A Major Intestinal Catabolite of Quercetin Glycosides, 3-Hydroxyphenylacetic Acid,Protects the Hepatocytes from the Acetaldehyde-Induced Cytotoxicity through the Enhancement of the Total Aldehyde Dehydrogenase Activity

Aldehyde dehydrogenases (ALDHs) are the major enzyme superfamily for the aldehyde metabolism. Since the ALDH polymorphism leads to the accumulation of acetaldehyde, we considered that the enhancement of the liver ALDH activity by certain food ingredients could help prevent alcohol-induced chronic diseases. Here, we evaluated the modulating effects of 3-hydroxyphenylacetic acid (OPAC), the major metabolite of quercetin glycosides, on the ALDH activity and acetaldehyde-induced cytotoxicity in the cultured cell models. OPAC significantly enhanced the total ALDH activity not only in mouse hepatoma Hepa1c1c7 cells, but also in human hepatoma HepG2 cells. OPAC significantly increased not only the nuclear level of aryl hydrocarbon receptor (AhR), but also the AhR-dependent reporter gene expression, though not the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent one. The pretreatment of OPAC at the concentration required for the ALDH upregulation completely inhibited the acetaldehyde-induced cytotoxicity. Silencing AhR impaired the resistant effect of OPAC against acetaldehyde. These results strongly suggested that OPAC protects the cells from the acetaldehyde-induced cytotoxicity, mainly through the AhR-dependent and Nrf2-independent enhancement of the total ALDH activity. Our findings suggest that OPAC has a protective potential in hepatocyte models and could offer a new preventive possibility of quercetin glycosides for targeting alcohol-induced chronic diseases.     

Thermal conductivity of Na2O–B2O3–SiO2 melts

Borosilicate glasses are candidate materials for the immobilization of high-level radioactive waste. The values of thermal conductivity of different borosilicate melts are thus indispensable information when optimizing the temperature distribution in a glass melting furnace. In this study, the thermal effusivity of Na₂O–B₂O₃–SiO₂ melts was measured using a front heating–front detection laser-flash method. The thermal conductivity, which can be obtained by combining the measured thermal effusivity with the specific heat capacity and density, was calculated using the least-squares method; the values for the Na₂O–B₂O₃–SiO₂ melts either slightly decreased linearly with increasing temperature or remained almost constant over the investigated temperature range. The values of thermal conductivity of the Na₂O–B₂O₃–SiO₂ melts were higher than those of B₂O₃–SiO₂ melts and lower than those of CaO–B₂O₃–SiO₂ melts. Furthermore, the thermal conductivity of the Na₂O–B₂O₃–SiO₂ melts was compared with those of the B₂O₃–SiO₂ and CaO–B₂O₃–SiO₂ samples.     

Present status and practical issues on dosimetry for the lens of the eye at JAEA MOX fuel facilities

ABSTRACT

At Japan Atomic Energy Agency (JAEA) MOX fuel facilities, a worker usually wears a protective lead apron; therefore, the dose to the lens of the eye (lens dose) outside the apron is higher than that to the torso. To estimate the potential impact on the current facility operation of the International Commission of Radiological Protection (ICRP)-proposed lens dose limit reduction from 150 mSv/y to average 20 mSv/y, the authors carried out an analysis on the past dose records for the workers over the last 18 years. Of a total of 4,312 workers’ records analyzed, two workers’ annual lens doses exceeded the lowered limit of 20 mSv (23.3 mSv and 20.7 mSv), although the maximum effective dose was below 10 mSv in each case. These compiled dose data reveal that in the glovebox and related operations the lens dose will be a limiting factor in radiological control under the newly lowered dose limit. To ensure that the number of workers with an annual lens dose greater than 15 mSv (approximately 0.6% of the workers) is kept to a minimum, the implementation of an administrative control level for the lens dose is considered.     

