We present a new electromagnetic mode that forms at the interface between two planar surfaces laid side by side in free space, effectively guiding energy along an infinitesimal, one-dimensional line. It is shown that this mode occurs when the boundaries have complementary surface impedances, and it is possible to control the mode confinement by altering their values correspondingly. The mode exhibits singular field enhancement, broad bandwidth, direction-dependent polarization, and robustness to certain defects. As a proof of concept, experimental results in the microwave regime are provided using patterned conducting sheets. Our proposed effective-medium-based approach is general, however, thus allowing for potential implementation up to optical frequencies. Our system is promising for applications including integrated photonics, sensing, switching, chiral quantum coupling, and reconfigurable waveguides.
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http://dx.doi.org/10.1103/PhysRevLett.119.106802 | DOI Listing |
Ultrasound Med Biol
January 2025
Echosens, Paris, France.
Objective: Although FibroScan (FS), based on Vibration-Controlled Transient Elastography (VCTE), is a widely used non-invasive device for assessing liver fibrosis and steatosis, its current standard-VCTE examination remains timely and difficult on patients with obesity. The Guided-VCTE examination uses continuous shear waves to locate the liver by providing a real-time predictive indicator for shear wave propagation and uses shear wave maps averaging to increase the signal-to-noise ratio in difficult to assess patients. We aimed to evaluate the effectiveness of the new indicator, as well as compare examination times and success rates with both standard-VCTE and Guided-VCTE examinations.
View Article and Find Full Text PDFNeurology
January 2025
Department of Neurology, Massachusetts General Hospital, Boston.
Background And Objectives: Rolandic epilepsy (RE), the most common childhood focal epilepsy syndrome, is characterized by a transient period of sleep-activated epileptiform activity in the centrotemporal regions and variable cognitive deficits. Sleep spindles are prominent thalamocortical brain oscillations during sleep that have been mechanistically linked to sleep-dependent memory consolidation in animal models and healthy controls. Sleep spindles are decreased in RE and related sleep-activated epileptic encephalopathies.
View Article and Find Full Text PDFJ Cell Mol Med
January 2025
Ataturk Vocational School of Health Services, Department of Medical Laboratory Techniques, Afyonkarahisar Health Sciences University, Afyonkarahisar, Turkey.
The development and progression of osteoarthritis (OA) are believed to involve inflammation. This study aimed to investigate the effects of applying therapeutic ultrasound (US) to human osteoarthritic chondrocytes in continuous and pulsed modes on cell proliferation and proinflammatory cytokine levels. Human osteoarthritic chondrocytes (HC-OA 402OA-05a) were proliferated in appropriate media and then seeded into culture plates.
View Article and Find Full Text PDFClin Trials
January 2025
Department of Medical Social Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Background: Implementation and hybrid effectiveness-implementation trials aspire to speed the translation of science into practice by generating crucial evidence for improving the uptake of effective health interventions. By design, they pose unique recruitment and retention challenges due to their aims, units of analysis, and sampling plans, which typically require many clinical sites (i.e.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Institute of Fundamental Technological Research, Polish Academy of Sciences, ul. Pawińskiego 5B, 02-106 Warsaw, Poland.
In this paper, we demonstrate that torsional surface elastic waves can propagate along the curved surface of a metamaterial elastic rod (cylinder) embedded in a conventional elastic medium. The crucial parameter of the metamaterial rod is its elastic compliance s44(1)ω, which varies as a function of frequency ω analogously to the dielectric function εω in Drude's model of metals. As a consequence, the elastic compliance s44(1)ω can take negative values s44(1)ω<0 as a function of frequency ω.
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