Papers by jean-philippe sarrette
Supplemental material, Supplementary_figures for Use of cold-atmospheric plasma in oncology: a co... more Supplemental material, Supplementary_figures for Use of cold-atmospheric plasma in oncology: a concise systematic review by Antoine Dubuc, Paul Monsarrat, François Virard, Nofel Merbahi, Jean-Philippe Sarrette, Sara Laurencin-Dalicieux and Sarah Cousty in Therapeutic Advances in Medical Oncology
Supplemental material, 2018_02_18_Table_S2 for Use of cold-atmospheric plasma in oncology: a conc... more Supplemental material, 2018_02_18_Table_S2 for Use of cold-atmospheric plasma in oncology: a concise systematic review by Antoine Dubuc, Paul Monsarrat, François Virard, Nofel Merbahi, Jean-Philippe Sarrette, Sara Laurencin-Dalicieux and Sarah Cousty in Therapeutic Advances in Medical Oncology
Supplemental material, 2017_02_19_Table_S1 for Use of cold-atmospheric plasma in oncology: a conc... more Supplemental material, 2017_02_19_Table_S1 for Use of cold-atmospheric plasma in oncology: a concise systematic review by Antoine Dubuc, Paul Monsarrat, François Virard, Nofel Merbahi, Jean-Philippe Sarrette, Sara Laurencin-Dalicieux and Sarah Cousty in Therapeutic Advances in Medical Oncology
Plasma Chemistry and Plasma Processing, 2019
Journal of Physics: Conference Series, 2019
Afterglows of R/x%N2 and R/x%(N2-5%H2) (R = Ar or He) flowing microwave discharges are characteri... more Afterglows of R/x%N2 and R/x%(N2-5%H2) (R = Ar or He) flowing microwave discharges are characterized by optical emission spectroscopy. Absolute densities of N-atoms, N2(A) and N2(X,v>13) metastable molecules and N2 + ions and evaluated densities of NH and H are determined after calibration of the N-atom density by NO titration. New results on NH radical and H-atom relative densities are obtained by considering that the excitation of the NH(A) radiative state in the afterglow is produced by N2(X,v>13) + NH collisions. The interest of these results concerns the enhancement of surface nitriding by combined effects of N and H atoms inclusion in afterglow conditions.
Therapeutic Advances in Medical Oncology, 2018
Background:Cold-atmospheric plasma (CAP) is an ionized gas produced at an atmospheric pressure. T... more Background:Cold-atmospheric plasma (CAP) is an ionized gas produced at an atmospheric pressure. The aim of this systematic review is to map the use of CAP in oncology and the implemented methodologies (cell targets, physical parameters, direct or indirect therapies).Methods:PubMed, the International Clinical Trials Registry Platform and Google Scholar were explored until 31 December 2017 for studies regarding the use of plasma treatment in oncology ( in vitro, in vivo, clinical trials).Results:190 original articles were included. Plasma jets are the most-used production systems (72.1%). Helium alone was the most-used gas (35.8%), followed by air (26.3%) and argon (22.1%). Studies were mostly in vitro (94.7%) and concerned direct plasma treatments (84.2%). The most targeted cancer cell lines are human cell lines (87.4%), in particular, in brain cancer (16.3%).Conclusions:This study highlights the multiplicity of means of production and clinical applications of the CAP in oncology. Wh...
