New modification of the acoustic Lamb waves and its application for liquid and ice sensing.

Using quartz plates as an example existance of the new modification of the Lamb waves is demonstrated. The waves have small vertical displacement, large shear-horizontal and longitudinal components, and elliptic polarization which is oriented parallel to the plate faces. Numerical calculations of the surface displacements and depth profiles show the particular polarization is maintained at any depth from free faces and for all plate thickness in the range h/λ = 0-1.7 (h - thickness, λ - wave length). Results of the measurements accomplished for four new modes and three plate thickness h/λ confirm that radiation of the waves into adjucent liquid (which is proportional to vertical displacement) is small, while viscoelestic loss of the same the waves (which is proportional to in-plane components) is large. This property makes the modified waves suitable for sensing liquids and ices. In particular, responses of the waves towards liquid viscosity and water-to-ice transformation are larger than those are for common Lamb waves approaching 27 and 50 dB, respectively, at about 30 MHz, 1500 cP, and 10 mm propagation path.

Quasi longitudinal Lamb acoustic modes along ZnO/Si/ZnO structures.

A novel structure consisting of a Si plate sandwiched between two ZnO layers is suggested as propagation medium for Quasi Longitudinal (QL) acoustic Lamb waves. Considering a low-dispersive quasi-longitudinal mode as an example, the phase velocity v, electromechanical coupling constant k2 and mechanical displacements U1, U3 versus plate and ZnO layers thicknesses have been calculated starting from uncoated plate through the same plate with one layer to the plate with two layers onto opposite faces. A remarkable increase in the electromechanical coupling, together with an essential decrease in the vertical displacement U3, at the ZnO surface, have been theoretically demonstrated and experimentally verified for definite combinations of the films/plate thicknesses. This property of the structure is attractive for applications to microwave liquid sensors.

General properties of the acoustic plate modes at different temperatures.

Using acoustic plate modes with SH-polarization and quartz crystal with Euler angles 0°, 132.75°, 90°, as an example, general properties of the acoustic plate modes at different temperatures are studied theoretically and experimentally in the range from -40 to +80°C. It is shown that in addition to well-known parameters responsible for temperature characteristics of acoustic waves the temperature coefficients of the acoustic plate modes depend on the mode order n, plate thickness h/λ, and expansion of the plate in direction of its thickness (h - thickness, λ - acoustic wavelength). These properties permit the mode sensitivity to be increased or decreased without replacing plate material and orientation.

[EMG characteristics of women in respect with phase of the menstrual cycle, season and type of vegetative regulation].

Here we report on the electromyographic (EMG) characteristics of young females (n = 23, 19.9 +/- 1.4 years) under varied environmental and physical conditions: 4 phases of menstrual cycle phase (early and late follicular, ovulation, and luteal), spring and autumn seasons, and type of the vegetative nervous system (VNS) regulation based on the linear and novel non-linear parameters of interference EMG (iEMG) in m. biceps br. Additionally, we characterize activity of motor units of m. triceps br. The major finding was that most of the variables of iEMG and MU activity significantly decreased in the ovulation phase in the spring season. Among types of VNS regulation, the vagotonic type exerted influence on the neuromuscular status of young women.

A variant of the Il2ra / Cd25 gene predisposing to graves' disease is associated with increased levels of soluble interleukin-2 receptor.

Alpha-subunit of the IL-2 receptor (IL-2Rα) encoded by the IL2RA/CD25 gene binds IL-2 that plays a pivotal role in the regulation of T cell function. Levels of a soluble form of IL-2Rα (sIL-2Rα) lacking the transmembrane and cytoplasmic domains were shown to be increased in several autoimmune diseases including Graves' disease (GD). Recent studies showed association between the IL2RA/CD25 gene variants and several autoimmune diseases including GD. In this study, we analyzed whether polymorphic markers rs2104286, rs41295061, and rs11594656 located at the IL2RA/CD25 locus confer susceptibility to GD and are related to increased concentrations of sIL-2Rα. A total of 1474 Russian GD patients and 1609 control subjects were genotyped for rs2104286, rs41295061, and rs11594656 using a Taqman assay. Concentrations of sIL-2Rα in sera of affected and non-affected individuals were measured using an ELISA test. A minor allele A of rs41295061 showed significant association with increased risk of GD [odds ratio (OR) = 1.43, P(c) = 0.00102]. The allele A of rs41295061 and allele A of rs11594656 constitute a higher risk haplotype AA (OR = 1.47, P(c) = 0.0477). Compared to carriers of the protective haplogenotype GT/GT, the carriage of two copies of the haplogenotype AA/AA was associated with elevated levels of sIL-2Rα in both GD patients (AA/AA versus GT/GT: 1.35 ± 0.47 ng/ml versus 1.12 ± 0.45 ng/ml, P = 0.0065) and healthy controls (AA/AA versus GT/GT: 0.67 ± 0.28 ng/ml versus 0.51 ± 0.33 ng/ml, P = 0.0098). This is the first report presenting correlation between the carriage of disease-associated variants of IL2RA/CD25 with increased levels of sIL-2Rα in GD.

[The isolation and determination of different narcotic and drug substances after the acid hydrolysis of biological material. (1)]. / Izolirovanie i opredelenie razlichnykh narkoticheskikh i lekarstvennykh veshchestv posle kislotnogo gidroliza biologicheskogo materiala (soobshchenie 1).

A modified method for isolation of toxicologically significant substances after acid hydrolysis of biological material is proposed. Drugs and narcotics of different groups were identified, which are not disintegrated after acid hydrolysis of biological material and are isolated in high amounts.

[Burst discharges of a single nerve cell induced by korazol and penicillin]. / Zalpovye razriady odinochnoi nervnoi kletki, vyzvannye korazolom i penitsillinom.

The electrical activity of an isolated stretch-receptor neuron of a crayfish was studied under the action of corazol and penicillin by microelectrode techniques. Burst discharges induced by these agents are found to have in their basis the depolarizing shifts of pacemaker origin.

[The effect of limiting neuronal energy metabolism on the level of impulse activity and membrane potentials]. / Vliianie ogranicheniia énergeticheskogo metabolizma neirona na uroven' impul'snoi aktivnosti i membrannogo potentsiala.

The changes of the membrane potential and the frequency of impulse activity of the crayfish stretch receptor neuron have been studied under condition of energy supply deficiency. The energetic metabolism inhibitors have been found not to exert a significant effect on the membrane potential. The activity of the glycolysis process and the Krebs cycle have different effect on the sensitivity of the generating mechanism.