• Bulletin of the Korean Chemical Society
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• v.22 no.5
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• pp.463-466
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• 2001

The determination of Cd2+ and Cu2+ with ammonium pyrrolidinedithiocarbamate (APDC) in Tween 80 micellar media has been studied. The UV-visible spectrum of Cd(PDC)2 complex in Tween 80 media had more sensitivity tha n in chloroform. Although the UV-visible spectrum of the Cu(PDC)2 complex in Tween 80 media had somewhat less sensitivity than that in chloroform, absorbance data of Cu2+ were more reproducible in Tween 80 media. The Cd(PDC)2 and Cu(PDC)2 complexes were very stable at pH 7.0 for up to 100 minutes and could be quantitatively chelated if APDC were added to the sample solution more than 30 times the moles of Cd2+ and Cu2+ . The optimum concentration of Tween 80 was 0.1%. The calibration curves of Cd(PDC)2 and Cu(PDC)2 complexes with good linearity were obtained in 0.1% Tween 80 media. The detection limits of Cd2+ and Cu2+ were 0.0493 ㎍mL-1 and 0.0393 ㎍mL-1 , respectively. Recovery yields of Cd2+ and Cu2+ ions in the spiked real samples were almost 100%. Based on experimental results, this proposed method could be applied to the rapid and simple determination of Cd2+ and Cu2+ in real samples.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.23-36
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• 2006

Experimental leaching of tailings was performed as a function of times (1, 2, 4, 7, 14, 21 and 30 days) in the laboratory using reaction solutions equilibrated to three different pH set-points (pHs 1,3 and 5). The initial pHs of 5 and 3 stabilized at either 4.6-6.1 or 2.8-3.5 in 2 days and decrease gradually with time afterwards. The results of the leaching tests indicate that the significant increase in the sulfate concentrations and in acidity after 7 days of leaching results from the oxidation of sulfide minerals. There were no significant variations in the extractable Pb found in the leach solutions of pH 5 and 3 within the reaction time (1-30 days), while Zn, Cd and Cu concentrations tend to significantly increase with time. In tailings leaching at an initial pH=1, two trends were observed: i) The 'Zn-type' (Zn, Cd and Cu), with increasing concentrations between days 1 and 30, corresponding to the expected trend when continuous dissolution is the dominant process, ii) the 'Pb-type' (Pb), with decreasing concentrations over time, suggesting rapid dissolution of a Pb source followed by the precipitation of 'anglesite' in relation to the large increase in dissolved sulfates. The high sulfate concentrations were coupled with high concentrations of released Fe, Zn and Cd. Release of Zn and Cd and acidity from these leaching experiments can potentially pose adverse impact to surface and groundwater qualities in the surrounding environment. The kinetic problems could be the important factor which leads to increasing concentrations of trace metals in the runoff water.

• The Journal of Dong Guk Oriental Medicine
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• v.6 no.2
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• pp.99-107
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• 1998

Cyclosporin A(CsA) is a selective immunosuppressive agent that has been credited with improved survival of solid organ allografts. Lymph node of BALB/C mouse administered CsA immunohistochemically observed to understand immunosuppressive effects of CsA on T lymphocytes, IL-2 receptors, and natural killer NK cells in lymph node. CsA orally administered daily for 10days at the dose 45mg/kg/day/. The lymph node were obtained at day 3, 7, and 14 after CsA administration and embedded with paraffin, and then stained by following ABC method that used monoclonal antibody including L3T4(CD4), Ly2(CD8), IL-2R(CD25), and NK-1.1(CD56). There were little changes of reactive degree and number of helper T lymphocytes, cytotoxic T lymphocytes, IL-2 receptors, and NK cells at day 3 after CsA administration, but they began to decrease at day 7. These decrease were greatest at day 14. The helper T lymphocytes. cytotoxic T lymphocytes, IL-2 receptors, and NK cells distributed in paracortex and medullary sinus. These results indicated that the secretion of IL-2 began to decrease at day 7 after CsA administration and subsequently to suppress T lymphocytes and NK cell as components of cell-mediated immunity.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.2
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• pp.1-6
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• 2008

