• Journal of Radiation Protection and Research
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• 제28권2호
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• pp.145-154
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• 2003

By optimizing the radiation protection the collective dose and individual dose could be reduced during YGN #4 $5^{th}$ outage in 2001. The collective doses for the two high radiation jobs decreased to 85% and 65% of expected doses. The proportion of workers with low dose (below 1mSv) exposure increased 4% while the proportion of workers with over 3mSv and 5mSv exposure are decreased to 2%, 1% respectively. But none is exposed over 8mSv for the annual dose. To aid decision of utilizing the robot, cost- benefit analysis was performed and reasonable point was proposed to use the robot. For the first time job, repeated ALARA meeting and mock up training were implemented to set up working procedure by identifying the trouble. To easily set up standard procedure, mockup process was videotaped and reviewed during ALARA meeting. Monitoring is a good approach to chase radiological working condition such as working time, dose rate. behavior of workers, especially for high radiation work. Those data were estimated and adjusted from the stage of work planning to mock up. At the stage of actual work the monitoring data were compared to the estimation and recorded to database. This database will not only be used as a powerful tool for dose optimization at the following outage but also as a guideline to dose constraint set up for optimization for each specific situation.

• Nuclear Engineering and Technology
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• 제52권10호
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• pp.2334-2338
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• 2020

In recent years, 3D printing technology has received significant research attention. Additionally, 3D printing technology is being applied to study radiation dosimeters of various materials. In this study, a plastic scintillator for 3D printing was developed in a laboratory and used to manufacture a plastic scintillation dosimeter (PSD) with a shape identical to that of the ionization chamber PTW31010. The 16-mm beam of Gamma Knife® Perfexion™ was irradiated to derive the absorbed dose rates of the PSD and PTW31010; they were subsequently compared with the dose rates of the treatment plan. The differences in the dose rates of the Gamma Knife treatment plan and the absorbed dose rates of PTW31010 were within 0.87%. The difference between the dose rates of the Gamma Knife treatment plan and the absorbed dose rates of the PSD were within 4.1%. A linear fit of the absorbed dose rates of four shots involving different dose rates and irradiation angles yielded an adjusted R-square value exceeding 0.9999. A total of 10 repeated measurements were conducted for the same shot to confirm its reproducibility, with a relative error of 0.56%.

• Biomolecules & Therapeutics
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• 제2권3호
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• pp.270-280
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• 1994

This study was conducted to evaluate the repeated dose toxicity of DA-3030, a recombinant human granulocyte colony stimulating factor(rhG-CSF), in rats. DA-3030 was administered intravenously once a day for 4 weeks to 20 males and 20 females per group at doses of 0(control), 115 and 1150 $\mu\textrm{g}$/kg, and to 15 males and 15 females per group at doses of 1.15 and 11.5$\mu\textrm{g}$/kg. After the administration period, 5 males and 5 females per group in the 0,115 and 1150 $\mu\textrm{g}$/kg groups were placed on withdrawal for 2 weeks. Through-out the study, all the rats survived. The administration of DA-3030 induced, a marked increase in the number of peripheral neutrophils, elevation of serum alkaline phosphatase activity, and splenomegaly in the rats of both sexes receiving 115 or 1150 $\mu\textrm{g}$/kg. Histopathologic examination revealed extramedullary granulopoiesis in spleen and liver, and increase in the number of activated macrophages in spleen in rats of both sexes in 115 and 115 $\mu\textrm{g}$/kg groups, and increased M/E ratio in 11.5, 115 and 1150$\mu\textrm{g}$/kg groups. Most of the changes produced by DA-3030 were thought to be attributable to exaggerated pharmacological effect of the drug, and subsided or disappeared after the recovery period. Under the present condition, no effect dose of DA-3030 is estimated at 1.15 $\mu\textrm{g}$/kg/day.

• 한국식생활문화학회지
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• 제34권6호
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• pp.801-809
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• 2019

Abeliophyllum distichum Nakai is a deciduous shrub of a flowering plant in Oleaceae. It is an important plant resource and consists of only one species in the entire world. A. distichum Nakai is well known an edible, medicinal herb in its habitat districts, but the toxicological evaluation for the safe use of its extract is still insufficient. The study characterized the toxicity of an Abeliophyllum distichum Nakai ethanol extract in Sprague-Dawley (SD) rats and determined the safe dosage levels in a 13 weeks toxicity study. Abeliophyllum distichum Nakai ethanol extract was orally administered once daily for 2 weeks at 0, 500, 1,000 and 2,000 mg/kg/day to male and female SD rats. while recording the clinical signs of toxicity, body weight, food intake/consumption, eye test and urine analysis. Only the total protein frequency in the urine of male SD rats (p<0.05), the right ovary of the 500 mg/kg group (p<0.01) and the right adrenal gland of the 1,000 mg/kg group (p<0.05) in the female rats showed statistically significant changes. But no toxic effects were noted from repeated-dose administration of the Abeliophyllum distichum Nakai ethanol extract in the SD rats during the observation period. The post-mortem examinations showed no test substance-mediated changes. The hematological analysis and clinical blood chemistry data demonstrated no toxic effects from repeated-dose administration of Abeliophyllum distichum Nakai ethanol extract in the SD rats during the observation period. Based on these results, this data suggests that a dose of 1,000 mg/kg/day is a highest treatment to administer when conducting a further 13 weeks toxicity study.

