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Tonooka K.,Kanagawa University | Naruki N.,Kanagawa University | Honma K.,Kanagawa University | Agei K.,Kanagawa University | And 6 more authors.
Forensic Science International | Year: 2016

A high-performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) with electrospray ionization (ESI) procedure for the simultaneous determination of nine local anesthetic drugs (procaine, mepivacaine, lidocaine, ropivacaine, oxybuprocaine, tetracaine, bupivacaine, T-caine and dibucaine) in human serum is described. The chromatographic separation was performed on a Mightysil-RP-18 GP II column (2.0 mm × 150 mm, particle size 5 μm). The mobile phase consisted of 10 mM acetic ammonium buffer (pH 5.4) and acetonitrile and was delivered at a flow rate of 0.20 mL/min. The triple quadrupole mass spectrometer was operated in positive ion mode, and multiple reaction monitoring was used for drug quantification. Solid-phase extraction of the nine local anesthetic drugs added to the human serum was performed with an Oasis® HLB extraction cartridges column. The method was linear for the investigated drugs over the concentration range of 10-100 ng/mL. The recoveries of these drugs were in the range of 81.4-144%. The standard deviation (SD) values for all analytes were <0.10 for both intraday and interday accuracy and precision. The selectivity, accuracy and precision of this method are satisfactory for clinical and forensic applications. The sensitive and selective method offers the opportunity for the simultaneous screening and quantification, for clinical and forensic purposes, of almost all local anesthetics available in Japan. © 2016 Elsevier Ireland Ltd. Source

Machida M.,Japan Atomic Energy Agency | Okumura M.,Japan Atomic Energy Agency | Nakamura H.,Japan Atomic Energy Agency | Sakuramoto K.,Foundation for Promotion of Material Science and Technology of Japan
Mathematics and Computations, Supercomputing in Nuclear Applications and Monte Carlo International Conference, M and C+SNA+MC 2015 | Year: 2015

In order to clarify physicochemical behaviors of radioactive Cs released into environment from the Fukushima Daiichi nuclear power plants, we study on two issues, i.e., hydration structures of Cs+ and its adsorption on a specific edge in a clay particle (mica) by employing first principles calculations. After the fallout on the land, radioactive Cs+ inside water droplets has been mainly adsorbed on clay surfaces and transferred into a specific edge called "Frayed Edge Site", which strongly stabilizes Cs. Thus, Cs mainly migrates together with the clay particles by water flow, while a part of Cs is dissolved into water as a cation, again. Relevant to these transport processes, we find that the above two situations are important as the chemical form of Cs in environment. However, since the two forms are too small to experimentally study in details, the first-principles calculation is a powerful tool. In this paper, firstly, we report on hydration structures of Cs+ by using Born-Oppenheimer first-principles molecular dynamics. Our striking finding in the hydration structures is that Cs+ has no clear second hydration shell in contrast to any other alkali cations. Secondly, we construct a model of the Frayed Edge Site and confirm that the model actually becomes selective for Cs when expanding the interlayer distance from that of the original crystal structure through the calculation of the ion-exchange energy. Copyright © (2015) by the American Nuclear Society All rights reserved. Source

Sasuga-Araki S.,Foundation for Promotion of Material Science and Technology of Japan | Suzuki K.,Nagoya Institute of Technology | Okabayashi H.,Nagoya Institute of Technology | O'Connor C.J.,University of Auckland
Colloid and Polymer Science | Year: 2013

The microstructures of concentrated aqueous solutions of n-butyl(n-dodecyl)phosphate (BDoP) and n-hexyl(n-dodecyl)phosphate (HDoP) anions, as asymmetric double-chain surfactants, were studied using X-ray diffraction and Raman scattering techniques. The results indicated a marked difference in the aggregate behavior between BDoP and HDoP, attributed to the difference in the extent of the steric effect of the two short chains. The Raman scattering spectra provided direct evidence of the steric effect. This marked difference in the steric effect is clearly reflected in the phase structures of the BDoP and HDoP water binary systems. © 2013 Springer-Verlag Berlin Heidelberg. Source

Okayasu M.,Akita Prefectural University | Sato K.,Foundation for Promotion of Material Science and Technology of Japan | Kusaba Y.,Foundation for Promotion of Material Science and Technology of Japan
Journal of the European Ceramic Society | Year: 2011

To better understand the domain switching characteristics of lead zirconate titanate (PZT) ceramics, the orientations of domains have been directly investigated during loading and unloading using various experimental techniques. Upon loading, linear and non-linear fracture mechanics of the PZT ceramics are observed. The slope of the stress-strain response is attributed mainly to lattice strain and domain switching strain. During the loading process, electrical activity also occurs several times in the PZT ceramics. This activity is related to a lightning-like phenomenon and consists of a bright flash with a click. This electrogenerative event is caused by severe domain switching. The characteristics of domain switching and reverse switching are detected during the loading and unloading processes. The amount of domain switching depends on the grain, due to different stress levels. In addition, two patterns of 90° domain switching systems are characterized, namely (i) 90° turn about the tetragonal c-axis and (ii) 90° rotation of the tetragonal a-axis. © 2010 Elsevier Ltd. Source

Nozawa N.,Tohoku University | Saito S.,Tohoku University | Kimura T.,Tohoku University | Shibuya K.,Foundation for Promotion of Material Science and Technology of Japan | And 3 more authors.
Applied Physics Letters | Year: 2013

Co80Ir20 films with negative uniaxial magnetocrystalline anisotropy (Ku) are investigated with respect to the regularity of the stacking sequence and atomic site arrangement. Substrate heating at 600 °C enhances the negative Ku of Co 80Ir20 to -9.6 × 106 erg/cm3. X-ray diffraction analysis and scanning transmission electron microscopy of the Co80Ir20 film fabricated at 600 °C indicate (1) a near perfect hexagonal-close-packed (hcp) stacking structure and (2) an atomic layered structure that consists of randomly sequenced Ir-rich and Ir-poor layers. These hcp and composition-modulated atomic layer stacking structures are considered to be the reason for the enhancement of the negative Ku. © 2013 American Institute of Physics. Source

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