• Title/Summary/Keyword: 환원 효과

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Adenoviral-Mediated Ref-1 Overexpression Potentiates NO Production in Bradykinin-Stimulated Endothelial Cells (Bradykinin으로 자극한 혈관내피세포에서 Ref-1의 세포내 과발현에 의한 NO 생성 증진 효과에 대한 연구)

  • Song, Ju-Dong;Kim, Kang-Mi;Lee, Sang-Kwon;Kim, Jong-Min;Park, Young-Chul
    • Journal of Life Science
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    • v.17 no.7 s.87
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    • pp.905-909
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    • 2007
  • The dual-function protein redox factor-1 (Ref-1) is essential for base excision repair of oxidatively damaged DNA and also governs the activation of many redox-sensitive transcription factors. We examined the role of Ref-1 in regulation of nitric oxide (NO) synthesis employing adenoviral-mediatedoverexpression of Ref-1 in bradykinin-stimulated endothelial cells. Intracellular NO was detected with the NO-sensitive fluorophore DAF-2. Overexpression of Ref-1 potentiates bradykinin-stimulated NO production in endothelial cells. And, cells ifected with AdRef-1 showed higher fluorescence intensity compared with uninfected or AdD1312-infected cells. In parallel with this, over expression of Ref-1 also stimulated endothelial NO synthase (eNOS) enzyme activity, compared with unifected or AdD1312-infected cells, in bradykinin-stimulated cells as well as in unstimulated cells. These results suggest that Ref-1 implicates in endothelium-dependent vasorelaxation resulting from NO production in vascular system.

Radical Scavenging Activities of Phellinus pini (상황버섯(Phellinus pini)의 라디칼 소거작용)

  • Nam, Byung-Hyouk;Jo, Wol-Soon;Cui, Yong;Choi, Yoo-Jin;Lee, Jae-Dong;Jeong, Min-Ho
    • Journal of Life Science
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    • v.20 no.3
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    • pp.326-335
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    • 2010
  • The concentration of phenolics in Phellinus pini (CY001) extracts, expressed as mg of GAEs per g of P. pini fractions, and the EtOAc fraction (436.5 mg GAEs/g) of P. pini had a higher phenolic content than other fractions. Several biochemical assays were used to screen antioxidant properties such as reducing power, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, NBT/XO superoxide system and inhibition of DCF/AAPH peroxyl radicals. Among the six mushroom extracts, the EtOAc fraction from P. pini (CY001) showed the most potent DPPH radical, superoxide radical, and peroxyl radical scavenging activities, with $IC_{50}$ values of $11.49\;{\mu}g/ml$, $8.32\;{\mu}g/ml$, and $1.91\;{\mu}g/ml$, respectively. The EtOAc fraction of P. pini (CY001) significantly inhibited enzymatic lipid peroxidation and effectively attenuated LPS-induced NO production of RAW 264.7 cells without cytotoxicity. We also found that the EtOAc fraction had a significant hepato-protectant effect on tacrine-induced cytotoxicity in HepG2 cells. These findings suggest that P. pini (CY001) may have potential as a natural antioxidant, which contains compound(s) with radical scavenging activity.

Characterization of Endoglucanase (F-I-III) Purified from Trichoderma sp. C-4 (새로운 섬유소분해 균주 Trichoderma sp. C-4에서 분리한 Endoglucanase (F-I-III)에 대한 연구)

  • Sul Ok Ju;Chung Dae Kyun;Han In Seob;Jeong Choon Soo
    • Korean Journal of Microbiology
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    • v.41 no.1
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    • pp.81-86
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    • 2005
  • One of the endoglucanases, F-I-III, was purified from the culture filtrate of T. sp. C-4 through procedures including chromatography on Sephacryl S-200, DEAE-Sepharose A-50, and Chromatofocusing on Mono-P (FPLC). The molecular weight of the enzyme was determined to be about 56,000 Da by SDS-PAGE, and pI of 4.9 by analytical isoelectric focusing. F-I-III showed the highest enzyme activity at $55^{\circ}C$, and the pH optimum of the enzyme was 5.0. There was no loss of activity when the enzyme was incubated at $50^{\circ}C$ for 24 hours. The specific activity of the enzyme F-I-III toward the CMC was 315.4 U/mg. The Km value for $PNPG_2$ of F-I-III was 2.69 mM. N-terminal sequence of F-I-III was analyzed to be QPGTSTPEVHPKKLTTYK. It showed $95\%$ of homology to that of EGI from T. reesei. The presence of some metal ions (1 mM) had only a little effect on CMCase activity. The treatment of the reducing agents resulted in the increase of endoglucanase activity.

