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Purificação de ficocianina de Spirulina platensis através de sistema aquoso bifásico e caracterização cinética da desnaturação térmicaAntelo, Francine da Silva January 2007 (has links)
Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia e Ciência de Alimentos, Escola de Química e Alimentos, 2007. / Submitted by Caroline Silva (krol_bilhar@hotmail.com) on 2012-09-25T18:50:40Z
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Previous issue date: 2007 / A microalga Spirulina platensis apresenta em sua biomassa compostos de alto valor
agregado como a ficocianina, um pigmento azul usado como corante natural na indústria
alimentícia e de cosméticos e de grande interesse na indústria farmacêutica devido as suas propriedades terapêuticas, fatos estes que tornam sua obtenção com alto grau de pureza e sua caracterização uma possibilidade atraente. A presente dissertação teve como objetivos estudar e otimizar o processo de purificação do extrato aquoso de ficocianina de Spirulina platensi, com e sem células, por Sistema Aquoso Bifásico (SAB) polietilenoglicol (PEG)/fosfato de potássio variando-se a massa molar do polímero, 1500, 4000, 6000 ou 8000 Da, assim como estudar a cinética de desnaturação térmica do extrato aquoso de ficocianina, avaliando sua estabilidade entre 50 e 65°C para valores de pH entre 5 e 7 e estabelecer o modelo cinético para cada uma das situações propostas. Verificou-se que o pH 6 proporcionou a melhor purificação da ficocianina que se concentrou na fase de topo, rico em PEG, em todos sistemas estudados. A análise de efeitos, realizada através de quatro planejamentos fatoriais completos (22 ensaios + 3 pontos centrais), evidenciou que o aumento do percentual de sal causou um incremento no fator de purificação e o inverso ocorreu para o percentual de PEG. A otimização do processo de purificação através de quatro planejamentos fatoriais completos tipo delineamento central composto rotacional (DCCR) (22 ensaios + 4 pontos axiais + 3 pontos centrais) estabeleceu que os SABs compostos por PEG 1500 e 8000 e fosfato de potássio, com 7 e 23% e 4 e 22,5%,
respectivamente, atingiram fatores de purificação máximos de 1,6 vezes para a ficocianina, com recuperação total da proteína no primeiro e de 57% no segundo e que os formados pelos PEG 4000 e 6000, compostos ambos por 4% de polímero e 21% de sal, alcançaram fatores de purificação de 2,1 e 2,2 vezes, recuperando 100 e 73,5% da proteína-alvo. A extração e a purificação da ficocianina em SAB polietilenoglicol/fosfato de potássio pH 6 integrando essas duas etapas, composto pelo PEG 1500 alcançou valores de pureza para a ficocianina superiores aos obtidos com o sistema convencional, em todos os percentuais
estudados, enquanto que para o PEG 6000, as purezas da proteína alcançadas nos ensaios
do sistema convencional foram todas superiores às obtidas no outro. Os sistemas
integrados compostos por 15% de PEG 1500 e 13% de fosfato de potássio e 5% de PEG
4000 e 18% de sal, alcançaram, nessa ordem, 0,73 e 0,79 de pureza (A620/A280), valores
estes que classificam esta ficobiliproteína como de grau alimentar, superior a 0,7. As
concentrações de ficocianina obtidas nas fases de topo desses dois sistemas
respectivamente, 2,67 e 1,60 mg.mL-1, evidenciam que o sistema composto pelo PEG 4000 foi mais eficiente que os demais pois alcançou a maior pureza conjugada a maior
concentração da proteína. Para a caracterização cinética da desnaturação térmica da ficocianina, o modelo foi assumido como de primeira ordem e entre 50 e 55°C, o extrato aquoso de ficocianina foi mais estável a pH 6 e entre 57 e 65°C em pH 5, sendo então, na faixa de temperaturas estudadas, mais instável a pH 7. As energias de ativação para os extratos de ficocianina foram de 87,36, 135,57 e 111,14 kcal/gmol, para os valores de pH 5, 6 e 7. A adição do agente estabilizante sorbitol, entre 10 e 50% ampliou o tempo de meiavida, provando que a descoloração da ficocianina é relacionada com a desnaturação da cadeia protéica e, através de testes estatísticos de diferença de médias, pode-se definir que ao final de 40 minutos de tratamento térmico, o extrato de ficocianina de pH 5 manteve cerca de 80% de sua concentração média relativa com adição de 30% (p/p) de sorbitol, para o pH 6, com 40% (p/p) de agente estabilizante, a concentração foi mantida em cerca de 86% e para o pH 7, a partir de 10 minutos, todas as concentrações de sorbitol adicionadas ocasionaram concentrações médias relativas de ficocianina diferentes significativamente e com 50% (p/p) de sorbitol 85% da concentração da proteína se manteve. / Spirulina platensis microalgae presents in its biomass high added value compounds like
