• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.50.2-50.2
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• 2018

The demand for steady and dependable power sources is very high in the field of sustainable energy because of the limited amount of fossil fuels reserves. Among several sustainable alternatives, solar energy may be the most efficient solution because it constitutes the largest renewable energy source. So far, the only practical way to store such large amounts of energy has been to use a chemical energy carrier likewise a fuel. In various solar energy to power conversion systems, the photoelectrochemical (PEC) splitting of water into hydrogen and oxygen by the direct use of solar energy is an ideal process. It is a renewable method of hydrogen production integrated with solar energy absorption and water electrolysis using a single photoelectrode. Previous studies on photoelectrode films for PEC water splitting cells have been mainly focused on synthesizing oxide semiconductors with wide band gaps, such as TiO2(3.2eV), WO3(2.8eV), and Fe2O3(2.3eV). Unfortunately, these pristine oxide photoanodes without any catalysts have relatively low photocurrent densities because of the inherent limitation of insufficient visible light absorption due to the wide bandgap. Specifically, there is a tradeoff between high photocurrent and photoelectrochemical corrosion behavior, which is representative of figures of meritf or PEC materials.

• 한국식물병리학회지
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• 제14권2호
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• pp.136-144
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• 1998

Many cloves of native cultivated garlics in Korea were found to be infested by mites when observed with stereo-microscope. The mite was identified by light and scanning electron microscopic observation as Aceria tulipae. Surveying viruses from the vegetatively propagated garlic, highly flexuous, filamentous particles (700∼800 nm) were detected in Aceria tulipae, local lesions of Chenopodium murale after sap transmissions, mosaic garlic leaves inoculated with mite-borne virus by transmission of Aceria tulipae and naturally infected garlic leaves. The mite-borne virus isolated did not react with antisera of aphid-borne potyviruses (LYSV-G, LYSV-L, WoYSV) or carlavirus (GLV), but reacted with antisera of garlic mite-borne viruses (GV-C, GMbMV). In ultratin sections of mite-borne virus infected garlic tissues, aggregates of virus particles and membrane proliferations were found in the parenchyma cells, but cytoplasmic cylindrical inclusions were not observed. Heavily mite-infested plants showed streaking and malformation due to mite feeding. The mite-borne virus was identified as garlic mite-borne mosaic virus (GMbMV), the mite-borne genus Rymovirus of the Potyviridae by mite transmission, morphology of virus particles, serological relationships, host range, distribution pattern of virus particles and inclusion bodies in the infected cells. The results demonstrate that mite-borne virus is one of the major viruses infecting native cultivated garlic plants showing mosaic or streak symptoms in Korea.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.141-145
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• 2007

Due to their excellent catalytic activity with respect to methanol oxidation on platinum at low temperature, platinum nanosized catalysts have been a topic of great interest for use in direct methanol fuel cells (DMFCs). Since pure platinum is readily poisoned by CO, a by-product of methanol electrooxidation, and is extremely expensive, a number of efforts to design and characterize Pt-based alloy nanosized catalysts or Pt nanophase-support composites have been attempted in order to reduce or relieve the CO poisoning effect. In this review paper, we summarize these efforts based upon our recent research results. The Pt-based nanocatalysts were designed by chemical synthesis and thin-film technology, and were characterized by a variety of analyses. According to bifunctional mechanism, it was concluded that good alloy formation with $2^{nd}$ metal (e.g., Ru) as well as the metallic state and optimum portion of Ru element in the anode catalyst contribute to an enhanced catalytic activity for methanol electrooxidation. In addition, we found that the modified electronic properties of platinum in Pt alloy electrodes as well as the surface and bulk structure of Pt alloys with a proper composition could be attributed to a higher catalytic activity for methanol electooxdation. Proton conducting contribution of nanosized electrocatalysts should also be considered to be excellent in methanol electrooxidation (Spillover effect). Finally, we confirmed the ensemble effect, which combined all above effects, in Pt-based nanocatalsyts especially, such as PtRuRhNi and $PtRuWO_{3}$, contribute to an enhanced catalytic activity.

