Perovskite light‐emitting diodes (PeLEDs) are promising technologies for advanced display and lighting source applications. Alongside tremendous efforts to improve efficiency, developing flexible ...devices could potentially enable PeLEDs compatible with wearable, foldable, bio‐integrated, and other intriguing functionalities. However, the flexible PeLEDs currently have not received enough attention. The overall performance still lags behind the rigid one, mainly attributed to the lack of mechanically stable perovskite thin films with desirable optical and electrical properties. Herein, a self‐healing strategy to achieve flexible perovskite films with improved mechanical reliability and optoelectrical properties is proposed. A multi‐functional silane molecule of (3,3,3‐trifluoropropyl) trimethoxysilane (TFPTMS) is incorporated into a perovskite precursor, which could undergo an in situ cross‐linking process and generate a flexible Si–O–Si network within the perovskite films. In addition, the reversible hydrolysis and condensation reactions and the fluorinated alkyl chains endow the perovskite films with self‐healing capability. Accordingly, the synergistic influences contribute to high‐efficiency flexible PeLEDs with an external quantum efficiency (EQE) of 16.2%. Moreover, 75% of the initial efficiency value is reserved even after 1000 bending cycles. This work paves a way to rationalize flexible perovskite thin films for various optoelectronic applications.
A cross‐linking strategy to achieve self‐healing perovskite thin film to synthetically improve its optoelectrical and mechanical properties is developed. The in situ formed silica network contributes to high‐performance flexible perovskite light‐emitting diodes with insignificant optoelectrical performance degradation after 1000 cycles bending test.
Solution‐processed white quantum dot light‐emitting diodes (WQLEDs) hold great promise for lighting and backlight applications. Stacked blue/green/red quantum dots (QDs) films as an emitting layer ...through the layer‐by‐layer deposition offer a simple way to realize WQLEDs. However, the redissolution issue rising from the deposition of the adjacent QDs layers prevents the fabrication of high‐quality multilayer emissive layers. Here, a ligand exchange strategy is developed to improve the solvent‐resistance of the QDs films by exposing the QDs films in a trace acid environment. The dissociated hydrions from the acid protonate the aliphatic ligands and desorb them away from QDs’ surface, leaving space for inorganic ions to anchor onto the QDs’ surface. Importantly, the trace acid does not destroy the morphological properties of QDs films and reserves their initial photoluminescence efficiency. In addition, the charge transporting ability of the QDs is enhanced on account of the replaced inorganic ligands. As result, the stacked WQLEDs display pure white emission with Commission International de I'Eclairage coordinates of (0.34, 0.33), and impressive external quantum efficiency of 9.1% has been demonstrated. This solid‐phase ligands exchange strategy provides an alternative way to engineer the surface of QDs for efficient optoelectronics.
The authors report a facile ligands exchange strategy via acid solution rising to rapidly deprotonate the surface organic ligands of the solid quantum dots (QDs) films without any degradation of the intrinsic optical and electrical properties of QDs. This solid‐phase ligand exchange strategy allows us to stack the blue, green, and red QDs films for efficient white light‐emitting diodes.
The first 3-D LaIII–SrII heterometallic complex, namely La2Sr(pda)4(H2O)4n·6nH2O (1, H2pda = pyridine-2,6-dicarboxylic acid), has been successfully synthesized under solvothermal conditions. Single ...crystal X-ray diffraction analysis reveals that complex 1 features a 3-D porous framework and displays a new topology. The crystal structure can be simplified to a 4,6-connected 3-D network with Schläfli symbol of {34·42·88·9}2{34·42}. The crystals also have been characterized by X-ray powder diffraction, elemental analysis, thermal analysis, and IR spectroscopy. The infrared spectral analysis indicates that complex 1 is a carboxylate coordinated compound, several water molecules exist in the compound. The thermal study shows that there are ten water molecules in the crystal structure. The luminescent property has also been investigated. It shows a blue-purple fluorescence emission.
The first 3-D LaIII–SrII heterometallic complex with a new topology has been synthesized; it shows a blue-purple fluorescence emission. Display omitted
•The first 3-D LaIII–SrII complex with a new topology has been synthesized.•It is characterized by IR, TG-DTA and XRD.•The luminescent property of complex 1 was investigated.
