bluuebunny/crossref_metadata_2025 huggingface dataset:
Loss Reduction of Longitudinal-Type Leaky Surface Acoustic Wave by Reverse Proton Exchange
Authors: Kakio Shoji , Abe Masaya
Published: July 2012

The longitudinal-type leaky surface acoustic wave (LLSAW) is one of the SAW modes that is advantageous for application to high-frequency SAW devices. However, the LLSAW has huge inherent attenuation. In this study, to reduce the attenuation of the LLSAW, we proposed a layered structure of air, a bulk LiNbO3 (LN) layer, and an elastically softened LN substrate. When the layered structure was applied to X–36°Y LN with a large coupling factor K
2 for the LLSAW, the calculated attenuation for the metallized surface decreased at a certain depth of the bulk layer. To realize such a layered structure, a reverse proton exchange (RPE) process was applied to X–36°Y LN, and the propagation and resonance properties of the LLSAW were evaluated. A “good region” existed on the RPE wafer, in which the value of K
2 for the Rayleigh wave was recovered to approximately 80% of that of the virgin wafer. In comparison with the virgin wafer, the propagation loss for the free surface of the good region on the RPE wafer was decreased threefold, the insertion loss was decreased drastically, and the resonance properties were improved markedly.
Measurement Characteristics of Flow-Type Shear-Horizontal Surface Acoustic Wave Sensor for Direct Methanol Fuel Cells
Authors: Kano Koji , Kogai Takashi , Yoshimura Naoyuki , Yatsuda Hiromi , Kondoh Jun , Shiokawa Showko
Published: July 2012

Direct methanol fuel cells (DMFCs) offer promising future power sources. Operating DMFCs at ideal conditions, fuel concentration management is required, and therefore, devices for methanol concentration measurement are considered important to DMFC systems. Shear-horizontal surface acoustic wave (SH-SAW)-based methanol concentration sensors can be used as DMFCs offering advantages such as miniature size, mass-production ability, and reliability. The objective of this study was to develop and evaluate an easy to install SH-SAW sensor in a wide variety of DMFC systems. In this paper, we describe the detailed structure and measurement characteristics of the developed sensor system. The evaluations were focused on the linearity and response to methanol concentration change. Through the evaluations, theoretically predicted response linearity to the methanol concentration change was confirmed on the developed sensor. It was found that the response speed of the sensor was so quick that even a transient phenomenon of methanol spreading into water could be detected. These measurement abilities will be useful for accurate fuel control of DMFC systems, and should be able to extend the application range of SH-SAW sensors.
Experimental Study of Highly Sensitive Sensor Using a Surface Acoustic Wave Resonator for Wireless Strain Detection
Authors: Hara Bao , Mitsui Misato , Sano Koji , Nagasawa Sumito , Kuwano Hiroki
Published: July 2012

We developed a highly sensitive strain sensor employing a surface acoustic wave (SAW) resonator for a wireless sensing system. The aim of this study is to monitor the distribution of the strain in the earth crust or giant infrastructures, such as bridges, skyscrapers and power plants, for disaster prevention. A SAW strain sensor was fabricated using LiNbO3 and a quartz substrate, and applied in a tensile test by attaching the steel specimen based on Japanese Industrial Standards (JIS Z2441-1). The results confirmed that the developed sensor could detect a strain of 10-6 order with linearity.
Evaluation of Acousto-Optic Effect on Size Distribution Measurement of Oscillating Cavitation Bubbles Using Optical Spectrometer
Authors: Kuroyama Takanobu , Ebihara Tadashi , Mizutani Koichi , Ohbuchi Takeshi
Published: July 2012

A size distribution measurement method of the oscillating cavitation bubbles using the diffraction pattern of the bubbles has been studied by the authors. This method can measure the diameter distribution of the small oscillating bubbles. However, it has a disadvantage in that the measurement result of the method is disturbed by the acousto-optic effect. In this study, the influence of the acousto-optic effect on the measurement was experimentally investigated. As a result, it was found that the diffraction pattern tended to be disturbed along the direction of the ultrasound propagation. It was also recognized that the disturbance could be reduced using the diffraction pattern along the unsusceptible direction. Consequently, it was indicated that the diameter distribution of the oscillating bubbles was correctly measured using the diffraction pattern along the unsusceptible axis by comparison with the reference value measured by the stroboscopic imaging method.
Sonochemical Effect Using Ultrasonic Atomizer at 2.4 MHz
Authors: Shinashi Kiyoaki , Houkin Toshinori , Harada Hisashi
Published: July 2012

Sonochemical reactions were demonstrated using a commercial ultrasonic atomizer at 2.4 MHz. The influences of experimental conditions, bottom shape and glass thickness of reactors, irradiation method, and liquid height on the sonochemical yield were discussed. The sonochemical effect was evaluated by potassium iodide dosimetry and degradation of methylene blue. Direct and indirect irradiations were examined. The former had the highest yield. In the latter case, sonochemical yield decreased in the solution because glass prevented the transmission of ultrasonic waves. Poly film, on the other hand, could transmit ultrasonic waves very well without damage.
Influence of Transducer Structure on Mechanical and Chemical Effects of 20 kHz Sonication
Authors: Tran Khuyen Viet Bao , Asakura Yoshiyuki , Koda Shinobu
Published: July 2012

