A novel method for the reinforcement of harp soundboard     

Takuya Gunji  Eiichi Obataya  Hidefumi Yamauchi  Kenzo Aoyama 《Journal of Wood Science》2012,58(4):369-372

The effects of a carbon fiber-reinforced plastic (CFRP) overlay on the wooden soundboard of a harp were compared to those of conventional veneer reinforcement with respect to the vibrational properties and bending strength. CFRP reinforcement has a minimal effect on the vibrational properties of the soundboard in its width direction, whereas conventional veneer reinforcement significantly reduces the acoustic conversion efficiency of the soundboard. The CFRP-reinforced soundboard also has sufficient bending strength in its longitudinal direction. These results indicate that CFRP is a promising material for the reinforcement of the wooden soundboards of harps to minimize the reduction of the sound amplitude.  相似文献   

Anti-acne activity of tannin-related compounds isolated from Terminalia laxiflora     

Ali Mahmoud Muddathir  Kosei Yamauchi  Tohru Mitsunaga 《Journal of Wood Science》2013,59(5):426-431

In our investigation to find out new anti-acne agent, we focused on Terminalia laxiflora Engl & Diels (Combretaceae) methanolic wood extract, which has been selected during previous screening experiments for anti-acne agents, which included 29 species of Sudanese medicinal plants. Based on the biologically guided fractionation using an antibacterial assay against Propionibacterium acnes, a lipase inhibitory assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity assay; five tannin-related compounds were isolated, such as ellagic acid, flavogallonic acid dilactone, terchebulin and gallic acid. Terchebulin showed good antibacterial activity; minimum inhibitory concentration (MIC) = 125 μg/ml and minimum bactericidal concentration (MBC) = 250 μg/ml. Gallic acid exhibited lipase inhibitory activity with IC₅₀ value of 149.3 μM, which showed strong inhibition compared with terchebulin, IC₅₀ 260.7 μM. However, all compounds exhibited better or equal DPPH radical scavenging activity to (+)-catechin as positive control. Ellagic acid and terchebulin showed the best DPPH radical scavenging activities, IC₅₀ 4.86 and 4.90 μM, respectively. This study demonstrated that terchebulin has potentiality as an anti-acne agent.  相似文献   

Effects of dietary red pepper on egg yolk colour and histological intestinal morphology in laying hens     

K. Lokaewmanee  K. Yamauchi  N. Okuda 《Journal of animal physiology and animal nutrition》2013,97(5):986-995

To evaluate the effect of three kinds of red pepper supplementation ‘Kagawa Hontaka’ produced at Shiwaku Islands (KHS), Miki (KHM) and Takanotsume (TKT) on production performance, egg quality and intestinal histology in laying hens. A total of 32 laying hens (39 weeks of age) were randomly allotted to four groups, each comprising eight hens. Birds were fed a basal diet supplemented with red pepper at 0% (control), 0.5% KHS, 0.5% KHM and 0.5% TKT, respectively. Compared with the control group, no significant difference (p > 0.05) in feed consumption, final body weight, hen‐day production, egg mass, feed efficiency, shell‐breaking strength, shell thickness, shell ratio, albumen ratio, yolk ratio and Haugh units was observed among the experimental groups. Roche yolk colour fan (RYCF) value increased significantly in all experimental groups (p < 0.05). Furthermore, the KHS and KHM groups showed higher RYCF values than the TKT group (p < 0.05). Spectrophotometric measurements of yolk colour, redness (a*) and yellow index (YI) values were higher in the KHS and KHM groups (p < 0.0001). The yellowness (b*) value was lower in the TKT group (p < 0.05). The lightness (L*) value was lower in the KHS and KHM groups (p < 0.05). Villus height, villus area, cell area and cell mitosis in all intestinal segments tended to be higher in all experimental groups. Jejunal cell area and cell mitosis were higher in experimental groups than in the control group (p < 0.05). The cells on the villus tip surface were protuberated in all experimental groups. In conclusion, the KHS, KHM and TKT groups showed hypertrophied intestinal villi and epithelial cell functions. These results indicate that dietary red pepper has stimulating effect on intestinal villi and the structure of epithelial cells, and the 0.5% KHS and KHM groups improved in egg yolk colour.  相似文献   

Three‐dimensional CT examination of the forefoot and hindfoot of the hippopotamus and tapir during a semiaquatic walking     

Hideki Endo  Masataka Yoshida  Truong Son Nguyen  Yuki Akiba  Masahiro Takeda  Kohei Kudo 《Anatomia, histologia, embryologia》2019,48(1):3-11

Semiaquatic walking has resulted in the evolution of functional and morphological changes in various hoofed mammals, such as hippopotamus and Brazilian tapir. The biomechanics of skilful walking in wetlands or at the bottom of a waterbody involve the medio‐lateral opening and closing of the feet to effectively support and stabilize the body on soft ground and to reduce the water resistance during recovery stroke, respectively. We demonstrate that the opening and closing of the feet in hippopotamus and Brazilian tapir are mediated by the adduction and abduction of the most medial and lateral phalanges from the CT examination. The axial toes, metacarpals and metatarsals do not contribute to changes in the width and shape of the feet, unlike the medial and lateral toes. We suggest that this semiaquatic walking motion is derived from the original terrestrial mode of locomotion, in contrast to the highly functional swimming motion using webs or fins in morphologically modified feet and tail. From the present data we demonstrate that semiaquatic locomotion evolved due to the acquisition of adductor–abductor mobility in the phalanges of the most medial and lateral digits, as shown in hippopotamus and Brazilian tapir.  相似文献   

