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115In-NMR measurements of the unconventional superconductor CeCoIn $$_5$$ reveal an unusual temperature dependence of the Knight shift near the upper limit of $$H_{c2}$$ . From a simulation analysis, the present NMR study provides a direct evidence at a microscopic point of view that the Fulde–Ferrell–Larkin–Ovchinikov (FFLO) state is realized at the high field SC phase in CeCoIn $$_5$$ .

Fluoranthene (FA) forms a 1:1 van der Waals complex with benzene in cyclohexane. The 1H NMR spectrum of this complex shows that the FA moiety in the complex state has five kinds of hydrogen atoms and that the 1H NMR peaks assigned to the protons attached to the naphthalene skeleton are largely shifted to higher magnetic field on complex formation with benzene. These observations indicate that the complex takes the structure of CS symmetry, in which the benzene molecule mainly interacts with the π electronic system localized on the naphthalene moiety of FA. The present ab initio calculations reproduce well the 1H NMR spectral shifts mentioned above and the experimentally predicted CS structure of the complex. According to the PPP calculations for the electronic absorption spectral changes on the complex formation, the FA-benzene complex is considered to take a sandwich type structure.

By using spatially-resolved NMR method, we observed nuclear spin-lattice relaxation rate (1/T1) of the vortex state to probe antiferromagnetic correlations at the vortex core. We found that the temperature dependence of 1/T1 shows a peak, which results from a local antiferromagnetic ordering of Cu spins in the vortex core.

The electronic absorption and X-ray photoelectron spectra of N,N′-disalicylidenetrimethylenediaminatocopper(II) ([Cu(saltn)]) and N,N′-disalicylidene-trans-1,2-cyclohexanediaminatocopper(II) ([Cu(salchx)]) were measured. From these results and from informations derived from MO calculations the electronic structure of the complexes was clarified. Each electronic absorption band which can be assigned to the ππast; or ML/LMCT transition of [Cu(saltn)] or [Cu(salchx)] observed in the wavelength region of 450–200 nm appears at the almost same frequency as the corresponding band of N,N′-disalicylideneethylenediaminatocopper(II) ([Cu(salen)]) in solution. The LLCT bands (the intramolecular CT band between two π-electronic systems separated by saturated hydrocarbon chains such as ) also appear at nearly the same positions (ca. 245 nm) for [Cu(salchx)], [Cu(saltn)], and [Cu(salen)]. The locations of the dd transition and the intensity of the ML/LMCT transition of [Cu(saltn)] are significantly different from those of [Cu(salen)] and [Cu(salchx)]. These differences may arise from the strengths of the interaction between metal and ligand.

Hole-doping effects are investigated by Cu-NMR for single crystal of Sr{sub 14{minus}x}Ca{sub x}Cu{sub 24}O{sub 41}. The charge order of Cu{sup 2+} and Cu{sup 3+} and spin dimer ground state in the chain of Sr{sub 14}Cu{sub 24}O{sub 41} are proved by NMR study. The magnetic order of Cu spins in the chain and also the field-induced staggered moments at the ladder Cu site are confirmed for 3 {le} x {le} 6 of Sr{sub 14{minus}x}La{sub x}Cu{sub 24}O{sub 41}.

We study the microwave response perpendicular to the superconducting layers of high temperature superconductors in a wide range of temperatures and fields. A novel microwave response,i.e. Josephson plasma resonance, shows up in the superconducting state of Bi2Sr2CaCu2O8+δ. This resonance enable us to measure the magnitude of interlayer phase coherence quantitatively. Josephson plasmon is shown to interact strongly with the vortices. Therefore it provides a new powerful tool to probe the vortex state. The vortex state of high temperature superconductors is discussed in the light of the interlayer phase coherence.

The muon spin rotation (μ +SR) and NMR measurements provides clear evidences of the antiferromagnetic order of Cu-moment below 35 K for La2−x Ba x CuO4 and below 15 K for La2−x Sr x CuO4 in the narrow range ofx where the high-T c superconductivity (SC) is suppressed remarkably. The results suggest that the freezing of spin fluctuations of Cu-moment is relevant to the local suppression of SC under an change of the electronic state coupled with the lattice instability.

Zero field positive muon spin rotation method (μ +SR) is applied on La2−x Sr x CuO4 around forx=0.12 at which the high-T c superconductivity (SC) is suppressed. The magnetically ordered state of Cu-moments, which is not a spin glass state but an antiferromagnetic like state, appears below 15 K for 0.105≤x≤0.120. The magnetic phase boundary is very similar to the one of the La2−x Ba x CuO4 in which the structural transition from the low temperature orthorhombic (LTO) phase to the low temperature tetragonal (LTT) phase is observed aroundx=0.12. The present study suggests that there is no big difference of the electronic state of the CuO2 plane between the La-Ba system and the La-Sr system and that the magnetic ordering of Cu-moments plays an important role for the suppression of the high-T c SC aroundx=0.12 in both of the systems, although the LTO-LTT structural transition has not been observed yet in the La-Sr system.

