redox reactions in fuel cells and metaloxygen batteries as well as water-splitting devices. [1][2][3][4] Including the initial notable works in the 1980s, [5][6][7] many experimental and theoretical studies on the ABO 3 -type perovskite catalysts have dealt with the number of d-electrons of B-site cations, the bond strength of BOH, the position of the O 2p band center, the effect of oxygen vacancies, and the role of lattice oxygen redox in efforts to account for the crucial contributions that correlate with the high catalytic activity during the oxygen evolution reaction (OER). [6][7][8][9][10][11][12] By extensive comparison of more than ten perovskite oxides, recent studies also suggested activity descriptors on the basis of the number of e g -orbital electrons of the 3d transition metals [13] and the charge transfer energy between metal and oxygen electrons [14] to understand the OER activity differences among the perovskite family. Although various structural and electronic factors should be taken into account to precisely depict the catalytic behavior of perovskites [15][16][17] and other transitionmetal oxides, [18][19][20][21][22][23] it appears to be accepted in general that relative difference of energy level between the 3d orbitals of B-site cations and the 2p orbitals of oxygen anions play an important role in significant promotion of charge transfer between [BO 6 ] at the surface and adsorbates, resulting in much higher OER efficiency at a lower overpotential. [9,[11][12][13][14][24][25][26][27][28] In stark contrast to the [BO 6 ] octahedra in the bulk, most [BO 6 ] units at grain boundaries (GBs) in polycrystals have severely distorted geometric configurations of B and O. [29,30] Note that the atomic displacement from this distortion at GBs is usually much greater than the displacement that occurs at the crystal surface for relaxation [31] and/or is induced by the coherent strain via using the epitaxial thin-film growth. [26,32] As a result, it can be reasonably anticipated that the electronic states of transition-metal 3d and oxygen 2p orbitals at GBs considerably differ from those in the bulk. In this regard, a combination of selective analysis of the OER characteristics at GBs and observation of the grain-boundary atomic structure can provide direct and insightful information that has not been offered in previous studies to elucidate the correlation between A grain boundary forms as an internal interface when two crystalline grains with mutually different crystallographic orientations are in direct contact with each other. As a result, atomic arrangement at grain boundaries differs from that of the bulk, showing serious displacements deviating from the original symmetric positions. As these symmetry-broken configurations are difficult to achieve in the bulk crystals, grain boundaries are considered distinctive platforms that can exhibit new physical properties. By using both sintered polycrystals with various grain sizes and thin films on bicrystal substrates, it is directly verified that surfac...

Pure epidural cavernous hemangioma of the spine without vertebral involvement is rare. Due to the slow growth of this lesion, the most common symptoms are chronic pain, myelopathy, and radiculopathy. In our case, the patient complained of an acute onset sensory deficit of the C4 dermatome. An MRI revealed an epidural mass with an acute hematoma. Here, we report a case of a pure epidural cavernous hemangioma that presented with acute neurologic symptoms caused by intralesional hemorrhage and an acute epidural hematoma, which were demonstrated on the patient's MRI.

SummaryAlthough chemotherapy remains among the best treatment options for most cancers, adjuvant therapies such as dendritic cell (DC)-based immunotherapy have been added to treatment protocols to destroy residual tumour cells. Combination treatment with low-dose temozolomide (TMZ) chemotherapy followed by vaccination with TAT-survivin-pulsed DCs enhanced T-cell responses specific for survivin and improved survival rate, as compared with DC alone or TMZ alone. Moreover, antigen-specific immunity appears to be mediated by CD8 + T cells, as determined by in vitro T-cell subset depletion. These studies demonstrated that a combination of low-dose TMZ chemotherapy and TAT-based DC immunotherapy may be a novel strategy for safe and effective treatment of malignant gliomas.

In many ion-conducting polycrystalline oxides, grain boundaries are generally accepted as rate-limiting obstacles to rapid ionic diffusion, often resulting in overall sluggish transport. Consequently, based on a precise understanding of the structural and compositional features at grain boundaries, systematic control of the polycrystalline microstructure is a key factor to achieve better ionic conduction performance. In this study, we clarify that a nanometer-thick amorphous phase at most grain boundaries in proton-conducting BaCeO polycrystals is responsible for substantial retardation of proton migration and moreover is very reactive with water and carbon dioxide gas. By a combination of atomic-scale chemical analysis and physical imaging, we demonstrate that highly densified BaCeO polycrystals free of a grain-boundary amorphous phase can be easily fabricated by a conventional ceramic process and show sufficiently high proton conductivity together with significantly improved chemical stability. These findings emphasize the value of direct identification of intergranular phases and subsequent manipulation of their distribution in ion-conducting oxide polycrystals.

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