We have studied brain tissues from three patients with corticobasal degeneration (CBD) histologically, ultrastructurally and immunohistochemically. Ballooned neurons in the cerebral cortex and severe degeneration of the substantia nigra were observed in them all and weakly basophilic neurofibrillary tangles (NFTs) were distributed widely in the basal ganglia and brain stem. Ultrastructural examination demonstrated that the NFTs comprised characteristic 15-nm-wide straight tubules, which showed positive immunohistochemical staining with an antibody against tau, but not ubiquitin. Tau-immunoreactive neuronal cell bodies without NFTs also were found in the cerebral cortex and subcortical nuclei, predominantly in the brain stem, and the greatest number of tau-positive glial inclusions occurred in the cerebral gray and white matter of the pre- and post-central gyri. These inclusions comprised tubular structures with diameters of about 15 nm and were localized in the oligodendroglial cellular cytoplasm and processes. These findings indicate that there is a close cytoskeletal pathological relationship between CBD and progressive supranuclear palsy.

As a novel scintillation material, the use of Ce-doped Gd 2 Si 2 O 7 was investigated. In fact, (Gd 0.9 Ce 0.1 ) 2 Si 2 O 7 powder showed about five-times greater light output than Gd 2 SiO 5 (GSO) powder samples for alpha-particles from 241 Am. Furthermore, a fast decay constant of 59 ns was obtained for alpha-particles from 241 Am. Relations between the Ce-concentration, crystal structure and luminescence characteristics were also elucidated. Results of these studies show that heavy Ce-doping alters the Gd 2 Si 2 O 7 crystal structure and that the luminescence intensity is dependent not on Ce-concentration but on the triclinic structure formed by heavy Ce-doping.

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Interaction cross sections for 42-51 Ca on a carbon target at 280 MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N = 28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness. A simple examination based on the Fermi-type distribution, and the Mean-Field calculations point out that this anomalous enhancement of the nuclear size beyond N = 28 results from an enlargement of the core by a sudden increase in the surface diffuseness of the neutron density distribution, which implies the swelling of the bare 48 Ca core in Ca isotopes beyond N = 28. PACS numbers: 25.60.Dz Systematic studies of nuclear radii along the isotopic chain have so far elucidated changes in the nuclear structure such as the emergence of a halo as well as the development of neutron skin and nuclear deformation [1][2][3][4][5]. Nuclear charge radii, which represent charge spreads in these nuclei, also give complemental information on the size of the nucleus. It has been revealed that the trend of charge radii along the isotopic chain shows a sudden increase, which is often called a "kink," just after the magic number [6]. In particular, the neutron magic number N = 28 has received considerable attention. Recently, unexpectedly large charge radii were observed in neutron-rich Ca isotopes beyond N = 28 [7]. This sudden growth in charge radii from 48 Ca (N = 28) to 52 Ca represents a challenging problem; it has not been quan-titatively explained by any theoretical calculations other than the Hartree-Fock-Bogolyubov calculation with the Fayans energy density functional [8]. This anomalous phenomenon observed in Ca isotopes is stimulating further studies of nuclear charge radii in a wide mass region [8][9][10][11][12].In contrast, information on the evolution of the size of the neutron density distribution has not been obtained across N = 28. For example, nucleon density distributions ρ m (r) or point-neutron density distributions ρ n (r) for Ca isotopes have been deduced only for stable nuclei, 40,42,44,48 Ca, through the hadron elastic scattering [13][14][15][16][17][18][19][20][21][22][23].The experimental data for root-mean-square (RMS) radii of ρ m (r) or ρ n (r) for Ca isotopes beyond N = 28

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Abstract. An isomeric state in the proton drip-line nucleus 26 P has been observed by the γ-ray spectroscopy. The γ-ray energy and the half-life are 164.4 ± 0.1 keV and 120 ± 9 ns, respectively. For the isomeric transition of the mirror nucleus 26 Na, the γ-ray energy of 82.40 ± 0.04 keV and the half-life of 4.35 ± 0.16 µs are also revised. Comparing the experimental reduced transition probabilities of 26 Na and 26 P with theoretical ones calculated by the shell model with the USDA interaction, the spin-parity (J π ) of the isomeric state in 26 P is most likely to be 1 + .