The periodic table: contest and exhibition

The systemization and organization of ideas and concepts is an integral part of science. In chemistry, the organization of the periodic table of the chemical elements in the 1860s was one of the greatest scientific breakthroughs ever made and in fact during the 20th century it became a universally recognized scientific icon (1). The periodic table is the fundamental classificatory scheme of the elements and summarizes the realm of chemistry (2). Simply knowing the position of an element in the periodic table tells us about its properties and is usually enough to predict how the element will behave in a wide variety of different situations or reactions (1). Based on this potential mine of information, it is possible to make reliable predictions of the properties of the compounds that each element forms. Nowadays, the concept of the periodic table is starting to interact with other sciences and reports of periodic tables of amino acids (3), genetic codes (4), protein structures (5), and biology (6) can be found in the specialized literature. Symbiosis between science and art, for example, “The Periodic Table of The Elephants” (7), can also be seen. To appeal to a better understanding of the periodic table, the Instituto Superior de Engenharia do Instituto Politécnico do Porto and the Centro de Química da Universidade do Porto promoted a contest and exhibit with the goal of stimulating a wide and heterogeneous audience, ranging from young children and their parents to graduate students from several disciplines, to explore the nature of this icon. Imaginative educational activities such as contests (8–10), games (11, 12), and puzzles (13–15) provided a way to communicate with the general public with the goal of attracting students to science. This also constituted an interesting, informative, and entertaining alternative to non-interactive lectures. Simultaneously, artistic creativity was combined with scientific knowledge.

Ecotoxicity tests using the green algae chlorella vulgaris — a useful tool in hazardous effluents management

The treatment efficiency of laboratory wastewaters was evaluated and ecotoxicity tests with Chlorella vulgaris were performed on them to assess the safety of their environmental discharge. For chemical oxygen demand wastewaters, chromium (VI), mercury (II) and silver were efficiently removedby chemical treatments.Areduction of ecotoxicitywas achieved; nevertheless, an EC50 (effective concentration that causes a 50% inhibition in the algae growth) of 1.5% (v/v) indicated still high level of ecotoxicity. For chloride determination wastewaters, an efficient reduction of chromium and silver was achieved after treatment. Regarding the reduction of ecotoxicity observed, EC50 increased from 0.059% to 0.5%, only a 0.02% concentration in the aquatic environment would guarantee no effects. Wastewaters containing phenanthroline/iron (II) complex were treated by chemical oxidation. Treatmentwas satisfactory concerning chemical parameters, although an increase in ecotoxicitywas observed (EC50 reduced from 0.31% to 0.21%). The wastes from the kinetic study of persulphate and iodide reaction were treated with sodium bisulphite until colour was removed. Although they did not reveal significant ecotoxicity, only over 1% of the untreated waste produced observable effects over algae. Therefore, ecotoxicity tests could be considered a useful tool not only in laboratory effluents treatment, as shown, but also in hazardous wastewaters management.

Flavoured versus natural waters: macromineral (Ca, Mg, K, Na) and micromineral (Fe, Cu, Zn) contents

Macro (Ca, Mg, K, Na) and micromineral (Fe, Zn, Cu) composition of 39 waters was analysed. Determinations were made by atomic flame spectrophotometry for macrominerals and electrothermic atomisation in graphite furnace for microminerals. Mineral contents of still or sparkling natural waters (without flavours) changed from brand to brand. Mann–Whitney test was used to search for significant differences between flavoured and natural waters. For that, the concentration of each mineral was compared to the presence of flavours, preservatives, acidifying agents, fruit juice and/or sweeteners, according to the labelled composition. The statistical study demonstrated that flavoured waters generally have increased contents of K, Na, Fe and Cu. The added preservatives also led to significant differences in the mineral composition. Acidifying agents and fruit juice can also be correlated to the increase of Mg, K, Na, Fe and Cu. Sweeteners do not provide any significant difference in Ca, Mg, Fe and Zn contents.

