• Elastomers and Composites
• /
• 제38권2호
• /
• pp.147-156
• /
• 2003

풀러렌[$C_{60},\;C_{70}$]을 benzoylperoxide, trichloroisocyanuric acid, methyltrioxorhenium(VII), iodosobenzene 그리고 phosphorous pentoxide 등의 산화제를 사용하여 상온, 초음파 조건에서 풀러렌 산화물을 제조하였다. MALDI-TOF MS, UV-VIS 그리고 HPLC를 사용하여 분석한 결과 생성된 풀러렌 산화물은 [$C_{60}(O)_n$], ($n=1{\sim}3$ 또는 n=1)과 [$C_{70}(O)_n$], ($n=1{\sim}2$ 또는 n=1)임을 알 수 있었다. 한편, 동일한 실험 조건에서 $C_{60}$ 반응속도는 $C_{70}$ 보다 높았다.

• International Journal of Oral Biology
• /
• 제43권3호
• /
• pp.123-127
• /
• 2018

Polyphenon 60 refers to the mixture of catechins present in green tea. The aim of this study was to investigate the antimicrobial activities of polyphenon 60 against 4 strains of Streptococcus mutans and 2 strains of Streptococcus sorbrinus, which are the major causative bacteria of dental caries. The minimum bactericidal concentration (MBC) values of polyphenon 60 for S. mutans and S. sobrinus were determined and the effect of biofilm formation inhibition of that was evaluated. The MBC value of polyphenon 60 against the bacterial strains was 2.5 mg/ml except for one particular strain, S. mutans KCOM 1128 for which the value was 1.25 mg/ml. The results of biofilm formation inhibition assay revealed that polyphenon 60 inhibited biofilm formation more than 90% at a concentration of 2.5 mg/ml. It was apparent that polyphenon exhibited biofilm formation inhibition activity along with bactericidal effect against S. mutans and S. sobrinus. Therefore, it is proposed that polyphenon 60 as one of the components of bactericidal agents could be useful in developing oral hygiene products, toothpaste or gargling solution.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
• /
• pp.43-46
• /
• 2004

CuPc와 $C_{60}$을 이용하여 ITO/CuPc/Al의 CuPc 단층구조와 $ITO/CuPc/C_{60}/Al$의 이종접합 구조에서의 광기전 특성을 연구하였다. CuPc 단층구조에서는 CuPc층의 두께를 10nm에서 50nm로 가변하여 전압-전류 특성을 측정한 결과 40nm 부근에서 최적화된 전기적인 특성이 나타났으며, $CUPC/C_{60}$의 이종접합 구조에서는 CuPc와 $C_{60}$의 두께 비율을 1 : 1 (20nm : 20nm), 1 : 2 (20nm : 40nm), 1 : 3 (20nm : 60nm)으로 가변하여 측정한 결과, 1 : 2의 두께비에서 최적화된 특성을 얻었다. 광원은 500W Xe lamp(ORIEL 66021)를 이용하였으며, 광원의 세기는 보정된 radiometer/photometer (International Inc. IL14004)와 Si-photodiode로 측정하였다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2009년도 제38회 동계학술대회 초록집
• /
• pp.82-82
• /
• 2010

유기 쌍안정성 소자는 비휘발성 기억 소자 중에서 구조가 간단하고 제작비용이 저렴하며 유연성을 가지기 때문에 많은 연구가 진행되고 있다. 현재 유기물/무기물 나노복합소재를 사용하여 소자 성능 향상이 기억소자의 성능 향상을 위하여 여러 가지 유기물/무기물 나노복합소재를 사용하여 제작한 유기 쌍안정성 소자가 유연성을 가진 비휘발성 기억소자로 대두되고 있다. 본 연구에서는 ZnO 나노입자를 포함한 PMMA 복합층을 사용하여 제작한 유기 쌍안정성 기억소자를 제작하여 메모리 특성을 조사하였다. 이와 더불어 활성층에 효과적인 전하주입을 위하여 전극과 PMMA/ZnO 층 사이에 $C_{60}$ 층을 삽입한 구조를 가진 메모리 소자의 성능 향상에 대하여 연구하였다. Indium tin oxide 가 증착된 유리 기판위에 $C_{60}$ 층을 스핀코팅 방법으로 적층하였다. 1 wt% ZnO 나노입자와 1 wt% PMMA를 혼합하여 스핀코팅 방법으로 $C_{60}$ 층 위에 박막을 형성하였다. 그리고, 전극으로 Al을 열증착으로 형성하였다. $C_{60}$ 층이 있는 유기 쌍안정성 기억 소자와 $C_{60}$ 층이 없는 두 가지의 소자에 대하여 전류-전압 (I-V) 특성을 측정하여 각각의 소자에서의 전류 히스테리시스 현상이 발생하는 원인을 규명하였다. I-V 특성 결과와 전자적 구조를 사용하여 유기 쌍안정성 소자에서의 쓰기, 지우기 및 읽기 동작에 대한 과정을 설명하였다. 두 소자의 I-V 특성을 비교하므로 $C_{60}$ 층을 사용하여 유기 쌍안정성 소자의 성능이 향상됨을 알 수 있었다. 또한 $C_{60}$ 층을 사용하여 제작된 유기 쌍안정성 소자의 성능이 향상된 원인을 규명하였다.

