Administration of USP7 inhibitor p22077 alleviates Angiotensin II (Ang II)-induced atrial fibrillation in Mice.

Atrial fibrillation (AF), the most common cardiac arrhythmia, is an important contributor to mortality and morbidity. Ubquitin-specific protease 7 (USP7), one of the most abundant ubiquitin-specific proteases (USP), participated in many cellular events, such as cell proliferation, apoptosis, and tumourigenesis. However, its role in AF remains unknown. Here, the mice were treated with Ang II infusion to induce the AF model. Echocardiography was used to measure the atrial diameter. Electrical stimulation was programmed to measure the induction and duration of AF. The changes in atrial remodeling were measured using routine histologic analysis. Here, a significant increase in USP7 expression was observed in Ang II-stimulated atrial cardiomyocytes and atrial tissues, as well as in atrial tissues from patients with AF. The administration of p22077, the inhibitor of USP7, attenuated Ang II-induced inducibility and duration of AF, atrial dilatation, connexin dysfunction, atrial fibrosis, atrial inflammation, and atrial oxidase stress, and then inhibited the progression of AF. Mechanistically, the administration of p22077 alleviated Ang II-induced activation of TGF-ß/Smad2, NF-κB/NLRP3, NADPH oxidases (NOX2 and NOX4) signals, the up-regulation of CX43, ox-CaMKII, CaMKII, Kir2.1, and down-regulation of SERCA2a. Together, this study, for the first time, suggests that USP7 is a critical driver of AF and revealing USP7 may present a new target for atrial fibrillation therapeutic strategies.

Enhancement of ester biosynthesis in blueberry wines through co-fermentation via cell-cell contact between Torulaspora delbrueckii and Saccharomyces cerevisiae.

This study investigated the effects of co-fermentation of T. delbrueckii and S. cerevisiae on the volatile composition and sensory characteristics of blueberry wines. Mixed fermentation led to higher levels of terpenes, higher alcohols, and esters compared to wines fermented with each yeast individually. Conversely, when T. delbrueckii were physically separated from S. cerevisiae in the double-compartment fermenter, contrasting outcomes emerged. The stronger fruity aroma induced by mixed fermentation were linked to higher ester concentrations, including isoamyl acetate, ethyl isovalerate, ethyl hexanoate, and diethyl succinate. The enhanced esters in mixed fermentation can be attributed to the upregulated alcohol acyltransferase activity and the expressions of ACC1, FAS2, ELO1 and ATF1 genes in late fermentation stage via the cell-cell contact between T. delbrueckii and S. cerevisiae. These findings can deepen the understanding of the interaction between non-Saccharomyces and S. cerevisiae in ester production, assisting wineries in effectively controlling wine aroma through mixed fermentations.

Continuous Ultrathin Zwitterionic Covalent Organic Framework Membrane Via Surface-Initiated Polymerization Toward Superior Water Retention.

Efficient construction of proton transport channels in proton exchange membranes maintaining conductivity under varied humidity is critical for the development of fuel cells. Covalent organic frameworks (COFs) hold great potential in providing precise and fast ion transport channels. However, the preparation of continuous free-standing COF membranes retaining their inherent structural advantages to realize excellent proton conduction performance is a major challenge. Herein, a zwitterionic COF material bearing positive ammonium ions and negative sulphonic acid ions is developed. Free-standing COF membrane with adjustable thickness is constructed via surface-initiated polymerization of COF monomers. The porosity, continuity, and stability of the membranes are demonstrated via the transmission electron microscopy (TEM), atomic force microscopy (AFM), and scanning electron microscopy (SEM) characterization. The rigidity of the COF structure avoids swelling in aqueous solution, which improves the chemical stability of the proton exchange membranes and improves the performance stability. In the higher humidity range (50-90%), the prepared zwitterionic COF membrane exhibits superior capability in retaining the conductivity compared to COF membrane merely bearing sulphonic acid group. The established strategy shows the potential for the application of zwitterionic COF in the proton exchange membrane fuel cells.