Use of solvent extraction to remediate soils contaminated with hydrocarbons

The main objective of this research is to exploit the possibility of using an ex situ solvent extraction technique for the remediation of soils contaminated with semi-volatile petroleum hydrocarbons. The composition of the organic phase was chosen in order to form a single phase mixture with an aqueous phase and simultaneously not being disturbed (forming stable emulsions) by the soil particles hauling the contaminants. It should also permit a regeneration of the organic solvent phase. As first, we studied the miscibility domain of the chosen ternary systems constituted by ethyl acetate–acetone–water. This system proved to satisfy the previous requirements allowing for the formation of a single liquid phase mixture within a large spectrum of compositions, and also allowing for an intimate contact with the soil. Contaminants in the diesel range within different functional groups were selected: xylene, naphthalene and hexadecane. The analytical control was done by gas chromatography with FID detector. The kinetics of the extractions proved to be fast, leading to equilibrium after 10 min. The effect of the solid–liquid ratio on the extraction efficiency was studied. Lower S/L ratios (1:8, w/v) proved to be more efficient, reaching recoveries in the order of 95%. The option of extraction in multiple contacts did not improve the recovery in relation to a single contact. The solvent can be regenerated by distillation with a loss around 10%. The contaminants are not evaporated and they remain in the non-volatile phase. The global results show that the ex situ solvent extraction is technically a feasible option for the remediation of semi-volatile aromatic, polyaromatic and linear hydrocarbons.

Heterogeneous kinetics of the reduction of chromium (VI) by elemental iron

Zero valent iron (ZVI) has been extensively used as a reactive medium for the reduction of Cr(VI) to Cr(III) in reactive permeable barriers. The kinetic rate depends strongly on the superficial oxidation of the iron particles used and the preliminary washing of ZVI increases the rate. The reaction has been primarily modelled using a pseudo-first-order kinetics which is inappropriate for a heterogeneous reaction. We assumed a shrinking particle type model where the kinetic rate is proportional to the available iron surface area, to the initial volume of solution and to the chromium concentration raised to a power ˛ which is the order of the chemical reaction occurring at surface. We assumed α= 2/3 based on the likeness to the shrinking particle models with spherical symmetry. Kinetics studies were performed in order to evaluate the suitability of this approach. The influence of the following parameters was experimentally studied: initial available surface area, chromium concentration, temperature and pH. The assumed order for the reaction was confirmed. In addition, the rate constant was calculated from data obtained in different operating conditions. Digital pictures of iron balls were periodically taken and the image treatment allowed for establishing the time evolution of their size distribution.

O perfil do utente com Acidente Vascular Cerebral

A principal causa de morte e incapacidade em Portugal deve-se a Acidentes Vasculares Cerebrais (AVC). Assim, este trabalho de investigação pretende identificar e quantificar quais os fatores que contribuem para a ocorrência de um AVC (por tipo e com sequelas), duração do internamento e potenciais soluções de encaminhamento terapêutico para o doente após a ocorrência de AVC. Identificando e quantificando tais fatores é possível traçar um perfil de doente em risco, atuando sobre ele através de medidas preventivas de forma a minimizar o impacto deste problema em termos pessoais, sociais e financeiros. Para atingir este objetivo foi analisada uma amostra de indivíduos internados em 2012 na Unidade de AVC do Centro Hospitalar do Tâmega e Sousa. Dos casos analisados 87,8% são causados por AVCI (isquémicos) e 12,2% por casos de AVCH (hemorrágicos). Do total dos casos, 58,9% apresentam sequelas. A hipertensão, a diabetes de Mellitus e o Colesterol apresentam-se como antecedentes clínicos com elevado fator de risco. O tabagismo regista grande importância na propulsão dos anteriores fatores analisados assim como o alcoolismo. Conclui-se que a prevenção do AVC e outras doenças cardiovasculares é importante desde a idade escolar, dando-se especial importância ao período que antecede os 36 anos de idade, altura em que se começa a verificar uma subida agravada de ocorrências. O investimento na prevenção e vigilância médica do cidadão é um fator crucial neste período podendo reduzir em grande escala os custos associados a médio-longo prazo para todas as partes intervenientes.

Prevalência de obstrução numa população exposta ao fumo do tabaco – Projecto PNEUMOBIL

A espirometria não atingiu ainda a divulgação que se justificaria em patologia respiratória, ou indivíduos que se encontram em risco relativamente a esta patologia, cujo diagnóstico é insuficiente, havendo um escasso conhecimento, e consequente controlo, dos custos atribuíveis a estas doenças, com destaque para a doença pulmonar obstrutiva crónica (DPOC). O PNEUMOBIL, iniciativa que visa esta divulgação entre fumadores e ex-fumadores, foi reactivado, após 10 anos de aplicação em Portugal, revelando agora, numa amostra de 5324 indivíduos, em que cerca de 50% ainda mantêm os hábitos tabágicos, sejam do sexo masculino ou feminino, que houve uma elevada prevalência de obstrução detectada por espirometria (30% e 25%, respectivamente) nas pessoas rastreadas perto de centros de saúde (grupo público) e em empresas (grupo privado). Este risco não se explica em regra por exposição ocupacional, nem se relaciona com a maioria dos sintomas respiratórios, muito frequentes nos rastreados. Apenas a dispneia (OR = 1,28; p = 0,02) e os episódios frequentes de expectoração (OR = 1,21; p = 0,008) ou de bronquite aguda (OR = 1,31; p = 0,05) revelam alguma relação com a obstrução. O reconhecimento prévio da DPOC é muito reduzi-do e a presença de obstrução não se correlaciona (p = 0,204) com o assumir da condição de portador.