New devices with the structure of ITO/2-TNATA/NPB/TCTA/CBP:$7%Ir(ppy)_3$/BCP/SFC-137/LiF/Al were designed and fabricated to develop high efficiency green phosphorescent organic light emitting diodes and their electroluminescence properties were evaluated. Among the devices with different thicknesses of CBP in a range of $150{\AA}{\sim}350{\AA}$, the best luminance was obtained in the device with $300{\AA}$-thick CBP host. Nearly saturated current efficiencies indicates that the maximum efficiency value can be obtained with CBP thicknesses of $300{\AA}{\sim}350{\AA}$. The current density, luminance, and current efficiency of the PhOLED(phosphorescent organic light emitting diode) with $CBP(300{\AA}):7%Ir(ppy)_3-emissive$ layer at an applied voltage of 10V were $40mA/cm^2,\;10000cd/m^2$, and 25 cd/A, respectively. The maximum current efficiency was 40.5cd/A under the luminance of $160cd/m^2$. The peak wavelength and FWHM(full width at half maximum) in the electroluminescence spectral were 512nm and 60nm, respectively. The color coordinate was (0.28, 0.63) on the CIE (Commission Internationale de I'Eclairage) chart.

• Korean Journal of Veterinary Service
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• v.22 no.1
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• pp.1-7
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• 1999

This study was performed to investigate the contents of the heavy metals such as cadmium(Cd), copper(Cu), iron(Fe), lead(Pb) and zinc(Zn) in meat and meat products. For this experiment, each 20 samples of beef and pork were collected at slaughterhouse in Seoul areas and 45 samples of meat products(ham, sausage, processed meat and seasoned meat) were purchased from commercial food markets. The contents of the heavy metals was determined by atomic absorption spectrophotometry from Jan. to Nov. In 1998. The results obtained were summarized as follows ; 1. In Korean native beef, mean values of the heavy metals(mg/kg) were Pb : 0.14$\pm$0.10, Cd : 0.07$\pm$0.02, Cu : 1.73$\pm$0.95, Zn : 42.82$\pm$8.17 and Fe : 67.43$\pm$24.18, respectively. 2. In imported beef, mean values of the heavy metals(mg/kg) were Pb : 0.03$\pm$0.08, Cd : 0.06$\pm$0.02, Cu : 1.41$\pm$0.62, Zn : 42.93$\pm$4.95 and Fe : 40.06$\pm$12.77, respectively. 3. In pork, mean values of the heavy metals(mg/kg) were Pb : not detected, Cd : 0.09$\pm$0.02, Cu : 1.08$\pm$0.23, Zn : 19.49$\pm$6.02 and Fe : 30.21$\pm$10.51, respectively. 4. In ham, mean values of the heavy metals(mg/kg) were Pb : trace, Cd : trace, Cu . 1.19$\pm$0.46, Zn : 13.58$\pm$4.99 and Fe : 31.43$\pm$11.74, respectively. 5. In sausage, mean values of the heavy metals(mg/kg) were Pb : 0.15$\pm$0.34, Cd : 0.08$\pm$0.05, Cu : 1.15$\pm$0.46, Zn : 13.70$\pm$7.13 and Fe . 27.28$\pm$15.05, respectively. 6. In processed meat, mean values of the heavy metals(mg/kg) were Pb : 0.08$\pm$0.13, Cd : 0.09$\pm$0.04, Cu : 1.28$\pm$0.60, Zn : 14.72$\pm$7.09 and Fe : 24.04$\pm$10.33, respectively. 7 In seasoned meat, mean values of the heavy metals(mg/kg) were Pb : 1.05$\pm$2.21, Cd : 0.13$\pm$0.03, Cu : 1.06$\pm$0.16, Zn : 17.53$\pm$8.72 and Fe : 26.76$\pm$9.02, respectively.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.27 no.1
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• pp.26-36
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• 2024

