The MXene‐based heterostructures have recently attracted great interest as anode materials for sodium‐ion batteries (SIBs). Nonetheless, the complicated and harsh preparation process impedes their ...further commercialization. Herein, a novel, safe, low‐destructive, and universal strategy for rationally fabricating Ti3C2Tx MXene/transition metal sulfides (MSy) heterostructures is presented via Lewis acidic molten salts etching and subsequent in situ sulfurization treatment. Benefiting from the interfacial electronic coupling between highly conductive Ti3C2Tx MXene (Tx = O and Cl) and MSy (M = Fe, Co and Ni), the heterostructures possess remarkably improved electronic conductivity, promoted Na+ migration kinetics, and robust architectures. As a proof‐of‐concept demonstration, the Ti3C2Tx/FeS2 heterostructure demonstrates outstanding rate performance (456.6 mAh g−1 at 10 A g−1) and long‐term cyclic stability (474.9 mAh g−1 after 600 cycles at 5 A g−1) when serving as SIB anodes. Impressively, a sodium‐ion full battery with Ti3C2Tx/FeS2 anode delivers an excellent reversible capacity of 431.6 mAh g−1 after 1000 cycles at 3 A g−1. Moreover, the dual sodium storage behavior of Ti3C2Tx/FeS2 heterostructure and underlying mechanism toward exceptional electrochemical performance are revealed by comprehensive characterizations and theoretical calculations. Based on the full utilization of molten salt etching products, the present work offers new insight into the fabrication of MXene‐based heterostructures.
A series of Ti3C2Tx MXene/MSy heterostructures (Tx = O and Cl, M = Fe, Co, and Ni) are fabricated by directly vulcanizing Ti3C2Tx/metal hybrids obtained by etching a Ti3AlC2 MAX precursor with various Lewis acidic molten salts, which is a simple, safe, low‐destructive, and general strategy. The heterostructures present superior electrochemical performance as anode materials for sodium‐ion batteries derived from the interfacial electronic coupling effect.
It is demonstrated that carbon quantum dots derived from curcumin (Cur‐CQDs) through one‐step dry heating are effective antiviral agents against enterovirus 71 (EV71). The surface properties of ...Cur‐CQDs, as well as their antiviral activity, are highly dependent on the heating temperature during synthesis. The one‐step heating of curcumin at 180 °C preserves many of the moieties of polymeric curcumin on the surfaces of the as‐synthesized Cur‐CQDs, resulting in superior antiviral characteristics. It is proposed that curcumin undergoes a series of structural changes through dehydration, polymerization, and carbonization to form core–shell CQDs whose surfaces remain a pyrolytic curcumin‐like polymer, boosting the antiviral activity. The results reveal that curcumin possesses insignificant inhibitory activity against EV71 infection in RD cells half‐maximal effective concentration (EC50) >200 µg mL−1 but exhibits high cytotoxicity toward RD cells (half‐maximal cytotoxic concentration (CC50) <13 µg mL−1). The EC50 (0.2 µg mL−1) and CC50 (452.2 µg mL−1) of Cur‐CQDs are >1000‐fold lower and >34‐fold higher, respectively, than those of curcumin, demonstrating their far superior antiviral capabilities and high biocompatibility. In vivo, intraperitoneal administration of Cur‐CQDs significantly decreases mortality and provides protection against virus‐induced hind‐limb paralysis in new‐born mice challenged with a lethal dose of EV71.
Biocarbon quantum dots: a simple one‐step dry heating allows the synthesis of carbon quantum dots derived from curcumin. The obtained carbon quantum dots possess strong antiviral activity against enterovirus 71 through different mechanisms.
Aiming for increased nickel and lower cobalt content in layered transition metal oxide cathodes (NCM) is a feasible strategy for achieving increased energy density and cost competitiveness in ...commercial lithium‐ion batteries. However, the practical long‐term cycling of NCM cathodes suffers from severe capacity degradation due to irreversible interface phase transformation and unavoidable crack formation. Herein, an in situ modification strategy is used to form a uniform and conformal Li1.8Sc0.8Ti1.2(PO4)3 (LSTP) protective layer by interconnecting the single‐crystal‐layered LiNi0.6Co0.1Mn0.3O2 (SC‐NCM) particles. LSTP surface modification helps to construct a robust cathode‐electrolyte interphase thin film between the cathode and the electrolyte, which can prevent SC‐NCM corrosion by electrolyte, and the stability of the mechanics can improve the intergranular cracks caused by long cycles under harsh conditions. Moreover, the LSTP conductive modification layer facilitates the lithium‐ion transport among cathode particles, effectively enhancing the rate capability. Impressively, the LSTP modified SC‐NCM exhibits a high reversible capacity of 144.3 mAh g−1 at the high discharge rate of 5 C and maintains a capacity retention of 90.27% even at the ultrahigh charge voltage of 4.6 V operation after 500 cycles. Moreover, in a pouch‐type full battery, the graphite/LSTP modified SC‐NCM maintains a capacity retention of 89.6% after 1700 cycles.
