A donor-acceptor 10-cycloparaphenylene and its use as an emitter in an organic light-emitting diode

We thank JSPS Core-to-Core Program and International Joint Usage/Research Program of Institute for Chemical Research, Kyoto University (grant #2020-37 and 2021-37) for financial support. The St Andrews team would also like to thank EPSRC (EP/P010482/1) for financial support. D.C. thanks the China Scholarship Council (No. 201603780001). The Kyoto team would like to thank JSPS KAKENHI Grant Numbers JP20H05840 (Grant-in-Aid for Transformative Research Areas, “Dynamic Exciton”).Here, we explored the possibility of using cycloparaphenylenes (CPP) within a donor–acceptor TADF emitter design. 4PXZPh-[10]CPP contains four electron-donating moieties connected to a [10]CPP. In the 15 wt % doped in CzSi film, 4PXZPh-[10]CPP showed sky-blue emission with λPL = 475 nm, ΦPL = 29%, and triexponential emission decays with τPL of 4.4, 46.3, and 907.8 ns. Solution-processed OLEDs using 4PXZPh-[10]CPP exhibited sky-blue emission with an λEL of 465 nm and an EQEmax of 1.0%.Publisher PDFPeer reviewe

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

Authors thank EU Horizon 2020 Grant Agreement No. 812872 (TADFlife) for funding this project. Further support was obtained by the Helmholtz Association Program at the Karlsruhe Institute of Technology (KIT). The German Research Foundation (formally Deutsche Forschungsgemeinschaft DFG) in the framework of SFB1176 Cooperative Research Centre "Molecular Structuring of Soft Matter" (CRC1176, A4, B3, C2, C6) and the cluster 3D Matter Made To Order all funded under Germany’s Excellence Strategy 2082/1--390761711 are greatly acknowledged for financial contributions. We acknowledge support from the Engineering and Physical Sciences Research Council of the UK (grant EP/P010482/1), from the International Collaborative Research Program of Institute for Chemical Research, Kyoto University (grant # 2020-37 and 2021-37), and from JSPS KAKENHI Grant Number JP20H05840 (Grant-in-Aid for Transformative Research Areas, “Dynamic Exciton”). ZZ acknowledges the financial support from the China Scholarship Council (CSC, 201606890009) for his PhD studies. EZ-C is a Royal Society Leverhulme Trust Senior Research fellow (SRF\R1\201089).In this work we showcase the emitter DICzTRZ in which we employed a twin-emitter design of our previously reported material, ICzTRZ . This new system presented a redshifted emission at 488 nm compared to that of ICzTRZ at 475 nm and showed a comparable photoluminescence quantum yield of 57.1% in a 20 wt% CzSi film versus 63.3% for ICzTRZ . The emitter was then incorporated within a solution-processed organic light-emitting diode that showed a maximum external quantum efficiency of 8.4%, with Commission Internationale de l’Éclairage coordinate of (0.22, 0.47), at 1 mA cm−2.Publisher PDFPeer reviewe

Novel quantitative immunohistochemical analysis for evaluating PD-L1 expression with phosphor-integrated dots for predicting the efficacy of patients with cancer treated with immune checkpoint inhibitors

IntroductionProgrammed cell death ligand 1 (PD-L1) expression in tumor tissues is measured as a predictor of the therapeutic efficacy of immune checkpoint inhibitors (ICIs) in many cancer types. PD-L1 expression is evaluated by immunohistochemical staining using 3,3´-diaminobenzidine (DAB) chronogenesis (IHC-DAB); however, quantitative and reproducibility issues remain. We focused on a highly sensitive quantitative immunohistochemical method using phosphor-integrated dots (PIDs), which are fluorescent nanoparticles, and evaluated PD-L1 expression between the PID method and conventional DAB method.MethodsIn total, 155 patients with metastatic or recurrent cancer treated with ICIs were enrolled from four university hospitals. Tumor tissue specimens collected before treatment were subjected to immunohistochemical staining with both the PID and conventional DAB methods to evaluate PD-L1 protein expression.ResultsPD-L1 expression assessed using the PID and DAB methods was positively correlated. We quantified PD-L1 expression using the PID method and calculated PD-L1 PID scores. The PID score was significantly higher in the responder group than in the non-responder group. Survival analysis demonstrated that PD-L1 expression evaluated using the IHC-DAB method was not associated with progression-free survival (PFS) or overall survival (OS). Yet, PFS and OS were strikingly prolonged in the high PD-L1 PID score group.ConclusionQuantification of PD-L1 expression as a PID score was more effective in predicting the treatment efficacy and prognosis of patients with cancer treated with ICIs. The quantitative evaluation of PD-L1 expression using the PID method is a novel strategy for protein detection. It is highly significant that the PID method was able to identify a group of patients with a favorable prognosis who could not be identified by the conventional DAB method

Imidazole Acceptor for Both Vacuum-Processable and Solution-Processable Efficient Blue Thermally Activated Delayed Fluorescence

