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Martis J, Susarla S, Rayabharam A, Su C, Paule T, Pelz P, Huff C, Xu X, Li HK, Jaikissoon M, Chen V, Pop E, Saraswat K, Zettl A, Aluru NR, Ramesh R, Ercius P, Majumdar A. Imaging the electron charge density in monolayer MoS 2 at the Ångstrom scale. Nat Commun 2023; 14:4363. [PMID: 37474521 PMCID: PMC10359339 DOI: 10.1038/s41467-023-39304-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 06/06/2023] [Indexed: 07/22/2023] Open
Abstract
Four-dimensional scanning transmission electron microscopy (4D-STEM) has recently gained widespread attention for its ability to image atomic electric fields with sub-Ångstrom spatial resolution. These electric field maps represent the integrated effect of the nucleus, core electrons and valence electrons, and separating their contributions is non-trivial. In this paper, we utilized simultaneously acquired 4D-STEM center of mass (CoM) images and annular dark field (ADF) images to determine the projected electron charge density in monolayer MoS2. We evaluate the contributions of both the core electrons and the valence electrons to the derived electron charge density; however, due to blurring by the probe shape, the valence electron contribution forms a nearly featureless background while most of the spatial modulation comes from the core electrons. Our findings highlight the importance of probe shape in interpreting charge densities derived from 4D-STEM and the need for smaller electron probes.
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Affiliation(s)
- Joel Martis
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Sandhya Susarla
- The National Center for Electron Microscopy (NCEM), The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA
| | - Archith Rayabharam
- Department of Mechanical Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Cong Su
- Department of Physics, University of California Berkeley, Berkeley, CA, USA
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, USA
- Kavli Energy NanoScience Institute, University of California Berkeley, Berkeley, CA, USA
| | - Timothy Paule
- Department of Physics, University of California Berkeley, Berkeley, CA, USA
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, USA
- Kavli Energy NanoScience Institute, University of California Berkeley, Berkeley, CA, USA
| | - Philipp Pelz
- The National Center for Electron Microscopy (NCEM), The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Institute of Micro- and Nanostructure Research & Center for Nanoanalysis and Electron Microscopy (CENEM), Department of Materials Science, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Cassandra Huff
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Xintong Xu
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Hao-Kun Li
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Marc Jaikissoon
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Victoria Chen
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Eric Pop
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Krishna Saraswat
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Alex Zettl
- Department of Physics, University of California Berkeley, Berkeley, CA, USA
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, USA
- Kavli Energy NanoScience Institute, University of California Berkeley, Berkeley, CA, USA
| | - Narayana R Aluru
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Ramamoorthy Ramesh
- Department of Physics, University of California Berkeley, Berkeley, CA, USA
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, USA
| | - Peter Ercius
- The National Center for Electron Microscopy (NCEM), The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Arun Majumdar
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA.
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2
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Aluru NR, Aydin F, Bazant MZ, Blankschtein D, Brozena AH, de Souza JP, Elimelech M, Faucher S, Fourkas JT, Koman VB, Kuehne M, Kulik HJ, Li HK, Li Y, Li Z, Majumdar A, Martis J, Misra RP, Noy A, Pham TA, Qu H, Rayabharam A, Reed MA, Ritt CL, Schwegler E, Siwy Z, Strano MS, Wang Y, Yao YC, Zhan C, Zhang Z. Fluids and Electrolytes under Confinement in Single-Digit Nanopores. Chem Rev 2023; 123:2737-2831. [PMID: 36898130 PMCID: PMC10037271 DOI: 10.1021/acs.chemrev.2c00155] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Confined fluids and electrolyte solutions in nanopores exhibit rich and surprising physics and chemistry that impact the mass transport and energy efficiency in many important natural systems and industrial applications. Existing theories often fail to predict the exotic effects observed in the narrowest of such pores, called single-digit nanopores (SDNs), which have diameters or conduit widths of less than 10 nm, and have only recently become accessible for experimental measurements. What SDNs reveal has been surprising, including a rapidly increasing number of examples such as extraordinarily fast water transport, distorted fluid-phase boundaries, strong ion-correlation and quantum effects, and dielectric anomalies that are not observed in larger pores. Exploiting these effects presents myriad opportunities in both basic and applied research that stand to impact a host of new technologies at the water-energy nexus, from new membranes for precise separations and water purification to new gas permeable materials for water electrolyzers and energy-storage devices. SDNs also present unique opportunities to achieve ultrasensitive and selective chemical sensing at the single-ion and single-molecule limit. In this review article, we summarize the progress on nanofluidics of SDNs, with a focus on the confinement effects that arise in these extremely narrow nanopores. The recent development of precision model systems, transformative experimental tools, and multiscale theories that have played enabling roles in advancing this frontier are reviewed. We also identify new knowledge gaps in our understanding of nanofluidic transport and provide an outlook for the future challenges and opportunities at this rapidly advancing frontier.
