Superconductivity and Rattling under High Pressure in the beta-Pyrochlore Oxide RbOs2O6

Rattling-induced superconductivity in the beta-pyrochlore oxide RbOs2O6 is investigated under high pressures up to 6 GPa. Resistivity measurements in a high-quality single crystal show that the superconducting transition temperature Tc increases gradually from 6.3 K at ambient pressure to 8.8 K at 3.5 GPa, surprisingly remains almost constant at 8.8 \pm 0.1 K in a wide pressure range between 3.5 (Po) and 4.8 GPa, and suddenly drops to 6.3 K at Ps = 4.9 GPa, followed by a gradual decrease with further pressure increase. Two anomalies in the temperature dependence of the normal-state resistivity are observed at Po Ps, revealing the presence of two high-pressure phases corresponding to the changes in Tc. The rattling of the Rb ion inside a cage made of Os and O atoms may be slightly and seriously modified in these high-pressure phases that probably have cages of reduced symmetry, respectively, so that electron-rattler interactions that govern the superconducting and transport properties of beta-RbOs2O6 are significantly affected.Comment: arXiv admin note: text overlap with arXiv:1009.035

Nonlinearity and disorder: Classification and stability of nonlinear impurity modes

We study the effects produced by competition of two physical mechanisms of energy localization in inhomogeneous nonlinear systems. As an example, we analyze spatially localized modes supported by a nonlinear impurity in the generalized nonlinear Schr\"odinger equation and describe three types of nonlinear impurity modes --- one- and two-hump symmetric localized modes and asymmetric localized modes --- for both focusing and defocusing nonlinearity and two different (attractive or repulsive) types of impurity. We obtain an analytical stability criterion for the nonlinear localized modes and consider the case of a power-law nonlinearity in detail. We discuss several scenarios of the instability-induced dynamics of the nonlinear impurity modes, including the mode decay or switching to a new stable state, and collapse at the impurity site.Comment: 18 pages, 22 figure

Cascaded logic gates in nanophotonic plasmon networks

Optical computing has been pursued for decades as a potential strategy for advancing beyond the fundamental performance limitations of semiconductor-based electronic devices, but feasible on-chip integrated logic units and cascade devices have not been reported. Here we demonstrate that a plasmonic binary NOR gate, a 'universal logic gate', can be realized through cascaded OR and NOT gates in four-terminal plasmonic nanowire networks. This finding provides a path for the development of novel nanophotonic on-chip processor architectures for future optical computing technologies

Flattening effect of four wave mixing on multiwavelength Brillouin-erbium fiber laser.

A multiwavelength Brillouin-erbium fiber laser with enhanced output uniformity is demonstrated and its performance with and without the assistance of four wave mixing (FWM) is compared. The presence of FWM effect is proven by the generation of anti-Stokes wave and higher-order Stokes wave. This scheme is successful in flattening the multiwavelength output. At Brillouin pump wavelength of 1,550 nm, between the first and the last output channel, peak power differences of 4.59 and 8.32 dB are recorded for the scheme with and without the assistance of FWM, respectively. This represents 3.73 dB improvement in the multiwavelength output power uniformity

Optical snakes and ladders: dispersion and nonlinearity in microcoil resonators

Microcoil resonators are a radical new geometry for high Q resonators with unique linear features. In this paper I briefly summarise their linear properties before extending the analysis to nonlinear interactions in microcoil resonators. As expected such nonlinear resonators are bistable and exhibit hysteresis. Finally I discuss possible applications and extensions to such resonators

Possible impact of the CYP2D6*10 polymorphism on the nonlinear pharmacokinetic parameter estimates of paroxetine in Japanese patients with major depressive disorders

