Cytotoxic constituents in the holdfast of cultivated Laminaria japonica     

Makoto  NISHIZAWA  Nobuaki  TAKAHASHI  Kumiko  SHIMOZAWA  Takako  AOYAMA  Kouichi  JINBOW  Yukari  NOGUCHI  Kiyoshi  HORITA  Hideo  BANDO  Takashi  YAMAGISHI 《Fisheries Science》2003,69(3):639-643

ABSTRACT:     Four steroidal ketones were isolated from the holdfast of cultivated Laminaria japonica . The structures were characterized as ergosta-4,24(28)-diene-3-one (1), ergosta-4,24(28)-diene-3,6-dione (2), stigmasta-4,24(28)-diene-3-one (3) and stigmasta-4,24(28)-diene-3,6-dione (4), by spectral data. Compounds 2 and 4 were shown to be cytotoxic against the MCF-7 human breast cancer cell, and the growth of MCF-7 was inhibited by 96% and 79%, respectively, at 10 µg/mL. It is the first report on the isolation of cytotoxic steroidal ketones from the kelp in the genus of Laminaria.  相似文献   

Improved method for culturing the swimming crab Portunus trituberculatus larvae to prevent mass mortality during seed production     

Shigeki Dan  Masakazu Ashidate  Katsuyuki Hamasaki 《Fisheries Science》2016,82(1):113-126

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The smell and odorous components of dried shiitake mushroom, Lentinula edodes III: substances that increase the odorous compound content     

Masakazu Hiraide 《Journal of Wood Science》2006,52(3):265-269

This study formed part of an effort to improve the quality of dried shiitake mushroom [Lentinula edodes (Berk.) Pegler], in accordance with consumer preferences, and deals with the search for substances that increase the odorous component content. From analysis of sulfur and sulfur-containing substances in the culture substrate, rice bran was found to be the main source of sulfur, and 75% of this was present as cysteine and methionine. The sulfur-containing substances were added to a sawdust medium containing only rice bran and sawdust as a substrate; shiitake mushrooms were cultivated in the medium, the fruiting bodies were dried, and the 1,2,4-trithiolane content in the fruiting bodies was measured as an indicator of the odorous compounds. Of the sulfur-containing substances, those that increased odorous compounds the most were cysteine and methionine. The efficiency of cysteine in this regard was higher than that of methionine. It was also noted that the amount of glutamic acid increased the odorous compounds in combination with cysteine and methionine. Furthermore, the addition of both amino acids and glutamic acid had no negative effect on the yield. These results showed that it is possible to produce dried shiitake mushrooms with a smell suitable for particular consumer preferences.  相似文献   

The impact of forest clear-cutting on soil temperature: a comparison between before and after cutting,and between clear-cut and control sites   总被引：2，自引：0，他引：2  

Shoji?HashimotoEmail author  Masakazu?Suzuki 《Journal of Forest Research》2004,9(2):125-132

Soil temperature is one of the most important factors governing biological activity in the soil. This study was conducted to investigate how forest clear-cutting changes soil temperature. Soil temperatures at 0.5, 1.0, 2.0, and 3.0m depths were measured in two neighboring forest watersheds (35°12N, 140°06E) in Chiba Prefecture, Japan, from 1994 to 2000. One watershed was clear-cut 5 years after the observations began. After clear-cutting, the annual mean soil temperature at 0.5, 1.0, 2.0, and 3.0m depths rose by about 2.2, 2.0, 1.7, and 1.4°C, respectively. The maximum respective soil temperatures rose by about 3.2, 3.0, 2.2, and 1.8°C. The minimum soil temperature rose slightly (1°C). The range of temperatures increased by 3.0, 2.4, 1.6, and 1.4°C, respectively. In our study, forest clear-cutting raised maximum and average soil temperatures but hardly changed minimum soil temperature. This is probably because solar radiation dominated in the summer season and increased soil temperature; on the other hand, net long-wave radiation, and releases of latent and sensible heat from the soil surface, were predominant in the cool season.  相似文献   

