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51.
Kana Yamashita Yasuhiko Hirakawa Shuetsu Saito Motoyoshi Ikeda Masamitsu Ohta 《Journal of Wood Science》2012,58(5):375-382
To investigate the wood properties affecting the internal-check variation in boxed-heart square timber of sugi (Cryptomeria japonica), two cultivars, yabukuguri and kumotooshi were kiln-dried together by the high-temperature setting method and their internal checks were compared. There was a difference in the area of internal checks between the cultivars. Kumotooshi formed a larger area of internal checks, which was thought to be affected by the larger tangential shrinkage of kumotooshi. The number, total length, and total area of internal checks were significantly correlated with tangential shrinkage. The area of internal checks around the pith was also larger for kumotooshi, which might be affected by the larger tangential shrinkage in the core part of kumotooshi. The results supported that tangential shrinkage should be one of the important properties affecting the internal-check variation of sugi boxed-heart square timber. 相似文献
52.
To clarify if eye fatigue is lessened when looking at wood, we carried out objective examinations using a near-point ruler and also performed sensory evaluations. Visual contact target materials were a white plastic panel, a black plastic panel or a wood panel which had Japanese ash flat grain surface. Each size of the materials was 140 × 280 mm. Test subjects were 30 undergraduate and graduate students. Each subject’s visual distance to a panel was 40–50 cm. The results showed that subjects suffered from more eye fatigue when looking at white and black plastic panels compared to looking at the wood panel in objective examinations. In sensory evaluations, almost all subjective symptom items for eyes and head progressed when subjects looked at white plastic panel or black plastic panel. However, almost no progression of subjective symptoms was noted when subjects looked at the wood panel. In both objective examinations and sensory evaluations, eye fatigue was most highly associated with the black plastic panel, followed by the white plastic panel and, finally, the wood panel. 相似文献
53.
Masaru Sakamoto Yasuomi Tada Hitoshi Nakayashiki Yukio Tosa Shigeyuki Mayama 《Journal of General Plant Pathology》2005,71(6):387-394
Reactive oxygen species (ROS) are thought to be involved in various forms of programmed cell death (PCD) in animal and plant
cells. PCD, along with the production of ROS, occurs during plant–pathogen interactions. Here we show that victorin, a host-specific
toxin produced by Cochliobolus victoriae, which causes victoria blight of oats, induces two phases of intracellular ROS production in victorin-sensitive oat mesophyll
cells. The initial production of ROS is restricted at mitochondria and not accompanied with cellular oxidative damage. Later
production of ROS is dispersed into cells concomitant with lipid peroxidation, chloroplast dysfunction, and cell death. Superoxide
dismutase can clearly suppress the initial ROS production and delay the progression of cell death. These data indicate that
the initial ROS production may be involved in the cell death induction process, and the later ROS production may play important
roles in events leading to cellular disruption. 相似文献
54.
Keiichiro Nishimura Toshiji Tada Ryo Shimizu Akira Ohoka 《Pest management science》1999,55(4):446-451
N-Alkylated analogs (C1–C3) of an N-arylcarbamoylpyrazoline were prepared. The introduction of these alkyl groups completely changed the crystal structure in respect of the torsion angle of the amide C–N bond of the non-alkyl compound. The introduction of methyl and ethyl groups slightly, and that of an isopropyl group markedly, decreased insecticidal activity against American cockroaches and house flies. Conformational analyses of the compounds suggested that the insecticidally active conformer of this class of compounds is in the anti-position regarding the N′–C(=O) and N-aryl bonds in which the non-alkyl compound is energetically the most stable. The most stable conformers of the alkylated compounds are in the syn-position, and these compounds would interact with target sites in the less stable anti-form. © 1999 Society of Chemical Industry 相似文献
55.