The first 3-D La super(III)-Sr super(II) heterometallic complex, namely La sub(2)Sr(pda) sub(4)(H sub(2)O) sub(4) sub(n).6nH sub(2)O (1, H sub(2)pda = pyridine-2,6-dicarboxylic acid), has been ...successfully synthesized under solvothermal conditions. Single crystal X-ray diffraction analysis reveals that complex 1 features a 3-D porous framework and displays a new topology. The crystal structure can be simplified to a 4,6-connected 3-D network with Schlaefli symbol of {3 super(4).4 super(2).8 super(8).9} sub(2){3 super(4).4 super(2)}. The crystals also have been characterized by X-ray powder diffraction, elemental analysis, thermal analysis, and IR spectroscopy. The infrared spectral analysis indicates that complex 1 is a carboxylate coordinated compound, several water molecules exist in the compound. The thermal study shows that there are ten water molecules in the crystal structure. The luminescent property has also been investigated. It shows a blue-purple fluorescence emission.
The liver kinase B1 (LKB1)/5'-adenosine monophosphate-activated protein kinase pathway has been reported to facilitate glioma cell growth by improving growth conditions. To investigate the clinical ...significance of LKB1 in human gliomas western blot analysis and quantitative polymerase chain reaction experiments were performed. The present study demonstrated that LKB1 expression was markedly decreased at the messenger RNA and protein levels in 30 freshly prepared glioma tissues, compared with non-neoplastic brain tissues (P<0.001). Subsequently, immunohistochemical analysis demonstrated that LKB1 immunostaining in 180 glioma tissues was significantly decreased compared with that in the corresponding non-neoplastic brain tissues (P<0.001). Notably, this downregulation frequently occurred in high-grade gliomas, and statistical analysis revealed that low LKB1 expression was significantly associated with large tumor size (P=0.02), advanced World Health Organization grade (P=0.006) and low Karnofsky performance scale (P=0.01). The prognostic value of LKB1 expression in patients with glioma was additionally evaluated using Kaplan-Meier survival curves and Cox proportional hazards regression models. As a result, the overall survival time of patients with glioma with low LKB1 expression was shorter compared with that of patients with high LKB1 expression (P<0.001), and low LKB1 expression also indicated decreased survival time in patients with high-grade glioma (P<0.001). Collectively, the present data indicated that the downregulation of LKB1 was closely associated with the malignant degree of human gliomas, exhibiting lower expression at a higher grade. Notably, LKB1 may serve as a potential prognostic biomarker for patients with glioma following surgery.
Our case reports probe whether intentional replantation is a feasible and successful treatment for teeth with radicular developmental groove. Radicular developmental groove is an anatomical ...malformation that often leads to combined periodontal-endodontic lesion. Treatment of complex radicular groove presents a great challenge to the operator. Two cases of periodontal compromised teeth with this developmental anomaly were treated with intentional replantation and followed up for 2 years. The teeth were asymptomatic and functional. The periodontal probing depths decreased from original 10 mm to 2-3 mm. The receded gingival papillae associated with the teeth was regenerated two years after intentional replantation. With careful case selection and treatment planning, intentional replantation may be a predictable alternative treatment modality for the combined endodontic-periodontal lesion accompanied with radicular developmental groove.
Recent studies have boosted our understanding of long noncoding RNAs （IncRNAs） in numerous biological processes, but few have examined their roles in somatic cell reprogramming. Through expression ...profiling and functional screening, we have identified that the large intergenic noncoding RNA p21 （lincRNAop21） impairs reprogramming. Notably, lincRNA-p21 is induced by p53 but does not promote apoptosis or cell senescence in reprogramming. Instead, lincRNA-p21 associates with the H3K9 methyltransferase SETDB1 and the maintenance DNA methyltransferase DNMT1, which is facilitated by the RNA-binding protein HNRNPK. Consequently, lincRNA-p21 prevents reprogramming by sustaining H3K9me3 and/or CpG methylation at pluripotency gene promoters. Our results provide insight into the role of lncRNAs in reprogramming and establish a novel link between p53 and heterochromatin regulation.
Hyperactivity of the sympathetic nervous system can play an important role in lifelong premature ejaculation (PE). Our previous study found that amyloid precursor protein (APP) levels in seminal ...plasma of patients with PE were clearly increased. Amyloid-β (Aβ) is derived from APP. Excessive Aβ, especially Aβ42, can cause neuronal dysfunction.
To determine whether APP and Aβ42 are associated with an abnormal penile sympathetic skin response (PSSR).
