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1.
J Am Chem Soc ; 146(19): 13326-13335, 2024 May 15.
Article En | MEDLINE | ID: mdl-38693621

A key challenge in the search of new materials capable of singlet fission (SF) arises from the primary energy conservation criterion, i.e., the energy of the triplet exciton has to be half that of the singlet (E(S1) ≥ 2E(T1)), which excludes most photostable organic materials from consideration and confines the design strategy to materials with low energy triplet states. One potential way to overcome this energy requirement and improve the triplet energy is to enable a SF channel from higher energy ("hot") excitonic states (Sn) in a process called activated SF. Herein, we demonstrate that efficient activated SF is achieved in a rylene imide-based derivative acenaphth[l, 2-a]acenaphthylene diimide (AADI). This process is enabled by an increase in the energy gap to greater than 1.0 eV between the S3 and S1 states due to the incorporation of an antiaromatic pentalene unit, which leads to the emergence of anti-Kasha properties in the isolated molecule. Transient spectroscopy studies show that AADI undergoes ultrafast SF from higher singlet excited states in thin film, with excitation wavelength-dependent SF yields. The SF yield of ∼200% is observed upon higher energy excitation, and long-lived free triplets persist on the µs time scale suggesting that AADI can be used in SF-enhanced devices. Our results suggest that enlarging the Sn-S1 energy gap is an effective way to turn on the activated SF channel and shed light on the development of novel, stable SF materials with high triplet energies.

2.
Aging (Albany NY) ; 16(9): 8070-8085, 2024 May 08.
Article En | MEDLINE | ID: mdl-38728249

BACKGROUND: Inflammation is one of the significant consequences of ox-LDL-induced endothelial cell (EC) dysfunction. The senescence-associated secretory phenotype (SASP) is a critical source of inflammation factors. However, the molecular mechanism by which the SASP is regulated in ECs under ox-LDL conditions remains unknown. RESULTS: The level of SASP was increased in ox-LDL-treated ECs, which could be augmented by KLF4 knockdown whereas restored by KLF4 knock-in. Furthermore, we found that KLF4 directly promoted PDGFRA transcription and confirmed the central role of the NAPMT/mitochondrial ROS pathway in KLF4/PDGFRA-mediated inhibition of SASP. Animal experiments showed a higher SASP HFD-fed mice, compared with normal feed (ND)-fed mice, and the endothelium of EC-specific KLF4-/- mice exhibited a higher proportion of SA-ß-gal-positive cells and lower PDGFRA/NAMPT expression. CONCLUSIONS: Our results revealed that KLF4 inhibits the SASP of endothelial cells under ox-LDL conditions through the PDGFRA/NAMPT/mitochondrial ROS. METHODS: Ox-LDL-treated ECs and HFD-fed mice were used as endothelial senescence models in vitro and in vivo. SA-ß-gal stain, detection of SAHF and the expression of inflammatory factors determined SASP and senescence of ECs. The direct interaction of KLF4 and PDGFRA promotor was analyzed by EMSA and fluorescent dual luciferase reporting analysis.


Cellular Senescence , Endothelial Cells , Kruppel-Like Factor 4 , Kruppel-Like Transcription Factors , Lipoproteins, LDL , Mitochondria , Reactive Oxygen Species , Receptor, Platelet-Derived Growth Factor alpha , Kruppel-Like Factor 4/metabolism , Animals , Kruppel-Like Transcription Factors/metabolism , Kruppel-Like Transcription Factors/genetics , Reactive Oxygen Species/metabolism , Cellular Senescence/drug effects , Mitochondria/metabolism , Lipoproteins, LDL/metabolism , Lipoproteins, LDL/pharmacology , Mice , Receptor, Platelet-Derived Growth Factor alpha/metabolism , Receptor, Platelet-Derived Growth Factor alpha/genetics , Humans , Endothelial Cells/metabolism , Cytokines/metabolism , Phenotype , Mice, Knockout , Human Umbilical Vein Endothelial Cells/metabolism , Male , Signal Transduction
3.
J Chem Phys ; 160(16)2024 Apr 28.
Article En | MEDLINE | ID: mdl-38666791

