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京都大学 / 新制・論文博士 / 博士(医学) / 乙第13481号 / 論医博第2256号 / 新制||医||1059(附属図書館) / (主査)教授 平井 豊博, 教授 岩田 想, 教授 秋山 芳展 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

INTRODUCTION: Pubertal growth is an important time during development for bone accrual and attainment of peak bone mass. Suboptimal bone gain has been observed in females with reproductive abnormalities such as primary and secondary amenorrhea and these conditions are very prevalent in female athletes. Amenorrhea is associated with decreased estradiol levels. Previous research has shown that in prepubertal animals a low estrogen environment significantly decreased mechanical strength, but there was no significant loss in bone area and actually an increase in moment of inertia. The decrease in mechanical properties may be related to the microstructure of the bone. Two types of bone are involved in growth-- woven bone, which is added for structural support in the short term, and lamellar bone , which is highly organized and has a greater contribution to overall strength. We will test the hypotheses that suppressed estradiol will result in bones with no change in cortical area and decreased strength properties but will have a larger composition of non lamellar bone as opposed to lamellar bone. PURPOSE: The goal of this study was to determine the relative amounts of woven and lamellar tissue in a bone and the relationship with the bone's mechanical strength in two models of low estrogen-- pre- and post-pubertal onset. METHODS: Fifty-Five female Sprague-Dawley rats were randomly assigned into four groups: a control group (n=14) and three experimental groups injected with gonadotropin releasing-hormone antagonist (GnRH-a)-- the Dose 1 group was injected with 1.25 mg/kg/dose daily (n=14), the Dose 2 was injected with 2.5 mg/kg/dose daily (n=14), and the Dose 3 group was injected with 5.0 mg/kg/dose, 5 days per week (n=13). All groups were sacrificed at Day 49. Additionally, twenty-nine Sprague Dawley rats were randomly assigned into three groups. The baseline day 65 group (BL 65) was sacrificed on day 65 (n=9). There was an aged match control group that was sacrificed on day 90 (n=12). Finally, there was an AMEN experiment group injected with 2.5 mg/kg/dose daily that was sacrificed on day 90 (n=9). All experimental groups for both protocols received injections of gonadotropin releasing hormone antagonists (GnRH-a) (Zentaris GmbH) intraperitoneally. Left femora were mechanically tested under 3-point bending. The right femora were dehydrated, embedded in polymethylmethacrylate, cut and ground to 100 µm thickness. Bones were analyzed under polarized light using Stereo Investigator Software (MBF Bioscience, VT). The proportion of the cortex with primary lamellar vs. non-lamellar/other primary tissue type was measured and expressed as percent of the total cortical bone area. Outcome measures included lamellar endocortical area, lamellar periosteal area, cortical area, endocortical area, % lamellar area and % non-lamellar area. RESULTS: There was a significant decrease (p<.05) in the distribution of lamellar versus non-lamellar cortical tissue type in the experimental group in the model of delayed puberty. Additionally, the pre-pubertal bones had a lower percentage of lamellar periosteal and endocortical area. The post-pubertal group showed no significant differences between the control and experimental group in any of the outcome measures. CONCLUSION: There were significant differences in relative bone distribution throughout the femoral cortex. Relative decreases in lamellar tissue distribution, especially on the periosteal surface, will result in decreased mechanical strength due to increased percentage of woven bone in pre-pubertal models. / Kinesiology / Accompanied by one .pdf file: Lamellar/Woven Database.

