Atomic-Level Understanding toward a High-Capacity and High-Power Silicon Oxide (SiO) Material

Silicon oxide (SiO) has attracted much attention as a promising anode material for Li-ion batteries. The lithiation of SiO results in the formation of active Li–Si alloy cores embedded in an inactive matrix consisting of Li-silicates (Li₂Si₂O₅, Li₆Si₂O₇, and Li₄SiO₄) and Li₂O. The maximum Li content in lithiated SiO (Li_<i>x</i>SiO) is known to be <i>x</i> = 4.4 based on experiments. Our calculations reveal that Li-silicates are dominant over Li₂O among matrix components of the experimental Li_4.4SiO phase. We show that Li_<i>x</i>SiO can become thermodynamically more stable and thus accommodate more Li ions up to <i>x</i> = 5.2 when Li₂O dominates over Li-silicates. The minor portion of Li₂O in the experimental phase is attributed to kinetically difficult transformations of Li-silicates into Li₂O during electrochemical lithiation. The Li₂O subphase can act as a major transport channel for Li ions because the Li diffusivity in Li₂O is calculated to be faster by at least 2 orders of magnitude than in Li-silicates. We suggest that Li₂O is a critical matrix component of lithiated SiO because it maximizes the performance of SiO in terms of both capacity and rate capability

Visualization 1.mp4

3D whole-eye OCT image of the left eye of a 26-year-old volunteer, containing the visual axis, the optical axis, and the pupillary axis

Morphological correlation between caloric tests and vestibular hydrops in Ménière's disease using intravenous Gd enhanced inner ear MRI

<div><p>The purpose of this study was to prove the hypothesis that caloric response in Ménière's disease (MD) is reduced by hydropic expansion of the vestibular labyrinth, not by vestibular hypofunction, by evaluating the correlation morphologically using an intravenous Gadolinium (IV-Gd) inner ear MRI. In study I, the prevalence of abnormal video Head Impulse Test (vHIT) results among the patients with definite unilateral MD (n = 24) and vestibular neuritis (VN) (n = 22) were investigated. All patients showed abnormal canal paresis (CP) (> 26%) on caloric tests. The prevalence of abnormal vHIT in patients with abnormal CP was significantly lower in MD patients (12.5%) than that in VN patients (81.8%) (<i>p</i> < 0.001). In study II, morphological correlation between caloric tests and vestibular hydrops level was evaluated in unilateral MD patients (n = 16) who had normal vHIT results. Eleven patients (61%) had abnormal CP. After taking the images of IV-Gd inner ear MRI, the vestibular hydrops ratio (endolymph volume/total lymph volume = %VH) was measured. In addition, the relative vestibular hydrops ratio (%RVH = (%VHaffected ear—%VHunaffected ear) / (%VHaffected ear + %VHunaffected ear)) was calculated. Each ratio (%VH and %RVH) was compared with average peak slow phase velocity (PSPV) and CP, respectively. In the MD patients, %VH of the affected ear correlated significantly with mean PSPV on the same side (rs = -0.569, <i>p</i> = 0.024), while %RVH correlated significantly with CP (rs = 0.602, <i>p</i> = 0.014). In most MD patients (87.5%) compared to VN patients, vHIT results were normal even though the caloric function was reduced. In addition, the reduced caloric function with normal vHIT was related to the severity of the vestibular hydrops measured by the IV-Gd inner ear MRI. These findings concluded that the abnormal caloric tests with normal vHIT in MD indicated severe endolymphatic hydrops rather than vestibular hypofunction.</p></div

Scatter plots of the vestibular hydrops ratio and caloric response.

<p>X-axis represents caloric response which was defined as the average of peak slow phase velocity (PSPV) of nystagmus following warm and cold irrigation in each ear, while Y-axis represents the vestibular hydrops ratio. Results of scatter plots are shown in circle (●) for affected ears. rs, Spearman correlation coefficient; p, significance. An asterisk (*) indicates significant relationship.</p

MR cisternography (MRC) and HYDROPS2 imaging of two unilateral MD patients.

<p>MRC demonstrates regular anatomy of fluid filled spaces of the inner ears of subject 5 (a, d) and subject 11 (e, h). Both subject 5 (a-d) and 11 (e-h) have unilateral ear symptom on the right side and vestibular hydrops are observed in the affected ears (b, f). Additionally, asymptomatic vestibular hydrops in the affected side is observed in subject 11 (g, arrow).</p

Vestibular hydrops ratio in affected and unaffected ears.

<p>Vestibular hydrops ratios (%VH) were measured to be 72.5% ± 21.8% in affected ears and 16.9% ± 19% in unaffected ears. An asterisk (*) indicates significant difference.</p

Demographic characteristics of patients with definite unilateral Ménière's disease in Study II.

<p>Demographic characteristics of patients with definite unilateral Ménière's disease in Study II.</p

Structure and Dynamic Behavior of the Na–Crown Ether Complex in the Graphite Layers Studied by DFT and ¹H NMR

Diffusion of alkali metals in graphite layers is significant for the chemical and electrochemical properties of graphite intercalation compounds (GICs). Crown ethers co-intercalate into graphite with alkali metal (Na and K) cations and form ternary GICs. The structures and molecular dynamics of 15-crown-5 and 18-crown-6 ether coordinating to Na⁺ or K⁺ in GICs were investigated by DFT calculations and ¹H solid state NMR analyses. DFT calculations suggest a stacked structure of crown ether–metal complex with some offset. ¹H NMR shows two kinds of molecular motions at room temperature: isotropic rotation with molecular diffusion and axial rotation with fluctuation of the axis. The structure and dynamics of crown ether molecules in GIC galleries are strongly affected by the geometry of the crown ether molecules and the strength of the interaction between alkali metal and ligand molecules

Visualization 2: In vivo photothermal treatment with real-time monitoring by optical fiber-needle array

Demonstration of PTT and the real-time monitoring with OFNA. Originally published in Biomedical Optics Express on 01 July 2017 (boe-8-7-3482