121 research outputs found

    A study of the ethical dilemmas experienced by school psychologists in Portugal

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    Published online: 06 Apr 2015This study examines the ethical dilemmas and difficulties encountered by Portuguese school psychologists. As part of a larger survey, participants were asked about ethical issues faced in daily practice and asked to describe ethical incidents. Of the 477 respondents, 274 reported 441 ethically troubling or challenging situations. Responses were coded into a six-category system based on the code of ethics of Portuguese psychologists. Most of the reported dilemmas concerned privacy and confidentiality principles (53%). Results are discussed in light of relevant literature and international findings. Implications for the development of the profession and future research are provided.This research was financially sponsored by the Portuguese Foundation for Science and Technology (Doctoral grant, SFRH/BD/78646/2011)

    Multi-syringe flow injection system for the determination of available phosphorus in soil samples

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    Considering the importance of monitoring the levels of nutrients present in soils and their availability to plants, an automatic methodology is proposed based on multi-syringe flow injection analysis (MSFIA) for the spectrophotometric determination of available phosphorus in soil extracts. This fully computerized flow technique allowed the development of a flow network where sample and reagents were intercalated and sent further towards the detection system. The colorimetric determination was based on the molybdenum blue method with ascorbic acid as reducing reagent and the Egner–Riehm method was applied to extract phosphorus from soil samples. A linear calibration curve was obtained between 0.75 and 15.0mgL-1. A determination frequency of 15 h-1 was achieved, with good repeatability for 12 consecutive injections of soil extracts (RSD<1.7%). The results obtained from 12 soil samples were statistically comparable to those attained by the usual batch method

    Multi-syringe flow injection system with in-line microwave digestion for the determination of phosphorus

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    A multi-syringe system for spectrophotometric determination of total phosphorus involving in-line digestion is proposed. Sample and digestion solution were dispensed and directed towards a digestion vessel located inside a domestic microwave oven (MWO) where sample digestion took place. Afterwards, the digested sample was merged with the necessary reagents for the colorimetric determination based on the molybdenum blue method. Several digestion conditions were studied regarding composition of digestion solution, digestion time and power set on theMWO. The system was applied to waste water samples and results shown a good agreement with the reference method. Repeatable results (R.S.D. < 2.41%) and determination frequency of 12 h−1 were obtained.info:eu-repo/semantics/acceptedVersio

    Sample introduction in multi-syringe flow injection systems: comparison between time-based and volume-based strategies

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    In multi-syringe flowinjection analysis (MSFIA), devices as selection, injection or commutation valves must be incorporated to the manifold to provide access to sample and standard solutions. Therefore, the definition of sample amount can be either volume or time-based. In the present work, four configurations for sample introduction (two for each approach) were tested in order to establish if the different strategies affect the analytical signal in MSFIA systems. The mean absorbance value from ten consecutive injections of a bromothymol blue solution obtained for the time-based strategy was lower than that provided by the volume-based approach as the exact volume delivered by each configuration was different from the “theoretical” volume. For time-based configurations, the exact volume delivered is 2–5% lower than the theoretical value while for volume-based configurations, the volume delivered was between 6 and 46% larger than the theoretical volume. Moreover, for time-based sampling, the order of steps in the analytical cycle was of utmost importance since any alteration in the flow direction affected the volume delivered in the subsequent step in the analytical cycle. The influence of the two sampling approaches was also evaluated in the MSFIA systems for the spectrophotometric determination of phenolic compounds and the potentiometric determination of chloride. There was no evidence that the use of either volume or time-based sampling would improve the analytical features of these determinations when real samples were tested.info:eu-repo/semantics/acceptedVersio

    Use of a polymer inclusion membrane and a chelating resin for the flow-based sequential determination of copper(II) and zinc(II) in natural waters and soil leachates

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    A bi-parametric sequential injection method for the determination of copper(II) and zinc(II) when present together in aqueous samples was developed. This was achieved by using a non-specific colorimetric reagent (4-(2-pyridylazo)resorcinol, PAR) together with two ion-exchange polymeric materials to discriminate between the two metal ions. A polymer inclusion membrane (PIM) and a chelating resin (Chelex 100) were the chosen materials to retain zinc(II) and copper(II), respectively. The influence of the flow system parameters, such as composition of the reagent solutions, flow rates and standard/sample volume, on the method sensitivity were studied. The interference of several common metal ions was assessed, and no significant interferences were observed (<10% signal deviation). The limits of detection were 3.1 and 5.6 µg L−1 for copper(II) and zinc(II), respectively; the dynamic working range was from 10 to 40 µg L−1 for both analytes. The newly developed sequential injection analysis (SIA) system was applied to natural waters and soil leachates, and the results were in agreement with those obtained with the reference procedure.info:eu-repo/semantics/publishedVersio

    Germany's 'coronavirus anomaly': Statistical evidence that early mass testing leads to low mortality rates

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    In this note, we present a statistical analysis of the mortality rates of COVID-19 for several selected European countries. We compare the countries' mortality rates with their respective number of tests as a function of the time since the first death. Our analysis shows that countries that either delayed mass testing, such as Italy, or have not fully adopted it, such as France and the UK, have had much higher mortality rates than Germany, which has adopted a policy of wide and early testing. Conversely, countries that have followed Germany's example, such as Portugal, have so far had comparatively low mortality rates

