34 research outputs found

    Statistics of level spacing of geometric resonances in random binary composites

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    We study the statistics of level spacing of geometric resonances in the disordered binary networks. For a definite concentration pp within the interval [0.2,0.7][0.2,0.7], numerical calculations indicate that the unfolded level spacing distribution P(t)P(t) and level number variance ÎŁ2(L)\Sigma^2(L) have the general features. It is also shown that the short-range fluctuation P(t)P(t) and long-range spectral correlation ÎŁ2(L)\Sigma^2(L) lie between the profiles of the Poisson ensemble and Gaussion orthogonal ensemble (GOE). At the percolation threshold pcp_c, crossover behavior of functions P(t)P(t) and % \Sigma^2(L) is obtained, giving the finite size scaling of mean level spacing ÎŽ\delta and mean level number nn, which obey the scaling laws, % \delta=1.032 L ^{-1.952} and n=0.911L1.970n=0.911L^{1.970}.Comment: 11 pages, 7 figures,submitted to Phys. Rev.

    Fluctuations and scaling of inverse participation ratios in random binary resonant composites

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    We study the statistics of local field distribution solved by the Green's-function formalism (GFF) [Y. Gu et al., Phys. Rev. B {\bf 59} 12847 (1999)] in the disordered binary resonant composites. For a percolating network, the inverse participation ratios (IPR) with q=2q=2 are illustrated, as well as the typical local field distributions of localized and extended states. Numerical calculations indicate that for a definite fraction pp the distribution function of IPR PqP_q has a scale invariant form. It is also shown the scaling behavior of the ensemble averaged described by the fractal dimension DqD_q. To relate the eigenvectors correlations to resonance level statistics, the axial symmetry between D2D_2 and the spectral compressibility χ\chi is obtained.Comment: 7 pages, 6 figures, accepted by Physical Review

    A toy model of fractal glioma development under RF electric field treatment

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    A toy model for glioma treatment by a radio frequency electric field is suggested. This low-intensity, intermediate-frequency alternating electric field is known as the tumor-treating-field (TTF). In the framework of this model the efficiency of this TTF is estimated, and the interplay between the TTF and the migration-proliferation dichotomy of cancer cells is considered. The model is based on a modification of a comb model for cancer cells, where the migration-proliferation dichotomy becomes naturally apparent. Considering glioma cancer as a fractal dielectric composite of cancer cells and normal tissue cells, a new effective mechanism of glioma treatment is suggested in the form of a giant enhancement of the TTF. This leads to the irreversible electroporation that may be an effective non-invasive method of treating brain cancer.Comment: Submitted for publication in European Physical Journal

    Single-photon Transistors Based on the Interaction of an Emitter and Surface Plasmons

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    A symmetrical approach is suggested (Chang DE et al. Nat Phys 3:807, 2007) to realize a single-photon transistor, where the presence (or absence) of a single incident photon in a ‘gate’ field is sufficient to allow (prevent) the propagation of a subsequent ‘signal’ photon along the nanowire, on condition that the ‘gate’ field is symmetrically incident from both sides of an emitter simultaneously. We present a scheme for single-photon transistors based on the strong emitter-surface-plasmon interaction. In this scheme, coherent absorption of an incoming ‘gate’ photon incident along a nanotip by an emitter located near the tip of the nanotip results in a state flip in the emitter, which controls the subsequent propagation of a ‘signal’ photon in a nanowire perpendicular to the axis of the nanotip

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Metallic nano-cavity lasers at near infrared wavelengths

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    There has been considerable interest in nano-cavity lasers, both from a scientific perspective for investigating fundamental properties of lasers and cavities, and also to produce smaller and better lasers for low-power applications. Light confinement on a wavelength scale has been reported in photonic crystal nano-cavities. Even stronger light confinement can be achieved in metallic cavities which can confine light to volumes with dimensions considerably smaller than the wavelength of light. It was commonly believed, however, that the high losses in metals are prohibitive for laser operation in metallic nano-cavities. Recently we have reported lasing in a metallic nano-cavity filled with an electrically pumped semiconductor. Importantly, the manufacturing approach employed for these devices permits even greater miniaturization of the laser. In particular Metal-Insulator-Metal (MIM) waveguides with dimensions well below the diffraction limit can be fabricated using our techniques. Experimental results from such MIM waveguide lasers will be presented. In theory it is shown that it is possible to reduce the semiconductor gain medium dimensions of these MIM waveguide devices down to a few tens of nanometers in size. Finally, latest results for the fabrication of MIM type waveguide devices will also be examined

    Femtosecond active plasmonics

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    We report that optical illumination of a metal/dielectric plasmonic waveguide can affect the propagation of a surface plasmon polariton signal in the waveguide, thereby enabling direct femtosecond optical modulation of plasmonic signals

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    Not AvailableThis video depicts the 26th Foundation day of NIAP and 20th Dr DN Jha Memorial LectureNot Availabl
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