• 한국산업보건학회지
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• 제27권3호
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• pp.193-200
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• 2017

Objectives: This study was performed to evaluate the neurototoxicity of the environmental pollutant lead acetate(LA) and the protective effect of the D-2-amino-5-phosphonovaleric acid(APV), N-methyl-D-aspartate(NMDA) receptor antagonist on LA-induced cytotoxicity in cultured C6 glioma cells. Materials and Methods: For this study, cell viability in cultured C6 glioma cells was assessed by XTT assay and antioxidative effect, such as lactate dehydrogenase(LDH) activity, by LDH detection kit. Results: LA significantly decreased cell viability in a dose-dependent manner, and the XTT50 value was determined to be 33.3 uM of LA. The cytotoxicity of LA was deemed highly toxic according to Borenfreund and Puerner's toxic criteria. The vitamin E antioxidant significantly increased cell viability damaged by LA-induced cytotoxicity in these cultures. For the protective effect of APV on LA-induced cytotoxicity, APV significantly increased not only cell viability, but also inhibition of LDH activity. From these results, it is suggested that oxidative stress is involved in the neurotoxicity of LA, and APV effectively protected against LA-induced cytotoxicity via an antioxidative effect as an inhibotory activity of LDH. Conclusions: Natural resources like APV may be putative therapeutic agents for the toxic diminution of environmental pollutants such as LA correlated with oxidative stress.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
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• pp.199-207
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• 1998

Ginseng saponin (G5) purified from Panax ginseng, increase renal blood flow in rats. Nitric oxide (NO) is thought to be a substance endogenously released by G5 in preconstricted lungs and cultured endothelial cells. The present study aims to determine whether G5 could stimulate endogenous 1'elease of NO in rat kidney and urine levels of the stable NO metabolites, nitrite (NO,) and nitrate (NO,) and urinary COMP levels were measured 8 hr after a single intraperitoneal injection of GS (200 mg/kg) Into rats. The effects of the WO synthesis inhibitor, Nu-nitro-L-arginine methyl ester, .1nd the NO precursor, L-arginine, on the G5-induced changes were also determined. The activity of NO synthase, as determined by conversion of ('"C)-L-arginine to ('"C)-L-citrulline, in whole kidney, glomeruli and cortical tubules were also investigated. A single injection of GS resulted in endogenous production of NO as reflected by increase in serum and urine levels of N021N03 and urinary cGMP levels, which were inhibited by the addition o ( N-nitro-L-arginine methyl ester and restored fly L-arginine. GS also stimulated the activity of NO synthase in whole kidney as well as glomeruli and cortical tubules, and Nu-nitro-L-arginine methyl tilter significantly prevented this increase. In conclusion, GS stimulates endogenous NO production and thus, may play a protective role 1 11 the kidney by modulating renal blood flow.

• 대한세포병리학회지
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• 제18권2호
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• pp.157-160
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• 2007

Granular cell tumor (GCT) of the breast is a rare clinical entity, and is believed to be of schwannian origin and to follow a benign clinical course. A 50-year-old woman presented with a slowly growing mass in the right breast. Fine needle aspiration cytology revealed a cellular smear containing isolated or clustered cells showing round to oval nuclei with abundant oncocytic granular cytoplasm. Nuclei showed a fine granular chromatin pattern and occasional small single nucleoli. Cell boundaries were poorly defined, and naked nuclei were frequently found, Histologically, the tumor showed features of typical GCT, and immunohistochemical staining findings strongly supported the diagnosis. The present study demonstrates that GCT of the breast can mimic malignant lesions of breast both clinically and radiologically. The recognition of its cytologic features and suspicion of this lesion would undoubtedly aid the correct diagnosis of mammary GCT.

• 대한한방내과학회지
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• 제26권1호
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• pp.182-198
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• 2005

