• Title/Summary/Keyword: Half-lives

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Residual characteristics of Neonicotinoid Insecticide dinotefuran and thiacloprid in cucumber (Neonicotinoide계 농약 dinotefuran과 thiacloprid의 오이 중 잔류특성)

  • Lee, Eun-Young;Noh, Hyun-Ho;Park, Young-Soon;Kang, Kyung-Won;Lee, Kwang-Hun;Park, Hyo-Kyung;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.2
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    • pp.98-104
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    • 2009
  • This study was carried out to investigate the residue patterns of two neonicotinoid insecticides, dinotefuran and thiacloprid, commonly used for cucumber, were subjected to indicate a residual characteristic under greenhouse conditions. The pesticides were sprayed onto the crop at recommended and double doses 7 days before harvest and then sampling was done 0, 2, 3, 5, and 7 days after spraying. The amounts of their residues in the crop were analyzed with an HPLC. Their detection limits were 0.01 mg/kg for dinotefuran and 0.005 mg/kg for thiacloprid. Mean recoveries of dinotefuran and thiacloprid were from 85.78 to 89.52 and from 85.71 to 95.31%, respectively. Half-lives of dinotefuran and thiacloprid were 2.8 and 1.8 days at the recommended dose and 2.8 and 1.5 days at the doubled dose, respectively. The ratios of the EDI to ADI by intake the crop harvested 7 days after spraying were less than 0.1% of their ADIs.

Assessment of Food Service Management Practices in Child Care Centers Operated by Various Types of Foundations in the Chonbuk Area of Korea (전북지역 보육시설의 시설유형에 따른 급식운영관리 실태 조사)

  • Rho, Jeong-Ok;Lee, Eun-Pa;Lee, Jin-Sook
    • Korean journal of food and cookery science
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    • v.25 no.1
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    • pp.74-83
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    • 2009
  • We investigated the food service management practices in child care centers operated by various types of foundations in the Chonbuk area of Korea. Self-administered questionnaires were collected from 125 child care center directors. The statistical analysis was completed using an SPSS v11.5 program. Approximately 82.4% of the directors were women with an the average age of 45 years old. The average number of children in each public and private child care center was 84.7 and 88.8, respectively (P<.001), and the difference in time of operation was significant(P<.001). Only 20.8% of the centers employed a dietitian, whereas 92.0% of the centers employed a cook, thus, food service was not managed by professionals in most centers. In approximately 99.2% of the centers, meals were prepared in a conventional manner. The difference in daily meal frequency was significant(P<.05), with approximately 85.6% of the centers serving snacks twice a day primarily to supplement the intake of nutrients(4.44 point) and to add fun to the daily lives of the children(4.12 point). Approximately 40.7% of the directors of public centers and 57.6% of the directors of private centers responded that the most difficult aspect of food service management was financial management. Overall, 56.8% of the directors responded that the details of financial management had the greatest effect on their ability to improve the quality of food service. In most centers, the center director was also the purchasing manager and half of them purchased food every day. Approximately 97% of the directors responded that they do not include instant foods in their menu plans but they would use them if the children wanted to eat them. These results indicate that the food service management in child care centers in the Chonbuk area is relatively inadequate. We strongly recommend that they hire dietitians for food service administration and focus on strengthening sanitation management.

Contaminative Influence of Beef Due to the Inhalation of Air and the Ingestion of Soil of Livestock from an Acute Release of Radioactive Materials (원자력시설의 사고시 가축의 공기 흡입과 토양 섭취가 육류의 방사능 요염에 미치는 영향)

  • 황원태;김은한;서경석;정효준;한문희
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.3
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    • pp.181-188
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    • 2004
  • The contaminative influence of beef due to the inhalation of air and the ingestion of soil of livestock, both of which are dealt with as minor contaminative pathways in most radioecological models but may not be neglected, was comprehensively investigated with the improvement of the Korean food chain model DYNACON. As the results, it was found that both pathways can not be neglected at all in the contamination of beef in the case of an accidental release during the non-grazing period of livestock. The ingestion of soil was more influential in the contamination of beef than the inhalation of air over most time following an release. If precipitation is encountered during an accidental release, contaminative influence due to the ingestion of soil was far greater compared with the cases of no precipitation. This fact was more distinct for a long-lived radionuclide $^{l37}Cs$ than a short-lived radionuclide $^{131}I$ (elemental iodine). Compared with the results for milk performed prior to this study, the contaminative pathways due to the inhalation of air and the ingestion of soil were more important in beef because of longer biological half-lives. On the other hand, in the case of an accidental release during the grazing period of livestock, radioactive contamination due to the ingestion of pasture was dominant irrespective of the existence of precipitation during an accidental release. It means that contaminative influence due to the inhalation of air and the ingestion of soil is negligible, like the cases of milk.

