• Title/Summary/Keyword: Cd

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The effects of zeatin on Cd2+ -induced physiological toxicities in Commelina communis L (Zeatin이 Cd2+에 의한 닭의장풀의 생리적 독성에 미치는 영향)

  • Lee Joon Sang
    • Journal of Environmental Science International
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    • v.14 no.3
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    • pp.345-350
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    • 2005
  • Three-week old Commelina communis was transferred and grown in Hoagland solution containing $100{\mu}M\;Cd^{2+},\;100{\mu}M\;Cd^{2+}+100{\mu}M\;kinetin,\;100{\mu}M\;Cd^{2+}+100{\mu}M\;zeatin\;and\;100{\mu}M\;Cd^{2+},\;200{\mu}M$ zeatin for 7 days, and then a number of physiological activities were investigated. In control, the length of the stem of plants was increased to 4.7cm, but in $Cd^{2+},\;Cd^{2+}+kinetin,\; Cd^{2+}+100{\mu}M\;zeatin\;and\;Cd^{2+}+200{\mu}M$ zeatin treatments, the growth of plants were increased to 1.5cm, 2.1cm, 3.9cm and 4.3 em, respectively. In the treatments of $Cd^{2+},\;Cd^{2+}+kinetin,\;Cd^{2+}+100{\mu}M\;zeatin\;and\; Cd^{2+}+200{\mu}M$ zeatin, total chlorophyll contents were reduced to $26\%,\;24\%,\;15\%\;and\;3\%$, respectively, on the contrast to the control. In chlorophyll fluorescence experiments, Fv/Fm ratios were also reduced to $44\%,\;21\%,\;17\%\;and\;5\%$ in the light intensity of $2100{\mu}Mmole\;E\;m^{-2}s^{-1}\;by\;Cd^{2+},\;Cd^{2+}+kinetin,\;Cd^{2+}+$100{\mu}M\;zeatin\;and\;Cd^{2+}+200{\mu}M$ zeatin treatments on the contrast to the control. Water stresses were increased to 2.6, 1.7 and 1.2 times by $Cd^{2+},\; Cd^{2+}+kinetin\;and\;Cd^{2+}+{\mu}M$ zeatin. On the other hand, combination of $Cd^{2+}+200{\mu}M$ zeatin reduced water stress to $0.12\%$. In $Cd^{2+}$ accumulation experiments $Cd^{2+}$transports were inhibited to $33\%\; 48\%\;and\;70\%\;by\;Cd^{2+}+kinetin,\;Cd^{2+}+100{\mu}M\;zeatin\;and\;Cd^{2+}+200{\mu}M$ zeatin. Therefore, it could be concluded that zeatin clearly reduced the toxicities of $Cd^{2+}$ by reducing the absorption of $Cd^{2+}$.

Characteristics of MOVPE Grown HgCdTe on GaAs and CdZnTe Substrates (GaAs 및 CdZnTe기판위에 MOVPE 법으로 성장된 HgCdTe 박막의 특성)

  • 김진상;서상희
    • Korean Journal of Crystallography
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    • v.12 no.3
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    • pp.171-176
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    • 2001
  • HgCdTe films were grown on the (100). (111), (211) CdZnTe, and (100) GaAs substrates by metal organic chemical vapor epitaxy. We have investigated the surface morphology, electrical properties, crystalline qualities, and composition of HgCdTe with substrates orientation. Three dimensional facet growth was occurred on (111) CdZnTe substrate. The crystalline quality of HgCdTe on (100) CdZnTe was superior to that of HgCdTe on (100) GaAs. FWHM values of double crystal x-ray diffraction of HgCdTe on (100) CdZnTe and (100) GaAs were 55 and 125arcsec, respectively. HgCdTe on GaAs substrate showed n-type conductivity with high mobility, however, HgCdTe on CdZnTe showed p-type conductivity with carrier concentration of higher than 10/sup 16/㎤.

