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1.
Naruyuki Kamo Mitsuo Higuchi Takehiro Yoshimatsu Yukiko Ohara Mitsuhiro Morita 《Journal of Wood Science》2002,48(6):491-496
This study reexamined the kinetics of the condensation reactions of hydroxymethylphenols with the purpose of elucidating the reaction mechanisms. This report discusses experimental results on the self-condensations of 2,4-dihydroxymethylphenols (2,4-DHMP) and 2,4,6-trihydroxymethylphenol (THMP), focusing on the order of reaction. The relations between the initial rates of reaction and the initial concentrations of reactants were investigated. Results quite different from those of previous reports were obtained. The order of reaction of the selfcondensation of 2,4-DHMP was found to be 1.1, which did not change with the alkali/2,4-DHMP molar ratio. The order of reaction of the self-condensation of THMP was found to vary with both the concentration of THMP and the alkali/THMP molar ratio. In the region of THMP concentrations above 1.5mol/l, the order of reaction was confirmed to be 2.0, which did not change with the alkali/THMP molar ratio. In the region of THMP concentrations below 1.0mol/l, the order of reaction varied with the alkali/THMP molar ratio, showing fractional numbers of 1.2–1.6. These results indicate that unimolecular reaction(s) and bimolecular reaction(s) take place simultaneously as the ratedetermining step in the condensation reactions of 2,4-DHMP and THMP and that the reaction mechanism changes with the species of reactant and, in some cases, with the reaction conditions.Part of this study was presented at the Wood Adhesives 2000 symposium, South Lake Tahoe, Nevada, USA, June 2000 相似文献
2.
Naruyuki?Kamo Hiroyuki?Okamura Mitsuo?Higuchi Mitsuhiro?MoritaEmail author 《Journal of Wood Science》2004,50(3):236-241
Propylene carbonate (PC) is known as one of the cure accelerators for alkaline phenol–formaldehyde resins. To elucidate the cure-acceleration mechanisms, the effects of PC on the condensation reactions of monomeric hydroxymethylphenols (HMPs) were investigated and compared with those of PC hydrolysate, sodium bicarbonate (NaHCO3) and ethyl formate. Immediately after the reaction started, PC, decomposing itself simultaneously, accelerated the formation of the ortho-para methylene-bonded dimer of 2,4,6-trihydroxymethylphenol. This effect of PC was very similar to that of ethyl formate. To the contrary, PC hydrolysate accelerated the formation of the para-para methylene-bonded dimer throughout the course of the reaction. This effect of PC hydrolysate was identical to that of NaHCO3. These results indicate that PC increases the reactivity of the ortho-hydroxymethyl group, presumably through transesterification. On the other hand, NaHCO3 is formed by the hydrolysis of PC or decomposition of the transesterified HMPs and it increases the reactivity of the para-hydroxymethyl group. 相似文献
3.
Transgene expression was evaluated for Gladiolus plants transformed with either the CaMV 35S, double CaMV 35S, rolD, or Arabidopsis UBQ3 promoter controlling the uidA or bean yellow mosaic virus coat protein gene in either the sense or antisense orientation to determine differences in expression for plants grown in the greenhouse and outdoors for two years. There was more variability in GUS expression when plants were grown outdoors than in the greenhouse for two years. Four of the six transformed plant lines with the UBQ3, rolD, and CaMV 35S promoters grown outdoors showed significant differences in GUS expression from year to year as compared to two of the six lines with the UBQ3 and rolD promoters grown in the greenhouse. When grown the same year, two plant lines with the CaMV 35S and one line with the rolD promoter showed 2–16× higher levels of GUS expression outdoors than in the greenhouse, and one plant line with the UBQ3 promoter had 31× higher GUS expression in the greenhouse instead of outdoors. Three of six plant lines transformed with the bean yellow mosaic virus coat protein gene in either the sense or antisense orientation under control of the double CaMV 35S promoter showed obvious transgene expression as compared to three lines that did not show expression or negligible expression for both years when plants were grown both outdoors and in the greenhouse. This study verified long-term gene expression, rather than silencing, for Gladiolus plants when grown outdoors and in the greenhouse from year to year. 相似文献
4.
Naruyuki Kamo Jun Tanaka Mitsuo Higuchi Tetsuo Kondo Mitsuhiro Morita 《Journal of Wood Science》2006,52(4):325-330
This article describes the catalytic effect of NaHCO3 on condensation reactions of monomeric hydroxymethylphenols (HMPs) to elucidate the cure-acceleration mechanism. By comparison
of the kinetics of self-condensations of HMPs, NaHCO3 was proved to increase the reactivity of para-hydroxymethyl groups. The changes of 13C nuclear magnetic resonance (NMR) chemical shifts on each HMP system with the additive indicated that the addition of NaHCO3 enhanced some molecular interactions between HMPs and NaHCO3, facilitating a resonance effect that might play a similar role in dissociation of the phenolic hydroxyl groups of HMPs.
In addition, computational modeling by molecular orbital calculations elucidated that hydrogen carbonate anion (HCO
3
−
) forms an interaction between either the para-hydroxymethyl group and the phenolic hydroxyl group or between the two para-hydroxymethyl groups of HMPs by hydrogen bonds. From the experimental results, the authors proposed the mechanism of the
catalytic action of NaHCO3: it appears to be due to the delocalization of an electron initiated by the interaction of the para-hydroxymethyl groups and the phenolic hydroxyl of HMPs with HCO
3
−
through hydrogen bonds, which results in facilitating the formation of active species. 相似文献
5.
6.
