Otimização da extração de azeite de azeitona ‘Cobrançosa’ por adição de adjuvantes tecnológicos

Realizaram-se ensaios de modelação e otimização das condições operatórias de extração de azeite, utilizando a metodologia das superfícies de resposta, segundo uma matriz central compósita rotativa, em função da concentração adicionada de adjuvantes na termobatedura – preparação enzimática Endozym Olea AS (0,04-0,24%) e microtalco FC8 (0,12-0,68%) – a um lote de azeitona Cobrançosa com um índice de maturação de 3,05. Os ensaios de extração foram efetuados em equipamento Abencor, calculando o rendimento pelo índice de extratabilidade e o teor de gordura dos bagaços. Os resultados obtidos mostram que o rendimento da extração depende do teor de talco, mas é independente da concentração de enzima adicionada, nos valores testados. Nem os pigmentos clorofilinos nem os critérios de qualidade do azeite foram afetados pela presença de adjuvantes

Modelling the production of ethyl butyrate catalysed by Candida rugosa lipase immobilised in polyuretane foams

Response surface methodology was used to model and optimise the esterification of ethanol with butyric acid in n-hexane, catalysed by Candida rugosa lipase immobilised in two hydrophilic polyurethane foams (“FHP 2002TM” and “FHP 5000TM”). Experiments were carried out following central composite rotatable designs (CCRD), as a function of the initial water activity of the biocatalyst (aw), initial butyric acid concentration (A) and ethanol:acid molar ratio (MR) in the organic medium. Ester production increased with increasing aw of the biocatalysts, probably due to the hydrophilicity of both substrates in contrast with the hydrophobicity of the product, which is released to the bulk medium. Thus, for each biocatalyst (aw = 0.98) another CCRD was performed as a function of A and MR. With both preparations, higher conversions (>95%) were observed for low A values. For the “FHP 2002TM” system, a maximum ester production of 0.23M is expected, after 18-h reaction, at initial 0.35M A and 1.51 MR, corresponding to aw of 0.95 and 0.84MA and 1.65Methanol in lipase microenvironment.With “FHP 5000TM” system, predicted initial conditions of 0.54M A and 0.75 MR (0.32M A; 0.75M ethanol in microenvironment; aw of 0.95), will lead to the maximum ester production of 0.27 M. These maxima were experimentally confirme

Sulfite Oxidase Deficiency – An Unusual Late and Mild Presentation

Introduction: Sulfite oxidase deficiency (SOD) is an autosomal recessive inherited disease usually presenting in the neonatal period with severe neurological symptoms including seizures, often refractory to anticonvulsant therapy, and a rapidly progressive encephalopathy resembling neonatal hypoxic ischemia, with premature death. Most patients develop dislocated ocular lenses. Later or milder presentations of SOD are being reported with increasing frequency. These presentations include neurological regression with loss of previously acquired milestones or movement disorders. Case report: We report a four years old girl presenting with intermittent ataxia and uncoordinated limb movements. A similar episode of ataxia had occurred previously, one year before, with complete neurologic recovery and normal developmental milestones. Bilateral lens dislocation had been recently diagnosed. Cranial MRI demonstrated bilateral globus pallidus enhancement. Low homocysteine was found in plasma and SulfitestR was positive. Further investigations led to confirmation of isolated sulfite oxidase deficiency with no enzyme activity detected on skin fibroblasts culture. Discussion: This case illustrates the clinical variability of SOD and it is not only atypical but also seems to be the mildest form described so far. The association of ectopia lentis with a movement disorder, even without psychomotor regression, should prompt us to look for this diagnosis

A response surface methodology study on the role of factors affecting growth and volatile phenol production by Brettanomyces bruxellensis ISA 2211 in wine

The present study was aimed at determining the effect of glucose, ethanol and sulphur dioxide on the growth and volatile phenol production by Brettanomyces bruxellensis in red wines using a response surface methodology approach. Sulphur dioxide proved to have a significant (p < 0.05) negative linear and quadratic effect on growth and 4-ethylphenol production. Concentrations of sulphur dioxide higher than 20 mg L 1, at pH 3.50, induced immediate loss of cell culturability under growth permissive levels of ethanol. Under high ethanol concentrations (14% v/v), the lag phase increased from 3 to 10 days, growth being fully arrested at 15% (v/v). Glucose up to 10 g L 1 was found to be a significant factor (quadratic level) in biomass increase under low ethanol (<12.5% v/v) and low sulphite concentrations. However, when cells were inactivated by sulphur dioxide and ethanol, glucose (up to 10 g L 1) did not prevent cell death. Production of more than 50 mg L 1 day 1 of 4-ethylphenol was only observed in the presence of high numbers (106 CFU mL 1) of culturable cells, being stimulated by increasing glucose concentrations.info:eu-repo/semantics/publishedVersio

