Search

A deep-blue exciplex with thermally activated delayed fluorescence (TADF) at 444 nm enabled organic light-emitting diodes (OLEDs) with CIE coordinates of (0.152, 0.075) and EQE up to 4.83%, meanwhile, which can also serve as a co-host for wide color phosphorescent OLEDs.

Quasi-2D perovskites are natural quantum well (QW) structures composed of insulating organic layers inserted between conducting [A

Organic phosphorescence materials provide an opportunity to use triplets for lasing. However, population inversion based on phosphorescence is hard to establish, owing to low luminescent quantum efficiency and intensive optical loss. By comparison, thermally activated delayed fluorescence emitters exhibit excellent optical gain with the aid of the reverse intersystem crossing (RISC) process. In this work, we designed a multifunctional gain material, not only serving as a thermally activated delayed fluorescence (TADF) emitter with excellent optical gain but also working as a phosphorescence source with high utilization of triplets. The lone pair of electrons in oxygen substitutions promotes a fast spin-flip and high delayed fluorescence quantum yield (Φ

Chainlike ZSM-5 was synthesized in a tetrapropylammonium hydroxide (TPAOH) and poly(diallydimethylammonium chloride) (PDDA) dual-template system. The synthesis parameters and formation mechanism of chainlike zeolites were investigated. The optimized composition of the synthesis mixture was as follows: the PDDA/SiO

Understanding the structure-property relationships in organic semiconductors is crucial for controlling their photophysical properties and developing new optoelectronic materials. Quadrupolar molecules, donor-acceptor-donor (DAD), have attracted extensive attention in various optoelectronic applications. However, the systematic studies on the differences on photophysical properties between DAD and simple donor-acceptor (DA) chromophores are rarely reported. Herein we present a comparative study on the excited state dynamics of DA and DAD fluorescence systems using theoretical calculation and transient absorption spectroscopy. Results show that DA and DAD molecules exhibit similar excited state dynamics, which are attributed to the distinctive excited-state symmetry breaking (ESSB) phenomenon observed in a DAD system. The strong photoluminescence (PL) and ultrafast charge separation (CS) from an ESSB-induced partial charge transfer (CT) state were clearly detected in different solvent environments. These results not only offer insight into the excited state dynamics of the DAD fluorescence system but also provide some basic guidelines for designing new optoelectronic materials.

Singlet fission (SF) has attracted much attention on account of its great potential for applications in high efficiency solar energy conversion. The major roadblock to realize this potential is roo...

The incidence of adenocarcinoma of esophageal-gastric junction (AEJ) has been increasing in recent years. Esophagogastrostomy after proximal gastrectomy (PG-EG) is the most commonly used surgical method for this disease which causes a constant spasm of the pyloric sphincter by cutting the vagus nerve around the esophagus, so H-M pyloroplasty (Heineke-Mikulicz pyloroplasty) is often operated after PG-EG to prevent delayed gastric emptying. However, H-M pyloroplasty destroys anti-reflux structure of pylorus and leads to serious bile reflux. The present study was designed to compare pyloromyotomy and H-M pyloroplasty in proximal subtotal gastrectomy through clinical studies and animal experiments.We retrospectively evaluated the outcomes of 73 AEJ patients (39 underwent PG-EG with an H-M pyloroplasty and 34 underwent PG-EG with a pyloromyotomy) between January 2016 and August 2020, and perioperative variables were compared. In the animal experiment, 48 rats were randomly divided into four groups (n = 12): vagotomy group (V group), H-M pyloroplasty group (HM group), pyloromyotomy group (PM group), and control group (O group). Gastric emptying and bile reflux were evaluated in each group.In the retrospective clinic study, pyloromyotomy and H-M pyloroplasty could all prevent delayed gastric emptying effectively, and the incidence of bile reflux found by electronic gastroscopy in the PM group was significantly lower than that in the HM group (HM, 14/39; PM, 4/34; P = 0.028). In the animal experiment, there was no significant between-group difference of gastric emptying rate (%) in the HM group and PM group (HM, 70.6 ± 16; PM, 72.3 ± 12; P = 0.68) while the gastric emptying rate (%) was significantly lower in the V group than in the HM, PM, and control group (P values were 0.037, 0.021, and 0.001 respectively). The gastric mucosa bile acid concentration was significantly higher in the HM group than other group (P values were all less than 0.001).The pyloromyotomy could prevent delayed gastric emptying effectively after PG-EG for types II and III AEJ and reduce bile reflux compared to Heineke-Mikulicz pyloroplasty.

A facile scenario is proposed to design DBA-type molecules with E(T2) > E(S1) ≥ 2E(T1), promising to realize 200% exciton utilization through a three-step mechanism for organic electroluminescence.