• Toxicological Research
• /
• 제17권2호
• /
• pp.131-137
• /
• 2001

Baicalein, a major flavonoid of extract from Scutellaria baicalensis Georgi, has been shown to exhibit antioxidant and anti proliferative effects. In the present study, we investigate the effects of baicalein on viability and induction of apoptosis in human promyelocytic leukemia HL-60 cells. Baicalein was found to induce apoptosis of HL-60 cells in a concentration-dependent and time-dependent manner. When HL-60 cells were exposed to 100 $\mu\textrm{M}$ baicalein for 6h, the viability was decreased remarkably to 27% of control, whereas DNA fragmentation was significantly increased to 64%. Nucleosomal fragmentation of baicalein treated HL-60 cells, a hallmark of apoptosis, was further identified by agarose gel electrophoresis (DNA ladder). Flow cytometric analysis showed that apoptotic cells were increased to 66.6% after treatment with 100 $\mu\textrm{M}$ baicalein for 6 h. Baicalein-induced apoptosis of HL-60 cells was reduced by 1h pretreatment with inhibitor of caspases, z-Asp-$CH_2$-DCB. At 3 and 10 $\mu\textrm{M}$ of z-Asp-$CH_2$-DCB, DNA fragmentation of HL-60 cells induced by baicalein (50 $\mu\textrm{M}$) was 36.8 and 17.1 %, respectively, whereas, that of HL-60 cells treated by baicalein (50 $\mu\textrm{M}$) without pretreatment with inhibitor of caspases was 62.7%. These data suggest that baicalein induces apoptosis in human leukemia HL-60 cells, and that caspase enzymes might be involved in baicalein-induced apoptosis.

• Journal of Microbiology and Biotechnology
• /
• 제19권10호
• /
• pp.1206-1212
• /
• 2009

Growth rates, photosystem II photosynthesis, and the levels of chlorophyll $\alpha$ and secondary metabolites of Chlorella ovalis were estimated to determine if they were enhanced by the addition of swine urine (BM) or cow compost water (EP) that had been fermented by soil bacteria to deep seawater (DSW) in an attempt to develop media that enabled batch mass culture at lower costs. Growth of C. ovalis in f/2, f/2-EDTA+BM60%, DSW+BM30%, and DSW+EP60% was enhanced and maintained in the log phase of growth for 16 days. The cell densities of C. ovalis in DSW+EP60% ($4.1{\times}10^6$ Cells/ml) were higher than those of f/2 ($2.9{\times}10^6$ Cells/ml), f/2-E+BM60% ($3.7{\times}10^6$ Cells/ml), and DSW+BM30% ($2.7{\times}10^6$ Cells/ml). The growth rate was also more favorable for C. ovalis cultured in DSW+EP60% ($0.15\;day^{-1}$) than that of C. ovalis cultured in the control medium (f/2) ($0.12\;day^{-1}$). Furthermore, the chlorophyll a concentration of C. ovalis cultured in DSW+EP60% (4.56 mg/l) was more than 2-fold greater than that of C. ovalis cultured in f/2 (2.35 mg/l). Moreover, the maximal quantum yields of photo system II at 470 nm (Fv/Fm) were significantly higher in organisms cultured at f/2-E+BM60% (0.53) and DSW+EP60% (0.52) than in the other treatment groups. Finally, Fourier transformation infrared (FT-IR) spectroscopy revealed that C. ovalis grown in DSW+EP60% had more typical peaks and various biochemical pool shifts than those grown in other types of media. Taken together, the results of this study indicate that the use of DSW+EP60% to culture C. ovalis can reduce maintenance expenses and promote higher yields.

• 대한화장품학회지
• /
• 제33권1호
• /
• pp.7-10
• /
• 2007

수용성 폴리머와 계면활성제의 상호작용을 레올로지와 표면 장력을 측정하여 연구하였다. 본 연구에 사용된 폴리머는 acrylates/$C_{10-30}$ alkyl acrylate crosspolymer (AC), ammonium acryloyldimethyltaurate/VP copolymer (AV)이다. 계면활성제는 PEG-40 hydrogenated castor oil (HC), polysorbate 60 (P60)이다. HC와 P60은 AC 폴리머 주위에서 마이셀을 형성하여 점도를 증가하였다. 그러나, HC는 P60보다 보다 높은 농도 범위에서 점도 증가 거동을 보였다. 같은 농도 범위에서 계면활성제들의 표면장력을 비교해보면, 표면장력이 AC/HC의 농도 증가에 따라 증가한 반면, AC/P60의 농도증가에 대해서는 거의 증가하지 않았다. 이런 결과는 AC/HC 사이의 마이셀이 강하게 조직화된 구조를 형성하기 때문으로 추정된다.

