Publications by authors named "Junichi Hirota"

Direct laser writing (DLW) via two-photon absorption (TPA) has attracted much attention as a new microfabrication technique because it can be applied to fabricate complex, three-dimensional (3D) microstructures. In this study, 3D microstructures and micro-optical devices of micro-lens array on the micrometer scale are fabricated using the negative photoresist SU-8 through TPA with a femtosecond laser pulse under a microscope. The effects of the irradiation conditions on linewidths, such as laser power, writing speed, and writing cycles (a number of times a line is overwritten), are investigated before the fabrication of the 3D microstructures.

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Theileria orientalis is a causative agent of benign theileriosis in cattle and distributed in mainly Asian countries. In the present study, we examined the prevalence of T. orientalis infection by PCR based on the major piroplasm surface protein gene (MPSP) sequences in cattle in Myanmar, followed by phylogenetic analysis of the MPSP genes.

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Tritrichomonas suis (=T. foetus) has recently been reported to be a causative agent of chronic large-bowel diarrhea in cats. While the disease was previously attributed to Pentatrichomonas hominis, the etiologic agent for feline trichomonal diarrhea was identified as T.

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We performed experimental studies on the convolution/superposition method reported in the former companion paper (Iwasaki in Radiol Phys Technol 4, 2011) using 10-MV X-ray beams from open-jaw-collimated fields. The method uses primary and scatter dose kernels formed for energy bins of X-ray spectra reconstructed as a function of off-axis distance. We made a comparison of calculations and measurements in water phantoms and thorax-like phantoms with respect to percentage depth dose curves, tissue-phantom ratio curves, and dose profiles.

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A convolution/superposition method is proposed for use with primary and scatter dose kernels formed for energy bins of X-ray spectra reconstructed as a function of off-axis distance. It should be noted that the number of energy bins is usually about ten, and that the reconstructed X-ray spectra can reasonably be applied to media with a wide range of effective Z numbers, ranging from water to lead. The study was carried out for 10-MV X-ray doses in water and thorax-like phantoms with the use of open-jaw-collimated fields.

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In this study, the sensitivity in the diagnostic X-ray region of the single crystalline Si photovoltaic solar panel, which is expected to grow further, was measured by using an X-ray tube. The output voltage of the solar panel was clearly proportional to the tube voltage and a good time response in the irradiation time setting of the tube was measured. The factor which converts measured voltage to irradiation dose was extracted experimentally using a correction filter to investigate the ability of the solar panel as a dose monitor.

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Current chemotherapeutic options for African trypanosomiasis in humans and livestock are very limited. In the present study, a total of 71 medicinal plant specimens from 60 plant species collected in Myanmar were screened for antitrypanosomal activity against trypomastigotes of Trypanosoma evansi and cytotoxicity against MRC-5 cells in vitro. The methanol extract of dried rootbark of Vitis repens showed the highest antitrypanosomal activity with IC(50) value of 8.

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Radiographic noise properties have been evaluated using the Wiener spectrum. However, this approach is not appropriate for periodic noise for two reasons. One is that it takes infinite values at the spatial frequencies of periodic noise.

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Graphic noise properties are usually evaluated using the Wiener spectrum. However, this approach is not appropriate for periodic noise for two reasons. One is that it takes infinite values at the spatial frequencies of periodic noise.

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