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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

Rela??o do volume de ultrafiltra??o e sobrevida em pacientes incidentes em di?lise peritoneal

Marian, Maria Vianei 22 June 2012 (has links)
Made available in DSpace on 2015-04-14T13:35:34Z (GMT). No. of bitstreams: 1 439669.pdf: 2432426 bytes, checksum: 926062560772ee0fef9ad537b63bff41 (MD5) Previous issue date: 2012-06-22 / Introduction: Peritoneal dialysis ultrafiltration failure is a functional abnormality associated with increased risk of death and technique failure. Daily ultrafiltration volume early on therapy may predict patient and technique survival. Objective: to determine the relationship between to presence of risk factors, daily ultrafiltration volume, patient and technique survival. Patients and Method: Data were extracted from the observational, multicenter, BRAZPD cohort study. From a population of 2419 suitable patients, 977 incident patients were selected. At the three-month therapy interval, demographic, clinical and technical variables were appraised and daily ultrafiltration volume was analyzed by quartiles (1st: &#8804; 700 ml; 2nd: > 700 ml up to &#8804; 1100 ml; 3rd: > 1100 ml up to < 1600 ml; 4th: &#8805; 1600 ml), as were its changes at the sixth and twelfth follow-up months. Two outcomes were considered : death and technique failure, which were analyzed till the 30th therapy month. Comparison between groups, correlations, patient and technique uni and multivariate survival analyses, using Kaplan-Meier technique and Cox regression analysis, were performed. Results: Age (HR=1.038; 95% CI: 1.027-1.049; P<0.01), diabetes (HR=1.416; 95% CI: 1.043-1.922; P=0.03) and number of co-morbidities (HR=2.687; 95% CI: 1.336-5.407; P<0,01) were directly associated with increased patient mortality. The 4th ultrafiltration quartile related with higher patient and technique survival (P=0.02 and P=0.10, respectively); peritonitis had a strong negative effect upon therapy maintenance (HR=3.459; 95% CI: 2.218-5.394; P<0.01). Conclusion: young, non-diabetic patients had increased chance for survival. High ultrafiltration volumes promoted patient and technique survival. Peritonitis significantly reduced the likelihood of technical success. / Introdu??o: A falha de ultrafiltra??o na di?lise peritoneal ? uma anormalidade funcional associada a risco aumentado para morte e para falha t?cnica. O volume di?rio de ultrafiltra??o, aos tr?s meses de terapia, pode ser fator de risco e preditor precoce para sobrevida de paciente e t?cnica. Objetivo: determinar a rela??o entre a presen?a de fatores de risco, volume di?rio ultrafiltrado e sobrevida de paciente e terapia. Pacientes e M?todo: estudo de coorte baseado em dados do estudo BRAZPD, multic?ntrico, observacional. Foram inclu?dos 977 pacientes incidentes, dentre 2419 eleg?veis. Aos tr?s meses de terapia analisaram-se vari?veis demogr?ficas, cl?nicas e t?cnicas. O volume di?rio de ultrafiltra??o foi analisado por quartis, (1? quartil: &#8804; 700 ml; 2? quartil: > 700 ml e &#8804; 1100 ml; 3? quartil: > 1100 ml e < 1600 ml; 4? quartil: &#8805; 1600 ml, assim como sua varia??o aos seis e doze meses de seguimento. Dois desfechos foram contemplados: morte e falha t?cnica, analisados at? 30 meses de terapia. Compara??es entre grupos, correla??es bem como an?lise univariada de sobrevida - de paciente e t?cnica - foi feita pela t?cnica de Kaplan-Meier e multivariada por regress?o de Cox. Resultados: idade (HR=1,038; IC 95%: 1,027-1,049; P<0,001), Diabetes Mellitus (HR=1,416; IC 95%: 1,043-1,922; P<0,026) e n?mero de comorbidades (HR=2,687; IC 95% -1,336-5,407; P<0,01) foram diretamente associados com mortalidade aumentada do paciente. O quarto quartil de ultrafiltra??o associou-se a maior sobrevida do paciente e da t?cnica (P=0,02 e P=0,10, respectivamente); a ocorr?ncia de peritonite teve impacto negativo para manuten??o da terapia (HR=3,459; IC 95%: 2,218-5,394; P<0,01). Conclus?o: pacientes jovens, sem diabetes tiveram maior chance de sobrevida. Ter alto volume de ultrafiltra??o foi favor?vel ? sobrevida de pacientes e da t?cnica. A ocorr?ncia de peritonite reduziu significativamente a chance de sucesso da t?cnica.
2

