• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.267-268
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• 2018

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.444-445
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• 2018

• Journal of Life Science
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• v.28 no.2
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• pp.257-264
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• 2018

The YrdC superfamily is a group of proteins that are highly conserved in almost all organisms sequenced so far. YrdC in Escherichia coli was suggested to be involved in ribosome biogenesis, translation termination, cold adaptation, and threonylcarbamoyl adenosine formation in tRNA. In this study, to unambiguously demonstrate that yrdC is essential in E. coli, we constructed two yrdC mutant strains of E. coli and examined their phenotypes. In the temperature-sensitive yrdC mutant strain, cell growth stopped almost immediately under nonpermissive conditions and it appeared to accumulate 16S ribosomal RNA precursors without significant accumulation of 30S ribosomal subunits. We also cloned yeast and human homologs and demonstrated that they complement the E. coli yrdC-deletion strain. By mutational study, we demonstrated that the concave surface in the middle of the YrdC protein plays an important role in E. coli, yeast, and human versions. By comparison of two yrdC-deletion strains, we also unambiguously demonstrated that yrdC is essential for viability in E. coli and that the functions of its yeast and human homologs overlap with that of E. coli YrdC.

• Journal of Information Technology Services
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• v.22 no.1
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• pp.75-93
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• 2023

The game industry has grown not only by combining them with various technologies also introducing new types of business models such as P2P, F2P, and P2W. Furthermore, games which implemented X2E model with blockchain technology are recently in the spotlight of the public attention. As domestic game companies have also prospect the blockchain games feasible, they are seeking ways to expand their global market share by strengthening the X2E model. Hence, by carrying this new business model out, it is expected to diversify their global revenue stream, which was previously confined to Asia region. This study analyzed the case of companies that have implemented the P2E and C2E models in order to suggest the direction of development for the game platform in Web 3.0 era. The cases of P2E game platform, which constitute of Axie Infinity and Mir 4, encompass the compensation structure, the stabilization mechanism of the in-game token economy, and future strategies regarding blockchain gaming. Likewise, the platform structure, business model, and future growth potential was discussed in terms of C2E scheme, focusing on the ZEPETO and Roblox cases. Based on the above case analysis, this study attempted to provide information on the current limitations and development directions of the P2E and C2E platforms. The current limitations in legal and industrial aspects should be addressed to facilitate the blooming of blockchain and P2E game industry. In addition, the necessity of not only social support also improvement on the technology and social stigma of full-time creators is ought to be emphasized in an effort to encourage the development of C2E platforms.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.545-551
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• 2005

A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins), vitamin C-, or vitamin E-supplemented and combined supplementation of the two vitamins. After a tenday-adaptation period at 25$^{\circ}C$, the ambient temperature was kept at 32$^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (p<0.05). However, egg quality parameters such as egg weight, specific gravity, shell thickness, SWUSA, puncture force and shell breaking strength from the birds fed the diet with the combined vitamins C and E were significantly improved over those of the control group during the heat stress period (p<0.05). The hens fed the vitamin C diet improved tibia breaking strength (37.16 kg), statistically higher than the birds fed the control and the vitamin E diets (p<0.05). The hens fed the control diet showed higher serum corticosterone levels, a mean of 5.97 ng/ml, than those of the other treatments (p<0.05). The heat stress resulted in elevated heterophils and decreased lymphocytes in serum, increasing the H/L ratios for all the treatments. However, the increases in H/L ratios were alleviated by feeding the diets containing vitamin C alone or together with vitamin E, although there were no significant differences in the ratio between the two groups (p<0.05). In conclusion, vitamins C (200 mg/kg) and/or E (250 mg/kg) supplemented to the diets for broiler breeder hens could prevent drops in egg shell quality and tibia bone strength under highly stressful environmental temperatures.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.143-149
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• 2015

This experiment was conducted to evaluate the synergistic effects of vitamin C and E on methylmercury (MeHg) toxicity in juvenile olive flounder Paralichthys olivaceus. In a $3{\times}3$ factorial design, 9 experimental diets containing three different vitamin C (0, 200 or 400 mg/kg diet in the form of l-ascorbyl-2-monophosphate) and vitamin E (0, 100 or 200 mg/kg diet in the form of dl-${\alpha}$-tocopheryl acetate) levels with the Hg toxicity level (20 mg/kg diet in the form of MeHg) were formulated. Triplicate groups of fish averaging $2.3{\pm}0.05g(mean{\pm}SD)$ were fed one of the 9 diets in a flow through system for 8 weeks. Fish fed 400 mg vitamin C/kg diet with 100 or 200 mg vitamin E/kg diet showed significantly (P < 0.05) higher weight gain (WG) than did fish fed the other diets. Fish fed 400 mg vitamin C/kg diet at all vitamin E levels and those which fed vitamin C and E equally at a rate of 200 mg/kg diet showed significantly (P < 0.05) higher feed efficiency (FE), specific growth rate (SGR) and protein efficiency ratio (PER) than did fish fed the other diets. Fish fed 200 and 400 mg vitamin C/kg diet exhibited significantly (P < 0.05) lower Hg concentration in their muscle as well as kidney than did fish fed the other diets. Therefore, these results clearly indicated that the synergistic effects of these two vitamins on MeHg toxicity by supplementing dietary vitamin C (200 and 400 mg/kg diet) with vitamin E (100 and 200 mg/kg diet) in juvenile olive flounder.

