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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.
1

Biomateriais de quitosana/gelatina com resina de jatobá: influência do grau de acetilação da quitosana e da inclusão da resina / Chitosan-gelatin biomaterials with jatoba resin: influence of the degree of acetylation of chitosan and inclusion of resin

Murilo Álison Vigilato Rodrigues 20 February 2017 (has links)
O grau de acetilação (GA) da quitosana é um parâmetro que influi nas interações inter e intramoleculares deste polímero e, portanto, em suas propriedades. É comum a incorporação de compostos a filmes de quitosana para melhora de suas propriedades, contudo, não há relatos da incorporação da resina de jatobá, composto natural com potencial atividade biológica, a estes filmes. Portanto, esta pesquisa buscou estudar a influência do grau de acetilação da quitosana e da inclusão da resina de jatobá sobre as propriedades de filmes de quitosana/gelatina, visando uma possível aplicação em cicatrização de feridas cutâneas. Foram produzidas amostras de quitosana a partir de gládios de lula com três diferentes valores de GA, variáveis de 7 a 35%. As soluções formadoras de filme apresentaram redução no valor de concentração inibitória mínima contra Staphylococcus aureus tanto com a redução no GA quanto com a incorporação da resina de jatobá, apesar da resina isoladamente não ter apresentado atividade antimicrobiana nas concentrações estudadas. Os ensaios reológicos demonstraram que a inclusão da resina de jatobá e maiores valores de GA reduziram os valores de viscosidade das soluções, enquanto a temperatura de gelificação também diminuiu com a inclusão da resina de jatobá. Os filmes apresentaram uma superfície lisa e compacta para as blendas quitosana/gelatina e uma morfologia rugosa e irregular após adição da resina de jatobá, quando analisados por MEV. A adição de resina de jatobá levou também a redução na estabilidade térmica dos filmes. Nos testes de absorção em PBS ficou evidente o efeito do GA da quitosana sobre a propriedade, exibindo valores de intumescimento consideravelmente maiores para os filmes conforme o aumento no GA, fator relacionado ao aumento do número de grupos acetila. Por outro lado, a adição de resina de jatobá e o processo de neutralização reduziram consideravelmente o grau de intumescimento dos filmes. Foi observado também que a redução no GA e a inclusão da resina de jatobá tanto aumentaram a permeação ao vapor de água dos filmes, quanto levaram a uma redução da solubilidade destes materiais. / The degree of acetylation (DA) of chitosan is a parameter that influences the inter and intramolecular interactions of this polymer and, therefore, its properties. In addition, it is common the incorporation of other compounds to chitosan films to improve their properties. However, there are no reports of the incorporation of jatoba resin, a natural compound with potential biological activity. Therefore, this research aimed to study the influence of the degree of chitosan acetylation and the inclusion of the jatoba resin on the properties of chitosan/gelatin films, with potential applications in wound healing. Samples of chitosan were produced from squid pens with three different DA values, ranging from 7 to 35%. The reduction in DA of chitosan and incorporation of the jatoba resin into the film-forming solutions resulted in reductions in the minimum inhibitory concentration against Staphylococcus aureus, although the isolated resin did not exhibit antimicrobial activity at the concentrations studied. The rheological tests showed that the inclusion of the jatoba resin and higher DA values reduced the viscosity of the solutions, while gelation temperature values decreased with the jatoba resin addition. The films presented a smooth and compact surface for the chitosan/gelatin blends and a rough and irregular morphology after addition of the jatoba resin. The addition of jatoba resin also led to the reduction in thermal stability of the films. The effect of the DA of chitosan on the absorption of PBS was evident, exhibiting considerably higher swelling values for the films as a function of the DA increase, a factor related to the increase in the number of acetyl groups. Moreover, the addition of jatoba resin and neutralization process considerably reduced the degree of swelling of the films. The water vapor permeability of the films increased due to both the reduction in DA and the inclusion of the jatoba resin, whereas these changes led to the reduction of the solubility of these materials.
2

Biomateriais de quitosana/gelatina com resina de jatobá: influência do grau de acetilação da quitosana e da inclusão da resina / Chitosan-gelatin biomaterials with jatoba resin: influence of the degree of acetylation of chitosan and inclusion of resin