Avalia??o do potencial antioxidante e antimicrobiano de prote?nas do soro de leite concentradas por membranas e hidrolisadas por diferentes enzimas comerciais / Evaluation of potential antioxidant and antimicrobial activities of whey proteins concentrated by membranes and hydrolyzed by different commercial enzymes

SOUZA, Renata Silva Cabral de 23 May 2013 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-29T17:12:51Z No. of bitstreams: 1 2013 - Renata Silva Cabral de Souza.pdf: 1753830 bytes, checksum: 2dff8752eb3f7974e34f8809d059f126 (MD5) / Made available in DSpace on 2018-11-29T17:12:51Z (GMT). No. of bitstreams: 1 2013 - Renata Silva Cabral de Souza.pdf: 1753830 bytes, checksum: 2dff8752eb3f7974e34f8809d059f126 (MD5) Previous issue date: 2013-05-23 / CAPES / The aim of this study was to evaluate the process of protein concentration in bovine whey proteins by ultrafiltration process and subsequently the protein hydrolysate obtained by enzymatic hydrolysis to produce bioactive peptides with potential antimicrobial and antioxidant activities. For concentration process was used a ceramic ultrafiltration membrane with a molecular range cut-off of 10-20 kDa, transmembrane pressure of 5 bar and, temperature of 30 ?C, 40 ?C and 50 ?C . The optimum temperature condition was at 40 ?C. The Volume Concentrate Factor (VCF) parameter was used as a end-point of the ultrafiltration process and fixed at 2, corresponding on concentrating the initial volume twice, in volume. At the temperature of 40 ?C, VCF had a correspondence on final protein concentration on the concentrated fraction by ultrafiltration and confirmed by Bradford method. Two commercial enzymes were tested Alcalase, Flavourzyme and an equivalent mixture of both 50:50 (w/w) in the hydrolysis reaction. The hydrolysis conditions were determined according to manufacturer instructions and confirmed by other studies: 60 ?C and pH 8 for Alcalase; 50 ?C and pH 7 for Flavourzyme; 50 ?C and pH 8 for enzyme mixture with enzyme / substrate ratio (w / w) 5/100 for all enzymes. The reaction was monitored by pH Stat method. The final Degree of Hydrolysis (DH) achieved was 15%, 52% and 63% for Flavourzyme, Alcalase and enzyme mixture, respectively. Five aliquots were collected along the hydrolysis for each enzyme reaction corresponding to differents DH in order to evaluatethe antioxidant activity by ORAC and ABTS assays with final values between 597- 1092 m? TE (ABTS) and from 1615 to 2920 ?M TE (ORAC) for Flavourzyme; 998-6290 ?M TE (ABTS) and 3092-7567 ?M TE ( ORAC) for Alcalase and finally 913-2678 ?M TE (ABTS) and 2547-5903 ?M TE (ORAC) for the enzyme mixture. The samples from all hydrolysates showed no antimicrobial activity against strains of Salmonella choleraesuis subsp. Enteritidis (ATCC 13076) and Listeria monocytogenes (ATCC 9117). / A proposta do presente trabalho foi avaliar a concentra??o das prote?nas do soro de leite bovino por ultrafiltra??o e posterior obten??o de hidrolisados proteicos deste concentrado via hidr?lise enzim?tica visando obter pept?deos bioativos com potencial atividade antimicrobiana e antioxidante. Para concentra??o das prote?nas do soro foi utilizada membrana cer?mica de ultrafiltra??o com massa molar de corte de 10-20 kDa, press?o aplicada ? membrana de 5 bar, temperaturas testadas (30 ?C, 40 ?C e 50 ?C) . A temperatura ?tima selecionada foi de 40 ?C. O Fator de Concentra??o Volum?trica foi o par?metro utilizado para indicar o final do processo de ultrafiltra??o sendo fixado em duas vezes o volume inicial da alimenta??o. Na temperatura de 40 ?C foi obtida correspond?ncia entre a concentra??o volum?trica e a concentra??o proteica final na fra??o retida pela UF, que tamb?m foi o dobro da encontrada na fra??o alimenta??o, avaliada pelo m?todo de Bradford. Foram testadas duas enzimas comerciais: Alcalase, Flavourzyme e uma mistura equivalente de ambas, na propor??o 50:50 (m/m) na rea??o de hidr?lise. As condi??es de rea??o enzim?tica foram determinadas de acordo com instru??es do fabricante e corroboradas por outros estudos em: 60 ?C, pH 8 para Alcalase; 50 ?C, pH 7 para Flavourzyme; 50 ?C, pH 8 para mistura enzim?tica e rela??o enzima/substrato (g/g) foi de 5/100 para todas as enzimas. A rea??o de hidr?lise foi monitorada pelo m?todo pH Stat. Os Graus de Hidr?lise (GH) finais alcan?ados foram de 15 %, 52 % e 63 % para Flavourzyme, mistura enzim?tica e Alcalase, respectivamente. Foram coletadas cinco al?quotas correspondentes a diferentes GH ao longo da rea??o para cada condi??o enzim?tica utilizada e avaliadas quanto a atividade antioxidante pelos m?todos ABTS e ORAC tendo valores entre 597 a 1092 ?M TE (ABTS) e 1615 a 2920 ?M TE (ORAC) para Flavourzyme, 998 a 6290 ?M TE (ABTS) e 3092 a 7567 ?M TE (ORAC) para Alcalase e por fim, 913 a 2678 ?M TE (ABTS) e 2547 a 5903 ?M TE (ORAC) para a mistura enzim?tica. Nenhuma das amostras de hidrolisado com diferentes GH apresentou atividade antimicrobiana contra cepas de Salmonella choleraesuis subsp. Enteritidis (ATCC 13076) e Listeria monocytogenes (ATCC 9117).
3

