• Title/Summary/Keyword: Biological hydrogen

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Synthesis and Biological Evaluation of Allylamine Type Antimycotics

  • Chung, Soon-Young;Chung, Byung-Ho
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.187.3-188
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    • 2003
  • Structure-activity relationship studies of allylamine type of antimycotics were carried out to evaluate the effect of naphthyl and methyl portion of naftifine. Compounds with 4-fluorphenyl, 2-fluorophenyl, 2,4-dichlorophenyl, 2,6-dichlorophenyl, 4-nitrophenyl, and 2,3-dihydro-benzo[l,4]dioxin-6-yl instead of naphthyl group with hydrogen, methyl, and ethyl in the place of methyl in naftifine were synthesized and tested their in vitro anti-fungal activity against five different fungi. Eight compounds showed significant antifungal activity against T. mentagrophytes. (omitted)

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SELENITE SUPPRESSES HYDROGEN PEROXIDE-INDUCED CELL APOPTOSIS THROUGH INHIBITION OF ASK1 AND ACTIVATION OF PI3-K/AKT PATHWAYS

  • Yoon, Sang-Oh;Chung, An-Sik
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.111-111
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    • 2001
  • The relationship between selenium and signal molecules is not well elucidated yet. It was found that physiological concentration of selenite, less than 3 $\mu$M, reduced ASKl activity and induced of PI3-Kinase/Akt pathways in HT1080 cells. Duration of these signal molecules by selenite was much longer than that by growth factors and other stresses. The longer duration time of these signal molecules may be important to maintain normal functions against stresses.(omitted)

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Evaluation of Rapid Immunochromatographic Assay Kit for HBsAg-Screening Using Whole Blood

  • Shin, Hyeong-Soon;Heo, Tae-Ryeon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.5
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    • pp.362-365
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    • 2000
  • A rapid immunochromatographic assay kit using whole blood to screen hepatitis B surface antigen was developed and evaluated by using sera from 240 patients. The reference diagnosis was based on the results obtained with GENEDIA Anti-HBs Rapid kit which is very similar to the above kit except for the use of serum. The test demonstrated a good correlation with the reference immunochromatographic assay kit, that is, the sensitivity and the specificity of the kit was 100%, respectively. The rapid test kit using whole blood should be more convenient and useful for the diagnosis of hepatitis B virus because the kit does not need machines and time to prepare serum. In addition, this kit is safe from inadvertent infection during sample treatment because the blood is sterilized with hydrogen peroxide, eliminates the procedure required to prepare serum and reduces the possibility of exposure to infectious agents.

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Odor Reduction Technology in Sewage Treatment Facility Using Biofilter with Reed Grass(Phragmites australls) (갈대(Phragmites australls)수초를 적용한 바이오필터에서의 하수처리시설 악취저감기술)

  • Chung, Jin-Do;Kim, Kyu-Yeol
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.3
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    • pp.373-382
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    • 2013
  • In this study, a biological odor treatment system was proposed to remove odor(foul smell) materials causing several problems in the closed sewage treatment plant. This odor treatment system was composed of a two-step biofilter system in one reactor. The two-step biofilter reactor was constructed with natural purification layer in upper part and artificial purification layer in lower part. The reed grasses of water purification plants were planted in the surface area and mixed porous ceramic media were filled with the lower part of biofilter reactor. By using the above experimental apparatus, the ammonia gas removal efficiency was attained to 98.3 % and the hydrogen sulfide gas removal efficiency was appeared more than 97.7 % which shows more effective than the conventional odor removal process.

Effects of Specific Interaction Altering Reagents on Hardnesses of Succinylated Soy Protein Gel

  • Bae, Dongho;Jung, Hosun;Choi, Yong-Hee
    • Journal of Applied Biological Chemistry
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    • v.42 no.3
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    • pp.125-129
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    • 1999
  • The changes in gel characteristics of soy protein and succinylated soy protein due to various specific interaction-altering reagents which affect the formation and textural properties of gels, were studied. The reagents were added to 15% soy protein solutions prior to heat treatment. Succinylated soy protein formed harder gel without the addition of reagents. Hardly no gels were formed with urea, indicating that hydrogen bonds significantly contributed to the formation and hardness of the gel and the effects of urea on the hardness of succinylated soy protein gel were more significant. Disulfide bonds were important in the formation of hard gels whether they were succinylated or not, but the contributions of hydrophobic interactions to gel hardness were relatively insignificant. The hardness reducing effects of NaCl and NaSCN were more significant in succinylated soy protein gel. As such, electrostatic interactions were important for succinylated soy protein to form hard gel but not for unmodified soy protein.