An innovative surface modification is developed to improve the long‐term cyclability and rate capability of a single‐crystalline Ni‐rich cathode. The surface modification strategy improves the mechanical stability and lithium‐ion transport, which creates a strong CEI interface to prevent electrolyte corrosion and improve the intergranular cracks caused by long cycles under harsh conditions.
The systemic spread of colorectal cancer (CRC) is dominated by the portal system and exhibits diverse patterns of metastasis without systematical genomic investigation. Here, we evaluated the genomic ...evolution of CRC with multiorgan metastases using multiregion sequencing.
Whole-exome sequencing was performed on multiple regions (n=74) of matched primary tumour, adjacent non-cancerous mucosa, liver metastasis and lung metastasis from six patients with CRC. Phylogenetic reconstruction and evolutionary analyses were used to investigate the metastatic seeding pattern and clonal origin. Recurrent driver gene mutations were analysed across patients and validated in two independent cohorts. Metastatic assays were performed to examine the effect of the novel driver gene on the malignant behaviour of CRC cells.
Based on the migration patterns and clonal origins, three models were revealed (sequential, branch-off and diaspora), which not only supported the anatomic assumption that CRC cells spread to lung after clonally expanding in the liver, but also illustrated the direct seeding of extrahepatic metastases from primary tumours independently. Unlike other cancer types, polyphyletic seeding occurs in CRC, which may result in late metastases with intermetastatic driver gene heterogeneity. In cases with rapid dissemination, we found recurrent trunk loss-of-function mutations in
, which is enriched in metastatic CRC and associated with poor overall survival. CRISPR/Cas9-mediated knockout of
enhances the metastatic potential of CRC cells.
Our results provide genomic evidence for metastatic evolution and indicate that biopsy/sequencing of metastases may be considered for patients with CRC with multiorgan or late postoperative metastasis.
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•Metal nanozyme-based detection of heavy metal ions is reviewed.•Detection strategies for improving selectivity and reliability are reviewed.•The challenges in nanozyme-based assays ...for heavy metal ions are highlighted.•Future perspective of nanozyme-based assays for heavy metal ions is discussed.
Large scale mining, manufacturing industries, exploitation of underground water, depletion of groundwater level, and uncontrolled discharge of industrial wastes have caused severe heavy metal ion pollution to the environment throughout the world. Therefore, the rapid detection of such toxic metal ions is inevitable. However, conventional methods require sophisticated instruments and skilled manpower and are difficult to operate in on-field conditions. Recently, metal nanozyme-based assays have been found to have the potential as an alternative to conventional methods due to their portability, simplicity, and high sensitivity to detect metal ion concentration to as low as parts per trillion (ppt). Metal nanozyme-based systems for heavy metal ions enable rapid and cheap screening on the spot with a very simple instrument such as a UV–vis absorption spectrophotometer and therefore, are convenient for use in field operations, especially in remote parts of the world. The sensing mechanism of a nanozyme-based sensor is highly dependent on its surface properties and specific interactions with particular metal ion species. Such method often encounters selectivity issues, unlike natural enzyme-based assays. Therefore, in this review, we mainly focus our discussion on different types of target recognition and inhibition/enhancement mechanisms, and their responses toward the catalytic activity in the sensing of target metal ions, design strategies, challenges, and future perspectives.
Metal-organic frameworks (MOFs) have recently garnered consideration as an attractive solid substrate because the highly tunable MOF framework can not only serve as an inert host but also enhance the ...selectivity, stability, and/or activity of the enzymes. Herein, we demonstrate the advantages of using a mechanochemical strategy to encapsulate enzymes into robust MOFs. A range of enzymes, namely β-glucosidase, invertase, β-galactosidase, and catalase, are encapsulated in ZIF-8, UiO-66-NH
, or Zn-MOF-74 via a ball milling process. The solid-state mechanochemical strategy is rapid and minimizes the use of organic solvents and strong acids during synthesis, allowing the encapsulation of enzymes into three prototypical robust MOFs while maintaining enzymatic biological activity. The activity of encapsulated enzyme is demonstrated and shows increased resistance to proteases, even under acidic conditions. This work represents a step toward the creation of a suite of biomolecule-in-MOF composites for application in a variety of industrial processes.
Cancer-associated fibroblasts (CAFs) are the predominant components of the tumor microenvironment (TME) and influence cancer hallmarks, but without systematic investigation on their ubiquitous ...characteristics across different cancer types. Here, we perform pan-cancer analysis on 226 samples across 10 solid cancer types to profile the TME at single-cell resolution, illustrating the commonalities/plasticity of heterogenous CAFs. Activation trajectory of the major CAF types is divided into three states, exhibiting distinct interactions with other cell components, and relating to prognosis of immunotherapy. Moreover, minor CAF components represent the alternative origin from other TME components (e.g., endothelia and macrophages). Particularly, the ubiquitous presentation of endothelial-to-mesenchymal transition CAF, which may interact with proximal SPP1
tumor-associated macrophages, is implicated in endothelial-to-mesenchymal transition and survival stratifications. Our study comprehensively profiles the shared characteristics and dynamics of CAFs, and highlight their heterogeneity and plasticity across different cancer types. Browser of integrated pan-cancer single-cell information is available at https://gist-fgl.github.io/sc-caf-atlas/ .
