• 대한치과보철학회지
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• 제38권2호
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• pp.129-146
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• 2000

An increasing demand for esthetic restorations has led to the development of new ceramic systems. In-Ceram, a glass-infiltrated alumina ceramic has three to few times greater flexural strength than other ceramic glass material. Because of its high strength, In-Ceram has been suggested as inlay, crown, laminate veneer and core material for resin bonded fixed partial dentures. This clinical application requires a stable resin bond to In-Ceram core. The purpose of this study was to evaluate the shear bond strength between In-Ceram core and resin cements according to various surface treatments and storage conditions. The surface of each In-Ceram core sample was subjected to one of the following treatments and then bonded to Panavia 21 or Variolink II resin cement. ; (1) sandblasting with $110{\mu}m$ aluminum oxide powder, (2) sandblasting and silanization, (3) sandblasting and Siloc treatment, (4) sandblasting and Targis link application. Each of eight bonding groups was tested in shear bond strengths after the following storage times and thermocycling. ; A) 24 hours storage in distilled water at $37^{\circ}C$, B) 5 weeks storage in distilled water at $37^{\circ}C$ C) 5 weeks storage in distilled water at $37^{\circ}C$ and thermocycled 2,000 thormocycling for every 10 days(totally 10,000 thermocycting) in $5^{\circ}C-55^{\circ}C$ bath. The bond failure modes were observed with scanning electron microscope(SEM). The results were as fellows : 1 The shear bond strengths of sandblasting group were significantly lesser than the other groups after 24 hours water storage. No significant difference of bonding strengths was found between storage time conditions(24 hours and 5 weeks). The shear bond strengths showed a tendency to decrease in Variolink II bonding groups and to increase in Panavia 21 bonding groups. 3. After thermocycling, the shear bond strengths of all groups were significantly decreased(p<0.01) and Targis link group exhibited significantly greater strengths than the other groups(p<0.05). 4. Panavia 21 bonding groups exhibited significantly greater bonding strengths in sandblasting group(p<0.01) and silane group(p<0.05) than Variolink II bonding groups. 5. In observation of bond failure modes, Targis link group showed cohesive failure in resin part and silane group and Siloc group showed complex failure and sandblasting group showed adhesive failure between In-Ceram and resin.

• 한국가구학회지
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• 제19권2호
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• pp.137-140
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• 2008

This experiment states the ultra pure distilled water penetration depth through ray parenchyma cell in radial direction of Castanea crenata. Heartwood penetration depth was 1.16 times lower than the depth in softwood and that difference was found statistically significant at 75.2 second of penetration. Following go-stop-go cycle, water penetrated in the ray parenchyma cell. At the beginning this speed was high and then it was decreased slowly. Water penetration depth result was compared with alcohol penetration depth. It was found that water penetration in ray parenchyma was found lower than alcohol due to the low surface tension of water.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.43-47
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• 2000

In vitro cytotoxicity and antioxidative effects of water extracts prepared from Mustard Leaf Kimchi (MLK) during its fermentation period were investigated. The cytotoxicity against HepG2 (human hepatic cancer) by water extracts from the well fermented Mustard Leaf Kimchi was higher than others (fermented for 0 to 6 days at 18$^{\circ}C$), and IC50 of water extracts at the points of 6, 8, 10, and 14days during fermentation were 213.4, 99.2, 99.9, and 109.8${\mu}{\textrm}{m}$/ml, respectively. Antioxidative activity of water extracts from MLK during various fermentation periods was higher than that of blank distilled water. However, the antioxidative activity of well-fermented water extracts of MLK (fermented for 8-14 days) did not show any difference from that of others (fermented for 2-6 days). Thus, water extracts of well-fermented MLK (fermented during 8-14 days) significantly inhibited the growth of cancer cells in vitro, but little antioxidative activity was influenced by the various fermentation periods.

• Applied Microscopy
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• 제24권4호
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• pp.107-114
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• 1994

The Rotaviruses are members of the family Reoviridae and are the major cause of severe childhood gastroenteritis worldwide. Recently, electron microscopy has been used to detect non-group A rotaviruses to determine a relatively high resolution structure of the rotavirion. Mature, infectious virions(double-shelled particles) have a diameter of approximately 70nm, and have a capsid structure composed of two concentric protein layers. We have studied patient's stool specimen by negative staining technique complete removal of sucrose suspension. This negative staining technique that could be carried out in about 30 minutes and that could be used with crude stool specimen was an advantage of major significance. Removal of sucrose in the sample by has been completed washing with distilled of sucrose and by washing with distilled water. Ultrastructurally, typical feature of rotavirus has a double capsid construction with an inner capsid of 55nm and on outer 65-70nm diameter can be clearly demonstrated.

