165 research outputs found

    Fast HPLC analysis of omeprazole, 5-hydroxyomeprazole and omeprazole sulfone in liquid culture medium using a monolithic column for application in biotransformation studies with fungi

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    A fast liquid chromatography method was developed and validated for the simultaneous determination of omeprazole (OMZ), 5-hydroxyomeprazole (5-HOMZ) and omeprazole sulphone (OMZ SUL) in liquid culture medium for application in biotransformation studies employing phytopathogenic and endophytic fungi. The separation was achieved using a monolithic Chromolith Fast gradient RP 18 endcapped column, using a mobile phase consisting of 0.15% (v/v) trifluoroacetid acid (TFA) in water (solvent A) and 0.15% (v/v) TFA in acetonitrile (solvent B), under linear gradient of 5 to 90% of B in 1 min, flow rate of 1.0 mL min-1, temperature at 30 ºC and detection at 220 nm. Sample preparation was performed by liquid-liquid extraction, with recoveries in the range of 62.3 to 76.6% for all analytes. The method was linear in the range of 0.2 to 10.0 µg mL-1 (r &#8805; 0.995). The values for intra- and inter-day precision (% coefficient of variation) and accuracy (% relative error) were < 15% for all analytes. The validated method was used to evaluate OMZ biotransformation to their mammalian metabolites by selected fungi. In general, the phytopathogenic fungi studied were more efficient to biotransform OMZ. The sulfonation reaction was more prevalent for all studied fungi.Um método rápido por cromatografia líquida foi desenvolvido para a determinação simultânea de omeprazol (OMZ), 5-hidroxiomeprazol (5-HOMZ) e omeprazol sulfona (OMZ SUL) em meio de cultura líquido, para aplicação em estudos de biotransformação empregando fungos fitopatogênicos e endofíticos. A separação foi realizada empregando uma coluna monolítica Chromolith Fast gradient RP 18 com a fase móvel constituída por ácido trifluoroacético (TFA) 0,15% (v/v) em água (solvente A) e TFA 0,15% (v/v) em acetonitrila (solvente B). Foi empregado um gradiente linear de 5 a 90% de B em 1 minuto, vazão de 1,0 mL min-1, temperatura de 30 ºC e detecção em 220 nm. A extração líquido-líquido foi empregada na preparação das amostras, com recuperações na faixa de 62,3-76,6% para todos os analitos. O método foi linear na faixa de 0,2-10,0 µg mL-1 (r &#8805; 0,995). Os valores de precisão e exatidão intra- e inter-dias (coeficiente de variação e erro relativo) foram inferiores a 15% para todos os analitos. O método validado foi utilizado para avaliar a biotransformação do OMZ em seus principais metabólitos humanos pelos fungos selecionados. Em geral, os fungos fitopatogênicos foram mais eficientes para biotransformar o OMZ. A reação de sulfonação foi mais prevalente em todos os fungos estudadosFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Uso de giroscópio para auxiliar pessoas com deficiência múltiplas no uso do Dosvox

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    This article describes a solution that allows people with visual impairments who also have the inability to use hands, to have access to the Dosvox system, a system that enables the interaction between the visually impaired. In this solution, the Dosvox, whose operation is originally performed solely by keyboard, now can be operated via a gyroscope coupled to the user's head, whose movement is translated into a series of keystrokes, chosen to provide the full operation of the menus Dosvox which correspond to a high percentage of interaction with this system. The solution identified several problems to be solved, they were treated by means of algoritms and techniques presented in the article.Este artigo descreve uma solução que permite à pessoas com deficiência visual, que também têm impossibilidade de utilizar as mãos, possam ter acesso ao sistema Dosvox, um sistema que possibilita a interação entre deficiente visual e o computador. O Dosvox é uma das tecnologias assistivas mais utilizadas no Brasil, por deficientes visuais. Nesta solução, o Dosvox, cuja operação é originalmente realizada unicamente pelo teclado, passa a poder ser operado através de um giroscópio, acoplado à cabeça do usuário, cujo movimento é traduzido numa série de acionamentos de teclas, escolhidas para proporcionar a operação plena dos menus do Dosvox, que correspondem a um alto percentual da interação com este sistema. A solução identificou diversos problemas a serem resolvidos e que foram tratados através de algoritmos e técnicas apresentados no artigo

