• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.15-21
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• 2004

The immunomodulating activities and chemical characteristics of a water-soluble exopolymer from submerged mycelial culture of Phellinus pini were studied. Anticomplementary activity of this polymer was found to be $73.2\%$, and its activation system occurred through both classical and alternative pathways, where the classical pathway was detected to be the major one by crossed immunoelectrophoresis. Nitric oxide (NO) release ability and acid phosphatase activity of macrophage were increased by 1.6-fold ($100{\mu}g/ml$) and 3.4-fold ($500{\mu}g/ml$), respectively, and splenocyte proliferation in mixed lymphocyte reaction (MLR) was also increased by 2.6-fold ($200{\mu}g/ml$), compared to the control. The molecular weight of this polymer, determined by HPLC, was under 5 kDa. Total sugar and protein contents were 89.7 and 10.3%, respectively. Both sugar and amino acid compositions of the exopolymer were also analyzed.

• Journal of Photoscience
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• v.3 no.2
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• pp.77-83
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• 1996

Photosensitization via the singlet oxygen ($^1O_2$) mechanism by the binuclear iron-sulfur center, denoted as [2Fe-2S], was investigated, using a highly purified ferredoxin (Fd) preparation from spinach leaves. Since the apoprotein of Fd contains a good number of amino acid residues that are readily reactive with $^1O_2$ and thus interfere with the detection of $^1O_2$ generated from [2Fe-2S], we attempted to deprive the $^1O_2$-sensitive residues of their $^1O_2$-scavenging capacity as much as possible by treating Fd with rose bengal plus 550 nm monochromatic light and thereby photooxidatively degrading these residues. The photochemically modified Fd was found to keep the structural integrity of its Fe-S group virtually unaffected by the treatment. By employing chemical trap method for measurement and examining the kinetic effects of azide and deuterium oxide on the reactions of $^1O_2$ with various trap compounds, we were able to demonstrate that [2Fe-2S] indeed acts as a photosensitizer via $^1O_2$. Further, the minimum quantum yield of $^1O_2$ production by [2Fe-2S] was estimated to be 0.0047.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.168-168
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• 2012

본 연구에서는 Molybdenum oxide (MoOx)-doped 4,4',4"-tris[2-naphthyl(amino)] triphenylamine(2-TNATA)의 P-doping에 의한 hole ohmic contact과 fullerene (C60)/lithium (LiF)의 electron ohmic contact에 의한 All Ohmic contact를 이용한 유기 발광 다이오드 (OLEDs)의 광저항 특성의 향상을 설명한다. 이 소자의 성능은 MoOx-doped 2-TNATA의 두께와 도핑농도에 큰 영향을 받는다. glass/ITO/MoOx-doped 2-TNATA (100 nm)/Al 구조의 소자에서 MoOx-doped 2-TNATA 도핑 농도가 25%에서 75%로 증가할수록 hole only device의 hole ohmic 특성이 향상됐다. 그 이유는 p-type doping effect 때문이다. 또한 photoemission spectra 분석결과, p-type doping effect는 hole-injecting barrier 높이는 낮추고, hole conductivity는 향상되었다. 이것은 2-TNATA에 도핑된 MoOx의 전하전송 콤플렉스의 형성으로 hole carrier의 수가 증가하여 발생되었다. MoOx-doped 2-TNATA의 hole ohmic contact과 fullerene (C60)/lithium fluoride (LiF)의 electron ohmic contact 으로 구성된 glass/ITO/MoOx-doped 2-TNATA (75%, 60 nm)/NPB (10 nm)/Alq3 (35 nm)/C60 (5 nm)/LiF (1 nm)/Al (150 nm)의 소자구조는 6,4V에서 127,600 cd/m2 최대 휘도와 약 1,000 cd/m2에서 4.7 lm/W의 높은 전력 효율을 보여준다.

