Wave Irradiation Research Articles

Covalently bonded polyaniline/graphene composites as high-performance electromagnetic (EM) wave absorption materials

In this work, the polyaniline nanorods/graphene sheets composites with covalent bond were synthesized through in-situ polymerization of aniline in the presence of amino-functionalized graphene sheets (AFG), in which polyaniline (PANI) polymerization is initiated by those amino groups on graphene. The chemical bonding between graphene and PANI is confirmed by several analytical techniques, including Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM) and thermogravimetric analysis (TGA). The microwave-absorbing properties of the composites were measured by a vector network analyzer. The electromagnetic data demonstrates that the maximum reflection loss of covalently bonded PANI-AFG can reach −51.5dB at 11.2GHz, and the absorption bandwidths exceeding −10dB are 4GHz with thickness of 2.5mm. The results indicate that the hybrid composites with enhanced microwave absorption properties and lightweight have a promising future in decreasing electromagnetic wave irradiation.

Thermal characteristics of non-biological vessel phantoms for treatment of varicose veins using high-intensity focused ultrasound.

The ultrasonic treatment of varicose veins uses high-intensity focused ultrasound, in which a blood vessel is contracted by converting acoustic energy into thermal energy. In this study, we propose a phantom of varicose veins that can be applied for the efficient evaluation of ultrasonic treatment in varicose veins. The proposed phantom consisted of glycerol base tissue equivalent material, vessel mimic tube, and blood mimic substances. The vessel mimic tube was placed inner glycerol phantom and it was filled with blood mimic substances. Blood-mimicked substances are prepared by adjusting the concentration of the glycerol solution to be similar to the acoustic properties of the blood, and vessel-mimicking materials are selected by measuring acoustic properties and thermal shrinkage of various materials in a heat-shrinkable tube. The blood vessels surrounding the tissue are replaced with the phantom similar to glycerol-based organization, and venous blood flow is implemented using a DC motor. The heating characteristics according to the ultrasonic wave using the manufactured varicose veins phantom were evaluated. As the sound wave irradiation time and power increased, the contractility of the vessel mimicking materials and the temperature of the surrounding tissues were increased. When the blood-mimicking material was circulated, the highest temperature in the focused region and the contractility of vessel mimicking materials were reduced under the same conditions as used for sonication. The manufactured phantom may contribute to the treatment of varicose veins and can be used to predict the ultrasonic therapeutic efficiency of varicose veins.

Production of photonic nanojets by using pupil-masked 3D dielectric cuboid

Photonic nanojets can be created via plane wave irradiation of multi-shaped mesoscale dielectric particles, and a waist of full-width at half-maximum (FWHM) smaller than the diffraction limit can be achieved in this process. In this paper, photonic nanojet produced by a pupil-masked 3D dielectric cuboid lens is numerically investigated under the irradiation of 532 nm wavelength plane wave. It is found that a pupil-masked cuboid lens is not only able to produce photonic nanojets with shorter FWHMs, but also increase its maximal intensity at certain masking ratios on the receiving surface. This phenomenon is different from the result of the spherical-lens reported in previous publications, and is attributed to the convergence of power flow and near-field numerical aperture (NA) increase after analysis of simulated power flow diagrams.

Gas–liquid flow mass transfer in a T-shape microreactor stimulated with 1.7 MHz ultrasound waves

Abstract This paper describes the application of ultrasound waves on hydrodynamics and mass transfer characteristics in the gas–liquid flow in a T-shape microreactor with a diameter of 800 μm. A 1.7 MHz piezoelectric transducer (PZT) was employed to induce the vibration in this microreactor. Liquid side volumetric mass transfer coefficients were measured by physical and chemical methods of CO2 absorption into water and NaOH solution. The approach of absorption of CO2 into a 1 mol·L− 1 NaOH solution was used for analysis of interfacial areas. With the help of a photography system, the fluid flow patterns inside the microreactor were analyzed. The effects of superficial liquid velocity, initial concentration of NaOH, superficial CO2 gas velocity and length of microreactor on the mass transfer rate were investigated. The comparison between sonicated and plain microreactors (microreactor with and without ultrasound) shows that the ultrasound wave irradiation has a significant effect on kLa and interfacial area at various operational conditions. For the microreactor length of 12 cm, ultrasound waves improved kLa and interfacial area about 21% and 22%, respectively. From this study, it can be concluded that ultrasound wave irradiation in microreactor has a great effect on the mass transfer rate. This study suggests a new enhancement technique to establish high interfacial area and kLa in microreactors.

