Vibrational properties of wetwood of todomatsu (<Emphasis Type="Italic">Abies sachalinensis</Emphasis>) at high temperature     

Hisashi Ohsaki  Yoshitaka Kubojima  Mario Tonosaki  Masamitsu Ohta 《Journal of Wood Science》2007,53(2):134-138

The object of this study was to understand precisely the drying characteristics of wetwood of todomatsu (Abies sachalinensis Mast.). For this purpose, the vibrational properties of wetwood of todomatsu at high temperature were compared with those of normal parts that had lower green moisture content than the wetwood. Specimens were cut respectively from the wetwood and normal parts, and matched in the radial direction. The specimens and the measuring systems were placed in an electric drying oven and free-free vibration tests were conducted in the oven under absolutely dry conditions. The wetwood and the normal parts were tested separately. The temperature was raised from room temperature to 200°C and then lowered to 50°C in steps of 25°C. The specific Young’s modulus decreased with an increase in temperature during the heating process while it increased with the decreasing temperature during the cooling process. There was no significant difference in the specific Young’s modulus between the wetwood and the normal part at all tested temperatures. The loss tangent took a minimum value at about 100°C in both the heating and cooling processes. There was no significant difference in the loss tangent between the wetwood and the normal part. Thus, the elastic and viscoelastic behaviors of the wetwood appear to be similar to those of the normal part in the temperature range of an actual kiln-drying process.  相似文献   

Collapsing process simulations of timber structures under dynamic loading II: simplification and quantification of the calculating method     

Takafumi?NakagawaEmail author  Masamitsu?Ohta 《Journal of Wood Science》2003,49(6):499-504

In a previous paper we presented the efficacy of the extended distinct element method (EDEM) on the collapsing process simulation of timber-frame structures. The results obtained were qualitative, and the need for quantitative simulation was pointed out. In this report, we improved our simulating programs with the aim of establishing a quantitative simulation by EDEM. For this purpose, the parameters of the frame members (beam or column) were determined by comparing the simulated results of four-point bending tests with experimental results. Other parameters of plywood and joint members were determined by simulations of two rail shear and slip tests of joint parts, respectively. Using these parameters we made simulations of the collapsing process of an actual-size plywood-sheathed wall and at the same time carried out the experiments under similar conditions. Simulated load–displacement curves of the plywood-sheathed wall were similar to those obtained in the experiments, and the sequence of failure at nailed joints of the simulation model gave good agreement with that of the experimental collapsing processes. Using these processes, we believe that we established a basic quantitative simulation method to test the collapsing process of timber-frame structures.Part of this paper was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002; and at the 7th World Conference of Timber Engineering, Malaysia, August 2002  相似文献   

In vivo anti-influenza virus activity of an immunomodulatory acidic polysaccharide isolated from Cordyceps militaris grown on germinated soybeans   总被引：2，自引：0，他引：2  

Ohta Y  Lee JB  Hayashi K  Fujita A  Park DK  Hayashi T 《Journal of agricultural and food chemistry》2007,55(25):10194-10199

An acidic polysaccharide (APS) was isolated from the extract of Cordyceps militaris grown on germinated soybeans. Analyses of sugar composition indicated that APS consisted of d-galactose, L-arabinose, D-xylose, L-rhamnose, and D-galacturonic acid. On the basis of the result of methylation analysis, APS was considered to be mainly composed of Araf-(1-->, -->5)-Araf-(1-->, -->4)-Galp-(1--> and -->4)-GalAp-(1--> residues. When the polysaccharide was intranasally administered, it decreased virus titers in the bronchoalveolar lavage fluid and the lung of mice infected with influenza A virus and increased survival rate. Furthermore, APS increased TNF-alpha and IFN-gamma levels in mice when compared with those of untreated mice. APS enhanced nitric oxide (NO) production and induced iNOS mRNA and protein expressions in RAW 264.7 murine macrophage cells. The induction of mRNA expression of cytokines including IL-1beta, IL-6, IL-10, and TNF-alpha was also observed. These results demonstrated that APS might have beneficial therapeutic effects on influenza A virus infection at least in part by modulation of the immune function of macrophages.  相似文献   

