• Title/Summary/Keyword: Oxidation factor

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The Effects of Physicochemical Factors and Cell Density on Nitrite Transformation in a Lipid-Rich Chlorella

  • Liang, Fang;Du, Kui;Wen, Xiaobin;Luo, Liming;Geng, Yahong;Li, Yeguang
    • Journal of Microbiology and Biotechnology
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    • v.25 no.12
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    • pp.2116-2124
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    • 2015
  • To understand the effects of physicochemical factors on nitrite transformation by microalgae, a lipid-rich Chlorella with high nitrite tolerance was cultured with 8 mmol/l sodium nitrite as sole nitrogen source under different conditions. The results showed that nitrite transformation was mainly dependent on the metabolic activities of algal cells rather than oxidation of nitrite by dissolved oxygen. Light intensity, temperature, pH, NaHCO3 concentrations, and initial cell densities had significant effects on the rate of nitrite transformation. Single-factor experiments revealed that the optimum conditions for nitrite transformation were light intensity: 300 μmol/m2/s; temperature: 30℃ pH: 7-8; NaHCO3 concentration: 2.0 g/l; and initial cell density: 0.15 g/l; and the highest nitrite transformation rate of 1.36 mmol/l/d was achieved. There was a positive correlation between nitrite transformation rate and the growth of Chlorella. The relationship between nitrite transformation rate (mg/l/d) and biomass productivity (g/l/d) could be described by the regression equation y = 61.3x (R2 = 0.9665), meaning that 61.3 mg N element was assimilated by 1.0 g dry biomass on average, which indicated that the nitrite transformation is a process of consuming nitrite as nitrogen source by Chlorella. The results demonstrated that the Chlorella suspension was able to assimilate nitrite efficiently, which implied the feasibility of using flue gas for mass production of Chlorella without preliminary removal of NOX.

Anti-oxidative properties of ginseng (인삼의 항산화 작용)

  • Kim, Eun-Hye;Rhee, Dong-Kwon
    • Journal of Ginseng Research
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    • v.33 no.1
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    • pp.1-7
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    • 2009
  • Clinical and animal studies have shown that free radical overload is an important cause for a variety of diseases. Although ginseng has been recognized as antioxidant, how it modulates anti-oxidative process at the molecular level remains unknown. Free radical production is induced by tumor necrosis factor-$\alpha$ (TNF-$\alpha$) under the stress condition, and (TNF-$\alpha$) release is activated by TNF-$\alpha$-converting enzyme (TACE). Since TACE inhibitor is also well known for anti-inflammatory agent, ginseng seems to show anti-oxidative activity by repressing TACE pathway. Further studies on signal transduction would be warranted to elucidate molecular action mechanisms of ginseng on anti-oxidation and anti-inflammation.

Inorganic Printable Materials for Printed Electronics: TFT and Photovoltaic Application

  • Jeong, Seon-Ho;Lee, Byeong-Seok;Lee, Ji-Yun;Seo, Yeong-Hui;Kim, Ye-Na;More, Priyesh V.;Lee, Jae-Su;Jo, Ye-Jin;Choe, Yeong-Min;Ryu, Byeong-Hwan
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.1.1-1.1
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    • 2011
  • Printed electronics based on the direct writing of solution processable functional materials have been of paramount interest and importance. In this talk, the synthesis of printable inorganic functional materials (conductors and semiconductors) for thin-film transistors (TFTs) and photovoltaic devices, device fabrication based on a printing technique, and specific characteristics of devices are presented. For printable conductor materials, Ag ink is designed to achieve the long-term dispersion stability and good adhesion property on a glass substrate, and Cu ink is sophisticatedly formulated to endow the oxidation stability in air and even aqueous solvent system. The both inks were successfully printed onto either polymer or glass substrate, exhibiting the superior conductivity comparable to that of bulk one. In addition, the organic thin-film transistor based on the printed metal source/drain electrode exhibits the electrical performance comparable to that of a transistor based on a vacuum deposited Au electrode. For printable amorphous oxide semiconductors (AOSs), I introduce the noble ways to resolve the critical problems, a high processing temperature above $400^{\circ}C$ and low mobility of AOSs annealed at a low temperature below $400^{\circ}C$. The dependency of TFT performances on the chemical structure of AOSs is compared and contrasted to clarify which factor should be considered to realize the low temperature annealed, high performance AOSs. For photovoltaic application, CI(G)S nanoparticle ink for solution processable high performance solar cells is presented. By overcoming the critical drawbacks of conventional solution processed CI(G)S absorber layers, the device quality dense CI(G)S layer is obtained, affording 7.3% efficiency CI(G)S photovoltaic device.