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Downregulation of fungal cytochrome c peroxidase expression by antifungal quinonemethide triterpenoids

  • Seo, Woo-Duck;Lee, Dong-Yeol;Park, Ki Hun;Kim, Jin-Hyo
    • Journal of Applied Biological Chemistry
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    • v.59 no.4
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    • pp.281-284
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    • 2016
  • To handle the development of antifungal drug resistance, the development of new structural modules and new modes of action for antifungals have been highlighted recently. Here, the antifungal activity of quinonemethidal triterpenoids such as celastrol, dihydrocelastrol, iguestein, pristimerin, and tingenone isolated from Tripterygium regelii were identified (MIC $0.269-19.0{\mu}M$). C. glabrata was the most susceptible to quinonemethide among the tested fungi. Furthermore, quinonemethide suppressed cyctochrome c peroxidase expression dramatically, decreasing fungal viability caused by the accumulation of hydrogen peroxide. Thus, cyctochrome c peroxidase downregulation of quinonemethide may be a key mode of action for antifungals.

Investigation of Temperature Effect on Electrode Reactions of Molten Carbonate Electrolysis Cells and Fuel Cells using Reactant Gas Addition Method

  • Samuel Koomson;Choong-Gon Lee
    • Korean Chemical Engineering Research
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    • v.62 no.3
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    • pp.253-261
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    • 2024
  • The impact of temperature on electrode reactions in 100 cm2 molten carbonate cells operating as Fuel Cells (FC) and Electrolysis Cells (EC) was examined using the Reactant Gas Addition (RA) method across a temperature range of 823 to 973 K. The RA findings revealed that introduction of H2 and CO2, reduced the overpotential at Hydrogen Electrode (HE) in both the modes. However, no explicit temperature dependencies were observed. Conversely, adding O2 and CO2 to the Oxygen Electrode (OE) displayed considerable temperature dependencies in FC mode which can be attributed to increased gas solubility due to the electrolyte melting at higher temperatures. In EC mode, there was no observed temperature dependence for overpotential. Furthermore, the addition of O2 led to a decrease in overpotential, while CO2 addition resulted in an increased overpotential, primarily due to changes in the concentration of O2 species.

Two-Stage Biological Hydrogen Production by Rhodopseudomonas palustris P4 (Rhodopseudomonas palustris P4에 의한 이 단계(Two-stage) 생물학적 수소생산)

  • Yun, Young-Su;In, Sun-Kyoung;Baek, Jin-Sook;Park, Sung-Hoon;Oh, You-Kwan;Kim, Mi-Sun
    • Journal of Hydrogen and New Energy
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    • v.16 no.4
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    • pp.315-323
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    • 2005
  • The integrated or the two-stage (dark anaerobic and photosynthetic) fermentation processes were compared for the hydrogen production using purple non-sulfur photosynthetic bacteria, Rhodopseudomonas palustris P4. Cell growth, pH changes and organic acids and bacteriochlorophyll contents were monitored during the processes. Culture broth of Rps. palustris P4 exhibited dark-red during the photosynthetic culture condition, while yellow under the anaerobic condition without light. Rps. palustris P4 grown at the photosynthetic condition evolved 0.38 and 1.33 ml $H_2$/mg-dcw during the dark and the light fermentation, respectively, which were totally 1.71 ml $H_2$/mg-dcw at the two-stage fermentation. The rate of hydrogen production using Rps. palustris P4 grown under the dark anaerobic condition was 2.76 ml $H_2$/mg-dcw which consisted of 0.46 and 2.30 ml $H_2$/mg-dcw from the dark and the photosynthetic fermentation processes, respectively. Rps. palustris P4 grown under dark anaerobic conditions produced $H_2$ 1.6 times higher than that of grown under the photosynthetic condition. However, total fermentation period of the former was 1.5 times slower than that of the latter, because the induced time of hydrogen production during the photosynthetic fermentation was 96 and 24 hours when the seed culture was the dark anaerobic and photosynthetic, respectively. The integrated fermentation process by Rps. palustris P4 produced 0.52 ml $H_2$/mg-dcw(1.01 mol $H_2$/mol glucose), which was 20% of the two-stage fermentation.

