Composite polymer/wax coatings as a corrosion barrier of bioresorbable magnesium coronary stents.

Magnesium and its alloys are suitable materials for biodegradable biomedical implants such as cardiovascular stents. Here we introduce an innovative composite polyelectrolyte multilayer/wax coating applied to commercial coronary Mg-based stents serving as a barrier layer effectively retarding corrosion. This hydrophobic coating, build by layer-by-layer technology, appeared very thin, smooth, homogeneous, strongly adherent and completely covering the surface of the Mg-stent. In-vitro degradation tests showed greater resistance to degradation of coated Mg-stents compared to uncoated and passivated ones. Cytocompatibility studies proved that Mg-stent coated with the composite coating was non-cytotoxic and improved fibroblast cell viability compared to the uncoated Mg-stent.

Perfluoroalkane wax infused gels for effective, regenerating, anti-icing surfaces.

Infusion of solid perfluoroalkanes into polydimethylsiloxane gels provides a simple route to regenerating deicing surfaces, with low adhesion strength from the lower inherent cohesive energy of the perfluoroalkanes. Further, these surfaces are more hydrophobic and environmentally stable than their alkane analogues. The result is a robust, regenerating surface which demonstrates low energy ice adhesion (19.6 kPa), hydrophobicity (water contact angle, CA, >100°), and high environmental stability.

Characterization of the overall rotational diffusion of a protein from 15N relaxation measurements and hydrodynamic calculations.

In this chapter, we discuss experimental and theoretical methods for characterizing the overall rotational diffusion of molecules in solution. The methods are illustrated for the B3 domain of protein G, a small protein with rotational anisotropy of Dpar/Dperp = 1.4. The rotational diffusion tensor of the protein is determined directly from 15N relaxation measurements. The experimental data are treated assuming various possible models for the overall tumbling: isotropic, axially symmetric, and fully anisotropic, and the results of these analyses are compared to determine an adequate diffusion model for the protein. These experimentally derived characteristics of the protein are compared with the results of theoretical calculations of the diffusion tensor using various hydrodynamic models, to find optimal models and parameter sets for theoretical predictions. We also derive model-free characteristics of internal backbone motions in the protein, to show that different models for the overall motion can result in significantly different pictures of motion. This emphasizes the necessity of accurately characterizing the overall tumbling of a molecule to determine its local dynamics.

Improving out-of-hours intravenous fluid prescribing for junior doctors: a prescription label.

Junior doctors are routinely asked to prescribe intravenous fluids (IVF) out-of-hours. Given time constraints and the number of unfamiliar patients, there is uncertainty about their prescription accuracy and safety, particularly in patients who have specific fluid balance requirements. An IVF prescription label was devised for the fluids section of the adult drug chart indicating important patient identifiers and diagnoses such as chronic heart/renal failure. The audit was carried out over a 16 day period, covering three weekends. A qualitative pre- and post-audit questionnaire assessed the confidence of junior doctors in out-of-hours IVF prescribing. All doctors based on the ward during that specific time period were targeted for the post-audit questionnaire. Post-audit, 58% (n=7) saw the label. 86% of those seven doctors stated the label had prompted them to do the following: a) examine the patient b) check blood results and c) urine output. 100% stated that the label improved their confidence in prescribing IVF. In addition, 71% felt the label made them more cautious in prescribing IVF and 43% felt they prescribed less. Overall, all seven (100%) doctors stated that the IVF prescription label was a useful addition to the drug chart. In conclusion, pressurised junior doctors would feel more confident prescribing IVF for unfamiliar patients if crucial information was readily visible on the drug chart. This would improve the accuracy of fluid prescribing and patient safety.