Disorder-derived, strong tunneling attenuation in bis-phosphonate monolayers.

Monolayers of alkyl bisphosphonic acids (bisPAs) of various carbon chain lengths (C4, C8, C10, C12) were grown on aluminum oxide (AlO(x)) surfaces from solution. The structural and electrical properties of these self-assembled monolayers (SAMs) were compared with those of alkyl monophosphonic acids (monoPAs). Through contact angle (CA) and Kelvin-probe (KP) measurements, ellipsometry, and infrared (IR) and x-ray photoelectron (XPS) spectroscopies, it was found that bisPAs form monolayers that are relatively disordered compared to their monoPA analogs. Current-voltage (J-V) measurements made with a hanging Hg drop top contact show tunneling to be the prevailing transport mechanism. However, while the monoPAs have an observed decay constant within the typical range for dense monolayers, ß(mono) = 0.85 ± 0.03 per carbon atom, a surprisingly high value, ß(bis) = 1.40 ± 0.05 per carbon atom, was measured for the bisPAs. We attribute this to a strong contribution of 'through-space' tunneling, which derives from conformational disorder in the monolayer due to strong interactions of the distal phosphonic acid groups; they likely form a hydrogen-bonding network that largely determines the molecular layer structure. Since bisPA SAMs attenuate tunnel currents more effectively than do the corresponding monoPA SAMs, they may find future application as gate dielectric modification in organic thin film devices.

Trust and autonomy in end of life: considering the interrelation between patients and their relatives.

PURPOSE OF REVIEW: Patients' autonomy is seen as a major issue in modern medicine but requires the ability to understand and rate an issue without being influenced by others. However, near the end of life, patients often decide considering the consequences for their relatives. RECENT FINDINGS: Our study results and recent literature suggest that existing relational patterns determine experiences, family dynamics, and decision-making processes at the end of life. Relatives as a resource can promote patients' autonomy. In doubt of the patients' judgment or prioritizing their own needs, relatives can undermine patient's autonomy in a paternalistic way. Trust in others should be seen as a reciprocal process. SUMMARY: With respect to the patient's autonomy, healthcare providers need to consider the family structure and its relations.