• 한국정보통신학회논문지
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• 제16권5호
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• pp.1102-1112
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• 2012

미국의 한반도 정책은 비핵화이다. 미국정부는 북한의 핵위협을 제거하기 위해 군사행동의 가능성을 고려했었다. 군사행동 고려는 1993년 중반부터 1994년 중반까지 정점에 달했다. 그러한 공격은 직접적으로 한국전을 일으켰을 것이다. 당시 북핵위기는 북미협상과 한미동맹에 의해 해결되었다. PSI의 목적은 지구적 또는 지역적 안보에 심각한 위협을 일으키는 국가나 비국가행위자에게 대량살상무기, 운반체계, 관련 물질의 확산을 막거나 적어도 억제하는 것이다. PSI의 가장 논쟁의 여지가 있는 활동은 차단이다. 북한은 구상에 대해 심각한 우려를 표명하면서 다음과 같이 언급하였다. 무기를 개발하고, 배치하고, 수출하는 것은 주권이다. 그리고 자신들의 선박에 대한 차단은 선전 포고로 간주할 것이다. 한국이 북한선박에 대한 차단을 시행하면 북한은 도발로 대응할 것이므로 한반도의 긴장은 극적으로 증가할 것이다. 한국은 한미동맹과 남북관계를 고려해야하기 때문에 PSI에 매우 조심스럽게 접근하지 않을 수 없다.

• Animal cells and systems
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• 제16권3호
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• pp.173-182
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• 2012

The p53 protein plays a pivotal role in tumor suppression. The cellular level of p53 is normally kept low by proteasome-mediated degradation, allowing cell cycle progression and cell proliferation. Under stress conditions, such as DNA damage, p53 is stabilized and activated through various post-translational modifications of itself as well as of its regulatory proteins for induction of the downstream genes responsible for cell cycle arrest, DNA repair, and apoptosis. Therefore, the level of p53 should be tightly regulated for normal cell growth and for prevention of the accumulation of mutations in DNA under stress conditions, which otherwise would lead to tumorigenesis. Since the discovery of Mdm2, a critical ubiquitin E3 ligase that destabilizes p53 in mammalian cells, nearly 20 different E3 ligases have been identified and shown to function in the control of stability, nuclear export, translocation to chromatin or nuclear foci, and oligomerization of p53. So far, a large number of excellent reviews have been published on the control of p53 function in various aspects. Therefore, this review will focus only on mammalian ubiquitin E3 ligases that mediate proteasome-dependent degradation of p53.

• BMB Reports
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• 제52권4호
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• pp.265-270
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• 2019

We investigated whether SIRT1 is associated with reactive oxygen species (ROS) accumulation during CK2 downregulation-mediated senescence. SIRT1 overexpression suppressed ROS accumulation, reduced transcription of FoxO3a target genes, and nuclear export and acetylation of FoxO3a, which were induced by CK2 downregulation in HCT116 and MCF-7 cells. Conversely, overexpression of a dominant-negative mutant SIRT1 (H363Y) counteracted decreased ROS levels, increased transcriptional activity of FoxO3a, and increased nuclear import and decreased acetylation of FoxO3a, which were induced by CK2 upregulation. CK2 downregulation destabilized SIRT1 protein via an ubiquitin-proteasome pathway in human cells, whereas CK2 overexpression reduced ubiquitination of SIRT1. Finally, the SIRT1 activator resveratrol attenuated the accumulation of ROS and lipofuscin as well as lifespan shortening, and reduced expression of the DAF-16 target gene sod-3, which were induced by CK2 downregulation in nematodes. Altogether, this study demonstrates that inactivation of the SIRT1-FoxO3a axis, at least in part, is involved in ROS generation during CK2 downregulation-mediated cellular senescence and nematode aging.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2540-2549
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• 2022

For a pressurized water reactor power plant, the reactor coolant pump (RCP) is a kernel component. And for a canned motor RCP, the rotor system's properties determines its safety. The liquid coolant inside the canned motor RCP fills clearance between the metal shields of rotor and stator, forming a lengthy clearance flow. The influence of inlet preswirl on rotordynamic coefficients of clearance flow in canned motor RCP and their effects on the rotordynamic characteristics of the pump are numerically and experimentally investigated in this work. A quasi-steady state computational fluid dynamics (CFD) method has been used to investigate the influence of inlet preswirl. A vertical experiment rig has also been established for this purpose. Rotordynamic coefficients on different inlet preswirl ratios (IR) are obtained through CFD and experiment. Results show that the cross-coupled stiffness of the clearance flow would change significantly with inlet preswirl, but other rotordynamic coefficients would not change significantly with inlet preswirl. For the case of clearance flow between the stator and rotor cans, influence of inlet preswirl is not so significant as the IR is not large enough.

