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Prediction of Retina Damage in Optical Coherence Tomography Image Using Xception Architecture Model

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Prediction of Retina Damage in Optical Coherence Tomography ...

IEEE Eurasia Conference on biomedical engineering, Healthcare and Sustainability (ECBIOS)

作者： Minh Thanh Do Hoang Nhut Huynh Trung Nghia Tran Thuy Linh Hoang Department of Biomedical Engineering Physics Faculty of Applied Science Ho Chi Minh City University of Technology (HCMUT) VNU-HCM Ho Chi Minh City Vietnam Laboratory of Laser Technology Faculty of Applied Science Ho Chi Minh City University of Technology (HCMUT) VNU-HCM Ho Chi Minh City Vietnam Industrial University of Ho Chi Minh City Ho Chi Minh City Vietnam

One of the most vital human organs is the retina. Most of the data is gathered via our eyesight. Thus, maintaining good eye health is crucial for happy and healthy life and eyes. Unfortunately, hazardous eye conditions, including choroidal neovascularization (CNV), Drusen, and diabetic macular edema (DME), directly harm the retina. They are typically discovered late, making it frequently impossible to cure and restore vision. Significant vision loss or even complete blindness may result from this. Ophthalmologists can view the inner structure of the retina using the sophisticated medical imaging technology known as noninvasive retinal optical coherent tomography (OCT), which relies on the visual reflection of the tissues inside the eye. However, in practice, errors continue to occur in diagnosing illnesses in general and eye ailments in particular. Thus, we develop a deep learning model to help physicians diagnose CNV, Drusen, and DME more correctly and lessen medical examination and treatment mistakes. About 8,000 images from the Large Dataset of Labeled Optical Coherence Tomography (OCT) Images were used to train with the Xception's architecture model. The result of this classification study for three types of DME, CNV, and Drusen diseases showed an accuracy of 93%.

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Positronium Lifetime Imaging with the Biograph Vision Quadra using 124I

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arXiv 2025年

作者： Mercolli, Lorenzo Steinberger, William M. Rathod, Narendra Conti, Maurizio Moskal, Pawel Rominger, Axel Seifert, Robert Shi, Kuangyu Stępień, Ewa L. Sari, Hasan Department of Nuclear Medicine Inselspital Bern University Hostpital University of Bern Bern Switzerland ARTORG Center for Biomedical Engineering Research University of Bern Bern Switzerland Siemens Medical Solutions USA Inc. KnoxvilleTN United States Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Krakow Poland Centre for Theranostics Jagiellonian University Krakow Poland Siemens Healthineers International AG Zürich Switzerland

Purpose: Measuring the ortho-positronium (oPs) lifetime in human tissue bears the potential of adding clinically relevant information about the tissue microenvironment to conventional positron emission tomography (PET). Through phantom measurements, we investigate the voxel-wise measurement of oPs lifetime using a commercial long-axial field-of-view (LAFOV) PET scanner. Methods: We prepared four samples with mixtures of Amberlite XAD4, a porous polymeric adsorbent, and water and added between 1.12 MBq and 1.44 MBq of 124I. The samples were scanned in two different setups: once with a couple of centimeters between each sample (15 minutes scan time) and once with all samples taped together (40 minutes scan time). For each scan, we determine the oPs lifetime for the full samples and at the voxel level. The voxel sizes under consideration are 10.03 mm3, 7.13 mm3 and 4.03 mm3. Results: Amberlite XAD4 allows the preparation of samples with distinct oPs lifetime. Using a Bayesian fitting procedure, the oPs lifetimes in the whole samples are 2.52±0.03 ns, 2.37±0.03 ns, 2.27±0.04 ns and 1.82±0.02 ns, respectively. The voxel-wise oPs lifetime fits showed that even with 4.03 mm3 voxels the samples are clearly distinguishable and a central voxels have good count statistics. However, the situation with the samples close together remains challenging with respect to the spatial distinction of regions with different oPs lifetimes. Conclusion: Our study shows that positronium lifetime imaging on a commercial LAFOV PET/CT should be feasible under clinical conditions using 124I. © 2025, CC BY.

