• Title/Summary/Keyword: Degradation agent

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Copper Uptake by Tyromyces palustris (Tyromyces palustris를 이용한 구리의 제거)

  • Son, Dong-Weon;Lee, Dong-Heub;Kang, Chang-Ho
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.1
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    • pp.57-62
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    • 1998
  • In this research, the removal or uptake of heavy metals such as coppers by using oxalic acid metabolism of wood rot fungi, Tyromyces palustris were endeavored. As results, the addition of oxalic acid to copper containing culture did not cause the mycelium growth, but Tyromyces palustris was able to grow in this culture without inhibition. Tyromyces palustris grew with the cicular halo type in copper containing culture, and this type was formed as collectives after examining by microscope, and considered as copper oxalates by analyzing FT-IR comparison experiment with standards. According to this result, Tyromyces palustris has secreted oxalic acid during incubation, this secreted oxalic acid was combined with coppers, and formed copper oxalates by chelating reactions. In other words, the oxalic acid was might be as non-toxifying agent of coppers in medium. By using this copper removal mechanisms, Tyromyces palustris immobilized sawdust was used in bench scale air lift system for removing coppers. The added coppers were almost removed from the system within 72hrs. Therefore, this nonenzymatic wood degradation mechanism may give a possibility for removing coppers from copper containing waste water.

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A Novel Maltopentaose-Producing Amylase as a Bread Antistaling Agent

  • Auh, Joong-Hyuck;Lee, Su-Yong;Yoo, Seung-Seok;Son, Hyun-Ju;Lee, Jae-Woo;Lee, Sung-Joon;Kim, Young-Bae;Park, Kwan-Hwa
    • Food Science and Biotechnology
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    • v.14 no.5
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    • pp.681-684
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    • 2005
  • A maltopentaose-producing amylase (G5-amylase) from Bacillus megaterium KSM B-404 was applied to retard bread retrogradation. Retrogradation rates were determined by differential scanning calorimetry. Gel permeation chromatography determined changes in maltooligosaccharide composition and the molecular weight profiles of carbohydrate tractions. The baking process produced maltopentaose and maltotriose by the hydrolysis of starch molecules into small units. Amylose and amylopectin degradation as well as maltooligosaccharides produced by the enzyme were likely responsible for retarding starch retrogradation. Overall, addition of G5-amylase reduced the starch retrogradation rate, and was as effective as Novamyl(R), a commercial enzyme.

Hematopoietic Characteristics of the Ethylacetate Fraction of Panax ginseng and Identification of the Chemical Constituents (인삼의 에칠아세테이트 추출분획의 조혈활성 특성 및 구성 성분 동정)

  • Park, Jong-Dae;Wee, Jae-Joon;Kim, Man-Wook;Lee, Hyong-Joo
    • Applied Biological Chemistry
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    • v.32 no.2
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    • pp.137-142
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    • 1989
  • The ethylacetate soluble fraction of Panax ginseng extract, which has been reported to exhibit hematopoietic effect, was divided into three subfractions, i.e., Fr. I, Fr. II and Fr. III by silica gel column chromatography. The hematopoietic effect of each subfraction was examined in rats treated with anticancer agent, Ara-C($1-{\beta}-D-arabinofuranosylcytosine)$). Among them, Fr. III showed 90% recovery of leucocyte and erythrocyte counts in bonemarrow cell depleted rats, suggesting it to be hematopoietic fraction. From Fr. III, two major compounds were isolated and identified as ginsenoside $Rh_1$ and $Rg_2$ by $^{13}C-NMR$ and degradation method.

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Biological Removal of Nitrogen Oxides from Combustion Flue Gases (연소배가스 중 질소산화물(NOx) 제거를 위한 생물학적 기술)

  • Lee, Ki-Say
    • Applied Chemistry for Engineering
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    • v.21 no.3
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    • pp.243-251
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    • 2010
  • Nitrogen oxides (NOx) in combustion flue gas are currently mitigated by chemical processes such as catalytic reduction, absorption and adsorption. However, development of environmentally sustainable biological processes is necessary in the near future. In this paper, the up-to-dated R&D trend of biological methodologies regarding NOx removal was reviewed, and their advantages and disadvantages were discussed. The principles and applications of bacterial system including nitrification and denitrification and photosynthetic microalgae system were compared. In order to enhance biological treatment rate and performance, the insoluble nitric oxide (NO) should be first absorbed using a proper solubilization agent, and then microbial degradation or fixation is to be followed. The use of microalgal system has a good prospect because it can fix $CO_2$ and NOx simultaneously and requires no additional carbon for energy source.