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Effects of Daegangwhal-Tang Hot Aqueous Extract on Anti-inflammation and Anti-oxidation in RAW 264.7 Macrophage

  • Lee, Jae Sung;Jo, Na Young;Roh, Jeong Du;Lee, Cham Kyul;Lee, Eun Yong
    • Journal of Acupuncture Research
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    • v.35 no.3
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    • pp.115-119
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    • 2018
  • Background: The objective of this study was to determine the effects of Daegangwhal-Tang (DGHT) hot aqueous extract on production of inflammatory mediators and antioxidants in RAW 264.7 macrophage. Methods: DGHT was extracted with water, filtered, concentrated and freeze-dried to perform. Cytotoxicity of DGHT extract was performed by MTT assay. Activated macrophages were treated with varying concentrations of DGHT extract (10, 50, 100 and $200{\mu}g/mL$), and nitric oxide (NO) and prostaglandin E2 ($PGE_2$) concentrations were measured to detect anti-oxidative effects. Interleukin-6 (IL-6), interleukin-1 beta ($IL-1{\beta}$) and tumor necrosis factor-alpha($TNF-{\alpha}$) concentrations were also measured to detect inflammatory responses to DGHT Results: Cytotoxicity of DGHT extract at concentrations of 10, 50, 100 and $200{\mu}g/mL$ were not observed. NO production was significantly decreased in the DGHT hot aqueous extract $200{\mu}g/mL$ concentration group. $PGE_2$, IL-6, $IL-1{\beta}$ and $TNF-{\alpha}$ production was significantly decreased in the DGHT hot aqueous extract 100 and $200{\mu}g/mL$ concentration groups. DGHT hot aqueous extract appeared to have DPPH free radical scavenging capability at all of concentrations, but did not exceed 50%. Conclusion: These results suggest that DGHT hot aqueous extract has concentration-dependent anti-inflammatory and anti-oxidative effect.

Study on Antioxidant and Anti-inflammatory Effects of Components of Mahwangbujaseshin-tang (마황부자세신탕(麻黃附子細辛湯)의 각 구성약물별 항산화 및 항염 효능에 관한 연구)

  • Choi, Chul-Woo;Oh, Min-Seok
    • Journal of Korean Medicine Rehabilitation
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    • v.24 no.4
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    • pp.15-28
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    • 2014
  • Objectives This study was carried out to find out the Antioxidant and Anti-inflammatory Effects of Components of Mahwangbujaseshin-tang in LPS-Stimulated RAW264.7 Macrophages. Methods There are 5 experimental groups. ; normal, control, EH (Ephedrae Herba), ALRP (Aconiti Lateralis Radix Preparata) and AR (Asiasari Radix). The extract of EH, ALRP and AR ($100{\mu}g/ml$) was added to each group. We examined cytotoxicity, total phenolic contents, DPPH and ABTS free radical scavenging activity, Intracellular ROS (reactive oxygen species) production, NO (Total Nitric oxide), iNOS (inducible nitric oxide synthase), PGE2 (prostaglandin E2), COX-2 (cyclooxygenase-2), $IL-1{\beta}$ ($interleukin-1{\beta}$), IL-6 (interleukin-6), $TNF-{\alpha}$ (tumor necrosis factor-${\alpha}$), MMP-9 (matrix metalloproteinase-9), TIMP-1 (tissue inhibitor of metalloproteinase-1) and HO-1 (heme oxygenase-1) expression level. Results 1. Total phenolic contents of EH were in the highest level. 2. DPPH and ABTS free radical scavenging activity of EH was in the highest level. 3. ROS production was significantly decreased in AR. 4. NO production was significantly decreased in EH, ALRP, AR and iNOS expression was decreased in EH, AR. 5. PGE2 and COX-2 expression was decreased in EH, AR. 6. $IL-1{\beta}$ production was significantly decreased in EH, AR and IL-6 production was significantly decreased in AR. $TNF-{\alpha}$ production was significantly decreased in ALRP, AR. 7. MMP-9 and TIMP-1 production were significantly decreased in EH. 8. HO-1 expression was significantly increased in EH. 9. With simultaneous usage of SnPP which is expression inhibitor of HO-1, NO, $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ production were partially increased in EH, ALRP, AR. Conclusions According to this study, Components of Mahwangbujaseshin-tang have anti-oxidants and anti-inflammation effects in LPS-Stimulated RAW264.7 Macrophages.

