[en] Intrasaccular flow disruption is a new and effective endovascular treatment for intracranial aneurysms. While endovascular treatment is a minimally invasive procedure, it does carry a radiation risk. As radiation dose should be kept as low as reasonably achievable (ALARA), the main objective of this study was to analyse KAP (kerma area product), fluoroscopy and procedure time during the treatment of aneurysms treated with coiling and the Woven-EndoBridge (WEB) device. A secondary objective was to look at the reference air kerma (RAK) to determine if the patient receives a dose that could cause tissue effects.

[en] In order to clarify the mechanism of high proton conductivity (σ_H⁺) for superprotonic conductors, MHXO₄, where M=Cs and Rb, X=S and Se, μ⁺SR experiments have been performed in the temperature range between 250 and 450 K using single crystal samples. Here, MHXO₄ exhibits extraordinary high σ_H⁺ at T above its structural phase transition (T_c=414K for CsHSO₄) from a low-T monoclinic phase (Phase II) to a high-T tetragonal phase (Phase I). Since the asymmetry of weak transverse field (wTF) spectrum does not reach its maximum at ambient T, muonium (Mu) state is found to exist in both CsHSO₄ and CsHSeO₄. The Mu fraction in wTF spectrum for CsHSO₄ is still a finite value even in Phase I, while the Mu state disappears in Phase I of CsHSeO₄. The longitudinal field μ⁺SR measurements for observing the Mu state and its dynamics in CsHSO₄, show fast Mu diffusion and the conversion from Mu to diamagnetic μ⁺ in whole T range measured. Considering the fact that the σ_H⁺ in Phase I of CsHSO₄ is about 10 times larger than that of CsHSeO₄, the Mu formation in Phase I implies the presence of the atomic hydrogen state and play a possible crucial role for the high σ_H⁺ in Phase I of CsHSO₄.

[en] In order to clarify the variation of the microscopic magnetic nature with the carrier density in Na_xCoO₂.yH₂O, we have measured positive muon-spin rotation/relaxation (μ⁺SR) spectra for H₂O as well as D₂O absorbed samples. Based on the zero field (ZF-) μ⁺SR measurements, there was no clear difference between the two superconducting phases (SC-I and SC-II). Furthermore, the ZF-spectrum for the H₂O absorbed sample exhibits a clear oscillation in the whole T range measured (1.4-100 K), suggesting the formation of '[H₃O]⁺-like' H₂μ⁺O ions in the sample. Further, the absence of an oscillation in the D₂O absorbed sample also evidences the presence of H₂μ⁺O. We also measured ⁵⁹Co nuclear quadrupole resonance spectra of magnetic sample. The temperature dependence of spectra shows that there is no evidence of charge ordering and CDW ordering around magnetic transition temperature.

[en] In order to clarify the mechanism of high proton conductivity (σ_H+) for superprotonic ionic conductors, MHXO₄, where M=Cs and Rb, X=S and Se, muon-spin rotation and relaxation (μ⁺SR) and quasi-elastic neutron scattering (QENS) measurements have been performed at temperatures mainly in the vicinity of T_c, at which MHXO₄ undergoes a structural phase transition from a low-T orthorhombic phase (Phase II) to a high-T tetragonal phase (Phase I). The μ⁺SR experiment shows the presence of muonium (Mu) state even in Phase I only for CsHSO₄ (CHS), while no Mu state was found in Phase I of CsHSeO₄ (CHSe). Considering the fact that the σ_H+ in Phase I of CHS is more than 10 times larger that of CHSe, this implies a relationship between the presence of the atomic hydrogen (Mu) state and high σ_H+ in Phase I of CHS. According to the QENS measurements using a single crystal of CHSe, line shapes of the energy spectra along three crystallographic directions are found to be slightly anisotropic in Phase I, in contrast to the isotropic conductivity reported by AC conductivity measurements.