• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.313-313
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• 2009

OLED 소자는 직접발광, 광시야각, 그리고 빠른 응답속도 때문에 동영상에 적합하여 최근 각광받고 있는 디스플레이장치 중의 하나이다. OLED 소자의 양극재료로는 높은 광투과율과 $\sim10^{-4}{\Omega}\;cm$ 수준의 낮은 전기 비저항을 갖는 ITO (Sn-doped $In_2O_3$)가 널리 사용되고 있다. 하지만 원료 물질인 인듐의 수급량 부족으로 인한 문제점과 독성, 저온증착의 어려움, 스퍼터링시 음이온 충격에 의한 막 손상으로 저항의 증가의 문제점이 있고, 또한 액정디스플레이의 투명전극으로 사용될 경우 $400\;^{\circ}C$정도의 높은 온도와 수소 플라즈마 분위기에서 장시간 노출 시 열화로 인한 광학적 특성변화가 문제가 된다. 반면에 Al이 도핑 된 ZnO (AZO)박막은 넓은 밴드갭 (3.37eV)와 400nm에서 700nm 사이의 가시광 영역에서 80% 이상의 우수한 투과성을 지니고 있다. 특히 Al이 도핑된 ZnO는 박막의 전기적 특성이 크게 향상되어 디스플레이나 태양전지로의 응용이 가능하다. 또한 비교적 낮은 비용과 플라즈마에서의 안정성, 무독성, 그리고 전기전도성과 같은 많은 이점이 있다. 그 결과 AZO 박막은 ITO기판을 대안하는 지원물질로 활발히 연구가 진행되고 있다. 본 연구에서는 TCO 박막의 면 저항과 표면 거칠기에 따른 OLED 소자의 특성을 분석하였다. ITO와 AZO 박막은 챔버 내 다양한 가스 분위기(Ar, Ar+$O_2$ and Ar+$H_2$)에서 R.F Magnetron Sputtering방법으로 증착하였다. TCO 박막의 구조적인 이해를 돕기 위해서 X-ray diffraction 과 FESEM으로 분석하였다. 광학적 투과도와 박막의 두께는 ultraviolet spectrophotometer (Varian, cary-500)와 surface profile measurement system으로 각각 측정하였다. 면저항 charge carrier 농도, 그리고 TCO 박막의 이동도와 같은 전기적특성은 four-point probe와 hall effect measurement(HMS-3000)로 각각 측정하였다. TCO 박막의 표면 거칠기 조절을 위해 photo lithography 공정을 사용하여 TCO 박막을 화학에칭 하였다. 미세사이즈 패턴 마스크가 사용되었으며 에칭의 깊이는 에칭시간에 따라 조절하였다. TCO 박막의 표면 형태는 FESEM과 AFM으로 관찰하였다. 투명전극으로 사용되는 ITO 및 AZO 기판 상용화를 위해 ITO 및 AZO 기판 위에 ${\alpha}$-NPB, Alq3, LiF, Al 의 순서로 증착 및 패터닝함으로써 OLED 소자를 제작하였다. 전류밀도와 전압 그리고 발광휘도와 전압과 같은 전기적 특성은 spectrometer(minolta CS-1000A)를 이용하여 측정하였다.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.500-504
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• 2006

Haptoglobin (Hp) is an acute phase protein, and its plasma level increases consistently in response to inflammation. To investigate the biological role of Hp in lung epithelial cells, the gene expressions of cyclooxygenase-2 (COX-2) and inflammatory cytokines were analyzed using human Hp gene-transfected A549 cells. Western blot analysis showed that COX-2 expression was markedly increased in Hp DNA-transfected cells (stable transfection and transient transfection) compared with that in vehicle DNA-transfected cells. When the Hp-expressing cells were treated with $1{\mu}g/ml$ of LPS or 100 U/ml of $IL-1{\beta}$ for 24 hr, the COX-2 expression was synergistically up-regulated. ACP-based PCR data demonstrated the Hp decreased SPARC expression, but increased IL-4 and S100AI expressions. These findings suggest that the Hp acts as a pro-inflammatory mediator in lung inflammation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.318-323
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• 2004