In this work, we examined the influence of transducer structure on the mechanical and chemical effects of 20 kHz sonication, where the dissipated power measured by calorimetry was kept constant (5 W). The mechanical effects were evaluated from the degradation rate of poly(ethylene oxide) in aqueous solution, and the chemical effects were measured with potassium iodide solution. The mechanical effects for a bath-type apparatus with the transducers fixed at a node with a diameter of 50 mm are nearly equal to those for a horn-type apparatus. The former transducer showed the strongest chemical effects among the transducers investigated here.
Effect of Ultrasonic Frequency and Power Density for Degradation of Dichloroacetonitrile by Sonolytic Ozonation
Authors: Park Beomguk , Shin Donghoon , Cho Eunju , Khim Jeehyeong
Published: July 2012

The degradation of dichloroacetonitrile (DCAN) by means of the processes of sonolysis, ozonolysis and sonolytic ozonolysis was studied, and degradation rate constants were evaluated at various frequencies and power densities of ultrasound. The ultrasonic frequencies used were 35, 170, 283, 450, and 935 kHz. The power densities were in the range of 9.5 to 20 W/L. The degradation rate constants for the sonolytic ozonolysis were (3.1–4.4)×10-3 min-1 with the power density of 9.5 W/L and the ozone dose of 3.7 g/h. And the synergistic effect in sonolytic ozonolysis was significant at 35 and 283 kHz among the five frequencies. The sonolytic ozonolysis provided an extra oxidation mechanism by generating additional hydroxyl radicals, giving significant enhancement on the process. The calculated values of synergistic effect were 2.56 and 2.15 at 35 and 283 kHz, respectively.
Effects of Power Density and TiO2 Dose in the Sonocatalytic Degradation of Diethyl Phthalate Using High Frequency
Authors: Cho Eunju , Park Beomguk , Na Seungmin , Khim Jeehyeong
Published: July 2012

Few studies using high frequencies have been carried out on the sono-TiO2 process, and consistent results based on the specific experimental conditions have not been reported thus far. Therefore, in the present work the effects of power density and dose on the kinetic constant of diethyl phthalate at 500 and 35 kHz using TiO2 have been evaluated. The slopes of kinetic constants depending on the power density regardless of TiO2 were increased and they were shown to be linear. However, the enhancement percentage according to the frequencies at 500 kHz was lower than that at 35 kHz, though clear discussions on the enhancement in the presence of TiO2 have not yet been produced. Also, the optimal dose was 1 g/L, which was not changed according to the frequency.
Effluence of Internal Substances from Pluronic Micelle Using Ultrasound
Authors: Kobayashi Daisuke , Karasawa Masahiro , Takahashi Tomoki , Otake Katsuto , Shono Atsushi
Published: July 2012

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.
Arsenite Oxidation by Ultrasound Combined with Ultraviolet in Aqueous Solution
Authors: Lee Seban , Cui Mingcan , Na Seungmin , Khim Jeehyeong
Published: July 2012

This study aims to investigate the sonophotochemical oxidation of As(III) to As(V) using the synergistic effect of a strong oxidant that is a hydroxyl radical. The rate constant, k, in the ultrasound (US), ultraviolet C (UV-C), and US/UV-C processes was found to be 1.65×10-4, 3.65×10-4, and 8.31×10-4 s-1 respectively. The highest power densities were 21.26, in the case of UV-C, and 26.27 W L-1 for US. Finally, the combined US/UV-C system gave a synergistic effect value of 1.57. This was similar to the synergistic effect value of the production of hydroxyl radicals with potassium iodide (KI) solution using the same combined process. Moreover, the reaction rate of the As(III) oxidation to As(V) in the US/UV-C process increased with a gradual increase in pH. The reaction rates were found to be 1.88×10-3 at pH 11 and 8.31×10-4 s-1 at pH 7. Therefore, the reaction rate at pH 11 was 2.3 times faster than that at pH 7.
Relation between Acoustic Impedance and Sound Intensity Amplification in a Stack of Standing-Wave Thermoacoustic Prime Mover
Authors: Sahashi Kazuki , Sakamoto Shin-ichi , Kuroda Kentaro , Watanabe Yoshiaki
Published: July 2012

A standing-wave thermoacoustic prime mover and a traveling-wave one realize cooling systems of not having moving parts. The prime movers have a challenge of being miniaturized for a practical use. For the miniaturization, in contrast to lower energy conversion efficiency than the traveling-wave thermoacoustic prime mover, the standing-wave one has some advantages of its simple structure and no acoustic streaming. The efficiency depends on the amplification quantity of sound intensity in the stack. However, the intensity measurement in the stack is difficult. In this paper, for improving the efficiency of the standing-wave thermoacoustic prime mover, the amplification quantity of sound intensity in the stack is calculated and discussed especially with the acoustic impedance in the stack. Consequently, results show that the efficiency improves when the absolute value of the acoustic impedance is low in the stack.
Investigation of Thermal Conductivity and Heat Characteristics of Oil Sands Using Ultrasound Irradiation for Shortening the Preheating Time
Authors: Kamagata Shingo , Kawamura Youhei , Okawa Hirokazu , Mizutani Koichi
Published: July 2012