    Anti-inflammatory and antioxidant nanostructured cellulose membranes loaded with phenolic-based ionic liquids for cutaneous application

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    The utilization of natural compounds, such as phenolic acids and biopolymers, in the healthcare domain is gaining increasing attention. In this study, bacterial nanocellulose (BC) membranes were loaded with ionic liquids (ILs) based on phenolic acids. These ionic compounds, with improved solubility and bioavailability, were prepared by combining the cholinium cation with anions derived from caffeic, ellagic and gallic acids. The obtained BC-ILs membranes were homogeneous, conformable and their swelling ability agreed with the solubility of each IL. These membranes revealed a controlled ILs dissolution rate in the wet state and high antioxidant activity. In vitro assays performed with Raw 264.7 macrophages and HaCaT keratinocytes revealed that these novel BC-ILs membranes are non-cytotoxic and present relevant anti-inflammatory properties. Diffusion studies with Hanson vertical diffusion cells showed a prolonged release profile of the ILs from the BC membranes. Thus, this work, successfully demonstrates the potential of BC-ILs membranes for skin treatment.publishe

    Combate ao Coronavírus: a Janela para Intervenções não Farmacológicas é Estreita

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    In this technical note, we present a brief discussion of the main results reported in our paper “Modelling fatality curves of COVID-19 and the effectiveness of intervention strategies”, MedRxiv/2020/051557 (DOI:10.1101/2020.04.02.20051557). In that paper, we applied the Richards growth model (RGM) to describe the fatality curves of the COVID-19 disease for countries that were, up to April 1, 2020, near the end or in an intermediary phase of the outbreak, such as China, Italy, Spain, and Iran. We also analyzed data from Brazil, which was still in the early growth regime, and so we used an alternative model (the generalized growth model) that is more appropriate for the early stages of the epidemic. We also used the RGM to study the effectiveness of possible intervention strategies and, within this context, we derived an analytic formula for the efficiency of non-pharmaceutical intervention strategies. Our findings show that there is only a narrow window, after the onset of the epidemic, during which effective countermeasures can be taken. Here we present a brief overview of the results obtained in the aforementioned paper, but we use more recent data to update our analysis. For more details, we refer the reader to the original article.En esta nota técnica presentamos una breve discusión de los principales resultados de nuestro artículo "Modelado de curvas de mortalidad de COVID-19 y la efectividad de las estrategias de intervención", MedRxiv / 2020/051557 (DOI: 10.1101 / 2020.04.02.20051557). En este artículo, aplicamos el modelo de crecimiento de Richards para describir las curvas de mortalidad de COVID-19 para países que estaban, hasta el 4/1/2020, cerca del final o en la fase intermedia de la epidemia, como China, Italia, España e Irán. También analizamos datos de Brasil, aunque todavía estaba en las primeras etapas de la epidemia. Para este caso, utilizamos un modelo alternativo, el modelo de crecimiento generalizado, que es más apropiado para esa fase. También utilizamos el modelo de Richards para estudiar la efectividad de las posibles estrategias de intervención y, en este contexto, derivamos una fórmula analítica para la eficiencia de las estrategias de intervención no farmacológicas. Nuestros resultados muestran que solo hay una ventana estrecha, después de que comienza el brote, durante la cual se pueden tomar intervenciones no farmacológicas efectivas para contener la epidemia. En esta nota, también presentamos algunos resultados originales para las curvas de fatalidad de Italia y Brasil, actualizadas con datos hasta el 08/04/2020, además de una breve descripción general del trabajo mencionado anteriormente. Para más detalles, remitimos al lector al artículo original.Nesta nota técnica apresentamos uma breve discussão dos principais resultados do nosso artigo “Modelling fatality curves of COVID-19 and the effectiveness of intervention strategies”, MedRxiv/2020/051557 (DOI:10.1101/2020.04.02.20051557). Nesse artigo, aplicamos o modelo de crescimento de Richards para descrever as curvas de fatalidade da COVID-19 para países que estavam, até 01/04/2020, ou perto do fim ou na fase intermediária da epidemia, como a China, Itália, Espanha e Irã. Também analisamos dados do Brasil, embora ainda estivesse na fase inicial da epidemia, mas nesse caso usamos um modelo alternativo—o modelo de crescimento generalizado—que é mais apropriado para essa fase. Utilizamos ainda o modelo de Richards para estudar a eficácia de possíveis estratégias de intervenção e, nesse contexto, derivamos uma fórmula analítica para a eficiência das estratégias de intervenção não farmacológicas. Os nossos resultados mostram que existe apenas uma estreita janela, após o início do surto, durante a qual intervenções efetivas não farmacológicas podem ser tomadas para conter a epidemia. Nesta nota, apresentamos ainda alguns resultados originais para as curvas de fatalidade da Itália e do Brasil, atualizados com dados até 08/04/2020, além de uma breve descrição geral do trabalho acima mencionado. Para mais detalhes, remetemos o leitor para o artigo original
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