Improving the Efficiency of Turning Processing of Heat-Resistant Alloys by Introducing Ultrasonic Field Energy into the Cutting Zone

Studies have been carried out to assess the effectiveness of dry processing by the current preparations from the heat-resistant alloy CN45MVTUBR with mineral ceramic incisors with the introduction of the ultrasound-field energy treatment zone. It has been established that the use of ULTRASOUND in the rough treatment of mineral ceramic tools without coolant allows to reduce the depth of the defective layer in 1.5 times.

α-Fe2O3@Pt heterostructure particles to enable sonodynamic therapy with self-supplied O2 and imaging-guidance

Sonodynamic therapy (SDT), presenting spatial and temporal control of ROS generation triggered by ultrasound field, has attracted considerable attention in tumor treatment. However, its therapeutic efficacy is severely hindered by the intrinsic hypoxia of solid tumor and the lack of smart design in material band structure. Here in study, fine α-Fe2O3 nanoparticles armored with Pt nanocrystals (α-Fe2O3@Pt) was investigated as an alternative SDT agent with ingenious bandgap and structural design. The Schottky barrier, due to its unique heterostructure, suppresses the recombination of sono-induced electrons and holes, enabling superior ROS generation. More importantly, the composite nanoparticles may effectively trigger a reoxygenation phenomenon to supply sufficient content of oxygen, favoring the ROS induction under the hypoxic condition and its extra role played for ultrasound imaging. In consequence, α-Fe2O3@Pt appears to enable effective tumor inhibition with imaging guidance, both in vitro and in vivo. This study has therefore demonstrated a highly potential platform for ultrasound-driven tumor theranostic, which may spark a series of further explorations in therapeutic systems with more rational material design. Graphical Abstract

Focused Ultrasound Neuromodulation On A Multiwell MEA

Background: Microelectrode arrays (MEA) enable the measurement and stimulation of the electrical activity of cultured cells. The integration of other neuromodulation methods will greatly enhance the application range of MEAs to study their effects on neurons. A neuromodulation method that is recently gaining more attention is focused ultrasound neuromodulation (FUS), which has the potential to treat neurological disorders reversibly and precisely. Methods: In this work, we present the integration of a focused ultrasound delivery system with a multi-well MEA plate. Results: The ultrasound delivery system was characterised by ultrasound pressure measurements, and the integration with the MEA plate was modelled with finite-element simulations of acoustic field parameters. The results of the simulations were validated with experimental visualisation of the ultrasound field with Schlieren imaging. In addition, the system was tested on a murine primary hippocampal neuron culture, showing that ultrasound can influence the activity of the neurons. Conclusions: Our system was demonstrated to be suitable for studying the effect of focused ultrasound on neuronal cultures. The system allows reproducible experiments across the wells due to its robustness and simplicity of operation.

Sonoelectrochemical Synthesis of Antibacterial Active Silver Nanoparticles in Rhamnolipid Solution

The results of studies of the synthesis of AgNPs colloidal solutions by cyclic voltammetry (E from +1.0 to −1.0 V) in rhamnolipid (RL) solutions and the use of soluble anodes in the ultrasound field (22 kHz) are presented. It is shown that the algorithm of anodic dissolution—reduction of Ag(I)—nucleation, and formation of AgNPs makes it possible to obtain nanoparticles with the size from 1 nm to 3 nm. It was found that with an increase in the RL concentration from 1 g/L to 4 g/L, the anodic and cathodic currents increase as well as the rate of AgNPs formation, respectively. The rate of nanoparticles formation also increases with an increase in temperature from 20°C to 60°C, and it corresponds to the diffusion-kinetic range of action of this factor. Moreover, the size of AgNPs depends little on the temperature. The character of the UV-Vis pattern of AgNPs colloidal solutions in RL (with an absorption maximum of 415 nm) is the same over a wide range of nanoparticle concentrations. The curves practically do not change in time, which indicate the stability of anodic and cathodic processes during prolonged sonoelectrochemical synthesis. The cyclic voltammetry curves practically do not change in time, which indicate the stability of anodic and cathodic processes during prolonged sonoelectrochemical synthesis. The antimicrobial activity of synthesized AgNPs solutions to strains of Escherichia coli, Candida albicans, and Staphylococcus aureus was established.

An Enhanced Numerical Model to Simulate Nonlinear Continuous Wave Ultrasound Propagation and the Resulting Temperature Response

In this work a nonlinear CW ultrasound field propagation model based on a second-order operator splitting approach is studied and a number of significant enhancements are introduced and implemented. In this model the ultrasound field is calculated and propagated plane by plane and the effects of diffraction, nonlinearity and absorption are applied independently over incremental steps. This work completes the preceding works (Christopher and Parker 1991, Tavakkoli et al. 1998, Zemp et al. 2003, Williams et al. 2006) by introducing an arbitrary source geometry and excitation definition, full diffraction solution, enhanced pressure, enhanced power deposition rate and temperature prediction capabilities. The result is a particularly useful tool in carrying out simulations of high intensity focused ultrasound (HIFU) that includes temperature rise predictions. Comparisons are made with other codes in both linear and nonlinear regimes. Different dynamics of lesion formation are obtained in linear versus nonlinear models, specially at the onset of lesion creation during HIFU exposure.

An Enhanced Numerical Model to Simulate Nonlinear Continuous Wave Ultrasound Propagation and the Resulting Temperature Response

In this work a nonlinear CW ultrasound field propagation model based on a second-order operator splitting approach is studied and a number of significant enhancements are introduced and implemented. In this model the ultrasound field is calculated and propagated plane by plane and the effects of diffraction, nonlinearity and absorption are applied independently over incremental steps. This work completes the preceding works (Christopher and Parker 1991, Tavakkoli et al. 1998, Zemp et al. 2003, Williams et al. 2006) by introducing an arbitrary source geometry and excitation definition, full diffraction solution, enhanced pressure, enhanced power deposition rate and temperature prediction capabilities. The result is a particularly useful tool in carrying out simulations of high intensity focused ultrasound (HIFU) that includes temperature rise predictions. Comparisons are made with other codes in both linear and nonlinear regimes. Different dynamics of lesion formation are obtained in linear versus nonlinear models, specially at the onset of lesion creation during HIFU exposure.