A New Method for the Improvement of Data

Introduction – The use of the average analytical signal for the construction of curves by the least squares method (LSM) over the standard addition method (SAM) is widespread. It would be advantageous, however, to fi nd a way to avoid intermediary averages, which are known to be the cause of signifi cant increases in standard deviations (SD). Objective – To develop a protocol that uses all gathered data to create curves by LSM over SAM. To use Excel® for the estimation of y = mx + b and R2 rather than using LSM equations for the SD of m, x and b. Methodology – The level of lead (II) in the bark (cork) of Quercus suber Linnaeus was determined using diff erential pulse anodic stripping voltammetry (DPASV). Three current samples were taken for each of the four standard additions. These signals were combined for adjustment by LSM. The results were compared with those obtained after averaging the current for each addition, and the expression of uncertainty in the measurements determined. Results – The new method shows an expanded uncertainty of ± 0.3321 μg/g (nearly 1.42%). The diff erence between the results obtained by the new and the old method is 0.01 μg/g (23.41 and 23.40 μg/g). The limit of detection changed approximately from 4.8 to 4 μg/g and the relative SD approximately from 9 to 6%. Conclusion – The absence of intermediary averages in curves improved the determination of lead (II) in cork by DPASV. Estimation of SD only with LSM equations produced results that were signifi cantly worse. The changes are large enough to transform an apparently internally non-validated procedure (repeatability for precision) into an internally validated procedure

A teaching experiment on fraction division

This study is supported by FCT – Fundação para a Ciência e a Tecnologia, through a doctoral grant to Sofia Graça (SFRH/130343/2017)

Guimarães 2012 - Capital Europeia da Cultura. Memórias de um tempo feliz.

124-125 Jan.-Dez. 2014-2015, p. 37-40

Electroanalysis of Heavy Metals in the Cork of Quercus Suber

This will enable Pb(II) determination optimisation, regarding environmental aspects of the perpetuation of Quercus suber Montado (similar to Forest). It will also allow a more profound toxicological quality control of corks (barks). These two last referred aspects are very related ones, once accepted that the more advanced could the certification of the quality patterns of corks (barks) be, more will be the sustainability of Quercus suber ecosystem. Which we believe can be done, amongst other vectors, by studying such an important environmental issue as heavy metals. It is shown that Pb(II) quantification in the cork (bark) of Quercus suber tree (Cork Oak) is possible, using Differential Pulse Anodic Stripping Voltammetry (DPASV). The samples digestion was made in a mixture of H2O2 and HNO3 1:8, in a closed recipient at approximately 90 ºC. The measures were made in NaCl 0.1 M, using a Hanging Mercury Drop Electrode, a Glassy-Carbon Rod Counter Electrode, and an Ag/AgCl/KCl 3M reference electrode, after a 180 s deposition step. The results have shown the determination of a coherent stripping potential of -0.405 V (SD=0.0005 V), and a fine linear adjustment after the standard addition method (R2 = 0.997). They have also revealed the interest of further studies. The need to test other electroanalysis requisites was understood, and imposed by the proof of the complex nature of the matrix

THE IMPORTANCE OF THE CORK (BARK) OF QUERCUS SUBER IN THE

The recent absence of Lead element as catalyst in internal explosion motors, being an extremely important action for the stop of this environmental aggression, has no effect in the minimization of the harm this element does in the positions where its deposition now lays. The impact of the ubiquity of pollution, in this case Lead pollution, needs to have monitoring tools. The greatest of the tools one can have is the analysis of the content of a strong indicator. One that stands for a long time in one place, for which it is able to receive the marks of the analyte passage. Quercus suber (Cork Oak) tree is such a case. Having a life expectation ranging from 200 to 500 years (depending on the cork extraction intensity) and with a capability of regeneration of its cork coverture, it concentrates the amounts of Lead, with which it had contacted through its life, in successive layers, corresponding, the larger ones, to the high temperatures season, and the thinner ones to the low temperatures season. So, the analysis of the content of the element in a layer of cork with a given amount of years in the tree, will be a good estimator of how the content of Lead as evolved in the area. And a correct distribution of sampling trees will show much more about a greater area. The possibility of choosing years by choosing layers of cork, and the fact that the sampling will not harm the tree, if properly done, make this procedure a novel and powerful tool in the monitorization of the dispersion of heavy metals in areas populated by Quercus suber, as it is the case of big areas in Portugal, the great of the greatest in everything related with this tree, namely economically, and, in general, in the area of the Mediterranean basin. This paper announces how the electroanalytical determination of Pb(II) by Differential Pulse Anodic Stripping Voltammetry (DPASV), recently done in the Department of Chemistry of the University of Évora, already accepted for publication in Portugaliae Electrochimica Acta, has proven to allow a deeper insight into the previously discussed problematic

