• Journal of Applied Biological Chemistry
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• 제62권4호
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• pp.407-415
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• 2019

들깻잎에 살포된 triazole계 살균제 6종에 대하여 생물학적 반감기를 산출하고 분해 및 소실 속도를 확인하였으며, 통계분석으로 생물학적 반감기와 농약의 물리화학적 특성간의 상관관계를 확인하였다. 확립된 분석법으로 6종 농약의 회수율 시험 결과 84.8-104.9%로 잔류농약분석법 기준을 만족하였다. 들깻잎에 살포한 농약 6종의 생물학적 반감기는 first-order kinetics model으로 산출하였으며, 그 결과 6.4-15.1일로 나타났다. 산출된 생물학적 반감기와 6종의 농약의 물리화학적 특성을 주성분 분석으로 상관성을 확인하였을 때, pKa, Log P 및 생물학적 반감기가 PC1에 영향을 받아 상관성이 있는 것으로 나타났다. Spearman rank-order correlation으로 생물학적 반감기와 물리화학적 특성간의 상관계수를 산출하였을 때, 생물학적 반감기와 pKa는 R² = -0.928, p <0.01로 나타나, 생물학적 반감기는 pKa와 상관성이 있는 것으로 나타났다.

• Journal of Radiation Protection and Research
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• 제26권3호
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• pp.139-142
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• 2001

The one of important parameter involved in the calculation of internal radiation dose to the human body is the biological half-life of the radionuclide. The biological half-life is population specific and may differ from one population group to another. So the effective half-life of tritium exposure based on urinal bioassay measurement of Wolsong Nuclear Power Plants was investigated and studied.

• 한국환경농학회지
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• 제28권4호
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• pp.419-426
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• 2009

This study was conducted to know the biological half-lives and dissipation patterns of fungicides, pyrimethanil, chlorothalonil and tetraconazole in Korean melon under green house condition. The instrument for analyzing pyrimethanil and chlorothalonil was HPLC equipped with UV detector. Initial residue amounts of pyrimethanil were 0.16 mg/kg at recommended rate and 0.28 mg/kg at double recommended rate in Korean melon. The biological half-lives of pyrimethanil were 11.2 days at recommended rate and 10.1 days at double recommended rate in Korean melon. In case of chlorothalonil, initial residue amounts of chlorothalonil were 0.06 mg/kg at recommended and 0.11 mg/kg at double recommended rate in Korean melon. The biological half-lives of chlorothalonil in Korean melon were 3.4 days at recommended rate and 6.6 days at double recommended rate. The instrument for analyzing tetraconazole was GLC equipped with electron capture detector. Initial residue amounts of tetraconazole were 0.14 mg/kg at recommended and 0.22 mg/kg at double recommended rate in Korean melon, respectively. The biological half-lives of tetraconazole were 9.6 days at recommended rate and 18.5 days at double recommended rate in Korean melon.

• 한국산업보건학회지
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• 제11권1호
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• pp.9-16
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• 2001

Chromium exposure can be in the forms of environmental pollution and occupational exposure. The harmful effects of chromium on the body greatly differ depending on its valence or solubility. Accordingly, the recommended permissible exposure limit for each chromium compound is different. This study investigated the increase or decrease of distribution and excretion of total chromium exposed simultaneously the soluble Cr+6 and Cr+3 compounds. There were no difference of total chromium concentration in plasma, red bloods cells, urine, organs between simultaneously injected and individually injected soluble Cr+6 and Cr+3 compound. The chromium clearances in urine also showed that there were two phases in the two groups. In the first phase, biological half lives of the total chromium of the two groups have been similar within 24 hr., but in the second phase, biological half life of the group injected simultaneously was 62.7 hr. and was less than that of the other group's 188.3 hr. The average concentration of total chromium in plasma was same with the control, and that of RBCs was $0.218nmol/m{\ell}$ and was slightly increased in comparison with $0.121nmol/m{\ell}$ of the control, which was not statistically significant. As a result, there were no differences of distribution and excretion of chromium between the group exposed simultaneously and the other group exposed separately the soluble Cr+6 and Cr+3 compounds. The biological half life of chromium of the former group in urine was less than that of the other group.

• Journal of Applied Biological Chemistry
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• 제55권4호
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• pp.235-239
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• 2012

사과에 대한 diniconazole과 metconazole의 반감기와 잔류양상을 조사하였다. Diniconazole과 metconazole의 잔류허용기준은 둘 다 1.0 mg/kg으로서 0일차 기준량과 3회 처리구 모두 잔류 허용기준을 넘지 않았다. 재배기간 중 사과의 잔류농도는 약제살포 후 14일 경과 시 diniconazole은 기준량 및 3회 처리에서 0.01 및 0.02 mg/kg으로서 각각 88.9 및 93.8%의 농약이 분해되었다. Metconazole은 각각 0.04 및 0.11 mg/kg으로서 60.0 및 56.0% 정도의 농약 분해율을 보였다. Diniconazole의 사과중 반감기식은 기중량 처리구에서 y=$0.0811e^{-0.179x}$ ($r^2$=0.9693), 3회 처리구에서 y=$0.1451e^{-0.148x}$ ($r^2$=0.9677)이었으며 생물학적 반감기는 각각 3.9일 및 4.7일 이었다. Metconazole의 반감기식은 y=$0.0857e^{-0.055x}$ ($r^2$=0.9242) 및 y=$0.2304e^{-0.052x}$ ($r^2$=0.9544)이었고 생물학적인 반감기는 각각 12.6일 및 13.3일 이었다. Metconazole 기준량과 3회 처리의 경우 first order kinetic model 보다는 second order kinetic mode이 더 적합하였으며 반감기도 기준량에서 2일, 3회 처리에서 1일 감소되는 것을 알 수 있었다. 따라서 각 농약별로 잔류량과 시간과의 관계에 적합한 model을 찾아 반감기를 산출하는 것이 바람직 할 것으로 생각된다.

