Facing target sputtered iron-silicide thin film

The FeSi_x thin films with the flatness to an atomic scale for mechanical and optical applications can be grown by a facing target sputtering method. Optical properties indicate the films contain nano-crystalline FeSi₂. The nano-indentation hardness of 10 GPa was obtained. An interesting point is that Young's modulus is larger than that of the carbon-based materials with the same hardness. This means that the FeSi_x is more elastic, which could be characteristic of the chemical bonding of the FeSi₂ with the large contribution of d-electrons. Furthermore, results of the Hall measurement at room temperature shows that the films have p-type conductivity, a carrier concentration of p = 2.49 × 10²⁰ cm^− 3 and a Hall mobility of μ = 6.42 cm² V^− 1 s^− 1.     

Atomic hydrogen emission induced by TEA CO(2) laser bombardment on solid samples at low pressure and its analytical application

Hydrogen emission has been studied in laser plasmas by focusing a TEA CO(2) laser (10.6 microm, 500 mJ, 200 ns) on various types of samples, such as glass, quartz, black plastic sheet, and oil on copper plate sub-target. It was found that H(alpha) emission with a narrow spectral width occurs with high efficiency when the laser plasma is produced in the low-pressure region. On the contrary, the conventional well-known laser-induced breakdown spectroscopy (LIBS), which is usually carried out at atmospheric air pressure, cannot be applied to the analysis of hydrogen as an impurity. By combining low-pressure laser-induced plasma spectroscopy with laser surface cleaning, a preliminary quantitative analysis was made on zircaloy pipe samples intentionally doped with hydrogen. As a result, a good linear relationship was obtained between H(alpha) emission intensity and its concentration.     

Lifelong severe verrucosis associated with human papillomavirus type 2: report of a case with a 38-year follow-up

Sulfite ion (HSO3-) is one of the products when elemental sulfur is oxidized by the hydrogen sulfide:ferric ion oxidoreductase of Thiobacillus ferrooxidans AP19-3. Under the conditions in which HSO3- is accumulated in the cells, the iron oxidase of this bacterium was strongly inhibited by HSO3-. Since cytochrome c oxidase is one of the most important components of the iron oxidase enzyme system in T. ferrooxidans, effects of HSO3- on cytochrome c oxidase activity were studied with the plasma membranes of HSO3(-)-resistant and -sensitive strains of T. ferrooxidans, OK1-50 and AP19-3. The enzyme activity of AP19-3 compared with OK1-50 was strongly inhibited by HSO3-. To investigate the inhibition mechanism of HSO3- in T. ferrooxidans, cytochrome c oxidases were purified from both strains to an electrophoretically homogeneous state. Cytochrome c oxidase activity of a purified OK1-50 enzyme was not inhibited by 5 mM HSO3-. In contrast, the same concentration of HSO3- inhibited the enzyme activity of AP19-3 50%, indicating that the cytochrome c oxidase of OK1-50 was more resistant to HSO3- than that of AP19-3. Cytochrome c oxidases purified from both strains were composed of three subunits. However, the molecular weight of the largest subunit differed between OK1-50 and AP19-3. Apparent molecular weights of the three subunits of cytochrome c oxidases were 53,000, 24,000, and 19,000 for strain AP19-3 and 55,000, 24,000, and 19,000 for strain OK1-50, respectively.     

Photo‐response orientation behaviors of polyethylene imine backbone structures with azobenzene side chains

Polyethylene imines (PEIs) with azobenzene side groups, PEI6M and IP‐DAz, were synthesized and the effects of the substitution degree of the PEI backbone structures on the photoresponse properties and the orientation behaviors were investigated. The phase transition temperatures are closely related to thermal stability in orientational order. IP‐DAz showed only the smectic phase in a much broader range between 53 °C and 170 °C and the thermal stability was significantly improved compared with PEI6M. Reversible changes in absorption spectra relating to photoisomerization behavior for both polymers were observed by UV and visible light irradiation. Uniaxial orientation for the selective direction was induced by irradiation by linearly polarized light and the anisotropic properties were investigated by measurements of the order parameter and birefringence. Rapid photoresponses for molecular orientations were demonstrated for both polymers. Although the order parameter of IP‐DAz was lower than that of PEI6M, the birefringence of IP‐DAz for in‐plane orientation was as high as for PEI6M and is related to the stable orientational order. © 2013 Society of Chemical Industry     

