• Title/Summary/Keyword: Half-lives

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Dissipation of Fenitrothion, IBP, and Butachlor in Flooded Soil Under Outdoor Conditions (실외조건(室外條件)의 담수토양중(湛水土壤中) fenitrothion, IBP, butachlor의 소실(消失))

  • Moon, Young-Hee;Ryang, Hwan-Seong
    • Korean Journal of Environmental Agriculture
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    • v.9 no.1
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    • pp.9-13
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    • 1990
  • The dissipation of insecticide fenitrothion(O,O-dimethyl O-4-nitro-m-tolyl phosphorothioate), fungicide IBP(S-benzyl O, O-diisopropyl phosphorothioate), and herbicide butachlor(N-butozymethyl-2-chloro-2', 6'-diethylacetanilide) in flooded soil planted with rice plants was investigated in outdoor pot conditions. The half lives of IBP, butachlor and fenitrothion in the flooding water treated with IBP at 98g, butachlor at 352.8g, and fenitrothion at 100g ai/10a, were 3.6, 1.7 and within 1 day, respectively. The concentration of fenitrothion at 5 days after application was found to be less than 0.0lppm. In the case of IBP and butachlor after 20 days, the concentration was 0.025 and 0.004ppm, respectively. The concentration of fenitrothion, IBP, butachlor in a soil depth of 0-3cm was 0.07, 1.45 and 3.37ppm on the 3rd day after application, and below 0.05, 0.18, 0.39ppm after 7 days, respectively. However, 27 days after application concentration of IBP and butachlor at 0-5cm soil depth resulted in 0.04 and 0.05ppm, respectively. The disappearance of pesticides was remarkably rapid, compared to those in the some soil under the laboratory conditions. Differences in the concentration of IBP in different soil profiles were few, but amounts of butachlor were remarkably higher at 0-2cm soil depth than below 2cm soil depth.

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A Study on the Multiculturalism Phenomena Expressed in Contemporary Fashion of the End twentieth century (20세기말 현대패션에 나타난 다문화주의(Multiculturalism) 현상에 관한 연구)

  • 최혜정;임영자
    • Journal of the Korean Society of Costume
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    • v.51 no.2
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    • pp.149-167
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    • 2001
  • Today, every culture has taken on the compromise form by means of the cultural difference, variety, and pluralism according to the internationalization and the advance so that it has been developed toward the half-blooded and multilayered the aspect. In accordance with this current of the times, this thesis observed the feminism found in the multiculturism of the end of the 20th century, the third world, and technology with the side of the tendency of modern fashion, considered the hybride phenomenon which is pulling down the wall between culture and genre due to the social diversification. and predicted the fashion trend do 21st century serf on it. Multiculturism is the movement that began to arise in the academic world of America and the literary world form the close of 1980's in accepting the variety of culture and regarding the culture with the more balanced and wide view and just as it is, it means the attitude of accepting one or more cultures of variely and the position of taking interest in the culture of minority race not the culture of a governing race. It is the fashion of feminism adapts dualism like unisex, androgynous look, etc of bisexual lendency in the 1980's, it shows new style with crossover of liberal sense because there is not the difference of sex in fashion. The eco-feminism pursues the natural sexuality not being instrumental and dismantling and expressed it in the Gender expression of an integrated human being. The trend of ethnic fashion in the close of 20th century is that the element of hippie is working so strongly. By adding embroidery of Oriental style, accessories of Indian style, feathers, beads, a hempen hood to the ethnic costumes of Asia and Latin, is shows the figure of ethnic hippie. As the cycler fashion is the future clothes through technology of computer, it uses a cool glass material bringing up the image of a spacesuit in order to expresses cyber image through artificial color combination of sheen colors, Though this techno-color fashion has established the fresh stimulation and the innovative aspect with ultramodern materials and image of futurism, it transmits a hope of estranged people and the natural elements. Hybride means a cross and mixture of animal and plant in Korean and is also called fusion. The phenomenon of hybrid predicts to comes the period of a cross and variation because something completely new comes into the world by contamination, mixture and compromise through meeting something different each other and it has on advantage of developing something existing to one more stage. It is prospected that in the society of 21st century, the borderline of traditional gender will be disappeared, variety and individuality will determine the individual behavior, and the masculine value will be substituted by feminine value. In the society giving priority to feminine value, a fashion stuck closely to women is what must reflect lives of woman under the proposition of woman's beauty, being on original function. So, it is considered that a fashion with added convenience and practicality having the function which is easy to put on, comfortable to act, able to express solves so much, and able to show various appearances according to T.P.O will get into the spotlight.

