• 천문학회보
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• 제43권1호
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• pp.37.1-37.1
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• 2018

A Korean VLBI Network key science program, the Interferometric Monitoring of Gamma-ray Bright AGNs (iMOGABA) program continues to reveal the nature of the gamma-ray flares in active galactic nuclei (AGNs). Here in this presentation, we would like to introduce an interesting story about four gamma-ray bright AGNs - BL Lac, 1633+382, 3C 84, and M87 - based on the recent results of the iMGOABA. The results will include a) a sad story of an 'orphan' gamma-ray flare from BL Lac, b) a position offset of 40 pc for a gamma-ray flaring site from the radio regions in 1633+382, c) a position alignment of a gamma-ray flaring site with a central engine region in 3C 84, and d) a flat millimeter spectrum of a core in M87 revealed by the iMOGABA.

• Biomolecules & Therapeutics
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• 제12권3호
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• pp.145-150
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• 2004

Inflammation is a frequent radiation-induced reaction following therapeutic irradiation. Treatment of human umbilical endothelial cells (HUVEC) with ${\gamma}$-irradiation (${\gamma}$IR) induces the expression of adhesion proteins such as intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Since the upregulation of these proteins on endothelial cell Surface has been known to be associated with inflammation, interfering with the expression of adhesion molecules is an important therapeutic target. In the present study, we demonstrate that vitamin C inhibits ${\gamma}$IR induced expression of ICAM-1, VCAM-1, and E-selectin on HUVEC in a dose- and time dependent manner. Vitamin C a1so inhibited the production of Nitric oxide (NO) induced by ${\gamma}$IR. These data suggest that vitamin C has therapeutic potential for the treatment of various inflammatory disorder associated with an increase of endothelial leukocyte adhesion molecules.

• 한국재료학회지
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• 제12권5호
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• pp.414-422
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• 2002

Three different multi-component white cast irons alloyed with Cr, V, Mo and W were prepared in order to study their as-cast and solidification structures. Three combinations of the alloying elements were selected so as to obtain the different types of carbides and matrix structures : 3%C-10%Cr-5%Mo-5%W(alloy No.1), 3%C-10%V-5% Mo-5%W(alloy No. 2) and 3%C-17%Cr-3% V(alloy No.3). The as-cast microstructures were investigated with optical and scanning electron microscopes. There existed two different types of carbides, $M_7C_3$ carbide with rod-like morphology and $M_6C$ carbide with fishbone-like one, and matrix in the alloy No. 1. The alloy No. 2 consisted of MC carbide with chunky and flaky type and needle-like $M_2C$ carbide, and matrix. The chunky type referred to primary MC carbide and the flaky one to eutectic MC carbide. The morphology of the alloy No. 3 represented a typical hypo-eutectic high chromium white cast iron composed of rod-like $M_7C_3$ carbide which is very sensitive to heat flow direction and matrix. To clarify the solidification sequence, each iron(50g) was remelted at 1723K in an alumina crucible using a silicon carbide resistance furnace under argon atmosphere. The molten iron was cooled at the rate of 10K/min and quenched into water at several temperatures during thermal analysis. The solidification structures of the specimen were found to consist of austenite dendrite(${\gamma}$), $ ({\gamma}+ M_7C_3)$ eutectic and $({\gamma}+ M_6C)$ eutectic in the alloy No. 1, proeutectic MC, austenite dendrite(${\gamma}$), (${\gamma}$+MC) eutectic and $({\gamma}+ M_2C)$ eutectic in the alloy No. 2, and proeutectic $M_7C_3$ and $ ({\gamma}+ M_7C_3)$ eutectic in the alloy No 3. respectively.

• 대한수학회지
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• 제49권4호
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• pp.733-743
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• 2012

For the "Hopf bundle" $S^1{\rightarrow}S^{2n,1}{\rightarrow}\mathbb{C}H^n$, horizontal lifts of simple closed curves are studied. Let ${\gamma}$ be a piecewise smooth, simple closed curve on a complete totally geodesic surface $S$ in the base space. Then the holonomy displacement along ${\gamma}$ is given by $$V({\gamma})=e^{{\lambda}A({\gamma})i}$$ where $A({\gamma})$ is the area of the region on the surface $S$ surrounded by ${\gamma}$; ${\lambda}=1/2$ or 0 depending on whether $S$ is a complex submanifold or not. We also carry out a similar investigation for the complex Heisenberg group $\mathbb{R}{\rightarrow}\mathcal{H}^{2n+1}{\rightarrow}\mathbb{C}^n$.

