28 research outputs found

    Simultaneous determination of ketoacids and dicarbonyl compounds, key Maillard intermediates on the generation of aged wine aroma

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    The aim of thiswork was the simultaneous determination of both ketoacids and dicarbonyl compounds in wine.Todetect ketoacidcompoundsin wine,amethodbasedonthequinoxaline derivativesby the reaction with diaminobenzene, currently employed to detectα-dicarbonyl compounds, was developed. The quinoxaline derivatives were detected by RP-HPLC with UV detection, which allows the determination of the major dicarbonyl compounds in wine: glyoxal, methylglyoxal, diacetyl and pentane-2,6-dione, and the quinoxaline/quinoxalinol derivatives of α-keto-Îł-(methylthio)butyric acid and ÎČ-phenylpyruvic acid (intermediate ketoacid compounds of methional and phenylacetaldehyde) were simultaneously detected by a fluorescence detector. The identification was performed by comparison with standards and also by using LC-MSMS. The levels found in 15 wines analyzed (white wines,Madeira wines, and Port wines) diverge according to the type and the age of the wine. The ketoacid compounds ranged from 0.2 to 5.7 mg/L for α-keto-Îł-(methylthio)butyric acid and 0.1 to 9.6 mg/L for ÎČ-phenylpyruvic acid. The quantities observed for dicarbonyl compounds were similar to those already reported

    X-metabolomics : a software tool for dynamic mass spectroscopy automated signal processing

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    One of the major challenges of today's biotechnology is to be able to obtain the maximum of metabolic information for the holistic interpretation of biological systems. Herein we present a new computational application for gas-chromatography mass spectroscopy automated signal processing, named 'X-Metabolomics', that shows to be a potential framework for dynamic systems as fermentation processes interpretation by compounds and pathways identification and quantification and moreover for new metabolites discovery. Our GC-MS signal processing pipeline is implemented into an X-window interface using Tcl/Tk interface and based on R statistical programming environment for comprehensive statistical computing of results and access to 'Bioconductor' bioinformatics platform under Unix, Linux and MacOS. This approach focuses on the robustness of peak extraction algorithms for further identification, quantification and biological interpretation by multivariate analysis, evolving the following steps: i) peaks extraction; ii) supervised filtering; iii) identification of candidate fragments and removal of possible contaminants; iv) compounds identification/quantification; v) compounds expression and co-expression in time-course; and vi) sample classification and biological interpretation by multivariate analysis. 'X-Metabolomics' can be an useful tool in different fields such as pharmacology, genetics, living cells systems, promising to be innovative and very helpful for new drug discovery and new advances in dynamic systems understanding

    Plantar povoaçÔes no território: (re)construindo a urbanização da capitania do Piauí, 1697-1761

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    The PiauĂ­ provinceÂŽs urbanization has kept up with since late 17th century a complex process dealt among Portuguese Crown, the regal representatives, the network woven by the Casa da Torre and by the resident population in its countryside. What it was content of Rodelas countryside has begun to build with territorial identity since the foundation of first parish in 1697. Structuring itself discontinuously in time and space, the PiauĂ­ had reformed in 1758, year of creation of its autonomous government. And had became urban in 1761 when the king D. JosĂ© I and marquis of Pombal had framed by the royal letter written in June 19 a territory formed by six towns and one city. Thus, this paper purposes to reconstructing the PiauĂ­ province according to agents involved in the urbanization processes. It proposes to deconstructing CrownÂŽs polices by means towns strategically placed in territory aiming at control and "remedy" of routine injustices practiced in PiauĂ­ÂŽs hinterlands. The method of presenting this reconstruction draws on interconnection between text (manuscript documents) and image (maps and photography) which in their discourses have represented a PiauĂ­ as space of experiences apprehended as much in official dimension as inhabitantÂŽs everyday life.A urbanização da capitania do PiauĂ­ acompanhou, desde finais do sĂ©culo XVII, um complexo processo negociado entre a Coroa portuguesa, os representantes rĂ©gios, a rede clientelar urdida pela Casa da Torre e a população residente em seus sertĂ”es. O que antes era conteĂșdo dos sertĂ”es de Rodelas passou a construir-se como identidade territorial a partir da fundação da primeira freguesia, em 1697, dedicada a Nossa Senhora da VitĂłria. Estruturando-se descontinuamente no tempo e no espaço, o PiauĂ­ reforma-se em 1758, ano da autonomização do seu governo. E fez-se urbano em 1761, quando D. JosĂ© I e o marquĂȘs de Pombal equacionaram, por meio da carta rĂ©gia de 19 de junho, um territĂłrio formado por seis vilas e uma cidade. Nessa direção, o objetivo deste artigo consiste em reconstruir o processo de formação da capitania do PiauĂ­ segundo os agentes envolvidos na urbanização do territĂłrio. PropĂ”e-se descortinar as polĂ­ticas da Coroa por meio da oficialização de povoaçÔes estrategicamente locadas no territĂłrio visando o controle e o "remĂ©dio" das injustiças rotineiras do PiauĂ­. O mĂ©todo de apresentar essa reconstrução vale-se da interconexĂŁo entre texto (documentação manuscrita) e imagem (mapas e fotografias), que em suas entrelinhas representam um PiauĂ­ como espaço de experiĂȘncias sentidas tanto na dimensĂŁo oficial quanto no cotidiano dos seus moradores

