• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.9
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• pp.696-700
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• 2010

We fabricated red and blue organic light emitting display (OLEDs) which had the two kinds of multi-structure of ITO/HIL/HTL/EML/ETL/LiF/Al and ITO/HIL/HTL/EML/ETL/LiF/Al/LiF. In the case of red OLED that had LiF/Al/LiF structure compared to LiF/Al structure, the current density increased from 4.3 mA/$cm^2$ to 7.3 mA/$cm^2$, and the brightness increased from 488 cd/$m^2$ to 1,023 cd/$m^2$ at 7.0 V, and as a result the current efficiency was improved from 11.28 cd/A to 13.95 cd/A. Also in the case of blue OLED that had LiF on Al cathode layer, the current density increased from 1.2 mA/$cm^2$ to 1.8 mA/$cm^2$, and the brightness increased from 45 cd/$m^2$ to 85 cd/$m^2$ at 7.0 V, and as a result the current efficiency was improved from 3.69 cd/A to 4.82 cd/A. Through these experimental results it could be suggested that the LiF layer formed on Al prevents the oxidation of Al surface, and the electrode resistance become low with increase of supplied electrons, therefore the brightness and the efficiency are improved from the influence to the well-balanced bonding of electron and hole at emitting layer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.221-227
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• 2014

Background: Aberrant phenotypes in acute leukemia have variable frequency and their prognostic and predictive relevance is controversial, despite several reports of clinical significance. Aims: To determine the prevalence of aberrant antigen expression in acute leukemia, assess clinical relevance and demonstrate immunophenotype-karyotype correlations. Materials and Methods: A total of 73 (40 AML and 33 ALL) newly diagnosed acute leukemia cases presenting to KAMC, Kingdom of Saudi Arabia, were included. Diagnosis was based on WHO criteria and FAB classification. Immunophenotyping by flow cytometry, conventional karyotyping and fluorescence in situ hybridization for gene rearrangements were performed. Results: Aberrant antigens were detected in 27/40 (67.5%) of AML and in 14/33 (42.4%) in ALL cases. There were statistically significant higher TLC in Ly+ AML than in Ly-AML (p=0.05) and significant higher blast count in ALL with aberrant antigens at presentation and day 14 (p=0.005, 0.046). There was no significant relation to clinical response, relapse free survival (RFS) or overall survival (p>0.05), but AML cases expressing ${\geq}2$ Ly antigens showed a lower median RFS than those expressing a single Ly antigen. In AML, CD 56 was expressed in 11/40. CD7 was expressed in 7/40, having a significant relation with an unfavorable cytogenetic pattern (p=0.046). CD4 was expressed in 5/40. CD19 was detected in 4/40 AML associated with M2 and t (8; 21). In ALL cases, CD33 was expressed in 7/33 and CD13 in 5/33. Regarding T Ag in B-ALL CD2 was expressed in 2 cases and CD56 in 3 cases. Conclusions: Aberrant antigen expression may be associated with adverse clinical data at presentation. AML cases expressing ${\geq}2$ Ly antigens may have shorter median RFS. No specific cytogenetic pattern is associated with aberrant antigen expression but individual antigens may be related to particular cytogenetic patterns. Immunophenotype-karyotype correlations need larger studies for confirmation.

• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.21-27
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• 2003

The purpose of this study was to investigate the distribution and characteristics of heavy metals in the fallout dust deposits at the middle and high schools. We collected the samples at 60 schools in Kongju, Incheon and Daejeon on from September to November, 2001, and analyzed Cadmium(Cd), Copper(Cu), Lead(Pb) and Zinc(Zn) from them. Zn was the highest level as 551 $\pm$ 79.9 ppm, and the next order were Pb, Cu, and Cd as 146.0 $\pm$ 15.2 ppm, 98.7 $\pm$ 14.4 ppm and 5.21 $\pm$ 0.76 ppm, respectively. The rates of schools exceeding the soil environmental standards were 56.3% in Cd, 53.3% in Zn, 51.5% in Pb, and 31.7% in Cu, respectively. Cd and Pb were the highest levels at schools in Daejeon as 6.30 $\pm$ 0.87 ppm and 171 $\pm$ 26.1 ppm, respectively. Cu and Zn were the highest levels at schools in Incheon as 176.2 $\pm$ 55.8 ppm and 919.8 $\pm$ 185.7 ppm, respectively. At Incheon, Cu and Zn levels were significantly higher than Kongju(p=0.04l), and Daejeon(p=0.016), respectively. Total pollution index(PI) of heavy metals was 1.51 $\pm$ 0.16. PI was 2.00 $\pm$ 0.51 on Incheon, 1.50 $\pm$ 0.13 on Daejeon, and 0.92 $\pm$ 0.24 on Kongju. Correlations were 0.675 (p<0.05) between Cu and Cd, 0.663(p<0.05) between Cu and Zn, and 0.477 between Cd and Pb. In conclusion, Among heavy metals in the fallout dust deposits at schools, Cu and Zn were the highest levels at Incheon, Cd and Pb were the highest levels at Daejeon.

