Chung Yuan Christian University

About: Chung Yuan Christian University is a education organization based out in Taoyuan City, Taiwan. It is known for research contribution in the topics: Membrane & Fuzzy logic. The organization has 9819 authors who have published 11623 publications receiving 213139 citations. The organization is also known as: Tiong-gôan-tāi-ha̍k & CYCU.

The antioxidant effects of quercetin metabolites on the prevention of high glucose-induced apoptosis of human umbilical vein endothelial cells.

Abstract: Diabetes mellitus is an important risk factor for CVD. A previous study showed that high glucose induced the apoptosis of human umbilical vein endothelial cells (HUVEC) via the sequential activation of reactive oxygen species, Jun N-terminal kinase (JNK) and caspase-3. The apoptosis cascade could be blocked by ascorbic acid at the micromolar concentration (100mM). In addition to ascorbic acid, quercetin, the most abundant dietary flavonol, has been recently actively studied in vascular protection effects due to its antioxidant effect at low micromolar concentrations (10‐50mM). Quercetin sulfate/glucuronide, the metabolite of quercetin in blood, however, has been rarely evaluated. In the present study, we investigated the effect of quercetin sulfate/glucuronide on the prevention of high glucose-induced apoptosis of HUVEC. HUVEC were treated with media containing high glucose (33mM) in the presence or absence of ascorbic acid (100mM) or quercetin sulfate/glucuronide (100nM, 300nM and 1mM). For the detection of apoptosis, a cell death detection ELISA assay was used. The level of intracellular H2O2 was measured by flow cytometry. JNK and caspase-3 were evaluated by a kinase activity assay and Western blot analysis. The results showed that high glucose-induced apoptosis was inhibited by quercetin sulfate/glucuronide in a dose-dependent manner. The effect of quercetin sulfate/glucuronide on H2O2 quenching, inhibition of JNK and caspase-3 activity at the nanomolar concentration (300nM) was similar to that of ascorbic acid at the micromolar concentration (100mM). The findings of the present study may shed light on the pharmacological application of quercetin in CVD. Quercetin metabolites: Glucose: Endothelial cells: Apoptosis: Reactive oxygen species: Jun N-terminal kinase: Caspase

A novel method to predict the pull-in voltage in a closed form for micro-plates actuated by a distributed electrostatic force

Abstract: This study is devoted to finding the precise pull-in voltage/position of a micro-device formed by two parallel charged plates Pull-in is a phenomenon where the electrostatic force induced by the applied voltage across two plates of the device exceeds the elastic, restoring force exerted by the deformed plates, leading to a contact between the two plates To offer a precise prediction of the pull-in, a dynamic model in the form of a partial differential equation (PDE) is established based on the equilibrium among plate flexibility, residual stress and distributed electrostatic forces The Galerkin method is employed to decompose the established PDE into discrete modal equations By considering lower order modes and solving them, one arrives at a prediction of plate deflection in terms of the applied bias voltage Approximating the solved deflection by a fifth-order series and full-order numerical integration, the pull-in position and voltage are successfully approximated The pull-in position in terms of center deflection of the deformed plate is found to be 48% of the air gap between the plates, which presents a better estimation than the commonly used one-third of the gap derived by all past studies based on a less realistic one-dimensional lump model A closed form of the pull-in voltage is derived to offer design guidelines for the device prior to production The aforementioned theoretical findings are finally validated by finite element and experimental studies on a MEMS device of parallel charged micro-plates designed and fabricated in the laboratory

Experimental evaluation of smart antenna system performance for wireless communications

Abstract: In wireless communications, smart antenna systems (or antenna arrays) can be used to suppress multipath fading with antenna diversity and to increase the system capacity by supporting multiple co-channel users in reception and transmission. This paper presents experimental results of diversity gain, interference cancellation, and mitigation of multipath fading obtained by using a smart antenna system in typical wireless scenarios. Also given are experimental results for the signal-to-interference ratio (SIR) of two moving users, comparing different beamforming algorithms in typical wireless scenarios. All of the experiments were performed using the 900-MHz smart antenna testbed at The University of Texas at Austin.