• Title/Summary/Keyword: Mn-EDTA

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EDTA Surface Capped Water-Dispersible ZnSe and ZnS:Mn Nanocrystals

  • Lee, Jae-Woog;Lee, Sang-Min;Huh, Young-Duk;Hwang, Cheong-Soo
    • Bulletin of the Korean Chemical Society
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    • v.31 no.7
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    • pp.1997-2002
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    • 2010
  • ZnSe and ZnS:Mn nanocrystals were synthesized via the thermal decomposition of their corresponding organometallic precursors in a hot coordinating solvent (TOP/TOPO) mixture. The organic surface capping agents were substituted with EDTA molecules to impart hydrophilic surface properties to the resulting nanocrystals. The optical properties of the water-dispersible nanocrystals were analyzed by UV-visible and room temperature solution photoluminescence (PL) spectroscopy. The powders were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), and confocal laser scanning microscopy (CLSM). The solution PL spectra revealed emission peaks at 390 (ZnSe-EDTA) and 597 (ZnS:Mn-EDTA) nm with PL efficiencies of 4.0 (former) and 2.4% (latter), respectively. Two-photon spectra were obtained by fixing the excitation light source wavelengths at 616 nm (ZnSe-EDTA) and 560 nm (ZnS:Mn-EDTA). The emission peaks appeared at the same positions to that of the PL spectra but with lower peak intensity. In addition, the morphology and sizes of the nanocrystals were estimated from the corresponding HR-TEM images. The measured average particle sizes were 5.4 nm (ZnSe-EDTA) with a standard deviation of 1.2 nm, and 4.7 nm (ZnS:Mn-EDTA) with a standard deviation of 0.8 nm, respectively.

Utilization of Mineral Oxides to Attenuate Mn-EDTA and Fluoride (산화광물을 이용한 수중의 망간-EDTA, 불소 제거)

  • 현재혁;남인영
    • Journal of Korea Soil Environment Society
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    • v.1 no.2
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    • pp.51-60
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    • 1996
  • Removal of Mn-EDTA complex and fluoride by use of hematite and ferrite, which are the by-product to be disposed of as industrial wastes, was investigated. For the comparison of removal rate, Na-bentonite known as excellent absorbent of inorganic contaminants was included in the experiments. As the results of batch mode experiments, for manganese, ferrite-A revealed 48∼65% of removal capacity, ferrite-B 46∼57%, hematite 17∼26%, while Na-bentonite showed 10∼23% of removal, depending on the initial concentration. Meanwhile, in case of fluoride : hematite revealed 53 ∼63% of removal : ferrite-A 54∼63 %, while ferrite-B did 20∼38 %. From the results, it can be postulated that the capacity of hematite and ferrite to attenuate inorganic pollutants, especially when they form complex ions, is superior to that of Na-bentonite. Consequently, the mixing of such oxide minerals with Na-bentonite will reinforce the function of Na-bentonite, especially in the undergroud liner aspect.

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Enzymatic Properties of Serratia marcescens Pretense (Serratia marcescens Protease의 효소학적 특성)

  • 최병범
    • The Korean Journal of Food And Nutrition
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    • v.16 no.2
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    • pp.152-157
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    • 2003
  • Serratia marcescens ATCC 25419 protease was purified to homogeneity by ammonium sulfate treatment, and DEAE-cellulose anion exchange chromatography. The specific activity of the enzyme was increased 448-fold during purification with an overall yield of 43.0%. Metal reactivation on the purified protease from S. marcescens was studied. S. marcescens protease was a metalloenzyme to be completely inhibited its activity by EDTA and the enzyme outstandingly inhibited by Hg, Fe, Cu, but the activity was increased approximately 20% by Co. The reactivation of the apoenzyme was effective with Mn, Co, Zn in pH range from 6 to 8. Among metalloenzymes prepared to the addition of Mn, Co, Zn to restore the degree of activity of native enzyme, Zn-enzyme was similar to the native enzyme in respects with enzyme activity, alkali-inactivation, thermo-stability.

Extraction Characteristics of Heavy Metals for Soil Washing of Mine Tailings-contaminated Soil according to Particle Size Distribution (토양세척공정에서 광미오염토양 입자크기에 따른 중금속 추출특성)

  • Kim, Joung-Dae
    • Applied Chemistry for Engineering
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    • v.19 no.1
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    • pp.98-104
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    • 2008
  • This research was performed to evaluate the extraction characteristics of heavy metals for soil washing of mine tailings-contaminated soil according to particle size distribution and the chemical distributional existence of the metals. As the soil particle size was decreased, the extracted concentrations of heavy metals was increased except Fe and Mn. Most of all heavy metals were extracted within 6 h by soil washing with 0.05 M EDTA. Extraction efficiency of metals was decreased for Pb, Cu, and Zn with decreasing of particle size. Significant difference was not observed in extraction efficiency for Cd according to particle size distribution. Extraction efficiency for Cd was the highest as 86~91%, while the lowest as 5~14% for Fe. Most metals of the soil without soil washing was distributed as reducible, oxidizable, and residual fractions. Pb, Zn, and Cd existed as reducible (Fe/Mn oxide) and residual fractions and Cu existed as oxidizable and residual fractions after soil washing treatment with 0.05 M EDTA. As the soil particle size was decreased, residual fraction was increased for Pb and Cu. About 90% of reducible fraction in Pb, Zn, and Cd was removed by soil washing with 0.05 M EDTA. As the results, it was founded that soil particle size was the important parameter to effect on distributional fraction and extraction efficiency of metals in mine tailings-contaminated soil.

