Studies on developmental potentials of bisected mouse embryos in vitro and in vivo     

A Nakagawa  Y Takahashi  H Kanagawa 《The Japanese journal of veterinary research》1985,33(3-4):121-133

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Protection against Fasciola gigantica infection in rats administered metacercarial antigens     

S Yoshihara  M Nakagawa  H Suda 《Research in veterinary science》1985,39(3):383-384

Immature worms were recovered from the liver parenchyma of rats which received extracts of metacercariae or adult worms of Fasciola gigantica, after challenge infection. When resistance was assessed by counting the number of immature worms, exposure of the animals to extracts of these two stages of the flukes conferred a significant degree of protection against challenge with F gigantica metacercariae. Rats given the extract of metacercariae were more resistant to infection than rats immunised with the extract of adult worms.  相似文献   

Spatially distributed morphological characteristics of macropores in forest soils of Hitachi Ohta Experimental Watershed, Japan   总被引：1，自引：0，他引：1  

Shoji Noguchi  Yoshio Tsuboyama  Roy C. Sidle  Ikuhiro Hosoda 《Journal of Forest Research》1997,2(4):207-215

Morphological characteristics of macropores in forest soil profiles were investigated at Hitachi Ohta Experimental Watershed in Japan. Nine individual profiles at different locations (various spatial scales in a catchment) and twenty profiles at one site (a small spatial scale) were excavated to the bedrock to investigate density, origin, diameter, direction, and gradient of macropores. Macropore densities in a soil profile ranged from 3.5 to 29.1 per m and from 5.4 to 75.1 per m², respectively. Subsurface erosion, root channels, and interactions between subsurface erosion and root channels accounted for 36.9, 36.5, and 19.0%, of the described macropores. The mean macropore diameter in organic-rich soil layer (17–20 mm) was larger than in the B horizon (11–14 mm) at both spatial scales. The dominant gradients of all macropores in the organic-rich soil layer and B horizon were at negative oblique angles. Approximately 90% of the macropores in the organic-rich soil layer and approximately 80% of the macropores in the B horizon fell within the range between −50 and 50 degree planar direction. Subsurface flow and root systems are believed to play important roles in determining the morphological characteristics of macropores. These characteristics appear to have variable influences in different soil horizons rather than at different spatial scales. A part of this paper was presented at the 103th (1992) and 105th (1994) Annual Meetings of Japanese Forestry Society.  相似文献   

Effect of water potential on fruit body formation ofLentinula edodes in sawdust-based substrate     

Shoji Ohga 《Journal of Wood Science》1999,45(4):337-342

The influence of substrate water potential () on the growth and fruiting of three genotypes of shiitake (Lentinula edodes) was investigated. A slight reduction of (–0.5MPa) stimulated mycelial and colony growth on liquid, agar, and sawdust-based substrates.L. edodes has been found to grow well at a around –0.5 MPa, which corresponds to a moisture content around 55%. A small decrease in at the final vegetative growth phase had positive effects on flush quantity. The substrate was significantly affected by the interaction between genotypes and spawn run time. The of well-colonized mature substrate was –0.7MPa before and –4.OMPa after the fruiting. The rose again to –0.7MPa during rapid absorbance of water by soaking, and this rise was repeated during the second and third flushes. It is suggested that the water-holding capacity of a substrate is related to culture maturity. Excellent water-providing capacity (higher) is expected in the substrate of well-matured cultures with a high density of mycelial colonization.Part of this paper was presented at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 1996  相似文献   

The regeneration characteristics of Picea jezoensis and Abies sachalinensis on cut stumps in the sub-boreal forests of Hokkaido Tokyo University Forest     

Masahiko Nakagawa  Akio Kurahashi  Taizo Hogetsu 《Forest Ecology and Management》2003,180(1-3):353-359

The regeneration characteristics of Picea jezoensis Carr. and Abies sachalinensis Masters on cut stumps in natural forest under selection cutting and natural regeneration were studied in a sub-boreal forest of the Hokkaido Tokyo University Forest. The following points were investigated: (1) what decay class of cut stumps are suitable for regeneration of the two conifer species; (2) what part, either a root collar or a cut surface, of a cut stump is suitable for regeneration; and (3) what percentages of cut stumps support conifer seedlings. The percentages of cut stumps that supported conifer seedlings increased as the decay class advanced, but slightly decreased in the latest stage of decay class, V. Both P. jezoensis and A. sachalinensis seedling densities per cut stump and per square meter of cut stumps increased as the decay class advanced. Some root collars in decay class IV supported A. sachalinensis seedlings, but few supported P. jezoensis. Densities of P. jezoensis per cut surface and per square meter of cut surface in decay class IV were higher than those of A. sachalinensis. On the other hand, densities of A. sachalinensis per root collar and per square meter of root collar in decay class IV were higher than those of P. jezoensis. Cut stumps in advanced decay classes are more suitable for regeneration of P. jezoensis and A. sachalinensis than those in early decay classes. Whereas a cut surface is more suitable for regeneration of P. jezoensis, a root collar is more suitable for regeneration of A. sachalinensis. Cut stumps are not sufficient to ensure enough conifer regeneration because not all conifer cut stumps in advanced decay classes support conifer seedlings.  相似文献   