Photoinduced symmetry-breaking charge separation (SB-CS) has been extensively observed in various oligomers and aggregates, which holds great potential for robust artificial solar energy conversion systems. It attaches great importance to the precise manipulation of interchromophore electronic coupling in realizing efficient SB-CS. The emerging studies on SB-CS suggested that it could be realized in null-excitonic aggregates, and a long-lived SB-CS state was observed, which offers an advanced platform and has gathered immense attention in the SB-CS field. Here, we unveiled the null-exciton coupling induced ultrafast SB-CS in a rigid polycyclic aromatic hydrocarbon framework, triperyleno[3,3,3]propellane triimides (TPPTI), in which three chromophores were attached through a nonconjugated bridge. Through a combination of theoretical calculations and steady-state absorption results, we demonstrated that this nonconjugated TPPTI possesses negligible exciton coupling. Increased solvent polarity was found to significantly enhance state mixing between local excited and charge transfer states. Using transient absorption spectroscopy, ultrafast SB-CS was observed in highly polar dimethylformamide, facilitated by a selective hole-transfer coupling and a favorable charge separation free energy (ΔGCS). Additionally, the rate ratio between SB-CS and charge recombination was at least high to 1800 in dimethylformamide. This investigation provides profound insights into the role of null-exciton coupling in dominating ultrafast SB-CS in multichromophoric systems.

4.
J Phys Chem B ; 128(16): 3964-3971, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38602495

The properties and formation mechanisms of the triplet state have been widely investigated since they are crucial intermediates in photo functional devices. Specifically, helical PDI dimers, horizontal expanded π-conjugated derivatives of PDI, have shown outstanding performance as electron acceptors in enhancing the performance of photovoltaics. Therefore, the exploration of triplet generation in helical PDI dimers plays a crucial role in understanding the mechanisms and excavating their further application. We make use of Se-annulation to induce intersystem crossing (ISC) in helical PDI dimers and further explore the triplet evolution process systematically as the number of Se atoms increases by transient absorption spectroscopy and the hole-electron analysis method. It shows that the twisted molecular conformation has paved the way for potential ISC in a parent molecule PDI2. The incorporation of Se atoms can result in evident promotion in the efficiency of ISC (ϕTPDI2-2Se = 96.9%) compared to the parent molecule PDI2 (ϕTPDI2 = 26.5%), indicating that chalcogen-annulation is also an efficient strategy in a π-extended system. Our results provide useful insights for understanding the triplet evolution process, which can help broaden the application of the π-extended PDI system into high-performance photovoltaics.

5.
Redox Biol ; 72: 103154, 2024 Jun.
Article En | MEDLINE | ID: mdl-38626575

Continuous remodeling of the heart can result in adverse events such as reduced myocardial function and heart failure. Available evidence indicates that ferroptosis is a key process in the emergence of cardiac disease. P2 family purinergic receptor P2X7 receptor (P2X7R) activation plays a crucial role in numerous aspects of cardiovascular disease. The aim of this study was to elucidate any potential interactions between P2X7R and ferroptosis in cardiac remodeling stimulated by angiotensin II (Ang II), and P2X7R knockout mice were utilized to explore the role of P2X7R and elucidate its underlying mechanism through molecular biological methods. Ferroptosis is involved in cardiac remodeling, and P2X7R deficiency significantly alleviates cardiac dysfunction, remodeling, and ferroptosis induced by Ang II. Mechanistically, Ang II interacts with P2X7R directly, and LYS-66 and MET-212 in the in the ATP binding pocket form a binding complex with Ang II. P2X7R blockade influences HuR-targeted GPX4 and HO-1 mRNA stability by affecting the shuttling of HuR from the nucleus to the cytoplasm and its expression. These results suggest that focusing on P2X7R could be a possible therapeutic approach for the management of hypertensive heart failure.


