We present ultra-high resolution optical coherence tomography (OCT) structural intensity and optical Doppler tomography (ODT) flow velocity images of the human retina in vivo. The ultra-high speed OCT system is based on Spectral Domain or Fourier Domain technology, which provides a sensitivity advantage over conventional OCT of more than 2 orders of magnitude. This sensitivity improvement allows video rate OCT and ODT cross sectional imaging of retinal structures. Images will be presented with axial resolutions of 6 and 3.5 microns. We observed small features in the inner and outer plexiform layers, which are believed to be small blood vessels. Flow velocity images will be presented showing pulsatile flow in retinal arteries and veins.
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Alzheimers Dement
December 2024
Department of Psychiatry, University of Cologne, Medical Faculty, Cologne, Germany.
Background: Late-life depression (LLD) is a risk factor for Alzheimer's disease (AD) dementia. Previous morphological studies have often associated LLD with atrophy within the medial temporal lobe (MTL), including the hippocampus. A number of previous studies have demonstrated the changes in several MTL subfields in LLD, such as the perirhinal cortex (PrC), cornu ammonis (CA), dentate gyrus (DG), subiculum and entorhinal cortex (EC), but with inconsistent results, which may be explained by the relatively low image resolution of the 3T scanner used in the previous studies.
View Article and Find Full Text PDFUnlabelled: Evaluating tissue microstructure and membrane integrity in the living human brain through diffusion-water exchange imaging is challenging due to requirements for a high signal-to-noise ratio and short diffusion times dictated by relatively fast exchange processes. The goal of this work was to demonstrate the feasibility of imaging of tissue micro-geometries and water exchange within the brain gray matter using the state-of-the-art Connectome 2.0 scanner equipped with an ultra-high-performance gradient system (maximum gradient strength=500 mT/m, maximum slew rate=600 T/m/s).
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, 111 Jiu Long Road, Hefei, 230601, China.
Unipolar barrier architecture is designed to enhance the photodetector's sensitivity by inducing highly asymmetrical barriers, a higher barrier for blocking majority carriers to depressing dark current, and a low minority carrier barrier without impeding the photocurrent flow through the channel. Depressed dark current without block photocurrent is highly desired for uncooled Long-wave infrared (LWIR) photodetection, which can enhance the sensitivity of the photodetector. Here, an excellent unipolar barrier photodetector based on multi-layer (ML) graphene (G) is developed, WSe, and PtSe (G-WSe-PtSe) van der Waals (vdW) heterostructure, in which extremely low dark current of 1.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, China.
Complex-valued neural networks process both amplitude and phase information, in contrast to conventional artificial neural networks, achieving additive capabilities in recognizing phase-sensitive data inherent in wave-related phenomena. The ever-increasing data capacity and network scale place substantial demands on underlying computing hardware. In parallel with the successes and extensive efforts made in electronics, optical neuromorphic hardware is promising to achieve ultra-high computing performances due to its inherent analog architecture and wide bandwidth.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Chemistry, Illinois State University, Normal, IL, 61790-4160, USA.
This work aims to address key issues in the ballistic performance of ceramic-based composite armor, particularly at the joints of spliced bulletproof panels. The edge structure of C/C-SiC ceramic plates and ultra-high molecular weight polyethylene is redesigned to superimpose the joint areas. These structurally optimized composite pads are examined by numerical simulation of impact dynamics to understand their anti-penetration performance whose accuracy is then validated by live fire tests.
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