Impact of excipients in the chronic toxicity of fluoxetine on the alga Chlorella vulgaris

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) widely used in the treatment of major depression. It has been detected in surface and wastewaters, being able to negatively affect aquatic organisms. Most of the ecotoxicity studies focused only in pharmaceuticals, though excipients can also pose a risk to non-target organisms. In this work the ecotoxicity of five medicines (three generic formulations and two brand labels) containing the same active substance (fluoxetine hydrochloride) was tested on the alga Chlorella vulgaris, in order to evaluate if excipients can influence their ecotoxicity. Effective concentrations that cause 50% of inhibition (EC50) ranging from 0.25 to 15 mg L−1 were obtained in the growth inhibition test performed for the different medicines. The corresponding values for fluoxetine concentration are 10 times lower. Higher EC50 values had been published for the same alga considering only the toxicity of fluoxetine. Therefore, this increase in toxicity may be attributed to the presence of excipients. Thus more studies on ecotoxicological effects of excipients are required in order to assess the environmental risk they may pose to aquatic organisms.

Dot-enzyme-linked immunosorbent assay (Dot-ELISA) for detection of pneumococcal polysaccharide antigens in pleural fluid effusion samples.: Comparison with bacterial culture, counterimmunoelectrophoresis and latex agglutination

A dot-enzyme-linked immunosorbent assay (Dot-ELISA) for pneumococcal antigen detection was standardized in view of the need for a rapid and accurate immunodiagnosis of acute pneumococcal pneumonia. A total of 442 pleural fluid effusion samples (PFES) from children with clinical and laboratory diagnoses of acute bacterial pneumonia, plus 38 control PFES from tuberculosis patients and 20 negative control serum samples from healthy children were evaluated by Dot-ELISA. The samples were previously treated with 0.1 M EDTA pH 7.5 at 90°C for 10 min and dotted on nitrocellulose membrane. Pneumococcal omniserum diluted at 1:200 was employed in this assay for antigen detection. When compared with standard bacterial culture, counterimmunoelectrophoresis and latex agglutination techniques, the Dot-ELISA results showed relative indices of 0.940 to sensitivity, 0.830 to specificity and 0.760 to agreement. Pneumococcal omniserum proved to be an optimal polyvalent antiserum for the detection of pneumococcal antigen by Dot-ELISA. Dot-ELISA proved to be a practical alternative technique for the diagnosis of pneumococcal pneumonia.

Co-Authorship of scientists in the energy field: an exploratory study of the ETDE World Energy Database (ETDEWEB) using Social Network Analysis

Paper presented at the 5th European Conference Economics and Management of Energy in Industry, Vilamoura, Algarve. Apr. 14-17, 2009, 11p. URL: http:// www.cenertec.pt/ecemei/

O motivo musical na azulejaria portuguesa da primeira metade do século XVIII

Tese de Doutoramento em Ciências Musicais Históricas

Calcium signaling and the novel anti-proliferative effect of the UTP-sensitive P2Y11 receptor in rat cardiac myofibroblasts

During myocardial ischemia and reperfusion both purines and pyrimidines are released into the extracellular milieu, thus creating a signaling wave that propagates to neighboring cells via membrane-bound P2 purinoceptors activation. Cardiac fibroblasts (CF) are important players in heart remodeling, electrophysiological changes and hemodynamic alterations following myocardial infarction. Here, we investigated the role UTP on calcium signaling and proliferation of CF cultured from ventricles of adult rats. Co-expression of discoidin domain receptor 2 and -smooth muscle actin indicate that cultured CF are activated myofibroblasts. Intracellular calcium ([Ca2+]i) signals were monitored in cells loaded with Fluo-4 NW. CF proliferation was evaluated by the MTT assay. UTP and the selective P2Y4 agonist, MRS4062, caused a fast desensitizing [Ca2+]i rise originated from thapsigargin-sensitive internal stores, which partially declined to a plateau providing the existence of Ca2+ in the extracellular fluid. The biphasic [Ca2+]i response to UTP was attenuated respectively by P2Y4 blockers, like reactive blue-2 and suramin, and by the P2Y11 antagonist, NF340. UTP and the P2Y2 receptor agonist MRS2768 increased, whereas the selective P2Y11 agonist NF546 decreased, CF growth; MRS4062 was ineffective. Blockage of the P2Y11receptor or its coupling to adenylate cyclase boosted UTP-induced CF proliferation. Confocal microscopy and Western blot analysis confirmed the presence of P2Y2, P2Y4 and P2Y11 receptors. Data indicate that besides P2Y4 and P2Y2 receptors which are responsible for UTP-induced [Ca2+]i transients and growth of CF, respectively, synchronous activation of the previously unrecognized P2Y11 receptor may represent an important target for anti-fibrotic intervention in cardiac remodeling.

