• Title/Summary/Keyword: methanol activation

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Continuous methanol synthesis directly from methane and steam over Cu(II)-exchanged mordenite

  • Lee, Sae Ha;Kang, Jong Kyu;Park, Eun Duck
    • Korean Journal of Chemical Engineering
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    • v.35 no.11
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    • pp.2145-2149
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    • 2018
  • The formation of methanol directly from methane and steam was observed over Cu ion-exchanged mordenite. Furthermore, the continuous production of methanol was achieved by co-feeding methane and steam over Cumordenite. The methanol production rate was comparable to that reported in the stepwise process in which activation, methane reaction, and extraction of methanol were carried out separately.

Suppressive Effect of Chlorella Methanol Extract on Oxidative Stress and NFkB Activation in RAW 264.7 Macrophages

  • Park, Ji-Young;Lee, Hyo-Sun;Song, Young-Sun
    • Preventive Nutrition and Food Science
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    • v.8 no.2
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    • pp.124-129
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    • 2003
  • This study was designed to investigate whether a methanol extract of chlorella can suppress oxidative stress and nuclear factor kB (NFkB) activation in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophage cells. Treatment of RAW 264.7 cells with chlorella methanol extract (25, 50, and 100 $\mu$g/mL) significantly reduced LPS-stimulated nitric oxide production in a dose-dependent manner. Treatments with chlorella methanol extract at all concentrations also reduced thiobarbituric acid-reactive substances accumulation and enhanced glutathione level at 50 and 100 $\mu$g/mL levels. The specific DNA binding activities of NFkB on nuclear extracts in cells treated with 50 $\mu$g/mL and 100 $\mu$g/mL chlorella methanol extracts were significantly suppressed. These results suggest that chlorella methanol extract has mild antioxidative activity and the ability to suppress intracellular oxidative stress and NFkB activation.

Study on Transcriptional Factors Activation Change of HL-60 cell Apoptosis by Hedyotis Diffusa's Methanol Extract (백화사설초 메탄올 추출물에 의한 HL-60 세포고사과정에 있어서의 transcriptional factors 활성변화 연구)

  • Park, Sang-Goo;Lee, Ji-Hyun;Moon, Gu;Moon, Suk-Jae;Won, Jin-Hee;Park, Lae-Gil
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.6 no.1
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    • pp.67-79
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    • 2000
  • Objective : Hedyotis diffusa has been used as an anticancer agent for several decades in oriental medicine. We test whether the methanol extract of the herb affects transcriptional activation factors including $NF-{\kappa}B$ and AP-1. Methods : 1. HL-60 cells were treated with various concentrations(from 200 to $50{\mu}g/ml$) of methanol extract and $H_2O$ extract($200{\mu}g/ml$)of hedyotis diffusa, After 48h later, the cells were tested for viability by MTT assay. 2. The HL-60 cells were treated with $200{\mu}g/ml$ of methanol extract for the indicated periods. First. Nuclear extracts were isolated and incubated with oligonucleotide probe of $NF-{\kappa}B$ and AP-1. Second. Nuclear extracts were isolated and reacted with p50, p65. c-rel pan-Jun, c-Jun, JunB. JunD antibody on ice for 30min. Finally The cell lysates were prepared and analyzed by western blotting using anti-Fas, anti-FasL and anti-p53 antibody. Results : 1. The methanol extract decreases the viability of human lymphoid origin leukemia HL-60 cells in a dose-dependent manner. 2. $NF-{\kappa}B$ is rapidly activated by the addition of the methanol extract, reaches a peak at 30min and gradually returns to resting level. We confirm that $NF-{\kappa}B$ is a heterodimer mainly composed of p65 subunit with c-Rel. 3. Transcriptional activation of AP-1 is detected at 30min and reaches a maximum at 1hr after stimulation of the cells with the methanol extract. AP-1 is mainly composed with Jur-D and partially Jug-B proteins. 4. the methanol extract of Hedyotis diffusa induces the expression of Fas, Fas ligand and p53 proteins of HL-60 cells in a time dependent fashion. Conclusions : These results suggest that the methanol extract of Hedyotis diffusa exerts anticancer effects to induce the death of human leukomic HL-60 cells via activation of trascriptional factors such as $NF-{\kappa}B$ and AP-1, increase in expression of Fas mediated signalling proteins, and induction of tumor suppressor gene. p53.

