• 한국환경농학회지
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• 제34권1호
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• pp.1-5
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• 2015

BACKGROUND: The stabilities of the two alkaloidal insecticides of S. flavescens including matrine and oxymatrine are important factor to establish expiry date and usage manual for crop protection. However, the environmental stability of the compounds had not been studied with the extract and its commercial biopesticide. METHODS AND RESULTS: The environmental stabilities of the two alkaloids were performed with extract of S. flavescens, and its two commercial biopesticides both in controlled aquatic and soil conditions. The half-lives of the total matrines for the extract and its two commercial biopesticides were estimated over 200 days both under aerobic and anaerobic water condition. Under dry soil condition, the initial decay rates of the matrines were calculated 0.0804-0.1275 ($t_{1/2}$ 5.4-8.6 days), and the half-lives under wet soil condition were calculated 33.0-231 days. Total soil bacteria on the wet soil ranged 6.0-8.0 log CFU/g-soil during the experiments period. CONCLUSION: The aquatic mixture of the extract showed excellent stability both with the extract and its biopesticides, however, the stability of soil mixture were shorter than the aquatic mixture, suggesting that soil metal consider as a catalyst for the degradation of the two alkaloids.

• Biomolecules & Therapeutics
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• 제2권4호
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• pp.310-315
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• 1994

The pharmacokinetics and tissue distribution of DA-3030 (recombinant human granulocyte colony-stimulating factor, rhG-CSF, recently manufactured by Dong-A research laboratory of Dong-A Pharmaceutical Company) were compared with reported data in the literature. After intravenous(i.v.) administration of DA-3030, at dose of 5, 10 and 100 $\mu\textrm{g}$/kg to rats, some pharmacokinetic parameters, such as terminal half-lives(1.05, 1.19 and 1.83 hr, respectively) and clearance (84.0, 54.8 and 45.5 mι/hr/kg, repectively), were dose-dependent. This could be due to the saturable metabolism of DA-3030 in rats. Similar results were also reported. After subcutaneous(s.c.) and intramuscular(i.m.) administrations of DA-3030, 10 $\mu\textrm{g}$/kg to rats, the extent of bioavailability(absolute bioavailability) were incomplete; the values were 23.3 and 18.2% after s.c. and i.m. injections, respectively, due to the degradation of DA-3030 by protease. After 7-consecutive day i.v. administrations of DA-3030, 10 $\mu\textrm{g}$/kg/day, to rats, the plasma concentrations and pharmacokinetic parameters of DA-3030 were not significantly different from those in single administration. In mice and dogs at DA-3030 dose of 10 $\mu\textrm{g}$/kg, the plasma concentrations of DA-3030 were also declined rapidly with terminal half-lives of 1.31 and 1.15 hr, respectively. DA-3030 was highly concentrated in the kidney after i.v. administration of DA-3030, 10 $\mu\textrm{g}$/kg, to rats, and the results were similar to those obtained using radiolabelled rhG-CSF in the literature. Above data indicate that DA-3030 has similar properties to rhG-CSF manufactured by other companies in view of pharmacokinetics.

• 대한치과의사협회지
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• 제57권10호
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• pp.613-622
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• 2019

The vitamin K antagonist (VKA), cumadin, or warfarin, is the only antithrombotic drug that can be orally administered and has excellent effective for decades. However, it is cumbersome to periodically inspect the prothrombin time (PT) order to maintain adequate concentrations that do not cause bleeding, takes a few days to indicate therapeutic effects, gets affected by several factors such as food and drugs etc, and narrow in the therapeutic range. Although recently in development, the non-vitamin K antagonist anticoagulants(NOACs) exhibit a rapid onset of action and have relatively short half- lives compared to Coumadin. Because of these pharmacokinetic properties, it is possible to modify an individual's anticoagulation status quite rapidly, minimizing the period where the anticoagulation activity is therapeutically suboptimal. And the short half -lives of these drug allow for the relatively rapid reduction of their anticoagulation effects. There are currently no published clinical trials specifically assessing the bleeding risks associated with dental procedures for patients taking the NOACs. It is not necessary to interrupt NOAC medication for dental procedures that are likely to cause bleeding, but which have a low risk of bleeding complications. Because the bleeding risk for these procedures is considered to be low, the balance of effects is in favour of continuing the NOAC treatment without modification, to avoid increasing the risk of a thromboembolic event. The patients should be advised to miss(apixaban or dabigatran) or delay(rivaroxaban) a dose of their NOAC prior to dental procedures that are likely to cause bleeding and which have a higher risk of bleeding complications. Because the risk of bleeding complications for these procedures is considered to be higher, the balance effects is in favour of missing or delaying the pretreatment NOAC dose. The interruption is only for a short time to minimize the effect on thromboembolic risk.

