• Title/Summary/Keyword: Biological half life

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Evaluation of pH-sensitive Eudragit E100 Microcapsules Containing Nisin for Controlling the Ripening of Kimchi

  • Ko, Sung-Ho;Kim, Han-Soo;Jo, Seong-Chun;Cho, Sung-Hwan;Park, Wan-Soo;Lee, Seung-Cheol
    • Food Science and Biotechnology
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    • v.14 no.3
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    • pp.358-362
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    • 2005
  • Eudragit E100 microcapsules containing nisin were prepared and employed to control the ripening of kimchi. The recovery yields of microcapsules without/with nisin ranged from 93.53 to 94.61 % and 92.85 to 94.09 %, respectively. The particle size of microcapsules decreased (>200 to $100\;{\mu}m$) as the amount of aluminium tristearate increased from 6.0 to 15 %. The microcapsules were morphologically spherical and possessed rough surface. Nisin was completely released from the microcapsules within a day at pH 3.0 and within two days at pH 4.0, 5.0, and 6.0, respectively, whereas half the amount of nisin was released at pH 7.0 within two days. During fermentation of kimchi with microcapsules containing nisin, the pH decrease was retarded which resulted in a constant pH of approximately 4.2. The pH of 4.2 was optimal for ripening of kimchi for a longer period of time when compared with samples without nisin.

MULTI-CHANNEL VISION SYSTEM FOR ON-LINE QUANTIFICATION OF APPEARANCE QUALITY FACTORS OF APPLE

  • Lee, S. H.;S. H. Noh
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2000.11c
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    • pp.551-559
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    • 2000
  • An integrated on-line inspection system was constructed with seven cameras, half mirrors to split images, 720 nm and 970 nm band pass filters, illumination chamber having several tungsten-halogen lamps, one main computer, one color frame grabber, two 4-channel multiplexors, and flat plate conveyer, etc., so that a total of seven images, that is, one color image from the top side of an apple and two B/W images from each side (top, right and left) could be captured and displayed on a computer monitor through the multiplexor. One of the two B/W images captured from each side is 720nm filter image and the other is 970nm. With this system an on-line grading software was developed to evaluate appearance quality. On-line test results to the Fuji apples that were manually fed on the conveyer showed that grading accuracies of the color, defective and shape were 95.3%, 86% and 91%, respectively. Grading time was 0.35 sec per apple on an average. Therefore, this on-line grading system could be used for inspection of the final products produced from an apple sorting system.

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Molecular breeding of herbicide resistant transgenic plants with bromoxynil specific nitrilase gene (Bromoxynil 특이성 nitrilase 유전자를 이용한 제초제 저항성 형질 전환 식물의 분자육종)

  • Min, Bok-Kee;Park, Eun-Sung;Park, Yearn-Hung;Song, Jae-Young;Lee, Se-Yong
    • Applied Biological Chemistry
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    • v.37 no.4
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    • pp.248-254
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    • 1994
  • Bromoxynil is an antidicot herbicide widely used on cereal crops and has a short half life in the soil. A bxn gene, encoding a specific nitrilase that converts bromoxynil to its primary metabolite 3,5-dibromo-4-hydroxybenzoic acid, was inserted in plant binary vector pGA482, and then introduced into tobacco and lettuce plants via Agrobacterium mediated leaf-disc transformation method. Transgenic plants with the bxn gene were selected by kanamycin and regenerated to whole plants. The regenerated transgenic plants were determined level of expression of bxn gene by Northern blot analysis. Leaf-disc analysis and pot-assay confirmed that the transgenic tobacco and lettuce plants were resistant to high doses of bromoxynil.

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Degradation and Residue of Fujione and Ortran in Korean Rice Paddy System (수도용 농약후치왕, 오트란의 작물 및 토양에서의 잔류와 분해)

  • Baik, Ok-Ryun;Roh, Jung-Koo;Kim, Taik-Je
    • Applied Biological Chemistry
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    • v.25 no.2
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    • pp.93-98
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    • 1982
  • Residues of Fujione (Fudiolan, fungicide) and Ortran (Acephate, insecticide) in Korean rice crop were studied. Also the persistencies of the pesticides in rice paddy soil were investigated in field and in laboratory. The residual levels of the pesticides in rice plant, straw, unpolished and polished rice were varied with the application rates of the pesticides. The residues of Fujione and Ortran in unpolished rice were $0.07{\sim}0.09ppm$ and $0.01{\sim}0.53ppm$, respectively. The half life of Fujione was 30 days under aerobic and 150 days under flooded condition in the laboratory system. Whereas in the paddy field it was about 100 days. In the case of Ortran it was $3{\sim}4$ days and $13{\sim}14$ days in aerobic and flooded condition, respectively in laboratory system.

