Detection of a deep 3-microm absorption feature in the spectrum of Amalthea (JV)     

Takato N  Bus SJ  Terada H  Pyo TS  Kobayashi N 《Science (New York, N.Y.)》2004,306(5705):2224-2227

Near-infrared spectra of Jupiter's small inner satellites Amalthea and Thebe are similar to those of D-type asteroids in the 0.8- to 2.5-micrometer wavelength range. A deep absorption feature is detected at 3 micrometers in the spectra of the trailing side of Amalthea, which is similar to that of the non-ice components of Callisto and can be attributed to hydrous minerals. These surface materials cannot be explained if the satellite formed at its present orbit by accreting from a circumjovian nebula. Amalthea and Thebe may be the remnants of Jupiter's inflowing building blocks that formed in the outer part or outside of the circumjovian nebula.  相似文献   

Time course of changes in antioxidant activity of milk from dairy cows fed a trehalose‐supplemented diet     

Naoto AOKI  Kan SATO  Shuhei KANDA  Kazuhisa MUKAI  Yoshiaki OBARA  Hisao ITABASHI 《Animal Science Journal》2013,84(1):42-47

This study was to investigate the time course of changes to the antioxidant activity of milk from cows fed a trehalose‐supplemented diet, and to determine possible underlying mechanisms for observed changes. Six Holstein cows were used, and subjected to two experimental feeding periods consisting of a 1% trehalose‐supplemented diet for 10 days, followed by a basal diet only (no trehalose) for 10 days. 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activities in milk were gradually increased during the trehalose supplementation period and were highest at the end of the second period. However, trehalose was not detected in the milk and plasma of dairy cows fed a diet supplemented with trehalose for 10 days, indicating that the increased antioxidant activity in the milk of trehalose‐fed cows is not due to the direct transfer of trehalose to the milk. Plasma DPPH activities exhibited a similar time course to that seen for milk. Relative superoxide dismutase (SOD) activities in the rumen were higher 3 days after the end of trehalose supplementation than at any other time during the experimental periods. These results suggested that the improved antioxidant activity in milk and plasma of cows fed a trehalose‐supplemented diet was due to improved ruminal relative SOD activity.  相似文献   

Hammer blot-mediated RNA extraction: an inexpensive,labor-saving method to extract RNA for plant virus detection     

Md. Shamim Akhter  Takashi Yaeno  Naoto Yamaoka  Masamichi Nishiguchi  Kappei Kobayashi 《Journal of General Plant Pathology》2016,82(5):268-272

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Improved method for in situ biolistic transformation to analyze barley–powdery mildew interactions     

Miki Wahara  Chie Inoue  Tomohiro Kohguchi  Koreyuki Sugai  Kappei Kobayashi  Masamichi Nishiguchi  Naoto Yamaoka  Takashi Yaeno 《Journal of General Plant Pathology》2017,83(3):140-146

Although the use of stable transformants is indispensable to elucidate mechanisms underlying molecular plant–pathogen interactions, this approach remains difficult to apply to crops. Alternatively, biolistic transformation has often been used as a transient expression method in various plants. In this study, we developed a method for in situ biolistic transformation without separating leaves from barley seedlings by using a hand-held particle bombardment system because unwounded leaves are preferable for analyzing interactions between barley and Blumeria graminis f. sp. hordei which requires healthy living cells. As a result, we found that the infection rate in intact leaves was higher than in separated leaves and that the transformation efficiencies in leaves were higher when plants were grown in vermiculite rather than in culture soil. Furthermore, we determined the appropriate inoculation time after bombardment to analyze the incompatible interaction and successfully monitored the gradual occurrence of cell death over time. Our system was suitable for relatively long-term follow-up analysis of the fate of each single cell during plant–pathogen interactions.  相似文献   

Efficient bioethanol production from water hyacinth Eichhornia crassipes by both preparation of the saccharified solution and selection of fermenting yeasts     