Angiotensin II , Ferroptosis , Receptors, Purinergic P2X7 , Receptors, Purinergic P2X7/metabolism , Receptors, Purinergic P2X7/genetics , Animals , Angiotensin II/metabolism , Mice , Humans , Mice, Knockout , Ventricular Remodeling , Myocardium/metabolism , Myocardium/pathology , Male , Protein Binding , Heart Failure/metabolism , Heart Failure/pathology , Heart Failure/genetics
6.
Angew Chem Int Ed Engl ; 63(18): e202400941, 2024 Apr 24.
Article En | MEDLINE | ID: mdl-38458974

The development of innovative triplet materials plays a significant role in various applications. Although effective tuning of triplet formation by intersystem crossing (ISC) has been well established in solution, the modulation of ISC processes in the solid state remains a challenge due to the presence of other exciton decay channels through intermolecular interactions. The cyclic structure of cycloparaphenylenes (CPPs) offers a unique platform to tune the intermolecular packing, which leads to controllable exciton dynamics in the solid state. Herein, by integrating an electron deficient coronene diimide (CDI) unit into the CPP framework, a donor-acceptor type of conjugated macrocycle (CDI-CPP) featuring intramolecular charge-transfer (CT) interaction was designed and synthesized. Effective intermolecular CT interaction resulting from a slipped herringbone packing was confirmed by X-ray crystallography. Transient spectroscopy studies showed that CDI-CPP undergoes ISC in both solution and the film state, with triplet generation time constants of 4.5 ns and 238 ps, respectively. The rapid triplet formation through ISC in the film state can be ascribed to the cooperation between intra- and intermolecular charge-transfer interactions. Our results highlight that intermolecular CT interaction has a pronounced effect on the ISC process in the solid state, and shed light on the use of the characteristic structure of CPPs to manipulate intermolecular CT interactions.

7.
Article En | MEDLINE | ID: mdl-38231821

Previous studies have proven that circular RNAs (circRNAs) are inextricably connected to the etiology and pathophysiology of complicated diseases. Since conventional biological research are frequently small-scale, expensive, and time-consuming, it is essential to establish an efficient and reasonable computation-based method to identify disease-related circRNAs. In this article, we proposed a novel ensemble model for predicting probable circRNA-disease associations based on multi-source similarity information(LMGATCDA). In particular, LMGATCDA first incorporates information on circRNA functional similarity, disease semantic similarity, and the Gaussian interaction profile (GIP) kernel similarity as explicit features, along with node-labeling of the three-hop subgraphs extracted from each linked target node as graph structural features. After that, the fused features are used as input, and further implied features are extracted by graph sampling aggregation (GraphSAGE) and multi-hop attention graph neural network (MAGNA). Finally, the prediction scores are obtained through a fully connected layer. With five-fold cross-validation, LMGATCDA demonstrated excellent competitiveness against gold standard data, reaching 95.37% accuracy and 91.31% recall with an AUC of 94.25% on the circR2Disease benchmark dataset. Collectively, the noteworthy findings from these case studies support our conclusion that the LMGATCDA model can provide reliable circRNA-disease associations for clinical research while helping to mitigate experimental uncertainties in wet-lab investigations.


Neural Networks, Computer , RNA, Circular , RNA, Circular/genetics , Algorithms , Computational Biology/methods
8.
Macromol Rapid Commun ; 45(1): e2300241, 2024 Jan.
Article En | MEDLINE | ID: mdl-37548255

Singlet fission (SF) is a spin-allowed process in which a higher-energy singlet exciton is converted into two lower-energy triplet excitons via a triplet pair intermediate state. Implementing SF in photovoltaic devices holds the potential to exceed the Shockley-Queisser limit of conventional single-junction solar cells. Although great progress has been made in exploiting the underlying mechanism of SF over the past decades, the scope of materials capable of SF, particularly polymeric materials, remains poor. SF-capable polymer is one of the most potential candidates in the implementation of SF into devices due to their distinct superiorities in flexibility, solution processability and self-assembly behavior. Notably, recent advancements have demonstrated high-performance SF in isolated donor-acceptor (D-A) copolymer chains. This review provides an overview of recent progress in the development of SF-capable polymeric materials, with a significant focus on elucidating the mechanisms of SF in polymers and optimizing the design strategies for SF-capable polymers. Additionally, the paper discusses the challenges encountered in this field and presents future perspectives. It is expected that this comprehensive review will offer valuable insights into the design of novel SF-capable polymeric materials, further advancing the potential for SF implementation in photovoltaic devices.