• 치위생과학회지
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• 제12권4호
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• pp.342-347
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• 2012

본 연구는 임시치관을 장착하고 있는 기간 동안에 커피의 노출을 피하기 어려운 점을 감안하고자 자가 중합형 임시치관용 레진의 시편을 제작하여 증류수와 3종의 커피에 담가 각각의 변색정도를 색상 측정 기구를 사용하여 색 안정을 비교하고자 하였다. 본 연구에서는 임시치관 제작 시 주로 사용되는 자가중합형 임시치관용 레진의 색 안정성을 살펴보고자 증류수와 3종류의 커피용액에 담가 1일, 7일, 14일, 21일, 28일 후 색변화를 분광광도계를 이용하여 CIE 표색계에 따라 명도지수 ${\Delta}L^*$, 적색채도 ${\Delta}a^*$, 황색채도 ${\Delta}b^*$, 색차 ${\Delta}E^*$를 측정하여 다음과 같은 결과를 얻었다. 1. 명도지수($L^*$) 변화는 침지시간이 증가할수록 증류수와 아메리카노, 카페라떼, 바닐라라떼의 명도가 유의하게 감소하였다(p<.001). 아메리카노에서의 명도가 가장 크게 감소하는 경향이 나타났으며 카페라떼, 바닐라라떼, 증류수 순이었다. 2. 적색채도($a^*$) 변화는 침지시간이 증가할수록 적색채도가 증가하는 경향을 보였으나 아메리카노, 카페라떼에서의 적색채도는 통계적으로 유의한 차이가 있었고 증류수와 바닐라라떼에서는 유의하지 않았다(p<.05). 3. 황색채도($b^*$) 변화는 침지시간이 증가할수록 황색채도가 증가하는 경향을 보였으나 카페라떼를 제외한 증류수, 아메리카노, 바닐라라떼에서의 황색채도는 통계적으로 유의한 차이가 없었다(p<.05). 4. 색차(${\Delta}E^*$) 변화는 침지시간이 증가할수록 아메리카노>카페라떼>바닐라라떼의 순서로 변색이 나타났으며 통계적으로 유의한 차이가 있었다(p<.05). 아메리카노에서는 침지 28일 이후에 색차가 3.3을 초과하여 수용도 역치 이상의 변색이 나타났으나 카페라떼와 바닐라라떼에서는 침지 28일 이후에도 1~2정도로 육안으로는 구분하기 어려운 변색이 나타났다. 증류수에서는 색차(${\Delta}E^*$) 값에 통계적으로 차이가 없었다(p>.05).

• 한국가구학회지
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• 제19권2호
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• pp.111-115
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• 2008

An experiment was conducted to know ultra-pure distilled water penetration depth through large vessel, small vessel, latewood fiber and earlywood fiber in longitudinal direction of Castanea crenata. In heartwood, latewood fiber transported water more than large and small vessel. While in sapwood, small vessel conduction depth was found the highest. Penetration depth of water after 15.0 seconds, no significant difference was observed among earlywood fiber, latewood fiber and earlywood vessel. Whilst in heartwood, no statistical difference was observed among earlywood fiber, latewood fiber and earlywood vessel. At the beginning, the speed of water penetration was high and then gradually decreased.

• 동력기계공학회지
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• 제9권1호
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• pp.64-69
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• 2005

In evaluation of electronic reliability on the PCB(Print Circuit Borad),electrochemical migration is one of main test objects. The phenomenon of electrochemical migration occurs in the environment of the hight humidity and the hight temperature under bias through a continuous aqueous electrolyte. In this paper, the generating mechanism of electrochemical migration is investigated by using water drop acceleration test under various waters. The waters used in the water drop test are city water, distilled water and ionic water. It found that the generated velocity of electrochemical migration depended on electrolyte quantity which included in the various waters.