Influenza em animais heterotérmicos

O objetivo foi pesquisar Ortomyxovirus em animais heterotérmicos. Coletou-se sangue de serpentes dos gêneros Bothrops e Crotalus e de sapo e rãs dos gêneros Bufo e Rana, para a detecção dos receptores de hemácias e anticorpos específicos, ao vírus influenza, pelos testes de hemaglutinação e inibição da hemaglutinação, respectivamente. Pelo teste de hemaglutinação, verificou-se que serpentes e sapos em cativeiro apresentaram receptores em suas hemácias para o vírus influenza, humano e eqüino do tipo A e tipo B. O mesmo ocorreu com serpentes recém chegadas. Quanto ao teste de inibição da hemaglutinação dos soros dos répteis observou-se títulos protetores de anticorpos aos vírus influenza tipo A (origens humana e eqüina) e tipo B. Com soro de sapo não se observou reação de inibição da hemaglutinação porém, 83,3% das rãs obtiveram médias de 40UIH para algumas cepas. Conclui-se que animais heterotérmicos podem oferecer condições de hospedeiros aos vírus influenza, assim como susceptibilidade à infecção.

A Organização das Nações Unidas e a Questão Colonial Portuguesa: 1961-1970

Tese apresentada para cumprimento dos requisitos necessários à obtenção do grau de Doutor em História Contemporânea

Modalidades de avaliação de Serviços de Bibliotecas Universitárias: estudo exploratório

A avaliação de desempenho dos serviços fornecidos à comunidade académica pelo sistema biblioteca universitária do ensino público, em Portugal, é o objecto desta investigação. Trata-se de um estudo exploratório das práticas e ferramentas de avaliação utilizadas e das concepções dos Profissionais de Informação, responsáveis ou coresponsáveis pela gestão das bibliotecas universitárias, no que respeita ao auto diagnóstico do desempenho organizacional como forma de melhorar a decisão, a eficácia, os resultados e os impactos dos serviços fornecidos às respectivas comunidades. A observação – estruturada e controlada para responder à pergunta de partida – pressupôs a elaboração de uma ferramenta híbrida, simultaneamente quantitativa e qualitativa que nos pareceu a forma mais adequada de responder aos objectivos da investigação. O ratio de resposta corresponde a 19,04% do universo de bibliotecas universitárias do ensino público. O diagnóstico de avaliação organizacional das bibliotecas universitárias do ensino público consubstanciou-se nos indicadores previstos na NP ISO 11620, standard que normaliza a metodologia para aferir a utilidade e relevância dos serviços fornecidos. Os resultados demonstram que apenas 25% das bibliotecas entendeu a necessidade de definir documentos estratégicos e de alinhamento da organização como a visão e, apesar de 70% afirmar que avalia os serviços, só 10% o faz utilizando a ISO 11620. A mesma dificuldade se sente na aplicação do standard relativo à recolha de dados estatísticos (ISO 2789): apenas 5% afirma utilizar a norma. A reduzida utilização destes dois standards dificulta a inevitável comparação do desempenho entre bibliotecas universitárias, num futuro próximo. Nenhuma biblioteca universitária participante faz avaliações custo/eficácia, custo/benefício ou qualidade/custo e nenhuma compara os resultados com as suas congéneres. O plano estratégico é maioritariamente (75% das bibliotecas) preparado em função de percepções que se pretendem alterar e só 8,3% o faz de acordo com a missão e objectivos estratégicos da Universidade. Constata-se a falta de instrumentos de alinhamento organizacional, o que compromete essencialmente a gestão de topo ou estratégica. Em nenhum caso o orçamento depende dos resultados do desempenho.