Polymers
9.
BMC Cardiovasc Disord ; 23(1): 470, 2023 09 20.
Article En | MEDLINE | ID: mdl-37730550

Myocardial infarction (MI) is a leading cause of mortality. To better understand its molecular and cellular mechanisms, we used bioinformatic tools and molecular experiments to explore the pathogenesis and prognostic markers. Differential gene expression analysis was conducted using GSE60993 and GSE66360 datasets. Hub genes were identified through pathway enrichment analysis and PPI network construction, and four hub genes (AQP9, MMP9, FPR1, and TREM1) were evaluated for their predictive performance using AUC and qRT-PCR. miR-206 was identified as a potential regulator of TREM1. Finally, miR-206 was found to induce EC senescence and ER stress through upregulating mitochondrial ROS levels via TREM1. These findings may contribute to understanding the pathogenesis of MI and identifying potential prognostic markers.


MicroRNAs , Myocardial Infarction , Humans , Triggering Receptor Expressed on Myeloid Cells-1/genetics , Reactive Oxygen Species , Mitochondria , Myocardial Infarction/genetics , MicroRNAs/genetics
10.
Biosens Bioelectron ; 239: 115601, 2023 Nov 01.
Article En | MEDLINE | ID: mdl-37633000

Effective and convenient detection of melanoma cells with high sensitivity is essential to identify malignant melanoma in its early stage. However, the existing detection methods, such as immunohistochemical analysis, are too complicated and time-consuming to realize the convenient in vivo and in situ detection. Herein, a near infrared responsive photoelectrochemical (PEC) immunosensor is proposed with plasmonic Au nanoparticles-photonic TiO2 nanocaves (Au/TiO2 NCs) as photon harvest and conversion transducer and antibody as cell recognition unit. The micro-antibody/Au/TiO2 NCs photoelectrode can easily in vivo distinguish melanoma cells and can realize sensitive detection of melanoma cells in short time of 1 min with a lowest limit of detection of 2 cell mL-1. The PEC immunosensor strategy not only allows us to pioneeringly implement sensitive in vivo bio-detection, but also opens up a new avenue for rational design of cell recognition units and micro-electrode for universal and reliable bio-detections.


Biosensing Techniques , Immunoassay , Melanoma , Immunoassay/methods , Spectroscopy, Near-Infrared/methods , Photochemistry/methods , Melanoma/chemistry , Melanoma/diagnosis , Gold , Metal Nanoparticles , Humans , Animals , Mice , Cell Line, Tumor , Biosensing Techniques/methods
11.
J Surg Oncol ; 128(8): 1394-1406, 2023 Dec.
Article En | MEDLINE | ID: mdl-37642010

BACKGROUND: To investigate the difference in efficacy of re-excision in synovial sarcoma patients with and without residual tumor following unplanned excision, and to compare the prognostic outcomes of immediate re-excision versus waiting for local recurrence. METHOD: This study included synovial sarcoma patients who underwent re-excision at our center between 2009 and 2019, categorized into groups based on unplanned excision and local recurrence. Analyzed endpoints included overall survival (OS), local recurrence-free survival (LRFS), and distant relapse-free survival (DRFS). Prognostic factors associated with these three different survival outcomes were analyzed through the use of Kaplan-Meier curves and Cox regression approaches. RESULT: In total, this study incorporated 109 synovial sarcoma patients, including 32 (29.4%) with no residual tumor tissue identified after re-excision, 31 (28.4%) with residual tumor tissue after re-excision, and 46 (42.2%) with local recurrence after initial excision. Patients were assessed over a median 52-month follow-up period. The respective 5-year OS, 5-year LRFS, and 5-year DRFS rates were 82.4%, 76.7%, and 74.2% for the nonresidual group, 80.6%, 80.4%, and 77.3% for the residual tumor tissue group, and 63.5%, 50.7%, and 46.3% for the local recurrence group. There was no significant difference in OS of nonresidual group and residual group patients after re-excision (p = 0.471). Concurrent or sequential treatment with chemotherapy and radiotherapy significantly reduced the risk of metastasis and mortality when compared with noncombined chemoradiotherapy, and was more effective in the local recurrence group (p < 0.05). CONCLUSION: Prompt and adequate re-excision is crucial for patients with synovial sarcoma who undergo initial inadequate tumor excision, and their prognosis is significantly better compared with patients who delay re-excision until local recurrence.


