Search results for " ambientali"
showing 10 items of 774 documents
Ground motion phenomena in Caltanissetta (Italy) investigated by InSAR and geological data integration
2008
Urban areas are frequently affected by ground instabilities of various origins. The location of urban zones affected by ground instability phenomena is crucially important for hazard mitigation policies. Satellite-based Interferometric Synthetic Aperture Radar (InSAR) has demonstrated its remarkable capability to detect and quantify ground and building motion in urban areas, especially since the development of Advanced Differential Interferometric SAR techniques (A-DInSAR). In fact, the high density of re.ectors like buildings and infrastructures in urban areas improves the quality of the InSAR signal, allowing sub-centimetric displacements to be reliably detected. The A-DInSAR techniques a…
Electron Spin Resonance and Thermoluminescence dating of shells and sediments from Sambaqui (shell mound) Santa Marta II, Brazil
2020
In Tupi, the word Sambaqui means “mound of shells”. These archaeological sites are cultural vestiges left by the prehistoric occupation of the Brazilian coast from five to six thousand years ago. Mollusks, fishes, and other marine edible foods were important for the survival of this population. The remains of foods, mainly shells, were heaped up, giving a mound of different proportions, which became part of the landscape of the Brazilian coastal plain. Due to the large number of Sambaquis in Brazil and considering that Sambaqui Santa Marta II, Laguna, SC, has not yet been dated, Electron Spin Resonance (ESR) measurements were performed in aragonite shells collected from different layers of …
EPR dating of shells from Malhada Marsh, Rio de Janeiro, Brazil
2020
The formation of the coastal plain of the Brazilian sea is mainly due to the fluctuation of relative sea level in the past. Armacao dos Buzios or simply Buzios is a municipality in the microregion of lakes, in the state of Rio de Janeiro. In this region there is a lowland area about two meters above current sea level. This lowland area is also known as coastal plain of Una River. It is expected that during the Holocene period the sea level reached a maximum about 2.5 meters above the current level. During that time billions of mollusks lived and proliferated in the shallow waters around the coastal plain of the Una River. As they died their shells formed a layer in the soil including Malhad…
Stability and disassembly properties of human naïve Hsp60 and bacterial GroEL chaperonins.
2015
Human Hsp60 chaperonin and its bacterial homolog GroEL, in association with the corresponding co-chaperonins Hsp10 and GroES, constitute important chaperone systems promoting the proper folding of several mitochondrial proteins. Hsp60 is also currently described as a ubiquitous molecule with multiple roles both in health conditions and in several diseases. Naïve Hsp60 bearing the mitochondrial import signal has been recently demonstrated to present different oligomeric organizations with respect to GroEL, suggesting new possible physiological functions. Here we present a combined investigation with circular dichroism and small-angle X-ray scattering of structure, self-organization, and sta…
Aggregation properties of proteins under high pressure
2010
Fourier transform infrared spectroscopy (FTIR) coupled with High Pressure (HP) techniques is a suitable tool to investigate unfolding/misfolding processes providing useful information on the kinetics of aggregation of proteins[1]. Since HP affects only the volume contribution to the Gibbs free energy, it is able to perturb the structure of proteins in a reversible way [2][3]. The principle governing pressure effects is that it tends to shift a system towards the state that occupies the smallest volume, it causes the electrostriction of charged and polar groups, the elimination of packing defects, and the solvation of hydrophobic groups. Cavities and packing defects are expected to be major …
Infrared HP study of protein folding and aggregation @ the SISSI Elettra beamline
2010
Fourier transform infrared spectroscopy (FTIR) coupled with High Hydrostatic Pressure technology is a suitable technique to investigate unfolding/misfolding processes providing useful information on the kinetics of aggregation of proteins. Since HHP doesn't affect the enthalpic contribution to the Gibbs free energy, it is able to perturb the secondary structure of proteins in a reversible way . The principle governing pressure effects is that it tends to shift a system towards the state that occupies the smallest volume, it causes the electrostriction of charged and polar groups, the elimination of packing defects, and the solvation of hydrophobic groups. Cavities and packing defects are ex…
FTIR studies of the high pressure dissociation of insulin and alpha-synuclein amyloids
2012
Amyloid fibrils are highly ordered aggregates whose formation occurs during the development of several serious disorders, like Althzeimer's and Parkinson's diseases. Even if most biophysical investigations of fibril formation have attempted to elucidate the structural events that occur during amyloid fibril assembly, relatively little is known about the thermodynamics of the aggregated protein state, and the kinetic mechanisms of its formation. Fibrillation is an irreversible process and a key challenge for the field is the development of therapeutic strategies able to inhibit or reverse the aggregation. The coupling of conventional Fourier Transform Infrared Spectroscopy (FTIR) and high Pr…
Inactivation and polymerization of human neuroserpin
2010
Neuroserpin is an inhibitory enzyme, belonging to the family of serpins and involved in several pathologies, such as ischemia, Alzheimer disease, and FENIB (Familial Encephalopathy with Neuroserpin Inclusion Body). Here, we study the mechanism of neuroserpin inactivation and polymerization by different experimental techniques (static and dynamic light scattering, liquid chromatography, Fourier transform infrared spectroscopy, emission spectroscopy). Our results show that at intermediate temperatures (45-55 °C) neuroserpin forms flexible polymers with a size from a few tens to a few hundreds of nanometers. At high temperatures, above 80 °C, our results reveal a different polymeric form, reac…
Functional and dysfunctional isoforms of human neuroserpin
2015
Neuroserpin (NS) is a serine protease inhibitor (SERPIN) involved in different neurological pathologies, including the Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB), related to the aberrant polymerization of NS mutants. Here we present an in vitro and in silico characterization of native NS and its dysfunctional conformation isoforms: the proteolytically cleaved conformer, the inactive latent conformer, and the polymeric conformer. Using circular dichroism and fluorescence spectroscopy, we present an experimental validation of the latent model and highlight the main structural features of the different conformers. In par- ticular, emission spectra of aromatic residues yi…
Testing e validazione comparativa di coating idrofobizzanti per superfici in gelcoat
2021
Nell’industria delle telecomunicazioni a supporto del settore aerospaziale, il mantenimento dell’efficacia e della sicurezza delle trasmissioni in condizioni ambientali estreme assume un’importanza crescente, in funzione della sempre maggiore diffusione dei siti trasmittenti/riceventi, operativi su scala planetaria. In questa cornice, si richiede che gli elementi a protezione dei dispositivi installati si dimostrino durevoli nel tempo anche quando esposti ad abbondanti precipitazioni, accumuli nevosi continuati o stratificazioni di ghiaccio, e improvvisi shock termici, garantendo nel contempo la fedeltà della trasmissione. Una marcata idrofobicità degli strati esterni delle coperture risult…