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Cross-linking of CD80 and CD86 Diminishes Expression of CD54 on EBV-transformed B Cells through Inactivation of RhoA and Ras

  • Park, Ga-Bin;Kim, Yeong-Seok;Song, Hyun-Keun;Kim, Seong-Han;Park, Dong-Man;Lee, Wang-Jae;Hur, Dae-Young
    • IMMUNE NETWORK
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    • v.11 no.6
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    • pp.390-398
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    • 2011
  • Background: Epstein Barr virus (EBV) infected B cells are transformed into lymphoblastoid cell lines. Some researchers suggested some a few similarities between this process and carcinogenesis. We observed the expression of CD80 and CD86, co-stimulatory molecules on EBV-transformed B cells and changes of CD54 expression after stimulation of CD80 and CD86. Methods: CD80 and CD86 were stimulated using anti-CD80 and anti-CD86 monoclonal antibodies. To assess apoptosis and surface protein expression, flow cytometric analysis was performed. Intracellular signal molecules were evaluated by RT-PCR and immunoblot. Morphology and localization of proteins were examined using inverted or confocal microscope. Results: Cross-linking of CD80 and CD86 induced apoptosis and interfered with proliferation of EBV-transformed B cells, and dispersion of clumped cells. We also examined that their stimulation induced ROS accumulation and reduced CD54 expression. Interestingly, we observed that CD80 and CD86 diminished the expression of CD54 in different methods. Both CD80 and CD86 downregulated activation of focal adhesion kinase. CD80 stimulus inhibited CD54 expression through mainly RhoA inactivation, while CD86 down-regulated Ras and JNK phosphorylation. Conclusion: These results suggest that co-stimulatory CD80 and CD86 molecules, expressed EBV-transformed B cells, may play a role in apoptosis and cell adhesion.

Kinetic Study of Cadmium Adsorption by Sewage Sludge (하수오니에 의한 Cd 흡착의 속도론적 연구)

  • Lee, Sang-Mo;Goh, Tee-Boon
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.1
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    • pp.32-39
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    • 2000
  • To investigate the adsorption-desorption reaction of Cd by sewage sludge, the adsorption of Cd from $Cd(NO_3)_2$ solutions of concentrations ranging from 5 to $50{\mu}g\;Cd\;mL^{-1}$ by sewage sludge was examined for reaction periods up to 48 hours. The amount of Cd adsorbed as a function of time was measured. The adsorption between Cd in solution and the solid phase could be described by two stages. The initial adsorption of Cd was very rapid, that is, approximately 95% of the added Cd was removed from solution within the first 30 minutes. Further, the greater the concentration of Cd added, the greater was the amount of Cd adsorbed. After the rapid initial decrease of Cd, a slower decline in the Cd concentration resulted which followed first order reversible kinetics. The equilibrium concentrations for the reactions, as well as the time period for the equilibrium reactions were dependent on the initial Cd concentrations. If equilibrium is reached, the amount of Cd remaining in solution is greater when the amount adsorbed is higher, although the percentage of Cd in solution is constant relative to the initial concentration of Cd. Some of the adsorbed Cd was released back to solution since the concentration of Cd after 48 hours was higher than the equilibrium concentration of Cd. However, despite the increased amount of Cd measured, the overall net reaction was a significant adsorption of Cd from solution by sewage sludge.

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CD43 Expression Regulated by IL-12 Signaling Is Associated with Survival of CD8 T Cells