Junji Saruwatari,1 Hiroo Nakashima,1 Shoko Tsuchimine,2 Miki Nishimura,1 Naoki Ogusu,1 Norio Yasui-Furukori21Division of Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan; 2Department of Neuropsychiatry, Graduate School of Medicine, Hirosaki University, Hirosaki, JapanAbstract: It has been suggested that the reduced function allele with reduced cytochrome P450 (CYP) 2D6 activity, CYP2D6*10, is associated with the interindividual differences in the plasma paroxetine concentrations, but there is no data presently available regarding the influence of the CYP2D6*10 polymorphism on the pharmacokinetic parameters, eg, Michaelis–Menten constant (Km) and maximum velocity (Vmax), in Asian populations. The present study investigated the effects of the CYP2D6 polymorphisms, including CYP2D6*10, on the pharmacokinetic parameters of paroxetine in Japanese patients with major depressive disorders. This retrospective study included 15 Japanese patients with major depressive disorders (four males and eleven females) who were treated with paroxetine. The CYP2D6*2, CYP2D6*4, CYP2D6*5, CYP2D6*10, CYP2D6*18, CYP2D6*39, and CYP2D6*41 polymorphisms were evaluated. A total of 56 blood samples were collected from the patients. The Km and Vmax values of paroxetine were estimated for each patient. The allele frequencies of CYP2D6*2, CYP2D6*4, CYP2D6*5, CYP2D6*10, CYP2D6*18, CYP2D6*39, and CYP2D6*41 were 6.7%, 0%, 10.0%, 56.7%, 0%, 26.7%, and 0%, respectively. The mean values of Km and Vmax were 50.5±68.4 ng/mL and 50.6±18.8 mg/day, respectively. Both the Km and Vmax values were significantly smaller in CYP2D6*10 allele carriers than in the noncarriers (24.2±18.3 ng/mL versus 122.5±106.3 ng/mL, P=0.008; 44.2±16.1 mg/day versus 68.3±15.0 mg/day, P=0.022, respectively). This is the first study to demonstrate that the CYP2D6*10 polymorphism could affect the nonlinear pharmacokinetic parameter estimates of paroxetine in Asian populations. The findings of this study suggest that the CYP2D6*10 polymorphism may be associated with the smaller values of both the Km and Vmax in Japanese patients with major depressive disorders, and these results need to be confirmed in further investigations with a larger number of patients.Keywords: pharmacokinetics, dose requirement, Michaelis–Menten constant, maximum velocit

Possible association between moderate intellectual disability and weight gain in valproic acid–treated patients with epilepsy

Yukiko Tanamachi,1 Junji Saruwatari,1 Madoka Noai,1 Ryoko Kamihashi,1 Hiromi Soraoka,1 Yuki Yoshimori,1 Naoki Ogusu,1 Kentaro Oniki,1 Norio Yasui-Furukori,2 Takateru Ishitsu,3,4 Kazuko Nakagawa1,5 1Division of Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan; 2Department of Neuropsychiatry, Hirosaki University School of Medicine, Hirosaki, Japan; 3Kumamoto Saishunso National Hospital, Koshi, Japan; 4Kumamoto Ezuko Ryoiku Iryo Center, Kumamoto, Japan; 5Center for Clinical Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan Background: Although patients with moderate intellectual disability (ID) are known to have higher rates of being overweight and obese than those without ID, there are no current data regarding the relationship between ID and weight gain in epilepsy patients treated with valproic acid (VPA). Patients and methods: The possible association between moderate ID and an overweight status at the time of initiation of VPA therapy (baseline) was investigated using a logistic regression analysis in 143 patients with epilepsy. Among the 119 nonoverweight patients at baseline, the longitudinal association between moderate ID and the weight status during VPA therapy was retrospectively examined using a Cox hazards regression analysis and the generalized estimating equations approach, while also paying careful attention to associations with other patient characteristics. Results: The proportion of patients with moderate ID was 52.4% among the 143 study subjects. The presence of moderate ID was not associated with an overweight status at baseline (P=0.762). Among the nonoverweight patients at baseline, 16 subjects were newly diagnosed as being overweight during treatment with VPA (3.6±2.1 years). The presence of moderate ID was significantly associated with the incidence of an overweight status after starting VPA therapy (adjusted hazard ratio =6.72, P=0.007). The patient age at baseline and treatment with co-administered carbamazepine, clobazam, and zonisamide significantly influenced the degree of weight fluctuation during VPA therapy among the patients with moderate ID (P<0.001, P<0.001, P=0.002, and P=0.028, respectively), whereas only patient age at baseline affected this parameter among the patients without moderate ID (P=0.022). Conclusion: The present findings suggest that the weight status should be carefully monitored in VPA-treated patients with moderate ID, especially those receiving other co-administered antiepileptic drugs that facilitate weight gain, such as carbamazepine. Keywords: overweight, weight status, obesity, antiepileptic drug, longitudinal analysis&nbsp