Sarcoma, Synovial , Sarcoma , Soft Tissue Neoplasms , Humans , Sarcoma, Synovial/surgery , Neoplasm, Residual/pathology , Sarcoma/pathology , Neoplasm Recurrence, Local/surgery , Neoplasm Recurrence, Local/pathology , Prognosis , Retrospective Studies , Treatment Outcome , Soft Tissue Neoplasms/surgery
12.
Article En | MEDLINE | ID: mdl-37151068

BACKGROUND: The improvements in the treatment of colorectal cancer (CRC) and prolongation of survival time have improved the incidence of bone metastasis. Forkhead box D3 (FOXD3) is involved in the development of CRC. However, the role and mechanism of FOXD3 in CRC bone metastases development are unknown. OBJECTIVE: Using the combined bioinformatics and cytology experimental analyses, this study aimed to explore the mechanistic role of FOXD3 in the bone metastasis of colon cancer, thereby aiding in the treatment of colon cancer bone metastasis and identification of drug-targeting markers. METHODS: First, the changes in the expression levels of the FOXD3 gene and differentially expressed genes (DEGs) between the colon cancer samples and colon cancer metastases were obtained from The Cancer Genome Atlas (TCGA) database. Then, the correlations of the FOXD3 gene with the DEGs were identified. Next, the effects of the FOXD3 on the proliferation and invasion abilities of colon cancer bone metastatic cells were identified using Cell Counting Kit-8 (CCK8) and Transwell cell migration assays, respectively. In addition, Western blot analysis was used to identify the expression levels of the proteins related to the EGFR/Ras/Raf/MEK/ERK(EGFR/ERK) signaling pathway and epithelial-to-mesenchymal transition (EMT). RESULTS: FOXD3 was downregulated in colon cancer and could interact with multiple DEGs in colon cancer bone metastases. FOXD3 gene knockdown could increase the proliferation of human colon cancer bone metastatic cells and their invasive ability. FOXD3 gene knockdown could activate the expression of EGFR/ERK signaling pathway-related proteins and inhibit/promote the expression of EMT-related proteins, which in turn promoted the proliferation and metastasis of LoVo cells from colon cancer bone metastases. CONCLUSION: Overall, this study demonstrated that the downregulation of the FOXD3 gene might promote the proliferation of colon cancer bone metastatic cell lines through the EGFR/ERK pathway and promote their migration through EMT, thereby serving as a promising therapeutic target.

13.
J Phys Chem Lett ; 14(20): 4822-4829, 2023 May 25.
Article En | MEDLINE | ID: mdl-37191450

Bay-annulated indigo (BAI) is a new potential SF-active building block, which has aroused great interest in the design of highly stable singlet fission materials. However, singlet fission of unfunctionalized BAI is inactive due to the inappropriate energy levels. Herein, we seek to develop a new design strategy by introducing the charge transfer interaction to tune the exciton dynamics of BAI derivatives. A new donor-acceptor molecule (TPA-2BAI) and two control molecules (TPA-BAI and 2TPA-BAI) were designed and synthesized to unravel the veil of CT states in tuning the excited-state dynamics of BAI derivatives. Transient absorption spectroscopy studies show that CT states are generated immediately following the excitation. However, the low-lying CT states induced by strong donor-acceptor interactions result in them acting as trap states and inhibiting the SF process. These results show that the low-lying CT state is detrimental to SF and provide insight into the design of CT-mediated BAI-based SF materials.