phycocyanin, a blue pigment used as a natural colorant in the food and cosmetic industry
also of great interest in the pharmaceutical industry due to its therapeutic properties. These facts make obtaining it with a high purity level and its characterization an attractive possibility. The present paper aimed at studying and optimizing the purification process of the phycocyanin aqueous extract from Spirulina platensis with and without cells through aqueous two-phase systems (ATPS) polietilenoglicol (PEG)/potassium phosphate by varying
the polymer molar mass, 1500, 4000, 6000 or 8000 Da, as well as studying the thermal
denaturization kinetics of the phycocyanin aqueous extract by evaluating its stability between 50 and 65°C for pH values between 5 and 7 and establishing the kinetic model for each proposed situation. It was verified that the pH 6 provided the best phycocyanin purification which was concentrated in the top phase in all the studied systems. The effect analysis done for the four full factorial designs (22 trial plus + 3 central points), made clear that the increase of the salt percentage caused an increment in the purification factor and the inverse occurred
for the PEG percentage. The optimization of the purification process through four full factorial design CCRD (22 trial + 4 axial points + 3 central points) established that the ATPS composed by PEG 1500 and 8000 and potassium phosphate, with 7 and 23% and 4 and
22.5%, respectively, reached maximum purification factors of 1.6 fold for the phycocyanin, with total protein recovery in the first and 57% in the second and that the ones formed by PEG 4000 and 6000, both composed by 4% of polymer and 21% of salt, reached purification factor of 2.1 and 2.2 fold, recuperating 100 and 73.5% of the target protein. The phycocyanin extraction and purification in SAB polyethylene glycol/potassium phosphate pH 6, integrating
these two phases, composed by PEG 1500, reached purity values for phycocyanin higher
than the ones obtained with the conventional system in all studied percentages, while for
PEG 6000, all protein purities obtained in the conventional system trials were higher than the ones obtained in the other. The integrated systems composed by 15% of PEG 1500 and 13% of potassium phosphate and 5% of PEG 4000 and 18% of salt, reached, in this order, 0.73 and 0.79 of purity (A620/A280). These values classify this phycobiliprotein as of food grade, higher than 0.7. The concentrations of phycocyanin obtained in the top phases of these two systems, respectively, 2.67 and 1.6 mg.mL-1, make clear that the system composed by PEG 4000 was more efficient than the others because it reached the biggest purity along with to the highest protein concentration. For the kinetic characterization of the phycocyanin thermal denaturization, the model was assumed as of first order and, between 50 and 55°C, the phycocyanin aqueous extract was more stable at pH 6 and between 57 and 65°C at pH 5, thus, being more stable at pH 7 for the ranges of temperature studied. The activation energy for the phycocyanin extracts were 87.36, 135.57 and 111.14 Kcal/gmol for
pH 5, 6 and 7 values. The addition of the sorbitol stabilizing agent between 10 and 50%
increased the half-life, proving that the phycocyanin discoloration is related to the
denaturization of the protein chain and, through statistical tests of average differences, it is possible to define that, at the end of 40 minutes of thermal treatment, the pH 5 phycocyanin extract kept about 80% of its relative average concentration with the addition of 30% (w/w)
of sorbitol, for pH 7, with 40% (w/w) of stabilizing agent, the concentration was kept at about 86% and for pH 7, from 10 minutes on, all the sorbitol concentrations added caused significantly different phycocyanin relative average concentrations and with 50% (w/w) of sorbitol, 85% of the protein concentration was kept.
