The lack of structural information impeded the access of efficient luminescence for the exciplex type thermally activated delayed fluorescence (TADF). We report here the pump-probe Step-Scan Fourier ...transform infrared spectra of exciplex composed of a carbazole-based electron donor (CN-Cz2) and 1,3,5-triazine-based electron acceptor (PO-T2T) codeposited as the solid film that gives intermolecular charge transfer (CT), TADF, and record-high exciplex type cyan organic light emitting diodes (external quantum efficiency: 16%). The transient infrared spectral assignment to the CT state is unambiguous due to its distinction from the local excited state of either the donor or the acceptor chromophore. Importantly, a broad absorption band centered at ~2060 cm
was observed and assigned to a polaron-pair absorption. Time-resolved kinetics lead us to conclude that CT excited states relax to a ground-state intermediate with a time constant of ~3 µs, followed by a structural relaxation to the original CN-Cz2:PO-T2T configuration within ~14 µs.
A star-shaped 1,3,5-triazine/cyano hybrid molecule CN-T2T was designed and synthesized as a new electron acceptor for efficient exciplex-based OLED emitter by mixing with a suitable electron donor ...(Tris-PCz). The CN-T2T/Tris-PCz exciplex emission shows a high ΦPL of 0.53 and a small ΔE T‑S = −0.59 kcal/mol, affording intrinsically efficient fluorescence and highly efficient exciton up-conversion. The large energy level offsets between Tris-PCz and CN-T2T and the balanced hole and electron mobility of Tris-PCz and CN-T2T, respectively, ensuring sufficient carrier density accumulated in the interface for efficient generation of exciplex excitons. Employing a facile device structure composed as ITO/4% ReO3:Tris-PCz (60 nm)/Tris-PCz (15 nm)/Tris-PCz:CN-T2T(1:1) (25 nm)/CN-T2T (50 nm)/Liq (0.5 nm)/Al (100 nm), in which the electron–hole capture is efficient without additional carrier injection barrier from donor (or acceptor) molecule and carriers mobilities are balanced in the emitting layer, leads to a highly efficient green exciplex OLED with external quantum efficiency (EQE) of 11.9%. The obtained EQE is 18% higher than that of a comparison device using an exciplex exhibiting a comparable ΦPL (0.50), in which TCTA shows similar energy levels but higher hole mobility as compared with Tris-PCz. Our results clearly indicate the significance of mobility balance in governing the efficiency of exciplex-based OLED. Exploiting the Tris-PCz:CN-T2T exciplex as the host, we further demonstrated highly efficient yellow and red fluorescent OLEDs by doping 1 wt % Rubrene and DCJTB as emitter, achieving high EQE of 6.9 and 9.7%, respectively.
The development of high-performance near-infrared organic light-emitting diodes is hindered by strong non-radiative processes as governed by the energy gap law. Here, we show that exciton ...delocalization, which serves to decouple the exciton band from highly vibrational ladders in the S0 ground state, can bring substantial enhancements in the photoluminescence quantum yield of emitters, bypassing the energy gap law. Experimental proof is provided by the design and synthesis of a series of new Pt(ii) complexes with a delocalization length of 5–9 molecules that emit at 866–960 nm with a photoluminescence quantum yield of 5–12% in solid films. The corresponding near-infrared organic light-emitting diodes emit light with a 930 nm peak wavelength and a high external quantum efficiency up to 2.14% and a radiance of 41.6 W sr−1 m−2. Both theoretical and experimental results confirm the exciton–vibration decoupling strategy, which should be broadly applicable to other well-aligned molecular solids.Pt(ii) complexes allow the fabrication of efficient near-infrared organic light-emitting diodes that operate beyond the 900 nm region.
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have become a powerful tool for human disease modeling and therapeutic testing. However, their use remains limited by their ...immaturity and heterogeneity. To characterize the source of this heterogeneity, we applied complementary single-cell RNA-seq and bulk RNA-seq technologies over time during hiPSC cardiac differentiation and in the adult heart. Using integrated transcriptomic and splicing analysis, more than half a dozen distinct single-cell populations were observed, several of which were coincident at a single time-point, day 30 of differentiation. To dissect the role of distinct cardiac transcriptional regulators associated with each cell population, we systematically tested the effect of a gain or loss of three transcription factors (NR2F2, TBX5, and HEY2), using CRISPR genome editing and ChIP-seq, in conjunction with patch clamp, calcium imaging, and CyTOF analysis. These targets, data, and integrative genomics analysis methods provide a powerful platform for understanding in vitro cellular heterogeneity.
High-grade hemorrhoids are usually recommended to receive operational treatments. However, these traditional surgeries are associated with severe postoperative pain. A procedure for prolapse and ...hemorrhoids (PPH), a circular staple device, has been developed to improve short-term outcomes, including reducing the severity of postoperative pain. PPH, compared to conventional surgery, has been associated with the incidence of anatomical anal stenosis. The causes of stenosis after PPH are not yet clear. We first analyzed the complications of our patients with PPH, and then developed a rat model to verify the tension force of PPH using Hematoxylin-eosin, Masson's trichrome, immunohistochemistry, and immunofluorescence staining. Our clinical data showed that PPH significantly improved postoperative pain, but that it resulted in higher incidences of complications, including anal stenosis, than hemorrhoidectomy. We simulated the status of PPH and developed a rat model to verify PPH's tension force, including the scarring area and the deposition of proinflammatory factors, angiogenic factors, and fibrotic factors. The tension wound histological data showed more extensive granulation tissue and inflammatory cell infiltration and a thicker epidermis than the control group on day 12 post-operation and tension treatment. In addition to IL-1β and IL-10 cytokines on day 3 and IL-1β, IL-6, and IL-10 cytokines on day 12 post-operation in the tension group, two angiogenic factors, CD31 and VEGF-A, were found to have a more significant expression on day 7 post-operation in the tension group. The mean scar area was larger and the distribution of fibrotic proteins (collagen 1, α-SMA, CTGF, and MMP2) in the tension group was significantly broader than in the control on day 12 post-operation and tension treatment. Based on the findings of our animal model, the development of a lesser tensile force for PPH to decrease the deposition of proinflammatory factors, angiogenic factors, and fibrotic factors is urgently required.