This study has been carried out to investigate the effect of the beverage contained Radix puerariae (15%) and Bambusae caules in Liquamen Phyllostachyos (1%) on the alcohol administered mouse. The control group was treated with alcohol (40% alcohol, 8.0 mL/kg of body weight), experimental group 1 (Exp.1) was administered with beverage (8.0 mL/kg of body weight) before alcohol treatment, and experimental group 2 (Exp.2) was administered with beverage after alcohol treatment. Blood alcohol concentrations were decreased by 11% (in Exp. 1) and 17% (in Exp. 2) compared with control group. The concentrations of serum aspartate aminotransferase (AST) were slightly increased in Exp. 1 and Exp.2, but alanine aminotransferase (ALT) levels were not changed compared with control group. Mn-Superoxide dismutase activity was increased by about 70% in the experimental groups in comparison to control group. The Exp. 1 and Exp. 2 contained more periodic-acid Schiff (PAS)-positive materials than the control group. Electron microscopical observations showed that, cell organelles of hepatocytes were more disoriented in the control group than in Exp. 1 and Exp. 2. These results suggest that the beverage contained Radix puerariae and Bambusae caules in Liquamen Fhyllostachyos is a safe and effective therapeutic agent for alcohol abuse.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.625-633
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• 2016

Allium hookeri is known as a healthy food since it contains larger amounts of sulfur compounds than commonly known alliaceous plants. The antioxidant and anti-inflammatory effects of A. hookeri were compared between two types of extracts, $80^{\circ}C$ water and 95% ethanol extracts of A. hookeri roots. A. hookeri root 95% ethanol extracts displayed superior total polyphenol content, antioxidant activity [1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical scavenging activity], and anti-inflammation activity than those of water extracts (P<0.05). We studied the effects of A. hookeri root 95% ethanol extracts (95% ethanol extracts group: AHE) on acute alcohol-induced intoxication in mice. AHE [250, 500, and 1,000 mg/kg body weight (BW)/d] was orally administered to the study group once a day for 1 week. On the last day of AHE treatment, 40% ethanol (10 mL/kg BW) was orally administered to induce acute liver injury. The blood alcohol concentration of mice treated with AHE was significantly lower compared to the control group (P<0.05). The levels of hepatic aspartate aminotransferase and alanine aminotransferase were lower in the AHE-treated group than the control group (P<0.05). The RT-PCR results for alcohol dehydrogenase and aldehyde dehydrogenase measured based on mRNA in liver tissues showed that enzyme activities were higher in the AHE-treated group than in the control group at a low blood alcohol concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1708-1716
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• 2016

The Akt/mammalian target of the rapamycin (mTOR) pathway is activated in the majority of human cancers. Activation of the Akt/mTOR pathway confers resistance to many types of cancer therapy. In this study, we evaluated the apoptotic effect of ethanol extract of Artemisia annua L. through down-regulation of Akt signal pathways and the mitochondrial pathway in hepato-carcinoma cells (HepG2). A. annua extract is known as a medicinal herb that is effective against cancer. We evaluated anti-proliferative activity by MTT-based viability assay and apoptotic effect by Annexin-V/PI staining, mitochondrial membrane potential (MMP), and caspase-3/7 activity as determined by flow cytometry. A. annua treatment led to loss of MMP, resulting in cytochrome c-inducible activation of caspase-3/7. Treatment with A. annua extract reduced activities of Akt/mTOR/anti-apoptotic proteins (such as Bcl-2 and $Bcl-X_L$), leading to increased activation of tumor suppressor p53 and pro-apoptotic proteins (such as Bax and Bak). We applied LY294002 (inhibitor of Akt) and rapamycin (inhibitor of mTOR) to determine the relationship between signal transduction of proteins associated with apoptosis. LY294002 and rapamycin significantly reduced cell viability and increased apoptosis. These results indicate that Bcl-2 and caspase-3 are key regulators in A. annua extract-induced apoptosis in HepG2 cells and are controlled through the Akt/mTOR signaling pathway.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.222-227
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• 2017