• Korean Journal of Crystallography
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• v.9 no.1
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• pp.53-63
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• 1998

The Cd1-xZnxS thin films were grown on the Si(100) wafers by a hot wall epitaxy method (HWE). the source and substrate temperature are 600℃ and 440℃, respectively. The crystalline structure of epilayers was investigated by double crystal X-ray diffraction (DCXD). Hall effect on the sample was measured by the van der Pauw method and the carrier density and mobility dependence of Hall characteristics on temperature was also studied. In order to explore the applicability as a photoconductive cell, we measured the sensitivity (γ), the ratio of photocurrent to darkcurrent (pc/dc), maximum allowable power dissipation (MAPD), spectral response and response time. The results indicated that the best photoconductive characteristic were observed in the Cd0.53Zn0.47S samples annealed in Cu vapor comparing with in Cd, Se, air and vacuum vapour. Then we obtained the sensitivity of 0.99, the value of pc/dc of 1.65 × 107, the MAPD of 338mW, and the rise and decay time of 9.7 ms and 9.3 ms, respectively.

• IMMUNE NETWORK
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• v.7 no.2
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• pp.80-86
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• 2007

Background: CD40-activated B (CD40-B) cells might be an attractive source of autologous antigen-presenting cells (APCs) for immunotherapy due to the convenience to obtain from peripheral blood and expand in vitro. Moreover, CD40-B cells were found to be comparable with DCs in their capacity to raise antigen-specific CD8+ T cells. Here, we have established K562 cells expressing CD40L to expand CD40-activated B cells used for APCs. Methods: After activation of B cell by K562/CD40L, CD40-B cells were examined by counting B cell numbers. Surface expression of CD54, CD80, CD86 and HLA class II was measured by flow cytometry. The CD40-B cells were tested for its function as APC by mixed lymphocyte reactions (MLR) and by induction of T cell responses specific for pp65 peptide in vitro. Results: The expansion of B cells by K562/CD40L increased about 6-folds compared with anti-CD40 or K562. Furthermore, the expression of CD54, CD80, CD86 and HLA class II was up-regulated by K562/CD40L. B cells by K562/CD40L showed comparable antigen presentation activity with mature DCs as shown in MLR, INF-${\gamma}$ ELISPOT assay. Conclusion: These results suggest that K562/CD40L could be used to generate activated B cells as potent APCs which could be useful for cellular vaccination and adoptive immunotherapy.

• Biomedical Science Letters
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• v.1 no.1
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• pp.19-25
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• 1995

Characterization of immune cell subpopulations in the bovine was performed using a direct immunofluorescence technique adaptable for routine and repeated monitoring. This whole blood procedure is faster and requires less volume than conventional density gradient isolation methods. Low inter-and intra-animal variations were seen in hematology parameters and in CD4, CD8 and CD2 lymphocyte subtypes. CD4 values were 30% of lymphocytes in male and 32% in females. Thriteen percent were CD8 in males and 13% in females. CD4: CD8 ratios were approximately two in both sexes. Fiffty three percent were CD2 in males and 54% in females. The mean RBC counts of peripheral blood were 7.20$\times10^6/{mm}^3$ for male cattle and 6.36$\times10^6/{mm}^3$ for females. The mean WBC counts were 8.09$\times10^3/{mm}^3$ for males and 7.09$\times10^3/{mm}^3$ for females. The percent of lymphocytes(63-65%) was higher than the percent of neutrophils(17-18%), the percent of eosinophils(11-15%), te percent of monocytes(4-5%), and percent of basophiles(1%).