A new biomarker for the early diagnosis of ovarian torsion: SCUBE-1

  • Uyanikoglu, Hacer;Hilali, Nese Gul;Yardimciel, Mesut;Koyuncu, Ismail
    • Clinical and Experimental Reproductive Medicine
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    • v.45 no.2
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    • pp.94-99
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    • 2018
  • Objective: Prompt diagnosis and management are essential for saving the adnexal organs from infarction in cases of ovarian torsion (OT). This study aimed to determine the diagnostic significance of signal peptide, complement C1r/C1s, Uegf, and Bmp1 (CUB), and epidermal growth factor-like domain-containing protein-1 (SCUBE-1) levels in cases of OT, an emergent ischemic condition, and the relationship of SCUBE-1 with oxidative stress parameters. Methods: This prospective study was conducted among 15 OT patients and 20 age- and gravidity-matched healthy women. SCUBE-1 serum concentrations were determined by using enzyme-linked immunosorbent assays. In addition, oxidative stress was evaluated by measuring the serum levels of advanced oxidation protein products (AOPP), ferric reducing ability of plasma (FRAP), and glutathione (GSH). Results: The SCUBE-1 titers were significantly higher in the patients with OT than in the controls (p=0.008). In addition, serum FRAP and GSH levels were significantly lower in the OT patients than in the controls (p<0.001 for both). Serum AOPP levels were higher in the OT patients, but this trend was not statistically significant (p>0.05). Furthermore, there were no correlations between SCUBE-1 levels and age, gravidity, parity, cyst size, and AOPP, FRAP, or GSH levels (p>0.05). Conclusion: We believe that SCUBE-1 may be a promising biomarker for the early diagnosis of OT.

Optimum Conditions for Removal of Hydrogen Sulfide Using Fe-EDTA Complex (Fe-EDTA 착물을 이용한 황화수소 제거의 최적 반응 조건)

  • Jin, Sang-Gi;Cha, Jin-Myeong;Lee, In-Wha;Yoon, Suk-Jin;Kim, Si-Wouk
    • Applied Chemistry for Engineering
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    • v.7 no.1
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    • pp.177-185
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    • 1996
  • The optimum conditions for the removal of hydrogen sulfide by Fe-EDTA complex in the bubble column reactor were investigated. As the concentrations of the complex increased, the conversion rate of hydrogen sulfide increased, while Fe concentration and pH were stably decreased and the amount of elemental sulfur produced was also increased. Hydrogen sulfide was removed efficiently when the concentration of Fe-EDTA complex was maintained more than 0.05M. pH acts as an important factor for the stability of complex in the oxidation of hydrogen sulfide and optimum pH range was 8.5~9.5. As the molar ratio of EDTA : Fe was increased, the conversion rate of hydrogen sulfide became stable. However, the rate was decreased due to the precipitation of FeS when the concentration of EDTA was decreased. As the concentration of EDTA increased, the conversion rate of hydrogen sulfide increased due to the high stability of Fe-EDTA complex.