Rodrigues, Murilo Álison Vigilato 20 February 2017 (has links)
O grau de acetilação (GA) da quitosana é um parâmetro que influi nas interações inter e intramoleculares deste polímero e, portanto, em suas propriedades. É comum a incorporação de compostos a filmes de quitosana para melhora de suas propriedades, contudo, não há relatos da incorporação da resina de jatobá, composto natural com potencial atividade biológica, a estes filmes. Portanto, esta pesquisa buscou estudar a influência do grau de acetilação da quitosana e da inclusão da resina de jatobá sobre as propriedades de filmes de quitosana/gelatina, visando uma possível aplicação em cicatrização de feridas cutâneas. Foram produzidas amostras de quitosana a partir de gládios de lula com três diferentes valores de GA, variáveis de 7 a 35%. As soluções formadoras de filme apresentaram redução no valor de concentração inibitória mínima contra Staphylococcus aureus tanto com a redução no GA quanto com a incorporação da resina de jatobá, apesar da resina isoladamente não ter apresentado atividade antimicrobiana nas concentrações estudadas. Os ensaios reológicos demonstraram que a inclusão da resina de jatobá e maiores valores de GA reduziram os valores de viscosidade das soluções, enquanto a temperatura de gelificação também diminuiu com a inclusão da resina de jatobá. Os filmes apresentaram uma superfície lisa e compacta para as blendas quitosana/gelatina e uma morfologia rugosa e irregular após adição da resina de jatobá, quando analisados por MEV. A adição de resina de jatobá levou também a redução na estabilidade térmica dos filmes. Nos testes de absorção em PBS ficou evidente o efeito do GA da quitosana sobre a propriedade, exibindo valores de intumescimento consideravelmente maiores para os filmes conforme o aumento no GA, fator relacionado ao aumento do número de grupos acetila. Por outro lado, a adição de resina de jatobá e o processo de neutralização reduziram consideravelmente o grau de intumescimento dos filmes. Foi observado também que a redução no GA e a inclusão da resina de jatobá tanto aumentaram a permeação ao vapor de água dos filmes, quanto levaram a uma redução da solubilidade destes materiais. / The degree of acetylation (DA) of chitosan is a parameter that influences the inter and intramolecular interactions of this polymer and, therefore, its properties. In addition, it is common the incorporation of other compounds to chitosan films to improve their properties. However, there are no reports of the incorporation of jatoba resin, a natural compound with potential biological activity. Therefore, this research aimed to study the influence of the degree of chitosan acetylation and the inclusion of the jatoba resin on the properties of chitosan/gelatin films, with potential applications in wound healing. Samples of chitosan were produced from squid pens with three different DA values, ranging from 7 to 35%. The reduction in DA of chitosan and incorporation of the jatoba resin into the film-forming solutions resulted in reductions in the minimum inhibitory concentration against Staphylococcus aureus, although the isolated resin did not exhibit antimicrobial activity at the concentrations studied. The rheological tests showed that the inclusion of the jatoba resin and higher DA values reduced the viscosity of the solutions, while gelation temperature values decreased with the jatoba resin addition. The films presented a smooth and compact surface for the chitosan/gelatin blends and a rough and irregular morphology after addition of the jatoba resin. The addition of jatoba resin also led to the reduction in thermal stability of the films. The effect of the DA of chitosan on the absorption of PBS was evident, exhibiting considerably higher swelling values for the films as a function of the DA increase, a factor related to the increase in the number of acetyl groups. Moreover, the addition of jatoba resin and neutralization process considerably reduced the degree of swelling of the films. The water vapor permeability of the films increased due to both the reduction in DA and the inclusion of the jatoba resin, whereas these changes led to the reduction of the solubility of these materials.
3

Avaliação Histomorfométrica do efeito de um Bioativo Amazônico sobre a Camada Híbrida da Dentina