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Affiliation(s)
- Narayana R Aluru
- Oden Institute for Computational Engineering and Sciences, Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, 78712TexasUnited States
| | - Fikret Aydin
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Martin Z Bazant
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Daniel Blankschtein
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Alexandra H Brozena
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
| | - J Pedro de Souza
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Menachem Elimelech
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut06520-8286, United States
| | - Samuel Faucher
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - John T Fourkas
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland20742, United States
- Maryland NanoCenter, University of Maryland, College Park, Maryland20742, United States
| | - Volodymyr B Koman
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Matthias Kuehne
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Hao-Kun Li
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| | - Yuhao Li
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Zhongwu Li
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Arun Majumdar
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| | - Joel Martis
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
| | - Rahul Prasanna Misra
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - Aleksandr Noy
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
- School of Natural Sciences, University of California Merced, Merced, California95344, United States
| | - Tuan Anh Pham
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Haoran Qu
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
| | - Archith Rayabharam
- Oden Institute for Computational Engineering and Sciences, Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, 78712TexasUnited States
| | - Mark A Reed
- Department of Electrical Engineering, Yale University, 15 Prospect Street, New Haven, Connecticut06520, United States
| | - Cody L Ritt
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut06520-8286, United States
| | - Eric Schwegler
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Zuzanna Siwy
- Department of Physics and Astronomy, Department of Chemistry, Department of Biomedical Engineering, University of California, Irvine, Irvine92697, United States
| | - Michael S Strano
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts02139, United States
| | - YuHuang Wang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland20742, United States
- Maryland NanoCenter, University of Maryland, College Park, Maryland20742, United States
| | - Yun-Chiao Yao
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
- School of Natural Sciences, University of California Merced, Merced, California95344, United States
| | - Cheng Zhan
- Materials Science Division, Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, California94550, United States
| | - Ze Zhang
- Department of Mechanical Engineering, Stanford University, Stanford, California94305, United States
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Liu QP, Liang L, Zhang XY, Li HK, Zhao CX, Liu XY. Mitochondrial Phylogenomics Suggests Complex Evolutionary Pattern of Pronotal Foliaceous Mimicry in Hierodulinae (Mantodea: Mantidae), with Description of a New Species of Rhombodera Burmeister, 1838 from China. Insects 2022; 13:715. [PMID: 36005341 PMCID: PMC9409270 DOI: 10.3390/insects13080715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 08/02/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Hierodulinae is a species-rich mantid subfamily, with some species bearing a notable leaf-like pronotum. However, the evolutionary pattern and taxonomic significance of the leaf-like pronotum are largely unknown. Here, we present a phylogenomic analysis of the Hierodulinae genera Rhombodera Burmeister, 1838, and Hierodula Burmeister, 1838 based on mitochondrial genomes. We also describe a new species, namely Rhombodera hyalina sp. nov. from Guangxi, China. Our phylogenetic result, together with the evidence from male genitalia, suggests the division of the Oriental Hierodula and Rhombodera complex into three clades. We find a complex pattern on the evolution of the leaf-like pronotum, which is present in at least five lineages, respectively, of the above three clades.
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Affiliation(s)
- Qin-Peng Liu
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Le Liang
- College of Biological Science, China Agricultural University, Beijing 100193, China
| | - Xin-Yang Zhang
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Hao-Kun Li
- School of Biomedicine, University of Melbourne, Parkville, VA 3010, Australia
| | - Chu-Xiang Zhao
- College of Software Engineering, Northwestern Polytechnical University, Xi’an 710129, China
| | - Xing-Yue Liu
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China
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Qian LX, Yan L, Xu ZW, Shan LQ, Wang WT, He LM, He SM, Fan Y, Ge CY, Li HK, Hao DJ. [Early efficacy of three dimensional printed anatomical biomimetic cervical artificial disc replacement in the treatment of cervical degenerative diseases]. Zhonghua Wai Ke Za Zhi 2022; 60:223-229. [PMID: 35078297 DOI: 10.3760/cma.j.cn112139-20211202-00575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Objective: To investigate the efficacy and safety of a new cervical artificial disc prosthesis in the treatment of cervical degenerative diseases. Methods: The clinical data of 18 patients with single-level cervical degenerative diseases who underwent three dimensional printed anatomical bionic cervical disc replacement at Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University from May 2019 to July 2020 were analyzed retrospectively. There were 7 males and 11 females,aged (45±8) years old(range:28 to 58 years).The surgical segment was located at C3-4 level in 2 cases, C4-5 level in 5 cases, C5-6 level in 9 cases, and C6-7 level in 2 cases.The clinical and radiographic outcomes were recorded and compared at preoperative,postoperative times of one month and twelve months.The clinical assessments contained Japanese orthopedic association (JOA) score,neck disability index (NDI) and visual analogue scale (VAS).Imaging assessments included range of motion (ROM) of cervical spine, prosthesis subsidence and prosthesis anteroposterior migration.Repeated measurement variance analysis was used for comparison between groups,and paired t test was used for pairwise comparison. Results: All patients underwent the operation successfully and were followed up for more than 12 months.Compared with preoperative score,the JOA score,NDI and VAS were significantly improved after surgery (all P<0.01).There was no significant difference in postoperative ROM compared with 1-and 12-month preoperative ROM (t=1.570,P=0.135;t=1.744,P=0.099). The prosthesis subsidence was (0.29±0.13) mm (range: 0.18 to 0.50 mm) at 12-month postoperatively.The migration of prosthesis at 12-months postoperatively were (0.71±0.20) mm (range: 0.44 to 1.08 mm).There was no prosthesis subsidence or migration>2 mm at 12-month postoperatively. Conclusion: Three dimensional printed anatomical biomimetic cervical artificial disc replacement has a good early clinical effect in the treatment of cervical degenerative diseases, good mobility can be obtained while maintaining stability.
