• Korean Journal of Microbiology
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• v.26 no.1
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• pp.1-5
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• 1988

The esolation and characterization of a new type II restriction endounclease, BamI, from Bacellus macerans ATCC 8244 were described. BmaI endonuclease was partially purified by procedures of ammonium sulfate fractionation, DEAE-cellulose and phosphocellulose chromatographies. This enzume recognized one site on pBR322 DNA, two sites on Bluescribe DNA, three sites on $\lambda$DNA and no site on SV 40 DNA. The same cleavage patterns for vareius DNAs as PvuI indicated that BamI is an isoschisomer of PvuI whose recognition sequence is 5'-CGATCG-3'. The optimal pH for the BmaI endonuclease activity was about 7.0 and optimal NaCl concentration was about 100mM. Manganese ion could partially replace magnesium as a cofactor, but calcium could not at all.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.254-260
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• 2023

Skeletal metastases are common in patients suffering from various primary cancers. Radiopharmaceuticals are an effective option for bone pain palliation. In this work, the radiation absorbed dose of ¹⁷⁷Lu-EDTMP radiopharmaceutical was estimated for adult man based on biodistribution data in Wistar rats. The MIRD dose calculation method and the Sparks and Aydogan methodology were applied. The results shows that about 46% of injected activity is cumulated on the surface of the trabecular and cortical bones. Radiation absorbed doses of red bone marrow and osteogenic cells were estimated to about 1.1 and 6.2 mGy/MBq, respectively. The maximum administrated activity was obtained 27 MBq/kg of body weight with an effective dose of 0.23 mSv/MBq. The results were compared with other available data from literature. This study indicated that ¹⁷⁷Lu-EDTMP provides therapeutic efficacy for achieving bone pain palliation with low undesired dose to other normal organs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.3
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• pp.254-261
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• 2000

The present study has attempted to look into the mechanism of ras-induced carcinogenesis in a human epithelial cell system. Human epithelial cells immortalized with Ad12-SV40 hybrid virus were used to assess carcinogenic potential of the ras-oncogene. Cells transfected with pSV2-ras showed characteristics of cellular transformation. The transformation parameters such as cell density, soft-agar colony formation, and cell aggregation were significantly increased in the cells expressing ras oncoprotein. In addition, the duration required for the appearance of foci was shortened in the ras-transfected cells. Consistent with other reports, our results demonstrated an evidence that the ras-oncogene induced the cellular transformation of human epithelial cell system. When a high concentration of glucocorticoid was added into the media, transformation process was accelerated. It is speculated that glucocorticoid may provide an advantageous environment for the proliferation of the transformed cells. The induction of the intracellular free calcium concentrations following agonist treatment was significantly lower in the transformed cells than in the control cells. These effects were more manifested in the presence of extracellular cacium, indicating that the transformation process may alter the influx pathway of extracellular calcium. The induction of $IP_3$ following agonist treatment was also lower in the transformed cells than in the control cells. Thus, it is suggested that phospholipase C-coupled pathway was down-regulated in the process of the ras-induced transformation. While the levels of $TGF-{\beta}_1$ and PAI-2 mRNAs were decreased, the level of fibronectin mRNA was increased. The results indicate that mechanism of the ras-induced transformation may be associated with the altered expressions of growth regulatory factors. The present study demonstrates an evidence that the ras-induced cellular transformation may be associated with alteration of signal transduction and growth regulatory factors. The study will contribute to improve the understanding of molecular mechanism of epithelium-derived cancers including oral cancer.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.633-638
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• 2017

The amount of radioactive waste has been rapidly increased with development of radiation treatment in medical field. Recently, it has been a common practice to use I-131 for thyroid cancer, F-18 for PET/CT and Tc-99m for diagnosis of nuclear medicine. All the wastes concerned have been disposed of by means of the self-disposal method, for example incineration, after storage enough to decay less than clearance level. IAEA proposed criteria for clearance level of waste which depends on the individual ($10{\mu}Sv/y$) and collective dose (1 man-Sv/y), and concentration of each nuclide (IAEA Safety Series No 111-P-1.1, 1992 and IAEA RS-G-1.7, 2004). In this study, specific radioactivity of radioactive waste contaminated with Re-186 was measured to confirm whether it meets the clearance level. Re-186 has long half life of 3.8 days relatively and emits beta and gamma radiation, therefore it can be applied in treatment and imaging purposes. The specific radioactivity of contaminated gloves weared by radiation workers was measured by MCA(Multi-channel Analyzer) which was calibrated by reference materials in accordance with the measuring procedure. As a result, comparison evaluation of decay storage period between the half-life which was calculated by attenuation curve based on real measurement and physical half-life was considered, and it is showed that the physical half-life is longer than induced half-life. Therefore, the storage period of radioactive waste for self-disposal may be curtailed in case of application of induced half-life. The result of this study will be proposed as ISO standard.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1207-1213
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• 2005

