The two-photon absorption (2PA) and photophysics of heptamethine dyes featuring cyanine or dipolar electronic structures have been compared for the first time. The perfectly delocalized cyanine system is classically characterized by a two-photon transition matching the vibronic component of its lower energy absorption band. The dipolar species is generated by ion-pairing with a hard counterion in a non-dissociating solvent and displays significant modifications oft he optical properties, including a significant hypochromic shift of absorption, weaker emission and 2PA matching the lower energy transition, thus revealing symmetry breaking within the polymethine electronic structure.
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http://dx.doi.org/10.1002/cphc.202000731 | DOI Listing |
Chemphyschem
January 2025
University of Leeds, School of Chemistry, Woodhouse Lane, LS2 9JT, Leeds, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
The orthorhombic structure of FeNbO4, where the Fe and Nb cations are distributed randomly over the octahedral 4c sites, has shown excellent promise as an anode material in solid oxide fuel cells. We have used DFT+U-D2 calculations to explore the adsorption and dissociation of H2 molecules and the formation reaction of water at the (010) and (111) surfaces. Simulations of the surface properties confirmed that the bandgaps are significantly reduced compared to the bulk material.
View Article and Find Full Text PDFStress Health
February 2025
Prevention Science Institute, University of Oregon, Eugene, Oregon, USA.
College students use substances for varied reasons, including to cope with stress. The parasympathetic nervous system (PNS) regulates bodily functions to promote energy conservation (the 'rest and digest' response), and individuals differ in their physiological sensitivity to challenge. It remains unclear whether greater PNS responses (i.
View Article and Find Full Text PDFMater Horiz
January 2025
Center for Nanophotonics, AMOLF, 1098 XG, Amsterdam, The Netherlands.
Hardware neural networks could perform certain computational tasks orders of magnitude more energy-efficiently than conventional computers. Artificial neurons are a key component of these networks and are currently implemented with electronic circuits based on capacitors and transistors. However, artificial neurons based on memristive devices are a promising alternative, owing to their potentially smaller size and inherent stochasticity.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
NIT Rourkela: National Institute of Technology Rourkela, Department of Chemistry, NIT Rourkela, 769008, Rourkela, INDIA.
Certain proteins and synthetic covalent polymers experience aqueous phase transitions, driving functional self-assembly. Herein, we unveil the ability of supramolecular polymers (SPs) formed by G4.Cu+ to undergo heating-induced unexpected aqueous phase transitions.
View Article and Find Full Text PDFMol Cell Biochem
January 2025
Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Luigi Vanvitelli 32, 20133, Milan, Italy.
Neurodegenerative diseases (NDs) are caused by progressive neuronal death and cognitive decline. Epigallocatechin 3-gallate (EGCG) is a polyphenolic molecule in green tea as a neuroprotective agent. This review evaluates the therapeutic effects of EGCG and explores the molecular mechanisms that show its neuroprotective properties.
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