Fu Alex - Academia.edu (original) (raw)

Papers by Fu Alex

Journal of Biological Chemistry, 2009

Notch and TGFβ play critical roles in endothelial-to-mesenchymal transition (EndMT), a process th... more Notch and TGFβ play critical roles in endothelial-to-mesenchymal transition (EndMT), a process that is essential for heart development. Previously we have shown that Notch and TGFβ signaling synergistically induce Snail expression in endothelial cells, which is required for EndMT in cardiac cushion morphogenesis. Here, we report that Notch activation modulates TGFβ signaling pathways in a receptor activated Smad (R-Smad)-specific manner. Notch activation inhibits TGFβ/Smad1 and TGFβ/Smad2 signaling pathways by decreasing the expression of Smad1 and Smad2 and their target genes. In contrast, Notch increases SMAD3 mRNA expression and protein half-life, and regulates the expression of TGFβ/Smad3 target genes in a gene-specific manner. Inhibition of Notch in the cardiac cushion of mouse embryonic hearts reduces Smad3 expression. Notch and TGFβ synergistically upregulate a subset of genes by recruiting Smad3 to both Smad and CSL binding sites and cooperatively inducing histone H4 acetylation. This is the first evidence that Notch activation affects R-Smad expression and that cooperative induction of histone acetylation at specific promoters underlies the selective synergy between Notch and TGFβ signaling pathways. http://www.jbc.org/cgi/

Surface Review and Letters, 2001

As the gate dielectric for ULSI MOS devices scales in the ultrathin regime, it is fabricated incr... more As the gate dielectric for ULSI MOS devices scales in the ultrathin regime, it is fabricated increasingly with silicon oxynitride instead of silicon dioxide films. One way to obtain silicon oxynitride films is the rapid thermal oxidation of silicon in NO (RTNO). Earlier RTNO growth studies were not sufficiently comprehensive as well as limited by temperature uncertainty and nonuniformity across the wafer. Using a state-of-the-art rapid thermal processing (RTP) system, RTNO growth characteristics at oxidation pressures of 100 and 760 Torr, oxidation temperatures from 900 to 1200°C and oxidation times from 0 to 480 s were obtained and investigated. Anomalies in the growth characteristics were observed. It was also demonstrated that secondary ion mass spectrometry (SIMS) using the MCs+ method could be used to accurately determine the depth distribution of N in ultrathin silicon oxynitride films.

The near-edge states and transition probabilities of free-standing and Ga_xIn_1-xP-embedded InP q... more The near-edge states and transition probabilities of free-standing and Ga_xIn_1-xP-embedded InP quantum dots are investigated using atomic screened pseudopotentials^1 and the folded spectrum method^2. The geometries and strain fields of the lattice-mismatched embedded dots are obtained by valence force field energy minimization. We find that: (i) Unlike the case of GaAs dots, the conduction band minimum (CBM) of free-standing InP dots is direct, Γ _1c-like state even for small dots. (ii) However, for Ga_xIn_1-xP-embedded InP dots, the CBM changes from a Γ _1c-like state to a X_1c-like state at a critical dot size. (iii) The critical dot size depends on the composition x of Ga_xIn_1-xP in the barrier. (iv) The size (D) dependence of the band gap of free-standing InP dots, Eg = 1.45 + 37.925/D^1.16, is significantly different from the predictions of effective-mass theory. [1] H. Fu and A. Zunger, Phys. Rev. B (in press). [2] L. W. Wang and A. Zunger, J. Chem. Phys. 100, 2394 (1994). Supported by BES/OER/DMS under contract No. DE-AC36-83-CH10093

Recent evidence suggests that functional diversity of vascular smooth muscle is produced in part ... more Recent evidence suggests that functional diversity of vascular smooth muscle is produced in part by a differential expression of ion channels. The aim of the present study was to examine the role of Ca 2ϩ -activated K ϩ channels (K Ca channels) in the expression of smooth muscle cell functional phenotype. We found that smooth muscle cells exhibiting a contractile function express predominantly large-conductance (Ϸ200 pS) K Ca (BK) channels. In contrast, proliferative smooth muscle cells express predominantly K Ca channels exhibiting a much smaller conductance (Ϸ32 pS). These channels are blocked by low concentrations of charybdotoxin (10 nmol/L) but, unlike BK channels, are insensitive to iberiotoxin (100 nmol/L). To determine the molecular identity of this K ϩ channel, we cloned a 1.9-kb cDNA from an immature-phenotype smooth muscle cell cDNA library. The cDNA contains an open reading frame for a 425 amino acid protein exhibiting sequence homology to other K Ca channels, in particular with mIK1 and hIK1. Expression in oocytes gives rise to a K ϩ -selective channel exhibiting intermediate-conductance (37 pS at Ϫ60 mV) and potent activation by Ca 2ϩ (K d 120 nmol/L). Thus, we have cloned and characterized the vascular smooth muscle intermediate-conductance K Ca channel (SMIK), which is markedly upregulated in proliferating smooth muscle cells. The differential expression of these K Ca channels in functionally distinct smooth muscle cell types suggests that K Ca channels play a role in defining the physiological properties of vascular smooth muscle. The full text of this article is available at http://www.circresaha.org. (Circ Res. 1999;85:e33-e43.)

Below you will find instructions on how to download and install Dallmeier's VMS to test with our ... more Below you will find instructions on how to download and install Dallmeier's VMS to test with our products for the City of Dreams opportunity. Becky and I discussed this test be ran from MegaLab APAC since the MegaLab HQ is booked for the next six weeks, and the two of you need to understand this software so you can help drive these projects with Cathy.

