排序方式: 共有103条查询结果,搜索用时 15 毫秒
91.
Renato G. Reyes Fumio Eguchi Tomoaki Iijima Miyato Higaki 《Journal of Wood Science》1998,44(5):401-407
A series of experiments on the preparation and regeneration of protoplasts from hyphal strands ofVolvariella volvacea (Bull. ex. Fr.) Singer were conducted with the aim of optimizing the conditions for its efficient regeneration. One commercial (Vvcl) and two wild (EAAC-0001 and EAAC-0002) strains ofV. volvacea from the Philippines were used and subjected to varying conditions to determine the most efficient means for regeneration of their protoplasts. The effects of age and type of strain, pH, type and concentration of osmotic stabilizer, enzymatic composition, treatment time, temperature, reciprocal frequency during enzymatic lysis of the cell wall, and centrifugation conditions were investigated. Results showed that the three strains ofV. volvacea had varying responses in terms of yield, size, and ability of their protoplasts to regenerate into the protoplast regeneration medium. Among the three strains, EAAC-0002 had the highest rate of regeneration. The 5-day-old culture ofV. volvacea, when subjected to a combination of 2% Novozyme 234 and 0.2% chitinase in 0.6M mannitol (pH 6.0) for 3 h at 30°C, 90 strokes/min and centrifuged at 1100 g for 10 min; produced an efficient yield of protoplasts with a relatively high regeneration rate.Part of this paper was presented at the 47th annual meeting of the Japan Wood Research Society, Kochi, Japan, April 2–5, 1997 相似文献
92.
Wataru Aoyama Shinya Sasaki Shigeki Matsumura Thoru Mitsunaga Hirofumi Hirai Yuji Tsutsumi Tomoaki Nishida 《Journal of Wood Science》2002,48(6):497-504
Two peroxidases, CWPO-A and CWPO-C, were isolated from the cell walls of poplar (Populus alba L.) callus culture. The cationic CWPO-C showed a strong preference for sinapyl alcohol over coniferyl alcohol as substrate. Thus, the monolignol utilization of CWPO-C is unique compared with other peroxidases, including anionic CWPO-A and horseradish peroxidase (HRP). CWPO-C polymerized oligomeric sinapyl alcohol (S-oligo) and sinapyl alcohol, producing a polymer of greater molecular weight. In contrast, HRP, which is specific to coniferyl alcohol, produced sinapyl alcohol dimers, rather than catalyzing polymerization. Adding coniferyl alcohol as a radical mediator in the HRP-mediated reaction did not result in S-oligo polymerization. This report shows that CWPO-C is an isoenzyme specific to sinapyl alcohol that polymerizes oligomeric lignols. Its catalytic activity toward oligomeric lignols may be related to the lignification of angiosperm woody plant cell walls.Part of this study was presented at the 45th Lignin Symposium, Matsuyama, October 2000 相似文献
93.
94.
Nishimura J Dewa Y Jin M Saegusa Y Kawai M Kemmochi S Shimamoto K Harada T Itoh T Shima T Shibutani M Mitsumori K 《Journal of toxicologic pathology》2009,22(4):255-261
To clarify the modifying effect of N-Acetyl-L-Cysteine (NAC), which has antioxidative ability, on hepatocarcinogenesis promoted by fenofibrate (FF), a peroxisome proliferator-activated receptor (PPAR) alpha agonist , male F344/N rats were administered a single intraperitoneal injection of N-diethylnitrosamine (DEN) as an initiator followed by administration of a diet containing 3,000 ppm of FF for 16 weeks. Two-thirds partial hepatectomy was performed 1 week after the FF treatment. Additionally, NAC treatments for 14 weeks from 2 weeks after the FF treatment were performed. Although the expression level of tumor protein p53 (Tp53) mRNA decreased in the DEN+FF+NAC group as compared with that in the DEN+FF group, no significant differences between the DEN+FF and DEN+FF+NAC groups were observed in the number of hepatocellular altered foci and activities of hepatocellular proliferation. In addition, the results of an antioxidant enzyme assay and measurement of the amounts of total glutathione in the liver revealed no significant difference between the DEN+FF and DEN+FF+NAC groups; although no significant differences were observed in many genes between the DEN+FF and DEN+FF+NAC groups, only glutathione peroxidase 2 (Gpx2) mRNA increased in the DEN+FF+NAC group as compared with the DEN+FF group. The results under the present experimental conditions indicate no obvious modifying effect of NAC on liver tumor promotion by FF in rats. 相似文献
95.
96.