Oil sands are attractive as an energy resource. Bitumen, which is found in oil sands, has high viscosity, so that it does not flow. Most oil sands are underground and are developed with a method called steam-assisted gravity drainage (SAGD). Hot steam is injected underground to fluidize bitumen and promote its recovery. However, the preheating time is too long. One way of reducing running costs is by shortening the preheating time. Previous studies have found that bitumen can be extracted from oil sands efficiently by applying ultrasonic irradiation, but SAGD was not applied directly in these cases. Thus, the purpose of this study is to apply ultrasonic irradiation to SAGD, thereby shortening the preheating time of oil sands. As a model experiment for SAGD, heat transfer experiments in a sand layer made with Toyoura sand and silicone oil were conducted and the thermal effect with ultrasound was investigated.
Enhanced Removal of Hydrophobic Gas by Aerial Ultrasonic Waves and Two Kinds of Water Mists of Different Particle Sizes
Authors: Matsumoto Keisuke , Miura Hikaru
Published: July 2012

Air pollutants can cause health problems, such as bronchitis and cancer, and are now recognized as a social problem. Hence, a method is proposed for the collection and removal of gaseous air pollutants by aerial ultrasonic waves and water mist. Typically, gas removal effects are studied using lemon oil vapor (“lemon gas”), which is a hydrophobic gas. Previous experiments using lemon gas have shown that a removal rate of up to 40% can be achieved in an intense standing wave at 20 kHz, for an amount of water mist of 1.39 cm3/s and an electrical input power of 50 W. Increasing the surface area of the water mist leads to greater removal of hydrophobic gas. In this study, the effects of gas removal are examined by conducting experiments using intense aerial ultrasonic waves to disperse two kinds of water mists, each composed of particles of different sizes: small particles (diameter: ≈3 µm) and conventional large particles (diameter: ≈60 µm).
Characteristics of Hole Machining of Brittle Material by Ultrasonic Complex Vibration
Authors: Asami Takuya , Miura Hikaru
Published: July 2012

A new method using a polishing slurry together with ultrasonic longitudinal and torsional vibrations from a source with a diagonal slit vibration converter is developed for the hole machining of brittle materials. We predict that removal rate and machining accuracy will be improved using ultrasonic longitudinal–torsional vibration when compared with using conventional longitudinal vibration machining. In experiments, soda-lime glass is used as the processing material, and hole roundness error and machining time are measured to assess the hole machining characteristics. We find that machining accuracy is improved using ultrasonic longitudinal–torsional vibration.
Properties of Miniature Cantilever-Type Ultrasonic Motor Using Lead-Free Array-Type Multilayer Piezoelectric Ceramics of (Sr,Ca)2NaNb5O15 under High Input Power
Authors: Doshida Yutaka , Shimizu Hiroyuki , Mizuno Youich , Tamura Hideki
Published: July 2012

The properties of miniature cantilever-type ultrasonic motors using lead-free array-type multilayer piezoelectric ceramics of (Sr,Ca)2NaNb5O15 (SCNN) developed using the design rule were investigated under high input power by comparison with the high-power properties of SCNN ceramics. The frequency dependence of the revolution speed reflected the nonlinear behavior of SCNN ceramics with the hard-spring effect and showed a mirror-reversed image relative to that of the motor of Pb(Zr,Ti)O3 (PZT) ceramics. The output power increased linearly with increasing input power up to 110 mW without heat generation, and the driving properties were almost the same as the expectations under low input power. The output power density characteristics of the motors were high in comparison with those of the commercialized motors of PZT ceramics. It appeared that the motors have a high potential as an environmental friendly piezoelectric device with excellent properties, reflecting the high-power properties of SCNN ceramics.
Development of Multiple-Frequency Ultrasonic Imaging System Using Multiple Resonance Piezoelectric Transducer
Authors: Akiyama Iwaki , Yoshizumi Natsuki , Saito Shigemi , Wada Yuji , Koyama Daisuke , Nakamura Kentaro
Published: July 2012

The authors have developed a multiple frequency imaging system using a multiple resonance transducer (MRT) consisting of 1–3 composite materials with a low mechanical quality factor Q bonded together. The MRT has a structure consisting of thin and thick piezoelectric plates, two matching layers, and a backing layer. This makes it possible to obtain B-mode images of satisfactory resolution using ultrasonic pulses owing to their short duration. In this paper, the vibration property of the MRT derived through equivalent-circuit analysis is first shown. By utilizing the result, an MRT capable of transmitting ultrasonic pulses for generation of the images of biological tissues with satisfactory resolution is designed and prototyped. Setting the prototype transducer in the mechanical sector probe of commercial ultrasonic diagnosis equipment, the speckle reduction effect is demonstrated using images of various phantoms to mimic biological tissues and a human thyroid.
Simultaneous Multispectral Coded Excitation Using Gold Codes for Photoacoustic Imaging
Authors: Zhang Haichong , Kondo Kengo , Yamakawa Makoto , Shiina Tsuyoshi
Published: July 2012

Photoacoustics (PA) enables obtaining functional information like optics and depth information similarly to ultrasonics. The prospect of PA has already been discussed in previous studies, but there is a current demand for PA imaging that works as real-time imaging to acquire multispectral information in simultaneous irradiation with a high signal-to-noise ratio. We propose coded excitation using Gold codes that have good autocorrelation and cross-correlation properties to satisfy this demand. In this study, we also demonstrate the feasibility through simulations of RF signals and linear scanning B-mode imaging, and conduct an experiment to determine the feasibility of Gold codes for PA imaging. Our results show similarity to the theoretically predicted value, supporting the effective use of Gold codes.
Detection of Boundaries of Carotid Arterial Wall by Analyzing Ultrasonic RF Signals
Authors: Ibrahim Nabilah , Hasegawa Hideyuki , Kanai Hiroshi
Published: July 2012

