• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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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.

• Korean Journal Plant Pathology
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• v.14 no.2
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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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• 2007.06a
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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.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.3
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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.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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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.

• The Korean Journal of Cytopathology
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• v.18 no.2
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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.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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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.

• Herbal Formula Science
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• v.12 no.2
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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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.3
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• pp.297-302
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• 2006

We investigated gonadal development and sex ratio of artificial seedlings of the oblong rockfish Sebastes oblongus, based on samplings for 370 days just after parturition. The primordial germ cells and genital ridge appeared separately under the mesentery in the yolk-sac stage larva (total length: 7.10-7.77 mm) just after parturition. The primordial germ cells and genital ridge integrated to form primordial gonad in 5-day-old larvae (7.12-9.68 mm), and then proliferation of somatic cell and germ cell occurred in the gonad, which was maintained undifferentiated until 45-days after parturition (18.6-20.4 mm). The ovarian differentiation began in the larva of 50-days old (dab) after parturition (dap) (20.0-24.5 mm). The somatic tissues elongated from the both opposite end-sites of undifferentiated gonad were consequently fused and formed a complete ovarian cavity at 60-days old dap (25.5-32.0 mm). In 80-days old dap (37.3-47.2 mm), meiosis of oogonia occurred to be chromatin nucleolus stage oocyte. The perinucleolus stage oocytes appeared at in 130-days old dap (68.0-86.0 mm), and previtellogenic stage oocytes appeared in 370-days old dap (101.0-116.0 mm). Only female was observed in the artificially produced oblong rockfish in the present study. This result revealed the effect of higher temperature on the sex determination of the oblong rockfish..

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.50-58
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• 1995

These studies were carried out to develop a system for non -destructive and continuous measurement of fresh weight and to analyse the growth response of leaf lettuce under the different nutrient solution and light condition with this system. The developed measurement system was consisted of four load cells and a microcomputer. The output from the system was highly positive correlation with the plant fresh weight above the surface of the hydroponic solution. The top fresh weight of plant could be measured within the error $\pm$ 1.0g in the range of 0 - 2000g. The top fresh weight of leaf lettuce increased 44 times at 18th day after transferring to the nutrient solution, and the maximum growth rate was observed at 13th day after transferring. The growth rate was 10.7- 29.6% per day during 18 days. Optimum concentration of the nutrient solution for the growth of lettuce was 1.4 - 2.2 mS/cm of EC level. When the light condition was changed from dark to light, the fresh weight was temporarily decreased, but the fresh weight increased under the opposite condition. Top fresh weight of leaf lettuce in the darkness normally increased within 12 hours after darkness treatment, and then slowly increased until 78 hours under continuous dark condition. After that times, the fresh weight began to decrease.