Barium alginate capsules for 3D immobilisation of living cells: morphology, membrane properties and permeability

Encapsulation in a barium alginate membrane is a promising strategy to obtain a three dimensional culture of living cells: membrane properties are crucial for a realistic clinical application. A one-step encapsulation technique, recently developed for controlled release of boar semen, was employed to prepare barium alginate and protamine-alginate membranes: permeability to two model molecules (haemoglobin and glucose) was evaluated. Capsules were evaluated for technological properties and scanning electron microscopy was used to examine the external morphology of the capsules and the 3D distribution of the cells within the core. The results indicate that 3D arrangement and cell shape are maintained, capsule dimensions and mechanical properties can be modulated, as well as their permeability to model molecules such as haemoglobin and glucose

Characterization of the indoor-to-outdoor wireless channel in air-to-ground communication systems

Wireless communication between User Terminals (UTs) inside a building and an outdoor base station mounted onboard an unmanned aerial vehicle (UAV) is receiving a higher interest in emergency management scenarios and where users require on demand high throughput services. In such applications, a fundamental aspect is the thorough characterization of the propagation environment through parameters such as the UTUAV distance and the number of walls and floors crossed. In this paper, we characterize the indoor-to-outdoor wireless channel by using a commercial ray-tracing software. The reference scenario is a four-floor building. The UTs are uniformly distributed within each floor and two UAV positions are considered nearby the building. As a main contribution, we present numerical results in terms of path loss against the UT-UAV distance. The dependence of the path loss on the number of floors between the UT and the UAV is highlighted as well. Finally, the ray-tracing results are compared with those predicted by a few available propagation models