Meira, Joyce de Figueiredo 23 May 2014 (has links)
Submitted by Maryse Santos (maryseeu4@gmail.com) on 2016-09-02T13:57:40Z No. of bitstreams: 1 Dissertação de Mestrado- Joyce de Figueiredo Meire.pdf: 2807877 bytes, checksum: cbe238bdb338faf2eb0cffa862aeec1e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-09-16T13:11:08Z (GMT) No. of bitstreams: 1 Dissertação de Mestrado- Joyce de Figueiredo Meire.pdf: 2807877 bytes, checksum: cbe238bdb338faf2eb0cffa862aeec1e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-09-16T13:18:09Z (GMT) No. of bitstreams: 1 Dissertação de Mestrado- Joyce de Figueiredo Meire.pdf: 2807877 bytes, checksum: cbe238bdb338faf2eb0cffa862aeec1e (MD5) / Made available in DSpace on 2016-09-16T13:18:09Z (GMT). No. of bitstreams: 1 Dissertação de Mestrado- Joyce de Figueiredo Meire.pdf: 2807877 bytes, checksum: cbe238bdb338faf2eb0cffa862aeec1e (MD5) Previous issue date: 2014-05-23 / Não informada / The adhesion of polymeric materials to dentin is still considered a big challenge because it is a complex histological substrate, predominantly tubular and intrinsically moist. Sclerosis and pathological processes such as caries, as well as the dentin demineralization, result in dentin properties changes. Among these transformations there is the activation of matrix metalloproteinases (MMPs) in the dentin matrix after etching. The solvents and monomers effects on the demineralized dentin have an important role in the whole concept of bonding. The use of disinfectant solutions has become an alternative to reduce these effects. Despite the great efficacy, the 2% chlorhexidine (CHX) can bring side effects. Thus, this research aims to morphometrically analyze the effect of copaiba oil emulsion 10% (COE) on the collagen of sound and carious dentin. In the analysis of the exposure of collagen fibers 80 specimens were fabricated. In the collagen fibers exposure analysis 80 specimens were fabricated from sound third molars that were immersed in test solutions for 3 months aging: G1- sound dentin (SD) + water, G2 - carious dentin (CD) + water, G3 - SD + 2% CHX, G4 - CD + CHX, G5 – SD + COE with preservative A (COE+PA), G6 - CD+COE+PA, G7 - SD + COE with preservative B (COE+PB), G8 - CD + COE+PB, G9 - SD + COE with preservative (COE+PC), G10 - CD + COE+PC. The specimens were histologically prepared, stained with Goldner's trichrome and analyzed. To analyze the examiner’s reproducibility the Pearson correlation test was used. To the data of thickness collagen layer was applied the non-parametric Kruskal-Wallis test (p <0.05). Increased frequency of exposed collagen was observed in G10 (CD+ COE+PC), followed by groups G6 (CD+COE+PA) and G5 (SD+COE+PA). The data showed no statistical difference between the groups G7 and G9, which had the thickest hybridized collagen, no difference when compared to G1 and G2, which showed less thickness. The G3, G4 and G8 groups showed no statistically significant difference between themselves and the other above. Qualitative analysis of histological samples for the study was taken by three pathologists simultaneously. Specimens treated with COE had the thickest exposed and hybridized collagen than the groups treated with CHX and water. Regarding the CD, the CHX group treated showed higher proportion of specimens with hybridized collagen. G7 showed 100% of specimens with hybridized collagen and better homogeneity of the hybrid layer. / A adesão de materiais poliméricos à dentina ainda é considerada um grande desafio por ser este um substrato histologicamente complexo, predominantemente tubular e intrinsecamente úmido. Processos patológicos como esclerose e cárie, assim como a desmineralização da dentina, resultam em alterações nas propriedades do substrato dentinário. Dentre essas transformações está a ativação de metaloproteinases (MMPs) presentes na matriz dentinária após condicionamento ácido. . O uso de agentes de limpeza cavitária tornou-se uma alternativa para reduzir esses efeitos. Apesar da grande eficácia, a clorexidina 2% (CLX) pode trazer efeitos colaterais, como o manchamento dentário. Assim, essa pesquisa se propõe a analisar morfometricamente o efeito das emulsões a base de óleo de copaíba a 10% sobre a formação da camada híbrida.Na análise da exposição de fibras colágenas foram confeccionados 80 espécimes a partir de 3o terceiros molares hígidos que foram imersos em soluções testes durante 3 meses de envelhecimento: G1 - dentina hígida (DH) + água, G2 -dentina cariada (DC) + água, G3 - DH+CLX, G4-DC+CLX, G5-DH+CM+conservante A (CM+A), G6-DC+CM+A, G7-DH+CM + conservante B (CM+B), G8-DC+CM+B, G9-DH+CM+conservante C (CM+C), G10-DC+CM+C. Os espécimes foram preparados histologicamente, corados em Tricrômico de Goldner e analisados, onde foram feitas imagens, utilizando um aumento de 400x, com a câmera Dino-Eye. A espessura de colágeno exposto e hibridizado foi medida através do programa UTHSCSA Image Tool.. A reprodutibilidade do examinador foi pelo teste de correlação de Pearson. Aos dados de espessura da camada de colágeno foi aplicado o teste não-paramétrico de Kruskal-Wallis (p<0,05). Maior frequência de colágeno exposto foi observada em G10 (DC + CM+C), seguidos dos grupos G6 (DC + CM+A) e G5 (DH + CM+A). Os dados demonstraram que não houve diferença estatística entre os grupos G7 e G9, que apresentaram maior espessura de colágeno hibridizado, havendo diferença quando comparados aos grupos G1 e G2, que apresentaram menor espessura. Os grupos G3, G4 e G8 não apresentaram diferença estatística significante entre si e entre os demais supracitados. A análise histológica foi feita de maneira qualitativa por três patologistas, simultaneamente. Os espécimes tratados com as emulsões à base de copaíba apresentaram maior espessura de colágeno exposto e hibridizado que os grupos tratados com clorexidina e água. Quanto o à dentina cariada o grupo tratado com clorexidina apresentou maior proporção de corpos de prova com colágeno hibridizado. G7 apresentou 100% de espécimes com colágeno hibridizado e melhor homogeneidade de camada híbrida.
4