关键词： Tissue

Near-Unity Emitting, Widely Tailorable and Stable Exciton Concentrators Built from Doubly Gradient 2D Semiconductor Nanoplatelets

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arXiv 2023年

作者： Liang, Xiao Durmusoglu, Emek G. Lunina, Maria Hernandez-Martinez, Pedro Ludwig Valuckas, Vytautas Yan, Fei Lekina, Yulia Sharma, Vijay Kumar Yin, Tingting Ha, Son Tung Shen, Ze Xiang Sun, Handong Kuznetsov, Arseniy Demir, Hilmi Volkan LUMINOUS Center of Excellence for Semiconductor Lighting and Displays The Photonics Institute School of Electrical and Electronic Engineering Nanyang Technological University Singapore639798 Singapore Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore637371 Singapore Interdisciplinary Graduate Program Nanyang Technological University Singapore637371 Singapore 2 Fusionopolis Way #08-03 Innovis 138634 Singapore UNAM-Institute of Materials Science and Nanotechnology The National Nanotechnology Research Center Department of Electrical and Electronics Engineering Department of Physics Bilkent University Bilkent Ankara06800 Turkey

The strength of electrostatic interactions (EI) between electrons and holes within semiconductor nanocrystals profoundly impact the performance of their optoelectronic systems, and different optoelectronic devices demand distinct EI strength of the active medium. However, achieving a broad range, fine-tuning of the EI strength for specific optoelectronic applications is a daunting challenge, especially in quasi 2-dimensional core-shell semiconductor nanoplatelets (NPLs), as the epitaxial growth of the inorganic shell along the direction of the thickness that solely contributes to the quantum confined effect significantly undermines the strength of the EI. Herein we propose and demonstrate a novel doubly-gradient (DG) core-shell architecture of semiconductor NPLs for on-demand tailoring of the EI strength by controlling the localized exciton concentration via in-plane architectural modulation, demonstrated by a wide tuning of radiative recombination rate and exciton binding energy. Moreover, these exciton-concentration-engineered DG NPLs also exhibit a near-unity quantum yield, remarkable thermal and photo stability, as well as considerably suppressed self-absorption. As proof-of-concept demonstrations, highly efficient color converters and high-performance light-emitting diodes (external quantum efficiency: 16.9%, maximum luminance: 43, 000 cd/m2) have been achieved based on the DG NPLs. This work thus opens up new avenues for developing high-performance colloidal optoelectronic device applications. Copyright © 2023, The Authors. All rights reserved.

关键词： Quantum yield

Solution-Processed and Room-Temperature Spin Light-Emitting Diode Based on Quantum Dots/Chiral Metal-Organic Framework Heterostructure

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Advanced Functional Materials 2023年第19期33卷

作者： Mustaqeem, Mujahid Chou, Pi-Tai Kamal, Saqib Ahmad, Naveed Lin, Jia-Yu Lu, Yu-Jung Lee, Xing-Hao Lin, Kung-Hsuan Lu, Kuang-Lieh Chen, Yang-Fang Nano-Science and Technology Program Taiwan International Graduate Program Institute of Physics Academia Sinica Taipei106 Taiwan Department of Physics National Taiwan University No. 1 Section 4 Roosevelt Rd Taipei10617 Taiwan Department of Chemistry National Taiwan University No. 1 Section 4 Roosevelt Rd Taipei10617 Taiwan Institute of Chemistry Academia Sinica Taipei115 Taiwan Department of Materials Science and Engineering National Taiwan University of Science and Technology Taipei10607 Taiwan Research Center for Applied Sciences Academia Sinica Taipei115024 Taiwan Institute of Physics Academia Sinica Taipei11529 Taiwan

