• Title/Summary/Keyword: Bioassays

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The Comparison of Two Strains of Fibrocapsa japonica (Raphidophyceae) in New Zealand and Japan

  • Cho Eun Seob;Rhodes Lesley L.;Kim Hak Gyoon
    • Fisheries and Aquatic Sciences
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    • v.2 no.1
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    • pp.58-65
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    • 1999
  • Fibrocapsa japonica (Raphidophyceae) is regarded as a harmful algal bloom organism in Japanese waters, where it has been linked to fish kills. Fibrocapsa is a common species in New Zealand coastal waters, particularly in the Hauraki Gulf, where it has regularly bloomed in the spring under E1 Nino climate conditions for the past six years. The New Zealand isolate had 1.4 times more total polyunsaturated acids than the Japanese isolate under the same growth conditions, suggesting that eicosapentaenoic acid in particular coold be used as a discriminating chemotaxonomic marker. The molecular probes tested showed no differential binding of the raphidophytes to lectins, but oligonucleotide probes targeted F. japonica ribosomal RNA bound specifically to both isolates. Neither strain was toxic in mouse or neuroblastoma bioassays. There is no evidence that the New Zealand F. japonica isolates investigated to date produce ichthyotoxins.

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Effect of Pichia anomala SKM-T and Galactomyces geotrichum SJM-59 Dipping on Storage Property and Sensory Quality of Strawberry

  • Mo, Eun-Kyoung;Sung, Chang-Keun
    • Food Science and Biotechnology
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    • v.14 no.4
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    • pp.487-492
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    • 2005
  • Simple competition plate bioassays of Pichia anomala SKM-T and Galactomyces geotrichum SJM-59 were conducted to evaluate their potential as biological control agents that inhibit growth of Botrytis cinerea during post-harvest storage of strawberries (Fragaria ${\times}$ ananassa Duche, Red-Pearl). Occurrence rates of fungi on the surface of yeast-treated strawberries were evaluated during storage at $4^{\circ}C$. P. anomala SKM-T and G. geotrichum SJM-59 showed antifungal activities on agar plate, and P. anomala SKM-T maintained its desirable antifungal activity on surface of strawberries and its physicochemical properties during storage. Sensory evaluation was based on kinesthetics and consumer acceptability. Due to its potential antifungal activity, P. anomala SKM-T could function as biological control agent against spoilage fungi during post-harvest storage of strawberries.

Design, Synthesis and Antifungal Activities of Novel Strobilurin Derivatives Containing Pyrimidine Moieties

  • Zhang, Xiang;Gao, Yong-Xin;Liu, Hui-Jun;Guo, Bao-Yuan;Wang, Hui-Li
    • Bulletin of the Korean Chemical Society
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    • v.33 no.8
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    • pp.2627-2634
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    • 2012
  • Strobilurins are one of the most important classes of agricultural fungicides. To discover new strobilurin derivatives with high activity against resistant pathogens, a series of novel ${\beta}$-methoxyacrylate analogues were designed and synthesized by integrating substituted pyrimidine with a strobilurin pharmacophore. The compounds were confirmed and characterized by infrared, $^1H$ nuclear magnetic resonance, elemental analysis and mass spectroscopy. The bioassays indicated that most of the compounds (1a-1h) exhibited potent antifungal activities against Colletotrichum orbiculare, Botrytis cinerea Pers and Phytophthora capsici Leonian at the concentration of 50 ${\mu}g/mL$. Exhilaratingly, compound 1d (R=3-trifluoromethylphenyl) showed better antifungal activity against all the tested fungi than the commercial strobilurin fungicide azoxystrobin.

Bioassays of Plant Hormones and Plant Growth Regulating Substances II. Abscisic Acid and Brassinolide (식물홀몬 및 생장조절물질의 생물검정기술 II. Abscisic Acid 및 Brassinolide)

  • 최충돈
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.34 no.s01
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    • pp.16-25
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    • 1989
  • A bioassay is a test system using a living organism (in whole or in part) to determine the presence or relative potency of chemical substances. The development and uses of bioassay are intimately linked to the discovery and characterization of the major classes of plant hormones. An application of this relationship is helpful for understanding the concept of plant hormones as well as the use of bioassay. And plant bioassay have been development and employed not only for the discovery and characterization of the biological activity of plant growth regulators but also have served several important secondary roles. The ideal bioassay should possess the characteristic of high specificity. great sensitivity. short response time, low cost and ease of obtaining plant material. acceptable ease of manipulation, and minimal space and equipment requirements.

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Effects of Sodium Cyanide (NaCN) on the Endogenous Rhythm of the Oxygen Consumption Rate in the Black Rockfish Sebastes schlegeli

  • Kim, Wan-Soo;Kim, Jong-Wook;Lee, Jae-Hak;Huh, Sung-Hoe
    • Ocean Science Journal
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    • v.43 no.2
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    • pp.107-113
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    • 2008
  • Laboratory bioassays were conducted to test the acute toxicity effects of sudden exposure to sodium cyanide (NaCN) on the endogenous rhythm of the oxygen consumption rate (OCR) in the black rockfish Sebastes schlegeli. The OCR of the black rockfish(n = 14, total length = $20.4{\pm}1.16\;cm$, wet weight = $158{\pm}25\;g$) was measured with an automatic intermittent-flow-respirometer. OCR decreased significantly when experimental fish were exposed to NaCN. When exposed to 10 ppb NaCN, fish were able to recover their OCR rhythmic activities. When fish were exposed to 20 ppb, however, the metabolic activity rhythms were not recovered. These results suggest that exposure to NaCN concentrations over 20 ppb cause severe physiological damage to the endogenous rhythms of black rockfish.

