Reliable spatially resolved compositional analysis through atom probe tomography requires an accurate placement of the detected ions within the three-dimensional reconstruction. Unfortunately, for heterogeneous systems, traditional reconstruction protocols are prone to position some ions incorrectly. This stems from the use of simplified projection laws which treat the emitter apex as a spherical cap, although the actual shape may be far more complex. For instance, sampled materials with compositional heterogeneities are known to develop local variations in curvature across the emitter due to their material phase specific evaporation fields. This work provides three pivotal precursors to improve the spatial accuracy of the reconstructed volume in such cases. First, we show scanning probe microscopy enables the determination of the local curvature of heterogeneous emitters, thus providing the essential information for a more advanced reconstruction considering the actual shape. Second, we demonstrate the cyclability between scanning probe characterization and atom probe analysis. This is a key ingredient of more advanced reconstruction protocols whereby the characterization of the emitter topography is executed at multiple stages of the atom probe analysis. Third, we show advances in the development of an electrostatically driven reconstruction protocol which are expected to enable reconstruction based on experimental tip shapes.

Objective. To determine how often requests are made for euthanasia and physician-assisted suicide (EAS) in the absence of severe disease and how such requests are dealt with in medical practice in The Netherlands.

Method. Retrospective interview study. Participants: 125 general practitioners (GPs), 77 nursing home physicians (NHPs), and 208 clinical specialists.

Results. In The Netherlands, each year approximately 400 people request EAS, because they are ‘weary of life’. Thirty per cent of all physicians have at some time received an explicit request for EAS in the absence of severe disease; 3% of all physicians had granted a request for EAS in such a case. Most requests for EAS to GPs in the absence of severe disease (n=29) were made by single people aged 80 years and over. While their problems were most frequently of a social nature, 79% had one or more non-severe illnesses. Most GPs refused the request; half of them proposed an alternative treatment, which the patient often refused. Nineteen people who did not receive any treatment persisted in their wish to die; the request for EAS from 5 out of 10 patients who received one or more types of treatment was withdrawn or became less explicit.

Conclusions. Most physicians in The Netherlands refuse requests for EAS in the absence of severe disease. Most patients persist in their request. In an ageing population more research is needed to provide physicians with practical interventions to prevent suicide and to make life bearable and satisfactory for elderly people who wish to die.