Shelf-Ocean material exchange influencing the Atlantic chemical composition off NW Iberian margin since the last glaciation

Rivers are the main conduit of sediment to the shelf. The basin geology, the drainage area and the discharge rate are the major factors that determine their sediment load (Milliman and Syvistski, 1992). Besides suspended particles, dissolved components may also give some information on the eroded crust. Sr isotopes in carbonate shells of biological organisms have been used to study, in the geological record, the influence exerted by the chemical weathering of the continental crust on the seawater composition (Macdougall, 1991). In this work, Sr isotope ratios obtained in tests of foraminifera representing the last 40 ka are presented and discussed in the scope of the palaeogeographical evolution of NW Iberia. This work aims to present and discuss the results of Sr isotope analyses (performed, by TIMS, in the Isotope Geology Laboratory of the University of Aveiro) of tests of two species of foraminifera, from nine samples taken along the OMEX core KC 024-19 (181 cm; 42°08’98’’N, 10°29´96’’W, and 2765m), collected in the Galicia Bank area, off Galicia. Taking into account that Sr contained in the carbonate tests is usually considered as preserving the signature of the contemporaneous seawater, one planktonic species (Globigerina bulloides) and one benthic species (Cibicides wuellerstorfi) were selected in order to try to detect Sr isotope variations both through time and between two different levels of the water column. The core age model, which records the last 40 ka, is based on a combination of oxygen isotope stratigraphy, eight AMS 14C datings and the synchronisation of the last four Heinrich Events in the Iberian Margin sedimentary records. As a whole, the obtained 87Sr/86Sr ratios vary between 0.709209 and 0.709108, with a mean 2σ error of 0.000025. These values lie within the range of modern marine Sr isotope ratios (0.70910-0.70922), as previously defined using analyses of both seawater and marine carbonates (see compilation by Faure and Mensing, 2005). Despite their small variation, the 87Sr/86Sr ratios obtained in G. bulloides seem to indicate that Sr dissolved in seawater at the KC 024-19 core site became slightly less radiogenic after the Last Glacial Maximum (LGM). This decrease is concomitant with diminishing amounts of the detrital components in the sediments (Fig. 1). Therefore, both the composition of dissolved Sr, as revealed by results on tests of planktonic foraminifera, and the proportions of suspended terrigenous particulate material arriving at the KC 024-19 site point to a decreasing importance of the contribution of the erosion of the Iberian Variscan crust since the Last Glacial Maximum and in the Holocene. The 87Sr/86Sr ratios measured in tests of benthic foraminifera (C. wuellerstorfi) are more erratic and no correlation can be established with palaeogeographical/palaeoclimatic constraints. The difference between the behaviour of Sr compositions in G. bulloides and C. wuellerstorfi may indicate that whilst the planktonic foraminifera should reproduce very closely the seawater composition, the benthic organisms should, in addition to the major role of seawater, also be affected by some sort of interaction with the sediments. As such, planktonic foraminifera are probably more reliable indicators of seawater composition in studies involving very small periods and corresponding very slight variations of the 87Sr/86Sr ratios. Taking into account that G. bulloides is a common planktonic species (living mostly in the first 50m of the water column), whose tests seem to be in equilibrium with sea water composition, variations in its 87Sr/86Sr ratios can be related with changes in the chemical composition of the water of the Atlantic Ocean off NW Iberian Margin. The highest 87Sr/86Sr values are contemporaneous with a period of low sea level (about -140 m; Dias et al., 2000) during the LGM. According to Dias et al. (2000) at 18 ka BP the shoreline was close to the shelf break. The summital parts of the Gerês and Estrela mountains were covered by local glaciers and close to the coast freezing occurred frequently. The river catchments, which extended far to the shelf, received more rainfall due to a longer, compared to present day conditions, wet season, which promoted both physical and chemical weathering. Higher pluviosity combined with the effect of spring ice melting maintained high river discharge and consequently caused very important sediment supply to the coastal zone. The extremely narrow shelf was a very energetic environment due to sea bottom inclination and very limited long wave refraction. Therefore, at that time, a long wet season and very competent rivers should have caused important erosion of the Variscan basement in NW Iberia. Additionally, then, the shoreline was much closer to the KC 024-19 site. The combination of all these factors favoured an important deposition of terrigenous sediments and the local slight enrichment in radiogenic Sr of the seawater. With sea level rise, after the deglaciation and during the Holocene, the river estuaries became progressively far away from the shelf break. Their competence of transport also became progressively reduced and the offshore transport of detrital sediments became progressively lower. Conversely the biogenic carbonate proportion in the sediments increased, due to lower dilution by the terrigenous particles. Simultaneously, the values of 87Sr/86Sr in the seawater at the KC 024-19 site became lower, as a consequence of a complete homogenization with the ocean global composition, which was now more effective with the increasing distance towards shoreline

