• Title/Summary/Keyword: metal ion effect

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Study on the Hemolysin from Marine V. vulnificus (해양 V. vulnificus의 Hemolysin에 관한 연구)

  • 이봉헌;박흥재
    • Journal of Environmental Science International
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    • v.6 no.3
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    • pp.225-229
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    • 1997
  • A halophilic V. vulnificus is an estuarine microorganism that has been associated with fatal wound Infection and life-threatening septicemia. Hemolysin is defined as toxic substance produced by various species of bacteria Including V. vulnificus. Hemolysin from marine V. vulnificus was purified and the effect of pH, temperature. metal ion on the activity of hemolysin, and thermostability of hemolysin were tested in this study. Hemolysin iysed the sheep red blood cell and the optimum pH was 8.0, the optimum temperature was 4$0^{\circ}C$, and $K^+$ increased but $Mn^{2+}$ decreased the hemolyic activity of hemolysin, but hemolysin was unstable to heat.

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Effects of free metal ions and organo-metal complexes on the absorption of lead and cadmium by plants (식물에 의한 납, 카드뮴 흡수 기작에 미치는 자유이온 및 유기산-중금속 복합체의 영향)

  • Lee, Mina;Seo, Byounghwan;Kim, Kwon-Rae
    • Journal of Applied Biological Chemistry
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    • v.64 no.2
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    • pp.159-164
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    • 2021
  • Heavy metals exist in soils in various chemical forms including free metal ions and organo-metal complexes. The ratio of free metal ions has been known to be highly associated with the plant absorption of heavy metals. This study aims to understand the effect of free ions and organo-metal complexes on the absorption of lead (Pb) and cadmium (Cd) by plants. For this, lettuce grown in a hydroponic system for 28 days was consequently grown another 48 hours using Pb and Cd solutions. The ratios of free ion to organo-metal complexes in the solutions were adjusted at 100:0, 90:10, 70:30, 60:40 by four different organic acids (citric, oxalic, acetic, and humic acid). After that, the concentration of Pb and Cd in lettuce were analyzed. The Pb and Cd absorption by lettuce was more relied on the types of organic acids treated and the type of metals rather than the ratio of free metal ions. For example, citric acid increased the Pb absorption while it decreased the Cd absorption by lettuce. There was no significant relationship between free metal ion ratios and both Pb and Cd uptake by lettuce. It could be explained that citric acid, a relatively higher molecular weight organic acid, has higher ion binding capacity, so it forms organo-Pb complex easily due to the higher affinity of Pb on the binding site in comparison with Cd. Consequently, this complexation would assist Pb uptake by lettuce.

Study of Degradation of Organic matter using prepared Titania by Metal ions substitution process (금속이온 치환법으로 제조된 티타니아를 이용한 유기물 분해에 대한 연구)

  • Lee, Gyu-Hwan;Rhee, Dong Seok
    • Journal of Industrial Technology
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    • v.28 no.A
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    • pp.19-22
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    • 2008
  • In recent years, much attention has been paid to "Photocatalytic oxidation" as an alternative technique, where the pollutants are degraded by UV-irradiation in the presence of a semiconductor suspension such as titanium dioxide. $TiO_2$ is the most often used photocatalyst due to its considerable photocatalytic activity, high stability, non-environmental impact and low cost. 1n this research, the photocatalytic degradation of humic acid, acetaldehyde and methylene blue in $UV/TiO_2$ systems has been stydied. The effect of calcination temperature for manufacturing of $TiO_2$ photocatalysts and type of photocatalysts on photodegradation has been investigated. Photocatalysts with various metal ions(Mn, Fe, Cu and Pt) loading are tested to evaluate the effects of metal ions impurities on photodegradation. The photodegradation efficiency with $Pt-TiO_2$ or $Fe-TiO_2$ or $Cu-TiO_2$ is higher than Degussa P-25 powder. However, the photodegradation efficiency with $Mn-TiO_2$ is lower than Degussa P-25 powder. The photocatalytic properties of the nanocrystals were strongly dependent upon the crystallinity, particle size, standard reduction potential of various transition metal and electronegativity of various transition metal. As a result photocatalysts with various metal ion loading evaluated the effect of photodegradation.

