61 research outputs found

    Compressed Exponential Relaxation as Superposition of Dual Structure in Pattern Dynamics of Nematic Liquid Crystals

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    Soft-mode turbulence (SMT) is the spatiotemporal chaos observed in homeotropically aligned nematic liquid crystals, where non-thermal fluctuations are induced by nonlinear coupling between the Nambu-Goldstone and convective modes. The net and modal relaxations of the disorder pattern dynamics in SMT have been studied to construct the statistical physics of nonlinear nonequilibrium systems. The net relaxation dynamics is well-described by a compressed exponential function and the modal one satisfies a dual structure, dynamic crossover accompanied by a breaking of time-reversal invariance. Because the net relaxation is described by a weighted mean of the modal ones with respect to the wave number, the compressed-exponential behavior emerges as a superposition of the dual structure. Here, we present experimental results of the power spectra to discuss the compressed-exponential behavior and the dual structure from a viewpoint of the harmonic analysis. We also derive a relationship of the power spectra from the evolution equation of the modal autocorrelation function. The formula will be helpful to study non-thermal fluctuations in experiments such as the scattering methods.Comment: 17pages, 3 figures, to be published on AIP conference proceedings for "The 4th International Symposium on Slow Dynamics in Complex Systems

    Stereoselective Total Synthesis of Myriocin Using Rh(II)-Catalyzed C–H Amination Followed by Alkylation

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    The stereoselective total synthesis of myriocin was achieved by using the Du Bois Rh(II)-catalyzed C−H amination of sulfamate 6 and a subsequent alkylation. The reaction of sulfamate 6 with PhI(OAc)2 and MgO in the presence of Rh2(OAc)4 gave oxathiazinane N,O-acetal as the sole product in high yield. Alkylation of the N,O-acetal using vinylmagnesium bromide in the presence of ZnCl2 proceeded stereoselectively to provide an oxathiazinane bearing a quaternary chiral center in high yield. This route includes the first application of the Du Bois procedure for the construction of a quaternary chiral center

    Active Brownian Motion in Threshold Distribution of a Coulomb Blockade Model

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    Randomly-distributed offset charges affect the nonlinear current-voltage property via the fluctuation of the threshold voltage of Coulomb blockade arrays. We analytically derive the distribution of the threshold voltage for a model of one-dimensional locally-coupled Coulomb blockade arrays, and propose a general relationship between conductance and the distribution. In addition, we show the distribution for a long array is equivalent to the distribution of the number of upward steps for aligned objects of different height. The distribution satisfies a novel Fokker-Planck equation corresponding to active Brownian motion. The feature of the distribution is clarified by comparing it with the Wigner and Ornstein-Uhlenbeck processes. It is not restricted to the Coulomb blockade model, but instructive in statistical physics generally.Comment: 4pages, 3figure

    Do calcineurin inhibitors influence the serum concentrations of mizoribine?

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    Background: Mizoribine (MZR) is an antimetabolite that inhibits inosine-monophosphate dehydrogenase and has been used for preventing rejection in renal transplantation. However, the effect of calcineurin inhibitors (CNIs) on the pharmacokinetics of MZR has not been shown. This study was performed to show the influence of CNIs (tacrolimus [Tac] or cyclosporine [CyA]) on the serum concentration of MZR.Methods: Thirty-four living-donor renal transplant recipients administered a four-drug immunosuppressive therapy regimen (steroid, CNIs, basiliximab and MZR 6 mg/kg/day) were investigated. 20 recipients were treated with Tac and 14 were with CyA. Serum concentrations of MZR were obtained retrospectively at 464 points and at 243 points for each. Population pharmacokinetic (PPK) analysis was used to make pharmacokinetic models of serum MZR. After statistically evaluating the correlation of the pharmacokinetic models with the actual data, areas under the curves (AUCs) of each CNI were also estimated in these models and statistically evaluated.Results: The mean values of the PPK parameters (absorption lag time, absorption rate constant [Ka], apparent volume of distribution [V/F] and oral clearance of MZR [CLMZR/F]) were 0.600 hr and 0.643 hr, 1.14/hr and 0.911/hr, 0.732×body weight (WT) (L) and 0.784×WT (L), and 1.64×creatinine clearance (CLcr) (L/hr) and 1.81×CLcr (L/hr), respectively. Moreover, the serum concentrations of MZR at all-time points were estimated with these parameters. The correlation coefficients between the individual actual and estimated serum concentrations of MZR in the Tac group and the CyA group were 0.988 and 0.992, respectively. The average value of the AUCs of MZR corrected by the CLcr in the Tac group, and the CyA group were 0.61±0.21 and 0.55±0.19 (average value±standard deviation) for each (p=0.19).Conclusion: These findings suggest the pharmacokinetics of MZR were well-described by 1-compartment model with first-order absorption. Moreover, concomitant use of CNIs, e.g., Tac and CyA, may have no significant influence on the pharmacokinetics of MZR
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