681 research outputs found

    Determinação de vitamina C, fenóis totais, betalaínas e actividade antioxidante em figo da índia.

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    Comunicação da qual só está disponível o resumo.Os benefícios para a saúde do figo da índia estão relacionados com as suas propriedades antioxidantes, por sua vez associadas à presença nos frutos de ácido ascórbico, polifenóis, nomeadamente flavonoides e a uma mistura de pigmentos amarelos (betaxantinas) e vermelhos (betacianinas). A presença destes compostos nos frutos é muito variável e as metodologias aplicadas na sua análise também não são consensuais. No presente trabalho apresentam-se resultados obtidos no Laboratório de Química da ESACB, utilizando metodologias desenvolvidas para outros frutos, nomeadamente fenóis totais (método de Folin-Ciocalteu) e actividade antioxidante (método DPPH) e que foram adaptadas para frutos de Opuntia spp. No caso da avaliação de vitamina C não foi possível utilizar o método volumétrico da AOAC, já de aplicação corrente neste laboratório, que usa o reagente 2,6-diclorofenol-indofenol, pelas dificuldades associadas a amostras com intensa coloração. Assim, testou-se e adaptou-se um método por espectroscopia de absorção molecular para o qual se avaliaram alguns parâmetros de validação, nomeadamente linearidade, repetibilidade, limite de detecção e de quantificação. A quantificação de betacianinas e betaxantinas, por seu turno, foi realizada por espectroscopia de absorção molecular utilizando os coeficientes de extinção molar da betanina e da indicaxantina.info:eu-repo/semantics/publishedVersio

    Ácido ascórbico, betalaínas, e fenóis totais em ecótipos de Opuntia spp.

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    O género Opuntia spp. pertence à família Cactaceae, sendo a espécie Opuntia ficus-indica (OFI) a que tem maior importância económica. Em frutos de vinte populações provenientes de quatro espécies do género Opuntia spp. (OFI, O. robusta, O. dillenii and O. elata), com origem em Portugal, foram estudadas as características cromáticas, a acidez, o pH, o teor em sólidos solúveis totais (SST) e ainda os teores em ácido ascórbico (AA), betalaínas e fenóis totais (FT). As cultivares Italianas de OFI ‘Bianca’, ‘Gialla’ e ‘Rossa’ foram incluídas como termo de comparação. Os valores mais elevados de acidez foram registados nos frutos de O. dillenii e O. elata e os menores em OFI. Os frutos de O. dillenii apresentaram os teores mais elevados de betalaínas e FT, ao passo que as concentrações mais elevadas de AA foram registadas nos frutos de O. elata. Os ecótipos de OFI mostraram variação na concentração de compostos bioativos. Em OFI, a cv. de polpa vermelha ‘Rossa’ é a que apresenta maior concentração de betalaínas, seguida pelos ecótipos de polpa laranja e, finalmente, os ecótipos de polpa branca. Os valores mais elevados de FT foram encontrados nos ecótipos de polpa branca. O género Opuntia spp. é uma fonte de compostos bioativos, pelo que o consumo dos seus frutos representa uma boa forma de ingestão de compostos de elevado valor nutricional.info:eu-repo/semantics/publishedVersio

    Bioactive compounds and morphology in Opuntia spp. fruits from Portuguese ecotypes.

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    The Opuntia spp. has minimal soil and water requirements, and the O. ficus-indica, in particular is sought to be an alternative for the Mediterranean region agricultural economy. The morphology, bioactive compounds and antioxidant properties of fruits were studied in twenty Portuguese ecotypes belonging to four Opuntia species (O. ficus-indica, O. robusta, O. dillenii and O. elata). The ecotypes were compared with the O. ficus-indica cultivars ‘Bianca’, ‘Gialla’ and ‘Rossa’. The fruits from Opuntia spp. ecotypes displayed variability in morphological and bioactive characteristics. Among O. ficus-indica ecotypes, the orange pulp fruits were larger, heavier and had a higher percentage of pulp as well as a lower percentage of seeds compared to the white pulp fruits. However, the weight of 100 seeds was lower in the white pulp ecotypes. The OFI-04 ecotype contrasted the other OFI ecotypes due to its pale yellow pulp, ovoid shape, and low seed weight per fruit as well as the amount of seeds as a percentage of pulp weight. The O. dillenii ecotypes had the highest betalain content, total phenolic compounds, and antioxidant activity, while O. elata had the highest ascorbic acid content. Both O. dillenii and O. elata had the highest acidity values. The red pulp cv. Rossa had the highest betalain content among the O. ficus-indica populations, followed by the orange and white pulp ecotypes. The highest amount of total phenolic compounds was found in the white pulp O. ficus-indica ecotypes. The hierarchical clustering analysis revealed that the ecotypes could be grouped into four major groups, and geographical origin was unrelated to the clustering pattern. This study provides original data on the morphology and bioactive compounds of Opuntia spp. fruits from Portuguese ecotypes.info:eu-repo/semantics/publishedVersio

