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.
Arranging ionic liquids (ILs) with long‐range order can not only enhance their performance in a desired application, but can also help elucidate the vital between structure and properties. However, ...this is still a challenge and no example has been reported to date. Herein, we report a feasible strategy to achieve a crystalline IL via coordination self‐assembly based reticular chemistry. IL1MOF, was prepared by designing an IL bridging ligand and then connecting them with metal clusters. IL1MOF has a unique structure, where the IL ligands are arranged on a long‐range ordered framework but have a labile ionic center. This structure enables IL1MOF to break through the typical limitation where the solid ILs have lower proton conductivity than their counterpart bulk ILs. IL1MOF shows 2–4 orders of magnitude higher proton conductivity than its counterpart IL monomer across a wide temperature range. Moreover, by confining the IL within ultramicropores (<1 nm), IL1MOF suppresses the liquid–solid phase transition temperatures to lower than −150 °C, allowing it to function with high conductivity in a subzero temperature range.
A reticular chemistry based strategy opens a facile toolbox for designing liquid molecules with long‐rang‐ordered framework of MOF. IL1MOF is the first crystalline ionic liquid (IL) combining a balance of good mechanical properties and high conductivity. It expands the use of IL electrolytes to an low temperature region.
Maslinic acid is a pentacyclic triterpenoid that is distributed in the peel of olives. Previous studies found that maslinic acid inhibited inflammatory response and antioxidant effects. We ...investigated whether maslinic acid ameliorates nonalcoholic fatty liver disease in mice with high‐fat‐diet (HFD)‐induced obesity and evaluated the regulation of lipogenesis in hepatocytes. Male C57BL/6 mice fed a normal diet or HFD (60% fat, w/w) were tested for 16 wk. After the fourth week, mice were injected intraperitoneally with maslinic acid for 12 wk. In another experiment, HepG2 cells were treated with oleic acid to induce lipid accumulation or maslinic acid to evaluate lipogenesis. Maslinic acid significantly reduced body weight compared with HFD‐fed mice. Maslinic acid reduced liver weight and liver lipid accumulation and improved hepatocyte steatosis. Furthermore, serum glucose, leptin, and free fatty acid concentrations significantly reduced, but the serum adiponectin concentration was higher, in the maslinic acid group than in the HFD group. In liver tissue, maslinic acid suppressed transcription factors involved in lipogenesis and increased adipose triglyceride lipase. In vitro, maslinic acid decreased lipogenesis by activating AMPK. These findings suggest that maslinic acid acts against hepatic steatosis by regulating enzyme activity involved in lipogenesis, lipolysis, and fatty acid oxidation in the liver.—Liou, C.‐J., Dai, Y.‐W., Wang, C.‐L., Fang, L.‐W., Huang, W.‐C. Maslinic acid protects against obesity‐induced nonalcoholic fatty liver disease in mice through regulation of the Sirt1/AMPK signaling pathway. FASEB J. 33, 11791‐11803 (2019). www.fasebj.org
Berberine (BBR) has been confirmed to have multiple bioactivities in clinic, such as cholesterol-lowering, anti-diabetes, cardiovascular protection and anti- inflammation. However, BBR's plasma level ...is very low; it cannot explain its pharmacological effects in patients. We consider that the in vivo distribution of BBR as well as of its bioactive metabolites might provide part of the explanation for this question. In this study, liquid chromatography coupled to ion trap time-of-flight mass spectrometry (LC/MS(n)-IT-TOF) as well as liquid chromatography that coupled with tandem mass spectrometry (LC-MS/MS) was used for the study of tissue distribution and pharmacokinetics of BBR in rats after oral administration (200 mg/kg). The results indicated that BBR was quickly distributed in the liver, kidneys, muscle, lungs, brain, heart, pancreas and fat in a descending order of its amount. The pharmacokinetic profile indicated that BBR's level in most of studied tissues was higher (or much higher) than that in plasma 4 h after administration. BBR remained relatively stable in the tissues like liver, heart, brain, muscle, pancreas etc. Organ distribution of BBR's metabolites was also investigated paralleled with that of BBR. Thalifendine (M1), berberrubine (M2) and jatrorrhizine (M4), which the metabolites with moderate bioactivity, were easily detected in organs like the liver and kidney. For instance, M1, M2 and M4 were the major metabolites in the liver, among which the percentage of M2 was up to 65.1%; the level of AUC (0-t) (area under the concentration-time curve) for BBR or the metabolites in the liver was 10-fold or 30-fold higher than that in plasma, respectively. In summary, the organ concentration of BBR (as well as its bioactive metabolites) was higher than its concentration in the blood after oral administration. It might explain BBR's pharmacological effects on human diseases in clinic.
