Seeds of cereals (spring and winter wheat, winter triticale, and winter rye) were treated with products of surface barrier discharge plasma for various times (30 and 60 min) on exposure...

Cold argon plasma (CAP) and metal oxide nanoparticles are well known antimicrobial agents. In the current study, on an example of Escherichia coli, a series of analyses was performed to assess the antibacterial action of the combination of these agents and to evaluate the possibility of using cerium oxide and cerium fluoride nanoparticles for a combined treatment of bacterial diseases. The joint effect of the combination of cold argon plasma and several metal oxide and fluoride nanoparticles (CeO₂, CeF₃, WO₃) was investigated on a model of E. coli colony growth on agar plates. The mutagenic effect of different CAP and nanoparticle combinations on bacterial DNA was investigated, by means of a blue–white colony assay and RAPD-PCR. The effect on cell wall damage, using atomic force microscopy, was also studied. The results obtained demonstrate that the combination of CAP and redox-active metal oxide nanoparticles (RAMON) effectively inhibits bacterial growth, providing a synergistic antimicrobial effect exceeding that of any of the agents alone. The combination of CAP and CeF₃ was shown to be the most effective mutagen against plasmid DNA, and the combination of CAP and WO₃ was the most effective against bacterial genomic DNA. The analysis of direct cell wall damage by atomic force microscopy showed the combination of CAP and CeF₃ to be the most effective antimicrobial agent. The combination of CAP and redox-active metal oxide or metal fluoride nanoparticles has a strong synergistic antimicrobial effect on bacterial growth, resulting in plasmid and genomic DNA damage and cell wall damage. For the first time, a strong antimicrobial and DNA-damaging effect of CeF₃ nanoparticles has been demonstrated.

An experimental study of the velocity field in a three-electrode arrangement of a plasma-chemical surface dielectric barrier discharge (SDBD) reactor designed for plant seed’s treatment was carried out. The effect of polarity and magnitude of the extraction voltage (potential of the third electrode), configuration of the SDBD system (5- and 10-mm distances between the strips were observed) and the permeability for gas flow of the third electrode (in the form of a plate or a grid) on the magnitude of the extraction ion current, and induced gas flow structure were analyzed. It is shown that the most uniform flow in the direction of the third electrode, necessary for uniform seed treatment, is achieved in the case of a permeable third electrode under positive displacement potential, opposing a surface discharge electrodes with a distance between the strips much less than the gap dimensions (5 mm between the strips with 10 mm between the third electrode and the barrier surface).

The erosion of nanostructured tungsten and titanium by high-heat plasma flux, laser, and arcing is investigated. To fabricate nanostructural fuzz layers and hierarchical granularity on the surfaces, samples were exposed to helium plasma in the steady-state plasma device PLM-M, which is a linear plasma trap of an eight-pole multicusp magnetic field with parameters similar to the scrape-off layer and divertor plasma in a tokamak. Arcing ignited with a Nd:YAG laser pulse on the target fuzzy surface in the helium plasma resulted in the melting of fibers and the creation of craters of several microns in depth and several tens of microns in diameter.

This work compares the presowing treatment of winter wheat seeds with a low-temperature plasma, a constant high-voltage electric field, a plant protection disinfectant, and cold hardening on the resistance of seedlings to freezing and their morphophysiological characteristics at the initial stage of germination. Various treatment combinations were considered, including the effect of the disinfectant jointly with low-temperature plasma treatment. The greatest stimulating effect from the point of view of seedlings’ morphophysiological characteristics was achieved when seeds were cold-hardened. The action of low-temperature plasma is noticeable up to the third day of germination. The treatment with the low-temperature plasma of seeds pretreated and not-pretreated with the disinfectant had a similar effect on the morphophysiological characteristics of seedlings. The plasma treatment and the electric field were combined with each other, i.e., the plasma treatment effects were added to the electric field effects. Resistance to low temperatures was increased with the hardening of seeds treated with the electric field and the disinfectant. Resistance to low temperatures was reduced when treated with the electric field and/or low-temperature plasma after being treated with the disinfectant.