• Analytical Science and Technology
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• v.30 no.5
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• pp.252-261
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• 2017

Naturally occurring radioactive materials (NORMs) increase radiation exposure to the public as these materials are concentrated through artificial manufacturing processes by human activities. This study focuses on the development of a method for the quantitative analysis of $^{232}Th$, $^{235}U$, and $^{238}U$ in building materials. The accuracy and precision of inductively coupled plasma mass spectrometry (ICP-MS) for determination of digestion processes was evaluated for certified reference materials (CRMs) digested using various mixed acid (e.g., aqua regia, hydrofluoric acid, and perchloric acid) digestions and a $LiBO_2$ fusion method. The method validation results reveal that a $LiBO_2$ fusion and $Fe(OH)_3$ co-precipitation should be applied as the optimal sample digestion process for the quantitative analysis of radionuclides in building materials. The radioactivity of $^{232}Th$, $^{235}U$, and $^{238}U$ in a total of 51 building material (e.g., board, brick, cement, paint, tile, and wall paper) samples was quantitatively analyzed using an established process. Finally, the values of $^{238}U$ and $^{232}Th$ radioactivity were comprehensively compared with those from the indirect method using ${\gamma}$-spectrometry.

• Reproductive and Developmental Biology
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• v.31 no.2
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• pp.127-131
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• 2007

Embryonic germ (EG) cells are undifferentiated stern cells isolated from cultured primordial germ cells (PGC). These cells share many characteristics with embryonic stem cells including morphology and pluripotency. Undifferentiated porcine EG cell lines demonstrating capacities of differentiation both in vitro and in vivo have been established. Since EG cells can be cultured indefinitely in an undifferentiated state, whereas somatic cells in primary culture are often unstable and have limited lifespan, EG cells may provide inexhaustible source of karyoplasts in nuclear transfer (NT). In this study the efficiencies of NT using porcine EG and fetal fibroblast cells were compared. Two different techniques were used to perform NT. With conventional NT procedure (Roslin method) involving fusion of donor cells with enucleated oocytes, the rates of development to the blastocyst stage in EG and somatic cell NT were 16.8% (59/351) and 14.5% (98/677), respectively. In piezo-driven microinjection (Honolulu method) of donor nuclei into enucleated oocytes, the rates of blastocyst formation in EG and somatic cell NT were 11.9% (15/126) and 9.4% (9/96), respectively. Regardless of NT methods used in this study, EG cell NT gave rise to comparable rate of blastocyst development to somatic cell NT. Overall, EG cells can be used as karyoplast donor in NT procedure, and embryos can be produced by EG cell NT that may be used as an alternative to conventional somatic cell NT.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.121-128
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• 1998

In fields of operating or handling a hydrogen isotope facility, and of the technology for nuclear fusion source management, gas chromatography has been used as one of the practical techniques lot separation and enrichment of hydrogen isotopic gases including tritium. Chromatographic separation experiments of the hydrogen isotope mixture (hydrogen, deuterium and tritium) were carried out by use of a commercially available gas chromatograph. An aliquot of gas sample was injected by a specially designed vacuum sampler into the stream of inert carrier gas which went through the separation column under liquid nitrogen temperature. The complete separation of hydrogen isotopic molecules was observed with an alumina adsorbent partially deactivated by coating with 10% manganese chlorine. In addition, fairly good separation conditions were obtained without any appearance of nuclear spin isomers with shorter retention time, which would be available for the practical applications of the hydrogen isotope separation and enrichment.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.109-115
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• 2002

The present study was conducted for the production of transgenic cloned cows those secrete human lactoferricin into milk by somatic cell nuclear transfer (NT). To estimate detrimental effects of gene transfection on transgenic cloned embryo production, development rates of NT embryos were compared between transfected and non-transfected cumulus and ear fibroblast cells. An expression plasmid for human lactofericin (pbeta-LFC) was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and human lactoferricin target gene into a pcDNA3 plasmid. Two bovine somatic cell lines (cumulus cell and ear fibroblast) were established and transfected with the expression plasmid using a liposomal transfection reagent, Fugene6 as a carrier. Cumulus cell and ear fibroblast were transfected at the passage of 2 to 4, trypsinized and GFP-expressing cells were randomly selected and used for somatic cell NT. Developmental competences (rates of fusion, cleavage, and blastocyst formation) in bovine transgenic somatic cell NT embryos reconstructed with non-transfectecd cells were significantly higher than those from transfected cells in cumulus cell and ear fibroblast (P＜0.05). This study indicated that transfection of done. cell has detrimental effect on embryo development in bovine transgenic NT.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.101-108
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• 2002

Human Prourokinase (proUK) offers potential as a novel agent with improved fibrin specificity and, as such, may offer advantages as an attractive alternative to urokinase that is associated with clinical benefits in patients with acute peripheral arterial occlusion. For production of transgenic cow as human proUK bioreacotor, we conducted this study to establish efficient production system for bovine transgenic embryos by somatic cell nuclear transfer (NT) using human prourokinase gene transfected donor cell. An expression plasmid for human prourokinase was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and human prourokinase target gene into a pcDNA3 plasmid. Cumulus cells were used as donor cell and transfected with the expression plasmid using the Fugene 6 as a carrier. To increase the efficiency for the production of transgenic NT, development rates were compared between non-transfected and transfected cell in experiment 1, and in experiment 2, development rates were compared according to level of GFP expression in donor cells. In experiment 1, development rates of non-transgenic NT embryos were significantly higher than transgenic NT embryos (43.3 vs. 28.4％). In experiment 2, there were no significant differences in fusion rates (85.4 vs. 78.9％) and cleavage rates (78.7 vs. 84.4％) between low and high expressed cells. However, development rates to blastocyst were higher in low expressed cells (17.0 vs. 33.3％), and GFP expression rates in blastocyst were higher in high expressed cells (75.0 vs. 43.3％), significantly.

