Determination of theaflavins including methylated theaflavins in black tea leaves by solid-phase extraction and HPLC analysis     

Nishimura M  Ishiyama K  Watanabe A  Kawano S  Miyase T  Sano M 《Journal of agricultural and food chemistry》2007,55(18):7252-7257

A quantitative method for four theaflavins and two methylated theaflavin derivatives in black tea leaves was developed by solid-phase extraction and a high-performance liquid chromatographic method with photodiode array detection. The theaflavins in black tea leaves were extracted three times with 40 vol 50% aqueous ethanol (mg dry tea powder/mL) containing 2% ascorbic acid. The ethanol extracts were diluted 4-fold with distilled water. All diluted extracts were directly applied to the solid-phase C18 cartridge column without concentration. The fraction of theaflavins was obtained by 40% ethanol extraction after rinsing with water followed with 15% ethanol extraction. An aliquot of theaflavins after concentration was injected onto an ODS C18 reversed-phase column, and four theaflavins and two methylated theaflavins were sufficiently separated by a linear gradient system using distilled water and acetonitrile with 0.5% acetic acid. This analytical method is sensitive for the determination of a small amount of methylated theaflavins, since various interfering substances produced during the fermentation process were eliminated in advance by solid-phase extraction. Using this analytical method, we also demonstrated that methylated theaflavins were easily produced during the manufacture of black tea.  相似文献   

A note on the occurrence of the vampire squid Vampyroteuthis infernalis Chun off the Pacific coast of Japan, including the first capture off Hokkaido     

John R. Bower  Tsunemi Kubodera  Dhugal J. Lindsay  Naonobu Shiga  Saya Shimura  Fumikazu Sano  Naoto Horii  Tamio Kamiya  Mio Tateyama 《Fisheries Science》2006,72(2):446-448

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Biochemistry and physiology of a family of eel natriuretic peptides   总被引：1，自引：0，他引：1  

Yoshio Takei  Richard J. Balment 《Fish physiology and biochemistry》1993,11(1-6):183-188

Three natriuretic peptides with similar structures were isolated from eels and their amino acid sequences determined; atrial natriuretic peptide (ANP) from atria, ventricular natriuretic peptide (VNP) from ventricles, and C-type natriuretic peptide (CNP) from brains. All three hormones were circulating in eel blood, and their plasma levels invariably decreased when eels were transferred from fresh water (FW) to seawater (SW). Eel ANP and VNP inhibited drinking in FW and SW eels. Eel ANP inhibited water and Na⁺ absorption by the intestine of SW eels. The potency of these ANP effects was 2–3 orders greater than those of other hormones which are known to have similar effects. Eel ANP and VNP induced antidiuresis but not antinatriuresis in FW eels. Eel ANP increased plasma cortisol level in SW eels but not in FW eels. The antidiuretic effect and the stimulation of cortisol secretion in eels are opposite to the ANP effects reported in mammals. These data suggest that ANP plays a complex role in the eel osmoregulation.

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Résumé Trois peptides natriurétiques présentant des structures similaires ont été isolés chez l'anguille et leurs séquences en acides aminés a été déterminées; le peptide atrial natriurétique (ANP) dans l'atria, le peptide ventriculaire natriurétique (VNP) dans les ventricules et le peptide natriurétique de type C dans le cerveau. Ces trois hormones sont présents dans le sang d'anguille et leur niveau plasmatique decroit invariablement quand les anguilles sont transférées d'eau douce en eau de mer. L'ANP et le VNP d'anguille inhibent l'action de boire chez les anguilles d'eau douce et d'eau de mer. L'ANP d'anguille inhibe l'absorption d'eau et de Na⁺ par l'intestin d'anguille en eau de mer. Ces effets de l'ANP sont 2 à 3 fois plus grands que ceux observés avec d'autres hormones qui sont connues pour avoir des effets similaires. L'ANP et le VNP d'anguille induisent l'antidiurèse mais pas l'antinatriurèse chez les anguilles d'eau douce. L'ANP d'anguille augmente chez ce poisson les niveaux de cortisol plasmatique en eau de mer mais pas en eau douce. L'effet antidiurétique et la stimulation de la sécrétion de cortisol chez l'anguille sont contraire aux effets de l'ANP observés chez les mammifères. Ces résultats suggèrent que l'ANP joue un role complexe dans l'osmorégulation de l'anguille.

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Emeritus Professor Dr Syuzo Egusa     

Tokuo  Sano 《Journal of fish diseases》1987,10(5):333-334

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All-male Tilapia Hybrids of Two Strains of Oreochromis niloticus     

Nilton G.  Marengoni Yoshio  Onoue Tetsuo  Oyama 《Journal of the World Aquaculture Society》1998,29(1):108-113

