Flexible molecular crystals for optoelectronic applications.

The cornerstones of the advancement of flexible optoelectronics are the design, preparation, and utilization of novel materials with favorable mechanical and advanced optoelectronic properties. Molecular crystalline materials have emerged as a class of underexplored yet promising materials due to the reduced grain boundaries and defects anticipated to provide enhanced photoelectric characteristics. An inherent drawback that has precluded wider implementation of molecular crystals thus far, however, has been their brittleness, which renders them incapable of ensuring mechanical compliance required for even simple elastic or plastic deformation of the device. It is perplexing that despite a plethora of reports that have in the meantime become available underpinning the flexibility of molecular crystals, the "discovery" of elastically or plastically deformable crystals remains limited to cases of serendipitous and laborious trial-and-error approaches, a situation that calls for a systematic and thorough assessment of these properties and their correlation with the structure. This review provides a comprehensive and concise overview of the current understanding of the origins of crystal flexibility, the working mechanisms of deformations such as plastic and elastic bending behaviors, and insights into the examples of flexible molecular crystals, specifically concerning photoelectronic changes that occur in deformed crystals. We hope this summary will provide a reference for future experimental and computational efforts with flexible molecular crystals aimed towards improving their mechanical behavior and optoelectronic properties, ultimately intending to advance the flexible optoelectronic technology.

Tofacitinib for the treatment of immune-related adverse events in cancer immunotherapy: a multi-center observational study.

BACKGROUND: Treatment strategy against immune-related adverse events (irAEs) induced by immune checkpoint inhibitors (ICIs) frequently requires other immunosuppressive agents. Tofacitinib is a rapidly acting JAK-STAT inhibitor with proven efficacy in multiple autoimmune diseases. We aimed to evaluate the efficacy and safety of tofacitinib in the management of irAEs in cancer patients. METHODS: Cancer patients who received ICIs and were treated with tofacitinib for the management of irAEs at 6 institutions were retrospectively included in this study. Demographic and clinical characteristics were obtained from electronic medical records. Longitudinal assessment of cardiac troponin T (cTnT) with clinical assessment was utilized to evaluate the benefit of tofacitinib treatment in patients with ICI myocarditis. Overall survival (OS) was also assessed. RESULTS: Fifty-three patients were included in this study. The median time from irAE onset to tofacitinib therapy was 17 (range, 2-186) days and the median duration of tofacitinib treatment was 52.5 (range, 3-277) days. Enrolled patients were subdivided into 3 groups based on clinical severity and steroid responsiveness including 11 life-threatening cases, 30 steroid-resistant cases, and 12 cases with steroid taper failure. Clinical remission rate in each group was 54.5%, 96.7%, and 100%, respectively (P < 0.01). Tofacitinib was well-tolerated with 4 patients (7.5%) developing infectious events. From the ICI initiation, the overall median OS was 16.1 (95% CI 7.8-26.9) months. CONCLUSION: Tofacitinib showed promising clinical efficacy in patients experiencing irAEs, particularly in patients who failed to respond to steroids or experienced relapse during steroid tapering. Moreover, and most importantly, tofacitinib exhibited a favorable safety profile in cancer patients developing irAEs in terms of both toxicity and anti-tumor activity. Future prospective studies are warranted.

SARS-CoV-2 NSP2 as a Potential Delivery Vehicle for Proteins.

The development of biomolecule delivery systems is essential for the treatment of various diseases such as cancer, immunological diseases, and metabolic disorders. For the first time, we found that SARS-CoV-2-encoded nonstructural protein 2 (NSP2) can be secreted from the cells, where it is synthesized. Brefeldin A and H89, inhibitors of ER/Golgi secretion pathways, did not inhibit NSP2 secretion. NSP2 is likely secreted via an unconventional secretory pathway. Moreover, both secreted and purified NSP2 proteins were able to traverse the plasma membrane barrier and enter both immortalized human umbilical vein endothelial cells and tumor cell lines. After entry, the NSP2 protein was localized in only the cytoplasm. Cytochalasin D, a potent inhibitor of actin polymerization, inhibited the entry of NSP2. NSP2 can carry other molecules into cells. Burkholderia lethal factor 1, a monomeric toxin from the intracellular pathogen Burkholderia pseudomallei, has demonstrated antitumor activity by targeting host eukaryotic initiation translation factor 4A. An NSP2-BLF1 fusion protein was translocated across the cellular membranes of Huh7 cells and mediated cell killing. By using different approaches, including protein purification, chemical inhibition, and cell imaging, we confirm that NSP2 is able to deliver heterologous proteins into cells. NSP2 can act as a potential delivery vehicle for proteins.