Iio A Yokoyama A Takano M Nakamura T Fukasawa H Nose Y Kakubari Y 《Tree physiology》2008,28(9):1421-1429
During the summers (July and August) of 2002-2005, we measured interannual variation in maximum carboxylation rate (V(cmax)) within a Fagus crenata Blume crown in relation to climate variables such as air temperature, daytime vapor pressure deficit (VPD) and daily photosynthetic photon flux, leaf nitrogen per unit area (N(a)) and leaf mass per unit area (LMA). Climatic conditions in the summers of 2002-2004 differed markedly, with warm and dry atmospheric conditions in 2002, cool, humid and cloudy conditions in 2003, and warm clear conditions in 2004. Conditions in summer 2005 were intermediate between those of summers 2002 and 2003, and similar to recent (8-year) means. In July, marked interannual variation in V(cmax) was mainly observed in leaves in the high-light environment (relative photon flux > 50%) within the crown. At the crown top, V(cmax) was about twofold higher in 2002 than in 2003, and V(cmax) values in 2004 and 2005 were intermediate between those in 2002 and 2003. In August, although interannual variation in V(cmax) among the years 2003, 2004 and 2005 was less, marked variation between 2002 and the other study years was evident. Multiple regression analysis of V(cmax) against the climate variables revealed that VPD of the previous 10-30 days had a significant influence on variability in V(cmax). Neither N(a), LMA nor leaf CO(2) conductance from the stomata to the carboxylation site explained the variability in V(cmax). Our results indicate that the long-term climatic response of V(cmax) should be considered when estimating forest carbon gain across the year. 相似文献
56.
Sitka spruce (Picea sitchensis Carr.) wood was heated for 0.5–16.Oh at temperatures of 120°–200°C in nitrogen gas or air. The values for Young's modulus, shear modulus, and loss tangent were measured by free-free flexural vibration tests. X-ray diffractometry was carried out to estimate the crystallinity index and crystallite width. The results obtained are as follows: (1) Density decreased at higher temperatures and longer heating times. The specific Young's modulus, specific shear modulus, crystallinity index, and crystallite width increased during the initial stage and were constant after this stage at 120°C and 160°C, whereas they increased during the initial stage and decreased later when the temperature was high. Loss tangent in the longitudinal direction increased under all conditions, whereas that in the radial direction increased at 120°C and decreased at 160°C and 200°C. (2) From the relation between Young's modulus and moisture content, it can be safely said that Young's modulus is increased by the crystallization and the decrement in equilibrium moisture content, and that crystallization (rather than degradation) is predominant at the initial stage of the heat treatment, whereas the latter is predominant as the heating time increases. (3) It is implied that the specific Young's modulus, specific shear modulus, crystallinity index, and crystallite width decreased more in air than in nitrogen gas because of oxidation in air.This study was presented in part at the 43th Annual Meeting of Japan Wood Research Society at Morioka, August 1993, the 44th Annual Meeting of Japan Wood Research Society at Nara, April 1994, and the 45th Annual Meeting of Japan Wood Research Society at Tokyo, April 1995 相似文献
57.
Hiroshi Yoshihara Yoshitaka Kubojima Koji Nagaoka Masamitsu Ohta 《Journal of Wood Science》1998,44(1):15-20
When measuring the shear modulus of wood by static bending tests, the basic theory is dependent on Timoshenko's bending theory. The shear modulus obtained by static bending is a much smaller value than that derived by other methods. We examined the applicability of Timoshenko's theory and propose an empirical equation that can derive the shear modulus properly. Three softwoods and three hardwoods were used for the tests. First, the Young's modulus and shear modulus were measured by free-free flexural vibration tests. Then the three-point static bending tests were undertaken, varying the depth/span ratios. Additionally, the bending tests were simulated by the finite element method (FEM). The shear moduli obtained by these methods were then compared. The deflection behaviors in static bending were not expressed by the original Timoshenko bending theory because of the stress distortion near the loading point. Based on the experimental results and numerical calculations, we modified the original Timoshenko bending equation. When using our modified equation the stress concentration must be carefully taken into account. 相似文献
58.
