Institute Lumiere Matiere

Villeurbanne, France

Institute Lumiere Matiere

Villeurbanne, France
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Antoine R.,University Claude Bernard Lyon 1 | Antoine R.,Institute Lumiere Matiere | Enjalbert Q.,University Claude Bernard Lyon 1 | Enjalbert Q.,Institute Lumiere Matiere | And 7 more authors.
Journal of Physical Chemistry Letters | Year: 2014

One-photon multiple ionization is a signature of dynamical electron correlations in atoms and small molecules, as observed in the Auger process when Auger electron emission follows core-shell ionization. In such a process, the high energy needed to remove several electrons is due to the strong Coulombic attraction between the last departing electron(s) and the ionic core. Multiply negatively charged molecules offer the possibility to overcome the Coulombic attraction, opening the way for multielectron photodetachment following valence shell excitation. Here photodetachment studies have been performed on electrosprayed protein polyanions using vacuum ultraviolet synchrotron radiation coupled to a radiofrequency ion trap. Double, triple, and quadruple electron emissions from protein polyanions resulting from single-photon excitation in the valence shell were observed with ionization thresholds below 20 eV photon energy. This suggests the existence of large electronic correlations in proteins between weakly bound electrons standing on distant sites. Besides, the resulting multiradical polyanions appear to be remarkably stable, an important issue in radiobiology. © 2014 American Chemical Society.

PubMed | CNRS Orsay Institute for Molecular Science, University of Groningen, Zernike Institute for Advanced Materials, University Paris - Sud and Institute Lumiere Matiere
Type: | Journal: International journal of nanomedicine | Year: 2016

The use of nanoparticles to enhance the effect of radiation-based cancer treatments is a growing field of study and recently, even nanoparticle-induced improvement of proton therapy performance has been investigated. Aiming at a clinical implementation of this approach, it is essential to characterize the mechanisms underlying the synergistic effects of nanoparticles combined with proton irradiation. In this study, we investigated the effect of platinum- and gadolinium-based nanoparticles on the nanoscale damage induced by a proton beam of therapeutically relevant energy (150 MeV) using plasmid DNA molecular probe. Two conditions of irradiation (0.44 and 3.6 keV/m) were considered to mimic the beam properties at the entrance and at the end of the proton track. We demonstrate that the two metal-containing nanoparticles amplify, in particular, the induction of nanosize damages (>2 nm) which are most lethal for cells. More importantly, this effect is even more pronounced at the end of the proton track. This work gives a new insight into the underlying mechanisms on the nanoscale and indicates that the addition of metal-based nanoparticles is a promising strategy not only to increase the cell killing action of fast protons, but also to improve tumor targeting.

Ouadah N.,University Claude Bernard Lyon 1 | Ouadah N.,Institute Lumiere Matiere | Doussineau T.,University Claude Bernard Lyon 1 | Doussineau T.,Institute Lumiere Matiere | And 8 more authors.
Langmuir | Year: 2013

The relationship between the effective charge of polymer nanoparticles (PNP) in solution and the charge states of ionized particles produced in the gas phase by electrospray ionization was investigated. Charge detection mass spectrometry was used to measure both the mass and charge of individual electrosprayed ions. The effective charges extracted from the measured zeta-potential of PNPs in solution are partially correlated with the average values of charge of PNPs in the gas phase. The correlation between the magnitude of charging of PNPs ions produced in the gas phase with the PNPs surface charge in solution demonstrates that the mass spectrometry-based analysis described in this work is an alternative and promising way for a fast and systematic characterization of charges on colloidal particles. © 2013 American Chemical Society.

Sanader Z.,The Interdisciplinary Center | Mitric R.,University of Würzburg | Bonacic-Koutecky V.,The Interdisciplinary Center | Bonacic-Koutecky V.,Humboldt University of Berlin | And 6 more authors.
Physical Chemistry Chemical Physics | Year: 2014

We present a joint theoretical and experimental study of the structure selective optical properties of cationic and anionic histidine-silver complexes with Ag and Ag3 which were prepared in the gas phase using mass spectroscopy coupled to electrospray ion source. Our TDDFT calculations provide general insight into the nature of electronic excitations at the metal-bioorganic interface that involve π-π* excitation within bioorganic subunits, charge transfer between two subunits and intrametallic excitations. The binding of silver to histidine, one of the most important amino acids, induces red shift in the optical absorption of protonated histidine particularly for anionic species. The presence of the smallest metallic subunit Ag3 increases the intensity of low energy transitions of histidine illustrating a metal cluster-induced enhancement of absorption of biomolecules in hybrid systems. Comparison of calculated absorption spectra with experimental photofragmentation yield provides structural assignment of the measured spectroscopic patterns. Our findings may serve to establish silver-labeling as the tool for the detection of histidine or histidine-tagged proteins. © 2014 the Owner Societies.

Doussineau T.,University Claude Bernard Lyon 1 | Doussineau T.,Institute Lumiere Matiere | Paletto P.,University Claude Bernard Lyon 1 | Paletto P.,Institute Lumiere Matiere | And 4 more authors.
Journal of the American Society for Mass Spectrometry | Year: 2014

Charge detection mass spectrometry in combination with a linear electrostatic ion trap coupled to a continuous wavelength infrared CO2 laser has been used to study the multiphoton dissociation of DNA macromolecular ions. Samples, with masses ranging from 2.23 to 31.5 MDa, include single strand circular M13mp18, double strand circular M13mp18, and double strand linear LambdaPhage DNA fragments. Their activation energies for unimolecular dissociation were determined. Activation energy values slightly increase as a function of the molecular weight. The most important result is the difference between the fragmentations observed for hybridized double-strands and dimers of single strands. © 2014 American Society for Mass Spectrometry.

