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1. ²⁰ Ne(α,p) ²³ Na studied to constrain type Ia nucleosynthesis

   https://doi.org/10.1088/1742-6596/2586/1/012110  

   Boomershine, C N; Bardayan, D W; Carmichael, S; Caves, L; Davis, A; deBoer, R J; Gula, A; Howard, K; Kelmar, R; Mitchell, A; et al (September 2023, Journal of Physics: Conference Series)

   Abstract The²⁰Ne(α,p)²³Na reaction rate is important in determining the final abundances of various nuclei produced in type Ia supernovae. Previously, the ground state cross section was calculated from time reversal reaction experiments using detailed balance. The reaction rates extracted from these studies do not consider contributions from the population of excited states, and therefore, are only estimates. A resonance scan, populating both the ground and first excited states, was performed for the²⁰Ne(α,p)²³Na reaction, measuring between 2.9 and 5 MeV center of mass energies at the Nuclear Science Lab at the University of Notre Dame. Data analysis is underway and preliminary results show substantial contribution from the excited state reaction. 

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2. Enhanced mid-infrared emission of Pr ³⁺ ions in solids through a “3-for-1” excitation process – quantified

   https://doi.org/10.1364/OE.441516  

   Merkle, Larry_D; Fleischman, Zackery; Brown, Ei_Ei; Allen, Jan_L; Hommerich, Uwe; Dubinskii, Mark (November 2021, Optics Express)

   Evidence is presented that a “three-for-one” process based on two cross-relaxations between Pr³⁺ions efficiently populates the mid-infrared-emitting³H₅manifold in a Pr³⁺-doped low-maximum-phonon-energy host. The concentration dependence of infrared fluorescence spectra and lifetimes of polycrystalline Pr:KPb₂Cl₅initially excited to the³F_3,4manifolds indicate that the 3500-5500-nm fluorescence becomes strongly favored over shorter-wavelength infrared emission bands in the higher-concentration sample. The strong concentration dependence of the³F₃and³H₆manifold lifetimes suggests that both of these decay by cross-relaxation processes, resulting in more than one ion excited to³H₅for each ion initially excited to³F₃. Indeed, modeling and accounting for all possible decay paths indicate that, on average, about 2.3 ions are excited to³H₅for each initially-excited ion. This confirms that the three-for-one excitation process must occur and contribute significantly to the total excitation efficiency. These results indicate that the two distinct cross-relaxation processes observed between Pr ions result in substantially higher excitation quantum efficiency, 230%, than any ever reported in rare-earth doped materials. 

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3. Pressure pushes tRNA ^Lys3 into excited conformational states

   https://doi.org/10.1073/pnas.2215556120  

   Wang, Jinqiu; Koduru, Tejaswi; Harish, Balasubramanian; McCallum, Scott A.; Larsen, Kevin P.; Patel, Karishma S.; Peters, Edgar V.; Gillilan, Richard E.; Puglisi, Elisabetta V.; Puglisi, Joseph D.; et al (June 2023, Proceedings of the National Academy of Sciences)

   Conformational dynamics play essential roles in RNA function. However, detailed structural characterization of excited states of RNA remains challenging. Here, we apply high hydrostatic pressure (HP) to populate excited conformational states of tRNA Lys3 , and structurally characterize them using a combination of HP 2D-NMR, HP-SAXS (HP-small-angle X-ray scattering), and computational modeling. HP-NMR revealed that pressure disrupts the interactions of the imino protons of the uridine and guanosine U–A and G–C base pairs of tRNA Lys3 . HP-SAXS profiles showed a change in shape, but no change in overall extension of the transfer RNA (tRNA) at HP. Configurations extracted from computational ensemble modeling of HP-SAXS profiles were consistent with the NMR results, exhibiting significant disruptions to the acceptor stem, the anticodon stem, and the D-stem regions at HP. We propose that initiation of reverse transcription of HIV RNA could make use of one or more of these excited states. 

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4. Excitation-Wavelength-Dependent Photophysics of d ⁸ d ⁸ Di-isocyanide Complexes

   https://doi.org/10.1021/acs.inorgchem.1c02645  

   Pižl, Martin; Hunter, Bryan M.; Sazanovich, Igor V.; Towrie, Michael; Gray, Harry B.; Záliš, Stanislav; Vlček, Antonín (February 2022, Inorganic Chemistry)
5. Evidence for a lowest energy ³ MLCT excited state in [Fe(tpy)(CN) ₃ ] ⁻

   https://doi.org/10.1039/d1cc01090e  

   Vittardi, Sebastian B.; Magar, Rajani Thapa; Schrage, Briana R.; Ziegler, Christopher J.; Jakubikova, Elena; Rack, Jeffrey J. (May 2021, Chemical Communications)

   null (Ed.)

   Transient absorption data of [Fe II (tpy)(CN) 3 ] − reveals spectroscopic signatures indicative of 3 MLCT with a ∼10 ps kinetic component. These data are supported by DFT and TD-DFT calculations, which show that excited state ordering is responsive to the number of cyanide ligands on the complex. 

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