Browsing by Author "Lee, Chien-Hsing"

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High-Reliability Dynamic-Threshold Source-Side Injection for 2-Bit/Cell With MLC Operation of Wrapped Select-Gate SONOS in NOR-Type Flash Memory
(2010-09-01)
Wang, Kuan-Ti
;
Chao, Tien-Sheng
;
Wu, Woei-Cherng
;
Yang, Wen-Luh
;
Lee, Chien-Hsing
For the first time, a high-performance (tau(PGM) = 200 ns/tau(ERS) = 5 ms) cell with superior reliability characteristics is demonstrated in a NOR-type architecture, using dynamic-threshold source-side injection (DTSSI) in a wrapped select-gate silicon-oxide-nitride-oxide-silicon memory device, with multilevel and 2-bit/cell operation. Using DTSSI enables easy extraction of the multilevel states with a tight V(TH) distribution, a nearly negligible second-bit effect, superior endurance characteristics, and good data retention.
High-Speed Multilevel Wrapped-Select-Gate SONOS Memory Using a Novel Dynamic Threshold Source-Side-Injection (DTSSI) Programming Method
(2009-06-01)
Wang, Kuan-Ti
;
Chao, Tien-Sheng
;
Wu, Woei-Cherng
;
Chiang, Tsung-Yu
;
Wu, Yi-Hong
A. high programming speed with a low-power-consumption wrapped-select-gate poly-Si-oxide-nitride-oxide-silicon memory is successfully demonstrated using the novel dynamic threshold source-side-injection programming technique. The select gate embedded in such particular memory structure acts like a dynamic MOSFET resulting in programming current (I(PGM)) that can be enhanced in this DT mode, easily attaining a high programming speed of about 100 ns. It still doubles the memory density by achieving the 2-bit/cell operation with MLC under DT mode.
Highly reliable multilevel and 2-bit/cell operation of wrapped select gate (WSG) SONOS memory
(2007-03-01)
Wu, Woei-Cherng
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Chao, Tien-Sheng
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Peng, Wu-Chin
;
Yang, Wen-Luh
;
Wang, Jer-Chyi
In this letter, high-performance and reliable wrapped select gate (WSG) polysilicon-oxide-nitride-oxide-silicon (SONOS) memory cells with multilevel and 2-bit/cell operation have been successfully demonstrated. The multilevel storage is easily obtained with fast program/erase speed (10 mu s/5 ms) and low programming current (3.5 mu A) for our WSG SONOS by a source-side injection. Besides the excellent reliability properties of our multilevel WSG-SONOS memory including unconsidered gate and drain disturbance, long charge retention (> 150 degrees C) and good endurance (> 10(4)) are also presented. This novel WSG-SONOS memory with a multilevel and 2-bit/cell operation can be used in future high-density and high-performance memory application.
Optimized ONO thickness for multi-level and 2-bit/cell operation for wrapped-select-gate (WSG) SONOS memory
(2008-01-01)
Wu, Woei-Cherng
;
Chao, Tien-Sheng
;
Peng, Wu-Chin
;
Yang, Wen-Luh
;
Chen, Jian-Hao
In this paper, highly reliable wrapped-select-gate (WSG) silicon-oxide-nitride-oxide-silicon (SONOS) memory cells with multi-level and 2-bit/cell operation have been successfully demonstrated. The source-side injection mechanism for WSG-SONOS memory with different ONO thickness was thoroughly investigated. The different programming efficiencies of the WSG-SONOS memory under different ONO thicknesses are explained by the lateral electrical field extracted from the simulation results. Furthermore, multi-level storage is easily obtained, and good V(TH) distribution presented, for the WSG-SONOS memory with optimized ONO thickness. High program/erase speed (10 mu s/5 ms) and low programming current (3.5 mu A) are used to achieve the multi-level operation with tolerable gate and drain disturbance, negligible second-bit effect, excellent data retention and good endurance performance.
Pheophytin a Inhibits Inflammation via Suppression of LPS-Induced Nitric Oxide Synthase-2, Prostaglandin E2, and Interleukin-1 beta of Macrophages
(2014-12-01)
Lin, Chun-Yu
;
Lee, Chien-Hsing
;
Chang, Yu-Wei
;
Wang, Hui-Min
;
Chen, Chung-Yi
Inflammation is a serious health issue worldwide that induces many diseases such as sepsis. There has been a vast search for potentially effective drugs to decrease mortality from sepsis. Pheophytin a is a chlorophyll-related compound derived from green tea. We found that pre-treatment with pheophytin a suppressed lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2), and interleukin-1 beta in RAW 264.7 macrophages. NO synthase-2 (NOS2) and cyclooxygenase-2 (COX-2) expression levels were repressed by pre-treatment with pheophytin a at both the transcriptional and translational levels. Pheophytin a inhibited NOS2 promoter activity, but not its mRNA stability, through extracellular signal-regulated kinase (ERK1/2). This suppression was reversed by ERK1/2 inhibitor (U0126). Pheophytin a reduced signal transducers and activators of transcription 1 (STAT-1) activation, without an obvious influence on activator protein-1 (AP-1) and nuclear factor kappa B (NF-kappa B). These results suggest that pheophytin a functions by down-regulating the transcriptional levels of inflammatory mediators and blocking the ERK and STAT-1 pathways.