• Korean journal of food and cookery science
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• v.16 no.5
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• pp.390-393
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• 2000

Desmutagenic effects of water-soluble and ethanol-soluble extracts of dried green tea toward the mutagenicity of 4-nitroquinoline-N-oxide(4-NQO) and 3-Amino-1,4-dimethyl-5H-pyrido［4,3-b］indole(Trp-P-1) in streptomycin-dependent SD510 strains of Salmonella typhimurium TA98 were investigated. Inhibition effects toward the mutagenicity of 4-NQO and Trp-P-1 of water-soluble and ethanol-soluble extracts from green tea were high as increase of concentration of extracts. Desmutagenic effects toward 4-NQO of water-soluble and ethanol-soluble extracts from green tea harvested in May and August were up to 93% in 1,000 $\mu\textrm{g}$ of extract/plate. Desmutagenic effects toward Trp-P-1 of ethanol-soluble extracts from green tea were 53.3∼92.1%, but the effects of water-soluble extracts decreased as increase of concentration of extracts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.350-358
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• 1998

The antimutagenic and anticancer activities of glycoprotein(GP) and chondroitin sulfate(CS) from sea cucumbers were studied using Ames mutagenicity test and human cancer cells culture test. The GP's inhibitory effect toward aflatoxin B1(AFB1) and 3, 2'-dimethyl-4-amino-biphenyl(DMAB) increased with the higher added concentrations up to 5% level(w/w) regardless fractionation methods. The GP from sea cucumbers through DEAE-cellulose column chromatography showed an inhibitory effect ranged from 84 to 98%, and the maximum antimutagenicities resulted in red sea cucumber with 98% (AFB1) and 95% (DMAB). But 5% level of CS from various sea cucumbers had an inhibitory effect toward those both indirect mutagens ranged from 79% to 85%. However, in case of direct mutagens(N-methyl-N'-nitro-N-nitrosoguanidine, MNNG and 4-nitroquinoline-1-oxide, 4-NQO), the GP's inhibitory effect was 55∼78% and the CS had a low inhibitory effect(58∼70%) at the added level of 5%. The GP from sea cucumbers exhibited the strong inhibitory effects with 89∼95% and 82∼92% on the growth of HT-29 human crcinoma cells and AZ-521 human gastric cancer cells (at 5% level).

• Bulletin of the Korean Chemical Society
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• v.24 no.7
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• pp.943-947
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• 2003

We have studied the migration behavior of single-stranded DNA using capillary gel electrophoresis under various conditions. It was found that optimum electric fields should be less than 150 V/cm for the good tradeoff between the separation time and the resolution. It seems that the gel matrix with the combination of different polymer average molecular weights is important to extend the maximum readable DNA bases. The total gel concentration less than 3.1% in the mixed gel system showed good separation efficiency up to 600 bases. The best result was obtained with the poy(ethylene)oxide (PEO) gel concentration of 1.2% of Mr 8,000,000 and 1.8% of Mr 600,000. We observed that the capillary length between 50 cm to 100 cm (effective length) should be employed for the optimization between the total DNA migration time and the maximum readable length. A trizma base-boric acid-ethlyenediaminetetraacetic acid (EDTA) (TBE) buffer was commonly used for DNA sequencing, but we found that 3-[tris(hydroxymethyl)methyl amino]-1-propane sulfonic acid (TAPS) buffer worked as well for the single-stranded DNA separation. Especially, TAPS buffer showed a good resolution for very short DNA bases (1 to 30 bases).

• YAKHAK HOEJI
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• v.56 no.1
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• pp.42-47
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• 2012

Soluble epoxide hydrolase (sEH) is a metabolic regulator of epoxyeicosatrienoic acids (EETs). EETs have many beneficial effects, vasodilation, anti-diabetes, anti-inflammation, cardiovascular protection, renal protection. Therefore, selective sEH inhibitors have a potential for treating these diseases. In the present study, screening methods for sEH inhibitors using PHOME ((3-phenyl-oxiranyl)-acetic acid cyano-(6-methoxynaphthalen-2-yl)-methyl ester) and 14-15-EET as substrates were established. To determine selectivity, microsomal epoxide hydrolase (mEH) inhibition assay was also developed using styrene oxide as a substrate of microsomal epoxide hydrolase. Our results obtained from 12-[[(tricyclo[3.3.1.13,7]dec-1-ylamino)carbonyl]amino]-dodecanoic acid (AUDA) used as a positive sEH inhibitor and valpromide used as a positive mEH inhibitor showed that these methods are useful for discovery of drug candidates.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.1
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• pp.19-25
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• 2001

