The permittivity – thickness relationship of a PMN (111) single crystal

In this work, the permittivity measurements of lead magnoniobate PMN (111) single crystals with thicknesses of 400 µm, 25 µm and 10 µm have been carried out at a frequency of 0.1 Hz. The samples in the form of plane-parallel plates were prepared by hand grinding and then their sides were coated with 80 nm Cr-Au electrodes. The topography of the sample surfaces was controlled by AFM. The temperature dependences of the complex permittivity were obtained in the range from 150 to 350 K. The changes in the temperature dependences of ε with varying the thickness of the single crystals were analyzed. The peak on the temperature curve of ε' was shown to shift to a higher temperature with a decrease in the sample’s thickness, and its width increasing significantly. A phenomenological expression was proposed to describe the permittivity ‒ thickness relationship of a single crystal

Thermally excited flow in a microsized liquid crystal cavity

Nonmechanical pumping has been investigated as a liquid crystal device, based on the interplay between the structure of liquid crystal phase (director field), velocity field, heat flow and electric field. The mesogen occupies a homogeneously-aligned liquid crystal (HALC) cavity, delimited by two infinitely long, charged horizontal and coaxial cylinders. A uniform heat flow is applied radially, from the inner cylinder to the outer (colder) one, kept at a constant temperature; the radially directed electrostatic field results from the two electric double layers, i.e. shielding cylindrical layers that are naturally created within the liquid crystal (LC) near a charged surface. Calculations, based on the appropriate nonlinear extension of the classical Ericksen–Leslie theory, show that, under the influence of the uniform heat flow, the HALC material starts moving in the horizontal direction. After switching off the heat flow, the HALC material settles down to rest, and the temperature field across the LC cavity finally drops to the value imposed on the outer (colder) boundary. As for the nematogenic material, we have considered the HALC cavity to be occupied by 4-n-pentyl-40-cyanobiphenyl, and investigated the role of the bounding cylinders in the evolution processes of both the velocity and the thermomechanical shear stress tensor component to their equilibrium distributions across the cavity, for one heating regime and a number of anchoring conditions

An open-label, multicentre, randomized comparative study of efficacy, safety and tolerability of the 5 plant - extract BNO 1012 in the Delayed Antibiotic Prescription Method in children, aged 6 to 11 years with acute viral and post-viral rhinosinusitis

Acute rhinosinusitis (ARS) can be characterized as bacterial (ABRS) and require antibiotic therapy only in 0.5–5% of cases. In most cases, the disease is in a viral and post-viral form, which requires pathogenetic and symptomatic treatment. The study objective was to determine the efficacy of BNO 1012 extract in the technology of delayed antibiotic prescribing in children with acute rhinosinusitis. Methods: 292 children aged 6 to 11 years with ARS were randomized in the multicenter, comparative study. They received an extract of five medicinal plants in addition to standard symptomatic therapy or standard therapy only. Evaluation criteria: reduction of the sinusitis severity according to a 4-point medical assessment scale (nasal congestion, severity of anterior and posterior rhinorrhea) at each visit, dynamics of self-scoring of rhinorrhea and headache (according to a 10-point visual analogue scale), “therapeutic benefit” in days, frequency of antibiotic prescriptions due to the use of an extract of five plants. Results: The use of the 5-plant extract BNO 1012 in addition to the standard symptomatic treatment of acute rhinosinusitis provides a clinically significant, adequate reduction in the severity of rhinorrhea, nasal congestion and post-nasal drip, assessed by a physician at V2 (p < 0.005). Significant differences are noted in the patient's self-scoring of rhinorrhea on the second or third day in viral RS, and from the fourth to the eighth day in postviral RS. Symptoms of similar intensity in control group were observed at V3. Thus, in the first week of treatment, the treatment group compared to the control one showed a “therapeutic benefit” of three days. The use of BNO 1012 in patients with acute rhinosinusitis can 1.81-fold reduce the prescription of antibacterial drugs. Conclusion: The combination of five medicinal plants is effective for the treatment of acute rhinosinusitis in children aged 6 to 11 years. Its use provides a significant “therapeutic benefit” when administered in addition to standard symptomatic therapy, reducing the need for antibiotic use