The detection method of gamma ray irradiated garlic using Electron Spin Resonance(ESR)spectroscopy was studied. The ESR spectrum was consisted of one singlet signal at g=2.00. This signal is due to an organic free radical. Upon irradiation, the intensity of the signal was increased. Also two signals due to cellulose radical were detected nearby the singlet. The intensity of the singlet signal was increased as depend on the increase of the irradiation dose level.
In this study, we applied support tool(Impara) for environmental parameter estimation to evaluation of radon and thoron exhalation rates from soil surface. This support tool was developed for estimation of soil-to-soil solution distribution coefficient(Kd) and soil-to-plant transfer factor(TF). As a result of multiple linear regression analysis, radium content in the soil, emanation coefficient, volumetric water content and soil temperature were important parameters for estimation of radon and thoron exhalation rates from soil surface. Comparisons of measured and estimated radon/thoron exhalation rates showed relatively good agreement.
We performed radionuclide cisternography in two patients suspected of having cerebrospinal fluid hypovolemia. One patient was a 31-year old male and the other a 34-year-old female. Radionuclide cisternography demonstrated extrathecal radiotracer accumulation, urinary bladder accumulation in an early phase, and decrease in radiotracer retention in the cerebrospinal space at 24 hours post injection, while brain MRI revealed no abnormal findings. Two patients were diagnosed as cerebrospinal fluid hypovolemia because of three observations mentioned above. Radionuclide cisternography is useful in diagnosing cerebrospinal fluid hypovolemia even if brain MRI shows no abnormal finding.
13C-glucose is consisted of carbon 13, stable isotope. Six carbons in glucose were converted to 13C. 13C-glucose breath test (13C-GBT) is useful for evaluating the cell viability and human metabolic function. It is assessed by 13CO2, metabolite of 13C-glucose, in exhausted gas samples. It is quickly measured by using an isotope ratio mass spectrometer (POC one, Otsuka Pharmaceutical Co. Ltd, Tokyo). In the study we made, we have assessed glucose metabolism in the reconstructed liver organoid using by 13C-GBT. We made a 3-dimentional reconstructed organoid (mini artificial liver model) using a radial-flow bioreactor(RFB), and evaluated viability of the organoid by 13C-GBT. The liver organoid was constructed by co-culture with immortalized mouse hepatocytes, sinusoidal endothelial cells and hepatic stellate cells. Exhaust gas was sampled in gas bags from the closed circuit of RFB system. Firstly we observed transition of 13CO2 in exhaust gas along culture time. Glucose metabolism was enhanced by not only hepatocyte growth, but co-culture of non-parenchymal cells. We also examined ischemia/reperfusion injury model in the reconstructed liver organoid. 13C-GBT clearly showed depressed metabolism by ischemic effect to the liver organoid. In conclusion, 13C-GBT is extremely useful for assessment of viability and glucose metabolism in real-time, easily and high sensitivity not only in vivo but in vitro.
Exchange coupling at the interface between an antiferromagnetic layer and a ferromagnetic layer results in a shift of a ferromagnetic hysteresis loop known as exchange bias. A new MnIr/CoFe exchange bias system is promising for magnetic devices since it produces a large exchange bias with a small layer thickness. To reveal the magnetic structure of the system, we performed a soft and hard X-ray resonant magnetic reflectometry at SPring-8 synchrotron radiation facility and a polarized neutron reflectometry at JRR-3 neutron source of Japan atomic energy agency(JAEA). From the data, the element specific depth profile of “rotatable” and “pinned” magnetic spin on the system and the rotation angle of magnetization vector in the ferromagnetic layer were obtained. Based on these results, we discusses the relation between the spin distribution and exchange bias of the MnIr/CoFe bilayer system.
Diamond-like carbon (DLC) is an amorphous material with an intermediate chemical structure between diamond and graphite. While the DLC coatings show low friction and little wear, the tribological properties are improved by doping of silicon. Since the effect of the silicon on the improvement is not unveiled, we coated silicon wafers with Si-doped DLC(DLC-Si) films by direct-current plasma CVD process, evaluated their friction coefficient and wear depth, and investigated the cross-section profiles of the films. Ball-on-disk test revealed that the tribological properties improved most when silicon is added by 6-10 at.% against carbon in the DLC-Si films. X-ray reflectometry suggested the existence of a thin layer with a different scattering length density(SLD) on the surfaces of the DLC-Si films. The thickness of the layers is around 20nm. Neutron reflectivity measurements confirmed the formation similar SLD structure, the composition and mass density of the films. It is concluded that the surface thin layers, which are not observed for a DLC film free from or without silicon, should be responsible for the enhanced tribological properties.