Tocqueville : democracia e guerra

Alexis de Tocqueville publicou o «De la Démocratie en Amérique» em 1835 e 1840 e nele dedica alguns capítulos à guerra e aos exércitos dos «tempos democráticos». Recordar, reflectir e comentar essas poucas páginas é um acto de justiça e uma necessidade. Acto de justiça, porque a obsolência de alguns conceitos, função da modernidade da democracia e da (circunstância) de Tocqueville, não perturba a intemporalidade de outras ideias da sua magnífica construção filosófica e social. Uma necessidade, porque a democracia e a guerra evoluíram nestes últimos 160 anos, porque a democracia não atingiu a universalidade, porque a guerra continua a perturbar o nosso quotidiano. Reler Tocqueville não é, apenas, conhecer o seu pensamento: é, principalmente, meditar sobre o destino da Humanidade

Smoothing membrane protein structure determination by initial upstream stage improvements

Membrane proteins (MP) constitute 20-30% of all proteins encoded by the genome of various organisms and perform a wide range of essential biological functions. However, despite they represent the largest class of protein drug targets, a relatively small number high-resolution 3D structures have been obtained yet. Membrane protein biogenesis is more complex than that of the soluble proteins and its recombinant biosynthesis has been a major drawback, thus delaying their further structural characterization. Indeed, the major limitation in structure determination of MP is the low yield achieved in recombinant expression, usually coupled to low functionality, pinpointing the optimization target in recombinant MP research. Recently, the growing attention that have been dedicated to the upstream stage of MP bioprocesses allowed great advances, permitting the evolution of the number of MP solved structures. In this review, we analyse and discuss effective solutions and technical advances at the level of the upstream stage using prokaryotic and eukaryotic organisms foreseeing an increase in expression yields of correctly folded MP and that may facilitate the determination of their three-dimensional structure. A section on techniques used to protein quality control and further structure determination of MP is also included. Lastly, a critical assessment of major factors contributing for a good decision-making process related to the upstream stage of MP is presented.publishe

English loan words and phrases in Portuguese

Resumo: A intenção deste artigo é promover o trabalho realizado por dois alunos da Escola Superior de Educação de Viseu, orientados pelo seu professor de Inglês, John McKenny. O projecto/dicionário de expressões inglesas que entraram no português por empréstimo ou 'calque' estará em permanente actualização, graças à colaboração dos leitores. Abstract: This brief article was written to draw readers attention to an ongoing piece of work carried out by two students of the Viseu School of Education (ESEV) in collaboration with their English teacher, John McKenny. An online Internet dictionary of English loan words in Portuguese has been created and it is to be hoped that with readers' co-operation it can be continually enriched and updated

Pharmaceutical drugs as emerging pollutants in aqueous media of Northeast Portugal

Emerging pollutants are potentially toxic substances that although found in very small concentrations can produce hazard effects to the environment. Due to their very small concentrations they are not yet included in the water quality monitoring programs neither in national or international environmental control regulations. Pharmaceutical and Personal Care Products (PPCPs) represent an important group of emerging pollutants owing to increased worldwide consumption and to their inherent capacity to induce physiological harmful effects in very low doses, which raises several concerns related with the potential adverse effects on humans, animals and environmental systems. In this work, it will be presented the development and validation of a complete experimental methodology proposed for the monitoring of pharmaceutical drugs. The method is based on solid phase extraction (SPE) followed by analysis with high performance liquid chromatography with a diode array detector (HPLC-DAD). Experimental results obtained with two different columns will be presented. An analytical Nucleosil 100-5 C18 column, 150 mm x 4.6 mm, obtained from Macherey-Nagel for compounds with lower pKa values and a SiliaChrom XT C18 column, 4.6 mm x 250 mm, obtained from SiliCycle for compounds with higher pKa values. The method is validated by the analysis of real aqueous matrices samples obtained from different water media sources, such as, swimming pools, rivers and wastewater treatment plants. To extend the scope of the analytical method and thus obtain a broader study, several drugs were selected, belonging to five different pharmacological classes: non-steroidal anti-inflammatory (ibuprofen, acetylsalicylic acid, ketoprofen, naproxen and diclofenac), analgesic (paracetamol), antibiotic (sulfamethoxazole), an anticonvulsant (carbamazepine) and a central nervous system stimulator (caffeine). These compounds were selected due to their high level of use and medical prescription and, consequently, leading to a high probability of environmental contamination.info:eu-repo/semantics/publishedVersio

Valorization of used cooking oils through ionic liquid catalyzed biodiesel conversion processes

Biodiesel is defined as a natural and renewable substitute for fossil fuels and can be produced through the transesterification or by esterification reaction of free farry acids of a vegetable oil, animal fat or waste cooking ois, with an alcohol, usuallt methanol or ethanol in the presence of homogeneous, heterogeneous or enzymatics catalystsinfo:eu-repo/semantics/publishedVersio

Optimization and kinetic study of esterification reaction of oleic acid using [HMIM]HSO4 as catalyst

Biodiesel Biodiesel is an alternative fuel to petrodiesel. It can be produced from a wide range of raw materials such as vegetable oils and animal fats. Yet, the use of sources that do not compete with the food market, such as waste cooking oils - which usually feature high levels of free fatty acids (FFA’s), can lead to problems in the process of biodiesel production through alkaline transesterification. Therefore, new methodologies to successfully apply acidic oils need to be developed.info:eu-repo/semantics/publishedVersio

Study of Biodiesel Production through Esterification Catalysed by Imidazolium-based Ionic Liquids

Biodiesel is an alternative diesel fuel which is industrially produced from vegetable oils and animal fats, by transesterification reactions. Thus, currently most commercial biodiesel is produced from oils, using alkaline catalysts. On the other hand, conventional mineral acid catalysts like sulfuric acid, are commonly used for catalyzing esterification reactions of fatty acids which also produce biodiesel. However, Ionic Liquids (ILs) offer an alternative solution to classical homogeneous catalysts, because it can be recycled and reused in subsequent runs after recovery steps. An IL is a molten salt consisting of a cation and an anion, with low melting temperature. In this study, a Brønsted acidic IL, 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM][HSO4]) was used as a catalyst in the esterification of oleic acid with methanol into biodiesel. The effect of different operation parameters such as oleic acid to methanol molar ratio, amount of catalyst, reaction temperature, and reaction time were tested. The optimal conditions for esterification of oleic acid were experimentally determined at 1/10 for oleic acid/methanol molar ratio, 2.5 %wt for the amount of catalyst, a reaction time of 4 h and reaction temperature of 90oC. The Fatty Acid Methyl Esters (FAMEs) content was analyzed using Gas Chromatography.info:eu-repo/semantics/publishedVersio