Dependence of ion selectivity on ordered orientation of neutral carriers in ion-sensing membranes based on thermotropic liquid crystals

Thermotropic liquid-crystalline compounds were applied as membrane materials (membrane solvent and neutral carrier) for neutral carrier-type ion sensors to investigate how the ordered arrangement of neutral carriers affects the property of the resulting ion sensors. Nematic, smectic, and cholesteric liquid-crystalline compounds were used as the membrane solvents and crown ether derivatives with a molecular structure similar to the liquid-crystalline solvent as the K+ neutral carriers. Polarized IR spectroscopy and X-ray diffraction experiments confirmed that the highly ordered arrangement of membrane components was retained in the liquid-crystal-based ion-sensing membranes containing a neutral carrier and a lipophilic salt. The ordered arrangement of neutral carriers in the liquid-crystalline membranes enhanced the ion selectivity significantly, probably due to the efficient cooperation of two adjacent crown ether moieties in the highly ordered and aggregated state.     

Optical neurochip with learning capability

A dynamic optical neurochip with variable synaptic interconnection capability has been reported. A novel type of photodetector called a variable sensitivity photodetector has been developed for the synaptic interconnection of neural networks. It utilizes a metal-semiconductor-metal structure whose quantum efficiency can be modulated by an applied bias voltage. The fabricated dynamic optical neurochip consists of an 8×8 variable sensitivity photodetector (VSPD) array and an 8 line-shaped LED array. It is shown that this device is suitable for learning in neural networks. The application to pattern classification is demonstrated     

Hearing recovery in sudden deafness with profound hearing loss

To more completely describe acromion morphology and its relationship to impingement syndrome, we performed three-dimensional magnetic resonance imaging (N = 111) or computed tomography (N = 27) on 132 symptomatic shoulders. The mean patient age was 46.2 years (range, 14 to 86). Four parameters were evaluated: the angle of anterior slope of the acromion in the midsagittal and lateral-sagittal planes, lateral acromial angulation in the coronal plane, and the presence or absence of medial encroachment in the acromioclavicular joint. Twenty-five asymptomatic age-matched shoulders were used as controls. All imaging data were combined because no significant differences existed between the two imaging techniques. The mean acromion angle was 19.4 degrees in the midsagittal plane and 20 degrees in the lateral-sagittal plane. In the coronal plane, 97 (73%) acromions were neutral and 35 (27%) were downward sloping. Medial encroachment was present in 31 (24%) shoulders. Age distribution from the 2nd to 8th decade demonstrated a consistent and gradual transition from a flat acromion in the younger decades to a more hooked acromion in the older decades that was significant in both the midsagittal and lateral-sagittal planes. Furthermore, a greater percentage of patients were found to have downward angulating acromions with increasing age. Ninety-eight patients (74%) had stage II or III impingement. Of these shoulders, 39 (40%) had type I acromions, 51 (52%) type II, and 8 (8%) type III. Twenty-eight of 33 acromions with coronal lateral downward sloping had impingement, and all 31 shoulders with medial encroachment had impingement.     

Effect of applied voltage frequency on swarming pulsive microdischarges in closed voids

The extinction of the partial discharge (PD) pulse has frequently been observed in an epoxy specimen with a closed void during voltage endurance tests using a CIGRE Method-II electrode. The individual discharge pulse becomes so small that the discharges cannot be detected by conventional pulse detection methods. Such discharges are known as “swarming pulsive microdischarges” (SPMD). In this paper, the SPMD characteristics are investigated by varying the frequency of the applied voltage from 0.1 to 240 Hz. As a result, the SPMD are found to occur less frequently as the frequency is lowered. To seek this cause, one-shot voltages were applied repeatedly at constant intervals. By varying the interval from 0.02 to 100 s, the PD off an electrically aged specimen was measured. It was revealed that the discharge magnitude increases as the interval becomes longer. The onset of SPMD was found to depend on the preceding discharge. The results explain the reason why swarming is harder to occur at lower frequency with a longer discharge interval. Hence, in the conventional pulse detection, it is useful to employ the very low frequency for diagnosis of machine insulation containing enclosed voids.     

Co gas detection by ThO2-Doped SnO2

The selective detection of CO gas by stannic oxide incorporated with ThO2(l − 10 wt%), in the presence of H2 and petroleum gases such as C₃H₈ and iso-C₄H₂ has been studied. Materials mixed with 5 wt% ThO₂ showed high selectivity to CO gas at a sample temperature of 200−250‡C. The effects of hydrophobic or hydrophilic silica present in the samples on the detection sensitivity to CO gas have been investigated. From the results it is apparent that the removal of the hy-droxyl radical from the surface of SnO₂ enhances the sensitivity to CO gas.     

