1,898 research outputs found

    Evaluation of knowledge of a sample of the Portuguese population on bisphenol A

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    O bisfenol A (BPA) é um composto orgânico, de origem industrial, com atividade estrogénica. A sua principal utilização encontra-se na produção de plásticos policarbonatos e resinas epóxi, aplicados a embalagens alimentares e produtos médicos. Devido aos perigos associados à ingestão repetida e a longo prazo deste xenoestrogénio, é importante avaliar a perceção e o conhecimento da população portuguesa acerca do BPA e dos seus efeitos para a saúde. Deste modo, foi elaborado um questionário sobre este composto e aplicado a uma amostra da população portuguesa. A amostra foi constituída por 249 indivíduos de diversas zonas do país, pertencentes a diversas faixas etárias e com vários níveis de escolaridade. O questionário compilou questões que permitem reunir dados socioeconómicos e obter informação acerca do conhecimento dos inquiridos sobre este composto químico. Os resultados obtidos mostram que 64% dos inquiridos nunca ouviram falar do BPA. Apesar de 92% dos inquiridos (dos que conheciam o BPA) terem conhecimento que a exposição a este químico produz efeitos negativos para a sua saúde, e que estes, estão maioritariamente associados à utilização de materiais plásticos em contacto com alimentos, 50% mostram desconhecimento de quais os tipos de riscos a que estão sujeitos. Concluiu-se que nesta amostra da população portuguesa o conhecimento sobre o bisfenol A (BPA) é escasso, e que a maioria dos inquiridos não conhece o composto.Bisphenol A (BPA) is an organic compound, of industrial origin, with estrogenic activity. Its main use is in the production of plastic polycarbonates and epoxy resins, applied to food packaging and medical products. Due to the dangers associated with repeated and long-term ingestion of this xenoestrogen, it is impor tant to assess the perception and knowledge of the Por tuguese population about BPA and its health ef fects. Thus, a questionnaire was elaborated on this compound and applied to a sample of the Por tuguese population. The sample was made up of 249 individuals from dif ferent par ts of the countr y, belonging to dif ferent age groups and with dif ferent education levels. The questionnaire compiled questions that allow us to gather socioeconomic data and obtain information about the knowledge of the par ticipants about this chemical. The results show that 64% of the par ticipants never heard of BPA. Although 92% of the respondents (from those who knew BPA) knew that exposure to this chemical agent had negative ef fects on their health and that these were mostly associated with the use of plastic materials in contact with food, 50% showed lack of knowledge of the types of risks to which they are subjected. It was concluded that among this sample of the Por tuguese population the knowledge about BPA is scarce, and the majority do not know the compound.Trabalho realizado no âmbito do projeto “Development of methodologies for the evaluation of polymeric food packaging components and determination of their structural and mechanical properties” (2016DAN 1289) do Instituto Nacional de Saúde Doutor Ricardo Jorge. A autora MFV agradece o financiamento da FCT, através do IDMEC, LAETA, projeto UID/EMS/50022/2019.info:eu-repo/semantics/publishedVersio

    Mead production: selection and characterization assays of Saccharomyces cerevisiae strains

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    http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=10&SID=V12mKh9k9n8jHN@CK7o&page=1&doc=1&colname=WOSMead is a traditional drink, which results from the alcoholic fermentation of diluted honey carried out by yeasts. However, when it is produced in a homemade way, mead producers find several problems, namely, the lack of uniformity in the final product, delayed and arrested fermentations, and the production of “off-flavours” by the yeasts. These problems are usually associated with the inability of yeast strains to respond and adapt to unfavourable and stressful growth conditions. The main objectives of this work were to evaluate the capacity of Saccharomyces cerevisiae strains, isolated from honey of the Trás-os-Montes (Northeast Portugal), to produce mead. Five strains from honey, as well as one laboratory strain and one commercial wine strain, were evaluated in terms of their fermentation performance under ethanol, sulphur dioxide and osmotic stress. All the strains showed similar behaviour in these conditions. Two yeasts strains isolated from honey and the commercial wine strain were further tested for mead production, using two different honeys (a dark and a light honey), enriched with two supplements (one commercial and one developed by the research team), as fermentation media. The results obtained in this work show that S. cerevisiae strains isolated from honey, are appropriate for mead production. However it is of extreme importance to take into account the characteristics of the honey, and supplements used in the fermentation medium formulation, in order to achieve the best results in mead production

    Mead production: selection and characterization assays of Saccharomyces cerevisiae

