To release more flexibility for users to charge their portable devices, researchers have increasingly developed compact wireless power transfer (WPT) systems in recent years. Also, a dual-band WPT system is proposed to transfer power and signal simultaneously, enriching the system's functionality. Moreover, a stacked metasurface has recently been proposed for a single band near-field WPT system.
View Article and Find Full Text PDFGenerally, a conventional voltage doubler circuit possesses a large variation of its input impedance over the bandwidth, which results in limited bandwidth and low RF-dc conversion efficiency. A basic aspect for designing wideband voltage doubler rectifiers is the use of complex matching circuits to achieve decade and octave impedance and RF-dc conversion efficiency bandwidths. Still, the reported techniques till now have been accompanied by a large fluctuation of the RF-dc conversion efficiency over the operating bandwidth.
View Article and Find Full Text PDFConventional resonant inductive coupling wireless power transfer (WPT) systems encounter performance degradation while energizing biomedical implants. This degradation results from the dielectric and conductive characteristics of the tissue, which cause increased radiation and conduction losses, respectively. Moreover, the proximity of a resonator to the high permittivity tissue causes a change in its operating frequency if misalignment occurs.
View Article and Find Full Text PDFDegener Neurol Neuromuscul Dis
January 2014
Alzheimer's disease (AD) is the major cause of dementia in the elderly and an unmet clinical challenge. A variety of therapies that are currently under development are directed to the amyloid cascade. Indeed, the accumulation and toxicity of amyloid-β (Aβ) is believed to play a central role in the etiology of the disease, and thus rational interventions are aimed at reducing the levels of Aβ in the brain.
View Article and Find Full Text PDFBACE initiates the amyloidogenic processing of the amyloid precursor protein (APP) that results in the production of Aβ peptides associated with Alzheimer's disease (AD). Previous studies have indicated that BACE is elevated in the frontal cortex of AD patients. Golgi-localized γ-ear containing ADP ribosylation factor-binding proteins (GGA) control the cellular trafficking of BACE and may alter its levels.
View Article and Find Full Text PDFNeuregulin 1 (NRG1) is a susceptibility gene for schizophrenia. A decrease in NRG1-ErbB4 signalling has also been associated with the disease. β-amyloid precursor protein-cleaving enzyme (BACE1) processes type III NRG1 precursor, a major neuregulin variant expressed in the brain, to release NRG1 fragments that trigger signalling events and activation of neurotransmitter receptors.
View Article and Find Full Text PDFInt J Biochem Cell Biol
December 2010
β-Site APP-cleaving enzyme (BACE) is a membrane-bound aspartyl protease involved in the production of Alzheimer's disease (AD) Aβ amyloid peptides. This enzyme is ubiquitously expressed, with highest levels in the brain and pancreas. Its cellular trafficking is tightly controlled as it recycles between endosomes and trans-Golgi network.
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