UCA1 is a long non-coding RNA which was found overexpressed in various human cancers including gastric cancer (GC). It is identified that UCA1 promotes GC cells proliferation, migration and invasion, ...however, the role of UCA1 during the processes of immune escape is still not unclear.
We collected 40 paired GC and non-tumor tissue samples. The level of UCA1 in GC and control tissue samples were determined by in situ hybridization and qRT-PCR. Cell viability was determined by MTT assay. GC cells' migration capacities were examined by transwell assay. To understand the roles of UCA1 during immune escape, wildtype or UCA1 KO GC cells co-cultured with peripheral blood mononuclear cells or cytokine-induced killer cells in vitro. Mouse model was used to examine the function of UCA1 in vivo.
UCA1 promoted GC cells proliferation and migration, and inhibit apoptosis. UCA1 repressed miR-26a/b, miR-193a and miR-214 expression through direct interaction and then up-regulated the expression of PDL1. UCA1-KO GC cells could induce a higher IFNγ expression when co-cultured with peripheral blood mononuclear cells (PBMCs), and have a lower survival rate when co-cultured with cytokine-induced killer (CIK) cells in vitro. UCA1-KO GC cells formed smaller tumors, had higher miR-26a, -26b, -193a and - 214 level, reduced cell proliferation and increased apoptosis in xenograft mouse model.
UCA1 overexpression protected PDL1 expression from the repression of miRNAs and contributed to the GC cells immune escape. UCA1 could serve as a potential novel therapeutic target for GC treatment.
Metal–organic frameworks (MOFs), a new class of porous crystalline materials, have attracted great interest as a promising candidate for sustainable energy and environmental remediation. In this ...study, ZIF-8, a versatile MOF based on imidazolate ligands, was selected as a photocatalyst to decompose methylene blue (MB) under UV light irradiation. The influence factors, kinetics, and mechanism of photocatalytic MB degradation and stability of ZIF-8, were also studied. The results revealed that the ZIF-8 photocatalyst exhibited efficiently photocatalytic activity for MB degradation under UV irradiation, which was confirmed through the detection of hydroxyl radicals (˙OH) by a fluorescence method. The MB degradation over the ZIF-8 photocatalyst followed a pseudo-first-order kinetics model. ZIF-8 worked effectively over a wide pH range from 4.0 to 12.0, and showed both high adsorption capacity and degradation efficiency for MB in a strong alkaline environment. The enhanced efficiency in a strong alkaline environment resulted from the higher charged ZIF-8 (pH > pH
pzc
) and the elevated yield of ˙OH facilitated by increased OH
−
concentration. The possible pathway of photocatalytic degradation of MB in ZIF-8 was proposed. The results indicated that ZIF-8 can be used as a highly efficient photocatalyst to decompose organic pollutants.
Near‐infrared organic light‐emitting diodes (NIR OLEDs) enable many unique applications ranging from night‐vision displays and photodynamic therapies. However, the development of efficient NIR OLEDs ...with a low efficiency roll‐off is still challenging. Here, a series of new heteroleptic Pt(II) complexes (1–4) flanked by both pyridyl pyrimidinate and functional azolate chelates are synthesized. The reduced ππ* energy gap of the pyridyl pyrimidinate chelate, and strong intermolecular interaction and high crystallinity in vacuum‐deposited thin films engender strong intermolecular charge transfer transition including metal–metal‐to‐ligand charge transfer; thereby, exhibiting efficient photoluminescence within 776–832 nm and short radiative lifetimes of 0.52–0.79 µs. Consequently, nondoped NIR‐emitting OLEDs based on these Pt(II) complexes are fabricated, to which Pt(II) complexes 2 and 4 give record high maximum external quantum efficiency of 10.61% at 794 nm and 9.58% at 803 nm, respectively. Moreover, low efficiency roll‐off is also observed, among which the device efficiencies of 2 and 4 are at least four times higher than that of the best NIR‐emitting OLEDs recorded at current density of 100 mA cm−2.
Nondoped near‐infrared organic light‐emitting diodes based on pyrimidinate‐pyrazolate Pt(II) metal complexes 2 and 4 are fabricated, yielding a record high maximum external quantum efficiency of 10.61% at 794 nm and 9.58% at 803 nm, respectively.
