• Restorative Dentistry and Endodontics
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• v.17 no.2
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• pp.263-286
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• 1992

This study was performed to evaluate and compare the cytotoxic effects of five root canal sealers to several different cell lines. Five root canal sealers were AH-26, N2, Sealapex, Tubliseal, and Vitapex. Each sealers were mixed according to the manufacturer's instructions, and culture media were added to each sealers immediately after mixing (the immediate group) and after three days (the third day group) and seven days (the seventh day group) respectively. And every sealer solutions were diluted to 1:1, 1:2, 1:3 and 1:4. Three different permanent cell lines (HEp-2, McCoy, MRC-S) and human gingival fibroblasts and mononuclear cells were challenged by each sealer solution and the cytopathic effects were evaluated using MTT-ELISA, MTT-microscopy, and lactate dehydrogenase (LD) activity. The results were as follows: 1. In HEp-2 and MRC-5 cells, Vitapex was the least cytotoxic sealers. 2. AH-26 showed mild cytotoxic effects to HEp-2, gingival fibroblast and mononuclear cells. 3. N2 was the most toxic sealer to gingival fibroblast and it showed relatively strong cytotoxicity to HEp-2, McCoy and MRC-S cells. 4. Tubliseal showed strong cytotoxic effects to HEp-2, McCoy, MRC-S, and mononuclear cells. 5. Sealapex showed strong cytotoxic effect to HEp-2, McCoy, and gingival fibroblasts.

• Molecules and Cells
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• v.20 no.2
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• pp.280-287
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• 2005

The insulin-mediated Ras/mitogen-activated protein (MAP) kinase cascade was examined in SK-N-BE(2) and PC12 cells, which can and cannot produce reactive oxygen species (ROS), respectively. Tyrosine phosphorylation of the insulin receptor and insulin receptor substrate 1 (IRS-1) was much lower in SK-N-BE(2) cells than in PC12 cells when the cells were treated with insulin. The insulin-mediated interaction of IRS-1 with Grb2 was observed in PC12 but not in SK-N-BE(2) cells. Moreover, the activity of extracellular-signal-related kinase (ERK) was much lower in SK-N-BE(2) than in PC12 cells when the cells were treated with insulin. Application of exogenous $H_2O_2$ caused increased tyrosine phosphorylation and Grb2 binding to IRS-1 in SK-N-BE(2) cells, while exposure to an $H_2O_2$ scavenger (N-acetylcysteine) or to a phophatidylinositol-3 kinase inhibitor (wortmannin), and expression of a dominant negative Rac1, decreased the activation of ERK in insulin-stimulated PC12 cells. These results indicate that the transient increase of ROS is needed to activate ERK in insulin-mediated signaling and that an inability to generate ROS is the reason for the insulin insensitivity of SK-N-BE(2) cells.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.4
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• pp.373-382
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• 2000

Individual genetic susceptibilities to cancers may result from several factors including differences in xenobiotics metabolism to chemical carcinogens, DNA repair, altered oncogenes and suppressor genes, and environmental carcinogen exposures. Among them, genetic polymorphisms of metabolizing enzymes to chemical carcinogens have been recognized as a major important host factors in human cancers. They have two main types of enzymes: the phase I cytochrome P-450 mediating enzymes (CYPs) and phase II conjugating enzymes. The purpose of this study is to determine the frequencies of genotypes of phase I (CYP1A1 and CYP2E1) and phase II (NAT2) metabolizing enzymes in healthy control and head and neck cancer patients of Korean and to identify the relative high risk genotypes of these metabolizing enzymes to head and neck cancer in Korean. The author has analyzed 132 head and neck cancer patients and 113 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results were as following; 1. The frequencies of genotypes of CYP1A1, CYP2E1 and NAT2 in healthy control were as following; CYP1A1 exon 7 polymorphism; Ile/Ile: Ile/Val: Val/Val = 59.3%: 36.3%: 4.4% CYP2E1 Pst I polymorphism, C1/C1: C1/C2: C2/C2 = 61.1%: 32.1%: 6.2% NAT2 polymorphism; F/F: F/S: S/S = 43.4%: 48.7%: 8.0% 2. In analysis of phase I enzyme, Val/Val genotype in CYP1A1 exon 7 polymorphism and C2/C2 genotype in CYP2E1 Pst I polymorphism were associated with relative high risks to head and neck cancers (Odds' ratio: 2.09 and 1.37, respectively). 3. Among the genotypes of NAT2 enzyme polymorphism, S/S genotype of NAT2 enzyme had 1.03 times of relative risk to head and neck cancers. 4. In combined genotyping of CYP1A1, CYP2E1, and NAT2 enzymes polymorphisms, the patients with Val/Val and C1/C1, C2/C2 and fast acetylator, and Val/Val and fast acetylator had higher relative risks than the patients with each baseline of combined genotypes (Odds' ratio: 2.82, 1.98 and 2.1, respectively). These results suggest the combined genotypes of Val/Val and C1/C1, C2/C2 and fast acetylator, and Val/Val and fast acetylator were more susceptible to head and neck cancers in Korean. And genotyping of metabolizing enzymes could be useful for predicting individual susceptibility to head and neck cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1015-1018
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• 2016