Phomaketide A Inhibits Lymphangiogenesis in Human Lymphatic Endothelial Cells
(2019-04-01)
Tai, Huai-Ching
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Lee, Tzong-Huei
;
Tang, Chih-Hsin
;
Chen, Lei-Po
;
Chen, Wei-Cheng
Lymphangiogenesis is an important biological process associated with cancer metastasis. The development of new drugs that block lymphangiogenesis represents a promising therapeutic strategy. Marine fungus-derived compound phomaketide A, isolated from the fermented broth of Phoma sp. NTOU4195, has been reported to exhibit anti-angiogenic and anti-inflammatory effects. However, its anti-lymphangiogenic activity has not been clarified to date. In this study, we showed that phomaketide A inhibited cell growth, migration, and tube formation of lymphatic endothelial cells (LECs) without an evidence of cytotoxicity. Mechanistic investigations revealed that phomaketide A reduced LECs-induced lymphangiogenesis via vascular endothelial growth factor receptor-3 (VEGFR-3), protein kinase C (PKC), and endothelial nitric oxide synthase (eNOS) signalings. Furthermore, human proteome array analysis indicated that phomaketide A significantly enhanced the protein levels of various protease inhibitors, including cystatin A, serpin B6, tissue factor pathway inhibitor (TFPI), and tissue inhibitor matrix metalloproteinase 1 (TIMP-1). Importantly, phomaketide A impeded tumor growth and lymphangiogenesis by decreasing the expression of LYVE-1, a specific marker for lymphatic vessels, in tumor xenograft animal model. These results suggest that phomaketide A may impair lymphangiogenesis by suppressing VEGFR-3, PKC, and eNOS signaling cascades, while simultaneously activating protease inhibitors in human LECs. We document for the first time that phomaketide A inhibits lymphangiogenesis both in vitro and in vivo, which suggests that this natural product could potentially treat cancer metastasis.
Physical Mechanism of High-Programming-Efficiency Dynamic-Threshold Source-Side Injection in Wrapped-Select-Gate SONOS for NOR-Type Flash Memory
(2009-11-01)
Wang, Kuan-Ti
;
Chao, Tien-Sheng
;
Chiang, Tsung-Yu
;
Wu, Woei-Cherng
;
Kuo, Po-Yi
For the first time, a programming mechanism for conventional source-side injection (SSI) (normal mode), substrate-bias enhanced SSI (body mode), and dynamic-threshold SSI (DTSSI) (DT mode) of a wrapped-select-gate SONOS memory is developed with 2-D Poisson equation and hot-electron simulation and programming characteristic measurement for NOR Flash memory. Compared with traditional SSI, DTSSI mechanisms are determined in terms of lateral acceleration electric field and programming current (I(PGM)) in the neutral gap region, resulting in high programming efficiency. Furthermore, the lateral electric field intersects the vertical electric field, indicating that the main charge injection point is from the end edge of the gap region close to the word gate.
ZnO Nanoparticles Induced Caspase-Dependent Apoptosis in Gingival Squamous Cell Carcinoma through Mitochondrial Dysfunction and p70S6K Signaling Pathway
(2020-03-01)
Wang, Shih-Wei
;
Lee, Chien-Hsing
;
Lin, Ming-Shen
;
Chi, Chih-Wen
;
Chen, Yu-Jen
Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in sunscreens, food additives, pigments, rubber manufacture, and electronic materials. Several studies have shown that ZnO-NPs inhibit cell growth and induce apoptosis by the production of oxidative stress in a variety of human cancer cells. However, the anti-cancer property and molecular mechanism of ZnO-NPs in human gingival squamous cell carcinoma (GSCC) are not fully understood. In this study, we found that ZnO-NPs induced growth inhibition of GSCC (Ca9-22 and OECM-1 cells), but no damage in human normal keratinocytes (HaCaT cells) and gingival fibroblasts (HGF-1 cells). ZnO-NPs caused apoptotic cell death of GSCC in a concentration-dependent manner by the quantitative assessment of oligonucleosomal DNA fragmentation. Flow cytometric analysis of cell cycle progression revealed that sub-G1 phase accumulation was dramatically induced by ZnO-NPs. In addition, ZnO-NPs increased the intracellular reactive oxygen species and specifically superoxide levels, and also decreased the mitochondrial membrane potential. ZnO-NPs further activated apoptotic cell death via the caspase cascades. Importantly, anti-oxidant and caspase inhibitor clearly prevented ZnO-NP-induced cell death, indicating the fact that superoxide-induced mitochondrial dysfunction is associated with the ZnO-NP-mediated caspase-dependent apoptosis in human GSCC. Moreover, ZnO-NPs significantly inhibited the phosphorylation of ribosomal protein S6 kinase (p70S6K kinase). In a corollary in vivo study, our results demonstrated that ZnO-NPs possessed an anti-cancer effect in a zebrafish xenograft model. Collectively, these results suggest that ZnO-NPs induce apoptosis through the mitochondrial oxidative damage and p70S6K signaling pathway in human GSCC. The present study may provide an experimental basis for ZnO-NPs to be considered as a promising novel anti-tumor agent for the treatment of gingival cancer.