Photoelectrochemical study of lanthanide zirconium oxides, Ln2Zr2O7 (Ln = La, Ce, Nd and Sm)

Photocatalytic activities for hydrogen evolution of lanthanide zirconium oxides, Ln₂Zr₂O₇ (Ln = La, Ce, Nd and Sm) prepared by a solution reaction method were investigated. Under the illumination of 500 W Xenon lamps, hydrogen gas was clearly evolved in a distilled water suspension of La₂Zr₂O₇, Sm₂Zr₂O₇ and Nd₂Zr₂O₇. Under the visible-light illumination, hydrogen gas was evolved in a distilled water suspension of Nd₂Zr₂O₇ and Sm₂Zr₂O₇. From the photoelectrochemical measurements, the values of the flat band potential were estimated to be −0.64, −0.52, −0.31 and +0.04 eV for La₂Zr₂O₇, Sm₂Zr₂O₇, Nd₂Zr₂O₇ and Ce₂Zr₂O₇, respectively, versus the normal hydrogen electrode (NHE). The values of the band gap energy were calculated to be about 3.52, 2.86, 2.67 and 2.53 eV for La₂Zr₂O₇, Sm₂Zr₂O₇, Nd₂Zr₂O₇ and Ce₂Zr₂O₇, respectively. Due to the effect of 4f orbital electrons, the band gap energy of these compounds becomes narrower than in ZrO₂ and as a consequence, Sm₂Zr₂O₇ and Nd₂Zr₂O₇ show the photocatalytic activity under the visible-light.     

Higher levels of plasma cholesterol sulfate in patients with liver cirrhosis and hypercholesterolemia

An analytical method for the determination of cholesterol sulfate (CS) in plasma using gas-liquid chromatography was developed. We measured plasma CS concentrations in patients with liver cirrhosis and hypercholesterolemia as examples of disorders that involve aberrations in cholesterol metabolism. Patients with liver cirrhosis had plasma CS concentrations that were significantly higher than those of control subjects (444.6±51.7vs. 253.0±24.6 μg/dL, mean ±SE). The levels of other lipids were lower in cirrhotics, although the differences were not significant. There was no correlation between the levels of CS and sulfated bile acids in cirrhotic patients. CS levels in plasma were also higher in subjects with hypercholesterolemia (413.7±44.5 μg/gL) however, the ratio of CS to total cholesterol (TC) clearly differed between cirrhotics and hypercholesterolemic subjects (1.44±0.11×10⁻³,vs. 3.31 ±0.63×10⁻³;P<0.05). Both in subjects with hypercholesterolemia and in healthy controls, the CS/TC ratio was similar and CS accounted for roughly 0.14% of the TC concentration.     

Ultrasensitive Imaging of Ca2+ Dynamics in Pancreatic Acinar Cells of Yellow Cameleon-Nano Transgenic Mice

Yellow Cameleons are genetically encoded Ca²⁺ indicators in which cyan and yellow fluorescent proteins and calmodulin work together as a fluorescence (Förster) resonance energy transfer Ca²⁺-sensor probe. To achieve ultrasensitive Ca²⁺ imaging for low resting Ca²⁺ or small Ca²⁺ transients in various organs, we generated a transgenic mouse line expressing the highest-sensitive genetically encoded Ca²⁺ indicator (Yellow Cameleon-Nano 15) in the whole body. We then focused on the mechanism of exocytotic events mediated by intracellular Ca²⁺ signaling in acinar cells of the mice with an agonist and observed them by two-photon excitation microscopy. In the results, two-photon excitation imaging of Yellow Cameleon-Nano 15 successfully visualized intracellular Ca²⁺ concentration under stimulation with the agonist at nanomolar levels. This is the first demonstration for application of genetically encoded Ca²⁺ indicators to pancreatic acinar cells. We also simultaneously observed exocytotic events and an intracellular Ca²⁺ concentration under in vivo condition. Yellow Cameleon-Nano 15 mice are healthy and no significant deteriorative effect was observed on physiological response regarding the pancreatic acinar cells. The dynamic range of 165% was calculated from R_max and R_min values under in vivo condition. The mice will be useful for ultrasensitive Ca²⁺ imaging in vivo.     

A Genotoxic Stress-Responsive miRNA,miR-574-3p,Delays Cell Growth by Suppressing the Enhancer of Rudimentary Homolog Gene in Vitro

MicroRNA (miRNA) is a type of non-coding RNA that regulates the expression of its target genes by interacting with the complementary sequence of the target mRNA molecules. Recent evidence has shown that genotoxic stress induces miRNA expression, but the target genes involved and role in cellular responses remain unclear. We examined the role of miRNA in the cellular response to X-ray irradiation by studying the expression profiles of radio-responsive miRNAs and their target genes in cultured human cell lines. We found that expression of miR-574-3p was induced in the lung cancer cell line A549 by X-ray irradiation. Overexpression of miR-574-3p caused delayed growth in A549 cells. A predicted target site was detected in the 3′-untranslated region of the enhancer of the rudimentary homolog (ERH) gene, and transfected cells showed an interaction between the luciferase reporter containing the target sequences and miR-574-3p. Overexpression of miR-574-3p suppressed ERH protein production and delayed cell growth. This delay was confirmed by knockdown of ERH expression. Our study suggests that miR-574-3p may contribute to the regulation of the cell cycle in response to X-ray irradiation via suppression of ERH protein production.     

