The electronic structure of heavy-fermion compounds arises from the interaction of nearly localized 4f- or 5f-shell electrons (with atomic magnetic moments) with the free-electron-like itinerant conduction-band electrons. In actinide or rare-earth heavy-fermion materials, this interaction yields itinerant electrons having an effective mass about 100 times (or more) the bare electron mass. Moreover, the itinerant electrons in UPd2Al3 are found to be superconducting well below the magnetic ordering temperature of this compound, whereas magnetism generally suppresses superconductivity in conventional metals. Here we report the detection of a dispersive excitation of the ordered f-electron moments, which shows a strong interaction with the heavy superconducting electrons. This 'magnetic exciton' is a localized excitation which moves through the lattice as a result of exchange forces between the magnetic moments. By combining this observation with previous tunnelling measurements on this material, we argue that these magnetic excitons may produce effective interactions between the itinerant electrons, and so be responsible for superconductivity in a manner analogous to the role played by phonons in conventional superconductors.

Secreted frizzled related protein 1 (SFRP1) is an antagonist of the transmembrane frizzled receptor, a component of the Wnt signaling pathway, and has been suggested to be a candidate tumor suppressor in several human malignancies. Since SFRP1 is located at chromosome 8p11, where lung cancers also exhibit frequent allelic loss, we hypothesized that the inactivation of SFRP1 is also involved in lung carcinogenesis. To substantiate this, we performed mutational analysis of SFRP1 for 29 nonsmall-cell lung cancer (NSCLC) and 25 small-cell lung cancer (SCLC) cell lines, and expression analysis for the same cell lines. Although somatic mutations were not detected in the coding sequence, downregulation of SFRP1 was observed in 14 (48%) NSCLC and nine (36%) SCLC cell lines. We analysed epigenetic alteration of the SFRP1 promoter region and detected hypermethylation in 15 (52%) of 29 NSCLC cell lines, two (8%) of 25 SCLC cell lines, and 44 (55%) of 80 primary lung tumors. By comparing the methylation status with SFRP1 expression, we found a significant correlation between them. We also performed loss of heterozygosity (LOH) analysis and found that 15 (38%) of 40 informative surgical specimens had LOH in the SFRP1 gene locus. Furthermore, we performed colony formation assay of two NSCLC cell lines (NCI-H460 and NCI-H2009) and found the reduction of colony formation with SFRP1 transfection. In addition, we also detected that SFRP1 inhibits the transcriptional activity of b-catenin, which is thought to be a downstream molecule of SFRP1, with luciferase reporter assay. Our current studies demonstrated that the SFRP1 gene is frequently downregulated by promoter hypermethylation and suppresses tumor growth activity of lung cancer cells, which suggests that SFRP1 is a candidate tumor suppressor gene for lung cancer.Oncogene (

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We report (27)Al Knight shift ( (27)K) measurement on a single-crystal UNi(2)Al(3) that reveals a coexistence of superconductivity and a spin-density-wave (SDW) type of magnetic ordering ( T(SDW) = 4.5 K). The spin part of (27)K, (27)K(s), does not change down to 50 mK across the superconducting (SC) transition temperature T(c) approximately 0.9 K. In contrast with the isostructural compound UPd(2)Al(3) ( T(c) approximately 2 K), which was identified to be a spin-singlet d-wave superconductor, the behavior of (27)K strongly supports that UNi(2)Al(3) , like UPt(3) and Sr(2)RuO(4), belongs to a class of spin-triplet SC pairing state superconductors.