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Composition of Organic Compounds in the Ambient PM10 of the Anmyon Island (안면도 미세먼지 내 유기성분들의 분포 특성)

  • Lee, Ji Yi;Hwang, Eun Jin;Lim, Hyung Bae;Kim, Yu Won;Kim, Eun Sil;Kim, Yong Pyo
    • Particle and aerosol research
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    • v.9 no.3
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    • pp.187-197
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    • 2013
  • To understand the characteristics of organic aerosol(OA) at the background atmosphere of Korea, an observation of atmospheric PM10 was conducted at a Global Atmospheric Watch(GAW) station operated by the Korean Meteorological Administration at Anmyon Island during 2010. Various organic compounds were analyzed from 26 samples by using a gas chromatography-mass spectrometer. Water soluble organic carbon(WSOC) was also analyzed by using a total organic carbon(TOC) analyzer. Among 6 classes with 68 target compounds detected, the classes of n-alkanoic and alkenoic acids ($326.67{\pm}75.40ngm^{-3}$) and dicarboxylic acids ($323.74{\pm}361.89ngm^{-3}$) were found to be major compound classes in the atmosphere of Anmyon Island. Compared to the previous results reported for 2005 spring samples at Gosan site, the concentrations of organic compounds at Anmyon Island were 3-10 times higher than Gosan site due to the difference of location and sampling period. The concentrations of organic compounds were varied with the atmospheric conditions. Significant increase of the concentrations of dicarboxylic and carboxylic acids in the smog episode indicated that secondary oxidation of organic compounds was major factor to increase OA concentration during smog episode in the Anmyon Island. It was found that the compositions of the OA measured at Anmyon Island were dependent on the air parcel trajectories.

Synthesis of Solution-Processed Cu2ZnSnSe4 Thin Films on Transparent Conducting Oxide Glass Substrates

  • Ismail, Agus;Cho, Jin Woo;Park, Se Jin;Hwang, Yun Jeong;Min, Byoung Koun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.7
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    • pp.1985-1988
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    • 2014
  • $Cu_2ZnSnSe_4$ (CZTSe) thin films were synthesized on transparent conducting oxide glass substrates via a simple, non-toxic, and low-cost process using a precursor solution paste. A three-step heating process (oxidation, sulfurization, and selenization) was employed to synthesize a CZTSe thin film as an absorber layer for use in thin-film solar cells. In particular, we focused on the effects of sulfurization conditions on CZTSe film formation. We found that sulfurization at $400^{\circ}C$ involves the formation of secondary phases such as $CuSe_2$ and $Cu_2SnSe_3$, but they gradually disappeared when the temperature was increased. The formed CZTSe thin films showed homogenous and good crystallinity with grain sizes of approximately 600 nm. A solar cell device was tentatively fabricated and showed a power conversion efficiency of 2.2% on an active area of 0.44 $cm^2$ with an open circuit voltage of 365 mV, a short current density of 20.6 $mA/cm^2$, and a fill factor of 28.7%.

The etiologic factor of senile cataract and mechanism of occurance of diabetic cataract (노인성 백내장의 원인과 당이 백내장 발생에 미치는 영향에 대한 고찰)

  • Choi, Hae Jung;Chen, Ko Hsien
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.2
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    • pp.1-6
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    • 1996
  • The most common cause of blindness is cataract. The possible causes, radiation, sugar, drugs, trauma, nutrition, congenital, secondary to eye disease etc. Generally, the opacification of the lens are the result fa oxidation of the lens fibers. The basis for lens transparency is the structural integrity of lens fibers. Opacities were occur if there is a significant amount of high molecular weight protein aggregates. If Ca ions combined with lens ${\alpha}$-crystallin proteins, the lens fibers were aggregated by high molecular weight proteins and the lens were opacified. If Ca ions detached from lens ${\alpha}$-crystallin proteins, the lens fibers were aggregated by low molecular weight proteins and the lens were re-cleared. We need to find out the variety of factors can initiated the process of age-related cataract. And to understanding the mechanism how the various kind, of diabetic cataracts occur.

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