Spin optoelectronics is an indispensable key for the future development of spintronics. In conventional spin light emitting diodes (LEDs), spin-polarized carrier pairs are injected electrically into the light emitting layer and create circularly polarized light (CPL). Generally, spin-polarized carriers are accomplished using ferromagnetic contacts or applying an external magnetic field, which will produce several drawbacks, including low temperature operation, low spin-polarized carriers injection efficiency, etc. To circumvent the existing shortcomings, here, an alternative approach is proposed and achieves spin-polarized LEDs at room temperature based on quantum dots (QDs)/chiral metal-organic framework heterojunction without using ferromagnetic contacts or magnetic fields. The spin-polarized injected layer composed of self-assembled monolayer (SAM)/Chiral-MOF ([Sr(9,10-adc)(DMAc)2]n)) film, which produces spin-polarized holes with spin orientation, determining the polarization and strength of circularly polarized electroluminescence (CP-EL). The spin-QLED emits CP-EL at a rate of 12.24% efficiency, which provides an excellent alternative to generate new functionality for conventional QLEDs. The approach is anticipated to be very useful, enabling to offer a general methodology for generating not yet realized spin optoelectronic devices. © 2023 Wiley-VCH GmbH.

关键词： Room temperature

Electric Fields Near Undulating Dielectric Membranes

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arXiv 2023年

作者： Pogharian, Nicholas dos Santos, Alexandre P. Ehlen, Ali de la Cruz, Monica Olvera Department of Materials Science and Engineering Northwestern University EvanstonIL60208 United States Instituto de Física Universidade Federal do Rio Grande do Sul RS Porto Alegre91501-970 Brazil Applied Physics Program Northwestern University EvanstonIL60208 United States Department of Physics and Astronomy Northwestern University EvanstonIL60208 United States Department of Chemistry Northwestern University EvanstonIL60208 United States Department of Chemical and Biological Engineering Northwestern University EvanstonIL60208 United States

Dielectric interfaces are crucial to the behavior of charged membranes, from graphene to synthetic and biological lipid bilayers. Understanding electrolyte behavior near these interfaces remains a challenge, especially in the case of rough dielectric surfaces. A lack of analytical solutions consigns this problem to numerical treatments. We report an analytic method for determining electrostatic potentials near curved dielectric membranes in a two-dimensional periodic’slab’ geometry using a periodic summation of Green’s functions. This method is amenable to simulating arbitrary groups of charges near surfaces with two-dimensional deformations. We concentrate on one-dimensional undulations. We show that increasing membrane undulation increases the asymmetry of interfacial charge distributions due to preferential ionic repulsion from troughs. In the limit of thick membranes we recover results mimicking those for electrolytes near a single interface. Our work demonstrates that rough surfaces generate charge patterns in electrolytes of charged molecules or mixed-valence ions. Copyright © 2023, The Authors. All rights reserved.

关键词： Electrolytes

The effect of loops on the mean square displacement of Rouse-model chromatin

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arXiv 2023年

作者： Yuan, Tianyu Yan, Hao Bailey, Mary Lou P. Williams, Jessica F. Surovtsev, Ivan King, Megan C. Mochrie, Simon G.J. Integrated Graduate Program in Physical and Engineering Biology Yale University New HavenCT06520 United States Department of Physics Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States Department of Cell Biology Yale School of Medicine New HavenCT06520 United States Department of Molecular Cell and Developmental Biology Yale University New HavenCT06511 United States