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Desenvolvimento de um método para obtenção da eficiência de detecção para detectores HPGe em medidas com fontes extensas / Development of a method for obtaining the efficiency of deterction in HPGe detector with measures large sourcesSANTOS, ROBERTO M. dos 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:48Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:27Z (GMT). No. of bitstreams: 0 / Um dos grandes desafios em medidas de espectrometria gama utilizando fontes que não podem ser consideradas pontuais é a determinação da eficiência de detecção do sistema, uma vez que a geometria da fonte impõe complexidades na tarefa como o tratamento do ângulo sólido e da auto-absorção. Alguns métodos para o cálculo dessa eficiência já são bem estabelecidos e podem ser encontrados na literatura. Neste trabalho é proposto um método com características distintas aos já existentes cujas principais vantagens são, não depender de conhecimento prévio da geometria de detecção e da composição química da amostra a ser medida, e permitir o cálculo da eficiência de uma fonte extensa a partir de medidas com fontes padrão em formato pontual. O método proposto foi testado comparando os valores das eficiências obtidas por ele com os valores obtidos usando uma fonte padrão extensa. Para testar o método proposto em diferentes condições foi utilizado solo como matriz para a amostra em duas diferentes espessuras, 1cm e 3cm. Testou-se também o comportamento do método quando a matriz tem número atômico efetivo mais alto (aqui utilizou-se solo misturado à limalha de ferro) e mais baixo (adição de pó de grafite ao solo). Os resultados indicaram que o método é adequado para amostras de solo com espessura mais fina; já para fontes mais espessas, dois dos três resultados indicaram que a eficiência foi subestimada pelo método proposto, sugerindo que uma geometria mais adequada deva ser escolhida para a amostragem das medidas / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Determinacao de parametros nucleares do nucleo de sup(127)Te: uma proposta para o ensino de fisica nuclear / Nuclear parameters determination of the sup(127)Te 'beta'sup(-) decay: a proposal for teaching nuclear fhysicsBATISTA, WAGNER F. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:33:08Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:21Z (GMT). No. of bitstreams: 0 / Um estudo do decaimento β- do 127Te, via espectroscopia gama, foi realizado utilizando um detector de HPGe de alta resolução. As medidas foram realizadas na região de energia de 30 keV a 1,0 MeV, com o objetivo de obter uma melhor compreensão de sua estrutura nuclear. As fontes radioativas de 127Te foram obtidas a partir da reação nuclear 126Te(n,γ)127Te, produzidas no reator IEA-R1 do IPEN/CNEN-SP. Cinco transições anteriormente atribuídas a este decaimento foram confirmadas com melhor precisão. Foi realizada também a medida da meia-vida do 127Te com incerteza significativamente menor. Utilizando um conjunto dos dados experimentais, selecionados da medida de espectroscopia gama, foi elaborada e aplicada uma proposta didática para alunos do Ensino Médio utilizando o programa Excel. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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FATE OF MICRO-ORGANIC POLLUTANTS ON THE RECOVERY OF PHOSPHORUS FROM URINE / 尿からリンを回収するプロセスにおける微量汚染物質の挙動解明PATIYA KEMACHEEVAKUL 26 September 2011 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16386号 / 工博第3467号 / 新制||工||1524(附属図書館) / 29017 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 清水 芳久, 教授 田中 宏明, 教授 藤井 滋穂 / 学位規則第4条第1項該当
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Discriminação Varietal de cultivares em Urochloa brizantha por marcador molecular ISSR / Varietal discrimination of cultivars Urochloa brizantha by ISSR molecular markersBraga, Inaê 08 August 2013 (has links)
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Previous issue date: 2013-08-08 / Approximately 80-90% of grassland areas in Brazil consist of the forage Urochloa, genus and the apomictic species Urochloa brizantha [syn. Brachiaria brizantha (Hochst. ex A. Rich.) Stapf.] the most used. Some genotypes of Urochloa have being widely used with a wrong nomenclature, even for species as for cultivars. In this way, the Urochloa cultivar identification is primordial for breeding programs and seed production. Considering the importance of genetic purity in comercialized seed lots, the present study aimed to investigate the potential of ISSR markers for discrimination of U. brizantha (Xaraés; Piatã, Basilisk; MG4; MG5; Marandú) in order to determine the degree of contamination of seed lots. ISSR markers showed a low degree of polymorphism . However, results showed it is possible to identify cultivars in pure samples of seeds Urochloa, requiring only ten primers. The cultivar Basilisk was confirmed as U. brizantha cultivar. It was not possible to differentiate samples intentionally contaminated at levels stipulated in the work. Further studies with other primers and other contamination levels will be important to detect varietal mixtures in cultivars U. brizanhta. / Aproximadamente 80 a 90% das áreas de pastagens no Brasil são constituídas por forrageiras do gênero Urochloa, sendo a espécie apomítica Urochloa brizantha [syn. Brachiaria brizantha (Hochst. ex A. Rich.) Stapf.] a mais utilizada. Alguns genótipos de Urochloa têm sido amplamente distribuídos com a nomenclatura equivocada, tanto para espécies como para cultivares. A identificação dos cultivares de Urochloa é fundamental para os programas de melhoramento e produção de sementes. Considerando a importância da pureza varietal em lotes de sementes comercializadas, o presente trabalho teve o objetivo verificar o potencial dos marcadores ISSR para a discriminação de U. brizantha (Xaraés; Piatã, Basilisk; MG4; MG5; Marandú) com a finalidade de determinar o grau de contaminação de lotes de sementes. Os marcadores ISSR apresentaram um baixo grau de polimorfismo. Todavia, os resultados mostraram ser possível identificar os cultivares em amostras puras de sementes de Urochloa, sendo necessários somente dez primers. O cultivar Basilisk foi confirmado como U. brizantha. Não foi possível diferenciar amostras contaminadas propositalmente nos níveis estipulados no trabalho. Novos estudos com outros primers e outros níveis de contaminação serão importantes para detectar misturas varietais em cultivares de U.brizantha.