In line with the fact that the intima–media thickness (IMT) of the carotid arterial wall is the most frequently used indicator to diagnose atherosclerosis by ultrasound, it is essential to accurately estimate the thickness of the intima–media complex (IMC) boundaries, i.e., the lumen–intima boundary (LIB) and media–adventitia boundary (MAB). In this study, an improved adaptive model of an ultrasonic echo was developed for the model to realize better fitting to the reference RF echo, which is measured from a glass plate, using a Gaussian window for the envelope function of the adaptive model. Using the mean squared error (MSE) method, the envelope of the improved adaptive model (multiply the sinusoidal wave with the Gaussian window) was fitted with the envelope of an RF echo measured in vivo to estimate the boundaries of the carotid arterial wall. Firstly, a computer simulation of the carotid arterial wall was conducted to evaluate the accuracy of boundary detection using the envelope of the improved adaptive model. In the simulation, IMT was set at 0.50 mm in a 7.2-mm-long short segment in the longitudinal direction. The IMT estimated by the proposed method was 0.54 mm. The 8% error between the true and detected IMTs showed the high accuracy of the envelope of the improved adaptive model in boundary detection. In the in vivo measurement, for the 4.8-mm-long short segment in the longitudinal direction, the average IMT automatically estimated by the proposed method was 0.57 mm. The result was compared with those obtained by the previous method and manually. The IMT estimated by the previous method, which uses an RF adaptive model, was 0.59 mm and the manually determined IMT was 0.56 mm. The smaller difference between the results obtained by the proposed method and manually verified that boundary detection by the proposed method was better than that by the previous method.
Tissue Viscoelasticity Imaging Using Vibration and Ultrasound Coupler Gel
Authors: Yamakawa Makoto , Shiina Tsuyoshi
Published: July 2012

In tissue diagnosis, both elasticity and viscosity are important indexes. Therefore, we propose a method for evaluating tissue viscoelasticity by applying vibration that is usually performed in elastography and using an ultrasound coupler gel with known viscoelasticity. In this method, we use three viscoelasticity parameters based on the coupler strain and tissue strain: the strain ratio as an elasticity parameter, and the phase difference and the normalized hysteresis loop area as viscosity parameters. In the agar phantom experiment, using these viscoelasticity parameters, we were able to estimate the viscoelasticity distribution of the phantom. In particular, the strain ratio and the phase difference were robust to strain estimation error.
Elasticity Evaluation of Regenerating Cartilage Sample Based on Laser Doppler Measurement of Ultrasonic Particle Velocity
Authors: Nitta Naotaka , Misawa Masaki , Homma Kazuhiro , Shiina Tsuyoshi
Published: July 2012

It is important for regenerative medicine to evaluate the maturity of regenerating tissue. In the maturity evaluation of regenerating cartilage, it is useful to measure the temporal change of elasticity because the maturity of regenerating tissue is closely related to its elasticity. In this study, an elasticity evaluation method for the extracted regenerating cartilage sample, which is based on the laser Doppler measurement of ultrasonic particle velocity, was experimentally investigated using agar-based phantoms with different elastic moduli and the regenerating cartilage samples extracted from beagles in animal experiments. In addition, the experimentally-obtained elasticity was compared with the result of a static compression test. These results verified the feasibility of the proposed method in the elasticity evaluation of regenerating cartilage samples.
Optimal Design of Damper Layer for Static Elastography
Authors: Sato Takayuki , Watanabe Yasuaki , Sekimoto Hitoshi
Published: July 2012

An effective method in static elastography for improving the nonuniformity of stress applied by the shape of a transducer head is to insert a damper between the tissue being analyzed and the transducer head. We previously demonstrated the effectiveness of inserting a damper through computer simulations of structural and acoustic analyses on tissue models with flat surfaces. In this study, the optimal values were obtained for two parameters of the damper: Young's modulus and damper thickness. An effective damper shape was also determined through structural analyses.
Tissue-Mimicking Materials Using Segmented Polyurethane Gel and Their Acoustic Properties
Authors: Yoshida Tomoji , Tanaka Kouhei , Kondo Toshio , Yasukawa Kazuhiro , Miyamoto Nobuaki , Taniguchi Masahiko , Shikinami Yasuo
Published: July 2012

Accurate testing of an instrument by phantoms requires a tissue-mimicking material that has the acoustic velocity and density defined in the International Electrotechnical Commission (IEC) standard, and furthermore the tissue-mimicking material must be stable over time. To achieve the tissue-mimicking materials with the desired acoustic velocity and density defined in the IEC standard, new materials have been developed. The form of tissue-mimicking materials reported comprised polystyrene and poly(methyl methacrylate) (PMMA) particles dispersed in segmented polyurethane gel. They were stable over a period of 40 days and the changes in weight and acoustic velocity did not exceed 0.5%.
Measurement of Wave Velocity in Cortical Bone by Micro-Brillouin Scattering Technique: Effect of Bone Tissue Properties
Authors: Fukui Kenji , Takayanagi Shinji , Suga Daisuke , Matsukawa Mami
Published: July 2012