Production of Gibberellins via a Non-Natural Pathway Using Steviol as a Substrate.

Gibberellins (GAs) are plant hormones widely used in agriculture. At present, GAs are produced by fermentation of the fungus Fusarium fujikuroi. However, fungal growth is too slow, resulting in slow fungal fermentation and a low yield. Here, to develop an alternative production source of GAs, an artificial pathway was engineered in Escherichia coli. By selecting and combining enzymes derived from plants and bacteria, a novel 4-enzyme pathway was successfully constructed to produce GAs using steviol, a readily available and less valuable byproduct during enzymatic refining of rebaudioside A, as a feedstock. Whole-cell biotransformation with E. coli strain expressing the novel pathway produced 71.17 ± 2.00 mg/L GA1 and a trace amount of GA3 from steviol in 48 h. This report presents a significant advancement in the fast production of GAs and establishes a method for the metabolism of terpenoids to produce target products in microbial hosts.

Enhancing blueberry wine aroma: Insights from cultivar selection and berry sorting.

This study aimed to improve the aroma quality of blueberry wine by employing cultivar selection and precise berry sorting. We conducted a comprehensive analysis of volatile profiles in blueberry wines derived from nine cultivars commonly cultivated in the middle region of China. 'Misty' and 'V3' blueberry wines exhibited pronounced floral aromas, closely linked to elevated terpenoid and phenylacetaldehyde content. 'Legacy' and 'Star' displayed a distinct fruity aroma profile attributed to the presence of ethyl 2-methylbutyrate, ethyl phenylacetate, and diethyl succinate. 'Jewel' featured an intense buttery aroma, correlated with higher concentrations of ethyl dodecanoate, ethyl decanoate, and ethyl octanoate. Subsequently, 'Misty' and 'Star', with distinct aroma profiles, were selected to further unravel the impact of berry size on blueberry wine aroma. The findings revealed that small berries significantly enhanced 'Misty' blueberry wines, increasing higher alcohol, ester, and terpenoid content, resulting in a more intense fruity and floral aroma. Interestingly, berry size had no discernible influence on 'Star' blueberry wine aroma. This study provides valuable insights into the enhancement of blueberry wine production, shedding light on the intricate interplay of cultivar selection, berry sorting, and their impact on the aromatic attributes of the final product.

Development and Validation of Nomograms Based on Nutritional Risk Index for Predicting Extracapsular Extension and Seminal Vesicle Invasion in Patients Undergoing Radical Prostatectomy.

Background: The aim of the study was to investigate the predictive value of the nutritional risk index (NRI) for extracapsular extension (ECE) and seminal vesicle invasion (SVI) in prostate cancer (PCa) patients undergoing radical prostatectomy (RP), and further develop and validate predictive nomograms for ECE and SVI based on the NRI. Methods: We retrospectively analyzed 734 PCa patients who underwent RP between 2010 and 2020 in the Department of Urology at Peking University Third Hospital. The enrolled patients were randomly divided into a primary cohort (n = 489) and a validation cohort (n = 245) in a 2:1 manner. The baseline NRI of patients was calculated using serum albumin level and body mass index, and a malnutrition status was defined as NRI ≤ 98. Univariate and multivariate logistic regression analyses were conducted to identify predictors for ECE and SVI. Nomograms for predicting ECE and SVI were established based on the results of the multivariate logistic regression analysis. The performance of the nomograms was estimated using Harrell's concordance index (C-index), the area under curve (AUC) of receiver operating characteristic (ROC) curves and the calibration curves. Results: In the primary cohort, 70 (14.3%) patients with NRI ≤ 98 were classified as malnutrition, while the remaining 419 (85.7%) patients with NRI > 98 were considered to have normal nutrition. The nomograms for predicting ECE and SVI shared common factors including NRI, percentage of positive biopsy cores (PPC) and biopsy Gleason score, while prostate-specific antigen (PSA) levels and PSA density (PSAD) were only incorporated in ECE nomogram. The C-indexes of the nomograms for predicting ECE and SVI were 0.785 (95% confidence interval (CI): 0.745 - 0.826) and 0.852 (95% CI: 0.806 - 0.898), respectively. The calibration curves demonstrated excellent agreement between the predictions by the nomograms and the actual observations. The results remained reproducible when the nomograms were applied to the validation cohort. Conclusions: The NRI is significantly associated with ECE and SVI in PCa patients. The nomogram established based on the NRI in our study can provide individualized risk estimation for ECE and SVI in PCa patients, and may be valuable for clinicians in making well-informed decisions regarding treatment strategies and patient management.

