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To achieve high efficiency and reliability in thermally activated delayed fluorescence (TADF) and phosphorescent organic light-emitting diodes (OLEDs), developing a novel host system has emerged as a critical research theme. In this study, we synthesized CzCzPh-mAd (9-(3-((1s,3s)-adamantan-1-yl)phenyl)-9H-3,9′-bicarbazole) as a p-type host by incorporating a bulky adamantane moiety fused with three cyclohexanes into CzCzPh (9-phenyl-9H-3,9′-bicarbazole). By incorporating a large and rigid adamantane group into the CzCzPh host (CzCzPh-mAd), we aimed to maintain the electrochemical and photophysical properties of CzCzPh while increasing its molecular weight, film-forming characteristics, and thermal stability. Ultimately, the solution-processed narrowband blue TADF-OLED employing the CzCzPh-mAd host exhibited a high external quantum efficiency greater than 13% and demonstrated superior thermal stability and reproducibility in device efficiency compared to devices based on CzCzPh. [ABSTRACT FROM AUTHOR]

Introduction Prostate cancer (PC) is the third leading cause of cancer-related death among men in the United States, where 1 in 8 men are expected to be diagnosed with PC [...], Prostate cancer (PC) progressed to castration resistance (CRPC) is a fatal disease. CRPC tumors develop resistance to new-generation antiandrogen enzalutamide through lineage plasticity, characterized by epithelial-mesenchymal transition (EMT) and a basal-like phenotype. FOXA1 is a transcription factor essential for epithelial lineage differentiation. Here, we demonstrate that FOXA1 loss leads to remarkable upregulation of transforming growth factor beta 3 (TGFB3), which encodes a ligand of the TGF-[beta] pathway. Mechanistically, this is due to genomic occupancy of FOXA1 on an upstream enhancer of the TGFB3 gene to directly inhibit its transcription. Functionally, FOXA1 downregulation induces TGF-[beta] signaling, EMT, and cell motility, which is effectively blocked by the TGF-[beta] receptor I inhibitor galunisertib (LY2157299). Tissue microarray analysis confirmed reduced levels of FOXA1 protein and a concordant increase in TGF-[beta] signaling, indicated by SMAD2 phosphorylation, in CRPC as compared with primary tumors. Importantly, combinatorial LY2157299 treatment sensitized PC cells to enzalutamide, leading to synergistic effects in inhibiting cell invasion in vitro and xenograft CRPC tumor growth and metastasis in vivo. Therefore, our study establishes FOXA1 as an important regulator of lineage plasticity mediated in part by TGF-[beta] signaling, and supports a novel therapeutic strategy to control lineage switching and potentially extend clinical response to antiandrogen therapies.

All‐polymer photovoltaics (all‐PPVs) that operate under both indoor and outdoor lighting conditions require active layers with appropriately adjusted optical‐absorption ranges. However, the optical absorption of a conventional donor–acceptor binary blend is restricted to the combined absorption bands of its components. Herein, a new conjugated block copolymer (CBC) acceptor, b‐PYT, is designed by integrating polymer acceptor blocks of wide and narrow bandgaps in a single structure. Such combination results in the wide absorption range (550–850 nm) of b‐PYT that matches the emission of both artificial and solar light. The b‐PYT CBC acceptor is more crystalline than the corresponding random terpolymer, r‐PYT, owing to improved interactions between its macromolecular acceptor units. Despite exhibiting slightly inferior outdoor performance compared to that of devices using the homopolymer BTTP‐T, the PM6:b‐PYT‐based devices deliver superior power conversion efficiency (PCE) under indoor light‐emitting diode (LED) light owing to better matched absorption and emission spectra of b‐PYT and a cold white LED, respectively. Additionally, it is worth highlighting that PM6:b‐PYT‐based all‐PPVs can maintain approximately 87% of the initial PCE even after 600 min of thermal aging at 150 °C, which demonstrates the superior thermal stability compared with those of all‐PPVs that use traditional binary active layers. [ABSTRACT FROM AUTHOR]

Multiple‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters exhibit enormous potential for use in organic light‐emitting diodes (OLEDs), owing to their exceptional external quantum efficiencies (EQEs) and narrowband emission spectra. However, planar MR‐TADF emitters often suffer from aggregation‐caused quenching (ACQ) and spectral broadening at high doping concentrations because of strong interchromophore π–π interactions. A method of sterically encapsulating the planar MR skeleton with four bulky 9‐phenyl‐fluorene (Fl) units is devised, resulting in the development of a bright bluish‐green emitter (4FlCzBN). This steric shielding effectively reduces intermolecular interactions, suppresses ACQ, and improves solubility. Consequently, by utilizing 4FlCzBN as a doping‐insensitive MR emitter, solution‐processed OLEDs are fabricated with doping concentrations of 2–16 wt.%, and they show EQEs of 10.1–10.9% with a bandwidth of 28–30 nm. Furthermore, a TADF‐sensitizer‐based device using 4FlCzBN demonstrates a significantly reduced efficiency roll‐off while achieving an EQE of 12.2%. This is a remarkable improvement that overcomes the disadvantages that are difficult to achieve in previously reported MR‐TADF OLEDs. The current work provides valuable insights into the design of efficient MR‐TADF emitters with minimized aggregation and reduced efficiency roll‐off for solution processing. [ABSTRACT FROM AUTHOR]