Simulation of positronium plasma by the molecular dynamics method

In this paper, the relaxation properties of a fully ionized, hot, ideal plasma have been studied using the molecular dynamics method. As an example, the classical problem of equalization of the electron and ion temperatures for various mass ratios is considered, the relaxation times for temperatures is determined, and the influence of the number of particles and the type of boundary conditions on the simulation results is studied. The simulation results are compared with the available theoretical results.     

Thin-film deposition by combining plasma jet with spark discharge source at atmospheric pressure

This study demonstrates a method for the deposition of CuO_x thin films by combining atmospheric pressure plasma jet with spark discharge. In this type of discharge source, the bulk copper material of spark discharge electrodes plays the role of a precursor. Copper atoms and particles go through the physical processes of sputtering, evaporation, and further agglomeration and condensation in the plasma jet and on the substrate. The experiments were carried out with and without a combination of discharges. The material coated on the substrate was studied using a scanning electron microscope, Raman spectroscopy, and energy-dispersive X-ray spectroscopy. The characteristics of the set-up and plasma, such as I-V curves, optical emission spectra, and substrate temperature, were also measured. Copper electrodes were examined for erosion by a scanning electron microscope. The results demonstrate that deposits coated by combined discharge show denser and thicker films.     

Innate Immunomodulatory Activity of Cedrol,a Component of Essential Oils Isolated from Juniperus Species

Little is known about the immunomodulatory activity of essential oils isolated from Juniperus species. Thus, we isolated essential oils from the cones and leaves of eight juniper species found in Montana and in Kazakhstan, including J. horizontalis, J. scopolorum, J. communis, J. seravschanica, J. sabina, J. pseudosabina, J. pseudosabina subsp. turkestanica, and J. sibirica. We report here the chemical composition and innate immunomodulatory activity of these essential oils. Compositional analysis of the 16 samples of Juniper essential oils revealed similarities and differences between our analyses and those previously reported for essential oils from this species. Our studies represent the first analysis of essential oils isolated from the cones of four of these Juniper species. Several essential oil samples contained high levels of cedrol, which was fairly unique to three Juniper species from Kazakhstan. We found that these essential oils and pure (+)-cedrol induced intracellular Ca²⁺ mobilization in human neutrophils. Furthermore, pretreatment of human neutrophils and N-formyl peptide receptor 1 and 2 (FPR1 and FPR2) transfected HL60 cells with these essential oils or (+)-cedrol inhibited agonist-induced Ca²⁺ mobilization, suggesting these responses were desensitized by this pretreatment. In support of this conclusion, pretreatment with essential oils from J. seravschanica cones (containing 16.8% cedrol) or pure (+)-cedrol inhibited human neutrophil chemotaxis to N-formyl peptide. Finally, reverse pharmacophore mapping predicted several potential kinase targets for cedrol. Thus, our studies have identified cedrol as a novel neutrophil agonist that can desensitize cells to subsequent stimulation by N-formyl peptide.