Superconductivity in undoped T' cuprates with Tc over 30 K

Undoped cuprates have long been considered to be antiferromagnetic insulators. In this article, however, we report that superconductivity is achieved in undoped T'-RE2CuO4 (RE = Pr, Nd, Sm, Eu, and Gd). Our discovery was performed by using metal-organic decomposition (MOD), an inexpensive and easy-to-implement thin-film process. The keys to prepare the superconducting films are firing with low partial-pressure of oxygen and reduction at low temperatures. The highest Tc of undoped T'-RE2CuO4 is over 30 K, substantially higher than "electron-doped" analogs. Remarkably, Gd2CuO4, even the derivatives of which have not shown superconductivity so far, gets superconducting with Tconset as high as ~ 20 K. The implication of our discovery is briefly discussed.Comment: 22 pages, 5 figures, submitted to Physical Review Letter

Ferromagnetism in a Hubbard model for an atomic quantum wire: a realization of flat-band magnetism from even-membered rings

We have examined a Hubbard model on a chain of squares, which was proposed by Yajima et al as a model of an atomic quantum wire As/Si(100), to show that the flat-band ferromagnetism according to a kind of Mielke-Tasaki mechanism should be realized for an appropriate band filling in such a non-frustrated lattice. Reflecting the fact that the flat band is not a bottom one, the ferromagnetism vanishes, rather than intensified, as the Hubbard U is increased. The exact diagonalization method is used to show that the critical value of U is in a realistic range. We also discussed the robustness of the magnetism against the degradation of the flatness of the band.Comment: misleading terms and expressions are corrected, 4 pages, RevTex, 5 figures in Postscript, to be published in Phys. Rev. B (rapid communication

A Clinical Evaluation of a Plastic Temporary Filling Material (Dura Seal®)

Recently Dura Seal, a kind of plastic, has been marketed as a temporary filling material. This clinical study was done to determine whether or not Dura Seal has the properties advertised by the manufacturer. A total of 135 teeth, including 110 vital teeth and 25 pulpless teeth, were prepared for metal inlay cavities. The prepared cavities were sealed with Dura Seal for an average of 12.0 days. Dura Seal was found to be easily removable, to show no pulp damage, and to have considerable mechanical strength

Mediterranean fever (MEFV) Variant P369S/R408Q in a Patient with Entero-Behcet\u27s Disease who Successfully Responded to Treatment with Colchicine

A 57-year-old Japanese woman who had been diagnosed as having entero-Behcet\u27s disease nine years earlier was admitted with a persistent high-grade fever. An Mediterranean fever (MEFV) gene analysis revealed the compound heterozygous P369S-R408Q variant. She was treated with colchicine, and her symptoms immediately improved. Prednisolone (PSL) was added to treat the punched-out ulcers in the terminal ileum, leading to remission. There has been no relapse since the PSL was discontinued. In Behcet\u27s disease patients with MEFV variants, the use of colchicine should therefore be considered in such patients as well as immunosuppressive therapy