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The thermal stabilities of MOSFETs with high-K gate dielectric on both Si/ultrathin Ge/Si (SGS) and strained Si on relaxed Si1?xGex (SS) substrates are studied. Though an initial drivability enhancement of 29% is shown for the SGS nMOSFET, annealing at 750 ?C has resulted in drastic degradation in its drivability, lowering its Id beyond that of the Si nMOSFETs by 52%. Despite lowering in the junction leakage current, Ge diffusion to the near surface region, indicated by Vth and surface roughness change, degrades the SGS device performance significantly. For the SS nMOSFET, drivability varies with Ge content, whereby a maximum of 86% improvement over that of the Si nMOSFET is observed for 30% Ge. In contrast to the SGS nMOSFET, the SS nMOSFET is able to retain its Id improvement, even after annealing at 950 ?C, as the in-plane tensile strain is preserved. Ge diffusion to the surface does not affect the device significantly, as the strained Si thickness is about 10 nm compared to a Si cap thickness of only 1.5 nm for the SGS substrate.

Diabetic foot ulcers often pose a difficult problem for health care professionals because of the defects associated with fibroblast functioning. Although there has been much interest recently in the use of topical growth factors for the treatment of diabetic foot ulcers, the effects are generally not very dramatic. Cryopreserved fibroblast implants, which are able to adjust to a wound's environment and provide the desired growth factors and other substances that may be lacking in a chronic wound, represent an exciting development and a major advance. These products may well provide growth factors in the right concentration and in the right sequence, something that has proved difficult to achieve with the topical application of recombinant growth factors. However, cell activities are impaired by cryopreservation. The purpose of this study was to assess the effects of fresh human allogeneic fibroblast grafting for the treatment of diabetic foot ulcers. Eight patients with diabetic foot ulcers ranging from 6 to 17 weeks in duration were treated. The size of the wounds ranged from 2.0 to 6.0 cm2, with three patients exhibiting exposed bones. A history of diabetic foot ulcers was present in five patients. Human dermal fibroblasts from healthy teenagers were cultured in Dulbecco's modified Eagle medium/Ham's F-12 supplemented with 10% autologous serum. The cultured cells were applied over the wounds immediately after debridement; fibrin was used as a cell carrier. A dressing was then applied with Tegaderm and kept moist until healing was complete. The progress and time for complete wound closure and patient satisfaction were assessed, with follow-up time ranging from 6 to 18 months. Complete wound healing occurred in all patients. Eleven to 21 days were needed for complete reepithelization of the wound, and no clinical or laboratory abnormalities were noted. Patient satisfaction was also very positive. In this study, the use of fresh human fibroblast allografts was found to be a safe and effective treatment for diabetic foot ulcers.

We propose a novel approach to engineering floating gates (FGs) of flash memory cells, namely, carbon incorporation into polysilicon FGs. This technique demonstrated an improvement in retention and a larger program/erase Vt window, particularly for smaller capacitance coupling ratio cells, which is important for future scaled flash memory cells.

Inhibition of growth in mammalian cells in response to damage or stress is known as cellular senescence. Increasing evidence suggests that double-strand breaks (DSB) commonly mediate cellular senescence. Recently, radiation exposure has been reported to induce premature senescence.We investigated whether ionizing radiation (IR) at 4 Gy induces cellular senescence with DNA damage response in human umbilical vein endothelial cells (HUVEC). To determine alterations in gene expression on IR exposure, we have developed a DNA microarray analysis system that contains genes known to be involved in replicative senescence.The damage by IR exposure is shown to result in a variety of senescence-like phenotypes such as changes in cell morphology, decrease in cell proliferation, increase in senescence- associated β-galactosidase (SA-β-gal) staining, and suppression of angiogenic activity. Moreover, the expression levels of several genes associated with cell cycle regulation are remarkably increased in IR-exposed endothelial cells. We found that IGFBP5 (insulin-like growth factor binding protein 5), PLAT (plasminogen activator), SNAI2 (snail homolog 2), JAG1 (jagged 1), SPRY4 (Sprouty homolog 4), and CD44 were upregulated, whereas CFB (complement factor B), VCAM1 (vascular cell adhesion molecule 1), AQP1 (aquaporin 1), LOXL1 (lysyl oxidase-like 1), and RBPMS (RNA-binding protein with multiple splicing) were down- regulated in both radiation-damaged and old cells.These results imply that the IR-induced phenotype may be enhanced by alterations in genes associated with senescence.