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Landslide Susceptibility Mapping by Comparing GIS-based Spatial Models in the Java, Indonesia (GIS 기반 공간예측모델 비교를 통한 인도네시아 자바지역 산사태 취약지도 제작)

  • Kim, Mi-Kyeong;Kim, Sangpil;Nho, Hyunju;Sohn, Hong-Gyoo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.5
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    • pp.927-940
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    • 2017
  • Landslide has been a major disaster in Indonesia, and recent climate change and indiscriminate urban development around the mountains have increased landslide risks. Java Island, Indonesia, where more than half of Indonesia's population lives, is experiencing a great deal of damage due to frequent landslides. However, even in such a dangerous situation, the number of inhabitants residing in the landslide-prone area increases year by year, and it is necessary to develop a technique for analyzing landslide-hazardous and vulnerable areas. In this regard, this study aims to evaluate landslide susceptibility of Java, an island of Indonesia, by using GIS-based spatial prediction models. We constructed the geospatial database such as landslide locations, topography, hydrology, soil type, and land cover over the study area and created spatial prediction models by applying Weight of Evidence (WoE), decision trees algorithm and artificial neural network. The three models showed prediction accuracy of 66.95%, 67.04%, and 69.67%, respectively. The results of the study are expected to be useful for prevention of landslide damage for the future and landslide disaster management policies in Indonesia.

Absorption of soil residual azoxystrobin to lettuce (상추 재배토양 중 잔류 Azoxystrobin의 작물흡수)

  • Kim, Min-Gi;Hwang, Kyu-Won;Hwang, Eun-Jung;Yoo, Soo-Cheol;Moon, Joon-Kwan
    • Journal of Applied Biological Chemistry
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    • v.60 no.4
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    • pp.343-349
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    • 2017
  • This study was conducted to investigate the residual level and the amount of transfer to lettuce grown in field condition treated with the 5-methyl-1,2,4-triazolo[3,4-b][1,3]benzothiazole (Azoxystrobin). The field trials on lettuce were carried out at two different green houses located in Gwangju (Field 1) and Yongin (Field 2). Soil and lettuce samples were collected at different days after soil treatment of azoxystrobin with two different concentrations, respectively. Average recoveries for azoxystrobin ranged from 86.9 to 113.6% from soil and lettuce with the variation coefficient of 0.1-4.6%. The initial concentrations of azoxystrobin in Gwangju soil were 9.20, 11.00 mg/kg and decreased to 1.36, 2.70 mg/kg at 43 DAT (days after treatment) in field 1, while 1.06, 2.23 mg/kg decreased to 0.20 and 0.67 mg/kg at 36 DAT in field 2, respectively. The half-lives of azoxystrobin were about 19.4 and 23.3 days for the low and high concentration of azoxystrobin treated soils in field 1 and 11.5 and 17.8 days in field 2 soils, respectively. Residue levels of azoxystrobin in lettuce were not detected in filed 1 and field 2 soils, respectively.

Inhibition of Enzymatic Degradation of Leucine Enkephalin and $[D-Ala^2]$-Leucine Enkephalinamide in Various Rabbit Mucosal Extracts by Inhibitors (효소 억제제에 의한 토끼의 점막 추출액중 로이신엔케팔린 및 [D-알라$^2$-로이신엔케팔린아미드의 분해 억제)

