Near-infrared-to-visible second harmonic generation from air-stable two-dimensional polar gallium and indium metals is described. The photonic properties of 2D metals, including the largest second-order susceptibilities reported for metals (approaching 10 nm/V), are determined by the atomic-level structure and bonding of two-to-three-atom-thick crystalline films. The bond character evolved from covalent to metallic over a few atomic layers, changing the out-of-plane metal-metal bond distances by approximately ten percent (0.2 Å), resulting in symmetry breaking and an axial electrostatic dipole that mediated the large nonlinear response. Two different orientations of the crystalline metal atoms, corresponding to lateral displacements <2 Å, persisted in separate micrometer-scale terraces to generate distinct harmonic polarizations. This strong atomic-level structure-property interplay suggests metal photonic properties can be controlled with atomic precision.
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http://dx.doi.org/10.1021/acs.nanolett.0c03481 | DOI Listing |
Prog Biomed Eng (Bristol)
December 2024
School of Biomedical Engineering, The Key Laboratory of Advanced Interdisciplinary Studies, The First Affiliated Hospital, Guangzhou Institute of Cancer Research, the Affiliated Cancer Hospital, Guangzhou Medical University, Guangzhou 510260, People's Republic of China.
Since the concept of aggregation-induced emission (AIE) was first coined by Tang and co-workers, AIE-active luminogens (AIEgens) have drawn widespread attention among chemists and biologists due to their unique advantages such as high fluorescence efficiency, large Stokes shift, good photostability, low background noise, and high biological visualization capabilities in the aggregated state, surpassing conventional fluorophores. A growing number of AIEgens have been engineered to possess multifunctional properties, including near-infrared emission, two-photon absorption, reactive oxygen species (ROS) generation and photothermal conversion, making them suitable for deep-tissue imaging and phototherapy. AIEgens show great potential in biomedical applicationsand.
View Article and Find Full Text PDFJ Clin Med
November 2024
Department of Restorative Dental Sciences, UCL-Eastman Dental Institute, Medical Faculty, University College London, London WC1E 6DE, UK.
: Female infertility due to unexpected causes exhibits a great challenge for both clinicians and women who are trying to conceive. The present clinical case series study aimed to evaluate the efficacy of multiple wavelengths of red and near-infrared (NIR) laser photobiomodulation (PBM) for increasing the potential of fertility in women and improving reproductive health in unexplained infertility issues. The objectives were to assess the following: (1) any adverse effects; (2) the possibility of producing an effective PBM protocol; (3) and healthy live birth.
View Article and Find Full Text PDFBrain Stimul
December 2024
Beijing Institute for Brain Research, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 102206, China; Chinese Institute for Brain Research, Beijing, 102206, China. Electronic address:
Background: The use of near-infrared lasers for transcranial photobiomodulation (tPBM) offers a non-invasive method for influencing brain activity and is beneficial for various neurological conditions. However, comprehensive quantitative studies on its safety are lacking.
Objective: This study aims to investigate the safety of 1064-nm laser-based tPBM across brain structure, brain function, neural damage, cognitive ability and tolerance.
Adv Exp Med Biol
October 2024
Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan.
BMC Cancer
September 2024
Department of Cardio-Thoracic And Vascular Surgery, Azienda Ospedaliera Universitaria Città della Salute e della Scienza di Torino, Corso Dogliotti, 14, Torino, 10,126, Italy.
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