• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.77-85
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• 1992

Of the cadmium-tolerant 162 bacterial strains isolated from soils, river waters or active sludges of waste-water disposal plants in the Gyeongnam province a strain C1, which showed considerably higher growth rate in the agar plate containing 2000 ppm than any other strains isolated, was identified as a Pseudomonas putida or its similar strain when analyzed by taxonomical characteristics. Optimum pH and temperature for the growth of the P, putida were 7.0 and $30^{\circ}C$, respectively. This strain was resistant to antibiotics(ampicillin, chloramphenicol and streptomycin), and heavy metals(lithium, cupper, lead and zinc). This strain utilized salicylate, naphthalene or xylene as a sole carbon source. The rate of cadmium accumulation in P. putida cell was enhanced at low concentration of Cd in the growth media. The maximum cadmium absorption by this strain grown in 1 and l0ppm of Cd was respectively 78% and 60% 24 hrs after culture, but in 100 ppm Cd, 40% 48 hrs after culture. Addition of a non-ionic surfactant Triton X-100(0.1%) to the medium enhanced the accumulation of cadmium in the P. putida up to approximately 37%.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.3
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• pp.366-376
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• 1997

$CdGa_2Se_4$, epilayer of tetragonal type are grown on Si(100) substrate by hot wall epitaxy method. The source and substrate temperature is $580^{\circ}C$ and $420^{\circ}C$ respectively, and the thickness of the film is 3 $\mu \textrm{m}$. The crystallihe structure of epilayers were investigated by double crystal X-ray diffraction(DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility depending on temperature. From Hall data, the mobility was likely to be decreased by pizoelectric scattering in the temperature range 30 K to 200 K and by polar optical scattering in the temperature range 200 K to 293 K. In order to explore of photocurrent to darkcurrent (pc/dc), maximum allowable power dissipation (MAPD), spectral response and response time. The results indicated that for the samples annealed in Se vapor the photoconductive characteristics are best. Then we obtained the sensitivity of 0.98, the value of pc/dc of $9.62{\times}10^6$, the MAPD of 321 ㎽ and the rise and decay time of 9 ㎳ and 9.5 ㎳, respectively.

• The Korean Journal of Malacology
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• v.25 no.3
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• pp.213-222
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• 2009

In order to investigate contamination of heavy metal in seawater and cultured oyster, samples were collected November 2003 to July 2004 from 12 sites (13 sites for seawater) along the coast of Tongyeong, Korea. The mean concentrations of metal in oyster tissues were as follows: 0.09 (0.01-0.3) ${\mu}g/l$ for Cd, 0.47 (0.01-1.4) ${\mu}g/l$ for Cr, 0.59 (0.2-2.3) ${\mu}g/l$ for Ni, 1.02 (0.1-4.2) ${\mu}g/l$ for Pb and 0.48 (0.01-3.9) ${\mu}g/l$ for Hg in the seawater, whereas 2.45 (0-5.47) mg/kgDW for Cd, 3.63 (0.10-12.91) mg/kgDW for Cr, 3.2 (0.01-15.73) mg/kgDW for Ni, 3.51 (0.01-6.47) mg/kgDW for Pb and 0.39 (0.004-0.74) mg/kgDW for Hg, respectively. Most metal concentration values were below the permissible range for the related regulations. Mean bioconcentration factors (BCF) for each metal were as follows: 38,964 (1,771-207, 171) for Cd, 9,583 (1,231-80, 162) for Cr, 191 (3-20, 980) for Ni, 1,416 (245-5, 207) for Pb and 180 (5-716) for Hg, respectively. The BCF values from this study corresponded to the transitional phase from the pristine to the contaminated waters. Notably, Cd showed the highest BCF, which suggest that the Pacific oyster could be utilized as a useful biomarker for Cd contamination in sea water. The multidimensional scaling analysis suggested that the metal contaminants are mainly originated from combustion of fossil fuel and accumulated to oyster through food web.

