• Title/Summary/Keyword: nuclear proliferation

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Dissolution behavior of SrO into molten LiCl for heat reduction in used nuclear fuel

  • Kang, Dokyu;Amphlett, James T.M.;Choi, Eun-Young;Bae, Sang-Eun;Choi, Sungyeol
    • Nuclear Engineering and Technology
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    • v.53 no.5
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    • pp.1534-1539
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    • 2021
  • This study reports on the dissolution behavior of SrO in LiCl at varying SrO concentrations from low concentrations to excess. The amount of SrO dissolved in the molten salt and the species present upon cooling were determined. The thermal behavior of LiCl containing various concentrations of SrO was investigated. The experimental results were compared with results from the simulated results using the HSC Chemistry software package. Although the reaction of SrO with LiCl in the standard state at 650 ℃ has a slightly positive Gibbs free energy, SrO was found to be highly soluble in LiCl. Experimentally determined SrO concentrations were found to be considerably higher than those present in used nuclear fuel (<2 g/kg). As Sr-90 is one of the most important heat-generating nuclides in used nuclear fuel, this finding will be impactful in the development of fast, simple, and proliferation-resistant heat reduction processes for used nuclear fuel without the need for separating nuclear materials. Heat reduction is important as it decreases both the volume necessary for final disposal and the worker handling risk.

Induction of Apoptosis in HepG2 Human Hepatocellular Carcinoma Cells by a Novel Derivative of Ursodeoxycholic Acid (UDCA)

  • Park, Yoo-Hoi;Kim, Jung-Ae;Baek, Jin-Hyen;Jung, Eun-Jin;Kim, Tae-Hyong;Suh, Hongsuk;Park, Myung-Hwan;Kim, Kyu-Won
    • Archives of Pharmacal Research
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    • v.20 no.1
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    • pp.29-33
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    • 1997
  • The effects of ursodeoxycholic acid (UDCA) and its novel derivative, named as HS-1030, on the proliferation of HepG2, human hepatocellular carcinoma cells were investigated. Whereas UDCA had no significant effect in a concentration range we have tested, HS-1030 inhibited the proliferation of HepG2 cells in a concentration dependent manner. Surprisingly, HS-1030 had no effect on the proliferation of Human Chang liver cell which is a normal liver cell line. We also found that proliferation-inhibitory effect of HS-1030 was due to the induction of apoptosis of HepG2 cells, which was confirmed by observing the internucleosomal DNA fragmentation and morphological changes (ie., cell shrinkage, nuclear condensation and the formation of apoptotic bodies). These results suggest that HS-1030 may be a good candidate as a drug for the treatment of liver cancer.

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Inhibitory Effects on Bone Resorption and osteoblast proliferation of Kyungok-go (경옥고와 경옥고가연자육의 조골세포 증식과 골흡수 억제효과)

  • Kim, Ju-Ho;Lee, Jung-Ho;Oh, Jae-Min;Kim, Yun-Kyung
    • Herbal Formula Science
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    • v.19 no.2
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    • pp.61-71
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    • 2011
  • Objectives : Kyungok-go(KOG), the first herbal formulation of donguibogam, has been used for treating of many symptoms of yin deficiency. In this study, we examined the effect of KOG on bone resorption. Methods : We determined the effects of water extract of KOG in RANKL(Receptor Activator for Nuclear Factor ${\kappa}B$ Ligand)-induced osteoclast differentiation culture system and osteoblast proliferation. In addition, we determined the effects of water extract of ABR on LPS-induced bone-loss with mice. Results : Water extract of KOG showed proliferation effect on osteoblast without cytotoxicity and no effect on RANKL-treated osteoclast differentiation. KOG rescued bone erosion by LPS induction in vivo study. Conclusions : These results demonstrated that KOG can be a useful remedy for treating of bone-loss disease such as osteoporosis.

