• Nuclear Engineering and Technology
• /
• v.50 no.1
• /
• pp.132-139
• /
• 2018

Nanocrystalline reduced activation ferritic/martensitic (RAFM) steel samples were prepared using surface mechanical attrition treatment (SMAT). Un-SMATed and SMATed reduced activation ferritic/martensitic samples were irradiated by helium ions at $200^{\circ}C$ and $350^{\circ}C$ with 2 dpa and 8 dpa, respectively, to investigate the effects of grain boundaries (GBs) and temperature on the formation of He bubbles during irradiation. Experimental results show that He bubbles are preferentially trapped at GBs in all the irradiated samples. Bubble denuded zones are clearly observed near the GBs at $350^{\circ}C$, whereas the bubble denuded zones are not obvious in the samples irradiated at $200^{\circ}C$. The average bubble size increases and the bubble density decreases with an increasing irradiation temperature from $200^{\circ}C$ to $350^{\circ}C$. Both the average size and density of the bubbles increase with an increasing irradiation dose from 2 dpa to 8 dpa. Bubbles with smaller size and lower density were observed in the SMATed samples but not in the un-SMATed samples irradiated in the same conditions, which indicate that GBs play an important role during irradiation, and sink strength increases as grain size decreases.

• Journal of Ginseng Research
• /
• v.43 no.3
• /
• pp.452-459
• /
• 2019

Background: Ginsenoside compound K(C-K), a major metabolite of ginsenoside, exhibits anticancer activity in various cancer cells and animal models. A cell signaling study has shown that C-K inhibited nuclear factor-kappa B ($NF-{\kappa}B$) pathway in human astroglial cells and liver cancer cells. However, the molecular targets of C-K and the initiating events were not elucidated. Methods: Interaction between C-K and Annexin A2 was determined by molecular docking and thermal shift assay. HepG2 cells were treated with C-K, followed by a luciferase reporter assay for $NF-{\kappa}B$, immunofluorescence imaging for the subcellular localization of Annexin A2 and $NF-{\kappa}B$ p50 subunit, coimmunoprecipitation of Annexin A2 and $NF-{\kappa}B$ p50 subunit, and both cell viability assay and plate clone formation assay to determine the cell viability. Results: Both molecular docking and thermal shift assay positively confirmed the interaction between Annexin A2 and C-K. This interaction prevented the interaction between Annexin A2 and $NF-{\kappa}B$ p50 subunit and their nuclear colocalization, which attenuated the activation of $NF-{\kappa}B$ and the expression of its downstream genes, followed by the activation of caspase 9 and 3. In addition, the overexpression of Annexin A2-K320A, a C-K binding-deficient mutant of Annexin A2, rendered cells to resist C-K treatment, indicating that C-K exerts its cytotoxic activity mainly by targeting Annexin A2. Conclusion: This study for the first time revealed a cellular target of C-K and the molecular mechanism for its anticancer activity.

• Nuclear Engineering and Technology
• /
• v.55 no.4
• /
• pp.1410-1419
• /
• 2023

Public perception plays a crucial role in the successful completion of a nuclear power project. As a newcomer country to nuclear power, there are lots of misconceptions among the Bangladeshi people about nuclear energy. Consequently, it is crucial to minimize all the doubts among mass people and build up their positive outlook toward nuclear power. This demands a comprehensive survey to figure out the public opinion, concerns, false impressions, and knowledge gap regarding nuclear power. In the present study, these issues were addressed by a survey that was responded to by 661 persons for the 24 survey questions. The questions were categorized based on information, knowledge, faith, benefit, awareness, and technology. Feedback and responders' basic demographic and socioeconomic information were collected from various locations in Bangladesh through online and in-person surveys. The responses were analyzed in both statistical and descriptive ways. Some of the feedback was found to vary with age, sex, and education level while others were quite independent of these parameters. It is found that socioeconomic development and energy security can be achieved by the inclusion of nuclear energy in the power system master plan of the country. However, huge knowledge gaps and misconceptions were found among the public regarding nuclear energy. As per feedback, political instability and corruption may affect the national nuclear power project in Bangladesh. Low faith in the existing rules & regulations for nuclear power programs was also observed. The result of this study will be handy to develop the communication and public awareness strategy for a successful nuclear power project in Bangladesh.

