Fabrication of Tb-Mg codoped CaSnO3 perovskite thin films and electroluminescence devices

Thin films of CaSnO₃:Tb-Mg perovskite phosphor were prepared on silica glass substrates or SrTiO₃ (100) single crystal substrates by RF sputtering method. Intense green photoluminescence originating from Tb ions was observed from the films under uv (λ_ex = 254 nm) excitation. Furthermore, electroluminescence devices using the CaSnO₃:Tb-Mg phosphor were fabricated and their luminescence properties were examined. The device fabricated on the SrTiO₃ substrate showed electroluminescence above an applied ac voltage of 500 V and green electroluminescence was clearly observed from the CaSnO₃:Tb-Mg phosphor layer. Essence of the electroluminescence in the present devices was discussed along with an estimation of the electric field strength in the phosphor layer.     

Hydrogen and methane potential based on the nature of food waste materials in a two-stage thermophilic fermentation process

The purpose of this study is to investigate the biological H₂ and CH₄ potential based on the nature of organic waste materials in a two-stage thermophilic fermentation process. Three varieties of actual waste specifically potato, kitchen garbage and bean curd manufacturing waste (okara) were selected. The production rates for H₂ and CH₄ were as follows: potato, 2.1 and 1.2 l/l/d; garbage, 1.7 and 1.5 l/l/d; okara, 0.4 and 1.4 l/l/d in the continuous processes. The H₂ and CH₄ yields were 20–85 ml H₂/g VS_added and 329–364 ml CH₄/g VS_added, respectively. The H₂ yield increased and the CH₄ yield decreased in the order of potato, kitchen garbage and okara. The H₂ yield was shown to be not only dependent on the proportion of carbohydrate but also on the hydrolysis pH of the organic waste, which was influenced by the nature of the organic waste materials. Higher yields of H₂ or CH₄ were obtained when the hydrolysis pH of the organic waste was close to the optimum pH range of H₂-producing bacteria or methanogenic archaea in the two-stage fermentation processes.     

Photovoltaic performance of dye-sensitized solar cells stained with black dye under pressurized condition and mechanism for high efficiency

A porous TiO₂ layer was stained with black dye (BD) under a pressurized CO₂ atmosphere. Jsc of the cell (20.66 mA/cm²) was higher than that prepared by a conventional dipping process (18.96 mA/cm²). The higher Jsc was explained by the decrease in surface-state density on the nano-porous TiO₂ layer. In addition, BD aggregation was found to be retarded under the pressurized CO₂ condition, which is also associated with the higher Jsc. These phenomena were explained by the low BD concentration in the CO₂ fluid, the swift reaction rate between TiOH and HOCO dye, and the high diffusion coefficient of BD molecules into porous TiO₂ layers.     

Hierarchical Three-Dimensional Layer-by-Layer Assembly of Carbon Nanotube Wafers for Integrated Nanoelectronic Devices

We report a general approach to overcome the enormous obstacle of the integration of CNTs into devices by bonding single-walled carbon nanotubes (SWNTs) films to arbitrary substrates and transferring them into densified and lithographically processable "CNT wafers". Our approach allows hierarchical layer-by-layer assembly of SWNTs into organized three-dimensional structures, for example, bidirectional islands, crossbar arrays with and without contacts on Si, and flexible substrates. These organized SWNT structures can be integrated with low-power resistive random-access memory.     

Selective detection of biogenic amines using capillary electrochromatography with an on-column derivatization technique

A selective detection method for biogenic amines present in highly complex matrixes was devised by employing both electrokinetic injection and on-column-derivatization capillary electrochromatographic methods. The on-column derivatization capillary electrochromatography system was evaluated by use of a capillary column (total length of 45 cm, effective length of 25 cm) fabricated using a 100-mcirom (i.d.) fused-silica capillary tube packed with 5-microm (i.d.) ODS particles that were tolerant of an alkaline environment. The column was filled with a run buffer consisting of a derivatization reagent, o-phthalaldehyde/2-mercaptoethanol, in a mixture of borate buffer (pH 10). After electrokinetic injection of a mixture of five biogenic amines (histamine, serotonin, tyramine, putrescine, cadaverine) as a test sample, the free amines entered into the anodic site of the capillary column and started to travel along the column, during which time the analytes reacted with the derivatization reagent, separated out, and were detected with an absorbance at 340 nm when high voltage was applied to the column. When this system was applied to a mixture containing 5 biogenic amines and 17 amino acids, the 5 biogenic amines plus arginine selectively entered into the capillary with the electrokinetic injection and were observed on the electrochromatogram, but none of the amino acids lacking arginine were detected. The designated method was also tested for its ability to determine the presence of biogenic amines in the crude extracts obtained from two types of aged fish.     