Interferon-gamma (IFNγ) is a cytokine with roles in immune responses as well as in tumor control. Interferon is often used in cancer treatment together with other therapies. Here we report a novel approach to enhancement of cancer cell killing by combined treatment of IFNγ with ionizing radiation. We found that IFNγ treatment alone in HeLa cells induced phosphorylation of Chk1 in a time- and dose-dependent manner, and resulted in cell arrest. Moreover IFNγ treatment was correlated with attenuation of Chk1 as the treatment shortened protein half-life of Chk1. As Chk1 is an essential cell cycle regulator for viability after DNA damage, attenuation of Chk1 by IFNγ pre-treatment in HeLa cells resulted in increased cell death following ionizing radiation about 2-folds than ionizing radiation treatment alone whereas IFNγ treatment alone had little effect on cell death. X-linked inhibitor of apoptosis-associated factor 1 (XAF1), an IFN-induced gene, seems to partly regulate IFNγ-induced Chk1 destabilization and radiation sensitivity because transient depletion of XAF1 by siRNA prevented IFNγ-induced Chk1 attenuation and partly protected cells from IFNγ-enhanced radiation cell killing. Therefore the results provide a novel rationale to combine IFNγ pretreatment and DNA-damaging anti-cancer drugs such as ionizing radiation to enhance cancer cell killing.

Identification of genes that modulate radiation sensitivity provides important tools to study cellular responses to ionizing radiation. We combined DNA microarrays and viability assays to identify modulators of radiation sensitivity in A549 lung cancer cells. Up-regulated genes were selected from microarray experiments and RNA expression levels were confirmed by real-time RT-PCR analysis. Cell viability assays such as clonogenic assay, MTT and FACS analysis of cell death, identified the ELAVL4 gene as a novel modulator of radiation sensitivity. ELAVL4 expression was induced following ionizing irradiation. Depletion of the ELAVL4 gene increased radiation sensitivity of A549 cells as shown by decreased surviving cell fraction following irradiation in clonogenic assay. Enhanced radiation sensitivity of ELAVL4-depleted cells was attributable to decreased cell proliferation as well as increased apoptotic cell death following irradiation. Thus the endogenous function of ELAVL4 in relation to radiation sensitivity might be the regulation of cell proliferation and death. This approach to identification of modulators for radiation sensitivity has several advantages in terms of functional selectivity, stringency and time. Further analysis of the modulators should find potential use in the application of radiation biomarkers as well as modulators of cellular radiation responses.

The radiosensitizing activity of celastrol, a quinone methide triterpene was examined. We found that celastrol treatment of the NCI-H460 lung cancer cell line increased radiation-induced cell killing. The increased radiosensitivity was correlated with decreased levels of Hsp90 clients, such as EGFR, ErbB2 and survivin as well as with increased p53 expression. Celastrol inhibited the ATP-binding activity of Hsp90. Furthermore, celastrol treatment dissociated an Hsp90 client protein, EGFR, and this in turn resulted in degradation of the client protein. These results were not observed with another structurally similar triterpenoid, 6β-acetonyl-22β-hydroxytingenol (TG), suggesting that a specific structural feature of the triterpenoid is required for radiosensitization. Moreover celastrol treatment increased p53 levels by phosphorylating Ser15 and Ser20 residues as well as by inhibiting its proteasomal degradation. Celastrol may be considered an effective radiosensitizer acting as an inhibitor of Hsp90 and a p53 activator. The two activities could be applicable to a broad range of cancer cells with either wild-type or mutant p53 because either activity could be effective for the enhancement of radiation cell killing. Further analysis with other triterpenoids should identify the functional moiety of the structure and additional candidates for effective radiosensitizers, which can be used in combined radiotherapy.

In this paper, we propose an adaptive digital pre-distortion (DPD) linearization based on an affine projection (AP) algorithm for WCDMA power amplifier applications. The performance of the affine projection algorithm is compared with the least-mean-square (LMS) algorithm and recursive-least-square (RLS) algorithm, respectively. From the compared results, the AP algorithm has the advantage of more efficient computational complexity than the other algorithms and also the convergence speed of the AP algorithm is faster than that of the LMS algorithm. An affine projection algorithm based DPD has been simulated and compared with a DPD using LMS and RLS algorithms, respectively. From the simulation results, the AP based DPD has achieved −62.5 dBc adjacent channel leakage ratio (ACLR) at the average output power of 44.7 dBm of power amplifier for WCDMA 1-FA test signal.