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    Mead is a traditional alcoholic drink which results from the fermentation of diluted honey. Yeasts used in mead production are, usually, wine Saccharomyces cerevisiae strains. Most of these yeasts are not adapted to the conditions of mead production namely, high sugar levels, low pH values and reduced nitrogen concentrations. The inability of yeast strains to respond and adapt to unfavorable stressful growth conditions, leads to several problems, such as lack of uniformity of the final product, delays and “pouts” fermentations, as well as the production of off-flavors by the yeasts. Therefore, it is necessary to find yeast strains more suitable for mead production

    Electrophysiological answer to a checkerboard stimulus: A pilot study

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    Electroencephalography is a clinical signal that reveals the brain's electrical activity. In this category, the Visual Evoked Potentials (VEP) is one of the most frequent measures, especially when it is necessary to assess the maturity and function of the central visual system. The Electrodermal Activity (EDA) data gives information about skin conductance, and it is used to evaluate autonomic sympathetic reactions, often related to neuropsychological states. It could be used with all ages and in young subjects with healthy development or clinical practice with children with atypical development. In this paper, we propose an experimental setup based on checkerboard stimuli to assess the evolution of visual system development of preterm infants. This experimental protocol was applied to two female preterm born infants of 4 and 6 months of corrected age. The preliminary findings show that, as expected, the P100 latencies and amplitude are still different from those expected for adults and older children. However, the older infant presents results more similar to adults, corresponding to having a more mature visual system. Concerning EDA, it was observed that the older infant presents more responses to the stimulus, a higher level of skin conductance, and a shorter latency time than the younger infant, which is congruent with what is expected, given the maturation of the nervous system. The methodology used in this pilot application and the algorithm defined seem adequate to use in a longitudinal study to follow the evolution of preterm and term infants

    Comparison between topical use of ketotifen and olopatadine in the treatment of allergic conjunctivitis

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    Purpose: To evaluate and compare the efficacy and tolerance to the topical use of 0.05% ketotifen fumarate and 0.1% olopatadine hydrochloride in the treatment of patients with allergic conjunctivitis. Methods: A masked, randomized clinical study was performed in order to compare the efficacy, safety and side effects of the use of 0.05% ketotifen fumarate and 0.1% olopatadine hydrochloride ophthalmic solutions for the alleviation of symptoms and signs in patients with allergic conjunctivitis. Thirty-four patients, fulfilling the inclusion criteria of the protocol were divided into two groups and received a flask with the masked drug, instilling one drop twice daily in each eye for 30 days. Signs and symptoms of these patients were evaluated on a visit before treatment and on five visits during the treatment (days 1, 2, 7, 14 and 30). Results: Severity of allergic conjunctivitis was the same in both studied groups. Both ketotifen and olopatadine were equivalent and efficient regarding decrease in itching, burning and lacrimation symptoms. Bulbar conjunctival hyperemia was attenuated in both groups. Evaluation of adverse reactions showed the occurrence of burning on administration of both drugs and ketotifen led to occurrence of itching. No hypersensitivity reaction to the studied drugs was observed. Conclusions: This study evidences that 0.05% ketotifen fumarate and 0.1% olopatadine hydrochloride ophthalmic solutions, when instilled twice daily for 30 days, were efficient and safe regarding alleviation of the main symptoms and signs of allergic conjunctivitis.Objetivo: Avaliar e comparar a eficácia e tolerância do uso tópico do fumarato de cetotifeno a 0,05% e cloridrato de olopatadina a 0,1% no tratamento de pacientes com conjuntivite alérgica. Método: Foi realizado estudo clínico mascarado, randomizado comparando a eficácia, segurança e os efeitos colaterais com o uso da solução oftálmica de fumarato de cetotifeno a 0,05% e cloridrato de olopatadina a 0,1% no alívio dos sintomas e sinais em pacientes com conjuntivite alérgica. Trinta e quatro pacientes obedecendo aos critérios de inclusão do protocolo receberam um frasco com a droga mascarada e instilaram uma gota duas vezes por dia em cada olho durante 30 dias. Os sintomas e sinais dos pacientes foram avaliados em uma visita pré-tratamento e cinco com tratamento (1º dia, 2º dia, 7º dia, 14º dia e 30º dia). Resultados: A gravidade da conjuntivite alérgica foi semelhante nos dois grupos do estudo. Tanto cetotifeno como a olopatadina foram equivalentes e eficazes na diminuição dos sintomas de prurido, ardor e lacrimejamento. Quanto aos sinais, a hiperemia em conjuntiva bulbar foi atenuada nos dois grupos. Na avaliação das reações adversas observou-se ardor após a administração de ambos colírios e a ocorrência de prurido no grupo do cetotifeno. Não foi observada nenhuma reação de hipersensibilidade das drogas estudadas. Conclusões: Este estudo evidencia que a solução oftálmica de fumarato de cetotifeno a 0,05% e o cloridrato de olopatadina a 0,1% quando instilados duas vezes ao dia durante 30 dias, são eficazes e seguros no alívio dos principais sintomas das conjuntivites alérgicas.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de OftalmologiaUNIFESP, EPM, Depto. de OftalmologiaSciEL

    Does Eating Slowly Influence Appetite and Energy Intake when Water Intake is Controlled?

