• 대한치과보철학회지
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• 제46권3호
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• pp.298-306
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• 2008

STATEMENT OF PROBLEM: Effect of surface treatment of ceramic under loading does not appear to have been investigated. PURPOSE: The aim of this study was to investigate the effect of surface treatment of esthetic ceramic, which is performed to increase the bonding strength, on the fracture stress under controlled cyclic loading condition. MATERIAL AND METHODS: Sixty 1.0 mm-thick specimens were made from Mark II Vitablocs (Vita Zahnfabrik, Germany) and divided into 3 groups: polished (control), sandblasted, and etched. Specimens of each group were bonded to a dentin analog material base including micro-channels to facilitate the flow of water to the bonding interface. Bonded ceramics were cyclically loaded with a flat-end piston in the water (500,000 cycles, 15Hz). Following completion of cyclic loading, specimens were examined for subsurface crack formation and subsequent stress was determined and loaded to next specimen by the staircase method according to the crack existence. RESULTS: There were significant differences of mean fatigue limit in the sandblasted (222.86 ${\pm}$ 23.42 N) and etched group (222.86 ${\pm}$ 14.16 N) when compared to polished group (251.43 ${\pm}$ 10.6 N) (P<.05; Wald-type pair-wise comparison and post hoc Bonferroni test). Of cracked specimens, surface treated group showed longer crack propagation after 24 hours. All failures originated from the radial cracking without cone crack. Fracture resistance of this study was very low and comparable to failure load in the oral cavity. CONCLUSION: Well controlled cyclic loading could induce clinically relevant cracks and fracture resistance of Mark II ceramic was relatively low applicable only to anterior restorations. Surface treatment of inner surface of feldspathic porcelain in the matsicatory area could influence lifetime of restorations.

• 생물정신의학
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• 제18권2호
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• pp.101-108
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• 2011

Objectives The aim of this study is to explore the association among DRD4 polymorphism, temperament and alcohol drinking behavior of Koreans in their early adulthood. Method Participants were 172 healthy Korean adults (mean age $28.1{\pm}0.8$). Their temperament was assessed with the Temperament and Character Inventory (TCI) and their alcohol drinking behavior were evaluated with a self-reported questionnaire including the CAGE and the Korean version of Alcohol Use Disorder Identification Test (AUDIT-K). DRD4 exon III 48 base pair variable number of tandem repeats (VNTR) was genotyped by PCR. Results No significant association was found between DRD4 polymorphism and TCI temperament dimension (novelty seeking, harm avoidance, reward dependence, and persistence) as well as alcohol drinking behavior scales. However, novelty seeking was significantly associated with alcohol drinking behavior. The higher level of novelty seeking was associated with the higher severity index of drinking (B = -0.225, p < 0.001) and problematic alcohol use on the CAGE and AUDIT-K [Odds Ratio (OR) = 1.111, 95% Confidence Interval (CI) 1.021-1.209, p = 0.015, OR = 1.087, 95% CI 1.009-1.170, p = 0.028]. Conclusion In our study, while there is no significant association of DRD4 polymorphism with temperament and alcohol drinking behavior, novelty seeking affects problematic alcohol use. Results suggest that novelty seeking may play an important role in problematic alcohol use in young Korean adults.

• Parasites, Hosts and Diseases
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• 제42권2호
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• pp.85-89
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• 2004

Cryptosporidium parvum oocysts were isolated from a child suffering from acute gastroenteritis and successfully passaged in a calf and mice (designated hereafter SNU-H1) in the Republic of Korea; its molecular genotype has been analyzed. The GAG microsatellite region was amplified by a polymerase chain reaction (PCR), with a 238 base pair product, which is commonly displayed in C. parvum. The isolate was shown to be a mixture of the genotypes 1 (anthroponotic) and 2 (zoonotic). To study its infectivity in animals, 2 calves and 3 strains of mice were infected with the SNU-H1; in these animals, the propagation of both genotypes was successful. In immunosup-pressed (ImSP) BALB/c and C57BU6 mice the number of oocysts decreased after day 10 post-infection (PI); but in ImSP ICR mice, they remained constant until day 27 PI. The results show that both the C. parvum genotypes 1 and 2 can be propagated in calves and ImSP mice.

