• 한국식품영양학회지
• /
• 제17권3호
• /
• pp.254-259
• /
• 2004

Primer 20가지로 Listeria spp.에 대해 screening을 하여 병원균인 L. monocytogenes를 구별하게 하는 RAPD-PCR의 band pattern을 나타내는 10-mer random primer가 OPG-13이 라는 것을 알았다. OPG-13은 GC%가 70%이므로 계산상으로는 annealing 온도가 34$^{\circ}C$이다. 32～36$^{\circ}C$까지 다섯 가지의 온도로 annealing한 결과 L. monocytogenes만이 갖는 특정한 크기의 band가 역시 34$^{\circ}C$에서 형성됨을 알아냈고, 34$^{\circ}C$를 annealing 온도로 정하였다. Line 1부터 4까지 1. monocytogenes ATCC15313, 19111, 19112, 19113은 2개의 700 bp와 1500 bp band를 형성하였고 그 밖의 Listeria spp.들 Line 6부터 11까지 L. ivanovii ATCC 19119, L. grayi ATCC19120, L. murrayi ATCC25401, L. innocua ATCC33090, L. welshimeri ATCC35897, L. seeligeri ATCC35967은 약 2,000 ～ 2,300 bp크기 한 개의 band를 보여 병원성 균과 비병원성 균이 매우 확실하게 구분되는 band pattern이 나타나는 이러한 결과로 10-mer random primer인 OPG-13을 이용한 RAPD-PCR 방법이 병윈균인 L. monocytogenes를 검색하는데 이용될 수 있음을 확인할 수 있었다.

• 대한치과보철학회지
• /
• 제43권5호
• /
• pp.611-621
• /
• 2005

State of problem: Zirconia all-ceramic restoration fabricated with CAM system is on an increasing trend in dentistry. However, evaluation of the marginal and internal fits of zirconia bridge seldomly have been reported. Purpose: This study was to evaluate the at of margin and internal surface in posterior 3-unit zirconia bridge framework fabricated with CAM system(DeguDent, Germany). Material and Method: Preparations of secondary premolar and secondary molar on artificial resin model were performed for fabrication of 3-unit posterior bridge framework. Fits of 5 zirconia bridge framework were compared with 5 precious ceramo-metal alloy framework(V-GnathosPlus, Metalor, Switzerland), and prepared margins were designed to chamfer and shoulder finishing line. Each framework was cemented to epoxy resin model with reinforced glass ionomer(FujiCEM, GC Co., Japan), embedded in acrylic resin and sectioned in two planes, mesio-distal and buccolingual. Samples were divided into six pieces by sectioning and had two pieces of each surface(i.e mesial, distal, buccal and lingual surface) per abutment, so there were eight measuring points in each abutment. External gap was measured at the margin and internal gaps were measured at the margin, axial and occlusal surface. Gaps were observed under the measuring microscope(Compact measuring microscope STM5; Olympus, Japan) at a magnification of $\times100$. T-test were used to determine the statistic significance of the different gaps between zirconia and metal framework. Results and Conclusion: 1. External and internal marginal gaps of zirconia and metal framework were in clinically acceptable range. External marginal gaps were not different significantly between zirconia$(81.9{\mu}m)$ and metal $(81.3{\mu}m)$ framework and internal marginal gaps of zirconia $(44.6{\mu}m)$ were smaller than those of metal framework $(58.6{\mu}m)$. 2. Internal axial gaps of zirconia framework$(96.7{\mu}m)$ were larger than those of metal frame-work$(78.1{\mu}m)$ significantly and adversely, internal occlusal gaps of zirconia frame-work$(89.4{\mu}m)$ were smaller than those of metal framework $(104.9{\mu}m)$ significantly. 3. There were no significant differences in external and internal marginal gaps between chamfer and shoulder finish line when zirconia frameworks were fabricated.

• International Journal of Ocean System Engineering
• /
• 제2권4호
• /
• pp.239-243
• /
• 2012

The cylinder liner of a low speed engine is one of the most important parts of the marine diesel engines used in merchant ships. However, a sufficient degree of precision in the manufacturing method for these cylinder liners has never existed. Conventional honing stones have always been used for machining large marine cylinder liners. Therefore, it is necessary to develop a honing process that optimizes the honing characteristics. In this study, a CBN honing stone was manufactured to improve the honing performance for a cylinder liner and shorten the processing time, and machining experiments on a practical cylinder liner were carried out. Then, a comparison was made between the CBN honing and honing with a conventional GC stone using parameters such as the honing time, machining quantity, and honing cost. As a result, for a #60 CBN stone, the machining amount was significantly improved compared to the conventional one by about $1.1{\mu}m$/min, and in respect to the machining cost, a reduction of about 57% was achieved. However, an improvement in the process with a #800 CBN stone could not be expected because it did not show a significant difference compared to the case of the existing stone. From the above results, if the liner were honed using a CBN honing stone, the rough machining and intermediate processing during an early stage of the honing process were excellent compared to the conventional one. However, we could not find a significant difference in the case of finish honing.

