We study focused fields which, for a given total power and a given numerical aperture, have maximum electric field amplitude in some direction in the focal point and are linearly polarized along this direction. It is shown that the optimum field is identical to the image of an electric dipole with unit magnification. In particular, the field which is the image of an electric dipole whose dipole...

We investigate the electric-field-dependent optical properties and electronic behaviors of GaS monolayer by using the first-principles calculations. A reversal of the dipole transition from E//c to E⊥c anisotropy is found with a critical external electric field of about 5 V/nm. Decomposed projected band contributions exhibit asymmetric electronic structures in GaS interlayers under the external...

In the theoretical section of their Letter, the authors claim the result that ‘‘the magnetic current density is minus one half the total current density’’ [1]. In this Comment, I argue that their argument is flawed and their conclusion is invalid. The authors consider an incident plane wave of angular frequency ! that propagates in the z-direction with its electric field linearly polarized alon...

Cell polarity can be influenced by an electric field, but the mechanisms behind this response are poorly understood. A new paper shows that fission yeast cells change their direction of growth in an external electric field and suggests mechanisms based on the cortical pH gradient and on electrophoresis of membrane proteins.

Burkholderia cenocepacia may cause serious infections in patients with cystic fibrosis, and this microorganism can be highly transmissible. Pulsed-field gel electrophoresis is widely used to study the dynamics of strain spread in cystic fibrosis patients. The aim of this work was to perform pulsed-field gel electrophoresis-based molecular typing of B. cenocepacia isolates to evaluate the epidem...

a modified pulsed-field gel electrophoresis (pfge) protocol was developed and applied to clinical isolates of mycobacterium tuberculosis complex to reduce the cost of using lyticase. this protocol reduces the expense of pfge typing of mycobacterium tuberculosis complex as it removes the use of lyticase during the spheroplast formation from these bacteria.