• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.54-60
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• 1995

Medical Internal Radiation Dose(MIRD) schema was developed for calculating the absorbed dose from the administered radiopharmaceuticals. With the biological distribution data and the physical properties of the radionuclide we can estimate the absorbed dose by the MIRD schema. For the thyroid cancer patients received $^{131}I$ therapy, the absorbed dose to the bone marrow is the limiting factor to the administered dose, and the duration of admission is deter-mined by the retained activity in the whole body. To monitor the whole body radioactivity, we used Eberline Smart 200 system using ionization chamber as a detector. With the time activity curve of the whole body, total body residence time was obtained. From the ICRP publication 53, the residence times of the source organs, such as kidney, urinary bladder content and stomach, were used to calculate the absorbed doses of the target organs, such as stomach, red marrow, bladder wall and remaineder total body. In 8 thyroid cancer patients with 175 mci of $^{131}I$ administered orally, the mean absorbed dose in the bladder wall was 375.1, in the stomach 285.1, red marrow 25.4 and total body 22.4 rad respectively. For the monitoring of the large administered activity, this method seemed to be quite useful.

• The Korea Journal of Herbology
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• v.36 no.6
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• pp.27-37
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• 2021

Objectives : In the current study, we performed the 13-week repeated oral dose toxicity test and a 4-week recovery test of standardized Cornus officinalis Sieb. et Zucc. and Psoralea corylifolia L. 30 % ethanol extract (SCP) in Sprague-Dawley (SD) rats owing to aims for verifying no observed adverse effect level (NOAEL). Methods : The animal study was performed according to OECD guidelines for the testing of chemicals section 4 health effects test No.408 repeated dose 90-day oral toxicity study in rodents (03 October 2008). In the repeated dose toxicity study, SCP was orally administered to female and male rats at dose levels of 1,000, 2,000, and 4,000 mg/kg/day for 13-week. The control group and high dose (4,000 mg/kg/day) group were then monitored for 4 extra weeks to determine recovery time after the study period. 1) Results : Compared with the control group, there were no treatment-related adverse effects in clinical signs, body weight, hematology, serum biochemistry (Aspartate aminotransferase, Alanine aminotransferase, Alkaline phosphatase, 𝛾-Glutamyl transpeptidase, Blood urea nitrogen, Creatinine, Glucose, Total cholesterol, Total protein, Creatine phosphokinase, Albumin, Total bilirubin, Triglyceride, Inorganic phosphorus, Albumin/Globulin ratio, Calcium ion, Sodium ion, Potassium ion, Chloride ion), necropsy findings and organ weight (Ovary, Adrenal gland, Pituitary, Thymus, Prostate, Testis, Epididymis, Spleen, Kidney, Heart, Lung, Brain, Liver) at any dose tested. Conclusions : Taken together, these results suggest that the NOAEL of SCP in both genders was considered as over 4,000 mg/kg. Results from this study provide scientific evidence for the safety of SCP.

• Journal of Chest Surgery
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• v.24 no.3
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• pp.253-260
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• 1991

The adequacy of anticoagulation with heparin during cardiopulmonary bypass, and precise neutralization with protamine at the conclusion of cardiopulmonary bypass, were important. In sixty children undergoing cardiopulmonary bypass, ACT and heparin dose-response curve were studied. Total dose of heparin before bypass were 2.80$\pm$0.74 mg/kg and the amount of protamine administered after bypass were 3.0$\pm$1.23 mg/kg. So protamine: heparin ratio was 1.07: l.c After administration of protamine which dose is calculated with heparin dose-response curve, ACTs were returned to normal range[mean 114.8 $\pm$13 second]. The heparin sensitivity and its half-life do not have relationship with age, weight, height, surface area and urine amount during operation. And there are too much individual variations in heparin sensitivity and its half-life. So conventional heparin protocols can overestimate or underestimate the amount of heparin and protamine. Heparin dose-response curve makes it possible to maintain anticoagulation in a safe range during bypass with adequate amount of heparin individually. At the conclusion of bypass, this curve can be used to predict the precise amount of protamine amount of protamine needed for neutralization of the heparin. But heparin dose-response curve to be used clinically, further studies will be needed about relationship between ACT and heparin level in the high range, influence of hemodilution and hypothermia to ACT and discrepancy between true adequate amount of protamine and calculated amount by heparin dose-response curve.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1619-1626
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• 2017

Electronic components that are used in high-level radiation environment require a semiconductor device having a radiation-hardened characteristic. In this paper, we proposed a radiation-hardened I-gate n-MOSFET (n-type Metal Oxide Semiconductors Field Effect Transistors) using a layout modification technique only. The proposed I-gate n-MOSFET structure is modified as an I-shaped gate poly in order to mitigate a radiation-induced leakage current in the standard n-MOSFET structure. For verification of its radiation-hardened characteristic, the M&S (Modeling and Simulation) of the 3D (3-Dimension) structure is performed by TCAD (Technology Computer Aided Design) tool. In addition, we carried out an evaluation test using a $Co^{60}$ gamma-ray source of 10kGy(Si)/h. As a result, we have confirmed the radiation-hardened level up to a total ionizing dose of 20kGy(Si).

• Bulletin of the Korean Space Science Society
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• 2005.04a
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• pp.143-147
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• 2005

This paper describes the analysis of radiation environment and effects. TID(Total ionizing Dose) and SEE(Single Event Effects) analysis are implemented. The HAUSAT-2 is a 25kg class nanosatellite which is operated at sun-synchronous orbit at an altitude 650km. Trapped proton and Electron, Solar Proton, Galactic Cosmic Ray models are considered to HAUSAT-2 radiation environment model. Total Dose-depth curve provides TID degree and components are verified by DMBP method and Sectoring analysis. SEE are analysed with Radiation Test Report. Existing Radiation Test Reports are use to SEE analysis of HAUSAT-2.

