Advance care planning for patients with end-stage kidney disease on dialysis: narrative review of the current evidence, and future considerations.

Patients with end-stage kidney disease (ESKD) have a high symptom-burden and high rates of morbidity and mortality. Despite this, evidence has shown that this patient group does not have timely discussions to plan for deterioration and death, and at the end of life there are unmet palliative care needs. Advance care planning is a process that can help patients share their personal values and preferences for their future care and prepare for declining health. Earlier, more integrated and holistic advance care planning has the potential to improve access to care services, communication, and preparedness for future decision-making and changing circumstances. However, there are many barriers to successful implementation of advance care planning in this population. In this narrative review we discuss the current evidence for advance care planning in patients on dialysis, the data around the barriers to advance care planning implementation, and interventions that have been trialled. The review explores whether the concepts and approaches to advance care planning in this population need to be updated to encompass current and future care. It suggests that a shift from a problem-orientated approach to a goal-orientated approach may lead to better engagement, with more patient-centred and satisfying outcomes.

Surface acoustic wave assisted depinning of magnetic domain walls.

We investigate the effects of high frequency strain on the depinning of magnetic domain walls in perpendicular anisotropy materials. Micron wide stripes of [Co(0.3 nm)/Pt(0.6 nm)]5are patterned between a pair of identical inter-digital transducers that generate high frequency (114.8 MHz) standing surface acoustic waves. We use magneto-optical Kerr effect microscopy to characterize the thermally-assisted depinning of domain walls at defect sites within the strips. Our results show that the excitation of the domain walls with surface acoustic waves results in an increase in their depinning probabilities by approximately a factor of 10. Our data are consistent with a model in which the magnetoelastic anisotropies induced by the acoustic waves modulate the energy barriers that pin the domain walls. These results suggest an alternative route to domain wall depinning in thin films and nanostructures and are relevant to the development of racetrack memories, where domain wall pinning can result in reduced velocities and non-deterministic motion.

Spatial mapping of focused surface acoustic waves in the investigation of high frequency strain induced changes.

The field of straintronics, in which strain is used to drive phase transitions, ordering and structural changes, has conventionally been limited to dc or low frequency strain. High frequency large strains, which have the potential to serve as a high frequency trigger of strain sensitive physical phenomena, can be generated using focused surface acoustic waves, which produce two dimensional standing strain waves with very high strain at the elliptical focus. Here, the strain standing wave pattern generated by a focused surface acoustic wave is mapped and quantified as a function of voltage and frequency with high spatial resolution. A knife-edge optical reflection method is used to map the strain standing wave pattern generated by a 87.95 MHz annular interdigital transducer on 128° Y-Cut LiNbO3. Subsequent to strain mapping, ferromagnetic Co/Pt multilayers nanostructures are lithographically patterned within the high strain region for preliminary measurements of magnetization changes arising from high frequency fast strain. The knife edge technique is simple, results in excellent spatial resolution and is fully compatible with other optical measurements, such as focused magneto-optic Kerr measurements, while maintaining spatial information. This ability to accurately and reproducibly determine the position of maximum strain and to lock onto a specific strain region is an important step in the investigation of the effects of high frequency strain on thin film materials, which range from magnetic reorientations to strain induced phase transitions.

Organic ferroelectric evaporator with substrate cooling and in situ transport capabilities.

We report on the design, operation, and performance of a thermal evaporation chamber capable of evaporating organic thin films. Organic thin films are employed in a diverse range of devices and can provide insight into fundamental physical phenomena. However, growing organic thin films is often challenging and requires very specific deposition parameters. The chamber presented here is capable of cooling sample substrates to temperatures below 130 K and allows for the detachment of the sample from the cooling stage and in situ transport. This permits the use of multiple deposition techniques in separate, but connected, deposition chambers without breaking vacuum and therefore provides clean, well characterized interfaces between the organic thin film and any adjoining layers. We also demonstrate a successful thin film deposition of an organic material with a demanding set of deposition parameters, showcasing the success of this design.

Domain size and structure in exchange coupled [Co/Pt]/NiO/[Co/Pt] multilayers.

