188 research outputs found

    Microscopic approach to large-amplitude deformation dynamics with local QRPA inertial masses

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    We have developed a new method for determining microscopically the fivedimensional quadrupole collective Hamiltonian, on the basis of the adiabatic self-consistent collective coordinate method. This method consists of the constrained Hartree-Fock-Bogoliubov (HFB) equation and the local QRPA (LQRPA) equations, which are an extension of the usual QRPA (quasiparticle random phase approximation) to non-HFB-equilibrium points, on top of the CHFB states. One of the advantages of our method is that the inertial functions calculated with this method contain the contributions of the time-odd components of the mean field, which are ignored in the widely-used cranking formula. We illustrate usefulness of our method by applying to oblate-prolate shape coexistence in 72Kr and shape phase transition in neutron-rich Cr isotopes around N=40.Comment: 6pages, talk given at Rutherford Centennial Conference on Nuclear Physics, 8 - 12 August 2011, The University of Mancheste

    Effects of Metal Ion Addition on the Crystalline Phase of Zirconium Dioxide Studied by X-Ray Diffraction Spectrometry

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     ジルコニア担持酸化タングステン触媒の強酸性発現機構を解明するための予備検討として,水酸化ジルコニウムが873 -1073 K で焼成後に準安定正方晶を取り得る条件を探索するため,12 種類の金属イオンおよび硫酸イオンを添加した試料を調製し,結晶相の存在比率および格子面間隔をXRDにて検討した.種々のイオンを添加することでジルコニア結晶相の準安定正方晶を形成しうる温度領域が広がり,またその程度は添加金属種により異なった.水酸化ジルコニウムに金属イオンを添加した場合,準安定正方晶が存在しうる焼成温度範囲が狭い元素群のみ,773 K で焼成した際に観察される正方晶(101)面の格子面間隔が小さく,またそのイオン半径がジルコニウムイオンと近かった. Twelve kinds of metal-ion added zirconium oxide catalyst materials were prepared by impregnation of 10 mol% metal salt (Ca, V, Cr, Fe, Ni, Cu, Zn, Mo, W, Y and Ce) or sulfate ion onto amorphous zirconium hydroxide followed by calcination at 673-1273 K. Crystallization process of zirconium oxide, fraction of the tetragonal phase and d-spacing of the tetragonal (101) reflection were investigated by XRD as a function of calcination temperature. The addition of metal ion stabilized meta-stable tetragonal and/or cubic phase, and suppressed phase transition to thermodynamically stable monoclinic phase. The added elements were classified into four groups by degree of stabilization. In cases for Fe, Ni, Cu and Zn-ion added zirconium oxides, the meta-stable phase could exist at the calcination temperature till 873 K. The d (101) spacing for corresponding to tetragonal ZrO2 phase in the four samples calcined at 773 K were smaller than that for non modified ZrO2, and ion radii of the added elements were close to that of Zr4+

    GIPC-phospholipase D in plants

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    Previously, we detected an unknown sphingophospholipid in cabbage leaves and identified it as phytoceramide-1-phosphate (PC1P). We also found an enzyme activity that produces PC1P by glycosylinositol phosphoceramide (GIPC)-specific hydrolysis in cabbage leaves. To characterize the GIPC-specific phospholipase D (GIPC-PLD) activity, we investigated distributions of GIPC-PLD activity in 25 tissues of 10 plants. In most plants, the GIPC-PLD activity was the highest in roots. Young leaves of cabbage and Welsh onion had higher activities than corresponding aged outer leaves. The GIPC-PLD activities in leaves, stems and roots of mung bean were higher in the sprouting stage than in more mature stages. We also examined distribution of substrate GIPC and product PC1P, and found that GIPC was ubiquitously distributed at 50-280 nmol/g (wet wt) in tissues of plants, whereas PC1P was detectable (3-60 nmol/g wet wt.) only in tissues showing considerable GIPC-PLD activity. These results suggest a possibility that GIPC-PLD activity is involved in plant growth

    A study on ensuring the quality and safety of pharmaceuticals and medical devices derived from processing of autologous human induced pluripotent stem(-like) cells

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    As a series of endeavors to establish suitable measures for the sound development of regenerative medicine using human stem cell-based products, we studied scientific principles, concepts, and basic technical elements to ensure the quality and safety of therapeutic products derived from autologous human iPS cells or iPS cell-like cells, taking into consideration scientific and technological advances, ethics, regulatory rationale, and international trends in human stem cell-derived products. This led to the development of the Japanese official Notification No. 0907-4, “Guideline on Ensuring the Quality and Safety of Pharmaceuticals and Medical Devices Derived from the Processing of Autologous Human Induced Pluripotent Stem(-Like) Cells, ” issued by Pharmaceuticals and Food Safety Bureau, Ministry of Health, Labour and Welfare of Japan, on September 7, 2012. The present paper addresses various aspects of products derived from autologous human iPS cells (or iPS cell-like cells), in addition to similar points to consider that are described previously for autologous human stem cell-based products. Major additional points include (1) possible existence of autologous human iPS cell-like cells that are different from iPS cells in terms of specific biological features; (2) the use of autologous human iPS(-like) cells as appropriate starting materials for regenerative medicine, where necessary and significant; (3) establishment of autologous human iPS(-like) cell lines and their characterization; (4) cell banking and/or possible establishment of intermediate cell lines derived from autologous human iPS(-like) cells at appropriate stage(s) of a manufacturing process, if necessary; and (5) concerns about the presence of undifferentiated cells in the final product; such cells may cause ectopic tissue formation and/or tumorigenesis. The ultimate goal of this guidance is to provide suitable medical opportunities as soon as possible to the patients with severe diseases that are difficult to treat with conventional modalities
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