[pt] O aparecimento de emulsões tem gerado vastos desafios operacionais e econômicos para a indústria petrolífera, principalmente na etapa de separação de óleo e água no processamento primário do fluido produzido de petróleo. Vários estudos anteriores sugerem que os asfaltenos são responsáveis pela formação e estabilidade de emulsões de petróleo. No entanto, com a descoberta do Pré-Sal, a formação de emulsões estáveis tem sido observada mesmo a partir de óleos brutos com baixo teor de asfaltenos, sugerindo que outras frações do óleo bruto tenham um papel importante nestas emulsões. O levantamento bibliográfico deste trabalho mostrou diferentes aplicações em que as ceras de parafina podem atuar como partículas Pickering ou redes em gel que estabilizam emulsões em outras áreas. Assim, surge a hipótese de que elas também tenham um papel relevante na estabilização de emulsões de petróleo. O objetivo deste estudo foi avaliar a capacidade de formação e estabilização de emulsões água-em-óleo (A/O) por ceras de parafinas de petróleo e sua possível interação com outras frações com atividade interfacial. Para isso, a primeira parte do trabalho envolveu a extração de ceras de parafina de óleos brutos brasileiros e a análise da sua composição química e de seus respectivos óleos brutos. A segunda parte consistiu na caracterização de emulsões formadas por óleos brutos, óleos residuais da extração de asfaltenos ou óleos residuais da extração de ceras de parafinas. Por fim, a terceira parte envolveu o preparo de emulsões modelos considerando a solubilidade dos componentes dos óleos para identificar as frações do petróleo que formam e estabilizam as emulsões. Os resultados indicaram que a remoção de asfaltenos aumentou a estabilidade da emulsão e, em outro resultado, a remoção das ceras diminuiu drasticamente a estabilidade da emulsão a estabilidade das emulsões em questão. Por outro lado, apenas as ceras de parafina não são suficientes para promover a formação da emulsão, sendo necessária sua combinação com outros componentes anfifílicos diferentes dos asfaltenos. A análise de espalhamento de raios X de baixo ângulo (SAXS) revelou que as ceras só formaram estrutura lamelar quando altamente purificadas, o que é muito distante da mistura complexa que é o óleo bruto. Portanto, as ceras de parafina provavelmente não formam uma rede em gel para estabilizar as emulsões, mas formam partículas cristalinas que promovem estabilização Pickering. Em conclusão, as emulsões modelos tiveram uma boa correlação com os resultados de amostras reais graças à escolha de componentes e solventes para simular emulsões de petróleo bruto. Esta correlação indicou que outros componentes do petróleo além do asfaltenos e ceras desempenham um papel crucial na formação de emulsões, enquanto a cera de parafina proporciona estabilização por mecanismo de Pickering. Portanto, este estudo aumenta a compreensão dos mecanismos que governam as emulsões de óleos brutos brasileiros parafínicos. / [en] The appearance of emulsions has generated vast operational and economic challenges for the oil industry, mainly in separating the oil, and water fractions in the separator vessel of the produced fluid. Several previous studies suggest that asphaltenes are responsible for forming and stabilizing petroleum emulsions. However, with the discovery of the Pre-Salt, the formation of stable emulsions has been observed even from crude oils with a low asphaltene content, suggesting that other fractions of the crude oil play an important role in these emulsions. The literature review of this work showed different applications in which paraffin waxes can act as Pickering particles or gel networks that stabilize emulsions. Thus, the hypothesis arises that they also have a relevant role in the stabilization of petroleum emulsions. This study aimed to evaluate the capacity for the formation and stabilization of water-in-oil (W/O) emulsions by petroleum paraffin waxes and their possible interaction with other fractions with interfacial activity. To achieve this, the first part of the work involved the extraction of paraffin waxes from Brazilian crude oils and the analysis of their chemical composition and their respective crude oils. The second part consisted of the characterization of emulsions formed by crude oils, residual oils from the extraction of asphaltenes, or residual oils from the extraction of paraffin waxes. Finally, the third part involved the preparation of model emulsions considering the solubility of the oil components to identify the petroleum fractions that form and stabilize the emulsions. The results indicated that the removal of asphaltenes increased the stability of the emulsion, while the removal of waxes drastically decreased it. On the other hand, paraffin waxes alone are not sufficient to promote the formation of the emulsion, requiring their combination with other amphiphilic components other than asphaltenes. Small-angle X-ray scattering (SAXS) analysis revealed that the waxes only formed a lamellar structure when highly purified, which is very far from the complex mixture that is crude oil. Therefore, paraffin waxes probably do not form a gel network to stabilize emulsions, but rather form crystalline particles that promote Pickering stabilization. In conclusion, the model emulsions correlated well with the results from real samples thanks to the choice of components and solvents to simulate crude oil emulsions. This correlation indicated that polar petroleum fractions other than asphaltenes play a crucial role in the formation of emulsions, while paraffin wax provides stabilization by the Pickering mechanism. Therefore, this study increases understanding of the mechanisms that govern paraffinic Brazilian crude oil emulsions.