Frequency Response Characteristics of Bender Element Test System Identified by Frequency-Swept Signal Input —Influence on Accuracy of Received Waveform Reconstruction—

On the basis of the method for received waveform reconstruction that the authors had previously proposed on bender element test, this paper discusses the required characteristics of frequency response of the test system and frequency-swept signal, which are essential for the method, from the view point of reconstruction accuracy. In order to argue influence on characteristics of frequency response, frequency responses of several bender element test systems are experimentally identified by using eleven kinds of frequency-swept signals. Test results show that the frequency response of the system is substantially determined by the kinds of sample and identification of frequency response is affected by characteristics of input frequency-swept signal. Then reconstructed received waveform is calculated and compared to observed waveform. A normalized cross-correlation function is proposed to estimate quantitatively the degree of similarity between two waveforms and applied to the reconstructed and observed waveforms. This comparative analysis reveals that accurate identification of frequency response in a given frequency range leads to accurate waveform reconstruction. Also, test results show an additional advantage of this reconstruction technique in a noisy environment.     

Precipitates caused by prolonged high-temperature annealing in floating zone silicon wafer grown from Czochralski single-crystal rod

The behavior of precipitates in a floating zone silicon crystal produced from a Czochralski single-crystal ingot has been studied. Large precipitates of α-Si₃N₄ crystal, having a dimension of about 2 μm, were formed at the mid-depth in the wafer by annealing at a high temperature in an ambient N₂ (70%)+O₂ (30%) atmosphere. The number of precipitates detected by cross-sectional X-ray topography increased with increasing annealing time. Because preannealing accompanying silicon oxidation in an ambient Ar+O₂ atmosphere prevented the precipitates formation, interstitial silicon is considered to eliminate the origin of precipitate.     

Measurement of effective atomic numbers using energy-resolved computed tomography

For ion radiation therapy, the measurement of effective atomic numbers, Z_eff, is necessary to know the material distribution in a human body; the range of ions entering the human body is influenced by the material distribution along their paths. Z_eff, however, cannot be measured at hospitals because monochromatic X-rays with different energies are necessary and are used only at synchrotron facilities. To make Z_eff measurements at hand, we propose energy-resolved computed tomography (CT) using a “transXend detector”. By assigning two narrow energy ranges in the unfolding process of the data obtained by the transXend detector, Z_eff for acrylic and aluminum can be estimated by energy-resolved CT. The estimated Z_eff are compared with those obtained by dual-energy and monochromatic X-ray CT.     

Shape control of TIG arc plasma by cusp-type magnetic field with permanent magnet

The shape of arc plasma in gas-shielded arc welding is an important factor for the quality and efficiency of the welding. The arc plasma changes its shape by an external magnetic field because the arc is a flow of electricity and is subjected to the electromagnetic force. In this study, we examined the control of arc plasma by a cusp-type magnetic field. The field produces a high and low magnetic area alternatively, and changes the cross-section of the arc plasma from a circular to an elliptical shape. The previous study using solenoid coils to produce a cusp-type magnetic field reported that magnetized arc plasma provided deeper penetration. However, the solenoid device developed for the cusp magnetic field was too large in comparison with the size of the welding torch used for production welding. Therefore, this study investigated the magnetic control of arc plasma with permanent magnets that have recently become smaller in size and higher in intensity. Theoretical analysis model was constructed to determine the optimum arrangement of the magnets. This analysis requires a three-dimensional numerical model because the temperature-, velocity-, and electromagnetic fields of arc plasma change three-dimensionally by the additional magnetic field. It was analytically and experimentally shown in TIG arc welding that the arc shape could be elliptical cross-section even using the permanent magnets. Furthermore, our analysis showed that the effective magnetization direction of magnets was vertical, and this result was confirmed experimentally. As a result, we obtained the good bead appearance in the high-speed welding with this magnetic control.     

Characterization and thermodynamic study of humic acid in deep groundwater at Horonobe,Hokkaido, Japan

In this study, humic substances (humic acid and fulvic acid) were isolated from deep groundwater at ?350 m depth of Horonobe, Hokkaido, Japan to compare the characteristic property and reaction mechanism with generic humic acid isolated from surface soils. The size distributions of Horonobe humic substances were analyzed by size exclusion chromatography, flow-field flow fractionation, and total organic carbon measurement with ultrafiltration. All of them indicated small molecular weight and particle size of Horonobe humic acid in comparison with generic humic acids. Additionally, the simple protonation behavior of Horonobe humic substances similar to benzoic acid and/or phenol was revealed by thermodynamic quantities obtained by potentiometry and calorimetry. Consequently, molecular size and the reaction mechanism of Horonobe humic substances are different from generic humic acids, due to the characteristic origin.