The study of the negative pion production in neutron-proton collisions at beam momenta below 1.8 GeV/c

A detailed investigation of the reaction np -> pp\pi^{-} has been carried out using the data obtained with the continuous neutron beam produced by charge exchange scattering of protons off a deuterium target. A partial wave event-by-event based maximum likelihood analysis was applied to determine contributions of different partial waves to the pion production process. The combined analysis of the np -> pp\pi^{-} and pp -> pp\pi^{0} data measured in the same energy region allows us to determine the contribution of isoscalar partial waves (I=0) in the momentum range from 1.1 up to 1.8 GeV/c. The decay of isoscalar partial waves into (^1S_0)_{pp}\pi$ channel provides a good tool for a determination of the pp S-wave scalar scattering length in the final state which was found to be a_{pp}=-7.5\pm 0.3 fm.Comment: 6 pages, 6 figure

Modern heating facility for research into the mid-latitude ionosphere

© Meandros Medical and Dental Journal. The development of new devices for research in physics of the upper atmosphere and near-Earth space, which can be used to carry out controlled experiments on the modification of the ionosphere by powerful short-wave radiation, is an urgent task of modern solar-terrestrial physics, space weather, operation of satellite constellations in near-Earth space, radio communications, and radar. The paper describes a modern heating facility, created within the framework of the National Heliogeophysical Complex of the Russian Academy of Sciences. We review the tasks facing the heater, discuss its main technical characteristics, and describe the capability of the observational infrastructure surrounding the heating facility. The paper justifies the long-term benefits of the development of a heating facility at middle latitudes of Eastern Siberia, which can radiate in a frequency range 2.5-6.0 MHz with an effective power of the order of several hundred megawatts. It is important that the heater will be surrounded by such multifunctional instruments as the modern incoherent scatter radar, mesostratospheric lidar, observational systems that can provide a wide range of possibilities for diagnosing artificial plasma disturbances and artificial airglow structures

A study of antimicrobial activity of polyphenols derived from wood.

Due to the spreading and increasing drug resistance of pathogens, the search for novel antibiotics is becoming ever more important. Plant-derived polyphenols are a vast and promising class of compounds with a potential to fight infectious diseases. Still, they are not routinely used in clinical practice. No reports on the in vivo studies of these compounds have been presented. The aim of our work was to compare the antimicrobial activity of resveratrol (stilbene), dihydroquercetin and dihydromyricetin (flavonols) extracted from the bark and wood of conifers against the dermatophytes Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Using the radial diffusion assay, we established that dihydroquercetin, resveratrol and dihydromyricetin exhibit high activity against S. aureus even at the smallest possible concentrations of 0.22, 0.15, and 0.15 mM, respectively. In contrast, the highest achievable concentrations of these compounds in the solutions (21.5, 15.5 and 15.0 mM for dihydroquercetin, resveratrol and dihydromyricetin, respectively) have no effect on the growth of P. aeruginosa and C. albicans. These findings suggest that polyphenols derived from conifers could have a potential to be used as a medicine for topical application to treat bacterial infections of the skin caused by S. aureus