The expression of glutathione-S-transferase (GST) fusion protein is extensively utilized in the study of protein-protein interactions. In the commonly used purification method, the overexpressed GST fusion protein is bound to the glutathione (GSH)-coupled resins via affinity chromatography, and then eluted by an excessive quantity of reduced GSH. However, this technique has certain limitations, such as low product purity, retention of GSH in the sample, as well as relatively high cost. To overcome these limitations, in this study, elution buffer containing 2% formic acid was utilized rather than GSH to elute the GST-fusion protein, and thereafter the acidic samples were neutralized using collecting buffer. By using this method, highly purified GST-cyclophilin A (CypA) fusion protein was obtained, without affecting the structural and functional characteristics such as PPIase and chaperone activities. Moreover, the procedure is also cost-effective, due to the low cost of formic acid as compared with GSH.

A novel fusion memory is proposed as a new paradigm of silicon based memory technology. An O/N/O gate dielectric and a floating body are combined with a FinFET, and the non-volatile memory (NVM) and high speed capacitorless 1T-DRAM are performed in a single transistor. A nitride trap layer is used as an electron storage node for NVM, and hetero-epitaxially grown Si/Si1-xGex energy band engineered bulk substrates allow excess hole storage for 1T-DRAM. Highly reliable 1T-DRAM and NVM are demonstrated.

A FinFET-based unified-RAM (URAM) using the band offset of Si/SiC is demonstrated for the fusion of a non-volatile memory (NVM) and capacitorless 1T-DRAM operation. An oxide/nitride/oxide (O/N/O) gate dielectric and a floating body caused by the band offset are combined in a bulk FinFET to allow two memory operations in a single transistor. The device is fabricated on an epitaxially grown Si/SiC substrate and its process is fully compatible with a conventional bulk FinFET SONOS. Highly reliable NVM and high speed 1T-DRAM operation are confirmed in a single URAM cell.

We reported previously that endogenous reactive oxygen species (ROS) function as myogenic signaling molecules. It has also been determined that excess ROS induce electrophile-response element (EpRE)-driven gene expression via activation of nuclear factor erythroid 2-related factor 2 (Nrf2). Nonetheless, the relationship between the metabolism of ROS (eg, H(2)O(2)) through glutathione (GSH) up-regulation, GSH-dependent reduction of H(2)O(2), and Nrf2-dependent gene regulation is not well established. Therefore, we attempted to determine whether H(2)O(2) controls the intracellular GSH redox state via the Nrf2-glutamate-cysteine ligase (GCL)/glutathione reductase (GR)-GSH signaling pathway. In our experiments, enhanced H(2)O(2) generation was accompanied by an increase in both total GSH levels and the GSH/GSSG ratio during muscle differentiation. Both GCL and GR transcriptional expression levels were markedly increased during muscle differentiation but reduced by catalase treatment. Nrf2 protein expression and nuclear translocation increased during myogenesis. The inhibition of GCL, GR, and Nrf2 both by inhibitors and by RNA interference blocked muscle differentiation. Phosphatidylinositol 3-kinase regulated the expression of the GCL C (a catalytic subunit) and GR genes via the induction of Nrf2 nuclear translocation and expression. In conclusion, endogenous H(2)O(2) generated during muscle differentiation not only functions as a signaling molecule, but also regulates the GSH redox state via activation of the Nrf2-GCL/GR-GSH signaling pathway downstream of phosphatidylinositol 3-kinase.

