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Abstract: Although the hippocampus is a brain region involved in short-term memory, the molecular mechanisms underlying memory formation are not completely understood. Here we show that sphingosine 1-phosphate (S1P) plays a pivotal role in the formation of memory. Addition of S1P to rat hippocampal slices increased the rate of AMPA receptor-mediated miniature excitatory postsynaptic currents (mEPSCs) recorded from the CA3 region of the hippocampus. In addition long-term potentiation (LTP) observed in the CA3 region was potently inhibited by a sphingosine kinase (SphK) inhibitor and this inhibition was fully reversed by S1P. LTP was impaired in hippocampal slices specifically in the CA3 region obtained from SphK1-knockout mice, which correlates well with the poor performance of these animals in the Morris water maze test. These results strongly suggest that SphK/S1P receptor signaling plays an important role in excitatory synaptic transmission in the CA3 region of hippocampus and has profound effects on hippocampal function such as spatial learning. [ABSTRACT FROM AUTHOR]

Abstract: We report scanning tunneling microscopy (STM) studies on the structural modulation-free in which Bi atoms are partially substituted by Pb atoms. Optimally doped sample with the superconducting transition temperature shows short atom-strings at a bias-voltage of 5mV. Some strings are bundled and aligned along the orthogonal oriented two Cu–O–Cu directions randomly. Atom-strings are also observed in the overdoped sample , while they are hardly seen in the heavily overdoped sample . It is found that the disturbance from overdoped holes reduces the number of atom-strings and obscures every atom-string. These results indicate that the plane possesses not only the two-dimensional electronic correlation caused by the two-dimensionality but also short-range one-dimensional one. [Copyright &y& Elsevier]

The vortex phase diagram of high-Tc superconductor YBa2Cu3Oy (YBCO) single crystals has been studied by resistivity and magnetization measurements in magnetic fields up to 30 T. The vortex matter in YBCO shows a complex and rich phase diagram being affected by small change of oxygen content. Furthermore, the low-temperature scanning tunneling microscopy of slightly overdoped YBCO crystals in magnetic fields up to 5 T has been performed. We find that the vortex image at 4.2 K and 1 T forms a distorted triangular pattern with a hexagonal symmetry, but at 5 T it shows a disordered pattern indicating the vortex glass phase. These results are consistent with the vortex phase diagram resulted from macroscopic properties. [Copyright &y& Elsevier]

Low-temperature scanning tunneling microscopy studies have been performed on YBa2Cu3O7−δ single crystals. We present two types of atomic images corresponding to BaO- and CuO-chain layers, which vary with applied bias voltage and temperature. At low bias voltage, the electronic modulation images of the CuO-chain layer tend to be emphasized. Warming the sample up to about 45 K alters the atomic images of the BaO layers but does not alter those of the CuO-chain layers. These results suggest that the electronic modulation images are closely related to the electronic states near the Fermi level and are attributed to the charge density wave. [Copyright &y& Elsevier]

Low-temperature scanning tunneling microscopy studies have been performed on YBa2Cu3O7−δ single crystals. We present two types of atomic images corresponding to BaO- and CuO-chain layers, which vary with applied bias voltage and temperature. At low bias voltage, the electronic modulation images of the CuO-chain layer tend to be emphasized. Warming the sample up to about 45 K alters the atomic images of the BaO layers but does not alter those of the CuO-chain layers. These results suggest that the electronic modulation images are closely related to the electronic states near the Fermi level and are attributed to the charge density wave. [ABSTRACT FROM AUTHOR]

Low-temperature scanning tunneling microscopy on the BaO layer of cold-cleaved YBa2(Cu1−xZnx)3O7−δ single crystals reveals the one-dimensional charge modulations at lower bias voltage. These charge modulations have various lengths and are distributed randomly in space. The spatially inhomogeneous electronic state is regarded to be induced by Zn impurities in the CuO2 plane just under the BaO layer, because there are no charge modulations on Zn-free samples. The one-dimensional character possibly reflects the interaction between the CuO2 and the CuO-chain layers. [Copyright &y& Elsevier]

We report the transport properties in the quantum vortex liquid (QVL) state of the layered organic superconductor κ-(BEDT-TTF)2Cu(NCS)2. A steep change of the resistivity in the vortex liquid state is observed below about 1 K. In the low resistance state at lower temperatures, finite resistivity persists at least down to 100 mK. The finite residual resistivity may result in QVL assisted by the strong quantum fluctuations. A non-ohmic behavior appears only in the low resistance state, but not in the thermal vortex liquid state at high temperatures. These transport properties are similar to the observations discussed as the vortex slush state in the high-Tc oxides. [Copyright &y& Elsevier]

