A5045922572- Advanced Chemical Physics Studies
- nanoparticles nucleation surface interactions
- Bacteriophages and microbial interactions
- Bacterial Genetics and Biotechnology
- RNA and protein synthesis mechanisms
- Spectroscopy and Quantum Chemical Studies
- Theoretical and Computational Physics
- Electron and X-Ray Spectroscopy Techniques
- DNA and Nucleic Acid Chemistry
- Advanced Electron Microscopy Techniques and Applications
- Atomic and Molecular Physics
- Nanopore and Nanochannel Transport Studies
- Calcium Carbonate Crystallization and Inhibition
- Ion-surface interactions and analysis
- Kidney Stones and Urolithiasis Treatments
- Bone Tissue Engineering Materials
- Nanocluster Synthesis and Applications
- Paleontology and Stratigraphy of Fossils
- Gold and Silver Nanoparticles Synthesis and Applications
- Catalytic Processes in Materials Science
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced biosensing and bioanalysis techniques
- Electrostatics and Colloid Interactions
- Mass Spectrometry Techniques and Applications
- Pediatric Urology and Nephrology Studies
Laboratoire de physique des Solides
2009-2024
Centre National de la Recherche Scientifique
2009-2024
Université Paris-Saclay
2007-2024
Université Paris-Sud
2006-2021
Université Paris Cité
2001-2020
Institut de Biochimie et Biophysique Moléculaire et Cellulaire
2010-2013
Laboratoire Aimé Cotton
1990-2001
Universidad Complutense de Madrid
2001
Unimolecular dissociation channels of mass-selected doubly charged sodium clusters ${\mathrm{Na}}_{\mathit{n}}^{++}$ have been determined for cluster sizes near and above the critical size, ${\mathit{n}}_{\mathit{c}}$=27, from which are detectable in mass spectra. On a time scale 50 \ensuremath{\mu}s with respect to ionization, size n=${\mathit{n}}_{\mathit{c}}$ found fission asymmetrically. For ${\mathit{n}}_{\mathit{c}}$, however, evaporation neutral monomer is dominant channel delayed...
The emergence of chirality is a central issue in chemistry, materials science, and biology. In nanoparticle assemblies, has been shown to arise through few different processes, but chiral organizations composed plate-like nanoparticles, class material under scrutiny due their wide applicative potential, have not yet reported. We show that ribbons stacked board-shaped cadmium selenide (CdSe) nanoplatelets (NPLs) twist upon the addition oleic acid ligand, leading reach several micrometers...
Idiopathic kidney stones originate mainly from calcium phosphate deposits at the tip of renal papillae, known as Randall's plaques (RPs), also detected in most human kidneys without stones. However, little is about mechanisms involved RP formation. The localization and characterization such nanosized objects remain a real challenge, making their study arduous. This provides nanoscale analysis chemical composition morphology incipient RPs, characterizing particular interface between mineral...
Background Pseudoxanthoma elasticum (PXE) is a genetic disease caused by mutations in the ABCC6 gene that result low pyrophosphate levels and subsequent progressive soft tissue calcifications. PXE mainly affects skin, retina, arteries. However, many patients with experience kidney stones. We determined prevalence of this pathology examined possible underlying mechanisms murine models. Methods conducted retrospective study large cohort analyzed urine samples kidneys from Abcc6 −/− mice at...
Energetics and dynamics of Coulombic fission small doubly charged potassium clusters subsequent to the ionization singly ones are investigated experimentally theoretically. Fission is shown occur predominantly via ${\mathrm{K}}_{\mathit{n}}^{++}$\ensuremath{\rightarrow}${\mathrm{K}}_{\mathit{n}\mathrm{\ensuremath{-}}3}^{+}$+${\mathrm{K}}_{3}^{+}$ for 5\ensuremath{\le}n\ensuremath{\le}12. The close correspondence between measured calculated kinetic energy release accompanying process allows a...
Abstract The presence of phosphate from different origins (inorganic, bioorganic) is found more and in calcium carbonate-based biominerals. Phosphate often described as being responsible for the stabilization transient amorphous carbonate phase. In order to specify composition mineral phase deposited at onset carbonated shell formation, present study investigates, down nanoscale, growing European abalone Haliotis tuberculata , using a combination solid state nuclear magnetic resonance,...
Evaporative cooling of internal energy rich potassium cluster ions K+n (5<n<200) is investigated within two well defined but quite different time windows. One the windows starts 1 μs after photoexcitation isolates one step in evaporative cascade. The experimental technique insures complete determination dissociation channels. Tandem time-of-flight mass spectroscopy measures relative rate competing channels from ion fragmentation patterns. corresponding neutral fragments are...
Nucleosome core particles correspond to the structural units of eukaryotic chromatin. They are charged colloids, 101 Å in diameter and 55 length, formed by coiling a 146/147 bp DNA fragment (50 nm) around histone protein octamer. Solutions these can be concentrated, under osmotic pressure, up concentrations found nuclei living cells. In presence monovalent cations (Na + ), nucleosomes self-assemble into crystalline or liquid phases. A lamello-columnar phase is observed at ‘low salt’...
The Coulombic fission of small doubly charged lithium and potassium clusters has been investigated around their critical size stability ${\mathit{n}}_{\mathit{c}}$=25 ${\mathit{n}}_{\mathit{c}}$=21, respectively. Neutral are produced by the gas aggregation technique, photoionized a pulsed laser source mass analyzed in tandem time-of-flight spectrometer. Individual fragmentation channels due to unimolecular dissociation size-selected parents using retarding-field method. In this range it is...
The preferential dissociation channels of singly and doubly charged antimony clusters have been determined from the unimolecular energy rich cluster ions, using an ion stopping technique. It is found that Sb+n with 5≤n≤80 dissociate by loss neutral molecules. Neutral dimer observed for n=5, 6, 7 whereas n≥8, loses Sb4. fragmentation Sb++n has investigated above critical size n++c=24 which are detectable in mass spectra. On time scale experiment, 1 μs≤t≤100 μs respect to photoionization,...
Using centrifugation assay and light scattering measurements, we study the condensation of DNA by salmon protamine, a highly basic protein carrying 21 positive charges out 30 amino acids, in presence high amount monovalent salt. The is followed macroscopic phase separation. It occurs while large polycations remains freely diffusing bulk. A similar behavior was described before for small multivalent ions diluted solution lower salt range. Sensitivity to however amplified when increasing...
The basic proteins, protamines and histones H1, are known to condense DNA in vivo. We examine here their ability solubilize vitro linear [and a synthetic polyanion, Poly(Styrene-Sulfonate) or PSS] at low ionic concentrations by varying the charge concentration ratio. Phase separation is observed very narrow range of ratios for short PSS; on both sides this range, polydisperse charged complexes formed. A inversion detected. For long chains however, different behavior observed: not soluble...