• Title/Summary/Keyword: half-lives

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Studies on Persistence of Pesticides in Soils and Crops under Polyethylene Film Mulching Culture;III. Persistence of Soil Insecticides Endosulfan, Fonofos and Ethoprophos (폴리에틸렌 멀칭재배시(栽培時) 농약(農藥)의 토양(土壤) 및 작물체중(作物體中) 잔류(殘留)에 관한 연구(硏究);제(第)3보(報) 토양살충제 Endosulfan, Fonofos, Ethoprophos의 잔류성(殘留性))

  • Ryang, Hwan-Seung;Moon, Young-Hee;Kim, Nak-Eung
    • Korean Journal of Environmental Agriculture
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    • v.7 no.1
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    • pp.8-13
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    • 1988
  • This experiment was conducted to evaluate the effect of polyethylene film(P.E.) mulching on degradation of the soil insecticides, endosulfan(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide), fonofos(O-ethyl S-phenyl ethylphosphonodithioate), and ethorprophos(O-ethyl S, S-dipropyl phosphorodithioate) in red pepper, peanut, and sesame fields. Degradation of endosulfan, fonofos and ethoprophos in the soils under P.E. mulching and non-mulching followed first-order kinetics. The half-lives of fonofos, ethoprophos, ${\alpha}-$ and ${\beta}-endosulfan$ were $19{\sim}21$, $25{\sim}37$, $33{\sim}39$ and $56{\sim}81$ days, respectively. There were few differences in the half-lives of fonofos in either mulching or non-mulching concitions. However, half-lives of α-endosulfan, ethoprophos, and ${\beta}-endosulfan$ were 6, 12 and 25 days longer under P.E. mulching than under non-mulching conditions, respectively. The effect of P.E. mulching on degradation was remarkable for the slower degrading insecticides. Residues of ethoprophos in the harvested sesame under P.E. mulching and non-mulching conditions were 0.024 and 0.074ppm, respectively. Residues of fonofos in the harvested peanuts under P.E. mulching and non-mulching conditions were 0.078 and 0.017ppm, respectively. However, no endosulfan was detected in the harvested red peppers under either condition.

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Pharmacokinetics and Tissue Distribution of Recombinant Human Erythropoietin (DA-3285) in the Laboratory Animals (Recombinant human erythropoietin (DA-3285)의 실험동물에서의 약동력학 및 조직분포)

  • 심현주;이응두;이종진;김흥재;이상득;이성희;김원배;양중익
    • Biomolecules & Therapeutics
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    • v.4 no.1
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    • pp.78-83
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    • 1996
  • The pharmacokinetics and tissue distribution of DA-3285 (recombinant human erythropoietin, recently manufactured by Research Laboratories of Dong-A Pharmaceutical Company) were studied in the laboratory animals. The plasma, urine, and tissue concentration of DA-3285 were measured by a double-antibody sandwich enzyme immunoassay. After intravenous administration of DA-3285, 20, 100, 500 and 2500 units/kg to rats, the plasma concentrations declined polyexponentially with the terminal half-lives of 2.15, 2.10, 2.31, and 2.35 hr, respectively. Total body clearance (20.7∼26.6 mι/hr/kg) and apparent volume of distribution at steady state (57.2∼70.1 mι/kg) were independent of the dose and AUC increased proportionally with the dose. The renal clearance was much lower than total body clearance, suggesting that extrarenal clearance, presumably metabolism , plays a significant role in elimination of DA-3285. In all rat tissues, the tissue to plasma ratios were smaller than unity, indicating less affinity of DA-3285 to rat tissues and was proved by considerably less value of Vdss. After 3 times a week for consecutive 3 weeks i.v. administration of DA-3285, 100 units/kg to rats, the plasma concentrations and pharmacokinetic parameters of DA-3285 were not significantly different from those in a single administration. After s.c. administration to the rat, plasma concentrations of DA-3285 peaked at 6 hr and the extent of bioavailability was 26.7%. In mice, rabbits and dogs, at DA-3285 dose of 100 units/kg, the mean terminal haw-lives were 2.78, 3.05, and 4.01 hr, respectively. Compared with reported data in the literatures, DA-3285 has similar properties to rh-EPO manufactured by other companies in view of pharmacokinetics.

