• Journal of Microbiology
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• v.33 no.3
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• pp.228-233
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• 1995

As S. epidermidis cell was fractionated into cell wall, cell membrane, and cytoplasm, the cell membrane proved to be the most efficient absorbent for lead ion. Utrasonication was effective, when the cells were treated during their exponential growth. The amount of the lead ion adsorbed in cell membrane decreased as hydrogen ion concentration of solution increased. Protein purified from the cell membrane showed higher adsorption capacity for the lead ion than peptidoglycan, teichoic acid from cell wall, or cell membrane lipid. Modification of carboxyl groups in the membrane protein with ethylenediamine and 1-ethyl-3-carbodiimide hydrochloride resulted in a considerable decrease of lead ion adsorption capability, suggesting that the main binding site for lead ion was the carboxyl groups of protein in cell membrane.

• YAKHAK HOEJI
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• v.19 no.1
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• pp.21-29
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• 1975

The activity of $\delta$-aminolevlinic acid dehydratase (ALAD) in red cell of rabbit inhibited by addition of $Pb(Ac)_{2}$(50mg/kg) to rabbit caused to diminish completely the ALAD activity in blood within shr. Pretreatment of ascorbic acid and methionine decreased the increment of $\delta$-aminolevulinic acid output in urine by lead poisoning.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.55-60
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• 1997

Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri which possessed the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewaters and mine wastewaters polluted with various heavy metals. The distribution of heavy metal in the cell components, and amino acid compositions, was investigated. The distribution of heavy metal in the cell fractions of each heavy metal-tolerant microorganism grown for 20 hours in the basal medium containing 100mg/l of each heavy metal was investigated. In the case of cadmium-tolerant P. putida, lead-tolerant P. aeruginosa and copper-tolerant P. stutzeri, approximately $50{\sim}60%,\;30{\sim}40%$ and $10{\sim}17%$ of each heavy metal absorbed were distributed to cell wall, cell membrane and cytoplasm fractions, respectively. In the case of zinc-tolerant P. chlororaphis, approximately 32%, 55% and 13% of zinc were distributed to cell wall, cell membrane and cytoplasm fractions, respectively. These results indicated that the cell wall was a major adsorbing fraction of cadmium, lead and copper, and the cell membrane was that of zinc. Total amino acid content per gram of the cell grown in the culture media with heavy metal was higher than that of the cell grown in the culture media without heavy metal, and the content of acidic amino acids, such as aspartic acid(Asp.+Asn.) and glutamic acid(Glu.+Gln.) was higher than that of basic amino acids, such as histidine, lysine and arginine.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.694-702
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• 2014

One of the most important devices in an underwater vessel is a propulsion system. It should be a quiet and efficient system for stealthy operations in the large mission area. Hence lead-acid battery system has been used to supply the energy to electric motor. Recent technological developments and improvements, such as polymer electrolyte membrane(PEM) fuel cell and lithium polymer battery and have created the potential to improve overall power and propulsion performance. An underwater vessel always starts their mission with a limited energy and is not easy to refuel. Therefore design of energy elements, such as fuel cell and battery, and their load distribution are important to increase the maximum operating time of underwater vessel. In this paper, the lead-acid battery/PEM fuel cell and lithium polymer battery/PEM fuel cell were suggested as propulsion system and their performances were analyzed by modeling and simulation using Matlab/Simulink. Each model concentrated on representing the characteristics of energy element depending on demand current. As a result the effect of load distribution between battery and fuel cell was evaluated and the operation time of each propulsion system was able to be estimated exactly.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.249.1-249.1
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• 2015

Quantum dots (QDs) are attracting growing attention for photovoltaic device applications because of their unique electronic, optical and physical properties. Lead sulfide (PbS) QDs are one of the most widely studied materials for the devices and known to have size-tunable properties. In this context, we investigated the relationship between the size of PbS QDs and two synthesizing conditions, a concentration of ligand, oleic acid in this work, and injection temperature. The inverted colloidal quantum dot solar cells based on the heterojunction of n-type zinc oxide layer and p-type PbS QDs were also fabricated. The size of the QDs and cell properties were observed to depend on both the QD synthesizing conditions, and hence the overall efficiency of the cell could vary even though the size of QDs used was same. The QD synthesizing conditions were finally optimized for the maximum cell efficiency.

• Journal of Periodontal and Implant Science
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• v.23 no.2
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• pp.228-242
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• 1993

Some therapeutic agents and medicaments may lead to pathologic changes in the gingival tissue, especially on the cultured human gingival fibroblasts. The purpose of this study was to investigate on the effect of diphenylhydantoin, retinoic acid to the human gingival fibroblast. Human gingival fibroblasts were cultured from the healthy gingiva of patients with orthodontic patients. Gingival fibroblasts were trypsinized and transferred to the wells of 96 well microtest plates. Next day, the medium was removed, fibroblasts were washed with HBSS, and the washed cells were cultured in growth medium added 5 or $10{\mu}g/ml$ of diphenylhydantoin, $10^{-5}M$, $10^{-6}M$ and $10^{-7}M$ of retinoic acid and glycyrrhetinic acid. The passage number of cultured fibroblasts were fifth and eighth. The cell morphology was examined by inverted microscope, the cell number was counted by hemocytometer, and cell activity was measured by the growth and proliferatiton assay using MTT assay. The fifth experiments were performed and statistical significance was measured by ANOVA. The cell morphology in the presence of retinoic acid was round irrespective of the presence of diphenylhydantoin and glycyrrhetinic acid(Fig 2-6). The proliferation of cells was not changed by diphenylhydantoin(Table 1). The cell activity showed the tendency to increase at the concentration of $10{\mu}$'/, of diphenylhydantoin (Table 2). The cell activity in the presence of retinoic acid glycyrrhetinic acid was decreased, and the increased cell activity by diphenylhydantoin was decreased by retinoic acid and glycyrrhetinic acid at the concentration of $10^{-7}M$(Table 3-5). These results suggested that the increased cell activity by diphenylhydantoin might be modulated by retinoic acid and glycyrrhetinic acid.