• 한국연초학회지
• /
• 제30권2호
• /
• pp.117-124
• /
• 2008

A solid phase microextraction (SPME) method in combination with gas chromatography/mass spectrometric techniques was used for the extraction and quantification of 12 selected agrochemical residues in tobacco. The parameters such as the type of SPME fiber, adsorption/desorption time and the extraction temperature affecting the precision and accuracy of the SPME method were investigated and optimized. Among three types of fibers investigated, polyacrylate (PA), polydimethylsiloxane (PDMS) and polydimethylsiloxane-divinylbenzene (PDMS-DVB), PDMS fiber was selected for the extractions of the agrochemicals. The SPME device was automated and on-line coupled to a gas chromatograph with a mass spectrometer. Mass spectrometry (MS) was used and two different instruments, a quadrupole MS and triple quadrupole MS-MS mode, were compared. The performances of the two GC-MS instruments were comparable in terms of linearity (in the range of 0.01$\sim$0.5 $\mu$g/mL) and sensitivity (limits of detection were in the low ng/mL range). The triple quadrupole MS-MS instrument gave better precision than that of quadrupole MS system, but generally the relative standard deviations for replicates were acceptable for both instruments (< 15%). The LODs was fully satisfied the requirements of the CORESTA GRL. Recoveries of 12 selected agrochemicals in tobacco yielded more than 80% and reproducibility was found to be better than 10% RSD so that SPME procedure could be applied to the quantitative analysis of agrochemical residues in tobacco.

• 생명과학회지
• /
• 제24권12호
• /
• pp.1316-1324
• /
• 2014

신령버섯균사체(Agaricus blazei mycelia: ABM)를 대두박이 함유된 액체배지에 배양하고, 이것을 자가분해($53^{\circ}C$, pH 5.5, 120 rpm, 3 hr)하여 항암성이 강한 isoflavone-conjugated glycoprotein (Gluvone 이라 명명)을 분리하였다. Gluvone은 지금까지 알려진 당단백질과는 달리 분자량이 작고(9,400 Da), isoflavone이 결합되어 있다는 점이 다르다, Gluvone은 60% 탄수화물(glucose, fructose, ribose), 31% 단백질 및 2% isoflavone (daidzein, genistein)으로 구성되어 있었다. 이 Gluvone은 S-180 복수암세포, MCF-7 인체유선암세포에 대한 독성이 강하였고, S-180 세포로 유발한 mouse 복수암을 강하게 억제하였다.

• 분석과학
• /
• 제19권3호
• /
• pp.255-262
• /
• 2006

본 연구에서는 VOC가 옷감이나 물질소재와 접촉하여 흡착손실하는 경향을 평가하고자 하였다. 이를 위하여 필터홀더에 필터의 형식으로 비교대상 소재를 장착하고 이들에 VOC 가스를 흘려주는 방식으로 화합물의 흡착손실반응을 평가할 수 있는 기법의 적용 가능성을 다각도로 평가하였다. 테플론 소재의 필터는 양호한 안정성이나 재현성을 보여 주었다. 이러한 시스템에 각각의 소재(글래스 파이버, 면, 나일론)를 장착한 상태로 벤젠, 톨루엔, 자일렌이 혼합된 가스를 흘려 주면서 각각의 검량선을 작성하였다. 본 연구의 결과에 의하면, 각각의 소재 및 VOC 성분별로 뚜렷한 흡착특성을 확인할 수 있었다. 소재들 중에서는 글래스 파이버 < 면 < 나일론의 순서로 그리고 성분별로는 벤젠 < 톨루엔 <자일렌의 순서로 흡착손실이 증가하는 양상이 뚜렷하게 나타났다. 그 결과, 재질이나 화학물질의 특성과 같은 변수가 동시에 흡착손실의 경향성을 결정짓는다는 결론에 도달하였다.

• Journal of Microbiology and Biotechnology
• /
• 제21권9호
• /
• pp.893-902
• /
• 2011

Endophytic fungi are little known for their role in gibberellins (GAs) synthesis and abiotic stress resistance in crop plants. We isolated 10 endophytes from the roots of field-grown soybean and screened their culture filtrates (CF) on the GAs biosynthesis mutant rice line - Waito-C. CF bioassay showed that endophyte GMH-1B significantly promoted the growth of Waito-C compared with controls. GMH-1B was identified as Penicillium minioluteum LHL09 on the basis of ITS regions rDNA sequence homology and phylogenetic analyses. GC/MS-SIM analysis of CF of P. minioluteum revealed the presence of bioactive $GA_4$ and $GA_7$. In endophyte-soybean plant interaction, P. minioluteum association significantly promoted growth characteristics (shoot length, shoot fresh and dry biomasses, chlorophyll content, and leaf area) and nitrogen assimilation, with and without sodium chloride (NaCl)-induced salinity (70 and 140 mM) stress, as compared with control. Field-emission scanning electron microcopy showed active colonization of endophyte with host plants before and after stress treatments. In response to salinity stress, low endogenous abscisic acid and high salicylic acid accumulation in endophyte-associated plants elucidated the stress mitigation by P. minioluteum. The endophytic fungal symbiosis of P. minioluteum also increased the daidzein and genistein contents in the soybean as compared with control plants, under salt stress. Thus, P. minioluteum ameliorated the adverse effects of abiotic salinity stress and rescued soybean plant growth by influencing biosynthesis of the plant's hormones and flavonoids.

