Phosphonium Iodide Featuring Blue Thermally Activated Delayed Fluorescence for Highly Efficient X-Ray Scintillator.

Organic scintillators are praised for their abundant element reserves, facile preparation procedures, and rich structures. However, the weak X-ray attenuation ability and low exciton utilization efficiency result in unsatisfactory scintillation performance. Herein, a new family of highly efficient organic phosphonium halide salts with thermally activated delayed fluorescence (TADF) are designed by innovatively adopting quaternary phosphonium as the electron acceptor, while dimethylamine group and halide anions (I-) serve as the electron donor. The prepared butyl(2-[2-(dimethylamino)phenyl]phenyl)diphenylphosphonium iodide (C4-I) exhibits bright blue emission and an ultra-high photoluminescence quantum yield (PLQY) of 100 %. Efficient charge transfer is realized through the unique n-π and anion-π stacking in solid-state C4-I. Photophysical studies of C4-I suggest that the incorporation of I accounts for high intersystem crossing rate (kISC) and reverse intersystem crossing rate (kRISC), suppressing the intrinsic prompt fluorescence and enabling near-pure TADF emission at room temperature. Benefitting from the large Stokes shift, high PLQY, efficient exciton utilization, and remarkable X-ray attenuation ability endowed by I, C4-I delivers an outstanding light yield of 80721 photons/MeV and a low limit of detection (LoD) of 22.79 nGy ⋅ s-1. This work would provide a rational design concept and open up an appealing road for developing efficient organic scintillators with tunable emission, strong X-ray attenuation ability, and excellent scintillator performance.

Structure of a unique PSII-Pcb tetrameric megacomplex in a chlorophyll d-containing cyanobacterium.

Acaryochloris marina is a unique cyanobacterium using chlorophyll d (Chl d) as its major pigment and thus can use far-red light for photosynthesis. Photosystem II (PSII) of A. marina associates with a number of prochlorophyte Chl-binding (Pcb) proteins to act as the light-harvesting system. We report here the cryo-electron microscopic structure of a PSII-Pcb megacomplex from A. marina at a 3.6-angstrom overall resolution and a 3.3-angstrom local resolution. The megacomplex is organized as a tetramer consisting of two PSII core dimers flanked by sixteen symmetrically related Pcb proteins, with a total molecular weight of 1.9 megadaltons. The structure reveals the detailed organization of PSII core consisting of 15 known protein subunits and an unknown subunit, the assembly of 4 Pcb antennas within each PSII monomer, and possible pathways of energy transfer within the megacomplex, providing deep insights into energy transfer and dissipation mechanisms within the PSII-Pcb megacomplex involved in far-red light utilization.

Vebreltinib for Advanced Non-Small Cell Lung Cancer Harboring c-Met Exon 14 Skipping Mutation: A Multicenter, Single-Arm, Phase II KUNPENG Study.

PURPOSE: The KUNPENG study aimed to evaluate the efficacy and safety of vebreltinib (also known as bozitinib, APL-101, PLB-1001, and CBT-101), a potent and highly selective inhibitor of c-mesenchymal-epithelial transition (MET), in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) harboring c-Met alterations. METHODS: This multicenter, multicohort, open-label, single-arm, phase II trial enrolled patients with c-Met dysregulated, locally advanced or metastatic NSCLC from January 2020 to August 2022 across 17 centers. Cohort 1 included patients with MET exon 14 skipping (METex14)-mutant NSCLC who had not previously received MET inhibitors. Participants were administered vebreltinib at a dosage of 200 mg twice a day in 28-day cycles. The primary end point was the objective response rate (ORR), and the key secondary end point was the duration of response (DoR), both evaluated by a blinded independent review committee according to the RECIST version 1.1. RESULTS: As of August 9, 2022, 52 patients had been enrolled in cohort 1, of whom 35 (67.3%) were treatment-naïve. The ORR reached 75% (95% CI, 61.1 to 86). Among treatment-naïve patients, the ORR was 77.1% (95% CI, 59.9 to 89.6), and in previously treated patients, it was 70.6% (95% CI, 44.0 to 89.7). The disease control rate was 96.2%, with a median DoR of 15.9 months, a median progression-free survival of 14.1 months, and a median overall survival of 20.7 months. The most common treatment-related adverse events were peripheral edema (82.7%), QT prolongation (30.8%), and elevated serum creatinine (28.8%). CONCLUSION: Vebreltinib has shown promising efficacy and a favorable safety profile in patients with METex14-mutant NSCLC.