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Biochemical Characterization of Cysteine(-) Mutant Alanine Racemase from Bacillus pseudomycoides (Bacillus pseudomycoides로 부터 분리된 alanine racemase 유전자의 cysteine 치환 및 생화학적 특성)

  • Kang, Han-Chul;Yoon, Sang-Hong;Lee, Chang-Muk;Koo, Bon-Sung
    • Journal of Applied Biological Chemistry
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    • v.53 no.4
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    • pp.195-201
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    • 2010
  • A gene encoding an alanine racemase in B. pseudomycoides was cloned and one (Cys316) or both of two cysteines (Cys316 and Cys365) was (were) substituted with alanine. The cysteine (-) alanine racemases were expressed in E. coli BL21 (DE3) using a pET-21 vector. The expressed enzymes were purified through affinity chromatography using 6xHis ligand. The purified enzymes all showed major one bands by SDS-PAGE analysis, corresponding to 46 kDa. The cysteine (-) alanine racemases as well as the wild type enzyme showed alanine racemase activities, indicating that the enzyme is an alanine racemase and the cysteines in the enzyme may not be involved in the catalysis and/or substrate binding. Thermal stabilities of Cys (-) alanine racemases decreased considerably and half-lives were 26 (wild type), 21 (C316A) and 18 min (C316-365A), respectively at $60^{\circ}C$ pH 8.0, suggesting that cysteine is considerably contributive to the thermal stability of the alanine racemase.

Residue safety on ethephon in soybean leaf by drenching and foliar application (에테폰의 관주처리와 엽면살포에 의한 콩 잎 중 잔류 안전성)

  • Kong, Seung-Heon;Lee, Deuk-Yeong;Song, Young-Hoon;Park, Ki-Hun;Seo, Woo-Duck;Lee, Dong-Yeol;Kim, Jin-Hyo
    • Journal of Applied Biological Chemistry
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    • v.61 no.1
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    • pp.75-78
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    • 2018
  • Ethephon is useful pesticide as ethylene precursor, which is an efficient plant hormone to produce functional secondary metabolites. However, the residual safety of ethephon was not studied on various crops. In here, the dissipation pattern of ethephon residue in soybean leaf was investigated both on the foliar and drenching applications. The biological half-lives of ethephon residues were 26.6, and 21.1 h on the once, and double foliar applications, respectively. Although the residue after three days from the final application was up to $60.6mg\;kg^{-1}$, the residue was below the limit of quantitation on the dried soybean leaf. In addition, drenching application of ethephon could increase the residue up to $36.3mg\;kg^{-1}$ after 20.1 h from the application, however, the treatment would not affect to the total phenol content significantly (p >0.01).

Adsorption and Leaching Characteristics of the Insecticide Imidacloprid in Paddy Soils (살충제 Imidacloprid의 논토양 중 흡착 및 용탈 특성)

  • Ihm, Yang-Bin;Kyung, Kee-Sung;Kim, Chan-Sub;Lee, Hee-Dong;Ryu, Gab-Hee;Lee, Jae-Koo
    • Korean Journal of Environmental Agriculture
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    • v.25 no.1
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    • pp.58-63
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    • 2006
  • In order to elucidate the adsorption and leaching characteristics of the insecticide imidacloprid in two types of paddy soils near Suwon, this experiment was carried out with $[^{14}C]$imidacloprid as a radiotracer. In an adsorption study conducted using $[^{14}C]$imidacloprid in 2 test soils, the adsorption coefficient was higher in soil A $(K_f\;2.6)$ than that in soil B $(K_f\;1.7)$. As calculated from Freundlich constant, distribution coefficients and half lives in soils, GUS indices showed low leachabilities of imidacloprid treated on the paddy soils into the groundwater. The amount of imidacloprid leached from the soil columns during the 4 weeks of leaching was less than 2% of the originally treated $^{14}C$. In the leaching test the amounts of $^{14}C$ activities distributed in the soil layer of 0-10 cm were more than 80% of the originally tented $^{14}C$ and those in rice plants were less than 3% of the originally treated $^{14}C$, suggesting that imidacloprid has very low teachability and bioavailability.

