• Bulletin of the Korean Chemical Society
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• 제24권9호
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• pp.1308-1312
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• 2003

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to observe folic acid and its derivatives such as tetrahydrofolate and 5-methyltetrahydrofolate in a vitamin tablet and in foods. Folic acid in a vitamin tablet was determined using angiotensin I as an internal reference. Tetrahydrofolic acid, 5-methyltetrahydrofolic acid, and an oxygenated folate were observed from a human blood sample using graphite plate. The results show that these mass spectrometric methods are useful for quickly obtaining a profile of folates.

• Elastomers and Composites
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• 제42권1호
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• pp.1-8
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• 2007

풀러렌 산화물 쪼개짐 반응은 $FeCl_3$를 첨가한 초음파 조건에서 4-nitroaniline, 3-nitroaniline, 4-isopropylaniline 등의 방향족 아민 화합물과 풀러렌 산화물을 반응시켜 일어났다. MALDI-TOF-MS와 UV-vis 스펙트라를 사용하여 풀러렌 산화물 쪼개짐 반응으로 생성된 화합물이 아민화 풀러렌 유도체임을 확인하였다.

• 폴리머
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• 제26권5호
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• pp.568-574
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• 2002

호스트 분자로서 환형 폴리옥시에틸렌을 사용한 inclusion 화합물을 이용하여 수용액상에서 피롤의 화학적 중합을 수행하였다. 이와 같은 합성 전략은 수용액상에서 화학적 산화방법에 의해 견고한 방향족 고분자의 사슬을 성장시킬 수 있는 가능성을 나타내며, 수용성 올리고 또는 폴리피롤을 손쉽게 얻을 수 있는 방법을 제시하고 있다. 본 연구에서는 부분적으로 고분자 주사슬에 환형 폴리옥시에틸렌을 함유한 수용성 폴리피롤을 얻었으며, NMR, IR, UV 및 MALDI-TOF MS 분석 등을 통하여 그 구조를 확인하였다.

• 대한임상검사과학회지
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• 제47권4호
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• pp.286-291
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• 2015

에쿠올은 인간의 건강에 유익한 효과를 나타낸다. 발효된 콩 식품들은 에쿠올을 함유하고 있으며, 많은 미생물들이 에쿠올 생산과정에 참여하는 것으로 밝혀졌다. 본 연구에서는 한국의 전통 발효 식품인 된장에 대해 조사하였다. 먼저 서로 다른 제조자로부터 수집 된 37개의 된장 샘플들을 대상으로 에쿠올의 농도를 측정하기 위해 LC-MS/MS를 시행하였다. 측정 결과 3개의 된장 샘플에서 에쿠올이 검출되었고, 507 ng/100 g의 농도가 가장 높게 나타났다. 에쿠올을 함유한 된장에서 15개의 미생물 종들이 16S rRNA gene sequence analysis와 2개의 MALDI-TOF MS분석법에 의해 분리, 동정되었으며 Bacillus spp, Paenibacillus spp, Tetragenococcus spp, Stapylococcus spp, and Clostridium species들이 가장 우세한 미생물들이었다. 이 연구결과로 한국의 전통 발효식품인 된장에서도 에쿠올이 검출되었음을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3119-3121
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• 2012

• Journal of Microbiology
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• 제42권3호
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• pp.200-204
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• 2004

Retron is a prokaryotic genetic element that produces multicopy single-stranded DNA covalently linked to RNA (msDNA) by a reverse transcriptase. It was found that cells producing a large amount of msDNA, rather than those that did not, showed a higher rate of mutation. In order to understand the molecular mechanism connecting msDNA production to the high mutation rate the protein patterns were compared by two dimensional gel electrophoresis. Ten proteins were found to be differentially expressed at levels more than three fold greater in cells with than without msDNA, nine of which were identified by MALDI TOF MS. Eight of the nine identified proteins were repressed in msDNA-producing cells and, surprisingly, most were proteins functioning in the dissimilation of various carbon sources. One protein was induced four fold greater in the msDNA producing cells and was identified as a 30S ribosomal protein S2 involved in the regulation of translation. The molecular mechanism underlying the elevated mutation in msDNA-producing cell still remains elusive.