Imaging of Tumor Proliferation Using Iodine-131-Iodomethyluridine (Iodine-131-Iodomethyluridine을 이용한 종양세포증식의 영상화에 관한 실험적 연구)

  • Min Kyung-Yoon;Kim, Chang-Guhn;Kim, Hyun-Jeong;Lim, Hyung-Guhn;Rho, Ji-Young;Juhng Seon-Kwan;Won Jong-Jin;Yang, David J.
    • The Korean Journal of Nuclear Medicine
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    • v.30 no.3
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    • pp.344-350
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    • 1996
  • Purpose : Noninvasive imaging of tumor cell proliferation could be helpful in the evaluation of tumor growth potential and could provide an early assessment of treatment response. Radiolabeled thymidine, uridine and adenosine have been used to evaluate tumor cell proliferation. These nucleoside analogs are incorporated into DNA during proliferation. Iodine-131-Iodomethyluridine, an analog of Iodine-131-Iododeoxyuridine, is also involved in DNA/RNA synthesis. The purpose of this study was to develop Iodine-131-Iodomethylurdine and image tumor proliferation using Iodine-131-Iodomethyluridine. Materials and Methods : Radiosynthesis of Iodine-131-5-Iodo-2'-O-methyluridine (Iodine-131-Iodomethyluridine) was prepared from 10 mg of 2'-O-methyluridine(Sigma chemical Co., St. Louis, Missouri) and 2.1 mCi(SP. 10Ci/mg) of Iodine-131-labeled sodium iodide in $100{\mu}l$ of water using iodogen reaction. Female Fischer 344 rats were inoculated in the thigh area with breast tumor cells(13765 NF, $10^5$ cells/rat S.C.). After 14 days, the Iodine-131-Iodomethyluridine $10{\mu}Ci$ was injected to three groups of rats(3/group). The percent of injected dose per gram of tissue weight was determined at 0.5-hours, 2-hours, 4-hours, and 24-hours respectively. Tumor bearing rats after receiving Iodine-131-Iodomethyluridine($50{\mu}Ci$ IV) were euthanized at 2 hours after injection. Autoradiography was done using freeze-dried $50{\mu}m$ coronal section. After injection of Iodine-131- Iodomethyluridine ($10{\mu}Ci$/rat, IV) in three breast tumor-bearing rats, planar scintigraphy was taken at 45 minutes, 90 minutes and 24 hours. Results : Iodine-131-Iodomethyluridine was conveniently synthesized using iodogen reaction. The biodistribution showed fast blood clearance and the tumor-to-tissue uptake ratios showed that optimal imaging time was at 2 hours postinjection. Autoradiogram and planar scintigram indicated that tumor could be well visualized. Conclusion : The findings suggest that Iodine-131-Iodomethyluridine, a new radio-iodinated nucleoside, has potential use for evaluation of active regions of tumor growth.

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Nuclear·Atomic Public Diplomacy: The Possibility of Expanding Toward New Issue Area (핵·원자력 공공외교: 새로운 영역으로의 확장 가능성)

  • Hanhyung Lee
    • Public Diplomacy: Theory and Practice
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    • v.3 no.1
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    • pp.43-63
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    • 2023
  • Objectives: Nuclear security and atomic energy industry have always been the domain of political and economical diplomatic affairs. The issue of nuclear proliferation must be resolved politically or militarily given the importance of the problem, the impact it has on global security, the influence of major powers, and non-proliferation regimes. Considering scope of the budget, manpower, and scale of the project, the atomic energy issue was also viewed from an economic perspective. Therefore, the goal of this study is to depart from the conventional viewpoint and investigate if public diplomacy may be extended to a new issue domain of nuclear security and atomic energy. Methods: In order to determine whether there are any areas that overlap, the uniqueness of Korea's position in the nuclear security and atomic power domains is evaluated and compared with the traits of public diplomacy. Results: It seems plausible to broaden the scope and function of public diplomacy in that field given Korea's uniqueness in nuclear security and atomic energy issue and overlap with public diplomacy. This is especially true given that the state must take the leading role and that ongoing policy demands are made in light of Korea's security and economic structure. In reality, it is assessed that the Summer Fellows Program, run by the KAIST Nuclear Nonproliferation Education and Research Center (KAIST NEREC), has had a considerable impact on public diplomacy in the area of nuclear security and atomic energy. Conclusions: Nuclear security and atomic energy issues have traditionally been handled from the perspectives of political diplomacy, summit diplomacy, and economic diplomacy. However, this paper evaluate that the possibility of enhancing the role of public diplomacy in this issue area is high and underscore that the budget support, programs, and manpower for similar public diplomacy activities are needed. Through this, South Korea's nuclear security policy and atomic energy industry could be supported from international community and it will advance national interest.

