[Prospects and peculiarities of the procedure of ultrasound ablation of subcutaneous veins of the lower limbs]. / Perspektivy i osobennosti tekhnologii ul'trazvukovoi obliteratsii podkozhnykh ven nizhnikh konechnostei.

The last decade has seen active development of minimally invasive (endovenous) methods of surgical removal of lower limb varicose veins (LLVV); however, the problem of increasing efficacy of these methods and improving long-term results still remains of current importance. The authors of this work propose a method of ultrasound ablation of subcutaneous veins of lower extremities. Our experimental study was aimed at determining the pattern of venous wall damage after ultrasound exposure. Samples of segments of the trunk of the great saphenous vein (GSV) were divided into 5 groups: group 1 - the control group, group 2 - treatment with a sclerosant in the amount of 0.3 ml for 30 s, group 3 - treatment with ultrasound at a frequency of 26 kHz and amplitude 40 µm and 0.3-ml sclerosant for 30 s, group 4 - exposure to ultrasound at a frequency of 26 kHz and amplitude 40 µm and 0.3-ml sclerosant for 60 s, group 5 samples were exposed to ultrasound at 26 kHz and amplitude of 40 µm for 60 s. The results of analysing the histological sections of the samples of the 2nd and 3rd groups demonstrated that the degree of alteration in the GSV wall on combined exposure to ultrasound and a sclerosant was 4.5-fold higher as compared with treatment with a sclerosant solution alone. During ultrasound exposure, the maximum temperature of the venous wall of group 5 samples was by 20 °C higher than in samples of group 4. Analysing the histological sections demonstrated a similar pattern of structural alterations of the samples of group 4 and 5, thus suggesting a possibility of controlling the temperature of the venous wall during ultrasound ablation without changing quality of structural lesions. The obtained findings showed a possibility of initiating irreversible dystrophic alterations in the venous wall on exposure to ultrasound by means of combining the mechanisms of chemical, mechanical, and thermal ablation.

[Effect of mechanical stress on lon mutant strain of Escherichia coli K-12]. / Vliianie mekhanicheskikh kolebanii na zhiznedeiatel'nost' lon-mutantnogo shtamma Escherichia coli K-12.

It was found that, depending on their frequency, mechanical vibrations (MVs) can either stimulate (4 Hz) or inhibit (50 Hz) the growth and the division of the lon mutant of Escherichia coli K-12. Similar effects were observed when the MV-treated nutrient medium was inoculated with untreated mutant cells. MVs enhanced the motility of mutant cells and the fragmentation of filament cells always present in the populations of lon mutants.

[Problem of evaluation of impulse noise by the impulse-background criterion]. / K voprosu ob otsenke impul'snogo shuma po kriteriiu impul's-fon.

The article narrates on the study of the impulse-background index evaluated as the difference between the levels measured with a phonemeter at the 'impulse' ('I') and 'slow' ('S') temporal characteristics and within the noise impulses' amplitude-temporal parameters. It was established that delta L was the function of both the amplitude and the impulse duration. If the impulse duration was commensurable with the constant 'S',--delta L was regularly less than 7 dBa irrespective of the actual 'impulse-background' correlation. Expositions of the noises with equal delta L and different amplitude-temporal characteristics were performed with a group of volunteers and resulted in different biologic effects. It was suggested that the delta L evaluation technique proposed by the existing hygienic standards was inadequate and needed reconsideration.