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Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2022-10-18T12:51:23Z No. of bitstreams: 1 2020 - Debora Baptista Pereira.pdf: 2191500 bytes, checksum: ba51deb9e480726e604fe5f7fc5aa8cb (MD5) Made available in DSpace on 2022-10-18T12:51:24Z (GMT). No. of bitstreams: 1 2020 - Debora Baptista Pereira.pdf: 2191500 bytes, checksum: ba51deb9e480726e604fe5f7fc5aa8cb (MD5) Previous issue date: 2020-02-18 CAPES - Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior Damage to cartilaginous and bone tissue is caused by several factors such as trauma, inflammation and aging and can lead to tissue loss with functional impairment. Because it is a fabric that has low or even no regenerative capacity, treatment and recovery is difficult. In an attempt to overcome these problems, researchers have developed and perfected different regenerative techniques based on the use of polymeric biomaterials. Along with these, it is of interest to use a drug with beneficial properties to assist the treatment of cartilage areas damaged by the wear and tear caused by inflammation and injury. Atorvastatin (ATV), a cholesterol-lowering statin, has shown interesting secondary actions in several studies, such as bone anabolism due to its prolonged use. However, high doses of this input are necessary for this purpose and the commercialized forms of this drug are tablets for oral use, with little direction for cartilage and bone tissue. Thus, the objective of the work was to develop and evaluate polymeric films for controlled release of atorvastatin. In this context, films composed of polycaprolactone (PCL), a biodegradable synthetic polymer containing ATV, were developed. The films were produced using the solvent casting technique using two different methodologies? without and with drug solubilization (methods 1 and 2 respectively) and with different drug / polymer proportions. These were characterized by scanning electron microscopy (SEM), SEM coupled to dispersive energy spectroscopy (EDS), X-ray diffraction (DRX), Fourier transform infrared spectrometry (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry. (DSC). According to the results obtained by these techniques, it was possible to conclude that the films produced by method 2 were considered better because they present greater homogeneity in the dispersion of the drug. The release of the drug present in the best films was evaluated in a phosphate buffer solution (pH 7.4) at 37 ? C and rotation of 75 rpm in a dissolver with fiber optic sensors, recording the release at predefined times for 5 days. Through this test it was demonstrated that it was released in the studied time in a prolonged way, and that both the material morphology and the diffusion process have an influence on the release mechanism, suggesting that the material on the surface is released first and then, the film is eroded, making the drug available. The degradation of the films was observed through the SEM performed after the release, proving the erosion process. Therefore, the developed films have potential application for controlled release of drugs, and may in the future be used as a biomaterial for the regeneration of cartilage tissue Danos ao tecido cartilaginoso e ?sseo s?o causados por diversos fatores como traumas, inflama??es e envelhecimento e podem acarretar na perda tecidual com comprometimento funcional. Por ser um tecido que apresenta baixa ou at? mesmo nenhuma capacidade regenerativa, se torna dif?cil o tratamento e recupera??o. Na tentativa de superar estes problemas, pesquisadores t?m desenvolvido e aperfei?oado diferentes t?cnicas regenerativas baseadas na utiliza??o de biomateriais polim?ricos. Junto a esses, ? de interesse utilizar um f?rmaco com propriedades ben?ficas para auxiliar o tratamento das ?reas cartilaginosas danificadas pelo desgaste causado por inflama??es e les?es. A atorvastatina (ATV), estatina redutora de colesterol, tem exibido em diversos estudos a??es secund?rias interessantes, como anabolismo ?sseo devido ao seu uso prolongado. Entretanto, s?o necess?rias altas doses desse insumo para esse efeito e as formas comercializadas desse f?rmaco s?o comprimidos de uso oral, tendo pouco direcionamento para o tecido cartilaginoso e ?sseo. Dessa forma, o objetivo do trabalho foi desenvolver e avaliar filmes polim?ricos para libera??o controlada de atorvastatina. Nesse contexto, foram desenvolvidos, filmes compostos por policaprolactona (PCL), um pol?mero sint?tico biodegrad?vel, contendo ATV. Os filmes foram produzidos atrav?s da t?cnica de solvent casting utilizando duas metodologias diferentes, sem e com solubiliza??o do f?rmaco (m?todos 1 e 2 respectivamente) e com diferentes propor??es f?rmaco/pol?mero. Esses foram caracterizados pelas t?cnicas de microscopia eletr?nica de varredura (MEV), MEV acoplado a espectroscopia de energia dispersiva (EDS), difra??o de raios X (DRX), espectroscopia no infravermelho com transformada de Fourier (FTIR), an?lise termogravim?trica (TGA) e