Algumas reflexões sobre estratégia naval portuguesa

info:eu-repo/semantics/publishedVersio

Impacto(s) da pandemia Covid-19 no burnout e indicadores de saúde mental

A síndrome respiratória aguda grave por Coronavírus 2 (Covid-19) é uma problemática pandémica muito atual, amplamente desconhecida e que convoca esforços e investimentos de múltiplas áreas científicas. A presente investigação, em Psicologia Clínica e da Saúde, pretende ser um contributo para uma melhor compreensão de alguns potenciais consequentes do medo e impacto(s) da Covid-19, mais concretamente, no âmbito da saúde mental. Assim, como objetivo geral deste trabalho temos o estudo do possível impacto da Covid-19 no Burnout e em indicadores específicos de saúde mental. Em termos de objetivos específicos visa-se: 1) Analisar a relação entre o medo face à covid-19 e indicadores de saúde mental; 2) Analisar a relação entre o medo face à covid-19 e o burnout; 3) Analisar a relação entre o impacto negativo da covid-19 e indicadores de saúde mental; 4) Analisar a relação entre o impacto negativo da covid-19 e o burnout; 5) Averiguar diferenças entre o medo face à Covid-19 em função de variáveis sociodemográficas; 6) Averiguar diferenças na variável impacto negativo da Covid-19 em função de variáveis sociodemográficas. Participaram no estudo 1508 pessoas, com idades compreendidas entre os 18 e os 74 anos, com uma média de idades de 33.68 anos e desvio padrão de 12.95, sendo 62.8% (n= 931) mulheres e 37% (n=548) homens. Os instrumentos utilizados foram: questionário sociodemográfico, o Brief Symptom Inventory 18 (BSI-18), escala de avaliação do impacto negativo da Covid-19 a escala de medo face à Covid-19, e ainda o Burnout Assessment Tool (BAT). Em resumo, os resultados obtidos mostraram que a Covid-19 tem um impacto significativo no burnout e na saúde mental das pessoas, pois foram encontradas associações positivas entre o medo e o impacto negativo da covid-19 no burnout e nos indicadores de saúde, quer de uma formal global, quer nas dimensões que constituem estes fenómenos. Também foram verificadas diferenças estatisticamente significativas no medo face à Covid-19 em função do género, e no impacto negativo da Covid-19 em função da escolaridade.The Coronavirus 2 Severe Acute Respiratory Syndrome (Covid-19) is a very current, largely unknown pandemic issue that gathers efforts and investments from multiple scientific areas. In Clinical and Health Psychology, the present research intends to contribute to a better understanding of some of the potential consequences of Covid-19, more specifically, in terms of its impact on mental health. Thus, the general objective of this work is to study the possible impact of Covid-19 on Burnout and specific mental health indicators. In terms of specific objectives we aim to: 1) Analyze the relationship between fear towards covid-19 and mental health indicators; 2) Analyze the relationship between fear towards covid-19 and burnout; 3) Analyze the relationship between the negative impact towards covid-19 and mental health indicators; 4) Analyze the relationship between the negative impact towards covid-19 and burnout; 5) Find differences between fear towards Covid-19 according to sociodemographic variables; 6) Find differences in the variable negative impact towards Covid-19 according to sociodemographic variables. The study included a total of 1508 participants, aged between 18 and 74 years old, with a mean age of 33.68 years and a standard deviation of 12.95, 62.8% (n=931) were women and 37% (n=548) were men. The instruments used were: a sociodemographic questionnaire, the Brief Symptom Inventory 18 (BSI-18), the scale of evaluation of the negative impact towards Covid-19, the scale of fear towards Covid-19, and also the Burnout Assessment Tool (BAT). In summary, the results obtained showed that Covid-19 has a significant impact on burnout and people's mental health, as positive associations were found between fear and negative impact compared to covid-19 on burnout and health indicators, either of a global formal or in the dimensions that constitute these phenomena. Statistically significant differences were also found in fear towards Covid-19 as a function of gender, and in the negative impact towards Covid-19 as a function of education

Drp1-mediated mitochondrial fission regulates calcium and F-actin dynamics during wound healing

This work was supported by national funds through FCT - Fundação para a Ciência e a Tecnologia, I.P., in the context of a program contract to L. Carvalho (4, 5 and 6 of article 23.º of D.L. no. 57/2016 of 29 August, as amended by Law no. 57/2017 of 19 July), PD/BD/106058/2015 to S. Ponte and PTDC/BIA-BID/29709/2017; the European Research Council (2007-StG-208631) and CONGENTO LISBOA-01-0145-FEDER-022170.Mitochondria adapt to cellular needs by changes in morphology through fusion and fission events, referred to as mitochondrial dynamics. Mitochondrial function and morphology are intimately connected and the dysregulation of mitochondrial dynamics is linked to several human diseases. In this work, we investigated the role of mitochondrial dynamics in wound healing in the Drosophila embryonic epidermis. Mutants for mitochondrial fusion and fission proteins fail to close their wounds, indicating that the regulation of mitochondrial dynamics is required for wound healing. By live-imaging, we found that loss of function of the mitochondrial fission protein Dynamin-related protein 1 (Drp1) compromises the increase of cytosolic and mitochondrial calcium upon wounding and leads to reduced ROS production and F-actin defects at the wound edge, culminating in wound healing impairment. Our results highlight a new role for mitochondrial dynamics in the regulation of calcium, ROS and F-actin during epithelial repair.publishersversionpublishe

Lipid peroxidation and antioxidant responses in zebrafish models after exposure to low doses of ionizing radiation

OBJECTIVES: The use of zebrafish – Danio rerio – has grown considerably, demonstrating the increasing interest to use this model in biomedical research, essentially because of the level of homology shared with the human genome, complemented by an easy and reasonably affordable practical side. This work aims to study the radiobiological effects of exposure to low doses of ionizing radiation