津田 哲哉

Abstract Objectives Intrapulpal calcifications can occur in the dental pulp of patients with diabetes. We focused on the association between ectopic calcifications in the dental pulp and advanced glycation end products (AGEs) in Spontaneously Diabetic Torii (SDT)‐fatty rats, an obese type 2 diabetic rat model, to determine the mechanism of calcification with pulp stone in the dental pulp. Materials and Methods Pathologic calcification in the dental pulp of SDT‐fatty rats was observed using electron microscopy and immunohistochemical analysis. Moreover, mechanical analysis of periapical region of molar tooth against occlusal force was performed. Results In SDT‐fatty rats, pathogenic pulpal calcifications occurred during blood glucose elevation after 6 weeks, and granular calcification was observed in the dental pulp after 11 weeks. Pentosidine, a major AGE, and the receptor for AGEs were strongly expressed in the dental pulp of SDT‐fatty rats. S100A8, TNF‐α, and IL‐6 also showed positive response in the dental pulp of the SDT‐fatty rat, which indicated pulpal inflammation. Blood flow disorder and hypoxic dental pulp cells were also observed. In silico simulation, strain from occlusal force concentrates on the root apex. Conclusions Glycation makes blood vessels fragile, and occlusal forces damage the vessels mechanically. These are factors for intrapulpal calcification of diabetes.

The impact of sp² carbon material species on the ORR performance of electrocatalysts prepared through the one-pot pyrolysis method with an ionic liquid was revealed by the combination of several commonly used analytical approaches.

<p>An appropriate combination of Si anodes and binary bis(fluorosulfonyl)amide-based ionic liquid electrolytes significantly improves Li-ion battery performances.</p>

© 2019 Scanning electron microscopy (SEM) for the electrode reaction in next-generation battery with ionic liquid (IL) electrolyte, which has both high stability under vacuum and an antistatic nature, is applied to the binder-free high capacity Si anode to observe the morphology change of the Si nanoparticle aggregate active material at different potentials during charge-discharge processes. In the IL electrolyte, 1-ethyl-3-methylimidazolium bis(fluoromethylsulfonyl)amide ([C2mim][FSA]) with 1.0 M lithium bis(trifluoromethanesulfonyl)amide (Li[TFSA]), the morphology greatly varied at the plateau observed at 0.200 to 0.070 V (vs. Li(I)/Li) in the charge-discharge curve during the first cycle, suggesting that phase transition of a-Si to c-Li13Si4 is a potential problematic process. After the first cycle, the lithiation process initiated at more positive potential. Similar behavior was also recognized in the Li[TFSA]‒tetraglyme solvate IL electrolyte in a 1:1 molar ratio ([Li(G4)][TFSA]).

© 2019 American Chemical Society. Pt and PtNi alloy nanoparticle-supported multiwalled carbon nanotubes (Pt/MWCNTs and PtNi/MWCNTs) are prepared by a one-pot pyrolysis method with the N,N,N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)amide ionic liquid (IL) containing platinum and nickel precursors, Pt(acac)2, Ni[Tf2N]2, and Ni(acac)2, with suspended MWCNTs. The composite materials can be prepared by simply heating the IL solution at 573 K. The resulting materials show favorable catalytic activity toward the oxygen reduction reaction and durability superior to those of typical commercially available electrocatalysts. The catalytic activity of the PtNi/MWCNTs depends on the Ni content of the PtNi alloy nanoparticles. One of the PtNi/MWCNTs shows 1.4 times higher mass activity than a typical commercial electrocatalyst. A plot of the mass activity as a function of the Ni content gives a mountain-shaped curve with a vertex at ca. 25 atomic percent Ni. This one-pot process can readily control the catalytic properties of the PtNi/MWCNTs by changing the molar fraction of Pt and Ni precursors.

© 2019 by the authors. New types of ionic liquids (ILs) with an epoxy group on a piperidinium-type cation were successfully synthesized by the simple anion exchange reaction of a solid 1-allyl-1-(oxiran-2-ylmethyl)piperidinium bromide, which was designed in this study. Unfortunately, the physicochemical properties, e.g., viscosity and ionic conductivity, of the ILs were inferior to those of common ILs such as 1-ethyl-3-methylimidazolium tetrafluoroborate ([C2mim][BF4]) and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C4mim][Tf2N]). However, the resulting ILs are of great interest as reaction intermediates: For example, the epoxy group on the cation could react with various reagents, including CO2. Consequently, the modification of the cation structure in the ILs was possible. This is particularly interesting because it is very difficult to modify commonly used ILs. The approach established in this article will provide a favorable synthetic route for creating novel functional ILs in the future.