• Corrosion Science and Technology
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• v.2 no.1
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• pp.1-6
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• 2003

A comprehensive coverage of corrosion in batteries is rendered difficult by the wide choice of materials, environments and physical features as obtained in practical settings. Understanding of the complex processes that occur in these electrochemical systems gets clearer as new theoretical approaches backed by sophisticated analytical and characterization techniques continue to provide valuable insights which aid in controlling/mitigating wasteful corrosion reactions which affect battery shelf-life, cycle life, rate capability and capacity. In the light of the above, I limit myself to a discussion on corrosion aspects in representative system such as conventional Leclanche, lead-acid battery and magnesium batteries, and advanced lithium systems.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.622-634
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• 1993

Gingiva is remarkly sensitive to certain drugs. Especially, long term use of phentoin, dihydropyrydine (including nifedipine), cyclosporin and other drugs can be lead to pathologic changes in gingival tissue, especially in terms of proliferation of epithelium and connective tissue. Recent study in terms of proliferation of epithelium and connective tissue. Recent study is focused on the inhibition of drug-induced gingival hyperplasia by using medicaments. The purpose of this study was to investigate on the pharmacological effects of nifedipine, retinoic acid and glycyrrhetini acid to the activity in human gingival fibroblast. Human gingival fibroblasts were cultured from the healthy gingiva of orthodontic patients. Gingival fibroblasts were trypsinized and cultured in growth medium added $5{\mu}g/ml$ of nifedipine, $10^{+7}M$ of retinoic acid and glycyrrhetinic acid. The passage number of cultured fibroblasts were between fifth and eighth. The cell morphology was examined by inverted microscope and the cell acitivity was measured by the MTT assay. Nifedipine at the concentration of $5{\mu}g/ml$ was revealed significantly effective to increase the cell activity and lipopolysaccharide was cofactor to increase cell activity in the presence of nifedipine. However, retinoic acid was significantly effective on the globular change of cell morphology and loss of cell process regardless of the presence of nifedipine and LPS. Cell activity was significantly decreased by the glycyrrhetinic acid at the concentration of $10^-M$ regardless of the presence of nifedipine and LPS. These results suggested that the increased cell activity by nifedipine might be modulated by retinoic acid and glycyrrhetinic acid. Further study is needed to clarify on their toxicological effects during cellular modulation and mRNA expression change.

• Korean Journal of Veterinary Research
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• v.24 no.1
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• pp.24-30
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• 1984

The protective effects of high levels of dietary iron, copper, zinc or protein on lead toxicity were studied In chicks. Growth retardation, reduction of feed intake, anemia and accumulation of lead in the bone and kidney were observed in chicks fed a diet containing 500mg lead as chloride per kg of feed for 42 days. Early changes due to ingested lead were inhibition of red blood cell ${\delta}$-aminolevulinic acid dehydrase at all doses and no effect of iron, copper, zinc or protein addition were observed. Tibia lead accumulation was reduced in chicks receiving additional dietary iron or zinc compared to the lead only group but increased in chicks given supplementary protein. Decreased body weight gain was overcome by supplementary zinc or protein in chicks fed lead but not by supplementary iron. Overall the results of this study show that lead poisoning can be partly reduced by providing supplementary iron, zinc or protein, but the interaction of these element remained to be elucidated.

• Biomolecules & Therapeutics
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• v.29 no.5
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• pp.498-505
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• 2021

Amyotrophic lateral sclerosis (ALS) is a lethal neurological disorder characterized by the deterioration of motor neurons. The aim of this study was to investigate alteration of cationic amino acid transporter (CAT-1) activity in the transport of lysine and the pretreatment effect of lysine on pro-inflammatory states in an amyotrophic lateral sclerosis cell line. The mRNA expression of cationic amino acid transporter 1 was lower in NSC-34/hSOD1^G93A (MT) than the control cell line (WT), lysine transport is mediated by CAT-1 in NSC-34 cell lines. The uptake of [³H]L-lysine was Na⁺-independent, voltage-sensitive, and strongly inhibited by inhibitors and substrates of cationic amino acid transporter 1 (system y⁺). The transport process involved two saturable processes in both cell lines. In the MT cell line, at a high-affinity site, the affinity was 9.4-fold higher and capacity 24-fold lower than that in the WT; at a low-affinity site, the capacity was 2.3-fold lower than that in the WT cell line. Donepezil and verapamil competitively inhibited [³H]L-lysine uptake in the NSC-34 cell lines. Pretreatment with pro-inflammatory cytokines decreased the uptake of [³H]L-lysine and mRNA expression levels in both cell lines; however, the addition of L-lysine restored the transport activity in the MT cell lines. L-Lysine exhibited neuroprotective effects against pro-inflammatory states in the ALS disease model cell lines. In conclusion, studying the alteration in the expression of transporters and characteristics of lysine transport in ALS can lead to the development of new therapies for neurodegenerative diseases.