The prognostic value of global myocardium strain by CMR-feature tracking in immune checkpoint inhibitor-associated myocarditis.

OBJECTIVES: Immune checkpoint inhibitor (ICI)-associated myocarditis is a potentially fatal complication. Sparse published researches evaluated the prognostic value of cardiovascular magnetic resonance feature tracking (CMR-FT) for ICI-associated myocarditis. METHODS: In the single-center retrospective study, 52 patients with ICI-associated myocarditis and CMR were included from August 2018 to July 2021. The ICI-associated myocarditis was diagnosed by using the clinical criteria of the European Society of Cardiology guidelines. Major adverse cardiovascular events (MACE) were comprised of cardiovascular death, cardiogenic shock, cardiac arrest, and complete heart block. RESULTS: During a median follow-up of 171 days, 14 (27%) patients developed MACE. For patients with MACE, the global circumferential strain (GCS), global radial strain (GRS), global longitudinal strain (GLS), and left ventricular ejection fraction (LVEF) were significantly worse and native T1 values and late gadolinium enhancement (LGE) extent were significantly increased, compared with patients without MACE (p < 0.05). The GLS remained the independent factor associated with a higher risk of MACE (hazard ratio (HR): 2.115; 95% confidence interval (CI): 1.379-3.246; p = 0.001) when adjusting for LVEF, LGE extent, age, sex, body mass index, steroid treatment, and prior cardiotoxic chemotherapy or radiation. After adjustment for LVEF, the GLS remained the independent risk factor associated with a higher rate of MACE among patients with a preserved LVEF (HR: 1.358; 95% CI: 1.007-1.830; p = 0.045). CONCLUSIONS: GLS could provide independent prognostic value over GCS, GRS, traditional CMR features, and clinical features in patients with ICI-associated myocarditis. KEY POINTS: • The global circumferential strain (GCS), global radial strain (GRS), and global longitudinal strain (GLS) by cardiovascular magnetic resonance feature tracking were significantly impaired in patients with an immune checkpoint inhibitor (ICI)-associated myocarditis. • GLS was still significantly impaired in patients with preserved left ventricular ejection fraction. • The worse GLS was an independent risk factor over GCS, GRS, traditional CMR features, and clinical features for predicting major adverse cardiovascular events in patients with ICI-associated myocarditis.

Heteroatomic Conjugated Polymers and the Spectral Tuning of Electroluminescence via a Supramolecular Coordination Strategy.

The unique electronic structures of heteroatomic conjugated polymers (HCPs) offer an attractive platform to tune optoelectronic properties via a supramolecular coordination strategy. This study reports on an sp2 nitrogen heteroatom containing fluorene-based copolymer namely poly(9,9-dioctylfluorene-co-9,9-dioctyldiazafluoren-2,7-yl) (PF8-co-DAF8), with ≈20% DAF8 units. Tuning the optoelectronic properties of PF8-co-DAF8 via supramolecular coordination with a Lewis acid (B(C6 F5 )3 or AlCl3 ) is explored. Formation of either the PF8-co-DAF8-B(C6 F5 )3 or PF8-co-DAF8-AlCl3 adducts reduces the optical gap and causes an attendant redshift of the photoluminescence spectra. Controlling the degree and strength of the coordination allows the emission color to be tuned from blue through to green and yellow. This strategy is successfully implemented for polymer light-emitting diodes, confirming the large degree of spectral tuning whilst maintaining good device performance. Maximum luminous efficiencies, η ≈ 1.55 cd A-1 @ 2120 cd m-2 , 1.32 cd A-1 @ 1424 cd m-2 , and 2.56 cd A-1 @ 910 cd m-2 are, respectively, recorded for the blue-emitting diodes with Commission Internationale de L'Eclairage (CIE) (x, y) coordinates = (0.16, 0.16), the white-emitting diodes with CIE (x, y) = (0.28, 0.38) and the green-emitting diodes with CIE (x, y) = (0.33, 0.52). The results highlight the versatility of the supramolecular coordination strategy in modifying the electronic structure of HCPs.

