Voltammetry in the Presence of Ultrasound: Sonovoltammetric Detection of Cytochrome c under Very Fast Mass Transport Conditions

A Single High-Intensity Shock Wave Pulse With Microbubbles Opens the Blood-Brain Barrier in Rats

Focused extracorporeal shockwave (FSW), one kind of focused high-intensity pulsed ultrasound, has been shown to induce blood-brain barrier (BBB) opening in targeted brain areas in rat animal models with minimal detrimental effects below threshold intensity levels or iterations. In the current study, we found that the thresholds could be further reduced by the addition of microbubbles (ultrasound contrast agents or UCA; SonoVue). FSW with 2 × 106 MBs/kg of UCA (20% of clinical dosage) at an intensity level of 0.1 (peak positive pressure 5.4 MPa; peak negative pressure -4.2 MPa; energy flux density 0.03 mJ/mm2) resulting in a 100% BBB opening rate without detectable hemorrhage or apoptosis in the brain. Significantly reduced free radical production was found compared with 0.5 MHz focused ultrasound at a peak negative pressure of 0.44 MPa (1% duty cycle and 4 × 107 MBs/kg of UCA). FSW devices offer advantages of commercial availability and high safety, and thus may facilitate future research and applications of focal BBB opening for oncological and pharmacological purposes.

Evolution of Principle and Practice of Electrodeposited Thin Film: A Review on Effect of Temperature and Sonication

This review discusses briefly the important aspects of thin films. The introduction of the article is a summary of evolution of thin films from surface engineering, their deposition methods, and important issues. The fundamental aspects of electrochemical deposition with special emphasis on the effect of temperature on the phase formation have been reviewed briefly. The field of sonoelectrochemistry has been discussed in the paper. The literature regarding the effects of temperature and sonication on the structure and morphology of the deposits and nucleation mechanisms, residual stress, and mechanical properties has also been covered briefly.

TiO2 phytate films as hosts and conduits for cytochrome c electrochemistry

Cytochrome c is accumulated into a film of TiO(2) nanoparticles and phytate by adsorption from an aqueous solution into the mesoporous structure. Stable voltammetric responses and high concentrations of redox protein within the TiO(2) phytate layer can be achieved. Two types of electrode systems are reported with (i) the modified TiO(2) phytate film between electrode and aqueous solution phase and (ii) the modified TiO(2) phytate film buried under a porous gold electrode ('porotrode'). The electrical conductivity of TiO(2) phytate films is measured and compared in the dry and in the wet state. Although in the dry state essentially insulating, the TiO(2) phytate film turns into an electrical conductor (with approximately 4 Omega cm specific resistivity assuming ohmic behaviour) when immersed in aqueous 0.1 M phosphate buffer solution at pH 7. The redox protein cytochrome c is therefore directly connected to the electrode via diffusion and migration of electrons in the three dimensional mesoporous TiO(2) phytate host structure. Electron transfer from cytochrome c to TiO(2) is proposed to be the rate-determining step for this conduction mechanism.

Monte Carlo simulations in generalized isobaric-isothermal ensembles

We present three generalized isobaric-isothermal ensemble Monte Carlo algorithms, which we refer to as the multibaric-multithermal, multibaric-isothermal, and isobaric-multithermal algorithms. These Monte Carlo simulations perform random walks widely in volume space and/or in potential energy space. From only one simulation run, one can calculate isobaric-isothermal-ensemble averages in wide ranges of pressure and temperature. We demonstrate the effectiveness of these algorithms by applying them to the Lennard-Jones 12-6 potential system with 500 particles.