The members of the imidazole family have been widely used for electron transporting, host, conventional fluorescent, and phosphorescent materials. Although the imidazole core also has great potential as an acceptor segment of deep-blue thermally activated delayed fluorescence (TADF) owing to its high triplet energy, the emission color of imidazole-based TADF organic light-emitting diodes (OLEDs) has so far been limited to blue to green. In this work, four acridan-imidazole systems are theoretically designed aiming for deep- or pure-blue emitters. All four emitters exhibit deep-blue to blue emission owing to the high energy levels of the lowest excited singlet states, exhibiting y coordinates of Commission Internationale de l’Eclairage coordinates between 0.06 and 0.26. The molecule composed of a trifluoromethyl-substituted benzimidazole acceptor in combination with a tetramethyl-9, 10-dihydroacridine donor (named MAc-FBI) achieves a high maximum external quantum efficiency (EQEMAX) of 13.7% in its application to vacuum-processed OLEDs. The emitter has high solubility even in ecofriendly nonhalogenated solvents, which motivates us to fabricate solution-processed MAc-FBI-based OLEDs, resulting in an even higher EQEMAX of 16.1%

Regeneration of the periodontium for preservation of the damaged tooth

The population of the world grows every year, and life expectancy tends to increase. Thus, longterm preservation of teeth in aged individuals is an urgent issue. The main causes of tooth loss are well known to be periodontitis, caries, fractures, and orthodontic conditions. Although implant placement is a widely accepted treatment for tooth loss, most patients desire to preserve their own teeth. Many clinicians and researchers are therefore challenged to treat and preserve teeth that are irreversibly affected by deep caries, periodontitis, fractures, and trauma. Tissue engineering techniques are beneficial in addressing this issue; stem cells, signal molecules, and scaffolds are the main elements of such techniques. In this review, we describe these three elements with respect to their validation for regeneration of the periodontium and focus particularly on the potency of diverse scaffolds. In addition, we provide a short overview of the ongoing studies of 4- methacryloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl-borane resin including calcium chloride or hydroxyapatite for periodontium regeneration

Multichromophore Molecular Design for Efficient Thermally Activated Delayed Fluorescence Emitters with Near-Unity Photoluminescence Quantum Yields

Three multichromophore thermally activated delayed fluorescence (TADF) molecules, p-di2CzPN, m-di2CzPN, and 1,3,5-tri2CzPN, were synthesized and characterized. These molecules were designed by connecting the TADF moiety 4,5-di(9H-carbazol-9-yl)phthalonitrile (2CzPN) to different positions of a central benzene ring scaffold. Three highly soluble emitters all exhibited near quantitative photoluminescence quantum yields (PL) in toluene. High PLs were also achieved in doped films, 59% and 70% for p-di2CzPN and m-di2CzPN in 10 wt% DPEPO doped films, respectively, and 54% for 1,3,5-tri2CzPN in 20 wt% doped CBP film. The rate constant of reverse intersystem crossing (kRISC) for p-di2CzPN and m-di2CzPN in DPEPO films reached 1.1 × 105 s−1 and 0.7 × 105 s−1, respectively, and kRISC for 1,3,5-tri2CzPN in CBP film reached 1.7 × 105 s−1. A solution-processed organic light-emitting diode based on 1,3,5-tri2CzPN exhibited a sky-blue emission with CIE coordinate of (0.22, 0.44), and achieved a maximum external quantum efficiency of 7.1%

Multichromophore molecular design for efficient thermally activated delayed-fluorescence emitters with near-unity photoluminescence quantum yields

D.C thanks the China Scholarship Council (201603780001). P. R acknowledges support from a Marie Skłodowska-Curie Individual Fellowship (No. 749557). D. S. acknowledges support from the Marie Skłodowska-Curie Individual Fellowship (No. 838009). We acknowledge support from the Engineering and Physical Sciences Research Council of the United Kingdom (grant EP/P010482/1), from the International Collaborative Research Program of Institute for Chemical Research, Kyoto University (Nos. 2020-37 and 2021-37), and from JSPS KAKENHI Grant Number JP20H05840 (Grant-in-Aid for Transformative Research Areas, “Dynamic Exciton”).Three multichromophore thermally activated delayed fluorescence (TADF) molecules, p-di2CzPN, m-di2CzPN, and 1,3,5-tri2CzPN, were synthesized and characterized. These molecules were designed by connecting the TADF moiety 4,5-di(9H-carbazol-9- yl)phthalonitrile (2CzPN) to different positions of a central benzene ring scaffold. Three highly soluble emitters all exhibited near quantitative photoluminescence quantum yields (ΦPL) in toluene. High ΦPLs were also achieved in doped films, 59% and 70% for p-di2CzPN and m-di2CzPN in 10 wt% DPEPO doped films, respectively, and 54% for 1,3,5-tri2CzPN in 20 wt% doped CBP film. The rate constant of reverse intersystem crossing (kRISC) for p-di2CzPN and m-di2CzPN in DPEPO films reached 1.1×105 and 0.7×105 s−1, respectively, and kRISC for 1,3,5-tri2CzPN in CBP film reached 1.7×105 s−1. A solution-processed organic light-emitting diode based on 1,3,5-tri2CzPN exhibited a sky-blue emission with CIE coordinate of (0.22, 0.44), and achieved a maximum external quantum efficiency of 7.1%.PostprintPeer reviewe