Produ??o, concentra??o e caracteriza??o parcial de extrato celulol?tico produzido por linhagem f?ngica mutante

Santos, Alex da Silva 28 February 2011 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-08-03T16:30:05Z No. of bitstreams: 1 2011 - Alex da Silva Santos.pdf: 1990293 bytes, checksum: b92b4e5aec031d9fcd17900f0f1ef9c8 (MD5) / Made available in DSpace on 2016-08-03T16:30:05Z (GMT). No. of bitstreams: 1 2011 - Alex da Silva Santos.pdf: 1990293 bytes, checksum: b92b4e5aec031d9fcd17900f0f1ef9c8 (MD5) Previous issue date: 2011-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior, CAPES / The production of enzymes for application at different areas of food agroindustry presents promising future perspectives, due to several intrinsic properties regarded to the performance of the enzymes as natural and biodegradable compounds, responsible for achieving specific reactions with better quality. Cellulases have been the most employed enzymes on food industry, acting sinergically on the hydrolysis of the glucosidic links ?-1,4 from the molecules of cellulose, and being used on several applications in this sector as in vegetal oils extraction, fruit maceration and juice clarification. Based on this context, the present study aimed to produce, concentrate and partially characterize an enzymatic extract by a mutant fungus strain of Aspergillus niger. Production was performed by solid-state fermentation (SSF) in aerated columns, using humidified wheat bran with (NH4)2SO4 solution on 0,1N HCl as substrate and cellobiose as inducer. Cellulolytic extract was a blend of extracts from three different assays selected on previous studies as the best conditions for the enzymes caboxymethilcellulase, ?-glucosidase and filter paper cellulose (FPase). During the characterization of the enzymatic extract, besides cellulases activity, the presence of protease and other enzymes with similar action to cellulases as xylanase and poligalacturonase was evaluated. For enzymatic extract concentration, three different strategies were performed: ultrafiltration, using a stainless steel plates system through a 20 kDa molecular weight cut-off polyethersulphone membrane and 0,014 m2 area; precipitation with ammonium sulphate under 20%, 40 %, 60% and 80% saturation level and lyophiilization. The best results were achieved by the ultrafiltration process, partially purified sample and providing enzymatic activities recovery between 75% and 99%, except for FPase. SDS-PAGE analysis presented 15 visible protein bands on cellulolytic extract with molecular weights ranging from 13.3 to 104.6 kDa. Zymography test was applied for cellulases and correlate enzymes as well as to protease, however, just for the last one the conditions were considered appropriate, identifying bands on 88, 103 and 145 kDa. The effective performance of ?-glucosidase and xylanase over xylan and cellobiose hydrolysis was confirmed by thin layer chromatography. A central rotational statistical design 22 with 4 central points was used for evaluating optimal temperature and pH for carboxymethylcellulase and ?-glucosidase. The analysis of the results obtained for both enzymes demonstrated that all variables were significative at a 95% confidence level. Based on the conditions studied it can be concluded that optimal pH and temperature ranges for efficient and combined action of carboxymethylcellulase and ?