RESUMEN
BACKGROUND: People with schizophrenia have a lower colorectal screening rate than the general population. A previous study reported an intervention using case management to encourage colorectal cancer screening for patients with schizophrenia in psychiatric outpatient settings. In this feasibility study, we developed provider-level implementation strategies and evaluated the feasibility of conducting a definitive trial in terms of the penetration of the intervention assessed at the patient level. Additionally, we examined the fidelity of strategies to implement the intervention at the provider level in a routine clinical psychiatric setting. METHODS: This was a multicenter, single-arm feasibility study with medical staff at psychiatric hospitals in Japan. The provider-level implementation strategies developed in this study included three key elements (organizing an implementation team appointed by the facility director, interactive assistance using a clear guide that outlines who in the hospital should do what, and developing accessible educational materials) to overcome major barriers to implementation of the intervention and four additional elements (progress monitoring, joint meetings and information sharing among participating sites, adaptation of encouragement methods to specific contexts, and education of on-site staff), with reference to the elements identified in the Expert Recommendations for Implementing Change (ERIC). The feasibility of the strategies was evaluated by the proportion of patients who were eligible for encouragement (patients with schizophrenia aged 40, 50, or 60) who received encouragement. We set the goal of providing encouragement to at least 40% of eligible patients at each site. RESULTS: Two public and four private psychiatric hospitals in Okayama and Shimane prefectures participated in this study. Regarding fidelity, all elements of the strategies were conducted as planned. Following the procedures in the guide, each team prepared and provided encouragement according to their own facility and region. Penetration, defined as the proportion of eligible patients who received encouragement, ranged from 33.3 to 100%; five of the six facilities achieved the target proportion. CONCLUSIONS: The provider-level implementation strategies to implement encouragement were feasible in terms of penetration of the intervention assessed at the patient level. The results support the feasibility of proceeding with a future definitive trial of these strategies. TRIAL REGISTRATION: jRCT, jRCT1060220026 . Registered on 06/04/2022.
RESUMEN
Domain walls and topological defects in ferroelectric materials have emerged as a powerful tool for functional electronic devices including memory and logic. Similarly, wall interactions and dynamics underpin a broad range of mesoscale phenomena ranging from giant electromechanical responses to memory effects. Exploring the functionalities of individual domain walls, their interactions, and controlled modifications of the domain structures is crucial for applications and fundamental physical studies. However, the dynamic nature of these features severely limits studies of their local physics since application of local biases or pressures in piezoresponse force microscopy induce wall displacement as a primary response. Here, we introduce an approach for the control and modification of domain structures based on automated experimentation, whereby real-space image-based feedback is used to control the tip bias during ferroelectric switching, allowing for modification routes conditioned on domain states under the tip. This automated experiment approach is demonstrated for the exploration of domain wall dynamics and creation of metastable phases with large electromechanical response.
RESUMEN
Ferroelastic domain switching significantly affects piezoelectric properties in ferroelectric materials. The ferroelastic domain switching and the lattice deformation of both a-domains and c-domains under an applied electric field were investigated using in-situ synchrotron X-ray diffraction in conjunction with a high-speed pulse generator set up for epitaxial (100)/(001)-oriented tetragonal Pb(Zr0.4Ti0.6)O3 (PZT) films grown on (100) c SrRuO3//(100)KTaO3 substrates. The 004 peak (c-domain) position shifts to a lower 2θ angle, which demonstrates the elongation of the c-axis lattice parameter of the c-domain under an applied electric field. In contrast, the 400 peak (a-domain) shifts in the opposite direction (higher angle), thus indicating a decrease in the a-axis lattice parameter of the a-domain. 90° domain switching from (100) to (001) orientations (from a-domain to c-domain) was observed by a change in the intensities of the 400 and 004 diffraction peaks by applying a high-speed pulsed electric field 200 ns in width. This change also accompanied a tilt in the angles of each domain from the substrate surface normal direction. This behaviour proved that the 90° domain switched within 40 ns under a high-speed pulsed electric field. Direct observation of such high-speed switching opens the way to design piezo-MEMS devices for high-frequency operation.
RESUMEN
The ferroelectric domain structure of a PbTiO3 thin film on (100) SrTiO3 has been investigated by transmission electron microscopy (TEM). Two types of a-domain were found: one extended through the film to the surface and another comprised small a-domains confined within the film. Dark-field TEM (DFTEM) observation revealed that 180° domains formed near the substrate and stopped their growth 100 nm away from the substrate. The DFTEM observation also revealed that 90° domain boundaries had head-to-tail structures. To confirm the polarization direction obtained by experiments, diffracted intensities under a two-beam condition were simulated using the extended Darwin-Howie-Whelan equations. On the basis of the obtained results, a ferroelectric domain structure model of PbTiO3 thin films on SrTiO3 is proposed.
RESUMEN
We have studied the strain field around the 90° domains and misfit dislocations in PbTiO3/SrTiO3 (001) epitaxial thin films, at the nanoscale, using the geometric phase analysis (GPA) combined with high-resolution transmission electron microscopy (HRTEM) and high-angle annular dark field--scanning transmission electron microscopy (HAADF-STEM). The films typically contain a combination of a/c-mixed domains and misfit dislocations. The PbTiO3 layer was composed from the two types of the a-domain (90° domain): a typical a/c-mixed domain configuration where a-domains are 20-30 nm wide and nano sized domains with a width of about 3 nm. In the latter case, the nano sized a-domain does not contact the film/substrate interface; it remains far from the interface and stems from the misfit dislocation. Strain maps obtained from the GPA of HRTEM images show the elastic interaction between the a-domain and the dislocations. The normal strain field and lattice rotation match each other between them. Strain maps reveal that the a-domain nucleation takes place at the misfit dislocation. The lattice rotation around the misfit dislocation triggers the nucleation of the a-domain; the normal strains around the misfit dislocation relax the residual strain in a-domain; then, the a-domain growth takes place, accompanying the introduction of the additional dislocation perpendicular to the misfit dislocation and the dissociation of the dislocations into two pairs of partial dislocations with an APB, which is the bottom boundary of the a-domain. The novel mechanism of the nucleation and growth of 90° domain in PbTiO3/SrTiO3 epitaxial system has been proposed based on above the results.