Chia-Chi Chang

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BACKGROUND Previous studies have reported several conflicting findings regarding neuropsychiatric symptoms when comparing patients with Alzheimer's disease (AD) and patients with vascular dementia (VaD). OBJECTIVES The purpose was to: (1) compare the prevalence of neuropsychiatric symptoms among patients with AD and VaD after controlling for demographic(More)
In this paper, we design and implement a WSN testbed with a distributed architecture. It allows researchers to submit their experiments and to retrieve the results from the central server. In the testbed, we also propose a software-based hardware-supported scheme to measure the energy consumption of running sensor nodes. And we compare our(More)
We have fabricated graphene-silicon Schottky diodes by depositing mechanically exfoliated graphene on top of silicon substrates. The resulting current-voltage characteristics exhibit rectifying diode behavior with a barrier energy of 0.41 eV on n-type silicon and 0.45 eV on p-type silicon at the room temperature. The I-V characteristics measured at 100,(More)
Hypoxia, a common environmental condition, influences cell signals and functions. Here, we compared the effects of hypoxia (1% oxygen) and normoxia (air) on chondrogenic differentiation of human mesenchymal stem cells (MSCs). For in vitro chondrogenic differentiation, MSCs were concentrated to form pellets and subjected to conditions appropriate for(More)
We report a systematic study of carrier dynamics in Al(x)Ga(1-x)As-passivated GaAs nanowires. With passivation, the minority carrier diffusion length (L(diff)) increases from 30 to 180 nm, as measured by electron beam induced current (EBIC) mapping, and the photoluminescence (PL) lifetime increases from sub-60 ps to 1.3 ns. A 48-fold enhancement in the(More)
A V-band fully integrated complementary push-push VCO is first presented in 0.18- /spl mu/m bulk CMOS technologies. Thin-film microstrip (TFMS) lines are utilized in the circuit to reduce the conductive substrate effect. In order to lower the phase noise, complementary cross-coupled pairs are used to generate negative conductance. The measured phase noise(More)
We apply immense strain to ultralong, suspended, single-walled carbon nanotubes while monitoring their Raman spectra. We can achieve strains up to 13.7 ± 0.3% without slippage, breakage, or defect formation based on the observation of reversible change in Raman spectra. This is more than twice that of previous observations. The rate of G band downshift with(More)