Via pyridyl substitution at the 2,6-positions of anthracene, we achieved two packing polymorphs with different crystal morphologies and optical characteristics.

Singlet fission (SF) has drawn tremendous attention as a multiexciton generation process that could mitigate the thermal loss and boost the efficiency of solar energy conversion. Although a SF-based solar cell with an EQE above 100% has already been fabricated successfully, the practical efficiency of the corresponding devices is plagued by the limited scope of SF materials. Therefore, it is of great importance to design and develop new SF-capable compounds aiming at practical device application. In the current contribution

We realize multicolor microcrystalline lasers by engineering the excited-state overlap between the stimulated emission and triplet absorption based on the organic molecular design. These molecules possessing both high gain and potential high carrier transport behaviors can be attractive candidates for the electrically pumped organic laser.

A new NIR-emissive material composed of an organic fluorophore and porous starch for the visualization of latent-fingerprints with high resolution.

Current work unravels the distinctive conformational distortion-harnessed singlet fission process in thienoquinoid skeleton featuring the rapid generation and subsequent annihilation of intramolecular multiexciton dark state with 21A symmetry.

Background: Dysregulation of long non-coding RNAs (lncRNAs) expression plays pivotal roles in the initiation and progression of gastric cancer (GC). However, the regulation of lncRNA SNHG15 in GC has not been well studied. Mechanisms for ferroptosis by SNHG15 have not been revealed. Here, we aimed to explore SNHG15-mediated biological functions and underlying molecular mechanisms in GC progression. Methods: The novel SNHG15 was identified by analyzing RNA-sequencing (RNA-seq)data of GC tissues from our cohort and TCGA dataset, and further validated by qRT-PCR in GC cells and tissues. Gain- and loss-of-function assays were performed to examine the role of SNHG15 on GC both in vitro and in vivo. The regulatory mechanisms of SNHG15 were investigated by bioinformatics, RNA FISH, luciferase reporter assay, chromatin immunoprecipitation (ChIP), RNA pull-down, RIP-qPCR and luciferase assays. Results: SNHG15 was highly expressed in GC. The enhanced SNHG15 was positively correlated with malignant stage and poor prognosis in GC patients. Gain- and loss-of-function studies showed that SNHG15 was required for affecting cell growth, migration and invasion both in vitro and in vivo. Mechanistically, the oncogenic transcription factors E2F1 and MYC could bind to the SNHG15 promoter and enhanced its expression. Meanwhile, SNHG15 increased E2F1 and MYC mRNA expression by sponging miR-24-3p. Notably, SNHG15 could also enhance the stability of SLC7A11 in cytoplasm by competitively binding HNRNPA1. In addition, SNHG15 inhibited ferroptosis through a HNRNPA1-dependent regulation of SLC7A11/GPX4 axis. Conclusions: Our results support a novel model in which E2F1- and MYC-activated SNHG15 regulates ferroptosis via HNRNPA1-dependent modulation of SLC7A11/GPX4 axis serves as the critical effectors in GC progression, providing a new therapeutic direction in the treatment of GC.

Organic circularly polarized (CP) lasers have received increasing attention due to their future photoelectric applications. Here, we demonstrate a CP laser from a pure organic crystal-filled microcavity without any chiral molecules or chiral structures. Benefited from the giant anisotropy and excellent laser gain of organic crystals, optical Rashba-Dresselhaus spin-orbit coupling effect can be induced and is conductive to the CP laser in such microcavities. The maximum dissymmetry factor of the CP lasing with opposite helicities reached, is as high as 1.2. Our strategy may provide a new idea for the design of CP lasers towards future 3D laser displays, information storage and other fields.

Through the combination of transient spectroscopy and theoretical simulations, an accelerated singlet fission (SF) process was evidently observed in the strongly coupled H-type-like aggregation thin films of a dipyrrolonaphthyridinedione skeleton. Results elucidate that in this H-type-like aggregation, the substantially stabilized charge transfer (CT) state is close in energy with singlet and excimer states, resulting in a CT/excimer mixed state, which could drive excited-state population escaping from excimer trap and promote an ultrafast and highly efficient SF process. Our results not only enrich the limited capacity of SF materials but also contribute to an in-depth understanding of SF dynamics in H-type aggregation, which is of fundamental importance for designing new SF sensitizers and implementing practical SF applications.