  • Chun, In-Koo;Park, In-Sook;Hyun, Jeen
    • Journal of Pharmaceutical Investigation
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    • v.26 no.3
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    • pp.175-185
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    • 1996
  • To inhibit the enzymatic degradation of leucine enkephalin (Leu-Enk) and its synthetic analog. $[D-ala^2]$-leucine enkephalinamide (YAGFL), in the nasal, rectal and vaginal mucosal and serosal extracts of rabbits, effects of enzyme inhibitors such as amastatin (AM), puromycin (PM), thiorphan (TP), thimerosal (TM), EDTA, N-carboxymethyl-Phe-Leu (CPL), phenylethyl alcohol (PEA), phenylmercuric acetate (PMA), benzalkonium chloride (BC) and modified cyclodextrins, alone or in combination, were observed by assaying the pentapeptides staying intact during incubation. Mucosa extracts were prepared by exposing freshly-excised mucosal specimens mounted on Valia-Chien cells to isotonic phosphate buffer while stirring. The degradation of Leu-Enk and YAGFL followed the apparent first-order kinetics. The half-lives (mean) in the nasal, rectal and vaginal mucosal extracts were found to be 1.07, 0.33 and 1.14 hr for Leu-Enk, and 16.9, 6.2 and 6.8 hr for YAGFL, respectively. AM or PM, which is an aminopeptidase inhibitor, did not show a sufficient inhibition of Leu-Enk $(50\;{\mu}g/ml)$ degradation in all kinds of extracts. $Dimethyl-{\beta}-cyclodextrin\;(DM-{\beta}-CyD)$ decreased the degradation rate constants of Leu-Enk about 2 or 3 times, comparing with no additive. However, the use of mixed inhibitors of AM $(50\;{\mu}M)$/TM (0.25 mM)/EDTA (5 mM) resulted in a full stabilization of Leu-Enk by decreasing the degradation rate constants 67.3, 161.3 and 113.8 times far the nasal, rectal and vaginal mucosal extracts, respectively, comparing with no inhibitor. With mixed inhibitors, Leu-Enk remained intact more than 90% after 6 hr-incubation. In the stabilization of YAGFL, hM, TP or CPL alone showed little efffct, and some additives demonstrated a considerable inhibition of YAGFL degradation in the rank order of TM > BC > EDTA. However, the addition of mixed inhibitors such as TM (0.5 mM) and EDTA (5 mM) into the extracts protected YAGFL from the degradation by more than 85% even after 24 hr-incubation, suggesting almost complete inhibition of YAGFL degradation in the extract. On the other hand, $DM-{\beta}-CyD\;or\;hydroxypropyl-{\beta}-cyclodextrin$ (10%) were also found to retard enzymatic degradation rates of YAGFL markedly, and resulted in staying intact more than 80% of YAGFL in the nasal and vaginal mucosal extracts, and more than 60% in the rectal mucosal extract after 16 hr-incubation.

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Degradation and Stabilization of $[D-Ala^2]-Methionine$ Enkephalinamide in Various Rabbit Mucosa Extracts (토끼의 수종 점막 추출액중 $[D-Ala^2]-Methionine$ Enkephalinamide의 분해 및 안정화)

  • Chun, In-Koo;Yang, Yoon-Jeong
    • Journal of Pharmaceutical Investigation
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    • v.22 no.3
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    • pp.173-183
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    • 1992
  • To study the feasibility of transmucosal delivery of $[D-ala^2]-methionine$ enkephalinamide (YAGFM), its enzymatic degradation and stabilization in various rabbit mucosal extracts were investigated by HPLC method. The degradation of YAGFM was observed to follow the first-order kinetics and the half-lives of YAGFM in the nasal, rectal and vaginal mucosal extracts were found to be 25.7, 3.0 and 7.8 hr, respectively. However, there was no significant difference in degradation rates of YAGFM between the mucosal and serosal extracts obtained from the same mucosal membrane. This finding suggests that even a synthetic enkephalin analog, which is designed to be resistent to aminopeptidases, needs to be fully protected from the enzymatic degradation in mucosal sites for the delivery of the analog through mucosal routes. To inhibit the degradation of YAGFM in various mucosal extracts, effects of enzyme inhibitors such as bestatin (BS), amastatin (AM), thiorphan (TP), thimerosal (TM) and EDTA, alone or in combination, and modified cyclodextrins were observed by assaying YAGFM staying intact during 24 hr-incubation at $37^{\circ}C$. It was found from the results that mixed inhibitors such as TM (0.5 mM)/EDTA (5 mM) or AM $(50{\mu}M)/TM$ (0.5 mM)/EDTA (5 mM) provided very useful means for the stabilization in various mucosal extracts. The latter was found to protect YAGFM from the degradation in the nasal, rectal, and vaginal mucosal extracts by 90.9, 90.4 and 91.3%, respectively, after 24 hr-incubation, suggesting almost complete inhibition of YAGFM-degrading enzymes present in the incubation mixture. However, BS $(50{\mu}M)$, AM 50 $(50{\mu}M)$ or TP$(50{\mu}M)$ alone did not reveal sufficient inhibition except TM (0.5 mM) or EDTA (5 mM). The adddition of $2-hydroxylpropyl-{\beta}-cyclodextrin$(10%) to the nasal mucosal extract, and $dimethyl-{\beta}-cyclodextrin$(10%) to the rectal and vaginal mucosal extracts reduced the first-order rate constants for the degradation of YAGFM by 5.8, 17.3 and 8.9 times, respectively, compared to those with no additive.

