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Angewandte Chemie International Edition 2024年第48期63卷

作者： Vijay K. Velisoju Enrique V. Ramos-Fernández Rajesh Kancherla Rafia Ahmad Kuntal Pal Hend Mohamed Jose L. Cerrillo Mark J. Meijerink Luigi Cavallo Magnus Rueping Pedro Castaño Multiscale Reaction Engineering KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia KAUST Catalysis Center (KCC) King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Laboratorio de Materiales Avanzados Departamento de Química Inorgánica—Instituto Universitario de Materiales de Alicante Universidad de Alicante Apartado 99 E-03080 Alicante Spain Chemical Engineering Program Physical Science and Engineering (PSE) Division KAUST Thuwal 23955-6900 Saudi Arabia

Titelbild: Highly Dispersed Pd@ZIF-8 for Photo-Assisted Cross-Couplings and CO2to Methanol: Activity and Selectivity Insights (Angew. Chem. 48/2024)

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Angewandte Chemie 2024年第48期136卷

Highly Dispersed Pd@ZIF-8 for Photo-Assisted Cross-Couplings and CO2to Methanol: Activity and Selectivity Insights

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Angewandte Chemie 2024年第48期136卷

Our study unveils a pioneering methodology that effectively distributes Pd species within a zeolitic imidazolate framework-8 (ZIF-8). We demonstrate that Pd can be encapsulated within ZIF-8 as atomically dispersed Pd species that function as an excited-state transition metal catalyst for promoting carbon–carbon (C−C) cross-couplings at room temperature using visible light as the driving force. Furthermore, the same material can be reduced at 250 °C, forming Pd metal nanoparticles encapsulated in ZIF-8. This catalyst shows high rates and selectivity for carbon dioxide hydrogenation to methanol under industrially relevant conditions (250 °C, 50 bar): 7.46 mol methanol mol metal −1 h −1 and >99 %. Our results demonstrate the correlations of the catalyst structure with the performances at experimental and theoretical levels.

关键词： Pd@ZIF-8 CO2 hydrogenation Alkyl halide Excited-state Palladium Cross-coupling

Quantum enhanced electric field mapping within semiconductor devices

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arXiv 2024年

作者： Scheller, D. Hrunski, F. Schwarberg, J.H. Knolle, W. Soykal, Ö.O. Udvarhelyi, P. Narang, P. Weber, H.B. Hollendonner, M. Nagy, R. Insitute of Applied Quantum Technologies Friedrich-Alexander-University Erlangen-Nürnberg Erlangen91052 Germany Chair of Electron Devices Friedrich-Alexander-University Erlangen-Nürnberg Erlangen91058 Germany Leipzig04318 Germany Photonic Inc. CoquitlamBCV3K 6T1 Canada Department of Chemistry and Biochemistry University of California Los AngelesCA90095 United States Division of Physical Sciences College of Letters and Science University of California Los AngelesCA90095 United States Department of Electrical and Computer Engineering University of California Los AngelesCA90095 United States Chair of Applied Physics Friedrich-Alexander-University Erlangen-Nürnberg Erlangen91058 Germany

Semiconductor components based on silicon carbide (SiC) are a key component for high-power electronics. Their behavior is determined by the interplay of charges and electric fields, which is typically described by modeling and simulations that are calibrated by nonlocal electric properties. So far, there are no experimental methods that allow for the 3D mapping of both the electric field and the concentrations of free charge carriers inside an electronic device. To fulfill this information gap, we propose an operando method that utilizes single silicon vacancy (VSi) centers in 4H-SiC. The VSi centers are at various positions in the intrinsic region of a pin-diode. To monitor the local static electric field, we perform Stark shift measurements based on photoluminescence excitation (PLE), which allows us to infer the expansion of the depletion zone and therefore to determine the local concentration of dopants. Besides this, we show that our measurements allow us to additionally obtain the local concentration of free charge carriers. The method presented here therefore paves the way for a new quantum-enhanced electronic device technology, capable of mapping the interplay of mobile charges and electric fields in a working semiconductor device with nanometer precision. Copyright © 2024, The Authors. All rights reserved.

