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Determina??o dos coeficientes de atividade em dilui??o infinita de hidrocarbonetos em furfural e par?metros de flory em sistemas polim?ricos por HSSPME- GC/FID / Determination of activity coefficients at infinite dilution for hydrocarbons in furfural and flory parameters in polymeric systems using HS-SPMEGC/ FIDFurtado, Filipe Arantes 26 July 2012 (has links)
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Previous issue date: 2012-07-26 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / The main objective of this work was the development of a methodoly using the Solid Phase
Microextraction (SPME) on determinations of thermodynamic equilibrium data of liquid and
polymeric mixtures. Three methodologies were proposed for determination of infinite dilution activity
coefficient of solutes in liquid mixtures (??). The ?? values were determined for 9 hydrocarbons
in the solvent furfural at temperatures of 25, 35 and 45 ?C. The liquid-gas partition
coefficients were also determined in each studied temperature. On the experiments involving
liquid mixtures, high sorption of solvent was observed, which may lead to swelling the
polymer coating phase. Statistical tests were conducted after each experiments to measure
possible damages on fiber coatings. There was also proposed a methodology using the SPME
to determine the Flory Huggins parameter of the nine hydrocarbons used as solutes in
polydimethylsiloxane (PDMS) and polyacrylate (PA). The Flory parameter were determined
at temperature range of 25 to 80 ?C for the PDMS and 50 to 90 ?C for the PA. The proposed
methodologies were evaluated through comparison of the obtained data with literature. All the
results agreed with literature data. The Hildebrandt solubility parameter for PA was not
available on literature and was determined on these experiments for the first time / O principal objetivo deste trabalho foi o desenvolvimento de uma nova metodologia para
determina??o de dados de equil?brio termodin?mico em misturas l?quidas e polim?ricas. Tr?s
metodologias foram propostas utilizando a Microextra??o em Fase S?lida (SPME) para
determina??o dos coeficientes de atividade em dilui??o infinita (??) de sistemas l?quidos. Os
valores de ?? de 9 hidrocarbonetos foram determinados em furfural nas temperaturas de 25,
35 e 45 ?C. Foram determinados valores de coeficiente de parti??o l?quid-g?s (KLg) em cada
uma das temperaturas estudadas. Nos experimentos envolvendo as misturas l?quidas, foi
observada uma alta taxa de sor??o de solvente podendo ocasionar o inchamento e poss?vel
quebramento das fibras de SPME. Para verificar o poss?vel inchamento, foram conduzidos
testes estat?sticos antes e depois de cada amostragem. Foi proposto ainda uma metodologia
para determinar os par?metros de Flory em polidimetilsiloxano (PDMS) e poliacrilato (PA)
utilizando a SPME. Nesse caso, os mesmos 9 hidrocarbonetos tiveram seus par?metros de
Flory determinados na faixa de temperatura 25 a 80 ?C para o PDMS e de 50 a 90 ?C para o
PA. As metodologias foram avaliadas atrav?s da compara??o dos dados obtidos com dados da
literatura. Todos os resultados foram satisfat?rios, sendo ainda obtidos os valores dos
par?metros de solubilidade de Hildebrandt, que para o poliacrilato, eram inexistentes na
literatura
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Avalia??o da atividade antiviral de extratos obtidos da folha e fruto de Morinda citrifolia contra o v?rus dengueMoreira, Polyanna Silva 23 February 2017 (has links)
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Previous issue date: 2017-02-23 / A dengue ? uma arbovirose que afeta o homem, gerando uma problem?tica na sa?de p?blica do mundo, especialmente em pa?ses tropicais os quais apresentam condi??es que favorecem a dissemina??o do mosquito Aedes aegypti. Atualmente, dentre as v?rias estrat?gias para controle da doen?a, ainda n?o se tem uma vacina eficaz ou um antiviral capaz de combater essa infec??o. Assim, o objetivo do presente estudo foi avaliar a atividade antiviral de extratos obtidos da folha e frutos da planta Morinda citrifolia L. em cultura de c?lulas Vero infectadas com v?rus dengue-2 (DENV-2). Inicialmente foram obtidos os extratos brutos (hidroetan?lico) e as respectivas fra??es: hexano, clorof?rmio e acetato de etila, analisados por cromatografia. O teste de citotoxicidade do extrato bruto, res?duo aquoso e fra??es foram realizados em cultura de c?lulas Vero pelo m?todo MTT, nas concentra??es de 1000; 500; 250; 125; 62,5; 31,2 ?g/mL. O ensaio antiviral foi conduzido atrav?s das seguintes estrat?gias: c?lulas infectadas com DENV-2 (controle positivo); c?lulas mantidas com meio de cultura (controle negativo); c?lulas infectadas com DENV-2 e tratadas com o extrato ou fra??es. Ap?s cinco dias de infec??o a viabilidade celular foi avaliada pelo m?todo de MTT e o sobrenadante da cultura foi utilizado para quantifica??o viral por unidade formadora de placa (PFU). Os resultados demonstraram que a an?lise cromatogr?fica dos