[Estimation of Agricultural Greenhouse Gas Emissions and Emission Reduction Potential of Beijing During the 14th Five-Year Plan Period Under the Background of "Carbon Peak and Neutrality"].

To achieve the goal of "carbon peak and neutrality," the strict requirements for greenhouse gas (GHG) emissions control in the agricultural sector were recommended in relevant plans for Beijing during the 14th Five-Year Plan period. Through collecting agricultural activity data and calculating and screening the emission factors, the amount and emission characteristics of agricultural GHG emissions in Beijing in 2020 were estimated and set as the baseline condition. On this basis, the GHG emissions in 2025 with optimized measurements implemented, which were selected in combination with the natural conditions and planting-breeding mode of Beijing, were set as the reduction condition. The emission reduction potential and its distribution during the 14th Five-Year Plan Period were predicted simultaneously. Meanwhile, the reduction effects on the GHG emissions of optimized measurements were evaluated. In addition, relevant policy recommendations on GHG reduction were proposed accordingly. The results revealed that the total agricultural GHG emissions in Beijing were estimated to be 456000 t (CO2-eq) in 2020, primarily from sources of animal intestinal fermentation and manure management, with contribution rates of 50.7% and 26.7%, respectively. Spatially, it was mainly distributed in districts with large livestock and poultry breeding scales, such as Shunyi District, Miyun District, and Yanqing District, etc. It was predicted that in 2025, the total agricultural GHG emissions would be 349000 t (CO2-eq), and the emission reduction potential in the 14th Five-Year Plan period would be 107000 t (CO2-eq). Animal intestinal fermentation would be the emission source with the largest reduction potential (60000 tons, CO2-eq), followed by the emission source of animal manure management (37000 tons, CO2-eq). Adjusting fodder composition and optimizing manure management were analyzed to be the most effective optimized measurements for agricultural GHG emission reduction. Moreover, the emission reduction potential of CH4 would be greater than that of N2O. The emission reduction potential would be mainly distributed in Miyun District, Shunyi District, Yanqing District, Fangshan District, Tongzhou District, and other suburbs with large livestock and poultry breeding scales, accounting for more than 10% of the total emission reduction potential for each. These regions with large emission reduction potential should be prioritized and then the assessments should be extended to the whole city. The measurements were recommended as follows:① the research and promotion of technologies such as fodder optimization and the efficient treatment of manure should be strengthened, ② the scope of the combination of planting and breeding model should be expanded to promote the development of circular agriculture, and ③ relevant standards, guidelines, and specifications for green and low-carbon agriculture should be formulated, and the regulatory and policy system for synergy reduction of agricultural pollution and GHG should be developed.

Fluorescence microscope light source based on integrated LED.

An LED-integrated excitation cube (LEC) was designed to address the limitations of conventional fluorescence lamps. The LEC has a decentralized structure, high optical power density, and efficient illumination. The optical efficiency of LECs is 1-2 orders of magnitude higher than that of mercury lamps, enabling high-quality fluorescence imaging with spectral coverage from UV to red. LECs can be easily installed on commercial fluorescence microscopes by replacing conventional fluorescence filter cubes, and a built-in LEC driver can identify the types of LEDs in different spectral bands to adopt optimal operating conditions.

Knockdown of KIF15 suppresses proliferation of prostate cancer cells and induces apoptosis through PI3K/Akt signaling pathway.

