Low temperature (non-thermal, cold) atmospheric plasmas generated by electrical discharges at atmospheric pressure produce strong oxidation and antimicrobial effects and induce other interesting effects in cells and tissues that can be targeted in medicine. These plasmas are efficient sources of radicals and reactive species, often coupled with the effects of electric fields and radiation, and open up many new application opportunities, especially in biomedicine and agriculture. As a result, multiple practical applications based on cold plasma discharges are now being developed, such as water treatment, bio-decontamination and disinfection, surface cleaning and decontamination with impact in dentistry, wound healing and sterilisation, potential cancer therapies, and stimulation of germination and plant growth. Based on the progress in the plasma technology new research fields have been established in recent years: plasma for environmental applications, plasma medicine, and plasma agriculture. However, the exact mechanisms of the biological and chemical effects induced by cold atmospheric plasma discharges are still not fully understood. The plasma effects to cells and tissues are often indirectly mediated through liquids, so called plasma activated water or other media. Interaction of plasmas with liquids is a novel avenue of research, which greatly contributes to more complex understanding of the interaction of cold plasmas with complex biological systems.

The Faculty of Mathematics, Physics and Informatics of Comenius University in Bratislava is currently seeking highly qualified applicants for 4-year doctoral programmes. The following topics are offered in the group of Environmental and Biomedical Plasma Applications (Division of Environmental Physics, supervised by prof. Zdenko Machala, prof. Karol Hensel, and prof. Mario Janda):

1) Investigation of plasma-liquid interactions in aerosols and bulk liquids by advanced optical/electrical diagnostics and related properties of the plasma activated water
Objectives:
experimental investigations and spectroscopic measurements of the gaseous plasma active species,
their transport into the liquid through plasma-liquid interface depending on the surface/volume ratio – effect of droplet size and density and their high-speed visualization, the species lifetimes and solubility,
analysis of active species in the liquid and their reactions by absorption and fluorescence spectroscopy,
in-situ diagnostics of the plasma-liquid interface.
PhD. in plasma physics, optics, or environmental physics programmes. The potential candidate should be an enthusiastic person with a solid knowledge and experience with experimental physics.

2) Direct vs. indirect effects of cold plasmas and plasma activated water on microorganisms and eukaryotic cells
Objectives:
experimental investigations of the roles of various plasma agents (reactive oxygen and nitrogen species (RONS), ions, strong electric field, UV radiation, heat) in various plasma-liquid-cell systems of several types of plasma discharges;
separation of single and multiple plasma agents, focus at possible synergistic effects (e.g. how cell membrane permeabilization by electric fields couples with the effects of reactive species)
measurements of various RONS in plasma activated liquids, their time evolutions, secondary reactions and long-term effects on selected microorganisms and eukaryotic cells.
PhD. in plasma physics, biophysics, or environmental physics programmes. The potential candidate should be an enthusiastic person with a solid knowledge and experience with experimental physics or chemistry or biology.

3) Investigation of the effects of reactive plasma species in cells using molecular and genetic methods
Objectives:
Experimental investigations reactive plasma species in gas and liquids as inducers of oxidative stress or apoptotic triggers using genetic methods and oxidative stress markers
Influence of the plasma agents to viability, metabolic activity, cell cycle and other cell functions of selected cells in vitro – elucidating the selectivity between normal vs. cancerous cells as a potential cancer therapy
Plasma enhanced gene transfer tests in microorganisms
PhD. in biophysics programme. The potential candidate should be an enthusiastic person with a solid knowledge and experience with experimental biophysics or biochemistry or biology/biomedicine. Collaboration with Dept. of Biochemistry / Institute of Medical Biology and Genetics / Institute of Molecular Biomedicine (Comenius University).

4) Investigating new possibilities of the use of cold plasma in food processing and agriculture
Objectives:
Investigations of cold plasma pasteurization of fruit juices – microbial inactivation, examining chemical and nutrition properties
Seed germination and plant growth stimulation by plasma activated water
Scale-up of plasma systems to pilot scale industrial tests
Exploring possibilities of the use of plasmas and plasma activated water as a surrogate for pesticides or synthetic fertilizers
PhD. in plasma physics, biophysics, or environmental physics programmes. The potential candidate should be an enthusiastic person with a solid knowledge and experience with experimental physics or agriculture/food engineering or plant biology.

The prospective PhD researchers will work in the dynamic multi-disciplinary research group conducting studies at the frontiers of low-temperature plasma science and medicine/engineering (plasma for biomedical and agricultural applications). No previous practical experience in working with non-thermal plasma is required; however, it is desirable for potential applicants to have laboratory research experience. The minimal requirements include a completed Master level degree in the intended area of study or a closely related area.

The applicants are recommended to send their CV with the list publications (if any) and their selection of the proposed topic (1-4) to prof. Zdenko Machala () before Apr 25, 2017.

More details on PhD. studies at the Faculty of Mathematics, Physics and Informatics of Comenius University in Bratislava can be found at https://fmph.uniba.sk/en/admissions/doktorandske-studium/ The most qualified applicants receive a tax-free monthly stipend of 567.50 EUR, increased to 661.50 EUR upon successful completion of their dissertation exam (usually by the end of their second year).