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1. Spectroscopic study of the 4f ⁷ 6s ^{2 8} S 7/2∘ – 4f ⁷ ( ⁸ S ^° ) 6s6p( ¹ P ^° ) ⁸ P _5/2,7/2 transitions in neutral europium-151 and europium-153: absolute frequency and hyperfine structure

   https://doi.org/10.1364/JOSAB.521181  

   Maruko, C.; Çölmek, N_N; Herd, M_T; Ahrendsen, K_J; Cabrales, B.; Cannon, G.; Davis, E.; Guo, X_Y; Karani, T.; Wallace, A.; et al (April 2024, Journal of the Optical Society of America B)

   We report on spectroscopic measurements on the 4f⁷6s²⁸S_7/2^∘−4f⁷(⁸S^∘)6s6p(¹P^∘)⁸P_5/2,7/2transitions at 466.32 nm and 462.85 nm, respectively, in neutral europium-151 and europium-153. The center of gravity frequencies for the 151 and 153 isotopes for both transitions are reported for the first time using saturated absorption spectroscopy. For the 6s6p(¹P^∘)⁸P_5/2state, the center of gravity frequencies were found to be 642,894,493.3(4) MHz and 642,891,693.3(9) MHz for the 151 and 153 isotopes, respectively. The hyperfine constants for the upper state were found to beA(151)=−157.01(3)MHz,B(151)=74.5(4)MHz andA(153)=−69.43(14)MHz,B(153)=191.0(26)MHz. These hyperfine values are all consistent with previously published results except forB(151) that has a small discrepancy. The isotope shift was found to be 2799.54(20) MHz, a small discrepancy with previously published results. For the 6s6p(¹P^∘)⁸P_7/2state, the center of gravity frequencies were found to be 647,708,930.6(6) MHz and 647,705,958.4(26) MHz for the 151 and 153 isotopes, respectively. The hyperfine constants for the upper state were found to beA(151)=−218.66(4)MHz,B(151)=−293.4(8)MHz andA(153)=−97.15(13)MHz,B(153)=−750(3)MHz. These values are all consistent with previously published results except forA(151) that has a small discrepancy. The isotope shift was found to be 2972.8(5) MHz, a small discrepancy with previously measured results. 

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2. Investigation of Pb–B Bonding in PbB ₂ (BO) _n ⁻ ( n = 0–2): Transformation from Aromatic PbB ₂ ⁻ to Pb[B ₂ (BO) ₂ ] ^−/0 Complexes with BB Triple Bonds

   https://doi.org/10.1039/D3CP02800C  

   Chen, Qiang; Chen, Wei-Jia; Wu, Xin-Yao; Chen, Teng-Teng; Yuan, Rui-Nan; Lu, Hai-Gang; Yuan, Dao-Fu; Li, Si-Dian; Wang, Lai-Sheng (February 2024, Physical Chemistry Chemical Physics)

   Joint photoelectron spectroscopy and first-principles theory investigations indicate that the Pb-doped PbB₂(BO)_n⁻clusters (n= 0−2) undergo a transformation from σ + π doubly aromatic triangle PbB₂⁻to PbB₄(BO)₂^−/0complexes with a B≡B triple bond. 

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3. Facile Conversion of syn ‐[Fe ^IV (O)(TMC)] ²⁺ into the anti Isomer via Meunier's Oxo–Hydroxo Tautomerism Mechanism

   https://doi.org/10.1002/anie.201811454  

   Prakash, Jai; Sheng, Yuan; Draksharapu, Apparao; Klein, Johannes E. M. N.; Cramer, Christopher J.; Que, Jr., Lawrence (January 2019, Angewandte Chemie International Edition)

   Abstract Thesynandantiisomers of [Fe^IV(O)(TMC)]²⁺(TMC=tetramethylcyclam) represent the first isolated pair of synthetic non‐heme oxoiron(IV) complexes with identical ligand topology, differing only in the position of the oxo unit bound to the iron center. Both isomers have previously been characterized. Reported here is that thesynisomer [Fe^IV(O_syn)(TMC)(NCMe)]²⁺(2) converts into itsantiform [Fe^IV(O_anti)(TMC)(NCMe)]²⁺(1) in MeCN, an isomerization facilitated by water and monitored most readily by¹H NMR and Raman spectroscopy. Indeed, when H₂¹⁸O is introduced to2, the nascent1becomes¹⁸O‐labeled. These results provide compelling evidence for a mechanism involving direct binding of a water moleculetransto the oxo atom in2with subsequent oxo–hydroxo tautomerism for its incorporation as the oxo atom of1. The nonplanar nature of the TMC supporting ligand makes this isomerization an irreversible transformation, unlike for their planar heme counterparts. 

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4. K–Co–Mo–S _x chalcogel: high-capacity removal of Pb ²⁺ and Ag ⁺ and the underlying mechanisms

   https://doi.org/10.1039/D4TA05158K  

   Nie, Jing; Chandra_Roy, Subrata; Dhami, Sital; Islam, Taohedul; Amin, Ruhul; Zhu, Xianchun; Taylor-Pashow, Kathryn; Han, Fengxiang X; Islam, Saiful M (November 2024, Journal of Materials Chemistry A)

   Disordered aggregated porous nanoparticles of KCMS are highly efficient and have exceptionally high sorption capacity in removing Ag⁺and Pb²⁺following the exchange of K⁺and Co²⁺ions bonded electrostatically and covalently in KCMS, respectively. 

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5. The vacuolar Ca ²⁺ transporter CATION EXCHANGER 2 regulates cytosolic calcium homeostasis, hypoxic signaling, and response to flooding in Arabidopsis thaliana

   https://doi.org/10.1111/nph.19274  

   Bakshi, Arkadipta; Choi, Won‐Gyu; Kim, Su‐Hwa; Gilroy, Simon (September 2023, New Phytologist)

   Summary Flooding represents a major threat to global agricultural productivity and food security, but plants are capable of deploying a suite of adaptive responses that can lead to short‐ or longer‐term survival to this stress. One cellular pathway thought to help coordinate these responses is via flooding‐triggered Ca²⁺signaling.We have mined publicly available transcriptomic data from Arabidopsis subjected to flooding or low oxygen stress to identify rapidly upregulated, Ca²⁺‐related transcripts. We then focused on transporters likely to modulate Ca²⁺signals. Candidates emerging from this analysis includedAUTOINHIBITED Ca²⁺ATPASE 1andCATION EXCHANGER 2. We therefore assayed mutants in these genes for flooding sensitivity at levels from growth to patterns of gene expression and the kinetics of flooding‐related Ca²⁺changes.Knockout mutants inCAX2especially showed enhanced survival to soil waterlogging coupled with suppressed induction of many marker genes for hypoxic response and constitutive activation of others.CAX2mutants also generated larger and more sustained Ca²⁺signals in response to both flooding and hypoxic challenges.CAX2 is a Ca²⁺transporter located on the tonoplast, and so these results are consistent with an important role for vacuolar Ca²⁺transport in the signaling systems that trigger flooding response. 

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