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Affiliation(s)
- L X Qian
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - L Yan
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - Z W Xu
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - L Q Shan
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - W T Wang
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - L M He
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - S M He
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - Y Fan
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - C Y Ge
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - H K Li
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
| | - D J Hao
- Department of Spinal Surgery,Honghui Hospital,Xi'an Jiaotong University,Xi'an 710054,China
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5
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Zhang Z, Martis J, Xu X, Li HK, Xie C, Takasuka B, Lee J, Roy AK, Majumdar A. Photoabsorption Imaging at Nanometer Scales Using Secondary Electron Analysis. Nano Lett 2021; 21:1935-1942. [PMID: 33635654 DOI: 10.1021/acs.nanolett.0c03993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Optical imaging with nanometer resolution offers fundamental insights into light-matter interactions. Traditional optical techniques are diffraction limited with a spatial resolution >100 nm. Optical super-resolution and cathodoluminescence techniques have higher spatial resolutions, but these approaches require the sample to fluoresce, which many materials lack. Here, we introduce photoabsorption microscopy using electron analysis, which involves spectrally specific photoabsorption that is locally probed using a scanning electron microscope, whereby a photoabsorption-induced surface photovoltage modulates the secondary electron emission. We demonstrate spectrally specific photoabsorption imaging with sub-20 nm spatial resolution using silicon, germanium, and gold nanoparticles. Theoretical analysis and Monte Carlo simulations are used to explain the basic trends of the photoabsorption-induced secondary electron signal. Based on our current experiments and this analysis, we expect that the spatial resolution can be further improved to a few nanometers, thereby offering a general approach for nanometer-scale optical spectroscopic imaging and material characterization.
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Affiliation(s)
- Ze Zhang
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - Joel Martis
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - Xintong Xu
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - Hao-Kun Li
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - Chenlu Xie
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - Brad Takasuka
- Silicon Valley Peripherals Inc., San Jose, California 95117, United States
| | - Jonghoon Lee
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, WPAFB, Ohio 45433, United States
| | - Ajit K Roy
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, WPAFB, Ohio 45433, United States
| | - Arun Majumdar
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
- Department of Photon Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Precourt Institute for Energy, Stanford University, Stanford, California 94305, United States
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6
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Li HK, Pedro de Souza J, Zhang Z, Martis J, Sendgikoski K, Cumings J, Bazant MZ, Majumdar A. Imaging Arrangements of Discrete Ions at Liquid-Solid Interfaces. Nano Lett 2020; 20:7927-7932. [PMID: 33079557 DOI: 10.1021/acs.nanolett.0c02669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The individual and collective behavior of ions near electrically charged interfaces is foundational to a variety of electrochemical phenomena encountered in biology, energy, and the environment. While many theories have been developed to predict the interfacial arrangements of counterions, direct experimental observations and validations have remained elusive. Utilizing cryo-electron microscopy, here we directly visualize individual counterions and reveal their discrete interfacial layering. Comparison with simulations suggests the strong effects of finite ionic size and electrostatic interactions. We also uncover correlated ionic structures under extreme confinement, with the channel widths approaching the ionic diameter (∼1 nm). Our work reveals the roles of ionic size, valency, and confinement in determining the structures of liquid-solid interfaces and opens up new opportunities to study such systems at the single-ion level.
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Affiliation(s)
- Hao-Kun Li
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - J Pedro de Souza
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Ze Zhang
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - Joel Martis
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
| | - Kyle Sendgikoski
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
- Department of Physics, University of Maryland, College Park, Maryland 20742, United States
| | - John Cumings
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Martin Z Bazant
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Arun Majumdar
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
- Department of Photon Science, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Precourt Institute for Energy, Stanford University, Stanford, California 94305, United States
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7
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Fong KY, Li HK, Zhao R, Yang S, Wang Y, Zhang X. Phonon heat transfer across a vacuum through quantum fluctuations. Nature 2019; 576:243-247. [PMID: 31827291 DOI: 10.1038/s41586-019-1800-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 10/17/2019] [Indexed: 11/09/2022]
Abstract
Heat transfer in solids is typically conducted through either electrons or atomic vibrations known as phonons. In a vacuum, heat has long been thought to be transferred by radiation but not by phonons because of the lack of a medium1. Recent theory, however, has predicted that quantum fluctuations of electromagnetic fields could induce phonon coupling across a vacuum and thereby facilitate heat transfer2-4. Revealing this unique quantum effect experimentally would bring fundamental insights to quantum thermodynamics5 and practical implications to thermal management in nanometre-scale technologies6. Here we experimentally demonstrate heat transfer induced by quantum fluctuations between two objects separated by a vacuum gap. We use nanomechanical systems to realize strong phonon coupling through vacuum fluctuations, and observe the exchange of thermal energy between individual phonon modes. The experimental observation agrees well with our theoretical calculations and is unambiguously distinguished from other effects such as near-field radiation and electrostatic interaction. Our discovery of phonon transport through quantum fluctuations represents a previously unknown mechanism of heat transfer in addition to the conventional conduction, convection and radiation. It paves the way for the exploitation of quantum vacuum in energy transport at the nanoscale.
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Affiliation(s)
- King Yan Fong
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, USA
| | - Hao-Kun Li
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, USA
| | - Rongkuo Zhao
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, USA
| | - Sui Yang
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, USA
| | - Yuan Wang
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, USA
| | - Xiang Zhang
- Nanoscale Science and Engineering Center, University of California, Berkeley, CA, USA. .,Faculties of Science and Engineering, The University of Hong Kong, Hong Kong, China.