• 한국의학물리학회지:의학물리
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• 제32권4호
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• pp.145-152
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• 2021

Purpose: During the treatments of cancer patients with a linear accelerator (LINAC) using photon beams with energies ≥8 MV, the components inside the LINAC head get activated through the interaction of photonuclear reaction (γ, n) and neutron capture (n, γ). We used spectroscopy and measured the dose rate for the LINAC in operation after the treatment ended. Methods: We performed spectroscopy and dose rate measurements for three units of LINACs with a portable high-purity Germanium (HPGe) detector and a survey meter. The spectra were obtained after the beams were turned off. Spectroscopy was conducted for 3,600 seconds, and the dose rate was measured three times. We identified the radionuclides for each LINAC. Results: According to gamma spectroscopy results, most of the nuclides were short-lived radionuclides with half-lives of 100 days, except for ⁶⁰Co, ⁶⁵Zn, and ¹⁸¹W nuclides. The dose rate for three LINACs obtained immediately in front of the crosshair was in the range of 0.113 to 0.129 µSv/h. The maximum and minimum dose rates measured on weekends were 0.097 µSv/h and 0.092 µSv/h, respectively. Compared with the differences in weekday data, there was no significant difference between the data measured on Saturday and Sunday. Conclusions: Most of the detected radionuclides had half-lives <100 days, and the dose rate decreased rapidly. For equipment that primarily used energies ≤10 MV, when the equipment was transferred after at least 10 minutes after shutting it down, it is expected that there will be little effect on the workers' exposure.

• 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.

• 한국환경농학회지
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• 제22권3호
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• pp.220-226
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• 2003

복숭아의 생산단계에서 잔류허용 기준과 최종 소비단계에서의 잔류양상 평가자료로 활용하기 위하여 복숭아에서의 procymidone, chlorfyrifos 및 ccypermethrin의 포장상태에서와 실온($20^{\circ}C$) 및 저온($4^{\circ}C$) 저장시 잔류양상을 알아보았다. Procymidone의 포장상태에서의 반감기는 표준량 3.1, 배량 3.4일로 나타났고, chlorpyrifos는 포장상태에서 표준량 7.2, 배량 5.8일로 나타났으며, cypermethrin은 표준 10.1, 배량 14.4일로 나타났다. 약제 살포 후 초기 부착량이 MRL 이하로 내려갈 때까지의 시간을 계산해 본 결과 배량으로 살포 할 경우 procymidone과 chlorpyrifos는 안전사용기준 보다 시간이 오래 걸렸지만, 표준량으로 사용할 경우 별다른 문제가 없는 것으로 나타났다. 저장기간 중의 procymidone, chlorpyrifos, cypermethrin의 반감일수는 $20^{\circ}C$에서 4.6, 10.2, 12.9일 이며, $4^{\circ}C$에서는 16.1, 14.3, 13.1일로 저온에서의 반감기가 실온에서보다 더 긴 것을 알 수 있었다. 한편 세척방법에 의한 잔류농약의 제거율은 수돗물에서는 최고 procymidone 82.9%, chlorpyrifos 27.0%, cypermethrin 24.0%로 나타났고, 세제를 사용 할 경우 procymidone 88.8%, chlorpyrifos 59.0%, cypermethrin 59.4%의 제거율을 보였다.

• Applied Biological Chemistry
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• 제47권1호
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• pp.113-119
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• 2004

