• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.542-549
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• 2018

In this study BGn-incorporated non-fluoride release of pit and fissure sealant $Concise^{TM}$ was developed to improve the mechanical properties and promote antibacterial effect of fit and fissure sealant with the original material. The mechanical properties and antibacterial activity of BGn incorporating vary-ing amounts bioactive glass nano particles(BGn) (0,0.5,1.0 and 2.0 wt% in sealant) were characterized composition of the resulting were investigated. The solubility to aid absorption was calculated by weighing specimens with a diameter of 10 mm and a thickness of 2 mm according to ISO 4049 (2009). The antimicrobial effect was evaluated using three strains of S. mutans, S. aureus and E. coli. The absorbance of the test results was as high as the addition of BGn increased, and the lower the solubility as the solubility was added(p<0.05). Adhesion experiment results S. mutans in contrast to the control group $Concise^{TM}$, BGn-added experimental group showed a somewhat lower adherent surface but no statistically significant difference was observed (p<0.05). However S. aureus and E. coli statistical analysis indicated a significant difference for antibacterial agents between control and BGn containing(p<0.05). It seems that this BGn proved that even a antibacterial effect was demonstrated. Therefore, it was suggest that the additional effects of BGn and research on a wide range of substances.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.209-214
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• 2017

Most of the present potential transformers of train vehicles are of the oil-type filled with insulating oil and are susceptible to problems such as explosion due to the increase in the internal pressure during train operation and poor reliability near the end of their life cycle. As a solution to this problem, it is necessary to develop a molded dry-type potential transformer with excellent pressure-resistance performance using insulating resin. In order to localize the product, the Korea Railroad Research Institute has been developing a molded dry-type potential transformer. As part of this research, it is necessary to analyze the vibration characteristics of the developed product and to check the transformer performance in a vibration environment. In this study, a resonance test and simulated long-term life test of the developed product were conducted according to the KS R 9144 and IEC 61373 standards, respectively, which are vibration test methods for railway vehicle parts. Their natural frequencies were analyzed by comparing the results of the numerical modal analysis and resonance test, in order to confirm their adherence to the standards. Also, the performance test after the simulated long-term life test confirmed that the operation of the developed transformer was not problematic even in a long-time vibration environment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.6
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• pp.343-353
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• 2012

Objectives: This aim of this study was to effectively isolate mesenchymal stem cells (hSMSCs) from human submandibular skin tissues (termed hSMSCs) and evaluate their characteristics. These hSMSCs were then chemically induced to the neuronal lineage and analyzed for their neurogenic characteristics in vitro. Materials and Methods: Submandibular skin tissues were harvested from four adult patients and cultured in stem cell media. Isolated hSMSCs were evaluated for their multipotency and other stem cell characteristics. These cells were differentiated into neuronal cells with a chemical induction protocol. During the neuronal induction of hSMSCs, morphological changes and the expression of neuron-specific proteins (by fluorescence-activated cell sorting [FACS]) were evaluated. Results: The hSMSCs showed plate-adherence, fibroblast-like growth, expression of the stem-cell transcription factors Oct 4 and Nanog, and positive staining for mesenchymal stem cell (MSC) marker proteins (CD29, CD44, CD90, CD105, and vimentin) and a neural precursor marker (nestin). Moreover, the hSMSCs in this study were successfully differentiated into multiple mesenchymal lineages, including osteocytes, adipocytes, and chondrocytes. Neuron-like cell morphology and various neural markers were highly visible six hours after the neuronal induction of hSMSCs, but their neuron-like characteristics disappeared over time (24-48 hrs). Interestingly, when the chemical induction medium was changed to Dulbecco's Modified Eagle Medium (DMEM) supplemented with fetal bovine serum (FBS), the differentiated cells returned to their hSMSC morphology, and their cell number increased. These results indicate that chemically induced neuron-like cells should not be considered true nerve cells. Conclusion: Isolated hSMSCs have MSC characteristics and express a neural precursor marker, suggesting that human skin is a source of stem cells. However, the in vitro chemical neuronal induction of hSMSC does not produce long-lasting nerve cells and more studies are required before their use in nerve-tissue transplants.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup1
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• pp.17-23
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• 2016

