525 research outputs found

    Aceite de buriti de la Amazonia: caracterización química y potencial antioxidante

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    Buriti oil is an example of an Amazonian palm oil of economic importance. The local population uses this oil for the prevention and treatment of different diseases; however, there are few studies in the literature that evaluate its properties. In this study, detailed chemical and antioxidant properties of Buriti oil were determined. The predominant fatty acid was oleic acid (65.6%) and the main triacylglycerol classes were tri-unsaturated (50.0%) and di-unsaturated-mono-saturated (39.3%) triacylglycerols. The positional distribution of the classes of fatty acids on the triacylglycerol backbone indicated a saturated and unsaturated fatty acid relationship similar in the three-triacylglycerol positions. All tocopherol isomers were present, with a total content of 2364.1 mg·kg−1. α-tocopherol constitutes 48% of the total tocopherol content, followed by γ- tocopherol (45%). Total phenolic (107.0 mg gallic acid equivalent·g−1 oil) and β-carotene (781.6 mg·kg−1) were particularly high in this oil. The highest antioxidant activity against the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) was obtained at an oil concentration of 50 mg·mL−1 (73.15%). The antioxidant activity evaluated by the Oxygen Radical Absorbance Capacity (ORAC) was 95.3 μmol Trolox equivalent·g−1 oil. These results serve to present Buriti oil as an Amazonian resource for cosmetic, food and pharmaceuticals purposes672COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informação#2012- 22774-5; #2012-22829-4El aceite de Buriti es un ejemplo de aceite de palma amazónica de gran importancia económica. La población local utiliza este aceite para la prevención y el tratamiento de diferentes enfermedades; sin embargo, hay pocos estudios científicos que evalúen sus propiedades. En este estudio, se determinaron las propiedades antioxidantes del aceite de Buriti. El ácido graso predominante fue el oleico (65,6 %) y las principales clases de triglicéridos fueron tri-insaturadas (50,0 %) y Di-insaturados-mono-saturada (39,3 %). La distribución posicional de las clases de ácidos grasos en el esqueleto de triacilglicerol indicó una relación de ácidos grasos saturados e insaturados similar en las tres posiciones del triacilglicerol. Todas las isoformas de tocoferol estaban presentes, con un contenido total de 2364.1 mg·kg−1. El α-tocoferol constituye el 48 % del contenido total de tocoferol, seguido de γ-tocoferol (45 %). El contenido fenólico total (107,0 mg equivalente ácido gálico·g−1 de aceite) y β-caroteno (781,6 mg·kg−1) fueron particularmente altos en este aceite. La mayor actividad antioxidante contra el radical 1,1-difenil-2-picrilhidrazil libre (DPPH) se obtuvo a una concentración de aceite de 50 mg·mL−1 (73,15 %). La actividad antioxidante evaluadas por la capacidad de absorción de radicales de oxígeno (ORAC) fue 95,3 mmol Trolox equivalente·g−1 de aceite. Estos resultados presentan al aceite de Buriti amazónico como buen recurso con fines cosmético, alimenticio y farmacéutic

    Sting Millennium Suite: integrated software for extensive analyses of 3d structures of proteins and their complexes.

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    This article is intended to show how Sting Millennium Suite of programs can be useful in the study of protein structure and analysis of its function, emphasizing recent improvement introduced to SMS. The program has extensive built-in instructions and detailed easy-to-use help which user is invited to consult before and during SMS use.Na publicação: Paula R Kuser

    Características dos sistemas de produção de leite da região bragantina.

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    A Q-Ising model application for linear-time image segmentation

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    A computational method is presented which efficiently segments digital grayscale images by directly applying the Q-state Ising (or Potts) model. Since the Potts model was first proposed in 1952, physicists have studied lattice models to gain deep insights into magnetism and other disordered systems. For some time, researchers have realized that digital images may be modeled in much the same way as these physical systems (i.e., as a square lattice of numerical values). A major drawback in using Potts model methods for image segmentation is that, with conventional methods, it processes in exponential time. Advances have been made via certain approximations to reduce the segmentation process to power-law time. However, in many applications (such as for sonar imagery), real-time processing requires much greater efficiency. This article contains a description of an energy minimization technique that applies four Potts (Q-Ising) models directly to the image and processes in linear time. The result is analogous to partitioning the system into regions of four classes of magnetism. This direct Potts segmentation technique is demonstrated on photographic, medical, and acoustic images.Comment: 7 pages, 8 figures, revtex, uses subfigure.sty. Central European Journal of Physics, in press (2010

    Uma metodologia para seleção de parâmetros em modelos de classificação de proteínas.

