ABSTRACT Multiple‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters featuring rapid reverse intersystem crossing (RISC) are highly desirable for efficient triplet harvesting. Conventional heavy‐atom strategies often enhance RISC at the expense of spectral broadening, particularly when heavy atoms are embedded in 8π‐electron six‐membered rings, where aromaticity reversal between Hückel's and Baird's rules induces structural reorganization. Here, we report a design strategy through peripheral fusion of heavy‐atom‐containing five‐membered aromatic rings into a classical multiple‐resonance framework BCzBN. The rigid aromatic 6π‐electron rings maintain planarity in both ground and excited states for small reorganization energy, which effectively suppresses structural relaxation‐induced spectral broadening, while simultaneously enhancing spin–orbit coupling (SOC). The resulting emitters achieve narrowband pure‐green electroluminescence with a 27 nm full‐width at half‐maximum (FWHM) and Commission Internationale de l′Éclairage y ‐coordinate of 0.72, together with a RISC rate >10 6 s − 1 . Optimized organic light‐emitting diode devices show a maximum external quantum efficiency (EQE) of 31.3% with negligible efficiency roll‐off, maintaining EQEs of 31.2% and 25.6% at 1000 and 10 000 cd m − 2 , respectively. This work demonstrates the critical role of π‐electron counting in heavy‐atom integration and provides a general design principle for high‐performance MR‐TADF materials that concurrently achieve narrow emission and fast RISC kinetics.

Multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters featuring rapid reverse intersystem crossing (RISC) are highly desirable for efficient triplet harvesting. Conventional heavy-atom strategies often enhance RISC at the expense of spectral broadening, particularly when heavy atoms are embedded in 8π-electron six-membered rings, where aromaticity reversal between Hückel's and Baird's rules induces structural reorganization. Here, we report a design strategy through peripheral fusion of heavy-atom-containing five-membered aromatic rings into a classical multiple-resonance framework BCzBN. The rigid aromatic 6π-electron rings maintain planarity in both ground and excited states for small reorganization energy, which effectively suppresses structural relaxation-induced spectral broadening, while simultaneously enhancing spin-orbit coupling (SOC). The resulting emitters achieve narrowband pure-green electroluminescence with a 27nm full-width at half-maximum (FWHM) and Commission Internationale de l'Éclairage y-coordinate of 0.72, together with a RISC rate >106 s- 1. Optimized organic light-emitting diode devices show a maximum external quantum efficiency (EQE) of 31.3% with negligible efficiency roll-off, maintaining EQEs of 31.2% and 25.6% at 1000 and 10000cd m- 2, respectively. This work demonstrates the critical role of π-electron counting in heavy-atom integration and provides a general design principle for high-performance MR-TADF materials that concurrently achieve narrow emission and fast RISC kinetics.

Compositionally engineered metal-organic frameworks are designed and used to fabricate ultrafast scintillating films. The inclusion of hafnium ions in the nodes of the metal-organic framework enhances the interaction with ionizing radiation, partially compensating for the low density of the porous material and increasing the scintillation yield. The high diffusivity of molecular excitons within the framed conjugated ligands allows bimolecular annihilation processes that partially quench the system luminescence, resulting in fast scintillation pulses in the hundreds of picoseconds time scale. Despite the quenching, the gain in scintillation yield achieved is large enough to maintain the film light yield above 104 ph MeV-1 under soft X-rays. These high efficiencies and fast emission kinetics are obtained at room temperature in a technologically attractive solid-state configuration, placing the metal-organic framework platform in a prominent position for the realization of the next generation of fast scintillation counters for high-energy physics studies and medical imaging applications.

Formaldehyde releasers in cleaning products: Mapping an indoor issue.

