Clinical studies of phytogel "Kvertulidon" stomatoprotective action in patients with helicobacter gastritis

Background. To determine the therapeutic and prophylactic effect of oral applications of the Kvertulidon phytogel on the condition of the oral cavity in patients with Helicobacter gastritis. Methods. A total of 28 patients with a diagnosis of gastritis of Helicobacter pylori and 18 healthy individuals were surveyed. Phytogel was used as oral applications for 15 days. Hygiene and dental indices were determined, and the level of biochemical markers of inflammation, dystrophy and defenses in the oral fluid: elastase, catalase, urease, lysozyme activity, MDA content, API index and degree of dysbiosis. Results. A significant increase in all hygienic and dental indices was found in patients with gastritis with a decrease in the level of catalase and lysozyme. Applications of phytogel reduce the activity of elastase, urease, the content of MDA, the degree of dysbiosis and increase the activity of catalase, lysozyme, and the API index. Conclusion. Phytogel "Kvertulidon" has stomatoprotective effect in patients with helicobacter gastritis

Volume cross section of auroral radar backscatter and RMS plasma fluctuations inferred from coherent and incoherent scatter data: a response on backscatter volume parameters

Norway and Finland STARE radar measurements in the eastward auroral electrojet are combined with EISCAT CP-1 measurements of the electron density and electric field vector in the common scattering volume to investigate the variation of the auroral radar volume cross section (VCS) with the flow angle of observations (radar look direction with respect to the <I><B>E</B></I>&times;<I><B>B</I></B> electron drift). The data set available consists of ~6000 points for flow angles of 40–85° and electron drifts between 500 and 2000 m s⁻¹. The EISCAT electron density <I>N(h)</I>-profile data are used to estimate the effective electron density, aspect angle and thickness of the backscattering layer. It is shown that the flow angle variation of the VCS is rather weak, only ~5 dB within the range of the considered flow angles. The VCS values themselves respond almost linearly to the square of both the electron drift velocity magnitude and the effective electron density. By adopting the inferred shape of the VCS variation with the flow angle and the VCS dependence upon wavelength, the relative amplitude of electrostatic electron density fluctuations over all scales is estimated. Inferred values of 2–4 percent react nearly linearly to the electron drift velocity in the range of 500–1000 m s⁻¹ but the rate of increase slows down at electron drifts >1000 m s⁻¹ and density fluctuations of ~5.5 percent due to, perhaps, progressively growing nonlinear wave losses

On auroral dynamics observed by HF radar: 1. Equatorward edge of the afternoon-evening diffuse luminosity belt

International audienceObservations and modelling are presented which illustrate the ability of the Finland CUTLASS HF radar to monitor the afternoon-evening equatorward auroral boundary during weak geomagnetic activity. The subsequent substorm growth phase development was also observed in the late evening sector as a natural continuation of the preceding auroral oval dynamics. Over an 8 h period the CUTLASS Finland radar observed a narrow (in range) and persistent region of auroral F- and (later) E-layer echoes which gradually moved equatorward, consistent with the auroral oval diurnal rotation. This echo region corresponds to the subvisual equatorward edge of the diffuse luminosity belt (SEEL) and the ionospheric footprint of the inner boundary of the electron plasma sheet. The capability of the Finland CUTLASS radar to monitor the E-layer SEEL-echoes is a consequence of the nearly zero E-layer rectilinear aspect angles in a region 5?10° poleward of the radar site. The F-layer echoes are probably the boundary blob echoes. The UHF EISCAT radar was in operation and observed a similar subvisual auroral arc and an F-layer electron density enhancement when it appeared in its antenna beam.Key words: Ionsophere (ionospheric irregularities) · Magnetospheric physics (auroral phenomena; magnetosphere?ionosphere interactions

Instability and Chaos in Non-Linear Wave Interaction: a simple model

We analyze stability of a system which contains an harmonic oscillator non-linearly coupled to its second harmonic, in the presence of a driving force. It is found that there always exists a critical amplitude of the driving force above which a loss of stability appears. The dependence of the critical input power on the physical parameters is analyzed. For a driving force with higher amplitude chaotic behavior is observed. Generalization to interactions which include higher modes is discussed. Keywords: Non-Linear Waves, Stability, Chaos.Comment: 16 pages, 4 figure

HF radar observations of high-aspect angle backscatter from the E-region

International audienceWe present evidence for the observation of high-aspect angle HF radar backscatter from the auroral electrojets, and describe the spectral characteristics of these echoes. Such backscatter is observed at very near ranges where ionospheric refraction is not sufficient to bring the sounding radio waves to orthogonality with the magnetic field; the frequency dependence of this propagation effect is investigated with the Stereo upgrade of the CUTLASS Iceland radar. We term the occurrence of such echoes the "high-aspect angle irregularity region" or HAIR. It is suggested that backscatter is observed at aspect angles as high as 30°, with an aspect sensitivity as low as 1dB deg–1. These echoes are distinguished from normal electrojet backscatter by having low Doppler shifts with an azimuthal dependence that appears more consistent with the direction of the convection electric field than with the expected electron drift direction. This is discussed in terms of the linear theory dispersion relation for electrojet waves. Key words. Ionosphere (ionospheric irregularities; plasma waves and instabilities; auroral ionosphere