• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.12
• /
• pp.1775-1779
• /
• 2005

Seventy-two crossbred gilts of approximately 33 kg initial weight were used in this study. The gilts were randomly assigned into three groups. The three dietary treatments were basal diet only (control group), basal diet+10 mg/kg lead, and basal diet+10 mg/kg lead+0.5% particulate montmorillonite (PM). The results showed that the addition of lead to the diet decreased significantly the body weight and feed efficiency, but PM could restore body weight and feed efficiency of gilts compared to the Pb exposure group. There were no significant differences in weights of ovaries and uteri with addition of either lead or PM to the diet. Supplementing the lead in the diet of gilts also significantly increased the concentration of lead in blood, decreased circulating lutenizing hormone (LH) and estradiol (E$_2$) levels in serum, the addition of PM to the diet effectively adsorbed and lowered lead concentration in the blood. These data suggested that lead disrupts the signals between the hypothalamus and pituitary gland in gilts, and possibly suppressed the secretion of relative growth hormone and sex hormone. On the other hand, PM may ameliorate Pb toxicity in pigs.

• Journal of environmental and Sanitary engineering
• /
• v.18 no.2
• /
• pp.60-66
• /
• 2003

This study was carried out to elucidate the preventive mechanism of molybdenum on lead-induced neuropathy, An animal model of lead neuropathy was induced by feeding diet containing lead to Sprague-Dawley rat for three weeks. Four weeks aged Sprague-Dawley rats were divided into four groups : normal control group, 10ppm-lead treated group, 1mg/kg-molybdenum treated group, 10ppm-lead and 1mg/kg-molybdenum treated group. The parameters on neuropathy were examined by measuring concentration of myo-inositol and myo-inosito uptake in sciatic nerve. In the lead-treated rats, myo-inositol concentration and myo-inositol uptake rate were reduced by from 54% to 33% respectively. This deficit results from that myo-inositol uptake system which is carrier mediated and sodium-potassium dependent was inhibited by the lead treatment. However, the molybdenum administration significantly eliminated the impairment and maintained myo-inositol concentration to about 82% of normal level. These results suggest that lead-induced neurotoxicity was significantly reduced by administration of molybdenum and the mechanism might be partly normalization of myo-inositol uptake system in sciatic nerve.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.56 no.2
• /
• pp.65-73
• /
• 2007

In this study, the pulse charger and voltage regulator are proposed that can reuse the waste lead acid battery. The first we develop the voltage regulator that can reuse the waste lead battery. And the pulse current is applied to the terminal of the waste lead acid battery. The voltage regulator is available principle of the pulse current which can reduce the sulfate to incipient material such as Pb and PbO2. Therefore the internal resistance of the lead acid battery is decreased, the performance of the lead acid battery is improved and the durability is prolonged. The second we develop the pulse charger using the voltage regulator. The pulse charger uses the switch mode of the forward convert method. The pulse charger maintain the constant voltage in state removing the lead acid battery and when it connected the pulse charger, it is converted the charge mode of the constant current immediately. It continues the rapid charge until the full state of the lead acid battery. After that the pulse charger is converted to the charge mode of constant voltage automatically, and then it continues the normal charge. The experiment results show that the effectiveness of the voltage regulator and pulse charger such as the good performance and the prolonged durability in lead acid battery of the small and large capacity.

• Journal of the Korea Computer Industry Society
• /
• v.3 no.9
• /
• pp.1177-1188
• /
• 2002

To classify real time Lead pin images in this paper, The image acquisition system was composed to C.C.D, image frame grabber(DT3153), P.C(PentiumIII). I proposed image processing algorithms. This algorithms were composed to real time monitoring, Lead Pin image acquisition, image noise deletion, object area detection, point detection and pattern classification algorithm. The raw images were acquired from Lead pin images using the system. The result images were obtained from raw images by image processing algorithms. In implemental result, The right recognition was 97 of 100 acceptable products, 95 of 100 defective products. The recognition rate was 96% for total 200 Lead Pins.