Hydrogen-bonded supramolecular conjugated polymer nanoparticles for white light-emitting devices.

Supramolecular polyfluorenol enable assembly into conjugated polymer nanoparticles (CPNs). Poly{9-[4-(octyloxy)phenyl]fluoren-9-ol-2,7-diyl} (PPFOH)-based supramolecular nanoparticles are prepared via reprecipitation. PPFOH nanoparticles with diameters ranging from 40 to 200 nm are obtained by adding different amounts of water into DMF solution. Size-dependent luminescence is observed in PPFOH-based hydrogen-bonded nanoparticles that is different from that of poly(9,9-dioctylfluorenes). Finally, white light-emitting devices using CPNs with a size of 80 nm exhibit white emission with the CIE coordinates (0.31, 0.34). Amphiphilic conjugated polymer nanoparticles are potential organic nano-inks for the fabrication of organic devices in printed electronics.

Ultraviolet Organic Laser from Rhombus Microcrystal: Benefits of Single-Molecule Emission from Twisted Structure.

Light-emitting molecular crystals with efficient emission behavior are crucial for fabricating low-threshold ultraviolet organic lasers. Herein, we demonstrated a rhombus microcrystal from a fluorene-based conjugated molecule (CL-1) with robust emission behavior for an ultraviolet organic laser. Due to the synergistic effect of twisted intramolecular conformation and weak π-interaction, the CL-1 single crystal showed an extremely high photoluminescence quantum yield (PLQY) of ∼82%, due to their single-molecule excitonic behavior. Considering the diverse noncovalent interactions, CL-1 molecules easily self-assembled into the rhombus microcrystals. Finally, a low-threshold ultraviolet organic laser was fabricated with a sharp emission at 379 nm, attributed to the 0-1 vibration band of a single CL-1 molecule, also further confirming the single twisted-molecule emission in crystal states. Precisely controlling the intramolecular twisted structure and intermolecular interaction of organic conjugated molecules is a precondition to obtain robust ultraviolet emission for optoelectronic applications.

A Holistic Review of C = C Crosslinkable Conjugated Molecules in Solution-Processed Organic Electronics: Insights into Stability, Processibility, and Mechanical Properties.

Solution-processable organic conjugated molecules (OCMs) consist of a series of aromatic units linked by σ-bonds, which present a relatively freedom intramolecular motion and intermolecular re-arrangement under external stimulation. The cross-linked strategy provides an effective platform to obtain OCMs network, which allows for outstanding optoelectronic, excellent physicochemical properties, and substantial improvement in device fabrication. An unsaturated double carbon-carbon bond (C = C) is universal segment to construct crosslinkable OCMs. In this review, the authors will set C = C cross-linkable units as an example to summarize the development of cross-linkable OCMs for solution-processable optoelectronic applications. First, this review provides a comprehensive overview of the distinctive chemical, physical, and optoelectronic properties arising from the cross-linking strategies employed in OCMs. Second, the methods for probing the C = C cross-linking reaction are also emphasized based on the perturbations of chemical structure and physicochemical property. Third, a series of model C = C cross-linkable units, including styrene, trifluoroethylene, and unsaturated acid ester, are further discussed to design and prepare novel OCMs. Furthermore, a concise overview of the optoelectronic applications associated with this approach is presented, including light-emitting diodes (LEDs), solar cells (SCs), and field-effect transistors (FETs). Lastly, the authors offer a concluding perspective and outlook for the improvement of OCMs and their optoelectronic application via the cross-linking strategy.

Coplanar Conformational Structure of π-Conjugated Polymers for Optoelectronic Applications.

Hierarchical structure of conjugated polymers is critical to dominating their optoelectronic properties and applications. Compared to nonplanar conformational segments, coplanar conformational segments of conjugated polymers (CPs) demonstrate favorable properties for applications as a semiconductor. Herein, recent developments in the coplanar conformational structure of CPs for optoelectronic devices are summarized. First, this review comprehensively summarizes the unique properties of planar conformational structures. Second, the characteristics of the coplanar conformation in terms of optoelectrical properties and other polymer physics characteristics are emphasized. Five primary characterization methods for investigating the complanate backbone structures are illustrated, providing a systematical toolbox for studying this specific conformation. Third, internal and external conditions for inducing the coplanar conformational structure are presented, offering guidelines for designing this conformation. Fourth, the optoelectronic applications of this segment, such as light-emitting diodes, solar cells, and field-effect transistors, are briefly summarized. Finally, a conclusion and outlook for the coplanar conformational segment regarding molecular design and applications are provided.

