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The voltage margin of a resistor-logic demultiplexer can be improved significantly by basing its connection pattern on a constant-weight code. Each distinct code determines a unique demultiplexer, and therefore a large family of circuits is defined. We consider using these demultiplexers for building nanoscale crossbar memories, and determine the voltage margin of the memory system based on a particular code. We determine a purely code-theoretic criterion for selecting codes that will yield memories with large voltage margins, which is to minimize the ratio of the maximum to the minimum Hamming distance between distinct codewords. For the specific example of a 64 × 64 crossbar, we discuss what codes provide optimal performance for a memory.

Two upper bounds on the photon mass are estimated by means of new conceptual approaches. One of them is found by analyzing the deflection of a massive photon (described by Proca electrodynamics) by an external weak gravitational field. We take as inputs the most recent measurements of the gravitational bending of radio waves by the Sun obtained via the VLBI (very long baseline interferometry). The other one is based on the computation of the anomalous electron magnetic moment in the framework of Proca electrodynamics. The resulting bounds (m grav ∼ 1.7 × 10 −11 MeV, m quant ∼ 1.6 × 10 −10 MeV) are of the same order of magnitude as other existing upper limits, but higher than those recently found.

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Low-energy He-Ne laser (0.5-83 Hz) of changeable frequency specifically increases the resistance of erythrocytes of patients after acute stroke to lipid peroxidation (LPO) induced by hydrogen peroxide. Increase in frequency of illumination increases the efficiency. The same treatment does not affect the LPO process in erythrocytes prepared from healthy donors. Laser beam treatment suggests to provide a reorganization of membrane structure resulting in increase of the antioxidant defense of the cell.