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Bai N, Yang LF, An LH, Wang W, Li YQ, Sheng Y, Wang T, Li HK, Yuan L. [Dynamic visual analysis of neutrophils chemotaxis in peritoneal cavity of schizophrenic model in mice]. Beijing Da Xue Xue Bao Yi Xue Ban 2018; 50:226-230. [PMID: 29643519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVE To compare the differences of neutrophils chemotaxis ability in peritoneal cavity between normal rats and schizopherenic rats with cell dynamic visualization system. METHODS In the study,18 healthy Kunming rats were randomly divided into 3 groups which were control group (n=6), 0.3 mg/kg MK-801 treatment group (n=6), 0.6 mg/kg dizocilpine maleate (MK-801) treatment group(n=6), extracted neutrophils separately, and observed the morphology and counted under a microscope. Each group of cells was divided into two parts for chemotactic experiment, called chemokine agent treatment group and no chemokine agent treatment group respectively, indicating control 1, 0.3 mg/kg MK-801 treatment 1,0.6 mg/kg MK-801 treatment 1 and control 2, 0.3 mg/kg MK-801 treatment 2,0.6 mg/kg MK-801 treatment 2. The dynamic migration of cells was recorded using the NIS-Elements software, and TAXIScan Analyzer 2 software was used to select 30 cells (n=30) in each group of cells and analyze cells migration trajectory, speed and distance, and use pair test and One-Way analysis of variance for statistical analysis. RESULTS The number of neutrophils in control group, 0.3 mg/kg MK-801 treatment group and 0.6 mg/kg MK-801 treatment group were(1.00±0.03)×104/mL,(0.05±0.02)×104/mL,(0.32±0.01)×104/mL respectively, the differences of results were statistically significant(P<0.05).Under the effect of chemotactic agent,the directional migration capability of neutrophils in control group 1, 0.3 mg/kg MK-801 treatment group 1 and 0.6 mg/kg MK-801 treatment group 1 were(0.85±0.11) radian,(1.00±0.11) radian,(0.96±0.10) radian respectively (P<0.05); the migration velocities of neutrophils were (0.09±0.02) μm/s,(0.12±0.01) μm/s,(0.14±0.01) μm/s respectively (P<0.05);the migration distances of neutrophils were (94.26±0.02) μm,(134.61±0.01) μm,(156.19±0.01) μm respectively(P<0.05). CONCLUSION Compared with neutrophils in peritoneal cavity of control group, the neutrophils in peritoneal cavity of schizophrenic rats have stronger chemotactic movement ability.
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Affiliation(s)
- N Bai
- Department of Pharmceutical,Jinzhou Medical University, Jinzhou 121000, Liaoning, China;Peking University Medical and Health Analysis Center,Beijing 100191,China
| | - L F Yang
- Peking University Medical and Health Analysis Center,Beijing 100191,China;Department of Chemical Biology,Peking University School of Parmaceutical Sciences,Beijing 100191,China
| | - L H An
- Peking University Medical and Health Analysis Center,Beijing 100191,China
| | - W Wang
- Peking University Medical and Health Analysis Center,Beijing 100191,China
| | - Y Q Li
- Peking University Medical and Health Analysis Center,Beijing 100191,China;Department of Chemical Biology,Peking University School of Parmaceutical Sciences,Beijing 100191,China
| | - Y Sheng
- Peking University Medical and Health Analysis Center,Beijing 100191,China;Department of Chemical Biology,Peking University School of Parmaceutical Sciences,Beijing 100191,China
| | - T Wang
- Peking University Medical and Health Analysis Center,Beijing 100191,China;Department of Chemical Biology,Peking University School of Parmaceutical Sciences,Beijing 100191,China
| | - H K Li
- Department of Basic Science, Jinzhou Medical University, Jinzhou 121000, Liaoning, China
| | - L Yuan
- Peking University Medical and Health Analysis Center,Beijing 100191,China;Department of Chemical Biology,Peking University School of Parmaceutical Sciences,Beijing 100191,China
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Abstract
The human brain is an extremely complex system of 1010-1011 neurons. To construct brain-like neuromorphic hardware, the neuron unit should be implemented effectively. Here, we report a neuron transistor based on a MoS2 flake, which has summation and threshold functions similar to biological neurons and may act as a basic neuron unit in neuromorphic hardware. The neuron transistor is composed of a floating gate and two control gates. A heavily doped silicon substrate serves as the floating gate, while the two control gates are capacitively coupled with the floating gate. The neuron transistor can be well controlled by the two control gates individually or simultaneously. The drain current can be modulated by the input voltages at the control gates. While the current response of the neuron transistor has a large dependence on the magnitude of the input signal, it shows little dependence on the frequency of the input signal. To demonstrate the potential neuromorphic application of the neuron transistor, functions including abacus-like function, AND logic and OR logic are realized in the neuron transistor.
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Affiliation(s)
- S G Hu
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China
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Li HK, Urban E, Noel C, Chuang A, Xia Y, Ransford A, Hemmerling B, Wang Y, Li T, Häffner H, Zhang X. Realization of Translational Symmetry in Trapped Cold Ion Rings. Phys Rev Lett 2017; 118:053001. [PMID: 28211726 DOI: 10.1103/physrevlett.118.053001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Indexed: 06/06/2023]
Abstract
We crystallize up to 15 ^{40}Ca^{+} ions in a ring with a microfabricated silicon surface Paul trap. Delocalization of the Doppler laser-cooled ions shows that the translational symmetry of the ion ring is preserved at millikelvin temperatures. By characterizing the collective motion of the ion crystals, we identify homogeneous electric fields as the dominant symmetry-breaking mechanism at this energy scale. With increasing ion numbers, such detrimental effects are reduced. We predict that, with only a ten-ion ring, uncompensated homogeneous fields will not break the translational symmetry of the rotational ground state. This experiment opens a door towards studying quantum many-body physics with translational symmetry at the single-particle level.