Consumer Trends on Dietary and Food Purchasing Behaviors and Perception for the Convenience Foods (한국형 건강 편의식 개발 방향 도출을 위한 소비자의 식행동 및 인식 조사)

  • Yoon, Sun;Sohn, Kyung-Hee;Kwak, Tong-Kyung;Kim, Jung-Soo;Kwon, Dae-Joong
    • Journal of the Korean Society of Food Culture
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    • v.13 no.3
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    • pp.197-206
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    • 1998
  • This study was attempted to identify emerging consumer trends on dietary and food purchasing behaviors and perception for the convenience foods. Self completed questionnaires were collected from 710 housewives in Seoul and Kyunggi province and analyzed statistically. A questionnaire consisted of 3 parts including demographic backgrounds, dietary and food purchasing behaviors, perception for the convenience foods. Among demographic variables age, occupation and lifestyle were the significant factors affecting consumers' behaviors and perception of dietary lives. Over half of housewives, who are the primary persons responsible for home meal preparation, confessed that they do not enjoy meal planning and preparation any more. An attitude toward in home food preparation was significantly different among age groups, working or non-working women and lifestyles. Most of the respondents go shopping for foods whenever they need to or 2-3 times a week. They also did not plan before going foods shopping and purchase decisions were made in-store. They considered quality of foods more important than price. Consumers were not willing to purchase pre-cut packaged vegetables or pre-cooked foods on the market. However, they showed strong desire and demand for the development of convenience korean foods coupled with high quality.

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Pharmacokinetics of Arsenic Hexaoxide, a Anticancer Compound, in Rats (흰쥐에서 항암성화합물인 육산화비소의 체내동태)

  • Lee, Pung-Sok;Shin, Dae-Hwan;Lee, So-Young;Lee, Jung-Yeol;Lee, Kyoung-Mi;Kwon, Koo-Hyun;Chung, Youn-Bok
    • Journal of Pharmaceutical Investigation
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    • v.36 no.6
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    • pp.377-383
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    • 2006
  • The purpose of the present study was to examine the pharmacokinetic characteristics of arsenic hexaoxide($As_4O_6$), a novel anticancer compound, after i.v. bolus and oral administration in rats. We developed an ICP-Mass based method to analyze arsenic hexaoxide levels in plasma, bile, urine, feces, and tissue and validated the method. Arsenic hexaoxide rapidly disappeared from the plasma by 10 min($\alpha$ phase) after i.v. administration, which was followed by the late disappearance in the $\beta$ phase. The mean plasma half-lives($t_{1/2}$) of arsenic hexaoxide at the a and $\beta$ phase when administered at a dose of 5 mg/kg were 1.57 and 29.8 min, respectively. The maximum plasma concentration($C_{max}$) was 230 ng/mL, after oral administration of arsenic hexaoxide at a dose of 50 mg/kg. The bioavailability, which was calculated from the dose-adjusted ratio, of the oral administered arsenic hexaoxide was 1.61%. Of the various tissues tested, arsenic hexaoxide was mainly distributed in the spleen, lung, liver and kidney after oral administration. Arsenic hexaoxide levels in the spleen or lung at 24 hr after oral administration were higher than those of maximum plasma concentration($C_{max}$). The cumulative amounts of arsenic hexaoxide found in the urine by 48 hr after the administration of 50 mg/kg were 5-fold higher than those in the bile. However, the cumulative amounts in the feces were 10-fold higher compared with those of urine, suggesting that arsenic hexaoxide is mostly excreted in the feces. In conclusion, our observations indicated that arsenic hexaoxide was poorly absorbed from the gastro-intestinal tract to the blood circulation and transferred to tissues such as the spleen and lung at 24 hr after oral administration. Moreover, the majority of arsenic hexaoxide appears to be excreted in the feces by 48 hr after oral administration.

Pharmacokinetics and Lymphatic Delivery of Oligopeptide after Intramuscular Injection of Oligopeptide-bearing Liposomes to Rats (흰쥐에서 올리고펩타이드 함유 리포솜의 근육주사후 체내동태 및 임파이행)

  • Shin, Dae-Hwan;Cho, Byung-Suk;Choi, Kyu-Seok;Song, Suk-Gil;Lee, Chong-Kil;Chung, Youn-Bok
    • Journal of Pharmaceutical Investigation
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    • v.38 no.3
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    • pp.191-197
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    • 2008
  • The purpose of the present study was to examine the pharmacokinetics and lymphatic delivery of the oligopeptide, a model peptide of X antigen epitope peptides, after the intramuscular administration of the peptide-bearing liposomes in rats. $^{14}C$-labelled peptide was used as a tracer to analyze the peptide levels in plasma, bile, urine, tissue homogenates, and lymph nodes (superior cervical nodes, brachial nodes and superior mesenteric nodes). Model peptide rapidly disappeared from the plasma by 30 min (${\alpha}$ phase) after i.v. administration, which was followed by the late disappearance. The apparent plasma half-lives ($t_{1/2({\alpha}),app}$) of the peptide at the ${\alpha}$ phase when administered at a dose of 0.2-1.0 mg/kg were about 5 min. The maximum plasma concentration ($C_{max}$) was $1.52\;{\mu}g/mL$, after the i.m. administration of the peptide at a dose of 1.0 mg/kg. The bioavailability, which was calculated from the time zero to last quantitative time, of the i.m. administered peptide was over 60%. Of the various tissues tested, the peptide was mainly distributed in the kidney after the i.m. administration. The peptide levels in the kidney 3 hr after the i.m. administration were higher than those of maximum plasma concentration ($C_{max}$). The cumulative amounts of the peptide found in the urine 72 hr after the administration of 1.0 mg/kg were 2-folder higher than those in the bile, suggesting that the peptide is mostly excreted in the urine. Moreover, the concentrations of the peptide in the lymph nodes were as high as that of the plasma and the tissues. In conclusion, the peptide concentration in the lymph nodes was maintained by 24 hr after the i.m. administration of the peptide-bearing liposomes.

