In planar structures, the vortex resonance frequency changes little as a function of an in-plane magnetic field as long as the vortex state persists. Altering the topography of the element leads to a vastly different dynamic response that arises due to the local vortex core confinement effect. In this work, we studied the magnetic excitations in non-planar ferromagnetic dots using a broadband microwave spectroscopy technique. Two distinct regimes of vortex gyration were detected depending on the vortex core position. The experimental results are in qualitative agreement with micromagnetic simulations.
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http://dx.doi.org/10.1038/srep25196 | DOI Listing |
ACS Photonics
December 2024
Graduate School and Faculty of Information Science and Electrical Engineering, Kyushu University, 744 Motooka Nishi-ku, Fukuoka, 819-0395, Japan.
Whispering-gallery mode (WGM) resonators, renowned for their high Q-factors and narrow line widths, are widely utilized in integrated photonics. Integrating diffraction gratings onto WGM cavities has gained significant attention because these gratings function as azimuthal refractive index modulators, enabling single-mode WGM emissions and supporting beams with orbital angular momentum (OAM). The introduction of curved grating structures facilitates guided mode resonances by coupling high-order diffracted waves with leaking modes from the waveguide.
View Article and Find Full Text PDFMagn Reson Med Sci
December 2024
Department of Radiology, Tianjin Chest Hospital, Tianjin, China.
Purpose: To investigate the potential of 4D flow MRI-derived pulmonary hemodynamic parameters as sensitive markers for chronic obstructive pulmonary disease (COPD) patients with right ventricular dysfunction (RVD).
Methods: We enrolled 15 COPD patients combined with RVD and 43 non-RVD participants, all of them underwent pulmonary function tests, thoracic CT and cardiac MR examinations, and the image post-processing analysis was completed. After comparing the 2 groups, the average flow velocity of the main pulmonary artery (Vavg-MPA) and the right pulmonary artery (Vavg-RPA) were identified as statistically significant confounding factors, propensity score matching was used to pair patients controlling for these 2 parameters.
BMC Cardiovasc Disord
December 2024
Department of Medical and Surgical Sciences, Magna Graecia University, Viale Europa, 1, 88100, Catanzaro, Italy.
There is a growing interest in the potential use of intracardiac fluid dynamic analysis to better understand cardiac mechanics and identify novel imaging biomarkers of cardiovascular disease. Abnormalities of vortex formation and shape may in fact play a critical role in cardiac function, affecting both efficiency and myocardial workload. Recent advances in imaging technologies have significantly improved our ability to analyze these dynamic flow patterns in vivo, offering new insights into both normal and pathological cardiac conditions.
View Article and Find Full Text PDFVasc Specialist Int
December 2024
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
The complex hemodynamic environment within the aortic lumen plays a crucial role in the progression of aortic diseases such as aneurysms and dissections. Traditional imaging modalities often fail to provide comprehensive flow dynamics that are essential for precise risk assessment and timely intervention. The advent of time-resolved, three-dimensional (3D) phase-contrast magnetic resonance imaging (4D flow MRI) has revolutionized the evaluation of aortic diseases by allowing a detailed visualizations of flow patterns and quantification of hemodynamic parameters.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
Department of Science and Engineering of Oxide Materials and Nanomaterials, National University of Science and Technology Politehnica Bucharest, 011061 Bucharest, Romania.
Iron oxide nanoparticles were synthesized using a vortex microfluidic system and subsequently functionalized with a primary shell of salicylic acid, recognized for its ability to increase the stability and biocompatibility of coated materials. In the second stage, the vortex platform was placed in a magnetic field to facilitate the growth and development of a porous silica shell. The selected drug for this study was micafungin, an antifungal agent well regarded for its effectiveness in combating fungal infections and identified as a priority compound by the World Health Organization (WHO).
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