• Progress in Medical Physics
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• v.21 no.1
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• pp.16-21
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• 2010

To acquire good image quality and to minimize unnecessary radiation dose to patients, it is important to ensure that the radiopharmaceutical administered is accurately measured. Quality control of radionuclide calibrators should be performed to achieve these goals. The purpose of this study is to support the quality control of radionuclide calibrators in nuclear medicine centers and to investigate the level of measurement accuracy of the radionuclide calibrators. 58 radionuclide calibrators from 45 nuclear medicine centers, 74 radionuclide calibrators from 58 nuclear medicine centers, and 60 radionuclide calibrators from 45 nuclear medicine centers were tested with I-131, Tc-99m and I-123, respectively. The results showed that 81% of calibrators for I-131, 61% of calibrators for Tc-99m and 67% of calibrators for I-123 were within ${\pm}5%$. 17% of calibrators for I-131, 20% of calibrators for Tc-99m and 15% of calibrators for I-123 had a deviation in the range 5%< $|{\Delta}|{\leq}10%$. 2% of calibrators for I-131, 19% of calibrators for Tc-99m and 18% of calibrators for I-123 had a deviation of $|{\Delta}|$ >10%. Follow-up measurements were performed on the calibrators whose error exceeded the ${\pm}10%$ limit. As a result, some of the calibrator showed an improvement and their deviation decreased below the ${\pm}10%$ limit. The results have shown that such comparisons are necessary to improve the accuracy of the measurement and to identify malfunctioning radionuclide calibrators.

• Journal of Embryo Transfer
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• v.20 no.2
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• pp.105-112
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• 2005

The present study was conducted to examine some factors affecting in vitro development of oocytes from somatic cell nuclear transfer (SCNT) in Korean native goats. Recipient oocytes were surgically collected after superovulation by using CIDR and FSH, PMSG, hCG and estrous synchronization in Korean Native goats. For nuclear transfer, the fibroblasts from caprine ear cells and fetal fibroblasts were surgically harvested and were cultured in vitro until cell confluency in serum-starvation condition (TCM-199 + $0.5\%$ FBS) for 3 to 5 days. The zona pellucidae of matured oocytes were partially drilled by laser irradiation. A single somatic cell was individually transferred into each enucleated oocyte. The reconstructed oocytes were then electrically fused and activated. Activated NT embryos were cultured in mSOF medium supplemented with $0.8\%\;BSA\;6\~7\;day\;at\;39^{\circ}C,\;5\%\;CO_2,\;5\%\;O_2,\;90\%\;N_2$ in air. There were no significant difference in the number of embryos cleaved and 4-cell development between the fibroblast nuclei from mature ear cells and fetal cells, but the rate of 8-cell development was higher (P<0.05) in ear cells $(40.5\%)$ than in fetal cells $(55.5\%)$. However, the embryo development to morula or blastocyst was not significantly different between both the groups$(6.7\%\;vs\;16.0\%)$, respectively. The number of embryo cleaved $(79.0\%)$ were higher (P<0.05) in the oocytes activated with ionomycin+6-DMAP than in the oocytes activated electrically $(9.5\%)$. The development of fused embryos to morula or blastocyst was found $15.6\%$ in ionomycin+6-DMAP, but no morula or blastocysts were developed in electrical stimulation. The development rate of SCNT embryos to morula or blastocyst was love. (P<0.05) in SCNT embryos $(19.0\%\;vs\;0.0\%)$ than that in parthenotes $(66.1\%\;vs\;59.1\%)$. In the parthenotes, the cleavage rate and development to morula or blastocyst were significantly higher (P<0.05) as $86.8\%\;and\;50.0\%$ in ovulated oocytes than in follicular oocytes $(69.0\%\;vs\;23.6\%)$, respectively. These results suggest that some factors Including superovulation treatment, oocyte source, maturation of follicular oocytes, activation method and culture condition may affect in vitro developmental capability of embryos produced by somatic cell nuclear transfer in Korean Native goats, and the fusion rate be greatly low compared with other species.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.337-341
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• 2004