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Affiliation(s)
- Hao-Kun Li
- Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA
| | - Erik Urban
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Crystal Noel
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Alexander Chuang
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Yang Xia
- Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA
| | - Anthony Ransford
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Boerge Hemmerling
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Yuan Wang
- Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Tongcang Li
- Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA
| | - Hartmut Häffner
- Department of Physics, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
| | - Xiang Zhang
- Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
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Li HK, Chen TP, Hu SG, Li XD, Liu Y, Lee PS, Wang XP, Li HY, Lo GQ. Highly spectrum-selective ultraviolet photodetector based on p-NiO/n-IGZO thin film heterojunction structure. Opt Express 2015; 23:27683-27689. [PMID: 26480430 DOI: 10.1364/oe.23.027683] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ultraviolet photodetector with p-n heterojunction is fabricated by magnetron sputtering deposition of n-type indium gallium zinc oxide (n-IGZO) and p-type nickel oxide (p-NiO) thin films on ITO glass. The performance of the photodetector is largely affected by the conductivity of the p-NiO thin film, which can be controlled by varying the oxygen partial pressure during the deposition of the p-NiO thin film. A highly spectrum-selective ultraviolet photodetector has been achieved with the p-NiO layer with a high conductivity. The results can be explained in terms of the "optically-filtering" function of the NiO layer.
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Abstract
We propose a class of spectral singularities emerging from the coincidence of two independent singularities with highly directional responses. These spectral singularities result from resonance trapping induced by the interplay between parity-time symmetry and Fano resonances. At these singularities, while the system is reciprocal in terms of a finite transmission, a simultaneous infinite reflection from one side and zero reflection from the opposite side can be realized.
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Affiliation(s)
- Hamidreza Ramezani
- NSF Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA
| | - Hao-Kun Li
- NSF Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA
| | - Yuan Wang
- NSF Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA
| | - Xiang Zhang
- NSF Nanoscale Science and Engineering Center, University of California, Berkeley, California 94720, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Harding V, Fenu E, Medani H, Shaboodien R, Ngan S, Li HK, Burt R, Diamantis N, Tuthill M, Blagden S, Gabra H, Urch CE, Moser S, Agarwal R. Safety, cost-effectiveness and feasibility of daycase paracentesis in the management of malignant ascites with a focus on ovarian cancer. Br J Cancer 2012; 107:925-30. [PMID: 22878372 PMCID: PMC3464770 DOI: 10.1038/bjc.2012.343] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 06/24/2012] [Accepted: 06/26/2012] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Paracentesis for malignant ascites is usually performed as an in-patient procedure, with a median length of stay (LoS) of 3-5 days, with intermittent clamping of the drain due to a perceived risk of hypotension. In this study, we assessed the safety of free drainage and the feasibility and cost-effectiveness of daycase paracentesis. METHOD Ovarian cancer admissions at Hammersmith Hospital between July and October 2009 were audited (Stage 1). A total of 21 patients (Stage 2) subsequently underwent paracentesis with free drainage of ascites without intermittent clamping (October 2010-January 2011). Finally, 13 patients (19 paracenteses, Stage 3), were drained as a daycase (May-December 2011). RESULTS Of 67 patients (Stage 1), 22% of admissions and 18% of bed-days were for paracentesis, with a median LoS of 4 days. In all, 81% of patients (Stage 2) drained completely without hypotension. Of four patients with hypotension, none was tachycardic or symptomatic. Daycase paracentesis achieved complete ascites drainage without complications, or the need for in-patient admission in 94.7% of cases (Stage 3), and cost £954 compared with £1473 for in-patient drainage. CONCLUSIONS Free drainage of malignant ascites is safe. Daycase paracentesis is feasible, cost-effective and reduces hospital admissions, and potentially represents the standard of care for patients with malignant ascites.
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Affiliation(s)
- V Harding
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - E Fenu
- National Clinical Guideline Centre, Royal College of Physicians, London NW1 4L, UK
| | - H Medani
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - R Shaboodien
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - S Ngan
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - H K Li
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - R Burt
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - N Diamantis
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - M Tuthill
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - S Blagden
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - H Gabra
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - C E Urch
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - S Moser
- Department of Radiology, Hammersmith Hospital, Imperial College, Du Cane Road, London W12 0HS, UK
| | - R Agarwal
- Department of Oncology, Hammersmith Hospital Campus, Imperial College London, Du Cane Road, London W12 0NN, UK
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Li HK, Linghu EQ. Endoscopic vs. laparoscopic gastrojejunostomy for duodenal obstruction: a randomized study in a porcine model. Endoscopy 2012; 44:634. [PMID: 22638787 DOI: 10.1055/s-0032-1309392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
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Shalchi Z, Saso S, Li HK, Rowlandson E, Tennant RC. In response – additional support to high-risk patients can reduce hospital readmissions. Clin Med (Lond) 2010. [DOI: 10.7861/clinmedicine.10-2-202a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
It is a concern that increasing pressure to diagnose, treat and discharge patients rapidly is leading to unacceptably high readmission rates. Readmissions were studied over a two-month period. Patients were identified through the hospital coding system, and electronic discharge summaries provided details of each admission. In total, 69 readmissions were identified, representing 4.34% of medical admissions. Readmitted patients were older than those with single admissions (median age 75 and 71 years, respectively; p < 0.05). Initial length of stay was greater in those patients who would go on to be readmitted (median six days; single admission, two days; p < 0.0001). Seventy-one per cent of readmissions were deemed avoidable, with discharge before conclusive therapy being the leading factor implicated (56%). Readmission is more likely in older patients with complex care needs. Rapid throughput of patients is not associated with readmission. The majority of readmissions can potentially be avoided with judicious medical care.