From November 2015 to April 2016, 24 patients with lifelong PE (mean age = 29.2 ± 5.3) with self-estimated intravaginal ejaculatory latency time no longer than 2 minutes and 10 control subjects (mean age = 28.0 ± 5.5) were enrolled consecutively from andrology clinics. PSSR was measured in patients with lifelong PE. APP and Aβ42 levels in seminal plasma were determined.
PSSR in patients with lifelong PE and APP and Aβ42 levels in all subjects.
Patients with PE presented 1.5-fold higher levels of APP (P = .004) than control subjects. Seminal plasma protein concentration (C) in the PE group was lower than that in the control group (P = .007). APP divided by C (APP/C) was 2.0-fold higher (P < .001) in the PE group. Aβ42 level was not different between the PE and control groups, but Aβ42 divided by C (Aβ42/C) was significantly higher in the PE group (P < .001). No differences in APP and APP/C were found between patients with PE in the abnormal and normal PSSR groups. The abnormal PSSR group presented significantly higher Aβ42 (P = .007) and Aβ42/C (P < .001) levels. The latency of PSSR was negatively correlated with Aβ42/C (r = −0.436; P = .033).
These results showed that patients with lifelong PE had higher APP and Aβ42 levels in seminal plasma. Abnormal PSSR was related to a higher Aβ42 level. Drugs that decrease Aβ could be treatment of PE.
Late‑onset hypogonadism is defined as a condition caused by a decline in the levels of testosterone with aging. One of the major factors contributing to the low levels of testosterone is the ...accumulation of reactive oxygen species (ROS) in Leydig cells during the ageing process. Peroxiredoxin 2 (Prdx2), a member of the peroxiredoxin family, is an antioxidant protein, the predominant function of which is to neutralize ROS. However, its role in Leydig cells remains to be elucidated. In the present study, primary Leydig cells were exposed to low concentrations of hydrogen peroxide (H2O2) to induce oxidative stress. Cell apoptosis was measured using an Annexin V fluorescein isothiocyanate/propidium iodide apoptosis detection kit and flow cytometry. The level of testosterone was determined by radioimmunoassay, and the mRNA and protein expression levels of Prdx2 were detected by reverse transcription‑polymerase chain reaction and western blotting, respectively. The results revealed a significant increase in cell apoptosis and decrease in testosterone production. In addition, the expression of Prdx2 was decreased by H2O2 in a dose‑ and time‑dependent manner, and this decrease may have been caused by the induction of its molecular structure transformation due to H2O2 elimination. The above findings indicated that Prdx2 may prevent H2O2 accumulation in Leydig cells, and may be important in oxidative stress‑induced apoptosis and decreased testosterone production.
Heterojunction crystal‐silicon (c‐Si) solar cells generate current from harvesting light via sweeping excited carriers away under built‐in asymmetry through amorphous silicon layers. However, loss of ...energy beyond the bandgap is known to hinder their efficiency. Herein, a strategy is provided to convert short‐wavelength energy into a polarization electrical field and the light dielectric antenna effect, where enhanced surface passivation and carrier collection occur simultaneously. By depositing an ultrathin polarizable nanoparticle layer on a transparent conducting oxide (TCO), a light‐induced electrical field is built up by light‐harvesting accumulation, which benefits for c‐Si surface passivation. An enchanting open‐circuit voltage (Voc) of 736.6 mV for the light‐induced field‐effect solar cell is achieved. In addition, the high‐index dielectric nanoparticles generate more photons to be absorbed in the long‐wavelength in c‐Si solar cells, which results in enhanced short‐circuit current (Jsc). As a result, benefiting from the light‐induced building‐up extra field and dielectric antenna effect, the device yields a power conversion efficiency of 22.41%, with the maximal improvement of Voc (≈4 mV), Jsc (≈0.4 mA cm−2), and fill factor (≈1%), respectively. This work provides a strategy to enhance solar cell efficiency by continuously harvesting beyond‐bandgap light to offer an additional asymmetrical field and the light antenna effect.
Herein, a simple and facile way to enhance the performance of rear‐emitter heterojunction silicon solar cells is reported, through adding a polarizable high‐index nanoparticle layer, which induces a light‐induced electric field and the dielectric antenna effect. The best solar cell with an impressive efficiency of 22.41% is achieved by light‐enhanced crystal‐silicon passivation and improved light harvesting.
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