© The Author(s) 2018. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. X-ray micro-CT is one of the most useful techniques to examine 3D cellular architecture inside dry seeds. However, the examination of imbibed seeds is difficult because immersion in water causes a decline in the image quality. Here, we examined the use of ionic liquids for specimen preparation of chemically fixed imbibed seeds of Arabidopsis. We found that treatment with high concentrations of ionic liquids after osmium tetroxide fixation helped not only to prevent the structural damage caused by seed shrinkage, but also to preserve the image quality. Under these conditions, the cellular architecture of seeds was also well maintained.

© 2019 The Chemical Society of Japan. Polyacrylonitrile (PAN)-derived carbon beads with uniform size and high surface area were successfully prepared by the carbonization of PAN and activation by KOH. Physicochemical analysis revealed that the PAN-derived carbon beads activated by KOH possessed larger pore volume and pore width than the same types of carbon beads activated by CO2 and commercially available activated carbon powder. Even if the PAN-derived carbon beads were made into an electrode without any conducting supplements, the electrode possessed a higher specific capacitance than an electrode composed of commercially available activated carbon in the presence of conducting acetylene black powders. Origins of such desirable properties as carbon materials used for electric double layer capacitors were investigated by AC impedance measurements in both aqueous and non-aqueous electrolyte solutions.

© The Electrochemical Society of Japan, All rights reserved. Two sizes of polyacrylonitrile beads were prepared as precursors of carbon beads by varying the reaction solvent ratio of N,N-dimethylformamide to methanol for dispersion polymerization reaction. The spherical structure of the carbon beads were maintained after carbonization and activation. Charge-discharge tests and AC-impedance analyses revealed that the electric resistance between the particles is low without conducting supplements. In addition, an appropriate pore size brought by the KOH activation of smaller carbon beads lead to a better capacitor performance at high current conditions.

Based on electron microscope techniques developed for ionic liquids (ILs), which have both high stability under vacuum and an antistatic nature, specially-designed Li battery cells with all components contained in actual Li batteries were fabricated for in situ electron microscope observation. Various interesting anode behaviors in the Li battery were observed. For example, Si thin flake active material can store Li(I) electrochemically, causing the morphology to change into a ribbon-like or isotropic expanded structure. Surprisingly any damage to the Si material was not recognized by nanoscale imaging because of the thin layer structure that can release internal stress spontaneously during lithiation. In addition, the Li metal deposition process was directly observed and a similar approach can be applied to in situ X-ray photoelectron spectroscopic analysis.

The physicochemical properties and electrochemical behavior of 1-butyl-3-methylimidazolium aryltrifluoroborate ([C4mim][ArBF3]) with various substituents, e.g., methoxy, fluoro, trifluoromethyl, and cyano groups, introduced on the phenyl moiety on the anion are examined. Several position isomers of the [ArBF3]- anion are also prepared to provide further insight into the effect of the position. The equivalent conductivity and the electrochemical stability for some [C4mim][ArBF3] room-temperature ionic liquids (RTILs) is qualitatively discussed from the results of quantum chemical calculations of the cation-anion interaction and the HOMO energy level of the anion. Interestingly, [C4mim][ArBF3] RTILs with an electron-withdrawing group on the phenyl moiety electrochemically form an ion-selective membrane on a Pt electrode, and only neutral and cationic species can pass through the membrane.

Pt-nanoparticle-supported carbon catalysts for the electrochemical oxygen reduction reaction produced using a Pt-nanoparticle-monodispersed ionic liquid (IL) show better durability than a commercially available catalyst due to the small amount of IL between the Pt nanoparticles and the carbon support. In this study, to add further functionality to the catalysts prepared with the Pt-nanoparticle-monodispersed IL, a protic organic salt, diphenylammonium hydrogen sulfate ([DPA][HSO4]), and a protic ionic liquid, N,N-diethyl-N-methylammonium hydrogen sulfate ([DEMA][HSO4]), are employed for catalyst preparation. Interestingly, the mass activity and durability of the resulting catalyst are significantly enhanced by the addition of an electrochemically polymerizable [DPA][HSO4] to the Pt-nanoparticle-monodispersed [DEMA][HSO4] because of the formation of a conducting polymer, poly(diphenylamine), between the Pt nanoparticles and the carbon support during potential cycling.

