Piezoelectric and dielectric properties of BiTiNbO prepared by hot pressing from powders activated using the serial dilution method.

Bi-based layer structure ferroelectrics are the most promising compounds for the fabrication of high-temperature piezoelectric materials. Studies aiming to develop and optimize the techniques to produce efficient high-density piezoelectric ceramics, and to investigate the effects of ceramics production conditions on their structure and functional properties, have become high-priority objectives of modern piezo-engineering. We applied ultra high dilution (UHD) technology to pre-treat BiTiNbO powders and used hot pressing to prepare perovskite-layer structured ceramic specimens.

[Peculiarities of hemodynamics and heart rhythm in males with increased arterial pressure depending on initial vegetative tone and age.].

Central hemodynamics and vegetative regulation of heart rhythms in males depending on age were studied. To evaluate and estimate vegetative regulation a method of variative pulsometry was used. It was used on the basis of analysis of variable heart rhythm (temporary and spectral).

[The development of biochip to detect anti-cholera antibodies in human blood serum].

The full-scaled agglutinating immunoassay is commonly applied to detect content of antibodies to cholera agent Vibrio cholerae human in blood serum under application of serological diagnostic. The time of analysis implementation amounts to 18 hours. To shorten time of detection of antibodies a biological microchip (biochip) was developed.

[Peculiarities of hemodynamics in junior students with a hereditary history of arterial hypertension during examination stresses].

The functional state ofthe students was investigated on the basis ofchanges in central hemodynamic indices immediately during exams, in dependence on family history of hypertension. The significant variation in the character of the response of systemic hemodynamics, as depending on the stage of examination (preparation, answering the ticket, and after the exam), the dominance of the type of the autonomic nervous system, and the family history of hypertension has been revealed These changes in hemodynamics in students with family history of hypertension were established to be more pronounced and prolonged.

[Heart rhythm variability during neuro-psychological stress].

The paper gives the results of studying heart rhythm variability in medical students during their study at a higher educational establishment with regard to the typological features of the autonomic nervous system. Significant diferences have been found in both the temporal and spectral parameters of heart rhythm in relation to the dominance of the autonomic nervous system and the time of their studies. Analysis of heart rhythm variability could estimate the total activity of regulatory mechanisms and the ratio between the sympathetic and parasympathetic autonomic nervous systems in the students during their study.