Journal of Biological Chemistry, 2009

Notch and TGFβ play critical roles in endothelial-to-mesenchymal transition (EndMT), a process th... more Notch and TGFβ play critical roles in endothelial-to-mesenchymal transition (EndMT), a process that is essential for heart development. Previously we have shown that Notch and TGFβ signaling synergistically induce Snail expression in endothelial cells, which is required for EndMT in cardiac cushion morphogenesis. Here, we report that Notch activation modulates TGFβ signaling pathways in a receptor activated Smad (R-Smad)-specific manner. Notch activation inhibits TGFβ/Smad1 and TGFβ/Smad2 signaling pathways by decreasing the expression of Smad1 and Smad2 and their target genes. In contrast, Notch increases SMAD3 mRNA expression and protein half-life, and regulates the expression of TGFβ/Smad3 target genes in a gene-specific manner. Inhibition of Notch in the cardiac cushion of mouse embryonic hearts reduces Smad3 expression. Notch and TGFβ synergistically upregulate a subset of genes by recruiting Smad3 to both Smad and CSL binding sites and cooperatively inducing histone H4 acetylation. This is the first evidence that Notch activation affects R-Smad expression and that cooperative induction of histone acetylation at specific promoters underlies the selective synergy between Notch and TGFβ signaling pathways. http://www.jbc.org/cgi/

Surface Review and Letters, 2001

As the gate dielectric for ULSI MOS devices scales in the ultrathin regime, it is fabricated incr... more As the gate dielectric for ULSI MOS devices scales in the ultrathin regime, it is fabricated increasingly with silicon oxynitride instead of silicon dioxide films. One way to obtain silicon oxynitride films is the rapid thermal oxidation of silicon in NO (RTNO). Earlier RTNO growth studies were not sufficiently comprehensive as well as limited by temperature uncertainty and nonuniformity across the wafer. Using a state-of-the-art rapid thermal processing (RTP) system, RTNO growth characteristics at oxidation pressures of 100 and 760 Torr, oxidation temperatures from 900 to 1200°C and oxidation times from 0 to 480 s were obtained and investigated. Anomalies in the growth characteristics were observed. It was also demonstrated that secondary ion mass spectrometry (SIMS) using the MCs+ method could be used to accurately determine the depth distribution of N in ultrathin silicon oxynitride films.

The near-edge states and transition probabilities of free-standing and Ga_xIn_1-xP-embedded InP q... more The near-edge states and transition probabilities of free-standing and Ga_xIn_1-xP-embedded InP quantum dots are investigated using atomic screened pseudopotentials^1 and the folded spectrum method^2. The geometries and strain fields of the lattice-mismatched embedded dots are obtained by valence force field energy minimization. We find that: (i) Unlike the case of GaAs dots, the conduction band minimum (CBM) of free-standing InP dots is direct, Γ _1c-like state even for small dots. (ii) However, for Ga_xIn_1-xP-embedded InP dots, the CBM changes from a Γ _1c-like state to a X_1c-like state at a critical dot size. (iii) The critical dot size depends on the composition x of Ga_xIn_1-xP in the barrier. (iv) The size (D) dependence of the band gap of free-standing InP dots, Eg = 1.45 + 37.925/D^1.16, is significantly different from the predictions of effective-mass theory. [1] H. Fu and A. Zunger, Phys. Rev. B (in press). [2] L. W. Wang and A. Zunger, J. Chem. Phys. 100, 2394 (1994). Supported by BES/OER/DMS under contract No. DE-AC36-83-CH10093

Recent evidence suggests that functional diversity of vascular smooth muscle is produced in part ... more Recent evidence suggests that functional diversity of vascular smooth muscle is produced in part by a differential expression of ion channels. The aim of the present study was to examine the role of Ca 2ϩ -activated K ϩ channels (K Ca channels) in the expression of smooth muscle cell functional phenotype. We found that smooth muscle cells exhibiting a contractile function express predominantly large-conductance (Ϸ200 pS) K Ca (BK) channels. In contrast, proliferative smooth muscle cells express predominantly K Ca channels exhibiting a much smaller conductance (Ϸ32 pS). These channels are blocked by low concentrations of charybdotoxin (10 nmol/L) but, unlike BK channels, are insensitive to iberiotoxin (100 nmol/L). To determine the molecular identity of this K ϩ channel, we cloned a 1.9-kb cDNA from an immature-phenotype smooth muscle cell cDNA library. The cDNA contains an open reading frame for a 425 amino acid protein exhibiting sequence homology to other K Ca channels, in particular with mIK1 and hIK1. Expression in oocytes gives rise to a K ϩ -selective channel exhibiting intermediate-conductance (37 pS at Ϫ60 mV) and potent activation by Ca 2ϩ (K d 120 nmol/L). Thus, we have cloned and characterized the vascular smooth muscle intermediate-conductance K Ca channel (SMIK), which is markedly upregulated in proliferating smooth muscle cells. The differential expression of these K Ca channels in functionally distinct smooth muscle cell types suggests that K Ca channels play a role in defining the physiological properties of vascular smooth muscle. The full text of this article is available at http://www.circresaha.org. (Circ Res. 1999;85:e33-e43.)

Below you will find instructions on how to download and install Dallmeier's VMS to test with our ... more Below you will find instructions on how to download and install Dallmeier's VMS to test with our products for the City of Dreams opportunity. Becky and I discussed this test be ran from MegaLab APAC since the MegaLab HQ is booked for the next six weeks, and the two of you need to understand this software so you can help drive these projects with Cathy.