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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

Desenvolvimento e avalia??o do potencial antioxidante de uma nanoemuls?o de uso t?pico

Selbach, Sarah Ledur 29 February 2016 (has links)
Submitted by PPG Biotecnologia Farmac?utica (mpbf@pucrs.br) on 2017-08-01T13:00:08Z No. of bitstreams: 1 SARAH_LEDUR_SELBACH_DIS.pdf: 2769655 bytes, checksum: 75da9b372aa505302e3bba0e64bdc393 (MD5) / Rejected by Caroline Xavier (caroline.xavier@pucrs.br), reason: Devolvido devido a diverg?ncia entre o t?tulo de capa e o t?tulo da folha de rosto. Confirmar qual o correto. on 2017-08-04T13:28:42Z (GMT) / Submitted by PPG Biotecnologia Farmac?utica (mpbf@pucrs.br) on 2017-08-08T13:07:34Z No. of bitstreams: 1 SARAH_LEDUR_SELBACH_DIS.pdf: 2769655 bytes, checksum: 75da9b372aa505302e3bba0e64bdc393 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-08-10T18:18:37Z (GMT) No. of bitstreams: 1 SARAH_LEDUR_SELBACH_DIS.pdf: 2769655 bytes, checksum: 75da9b372aa505302e3bba0e64bdc393 (MD5) / Made available in DSpace on 2017-08-10T18:24:39Z (GMT). No. of bitstreams: 1 SARAH_LEDUR_SELBACH_DIS.pdf: 2769655 bytes, checksum: 75da9b372aa505302e3bba0e64bdc393 (MD5) Previous issue date: 2016-02-29 / According to INCA (National Institute of Cancer) the cases of skin cancer are increasing exponentially, and it is the world's largest incidence. The increase in ultraviolet index, due to the depletion of the ozone layer, and excessive sun exposure contribute to this fact. The formation of reactive oxygen species (ROS) can be from endogenous and exogenous factors, mainly by exposure to ultraviolet (UV). This are directly linked to the development of several types of cancer, especially skin cancer and photoaging. ROS or free radicals alter the DNA and other biomolecules of the skin, causing genetic mutations that promote and induce cancer incidence. Consequently, the search for new antioxidant substances for topical use is of utmost importance for the prevention of photodamage and skin cancer. This project of master dregree aims to develop a topical nanoemulsion containing these active substances Green tea (Camellia sinensis) and Buriti Oil (Mauritia flexuosa), which have antioxidant properties, and to study their stability in vitro and assess its properties. As a result it is expected to develop a cosmetic raw material that meets a demand of the consumer market, contributing to the prevention of skin cancer and to decrease the signs of cutaneous photoaging. / Segundo o INCA (Instituto Nacional de C?ncer), o c?ncer de pele possui a maior incid?ncia mundial e seus casos v?m aumentando exponencialmente. O aumento do ?ndice ultravioleta devido ? diminui??o da camada de oz?nio e a exposi??o solar excessiva contribuem para este fato. A forma??o de esp?cies reativas de oxig?nio (EROs), se d? por fatores end?genos e ex?genos, principalmente pela exposi??o aos raios ultravioleta (UV). Esta est? diretamente ligada ao desenvolvimento de diversos tipos de c?ncer, especialmente o de pele. As EROs, ou radicais livres, alteram o DNA e demais biomol?culas da pele, ocasionando muta??es gen?ticas que favorecem e induzem a incid?ncia de c?ncer, e causam fotoenvelhecimento. Consequentemente, a busca de novos ativos com propriedades antioxidantes de uso t?pico ? de extrema import?ncia para a preven??o de fotodanos e c?ncer de pele. Este projeto de mestrado teve como objetivo desenvolver uma nanoemuls?o t?pica contendo estas subst?ncias ativas, Ch? Verde (Camellia sinensis) e ?leo de Buriti (Mauritia flexuosa), que apresentam propriedades antioxidantes, estudar sua estabilidade e avaliar in vitro suas propriedades. Como resultado, espera-se obter um insumo cosm?tico que atenda uma demanda do mercado de consumidores, contribuindo para preven??o do c?ncer de pele e para diminui??o dos sinais do fotoenvelhecimento cut?neo.
2

Obten??o de diesel verde por craqueamento termocatal?tico de ?leo de buriti (Mauritia flexuosa L.) sobre materiais nanoestruturados do tipo LaSBA-15 / Obten??o de diesel verde por craqueamento termocatal?tico de ?leo de buriti (Mauritia flexuosa L.) sobre materiais nanoestruturados do tipo LaSBA-15