시설재배 고추중 tiazole계 살균제 bitertanol과 tebuconazole에 대하여 안전사용기준의 추천량과 배량을 포장에 살포 후 잔류농약의 감소양상을 조사하였다. 고추중 bitertanol의 반감기는 $5.2{\sim}6.1$일 이었고, tebuconazole은 $4.6{\sim}5.2$일로 나타났다. 고추잎에서의 반감기는 bitertanol은 $19.1{\sim}22.5$일 이었고, tebuconazole은 $16.7{\sim}20.8$일로 나타나 고추에 비해 반감일수가 $3{\sim}5$배 증가하였다. 고추잎에서 약제살포 24일 경과후 bitertanol과 tebuconazole의 잔류량은 10.1 mg/kg, 17.5 mg/kg으로 나타났는데, 이는 고추잎에 대한 Maximum Residue Limit(MRL) 3.0 mg/kg, 5.0 mg/kg을 크게 넘는 수치로 조사되었다. 시설재배 고추와 고추잎에서의 경시변화는 1차 회귀방정식에 부합하였으며, 고추잎에서의 엽면잔류량(Dislodgeable Foliar Residues, DFRs)은 24일 경과후 각각 36%, 48%가 소실되는 것으로 나타났다. 세척방법에 의한 잔류농약의 감소량을 조사한 결과 세제 사용시의 평균제거율을 bitertanol은 72.4%, tebuconazole은 72.2%로 나타났고, 일반 수돗물 사용시에는 bitertanol 60.3%, tebuconazole 61.5%로 나타났다.

• 한국잡초학회지
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• 제14권4호
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• pp.298-313
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• 1994

잔효기간이 긴 것으로 알려진 토양처리형 제초제 napropamide를 밭토양중 여러 환경조전하에 처리하여 이 약제의 토양중 분해성을 검토하고, 이 제초제가 토양미생물 상변화에 끼치는 영향에 대하여 실험을 실시한 결과는 다음과 같다. 살균토양과 비살균토양에서의 napropamide의 분해반감기는 각각 28.3, 14.6 일이었다. 수분함량의 차이에 따른 napropamide의 분해 속도는 60% > 80% ${\geq}$ 40% 순이였으며 napropamide의 처리와 무처리간의 미생물 발생수는 유의성이 없었고, 처리구내의 60% 수분함량구가 40% 수분함량구에서보다 세균수와 총균수가 많았다. pH의 차이에 따른 napropamide의 분해속도는 pH가 낮을수록 빨랐으며, napropamide처리구내 총균수는 pH5.5에서 경시적으로 증가하는 경향을 보였다. Napropamide의 분해속도는 $27^{\circ}C$ > $37^{\circ}C$ > $17^{\circ}C$의 순으로 빨랐으며, 각 온도에 있어서 napropamide 무처리구와 처리구간의 미생물수는 $17^{\circ}C$에선 방선균이, $27^{\circ}C$, $37^{\circ}C$에선 세균이 무처리구보다 처리구에서 증가됨을 알 수 있었다. Napropamide의 반감기는 10ppm과 20ppm처리에서 각각 16.6일과 21.1일이었고, 미생물 발생수는 20ppm처리구에서보다 10ppm처리구에서 많았다. 식양토와 미사질 양토에서 napropamide의 반감기는 27.7일, 17일이었으며, 처리구와 무처리구간의 미생물 발생수는 차이가 없었다. 포장 및 실내조건에서의 napropamide의 반감기는 각각 5.4일과 19.1일로 포장에서가 실내에서 보다 분해속도가 3.5배 빨랐다.

• 한국식품과학회지
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• 제33권6호
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• pp.664-668
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• 2001

전통 천연 색소원인 홍화 꽃잎으로부터 추출한 적색소인 carthamin을 식품색소로 활용하기 위한 기초연구로 carthamin의 여러 가지 이화학적 안정성을 분해속도와 반감기를 구하여 조사하였다. Carthamin은 산성에서는 매우 불안정하여 반감기가 pH 3.0에서는 5.26시간, pH 5.0에서는 4.9시간으로 매우 짧았으며 중성(pH 7.0)에서는 11.1시간, 알칼리 조건(pH 11.0)에서는 45.1시간으로 조금 더 안정했으나 적색에서 각각 주황색과 노란색으로 변화하였다. 온도가 증가함에 따라 색소 분해속도가 급격히 증가하였다. 많은 식품들이 약산성이므로 첨가물에 의한 안정성은 pH 5.0과 3.0에서 조사하였는데 무기이온들을 첨가하였을 때 큰 변화는 없었으나 $Al^{3+}$ 첨가 후에 농색화 현상과 함께 분해속도가 감소하여 안정화효과를 나타내었다. 빛에 의해(20,000 lux) 색소 분해가 촉진되어 대조구에 비해 2-3배 단축된 반감기를 나타내었다. 단당류와 이당류에 의해서는 변화가 거의 없었고 다당류를 첨가한 경우 약간의 안정화 효과가 관찰되었으며, 특히 CMC(carboxymethylcellulose)에 의해 pH 5.0의 조건에서 증가된 반감기를 나타내어 앞으로의 안정화 기술 개발의 가능성을 보여주었다.

• 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.