[ES] La presente tesis doctoral se centró en el desarrollo y modificación de materiales microestructurados basados en sulfuros metálicos para la producción de combustibles solares. Se obtuvieron y caracterizaron dos nuevos materiales laminares basados en sulfuro de estaño y zinc, IZM-5 e ITQ-75. Dado que se pretende utilizar dichos materiales en procesos basados en el uso de energía solar, fue necesario ajustar su estructura electrónica mediante una estrategia de dopaje y su accesibilidad mediante la modificación de la composición del gel de síntesis o mediante métodos posteriores a la síntesis. Se probaron diferentes agentes dopantes como cobre, cobalto, níquel y hierro, así como la inserción de un complejo de rutenio. Los más exitosos fueron el cobre y el cobalto, ya que con su presencia es posible reducir el valor de la band gap a 2,0 eV, un valor dentro del rango óptimo para procesos de producción de combustibles solares. Cuando estos agentes dopantes estuvieron presentes en el gel de síntesis de IZM-5, se descubrió que no se obtenía el patrón de difracción esperado, sino uno de un nuevo material, denominado ITQ-76. Al igual que con las zeolitas, los primeros intentos para permitir el acceso a los centros fotoactivos consistieron en liberar la microporosidad, la superficie interna, mediante la eliminación del agente orgánico director de estructura utilizado durante el proceso de síntesis. Se intentó alternativamente mejorar la superficie externa (tamaño de partícula o mesoporosidad). De las diferentes estrategias probadas, se descubrió que variar la composición del gel de síntesis fue la más exitosa. Se probaron la inserción de sacáridos, previamente estudiados en la literatura como agentes inductores de mesoporosidad, y el aumento de la viscosidad del gel de síntesis para disminuir el tamaño de cristal final. Sin embargo, la presencia de sacáridos no condujo a la formación de un sistema mesoporoso; la mejora en la accesibilidad se debió a la disminución del tamaño de partícula. Al aumentar la viscosidad del gel, también fue posible disminuir el tamaño promedio de los cristales y, en consecuencia, aumentar la superficie externa. Después de la modificación de las estructuras estudiadas con el fin de obtener una amplia gama de propiedades, se evaluó su rendimiento fotocatalítico mediante la reacción de ruptura de la molécula de agua. Parecía existir una relación tipo "volcano" entre el rendimiento fotocatalítico y la superficie externa. Según la literatura revisada, este comportamiento podría explicarse por el equilibrio entre el aumento de los centros activos disponibles y el aumento de los defectos en la superficie, los cuales son centros potenciales de recombinación. En cuanto a la relación entre el rendimiento fotocatalítico y el valor de la band gap, nuevamente parece existir una relación tipo "volcano". Según la bibliografía revisada, se encontró que con la reducción del valor de la band gap aumenta el número de fotones absorbidos y, como tal, se espera que aumente el rendimiento. Sin embargo, es necesario que las cargas fotogeneradas tengan un potencial suficiente para participar en la reacción deseada. Como resultado, por debajo de cierto valor de band gap, las cargas fotogeneradas ya no tienen un potencial suficiente y, por ello, el rendimiento disminuye. De las diferentes muestras probadas, las modificadas con sacarosa destacaron por tener el mejor rendimiento. Hasta ahora no ha sido posible desentrañar el fenómeno detrás de esta mayor reactividad. Por lo tanto, se requiere una caracterización más detallada de estas muestras para comprender cómo la presencia del componente orgánico influye en la estructura electrónica del material y, en consecuencia, en su rendimiento. También sería importante evaluar la estabilidad del componente orgánico durante la reacción, específicamente para verificar que no sufra un proceso de oxidación que pueda producir protones, que luego sean capaces de formar hidrógeno. / [CA] La present tesi doctoral es va centrar en el desenvolupament i modificació de materials microestructurats basats en sulfurs metàl·lics per a la producció de combustibles solars. Es van obtenir i caracteritzar dos nous materials lamel·lars basats en sulfur d'estany i zinc, IZM-5 i ITQ-75. Com que es pretén utilitzar aquests materials en processos basats en l'ús d'energia solar, va ser necessari ajustar la seua estructura electrònica mitjançant una estratègia de dopatge i la seua accessibilitat mitjançant la modificació de la composició del gel de síntesi o mitjançant mètodes posteriors a la síntesi. Es van provar diferents agents dopants com coure, cobalt, níquel i ferro, així com la inserció d'un complex de ruteni. Els més reeixits van ser el coure i el cobalt, ja que amb la seua presència és possible reduir el valor de la band gap a 2,0 eV, un valor dins de l'abast òptim per a processos de producció de combustibles solars. Quan aquests agents dopants van estar presents en el gel de síntesi d'IZM-5, es va descobrir que no s'obtenia el patró de difracció esperat, sinó un de nou material, anomenat ITQ-76. Al igual que amb les zeolites, els primers intents per a permetre l'accés als centres fotoactius van consistir en alliberar la microporositat, la superfície interna, mitjançant l'eliminació de l'agent orgànic director d'estructura utilitzat durant el procés de síntesi. Es va intentar alternativament millorar la superfície externa (mida de partícula o mesoporositat). De les diferents estratègies provades, es