检索结果-内蒙古大学图书馆

The molecular epidemiology of multiple zoonotic origins of SARS-CoV-2

四川生理科学杂志 2022年第7期44卷 1299-1299页

作者： Jonathan E Pekar Bioinformatics and Systems Biology Graduate Program University of California San Diego La Jolla CA 92093 USA. Department of Biomedical Informatics University of California San Diego La Jolla CA 92093 USA. Department of Human Genetics David Geffen School of Medicine University of California Los Angeles Los Angeles CA 90095 USA. Department of Immunology and Microbiology The Scripps Research Institute La Jolla CA 92037 USA. Department of Computer Science and Engineering University of California San Diego La Jolla CA 92093 USA. Department of Mathematics University of California San Diego La Jolla CA 92093 USA. Department of Ecology and Evolutionary Biology University of Arizona Tucson AZ 85721 USA. W. Harry Feinstone Department of Molecular Microbiology and Immunology Johns Hopkins Bloomberg School of Public Health Baltimore MD 21205 USA. New York City Public Health Laboratory New York City Department of Health and Mental Hygiene New York NY 11101 USA. Department of Microbiology Institute for Viral Diseases Biosafety Center College of Medicine Korea University Seoul South Korea. BK21 Graduate Program Department of Biomedical Sciences Korea University College of Medicine Seoul 02841 Republic of Korea. National Public Health Laboratory National Centre for Infectious Diseases Singapore. Malaysia Genome and Vaccine Institute Jalan Bangi 43000 Kajang Selangor Malaysia. Department of Medicine University of California San Diego La Jolla CA 92093 USA. Department of Microbiology and Immunology School of Medicine Tulane University New Orleans LA 70112 USA. Zalgen Labs Frederick MD 21703 USA. Global Virus Network (GVN) Baltimore MD 21201 USA. Sydney Institute for Infectious Diseases School of Life and Environmental Sciences and School of Medical Sciences The University of Sydney Sydney NSW 2006 Australia. Institute of Evolutionary Biology University of Edinburgh King’s Buildings Edinburgh EH9 3FL UK. Department of Biomathematics David Geffen Sch

Understanding the circumstances that lead to pandemics is important for their prevention. Here, we analyze the genomic diversity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) early in the coronavirus disease 2019 (COVID-19) pandemic. We show that SARS-CoV-2 genomic diversity before February 2020 likely comprised only two distinct viral lineages, denoted A and B. Phylodynamic rooting methods, coupled with epidemic simulations, reveal that these lineages were the result of at least two separate cross-species transmission events into humans. The first zoonotic transmission likely involved lineage B viruses around 18 November 2019 (23 October-8 December), while the separate introduction of lineage A likely occurred within weeks of this event.

关键词： epidemiology likely acute

来源：评论

学校读者我要写书评

暂无评论

Nonreciprocal hyperbolic propagation over moving metasurfaces

引用

Physical Review B 2019年第4期99卷 045407-045407页

作者： Yarden Mazor Andrea Alù Department of Electrical and Computer Engineering The University of Texas at Austin Austin Texas 78712 USA Photonics Initiative Advanced Science Research Center City University of New York New York New York 10031 USA Physics Program Graduate Center City University of New York New York New York 10026 USA Department of Electrical Engineering City College of New York New York New York 10031 USA

Hyperbolic propagation offers exciting opportunities in nanophotonics, from subdiffraction imaging to enhanced local density of states. This transport regime is typically induced by strong modulation of conductivity, i.e., with alternating metallic and dielectric material properties. Here, we analyze a moving impedance surface, showing that suitably tailored homogeneous metasurfaces can support one-way hyperbolic propagation when in motion, adding nonreciprocity to hyperbolic propagation phenomena, and without suffering from nonlocal effects stemming from discretization or finite granularity of the surface.

关键词： Electromagnetism Metamaterials Photonics

来源：评论

学校读者我要写书评

暂无评论

Conventional and adaptive strategies applied to DC motor control using microcontroller PIC18F4520 7

Conventional and adaptive strategies applied to DC motor con...