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Affiliation(s)
- Z Shalchi
- Acute Medical Assessment Unit, Northwick Park Hospital, North West London Hospitals NHS Trust, Middlesex
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Li HK. [Malaria survillance in Sance County, Guizhou Province during 1998-9]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2003; 19:61. [PMID: 12572033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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18
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Zhang ZY, Yang CL, Li HK. [Clinical analysis of 70 cases of cysticercosis]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2003; 18:332. [PMID: 12567604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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19
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Zhao GZ, Li HK, Liu Y, Mu W. [Study of the charge transfer reaction between clotrimazolum and alizarin red]. Guang Pu Xue Yu Guang Pu Fen Xi 2001; 21:733-734. [PMID: 12945348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The charge transfer reaction between clotrimazolum and alizarin red was studied spectrophotometrically. The reaction was achieved with good results in water-acetone solution. The apparent molar absorptivity is 8.7 x 10(3) L.mol-1.cm-1 at 525 nm. The Beer's law was obeyed in the range of 0-100 micrograms.mL-1 of clotrimazolum. The composition of the complex is 1:1. The proposed method has been applied successfully to the determination of clotrimazolum tablets.
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Affiliation(s)
- G Z Zhao
- Jinzhou Medical College, Jinzhou 121000, China
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Yu D, Wang ZH, Cheng SB, Li HK, Chan HB, Chew EC. The effect of arsenic trioxide on the expression of Hsc and HNF4 in nuclear matrix proteins in HepG2 cells. Anticancer Res 2001; 21:2553-9. [PMID: 11724321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Anticancer agents interfere with the proliferation and survival of tumor cells by a variety of mechanisms. An important factor in the development of a cytotoxic effect by certain anticancer agents is the localization of drug-induced lesions within the cell nucleus. Drug-target interactions at the level of nuclear matrix (NM) may be critical events in the induction of cell death by some of these agents. Arsenic trioxide (As2O3) was identified as a very potent anti-leukemic agent by inducing apoptosis. The present study shows that As2O3 significantly inhibits the growth of hepatoblastoma cell line, HepG2, changes the composition of nuclear matrix proteins and reduces the expression of Hsc 70 and HNF4 in HepG2, which in turn initiate a cascade of events that compromise multiple nuclear functions and, ultimately, cell survival.
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Affiliation(s)
- D Yu
- Department of Surgery, Shenzhen Central Hospital, China
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Wang ZH, Yu D, Li HK, Chow VW, Ng CC, Chan HB, Cheng SB, Chew EC. Alteration of nuclear matrix protein composition of neuroblastoma cells after arsenic trioxide treatment. Anticancer Res 2001; 21:493-8. [PMID: 11299786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The aims of the present study were to assess the effects of arsenic trioxide on the nuclear matrix protein profiles of mouse neuroblastoma cells. Arsenic trioxide induces apoptosis of acute promyelocytic leukemia cells. Our results demonstrated that 2 microM As2O3 could significantly inhibit the growth of Neuro-2a cells. As early as 24 hours after As2O3 treatment, we began to observe the alteration of nuclear matrix proteins and apoptosis in tumor cells by TUNEL assay but not by DNA ladder. An increase expression of Hsc in nuclear matrix proteins of 2 microM As2O3 treated cells was also noted. Our results also showed that before a mass range of apoptosis occurred, the composition of nuclear matrix proteins had altered. Hence the alteration of nuclear matrix proteins, such as increased expression of Hsc, may be a sensitive indicator for the detection of early apoptosis.
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Affiliation(s)
- Z H Wang
- Department of Anatomy, Chinese University of Hong Kong, China
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Abstract
OBJECTIVES Glaucoma is a major cause of blindness. More than 80,000 Americans suffer permanent vision loss from the disease. Widespread screening is fundamental in limiting the incidence of glaucoma-associated blindness. This pilot study explored the use of stereo digital images taken at a primary care center for telemedicine review by an off-site specialist as a means of screening for glaucoma. MATERIALS AND METHODS Thirty-two diabetic patients were screened at a family medicine clinic. None had previously been diagnosed with glaucoma. A senior optometry student took stereoscopic digital and 35-mm optic disc photographs with a nonmydriatic retinal camera. The digital images were forwarded to a remote ophthalmologist for review. The conventional color stereo slide pairs of the same eyes were subsequently reviewed for comparison. Agreement on signs of glaucomatous disc changes between the two imaging systems was analyzed. RESULTS Twenty-six of 32 eyes' digital and 35-mm photographs were analyzed. Six of 32 eyes (18.8%) could not be compared due to lack of matching 35-mm slides or digital images. Out of 26 eyes, lamina cribosa visibility was undeterminable in 8 eyes' digital images and 3 other eyes' 35-mm slides. Agreement among digital images and 35-mm slides of the remaining eyes was: 100%-vertical elongation, barring of vessels, bayoneting of vessels, and drance hemorrhage; 96.2%-focus notching of rim and rim pallor; 93.3%-lamina cribosa visability; 92. 3%-overpass cupping; 88.5%-focal enlargement; 84.6%-parapapillary halo; 80%-nerve fiber visibility; 65.4%-parapapillary atrophy. Parapapillary halo (p = 0.046) and nerve fiber layer visibility (p = 0.18) were detected on some 35-mm slides but not seen on matching digital views. CONCLUSION Evaluations of cup-to-disc ratio (C/D) using both methods were in general agreement. However, some digital images were noted as too dark for assessing fine glaucomatous disc changes. Stereo digital images taken with a nonmydriatic camera by nonophthalmic photographers is a promising alternative for glaucoma screening in primary care settings. Telemedicine offers efficient communications with off-site glaucoma specialists. A larger study population is necessary to determine the overall effectiveness of using stereo digital imagery and teleophthalmology for glaucoma screening.