Widespread environmental contamination by perfluoroalkyl and polyfluoroalkyl substances (PFAS) is raising particular concerns. PFAS are remarkably resistant to microbial degradation and have a profound impact on the structure and function of microbial communities. In this study, we analyzed the effect of perfluorooctanoic acid (PFOA) on bacterial quorum sensing, a communication process that in marine Vibrio species regulates biofilm formation and dissolution, virulence factors, swimming/swarming motility and bioluminescence. A system to continuously monitor bioluminescence during the growth on agar medium of Vibrio campbellii BB120 and isogenic luxS-, cpsA- and luxM-defective mutants, unable to synthesize, respectively, the autoinducers AI-2, CAI-1, and HAI-1, was utilized. By this system, we found that PFOA has dramatic effects on bacterial growth on agar and light emission kinetics, with specific effects in the different strains depending on the set of the autoinducers produced. Furthermore, we found that PFOA inhibited swarming motility in cqsA- and luxM-defective mutants which exhibited a very robust swarming phenotype in the absence of PFOA due to the lack of CAI-1 or HAI-1 that inhibit motility. The inhibitory effect on motility could be due to increased adherence of bacterial colonies to the agar substrate caused by the presence of PFOA. These results, although obtained in an in vitro system, suggest that PFOA may strongly interfere with bacterial growth kinetics and quorum sensing-regulated responses.

Emission Kinetics of Yb3+ Upper Laser Level in Optical Ceramics of Different Thicknesses Based on Y2O3

Contribution of rubber modified asphalt to emission and odors tracing: Experimental and modelling investigation.

An isomeric emitter (2TPA-iCNBT) is designedand synthesized,displaying enhanced thermally activated delayed fluorescence (TADF)properties as compared to the reference near-infrared (NIR) emitterTPACNBz (hereafter referred to as 2TPA-CNBT). Its modifiedbenzo­[c]­[1,2,5]­thiadiazole-4,7-dicarbonitrile (iCNBT) acceptor (A) core positions the two triphenylamine(TPA) donor (D) units adjacently, thereby increasing the D–Atorsion angle. Synthesis is realized through the use of an unexploiteddirect arylation strategy, which, besides offering the desired materialsin an efficient and straightforward way, can also yield monofunctionalizedemitters (1TPA-CNBT and 1TPA-iCNBT). Intotal, four emitters are synthesized, characterized, and subsequentlycompared in terms of their spectroscopic and device properties. Densityfunctional theory is applied to simulate their relative moleculargeometry and the arrangement of their (emissive) excited states. Steady-stateand time-resolved emission spectroscopy reveal strongly contrastingTADF properties, with 2TPA-iCNBT exhibiting the largestincrease in the photoluminescence quantum yield on removal of oxygen(from 27 to 55%), and the fastest TADF emission kinetics in dopedfilms (kRISC ∼ 105 s–1). In solution-processed organic light-emitting diodes,decent maximum external quantum efficiency (EQE) values are obtainedfor 2TPA-iCNBT (2.49%), 1TPA-CNBT (2.91%),and 1TPA-iCNBT (2.76%), in clear contrast to 2TPA-CNBT (1.16%), highlighting the decisive role of the D–A substitutionpattern (and the number of D groups) on the performance of NIR-TADFemitters. Furthermore, 2TPA-iCNBT is shown to maintainthe highest EQE at larger current densities (EQE = 1.98% at 10 mAcm–2) within the investigated series, a consequenceof its standout TADF behavior.

Coal blending in thermal power plants is a complex multi-objective challenge involving economic, operational and environmental considerations. This study presents a Q-learning-enhanced NSGA-II (QLNSGA-II) algorithm that integrates the adaptive policy optimization of Q-learning with the elitist selection of NSGA-II to dynamically adjust crossover and mutation rates based on real-time performance metrics. A physics-based objective function takes into account the thermodynamics of ash fusion and the kinetics of pollutant emission, ensuring compliance with combustion efficiency and NOx limits. Benchmark tests on the Walking Fish Group (WFG) and Unconstrained Function (UF) suites show that QLNSGA-II achieves a 12.7% improvement in Inverted Generational Distance (IGD) and a 9.3% improvement in Hypervolume (HV) compared to prevailing algorithms. Industrial validation at the Huaneng Yingkou power plant confirms a 14.7% reduction in fuel cost and a 41% reduction in slagging incidence over conventional blending methods, backed by 12 months of operational data. Other benefits include a 24.8% reduction in sulphur content, a 6.9% increase in the plant’s net heat rate and annual savings of RMB 12.3 million, 2,150 tonnes of limestone and 38,500 tonnes of CO2-equivalent emissions. These results highlight QLNSGA-II as a scalable, robust solution for multi-objective coal blending, offering a promising way to improve the efficiency and sustainability of coal-fired power generation.

