Nasal Rifampicin Improves Cognition in a Mouse Model of Dementia with Lewy Bodies by Reducing α-Synuclein Oligomers

α-Synuclein oligomers are thought to play an important role in the pathogenesis of dementia with Lewy bodies (DLB). There is no effective cure for DLB at present. Previously, we demonstrated that in APP- and tau-transgenic mice, oral or intranasal rifampicin reduced brain Aβ and tau oligomers and improved mouse cognition. In the present study, we expanded our research to DLB. Rifampicin was intranasally administered to 6-month-old A53T-mutant α-synuclein-transgenic mice at 0.1 mg/day for 1 month. The mice displayed memory impairment but no motor deficit at this age, indicating a suitable model of DLB. α-Synuclein pathologies were examined by the immunohistochemical/biochemical analyses of brain tissues. Cognitive function was evaluated by the Morris water maze test. Intranasal rifampicin significantly reduced the levels of [pSer129] α-synuclein in the hippocampus and α-synuclein oligomers in the visual cortex and hippocampus. The level of the presynaptic marker synaptophysin in the hippocampus was recovered to the level in non-transgenic littermates. In the Morris water maze, a significant improvement in spatial reference memory was observed in rifampicin-treated mice. Taken together with our previous findings, these results suggest that intranasal rifampicin is a promising remedy for the prevention of neurodegenerative dementia, including Alzheimer’s disease, frontotemporal dementia, and DLB.     

MicroRNA (miRNA) cloning analysis reveals sex differences in miRNA expression profiles between adult mouse testis and ovary

MicroRNAs (miRNAs) are endogenous non-coding small RNAs that can regulate the expression of complementary mRNA targets. Identifying tissue-specific miRNAs is the first step toward understanding the biological functions of miRNAs, which include the regulation of tissue differentiation and the maintenance of tissue identity. In this study, we performed small RNA library sequencing in adult mouse testis and ovary to reveal their characteristic organ- and gender-specific profiles and to elucidate the characteristics of the miRNAs expressed in the reproductive system. We obtained 10,852 and 11 744 small RNA clones from mouse testis and ovary respectively (greater than 10,000 clones per organ), which included 6630 (159 genes) and 10,192 (154 genes) known miRNAs. A high level of efficiency of miRNA library sequencing was achieved: 61% (6630 miRNA clones/10,852 small RNA clones) and 87% (10,192/11,744) for adult mouse testis and ovary respectively. We obtained characteristic miRNA signatures in testis and ovary; 55 miRNAs were detected highly, exclusively, or predominantly in adult mouse testis and ovary, and discovered two novel miRNAs. Male-biased expression of miRNAs occurred on the X-chromosome. Our data provide important information on sex differences in miRNA expression that should facilitate studies of the reproductive organ-specific roles of miRNAs.     

In situ transmission electron microscopy observation of the decomposition of MgH2 nanofiber

In this paper, we presented an investigation of the phase transformation of MgH₂ to Mg, in which a sample of a single-crystal MgH₂ nanofiber was prepared by hydriding chemical vapor deposition (HCVD) and observed by in situ (high-resolution) transmission electron microscopy (TEM). The results indicated that the orientation relationship between MgH₂ and Mg during the phase change was: one of the zone axis of MgH₂ <110> parallel to Mg [0001] zone axis, or one of the plane {110} of MgH₂ parallel to the basal plane of Mg (0001). On the basis of the obtained results, we proposed a structural model for the phase change of MgH₂ to Mg.     

An Extension of the COCR Method to Solving Shifted Linear Systems with Complex Symmetric Matrices

The Conjugate Orthogonal Conjugate Residual (COCR) method [T. Sogabe and S.-L. Zhang, JCAM, 199 (2007), pp. 297-303.] has recently been proposed for solving complex symmetric linear systems. In the present paper, we develop a variant of the COCR method that allows the efficient solution of complex symmetric shifted linear systems. Some numerical examples arising from large-scale electronic structure calculations are presented to illustrate the performance of the variant.     

Immobilization of aromatic aldehyde molecules on indium tin oxide surface using acetalization reaction

We demonstrated an acetalization reaction as a versatile method to immobilize aromatic aldehyde molecules on surfaces of metal oxides, silicon dioxide, and indium tin oxide. First, a trimethylsily (TMS) terminated surface was formed using a silylation reaction between a chloride group of trimethylsilychloride and a hydroxyl group of the substrate surfaces. Second, terephthalaldehyde (TPA) was immobilized on the surfaces using an acetalization reaction between the TMS-terminated surface and an aldehyde group of TPA. Results of contact angle, X-ray photoelectron, and ultraviolet absorption spectra revealed that the TPA molecules on the surfaces were well-packed with a high surface density.     

Damage characterization in thin-ply composite laminates under out-of-plane transverse loadings

Composite laminates with thin-ply layers are expected to exhibit superior damage resistance to the standard composite laminates. This study investigated the damage characteristics of carbon fiber/toughened epoxy thin-ply laminates subjected to transverse loadings. Quasi-isotropic laminates were prepared using both standard prepregs and thin-ply prepregs in order to examine the effect of ply thickness on the damage accumulation processes. Clear difference on damage accumulation process between standard laminates and thin-ply laminates was identified; fiber fractures were susceptible to formation in thin-ply laminates. Finally, the reason of the difference on damage process was investigated using finite element analyses, and it was clarified that the accumulated delamination position has a significant effect on the fiber fractures during the indentation.     

Energy release rates of bi-material interface crack including residual thermal stresses: Application of crack tip element method

Crack tip element method is applied to the formulation of the energy release rate associated with interfacial crack growth of laminates with residual thermal stresses using the Timochenko beam model. Special attention is paid to the energy release rates of double cantilever beam and mixed-mode bending tests of bi-material specimens, and mode-I and mode-II energy release rates are formulated including residual thermal stresses. The derived results are verified by the comparison to finite element analysis, and the effect of residual thermal stresses on the mode mixity of the double cantilever beam and mixed-mode bending tests is discussed.     

Comparison of low-melting lead-free solders in tensile properties with Sn–Pb eutectic solder

The tensile properties of Sn–8 mass % Zn–3 mass % Bi and Sn–58 mass % Bi low-melting lead-free solders were investigated and compared with those of a Sn–Pb eutectic solder. The tensile strength decreases with decreasing strain rate and increasing temperature. The tensile strength of each solder is approximately double that of the Sn–Pb solder at room temperature (RT). The ductility of each solder is inferior to that of the Sn–Pb solder. From the results of strain-rate-change tests, the stress exponents and the activation energies for creep of Sn–58Bi and Sn–8Zn–3Bi were also examined.