Progress in Physics and Technology Developments for the Modification of JT-60

Recent progress in the physics and engineering design study for the modification programme of JT-60 is presented. In order to achieve a steady state high-β plasma operation, which is the dominant issue of this programme, physics design for the MHD control and the stability analysis is investigated. Engineering design and the R & D for the superconducting coils, irradiation shield are performed well towards the mission of programme.     

Preparation of large surface area nickel magnesium silicate and its catalytic activity for conversion of ethanol into buta-1,3-diene

The ternary oxide catalysts of nickel magnesium silicate with a large surface area (498–784m²/g) can be obtained by calcining a mixture of Ni(NO₃)₂, Mg(OH)₂ and SiO₂. The large surface area of the catalyst is attributed to its layer structure. The selectivity for buta-1,3-diene formation from ethanol on the catalysts was 90% or more and the yield of buta-1,3-diene was 53 mol%.     

Correlation analysis of principal components from two populations

We investigate a correlation coefficient of principal components from two sets of variables. Using perturbation expansion, we get a limiting distribution of the correlation. In addition, we obtain a limiting distribution of the Fisher's z transformation of the above correlation. Additionally, we verify the accuracy of the limiting distributions using Monte Carlo simulations. Finally in this study, we present two examples and a bootstrap estimation.     

Present status and performance of PACS at Kyoto University Hospital.

A pilot PACS project, named KIDS, has been running in Kyoto University Hospital. The purpose of the system is to establish a small PACS that includes all digital imaging modalities and to evaluate it. The project has been continued from the first phase (KIDS-1) to the second phase (KIDS-2). In the first phase, a small-scale PACS was developed. In the second phase, the expansion of coverage of modalities and completion of the image database was intended. At present, the database contains image data of 16264 patients amounting to 150 Gbytes. Simulation of the retrieval process to the database shows that 154.3 s per patient is required for retrieving his/her entire image data. This calculated value is close to the actual time.     

Another type of orthorhombic distortion in BaGd2Mn2O7 phase

A new type of orthorhombic phase was found in BaGd₂Mn₂O₇ by thermal cycling above and below the transition temperature, which is considered the true equilibrium phase. This distortion is usually typical of the orthorhombic phase in BaSm₂Mn₂O₇ or BaEu₂Mn₂O₇ compound.     

UNDO and REDO Operations for Solid Modeling

This article describes a method of representing a solid design procss using a tree structure. This representation supposrts UNDO and REDO operations for regenerating any solid in a previous stage of the design. The implementations of invertible set operations is also given in detail.     

Deactivation of Co---Mo/A12O3 hydrodesulfurization catalysts during a one-year commercial run

A series of Co---Mo catalysts with different Co and Mo loadings were prepared and exposed to a commercial HDS run for a year. From the activity tests using model compounds, the HDS activity of the fresh catalyst was found to increase up to 4.0 Mo atoms nm⁻² with increasing Co---Mo loading. However, no significant difference in the activity was observed in the used catalysts. TEM and EXAFS analyses revealed that the MOS₂ stacks aggregated in the lateral direction but did not grow in the normal direction to the layers during the run.     

Maternal and fetal mercury and n-3 polyunsaturated fatty acids as a risk and benefit of fish consumption to fetus

Maternal fish consumption brings both risks and benefits to the fetus from the standpoint of methylmercury (MeHg) and n-3 PUFA (polyunsaturated fatty acids). MeHg is one of the most risky substances to come through fish consumption, and mercury concentrations in red blood cells (RBC-Hg) are the best biomarker of MeHg exposure. Docosahexaenoic acid (DHA, C22:6n-3), which is one of the most important fatty acids for normal brain development and function, is also derived from fish consumption. Our objective in this study was to examine the relationships between RBC-Hg and plasma fatty acid composition in mother and fetus at parturition. Venous blood samples were collected from 63 pairs of mothers and fetuses (umbilical cord blood) at delivery. In all cases, fetal RBC-Hg levels were higher than maternal RBC-Hg levels. The geometric mean of fetal RBC-Hg was 13.4 ng/g, which was significantly (p < 0.01) higher than that of maternal RBC-Hg (8.41 ng/g). While the average fetal/maternal RBC-Hg ratio was 1.6, the individual ratios varied from 1.08 to 2.19, suggesting considerable individual differences in MeHg concentrations between maternal and fetal circulations at delivery. A significant correlation was observed between maternal and fetal DHA concentrations (r = 0.37, p < 0.01). Further, a significant correlation was observed between RBC-Hg and plasma DHA in fetus (r = 0.35, p < 0.01). These results confirm that both MeHg and DHA which originated from fish consumption transferred from maternal to fetal circulation and existed in the fetal circulation with a positive correlation. Pregnant women in particular need not give up eating fish to obtain such benefits. However, they would do well to at least consume smaller fish, which contain less MeHg, thereby balancing the risks and benefits from fish comsumption.     

Application of real-time confocal laser scanning microscopy to observe living cells in tissue specimens

Fluorescence microscopy imaging has developed into an important tool for the study of cell structure and function in cell biology. This non-invasive technique permits the characterization, localization and qualitative quantification of free ions, messengers, pH, voltage and other molecules in living cells. The regulation of cytosolic Ca2+ homeostasis is essential for cells. However, most investigations have used cultured or isolated cells as an experimental model and, consequently, provide only limited insight into the mechanisms that operate in tissue in situ. More useful information could be obtained by studying intact tissue specimens. The calcium dynamics of some tissue specimens, such as arteriole smooth muscle cells, supra cervical ganglia and peripheral nerve bundles, were analysed in this study. Real-time confocal microscopy revealed that individual cells exhibited different [Ca2+]i dynamics and the responses to transmitters/modulators were heterogeneous. It is important that the confocal microscopes have good detection performances, due to the reduction of stray light. We conclude that real-time confocal microscopy is a useful tool for investigating structural and functional changes of cells in living tissues, although suitable tissue-preparation is important for these measurements.