• Journal of Animal Science and Technology
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• 제49권3호
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• pp.415-428
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• 2007

To investigate the detoxification effect of pork on the lead toxicity, the comparison tests were performed, in which Sprague Dawley(SD) rats were clinically treated with lead during the first 7 weeks and observed the detoxification effects induced by pork feeding during the second 7 weeks. As results of lead intoxication, decreases of body weight, hemoglobin and hematocrit and the increases of weight and relative organ weight of liver and kidney were observed. Also the accumulation of lead in tibia, kidney and liver was recognized. In case of pork feeding at detoxification stage the feed efficiency was significantly increased in pork feeding group rats than the those of control rats. The pork feeding seemed to be a factor affecting relative organ weight of liver and kidney(p<0.05). It was shown that the factors affecting the accumulation of lead in liver included the lead intoxication(p<0.0005), pork feeding(p<0.0005) and interaction of above two(p<0.0005). It was observed that the content of DALAD in liver increased with significance in pork fed group compared with control group regardless of lead treatment levels. From this result, it was considered that pork feeding improved the detoxification process of SD rats intoxicated with lead.

• Journal of Environmental Science International
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• 제9권3호
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• pp.209-214
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• 2000

The preventive effects of sodium molybdate on the acute toxicity of lead were studied by investigating tissue accumulation of lead, changes of nerve conduction velocity and concentrations of metabolites related to function of sciatic nerve in rats treated with lead, sodium molybdate and both, respectively. In lead-intoxicated rat, the conduction velocity, myo-inositol concentration and $Na^{+}/K^{+}$ ATPase activity of sciatic nerve were decreased by about 33 %, 48 % and 58 %, respectively. However, sodium molybdate treatment significantly normalized the conduction velocity, $Na^{+}/K^{+}$ ATPase activity and myo-inositol concentration of sciatic nerve in lead-intoxicated rat. Also, sodium molybdate treatment decreased the contents of lead in blood and sciatic nerve through promotion of urinary excretion of lead. But sodium molybdate treatment did not affect the glucose concentration in sciatic nerve. These results suggest that sodium molybdate prevented peripheral neuropathy not only by reducing lead contents in sciatic nerve and blood, but also by enhancing $Na^{+}/K^{+}$ ATPase activity in sciatic nerve.

• The Journal of Internal Korean Medicine
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• 제22권2호
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• pp.193-198
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• 2001

This study was designed to investigate the effects of Korean Lycii Fructus water extract in Pb-administered rats. The Pb exposed rats were given 100 ppm and 200 ppm in the distilled water. Sixty male Sprague-Dawley rats weighing between 90 and 110g were blocked into 6 groups according to body weight. The control group was fed a normal diet, without lead. The experimental groups, which was fed a normal diet plus 100 ppm and 200 ppm lead, and one group received a normal diet plus Lycii Fructus water extracts. The results: the Food intake, the weight gain, and the kidney weight content in the cadmium added groups were lower than those in the Lycii Fructus water extracts group. The contents of Pb in the kidneys of the rats were determined by using ICP(lnductively Coupled Plasma Spectrophotometer). The accumulation of lead in the kidney was lower in the Lycii Fructus water extracts group. The Plasma levels of renin activity was higher in the lead administration groups, as compared with the Lycii Fructus water extracts. Plasma levels of aldosterone activity was higher in the lead administration group, as compared with Lycii Fructus water extracts. These results suggest that Lycii Fructus water extracts has a lowering effects on the accumulation of pb on kidney and it is believed that the Lycii Fructus water extracts have some protective effects on lead-induced nephrotoxicity in rats, but the mechanism of these effects was obscure.

• Korean Journal of Environmental Agriculture
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• 제16권2호
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• pp.142-148
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• 1997

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri possessing the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewaters and mine wastewaters polluted with various heavy metals. The effect of competing ions and metabolic inhibitors on heavy metal accumulation in the cells was investigated. Heavy metal accumulation into cells was drastically decreased in the presence of competing cation, $Al^{3+}$, and also decreased, at a lesser extent, in the presence of competing anions, $CO_3\;^{2-}$ and $PO_4\;^{2-}$. But heavy metal accumulation was not influenced generally in the presence of the other rations and anions. The accumulation of Cd, Zn or Cu by Cd-, Zn- or Cu-tolerant microorganism was remarkably decreased in the presence of metabolic inhibitors, but the accumulation of Pb by Pb-tolerant microorganism was little affected in the presence of metabolic inhibitors. These results suggested that the accumulation of Cd, Zn or Cu by Cd-, Zn- or Cu-tolerant microorganism was concerned with the biological activity depending on energy, and the accumulation of Pb by Pb-tolerant microorganism depended on not the biological activity but the physical adsorption on the cell surface. Each heavy metal-tolerant microorganism also exhibited some ability to accumulate the other heavy metals in solution containing equal concentrations of cadmium, lead, zinc and copper, when measured at 48 hours after inoculation of the microorganisms, but the accumulation rates were somewhat low as compared to the accumulation rates of heavy metal fitting to each tolerance. These results suggested that the accumulation of each heavy metal by each heavy metal-tolerant microorganism was a selective accumulation process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.1008-1011
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• 2005

It is necessary for the design of lead frame punches in blanking to consider buckling because inner lead pitch of lead frame has been narrowed by miniaturization and high accumulation of semiconductor. In addition, if process variables change in press stamping process, the lift of punches is no longer influenced in wear and punches can be broken suddenly. To prevent the fracture of fine pitch lead frame punches, having considered applying reinforcement to it, this paper verified the design with buckling analysis. This study presents the optimal position and number of reinforcement to be attached to punches. Finally this study presents design rules of attaching reinforcement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마연구회
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• pp.1-5
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• 2003

