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Applications of ferroelectric films critically depend on their polar ordering, which is highly sensitive to the film size and substrate constraint. Previous studies have revealed a much enhanced piezoresponse in ferroelectric nanoislands relaxed from substrate clamping, yet the proposed mechanisms were completely opposite. We revisit this problem utilizing clamped epitaxial and freestanding PbTiO (PTO) films as our model system for systematic investigation via scanning transmission electron microscopy, piezoresponse force microscopy, and second harmonic generation. It is found that freestanding PTO exhibits 97% higher atomic-scale polar displacement compared to the one clamped on the SrAlO/SrTiO (SAO/STO) substrate, with ferroelectric -domains coarsened significantly accompanied by notable polarization rotation and vanishing -domains. These structural changes yield 141% enhancement in the effective piezoelectric coefficient and 404% increase in second harmonic generation intensity for freestanding PTO compared to its epitaxial counterpart clamped by SAO/STO substrate, highlighting the important influence of substrate constraint on ferroelectric films.
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http://dx.doi.org/10.1021/acs.nanolett.5c01925 | DOI Listing |
mBio
September 2025
School of Biological Sciences, University of Auckland, Auckland, New Zealand.
The rotation of the bacterial flagellum is powered by the MotAB stator complex, which converts ion flux into torque. Despite its central role in flagellar function, the evolutionary origin and structural diversity of this system remain poorly understood. Here, we present the first comprehensive phylogenetic and structural characterization of MotAB and its closest non-flagellar homologs.
View Article and Find Full Text PDFAnesth Prog
September 2025
Objective: We aimed to investigate the differences in the lengths and shapes of several preformed nasotracheal tubes (NTTs) among different manufacturers and compare our findings with a previous report.
Methods: Using reference points at the tube tip, the proximal edge of the cuff, and the flexion point, we measured tube lengths for NTTs with inner diameters of 6.5, 7.
ACS Omega
September 2025
Optics and Photonics Group, Institute of Physics, Federal University of Mato Grosso do Sul, PO Box 549, 79070-900 Campo Grande, MS, Brazil.
The production of diesel-biodiesel blends (DBB) aims to mitigate the environmental impacts of diesel combustion. However, gaps remain in understanding their molecular properties, particularly fluorescence anisotropy (FA), which reflects molecular rotation and environmental constraints (e.g.
View Article and Find Full Text PDFSci Technol Adv Mater
September 2025
Research Center for Electronic and Optical Materials, National Institute for Materials Science, Tsukuba, Japan.
The planar and lateral HCl-gas etching behavior of (001) β-GaO under oxygen supply were investigated at partial pressures of (O) = 0-2.5 kPa and 645-1038°C, while maintaining a constant HCl supply partial pressure of (HCl) at 63 Pa. At 747°C, the planar etch rate (PER) exhibited a slight decrease with increasing (O).
View Article and Find Full Text PDFSmall
September 2025
Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, 80303, USA.
Adoptive cell transfers (ACTs) can interact specifically with inflamed tissues, but lack a mechanism for transport through viscous biological barriers such as mucus when administered locally. Further, maintaining cell function is challenging due to the loss of cellular phenotypes in diseased microenvironments. In this work, the use of magnetically controlled helical microrobots is examined to transport macrophages through physiologically representative mucus and maintain functional phenotypes through drug elution for improved cell delivery.
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