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Aqueous Photolysis of the Organophosphorus Insecticide Flupyrazofos (유기인계 살충제 Flupyrazofos의 수중 광분해)

  • Kim, Kyun;Kim, Yong-Hwa;Lee, Jae-Koo;Jeong, Yun-Ju
    • Applied Biological Chemistry
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    • v.43 no.2
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    • pp.130-135
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    • 2000
  • Photodegradation rate of flupyrazofos in aqueous solution were measured under various test conditions mainly following the guidelines of U.S. EPA and OECD. It was observed that the flupyrazofos was degraded by simple hydrolysis but not degraded by light in pure water. Using acetone as a known photosensitizer, the minimal concentration of acetone needed to photo-degrade the flupyrazofos in % and molar terms were 0.047% and 0.006, respectively. When treated with acetone, it was also found that the ringlet oxygen is a very effective photo oxidant in the degradation of flupyrazofos, but the effect of hydroxyl radical was not observed at the treatment level of hydroxyl radical, isopropylbenzene. In an actinometer experiment, quantum yield of flupyrazofos (0.4 ppm with 2% acetone) was $17.66{\times}10^{-5}$ and degradation rate and half-life were 0.038/hr and 18.2 hours, respectively.

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A cold-active acidophilic endoglucanase of Paenibacillus sp. Y2 isolated from soil in an alpine region

  • Lee, Jae Pil;Seo, Gu-Won;An, Shin-Deuk;Kim, Hoon
    • Journal of Applied Biological Chemistry
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    • v.60 no.3
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    • pp.257-263
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    • 2017
  • A cellulolytic strain Y2 was isolated from soil obtained in the Canadian Alpine region. The isolate was identified as Paenibacillus sp. Y2 by 16S rRNA sequencing. When grown in LB medium supplemented with carboxymethyl-cellulose (CMC), CMCase production increased to 122.0% of that observed in LB without CMC. Culture supernatant was concentrated by ultrafiltration and 80% ammonium sulfate precipitates were separated by Hi-Trap Q and CHT-II chromatography. The purified enzyme (EG-PY2) showed a homogeneous single band and the molecular mass was estimated to be 38 kDa by SDS-PAGE. Optimum pH and temperature of the enzyme were 4.5 and $30^{\circ}C$, respectively. The half-life of enzyme activity at 50 was 140.7 min, but the enzyme was drastically inactivated within 5 min at $55^{\circ}C$. The enzyme was highly activated to 135.7 and 126.7% by 5.0 mM of $Cu^{2+}$ or $Mg^{2+}$ ions, respectively, and moderately activated by $Ba^{2+}$ and $Ca^{2+}$ ions, whereas it was inhibited to 76.8% by $Fe^{2+}$, and to ${\leq}50%$ by $Mn^{2+}$, $Co^{2+}$, $Zn^{2+}$, and EDTA. The enzyme was activated to 211.5% in the presence of 0.5 M of NaCl and greatly tolerant to 3.15M of NaCl. The enzyme showed 2.98 times higher ${\beta}$-glucanase activity than CMCase activity. Based on these results, it can be concluded that EG-PY2 is an acidophilic, cold-active, and halotolerant endoglucanase. The authors suggest it is considered to be useful for various industrial applications, such as, fruit juice clarification, acidic deinking processes, high-salt food processing, textile and pulp industries, and for biofuel production from seaweeds.

MODULATION OF TOXICITY AND CARCINOGENESIS BY CALORIC RESTRICTION

  • Allaben, William T.;Chou, Ming W.;Pegram, Rex A.;Leakey, Julian;Feuers, Ritchie J.;Duffy, Peter H.;Turturro, Angelo;Hart, Ronald W.
    • Toxicological Research
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    • v.6 no.2
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    • pp.167-182
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    • 1990
  • Dietary restriction (caloric restriction) is the only intervention which has been reliably shown to extend the maximum life span of warm-blooded animals and delay the many phenomena associated with aging. It is also one of the most effective modulators of toxicity, especially cancer endpoints. In spite of the known modulator effects of caloric restriction, the biological mechanisms responsible for these effects had not been in vestigated until recently. The National Center for Toxicological Research (NCTR), in a collaborative effort with the National Institute of Aging (NIA), initiated a project whereby nine (9) combinations of rodent species/strains and diets were fed both restricted and ad libitum. The NIA's initiative was to identify biomarkers of aging whereas NCTR's initiative was to identify the biological effects associated with the profound effects caloric restriction has in protecting against both spontaneous (age-related) and chemically-induced toxic endpoints. Independent of sex or species, caloric restriction has similar effects on body temperature, oxygen consumption and $CO_2$production. Caloric restriction also decreased lipid glycolysis and metabolism in rats and mice, which suggest decreased production of metabolites which could lead to fatty acid epoxide formation. The age-associated loss of ciradian regulation of intermediate enzymes is also significantly reduced. Moreover, caloric restriction reduced the age-associated feminization of sexually dimorphic liver isozymes, increased several glucocorticoid responsive isozymes, elevated glucagon/insulin ratios, produced less microsomal superoxide and enhanced the capacity for utilzing detoxicating metabolic pathways. Calorically restricted rats have less than half the number of aflatoxin ($AFB_1$)-DNA adducts than ad libitum animals and urinary excretion of $AFB_1$ was increased significantly. Finally, DNA repair mechanisms are enhanced and oncogene expression is decreased in calorically restricted animals.