Engineering ceramics have superior heat resistance, corrosion resistance, and wear resistance. Consequently, these art significant candidates for hot-section structural components of heat engine and the inner containment of nuclear fusion reactor. Besides, some of them have the ability to heal cracks and great benefit can be anticipated with great benefit the structural engineering field. Especially, law fracture toughness of ceramics supplement with self-healing ability. In the present study, we have been noticed some practically important points for the healing behavior of silicon nitride, alumina, mullite with SiC particle and whisker. The presence of silicon carbide (SiC) in ceramic compound is very important for crack-healing behavior. However, self-healing of SiC has not been investigated well in detail yet. In this study, commercial SiC was selected as sample, which can be anticipated in the excellent crack healing ability. The specimens were produced three-point bending specimen with a critical semi-circular crack of which size that is about $50-700{\mu}m$. Three-point bending test and static fatigue test were performed cracked and healed SiC specimens. A monotonic bending load was applied to cracked specimens by three-point loading at different temperature. The purpose of this paper is to report Strength Properties and Elastic Waves Characteristics of Silicon Carbide with Crack Healing Ability.

• Carbon letters
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• v.22
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• pp.81-88
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• 2017

In the present study, biomass-based lignin was extracted from industrial waste black liquor and the extracted lignin was characterized by means of attenuated total reflectance-Fourier transform infrared spectroscopy and $^1H-nuclear$ magnetic resonance spectroscopy. The extracted lignin was carbonized at different temperatures and then activated with steam at $850^{\circ}C$. The extracted lignin in powder state was transformed into a bulky carbonized lignin due to possible fusion between the lignin particles occurring upon carbonization. The carbonized and then pulverized lignin exhibits brittle surfaces, the increased thermal stability, and the carbon assay with increasing the carbonization temperature. The scanning electron microscopic images and the Brunauer-Emmett-Teller result indicate that the steam-activated carbon has the specific surface area of $1718m^2/g$, which is markedly greater than the carbonized lignin. This study reveals that biomass-based activated carbon with highly porous structure can be produced from costless black liquor via steam-activation process.

• Tuberculosis and Respiratory Diseases
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• v.62 no.3
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• pp.232-236
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• 2007

Primary pulmonary artery sarcoma is a rare malignant tumor arising from the pulmonary artery. Diagnosis of primary pulmonary artery sarcoma is quite difficult and the conditon is often misdiagnosed as a more common disease, such as a pulmonary embolism. PET can help in diagnosing a pulmonary artery sarcoma due to the increased uptake of $^{18}F-FDG$ in the area of the tumor. However, the poor anatomic resolution of PET has limited its clinical applications in pulmonary vascular disease. The recently developed PET/CT is the fusion of PET and CT that improves the anatomical resolution of PET. We report a case of a primary pulmonary artery sarcoma mimicking a pulmonary embolism that was diagnosed with PET/CT and confirmed with a surgical resection.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.83-88
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• 2018

Additive manufacturing (AM) technologies have attracted wide attention as key technologies for the next industrial revolution. Among AM technologies using various materials, powder bed fusion (PBF) processes and direct energy deposition (DED) are representative of the metal 3-D printing process. Both of these processes have a common feature that the laser is used as a heat source to fabricate the 3-D shape through melting of the metal powder and solidification. However, the material properties of the deposited metals differ when produced by different process conditions and methods. 17-4 precipitation-hardening stainless steel (17-4PH SS) is widely used in the field of aircraft, chemical, and nuclear industries because of its good mechanical properties and excellent corrosion resistance. In this study, we investigated the differences in microstructure and mechanical properties of deposited 17-4PH SS by PBF and DED processes, including the heat treatment effect.

