615 research outputs found

    The effect of home storage conditions and packaging materials on the quality of frozen green beans

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    Home storage is the final step of the frozen foods distribution chain, and little is known on how it affects the products quality. The present research describes frozen green beans (Phaseolus vulgaris, L.) quality retention profile during the recommended ‘star marking’ system dates, at the storage temperatures of þ5,26, 212 and 218 8C (along 1, 4, 14 and 60 days, respectively). The quality profile was assessed by a simulation system. Simulations were set by a response surface methodology to access the effect of different packaging materials (thermal conductivities and thickness), surface heat transfer coefficient, and refrigerator dynamics (effect of refrigeration cycles at the different storage temperatures) on the average retentions of Ascorbic Acid, total vitamin C, colour and flavour. Green beans quality losses along frozen storage are significantly influenced by temperature, refrigerator dynamics and kinetic properties. Quality is also highly dependent on packaging materials thermal insulation (e.g. at temperatures above the melting point). Temperature cycles inside frozen chambers have a long term effect, and at the higher storage temperatures (e.g. T . 26 8C) are detrimental to frozen green beans quality after shorter periods

    Intra-molecular properties of DMeOPPV studied by quantum molecular dynamics

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    Introducing methoxy electron donor groups into a poly(para-phenylene vinylene) (PPV) chain will lead to the appearance of unique electronic properties at the molecular scale which should affect the overall properties of light-emitting diodes based on these polymers. Self-consistent quantum molecular dynamics calculations have been used to provide information on intra-molecular properties of poly(2,5-dimethoxy-para-phenylene vinylene) (DMeOPPV), which are relevant for the modelling and characterization of polymer light-emitting diodes at nanometric length scale. We focus our attention on those properties that have been somewhat neglected in previous literature: the charge distribution associated with positive and negative charge carriers and their intra-molecular mobility when an electric field is applied.Fundação para a Ciência e a Tecnologia (FCT) – Programa Operacional “Ciência, Tecnologia, Inovação” - POCTI/CTM/41574/2001, SFRH/BD/11231/2002.Comunidade Europeia (CE). Fundo Europeu de Desenvolvimento Regional (FEDER

    Effect of molecular properties on the performance of polymer light-emitting diodes

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    The performance of a single layer polymer light-emitting diode depends on several interdependent factors, although recombination between electrons and holes within the polymer layer is believed to play an important role. Our aim is to carry out computer experiments in which bipolar charge carriers are injected in polymer networks made of poly(p-phenylene vinylene) chains randomly oriented. In these simulations, we follow the charge evolution in time from some initial state to the steady state. The intra-molecular properties of the polymer molecules obtained from self-consistent quantum molecular dynamics calculations are used in the mesoscopic model. The purpose of the present work is to clarify the effects of intra-molecular charge mobility and energy disorder on recombination efficiency. In particular, we find that charge mobility along the polymer chains has a serious influence on recombination within the polymer layer. Our results also show that energy disorder due to differences in ionization potential and electron affinity of neighbouring molecules affects mainly recombinations that occur near the electrodes at polymer chains parallel to them.Fundação para a Ciência e a Tecnologia (FCT) – Programa Operacional “Ciência, Tecnologia, Inovação” - POCTI/CTM/41574/2001Comunidade Europeia (CE). Fundo Europeu de Desenvolvimento Regional (FEDER

    Influence of the biquadratic interlayer coupling in the specific heat of Fibonacci magnetic multilayers

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    A theoretical study of the specific heat C(T) as a function of temperature in Fibonacci magnetic superlattices is presented. We consider quasiperiodic structures composed of ferromagnetic films, each described by the Heisenberg model, with biquadratic and bilinear coupling between them. We have taken the ratios between the biquadratic and bilinear exchange terms according to experimental data recently measured for different regions of their regime. Although some previous properties of the spin wave specific heat are also reproduced here, new features appear in this case, the most important of them being an interesting broken-symmetry related to the interlayer biquadratic term.Comment: 13 pages, 4 ps figures, Submitted to Physica

    Serum Lipid Profile Of Broilers Fed Diets With Inclusion Of Mango Waste Meal

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    We evaluated the effect of including 2.5, 5.0, 7.5 and 10.0% mango waste meal (MWM) variety UBA in corn and soybean meal-based diet son the serum lipid profile of broilers. The experimental design was completely randomized, with five treatments and six replicates with 20 birds per experimental unit. Concentrations of creatinine, albumin, total protein, total cholesterol, triacylglycerols (TAG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and very-low-density lipoprotein cholesterol (VLDL-C), were evaluated at the ages of 14, 28 and 42 days, with 30 birds evaluated per age. At 14 days, there was no difference serum creatinine, total cholesterol, HDL, triacylglycerols, total proteins or VLDL-C concentrations as compared with control. Albumin concentration was the highest at the MWM inclusion levels of 5.0, 7.5 and 10.0%. At 28 days, triacylglycerols, VLDL-C and LDL-C were the lowestat 7.5% inclusion whereas at 42 days, these same variables were the lowest with addition of 10.0% meal. At 14, 28 and 42 days of age, the VLDL-C, LDL-C and total TAG contents were found to decrease at mango waste meal inclusion levels of 5.0 and 7.5% in the diets, which maybe considered an indicator of improvements in the metabolic conditions of broilers.3753327333

