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The pathogenesis of Alzheimer's disease (AD) mainly includes the decrease of neurons and synapses, the deposition of the extracellular β⁃ amyloid protein (Aβ), the formation of neuritic plaques (NPs) and neurofibrillary tangles (NFTs) caused by intracellular tau protein hyperphosphorylation. NPs and NFTs are closely related to the brain cholesterol homeostasis imbalance, suggesting that normal brain cholesterol homeostasis may play a decisive role in the development of AD. This paper reviews the molecular regulation mechanism of brain cholesterol homeostasis imbalance in AD.

A capacitor system based on a Terfenol-D rod and an electret film has been proposed. We used the traditional dynamic measurement to investigate the magnetoelectric effect of the system at the frequency of 50 kHz. The results show that the ME coefficient of the system is significantly affected by the DC bias magnetic field. The maximum tunability of the magnetoelectric effect based on the DC bias magnetic field is more than 10%. The induced AC voltage of effective values increases almost lineally with increasing AC signal magnetic field. The detected magnetoelectric effect of the system exhibits hysteresis, and the magnetoelectric hysteresis loops are almost unchanged with the test period. These findings provide a type of capacitor for potential applications in magnetic detections and magnetoelectric sensors.

A study has been conducted to develop proper test methods and to utilize the tests to evaluate three-dimensional mechanical behavior of a polyvinyl chloride structural foam (Divinycell H80 with nominal density of 80 kg/m3). Transversely isotropic foam microstructure was examined and it revealed that the cell size aspect ratio in in-plane directions was near unity but greater than one in the out-of-plane (rise) direction. Foam stiffness properties, i.e. moduli and Poisson’s ratios, were obtained in different loading modes, along both in-plane and out-of-plane directions. The influence of test specimen geometry on compressive properties was studied. Foam specimens with both straight-side and reduced gage sections were designed, fabricated and tested. The effect of specimen gage-section aspect ratio was identified as a critical geometric parameter, affecting foam compressive properties. For foam tensile properties, specimens with different cross-sectional dimensions in the gage section were used. The results revealed transversely isotropic characteristics of the foam material. To evaluate foam shear properties a scaled shear test method was developed. The results indicated a significant difference in in-plane and out-of-plane foam shear stiffness properties. [ABSTRACT FROM AUTHOR]