14.
J Phys Chem Lett ; 14(13): 3249-3257, 2023 Apr 06.
Article En | MEDLINE | ID: mdl-36975134

The development of antenna molecules with simplified structures can effectively avoid the complex exciton dynamics resulting from conformational mobility. Two distinct heterodimers TP and TBP comprising a perylenediimide (PDI) donor and terrylenediimide (TDI) acting as an energy sink were investigated. Tuned by varying functionalization positions, the bay-to-bay-linked TP offers a strong chromophore coupling, while the bay-to-N-linked TBP exhibits a weak chromophore coupling. Using transient absorption spectroscopy, we found that TP underwent ultrafast vibrational relaxation (τVR < 400 fs) from upper vibrational energy levels of the singlet states after pumping at 490 nm, and followed by electron transfer (ET, τET = 2.5 ps) from TDI to PDI. TBP exhibited ultrafast excitation energy transfer (EET, τEET = 0.48 ± 0.1 ps) from the excited PDI donor to TDI acceptor, and the subsequent charge transfer (CT) process was almost quenched. This result provides insight into designing novel small molecules capable of efficient energy transfer.

15.
Bioinformatics ; 39(2)2023 02 03.
Article En | MEDLINE | ID: mdl-36661313

MOTIVATION: In single-cell transcriptomics applications, effective identification of cell types in multicellular organisms and in-depth study of the relationships between genes has become one of the main goals of bioinformatics research. However, data heterogeneity and random noise pose significant difficulties for scRNA-seq data analysis. RESULTS: We have proposed an adversarial dense graph convolutional network architecture for single-cell classification. Specifically, to enhance the representation of higher-order features and the organic combination between features, dense connectivity mechanism and attention-based feature aggregation are introduced for feature learning in convolutional neural networks. To preserve the features of the original data, we use a feature reconstruction module to assist the goal of single-cell classification. In addition, HNNVAT uses virtual adversarial training to improve the generalization and robustness. Experimental results show that our model outperforms the existing classical methods in terms of classification accuracy on benchmark datasets. AVAILABILITY AND IMPLEMENTATION: The source code of HNNVAT is available at https://github.com/DisscLab/HNNVAT. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Neural Networks, Computer , Software , Benchmarking , Single-Cell Analysis
16.
Article En | MEDLINE | ID: mdl-36508948

The present study was conducted to investigate the regulatory mechanism of liver injury in largemouth bass Micropterus salmoides (LMB) fed low protein high starch diets. Two isolipidic and isoenergetic diets were formulated with different protein and starch ratios, being named as diets P49S9 (48.8 % protein and 9.06 % starch) and P42S18 (42.4 % protein and 18.2 % starch). Each diet was fed to triplicate replicates of LMB (initial body weight, 4.65 ± 0.01 g) juveniles. Fish were fed to visual satiation for 8 weeks. The results indicated that though the P42S18 fish up-regulated the feeding ratio to meet their protein requirements, feeding efficiency ratio and growth performance were impaired in treatment P42S18 as compared to treatment P49S9. Periodic acid-Schiff (PAS) staining showed glycogen accumulated in the liver of LMB fed low protein high starch diets, and the reason should be attributed to down-regulated expression of the glycogenolytic glycogen debranching enzyme. Lower liver lipid level was associated with feeding low protein high starch diets in LMB, which should be resulted from the changes in hepatic glycerolipid metabolism regulated by lipoprotein lipase (representative of triglyceride synthesis, up-regulated) and diacylglycerol acyltransferase (representative of triglyceride breakdown, down-regulated). Though fasting plasma glucose level was comparable, treatment P42S18 performed inferior glucose tolerance to treatment P49S9. Hematoxylin-eosin (HE) and TdT-mediated dUTP Nick-End Labeling (TUNEL) staining suggested that feeding low protein high starch diets induced disruption of structural integrity, inflammation and apoptosis in the hepatocytes of LMB. As expected, KEGG pathways analysis indicated that many of the up-regulated differentially expressed genes were enriched in AGE (advanced glycation end product)/RAGE (receptor for AGE), Toll-like receptor and apoptosis signaling pathways. Our transcriptome data revealed that feeding low protein high starch diets might promote the accumulation of AGEs in LMB, which bound to RAGE and subsequently induced PI3K/Akt signal pathway. The activation of Akt induced NF-κB translocation into the nucleus thus releasing proinflammatory factors including tumor necrosis factor-α (TNF-α) and interleukin-8. The release of these inflammatory factors concomitantly induced T cell stimulation and natural killer cells chemotactic effects through Toll-like receptor signaling pathway. Besides mediating inflammation and immune response, TNF-α signal transduction participated in mediating apoptosis through the receptor of TNF (TNF-R1) pathway by up-regulating the expression of caspase 8 and cytochrome c. In conclusion, our results demonstrated that feeding low protein and high starch diets induced hepatocytes inflammation and apoptosis in LMB through the PI3K/Akt/NF-κB signaling pathway.