• 대한수학회지
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• 제46권3호
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• pp.657-673
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• 2009

The fixed point algebra $C^*(E)^{\gamma}$ of a gauge action $\gamma$ on a graph $C^*$-algebra $C^*(E)$ and its AF subalgebras $C^*(E)^{\gamma}_{\upsilon}$ associated to each vertex v do play an important role for the study of dynamical properties of $C^*(E)$. In this paper, we consider the stability of $C^*(E)^{\gamma}$ (an AF algebra is either stable or equipped with a (nonzero bounded) trace). It is known that $C^*(E)^{\gamma}$ is stably isomorphic to a graph $C^*$-algebra $C^*(E_{\mathbb{Z}}\;{\times}\;E)$ which we observe being stable. We first give an explicit isomorphism from $C^*(E)^{\gamma}$ to a full hereditary $C^*$-subalgebra of $C^*(E_{\mathbb{N}}\;{\times}\;E)({\subset}\;C^*(E_{\mathbb{Z}}\;{\times}\;E))$ and then show that $C^*(E_{\mathbb{N}}\;{\times}\;E)$ is stable whenever $C^*(E)^{\gamma}$ is so. Thus $C^*(E)^{\gamma}$ cannot be stable if $C^*(E_{\mathbb{N}}\;{\times}\;E)$ admits a trace. It is shown that this is the case if the vertex matrix of E has an eigenvector with an eigenvalue $\lambda$ > 1. The AF algebras $C^*(E)^{\gamma}_{\upsilon}$ are shown to be nonstable whenever E is irreducible. Several examples are discussed.

• 대한화학회지
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• 제32권6호
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• pp.543-548
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• 1988

1∼5wt%의 구리가 얹혀진 ${\gamma}$-알루미나 또는 티타니아에서 금속-지지체 상호작용을 승온환원과 상자성 공명으로 연구하였다. $500^{\circ}C에서 시료를 산소로 처리했을 때 티타니아계에서는 구리 함량이 증가함에 따라 고온쪽으로 승온환원 피이크가 증가했으나 알루미나 계에서는 저온쪽의 승온 환원 피이크가 커졌다. $300^{\circ}C 처리 경우에는 알루미나계에서는 $300^{\circ}C에서 티타니아계는 120 과 $300^{\circ}C에서 각각 환원피이크를 보여주었다. ${\gamma}$-알루미나에서는 $Cu^{2+}$의 전형적인 상자성 신호가 나타났으나 티타니아에서는 넓고 작은 신호만 관찰되었다. 이들 결과들로부터 금속-지지체 상호작용은 실리카 < 티타니아 < ${\gamma}$-알루미나의 순으로 커지며 산화구리는 지지체에 따라 서로 다른 담지특성을 가짐을 알 수 있었다.

• 한국가금학회:학술대회논문집
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• 한국가금학회 1999년도 제16차 정기총회및학술발표회
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• pp.34-50
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• 1999

A cDNA encoding chicken interferon-gamma (chIFN-${\gamma}$) was amplified from P34, a CD4$^{+}$ T-cell hybridoma by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into pUC18. THe sequences of cloned PCR products were determined to confirm the correct cloning. Using this cDNA as probe, chicken genomic library from White Leghorn spleen was screened. Phage clones harboring chicken interferon-gamma (chIFN-${\gamma}$) were isolated and their genomic structure elucidated. The chIFN-${\gamma}$ contains 4 exons and 3 introns spanning over 14 kb, and follows the GT/AG rule for correct splicing at the exon/intron boundaries. The four exons encode 41, 26, 57 and 40 amino acids, respectively, suggesting that the overall structure of IFN-${\gamma}$ is evolutionairly conserved in mammalian and avian species. The 5’-untranslated region and signal sequences are located in exon 1. Several AT-rich sequences located in the fourth exon may indicate a role in mRNA turnover. The 5’-flanking region contains sequences homologous to the potential binding sites for the mammalian transcription factors, activator protein-1(AP-1) activator protein-2(AP-2) cAMP-response element binding protein(CREB), activating transcription factor(ATF), GATA-binding fator(GATA), upstream stimulating factor(USF), This suggests that the mechanisms underlying transcriptional regulation of chicken and mammalian IFN-${\gamma}$ genes may be similar.r.

• 대한후두음성언어의학회지
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• 제12권2호
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• pp.126-132
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• 2001

Background and Objectives : Signal traduction through phospholipase C(PLC) participate in the regulation of cell growth and differentiation. Growth factors bind to their receptors and thereby induce tyrosine phophorylation of the phospholipase C-${\gamma}$1(PLC-${\gamma}$1). PLC-${\gamma}$1 is a substrate for several receptor tyrosine kinases and its catalytic activity is increased by tyrosine phosphorylation. Tyrosine kinase phosphorylation of PLC-${\gamma}$1 stimulates PLC activation and cell proliferation. However the signal transduction pathway and the significance of PLC in injured recurrent laryngeal nerve regeneration is unknown. Therefore after we obtained fuctionally recovered rats using PEMF in this study, we attempt to provide some evidence that PLC plays a role in nerve regeneration itself and regeneration related to PEMF through the analysis of the difference between fucntional recovery group and non-recovery group in the recurrent laryngeal nerve. Materials and Method : Using 32 healthy male Sprague-Dawley rats, transections and primary anastomosis were performed on their left recurrent laryngeal nerves. Rats were then randomly assigned to 2 groups. The experimental group(n=16) received PEMS by placing them in custom cages equipped with Helm-holz coils(3hr/day, 5days/wk, for 12wk). The control group(n=16) were handled the same way as the experimental group, except that they did not receive PEMS. Laryngo-videoendoscopy was performed before and after surgery and followed up weekly. Laryngeal EMG was obtained in both PCA and TA muscles. Immunohistochemisty staining and Western blotting analysis using monoclonal antibody was performed to detect PLC-${\gamma}$1 in recurrent laryngeal nerve and nodose ganglion. Results : 10 rats(71%) in experimental group and 4 rats(38%) in the control group showed recovery of vocal fold motion. Functionally-recoverd rats show PLC-${\gamma}$1 positive cells in neuron and ganglion cells after 12 weeks from nerve injury. Conclusion : This study shows that PLC1-${\gamma}$ involved in singnal trasduction pathway in functinal recovery of injured recurrent laryngeal nerve and PEMF enhance the functional recovery by effect on this molecule.

