternative in automated mineralogy system. This study aims to evaluate the potential of implementing µCT as an automated mineralogical tool in the context of geometallurgy. First, a brief introduction about the role of automated mineralogy in geometallurgy is presented. Then, the development of µCT system to become an automated mineralogical tool in the context of geometallurgy andprocess mineralogy is discussed (Paper 1). The discussion also reviews the available data analysis methods in extracting ore properties (size, mineralogy, texture) from the 3D µCT image (Paper 2). Based on the review, it was found that the main challenge inperforming µCT analysis of ore samples is the difficulties associated to the segmentation of the mineral phases in the dataset. This challenge is adressed through the implementation of machine learning techniques using Scanning Electron Microscope (SEM) data as a reference to differentiate the mineral phases in the µCT dataset (Paper 3).

[pt] A lapidação é uma técnica que estabelece a melhor estratégia de corte, isto é, aquela que extrai do volume bruto a maior gema lapidada com o maior valor gemológico. O profissional, a partir de seu conhecimento tácito, observa as configurações únicas de cada gema, identificando a presença e o posicionamento de estruturas como inclusões, trincas e clivagens, assim como zonas e bandas de cor, aspectos que impactam o valor de mercado do produto. O resultado desta observação é inconstante, já que a tarefa é realizada a partir do conhecimento e experiência dos profissionais, que varia de um indivíduo para outro. Neste sentido, propõe-se uma ferramenta auxiliar ao projeto de lapidação: a virtualização da observação de gemas de alto valor gemológico e do posicionamento da pré-forma em seu interior. Uma revisão bibliográfica dos requisitos técnicos e tecnológicos da lapidação é apresentada, assim como foram descritas e comparadas tecnologias para a digitalização e análise de estruturas tridimensionais. As informações reunidas nortearam uma pesquisa experimental, iniciada pela digitalização da morfologia interna e externa de três amostras de topázio imperial por microtomografia computadorizada e processamento digital de imagens. A manipulação interativa de uma pré-forma parametrizada viabiliza a mensuração da quantidade de material desperdiçado durante a formatação, ao mesmo tempo em que estabelece as dimensões básicas do volume aproveitável. Tais dados viabilizam a criação de opções de projetos de facetamento em softwares para este fim, preservando o material até que o corte ideal seja estabelecido, o que é estratégico para materiais de alto valor gemológico. O erro do volume digitalizado foi de 0,1179. Este índice foi obtido comparando o volume digital ao aferido por balança hidrostática de sua amostra real. Uma inspeção visual com especialista avaliou que a superfície externa das gemas é fidedigna à sua digitalização, com exceção das áreas de topo e daquelas que estão em contato com os porta-amostras. Ainda assim, os problemas identificados não são relevantes, já que lapidadores comumente desprezam as partes mencionadas já no início da conformação. O tamanho mínimo do pixel atingido pelos exames de microtomografia foi de 1.3350 um, impedindo que estruturas de menor dimensão fossem capturadas. / [en] Gem cutting is a technique that establishes the best cutting strategy, which can be described as the extraction of the largest gemstone with the highest gemological value from the rough volume. Professionals observe the unique configurations of each gem based on his or her tacit knowledge and identify the position of structures, such as inclusions, cracks, and cleavages, as well as color zoning, which are aspects that impact product market value. The results of these observations are inconstant since the task is carried out based on the knowledge and experience of the professionals, which vary from one individual to another. Thus, an auxiliary tool for gemstone cutting projects is proposed that virtualizes the processes of observing high gemological value gemstones and their preform positioning. A bibliographical review of the technical and technological requirements of lapidary cutting is presented, as well as a description of suitable technologies for three-dimensional digitization and analysis. The gathered information guided an experimental research study, which started by acquiring the internal and external morphology of three imperial topaz samples using computerized microtomography and digital image processing. The interactive manipulation of a parameterized preform allows the amount of wasted material during the preforming phase to be measured, thus concurrently establishing the basic dimensions of a mass suitable for cutting. Such data enables the creation of several faceting projects on the software that preserves the material until the ideal cut is established, which is a beneficial strategy for high gemological value materials. The digitized volume error was 0.1179. This index was obtained by comparing the digital volume of the material to the volume of its physical sample as measured by a hydrostatic scale. A specialist completed a visual inspection that evaluated the outer surface of the gem and determined that it was a reliable cut except for the top areas and those that were in contact with the specimen holders. Nevertheless, the identified problems are not relevant since gem cutters commonly disregard the mentioned areas at the beginning of gemstone conformation. The minimum pixel size reached by microtomography analysis was 1.3350 um, which prevented smaller structures from being captured.