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≀ 18 years: 69, 48, 23; 85%), older adults (≄ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

    O CĂĄlculo do Custo do capital nas Decisoes de Investimento em Activos Reais em Portugal: uma anĂĄlise empĂ­rica

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    We analyse the extent and depth with which the recommended theoretical concepts and procedures within the scope of cost of capital and investment analysis, are put in practise by professionals in medium and large businesses in Portugal. We present the conclusions, about a questionnaire that was carried out on the one thousand largest non-financial companies in Portugal. Among other conclusions, the results of 110 companies that have answered, made evident that about 72% have always or many times applied the cost of capital in the evaluation of new investment projects, and about 68% did not differentiate the discount rate used on their projects from the one used by the company; about 46% calculated the weighted average cost of the capital and half calculated the equity cost of capital, being that, of these, only 36% of the companies applied CAPM model either alone or together with the other methods. There is a predominant use of accounting return on equity (36%) and of the return on equity required by the company owners (22%). The main conclusion is that Portuguese companies make less use of the proceedings recommended by theorySe pretende analizar, de un punto de vista empírico, la extensión y la profundidad con que son aplicados, por los profesionales de las medianas y grandes empresas portuguesas, los conceptos y procedimientos teóricos recomendados para el cålculo del capital en el åmbito de las decisiones de inversión. Se describe la metodología utilizada en la encuesta dirigida a las mil mås importantes empresas no financieras de Portugal y se analizan los resultados obtenidos en una encuesta de 110 empresas (taza de respuesta.11%). Se destaca que: cerca de un 72 % de los respondientes aplicaban siempre o muchas veces el concepto de costo de capital en la evaluación de nuevos proyectos; cerca de un 68 % no diferenciaban la tasa de descuento utilizada en sus proyectos de la tasa de descuento de la empresa; cerca de un 46 % calculaban el costo medio ponderado del capital y que una mitad calculaba el costo del capital propio, siendo que, en estas, solamente un 36 % aplicaban el CAPM aislada o conjuntamente con otros métodos. Se verifica un predominio de aplicación del concepto de rendibilidad contable (36 %) y de la rendibilidad requerida por los propietarios de la empresa (22 %). Se destaca que el porcentaje de empresas portuguesas que aplican los conceptos y procedimientos teóricos es menor que el que se verifica en otros países donde se realizaron estudios similare

    Heterocyclic Acetals from Glycerol and Acetaldehyde in Port Wines: Evolution with Aging

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    In Port wine, isomers of glycerol and acetaldehyde acetals have been found at total contents ranging from 9.4 to 175.3 mg/L. During oxidative aging, the concentrations of the 5-hydroxy-2-methyl-1,3- dioxane and 4-hydroxymethyl-2-methyl-1,3-dioxolane isomers increased with time showing a linear correlation (r > 0.95). The flavor threshold for the mixture of the four isomers was evaluated in wine at 100 mg/L. Thus, it is expected that they contribute to “old Port wine” aroma in wines older than 30 years. Experiments with model solutions and wine clearly demonstrated that SO2 combines with acetaldehyde and blocks the acetalization reaction