va descobrir que variar la composició del gel de síntesi va ser la més reeixida. Es van provar la inserció de sacàrids, prèviament estudiats en la literatura com a agents inductors de mesoporositat, i l'augment de la viscositat del gel de síntesi per a disminuir la dimensió del cristall final. No obstant això, la presència de sacàrids no va conduir a la formació d'un sistema mesoporós; la millora en l'accessibilitat va ser a causa de la disminució de la mida de partícula. Augmentant la viscositat del gel, també es va poder disminuir la mida mitjana dels cristalls i, en conseqüència, augmentar la superfície externa. Després de la modificació de les estructures estudiades amb l'objectiu d'obtenir una àmplia gamma de propietats, es va avaluar el seu rendiment fotocatalític mitjançant la reacció de ruptura de la molècula d'aigua. Hi semblava haver una relació tipus "volcà" entre el rendiment fotocatalític i la superfície externa. Segons la literatura revisada, aquest comportament podria explicar-se per l'equilibri entre l'augment dels centres actius disponibles i l'augment de les defectes en la superfície, els quals són centres potencials de recombinació. Pel que fa a la relació entre el rendiment fotocatalític i el valor de la band gap, de nou sembla existir una relació tipus "volcà". Segons la bibliografia revisada, es va trobar que amb la reducció del valor de band gap augmenta el nombre de fotons absorbits i, com a tal, s'espera que augmenti el rendiment. No obstant això, és necessari que les càrregues fotogenerades tinguin un potencial suficient per a participar en la reacció desitjada. Com a resultat, per sota d'un cert valor de band gap, les càrregues fotogenerades ja no tenen un potencial suficient i, per tant, el rendiment disminueix. De les diferents mostres provades, les modificades amb sacarosa van destacar per tenir el millor rendiment. Fins ara no ha estat possible desxifrar el fenomen darrere d'aquesta major reactivitat. Per tant, es requereix una caracterització més detallada d'aquestes mostres per a comprendre com la presència del component orgànic influeix en l'estructura electrònica del material i, en conseqüència, en el seu rendiment. També seria important avaluar l'estabilitat del component orgànic durant la reacció, específicament per a verificar que no patisca un procés d'oxidació que puga produir protons, que després siguen capaços de formar hidrogen. / [EN] The present doctoral thesis focused on the development and modification of metal sulfide based microstructured materials for the solar fuels production. Two new materials, IZM-5 and ITQ-75 made of tin and zinc sulfide, were obtained and characterized. Since it is intended to use such materials on solar-driven processes, it was necessary to fine tune their electronic structure, through a doping strategy, and their accessibility, through the modification of the synthesis gel composition or by post synthesis methods. Different doping agents, such as copper, cobalt, nickel and iron, as well as the insertion of a ruthenium complex were tested. The most successful ones were copper and cobalt, since with their presence it is possible to reduce the optical band gap value to 2,0 eV, a value within the optimal range of optical band gaps for solar fuel production processes. When such doping agents were present into the IZM-5 gel, it was found that the expected diffraction pattern was not obtained, but one of a new material, entitled ITQ-76. As with zeolites, the firsts attempts to allow accessibility to photoactive sites was about releasing the microporosity, the internal surface, by removing the organic structure directing agent used during the synthesis process. Because no strategy was successful, it was alternatively attempted to enhance the external surface (grain surface or mesoporosity). Of the different strategies tested, it was found that varying the gel composition was the most successful one. The insertion of saccharides, previously studied in the literature as mesoporosity agents, and increasing the synthesis gel viscosity in order to decrease the final crystal size were tested. However, the presence of saccharides did not lead to the formation of a mesoporous system. The improvement in accessibility was due to the decrease of particle sizes. By increasing the gel viscosity it was also possible to decrease the average size of the crystals and consequently increase the external surface area. After the modification of the structures under study in order to obtain a wide range of properties, their photocatalytic performance was evaluated by using the water splitting reaction. A volcano-like relationship seemed to exist between photocatalytic performance and the external surface area. According to the literature reviewed, this behavior might be explained by the balance between the increase of available active centers and the increase of surface defects which are potential recombination sites. Regarding the relation between the photocatalytic performance and the optical band gap value, again a volcano-like relationship seems to exist. According to the reviewed bibliography, it was found that with the reduction of the optical band gap value the number of absorbed photons increases and, as such, the performance is expected to increase. However, it is necessary that the photogenerated charges have a sufficient potential to participate in the desired reaction. As a result, below a certain optical band gap value, the photogenerated charges no longer