O preparo químico-cirúrgico é uma das etapas mais importantes do tratamento endodôntico, pois promove a desinfecção do sistema de canais radiculares através da limpeza e da modelagem. Realizar o preparo de canais curvos é um grande desafio, devido à ocorrência freqüente de acidentes operatórios como o transporte do canal. A introdução de instrumentos fabricados em ligas de níquel-titânio (NiTi) contribuiu consideravelmente para a melhora na qualidade da instrumentação dos canais. Os diferentes sistemas rotatórios que são apresentados continuamente ao profissional devem ser estudados com detalhes, pois o seu comportamento pode variar de acordo com o desenho de cada instrumento e as suas características de produção. O objetivo deste estudo foi avaliar, ex vivo, a qualidade do preparo de canais curvos realizado pelos sistemas rotatórios Twisted File (TF; Sybron Endo), torcidos, e EndoSequence (ES; Brasseler), usinados, quanto à habilidade em manter o canal centralizado, analisando a extensão e a direção dos eventuais transportes e o índice de centralização do instrumento (IC), por meio de cortes transversais e da microtomografia computadorizada (CT). Trinta molares inferiores foram divididos em dois grupos, e preparados conforme o delineamento de cada método: G1 - Bramante Modificado e G2 - CT. No G1, os dentes foram incluídos em blocos de resina, e seccionados a 2,0, 3,5 e 5,0 mm do ápice radicular. As secções foram fotografadas, e os blocos, remontados, foram submetidos à instrumentação rotatória. No G2, os dentes foram incluídos em material de moldagem e escaneados com um microtomógrafo, antes e após o preparo. As imagens das seções transversais foram reconstruídas e os cortes axiais correspondentes às distâncias de 2,0, 3,5 e 5,0 mm do ápice radicular foram selecionados. Os resultados foram submetidos ao teste estatístico não-paramétrico Mann-Whitney, para comparações duas a duas. Em ambos os grupos, o transporte do canal e o IC para os sistemas TF e ES foram semelhantes, havendo diferença estatística significante apenas no G2, na secção 3,5 mm, quando o sistema TF causou menos transporte do que o sistema ES, obtendo também um melhor IC (p < 0,05). Quando realizada a comparação entre os métodos, independentemente do instrumento utilizado, o transporte do canal foi significantemente menor (0,17 mm) no grupo 2, do que no grupo 1 (0,27 mm) (p < 0,05). A 3,5 e 5,0 mm, o sistema TF promoveu menos transporte no grupo 2 do que no grupo 1 (p < 0,05). Para o sistema ES, diferença estatística foi encontrada a 2,0 mm, aonde o transporte também foi menor no grupo 2 (p < 0,05). Concluiu-se que os sistemas TF e ES se comportaram de modo semelhante quanto ao transporte do canal e ao IC, permitindo o preparo de canais curvos com pouco desvio. Os dois instrumentos apresentaram desvios tanto para o sentido mesial, quanto para o sentido distal. E quando comparados apenas os métodos de avaliação, no método da CT o transporte do canal foi menor do que no método de Bramante Modificado. / The chemomechanical preparation is one of the most important phases of endodontic treatment, because it promotes disinfection of the root canal system by cleaning and shaping. The preparation of curved canals is a major challenge due to the frequent occurrence of operative accidents as the canal transportation. The introduction of instruments of nickel-titanium (NiTi) alloy has contributed considerably to the improvement of canal instrumentation quality. The different rotary systems that are continuously presented to dental professionals should be studied in detail, because their mechanical properties can vary according to the design of each instrument and the manufacture characteristics. The aim of this study was to evaluate, ex vivo, the quality of preparation of curved canals and centering ability of the rotary systems Twisted File (TF) (Sybron Endo), twisted, and EndoSequence (ES) (Brasseler), ground, analyzing the extent and direction of any transportation and the centering ratio of instrument, by cross sections and microcomputed tomography (CT). Thirty lower molars were divided into two groups, and prepared according to the design of each method: G1 Bramante Modified and G2 - CT. In G1, the teeth were embedded in resin blocks and sectioned at 2,0, 3,5 and 5,0 mm from the apex. The sections were photographed and the blocks were reassembled and subjected to rotary instrumentation. In G2, the teeth were embedded in an impression material and scanned with a microtomograph, before and after preparation. The images were reconstructed from the cross sections and the axial sections corresponding to distances of 2,0, 3,5 and 5,0 mm from the apex were selected. The results were submitted to statistical nonparametric test Mann-Whitney. In both groups, the canal transportation and IC for TF and ES systems were similar, with statistical difference only for the 3.5 mm section, while TF system caused less canal transportation than ES system, obtaining also better IC (p <0.05). When compared only the methods, regardless of instrument used, the canal transportation was significantly smaller (0.17 mm) in group 2 than in group 1 (0.27 mm) (p <0.05). At 3.5 and 5.0 mm, TF system promoted less transportation in group 2 than in group 1 (p <0.05). For ES system, statistical difference was found at 2.0 mm, where transportation was also lower in group 2 (p <0.05). It was concluded that the systems TF and ES behaved similarly about the canal transportation and the centering ability, allowing the preparation of curved canals with little deviation. The two instruments showed deviations for both the mesial and distal direction. When comparing only the methods of assessment, at CT the canal transportation was lower than in Bramante Modified method.