Surface and Coatings Technology, 2019
Nitriding in the afterglows can be beneficial in the surface-selective nitridation of oxide mater... more Nitriding in the afterglows can be beneficial in the surface-selective nitridation of oxide materials for the control of surface defects or active sites in electronic devices or catalysts. Here we introduce our results on the nitriding of anatase TiO 2 films in the afterglows of N 2-H 2 microwave plasmas at the substrate temperatures up to 300 °C. We employed optical emission spectroscopy (OES) and X-ray photoemission spectroscopy (XPS) to determine active species in the afterglows and the N species incorporated into the film, respectively. Adding a few percent of H 2 into the N 2 gas flow generates active species such as NH and H atoms in the afterglow region in addition to the N 2-derived active species such as N atoms and excited N 2 species. The XPS results revealed that such changes in the type and densities of active species in the afterglows can significantly enhance the surface nitriding performance. The origin for the enhanced surface nitriding is attributed to the efficient removal of surface oxygen atoms by reactive H atoms via the formation of H 2 O to result in an efficient surface uptake of nitrogen. Our results show that the N 2-H 2 afterglows can be effectively used for a selective surface nitriding of oxide films such as TiO 2 at the relatively low temperature range. KEYWORDS nitriding; anatase TiO 2 ; N 2-H 2 afterglow; microwave plasma; active species; surface nitridation
Surface and Coatings Technology, 2017
We find that surface modification characteristics of TiO 2 using N 2 RF plasma are strongly depen... more We find that surface modification characteristics of TiO 2 using N 2 RF plasma are strongly dependent on the detailed composition of active species in the plasma and the afterglows. The surface nitriding of ALD-grown TiO 2 films in pure N 2 RF afterglows at room temperature (RT) is found to be more effective in the late afterglows than in the early afterglows. Adding a small fraction of H 2 in N 2 results in suppression of surface nitriding, suggesting that the change in the composition of the active species in the afterglows by H 2 is the origin to the suppressed nitriding performance. Here, we present our analysis on the surface chemical composition after the plasma modification as well as the densities of excited species such as N atoms, N 2 (A) and N 2 (X, v) metastable molecules and N 2 + ions in the afterglows of RF N 2 and N 2-H 2 (b5%) at different positions along the downstream by emission spectroscopy. The early afterglow of N 2 changes from a pink to a late afterglow where the N + N recombination is the dominant process with the introduction of H 2. The roles of active species such as N-atoms and N 2 + ions on TiO 2 surface nitriding are found to oppose to each other. We find that N atoms enhance the surface nitriding, while N 2 + ions are likely to deplete the surface-bound N species.
Journal of Analytical Sciences, Methods and Instrumentation, 2015
Early afterglows of Ar-N2 flowing microwave discharges are characterized by optical emission spec... more Early afterglows of Ar-N2 flowing microwave discharges are characterized by optical emission spectroscopy. The N and O atoms, the N2(A) and N2(X, v > 13) metastable molecules and 2 N + ion densities are determined by optical emission spectroscopy after calibration by NO titration for N and O-atoms and measurements of NO and N2 band intensities. For an Ar-xN2 gas mixture with × increasing from 2 to 100% at 4 Torr, 100 Watt and an afterglow time of 3 × 10 −3 s at the 5 liter reactor inlet, it is found densities in the ranges of (2-6) × 10 14 cm −3 for N-atoms, one order of magnitude lower for N2(X, v > 13) and for O-atoms (coming from air impurity), of 10 10-10 11 cm −3 for N2(A) and of 10 8-10 9 cm −3 for 2 N + .
Current Applied Physics, 2017
N 2 afterglows N density N 2 (A) density N 2 (X, v > 13) density N 2 þ density a b s t r a c t Wi... more N 2 afterglows N density N 2 (A) density N 2 (X, v > 13) density N 2 þ density a b s t r a c t With a potential application to surface modification of oxide materials in mind, active species in RF and microwave (UHF) N 2 afterglows were analyzed in our newly designed flowing reactors. For both plasma systems, discharge of N 2 was generated in a long quartz tube with a small diameter (dia. 5e6 mm) and then was directly injected into a chamber with a large diameter of 15e20 cm. The discharge condition was set to be similar between the two systems; the gas pressure, flow rate and the applied power were 6 Torr, 0.6 slm and 100 W, respectively. Under this condition, the residence time at the chamber inlet was (1e3) x 10 À3 s. The RF and UHF afterglows were formed in the chamber with luminous jets from the end of the discharge tube. However, we found that the densities of active species were quite sourcedependent; N and N 2 (A) densities were higher in UHF than in RF in spite of more O-atoms impurity. The origin of such difference is also attributed to the inherent difference in the nature of excitation between the two plasma sources; RF is more vibrational and is longer than UHF.