Visual and semantic processing in reading Kanji.

A. Nakagawa (see record 1992-15549-001) showed hemispheric asymmetries during semantic processing of single English words. The right hemisphere passively maintained both strong and weak associations, whereas the left hemisphere maintained only strong associations when Ss were left free to attend. The present study extends the methodology to the study of Kanji characters. Contrary to the study of English characters, there was a general right-hemisphere advantage in single-character Kanji words. A study using a visual cue to direct attention suggested that the right-hemisphere advantage of Kanji was due to better representation of visual features by the posterior right hemisphere. However, the pattern of semantic priming found in English was replicated. Semantic analysis, mediated by more anterior systems, appears similar in the 2 languages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of direct contact melting with hydrocarbon mixtures as the PCM

In this study, direct contact melting of hydrocarbon mixtures as phase change materials was investigated experimentally. Tetradecane and hexadecane binary mixtures, and pentadecane and octadecane binary mixtures were used as phase change materials, with various mixing ratios. It was found that the heat flux decreased significantly in the low surface temperature range. In addition, a rough and uneven melting surface was observed in the low surface temperature range. The convex portions at the melting surface were collected, and the ingredients of this region were measured by using differential scanning calorimetry (DSC). It was found that the DSC curve shifted to a higher temperature region, and the concentration of higher melting point material increased at the convex portions. Therefore, it seems that the melting point around the convex portions increased due to the higher concentration of higher melting point material, and this resulted in the decrease in the heat flux.     

Revealing the formation mechanism of granules by drying simulation of slurry droplet

The formation mechanism of granules in spray drying process was investigated by DEM-CIP method simulation coupled with a new binder segregation model. To confirm the validity of proposed binder segregation model, experiment on drying of aqueous slurry containing fine particles and binder was performed. The experimental concentration distribution of binder in a dried powder bed agreed well with the simulated one and this result shows that the proposed segregation model is valid to represent segregation phenomenon in the dried granule. Spherical hollow granules were formed with increasing of binder concentration, and the granules were depressed in higher concentration of binder. When the binder concentration in the surface region of a slurry droplet increased during drying, a crust of granule was formed because particle migration was hindered by high fluid viscosity. For the rigid crust layer, granules were hollow. When the crust layer was formed early in drying and its thickness was thin, granule surface partially collapsed inward, whereas the granule resulted in depression granules.     

Solid electrolyte films in controlling their structures by electrophoretic deposition method

Improvement of proton conductivity of solid electrolyte films needs to form three-dimensional proton conduction paths by controlling the pore size and the pore structure between particles in particle films. A particle assemble method using electrophoretic deposition technique is useful for speedy and mass production assembly. In the electrophoretic deposition method, structure of particle array can be controlled by the electric field.As a result, the proton conductivity of the film showed a higher value for the regularly-arranged particle film and it is increased with a decrease in particle diameter. The proton conductivity of the film with the particles of diameter 50 nm had the highest value. The particle film with the well-controlled structure may enable the fuel cell to be operated in the middle temperature range.     

Determination of Polycyclic Aromatic Hydrocarbons in the fecal Materials of Mactra veneriformis and Excrement of Marphysa sanguinea

The concentration of polycyclic aromatic hydrocarbons (PAHs) was measured in the sediment, a bivalve (Mactra veneriformis), fecal materials (feces and pseudofeces) of M. veneriformis, and excrement (feces) of an annelid (Marphysa sanguinea), which were collected in the Yoro tidal flat in Chiba, Japan. The total PAH concentration was 350 μg/kg-dry in the fecal materials of M. veneriformis and 977 μg/kg-dry in the excrement of M. sanguinea; these values were about 8–23 times as large as that of the sediment. The concentration of the fecal materials stayed constant even after 24 h, whereas that of the excrement decreased to half in 2 h. The sediment and fecal materials of M. veneriformis showed a high level of PAHs with lower molecular weight such as phenanthrene, fluoranthene, and pyrene; on the other hand, the excrement of M. sanguinea showed a high level of PAHs with higher molecular weight such as chrysene, benzo[b]fluoranthene, benzo[a]pyrene, and perylene. The logarithm of the concentration factor, defined as the ratio of the concentration of individual PAHs in the fecal materials or excrement to that in the sediment, correlated with the logarithm of the n-octanol/water partition coefficient for the PAHs (R ² = 0.803). These findings indicate that the sources and characteristics of the fecal materials of M. veneriformis and the excrement of M. sanguinea are different.