Both human embryonic stem cell‐derived cardiomyocytes (ESC‐CMs) and human induced pluripotent stem cell‐derived CMs (iPSC‐CMs) can serve as unlimited cell sources for cardiac regenerative therapy. ...However, the functional equivalency between human ESC‐CMs and iPSC‐CMs for cardiac regenerative therapy has not been demonstrated. Here, we performed a head‐to‐head comparison of ESC‐CMs and iPSC‐CMs in their ability to restore cardiac function in a rat myocardial infarction (MI) model as well as their exosomal secretome. Human ESCs and iPSCs were differentiated into CMs using small molecule inhibitors. Fluorescence‐activated cell sorting analysis confirmed ∼85% and ∼83% of CMs differentiated from ESCs and iPSCs, respectively, were positive for cardiac troponin T. At a single‐cell level, both cell types displayed similar calcium handling and electrophysiological properties, with gene expression comparable with the human fetal heart marked by striated sarcomeres. Sub‐acute transplantation of ESC‐CMs and iPSC‐CMs into nude rats post‐MI improved cardiac function, which was associated with increased expression of angiogenic genes in vitro following hypoxia. Profiling of exosomal microRNAs (miRs) and long non‐coding RNAs (lncRNAs) revealed that both groups contain an identical repertoire of miRs and lncRNAs, including some that are known to be cardioprotective. We demonstrate that both ESC‐CMs and iPSC‐CMs can facilitate comparable cardiac repair. This is advantageous because, unlike allogeneic ESC‐CMs used in therapy, autologous iPSC‐CMs could potentially avoid immune rejection when used for cardiac cell transplantation in the future. Stem Cells 2017;35:2138–2149
Both human embryonic stem cell‐derived cardiomyocytes (ESC‐CMs) and human induced pluripotent stem cell‐derived cardiomyocytes (iPSC‐CMs) facilitate comparable functional recovery following transplantation into infarcted hearts. Exosomal profiling revealed highly similar microRNA and long non‐coding RNA contents between exosomes from ESC‐CMs and iPSC‐CMs and may represent an alternative to direct cell therapy in the future.
Electroredox of organics provides a promising and green approach to producing value‐added chemicals. However, it remains a grand challenge to achieve high selectivity of desired products ...simultaneously at two electrodes, especially for non‐isoelectronic transfer reactions. Here a porous heterostructure of Mo2C@Co‐NC is successfully fabricated, where subnanometre β‐Mo2C clusters (<1 nm, ≈10 wt%) are confined inside porous Co, N‐doped carbon using metalorganic frameworks. It is found that Co species not only promote the formation of β‐Mo2C but also can prevent it from oxidation by constructing the heterojunctions. As noted, the heterostructure achieves >96% yield and 92% Faradaic efficiency (FE) for aldehydes in anodic alcohol oxidation, as well as >99.9% yield and 96% FE for amines in cathodal nitrocompounds reduction in 1.0 M KOH. Precise control of the reaction kinetics of two half‐reactions by the electronic interaction between β‐Mo2C and Co is a crucial adjective. Density functional theory (DFT) gives in‐depth mechanistic insight into the high aldehyde selectivity. The work guides authors to reveal the electrooxidation nature of Mo2C at a subnanometer level. It is anticipated that the strategy will provide new insights into the design of highly effective bifunctional electrocatalysts for the coproduction of more complex fine chemicals.
A porous heterostructure of Mo2C@Co‐NC is successfully fabricated with a high loading of surface Mo2C species templated by MOFs. The porous Co‐NC can effectively prompt the formation of β‐Mo2C to fabricate the heterojunction and keep the adjacent β‐Mo2C from deactivation. The heterostructure achieves high yield and Faradaic efficiency of desired products from two non‐isoelectronic transfer reactions at two electrodes.
Thiacalix4arenes as a family of promising ligands have been widely used to construct polynuclear metal clusters, but scarcely employed in silver nanoclusters. Herein, an anion-templated Ag
...nanocluster (SD/Ag88a) built from p-tert-butylthiacalix4arene (H
TC4A) is reported. Single-crystal X-ray diffraction reveals that C
-symmetric SD/Ag88a resembles a metal-organic super calix comprised of eight TC4A
as walls and 88 silver atoms as base, which can be deconstructed to eight CrO
@Ag
(TC4A)(EtS)
(OAc) secondary building units arranged in an annulus encircling a CrO
in the center. Local and global anion template effects from chromates are individually manifested in SD/Ag88a. The solution stability and hierarchical assembly mechanism of SD/Ag88a are studied by using electrospray mass spectrometry. The Ag
nanocluster represents the highest nuclearity metal cluster capped by TC4A
. This work not only exemplify the specific macrocyclic effects of TC4A
in the construction of silver nanocluster but also realize the shape heredity of TC4A
to overall silver super calix.
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