Induction of cell proliferation in the rat liver by the short-term administration of ethyl tertiary-butyl ether     

Anna Kakehashi  Akihiro Hagiwara  Norio Imai  Min Wei  Shoji Fukushima  Hideki Wanibuchi 《Journal of toxicologic pathology》2015,28(1):27-32

In the present study, in continuation of our previous experiment in order to investigate the mode of action (MOA) of ethyl tertiary-butyl ether (ETBE) hepatotumorigenicity in rats, we aimed to examine alterations in cell proliferation, that are induced by short-term administration of ETBE. F344 rats were administered ETBE at doses of 0, and 1,000 mg/kg body weight twice a day by gavage for 3, 10, 17 and 28 days. It was found that the previously observed significant increase of P450 total content and hydroxyl radical levels after 7 days of ETBE administration, and 8-OHdG formation at day 14, accompanied by accumulation of CYP2B1/2B2, CYP3A1/3A2, CYP2C6, CYP2E1 and CYP1A1 and downregulation of DNA oxoguanine glycosylase 1, was preceded by induction of cell proliferation at day 3. Furthermore, we observed an increase in regenerative cell proliferation as a result of ETBE treatment at day 28, followed by induction of cell cycle arrest and apoptosis by day 14. These results indicated that short-term administration of ETBE led to a significant early increase in cell proliferation activity associated with induction of oxidative stress, and to a regenerative cell proliferation as an adaptive response, which could contribute to the hepatotumorigenicity of ETBE in rats.  相似文献   

Comparison of the canine corneal epithelial cell sheets cultivated from limbal stem cells on canine amniotic membrane,atelocollagen gel,and temperature‐responsive culture dish          下载免费PDF全文

Eunryel Nam  Naoki Fujita  Maresuke Morita  Keiko Tsuzuki  Hsing Yi Lin  Cheng Shu Chung  Takayuki Nakagawa  Ryohei Nishimura 《Veterinary ophthalmology》2015,18(4):317-325

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Evaluation of visual impact of multiple image characteristics observed in edge-grain patterns     

Masashi Nakamura  Saki Nakagawa  Takato Nakano 《Journal of Wood Science》2015,61(1):19-27

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Preparation, characterization, and antioxidative effects of oligomeric proanthocyanidin-L-cysteine complexes     

Fujii H  Nakagawa T  Nishioka H  Sato E  Hirose A  Ueno Y  Sun B  Yokozawa T  Nonaka G 《Journal of agricultural and food chemistry》2007,55(4):1525-1531

Controlled acid-catalyzed degradation of proanthocyanidin polymers in grape seeds together with L-cysteine led to oligomeric proanthocyanidin-L-cysteine complexes along with monomeric flavan-3-ol derivatives being isolated, and their structures were confirmed on the basis of spectroscopic data and by chemical means. In addition, comparative studies on the antioxidative and survival effects of oligomeric proanthocyanidin-L-cysteine complexes and proanthocyanidin polymers were performed. The oligomeric proanthocyanidin-L-cysteine complexes showed higher bioavailability and antioxidant capacity and enhanced survival time in the animal test groups. In addition, it is suggested that the oligomeric complexes may help to prevent oxidative stress and may reduce free radical production.  相似文献   

Individual-level analysis of damage to residual trees after single-tree selection harvesting in northern Japanese mixedwood stands     

Shinichi Tatsumi  Toshiaki Owari  Hisatomi Kasahara  Yuji Nakagawa 《Journal of Forest Research》2014,19(4):369-378

Quantifying tree damage and mortality caused by single-tree selection harvesting is critical to understanding postharvest forest dynamics and management. In this study, we quantified the effects of tree size and species and the distance from residual trees to felled trees and skid trails on damage to residual trees and mortality in mixed coniferous–broadleaved stands of Hokkaido, northern Japan. Among the 4,961 trees that we studied, 373 (7.5 %) were damaged, and 148 of these trees (3.0 %) died during or immediately after logging. Hierarchical Bayesian modeling showed that the risk of damage to residual trees increased with increasing size of the felled trees and with increasing proximity to felled trees and skid trails. Smaller residual trees had the greatest risk of damage. Species differed in their susceptibility to damage; Abies sachalinensis (Fr. Schm.) Masters and Picea jezoensis (Sieb. et Zucc.) Carr. were the most susceptible species in our sample plots. Smaller damaged trees had the highest risk of mortality. The damaged trees that did not die at the time of logging had a higher risk of postharvest mortality than undamaged trees. Our results indicate that, to minimize logging-induced damage and mortality: (1) the spatial arrangement of skid trails should be optimized and fixed, (2) the risk of skidding damage should be considered before marking the trees to be harvested and choosing the felling direction, and (3) logging operators should be instructed to avoid damaging small trees, especially those of the species that are most susceptible to damage.  相似文献