Chromatin exhibits polymer properties and its dynamics are now commonly described using the classical Rouse model. The subsequent discovery, however, of intermediate scale chromatin organization known as topologically associating domains (TADs) in experimental Hi-C contact maps for chromosomes across the tree of life, together with the proposed loop extrusion factor (LEF) model that aims to explain TAD formation, motivates efforts to understand the effect of loops and loop extrusion on chromatin dynamics. This paper seeks to fulfill this need by combining LEF-model simulations with extended Rouse-model polymer simulations to investigate the dynamics of chromatin with loops and dynamic loop extrusion. Specifically, we extend the classical Rouse model by modifying the polymer's dynamical matrix to incorporate extra springs that represent loop bases. We also theoretically generalize the friction coefficient matrix so that the Rouse beads with nonuniform friction coefficients are compatible with our Rouse model simulation method. We show that loops significantly suppress the averaged mean square displacement (MSD) of a gene locus, consistent with recent experiments that track fluorescently-labelled chromatin loci. We also find that loops reduce the MSD's stretching exponent from the classical Rouse-model value of 1/2 to a loop-density-dependent value in the 0.45-0.40 range. Remarkably, stretching exponent values in this range have also been observed in recent experiments [S. C. Weber, A. J. Spakowitz, and J. A. Theriot, Phys. Rev. Lett. 104, 238102 (2010) and M. L. P. Bailey, I. Surovtsev, J. F. Williams, H. Yan, T. Yuan, S. G. Mochrie, and M. C. King, Mol. Biol. Cell (in press)]. We also show that for a wide range of plausible loop-extrusion parameters, the dynamics of loop extrusion itself negligibly affects chromatin mobility. By studying a static "rosette" loop configuration, we also demonstrate that chromatin MSDs and stretching exponents depend on the location of

关键词： Extrusion

Ultrastrong Spin-Photon Coupling in Gadolinium Gallium Garnet

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Ultrastrong Spin-Photon Coupling in Gadolinium Gallium Garne...

Conference on Lasers and Electro-Optics (CLEO)

作者： T. Elijah Kritzell Junzhe Bao Jacques Doumani Jae Joon Lee Hongjing Xu Fuyang Tay Hiroyuki Nojiri Motoaki Bamba Andrey Baydin Junichiro Kono Department of Electrical and Computer Engineering Rice University Houston Texas USA Applied Physics Graduate Program Smalley-Curl Institute Rice University Houston Texas USA Department of Physics and Astronomy Rice University Houston Texas USA Institute for Materials Research Tohoku University Senai Japan The Hakubi Center for Advanced Research Kyoto University Kyoto Japan Department of Physics I Kyoto University Kyoto Japan Smalley-Curl Institute Rice University Houston Texas USA Department of Material Science and NanoEngineering Rice University Houston Texas USA

We examine ultrastrong coupling of an ensemble of paramagnetic spins in Gd 3 Ga 5 O 12 with terahertz photons in the presence of a high external magnetic field both in the bulk and thin-film limits.

ISBN: (纸本)9781957171258

We examine ultrastrong coupling of an ensemble of paramagnetic spins in Gd 3 Ga 5 O 12 with terahertz photons in the presence of a high external magnetic field both in the bulk and thin-film limits.

关键词： CCD cameras Condensed matter Magnetic fields Photons Quantum optics Terahertz spectroscopy

Regimes of stratified turbulence at low Prandtl number

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arXiv 2023年

作者： Shah, Kasturi Chini, Gregory P. Caulfield, Colm-Cille P. Garaud, Pascale Department of Applied Mathematics and Theoretical Physics University of Cambridge CambridgeCB3 0WA United Kingdom Department of Earth Atmospheric and Planetary Sciences Massachusetts Institute of Technology CambridgeMA02139 United States Program in Integrated Applied Mathematics University of New Hampshire DurhamNH03824 United States Department of Mechanical Engineering University of New Hampshire DurhamNH03824 United States Institute for Energy and Environmental Flows University of Cambridge CambridgeCB3 0EZ United Kingdom Department of Applied Mathematics Baskin School of Engineering University of California Santa Cruz Santa CruzCA95064 United States