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A Study on the health care with eating food and exercise (음식섭취와 운동를 통한 건강관리 유형 연구(전문가 집단을 중심으로))

  • 김기영
    • Culinary science and hospitality research
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    • v.5 no.1
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    • pp.27-48
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    • 1999
  • This article a little bit lack of elements for the basis of study of health care in the respect of taking a certain expert group as the sample. However researcher chose people who is in same situation with himself and tried to make clear how to do for their behavior of health care to know that how the experts groups are taking care of their health. For the study, the main aim of this article is studying the health care situation of experts group which is taking crucial role in the economy, society and cultural field. When it comes to the experts group's health care by eating habits and exercise related program is, first, it indicates that most people are eating for their health, lives and work through the analysis of responds; they eat food for their health and their health, lives or task.(Surely they family-centered structure. Third, 78% of 40s group responded that they enjoy finding good restaurants while 20s to 30s are enjoying fastfood and instant food instead of Korean traditional foods. fourth, health care by the exercise is done in one or half one hour and the dependant exercises like jogging or swimming which can be done whenever they have time are perferred to group exercise. It's desirable that one has to take care of himself with systematic and effective way. But it's very difficult and care for most people to take care of themselves, so they have to make the program and practice it systematically. The result from this study shows that practicing the health related program rationally, at the same time increasing leisure time and doing dependant or group exercise, taking a walk, and various kind of exercise considered spending money are more common than eating foods for health care. These are regarded as a desirable phenomenon in terms of the health care.

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An Investigation of Dietary Behaviors in Korea and Japan (Part I) -On Employment of Dietary Equipments- (한국(韓國)과 일본인(日本人)의 식행동(食行動)에 관(關)한 조사연구(調査硏究)(제1보(第1報)) -식기구류(食器具類)의 사용(使用)에 관(關)하여-)

  • Kim, Chon-Ho;Hara, Fumiko
    • Journal of the Korean Society of Food Culture
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    • v.4 no.1
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    • pp.59-69
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    • 1989
  • As for the Japanese dietary style and dietary equipments, many are regarded, with the rice plant imported, as the influence of China and Korea, while traditional culture has recently changed in Japanese and Korean urban lives because of the increase of nuclear families and modernization of lives. Of 1,244 junior high school students of boys and girls in Tokyo and Seoul, we investigated the present situations of the employment of dining equipments October to November, 1987. The results obtained are as follows. More cases that each member of a family had his or her own dining equipment were found in Japan. The frequency of using chopsticks was high in both countries. Korean children, having no struggles, handled chopsticks better than Japanese children. As for the dishing-up of sidedishes, more than half of Japanese used their individual plates, while in Korean families they used whole dishes. As for the employment of dining equipments, Japanese people have established their own style because of the national character of delicacy and finicality. This kind of traditional habits were found much more in extended families than in nuclear families. In Korea, the traditional spirit and the broad-minded characteristics cherished in the continental circumstances were manifested in the employment of dining equipments and their strong national character will not easily accept the wave of modernization.

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Changes in the serum immunoglobulin levels and viral antibody titers of colostrum-conferred Korean native calves during the first 12 weeks postpartum (초유를 섭취한 한우 송아지의 출생후 12주 동안의 혈청 면역글로불린과 각종 바이러스 항체가의 변화)

  • Kim, Doo;Han, Hong-ryul
    • Korean Journal of Veterinary Research
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    • v.29 no.2
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    • pp.83-90
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    • 1989
  • The changes in serum total protein and immunoglobulin levels, and BVD, IBR and PI-3 viral neutralizing antibody titers in colostrum-conferred Korean native calves during the first 12 weeks postpartum were studied, and the results obtained were summerized as follows: The Mean concentration of total protein, total immunoglobulin, IgG, IgM and IgA in sera of 9 calves at birth were $3.8{\pm}0.5g/dl$, $0.27{\pm}0.15mg/ml$, $0.06{\pm}0.08mg/ml$, $0.21{\pm}0.11mg/ml$, and extremely low concentration, respectively. Serum total protein level reached a maximum at 20 hours after birth, total immunoglobulin, IgG, and IgM levels at 24 hours, and IgA level at 28 hours, respectively. Serum IgA level reached a minimum at 4 weeks old, IgM level at 5 weeks, total immunoglobulin level at 8 weeks, and IgG level at 10 weeks, respectively. After then those levels had begun to increase, but total protein level was still decreasing at 12 weeks old. The half-lives of IgG, IgM, and IgA were 21.1 days, 4.0 days, and 2.6 days-respectively. In 10 Korean native cows immediately after parturition, serum neutralizing antibody titers specific to BVD, IBR and PI-3 virus were $8.7{\pm}1.5{\log}_2$, $5.7{\pm}1.2{\log}_2$, and $6.8{\pm}1.01{\log}_2$, respectively. And colostral neutralizing antibody titers against BVD, IBR, and PI-3 virus were $10.1{\pm}1.4{\log}_2$, $6.8{\pm}1.3{\log}_2$ and $7.8{\pm}1.7{\log}_2$, respectively. Before suckling the colostrum, SN antibody titers against BVD, IBR, and PI-3 virus were undetectable from all of 9 Korean native calves. Nevertheless SN antibody titer against BVD virus reached a maximum level ($9.2{\pm}0.6{\log}_2$) at 24 hours after birth, that against IBR virus ($6.1{\pm}1.0{\log}_2$) at 20 hours after birth, and that against PI-3 virus ($6.8{\pm}0.9{\log}_2$) at 32 hours after birth, respectively. In 12 weeks old calves, the SN antibodies against BVD and IBR virus were still decreasing, but that against PI-3 virus reached a minimum at 10 weeks, and increased after 12 weeks of age. The half-lives of SN antibodies against BVD, PI-3 and IBR, virus were 16.0 days, 22.6 days, and 25.5 days, respectively.

