• Molecules and Cells
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• v.38 no.9
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• pp.814-820
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• 2015

PinX1, a nucleolar protein of 328 amino acids, inhibits telomerase activity, which leads to the shortening of telomeres. The C-terminal region of PinX1 is responsible for its nucleolar localization and binding with TERT, a catalytic component of telomerase. A fraction of TERT localizes to the nucleolus, but the role of TERT in the nucleolus is largely unknown. Here, we report a functional connection between PinX1 and TERT regarding PinX1 stability. The C-terminal of $PinX1^{205-328}$, a nucleolar fragment, was much more stable than the N-terminal of $PinX1^{1-204}$, a nuclear fragment. Interestingly, PinX1 was less stable in TERT-depleted cells and more stable in TERT-myc expressing cells. Stability assays for PinX1 truncation forms showed that both $PinX1^{1-328}$ and $PinX1^{205-328}$, nucleolar forms, were more rapidly degraded in TERT-depleted cells, while they were more stably maintained in TERT-overexpressing cells, compared to each of the controls. However, $PinX1^{1-204}$ was degraded regardless of the TERT status. These results reveal that the stability of PinX1 is maintained in nucleolus in the presence of TERT and suggest a role of TERT in the regulation of PinX1 steady-state levels.

• Mycobiology
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• v.46 no.2
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• pp.92-100
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• 2018

The filamentous Ascomycota Colletotrichum gloeosporioides sensu lato is a fungus that has been reported worldwide as a causal agent of anthracnose disease in avocado and other crops. In Mexico, this species affects fruits from an early stage of development in the orchard until the post-harvest stage. Although fungicides are continuously applied to control Colletotrichum species, pericarp cankers and soft rot mesocarp in fruits are still frequently observed. Considering the lack of a precise description of the causative agent, the aim of the current study was to determine the pathogens involved in this symptomatology. Twenty-four isolates were consistently obtained from the pericarp of avocado fruits cv. "Hass" collected in the central avocado-producing area of Mexico. Morphological features such as colony growth, conidia size, and mycelial appressorium were assessed. Bayesian multilocus phylogenetic analyses were performed using amplified sequences of the internal transcribed spacer region of the nuclear ribosomal DNA; actin, chitin synthase, glyceraldehyde-3-phosphate dehydrogenase partial genes; and APn2-Mat1-2 intergenic spacer and mating type Mat1-2 partial gene from the nine selected isolates. In addition, fruits were inoculated with a conidial suspension and reproducible symptoms confirmed the presence of Colletotrichum fructicola in this area. This pathogenic species can now be added to those previously reported in the country, such as C. acutatum, C. boninense, C. godetiae, C. gloeosporioides, and C. karstii. Disease management programs to reduce the incidence of anthracnose should include C. fructicola to determine its response to fungicides that are routinely applied, considering that the appearance of new species is affecting the commercial quality of the fruits and shifting the original population structure.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.134-139
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• 2002

Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. However, effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. Acoustic emission(AE) has been widely used in various fields because of its extreme sensitivity, dynamic detection ability and location of growing defects. In this study, we investigated failure modes of locally wall thinned pipes and AE signals by bending test. From test results, we could be divided four types of failure modes of ovalization, crack initiation after ovalization, local buckling and crack initiation after local buckling. And fracture behaviors such as elastic region, yielding range, plastic deformation range and crack progress could be evaluated by AE counts, accumulative counts and time-frequency analysis during bending test. It is expected to be basic data that can protect a risk according to local wall thinning of pipes, as a real time test of AE.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.341-344
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• 2005