Hypersonic wave velocity was measured in the cortical bone of bovine femur using a micro-Brillouin scattering technique. Using thin plate specimens, wave velocities propagating in the bone axis direction were measured. Next, focusing on the hydroxyapatite (HAp), which is one of the main components of bone, we estimated the relationship between wave velocity and HAp content. The decalcification caused a clear wave velocity decrease from 5.06×103 to 3.28×103 m/s, showing the strong effects of HAp on the elasticity of bone. The micro-Brillouin scattering technique would be helpful for the evaluation of bone characterization in a small area.
Development of Bone-Conducted Ultrasonic Hearing Aid for the Profoundly Deaf: Assessments of the Modulation Type with Regard to Intelligibility and Sound Quality
Authors: Nakagawa Seiji , Fujiyuki Chika , Kagomiya Takayuki
Published: July 2012

Bone-conducted ultrasound (BCU) is perceived even by the profoundly sensorineural deaf. A novel hearing aid using the perception of amplitude-modulated BCU (BCU hearing aid: BCUHA) has been developed; however, further improvements are needed, especially in terms of articulation and sound quality. In this study, the intelligibility and sound quality of BCU speech with several types of amplitude modulation [double-sideband with transmitted carrier (DSB-TC), double-sideband with suppressed carrier (DSB-SC), and transposed modulation] were evaluated. The results showed that DSB-TC and transposed speech were more intelligible than DSB-SC speech, and transposed speech was closer than the other types of BCU speech to air-conducted speech in terms of sound quality. These results provide useful information for further development of the BCUHA.
Design and Numerical Evaluation of Off-Axis Aplanatic Straubel Mirror for Underwater Acoustic Imaging
Authors: Sato Yuji , Mizutani Koichi , Wakatsuki Naoto , Nakamura Toshiaki
Published: July 2012

An aplanatic Straubel mirror was designed for underwater acoustic imaging. However, there was a problem in that incident sound waves coming into the aplanatic Straubel mirror were interrupted by a receiver array placed in front of the mirror. An off-axis Straubel mirror is proposed to solve this problem. In this study, an off-axis aplanatic Straubel mirror is designed and evaluated using numerical calculation to verify the feasibility of the off-axis design. Upon comparison of the off-axis and ordinary aplanatic Straubel mirrors, the off-axis mirror shows almost the same convergence property as the ordinary one when a receiver array exists. The off-axis aplanatic Straubel mirror is compared with an aplanatic Fresnel lens because this lens is not affected by the receiver. The results show that the off-axis mirror showed a smaller aberration than the aplanatic Fresnel lens at a wider angle of view.
Revolution of Sensors in Micro-Electromechanical Systems
Authors: Esashi Masayoshi
Published: July 2012

Microsensors realized by micro-electromechanical systems (MEMS) technology play a key role as the input devices of systems. In this report, the following sensors are reviewed: piezoresistive and capacitive pressure sensors, surface acoustic wave (SAW) wireless pressure sensors, tactile sensor networks for robots, accelerometers, angular velocity sensors (gyroscopes), range image sensors using optical scanners, infrared imagers, chemical sensing systems as Fourier transform infrared (FTIR) spectroscopy and gas chromatography, flow sensors for fluids, and medical sensors such as ultrafine optical-fiber blood pressure sensors and implantable pressure sensors.
Stacked Polypyrrole-Coated Nonwoven Fabric Sheets for Absorbing Electromagnetic Waves with Broadband Frequencies
Authors: Egami Yoshihiro , Yamamoto Takashi , Suzuki Kunio , Higuchi Eiji , Inoue Hiroshi
Published: July 2012

Microwave absorbability of electromagnetic waves in the frequency range of 1–15 GHz, which is often used in recent wireless applications, for stacks of various numbers of conductive nonwoven fabric sheets with different resistivity was evaluated to clarify their possibility as the broadband microwave absorber in the frequency range of 1–15 GHz. The conductive nonwoven fabric sheets coated with polypyrrole nanoparticles, which had resistivities from 4.6 ×103 to 1.2×102 Ω cm, were prepared by immersing nonwoven fabric sheets in solutions containing various concentrations of an oxidizing agent and a dopant and then exposing the sheets to pyrrole vapor. The real part (ε') and the imaginary part (ε'') of complex permittivity for each conductive nonwoven fabric sheet increased with decreasing frequency, indicating the dispersion of permittivity. In addition, the reflection loss decreased when ammonium persulfate concentration increased and/or the stack size increased. However, the stack of two conductive nonwoven fabric sheets (thickness: 6.6 mm) with a resistivity of less than 120 Ω cm had average reflection losses of less than -10 dB in the frequency range of 1–15 GHz. From this way, it can be considered that the stacked conductive nonwoven fabric sheets prepared in this study can be a new material that effectively absorbs electromagnetic waves in the wide frequency range.
Activation of NTS A1adenosine receptors inhibits regional sympathetic responses evoked by activation of cardiopulmonary chemoreflex
Authors: Ichinose Tomoko K. , Minic Zeljka , Li Cailian , O'Leary Donal S. , Scislo Tadeusz J.
Published: July 2012