    Influence of Delayed Conductance on Neuronal Synchronization

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    In the brain, the excitation-inhibition balance prevents abnormal synchronous behavior. However, known synaptic conductance intensity can be insufficient to account for the undesired synchronization. Due to this fact, we consider time delay in excitatory and inhibitory conductances and study its effect on the neuronal synchronization. In this work, we build a neuronal network composed of adaptive integrate-and-fire neurons coupled by means of delayed conductances. We observe that the time delay in the excitatory and inhibitory conductivities can alter both the state of the collective behavior (synchronous or desynchronous) and its type (spike or burst). For the weak coupling regime, we find that synchronization appears associated with neurons behaving with extremes highest and lowest mean firing frequency, in contrast to when desynchronization is present when neurons do not exhibit extreme values for the firing frequency. Synchronization can also be characterized by neurons presenting either the highest or the lowest levels in the mean synaptic current. For the strong coupling, synchronous burst activities can occur for delays in the inhibitory conductivity. For approximately equal-length delays in the excitatory and inhibitory conductances, desynchronous spikes activities are identified for both weak and strong coupling regimes. Therefore, our results show that not only the conductance intensity, but also short delays in the inhibitory conductance are relevant to avoid abnormal neuronal synchronization.Peer Reviewe

    Spike-burst chimera states in an adaptive exponential integrate-and-fire neuronal network

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    We wish to acknowledge the support from Fundação Araucária, CNPq (Grant No. 150701/2018-7), CAPES, and FAPESP (Grant Nos. 2015/07311-7, 2018/03211-6, and 2017/18977-1).Peer reviewedPublisher PD

    Fractional dynamics and recurrence analysis in cancer model

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    In this work, we analyze the effects of fractional derivatives in the chaotic dynamics of a cancer model. We begin by studying the dynamics of a standard model, {\it i.e.}, with integer derivatives. We study the dynamical behavior by means of the bifurcation diagram, Lyapunov exponents, and recurrence quantification analysis (RQA), such as the recurrence rate (RR), the determinism (DET), and the recurrence time entropy (RTE). We find a high correlation coefficient between the Lyapunov exponents and RTE. Our simulations suggest that the tumor growth parameter (ρ1\rho_1) is associated with a chaotic regime. Our results suggest a high correlation between the largest Lyapunov exponents and RTE. After understanding the dynamics of the model in the standard formulation, we extend our results by considering fractional operators. We fix the parameters in the chaotic regime and investigate the effects of the fractional order. We demonstrate how fractional dynamics can be properly characterized using RQA measures, which offer the advantage of not requiring knowledge of the fractional Jacobian matrix. We find that the chaotic motion is suppressed as α\alpha decreases, and the system becomes periodic for α0.9966\alpha \lessapprox 0.9966. We observe limit cycles for α(0.9966,0.899)\alpha \in (0.9966,0.899) and fixed points for α<0.899\alpha<0.899. The fixed point is determined analytically for the considered parameters. Finally, we discover that these dynamics are separated by an exponential relationship between α\alpha and ρ1\rho_1. Also, the transition depends on a supper transient which obeys the same relationship

    Effects of drug resistance in the tumour-immune system with chemotherapy treatment

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    Acknowledgement This study was possible by partial financial support from the following Brazilian government agencies: Fundaao Araucaria, National Council for Scientific and Technological Development, Coordination for the Improvement of Higher Education Personnel, and Sao Paulo Research Foundation (2015/07311-7, 2017/18977- 1, 2018/03211-6, 2020/04624-2)Peer reviewedPostprin

    Macrossismicity associated with the Arraiolos earthquake of January 15, 2018 with M = 4.9 and possible implications in the geometry of the rupture

