• BMB Reports
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• v.54 no.6
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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.

• Proceedings of the KIEE Conference
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• 1995.07c
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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.

• Proceedings of the KIEE Conference
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• 1993.07b
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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.

• Proceedings of the KIEE Conference
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• 1997.07d
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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.

• Genomics & Informatics
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• v.12 no.4
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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.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.9-12
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• 1985

As a part of the host cell development for a amplified recombinant trp operon, $aroP^-$ mutation was introduced in a E. coli host strain. $aroP^-$ mutation was induced by transposon Tn10 and transduced into the E. coli host cell by bacteriophage P1Kc. The effect of $aroP^-$ mutation on the excretion of tryptophan in E. coli $trpR^{-ts}/ColE_1 -trp^+$ cells was investigated. Mutant lacking the general aromatic transport system was resistant to ${\beta}-2-thienylalanine\;(2{\times}10^{-4}\;M)$, p-fluorophenylalanine $(2{\times}10^{-4}M)$, or 5-methyltryptophan $(2{\times}10^{-4}\;M.)[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain was reduced considerably as compared with $aroP^+$ counterpart. The rate of $[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain treated with $NaN_3(3{\times}10^{-2}\;M)$ was much less affected than that of $aroP^+$ counterpart. The $aroP^-$ transductants increased the tryptophan excretion from E. coli $trpR^{-ts}/ColE_1 -trp^+$ four times more than $aroP^+$ counterpart.

• Proceedings of the KIEE Conference
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• 1996.07a
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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.

• Proceedings of the KIEE Conference
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• 1994.07b
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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.

• Tissue Engineering and Regenerative Medicine
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• v.15 no.6
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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.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1621-1623
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• 1996

The dielectric and polarizable properties of 0.85Pb$Mg_{1/3}Nb_{2/3}$)$O_3$-$0.125PbTiO_3$-$0.25BaTiO_3$ Ceramics have been investigated as a addition of the amount of $La_{2}O_{3}$($0{\leq}x{\geq}0.05$). The Temperature-dependant electrostictive characteristics of 0.85PMN-0.125PT-0.25BT relaxor ferroelectic system were improved by enhencing the extent of the diffuse phase transition(DPT). This was achieved using PMN-PT-BTceramics by the partial substitution of La at the Pb site. The curie temperature and the maximum dielectic permittivity decreased by substituting $La_{2}O_{3}$ and the electic field-related hysteresis phenomena decreased with increasing $La_{2}O_{3}$ substitution amount. It is showed decreasing in induced strain for electric field with increasing $La_{2}O_{3}$ substitution.