The expression of the glutathione S-transferase (GST), whose induction accounts for antioxidant defense system, is regulated by activation of CCAAT/enhancer binding protein ${\beta}$ ($C/EBP{\beta}$), Sick house syndrome (SHS) presents healthy damage owing to the indoor environment of a building. Toluene has been implicated in one of the important causes of SHS. The present study investigated the effects of toluene treatment on the induction of GSTA2 gene and its mechanism. H411E cells treated with toluene, and GSTA2 expression was determined by immunoblot analysis. The translocation of $C/EBP{\beta}$ was assessed by immunocytochemical assays. $C/EBP{\beta}$ DNA binding activity was determined by electrophoretic mobility shift assays. The role of the C/EBP binding site in the induction of the GSTA2 gene was assessed by luciferase reporter-gene activity. Toluene induced GSTA2 protein expression. In toluene-treated cells, $C/EBP{\beta}$ translocated to the nucleus and bound to the consensus sequence of C/EBP (TTGCGCAA). Toluene treatment increased luciferase reporter-gene activity in cells transfected with the C/EBP-containing regulatory region of the GSTA2 gene. Oxidative stress is believed to play an important role in the induction of GSTA2 gene by toluene This study shows that toluene-induced GSTA2 gene expression is dependent upon nuclear translocation and binding of $C/EBP{\beta}$ to the C/EBP response element in the GSTA2 gene promoter.

• Journal of Energy Engineering
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• v.22 no.2
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• pp.148-155
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• 2013

The steam generators of OPR-1000 plants have Alloy 600 and Alloy 690 as the tube material and its tube expansion method is the explosive expansion method. According to the experience of these plants, circumferential cracks were largely occurred in steam generator tubes expanded by the explosive expansion method and their locations were the outer surface of tube expansion transition region surrounding with piled-up sludge. But even though tubes have the same conditions, tubes with the hydraulic expansion method shows the prevail trend of axial cracks compared to circumferential cracks. Therefore in this study, in order to identify the difference of such phenomena as above, configurations of tube and tubesheet were modeled and at operating conditions, stress values applied in the tube expansion transition area in accordance with tube expansion methods were calculated by using computational program and the direction and the predominance of cracks were evaluated.

• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.37-44
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• 1991

- I aimed to isolate trans-acting factors involved in the basal expression level of eukaryotic genes. One of the yeast histidine biosynthetic gene, HIS5 was taken as a model for this study. HIS5 gene has a substantial basal level in amino acid rich medium and is derepressed if starved for any single amino acid. The derepression is mediated by cis-acting DNA sequences 5'-TGACTC-3' found in 5' non-transcribed region of the gene and trans-acting factors including GCN4 as positive factor and its negative factor GCDI 7, and GCNZ as a negative factor of GCD17. I first investigated the role of these trans-acting factors in HIS5 basal expression level by using HIS5-pH05 fusion in which expression of pH05 gene encoding inorganic phosphate-repressible acid phosphatase (APase) is regulated by HIS5 promoter. Strain with gcn2 or gcn4 mutation showed 3 to 4 fold lower APase activity than wild type. The level of APase activity was similar in gcn2 and gcn4 mutants. Trans-acting factors involved in basal level were identified by isolating 14 mutants showing increased expression of HISSPH05 fusion from gcn4 background. All the mutants carry a single nuclear recessive mutation and fall into four complementation groups, designated as bell (basal expression level), be12, be23 and be14.

• BMB Reports
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• v.36 no.4
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• pp.354-358
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• 2003

For better understanding of functions of the Calcyclin Binding Protein (CacyBP) and exploring its possible roles in neuronal differentiation, the subcellular localization of human CacyBP was examined in retinoic acid(RA)-induced and uninduced neuroblastoma SH-SY5Y cells. Immunostaining indicated that CacyBP was present in the cytoplasm of uninduced SH-SY5Y cells, in which the resting $Ca^{2+}$ concentration was relatively lower than that of RA-induced cells. After the RA induction, immunostaining was seen in both the nucleus and cytoplasm. In the RA-induced differentiated SH-SY5Y cells, CacyBP was phosphorylated on serine residue(s), while it existed in a dephosphorylated form in normal (uninduced) cells. Thus, the phosphorylation of CacyBP occurs when it is translocated to the nuclear region. The translocation of CacyBP during the RA-induced differentiation of SH-SY5Y cells suggested that this protein might play a role in neuronal differentiation.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.6 no.2
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• pp.34-41
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• 2010