• 보존과학회지
• /
• 제37권5호
• /
• pp.525-535
• /
• 2021

본 연구는 동궁비 원삼의 직금단과 자수에 사용된 금사를 대상으로 과학적 분석을 통해 재료적 특성을 파악하였다. 동궁비 원삼의 금사 배지는 비목질계 섬유소가 관찰되어 닥나무 섬유의 한지를 사용한 것으로 추정된다. XRF 분석을 통해 동궁비 원삼의 통수스란에는 순금의 편금사, 색동과 한삼에는 편은사로 제직한 직금단임을 알 수 있었다. 특히 편은사에서는 황이 높게 검출되는데 이것은 은을 사용하여 금빛을 내기 위한 훈증의 유황 성분의 영향과 보존환경에 의한 황화은이 형성된 것으로 보인다. 또한 용보의 문양은 연금사와 연은사로 표현하였으며, 용보의 테두리는 순금의 연금사로 장식하였다. 특히 본 연구에서는 금사의 금속면과 배지 사이의 접착제와 혼합물에 대해 GC/MS, XRF, Raman 분석을 실시하였다. 그 결과 단백질계 화합물인 아교와 같은 접착제를 사용하고, 혼합물로는 편금사의 경우 활석을 섞고, 편은사에는 석간주를 혼합하여 사용하였음을 확인할 수 있었다.

• 보존과학회지
• /
• 제38권2호
• /
• pp.124-132
• /
• 2022

본 연구는 국가민속문화재 일월수 다라니 주머니 매듭과 테두리 장식에 사용된 '금속 장식지'를 대상으로 과학적 분석을 통해 재료적 특성을 파악하였다. 금속 장식지는 SEM-EDS 분석을 통해 은(Ag) 및 황(S)이 확인되어 은제 금속박을 배지에 부착하여 제작한 것으로 추정할 수 있다. 황(S)은 농도와 접촉시간에 따라 은(Ag)을 황색부터 흑색까지 변색시킬 수 있다. 현재는 황색을 확인할 수 없으나, 은(Ag)으로 가금사를 만든 사례가 있어 본래 색을 추정하기 위해서는 추가 연구가 필요하다. 배지는 배면까지 적갈색이다. 함께 검출된 알루미늄(Al)과 규소(Si), 철(Fe)은 전통 편금사(片金絲)의 붉은색 접착제로 추정되는 주토(朱土)의 주성분으로, 금속 장식지의 접착제 관련 성분으로 추측된다. GC/MS 분석 결과에서 접착제 성분은 아교(阿膠)로 확인할 수 있었다.

• Restorative Dentistry and Endodontics
• /
• 제23권1호
• /
• pp.433-442
• /
• 1998

The purpose of this study was to observe the changes of acidity of resin cement(Time Line), glass ionomer cement(GC Fugi Lining LC), zinc phosphate cement(Fleck's zinc cement). zinc oxide eugenol cement(Sultan,Chemists.) in vivo and in vitro. Class I cavities with 3mm depth were prepared on the occlusal surfaces of 20 recently extracted human Mn. molar teeth and 20 human Mn. 3rd molar teeth in oral cavity. The prepared cavities were divided into 4 groups of each 5 teeth using the above 4 cavity liners. Each cement was mixed in accordance with manufacturer's direction at the room temperature of $23^{\circ}{\pm}5^{\circ}C$ and filled into the cavity in a width of 1 mm. The microelectrode of pH meter was inserted into the prepared cavity which was filled with mixed cement, and the acidity of cement was measured for 3 days from the beginning of cement mix in vitro and in vivo. The measured acidity was then statistically analyzed by ANOVA. The results were as follows. 1. In vitro, the pH of zinc oxide eugenol cement was statistically lower than that of the three other groups at 2min, 4min, 6min, 8min, 10min, 12min, 18min, 20min. (p<0.05). 2. The pH of zinc oxide eugenol cement in vivo was statistically higher than that in vitro at 16min,16min, 20min(p<0.05). 3. The pH of zinc phosphate cement in vivo was statistically higher than that in vitro at 4min, 20min(p<0.05). 4. In vitro and in vivo, there was no significant difference in the pH between the resin cement and the glass ionomer cement(p>0.05). 5. The initial acidity was not high, but almost neutral in all kinds of the cements.