• Kidney Research and Clinical Practice
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• v.37 no.4
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• pp.338-346
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• 2018

Background: The most common cause of acute kidney injury (AKI) in pregnancy is preeclampsia. Serum cystatin C (CysC) is a potential biomarker of early kidney damage as its levels are not disturbed by volume status changes in pregnancy, and serum CysC levels could serve as a replacement for conventionally used creatinine. In this study, we investigated the serum levels of CysC in severe preeclampsia cases and the associations between CysC levels and poor obstetric outcomes. Methods: Our cohort included severe preeclampsia patients with a normal serum creatinine level. Creatinine was measured to calculate estimated glomerular filtration rate (eGFR) based on the Cockcroft and Gault, Modification of Diet in Renal Disease Study (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations, while CysC was measured to calculated eGFR based on a CysC-based equation. We then evaluated the correlations between serum CysC level, eGFR, and obstetric outcomes. Results: Twenty-six patients were evaluated of which 38.5% delivered preterm and 30.8% had low-birth weight babies. Unlike creatinine-based eGFR and CysC-based eGFR, serum CysC demonstrate significant negative correlation with gestational age. Receiver operating characteristic curve analysis indicated that serum CysC is a potential biomarker of preterm delivery with a cut-off serum level of 1.48 mg/L with 80% sensitivity and 75% specificity. Conclusion: GFR estimation using CysC is likely to be inaccurate in pregnancy. However, we found a significant correlation between preterm delivery and serum CysC level. Our results suggest that serum CysC level has the potential to predict preterm delivery in severe preeclampsia patients.

• Animal cells and systems
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• v.4 no.1
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• pp.71-76
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• 2000

The aim of this study was to investigate expression patterns of the prolactin (PRL) and c-fos genes by 17$\beta$-estradiol (17$\beta$-E) and stress in the mouse pituitary. In the pituitary, the levels of PRL mRNA were found high with some fluctuation at 30, 50, and 90 min whereas the levels of PRL mRNA were low at 120 min when ovariectomized female mice were injected with 17$\beta$-E or vehicle. PRL mRNA levels began to increase again at 4 h and remained high up to 24 h only in the 17$\beta$-E- treated mice. The overall changes in c-fos mRNA by 17$\beta$-E were very similar to those in PRL mRNA in the pituitary. Subsequent study revealed that these high initial levels of PRL and c-fos mRNAs were caused by stress during Injection, not by 17$\beta$-E, since vehicle injection alone into the ovariectomized mice could increase the levels of PRL and c-fos mRNAs. The stress-induced elevations of PRL and c-fos mRNAs were inhibited by bromocriptin, a dopamine agonist, suggesting that the dopaminergic system is involved in the action route of injection stress. In addition, the induced levels of c-fos mRNA by 17$\beta$-E and stress in the pituitary were very low compared with those in the uterus. The time course changes in c-fos mRNA level were different between the pituitary and uterus. Taken together, these data indicate that PRL and c-tos gene expression in the pituitary are regulated by 17$\beta$-E and stress in a parallel manner, supporting the notion that c-Fos plays a role in regulation of PRL gene expression.

• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.45-51
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• 1991

Inserting the $cI_{857}$ structural gene in the downstream of the tac promoter for the overproduction of $cI_{857}$ repressor protein was studied. DNA fragment containing $cI_{857}$ ; repressor gene was amplified by using plasmid pUC12, and partially digested with HphI. Only the $cI_{857}$ structural gene isolated was inserted in the downstream of the tac promoter. Plasmid pDR540- $cI_{857}$ having the tuc promoter-$cI_{857}$ structural gene insert could be isolated by the immunity of cells resistant at $30^{\circ}C$ and cell lysis at $42^{\circ}C$ to $\lambda$ phage $cI_{90}$. The amount of $cI_{857}$ repressor as 17% of total cellular protein were produced by using general E. coli as well as $lacI^q$ JM103 having this plasmid.

• Journal of Aquaculture
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• v.5 no.2
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• pp.143-155
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• 1992

Effects of vitamin E, C and/or glycyrrhizin in the artificially oxidized feed on the growth and on the resistance aganist Edwardsiella tarda infection to Nile tilapia, Oreochromis niloticus, were examined. The thiobarbitric acid (TBA) values of the oxidized feed were $80\~88$ mg/kg. The fingerling fish were fed the oxidized feed with or without the mixture of vitamin E (50 mg), C (60 mg) and/or glycyrrhizin ($25\~200$ mg) per 100 g of the feed for 7 weeks. The fish fed the oxidized feed with vitamin E, C and/or glycyrrhizin showed better growth than the fish fed the oxidized feed only. But growth rates among the fish fed different amount of vitamins or glycyrrhizin mixed feed were not different. Glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels in the serum increased only in the fish which were fed oxidized feed without vitamin E, C and/or glycyrrhizin. With the fish artificially infected with E. tarda: they showed low survival rate when fed oxidized feed and oxidized feed plus 25 mg glycyrrhizin per 100 g feed. The fish fed oxidized feed plus vitiamin E, C and/or glycyrrhizin ($50\~200$ mg/100 g), showed higher survival. These results show that the supplementation of oxidized lipids depress the growth and liver activity, while the addition of vitamin E, C and/or glycyrrhizin in the diet accelerated the growth, liver activity, and the resistance to E. tarda infection.