Bass , Starch , Animals , Starch/metabolism , Starch/pharmacology , Bass/genetics , NF-kappa B/metabolism , NF-kappa B/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Phosphatidylinositol 3-Kinases/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-akt/pharmacology , Tumor Necrosis Factor-alpha/metabolism , Tumor Necrosis Factor-alpha/pharmacology , Diet , Liver/metabolism , Triglycerides/metabolism , Inflammation , Apoptosis , Gene Expression Profiling
17.
J Phys Chem B ; 126(20): 3758-3767, 2022 05 26.
Article En | MEDLINE | ID: mdl-35559687

Symmetry-breaking charge separation (SB-CS) provides a very promising option to engineer a novel light conversion scheme, while it is still a challenge to realize SB-CS in a nonpolar environment. The strength of electronic coupling plays a crucial role in determining the exciton dynamics of organic semiconductors. Herein, we describe how to mediate interchromophore coupling to achieve SB-CS in a nonpolar solvent by the use of two perylenediimide (PDI)-based trimers, 1,7-tri-PDI and 1,6-tri-PDI. Although functionalization at the N-atom decreases electronic coupling between PDI units, our strategy takes advantage of "bridge resonance", in which the frontier orbital energies are nearly degenerate with those of the covalently linked PDI units, leading to enhanced interchromophore electronic coupling. Tunable electronic coupling was realized by the judicious combination of "bridge resonance" with N-functionalization. The enhanced mixing between the S1 state and CT/CS states results in direct observation of the CT band in the steady-state UV-vis absorption and negative free energy of charge separation (ΔGCS) in both chloroform and toluene for the two trimers. Using transient absorption spectroscopy, we demonstrated that photoinduced SB-CS in a nonpolar solvent is feasible. This work highlights that the use of "bridge resonance" is an effective way to control exciton dynamics of organic semiconductors.


Imides , Perylene , Imides/chemistry , Perylene/analogs & derivatives , Perylene/chemistry , Solvents , Spectrum Analysis
19.
Opt Lett ; 47(2): 409-412, 2022 Jan 15.
Article En | MEDLINE | ID: mdl-35030618

Coded aperture correlation holography (COACH) needs the point spread function (PSF) for image reconstruction. Utilizing a pinhole to generate a point light source is the most frequently adopted method for measuring PSF, which, however, has significant issues to resolve. One of the problems is that the resolution of the reconstructed result is limited by the cutoff frequency of the pinhole. The other is that the far-field PSF is undetectable because the amount of light illuminance decreases with the distance. In this work, we present a method for recording the PSF based on wavefront modulation. By modulating a plane wave with both the carrier spherical wave and the coded phase mask, we obtain a virtual point spread function (VPSF) that is used for image reconstruction. It is shown that the resolution of reconstructed results is not limited by the pinhole. We experimentally demonstrate high-resolution reconstruction by the VPSF.

20.
Nat Mater ; 21(2): 210-216, 2022 02.
Article En | MEDLINE | ID: mdl-34764429

X-ray detection, which plays an important role in medical and industrial fields, usually relies on inorganic scintillators to convert X-rays to visible photons; although several high-quantum-yield fluorescent molecules have been tested as scintillators, they are generally less efficient. High-energy radiation can ionize molecules and create secondary electrons and ions. As a result, a high fraction of triplet states is generated, which act as scintillation loss channels. Here we found that X-ray-induced triplet excitons can be exploited for emission through very rapid, thermally activated up-conversion. We report scintillators based on three thermally activated delayed fluorescence molecules with different emission bands, which showed significantly higher efficiency than conventional anthracene-based scintillators. X-ray imaging with 16.6 line pairs mm-1 resolution was also demonstrated. These results highlight the importance of efficient and prompt harvesting of triplet excitons for efficient X-ray scintillation and radiation detection.


Electrons , Photons , Fluorescence , X-Rays
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