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    Background: Slow eating has been associated with enhanced satiation, but also with increased water intake. Therefore, the role of water ingestion in regard to eating rate needs to be discerned. This study examined the influence of eating rate on appetite regulation and energy intake when water intake is controlled. Methods: In a randomized design, slow and fast eating rates were compared on two occasions, in 30 women (22.7±1.2y; BMI=22.4±0.4kg/m2) who consumed an ad libitum mixed-macronutrient lunch with water (300 mL). Satiation was examined as the main outcome by measuring energy intake during meals. At designated times, subjects rated hunger, satiety, desire-to-eat, thirst, and meal palatability on visual analogue scales. Paired t-tests were used to compare hypothesis-driven outcomes. Appetite ratings were compared across time points and conditions by repeated measures analysis of variance (ANOVA) using a within-subject model. Results: Energy intake and appetite ratings did not differ between conditions at meal completion. However, subjects rated less hunger and tended to rate lower desire-to-eat and greater satiety at 1 hour following the slow condition. Conclusions: Results tend to support a role of slow eating on decreased hunger and higher inter-meal satiety when water intake is controlled. However, the lack of significant differences in energy intake under these conditions indicates that water intake may account for the effects of eating rate on appetite regulation

    Acetylcholinesterase Choline-Based Ionic Liquid Inhibitors: In Vitro and in Silico Molecular Docking Studies

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    COMPETE Programme: SAICTPAC/0019/2015 IF/00780/2015 Project no. 022161Monocationic and dicationic cholinium ionic liquids (ILs) were synthesized and evaluated as acetylcholinesterase (AChE) inhibitors with in vitro and in silico models, and their cytotoxicity was assessed using human cell lines from skin (CRL-1502) and colon cancer (CaCo-2). The ILs with a longer alkyl chain were stronger AChE inhibitors, the dicationic ILs (DILs) being more active than the monocationic ILs. The best result was obtained for [N1,1,12,2(OH)]2Br2 at a concentration of 0.18 ÎĽM by reducing half enzyme activity without affecting the viability of tested cell lines. A saturation-transfer difference NMR (STD-NMR) binding study was carried out, demonstrating that [N1,1,12,2(OH)]2Br2 binds to AChE. STD-NMR competition binding experiments, using galanthamine as a reference ligand, clearly highlight that the IL displaces galanthamine in the AChE binding site pinpointing [N1,1,12,2(OH)]2Br2 inside the deep gorge of AChE. In order to obtain a three-dimensional (3D) view of the molecular recognition process, in silico molecular docking studies on the active site of AChE were carried out. The proposed 3D model of the AChE/DIL complex is in agreement with the STD-derived epitope mapping, which explains the competition with galanthamine and unveils key interactions in both peripheral and catalytic sites of AChE. These interactions seem essential to govern the recognition of DILs by the AChE enzyme. Our study provides a structural and functional platform that can be used for the rational design of choline-based ILs as potent AChE inhibitors.publishersversionpublishe

    How does dilution affect the conductivity, the propensity to aggregate and the biological activity of enzymes?

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    The current theories do not provide a convincing explanation for many of the protein' manifestations in solution. Therefore, to shed some light on this critical question, the present work analyzed the effect of dilution on the ability of proteins to catalyze chemical reactions, the so-called biological activity. As models enzymes, laccase from Trametes versicolor and chicken egg white lysozyme were used. The results show that the enzymes' specific biological activity increases on dilution. Three explanations for the intriguing observation were advanced and submitted to experimental scrutiny. Amongst the three hypotheses, only one was corroborated by experiments. According to this explanation, when dissolved in water, proteins reveal two populations: one biologically active whose relative occurrence increases on dilution and another which is not active and whose molecular proportion varies in the opposite direction. Therefore, the reported experimental facts strongly support the chemical behaviour of the proteins in the solution. According to the herein-advocated concepts, they could undergo a dissociation process similar to that found in electrolyte chemistry.publishe
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