extratos e fra??es revelou bandas distintas e sugestivas de saponinas, terpenos e flavonoides. Tais extratos e fra??es n?o foram t?xicos para as culturas de c?lulas, com exce??o do tratamento das c?lulas com a fra??o clorof?rmio obtido da folha e as fra??es hexano e acetato de etila do fruto verde, levando a uma viabilidade pr?xima de 65%. No ensaio antiviral o controle positivo apresentou viabilidade celular em torno de 60% ap?s cinco dias de infec??o. No tratamento com os compostos obtidos da folha observou-se que ao adicionar a fra??o de acetato de etila ?s c?lulas infectadas, estas mantiveram uma viabilidade celular pr?ximo a 100% na concentra??o de 1000?g/mL e a 85% nas concentra??es de 500 e 250?g/mL. O tratamento com a fra??o hexano apresentou uma viabilidade superior ao controle positivo em todas as concentra??es. No entanto, na fra??o clorof?rmio, a viabilidade manteve-se elevada apenas nas concentra??es de 500 e 250?g/mL. O extrato bruto e a fra??o residual aquosa n?o demonstraram atividade antiviral. As c?lulas tratadas com o extrato e as diferentes fra??es obtidas dos frutos maduro e verde, apresentaram de um modo geral uma viabilidade celular pr?xima de 100% nas concentra??es de 500 e 1000 ?g/mL no fruto maduro e apenas 1000 ?g/mL no fruto verde, com exce??o das c?lulas que foram tratadas com a fra??o clorof?rmio, na qual n?o foi poss?vel observar nenhuma diferen?a significativa quando comparado ao controle positivo. Na quantifica??o viral observou-se que as c?lulas tratadas com as fra??es hexano e clorof?rmio obtidos da folha e tamb?m os extratos brutos obtidos dos frutos maduro e verde tiveram a??o antiviral, resultando na diminui??o total da carga viral. Finalmente, a partir desse estudo podemos identificar uma poss?vel atividade antiviral dos compostos obtidos de Morinda citrifolia contra o v?rus dengue. / Dengue is an arbovirosis which affects mankind, causing problems in the public health worldwide, especially in tropical countries which present conditions that favor the spread of the mosquito Aedes aegypti. Currently, among the various strategies to control the disease, there is no effective vaccine or antiviral capable of combating this infection. Thus, the aim of the present study was to evaluate the antiviral activity of leaf and fruit extracts of the plant Morinda citrifolia L. in Vero cells culture infected with dengue-2 virus (DENV-2). Initially, the crude extracts (hydroethanolic) and their fractions were obtained: hexane, chloroform and ethyl acetate, followed by chromatographic analysis. The cytotoxicity test of the crude extract, the aqueous residue and its fractions were performed in culture of Vero cells by the MTT method, at concentrations of 1000; 500; 250; 125; 62.5; 31.2 ?g/mL. The antiviral assay results were conducted through the following strategies: cells infected with DENV-2 (positive control); cells maintained with culture medium (negative control); cells infected with DENV-2 and treated with the extract or fractions. After five days of infection, cell viability was evaluated by the MTT method and culture supernatant was used for viral quantification by plaque forming unit (PFU) assay. The results showed that the chromatographic analysis of extracts and fractions present distinct bands, which could be suggestive of saponins, terpenes and flavonoids. Such extracts and fractions were not toxic to cell cultures, except for the cells treated with the chloroform fraction obtained from leaf, hexane and ethyl acetate fractions of the green fruit, leading to a near 65% viability. In the antiviral assay the positive control had 60% of cell viability after five days of infection. Among the leaf extract treatments, it was observed that infected cells treated with ethyl acetate fraction, maintained their cell viability around 100% in the concentration of 1000?g/mL and up to 85% in the concentrations of 500 and 250?g/mL. The hexane fraction treatment showed higher viability in comparison to the positive control at all concentrations. However, in the chloroform fraction, viability remained high only at concentrations of 500 and 250 ?g/mL. Crude extract and residual aqueous fraction did not show any antiviral activity. Cells treated with the extract and different fractions obtained from the mature and green fruits, presented an overall cell viability close to 100% in 500 and 1000 ?g/mL in the mature fruit and only 1000 ?g/mL in the green fruit. However, for the cells treated with the chloroform fraction, it was not possible to observe any significant difference when compared to the positive control. In the viral quantification it was observed that cells treated with hexane and chloroform fractions obtained from leaf, as well as crude extracts obtained from mature and green fruits had antiviral effect, resulting in a total viral load decrease. Finally, identified from this study, a possible antiviral activity of the compounds obtained from Morinda citrifolia against dengue virus.
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