• BMB Reports
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• 제42권5호
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• pp.299-303
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• 2009

In this study, we use promoter analysis to show that interaction between Jab1 and p53 induces suppression of p53 activation in U2OS and H1299 cells. Interaction between p53 and Jab1 was further confirmed by immunoprecipitation and immunofluorescent analyses. In particular, Jab1 was able to induce nuclear export of p53 as previously reported. When Jab1 was overexpressed in U2OS cells followed by etoposide or hydrogen peroxide ($H_2O_2$), cell death induced by such stresses was protected against. On the contrary, when the level of Jab1 was suppressed in U2OS cells, cytotoxicity imposed by etoposide and $H_2O_2$ was dramatically increased, suggesting a cell protective role for Jab1. These results indicate that Jab1 is a negative regulator of p53 and a plausible oncogene.

• 기술혁신연구
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• 제10권2호
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• pp.131-148
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• 2002

This paper explores how international political factors influence the role of conventional external factors in the course of technological learning. The research goes on to investigate whether the role of the techno-economic factors has changed due to the involvement of international political factors in the technological learning mechanism. To this end, this paper examines how US political intervention affected Korean technological learning in the back-end of the nuclear fuel cycle. The export policy, prior consent policy and international political influence of the US are employed as international political factors. The empirical findings show that international political factors are very likely to restrain the impact of the techno-economic factors on technological learning process. Accordingly, this paper hypothesizes that the role of techno-economic factors in the technological learning mechanism is weaker when international political intervention is involved.

• Biomolecules & Therapeutics
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• 제20권2호
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• pp.144-151
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• 2012

The molecular mechanisms by which a variety of naturally-occurring dietary compounds exert chemopreventive effects have been a subject of intense scientific investigations. Induction of phase II detoxification and anti-oxidant enzymes through activation of Nrf2/ARE-dependent gene is recognized as one of the major cellular defense mechanisms against oxidative or xenobiotic stresses and currently represents a critical chemopreventive mechanism of action. In the present review, the functional significance of Keap1/Nrf2 protein module in regulating ARE-dependent phase II detoxification and anti-oxidant gene expression is discussed. The biochemical mechanisms underlying the phosphorylation and expression of Keap1/Nrf2 proteins that are controlled by the intracellular signaling kinases and ubiquitin-mediated E3 ligase system as well as control of nucleocytoplasmic translocation of Nrf2 by its innate nuclear export signal (NES) are described.

• 무역학회지
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• 제44권4호
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• pp.19-34
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• 2019

This study investigates the WTO dispute over Japanese fishery products originated from Fukushima and another seven prefectures. Being subject to an import ban and additional radioactive test requirements, Japan complained that the Korean government's trade measures are inconsistent with the principles of the Agreement on Sanitary and Phytosanitary Measures. This paper considered the contrasting judicial decisions made by the Panel and Appellate Body and analyzed the debates with respect to their trade-discriminatory effects (Article 2.4), the relevance of appropriate level of protection (Article 5.6) and the precautionary approaches (Article 5.7). Consistent with the final rulings, this paper identifies the need for a broaden understanding of regional conditions and qualitative aspects of protection in risk analysis. Findings also suggest that Korea has diverted its fishery imports from Japan to other countries, while Japan has created export diversion from Korea to other destinations.

• 무역학회지
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• 제47권4호
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• pp.15-33
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• 2022

This study is to investigate multilateral environmental agreements,mainly UNFCCC on the primary export industry of Korea and to make a policy recommendation. Mostly literature reviews are focused on the traditional multilateral environmental agreements and the for the most part analysis are conducted prior to the Paris agreement. The result of survey indicates that many companies have not yet felt burden on their business due to UNFCCC(decarbonization) and have monitored the related policies. But the companies ask the government for strong incentives. The paper implies that enforcing strong government incentives, upgrading usage of the nuclear power, improving the related government legislation, setting up the special task force team with government and private sectors are needed.

• 미생물학회지
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• 제44권2호
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• pp.105-109
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• 2008

발아효모 Saccharomyces cerevisiae의 핵공단백질인 Nic96 단백질과 유사성을 보이는 분열효모 Schizosaccharomyces pombe의 Nup97의 기능과 세포 내 위치를 조사하였다. nup97을 과 발현시켰을 때는 생장과 $poly(A)^{+}$ RNA의 분포에 별다른 이상을 보이지 않았다. 하지만, $kan^{r}$ 유전자를 이용하여 제작한 ${\Delta}nup97$ 결실돌연변이는 nup97의 발현이 억제되면, $poly(A)^{+}$ RNA가 핵 안에 축적되었고 비정상적인 DNA 분포를 보였으며 결국 생장하지 못했다. 한편, Nup97p의 N말단 또는 C말단에 GFP를 붙인 Nup97-GFP 융합단배질의 세포 내 위치를 확인하고자 하였다. 이러한 융합단백질들이 ${\Delta}nup97$ 결실돌연변이의 생장결함을 정상적으로 상보하는 것을 확인하고, nup97-GFP 유전자를 염색체의 nup97 유전자 위치에 삽입한 균주를 제작하였다. 자신의 프로모터에서 발현된 Nup97-GFP 융합단백질은 정상적인 기능을 보였으며, 핵막 주위에 점점 이 위치하였다. 이와 같은 결과들은 Nup97 단백질 역시 핵공단배질로 mRNA의 핵에서 세포질로의 이동에 중요하다는 것을 시사한다.