Red ginseng prepared from fresh 6-year-old ginseng treated with colloidal gold nanoparticles was extracted using hot water to evaluate its total phenolic and flavonoid contents, antioxidant capacity, and neuroprotective effects. Water extract of red ginseng treated with gold nanoparticles (WERGGN) had total phenolic and total flavonoid contents of 212.2 mg gallic acid equivalents/$^{\circ}Bx$ and 3.5 mg catechin equivalents/$^{\circ}Bx$, respectively. The antioxidant capacities of WERGGN measured using ABTS, DPPH, and ORAC assays were 272.3, 141.2, and 868.4 mg vitamin C equivalents/$^{\circ}Bx$, respectively. The WERGGN showed protective effects on the viability of neuron-like PC-12 cells against oxidative stress induced by hydrogen peroxide in a dose-dependent manner, partly because of a reduction in intracellular oxidative stress. Acetylcholinesterase and butyrylcholinesterase, which degrade the neurotransmitter acetylcholine to terminate neurotransmission, were inhibited by treatment with WERGGN. These results suggest that WERGGN is useful as a functional material to decrease oxidative stress and neuronal damage.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.546-554
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• 2020

Natural food additives have recently attracted attention as alternatives to synthetic additives. However, little information is available regarding their potential toxicity. In this study, we evaluated ten different natural food additives that are widely used in commercial foods in South Korea based on their actual usage level and daily intake. The results showed that none of the tested natural additives exhibited cytotoxicity in terms of inhibition of cell proliferation/viability and lactate dehydrogenase leakage. Additionally, the tested natural food additives did not generate intracellular reactive oxygen species (ROS), whereas they significantly decreased intracellular ROS levels produced by hydrogen peroxide. Moreover, none of the tested natural additives affected cell proliferation and viability in 2D and 3D intestinal epithelium models. Taken together, the ten natural food additives did not exhibit cytotoxicity in their actual usage levels. These findings can be used to further assess the toxicity of natural food additives.

• Korean Journal of Animal Reproduction
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• v.27 no.1
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• pp.9-14
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• 2003

The pBT-L transgenic mice carrying human TPO gene in conjunction with bovine $\beta$-casein promoter express human TPO in milk during lactation. In this study, stability of germ line transmission and expression of pBT-L transgene integrated into host chromosome were monitored up to generation F10 of transgenic pBT-L/15 line. When male mouse of generation F8 was crossbred with normal females, approximately half of offsprings (51.3$\pm$18.98%) were identified as transgenic mice. Generation F9 and F 10 mice also showed similar transmission rates (43.8$\pm$18.98% and 71.4$\pm$26.98%, respectively), implying that pBT-L transgene can be transmitted stably up to long term generation in the transgenic mice. Expression levels of human TPO from milk of generation F9 and F10 mice were 1.1$\pm$0.33 mg/ml and 1.1 $\pm$0.45 mg/ml, respectively, which are similar to expression level of generation F2 mice. In conclusion, our results suggest that transgenic animals once established will continuously pass their transgenes to the progeny through the breeding program with the same productivity of human protein in their milk.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.586-593
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• 2004

Efficient extraction method of crude protein-bound polysaccharide (CPBP) from Agaricus blasei Murill was established. CPBP yields by ultrasonic and hot water extractions were 13.0 and 7.8%, respectively. Pressure extraction for 3 hr gave the highest ${\beta}-glucan$ content; no significant difference was observed between 2 and 3 hr extraction. Four volumes added ethanol gave the highest yields of CPBP and ${\beta}-glucan$ contents at 10.89 and 35.97%, respectively. Decomposition temperature of CPBP was $240-365^{\circ}C$, showing relatively good thermal stability. In SRB (sulforhodamine B) assay, CPBP treatment at $1,000\;{\mu}g/mL$ for 72 hr inhibited proliferations to A549, MCF-7, and AGS cancer cells by 43.9, 21.4, and 32.5%, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.507-511
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• 2005

