• Animal cells and systems
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• 제7권3호
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• pp.173-186
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• 2003

The transition metal cadmium is a serious occupational and environmental toxin. To inhibit cadmium-induced damage, cells respond by increasing the expression of genes that encode stress-responsive proteins. The metal-regulatory transcription factor 1 (MTF-1) is a key regulator of heavy-metal induced transcription of metallothionein-I and II and other genes in mammals and other metazoans. Transcriptional activation of genes by MTF-1 is mediated through binding to metal-responsive elements in the target gene promoters. Phosphorylation of MTF-1 plays a critical role in the cadmium-inducible transcriptional activation of metallothionein and other responses. Studies using inhibitors indicate that multiple kinases and signal transduction cascades, including those mediated by protein kinase C, tyrosine kinase and casein kinase II, are essential for cadmium-mediated transcriptional activation. In addition, calcium signaling is also involved in regulating metal-activated transcription. In several species, cadmium induces heat shock genes. Recently much progress has been made in elucidating the cellular machinery that regulates this metal-inducible gene expression. This review summarizes these recent advances in understanding the role of some known cadmium-responsive genes and the molecular mechanisms that activate metal-responsive transcription factor, MTF-1.

• The Korean Journal of Ecology
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• 제21권3호
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• pp.217-224
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• 1998

The heavy metal concentrations of seawater collected from the Onsan coastal zone in February and July 1996 and mussels(Mytilus edulis) in February 1997 were analysed. The concentrations of cadmium in seawater were in the range of 0.008-2.988 ${\mu}g/L$, while the ranges of copper and zinc concentrations were 0.08-2.55, and 0.21-35.12 ${\mu}g/L$, respectively. The metal concentrations decreased gradually with increasing distances from Daejeong stream, indicating that this stream was the major source of heavy metal input into the Onsan coastal zone. The concentrations of cadmium, copper and zinc in mussels were in the ranges of 1.40-25.09, 8.5-64.5, and 46.8-291.2 ${\mu}g/g$, respectively. The metal concentrations decreased gradually with increasing distances from Daejeong stream. Among organs of mussels, gill showed the highest concentrations of cadmium and the digestive gland showed the highest concentrations of copper and for zine the kidney showed the highest concentrations. The digestive gland and kidney revealed high proportion of cadmium in cytosolic fraction and the percentage of copper was high in the kidney and that of zine was high in the digestive gland. Metal-binding protein of mussels collected from the mouth of Daejeong stream was separated, using gel-filtration chromatography. In the kidney and gill of mussels, most of cadmium was associated with metal-binding protein. In contrast, most of the metal in the digestive gland and remaining tissues is bound to high molecular weight protein rather than metal-binding protein.

• 대한의생명과학회지
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• 제10권4호
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• pp.453-457
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• 2004

The welders and car painters are frequently exposed to heavy metals such as lead, zinc, cadmium and chromium, and those are a major source of heavy metal poisoning. This study was carried out to investigate the relationship of the heavy metal level in blood by age, working duration, and smoking status among 105 industrial workers and 88 general people in Gyeongnam province from October 2003 to October 2004. The heavy metal level in blood was analyzed by atomic absorption spectrophotometer. Mean blood lead level in exposed group and control group was 8.40±4.67μl/dl, 1.82±1.35μl/dl, respectively. Mean blood zinc level in exposed group and control group was 9.43±5.38 ㎍/ml, 2.89±1.79㎍/ml, respectively. Mean blood cadmium level in Exposed group and control group was 1.53±1.05μl/dl, 0.60±0.49 μl/dl, respectively. Mean blood chromium level in exposed group and control group was 0.89±0.76μl/dl, 0.68±0.63μl/dl, respectively. Lead, zinc, cadmium and chromium level in blood of exposed group was significantly higher than that of control group. In the comparison of smoking status, lead, zinc and cadmium level of smoker's was significantly higher than that of non-smoker's. Comparison of heavy metal level by age, lead, zinc, cadmium level in 40's, 50's (exposed group) in blood significantly higher than that of 20's, 30's. In exposed group, working duration has no significant difference. In conclusion, smoking was the most hazardous factor to elevate in blood heavy metal levels.