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Measuring hand use in the home after cervical spinal cord injury using egocentric video

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arXiv 2022年

作者： Bandini, Andrea Dousty, Mehdy Hitzig, Sander L. Craven, B. Catharine Kalsi-Ryan, Sukhvinder Zariffa, José KITE Research Institute Toronto Rehabilitation Institute University Health Network Canada The BioRobotics Institute Scuola Superiore Sant'Anna Pisa Italy Department of Excellence in Robotics and AI Scuola Superiore Sant'Anna Pisa Italy Institute of Biomedical Engineering University of Toronto TorontoON Canada Rehabilitation Sciences Institute Temerty Faculty of Medicine University of Toronto TorontoON Canada St. John's Rehab Research Program Sunnybrook Research Institute Sunnybrook Health Sciences Centre TorontoON Canada Department of Occupational Science & Occupational Therapy Temerty Faculty of Medicine University of Toronto TorontoON Canada Brain and Spinal Cord Rehabilitation Program Toronto Rehabilitation Institute University Health Network TorontoON Canada Division of Physical Medicine and Rehabilitation Department of Medicine Temerty Faculty of Medicine University of Toronto TorontoON Canada Department of Physical Therapy University of Toronto TorontoON Canada Edward S. Rogers Sr. Department of Electrical and Computer Engineering University of Toronto TorontoON Canada

Egocentric video has recently emerged as a potential solution for monitoring hand function in individuals living with tetraplegia in the community, especially for its ability to detect functional use in the home environment. The aim of this study was to develop and validate a wearable vision-based system for measuring hand use in the home among individuals living with tetraplegia. Several deep learning algorithms for detecting functional hand-object interactions were developed and compared. The most accurate algorithm was used to extract measures of hand function from 65 hours of unscripted video recorded at home by 20 participants with tetraplegia. These measures were: the percentage of interaction time over total recording time (Perc);the average duration of individual interactions (Dur);the number of interactions per hour (Num). To demonstrate the clinical validity of the technology, egocentric measures were correlated with validated clinical assessments of hand function and independence (Graded Redefined Assessment of Strength, Sensibility and Prehension - GRASSP, Upper Extremity Motor Score - UEMS, and Spinal Cord Independent Measure - SCIM). Hand-object interactions were automatically detected with a median F1-score of 0.80 (0.67-0.87). Our results demonstrated that higher UEMS and better prehension were related to greater time spent interacting, whereas higher SCIM and better hand sensation resulted in a higher number of interactions performed during the egocentric video recordings. For the first time, measures of hand function automatically estimated in an unconstrained environment in individuals with tetraplegia have been validated against internationally accepted measures of hand function. Future work will necessitate a formal evaluation of the reliability and responsiveness of the egocentric-based performance measures for hand use. © 2022, CC BY-NC-ND.

关键词： Video recording

Deep Automatic Alignment of Mpox Dermatological Hand Photography

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Deep Automatic Alignment of Mpox Dermatological Hand Photogr...

IEEE International Symposium on Biomedical Imaging

作者： Bohan Jiang Andrew McNeil Yihao Liu Gaurav Rudravaram Inga Saknite Placide Mbala-Kingebeni Olivier Tshiani Mbaya Tyra Silaphet Rachel Weiss Lori E. Dodd Veronique Nussenblatt Daniel Moyer Bennett A. Landman Benoit M. Dawant Eric R. Tkaczyk Department of Electrical and Computer Engineering Vanderbilt University Nashville TN USA Department of Dermatology Vanderbilt University Medical Center Nashville TN USA Department of Veterans Affairs Dermatology Service and Research Service Nashville TN USA Biophotonics Laboratory University of Latvia Riga Latvia Institut National de Recherche Biomedicale Kinshasa Democratic Republic of the Congo Clinical Monitoring Research Program Directorate Frederick National Laboratory for Cancer Research Frederick MD USA Clinical Trials Research Section Division of Clinical Research National Institute of Allergy and Infectious Disease Bethesda MD USA Laboratory of Clinical Immunology and Microbiology National Institute of Allergy and Infectious Diseases Bethesda MD USA Department of Computer Science Vanderbilt University Nashville TN USA

ISBN: (数字)9798331520526

ISBN: (纸本)9798331520533

Mpox is a viral illness with heavy cutaneous involvement. Automatic tracking of mpox lesion progression is critical in determining the resolution of evolving lesions. This work introduces a novel application of deep learning for lesion monitoring through alignment of dermatological hand photographs. By adapting the VoxelMorph framework for 2D photographic data, we explore key point alignment across serial images. We trained our neural network model on a unique dataset of 1,658 hand images and evaluated its performance on a test set of 254 images. Additionally, we validated the method's generalizability with a supplementary set of 500 images, which included extensive Mpox infection. Our findings indicate modest yet significant improvements in key points and lesion center registration across different regularization strengths. Although promising, the complexity of hand structure presents challenges, requiring cautious application and further refinement, especially in regions with intense spatial discontinuities, such as interdigital areas.