The aim of this paper is to report the rate of current and ever cigarette smoking and explore correlates of current cigarette smoking among adolescents aged 13-15 in Viet Nam. This analysis was derived from GYTS survey, which comprised of 3,430 adolescents aged 13-15, conducted in 2014 in 13 cities and provinces of Viet Nam. We calculated the weighted rates of current and ever cigarette smoking and reported patterns of smoking behavior. We also performed logistic regression to explore correlates of current cigarette smoking behavior. The weighted rate of ever cigarette smoking was 9.5% (95% confidence interval (CI): 8.5 %-10.5%), in which the weighted rate among males (15.4%; 95% CI: 13.6%-17.0%) was higher than that among females (4.2%; 95% CI: 3.3%-5.1%). The weighted rate of current cigarette smoking was relatively low at 2.5% (95%CI: 2.0%-3.0%) with higher weighted rate among males (4.9%; 95% CI: 3.8%-5.9%) compared to the corresponding figure among females (0.2%; 95% CI: 0.0 %-0.5%). Current cigarette smoking was significantly higher among males than females, in students aged 15 versus 13 years old, and in students who had several or all close friends smoking and students with daily observation of smoking at school. For greater smoking reduction outcomes, we recommend that tobacco interventions for adolescents should consider targeting more male students at older ages, establish stricter adherence to school-based banning of cigarette smoking, engage both smoking and nonsmoking adolescents and empower adolescents to resist peer smoking influence as well as changing their norms or beliefs towards smoking benefits.

• Korean Journal of Social Welfare
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• v.67 no.2
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• pp.259-284
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• 2015

This case study is to identify the role and strategies of think tanks in Britain which have shown institutional initiative in global welfare paradigm such as the establishment of welfare state, Thatcherism, and the Third Way. Fabian Society, Institute of Economic Affairs (IEA), Institute for Public Policy Research (IPPR), and Policy Exchange (PX) were selected for the research, and seven staff members from these think tanks were interviewed while their relevant publications were gathered and analyzed. As a result, the role of each think tank in welfare paradigm change were presented as well as strategic similarities were found: distinguished idea on the relationship between economy and welfare, adherence to independence based on their values, and strategic communication with diverse routs. However, there was also strategic difference between the first round and the second in the history. In the first round between Fabian Society and IEA, building a space for discussion based on new paradigm was the key, while in the second round between IPPR and PX, producing a set of alternative policies was the main task for them. This British example may provide useful implication to Korea, in which political debate on social welfare still just focus on individual pledges competition and the role of think tank is highly limited.

• Journal of the Korean Ceramic Society
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• v.39 no.6
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• pp.582-588
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• 2002

IrO$_2$-RuO$_2$ films were deposited on plasma sprayed TiO$_2$ buffer layer above Ti metal by sol-gel and dip-coating method. Organic vehicle (ethyl cellulose and $\alpha$-terpineol) and glass frit were added to improve adherence of the coatings. Taguchi method and L$_{18}$ (2$^1$$\times$3$^{7}$ ) orthogonal arrays were evalvated in terms of current density to determine the optimal combination of levels of factors that best satisfy the bigger is better quality characteristic. The observed conditions were as fellows: ethyl cellulose (100 cp), drying temperature and time (17$0^{\circ}C$,20 min), heat treatment temperature and time (75$0^{\circ}C$,10 min), the weight ratio of IrO$_2$-RuO/powders to glass frit (99:5), final heat treatment time (120 min) and flow rate of air (5 sccm), respectively. ANOVA analysis suggested that the influence of the factors within $\alpha$= 0.1 was significant with a 90% confidence level.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.5
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• pp.698-713
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• 1999