MCOLN1/TRPML1 in the lysosome: a promising target for autophagy modulation in diverse diseases.

MCOLN1/TRPML1 is a nonselective cationic channel specifically localized to the late endosome and lysosome. With its property of mediating the release of several divalent cations such as Ca2+, Zn2+ and Fe2+ from the lysosome to the cytosol, MCOLN1 plays a pivotal role in regulating a variety of cellular events including endocytosis, exocytosis, lysosomal biogenesis, lysosome reformation, and especially in Macroautophagy/autophagy. Autophagy is a highly conserved catabolic process that maintains cytoplasmic integrity by removing superfluous proteins and damaged organelles. Acting as the terminal compartments, lysosomes are crucial for the completion of the autophagy process. This review delves into the emerging role of MCOLN1 in controlling the autophagic process by regulating lysosomal ionic homeostasis, thereby governing the fundamental functions of lysosomes. Furthermore, this review summarizes the physiological relevance as well as molecular mechanisms through which MCOLN1 orchestrates autophagy, consequently influencing mitochondria turnover, cell apoptosis and migration. In addition, we have illustrated the implications of MCOLN1-regulated autophagy in the pathological process of cancer and myocardial ischemia-reperfusion (I/R) injury. In summary, given the involvement of MCOLN1-mediated autophagy in the pathogenesis of cancer and myocardial I/R injury, targeting MCOLN1 May provide clues for developing new therapeutic strategies for the treatment of these diseases. Exploring the regulation of MCOLN1-mediated autophagy in diverse diseases contexts will surely broaden our understanding of this pathway and offer its potential as a promising drug target.Abbreviation: CCCP:carbonyl cyanide3-chlorophenylhydrazone; CQ:chloroquine; HCQ: hydroxychloroquine;I/R: ischemia-reperfusion; MAP1LC3/LC3:microtubule associated protein 1 light chain 3; MCOLN1/TRPML1:mucolipin TRP cation channel 1; MLIV: mucolipidosis type IV; MTORC1:MTOR complex 1; ROS: reactive oxygenspecies; SQSTM1/p62: sequestosome 1.

Clinical Outcomes of Severe Rhinosinusitis Complicated with Cavernous Sinus Syndrome.

Background: Various diseases involving the cavernous sinus can cause a condition called cavernous sinus syndrome (CSS), which is characterized by ophthalmoplegia or sensory deficits over the face resulting from the compression effect of internal structure. While tumor compression is the most reported cause of CSS, statistical data on CSS caused by infections are limited. Its risk factors, treatment methods, and clinical outcomes are not well-documented. Methods: In this retrospective study, we reviewed the data of patients admitted to a tertiary medical center from 2015 to 2022 with a diagnosis of acute and chronic sinusitis and at least one diagnostic code for CSS symptoms. We manually reviewed whether patients were involved in two or more of the following cranial nerves (CN): CN III, CN IV, CN V, or CN VI, or at least one of these nerves with a neuroimaging-confirmed lesion in the cavernous sinus. Results: Nine patients were diagnosed with rhinosinusitis-related CSS. The most common comorbidity was type 2 diabetes, and the most common clinical manifestations were diplopia and blurred vision. The sphenoid sinus was the most affected sinus. One patient expired due to a severe brain abscess infection without surgery. The remaining patients underwent functional endoscopic sinus surgery, and 50% of the pathology reports indicated fungal infections. Staphylococcus spp. was the most cultured bacteria, and Amoxycillin/Clavulanate was the most used antibiotic. Only four patients had total recovery during the follow-up one year later. Conclusions: CSS is a rare but serious complication of rhinosinusitis. Patients with diabetes and the elderly may be at a higher risk for this complication. Even after treatment, some patients may still have neurological symptoms.

Intrinsically stretchable fully π-conjugated polymer film via fluid conjugated molecular external-plasticizing for flexible light-emitting diodes.

