94 research outputs found

    Production of Aquatic Organism Cultivation Kit and Its Development in STEAM Education

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    A Robust Fiber Bragg Grating Hydrogen Gas Sensor Using Platinum-Supported Silica Catalyst Film

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    A robust fiber Bragg grating (FBG) hydrogen gas sensor for reliable multipoint-leakage monitoring has been developed. The sensing mechanism is based on shifts of center wavelength of the reflection spectra due to temperature change caused by catalytic combustion heat. The sensitive film which consists of platinum-supported silica (Pt/SiO2) catalyst film was obtained using sol-gel method. The precursor solution was composed of hexachloroplatinic acid and commercially available silica precursor solution. The atom ratio of Si : Pt was fixed at 13 : 1. A small amount of this solution was dropped on the substrate and dried at room temperature. After that, the film was calcined at 500°C in air. These procedures were repeated and therefore thick hydrogen-sensitive films were obtained. The catalytic film obtained by 20-time coating on quartz glass substrate showed a temperature change 75 K upon exposure to 3 vol.% H2. For realizing robust sensor device, this catalytic film was deposited and FBG portion was directly fixed on titanium substrate. The sensor device showed good performances enough to detect hydrogen gas in the concentration range below lower explosion limit at room temperature. The enhancement of the sensitivity was attributed to not only catalytic combustion heat but also related thermal strain

    Improvement of acquisition and analysis methods in multi-electrode array experiments with iPS cell-derived cardiomyocytes

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    AbstractIntroductionMulti-electrode array (MEA) systems and human induced pluripotent stem (iPS) cell-derived cardiomyocytes are frequently used to characterize the electrophysiological effects of drug candidates for the prediction of QT prolongation and proarrhythmic potential. However, the optimal experimental conditions for obtaining reliable experimental data, such as high-pass filter (HPF) frequency and cell plating density, remain to be determined.MethodsExtracellular field potentials (FPs) were recorded from iPS cell-derived cardiomyocyte sheets by using the MED64 and MEA2100 multi-electrode array systems. Effects of HPF frequency (0.1 or 1Hz) on FP duration (FPD) were assessed in the presence and absence of moxifloxacin, terfenadine, and aspirin. The influence of cell density on FP characteristics recorded through a 0.1-Hz HPF was examined. The relationship between FP and action potential (AP) was elucidated by simultaneous recording of FP and AP using a membrane potential dye.ResultsMany of the FP waveforms recorded through a 1-Hz HPF were markedly deformed and appeared differentiated compared with those recorded through a 0.1-Hz HPF. The concentration–response curves for FPD in the presence of terfenadine reached a steady state at concentrations of 0.1 and 0.3μM when a 0.1-Hz HPF was used. In contrast, FPD decreased at a concentration of 0.3μM with a characteristic bell-shaped concentration–response curve when a 1-Hz HPF was used. The amplitude of the first and second peaks in the FP waveform increased with increasing cell plating density. The second peak of the FP waveform roughly coincided with AP signal at 50% repolarization, and the negative deflection at the second peak of the FP waveform in the presence of E-4031 corresponded to early afterdepolarization and triggered activity.DiscussionFP can be used to assess the QT prolongation and proarrhythmic potential of drug candidates; however, experimental conditions such as HPF frequency are important for obtaining reliable data

    Plasma Thrombopoietin Levels are Unlikely to Account for the Platelet-sparing Effect of Paclitaxel in Lung Cancer Patients

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    Purpose: The present study was designed to determine whether the combination of carboplatin (CBDCA) with paclitaxel (PTX) spared CBDCA-induced thrombocytopenia by increased plasma thrombopoietin (TPO) levels. Methods: Patients with non-small-cell and small-cell lung cancer were consecutively assigned to CBDCA with PTX regimen (CBDCA/PTX) and CBDCA with irinotecan (CPT-11) regimen (CBDCA/CPT-11), respectively. Results: Ten patients were entered into either CBDCA/PTX (n=5) or CBDCA/CPT-11 (n=5). CBDCA/PTX showed a lesser reduction of platelet counts than CBDCA/CPT-11 (p<0.05), although more severe neutropenia was observed in CBDCA/PTX (p<0.01). The plasma TPO levels were inversely correlated with circulating platelet counts in CBDCA/PTX and CBDCA/CPT-11. However, the increased rate of plasma TPO levels in CBDCA/PTX was not significantly different from that in CBDCA/CPT-11. Conclusions: These findings suggest that the increased plasma TPO levels in CBDCA/PTX result secondarily from thrombocytopenia, and that circulating TPO is probably not involved in the platelet-sparing effect of PTX
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