The Solubility of Ozone in Deionized Water and its Cleaning Efficiency (초순수내에서의 오존의 용해도와 세정효과)

  • Han, Jeoung-Hoon;Park, Jin-Goo;Kwak, Young-Shin
    • Korean Journal of Materials Research
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    • v.8 no.6
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    • pp.532-537
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    • 1998
  • The purpose of this study was to investigate the behavior of ozone in DI water and the reaction with wafers during the semiconductor wet cleaning process. The solubility of ozone in DI water was not only dependent on the temperature but also directly proportional to the input concentration of ozone. The lower the initial ozone concentration and the temperature, the longer the half-life time of ozone. The reaction order of ozone in DI water was calculated to be around 1.5. The redox potential reached a saturation value in 5min and slightly increased as the input ozone concentrations increased. The completely hydrophilic surface was created in Imin when HF etched silicon wafer was cleaned in ozonized DI water containing higher ozone concentrations than 2ppm. Spectroscopic ellipsometry measurements showed that the chemical oxide formed by ozonized DI water was measured to be thicker than that by piranha solution. The wafers contaminated with a non-ionic surfactant were more effectively cleaned in ozonized DI water than in piranha and ozonized piranha solutions.

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Fundamental Study on a Distillation Separation of a LiCl-KCl Eutectic Salt from Rare Earth Precipitates (희토류 침전물로부터 LiCl-KCl 공융염의 증류 분리에 관한 기초연구)

  • Yang, Hee-Chul;Eun, Hee-Chul;Kim, In-Tae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.8 no.1
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    • pp.65-70
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    • 2010
  • The distillation rate on LiCl-KCl eutectic salt under different vacuums from 0.5-50 mmHg was first investigated by using both a non-isothermal and a isothermal thermogravimetric (TG) analysis. Based on the non-isothermal TG data, distillation rate equations as a function of the temperature could be derived. Calculated flux by these model flux equations was in agreement with the distillation rate obtained from isothermal TG analysis. A distillation rate of $10^{-4}-10^{-5}$ mole $cm^{-2}sec^{-1}$ is obtainable at temperatures less than 1300K and vacuums of 0.5-50 mmHg. About a 99% salt distillation efficiency was obtained after an hour at a temperature above 1150 K under 50 mmHg in a small scale distillation test system. An increase in the vaporizing surface area is relatively effective for removing residual salt in the remaining particles, when compared to that for the vaporizing time. Over 99.95% of total distillation efficiency was obtained for a 1-h distillation operation by increasing the inner surface area from $4.52cm^2$ to $12.56cm^2$.

A Study on Reduction of Nitrogen Oxide (NOx) and Stability of Incineration Facility by the Food Wastewater Incineration (음식물류 폐수 소각처리에 따른 질소산화물 저감 및 소각설비의 안정성 평가에 관한 연구)

  • Hwang, Seung-Min;Chung, Jin-Do;Song, Jang-Heon
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.10
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    • pp.901-908
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    • 2009
  • We examine the processing method of the food wastewater to direct spray at living waste incinerator. The demoscale stoker system is used as a incineration facility. The results show that it brings effect on the reduction of nitrogen oxide ($NO_x$) concentration as well as the ammonia ($NH_3$) amount in SNCR (selective non-catalytic reduction) by the incineration of food wastewater which is containing a plentiful ammoniac nitrogen ($NH_3$-N). Furthermore, the stability of incineration facility and the extension of operation period is actualized as a improvement of clogging phenomenon on outer wall of water pipe as the 870~$950^{\circ}C$ maintain of exit temperature in a second combustor by spray of the food wastewater. The 26 items of air pollution matter of nitrogen oxide ($NO_x$), sulfur oxide ($SO_x$) and dioxin etc. are measured. The results show that it is under the value of allowable exhaust standard.

Physicochemical and Sensory Characteristics of Turnip Pickle Added with Chitosan during Storage (키토산 첨가 순무피클 저장 중 이화학적 . 관능적 특성)

  • 손은정;오상희;허옥순;김미리
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.8
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    • pp.1302-1309
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    • 2003
  • Physicochemical and sensory characteristics of turnip pickles added with chitosan and/or beet water extract were investigated. Turnip root slices (4${\times}$1${\times}$0.5 cm) were salted with NaCl and CaCl$_2$, soaked into pickling solution, and then stored at 2$0^{\circ}C$. Throughout the whole storage periods, pH, acidity, saltiness and soluble solid content of three pickles (C, turnip pickle; CC, turnip pickle+chitosan; CBC, turnip pickle+chitosan+beet water extract) ranged to 3.1 ∼ 3.5, 1.5 ∼ 1.7%, 0.5 ∼ 0.7% and 24.5 ∼ 28.5$^{\circ}$Brix, respectively. There were no significant differences between three pickles in saltiness, anthocyanin and reducing sugar content. However, acidity and hardness of CC and CBC were higher than those of control C throughout the storage time. While Hunter's a value of CBC was higher than those of CC or C. Sensory results showed that the best edible time was the 14th day of storage, and at that time, scores of CC and CBC were higher in over-all preference (7.8 and 8.4) than those of C (6.1), and CC and CBC maintained good sensory qualities until 28th day of storage, compared to C (p<0.05).

