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1. 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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2. N ⁵ -Scaling Excited-State-Specific Perturbation Theory

   https://doi.org/10.1021/acs.jctc.0c00308  

   Clune, Rachel; Shea, Jacqueline A.; Neuscamman, Eric (October 2020, Journal of Chemical Theory and Computation)

   null (Ed.)
3. Search for two-neutrino double-beta decay of ¹³⁶ Xe to the excited state of ¹³⁶ Ba with the complete EXO-200 dataset*

   https://doi.org/10.1088/1674-1137/aceee3  

   Al_Kharusi, S; Anton, G; Badhrees, I; Barbeau, PS; Beck, D; Belov, V; Bhatta, T; Breidenbach, M; Brunner, T; Cao, GF; et al (October 2023, Chinese Physics C)

   Abstract A new search for two-neutrino double-beta (2νββ) decay of¹³⁶Xe to theexcited state of¹³⁶Ba is performed with the full EXO-200 dataset. A deep learning-based convolutional neural network is used to discriminate signal from background events. Signal detection efficiency is increased relative to previous searches by EXO-200 by more than a factor of two. With the addition of the Phase II dataset taken with an upgraded detector, the median 90% confidence level half-life sensitivity of 2νββdecay to thestate of¹³⁶Ba isyr using a total¹³⁶Xe exposure of 234.1 kg yr. No statistically significant evidence for 2νββdecay to thestate is observed, leading to a lower limit ofyr at 90% confidence level, improved by 70% relative to the current world's best constraint. 

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4. The ligand-to-metal charge transfer excited state of [Re(dmpe)3]2+

   https://doi.org/10.1007/s11120-021-00859-7  

   Rodriguez, Tayliz M.; Deegbey, Mawuli; Jakubikova, Elena; Dempsey, Jillian L. (July 2021, Photosynthesis Research)

   null (Ed.)

   The ligand-to-metal charge transfer (LMCT) transitions of [Re(dmpe)3]2+ (dmpe = bis-1,2-(dimethylphosphino)ethane) were interrogated using UV/Vis absorbance spectroscopy, photoluminescence spectroscopy, and time-dependent density functional theory. The solvent dependence of the lowest energy charge transfer transition was quantified; no solvatochromism was observed. TD-DFT calculations reveal the dominant LMCT transition is highly symmetric and delocalized involving all phopshine ligand donors in the charge transfer, providing an understanding for the absence of solvatochromism of [Re(dmpe)3]2+. 

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5. Atomic autoionization in the photo-dissociation of super-excited deuterated water molecules fragmenting into D ⁺ + O ⁺ + D

   https://doi.org/10.1039/D3CP02438E  

   Iskandar, W; Rescigno, T N; Orel, A E; Larsen, K A; Griffin, B; Call, D; Davis, V; Jochim, B; Severt, T; Williams, J B; et al (August 2023, Physical Chemistry Chemical Physics)

   Creation of a super-excited radical water cation results in a long-lived excited oxygen fragment that can act as a destructive carrier and initiate secondary reactions such as breakup of DNA strands – a key radiation damage mechanism. 

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