1,961 research outputs found

    Direct interaction between EgFABP1, a fatty acid binding protein from echinococcus granulosus, and phospholipid membranes

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    <p>Background: Growth and maintenance of hydatid cysts produced by Echinococcus granulosus have a high requirement for host lipids for biosynthetic processes, membrane building and possibly cellular and developmental signalling. This requires a high degree of lipid trafficking facilitated by lipid transporter proteins. Members of the fatty acid binding protein (FABP) family have been identified in Echinococcus granulosus, one of which, EgFABP1 is expressed at the tegumental level in the protoscoleces, but it has also been described in both hydatid cyst fluid and secretions of protoscoleces. In spite of a considerable amount of structural and biophysical information on the FABPs in general, their specific functions remain mysterious.</p> <p>Methodology/Principal Findings: We have investigated the way in which EgFABP1 may interact with membranes using a variety of fluorescence-based techniques and artificial small unilamellar vesicles. We first found that bacterial recombinant EgFABP1 is loaded with fatty acids from the synthesising bacteria, and that fatty acid binding increases its resistance to proteinases, possibly due to subtle conformational changes induced on EgFABP1. By manipulating the composition of lipid vesicles and the ionic environment, we found that EgFABP1 interacts with membranes in a direct contact, collisional, manner to exchange ligand, involving both ionic and hydrophobic interactions. Moreover, we observed that the protein can compete with cytochrome c for association with the surface of small unilamellar vesicles (SUVs).</p> <p>Conclusions/Significance: This work constitutes a first approach to the understanding of protein-membrane interactions of EgFABP1. The results suggest that this protein may be actively involved in the exchange and transport of fatty acids between different membranes and cellular compartments within the parasite.</p&gt

    Chemical changes of heat treated pine and eucalypt wood monitored by FTIR

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    A hardwood, Eucalyptus globulus Labill., and a softwood Pinus pinaster Aiton., were heat treated at temperatures between 170 and 210ºC in an oven and in an autoclave. The samples were pre-extracted with dichloromethane, ethanol and water and ground prior to Fourier Transform Infrared (FTIR) spectroscopic analysis. The heat treatment caused significant changes in the chemical composition and structure of wood, in lignin and polysaccharides. Hemicelluloses were the first to degrade as proved by the initial decrease of the 1730 cm-1 peak due to the breaking of acetyl groups in xylan. Hardwood lignin changed more than softwood lignin, with a shift of maximum absorption from 1505 cm-1 to approximately 1512 cm-1 due to decrease of methoxyl groups, loss of syringyl units or breaking of aliphatic side-chains. The macromolecular structure becomes more condensed and there is a clear increase of non-conjugated (1740 cm-1) in relation to conjugated groups (1650 cm-1). However, the changes induced by the thermal treatment are difficult to monitor by FTIR spectroscopy due to the different chemical reactions occurring simultaneously.info:eu-repo/semantics/publishedVersio

    Influência da raça na qualidade de couros caprinos

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    O estudo foi conduzido com o objetivo de avaliar a influência da raça na qualidade de couros caprinos. Foram utilizados cinco caprinos de cada uma das raças: Anglo Nubiana, Alpina e Saanen, com seis meses de idade. Os animais foram abatidos e as peles foram curtidas ao cromo e recurtidas com recurtente acrílico. Dos couros foram retiradas três amostras na posição paralela e três na perpendicular à linha dorsal para a avaliação da qualidade intrínseca de resistência à tração, ao rasgamento e ao lastômetro. As médias dos resultados foram comparadas pelo teste de Tukey ao nível de 5% de probabilidade. A raça não influenciou a resistência à distensão da superfície dos couros dos animais estudados no teste de lastômetro. As médias da resistência dos couros à tração foram maiores na posição longitudinal (P&#61500;0,05) para as três raças. Na posição longitudinal os couros dos caprinos Anglo Nubianos foram mais resistentes à tração (P<0,05), comparado com os couros das outras duas raças, que não apresentaram diferença entre si. A resistência dos couros ao rasgamento não sofreu influência da posição, porém na posição transversal os couros dos caprinos Anglo Nubianos foram mais resistentes (P<0,05), comparado com os couros das outras duas raças, que não apresentaram diferença entre si. A raça e a posição de retirada das amostras de couro influenciam a qualidade de couros caprinos

    Crescimento vegetativo de feijoeiro comum influenciado por diferentes épocas de plantio de adubos verdes.