• Journal of Pharmaceutical Investigation
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• 제16권4호
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• pp.152-157
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• 1986

The pharmacokinetics of sulfamethoxazole were investigated in rabbits with folate-induced renal failure. The blood level, area under the blood concentration curve (AUC) and biological half-life were increased significantly, and the urinary excretion was decreased significantly compared with those of normal rabbits. Correlation of serum creatinine concentration and AUC, biological half-life, and correlation of creatinine clearance and renal clearance have linear relationship respectively. From these results, dosage regimen of sulfamethoxazole is considered to be adjusted for effective and safe therapy in renal failure.

• Bulletin of the Korean Chemical Society
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• 제6권4호
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• pp.210-214
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• 1985

Urokinase, a plasminogen activator, was conjugated with dextran by the cyanogen bromide activation-coupling method. The resulting water-soluble conjugate was purified by gel permeation chromatography on Sephadex G-200. The maximal activity was obtained when the ratio of urokinase/dextran was 1/20 for the coupling. The final preparation showed 5 CTA units/mg conjugate, 300 CTA units/mg protein, 8.4 % activity retention, and 47 % protein retention. The urokinase-dextran conjugate had good thermal, pH and storage stabilities. In addition, it showed greater resistance to the inhibitory effect of human plasma than native urokinase. Also in vitro biological half-life of urokinase increased 40 times by this conjugation. In view of activity, excellent stability and increased half-life, the conjugate can be a potential fibrinolytic agent in an injectable form.

• 한국환경농학회지
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• 제37권3호
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• pp.213-220
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• 2018

BACKGROUND: This study was carried out to determine characteristics of residual pesticides in time-dependent manner and calculate half-lives of the residual pesticides in fresh and dried Chinese matrimony vine. In addition, processing factors were calculated based on the residual concentrations in them. METHODS AND RESULTS: The test pesticides, etofenprox and fenitrothion, were sprayed onto the Chinese matrimony vine plants at once or twice (at seven-day interval) and then samples were collected at 0 (after 3 hours), 1, 3, 5 and 7 days after the last spraying. Dried samples were prepared in hot-air drying oven at $60^{\circ}C$ for 48 hours until water content of less than 20%. Residual concentrations of etofenprox in fresh and dried samples decreased by 54.0-60.9% after 7 days of the last pesticide-application. In case of fenitrothion, the concentrations were found to have decreased by 69.2-76.5%. Processing factors of etofenprox were 2.6-3.0 for the one-time spraying and 2.5-3.0 for the two-time spraying and those of fenitrothion were found to be 1.5-22 for the one-time spraying and 1.6-2.0 for the two-time spraying. First half-lives of etofenprox and fenitrothion in fresh and dried samples ranged from 5.0 to 6.3 and from 3.4 to 4.0 days, respectively. The third half-lives were found to be 15.0-18.9 and 10.2-12.1 days, respectively. CONCLUSION: Residual concentrations of the tested pesticides in the studied crop decreased, but those in the dried samples appeared to have increased. In addition, processing factor and half life were constant regardless of spraying times.

• 대한방사성의약품학회지
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• 제1권1호
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• pp.1-8
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• 2015

It is essential use of long term half life radioisotopes for positron emission tomography (PET) imaging study of biopharmaceuticals because most of biopharmaceuticals have long biological half-life. Some representative isotopes are $^{124}I$, $^{64}Cu$, $^{89}Zr$ and so on. These PET radioisotopes and their radiopharmaceuticals have recently received growing interest because of long half life and good imaging properties. Furthermore, $^{64}Cu$ and $^{89}Zr$ can be used in a number of radiopharmaceuticals due to its ease of conjugation to peptides and antibodies using the proper chelator. In recent years, since $^{124}I$ was first developed in 2005, we have been studied to develop an efficient method and procedure for producing these radioisotopes, and we have made considerable progress in production of long term half life radioisotopes. This review introduces the general production system, purification procedure, and several advances on targeting method for $^{124}I$ and $^{64}Cu$ in KIRAMS.

• 한국환경농학회지
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• 제28권3호
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• pp.281-288
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• 2009

Azoxystrobin과 kresoxim-methyl의 참외 중 반감기와 잔류양상을 조사하였다. Azoxystrobin의 참외 중 0일차 잔류량은 기준량 및 배량 처리구에서 각각 0.09 및 0.14 mg/kg으로 나타났으며 농약의 반감기 소실곡선식은 y=0.0766e$^{-0.138x}$ ($r^2$=0.9424) 및 y=0.1143e$^{-0.0890x}$ ($r^2$=0.9310) 이었으며 생물학적 반감기는 각각 5.0일 및 7.8일 이었다. Kresoxim-methyl의 참외 중 0일차 잔류량은 기준량 및 배량 처리구에서 각각 0.10 및 0.23 mg/kg으로 나타났으며 농약의 소실곡선식은 y=0.0896e$^{-0.1672x}$ ($r^2$=0.9428) 및 y=0.1504e$^{-0.1446x}$ ($r^2$=0.9040) 이었고 생물학적인 반감기는 각각 4.1일 및 4.8일 이었다. 재배기간 중 참외의 무게증가에 농약희석효과를 배제한 절대잔류농도는 약제 살포 후 14일 경과시 azoxystrobin은 기준량 및 배량에서 0.01 및 0.05 mg/kg으로서 각각 83.6 및 67%의 농약이 분해되었다. Kresoxim-methyl은 각각 0.01 및 0.03 mg/kg 으로서 86.2 및 87.8% 정도의 농약 분해율을 보였다.