In a search for bacteria capable of degrading styrene better than previously isolated strains, bacterium IS-3 was isolated from activated sludge and found to be most closely related to Pseudomonas sp. Styrene degradation by this strain was tested in liquid cultures and polyurethane-packed biofilters. In liquid cultures, the rate of styrene degradation by this bacterium increased from 24.93 to $76.53\;{\mu}mol\;g^{-1}\;DCW\;H^{-1}$ for an initial mass range from 8.7 to $34.8{\mu}mol$. The maximum styrene elimination capacity was 580-635 $g/m^{3}\cdot$h at a space velocity (SV) of 50-200/h. The critical elimination capacities guaranteeing $95\%$ removal of the input styrene were determined to be 635, 170, and 38 $g/m^{3}\cdot$h, respectively, at SVs of 50, 100, and 200/h. Kinetic analysis revealed that the maximum styrene elimination velocity ($V_{m}$) for this biofilter was 1,000 g/m$\cdot$h, and the saturation constant ($K_{m}$) was 454 ppmv. Together, these results suggest that a polyurethane biofilter containing Pseudomonas sp. IS-3 could have potential practical applications for the effective removal of styrene gas.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2182-2189
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• 2024

The high-purity germanium gamma-ray spectrometer was used to measure the radioisotope in surface water of lakes in a Chinee petroleum industrial area. 92 samples were collected from surface water of three lakes. Activity concentrations of ²³²Th, ²²⁶Ra and ⁴⁰K in three lakes were measured, distributed in the range of 101.8-209.4, 192.1-224.9 and 335.0-548.9 mBq/L, respectively. Results were all within the limits of WHO and China. Potential environmental and health risks were assessed by calculating some radiation hazard indicators, radium equivalent index, annual effective dose, excess lifetime cancer risk, absorbed dose rate, external hazard index, internal hazard index, annual gonadal dose equivalent, activity utilization index and representative gamma index, which ranged 0.38-0.54 Bq/L, 0.06-0.08 mSv/y, 0.23 × 10^-3-0.31 × 10^-3, 0.17-0.24 nGy/h, 1.01 × 10^-3-1.46 × 10^-3, 1.55 × 10^-3-2.02 × 10^-3, 1.16-1.66 μSv/y, 3.13 × 10^-3-4.45 × 10^-3 and 2.60 × 10^-3-3.77 × 10^-3. The results were all at acceptable levels, meaning no impact on human health. The relationship between the electrical conductivity of surface water and the activity concentration of ²³²Th, ²²⁶Ra and ⁴⁰K was evaluated. The electrical conductivity value was 0.241-0.369 mS/cm, showing a significant correlation coefficient between ²²⁶Ra and ⁴⁰K and electrical conductivity. Multivariate statistical methods were used to determine the relationship between the activity concentrations of ²³²Th, ²²⁶Ra, and ⁴⁰K, radiation hazard indicators and electrical conductivity.

• Journal of Radiation Protection and Research
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• v.32 no.4
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• pp.190-193
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• 2007

The objective of this study is to recommend the radiation protection design parameters from the shielding point of view for concrete wall between the decay tank room and the primary pump room in TRIGA Mark-II Research Reactor Facility. The shield design for this concrete wall has been performed with the help of Point-kernel Shielding Code Micro-Shield 5.05 and this design was also validated based on the measured dose rate values with Radiation Survey Meter (G-M Counter) considering the ICRP-60 (1990) recommendations for occupational dose rate limit ($10{\mu}Sv/hr$). The recommended shield design parameters are: (i) thickness of 114.3 cm Ilmenite-Magnetite Concrete (IMC) or 129.54 cm Ordinary Reinforced Concrete (ORC) for concrete wall A (ii) thickness of 66.04 cm Ilmenite-Magnetite Concrete (IMC) or 78.74 cm Ordinary Reinforced Concrete (ORC) for concrete wall B and (iii) door thickness of 3.175 cm Mild Steel (MS) on the entrance of decay tank room. In shielding efficiency analysis, the use of I-M concrete in the design of this concrete wall shows that it reduced the dose rate by a factor of at least 3.52 times approximately compared to ordinary reinforced concrete.