• 한국산업보건학회지
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• 제23권1호
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• pp.1-10
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• 2013

Objectives: The present study investigated the potential subacute toxicity of 1,4-dichlorobutane (1,4-DCB) by a 2-week repeated oral dose in male Sprague-Dawley rats. Materials and Methods: The test chemical was administered once daily by gavage to male rats at dose levels of 0, 74, 222, 667, and 2000 mg/kg/day for 2 weeks. All rats were sacrificed at the end of treatment period. During the test period, clinical signs, mortality, body weights, food and water consumption, urinalysis, hematology, serum biochemistry, gross findings, and organ weights were examined. Results: At 2000 mg/kg/day, treatment-related clinical signs, as evidenced by hypothermia, decreased locomotor activity, piloerection, lying on side, and prone position were observed. All the rats were found dead on test day 2. At 667 mg/kg/day, polyuria, suppressed body weight gain, food consumption, and spleen and thymus weights, and increased adrenal gland and liver weights were observed.Hematological and serum biochemical investigations revealed increases in the alanine aminotransferase, alkaline phosphataseand total bilirubinand decreases in the serum $Na^+$ level, white blood cell count and lymphocyte ratio. There were no treatment-related adverse effects in the 74 and 222 mg/kg/day groups. Conclusions: In the present experimental conditions, target organs were determined to be spleen, thymus,and liver. The no-observed-adverse-effect level was considered to be 222 mg/kg/day in male rats.

• Journal of Applied Biological Chemistry
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• 제62권2호
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• pp.123-127
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• 2019

핑크왐피는 피부병, 말라리아, 복통, 이질 및 장염 치료를 위한 약용 식물로 사용되고 있다. 본 연구의 목적은 핑크왐피의 안전성을 확인하기 위하여, 수컷 ICR 마우스를 이용하여 핑크왐피를 3주 반복 경구 투여하여 최대무독성용량을 평가했다. 핑크왐피를 100, 250, 500, 1000, 및 2000 mg/kg으로 투여한 결과, 모든 시험물질 투여군에서 이상이 관찰되지 않았다. 사망률, 임상 증상, 체중 변화, 혈액 학적 검사 및 혈청 생화학 검사에서 유의적인 차이는 없었고, 경미한 변동은 핑크왐피의 투여로 인한 영향이 아닌 정상 범위 내에서의 변화로 간주 되어진다. 결과적으로, 핑크왐피는 모든 시험물질 투여군에서 독성 영향을 미치지 않았으며, 핑크왐피의 최대무독성용량은 2000 mg/kg 이상으로 간주되었다.

• 대한한의학방제학회지
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• 제31권4호
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• pp.327-339
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• 2023

Objectives : This study conducted a repeated dose 90-day oral toxicity test in order to up-cycling Schisandra fruit extract powder(SFEP) using discarded Schisandra chinensis by-products and evaluated the NOAEL of SFEP. Methods : SD-rats were orally administered SFEP at concentrations of 0, 62.5, 125, and 250 mg/kg once daily for 90 days. Body weights and clinical signs were observed during the administration period. After completion of the experiment, the experimental animals were autopsied to observe necropsy findings and organ weights changes, and hematological parameters and blood chemistry values were measured. Results : During the SFEP administration period, clinical signs such as salivation, wounds, and erosion were sporadically observed in 1 to 2 animals. In the SFEP 250 mg/kg administered group, weights of the liver and thyroid gland significantly increased compared to the control group, but no significant changes were observed in organ weights according to body weights. As a result of measuring hematological parameters and blood chemistry values, a decrease in RDW, T-BIL, and TBA, and an increase in TP, ALB, and Ca were observed due to SFEP administration. However, these changes following SFEP administration were accidental and not dose-dependent. Additionally, no correlation was found between gender and other parameters. Conclusions : Therefore, the NOAEL of SFEP was confirmed to be 250 mg/kg.

