Spectral-Domain Computation of Fields Radiated by Sources in Non-Birefringent Anisotropic Media

We derive the key expressions to robustly address the eigenfunction expansion-based analysis of electromagnetic (EM) fields produced by current sources within planar non-birefringent anisotropic medium (NBAM) layers. In NBAM, the highly symmetric permeability and permittivity tensors can induce directionally-dependent, but polarization independent, propagation properties supporting "degenerate" characteristic polarizations, i.e. four linearly-independent eigenvectors associated with only two (rather than four) unique, non-defective eigenvalues. We first explain problems that can arise when the source(s) specifically reside within NBAM planar layers when using canonical field expressions. To remedy these problems, we exhibit alternative spectral-domain field expressions, immune to such problems, that form the foundation for a robust eigenfunction expansion-based analysis of time-harmonic EM radiation and scattering within such type of planar-layered media. Numerical results demonstrate the high accuracy and stability achievable using this algorithm.Comment: The official (preliminary) published version of this manuscript, along with copyright information, can be found using the provided DOI. IEEE Antennas Wireless Propag. Lett., 201

Decrease in gyrase A protein expression in _E. coli_ cells inhibited by antisense ribozymes

RNase P complexed with external guide sequence (EGS) represents a novel nucleic-acid-based gene interference approach to modulate gene expression. Nucleic acid-based gene interference technologies represent promising strategies for specific inhibition of mRNA sequences of choice. Recently, small interfering RNAs have been implicated in inducing endogenous RNase of the RNA-induced silencing complex in the RNA interference pathway to inhibit gene expression and growth of several human viruses. We report down regulation of protein expression of _E. coli_ gyrase A, an essential gene for DNA supercoiling and antibiotic susceptibility in BL21 (DE3) strain of _E. coli_, using Ribonuclease P based external guide sequence (EGS) technique. EGS directed against gyrase A gene that was cloned into pUC vector, which contains the ampicillin (Amp) resistance gene. The recombinant plasmid pT7EGyrA was transformed into BL21 (DE3) and inductions were performed using IPTG. Western blot was done to investigate the downregulation of gyrase A protein. The results showed a significant decrease of gyrase A suggesting the utility of EGS RNAs in gene therapy applications, by inhibiting the expression of essential proteins