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Proper evaluation of the wheel-rail contact is necessary to understand the dynamics of railway vehicles and the causes of wear and damage to components such as wheels and rails. Numerical methods are often used to evaluate the dynamic contact condition between the wheel and rail; however, there are few promising methods for experimental evaluation. It is important to develop a measurement method because the wheel-rail contact is easily changed owing to vehicle-track dynamic interactions. In this study, we used a film-based pressure sensor equipped with force-sensitive resistors to measure the contact area between the wheel and rail during vehicle operation. Using the film-based pressure sensor, we evaluated the geometry of the contact area and position. The validity of the measured contact position is evaluated by comparing it with the contact position based on the cross-sectional profiles of the wheel and rail and the wheelset displacement during a vehicle running. [ABSTRACT FROM AUTHOR]

Methylmercury is a ubiquitous neurotoxic substance present in the environment, and health concerns, especially through the consumption of seafood, remain. Glutathione (GSH)-mediated detoxification and the excretion of methylmercury are known metabolic detoxification pathways. We have also discovered a mechanism by which endogenous super-sulfides convert methylmercury to nontoxic metabolites such as bis-methylmercury sulfide. However, these metabolites are present in very small quantities, and the significance of the detoxification of methylmercury by super-sulfides is not well understood. Methylmercury binds to thiol groups in vivo but can also react with highly reactive selenols (selenocysteine residues). Such covalent bonds (S-mercuration and Se-mercuration) are broken by nucleophilic substitution reactions with other thiol and selenols, however, the contribution of super-sulfides to this substitution reaction is not well understood. Interestingly, a recent study suggested that selenoprotein P, the major selenium transport protein in plasma, binds to methylmercury, however, Se-mercuration was not determined. In this review, we introduce these series of reactions and discuss their involvement with super-sulfides in methylmercury toxicity.