THE EFFECT OF SMEAR LAYER TREATMENT ON THE MICROLEAKAGE (Smear layer 처리에 따른 미세누출에 대한 연구)

  • Lee, Jung-Min;Park, Sang-Hyuk;Choi, Gi-Woon
    • Restorative Dentistry and Endodontics
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    • v.31 no.5
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    • pp.378-389
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    • 2006
  • The purpose of this study was to compare the sealing ability of root canal obturation with or without the treatment of smear layer. Eighty extracted human teeth with one canal were selected Instrumentation was performed with crown-down technique. After instrumentation, root canals of the NaOCl group and NaOCl-6 group were irrigated with 3% NaOCl. EDTA group and EDTA-6 group were irrigated with 17% EDTA. Then all teeth were obturated using continuous wane obturation technique NaOCl group and EDTA group were immersed in methylene blue solution for 84hours. NaOCl-6 group and EDTA-6 group were immersed in methylene blue solution for 6months. The teeth were sectioned at 1.5 mn (Level 1), 3.0 mm (Level 2) and 4.5 mm (Level 3) from the root apex. The length of dye-penetrated inter-face and the circumferential length of canal at each level were measured using Sigma-Scan Pro 5.0. 1. The mean leakage ratio was decreased cervically. 2. NaOCl group showed higher mean leakage ratio than EDTA group at each level. But there was significant difference at level 1 only (p < 0.05). 3. NaOCl-6 group showed higher mean leakage ratio than EDTA-6 group at each level. But there was significant difference at level 1 only (p < 0.05). 4. NaOCl-6 group showed higher mean leakage ratio than NaOCl group at each level. But there was significant difference at level 1 only (p < 0.05). 5. EDTA-6 group showed higher mean leakage ratio than EDTA group at each level. But there was no significant difference. 6. In NaOCl group and NaOCl-6 group, scanning electron micrographs of tooth sections generally covered with smear layer. In EDTA group and EDTA-6 group, tooth sections showing the penetration of sealers to opened dentinal tubules. The results suggest that removal of smear layer was effective to reduce the apical microleakage of the root canal.

Effective Method for Lend Extraction from Pb - Contaminated Soil with EDTA (EDTA를 사용한 납 오염 토양에서의 효율적인 납 추출)

  • 김철성
    • Journal of Korea Soil Environment Society
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    • v.4 no.1
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    • pp.3-11
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    • 1999
  • The effects of major cations in soils, soil : extractant ratio, and EDTA : lead stoichiometric ratio on the extraction efficiency of lead using EDTA were studied for 4 different actual lead-contaminated soils and one artificially lead-contaminated soil. Extraction of lead from the lead-contaminated soil was not affected by a soil : extractant ratio as low as 1 : 3 but instead was dependent on the quantity of EDTA present. Results of the experiments showed that the extraction efficiency for each soil was different, but if sufficiently large amount of EDTA was applied, all the lead may be extracted except for a soil from lead mining area. The differences in extraction efficiencies nay be due to the major cations present in soils which may compete with lead for active sites on EDTA. The total molar amount of major cations extracted was as muck as 20 times more than the added molar amount of EDTA. For some of the soils tested, the extraction efficiency of lead may be affected by being occluded in the Fe and Mn oxides present in the soil. While major cations present in the soil may be one of the factors affecting lead extraction efficiency, the type of lead species present may also play a role. When these factors affect severely, the using of EDTA to extract lead from lead-contaminated soil might be non-effective method.

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Determination of Neutron Absorption Fraction Factor in Manganese Sulfate Bath System (황산망간 용액조 장치의 중성자 흡수분율 보정인자 결정)

  • Lee, Kyung-Ju;Park, Kil-Oung;Hwang, Sun-Tae;Lee, Kun-Jai
    • Nuclear Engineering and Technology
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    • v.21 no.1
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    • pp.12-17
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    • 1989
  • The correction factor of neutron fraction absorbed by $^{55}$ Mn in the MnSO$_4$ bath was determined for the absolute measurement of neutron emission rate by using the solution circulation-type manganese sulfate bath system. For the determination of this correction factor, I/f, the atomic number desnsity and the effective neutron capture cross section data of Mn, S and impurity elements in the MnSO$_4$ solution were determined. For the atomic number density determination, the MnSO$_4$ solution concentration was determined by using the volumetric EDTA titration and gravimetric method. The impurity contents were analyzed by using the ICP method. For the calculation of effective neutron capture cross sections, a FORTRAN computer program EASCAL was developed in this study. in which Westcott's parameters and Axton's empirical relations are used.