NEUTRONICS INVESTIGATION OF CANADA DEUTERIUM URANIUM 6 REACTOR FUELED (TRANSURANICeTH) O2 USING A COMPUTATIONAL METHOD

  • GHOLAMZADEH, ZOHREH;MIRVAKILI, SEYED MOHAMMAD;KHALAFI, HOSSEIN
    • Nuclear Engineering and Technology
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    • v.47 no.1
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    • pp.85-93
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    • 2015
  • Background: $^{241}Am$, $^{243}Am$, and $^{237}Np$ isotopes are among the most radiotoxic components of spent nuclear fuel. Recently, researchers have planned different incineration scenarios for the highly radiotoxic elements of nuclear waste in critical reactors. Computational methods are widely used to predict burnup rates of such nuclear wastes that are used under fuel matrixes in critical reactors. Methods: In this work, the Monte Carlo N-particle transport code was used to calculate the neutronic behavior of a transuranic (TRU)-bearing CANada Deuterium Uranium 6 reactor. Results: The computational data showed that the 1.0% TRU-containing thorium-based fuel matrix presents higher proliferation resistance and TRU depletion rate than the other investigated fuel Matrixes. The fuel matrix includes higher negative temperature reactivity coefficients as well. Conclusion: The investigated thorium-based fuel matrix can be successfully used to decrease the production of highly radiotoxic isotopes.

A Study on the Acquirement of the Sensitive Nuclear Technology Through International Cooperation (국제협력을 통한 원자력 민감기술 확보방안에 관한 연구)

  • Lee Jae-Seong;Park Seung-Gi;Choe Yeong-Myeong
    • Journal of the military operations research society of Korea
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    • v.16 no.2
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    • pp.14-28
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    • 1990
  • The objective of this study is to propose how to acquire through international cooperation the sensitive nuclear technology, so called reprocessing technology. In spite of the need to reuse spent fuel, the transfer of the sensitive technology has been tightly controlled by the nuclear advanced countries due to the fear of nuclear proliferation and, in fact, it would be impossible to secure it by the economic means. In this regard, as a means of acquiring the sensitive nuclear technology, this study proposes the following; 1) President's declaration concerning the peaceful uses of nuclear energy, 2) the establishment and maintenance of national basis through inter-ministerial cooperation, 3) as a confidence building measure, the efforts to strengthen our role in the international nuclear community, and 4) the establishment of the synthetic feedback system to efficiently coordinate. In line with those stated above, this study suggests that it be necessary to invest consistently for developing new technologies and cultivating human resources. Furthermore, this study proposes the necessity to resolve the problems lying ahead by the national consensus achieved through the discussions among the public concerning the sensitive nuclear technology.

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Estrogen reinforces barrier formation and protects against tumor necrosis factor alpha-induced barrier dysfunction in oral epithelial cells

  • Choi, Yun Sik;Baek, Keumjin;Choi, Youngnim
    • Journal of Periodontal and Implant Science
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    • v.48 no.5
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    • pp.284-294
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    • 2018
  • Purpose: Epithelial barrier dysfunction is involved in the pathophysiology of periodontitis and oral lichen planus. Estrogens have been shown to enhance the physical barrier function of intestinal and esophageal epithelia, and we aimed to investigate the effect of estradiol (E2) on the regulation of physical barrier and tight junction (TJ) proteins in human oral epithelial cell monolayers. Methods: HOK-16B cell monolayers cultured on transwells were treated with E2, an estrogen receptor (ER) antagonist (ICI 182,780), tumor necrosis factor alpha ($TNF{\alpha}$), or dexamethasone (Dexa), and the transepithelial electrical resistance (TER) was then measured. Cell proliferation was measured by the cell counting kit (CCK)-8 assay. The levels of TJ proteins and nuclear translocation of nuclear factor $(NF)-{\kappa}B$ were examined by confocal microscopy. Results: E2 treatment increased the TER and the levels of junctional adhesion molecule (JAM)-A and zonula occludens (ZO)-1 in a dose-dependent manner, without affecting cell proliferation during barrier formation. Treatment of the tight-junctioned cell monolayers with $TNF{\alpha}$ induced decreases in the TER and the levels of ZO-1 and nuclear translocation of $NF-{\kappa}B$. These $TNF{\alpha}-induced$ changes were inhibited by E2, and this effect was completely reversed by co-treatment with ICI 182,780. Furthermore, E2 and Dexa presented an additive effect on the epithelial barrier function. Conclusions: E2 reinforces the physical barrier of oral epithelial cells through the nuclear ER-dependent upregulation of TJ proteins. The protective effect of E2 on the $TNF{\alpha}-induced$ impairment of the epithelial barrier and its additive effect with Dexa suggest its potential use to treat oral inflammatory diseases involving epithelial barrier dysfunction.