Previously we have shown that adenosine operating via the A1receptor subtype may inhibit glutamatergic transmission in the baroreflex arc within the nucleus of the solitary tract (NTS) and differentially increase renal (RSNA), preganglionic adrenal (pre-ASNA), and lumbar (LSNA) sympathetic nerve activity (ASNA>RSNA≥LSNA). Since the cardiopulmonary chemoreflex and the arterial baroreflex are mediated via similar medullary pathways, and glutamate is a primary transmitter in both pathways, it is likely that adenosine operating via A1receptors in the NTS may differentially inhibit regional sympathetic responses evoked by activation of cardiopulmonary chemoreceptors. Therefore, in urethane-chloralose-anesthetized rats ( n = 37) we compared regional sympathoinhibition evoked by the cardiopulmonary chemoreflex (activated with right atrial injections of serotonin 5HT3receptor agonist phenylbiguanide, PBG, 1–8 μg/kg) before and after selective stimulation of NTS A1adenosine receptors [microinjections of N6-cyclopentyl adenosine (CPA), 0.033–330 pmol/50 nl]. Activation of cardiopulmonary chemoreceptors evoked differential, dose-dependent sympathoinhibition (RSNA>ASNA>LSNA), and decreases in arterial pressure and heart rate. These differential sympathetic responses were uniformly attenuated in dose-dependent manner by microinjections of CPA into the NTS. Volume control ( n = 11) and blockade of adenosine receptor subtypes in the NTS via 8-( p-sulfophenyl)theophylline (8-SPT, 1 nmol in 100 nl) ( n = 9) did not affect the reflex responses. We conclude that activation of NTS A1adenosine receptors uniformly inhibits neural and cardiovascular cardiopulmonary chemoreflex responses. A1adenosine receptors have no tonic modulatory effect on this reflex under normal conditions. However, when adenosine is released into the NTS (i.e., during stress or severe hypotension/ischemia), it may serve as negative feedback regulator for depressor and sympathoinhibitory reflexes integrated in the NTS.
Loss of quadriceps muscle oxidative phenotype and decreased endurance in patients with mild-to-moderate COPD
Authors: van den Borst Bram , Slot Ilse G. M. , Hellwig Valéry A. C. V. , Vosse Bettine A. H. , Kelders Marco C. J. M. , Barreiro Esther , Schols Annemie M. W. J. , Gosker Harry R.
Published: July 2012

Being well-established in advanced chronic obstructive pulmonary disease (COPD), skeletal muscle dysfunction and its underlying pathology have been scarcely investigated in patients with mild-to-moderate airflow obstruction. We hypothesized that a loss of oxidative phenotype (oxphen) associated with decreased endurance is present in the skeletal muscle of patients with mild-to-moderate COPD. In quadriceps muscle biopsies from 29 patients with COPD (forced expiratory volume in 1 s [FEV1] 58 ± 16%pred, body mass index [BMI] 26 ± 4 kg/m2) and 15 controls (BMI 25 ± 3 kg/m2) we assessed fiber type distribution, fiber cross-sectional areas (CSA), oxidative and glycolytic gene expression, OXPHOS protein levels, metabolic enzyme activity, and levels of oxidative stress markers. Quadriceps function was assessed by isokinetic dynamometry, body composition by dual-energy X-ray absorptiometry, exercise capacity by an incremental load test, and physical activity level by accelerometry. Compared with controls, patients had comparable fat-free mass index, quadriceps strength, and fiber CSA, but quadriceps endurance was decreased by 29% ( P = 0.002). Patients with COPD had a clear loss of muscle oxphen: a fiber type I-to-II shift, decreased levels of OXPHOS complexes IV and V subunits (47% and 31%, respectively; P < 0.05), a decreased ratio of 3-hydroxyacyl-CoA dehydrogenase/phosphofructokinase (PFK) enzyme activities (38%, P < 0.05), and decreased peroxisome proliferator-activated receptor-γ coactivator-1α (40%; P < 0.001) vs. increased PFK (67%; P < 0.001) gene expression levels. Within the patient group, markers of oxphen were significantly positively correlated with quadriceps endurance and inversely with the increase in plasma lactate relative to work rate during the incremental test. Levels of protein carbonylation, tyrosine nitration, and malondialdehyde protein adducts were comparable between patients and controls. However, among patients, oxidative stress levels were significantly inversely correlated with markers of oxphen and quadriceps endurance. Reduced muscle endurance associated with underlying loss of muscle oxphen is already present in patients with mild-to-moderate COPD without muscle wasting.
Responsiveness to nicotine of neurons of the caudal nucleus of the solitary tract correlates with the neuronal projection target
Authors: Feng Lin , Sametsky Evgeny A. , Gusev Alexander G. , Uteshev Victor V.
Published: July 2012

The caudal nucleus of the solitary tract (NTS) is the key integrating center of visceral sensory-motor signaling supporting autonomic homeostasis. Two key projections of this nucleus are the parabrachial nucleus (PbN) and the dorsal motor nucleus of the vagus (DMV). The PbN integrates and relays viscerosensory information primarily to the forebrain, supporting behavioral, emotional, and endocrine responses to visceral events, while the DMV contains parasympathetic preganglionic cholinergic motoneurons that support primarily gastrointestinal reflexes. Subsets of caudal NTS neurons express presynaptic and somatodendritic nicotinic acetylcholine receptors (nAChRs). However, the anatomical identification of nicotine-responsive caudal NTS neurons has not been determined. This study used in vivo and ex vivo fluorescent tracing and slice patch-clamp electrophysiological recordings from anatomically identified caudal NTS neurons to test the hypothesis that the responsiveness of these cells to nicotine correlates with the target of their axonal projections. The results demonstrate that the majority of glutamatergic terminals that synapse on PbN-projecting caudal NTS neurons are unaffected by nicotine. Moreover, only a fraction of these cells express somatodendritic nAChRs. In contrast, the majority of DMV-projecting caudal NTS neurons exhibit robust presynaptic and somatodendritic responsiveness to nicotine. However, PbN-projecting neurons also exhibit significantly lower background frequencies of glutamatergic miniature postsynaptic currents than DMV-projecting neurons. Therefore, presynaptic unresponsiveness to nicotine may result from deficient glutamatergic innervation of PbN-projecting neurons. Nevertheless, the caudal NTS contains function-specific subsets of cells with target-specific responsiveness to nicotine. These results may support development of therapeutic strategies for selective targeting of specific autonomic pathways and impaired autonomic homeostasis.
Intrinsic heterogeneity in oscillatory dynamics limits correlation-induced neural synchronization
Authors: Burton Shawn D. , Ermentrout G. Bard , Urban Nathaniel N.
Published: July 2012