Integrated Wet Oxidation and Aerobic Biological Treatment of the Wastewater Containing High Concentration of Phenol (고농도 페놀 폐수의 습식산화와 호기성 생물학적 통합처리)

  • Choi, Ho-Jun;Lee, Seung-Ho;Yu, Yong-Ho;Yoon, Wang-Lai;Suh, II-Soon
    • KSBB Journal
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    • v.22 no.4
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    • pp.244-248
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    • 2007
  • The treatment of a model wastewater containing high concentration, 10 $g/{\ell}$, of phenol in an integrated wet oxidation-aerobic biological treatment was investigated. Partial wet oxidation under mild operating conditions was capable of converting the original phenol to biodegradable organic acids such as maleic acid, formic acid and acetic acid, the solution of which was subjected to the subsequent aerobic biological treatment. The wet oxidation was carried out at 150$^{\circ}C$ and 200$^{\circ}C$ and the initial pH of 1 to 12. The high temperature of 200$^{\circ}C$ and the acidic initial condition in the wet oxidation led to effluents of which biodegradability was higher in the subsequent biological oxidation process, as assessed by chemical oxygen demand (COD) removal. Homogeneous catalyst of $CuSO_4$ was also used for increasing the oxidation rate in the wet oxidation at 150$^{\circ}C$ and initial pH of 3.0. However, the pretreatment with the catalytic wet oxidation resulted in effluents which were less biodegradable in the aerobic biological process compared to those out of the non-catalytic wet oxidation at the same operating conditions.

Antioxidant, Cytotoxicity and Cytoprotective Potential of Extracts of Grewia Flava and Grewia Bicolor Berries

  • Masisi, Kabo;Masamba, Riach;Lashani, Keletso;Li, Chunyang;Kwape, Tebogo E.;Gaobotse, Goabaone
    • Journal of Pharmacopuncture
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    • v.24 no.1
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    • pp.24-31
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    • 2021
  • Objectives: Accumulation of cellular reactive oxygen species (ROS) leads to oxidative stress. Increased production of ROS, such as superoxide anion, or a deficiency in their clearance by antioxidant defences, mediates cellular pathology. Grewia Spp fruits are a source of bioactive compounds and have notable antioxidant activity. Although the antioxidant capacity of Grewia Spp has been studied, there is very limited evidence that links the antioxidant activities of Grewia bicolor and Grewia flava to the inhibition of free radical formation associated with damage in biological systems. Methods: This study evaluated the protective effects of Grewia bicolor and Grewia flava extracts against free radical-induced oxidative stress and the resulting cytotoxicity effect using HeLa cells. Antioxidant properties determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic content (TPC) assays showed significantly higher (p < 0.05) antioxidant activity in Grewia flava (ethanol extract) than Grewia flava (water extract) and Grewia bicolor (ethanol and water extracts). Results: Using 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide or MTT assay, cytotoxicity results showed that extracts of Grewia bicolor and Grewia flava were less toxic to HeLa cells at tested concentrations compared to the untreated control. This confirmed the low toxicity of these edible fruits at the tested concentrations in HeLa cells. Furthermore, hydrogen peroxide (H2O2)-induced cell loss was effectively reduced by pre-incubating HeLa cells with Grewia bicolor and Grewia flava extracts, with Grewia flava (ethanol extract) revealing better protection. Conclusion: The effect was speculated to be associated with the higher antioxidant activity of Grewia flava (ethanol extract). Additional studies will warrant confirmation of the mechanism of action of such effects.