-glucosidase are 3.7 to 5.5 and 60 to 65?C, respectively. / A produ??o de enzimas para uso em diferentes ?reas da agroind?stria de alimentos mostra perspectivas futuras promissoras, devido ?s v?rias caracter?sticas inerentes ? a??o das enzimas que s?o compostos naturais, biodegrad?veis e capazes de desempenhar rea??es espec?ficas com melhor qualidade. Entre as enzimas mais utilizadas pelo setor de alimentos est?o as celulases, um complexo de enzimas que atuam de forma sin?rgica sobre a hidr?lise das liga??es glicos?dicas ?-1,4 das mol?culas de celulose, e possuem v?rias aplica??es industriais neste setor, como na extra??o de ?leos vegetais, na macera??o de frutas e na clarifica??o de sucos. Dentro deste contexto, este trabalho teve como objetivo produzir, concentrar e caracterizar parcialmente um extrato celulol?tico obtido por linhagem f?ngica mutante de Aspergillus niger. A produ??o foi realizada por fermenta??o no estado s?lido (FES) em colunas aeradas, utilizando como substrato farelo de trigo triturado umidificado com solu??o de (NH4)2SO4 em HCl 0,1N e celobiose, como indutor. O extrato celulol?tico consistiu de uma mistura de extratos obtidos em 3 ensaios fermentativos diferentes, selecionados em trabalhos anteriores como as melhores condi??es para produ??o de cada uma das enzimascarboximetilcelulase (CMCase), ?-glicosidase e celulase em papel de filtro (FPase). Durante a caracteriza??o do extrato enzim?tico, al?m da atividade das celulases, tamb?m era avaliado o teor de prote?na, a presen?a de protease e de enzimas correlatas ? a??o de celulases como xilanase e poligalacturonase. Para concentra??o do extrato enzim?tico foram realizadas tr?s diferentes estrat?gias: ultrafiltra??o em um sistema de quadro e placas em a?o inox, utilizando uma membrana de polietersulfona com massa molar de corte de 20 kDa e ?rea de 0,014m2; precipita??o com sulfato de am?nio utilizando satura??es de 20%, 40%, 50%, 60%, 80% e liofiliza??o. O processo de ultrafiltra??o foi o que obteve o melhor resultado, purificando parcialmente a amostra e proporcionando uma recupera??o das atividades enzim?ticas entre 75% e 99% para todas as atividades avaliadas, exceto FPase. A an?lise eletrofor?tica em SDS-PAGE demonstrou a presen?a de 15 bandas vis?veis de prote?nas no extrato celulol?tico com pesos moleculares que compreendem uma faixa entre 13,3 e 104,6 kD. O teste de zimografia foi realizado para as celulases e enzimas correlatas, bem como para protease, no entanto somente para esta ?ltima, as condi??es testadas foram adequadas tornando-se poss?vel identificar bandas em 88, 103 e 145 kDa. A efetiva a??o das enzimas ?-glicosidase e xilanase na hidr?lise de celobiose e xilana, respectivamente,foi comprovada em cromatografia de camada fina. Al?m disso, a temperatura e pH ?timos de atua??o de carboximetilcelulase e ?-glicosidase foram determinados utilizando o delineamento composto central rotacional 22, com 4 pontos centrais. A an?lise dos resultados de ambas as enzimas demonstrou que as vari?veis eram significativas, a um n?vel de confian?a de 95%. Com base nas condi??es estudadas, concluiu-se que as faixas de pH e temperatura ?timos para a atua??o eficiente e conjunta de CMCase e ?-glicosidase est?o entre 3,7 a 5,5 e 60 a 65 ?C, respectivamente.

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