Synchronous neural oscillations are found throughout the brain and are thought to contribute to neural coding and the propagation of activity. Several proposed mechanisms of synchronization have gained support through combined theoretical and experimental investigation, including mechanisms based on coupling and correlated input. Here, we ask how correlation-induced synchrony is affected by physiological heterogeneity across neurons. To address this question, we examined cell-to-cell differences in phase-response curves (PRCs), which characterize the response of periodically firing neurons to weak perturbations. Using acute slice electrophysiology, we measured PRCs across a single class of principal neurons capable of sensory-evoked oscillations in vivo: the olfactory bulb mitral cells (MCs). Periodically firing MCs displayed a broad range of PRCs, each of which was well fit by a simple three-parameter model. MCs also displayed differences in firing rate-current relationships and in preferred firing rate ranges. Both the observed PRC heterogeneity and moderate firing rate differences (∼10 Hz) separately reduced the maximum correlation-induced synchrony between MCs by up to 25–30%. Simulations further demonstrated that these components of heterogeneity alone were sufficient to account for the difference in synchronization among heterogeneous vs. homogeneous populations in vitro. Within this simulation framework, independent modulation of specific PRC features additionally revealed which aspects of PRC heterogeneity most strongly impact correlation-induced synchronization. Finally, we demonstrated good agreement of novel mathematical theory with our experimental and simulation results, providing a theoretical basis for the influence of heterogeneity on correlation-induced neural synchronization.
Imaging neural circuit dynamics with a voltage-sensitive fluorescent protein
Authors: Akemann Walther , Mutoh Hiroki , Perron Amélie , Park Yun Kyung , Iwamoto Yuka , Knöpfel Thomas
Published: July 2012

Population signals from neuronal ensembles in cortex during behavior are commonly measured with EEG, local field potential (LFP), and voltage-sensitive dyes. A genetically encoded voltage indicator would be useful for detection of such signals in specific cell types. Here we describe how this goal can be achieved with Butterfly, a voltage-sensitive fluorescent protein (VSFP) with a subthreshold detection range and enhancements designed for voltage imaging from single neurons to brain in vivo. VSFP-Butterfly showed reliable membrane targeting, maximum response gain around standard neuronal resting membrane potential, fast kinetics for single-cell synaptic responses, and a high signal-to-noise ratio. Butterfly reports excitatory postsynaptic potentials (EPSPs) in cortical neurons, whisker-evoked responses in barrel cortex, 25-Hz gamma oscillations in hippocampal slices, and 2- to 12-Hz slow waves during brain state modulation in vivo. Our findings demonstrate that cell class-specific voltage imaging is practical with VSFP-Butterfly, and expand the genetic toolbox for the detection of neuronal population dynamics.
Flight Dynamics and Abundance ofIps sexdentatus(Coleoptera: Curculionidae: Scolytinae) in Different Sawmills from Northern Spain: Differences between LocalPinus radiata(Pinales: Pinaceae) and Southern France IncomingP. pinasterTimber
Authors: López Sergio , Goldarazena Arturo
Published: July 2012

In January 2009, the windstorm “Klaus” struck the southern part of France, affecting 37.9 million m3of maritime pinePinus pinasterAiton (Pinales: Pinaceae). This breeding plant material favored the outbreak ofIps sexdentatus(Börner) (Coleoptera: Curculionidae: Scolytinae). As much of this timber is imported to the Basque Country (northern Spain), a potential risk to conifer stands is generated, due to the emergence of the incoming beetles. Thus, flight dynamics and beetle abundance were compared in different sawmills, according to the timber species (either localP. radiataD. Don or importedP. pinaster). A maximum flight peak ofI. sexdentatuswas observed in mid-June inP. pinasterimporting sawmills, whereas a second lighter peak occurred in September. In contrast, only a maximum peak in mid-June was observed inP. radiatainhabiting beetles, being significantly smaller than in localP. pinastertrading sawmills. In addition, significant differences were found between importedP. pinasterandP. radiataregarding the number of insects beneath the bark. The development of IPM strategies for controllingI. sexdentatuspopulations is recommended, due to the insect abundance found inP. pinasterimported timber.
The Transjugular Intrahepatic Portosystemic Shunt in the Treatment of Portal Hypertension: Current Status
Authors: Pomier-Layrargues Gilles , Bouchard Louis , Lafortune Michel , Bissonnette Julien , Guérette Dave , Perreault Pierre
Published: July 2012