Restricted localization of claudin-16 at the tight junction in the thick ascending limb of Henle's loop together with claudins 3, 4, and 10 in bovine nephrons     

Ohta H  Adachi H  Takiguchi M  Inaba M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(5):453-463

Claudin-16 is one of the tight junction protein claudins and has been shown to contribute to reabsorption of divalent cations in the human kidney. In cattle, total deficiency of claudin-16 causes severe renal tubular dysplasia without aberrant metabolic changes of divalent cations, suggesting that bovine claudin-16 has some roles in renal tubule formation and paracellular transport that are somewhat different from those expected from the pathology of human disease. As the first step to clarify these roles, we examined the expression and distribution of claudin-16 and several other major claudin subtypes, claudins 1-4 and 10, in bovine renal tubular segments by immunofluorescence microscopy. Claudin-16 was exclusively distributed to the tight junction in the tubular segment positive for Tamm-Horsfall glycoprotein, the thick ascending limb (TAL) of Henle's loop, and was found colocalized with claudins 3, 4, and 10. This study also demonstrates that bovine kidneys possess segment-specific expression patterns for claudins 2-4 and 10 that are different from those reported for mice. Particularly, distribution of claudin-4 in the TAL and distal convoluted tubules was characteristic of bovine nephrons as were differences in the expression patterns of claudins 2 and 3. These findings demonstrate that the total lack of claudin-16 in the TAL segment is the sole cause of renal tubular dysplasia in cattle and suggest that the tight junctions in distinct tubular segments including the TAL have barrier functions in paracellular permeability that are different among animal species.  相似文献   

Cardiovascular effects of continuous propofol infusion in horses     

Oku K  Ohta M  Katoh T  Moriyama H  Kusano K  Fujinaga T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(8):773-778

We examined the influence of propofol infusion on cardiovascular system at the rate of 0.14, 0.20 and 0.30 mg/kg/min in six adult Thoroughbred horses. The cardiovascular parameters were heart rate (HR), mean arterial pressure (MAP), mean right atrial pressure (MRAP), stroke volume (SV), cardiac output (CO), systemic vascular resistance (SVR), pre-ejection period (PEP) and ejection time (ET). In order to keep the ventilation conditions constantly, intermittent positive pressure ventilation was performed, and the partial arterial CO(2) pressure was maintained at 45 to 55 mmHg during maintenance anesthesia. SV showed a significant dose-dependent decrease however, CO did not show significant change. SVR decreased significantly at higher dose. PEP was prolonged and PEP/ET increased significantly at the highest dose. From these results, it became clear that SV decreases dose-dependently due to decrease of cardiac contractility during anesthesia with continuous propofol infusion in horses. On the other hand, since MAP and CO did not show significant changes, total intravenous anesthesia with propofol was suggested to be suitable for long-term anesthesia in horses.  相似文献   

Controlling the electronic structure of bilayer graphene     

Ohta T  Bostwick A  Seyller T  Horn K  Rotenberg E 《Science (New York, N.Y.)》2006,313(5789):951-954

We describe the synthesis of bilayer graphene thin films deposited on insulating silicon carbide and report the characterization of their electronic band structure using angle-resolved photoemission. By selectively adjusting the carrier concentration in each layer, changes in the Coulomb potential led to control of the gap between valence and conduction bands. This control over the band structure suggests the potential application of bilayer graphene to switching functions in atomic-scale electronic devices.  相似文献   

Hyperproduction and application of alpha-agarase to enzymatic enhancement of antioxidant activity of porphyran     

Hatada Y  Ohta Y  Horikoshi K 《Journal of agricultural and food chemistry》2006,54(26):9895-9900

