Sara Emanuela Pagnotta

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The motor output of hypoglossal motoneurons to tongue muscles takes place in concert with the respiratory rhythm and is determined by the balance between excitatory glutamatergic transmission and inhibitory transmission mediated by glycine or GABA. The relative contribution by these transmitters is a phasic phenomenon modulated by other transmitters. We(More)
The results of a neutron diffraction experiment performed on aqueous solutions of KSCN are analyzed and discussed in comparison with similar data for KCl and KOH solutions. The effect of the different ions on the structure of water and the differences and similarities among the ion solvation shells are discussed in detail. In particular it is shown that the(More)
The observation made by early naturalists that some organisms could tolerate extreme environmental condisions and "enjoy the advantage of real resurrection after death" [ Spallanzani , M. Opuscules de Physique Animale et Vegetale 1776 (translated from Italian by Senebier , J. Opuscules de Physique Animale et Vegetale 1787 , 2 , 203 - 285 )] stimulated(More)
Quantum effects on the water proton dynamics over the surface of a hydrated protein are measured by means of broadband dielectric spectroscopy and deep inelastic neutron scattering. Dielectric spectroscopy indicates a reduced energy barrier for a hydrogenated protein sample compared to a deuterated one, along with a large and temperature-dependent isotopic(More)
Trehalose solutions were investigated by means of broadband dielectric spectroscopy at different water contents, ranging from an anhydrous sample to w(C) = 40%. While the structural α-relaxation was detectable only in the low hydration and dry samples, and in a quite limited range of temperatures, two secondary processes were presented and characterized in(More)
The reliability of tripeptide glutathione as an excellent model for protein-water interactions is tested by means of broadband dielectric spectroscopy. Measurements performed on aqueous solutions with different water contents show a surprisingly rich relaxation map that strongly resembles those observed for more complex protein macromolecules. At variance(More)
Conventional ion-sensitive microelectrodes cannot be used in small cells, since they create too large an electrical leak at the site of penetration. Membrane potentials can be measured in such cells with the whole-cell configuration of the patch-clamp technique, after obtaining a high-resistance seal (giga-seal) to the cell membrane. Achieving such seals(More)
We show that is possible to look at the glass transition as a percolation transition in phase space. This study has been carried out on a hydrated globular enzyme for which the thermodynamic transition and the percolative transition could have a functional significance. The approach adopted is based on the identity of roles played respectively by the glass(More)
The relaxation dynamic of ribose and deoxyribose water solutions at different concentrations has been studied by broadband dielectric spectroscopy and differential scanning calorimetry in the temperature range of 150-250 K. Two relaxation processes are observed for all the hydration levels; the slower (process I) is related to the relaxation of the whole(More)
The momentum distribution of protons in the hydration shell of a globular protein has been measured through deep inelastic neutron scattering at 180 and 290 K, below and above the crossover temperature Tc=1.23Tg, where Tg=219 K is the glass transition temperature. It is found that the mean kinetic energy of the water hydrogens shows no temperature(More)