317 research outputs found

    Automated design of DNA origami

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    Banana as adjunct in beer production: applicability and performance of fermentative parameters

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    Traditionally, the raw materials for beer production are barley, hops, water, and yeast, but most brewers use also different adjuncts. During the alcoholic fermentation, the contribution of aroma compounds from other ingredients to the final beer flavor depends on the wort composition, on the yeast strain, and mainly on the process conditions. In this context, banana can also be a raw material favorable to alcoholic fermentation being rich in carbohydrates and minerals and providing low acidity. In this work, the objective was to evaluate the performance of wort adjusted with banana juice in different concentrations. For this, static fermentations were conducted at 15 °C at pilot scale (140 L of medium). The addition of banana that changed the concentration of all-malt wort from 10 °P to 12 and 15 °P were evaluated (°P is the weight of the extract or the sugar equivalent in 100 g solution, at 20 °C). The results showed an increase in ethanol production, with approximately 0.4 g/g ethanol yield and 0.6 g/L h volumetric productivity after 84 h of processing when concentrated wort was used. Thus, it was concluded that banana can be used as an adjunct in brewing methods, helping in the development of new products as well as in obtaining concentrated worts.Fundação para a Ciência e a Tecnologia (FCT)EMATER-MGJohnson-DiverseyFapesp (Fundação de Amparo à Pesquisa do Estado de São Paulo/Brasil)Wallerstein Industrial & CommercialNovozymesCAPES (Coordenação para Aperfeiçoamento do Ensino Superior/ Brasil)Malteria do ValeGRICES (Gabinete de Relações Internacionais da Ciência e do Ensino Superior/Portugal

    Continuous immobilized yeast reactor system for complete beer fermentation using spent grains and corncobs as carrier materials

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    Despite extensive research carried out in the last few decades, continuous beer fermentation has not yet managed to outperform the traditional batch technology. An industrial breakthrough in favour of continuous brewing using immobilized yeast could be expected only on achievement of the following process characteristics: simple design, low investment costs, flexible operation, effective process control and good product quality. The application of cheap carrier materials of by-product origin could significantly lower the investment costs of continuous fermentation systems. This work deals with a complete continuous beer fermentation system consisting of a main fermentation reactor (gas-lift) and a maturation reactor (packedbed) containing yeast immobilized on spent grains and corncobs, respectively. The suitability of cheap carrier materials for long-term continuous brewing was proved. It was found that by fine tuning of process parameters (residence time, aeration) it was possible to adjust the flavour profile of the final product. Consumers considered the continuously fermented beer to be of a regular quality. Analytical and sensorial profiles of both continuously and batch fermented beers were compared.(Fundação de Amparo a Pesquisa do Estado de São Paulo, Brazil (FAPESPFundação para a Ciência e a Tecnologia (FC

    Chemical preservatives in foodstuffs. III Hexamethylenetetramine as mold inhibitor and the antagonistic action of amino acids

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    Growth and respiration tests carried out on Aspergillus, Cladosporium and Penicillium molds have shown that certain amino acids such as 1-tryptophan and 1-cysteine and certain sulphydryl compounds such as glutathione and thioglycollic acid counteract the inhibitory action of hexamethylenetetramine. In the absence of hexamethylenetetramine, these compounds inhibit the growth of the molds. The dependence of the antagonistic action on the amino acid concentration differed for 1-cysteine and 1-tryptophan. The respiration of the mold was a maximum when equimolar concentrations of 1-cysteine and of the formaldehyde formed by the decomposition of hexamethylenetetramine were present in the culture media. The antagonistic effect of 1-tryptophan increased continuously with increasing concentration until the rate of oxygen consumption was the same as in the control test with no hexamethylenetetramine or antagonist present. The antagonistic effect of these four compounds on hexamethylenetetramine or on formaldehyde is evidently due to chemical interaction. The inhibitory effect of hexamethylenetetramine on the microbial cell may at least partly be due to its ability to inactivate enzymes such as the dehydrogenases

    Behaviour of muscle protein fractions of broilers during freezing and frozen storage

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    A method has been introduced for the analysis of protein fractions in chicken, in analogy with similar fractionation used for fish muscle proteins. The percentage figures for the most important protein fractions in the breast muscle of 9-week-old broilers were found to be: sarcoplasmic protein 30, »myosin» 59, giving a total of soluble proteins of 89, and stroma proteins 11 per cent. This method was applied to follow possible changes in the solubility of »myosin» during post-mortem aging and subsequent freezing and frozen storage. At the same time, there were determined the pH and water-binding capacity. Organoleptic evaluation was used as a check. It was found that the solubility of »myosin» was lowered only in broilers frozen without aging, after 1 month of storage. Simultaneously, water-binding capacity was lowered, and the meat proved tough by organoleptic test. Prolonged frozen storage, by contrast, caused no loss in solubility of »myosin». The water-binding capacity was lowered after prolonged storage, particularly in broilers frozen without aging

    Heat and moisture exchangers (HMEs) and heated humidifiers (HHs) in adult critically ill patients: a systematic review, meta-analysis and meta-regression of randomized controlled trials

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    The aims of this systematic review and meta-analysis of randomized controlled trials are to evaluate the effects of active heated humidifiers (HHs) and moisture exchangers (HMEs) in preventing artificial airway occlusion and pneumonia, and on mortality in adult critically ill patients. In addition, we planned to perform a meta-regression analysis to evaluate the relationship between the incidence of artificial airway occlusion, pneumonia and mortality and clinical features of adult critically ill patients

    The role of the <i>Ah</i> locus in hexachlorobenzene-induced porphyria. Studies in congenic C57BL/6J mice