A instrumentação do canal radicular possui como conseqüência a formação de debris dentinários, os quais acumulam-se especialmente nas áreas mais complexas do sistema de canais radiculares. Por este motivo, atenção especial tem sido concedida aos métodos de agitação da substâ ncia química auxiliar, com o intuito de melhorar a sua eficácia química e mecânica. No entanto, não está claro se debris dentinários removidos do interior do canal radicular possuem efeito na qualidade da obturação. Portanto, os objetivos deste estudo foram, com o auxílio da microtomografia computadorizada (micro-CT): avaliar e quantificar a presença de debris dentinários em canais curvos, após o preparo químico-cirúrgico; comparar a remoção desses debris, após uso de Irrigação Ultrassônica Passiva (IUP) ou do sistema EndoVac; e avaliar a qualidade da obturação dos mesmos canais, mensurando o volume de material obturador e de espaços vazios. Vinte e quatro raízes mesiais de molares inferiores humanos extraídos foram divididos aleatoriamente em 2 grupos (n=12), de acordo com o método de irrigação final a ser avaliado. Cada espécime foi submetido a quatro escaneamentos: exame préoperatório, exame pós-preparo, exame pós-irrigação final e exame pós-obturação, com um microtomógrafo de raios-X SkyScan 1176, a uma resolução de 17,42 m. Após preparo químico-cirúrgico os grupos receberam irrigação final com IUP ou com o sistema EndoVac e em seguida obturados com a técnica termoplástica de ondas contínuas de condensação. Após a reconstrução das imagens resultantes dos quatro escaneamentos, o corregistro das mesmas foi realizado com o programa DataViewer. Os programas CTAn e CTvol foram utilizados para binarização dos objetos de interesse, análise volumétrica e reconstrução de modelos 3D do canal radicular, dos debris dentinários e do material obturador. Os dados foram analisados estatisticamente com o programa GraphPad Prism por meio do teste t de Student (p < 0,05). As análises de micro-CT revelaram debris dentinários acumulados no interior dos canais radiculares, ocupando uma porcentagem média em relação ao volume do canal de 2,71% para o grupo IUP e 4,10% para o grupo EndoVac. Não houve diferença entre os grupos quanto à remoção de debris dentinários, nem em relação ao volume de material obturador e de espaços vazios (p > 0,05). Concluiu-se que a IUP e o sistema EndoVac foram igualmente eficientes na remoção de debris dentinários, reduzindo em média 50% do seu volume. Também, a ativação dos irrigantes pelos dois métodos não interferiu na qualidade da obturação do canal radicular. / Root canal preparation has as a consequence the formation of hard-tissue debris, which accumulates specially in the complex areas of the root canal system. For this reason, special attention has been given to methods of agitation of the irrigants, aiming to improve its chemical and mechanical efficiency. However, it is not clear if dentin debris removed from the root canal have impact on the quality of root canal filling. Therefore, the objectives of this study were, with the aid of microcomputed tomography (micro-CT): evaluate and quantify the presence of hard-tissue debris in curved root canals, after chemical-surgical preparation; compare the removal of such debris after final irrigation with Passive Ultrasonic Irrigation (PUI) or with the EndoVac system; and evaluate the quality of filling of the same root canals, measuring the volume of filling material and voids. Twenty-four mesial roots of extracted mandibular human molars were randomly divided into 2 groups (n = 12) according to the method of final irrigation being evaluated. Each specimen was subjected to four scans: preoperative, post-operative, post-final irrigation and post-filling, with a microcomputed tomography SkyScan 1176, at a resolution of 17,42 m. After chemosurgical preparation groups received final irrigation with Passive Ultrasonic Irrigation (PUI) or with EndoVac system and were then filled with the continuous wave condensation thermoplastic technique. After the reconstruction of the images resulted from the four scans, co-registration was performed with the DataViewer software. CTAn and CTvol