• 통합자연과학논문집
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• 제4권2호
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• pp.130-136
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• 2011

This study investigated the adsorption characteristics of nickel, zinc and cadmium ions from the aqueous solution onto the alginate bead. Adsorption equilibrium capacities of the heavy metal ions increased with increasing initial pH of the solution. The adsorption equilibrium isotherm of the heavy metal ions was well represented by Langmuir equation. The magnitude of adsorption capacity of the heavy metal ions onto alginate bead was the order of cadmium > zinc > nickel. Kinetic parameters were measured in a batch adsorber to analyze the adsorption rates of the heavy metal ions. The internal diffusion coefficient of the heavy metal ions in the intraparticle were determined by comparing the experimental concentration curves with those predicted from the surface diffusion model (SDM) and pore diffusion model (PDM). The internal diffusion of the heavy metal ions in the intraparticles was explained by PDM.

• The Korean Journal of Ecology
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• 제22권2호
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• pp.95-100
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• 1999

The heavy metal concentrations in seawater and winkles (Littorina brevicula) collected from the Onsan bay area in southeast of Korea were analyzed. The heavy metal concentrations in the seawater obtained from the most polluted site showed approximately 189. 205. and 110 fold higher cadmium, copper. and zinc concentrations, respectively. than the uncontaminated control site. The contamination levels of these metals in winkles were 11.08 - 2.35, 334.5 - 212.5, and 426.0 - 499.2$\mu\textrm{g}$ per gram dry body weight. respectively. The concentrations of all three metals in both the seawater and winkles decreased gradually with increasing distance from Daejeong stream, suggesting the stream being the major source of heavy metal input into the bay. Among the four body parts of digestive gland and gonad. gill. kidney, and remaining tissue in contaminated winkles, kidney showed the highest accumulation level of cadmium: copper and zinc, however. were more or less distributed among the four body parts. Upon gel filtration chromatography of the cytosol from the kidney of cadmium induced winkles, one cadmium peak corresponded to the elution peak of horse kidney metallothionein.

• Membrane and Water Treatment
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• 제5권3호
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• pp.183-195
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• 2014

The efficiency of two metal ions (cadmium, zinc) removal from aqueous solutions by ultrafiltration (UF) and Polymer Enhanced Ultrafiltration (PEUF) processes were investigated in this work. The UF and PEUF studies were carried out using an ultrafiltration tangential cell system equipped with 5.000 MWCO regenerated cellulose. A water-soluble polymer: the polyacrylic acid (PAA) was used as complexant for PEUF experiments. The effects of transmembrane pressure, pH, metal ions and loading ratio on permeate fluxes and metal ions removals were evaluated. In UF process, permeate fluxes increase linearly with increasing pH for different transmembrane pressure, which may be the consequence of the formation of soluble metal hydroxyl complexes in the aqueous phase. In PEUF process, above pH 5.0, the Cd(II) retention reaches a plateau at 90% and Zn(II) at 80% for L = 5. Also, cadmium retention at different L is greater than zinc retention at pH varying from 5.0 to 9.0. In a mixture solution, cadmium retention is higher than zinc for different loading ratio, this is due to interactions between carboxylic groups of PAA and metal ions and more important with cadmium ions.

• 한국환경과학회지
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• 제1권1호
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• pp.97-126
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• 1992

Greenhouse pot experiments were conducted to evaluate the effects of lime, fly ash and ash(from rice straw) on the cadmium and lead translocation from soil to radish. The soils with low metal contents(Cd 1.52 ppd and Pb 25.37ppm) were prepared and high metal contents (Cd 8.99 rpm and Pb 50.81ppm) were prepared and amended with 0.25%, 0.5%, 1.095, 2.055 each of lime, fly ash and ash. Radishes(Raphanus satiuus) were cultivated and cropped on the soils during 25, 50 and 75 days after sprout, and then cadmium and lead contents of radishes were analyzed by roots and tops. The results obtained are as follows. 1. Lime and ash were effective in raising the soil pH, but fly ash was not effective. 2. The growth of radishes were not impaired by the cadmium and lead contamination but, impaired by soil pH 7.5 or more. 3. Cadmium was accumulated very strongly in radishes and the greater concentration was found in tops than roots, but lead showed no evidence of accumulation in radishes. 4. In general, when the concentrations of lime and ash in soils increased, the uptake of cadmium and lead by radishes decreased, and lime was more effective than ash, while fly ash revealed no effect of reducing the translocation of cadmium and lead from soils to radishes. 5. The uptake of cadmium by radishes decreased more effectively than lead and the uptake of Cd or Pb by radishes grown in the soils with high metal contents decreased more effectively than low metal con tents. 6. Cadmium and lead contents of radishes were negatively correlated with soil pH values and the relationship in cadmium content was stronger than that in lead content.

