Perovskite light‐emitting diodes (PeLEDs) show great application potential in high‐quality flat‐panel displays and solid‐state lighting due to their steadily improved efficiency, tunable colors, ...narrow emission peak, and easy solution‐processing capability. However, because of high optical confinement and nonradiative charge recombination during electron–photon conversion, the highest reported efficiency of PeLEDs remains far behind that of their conventional counterparts, such as inorganic LEDs, organic LEDs, and quantum‐dot LEDs. Here a facile route is demonstrated by adopting bioinspired moth‐eye nanostructures at the front electrode/perovskite interface to enhance the outcoupling efficiency of waveguided light in PeLEDs. As a result, the maximum external quantum efficiency and current efficiency of the modified cesium lead bromide (CsPbBr3) green‐emitting PeLEDs are improved to 20.3% and 61.9 cd A−1, while retaining spectral and angular independence. Further reducing light loss in the substrate mode using a half‐ball lens, efficiencies of 28.2% and 88.7 cd A−1 are achieved, which represent the highest values reported to date for PeLEDs. These results represent a substantial step toward achieving practical applications of PeLEDs.
Highly efficient perovskite light‐emitting diodes are achieved by implementing a simple and cost‐effective method for efficient outcoupling of waveguided light. A record external quantum efficiency of 28.2% is realized for the device based on cesium lead bromide (CsPbBr3), while retaining the same spectral response for broad viewing angles.
Developing highly active nonprecious electrocatalysts with superior durability for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial to improve the efficiency ...of overall water splitting but remains challenging. Here, a novel superhydrophilic Co4N‐CeO2 hybrid nanosheet array is synthesized on a graphite plate (Co4N‐CeO2/GP) by an anion intercalation enhanced electrodeposition method, followed by high‐temperature nitridation. Doping CeO2 into Co4N can favor dissociation of H2O and adsorption of hydrogen, reduce the energy barrier of intermediate reactions of OER, and improve the compositional stability, thereby dramatically boosting the HER performance while simultaneously inducing enhanced OER activity. Furthermore, the superhydrophilic self‐supported electrode with Co4N‐CeO2 in situ grown on the conductive substrate expedites electron conduction between substrate and catalyst, promotes the bubble release from electrode timely and impedes catalyst shedding, ensuring a high efficiency and stable working state. Consequently, the Co4N‐CeO2/GP electrode shows exceptionally low overpotentials of 24 and 239 mV at 10 mA cm−2 for HER and OER, respectively. An alkaline electrolyzer by using Co4N‐CeO2/GP as both the cathode and anode requires a cell voltage of 1.507 V to drive 10 mA cm−2, outperforming the Pt/C||RuO2 electrolyzer (1.540 V@10 mA cm−2). More significantly, the electrolyzer has extraordinary long‐term durability at a large current density of 500 mA cm−2 for 50 h, revealing its potential in large‐scale applications.
A superhydrophilic Co4N‐CeO2/graphite plate self‐supported electrode is designed and synthesized via an electrodeposition method, followed by high‐temperature selective nitridation. The coupling of CeO2 into Co4N favors water dissociation and hydrogen adsorption, reduces the energy barrier of intermediate reactions of oxygen evolution reaction, and enhances the compositional stability. Therefore, the Co4N‐CeO2/graphite plate‐based electrolyzer shows outstanding overall water splitting activity with superior stability.
The development of solution‐processed inorganic metal halide perovskite light‐emitting diodes (PeLEDs) is currently hindered by low emission efficiency due to morphological defects and severe ...non‐radiative recombination in all‐inorganic perovskite emitters. Herein, bright PeLEDs are demonstrated by synergetic morphology control over cesium lead bromide (CsPbBr3) perovskite films with the combination of two additives. The phenethylammonium bromide additive enables the formation of mixed‐dimensional CsPbBr3 perovskites featuring the reduced grain size (<15 nm) and efficient energy funneling, while the dielectric polyethyleneglycol additive promotes the formation of highly compact and pinhole‐free perovskite films with defect passivation at grain boundaries. Consequently, green PeLEDs achieve a current efficiency of 37.14 cd A−1 and an external quantum efficiency of 13.14% with the maximum brightness up to 45 990 cd m−2 and high color purity. Furthermore, this method can be effectively extended to realize flexible PeLEDs on plastic substrates with a high efficiency of 31.0 cd A−1.
Bright all‐inorganic CsPbBr3 perovskite light‐emitting diodes are enabled by synergetic morphology control with the combination of two additives, leading to the formation of highly compact and pinhole‐free mixed‐dimensional perovskite films with small grains and defect passivation. The high external quantum efficiency of 13.14% is obtained with high brightness and color purity.
We report a 2-family cluster of persons infected with severe acute respiratory syndrome coronavirus 2 in the city of Zhoushan, Zhejiang Province, China, during January 2020. The infections resulted ...from contact with an infected but potentially presymptomatic traveler from the city of Wuhan in Hubei Province.