softwares were used for binarization of the objects of interest, volumetric analysis and reconstruction of 3D models of the root canal, hardtissue debris and the filling material. Data were statistically analyzed with the GraphPad Prism program through t students test (p < 0,05). The analysis of micro- CT showed hard-tissue debris accumulated inside the root canal, occupying an average percentage of 2.71 % for the PUI group and 4.10 % for EndoVac group. There was no difference between the groups regarding the removal of hard-tissue debris, or in relation to the volume of filling material and voids (p > 0.05). It was concluded that the EndoVac and PUI were equally efficient in the removal of hardtissue debris, reducing an average of 50% of its volume. Also, irrigants activation with the two methods did not affect the quality of root canal filling.

With the vast array of genetically altered (knockout) mice becoming available there is a need for quantitative, repeatable, and efficient methodologies to characterize the phenotypic consequences of knocking out specific genes. Since knockout animals often have the ability to compensate for a single missing gene, it is important to examine the structural, material and morphological properties to obtain a thorough understanding of the changes occurring. For this project, femurs of knockout mice were first scanned using microcomputed tomography (micro-CT) to obtain high-resolution images of the trabecular bone in the distal femur, as well as cortical bone in the mid-diaphysis. After scanning, the femurs were tested to destruction in four-point bending at the mid-diaphysis about the medial lateral axis of the femur. These methodologies allowed quantification of (1) morphologic properties such as bone volume fraction, trabecular properties and 2nd moment of the area (2) structural properties such as stiffness, maximum load at failure, and post yield deformation and (3) material properties such as bone mineral density, elastic modulus and yield strength. As part of two independent studies, two different knockout mice, cyclooxygenase-2 (COX-2 -/-) and Apolipoprotein E (APOE -/-), were examined for structure-function relationships using these methodologies. COX-2 knockout mice were found to have decreased mineral content in their femurs, and increased post yield deformation. APOE knockout mice at 10 weeks of age had decreased bone mass and structural properties. However, by 40 weeks of age APOE deficient mice caught up to and exceeded the structural properties and bone mass of their wild type counterparts.

Bone is a composite material consisting of hydroxyapatite crystals deposited in an oriented manner on a collagen backbone. The arrangement of the mineral and organic phases provides bone tissue with the appropriate strength, stiffness, and fracture resistance properties required to protect vital internal organs and maintain the shape of the body. A remarkable feature of bone is the ability to alter its properties and geometry in response to changes in the mechanical environment. However, in cases of metabolic bone diseases or aging, bone can no longer successfully adapt to its environment, increasing its fragility. To elucidate the mechanisms of bone microdamage, this research project developed a specimen-specific approach that integrated 3D imaging, histological damage labeling, image registration, and image-based finite element analysis to correlate microdamage events with microstructural stresses and strains under compressive loading conditions. By applying this novel method to different ages of bovine and human bone, we have shown that the local mechanical environment at microdamage initiation is altered with age. We have also shown that formation of microdamage is time-dependent and may have implications in age-related microdamage progression with cyclic and/or sustained static loading. The work presented in this dissertation is significant because it improved our understanding of trabecular bone microdamage initiation and unlocked exciting future research directions that may contribute to the development of therapies for fragility diseases such as osteoporosis.

