Jean-Michel Pouvesle
University of Orléans
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Publication
Featured researches published by Jean-Michel Pouvesle.
International Journal of Cancer | 2012
Marc Vandamme; Eric Robert; Stéphanie Lerondel; Vanessa Sarron; Delphine Ries; Sébastien Dozias; Julien Sobilo; David Gosset; Claudine Kieda; Brigitte Legrain; Jean-Michel Pouvesle; Alain Le Pape
Non‐thermal plasma (NTP) is generated by ionizing neutral gas molecules/atoms leading to a highly reactive gas at ambient temperature containing excited molecules, reactive species and generating transient electric fields. Given its potential to interact with tissue or cells without a significant temperature increase, NTP appears as a promising approach for the treatment of various diseases including cancer. The aim of our study was to evaluate the interest of NTP both in vitro and in vivo. To this end, we evaluated the antitumor activity of NTP in vitro on two human cancer cell lines (glioblastoma U87MG and colorectal carcinoma HCT‐116). Our data showed that NTP generated a large amount of reactive oxygen species (ROS), leading to the formation of DNA damages. This resulted in a multiphase cell cycle arrest and a subsequent apoptosis induction. In addition, in vivo experiments on U87MG bearing mice showed that NTP induced a reduction of bioluminescence and tumor volume as compared to nontreated mice. An induction of apoptosis was also observed together with an accumulation of cells in S phase of the cell cycle suggesting an arrest of tumor proliferation. In conclusion, we demonstrated here that the potential of NTP to generate ROS renders this strategy particularly promising in the context of tumor treatment.
PLOS ONE | 2012
Laura Brullé; Marc Vandamme; Delphine Ries; Eric Martel; Eric Robert; Stéphanie Lerondel; Valérie Trichet; Serge Richard; Jean-Michel Pouvesle; Alain Le Pape
Pancreatic tumors are the gastrointestinal cancer with the worst prognosis in humans and with a survival rate of 5% at 5 years. Nowadays, no chemotherapy has demonstrated efficacy in terms of survival for this cancer. Previous study focused on the development of a new therapy by non thermal plasma showed significant effects on tumor growth for colorectal carcinoma and glioblastoma. To allow targeted treatment, a fibered plasma (Plasma Gun) was developed and its evaluation was performed on an orthotopic mouse model of human pancreatic carcinoma using a MIA PaCa2-luc bioluminescent cell line. The aim of this study was to characterize this pancreatic carcinoma model and to determine the effects of Plasma Gun alone or in combination with gemcitabine. During a 36 days period, quantitative BLI could be used to follow the tumor progression and we demonstrated that plasma gun induced an inhibition of MIA PaCa2-luc cells proliferation in vitro and in vivo and that this effect could be improved by association with gemcitabine possibly thanks to its radiosensitizing properties.
Journal of Physics D | 2008
Binjie Dong; Jean-Marc Bauchire; Jean-Michel Pouvesle; Pierre Magnier; D. Hong
The use of plasmas, created by electric discharges, as aerodynamic actuators has been an exciting research topic for more than ten years. However, investigation of these electric discharges is still incomplete. This paper presents our contribution to the study of a DBD surface discharge. Complementary and coherent electrical, optical and aerodynamic measurements as a function of various parameters and geometries were performed. We measured the influence of the frequency and applied voltage of the discharge on the dissipated power. Experimental data yielded an empirical formula to calculate dissipated power and the energy lost in the dielectric was estimated. The plasma temperatures were also evaluated by spectroscopy emission measurements of N2 molecular bands. The velocity of the airflow induced by the DBD discharge in initially still air was measured as a function of the power dissipated in the discharge for different thicknesses and types of dielectric.
Journal of Physics D | 2000
O. Motret; C. Hibert; Stéphane Pellerin; Jean-Michel Pouvesle
This study was dedicated to the correlation between the rotational temperature and the plasma gas temperature in a non-thermal atmospheric plasma obtained by a dielectric barrier discharge. Different parameters were modified (e.g. gas temperature, molecular fraction) in argon water gas mixtures. The rotational temperature of OH(A) was spectroscopically measured. It is shown that in mixtures mainly composed of atomic species, namely rare gases, the OH(A) rotational temperature is strongly correlated with a gas temperature streamer. In mixed (atomic and molecular) plasmas it seems that the rotational temperature can constitute an approach to the translational energy of heavy particles in the streamer areas.
Journal of Physics D | 2002
Ahmed Khacef; Jean-Marie Cormier; Jean-Michel Pouvesle
It is clearly seen that the application of non-thermal plasmas (NTP) to remove NOx from gas mixture containing a large amount of oxygen (O2) is dominated by NO to NO2 oxidation. Experiments have been conducted using a NTP generated by a nanosecond pulsed dielectric barrier discharge in synthetic exhaust gas, prepared from N2, O2, NO, H2O, and C3H6, over a large range of gas temperature (20-300\r{}C). Results show that the NOx removal rate significantly increased with increasing specific energy deposition. For example, at a temperature of 100\r{}C and an energy deposition of 27 J l-1, 92% of the NO molecules have been removed. The W values for NO is dramatically reduced to values scaling from ≈15 eV at 27 J l-1 down to ≈4 eV at 7 J l-1. NOx removal efficiency around 43% was obtained at a temperature of 260\r{}C and a space velocity of 60 000 h-1 for a specific input energy of 27 J l-1. W values for NOx were less than ≈30 eV. Such treatments in exhaust gas with and without the presence of water vapour induced reactions leading to the production of a large variety of by-products such as acetaldehyde, propylene oxide, formic acid, methyl nitrate, and nitromethane.