Background: Overexpression or amplification of human epidermal growth factor receptor-2 (HER2) is associated with grade of malignancy and a poor prognosis in breast cancer (BC). The aim of this study was to evaluate of value of HER2 as a prognostic marker, and to analyze associations with common histopathological parameters in BC cases. Materials and Methods: Between of 2007 to 2014, 260 patients with BC referred to Oncology Clinic provided cancer tissue samples which underwent immunohistochemistry (IHC) for markers. ER and PR positivity was defined as ${\geq}10%$ positive tumor cells with nuclear staining. HER2-positive was defined as either HER2 gene amplification by fluorescent in situ hybridization (FISH) or scored as 3+ by IHC. For HER2 (2+), FISH was performed to determine HER2 positivity. Results: The mean age at diagnosis for the patients with HER2-negative was significantly higher than in HER2-positive cases. Also, there were significant correlations between histological grade, nuclear grade, lymph node metastasis, tumor size, ER status, PR status, p53 overexpression and Ki-67 index with HER2 expression. HER2-negative lesions were of higher grade and more likely to be ER-negative, PR-negative, p53-positive, lymph node metastasis, with a tumor size<2cm and also $Ki-67{\geq}20%$ as compared to the HER2-positive group. Conclusions: Contrary to the results of other studies, HER2-positive tumors in our study had a lower Ki-67 index and were p53-positive. Also, Ki-67 proliferation index ${\geq}20%$ in more studies was associated with p53-positive.Therefore, tumors which are HER2-positive and have a Ki-$67{\geq}20%$ had a more aggressive behavior compared to HER2-positive and Ki-67<20% lesions.

• Journal of the Korean Ceramic Society
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• v.30 no.11
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• pp.897-904
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• 1993

CdS doped SiO2 glass coating films which are good candidates for the nonlinear optical materials were prepared by the Sol-Gel method. TEOS, C2H5OH, H2O and HCl were used as starting materials to obtain SiO2 matrix solutions. Then Cd(NO3)2.2H2O and CS(NH2)2 were dissolved into the SiO2 matrix solutions. Coating was performed several times in order to increase the thickness of coated film by the dip-coating method. Then heat treatments were carried out to control the size of CdS microcrystals doped in SiO2 glass matrix with respect to temperatures and times. CdS-doped SiO2 transparent coating films were successfully obtained. CdS crystals were changed from cubic to hexagonal type about $600^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.21 no.4
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• pp.373-381
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• 1984

The coloration of the $Nd_2O_3$ contained $R_2O-BaO-SrO-ZrO_2-SiO_2$ glass added the various amount of $CeO_2$ $MnO_2$, $Fe_2O_3$ and $As_2O_3$ alone or together by the irradiation of X-ray irradiation,. The glasses added $CeO_2$ in proportion to amount were more effective on preventing coloration by X-ray irradiation but the addition of $MnO_2$ produced different color according to the amount of addition. The addition of the $Fe_2O_3$, $TiO_2$ and $As_2O_3$ did not give much effects to the transmission changes of $Nd_2O_3$ contained glass by X-ray irradiation but the glass added $CeO_2$ , $Fe_2O_3$, $TiO_2$ together was most effective to prevent coloration and transmisson changes.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.463-467
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• 2009