Highly sensitive real-time PCR assay for quantification of toxic cyanobacteria based on microcystin synthetase A gene

The presence of cyanobacterial bloom in water supply reservoirs can cause potential health hazards. In this study, we aimed at the quantification of microcystin-producing cyanobacteria based on the microcystin synthetase A (mcyA) gene using real-time PCR. To perform a highly sensitive real-time PCR assay, the novel primer MSR-2R was designed and a coprecipitation DNA extraction method was used in this study. Cyanobacterial cells could be collected efficiently by coprecipitation with other bacteria suspended in solution even in the case of low concentrations of cyanobacteria. The detection limit of the method was found to be 8.8 cells per reaction. When cyanobacterial growth was monitored in pure culture, the cell concentration determined by real-time PCR positively correlated with the cell concentration determined from direct microscopic count. Furthermore, we could detect and quantify the mcyA gene in lake water samples using real-time PCR. It was concluded that the quantification of the mcyA gene based on real-time PCR is a powerful tool for the rapid quantification of microcystin-producing cyanobacteria in environmental samples.     

Porphyromonas gingivalis Components/Secretions Synergistically Enhance Pneumonia Caused by Streptococcus pneumoniae in Mice

Streptococcus pneumoniae is an important causative organism of respiratory tract infections. Although periodontal bacteria have been shown to influence respiratory infections such as aspiration pneumonia, the synergistic effect of S. pneumoniae and Porphyromonas gingivalis, a periodontopathic bacterium, on pneumococcal infections is unclear. To investigate whether P. gingivalis accelerates pneumococcal infections, we tested the effects of inoculating P. gingivalis culture supernatant (PgSup) into S. pneumoniae-infected mice. Mice were intratracheally injected with S. pneumoniae and PgSup to induce pneumonia, and lung histopathological sections and the absolute number and frequency of neutrophils and macrophages in the lung were analyzed. Proinflammatory cytokine/chemokine expression was examined by qPCR and ELISA. Inflammatory cell infiltration was observed in S. pneumoniae-infected mice and S. pnemoniae and PgSup mixed-infected mice, and mixed-infected mice showed more pronounced inflammation in lung. The ratios of monocytes/macrophages and neutrophils were not significantly different between the lungs of S. pneumoniae-infected mice and those of mixed-infected mice. PgSup synergistically increased TNF-α expression/production and IL-17 production compared with S. pneumoniae infection alone. We demonstrated that PgSup enhanced inflammation in pneumonia caused by S. pneumoniae, suggesting that virulence factors produced by P. gingivalis are involved in the exacerbation of respiratory tract infections such as aspiration pneumonia.     

水生植物床预处理富营养化水源水中试研究

水生植物床是一种无基质型人工湿地系统 ,利用植物根系吸收、过滤及共生生物的降解作用对水质进行净化。中试研究考察了水生植物床预处理富营养化水源水的效果。结果表明在原水水质为NH3-N 0 75～ 1 6 1mg/L ,浊度 15～ 113NTU ,UV2 54 0 0 4 2～ 0 135cm- 1的条件下 ,NH3-N ,浊度及UV2 54 的平均去除率分别为 30 % ,90 %和 8 8% ;对藻类和CODMn的平均去除率呈季节性变化 ,夏秋季原水藻密度 7 5× 10 5～ 5 14× 10 7个 /L ,CODMn6 4 2～ 15 37mg/L时 ,去除率分别达到90 %和 2 0 %以上 ;冬季原水Chl- a 7～ 2 9 6 μg/L ,CODMn5 35～ 9 2 3mg/L时去除率分别为 85 3%和 11%。