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Dissipation of Cyclosulfamuron in Rice Paddies (수도 재배환경 중 제초제 Cyclosulfamuron의 잔류특성)

  • Lee, Young-Deuk;Song, Sung-Do
    • Korean Journal of Environmental Agriculture
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    • v.20 no.4
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    • pp.269-276
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    • 2001
  • Several experiments including persistence, distribution, leaching, and terminal residue trials were carried out to investigate the behavior of cyclosulfamuron in rice paddies. Cyclosulfamuron was gradually dissipated in two different soils showing the first-order kinetics. Half-lives of the herbicide were calculated to be $17{\sim}30$ and $14{\sim}16$ days under field and laboratory conditions, respectively. In the paddy soil/water system, the residue tended to reside more in the soil phase as time elapsed. Cyclosulfamuron was less persistent in paddy water than in soil with half-lives of 10 and 19 days, respectively. No cyclosulfamuron was leached below 20 cm-deep soil during water percolation with 50 cm hydraulic head, while some downward mobility was observed within the soil column. When EC and SC formulations of cyclosulfamuron were applied to the paddy field at 120 or 150-day pre-harvest intervals, its terminal residues in hulled rice were all less than 0.01 mg/kg, irrespective of formulation type and application timing. In rice straw, however, some residues were found at $<0.02{\sim}0.05$ mg/kg as SC formulation was applied. Rapid dissipation, restricted mobility, and low terminal residues of cyclosulfamuron in rice paddies suggest that no significant residues would be transported or carried over to the non-target environment.

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Residual Characteristics of Insecticides Used for Oriental Tobacco Budworm Control of Paprika (파프리카 재배기간 중 담배나방 방제에 사용되는 살충제의 잔류특성)

  • Lee, Dong Yeol;Kim, Yeong Jin;Kim, Sang Gon;Kang, Kyu Young
    • Korean Journal of Environmental Agriculture
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    • v.32 no.1
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    • pp.84-93
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    • 2013
  • BACKGROUND: This study was carried out to investigate the residual characteristics of insecticides used for Oriental Tobacco Budworm control and to establish the recommended pre-harvest residue limit leading to contribution in safety of paprika production. METHODS AND RESULTS: The recommended Pre-Harvest Residue Limits (PHRLs) of insecticides during cultivation of paprika were calculated from residue analyses of insecticides in fruits 1, 3, 5, 7, 10, 12, 15, 18 and 21 days after treatment. Paprika samples were extracted with QuEChERS method and cleaned-up with amino propyl SPE cartridge and PSA, and insecticide residues were analyzed either by HPLC/DAD or GLC/ECD. The limits of detection were 0.01 mg/kg for 5 insecticides. Average recoveries were $81.3{\pm}1.62%$-$98.3{\pm}1.58%$ of 5 insecticides at fortification levels of 0.1 and 0.5 mg/kg. The biological half-lives of the insecticides were 8.5 days for bifenthrin, 11.8 days for chlorantraniliprole, 16.8 days for chlorfenapyr, 7.1 days for lamda-cyhalothrin and 31.3 days for methoxyfenozide at recommended dosage, respectively. CONCLUSION(S): The pre-harvest residue limits for 10 days before harvest were recommended 1.05 mg/kg, 1.41 mg/kg, 0.93 mg/kg, 2.06 mg/kg and 1.08 mg/kg as bifenthrin, chlorantraniliprole, chlorfenapyr, lamda-cyhalothrin and methoxyfenozide, respectively. This study can provide good practical measures to produce safe paprika fruit by prevention of products from exceeding of MRLs at pre-harvest stage.