• Toxicological Research
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• v.26 no.2
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• pp.157-162
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• 2010

In this study, we investigated the atmospheric heavy metal concentrations in the particulate matter inside the subway stations of Seoul. In particular, we examined the correlation between the heavy metals and studied the effect of the heavy metals on cell proliferation. In six selected subway stations in Seoul, particulate matter was captured at the platforms and 11 types of heavy metals were analyzed. The results showed that the mean concentration of iron was the highest out of the heavy metals in particulate matter, followed by copper, potassium, calcium, zinc, nickel, sodium, manganese, magnesium, chromium and cadmium in that order. The correlation analysis showed that the correlations between the heavy metals was highest in the following order: (Cu vs Zn), (Ca vs Na), (Ca vs Mn), (Ni vs Cr), (Na vs Mn), (Cr vs Cd), (Zn vs Cd), (Cu vs Cd), (Ni vs Cd), (Cu vs Ni), (K vs Zn), (Cu vs K), (Cu vs Cr), (K vs Cd), (Zn vs Cr), (K vs Ni), (Zn vs Ni), (K vs Cr), and (Fe vs Cu). The correlation coefficient between zinc and copper was 0.937, indicating the highest correlation. Copper, zinc, nickel, chromium and cadmium, which are generated from artificial sources in general, showed correlations with many of the other metals and the correlation coefficients were also relatively high. The effect of the heavy metals on cell proliferation was also investigated in this study. Cultured cell was exposed to 10 mg/l or 100 mg/l of iron, copper, calcium, zinc, nickel, manganese, magnesium, chromium and cadmium for 24 hours. The cell proliferation in all the heavy metal-treated groups was not inhibited at 10 mg/l of the heavy metal concentration. The only exception to this was with the cadmium-treated group which showed a strong cell proliferation inhibition. This study provides the fundamental data for the understanding of simultaneous heavy metal exposure tendency at the time of particulate matter exposure in subway stations and the identification of heavy metal sources. Moreover, this study can be used as the fundamental data for the cell toxicity study of the subway-oriented heavy metal-containing particulate matter.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.523-526
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• 2000

A novel cell surface display system was developed by employing the Escherichia coli outer membrane protein C (OmpC) as an anchoring motif. Poly-histidine (poly-His) peptides of 19, 32, 45, 84, and 162 amino acids (aa) could be successfully displayed by inserting them into the seventh exposed loop(L7) of OmpC. Recombinant cells displaying poly-His of 19, 32, 45, and 84 aa could absorb 18.9, 23.9, 26.1, and 32.0 ${\mu}mol$ of $Cd^{2+}$ per gram cell dry weight, respectively and therefore, would be useful as the biosorbents of heavy metals.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.03a
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• pp.162-163
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• 2009

Colorimetric chemosensors are now considered as one of the most effective analytical method used in the environmental monitoring. In this study, 10 new direct dyes were synthesized to be used as colorimetric chemosensor. When metal ions such as $Al^{3+},\;Ca^{2+},\;Cd^{2+},\;Cr^{3+},\;Cu^{2+},\;Fe^{2+},\;Fe^{3+},\;Hg{^2+},\;Li^+,\;Mg^{2+},\;Na^+,\;Ni^{2+},\;Pb^{2+}\;and\;Zn^{2+}$ were added to the solutions of new dyes, the colors of the solutions were changed and can be easily detected by eyes without any expensive equipments. Some metal ions were coordinated to the new direct dyes forming complex. The experimental data and conclusions were rationalized by UV-VIS spectroscopy.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.157-162
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• 2003

This study is analysis on the heat transfer of exhaust gas into the muffler at passenger Car. Numerical analysis with Computational fluid Dynamics(CFD) was carried out to investigate exhaust gas flow. The STAR-CD S/W used for the three dimensional steady state CFD analysis in a muffler. The Navier-Stokes Equation is solved with the SIMPLE method in a general cartesian coordinates system. Result of numerical simulation; Inlet and outlet temperature shown about ${\Delta}T=239K$, 216K, 202K at in the muffler. Heat transfer was progressed quickly by atmospheric temperature of muffler external at in the near wall.