have sufficient potential and, as such, the performance decreases. Of the different samples tested, those modified with sucrose stand out as having the best performance. So far it was not possible to unravel the phenomenon behind those enhanced reactivity. Hence, a more detailed characterization of these samples is necessary in order to understand how the presence of the organic component influences the electronic structure of the material and, consequently, its performance. It would also be important to assess the stability of the organic component during the reaction, more specifically to verify that it does not undergo an oxidation process that might produce protons, which are then able to form dihydrogen. / Silva Gaspar, B. (2024). Porous Sulfur-Based Materials for Photocatalytic Applications [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202895

γ-TiAl based alloys have attracted considerable research interest in the past few decades and have gained niche high temperature applications in aero-engines and automobiles. As high temperature structural materials, these alloys require stable microstructures. This thesis aims at addressing knowledge gaps in the understanding of microstructural stability in two technologically important γ-TiAl based alloys in different microstructures, viz. fully lamellar (FL) and duplex. Creep and exposure tests were complemented with a variety of microstructural characterization tools (SEM, EBSD, TEM, XRD). Density functional theory based calculations were also performed to further the understanding of stability of phases. In the first part of the thesis, microstructural stability of a FL microstructure was studied under creep and high temperature exposure conditions. An aim of these studies was to probe the effect of stress orientation with respect to lamellar plates on microstructural changes during primary creep. It was observed that retention of excess α2 resulted in an unstable microstructure and so under stress and temperature, excess α2 was lost. However, depending on stress orientation, the sequence of precipitates formed was different. In particular, for certain stress orientations, the formation of the non-equilibrium C14 phase was observed. The stress dependence of microstructural evolution was found to be stem from internal stresses due to lattice misfit and elastic moduli mismatch between α2 and γ. In the second part of this thesis, microstructural stability of a duplex alloy was probed, with an emphasis on understanding mechanisms that lead to tertiary creep. The as-extruded microstructure consisted of bands of equiaxed grains and lamellar grains. During creep, loss of lamellar grains was observed and this was attended by kinking of laths and formation of dynamically recrystallized equiaxed grains. Significant dislocation activity was seen in both lamellar and equiaxed grains at all stages of creep. Initially, dislocation activity leads to strengthening and primary creep behavior, but at later stages, it triggers dynamic recrystallization. Dynamic recrystallization was found to be the rate controlling creep mechanism. Accelerating creep behavior was due to strain localization during the constant load tensile test resulting from microstructural instabilities such as kinking.

Orientador: José Luiz Laus / Banca: Auero Evangelista Santana / Banca: Thiago Luiz de Salles Gomes / Resumo: Avaliaram-se descritivamente, à clínica, à histopatologia e à imunoistoquímica (ki 67- marcador de proliferação celular) os resultados, da cicatrização da córnea, após ceratoplastias lamelares com membrana de celulose microfibrilar em coelhos. Para tal, utilizaram-se 30 coelhos , distribuídos em 5 grupos de 6 animais, avaliados por até 60 dias de pós operatório. A avaliação clínica revelou manifestações moderadas de edema, blefaroespasmos, fotofobia desde o segundo dia, evoluindo para formas discretas ou ausentes a partir do sétimo dia, onde observou-se clinicamente o reparo do defeito da córnea. A histopatologia revelou uma fina camada de células escamosas, recobrindo totalmente a área lesada, aos sete dias, e com leve infiltrado de células polimorfonucleares. Observou-se a presença de vasos no epitélio a partir do 15º dia , com regressão aos 48º dias .A imunoistoquímica mostrou aumento de células em proliferação aos 15 dias no epitélio (p= 0,049) e aos trinta dias no estroma (p= 0,042). Frente aos resultados obtidos, há como admitir que mesmo com o defeito corneal concluído, aos sete dias, o sistema de defesa celular ainda se manteve ativo, pois a proliferação celular no epitélio se mostrou mais intensa aos 15 dias de observação ,conforme demonstrado imunoistoquimicamente. Onde nesse período ocorreu remodelamento e adesão epitelial da córnea, características satisfatórias em ceratoplastia lamelar em coelhos . / Abstract: Were evaluated the clinic, the histopathology and immunohistochemistry (ki 67 - marker of cell proliferation), the results of the membrane of cellulose in lamellar keratoplasty in rabbits. To this end, 30 rabbits were used, divided into 5 groups of 6 animals, assessed by up to 60 days of post-operative. The assessment showed clinical manifestations of moderate swelling, blefarospasmos, photophobia since the second day, evolving into discrete forms or absent from the seventh day, where there was clinically repair the defect of the cornea. The histopathology revealed a thin layer of squamous cells, completely covering the injured area, the seven days, and with mild infiltration of polymorphonuclear cells. There was the presence of vessels in the epithelium from the 15 th day, with regression of days to 48. Immunohistochemistry showed increased cell proliferation in the 15 days in the epithelium (p = 0049) and the thirty days in the stroma (p = 0042) . Facing the results achieved, as there admit that even with the beginning of healing, and with the defect of the cornea closed to seven days, the system of defence cell remained active, as in the epithelial cell proliferation was more intense at 15 days, as shown imunoistochemistry. Where in that period showed epithelial remodeling and membership, characteristics satisfactory in lamellar keratoplasty in rabbits. / Mestre

