Pressure Study of BiS2-Based Superconductors Bi4O4S3 and La(O,F)BiS2

We report the electrical resistivity measurements under pressure for the recently discovered BiS2-based layered superconductors Bi4O4S3 and La(O,F)BiS2. In Bi4O4S3, the transition temperature Tc decreases monotonically without a distinct change in the metallic behavior in the normal state. In La(O,F)BiS2, on the other hand, Tc initially increases with increasing pressure and then decreases above ? 1 GPa. The semiconducting behavior in the normal state is suppressed markedly and monotonically, whereas the evolution of Tc is nonlinear. The strong suppression of the semiconducting behavior without doping in La(O,F)BiS2 suggests that the Fermi surface is located in the vicinity of some instability. In the present study, we elucidate that the superconductivity in the BiS2 layer favors the Fermi surface at the boundary between the semiconducting and metallic behaviors.Comment: 4 pages, 6 figures, Accepted for publication in J. Phys. Soc. Jp

Role of the Ce valence in the coexistence of superconductivity and ferromagnetism of CeO1−x_{1-x}Fx_{x}BiS2_{2} revealed by Ce L3L_3-edge x-ray absorption spectroscopy

We have performed Ce $L_3$-edge x-ray absorption spectroscopy (XAS) measurements on CeO$_{1-x}$F$_x$BiS$_2$, in which the superconductivity of the BiS$_2$ layer and the ferromagnetism of the CeO$_{1-x}$F$_x$ layer are induced by the F-doping, in order to investigate the impact of the F-doping on the local electronic and lattice structures. The Ce $L_3$-edge XAS spectrum of CeOBiS$_2$ exhibits coexistence of $4f^1$ (Ce$^{3+}$) and $4f^0$ (Ce$^{4+}$) state transitions revealing Ce mixed valency in this system. The spectral weight of the $4f^0$ state decreases with the F-doping and completely disappears for $x>0.4$ where the system shows the superconductivity and the ferromagnetism. The results suggest that suppression of Ce-S-Bi coupling channel by the F-doping appears to drive the system from the valence fluctuation regime to the Kondo-like regime, leading to the coexistence of the superconducting BiS$_2$ layer and the ferromagnetic CeO$_{1-x}$F$_x$ layer.Comment: 5 pages, 5 figure

Serum interleukin-6 response after spinal surgery:estimation of surgical magnitude

取得学位 : 博士（医学）, 学位授与番号 : 医博乙第1631号 , 学位授与年月日 : 平成19年4月18日, 学位授与大学 : 金沢大学, 主査教授 : 山本 健, 副査教授 : 向田 直史 , 濵田 潤一郎

Surgical site infection in spinal metastasis: risk factors and countermeasures.

金沢大学附属病院整形外科STUDY DESIGN: A retrospective review (phase 1) and prospective clinical study (phase 2). OBJECTIVES: To identify independent risk factors for surgical site infection (SSI) and to evaluate the positive effect of prostaglandin E1 (PGE1) to decrease the risk of SSI in patients with spinal metastasis. SUMMARY OF BACKGROUND DATA: Surgery for spinal metastasis is associated with an increased risk of SSI. Although previous reports have evaluated risk factors of SSI for spinal metastasis, most of the studies lack multivariate analysis. A recent study demonstrated the utility of PGE1 in decreasing wound complications in patients with prior irradiation. The role of PGE1 in surgery for spinal metastasis has not been previously evaluated. METHODS: One hundred ten patients with spinal metastasis were retrospectively reviewed (phase 1). Risk factors for SSI were analyzed using logistic regression. Phase 2 was a prospective clinical trial investigating the utility of PGE1 at reducing the rate of SSI. Ninety-four patients with spinal metastasis were treated at our institute. The infection rate and risk factors identified in phase 1 and 2 were compared. RESULTS: The rate of SSI during phase 1 was 7.1%. Independent risk factors identified by multivariate logistic regression were diabetes, and preoperative irradiation. The rate of SSI for patients who had irradiation before surgery was 32%, whereas the rate for patients without irradiation was 1.1%. This difference was statistically significant. The rate of SSI in phase 2 was 3.1%. In phase 2 patients who received preoperative irradiation, the rate of SSI was 4.5%. The difference between phase 1 and phase 2 was statistically significant. CONCLUSION: This study identified diabetes and preoperative irradiation to be independent risk factors for SSI in patients with spinal metastasis. PGE1 administration was found to significantly decrease the incidence of SSI in patients with spinal metastasis who underwent preoperative irradiation.全文公開2010031

Outcome of posterior lumbar interbody fusion for L4-L5 degenerative spondylolisthesis

Background: Posterior lumbar interbody fusion (PLIF) has become the standard in the treatment for degenerative spondylolisthesis since improvement of spinal instrumentation However, few published studies have reported long term outcomes of PLIF using a same surgical procedure. The purpose of this study is to evaluate a long term outcome of PLIF using a same surgical procedure for L4-L5 degenerative spondylolisthesis. Materials and Methods: Out of 45 patients who underwent L4-L5 PLIF for degenerative spondylolisthesis between 1995 and 2003, 37 patients (16 males and 21 females) were evaluated in this study. Mean age was 61.8 years. The average followup period was 121 months. We evaluated % slip, lordosis at L4/L5, lumbar lordosis, Japanese Orthopedic Association\u27s (JOA) score and adjacent segment degeneration. Results: The % slip significantly improved from an average of 17.0% before surgery to 9.7% at the last followup. Lordosis at L4/L5 averaged 3.6° before surgery, 8.2° after surgery and 6.9° at the last followup. Although patients experienced some loss of correction at last followup, their lordosis at L4/L5 at last followup still was significantly different from their lordosis at L4/L5 before surgery. Lumbar lordosis did not significantly change. Mean JOA score was 13.4 before surgery and 24.5 at the last followup; mean recovery ratio was 71.2%. Adjacent segment degeneration occurred in 40.5% of patients, almost all of which occurred in the cranial adjacent segment. Three patients (8.1%) required reoperation due to adjacent segment degeneration, at an average of 76 months after their initial surgery. Conclusions: With more than 10-year followup after L4-L5 PLIF for degenerative spondylolisthesis, the adjacent segment degeneration occurred in 40.5% and reoperation was required in 8.1%. © 2015, Medknow Publications Pvt Ltd. All rights reserved