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Affiliation(s)
- H K Li
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, USA
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Hao CF, Wang ZH, Yun JP, Li HK, Ng CC, To KF, Chew-Cheng SB, Chew EC. The measurement of AgNORs in human glioma cells. Anticancer Res 2000; 20:1599-602. [PMID: 10928077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Sixty gliomas obtained by neurosurgical resections were examined. Paraffin blocks were retrieved from pathological files of the Second Affiliated Hospital in Guangzhou Medical College. The methods of argyrophilic technique for AgNORs staining, and Image Analysis System for measurement of AgNORs were used. Six parameters, which included hcount, count, narea, agnrea, agpern and agperc were used to correlated well with histopathological grades (compared grade 2 & 3, grade 3 & 4, and grade 2 & 4, respectively). We concluded that AgNORs is useful in evaluating proliferative activity and assessing the malignancy of human gliomas. It may also be used as a target for anti-neoplastic drugs in the treatment of gliomas.
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Affiliation(s)
- C F Hao
- Department of Anatomy, Chinese University of Hong Kong, Shatin, NT, Hong Kong
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Abstract
OBJECTIVE To determine whether the sub-Tenon's parabulbar approach for local anesthesia is a safe and effective choice for posterior segment surgery. DESIGN Prospective, noncomparative case series. PARTICIPANTS Two hundred seventy-six consecutive patients underwent posterior segment surgery at the University of Texas Medical Branch. INTERVENTION Two hundred patients received sub-Tenon's parabulbar anesthesia containing an 11 -ml mixture of 5-ml 2% lidocaine (Xylocaine), 5-ml 0.5% bupivacaine (Marcaine), and 1 ml of 150 hyaluronidase (Wydase) units as primary anesthesia. The method did not involve a separate transcutaneous lid nerve or subconjunctival injection. MAIN OUTCOME MEASURES The proportion of cases receiving supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both) was estimated. Its relationship to duration of surgery and surgical procedures deemed painful was assessed. Surgery lasting 3 hours or more was considered a long duration. Both scleral buckle and cryotherapy were considered painful procedures. The proportion of cases receiving additional local anesthesia preoperatively was also evaluated. Complications associated with sub-Tenon's parabulbar injection were monitored. RESULTS There were 101 instances of patients receiving additional anesthesia. Nineteen received additional preoperative sub-Tenon's anesthesia, 12 received intraoperative local anesthesia supplementation, and 70 received intravenous medication. Of these 70, 19 required what the authors defined as a significant amount of intravenous medication, three of whom also received intraoperative local anesthesia supplementation. Consequently, 28 of 200 patients (14%; 95% confidence interval: 9.5, 19.6) received supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both). The proportion of cases receiving supplementation was directly related to duration of surgery. Patients involved in longer cases (51.7% vs. 7.6%; P < 0.001) and those involved in more painful procedures (48.2% vs. 8.7%; P < 0.001) were more likely to receive supplementation. Adjusting for surgery duration, a greater proportion of patients undergoing painful procedures required supplementation (31.3% vs. 0.5% for surgery < 3 hours, P = 0.003; 72.7% vs. 38.9% for surgery > or = 3 hours, P = 0.13). No associated ocular or systemic complications were observed. CONCLUSIONS The results of this large study demonstrate that a single injection of sub-Tenon's anesthesia is relatively safe and effective for achieving local anesthesia during vitrectomies, with or without other intraocular procedures, lasting less than 3 hours. Other types of posterior segment surgery may require supplementation if they are more painful procedures, such as scleral buckle or cryotherapy, or last longer than 3 hours.
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Affiliation(s)
- H K Li
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston 77555-0787, USA
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Abstract
Technology to create and move multimedia medical information is creating alternatives to physically transporting patients and health care professionals. Teletechnology is a physician extender, both supplementing and reinventing traditional health care delivery systems. The potential of comprehensive teleophthalmology is compelling. This article provides a historical perspective of telemedicine, describes various teleophthalmology systems, and surveys teleophthalmology in clinical consultation, research, and education programs around the world. It also discusses basic issues in applying teleophthalmology to public health.
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Affiliation(s)
- H K Li
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston 77555-0787, USA
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Schiffman JS, Li HK, Tang RA. Telemedicine enters eye care: practical experience. J Ophthalmic Nurs Technol 1998; 17:102-6. [PMID: 9677981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
1. A combination of store-and-forward technology and videoconferencing technology can be used in eye care and other medical specialties. 2. Bandwidth is a rate-limiting factor for obtaining a high-resolution, real-time image. 3. Protocols, clinical and technical, must be used to implement telemedicine in an efficient and high-quality manner.
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Abstract
A 30-year-old man with bilateral congenital aniridia presented with a subluxated cataract in the right eye. He wore a soft contact lens for aphakic correction in the fellow eye after lensectomy for a subluxated cataract. We performed pars plana lensectomy and vitrectomy with implantation of a transscleral ciliary sulcus fixated posterior chamber intraocular lens in the right eye. Good postoperative visual acuity was obtained.
