Single‐atom catalysts (SACs) have received widespread interest for their high atomic efficiency, enriched active sites, excellent catalytic performance, and low cost. However, the agglomeration of ...single metal atoms and the use of inactive additives for affixing powdery SACs on planar electrodes may reduce the density of active sites, diminish the charge transport to active sites, and thus suppress their performance. Herein, a series of metal–nitrogen–carbon single‐atom aerogels (M‐SAAs, M: Cu, Ni, Au, Ru) are synthesized via a universal strategy, in which the merits of metal organic frameworks and carbon aerogels are perfectly combined to prevent the agglomeration of single metal atoms and overcome the problem of poor electrical conductivity. The as‐prepared M‐SAAs can be directly employed as self‐supporting electrodes for the electrochemical dechlorination of 1,2‐dichloroethane, and outstanding activity and stability are observed. Significantly, the Cu‐SAA with abundant Cu−N4 sites shows an extraordinarily high ethylene production rate of 446 µmol h−1, with a selectivity of 99% and Faradaic efficiency of 64%. Moreover, theoretical calculations are performed to demonstrate the selectivity and activity of different metal active sites. This study provides a new strategy to exploit highly effective SACs and offers an intensive insight into the mechanism of electrochemical dechlorination reactions.
A series of metal–nitrogen–carbon single‐atom aerogels are developed via a new strategy and employed as self‐supporting electrodes for the electrochemical dechlorination of 1,2‐dichloroethane. The strategy can not only prevent the agglomeration of metal atoms, but also overcome the poor electrical conductivity caused by the binder. Therefore, the electrodes show outstanding performance with high ethylene production rate, selectivity, and Faradaic efficiency.
Li–S batteries present great potential to realize high-energy-density storage, but their practical implementation is severely hampered by the notorious polysulfide shuttling and the sluggish redox ...kinetics. While rationally designed redox mediators can optimize polysulfide conversion, the efficiency and stability of such a mediation process still remain formidable challenges. Herein, a strategy of constructing a “dual mediator system” is proposed for achieving efficient and durable modulation of polysulfide conversion kinetics by coupling well-selected solid and electrolyte-soluble mediators. Theoretical prediction and detailed electrochemical analysis reveal the structure–activity relationships of the two mediators in synergistically optimizing the redox conversions of sulfur species, thus achieving a deeper mechanistic understanding of a function-supporting mediator system design toward sulfur electrochemistry promotion. Specifically, such a dual mediator system realizes the bridging of full-range “electrochemical catalysis” and strengthened “chemical reduction” processes of sulfur species as well as greatly suppressed mediator deactivation/loss due to the beneficial interactions between each mediator component. Attributed to these advantageous features, the Li–S batteries enable a slow capacity decay of 0.026% per cycle over 1200 cycles and a desirable capacity of 8.8 mAh cm–2 with 8.2 mg cm–2 sulfur loading and lean electrolyte condition. This work not only proposes an effective mediator system design strategy for promoting Li–S battery performance but also inspires its potential utilization facing other analogous sophisticated electrochemical conversion processes.
Abstract Aqueous zinc ion batteries have received unprecedented attention owing to their superior safety and sustainability, yet their cycling stability especially at high current rates is greatly ...limited by the poor reversibility of Zn metal anodes, due to the delayed ion transport, severe water‐induced side reactions, and uncontrollable dendrites growth at electrolyte/electrode interface. Herein, a robust and multi‐scale functionally designed amorphous ZnWO 4 (ZWO) artificial interphase that fully addresses the aforementioned issues, is proposed. The modified Zn anodes deliver remarkable stability, surpassing 3000 h of operation at a high current density of 20 mA cm −2 in symmetrical cells. Even under harsh conditions of 20 mA cm −2 and 10 mAh cm −2 , the electrode demonstrates steady cycling for over 600 h with low overpotential. The excellent cycling stability and rate performance are mainly attributed to a range of collective functionalities of ZWO interphase, including short‐range and isotropic ion migration, superior ion‐screening capability, and a thermodynamically enhanced energy barrier for hydrogen evolution reaction (HER) during Zn plating. These findings highlight the significance of the multi‐scale functional interphase in overcoming key barriers associated with zinc anodes under high current density, offering a facile and insightful approach for achieving high‐performance Zn metal anodes.
