Determinação direta de molibdênio em comprimidos polivitamínicos por voltametria em meio não aquoso

Adsorptive stripping voltammetry carried out in a homogeneous ternary solvent composed of N,N-dimethylformamide, water and ethanol, with alpha-benzoinoxime (alphaBO) as the complexing agent for Mo(VI) and a 0.5 mol L-1 acetic acid - sodium acetate buffer as supporting electrolyte was successfully used for the determination of molybdenum in polyvitamin-polymineral tablets. Tablet samples were analyzed and the results were compared with those obtained both by graphite furnace atomic absorption and by recovery tests, with good correlations, indicating that this may be considered as an alternative procedure for routine determination of Mo(VI) in pharmaceutical samples.

Classificação de água de coco processada e natural por meio de HCA, PCA e teores de íons metálicos determinados por ICP OES

Inductively Coupled Plasma Optical Emission Spectrometry was used to determine Ca, Mg, Mn, Fe, Zn and Cu in samples of processed and natural coconut water. The sample preparation consisted in a filtration step followed by a dilution. The analysis was made employing optimized instrumental parameters and the results were evaluated using methods of Pattern Recognition. The data showed common concentration values for the analytes present in processed and natural samples. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) indicated that the samples of different kinds were statistically different when the concentrations of all the analytes were considered simultaneously.

Estudo espectroscópico do equilíbrio entre espécies hexacoordenada e pentacoordenada dos monômero d nativo e reconstituído da hemoglobina extracelular gigante de Glossoscolex paulistus em meio alcalino

UV-Vis and fluorescence spectroscopic studies of native and reconstituted d monomers from Glossoscolex paulistus were performed in alkaline pH. In addition to the presence of aquomet and hemichrome hexacoordinated species, a pentacoordinated species occurs. This latter species, which presents an imidazolate group of axial histidine as fifth ligand, is identified by the blue-shifted low-intensity Soret band and LMCT band. The pentacoordinated species must occur due to partial polypeptide unfolding.

Determinação das propriedades catalíticas em meio aquoso e orgânico da lipase de Candida rugosa imobilizada em celulignina quimicamente modificada por carbonildiimidazol

Microbial lipase from Candida rugosa was immobilized by covalent binding on wood cellulignin (Eucaliptus grandis) chemically modified with carbonyldiimidazole. The immobilized system was fully evaluated in aqueous (olive oil hydrolysis) and organic (ester synthesis) media. A comparative study between free and immobilized lipase was carried out in terms of pH, temperature and thermal stability. A higher pH value (8.0) was found optimal for the immobilized lipase. The optimal reaction temperature shifted from 37 °C for the free lipase to 45 °C for the immobilized lipase. The pattern of heat stability indicated that the immobilization process tends to stabilize the enzyme. Kinetics tests at 37 °C following the hydrolysis of olive oil obeyed the Michaelis-Menten rate equation. Values for Km = 924.9 mM and Vmax = 198.3 U/mg were lower than for free lipase, suggesting that the affinity towards the substrate changed and the activity of the immobilized lipase decreased during the course of immobilization. The immobilized derivative was also tested in the ester synthesis from several alcohols and carboxylic acids.

Adsorção de fenol sobre carvão ativado em meio alcalino

The present study describes phenol adsorption on commercial active carbon (CAF) under alkaline conditions in the concentration range of 0.01 to 2.08 mmol L-1. Surface characterization has been performed by means of surface area measurements, IR spectroscopy and Boehm titration. The effect of temperature on the adsorption equilibrium isotherm was investigated at 23, 30, 40, 50 and 60 °C. The results showed that adsorption capacity decreased with increasing temperature. The adsorption kinetics and the role of surface characteristics on the adsorption of phenol also discussed.

Desreguladores endócrinos no meio ambiente: efeitos e conseqüências

There is an increasing interest in micropollutants in the environment that can interfere with the endocrine system, affecting health, growth and reproduction of animals and humans. These substances are known as Endocrine Disrupting Chemicals (EDCs) and can be found in domestic sewage, domestic wastewater treatment plant effluents, and in natural and potable waters. There are numerous chemicals classified as EDCs, such as pesticides, chemicals used and produced by chemical industries and natural and synthetic estrogens. EDCs can be related to the increase of the incidence of anomalies in the reproductive system of animals, cancer in humans and reduction of the masculine fertility.

