Because of its compatibility with semiconductor-based technologies, hafnia (HfO) is today's most promising ferroelectric material for applications in electronics. Yet, knowledge on the ferroic and electromechanical response properties of this all-important compound is still lacking. Interestingly, HfO has recently been predicted to display a negative longitudinal piezoelectric effect, which sets it apart from classic ferroelectrics (e.g., perovskite oxides like PbTiO) and is reminiscent of the behavior of some organic compounds. The present work corroborates this behavior, by first-principles calculations and an experimental investigation of HfO thin films using piezoresponse force microscopy. Further, the simulations show how the chemical coordination of the active oxygen atoms is responsible for the negative longitudinal piezoelectric effect. Building on these insights, it is predicted that, by controlling the environment of such active oxygens (e.g., by means of an epitaxial strain), it is possible to change the sign of the piezoelectric response of the material.
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http://dx.doi.org/10.1038/s41467-021-27480-5 | DOI Listing |
Eur J Neurol
January 2025
Department of Neurology, RWTH Aachen University, Aachen, Germany.
Background: Friedreich ataxia is a rare neurodegenerative disorder caused by frataxin deficiency. Both underweight and overweight occur in mitochondrial disorders, each with adverse health outcomes. We investigated the longitudinal evolution of anthropometric abnormalities in Friedreich ataxia and the hypothesis that both weight loss and weight gain are associated with faster disease progression.
View Article and Find Full Text PDFJ Cachexia Sarcopenia Muscle
February 2025
Department of Cardiology, Angiology and Intensive Care Medicine, Deutsches Herzzentrum der Charité, Berlin, Germany.
Background: Despite a phenylalanine (Phe) restrictive diet, most adult patients with 'classical' phenylketonuria (PKU) maintain life-long Phe concentrations above the normal range and receive tyrosine (Tyr) and protein-enriched diets to maintain acceptable concentrations and ensure normal development. While these interventions are highly successful in preventing adverse neuropsychiatric complications, their long- term consequences are incompletely explored. We observed early cardiomyopathic characteristics and associated hemodynamic changes in adult PKU patients and present here the results of a longitudinal evaluation of cardiac phenotype.
View Article and Find Full Text PDFJ Clin Med
January 2025
Hypertension Unit, Division of Clinical Medicine, Department of Medical Sciences, University of Ferrara, 44124 Ferrara, Italy.
An increased renal resistive index (RRI) and proteinuria can predict an estimated glomerular filtration rate (eGFR) decline in patients with chronic kidney disease (CKD) of various causes. This study hypothesized that the RRI and proteinuria interact to determine disease progression in patients with CKDs of unknown origin. : One hundred and fifty six patients (age 76.
View Article and Find Full Text PDFNutrients
January 2025
Nutrition and Mental Health (NUTRISAM) Research Group, Universitat Rovira i Virgili, 43201 Reus, Spain.
Background: The balance of omega-6/omega-3 (-6/-3) is crucial for proper brain function as they have opposite physiological roles.
Objectives: To analyze the association between maternal serum ratios of -6/-3 in the first and third trimesters of pregnancy and the neurodevelopment of their children in the early days after birth in the population of Northern Spain's Mediterranean region.
Methods: Longitudinal study in which 336 mother-child pairs participated.
Nutrients
December 2024
School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, Fudan University, 130 Dong'an Road, Shanghai 200032, China.
Objectives: The coronavirus disease 2019 (COVID-19) pandemic has changed the dietary behavior of college students; however, the persistence of the changes in dietary behavior remains uncertain. This study aims to explore the changes in school food consumption and dietary quality of college students during three distinct COVID-19 periods: pre-epidemic (stage T1), epidemic (stage T2), and post-COVID-19 epidemic (stage T3).
Methods: The persistent 6-year data, involving 3,484,081 dietary records from January 2018 to December 2023, for college students were acquired from the "Intelligent Ordering System (IOS)".
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