• BMB Reports
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• 제54권6호
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• pp.329-334
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• 2021

Collagen type I is the most abundant form of collagen in human tissues, and is composed of two identical α-1 type I chains and an α-2 type I chain organized in a triple helical structure. A previous study has shown that human collagen α-2 type I (hCOL1A2) promotes collagen synthesis, wound healing, and elastin production in normal human dermal fibroblasts (HDFs). However, the biological effects of human collagen α-1 type I (hCOL1A1) on various skin properties have not been investigated. Here, we isolate and identify the hCOL1A1-collagen effective domain (CED) which promotes collagen type I synthesis. Recombinant hCOL1A1-CED effectively induces cell proliferation and collagen biosynthesis in HDFs, as well as increased cell migration and elastin production. Based on these results, hCOL1A1-CED may be explored further for its potential use as a preventative agent against skin aging.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1162-1164
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• 1995

In this paper, $TiO_2$-xmol%$V_2O_5$, x=0.0, 1.0, 2.0, 3.0 specimens are fabricated by Sol-Gel method. For the improvement of humidity sensitive characteristics for specimens, their microstructures are analysed and the optimum processing condition is established. Grain size increases with substitution rate of $V^{5+}$, on $Ti^{4+}$ site. Their humidity sensitive characteristics is good at 1mol% of $V_2O_5$ rate and heat-treated at $700^{\circ}C$. The capacitance of specimens decreases with frequency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.657-659
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• 1993

We have developed a repetitive TEA $CO_2$ laser excited by a magnetic switch pulse source, and have measured the laser output energy for the mixing ratio of the laser gas mixture in single pulse. As a result of experiments, we have obtained the laser output energy of 252 mJ($\eta_{intrinsic}$=7.8%) in $CO_2:N_2$:He=1:1:8(1 atm.). At a repetition-rate frequency of 10 Hz, an average laser power of 1.5 W was obtained.

• Genomics & Informatics
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• 제12권4호
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• pp.247-253
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• 2014

Osteosarcoma is the most common primary bone tumor, generally affecting young people. While the etiology of osteosarcoma has been largely unknown, recent studies have suggested that cyclooxygenase-2 (COX-2) plays a critical role in the proliferation, migration, and invasion of osteosarcoma cells. To understand the mechanism of action of COX-2 in the pathogenesis of osteosarcoma, we compared gene expression patterns between three stable COX-2-overexpressing cell lines and three control cell lines derived from U2OS human osteosarcoma cells. The data showed that 56 genes were upregulated, whereas 20 genes were downregulated, in COX-2-overexpressed cell lines, with an average fold-change > 1.5. Among the upregulated genes, COL1A1, COL5A2, FBN1, HOXD10, RUNX2, and TRAPPC2 are involved in bone and skeletal system development, while DDR2, RAC2, RUNX2, and TSPAN31 are involved in the positive regulation of cell proliferation. Among the downregulated genes, HIST1H1D, HIST1H2AI, HIST1H3H, and HIST1H4C are involved in nucleosome assembly and DNA packaging. These results may provide useful information to elucidate the molecular mechanism of the COX-2-mediated malignant phenotype in osteosarcoma.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1466-1468
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• 1994

In this paper Dielectric and strain properties of (1-x-y)PMN-yPT-xST Ceramics have been investigated as a function of the amount of $SrTiO_3(ST)$. The $SrTiO_3$ content is ranged from 0.01-0.06(wt%). As the amount of ST is increased, dielectric constant has a maximum value at 0.05 mol composition. The Curie temperature is decreased linearly with increasing ST composition and Polarization properties have been investigated. Coercive field and ramnant polarization has a maximum value at 0.01mol composition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1537-1539
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• 1997

In this study, the dielectric properties of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$ Ceramics have been investigated as a addition of the amount of $MnO_2(0{\leq}x{\leq}0.9wt%)$. The Temperature-dependant dielectric characteristics of 0.9PMN-0.1PT relaxor ferroelectric system were improved by enhencing the extent of the diffuse phase transition(DPT). The maximum dielectric permittivity decreased by substitution $MnO_2$ and the dielectric loss decreased with increasing $MnO_2$ substitution amount. It is expected decreasing in inner heat energy for temperature with increasing $MnO_2$ substitution.