关键词： Hands Photography Deep learning Training Three-dimensional displays Image resolution Neural networks Parametric statistics Lesions Monitoring

Functional neuroplasticity of facilitation and interference effects on inhibitory control following 3-month physical exercise in aging

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Scientific Reports 2024年第1期14卷 1-13页

作者： Wu, Hong-Yi Huang, Chih-Mao Hsu, Ai-Ling Chen, Chiao-Nan Wu, Changwei W. Chen, Jyh-Horng Graduate Institute of Biomedical Electronics and Bioinformatics National Taiwan University Taipei Taiwan Department of Biological Science and Technology National Yang Ming Chiao Tung University Hsinchu Taiwan Bachelor Program in Artificial Intelligence Chang Gung University Taoyuan Taiwan Department of Psychiatry Chang Gung Memorial Hospital at Linkou Taoyuan Taiwan Department of Physical Therapy and Assistive Technology National Yang Ming Chiao Tung University Taipei Taiwan Graduate Institute of Mind Brain and Consciousness Taipei Medical University New Taipei Taiwan Research Center of Sleep Medicine Taipei Medical University Hospital Taipei Taiwan Department of Electrical Engineering National Taiwan University Taipei Taiwan

Preservation of executive function, like inhibition, closely links to the quality of life in senior adults. Although neuroimaging literature has shown enhanced inhibitory function followed by aerobic exercise, current evidence implies inconsistent neuroplasticity patterns along different time durations of exercise. Hence, we conducted a 12-week exercise intervention on 12 young and 14 senior volunteers and repeatedly measured the inhibitory functionality of distinct aspects (facilitation and interference effects) using the numerical Stroop task and functional Magnetic Resonance Imaging. Results showcased improved accuracy and reduced reaction times (RT) after 12-week exercise, attributed to frontoparietal and default mode network effects. In young adults, the first phase (0 to six weeks) exercise increased the activation of the right superior medial frontal gyrus, associated with reduced RT in interference, but in the second intervention phase (six to twelve weeks), the decreased activation of the left superior medial frontal gyrus positively correlated with reduced RT in facilitation. In senior adults, the first six-week intervention led to reduced activations of the inferior frontal gyrus, inferior parietal gyrus, and default mode network regions, associated with the reduced RT in interference. Still, in the second intervention phase, only the visual area exhibited increased activity, associated with reduced RT in interference. Except for the distinctive brain plasticity between the two phases of exercise intervention, the between-group comparison also presented that the old group gained more cognitive benefits within the first six weeks of exercise intervention;however, the cognitive improvements in the young group occurred after six weeks of intervention. Limited by the sample size, these preliminary findings corroborated the benefits of aerobic exercise on the inhibitory functions, implying an age × exercise interaction on the brain plasticity for both facilita

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Application-level Benchmarking of Quantum Computers using Nonlocal Game Strategies

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arXiv 2023年

作者： Furches, Jim Chehade, Sarah Hamilton, Kathleen Wiebe, Nathan Marrero, Carlos Ortiz College of Computing Georgia Institute of Technology AtlantaGA30332 United States Physical Detection Systems and Deployment Division Pacific Northwest National Laboratory RichlandWA99354 United States Quantum Computational Science Group Oak Ridge National Laboratory Oak RidgeTN37830 United States Department of Computer Science University of Toronto ONM5S 1A1 Canada High Performance Computing Group Pacific Northwest National Laboratory RichlandWA99354 United States Canadian Institute for Advanced Research TorontoONM5G 1M1 Canada Department of Electrical & Computer Engineering North Carolina State University RaleighNC27607 United States

In a nonlocal game, two noncommunicating players cooperate to convince a referee that they possess a strategy that does not violate the rules of the game. Quantum strategies allow players to optimally win some games by performing joint measurements on a shared entangled state, but computing these strategies can be challenging. We present a variational quantum algorithm to compute quantum strategies for nonlocal games by encoding the rules of a nonlocal game into a Hamiltonian. We show how this algorithm can generate a short-depth optimal quantum strategy for a graph coloring game with a quantum advantage. This quantum strategy is then evaluated on fourteen different quantum hardware platforms to demonstrate its utility as a benchmark. Finally, we discuss potential sources of errors that can explain the observed decreased performance of the executed task and derive an expression for the number of samples required to accurately estimate the win rate in the presence of noise. Copyright © 2023, The Authors. All rights reserved.