  • Lee, Jee-Boong;Chang, Jun
    • IMMUNE NETWORK
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    • v.10 no.5
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    • pp.153-163
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    • 2010
  • Background: In addition to TCR and costimulatory signals, cytokine signals are required for the differentiation of activated CD8 T cells into memory T cells and their survival. Previously, we have shown that IL-12 priming during initial antigenic stimulation significantly enhanced the survival of activated CD8 T cells and increased the memory cell population. In the present study, we analyzed the mechanisms by which IL-12 priming contributes to activation and survival of CD8 T cells. Methods: We observed dramatically decreased expression of CD43 in activated CD8 T cells by IL-12 priming. We purified $CD43^{lo}$ and $CD43^{hi}$ cells after IL-12 priming and analyzed the function and survival of each population both in vivo and in vitro. Results: Compared to $CD43^{hi}$ effector cells, $CD43^{lo}$ effector CD8 T cells exhibited reduced cytolytic activity and lower granzyme B expression but showed increased survival. $CD43^{lo}$ effector CD8 T cells also showed increased in vivo expansion after adoptive transfer and antigen challenge. The enhanced survival of $CD43^{lo}$ CD8 T cells was also partly associated with CD62L expression. Conclusion: We suggest that CD43 expression regulated by IL-12 priming plays an important role in differentiation and survival of CD8 T cells.

Spectral Response of the n-CdS/n-CdTe/p-CdTe Solar Cells (n-Cds/n-CdTe/p-CdTe 태양전지의 분광반응도)

  • Im, H.B.;Kim, S.J.
    • Proceedings of the KIEE Conference
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    • 1987.11a
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    • pp.248-250
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    • 1987
  • Transparent CdS films with low electrical restivity on glass substrates were prepared by coating a CdS slurry which contained 10 wt.% $CdCl_2$, and sintering in a nitrogen atmosphere at $600^{\circ}C$ for 2hr. All-polycrystalline CdS/CdTe solar cells were fabricated by coating CdTe slurries, which contained 1.0 or 4.5 wt.% $CdCl_2$, on the sintered CdS films and sintering at $700^{\circ}C$ for various periods of sintering. The spectral responses of the sintered CdS/CdTe solar cells were measured and compared with theoretically calculated quantum efficiency. The spectral responses of the sintered CdS/CdTe solar cells in the short-wavelength region decreases with-increasing sintering time. The poor response in this region is attributed to the existence of the Cd-S-Te solid solution in the compositional junction. The decrease in the maximum response in the long-wavelength region as the sintering exceeds certain time appears to be caused by the increase in the depth of the buried homo junction and by the increase in the series resistance. The $CdCl_2$ in the CdTe layer during sintering enchances the interdiffusion of S, Te or donor impurities across the metallurgical Junction causing the formation of deeper n-p junction in the CdTe layer.

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Photovoltaic Properties of Sintered CdS/CdTe Solar Cell (소결체 ITO/CdS/CdTe 태양전지의 광전압특성)

  • 김동섭;조은철;안병태;임호빈
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.11a
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    • pp.216-220
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    • 1994
  • Polycrystalline CdS films have been prepared by coating a slurry, which consisted of CdS, 11w% CdCl$_2$ and appropriate amount of propylene glycol, on glass substrate and glass substrate coated with indium tin oxide(ITO) followed by sintering in a nitrogen atmosphere. CdTe slurries consisting of Te powder and Cd powder were coated on the sintered CdS films and ITO/CdS films and were sintered in nitrogen to prepare sintered CdS/CdTe and ITO/CdS/CdTe solar cells. The value of fill factor increased due to low series resistance and open circuit voltage decreased due to low shunt resistance in the ITO/CdS/CdTe solar cells.

CD137-CD137 Ligand Interactions in Inflammation

  • Kwon, Byung-Suk
    • IMMUNE NETWORK
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    • v.9 no.3
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    • pp.84-89
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    • 2009
  • The main stream of CD137 studies has been directed to the function of CD137 in $CD8^+$ T-cell immunity, including its anti-tumor activity, and paradoxically the immunosuppressive activity of CD137, which proves to be of a great therapeutic potential for animal models of a variety of autoimmune and inflammatory diseases. Recent studies, however, add complexes to the biology of CD137. Accumulating is evidence supporting that there exists a bidirectional signal transduction pathway for the CD137 receptor and its ligand (CD137L). CD137/CD137L interactions are involved in the network of hematopoietic and nonhematopoietic cells in addition to the well characterized antigen-presenting cell-T cell interactions. Signaling through CD137L plays a critical role in the differentiation of myeloid cells and their cellular activities, suggesting that CD137L signals trigger and sustain inflammation. The overall consequence might be that the amplified inflammation by CD137L enhances the T-cell activity together with CD137 signals by upregulating costimulatory molecules, MHC molecules, cell adhesion molecules, cytokines, and chemokines. Solving this outstanding issue is urgent and will have an important clinical implication.