The European Physical Journal Applied Physics, 2017
N 2 /0-5% H 2 flowing afterglows from Radio Frequency (RF) and High Frequency (HF) sources have b... more N 2 /0-5% H 2 flowing afterglows from Radio Frequency (RF) and High Frequency (HF) sources have been analyzed by optical emission spectroscopy. In similar conditions (pressure 5-6 Torr, flow rate 0.5 slm and power 100 W), it is found in pure N 2 a nearly constant N-atom density from the pink to the late afterglow, which is higher in HF than in RF: (1-2) and 0.4 Â 10 15 cm À3 , respectively. With a N 2 /2% H 2 gas mixture, the early afterglows is changed to a late afterglow with about the same N-atom density for both RF and HF cases: (8-9) Â 10 14 cm À3. Anatase TiO 2 nanocrystals and Atomic Layer Deposition-grown films were exposed to the RF afterglows at room temperature. XPS analysis of the samples has shown that the highest N/Ti ratio of 0.24 can be achieved with the pure N 2 late afterglow. In the HF pure N 2 late afterglow, however, the N/Ti coverage was limited to 0.04 in spite of higher N-atom density. Such differences in the N content between the two RF and HF cases are attributed to the presence of a high O-atom impurity of 2 Â 10 13 cm À3 in HF as compared to that (8 Â 10 11 cm À3) in RF.
Journal of Physics: Conference Series, 2014
View the article online for updates and enhancements. You may also like Microwave air plasmas in ... more View the article online for updates and enhancements. You may also like Microwave air plasmas in capillaries at low pressure I. Self-consistent modeling P Coche, V Guerra and L L Alves-Influence of on-time on increased number density of excited nitrogen atoms downstream of pulse-modulated induction thermal plasmas Yasunori Tanaka, K Hayashi, T Nakamura et al.-Modelling N 2-O 2 plasmas: volume and surface kinetics Vasco Guerra, Antonio Tejero-del-Caz, Carlos D Pintassilgo et al.
Selected Research Papers on Spectroscopy of Nonequilibrium Plasma at Elevated Pressures, 2002
Densities of N, O and H atoms have been determined by NO titration in Ar-N2 and Ar-O2 and by a Ni... more Densities of N, O and H atoms have been determined by NO titration in Ar-N2 and Ar-O2 and by a Ni catalytic probe in Ar-02 and Ar-H2 flowing DC and microwave post-discharges. For similar discharge parameters : tube diameter of 6 mm, gas flow rate of about 1N1 min-1 and pressure of 2-3 Torr, it is found higher densities of N and 0 atoms in the microwave post-discharge than in the D.C. one. About the same values of 0 atom density are obtained by NO titration and by the Ni catalytic probe. Spatial distribution of the atomic species was found homogeneous in the post discharge reactor by the use of a three dimensional hydrodynamic and kinetic model. Absolute densities of H atoms have been obtained in pure H2 post-discharge by the Ni probe.
Nitrogen containing post-discharges at reduced pressure (1-20 Torr) are today widely used in nume... more Nitrogen containing post-discharges at reduced pressure (1-20 Torr) are today widely used in numerous surface treatments such as steel nitriding, modification of wettability or of adhesion properties. In the late afterglow region, the flowing gas is free from agressive charged species but still contains large amounts of reactive species (atoms, metastable and vibrationally excited molecules) flowing at room temperature. For these reasons, flowing afterglows are particularly well suited to the cold sterilization of the medical instrumentation. During the last 15 years, the antibacterial capabilities of nitrogen/oxygen [1-3] and of pure nitrogen flowing afterglows [4-5] have been studied. In this last case, a 6 log reduction of an initial bacterial concentration (i.e. a sterilization) was obtained either at room temperature with a high microwave power (P MW = 300 W) injected in the discharge or for an operating temperature of 60°C with a lower injected microwave power (100 W). For bot...
