• Title/Summary/Keyword: iron species

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Initial Bacterial Groups in the Development of Biofilm in Drinking Water (수돗물속 생물막 형성의 초기 세균)

  • Lee, Dong-Geun
    • Journal of Environmental Health Sciences
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    • v.33 no.5
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    • pp.428-433
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    • 2007
  • To clarify the pioneer group in the development of biofilms in high chlorine residual water, a semi-pilot model system was operated and 16S rDNA V3 targeted PCR-DGGE was submitted. Biofilm formation occurred rapidly in the model of a drinking water distribution system. It reached $10^3\;CFU/cm^2$ or more on the surface of stainless steel, PVC, and galvanized iron in chlorinated (1.0 mg/l) water within a week. Within a week, uncultured Proteobacteria- and Bacillales group-like sequences were detected and Sphingomonas-like sequences were identified from all season and all pipe materials tested. Hence Sphingomonas species were regarded as the potential pioneer group in the development of biofilm in drinking water and this results would be useful for the prevention of biofilm formation and safety of drinking tap water.

Determination Of Dissolved Trace Metals In Sea Water By Atomic Absorption Spectrophotometry After Concentration By Fe (III) - APDC Coprecipitation

  • Lee, Dong-Soo;Lee, Soo-Hyung;Kwak, Hi-Sang;Lee, Kwang Woo
    • 한국해양학회지
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    • v.15 no.1
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    • pp.66-70
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    • 1980
  • A method for the determination of dissolved species of Cd, Co, Cu, Ni, Pb and Zn in sea water by flame atomic absorption spectrophotometry (AAS) is described. Prior to analysis by AAS, these elements are concentrated by coprecipitation with iron pyrrolidinedithiocarbamate at pH 3 because of matrix effects and their low concentration levels in sea water. The detection limits are 0.01, 0.04, 0.02, 0.05, 0.08, and 0.03$\mu\textrm{g}$/l, and the relative standard deviations are 1.0, 2.4, 1.3, 2.9, 2.0 and 2.9% for Cd, Co, Cu, Ni, Pb and Zn, respectively. The method is shown to be satisfactory in terms of recovery and precision for the determination of these metals in sea water.

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STUDIES ON THE MUSCLES OF MARINE ANIMALS ( I ) CONTENTS OF INORGANIC SUBSTANCES IN THE MUSCLES OF FISH AND SHELLFISH FROM CHEJU ISLAND (수산동물육에 관한 연구 (I) -제주도산 어패류의 무기성분에 대하여-)

  • HA Bong-Seuk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.7 no.4
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    • pp.229-233
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    • 1974
  • The author studied On the inorganic substances in the muscles of Branchiostegus joponicus japonicus, Chromis notatus, Haliotis gigantea mataka, obtaining the following results ; 1) The results of quantitative analysis are shown in Table 3. 2) It is noticeable that the concentration of Cu, P, Fe, Ca, and Na in the muscles of Branchiostegus joponicus japonicus (demersal fish), Chromis notatus (pelagic fish) and Haliotis gigantea mataka (shell fish) are quite different in the three species.

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The study on the Sea Food Pollution According to Environmental pollution of the Western Coast in Korea(I. Fish) (서해안지역의 환경 오염에 의한 수산식품 오염실태 및 예방에 관한 연구(I. 어류))

  • 김순경;이종화;김애정
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.5
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    • pp.851-859
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    • 1997
  • This study was perfomed to investigate the contamination level of harmful heavy metals and the level of trace elements in 15 kinds of fish collected at the western coast in Korea from July to December in 1996. The levels of total lead, cadmium, mercury, iron, copper and zinc were determined and the results were summarized as follows: The minimum and maximum values(ppm) of fish, mean value bracketed, were ; Pb : 0.02~4.80(2.26), Cd: 0.001~0.54(0.04), Hg: 0.007~1.08(0.52), Fe: 7.76~66.39(25.70), Cu; 0.37~121.6(1.90), Zn:12.01~112.10(54.78). The results show that mean contents of Pb, Cd and Hg in 15 species fish were not yet dangerous levels enough to cause a health problem. But the contents of Pb and Hg tend to increase.

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Cloning, Expression, and Characterization of Superoxide dismutase from Aquifex Pyophilus, a Hyperthermophilic Bacteria

  • Rhim, Jae-Hwan;Yesun Han;Kim, Sung-Hou;Yunje Cho
    • Proceedings of the Korean Biophysical Society Conference
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    • 1996.07a
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    • pp.30-30
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    • 1996
  • A suproxide dismutase gene of Aquifex pyroprolus, a novel marine hypenhermophilic bacterium, was cloned, expressed, and characterized. The SOD of A pyrophilus (ApSOD) is an iron-containing homo-oligomeric protein with a monomeric molecular weight of 24.2 kDa. the amino acid sequence is similar to those of known Mn- and Fe-SODs from thermophilic archaea, and metal binding residues in all SOD sequences from different species are also conserved in A. pyrophilus SOD. (omitted)

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Coupled Turbulent Flow, Heat and Solute Transport in Continuous Casting Processes with EMBR (EMBR을 이용한 연속주조공정에서 난류 유동, 상변화 및 매크로 편석에 대한 연구)

  • Kang, Kwan-Gu;Ryou, Hong-Sun;Hur, Nahm-Keon
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1195-1200
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    • 2004
  • A fully coupled fluid flow, heat, and solute transport model was developed to investigate turbulent flow, solidification, and macrosegregation in a continuous casting process of steel slab with EMBR. Transport equations of mass, momentum, energy, and species for a binary iron-carbon alloy system were solved using a continuum model. The electromagnetic field was described by the Maxwell equations. A finite-volume method was employed to solve the conservation equations associated with appropriate boundary conditions. The effects of intensity of magnetic field and carbon segregation were investigated. The electromagnetic field reduces the velocity of molten flow in the mold and an increase in the percentage of C in steel results in a decrease of carbon segregation ratio.