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Discriminação Varietal de cultivares em Urochloa brizantha por marcador molecular ISSR / Varietal discrimination of cultivars Urochloa brizantha by ISSR molecular markersBraga, Inaê 08 August 2013 (has links)
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Previous issue date: 2013-08-08 / Approximately 80-90% of grassland areas in Brazil consist of the forage Urochloa, genus and the apomictic species Urochloa brizantha [syn. Brachiaria brizantha (Hochst. ex A. Rich.) Stapf.] the most used. Some genotypes of Urochloa have being widely used with a wrong nomenclature, even for species as for cultivars. In this way, the Urochloa cultivar identification is primordial for breeding programs and seed production. Considering the importance of genetic purity in comercialized seed lots, the present study aimed to investigate the potential of ISSR markers for discrimination of U. brizantha (Xaraés; Piatã, Basilisk; MG4; MG5; Marandú) in order to determine the degree of contamination of seed lots. ISSR markers showed a low degree of polymorphism . However, results showed it is possible to identify cultivars in pure samples of seeds Urochloa, requiring only ten primers. The cultivar Basilisk was confirmed as U. brizantha cultivar. It was not possible to differentiate samples intentionally contaminated at levels stipulated in the work. Further studies with other primers and other contamination levels will be important to detect varietal mixtures in cultivars U. brizanhta. / Aproximadamente 80 a 90% das áreas de pastagens no Brasil são constituídas por forrageiras do gênero Urochloa, sendo a espécie apomítica Urochloa brizantha [syn. Brachiaria brizantha (Hochst. ex A. Rich.) Stapf.] a mais utilizada. Alguns genótipos de Urochloa têm sido amplamente distribuídos com a nomenclatura equivocada, tanto para espécies como para cultivares. A identificação dos cultivares de Urochloa é fundamental para os programas de melhoramento e produção de sementes. Considerando a importância da pureza varietal em lotes de sementes comercializadas, o presente trabalho teve o objetivo verificar o potencial dos marcadores ISSR para a discriminação de U. brizantha (Xaraés; Piatã, Basilisk; MG4; MG5; Marandú) com a finalidade de determinar o grau de contaminação de lotes de sementes. Os marcadores ISSR apresentaram um baixo grau de polimorfismo. Todavia, os resultados mostraram ser possível identificar os cultivares em amostras puras de sementes de Urochloa, sendo necessários somente dez primers. O cultivar Basilisk foi confirmado como U. brizantha. Não foi possível diferenciar amostras contaminadas propositalmente nos níveis estipulados no trabalho. Novos estudos com outros primers e outros níveis de contaminação serão importantes para detectar misturas varietais em cultivares de U.brizantha.
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Torah-Observant Jewish Married Couples: The Influence of Mandated Abstinence of Physical Touch and Marital MaintenanceJanuary 2020 (has links)
abstract: Maintaining sexual desire as the marriage endures is a challenge, especially as it involves the interplay of seemingly opposing tensions of novelty, autonomy, and closeness. Difficulties can arise when autonomy, which requires spousal distancing, is perceived as a martial threat and therefore suppressed. This dissertation investigates whether prosocial marital distancing can nurture autonomy and promote sexual desire.
Torah-observant Jewish married couples practice family purity, a Jewish law forbidding sexual relations during menstruation and shortly thereafter. During this time couples often avoid sleeping in the same bed, physical touch, and behaviors that can instigate a sexual encounter. These distancing restrictions are lifted when the wife immerses in a ritual bath. The process repeats at the next menstruation.
This research examined the effects of family purity’s marital distancing through two studies. The first involved qualitative interviews of family purity wives (N = 10) guided by relational dialectics theory (Baxter & Montgomery, 1996). Study one findings suggest that family purity wives navigate the three tensions of integration, expression, and certainty. Study one also revealed a new tension, the dialect of restraint. The dialectic of restraint appears to enhance marital communication, heighten the appreciation for the mundane, and help sustain sexual desire.
