• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.377-383
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• 2013

This study examined the radiopacity of eight contemporary luting cements by direct digital radiography. Five disc-shaped specimens ($5mm{\times}1mm$) were prepared for each material tested (BisCem, Clearfil SA Luting, Duolink, Maxcem Elite, Multilink Speed, Panavia F 2.0, RelyX Unicem Clicker, V-link). The specimens were radiographed using a Kodak CS 7600 image plate (Carestream Health, Inc., Rochester, NY, USA) and an aluminum step wedge with a range of thicknesses (1.5 to 16.5 mm in 1.5 mm increments) and a 1 mm tooth used as a reference. A dental X-ray machine Kodak 2200 Intraoral X-ray System (Carestream Health, Inc., Rochester, NY, USA), operating at 70 kVp, 4 mA, 0.156 s and a source-to-sample distance of 30 cm, was used. According to international standards, the radiopacity of the specimens was compared with that of an aluminum step wedge using NIH ImageJ software (available at http://rsb.info.nih.gov/ij/).The data was analyzed by ANOVA and a Tukey's post hoc test. Maxcem Elite (5.66) showed the highest radiopacity of all materials, followed in order by Multilink Speed (3.87) and V-link (2.83). The radiopacity of Clearfil SA Luting (1.35), BisCem (1.33), Panavia F 2.0 (1.29) and Duolink (1.10) were between enamel (1.79) and dentin (0.19). RelyX Unicem Clicker (0.71) showed the lowest radiopacity, which was higher than that of dentin. All materials showed a radiopacity above the minimum recommended by the International Organization for Standardization and the American National Standards/American Dental Association with the exception of RelyX Unicem Clicker.

• Restorative Dentistry and Endodontics
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• v.34 no.3
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• pp.184-191
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• 2009

The purpose of this study was to evaluate the physical properties of different self-adhesive resin cements and their shear bond strength on dentin and lithium disilicate ceramic and compare these result with that of conventional resin cement. For this study, four self-adhesive resin cements (Rely-X Unicem, Embrace Wetbond, Mexcem, BisCem), one conventional resin cement (Rely-X ARC) and one restorative resin composite (Z-350) were used. In order to evaluate the physical properties, compressive strength, diametral tensile strength and flexural strength were measured. To evaluate the shear bond strength on dentin, each cement was adhered to buccal dentinal surface of extracted human lower molars. Dentin bonding agent was applied after acid etching for groups of Rely-X ARC and Z-350. In order to evaluate the shear bond strength on ceramic, lithium disilicate glass ceramic (IPS Empress 2) disks were prepared. Only Rely-X ARC and Z-350 groups were pretreated with hydrofluoric acid and silane. And then each resin cement was adhered to ceramic surface in 2 mm diameter. Physical properties and shear bond strengths were measured using a universal testing machine. Results were as follows 1. BisCem showed the lowest compressive strength, diametral tensile strength and flexural strength. (P<0.05) 2. Self-adhesive resin cements showed significantly lower shear bond strength on the dentin and lithium disilicate ceramic than Rely-X ARC and Z-350 (P<0.05) In conclusion, self-adhesive resin cements represent the lower physical properties and shear bond strength than a conventional resin cement.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.11a
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• pp.225-226
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• 2000

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.116-116
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• 1993

전 세계적으로 문제가 되고 있는 질병인 AIDS의 원인 virus인 HIV에 활성이 있는 nucleoside 유도체를 개발하기 위해, 일반적으로 HIV에 활성이 있는 3'-deoxythymidine 유도체의 일종으로써 3'-위치에 hydroxy기 대신에 heterocyclic thio기가 치환된 3'-deoxy-3' -(pyrimidin-2-yl)thio thymidine 및 3'-deoxy-3'-(1-methyltetrazol-5-yl) thiothymidine을 thymidine을 출발물질로 각각 합성하였다. 그러나 이 두 화합물은 항 HIV-1 (CEM cell line)에 대하여 활성이 없었다.

• Honam Mathematical Journal
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• v.40 no.2
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• pp.265-280
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• 2018

In this study, we firstly define equations of motion based on the traditional model Newtonian mechanics in terms of the Frenet frame adapted to the trajectory of the moving particle in Lie groups. Then, we compute energy on the moving particle in resultant force field by using geometrical description of the curvature and torsion of the trajectory belonging to the particle. We also investigate the relation between energy on the moving particle in different force fields and energy on the particle in Frenet vector fields.