Macroalgae are one of potential sources for carotenoids, such as fucoxanthin, which are consumed by humans and animals. This carotenoid has been applied in both the pharmaceutical and food industries. In this study, extraction of fucoxanthin from wet brown seaweed Undaria pinnatifida (water content was 93.2%) was carried out with a simple method using liquefied dimethyl ether (DME) as an extractant in semi-continuous flow-type system. The extraction temperature and absolute pressure were 25 °C and 0.59 MPa, respectively. The liquefied DME was passed through the extractor that filled by U. pinnatifida at different time intervals. The time of experiment was only 43 min. The amount of fucoxanthin could approach to 390 μg/g dry of wet U. pinnatifida when the amount of DME used was 286 g. Compared with ethanol Soxhlet and supercritical CO2 extraction, which includes drying and cell disruption, the result was quite high. Thus, DME extraction process appears to be a good method for fucoxanthin recovery from U. pinnatifida with improved yields. 相似文献
7.
Monoclonal antibody to acetylcholine receptor: cell line established from thymus of patient with Myasthenia gravis 总被引：4，自引：0，他引：4
I Kamo S Furukawa A Tada Y Mano Y Iwasaki T Furuse N Ito K Hayashi E Satoyoshi 《Science (New York, N.Y.)》1982,215(4535):995-997
A human B cell line producing a monoclonal antibody to an antigenic determinant of acetylcholine receptors was established by cloning B cells that had been transformed in vitro by Epstein-Barr virus. The B cells were obtained from the thymus of a patient with myasthenia gravis. The antibody produced by the cell line precipitated acetylcholine receptors from denervated and innervated rat muscle and from human muscle, but did not show detectable response to the acetylcholine receptors from the electric organs of Narke japonica. The monoclonal antibody showed identical binding patterns in innervated and denervated rat muscles. Passive transfer of the monoclonal antibody into rats induced moderate muscle weakness and electromyographic changes characteristic of myasthenia gravis. 相似文献
8.
A new insight into cystatin C contained in milk basic protein to bone metabolism: Effects on osteoclasts and osteoblastic MC3T3‐E1 cells in vitro 
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下载免费PDF全文 Takehiko Yasueda Yusuke Abe Mayumi Shiba Yoshie Kamo Yasuyuki Seto 《Animal Science Journal》2018,89(7):1027-1032
A milk protein fraction possessing alkaline isoelectric points (milk basic protein [MBP]) improves bone metabolism in vivo, and it inhibits bone resorption by osteoclasts and promotes mouse osteoblastic MC3T3‐E1 cells proliferation in vitro. Cystatin C (CysC) is a component of MBP and shows bone resorption inhibitory activity. Therefore, it is likely that MBP with higher CysC content improves bone metabolism more effectively. In this study, we prepared MBP with low and high contents of CysC and compared its effects on bone metabolism with standard MBP in vitro. Our results showed that the CysC content in MBP was positively related to not only bone resorption inhibitory activity but also MC3T3‐E1 cells proliferative activity. Furthermore, purified CysC stimulated MC3T3‐E1 cells proliferation. These results indicate that CysC contributes to promotion of MC3T3‐E1 cells proliferation, and MBP with higher CysC content shows enhanced bone resorption inhibitory activity and MC3T3‐E1 cells proliferative activity. CysC is considered an important factor in the effect on bone metabolism of MBP. 相似文献
9.
Masahiro Inagaki Yoshiyuki Inagaki Koichi Kamo Jupiri Titin 《Journal of Forest Research》2009,14(3):178-182
We measured fine-root production at Acacia mangium (AM), Swietenia macrophylla (SM), and Araucaria cunninghamii (AC) sites in response to nitrogen (N) and phosphorus (P) application using the root-ingrowth core method for a period of
5 months in Sabah, Malaysia. Root growth increased significantly using a combined N and P application at the AM site, whereas
it did not increase at the SM and AC sites. The number of nodules at the AM site increased significantly following N application
and the combined application of N and P. Root production was not significantly enhanced by nutrient application at the SM
and AC sites. At the AM site, both P and N were in high demand despite a larger N pool compared with at the SM and AC sites.
These results can be explained by the larger nutrient demand by legumes. We conclude that both N and P is limiting for AM
plantations under natural conditions and that N fertilization may be more effective than expected, depending on the site conditions. 相似文献
10.
Dilip K. Lakshman Ruchi Pandey Kathryn Kamo Gary Bauchan Amitava Mitra 《European journal of plant pathology / European Foundation for Plant Pathology》2012,133(3):729-738
Fusarium rot caused by Fusarium oxysporum f.sp. gladioli (Fog) is one of the most serious diseases of Gladiolus, both in the field and in bulbs in storage. In order to study the mechanisms of pathogenesis of this fungus, we have transformed Fog with Agrobacterium tumefaciens binary vectors containing the hygromycin B phosphotransferase (hph) gene and fluorescence reporter genes EGFP (green), EYFP (yellow) or ECFP (cyan) using the AGL-1 strain of A. tumefaciens. Hygromycin B (100 μg/ml) resistant colonies were observed only when acetosyringone was added to the co-cultivation medium. Transformed colonies are more clearly visible when co-cultivated on cellophane membrane than on Hybond -N+ membrane. Transformed lines were stably maintained through four serial passages on medium containing hygromycin B, and they expressed green, yellow or cyano fluorescence. PCR with hph-specific primers and Southern blotting with an hph-specific probe were positive for HygR lines but not for the untransformed isolate. The cyano fluorescence of the ECFP-transformed isolate was clearly distinguishable from the green autofluorescence of Gladiolus roots, signifying the potential of these lines for further histopathological investigations. Transformed lines will be useful for identifying pathogenicity related genes, screening transgenic resistance, and in studies of host-pathogen interactions. 相似文献