Efeito da temperatura no perfil de ácidos graxos do óleo de girassol.

Neste trabalho são apresentados resultados de composição de óleos extraídos de girassóis, convencionais e alto oleico, semeados na safra e na safrinha, com o objetivo de investigar o efeito da temperatura na produção de óleo e na proporção dos principais ácidos graxos em sua composiçã

Phytochemical and antibacterial evaluation of essencial oils from Ottonia martiana Miq. (Piperaceae).

Três óleos essenciais extraídos das folhas, frutos e raízes de Ottonia martiana Miq. (Piperaceae), espécie comum da floresta Atlântica brasileira, e conhecida popularmente por “anestésia”, foram analisados por CG-EM e submetidos a um ensaio antibacteriano bioautográfico frente a Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 12228), Pseudomonas aerogenes (ATCC 27853) e Escherichia coli (ATCC 25922). Setenta e sete compostos foram identificados e submetidos a uma análise comparativa, a qual revelou uma variabilidade no teor dos componentes majoritários desses óleos (espatulenol, óxido de cariofileno, (E)-nerolidol, viridiflorol, ?-cariofileno, ? cadineno e aloaromadendreno). A presença de zonas de inibição de crescimento bacteriano nos bioautogramas analisados (Rfs 0,29 e 0,34) revelou o potencial antibacteriano dos óleos analisados frente às bactérias Gram-positivas testadas e permitiu identificar alguns dos componentes bioativos

Step-induced unusual magnetic properties of ultrathin Co/Cu films: ab initio study

We have performed ab initio studies to elucidate the unusual magnetic behavior recently observed in epitaxial Co films upon absorption of submonolayers of Cu and other materials. We find that a submonolayer amount of Cu on a stepped Co/Cu (100) film changes dramatically the electronic and magnetic structure of the system. The effect is mainly due to hybridization of Co and Cu $d$-electrons when copper forms a ``wire'' next to a Co step at the surface. As a result, a non-collinear arrangement of magnetic moments (switching of the easy axis) is promoted. [PACS 75.70.Ak,75.70.-i]Comment: 10 pages, RevTeX 3.0, 4 PostScript figures available on request from A. Bratkovsky at [email protected]

Ab initio study of the vapour-liquid critical point of a symmetrical binary fluid mixture

A microscopic approach to the investigation of the behaviour of a symmetrical binary fluid mixture in the vicinity of the vapour-liquid critical point is proposed. It is shown that the problem can be reduced to the calculation of the partition function of a 3D Ising model in an external field. For a square-well symmetrical binary mixture we calculate the parameters of the critical point as functions of the microscopic parameter r measuring the relative strength of interactions between the particles of dissimilar and similar species. The calculations are performed at intermediate ($\lambda=1.5$) and moderately long ($\lambda=2.0$) intermolecular potential ranges. The obtained results agree well with the ones of computer simulations.Comment: 14 pages, Latex2e, 5 eps-figures included, submitted to J.Phys:Cond.Ma

A 1H-NMR-based metabolomic analysis of propolis from Santa Catarina state

16th IUFoST World Congress of Food Science and Technology: Addressing Global Food Security and Wellness through Food Science and TechnologyPropolis is a resinous biomass produced by honeybees from exudates of local flora. It has been used since ancient times in folk medicine and in recent years has been added to foods and beverages to improve health and prevent diseases. The chemical composition of propolis is highly variable and depends on the climate, season, specie of bee, and mainly the local flora visited by bees to collect resin. In order to identify groups of chemical similarity among samples (n=20 autumn, n=16 winter, n=19 spring, n=17 summer) of propolis produced in Santa Catarina (SC) state (southern Brazil - 2010), lyophilized ethanolic extracts (200 mg/ml, EtOH 70%, v/v) were solubilized in MeOD3 (700l) and analyzed by NMR spectroscopy. One-dimensional 1HNMR spectra were acquired at a magnetic field strength of 500,13/125,03 MHz using a Varian Inova 500 MHz equipment and standard conditions of data acquisition. The 1H-NMR peak list data set was processed under MetaboAnalyst 2.0. suite, computing the resonances at 0.80- 12ppm spectral window. Principal Components Analysis (PCA) score scatter plots (PC1 88.2% x PC2 2.2%) clearly demonstrated samples discriminated mainly according to the season of production. These results suggest that not only geographical origin is important for the classification of propolis, but the seasonal effects as well. Since seasons directly influence the flora available from where bees collect resin, the propolis chemical profile can be significantly modified over the seasons even from a same geographical origin.info:eu-repo/semantics/publishedVersio

Avaliação do real potencial inibidor de extratos etanólicos de Ottonia martiana sobre Cylindrocladium spathulatum e Botrytis cinerea.

