Surface morphology control of zirconia thin films prepared using novel photochromic molecules

A new photochromic ZrO₂ precursor solution was prepared using zirconium tetra-n-butoxide, 4-(phenylazo)benzoic acid and ethyleneglycol monomethylether. The density functional theory (DFT) calculation has identified that the structure of the synthesized precursor molecule changed by UV irradiation. Four types of thin films were prepared using the ZrO₂ precursor solution with and without UV irradiation and applying an electric field. It was found that the surface morphology of thin films changed by applying UV irradiation to the precursor solution and an electric field.     

The Influence of Surface Chemistry and Pore Size on the Adsorption of Proteins on Nanostructured Carbon Materials

Carbon films are synthesized by templating of anodic aluminum oxide films. These carbon materials exhibit nanochannels with controlled diameter and length. Selected chemical treatments are done to tailor the surface chemistry. The adsorption capacities of bovine serum albumin and cytochrome c are measured by temperature‐programmed desorption with mass spectrometry (TPD‐MS) analysis and with conventional biological assays. The first method allows quantification of the proteins that exhibit strong interactions with the surface, while the second one is used to obtain the total adsorption capacity. Moreover, the TPD‐MS profiles, which are related to the structural modifications of the proteins during the adsorption, show that strong interactions take place with hydrophobic surfaces. When oxygenated functions are present, the adsorption capacity increases and the nature of the interactions is modified. The ratio of irreversible to reversible adsorption is significantly different for the two proteins, and is slightly related to the surface chemistry. The influence of nanochannel size is studied: below 50 nm, the coverage ratio shows that access to the porosity is limited by diffusion in the channel and by pore plugging, in agreement with the strong interactions of proteins with the carbon surface.     

Photoemission study of the tin doped cerium oxide thin films prepared by RF magnetron sputtering

Ce-Sn-O mixed oxide films prepared by simultaneous Sn metal and cerium oxide magnetron sputtering were studied by high resolution photoemission. The analysis showed that the degree of reduction of the cerium oxide depends on the tin concentration in the film. Ce⁴⁺ → Ce³⁺ conversion is explained by a charge transfer from Sn atoms to unoccupied orbital Ce 4f⁰ of cerium oxide by forming Ce 4f¹ state. The X-ray Photoelectron Spectroscopy data were compared with study of the single-crystalline CeO₂ thin films and Sn/CeO₂(111) model system prepared and studied in situ excluding air exposure effects.     

Room-temperature synthesis of tin oxide nano-electrodes in aqueous solutions

Tin oxide nano-electrodes were fabricated on fluorine doped tin oxide (FTO) substrates at room temperature. SnO₂ was crystallized from ions in aqueous solutions to cover the substrates uniformly. They were single phase of SnO₂ nano-crystals and about 5–10 nm in size. The surface coatings changed the surface morphology of FTO substrates to increase roughness and surface area. FTO substrates covered with tin oxide had the same transparency as bare FTO substrates in the range from 200 nm to 850 nm.     

Neck electrical impedance for measurement of swallowing

Recently, videofluorography has been used for evaluation of swallowing function in the rehabilitation field. But it is not easy to evaluate swallowing disorders simply. In addition, there are problems of exposure for daily use. We have proposed a measurement method of swallowing using bioelectrical impedance (impedance pharyngography, IPG) which has advantages of easy handling and noninvasive measurement. Appropriate electrode position have been determined. The waveforms of IPG can be obtained with some extent reproducibility. The change of neck electrical impedance in the pharyngeal phase is mainly caused by the changes of equivalent cross sectional area near the epiglottis. The possibilities of applications for clinical diagnosis have been shown. © 2000 Scripta Technica, Electr Eng Jpn, 130(4): 35–44, 2000     

Zinc oxide particles connected by nano-sheets and their heat treatment

Particulate films of crystalline ZnO connected by nano-sheets were fabricated in an aqueous solution. This study focused on the annealing behavior of the particulate films, especially the morphology change of the nano-sheets. The nano-sheets had a thickness of 10 nm to 50 nm and width of 1 μm to 10 μm. They were connected to particles closely with no clearance. Their morphology was changed to nanoparticles and porous particulate films of crystalline ZnO by annealing at 500 °C for 1 h in air. The morphology of the sheets changed due to their slimness and/or phase transformation. Crystallization and morphology control of crystalline ZnO at low temperature can be applied to a wide variety of devices supported by low-heat resistant polymer films and would contribute to the environmentally friendly fabrication of oxide devices.     

Urological assessment for tethered cord syndrome of delayed onset following repair of meningomyelocele

PURPOSE AND MATERIALS: Out of 84 patients with meningomyelocele repaired at birth, 14 (15. 7%) children (6 boys and 8 girls, average 8.8 year-old) who underwent cord untethering for tethered cord syndrome of delayed onset (Delayed TCS) were urologically evaluated. RESULTS: Eleven (78.5%) children were detected orthopedically by deterioration of lower extermities function and only 3 (21.5%) were detected urologically. Preoperative urodynamic study, however, revealed in 5 children aggravation of urinary tract dysfunction, including accelerated uninhibited contraction in 4, impaired bladder compliance in 3, decreased bladder capacity in 2 and recurrence of VUR in 1. Although there were no particular urinary symptom for detection of Delayed TCS, acceleration of uninhibited contraction seemed to be one of the most important findings. After untethering, deterioration or normalization of urological dysfunction was not seen. Six of 14 children had favorable clinical results, such as improvement of uninhibited contraction, increasing of bladder compliance and capacity, prolongation of dry time and disappearance of VUR. In 3 children Delayed TCS were detected by postoperative improvement of urinary tract function. Consequently, of 14 children who were evaluated preoperatively and postoperatively 8 (52. 7%) had urological impairment compatible with Delayed TCS. CONCLUSIONS: It is not easy to detect the urological deteriorations associated with Delayed TCS behind initial neuro-urological deficits. Careful and regular follow-up examinations are required to early detection of Delayed TCS. The fact that urinary tract dysfunction improved in some cases after untethering encourages aggressive surgical untehtering of Delayed TCS.     

Ku band electric models for large deployable mesh reflector antenna

Two scaled mesh reflector electric models have been constructed for the design of a 30 m diameter large deployable antenna. Radiation characteristics of the antennas have been measured and compared with calculated results. The similarities between measured and calculated results are very close. The cross-polarisation level especially is considerably low.<>     

Determination of miloxacin and metabolites in human serum and urine by high-pressure liquid chromatography

A sensitive and reliable high-pressure liquid chromatography (HPLC) assay for miloxacin and its two principal metabolites, 5,8-dihydro-8-oxo-2H-1,3-dioxolo[4,5-g]quinoline-7-carboxylic acid (M-1) and 1,4-dihydro-1,6-dimethoxy-7-hydroxy-4-oxoquinoline-3-carboxylic acid (M-2), in human serum and urine was developed. A strong anion-exchange Zipax SAX column using a mobile phase of 0.01 M citric acid solution containing 0.03 M sodium nitrate with pH 5.0 was used to achieve separation of the three compounds. The retention times of miloxacin, M-1, and M-2 were 3.8, 9.3, and 5.9 min, respectively. Serum and urine concentrations of these compounds as low as 10 ng/ml were measured. When results from the HPLC assay were compared with those from the microbiological assay of serum and urine samples from human subjects receiving miloxacin orally, the correlation coefficients were 0.94 for the serum and 0.99 for the urine. The HPLC assay method presents an alternative to the microbiological assay and permits future pharmacokinetic investigations of miloxacin.