Nanofibers fabricated using triaxial electrospinning as zero order drug delivery systems

A new strategy for creating functional trilayer nanofibers through triaxial electrospinning is demonstrated. Ethyl cellulose (EC) was used as the filament-forming matrix in the outer, middle, and inner working solutions and was combined with varied contents of the model active ingredient ketoprofen (KET) in the three fluids. Triaxial electrospinning was successfully carried out to generate medicated nanofibers. The resultant nanofibers had diameters of 0.74 ± 0.06 μm, linear morphologies, smooth surfaces, and clear trilayer nanostructures. The KET concentration in each layer gradually increased from the outer to the inner layer. In vitro dissolution tests demonstrated that the nanofibers could provide linear release of KET over 20 h. The protocol reported in this study thus provides a facile approach to creating functional nanofibers with sophisticated structural features.

Nonlinear distortion evaluation of reconfigurable RF circuits in wireless communication systems

A compact highly linear microstrip dual - mode optically switchable filter and a reconfigurable power amplifier are presented. The key characteristics of the dual - mode switchable filter are investigated and described. A second order filter design procedure is outlined to facilitate the realisation of Butterworth and Chebyshev functions. The proposed filter was built and tested with an optical switch, which comprised of a silicon dice acti vated using near infrared light. The measured and simulated results are in good agreement. The measured insertion loss in the ON state was 3.0 dB the isolation in the OFF state was 45 dB at the centre frequency. An evaluation of filter distortion is presen ted for digitally modulated M - QAM and M - QAM OFDM singals.