Effects of Chitosanoligosaccharide on the Hepatotoxicity in Cadmium-treated Mice (키토산올리고당이 카드뮴을 투여한 생쥐의 간독성에 미치는 효과)

  • Yoon, Jung-Sik;Roh, Young-Bok
    • Applied Microscopy
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    • v.33 no.1
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    • pp.59-78
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    • 2003
  • This research was conducted to determine the effects of chitosanoligosaccharide on liver poisoning induced by cadmium (Cd). Three groups of mice were used in this research. The first group was only injected with cadmium (5.0 mg/kg; i.p.) (group Cd) and the second one with cadmium and chitosanoligosaccharide (0.5% solution) at the same time (group Cd+Chi). The third one which had already been injeted with chitosanoligosaccharide (0.5% Solution) aweek before (group Ch7+Cd) was used. In order to investigate the inhibitory action of chitosanoligosaccharide on liver damage, enzyme activity in serum, glutathione peroxidase (GSHPx) activity and glutathione reductase (GR) activity were relatively measured. In addition, histological observations were made to determine the morphologic injury of liver tissues. As the result of enzyme activity in serum, the activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) in chitosanoligosaccharide-injected groups Cd+Chi and Chi7+Cd was lower than in group Cd. GSH-Px activity was sharply increased in groups Cd+Chi and Chi7+Cd compared to group Cd. GR activity was conspicuously decreased in groups Cd+Chi and Chi7+Cd compared to group Cd. As the result of light microscopic observation, liver cell necrosis caused by cadmium poisoning was obseved in liver cells. The finding of group Cd+Chi and Chi7+Cd was similar total on of normal groups. As the result of electron microscopic observation, mitochondria in group Cd showed a severe swelling phenomenon, RER fragment and ribosome dropout. However, in groups Cd+Chi and Chi7+Cd, mitochondria wiht high electron density were distributed and RER forming a typical lamellae with ribosome was observed. From these results, cadmium toxicity on rat liver tissues could be lessened by chitosanoligosaccharide.

Expression Pattern of T Lymphocyte Regulatory Factors in Unstimulated Whole Saliva of Erosive Oral Lichen Planus and Recurrent Aphthous Stomatitis Patients (미란형 구강편평태선과 재발성 아프타성 구내염 환자들의 비자극성 전타액내 T림프구 조절인자들의 발현 양상)

  • Yoon, Seon-Hack;Ko, Hyun-Mi;Park, Ji-Il;Kim, Jae-Hyung
    • Journal of Oral Medicine and Pain
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    • v.34 no.4
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    • pp.363-369
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    • 2009
  • Erosive oral lichen planus (EOLP) and recurrent aphthous stomatitis (RAS) are T-cell mediated inflammatory immune disorders. It was investigated mRNA expression pattern of several regulatory factors, such as, CD28, CD45, CD152, CD154, CD279, which influence T lymphocyte in unstimulated whole saliva (UWS) of EOLP and RAS patients. It was collected unstimulated whole saliva during 10 minute in EOLP 18 people, RAS patients 12 people, healthy control 8 people. We investigated mRNA expression of T lymphocyte regulatory factors, such as, CD28, CD45, CD152, CD154, CD279, with real time reverse transcription polymerase chain reaction. In EOLP group, CD45, CD279 expressed higher and CD154 expressed lower than control. In RAS, CD45, CD270 expressed higher and CD28, CD154 expressed lower than control. In addition CD152 salivary mRNA expression of EOLP is higher than that of RAS. The above results were suggested that the mRNA expression of T lymphocyte regulatory factors in unstimulated whole saliva of EOLP and RAS contributes to diagnosis of diseases.