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The choriocapillaris (CC) plays an essential role in maintaining the normal functions of the human eye. There is increasing interest in the community to develop an imaging technique for visualizing the CC, yet this remains underexplored due to technical limitations. We propose an approach for the visualization of the CC in humans via a complex signal-based optical microangiography (OMAG) algorithm, based on commercially available spectral domain optical coherence tomography (SD-OCT). We show that the complex signal-based OMAG was superior to both the phase and amplitude signal-based approaches in detailing the vascular lobules previously seen with histological analysis. With this improved ability to visualize the lobular vascular networks, it is possible to identify the feeding arterioles and draining venules around the lobules, which is important in understanding the role of the CC in the pathogenesis of ocular diseases. With built-in FastTrac™ and montage scanning capabilities, we also demonstrate wide-field SD-OCT angiograms of the CC with a field of view at 9×11 mm2.
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http://dx.doi.org/10.1117/1.JBO.22.12.121705 | DOI Listing |
Sensors (Basel)
July 2025
National Time Service Center, Chinese Academy of Sciences, Xi'an 710600, China.
High-frequency (HF) communication is critical for applications such as over-the-horizon positioning and ionospheric detection. However, precise time-delay estimation in complex HF channels faces significant challenges from multipath fading, Doppler shifts, and noise. This paper proposes a Modulation Signal-based Adaptive Time-Delay Estimation (MATE) algorithm, which effectively decouples carrier and modulation signals and integrates phase-locked loop (PLL) and delay-locked loop (DLL) techniques.
View Article and Find Full Text PDFSensors (Basel)
June 2025
College of Communication Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
The existing multi-carrier composite modulation recognition methods have failed to effectively integrate inner and outer modulation characteristics, thereby limiting the potential for improving recognition performance under low signal-to-noise ratio (SNR) conditions. To address this issue, this paper proposes a multi-carrier composite signal modulation recognition algorithm based on a multi-dimensional time-frequency superimposed spectrum (MD-TFSS) with integrated inner and outer features, which can recognize composite modulation signals in the set {BPSK-PM, QPSK-PM, BPSK-QPSK-PM, BPSK-BPSK-PM, QPSK-QPSK-PM}. The proposed method constructs a dual spectrum through multiplying an inner modulation spectrum and a squared spectrum, then combines the inner modulation dual spectrum with the outer modulation time-frequency diagram in dual-channel mode to form MD-TFSS features.
View Article and Find Full Text PDFAMIA Annu Symp Proc
May 2025
Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
Epilepsy affects over 50 million persons worldwide, with less than 50% achieving long-term success following surgery. Traditional electrophysiology signal-based seizure detection methods are resource-intensive, laborious, and overlook multifocal brain interactions. Algebraic topology methods, particularly persistent homology, offer robust representations of complex brain interaction patterns.
View Article and Find Full Text PDFSci Rep
April 2025
Department of Economics, Kardan University, Parwane Du, Kabul, 1001, Afghanistan.
In smart manufacturing, logistics, and other inside settings where the Global Positioning System (GPS) doesn't work, indoor positioning systems (IPS) are essential. Due to environmental complexity, signal noise, and possible data manipulation, traditional IPS techniques struggle with accuracy, resilience, and security. Online and offline phases are distinguished in the suggested indoor location system that employs deep learning and fingerprinting.
View Article and Find Full Text PDFMethods Mol Biol
May 2025
Univ. Grenoble Alpes, INSERM U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 2280 Rue de la Piscine, Domaine Universitaire Gières, Grenoble, France.
AMP-activated protein kinase (AMPK) has evolved to detect a critical increase in cellular AMP/ATP and ADP/ATP concentration ratios as a signal for limiting energy supply. Such energy stress then leads to AMPK activation and downstream events that maintain cellular energy homeostasis. AMPK activation by AMP, ADP, or pharmacological activators involves a conformational switch within the AMPK heterotrimeric complex.
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