Because ionic liquids (ILs) have numerous various interesting features, they are recognized as important functional reaction media and liquid materials. Several applications that take advantage of each feature have been proposed. The combination of a set of unique features, which includes negligible vapor pressure, good chemical/electrochemical stability, as well as antistatic properties, has led to the creation of some novel analytical techniques wherein the IL is used with analysis equipment that requires vacuum conditions, e.g., SEM, TEM, and XPS. In recent times, vacuum analytical techniques that employ ILs have had a significant impact on a wide variety of science and technology applications. In this chapter, recent ionic liquid-electron microscopy techniques, including associated electron-beam irradiation techniques such as energy dispersive X-ray spectrometry, electron diffraction, and ionic liquid-X-ray photoelectron spectroscopy are introduced. The former is often employed for in situ observation of electrochemical reactions in next-generation battery systems and for monitoring nanoparticle production/growth processes in ILs, and the latter can reveal IL structure at the vacuum-IL phase boundary as well as chemical/electrochemical reactions in ILs on a molecular scale.

© North Carolina State University. A functional ionic liquid 1-butyl-3-vinylimidazolium iodide ([BuVyIm]I) was synthesized, and it exhibited the features of both decay resistance and leaching resistance after in-situ polymerization within wood. Treated wood specimens of Cryptomeria japonica were evaluated in this preliminary study using leaching tests with distilled water and decay tests for 12 weeks with brown rot fungi Fomitopsis palustris. The [BuVyIm]I polymerized by 100 kGy 60Co gamma irradiation was retained in wood after 10 wash and dry cycles, whereas nearly all of the [BuVyIm]I was washed out in the cases of 10 kGy and no irradiation. The decay testing of these specimens showed that sapwood had a different decay resistance depending on the strength of gamma irradiation used, whereas the treated heartwood did not support fungal growth. The results of this study imply that [BuVyIm]I polymerized by 100 kGy gamma irradiation have potential for wood preservation.

© 2018 The Electrochemical Society of Japan, All rights reserved. In order to clarify the nanoparticles formation process of the metal sputtering onto ionic liquid, which is the facile method to prepare metal nanoparticles, the vacuum-liquid interface was captured by a camcorder while conducting gold sputtering. Because of intense color of Au clusters, move of Au clusters by convection of ionic liquid was clearly observed. The convection is a dominant factor in a transport of the resulting Au nanoparticles from the surface to interior of the ionic liquid.

Low-cost graphene nanoplatelet-polysulfone composite cathodes for a rechargeable aluminum battery with a Lewis acidic AlCl3-1-ethyl-3-methylimidazolioum chloride ([C2mim]Cl) ionic liquid are prepared by a standard slurrycoating method for the composite electrode, and conductive additives such as acetylene black (AB), ketjen black (KB), and vapor grown carbon fiber (VGCF) are explored in order to improve the cathode performance. All the cathodes show reversible electrode reactions related to the intercalation reaction of [AlCl4]- into the graphene nanoplatelets. The cathodes achieve a discharge capacity of ca. 70-80mAhg-1 at 1000mAg-1. However, the rate capability and the capacity retention rate strongly depend on the conductive additive species. The best cathode performance is obtained when the additive is an equal mixture of VGCF and KB. The specific capacity is ca. 55mAhg-1 at 10000mAg-1. The retention rate based on the capacity observed at 1000mAg-1 exceeds 65%. A Ragone plot constructed from the data shown in this article suggests that an Al rechargeable battery with a VGCFKB added graphene nanoplatelet-polysulfone composite cathode has great potential as a future high-power density rechargeable battery.

Rechargeable aluminum batteries composed of an aluminum anode, an expanded graphite cathode, and an inorganic chloroaluminate ionic liquid electrolyte show remarkably improved capacity, reversibility, and rate capability at 393 K compared to cells based on a common organic salt based ionic liquid, AlCl3-1-ethyl-3-methylimidazolium chloride.

Novel room temperature ionic liquids (RTILs) were synthesized using phenyltrifluoroborate ([PhBF3](-)), which is the simplest aryltrifluoroborate structure. The [PhBF3](-)-based RTIL5 showed desirable transport properties, i.e., viscosity and ionic conductivity, and the anion has a rigid and bulky aromatic ring. The properties of 1-butyl-3-methylimidazolium phenyltrifluoroborate ([C(4)mim][PhBF3]) are comparable to those of 1-butyl-3-methylimidazolium tetrafluoroborate [C(4)mim][BF4]). The molecular volume of the RTIL5, which was estimated using the appropriate quantum chemical calculations, highly correlated with the transport properties. The cation volume is an important factor that can control the physicochemical properties in this RTIL system. In addition, the basic skeleton structure of the cation determined the electrochemical window. (C) 2017 Elsevier B.V. All rights reserved.