Adherence of Candida albicans(C. albicans) to the surface of a denture is believed to be an initial and essential step in the formation of denture-induced stematitis. Previous studies have provided enormous infomation on the relationship between composition of palatine gland/parotid saliva and upper denture stomatitis. Relatively little information is available on the correlation between lower denture stomatitis and sublingual-submandibular ( SLSM ) saliva. The plaque samples were collected from the two sites($100mm^2$) on the inner surface of lower partial denture corresponding to the stematitis and healthy region of the lower partial dentures of 12 denture stomatitis patients and 6 nor-mal persons who wore lower partial dentures. The samples were plated to isolate C. albicans on a selective Saboraud's dextrose agar plate and the isolates were identified by germ tube test and gram staining. The subjects were divided into group I (stomatitis with C. albican), group II (lesion without C. albicans), group III (no lesion but C. albicans), and group IV (normal and healthy denture wearer). Individual SLSM saliva($20{\mu}g$ of protein) was analyzed by SDS-PAGE (SDS -poly-acrylamide gel electrophoresis) with Coomassie brilliant blue and PAS(Periodic Acid Schinff) stain-ing. The salivary proteins separated in the polyacryamide gels were subjected to immunoblot anaysis using anti-lactoferrin, anti-sIgA, and anti-secretory component of sIgA. In this study using custom made acrylic denture resin beads(5mm in diameter) coated with stimulated individual SLSM saliva, the binding ability of individual C. albicans strains to the beads was observed. Levels of C, albicans adhered to the acrylic resin beads were determined by measuring the optical density of the bound C. albicans to the beads at 580nm. The results showed that a higher number of C. albicans was observed in the lesion site than healthy site. The saliva of group I contained more high molecular weight glycoprotein(mucin, MGI) as compared to group II, III and IV. And lactoferrin and sIgA affected to the binding ability of C. albicans to acylic resin beads. Binding ability of individual C. albicans to the acrylic resin coated with respective individual saliva was found to be greater in group I than the other 3 groups. And when bound cells of C. albicans isolated from individual subject #2 to the saliva coated beads were used binding ability of subject #2 saliva coated beads was founed to be greater than the other sutjects. These results suggested that denture induced stomatitis is related to individual patient's salivary protein composition, especially MG-1. Future studies will be directed toward saliva exam-ination of patients who have general disease and analysis of pellicles formed on prosthesis with respect to oral disease.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.71-81
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• 2004

Peri-implantitis could be the result of biomechanical and occlusal overload as well as microbiologic invasion. The dental implant may be more susceptible to dental plaque than the natural tooth, as the predictability of a stable soft tissue attachment complex has not yet been confirmed. With the development of peri-implantitis, the implant surface would be exposed to the oral environment and becomes coated with bacteria. The objective of therapy for this condition is to regain integration of the implant with bone. Since fibroblast adherence to surfaces is impeded by endotoxin, it would seem that decontamination would be desirable to obtain maximum osseointegration. The purpose of this study was to determine whether various chemotherapeutic and mechanical treatments(distilled water, air-powder abrasive, hypersaturated citric acid, tetracycline) can detoxify contaminated titanium implant surface by means of kinetic LAL test. Experimental rough surface titanium disks were fabricated. All of them were divided into two groups(A.a group and P.g group) and each contaminated by A. actinomycetemcomitans and P. gingivalis suspension. Contaminated disks were treated with distilled water, air-powder abrasive, citric acid and tetracycline, and then all disks were placed into LPS-free water for elution. The results were as follows : 1. In A.a group, LPS elute level of all test groups were significantly lower than control group(p<0.05). 2. In A.a group, LPS elute level of test 2, test 3 and test4 groups were significantly lower than that of control group(p<0.05). But, among the test 2, test 3, test4 groups, the significant differences were not detected. 3. In P.g group, LPS elute level of test 2, test 3 and test 4 groups were lower than that of control group(p<0.05). But, among the test groups, the significant differences were not detected. From the result of this study, it would be concluded that air-powder abrasive, hypersaturated citric acid and tetracycline treatments may be effective at reducing endotoxin level on rough titanium implant surfaces, and can be clinically used. But the treatments in peri-implantitis differentially impact osseointegration making one method clinically superior. To gain this knowledges, further molecular biologic and histopathologic studies should be developed.