• 미생물학회지
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• 제23권1호
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• pp.9-12
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• 1985

증폭된 재조합 trp operon의 발현을 위한 숙주박테리아 개발의 일환으로 숙수 E. coli에 $aroP^{-}$ 변이를 도입하였다. $aroP^{-}$ 변이의 유도에는 trans po son Tn10을 사용하였으며 P1Kc파아지를 이용하여 숙주박테리아에 형질도입하였다. General aromatic amino acid transport system이 결여된 $aroP^{-}$ 변이주는 $\beta$-thienylalanine ($(2{\times}10^{-4}M)$). p-fluor-phenylalanine ($(2{\times}10^{-4}M)$) 그리고 5-methyltryptophan에 저항성을 가졌다. $aroP^{-}$ 변이주는 $aroP^{-}$ 야생주에 비해서 〔$[^3H]$-tryptophan uptake가 상당히 감소하였다. 또한 NaN, ($(2{\times}10^{-4}M)$)를 처리하였을 때의 ($[^3H]$)-tryptophan uptake 비율은 aroP 변이주가 $aroP^{-}$야생주보다 덜 감소하였다. E. coli $trpR^{-ts}/ColE_1 -trp^+$ 균주에 aroP 형질을 도입하였을 때 트립토판 방출이 $aroP^{-}$ 야생주에 비해서 4 배나 증가하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.98-100
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• 1996

In this paper, the Two-Double 1-2phase exciting driver circuit, in order to improving the starting characteristics of Linear Stepping Motor(LSM), is designed. And the static thrust forces of LSM is measured through the chopper constant current method according to the 2 phase, the Double 1-2phase, and the Two-Double 1-2phase exciting method.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.781-791
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• 2018

BACKGROUND: Glucosamine hydrochloride (GlcN HCl) has been shown to inhibit cell growth and matrix synthesis, but not with N-acetyl-glucosamine (GlcNAc) supplementation. This effect might be related to an inhibition of critical growth factors (GF), or to a different metabolization of the two glucosamine derivatives. The aim of the present study was to evaluate the synergy between GlcN HCl, GlcNAc, and GF on proliferation and cartilage matrix synthesis. METHOD: Bovine chondrocytes were cultivated in monolayers for 48 h and in three-dimensional (3D) chitosan scaffolds for 30 days in perfusion bioreactors. Serum-free (SF) medium was supplemented with either growth factors (GF) $TGF-{\beta}$ ($5ng\;mL^{-1}$) and IGF-I ($10ng\;mL^{-1}$), GlcN HCl or GlcNAc at 1mM each or both. Six groups were compared according to medium supplementation: (a) SF control; (b) SF + GlcN HCl; (c) SF + GlcNAc; (d) SF + GF; (e) SF + GF + GlcN HCl; and (f) SF + GF + GlcNAc. Cell proliferation, proteoglycan, collagen I (COL1), and collagen II (COL2) synthesis were evaluated. RESULTS: The two glucosamines showed opposite effects in monolayer culture: GlcN HCl significantly reduced proliferation and GlcNAc significantly augmented cellular metabolism. In the 30 days 3D culture, the GlcN HCl added to GF stimulated cell proliferation more than when compared to GF only, but the proteoglycan synthesis was smaller than GF. However, GlcNAc added to GF improved the cell proliferation and proteoglycan synthesis more than when compared to GF and GF/GlcN HCl. The synthesis of COL1 and COL2 was observed in all groups containing GF. CONCLUSION: GlcN HCl and GlcNAc increased cell growth and stimulated COL2 synthesis in long-time 3D culture. However, only GlcNAc added to GF improved proteoglycan synthesis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1481-1483
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• 1994

The dielectric and electrical properties of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3-BaTiO_3$ have been investigated. Perovskite crystalline phase of the specimens is confimed by XRD. The curie temperature decrease with increasing $BaTiO_3$ and hysteresis phenomena decrease with increasement of $BaTiO_3$. The strain vs. applied voltage characteristics exhibit nonlinear relationship and the specimen. of 0.9PMN-0.08PT-0.02BT shows the largest strain.