We investigate the competing effects of interlayer exchange coupling and magnetostatic coupling in the magnetic heterostructure ([Co/Pt]/NiO/[Co/Pt]) with perpendicular magnetic anisotropy (PMA). This particular heterostructure is unique among coupled materials with PMA in directly exhibiting both ferromagnetic and antiferromagnetic coupling, oscillating between the two as a function of spacer layer thickness. By systematically tuning the coupling interactions via a wedge-shaped NiO spacer layer, we explore the energetics that dictate magnetic domain formation using high resolution magnetic force microscopy coupled with the magneto-optical Kerr effect. This technique probes the microscopic and macroscopic magnetic behavior as a continuous function of thickness and the interlayer exchange coupling, including the regions where interlayer coupling goes through zero. We see significant changes in domain structure based on the sign of coupling, and also show that magnetic domain size is directly related to the magnitude of the interlayer exchange coupling energy, which generally dominates over the magnetostatic interactions. When magnetostatic interactions become comparable to the interlayer exchange coupling, a delicate interplay between the differing energy contributions is apparent and energy scales are extracted. The results are of intense interest to the magnetic recording industry and also illustrate a relatively new avenue of undiscovered physics, primarily dealing with the delicate balance of energies in the formation of magnetic domains for coupled systems with PMA, defining limits on domain size as well as the interplay between roughness, domains and magnetic coupling.

Ferroelectric control of magnetic anisotropy.

We demonstrate unambiguous evidence of the electric field control of magnetic anisotropy in a wedge-shaped Co film of varying thickness. A copolymer ferroelectric of 70% vinylidene fluoride with 30% trifluoroethylene, P(VDF-TrFE) overlays the Co wedge, providing a large switchable electric field. As the ferroelectric polarization is switched from up to down, the magnetic anisotropy of the Co films changes by as much as 50%. At the lowest Co thickness the magnetic anisotropy switches from out-of-plane to in-plane as the ferroelectric polarization changes from up to down, enabling us to rotate the magnetization through a large angle at constant magnetic field merely by switching the ferroelectric polarization. The large mismatch in the stiffness coefficients between the polymer ferroelectric and metallic ferromagnet excludes typical magnetoelectric strain coupling; rather, the magnetic changes arise from the large electric field at the ferroelectric/ferromagnet interface.

Oscillatory interlayer exchange coupling and its temperature dependence in [Pt/Co]3/NiO/[Co/Pt]3 multilayers with perpendicular anisotropy.

Interlayer exchange coupling that oscillates between antiferromagnetic and ferromagnetic as a function of NiO thickness has been observed in [Pt(5 A)/Co(4 A)](3)/NiO(t(NiO) A)/[Co(4 A)/Pt(5 A)](3) multilayers with out-of-plane anisotropy. The period of oscillation corresponds to approximately 2 monolayers of NiO. This oscillatory behavior is possibly attributed to the antiferromagnetic ordering in NiO. The antiferromagnetic interlayer exchange coupling for the 11 A NiO layer shows an increase in coupling strength with increasing temperature, in agreement with the quantum interference model of Bruno for insulating spacer layers. A coexistence of exchange biasing and antiferromagnetic interlayer exchange coupling has been observed below T=250 K.

Soft-tissue profile changes concurrent with the orthodontic treatment.

Anthropologists have shown that the external covering made up of integument, adipose tissue, connective tissue, and muscle does not always distribute itself in a uniform, orderly manner. There are great variations in the amount and distribution of these soft-tissue elements. Therefore, a facial profile analysis that is limited to measurements on the hard skeletal structure would not appear to conform to the standards of accuracy if an assessment of the soft-tissue profile were required. The purpose of this investigation is to provide an understanding of the changes which occur in the soft-tissue profile during the orthodontic treatment concurrent with normal growth and development. At the present time, it is not possible to devise a set rule for differentiating a desireable from an undesireable soft-tissue facial profile. However, this should not prohibit the presentation of some reference material as an aid in the diagnosis and practice of orthodontics. In many instances evaluations of facial esthetics seem to be singularly influenced by the orthodontist's concept of a pleasing face. At present, the accomplishment of soft-tissue profile changes by dental movement is limited so it is very important to rely on proper timing of the orthodontic treatment through the pubertal growth period to achieve optimal profile changes.