Search

This study investigates the propagation dynamics of plasma streamers in a packed-bed dielectric barrier discharge using a 2D particle-in-cell/Monte Carlo collision model. To accurately simulate the high-intensity discharge and streamer propagation mechanism at atmospheric pressure, additional algorithms for particle merging and a new electron mechanism are incorporated into the traditional particle-in-cell/Monte Carlo collision model. To validate the accuracy of this improved model, qualitative comparisons are made with experimental measurements from the existing literature. The results show that the speed of streamer propagation and the distribution of plasma are strongly influenced by the dielectric constant of the packed pellet, which is commonly used as a catalyst. In cases with a moderate dielectric constant, the presence of a strong electric field between the pellet and dielectric layer on the electrode significantly enhances the discharge. This enables the streamer to propagate swiftly along the pellet surface and results in a wider spread of plasma. Conversely, a very high dielectric constant impedes streamer propagation and leads to localized discharge with high intensity. The improved model algorithms derived from this research offer valuable insights for simulating high-density plasma discharge and optimizing plasma processing applications.

The potential of cold atmospheric plasma (CAP) in biomedical applications has received significant interest, due to its ability to generate reactive oxygen and nitrogen species (RONS). Upon exposure to living cells, CAP triggers alterations in various cellular components, such as the cell membrane. However, the permeation of RONS across nitrated and oxidized membranes remains understudied. To address this gap, we conducted molecular dynamics simulations, to investigate the permeation capabilities of RONS across modified cell membranes. This computational study investigated the translocation processes of less hydrophilic and hydrophilic RONS across the phospholipid bilayer (PLB), with various degrees of oxidation and nitration, and elucidated the impact of RONS on PLB permeability. The simulation results showed that less hydrophilic species, i.e., NO, NO2, N2O4, and O3, have a higher penetration ability through nitro-oxidized PLB compared to hydrophilic RONS, i.e., HNO3, s-cis-HONO, s-trans-HONO, H2O2, HO2, and OH. In particular, nitro-oxidation of PLB, induced by, e.g., cold atmospheric plasma, has minimal impact on the penetration of free energy barriers of less hydrophilic species, while it lowers these barriers for hydrophilic RONS, thereby enhancing their translocation across nitro-oxidized PLB. This research contributes to a better understanding of the translocation abilities of RONS in the field of plasma biomedical applications and highlights the need for further analysis of their role in intracellular signaling pathways.

To meet the needs of the hungry population, it is critical to boost agricultural product production while minimizing contaminated waste. The use of two nonthermal technologies, pulsed electric field (PEF) and nonthermal plasma (NTP), is increasing every day. As both PEF and NTP are relatively newer areas, there is limited knowledge about these two technologies and their modes of action. Studies showed that PEF treatment on the plant seeds helps germination and seedling growth. The positive impact of PEF intensity is highly dependent on the seed coat type and plant species. Another nonthermal technology, NTP, affects seed germination, seedling growth, yield, and resilience to abiotic stress when generated at varying pressures with and without different feed gases. Early germination, germination rate, and germination percentage were all improved when the seedlings were treated with NTP. Similarly to the PEF treatment, NTP had a negative or no effect on germination. This review examined the effects of PEF and NTP on seed germination and analyzed the situation and mechanism behind the positive or negative effect. Deactivation of proteins and enzymes to extend the shelf life of beverages is another prominent application of PEF and NTP. The interaction of PEF and NTP with proteins aids in understanding the microscopic mechanism of these technologies. Therefore, we covered in this review the potential structural and functional changes in proteins/enzymes as a result of PEF and NTP, as well as a comparison of the benefits and drawbacks of these two technologies.

The indole nucleus is an important element of many natural and synthetic molecules with significant biological activity. This review covers some of the relevant and recent achievements in the biological, chemical and pharmacological activity of important indole derivatives in the areas of drug discovery and analysis.

Non-thermal plasmas are emerging as a novel tool for the treatment of living tissues for biological and medical purpose. In this study, we described the effect of 4 min dielectric barrier discharge (DBD) plasma on both T98G cancer and HEK normal cell lines in the presence of different concentrations of osmolytes. This treatment strategy shows a specific inhibitory effect of a 240 s plasma exposure in the presence of osmolytes against T98G brain cancer cells only, but not on HEK normal cells. Based on these interesting properties of osmolytes, a non-thermal plasma appears to be a potential anticancer treatment strategy for different kinds of cancers in the presence of osmolytes.

Four ammonium and imidazolium ionic liquids (ILs) have been synthesized and screened against the T98G cell line (brain cancer) and HEK normal cells. Treatment induced metabolic cell death (MTT), growth inhibition, clonogenic inhibition were studied as cellular response parameters. Treatment with ILs enhanced growth inhibition and cell death in a concentration dependent manner in both the T98G and HEK cell lines. At higher concentrations (>0.09 mg/mL) the cytotoxic effects of the ILs were highly significant. An inhibitory effect on clonogenic capacity was also observed after cell treatment. Amongst all ILs; IL 4 (BMIMCl) exhibited potent activity against T98G brain cancer cells. Despite potent in-vitro activity, all ILs exhibited less cytotoxicity against the normal human HEK cells at all effective concentrations.