Hiroyuki Enari Yoshinori Takahashi Masataka Kawarasaki Motohiko Tada Kuniaki Tatsuta 《Fisheries Science》2008,74(4):911-920
ABSTRACT: The salmon peptide digested from salmon muscle showed a strong inhibitory activity against the angiotensin I-converting enzyme (ACE). The antihypertensive effect of the salmon peptide on spontaneously hypertensive rats (SHR) was examined. After the single intravenous administration of the salmon peptide at a dose of 30 mg/kg body weight, the systolic blood pressure (SBP) was significantly reduced against the control. Further, a double-blind, placebo-controlled, parallel-group study determined the efficacy of the salmon peptide in mild hypertensive subjects. The SBP, after a 1.0 g of salmon peptide intake, was significantly reduced at 4 weeks after the intake, and 2 weeks after the intake finished, compared to the value before ingestion. Bioassay-guided separation of the salmon peptide, using a combination of column chromatographic techniques, led to the identification of 20 active di- and tri-peptides, including Ile-Val-Phe and Phe-Ile-Ala as two new ACE inhibitory tripeptides. Ile-Trp had the strongest ACE inhibitory activity (IC50 = 1.2 μM) in vitro , and contributed 5.2% to the total ACE inhibitory activity. The salmon peptide and Ile-Trp showed a digestive resistance by in vitro assay, which mimicked the digestive organ, and had no affinity for factors related to blood pressure regulation, except for the ACE inhibitory activity. 相似文献
59.
The transition of fetal haematopoietic sites in mice was examined histologically from 12.5-day embryos (E12.5) until 10 days of age (D10), and the expression of the adhesive molecules VCAM-1 and fibronectin was examined immunohistologically. Erythropoiesis occurred in the liver (E12.5-18.5), spleen (E18.5-D4) and bone marrow (D6-10), in that sequence. Even at D10, some erythropoiesis occurred in the liver, and more so in the spleen, although the active haematopoietic site was the bone marrow. Similarly, granulopoiesis of neutrophils occurred in the liver, spleen and bone marrow in turn. Granulopoiesis still occurred in the spleen at D10, but no neutrophils were found in the liver after D4. VCAM-1 appeared in the liver, spleen and bone marrow in parallel with active erythropoiesis and granulopoiesis. The co-expression of VCAM-1 and fibronectin was recognized in the endothelial cells of the sinus at the onset of haematopoiesis. This study showed that haematopoiesis in the liver, spleen and bone marrow overlapped peri-natally, although it shifted sequentially. VCAM-1 appears to be closely associated with erythropoiesis and granulopoiesis, and the co-expression of VCAM-1 and fibronectin plays a role in inducing haematopoietic stem cells to move to the tissues. 相似文献
60.
Yukie Tada Norio Yano Hiroshi Takahashi Katsuhiro Yuzawa Hiroshi Ando Yoshikazu Kubo Akemichi Nagasawa Akio Ogata Dai Nakae 《Journal of toxicologic pathology》2012,25(4):233-239
Iron nanomaterials are of considerable interest for application to
nanotechnology-related fields including environmental catalysis, biomedical imaging, drug
delivery and hyperthermia, because of their superparamagnetic characteristics and high
catalytic abilities. However, information about potential risks of iron nanomaterials is
limited. The present study assessed pulmonary responses to a single intratracheal spray
instillation of triiron tetraoxide nanoparticles (magnetite) in rats. Ten-week-old male
and female Fischer 344 rats (n=5/group) were exposed to a single intratracheal spray
instillation of 0 (vehicle), 5.0, 15.0 or 45.0 mg/kg body weight (BW) of magnetite. After
14 days, the rats were sacrificed, and biological consequences were investigated. The lung
weights of the 15.0 and 45.0 mg/kg BW male and female groups were significantly higher
than those of the control groups. The lungs of treated rats showed enlargement and black
patches originating from the color of magnetite. The typical histopathological changes in
the lungs of the treated rats included infiltration of macrophages phagocytosing
magnetite, inflammatory cell infiltration, granuloma formation and an increase of goblet
cells in the bronchial epithelium. The results clearly show that instilled magnetite
causes foreign body inflammatory and granulating lesions in the lung. These pulmonary
responses occur in a dose-dependent manner in association with the increase in lung
weight. 相似文献