• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2701-2706
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• 2009

The polymer blends containing polypyrrole (PPy) and the sulphonic acids such as β-naphthalene sulfonic acid (NSA), camphor sulfonic acid (CSA), and dodecylbenzenesulfonic acid (DBSA) were synthesized by in situ deposition technique in an aqueous media using ammonium per sulfate (APS) as an initiator. The obtained films were characterized by scanning electron microscopy (SEM), and the thermal behavior of these polymer blends was analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The temperature-dependent (DC) conductivity of the obtained films shows a semiconducting behavior with a negative temperature coefficient of resistivity (TCR). The conductivity data were also analyzed through Mott’s equation, which provides the variable range hopping model in three dimensions. The parameters such as density of states at the Fermi energy, hopping energy, and hopping distance were calculated for PPy, PPy-NSA, PPy-CSA, and PPy-DBSA films, and the data were compared.

• Asian-Australasian Journal of Animal Sciences
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• 제25권3호
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• pp.382-392
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• 2012

This study evaluated the effects of dietary anticoccidial drugs plus antibiotic growth promoters (AGPs) on parameters of immunity in commercial broiler chickens. Day-old chicks were raised on used litter from a farm with endemic gangrenous dermatitis to simulate natural pathogen exposure and provided with diets containing decoquinate (DECX) or monensin (COBN) as anticoccidials plus bacitracin methylene disalicylate and roxarsone as AGPs. As a negative control, the chickens were fed with a non-supplemented diet. Immune parameters examined were concanavalin A (ConA)-stimulated spleen cell proliferation, intestine intraepithelial lymphocyte (IEL) and spleen cell subpopulations, and cytokine/chemokine mRNA levels in IELs and spleen cells. ConA-induced proliferation was decreased at 14 d post-hatch in DECX-treated chickens, and increased at 25 and 43 d in COBN-treated animals, compared with untreated controls. In DECX-treated birds, increased percentages of $MHC2^+$ and $CD4^+$ IELS were detected at 14 d, but decreased percentages of these cells were seen at 43 d, compared with untreated controls, while increased $TCR2^+$ IELs were evident at the latter time. Dietary COBN was associated with decreased fractions of $MHC2^+$ and $CD4^+$ IELs and reduced percentages of $MHC2^+$, $BU1^+$, and $TCR1^+$ spleen cells compared with controls. The levels of transcripts for interleukin-4 (IL-4), IL-6, IL-17F, IL-13, CXCLi2, interferon-${\gamma}$ (IFN-${\gamma}$), and transforming growth factor${\beta}$4 were elevated in IELs, and those for IL-13, IL-17D, CXCLi2, and IFN-${\gamma}$ were increased in spleen cells, of DECX- and/or COBN-treated chickens compared with untreated controls. By contrast, IL-2 and IL-12 mRNAs in IELs, and IL-4, IL-12, and IL-17F transcripts in spleen cells, were decreased in DECX- and/or COBN-treated chickens compared with controls. These results suggest that DECX or COBN, in combination with bacitracin and roxarsone, modulate the development of the chicken post-hatch immune system.

• 한국전기전자재료학회논문지
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• 제36권3호
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• pp.249-254
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• 2023

La_0.7-xCe_xSr_0.3MnO₃ specimens were fabricated by a solid state reaction method and structural and electrical properties with variation of Ce⁴⁺ contents were measured. All specimens exhibited a polycrystalline rhombohedral crystal structure, and the (110) peaks were shifted to low angle side with increasing the amount of Ce⁴⁺ contents. As Ce⁴⁺ ions with different ion radii and charges are substituted with La³⁺ ions, electrical properties are thought to be affected by changes in the double exchange interaction between Mn³⁺-Mn⁴⁺ ions due to distortion of the unit lattice, a decrease in oxygen vacancy concentration, and an increase in lattice defects. Resistivity gradually decrease as the amount of Ce⁴⁺ added increased, and negative temperature coefficient of resistance (NTCR) properties were shown in all specimens. In the La_0.5Ce_0.2Sr_0.3MnO₃ specimens, electrical resistivity, TCR and B-value were 31.8 Ω-cm, 0.55%/℃ and 605 K, respectively.

• 대한세포병리학회지
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• 제18권2호
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• pp.126-132
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• 2007

The aim of this study was to evaluate the diagnostic value of fine needle aspiration cytology (FNAC) for the assessment of palpable enlarged lymph nodes. The authors reviewed the results of 1,346 FNACs of palpable enlarged lymph nodes performed at Pusan National University Hospital from 1998 to 2004. Of the 1,346 cases, 1,265 (94.0%) were satisfactory and 81 (6.0%) unsatisfactory. Cytologic diagnoses were judged in 488 cases, based on subsequent histologic diagnoses, clinical follow up, or both. Global results for all malignancies (lymphoid and non-lymphoid neoplasms) based on cases with final diagnoses, showed a sensitivity of 87.4% and a specificity of 98.7%. The overall diagnostic accuracy was 93,2%, and the false negative rate reduced from 12,6% to 7,3% when lymphomatous cases were excluded. The annual data for this period showed that the number of diagnostic lymph node biopsies and the rate of inadequately sampled material markedly decreased. Gene rearrangement studies for IgH and TCR ${\gamma}$ were helful in 30 cases. FNAC is a useful initial diagnostic procedure for the evaluation of palpable enlarged lymph nodes. However, the technique should be assisted by the appropriate ancillary studies and by proper interpretation by a cytopathologist.