Luz Junior, Geraldo Eduardo da 26 April 2010 (has links)
Made available in DSpace on 2014-12-17T15:42:08Z (GMT). No. of bitstreams: 1 Geraldo Eduardo da Luz Junior_TESE.pdf: 1318067 bytes, checksum: bc521809cc7c08b9ef99f31a1034f3a2 (MD5) Previous issue date: 2010-04-26 / In order to obtain a biofuel similar to mineral diesel, lanthanum-incorporated SBA- 15 nanostructured materials, LaSBA-15(pH), with different Si/La molar ratios (75, 50, 25), were synthesized in a two-steps hydrothermal procedure, with pH-adjusting of the synthesis gel at 6, and were used like catalytic solids in the buriti oil thermal catalytic cracking. These solids were characterized by X-ray fluorescence (XRF), powder X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), infrared spectroscopy (FTIR), nitrogen porosimetry and ethanol dehydration, aiming to active sites identify. Taken together, the analyses indicated that the synthesis method has employed to obtain materials highly ordered mesostructures with large average pore sizes and high surface area, besides suggested that the lanthanum was incorporated in the SBA-15 both into the framework as well as within the mesopores. Catalytic dehydration of ethanol over the LaSBA-15(pH) products has shown that they have weak Lewis acid and basic functionalities, indicative of the presence of lanthanum oxide in these samples, especially on the La75SBA-15(pH) sample, which has presented the highest selectivity to ethylene. The buriti oil thermal and thermal catalytic cracking, realized from the room temperature to 450 ?C in a simple distillation system, has allowed obtaining two liquid fractions, each consisting of two phases, one aqueous and another organic, organic liquid (OL). The OL obtained from first fractions has shown high acid index, even in the thermal catalytic process. One the other hand, OL coming from second ones, called green diesel (GD), have presented low acid index, particularly that one obtained from the thermal catalytic process realized over LaSBA-15(pH) samples. The acid sites presence in these samples, associated to their large average pore sizes and high surface areas, have allowed them, especially the La75SBA-15(pH), to present deoxygenating activity in the buriti oil thermal catalytic cracking, providing an oxygenates content reduction, particularly carboxylic acids, in the GD. Furthermore, the GD comes from the second liquid fraction obtained in the buriti oil thermal catalytic cracking over this latest solid sample has shown hydrocarbons composition and physic-chemical properties similar to that mineral diesel, beyond sulfur content low / Com o objetivo de obter um biocombust?vel semelhante ao diesel mineral, materiais nano-estruturados do tipo SBA-15 com lant?nio incorporado, LaSBA-15(pH), com raz?es molares Si/La = 75, 50 e 25, foram sintetizados em dois est?gios, com ajuste do pH do gel de s?ntese a 6, e utilizados como s?lidos catal?ticos no craqueamento termocatal?tico de ?leo de buriti. As amostras s?lidas foram caracterizadas por fluoresc?ncia de raios-X (FRX), difra??o de raios-X (DRX), an?lise termogravim?trica (TG/DTG), espectroscopia na regi?o do infravermelho (FTIR), adsor??o-dessor??o de nitrog?nio e desidrata??o de etanol, para identifica??o dos s?tios ativos. Os resultados destas caracteriza??es indicaram que o m?todo de s?ntese empregado proporcionou a obten??o de materiais mesoestruturados altamente ordenados com grande di?metro m?dio de poros e elevada ?rea superficial, al?m de sugerir que o lant?nio foi incorporado na SBA-15 tanto no interior das paredes, quanto dentro dos mesoporos. A desidrata??o catal?tica de etanol sobre os s?lidos LaSBA-15(pH) mostrou que eles apresentam s?tios ?cidos e b?sicos de Lewis, indicativo da presen?a de ?xido de lant?nio nestes, especialmente na amostra La75SBA-15(pH), que apresentou a maior seletividade para etileno. Os craqueamentos t?rmico e termocatal?ticos do ?leo de buriti, realizados da temperatura ambiente a 450 ?C em um sistema de destila??o simples, possibilitaram a obten??o de duas fra??es l?quidas, compostas por duas fases, uma aquosa e outra org?nica, l?quido org?nico (LO). O LO obtido a partir das primeiras fra??es apresentou ?ndice de acidez muito elevado, at? mesmo nos processos termocatal?ticos. Por outro lado, o LO oriundo das segundas fra??es, denominado de diesel verde (DV), apresentou baixo ?ndice de acidez, particularmente aquele obtido nos processos realizados sobre as amostras LaSBA-15(pH). Os s?tios ?cidos presentes nestas amostras, associados aos seus grandes di?metros m?dios de poros e ?s elevadas ?reas superficiais, permitiram que elas, especialmente a La75SBA-15(pH), apresentassem atividade desoxigenante no craqueamento temocatal?tico do ?leo de buriti, ocasionando uma diminui??o da concentra??o de oxigenados no DV, particularmente ?cidos carbox?licos. Al?m disso, o DV obtido sobre esta ?ltima amostra s?lida apresentou composi??o de hidrocarbonetos e propriedades f?sico-qu?micas semelhantes ?s do diesel mineral, al?m de um baixo teor de enxofre

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