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Sucção digital

Projeto de Pós Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária. ; Durante os últimos dez anos, o número de estudos científicos em torno do tema sucção digital aumentou bastante. De facto, o interesse em ver esclarecidas questões pertinentes tem-se revelado um bom incentivo, apesar de ainda hoje existirem muitas cont...

Jogar com conteúdos matemáticos

Os níveis de literacia matemática, nos estudantes portugueses, têm vindo a ser uma preocupação para aqueles que observam os resultados insatisfatórios nas provas nacionais. O crescente menosprezo dos alunos face à matemática conduz a que os profissionais de educação repensem nas suas práticas. A presente investigação surge pelas inquietações de uma das investigadoras ao constatar no terreno a desmotivação dos s...

Production of glycerol and 1,3-propanediol from renewable ressources : study of...

1,3-Propanediol can be biologically produced from glycerol by several microorganisms, namely clostridia. However, no natural microorganism is able to synthesize 1,3-propanediol from glucose. Different strategies have been tried to accomplish this conversion and set up a flexible process operating either on glycerol or glucose. In this work the production of 1,3 - propanediol from glucose and sugar cane molasses...

1,3-Propanediol production in a two-step process fermentation from renewable fe...

In this work, the production of 1,3-propanediol from glucose and molasses was studied in a two-step process using two recombinant microorganisms. The first step of the process is the conversion of glucose or other sugar into glycerol by the metabolic engineered Saccharomyces cerevisiae strain HC42 adapted to high (>200 g l−1) glucose concentrations. The second step, carried out in the same bioreactor, was perfo...

Tricarbonyl M(I) (M = Re, 99mTc) complexes bearing acridine fluorophores : synt...

© The Royal Society of Chemistry 2010 ; New pyrazolyl-diamine ligands with acridine derivatives at the 4-position of the pyrazolyl ring were synthesized and characterized (L1 and L2). Coordination towards the fac-[M(CO)3]+ (M = Re, 99mTc) led to complexes fac-[M(CO)3(κ3-L)] (L = L1: M = Re1, Tc1; L = L2: M = Re2, Tc2). The interaction of the novel pyrazolyl-diamine ligands (L1 and L2) and rhenium(I) complexes ...

Sequential injection kinetic flow assay for monitoring glycerol in a sugar ferm...

A sequential injection system to monitor glycerol in a Saccharomyces cerevisiae fermentation process was developed. The method relies on the rate of formation of nicotinamide adenine dinucleotide in its reduced form (NADH, measured spectrophotometrically at 340 nm) from the reaction of glycerol with NAD+ cofactor, catalysed by the enzyme glycerol dehydrogenase present in solution. This procedure enables the de...

Microbial conversion of glycerol to 1,3-propanediol$ephysiological comparison o...

Clostridium acetobutylicum is not able to grow on glycerol as the sole carbon source since it cannot reoxidize the excess of NADH generated by glycerol catabolism. Nevertheless, when the pSPD5 plasmid, carrying the NADH-consuming 1,3-propanediol pathway from C. butyricum VPI 3266, was introduced into C. acetobutylicum DG1, growth on glycerol was achieved, and 1,3-propanediol was produced. In order to compare th...

Metabolic engineering of clostridium acetobutylicum for the industrial producti...

Clostridium butyricum is to our knowledge the best natural 1,3-propanediol producer from glycerol and the only microorganism identified so far to use a coenzyme B12-independent glycerol dehydratase. However, to develop an economical process of 1,3-propanediol production, it would be necessary to improve the strain by a metabolic engineering approach. Unfortunately, no genetic tools are currently available for C...

Alcohols, esters and heavy sulphur compounds production by pure and mixed cultu...

Strains of Hanseniaspora uvarum, Hanseniaspora guilliermondii and Saccharomyces cerevisiae were used as pure or mixed starter cultures in commercial medium, in order to compare their kinetic parameters and fermentation patterns. In pure and mixed cultures, yeasts presented similar ethanol yield and productivity. Pure cultures of H. uvarum and S. cerevisiae showed a specific growth rate of 0.38 h⁻¹; however, thi...

Utilização de compostos azotados por estirpes de Saccharomyces cerevisiae duran...