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Hwang S, Wu L, Kisslinger K, Yang J, Egerton R, Zhu Y. Secondary-electron imaging of bulk crystalline specimens in an aberration corrected STEM. Ultramicroscopy 2024; 261:113967. [PMID: 38615523 DOI: 10.1016/j.ultramic.2024.113967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 04/03/2024] [Accepted: 04/09/2024] [Indexed: 04/16/2024]
Abstract
Atomic-scale electron microscopy traditionally probes thin specimens, with thickness below 100 nm, and its feasibility for bulk samples has not been documented. In this study, we explore the practicality of scanning transmission electron microscope (STEM) imaging with secondary electrons (SE), using a silicon-wedge specimen having a maximum thickness of 18 μm. We find that the atomic structure is present in the entire thickness range of the SE images although the background intensity increases moderately with thickness. The consistent intensity of secondary electron (SE) images at atomic positions and the modest increase in background intensity observed in silicon suggest a limited contribution from SEs generated by backscattered electrons, a conclusion supported by our multislice calculations. We conclude that achieving atomic resolution in SE imaging for bulk specimens is indeed attainable using aberration-corrected STEM and an aberration-corrected scanning electron microscope (SEM) may have the capacity for atomic-level resolution, holding great promise for future strides in materials research.
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Affiliation(s)
- Sooyeon Hwang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, New York 11973, United States
| | - Lijun Wu
- Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory, New York 11973, United States
| | - Kim Kisslinger
- Center for Functional Nanomaterials, Brookhaven National Laboratory, New York 11973, United States
| | - Judith Yang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, New York 11973, United States
| | - Ray Egerton
- Physics Department, University of Alberta, Edmonton T1W 2E2, Canada
| | - Yimei Zhu
- Condensed Matter Physics & Materials Science Department, Brookhaven National Laboratory, New York 11973, United States.
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San Gabriel ML, Qiu C, Yu D, Yaguchi T, Howe JY. Simultaneous secondary electron microscopy in the scanning transmission electron microscope with applications for in situ studies. Microscopy (Oxf) 2024; 73:169-183. [PMID: 38334743 DOI: 10.1093/jmicro/dfae007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 12/09/2023] [Accepted: 02/05/2024] [Indexed: 02/10/2024] Open
Abstract
Scanning/transmission electron microscopy (STEM) is a powerful characterization tool for a wide range of materials. Over the years, STEMs have been extensively used for in situ studies of structural evolution and dynamic processes. A limited number of STEM instruments are equipped with a secondary electron (SE) detector in addition to the conventional transmitted electron detectors, i.e. the bright-field (BF) and annular dark-field (ADF) detectors. Such instruments are capable of simultaneous BF-STEM, ADF-STEM and SE-STEM imaging. These methods can reveal the 'bulk' information from BF and ADF signals and the surface information from SE signals for materials <200 nm thick. This review first summarizes the field of in situ STEM research, followed by the generation of SE signals, SE-STEM instrumentation and applications of SE-STEM analysis. Combining with various in situ heating, gas reaction and mechanical testing stages based on microelectromechanical systems (MEMS), we show that simultaneous SE-STEM imaging has found applications in studying the dynamics and transient phenomena of surface reconstructions, exsolution of catalysts, lunar and planetary materials and mechanical properties of 2D thin films. Finally, we provide an outlook on the potential advancements in SE-STEM from the perspective of sample-related factors, instrument-related factors and data acquisition and processing.
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Affiliation(s)
- Mia L San Gabriel
- Department of Materials Science and Engineering, University of Toronto, 184 College St, Toronto, ON M5S 3E4,Canada
| | - Chenyue Qiu
- Department of Materials Science and Engineering, University of Toronto, 184 College St, Toronto, ON M5S 3E4,Canada
| | - Dian Yu
- Department of Materials Science and Engineering, University of Toronto, 184 College St, Toronto, ON M5S 3E4,Canada
| | - Toshie Yaguchi
- Electron Microscope Systems Design Department, Hitachi High-Tech Corporation, 552-53 shinko-cho, Hitachinaka-shi, Ibaraki-ken 312-8504, Japan
| | - Jane Y Howe
- Department of Materials Science and Engineering, University of Toronto, 184 College St, Toronto, ON M5S 3E4,Canada
- Department of Chemical Engineering, University of Toronto, 200 College St, Toronto, ON M5T 3E5, Canada
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Schreiner TG, Menéndez-González M, Adam M, Popescu BO, Szilagyi A, Stanciu GD, Tamba BI, Ciobanu RC. A Nanostructured Protein Filtration Device for Possible Use in the Treatment of Alzheimer's Disease-Concept and Feasibility after In Vivo Tests. Bioengineering (Basel) 2023; 10:1303. [PMID: 38002427 PMCID: PMC10669467 DOI: 10.3390/bioengineering10111303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/01/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD), along with other neurodegenerative disorders, remains a challenge for clinicians, mainly because of the incomplete knowledge surrounding its etiology and inefficient therapeutic options. Considering the central role of amyloid beta (Aβ) in the onset and evolution of AD, Aβ-targeted therapies are among the most promising research directions. In the context of decreased Aβ elimination from the central nervous system in the AD patient, the authors propose a novel therapeutic approach based on the "Cerebrospinal Fluid Sink Therapeutic Strategy" presented in previous works. This article aims to demonstrate the laborious process of the development and testing of an effective nanoporous ceramic filter, which is the main component of an experimental device capable of filtrating Aβ from the cerebrospinal fluid in an AD mouse model. METHODS First, the authors present the main steps needed to create a functional filtrating nanoporous ceramic filter, which represents the central part of the experimental filtration device. This process included synthesis, functionalization, and quality control of the functionalization, which were performed via various spectroscopy methods and thermal analysis, selectivity measurements, and a biocompatibility assessment. Subsequently, the prototype was implanted in APP/PS1 mice for four weeks, then removed, and the nanoporous ceramic filter was tested for its filtration capacity and potential structural damages. RESULTS In applying the multi-step protocol, the authors developed a functional Aβ-selective filtration nanoporous ceramic filter that was used within the prototype. All animal models survived the implantation procedure and had no significant adverse effects during the 4-week trial period. Post-treatment analysis of the nanoporous ceramic filter showed significant protein loading, but no complete clogging of the pores. CONCLUSIONS We demonstrated that a nanoporous ceramic filter-based system that filtrates Aβ from the cerebrospinal fluid is a feasible and safe treatment modality in the AD mouse model. The presented prototype has a functional lifespan of around four weeks, highlighting the need to develop advanced nanoporous ceramic filters with anti-biofouling properties to ensure the long-term action of this therapy.