    Anatomical Features Of The Urethra And Urinary Bladder Catheterization In Female Mice And Rats. An Essential Translational Tool [características Anatômicas Da Cateterização Da Uretra E Bexiga De Camundongos E Ratos Fêmeas. Instrumento Essencial Na Pesquisa Pré Clínica]

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    PURPOSE: To present fundamental anatomical aspects and technical skills necessary to urethra and urinary bladder catheterization in female mice and rats. METHODS: Urethral and bladder catheterization has been widely utilized for carcinogenesis and cancer research and still remains very useful in several applications: from toxicological purposes as well as inflammatory and infectious conditions to functional aspects as bladder dynamics and vesicoureteral reflux, among many others. RESULTS: Animal models are in the center of translational research and those involving rodents are the most important nowadays due to several advantages including human reproducibility, easy handling and low cost. CONCLUSIONS: Although technical and anatomical pearls for rodent urethral and bladder access are presented as tackles to the advancement of lower urinary tract preclinical investigation in a broaden sight, restriction to female animals hampers the male microenvironment, demanding future advances.26SUPPL. 2106110Reis, L.O., Fávaro, W.J., Ferreira, U., Billis, A., Fazuoli, M.G., Cagnon, V.H., Evolution on experimental animal model for upper urothelium carcinogenesis (2010) World J Urol, 28, pp. 499-505Mulder, G.J., Scholtens, E., Meijer, D.K., Collection of metabolites in bile and urine from the rat (1981) Methods Enzymol, 77, pp. 21-30Krinke, G.J., (2000) The Laboratory Rat, , San Diego, CA: Academic PressPhillips, J.I., Davies, I., The comparative morphology of the bladder and urethra in young and old female C57BL/Icrfat mice (1980) Exp Geront, 15, pp. 551-562Andersson, K.E., Arner, A., Urinary bladder contraction and relaxation: Physiology and pathophysiology (2004) Physiol Rev, 84, pp. 935-986Reis, L.O., Pereira, T.C., Favaro, W.J., Cagnon, V.H., Lopes-Cendes, I., Ferreira, U., Experimental animal model and RNA interference: A promising association for bladder cancer research (2009) World J Urol, 27, pp. 353-361Marini, R.P., Esteves, M.I., Fox, J.G., A technique for catheterization of the urinary bladder in the ferret (1994) Lab Anim, 28, pp. 155-15

    Colimetry of marine waters off Fortaleza (Ceará State, Brazil) and detection of enteropathogenic Escherichia coli strains

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    Bacteriological analyses of seawater from three main beaches in Fortaleza, Brazil were performed during 1997. Thirty-six samples per beach were collected for a total of 108 samples. For Meireles Beach, 44% of the samples had MPN total coliforms values of at least 1100 or over 2400/100 ml, followed by Formosa and Diários beaches showing lower counts. For fecal coliforms the highest numbers were demonstrated for Formosa, followed by Meireles and Diários beaches in this descending order: 13.0%, 11.1% and 8.3%, respectively. Escherichia coli strains were identified in 76.8% of the 108 samples. Among 295 strains of E.coli, 21 belonged to serogroups O25, O26, O91, O112, O119, O158 and O164. Strains from serogroup O26 were tested using PCR, ELISA and Vero cells to detect Verotoxins VT1 and VT2 and all strains were negative. No LT and ST, as determined by ELISA and suckling mice assays, were detected among the 295 strains. All strains of E. coli were sensitive to ampicillin, cephalothin, gentamicin, tetracycline, sulfametox-trimethoprim, chloramphenicol and ciprofloxacin. Although the E. coli strains were not toxigenic, their presence in high numbers could be of public health significance

    Anomalous diffusion and Tsallis statistics in an optical lattice

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    We point out a connection between anomalous quantum transport in an optical lattice and Tsallis' generalized thermostatistics. Specifically, we show that the momentum equation for the semiclassical Wigner function that describes atomic motion in the optical potential, belongs to a class of transport equations recently studied by Borland [PLA 245, 67 (1998)]. The important property of these ordinary linear Fokker--Planck equations is that their stationary solutions are exactly given by Tsallis distributions. Dissipative optical lattices are therefore new systems in which Tsallis statistics can be experimentally studied.Comment: 4 pages, 1 figur