Hybridization between Nile tilapia Oreochromis niloticus (Local and Stirling University strains) and blue tilapia O. aureus was found to be a tool to produce monosex populations. In order to select a purebred that produces all- or nearly all-male hybrids with high productivity, O. niloticus females and their diploid gynogenetics (meiogynes and mitogynes) were hybridized with O. aureus males. The sex ratio of progenies was evaluated from inter- and intraspecific crosses of two strains of Nile tilapia. Single-pair matings and group spawns under hatchery conditions showed no deviation ( P > 0.01) from the expected sex ratio of intraspecific crosses among two strains of Nile tilapia. However, a higher proportion of male progenies in blue tilapia was observed in group spawns in pond ( P < 0.004) and hatchery conditions ( P < 0.01). Only the Stirling strain and mitogynes produced all-male progenies under laboratory conditions. There were significant differences ( P < 0.05) in growth among hybrid progeny groups, when gynogens and their regular O. niloticus (Local strain) females were crossed with O. aureus males. Six-month hybrid offspring from mitogyne female parents grew better than those from regular and meiogyne female broods.  相似文献   

Characteristics of virus-like growth suppression agents against phytoplankton obtained from seawater at the mouth of Funka Bay, Hokkaido, Japan     

Masashi Onji  Tomoo Sawabe and  Yoshio Ezura 《Fisheries Science》2000,66(1):38-43

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Resuscitation of Tenacibaculum sp., the causative bacterium of spotting disease of sea urchin Strongylocentroutus intermedius, from the viable but non-culturable state     

Yuuki  MASUDA  Kenichi  TAJIMA  Yoshio  EZURA 《Fisheries Science》2004,70(2):277-284

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Analysis of Land use and Land Cover Changes in the Coastal Area of Bangladesh using Landsat Imagery     

M. Rafiqul Islam  M. Giashuddin Miah  Yoshio Inoue 《Land Degradation \u0026amp; Development》2016,27(4):899-909

Coastal land use across the globe has experienced remarkable rapid change over the recent decades because of extraordinary anthropogenic pressure and climate variability and change. Therefore, quantitative information about coastal land use change is imperative for effective management and planning resources for sustainable development. We analysed the quantitative land use and land cover changes during 1989–2000–2010 periods in three important agroecological zones of the most vulnerable coastal region of Bangladesh using Landsat images (Thematic Mapper/Enhanced Thematic Mapper Plus). In the Ganges Tidal Floodplain, the area under shrimp cultivation greatly increased at the rate of 2·05% per annum. The majority of the shrimp area gained from conversion of single cropland. In the Meghna Estuarine Floodplain, decreased mudflat and water bodies were observed, which was predominantly converted into cropland. In Chittagong Coastal Plain, salt pan–shrimp area increased with the expense of single and/or double cropland. In all the study areas, settlement area considerably increased over time. The dynamics of land use change have been attributed to low and unstable food production in the coastal region. The approach adopted in study and the results obtained from the study would likely be useful for policy making and identifying direction for future studies on the coastal land use in Bangladesh. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Phyllochron Dynamics Under Controlled Environments in Rice (Oryza Sativa L.)     

Youki Itoh  Yoshio Sano 《Euphytica》2006,150(1-2):87-95

Previously, we reported that phyllochron of rice greatly fluctuated in the course of development under natural conditions. The present study was carried out to examine the phyllochron dynamics using the five near-isogenic lines (NILs) for heading time and the recurrent parent. The change of phyllochron was investigated under four different controlled conditions regarding daylength and temperature. Growth duration (days to heading) showed a large variation among different growth regimes as well as genotypes. Changes of phyllochron were evaluated in the genotypes by using a quartic polynomial regression that was well fitted to the change of phyllochron in the present controlled environments as previously observed under natural conditions. Phyllochron began to drastically increase after around the 5th phytomer order and decreased with the progress of reproductive development in similar manners under different environments. The pattern of phyllochron change varied from a flat to non-flat shape. The shape of the equation was affected by genotypes as well as daylengths and temperatures. In addition, the shape was closely related to the growth duration (days to heading) of the genotype, suggesting that the phyllochron might internally increase depending on the genotype controlling the heading date. Therefore, the present results showed that the sufficient examination of phyllochron dynamics is necessary for understanding a variation in the heading date of rice.  相似文献   

Theoretical studies on the methodological procedures of radiation breeding     

Yoshio Yoshida 《Euphytica》1964,13(1):65-74

If the expectation of the number of desirable mutants for equal size of X ₂-populations decreases with decreasing number of plants per X ₂-line, the one-plant-one-grain method (method C), the one-plant-two-grain method (method D), and the one-plant-three-grain method (method E), especially method C, would be disadvantageous in comparison with the improved ear-to-row method (method B) and the conventional ear-to-row method (method A).From theoretical considerations it can be shown that a probability of occurrence of an X ₂-line containing desirable mutant (p ₁) and a conditional probability of occurrence of such desirable mutant for each one of the plants in such an X ₂-line (p ₂) are not affected by the number of X ₂-lines (m), but by the number of plants per X ₂-line (n). Consequently, the expectation of the number of desirable mutants in an X ₂-population, E(I), can be given by E(I) = mp ₁(1– q ₂ n · n p ₂/(1 –q ₂ n) = mn p ₁ p ₂ where p ₁+q ₁=1 and p ₂+q ₂=1.Therefore, with respect to E(I), method A=B=C=D=E for equal size of X ₂-populations. However, method ABE>D>C for different sizes of X ₂-populations.Most of this work was carried out in the National Institute of Agricultural Sciences, Hiratsuka, Japan.  相似文献