Understanding the electrochemical behavior and controlling the morphological variations of electrodes are critical for the design of high-capacity batteries. In this article, we describe a newly established operando scanning electron microscopy (SEM) to visualize the battery reactions in a modified coin cell, which allowed the simultaneous collection of electrochemical data and time-resolved images. The investigated silicon (Si)-polyimide-binder electrode exhibited a high capacity (similar to 1500 mAh g(-1)) and a desirable cyclability. Operando SEM revealed that the morphology of the Si anode drastically changed and cracks formed on the electrode because of the lithiation-induced volume exprision of the Si particles during the first charge process. Interestingly, the thickness variation in the Si composite layer was moderated in subsequent cycles. This strongly suggested that cracking caused by the breakage of the stiff binder alleviated the internal stress experienced by Si. On the basis of this finding by the operando SEM technique, patterned Si electrodes with controlled spacing were successfully fabricated, and their improved performance was confirmed.

Due to the extremely low vapor pressure of ionic liquids (ILs), electrochemical deposition/dissolution of hexagonal hollow CuSn alloy tubes in IL can be real-time observed with a scanning electron microscope (SEM). Two specially made electrochemical cells are used for the top-view and side-view observations. A series of clear SEM images reveals the hexagonal cones are formed prior to further developing hexagonal tubes. At the beginning, many small nuclei are formed on the electrode surface. Due to the electrodeposition rate being slow enough for the nuclei to crystallize into hexagonal structures, the electrodeposition rate is faster on the periphery than the inside of the structures. As the electrodeposition progresses, the tube wall will grow thicker; and a secondary tube emerges inside the primary tube. Finally, shell-by-shell hexagonal tubes are formed. Furthermore, the In situ SEM observation also reveals that the dissolution of tube. starts from its inner wall followed by a sudden collapse of its wall. In this paper, we establish a simple and convenient method, which can be broadly applied to study of metal, alloy, and semiconductor growth in real time.

Functional carbon materials have recently attracted attention as positive electrode active materials for Al rechargeable batteries in conjunction with an Al negative electrode and a chloroaluminate ionic liquid electrolyte. This study explores a new carbon material, a graphene-decorated activated carbon fiber cloth (ACFC), for the positive electrode. Graphene-decorated ACFCs can be used in a binder-free manner and will directly contribute to increased gravimetric capacity of the whole electrode [mAh (g(electrode))(-1), not per the active material]. Specifically, the positive electrode behaviors of three types of ACFC-based electrodes are examined in a Lewis acidic AlCl3-1-ethyl-3-methylimidazolioum chloride ([C(2)mim] Cl) room-temperature ionic liquid. Uncoated and low-loading graphene-coated ACFC electrodes show an electric double layer capacitor (EDLC)-like behavior, whereas the intercalation/deintercalation reaction of chloroaluminate anion (e.g., [AlCl4](-)) is observed for the high-loading graphene-coated one. These electrodes exhibit a good cyclability and satisfactory coulombic efficiency up to 800 cycles at a current density of 500 mA g(-1). (C) The Author(s) 2017. Published by ECS. All rights reserved.

In this article, we review the progress in the area of electrochemical technology with Lewis acidic haloaluminate room-temperature ionic liquids (RTILs), such as AlCl3-1-ethyl-3-methylimidazolium chloride and AlBr3-1-ethyl-3-methylimidazolium bromide, and novel chloroaluminate mixtures consisting of AlCl3 and polarizable molecules, e.g., dimethylsulfone and urea, during this decade. The number of researchers in the field seems to increase steadily, because now we can handle haloaluminate RTILs and their mixtures with other solvents and materials more easily than we could in the past. In this review, we have categorized the electrochemical technology based on these RTILs into two topics: electroplating and energy storage. In fact, much of the current research is based on work begun during the period from similar to 1970 until the 1990's. But new findings and insights have been obtained through the application of state-of-the-art technologies. With this new information, haloaluminate RTILs and solvent mixtures have the spotlight again. (C) The Author(s) 2017. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.

Boron and nitrogen co-doped ordered microporous carbons with high surface areas are obtained by using NaY zeolite as a hard template and an ionic liquid, 1-ethyl-3-methylimidazolium tetracyanoborate (EMIT), as a BN source. An acetylene-gas supply during a pyrolysis is effective to avoid the unfavourable reaction of zeolite and EMIT.