• 한국전기전자재료학회논문지
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• 제35권3호
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• pp.292-296
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• 2022

(La_0.5Nd_0.2Sr_0.3)MnO₃ specimens were prepared by a solid-state reaction. In all specimens, X-ray diffraction patterns of an orthorhombic structure were shown. The fracture surfaces of (La_0.5Nd_0.2Sr_0.3)MnO₃ specimens showed a transgranular fracture pattern be possibly due to La ions (0.122 nm) as a perovskite A-site dopant substituting for Nd ions (0.115 nm) having a small ionic radius. The full-width at half maximum (FWHM) of the Mn 2p XPS spectra showed a value greater than that [8] of the single valence state, which is believed to be due to the overlapping of Mn²⁺, Mn³⁺, and Mn⁴⁺ ions. The dependence of Mn 2p spectra on the Mn³⁺/Mn⁴⁺ ratio according to sintering time was not observed. Electrical resistivity resulted in the minimum value of 100.7 Ω-cm for the specimen sintered for 9 hours. All specimens show a typical negative temperature coefficient of resistance (NTCR) characteristics. In the 9-hour sintered specimen, TCR, activation energy, and B25/65-value were -1.24%/℃, 0.19 eV, and 2,445 K, respectively.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.4031-4036
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• 2012

Background: The negative signaling provided by interactions of the co-inhibitory molecule, programmed death-1 (PD-1), and its ligands, B7-H1 (PD-L1) and B7-DC (PD-L2), is a critical mechanism contributing to tumor evasion; blockade of this pathway has been proven to enhance cytotoxic activity and mediate antitumor therapy. Here we evaluated the anti-tumor efficacy of AAV-mediated delivery of the extracellular domain of murine PD-1 (sPD-1) to a tumor site. Material and Methods: An rAAV vector was constructed in which the expression of sPD-1, a known negative regulator of TCR signals, is driven by human cytomegalovirus immediate early promoter (CMV-P), using a triple plasmid transfection system. Tumor-bearing mice were then treated with the AAV/sPD1 construct and expression of sPD-1 in tumor tissues was determined by semi quantitative RT-PCR, and tumor weights and cytotoxic activity of splenocytes were measured. Results: Analysis of tumor homogenates revealed sPD-1 mRNA to be significantly overexpressed in rAAV/sPD-1 treated mice as compared with control levels. Its use for local gene therapy at the inoculation site of H22 hepatoma cells could inhibit tumor growth, also enhancing lysis of tumor cells by lymphocytes stimulated specifically with an antigen. In addition, PD-1 was also found expressed on the surfaces of activated CD8+ T cells. Conclusion: This study confirmed that expression of the soluble extracellular domain of PD-1 molecule could reduce tumor microenvironment inhibitory effects on T cells and enhance cytotoxicity. This suggests that it might be a potential target for development of therapies to augment T-cell responses in patients with malignancies.

• Clinical and Experimental Pediatrics
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• 제49권4호
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• pp.439-445
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• 2006

목 적 : ${\alpha}$-Galactosylceramide (GalCer)로 자극한 자연살상 T 세포(NKT)는 CD1d 및 T 세포 수용체(T cell receptor) 의존적으로 일부 백혈병에서 항암효과를 발현하나, CD1d음성인 신경모세포종에서는 세포독성을 유도할 수 없다. 이들 NKT세포의 활성화 시 분비되는 많은 양의 사이토카인의 직접적인 항암효과에 대해서는 소수의 보고가 있다. 본 연구에서는 hCD1d/${\alpha}$-GalCer tetramer로 NKT세포를 자극하여 얻은 상청액(supernatant)을 이용하여 NKT세포에 의한 신경모세포종의 치료적 접근의 가능성을 알아보았다. 방 법 : 신경모세포종 세포 주를 IMDM 배지에 배양하였고, NKT세포에서 분비되는 사이토카인 양은 cytometric bead array (CBA)분석으로 측정하였다. 세포 생존율은 calcein-AM 형광물질을 이용하여 digital image microscopy scanning (DIMSCAN)으로 측정하였고 특이 세포고사(specific apoptosis)는 annexin V and 7-AAD 염색 후 유식세포분석기를 통하여 산출하였다. 결 과 : 활성화된 NKT세포는 많은 양의 IL-2, IL-4, INF-${\gamma}$와 TNF-${\alpha}$을 분비하였다. NKT 자극 후 얻어진 상청액은 8개의 신경모세포종 세포 주 중 4개에서 의미있는 세포독성을 나타냈으며, 그 기전은 annexin-V 염색이나 pancaspase 억제제의 전 처치 실험으로 세포고사을 통하여 유도됨을 알 수 있었다. 그리고 이들 세포고사 유도는 anti-TNF-${\alpha}$, anti-IFN-${\gamma}$ 중화항체의 단독투여 시 현저히 감소하였고 동시투여 시에는 완전하게 억제되었다. 결 론 : NKT 세포의 활성화에 의해 분비된 IFN-${\gamma}$와 TNF${\alpha}$가 일부 신경모세포종 세포 주에서 협동적 세포 독성을 유도하였다.