Investigating the influences of the precise manufactured shape of dipole nanoantennas on their optical properties.

Fabrication of small nanoantennas with high aspect ratios via electron beam lithography is at the current technical limit of nanofabrication and hence significant deviations from the intended shape of small nanobars occur. Via numerical simulations, we investigate the influence of geometrical variations of gap nanoantennas, having dimensions on the order of only a few tens of nanometers. We show that those deviations have a significant influence on the performance of such nanoantennas. In particular, their resonance wavelength as well as the magnitude of absorption and scattering cross section and the electric field distribution in the near field is strongly altered. Our findings are thus of importance for applications based on near field as well as those based on far field interactions with nanoantennas and have to be carefully and individually considered in both cases.

[The non-healing wound]. / Diabetischer Fuss, ischämisches Ulkus, Druckgeschwür. So bringen Sie chronische Wunden zum Verschluss.

The most common chronic wounds are pressure ulcers, diabetic ulcers, arterial occlusive disease and venous ulcers. The therapeutic aim after appropriate diagnostic work-up is causal treatment. Pressure relief, revascularisation or compression head the list of potential measures. Apart from local factors such as infection or necrosis, systemic factors such as patient compliance, renal insufficiency and immunosuppression are of relevance. If there is a chance of healing, wound management comprises repeated debridement and wet dressings. In the presence of an infection, local antiseptic treatment is indicated. In the individual case, wound stimulation can be supported by protease inhibitors, growth factors or tissue engineering. Definitive wound closure is achieved by epithelial migration from the margins of the wound, or by plastic surgery. Regular documentation of the course and success of wound healing is mandatory. In the wound care center, surgical disciplines, diabetology, dermatology and diagnostic work-up are coordinated, and liaison with the family doctor and home care providers practiced. This wound healing concept successfully heals approximately 80% of the cases of chronic wounds in 18.8 months (mean healing duration 4.8 months).