This study was performed to examine the antimutagenic and cytotoxic effects of potato vinegar and commercial vinegars(cider, brown rice, persimmon vinegars) on Salmonella typhimurium TA98, TA100 and cancer cell lines using Ames test and cytotoxicity assay, respectively. In Ames test, all vinegars did notexhibit any mutagenicity , but showed substantial inhibitory effects against N- methyl - N -nitro - N- nitrosog -uanidine(MNNG) , 4-nitroquinoline-1-oxide(4NQO), 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indol(Trp-P-1)and benzo( $\alpha$ )pyrene(B( $\alpha$ )P). The number of revertants per plate decreased significantly when these vinegars(80 ug/plate) were added to the assay system using TA100 strain. Especially, potato vinegar(80 ug/plate) showed high inhibition rate of 69.9% against mutagenicity of B( $\alpha$ )P on TA100 strain. In the cytotoxicity assay, these vinegars also showed prominent cytotoxic activity against human cancer cell lines. Potato vinegar(10 ug/well) showed the strongest cytotoxic effect against HT1080 (fibrosacoma cell) andK562 ( myelogenous leukemia) at the same concentration when compared with other vinegars.

• Korean Journal of Materials Research
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• v.19 no.1
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• pp.44-49
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• 2009

Conjugated nanocrystals using CdSe/ZnS core/shell nanocrystal quantum dots modified by organic linkers and glucose oxidase (GOx) were prepared for use as biosensors. The trioctylphophine oxide (TOPO)-capped QDs were first modified to give them water-solubility by terminal carboxyl groups that were bonded to the amino groups of GOx through an EDC/NHS coupling reaction. As the glucose concentration increased, the photoluminescence intensity was enhanced linearly due to the electron transfer during the enzymatic reaction. The UV-visible spectra of the as-prepared QDs are identical to that of QDs-MAA. This shows that these QDs do not become agglomerated during ligand exchanges. A photoluminescence (PL) spectroscopic study showed that the PL intensity of the QDs-GOx bioconjugates was increased in the presence of glucose. These glucose sensors showed linearity up to approximately 15 mM and became gradually saturated above 15 mM because the excess glucose did not affect the enzymatic oxidation reaction past that amount. These biosensors show highly sensitive variation in terms of their photoluminescence depending on the glucose concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.322-328
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• 2000

This study was performed to determine the antimutagenic and cytotoxic effect of the Phellinus linteus methanol extract on Salmonella typhimurium TA98, TA100 and human cancer cell lines. In the Ames test, methanol extract of P. linteus alone did not exhibit any mutagenicity but showed substantial inhibitory effects against mutation induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), 4-nitroquinoline-nitroquinoline-1-oxide(4NQO), 3-amino-1,4-dimethyl-5H-pyrdo[4,3-blindol(Trp-P-1) and benzo(α)pyrene(B(α)P). The methanol extracts of P. linteus(200㎍/plate) showed approximately 78.3%, 78.7% and 88.1% inhibitory effect on the mutagenesis induced by 4NQO, Trp-P-1 and B(α)P. The anticancer effects of P. linteus extract against human breast adenocarcinoma(MCF7), human lung carcinoma (A549), human fibrosarcoma (HT1080), human hepatocelular carcinoma (Hep3B) and human epitheloid carcinoma (HeLa) were investigated. The treatment of 1mg/mL P. linteus extracts had the highest cytotoxicity against MCF7 (92.0%), followed by Hep3B (84.9%), A549 (84.2%) and HT1080 (82.9%). In contrast 1mg/mL treatment of P. linteus extracts had only 10∼40% cytotoxicity on normal human liver cell (WRL68).