Abstract White organic light‐emitting diodes (WOLEDs) are promising candidates for next‐generation lighting and display technologies. However, conventional WOLED fabrication often relies on complex doping schemes or multiple color stacked emitting layers, complicating device design, and fabrication. Here, a simple approach for fabricating ITO‐free WOLEDs with a single‐component, using a planar aluminium microcavity, is presented. By engineering the cavity and surface plasmon polariton modes around the emission resonance of the high‐efficiency blue thermally activated delayed fluorescence emitter DMAC‐DPS, electroluminescence that is spectrally broadened to white light, with a tunable color temperature ranging from 3790 to 5050 K, is achieved. The WOLEDs are top‐emitting and reach an external quantum efficiency of >5%. The results are supported by optical simulations and transient emission measurements, providing insights into the emission kinetics.

We present an analytical model for Förster resonance energy transfer (FRET) between a donor and an acceptor placed in an inhomogeneous and absorptive environment characterized by a complex dielectric function, e.g., near a metal-dielectric structure. By extending the standard approach to FRET to include energy transfer (ET) channel to the environment, we show that, in the absence of plasmonic enhancement effects, the Förster radius, which defines the characteristic distance for efficient FRET, is reduced due to a competing ET process. We demonstrate that the reduction in the Förster radius can dramatically affect fluorescence from large ensemble of molecules whose emission kinetics is dominated by FRET-induced concentration quenching. In particular, we perform numerical calculations for dye-doped polymer films deposited on top of a metallic substrate to find that, at high dye concentrations, the emission kinetics slows down considerably as compared to the same films on a glass substrate, in sharp contrast to acceleration of single-molecule fluorescence near the metal. Furthermore, the effective fluorescence decay rate exhibits a non-monotonic behavior with varying film thickness, consistent with the experiment, indicating a non-trivial interplay between the metal quenching and concentration quenching mechanisms.

Highly scattering media have garnered significant interest in recent years, ranging from potential applications in solar cells, photocatalysis, and other novel photonic devices to research on fundamental topics such as topological photonics, enhanced light-matter coupling and light confinement. Here, we report measurements of spectrally and time-resolved delayed luminescence (DL) in highly scattering rutile TiO2 films. The complex emission kinetics manifests in the non-exponential decay of photon density and the temporal evolution of the spectral composition. We found that while the energy levels of TiO2 nanoparticles broadly set the spectral regions of excitation and emission, our results demonstrate that the DL intensity and duration are strongly influenced by the inherent multiple elastic and inelastic processes determined by the mesoscale inhomogeneous structure of random media. We show that the lifetime of DL increases up to 6 s for the largest redshift detected, which is associated with multiple reabsorption processes. We outline a simple model for spectrally resolved DL emission from dense scattering media that can guide the design and characterization of composite materials with specific spectral and temporal properties.

In this paper, the visible thermal emission of carbon materials under the irradiation by nanosecond infrared laser pulses is investigated. For rough carbon surfaces, the experiments show that the pulse length of laser-induced thermal emission depends on the direction of observation. In particular, in the case of observation along the material’s surface, the duration of the emission pulse is typically 20÷40% longer than in the direction perpendicular to the surface. For the explanation of the observed anisotropy of the kinetics of laser-induced thermal emission, a calculation model is proposed, which accounts for significant heterogeneity of pulsed laser heating of rough surfaces. The computer modeling predicts that peaks and valleys of the surface relief can be heated to significantly different local temperatures, and the temperature relaxation in the relatively hot peaks is longer than in the relatively cold valleys. As a result, when the laser-induced thermal emission is observed along the surface, the valleys are shadowed by the peaks, and this circumstance leads to the observed anisotropy of thermal emission kinetics. The results of the computer simulations with regard for the effect of shadowing are consistent with the results of measurements.