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Antifungal activity of N-[1-(benzotriazol-1-yl)aryl]arylamine derivatives and quntitative structure-activity relationships(QSAR) (N-[1-(benzotriazol-1-yl)aryl]arylamine 유도체의 항균성과 정량적 구조활성 관계(QSAR))

  • Sung, Nack-Do;Kim, Kyoung-Hoon;Choi, Woo-Young;Kim, Hong-Ki
    • Applied Biological Chemistry
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    • v.35 no.1
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    • pp.14-22
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    • 1992
  • A series of new N-[1-(benzotriazol-1-yl)aryl]arylamine derivatives were synthesized and their antifungal activities $(pI_{50})$ in vitro against Pyricularia oryzae, Fusarium oxysporum f. sp. sesami, Valsa ceratosperma and Botrytis cinerea were dertermined by the agar medium dilution method. From the results of the quantitative structure-activity relationships $(QSAR_S)$ analysis, $hydrophobicity({\pi})$, $electronic({\Sigma\sigma})$ and molar $refractivity({\Sigma}M_R)$ parameter of X & Y-substituents on the phenyl group were also shown to be important factor in determining the variation in the antifungal activity. 4-Bromo group substituents (1d & 2b) were the most effective compounds and the $half-life(T_{1/2})$ on the hydrolysis of X(1) at netural pH was about 1.5 day. Molecular orbital(MO) functions of substrate compound, linear free energy relationships$(LFER_S)$ on the antifungal reactivity arid the results of molecular design were also discussed.

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Persistence and Dislodgeable Residues of Chlorpyrifos and Procymidone in Lettuce Leaves under Greenhouse Condition (상추의 생산단계별 Chlorpyrifos 및 Procymidone의 잔류허용기준 설정)

  • Kim, Young-Sook;Park, Ju-Hwang;Park, Jong-Woo;Lee, Young-Deuk;Lee, Kyu-Seung;Kim, Jang-Eok
    • Korean Journal of Environmental Agriculture
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    • v.21 no.2
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    • pp.149-155
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    • 2002
  • Two pesticides commonly used for lettuce cultivation including chlorpyrifos and procymidone were subjected to a field residue trial to ensure safety of terminal residues in the harvest. After pesticides were applied at standard and double rates in a foliar spray, leaf persistence of their residues was investigated far 10 days prior to harvest. Even though far exceeded the tolerances, initial leaf residues were rapidly dissipated with time and remained only 0.4$\sim$7.2% of the residues in the harvest. As well fitted by the first-order kinetics, biological half-lives of the pesticide residues in lettuce leaves ranged 1.2$\sim$2.6 days. Slow dissipation of the residues in the harvest was observed during storage at room temperature and 4$^{\circ}C$ for 7 days. Portions of dislodgeable residues which resided in detergent washings decreased as time elapsed. Patterns in dissipation and distribution of dislodgeable residues were not largely affected by the application rate of pesticides. It is concluded that timing of pesticide application, that is, pre-harvest interval would be the first factor to determine the terminal residue level in edible portions of lettuce.

The Application of Genome Research to Development of Aquaculture (양식산업에 발전을 위한 유전체 분석 기술 적용)

  • Lee, Seung Jae;Kim, Jinmu;Choi, Eunkyung;Jo, Euna;Cho, Minjoo;Park, Hyun
    • Journal of Marine Life Science
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    • v.6 no.2
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    • pp.47-57
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    • 2021
  • In the fishery industry, global aquaculture production has stagnated due to overfishing of aquatic products, restrictions between countries, and climate change. The aquaculture suggests the possibility of a blue revolution that can be expanded in a new way. The aquaculture industry now accounts for more than half of the fishery products from the sea as a raw material for seafood for human consumption. Various latest biological research methods are being applied for the development of a sustainable aquaculture industry. Genomics has made significant progress in recent years. Since the genome sequence of Atlantic cod was sequenced in 2011, the genomes of more species have been sequenced. The genome information is providing a more robust and productive knowledge base for the aquaculture industry, including breeding and breeding of superior traits, improving disease resistance quality, and optimizing aquaculture feed and feed methods. This review looked at the status of genome analysis technology and the current status of genome research of aquaculture species. The development of genome research technology and massive genomic information is important in solving the challenges of the aquaculture industry and will help sustainable fisheries and aquaculture.