Tri Winarni Agustini Toru Suzuki Tomoaki Hagiwara Shoichiro Ishizaki Munehiko Tanaka Rikuo Takai 《Fisheries Science》2001,67(2):306-313
SUMMARY: The study on K value change at low temperature storage had been carried out down to a temperature of −40°C, however, there was no evidence about this reaction rate if the temperature were lowered below the storage temperature normally used especially for tuna meat (−60o C). The rate of K value change ( kf ) of yellowfin tuna ( Thunnus albacares ) meat was determined during storage at a wide temperature range (20°C to −84°C). The logarithm of K '(= 100 − K value) was used in this study and its plot against storage time yielded a straight line, which indicated an apparent first-order reaction for all temperature storage. Furthermore, physicochemical characterization of water in tuna muscle was carried out using Differential Scanning Calorimetry (DSC) at very low temperature. The temperature dependence of this reaction was analyzed by an Arrhenius's plot that resulted in two break points. The first break point occurring at freezing point might be due to the freeze effect. The second break point was at −10°C. The reaction rate change steeply declined at the temperature range of −70°C to −84°C, and was thought to be related to glass transition which may occur in the fish sample. 相似文献
97.
Katsunobu Ehara Yuka Iiyoshi Yuji Tsutsumi Tomoaki Nishida 《Journal of Wood Science》2000,46(2):180-183
A possible role of Tween 80 in the polyethylene degradation by manganese peroxidase (MnP) and the basis of the MnP action in the absence of hydrogen peroxide were investigated. The MnP activity in the system was retained its maximum level for 6 days in the presence of Tween 80. Tween 20 and CHAPSO stabilized MnP in the system similarly to Tween 80, and these surfactants also promote the polyethylene degradation. The system containing malonate buffer, Mn(II), and MnP produced Mn(III) in the absence of hydrogen peroxide, but the effect of Tween 80 addition on Mn(III) production in the absence of hydrogen peroxide was small. The results show that Mn(III) is generated by the MnP action initiated and amplified by the decomposition of malonate by Mn(III) and that a surfactant such as Tween 80 is required to stabilize MnP in the system.This study was presented in part at the 42nd lignin symposium, Sapporo, October 1997 and the 43rd lignin symposium, Fuchu, Tokyo, October 1998 相似文献
98.
Hua?Jiang Wei?Wei Tomoaki?Saiki Hiromu?Kawakita Kenji?Watanabe Mamoru?SatoEmail author 《Journal of General Plant Pathology》2004,70(3):168-173
Distribution patterns of mulberry dwarf (MD) phytoplasma were investigated in several organs of dwarf-diseased mulberry trees using direct and nested polymerase chain reactions and electron microscopy. MD phytoplasma was detected in the root of all MD-diseased trees collected from overwintering to before sprouting in the cold district; however, it was not always found in winter buds of the same trees. On the other hand, MD phytoplasma was also detected frequently in reproductive organs, such as flowers (female and bisexual flowerets), fruits (catkins), and seed coats, from a single diseased tree, although the distribution patterns were not uniform. In addition, MD phytoplasma was verified to move into roots from ground plant organs after an artificial inoculation test using the leafhopper Hishimonoides sellatiformis as a vector. 相似文献
99.
Shimazaki T Nakamura S Taguchi K Inoue Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(2):263-266
Bovine viral diarrhea virus (BVDV) has been segregated into two genotypes, type 1 and type 2. To determine the efficacy of the commercially available bovine viral diarrhea type 1 vaccine used in Japan against BVDV type 2, calves were infected with BVDV type 2 strain 890 4 weeks after administration of the vaccine. The vaccinated calves did not develop any clinical signs and hematological changes such as observed in unvaccinated calves after the challenge. Furthermore, the challenge virus was not recovered from the vaccinated calves throughout the duration of the experiment, whereas it was recovered from all unvaccinated calves. The bovine viral diarrhea vaccine used in Japan is efficacious against infection with BVDV type 2 strain 890. 相似文献
100.
Yuzo Furuta Toshihiko Okuyama Keisuke Kojiro Yuka Miyoshi Tomoaki Kiryu 《Journal of Wood Science》2014,60(4):249-254
With the aim of obtaining findings on the dynamic properties of branches and their bases, as well as their support mechanisms, the present study examined the temperature dependence of the dynamic viscoelasticity of Japanese cypress samples saturated with water to clarify the responses in different regions, and identified factors influencing the characteristics. In the bases of the branches: E′ sharply decreased at approximately room temperature and significantly decreased at around 20 and 60 °C; a peak and shoulder peak of E″ or tan δ were noted at around 20 °C, and there was another peak of tan δ at around 60–80 °C; and mechanical relaxation was noted at around 20 °C and 60–80 °C. On the other hand, in some regions, including the trunks, branches, and their bases, mechanical relaxation was only noted on the high-temperature side. However, boiling treatment with about 12 % weight loss inhibited mechanical relaxation, and there were decreases in E′, E″, and tan δ at approximately room temperature. The bases of the branches of Japanese cypress are considered to develop its elasticity and viscosity to tolerate external stress by accumulating an extract, which enhances the strength of lignin. 相似文献