• Journal of the Korean Society of Costume
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• v.31
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• pp.61-73
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• 1997

Kon-myuh was worn by the ancient Chinese and Korean rulers as ceremonial dress during special rituals such as worshipping heaven and ancestors marriage or funerals. kon-myun consists of two major parts-Myun and kon-bok (the main bodypiece) as well as other articles of clothing(skirt footgear etc), There were regulations set in ancient books describing in detail the make of the kon-myun number of ryu and symbol to be used all which applied to each ruler depending on rank and status. This study is aimed at examining the consistency of the korean and Chinese in following the regula-tions as seen in relics which have been recovered from the past. Based on historical findings it seems that Korean Kon-myun came to Korea from China during the Three Kingdoms period. It was also worn in the Koryo and Chosun Dynas-ties and the Taehan Empire. In studying Konmyun in Korea the researcher studied a book from the early Chosun dynasty, Kukjo-oryeuiseory and a book from the late Chosun Dynasty Kukjo-sangrye-bopyun to find the guidelines and rules applying to the Kon-myun tradition. Slight difference were found across time in the supplementary articles of clothing as seen in Uigwe Pokwan-doseols explanations and drawings of Kon-myun. The researcher used uigwes of funerals of kings of the Chosun Dynasty and observed change over this period of time. However there was a clear consist-ency: the king's Kon-myun consisted of 9ryu-myun 9chang-bok while that of the prince consisted of 8ryu-myun 7chang-bok. For the Taechan Empire the researcher used Tae-han Yae-jun which shows the emperor's kon-myun to have consisted of 12ryu-myun 12chang-bok. To study how the regulations were put into practice relics were uncovered from the periods being studied. A portrait of King Ik-Jong remnants from King Ko-jong's Kon-bok and a photograph of Emperor Sun-jong all were in close adherence to the regulations outlined in the books. In China Kon-myun was worn by emperors from the Han to the Ching Dynastices. The researcher investigated Kon-myun es-pecially in the Ming Dynasty. The Kon-myun regulations as read in Tai-ming-hui-chan changed through all four periods. To study the faithfulness of practice to low Ding-ling the tomb of Emperor Shin-jong who ruled during a period of the Ming Dynasty was unearthed and the remains of the Emperor's Kon-myun were analyzed. The Kon-myun consisted of 12ryu-myuh 18chang-bok and there were other differences I color symbols and wearing method when compared to the regulations. It can be concluded that the Chinese Kon-myun tradition was not in strict adher-ence to the regulations established by law books. This is in contrast to the Korean Kon-myun tradition which showed little devi-ation. Further study is needed to understand why there was this difference in tradition and ritual.

• Progress in Medical Physics
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• v.26 no.4
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• pp.273-279
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• 2015

Recently, medical devices for a smart health development and dissemination are becoming increasingly frequent use of devices and their's thermal stability, durability, the external splendors are required. Industrial demand for smart health medical devices uses high-functioning electrodeposition technology that expressed pearl-like feeling is rapidly increasing. Generally, pearl powder is added to electrodeposition pigment in order to form a coating which shows pearl-like feeling. On the other hand, the electrodeposition technology for the smart health medical devices uses a new method that can express pearl-like feeling without using pearl powder. In this study, we was tried to find out the most appropriate texture formation, the right dilution recipe. We've tried various ptoportions of pigments (ED-600, ED-600S, ED-MX, ED-M). As a result, we found out that ED-600 and ED-MX (15% solid) in appropriate concentration showed the best adherence rate. By several samples tests and experiments which include washing the fixed pigment in various temperature levels ($20{\sim}40^{\circ}C$) and drying, we were able to get the best results in drying condition of $180{\pm}10^{\circ}C$ and $30{\pm}5min$. The research showed that it is mush more competitive and cost effective to use the new method that produces natural pearl-like feeling on the surface than to add pearl powder to high-functioning electrodeposition pigment, which is a method that has been used for the smart health medical devices so far.