We present a systematic 2D spatial-coherence analysis of the soft-X-ray beamline P04 at PETRA III for various beamline configurations. The influence of two different beam-defining apertures on the spatial coherence properties of the beam is discussed and optimal conditions for coherence-based experiments are found. A significant degradation of the spatial coherence in the vertical direction has been measured and sources of this degradation are identified and discussed. The Fourier-analysis method, which gives fast and simple access to the 2D spatial coherence function of the X-ray beam, is used for the experiment. Here, we exploit the charge scattering of a disordered nanodot sample allowing the use of arbitrary X-ray photon energies with this method.
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http://dx.doi.org/10.1364/OE.382608 | DOI Listing |
J Mol Cell Cardiol Plus
March 2024
Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), University Maastricht, Maastricht, the Netherlands.
Introduction: Repetitive focal and rotational activation patterns are currently used as additional ablation targets for atrial fibrillation (AF). However, there is no evidence that all these detected targets are actual sources of AF. In this paper, we present an approach that detects and ranks AF activation patterns not only based on the degree of pattern repetitiveness but also on the extent to which they are able to entrain their vicinity.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Institute of Optical Materials and Technologies, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
Conventional Fourier domain Optical Coherence Tomography (FD-OCT) systems depend on resampling into a wavenumber () domain to extract the depth profile. This either necessitates additional hardware resources or amplifies the existing computational complexity. Moreover, the OCT images also suffer from speckle noise, due to systemic reliance on low-coherence interferometry.
View Article and Find Full Text PDFTransl Vis Sci Technol
December 2024
Department of Biomedical Engineering, University of Houston, Houston, TX, USA.
Purpose: To assess the safety of acoustic radiation force optical coherence elastography in the crystalline lens in situ.
Methods: Acoustic radiation force (ARF) produced by an immersion single-element ultrasound transducer (nominal frequency = 3.5 MHz) was characterized using a needle hydrophone and used for optical coherence elastography (OCE) of the crystalline lens.
Exp Brain Res
January 2025
Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.
This study explores the role of task constraints over muscle synergies expression in the context of upper limb motor impairment after stroke. We recruited nine chronic stroke survivors with upper limb impairments and fifteen healthy controls, who performed a series of tasks designed to evoke muscle synergies through various spatial explorations. These tasks included an isometric force task, a dynamic reaching task, the clinical Fugl-Meyer (FM) assessment, and a pinch task.
View Article and Find Full Text PDFiScience
November 2024
Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
Chronic venous insufficiency (CVI) is a global health concern with significant public health and individual impact. Currently available diagnostic methods cannot visualize microvenous pathologies that have shown to result in severe forms of CVI and also affect the skin. Optical coherence tomography angiography (OCTA) may close the CVI diagnostic gap by providing a fast, label-free, and non-invasive solution to visualize cutaneous microvasculature.
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