Analyse chimique des matières résineuses employées dans le domaine artistique pré-hispanique au Mexique : application aux échantillons archéologiques aztèque et maya / Chemical analysis of resinous materials employed in artistic pre-hispanic Mexico : application to aztec and maya archaeological samples

Lucero, Paola 14 September 2012 (has links)
Dans le present travail de recherche notre équipe s'est interessé à l'étude de la composition chimique -au niveau moléculaire- d'un groupe d'échantillons résineuses provenant d'objects Aztecs et Mayas. Le but ultime de cette étude a été d'établir l'origin botanique de ces résines et d'avoir une vue d'ensemble des formulations utilisées dans les adhésifs ou les figurines, afin de mieux comprendre leurs propriétes physiques.Pour aboutir à cet objectif une stratégie analytique très spécifique a été créeé et mise en oeuvre. Cette stratégie a inclus l'analyse d'échantillons des résines archéologiques mais aussi de résines d'origine botanique certifiée et de résines commerciales, achetées dans des marchés traditionels au Mexique dans une région qui correspond a la one géographique occupée autre fois par l'empire aztèque.L'étude des matériaux a fait appel à des techniques tels que l'observation a l'échelle microscopique, la spectroscopie infrarouge (IRTF), la chromatographie liquide-DAD (HPLC-UV/Vis) et la chromatographie en phase gazeuse couplée à la spéctroscopie de masse (CPG-SM).L'étude moléculaire de ces échantillons, et plus précisement, l'étude leur fraction tritérpenique a permis de : Établir un profil moléculaire des résines pour chaque origine botanique étudiée Idéntifier précisement certain composées tritérpeniques présents dans toutes les échantillons Réperer les molécules tritérpeniques susceptibles d'être utilisées dans l'avenir comme des marqueurs moléculaires d'origine botanique pour les résines frais des espèces étudiées Suggèrer une origine botanique pour les échantillons archéologiques Aztèques Écarter des origines botaniques possibles pour l'échantillon Maya Avoir une vue d'ensemble de l'origine botanique des résines commercialisées au territoire mexicain sous le nom de «copal» Créer un protocole d'analyse simple pour permettre aux professionnels de la conservation et des biomatériaux d'établir l'origine botanique et un profil moléculaire des résines utilisées dans des expériences diverses Caractériser le comportement du copal lors du vieillisement naturel et artificiel Établir des molécules susceptibles de devenir marqueurs moléculairs pour les deux types de vieillisement Établir que l'origine botanique d'un échantillon résineux peut être retrouvée malgré son âge (archéologique) / In the present work, the molecular composition of series of resinous aztec and maya archaeological samples were investigated to determinate their nature.Thus an analytical strategy was specifically designed. This analytical strategy included the analysis of botanically certified resins, freshly collected. It included as well the analysis of commercial samples bought in Mexican traditional markets.The study of all the samples included microscopical techniques, Fourier Inverse Infrared Spectrometry (FTIR) , High Performance Liquid Chromatography coupled to Ultraviolet-visible spectrometry (HPLC-UV/Vis) and Gas Chromatography coupled to Mass Spectrometry (GC-MS).The molecular study of these samples, in particular of their trterpenic composition allowed to : establish the molecular profile of resins from certified botanical origin. Identifiy some of the triterpenic compounds present in samples; Identify triterpenic molecules that could be uses as molecular markers for each botanical origin. Find the botanical origin of archeological astec samples. Discard possible botanic origins for maya archaeological sample. Have an overview of the origin of commercial samples of mexican copal. Create a simple protocol that allows conservation and biomaterials professionals to establish the botanical origin of archaeological and commercial resins, used in conservation interventions. Observe the behavior of copal materials upon ageing, establishing potential markers for natural ageing in copal, under darkness. Asses the botanical origin of a sample can be found regardless the age of the resin
5