• Journal of environmental and Sanitary engineering
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• v.22 no.3
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• pp.1-12
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• 2007

This study was investigated hazardous substances in agricultural products of baggage by Incheon Port from chinese. We tested 293 kinds of dried red pepper, cereal, sesame, bean, nut, herbal medicine and sesame oil for pesticides residue, mold, tar color, sudan I, II, III, IV, aflatoxin, Pb, Cd, Hg, As and sulfur dioxide residues. Violated samples over standard limits by Korean Food and Drug Administration (KFDA) were 76 dried red pepper over the number of mold and 1 dried red pepper detected red 102 tar color and 1 dried red pepper over the number of mold and detected red 102 tar color simultaneously. And 2 rice, 1 sticky rice, 1 adlay and 1 millet were over lead. Violated herbal medicine were 2 Zizyphi Furctus and 2 Zingiberis Rhizoma over sulfur dioxide residue and 1 Zingiberis Rhizoma over sulfur dioxide residue and cadmium simultaneously. The contents of heavy metals in cereal were as follow; $Pb\;0.000{\sim}0.740mg/kg(0.191{\pm}0.209),\;Cd\;0.000{\sim}0.108mg/kg(0.007{\pm}0.020),\;Hg\;0.000{\sim}4.201mg/kg(0.162{\pm}0.319)$. The contents of heavy metals in herbal medicine were as follow; $Pb\;0.000{\sim}2.480mg/kg(1.130{\pm}0.730),\;Cd\;0.000{\sim}0.761mg/kg(0.044{\pm}0.122),\;Hg\;0.000{\sim}0.157mg/kg(0.022{\pm}0.033),\;As\;0.000{\sim}0.560mg/kg(0.040{\pm}0.082)$. Contents of $SO_2$ ranged $2.0{\sim}1459.4ppm(303.1{\pm}324.2)$.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.162-167
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• 2017

A Katsuobushi smoking machine was developed and evaluated to determine its benzo(a)pyrene reducing effect. The machine was equipped with two heaters for smoking and chamber heating. The smoke-generating system was equipped with a cadmium sulfide (CdS) smoke sensor, an on/off controller, and a rotating feeder with a smoke inlet. Raw bonito was steamed and then smoked under three smoke levels. After smoking at $45^{\circ}C$ for 108 h, the benzo(a)pyrene concentrations were 5.87, 7.83, and $11.41{\mu}g/kg$ at the low, middle, and high smoke levels, respectively. The benzo(a)pyrene concentrations after low-level smoking at 45, 65, and $85^{\circ}C$ for 108 h were 5.87, 4.82, and $3.27{\mu}g/kg$, respectively. Accordingly, the optimal conditions for benzo(a)pyrene reduction were a lower smoke level and higher smoking temperature. These optimal smoking conditions can be implemented with the newly developed machine, but is not possible using a conventional Katsuobushi smoking machine.

• IMMUNE NETWORK
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• v.23 no.4
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• pp.33.1-33.13
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• 2023

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been acknowledged as an effective mean of preventing infection and hospitalization. However, the emergence of highly transmissible SARS-CoV-2 variants of concern (VOCs) has led to substantial increase in infections among children and adolescents. Vaccine-induced immunity and longevity have not been well defined in this population. Therefore, we aimed to analyze humoral and cellular immune responses against ancestral and SARS-CoV-2 variants after two shots of the BNT162b2 vaccine in healthy adolescents. Although vaccination induced a robust increase of spike-specific binding Abs and neutralizing Abs against the ancestral and SARS-CoV-2 variants, the neutralizing activity against the Omicron variant was significantly low. On the contrary, vaccine-induced memory CD4⁺ T cells exhibited substantial responses against both ancestral and Omicron spike proteins. Notably, CD4⁺ T cell responses against both ancestral and Omicron strains were preserved at 3 months after two shots of the BNT162b2 vaccine without waning. Polyfunctionality of vaccine-induced memory T cells was also preserved in response to Omicron spike protein. The present findings characterize the protective immunity of vaccination for adolescents in the era of continuous emergence of variants/subvariants.