Prostate cancer is one of the most common malignancies in men, which has been considered a public health threat. KIF15 is a kind of driver protein, and its abnormal expression is closely related to the occurrence and development of malignant tumors. The purpose of the study was to explore the significance and role of KIF15 in prostate cancer and to show some potential value for prostate cancer. Immunohistochemistry analysis showed that KIF15 was highly expressed in prostate cancer tissues, which was also positively correlated with T Infiltrate. The loss-of-function and gain-of-function assays based on prostate cancer cells indicated that the change in KIF15 expression could significantly affect cell proliferation, tumorigenesis, migration, and cell apoptosis. The inhibition of prostate cancer development by KIF15 knockdown was also assured in vivo. The Human Apoptosis Antibody Array showed that CD40L, cytoC, DR6, and p21 were up-regulated upon KIF15 knockdown, while IGF-I and Survivin were down-regulated. Moreover, the involvement of the PI3K/Akt pathway in the KIF15-mediated regulation of prostate cancer was preliminarily proved. In summary, KIF15 was identified to play an important role in the development or biological progress of prostate cancer and is considered to possess the potential to be used as a therapeutic target.

Causal inference between rheumatoid arthritis and prostate cancer.

It is unclear if the association between rheumatoid arthritis (RA) and a higher risk of prostate cancer (Pca) reflects a causal relationship. We conducted a meta-analysis and used the Mendelian randomization method (MR) to evaluate the association between RA and Pca risk. A meta-analysis and subgroup analysis of the incidence of Pca in patients with RA was conducted. To determine whether genetically elevated RA levels were causally linked to Pca, two MR samples were employed. To eliminate gender-related bias, we conducted a stratified analysis of the GWAS data for RA by gender, specifically including 140,254 males. Additional MR analysis was also performed to determine potential confounding factors influencing the association between genetically susceptible RA and Pca. In total, 409,950 participants were enrolled in 20 trials to investigate the Pca risk in patients with RA. The meta-analysis suggested that RA was unrelated to the Pca risk (SIR = 1.072, 95% CI, 0.883-1.261). However, a subgroup analysis showed that low smoking rates might increase the Pca risk in patients with RA by 24%. The MR analysis showed that increased genetic susceptibility to RA was related to a high Pca risk (OR = 36.20, 95%CI = 1.24-1053.12, P = 0.037). The causality estimation of MR-Egger, Weighted mode, Simple mode, and Weighted median method were similar in direction and magnitude. Although our meta-analysis found no correlation between RA and Pca risk, MR analyses supported a causal relationship between genetic susceptibility to RA and increased prostate risk. Early attention to Pca risk in patients with RA may be important for improving prognosis and mortality in such patients. Further research is needed to determine the etiology of RA attributed to Pca and its underlying mechanisms.

Diabetes, Obesity, and Pathological Upstaging in Renal Cell Carcinoma: Results From a Large Multi-institutional Consortium.

PURPOSE: We sought to determine whether clinical risk factors and morphometric features on preoperative imaging can be utilized to identify those patients with cT1 tumors who are at higher risk of upstaging (pT3a). MATERIALS AND METHODS: We performed a retrospective international case-control study of consecutive patients treated surgically with radical or partial nephrectomy for nonmetastatic renal cell carcinoma (cT1 N0) conducted between January 2010 and December 2018. Multivariable logistic regression models were used to study associations of preoperative risk factors on pT3a pathological upstaging among all patients, as well as subsets with those with preoperative tumors ≤4 cm, renal nephrometry scores, tumors ≤4 cm with nephrometry scores, and clear cell histology. We also examined association with pT3a subsets (renal vein, sinus fat, perinephric fat). RESULTS: Among the 4,092 partial nephrectomy and 2,056 radical nephrectomy patients, pathological upstaging occurred in 4.9% and 23.3%, respectively. Among each group independent factors associated with pT3a upstaging were increasing preoperative tumor size, increasing age, and the presence of diabetes. Specifically, among partial nephrectomy subjects diabetes (OR=1.65; 95% CI 1.17, 2.29), male sex (OR=1.62; 95% CI 1.14, 2.33), and increasing BMI (OR=1.03; 95% CI 1.00, 1.05 per 1 unit BMI) were statistically associated with upstaging. Subset analyses identified hilar tumors as more likely to be upstaged (partial nephrectomy OR=1.91; 95% CI 1.12, 3.16; radical nephrectomy OR=2.16; 95% CI 1.44, 3.25). CONCLUSIONS: Diabetes and higher BMI were associated with pathological upstaging, as were preoperative tumor size, increased age, and male sex. Similarly, hilar tumors were frequently upstaged.

