Simultaneous liquid chromatographic determination of residual synthetic antibacterials in cultured fish     

N Nose  Y Hoshino  Y Kikuchi  M Horie  K Saitoh  T Kawachi  H Nakazawa 《Journal of the Association of Official Analytical Chemists》1987,70(4):714-717

A liquid chromatographic method is described to determine simultaneously the following 11 synthetic antibacterial agents used in a fishery: nitrofuran derivatives furazolidone, nifurpirinol, difurazone, and furamizole; sulfa drugs sulfamerazine, sulfisozole, sulfamonomethoxine, and sulfadimethoxine; and, oxolinic, nalidixic, and piromidic acids. A Nucleosil C18 column was used with tetrahydrofuran-acetonitrile-phosphoric acid-water (29 + 1 + 0.06 + 69.94) as the mobile phase. Pretreatment of the fish meat sample with acetone extraction and alumina column cleanup gave good separation of the LC peaks without interference from any other components. Recovery of the antibacterial agents was ca 80%. The lower limit of detection of the drugs was 1-2 ng for 10 microL injection.  相似文献   

Inhibitory activity of corn-derived bisamide compounds against alpha-glucosidase     

Niwa T  Doi U  Osawa T 《Journal of agricultural and food chemistry》2003,51(1):90-94

Bioassay guided fractionation from corn gluten meal, a byproduct of a starch manufacturing plant, gave N-p-coumaroyl-N'-feruloylputrescine (1) and N,N'-diferuloylputrescine (2) as alpha-glucosidase inhibitors. Some structure-activity relationships were studied by comparing the inhibitory activity by preparing some related compounds, and it was revealed that the hydroxyl group was important for the inhibitory activity of bisamide alkaloids, but not the redox potential.  相似文献   

Procyanidin trimers to pentamers fractionated from apple inhibit melanogenesis in B16 mouse melanoma cells     

Shoji T  Masumoto S  Moriichi N  Kobori M  Kanda T  Shinmoto H  Tsushida T 《Journal of agricultural and food chemistry》2005,53(15):6105-6111

The effects of apple polyphenols on melanogenesis in B16 mouse melanoma cells were investigated. The inhibitory effect of apple polyphenols was stronger than that of arbutin or kojic acid. Three polyphenol fractions (phenolic acid derivatives, procyanidins and other flavonoids) were isolated, and the procyanidins were fractionated according to the degree of polymerization using normal-phase chromatography. The procyanidin trimer-to-pentamer fractions were found to have the most pronounced effect on melanogenesis. Furthermore, each procyanidin fraction inhibited mushroom tyrosinase. No correlation between the degree of procyanidin polymerization and tyrosinase inhibitory activity was observed. Nevertheless, these observations suggest that procyanidins are effective inhibitors of tyrosinase.  相似文献   

Mixed Type of Malignant Mesothelioma in an Aged Male ICR Mouse     

Shirai M  Maejima T  Tanimoto T  Kumagai K  Makino T  Kai K  Teranishi M  Sanbuissho A 《Journal of toxicologic pathology》2011,24(3):169-172

Multiple whitish nodules in the thoracic cavity at the site of the thymus were observed in a 101-week-old male ICR mouse. In a histopathological examination, the neoplastic cells were predominantly fusiform in shape and proliferated in sarcomatoid growth patterns. Some neoplastic cells showed epithelial growth patterns, such as the ductal structures. Mitotic figures were frequently seen, and small necrotic foci and invasion to adjacent thoracic organs were noted. In Alcian blue staining, bluish materials were observed between fusiform-shaped cells and in some of the lumens of the ductal structures. In immunohistochemistry, both fusiform-shaped and ductal structure-forming cells were positive for vimentin and weakly positive to positive for cytokeratin. Based on the aforementioned findings, the thoracic nodules were diagnosed as a mixed type of malignant mesothelioma. This case was thought to be rare because of the very low occurrence of spontaneous mesothelioma in mice.  相似文献   

Effects of anion channel blockers on xylem nitrate transport in barley seedlings     

Tahei Kawachi  Chizuru Nishijo  Hiroyuki Fujikake  Salwa Abdel-Latif  Norikuni Ohtake  Kuni Sueyoshi 《Soil Science and Plant Nutrition》2013,59(2):271-277

Abstract

Taxonomic characteristics in accumulating Co and Ni was investigated with 60 plant species (37 genera, 27 families) grown on granite derived soils containing slightly low level of available Co. Considerable variations in Co and Ni content were observed among plant !species with small differences with regard to sampling sites. Exceptionally high Co content (25 ppm on D.W. basis) was found in the leaves of Clethra barbinervis. The value was about 48 times higher than the lowest Co content species. Reasonably high Co content was found with some species in genera: Hydrangea and Viburunum. Ni was highly accumulated in the leaves of Sasa borealis (16 ppm) and in fruits of Clethra barbinervis (65 ppm). [Other Nirich species were especially found in genera: Struthiopteris, Hydrangea, Stewartia, Clethra, and Symplocos. High positive correlation (P<0.01) was found between the concentration of Co and Ni in plant species.  相似文献   

A DGGE analysis shows that crop rotation systems influence the bacterial and fungal communities in soils     

Chika Suzuki  Norikuni Oka  Kazunari Nagaoka  Toshihiko Karasawa 《Soil Science and Plant Nutrition》2013,59(3):288-296