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Studies of the Pyrrhotite Depression Mechanism with Diethylenetriamine

  • 김동수
    • Bulletin of the Korean Chemical Society
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    • v.19 no.8
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    • pp.840-846
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    • 1998
  • The mechanism by which pyrrhotite is depressed by diethylenetriamine (DETA) during pentlandite flotation has been studied. Amyl xanthate is observed to adsorb on pyrrhotite to form both dixanthogen and iron xanthate. In the presence of DETA, the amount of xanthate adsorbed on pyrrhotite is substantially reduced as evidenced by infrared and UV/Vis spectroscopy. However, DETA does not adsorb on pyrrhotite as evidenced by infrared and X-ray photoelectron spectroscopy. DETA shifts the potential of the onset of xanthate adsorption on pyrrhotite by approximately 200 mV toward anodic direction, which is thought to be due to the increased solubility of surface oxidized species on pyrrhotite in the presence of DETA. A window of selectivity for the separation of pentlandite and pyrrhotite is provided by the results obtained in this study.

Oxidative stress and endometriosis

  • Cho, Yeon Jean;Kim, Heung Yeol
    • Kosin Medical Journal
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    • v.33 no.2
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    • pp.135-140
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    • 2018
  • Endometriosis is an estrogen-dependent chronic inflammatory condition that affects women in their reproductive period and is associated with pelvic pain and infertility. Oxidative stress (OS) occurs when reactive oxygen stress (ROS) and anti-oxidants are in imbalance. OS is a potential factor involved in the pathophysiology of endometriosis. Iron-induced ROS may trigger a chain of events resulting in the development and progression of endometriosis. Endogenous ROS are correlated with increased cellular proliferation and ERK1/2 activation in human endometriotic cells. An oxidative environment leads to stimulation of the ERK and PI3K/AKT/mTOR signaling pathways that facilitate endometriotic lesion progression through adhesion, angiogenesis, and proliferation. OS is also known to be involved in epigenetic mechanisms in endometriosis. We summarize the recent knowledge in our understanding of the role of oxidative stress in the pathogenesis of endometriosis.

Investigation of Corrosion Minerals from the Remediation for TCE-Contaminate d Groundwater (TCE로 오염된 지하수 정화시 부식 광물에 대한 연구)

  • Moon, Ji-Won;Moon, Hi-Soo;Yungoo Song;Kang, Jin-Kyoo;Yul Roh
    • Journal of the Mineralogical Society of Korea
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    • v.16 no.1
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    • pp.107-123
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    • 2003
  • The objective of this study was to investigate mineral precipitates, which derived from the zero valent iron (ZVI) corrosion during TCE dechlorination and to find the controlling factors in mineral precipitates. A series of column experiemnts were conducted to evaluate the location of ZVI and the effects of electrode arrangements in electro-enhanced permeable reactive barrier (E2PRB) systems. Based on mineralogical study, ZVI samples near the influent port had more lepidocrocite, ferrihydrite or Fe (oxy)hydroxide, and (phospho)siderite while backward samples had more akaganeite, magnetite/maghemite, and intermediate green rust (GR) I and GR II. A suite of mineral distribution was preferabley related to the dissolved oxygen and the increased pH. Controlling factors of mineral precipitates in an E2PRB system were found to be (1) pH, (2) dissolved oxygen, (3) the types of Fe intermediates, and (4) anionic species to form complex strongly.

Heme oxygenase-1 (HO-1)/carbon monoxide (CO) axis suppresses RANKL-induced osteoclastic differentiation by inhibiting redox-sensitive NF-κB activation

  • Bak, Sun-Uk;Kim, Suji;Hwang, Hae-Jun;Yun, Jung-A;Kim, Wan-Sung;Won, Moo-Ho;Kim, Ji-Yoon;Ha, Kwon-Soo;Kwon, Young-Guen;Kim, Young-Myeong
    • BMB Reports
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    • v.50 no.2
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    • pp.103-108
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    • 2017
  • Heme oxygenase (HO-1) catalyzes heme to carbon monoxide (CO), biliverdin/bilirubin, and iron and is known to prevent the pathogenesis of several human diseases. We assessed the beneficial effect of heme degradation products on osteoclastogenesis induced by receptor activator of NF-${\kappa}B$ ligand (RANKL). Treatment of RAW264.7 cells with CORM-2 (a CO donor) and bilirubin, but not with iron, decreased RANKL-induced osteoclastogenesis, with CORM-2 having a more potent anti-osteogenic effect. CORM-2 also inhibited RANKL-induced osteoclastogenesis and osteoclastic resorption activity in marrow-derived macrophages. Treatment with hemin, a HO-1 inducer, strongly inhibited RANKL-induced osteoclastogenesis in wild-type macrophages, but was ineffective in $HO-1^{+/-}$ cells. CORM-2 reduced RANKL-induced NFATc1 expression by inhibiting IKK-dependent NF-${\kappa}B$ activation and reactive oxygen species production. These results suggest that CO potently inhibits RANKL-induced osteoclastogenesis by inhibiting redox-sensitive NF-${\kappa}B$-mediated NFATc1 expression. Our findings indicate that HO-1/CO can act as an anti-resorption agent and reduce bone loss by blocking osteoclast differentiation.