Fully π-conjugated polymers with rigid aromatic units are promising for flexible optoelectronic devices, but their inherent brittleness poses a challenge for achieving high-performance, intrinsically stretchable fully π-conjugated polymer. Here, we are establishing an external-plasticizing strategy using semiconductor fluid plasticizers (Z1 and Z2) to enhance the optoelectronic, morphological, and stretchable properties of fully π-conjugated polymer films for flexible light-emitting diodes. The synergistic effect of hierarchical structure and optoelectronic properties of Z1 in poly(9,9-di-n-octylfluorene-alt-benzothiadiazole) (F8BT) films enable excellent stretchable deformability (~25%) and good conductivity. PLEDs based on F8BT/Z1 films show stable electroluminescence and efficiency under 15% stretch and 100 cycles at 10% strain, revealing outstanding stress tolerance. This strategy is also improving the stretchable properties of polymers like poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) and poly(2-methoxy-5(2'-ethyl)hexoxy-phenylenevinylene) (Super Yellow), demonstrating its general applicability. Therefore, this strategy can provide effective guidance for designing high-performance stretchable fully π-conjugated polymers films for flexible electronic devices.

Cardiac magnetic resonance-based layer-specific strain in immune checkpoint inhibitor-associated myocarditis.

AIMS: To assess the different imaging characteristics between corticosteroid-sensitive (CS) and corticosteroid-refractory (CR) immune checkpoint inhibitor-associated myocarditis (ICIaM) with cardiac magnetic resonance (CMR) and the potential CMR parameters in the early detection of CR ICIaM. METHODS AND RESULTS: Thirty-five patients diagnosed with ICIaM and 30 age and gender-matched cancer patients without a history of ICI treatment were enrolled. CMR with contrast was performed within 2 days of clinical suspicion. Left ventricular ejection fraction (LVEF) and late gadolinium enhancement (LGE) were assessed by CMR. LV sub-endocardial (GLSendo) and sub-epicardial (GLSepi) global longitudinal strains were quantified by offline feature tracking analysis. CS and CR ICIaM were defined based on the trend of Troponin I and clinical course during corticosteroid treatment. All 35 patients presented with non-fulminant symptoms upon initial assessment. Twenty patients (57.14%) were sensitive, and 15 (42.86%) were refractory to corticosteroids. Compared with controls, 22 patients (62.86%) with ICIaM developed LGE. LVEF decreased in CR ICIaM compared with the CS group and controls. GLSendo (-14.61 ± 2.67 vs. -18.50 ± 2.53, P < 0.001) and GLSepi (-14.75 ± 2.53 vs. -16.68 ± 2.05, P < 0.001) significantly increased in patients with CR ICIaM compared with the CS ICIaM. In patients with CS ICIaM, although GLSepi (-16.68 ± 2.05 vs. -19.31 ± 1.80, P < 0.001) was impaired compared with the controls, GLSendo was preserved. There was no difference in CMR parameters between LGE-positive and negative groups. LVEF, GLSendo, and GLSepi were predictors of CR ICIaM. When LVEF, GLSendo, and GLSepi were included in multivariate analysis, only GLSendo remained an independent predictor of CR ICIaM (OR: 2.170, 95% CI: 1.189-3.962, P = 0.012). A GLSendo of ≥-17.10% (sensitivity, 86.7%; specificity, 80.0%; AUC, 0.860; P < 0.001) could predict CR ICIaM in the ICIaM cohort. Kaplan-Meier analysis showed that in patients with impaired GLSendo of ≥-17.10%, cardiovascular adverse events (CAEs) occurred much earlier than in patients with preserved GLSendo of <-17.10% (Log-rank test P = 0.017). CONCLUSIONS: CR and CS ICIaM demonstrated different functional and morphological characteristics in different myocardial layers. An impaired GLSendo could be a helpful parameter in early identifying corticosteroid-refractory individuals in the ICIaM population.

C-H-activated Csp2-Csp3 diastereoselective gridization enables ultraviolet-emitting stereo-molecular nanohydrocarbons with mulitple H···H interactions.

