Mild and moderate pre-dialysis chronic kidney disease is associated with increased coronary artery calcium.

BackgroundIt is increasingly evident that patients with chronic kidney disease (CKD) are more likely to die from heart disease than kidney failure. This study evaluated whether pre- dialysis CKD is an independent risk factor for coronary artery calcium (CAC).MethodsA total of 544 consecutive patients who underwent CAC scoring were analyzed. Eleven patients requiring hemodialysis were excluded. Patients were divided into three groups: normal glomerular filtration rate (GFR) (GFR > 90 mL/min/1.73 m²), mild CKD (90 ≥ GFR > 60 mL/min/1.73 m²), and moderate CKD (60 ≥ GFR > 30 mL/min/1.73 m²). Continuous and categorical variables were compared using analysis of variance and the χ² statistic. A multiple logistic regression model was used for detecting the association between total CAC score and GFR. An unadjusted model was used, followed by a second model adjusted for covariates known to be related to CAC. Another multivariable binary logistic model predicting the presence of CAC (>10) was performed and odds of incidence of CAC (>10) were calculated among the three GFR subgroups.ResultsAfter adjustment for covariates, patients with mild CKD had mean CAC scores 175 points higher than those with the referent normal GFR (P = 0.048), while those with moderate CKD had mean CAC scores 693 points higher than the referent (P < 0.001). After adjustment for covariates, patients with mild CKD were found to be 2.2 times more likely (95% confidence interval 1.3-3.7, P = 0.004) and patients with moderate CKD were 6.4 times more likely (95% confidence interval 2.9-14.3, P < 0.001) to have incident CAC compared with the group with normal GFR.ConclusionMild and moderate pre-dialysis CKD are independent risk factors for increased mean and incident CAC

Non-Gaussianity and gravitational wave background in curvaton with a double well potential

We study the density perturbation by a curvaton with a double well potential and estimate the nonlinear parameters for non-Gaussianity and the amplitude of gravitational wave background generated during inflation. The predicted nonlinear parameters strongly depend on the size of a curvaton self-coupling constant as well as the reheating temperature after inflation for a given initial amplitude of the curvaton. The difference from usual massive self-interacting curvaton is also emphasized.Comment: 23 pages, 6 figure

Modulated reheating by curvaton

There might be a light scalar field during inflation which is not responsible for the accelerating inflationary expansion. Then, its quantum fluctuation is stretched during inflation. This scalar field could be a curvaton, if it decays at a late time. In addition, if the inflaton decay rate depends on the light scalar field expectation value by interactions between them, density perturbations could be generated by the quantum fluctuation of the light field when the inflaton decays. This is modulated reheating mechanism. We study curvature perturbation in models where a light scalar field does not only play a role of curvaton but also induce modulated reheating at the inflaton decay. We calculate the non-linearity parameters as well as the scalar spectral index and the tensor-to-scalar ratio. We find that there is a parameter region where non-linearity parameters are also significantly enhanced by the cancellation between the modulated effect and the curvaton contribution. For the simple quadratic potential model of both inflaton and curvaton, both tensor-to-scalar ratio and nonlinearity parameters could be simultaneously large.Comment: 26 pages, 22 figure

Origins of anomalous electronic structures of epitaxial graphene on silicon carbide

On the basis of first-principles calculations, we report that a novel interfacial atomic structure occurs between graphene and the surface of silicon carbide, destroying the Dirac point of graphene and opening a substantial energy gap there. In the calculated atomic structures, a quasi-periodic $6\times 6$ domain pattern emerges out of a larger commensurate $6\sqrt{3}\times6\sqrt{3}R30^\circ$ periodic interfacial reconstruction, resolving a long standing experimental controversy on the periodicity of the interfacial superstructures. Our theoretical energy spectrum shows a gap and midgap states at the Dirac point of graphene, which are in excellent agreement with the recently-observed anomalous angle-resolved photoemission spectra. Beyond solving unexplained issues of epitaxial graphene, our atomistic study may provide a way to engineer the energy gaps of graphene on substrates.Comment: Additional references added; published version; 4 pages, 4 figure

Can Standard Model Higgs Seed the Formation of Structures in Our Universe?

We study the Standard Model Higgs field as a source for the primordial curvature perturbation, particularly in the curvaton and modulated reheating scenario. We conclude that the Higgs cannot play as a curvaton due to the small energy density when it decays, however the modulated reheating by Higgs can be a viable scenario. In the latter case, the non-Gaussianity is inevitably generated and strongly constrains the type of potential of inflaton field and Higgs-dependent interaction term. For the quadratic potential of the inflaton field with decay rate which non-linearly depends on the Higgs vacuum expectation value, the contribution of Higgs field to the primordial curvature perturbation must be less than 8%.Comment: 12 pages; version accepted for publication in Phys.Rev.

Polymerization of ethylene oxide using yttrium isopropoxide

Well defined poly(ethylene oxide)s were prepared using yttrium isopropoxide as an initiator. End group analysis using 1H- and 13C NMR spectroscopy revealed that only polymers with isopropyl ether and hydroxyl end groups were produced. The molecular weight is controlled by the initial amount of initiator added and low polydispersity polymer (Mw/Mn ≈ 1.1) was isolated. Sequential polymerization indicated the suitability of this initiator for macromolecular engineering

LHC Signature of Mirage Mediation

We study LHC phenomenology of mirage mediation scenario in which anomaly and modulus contributions to soft SUSY breaking terms are comparable to each other. A Monte Carlo study of mirage mediation, with model parameters $\alpha=1$,$M_0=500$ GeV, $n_M=1/2$, $n_H=1$ and $\rm{tan}\beta=10$, is presented. It is shown that masses of supersymmetric particles can be measured in a model independent way, providing information on SUSY breaking sector. In particular, the mass ratio of gluino to the lightest neutralino for the benchmark scenario is determined to be 1.9 \lesssim m_{\tildeg}/m_{\tilde\chi_1^0} \lesssim 3.1, well reproducing theoretical input value of $m_{\tilde g}/m_{\tilde\chi_1^0} \simeq 2.5$ which is quite distinctive from the predictions $m_{\tilde g}/m_{\tilde\chi_1^0} \gtrsim 6$ of other SUSY scenarios in which gaugino masses are unified at the GUT scale. The model parameters of mirage mediation can be also determined from various kinematic distributions

X-ray induced electronic structure change in CuIr2_2S4_4

The electronic structure of CuIr$_2$S$_4$ has been investigated using various bulk-sensitive x-ray spectroscopic methods near the Ir $L_3$-edge: resonant inelastic x-ray scattering (RIXS), x-ray absorption spectroscopy in the partial fluorescence yield (PFY-XAS) mode, and resonant x-ray emission spectroscopy (RXES). A strong RIXS signal (0.75 eV) resulting from a charge-density-wave gap opening is observed below the metal-insulator transition temperature of 230 K. The resultant modification of electronic structure is consistent with the density functional theory prediction. In the spin- and charge- dimer disordered phase induced by x-ray irradiation below 50 K, we find that a broad peak around 0.4 eV appears in the RIXS spectrum.Comment: 4 pages and 4 figure