Im Rahmen der vorliegenden Dissertationsschrift „Semi-quantitative röntgentomographische Untersuchungen zur Biodistribution von magnetischen Nanopartikeln in biologischem Gewebe“ wurden tomographische Untersuchungen an biologischen Objekten durchgeführt. Bei diesen Objekten handelt es sich um Gewebeproben nach minimal-invasiven Krebstherapien wie zum Beispiel magnetischem Drug Targeting und magnetischer Wärmebehandlung. Der Erfolg dieser Therapien ist sowohl abhängig von der korrekten Verteilung der magnetischen Nanopartikel als auch von der Tatsache, dass diese in der Zielregion in einer ausreichenden Menge vorhanden sind. Das Vorliegen dieser beiden Voraussetzungen ist in der vorliegenden Arbeit untersucht worden. Dabei lag der Schwerpunkt der Arbeit auf der Quantifizierung von magnetischem Material in unterschiedlichen biologischen Gewebeproben mittels Röntgenmikrocomputertomographie (XµCT). Für diesen Zweck wurde ein Kalibrationssystem mit speziellen Phantomen entwickelt, mit dessen Hilfe eine Nanopartikelkonzentration einem Grauwert voxelweise zugewiesen werden kann. Mit Hilfe der Kalibration kann der Nanopartikelgehalt sowohl in monochromatischen als auch in polychromatischen tomographischen Daten im Vergleich zu magnetorelaxometrischen Ergebnissen mit wenigen Prozent Abweichung ermittelt werden. Trotz Polychromasie und damit einhergehenden Artefakten können 3-dimensionale röntgentomographische Datensätze mit einer geringfügigen Konzentrationsabweichung im Vergleich zur quantitativen Messmethode Magnetorelaxometrie semi-quantitativ ausgewertet werden. / The success of the minimal invasive cancer therapies, called magnetic drug targeting and magnetic heating treatment, depends strongly on the correct distribution of the magnetic nanoparticles on one side. On the other side it depends on the fact that a sufficient amount of magnetic nanoparticles carrying drugs is accumulated in the target region. To study whether these two requirements are fulfilled motivates this PhD thesis „Semi-quantitative X-ray-tomography examinations of biodistribution of magnetic nanoparticles in biological tissues“. The analysis of the distribution of the magnetic nanoparticles in tumours and other tissue examples is realized by means of X-ray-micro computer tomography (XμCT). The work focuses on the quantification of the magnetic nanoparticles in different biological tissue samples by means of XµCT. A calibration of the tomographic devices with adequate phantoms, developed in the frame of this work, opens now the possibility to analyze tomographic data in a semi-quantitative manner. Thus, the nanoparticle concentration can be allocated voxel-wise to the grey values of the three-dimensional tomographic data. With the help of calibration of the tomography equipments used, polychromatic as well as monochromatic three-dimensional representations of objects can be analyzed with regard to the biodistribution of magnetic nanoparticles as well as with regard to their quantity. The semi-quantitative results have been compared with results obtained with a quantitative measurement method magnetorelaxometry (MRX). Thereby a good agreement of the semi-quantitative and quantitative data has been figured out.

[pt] As tecnologias digitais de fabricação por adição ou subtração têm em si um potencial ainda inexplorado pela indústria joalheira. Por isso, essa dissertação tem como objetivo avaliar as vantagens técnicas e comerciais que podem incentivar a transformação no seu uso pela indústria de joias, inclusive apontando exemplos de iniciativas internacionais e nacionais, estas últimas centradas no Estado do Rio de Janeiro, assinalando assim as razões de seus sucessos e falhas. Através de uma pesquisa bibliográfica se busca determinar as bases históricas e especificações técnicas dos principais processos de produção tradicionais (técnicas manuais tais como o repuxo, a cinzelagem, a modelagem e fundição por cera perdida, entre outras) e digitais (impressão 3D, escaneamento 3D e modelagem digital), para, nesse contexto, seguir-se à experimentação com as tecnologias mais novas, como forma de se buscar a comprovação da existência do potencial técnico e comercial destas tecnologias para o setor joalheiro fluminense que justifiquem essa inovação. / [en] The digital manufacturing technologies by addition or subtraction of material holds an unexplored potential for the jewellery industry. Therefore, this dissertation aims to assess the technical and commercial advantages that can encourage the transformation of its use by the jewellery industry, pointing out examples of international and national enterprises, the latest centered in the Brazilian State of Rio de Janeiro, thus signalizing the reasons of their successes and failures. Through a literature research this work pursuits the historical foundations and the technical specifications of the traditional manual techniques (such as repoussé, chasing, lost wax casting, among others) and digital manufacturing processes (3D printing, 3D scanning and 3D modelling), for, in this context, experimenting with the newest technologies, as a way to seek evidence of its technical and commercial potential for the jewellery industry in Rio de Janeiro that justifies the innovation.