Point-Focusing Electromagnetic-Acoustic Transducer for Crack Inspection

Stress corrosion cracking in stainless-steel pipes is a critical failure in atomic power plants and chemical plants. In ultrasonic testing, piezoelectric transducers are generally used, in which reproducibility of amplitude measurements is not necessarily high because of effects of coupling materials and contacting conditions between the transducers and specimens. Comparing to the transducers, an electromagnetic acoustic transducer (EMAT) requires no coupling materials and is less sensitive to the contacting conditions, making the reproducibility higher. However, lower signal to noise (S/N) ratio has been a disadvantage. For increasing the S/N ratio, we developed a point-focusing EMAT (PF-EMAT) [1]. It generated shear-vertical (SV) waves from concentric line sources on a top surface of a specimen. Coil configuration of the EMAT was designed so that the SV waves were accumulated in phase at a focal point on the bottom surface, which increased the S/N ratio and improved the spatial resolution. We have designed PF-EMATs operated at different frequencies, and applied to artificially fabricated defects on stainless steel specimens. In this presentation, we show the results, and discuss availability of the PF-EMAT to crack inspection

The Change of Factory Village in the 19th Century Britain

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Photoluminescence, morphology, and structure of hydrothermal ZnO implanted at room temperature with 60 keV Sn+ ions

Hydrothermal ZnO wafers implanted at room temperature with 60 keV Sn^+ ions are examined by means of photoluminescence (PL), atomic force spectroscopy (AFM), and X-ray diffractometry techniques. The PL intensity significantly decreases in the wafers implanted to doses of 4.1 × 10^[13] ions/cm^2 and higher. The AFM measurements indicate that surface roughness variation is not the cause of the significant decrease in PL intensity. Furthermore, the PL deep level (DL) band peak blueshifts after illuminating the implanted samples with the He-Cd laser 325 nm line; meanwhile, the DL band intensity first increases and then decreases with illumination time. These abnormal behaviors of the DL band are discussed

An analytical method for measuring α-amylase activity in starch-containing foods

The quality of starch-containing foods may be significantly impaired by contamination with very small amounts of α-amylase, which can enzymatically hydrolyze the starch and cause viscosity loss. Thus, for quality control, it is necessary to have an analytical method that can measure low amylase activity. We developed a sensitive analytical method for measuring the activity of α-amylase (from Bacillus subtilis) in starch-containing foods. The method consists of six steps: (1) crude extraction of α-amylase by centrifugation and filtration; (2) α-amylase purification by desalting and anion-exchange chromatography; (3) reaction of the purified amylase with boron-dipyrromethene (BODIPY)-labeled substrate, which releases a fluorescent fragment upon digestion of the substrate, thus avoiding interference from starch derivatives in the sample; (4) stopping the reaction with acetonitrile; (5) reversed-phase solid-phase extraction of the fluorescent substrate to remove contaminating dye and impurities; and (6) separation and measurement of BODIPY fluorescence by HPLC. The proposed method could quantify α-amylase activities as low as 10mU/mL, which is enough to reduce the viscosity of starch-containing foods. © 2012 John Wiley & Sons, Ltd

カフェイン酸フェネチルエステル（CAPE）がラット象牙芽細胞様細胞のVEGF発現と産生に与える影響

Caffeic acid phenethyl ester (CAPE), the main component of propolis, has various biological activities including anti-inflammatory effect and wound healing promotion. Odontoblasts located in the outermost layer of dental pulp play crucial roles such as production of growth factors and formation of hard tissue termed reparative dentin in host defense against dental caries. In this study, we investigated the effects of CAPE on the upregulation of vascular endothelial growth factor (VEGF) and calcification activities of odontoblasts, leading to development of novel therapy for dental pulp inflammation caused by dental caries. CAPE significantly induced mRNA expression and production of VEGF in rat clonal odontoblast-like KN-3 cells cultured in normal medium or osteogenic induction medium. CAPE treatment enhanced nuclear factor-kappa B (NF-κB) transcription factor activation, and furthermore, the specific inhibitor of NF-κB significantly reduced VEGF production. The expression of VEGF receptor- (VEGFR-) 2, not VEGFR-1, was up regulated in KN-3 cells treated with CAPE. In addition, VEGF significantly increased mineralization activity in KN-3 cells. These findings suggest that CAPE might be useful as a novel biological material for the dental pulp conservative therapy

Age- and sun exposure-dependent differences in 8-hydroxy-2'-deoxyguanosine and Nε-(carboxymethyl)lysine in human epidermis

Aging and exposure to sunlight are two major factors in the deterioration of skin function. In this study, thirty-six fixed human skin samples from sun-exposed and unexposed areas from young and old individuals were used to evaluate the localization of oxidative stress according to levels and distribution of 8-hydroxy-2'-deoxyguanosine and Nε-(carboxymethyl)lysine in samples using immunohistochemistry. In the epidermis of the young, negligible amounts of 8-hydroxy-2'-deoxyguanosine and Nε-(carboxymethyl)lysine were detected in unexposed areas, whereas nuclear 8-hydroxy-2'-deoxyguanosine and cytoplasmic Nε-(carboxymethyl)lysine were increased in the lower epidermis in sun-exposed areas. In contrast, the aged presented prominent nuclear 8-hydroxy-2'-deoxyguanosine and nuclear Nε-(carboxymethyl)lysine in the epidermis of unexposed areas, concomitant with dermal increase in Nε-(carboxymethyl)lysine. However, the immunostaining of 8-hydroxy-2'-deoxyguanosine and Nε-(carboxymethyl)lysine revealed a decrease in the epidermis of sun-exposed areas in the aged. These results suggest an age-dependent difference in the adaptation and protective mechanisms of the epidermis against sunlight-associated oxidative stress, thus necessitating distinct standards for evaluation in each age group. Further investigation is warranted to elucidate underlying molecular mechanisms