Skip to Main content Skip to Navigation
New interface
Theses

Plasmas dans l’eau et aux interfaces

Abstract : Growing interest in biomedical applications of nonthermal plasmas inspires the development of new plasmas sources. Dielectric barrier (DBD) and corona discharges produced in ambient air or in noble gas flow are typically applied. Direct production of plasma in liquids has a great potential for sterilization of liquid substances and extracorporeal blood treatment. The physical mechanisms of discharge formation in liquid medium are not fully understood.The first part of this thesis deals with the initiation and development of the nanosecond discharge in liquid dielectrics (deionized water, ethanol and n-pentane). Time-resolved shadowgraph visualization, optical emission spectroscopy and electrical diagnostics are applied to investigate the discharge formation on point anode.We have shown that depending on the applied voltage amplitude three different scenario can occur in the polar dielectric, namely, cavitation of a bubble, discharge development in the gaseous cavity (bush-like mode) and initiation of the filamentary discharge (tree-like mode) propagating in bulk liquid. Formation of the bush-like and the tree-like discharges is governed by distinct physical mechanisms, resulting in strongly different plasma parameters.In the second part of this work we address the question of how cold atmospheric plasma interacts with living cells in-vitro and in-vivo, and what is the mechanism of plasma induced cell death. Flowcytometry based cell viability assay with two markers AnnexinV (AV) and Propidium iodide (PI), demonstrates a dose dependent induction of the apoptosis for human T lymphocyte (Jurkat) and epithelial (HMEC) cells treated with DBD plasma. In nude mice model, induction of apoptosis and necrosis in dose dependant manner is observed by electron microscopy in thin epidermis sections. Histological analysis shows significant lesions appeared in epidermis, dermis, hypodermis and muscle as a function of treatment duration. Production of hydrogen peroxide in culture medium (PBS) exposed to DBD plasma is measured using selective fluorescent probe (Amplex® Red). Cell viability of human thyroid epithelial (HTori-3) and melanoma (1205Lu) cells demonstrates nonmonotonous dependence on H2O2 concentration. The major role of plasma produced hydrogen peroxide and DBD electric field is suggested.
Complete list of metadata

Cited literature [127 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00998381
Contributor : ABES STAR :  Contact
Submitted on : Monday, June 2, 2014 - 1:15:06 AM
Last modification on : Friday, October 7, 2022 - 3:45:38 AM
Long-term archiving on: : Tuesday, September 2, 2014 - 11:15:22 AM

File

VA2_MARINOV_ILYA_02122013.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00998381, version 1

Citation

Ilya Marinov. Plasmas dans l’eau et aux interfaces. Autre [cond-mat.other]. Université Paris Sud - Paris XI, 2013. Français. ⟨NNT : 2013PA112291⟩. ⟨tel-00998381⟩

Share

Metrics

Record views

523

Files downloads

368