O objetivo desta pesquisa foi desenvolver e aperfeiçoar uma formulação com fase gel lamelar contendo óleo de Calendula officinalis e avaliar seu potencial na atividade cicatrizante de úlceras em ratos. A formulação estudada possui valor de EHL 6,0, constituída por óleo de calêndula e sistema tensoativo formado por derivados etoxilados dos alcoóis cetílico e estearílico (Ceteth 2/Steareth 20). Primeiramente, determinou-se a região do diagrama ternário de fases em que se encontravam as emulsões com fase gel lamelares (EFGL), macroscopicamente estáveis. Em seguida foi avaliada a estabilidade do sistema e parâmetros que poderiam influenciar na formação das estruturas anisotrópicas. Avaliou-se o comportamento das emulsões utilizando o teste de perda de massa por evaporação. Na avaliação in vitro, foram realizados testes de citotoxidade do óleo de calêndula frente às células de fibroblastos da linhagem L929 através do ensaio de apoptose e necrose. O teste in vivo foi realizado através do Índice de Cicatrização de Úlceras (ICU) no modelo em dorso de ratos (úlcera excisional contrátil) a fim de avaliar o potencial cicatrizante da emulsão proposta comparando com o sham (grupo controle). As úlceras foram avaliadas mediante análise de imagem nos tempos de 0, 2, 7, 14 e 21 dias após o procedimento cirúrgico. A EFGL demonstrou maior estabilidade frente aos testes de estabilidade preliminar e acelerada em relação as demais formulações. Além disso, esta formulação demonstrou menor área de histerese (tixotropia), portanto menor grau de espalhabilidade e com maior tempo de contato com a úlcera. Durante a evaporação das emulsões houve manutenção das estruturas anisotrópicas O óleo bruto da Calendula officinalis não apresentou interferência na via da apoptose e necrose na concentração de até 1000 ?g/mL em fibroblastos L929. A formulação proposta promoveu melhor cicatrização no modelo de úlcera cutânea (ICU) na região dorsal de ratos, supondo- se modular a fase inflamatória do processo de cicatrização, pois o maior recrutamento de células inflamatórias bem como a colagênese, diminuída no grupo EFGL, foram fatores essenciais que permitiram a total reepitelização das úlceras cutâneas. Portanto, pode-se concluir que a metodologia utilizada nesta pesquisa foi útil para a obtenção de emulsões com fase gel lamelar, sendo que a formação dessa estrutura é importante para a estabilidade do sistema, podendo ser utilizada como uma formulação viável e eficaz no processo cicatricial de feridas. / The aim of this research was to improve a lamellar gel phase emulsion containing Calendula officinalis oil and to investigate its potential as a modern wound dressing. First, we determined the region of the ternary phase diagram in which the emulsions were stable and we also evaluated the intrinsic stability of the system and the action of some parameters which may influence the formation of lamellar gel phase. In addition, we analyzed the samples\' behavior during the evaporation process. Moreover, an in vitro cytotoxicity assay of the calendula oil was performed in order to evaluate apoptosis and necrosis in fibroblast cell line L929. Then, an in vivo test was carried out by the wound healing rate (WHR), using a specific model of ulcer in rats (excisional contractile ulcer), in order to assess potential healing of the proposed emulsion (LGP) by comparing with the sham group. The ulcers were evaluated by image analysis at 0, 2, 7, 14 and 21 days after surgery. The emulsion 6 \'showed greater stability in the preliminary and accelerated stability tests in relation to the previous studied formulation. Moreover, this formulation presented more compatible characteristics, because it showed smaller hysteresis area of ? (thixotropy), therefore a lower degree of spreadability and, accordingly, the formulation may increase contact span with ulcer, which is a desirable characteristic. During evaporation of the emulsions, the anisotropic structures were maintained, but their type varied depending on the decreased amount of water in the system. The crude oil of Calendula officinalis showed no interference with the pathway of apoptosis and necrosis in the concentration of 1000 mg / mL in L929 fibroblasts. The proposed model has promoted better wound healing rate in the ulcers in the dorsal region of rats. It seemed to modulate the inflammatory phase of the healing process, because of the increased recruitment of inflammatory cells as well as collagenesis, once LGP emulsion decreased in the group, were factors essential that allowed total reepithelialization of skin ulcers in rats treated with LGP emulsion. In conclusion, this study produced an enhanced and useful LGP which can be used as a new approach to stimulate the healing process and treat wounds efficiently.

