Efficiency of ultrasonic treatment of polysaccharide from brown algae

Ultrasonic exposure can be used for depolymerization of brown algae polysaccharides. However, its effectiveness depends on several factors, including cavitation activity in the treatment medium. Therefore, the purpose of the work was to determine the cavitation activity and the effectiveness of the ultrasonic exposure to fucoidan in order to optimize the processing processes of polysaccharide from brown algae. A change in cavitation activity was revealed depending on the composition of the processing environment, as well as on the intensity of ultrasonic exposure with a constant frequency of the ultrasonic wave. Similar dynamics of change of cavitation activity were established at the intensity of ultrasonic treatment of 100 and 133 W/cm2 with amplification of electric signal at the increase of ultrasound intensity. The use of SDS in the processing medium led to an increase in cavitation activity to 14.9±0.47 mV. Treatment of the fucoidan solution for 40 minutes under various conditions allowed to obtain fractions with a change in the average hydrodynamic particle diameter from 113 nm (100 W/cm2) to 85 nm (200 W/cm2) and 124 nm (SDS).

Electrochemical deposition of tin-copper alloy coatings

Solderable tin-base alloy coatings are widely used when assembling electronic products. The reorientation of production to lead-free technologies sets the task of developing new technological processes for the formation of coatings for electrical contacts with stable electrical properties, high soldering ability, which lasts for a long time. The features of the process of electrodeposition of coatings with a tin-copper alloy were experimentally investigated and the regularities of the influence of the electrolyte composition, current density, and ultrasound intensity on the cathode current efficiency of the alloy, the deposition rate, elemental composition, structure and functional properties of the precipitation were established. For sonochemical treatment an experimental setup developed at Research Laboratory 5.2 of BSUIR, which makes it possible to vary the intensity of ultrasonic vibrations in the range of 0.058– 1.7 W/cm2 , was used. It has been established that the use of ultrasound changes the formation mechanism of the electrochemical alloy, reduces cathodic polarization, increases the value of the limiting current and makes it possible to control the composition and structure of the precipitates. With an increase in the intensity from 0.12 to 0.95 W/cm2 the amount of copper in the coating increases by 4.5 times. The spreading coefficient of the solder is 92.59–98.44 %.

Extracorporeal ultrasound exposure by the low-frequency acoustic amplitude-modulated signal on a ureteral stent for preventing its incrustation: experimental determination of optimal application points

Introduction. Incrustation and biofilms formation on the surface of ureteral stents are still the most significant complications of internal drainage of the upper urinary tract. There are much researchers conducted to combat these complications. The lack of a solution to this problem affects the ultimate results of treatment and economic losses. The issue of impact by physical methods on the ureteral stent, particularly the use of extracorporeal ultrasound acoustic exposure remains, promising and poorly covered.Purpose of the study. To determine the optimal application points of extracorporeal acoustic exposure by the low-frequency ultrasonic amplitude-modulated signal on a ureteral stent in an experiment.Materials and methods. The original device was designed. The main principle of its operation is the generation of an amplitude-modulated ultrasonic signal in two modes: pulsed and permanent. A sexually mature mongrel dog was an experimental animal. The ureteral stent was placed by laparotomy and cystotomy. Intraoperatively, the emitter of the developed device was applied to the skin of the animal, according to the previously indicated topographic and anatomical landmarks. At the same time, an ultrasonic wave noise analyzer was applied through the laparotomy wound to the appropriate level of the ureter. Measurements of ultrasound intensity indicators were performed three times in two operating modes of the device.Results. Pulsed mode: for the ureteral upper third, the highest ultrasonic intensity (123.67 dB) was achieved along the posterior axillary line. For the ureteral middle third, the best ultrasound intensity (115 dB) was obtained by the posterior axillary line. For the ureteral lower third, the highest ultrasound intensity (113.67 dB) was noted along the middle axillary line.Permanent mode: the best ultrasonic intensity in the projection of the ureteral upper, middle, and lower thirds was achieved along the posterior axillary line and was 118.67 dB, 117 dB and 116.67 dB, accordingly. However, there was an excessive heat effect, manifested by hyperemia and hyperthermia of the animal's skin, fascicular muscle contractions during the instrument functioned in the permanent mode, which can potentially lead to thermal burns and intolerance to the procedure.Conclusion. The pulsed mode of the device function is most safe. The optimal application points of the instrument emitter for the ureteral upper and middle thirds is the posterior axillary line, and for the ureteral lower third is the middle axillary line.

Microscale concert hall acoustics to produce uniform ultrasound stimulation for targeted sonogenetics in hsTRPA1-transfected cells

The field of ultrasound neuromodulation has rapidly developed over the past decade, a consequence of the discovery of strain-sensitive structures in the membrane and organelles of cells extending into the brain, heart, and other organs. Notably, clinical trials are underway for treating epilepsy using focused ultrasound to elicit an organized local electrical response. A key limitation to this approach is the formation of standing waves within the skull. In standing acoustic waves, the maximum ultrasound intensity spatially varies from near zero to double the mean in one half a wavelength, and can lead to localized tissue damage and disruption of normal brain function while attempting to evoke a broader response. This phenomenon also produces a large spatial variation in the actual ultrasound exposure in tissue, leading to heterogeneous results and challenges with interpreting these effects. One approach to overcome this limitation is presented herein: transducer-mounted diffusers that result in spatiotemporally incoherent ultrasound. The signal is numerically and experimentally quantified in an enclosed domain with and without the diffuser. Specifically, we show that adding the diffuser leads to a two-fold increase in ultrasound responsiveness of hsTRPA1 transfected HEK cells. Furthermore, we demonstrate the diffuser allow us to produce an uniform spatial distribution of pressure in the rodent skull. Collectively, we propose that our approach leads to a means to deliver uniform ultrasound into irregular cavities for sonogenetics.

Investigating the Kinetics of Blood Coagulation Using High-Frequency Ultrasound

Blood circulation requires regulated clot formation and breakdown to prevent blood loss following an injury and to ensure that clots do not form and circulate within the vasculature. Known as hemostasis, this delicate balance between coagulant and anti-coagulant pathways can be disrupted by disease, medication, or trauma, and may lead to morbidity or mortality. Current in vitro hemostatic tests have shown promise as tools for diagnosis and risk assessment in certain disorders. However, these tests are limited in their ability to assess the complete hemostatic process or are restricted to studies of blood plasma. In this work, high frequency ultrasound is proposed as a method of assessing hemostasis in whole blood samples. A system was developed and experiments were performed by monitoring acoustic changes in mouse blood during coagulation. Blood cell motion and frequency dependant changes in ultrasound intensity were found to be sensitive to the kinetics of clot formation

Investigating the Kinetics of Blood Coagulation Using High-Frequency Ultrasound

Blood circulation requires regulated clot formation and breakdown to prevent blood loss following an injury and to ensure that clots do not form and circulate within the vasculature. Known as hemostasis, this delicate balance between coagulant and anti-coagulant pathways can be disrupted by disease, medication, or trauma, and may lead to morbidity or mortality. Current in vitro hemostatic tests have shown promise as tools for diagnosis and risk assessment in certain disorders. However, these tests are limited in their ability to assess the complete hemostatic process or are restricted to studies of blood plasma. In this work, high frequency ultrasound is proposed as a method of assessing hemostasis in whole blood samples. A system was developed and experiments were performed by monitoring acoustic changes in mouse blood during coagulation. Blood cell motion and frequency dependant changes in ultrasound intensity were found to be sensitive to the kinetics of clot formation