166 research outputs found
Phenolic acids determination by HPLC-DAD-ESI/MS in sixteen different portuguese wild mushrooms species
Analysis of phenolic compounds in sixteen Portuguese wild mushrooms species has been carried out by
high-performance liquid chromatography coupled to photodiode array detector and mass spectrometer
(HPLC–DAD–ESI/MS). No flavonoids were detected in the analysed samples, but diverse phenolic acids
namely protocatechuic, p-hydroxybenzoic and p-coumaric acids, and two vanillic acid isomers were
found and quantified. A related non-phenolic compound, cinnamic acid, was also detected in some samples,
being the only compound found in Cantharellus cibarius (14.97 mg/kg, dry matter), Lycoperdon perlatum
(14.36 mg/kg) and Macrolepiota procera (21.53 mg/kg). p-Hydroxybenzoic acid was found in the
majority of the samples, being the most abundant compound in Agaricus silvicola (238.7 mg/kg). Ramaria
botrytis showed the highest phenolic acids concentration (356.7 mg/kg) due to the significant contribution
of protocatechuic acid (342.7 mg/kg)
Comprehensive Assessment of TERT mRNA Expression across a Large Cohort of Benign and Malignant Thyroid Tumours
The presence of TERT promoter (TERTp) mutations in thyroid cancer have been associated with worse prognosis features, whereas the extent and meaning of the expression and activation of TERT in thyroid tumours is still largely unknown. We analysed frozen samples from a series of benign and malignant thyroid tumours, displaying non-aggressive features and low mutational burden in order to evaluate the presence of TERTp mutations and TERT mRNA expression in these settings. In this series, TERTp mutations were found in 2%, only in malignant cases, in larger cancers, and from older patients. TERT mRNA expression was detected in both benign and malignant tumours, with increased frequencies in the malignant tumours with aggressive histotypes, larger tumours, and from older patients. In benign tumours, TERT mRNA expression was found in 17% of the follicular thyroid adenoma (FTA) with increased levels of expression in smaller tumours and associated with the presence of thyroiditis. TERTp mutations and TERT mRNA expression are correlated with worse prognosis features in malignant thyroid tumours, whereas TERT mRNA expression in the benign tumours is associated with the presence of thyroiditis.info:eu-repo/semantics/publishedVersio
Optimization of the determination of tocopherols in Agaricus sp. edible mushrooms by a normal phase liquid chromatographic method
Individual tocopherol profile of five Agaricus mushroom species, widely consumed in Portugal, was obtained by a normal-phase high-performance liquid chromatography (NP-HPLC). It was used a simple
solid–liquid extraction procedure without saponification step and the chromatographic separation was
achieved using a YMC-Pack Polyamine II column using an isocratic elution with hexane/ethyl acetate
(70:30, v/v) at a flow rate of 1.0 mL/min. The effluent was monitored by a fluorescence detector. All
the compounds were separated in a period of time of 30 min. The method proved to be sensitive, reproducible
and accurate, allowing the determination of tocopherols
A argumentação nos editoriais de jornais paraibanos do século XIX e século XX: aspectos linguÃsticos e contextuais
Este trabalho tem como objetivo contemplar o estudo da história do uso da LÃngua Portuguesa do Brasil presente no Estado da ParaÃba, nos séculos XIX e XX. Detivemo-nos precisamente nos aspectos sócio-históricos e linguÃsticos encontrados nos textos editoriais de jornais. Para a sua concretização, tivemos como principal base teórica o modelo das Tradições Discursivas (KABATEK, 2005), que colabora para que possamos acompanhar a evolução e transformação dos gêneros, e a teoria da argumentação (DUCROT, 1988), a qual vê o fenômeno da argumentação presente na linguagem, cujas marcas podem ser visualizadas por meio dos operadores e modalizadores discursivos. Servimo-nos de banco de textos da Hemeroteca Digital Brasileira e de acervos locais como o Instituto Histórico da ParaÃba e Casa Fundação José Américo- PB. Percebemos neste estudo o quanto o texto editorial é argumentativo e que os modalizadores favorecem essa ação. Ao observar os modalizadores, vimos qual a posição do jornal perante o fato ou assunto tratado, bem como os editores querem induzir a uma determinada opinião. Os modalizadores encontrados com mais frequência nos editoriais analisados foram os afetivos (avaliativos), deônticos e epistêmicos
Multivariate and multiscale complexity of long-range correlated cardiovascular and respiratory variability series
Assessing the dynamical complexity of biological time series represents an important topic with potential applications ranging from the characterization of physiological states and pathological conditions to the calculation of diagnostic parameters. In particular, cardiovascular time series exhibit a variability produced by different physiological control mechanisms coupled with each other, which take into account several variables and operate across multiple time scales that result in the coexistence of short term dynamics and long-range correlations. The most widely employed technique to evaluate the dynamical complexity of a time series at different time scales, the so-called multiscale entropy (MSE), has been proven to be unsuitable in the presence of short multivariate time series to be analyzed at long time scales. This work aims at overcoming these issues via the introduction of a new method for the assessment of the multiscale complexity of multivariate time series. The method first exploits vector autoregressive fractionally integrated (VARFI) models to yield a linear parametric representation of vector stochastic processes characterized by short- and long-range correlations. Then, it provides an analytical formulation, within the theory of state-space models, of how the VARFI parameters change when the processes are observed across multiple time scales, which is finally exploited to derive MSE measures relevant to the overall multivariate process or to one constituent scalar process. The proposed approach is applied on cardiovascular and respiratory time series to assess the complexity of the heart period, systolic arterial pressure and respiration variability measured in a group of healthy subjects during conditions of postural and mental stress. Our results document that the proposed methodology can detect physiologically meaningful multiscale patterns of complexity documented previously, but can also capture significant variations in complexity which cannot be observed using standard methods that do not take into account long-range correlations.publishe
Assessing Transfer Entropy in cardiovascular and respiratory time series: A VARFI approach
In the study of complex biomedical systems represented by multivariate stochastic processes, such as the cardiovascular and respiratory systems, an issue of great relevance is the description of the system dynamics spanning multiple temporal scales. Recently, the quantification of multiscale complexity based on linear parametric models, incorporating autoregressive coefficients and fractional integration, encompassing short term dynamics and long-range correlations, was extended to multivariate time series. Within this Vector AutoRegressive Fractionally Integrated (VARFI)
framework formalized for Gaussian processes, in this work we propose to estimate the Transfer Entropy, or equivalently Granger Causality, in the cardiovascular and respiratory systems. This allows to quantify the information flow and assess directed interactions accounting for the simultaneous presence of short-term dynamics and long-range correlations. The proposed approach is first tested on simulations of benchmark VARFI processes where the transfer entropy could be computed from the known model parameters. Then, it is applied to experimental data consisting of heart period, systolic arterial pressure and respiration time series measured in healthy subjects monitored at rest and during mental and postural stress. Both simulations and real data analysis revealed that the proposed method
highlights the dependence of the information transfer on the balance between short-term and longrange correlations in coupled dynamical systems
Relação entre a qualidade de vida geral e especÃfica na neuropatia diabética com o sexo, comorbilidades e adesão terapêutica
[resumo][abstract
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