The transjugular intrahepatic portosystemic shunt (TIPS) represents a major advance in the treatment of complications of portal hypertension. Technical improvements and increased experience over the past 24 years led to improved clinical results and a better definition of the indications for TIPS. Randomized clinical trials indicate that the TIPS procedure is not a first-line therapy for variceal bleeding, but can be used when medical treatment fails, both in the acute situation or to prevent variceal rebleeding. The role of TIPS to treat refractory ascites is probably more justified to improve the quality of life rather than to improve survival, except for patients with preserved liver function. It can be helpful for hepatic hydrothorax and can reverse hepatorenal syndrome in selected cases. It is a good treatment for Budd Chiari syndrome uncontrollable by medical treatment. Careful selection of patients is mandatory before TIPS, and clinical followup is essential to detect and treat complications that may result from TIPS stenosis (which can be prevented by using covered stents) and chronic encephalopathy (which may in severe cases justify reduction or occlusion of the shunt). A multidisciplinary approach, including the resources for liver transplantation, is always required to treat these patients.
Two‐Step Self‐Assembly and Lyotropic Liquid Crystal Behavior of TiO2 Nanorods
Authors: Ren Zhimin , Chen Chao , Hu Rong , Mai Kaiguang , Qian Guodong , Wang Zhiyu
Published: July 2012

Several self‐assembly structures of anatase TiO2 nanorods were obtained by a two‐step assembly process, and these structures formed different lyotropic liquid crystal in solution. Primary self‐assembly occurred in synthesis process and formed two structures, in the morphology of ribbon and honeycomb, respectively. Secondary‐assembly took place when the products were placed at lower temperature, where unique structures were obtained as the relative amount of ribbon and honeycomb changed with the increase of TiO2 concentration. These structures showed nematic, spherulites, and lamellar phases. The mechanism of the two‐step self‐assembly was clarified. The driving force of primary assembly is deduced to be anisotropic attractive force, for NRs can assemble at any concentrations, while gravity is the driving force of the secondary assembly. It is worth mentioning that this paper is the first report about spherulites composing of anatase TiO2 nanorods. The spherulites obtained were negative or of tangential type, and its structure, growth process, and temperature influences were also investigated. The spherulites may have promising application in temperature microsensor.
Objective No-Reference Stereoscopic Image Quality Prediction Based on 2D Image Features and Relative Disparity
Authors: Sazzad Z. M. Parvez , Akhter Roushain , Baltes J. , Horita Y.
Published: July 2012

Stereoscopic images are widely used to enhance the viewing experience of three-dimensional (3D) imaging and communication system. In this paper, we propose an image feature and disparity dependent quality evaluation metric, which incorporates human visible system characteristics. We believe perceived distortions and disparity of any stereoscopic image are strongly dependent on local features, such as edge (i.e., nonplane areas of an image) and nonedge (i.e., plane areas of an image) areas within the image. Therefore, a no-reference perceptual quality assessment method is developed for JPEG coded stereoscopic images based on segmented local features of distortions and disparity. Local feature information such as edge and non-edge area based relative disparity estimation, as well as the blockiness and the edge distortion within the block of images are evaluated in this method. Subjective stereo image database is used for evaluation of the metric. The subjective experiment results indicate that our metric has sufficient prediction performance.
Identification of TNIP1 Polymorphisms by High Resolution Melting Analysis with Unlabelled Probe: Association with Systemic Lupus Erythematosus
Authors: Zhang Jie , Chen Yuewen , Shao Yong , Wu Qi , Guan Ming , Zhang Wei , Wan Jun , Yu Bo
Published: July 2012

Background. TNFα-induced protein 3 (TNFAIP3) interacting with protein 1 (TNIP1) acts as a negative regulator of NF-κB and plays an important role in maintaining the homeostasis of immune system. A recent genome-wide association study (GWAS) showed that the polymorphism of TNIP1 was associated with the disease risk of SLE in Caucasian. In this study, we investigated whether the association of TNIP1 with SLE was replicated in Chinese population.Methods. The association of TNIP1 SNP rs7708392 (G/C) was determined by high resolution melting (HRM) analysis with unlabeled probe in 285 SLE patients and 336 healthy controls.Results. A new SNP rs79937737 located on 5 bp upstream of rs7708392 was discovered during the HRM analysis. No association of rs7708392 or rs79937737 with the disease risk of SLE was found. Furthermore, rs7708392 and rs79937737 were in weak linkage disequilibrium (LD). Hypotypes analysis of the two SNPs also showed no association with SLE in Chinese population.Conclusions. High resolution melting analysis with unlabeled probes proves to be a powerful and efficient genotyping method for identifying and screening SNPs. No association of rs7708392 or rs79937737 with the disease risk of SLE was observed in Chinese population.
Focal Adhesion Kinases in Adhesion Structures and Disease
Authors: Eleniste Pierre P. , Bruzzaniti Angela
Published: July 2012

Cell adhesion to the extracellular matrix (ECM) is essential for cell migration, proliferation, and embryonic development. Cells can contact the ECM through a wide range of matrix contact structures such as focal adhesions, podosomes, and invadopodia. Although they are different in structural design and basic function, they share common remodeling proteins such as integrins, talin, paxillin, and the tyrosine kinases FAK, Pyk2, and Src. In this paper, we compare and contrast the basic organization and role of focal adhesions, podosomes, and invadopodia in different cells. In addition, we discuss the role of the tyrosine kinases, FAK, Pyk2, and Src, which are critical for the function of the different adhesion structures. Finally, we discuss the essential role of these tyrosine kinases from the perspective of human diseases.