Background: Helicobacter pylori (H. pylori) infection is the most common risk factor for gastric cancer (GC). The effect of the antioxidase manganese superoxide dismutase (SOD2 or MnSOD) in gastric tumorigenesis remains unclear. Methods: We explored the molecular and mechanical links between H. pylori, inflammation, and SOD2 in GC. RNA sequencing was conducted to identify the differentially expressed mRNAs between H. pylori-infected and uninfected cells. The putative role of SOD2 in gastric tumorigenesis in response to H. pylori infection was investigated in vitro and in vivo. Results: SOD2 is upregulated in GC. GC patients with high SOD2 expression clearly showed worse overall survival. H. pylori infection promoted SOD2 expression by activating the NF-κB signaling pathway. Knockdown of SOD2 led to increased levels of reactive oxygen species and oxidative stress in response to H. pylori infection. Meanwhile, the NF-κB binding site in the SOD2promoter region was evaluated through luciferase reporter and chromatin immunoprecipitation assays. SOD2 acted as an inhibitor of ferroptosis in GC cells, and SOD2 inhibition significantly sensitized GC cells to 5-fluorouracil treatment. Conclusions: Our results suggest that activation of the NF-κB pathway in GC cells infected with H. pylori leads to the upregulation of SOD2. Considering the prosurvival oncogenic features of SOD2 overexpression, our study further supports a novel relationship between infection, inflammation, and gastric carcinogenesis. Our results indicate that SOD2 may be a promising therapeutic candidate for GC.

The isolation of graphene from graphite triggered enormous interest in the study of 2D materials due to their remarkable physical properties. These 2D materials feature many unique properties, such as atomically thin flakes, a layered structure, a long-range order and a dangling bond-free surface, which are promising for broad applications in various fields including (opto)electronics, spintronics, catalysis and so on. Specially, organic 2D layered materials have the prominent advantage of their designable and tailorable chemical structure at the atomic level. The preparation of organic 2D layered material thin films has become a very hot research topic in the materials fields because of their great potential to be integrated into advanced nanodevices. Considering the lack of large single crystal samples, it is not possible to obtain large-scale films from the traditional top-down exfoliation methods. Various groups and our previous studies prove the efficiency of interfacial synthesis methods for high-quality organic 2D layered material thin film preparation by restricting the reaction at the two-phase boundary area within a plane. As the performance of resultant films is highly related to their "quality" in aspects of continuity, crystallinity, uniformity, and thickness, the selection of interfaces and conditions is vitally important. Until now, many interfacial synthesis methods have been developed and modified for the controlled growth of high-quality organic 2D layered material thin films. This feature article reviews the recent advances in organic 2D layered material thin film preparation by interfacial methods. First, how the features of the interface affect the growth behavior of organic 2D layered materials is analyzed. Then, varieties of organic 2D layered material thin films with different chemical structures grown at various interfaces are discussed. Finally, the challenges and prospects in the interfacial synthesis of high-quality organic 2D layered materials are also explored.

The development of high mobility organic laser semiconductors with strong emission is of great scientific and technical importance, but challenging. Herein, we present a high mobility organic laser semiconductor, 2,7-diphenyl-9H-fluorene (LD-1) showing unique crystallization-enhanced emission guided by elaborately modulating its crystal growth process. The obtained one-dimensional nanowires of LD-1 show outstanding integrated properties including: high absolute photoluminescence quantum yield (PLQY) approaching 80 %, high charge carrier mobility of 0.08 cm2 V-1 s-1 , Fabry-Perot lasing characters with a low threshold of 86 μJ cm-2 and a high-quality factor of ≈2400. Furthermore, electrically induced emission was obtained from an individual LD-1 crystal nanowire-based light-emitting transistor due to the recombination of holes and electrons simultaneously injected into the nanowire, which provides a good platform for the study of electrically pumped organic lasers and other related ultrasmall integrated electrical-driven photonic devices.

An organic light-emitting transistor (OLET) is a candidate device architecture for developing electrically pumped organic solid-state lasers, but it remains a critical challenge because of the lack of organic semiconductors that simultaneously possess a high solid-state emission efficiency (Φ

Erythromycin (ERY) is one of the most used antibiotics frequently detected in different aquatic environments and may bring burdens to aquatic ecosystems. However, the impacts of antibiotics on aquatic systems other than the antibiotic resistance genes remain largely unknown. In the present study, the responses to ERY exposure at the subcellular-organelle levels were for the first time investigated and imaged over 24 h. Exposure to ERY hampered the zebrafish (Danio rerio) cell growth and decreased the cell viability in a time-dependent mode. Meanwhile, exposure to a low concentration of ERY (73.4 μg L

Stimuli-responsive functional luminescent materials with tunable color and long-persistent emission have emerged as a powerful tool in information encryption, anticounterfeiting, and bioelectronics. Herein, we prove a novel strategy for manipulating the proton transfer pathways in the salicylaldehyde derivative EQCN solutions/powder to produce excitation wavelength-dependent (Ex-De) performances with switchable emissions (blue-sky, green, and orange). The experiments and theoretical results demonstrated that the different luminous colors are originated from enol (E) form (blue-sky), Keto-1 (K1) form (orange) through the excited-state intramolecular proton transfer (ESIPT) process, and Keto-2 (K2) form (green) through the excited-state long-range proton transfer (ESLRPT) process. We leverage synergistic effects between the dopant and matrix (dimethyl terephthalate, DTT) to manipulate the excited-state proton transfer pathway in EQCN@DTT mixture powders to generate Ex-De long-persistent luminescence (Ex-De-LPL), which can be well applied in multilevel information encryption. This strategy not only paves an intriguing way for the construction and preparation of pure organic Ex-De materials but also offers a guideline for developing LPL materials based on ESLRPT processes.