• International Journal of Industrial Entomology and Biomaterials
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• 제16권2호
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• pp.37-48
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• 2008

The diapause and non diapause associated proteins of multivoltine silkworm eggs were analysed by two dimensional (2D) gel electrophoresis. The study was made at 0 hr, 24 hrs and 48 hrs after oviposition. A total of four protein spots in diapause eggs at 24 hrs of oviposition and two protein spots in non diapause eggs at 0 hrs of oviposition were observed. All the six protein spots were considered to have association with diapause and non diapause characters. The molecular weight (MW) and isoelectric point (PI) of these 6 protein spots were calculated. The protein spots 1 and 2 observed in 0 hr of non diapause eggs were found to have the MW of 67 and 75 KDa and PI of 8.6 and 8.4 respectively. Similarly the four protein spots observed in diapause egg at 24 hrs of oviposition exhibited MW viz., 15, 17,20 and 25 KDa and PI of 5.3, 5.8, 6.5 and 6.0 respectively. All these 6 identified protein spots were subjected to in-gel digestion and resulted tryptic peptides were analyzed by Matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI TOF-MS). Databases searched based on experimentally determined molecular weights of peptides for the determination of the identities of proteins. The identified proteins indicated homology of 34% to 95%. The results indicate that the proteins may playa role in development of diapause and non diapause eggs.

• Journal of Plant Biotechnology
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• 제39권4호
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• pp.261-272
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• 2012

Environmental factors greatly influence the growth, development, and even genetic characteristics of plants. The mechanisms by which sound influences plant growth, however, remain obscure. Previously, our group reported that several genes were differentially regulated by specific frequenciesof sound treatmentusing a sound-treated subtractive library. In this study, we used a proteomic approach to investigate plant responses to sound waves in Arabidopsis. The plants were exposed to 250-Hz or 500-Hz sound waves, and total proteins were extracted from leaves 8 h and 24 h after treatment. Proteins extracted from leaves were subjected to 2-DE analysis. Thirty-eight spots were found to be differentially regulated in response to sound waves and were identified using MALDI-TOF MS and MALDI-TOF/TOF MS. The functions of the identified proteins were classified into photosynthesis, stress and defense, nitrogen metabolism, and carbohydrate metabolism. To the best of our knowledge, this is the first report on the analysis of protein changes in response to sound waves in Arabidopsis leaves. These findings provide a better understanding of the molecular basis of responses to sound waves in Arabidopsis.

• Elastomers and Composites
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• 제40권3호
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• pp.174-180
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• 2005

공기 중 초음파 조건에서 풀러렌$[C_{70}]$과 금속 헥사카르보닐 착물 $M(CO)_6$ (M=Cr, Mo, W)을 반응시켜 풀러렌 산화물 $[C_{70}O_n](n=1{\sim}2)$을 합성하였다. 동일한 초음파 조건에서 풀러렌$[C_{70}]$과 여러 가지 금속 헥사카르보닐 착물 $M(CO)_6$ (M=Cr, Mo, W)의 반응성은 $Mo(CO)_6$ > $W(CO)_6$ > $Cr(CO)_6$ 순으로 증가함을 나타냈다. MALDI-TOF-MS, UV-visible 스펙트럼과 HPLC를 사용하여 분석한 결과 초음파화학 반응의 생성물은 $[C_{70}O_n](n=1{\sim}2)$ 임을 알 수 있었다.

• Elastomers and Composites
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• 제39권2호
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• pp.153-160
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• 2004

풀러렌($C_{70}$)을 3-picoline N-oxide, pyridine N-oxide hydrate, quinoline N-oxide, isoquinolne N-oxide의 여러가지 아민 N-옥시드를 사용하여 $25{\sim}43^{\circ}C$, 초음파 조건에서 반응시켜 풀러렌 산화물을 합성 하였다. 동일한 초음파 조건에서 여러가지 아민 N-옥시드에 대한 풀러렌 ($C_{70}$)의 반응성은 3-picoline N-oxide : pyridine N-oxide hydrate : quinoline N-oxide : isoquinoline N-oxide 처럼 동일하게 나타났다. MALDI -TOF MS, UV-vis 그리고 HPLC를 사용하여 생성된 풀러렌 산화물을 분석한 결과 [$C_{70}(O)n$] (n=1) 임을 알 수 있었다.