Effective thermal conductivity is an important property of composites for different thermal management applications. Although physics-based methods, such as effective medium theory and solving ...partial differential equations, are widely applied to extract effective thermal conductivity, recently there is increasing interest to establish the structure-property linkage through machine learning methods. The prediction accuracy of conventional machine learning methods highly depends on the features (descriptors) selected to represent the microstructures. In comparison, 3D convolutional neural networks (CNNs) can directly extract geometric features of composites, which have been demonstrated to establish structure-property linkages with high accuracy. However, to obtain the 3D microstructure in the composite is challenging in reality. In this work, we use 2D cross-section images and 2D CNNs to predict effective thermal conductivity of 3D composites, since 2D pictures can be much easier to obtain in real applications. The results show that by using multiple cross-section images along or perpendicular to the preferred directionality of the fillers, 2D CNNs can provide quite accurate prediction. Such a result is demonstrated with isotropic particle filled composites and anisotropic stochastic complex composites. In addition, we also discuss how to select representative cross-section images. It is found that the average over multiple images and the use of large-size images can reduce the uncertainty and increase the prediction accuracy. Besides, since cross-section images along the heat flow direction can distinguish between serial structures and parallel structures, they are more representative than cross-section images perpendicular to the heat flow direction.
Highlights
As an emerging preparation strategy for MXenes, Lewis acidic etching has attracted increasing attention in the past few years benefiting from a series of merits.
Lewis acidic etching ...method is mainly presented from etching mechanism, terminations regulation, in-situ formed metals and delamination of multi-layered MXenes.
The applications of MXenes and MXene-based composites obtained by Lewis acidic etching route in energy storage and conversion, sensors and microwave absorption are carefully summarized.
Since the discovery in 2011, MXenes have become the rising star in the field of two-dimensional materials. Benefiting from the metallic-level conductivity, large and adjustable gallery spacing, low ion diffusion barrier, rich surface chemistry, superior mechanical strength, MXenes exhibit great application prospects in energy storage and conversion, sensors, optoelectronics, electromagnetic interference shielding and biomedicine. Nevertheless, two issues seriously deteriorate the further development of MXenes. One is the high experimental risk of common preparation methods such as HF etching, and the other is the difficulty in obtaining MXenes with controllable surface groups. Recently, Lewis acidic etching, as a brand-new preparation strategy for MXenes, has attracted intensive attention due to its high safety and the ability to endow MXenes with uniform terminations. However, a comprehensive review of Lewis acidic etching method has not been reported yet. Herein, we first introduce the Lewis acidic etching from the following four aspects: etching mechanism, terminations regulation, in-situ formed metals and delamination of multi-layered MXenes. Further, the applications of MXenes and MXene-based hybrids obtained by Lewis acidic etching route in energy storage and conversion, sensors and microwave absorption are carefully summarized. Finally, some challenges and opportunities of Lewis acidic etching strategy are also presented.
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•N-doped carbon-encapsulated CoS2 are firstly anchored on MXene via Ti-O-C bonds.•A dual protection effect on CoS2 nanoparticles during cycling can be achieved.•The anodes exhibit ...ultralong cycle lifespan and superior rate performance.•The full cells show a high reversible capacity and stable cycling performance.
Sodium-ion batteries (SIBs) based on conversion-type anode materials exhibit great prospect in the field of large-scale energy storage because of their superior sodiation capacities and low costs. However, poor charge transfer kinetics and short cycle life induced by huge volume change remain two great challenges. Herein, a multidimensional synergistic structure of few-layered Ti3C2 MXene/CoS2@N-doped porous carbon (f-Ti3C2/CoS2@NPC) is rationally designed as SIBs anodes, where N-doped porous carbon matrix-encapsulated ultrafine CoS2 nanoparticles are anchored on few-layered Ti3C2 MXene via TiOC bonds. The synergistic effects among each component greatly inhibit the aggregation of CoS2 nanoparticles (CoS2 NPs), readily build a long-range electron/Na+ conductive network and effectively provide a dual protection effect on CoS2 NPs during sodiation/desodiation process. Consequently, the f-Ti3C2/CoS2@NPC anode delivers a high-rate performance (282.6 mAh g−1 at 10 A g−1) and superior cyclability (200.6 mAh g−1 at 2 A g−1 after 1500 cycles). Furthermore, Na3V2(PO4)3//f-Ti3C2/CoS2@NPC full cells can release a high reversible capacity and good cyclability (325.8 mAh g−1 at 200 mA g−1 after 50 cycles), demonstrating great potential in practical application. This work further broadens the scope of multidimensional synergistic architectures and may inspires more research on MXene-based multidimensional structure for high-performance SIBs.
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