Compostos lamelares do tipo da hidrotalcita ou hidróxidos duplos lamelares (HDL), são materiais que possuem notáveis propriedades estruturais, químicas, eletrônicas, iônicas, ópticas e magnéticas. Em função dessas propriedades, os HDL apresentam uma diversidade de aplicações tais como adsorventes e catalisadores. Este trabalho tem por objetivo utilizar polímeros e macromoléculas na preparação e caracterização de HDL, visando melhorar as propriedades texturais dos HDL de MgAl-CO3 preparados em meio contendo polímeros orgânicos ou a intercalação direta de dendrímeros tipo PAMAM de gerações -0,5 e +0,5 em HDL do sistema Zn/Al. Os HDL de MgAl-CO3 foram preparados pela adaptação do método de coprecipitação a pH decrescente, com a presença de polímeros solubilizados no meio, como molde. Os materiais foram caracterizados por difração de Raios X, análise termogravimétrica, espectroscopia no infravermelho e medidas de área superficial por BET. Baseando-se nos resultados obtidos, pode-se concluir que propriedades texturais dos HDL preparados são modificadas, quando na presença de alguns polímeros. Na maioria dos casos, os valores calculados de área superficial específica foram mais elevados, em comparação com aquele obtido para o HDL preparado em meio reacional sem polímero. Isto pode ser explicado pela diminuição do tamanho de partículas e aumento no diâmetro médio de poros dos materiais preparados, provocada pela presença de polímeros no meio reacional. Os HDL intercalados com dendrímeros PAMAM G-0,5 e PAMAM G+0,5 foram preparados por duas rotas diferentes: coprecipitação a pH constante e troca iônica em fase dupla. Os materiais obtidos foram caracterizados por meio de difração de Raios X, análise de termogravimétrica associada à espectrometria de massas e espectroscopia no infravermelho. Utilizando os dois procedimentos de preparação, a intercalação de PAMAM G-0,5 deu origem a HDL com os mesmos espaçamentos basais, concordando com a intercalação dos ânions do dendrímero em um arranjo perpendicular à lamela do HDL, enquanto que para a intercalação do PAMAM G+0,5, espaçamentos basais muito menores do que o tamanho da molécula foram obtidos. A diferença entre a distância interlamelar observada e a esperada pode ser explicada por um arranjo peculiar das moléculas desse dendrímero em uma forma elipsoidal, devido às interações intramoleculares. Espectros no infravermelho confirmam a presença dos dendrímeros nos materiais Zn2Al-PAMAM G-0,5 e Zn2Al-PAMAM G+0,5. Finalmente, a presença destes dendrímeros foi confirmada por análise térmica associada com espectrometria de massas. Os estudos de Raios X com variação de temperatura in situ e as análises termogravimétricas revelaram que o material obtido pela intercalação do PAMAM G+0,5 é termicamente menos estável do que aquele intercalado com PAMAM G-0,5, concordando com a diferença de estabilidade entre os dendrímeros livres. / Hydrotalcite-like lamellar compounds or layered double hydroxides (LDH) are materials that present notable structural, chemical, electronic, ionic, optical and magnetic properties. Depending on these properties, the LDH present a great variety of applications such as adsorbents and catalysts. The aim of this work is to prepare and to characterize MgAl-CO3-LDH prepared in aqueous media containing organic polymer to improve textural properties, and to prepare HDL by intercalation of dendrimer (PAMAM) of generations -0.5 and +0.5 in ZnAl-HDL. MgAl-CO3-HDL samples were prepared by an adaptation of the coprecipitation method at decreasing pH, with the presence of polymers in the aqueous media as template. The materials were characterized by powder X-ray diffraction, termogravimetric analysis, infrared spectroscopy and BET isotherms. Based on the obtained results, it can be concluded that the textural properties of the prepared LDH were modified. The calculated values of specific surface area were higher in most of the cases compared with those obtained by the LDH prepared without polymer due to a decrease of the particle size and an increase in the average pore diameter of the prepared materials due to the presence of polymers. HDL with intercalated (PAMAM) dendrimers G-0.5 and G+0.5 were prepared by two different methods: coprecipitation at constant pH, and ionic exchange in double phase. The obtained materials were characterized by powder X-ray diffraction, thermal gravimetric analysis associated with mass spectrometry, and infrared spectroscopy. X-ray powder diffraction