• Journal of environmental and Sanitary engineering
• /
• v.18 no.1
• /
• pp.30-40
• /
• 2003

The study subjects included the workers who were estimated to have been exposed in a low density of lead-laden glaze from pottery manufacturers. They were evaluated in terms of PbB and PbU as indices of lead concentration in the body, and Hb, Hct, ALAD, and FEP as indices of biochemical lead poisoning. Consequently, the study results revealed the relationship between each of indices and its effectiveness to indicate the degree of occupational lead exposure. 1. The mean of PbB was $22.85{\;}{\mu}g/d{\ell}$(range; $4.2~44.7{\;}{\mu}g/d{\ell}$) and PbU $45.69{\mu}g/d{\ell}$(range; $6.7~87.5{\mu}g/d{\ell}$), to indicate the level of lead exposure in the subjects. 2. While there was a high, linear correlation between PbB, PbU and FEP (r=0.835, r=0.855, respectively), a low correlation existed between PbB and ALAD(r=-0.240). 3. While there was a high, linear correlation between PbU and FEP(r=0.825), a low correlation existed between PbU and ALAD(r=-0.352). The above results suggest that FEP can be used as a highly useful biochemical index of lead poisoning, based on its high correlation with PbB and PbU indicating lead concentration in the body.

• Journal of Korean Society on Water Environment
• /
• v.18 no.4
• /
• pp.395-400
• /
• 2002

Lead is one of the most toxic metal and is detectable in practically all phases of environment and in all biological system. Transport, industrial and domestic waste products are the main sources of this pollutant. Ingested lead is rapidly absorbed and widely distributed throughout the body, causing extensive tissue damage. In this study, we chose the freshwater decapods Maceobrachium nipponnese as a sensitive indicator organism for environmental pollution. In order to investigate the possibility in use of $Na^+/K^+ATPase$ activity as a biomarker of lead pollution, we tested the acute toxicity of lead to Maceobrachium nipponnese. The $LC_{50}(96hr)$ value for lead in Maceobrachium nipponnese was found to be $446{\mu}g/L$ with the 95% confidence limits. The lead exposure group at $LC_{50}$ showed a significant $Na^+/K^+ATPase$ inhibition, depending on the exposure time. Comparision of several concentrations of lead revealed that the $Na^+/K^+ATPase$ activity in Maceobrachium nipponnese was significantly decreased in a concentration dependent manner. These results suggest that $Na^+/K^+ATPase$ activity in Maceobrachium nipponnese may possibly be used as a biomarker of lead pollution in aquatic ecosystem.

• Journal of Fisheries and Marine Sciences Education
• /
• v.22 no.4
• /
• pp.501-507
• /
• 2010

The ceramic contained paint was made to replace the lead sinker for gill-net with coated lead sinker. The ceramic contained paints were coated in various conditions on the lead sinker with 19g of weight and the optimal coating condition was studied. The adaptability of the coated lead sinker was checked through the anti durability test and fishing operation with gill-net. The case of "Main material 70 wt% + Urethane thinner 30 wt% (Main material 700 $m{\ell}$ + Thinner 300 $m{\ell}$)" showed the best in the coating characteristics depending on the combination ratio of the ceramic paint contained. The coated lead sinker dried at $100^{\circ}C$ inside oven was superior to the drying in the room temperature in its surface glossiness and anti durability and faster drying time than the one dried in normal temperature. The quadruple layers of coating on lead sinker with 4 times of dipping and drying application showed the super anti durability in the coating characteristics depending on the frequency of dipping. When press is applied to the coated lead sinker, the coated layer is not detached from the sinker. In addition, the coated lead sinker was not damaged or peeled at the fishing operation about 2 months in various depths within 50m and by the materials at the bottom (sand, stone and gravel stone) and it was in good condition.

• The Korean Journal of Pain
• /
• v.20 no.2
• /
• pp.186-189
• /
• 2007

The most important factors for successful stimulation of the spinal cord are strict patient selection and proper lead position. To ensure proper lead position, paresthesia produced by the stimulator should cover all of the areas in which pain is occurring. Until recently, only the quadripolar electrode lead has been used in for spinal cord stimulation in Korea, however, the 8 electrode lead was recently introduced to offer greater programming options and enhance the precision with which paresthesias is delivered to the desired sites. In addition, because the 8-electrode lead has a longer electrode span, it provides greater dermatomal coverage of up to 2 vertebral segments. Furthermore, the 8-electrode lead allows electronic repositioning of the stimulation to accommodate changing pain patterns, thereby reducing the need for lead revisions due to lead migration. Here, we present a case in which complex regional pain syndrome type I was successfully managed using an 8-electrode lead to induce spinal cord stimulation.