Toshiyuki Takagi  Motoharu Uchida  Ryoji Matsushima  Masami Ishida  Naoto Urano 《Fisheries Science》2012,78(4):905-910

Although water hyacinth is an adventive aquatic plant that threatens the Japanese ecosystem, its high growth rate may be a benefit in terms of its potential as a raw material for the production of bioethanol. In our study, water hyacinth was saccharified with 3?% (v/v) sulfuric acid and subjected to cellulase treatments to determine optimum bioethanol production conditions. The original saccharified solution yielded both glucose at 5.3?±?0.2?g/l and reducing sugars at 9.7?±?0.1?g/l. Concentration of the saccharified solution under vacuum at 70?°C yielded both glucose at 21.5?±?2.9?g/l and reducing sugars at 33.3?±?2.1?g/l. An aquatic yeast Saccharomyces cerevisiae TY2 produced ethanol at 9.6?±?1.1?g/l from the concentrated saccharified solution. In comparison, Ogawa et al. (Afr J Microbiol Res 2:110?C113, 2008) reported that this yeast produced 0.90?g/l and that the production of bioethanol was about 11.2-fold lower than that obtained in our study. These results suggest that refinement of the saccharification process and application of the selected yeast could improve the efficiency of obtaining bioethanol from the water hyacinth.  相似文献   

Transgene manipulation in rainbow trout using Cre recombinase     

Sachi Kume  Naoto Katayama  Kensuke Ichida  Shoko Hattori-Ihara  Kazue Nagasawa  Goro Yoshizaki 《Fisheries Science》2014,80(4):767-773

Cre/loxP-mediated cell targeting is considered to be a powerful tool for biotechnology in farmed fish. As a first step toward establishing cell targeting in salmonids, we analyzed the functionality of the Cre/loxP system in rainbow trout. We first established stable transgenic strains carrying the DsRed gene, which was flanked by loxP sites and further spliced with the EGFP gene. By microinjecting Cre complementary RNA (cRNA) into fertilized eggs of the transgenic trout, the functionality of the Cre/loxP system was evaluated. The results showed that all of the embryos exhibited green fluorescence in at least some of their cells. While 19 out of 20 embryos comprised cells showing both green and red fluorescence, the remaining embryo showed only green fluorescence. Polymerase chain reaction (PCR) using primers designed to recognize sequences outside of the two loxP sites revealed that, in addition to long intact fragments, the 19 individuals carried short fragments that were equivalent in length to the loxP-excised fragments. The remaining green embryo carried only this short fragment. DNA sequencing of the short fragment revealed that it lacked the DNA fragments flanking the loxP sites and the spliced fragments did not contain any sequence rearrangements. These results suggest that the Cre/loxP system is functional in rainbow trout.  相似文献   

Molecular cloning and biochemical characterization of medaka (Oryzias latipes) lysosomal neu4 sialidase     

Kazuhiro Shiozaki  Sena Ryuzono  Naoto Matsushita  Asami Ikeda  Kazuki Takeshita  Petros Kingstone Chigwechokha  Masaharu Komatsu  Taeko Miyagi 《Fish physiology and biochemistry》2014,40(5):1461-1472

Glycoconjugates are known to be involved in many physiological events in vertebrates. Sialidase is one of the glycosidases, which removes sialic acid from glycoconjugates. In mammals, the properties and physiological functions of sialidases have been investigated, while there is little understanding of fish sialidase. Here, to investigate the significance of fish neu4 sialidase, neu4 gene was cloned from medaka brain mRNA and identified. Sialidase-specific motifs (GPG, YRVP and Asp-Box) were well conserved in the medaka neu4 polypeptide. Optimal pH of medaka neu4 sialidase was 4.6, but its activity was sustained even at neutral and weak alkaline pH. The neu4 considerably cleaved sialic acid from 4-methylumbelliferyl-N-acetyl-α-d-neuraminic acid and sialyllactose, but not from ganglioside and fetuin, which are good substrates for human NEU4. neu4 activity was mostly detected in mitochondria/lysosome fraction after biochemical fractionation, and indirect immunofluorescence assays revealed neu4 localization in lysosome in neu4 overexpressed cells. Next, developmental change in medaka neu4 and other sialidase mRNA levels were estimated by real-time PCR. Each sialidases showed different expression patterns in embryonic development: neu4 was up-regulated at late developmental stage in embryo, and neu3a mRNA level was quite high in 0.5 dpf. On the other hand, neu3b expression was drastically increased after hatching, suggesting that each sialidase may play a different role in embryonic development.  相似文献   