This paper presented the effects of accumulation of surface charges on hydrophobicity level and the surface states of silicone polymer used for outdoor insulator treated by ultraviolet irradiation and corona discharge through measuring surface voltage decay of a corona-charged specimen were investigated. The surface resistivity by the method of the surface potential decay was compared with the value by the three electrodes methods. From this study, it was found that the accumulation of surface charges above a critical surface voltage on silicone insulating materials could lead to the temporary loss of surface hydrophobicity. In addtion, uv stress lead to a longer decay time of surface charges. We could conclude that the effects of surface charges on hydrophocity level and the changes of surface state by various artificial treatments were understood through a trend of surface potential decay.

• Journal of Environmental Health Sciences
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• 제19권4호
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• pp.67-82
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• 1993

This study was performed to investigate the preventive effect of KDD against lead toxicity. KDD of 133, 266, 532 and 1,064 mg/kg were administered twice to the rats of Sprague-Dawley strain and then 300 mg/kg lead acetate was given to times, respectively. 1. The accumulation effects of KDD against to lead showed the changes of lead concentration by time variation. But, no statistical significance were showed on 8 and 10 weeks for kidney, spleen, 8 weeks for liver, and 4, 6 and 8 weeks for duodenum. In the femur, statistical significance existed during the whole experimental period. The relatively high concentration of lead detected in the feces of the experimental group means that KDD facilitated excretion of lead. 2. The histopathological effect of KDD against lead showed cytomegaly, karyomegaly, inclusion body, urinary cast and hemosiderin of kidney in the experimental group I (Pb 300 mg/kg). Recovery of KDD administrated group was inclined to increase by KDD concentration. But, spleen's histopathological recovery of KDD aginst to lead did not show as much as kidney. In conclusion, this study revealed the preventive effect of KDD against lead toxicity and its mechanism inferred to facilitate lead excretion in feces following hinderance of lead absorption in the gastric-intestine and organs.

• 한국생태학회:학술대회논문집
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• 한국생태학회 2002년도 VIII 세계생태학대회
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• pp.119-125
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• 2002

Application of phytoremediation in the polluted area to remove undesirable materials is a complex and difficult subject without detailed investigation and experimentation. We investigated the accumulation patterns of cadmium and lead in plants naturally grown, the bioavailability of plants to accumulate these toxic metals and the responses of P. thunbergii to cadmium and lead. The soil samples contained detectable lead (<17.5$\mu\textrm{g}$/g), whereas cadmium was not detected in the soils of study area. The whole body of Persicaria thunbergii contained detectable lead (<320.8$\mu\textrm{g}$/g) but cadmium was detected only in the stem (<7.4$\mu\textrm{g}$/g) and root (<10.4$\mu\textrm{g}$/g) of P. thunbergii. Cadmium was not detected in Trapa japonica and Nymphoides peltata, whereas lead was detected in T. japonica (<323.7$\mu\textrm{g}$/g) and N. peltata (<177.5$\mu\textrm{g}$/g). Correlation coefficient between lead content in soil and in these plant samples represented positive correlation. The total content of lead in each plant sample increased in the order of N.peltata$\leq$P.thunbergii

• The Korean Journal of Ecology
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• 제25권4호
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• pp.253-259
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• 2002

Application of phytoremediation in the polluted area to remove undesirable materials is a complex and difficult subject without detailed investigation and experimentation. We investigated the accumulation patterns of cadmium and lead in plants naturally grown, the bioavailability of plants to accumulate these toxic metals and the responses of P. thunbergii to cadmium and lead. The soil samples contained detectable lead (＜$17.5_\mu$g/g), whereas cadmium was not detected in the soils of study area. The whole body of Persicaria thunbergii contained detectable lead (＜320.$8_\mu$g/g/g) but cadmium was detected only in the stem (＜7.$4_\mu$g/g/g) and root (＜10.$4_\mu$g/g/g) of P. thunbergii. Cadmium was not detected in Trapa japonica and Nymphoides peltata, whereas lead was detected in T. japonica (＜323.$7_\mu$g/g/g) and N. peltata (＜177.$5_\mu$g/g/g). Correlation coefficient between lead content in soil and in these plant samples represented positive correlation. The total content of lead in each plant sample increased in the order of N. peltata$\leq$P. thunbergii

• Toxicological Research
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• 제29권4호
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• pp.235-240
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• 2013

Extracellular accumulation of amyloid beta protein ($A{\beta}$) plays a central role in Alzheimer's disease (AD). Some metals, such as copper, lead, and aluminum can affect the $A{\beta}$ accumulation in the brain. However, the effect of mercury on $A{\beta}$ accumulation in the brain is not clear. Thus, this study was proposed to estimate whether mercury concentration affects $A{\beta}$ accumulation in PC12 cells. We treated 10, 100, and 1000 nM $HgCl_2$ (Hg) or $CH_3HgCl_2$ (MeHg) for 48 hr in PC12 cells. After treatment, $A{\beta}_{40}$ in culture medium increased in a dose- and time-dependent manner. Hg and MeHg increased amyloid precursor protein (APP), which is related to $A{\beta}$ production. Neprilysin (NEP) levels in PC12 cells were decreased by Hg and MeHg treatment. These results suggested that Hg induced $A{\beta}$ accumulation through APP overproduction and reduction of NEP.