Precise control of lanthanide luminescence decay is essential for the development of emerging nanophotonic applications. However, existing strategies rely on static material modifications. Here, we introduce a pumping-flux modulation strategy that enables reversible, on-demand tuning of luminescence lifetimes via direct control of the cross-relaxation processes. Using highly Er3+-doped nanocrystals, we demonstrate that adjusting excitation pulse duration and intensity enables over 10-fold tuning in green (from 47.3 to 537.1 μs) and near-infrared (1506.4 to 145.5 μs) emissions. Mechanistic studies reveal that excitation profile modulation alters the populations of ground and intermediate energy states, which, in turn, influences cross-relaxation pathways and emission kinetics. We further demonstrate dynamically programmable lifetime mapping for optical encryption, eliminating the need for complex materials engineering. This work introduces a fundamentally new route for controlling lanthanide emission in real time with broad implications for adaptive displays, reconfigurable photonics, and time-domain optical security.

Setups have been developed and constructed to study the main scintillation properties, such as light yield and emission kinetics, of liquid organic scintillators used in neutrino physics and astroparticle physics experiments. The measurement results of the main characteristics of these setups are presented in this work.

Proton conducting oxide such as BaCe0.4Zr0.4Y0.2O3-δ(BCZY) electrolyte is known for its unique stability and high ionic conductivity due to the doping effect from the substitution of Zr and Y for Ce ions. For reaching the 2050 net-zero carbon goal, ammonia has been recognized as an important H2 carrier for ease transportation. Thus, using the proton conductor as an electrolyte for ammonia applications including conversion and synthesis provides extra advantages such as lower operation temperatures, negligible NOx emission and better kinetics. Thus, solid oxide cells based on a BCZY proton conducting electrolyte received great attention not only for green hydrogen but also ammonia fuel.However, the densification of BCZY needs heating temperatures as high as 1400°C. Although the adoption of sintering additives such ZnO or NiO in BCZY has shown some improvement, the densification mechanism remains ambiguous. Thus, the objective of this study is to understand the role and mechanism of adding sintering additive in BCZY. The influence of composite electrode processed at lower temperature on its performance will be also discussed due to the better-densified BCZY. In additions, the resulted electrical and structural properties will be analyzed and discussed based on reactions and densification through heating process. The crystal structure and microstructure of densified BCZY was also characterized using XRD, field-emission SEM, and STEM.