Object : This study was designed to research whether the protection and inhibitory effects of cardiovascular diseases in L-NAME induced rat or ECV 304 cell lines through the Cell morphological pattern, Tunel assay, LDH activity, heart rate, blood pressure and immunohistochemistric analysis by Boonsimgieum water extract Methods : Nitric oxide(NO) play an important role in normal and pathophysiological cells including as a messenger molecule, neurotransmitter, microbiocidal agent, or dilator of blood vessels and artheriosclerosis, hypertension, myocardial infarction, respectively. Endothelial cell products can modulate the magnitude of a response to a vasoconstrictor, as evinced by the greater constriction after endothelium removal or NO synthesis blockade. To investigate that Boonsimgieum in the potential contribution of the levels of nitric oxide generated by endothelial nitric oxide synthase (eNOS) and the mechanisms of protection against NG-nitro-L-arginine methyl ester (L-NAME), human ECV 304 cells, which normally do not express eNOS, were expressed by L-NAME. L-NAME stimulated rat or cells were found to be resistant to injury and delayed death following the Boonsimgieum. Inhibition of nitric oxide synthesis abolished the protective effect against L-NAME, thrombin and collagen exposure. Interestingly, such effects have been observed during stimulation with agents such as phenylephrine and KCl on L-NAME mediate rats, were damaged by the NOS inhibitor L-NAME. Result : As the result of this study, In group, the anti-apoptosis and necrosis in the cardiovascular system have a potential capacity for prevented, protected and treating the diseases of cardiovascular system, against the necrosis of rat and ECV 304 cells with Caspase 3 and calpain expression by L-NAME is promoted. Conclusion : these results demonstrate neuroprotective and memory enhancing effects of ZIBU, suggesting its beneficial actions for the treatment of AD.

• 대한한의학방제학회지
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• 제12권2호
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• pp.175-202
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• 2004

Nitric oxide(NO) play an important role in normal and pathophysiological cells including as a messenger molecule, neurotransmitter, microbiocidal agent, or dilator of blood vessels and artheriosclerosis, hypertension, myocardial infarction, respectively. To investigate that Ondamtang in the potential contribution of the levels of nitric oxide generated by endothelial nitric oxide synthase (eNOS) and the mechanisms of protection against L-NAME, human ECV304 cells, which normally do not express eNOS, were expressed by L-NAME. L-NAME stimulated rat or cells were found to be resistant to injury and delayed death following the Ondam-tang. Inhibition of nitric oxide synthesis abolished the protective effect against L-NAME, thrombin and collagen exposure. Interestingly, such effects have bee observed during stimulation with agents such as KCl on L-NAME mediate rats, were damaged by the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Cardiovascular diseases is one of the blood vessels and renin-angiotensin system dynfunction. So we studied on herbal medicine that have a relation of vessels endothelium necrosis. In Oriental Medicine, Ondam-tang has been used for disease in relation to cardiovascular system. We studied on the protection and inhibitory effects of cardiovascular diseases in L-NAME induced rat or ECV304 cell lines through the Cell morphological pattern, Tunel assay, LDH activity, heart rate, blood pressure and immunohistochemistric analysis by Ondam-tang. As the result of this study, In group, the anti-apoptosis and necrosis in the cardiovascular system have a potential capacity for prevented, protected and treating the diseases of cardiovascular system, against the necrosis of rat and ECV304 cells with eNOS and calpain expression by L-NAME is promoted.

• 한국수산과학회지
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• 제39권3호
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• pp.297-302
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• 2006

황점볼락, Sebastes oblangus의 인공종묘의 성분화 과정 및 성결정을 조사하기 위해 출산 직후부터 370일령까지 조사하였다. 출산 직후 난황기 자어(7.10-7.77 mm)에서 시원생식세 포와 생식융기는 분리된 채 중신관과 장간막 사이에 나타났고, 출산 후 5일령 전기자어(7.12-9.68 mm)에서는 서로 융합하였으며, 출산 후 45일령 후기자어(18.6-20.4 mm)까지는 미분화 생식소 상태였다. 출산 50일 치어(20.0-24.5 mm)에서 생식소 전단부에서 양쪽 끝의 체세포 조직이 분열 신장되어 난소의 분화가 시작되어 60일 치어(25.5-32.0 mm)에서 완전 한 난소강이 형성되었다. 출산 80일령 치어(37.3-47.2 mm)의 난소에서 난원세포가 감수분열을 개시하여 염색인기 난모세포(chromatin nucleolus oocyte) 로 발달하기 시작하였다. 이 후 일령이 증가하여 130일령(68.0-86.0 mm)에서 주변인기(perinucleolus stage)의 난모세포가 나타났으며, 출산 후 370일령(101.0-116.0 mm)에서 전난황형성기의 난모세포들이 출현하였다. 황점볼락 인공종묘의 성비 조사결과 난소분화 완료 후에 암컷만 나타나 출산후 100일까지 자연수온보다 높은 수온에 의해 전암컷화 된 것으로 추정된다.