Gridization is an emerging molecular integration technology that enables the creation of multifunctional organic semiconductors through precise linkages. While Friedel-Crafts gridization of fluorenols is potent, direct linkage among fluorene molecules poses a challenge. Herein, we report an achiral Pd-PPh3-cataylized diastereoselective (>99:1 d.r.) gridization based on the C-H-activation of fluorene to give dimeric and trimeric windmill-type nanogrids (DWGs and TWGs). These non-conjugated stereo-nanogrids showcase intramolecular multiple H…H interactions with a low field shift to 8.51 ppm and circularly polarized luminescence with high luminescent dissymmetry factors (|gPL | = 0.012). Significantly, the nondoped organic light-emitting diodes (OLEDs) utilizing cis-trans-TWG1 emitter present an ultraviolet electroluminescent peak at ~386 nm (CIE: 0.17, 0.04) with a maximum external quantum efficiency of 4.17%, marking the highest record among nondoped ultraviolet OLEDs based on hydrocarbon compounds and the pioneering ultraviolet OLEDs based on macrocycles. These nanohydrocarbon offer potential nanoscafflolds for ultraviolet light-emitting optoelectronic applications.

Triphenylamine Spirofunctionalized Light-Emitting Conjugated Polymer with an Ultradeep-Blue Narrowband Emission for Large-Area Printed Display.

Emerging printed large-area polymer light-emitting diodes (PLEDs) are essential for manufacturing flat-panel displays and solid lighting devices. However, it is challenging to obtain large-area and stable ultradeep-blue PLEDs because of the lack of light-emitting conjugated polymers (LCPs) with robust deep-blue emissions, excellent morphological stabilities, and high charging abilities. Here, a novel unsymmetrically substituted polydiarylfluorene (POPSAF) is obtained with stable narrowband emission for large-area printed displays via triphenylamine (TPA) spirofunctionalization of LCPs. POPSAF films show narrowband and stable ultradeep-blue emission with a full width at half maximum (FWHM) of 36 nm, associated with their intrachain excitonic behavior without obvious polaron formation. Compared to controlled poly[4-(octyloxy)-9,9-diphenylfluoren-2,7-diyl]-co-[5-(octyloxy)-9,9-diphenylfluoren-2,7-diyl] (PODPF), excellent charge transport is observed in the POPSAF films because of the intrinsic hole transport ability of the TPA units. Large-area PLEDs are fabricated via blade-coating with an emission area of 9 cm2, which exhibit uniform ultradeep-blue emission with an FWHM of 36 nm and corresponding Commission internationale de l'éclairage (CIE) coordinates of (0.155, 0.072). These findings are attributed to the synergistic effects of robust emission, stable morphology, and printing capacity. Finally, preliminary printed passive matrix (PM) PLED displays with 20 × 20 pixels monochromes are fabricated, confirmed the effectiveness of spirofunctionalization in optoelectronics.

Elastic-Plastic Fully π-Conjugated Polymer with Excellent Energy Dissipation Capacity for Ultra-Deep-Blue Flexible Polymer Light-Emitting Diodes with CIEy = 0.04.

Emerging intrinsically flexible fully π-conjugated polymers (FπCPs) are a promising functional material for flexible optoelectronics, attributed to their potential interchain interpenetration and entanglement. However, the challenge remains in obtaining elastic-plastic FπCPs with intrinsic robust optoelectronic property and excellent long-term and cycling deformation stability simultaneously for applications in deep-blue flexible polymer light-emitting diodes (PLEDs). This study, demonstrates a series of elastic-plastic FπCPs (P1-P4) with an excellent energy dissipation capacity via side-chain internal plasticization for the ultra-deep-blue flexible PLEDs. First, the freestanding P1 film exhibited a maximum fracture strain of 34.6%. More interestingly, the elastic behavior is observed with a low strain (≤10%), and the stretched film with a high deformation (>10%) attributed to plastic processing revealed the robust capacity to realize energy absorption and release. The elastic-plastic P1 film exhibits outstanding ultra-deep-blue emission, with an efficiency of 56.38%. Subsequently, efficient PLEDs are fabricated with an ultra-deep-blue emission of CIE (0.16, 0.04) and a maximum external quantum efficiency of 1.73%. Finally, stable and efficient ultra-deep-blue electroluminescence are obtained from PLEDs based on stretchable films with different strains and cycling deformations, suggesting excellent elastic-plastic behavior and deformation stability for flexible electronics.