calorimetria diferencial de varredura (DSC). De acordo com os resultados obtidos por essas t?cnicas, foi poss?vel concluir que os filmes produzidos pelo m?todo 2 foram considerados melhores por apresentarem maior homogeneidade na dispers?o do f?rmaco. A libera??o do f?rmaco presente nos melhores filmes foi avaliada em solu??o tamp?o fosfato (pH 7,4) a 37 0C e rota??o de 75 rpm em um dissolutor com sensores de fibra ?tica, registrando a libera??o em tempos pr?definidos por 5 dias. Atrav?s desse teste demonstrou-se que o mesmo foi liberado no tempo estudado de forma prolongada, e que tanto a morfologia do material quanto o processo de difus?o t?m influ?ncia no mecanismo de libera??o, sugerindo que o material na superf?cie ? liberado primeiro e em seguida, o filme sofre eros?o, disponibilizando o f?rmaco. A degrada??o dos filmes foi observada atrav?s do MEV realizada ap?s a libera??o, comprovando o processo de eros?o. Portanto, os filmes desenvolvidos t?m potencial aplica??o para libera??o controlada de f?rmacos, podendo futuramente ser utilizado como biomaterial para regenera??o do tecido cartilaginoso

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2021-10-26T14:35:03Z No. of bitstreams: 1 2019 - Vin?cius Guedes Gobbi.pdf: 2629644 bytes, checksum: e16011b6f0654dc0b0a4052ee22f8252 (MD5) Made available in DSpace on 2021-10-26T14:35:03Z (GMT). No. of bitstreams: 1 2019 - Vin?cius Guedes Gobbi.pdf: 2629644 bytes, checksum: e16011b6f0654dc0b0a4052ee22f8252 (MD5) Previous issue date: 2019-07-01 CAPES - Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior Nitrosamines are considered carcinogenic by a large number of international organizations and regulatory authorities. During the vulcanization process, the formation of nitrosamines occurs, mainly N-nitroso-dimethylamine, N-nitroso-diethylamine, N-nitroso-morpholine. Accelerators are the main cause of the emergence of nitrosamines, such as tetramethyl-thiuram disulphide (TMTD), which contains in its molecular structure secondary amine groups. Some accelerators exhibit kinetic behavior similar to TMTD such as tetrabenzylthiuram disulphide (TBzTD) and zinc dibenzyl dithiocarbamate (ZBEC) and, according to the literature, do not release noxious nitrosamines into the environment. The objective of the present work was the comparison of compounds presenting the isobutylene-isoprene (IIR) elastomer by means of a standard formulation used for confection of air chambers, and the production of compounds using the TBzTD and ZBEC accelerators and the standard compound using TMTD. For this, an experimental design was proposed for the production of these compounds in a laboratory banbury. Through the rheological characterization, it was noticed that the TBzTD and ZBEC accelerators do not present the same kinetic behavior, especially when the maximum torque (MH) values were analyzed during vulcanization in the IIR elastomer. The MH experimental data obtained were correlated through the least square method (RNL-MMQ) and the interpolation technique (TPSIM), allowing the evaluation of the effect of TBzTD and ZBEC accelerators on the compounds produced. In addition, through the physical-mechanical and thermo-dynamic measurements, a decrease in mechanical properties was observed for the TBzTD and ZBEC accelerator compounds compared to the standard compound. Such observation is linked to the difference in formation of crosslinks during the vulcanization step between the accelerators studied. The results of FTIR and swelling indexes corroborated to the observed trend that the TMTD accelerator, unlike the TBzTD and ZBEC accelerators, promotes a greater formation of crosslinks than the accelerators compared As nitrosaminas s?o consideradas carcinog?nicas por um grande n?mero de organiza??es internacionais e autoridades reguladoras. Durante o processo de vulcaniza??o, ocorre a forma??o das nitrosaminas, principalmente os compostos N-nitroso-dimetilamina, a N-nitroso-dietilamina, a N-nitroso-morfolina. Os aceleradores s?o os principais causadores do surgimento das nitrosaminas, como o dissulfeto de tetrametil-tiuram (TMTD), que cont?m em sua estrutura molecular grupos de aminas secund?rias. Alguns aceleradores apresentam o comportamento cin?tico semelhante ao TMTD como o dissulfeto de tetrabenzil-tiuram (TBzTD) e o dibenzil-ditiocarbamato de zinco (ZBEC) e, de acordo com a literatura, n?o liberam nitrosaminas noc?veis ao meio ambiente. O objetivo do presente trabalho foi a compara??o de compostos apresentando o elast?mero isobutileno-isopreno (IIR), atrav?s de uma formula??o padr?o utilizada para confec??o de c?maras de ar, e a produ??o de compostos utilizando os aceleradores TBzTD e ZBEC e o composto padr?o utilizando TMTD. Para tal, foi proposto um planejamento experimental para a produ??o desses compostos em um banbury de laborat?rio. Atrav?s da caracteriza??o reol?gica notou-se que os aceleradores TBzTD e ZBEC n?o apresentam o mesmo comportamento cin?tico, principalmente quando analisado os valores de torque m?ximo (MH) durante a vulcaniza??o