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The stable e-beam deposition of metal layer and patterning on the PDMS substrate (PDMS 기판상에 금속층의 안정적 증착 및 패터닝)

  • Baek, Ju-Yeoul;Kwon, Gu-Han;Lee, Sang-Hoon
    • Journal of Sensor Science and Technology
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    • v.14 no.6
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    • pp.423-429
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    • 2005
  • In this paper, we proposed the fabrication process of the stable e-beam evaporation and the patterning of metals layer on the polydimethylsiloxane (PDMS) substrate. The metal layer was deposited under the various deposition rate, and its effect to the electrical and mechanical properties (e.g.: adhesion-strength of metal layer) was investigated. The influence of surface roughness to the adhesion-strength was also examined via the tape test. Here, we varied the roughness by changing the reactive ion etching (RIE) duration. The electrode patterning was performed through the conventional photolithography and chemical etching process after e-beam deposition of $200{\AA}$ Ti and $1000{\AA}$ Au. As a result, the adhesion strength of metal layer on the PDMS surface was greatly improved by the oxygen plasma treatment. The e-beam evaporation on the PDMS surface is known to create the wavy topography. Here, we found that such wavy patterns do not effect to the electrical and mechanical properties. In conclusion, the metal patterns with minimum $20{\mu}m$ line width was produced well via the our fabrication process, and its electrical conductance was almost similar to the that of metal patterns on the silicon or glass substrates.

The Influence of Aqueous Ionic, Condition on the Adsorption Features of Fluoride Ion on Waste Oyster Shell (수중 이온 환경이 폐굴껍질에 대한 불소 이온의 흡착 양상에 미치는 영향)

  • Lee, Jin-Sook;Kim, Dong-Su
    • Journal of Korean Society on Water Environment
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    • v.23 no.3
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    • pp.314-318
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    • 2007
  • The feasibility of the employment of waste oyster shell as an adsorbent for fluoride ion has been tested by considering the effect ionic condition on the adsorption of fluoride ion on oyster shell. The adsorption capacity of oyster shell for fluoride ion was found not to be significantly influenced by the ionic strength of aqueous environment. The existence of complexing agent such as nitrilotriacetic acid in wastewater decreased the adsorbed amount of fluoride ion by forming a stable complex of $CaT^-$ and the adsorption reaction of fluoride ion on oyster shell was examined to be endothermic. The coexisting heavy metal ionic adsorbate in wastewater hindered the adsorption of fluoride ion, however, its adsorbed amount was increased as the particulate size of adsorbent was decreased. Finally, a serial adsorption column test has been conducted for a practical application of adsorption process and the breakthrough of the column adsorption was observed in 22 hours under the experimental condition.

Studies on the Complexes of Lanthanide ion with Multidentate Ligand (I). Determination of Thermodynamic Parameters with Solution Calorimetric Method in Nonaqueous Solvents (란탄족 원소의 여러자리 리간드 착물에 관한 연구 (제 1 보) 물아닌 용액에서 용액열량계에 의한 열역학적 함수결정)

  • Sam-Woo Kang;Won-Hae Koo;Soo-Min Lee;Chang Choo-Hwan;Moo-Yol Seo
    • Journal of the Korean Chemical Society
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    • v.33 no.6
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    • pp.588-595
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    • 1989
  • Log K, ${\Delta}$H and ${\Delta}$S for the complexation of $La^{3+},\;Ce^{3+}$ and $Eu^{3+}$with various multidentate ligand containing crown ether, diaza crown ether and diamine ether have been determined in methanol and acetonitril solutions at $25^{\circ}C$ by solution calorimetric titration method. The greater stability constant of $La^{3+}$-15C5 than those of 18C6 diaza [2.2] in methanol are discussed in terms of the size of metal ion and the ligand cavity and of metal ion solvation. The stabilities of $Ce^{3+}$ and $La^{3+}$ ion complexes with a various multidentate ligand in acetonitril are in the order of (diamine ether)<18C6<15C5$Ce^{3+}$, $La^{3+}$ and $Eu^{3+}$-diaza [2.2] complexes in acetonitril are increased with the following order: $Eu^{3+}$ < $La^{3+}$ < $Ce^{3+}$, that is increasing order of the optimum size and of the charge density of metal ion.