Although the RhoA/Rho kinase (RhoA/ROK) pathway has been extensively investigated, its roles and downstream signaling pathways are still not well understood in myogenic processes. Therefore, we examined the effects of RhoA/ROK on myogenic processes and their signaling molecules using H9c2 and C2C12 cells. Increases in RhoA/ROK activities and serine phosphorylation levels of insulin receptor substrate (IRS)-1 (Ser307 and Ser636/639) and IRS-2 were found in proliferating myoblasts, whereas IRS-1/2 tyrosine phosphorylation and phosphatidylinositol (PI) 3-kinase activity increased during the differentiation process. ROK strongly bound to IRS-1/2 in proliferation medium but dissociated from them in differentiation medium (DM). ROK inactivation by a ROK inhibitor, Y27632, or a dominant-negative ROK, decreased IRS-1/2 serine phosphorylation with increases in IRS-1/2 tyrosine phosphorylation and PI 3-kinase activity, which led to muscle differentiation even in proliferation medium. Inhibition of ROK also enhanced differentiation in DM. ROK activation by a constitutive active ROK blocked muscle differentiation with the increased IRS-1/2 serine phosphorylation, followed by decreases in IRS-1/2 tyrosine phosphorylation and PI 3-kinase activity in DM. Interestingly, fibroblast growth factor-2 added to DM also blocked muscle differentiation through RhoA/ROK activation. Fibroblast growth factor-2 blockage of muscle differentiation was reversed by Y27632. Collectively, these results suggest that the RhoA/ROK pathway blocks muscle differentiation by phosphorylating IRS proteins at serine residues, resulting in the decreased IRS-1/2 tyrosine phosphorylation and PI 3-kinase activity. The absence of the inhibitory effects of RhoA/ROK in DM due to low concentrations of myogenic inhibitory growth factors seems to allow IRS-1/2 tyrosine phosphorylation, which stimulates muscle differentiation via transducing normal myogenic signaling.

Role of c-Src in muscle differentiation has been controversial. Here, we investigated if c-Src positively or negatively regulates muscle differentiation, using H9c2 and C2C12 cell lines. Inhibition of c-Src by treatment with PP1 and SU6656, pharmacologic inhibitors of Src family kinases, or by expression of a dominant negative c-Src, all induced muscle differentiation in proliferation medium (PM). In differentiating cells in differentiation medium (DM), c-Src activity gradually decreased and reached basal level 3 days after induction of differentiation. Inhibition of c-Src suppressed Raf/MEK/ERK pathway but activated p38 MAPK. Inhibition of p38 MAPK did not affect c-Src activity in PM. However, it reactivated Raf/MEK/ERK pathway in c-Src-inhibited cells regardless of PM or DM. Concomitant inhibition of c-Src and p38 MAPK activities blocked muscle differentiation in both media. In conclusion, suppression of c-Src activity stimulates muscle differentiation by activating p38 MAPK uni-directionally.

Cyclosporin A (CsA) is a potent immunosuppressive agent, and can cause severe adverse effects including nephrotoxicity partly due to generation of reactive oxygen species (ROS). Glucocorticoids, which are widely used in combination with CsA, have been shown to reduce oxidative injuries in various cells, but its mechanism is not understood well. To investigate the effects of prednisolone (Pd) on CsA-induced cellular damage and ROS generation in Madin-Darby canine kidney (MDCK) tubular epithelial cells, cells were treated with CsA, CsA plus Pd, or CsA plus vitamin E. Pretreatment with Pd protected cells from CsA-induced apoptosis but not from G(0)/G(1) cell cycle arrest even at its maximal protective concentration (30 microM), whereas vitamin E almost completely inhibited both CsA-induced apoptosis and cell cycle arrest at 1 microM concentration. In addition, Pd reduced the amount of CsA-induced ROS and showed partly restored catalase which was down-regulated by 10 microM CsA at both the mRNA and protein levels. Vitamin E completely abolished CsA-induced ROS generation and catalase attenuation at 10 microM concentration. Finally, the effects of 1 microM vitamin E on CsA-induced ROS and apoptosis as well as cell cycle arrest were similar to those of 30 microM Pd. We conclude that, in MDCK cells, Pd protects against CsA-induced cytotoxicity by suppressing ROS generation, although its protective effect is weaker than that of vitamin E.

A GaAs defect-free epitaxial layer has been grown on Si via a Ge concentration graded SiGe on insulator (SGOI) for application in high channel-mobility metal-oxide-semiconductor field effect transistor. The SGOI layer, 42nm thick, serves as the compliant and intermediate buffer to reduce the lattice and thermal expansion mismatches between Si and GaAs. A modified two-step Ge condensation technique achieves the surface Ge concentration in SGOI as high as 71%. It is also found that low-temperature migration enhanced epitaxy during the initial GaAs nucleation on the SGOI surface is critical to obtain a device quality GaAs layer by epitaxial growth.

A novel fabrication technique to grow device quality GaAs on Si substrate is proposed using thin graded SiGe-on-insulator (SGOI) substrate. Combination of low-temperature GaAs molecular beam epitaxy (MBE) growth technique, low-temperature GaAs migration enhanced epitaxy (MEE) technique, and modified two-step Ge condensation technique has demonstrated successful growth of 10-nm GaAs layer grown on a tensile strained 42-nm graded SGOI layer.