• 대한화학회지
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• 제51권1호
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• pp.7-13
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• 2007

옥사졸 고리를 포함하는 lexitropsin에서, DNA minor groove의 구아닌-시토신 염기쌍의 구아닌과 수소결합을 형성하는데 중요 역할을 하는 옥사졸에 대해, 양성자화 될 때 가능한 두 가지 형태에 대해 DFT 계산을 통해 구조를 최적화시켰다. 최적화된 구조에 대해 B3LYP/6-31G* 수준에서 양성자 친화도를 계산하였다. 그 결과 옥사졸의 가능한 두 가지 형태 가운데 옥사졸의 질소 원자가 DNA minor groove 쪽으로 배향된 구조가 산소 원자가 minor groove 쪽으로 배향된 구조보다 양성자 친화도가 더 큼을 알 수 있었으며, 분자정전기 전위로 확인할 수 있었다. 아울러 양성자 친화도에 미치는 치환기 효과를 알아보기 위하여 여러 전자 주는 기와 전자 받는 기를 치환시켜 치환기 성질에 따른 양성자 친화도를 조사하였으며, 전자를 받는 기 보다 전자를 주는 기가 치환 되었을 때 양성자 친화도가 증가함을 알았다.

• Journal of Ginseng Research
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• 제42권1호
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• pp.21-26
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• 2018

Background: Furosine (${\varepsilon}$-N-2-furoylmethyl-L-lysine, FML) is an amino acid derivative, which is considered to be an important indicator of the extent of damage (deteriorating the quality of amino acid and proteins due to a blockage of lysine and a decrease in the digestibility of proteins) during the early stages of the Maillard reaction. In addition, FML has been proven to be harmful because it is closely related to a variety of diseases such as diabetes. The qualitative analysis of FML in fresh and processed ginsengs was confirmed using HPLC-MS. Methods: An ion-pair reversed-phase LC method was used for the quantitative analysis of FML in various ginseng samples. Results: The contents of FML in the ginseng samples were 3.35-42.28 g/kg protein. The lowest value was observed in the freshly collected ginseng samples, and the highest value was found in the black ginseng concentrate. Heat treatment and honey addition significantly increased the FML content from 3.35 g/kg protein to 42.28 g/kg protein. Conclusion: These results indicate that FML is a promising indicator to estimate the heat treatment degree and honey addition level during the manufacture of ginseng products. The FML content is also an important parameter to identity the quality of ginseng products. In addition, the generation and regulation of potentially harmful Maillard reaction products-FML in ginseng processing was also investigated, providing a solid theoretical foundation and valuable reference for safe ginseng processing.

• 대한수의학회지
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• 제38권3호
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• pp.606-613
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• 1998

Cadmium is one of the well-known environmental toxicants and induces cancer in rodents and human, but its carcinogenic mechanism has not been well demonstrated until now. Genotoxic effects of cadmium in Salmonella typhimurium TA98, TA100 and TA1535/pSK1002 or in WB-F344 rat liver epithelial cells were investigated to elucidate the tumor initiating effects of cadmium. TA98, TA100 and TA1535/pSK1002 tester strains were used to detect frameshift mutation, base-pair mutation and SOS repair response, respectively, in Salmonella mutation test. Reverse mutations from histidine to $histidin^+$ of Salmonella typhimurium TA98 and TA100 by $CdCl_2$ were not significantly different from control up to the maximum doses ($100{\mu}M$ and $200{\mu}M$ in TA98 and TA100, respectively) at which non-cytotoxicity was observed. DNA SOS repair responses(${\beta}$-galactosidase activity) generally did not show significant increases compared to control in both of the conditions with or without metabolic activation in Salmonella typhimurium TA1535/pSK1002 by $CdCl_2$. But the activities of ${\beta}$-galactosidase by $400{\mu}M$ of $CdCl_2$ in metabolic activation condition and by 130 and $400{\mu}M$ of $CdCl_2$ in non-metabolic activation condition were more decreased than those of control. DNA single strand breaks for 4hrs were observed only in WB-F344 rat liver epithelial cells treated with $200{\mu}M$ of $CdCl_2$. As a conclusion, $CdCl_2$ did not induce gene mutation in microbials but induce DNA single strand breaks in rat liver epithelial cells.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.182-182
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• 1999