A better understanding of the relationships among different cropping systems, their effects on soil microbial ecology, and their effects on crop health and productivity is necessary for the development of more efficient, sustainable crop production systems. We used denaturing gradient gel electrophoresis (DGGE) to determine the impacts of crop rotations and crop types on bacterial and fungal communities in the soil. The communities of bacterial 16S rRNA genes and fungal 18S rRNA genes were analyzed in experimental field plots that were kept under 4 different crop rotation systems from 1999 to 2008 (continuous cabbage (Brassica oleracea var. capitata L.), cabbage–lettuce (Lactuca sativa L.) rotation, cabbage–radish (Raphanus sativus L. var. longipinnatus L.H. Bailey) rotation, and a 3-year crop rotation). A principal component analysis (PCA) and a canonical correspondence analysis (CCA) revealed that both the bacterial and fungal communities in bulk soils were influenced by the crop rotation systems. However, the primary factors influencing each community differed: bacterial communities were most affected by soil properties (especially carbon content), while fungal communities were influenced most strongly by rotation times. To elucidate factors that may cause differences in crop rhizosphere microbial communities, the microbial communities in the harvested cabbage rhizospheres were also analyzed. The results suggest that the fungal communities in bulk soil are related to the rhizosphere fungal communities. Our present study indicates that the microbial communities in bulk and rhizosphere soils could be managed by crop rotation systems.  相似文献   

Cesium-137 concentration of forage corn and Italian ryegrass in a double cropping system under different rates of cattle farmyard manure application after the Fukushima Daiichi Nuclear Power Station accident in 2011     

Hisatomi Harada  Yoshihito Sunaga  Tahei Kawachi 《Soil Science and Plant Nutrition》2013,59(6):972-982

Abstract

Radioactive ¹³⁷Cs concentrations of forage corn (Zea mays L.) and Italian ryegrass (Lolium multiflorum Lam.) in a double cropping system under continuous cattle farmyard manure (FYM) application were observed for more than 2 years after the Fukushima Daiichi Nuclear Power Station accident in 2011. The experiment field is located 110 km southwest of the Fukushima Daiichi Nuclear Power Station, and the soil contains ¹³⁷Cs of 920 Bq kg^?1 on average. For crop cultivation, nitrogen fertilizer was applied in addition to FYM. The ¹³⁷Cs concentrations in corn decreased significantly between 2011 and 2012, but only differed significantly between 2012 and 2013 for the plot with no FYM application. For Italian ryegrass, no significant differences were observed between the harvest in 2012 and 2013 despite the FYM application rate. To minimize corn ¹³⁷Cs concentrations, the FYM application rate should be more than and equal to 30 Mg ha^?1 when FYM is used as the major nutrient source. Exchangeable potassium oxide (K₂O) greater than around 0.3 g kg^?1 was mostly maintained with the FYM application rates. Corn ¹³⁷Cs concentration appeared to increase at exchangeable K₂O levels below 0.15 g kg^?1. These results suggest that continuous FYM application can maintain soil nutrients including K₂O and thereby control radioactive Cs transfer from the soil. FYM application rate of 30 Mg ha^?1 is within the levels recommended by the prefectural governments around Fukushima Prefecture for crop production before the accident. These levels are sufficient to decrease the radioactive Cs concentrations for corn. However, unlike corn, differences in soil chemical properties by FYM application did not affect ¹³⁷Cs concentrations in Italian ryegrass in this study, although low exchangeable K₂O seemed to increase concentrations of stable ¹³³Cs. Further experiments should be conducted to understand the observed differences between corn and Italian ryegrass.  相似文献   

Stochastic multiobjective optimization model for allocating irrigation water to paddy fields     

Qin Zhang  Shigeya Maeda  Toshihiko Kawachi 《Paddy and Water Environment》2007,5(2):93-99

  相似文献   

Application of shallow water equations to analyze runoff processes in hilly farmlands     

Kei Ishida  Macarius Yangyuoru  Koichi Unami  Toshihiko Kawachi 《Paddy and Water Environment》2011,9(4):393-401

Analysis of runoff processes in farmlands during storm events in particular is an important engineering topic. The shallow water equations describing the physical conservation laws are attractive tools for understanding motion of surface water. A numerical model is developed to reproduce surface water flows during storm events, using the finite element method and the finite volume method applied to the one-dimensional shallow water equations. The numerical model has the advantage of dealing with transcritical flows, wet, and dry processes, irregular channel bed slopes, and channel junctions involving multiply connected networks. Standard numerical tests demonstrated some of these features. Runoff processes from farmlands in a Japanese hilly area is analyzed with the numerical model coupled with another runoff model of black-box type. Parameters of the models are calibrated and validated using observed series of rainfall and runoff discharge data. Simulated results included submergence of hydraulic jumps and flood storage in farming plots, which are very informative in terms of assessing diverse functions of the farmlands.  相似文献   

Optimization model for cropping-plan placement in paddy fields considering agricultural profit and nitrogen load management in Japan     

Shunsuke Chono  Shigeya Maeda  Toshihiko Kawachi  Chie Imagawa  Natsuki Buma  Junichiro Takeuchi 《Paddy and Water Environment》2012,10(2):113-120

An optimization model for cropping-plan placement on field plots is presented for supporting decision-making on agricultural management by a farming organization. The mixed 0?C1 programming technique is employed to select the next planting crop at each field plot in a holistic manner. Reduction of total nitrogen discharged from field plots to the downstream end of the drainage canals is expressed as an objective function of the model to balance an achievement of economic goal and environmental conservation. Some Japanese governmental policies on regulating rice cropping areas and on promoting production of particular upland field crops can be formulated in the model. A computational example of cropping-plan placement on field plots managed under integrated policies is given by operating the optimization model with various weights associated with the objectives. The procured trade-off curve and corresponding patterns of cropping-plan could be useful in the decision-making by the farming organization.  相似文献