patterns exhibit the characteristic profiles of the lamellar materials with basal spacing depending on the nature of the dendrimer. For both preparation methods, the intercalation of PAMAM G-0.5 gives rise to LDH with basal spacing in agreement with the dendrimer molecules perpendicular to the layer of the host structure, while for PAMAM G+0.5 a basal spacing smaller than the molecule size was obtained. The difference between the obtained and the expected value is explained by an accommodation of the dendrimer molecule in an ellipsoidal shape, due to the intra-molecular interactions. Infrared spectra confirm the presence of dendrimers in the Zn2Al-PAMAM G-0.5 and Zn2Al-PAMAM G+0.5 materials. Finally, thermal analyses associated with mass spectrometry confirm the presence of these dendrimers. Powder X-ray diffraction with in situ temperature variation reveals that the material obtained by the PAMAM G+0.5 intercalation is thermally less stable than that prepared by PAMAM G-0.5 intercalation, in agreement with the difference in the thermal stability of the free dendrimers.

L’évolution des structures poreuses du graphite et de la vermiculite expansés a été étudiée insitu sous pression uniaxiale. Les propriétés d'un matériau résultant des propriétés intrinsèques à lamatrice et de celles dues à la porosité, les études faites dans ce travail ont porté sur deux échellesdifférentes. Les évolutions structurales de la structure cristalline du graphite et de la vermiculite ontd'abord été étudiées à haute pression en cellule à enclumes de diamant. Cette partie du travail a permisd'établir les équations d'état de la vermiculite et de contribuer, de manière significative, à lacaractérisation de la phase haute pression du graphite: une nouvelle phase, le Carbone Z, a étéproposée après l’analyse des données de la spectroscopie Raman couplée aux simulations. Desdéveloppements techniques ont été particulièrement réalisés pour permettre d’étudier in situl'évolution de la porosité sous pression par diffusion aux petits angles sous pression. L’application dumodèle fractale à l’analyse des données a permis de suivre l’évolution de la dimension fractale et de lasurface spécifique apparente. Les échantillons étudiés sont des formes comprimées de graphite et devermiculite expansés dans lesquelles les plans basaux des cristallites ont une orientation préférentielle.Sous pression uniaxiale, la structure poreuse du graphite expansé comprimé évolue à travers uneffondrement irréversible des pores ou un cisaillement de la matrice suivant l'orientation de la pressionappliquée par rapport à l'orientation préférentielle des plans basaux des cristallites. Des expériencescomplémentaires de mesures électriques et de mesures de la porosité par intrusion de mercure ontpermis de confirmer ces modèles proposés. Dans la vermiculite expansée comprimée, les fissuresapparaissent, de manière générale, sous l’effet de la pression uniaxiale. / The porous structure of expanded graphite and expanded vermiculite has been studied insitu under uniaxial stress. The properties of a porous material being related to the matrix and to theporosity, the in situ evolution under of the crystalline structure (of the matrix) under high pressurehave been first investigated using diamond anvil cell. The equation of state of expanded vermiculitehas been established. This first part of this work allowed giving a particular insight to the study of theunsolved high pressure phase of graphite. Combining Raman scattering data and calculations, a newstructure, called Z-Carbon, has been proposed. Thanks to the specific technical developments of thiswork, the porosities of expanded graphite and expanded vermiculite based systems have been studiedin situ under uniaxial stress. The used of fractal model in data analysis allowed following the evolutionof the fractal dimension and of the apparent specific surface The studied samples were made ofcompressed forms of expanded graphite and expanded vermiculite in which the basal plane of thecrystallites have a preferential orientation. The uniaxial stress was taken perpendicular and parallel tothis preferential direction. The porous structure of the expanded graphite sample was found to undergoan irreversible collapse of the pores or a cracks and creation and propagation. Additional electrical andporosity measurements supported the proposed models. In the expanded vermiculite based systems,the crack apparition was observed under uniaxial stress.