    Extracção de Informação de Relatórios Médicos

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    <p>A utilização, cada vez mais frequente nos serviços de saúde nacionais, de sistemas de Registo Clínico Electrónico tem levado a um aumento significativo da Informação disponível em formato electrónico. Embora muita desta informação exista, actualmente, numa forma estruturada, uma parte significativa encontra-se sob a forma de texto livre não estruturado. A necessidade de processar e gerir estas grandes quantidades de texto tem motivado o recente interesse em aproximações semânticas. Este artigo descreve o trabalho desenvolvido no âmbito do projecto MedAlert para a criação de um corpus anotado semanticamente e no desenvolvimento de um sistema de extracção automática de informação capaz de identificar entidades clínicas relevantes, bem como os seus relacionamentos. Para tal, o MedAlert possui actualmente um corpus de cerca de 48 000 textos médicos relativos a episódios de internamento ocorridos no Hospital Infante D. Pedro, em Aveiro. Um subconjunto do corpus foi seleccionado para a criação das directivas de anotação e anotação semântica manual e automática. O sistema de reconhecimento de entidades mencionadas REMMA foi usado numa primeira avaliação. Os primeiros resultados são apresentados indicando a necessidade de desenvolver directivas precisas para a anotação de textos médicos, de modo a melhorar a concordância entre anotadores.</p&gt

    Non-targeted and targeted analysis of wild toxic and edible mushrooms using gas chromatography-ion trap mass spectrometry

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    Mushrooms are known all over the world both due to the remarkable gastronomic value of some species and for severe intoxications mediated by other species that are frequently difficult to distinguish from the edible ones, by the common user. Therefore, it is important to develop strategies to discover molecules that can identify mushroom species. In the present work, two GC–MS methodologies were applied in the chemical characterization of 22 mushroom species (12 edible, 3 toxic and 7 potentially toxic) – a multi-target procedure to simultaneously determine amino acids (AA), fatty acids (FA) and sterols by previous derivatization procedure with MSTFA, and a Head Space-Solid Phase Microextraction method to determine volatiles. For both methods, two approaches to data analysis were used: (I) targeted analysis, to identify and quantify AA, FA sterols and volatiles; (II) untargeted analysis, including Principal Component Analysis and Partial Least Square Discriminant Analysis, in order to identify metabolites/metabolite pattern with potential species identification and/or differentiation. Multi-target experiment allowed the identification and quantification of twenty one primary metabolites (9 AA, 11 FA and 1 sterol). Furthermore, through untargeted data analysis, it was possible to identify a 5- carbon sugar alcohol structure molecule, which was tentatively identified as xylitol or adonitol, with potential to be a species-marker of the edible Suillus bovinus mushrooms. Volatile profiling studies resulted in the identification of the main volatiles in mushrooms. Untargeted analysis allowed the identification of 6 molecules that can be species- or genus-specific: one secondary metabolite specific to the edible species Lycoperdon perlatum, an ester of hexanoic acid, tentatively identified as allyl or vinyl caproate; and five other secondary metabolites, whose identification was not achieved, which were only detected in Lactarius aurantiacus specimens (edibility/toxicity unknown)

    Riverine and marine ecotypes of Sotalia dolphins are different species

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    The current taxonomic status of Sotalia species is uncertain. The genus once comprised five species, but in the twentieth century they were grouped into two (riverine Sotalia fluviatilis and marine Sotalia guianensis) that later were further lumped into a single species (S. fluviatilis), with marine and riverine ecotypes. This uncertainty hampers the assessment of potential impacts on populations and the design of effective conservation measures. We used mitochondrial DNA control region and cytochrome b sequence data to investigate the specific status of S. fluviatilis ecotypes and their population structure along the Brazilian coast. Nested-clade (NCA), phylogenetic analyses and analysis of molecular variance of control region sequences showed that marine and riverine ecotypes form very divergent monophyletic groups (2.5% sequence divergence; 75% of total molecular variance found between them), which have been evolving independently since an old allopatric fragmentation event. This result is also corroborated by cytochrome b sequence data, for which marine and riverine specimens are fixed for haplotypes that differ by 28 (out of 1,140) nucleotides. According to various species definition methods, we conclude that marine and riverine Sotalia are different species. Based on priority criteria, we recommend the revalidation of Sotalia guianensis (Van Bénéden 1864) for the marine animals, while riverine dolphins should retain the species name Sotalia fluviatilis (Gervais 1853), thus becoming the first exclusively riverine delphinid. The populations of S. guianensis show a strong subdivision (ΊST=0.628) along the Brazilian coast, with at least three evolutionarily significant units: north, northeastern and south/southeastern. © Springer-Verlag 2005
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