    Sorovares de Salmonella isolados de humanos no Estado de São Paulo, Brasil, 1996-2003

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    A salmonelose permanece uma importante causa de doença diarréica em humanos no Estado de São Paulo, Brasil. Nesse estudo foram identificados 3554 isolados de Salmonella de infecções humanas, durante o período 1996-2003. Entre os 68 diferentes sorovares determinados, S. Enteritidis foi predominante em infecções gastrointestinais e extra-intestinais, responsável por 67.4% de todos os isolados. S. Typhimurium e S. enterica subsp. enterica (4,5,12:i:-) foram mais freqüentemente isolados de crianças com idade de < 1 a 4 anos, em contraste, infecções por S. Enteritidis foram predominantes em pessoas entre 20 e 50 anos. A contínua vigilância laboratorial das salmoneloses, incluindo a sorotipagem, tem evidenciado os sorovares de Salmonella causando infecções humanas em nossa área geográfica ao longo do tempo.Salmonellosis remains an important cause of diarrheal illness in humans in São Paulo State, Brazil. In this study were identified 3554 Salmonella isolates from human infections, during the period 1996-2003. Among 68 different serovars determined, S. Enteritidis was the most frequent one in gastrointestinal and extra-intestinal infections accounting for 67.4% of all isolates. S. Typhimurium and S. enterica subsp. enterica (4,5,12:i:-) were most frequently isolated from children aged < 1-4 year-old, in contrast, people with S. Enteritidis infections were most likely to be 20-50 year-old. In our geographic area the continued laboratorial surveillance of salmonellosis, including serotyping, has showed the trends in Salmonella serovars causing infections in humans throughout the time

    PROP1 and CTNNB1 expression in adamantinomatous craniopharyngiomas with or without β-catenin mutations

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    INTRODUCTION: Activating mutations in exon 3 of the &#946;-catenin gene are involved in the pathogenesis of adamantinomatous craniopharyngiomas. Recently, the interaction between &#946;-catenin and PROP1 has been shown to be responsible for pituitary cell lineage determination. We hypothesized that dysregulated PROP1 expression could also be involved in the pathogenesis of craniopharyngiomas OBJECTIVES: To determine whether dysregulated gene expression was responsible for tumor pathogenesis in adamantinomatous craniopharyngiomas, the &#946;-catenin gene was screened for mutations, and the expression of the &#946;-catenin gene and PROP1 was evaluated. &#946;-catenin gene was amplified and sequenced from 14 samples of adamantinomatous craniopharyngiomas. PROP1 and &#946;-catenin gene expression was assessed by real-time RT-PCR from 12 samples, and &#946;-catenin immunohistochemistry was performed on 11 samples. RESULTS: Mutations in the &#946;-catenin gene were identified in 64% of the adamantinomatous craniopharyngiomas samples. Evidence of &#946;-catenin gene overexpression was found in 71% of the tumors with &#946;-catenin mutations and in 40% of the tumors without mutations, and &#946;-catenin immunohistochemistry revealed a nuclear staining pattern for each of the analyzed samples. PROP1 expression was undetectable in all of the tumor samples. CONCLUSION: We found evidence of &#946;-catenin gene overexpression in the majority of adamantinomatous craniopharyngiomas, and we also detected a nuclear &#946;-catenin staining pattern regardless of the presence of a bcatenin gene mutation. These results suggest that WNT signaling activation plays an important role in the pathogenesis of adamantinomatous craniopharyngiomas. Additionally, this study was the first to evaluate PROP1 expression in adamantinomatous craniopharyngiomas, and the absence of PROP1 expression indicates that this gene is not involved in the pathogenesis of this tumor, at least in this cohort

    Extensive Sheep and Goat Production: The Role of Novel Technologies towards Sustainability and Animal Welfare

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    ReviewSheep and goat extensive production systems are very important in the context of global food security and the use of rangelands that have no alternative agricultural use. In such systems, there are enormous challenges to address. These include, for instance, classical production issues, such as nutrition or reproduction, as well as carbon-efficient systems within the climate-change context. An adequate response to these issues is determinant to economic and environmental sustainability. The answers to such problems need to combine efficiently not only the classical production aspects, but also the increasingly important health, welfare, and environmental aspects in an integrated fashion. The purpose of the study was to review the application of technological developments, in addition to remote-sensing in tandem with other state-of-the-art techniques that could be used within the framework of extensive production systems of sheep and goats and their impact on nutrition, production, and ultimately, the welfare of these species. In addition to precision livestock farming (PLF), these include other relevant technologies, namely omics and other areas of relevance in small-ruminant extensive production: heat stress, colostrum intake, passive immunity, newborn survival, biomarkers of metabolic disease diagnosis, and parasite resistance breeding. This work shows the substantial, dynamic nature of the scientific community to contribute to solutions that make extensive production systems of sheep and goats more sustainable, efficient, and aligned with current concerns with the environment and welfareinfo:eu-repo/semantics/publishedVersio
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