Browsing by Author "Chang, Ting-Kuo"

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BMP-4 Induction of Arrest and Differentiation of Osteoblast-Like Cells via p21(CIP1) and p27(KIP1) Regulation
(2009-11-01)
Chang, Shun-Fu
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Chang, Ting-Kuo
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Peng, Hsin-Hsin
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Yeh, Yi-Ting
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Lee, Ding-Yu
Cell cycle regulation by differentiation signals is critical for eukaryote development. We investigated the roles of bone morphogenetic protein (BMP)-4, an important stimulator of osteoblast differentiation and bone formation, in regulating cell cycle distribution in four osteoblast-like cell lines and mouse primary osteoblasts, and the underlying mechanisms. In all cells used, BMP-4 induced G(0)/G(1) arrest. The molecular basis of the BMP-4 effect was analyzed, and the presentation on molecular mechanism is focused on human MG63 cells. BMP-4 induced p21(CIP1) and p27(KIP1) expressions and hence cell differentiation but had no effects on the expressions of cyclins A, B1, D1, and E, cyclin-dependent protein kinase-2, -4, and -6. Using specific small interfering RNA (siRNA), we found that BMP-4-induced G(0)/G(1) arrest, and p21(CIP1) and p27(KIP1) expressions were mediated by BMP receptor type IA (BMPRIA)-specific Sma- and Mad-related protein (Smad)1/5. BMP-4 induced transient phosphorylations of ERK; transfection of MG63 cells with ERK2, but not ERK1, -specific siRNA inhibited the BMP-4-induced responses in MG63 cells. Pretreatment of MG63 cells with Arg-Gly-Asp-Ser, which blocks the cell-extracellular matrix interaction, or transfection with beta(3) integrin-specific siRNA inhibited BMP-4-induced ERK and Smad1/5 phosphorylations. BMP-4 induced transient increases in associations of beta(3)-integrin with focal adhesion kinase and Shc, the dominant-negative mutants of which inhibited BMP-4-induced ERK and Smad1/5 phosphorylations. Our results indicate that BMP-4 induces G(0)/G(1) arrest and hence differentiation in osteoblast-like cells through increased expressions of p21(CIP1) and p27(KIP1), which are mediated by BMPRIA-specific Smad1/5. The extracellular matrix/beta(3) integrin/focal adhesion kinase/Shc/ERK2 signaling pathway is involved in these BMP-4-induced responses in osteoblast-like cells. (Molecular Endocrinology 23: 1827-1838, 2009)
Fabrication of location-controlled silicon crystal grains by combining excimer laser irradiation with nanometer-sized A-Si
(2007)
Tsai, Chun-Chien
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Chang, Ting-Kuo
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Chen, Hsiu-Hsin
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Chen, Bo-Ting
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Cheng, Huang-Chung
In this paper, location-controlled silicon crystal grains are fabricated by a novel excimer laser crystallization method. An array of 1.8-mu m-sized disk-liked grains are formed by this method, and the high-performance n-channel LTPS TFTs with field-effect-mobility reaching 308 cm(2)/Vs can be, fabricated owing to the artificially-controlled lateral grain growth. This position-manipulated silicon grains are essential to high performance and good uniformity thin film transistors.
Low temperature polycrystalline silicon thin film transistors fabricated by amorphous silicon spacer structure with pre-patterned TEOS oxide layer
(2005)
Cheng, Huang-Chung
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Tsai, Chun-Chien
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Lu, Jian-Hao
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Chang, Ting-Kuo
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Lin, Ching-Wei
In this paper, location-controlled grain growth with a-Si spacer structure was fabricated. Consequently, High-performance poly-Si TFTs with field-effect mobility exceeding 367 cm(2)/V-s and high device uniformity have been fabricated. The excellent electrical characteristics is attributed to large grain and grain boundary elimination in the channel region.
Periodically lateral silicon grains fabricated by excimer laser irradiation with a-Si spacers for LTPS TFTs
(2007)
Cheng, Huang-Chung
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Tsai, Chun-Chien
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Lu, Jian-Hao
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Chen, Hsu-Hsin
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Chen, Bo-Ting
Low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) with a periodic lateral silicon grain structure have been demonstrated to exhibit high-performance electrical characteristics via the amorphous silicon spacers above the amorphous silicon film crystallized with excimer laser. Amorphous silicon spacers allowed the bottom of the under-layered amorphous silicon film to serve as seed crystals. The periodic grain structure could be artificially controlled via the super lateral growth phenomenon during excimer laser irradiation. Consequently, such periodically large and lateral grains in the TFTs would achieve high field-effect-mobility of 298 cm(2)/V s, as compared with the conventional ones of 128 cm(2)/V s. In addition, the uniformity of device-to-device could be improved due to this location-manipulated lateral silicon grains. (c) 2006 The Electrochemical Society.
Polycrystalline silicon thin-film transistors with location-controlled crystal grains fabricated by excimer laser crystallization
(2007-11-12)
Tsai, Chun-Chien
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Lee, Yao-Jen
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Chiang, Ko-Yu
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Wang, Jyh-Liang
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Lee, I-Che
In this paper, location-controlled silicon crystal grains are fabricated by the excimer laser crystallization method which employs amorphous silicon spacer structure and prepatterned thin films. The amorphous silicon spacer in nanometer-sized width formed using spacer technology is served as seed crystal to artificially control superlateral growth phenomenon during excimer laser irradiation. An array of 1.8-mu m-sized disklike silicon grains is formed, and the n-channel thin-film transistors whose channels located inside the artificially-controlled crystal grains exhibit higher performance of field-effect-mobility reaching 308 cm(2)/V s as compared with the conventional ones. This position-manipulated silicon grains are essential to high-performance and good uniformity devices. (c) 2007 American Institute of Physics.