引用

7th Brazilian electrical Systems Symposium, SBSE 2018

作者： Taveiros, Filipe Emanuel Vieira Barros, Luciano Sales Barros, Camila Mara Vital Electrical Engineering and Computing Graduate Program of Federal University of Rio Grande Do Norte Natal Brazil Electrical Engineering Department of Federal University of Rio Grande Do Norte Natal Brazil Computer Systems Department of Federal University of Paraíba João Pessoa Brazil

ISBN: (纸本)9781538633632

In this paper strategies to control the speed of a generic DC motor system are discussed. They range from the conventional, like PID and state-feedback, to reference model adaptive algorithms such as MRAC, VS-MRAC and DMARC. The goal of this study is to determine the best control strategy for high-performance applications regarding to stability, robustness and optimal controller effort. In theory and sometimes in practice, all these control strategies proof themselves reliable, however, in heavy-duty set-point references the application requires high performance of the controller under disturbances, unmodeled dynamics and variable speed reference conditions. The use of appropriate control strategies can highly contribute to this purpose. To support the conclusions, the control strategies have been embedded in a microcontroller PIC18F4520 and applied to a test motor in order to obtain experimental results. © 2018 IEEE.

关键词： Three term control systems

来源：评论

学校读者我要写书评

暂无评论

MetaMOPE: a web service for mobile phase determination and fast chromatography peaks evaluation for metabolomics

引用

Bioinformatics Advances 2023年第1期3卷

作者： Tsai, Dong-Ming Chang, Ching-Yao Lin, Shih-Ming Kuo, Tien-Chueh Wang, San-Yuan Chen, Guan-Yuan Kuo, Ching-Hua Tseng, Yufeng Jane Graduate Institute of Biomedical Electronics and Bioinformatics National Taiwan University Taipei 106216 Taiwan The Metabolomics Core Laboratory Centers of Genomic and Precision Medicine National Taiwan University Taipei 100225 Taiwan Department of Computer Science and Information Engineering National Taiwan University Taipei 106216 Taiwan Master Program for Clinical Pharmacogenomics and Pharmacoproteomics School of Pharmacy Taipei Medical University Taipei 110301 Taiwan Forensic Medicine College of Medicine National Taiwan University Taipei 100225 Taiwan School of Pharmacy College of Medicine National Taiwan University Taipei 100225 Taiwan

来源：评论

学校读者我要写书评

暂无评论

Hyperbolic Sound Propagation over Nonlocal Acoustic Metasurfaces

引用

Physical Review Letters 2019年第24期123卷 244303-244303页

作者： Li Quan Andrea Alù Department of Electrical and Computer Engineering The University of Texas at Austin Austin Texas 78712 USA Photonics Initiative Advanced Science Research Center City University of New York New York New York 10031 USA Physics Program Graduate Center City University of New York New York New York 10016 USA Department of Electrical Engineering City College of The City University of New York New York 10031 USA

Hyperbolic metasurfaces, supporting extreme anisotropy of the surface impedance tensor, have recently been explored in nanophotonic systems for robust diffractionless propagation over a surface, offering interesting opportunities for subdiffraction imaging and enhanced Purcell emission. In acoustics, due to the longitudinal nature of sound transport in fluids, these phenomena are forbidden by symmetry, requiring the acoustic surface impedance to be inherently isotropic. Here we show that nonlocalities produced by strong coupling between neighboring impedance elements enable extreme anisotropic responses for sound traveling over a surface, supporting negative phase and energy velocities, as well as hyperbolic propagation for acoustic surface waves.

关键词： Acoustics Hyperbolic metamaterials Metamaterials

来源：评论

学校读者我要写书评

暂无评论

Angular-momentum selectivity and asymmetry in highly confined wave propagation along sheath-helical metasurface tubes

引用

Physical Review B 2019年第15期99卷 155425-155425页

Highly confined surface waves present unique opportunities to enhance light interactions with localized emitters or molecules. Hyperbolic dispersion in metasurfaces allows us to tailor and manipulate surface waves, enhancing the local density of states over broad bandwidths. So far, propagation on this platform was mainly studied in planar geometries, which facilitates the analysis but somehow limits the realm of possibilities. Here we show that “wrapping” hyperbolic metasurfaces into tubes may greatly enrich the wave propagation dynamics along their axis. This system shows strong interaction with fields and sources carrying optical angular momentum and pronounced field asymmetries, and opens pathways to valley-specific excitation and routing. In addition, we demonstrate that various parameter regimes enable strong spin/helicity momentum locking.