Although many solar‐driven water evaporators are developed for solar steam generation, most solarthermal energy conversion materials cannot be used repeatedly for constructing solarthermal water ...evaporators with variable shapes and patternable surfaces. Herein, reshapable Ti3C2Tx MXene/graphene oxide (GO)/polyaniline (PANI) (MGP) hybrids with variable shapes and patternable surfaces are fabricated by PANI‐assisted assembly of GO and MXene for efficient solar‐driven purifications of both seawater and wastewater. The variable shapes, patternable surfaces, and reusability of the plastic MGP hybrids are attributed to the strong interactions of PANI with both GO and MXene. Benefiting from the excellent solarthermal energy conversion of hydrophilic GO and MXene, the variable shapes and patternable surfaces of the MGP, and the reduced water vaporization enthalpy, the patternable MGP evaporators with flat and concave pyramid surfaces exhibit average water evaporation rates of as high as 2.89 and 3.30 kg m−2 h−1 under 1‐sun irradiation, respectively. When the plastic MGP is molded to a flower‐shaped evaporator, an outstanding evaporation rate of ≈3.94 kg m−2 h−1 with an exceptional evaporation efficiency of ≈135.6% is achieved under 1‐sun irradiation. The reusable MGP evaporators are highly efficient in generating clean water from both seawater and wastewater with satisfactory ion rejection rates of nearly 100%.
Reshapable Ti3C2Tx MXene/graphene oxide (GO)/polyaniline (PANI) (MGP) hybrids with variable shapes and patternable surfaces are fabricated for efficient solar‐driven purifications of both seawater and wastewater by PANI‐assisted assembly of GO and MXene. The patternable MGP evaporators with a concave pyramid surface and a flower‐like shape exhibit outstanding water evaporation rates of 3.30 and 3.94 kg m−2 h−1 under 1‐sun irradiation, respectively.
The electrochemical nitrogen reduction reaction (NRR) offers an energy‐saving and environmentally friendly approach to produce ammonia under ambient conditions. However, traditional catalysts have ...extremely poor NRR performances because of their low activity and the competitive hydrogen evolution reaction. The high catalytic activity of nanoporous gold (NPG) and the hydrophobicity and molecular concentrating effect of the zeolitic imidazolate framework‐8 (ZIF‐8) were incorporated in the NPG@ZIF‐8 nanocomposite so that the ZIF‐8 shell could weaken hydrogen evolution and retard reactant diffusion. A highest Faradaic efficiency of 44 % and an excellent rate of ammonia production of (28.7±0.9) μg h−1 cm−2 were achieved, which are superior to traditional gold nanoparticles and NPG. Moreover, the composite catalyst shows high electrochemical stability and selectivity (98 %). The superior NRR performance makes NPG@ZIF‐8 one of the most promising water‐based NRR electrocatalysts for ammonia production.
Being efficient: A core–shell structure composite of nanoporous gold embedded in a ZIF‐8 shell has been developed. The high catalytic activity of the nanoporous gold and the hydrophobic porous shell of ZIF‐8 results in a superior enhancement of electrochemical nitrogen fixation compared to traditional electrocatalysts, as shown by a Faradaic efficiency of 44 % (see picture, scale bar: 300 nm).
Cost‐effective aqueous rechargeable batteries are attractive alternatives to non‐aqueous cells for stationary grid energy storage. Among different aqueous cells, zinc‐ion batteries (ZIBs), based on ...Zn2+ intercalation chemistry, stand out as they can employ high‐capacity Zn metal as the anode material. Herein, we report a layered calcium vanadium oxide bronze as the cathode material for aqueous Zn batteries. For the storage of the Zn2+ ions in the aqueous electrolyte, we demonstrate that the calcium‐based bronze structure can deliver a high capacity of 340 mA h g−1 at 0.2 C, good rate capability, and very long cycling life (96 % retention after 3000 cycles at 80 C). Further, we investigate the Zn2+ storage mechanism, and the corresponding electrochemical kinetics in this bronze cathode. Finally, we show that our Zn cell delivers an energy density of 267 W h kg−1 at a power density of 53.4 W kg−1.
A new cathode material, layered calcium vanadium oxide bronze, was synthesized for aqueous zinc‐ion battery applications. The calcium‐based bronze shows promising performance for storage of Zn2+ ions from the aqueous electrolyte (see picture). The Zn cell delivers an energy density of 267 W h kg−1 at a power density of 53.4 W kg−1.
Abstract
Context
Ultrasound (US)-guided thermal ablation has generated recent interest as minimally invasive treatments of primary hyperparathyroidism (pHPT). But definitive evidence for the efficacy ...of thermal ablation in treating pHPT is not well characterized.
Objective
This work aims to evaluate the effectiveness and safety of thermal ablation for pHPT.