Quantifying transport by strongly stratified turbulence in low Prandtl number (Pr) fluids is critically important for the development of better models for the structure and evolution of stellar and planetary interiors. Motivated by recent numerical simulations showing strongly anisotropic flows suggestive of scale-separated dynamics, we perform a multiscale asymptotic analysis of the governing equations. We find that, in all cases, the resulting slow-fast systems take a quasilinear form. Our analysis also reveals the existence of several distinct dynamical regimes depending on the emergent buoyancy Reynolds and Péclet numbers, Reb = α2Re and Peb = PrReb, respectively, where α is the aspect ratio of the large-scale turbulent flow structures, and Re is the outer scale Reynolds number. Scaling relationships relating the aspect ratio, the characteristic vertical velocity, and the strength of the stratification (measured by the Froude number Fr) naturally emerge from the analysis. When Peb α, the dynamics at all scales is dominated by buoyancy diffusion, and our results recover the scaling laws empirically obtained from direct numerical simulations by Cope et al. (2020). For Peb ≥ O(1), diffusion is negligible (or at least subdominant) at all scales and our results are consistent with those of Chini et al. (2022) for strongly stratified geophysical turbulence at Pr = O(1). Finally, we have identified a new regime for α Peb 1, in which slow, large scales are diffusive while fast, small scales are not. We conclude by presenting a map of parameter space that clearly indicates the transitions between isotropic turbulence, non-diffusive stratified turbulence, diffusive stratified turbulence and viscously-dominated flows, and by proposing parameterisations of the buoyancy flux, mixing efficiency and turbulent diffusion coefficient for each regime. © 2023, CC BY.

关键词： Buoyancy

Weakly-Supervised Semantic Segmentation of Circular-Scan, Synthetic-Aperture-Sonar Imagery

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arXiv 2024年

作者： Sledge, Isaac J. Byrne, Dominic M. King, Jonathan L. Ostertag, Steven H. Woods, Denton L. Prater, James L. Kennedy, Jermaine L. Marston, Timothy M. Príncipe, José C. The Advanced Signal Processing and Automated Target Recognition Branch Naval Surface Warfare Center Panama CityFL United States The Naval Sea Systems Command United States The Applied Sensing and Processing Branch Naval Surface Warfare Center Panama CityFL United States The Littoral Acoustics and Target Physics Branch Naval Surface Warfare Center Panama CityFL United States The Division Head of the Sensing Sciences and Systems Division Naval Surface Warfare Center Panama CityFL United States The Applied Physics Laboratory University of Washington SeattleWA United States The Department of Electrical and Computer Engineering The Department of Biomedical Engineering University of Florida GainesvilleFL United States The University of Florida United States

We propose a weakly-supervised framework for the semantic segmentation of circular-scan synthetic-aperture-sonar (CSAS) imagery. The first part of our framework is trained in a supervised manner, on image-level labels, to uncover a set of semi-sparse, spatially-discriminative regions in each image. The classification uncertainty of each region is then evaluated. Those areas with the lowest uncertainties are then chosen to be weakly labeled segmentation seeds, at the pixel level, for the second part of the framework. Each of the seed extents are progressively resized according to an unsupervised, information-theoretic loss with structured-prediction regularizers. This reshaping process uses multi-scale, adaptively-weighted features to delineate class-specific transitions in local image content. Content-addressable memories are inserted at various parts of our framework so that it can leverage features from previously seen images to improve segmentation performance for related images. We evaluate our weakly-supervised framework using real-world CSAS imagery that contains over ten seafloor classes and ten target classes. We show that our framework performs comparably to nine fully-supervised deep networks. Our framework also outperforms eleven of the best weakly-supervised deep networks. We achieve state-of-the-art performance when pre-training on natural imagery. The average absolute performance gap to the next-best weakly-supervised network is well over ten percent for both natural imagery and sonar imagery. This gap is found to be statistically significant. © 2024, CC BY.

关键词： Semantic Segmentation