• 한국식품영양학회지
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• 제16권4호
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• pp.347-352
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• 2003

단메밀과 콩 등으로부터 생리기능성 물질을 추출하여 건강식품을 개발하고자 먼저 물과 에탄올을 사용하여 extracts를 추출한 후 엔지오텐신 전환효소 (ACE) 저해활성과 항산화활성 및 SOD-유사활성 등을 측정하였다. 단메밀의 ACE저해 활성과 tyrosinase 저해 활성은 물 추출물에서 각각 53%와 58%로 에탄을 추출물보다 더 높았고 전자공여능은 에탄을 추출물에서 제일 높은 72%를 보였다. 검정종 1호와 태광콩의 ACE 저해 활성과 전자공여능은 물 추출물에서 높았으나 SOD-유사활성은 에탄을 추출물에서 가장 높았다. 단메밀 중의 ACE 저해물질과 tyrosinase 저해 물질들은 20배의 증류수로 35$^{\circ}C$에서 각각 24시간, 36시간 처리했을 때 가장 많이 추출되었고 전자공여능을 나타내는 항산화물질은 5$0^{\circ}C$에서 18시간 처리했을 때 가장 많이 추출되었다. 또한 검정콩 1호의 ACE 저해물질은 2$0^{\circ}C$, 24시간에서 가장 많이 추출되었으나 그 밖의 기능성 물질들은 2$0^{\circ}C$에서 18시간 추출하였을 때 가장 많이 추출되었다.

• Journal of Microbiology and Biotechnology
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• 제29권10호
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• pp.1495-1505
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• 2019

The Burkholderia cepacia complex (BCC) is capable of remaining viable in low-nutrient environments and harsh conditions, posing a contamination risk in non-sterile pharmaceutical products as well as a challenge for detection. To develop optimal recovery methods to detect BCC, three oligotrophic media were evaluated and compared with nutrient media for the recovery of BCC from autoclaved distilled water or antiseptic solutions. Serial dilutions ($10^{-1}$ to $10^{-12}CFU/ml$) of 20 BCC strains were inoculated into autoclaved distilled water and stored at $6^{\circ}C$, $23^{\circ}C$ and $42^{\circ}C$ for 42 days. Six suspensions of Burkholderia cenocepacia were used to inoculate aqueous solutions containing $5{\mu}g/ml$ and $50{\mu}g/ml$ chlorhexidine gluconate (CHX) and $10{\mu}g/ml$ benzalkonium chloride (BZK), and stored at $23^{\circ}C$ for a further 199 days. Nutrient media such as Tryptic Soy Agar (TSA) or Tryptic Soy Broth (TSB), oligotrophic media (1/10 strength TSA or TSB, Reasoner's $2^{nd}$ Agar [R2A] or Reasoner's $2^{nd}$ Broth [R2AB], and 1/3 strength R2A or R2AB) were compared by inoculating these media with BCC from autoclaved distilled water and from antiseptic samples. The recovery of BCC in water or antiseptics was higher in culture broth than on solid media. Oligotrophic medium showed a higher recovery efficiency than TSA or TSB for the detection of 20 BCC samples. Results from multiple comparisons allowed us to directly identify significant differences between TSA or TSB and oligotrophic media. An oligotrophic medium pre-enrichment resuscitation step is offered for the United States Pharmacopeia (USP) proposed compendial test method for BCC detection.

• 한국응용과학기술학회지
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• 제8권1호
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• pp.79-83
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• 1991

The extracts of Quercisemen(Quereus acutissima Carruthers seed) powder was obtained by the extraction with distilled water, water : acetonet(1:1, v/v), ethanol and ethyl ether, respectively. As a result this experiment, the antioxidative activity of each solvent extracts on linoleic acid were examined as follows: 1. Each fraction extracted by the acetone : water(1:1, v/v), water and ethanol respectively showed high antioxidative activity. 2. A fraction of the tannin extracted from the solvent, acetone, water(1:1, v/v) showed even more antioxidative activity than that of the ${\alpha}$-tocopherol or BHT. 3. Acceleration of peroxide reaction by $Fe^{++}$ and $Cu^{++}$ on the linoleic acid was strongly inhibited by adding the tannin, 4. Organic acid, such as malic acid, citiric acid and tartaric acid with the tannin were showed the synergistic effect fo the antioxidation reaction.