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Your search keyword '"Peh, W. Y. X."' showing total 4 results
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4 results on '"Peh, W. Y. X."'

3. A Wireless Multi-Channel Peripheral Nerve Signal Acquisition System-on-Chip

Author

Xin Yuan Thow, Khay-Wai Leong, Sanghoon Lee, Gil Gerald Lasam Gammad, Yong Ping Xu, Anh Tuan Do, Kian Ann Ng, Astrid Rusly, Wendy Yen Xian Peh, John S. Ho, Shih-Chiang Liu, Annarita Cutrone, Chao Yuan, Shih-Cheng Yen, Bin Zhao, Kai Voges, Gemma Taverni, Silvia Bossi, Ng, K. A., Yuan, C., Rusly, A., Do, A. -T., Zhao, B., Liu, S. -C., Peh, W. Y. X., Thow, X. Y., Voges, K., Lee, S., Gammad, G. G. L., Leong, K. -W., Ho, J. S., Bossi, S., Taverni, G., Cutrone, A., Yen, S. -C., and Xu, Y. P.

Subjects
low-noise amplifier, 02 engineering and technology, Signal, law.invention, law, Electroneurogram, input common-mode range, otorhinolaryngologic diseases, 0202 electrical engineering, electronic engineering, information engineering, neural prosthesi, Amplifier, System on a chip, low voltage, neural recording amplifier, Electrical and Electronic Engineering, signal acquisition, Physics, peripheral nerve signal, low power, business.industry, Noise (signal processing), CMOS, common-mode feedback (CMFB), common-mode rejection ratio (CMRR), neural prosthesis, peripheral nerve, 020208 electrical & electronic engineering, Electrical engineering, Capacitor, sense organs, Antenna (radio), business
Abstract

The adoption of chronic implantable peripheral nerve-based prosthetic devices is currently hampered by the lack of a highly integrated neural signal acquisition system-on-chip (SoC). We report a ten-channel peripheral nervous system (PNS) electroneurogram (ENG) signal acquisition SoC within an implantable package. Requiring only four off-chip capacitors, this SoC can be co-encapsulated with flexible nerve electrodes and a resonant coil antenna to form a 3.4 cm3 and 3.9 g implantable device for chronic ENG acquisition. This SoC is inductively powered and controlled through a resonant coil at 22 MHz and transmits the digitized neural signal through a near-infrared LED (NIR-LED). Fabricated in 0.18- $\mu \text{m}$ CMOS, each amplifier channel exhibits an input referred noise of 1.9 $\mu \text{V}_{\mathbf {rms}}$ and a noise efficiency factor (NEF) of 4.0 within the signal bandwidth of 5.5 kHz. Each amplifier channel within the SoC is digitized with 10-bit resolution at 17.5 ksps, and the total power consumption (SoC and NIR-LED) is 4.4 mW when the NIR-LED is driven at 3 Mb/s. An electrode impedance measurement circuit with $\text{M}\Omega $ is also incorporated in this SoC. This wireless, low noise ENG acquisition SoC package has been validated in vivo while implanted on a rodent to acquire ENG from its sciatic nerve.

Published
2019

4. Roles of intestinal glutamate dehydrogenase and glutamine synthetase in environmental ammonia detoxification in the euryhaline four-eyed sleeper, Bostrychus sinensis.

Author

Peh WY, Chew SF, Ching BY, Loong AM, and Ip YK

Subjects
Ammonia analysis, Ammonia toxicity, Ammonium Chloride metabolism, Ammonium Chloride toxicity, Animals, Enzyme Activation drug effects, Glutamic Acid metabolism, Liver chemistry, Liver enzymology, Muscle, Skeletal chemistry, Muscle, Skeletal enzymology, Seawater chemistry, Water Pollutants, Chemical analysis, Water Pollutants, Chemical toxicity, Water-Electrolyte Balance, Ammonia metabolism, Glutamate Dehydrogenase metabolism, Glutamate-Ammonia Ligase metabolism, Intestines enzymology, Perciformes metabolism, Water Pollutants, Chemical metabolism
Abstract

This study aimed to examine the hypothesis that intestinal glutamate dehydrogenase (GDH) and glutamine synthetase (GS) could be involved in ammonia detoxification in the euryhaline Bostrychus sinensis exposed to ammonia in a hyperosmotic environment, whereby drinking was essential for osmoregulation. Our results indicate that there was a significant increase in ammonia content in the intestine of B. sinensis exposed to 15 mmol l(-1) NH(4)Cl in seawater (pH 7.0) for 6 days. There were also significant increases in the amination and deamination activities and protein abundance of intestinal GDH. The GDH amination/deamination ratio remained unchanged, indicating that there could be increases in the turnover of glutamate. However, the difference between the amination and deamination activities increased 2-fold, implying that there could be an increase in glutamate formation in the intestine. Since the intestinal glutamate content remained unchanged, excess glutamate formed might have been channeled into other amino acids and/or transported to other organs. Indeed, the intestinal glutamine content increased significantly by 2-fold, with a significant increase in the activity and protein abundance of intestinal GS. Since the magnitude of glutamine accumulation in the intestine was lower than those in liver and muscle, which lacked changes in GDH activities, intestinal glutamate could have been shuttled to liver and muscle to facilitate increased synthesis of glutamine therein. By contrast, when fish were exposed to a much higher concentration (30 mmol l(-1)) of NH(4)Cl in 5 per thousand water (pH. 7.0), the magnitude of increase in ammonia content in the intestine was less prominent, and there were no changes in activities and kinetic properties of intestinal GDH. Therefore, it can be concluded that the intestine of B. sinensis was involved in the defense against ammonia toxicity during exposure to ammonia in a hyperosmotic medium., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

Published
2010
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