This work is concerned with the analysis of stress corrosion cracking(SCC) behavior of Alloy 600 nozzle penetration mock-up according to a residual stress induced by a dissimilar metal welding(DMW) in a nuclear reactor pressure vessel. The effects of the dimension and materials of the nozzle penetration on the deformation and the residual stress induced by DMW were investigated using a finite element analysis(FEA). The inner diameter(ID) change of the nozzle by DMW and its dependance on the design variables, calculated by FEA, were well consistent with those measured from the mock-up. Accelerated SCC tests were performed for three mock-ups with different wall thicknesses in a highly acidic solution to investigate mainly the effect of the residual stress on the SCC behavior of Alloy 600 nozzle. From a destructive examination of the mock-up after the tests, the SCC behavior of the nozzle was fairly related with the residual stress induced by DMW : axial cracks were found in the ID surface of the nozzle within the J-weld region where the highest tensile hoop stress was predicted by FEA, while circumferential cracks were observed beyond both J-weld root and toe where the highest tensile axial stress was expected.

• Journal of Arbitration Studies
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• v.14 no.1
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• pp.377-413
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• 2004

North Korea and South Korea agreed to refer their investment disputes to arbitration by adopting' Agreed Minutes on Procedures of Settlement of Commercial Disputes' on 16th December 2000. According to the Agreed Minutes, the two Koreas were to establish an arbitration commission within 6 months after the Agreed Minutes had been signed. In 2002, North Korea enacted laws to draw interest of foreign tourists to Mountain Kumgang and to boost investment into the region of Kaesung as it provided in those laws that commercial disputes should be settled by arbitration or judicial procedures. In October 2003, the two Koreas succeeded in adopting another Agreed Minutes as to the establishment and functioning of North-South Arbitration Commission. The fact that the two Koreas have agreed to establish an arbitration commission is meaningful since they are leading their lives quite differently in political, social, and economic sense for more than a half century. Although there still remain doubts as to the North Korean policy on nuclear matters, an arbitration commission could be a cornerstone for the set-up of the dispute settlement system between the two Koreas and a great help for investors from South Korea to pursue their possible legal claims as North Korea is eager to invite South Korean businessmen and other foreign investors to invest in its special economic areas. According to the Agreed Minutes of 2003, the two Koreas are going to adopt procedural rules for the arbitration commission. It will be a great challenge for them to agree on specific issues as to the operation of the arbitration commission. They have to set up a rester of arbitrators respectively and may have to enact or revise their own arbitration laws and rules reflecting the Agreed Minutes of 2000 and 2003. It is quite welcome that the two Koreas have agreed to set up an arbitration commission rather than resort to political or diplomatic means to settle their disputes. The success of the arbitration system between the two Koreas will make sure the safety of investment environment in the northen part of the Korean Peninsula and will bring the peace to the Korean peninsula earlier than expected.

• Korean Journal of Pharmacognosy
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• v.53 no.3
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• pp.153-161
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• 2022

Cotoneaster mongolicus Pojark. (CM), in the family Rosaceae is an endemic plant to the Mongolian region (its name: Moнroл чapraй). In Mongolia, Cotoneaster species as a crude drug is mainly used for inflammatory diseases, diarrhea, and stomach indigestion. In this study, we evaluated the gastro-protective activity underlying mechanism of CM. For in vivo experiments, mice were divided into 5 groups; normal mice (Normal), gastritis mice (Control), gastritis mice treated with sucralfate 10 mg/kg (SC), gastritis mice treated with CM 100 mg/kg (CML), gastritis mice treated with CM 200 mg/kg (CMH). Gastritis was provoked by HCl/ethanol (60% ethanol in 150 mM HCl). After oral administration of each drug, HCl/ethanol was orally administered 90 mins later to induce gastritis. CM alleviated the damage to the gastric mucosa caused. As a result of confirming the expression of protein in gastric tissue through western blot, CM significantly reduced the expression of NF-κB activated due to gastritis. Also, it significantly modulated the Nrf2-Keap1 pathway. These results indicate that CM not only inhibits the nuclear metastasis of NF-𝛋B but also modulates the Nrf2-Keap1 pathway to relieve inflammation of the gastric mucosa.