Goat Anti-Human Tau (Aa1-16) Polyclonal antibody

Alzheimer's disease is often considered a disease of neurons. This study reveals that astrocytes are also impaired by the disease and that these cells contribute more to memory deterioration than previously thought. Alzheimer's disease (AD) is characterized by the accumulation of the tau protein in neurons, neurodegeneration and memory loss. However, the role of non-neuronal cells in this chain of events remains unclear. In the present study, we found accumulation of tau in hilar astrocytes of the dentate gyrus of individuals with AD. In mice, the overexpression of 3R tau specifically in hilar astrocytes of the dentate gyrus altered mitochondrial dynamics and function. In turn, these changes led to a reduction of adult neurogenesis, parvalbumin-expressing neurons, inhibitory synapses and hilar gamma oscillations, which were accompanied by impaired spatial memory performances. Together, these results indicate that the loss of tau homeostasis in hilar astrocytes of the dentate gyrus is sufficient to induce AD-like symptoms, through the impairment of the neuronal network. These results are important for our understanding of disease mechanisms and underline the crucial role of astrocytes in hippocampal function.

The critical resolved shear stress (CRSS) and its related plastic deformation of titanium with hexagonal close packed structure are highly anisotropic, leading to low ductility of the material. Understanding the alloying effect on the CRSS is crucial for the improvement of the mechanical properties through rational composition design. Accurate prediction of the CRSS is not straightforward due to the atomic randomness of the alloy. The generalized stacking fault energies (GSFEs) for the basal and prismatic plane < a > slips of random alpha-Ti1-xAlx alloys (0 <= x <= 0.1875) are calculated by using first-principles methods including exact muffin-tin orbitals (EMTO) and plane-wave psuedopotential (VASP) methods in this work. The random distribution of Al in the alloy is treated by using both coherent potential approximation (CPA) for EMTO and special quasirandom structure (SQS) techniques for VASP. The CRSSs are then evaluated within the frame work of semi-discrete variational Peierls-Nabarro model. The VASP-SQS calculations with atomic relaxation generate reasonably good GSFE and CRSS compared with the EMTO-CPA and VASP-SQS calculations without atomic relaxation. For pure Ti, the unstable stacking fault energy (gamma(usf)) and CRSS (tau(a)) for the basal < a > slip are higher than those for the prismatic < a > slip. With increasing Al concentration x, gamma(b)(usf) for the basal < a > slip decreases whereas gamma(p)(usf) for the prismatic < a > increases. The CRSSs for the basal < a > slip (tau(b)(a)) and the prismatic < a > slip (tau(p)(a)) both increase with x while tau(p)(a) increases faster than tau(b)(a) such that tau(b)(a) approaches to tau(p)(a). The calculated CRSSs explain successfully our recently measured mechanical properties (yield strength, fracture toughness, ultimate strength, and elongation) of the alpha-Ti1-xAlx alloy against x. (C) 2020 Elsevier B.V. All rights reserved.