Herein, we used isotopic formaldehyde and sodium cyanoborohydride via reductive amination to label two methyl groups on primary amine to arrange the standards (
-formaldehyde-modified) and internal ...standards (ISs,
-formaldehyde-modified) of tryptophan and its metabolites, such as serotonin (5-hydroxytryptamine) and 5-hydroxytryptophan. These derivatized reactions with a high yield are very satisfactory for manufacturing standards and ISs. This strategy will generate one or two methyl groups on amine to create different mass unit shifts with 14 vs. 16 or 28 vs. 32 in individual compounds for biomolecules with amine groups. In other words, multiples of two mass units shift are created using this derivatized method with isotopic formaldehyde. Serotonin, 5-hydroxytryptophan, and tryptophan were used as examples to demonstrate isotopic formaldehyde-generating standards and ISs.
-formaldehyde-modified serotonin, 5-hydroxytryptophan, and tryptophan are standards to construct calibration curves, and
-formaldehyde-modified analogs such as ISs spike into samples to normalize the signal of each detection. We utilized multiple reaction monitoring modes and triple quadrupole mass spectrometry to demonstrate the derivatized method suitable for these three nervous biomolecules. The derivatized method demonstrated a linearity range of the coefficient of determinations between 0.9938 to 0.9969. The limits of detection and quantification ranged from 1.39 to 15.36 ng/mL.
Diseases in articular cartilages have affected millions of people globally. Although the biochemical and cellular composition of articular cartilages is relatively simple, there is a limitation in ...the self-repair ability of the cartilage. Therefore, developing strategies for cartilage repair is very important. Here, we report on a new liquid resin preparation process of water-based polyurethane based photosensitive materials with hyaluronic acid with application of the materials for 3D printed customized cartilage scaffolds. The scaffold has high cytocompatibility and is one that closely mimics the mechanical properties of articular cartilages. It is suitable for culturing human Wharton's jelly mesenchymal stem cells (hWJMSCs) and the cells in this case showed an excellent chondrogenic differentiation capacity. We consider that the 3D printing hybrid scaffolds may have potential in customized tissue engineering and also facilitate the development of cartilage tissue engineering.
Graphene, with cracks filled with gold nanoparticles, is grown by chemical vapor deposition on a Cu substrate. The crack‐filled graphene not only exhibits superior electrical properties but also ...forms a better junction with other semiconductors. A high‐quality crack‐filled graphene/Si Schottky junction solar cell is achieved, demonstrating the highest fill factor (0.79) and best efficiency (12.3%).
Pt(II) metal complexes are known to exhibit strong solid‐state aggregation and are promising for realization of efficient emission in fabrication of organic light emitting diodes (OLED) with nondoped ...emitter layer. Four pyrimidine–pyrazolate based chelates, together with four isomeric Pt(II) metal complexes, namely: Pt(pm2z)2, Pt(tpm2z)2, Pt(pm4z)2, and Pt(tpm4z)2, are isolated and systematically investigated for their structure–property relationships for practical OLED applications. Detailed single molecular and aggregated structures are revealed by photophysical and mechanochromic measurements, grazing‐incidence X‐ray diffraction, and theoretical approaches. These results suggest that these Pt(II) emitters pack like a deck of playing cards under vacuum deposition, and their emission energy is not only affected by the single molecular designs, but notably influenced by their intermolecular packing interaction, i.e., Pt···Pt separations that are arranged in the order: Pt(tpm4z)2 > Pt(pm4z)2 > Pt(tpm2z)2 > Pt(pm2z)2. Nondoped OLED with emission ranging from green to red are prepared, to which the best performances are recorded for Pt(tpm2z)2, giving maximum external quantum efficiency (EQE) of 27.5% at 103 cd m−2, maximum luminance of 2.5 × 105 cd m−2 at 17 V, and with stable CIEx,y of (0.56, 0.44).
Nondoped organic light emitting diodes (OLED) devices with emission ranging from green to red are prepared using four Pt(II) complexes that exhibit strong solid‐state aggregation and horizontal aligned transition dipole moments, while their stacking characteristics also play a crucial role in manipulating the emission properties.
Oral submucous fibrosis (OSF) has been recognized as a potentially malignant disorder and is characterized by inflammation and the deposition of collagen. Among various regulators of fibrogenesis, ...microRNAs (miR) have received great attention but the detailed mechanisms underlying the miR-mediated modulations remain largely unknown. Here, we showed that miR-424 was aberrantly overexpressed in OSF tissues, and then we assessed its functional role in the maintenance of myofibroblast characteristics. Our results demonstrated that the suppression of miR-424 markedly reduced various myofibroblast activities (such as collagen contractility and migration ability) and downregulated the expression of fibrosis markers. Moreover, we showed that miR-424 exerted this pro-fibrosis property via direct binding to TGIF2, an endogenous repressor of the TGF-β signaling. In addition, our findings indicated that overexpression of miR-424 activated the TGF-β/Smad pathway, leading to enhanced myofibroblast activities. Altogether, our data revealed how miR-424 contributed to myofibroblast transdifferentiation, and targeting the miR-424/TGIF2 axis may be a viable direction for achieving satisfactory results from OSF treatment.
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