Organic gain materials (OGMs) currently used in organic lasers and optical amplifiers are focused on singlet-fluorescence materials, while triplet-phosphorescence-based OGMs have hardly been developed yet. Herein, we report a novel pure organic phosphorescence gain molecule (SBP) for optical amplification by stimulated emission from triplet states. The introduction of the benzophenone carbonyl group and sulfur atoms increases the spin orbit coupling constant of SBP, which accelerates the intersystem crossing (ISC) and phosphorescence processes. Experimental and theoretical results verify that the formation of the H-type dimer aggregate decreases the fluorescence radiation rate while accelerating the ISC rate, also enhancing the phosphorescence emission of SBP. Doping SBP molecules into a PMMA matrix can stabilize triplet excitons, yielding the maximum phosphorescence quantum yield of 18.9%. We realized triplet phosphorescent amplified spontaneous emission (ASE) at 557 nm from 30.0 wt % SBP@PMMA samples. Our results provide a novel strategy to develop triplet phosphor OGMs.

While manganese (Mn2+)-doped chalcogenide and perovskite CsPbX3 nanocrystals (NCs) have been extensively investigated, the research of color-tunable dual-emissive Mn2+-incorporated two-dimensional ...

Singlet fission (SF), the conversion of one high-energy singlet to two low-energy triplets, provides the potential to increase the efficiency of photovoltaic devices. In the SF chromophores with C2h symmetry, exemplified by polyenes, singlet-to-triplet conversion generally involves a low-lying 21Ag dark state, which serves as either a multiexciton (ME) intermediate to promote the SF process or a parasitic trap state to shunt excited-state populations via internal conversion. This controversial behavior calls for a deep understanding of dark-state-related photophysics involving the higher-lying singlet state. However, the optical "dark" and "transient" nature of these dark states and strong correlation feature of double exciton species make their characterization and interpretation challenging from both experimental and computational perspectives. In the present work combining transient spectroscopy and multireference electronic structure calculations (XDW-CASPT2), we addressed a new photophysical model, i.e., a high-lying 31Ag dark-state-mediated ultrafast SF process in the benzodipyrrolidone (BDPP) skeleton. Such a 31Ag dark state with distinctive double excitation character, described as the ME state, could be populated from the initial 11Bu bright state on an ultrafast time scale given the quasi-degeneracy and intersection of the two electronic states. Furthermore, the suitable optical band gap and triplet energy, high triplet yield, and excellent photostability render BDPP a promising SF candidate for photovoltaic devices. These results not only enrich the arsenal of SF materials but also shed new insights into the understanding of dark-state-related photophysics, which could promote the development of new SF-active materials.

Purpose This study aimed to develop a multi-long noncoding RNA (lncRNA) signature for the prediction of gastric cancer (GC) based on differential gene expression between recurrence and nonrecurrence patients. Methods By repurposing microarray expression profiles of RNAs from The Cancer Genome Atlas (TCGA), we performed differential expression analysis between recurrence and nonrecurrence patients. A prognostic risk prediction model was constructed based on data from TCGA database, and its reliability was validated using data from Gene Expression Omnibus database. Furthermore, the lncRNA-associated competing endogenous RNA (ceRNA) network was constructed, namely, DIANA-LncBasev2 and starBase database. Results We identified 363 differentially expressed RNAs (317 mRNAs, 18 lncRNAs, and 28 microRNAs [miRNAs]). Principal component analysis showed that the seven-feature lncRNAs screened by support vector machine–recursive feature elimination algorithm was more informative for predicting recurrence of GC in comparison with the eight-feature lncRNAs screened by random forest–out-of-bag algorithm. Four of the seven-feature lncRNAs including LINC00843, SNHG3, C21orf62-AS1, and MIR99AHG were chosen to develop a four-lncRNA risk score model. This risk score model was able to distinguish patients with high and low risk of recurrence, and was tested in two independent validation sets. The ceRNA network of this four-lncRNA signature included 10 miRNAs and 178 mRNAs. The mRNAs significantly related to the Wnt-signaling pathway and relevant biological processes. Conclusion A useful four-lncRNA signature recurrence was established to distinguish GC patients with high and low risk of recurrence. Regulating the relevant miRNAs and Wnt pathway might partly affect GC metastasisby.