Bottom-up synthesis of nanoscale conjugation-interrupted frameworks and their electrical properties.

Soluble covalent organic nanoframeworks up to generation 2.5 (G2.5) are synthesized with self-similar H-shaped conformations by using a bottom-up approach including iterative C-H bond functionalization. The electrical characteristics of nanoscale thin-film semiconductors of the conjugation-interrupted frameworks can be tuned by post-modification with diazonium salt.

Comparison of various niches for endothelial progenitor cell therapy on ischemic myocardial repair: coexistence of host collateralization and Akt-mediated angiogenesis produces a superior microenvironment.

OBJECTIVE: Comparative studies are lacking that show the effects of different microenvironments on the activity of engrafted stem cells after myocardial infarction (MI). Here, we analyzed the temporal and spatial variations of angiogenesis, collateralization, and the expression of Akt-related signals after MI to test whether the effects of endothelial progenitor cells (EPCs) were different. METHODS AND RESULTS: After the induction of MI, pigs were selected that did not develop a collateral coronary circulation (R0) or developed a significant collateral coronary circulation (R2). Both sets were allocated randomly to 4 groups: phosphate-buffered saline (intramyocardial injection of phosphate-buffered saline), EPC transplantation, LY294002 (intramyocardial injection of an Akt inhibitor), and EPCs plus LY294002. Infarcted porcine hearts at different time points and under different collateralized conditions exhibited a variety of vascular microenvironments. At 14 days post-MI, angiogenesis and the expression of Akt-mediated angiogenic cytokines predominated in R2 porcine hearts. When grafted into this microenvironment, EPCs induced the greatest effects in impeding the development of heart failure, preserving left ventricular function and dimensions, and inhibiting infarct expansion. LY294002 significantly reduced these effects. CONCLUSIONS: These findings suggest that the microenvironment that coexists with collateralization and Akt-mediated angiogenesis appears to be more beneficial to cardiac repair induced by EPC therapy than other niches after MI.

Supramolecular luminescence from oligofluorenol-based supramolecular polymer semiconductors.

Supramolecular luminescence stems from non-covalent exciton behaviors of active π-segments in supramolecular entities or aggregates via intermolecular forces. Herein, a π-conjugated oligofluorenol, containing self-complementary double hydrogen bonds, was synthesized using Suzuki coupling as a supramolecular semiconductor. Terfluorenol-based random supramolecular polymers were confirmed via concentration-dependent nuclear magnetic resonance (NMR) and dynamic light scattering (DLS). The photoluminescent spectra of the TFOH-1 solution exhibit a green emission band (g-band) at approximately ~520 nm with reversible features, as confirmed through titration experiments. Supramolecular luminescence of TFOH-1 thin films serves as robust evidence for the aggregates of g-band. Our results suggest that the presence of polyfluorene ketone defects is a sufficient condition, rather than a sufficient-necessary condition for the g-band. Supramolecular electroluminescence will push organic devices into the fields of supramolecular optoelectronics, spintronics, and mechatronics.

Nanocrystal Array Engineering and Optoelectronic Applications of Organic Small-Molecule Semiconductors.

Organic small-molecule semiconductor materials have attracted extensive attention because of their excellent properties. Due to the randomness of crystal orientation and growth location, however, the preparation of continuous and highly ordered organic small-molecule semiconductor nanocrystal arrays still face more challenges. Compared to organic macromolecules, organic small molecules exhibit better crystallinity, and therefore, they exhibit better semiconductor performance. The formation of organic small-molecule crystals relies heavily on weak interactions such as hydrogen bonds, van der Waals forces, and π-π interactions, which are very sensitive to external stimuli such as mechanical forces, high temperatures, and organic solvents. Therefore, nanocrystal array engineering is more flexible than that of the inorganic materials. In addition, nanocrystal array engineering is a key step towards practical application. To resolve this problem, many conventional nanocrystal array preparation methods have been developed, such as spin coating, etc. In this review, the typical and recent progress of nanocrystal array engineering are summarized. It is the typical and recent innovations that the array of nanocrystal array engineering can be patterned on the substrate through top-down, bottom-up, self-assembly, and crystallization methods, and it can also be patterned by constructing a series of microscopic structures. Finally, various multifunctional and emerging applications based on organic small-molecule semiconductor nanocrystal arrays are introduced.