Encontrados 47 documentos, a visualizar página 1 de 5
Treatment of persistent perineal sinus after abdominoperineal resection with gr...
Branco, Rui; Serviço de Cirurgia II Hospital Santa Maria – CHLN - PortugalIntroduction: After an abdomino-perineal resection of the rectum, infection of the perineal wound is a complication observed in 7-47% of cases. Its incidence increases when associated to inflammatory bowel disease. Persistent sinus is observed in 3-69% of cases. There are various etiological factors associated with this complication; preoperative radiotherapy is the most important. There are various techniques ...
Optimization and characterization of biosurfactant production by Bacillus subti...
Pereira, J. F.; Gudiña, Eduardo J.; Costa, Rita; Vitorino, Rui; Teixeira, J. A.; Coutinho, João A. P.; Rodrigues, L. R.Biosurfactant production by three Bacillus subtilis strains (#309, #311 and #573) isolated from Brazilian crude oils was optimized based on different carbon and nitrogen sources. The lowest surface tension values were obtained using sucrose containing media for the three isolates. Biosurfactants produced by each strain were characterized by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic...
Biosurfactant-producing and oil-degrading Bacillus subtilis strains enhance oil...
Gudiña, Eduardo J.; Pereira, J. F.; Costa, Rita; Coutinho, João A. P.; Teixeira, J. A.; Rodrigues, L. R.Microbial Enhanced Oil Recovery (MEOR) technology uses microorganisms and their metabolites to retrieve unrecoverable oil from mature reservoirs. In situ stimulation of biosurfactant-producing and oil-degrading microorganisms reduces the capillary forces retaining the oil inside the reservoir and decreases its viscosity, thus promoting oil flow and consequently production. In this work, a sand-pack column model...
A biosurfactant-producing and oil-degrading Bacillus subtilis strain enhances o...
Gudiña, Eduardo J.; Pereira, J. F.; Costa, Rita; Rodrigues, L. R.; Coutinho, João A. P.; Teixeira, J. A.Microbial Enhanced Oil Recovery (MEOR) is potentially useful to increment oil recovery from reservoirs beyond primary and secondary recovery operations using microorganisms and their metabolites. In situ stimulation of microorganisms that produce biosurfactants and degrade heavy oil fractions reduces the capillary forces that retain the oil inside the reservoir and decreases oil viscosity, thus promoting its fl...
Evaluation and characterization of biosurfactants produced by microorganisms is...
Pereira, J. F.; Gudiña, Eduardo J.; Costa, Rita; Rodrigues, L. R.; Teixeira, J. A.; Coutinho, João A. P.Surface-active agents or surfactants are amphiphilic molecules that comprise both hydrophilic and hydrophobic moieties, allowing the reduction of the surface and interfacial tensions, as well as the formation of oil in water or water in oil emulsions. Due to their interesting properties, surfactants are widely used by petroleum industries to reduce the capillary forces that retain the oil inside the reservoir. ...
Medições do teor de oxigénio em diferentes fases da produção de vinhos
Coutinho, João Falcato DiasMestrado em Viticultura e Enologia - Instituto Superior de Agronomia / Faculdade de Ciências. Universidade do Porto ; Due to the major interest in oxygen-wine interaction by winemakers, it seemed of the most utility to monitorize the contents of dissolved oxygen since the fermentation till the bottling in both white and red wines. The aim was to identify which processes were responsible for the greatest incorp...
Solubility of hesperetin in mixed solvents
Ferreira, Olga; Schröder, Bernd; Coutinho, João A.P.The study of the solubility of flavonoids is essential to support the design of several separation processes in the food and pharmaceutical industries. Hesperetin is a flavanone with great importance for its promising biological and pharmacological properties. Our previous studies included the measurement of the solubility of this biomolecule in several pure organic solvents [1]. In this work, new solubility da...
Supported ionic liquid silica nanoparticles (SILnPs) as an efficient and recycl...
Sidhpuria, Kalpesh B.; Daniel-da-Silva, Ana L.; Trindade, Tito; Coutinho, João A. P.Supported ionic liquid nanoparticles (SILnPs) having particle size ranging from 293 ± 2 to 610 ± 11 nm have been prepared by immobilization of ionic liquid, 1-(tri-ethoxy silyl-propyl)- 3-methyl-imidazolium hydrogen sulfate (IL-HSO4) on the surface of silica nanoparticles. The catalytic activity of the prepared SILnPs was investigated for the dehydration of fructose to 5-hydroxymethylfurfural (HMF) in the prese...
Extraction of vanillin using ionic-liquid-based aqueous two-phase systems
Cláudio, Ana Filipa M.; Freire, Mara G.; Freire, Carmen S.R.; Silvestre, Armando J.D.; Coutinho, João A.P.To explore proper extractive solvents and to design an optimized separation process it is highly imperative to understand the molecular-based phenomena governing the solutes partitioning. Moreover, the development of new techniques for the biomolecules separation and purification, while maintaining their functional characteristics unchanged, is still ongoing. Therefore, in this work, the partition coefficients ...
Isolation and study of microorganisms from oil samples for application in Micro...
Gudiña, Eduardo J.; Pereira, Jorge F. Brandão; Rodrigues, L. R.; Coutinho, João A. P.; Teixeira, J. A."Author's personal copy" ; Microbial Enhanced Oil Recovery (MEOR) is potentially useful to increment oil recovery from a reservoir beyond primary and secondary recovery operations using microorganisms and their metabolites. Stimulation of bacterial growth for biosurfactant production and degradation of heavy oil fractions by indigenous microorganisms can enhance the fluidity and reduce the capillary forces tha...
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