关键词： Angular momentum of light Hyperbolic metamaterials Light-matter interaction Surface plasmons Surfaces

来源：评论

学校读者我要写书评

暂无评论

Passive Acoustic Metasurface with Unitary Reflection Based on Nonlocality

引用

Physical Review Applied 2019年第5期11卷 054077-054077页

作者： Li Quan Andrea Alù Department of Electrical and Computer Engineering The University of Texas at Austin Austin Texas 78712 USA Photonics Initiative Advanced Science Research Center City University of New York New York New York 10031 USA Physics Program Graduate Center City University of New York New York New York 10026 USA Department of Electrical Engineering City College of New York New York New York 10031 USA

Metasurfaces have introduced large flexibility in manipulating the impinging wavefront for light and sound by locally engineering the reflection and transmission coefficients based on generalized Snell’s laws. Local phenomena in each unit cell, however, are fundamentally limited in the level of efficiency with which anomalous wavefront transformations can be achieved. Here, we explore acoustic metasurfaces with suitably engineered nonlocality, obtained by coupling neighboring cells. We demonstrate that nonlocal passive metastructures can overcome the limitations of local designs, and mimic balanced gain and loss distributions, enabling unitary efficiency for extreme beam steering.

关键词： Acoustic metamaterials Acoustic wave phenomena Beam control Beam optics Light propagation, transmission & absorption

来源：评论

学校读者我要写书评

暂无评论

Cameraless High-throughput 3D Imaging Flow Cytometry

arXiv

引用

arXiv 2019年

作者： Han, Yuanyuan Tang, Rui Gu, Yi Zhang, Alex Ce Cai, Wei Castor, Violet Cho, Sung Hwan Alaynick, William Lo, Yu-Hwa Department of Electrical and Computer Engineering University of California San Diego La JollaCA United States Materials Science and Engineering Program University of California San Diego La JollaCA United States NanoCellect Biomedical Inc San DiegoCA United States

Increasing demand for understanding the vast heterogeneity of cellular phenotypes has driven the development of imaging flow cytometry (IFC), that combines features of flow cytometry with fluorescence and bright field microscopy. IFC combines the throughput and statistical advantage of flow cytometry with the ability to discretely measure events based on a real or computational image, as well as conventional flow cytometry metrics. A limitation of existing IFC systems is that, regardless of detection methodology, only two-dimensional (2D) cell images are obtained. Without tomographic three-dimensional (3D) resolution the projection problem remains: Collapsing 3D information onto a 2D image, limiting the reliability of spot counting or co-localization crucial to cell phenotyping. Here we present a solution to the projection problem: Three-dimensional imaging flow cytometry (3D-IFC), a high-throughput 3D cell imager based on optical sectioning microscopy. We combine orthogonal light-sheet scanning illumination with our previous spatiotemporal transformation detection to produce 3D cell image reconstruction from a cameraless single-pixel photodetector readout. We further demonstrate this capability by co-capturing 3D fluorescence and label-free side-scattering images of single cells in flow at a velocity of 0.2 m s-1, corresponding to a throughput of approximately 500 cells per second with 60,000 voxels (resized subsequently to 106voxels) for each cell image at a resolution of less than 1 micron in X, Y, and Z dimensions. Improved high-throughput imaging tools are needed to phenotype-genotype recognized heterogeneity in the fields of immunology, oncology, cell- A nd gene-therapy, and drug discovery. Copyright © 2019, The Authors. All rights reserved.