울돌목은 조류발전의 세계적인 최적지로 꼽히고 있으며 서해와 남해의 점이 지대로서 조류에 의해 해양 생물 군집의 대량 이동이 빈번한 곳이라 할 수 있다. 조류 발전 시설인 터빈의 가동은 물리적인 충격에 의해 해양 생물의 생태-생리 반응에 영향을 미칠 가능성이 있다. 네트를 이용한 1차 조사에서 터빈 가동에 의한 동물플랑크톤의 순 사망률은 $44.3\%$로 나타났다. 1차 조사 이 후 다이아프램 펌프를 이용한 조사 결과 중 출현 개체수가 높았던 조사에서 전체 동물플랑크톤의 순 사망률은 각각 $7.3\%,\;5.8\%$를 나타내었고, 요각류는 각각 $4.4\%,\;5.2\%$를 나타냈다. 물리적인 충격을 인위적으로 가한 실험에서 스트레스를 받은 요각류 Acartia hongi의 알 생산은 스트레스를 받지 않은 것보다 $1.8\~2.3$배 낮은 경향을 보였다. 본 조사에서 동물플랑크톤이 낮은 사망률을 보골 이유는 작은 크기의 생물이 우점하였기 때문이며 조사 결과에서 몸체가 비교적 단단하고 크기가 작은 요각류는 상대적으로 약한 부유유생보다 높은 생존율을 보였다. 울돌목 조사 해역에서 출현한 동물플랑크톤은 크기가 작아 터빈의 물리적인 충격에 의한 사망률은 낮을 수 있으나 순간적으로 강한 스트레스를 받는다면 재생산을 포함한 생리활동이 저하될 수 있음을 보였다. 네트 및 펌프를 이용한 조사 결과에서 네트에 의한 채집은 터빈의 영향뿐만 아니라 빠른 유속으로 인하여 네트가 받는 압력에 의해 생물체가 손상되는 양상이 높아 사망률이 높았던 것으로 보인다. 그러나 다이아프램 펌프는 생물 채집 시 오류를 최소화하는 장점은 있으나 채집의 장시간에 비해 매우 적은 생물량이 채집되는 단점을 보였다TEX>$96.5\%$에 미달하는 문제는 식물성 원료유로 제조한 고순도 바이오디젤과 혼합 사용하거나 감압 증류 공정을 통해 고농도의 폐식용유 바이오디젤을 제조하여 해결 가능하다. 대전시 신성동 소재의 음식점에서 수거한 폐식용유를 원료로 하여 생산한 바이오디젤의 차량 배출가스 실증 테스트 결과 경유 차량의 주 오염물질인 PM과 Soot 및 기타 오염물질의 배출량은 감소하였으나 NOx의 배출량은 약간 증가하는 것으로 나타났다구와 이해를 바탕으로 보존대책이 마련되어야 한다.되었다. 이런 모든 시편들을 각 탈염방법에 따라 탈염처리한 후 XRD와 SEM-EDS으로 분석한 결과 인철광과 침철광은 어떠한 변화도 보이지 않았고, 다만 적금광으로 동정된 시편만이 잔존하지 않았다. 철기 제작별 $Cl^-$ 이온 추출량과 탈염효과에 대한 비교 실험은 이온 크로마토그래피 분석 결과와 마찬가지로 단조 철제유물이 주조 철제보다 $Cl^-$ 이온을 많이 가지고 있었으며, 탈염 처리 후에는 $Cl^-$ 이온은 전혀 발견되지 않았다. 이상의 결과 $K_2CO_3$와 Sodium 용액은 탈염처리에서 가장 적합한 탈염처리 용액으로 알수가 있었으며 특히 어떠한 탈염 용액으로 유물을 처리한다 해도 철제유물에 생성된 부식물은 제거되지 않는다는 것을 알게 되었다. 따라서 보존처리자는 유물 표면의 부식 상태만을 보고 처리하기 보다는 철기제작물로 고려하여 처리하는 것이 필요하다. 또한 금속에 부식을 야기시키는 $Cl^-$ 이온과 부식물을 완전하게 제거하여 탈염처리를 하는 것이 유물 부식을 최대한 지연시킬 수 있는 것이라 생각된다.TEX>$88\%$)였다.(P=0.063). 결론: 본