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One of the hallmarks of Alzheimer's disease is abnormal deposition of tau proteins in the brain. Although plasma tau has been proposed as a potential biomarker for Alzheimer's disease, a direct link to brain deposition of tau is limited. Here, we estimated the amount of in vivo tau deposition in the brain by PET imaging and measured plasma levels of total tau (t-tau), phosphorylated tau (p-tau, T181) and amyloid-β1-42. We found significant correlations of plasma p-tau, t-tau, p-tau/amyloid-β1-42, and t-tau/amyloid-β1-42 with brain tau deposition in cross-sectional and longitudinal manners. In particular, t-tau/amyloid-β1-42 in plasma was highly predictive of brain tau deposition, exhibiting 80% sensitivity and 91% specificity. Interestingly, the brain regions where plasma t-tau/amyloid-β1-42 correlated with brain tau were similar to the typical deposition sites of neurofibrillary tangles in Alzheimer's disease. Furthermore, the longitudinal changes in cerebral amyloid deposition, brain glucose metabolism, and hippocampal volume change were also highly associated with plasma t-tau/amyloid-β1-42. These results indicate that combination of plasma tau and amyloid-β1-42 levels might be potential biomarkers for predicting brain tau pathology and neurodegeneration. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is the most prevalent type of dementia. Reports have revealed that the peripheral immune system is linked to neuropathology; however, little is known about the contribution of B lymphocytes in AD. For this longitudinal study, 133 participants are included at baseline and second-year follow-up. Also, we analyze B cell receptor (BCR) repertoire data generated from a public dataset of three normal and 10 AD samples and perform BCR repertoire profiling and pairwise sharing analysis. As a result, longitudinal increase in B lymphocytes is associated with increased cerebral amyloid deposition and hyperactivates induced pluripotent stem cell-derived microglia with loss-of-function for beta-amyloid clearance. Patients with AD share similar class-switched BCR sequences with identical isotypes, despite the high somatic hypermutation rate. Thus, BCR repertoire profiling can lead to the development of individualized immune-based therapeutics and treatment. We provide evidence of both quantitative and qualitative changes in B lymphocytes during AD pathogenesis. [Display omitted] • Longitudinal increase in B cells is associated with cerebral amyloid deposition • B cell receptor repertoire profiling and pairwise sharing analysis are conducted • Patients with Alzheimer's disease share similar class-switched BCR sequences • B cell-derived immunoglobulin G induces microglial dysfunction in the brain Park et al. perform longitudinal analyses, B cell receptor repertoire profiling, and imaging analyses to identify the contribution of B lymphocytes to Alzheimer's disease pathology. They identify longitudinal increase in B lymphocyte populations, ensuing hyperactivation of microglia, and commonalities of BCR repertoires in Alzheimer's disease. [ABSTRACT FROM AUTHOR]

The electrical stability of molybdenum disulfide (MoS2) transistors is crucial for their use in various applications. However, it is tricky to evaluate the inherent stability of MoS2 transistors because it is highly dependent on environmental conditions during measurement such as humidity, light, and electrical factors. We studied the threshold voltage instability under negative bias stress at a variety of temperatures in a vacuum and in the dark to eliminate any environmental effects. In particular, the measurement of transfer curves under stress is minimized in order to study the inherent instability of MoS2 transistors, even though the measurement of transfer curves is normally indispensable to check for the evolution of electrical instability. MoS2 transistors have high average effective energy when compared to conventional amorphous Si and oxide semiconductor transistors, which allows for adequate operation at high temperatures. (© 2014 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

The application of ion gels as gate dielectrics having an excellent mechanical flexibility and high capacitance to molybdenum disulfide (MoS2) devices has been extensively studied; however, some issues remain unaddressed with regard to device stability such as gate leakage current, hysteresis, and bias stress instability. This study suggests a fabrication process for the ionic gating of the MoS2 device to enhance the device stability by laminating the ion gel film onto the MoS2 transistor using a cut‐and‐stick method and adding a passivation layer to remove unintentional parasitic capacitances generated by the capacitive coupling effect. The ionic gating MoS2 transistor fabricated via this process operates at a low voltage (<1 V) and exhibits superior electrical characteristics such as low gate leakage currents (≈10−11 A), high on–off ratio (>106), and low hysteresis (<0.05 V). To further investigate the device stability, bias stress instability of the ionic gating MoS2 transistor is examined. The charge‐trapping mechanism is the main cause of threshold voltage shifts under gate bias stress. [ABSTRACT FROM AUTHOR]

In article number 1800284, Jang‐Yeon Kwon and co‐workers demonstrate highly sensitive tactile sensors using a pyramid‐plug structure that enables them to detect pressure, shear force, and torsion. The wide operating range of the sensor, from soft breathing to arbitrary multiplex touching, makes it particularly promising for future applications. [ABSTRACT FROM AUTHOR]

Sensors that detect and discriminate external mechanical forces are a principal component in the development of electronic tactile systems that can mimic the multifunctional properties of human skin. This study demonstrates a pyramid‐plug structure for highly sensitive tactile sensors that enables them to detect pressure, shear force, and torsion. The device is composed of pyramid‐patterned ionic gel inspired by neural mechanoreceptors and engraved electrodes. Based on a pyramid‐plug structure, the deformation mechanism differs between different types of external mechanical loadings. The sensor provides the high sensitivities of 1.93 kPa−1, 29.88 N−1, and 3.39 (N cm)−1, and a wide range of detection for tactile daily activity. Moreover, this tactile sensor could work through either of the two transduction methods (capacitive transduction and piezoresistive transduction). It is shown that this tactile sensor can be used to monitor changes in electrical signals ranging from those caused by human breathing to those caused by arbitrary multiplex human touching. A pyramid‐plug structure for highly sensitive tactile sensors that enables them to detect pressure, shear force, and torsion is demonstrated. This tactile sensor could work by each of the two transduction methods. The sensor provides the high sensitivities of 1.93 kPa−1, 29.88 N−1, and 3.39 (N cm)−1, and a wide range of detection for tactile daily activity. [ABSTRACT FROM AUTHOR]