A Study on Electrostatic Degradation Properties of Silicone Rubber due to Reinforcing Agent (보강제 변화에 따른 실리콘 고무의 정전기 열화 특성에 관한 연구)

  • Lee, Sung Ill
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.2
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    • pp.120-125
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    • 2015
  • In this study, we have come to the following conclusions regarding to the electrification properties (electrostatic electrification voltage and electrification relaxation time) of electrostatics in the three type of specimen (size: $4cm{\times}4cm{\times}0.103cm$) of silicone rubber which is mixed with the ATH (Aluminium Trihydrate(Al($OH_3$)) of 30 phr, 60 phr, 120 phr as reinforcing filler. The electrification properties of electrostatics were measured for the different mixing ratio of ATH with the applied voltage of DC 10 kV at the temperature range of $10^{\circ}C{\sim}30^{\circ}C$ and humidity range of 60%~80%. When the temperature remained constant, the electrical resistance decreased as the humidity increasing in the range of 60%, 70%, 80%. In contrast, when the humidity remained constant, the electrical resistance increased as the temperature increasing in the range of $10^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$. Regarding these results, may be it is because the absorption of O-H molecule appeared in the silicone specimen. It was confirmed that when the temperature remained constant, the electrification relaxation time decreased as the humidity increased. In contrast, when the humidity remained constant, the electrification relaxation time increased as the temperature increased.

The Effects of Platycodi Radix on the Induction of LPS and the Activation of $NF-{\kappa}Bp$, the Lung Disease of White Rats

  • Kim Hyun-Joong;Park Dong-Il;Kim Won-Il
    • The Journal of Korean Medicine
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    • v.26 no.1 s.61
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    • pp.18-25
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    • 2005
  • Objective & Methods: We examined the effects of Platycodi radix on the process of lipopolysaccharide (LPS)-induced nuclear factor $NF-{\kappa}Bp65$ and inhibitory $(I)-{\kappa}B{\alpha}$ alteration in RAW 264.7 cells and acute lung injury in rats. Results: Immunoblot analysis showed that LPS-induced degradation of $I-{\kappa}B{\alpha}$ in RAW 264.7 was inhibited by pretreatment of Platycodi radix. The total cells of bronchoalveolar lavage fluid by LPS challenge markedly decreased in the Platycodi radix pretreatment rats. Platycodi radix pretreatment also caused a decline in neutrophils infiltration into interstitium of the lung. In the alveolar macrophages and neutrophils, decreased $NF-{\kappa}Bp65$ and inducible nitric oxide synthase and increased $I-{\kappa}B{\alpha}$ immunoreaction were detected in Platycodi radix pretreated rats compared with LPS alone treated ones. Conclusion : It may be concluded that Platycodi radix attenuates the development of LPS-induced inflammation by reduction of $NF-{\kappa}Bp65$ activation and neutrophil-mediated acute lung injury. Platycodi radix would be useful as a therapeutic agent for endotoxin-induced lung disease.

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In Vitro Activities of 2,2'-Dipyridyl Against Trichomonas vaginalis, Candida albicans, and Gardnerella vaginalis

  • Ryu, Jae-Sook;Min, Duk-Young;Kim, Myeong-Cheol;Kim, Nam-Sik;Shin, Myeong-Heon
    • Journal of Microbiology and Biotechnology
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    • v.11 no.1
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    • pp.124-130
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    • 2001
  • The in vitro activities of 2,2'-dipyridyl, an iron-chelator, against clinical isolates of Trichomonas vaginalis, Candida albicans, and Gardnerella vaginalis was evaluated and compared with those of four other vaginal suppositories, ornidazole, clotrimazole, povidone-iodine, and $Cenacert^{\circledR}$ (Methylbezethonium Chloride mixed with 9-aminoacrydine undecylenate and hydrochloric acid N-myristyl-3-hydroxy butyl amine). The 2,2'-dipyridyl killed T. vaginalis and G. vaginalis at concentrations of $410\;{\mu}g/ml$ and $205\;{\mu}g/ml$, respectively, however, ths agent was less active against C. albicans (80% of which was inhiited at $410\;{\mu}g/ml$). The inhibition of these three pathogens by 2,2'-dipyridyl was similar to clotrimazole. In addition, the effect of 2,2'-dipyridyl on the ultrastructure of T. vaginalis, C. albicans, an G. vaginalis was examined. Transmission electron microscopy indicated that 2,2'-dipyridyl induced modifications of the cellular contents and cell envolope concumitant with the degradation of the three pathogens. These results suggest that 2,2'-dipyridyl has an inhibitory effect on C. albicans and G. vaginalis, as well as T. vaginalis.