The Oxidation behavior of an iron-chromium alloy containing yttrium or rare earth elements between 900° and 1200°C

The oxidation behavior of an Iron-15 wt pct Chromium alloy, some containing small additions of yttrium or rare earth elements, have been observed using a TG and an EPMA method at temperatures between 900° and 1200°C. Yttrium or rare earth element additions to the Iron-Chromium alloy result in a rapid initial oxidation rate, but decrease the total weight gain of the Iron-Chromium alloy at the final time of exposure. The line trace obtained indicates that the increased segregation of chromium content in the inner oxide layer of the alloy containing yttrium or rare earth elements and also shows that the enriched concentration of yttrium or lanthanum is detected within the chromium oxides which exist near the oxide scale/alloy matrix interface. Yttrium or rare earth element oxides serve as the sites for the protective chromium oxide scales.     

Simple plunge freezing applied to plant tissues for capturing the ultrastructure close to the living state

In order to observe the ultrastructure close to the living state, simple plunge freezing in liquid propane was applied to plant tissues. The method yielded a well-preserved ultrastructure to a depth of up to 40 microm from the surface of the young pea leaves, which were used as the specimen. Within the well-frozen area all membranes appeared smooth and the ultrastructural details of each organelle were similar to those obtained by high-pressure freezing. Several physical connections between the membranes were visualized. The relative simplicity and the satisfactory freezing performance of the method render it suitable for capturing the features of actively functioning cells in routine ultrastructural studies.     

Study on anisotropy of growth rate of ice crystal in supercooled water

The purpose of this research was to investigate the ice growth of a single crystal in three dimensions. Three-dimensional pattern of ice crystal growth in supercooled water was observed using Mach–Zehnder spectro-interferometer. Temperature was varied from −0.3 to −1.6 °C. It was found that the ice crystal began to grow as a single crystal at the tip of the capillary tube and propagated freely in supercooled water. Time variation of the shape of dendrite on a–c plane was obtained. It was found that half parabola fits the shape very closely, and the coefficient of squared term, a, of a quadratic function was calculated. The coefficient, a varied in time but at quasi steady state it was found to be depending mostly upon the degree of supercooling. Furthermore, the growth velocity in c-axis at the flat surface was calculated from the thickness measured. It was found that the velocity in c-axis is independent of the degree of supercooling but depends upon time, in other words, the thickness in c-axis.     

Occurrence,horizontal transfer and degeneration of VDE intein family in Saccharomycete yeasts

VDE is a homing endonuclease gene originally discovered as an intervening element in VMA1s of Saccharomyces cerevisiae. There have been two independent subfamilies of VDE, one from S. cerevisiae strain X2180-1A and the other from Saccharomyces sp. DH1-1A in the host VMA1 gene, and they share the identity of 96.3%. In order to search the occurrence, intra/interspecies transfer and molecular degeneration of VDE, complete sequences of VMA1 in 10 strains of S. cerevisiae, eight species of saccharomycete yeasts, Candida glabrata and Kluyveromyces lactis were determined. We found that six of 10 S. cerevisiae strains contain VDEs 99.7-100% identical to that of the strain X2180-1A, one has no VDE, whereas the other three harbour VDEs 100% identical to that of the strain DH1-1A. S. carlsbergensis has two VMA1s, one being 99.8% identical to that of the strain X2180-1A with VDE 100% identical to that of the strain DH1-1A and the other containing the same VMA1 in S. pastorianus with no VDE. This and other evidence indicates that intra/interspecies transmissions of VDEs have occurred among saccharomycete yeasts. Phylogenetic analyses of VMA1 and VDE suggest that the S. cerevisiae VDEs had branched earlier than other VDEs from an ancestral VDE and had invaded into the host loci as relatively late events. The two VDEs seemed to degenerate in individual host loci, retaining their splicing capacity intact. The degeneration of the endonuclease domains was distinct and, if compared, its apparent rate was much faster than that of the protein-splicing domains.     

Structural Control of Rashba Spin–Orbit Coupling in In0.52Al0.48As/In0.53Ga0.47As/In0.52Al0.48As Quantum Wells

We investigated the correlation between the Rashba spin–orbit coefficient and potential shape of the quantum wells (QW), where values are experimentally deduced from the weak antilocalization analysis. We studied the gate I–V properties of the QW samples and have obtained results consistent with the potential shapes predicted for these QWs.