Drought-induced root plasticity of two upland NERICA varieties under conditions with contrasting soil depth characteristics     

Daniel Makori Menge  Emi Kameoka  Mana Kano-Nakata  Akira Yamauchi  Shuichi Asanuma  Hidetoshi Asai 《Plant Production Science》2016,19(3):389-400

To identify differences in root plasticity patterns of two upland New Rice for Africa (NERICA) varieties, NERICA 1 and 4, in response to drought under conditions with contrasting soil profile characteristics, soil moisture gradients were imposed using a sloping bed system with depths ranging 30–65 cm and a line-source sprinkler system with a uniformly shallow soil layer of 20 cm depth. Varietal differences in shoot and root growths were identified only under moderate drought conditions, 11–18% v/v soil moisture content. Further, under moderate drought soil conditions where roots could penetrate into the deep soil layer, deep root development was greater in NERICA 4 than in NERICA 1, which contributed to maintaining dry matter production. However, under soil conditions with underground impediment to deep root development, higher shoot dry weight was noted for NERICA 1 than for NERICA 4 at 11–18% v/v soil moisture content, which was attributed to increased lateral root development in the shallow soil layer in NERICA 1. Enhanced lateral root development in the 0–20-cm soil layer was identified in NERICA 1 even under soil conditions without an impediment to deep root development; however, this did not contribute to maintaining dry matter production in upland rice. Thus, we show different root developmental traits associated with drought avoidance in the two NERICA varieties, and that desirable root traits for upland rice cultivation vary depending on the target soil environment, such as the distribution of soil moisture and root penetration resistance.  相似文献   

Wheat yellow mosaic virus resistance in wheat cultivar Madsen acts in roots but not in leaves     

Cheng Liu  Takako Suzuki  Kohei Mishina  Antje Habekuss  Angelika Ziegler  Chao Li  Shun Sakuma  Guoxiong Chen  Mohammad Pourkheirandish  Takao Komatsuda 《Journal of General Plant Pathology》2016,82(5):261-267

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Erratum to: Cesium adsorption from aqueous solutions onto Japanese oak charcoal III: effects of water-extraction treatment     

Shigeru Yamauchi  Takayuki Yamagishi  Kazuko Kirikoshi  Mitsuyoshi Yatagai 《Journal of Wood Science》2016,62(6):567-567

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A bronchopulmonary artery fistula in a horse     

Yuto SANO  Hikaru KUWAJIMA  Hiroki KANAI  Chiemi BABA  Kohei AZAMI  Kazuya MATSUDA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(8):1225

A 24-year-old, Thoroughbred gelding presented with difficulty breathing for a few days and intermittent nose bleeding before dying. At necropsy, the bronchoesophageal artery and the bronchial artery that flowed into the left anterior lobe were tortuous and dilated, and it was found that dilated tortuous branches of the bronchial artery ran over the dorsal and ventral surfaces of the left anterior lobe. Histopathologically, an anastomosis between a muscular artery and an elastic artery were demonstrated, which were identified as bronchial and pulmonary arteries, respectively. Based on the gross and histopathological findings, a bronchopulmonary artery fistula was diagnosed. To the best of our knowledge, this is the first case report of a pulmonary vascular anastomosis in a horse.  相似文献   

Estimation of stiffness and strength in timber knee joints with adhesive and verification by experiment     

Masahiro Noguchi  Kohei Komatsu 《Journal of Wood Science》2006,52(5):411-421

The use of adhesive joints is gradually increasing, especially those with glued-in steel rods (GIRs). There are, however, some problems with the design methods when used for moment-transmitting applications. In this article, design methods for GIRs and cross-lapped glued joints (CLJs) are proposed. For CLJs, we made a hypothesis that both rotational deformation of CLJ and stress of the glue line occurred with bending and shearing deformation of the timber. Using this hypothesis and Kelvin’s theorem, a mechanical model of CLJ is proposed. For GIRs, the axial stress component of the rod and the lateral stress component of the rod were taken into account using the theory of a beam on an elastic foundation. From the comparisons between calculations and experimental results, it was recognized that the stiffness and strength of CLJs and GIRs could be predicted precisely using our proposed models.  相似文献   

Development of a joint system using a compressed wooden fastener I: evaluation of pull-out and rotation performance for a column—sill joint     

Kiho Jung  Akihisa Kitamori  Kohei Komatsu 《Journal of Wood Science》2009,55(4):273-282

Compressed wooden plates and dowels were used to connect members in post-and-beam structures as a substitute for a steel fastener. In order to take advantage of the characteristic properties of compressed wood and to achieve optimum joint performance, two compressed wooden plates were used in each joint to give multiple shear planes for each compressed wooden dowel. Consequently, this type of joint showed very good properties in pull-out and momen-trotation performance, and its engineering design could be further optimized. This joint is expected to be introduced to many kinds of structural systems, including long-span frame structures made of domestic timber found in Japanese residential houses.  相似文献