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    O presente trabalho teve como objetivo avaliar a produção de massa fresca, massa seca, área foliar e índice de área foliar na cultura do feijoeiro comum em função das diferentes épocas de semeadura de adubos verdes.CONAFE

    Virtual environments to cope with anxiety situations: Two case-studies

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    Anxiety is a growing problem in modern societies. Virtual reality has been widely adopted to treat anxiety and more severe psychological problems. We have been working on an approach that involves compelling virtual environments (VE) to treat anxiety. These VE recreate a particular situation and support in real-time the intervention of the therapist. Public domain software tools and a simple projection screen have been used. This paper describes two interactive applications that simulate VE to help people coping with particular anxiety situations. One of the applications is developed in Blender and is dedicated to the fear of talking in front of an audience; the other application is developed in OpenSim and is devoted to the fear of driving inside a tunnel.info:eu-repo/semantics/acceptedVersio

    Silagem de Cana-de-açúcar tratada com cal hidratada - Ca(OH)2 - na terminação de bovinos da raça Canchim, em confinamento.

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    O presente trabalho foi conduzido no confinamento experimental da Embrapa Pecuária Sudeste, em São Carlos, SP, de maio a julho de 2011, a fim de avaliar o potencial da silagem de cana-de-açúcar tratada com 1% de cal hidratada (base matéria verde) como fonte de volumoso para terminação de bovinos em confinamento. Quarenta e cinco bovinos machos castrados da raça Canchim , com idade média de 22 meses e peso vivo médio de 345 kg, ao início do trabalho, foram alojados em baias individuais de 30 m2 e distribuídos em delineamento inteiramente casualizado entre 3 tratamentos (rações completas com diferentes volumosos): T1- ração com cana in natura; T2 - ração com silagem de cana e T3 - ração com silagem de milho. As rações experimentais foram formuladas segundo o modelo do NRC (1996) para que os tratamentos fossem isoenergéticos, proporcionando o mesmo ganho de peso, e contivessem teores semelhantes de fibra em detergente neutro. Os animais que receberam a ração contendo cana fresca apresentaram menor consumo de matéria seca e menor rendimento de carcaça que os demais (P0,05). Os dados obtidos no presente ensaio permitem concluir que a silagem de cana tratada com cal hidratada equivale a volumosos tradicionais como a cana-de-açúcar in natura ou a silagem de milho para terminação de bovinos em confinamento

    Correlação da contagem de células somáticas com o ganho de peso diário em ovinos de rebanhos de corte.

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    A contagem de células somáticas (CCS) apresenta-se elevada nas inflamações da glândula mamária ovina. Esse aumento na CCS, principalmente de origem infecciosa, pode afetar a qualidade nutricional do leite que é oferecido pela mãe à cria, o que resulta na diminuição do ganho de peso diário (GPD) dos cordeiros. Este trabalho teve como objetivo correlacionar a CCS do leite de fêmeas ovinas com e sem mastite com o GPD de seus cordeiros

    Adsorption of carbon dioxide, methane, and nitrogen on zn(Dcpa) metal-organic framework

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    Norma Transitória DL 57/2016 ELAC2014/BEE0367Adsorption-based processes using metal-organic frameworks (MOFs) are a promising option for carbon dioxide (CO2 ) capture from flue gases and biogas upgrading to biomethane. Here, the adsorption of CO2, methane (CH4 ), and nitrogen (N2 ) on Zn(dcpa) MOF (dcpa (2,6-dichloro-phenylacetate)) is reported. The characterization of the MOF by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), and N2 physisorption at 77 K shows that it is stable up to 650 K, and confirms previous observations suggesting framework flexibility upon exposure to guest molecules. The adsorption equilibrium isotherms of the pure components (CO2, CH4, and N2 ), measured at 273–323 K, and up to 35 bar, are Langmuirian, except for that of CO2 at 273 K, which exhibits a stepwise shape with hysteresis. The latter is accurately interpreted in terms of the osmotic thermodynamic theory, with further refinement by assuming that the free energy difference between the two metastable structures of Zn(dcpa) is a normally distributed variable due to the existence of different crystal sizes and defects in a real sample. The ideal selectivities of the equimolar mixtures of CO2 /N2 and CO2 /CH4 at 1 bar and 303 K are 12.8 and 2.9, respectively, which are large enough for Zn(dcpa) to be usable in pressure swing adsorption.publishersversionpublishe

    Two-column relay simulated moving-bed for gas-phase separations

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    A new two-column, relay, simulated moving bed process (2-column R-SMB) for gas-phase separations has been designed and implemented experimentally in this work. R-SMB differs from classical SMB processes by avoiding the partial withdrawal of products, since the outlet streams are handled in a relay mode. The outlet streams are either fully collected as product/waste or completely recycled to another column. In this work, the relay concept is applied for the first time in 2-column SMB processes and gas-phase separations. The process is designed and optimized through model-based computational simulation and the results obtained are validated experimentally. For the purpose, a new experimental lab-scale unit was designed and assembled. Please click Additional Files below to see the full abstract
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