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The Adsorption Effect of Filter Paper on the Results of Trace Analysis (거름종이에 의한 흡착이 미량 분석 결과에 미치는 영향)

  • Lim, Heon-Sung;Lee, Sueg-Geun
    • Analytical Science and Technology
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    • v.17 no.1
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    • pp.82-84
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    • 2004
  • The quantitative trace analysis of ions could be deteriorated by filter papers because of the effect of adsorption. Generally the adsorption of anions on filter paper did not occurred. Instead, $Cl^-$ and $NO{_3}^-$ ions were extracted from the filter papers. However, most metal ions were adsorbed on the filter papers by the formation of hydroxide in neutral solution. The adsorption of metal ions except $Ag^+$ ion could be avoided depend on the acid concentrations.

Decomposition of Hydrogen Peroxide in Fenton Systems (펜톤 시스템에서의 과산화수소 분해연구)

  • Mok, Young-Sun;Jo, Jin-Oh;Kim, Seok-Tae;Jeong, Woo-Tae;Kang, Duk-Won;Rhee, Byong-Ho;Kim, Jin-Kil
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.1
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    • pp.68-73
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    • 2007
  • In this study, we investigated the decomposition of highly concentrated hydrogen peroxide in the range of 1.04-2.55 M by transition metal ion catalysts such as $Fe^{2+}$ and $Cu^{2+}$. The effect of metal ion concentration on the decomposition of hydrogen peroxide was examined experimentally, and the decomposition rate constants were determined by combining the experimental data with a theoretical approach. The rate of the decomposition of hydrogen peroxide was found to be first order with respect to its concentration. The decomposition rate constant was able to be treated as a linear function of the initial metal ion concentration. The validity of the decomposition rate constants determined was verified by good agreements between the calculated and experimental results.

HSP27 MODULATION OF IMPLANT- ASSOCIATED METAL ION CYTOTOXICITY OF OSTEOBLASTIC CELLS (임프란트에 관련된 금속이온의 조골세포에 대한 세포독성에 미치는 Hsp27의 영향에 대한 실험적 연구)

  • Yoon, Jung-Ho;Ha, Dong-Jin;Rim, Jae-Suk;Kwon, Jong-Jin;Jang, Hyon-Seok;Lee, Eui-Seok;Kim, Dae-Sung
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.2
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    • pp.127-135
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    • 2006
  • Objectives: The extent of bone formation that occurs at the interface of metallic implants and bone is determined by the number and activity of osteoblastic cells. Stress proteins may be contributing determinants of cell viability in altered environments. Hsp27 is a small Mr hsp which is known as a molecular chaperone. Methods: To better understand how heat shock protein 27 contributes to endosseous implant - associated metal ions affects on osteoblastic cell viability, the effect of chromium and titanium ions were compared to effects of cadmium ions in the ROS17/2.8 osteoblastic cell line. Results: ROS17/2.8 osteoblastic cell line demonstrated ion - specific reductions in growth; reductions were significantly greater for cadmium than for chromium or titanium. Chromium impaired growth of cultures without altering cell viability measured using the MTT assay. A stable transformed cell line expressing additional hsp27(clone "A7") was resistant to the toxic effects of titanium and partially protected from cadmium toxicity. Conclusions: A role for hsp27 in protection of osteoblastic cells from metal ion toxicity is supported by the chromium - induced elevations in hsp27 abundance and the behavior of the A7 cell line in response to metal ions in culture. Similar biochemical responses to altered cellular environments may contribute to the fate of tissues adjacent to select metallic implants.

Complex of zinc(II) with tetraaza macrocyclic ligands in solution (용액에서 Zn(II)이온과 tetraaza 거대고리 리간드의 착물)

  • Koh Kwang-Oh
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.4
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    • pp.733-737
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    • 2006
  • In this paper, we report the coordination state and structure of $Zn(cyclam)Cl_{2})$ complex that was studied by the Raman spectrum and conductivity method. The complex of zinc(II) ion with 1,4,8,11-tetraazacyclotetradecane(cyclam) ligand is formed in aqueous solution. According to the Raman spectrum of $Zn(cyclam)Cl_{2})$ complex, $H_{2}O$ molecule and $Cl^{-}$ ion compete for the trans coordination site of zinc(II) ion. We also have investigated the competition effect of $H_{2}O$ molecule and $Cl^{-}$ ion by the conductivity method. On addition of 1,4,8,11-tetraazacyclotetradecane(cyclam) ligand to the aqueous $ZnCl_{2}$ solution, 2: 1 electrolyte is changed to 1:1 electrolyte. We suggest the possibility of elimination of heavy metal because of the affinity effect of macrocyclic polyamine(1,4,8.11-tetraazacyclotetradecane) for the heavy metal,.

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