• KDI Journal of Economic Policy
• /
• v.40 no.1
• /
• pp.67-83
• /
• 2018

We have hypothesized that nuclear risk is significantly inversely related to the distance from residences to nuclear power plants and that the level of life satisfaction of residents therefore increases with the distance. We empirically explore the relationship between Ulsan citizens' life satisfaction levels and the distance between their residences and the Kori and Wolsong nuclear power plants (NPP) based on the life satisfaction approach (LSA). The dataset we used covers only Ulsan citizens from the biennial Ulsan Statistics on Citizen's Living Condition and Consciousness of 2014 and 2016. Controlling for micro-variables such as education, work satisfaction, gender, marital status, and expenditures, we found a statistically significant relationship between life satisfaction and the distance between the residences and the nuclear power plants. Nuclear negative externalities including (i) health and environmental impact, (ii) radioactive waste disposal, and (iii) the effect of severe accidents can be quantified in terms of LS units and monetary units. We were able to calculate the monetary value of NPP externalities at $277 per kilometer of distance for Kori and $280 per kilometer of distance for Wolsong at constant 2015 prices. These estimates are quite different from the traditional estimates made with the contingent valuation method, whereas they are similar to the findings of LSA studies abroad. Hence, the need to adopt the LSA in South Korea and policy implications are demonstrated.

• 한국초전도학회:학술대회논문집
• /
• v.12
• /
• pp.71-71
• /
• 2002

• 한국초전도학회:학술대회논문집
• /
• v.12
• /
• pp.84-84
• /
• 2002

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.11a
• /
• pp.49-50
• /
• 2018

• BMB Reports
• /
• v.40 no.2
• /
• pp.172-179
• /
• 2007

PCR-mediated recombination describes the process of in vitro chimera formation from related template sequences present in a single PCR amplification. The high levels of genetic redundancy in eukaryotic genomes should make recombination artifacts occur readily. However, few evolutionary biologists adequately consider this phenomenon when studying gene lineages. The cytosolic glyceraldehyde-3-phosphate dehydrogenase gene (GapC), which encodes a NADP-dependent nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase in the cytosol, is a classical lowcopy nuclear gene marker and is commonly used in molecular evolutionary studies. Here, we report on the occurrence of PCR-mediated recombination in the GapC gene family of Hibiscus tiliaceus. The study suggests that recombinant areas appear to be correlated with DNA template secondary structures. Our observations highlight that recombination artifacts should be considered when studying specific and allelic phylogenies. The authors suggest that nested PCR be used to suppress PCRmediated recombination.

• Nuclear Engineering and Technology
• /
• v.51 no.4
• /
• pp.1132-1141
• /
• 2019

Steel-concrete-steel (SCS) sandwich structures have important advantages over conventional concrete structures, however, bond-slip between the steel plate and concrete may lead to a loss of composite action, resulting in a reduction of stiffness and fatigue life of SCS sandwich structures. Due to the inaccessibility and invisibility of the interface, the interfacial performance monitoring and debonding detection using traditional measurement methods, such as relative displacement between the steel plate and core concrete, have proved challenging. In this work, two methods using piezoelectric transducers are proposed to detect the bond-slip between steel plate and core concrete during the test of the beam. The first one is acoustic emission (AE) method, which can detect the dynamic process of bond-slip. AE signals can be detected when initial micro cracks form and indicate the damage severity, types and locations. The second is electromechanical impedance (EMI) method, which can be used to evaluate the damage due to bond-slip through comparing with the reference data in static state, even if the bond-slip is invisible and suspends. In this work, the experiment is implemented to demonstrate the bond-slip monitoring using above methods. Experimental results and further analysis show the validity and unique advantage of the proposed methods.

• Journal of Embryo Transfer
• /
• v.30 no.3
• /
• pp.229-237
• /
• 2015

To improve the developmental potential of bovine somatic cell nuclear transfer (SCNT) embryos, this study compared the developmental rates to blastocyst stage in the SCNT embryos using donor fibroblasts treated with 5-azacytidine (5AC) and S-adenosylhomocysteine (SAH) at different concentrations. Their reprogramming efficiency level was investigated with level of telomerase activity. Donor fibroblasts isolated from adult ear skin of a cow were exposed to 5AC and SAH at different concentrations during 2 passages. After nuclear transfer into enucleated recipient oocytes, the cleavage and developmental rates were significantly (p<0.05) decreased in the SCNT embryos using 5AC-treated fibroblasts (5AC-SCNT embryos), compared with those of non-treated control (control-SCNT embryos) and SAH-treated fibroblasts (SAH-SCNT embryos). The developmental rates to blastocyst stage tended to be slightly increased in the SAH-SCNT embryos at each of the concentrations, and especially, the developmental rates in the SCNT embryos using 1.0 mM SAH-treated fibroblasts were significantly (p<0.05) higher than that of control SCNT embryos. The mean numbers of total and ICM cell in blastocysts were also significantly (p<0.05) decreased in the 5AC-SCNT embryos, compared with those of other SCNT blastocysts. Further, the level of telomerase activity was also significantly (p<0.05) decreased in the 5AC-SCNT embryos than those of control and SAH-SCNT embryos. Whereas, a significantly (p<0.05) up-regulated telomerase activity was observed in SAH-SCNT embryos, compare with that of control-SCNT embryos. In conclusion, SCNT embryos using hypomethylated donor cells with SAH, not 5AC, may improve the developmental potential and reprogramming efficiency.