Changes in Nutrient Distribution, Cycling, and Availability in Aspen Stands after an Intensive Harvesting (집약적(集約的)인 벌채(伐採)로 인한 미국(美國)사시나무림내 양분(養分)의 분포(分布), 순환 (循環) 및 가용성(可溶性)의 변화(變化))

  • Kim, Dong Yeob
    • Journal of Korean Society of Forest Science
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    • v.85 no.4
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    • pp.656-666
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    • 1996
  • Aspen demand has increased recently in the Great Lakes region in the United States. Since aspen has moved into the region in late 1800's, its growing stock has increased so as to change forestry industry of the Lake States. Intensive timber harvesting and biomass removal may cause nutrient depletion, especially on nutrient-poor sites. Forest nutrients and nutrient cycling were investigated in aspen stands of 7-10, 27-33, and 41-42 year-old growing on sandy soils in Minnesota. Nutrients added to the aspen stands by atmospheric deposition and soil weathering were efficiently absorbed and stored in the tree biomass. Aboveground biomass increased from $24.4t{\cdot}ha^{-1}$ at young stands to $139.2t{\cdot}ha^{-1}$ at mature stands. Nutrients accumulated in the tree biomass showed same magnitude of difference. Nutrients added to the site through atmospheric deposition were in the order of Ca, N, K, Mg, and P. Annual litterfall was greater in older stands. However, the amount of nutrients returned by litterfall was not significantly different among stand ages due to the greater nutrient contents in the litterfall of young stands. Litter decomposition and nutrient release rates were greater at young stands than at older stands. Likewise, nutrient availability was higher in young aspen stands and became lower as the stands grew older. Nutrient leaching loss was minimal at all stand ages. Soil N mineralization was greater at young stands than at older stands. Nutrient cycling process was facilitated in young aspen stands with an increased level of available nutrients, Based on the estimations of nutrient balance and nutrient removal by harvesting, Ca was the most critical element which was likely to be depleted if aspen stands are intensively harvested with short rotations.

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Photoelectrochemical Properties of Gallium Nitride (GaN) Photoelectrode Using Cobalt-phosphate (Co-pi) as Oxygen Evolution Catalyst (산소발생용 Cobalt-phosphate (Co-pi) 촉매를 이용한 Gallium Nitride (GaN) 광전극의 광전기화학적 특성)

  • Seong, Chaewon;Bae, Hyojung;Burungale, Vishal Vilas;Ha, Jun-Seok
    • Journal of the Microelectronics and Packaging Society
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    • v.27 no.2
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    • pp.33-38
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    • 2020
  • In the photoelectrochemical (PEC) water splitting, GaN is one of the most promising photoanode materials due to high stability in electrolytes and adjustable energy band position. However, the application of GaN is limited because of low efficiency. To improve solar to hydrogen conversion efficiency, we introduce a Cobalt Phosphate (Co-pi) catalyst by photo-electrodeposition. The Co-pi deposition GaN were characterized by SEM, EDS, and XPS, respectively, which illustrated that Co-pi was successfully decorated on the surface of GaN. PEC measurement showed that photocurrent density of GaN was 0.5 mA/㎠ and that of Co-pi deposited GaN was 0.75 mA/㎠. Impedance and Mott-Schottky measurements were performed, and as a result of the measurement, polarization resistance (Rp) and increased donor concentration (ND) values decreased from 50.35 Ω to 34.16 Ω were confirmed. As a result of analyzing the surface components before and after the water decomposition, it was confirmed that the Co-pi catalyst is stable because Co-pi remains even after the water decomposition. Through this, it was confirmed that Co-pi is effective as a catalyst for improving GaN efficiency, and when applied as a catalyst to other photoelectrodes, it is considered that the efficiency of the PEC system can be improved.

Electrochemical Characterization of Cobalt Oxide Xerogel Electrode for Supercapacitor (수퍼커패시터용 산화코발트 건조겔전극의 전기화학적 특성)

  • Kim Han-Joo;Shin Dal-Woo;Kim Yong-Chul;Kim Seong-Ho;Park Soo-Gil
    • Journal of the Korean Electrochemical Society
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    • v.3 no.3
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    • pp.146-151
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    • 2000
  • So fine cobalt oxide xerogel powders were prepared by using a unique solution chemistry associated with the sol-gel process. The effect of thermal treatment on the crystalinity, particle structure, and corresponding electrochemical properties of the resulting xerogel remained amorphous as $Co(OH)_2$ up to $160^{\circ}C$ With an increase in the temperature above $200^{\circ}C$, both the surface area and pore volume decreased sharply, because the amorphous $Co(OH)_2$ decomposed to form CoO that was subsequently oxidized to form crystalline Co304. In addition, the changes in the crystallinity, and particle structure all had significant but coupled effects on the electrochemical properties of the xerogels. A maximum capacitance of 192F1g was obtained for an electrode prepared with the $CoO_x$ Xerogel calcined at$150^{\circ}C$, which was consistent with the maxima exhibited in both the surface area and pore volume. This capacitance was attributed solely to a surface redox mechanism.