The smell and odorous components of dried shiitake mushroom, <Emphasis Type="Italic">Lentinula edodes</Emphasis> I: relationship between sensory evaluations and amounts of odorous components     

Masakazu?HiraideEmail author  Yoshifumi?Miyazaki  Yasushi?Shibata 《Journal of Wood Science》2004,50(4):358-364

The smell of food is one of the most important factors in assessing its quality. Concerning the smell of dried shiitake mushrooms [Lentinula edodes (Berk.) Pegler], 1,2,3,5,6-pentathiepane, commonly known as lenthionine, has been reported as a key compound. However, other compounds have not been studied sufficiently in connection with smell. From the results of sensory intensity studies and sensory evaluations of dried shiitake mushrooms, a positive significant correlation at 1% risk was observed between sensory intensity and sulfur perception. This showed that the smell of dried shiitake mushrooms was characterized by a sulfurous smell. Also, comparing the sensory intensity with the amounts of volatile components showed positive significant correlations at 1% risk between sensory intensity and three compounds: 1,2,4-trithiolane, 1,2,4,6-tetrathiepane, and lenthionine. Furthermore, significant correlations at 5% risk were obtained between the amounts of these three compounds and sensory intensity by multiple regression analysis. This showed that the smell of dried shiitake mushrooms depended on these compounds. The partial regression coefficient of 1,2,4-trithiolane was larger than those of the others, and so it was proposed that 1,2,4-trithiolane could serve as an indicator to estimate the smell of dried shiitake mushroom.  相似文献   

Adsorption of mercury by sugi wood carbonized at 1000°C     

Lilibeth Pulido-Novicio  Yasuji Kurimoto  Masakazu Aoyama  Kazuto Seki  Shuichi Doi  Toshimitsu Hata  Shigehisa Ishihara  Yuji Imamura 《Journal of Wood Science》2001,47(2):159-162

The ability of sugi wood carbonized at 1000°C to adsorb mercury was examined using aqueous solutions of mercuric chloride. Parameters studied include contact time, pH, adsorption temperature, and initial concentration of mercury in solution. Results showed that sugi wood carbonized at 1000°C could effectively remove mercury from aqueous solutions. The carbonized wood showed high adsorption ability for mercury at a wide pH range (pH 3–9), but its ability drastically decreased at pH 11. Adsorption decreased with increases in adsorption temperatures, indicating that the processes were exothermic in nature. Adsorption was found to follow the Freundlich isotherm model. The adsorption capacity of carbonized sugi wood was comparable to that of commercial activated carbon.  相似文献   

Detection and sequence analysis of DNA polymerase and major envelope protein genes in koi herpesviruses derived from Cyprinus carpio in Gunma prefecture, Japan     

Ishioka T  Yoshizumi M  Izumi S  Suzuki K  Suzuki H  Kozawa K  Arai M  Nobusawa K  Morita Y  Kato M  Hoshino T  Iida T  Kosuge K  Kimura H 《Veterinary microbiology》2005,110(1-2):27-33

Koi herpesvirus (KHV), which is believed to be an emerging virus, causes fatal diseases in carps. Since the 1990s, the presence of KHV has been confirmed in several countries. In Japan, from 2003 to 2004, large outbreaks of KHV infection in farmed carps resulted in the death of numerous fishes. From April to May 2004, we collected 43 dead or dying carps exhibiting typical symptoms of KHV infection in Gunma prefecture. To conduct a molecular epidemiologic study of KHV in our prefecture, we amplified DNA polymerase and the major envelope protein genes of KHV derived from carp gills using newly designed primers. We also performed sequence analysis of both genes of KHV. Sensitivity of our PCR method for amplification of DNA polymerase and the major envelope protein genes of KHV was 3 x 10(2) (100 fg) and 3 x 10(3) (1000 fg) copies of KHV genome, respectively. We detected both DNA polymerase and major envelope protein genes in 37 of 43 carps (86%). No mutation was found in both the genes sequenced from 11 strains, which included two foreign strains and one domestic strain. The results suggested that KHV strains derived from carps in our prefecture were closely related genetically to the other KHV strains.  相似文献   