Photocatalytic conversion of polyols to value-added products is of great interest for the utilization of biomass as a chemical feedstock. Current research focuses on boosting the reaction rate and ...selectivity by employing metal nanoparticles (NPs) as charge separators and cocatalysts. However, the promotional role of metal NPs in such photocatalytic processes still remains unclear because of the lack of mechanistic understanding. Here, we have explored the role of supported Pd and Au NPs on TiO2 in photocatalytic glycerol conversion under water-free, deaerated conditions by in situ spectroscopic methods. While the presence of Au NPs only results in partial conversion of glycerol at a low rate, Pd decoration promotes glycerol oxidation to a much higher conversion. In situ mass and vibrational spectrometry reveals that Pd/TiO2 exhibits faster cleavage of O–H and C–H bonds in both glycerol and the derived intermediates as compared to Au/TiO2, thus leading to a higher glycerol conversion accompanied by the formation of additional molecular hydrogen. X-ray photoelectron spectroscopy suggests that the preferential adsorption of glycerol on the surface of Pd via hydroxyl groups results in an enhanced interfacial charge transfer, thus yielding a better photocatalytic activity.
The introduction of NCIL simultaneously achieves a rapid Zn2+ desolvation, homogeneous Zn2+ spatial distribution and the construction of ion-screening interface, thus contributing to a kinetically ...enhanced and dendrites-free galvanization process.
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Suppression of uncontrollable dendrite growth and water-induced side reactions of Zn metal anodes is crucial for achieving long-lasting cycling stability and facilitating the practical implementations of aqueous Zn-metal batteries. To address these challenges, we report in this study a functional nitro-cellulose interfacial layer (NCIL) on the surface of Zn anodes enlightened by a nitro-coordination chemistry strategy. The NCIL exhibits strong zincophilicity and superior coordination capability with Zn2+ due to the highly electronegative and highly nucleophilic nature of the nitro functional group. This characteristic facilitates a rapid Zn-ion desolvation process and homogeneous Zn plating, effectively preventing H2 evolution and dendrite formation. Additionally, the negatively charged surface of NCIL acts as a shield, repelling SO42− anions and inhibiting corrosive reactions on the Zn surface. Remarkably, reversible and stable Zn plating/stripping is achieved for over 5100 h at a current density of 1 mA cm−2, which is nearly 30 times longer than that of bare Zn anodes. Furthermore, the Zn//V2O5 full cells with the functional interface layer deliver a high-capacity retention of 80.3% for over 10,000 cycles at 5 A g−1. This research offers valuable insights for the rational development of advanced protective interface layers in order to achieve ultra-long-life Zn metal batteries.
With the improvements in sensor performance (cameras, Lidars) and the application of deep learning in object detection, autonomous vehicles (AVs) are gradually becoming more notable. After 2019, AV ...has produced a wave of enthusiasm, and many papers on object detection were published, boasting both practicality and innovation. Due to hardware limitations, it is difficult to accomplish accurate and reliable environment perception using a single sensor. However, multi-sensor fusion technology provides an acceptable solution. Considering the AV cost and object detection accuracy, both the traditional and existing literature on object detection using image and point-cloud was reviewed in this paper. Additionally, for the fusion-based structure, the object detection method was categorized in this paper based on the image and point-cloud fusion types: early fusion, deep fusion, and late fusion. Moreover, a clear explanation of these categories was provided including both the advantages and limitations. Finally, the opportunities and challenges the environment perception may face in the future were assessed.
Human embryonic stem cells (hESCs) can be self-propagated indefinitely in culture while holding the capacity to generate almost all cell types. Although this powerful differentiation ability of hESCs ...has become a potential source of cell replacement therapies, application of stem cells in clinical practice relies heavily on the exquisite control of their developmental fate. In general, an essential first step in differentiation is to exit the pluripotent state, which is precariously balanced and depends on a variety of factors, mainly centering on the core transcriptional mechanism. To date, much evidence has indicated that transcription factors such as Sox2, Oct4, and Nanog control the self-renewal and pluripotency of hESCs. Their expression displays a restricted spatial-temporal pattern and their small changes in level can significantly affect directed differentiation and the cell type derived. So far, few assays have been developed to monitor this process. Herein, we provided a mass spectrometry (MS)–based approach for simultaneous and quantitative monitoring of these transcription factors, in an attempt to provide insight into their contributions in hESC differentiation.
Interleukin-18 binding protein (IL-18BP) is a natural IL-18 inhibitor
in vivo
, which can effectively neutralize IL-18 and inhibit the inflammatory signaling pathway induced by IL-18, thus playing an ...anti-inflammatory role. Traditional production methods primarily rely on eukaryotic animal cell expression systems, which often entail complex processes, lower yields, and increase production costs. In this study, we present a novel approach for expressing IL-18BP fusion protein using the
Escherichia coli
(
E. coli
) system. The N-terminal segment of IL-18BP was fused with the small ubiquitin-related modifier (SUMO) tag, enabling soluble expression, while the C-terminal segment was fused with the human IgG1 Fc fragment to prolong its
in vivo
lifespan. Through screening, we obtained a high-expression engineering strain from a single colony and developed optimized protocols for fermentation and purification of the recombinant SUMO-IL-18BP-Fc protein. The SUMO tag was subsequently cleaved using SUMO protease, and the purified recombinant human IL-18BP-Fc (rhIL-18BP-Fc) exhibited a purity exceeding 90% with a yield of 1 g per liter of bacterial solution. The biological activities and underlying mechanisms of rhIL-18BP-Fc were evaluated using cell lines and a mouse model. Our results demonstrated that rhIL-18BP-Fc effectively inhibited IL-18-stimulated IFN-γ production in KG-1a cells
in vitro
and ameliorated DSS-induced ulcerative colitis in mice. In conclusion, we successfully employed the SUMO fusion system to achieve high-level production, soluble expression, and prolonged activity of rhIL-18BP-Fc in
E. coli
. These findings lay the groundwork for future large-scale industrial production and pharmaceutical development of rhIL-18BP-Fc protein.