• 생물환경조절학회지
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• 제4권1호
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• pp.50-58
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• 1995

환경변화에 따른 작물생체의 반응을 근속하고 정확히 해석하기 위하여, 로드셀과 마이크로컴퓨터를 이용하여 수경조건에서 생체중을 비파괴적으로 연속측정할 수 있는 시스템을 개발 하였다. 또한 이 시스템을 이용하여 양액의 이온농도 및 명암 조건에 따른 상추의 생장반응을 조사 하였던 바, 그 결과를 요약하면 다음과 같다. 가. 작물의 생체중을 비파단 연속적으로 측정할 수 있는 이 장치의 측정오차는 측정범위 0-2000g에서 0.05%인 土1.0g 이하로 나타났다. 나. 로드셀에서 출력된 지시중량은 수면위의 생체중량과 잘 일치하였다. 다. 상추의 생체중은 정식후 18일에 정식 당시에 비해서 44배 정도 증가하였고, 상대생장율은 정식후 5일까지는 미약하였으나 이후에 급격히 높아져 정식후 13일에 최대에 달하여 29.6% day$^{-1}$ 이었다. 정식후 18일간의 상대생장율은 10.7-29.6% day$^{-1}$ 범위에 있었다. 라. 양액의 무기 이온 농도에 따른 상추의 생장량은 EC 1.4-2.2mS/cm 에서 가장 높았으며, EC 0.7 이하나 2.8 이상에서는 떨어졌는데, 특히 지하부의 생장량은 2.8 이상의 고농도에서 현저히 낮았다. 마. 양액의 이온 농도에 따른 생체중량의 증가속도는 정식후 7일까지는 큰 차이가 없었으나 이후 차이가 나기 시작하여 정식후 20일에는 양액의 이온농도에 따라 큰 차이가 있었다. 사. 암흑 처리후 12시간 까지는 정상적으로 생체중이 증가 하였으며, 이후 78시간까지도 완만한 증가 양상을 나타내었으나 그 이후에는 감소하는 경향이었다. 아. 명조건에서 암조건으로 환경이 변화함에 따라 생체중량은 급격히 증가하였고 반대의 조건에서는 일시적인 생체중 감소가 있었는데, 이와 같은 양상은 생육단계, 광조사 시각 및 시간을 달리하 여도 같은 경향이었다.음은 물론 식물안정화를 위해 도입되는 식물의 생육 개선에 효과가 있음을 확인할 수 있었다.서 기후인자와 인간영향을 어떻게 분리해 낼 것인지에 대한 문제점이 남는다. 예를 들어 화분분석의 경우 1차적인 환경변화에 따른 식생조성변화를 반영한다. 인간이 활발한 농경활동을 하게 되면서 주변식생을 제거하게 되고, 제거된 나대지에는 재배작물과 잡초들이 자라게 된다. 그리고 이들 화분은 주변 소택지에 퇴적물과 함께 퇴적되어 화분분석 결과 벼과(科)(Gramineae)와 문화지표수종이라 부르는 여뀌속(屬)(Persicaria), 국화과(科)(Composite), 쑥속(屬)(Artemisia), 쐐기풀속(屬)(Urtica) 등의 화분에 있어 확연한 조성변화를 보여준다. 그러나 화분을 이용한 분석은 토탄층이나 유기질 퇴적물이라는 한정된 토양에서만 분석이 가능하며, 조성변화에 있어서 역시 기후와 인간활동의 영향 모두를 반영하기 때문에 이를 구분해 주는 명확한 기준이 필요하다. 따라서 본 연구에서는 이러한 다양한 대리자료 중 고고학 유적지에 적용 가능한 동식물 화석 및 미화석, 지리, 지질학적 자료에 어떠한 것들을 적용할 수 있는지를 살피고, 몇 가지 대리자료를 중심으로 선사인의 농경활동에 대해 살펴보고자 한다.avascular injection of the iodinated contrast materials.석 시기중 성공적인 착상성공율은 56%(71/126)였다..8H2O를 사용함으로써 host-guest적인 반응을 유도시키는데 있어 물의 가장 실용적이고 효과적인 수열용매임도 알았다. ZnSiO4:Mn, CaWO4, MgWO4와 같은 형광체 분말은 공업적으로 고상반응 또는 습식법에 의해 얻어지고 있으나 이들 방법에 있어서는 분쇄공정으로 인한 형광특성의 저하와 같은 문제점이 있다. 따라서 본 연구에서는 수열법을 이용하여 이들