AFM-Based Poroelastic@Membrane Analysis of Cells and its Opportunities for Translational Medicine.

Cell mechanics is an emerging field of research for translational medicine. Here, the cell is modeled as poroelastic cytoplasm wrapped by tensile membrane (poroelastic@membrane model) and is characterized by the atomic force microscopy (AFM). The parameters of cytoskeleton network modulus EC , cytoplasmic apparent viscosity ηC , and cytoplasmic diffusion coefficient DC are used to describe the mechanical behavior of cytoplasm, and membrane tension γ is used to evaluate the cell membrane. Poroelastic@membrane analysis of breast cells and urothelial cells show that non-cancer cells and cancer cells have different distribution regions and distribution trends in the four-dimensional space composed of EC , ηC . From non-cancer to cancer cells, there is often a trend of γ, EC , ηC decreases and DC increases. Patients with urothelial carcinoma at different malignant stages can be distinguished at high sensitivity and specificity by analyzing the urothelial cells from tissue or urine. However, sampling directly from tumor tissues is an invasive method, may lead to undesirable consequences. Thus, AFM-based poroelastic@membrane analysis of urothelial cells from urine may provide a non-invasive and no-bio-label method to detecting urothelial carcinoma.

Long-term outcomes after cytoreductive nephrectomy and thrombectomy of patients with metastatic renal cell carcinoma with venous tumor thrombus: a retrospective study from a large Chinese center.

BACKGROUND: Targeted therapy combined with immunotherapy is the current first-line treatment for metastatic renal cell carcinoma (mRCC), but patients with tumor thrombus (TT) may suffer from lower limb edema or even sudden cardiac death, so the purpose of this study is to investigate the efficacy and safety of surgical treatment in patients with mRCC and TT and explore worse factors to affect the prognosis in this series of patients. PATIENTS AND METHODS: A total of 85 mRCC patients with TT who received cytoreductive nephrectomy and thrombectomy at our medical center from 2014 to 2023 are included. All patients received postoperative systemic therapy. Overall survival (OS) is defined as the time from surgery to death due to any reason or the last follow-up. Kaplan-Meier analysis was performed to evaluate OS and differences among groups were tested by log-rank. Multivariable Cox proportional hazards analysis was performed to ascertain independent relationships between clinicopathological factors and OS. RESULTS: The median age of patients was 58 years old. Eleven patients (12.9%) had no symptoms, 39 patients (45.9%) had local symptoms, 15 patients (17.6%) had systemic symptoms, and 20 patients (23.5%) had both. Mayo grade of TT was 0, 1, 2, 3, and 4 for 12, 27, 31, 7, and 8 patients respectively. Fifty-five patients had lung metastasis, 23 had bone metastasis, 16 had liver metastasis, 13 had adrenal metastasis, and 9 had lymph node metastasis. Of all patients, 17 patients had multiple metastases. The median operation time is 289 min and the median intraoperative hemorrhage is 800 ml. Twenty-eight patients experienced postoperative complications, 8 of which were serious complications of modified Clavien grade III or higher. The median OS of all patients was 33 months and median follow up time was 26 months. In multivariate analysis, systemic symptom (p = 0.00753), pathological type (p = 0.0166), sarcomatous degeneration (p = 0.0334), and perirenal fat infiltration (p = 0.0202) are independent predictors of OS. CONCLUSION: Cytoreductive nephrectomy and thrombectomy is relatively safe and effective for patients with mRCC accompanied by TT. In this series of patients, the worse prognosis is associated with systemic symptoms, non-clear cell carcinoma, sarcomatous degeneration and perirenal fat infiltration.