A Study on the Biodegradability of Some Pesticides in Water (물 중에서 일부 농약의 생분해성에 환한 연구)

  • 민경진;차춘근
    • Journal of Food Hygiene and Safety
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    • v.16 no.2
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    • pp.125-132
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    • 2001
  • The present study was conducted to investigate biological degradability of phosphamidon and profenfos. In the biodegradation test of two pesticides by the modified river die-away method from May 20 to July 29, 1999, the biodegradation rate was determined in Nakdong (A) and Kumho(B) River. The residual percentages of phosphamidon were 74.9%, 68.8% and 62.7% in control, A and B samples 7 days after applicaton, respectively. Biodegradation constants and half-lives of phosphamidon were 25.1%, 21.9% and 11.9% in control, A and B samples 7 days after application. Biodegradation constants and half-lives of profenofos were 0.0005 and 58.4 days in A, 0.0013 and 21.6 days in B, respectively. The biodegradation rates of phosphamidon and profenofos were higher in the Kumho River (B) than in the Nackdong River(A). The strains of microorganisms for the degradation of phosphamidon and profenofos were identified as Klebsiella pneumoniae, Aeromonas hydrophila and Acinetobacter calcoaceticus, all Gram-negative bacteria. In order to identify biodegradate products, the extracts of cultivates were analyzed by GC/MS. The mass spectra of biodegradate roducts of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. It was suggested that the biodegradate metabolites of phosphamidon were O, O-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, those of profenofos were 4-bromo-2-chlorophenol and O-ethyl-S-propyl phosphate.

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Leaching and Adsorption of Flupyrazofos(KH-502) in the Soil (Flupyrazofos(KH-502)의 토양 중 용탈 및 흡착)

  • Yang, Jae-E;Cho, Boo-Yeon;You, Kyoung-Youl
    • Korean Journal of Environmental Agriculture
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    • v.16 no.1
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    • pp.72-79
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    • 1997
  • Adsorption, leaching, and retention of the Flupyrazofos(KH-502), a new active ingredient for insecticide, in the soils under laborarory and field conditions were investigated to provide the basic data for the safety use and to assess a secondary impact of this insecticide on soil and water environments. A significant power function relation was found between the adsorbed KH-502 and time, representing that 45% of the added KH-502 was adsorbed within 30 min. but a quasiequilibrium was reached after 6 to 12 hr with a slower adsorption. Adsorption phenomena followed th first-order kinetics and time required for 50% adsorption was 5.8 hr. The equilibrium adsorption isotherm was explained by the Freundlich equation and was classified as S-type. The amounts of KH-502 leached through the soil column (C) as compared to initial conc. ($C_0$) were very low and these relative concentrations ($C/C_0$) were 0.073 and 0.017 in SL and CL soils, respectively. The residual conc. of KH-502 in the surface soil was comparatively low and decreased with time. Half-lives of KH-502 in the surface soil was comparatively low and decreased with time. Half-lives of KH-502 under the field conditions were estimated to be 20 and 18 days in the SL and CL soils, respectively. The KH-502 cone, transported to the subsurface soils was extremely low. These results demonstrate that KH-502 has a low pollution risk potential to the surrounding environment as far as it is used following the recommended guideline.

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Translocation of Polychlorinated Biphenyls in Carrot-Soil Systems (Polychlorinated Biphenyl의 작물-토양간 흡수 이행성)

  • Lim, Do-Hyung;Lim, Da-Som;Keum, Young-Soo
    • The Korean Journal of Pesticide Science
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    • v.20 no.3
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    • pp.203-210
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    • 2016
  • Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants, found in the many environments. PCBs exerts various toxicological effects, including endocrine-disrupting activity. Most researches with these toxicants performed with soil matrix with mixtures of congeners, namely Aroclor, while the biological activities have been tested with animals. However, studies with pure congeners are limited. In this study, 5 congeners were synthesized and their fates (bioaccumulation, degradation, kinetics) were studied in carrot-soil system. The soil half-lives of biphenyl, PCB-1, PCB-3, PCB-77, and PCB-126 were 20.2, 16.0, 11.6, 46.5, 198.0 days, respectively. In general, the longer half-lives were observed with the higher hydrophoicity of PCBs. Times, required for maxium accumulation of PCBs in carrot (Tmax) were 10-20 days for most congeners and the concentrations were 0.4-2.6 mg/kg. The concentrations of PCBs in carrot were kept as constant after Tmax, except PCB-126. The concentration ratio between carrot and soil after 90 days of treatment were 1.7, 8.1, 1.9, 1.8, and 5.9 for biphenyl, PCB-1, PCB-3, PCB-77, and PCB-126. Because of the increase of biomass, the total residual amount of PCBs in carrots however, increased till the end of experiment. The portions of PCB-126 in carrot were 1.1% of the soil residues at 90 days after planting.