• 한국의류학회지
• /
• 제28권6호
• /
• pp.746-757
• /
• 2004

This study was intended to analyze clothing preference images according to the age groups (30's, 40's, 50's and 60's) and to clarify the differences between present clothing preference images and that of the future after 60. The data was collected through a questionnaire and a total of 482 questionnaires on the age groups ranging from 30s through 60s were used in the analysis. As for the present clothing preference images in accordance with age groups, the younger age groups in the range of 30's and 40's presented higher scores in most of these images. But the older age groups in the 50's and 60's had lower scores in most of these images. On the contrary, the older age groups had higher scores than the younger age groups with respect to similar, mature, magnificent, innocent, plump and virtuous images. As for the future clothing preference images after 60 in the elegant, luxurious, graceful, intellectual, chic, urbane, slimy and sociable images, the age groups in the 30's and 40's presented higher scores than the age groups in the 50's and 60's did. However, with respect to the youth-oriented images such as fashionable, innocent, remarkable, cute and vigorous images, the age group in the 60's had a higher score than the age group in the 30's, 40's and 50's did. There were differences between the present clothing preference images and future clothing preference images after 60. The 30's and 40's presented distinctively different clothing preference images in the present and future after 60. Thus, distinct images were pursued in the older age group. The 50s showed closest images to that of the older age group, presenting more conservative inclination in clothing preferences.

• 한국식물학회:학술대회논문집
• /
• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
• /
• pp.57-62
• /
• 1999

Light-regulated translation of chloroplast mRNAs requires nuclear-encoded trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. A set of four proteins (60, 55, 47, and 38 kDa) that bind to the 5'-UTR of the psbA mRNA had been identified in C. reinhardtii. 47 kDa protein (RB47) was found to encode a chloroplast poly (A)-binding protein (cPABP) that specifically binds to the 5'-UTR of the psbA mRNA, and essential for translation of this mRNA, cDNA encoding 60 kDa protein (RB60) was isolated, and the amino acid sequence of the encoded protein was highly homologous to plants and mammalian protein disulfide isomerases (PDI), normally found in the endoplasmic reticulum (ER). Immunoblot analysis of C. reinhardtii proteins showed that anti-PDI recognized a distinct protein of 56 kDa in whole cell extract, whereas anti-rRB60 detected a 60 kDa protein. The ER-PDI was not retained on heparin-agarose resin whereas RB60 was retained. In vitro translation products of the RB60 cDNA can be transported into C. reinhardtii chloroplast in vitro. Immunoblot analysis of isolated pea chloroplasts indicated that higher plant also possess a RB60 homolog. In vitro RNA-binding studies showed that RB60 modulates the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP using redox potential or ADP-dependent phosphorylation. Site-directed mutagenesis of -CGHC- catalytic site in thioredoxin-like domain of RB60 is an unique PDI located in the chloroplast of C. reinhardtii, and suggest that the chloroplast PDI may have evolved to utilize the redox-regulated thioredoxin like domain as a mechanism for regulating the light-activated translation of the psbA mRNA.

• 한국식물학회:학술대회논문집
• /
• 한국식물학회 1985년도 워크샵 및 심포지엄 북한산국립공원의 식생
• /
• pp.7-18
• /
• 1985

Light-regulated translation of chloroplast mRNAs requires nuclear-encoded trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. A set of four proteins (60, 55, 47, and 38 kDa) that bind to the 5'-UTR of the psbA mRNA had been identified in C. reinhardtii. 47 kDa protein (RB47) was found to encode a chloroplast poly (A)-binding protein (cPABP) that specifically binds to the 5'-UTR of the psbA mRNA, and essential for translation of this mRNA, cDNA encoding 60 kDa protein (RB60) was isolated, and the amino acid sequence of the encoded protein was highly homologous to plants and mammalian protein disulfide isomerases (PDI), normally found in the endoplasmic reticulum (ER). Immunoblot analysis of C. reinhardtii proteins showed that anti-PDI recognized a distinct protein of 56 kDa in whole cell extract, whereas anti-rRB60 detected a 60 kDa protein. The ER-PDI was not retained on heparin-agarose resin whereas RB60 was retained. In vitro translation products of the RB60 cDNA can be transported into C. reinhardtii chloroplast in vitro. Immunoblot analysis of isolated pea chloroplasts indicated that higher plant also possess a RB60 homolog. In vitro RNA-binding studies showed that RB60 modulates the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP using redox potential or ADP-dependent phosphorylation. Site-directed mutagenesis of -CGHC- catalytic site in thioredoxin-like domain of RB60 is an unique PDI located in the chloroplast of C. reinhardtii, and suggest that the chloroplast PDI may have evolved to utilize the redox-regulated thioredoxin like domain as a mechanism for regulating the light-activated translation of the psbA mRNA.