Interspecific hybrid plants between Allium cepa L. (2n=2X=16) and A. fistulosum L. (2n=2X=16)and their backcross lines were developed by artificial pollination in order to introduce new desirable characters of A, cepa to A. fistulosum. The 2C nuclear DNA content has been estimated by flow cytometry in 5 Allium fistulosum inbreed lines, 2 interspecific hybrid lines of A. cepa${\times}$A. fistulosum and 34 their backcross lines $BC_1F_1$ to $BC_2F_2$, using propidium iodide (PI) as a fluorescence dye. Estimated 2C DNA values ranged from 22.2 pg to 23.7 pg in 5 A. fistulosum inbreed lines, 37.9 pg in F1 hybrid between A. cepa and A. fistulosum, 24.3 pg to 27.3 pg in 7 backcross lines in $BC_1F_1$, 21.9 pg to 24.4 pg in 9 $BC_1F_2$, 22.9 pg to 25.1 pg in 14 $BC_2F_1$, 22.6 pg to 23.4 pg in 4 $BC_2F_2$. This study showed mean 2C nuclear DNA content of $F_1$ hybrid was higher than their backcross progeny lines, while it was lower than female parental line, A. cepa (2C DNA=33.2 pg). Mean 2C DNA content of backcross lines, $BC_1F_1$ to $BC_2F_2$ was not significantly different but their 2C DNA contents in the more progress generation from $BC_1F_1$ to $BC_2F_2$ were reduced.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.3
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• pp.23-28
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• 2022

In order to investigate the degree of sewage sludge dewaterability using Fe(II)/Na₂S₂O₈, STTF, SCST, water content, TS, VS, TB-EPS as carbohydrate and Protein were measured. The dosage of Na₂S₂O₈ was varied from 0.4 to 0.7 mmol/gVS and molar ratio of Fe(II)/Na₂S₂O₈ was varied from 0.5 to 0.7 mol/mol. According to the increase of the dosage of Na₂S₂O₈ and Fe(II)/Na₂S₂O₈ molar ratio, STTF and SCST increased from 1.00 to 15.00 and 4.51, respectively. Water content decreased to 82.6%. TB-EPS as carbohydrate and protein decreasing rate also increased to 37.16% and 57.34%, respectively. Especially, Na₂S₂O₈ 0.6 mmol/gVS and Fe(II)/Na₂S₂O₈ 0.6 mol/mol condition, water content dercreased to 83.1%, STTF and SCST increased to 13.64 and 4.19 which showed the cost effective improvement of dewaterability. It is considered that SO₄^- radical generated by Fe(II)/Na₂S₂O₈ degraded EPS and converted bound water to free water.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.621-634
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• 2010

This study aimed to investigate the effects of dimensions of movie clip (2D vs. 3D), viewing orders (2D ${\to}$ 3D vs. 3D ${\to}$ 2D), and gender difference on participants' subjective fatigue, recognition for the elements in the clips, and arousal level. The results can be summarized as followings. First, subjective fatigue level was higher in the 3D condition than 2D condition, but this tendency was more clear in the 2D ${\to}$ 3D condition than in the 3D ${\to}$ 2D condition. Second, correct recognition rates were significantly higher for 3D than 2D only in the 3D ${\to}$ 2D condition. In particular, male participants showed higher correct recognition rates than female participants in the 3D clip condition, whereas female participants showed higher correct recognition rates than male participants in the 2D clip condition. Third, although 3D clips tended to induce higher level of arousal, this tendency was showed only in the 2D ${\to}$ 3D condition, which implied previous exposure to 2D clip increased the arousal level in following 3D clip than vice versa.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.153-158
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• 2011

This paper presents subjective experimental results to understand how audio should be changed when a video clip is watched in 3D than 2D. This paper divided auditory perceptual information into two categories; distance and azimuth that a sound source contributes mostly, and spaciousness that scene or environment contribute mostly. According to the experiment for distance and azimuth, i.e. sound localization, we found that distance and azimuth of sound sources were magnified when heard with 3D than 2D video. This lead us to conclude 3D sound for localization should be designed to have more distance and azimuth than 2D sound. Also we found 3D sound are preferred to be played with not only 3D video clip but also 2D video clip. According to the experiment for spaciousness, we found people prefer sound with more reverberation when they watch 3D video clips than 2D video clips. This can be understood that 3D video provides more spacial information than 2D video. Those subjective experimental results can help audio engineer familiar with 2D audio to create 3D audio, and be fundamental information of future research to make 2D to 3D audio conversion system. Furthermore when designing 3D broadcasting system with limited bandwidth and with 2D TV supportive, we propose to consider transmitting stereoscopic video, audio with enhanced localization, and metadata for TV sets to generate reverberation for spaciousness.