PubMed | Armenian National Academy of Sciences, University Claude Bernard Lyon 1 and Lawrence Berkeley National Laboratory
Type: | Journal: Chemphyschem : a European journal of chemical physics and physical chemistry | Year: 2016

The influence of Ca codoping on the optical absorption, photo-, radio-, and thermo-luminescence properties of YAlO

Gridin S.,Institute for Scintillation Materials of Ukraine | Gridin S.,Institute Lumiere Matiere | Belsky A.,Institute Lumiere Matiere | Moszynski M.,National Center for Nuclear Research | And 3 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2014

Scintillation properties of CsI:In single crystals have been investigated. Scintillation yield of CsI:In measured with the 24 μs integration time is around 27,000 ph/MeV, reaching the saturation at 0.005 mol% of the activator. However, luminescence yield of CsI:In is close to CsI:Tl scintillation crystals, which is around 60,000 ph/MeV. This difference is explained by the presence of an ultra-long afterglow in CsI:In scintillation pulse. Thermoluminescence studies revealed a stable trap around 240 K that is supposed to be related to millisecond decay components. The best measured energy resolution of (8.5±0.3)% was achieved at 24 μs peaking time for a CsI sample doped with 0.01 mol% of In. Temperature stability of CsI:In radioluminescence intensity was found to be remarkably high. Its X-ray luminescence yield remains stable up to 600 K, whereafter thermal quenching occurs. The latter property gives CsI:In a potential to be used in well logging applications. © 2014 Elsevier B.V.

PubMed | Institute Lumiere Matiere and Dana-Farber Cancer Institute
Type: Journal Article | Journal: Medical physics | Year: 2017

MR-guided radiation therapy is a current and emerging clinical reality. We have designed and tested a silica-based gadolinium chelates nanoparticle (AGuIX) for integration with MR-guided radiation therapy. The AGuIX nanoparticles used in this study are a dual-modality probe with radiosensitization properties and better MRI contrast than current FDA-approved gadolinium chelates. In advance of an approved Phase I clinical trial, we report on the efficacy and safety in multiple animal models and clinically relevant radiation conditions. By modeling our study on current clinic workflows, we show compatibility with modern patient care, thus heightening the translational significance of this research.The dual imaging and therapy functionality of AGuIX was investigated in mice with clinical radiation beams while safety was evaluated in mice, and nonhuman primates after systemic injection of 0.25 mg/g of nanoparticles. MRI/ICP-MS were used to measure tumor uptake and biodistribution. Due to their small size (2-3 nm), AGuIX have good renal clearance (t1/2=19min). We performed in vitro cell uptake quantification and radiosensitization studies (clonogenic assays and DNA damage quantification). In vivo radiation therapy studies were performed with both 6MV and 6MV-FFF clinical radiation beams. Histology was performed to measure the increase in DNA damage in the tumor and to evaluate the toxicity in healthy tissues.In vitro and in vivo results demonstrate statistically significant increase (P < 0.01) in DNA damage, tumor growth supression and survival (+100 days) compared to radiation alone. Negligible toxicity was observed in all of the animal models. The combination of 6MV-FFF/AGuIX demonstrated a substantial dose enhancement compared to 6MV/AGuIX (DEF = 1.36 vs. 1.22) due to the higher proportion of low energy photons.With demonstrated efficacy and negligible toxicity in mice and non-human primates, AGuIX is a biocompatible nanoplatform with strong translational potential for MR-guided radiation therapy.

Moretti F.,Institute Lumiere Matiere | Patton G.,Institute Lumiere Matiere | Belsky A.,Institute Lumiere Matiere | Fasoli M.,University of Milan Bicocca | And 4 more authors.
Journal of Physical Chemistry C | Year: 2014

The role of charge carrier trapping in determining radioluminescence (RL) efficiency increase during prolonged irradiation of scintillators has been studied by using YPO4:Ce,Nd as a model material. The Nd3+ ions act as efficient electron traps minimizing the role of intrinsic defects. Different Nd contents were considered in order to point out the correlation between the trap concentration and the detected RL efficiency dose dependence. RL measurements as a function of temperature clarified the role of the trap thermal stability in determining the shape and the magnitude of such effect. We propose also a model based on trap filling which is able to describe accurately the complex processes which are involved. © 2014 American Chemical Society.

Gridin S.S.,Institute for Scintillation Materials of Ukraine | Belsky A.N.,Institute Lumiere Matiere | Shiran N.V.,Institute for Scintillation Materials of Ukraine | Gektin A.V.,Institute for Scintillation Materials of Ukraine
IEEE Transactions on Nuclear Science | Year: 2014

Radiative relaxation channels and energy losses in In and Tl doped CsI scintillation crystals have been investigated as a function of temperature and excitation conditions to evaluate scintillation efficiency of the activator channel. Two activator concentration series of crystals were grown by the Bridgman method. Temperature dependence of excitation and luminescence spectra were measured under VUV and X-ray excitation; thermostimulated luminescence was also studied. The observed drop of radioluminescence yield of doped CsI crystals at room temperature relative to the pure crystal is explained by the migration losses caused by charge carrier trapping on the activator centers. The energy losses in CsI:A at low temperatures are due to the trapping of charge carriers on different centers: self-trapping of holes and capture of electrons by the activator centers. We suppose that migration energy losses are the main reason for significantly lower luminescence yield of CsI:A at room temperature than that of self-trapped excitons in pure CsI crystal © 2013 IEEE.

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