Será o Implante de iStent® uma Cirurgia do Canal de Schlemm? Avaliação por OCT Spectral Domain de Segmento Anterior

Introdução: O iStent® “trabecular micro-bypass stent modelo GTS100R/L” tem resultados comprovados na cirurgia do glaucoma de ângulo aberto. Descrito como cirurgia ab interno do canal de Schlemm, visa criar um bypass entre a câmara anterior e este canal, ultrapassando a malha trabecular – principal resistência à drenagem de humor aquoso. Os autores visam estudar o papel do OCT de segmento anterior (SA) na localização do iStent® e uma eventual relação entre o seu posicionamento a eficácia hipotensora. Material e Métodos: Estudo transversal descritivo em que se avaliaram 17 olhos de 17 doentes submetidos a cirurgia de facoemulsificação combinada com iStent®, com um ano de follow-up. Estudou-se o ângulo irido-corneano com OCT spectral domain de SA (Heidelberg Spectralis®) e realizou-se uma avaliação oftalmológica que incluiu medição da pressão intra-ocular (PIO) com tonómetro de Goldmann e gonioscopia. Resultados: Em todos os olhos foi possível localizar o iStent® no ângulo da câmara anterior, porém apenas 4 pareciam estar no canal de Schlemm, estando os restantes na malha trabecular ou esporão escleral. Nos 4 olhos com implante no canal verificou-se uma redução média da PIO de 6,0 mmHg relativamente aos valores pré-operatórios, nos restantes essa redução foi 5,36 mmHg. Esta diferença não é estatisticamente significativa (p>0,05). Conclusões: O OCT spectral domain de SA é um método eficiente para determinar o posicionamento do iStent® no ângulo. Apesar da maioria das extremidades distais dos dispositivos não se encontrarem no canal de Schlemm, estes ultrapassaram a resistência da malha trabecular, pelo que a localização não parece comprometer a eficácia hipotensora.info:eu-repo/semantics/publishedVersio

Identification of yeasts isolated from wine-related environments and capable of producing 4-ethylphenol

www.elsevier.nl/locate/jnlabr/yfmic DOI:10.1016/S0740-0020(02)00152-1The ability to produce 4-ethylphenol from the substrate p-coumaric acid in synthetic media was evaluated for several yeast species associated with wine production.Molar conversion rates as high as 90% were found by only Dekkera bruxellensis, D. anomala and by some unidentified strains isolated from wine-related environments.Other unidentified strains produced traces of 4-ethylphenol. All unidentified strains showed the same cultural characteristics as D. bruxellensis when grown on DBDM (Dekkera/Brettanomyces differential medium) agar.The determination of long-chain fatty acid compositions and the utilization of peptide nucleic acid (PNA) probes specific for D. bruxellensis showed that the unidentified strains did not belong to this species.Further identification, by restriction pattern generated from PCR-amplification of the 5.8S rRNA gene and the two internal transcribed spacers (ITS), assigned the unidentified strains to Candida cantarelli, C. wickerhamii, Debaryomyces hansenii, Kluyveromyces lactis and Pichia guilliermondii.However, only some strains of P. guilliermondii were capable of converting p-coumaric acid into 4-ethylphenol with efficiencies close to those observed in D. bruxellensis and D. anomala

Blood flow in cylindrical stenosed channel – numerical approach

Arthrosclerosis means literally “arteries hardening”. However, arthrosclerosis it is a generic term that is related with three patterns of vascular diseases, which have the hardening and loss of elasticity of the arteries walls as a common factor [1]. The dominant pattern is atherosclerosis, characterized by the formation of atheroma, which is comprised by fibrous plaques that generally exhibit a centre rich in lipids. In the present work, the flow of blood in a cylindrical channel, containing an atheroma at the walls, has been numerically studied using the finite-element software package POLYFLOW®. In the simulations, blood was considered an incompressible homogenous fluid and the flow regime was the laminar regime. The rheology of the mentioned fluid was described by distinct constitutive equations [2] - constant viscosity, power-law model and Carreau model. The local behaviour of properties such as pressure, interstitial velocities, shear rate and shear stress was explored in the present investigation. The local behaviour of these properties can help to understand the formation and detachment of thrombi