• Journal of radiological science and technology
• /
• v.41 no.6
• /
• pp.611-616
• /
• 2018

Lead apron is harmful to the human body because it is made at heavy metals, and when worn for long periods of time, it causes pain. Therefore, this paper intended to improve the defects of lead apron by using new material shields. For the comparative evaluation of lead and new material shieldes, the shielding rate and weight were measured and tested based on lead 0.5 mmPb. The rate of shielding was 97% based on lead at 0.5 mm thickness, while The new material shield T3 showed similar shielding rates as lead in 8 layers, and in T2 these values were measured in 11 layers. In addition, similar shielding rate was measured in 12 layers at B2, and 8 layers in BF, and 4 layers in $BF_2$. Comparing the weight of cases when commercialized with apron, T3, T2 and B2 were heavier than lead apron. But BF, $BF_2$ were lighter than the lead apron. Based on the results of the experiment, T3 and T2 can be used as an alternative to lead if human or environmental hazards are considered a priority. However, BF and $BF_2$ should be used if the reduction of external exposure is considered a priority.

• The Korean Journal of Pharmacology
• /
• v.17 no.1 s.28
• /
• pp.17-25
• /
• 1981

No evidence has accumulated that lead compound is an essential component for biological function in animals. Lead is absorbed primarily through the epithelial mucosal cells in duodenum and the absorption can be enhanced by the substances which bind lead and increase its solubility. Iron, zinc and calcium ions, however, decrease the absorption of lead without affecting its solubility, probably by competing for shared absorptive receptors in the intestinal mucosa. Therefore, the absorption of lead is increased in iron deficient animals. Lead shows a strong affinity for ligands such as phosphate, cysteinyl and histidyl side chains of proteins, pterins and porphyrins. Hence lead can act on various active sites of enzymes, inhibiting the enzymes which has functional sulfhydryl groups. lead inhibits the activity of ${\delta}$-aminolevulinic acid dehydratase for the biosynthesis of hemoproteins and cytochrome, which catalyzed the synthesis of monopyrrole prophobilinogen from ${\delta}$-aminolevulinic acid. Accordingly lead decrease hepatic cytochrome p-450 content, resulting an inhibition of the activity of demethylase and hydroxylase in liver. Little informations are available on the effect of lead on digestive system although the catastrophic effects of lead intoxication are well documented. The present study was, therefore, attempted to investigate the effect of lead on pancreaticobiliary secretion in rats. Albino rats of both sexes weighing $170{\sim}230g$ were used for this study. The animals were divided into one control and three treated groups, i.e., control (physiologic saline 1.5ml/kg i.p.), lead acetate $(l0{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and EDTA$(each\;10{\mu}mole/kg/day\;i.p.)$, $Pb(Ac)_2$ and $FeSO_4(each\;l0{\mu}mole/kg/day\;hp)$. The pancreatico-biliary juice was collected under urethane anesthesia, and activities of amylase and lipase were determined by employing Sumner's and Cherry and Crandall's methods. The summarized results are follows. 1) In the experiment for acute toxicity of lead acetate, 20% of mortality was observed in rat treated with lead acetate as well as inhibition of the activity of amylase in the juice at the 3 rd day of the treatment. 2) No increases in body weight were observed in rats treated with lead acetate, while in control group the significant increases were observed. However, the body weights of animals were increased in the group lead acetate plus EDTA or $FeSO_4$. 3) Lead acetate decreased significantly the volume of pancreatico-biliary juice whereas additional treatment of EDTA and $FeSO_4$ prevented it. 4) Total activity of amylase was markedly reduced due to lead acetate treatment, but no change was showed following additional treatment with EDTA and $FeSO_4$. 5) No changes in the cholate and lipase output were observed in rats treated with lead acetate as compared with that of control rats. 6) Increase in bilirubin output in rats treated with lead acetate was shown on the 2nd and 3rd weeks treatment. 7) In the case of in vitro experiment, lead acetate also markedly inhibited release of amylase from pancreatic fragment. 8) Histologic finding indicated that acini vacuolation was induced in the pancreatic tissue of rat treated with lead acete. From the above results, it might be concluded that lead acetate decreases the volume of pancreatico-biliary secretion and inhibits the amylase activity, by acting directly on pancreatic cells.