Purpose: We investigated the role of CD8⁺T cells as host immune factors in pediatric patients with Helicobacter pylori gastritis. Methods: Gastric mucosal tissue and blood samples were collected from 39 children, including 11 children with H. pylori infection and 28 children as controls. Anti-CD8 and anti-T-bet antibodies were used for immunohistochemistry of the gastric mucosa. For the cell surface and intracellular staining, peripheral blood mononuclear cells were stained with anti-IL7Rα, anti-CX3CR1, anti-CD8, anti-T-bet, and anti-IFN-γ antibodies. Cytokines of sera such as tumor necrosis factor alpha (TNF-α) and CX3CL1 were analyzed using enzyme- linked immunosorbent assay (ELISA). Results: In the immunohistochemistry of gastric mucosa, the frequency of CD8⁺ and T-bet⁺ T cells cells was higher in the H. pylori-positive group than in the control group (26.9± 7.8% vs. 16.9±3.3%, p<0.001; 5.0±2.5% vs. 2.2±0.7%, p=0.001). Between the control and H. pylori-positive groups, the frequency of IL-7Rα^lowCX3CR1⁺ CD8⁺ and T-bet⁺ INF-γ⁺ CD8⁺ T cells were not significantly different between surface and intracellular staining, respectively (40.4±24.0% vs. 38.2±17.8%, p=0.914; 40.4±24.0% vs. 38.2±17.8%, p=0.914). In the ELISA, no significant differences in TNF-α and CX3CL1 concentrations were observed between the control and H. pylori-positive groups (34.3±12.1 pg/mL vs. 47.0±22.6 pg/mL, p=0.114/0.5± 0.1 pg/mL vs. 0.5±0.1 pg/mL, p=0.188). Conclusion: CD8⁺ T and Th1 cells, which secrete IFN-γ, might play important roles in the mucosal immunity of the stomach in children with H. pylori infection.

• Journal of Environmental Science International
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• v.4 no.2
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• pp.223-232
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• 1995

New two macrocyclic compounds using as carriers of liquid emulsion menbrame, have been synthesized. These reuslts provide evidance for the usefulness of the theory in designing the systems. The efficiency of selective transport for heavy metal ions have been discussed from the membrane systems that make use of $SCN^-$,<>,$I^-$,CN- and $Cl^-$ ion as co-anions in source phase and make use of $S_2O_3^{2-}$ and $P_2O_7^{4-}$ ion as receiving phase, respectively. The transport rate of M(II) was highest when a maximum amount of the M(II) in the source phase was present as$Cd(SCN)_2$$(P[SCN^-]= 0.40M)$, $Hg(SCN)_2([SCN^-]=0.40M)$ and Pd(CN)$([CN^-]= 0.40M)$. The Cd(II) and Pb(II) over each competitive cations were well transprted with 0.3M-S2032- and 0.3M-P2O74-, respectively in the receiving phase. Results of this study indicate that two criteria must be met in order to have effective macrocycle-mediated transport in these emulsion system. First one must effective extraction of the $M^{n+}$ into the toluene systems. The effectiveness of this extraction is the greatest if locK for $M^{n+}$macrocycle interaction is large and if the macrocycle is very insoluble in the aqueous phase. Second, the ratio of the locK values (or Mn+-receiving phase ($S_2O_3^{2-}$- or $P_2O_7^{4-}$) to $M^{n+}$-macrocycle (($L_1$이나 $L_2$) interaction must be large enough to ensure quantitative stripping of Mn+(($Cd^{2+}$,$Pb^{2+}$)at the toluene receiving Phase interface. $L_1$(3.5-benzo-10,13,18,21-tetraoxa-1,7,diazabicyclo(8,5,5) eicosan) forms a stable ($Cd^{2+}$ and >,$Pb^{2+}$ complexes and $L_1$ is very insoluble in water and its $Cd^{2+}$ and >,$Pb^{2+}$ complex is considerably less stable than $Cd^{2+}$-(S2O3)22- and $Pd^{2+}-P_2O_7^{4-}$ complexes. On the other hand, the stability of the $Hg^{2+}$)+-$L_1$( complex exceed that of the $Hg^{2+}$- (S2O3)22- and Hg2+-P2O74-, and the distribution coefficient of $L_2$(5,8,15,18,23,26-hexaoxa-1,12- diazabicyclo-(10,8,8) octacosane) is much smaller than that of $L_1$. Therefore, the partitioning of Lr is favored by the aqueous receiving Phase, and little heavy metal ions transport is seen despite the large logK for $Hg^{2+}$+-$L_1$ and $Mn^+$($Cd^{2+}$+, $Pb^{2+}$+ and $Hg^{2+}$)-$L_2$ interactions. Key Words : macrocycles, transport, heavy metal, co-anion, source phase, receiveing, complex separation, interaction, destribution coefficient.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.310-316
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• 2002

