Publications by authors named "Popa-Nita S"

In the treatment of oropharyngeal dysphagia, the link between diagnosis and prescription of thickened liquids that are safe to swallow is not always straightforward. Frequently, the capacity to objectively assess and quantify the rheological properties of diagnostic test fluids and to select "rheologically equivalent" dietary products is missing. Perhaps sometimes the importance of an objective comparison is not fully appreciated because two liquids seem reasonably similar in a subjective comparison (e.

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The structural organization of chitosan, a cationic polyelectrolyte, in aqueous solutions of high ionic strength, is investigated by quasi-elastic light scattering and wet scanning transmission electron microscopy. The formation of submicrometric chain aggregates driven by hydrophobic interactions is evidenced. These heterogeneities are at the core of the multiscale morphology of physical hydrogels processed from this polysaccharide.

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A method allowing the evaluation of the solvophilic/solvophobic character of polyelectrolytes from their conformation in solution is discussed. Analyzed systems are salt-free aqueous solutions of natural copolysaccharides with controlled chemical structures. Small-angle X-ray scattering diagrams revealed their conformation by the "polyelectrolyte peak".

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The existence of two mechanisms involved in the ultrasonically induced depolymerization of chitosan is evidenced. The first leads to a rapid scission of polymer chains and a lowering of the polydispersity, and the second is responsible for obtaining short polymer chains and oligomers with a polydispersity increase. A systematic experimental study allowed us to identify and quantify the main parameters influencing the chain scission kinetics.

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Microtubule-associated protein 1B is an essential protein during brain development and neurite outgrowth and was studied by several assays to further characterize actin as a major interacting partner. Tubulin and actin co-immunoprecipitated with MAP1B at similar ratios throughout development. Their identity was identified by mass spectrometry and was confirmed by Western blots.

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Shapes of the interface between the L1 and cubic Pn3 m phases in the mixture C(12)EO(2)/water are studied. The concave and convex variants of the interface are realised using Pn3 m crystals surrounded by the L1 phase and L1 inclusions on surfaces and in the bulk of the Pn3 m phase. It is shown that both variants of the Pn3 m/L1 interface contain the (111)-type facets in coexistence with everywhere else rough surfaces.

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