Methods
From January 2015 to March 2020, data pertaining to patients who received thermal ablation for pHPT at 4 centers were retrospectively analyzed. The median follow-up duration was 18.1 months (interquartile range, 6.5-42.2 months). A cure referred to the reestablishment of normal values of serum calcium and intact parathyroid hormone throughout the entire follow-up period, at least more than 6 months. The technical success, effectiveness, and safety of treatment were analyzed.
Results
A total of 119 patients (mean age, 57.2 ± 16.3 years; 81 female) with 134 parathyroid nodules were enrolled. The mean maximum diameter of the parathyroid glands was 1.6 ± 0.9 cm. Ninety-six patients underwent microwave ablation (MWA), and 23 patients underwent radiofrequency ablation (RFA). The technical success rate was 98.3% and the cure rate was 89.9%. Significant differences were found in the maximum diameter between the cured patients and the patients who did not undergo ablation of the target lesions. Except for cases with pHPT nodules less than 0.6 cm in diameter, the cure rate was 95%. There were no difference in cure rates at 6 months between the MWA and RFA groups (MWA vs RFA, 90.6% vs 87.0%; χ 2 = 0.275, P = .699). The volume reduction rate of the ablation zone was 94.6% at 12 months. The complication rate was 6.7% (8/119). With the exception of one patient with persistent voice impairment, other symptoms spontaneously resolved within 6 months.
Conclusion
Thermal ablation is effective and safe for pHPT.
Little is known about the inter-relationship among fruit and vegetable intake, gut microbiota and metabolites, and type 2 diabetes (T2D) in human prospective cohort study. The aim of the present ...study was to investigate the prospective association of fruit and vegetable intake with human gut microbiota and to examine the relationship between fruit and vegetable-related gut microbiota and their related metabolites with type 2 diabetes (T2D) risk.
This study included 1879 middle-age elderly Chinese adults from Guangzhou Nutrition and Health Study (GNHS). Baseline dietary information was collected using a validated food frequency questionnaire (2008-2013). Fecal samples were collected at follow-up (2015-2019) and analyzed for 16S rRNA sequencing and targeted fecal metabolomics. Blood samples were collected and analyzed for glucose, insulin, and glycated hemoglobin. We used multivariable linear regression and logistic regression models to investigate the prospective associations of fruit and vegetable intake with gut microbiota and the association of the identified gut microbiota (fruit/vegetable-microbiota index) and their related fecal metabolites with T2D risk, respectively. Replications were performed in an independent cohort involving 6626 participants.
In the GNHS, dietary fruit intake, but not vegetable, was prospectively associated with gut microbiota diversity and composition. The fruit-microbiota index (FMI, created from 31 identified microbial features) was positively associated with fruit intake (p < 0.001) and inversely associated with T2D risk (odds ratio (OR) 0.83, 95%CI 0.71-0.97). The FMI-fruit association (p = 0.003) and the FMI-T2D association (OR 0.90, 95%CI 0.84-0.97) were both successfully replicated in the independent cohort. The FMI-positive associated metabolite sebacic acid was inversely associated with T2D risk (OR 0.67, 95%CI 0.51-0.86). The FMI-negative associated metabolites cholic acid (OR 1.35, 95%CI 1.13-1.62), 3-dehydrocholic acid (OR 1.30, 95%CI 1.09-1.54), oleylcarnitine (OR 1.77, 95%CI 1.45-2.20), linoleylcarnitine (OR 1.66, 95%CI 1.37-2.05), palmitoylcarnitine (OR 1.62, 95%CI 1.33-2.02), and 2-hydroglutaric acid (OR 1.47, 95%CI 1.25-1.72) were positively associated with T2D risk.
Higher fruit intake-associated gut microbiota and metabolic alteration were associated with a lower risk of T2D, supporting the public dietary recommendation of adopting high fruit intake for the T2D prevention.
Cervical lymph node metastasis (CLNM) is common in patients with papillary thyroid carcinoma (PTC), which is responsible for tumor staging and surgical strategy. The accurate preoperative ...identification of CLNM is essential. In this study, twenty consecutive patients with PTC received a parenchyma injection of Sonazoid followed by contrast enhanced ultrasound (CEUS) to identify CLNM. The specific lymphatic CEUS (LCEUS) signs for diagnosing CLNM were summarized, which were further compared with the resected specimens to get the pathological basis. After the injection of contrast agent, lymphatic vessel and lymph node (LN) could be exclusively displayed as hyperperfusion on LCEUS. The dynamic perfusion process of contrast agent in CLNM over time can be clearly visualized. Perfusion defect and interruption of bright ring were the two characteristic LCEUS signs in diagnosing CLNM. After comparing with pathology, perfusion defect was correlated to the metastatic foci in medulla and interruption of bright ring was correlated to the tumor seeding in marginal sinus (all p values < 0.001). The diagnostic efficacies of these two signs were high (perfusion defect vs. interruption of bright ring: AUC, 0.899, 95% CI 0.752-1.000 vs. 0.904, 0.803-1.000). LCEUS has advantages in identifying CLNM from PTC. The typical LCEUS signs of CLNM correlated with pathology.
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