Aroma enhancement of blueberry wine by postharvest partial dehydration of blueberries.

Blueberries with 20%, 30%, and 40% weight loss were used for winemaking, aiming to explore the feasibility of applying postharvest dehydration for improving blueberry wine aroma. Postharvest dehydration decreased the titratable acidity of blueberries and their resultant wines. Total anthocyanins and phenols in blueberries with 30% weight loss were increased by 25.9% and 16.1%, respectively, due to concentration effects, while further dehydration resulted in a decline. Similar trends were observed in blueberry wines. Moderate postharvest dehydration increased total terpenes, benzeneacetaldehyde and phenylethyl alcohol, ethyl butanoate, methyl salicylate, 1-hexanol, and γ-nonalactone content in blueberries and wines, which could enhance the floral, fruity, and sweet notes of blueberry wines. Wines made from blueberries under severe dehydration (40% weight loss) had the lowest overall aroma score, which was related to the higher content of 4-ethyl-phenol and 4-ethylguaiacol. In conclusion, moderate postharvest dehydration benefited the aroma enhancement of blueberry wine.

Correction: Crystalline matrix-activated spin-forbidden transitions of engineered organic crystals.

Correction for 'Crystalline matrix-activated spin-forbidden transitions of engineered organic crystals' by Heming Zhang et al., Phys. Chem. Chem. Phys., 2023, 25, 11102-11110, DOI: https://doi.org/10.1039/d3cp00187c.

Cephalic inferior vena cava non-clamping technique versus standard procedure for robot-assisted laparoscopic level II-III thrombectomy: a prospective cohort study.

BACKGROUND: Renal tumour can invade the venous system and ~4-10% patients with renal tumour had venous thrombus. Although the feasibility of robot-assisted laparoscopic inferior vena cava thrombectomy (RAL-IVCT) in patients with inferior vena cava (IVC) thrombus has been validated, the wide application is still a challenge due to the complexity of IVC control. The objective was to describe our novel cephalic IVC non-clamping technique and to compare the outcomes versus standard RAL-IVCT. MATERIALS AND METHODS: A prospective single-centre cohort containing 30 patients with level II-III IVC thrombus was established since August 2020. Fifteen patients underwent cephalic IVC non-clamping approach and 15 patients received standard RAL-IVCT. The authors decided the surgical technique according to the echocardiographic assessment of the right heart and IVC. RESULTS: The non-clamping group had less operative time (median 148 versus 185 min, P =0.04), and lower Clavien-grade II complication rate (26.7% versus 80.0%, P =0.003). The median intraoperative blood loss were 400 ml [interquartile range (IQR) 275-615 mL] and 800 ml (IQR 350-1300 ml), respectively ( P =0.05). The most common complication in standard RAL-IVCT group was liver dysfunction. No gas embolism, hypercapnia or tumour thrombus dislodgment occurred in non-clamping group. After a median follow-up of 17.0 months (IQR 13.5-18.5 months) and 15.5 months (IQR 13.0-17.0 months), two patients (16.7%) in the non-clamping group and 3 patients (20.0%) in the standard RAL-IVCT group died (hazard ratio 0.59, 95% CI 0.10-3.54, P =0.55). CONCLUSIONS: The cephalic IVC non-clamping technique can be performed safely with acceptable surgical outcomes and short-term oncologic outcomes in patients with level II-III IVC thrombus. Compared with standard procedure, it had less operative time and lower complication rate.

Systemic lupus erythematosus and prostate cancer risk: a pool of cohort studies and Mendelian randomization analysis.