Effects of photodynamic therapy with talaporfin sodium on squamous cell carcinoma and sarcoma cells

BackgroundPhotodynamic therapy (PDT) uses a photosensitizer and light to destroy abnormal cells. Talaporfin sodium (NPe6) is a second-generation photosensitizer. MethodsWe evaluated the toxic effects of different combinations of laser and NPe6 doses on squamous cell carcinoma (KLN205) and sarcoma (Meth A) cell lines. The cells were incubated with 0, 5, 10, or 30μg/mL NPe6 for 24h. The cells were then irradiated with 0, 5, 15, or 30mW/cm2 of laser power, and 0, 1, 5, 10, or 20J/cm2 of laser energy. Cell viability was evaluated after 24h. We also evaluated the cytotoxic effects of continuous wave or square-wave modulated laser irradiations (2, 5, or 10Hz, 50% duty) on Meth A cells. ResultsThe median lethal doses of NPe6 against the KLN205 and Meth A cells after treatment at a fluence rate of 15mW/cm2 and a light dose of 20J/cm2 were 18.6 and 5.0μg/mL, respectively. Meth A cells were more sensitive to PDT than KLN205 cells. There was no significant difference between the effects of continuous wave and square-wave modulated lasers on Meth A cell viability. ConclusionsNPe6 PDT induced cell death in a dose-dependent manner in KLN205 and Meth A cells. More work is required to evaluate the cytotoxic effects of square-wave modulated laser therapy at low light doses.

Microwave assisted aqueous phase synthesis of benzothiazoles and benzimidazoles in the presence of Ag2O

A simple and high yielding method for synthesized benzothiazoles and benzimidazole in water under micro wave irradiation by the reaction of 2-amino thiophenol and o-phenylenediamine with various aromatic aldehydes in the presence of Ag2O. Ag2O can be recovered and reused without significant loss of activity.

Intensification of liquid-liquid mass transfer in micromixer assisted by ultrasound irradiation and Fe3O4 nanoparticles

In the present study, Cu (II) removal from aqueous solution was performed in a micromixer by using D2EHPA solvent. The impact of nanoparticles addition, ultrasound wave irradiation and combination of them for improving mixing and mass transfer was investigated. The experiments were carried out in three different ultrasound input electrical powers (3.5–7W). A constant concentration of nanoparticles (0.01w/v) was employed in a reactor consists of a circular pit at its junction, and the results were compared with the Y-type microchannel (without ultrasonic source). Depending on the mixing approach type and flow rate of the phases (1.875–6mL/min), several separate flow patterns were observed, mainly slug, droplet, dispersed and parallel flow. The mass transfer coefficient (KLa) and removal efficiency (E) enhanced up to 251% and 53%, respectively. One of the benefits of the proposed techniques is a significant reduction in pressure drop compared with simple microchannels with the same volume. The highest amount of performance ratio (1.56) was observed in the presence of Fe3O4 nanoparticles under 7W ultrasonic irradiation power.

Effect of particle size on optical and electrical properties in mixed CdS and NiS nanoparticles synthesis by ultrasonic wave irradiation method

The mixed phase CdS and NiS nanoparticles are prepared by adopting ultrasonic wave irradiation method under different doping concentration of Ni in CdS. The well defined nano spheres are obtained during this synthesis process. The predicted particle sizes from X-ray diffraction (XRD) analysis are found to lie in the range between 37 and 49nm. The effective doping of Ni lead to form the mixture of two phases such as CdS and NiS. The respective change due to the formation of mixture of CdS and NiS is reflected well in the band gap energy which is measured in Diffused Reflectance Spectra (DRS). It is predicted in the range of 2.41–2.23eV respectively. Consistency of particle size with XRD are confirmed from Transmission Electron Microscope (TEM) images and also identified the presence of Nickel Sulfide and Cadmium Sulfide in nanostate with average particle size as 54nm. The Energy Dispersive X-ray (EDAX) analysis confirmed the existence of Ni, Cd and S the doping levels. The optical absorption analysis of samples are performed in UV–vis range 400–600nm. The synthesized samples are further characterized Fourier Transform Infrared (FT-IR) spectroscopy, Thermogravimetric (TGA) analysis, I-V characteristic and conductivity measurements.