Biomedical Engineering - Frontiers and Challenges, 2011
Journal of Analytical Sciences, Methods and Instrumentation, 2013
Transmission of N-atoms through small diameters tubes (1.5 and 3 mm internal diameter (i.d) and 9... more Transmission of N-atoms through small diameters tubes (1.5 and 3 mm internal diameter (i.d) and 9, 50 and 80 cm length for silicone tubes, 1.5 mm i.d and 6.5 cm length for stainless steel tubes) has been measured in late N 2 and Ar-N 2 flowing afterglows of microwave plasmas in continuous and pulsed gas injection at a flow rate of 1 and 3 Standard liter by minute (Slm), a gas pressure from 2 to 4 Torr for N 2 and 20 Torr for Ar-1%N 2 and a plasma power from 150 to 300 Watt. From the experimental T N values, it is deduced the γ-destruction probability inside the tube walls as being for the silicon tubes and
Hydrodynamics - Advanced Topics, 2011
Micro-discharges are specific cold filamentary plasma that are generated at atmospheric pressure ... more Micro-discharges are specific cold filamentary plasma that are generated at atmospheric pressure between electrodes stressed by high voltage. As cold plasma or non-thermal plasma, we suggest that the energy of electrons inside the conductive plasma is much higher than the energy of the heaviest particles (molecules and ions). In such kind of plasma, the temperature of the gas remains cold (i.e. more or less equal to the ambient temperature) unlike in the field of thermal plasmas where the gas temperature can reach some thousands of Kelvin. This high level of temperature can be measured for example in plasma torch or in lightning. The conductive channels of micro-discharges are very thin. Their diameters are estimated around some tens of micrometers. This specificity explains their name: micro-discharge. Another of their characteristic is their very fast development. In fact, micro-discharges propagate at velocity that can attain some tens of millimetres per nanosecond i.e. some 10 7 cm.s-1. This very fast velocity is due to the propagation of space charge dominated streamer heads. The space charge inside the streamer head creates a very high electric field in which the electrons are accelerated like in an electron gun. These electrons interact with the gas and create mainly ions and radicals. In fact, the energy distribution of electrons inside streamer heads favours the chemical electron-molecule reactions rather than the elastic electron-molecule collisions. Therefore, micro-discharges are mainly used in order to activate chemical reactions either in the gas volume or on a surface (
Plasma Medicine, 2012
The present paper is devoted to the characterization of the late afterglow region of N2 and Ar-N2... more The present paper is devoted to the characterization of the late afterglow region of N2 and Ar-N2 flowing discharges. Optical emission spectroscopy is used to quantify the concentrations of the chemical species able to interact with microorganisms in the treatment chamber. Herein, we show that the production of nitrogen atoms in the afterglow of a reduced-pressure flowing microwave discharge can be increased using Ar-N2 mixtures instead of pure nitrogen. At 45 cm from the discharge, the maximum concentration of atoms, obtained for the Ar-15%N2 mixture, is 2.2 × 10 21 m-3 at 9 Torr with an injected microwave power PMW of 100 W and 2.9 × 10 21 m-3 at 200 W. Compared with the maximum N atom concentrations obtained in pure nitrogen at 4 Torr, this result corresponds to an increase of 120% at 100 W and 45% at 200 W. We have verified that these results can be obtained while conserving full late afterglow conditions at a temperature equal to the room temperature at 100 W and not exceeding 35°C at 200 W. Under such conditions, the concentrations of the NO(A and B) excited states, formed from the impurities of the flowing gas, are low. For pure nitrogen, the concentration of the N2(A) metastable state was also measured at the end of the pink afterglow, where it is assumed to be maximal; it was 2.5 × 10 16 m-3. Nitrogen atoms are the major reactive species in the late afterglow region. They are believed to be responsible for the antibacterial properties of pure N2 and Ar-N2 flowing afterglows. To verify this assumption, the Ar-15%N2 flowing afterglow was applied to inactivate Escherichia coli bacteria, and the results were compared with previous studies performed in pure nitrogen and using the same microbiological protocol. With 40 min of exposure to Ar-15%N2 afterglow ([N] = 2.9 10 21 m-3) at 32°C, a 6 log decrease of the initial bacteria population was obtained, while the same 6 log reduction could only be reached at 60°C with pure nitrogen afterglow ([N] = 1.0 × 10 21 m-3).
Plasma Processes and Polymers, 2011
... 31062 Toulouse Cedex 9, France E-mail: [email protected] S. Cousty Laboratoir... more ... 31062 Toulouse Cedex 9, France E-mail: [email protected] S. Cousty Laboratoire Parodontites et Maladies GÈnÈrales, FacultÈ de Chirurgie Dentaire, UniversitÈ Paul Sabatier, 3 Chemin des Maraıchers, 31062 Toulouse Cedex 9, France F. Clement LCABIE ...
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Papers by jean-philippe sarrette