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Anti-inflammatory effect of SD-01 in RAW 264.7 cells (마우스대식세포주인 RAW 264.7에서 SD-01의 항염증 활성 연구)

  • Park, Sun-Dong
    • The Korea Journal of Herbology
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    • v.25 no.3
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    • pp.19-25
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    • 2010
  • Objective : The aim of this study was to investigate anti-inflammatory activity of SD-01 methanol extract in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Methods : Cytotoxic activity of SD-01 methanol extract on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. The nitric oxide (NO) production was measured by Griess reagent system. And proinflammatory cytokines and $PGE_2$ were measured by ELISA method. The levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), $I{\kappa}$-B-alpha and nuclear NF-${\kappa}$ B p65 expression were detected by western blot. Results : Our results indicated that methanol extract of SD-01 significantly inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-$\alpha$, IL-$1\beta$, IL-6 and MCP-1 production in RAW 264.7 cells. Moreover, methanol extract of SD-01 treatment also blocked LPS-induced NF-kB activation. Conclusion : These findings indicate that methanol extract of SD-01 inhibits the production of pro-inflammatory mediators and cytokines via suppression of NF-${\kappa}$ B activation. Take together, these results indicate that methanol extract of SD-01 has the potential for use as an agent of anti-chronic inflammatory diseases.

The Inhibitory Effect of Fermented Dioscoreae batatas Extract on Lipopolysaccharide-induced Macrophage Activation (LPS로 유도된 대식세포 활성에서 발효 산약 추출물의 억제 효과)

  • Lim, Sung-Won;Lee, Sun-Hee;Hur, Jung-Mu;Lee, Young-Mi;Kim, Dae-Ki
    • YAKHAK HOEJI
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    • v.55 no.5
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    • pp.404-410
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    • 2011
  • This study was to elucidate the anti-inflammatory activities of a methanol extract derived from the fermented bark of Dioscoreae batatas on LPS-induced activation in macrophages. It was fermented with Lactobacillus fermentum and L. plantarum and then analyzed to identify the contents of methanol extract and diosgenin. The fermented product showed 3-fold increase in the extraction yield by methanol, and 1.8-fold increase in diosgenin contents, compared to that from the dried bark of D. batatas. Although the methanol extract from the unfermented D. batatas inhibited lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and TNF-${\alpha}$ in J774 A.1 cells, the methanol extract from the fermented product revealed significantly the enhanced the inhibitory activities on LPS-induced production of NO and TNF-${\alpha}$. Taken together, our results indicate that fermentation of bark of D. batatas elevates the functional activity inhibiting macrophage activation through the increase of the content of anti-inflammatory compounds. Thus, its methanol extract may be useful as a functional material for the therapy of inflammatory diseases.

Effects of Antioxidant and Antimicrobial of Geum japonicum Thunb (뱀무 추출물의 항산화 활성 및 항균 효과)

  • Lee, Jeong-Ho;Lim, Yong-Kwang;Kim, Yun-Gyoung;Lim, Jin-A;Lee, Ki-Nam
    • Journal of Society of Preventive Korean Medicine
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    • v.11 no.1
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    • pp.131-138
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    • 2007
  • Herbal medicine has been traditional used for prevention and treatment of treatment of disease, because herbal medicine has few side effects in the human body. Anti-medicines such as antimicrobial medicine and anti-cancer medicine, which contains herbal medicine, are being studied vigorously by researchers. The effects of Geum Japonicum Thumb are restorative, blood circulation and detoxification. It also treats hematemesis, menstruation and furunculus. The ingredients of Geum Japonicum Thumb include geoside and tannin. The study measured antioxidative activation and antifungal activation by using Geum Japonicum Thumb water and methanol extract. The crude extract, which was used for this study, was Korean herbal medicine and the results are as follows. As Geum Japonicum Thumb extracts get stronger, the antioxidative activation tended to increase. The antioxidative activation hit its peak when the density of methanol extract was 120ug/ml. The experiment showed that a 1.0mm clear zone appeared when the density of the Geum Japonicum Thumb methanol extracts were 1000ug/ml in the Staphylococcus epidermidis and 1.1mm clear zone at Pseudomonas aeruginosa. The results of this study concludes that the antioxidative activation is lubricated in the Geum Japonicum Thumb extracts. In addition, the antifungal activation occurred in the fungus of the Staphylococcus epidermidis and the Pseudomonas aeruginosa.