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Bioequivalence Evaluation of Commercially Available Choline Magnesium Trisalicylate Tablets in Healthy Volunteers (건강한 지원자를 대상으로 한 시판 Choline Magnesium Trisalicylate 정제의 생물학적 동등성 평가)

  • Park, Kyoung-Ho;Shin, Hyon-Taek;Lee, Min-Hwa;Goh, Young-Yul
    • Journal of Pharmaceutical Investigation
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    • v.22 no.3
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    • pp.229-235
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    • 1992
  • The bioequivalence of two commercial choline magnesium trisalicylate (CMT) tablets was evaluated in 10 normal male subjects (age 21-27 yr, mean 23 yr) following single oral administrations of two products. Test product was $Trimax^{\circledR}$ tablet (Hyundai Pharm. Ind. Co., Ltd., Korea) and reference product was $Trilisate^{\circledR}$ tablet (Purdue Frederick, U.S.A.). Both products contained 500 mg salicylate. In the study, ten volunteers were administered one tablet of $Trimax^{\circledR}$ or $Trilisate^{\circledR}$ with randomized two period cross-over study. The pharmacokinetic parameters of two products were statistically compared using Student's t-test and ANOVA. When Student's t-test was applied, mean area under the curves (AUC) of $Trilisate^{\circledR}$ and $Trimax^{\circledR}$ were $388.88{\pm}74.99\; {\mu}g{\cdot}hr/ml$ and $390.63{\pm}63.02\;{\mu}g{\cdot}hr/ml$ hrlm!, respectively, which were not significantly different (p>0.05). The mean peak concentrations $(C_{max})$ and mean times to peak $(T_{max})$ of $Trilisate^{\circledR}$ and $Trimax^{\circledR}$ were $71.1{\pm}12.2$ and $72.9{\pm}10.7\;{\mu}g/ml$, and $72{\pm}33$ and $57{\pm}36min$, respectively, which were not significantly different (p>0.05). The mean terminal phase half-lives $(t_{l/2ter})$ of the two products were $2.57{\pm}0.47$ and $2.43{\pm}0.40$ hr, and also they were not significantly different (p>0.05). When ANOVA was applied, the parameters of the two products were not also significantly different each other. Based on the above results, it has been concluded that the bioavailability of $Trimax^{\circledR}$ tablet was not significantly different from that of $Trilisate^{\circledR}$ tablet.

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The Degradation Patterns of Two Pesticides in Spinach by Cultivation, Storage and Washing (시금치의 생육, 저장기간 및 세척에 따른 잔류농약 분해특성)

  • Seo, Jung-Mi;Ha, Dong-Ryong;Lee, Hyang-Hee;Oh, Mu-Sul;Park, Jong-Jin;Shin, Hyeon-Wo;Kim, Eun-Sun
    • Journal of Food Hygiene and Safety
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    • v.25 no.2
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    • pp.91-99
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    • 2010
  • Two pesticides commonly used in spinach were subjected to a field residue trial to ensure safety of terminal residues in the harvest. The residual patterns of two pesticides, which were Azoxystrobin and chlorpyrifos were examined after applying with the recommended dose and their $DT_{50}$ were calculated. Also degradation patterns of pesticides at storage $4^{\circ}C$ were compared to those at $20^{\circ}C$, and removal rates of pesticides by washing spinach with water were measured. Biological half-lives of azoxystrobin and chlorpyrifos were 3.2~3.8 and 3.8~4.7 days, respectively. During the storage period, the degradation patterns were appeared more obviously at $20^{\circ}C$ than $4^{\circ}C$. Removal rates of azoxystrobin and chlorpyrifos were 9.6~90.0% and 17.7~85.8% by various washing methods.

The Structure and The Reason for Nuclear Accumulation of Poly A(-) Spliced SV40 RNA (Poly A tail이 없는 SV 40 spliced RNA의 구조 및 핵내 축적의 원인)

  • 박주상;노정혜
    • Korean Journal of Microbiology
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    • v.27 no.1
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    • pp.1-9
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    • 1989
  • The locations of 5' ends as well as the splicing pattern of viral poly A(-) 19S RNA from monkey cells infected with SV40 were determined by a modification of primer extension method. The 5' end of this RNA mapped at the major cap site at nucleotide residue 325, used most frequently by SV40 late RNAs. The intron from nt.373 to nt.558 was removed as the ordinary cytoplasmic poly A(+) 19S RNA. The 3'end of this RNA was very heterogeneous and distributed over 1 kb upstream of polyadenylation site, as determined by S1 nuclease mapping. The reason for this normally initiated and spliced RNA to accumulate in the nucleus was investigated. In order to test whether the presence of unused 3' splice region on this RNA caused such subcellular distribution, cells were transfected with SV40 mutant KNA containing deletion around 3' splice site. The RNA deleted of 3' splice region accumulated mainly in the cytoplasm. This accumulation did not result from the increased stability of the RNA due to the deletion, since the wild type and mutant RNAs exhibited similar half lives after chase with actinomycin D. Therefore it is likely that the 19S spliced RNA is hindered from being transported into the cytoplasm due to some pre-splicing complexes formed at the unused 3' splice site.

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