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The structural transformations of graphene defects have been extensively researched through aberration-corrected transmission electron microscopy (AC-TEM) and theoretical calculations. For a long time, a core concept in understanding the structural evolution of graphene defects has been the Stone-Thrower-Wales (STW)-type bond rotation. In this study, we show that undercoordinated atoms induce bond formation and breaking, with much lower energy barriers than the STW-type bond rotation. We refer to them as mediator atoms due to their mediating role in the breaking and forming of bonds. Here, we report the direct observation of mediator atoms in graphene defect structures using AC-TEM and annular dark-field scanning TEM (ADF-STEM) and explain their catalytic role by tight-binding molecular dynamics (TBMD) simulations and image simulations based on density functional theory (DFT) calculations. The study of mediator atoms will pave a new way for understanding not only defect transformation but also the growth mechanisms in two-dimensional materials.
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http://dx.doi.org/10.1126/sciadv.aba4942 | DOI Listing |
Nanoscale Horiz
September 2025
School of Biomedical Engineering, University of Sydney, Darlington 2008, New South Wales, Australia.
Entropy-driven drying-mediated self-assembly of plasmonic nanocrystals (termed "plasmonic atoms") has emerged as a general strategy for fabricating plasmene nanosheets from a wide range of monodisperse nanocrystals. However, extending this approach to binary systems remains challenging due to the complex nanoscale interactions between dissimilar nanocrystal shapes. Here, we introduce a combined enthalpy- and entropy-driven strategy to achieve an orderly mixed two-dimensional (2D) binary nanoassemblies from complementary reacting polymer-ligated nanocrystals.
View Article and Find Full Text PDFMed Oncol
September 2025
Venom and Biotherapeutics Molecules Laboratory, Biotechnology Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
Neuropeptide Y (NPY) and the voltage-gated potassium channel Kv1.3 are closely associated with breast cancer progression and apoptosis regulation, respectively. NPY receptors (NPYRs), which are overexpressed in breast tumors, contribute to tumor growth, migration, and angiogenesis.
View Article and Find Full Text PDFFront Neurosci
August 2025
Cell Signaling Laboratory, Institute of Experimental Medicine, Universidad Central de Venezuela, Caracas, Venezuela.
In our current view of reality, free will hangs on two opposing forces. On one side, we have determinism, which states that everything is already determined by our inner constituents, the atoms and molecules that form our bodies. On the other side, we have quantum mechanics and its view that everything in the quantum world is inherently random and probabilistic.
View Article and Find Full Text PDFFront Psychol
August 2025
Research Center, Institute for Whole Social Science, Northland, New Zealand.
Within the broader topic of women's intuition, the focus of this work is mother-offspring intuition-the enigmatic connection between a mother and her offspring, wherein distress or imminent harm is instantly sensed, even when thousands of miles apart. Instant nonlocal communication irrespective of distance, is known as entanglement in quantum physics, and has been repeatedly verified since the 1970's. Building upon this discovery, a new concept--is postulated to create a two-way micro to macroscale bond of tacit connection between a mother and a fetus, initiated at conception.
View Article and Find Full Text PDFACS Nano
September 2025
Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
Transition metal chalcogenides (TMCs) have garnered significant attention as high-capacity anode materials, yet the unconventional role of the Cu collector meditating atomic-level substitution of metal-site cations by Cu ions during electrochemical cycling remains mechanistically unclear. To address this, herein, Cu-doped MoSe@C ultrathin nanosheets were synthesized via the solvothermal process and carbonization strategies. A systematic investigation was conducted to elucidate the underlying driving forces for Cu substitution at Mo sites and the crucial regulatory effects of solid electrolyte interphase (SEI) formation.
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