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    The role of the Ah locus in hexachlorobenzene (HCB)-induced porphyria and the possible involvement of P-450 cytochromes P(1)450 and P(3)450 in the pathogenesis of this disease were investigated in two congenic strains of C57BL/6J mice that differ only at this locus. Female B6-Ahb mice (Ah receptor: approximately 30-70 fmol/mg of cytosolic protein) and B6-Ahd mice (Ah receptor: undetectable) were pretreated with iron (500 mg/kg) and then fed a diet containing 0 or 200 p.p.m. of HCB for up to 17 weeks. Mice from the two strains consumed similar amounts of HCB. Urinary excretion of porphyrins was increased after 7 weeks of HCB treatment in B6-Ahb mice, and after 15 weeks was over 200 times greater than that of mice given iron only. In B6-Ahd mice, porphyrin excretion did not begin to increase until after 13 weeks, and after 15 weeks was only six times greater than that of controls. Similar differences were seen in the 15-week hepatic porphyrin concentrations (B6-Ahb: 1110 +/- 393; B6-Ahd: 17.6 +/- 14.5; controls: approximately 0.20 nmol/g). Uroporphyrinogen decarboxylase (EC 4.1.1.37) activity was diminished by 70 and 20% in B6-Ahb B6-Ahd mice respectively after 15 weeks of treatment with HCB. Cytochromes P(1)450 and P(3)450 were measured in hepatic microsomes (microsomal fractions) by radioimmunoassay and immunoblotting, using antisera raised against the orthologous rat isoenzymes P450c and P450d. HCB induced small amounts of a protein recognized by anti-P450c (P(1)450) in B6-Ahd mice, but not in B6-Ahd mice. Relatively large amounts of a protein recognized by anti-P450d (P(3)450) were induced in both strains, but to a somewhat greater extent in the B6-Ahb mice. The hepatic accumulation of HCB at 15 weeks was greater in B6-Ahb than in B6-Ahd mice, in association with elevated hepatic lipid levels in the former strain. The results of this experiment indicate that the Ah locus influences the susceptibility of C57BL/6J mice to HCB-induced porphyria and are consistent with the suggestion that the sustained induction of P(3)450 and/or P(1)450 may be a causative factor in the development of this disease.</jats:p

    15-Year Follow-up of Neuromuscular Function in Patients With Unilateral Nonreconstructed Anterior Cruciate Ligament Injury Initially Treated With Rehabilitation and Activity Modification: A Longitudinal Prospective Study.

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    Background: It has been suggested that neuromuscular function is of importance in the overall outcome after anterior cruciate ligament (ACL) injury. Hypothesis: Good neuromuscular function can be achieved and maintained over time in subjects with ACL injury treated with rehabilitation and activity modification but without reconstructive surgery. Study Design: Case series; Level of evidence, 4. Methods: One hundred consecutive patients (42 women and 58 men) with acute ACL injury at a nonprofessional, recreational or competitive activity level were assessed 1, 3, and 15 years after injury. Their mean age at inclusion was 26 years (range, 15-43 years). All patients initially underwent rehabilitation and were advised to modify their activity level, especially by avoiding contact sports. Patients with recurrent giving-way episodes or secondary meniscal injuries that required fixation were subsequently excluded and underwent reconstruction of the ACL. Sixty-seven patients (71% of those available for follow-up) with unilateral nonreconstructed injury remained at the 15-year follow-up. Fifty-six of these 67 patients were examined with the single-legged hop test for distance and knee muscle strength. The limb symmetry index (LSI), calculated by dividing the result for the injured leg by that of the uninjured leg and multiplying by 100, was used for comparisons over time (paired t test). Results: The LSI for the single-legged hop test was higher at the 3-year follow-up (mean, 98.5%; standard deviation [SD], 7.6%) than at the 15-year follow-up (mean, 94.8%; SD, 10.5%) (mean difference, -3.7%; 95% confidence interval [Cl], -6.1% to -1.2%; P = .004). The LSI for isometric extension was higher at the 15-year follow-up (mean, 97.2%; SD, 13.7%) than at the 1-year follow-up (mean, 88.2%; SD, 15.4%) (mean difference, 9.0%; 95% Cl, 3.7% to 14.4%; P = .001). At the 15-year follow-up, between 69% and 85% of the patients had an LSI >= 90%. Conclusions: Good functional performance and knee muscle strength can be achieved and maintained over time in the majority of patients with ACL injury treated with rehabilitation and early activity modification but without reconstructive surgery

    Applications of yeast flocculation in biotechnological processes

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    A review on the main aspects associated with yeast flocculation and its application in biotechnological processes is presented. This subject is addressed following three main aspects – the basics of yeast flocculation, the development of “new” flocculating yeast strains and bioreactor development. In what concerns the basics of yeast flocculation, the state of the art on the most relevant aspects of mechanism, physiology and genetics of yeast flocculation is reported. The construction of flocculating yeast strains includes not only the recombinant constitutive flocculent brewer’s yeast, but also recombinant flocculent yeast for lactose metabolisation and ethanol production. Furthermore, recent work on the heterologous β-galactosidase production using a recombinant flocculent Saccharomyces cerevisiae is considered. As bioreactors using flocculating yeast cells have particular properties, mainly associated with a high solid phase hold-up, a section dedicated to its operation is presented. Aspects such as bioreactor productivity and culture stability as well as bioreactor hydrodynamics and mass transfer properties of flocculating cell cultures are considered. Finally, the paper concludes describing some of the applications of high cell density flocculation bioreactors and discussing potential new uses of these systems.Fundação para a Ciência e a Tecnologia (FCT) – PRAXIS XXI - BD11306/97
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