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Characterization of an Antioxidant from Sporophyll of Undaria pinnatifida (미역 포자엽에서 분리한 항산화 물질의 특성)

  • Yang, Ji-Yeong;Yu, Mi-Yeong;Kim, Sang-Gwon
    • Microbiology and Biotechnology Letters
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    • v.32 no.4
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    • pp.307-311
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    • 2004
  • Hot water soluble extract from sporophyll of Undaria pinnatifida was examined for antioxidant activity using l,l-diphenyl-picrylhydrazyl (DPPH) and lipid peroxidation assay. The $IC_{50}$ value (7.6 mg/ml) of hot water extract from sporophyll of U. pinnatifida was more higher than ascorbic acid (0.025 mg/ml) and BHT (0.25 mg/ml). The hot water extract from sporoof U. pinnatifida was stable from pH 2 to pH 7 but decreased at alkali pH. The heat stability of hot water extract from sporophyll of U. pinnatifida was stable from $0^{\circ}C$ to $120^{\circ}C$. An effect on an antioxidant activity of hot water extract from sporophyll of U. pinnatifida was studied with various metal ions and EDTA. Antioxiactvity of hot water extract from sporophyll of U. pinnatifida was inhibited by EDTA but increased by adding $Cu^{2+}$, $Co^{2+}$ and $Mn^{2+}$, respectively.

Remediation of Heavy Metal Contamination in OBOD Site with Soil Washing : Selection of Extractants (토양세척법에 의한 중금속오염 폐탄처리장 토양의 정화 : 세척액의 선정)

  • Lee, Sang-Hwan;Kim, Eul-Young;Seo, Sang-Kee;Kim, Gweon-Bo;Kim, Jae-Hwan;Lee, Jong-Keun
    • Journal of Soil and Groundwater Environment
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    • v.13 no.2
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    • pp.44-53
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    • 2008
  • The efficiences of mineral acid (HCl), neutral salts ($CaCl_2$), and chelating agent (citric acid and $Na_2$-EDTA) were tested for extracting heavy metals from open burning and open detonation (OBOD) site soil. The extraction efficiencies of Cd, Cu, Pb and Zn from soil for various extractants were in the order of HCl > citric acid > $Na_2$-EDTA > $CaCl_2$, HCl (1.0 M) extracted effectively 82%, 86%, 80%, and 46% of initial total concentrations of Cd, Cu, Pb, and Zn, respectively. Significant negative correlations were observed between pH of extractant and amount of extracted heavy metals. Initially, examined heavy metals were predominantly bound to carbonate and Fe, Mn-oxide fraction. Though the significant amount of carbonate and Fe, Mn-oxide bounded metals were removed but a significant amount remained metals shifted to exchangeable (more mobile) fraction by HCl and citric acid extraction. The increased mobility of remaining metals could be problematic for water resources, thus careful management is needed to control the movement of heavy metals.

A Caseinolytic Enzyme in Human Follicular Fluid (사람 난표액의 Caseinolytic Enzyme)

  • Shim Myung-Sun;Kim Haekwon
    • Development and Reproduction
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    • v.7 no.2
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    • pp.113-118
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    • 2003
  • Follicular fluid(FF) of mammalian Graafian follicles contains various kinds of proteins and proteinases that are believed to play important roles during follicular growth oocyte maturation and ovulation of mature oocytes. Previous studies of human FF(hFF) demonstrated the presence of many serine/threonine proteinases and matrix metalloproteinases such as gelatinases, however, little is known about the caseinases. Present study was aimed to examine the presence and the property of caseinolytic enzyme in hFF. Using casein zymographic method, it was found that hFF, human adult serum and cord serum exhibited one intense 80 kDa and another weak 78 kDa bands having caseinolytic activity. When inhibitors were added to the zymographic substrate buffer, caseinolytic activity of both 80 kDa and 78 kDa proteins were inhibited by othylenediarnine tetraacetic acid(EDTA) or soybean trypsin inhibitor(SBTI), but not by E-64, phenylmethylsulfonyl fluoride(PMSF) or 1,10-phenanthroline. Thus both enzymes appear to belong to a family of trypsin-like enzyme. Addition of EDTA to the zymographic substrate buffer almost abolished the caseinolytic activity of both enzymes. However, further addition of a divalent metal ion such as CaC $l_2$, MgC $l_2$, MnC $l_2$ or ZnC $l_2$ to the same buffer fully restored the enzyme activity at 5 mM concentration despite the presence of EDTA. Based upon these observations, 80 kDa and 78 kDa caseinolytic enzymes are present in human follicular fluid and they appear to be trypsin-like enzymes of which caseinolytic activity needs the presence of $Ca^{++}$, aM $g^{++}$, M $n^{++}$ or Z $n^{++}$././././.

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