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.318.2-318.2
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• 2014

The high contact resistance is still one of the major issues to be resolved in CdS/CdTe thin film solar cells. CdTe/Metal Schottky contact induced a high contact resistance in CdS/CdTe solar cells. It has been reported that the work function of CdTe thin film is more than 5.7 eV. There has not been a suitable back contact metal, because CdTe thin film has a high work function. In a few decades, some buffer layer was reported to improve a back contact problem. Buffer layers which are Te, $Sb_2Te_3$, $Cu_2Te$, ZnTe:Cu and so on was inserted between CdTe and metal electrode. A formed buffer layers made a tunnel junction. Hole carriers which was excited in CdTe film by light absorption was transported from CdTe to back metal electrode. In this report, we reported the variation of solar cell performance with different buffer layer at the back contact of CdTe thin film solar cell.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.5
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• pp.255-259
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• 2003

Dendritic cells (DCs) play a critical role in various immune responses involving $CD4^+$ T cells and have been used to generate anti-tumor immunity. Chemotherapy induces severe side effects including immunosuppression in patients with cancer. Although immunosuppression has been studied, the effects of anticancer drugs on DCs are not fully determined. In this study, we demonstrated that CD40 activation strongly protected DCs from 5-fluorouracil (5-FU) or mitomycin C-induced apoptosis. DCspecific surface markers, including CD11c and major histocompatibility complex (MHC) class II, were used for identifying DCs. CD 40 activation with anti-CD40 mAb significantly enhanced the viability of DCs treated with 5-FU or mitomycin C, assayed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). Fluorescence staining and analysis clearly confirmed the enhancing effect of anti-CD40 mAb on the viability of DCs, suggesting that CD40 activation may transduce critical signals for the viability of DCs. Annexin V staining assay showed that CD40 significantly protected DCs from 5-FU or mitomycin C-induced apoptosis. Taken together, this study shows that CD40 activation with anti-CD40 mAb has strong anti-apoptosis effect on DCs, suggesting that CD40 activation may overcome the immunosuppression, especially downregulation of number and function of DCs in chemotherapy-treated cancer patients.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6433-6438
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• 2013

In hepatocellular cancer (HCC), lack of response to chemotherapy and radiation treatment can be caused by a loss of epigenetic modifications of cancer cells. Methionine adenosyltransferase 1A is inactivated in HCC and may be stimulated by an epigenetic change involving promoter hypermethylation. Therefore, drugs releasing epigenetic repression have been proposed to reverse this process. We studied the effect of the demethylating reagent 5-aza-2'-deoxycitidine (5-Aza-CdR) on MAT1A gene expression, DNA methylation and S-adenosylmethionine (SAMe) production in the HCC cell line Huh7. We found that MAT1A mRNA and protein expression were activated in Huh7 cells with the treatment of 5-Aza-CdR; the status of promoter hypermethylation was reversed. At the same time, MAT2A mRNA and protein expression was significantly reduced in Huh7 cells treated with 5-Aza-CdR, while SAMe production was significantly induced. However, 5-Aza-CdR showed no effects on MAT2A methylation. Furthermore, 5-Aza-CdR inhibited the growth of Huh7 cells and induced apoptosis and through down-regulation of Bcl-2, up-regulation of Bax and caspase-3. Our observations suggest that 5-Aza-CdR exerts its anti-tumor effects in Huh7 cells through an epigenetic change involving increased expression of the methionine adenosyltransferase 1A gene and induction of S-adenosylmethionine production.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.27 no.6
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• pp.345-354
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• 2024

Purpose: The study aimed to investigate the recruiting of T lymphocytes including IL-7Rα^low CX3CR1⁺ effector memory (EM) CD8⁺ T cells and α4β7 integrin tagged T cells to inflamed intestinal mucosa. Methods: Whole blood and mucosal tissues of intestine were collected from 40 children with or without inflammatory bowel disease (IBD). T cell surface staining and immunohistochemistry were done with several antibodies in peripheral blood mononuclear cells (PBMCs) and intestinal mucosa, respectively. Serum levels of cytokines were measured by ELISA. Results: The frequency of IL-7Rα^lowCX3CR1⁺ EM CD8⁺ T cells in the PBMC was significantly higher in the ulcerative colitis group than in the control group (57.9±17.80% vs. 33.9±15.70%, p=0.021). The frequency of integrin α4β7⁺ CD4⁺ T cells in the PBMC was significantly lower in the ulcerative colitis group than in the control group (53.2±27.6% vs. 63.9±13.2%, p=0.022). Serum concentration of TNF-α was higher in the Crohn's disease group than in the control group (26.13±5.01 pg/mL vs. 19.65±6.07 pg/mL, p=0.008). Of the three groups, the ulcerative colitis group had the highest frequency of integrin α4β7⁺ T cells based on immunohistochemistry analyses for intestinal tissues, followed by the Crohn's disease group and the control group (4.63±1.29 cells vs. 2.0±0.57 cells vs. 0.84±0.52 cells, p<0.001). Conclusion: Trafficking immune cells with effector memory CD8⁺ T cells clarified by IL-7Rα^lowCX3CR1⁺ and integrin α4β7⁺ CD4⁺ T cells might be highly associated with the pathogenesis of ulcerative colitis.