showing 8 related works from this author
PyDSC: a simple tool to treat differential scanning calorimetry data
2020
AbstractHerein, we describe an open-source, Python-based, script to treat the output of differential scanning calorimetry (DSC) experiments, called pyDSC, available free of charge for download at https://github.com/leonardo-chiappisi/pyDSC under a GNU General Public License v3.0. The main aim of this program is to provide the community with a simple program to analyze raw DSC data. Key features include the correction from spurious signals, and, most importantly, the baseline is computed with a robust, physically consistent approach. We also show that the baseline correction routine implemented in the script is significantly more reproducible than different standard ones proposed by propriet…
Proton dynamics in bacterial spores, a neutron scattering investigation
2014
International audience; Results from first neutron scattering experiments on bacterial spores are reported. The elastic intensities and mean square displacements have a non-linear behaviour as function of temperature, which is in agreement with a model presenting more pronounced variations at around 330 K (57 • C) and 400 K (127 • C). Based on the available literature on thermal properties of bacterial spores, mainly referring to differential scanning calorimetry, they are suggested to be associated to main endothermic transitions induced by coat and/or core bacterial response to heat treatment.
IN13 Backscattering Spectrometer at ILL: Looking for Motions in Biological Macromolecules and Organisms
2008
In 1998, three partner groups (the French institutions Institut de Biologie Structurale and the Leon Brillouin Laboratory and the Italian Istituto Nazionale per la Fisica della Materia, now merged with the Consiglio Nazionale delle Ricerche, INFM-CNR) applied to operate the thermal backscattering spectrometer IN13, at the Institut Laue Langevin, as a French-Italian Collaborative Research Group (CRG). The plan was to have access to a dedicated spectrometer in order to explore how far neutron scattering could contribute to the understanding of dynamics in biological macromolecules: how “flexible” must be a biological object to perform its function?
Anomalous water dynamics in brain: a combined diffusion magnetic resonance imaging and neutron scattering investigation
2019
International audience; Water diffusion is an optimal tool for investigating the architecture of brain tissue on which modern medical diagnostic imaging techniques rely. However, intrinsic tissue heterogeneity causes systematic deviations from pure free-water diffusion behaviour. To date, numerous theoretical and empirical approaches have been proposed to explain the non-Gaussian profile of this process. The aim of this work is to shed light on the physics piloting water diffusion in brain tissue at the micrometre-to-atomic scale. Combined diffusion magnetic resonance imaging and first pioneering neutron scattering experiments on bovine brain tissue have been performed in order to probe dif…
Mobility of a Mononucleotide within a Lipid Matrix: A Neutron Scattering Study
2017
International audience; An essential question in studies on the origins of life is how nucleic acids were first synthesized and then incorporated into compartments about 4 billion years ago. A recent discovery is that guided polymerization within organizing matrices could promote a non-enzymatic condensation reaction allowing the formation of RNA-like polymers, followed by encapsulation in lipid membranes. Here, we used neutron scattering and deuterium labelling to investigate 5'-adenosine monophosphate (AMP) molecules captured in a multilamellar phospholipid matrix. The aim of the research was to determine and compare how mononucleotides are captured and differently organized within matric…
Experimental evidence for a liquid-liquid crossover in deeply cooled confined water.
2014
International audience; In this work we investigate, by means of elastic neutron scattering, the pressure dependence of mean square displacements (MSD) of hydrogen atoms of deeply cooled water confined in the pores of a three-dimensional disordered SiO 2 xerogel; experiments have been performed at 250 and 210 K from atmospheric pressure to 1200 bar. The " pressure anomaly " of supercooled water (i.e., a mean square displacement increase with increasing pressure) is observed in our sample at both temperatures; however, contrary to previous simulation results and to the experimental trend observed in bulk water, the pressure effect is smaller at lower (210 K) than at higher (250 K) temperatur…
Water Dynamics in Neural Tissue
2013
Water dynamics in post-mortem two-years old bovine cerebral right hemisphere has been investigated through Elastic and Quasi-elastic Neutron Scattering. Experimental parameters such as stability in time of the proton dynamics, data reproducibility and changes in the tissues dynamics upon the conservation protocol, cryogenic towards formalin addition, have been carefully investigated. Results are extremely encouraging and comparisons to magnetic resonance imaging findings are discussed.
The effects of pressure on the energy landscape of proteins
2018
AbstractProtein dynamics is characterized by fluctuations among different conformational substates, i.e. the different minima of their energy landscape. At temperatures above ~200 K, these fluctuations lead to a steep increase in the thermal dependence of all dynamical properties, phenomenon known as Protein Dynamical Transition. In spite of the intense studies, little is known about the effects of pressure on these processes, investigated mostly near room temperature. We studied by neutron scattering the dynamics of myoglobin in a wide temperature and pressure range. Our results show that high pressure reduces protein motions, but does not affect the onset temperature for the Protein Dynam…