• 공학기술논문지
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• 제4권4호
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• pp.431-436
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• 2011

This study was carried out to reduce the problem during distillation process, which separate U, TRU (TRans Uranium) metal electro deposit, Cd and LiCl-KCl eutectic salt generating from LCC (Liquid Cadmium Cathode) electro winning process. The cadmium recovering apparatus was manufactured to separate for each metal using solid-liquid separation method. The apparatus consists of the first sieve for the separation of U and TRU metal electrodeposit, the second sieve for the separation of LiCl-KCl eutectic salt, cadmium collection basket, and a heating furnace. In addition, the size of each sieve is 2 mm to 3 mm. In this experiment, a metal wire was employed to replace TRU metal electrodeposit and U, which exist actually in a LCC crucible. In the solid state, The LiCl-KCl is separated at 340℃ at which the solid and the liquid of the remaining cadmium and LiCl-KCl eutectic salt coexists in each, after the metal wire separated at 500℃. As a result, it seems that it would be beneficial to set the processing condition in the distillation process with the additional treatment process of cadmium and LiCl-KCl eutectic salt.

• The Korean Journal of Ecology
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• 제24권1호
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• pp.35-43
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• 2001

카드뮴과 아연에 각각 그리고 동시에 노출한 총알고둥(Littorina brevicula)에서 중금속의 생체내 축적, 제거 및 세포내 분포 양상을 조사하였다. 총알고둥을 카드뮴 400 $\mu\textrm{g}$/L 또는 아연 3000 $\mu\textrm{g}$/L에 각각 90일간 노출하였을 경우, 각 중금속의 축적량은 노출기간에 따라 증가하였으며, 70일 이후에는 더 이상 축적량이 증가하지 않았다. 카드뮴과 아연을 동시에 노출하였을 경우에는 각각의 중금속에 노출하였을 경우에 비해 아연의 축적량은 증가하였으나, 카드뮴의 축적량은 감소하였다. 노출실험에 이어 수행한 42일간의 청장실험 결과, 카드뮴은 체외로 제거되지 않았으나, 아연은 제거되었다. 특히 카드뮴과 아연에 동시 노출한 총알고둥의 경우에 아연은 더 신속히 제거되었다. 총알고둥을 카드뮴과 아연에 각각 70일 동안 노출한 후, 체내로 흡수된 카드뮴의 약 60%가 soluble fraction에 분포하고 있었으며, 아연의 75%는 insoluble fraction에 분포하고 있었다. 이러한 경향은 카드뮴과 아연의 동시 노출시에도 유사하게 나타났다. 카드뮴과 아연은 soluble part내의 리간드(ligand) 와의 결합 양상에서도 차이를 나타냈는데, 카드뮴은 90% 이상이 약 6.5 kDa크기의 MBP-1(Metal-Binding Protein-1)과 결합하고 있었으나, 아연은 HMW(High molecular weight fraction, >60 kDa), MBP-1, MBP-2, LMW(Low molecular weight fraction <1 kDa)에 고루 분포하는 것으로 나타났다.

• The Korean Journal of Ecology
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• 제19권6호
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• pp.519-527
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• 1996

To examine the possibility of biomonitoring of heavy metal removal ability and soil, a study was performed to investigate the heavy metal removal ability and metal-binding protein (MBP) as detoxification process using Oenanthe stolonifera. After O. stolonifera was exposed to individuals (cadmium, zinc) and mixture (cadmium+zinc)for 4 days, removal rate of heavy metal and pH in the treatment medium was measured. MBP was assayed by means of ion exchange column chromatography. The exposure to mixture (Cd:76.8%, Zn:75%) rather than individuals (Cd:82.9%, Zn:90.4%) showed a synergism raising the toxic effect. Initial removal rate was different for each heavy metal : in case of exposure to cadmium it was over 60% on day 1, while for zinc it was 75~90% on day 4. Throughout the experimental period, pH value of treatment medium continuously decreased, since cortex in the roots may secret organic acid to adjust and prevent toxicity of metals. The existence or MBP in the 70~80 fraction and the presence of Zn-enzyme pool was ascertained with the column chromatography. This study demonstrated a possibility that heavy utilized as a biomarker of heavy metal pollution.