• The Journal of the Korea Contents Association
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• v.13 no.6
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• pp.331-338
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• 2013

CT for follow-up visits because of liver disease, body mass index (BMI) and kVp according to the change of the image quality and radiation dose to evaluate for changes. March 2010 to June 2011 at Pusan P University Hospital, abdominal CT scans a patient BMI (Body Mass Index. Less BMI) index was less than 25 in the treatment of subjects had a 48-person Noise and SNR at 100kVp abdominal image is lager than the 120kVp image. CTDI volume value at by the analysis of the radiation dose is 4.47mGy(100kVp) and 9.01mGy(120kVp). So CTDIvol in 100kVp is smaller than CTDIvol in 120kVp(decrease by 44.1%). And, effective dose is 7.1mSv(100kVp) and 12.51mSv(120kVp). So effective dose in 100kVp is smaller than effective dose in 120kVp(decrease by 43%). Evaluation of image quality is that Unacceptable 0 person, Suboptimal 0 person, Adequate 0 person, Good 1 person, Excellent 47 person. In case of repeatly patient, we examinate abdomianl CT scan by using low kVp and body mass index less than 25. We can has good quality image and benefit of low radiation dose.

• Journal of Radiation Protection and Research
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• v.24 no.3
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• pp.131-142
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• 1999

By using the Korean demographic data and the modified relative risk projection model given in the Committee on the Biological Effect of Ionizing Radiation (BEIR) report-V under the U.S. National Academy of Science, the radiogenic excess risk in Korean population has been evaluated. On the basis of this risk, a safety goal for the safe operation of domestic nuclear power plants has been further derived in terms of personal dose. The baseline risk of death due to all causes in Korea and the trivial risk level, which the society considers safe, were estimated to be $5.2{\times}10^{-3}$ and $5.2{\times}10^{-6}$, respectively. The radiogenic excess cancer risk in Korea has been estimated to be $5.2{\times}10^{-3}$ for tie case of acute exposure to 0.1 Gy and $3.7{\times}10^{-3}$ for the case of chronic lifetime exposure to 1.0 mGy/y. On the basis of these risks estimate, the resulting safety goal for one year opeation of a reactor was 0.05 mSv, which is quite identical with the ALARA guideline prescribed by the USNRC in the Appendix I, 10CFR50.

• Journal of Radiation Industry
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• v.9 no.4
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• pp.209-216
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• 2015

It has been about 5 years since the Fukushima nuclear power plant accident, which contaminated large area with radioactive materials. It is necessary to assess radiation dose to establish evacuation areas and to set decontamination goal for the large contaminated area. In this study, we assessed temporal trend of radiation dose to the public living in the large area contaminated with radioactive materials after the Fukushima nuclear power plant accident. The dose assessment was performed based on Chernobyl model and RESRAD model for two evacuation lift areas, Kawauchi and Naraha. It was reported that deposition densities in the areas were $4.3{\sim}96kBq\;m^{-2}$ for $^{134}Cs$, $1.4{\sim}300kBq\;m^{-2}$ for $^{137}Cs$, respectively. Radiation dose to the residents depended on radioactive cesium concentrations in the soil, ranging $0.11{\sim}2.4mSv\;y^{-1}$ at Kawauchi area and $0.69{\sim}1.1mSv\;y^{-1}$ at Naraha area in July 2014. The difference was less than 5% in radiation doses estimated by two different models. Radiation dose decreased with calendar time and the decreasing slope varied depending on dose assessment models. Based on the Chernobyl dosimetry model, radiation doses decreased with calendar time to about 65% level of the radiation dose in 2014 after 1 year, 11% level after 10 years, and 5.6% level after 30 years. RESRAD dosimetry model more slowly decreased radiation dose with time to about 85% level after 1 year, 40% level after 10 years, and 15% level after 30 years. The decrease of radiation dose can be mainly attributed into radioactive decays and environmental transport of the radioactive cesium. Only environmental transports of radioactive cesium without consideration of radioactive decays decreased radiation dose additionally 43% after 1 year, 72% after 3 years, 80% after 10 years, and 83% after 30 years. Radiation doses estimated with cesium concentration in the soil based on Chernobyl dosimetry model were compared with directly measured radiation doses. The estimated doses well agreed with the measurement data. This study results can be applied to radiation dose assessments at the contaminated area for radiation safety assurance or emergency preparedness.