• Journal of the Korean Society of Radiology
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• v.9 no.1
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• pp.55-59
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• 2015

Research about the proton nuclear reaction is actively achieving on the proton therapy including material development of fusion reactor. The proton induced gamma ray energy(2754, 1386 keV) spectrum of 27Al(p,3p+n)24Na reaction was measured with 100 MeV high energy proton beam. The proton beam in the experiment was derived from 100 MeV proton linear accelerator in the KOMAC. We measured the gamma ray intensity ratio of the decay level from the energy spectrum. The previous results have been compared with the current result. Strength of measured gamma rays will provide very important information though decide high energy gamma radiation detection efficiency.

• Journal of Biomedical Engineering Research
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• v.31 no.2
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• pp.114-122
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• 2010

This paper presents a method that registers a lymphoscintigraphy to the real image captured by a CMOS camera, which helps surgeons to easily and precisely detect sentinel lymph nodes for sentinel lymph node biopsy in breast cancer patients. The proposed method consists of two steps: pre-matching and image registration. In the first step, we localize fiducial markers in a lymphoscintigraphy and a real image of a four quadrant bar phantom by using image processing techniques, and then determines perspective transformation parameters by matching with the corresponding marker points. In the second step, we register a lymphoscintigraphy to a real images of patients by using the perspective transformation of pre-matching. To examine the accuracy of the proposed method, we conducted an experiment with a chest mock-up with radioactive markers. As a result, the euclidean distance between corresponding markers was less than 3mm. In conclusion, the present method can be used to accurately align lymphoscintigraphy and real images of patients without attached markers to patients, and then provide useful anatomical information on sentinel lymph node biopsy.

• Progress in Medical Physics
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• v.27 no.3
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• pp.117-124
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• 2016

Intrafractional motion of patients, such as respiratory motion during radiation treatment, is an important issue in image-guided radiotherapy. The accuracy of the radiation treatment decreases as the motion range increases. We developed a control system for a robotic patient immobilization system that enables to reduce the range of tumor motion by compensating the tumor motion. Fusion technology, combining robotics and mechatronics, was developed and applied in this study. First, a small-sized prototype was established for use with an industrial miniature robot. The patient immobilization system consisted of an optical tracking system, a robotic couch, a robot controller, and a control program for managing the system components. A multi speed and position control mechanism with three degrees of freedom was designed. The parameters for operating the control system, such as the coordinate transformation parameters and calibration parameters, were measured and evaluated for a prototype device. After developing the control system using the prototype device, a feasibility test on a full-scale patient immobilization system was performed, using a large industrial robot and couch. The performances of both the prototype device and the realistic device were evaluated using a respiratory motion phantom, for several patterns of respiratory motion. For all patterns of motion, the root mean squared error of the corresponding detected motion trajectories were reduced by more than 40%. The proposed system improves the accuracy of the radiation dose delivered to the target and reduces the unwanted irradiation of normal tissue.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.333-338
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• 2013

The compressive residual stress and fatigue behavior of shot peened alloy 600 under a high-temperature environment is investigated in this study. Alloy 600 is used in the main parts of nuclear power plants, and the compressive residual stress induced by the shot peening process is considered to prevent SCC (stress corrosion cracking). To obtain practical results, the fatigue characteristics and compressive residual stress are evaluated under the actual operating temperature of a domestic nuclear power plant, as well as a high-temperature environment. The experimental results show that the peening effects are valid at a high temperature lower than approximately $538^{\circ}C$, which is the threshold temperature. The fatigue life was maintained at temperatures lower than $538^{\circ}C$, and the compressive residual stress at $538^{\circ}C$ was 68.2% of that at room temperature. The present results are expected to be used to obtain basic safety and reliability data.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.632-635
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• 2003

For the disposal of low-level radwaste from nuclear power plant need the determination of levels of radio nuclides in radwaste. These nuclides include the difficult-to-measure nuclides, so indirect methodology for the determination of the difficult-to-measure nuclides have to be developed. In this work, for the determination of $^129I(t_{1/2}=1.57{\times}10^7 years)$ in low-level radwaste from nuclear power plant is investigated. Recovery of Iodide in simulated waste($UO_2$ pellet) as a soluble and radwaste(resin, woolen fabric)as a insoluble samples are measured. After pretreatment of sample, $I_2$ are extracted from aqueous solution with $CCl_4$. Then I are extracted from $CCl_4$ with 0.1M $NaHSO_3$ aqueous solution. iodide in aqueous solution are determined by ion chromatography. The overall recovery yield is 76.7 (RSD 1.7%) for mixed-acid digestion method. Incase of woolen fabrics, overall recovery yield is 74.3 (RSD 2.2%) and recovery of iodide in resin 56.5(RSD 5.6%) for alkaline fusion method.