Abstract Background: Esophageal adenocarcinoma (EAC) has a low 5-year survival rate and limited options for targeted therapies. Circulating tumor (ct)DNA isolated from liquid biopsies could help monitor patients to personalize treatment decisions. However, ctDNA studies in EAC remain sparse, and significant knowledge gaps exist in our understanding of ctDNA emission in response to therapy. The goal of this study was 1) to conduct a multimodal, longitudinal analysis of plasma cell free (cf)DNA in EAC patients and 2) to better understand the biology of ctDNA release during drug treatment. Methods: 1) A total of 189 longitudinal blood samples were collected from 41 EAC patients throughout treatment. cfDNA was isolated from baseline and post-neoadjuvant chemo samples for targeted deep sequencing alongside white blood cell controls. Shallow whole-genome sequencing was conducted on cfDNA for ichorCNA and fragmentomics analysis. 2) To dynamically monitor ctDNA fluctuations during EAC treatment, cfDNA was isolated from all other timepoints for digital (d)PCR quantification of the mutations identified from sequencing. ctDNA release kinetics were studied in vitro using three cell lines (OE19, FLO-1, A549), as well as our newly established cisplatin resistant model of OE19. ctDNA was analyzed by Qubit, dPCR, and Bioanalyzer. Annexin-V/PI flow cytometry was used to assess percentages of apoptotic and necrotic cells to correlate ctDNA to release mechanism. Results: 1) Sequencing has been completed for 21/41 patients and is ongoing for 20/41 patients. In the first 21 patients, somatic mutations were found in potential EAC driver genes, such as KRAS, TP53, ACVR2A, NOTCH1, and APC. Interestingly, in one patient’s cfDNA sample sequenced post neoadjuvant chemo, a novel mutation emerged in FBXW7, representing a potential resistance driver. ichorCNA tumor fraction (TF) values overall were low, and when using the recommended 0.03 TF estimate cutoff, there were significantly larger baseline TF values in metastatic (stage IVB) patients than those with localized disease (stage III) (p<0.05). 2) In vitro viable cancer cell numbers correlated to ctDNA levels, as measured by qubit and dPCR analysis. Additionally, cisplatin and 5-FU chemo treatments led to larger ctDNA release in all cells. ctDNA emission kinetics correlated to cytotoxicity (apoptosis and necrosis as shown through flow cytometry), with higher levels of ctDNA released by cisplatin-sensitive vs. resistant cells (p<0.05). Additionally, cisplatin treatment caused a shift in average ctDNA fragment size, with larger fragments observed during treatment, corresponding to an increased proportion of necrotic cells. Conclusions: This study reveals that multimodal cfDNA analysis can successfully be used in EAC patients to monitor treatment response and potentially identify resistance mechanisms. Moreover, in vitro models demonstrated a correlation of ctDNA emission and fragment length with chemo-cytotoxicity, shedding light on the release kinetics of DNA from cancer cells. Citation Format: Alexandra Bartolomucci, Laura Kienzle, Sarah Tadhg Ferrier, Lisa-Monique Edward, Jeffrey Bruce, Kwang-Bo Joung, Stephenie Prokopec, Wotan Zeng, Abirami Sharma, Kyle Dickinson, Nicholas Bertos, Jonathan Cools-Lartigue, Lorenzo Ferri, Trevor J. Pugh, Julia V. Burnier. ctDNA release kinetics and fragmentation to monitor treatment response and resistance in esophageal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr PR003.

Greenhouse gas emission and denitrification kinetics of woodchip bioreactors treating onsite wastewater

Triplet fusion (TF) has recently attracted attention because of its great potential of various applications. Since high reaction efficiency of TF is demanded in any applications, it is necessary to clarify the mechanism of triplet exciton dynamics that is an important elementary process to enhance the TF efficiency. Therefore, in this paper, we study the triplet exciton dynamics of 9,10-diphenylanthracene (DPA), which shows the TF-based fluorescence, in a solvent of tetraethylene glycol dimethyl ether and in polycrystal of DPA, in combination with the triplet sensitization using platinum octaethylporphyrin. The observed emission kinetics and their magnetoluminescence effect indicate that the rotational and the multitrapping diffusions of the triplet exciton play an inherent role respectively in the fluid solution and in the polycrystalline solid.

Acridinium esters, due to their capability for chemiluminescence (CL), are employed as indicators and labels in biomedical diagnostics and other fields. In this work, the influence of ionic surfactants, hexadecyltrimethylammonium chloride and bromide (CTAC and CTAB, cationic) and sodium dodecyl sulphate (SDS, anionic) on the CL parameters and mechanism of representative emitter, 10-methyl-9-[(2-methylphenoxy)carbonyl]acridinium trifluoromethanesulphonate (2MeX) in a H2O2/NaOH environment, is studied. Our investigations revealed that the type of surfactant and its form in solution have an impact on the CL kinetic constants and integral efficiencies, while changes in those emission properties resulting from the type of ion (Cl- vs. Br-) are negligible. The major changes were recorded for systems containing surfactants at concentrations higher than the critical micelle concentration. The cationic surfactants (CTAC, CTAB) cause a substantial increase in CL emission kinetics and a moderate increase in its integral efficiency. At the same time, the opposite effect is observed in the case of SDS. Molecular dynamics simulations suggest that changes in emission parameters are likely due to differences in the binding strength of 2MeX substrate with surfactant molecules, which is higher for SDS than for CTAC. The results can help in rational designing of optimal acridinium CL systems and demonstrate their usefulness in distinguishing the pre- and post-micellar environment and the charge of surfactants.