Extratos etanólicos de anestesia, Ottonia martiana Miq., foram reavaliados quanto à inibição do crescimento micelial dos fungos Cylindrocladium spathulatum (pinta-preta da erva-mate) e Botrytis cinerea (mofo-cinzento do eucalipto), por meio do planejamento fatorial. A ocorrência de decomposição de bioativos no processo de autoclavagem também foi investigada, por meio de teste de eficiência de extratos filtrados (filtro Millipore) e esterilizados (autoclave) no controle dos fitopatógenos, nas concentrações de 1, 10, 100 e 1000 ppm. Os extratos etanólicos filtrado e esterilizado inibiram o crescimento micelial dos fungos e foram mais ativos frente a B. cinerea. O extrato filtrado exibiu maior potencial antifúngico que o extrato esterilizado. O processo de esterilização por autoclavagem causou pequena decomposição dos bioativos presentes no extrato de anestesia

A hyperbolic slicing condition adapted to Killing fields and densitized lapses

We study the properties of a modified version of the Bona-Masso family of hyperbolic slicing conditions. This modified slicing condition has two very important features: In the first place, it guarantees that if a spacetime is static or stationary, and one starts the evolution in a coordinate system in which the metric coefficients are already time independent, then they will remain time independent during the subsequent evolution, {\em i.e.} the lapse will not evolve and will therefore not drive the time lines away from the Killing direction. Second, the modified condition is naturally adapted to the use of a densitized lapse as a fundamental variable, which in turn makes it a good candidate for a dynamic slicing condition that can be used in conjunction with some recently proposed hyperbolic reformulations of the Einstein evolution equations.Comment: 11 page

There and back again: molecular phylogenetics of the Brazilian endemic Psyllocarpus (Rubiaceae: Spermacoceae) supports a circumscription of the genus based on its original concept

The Spermacoce clade (tribe Spermacoceae) is one of the most taxonomically complex groups in Rubiaceae due to the unclear delimitation of Borreria and Spermacoce, in which several smaller genera are phylogenetically intermingled. One of these genera is the Brazilian endemic Psyllocarpus, whose circumscription was broadened, thereby including two sections. Psyllocarpus sect. Psyllocarpus, being based on the original genus delineation, includes nine species, distributed in the Cerrado and campo rupestre of eastern Brazil, whereas P. sect. Amazonica comprises three species, occurring in the Amazonian campinas. Furthermore, P. intermedius was not classified in any of these sections when it was later described. In order to test the monophyly of Psyllocarpus and assess its relationships to other genera, we conducted phylogenetic analyses, sampling across the whole Spermacoce clade, including nearly all Psyllocarpus species. A combined nuclear ribosomal (ETS and ITS) and plastid (rps16 and trnLtrnF) dataset was generated, representing 124 species (ca 25% of the species in the clade) in 15 genera (ca 65%). Various methodologies were applied to investigate the degree of incongruence among markers and address the lack of resolution and low support values for some branches. Our results revealed that Psyllocarpus is not monophyletic. Psyllocarpus campinorum (from P . sect. Amazonica) and P intermedius are situated as distinct lineages in the Spermacoce clade, yet do not belong to Psyllocarpus. Members of section Psyllocarpus form a strongly supported clade sister to Staelia and was recovered with high to maximum support across different datasets and inference methods. Therefore, Psyllocarpus has to be circumscribed based on its original concept, excluding P. sect. Amazonica and P. intermedius. This establishes the genus as a monophyletic and easily diagnosable taxon, characterized by terete leaves, homostylous flowers, a bilobate calyx, included stamens and style, and compressed, septifragally dehiscent capsules with a persistent septum

Dynamics of localized structures in vector waves

Dynamical properties of topological defects in a twodimensional complex vector field are considered. These objects naturally arise in the study of polarized transverse light waves. Dynamics is modeled by a Vector Complex Ginzburg-Landau Equation with parameter values appropriate for linearly polarized laser emission. Creation and annihilation processes, and selforganization of defects in lattice structures, are described. We find "glassy" configurations dominated by vectorial defects and a melting process associated to topological-charge unbinding.Comment: 4 pages, 5 figures included in the text. To appear in Phys. Rev. Lett. (2000). Related material at http://www.imedea.uib.es/Nonlinear and http://www.imedea.uib.es/Photonics . In this new version, Fig. 3 has been replaced by a better on