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    RESUMO: Na segunda quinzena de janeiro de 2018 realizou-se um estudo da macrossismicidade associada ao sismo de Arraiolos de dia 15 de janeiro. No presente trabalho descreve-se a metodologia usada na recolha de informação, o tratamento dos dados e a sua representação na forma de mapa de intensidades. A distribuição geográfica das intensidades mostra um alongamento da isossista de intensidade IV na direção N-S e no sentido sul. Este alongamento poderá estar relacionado com uma variação lateral da atenuação, ou com um efeito de sítio. Outra hipótese, menos provável, é que este padrão se deva ao efeito de diretividade originado por uma rutura unilateral com propagação de norte para sul, ao longo de um plano do mecanismo focal. Esta possibilidade, conjugada com evidências para a existência de estruturas ativas WNW-ESE descritas em trabalhos anteriores, levanta a hipótese do designado “cluster sísmico de Arraiolos” estar associado a uma interseção de falhas ativas.ABSTRACT: We performed a study about the macrossismicity associated to the Arraiolos (Portugal) earthquake, that occurred on January 15th, (M = 4.9), in order to construct a map of seismic intensities. The fieldwork took place in the second half of January, using the questionnaire available in the website of the Portuguese Institute of the Sea and the Atmosphere (IPMA). We provided the same questionnaire on the internet, and collected responses from many parts of the country. The results obtained allowed to construct a map of intensities showing a clear elongation of the intensities in a N-S direction. This orientation can be explained by the differences in the behaviour of seismic waves depending on the nature of the rocks or by a directivity effect associated with the rupture along a fault with this direction. On the one hand, an earthquake of magnitude 4.9 will hardly have the capacity to produce a directivity effect, however on the other hand the analysis of the Portuguese Geological Map seems to discard the first hypothesis. The IPMA provides on its website, a strike slip focal mechanism for this earthquake (E-W dextral and N-S sinistral). The conjugation of this focal mechanism with the distribution of intensities, seems to reinforce the hypothesis of rupture along an N-S fault plane. Similar focal mechanisms are known, associated with other earthquakes that occurred in this region, but previous works propose that they are related, not toN-Sruptures, buttoWNW-ESE structures present in the region, with geological and geomorphological evidence of recent tectonic activity. In this type of studies, there is always a factor ofsubjectivity inherent to the sensitivity of the people who were questioned, so these data are not sufficient to clearly affirm that the earthquake occurred associated with a N-S-trending fault. The combination of these data with the information published in previous works allows to consider the possibility that the "Arraiolos seismic cluster" corresponds to an intersection of active WNW-ESE and N-S strike slip faults. Assuming that there are alternating ruptures in both systems, temporary block occurs in the system that has been cut, leading to a local stress concentration. Though, a movement that in depth can be ductile, aseismic throughout most of the area of the faults, in the zone of intersection of the two systems the crust will have to respond necessarily as brittle, generating earthquakes and explaining the existence of this seismic cluster.info:eu-repo/semantics/publishedVersio

    Habitat filtering and inferred dispersal ability condition across-scale species turnover and rarity in Macaronesian island spider assemblages

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    Publisher Copyright: © 2021 The Authors. Journal of Biogeography published by John Wiley & Sons Ltd.Aim: Habitat diversity has been linked to the diversity and structure of island communities, however, little is known about patterns and processes within habitats. Here we aim to determine the contributions of habitat type and inferred dispersal frequency to the differences in taxonomic structure between assemblages in the same island habitat. Location: The Macaronesian archipelagos (Azores, Madeira, the Canary Islands and Cabo Verde). Taxon: Spiders (Araneae). Methods: We established forest and dry habitat sites (each with five plots) on two islands per archipelago. We collected spiders using standardised sampling protocols. We tested the differences in beta diversity separately for each habitat and for each inferred category of ballooning (an aerial dispersal strategy) frequency across geographic scales through nested non-parametric permutational multivariate analyses of variance. We then tested whether ballooning and habitat influenced heterogeneity in species composition (dispersion in beta diversity) in the two habitat types. We analysed the effects of habitat and ballooning on species abundance distribution (SAD) and rarity by fitting Gambin models and evaluating the contribution of ballooning categories to SAD. Results: Communities of the same archipelago and habitat were taxonomically more similar, and beta diversity increased with geographic scale, being greater in dry habitats. There was greater species replacement among assemblages in dry habitats than in forests, with greater differences for rare ballooners. There were no differences in SAD between habitats although dry habitat sites seemed to harbour more species with low abundances (rare species) than forests. Main conclusions: Habitat type does not only condition the differences between spider assemblages of the same habitat but also the scale at which they occur. These differences may be determined by the heterogeneity in the physical structure of each habitat as well as how much this structure facilitates aerial dispersal (ballooning), and should be considered in theories/hypotheses on island community assembly as well as in conservation strategies.Peer reviewe
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