Key points
•
Effective expression, fermentation, and purification of bioactive rhIL-18BP-Fc protein in E. coli.
•
The rhIL-18BP-Fc protein has a great potential for the therapy of ulcerative colitis by inhibiting the expression of inflammatory factors.
Halobenzoquinones are frequently detected as disinfection by-products in drinking water. Among identified halobenzoquinones, 2,6-dichloro-1,4-benzoquinone (2,6-DCBQ) is particularly toxic and is ...frequently detected in drinking water. Synthetic aromatic antioxidants discharged to source water may increase the risk of 2,6-DCBQ formation, as many studies suggest that aromatic compounds are the most likely precursors to 2,6-DCBQ. Herein, we investigated the formation of 2,6-DCBQ from chlorination of three model aromatic antioxidants, including 3-tert-butyl-4-hydroxyanisole (BHA), 2,6-di-tert-butyl-4-methylphenol (BHT) and bis(4-tert-butylphenyl)amine (BBPA). Only BBPA produced 2,6-DCBQ under chlorination, while chlorination of BHA and BHT formed α, β-unsaturated C4-dicarbonyl ring-opening products and phenolic compounds. Based on mass balance and intermediate transformation analysis, mechanisms for the formation of 2,6-DCBQ from BBPA chlorination involved hydrolysis, tert-butyl group cleavage, chlorine substitution, desamination and oxidation. Mitigating aromatic compounds will be an efficient method for 2,6-DCBQ control, such as pre-ozonation, because the intermediates involved in 2,6-DCBQ formation were aromatic compounds. Real water samples from two drinking water treatment plants (DWTPs), one with pre-ozonation (DWTP 2) and the other without pre-ozonation (DWTP1), were analyzed. The two DWTPs were built along the Yangtse river in Nanjing city. Raw water parameters from the two DWTPs, including dissolved organic carbon (DOC), UV absorbance at 254 nm (UV254) and NH3–N, indicated the water quality between these sources was similar. Pre-ozonation in DWTP 2 vanished 2,6-DCBQ in raw water. Concentrations of 2,6-DCBQ in finished water from DWTP 1 (5.69 ng/L) was higher than concentrations generated from DWTP 2 (1.31 ng/L). These results demonstrate that pre-ozonation, granular activated carbon (GAC) and quartz sand treatments at DWTP 2 remove more 2,6-DCBQ precursors than the conventional quartz sand and GAC treatments in DWTP 1. These results suggest the pre-ozonation, GAC and quartz sand treatments can help minimize concentrations of 2,6-DCBQ generated in DWTPs.
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•Bis(4-tert-butylphenyl)amine with large steric hindrance is a precursor for 2,6-DCBQ.•Aromatic intermediates are the key intermediates for 2,6-DCBQ formation.•Ozone decomposed 2,6-DCBQ in raw water.•Ozone, GAC and quartz sand removed 2,6-DCBQ precursors effectively.
Understanding how biophysical and biochemical microenvironmental cues together influence the regenerative activities of muscle stem cells and their progeny is crucial in strategizing remedies for ...pathological dysregulation of these cues in aging and disease. In this study, we investigated the cell-level influences of extracellular matrix (ECM) ligands and culture substrate stiffness on primary human myoblast contractility and proliferation within 16 h of plating and found that tethered fibronectin led to stronger stiffness-dependent responses compared to laminin and collagen. A proteome-wide analysis further uncovered cell metabolism, cytoskeletal and nuclear component regulation distinctions between cells cultured on soft and stiff substrates. Interestingly, we found that softer substrates increased the incidence of myoblasts with a wrinkled nucleus, and that the extent of wrinkling could predict Ki67 (also known as MKI67) expression. Nuclear wrinkling and Ki67 expression could be controlled by pharmacological manipulation of cellular contractility, offering a potential cellular mechanism. These results provide new insights into the regulation of human myoblast stiffness-dependent contractility response by ECM ligands and highlight a link between myoblast contractility and proliferation.
