Exciton localization of single-walled carbon nanotubes revealed by femtosecond excitation correlation spectroscopy

Photoluminescence (PL) dynamics in single-walled carbon nanotubes (SWNTs) has been studied by the femtosecond excitation correlation method with a 150 fs time resolution. The SWNT samples were synthesized by different methods and suspended in gelatin films or D2O solutions. The PL dynamics of SWNTs depends on the local environment surrounding the SWNTs rather than the synthesis methods. The very weak temperature dependence of PL and the environment-dependent PL reveal that the PL relaxation process is dominated by the interplay between free excitons and weakly localized excitons

Spin-orbit coupling inactivity of Co2+^{2+} ion in geometrically frustrated magnet GeCo2_2O4_4

We report single-crystal neutron diffraction studies on a spinel antiferromagnet GeCo$_2$O$_4$, which exhibits magnetic order with a trigonal propagation vector and tetragonal lattice expansion ($c/a\simeq1.001$) below $T_{\rm N}=21$ K. For this inconsistency between spin and lattice in symmetry, magnetic Bragg reflections with a tetragonal propagation vector were discovered below $T_{\rm N}$. We discuss spin and orbital states of Co$^{2+}$ ion underlying the new magnetic component.Comment: 3 pages 2 figures, submitted to ICFCM proceeding (Journal of Physics: Conference Series, 2011

Granular Cell Myoblastoma, an Electron-Microscopic and Histochemical Study

A case of granular cell myoblastoma was studied histochemically and electron microscopically. The authors\u27 opinion on the pathogenesis of this tumor was described after the review of literature

Presynaptically Released Cbln1 Induces Dynamic Axonal Structural Changes by Interacting with GluD2 during Cerebellar Synapse Formation

SummaryDifferentiation of pre- and postsynaptic sites is coordinated by reciprocal interaction across synaptic clefts. At parallel fiber (PF)-Purkinje cell (PC) synapses, dendritic spines are autonomously formed without PF influence. However, little is known about how presynaptic structural changes are induced and how they lead to differentiation of mature synapses. Here, we show that Cbln1 released from PFs induces dynamic structural changes in PFs by a mechanism that depends on postsynaptic glutamate receptor delta2 (GluD2) and presynaptic neurexin (Nrx). Time-lapse imaging in organotypic culture and ultrastructural analyses in vivo revealed that Nrx-Cbln1-GluD2 signaling induces PF protrusions that often formed circular structures and encapsulated PC spines. Such structural changes in PFs were associated with the accumulation of synaptic vesicles and GluD2, leading to formation of mature synapses. Thus, PF protrusions triggered by Nrx-Cbln1-GluD2 signaling may promote bidirectional maturation of PF-PC synapses by a positive feedback mechanism

The Level and Stability of Residual Catalase in Cultured Acatalasemic Skin Fibroblasts

In an attempt to determine the level and heat stability of residual catalase in somatic cells of acatalasemic Japanese, skin fibroblasts from an acatalasemic subject were cultured, and the catalase activity of the cultured fibroblasts was compared with that of cultured normal fibroblasts. Catalase activity was determined using an oxygen electrode. The residual catalase activity in cultured acatalasemic fibroblasts was 10% of the normal. The heat stability at 55 degrees C of residual catalase in the acatalasemic fibroblasts was similar to that of normal fibroblasts

Numerical analysis of re-oscillation and non-centrosymmetric convection in a porous enclosure due to opposing heat and mass fluxes on the vertical walls

金沢大学環日本海域環境研究センターエコテクノロジー研究部門Two peculiar convection patterns-re-oscillation and stable non-centrosymmetric convection-are observed when two-dimensional double-diffusive convection in a porous enclosure (aspect ratio = 1.5) is analysed numerically. The top and bottom walls of the enclosure are insulated; constant and opposing heat and mass fluxes are prescribed on the vertical walls. Re-oscillation occurs when the convection pattern changes from centrosymmetric to non-centrosymmetric. When the buoyancy ratio, which generates re-oscillation convection, is marginally lower, the convection pattern changes to stable non-centrosymmetric. These two convection patterns can be observed only for limited values of the Rayleigh number, Lewis number, and buoyancy ratio. © 2009 Elsevier Ltd. All rights reserved