    Development of innovative hybrid sandwich panel slabs: Experimental results

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    The authors appreciate the collaboration of the following labs: Civitest for developing DHCC materials, PIEP for conducting VARTM process (Eng. Luis Oliveira) and Department of Civil Engineering of Minho University to perform the tests (Mr. Antonio Matos and Eng. Marco Jorge).In this paper, a new generation of composite sandwich slab is proposed as a solution for the rehabilitation of slabs in old masonry buildings. An innovative solution was developed during this research formed by four components: a Deflection Hardening Cement Composite (DHCC) layer on the top compression skin, a glass fiber reinforced polymer (GFRP) skin at the bottom tension surface, GFRP ribs to transfer shear from top to bottom layers, and foam core for thermal-insolation purposes. The DHCC layer contributes significantly for the load carrying and deflection capacity due to its stiffness, compressive strength and toughness, offers resistance to the occurrence of buckling phenomena in the GFRP ribs, improves the performance of this structural concept against impact and fire, and constitutes an excellent medium for the application of finishing materials, like ceramics or timber. Two different hybrid composite slabs were developed and tested, and their behavior was assessed under flexural loading. The results showed that the developed hybrid sandwich slabs accomplish all design requisites for serviceability and ultimate limit states, and assure a stiffness/dead-weight and load-capacity/dead-weight ratios much higher than conventional structural slab systems.FCT - Fundação para a Ciência e Tecnologi

    Aeromonas spp. isoladas de ostras (Crassostrea rhizophorea) coletadas em um criadouro natural, Ceará, Brazil

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    Between April and October 2002, thirty fortnightly collections of oysters (Crassostrea rhizophorea) from a natural oyster bed at the Cocó River estuary in the Sabiaguaba region (Fortaleza, Ceará, Brazil) were carried out, aiming to isolate Aeromonas spp. strains. Oyster samples were submitted to the direct plating (DP) and the presence/absence (P/A) methods. Aeromonas were identified in 15 (50%) samples analyzed by the DP method and in 13 (43%) analyzed by the P/A method. A. caviae, A. eucrenophila, A. media, A. sobria, A. trota, A. veronii bv. sobria, A. veronii bv. veronii and Aeromonas sp. were isolated. The predominant species was A. veronii (both biovars), which was identified in 13 (43%) samples, followed by A. media in 11 (37%) and A. caviae in seven (23%). From the 59 strains identified, 28 (48%) presented resistance to at least one of the eight antibiotics tested.Foram realizadas 30 coletas quinzenais, entre abril e outubro de 2002, de ostras (Crassostrea rhizophorea) de um criadouro natural, no estuário do rio Cocó (Fortaleza/Ceará/Brasil), objetivando-se isolar cepas de Aeromonas spp. As amostras de ostras foram submetidas aos métodos de plaqueamento direto (PD) e presença/ausência (P/A). Foram identificadas Aeromonas em 15 (50%) amostras analisadas pelo método PD e em 13 (43%) pelo método P/A. Foram isoladas: A. caviae, A. eucrenophila, A. media, A. sobria, A. trota, A. veronii bv. sobria, A. veronii bv. veronii e Aeromonas sp. A espécie predominate foi A. veronii (ambos biovars), identificada em 13 (43%) amostras, seguida de A. media em 11 (37%) e A. caviae em 7 (23%). Das 59 cepas identificadas, 28 (48%) apresentaram resistência a pelo menos um, dos oitos antibióticos testados

    Ramond-Ramond Fields, Fractional Branes and Orbifold Differential K-Theory

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    We study D-branes and Ramond-Ramond fields on global orbifolds of Type II string theory with vanishing H-flux using methods of equivariant K-theory and K-homology. We illustrate how Bredon equivariant cohomology naturally realizes stringy orbifold cohomology. We emphasize its role as the correct cohomological tool which captures known features of the low-energy effective field theory, and which provides new consistency conditions for fractional D-branes and Ramond-Ramond fields on orbifolds. We use an equivariant Chern character from equivariant K-theory to Bredon cohomology to define new Ramond-Ramond couplings of D-branes which generalize previous examples. We propose a definition for groups of differential characters associated to equivariant K-theory. We derive a Dirac quantization rule for Ramond-Ramond fluxes, and study flat Ramond-Ramond potentials on orbifolds.Comment: 46 pages; v2: typos correcte
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