DC-assisted microwave quenching of YBa2Cu3O7-{\delta} coplanar waveguide to a highly dissipative state

The paper reports on finding the effect of a strong change in the microwave losses in an HTS-based coplanar waveguide (CPW) at certain values of the input power Pin and direct current Idc. CPW on the basis of 150 nm thick YBa2Cu3O7-{\delta} epitaxial film on a single crystal MgO substrate was studied experimentally. A sharp and reversible transition of the CPW into a strongly dissipative state at the certain meanings of Pin and Idc depending on temperature was observed. Apparently the effect can be explained by self-heating of HTS structure caused by magnetic flux flow under the joint influence of MW and DC.Comment: 9 pages, 5 figures, 17 reference

Aneurysm of a paraumbilical collateral vein.

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135619/1/jum1988711639.pd

HuR overexpression in MB231 breast cancer cells

Abstract only availableCancer cells share acquired capabilities necessary for their malignant transformation. These "hallmarks of cancer" include increased proliferation, self-sufficiency in growth signals, insensitivity to antigrowth signals, evasion of apoptosis, angiogenesis and metastasis (Hanahan and Weinberg 2000). HuR is a RNA-binding protein which has been implicated in regulating mRNAs involved in each of these characteristics. We hypothesize that HuR maintains the growth characteristics of malignant cancer cells through the stabilization and increased translation of cancer relevant genes. If HuR does enhance malignancy then the overexpression of HuR would amplify the capabilites of malignant cancer cells and increase cell proliferation. This hypothesis was tested by creating a breast cancer cell line that stably overexpresses HuR. A vector overexpressing HuR was created by ligating a PCR amplified insert containing HuR and a HA hemagluttin tag into a Zeocin resistant episomal plasmid. Cells normally express HuR, so the tag was used to distinguish the overexpressed HuR from endogenous HuR. This plasmid was used to transfect MB-231 estrogen receptor-negative breast cancer cells. After transfection, Zeocin selected against the cells that did not incorporate the plasmid. Western Blots for the surviving cells revealed that HA HuR was expressed, implying that the cells were overexpressing HuR. Proliferation assays of heterogenous populations of both HA HuR-containing and normal MB231 cells yield no difference in cell division. Further experiments will use homogenous populations that highly overexpress HuR to see if HuR overexpression alters the proliferation and cell cycle capabilities of these cells. References: "Hallmarks of Cancer" Hanahan, Douglas and Weinberg, Robert A. Cell. Vol. 100, 57-70. 200

The Features of Surface Plasmon-Polariton Pulses Generation Via Cooperative Effects in Waveguide Spaser

The problem of sub-picosecond plasmon-polariton pulse formation in metal/dielectric interface due to collective decay of excited quantum dots, placed in the dielectric layer near the metal surface, is considered. Theoretical approach to selection of semiconductor quantum dots and dielectric host medium to increase the energy transmission of quantum dot collective excitations into surface plasmon-polariton modes of waveguide spaser is developed

Quantum chaos: an introduction via chains of interacting spins-1/2

We introduce aspects of quantum chaos by analyzing the eigenvalues and the eigenstates of quantum many-body systems. The properties of quantum systems whose classical counterparts are chaotic differ from those whose classical counterparts are not chaotic. The spectrum of the first exhibits repulsion of the energy levels. This is one of the main signatures of quantum chaos. We show how level repulsion develops in one-dimensional systems of interacting spins 1/2 which are devoid of random elements and involve only two-body interactions. In addition to the statistics of the eigenvalues, we analyze how the structure of the eigenstates may indicate chaos. The programs used to obtain the data are available online.Comment: 7 pages, 3 figure

Noise-induced topological transformations of vortex solitons in optical fibers filled with a cold atomic gas

We consider the influence of optical and temperature-dependent atomic fluctuations on the formation and propagation of optical vortex solitons in dense media realized as hollow-core optical fibers filled with a cold atomic gas in presence of optical pumping. We show different perturbation-induced scenaria of complete destruction and smooth transformations of the topological characteristics of localized optical structures in hollow-core fiber. The maximum levels of optical and atomic fluctuations at which the soliton regime can be maintained has been determined. The estimates for these levels show an opportunity to observe the optical vortex solitions in the core-filling gas of the fiber for temperatures smaller than the critical temperature for Bose-Einstein condensate.Comment: 12 pages, 10 EPS figures, submitted to Physical Review

Multiresonances of quasi-trapped modes in metasurfaces based on nanoparticles of transition metal dichalcogenides

The features of polarization control of multiple multiresonances for quasi-trapped modes excited by synchronization of bianisotropic dipole responses in MoS$_2$ disks with a hole are considered. Using the numerical calculations with analytical multipole analysis, we showed that the presence of a strong optical anisotropy of MoS$_2$ nanoparticles provides an additional degree of freedom and allows to observe several resonances of electric and magnetic dipoles at once in a narrow spectral range. Based on the simulation results, we obtained the frequency dependences for the dipole polarizabilities of the MoS$_2$ disk with a hole, which allow one to distinguish the contributions of the nonlocal and bianisotropic dipole responses and possessing several features in the near infrared range. Using the polarizability spectra of single nanoparticles and applying the tuning strategy, the design of the MoS$_2$ metasurface supporting three resonances of quasi-trapped modes at once in a narrow spectral range was developed. One of these resonances corresponds to the telecom wavelength of 1550 nm. The spectrum of light reflection for MoS$_2$ metasurface is characterized by three narrowband dips corresponding to the wavelengths of the quasi-trapped modes. It was shown that a change in the polarization of a wave normally incident on the metasurface to orthogonal one leads to a change in the type of bianisotropic response excited in each MoS$_2$ disk and to the excitation of three other features in the reflection spectra of the metasurface at wavelengths close to the initial values.Comment: 8 pages, 5 figure