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Nanoparticles are presently considered to be high-potential additives in insulation materials. Surface modifiers can not only improve the compatibility between nanoparticles and natural ester but also enhance the insulation performance of the insulation liquid. In this work, a mixture of two natural ester insulation oils (rapeseed oil + palm fatty acid ester) doped with 3-aminopropyltriethoxysilane (KH550)-TiO2 nanoparticles was prepared, and a 56-day thermal aging experiment was implemented. Moreover, the molecular dynamics simulation was applied to investigate the improvement mechanism of the physicochemical and electrical properties from a microscopic perspective. The experimental results revealed that KH550-modified nano-TiO2 particles could reduce the generation of microwater and acidic substances during the aging process of the oil–paper insulation system, retard the degradation of the system, and improve the thermal stability and insulation performance. At the end of the thermal aging, a decrease of breakdown voltage by 7.3% and an increase of acid value by 17.3% were observed in the modified insulation oil. On the contrary, the pure insulation oil decreased the breakdown voltage by 26.96%, and the acid value increased by 28.38%. Furthermore, the molecular simulation results determined that KH550-TiO2 could combine with polar molecules through hydrogen bonds, adsorb polar molecules in insulation oil, prevent their diffusion into cellulose insulation paper, and delay the aging and decomposition of insulation paper. Therefore, the modified nanoparticles have remarkably enhanced the antithermal aging performance of the oil–paper insulation system, which provides a considerably greater application prospect for nanomodification insulation in liquid medium. [ABSTRACT FROM AUTHOR]

Mutation in human FAM134B gene has been implicated in hereditary sensory and autonomic neuropathy type IIB. We aimed to knock out Fam134b in mice and explored its phenotypes to determine whether the genetic impairments and behavioral changes can mirror manifestations noted in humans. We used CRISPR/Cas9 technology to knockout the Fam134b gene in the C57BL/6 J mouse. After confirming the knockout was successful by Sanger sequencing and Western blot, sensory function was measured using the hot plate test and the 50% paw withdrawal threshold test. In addition, standard microscopy and transmission electron microscopy were performed to observe the structural changes of the dorsal root ganglion sensory neuron and the sciatic nerve. DNA sequencing and Western blot analysis confirmed the mutation in the Fam134b mutation gene and the loss of expression of its products. Fam134b knockout mice exhibited heat pain insensitivity and mechanical hyperalgesia. Interestingly, limb damage was found in some homozygotes. Demyelination in the sciatic nerve was common. Golgi bodies were turgid in dorsal root ganglion neuron. These findings indicate that peripheral neuropathy is common in Fam134b KO mice. We believe this novel animal model is likely to have significant future potential as a reliable model for the evaluation of peripheral neuropathy and its complications. [ABSTRACT FROM AUTHOR]

In this article, we give an overview of recent research on propagation properties in high-speed railways (HSRs). The channel fading in HSRs is a big challenge for wireless access. It is essential to understand the channel-fading behavior before the system design. The novel results of propagation and channel models are presented. The details of channel characteristics, such as path loss, shadow fading, and Ricean K- factor, are discussed in each scenario. A comprehensive picture of propagation and channel-modeling research in railways is shown. [ABSTRACT FROM PUBLISHER]