• 생명과학회지
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• 제26권10호
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• pp.1153-1162
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• 2016

계종버섯(Thermitomyces albuminosus)의 안정성을 입증하기 위하여 사료에 계종버섯의 분말을 5%, 2.5%, 1.25%, 0%를 혼합하여 90일 동안 랫드에 자유 급이 시켜 실험동물의 일반증상, 체중변화, 혈액학적 검사, 부검소견, 임상병리, 조직병리학적 검사의 결과를 토대로 독성을 평가하였다. 독성판정기준은 독성의 정도와 양상에 따라 weight-based classification (독성 강도에 따른 분류)로 분류 하였는데 비시험물질-유래 변화인 NOEL, 시험물질-유래 경미한 변화는 NOAEL, 시험물질-유래 중요한 변화는 LOAEL을 기준으로 나누었다. 시험결과, 수컷 좌, 우측 신장 중량이 용량의존적으로 증가하여 고용량군에서는 12%, 8% 증가 하였다. 하지만 임상, 조직병리학적 결과 독성으로 판단되는 소견이 관찰되지 않아 시험물질-유래 경미한 변화로 판단으로 분류하였다. 따라서 판정기준에 따라 수컷은 NOAEL 암컷은 NOEL이 식이함량 5%로 추정되지만 식약처고시에 따라 암수 모두 NOAEL이 식이함량의 5%로 추정할 수 있다. 따라서 계종버섯은 식품 또는 기능성식품으로의 개발에 문제가 없을 것으로 사료된다.

• 약학회지
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• 제43권2호
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• pp.180-197
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• 1999

Acute and subacute oral toxicity of $HELIKIT^{TM}$ ($^{13}C-urea$) were carried out in Sprague-Dawley rats of both sex. The toxicity of $HELIKIT^{TM}$ was compared with urea($^{12}C-urea$ which is used for control). In acute toxicity studies, we daily examined number of deaths, clinical signs, body weights and pathological examination for 14 days after single oral administration of HELIKIT or urea($^{12}C-urea$) at a dose of 5000 mg/kg. The subacute oral toxicity was investigated in Sprague-Dawley rats treated with $HELIKIT^{TM}$ at a dose of 40, 200 and 1,000 mg/kg/day or $^{12}C-urea$ at a dose of 1,000 mg/kg/day for 4 weeks. In acute toxicity studies, $HELIKIT^{TM}$ and urea did not show any toxic effect in rats and oral LD50 value was over 5,000 mg/kg rats. In subacute toxicity studies, no death occured and no drug-related changes were found in clinical observations; body weight, food consumption, opthalmoscopy. auditory test, urinalysis, hematology, blood chemistry, gross pathological examination or organ weight between $HELIKIT^{TM}$, urea and control groups. In histopathological examinations, the slight thickening of mucosa of the limiting ridge in the stomach was noted in the animals treated with $HELIKIT^{TM}$ at a dose of 1,000 mg/kg/day and also the changes in urea group at a dose of 1,000 mg/kg/day was found, but all of these changes in the changes in ures group at a dose of 1,000 mg/kg/days was found, but all of these changes in the stomach regressed after withdrawal of the test article for 2 weeks and reversibility of the effect was revealed. These results indicate that the non toxic dose level of $HELIKIT^{TM}$ was 1,000 mg/kg/day in the 4 weeks-repeated dose study, suggesting that the substitution of $^{13}C$ for carbon in urea molecule has no effect on the toxicity of urea and changes in stomach are reversible.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.301-301
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• 1994

〔$^3$H〕Ouabain binding parameters(K$\_$D/ and B$\_$max/,) in homogenates prepared fpom control rat ventricular strip and Langendorff preparations which were not previously exposed to ouabain were compared to those in homogenates from ventricular strip and Langendorff preparations that had been first exposed to a complete ouabain dose-response curve(10$\^$-7/M to 10$\^$-4/ M). In rat ventricular strips and Langendorff perfused rat heart preparations, cumulative dose-response cruves of ouabain revealed biphasic positive inotropic effects, a "low-dose" and a "high-dose" effect with ED$\_$50/ values of 0.5${\mu}$M and 35${\mu}$M ouabain, respectively- The "low-dose" effect in rat ventricular strips disappeared or was diminished significantly when the ouabain dose-response curve wag repeated after the washout of the effects of the first curve, whereas the maximal "high-dose" effect was identical in both exposures to oubain. However, there was no change in the "low-dose" effects in both sets of the Langendorff perfused hearts. The contractile activity of the pre-exposed strips did not indicate the presence of residual ouabain since their basal contractile force was decreased 10% compared to initial control. 〔$^3$H〕Ouabain binding parameters, K$\_$D/ and B$\_$max/, were not changed comparing homogenate of control ventricular strips with that of strips pre-exposed to ouabain. These results suggest that digitalis receptor desensitization in the rat ventricular strip may due to the change of post-receptor events induced by ouabain binding to a high affinity site(${\alpha}$$_2$ isoform).