Floating Electrode Dielectric Barrier Discharge Plasma in Air Promoting Apoptotic Behavior in Melanoma Skin Cancer Cell Lines

Initiation of apoptosis, or programmed cell death, is an important issue in cancer treatment as cancer cells frequently have acquired the ability to block apoptosis and thus are more resistant to chemotherapeutic drugs. Targeted and perhaps selective destruction of cancerous tissue is desirable for many reasons, ranging from the enhancement of or aid to current medical methods to problems currently lacking a solution, i.e., lung cancer. Demonstrated in this publication is the inactivation (killing) of human Melanoma skin cancer cell lines, in vitro, by Floating Electrode Dielectric Barrier Discharge (FE-DBD) plasma. Not only are these cells shown to be killed immediately by high doses of plasma treatment, but low doses are shown to promote apoptotic behavior as detected by TUNEL staining and subsequent flow cytometry. It is shown that plasma acts on the cells directly and not by “poisoning” the solution surrounding the cells, even through a layer of such solution. Potential mechanisms of interaction of plasma with cells are discussed and further steps are proposed to develop an understanding of such systems.     

Lyapunov exponents for one-dimensional cellular automata

Summary In the paper we give a mathematical definition of the left and right Lyapunov exponents for a one-dimensional cellular automaton (CA). We establish an inequality between the Lyapunov exponents and entropies (spatial and temporal).     

Asymptotic Characteristics of the Evolution of Polarization of Nonmonochromatic Radiation in Single-Mode Optical Fibers with Random Twisting of Axes of Linear Birefringence. II. The Asymptotic Behavior of the Degree of Polarization at Large Fiber Lengths

In this paper, we determine the asymptotic behavior for the squared degree of polarization of nonmonochromatic radiation propagating in a large-length fiber with random irregularities. It is found that the average squared degree of polarization tends to zero with the fiber length as the inverse square root of the fiber length.     

A near-field microwave technique for the deep profiling of free carrier concentrations in semiconductors

A technique for the profiling of free carrier concentration N(z) in semiconductors, based on the near-field measurements in microwave frequency range, is proposed. A high accuracy in retrieving the N(z) function with characteristic spatial scales of 10–100 nm using 2–3 probes with apertures of 3–15 μm is demonstrated.     

Whispering vortices

Experiments indicating the excitation of whispering-gallery-type electromagnetic modes by a vortex moving in an annular Josephson junction are reported. At relativistic velocities the Josephson vortex interacts with the modes of the superconducting stripline resonator giving rise to novel resonances on the current-voltage characteristic of the junction. The experimental data are in good agreement with analysis and numerical calculations based on the two-dimensional sine-Gordon model.     

Electrodynamic theory for near-field microwave microscopy of plane-layered structures and its application to metrology of thin dielectric films

A theory for near-field microwave microscopy of plane-layered structures has been developed. The probe of a near-field microscope is considered as electrically small antenna, which emits quasi-static fields and waves in a medium with an arbitrary 1D permittivity profile. The accuracy of the theory has been demonstrated by microscopy of thin dielectric films deposited on a conductive substrate. The possibility of determining film permittivity with an error of 5–7% is shown.     

Method of calculating normal modes in a layered medium with a stream

The spectral properties of the transverse operator in a layered medium with a plane-parallel stream are investigated. The discrete spectrum of this problem differs considerably from the spectrum of the Sturm-Liouville problem. An algorithm for finding normal modes in a layered medium with a stream is proposed.Institute for Physics of Microstructures, Russian Academy of Sciences, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, Nos. 1–2, pp. 110–114, January–February, 1995.     

Approaches for circle characterization in photolithography

The problem of determining the center and radius of a substrate in the shape of a circular disc is considered. We propose an original functional having a clear geometric interpretation. Determination of the extremum of this functional reduces to a linear problem. The matrix of the linear system corresponding to the functional is positively defined and well-posed for rather long arcs. Experimental studies show that the proposed method enables the determination of the center of the substrate with an accuracy of 10 μm, based on a small number of measurements of the coordinates of the substrate edge. This accuracy is sufficient for solving a number of applied problems.     

Asymptotic Characteristics of the Evolution of Polarization of Nonmonochromatic Radiation in Single-Mode Optical Fibers with a Random Twisting of Axes of Linear Birefringence. I. Limiting of Polarization in an Infinitely Long Fiber

We reduce the problem of finding the limiting value of the fiber-ensemble averaged degree of radiation polarization of in an infinitely long optical fiber to the problem of distributions (including joint distributions) of random complex amplitudes E(,z) of the electric field in an optical wave for different wavelengths and the fiber length z tending to infinity. We prove that the random complex vector E(,z) is uniformly distributed on a three-dimensional sphere if z. It is also proved that the random vectors E(₁,z) and E(₂,z) are independent if ₁₂ and z, whence it follows that their joint distribution is entirely determined by the distribution of each of them. The result obtained allows us to find the limiting average values of various quantities describing the radiation upon passing an optical fiber with a random twisting of the anisotropy axes. In particular, on the basis of this result, we show that the average degree of polarization of incoherent radiation upon passing a fiber with such random irregularities tends to zero as the optical-fiber length goes to infinity.     

Simulation of the resistive state of superconducting films in a magnetic field on the basis of the nonstationary ginzburg-landau equation

By numerical simulation of the temporal two-dimensional Ginzburg-Landau equation, we study the resistive state in superconducting bridges with dimensions ξ ≪ d ≪ λ. It is found that the basis of the resistive state here is, as for d ≫ λ, the vortical structures (vortices) whose motion defines the resistive state. It is shown that the motion of vortices is stochastic in a certain range of currents and magnetic fields. We give a classification of possible dynamic and stochastic modes and examine the transitions from the current flow mode, which is observed for large magnetic fields and small transport currents, to the mode of fast phase slippage. The symmetry breaking effect of the resistive state, which results in cross tension with a quadrupole structure, has been detected. Institute of Physics of Microstructures, Russian Academy of Sciences, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenü, Radiofizika, Vol. 40, Nos. 1–2, pp. 213–231, January–February, 1997.