Marine biogeochemical response to a rapid warming in the main stream of the Kuroshio in the western North Pacific     

MICHIO AOYAMA  HIROHITO GOTO  HITOMI KAMIYA  IKUO KANEKO  SATOSHI KAWAE  HIROKI KODAMA  YASUSHI KONISHI  KENN-ICHI KUSUMOTO  HISATO MIURA  EIICHI MORIYAMA  KIYOSHI MURAKAMI  TOSHIYA NAKANO  FUTOSHI NOZAKI  DAISUKE SASANO  TAKAO SHIMIZU  HIROKI SUZUKI  YASUSHI TAKATSUKI  AKITO TORIYAMA 《Fisheries Oceanography》2008,17(3):206-218

Impact of climate change on marine biogeochemical parameters and ecosystem is one of the important issues of our environment. Direct evidence of marine pelagic ecosystem changes is found with warming of sea water and sea‐level rise in the main stream of the Kuroshio in the East China Sea and the western North Pacific during these three decades based on the analysis of long‐term comprehensive hydrographic observations. In terms of annual mean, the warming rate of surface air temperature and sea surface temperature ranged from 0.15 to 0.21°C per decade in and around the main stream of the Kuroshio in the East China Sea, which exceed the global mean warming rate of 0.128 ± 0.026°C per decade during the period from 1956 to 2005 reported in IPCC 2007. One of the features in this rapid warming region is an increase of number of Pterosagitta draco, a cosmopolitan warm‐water zooplankton. Biogeochemical parameters, such as wet weight of zooplankton, plant pigment and nutrients concentration in the upper 200 m have been decreasing while dissolved oxygen content and seawater temperature have been increasing in the upper 200 m in the main stream of the Kuroshio in the East China Sea. These observed linear trends of the biogeochemical parameters would be foresights for temperate oceans in the future.  相似文献   

Number and density of retinal photoreceptor cells with emphasis on oil droplet distribution in the Mallard Duck (Anas platyrhynchos var. domesticus)     

Mohammad Lutfur RAHMAN  Masato AOYAMA  Shoei SUGITA 《Animal Science Journal》2007,78(6):639-649

This study was intended to determine the number and regional distribution of photoreceptor cells and different colored oil droplets in the retina of the Mallard Duck (Anas platyrhynchos var. domesticus). To estimate the number and density of photoreceptor cells, adult ducks were killed and both eyes were enucleated under deep anesthesia to prepare Nissl‐stained retinal whole‐mount samples. Different colored oil droplets were counted from color microphotographs of the freshly prepared retina. The mean number of retinal photoreceptors was approximately 6 308 828 ± 521 927, with a peak density of 33 573/mm² in the central retina. The density was similar in the nasal, temporal, ventral and dorsal areas of the retina. Five types of oil droplets were identified on the basis of color: red, orange, greenish‐yellow, yellow and clear. The mean density of oil droplets was highest in the central retina (17 639/mm²) and gradually declined towards the nasal, temporal, ventral and dorsal areas. The size of oil droplets gradually increased with retinal eccentricity and varied even within an area. The greenish‐yellow oil droplets were most abundant across the retina. Taken together, these results demonstrate the differential retinal distribution of photoreceptor cells and oil droplets in duck retina. We conclude that the area of high photoreceptor cell density, which is matched by high neuron densities of the ganglion cell layer, corresponds to the site of acute vision in duck retina.  相似文献   

Distribution and movement of larvae, juvenile and young of the pointhead flounder Hippoglossoides pinetorum in Ishikari Bay and vicinity, Hokkaido   总被引：1，自引：0，他引：1  

Osamu Tominaga  Masamichi Watanobe  Masakazu Hanyu  Kazuko Domon  Yasuhiro Watanabe and  Toyomi Takahashi 《Fisheries Science》2000,66(3):442-451

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