We report the observation of photo-induced plasmon-phonon coupled modes in the group IV-VI semiconductor PbTe using ultrafast x-ray diffuse scattering at the Linac Coherent Light Source. We measure the near-zone-center excited-state dispersion of the heavily screened longitudinal optical (LO) phonon branch as extracted from differential changes in x-ray diffuse scattering intensity following above bandgap photoexcitation. We suggest that upon photoexcitation, the LO phonon-plasmon coupled (LOPC) modes themselves become coupled to longitudinal acoustic modes that drive electron band shifts via acoustic deformation potentials and possibly to low-energy single-particle excitations within the plasma and that these couplings give rise to displacement-correlations that oscillate in time with a period given effectively by the heavily screened LOPC frequency.
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http://dx.doi.org/10.1063/4.0000133 | DOI Listing |
Dalton Trans
January 2025
Department of Chemistry, Faculty of Science, Cairo University, Gamma Street, Giza, Cairo 12613, Egypt.
The photo-induced CO-releasing properties of the dark-stable complex [RuCl(CO)L] (L = 2-(pyridin-2-yl)quinoxaline) were investigated under 468 nm light exposure in the presence and absence of biomolecules such as histidine, calf thymus DNA and hen egg white lysozyme. The CO release kinetics were consistent regardless of the presence of these biomolecules, suggesting that they did not influence the CO release mechanism. The quinoxaline ligand demonstrated exceptional cytotoxicity against human acute monocytic leukemia cells (THP-1), with evidence of potential DNA damage ascertained by comet assay, while it remained non-toxic to normal kidney epithelial cells derived from African green monkey (Vero) cell lines.
View Article and Find Full Text PDFAnal Sci
December 2024
Department of Biology, University of the Pacific, 3601 Pacific Avenue, Stockton, CA, 95211, USA.
Chemistry
November 2024
Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Province, Shantou University, Shantou, 515063, P. R. China.
We prepared a series fully rigid spiro electron donor-acceptor orthogonal dyads, with closed form of rhodamine (Rho) as electron donor and naphthalene (Np)/anthraquinone (AQ) as electron acceptor, to access the long-lived triplet charge separation (CS) state, via the electron spin control method. We found strong dependency of the photophysical property of the dyads on the amino substitution positions of the Np chromophores in the dyads 1,8-DaNp-Rho and 2,3-DaNp-Rho. Nanosecond transient absorption (ns-TA) spectra show the population of the LE state (lifetime: 47 μs) for 2,3-DaNp-Rho, however, long-lived CS state was observed (τ=0.
View Article and Find Full Text PDFBioorg Med Chem
December 2024
Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, United States. Electronic address:
Tau and α-synuclein (α-syn) are prone-to-aggregate proteins that can be responsible for pathological lesions found in the brains of Alzheimer's disease (AD), Lewy body dementia (LBD), and Parkinson's disease (PD) patients. The early-stage oligomers and protofibrils of tau are believed to be strongly linked to human cognitive impairment while the toxic α-syn oligomers are associated with behavioral motor deficits. Therefore, concurrent targeting of both proteinaceous aggregates and oligomers are very challenging.
View Article and Find Full Text PDFChem Asian J
November 2024
Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Chiral luminescent liquid crystal (LC) materials with switchable circularly polarized luminescence (CPL) signals have received extensive attention, in which the use of light stimulation to achieve different CPL states is of great significance. However, there are very few reports on the generation and regulation of CPL signals enabled by blue phase LC (BPLC). Herein, achieving CPL signal inversion based on the phase transition induced by light/temperature stimulation in a BPLC system with a wide room-temperature window is reported.
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