Abstract: We have studied low-energy electronic structure of using high-resolution angle-resolved photoemission spectroscopy (ARPES). By carefully tuning photon energy and polarization of incident light, we identified five different bands in the vicinity of the Fermi level, those are surface-bilayer-derived bonding and antibonding bands, their bulk counterparts, and CuO-chain-derived band, respectively. The surface bands show metallic property reflecting highly overdoped character, while bulk bands show signature of a -wave superconducting gap opening. The present ARPES result suggests the universality of the bulk electronic states in bilayer high- superconductors. [Copyright &y& Elsevier]

Abstract: Introduction: Accurate pretransplant estimation of the recipient''s standard liver volume (SLV) is important. The purpose of this study was to compare reported formulas for clinical estimation of liver volume among Japanese adults. Methods: We reviewed data on 70 healthy adults (46 men, 24 women, ages 20 to 65 years old) evaluated for living donor liver transplantation. Liver volume (LV) was measured using two- or three-dimensional computed tomography volumetry (CTV). The formulas of DeLand (LV = 1020 × body surface area [BSA] − 220), Urata (LV = 706.2 × BSA + 2.4), Noda (LV = 50.12 × BW0.78), Heinemann (LV = 1072.8 × BSA − 345.7), Vauthey (LV = 18.51 × BW + 191.8) and Yoshizumi (LV = 772 × BSA) were applied to estimate LV. We calculated the differences for individual donors betwen CTV and LV estimated by each formula. Results: Mean LVs as estimated by the formulae of DeLand and Heinemann et al were significantly greater (P < .01) than the mean CTV, while LV estimated by the formula of Urata was significantly less (P < .05) than the CTV. The formulas of DeLand and Heinemann overestimated LV, while the formula of Urata underestimated it. The formulae of Noda et al and Yoshizumi et al tended to underestimate the LV when the CTV was greater than 1600 cm3. When the Yoshizumi formula was applied, the number of donors with an acceptable difference (±15%) between CTV and estimated LV was 55 (78.6%). Conclusions: The Yoshizumi formula was applicable, especially for patients with a BSA < 2.0, whereas the well-known Urata formula made LV underestimates. [Copyright &y& Elsevier]

BACKGROUND: Phase I/II clinical trials of S-1 plus cisplatin for advanced gastric cancer have yielded good responses and the treatment was well tolerated. In this S-1 Plus cisplatin versus S-1 In RCT In the Treatment for Stomach cancer (SPIRITS) trial, we aimed to verify that overall survival was better in patients with advanced gastric cancer treated with S-1 plus cisplatin than with S-1 alone. METHODS: In this phase III trial, chemotherapy-naive patients with advanced gastric cancer were enrolled between March 26, 2002, and Nov 30, 2004, at 38 centres in Japan, and randomly assigned to S-1 plus cisplatin or S-1 alone. In patients assigned to S-1 plus cisplatin, S-1 (40-60 mg depending on patient's body surface area) was given orally, twice daily for 3 consecutive weeks, and 60 mg/m(2) cisplatin was given intravenously on day 8, followed by a 2-week rest period, within a 5-week cycle. Those assigned to S-1 alone received the same dose of S-1 twice daily for 4 consecutive weeks, followed by a 2-week rest period, within a 6-week cycle. The primary endpoint was overall survival. Secondary endpoints were progression-free survival, proportions of responders, and safety. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00150670. FINDINGS: 305 patients were enrolled; seven patients were ineligible or withdrew consent, therefore, 148 patients were assigned to S-1 plus cisplatin and 150 patients were assigned to S-1 alone. Median overall survival was significantly longer in patients assigned to S-1 plus cisplatin (13.0 months [IQR 7.6-21.9]) than in those assigned to S-1 alone (11.0 months [5.6-19.8]; hazard ratio for death, 0.77; 95% CI 0.61-0.98; p=0.04). Progression-free survival was significantly longer in patients assigned to S-1 plus cisplatin than in those assigned to S-1 alone (median progression-free survival 6.0 months [3.3-12.9] vs 4.0 months [2.1-6.8]; p<0.0001). Additionally, of 87 patients assigned S-1 plus cisplatin who had target tumours, one patient had a complete response and 46 patients had partial responses, ie, a total of 54% (range 43-65). Of 106 patients assigned S-1 alone who had target tumours, one patient had a complete response and 32 had partial responses, ie, a total of 31% (23-41). We recorded more grade 3 or 4 adverse events including leucopenia, neutropenia, anaemia, nausea, and anorexia, in the group assigned to S-1 plus cisplatin than in the group assigned to S-1 alone. There were no treatment-related deaths in either group. INTERPRETATION: S-1 plus cisplatin holds promise of becoming a standard first-line treatment for patients with advanced gastric cancer. [ABSTRACT FROM AUTHOR]