• Review of KIISC
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• v.16 no.4
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• pp.59-68
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• 2006

본 논문에서는 소프트웨어 개발 프로세스에서 보안성을 향상시키기 위해, 소프트웨어 개발단계에서 산출되는 문서를 바탕으로 내재되어 있는 취약성을 찾기 위한 체크리스트를 제안한다. 현재 소프트웨어 생명주기내에서 보안성을 지키기 위해서는 설계단계에서의 위험분석 이 요구되며, 이를 확인하기 위한 검증단계가 필수적이다. 따라서, 본고에서는 취약성을 찾는 구체적인 방법으로 ISO/IEC 15408(Common Criteria, 이하 CC)[1]기준의 보안성 평가방법론인 CEM[2]에 기반한 취약성검색을 통해 소프트웨어 설계단계에서 산출되는 개발문서에 대해 검증해야 할 항목을 제시한다.

• Honam Mathematical Journal
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• v.43 no.1
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• pp.17-25
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• 2021

A set D ⊆ V (G) is an independent transversal dominating set of G if D is a dominating set and also intersects every maximum independent set in G. The minimum cardinality of such a set is equal to the transversal domination number, denoted by ��it(G). This paper is devoted to the computation of the independent transversal domination number of some complementary prism.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.425-431
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• 1997

To examine components of Ganoderma lucidum for anti-human immunodeficiency virus (HIV) activity, the aqueous extracts of its basidiocarps were separated into high-molecular-weight (HMF) and low-molecular-weight (LMF) fractions. These fractions were used in XTT [2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide] antiviral assay which can quantitatively measure cytopathic effects of HIV-1 on CEM, human T lymphoblastoid cell line. The CEM cell line added with serial diluted HMF or LMF was cultured in the absence or presence of HIV-1. The results showed that the LMF of the aqueous extract strongly inhibited cytopathic effect of the target cell induced by HIV-1. When two-fold serially diluted LMF ranging from $40.97{\mu}g/ml$4 to 125.00 .mu.g/ml was added to the virus-free culture system, no toxicity on the target cells was detected in all the concentrations tested. However, when it was added to the HIV-infected culture system, the viabilities of the target cell reached a plateau recovering its viabilities to 71.7% and 82.5% in experiment-1 and -2 at 15.60 .mu.g/ml, respectively. The cell viabilities were then gradually decreased but maintained at more than 50% above 31.20 .mu.g/ml concentration. On the contrary, HMF did not prevent any HIV-induced cytopathic effect at any concentrations tested on this cell line. From these results, negligible toxicities were observed by both HMF and LMF of G. luciolum, and recovery of cell viability in HIV infected target cell was induced only by LMF of the carpophores.

• Restorative Dentistry and Endodontics
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• v.39 no.2
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• pp.137-142
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• 2014

This article presents the successful surgical management of a failed mineral trioxide aggregate (MTA) orthograde obturation of a tooth with a history of impact trauma and perforated internal root resorption. A symptomatic maxillary lateral incisor with a history of perforation due to internal root resorption and nonsurgical repair using MTA was referred. Unintentional overfill of the defect with MTA had occurred 4 yr before the initial visit. The excess MTA had since disappeared, and a radiolucent lesion adjacent to the perforation site was evident radiographically. Surgical endodontic retreatment was performed using calcium enriched mixture (CEM) cement as a repair material. Histological examination of the lesion revealed granulation tissue with chronic inflammation, and small fragments of MTA encapsulated within fibroconnective tissue. At the one and two year follow up exams, all signs and symptoms of disease had resolved and the tooth was functional. Complete radiographic healing of the lesion was observed two years after the initial visit. This case report illustrates how the selection of an appropriate approach to treatment of a perforation can affect the long term prognosis of a tooth. In addition, extrusion of MTA into a periradicular lesion should be avoided.

• Journal of the Korean Chemical Society
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• v.44 no.4
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• pp.343-349
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• 2000

Volatile Organic Compounds(VOCs) emitted form electronicSince toluene, xylene, cyclohexanone, and benzofuran will bring on the deleterious smell and the health risk, eventhough very small amount of these areexposed to human body, quantitative analysis was achieved by GC-MS system. As a result of these analyses, except PCB(CEM-1) of which is one of the electronic parts, the left of electronic parts represented, imme-diately form 30 minutes to 1 hour after heating, the trends that toluene, xylene, cyclohexanone and phenol were consecuticely emitted very high. and toluene, xylene, phenol, cyclohexanone, and benzofuran from most of the electronic parts were emitted very frequently within the measuring period. Finally, Trans of electronic parts showed the highest concentration of emission, and xylene(550~2482 ${\mu}g/m^2$) was the most noticeably emitting compound of VOCs.