虚血性神経細胞死におけるCAD(caspase-activated DNase)とDNase2の関与

取得学位：博士(医学)，学位授与番号：医博甲第1464号，学位授与年月日：平成13年3月31日,学位授与年：200

Ferromagnetism in a Hubbard model for an atomic quantum wire: a realization of flat-band magnetism from even-membered rings

We have examined a Hubbard model on a chain of squares, which was proposed by Yajima et al as a model of an atomic quantum wire As/Si(100), to show that the flat-band ferromagnetism according to a kind of Mielke-Tasaki mechanism should be realized for an appropriate band filling in such a non-frustrated lattice. Reflecting the fact that the flat band is not a bottom one, the ferromagnetism vanishes, rather than intensified, as the Hubbard U is increased. The exact diagonalization method is used to show that the critical value of U is in a realistic range. We also discussed the robustness of the magnetism against the degradation of the flatness of the band.Comment: misleading terms and expressions are corrected, 4 pages, RevTex, 5 figures in Postscript, to be published in Phys. Rev. B (rapid communication

Magnetic thickness measurement for various iron steels using magnetic sensor and effect of electromagnetic characteristics

The diagnosis and prevention of the deterioration of iron-steel infrastructure has become an important social issue in recent years. The thickness measurement technique (extremely low-frequency eddy current testing (ELECT)) using a magnetic sensor for detecting steel corrosion at extreme frequency ranges has been previously reported. Using the calibration curves based on the correlation between the phase of the detected magnetic signal and the plate thickness, the plate thickness reduction caused by corrosion can be estimated from the detected phase signal. Iron-steel materials have large changes in electromagnetic characteristics; therefore, the reference calibration data for each type of iron-steel are required for plate thickness estimation. In this study, the effect of electromagnetic characteristics on the magnetic thickness measurement was investigated to improve the thickness estimation. Four types of iron-steel plates (SS400, SM400A, SM490A, and SMA400AW) with thicknesses ranging from 1 mm to 18 mm were measured by ELECT, and the phase change at multiple frequencies of each plate were analyzed. The shift in the phase and linearity regions of the calibration curves for each type of steel plate was observed. To analyze this shift phenomenon, the electromagnetic characteristics (permeability μ and conductivity σ) of each type of steel were measured. Compared with the permeability μ and conductivity σ of each steel plate in the applied magnetic field strength range, the product (σμ) for various steel plates decreased in the following order: SM400 > SS400 >SMA400AW > SM490A. The product of μ and σ is related to the skin depth, indicating the electromagnetic wave attenuation and eddy current phase shift in the material. Therefore, each shift in the calibration curve of each type of iron steel is explained by the changes in the parameters σ and μ

Prediction of DAS28-ESR remission at 6 months by baseline variables in patients with rheumatoid arthritis treated with etanercept in Japanese population

We tried to determine which baseline variables are responsible for remission induction at 6 months in unselected rheumatoid arthritis (RA) patients of Japanese population treated with etanercept. One hundred forty-one patients with RA who were administered etanercept were registered. Thirty-four patients were started on etanercept monotherapy, 60 patients on cotherapy with methotrexate (MTX) (MTX cotherapy), and 47 patients on cotherapy with other non-MTX nonbiologic disease-modifying antirheumatic drugs (DMARDs) (non-MTX cotherapy). None of the patients were treated with both MTX and non-MTX nonbiologic DMARDs at entry. Outcome was set as achievement of disease activity score 28 (DAS28)-ESR remission at 6 months. We examined association of gender, DAS at baseline, MTX cotherapy at baseline, non-MTX cotherapy at baseline, and prednisolone use at baseline with achievement of remission at 6 months by logistic regression analysis. All subjects were classified as having high (N = 109) or moderate disease activity (N = 32) at entry. One hundred twenty out of 141 patients (85.1%) continued treatment with etanercept at 6 months. Continuation rate was statistically higher in MTX cotherapy (93.3%) compared with etanercept monotherapy (73.5%), and tended to be higher than with non-MTX cotherapy (85.1%). Logistic regression analysis identified that MTX cotherapy at entry and moderate disease activity at entry were independent variables for remission induction at 6 months. Accordingly, DAS28-ESR at 6 months was significantly lower with MTX cotherapy as compared with etanercept monotherapy or non-MTX cotherapy. To a lesser extent, DAS28-ESR with non-MTX cotherapy at 6 months was lower than with etanercept monotherapy. In this study of unselected patients, use of MTX and moderate disease activity at entry were associated with higher likelihood of response to etanercept. Non-MTX nonbiologic DMARDs may be an alternative in RA patients administrated etanercept who are intolerant to MTX