Study two, the quantitative phase of the research, applied self-expansion theory (Aron & Aron, 1986) to investigate differences between family purity and non-family purity couples. A sample of 90 married Jewish dyads (N = 180) participated in a cross-sectional online questionnaire. Findings suggest that while non-practicing couples report greater self-expansion, family purity couples report greater sexual closeness. Family purity couples also report the same closeness and sexual closeness ideals, whereas non-practicing couples reported divergent ideals. Non-practicing family purity husbands had the greatest reported discrepancy between ideal and actual sexual closeness.
The combined findings suggest that sanctioned prosocial distancing as practiced by family purity couples enables the integration of cognitive growth and mitigates the threat of autonomy. Prosocial distancing within the family purity marriage appears to provide the wife space for autonomy that in turn provokes novelty and sexual desire. Findings are discussed in relation to theoretical contributions, study limitations, and future directions. / Dissertation/Thesis / Doctoral Dissertation Communication Studies 2020
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Čistota a nebezpečí: pohled na dodržování rituální čistoty v současné romské domácnosti / Purity and Danger: A View to Maintanance of the Ritual Purity in the Contemporary Roma HouseholdKadeřávková, Iva January 2020 (has links)
The diploma thesis: "Purity and Danger: The Perspective of Compliance with Ritual Purity in the Contemporary Roma House" deals with the boundary definitions of Roma groups and identities. This examination takes place via the narration of the Roma themselves and by observing the ritual practices in Roma households. The main tool that the Roma use in determining their group boundaries is the concept of cleanliness and impurity. It appears both in their narratives and in their ritual practice. This thesis describes the definition of a specific group of Roma women against many other groups of Roma and against the majority society. By doing so, we can examine their values, and the importance of the concept of purity in their lives and at the same time where their concept of purity comes from and how they work with it every day. Furthermore, it describes the environment, habits and clothes worn by women and their children, their hobbies and the way of their everyday life. Another important topic emerging at work is what roles men and women have in their group, and how the duties, or the spaces associated with their daily lives, are shared between the sexes. In conclusion, the thesis also answers the questions of what role the concept of purity plays in the life of particular studied families, how this...
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Effects of Religious Returnees' Observance of Family Purity Laws on Marital Satisfaction ScoresShtrambrand, Tamar Eva 01 January 2018 (has links)
Baal teshuvas are traditionally observant Orthodox Jewish individuals who were previously not religiously observant and chose to become observant at a later juncture in their lives. This population is at risk of psychosocial dysfunction, particularly in the area of marriage, but little or no research has been conducted with this population. The purpose of this study was to study how 1 factor, the laws of family purity, an ancient set of Jewish laws governing sexual behavior between husbands and wives, may have an effect on marital satisfaction among baal teshuvas. Areas of marital satisfaction were measured by the Revised Dyadic Adjustment Scale, Triangular Love Scale, and New Sexual Satisfaction Survey. Relational-cultural theory and relational spirituality were used to describe how spirituality affects individual well-being and the quality of one's relationships with others. A sample of 44 male and 59 female baal teshuvas completed the surveys. MANOVAs and 2-factor ANOVAs were conducted to compare the effects of gender and level of observance of family purity laws on marital satisfaction survey results. Results indicated a significant difference only by gender on the sexual satisfaction measure, although it is not known how much of a difference there was between the genders. This study reinforces indications from past research that studying sexual satisfaction in marriages is an increasingly important area of study and clinical practice. This study may lead to positive social change by identifying methods to improve marital satisfaction in the newly religious population. In addition, the results may provide further evidence supporting the already known positive psychological benefits of the laws of family purity.
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Perceptions of Purity Messaging on Women and Secular SocietyHurd, Madison 05 1900 (has links)
Purity culture was a movement created by evangelical Christian organizations in the United States and backed by marketing campaigns, media, churches, and sex education beginning in the 1990s. This movement was founded on the idea that young men and women should remain abstinent before marriage, thereby remaining in a state of "purity" for their future spouse. In purity culture messaging, women were positioned as sexual gatekeepers while men were framed as having little or no control over their sexual impulses, causing most of the purity expectation to fall on women. While the concept of remaining "pure" is not new, purity culture taught a new generation of women to feel ashamed and fearful of their sexuality and existed alongside an increasingly sexualized media landscape. This study analyzes purity culture and anti-purity culture themes that exist within television shows as well as how women perceive purity culture messaging and the effects this messaging had on their lives.
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