Effect of stress wave irradiation on structural change in a colloidal system

Annealing is a typical method for controlling crystallographic structure of solids, and by increasing the number of phonon modes by heating, structural changes are caused. Considering that stress waves also enhance lattice vibrations, stress-wave irradiation should have similar effect on structural changes. In this study, we investigate the effect of stress-wave irradiation on crystallization of an amorphous solid using a colloidal system. A colloidal system used in this study is a mixture of a solution dyed with a fluorescein sodium salt and silica particles. It shows phases similar to those of atomic systems, and ordered (crystalline) and disordered (amorphous) structures are obtained. Because particle-scale analysis can be performed by using the confocal laser scanning microscopy, it has been used as a model system of atomic materials. We evaluate structural change of a colloidal glass after stress-wave irradiation and find that crystallization is accelerated at a specific condition. In the presentatio...

Intracellular Ca2+ increase in endothelial cells induced by shock wave irradiation

Shock wave irradiations induce bioeffects including angiogenesis and bone healing. However, physical mechanisms underlying those bioeffects remain elusive. Extracorporeal shock wave treatment (ESWT) is one of well-known shock wave therapies. In ESWT, shock waves destroy kidney stones with cavitation and negative pressures. Energy flux density of shock waves in ESWT is around 0.1—1 mJ/mm2. In this study, shock waves with energy flux density of 0.001 mJ/mm2, around 1/100 of ESWT, were irradiated on endothelial cells. In those cells, intracellular Ca2+ increase, i.e. a typical physiological response, was observed. Along the intracellular Ca2+ increase, extracellular fluid flow was not present. As well, both plasma membrane permeabilization and cell detachment were not detected. On the other hand, actin cytoskeletons, which link extracellular substrates and cellular components, were suggested to involve in the intracellular Ca2+ increase. Thus, it was supposed that shock waves initiated intracellular Ca2+ increase by loading forces on actin cytoskeletons. Although some previous studies have suggested that extracellular fluid flow could involve in shock wave induced bioeffects, intracellular Ca2+ increase seems to rely on extracellular fluid flow.

Effect of ultrasonic waves on dissociation kinetics of tetrafluoroethane (CH2FCF3) hydrate

The effect of ultrasonic waves on formation and dissociation kinetics of gas hydrates has been experimentally studied by several researchers. Some results indicated that ultrasonic waves have the effect of reducing gas hydrate induction time before the initiation of hydrate formation, while others reported on the effect of prohibiting the growth kinetics during hydrate formation. There have also been reports regarding an increase in the amount of gas consumed and a decrease in the hydrate formation time. The present study examines the influence of ultrasonic waves on gas hydrate dissociation. Gas hydrate formation and dissociation occurred in a temperature-controlled 15L horizontal cylindrical reactor. The reactor was agitated with a pair of flat blades installed in radial direction and a pair of rollers, which were driven by a motor connected through a magnetic coupler. R-134a, a gas that can form hydrates at a relatively low pressure, was used to form gas hydrate slurry. Dissociation was augmented by 20kHz ultrasonic waves generated with a piezoelectric converter and transmitted through a vibrating horn whose tip was in contact with the hydrated slurry in the reactor. To compare the effect of energy input in the form of ultrasonic waves with that of the same amount of heat input, equivalent amount of heat was provided to the reactor. Dissociation rate and the accumulated dissociation time were compared between the cases of heat addition and ultrasonic wave irradiation. Results show that not only does the dissociation rate increase with an increase in the ultrasonic wave power, but the irradiation of ultrasonic waves also enhances the dissociation of R-134a hydrate more effectively than the application of an equivalent amount of energy in the form of heat at the same location.

Polymer Morphological Change Induced by Terahertz Irradiation.

As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced “softly,” without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10−20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm2, which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules.