Observations on microstructure and crystal structure of sintered lithium metatitanate with excess Li

Crystal grain growth and crystallization of lithium metatitanate with excess Li (Li_2+xTiO_3+y), which is expected as an advanced ceramic breeder for a future DEMO fusion reactor, were studied in this paper. By the observation of sintered pellets using scanning electron microscope, it was shown that the Li_2.1TiO_3+y specimens, which have small grains (1–2 μm) and narrow size distribution, can be obtained by sintering in the temperature range from 1000 to 1100 °C. The observation also showed the rapid grain growth in the Li_2.1TiO₃ specimens sintered above 1150 °C. The changes in the crystal structure and the phase transformation with the increase of sintering temperature were also investigated by means of powder X-ray diffraction. Finally, the relationship between the grain growth and the phase state at high temperature was discussed.     

In vitro assessment of the cytotoxicity of anti-allergic eye drops using 5 cultured corneal and conjunctival cell lines

The aim of this study was to evaluate the cytotoxicity of anti-allergic eye drops for human corneal endothelial cells (HCEC) and commercially available ocular surface cells. A primary HCEC culture was derived from human eye bank specimens. SIRC (rabbit corneal epithelium), BCE C/D-1b (bovine corneal epithelial cells), RC-1 (rabbit corneal epithelium), and Chang (human conjunctival cells) were obtained commercially. The WST-1 assay was used to measure HCEC viability, and the viability of other cells was measured using the MTT assay. Cells were treated with 7 commercially available anti-allergic eye drops for 48 h and cell viability was measured and calculated as a percentage of control. The degree of toxicity for each eye-drop solution was based on the cell viability score (CVS). HCECs treated with a 1000-fold dilution of the eye-drop solution had a viability score of 67% for Rizaben and ≥80% for the other solutions with Zepelin being the least toxic. Cell viability in response to eye-drop solutions preserved with benzalkonium chloride (BAK) was dependent on the concentration of the drug solution and exposure time. Treatment of ocular surface cells with a 20-fold dilution of the eye-drop solution resulted in the following order of cell viability as determined by their CVS: Zepelin > Ketas = Zaditen ≥ Tramelas PF = Patanol ≥ Rizaben ≥ Livostin. This order was similar to that observed for HCECs, and cell viability was found to be concentration-dependent. Based on the penetration of the drug into eye tissues, HCECs are only likely to be pharmaceutically damaging in rare cases. Epithelial cell viability depends primarily on the concentration of BAK rather than on the action of the active component in the eye-drop solution. CVS values were useful for comparison of toxicity.     

Organic solvent based TiO<Subscript>2</Subscript> dispersion paste for dye-sensitized solar cells prepared by industrial production level procedure

In order to prepare the TiO₂ liquid dispersions for the electrodes of dye-sensitized solar cells with industrial mass production level at a reasonable cost, the present study investigates the preparation of TiO₂ liquid dispersions by a general industrial dispersion technique using readily available P25. To determine the TiO₂ dispersion offering the best light–electricity energy conversion efficiency, the suitability of various types of solvents and resins for use in TiO₂ dispersion are tested. In general, organic solvent based TiO₂ dispersions are found to allow the formation of more uniform thin films in comparison with water-based dispersions. A preparation using ethyl cellulose as the resin and the terpineol as the solvent is found to exhibit the best conversion efficiency. We have also found that using two kinds of resins of different molecular weights gave rise to better efficiency. Among 26 metal compounds tested in this study, the best metal dopant was Ag. XRD and XPS measurements confirm that the Ag exists as metal Ag and silver oxide.