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Variability during Marine Isotope Stages 11, 13 and 15 as revealed at IODP Site...

Estudo dos foraminíferos bentónicos aplicados à caracterização dos períodos gla...

Tese de mestrado em Geologia do Ambiente (Riscos Geológicos e Ordenamento do Território), apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011 ; Os foraminíferos bentónicos são frequentemente utilizados como proxies de vários parâmetros ambientais, fornecendo indicações sobre as condições ecológicas e oceanográficas do passado. A sua relação com os parâmetros ambientais tanto varia de r...

Synthesis and kinetic investigation of the selective acydolysis of para-substit...

Several derivatives of N-phenylacetyl-N-benzyl-alpha,alpha-dimethylglycine cyclohexylamide and their alpha,alpha-dibenzylglycine analogues were synthesised by a Ugi-Passerini reaction. In addition, a few analogues of the former but having an N-phenyl instead of a benzyl group at the nitrogen atom were synthesised. The compounds in each of these three sets differed from each other at the position 4 of the N-benz...

Kinetic investigation of the effect of the amino acid side chains in the select...

Accurate kinetic measurements of the rate constants for the acidolysis of five N-acetyl-N-(4-methoxybenzyl)-alfa,alfa-trialkyl glycine cyclohexyl amides in TFA were performed at 25.00 ºC and the reactions monitored by HPLC. The results were in all cases consistent with a first order behaviour with respect to the substrate. No direct correlation was obtained with this data between rate constant values and struct...

Supravalvular Congenital Mitral Stenosis

Congenital supravalvular mitral stenosis is a rare malformation characterized by the presence of a shelf-like fibrous membrane, with 1 or 2 small orifices, covering and obstructing the mitral valve. The membrane is positioned closely to the mitral valve (and sometimes it is attached to it); therefore, a preoperative diagnosis is inevitably difficult, even with the use of biplane echocardiography. Two patients w...