Kořeny moravské urbanistické struktury / Roots of Moravian Urban Structure

Mohelník, Ladislav Unknown Date (has links)
The thesis has been written on the basis of main architectural concepts and their application in real life within a historical context investigation. Main architectural concepts are represented in a harmony of architectural composition that deals with relations among form, structure and space in the unique art work. Genius loci play very important role in the architectural creation - it represents a special and extra-ordinary urban locality and its architectural value in the historical, geographical and cultural context. The origin of Ostravice village within the historical frame concept of Moravia domain is the topic of this thesis. Other historical documents gave information about Bruneswerde as the Brno Castle. That means Brno Castle had to be founded not in Brno (as it has been consid-ered for many years) but it was located in Beskydy at Ostravice. The sacred city – Civitas Dei had been located in Bruneswerde region in early ages as the centre of European culture, education and spiritual life. Civitas Dei – divine Jerusalem in the transcription of St. Augustine's book De civitate Dei – is not only glorification of God and religious fantasy. It is also one of significant clues for recognition of historical architecture. The depiction of unknown settlement from the book of unde-fined origin is a superb testimony about extinct architectural works. They are legible from cadastral maps. Brno Castle - residence of nobility and power served shelter to St. Vojtěch, St. Prokop, St. Václav and St. Ludmila as it is obvious for the mentioned picture. Three major temples, three com-position axes symbolized by three towers on coins are in analogical relation to Brno triangle of four saints - the Saint family of Brno temples. Powerful ambitions of Brno City principals and clergy are inscribed into the urban structure in the way of composition relations which are legible to them who devoted themselves to the mystery of harmony. The absence of historical continuity affects personal attitudes and also identity of the whole community. The architecture truly reflects the past state of polis and it is eloquent even after its death. The architectural composition relations influence the natural environment for long time, longer than the architectural work existence. The geometric order of Renaissance Brno existence has not been in attention of architects so far. The features were discovered in characteristic paintings by Albrecht Durer. They are evidently secret works of the genius. A meaningful collaborator and follower in the extensive project was also his friend Jan Čert from Brno and lately from Vienna. His noble genealogy played a significant role in history of Silesia and Moravia for centuries. It is tendency to consider him as Austrian or even German architect. It is because of the fact that the genealogy tree of his noble family had roots in Moravia. It is supposed that Durer with Jan Čert´s support created the extraordinarily monumental architectural and urban works in Brno. A remarkable consensus in the urban composition of two squares and transition of traditional urban structure of Ostravice Civitas Dei into the modern Brno is also confirmed due to the identification of noble creators and owners, who were at the foundation, transformation and extinction of elements of the Moravian urban structure.

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