WITHDRAWN: Stimulation of Ultrasonic wave irradiation on CdS Nanoparticles as Nanorods

WITHDRAWN: Stimulation of Ultrasonic wave irradiation on CdS Nanoparticles as Nanorods

Impact of age-related cataract on regulation of circadian rhythm in elderly

This review presented an introduction of the visual pathway related circadian rhythm regulation system: the intrinsically photosensitive retinal ganglion cells-suprachiasmatic nucleus-pineal gland-melatonin axis, and discussed the impact of light with different wave length and irradiation received by retina on circadian rhythm and sleep habit. A hypothesis was proposed consequently that the high morbidity of sleep disorder in elderly might be partially attributable to the long-term blue light blocking status induced by age-related cataract. A number of relative literatures were reviewed and a novel research direction was advanced on improving circadian rhythm and sleep condition in elderly based on the current knowledge. (Chin J Ophthalmol, 2016, 52: 309-314).

Construction of CuS Nanoflakes Vertically Aligned on Magnetically Decorated Graphene and Their Enhanced Microwave Absorption Properties.

Hybrid nanocomposites with enhanced microwave absorption properties have been designed by growing CuS nanoflakes on magnetically decorated graphene, and the effect of special nanostructures on microwave absorption properties has been investigated. The structure of the nanocomposites was characterized by Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), N2 adsorption-desorption, and vibrating sample magnetometer (VSM). The influence of cetyltrimethylammonium bromide (CTAB) on the morphology of CuS nanoflakes was also investigated. A possible formation process of the nanocomposites and the mechanism of microwave absorption were explained in detail. As an absorber, the nanocomposites with a filler loading of 20 wt % exhibited enhanced microwave absorption properties due to the special nanostructures, extra void space, and synergistic effect. The maximum reflection loss can reach -54.5 dB at 11.4 GHz, and the absorption bandwidths exceeding -10 dB are 4.5 GHz with a thickness of 2.5 mm, which can be adjusted by the thickness. The results indicate that the hybrid nanocomposites with enhanced microwave absorption properties and lightweight have a promising future in decreasing electromagnetic wave irradiation.

Connexin32‑mediated antitumor effects of suicide gene therapy against hepatocellular carcinoma: In vitro and in vivo anticancer activity.

Normal hepatocytes express connexin32 (Cx32), which forms gap junctions at cell‑cell contact areas. The aim of the present study was to investigate whether Cx32 mediates the cell death‑inducing effects of ultrasound microbubbles carrying the herpes simplex virus thymidine kinase (HSV‑TK) suicide gene against hepatocellular carcinoma cells in vitro and in vivo. HepG2 cells were exposed to different concentrations of trans‑retinoic acid (ATRA) in culture, to evaluate the intrinsic antitumor effect of ATRA. Detailed in‑vitro and in‑vivo investigations on the antitumor effects of ATRA via Cx32 mediation were performed, and the possible underlying mechanisms of action of the compound were then examined. The gene expression of HSV‑TK transfected by ultrasound wave irradiation in the HepG2 cells was quantified using reverse transcription‑quantitative polymerase chain reaction analysis. The effects on cell death were assessed using an MTT assay. The protein expression levels of Cx32 in ATRA‑untreated or ATRA‑treated tissues were quantified by immunohistochemical analysis and Western blot assays. The HSV‑TK gene was successfully transfected into the HepG2 cell using ultrasound wave irradiation, and was stably expressed. Compared with the other groups, the HSV‑TK gene group treated with ATRA exhibited an increased number of apoptotic cells (P<0.05) and improved tumor suppression (P<0.05). ATRA significantly increased the expression of Cx32 in the hepatoma tissues (P<0.01). The present study demonstrated that ATRA elevated the protein expression of Cx32 and enhanced the bystander effect of the HSV‑TK/GCV suicide gene therapy system, which may provide a potential strategy for hepatocellular carcinoma treatment.

衝撃波照射によるアクチンフィラメントの構造変化

衝撃波照射によるアクチンフィラメントの構造変化

衝撃波を照射したコラーゲンゲルにおける異方性解析

衝撃波を照射したコラーゲンゲルにおける異方性解析

E-21 集束膨張波照射による軟組織への影響

E-21 集束膨張波照射による軟組織への影響

2D43 衝撃波照射が惹起する細胞内Ca^&lt;2+&gt;濃度上昇に対する細胞骨格の関与

2D43 衝撃波照射が惹起する細胞内Ca^&lt;2+&gt;濃度上昇に対する細胞骨格の関与