403 research outputs found

    Spin susceptibility for orbital-singlet Cooper pair in the three-dimensional Sr₂RuO₄ superconductor

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    We study the spin susceptibility of the orbital-singlet pairings, including the spin-triplet/orbital-singlet/s-wave Eg representation proposed by Suh et al. [H. G. Suh et al., Phys. Rev. Research 2, 032023(R) (2020)], for a three-orbital model of superconducting Sr₂RuO₄ in three dimensions. For the pseudospin-singlet states represented in the band basis, the spin susceptibility decreases when reducing the temperature, irrespective of the direction of the applied magnetic fields, even if they are spin-triplet/orbital-singlet pairings in the spin-orbital space. However, because the pseudospin-triplet d-vector in the band basis is not completely aligned in the xy-plane (along z-axis) owing to the strong atomic spin-orbit coupling, the spin susceptibility for spin-singlet/orbital-singlet/odd-parity pairings is reduced around 5–10 percent with the decrease of the temperature along the z (x) axis. We can determine the symmetry of the pseudospin structure of the Cooper pair by the temperature dependence of the spin susceptibility measured by nuclear magnetic resonance experiments. Our obtained results serve as a guide to determine the pairing symmetry of Sr₂RuO₄

    Impaired long-term memory retention and working memory in sdy mutant mice with a deletion in Dtnbp1, a susceptibility gene for schizophrenia

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    <p>Abstract</p> <p>Background</p> <p>Schizophrenia is a complex genetic disorder caused by multiple genetic and environmental factors. The dystrobrevin-binding protein 1 (DTNBP1: dysbindin-1) gene is a major susceptibility gene for schizophrenia. Genetic variations in DTNBP1 are associated with cognitive functions, general cognitive ability and memory function, and clinical features of patients with schizophrenia including negative symptoms and cognitive decline. Since reduced expression of dysbindin-1 has been observed in postmortem brains of patients with schizophrenia, the sandy (sdy) mouse, which has a deletion in the Dtnbp1 gene and expresses no dysbindin-1 protein, could be an animal model of schizophrenia. To address this issue, we have carried out a comprehensive behavioral analysis of the sdy mouse in this study.</p> <p>Results</p> <p>In a rotarod test, sdy mice did not exhibit motor learning whilst the wild type mice did. In a Barnes circular maze test both sdy mice and wild type mice learned to selectively locate the escape hole during the course of the training period and in the probe trial conducted 24 hours after last training. However, sdy mice did not locate the correct hole in the retention probe tests 7 days after the last training trial, whereas wild type mice did, indicating impaired long-term memory retention. A T-maze forced alternation task, a task of working memory, revealed no effect of training in sdy mice despite the obvious effect of training in wild type mice, suggesting a working memory deficit.</p> <p>Conclusion</p> <p>Sdy mouse showed impaired long-term memory retention and working memory. Since genetic variation in DTNBP1 is associated with both schizophrenia and memory function, and memory function is compromised in patients with schizophrenia, the sdy mouse may represent a useful animal model to investigate the mechanisms of memory dysfunction in the disorder.</p

    膵癌術後予防肝動注におけるリザーバー留置術の検討 : 従来法とcoaxialシステムの比較

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    PURPOSE: Previous reports have shown the effectiveness of adjuvant hepatic arterial infusion chemotherapy (HAIC) in pancreatic cancer. However, percutaneous catheter placement is technically difficult after pancreatic surgery. The purpose of this study was to evaluate the feasibility and outcome of HAIC using a coaxial technique compared with conventional technique for postoperative pancreatic cancer. MATERIALS AND METHODS: 93 consecutive patients who received percutaneous catheter-port system placement after pancreatectomy were enrolled. In 58 patients from March 2006 to August 2010 (Group A), a conventional technique with a 5-Fr indwelling catheter was used and in 35 patients from September 2010 to September 2012 (Group B), a coaxial technique with a 2.7-Fr coaxial catheter was used. RESULTS: The overall technical success rates were 97.1 % in Group B and 86.2 % in Group A. In cases with arterial tortuousness and stenosis, the success rate was significantly higher in Group B (91.7 vs. 53.8 %; P = 0.046). Fluoroscopic and total procedure times were significantly shorter in Group B: 14.7 versus 26.7 min (P = 0.001) and 64.8 versus 80.7 min (P = 0.0051), respectively. No differences were seen in the complication rate. The 1 year liver metastasis rates were 9.9 % using the conventional system and 9.1 % using the coaxial system (P = 0.678). The overall median survival time was 44 months. There was no difference in the survival period between two systems (P = 0.312). CONCLUSIONS: The coaxial technique is useful for catheter placement after pancreatectomy, achieving a high success rate and reducing fluoroscopic and procedure times, while maintaining the safety and efficacy for adjuvant HAIC in pancreatic cancer.博士(医学)・乙第1380号・平成28年7月8日© Springer Science+Business Media New York and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2016The final publication is available at Springer via http://dx.doi.org/10.1007/s00270-016-1292-

    Investigation of the feasibility of a simple method for verifying the motion of a binary multileaf collimator synchronized with the rotation of the gantry for helical tomotherapy

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    In this paper, we suggest a new method for verifying the motion of a binary multileaf collimator (MLC) in helical tomotherapy. For this we used a combination of a cylindrical scintillator and a general-purpose camcorder. The camcorder records the light from the scintillator following photon irradiation, which we use to track the motion of the binary MLC. The purpose of this study is to demonstrate the feasibility of this method as a binary MLC quality assurance (QA) tool. First, the verification was performed using a simple binary MLC pattern with a constant leaf open time; secondly, verification using the binary MLC pattern used in a clinical setting was also performed. Sinograms of simple binary MLC patterns, in which leaves that were open were detected as "open" from the measured light, define the sensitivity which, in this case, was 1.000. On the other hand, the specificity, which gives the fraction of closed leaves detected as "closed", was 0.919. The leaf open error identified by our method was -1.3 +/- 7.5%. The 68.6% of observed leaves were performed within +/- 3% relative error. The leaf open error was expressed by the relative errors calculated on the sinogram. In the clinical binary MLC pattern, the sensitivity and specificity were 0.994 and 0.997, respectively. The measurement could be performed with -3.4 +/- 8.0% leaf open error. The 77.5% of observed leaves were performed within +/- 3% relative error. With this method, we can easily verify the motion of the binary MLC, and the measurement unit developed was found to be an effective QA tool.ArticleJOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS. 13(1):27-43 (2012)journal articl
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