no elast?mero IIR. Os dados experimentais de MH obtidos foram correlacionados atrav?s do m?todo dos m?nimos quadrados (RNL-MMQ) e pela t?cnica de interpola??o (TPSIM) permitindo-se avaliar o efeito dos aceleradores TBzTD e ZBEC nos compostos produzidos. Al?m disso, atrav?s das medidas f?sico-mec?nicas e termo-din?micas, notou-se uma diminui??o nas propriedades mec?nicas para os compostos contendo acelerador TBzTD e ZBEC em compara??o ao composto padr?o. Tal observa??o est? ligado a diferen?a de forma??o de liga??es cruzadas durante a etapa de vulcaniza??o entre os aceleradores estudados. Os resultados de FTIR e ?ndice de inchamento realizados corroboraram para a tend?ndica observada de que o acelerador TMTD diferentemente dos aceleradores TBzTD e ZBEC promove uma maior forma??o de liga??es cruzadas que os aceleradores comparados

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-09T20:05:40Z No. of bitstreams: 1 2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5) Made available in DSpace on 2017-05-09T20:05:40Z (GMT). No. of bitstreams: 1 2016 - Melise Ferreira de Aguiar.pdf: 5763969 bytes, checksum: 9dcc7682d7ffab0b0a6ce4d1db704c10 (MD5) Previous issue date: 2016-12-12 CAPES Natural gas is extensively used in industries as well as in other sectors as an energy resource and, sometimes, it needs to undergo processes for the removal of impurities present in its composition. Among them are the sulfur compounds, which can cause damages to pipes and catalysts, making it necessary to develop and/or improve deep desulfurization methods. In this context, granular activated carbon was modified through two methods, oxidation using nitric acid, and impregnation using a ferric chloride solution. The resulting adsorbents were evaluated for their capacity of adsorbing seven sulfur compounds present in the synthetic natural gas sample, through their rupture curves. Afterwards, the adsorbents desorption was performed by using supercritical carbon dioxide under the conditions of 60?C at 100 bar, 150 bar and 200 bar. The results indicate that all the modification methods improved the sulfur compounds retention when compared to virgin activated carbon. The compound that had the greatest increase in the adsorption capacity after iron impregnation was the tert-butyl mercaptan (TBM), and with the activated carbon oxidized by HNO3 it was the dimethyl sulfide (DMS). Nevertheless, the supercritical conditions studied in the desorption stage were efficient only for the unmodified activated carbon. The adsorption capacities of both modified adsorbents after the regeneration were inferior to those capacities obtained in the first adsorption, then two hypotheses were investigated: (1) destruction of the newly created sites after regeneration; and (2) incomplete desorption in the studied supercritical conditions. Through other experiments it was proved that, after regeneration, there was no destruction of the newly created sites; therefore, further studies on the operating conditions are required in order to the modified adsorbents to achieve high regeneration capacities. O g?s natural ? utilizado nas ind?strias e em outros setores como fonte de energia e necessita, por vezes, de processos de remo??o das impurezas presentes em sua composi??o. Dentre elas est?o os compostos de enxofre, que provocam danos em tubula??es e catalisadores, sendo necess?rio o desenvolvimento e/ou o aperfei?oamento de m?todos para a dessulfuriza??o profunda. Nesse contexto, um carv?o ativado granular foi modificado por meio de dois m?todos, oxida??o utilizando ?cido n?trico e por impregna??o usando uma solu??o de cloreto de ferro III, os adsorventes resultantes foram avaliados quanto ? sua capacidade para adsorver sete compostos de enxofre presentes em uma amostra de g?s natural sint?tica, atrav?s das curvas de rupturas. Posteriormente, foi realizada a dessor??o dos adsorventes utilizando di?xido de carbono supercr?tico nas condi??es de 60 ?C a 100 bar, 150 bar e 200 bar. Os resultados indicam que todos os m?todos de modifica??o melhoraram a reten??o dos compostos sulfurados individuais em compara??o com o carv?o ativado virgem. O composto que obteve maior aumento da capacidade de adsor??o ap?s a impregna??o com ferro foi o terc-butilmercaptana (TBM), e com o carv?o ativado oxidado pelo HNO3 foi o metiletilsulfeto (DMS). J? as condi??es supercr?ticas estudadas na etapa de dessor??o foram eficientes somente para o carv?o ativado n?o modificado. As capacidades de adsor??o dos dois adsorventes modificados ap?s a regenera??o foram inferiores aos obtidos na primeira adsor??o, ent?o duas hip?teses foram investigadas: (1) destrui??o dos novos s?tios criados ap?s a regenera??o; e (2) dessor??o incompleta nas condi??es supercr?ticas estudadas. Atrav?s de outros experimentos comprovou-se que n?o houve ? destrui??o dos novos s?tios criados ap?s a regenera??o, sendo necess?rio um estudo mais profundo em rela??o ?s condi??es operacionais, a fim de alcan?ar altas capacidades de regenera??o dos adsorventes modificados.