BACKGROUND: Current observational studies suggest that there may be a causal relationship between systemic lupus erythematosus (SLE) and prostate cancer (PC). However, there is contradictory evidence. This study aimed to investigate and clarify the association between SLE and PC. METHODS: We searched PubMed, Embase, Web of Science, and Scopus until May 2022. A meta-analysis was conducted on the standard incidence rate (SIR) and 95% CI. Subgroup analysis was performed based on the follow-up duration, study quality, and appropriate SLE diagnosis. Mendelian randomization (MR) of the two samples was used to determine whether genetically elevated SLE was causal for PC. Summary MR data were obtained from published GWASs, which included 1,959,032 individuals. The results were subjected to sensitivity analysis to verify their reliability. RESULTS: In a meta-analysis of 79,316 participants from 14 trials, we discovered that patients with SLE had decreased PC risk (SIR, 0.78; 95% CI, 0.70-0.87) significantly. The MR results showed that a one-SD increase in genetic susceptibility to SLE significantly reduced PC risk (OR, 0.9829; 95% CI, 0.9715-0.9943; P = 0.003). Additional MR analyses suggested that the use of immunosuppressants (ISs) (OR, 1.1073; 95% CI, 1.0538-1.1634; P < 0.001), but not glucocorticoids (GCs) or non-steroidal anti-inflammatory drugs (NSAIDs), which were associated with increased PC risk. The results of the sensitivity analyses were stable, and there was no evidence of directional pleiotropy. CONCLUSIONS: Our results suggest that patients with SLE have a lower risk of developing PC. Additional MR analyses indicated that genetic susceptibility to the use of ISs, but not GCs or NSAIDs, was associated with increased PC risk. This finding enriches our understanding of the potential risk factors for PC in patients with SLE. Further study is required to reach more definitive conclusions regarding these mechanisms.

Crystalline matrix-activated spin-forbidden transitions of engineered organic crystals.

Spin-forbidden excitation is an efficient way to obtain triplet excitons directly from the ground state of organic semiconductors. According to perturbation theory under the framework of Fermi's golden rule, this process requires spin-orbit coupling (SOC) and the transition dipole moment (TDM) to be combined through an intermediate state that mixes the initial and final states. While previous research has focused mostly on enhancing SOC, little attention has been paid to engineering the coupling between SOC and the TDM in organic materials. In this study, a series of engineered crystals were designed by doping guest molecules into host organic crystals. The confinement of the guest molecule within a crystalline matrix of the host provides a strong intermolecular interaction to couple both SOC and the TDM. This in turn activates the spin-forbidden excitation directly from the ground state to a "dark" triplet state. Based on a comparison of different engineered crystals, strong intermolecular interaction is identified to induce a distortion of the ligands and further enhancing the spin-forbidden excitation. This work outlines a strategy for designing spin-forbidden excitation.

Toward Narrowband and Efficient Blue Fluophosphors by Locking the Stretching Vibration of Indolocarbazole Skeletons.

Developing efficient and color-saturated deep-blue emitting molecules with small Commission Internationale de L'Eclairage (CIE) y values is challenging and has great potential for wide-color gamut displays. Herein, we introduce an intramolecular locking strategy to restrain molecular stretching vibrations of the emission spectral broadening. By cyclizing rigid fluorenes and connecting electron-donating groups to the indolo[3,2,1-jk]-indolo[1',2',3':1,7]indolo[2,3-b]carbazole (DIDCz) framework, the in-plane swing of peripheral bonds and stretching vibrations of the indolocarbazole skeleton are restricted due to an increased steric hindrance from cyclized groups and diphenylamine auxochromophores. As a result, reorganization energies at the high-frequency region (1300-1800 cm-1) are reduced, realizing pure blue emission with a small full-width-at-half-maximum (FWHM) of 30 nm by suppressing shoulder peaks of polycyclic aromatic hydrocarbon (PAH) frameworks. The fabricated bottom-emitting organic light-emitting diode (OLED) exhibits an efficient external quantum efficiency (EQE) of 7.34% and deep-blue coordinates of (0.140, 0.105) at a high brightness of 1000 cd/m2. The FWHM of the electroluminescent spectrum is only 32 nm, which is one of the narrowest electroluminescent emissions among the reported intramolecular charge transfer fluophosphors. Our current findings provide a new molecular design strategy to conceive efficient and narrowband emitters with small reorganization energies.