• Environmental Analysis Health and Toxicology
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• v.18 no.4
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• pp.255-269
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• 2003

The objective of this study was to estimate human exposure to benzo (a)pyrene through multimedia/multi-pathway exposure scenario. The human exposure scenario for benzo(a)pyrene was consisted of 12 multiple exposure pathways, and the multipathway human exposure model based on this scenario constituted. In this study, the multipathway human exposure model was used to estimate the concentrations in the exposure contact media, human intake factors and lifetime average daily dose (LAD $D_{model}$) of benzo(a)pyrene in the environment. Sensitivity analysis was performed to identify the important parameters and Monte-Carlo simulation was undertaken to examine the uncertainty of the model. The total LAD $D_{model}$ was estimated to be 5.52${\times}$10$^{-7}$ mg/kg-day (2.06${\times}$10$^{-7}$ -8.65${\times}$10$^{-7}$ mg/kg-day) using the multipathway human exposure model. The inhalation dose accounted for 78% of the total LADD, whereas ingestion and dermal contact intake accounted for 20.2% and 1.8% of the total exposure, respectively. Based on the sensitivity analysis, the most significant contributing input parameter was benzo (a)pyrene concentration of ambient air. Consequently, exposure via inhalation in outdoor/indoor air was the highest compared with the exposure via other medium/pathways.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.732-736
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• 2009

Protons are irradiated into SOl wafers under total dose of 100 krad, 500 krad, 1 Mrad and 2 Mrad to analyze the irradiation effect. The electrical properties are analyzed by pseudo MOSFET technology after proton irradiation. The wafers are annealed to stabilize generated defects in a nitrogen atmosphere at $300^{\circ}C$ for 1 hour because proton irradiation induces a lot of unstable defects in the surface silicon film. Both negative and positive turn-on voltages are shifted to negative direction after the irradiation. The more proton total dose, the more turn on voltage shifts. It means that positive oxide trap charge is generated in the buried oxide(BOX). The minority carrier lifetime which is analyzed by the drain current transient characteristics decreases with the increase of proton total dose. The proton irradiation makes crystal defects in the silicon film, and consequently, the crystal defects reduce the carrier lifetime and mobility. As these results, it can be concluded that pseudo MOSFET is a useful technology for the analysis of irradiated SOI wafer.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1194-1203
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• 2021

Preparation of recipient stallions is critical step to produce donor spermatogonial stem cell (SSC) derived sperm using transplantation technique. This study was conducted to evaluate the effects of intravenous busulfan infusion on germ cell depletion, semen production, and libido in stallions. Six Thoroughbred stallions were separated into two treatment groups: 1) a multiple low-dose (2.5 mg/kg bw for the first 4 weeks and 5 mg/kg bw for the 5th week); and 2) control group treated with PBS. Testicular samples were obtained at 11 weeks and classified into three different patterns of spermatogenesis, such as normal, Sertoli cell only, and destroyed. Semen collection and libido experiments were performed 1 week before treatment, and 4 and 8 weeks after treatment. For the sperm analysis, total spermatozoa and motility were measured using a light microscope with a motility analyzing system. In the multiple low-dose group, the numbers of tubules categorized as Sertoli cell only were significantly higher than those in the control as well as the total population and total/progressive motility of sperm were significantly decreased 8 weeks after the start of the treatment. The sperm production and motility in the multiple low-dose group appears to be reduced, while libido was maintained. In conclusion, multiple administration of 2.5 mg/kg bw busulfan depletes endogenous germ cells in the stallion recipients for SSC transplantation.

• Journal of IKEEE
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• v.27 no.3
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• pp.303-307
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• 2023

In this paper, the creation of an Electron-Hole Pair due to Total Ionizing Dose (TID) effects inside the oxide of a Buried Channel Array Transistor (BCAT) device is induced, resulting in an increase in leakage current and threshold due to an increase in hole trap charge at the oxide interface. By comparing and simulating changes in voltage with the previously proposed Partial Isolation Buried Channel Array Transistor (Pi-BCAT) structure, the characteristics in leakage current and threshold voltage changed regardless of the increased oxide area of the Pi-BCAT device, compared to the asymmetrically doped BCAT structure. It shows superiority.

• Journal of Astronomy and Space Sciences
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• v.39 no.2
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• pp.51-57
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• 2022

Cosmic radiation exposure of the flight crews in Korea has been managed by Radiation Safety Management around Living Life Act under Nuclear Safety and Security Commission. However, the domestic flight crews are excluded from the Act because of relatively low route dose exposure compared to that of international flight crews. But we found that the accumulated total annual dose of domestic flight crews is far from negligible because of relatively long total flight time and too many flights. In this study, to suggest the necessity of management of domestic flight crews' radiation exposure, we statistically analyzed domestic flight crew's accumulative annual dose by using cosmic radiation estimation models of the Civil Aviation Research Institute (CARI)-6M, Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS), and Korean Radiation Exposure Assessment Model (KREAM) and compared with in-situ measurements of Liulin-6K LET spectrometer. As a result, the average exposure dose of domestic flight crews was found to be 0.5-0.8 mSv. We also expect that our result might provide the basis to include the domestic flight crews as radiation workers, not just international flight attendants.