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Characteristics of the Catalysts Using Activated Carbon Nanofibers with KOH as the Support of Anode Catalyst for Direct Methanol Fuel Cell

  • Jung, Min-Kyung;Kim, Sang-Kyung;Jung, Doo-Hwan;Peck, Dong-Hyun;Shin, Jung-Hee;Shul, Yong-Gun;Yoon, Seong-Ho
    • Carbon letters
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    • v.8 no.1
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    • pp.37-42
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    • 2007
  • Carbon nanofiber (CNF) grown catalytically was chemically activated with KOH to attain structural change of CNF. The structural changes of CNF through KOH activation were investigated by using BET and SEM. From the results of BET, it was found that KOH activation was effective to develop particular sizes of pores on the CNF surface, increasing the surface area of CNF. Activated CNF was applied as an anode catalyst support of fuel cell. The effects of different activation conditions including the activation temperature and the activation time on the specific surface area of the CNF activated with KOH were investigated to obtain appropriate structure as a catalyst support. The 60 wt% Pt-Ru catalyst prepared was observed by using TEM and XRD.

Activation of Carbon Fibers by KOH and Adsorption Characteristics for VOC (탄소섬유의 KOH 활성화와 휘발성 유기화합물(VOC)의 흡착특성)

  • Jang, J.S.;Kim, I.K.;Yim, G.;Cho, S.J.
    • Korean Journal of Materials Research
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    • v.9 no.4
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    • pp.362-367
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    • 1999
  • We intended to make the activated carbon fibers which could separate, remove and recover the volatile organic compounds of benzene, toluene, acetone and methanol. Changing activation temperature and time, large specific surface area and narrow pore distribution could be obtained. The activated carbon fibers have large adsorption capacity and selectivility for those organic compounds. We characterized the adsorption capability of the activated carbon fibers for benzene, toluene, acetone and methanol by BET specific surface area and pore size and micropore volume measurements. In the result of activation, the maximum value of BET specific surface area of the fibers was $1100\m^2$/g at $800^{\circ}C$ for 60 minutes and $K_2$O was reduced actively in this condition. Their average pore size was 5.8~5.9$\AA$. The activated carbon fibers prepared in this work had high adsorption rate to saturation and the selectibility for the above organic compounds. The adsorbed amount of acetone and methanol(diameter of$ 4.3\AA$ and $4.4\AA$ respectively) which are smaller than micropore diameter in size was 43~49%, which was larger value than benzene and toluene(in the same diameter as $5.9\AA$).

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Photodecomposition Mechanism of 2-Methoxy-1,2-diphenyl Diazoethane

  • Seong, Dae Dong;Im, Gwi Taek;Kim, Min Sik;Park, Dong Gyu
    • Bulletin of the Korean Chemical Society
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    • v.16 no.1
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    • pp.47-52
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    • 1995
  • The mechanism of the photodecomposition of 2-methoxy-1,2-diphenyl diazoethane has been investigated in methanol and isoprene using time-resolved laser flash photolysis techniques. The reaction of triplet carbene which is generated from 2-methoxy-1,2-diphenyl diazoethane with methanol is believed to proceed via thermal excitation to the singlet state. The activation energy and enthalpy are consistent with a mechanism involving thermal equilibrium between the triplet and singlet state followed by the reaction of the singlet with methanol to give ether.

Synthesis and Characterization of PtPd and PtRuPd Anode Catalysts for Direct Methanol Fuel Cells

  • Horvath G.;Park K. W.;Sung Y. E.
    • 한국전기화학회:학술대회논문집
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    • 2002.07a
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    • pp.211-218
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    • 2002
  • In this study, Pt/Pd (1.1), PtPd (2:1) and PtPd (3:1) binary catalysts and Pt/Ru/Pd (5:4:1) ternary catalyst were designed. The catalysts were synthesized by impregnation method using $NaBH_4$ as a reducing agent. A good catalyst for methanol oxidation requires low on-set potential, stable durability and low activation energy. In order to investigate the catalytic activity for the methanol oxidation, electrochemical measurements such as cyclic voltammetry and chronoamperometry were peformed in sulfuric acid with/without methanol solution. In order to calculate the activation energy of the reaction, electrochemical measurements were also tested at different temperatures. For investigation of the structural analysis such as particle size and alloying, X-ray diffraction and transmission electron microscopy analysis were used. In order to identify the role of the Pd and to determine the composition of the surface of the Pt/Pd nanoparticles, X-ray photoelectron spectroscopy (XPS) analysis was investigated. The XPS spectra of Pd showed that Pd appears only as a metallic state in the binary catalysts. The chemical states of Pt in PtPd catalysts are both metallic and oxidative. Polarization curves and power density data were obtained by testing the DMFC unit cell performance of PtPd and PtRuPd catalysts. These data showed that Pt/Pd (2:1) and Pt/Ru/Pd (5:4:1) have better performance than Pt and Pt/Ru, respectively.

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