Effects Of Ultrasonic Stimulation Research Articles

Effects of Ultrasonic Stimulation and Light Intensity on the Growth Rate and Biomass Productivity of Chlorella ellipsoidea in a Closed-Batch Cultivation System

Microalgae exhibit high nutritional value as animal feed in aquatic animal nurseries. Therefore, approaches to enhance biomass productivity are of great economic significance. This study aimed to evaluate the effect of ultrasonic wave stimulation on the specific growth rate and biomass yield of Chlorella ellipsoidea strain TISTR 8260. C. ellipsoidea stimulated by ultrasonic waves at 50 Hz for 1, 5, and 10 min were cultivated in a closed-batch cultivation system with varying light intensities. Data revealed that stimulation for 1 min and rearing at 71.43 μmol m−2 s−1 resulted in the highest biomass productivity and specific growth rates, with averages of 0.89±0.008 g/L/day and 0.59±0.009 per day, respectively. The findings of this study emphasize the usefulness of ultrasonic waves in enhancing the biomass productivity of microalgae.

Effects of ultrasonic stimulation on the transport of different-sized particles in porous media

Seismic waves can influence subsurface fluid and mass transport and can be used for aquifer remediation, carbon dioxide sequestration, and oil production. The influence of particle size on transport was investigated using three particle-size classes in sand-column experiments. For each size class, three flow rates and five ultrasonic powers were used to examine the roles of hydrodynamic force and ultrasonic stimulation. The number of particles captured in porous media (by straining, wedging, fouling and interaction) increased with increasing particle size and decreasing hydrodynamic force. The particle concentration peak and its tailing increased with increasing ultrasonic stimulation, and the effects of ultrasonic stimulation on the transportation and retention of particles were highly dependent upon hydrodynamic force and particle size. In particular, the effects of ultrasonic stimulation on particle transport and release were most obvious at larger hydrodynamic forces, corresponding to larger particle sizes. Furthermore, particle transport was mathematically modelled to identify the intrinsic mechanism of transportation and retention. Mean particle velocity decreased with increasing ultrasonic stimulation for the 10.119 and 14.675-μm particles, while it remained constant with increasing ultrasonic stimulation for the 5.214-μm particles. Furthermore, particle dispersivity increased with increasing ultrasonic stimulation. The deposition rate decreased and the release rate increased with increasing ultrasonic stimulation. These findings highlight various implications for possible particle–ultrasound interactions at the subpore scale.

Inhibitory effect of ultrasonic stimulation on the voltage-dependent potassium currents in rat hippocampal CA1 neurons

BackgroundTranscranial ultrasonic stimulation is a novel noninvasive tool for neuromodulation, and has high spatial resolution and deep penetration. Although it can increase excitation of neurons, its effects on neuron are poorly understood. This study was to evaluate effect of ultrasonic stimulation (US) on neurons in vitro. In this paper, the effect of US on the excitability and voltage-dependent K^{ + } currents of CA1 pyramidal neurons in the rat hippocampus was studied using patch clamp.ResultsOur results suggest that US increased the spontaneous firing rate and inhibited transient outward potassium current ( varvec{I}_{varvec{A}} ) and delayed rectifier potassium current ( varvec{I}_{varvec{K}} ) . Furthermore, US altered the activation of varvec{I}_{varvec{K}} channels, inactivation and recovery properties of varvec{I}_{varvec{A}} channels. After US, the varvec{I}_{varvec{K}} activation curves significantly moved to the negative voltage direction and increased its slope factor. Moreover, the data showed that US moved the inactivation curve of varvec{I}_{varvec{A}} to the negative voltage and increased the slope factor. Besides, US delayed the recovery of varvec{I}_{varvec{A}} channel.ConclusionsOur data indicate that US can increase excitation of neurons by inhibiting potassium currents. Different US decreased the voltage sensitivity of varvec{I}_{varvec{K}} activation differentially. Moreover, the more time is needed for US to make the varvec{I}_{varvec{A}} channels open again after inactivating. US may play a physiological role by inhibiting voltage-dependent potassium currents in neuromodulation. Our research can provide a theoretical basis for the future clinical application of ultrasound in neuromodulation.

Effect of ultrasonic stimulation on particle transport and fate over different lengths of porous media

It is well established that seismic waves traveling through porous media stimulate fluid flow and accelerate particle transport. However, the mechanism remains poorly understood. To quantify the coupling effect of hydrodynamic force, transportation distance, and ultrasonic stimulation on particle transport and fate in porous media, laboratory experiments were conducted using custom-built ultrasonic-controlled soil column equipment. Three column lengths (23 cm, 33 cm, and 43 cm) were selected to examine the influence of transportation distance. Transport experiments were performed with 0 W, 600 W, 1000 W, 1400 W, and 1800 W of applied ultrasound, and flow rates of 0.065 cm/s, 0.130 cm/s, and 0.195 cm/s, to establish the roles of ultrasonic stimulation and hydrodynamic force. The laboratory results suggest that whilst ultrasonic stimulation does inhibit suspended-particle deposition and accelerate deposited-particle release, both hydrodynamic force and transportation distance are the principal controlling factors. The median particle diameter for the peak concentration was approximately 50% of that retained in the soil column. Simulated particle-breakthrough curves using extended traditional filtration theory effectively described the experimental curves, particularly the curves that exhibited a higher tailing concentration.

Effect of Ultrasonic Stimulation on Mechanical Properties of Alginate Beads

In the drug delivery systems using external ultrasonic stimulation to manipulate the drug release from carriers, the effect of the ultrasonic stimulation on drug carriers should be investigated. Alginate beads were fabricated using a conventional extrusion method, and their shear moduli were calculated by a compression test and the hertz law. The changes in the shear moduli of the alginate beads resulted in changes in their physical properties. Alginate is a thermally sensitive material. Ultrasonic stimulation increased the temperature of the solution. When sonicated at high temperatures, the alginate beads shrank and their shear moduli increased exponentially. In the absence of the ultrasonic thermal effect, no change in the physical properties of the alginate beads was evident. Therefore, the ultrasonic thermal effect influenced the physical properties of the alginate beads. The stream and cavitation effects produced by the ultrasonic stimulation did not affect the properties of the alginate beads. it can be attributed to the fact that alginate beads have a high shear moduli and that the ultrasonic cavitation cannot damage the surface of alginate beads.

Effluence of Internal Substances from Pluronic Micelle Using Ultrasound

The application of micelles as a drug carrier for chemical reaction processes was investigated from the viewpoint of process intensification. The effects of ultrasonic stimulation and thermal stimulation on the effluence of internal hydrophobic dye from Pluronic micelles were investigated by measuring the absorbance of sample solutions. Internal substances could be released from the micelle rapidly by ultrasonic irradiation, and the ultrasonic physical effect is important for the effluence of internal substances. The possibility of new chemical reaction process using Pluronic micelles as a reactant carrier is revealed.

130 3次元培養軟骨細胞に対する超音波刺激とヒアルロン酸の影響(OS1-10 : 細胞の物理刺激応答(3),マイクロ・ナノバイオメカニクス)

130 3次元培養軟骨細胞に対する超音波刺激とヒアルロン酸の影響(OS1-10 : 細胞の物理刺激応答(3),マイクロ・ナノバイオメカニクス)