Abnormal accumulation of brain metals is a key feature of Alzheimer's disease (AD). Formation of amyloid-β plaque cores (APC) is related to interactions with biometals, especially Fe, Cu and Zn, but their particular structural associations and roles remain unclear. Using an integrative set of advanced transmission electron microscopy (TEM) techniques, including spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM), nano-beam electron diffraction, electron holography and analytical spectroscopy techniques (EDX and EELS), we demonstrate that Fe in APC is present as iron oxide (Fe3O4) magnetite nanoparticles. Here we show that Fe was accumulated primarily as nanostructured particles within APC, whereas Cu and Zn were distributed through the amyloid fibers. Remarkably, these highly organized crystalline magnetite nanostructures directly bound into fibrillar Aβ showed characteristic superparamagnetic responses with saturated magnetization with circular contours, as observed for the first time by off-axis electron holography of nanometer scale particles.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4848473 | PMC |
http://dx.doi.org/10.1038/srep24873 | DOI Listing |
Microscopy (Oxf)
January 2025
The Ultramicroscopy Research Center, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan.
The precision in electron holography studies on electrostatic and magnetic fields depends on the image quality of an electron hologram. Enhancing the image quality of electron holograms is essential for the comprehensive analysis of weak electromagnetic fields; however, extended electron beam irradiation can lead to undesirable radiation damage and contamination. Recent studies have demonstrated that noise reduction using the wavelet hidden Markov model (WHMM) can improve the precision of phase analysis for limited thin-foiled crystals.
View Article and Find Full Text PDFJ Struct Biol
January 2025
CEMES-CNRS, Université de Toulouse, I3EM Team, 29 rue Jeanne Marvig B.P, 94347 31055 Toulouse, France. Electronic address:
Transmission electron microscopy, especially at cryogenic temperature, is largely used for studying biological macromolecular complexes. A main difficulty of TEM imaging of biological samples is the weak amplitude contrasts due to electron diffusion on light elements that compose biological organisms. Achieving high-resolution reconstructions implies therefore the acquisition of a huge number of TEM micrographs followed by a time-consuming image analysis.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States.
Controlling materials' composition and structure to selectively adsorb rare earth elements (REE) is critical for better separations. Understanding how local electric potentials affect REE adsorption and how they can be modified via chemical substitution is of fundamental importance. We present calculated mean inner potentials for muscovite and phlogopite micas in excellent agreement with measured values of +10.
View Article and Find Full Text PDFMicrosc Microanal
January 2025
EMAT, University of Antwerp, Groenenborgerlaan 171 2020, Antwerp, Belgium.
The challenge of imaging low-density objects in an electron microscope without causing beam damage is significant in modern transmission electron microscopy. This is especially true for life science imaging, where the sample, rather than the instrument, still determines the resolution limit. Here, we explore whether we have to accept this or can progress further in this area.
View Article and Find Full Text PDFAdv Mater
January 2025
Laboratory of Advanced Materials, Institute of Optoelectronics, Fudan University, Shanghai, 200438, P. R. China.
Metal single atoms (SA)-support interactions inherently exhibit significant electrochemical activity, demonstrating potential in energy catalysis. However, leveraging these interactions to modulate electronic properties and extend application fields is a formidable challenge, demanding in-depth understanding and quantitative control of atomic-scale interactions. Herein, in situ, off-axis electron holography technique is utilized to directly visualize the interactions between SAs and the graphene surface.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!