Purification and enzymatic properties of a neutral metalloprotease produced from the cold-adapted <Emphasis Type="Italic">Vibrio</Emphasis> species Pr21 isolated from deep seawater in Sagami Bay     

Masami Ishida  Chie Yoshida-Mishima  Yosuke Maeda  Masashi Yamamoto  Ryo Tsuda  Haruto Ishii  Naoto Urano  Hiroshi Kabasawa 《Fisheries Science》2016,82(4):675-683

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Mechanism-based CYP2D6 inactivation by acridone alkaloids of Indonesian medicinal plant Lunasia amara     

Takahashi N  Subehan  Kadota S  Tezuka Y 《Fitoterapia》2012,83(4):774-779

Fourteen acridone alkaloids isolated from Lunasia amara Blanco were tested for their mechanism-based inhibition on human liver microsomal dextromethorphan O-demethylation activity, a prototype marker for cytochrome P450 2D6 (CYP2D6). Among the 14 compounds, 5-hydroxygraveroline (1), 8-methoxyifflaiamine (2), lunamarine (3), and lunine (12) increased their inhibitory activity with increasing preincubation time. Then, we further examined the possibility of mechanism-based inhibition on 5-hydroxygraveroline (1) and lunamarine (3), which showed the potent inhibition. Further investigations on 1 and 3 showed that the characteristic time- and concentration-dependent inhibition, which required a catalytic step with NADPH, was not protected by nucleophiles, and was decreased by the presence of a competitive inhibitor. Thus, 1 and 3 were concluded as mechanism-based inactivators of CYP2D6.  相似文献   

Accumulation of constitutive diterpenoids in the rhytidome and secondary phloem of the branch bark of Larix gmelinii var. japonica     

Kazuto Seki  Ken Orihashi  Mayumi Sato  Masanori Kishino  Naoto Saito 《Journal of Wood Science》2012,58(5):437-445

The quantitative compositions of the major constitutive diterpenoids in the rhytidome and secondary phloem of the branch bark of Kuril larch (Larix gmelinii var. japonica) were investigated. The eight major diterpenoids were isolated from a diethyl ether extract of the branch bark of L. gmelinii var. japonica and identified as 13-epimanool (1), larixol (2), larixyl acetate (3), 13-epitorulosyl acetate (4), abietic acid (5), neoabietic acid (6), dehydroabietic acid (7), and isopimaric acid (8). The amount of each diterpenoid was subsequently quantified in both the rhytidome and secondary phloem. All of the diterpenoids were present in both bark tissues, but the amounts were significantly higher in the rhytidome than in the secondary phloem. Developed fusiform resin cavities containing oleoresins were commonly observed in dead secondary phloem captured into the rhytidome of a bark transverse section. The accumulation and distribution of these constitutive diterpenoids in the bark tissues can probably be attributed to terpenoid biosynthesis in the living secondary phloem and the rhytidome formation process. From the viewpoint of constitutive chemical defense in conifers, it is suggested that the tree body may be more effectively defended against natural enemies by the higher amount of diterpenoid amount in the outermost and dead bark tissue, the rhytidome, where the potentially poisonous and easily oxidizable diterpenoids can be safely and stably maintained.  相似文献