• 생명과학회지
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• 제22권10호
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• pp.1316-1323
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• 2012

본 연구는 한우유래 myoblast에서 지방세포분화 유도 전사인자들을 과발현시켜 지방세포로의 교차분화를 유도하기 위하여 실시하였다. 한우 유래 satellite cell을 배양한 후 adipogenic transcription factor인 $PPAR{\gamma}$, C/$EBP{\alpha}$, SREBP1c, KLF5등을 단독 또는 co-transfection을 실시하여 세포에 과발현을 유도하였다. 이들 세포들은 adipogenic differentiation medium에서 2일간 배양한 후growth medium에서 8일간 추가로 배양하였다. 지방세포로의 교차분화 유무는 Oil-red O염색과 지방세포 마커 유전자들의 발현으로 확인하였다. $PPAR{\gamma}$과 C/$EBP{\alpha}$를 각각 단독으로 과발현을 유도한 경우myoblast에서 지방세포로의 교차분화를 유도하기에는 충분하지 못하였다. 그러나 $PPAR{\gamma}$와 C/$EBP{\alpha}$을 co-transfection을 실시한 경우 지방세포로의 교차분화가 유도되었고, 세포내지방구형성, 지방세포 마커유전자의 발현, 근세포 마커유전자의 발현 감소 등이 확인되었다. KLF5 와 $PPAR{\gamma}$를 동시에 과발현할 경우 지방세포로의 교차분화를 볼 수 있었지만 KLF단독의 경우는 교차분화를 유도하지 못하였다. 할성형SREBP1c (tSREBP1c)의 경우, 단독으로 myoblast에 과발현을 처리한 경우만으로 지방세포로의 교차분화를 유도할 수 있었다. 이들 결과는 한우유래 satellite cell을 이용하여 지방세포분화 전사인자를 단독 혹은 조합하여 이들 세포에 과발현 시킬 경우 지방세포로의 교차분화를 유도할 수 있음을 보여 주었다.

• 충청수학회지
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• 제13권1호
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• pp.139-144
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• 2000

The generalized noncommutative torus $T_{\rho}^d$ of rank m was defined in [2]. Assume that for the completely irrational noncommutative subtorus $A_{\rho}$ of rank m of $T_{\rho}^d$ there is no integer q > 1 such that $tr(K_0(A_{\rho}))=\frac{1}{q}{\cdot}tr(K_0(A_{\rho^{\prime}}))$ for $A_{\rho^{\prime}}$ a completely irrational noncommutative torus of rank m. All $C^*$-algebras ${\Gamma}({\eta})$ of sections of locally trivial $C^*$-algebra bundles ${\eta}$ over $M=\prod_{i=1}^{e}S^{2k_i}{\times}\prod_{i=1}^{s}S^{2n_i+1}$, $\prod_{i=1}^{s}\mathbb{PR}_{2n_i}$, or $\prod_{i=1}^{s}L_{k_i}(n_i)$ with fibres $T_{\rho}^d{\otimes}M_c(\mathbb{C})$ were constructed in [6, 7, 8]. We prove that ${\Gamma}({\eta}){\otimes}M_{p^{\infty}}$ is isomorphic to $C(M){\otimes}A_{\rho}{\otimes}M_{cd}(\mathbb{C}){\otimes}M_{p^{\infty}}$ if and only if the set of prime factors of cd is a subset of the set of prime factors of p, that $\mathcal{O}_{2u}{\otimes}{\Gamma}({\eta})$ is isomorphic to $\mathcal{O}_{2u}{\otimes}C(M){\otimes}A_{\rho}{\otimes}M_{cd}(\mathbb{C})$ if and only if cd and 2u - 1 are relatively prime, and that $\mathcal{O}_{\infty}{\otimes}{\Gamma}({\eta})$ is not isomorphic to $\mathcal{O}_{\infty}{\otimes}C(M){\otimes}A_{\rho}{\otimes}M_{cd}(\mathbb{C})$ if cd > 1 when no non-trivial matrix algebra can be ${\Gamma}({\eta})$.