关键词： Hamiltonians

Enhanced meta-displays using advanced phase-change materials

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arXiv 2021年

作者： Hemmatyar, Omid Abdollahramezani, Sajjad Zeimpekis, Ioannis Lepeshov, Sergey Krasnok, Alex Khan, Asir Intisar Neilson, Kathryn M. Teichrib, Christian Brown, Tyler Pop, Eric Hewak, Daniel W. Wuttig, Matthias Alù, Andrea Muskens, Otto L. Adibi, Ali School of Electrical and Computer Engineering Georgia Institute of Technology 778 Atlantic Drive NW AtlantaGA30332-0250 United States Zepler Institute Faculty of Engineering and Physical Sciences University of Southampton SouthamptonSO17 1BJ United Kingdom ITMO University St. Petersburg197101 Russia Photonics Initiative Advanced Science Research Center City University of New York New YorkNY10031 United States Department of Electrical Engineering Department of Materials Science and Engineering Precourt Institute for Energy Stanford University StanfordCA94305 United States Physikalisches Institut IA RWTH Aachen Sommerfeldstrasse 14 Aachen52074 Germany Physics Program Graduate Center City University of New York New YorkNY10016 United States Physics and Astronomy Faculty of Engineering and Physical Sciences University of Southampton SouthamptonSO17 1BJ United Kingdom

Structural colors generated due to light scattering from static all-dielectric metasurfaces have successfully enabled high-resolution, high-saturation, and wide-gamut color printing applications. Despite recent advances, most demonstrations of these structure-dependent colors lack post-fabrication tunability. This hinders their applicability for front-end dynamic display technologies. Phase-change materials (PCMs), with significant contrast of their optical properties between their amorphous and crystalline states, have demonstrated promising potentials in reconfigurable nanophotonics. Herein, we leverage tunable all-dielectric reflective metasurfaces made of newly emerged classes of low-loss optical PCMs, i.e., antimony trisulphide (Sb2S3) and antimony triselenide (Sb2Se3), with superb characteristics to realize switchable, high-saturation, high-efficiency and high-resolution dynamic meta-pixels. Exploiting polarization-sensitive building blocks, the presented meta-pixel can generate two different colors when illuminated by either one of two orthogonally polarized incident beams. Such degrees of freedom (i.e., material phase and polarization state) enable a single reconfigurable metasurface with fixed geometrical parameters to generate four distinct wide-gamut colors. We experimentally demonstrate, for the first time, an electrically-driven micro-scale display through the integration of phase-change metasurfaces with an on-chip heater formed by transparent conductive oxide. Our experimental findings enable a versatile platform suitable for a wide range of applications, including tunable full-color printing, enhanced dynamic displays, information encryption, and anti-counterfeiting. © 2021, CC BY.

关键词： Light scattering

Machine Learning Link Inference of Noisy Delay-Coupled Networks with Optoelectronic Experimental Tests

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physical Review X 2021年第3期11卷 031014-031014页

作者： Amitava Banerjee Joseph D. Hart Rajarshi Roy Edward Ott Department of Physics University of Maryland College Park Maryland 20742 USA Institute for Research in Electronics and Applied Physics University of Maryland College Park Maryland 20742 USA Optical Sciences Division United States Naval Research Laboratory Washington D.C. 20375 USA Institute for Physical Science and Technology University of Maryland College Park Maryland 20742 USA Department of Electrical and Computer Engineering University of Maryland College Park Maryland 20742 USA

We devise a machine learning technique to solve the general problem of inferring network links that have time delays using only time series data of the network nodal states. This task has applications in many fields, e.g., from applied physics, data science, and engineering to neuroscience and biology. Our approach is to first train a type of machine learning system known as reservoir computing to mimic the dynamics of the unknown network. We then use the trained parameters of the reservoir system output layer to deduce an estimate of the unknown network structure. Our technique, by its nature, is noninvasive but is motivated by the widely used invasive network inference method, whereby the responses to active perturbations applied to the network are observed and employed to infer network links (e.g., knocking down genes to infer gene regulatory networks). We test this technique on experimental and simulated data from delay-coupled optoelectronic oscillator networks, with both identical and heterogeneous delays along the links. We show that the technique often yields very good results, particularly if the system does not exhibit synchrony. We also find that the presence of dynamical noise can strikingly enhance the accuracy and ability of our technique, especially in networks that exhibit synchrony.

关键词： Dynamics of networks Network structure Noise Optoelectronics Synchronization Artificial neural networks Coupled oscillators Directed networks Dynamical systems Nonlinear time-delay systems Technological networks In-vitro methods Machine learning Time series analysis