• Proceedings of the KSAR Conference
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• 2000.10a
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• pp.7-8
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• 2000

Transgenic animals are very useful for scientific, pharmaceutical, and agricultural purposes. In livestock, transgenic technology has been used forthe genetic alteration of farm animals, the production of human proteins inlarge quantities in the milk of transgenic farm animals, and the generation of animals with organs suitable for xenotransplantation. To date, the transfer of foreign genes into farm animals has been performed mainly by microinjection of DNA into the pronuclei of fertilized eggs. However, the overall success rate of transgenic animals in livestock so far has been disappointingly low, eg., the efficiency is 0∼5% in swine, and less than 1% in sheep and cattle, compared with the rate in mice where 5% microinjected develop into transgenic animals. Recently, McGreath et al. (2000) have succeeded in producing the gene targeted sheep by the use of nuclear transfer from cultured somatic cells transfected with a foreign gene in vitro. However, we may need plenty of time until currently employ this method for gene transfer to farm animals. We have been studying to exploit the method for improving production efficiencies of transgenic animals with emphasis of its application to farm animals. The present paper describes three approaches that we have made in our laboratory to improve production efficiencies of transgenic animals, based on the DNA microinjection method. 1. Co-injection of restriction enzyme with foreign DNA into the pronucleus for elevating production efficiencies of transgenic animals. 2. Efficient selection of transgenic mouse embryos using EGFP as a marker gene. 3. Phenotypes of tansgenic mice expressing WAP/hGH-CAG/EGFP fusion gene produced by selecting transgenic embryos. 4. Efficient site-specific integration of the transgene targeting an endogenous lox like site in early mouse embryos.

• Journal of fish pathology
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• v.24 no.3
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• pp.205-211
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• 2011

All of the crucian carp, Carassius auratus and 50% of common carp. Cyprinus carpio examined in this study were infected with the leeches, Limnotrachelobdella sinensis. Especially, the infection of C. carpio with L. sinensis was the first report in Korea. The gill of C. auratus showed increased hydrophic degeneration of epithelial cell in the filament, blood congestion, hyperplasia of epithelial cell in the filament and lamellae. In the SEM observation, gill filament was transformed to the cylinder form by the lamellae fusion. The lamellae surface showed degeneration, fragmentation of microridges. The extracellular cartilaginous matrix of the filaments was exposed by the collapse of epidermal layer. In the 18S rRNA analysis of L. sinensis, the relationships among these groups are not clear and not concord with their morphological classification.

• The Journal of Korean Society of Virology
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• v.29 no.3
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• pp.145-153
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• 1999

We have now constructed a novel recombinant baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV) producing polyhedra with Bacillus thuringiensis (Bt) CryIAc crystal protein. The recombinant polyhedra produced by the recombinant baculovirus, Btrus, in insect cells was characterized. The recombinant baculovirus has two independent transcription units in opposite orientations with two promoters, p10 or polyhedrin gene promoter each initiating transcription of either native polyhedrin or fusion protein with polyhedrin and Bt Cry1Ac crystal protein. Surprisingly, this recombinant baculovirus stably produced recombinant polyhedra which were nearly similar to those of wild-type AcNPV. The immunogold staining experiment showed that the recombinant polyhedra were assembled with polyhedrin and Bt Cry1Ac crystal protein, and contained virus particles. Insecticidal toxicity of recombinant polyhedra of Btrus to the fall webworm, Hyphantria cunea, was strikingly improved in comparison with the wild-type AcNPV.

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.1
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• pp.49-55
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• 2003

We describe the generation of transgenic silkworm that carrying the chimeric fibroin light chain (L-chain) gene. Previously, we have cloned the complete fibroin L-chain gene from the silkworm Baekok-Jam, Bombyx mori, and the complete fibroin gene from the oak silkworm, Antheraea yamamai. The 444 bp repetitive sequence of A. yamamai fibroin gene was inserted into the exon 6 of B. mori fibroin L-chain gene to produce chimeric fibroin L-chain gene. The chimeric fibroin L-chain gene was cloned into the polyhedrin gene site of Autographa californica nuclear polyhedrosis virus (AcNPV) to yield a recombinant baculovirus as a fibroin gene targeting vector, One-day-old fifth instar female silkworm larvae were injected with the recombinant baculovirus and then mated with normal male moths. Genomic DNA from their progenies was extracted and screened for the desired targeting event by using PCR and Southern blot analysis. The analysis showed that the chimeric fibroin gene had intergrated into the L-chain gene on the genome by homologous recombination and was transmitted through generations. The transgenic silkworm carrying the chimeric fibroin gene were approximately 43.2% in $F_2$ generation, and the silkworms synthesized the fusion protein in cocoons layer.