73 research outputs found

    Superconducting mechanism for the cuprate Ba2_2CuO3+δ_{3+\delta} based on a multiorbital Lieb lattice model

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    For the recently discovered cuprate superconductor Ba2CuO3+δ\mathrm{Ba_{2}CuO_{3+\delta}}, we propose a lattice structure which resembles the model considered by Lieb to represent the vastly oxygen-deficient material. We first investigate the stability of the Lieb-lattice structure, and then construct a multiorbital Hubbard model based on first-principles calculation. By applying the fluctuation-exchange approximation to the model and solving the linearized Eliashberg equation, we show that ss-wave and dd-wave pairings closely compete with each other, and, more interestingly, that the intra-orbital and inter-orbital pairings coexist. We further show that, if the energy of the d3z2−r2d_{3z^2-r^2} band is raised to make it "incipient" with the lower edge of the band close to the Fermi level within a realistic band filling regime, s±s\pm-wave superconductivity is strongly enhanced. We reveal an intriguing relation between the Lieb model and the two-orbital model for the usual K2_2NiF4_4 structure where a close competition between s−s- and d−d-wave pairings is known to occur. The enhanced superconductivity in the present model is further shown to be related to an enhancement found previously in the bilayer Hubbard model with an incipient band.Comment: 19 pages, 20 figures; references and figures update

    Tumor Shrinkage in Response to Vitamin K2 in Hepatocellular Carcinoma with Multiple Lung Metastases: A Case Report

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    Introduction: Advanced or metastatic hepatocellular carcinoma (HCC) can be lethal because of the limited therapeutic approach such as sorafenib. Recently, Vitamin K2 (VK2) has been increasingly recognized to have anti-cancer effects for HCC in vitro and vivo. However, the direct anti-cancer effect of VK2 to HCC has not been established yet in human.Presentation of Case: We presented here a 88-year-HCC patient displayed a tumor shrinkage in response to VK2 in multiple lung metastases, indicating the possibility of VK2 as an anti-cancer agent in human. Menatetrenone, a VK2 analogue, was introduced for multiple lung metastases as a palliative treatment, and thereafter multiple lung metastases, except one lung lesion, displayed tumor shrinkage and disappeared within five months after VK2 intake. The residual one lesion continued to grow up during the intake of VK2, suggesting that the residual tumor was insensitive to VK2 represented by tumor heterogeneity. Consequently, after a radiation therapy for the residual lesion, the elevated tumor markers of all were finally decreased into normal levels, and he is still alive for 18 months after VK2 intake without elevated tumor marker levels and toxic adverse effects.Conclusion:VK2 may be a therapeutic option for advanced and metastatic HCCs without any toxic adverse

    The Impact of Tofogliflozin on Physiological and Hormonal Function, Serum Electrolytes, and Cardiac Diastolic Function in Elderly Japanese Patients with Type 2 Diabetes Mellitus

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    The sodium glucose transporter 2 (SGLT2) inhibitor tofogliflozin is a glucose-lowering drug that causes the excretion of surplus glucose by inhibiting SGLT2. Because of tofogliflozin’s osmotic diuresis mechanism, patients’ serum electrolytes, body fluid levels, and cardiac function must be monitored. We retrospectively analyzed the cases of 64 elderly Japanese patients with type 2 diabetes mellitus (T2DM) who received tofogliflozin for 3 months. Their HbA1c, serum electrolytes (sodium, potassium, chloride), hematocrit, brain natriuretic peptide (cardiac volume load marker) and renin and aldosterone (RAA; an index of regulatory hormones involved in body fluid retention) were continuously monitored during the investigation period. Renal function and cardiac function (by echocardiography) were assessed throughout the period. HbA1c significantly decreased (β1=−0.341, p<0.0001, linear regression analysis [LRA]). Most of the hormonal, electrolyte, and physiological parameters were maintained throughout the study period. In these circumstances, E/e’ tended to decrease (β1=−0.382, p=0.13, LRA). Compared to the baseline, E/e’ was significantly decreased at 1 and 3 months (p<0.01, p<0.05). In the higher E/e’ group (E/e’≥10, n=34), E/e’ decreased significantly (β1=−0.63, p<0.05, LRA). ΔE/e’ was correlated with body-weight change during treatment (r=0.64, p<0.01). The 3-month tofogliflozin treatment improved glycemic control and diastolic function represented by E/e’ in T2DM patients, without affecting serum electrolytes, renal function, or RAA. No negative impacts on the patients were observed. Three-month tofogliflozin treatment lowered glucose and improved cardiac diastolic function
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