New Synthetic Approach to Squarylium Near Infrared Dyes

  • Park, Soo-Youl;Oh, Sea-Wha
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2003.04a
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    • pp.29-31
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    • 2003
  • The 1,3-bis(4-aminoaryl)squaraines showed colour change behaviour, they were found to undergo reduction with sodium borohydride in solution to give colourless leuco compounds, which oxidised readily in air back to the coloured squaraine dye. We have shown that oxidation of the parent leuco-squaraines gives the neutral squaraine system. Initial observations indicated that the derivatives gave new long-wavelength absorbing chromophores, and It is interesting to note that the onidation of the leuco squaraines did initially produce a species absorbing at longer wavelengths than the parent squaraine dye. This colour-change redox behaviour has potential in the area of peroxidase-based bioassays and artificial camouflage.

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Effect of the Constituents of Angelicae gigantis Radix on Hepatic Drug Metabolizing Enzymes (참당귀근 성분이 간의 약물대사효소에 미치는 효과)

  • Han, Jung-Mee;Lee, Ihn-Ran;Shin, Kuk-Hyun
    • Korean Journal of Pharmacognosy
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    • v.27 no.4
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    • pp.323-327
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    • 1996
  • The ether soluble fraction of the roots of Angelicae gigantis Radix caused a significant prolongation of hexobarbital(HB) induced sleeping time in mice. Through systematic fractionation of the ether fraction monitored by bioassays, two pyranocoumarins, decursinol angelate and decursin were isolated as active principles. Decursin, as a main component, exhibited significant prolongation of HB-induced hypnosis as well as significant inhibition of hepatic microsomal drug metabolizing enzyme(DME) activities at relatively high dose which indicated that it is a weak DME inhibitor.

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Mutagenic and Clastogenic Activities of the Browning Reaction Model Systems

  • Ryu, Beung-Ho;Kim, Dong-Seuk;Kim, Dong-Su;Lee, Chong-Choil
    • Journal of Food Hygiene and Safety
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    • v.1 no.1
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    • pp.13-21
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    • 1986
  • Two short-term bioassays were employed to asses the mutagenic and clastogenic activities in browning reaction of pentose-creatine, pentose-glycine and pentose-creatine-glycine browning reaction model system. Methylene chloride extract of rhamnose-creatine-glycine browning reaction exhibited the strongest mutagenicity toward Salmonella typhimurium TA98 with S-9. Methylene chloride extract of pentose-creatine and pentose-glycine browning reaction solutions was also tested for mutagenicity, with positive responses. Methylene chloride extract of pentose-creatine-glycine browning reaction solutions induced significant increase in chromosome aberrations in the treated Chinese hamster ovary(CHO) cells. Each of pentose-creatine and pentose-glycine browning reaction solutions induced a relatively low frequency of chromosome aberrations in the treated cells.

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Synthesis and Characterization of Pentarylene Bisimide Derivative as NIR Colorant (NIR Colorant용 Pentarylene Bisimide의 합성 및 특성 연구)

  • Baek, Kwan;Jeong, Yeon-Tae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.2
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    • pp.140-146
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    • 2012
  • A variety of dyes are commercially available today, there is an ongoing need for new chromophoric systems and low-band-gap materials. For example, near-infrared (NIR) emission has received increased attention for applications in bioassays and medicine while NIR absorption is demanded for laser-welding of plastics or efficient blocking of heat rays. Most of the commercially available NIR materials are not suitable for such purposes owing to their insufficient stability. We have developed a novel NIR-absorbing polyaromatic dye. By extending the system of perylenebis(dicarboximide)s along the molecular long axis, we have obtained the higher homologue pentarylenebis(dicarboximide). We have tried to introduce imide functional group to pentarylene in order to increase chemical and thermal stability.

Wicaltin, a New Protein Toxin Secreted by the Yeast Williopsis californica and Its Broad-Spectrum Antimycotic Potential

  • Theisen, Simone;Molkenau, Elisabeth;Schmitt, Manfred J.
    • Journal of Microbiology and Biotechnology
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    • v.10 no.4
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    • pp.547-550
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    • 2000
  • The yeast Williopsis californica was shown to secrete a unique broad-spectrum killer toxin (Wicaltin) with antifungal activity against 14 yeast genera, including yeast-like and mycelial forms of the human pathogens Candida albicans and Sporothrix schenkii. Agar diffusion bioassays indicated that its activity was more pronounced than the antifungal potential of frequently used antimycotics; 0.07 pmol Wicaltin showed the same toxicity as 0.2 pmol miconazole and 29 pmol clotrimazole. Since the toxin's primary target would appear to be the yeast cell wall, Wicaltin may be attractive in combatting clinically relevant yeast and fungal infections.

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