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.
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.
Schlatholter T.,Zernike Institute for Advanced Materials |
Eustache P.,CNRS Orsay Institute for Molecular Science |
Porcel E.,CNRS Orsay Institute for Molecular Science |
Salado D.,CNRS Orsay Institute for Molecular Science |
And 8 more authors.
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/μm) 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. © 2016 Schlathölter et al.
Enjalbert Q.,University Claude Bernard Lyon 1 |
Enjalbert Q.,Institute Lumiere Matiere |
Enjalbert Q.,CNRS Institute of Analytical Sciences |
Girod M.,University Claude Bernard Lyon 1 |
And 15 more authors.
Journal of Pharmaceutical Analysis | Year: 2014
Oral estrogens are directly associated with changes in plasma levels of coagulation proteins. Thus, the detection of any variation in protein concentrations due to estrogen contraceptives, by a simultaneous analysis of both coagulation proteins and estrogens, would be a very informative tool. In the present study, the merit of photo-selected reaction monitoring (SRM), a new analytical tool, was evaluated towards estrogens detection in plasma. Then, SRM and photo-SRM detection modes were combined for the simultaneous analysis of estrogen molecules together with heparin co-factor and factor XIIa, two proteins involved in the coagulation cascade. This study shows that photo-SRM could open new multiplexed analytical routes. © 2014 Xi'an Jiaotong University. Production and hosting by Elsevier B.V. All rights reserved.
Sanader Z.,The Interdisciplinary Center |
Mitric R.,University of Wurzburg |
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.