Physics of Plasmas | 2015
Eric Robert; Thibault Darny; Sébastien Dozias; Sylvain Iseni; Jean-Michel Pouvesle
Atmospheric pressure plasma propagation inside long dielectric tubes is analyzed for the first time through nonintrusive and nonperturbative time resolved bi-directional electric field (EF) measurements. This study unveils that plasma propagation occurs in a region where longitudinal EF exists ahead the ionization front position usually revealed from plasma emission with ICCD measurement. The ionization front propagation induces the sudden rise of a radial EF component. Both of these EF components have an amplitude of several kV/cm for helium or neon plasmas and are preserved almost constant along a few tens of cm inside a capillary. All these experimental measurements are in excellent agreement with previous model calculations. The key roles of the voltage pulse polarity and of the target nature on the helium flow patterns when plasma jet is emerging in ambient air are documented from Schlieren visualization. The second part of this work is then dedicated to the development of multi jet systems, using tw...
Plasma Sources Science and Technology | 2016
Anne Bourdon; Thibault Darny; François Pechereau; Jean-Michel Pouvesle; Pedro Viegas; Sylvain Iséni; Eric Robert
This paper presents a combined 2D numerical and experimental study of the influence of N 2 admixture on the dynamics of a He–N 2 discharge in the 10 cm long dielectric tube of a plasma gun setup. First, the comparison between experiments and simulations is carried out on the ionization front propagation velocity in the tube. The importance of taking into account a detailed kinetic scheme for the He–N 2 mixture in the simulations to obtain a good agreement with the experiments is put forward. For the μs driven plasma gun, the two-and three-body Penning reactions occurring in the plasma column behind the ionization front, are shown to play a key role on the discharge dynamics. In the experiments and simulations, the significant influence of the amplitude of the applied voltage on the ionization front propagation velocity is observed. As the amount of N 2 varies, simulation results show that the ionization front velocity, depends on a complex coupling between the kinetics of the discharge, the photoionization and the 2D structure of the discharge in the tube. Finally, the time evolution of axial and radial components of the electric field measured by an electro-optic probe set outside the tube are compared with simulation results. A good agreement is obtained on both components of the electric field. In the tube, simulations show that the magnitude of the axial electric field on the discharge axis depends weakly on the amount of N 2 conversely to the magnitude of the off-axis peak electric field. Both, simulations and first measurements in the tube or within the plasma plume show peak electric fields of the order of 45 kV·cm −1 .
Journal of Physics D | 1990
Christophe Cachoncinlle; Jean-Michel Pouvesle; Farzin Davanloo; John J. Coogan; C. B. Collins
The fluorescence from high-pressure argon plasmas (1-30 bar) has been excited with an intense flash X-ray device. For the first time a spectrum from 110 to 700 nm has been recorded under such conditions. The spectra obtained in the UV-VUV were very similar to those recorded with alpha -particle excitation at equivalent pressures. The dominant features were the so-called second and third continua of argon. The visible fluorescence was found to be negligible in comparison with the VUV continua.
Plasma Sources Science and Technology | 2003
Jean-Michel Pouvesle; Eric Robert; T. Gonthiez; R. Viladrosa; J. Pons; O. Sarroukh; Moulay M. Idrissi; B. Métay; Smruti Ranjan Mohanty; C. Fleurier; Christophe Cachoncinlle
There is an increasing use of high energy photons in many fields of research and in industry. Where large installations such as synchrotrons or dedicated laser based source facilities can provide solutions for specific needs, they are presently unable to bring convenient solutions for on-site experiments or industrial processes. Compact discharge based devices appear to be a very interesting response to the demand in many cases. They can provide high photon fluxes in a wide spectral range, from VUV to hard x-rays, covering most of the actual needs. Certainly, they still need a lot of improvement and optimization to meet the most stringent requirements. In this paper, we will present some of the recent results we obtained in that field along with new applications. Among them, we will present our report on the performance of a novel and truly compact xenon-filled fast capillary discharge system which generates radiation mostly in the EUV region (10–16 nm) developed in the framework of an EUV lithography program. We will also present results obtained in the field of hard x-ray generation with a new source capable of producing high dose pulses in quasi-continuous or burst mode at a very high frequency developed for high speed cineradiography.
Journal of Physics D | 2000
Remi Dussart; D. Hong; S. Götze; W. Rosenfeld; J. Pons; R. Viladrosa; Christophe Cachoncinlle; C. Fleurier; Jean-Michel Pouvesle
Time- and space-resolved measurements of an ablative polyethylene capillary discharge using a pinhole camera are presented in this paper. Measurements with and without a 0.1 µm thick polyimide filter allowed us to identify the soft x-ray production zones. The images show that the plasma, mainly composed of highly ionized carbon, was not detached from the capillary wall during the heating phase. This plasma behaviour does not favour the development of a recombination-pumped x-ray laser. For two capillary lengths, the plasma dynamics were observed at constant power density in a first run and at identical current waveform in a second run. In both cases, they were different and could induce errors on gain measurement when varying capillary lengths. To our knowledge, this is the first report of time-resolved pinhole images of ablative carbon capillary discharges used as soft x-ray sources.