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An Antioxidative and Antiinflammatory Agent for Potential Treatment of Osteoarthritis from Ecklonia cava

  • Shin Hyeon-Cheol;Hwang Hye Jeong;Kang Kee Jung;Lee Bong Ho
    • Archives of Pharmacal Research
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    • v.29 no.2
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    • pp.165-171
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    • 2006
  • Osteoarthritis is thought to be induced by the ageing-related loss of homeostatic balance between degeneration and repair mechanism around cartilage tissue in which inflammatory mediators such as reactive oxygen species, cytokines and prostaglandins are prone to overproduction under undesirable physiological conditions. Phlorotannins are unique polyphenolic compounds bearing dibenzo-1,4-dioxin skeleton which are not found in terrestrial plants but found only in some brown algal species such as Ecklonia and Eisenia families. Phlorotanninrich extracts of Ecklonia cava including LAD103 showed significant antioxidant activities such as DPPH radical scavenging, ferric ion reduction, peroxynitrite scavenging, and inhibition of LDL oxidation, indicating their possible antioxidative interference both in onset and downstream consequences of osteoarthritis. LAD103 also showed significant down regulation of $PGE_2$ generation in LPS-treated RAW 246.7 cells, and significant inhibition of human recombinant interleukin-$1{\alpha}$-induced proteoglycan degradation, indicating its beneficial involvement in pathophysiological consequences of osteoarthritis, the mechanism of which needs further investigation. Since LAD103 showed strong therapeutic potentials in arthritic treatment through several in vitro experiments, it is highly encouraged to perform further mechanistic and efficacy studies.

Thermal Curing and Electrical Properties of Epoxy/Graphite/Expanded Graphite Composite for Bipolar Plate of Pemfc (PEMFC 바이폴라 플레이트 제조용 EPOXY/GRAPHITE/EXPANDED GRAPHITE 복합재료의 열경화 및 전기적 성질)

  • Lee, Jae-Young;Lee, Hong-Ki
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.6
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    • pp.827-834
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    • 2011
  • Epoxy/graphite/expanded graphite composites have been prepared in various weight ratios and thermal degradation and electrical properties were estimated in order to use for the bipolar plate materials in PEMFC. Thermogravimetric analysis (TGA) showed that the epoxy/graphite system cured by a curing agent GX-533 was most proper because its weight loss until $80^{\circ}C$ at which PEMFC would be operated was 0.3 wt%, and differential scanning calorimetry (DSC) analysis showed its cure temperature would be sufficient at $80^{\circ}C$. The activation energy for the cure reaction was 132.0 kJ/mol and the pre-exponential factor was $1.76{\times}10^{17}min^{-1}$. Electrical conductivity on the surface of the bipolar plate prepared under a pressure of 200 $kgf/cm^2$ was increased from 4 to 25 $S/cm^2$ by increasing expanded graphite (EG) content from 50 phr to 90 phr. The percolation threshold was initiated around 75 phr and the corrosion rate at 80 phr was 1.903 $uA/cm^2$.

Seahorse-derived peptide suppresses invasive migration of HT1080 fibrosarcoma cells by competing with intracellular α-enolase for plasminogen binding and inhibiting uPA-mediated activation of plasminogen

  • Kim, Yong-Tae;Kim, Se-Kwon;Jeon, You-Jin;Park, Sun Joo
    • BMB Reports
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    • v.47 no.12
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    • pp.691-696
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    • 2014
  • ${\alpha}$-Enolase is a glycolytic enzyme and a surface receptor for plasminogen. ${\alpha}$-Enolase-bound plasminogen promotes tumor cell invasion and cancer metastasis by activating plasmin and consequently degrading the extracellular matrix degradation. Therefore, ${\alpha}$-enolase and plasminogen are novel targets for cancer therapy. We found that the amino acid sequence of a peptide purified from enzymatic hydrolysates of seahorse has striking similarities to that of ${\alpha}$-enolase. In this study, we report that this peptide competes with cellular ${\alpha}$-enolase for plasminogen binding and suppresses urokinase plasminogen activator (uPA)-mediated activation of plasminogen, which results in decreased invasive migration of HT1080 fibrosarcoma cells. In addition, the peptide treatment decreased the expression levels of uPA compared to that of untreated controls. These results provide new insight into the mechanism by which the seahorse-derived peptide suppresses invasive properties of human cancer cells. Our findings suggest that this peptide could emerge as a potential therapeutic agent for cancer.