Visões de meio ambiente e suas implicações pedagógicas no ensino de química na escola média

This study was realized with high school Chemistry teachers from the region of and around Florianópolis (SC). It examines the pedagogical implications of these teachers' views on environmental issues, and discusses the possibilities and difficulties of bringing these issues into the Chemistry classroom. The semi-structured interviews were analyzed using Textual Discourse Analysis principles. The dominance of content-based teaching and traditional pedagogical approaches appears to hinder curricular changes. Most subjects pay little heed to environmental issues and their relation to Chemistry, and endorse a view of science as neutral, and the environment as anthropocentric - views far from Green Chemistry principles.

Experiència dels cuidadors i les cuidadores principals informals que tenen cura d'un familiar vell amb demència des de fa més de quatre anys

El treball que es presenta vol respondre la pregunta de quina és l’experiència dels cuidadors i les cuidadores principals informals que tenen cura d’un familiar vell amb demència des de fa més de 4 anys. Després de plantejar les hipòtesis de partida, es defineixen els objectius generals i específics i s’expliquen l’interès, la justificació, la rellevància i l’aportació d’aquest estudi. En l’apartat corresponent a l’estat de la qüestió i la fonamentació conceptual, després de fer una revisió bibliogràfica, es descriuen els elements que formen part d’aquesta temàtica: perfils dels receptors de cures i de les cuidadores, significat de tenir cura, vida quotidiana i qualitat de vida i descripció del model conceptual de Virginia Henderson. En el capítol següent s’exposen la metodologia, el paradigma i el mètode d’investigació utilitzats en aquest treball, així com les matrius d’anàlisi del contingut i del discurs. A partir d’aquí s’exposen els resultats en funció dels objectius plantejats. En la discussió, s’analitzen i s’interpreten les dades obtingudes i es contraposen amb altres estudis, a més de fer-se una reflexió personal sobre els aprenentatges adquirits i una proposta de línies de treball futures. A continuació s’exposen unes conclusions per resumir la informació obtinguda. En la secció de referències bibliogràfiques es detallen les fonts consultades, i en els annexos hi consten els models d’entrevista i de matriu per a l’anàlisi de dades, el full de consentiment informat, així com el buidatge i l’anàlisi de les entrevistes.

Experiència dels excuidadors i excuidadores principals informals que han tingut cura d'un familiar vell amb demència després de la seva mort

El treball aquí exposat té com a objectiu conèixer i comprendre l’experiència dels excuidadors i excuidadores principals informals que han tingut cura d’un familiar vell amb demència després de la seva mort. Es plantegen les hipòtesis i els objectius generals i específics. S’hi exposa també, la justificació del tema, l’interès, la rellevància a nivell social i professional, i la seva aportació en el món de la salut. En l’apartat de l’estat de la qüestió i la fonamentació conceptual, després d’una revisió bibliogràfica sobre el tema, es descriuen els diferents apartats que formen part del marc teòric: perfil de la persona gran dement que rep cures informals , el perfil dels cuidadors/es, les conseqüències de tenir cura d’una persona dement, l’estat dels excuidadors/es després de la mort del familiar vell amb demència i el procés de dol. El segon apartat inclou la metodologia, i el mètode d’investigació. A més, inclou les matrius d’anàlisi del contingut i del discurs, i es plantegen els resultats en funció dels objectius marcats. En la discussió, a partir de les dades obtingudes, es realitza la seva anàlisi, s’interpreta el resultat i es contraposa amb altres estudis consultats. Finalment s’exposen les conclusions per resumir la informació obtinguda i la metodologia utilitzada. Es realitza una reflexió sobre els aprenentatges adquirits i les aportacions del treball i s’apunten noves vies de recerca. En les referències bibliogràfiques s’especifiquen les fonts consultades i en els annexos hi consten els models d’entrevista i de matriu per a l’anàlisi de dades, el full de consentiment informat i també el buidatge i l’anàlisi de les entrevistes.

La desigualdad en el consumo familiar. Diferencias de género en la España contemporánea (1850-1930)

In the last few years, Economic Theory has revised two basic ideas around the economics of the household: that family income is the result of the individual income of each of its members (income pooling), and that all family members living in the household have equal access to its resources. Unequal access to family resources (among women and men, on the one hand, and among the elderly, adults and children, on the other), is now understood as an input (for instance, that women eat less food and of worst quality than men), and as an output (for instance that women have poorer health, higher epidemic mortality, or are less tall than men as a result, among other things, of having received less food and poorer medical care, and/or of a heavier workload). Despite the fact that inequality in intra‐family consumption has become the center of attention in academic and international agencies, it can still not be found in the agenda of Economic History. In this paper we look at some of the resources consumed by Spanish families in the 19th century: food, alcoholic beverages, clothes and shoes. Medical topographies, our main source, suggest that unequal access to family resources among household members had a strong impact on their health and wellbeing.