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Compromised mitochondrial electron transport chain (ETC) activities are associated with depression in humans and rodents. However, the effects of the enhancement of mitochondrial ETC activities on depression remain elusive. We recently reported that an extremely low-frequency electromagnetic field (ELF-EMF) of as low as 10 μT induced hormetic activation of mitochondrial ETC complexes in human/mouse cultured cells and mouse livers. Chronic social defeat stress (CSDS) for 10 consecutive days caused behavioral defects mimicking depression in mice, and using an ELF-EMF for two to six weeks ameliorated them. CSDS variably decreased the mitochondrial ETC proteins in the prefrontal cortex (PFC) in 10 days, which were increased by an ELF-EMF in six weeks. CSDS had no effect on the mitochondrial oxygen consumption rate in the PFC in 10 days, but using an ELF-EMF for six weeks enhanced it. CSDS inactivated SOD2 by enhancing its acetylation and increased lipid peroxidation in the PFC. In contrast, the ELF-EMF activated the Sirt3-FoxO3a-SOD2 pathway and suppressed lipid peroxidation. Furthermore, CSDS increased markers for mitophagy, which was suppressed by the ELF-EMF in six weeks. The ELF-EMF exerted beneficial hormetic effects on mitochondrial energy production, mitochondrial antioxidation, and mitochondrial dynamics in a mouse model of depression. We envisage that an ELF-EMF is a promising therapeutic option for depression. [ABSTRACT FROM AUTHOR]

Assessing the residual performance of timber joints affected by decay is important for seismic diagnosis and reinforcement of timber structures. This study introduces a method to evaluate the embedment stiffness of metal washers in bolted timber joints using a torque wrench. Formulas for the embedment stiffness of metal washers using the torque gradient (the gradient of the tightening torque against the tightening rotation angle of the nut) and the nut factor are presented and the calculated values are compared with experimental values obtained by conducting tightening tests with a torque wrench and embedment tests of metal washers in bolted joints made from Japanese cedar, Hiba, and Japanese cypress. The results show that the experimental values of the embedment stiffness of metal washers in Japanese cedar and Hiba are generally within the range of the values calculated from the minimum and maximum values of the nut factor. However, for Japanese cypress, the values calculated from the maximum value of the nut factor exceed the experimental values. This was presumably due to locally large frictional forces generated on the bearing surface or threaded part. [ABSTRACT FROM AUTHOR]

In previous studies on optimized single-layer latticed domes, the inner space and external shape of the optimized dome is different from those of the initial dome. This difference may result in loss of structural functionality and aesthetics intended by the designers, making it difficult to separately evaluate the mechanical properties of the grid patterns and shape of the surface. In this study, 64 types of single-layer latticed domes having different geometric properties are optimized to obtain mechanically effective grid patterns. Six types of objective functions are employed. The nodal coordinates of the domes serve as the design variables under geometrical constraints, where the nodes of the domes can be shifted on the surface area. The geometric and mechanical properties of the optimized grid patterns are evaluated quantitatively against the objective functions. Moreover, interactions between the geometric and mechanical properties are investigated. The results show that the optimized grid pattern has superior mechanical properties and geometric imperfection sensitivity. This optimization scheme can be applied for designing mechanically effective grid patterns for single-layer latticed domes. [ABSTRACT FROM AUTHOR]