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    Os principais desafios relacionados ao problema de classificação de enzimas em banco de dados de estruturas de proteínas são: 1) o ruído presente nos dados; 2) o grande número de variáveis; 3) o número não-balanceado de membros por classe. Para abordar esses desafios, apresenta-se uma metodologia para seleção de parâmetros, que combina recursos de matemática (ex: Transformada Discreta do Cosseno) e da estatística (ex:.g., correlação de variáveis e amostragem com reposição). A metodologia foi validada considerando-se os três principais métodos de classificação da literatura, a saber; árvore de decisão, classificação Bayesiana e redes neurais. Os experimentos demonstram que essa metodologia é simples, eficiente e alcança resultados semelhantes àqueles obtidos pelas principais técnicas para seleção de parâmetros na literatura.Termos para indexação classificação de enzimas,predição de função de proteínas, estruturas de proteínas, banco de dados de proteínas, seleção de parâmetros, métodos para classsificação de dados.bitstream/CNPTIA/11314/1/bp14.pdfAcesso em: 28 maio 2008

    Antifungal nanofibers made by controlled release of sea animal derived peptide

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    © The Royal Society of Chemistry 2015Candida albicans is a common human-pathogenic fungal species with the ability to cause several diseases including surface infections. Despite the clear difficulties of Candida control, antimicrobial peptides (AMPs) have emerged as an alternative strategy for fungal control. In this report, different concentrations of antifungal Cm-p1 (Cencritchis muricatus peptide 1) were electrospun into nanofibers for drug delivery. The nanofibers were characterized by mass spectrometry confirming the presence of the peptide on the scaffold. Atomic force microscopy and scanning electronic microscopy were used to measure the diameters, showing that Cm-p1 affects fiber morphology as well as the diameter and scaffold thickness. The Cm-p1 release behavior from the nanofibers demonstrated peptide release from 30 min to three days, leading to effective yeast control in the first 24 hours. Moreover, the biocompatibility of the fibers were evaluated through a MTS assay as well as ROS production by using a HUVEC model, showing that the fibers do not affect cell viability and only nanofibers containing 10% Cm-p1–PVA improved ROS generation. In addition, the secretion of pro-inflammatory cytokines IL-6 and TNF-α by the HUVECs was also slightly modified by the 10% Cm-p1–PVA nanofibers. In conclusion, the electrospinning technique applied here allowed for the manufacture of biodegradable biomimetic nanofibrous extracellular membranes with the ability to control fungal infectionThis work was supported by CAPES, FUNDECT, CNPq, FAPDF, UCB, Fundação para a Ciência e Tecnologia – Ministério da Educação e Ciência (FCT-MEC, Portugal) and the Calouste Gulbenkian Foundation (Portugal

    Fish out of water : consumers’ unfamiliarity with the appearance of commercial fish species

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    Seafood labels play an increasingly key role in assisting consumers in purchasing processed and featureless fish products, and in encouraging sustainable fishing and aquaculture practices. While informed purchasing choices are typically influenced by traceability and labelling awareness, they also depend on the consumers’ ability to identify and discriminate the fish species available on the market, which to date remains notably unexplored. We asked 720 people across six European countries to identify pictures of six fish species commonly sold in Europe. We reveal that European consumers have a poor understanding of the appearance of the fish they consume (overall ∼ 30% correct identification), with British consumers performing the poorest and Spanish ones doing best. We noted cultural association with some species, whereby the most regionally consumed fish are more easily recognized. We argue that despite recent improvements in technological solutions, stakeholder dialogue, and policy implementation, seafood market transparency will remain open to malpractice until consumers restore connection with their food
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