Extracellular cyclodextrin glucanotransferase (CGTase) from Paenibacillus sp. JK-12 was purified through sev-eral purification steps consisting of ammonium sulfate precipitation and chromatographies on DEAE-sephadex A-50 and Mono QIM HR5/5. The purified CGTase exhibited a single band on SDS-PAGE and was estimated to be approximately 82 kDa. The isoelectric point of the enzyme was 7.2 as determined by isoelectric focusing. The CGTase from Paenibacillus sp. JK-12 had a transglucosylation activity at the C-2 position of L-ascorbic acid. The optimum pH and temperature for the CGTase activity were 8.0 and 5$0^{\circ}C$, respectively. The enzyme activity was stable from pH 6.0 to 9.() and at temperatures up to 55$^{\circ}C$ at pB 8.0, having 80% residual activity. The activity of the CGTase was strongly resistant to metals such as A $g^{+}$ and $Ba^{2+}$ but slightly inhibited by H $g^{+}$, N $i^{2+}$ and $Mg^{2+}$. The enzymeproduced $\alpha$ -cyclodextrin ($\alpha$-CD) and $\beta$-CD as the main products from starch, but not ${\gamma}$-CD.X>-CD.

• Journal of Environmental Science International
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• v.15 no.6
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• pp.503-511
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• 2006

Airborne particles collected from a heavily industrialized site were analyzed by chemical speciation of seven trace metals: Pb, Cd, Cr, Cu, Ni, Zn, and As. The average concentrations were as follows: $Zn,\;502.0{\pm}230.7;\;Pb,\;176.5{\pm}310.9;\;Cu,\;111.9{\pm}82.7;\;As,\;38.0{\pm}31.0;\;Cr,\;21.5{\pm}24.4;\;Cd,\;20.8{\pm}17.4;\;and\;Ni,\;11.4{\pm}8.4\;ng/m^3$. The median enrichment factor (EF) values of Cd (7,280), As (1,030), Cu (215), Zn (214), and Pb (143), with respect to iron, were much larger than 100. We observed that Cd was found in the soluble and exchange- able form (56.9%), and that Pb and Cr were found in carbonates, oxides and the reducible form (69.8% and 61.1%, respectively). These two forms, which are the most easily absorbed into human body tissue, predominated in most of the trace metals investigated in this study.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3611-3616
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• 2010

Five new 4- or 8-substituted-7-hydroxycoumarin derivatives (1-5) were synthesized as fluorescent sensors for metal ions. Fluorescent changes and selectivity for metal ions were compared based on the introduction of different ligands and/or testing with different substitution positions of 7-hydroxycoumarin in aqueous solution. Especially, probes 2, 3 and 5 displayed large fluorescence enhancements with $Zn^{2+}$ and $Cd^{2+}$. Probes 2 and 3 showed moderate selectivity for $Zn^{2+}$ over $Cd^{2+}$. On the other hand, probe 4 showed large fluorescence quenching effects upon the addition of $Ag^+$ and $Hg^{2+}$.