The nucleotide sequence of the gene for the alpha-agarase, AgaA33, from Thalassomonas sp. strain JAMB-A33 was determined. The open reading frame for AgaA33 was revealed to encode 1463 amino acid residues. We succeeded in extracellular production of recombinant -agarase (AgaA33) efficiently using Bacillus subtilis as a host. This is the first report of recombinant production of -agarase. Furthermore, we demonstrated that hydrolysis of alpha-1,3 linkages in porphyran, a sulfated polysaccharide from marine red algae, by alpha-agarase is an important step for improvement of its antioxidant activity with regard to free-radical-scavenging capacity and superoxide radical anion scavenging activity, whereas the hydrolysis of beta-1,4 linkages in porphyran by beta-agarase did not increase on the antioxidant activity markedly.  相似文献   

Anisotropy and corotation of galactic cosmic rays     

Amenomori M  Ayabe S  Bi XJ  Chen D  Cui SW  Danzengluobu  Ding LK  Ding XH  Feng CF  Feng Z  Feng ZY  Gao XY  Geng QX  Guo HW  He HH  He M  Hibino K  Hotta N  Hu H  Hu HB  Huang J  Huang Q  Jia HY  Kajino F  Kasahara K  Katayose Y  Kato C  Kawata K  Labaciren  Le GM  Li AF  Li JY  Lou YQ  Lu H  Lu SL  Meng XR  Mizutani K  Mu J  Munakata K  Nagai A  Nanjo H  Nishizawa M  Ohnishi M  Ohta I  Onuma H  Ouchi T  Ozawa S  Ren JR  Saito T  Saito TY  Sakata M  Sako TK  Sasaki T  Shibata M  Shiomi A  Shirai T  Sugimoto H  Takita M  Tan YH  Tateyama N  Torii S 《Science (New York, N.Y.)》2006,314(5798):439-443

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.  相似文献   

Eye fatigue-reduction effect of wood rim cover on liquid crystal display     

Seiji Hirata  Isao Kageyama  Masamitsu Ohta 《Journal of Wood Science》2012,58(2):163-168

The purpose of this study is to confirm objectively by an instrumental measurement if there is less eye fatigue in VDT work when using a wood rim covered display than when using a plastic housing display. The subjects were 26 graduate and undergraduate university students. Each subject did the same 60-min VDT activity with both a plastic housing and wood-covered display. Before and after VDT activity, each subject’s near-point accommodation distance was measured by a near-point ruler. As a result, it was confirmed that variation rate of the near-point accommodation distance by the VDT work with the wood-covered display was smaller than with the plastic housing display. From sensory tests, progression of subjective symptoms such as eye pain and headache was less with the wood-covered display than with the plastic housing display.  相似文献   

Intestinal Tritrichomonas suis (=T. foetus) infection in Japanese cats     

Doi J  Hirota J  Morita A  Fukushima K  Kamijyo H  Ohta H  Yamasaki M  Takahashi T  Katakura K  Oku Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(4):413-417

Tritrichomonas suis (=T. foetus) has recently been reported to be a causative agent of chronic large-bowel diarrhea in cats. While the disease was previously attributed to Pentatrichomonas hominis, the etiologic agent for feline trichomonal diarrhea was identified as T. suis. Although feline trichomonosis due to T. suis has been reported at prevalences ranging from 14 to 31% in Europe and the U.S., no reports of the pathogen have been published to date in Japan. In 2008, however, we encountered a case of feline trichomonosis at the Veterinary Teaching Hospital of Hokkaido University. The parasite was identified as T. suis by nested PCR amplification of partial internal transcribed spacer region 1 and 5.8S ribosomal RNA gene sequences with T. suis-specific primers and DNA sequencing of the amplified products. We then conducted surveys for feline trichomonosis in three different animal hospitals using either cultivation and/or PCR-based assays. The results revealed that 13 of 147 samples (8.8%) were positive for T. suis, and that 5 of the 13 infected cats, which ranged between 1 month and 7.5 years-old, showed chronic diarrhea. Seven of the infected cats were purebred and 6 were mixed breed. These findings suggested that feline trichomonosis is prevalent in Japan, and that T. suis may play a role as a causative agent of feline chronic diarrhea.  相似文献