The chemisorption effect of CO on the Ni/Cu(001) surface was investigated using LEED(Low Energy Electron Diffraction) and EELS(Electron Energy Loss Spectrscopy0 under the UHV conditions. after mounting the Cu(001) single crystal in the UHV chamber (base pressure 1$\times$10-10Torr), a clean surface was obtained after a few cycles of repeated Ar+ ion sputtering and annealing at about 40$0^{\circ}C$. The epitaxial thin Ni films were formed on the Cu(001) by evaporation from 99.999% Ni block. The pseudomorphic growth and the orderness of the thin Ni films were monitored by c(2$^{\circ}C$2) LEED pattern. CO adlayers on Ni epitaxial thin films were prepared by dosing pure CO has through a leak valve. After CO adsorpton at room temperature, two pairs of peaks were observed by EELS, whose relative intensities are changed as the film thickness is varied and time is elapsed. These two pair of peaks are likely related to different bonding sites (-top and bridge sites) of C-Ni as well as C-O vibration. Experimental results and qualitative interpretation of the spectra wille be discussed. The possibility of using EELS in combination with probe species (CO) to investigate the nature of thin film growth is mentioned. We will report the experimental result of O2 dosage on Ni film and interaction of CO and O2.

• 한국어류학회지
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• 제22권3호
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• pp.201-205
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• 2010

2008년 8월 경남 통영에서 강담돔과 돌돔의 자연교잡종 1개체가 발견되어 형태 및 유전적 특정을 강담돔 및 돌돔과 비교하였다. 형태적으로 본 총은 체측에 선명한 검은색 둥근 점을 많이 가지며 동시에 4개의 연한 가로줄을 가져 강담돔과 비슷하였다. 강담돔 및 돌돔의 계수 계측형질이 거의 일치하였으나, 체장에 대한 배지느러미길이 비에서 자연교잡종(26.7%)은 돌돔(17.2~23.6%)보다 강담돔(26.4%)에 더욱 가까웠다. 미토콘드리아 DNA 16S rRNA 510 bp를 이용한 분자분석에서 자연교잡종은 형태결과와는 달리 강담돔(d=0.020)보다 돌돔(d=0.000~0.010)에 더욱 가까웠다. 본 연구결과를 통해 경남 통영에서 발견된 자연교잡종은 암컷 돌돔과 수컷 강담돔 사이에서 태어난 것으로 추정된다.

• 한국전자파학회논문지
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• 제22권5호
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• pp.552-559
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• 2011

본 논문에서는 수직 적층형 다이폴 구조를 갖는 새로운 형태의 주파수 재구성 안테나를 제안하였다. 제안된 안테나는 셀룰러, PCS/WCDMA/Wibro/WiFi, WiMAX의 이동 통신 대역을 만족하도록 수직 적층형 다이폴 구조로 설계되었으며, 안테나의 동작은 각 대역의 다이폴과 전송 선로 간의 전위차를 이용하여 3쌍의 PIN 다이오드를 이용하여 스위칭되도록 하였다. 설계된 안테나는 각 이동 통신 서비스 대역에서 요구 동작 대역폭을 만족하였으며, 셀룰러 대역 6.3 dBi, PCS/WCDMA/ Wibro/WiFi 대역에서 5.4 dBi, WiMAX 대역에서 5.8 dBi의 이득 특성이 측정되었다. 제안된 안테나 구조는 각각의 다이폴 안테나 소자들이 수직 적층형으로 구성되기 때문에 지향 또는 반사 소자로서 상호 작용하는 역할을 하며, 안테나의 소형화가 가능하고, 고이득 특성을 구현할 수 있다는 장점을 갖기 때문에, 향후 재구성 소형 기지국 및 중계기 안테나 설계에 유용하게 사용할 수 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권11호
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• pp.1491-1495
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• 2004

Small Tail Han Sheep has significant characteristics of high prolificacy and non-seasonal ovulatory activity and is an excellent local sheep breed in P. R. China. Recently a novel member of the transforming growth factor $\beta$ (TGF$\beta$) superfamily termed bone morphogenetic protein 15 (BMP15) was shown to be specifically expressed in oocytes and to be essential for female fertility. Therefore, BMP15 is a candidate gene for reproductive performance of Small Tail Han Sheep. The whole genomic nucleotide sequence of BMP15 gene in Small Tail Han Sheep was searched for polymorphisms by PCR-SSCP and direct sequencing, and only one polymorphism was found. The polymorphism was a result of a 3 base pair deletion, which eliminated a single Leu codon (CTT). The allelic frequencies for A (without deletion) and B (with a codon deletion) are 0.73 and 0.27 respectively. The effects of BMP15 genotype on litter size were evaluated using the least squares model. This indicated that there was a significant association between litter size of Small Tail Han Sheep and a deletion in BMP15 gene (p=0.02<0.05). Small Tail Han Sheep ewes with AA and AB genotype produce on average 0.5 and 0.3 more lambs per litter than those ewes with BB genotype.