关键词： Cytology

来源：评论

学校读者我要写书评

暂无评论

Electron Acceleration in Carbon Nanotubes

arXiv

引用

arXiv 2025年

作者： Bonţoiu, Cristian Bonatto, Alexandre Apsimon, Öznur Bandiera, Laura Cavoto, Gianluca Drebot, Illya Gatti, Giancarlo Giner-Navarro, Jorge Lei, Bifeng Martín-Luna, Pablo Rago, Ilaria Pérez, Juan Rodríguez Nunes, Bruno Silveira Sytov, Alexei Valagiannopoulos, Costas Welsch, Carsten P. Xia, Guoxing Resta-López, Javier Department of Physics University of Liverpool Oxford Street LiverpoolL69 7ZE United Kingdom Graduate Program in Information Technology and Healthcare Management the Beam Physics Group Federal University of Health Sciences of Porto Alegre RS Porto Alegre90050-170 Brazil Department of Physics and Astronomy University of Manchester Oxford Road ManchesterM13 9PL United Kingdom Cockroft Institute Keckwick Lane Daresbury WarringtonWA4 4AD United Kingdom INFN Sezione di Ferrara Via Saragat 1 Ferrara44122 Italy Dipartimento di Fisica Sapienza Università di Roma Piazzale Aldo Moro 2 Roma00185 Italy INFN Sezione di Roma Piazzale Aldo Moro 2 Rome00185 Italy INFN Sezione di Milano Via G. Celoria 16 Milano20133 Italy Centro de Láseres Pulsados Building M5 Science Park Calle Adaja 8 Salamanca Villamayor37185 Spain Universidad de Valencia Paterna46071 Spain Universidad de Valencia CSIC Paterna46980 Spain Nuclear and Energy Research Institute IPEN–CNEN SP São Paulo Brazil National Technical University of Athens School of Electrical and Computer Engineering Zografou157 73 Greece Departamento de Física Aplicada y Electromagnetismo Universidad de Valencia Burjassot46100 Spain

Laser wakefield acceleration (LWFA) may achieve TeV/m gradients using high-density solid-state plasmas as accelerating media. However, the application of bulk solid materials requires attosecond laser pulses, such as X-ray lasers, to drive wakefields at these high densities. Additionally, the short wakefield wavelengths associated with solid-state plasmas greatly limit the accelerating length. An alternative approach employs 2D carbon-based nanomaterials, like graphene or carbon nanotubes (CNTs), configured into structured targets. These nanostructures are designed with voids or low-density regions to effectively reduce the overall plasma density. This reduction enables the use of longer-wavelength lasers and also extends the plasma wavelength and the acceleration length. In this study, we present, to our knowledge, the first numerical demonstration of electron acceleration via self-injection into a wakefield bubble driven by an infrared laser pulse in structured CNT targets, similar to the behavior observed in gaseous plasmas for LWFA in the nonlinear (or bubble) regime. Using the PIConGPU code, bundles of CNTs are modeled in a 3D geometry as 25 nm-thick carbon tubes with an initial density of 1022 cm−3. The carbon plasma is ionized by a three-cycle, 800 nm wavelength laser pulse with a peak intensity of 1021 W cm−2, achieving an effective plasma density of 1020 cm−3. The same laser also drives the wakefield bubble, responsible for the electron self-injection and acceleration. Simulation results indicate that fs-long electron bunches with hundreds of pC charge can be self-injected and accelerated at gradients exceeding 1 TeV/m. Both charge and accelerating gradient figures are unprecedented when compared with LWFA in gaseous plasma. © 2025, CC BY-NC-ND.

关键词： X ray lasers

来源：评论

学校读者我要写书评

暂无评论

Author Correction: A high-performance neuroprosthesis for speech decoding and avatar control

引用

Nature 2024年第8021期631卷 E13页

作者： Sean L Metzger Kaylo T Littlejohn Alexander B Silva David A Moses Margaret P Seaton Ran Wang Maximilian E Dougherty Jessie R Liu Peter Wu Michael A Berger Inga Zhuravleva Adelyn Tu-Chan Karunesh Ganguly Gopala K Anumanchipalli Edward F Chang Department of Neurological Surgery University of California San Francisco San Francisco CA USA. Weill Institute for Neuroscience University of California San Francisco San Francisco CA USA. University of California Berkeley-University of California San Francisco Graduate Program in Bioengineering Berkeley CA USA. Department of Electrical Engineering and Computer Sciences University of California Berkeley Berkeley CA USA. Speech Graphics Ltd Edinburgh UK. Department of Neurology University of California San Francisco San Francisco CA USA. Department of Neurological Surgery University of California San Francisco San Francisco CA USA. edward.chang@ucsf.edu. Weill Institute for Neuroscience University of California San Francisco San Francisco CA USA. edward.chang@ucsf.edu. University of California Berkeley-University of California San Francisco Graduate Program in Bioengineering Berkeley CA USA. edward.chang@ucsf.edu.

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：