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Affiliation(s)
- E I Segal
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston 77555, USA
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Abstract
PURPOSE The purpose of the study is to report on a 34-year-old woman with Susac syndrome who presented on two separate occasions with visual acuity loss from a recurrent branch retinal artery occlusion and underwent hyperbaric oxygen treatment with favorable outcome. METHODS Visual acuity was 20/400 in the left eye and count fingers in the right eye after separate occlusive events. The patient underwent hyperbaric oxygen treatment on each occasion of visual acuity loss. The patient subsequently was diagnosed with Susac syndrome (microangiopathy of the retina, brain, and middle ear). The authors present visual fields, photographs, angiograms, and ancillary tests documenting diagnosis and course of treatment. RESULTS On each occasion, visual acuity improved to 20/25 during and was maintained after hyperbaric oxygen treatment. Visual fields showed improvement immediately after treatment. CONCLUSION This is the first report of hyperbaric oxygen treatment for Susac syndrome. Dramatic post-treatment visual field and acuity changes suggest benefit of treatment. Hyperbaric oxygen treatment can be considered a treatment option for visual complications of this syndrome. Susac syndrome should be included in the differential diagnosis of recurrent branch retinal artery occlusion.
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Affiliation(s)
- H K Li
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston 77555, USA
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Abstract
We present a rare case of congenital cystic eye associated with holoprosencephaly and tetralogy of Fallot. The orbital cyst was diagnosed preoperatively by computed tomography (CT) scan, and we present the first magnetic resonance imaging (MRI) finding in such a disorder. The orbital cyst expanded over 7 months of follow-up. The cyst was excised in toto and studied by immunohistochemistry, and its content was analyzed biochemically. The patient achieved an acceptable cosmetic result.
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Affiliation(s)
- A M Mansour
- Department of Ophthalmology, American University of Beirut, Lebanon
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Abstract
Little is known about the natural history of cytomegalovirus (CMV) optic neuritis in the acquired immunodeficiency syndrome. We analyzed the clinical course of CMV optic neuritis in 30 consecutive subjects (35 eyes), and compared the survival of patients with CMV optic neuritis to that of a group having CMV retinitis alone, with both groups matched for ganciclovir therapy. Four untreated eyes had a median final visual acuity of no light perception. The median final visual acuity was 20/100 in treated subjects with a mean follow-up of 6.6 months. Following ganciclovir treatment, 2 eyes showed visual improvement, 17 eyes had unchanged visual acuity, and 12 eyes had marked drop in acuity. Relapse occurred in 4 subjects maintained on single-dose ganciclovir, and was controlled on double-dose ganciclovir. Survival was similar in the group of CMV retinitis alone versus the group of CMV optic neuritis with retinitis. Early recognition and therapy of CMV optic neuritis protects against irreversible visual loss. CMV optic neuritis does not carry a worse prognosis for survival than CMV retinitis alone.
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Affiliation(s)
- A M Mansor
- Department of Ophthamology, University of Texas Medical Branch, Galveston 77555-0787, USA
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31
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Abstract
Six patients with the acquired immunodeficiency syndrome had frosted periphlebitis associated with large areas of cytomegalovirus retinitis. Following the administration of ganciclovir, periphlebitis resolved within 2-6 weeks concomitant with quieting of cytomegalovirus retinitis. Frosted retinal periphlebitis in the acquired immunodeficiency syndrome is associated with cytomegalovirus retinitis in North America. Medical treatment of cytomegalovirus retinitis leads to resolution of the periphlebitis without the need for systemic corticosteroids.
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Affiliation(s)
- A M Mansour
- Department of Ophthalmology, University of Texas Medical Branch, Galveston 77555-0787
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Li HK, Ma WZ, Liao J. [Changes in the relaxation and compliance of the left ventricle in cardiomyopathy]. Zhonghua Nei Ke Za Zhi 1989; 28:18-21, 61. [PMID: 2737031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In order to study the left ventricular diastolic events in cardiomyopathy, carotid pulse tracing, electrocardiogram, phonocardiogram and apexcardiogram with its first derivatives (dA/dt) were simultaneously recorded in 240 normal subjects, 30 patients with dilated cardiomyopathy (DCM) and 44 patients with hypertrophic cardiomyopathy (HCM). Total relaxation time (TRT), total relaxation time index (TRTI), the ratio of A wave to total diastolic amplitude in apexcardiogram (A/D), diastolic amplitude time index (DATI), the ratio of RF wave in apexcardiogram to the total amplitude of apex tracing (F/H) and the variables reflecting the diastolic properties were measured to evaluate the left ventricular relaxation and compliance. Meanwhile, two variables reflecting the contractile ability of the left ventricle were measured in order to compare with the diastolic events. The results demonstrated that in normal subjects relaxation and compliance of the left ventricle showed a tendency of natural "decay" with aging and in patients with DCM and HCM these were significantly decreased, especially in patients with HCM. A/D, which reflects the left ventricular compliance, was increased in patients with HCM as compared with normal subjects (P less than 0.01) and also with patients with DCM. It means that a greater A/D is in favor of the diagnosis of HCM rather than DCM. In addition to abnormal diastolic events, systolic dysfunction, as evidenced by remarkable abnormalities of the contractile variables (PEP/LVET and R-dA/dt.I), was found as well in patients with DCM.
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Li HK, Ma WZ, Liao J. [Left ventricular relaxation and compliance in normal subjects]. Zhonghua Xin Xue Guan Bing Za Zhi 1988; 16:92-4, 127. [PMID: 3197603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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