4,529 research outputs found
Novel Compact Three-Way Filtering Power Divider Using Net-Type Resonators
In this paper, we present a novel compact three-way power divider with bandpass responses. The proposed power divider utilizes folded net-type resonators to realize dual functions of filtering and power splitting as well as compact size. Equal power ratio with low magnitude imbalance is achieved due to the highly symmetric structure. For demonstration, an experimental three way filtering power divider is implemented. Good filtering and power division characteristics are observed in the measured results of the circuit. The area of the circuits is 14.5 mm x 21.9 mm or 0.16 λg x 0.24 λg, where the λg is the guide wavelength of the center frequency at 2.1 GHz
Anderson Impurity in Helical Metal
We use a trial wave function to study the spin-1/2 Kondo effect of a helical
metal on the surface of a three-dimensional topological insulator. While the
impurity spin is quenched by conduction electrons, the spin-spin correlation of
the conduction electron and impurity is strongly anisotropic in both spin and
spatial spaces. As a result of strong spin-orbit coupling, the out-of-plane
component of the impurity spin is found to be fully screened by the orbital
angular momentum of the conduction electrons.Comment: The published versio
N-(Anthracen-9-ylmethyl)adamantan-1-amine
In the crystal stucture of the of the title compound, C25H27N, stong π–π interactions are found between adjacent anthracene fragments, with a shortest centroid–centroid distance of 3.5750 (9) Å
Dioscin induces demethylation of DAPK-1 and RASSF-alpha genes via the antioxidant capacity, resulting in apoptosis of bladder cancer T24 cells
DNA methylation at CpG rich regions often occurs at tumor suppressor gene promoters, resulting in
reduced gene expression and final carcinogenesis. Hypermethylation of tumor suppressor genes,
including DAPK-1 and RASSF-1α genes, have been found in patients with bladder carcinoma (BC) in
some western countries. Reactive oxygen species (ROS) was reported to play a causative role in gene
hypermethylation. In this study, we detected the methylation status and expression of DAPK1 and
RASSF-1α genes in tissue samples from Chinese BC pa- tients, using methylation-specific PCR,
reverse transcription PCR and western blotting. Further, we examined the ability of dioscin, a
natural antioxidant, to regulate methylation status and expression of DAPK-1 and RASSF-1α genes in
BC cell lines. In our results, DAPK-1 and RASSF-1α genes showed higher methylation level and lower
express level in BC tissues than matched normal tissues. Treatment with dioscin decreased viability of BC 5637 and T24 cells, but not non-cancer bladder epithelial cell, SV-HUC-1. Dioscin triggered
demethylation of DAPK1 and RASSF-1α genes in T24 cells and increased the gene and protein
expression in 5637 and T24 cells. Both dioscin and substituted antioxidants (N-acetyl cysteine and
Vitamin E) decreased intracellular ROS, but the effect of dioscin was abolished by adding H2O2.
Similar to dioscin, the substituted antioxidants also induced the gene demethylation and T24 cell
apoptosis. Co-treatment with dioscin and H2O2 had no such effects. Collectively, di- of DAPK-1 and
RASSF-1α genes via the antioxidant capacity, resulting in apoptosis of bladder cancer T24 cells or inhibitory cell viability
Fluid-structure interaction modeling on a 3D ray-strengthened caudal fin
In this paper, we present a numerical model capable of solving the fluid-structure interaction problems involved in the dynamics of skeleton-reinforced fish fins. In this model, the fluid dynamics is simulated by solving the Navier-Stokes equations using a finite-volume method based on an overset, multi-block structured grid system. The bony rays embedded in the fin are modeled as nonlinear Euler-Bernoulli beams. To demonstrate the capability of this model, we numerically investigate the effect of various ray stiffness distributions on the deformation and propulsion performance of a 3D caudal fin. Our numerical results show that with specific ray stiffness distributions, certain caudal fin deformation patterns observed in real fish (e.g. the cupping deformation) can be reproduced through passive structural deformations. Among the four different stiffness distributions (uniform, cupping, W-shape and heterocercal) considered here, we find that the cupping distribution requires the least power expenditure. The uniform distribution, on the other hand, performs the best in terms of thrust generation and efficiency. The uniform stiffness distribution, per se, also leads to 'cupping' deformation patterns with relatively smaller phase differences between various rays. The present model paves the way for future work on dynamics of skeleton-reinforced membranes
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