Residual Characteristics of Etofenprox and Methoxyfenozide in Chinese Cabbage (Etofenprox와 Methoxyfenozide의 배추 중 잔류특성)

  • Lee, Eun-Young;Noh, Hyun-Ho;Park, Young-Soon;Kang, Kyung-Won;Kim, Joo-Kwang;Jin, Yong-Duk;Yun, Sang-Soon;Jin, Chung-Woo;Han, Sang-Kuk;Kyung, Kee-Sung
    • The Korean Journal of Pesticide Science
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    • v.13 no.1
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    • pp.13-20
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    • 2009
  • Two insecticides, commonly used for Chinese cabbage, etofenprox and methoxyfenozide, were subjected to a field residue trial to evaluate safeties of the residues at harvest. The pesticides were sprayed onto the crop at recommended and double doses 10 days before the prearranged harvest and then sampling was done at 0, 1, 2, 3, 5, 7, 10, and 12 days after spraying. The amounts of pesticides residues in the crop were analyzed by chromatographic methods. Limits of detection (LODs) of both etofenprox and methoxyfenozide were $0.01mg\;kg^{-1}$ and mean recoveries were $96.76{\pm}2.67$ (CV=2.76%) and $95.84{\pm}2.57%$(CV=2.69%) in case of etofenprox and $103.26{\pm}3.21$ (CV=3.11%) and $94.50{\pm}1.35%$(CV=1.43%) in case of methoxyfenozide, respectively. Biological half-lives of etofenprox and methoxyfenozide were 3.2 and 3.5 days at the recommended dose and 2.7 and 3.5 days at the double dose, respectively. Initial residue levels of the pesticides at the recommended and double doses exceeded their MRLs, but final residue levels of the pesticides in the crop samples at harvest were less than their MRLs. The ratios of the EDI to ADI by intake the crop harvested 10 days after spraying were less than 4% of their ADIs, representing that residue levels of two pesticides at harvest were evaluated as safe.

Biodegradation Characteristics of Aldehydes using Biological Activated Carbon Process (생물활성탄 공정을 이용한 오존처리 부산물인 aldehyde류의 생분해 특성평가)

  • Ko, Jae-Hyun;Son, Hee-Jong;Kim, Young-Jin;Bae, Seog-Moon;Yoo, Pyung-Jong;Lee, Tae-Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.11
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    • pp.989-996
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    • 2009
  • In this study, the effects of biofilter media type (three different activated carbons and anthracite), empty bed contact time (EBCT) and temperature on the removal of four aldehyde species (formaldehyde, acetaldehyde, glyoxal and methylglyoxal) in BAC filters were investigated. Experiments were conducted at three water temperature (5, 15 and $25^{\circ}C$) and four EBCTs (5, 10, 15, and 20 min). The experimental results indicated that the coal based BAC retained more bacterial biomass on the surface of the activated carbon than the other BACs, and increasing EBCT or increasing water temperature also increased the four aldehyde species removal in BAC filters. To achieve above 80% of removal efficiency for four aldehyde species in a BAC filter, above 15 min EBCT at $5^{\circ}C$ and 10 min EBCT at above $15^{\circ}C$ were required. The kinetic analysis indicated a first-order reaction rate for the biodegradation of four aldehyde species at various water temperatures. Data obtained from the BAC filters at various temperatures were also used to evaluate pseudo first-order rate constants for four aldehyde species. The half-lives evaluated for formaldehyde, acetaldehyde, glyoxal and methylglyoxal in the coal-based BAC ranging from 0.89 to 3.19 min, from 0.75 to 3.35 min, from 2.16 to 4.72 min and from 1.49 to 3.86 min, respectively, could be used to assist water utilities in designing and operating BAC filters.