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Affiliation(s)
- Thomas Gabriel Schreiner
- Faculty of Medicine, University of Medicine and Pharmacy “Carol Davila”, 050474 Bucharest, Romania
- Faculty of Medicine, University of Medicine and Pharmacy “Gr. T. Popa”, 700115 Iasi, Romania
- Department of Electrical Measurements and Materials, Faculty of Electrical Engineering and Information Technology, Gheorghe Asachi Technical University of Iasi, 700050 Iasi, Romania
| | - Manuel Menéndez-González
- Department of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Department of Neurology, Hospital Universitario Central de Asturias, 33006 Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias, 33006 Oviedo, Spain
| | - Maricel Adam
- Department of Electrical Measurements and Materials, Faculty of Electrical Engineering and Information Technology, Gheorghe Asachi Technical University of Iasi, 700050 Iasi, Romania
| | - Bogdan Ovidiu Popescu
- Faculty of Medicine, University of Medicine and Pharmacy “Carol Davila”, 050474 Bucharest, Romania
- Neurology Department, Colentina Clinical Hospital, 020125 Bucharest, Romania
- Laboratory of Cell Biology, Neurosciences and Experimental Myology, ‘Victor Babes’ National Institute of Pathology, 050096 Bucharest, Romania
| | - Andrei Szilagyi
- Advanced Research and Development Center for Experimental Medicine (CEMEX), “Grigore T. Popa” University of Medicine and Pharmacy, Universitatii Str., No. 16, 700155 Iasi, Romania
| | - Gabriela Dumitrita Stanciu
- Advanced Research and Development Center for Experimental Medicine (CEMEX), “Grigore T. Popa” University of Medicine and Pharmacy, Universitatii Str., No. 16, 700155 Iasi, Romania
| | - Bogdan Ionel Tamba
- Faculty of Medicine, University of Medicine and Pharmacy “Gr. T. Popa”, 700115 Iasi, Romania
- Advanced Research and Development Center for Experimental Medicine (CEMEX), “Grigore T. Popa” University of Medicine and Pharmacy, Universitatii Str., No. 16, 700155 Iasi, Romania
| | - Romeo Cristian Ciobanu
- Department of Electrical Measurements and Materials, Faculty of Electrical Engineering and Information Technology, Gheorghe Asachi Technical University of Iasi, 700050 Iasi, Romania
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Hotz MT, Martis J, Radlicka T, Bacon NJ, Dellby N, Lovejoy TC, Quillin SC, Hwang HY, Singh P, Krivanek OL. Atomic Resolution SE Imaging in a 30-200 keV Aberration-corrected UHV STEM. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:2064-2065. [PMID: 37612905 DOI: 10.1093/micmic/ozad067.1068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- M T Hotz
- Nion R&D, 11511 NE 118th St, Kirkland, WA, USA
| | - J Martis
- Nion R&D, 11511 NE 118th St, Kirkland, WA, USA
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - T Radlicka
- Institute of Scientific Instruments of CAS, Královopolská 147, Brno, Czech Republic
| | - N J Bacon
- Nion R&D, 11511 NE 118th St, Kirkland, WA, USA
| | - N Dellby
- Nion R&D, 11511 NE 118th St, Kirkland, WA, USA
| | - T C Lovejoy
- Nion R&D, 11511 NE 118th St, Kirkland, WA, USA
| | - S C Quillin
- Nion R&D, 11511 NE 118th St, Kirkland, WA, USA
| | - H Y Hwang
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - P Singh
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - O L Krivanek
- Nion R&D, 11511 NE 118th St, Kirkland, WA, USA
- Department of Physics, Arizona State University, Tempe, AZ, USA
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Egerton R, Watanabe M. Spatial Resolution in Transmission Electron Microscopy. Micron 2022; 160:103304. [DOI: 10.1016/j.micron.2022.103304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/05/2022] [Accepted: 05/19/2022] [Indexed: 10/18/2022]
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