Muon spin rotation (μ+SR) measurement provides clear evidence of the antiferromagnetic order of Cu moments below 35 K for La2−xBaxCuO4 and below 15 K for La2−xSrxCuO4 in the narrow range ofx where the high-Tc superconductivity (SC) is suppressed remarkably. The results suggest that the change of the electronic state coupled with the lattice instability is relevant to the local suppression of SC and freezing of spin fluctuations of the Cu moment.

Muon spin rotation (μSR) is applied to La2−xBa x CuO4 aroundx=0.12 where the superconductivity (SC) is suppressed remarkably. The magnetic ordering of Cu-moments appears below 35 K in the narrow range ofx where a lattice instability from the low temperature orthorhombic (LTO) to the low-temperature tetragonal (LTT) structure exists. The present study suggests strongly that the magnetic ordering of Cu-moments is an important factor in the suppression of high-Tc superconductivity aroundx=0.12 in La2−xBa x CuO4. Similar results are obtained for the La2−xSr x CuO4 and La2−x−ySr x Nd y CuO4 systems.

Background The epidermal growth factor (EGF) and EGF receptor (EGFR) families play important roles in the hyperplastic growth of several tissues as well as tumor growth. Since synovial hyperplasia in rheumatoid arthritis (RA) resembles a tumor, involvement of the EGF/EGFR families in RA pathology has been implied. Although several reports have suggested that ErbB2 is the most important member of the EGFR family for the synovitis in RA, it remains unclear which members of the EGF family are involved. To clarify the EGF-like growth factors involved in the pathology of RA, we investigated the expression levels of seven major EGF-like growth factors in RA patients compared with those in osteoarthritis (OA) patients and healthy control subjects. Methods The expression levels of seven EGF-like growth factors and four EGFR-like receptors were measured in mononuclear cells isolated from bone marrow and venous blood, as well as in synovial tissues, using quantitative RT-PCR. Further evidence of gene expression was obtained by ELISAs. The proinflammatory roles were assessed by the growth-promoting and cytokine-inducing effects of the corresponding recombinant proteins on cultured fibroblast-like synoviocytes (FLS). Results Among the seven EGF-like ligands examined, only amphiregulin (AREG) was expressed at higher levels in all three RA tissues tested compared with the levels in OA tissues. The AREG protein concentration in RA synovial fluid was also higher than that in OA synovial fluid. Furthermore, recombinant human AREG stimulated FLS to proliferate and produce several proinflammatory cytokines, including angiogenic cytokines such as interleukin-8 and vascular endothelial growth factor (VEGF), in a dose-dependent manner. The VEGF mRNA levels in RA synovia and VEGF protein concentrations in RA synovial fluid were significantly higher than those in the corresponding OA samples and highly correlated with the levels of AREG. Conclusion The present findings suggest that AREG functions to stimulate synovial cells and that elevated levels of AREG may be involved in the pathogenesis of RA.

We have carried out31P-nuclear magnetic resonance (NMR) to investigate low energy spin excitations in both spin ladder. (VO)2P2O7 and spin dimer VO(HPO4)0.5H2O systems. Temperature (7) dependences of NMR shift,K and nuclear spin-lattice relaxation time,T1 in the both compounds show a thermal activation-type behavior originating from spin gap formations in the spin excitation. The most distinct difference appears in theT-dependence of (T1TK)−1, namely, theT-independent behavior in the dimer system, but the large decrease below the order of the spin gap in the ladder system. These experimental results suggest that a spin gap Δ is independent of wave vectorq in dynamical susceptibilityχ(q, ω) for the dimer system, while Δ depends onq inχ(q, ω) for the ladder system.

We have measured the Hall effect in the vortex state of La2−x Sr x CuO4 single-crystal thin films from the underdoped to the overdoped regime (x=0.1–0.24). A sign change of the Hall effect is found belowT c in the underdoped and slightly overdoped samples, while it is absent in the overdoped samples. This result is consistent with the theoretical prediction based on the time-dependent Ginzburg-Landau equation, which suggests that the sign reversal is related to the electronic state at the Fermi level.

Overdoped (Y1−xCax)Ba2Cu3O7−δ system has been investigated by NQR measurement. With hole doping, Tc drops down to 47K in x=0.2 and the υQ of Cu in CuO2 plane increases.63(1/T1T) for x=0.2 is T-independent in the wide-T range of 50–100K, which is a contrast to “spin-gap” like-behavior in the lightdoped cuprates.