•Component-structure-defined carbon nanocages embedded Co/CoxP (Co/CoxP/HNC) are synthesized•The performance-dependence on shell-thickness and doped-P-content are revealed.•Co/CoxP/HNC-5 exhibits ...outstanding electrocatalytic activity for ORR and OER.•Zn-air battery based on Co/CoxP/HNC-5 shows excellent charge/discharge stability.
The design and synthesis of composite-structure-defined bifunctional oxygen reduction and evolution reactions electrocatalysts for rechargeable Zn-air batteries are highly important. Herein, a facile surface functionalization-carbonization-phosphidation strategy is proposed to construct a novel composition-structure-controllable nanomaterial from a zeolite imidazole ester framework (ZIF67), which has been applied in oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and Zn-air batteries. In the typical nanomaterial, Co and CoxP (a mixture of Co2P and CoP) were embedded in hollow N-doped carbon shell (Co/CoxP/HNC-5). The relationship between the activity and shell thicknesses of the carbonization products of ZIF67 coated with different mass ratios of polydopamine has been studied. In addition, the doped P-content showed a significant impact on the bifunctional oxygen activity, especially for Co/CoxP/HNC-5. Benefiting from the unique structure, multiple compositions, and synergistic effects, the superior bifunctional oxygen electrocatalytic activity (ΔE = 0.667 V) were obtained on Co/CoxP/HNC-5. Furthermore, Co/CoxP/HNC-5 served as an air-cathode catalyst and exhibited remarkable peak power density, specific capacity and durability in a practical Zn-air battery. This work provides a strategy for the construction of efficient bifunctional electrocatalysts with special structure and adjustable compositions.
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•PtCuFe nanochains (NCs) are synthesized by a convenient solvothermal method.•Cu2+ plays an important role in the formation of 1D NCs.•The composition-performance relationship of ...PtCuxFey NCs is revealed.•The PtCuFe NCs show excellent activity and durability toward MOR and HER.
The controllable synthesis of 1-dimensional (1D) multi-metal Pt-based alloys, with enhanced electro-chemical properties remains a challenge, despite the wide application of Pt-based catalysts in fuel cells and in the hydrogen evolution reaction (HER). Herein, we fabricate PtCuFe alloy nanochains (NCs) that have a tunable composition by flexibly adjusting the molar ratios of the metal precursors. It was found that Cu2+ is key in the formation of 1D NCs, as confirmed by transmission electron microscopy characterizations. In addition, the alloyed Fe can further increase the content of the metallic state of Cu in the PtCuFe NCs. The as-prepared PtCuFe NCs exhibited higher catalytic activity and stability than those of the Pt nanoparticles (NPs), PtFe NPs, and PtCu NCs, for the methanol oxidation reaction (MOR) and HER. Additionally, the composition-performance relationship of PtCuxFey NCs toward the MOR and HER were investigated. The hybrid density functional theory calculation and analysis showed that the 1D PtCuFe NCs have a lower lowest unoccupied molecular orbital (LUMO) than those of the 2- and 3-dimensional PtCuFe, verifying that the 1D PtCuFe NCs exhibit the highest activity for the MOR. This work has established a new method for the controllable synthesis of multi-metal Pt-based NCs/alloy catalysts and their subsequent applications in other electro-catalytic reactions.
A conductive and biocompatible hybrid hydrogel was successfully assembled into an adhesive, flexible wearable sensor for ultra-sensitive human-computer interaction and smart detection, which holds ...excellent self-healing capability. This conductive, repairable and biocompatible hybrid network hydrogel is formed by dynamic supramolecular cross-linking of an MXene, PEDOT:PSS, polyvinyl alcohol and polydopamine. It uses conductively a functionalized MXene (titanium carbide) and PEDOT:PSS as the conductive network. The PVA-MXene-PEDOT:PSS-PDA organic hydrogel has an excellent ability to repair itself (within 1.8 s) and can be assembled into repairable, sticky, and soft intelligent sensors, which can accurately detect various human movements (including bending of fingers and wrists, gesture recognition, winking and expression changes). In addition, it can be assembled into a smart sensor for speed recognition and handwriting recognition. Due to the addition of PVA, the conductive hydrogel has good biocompatibility. Therefore, it can be installed on prostheses to realize the touch screen function and solve the problem of difficulty in controlling the screen using silicone prostheses, indicating that it has a huge application prospect in the field of bionic intelligent robots. Thus, stretchable and flexible hydrogel electronic sensors have great potential for human motion detection and smart detection due to their excellent self-healing capability, adhesive properties and wearability.
This paper reports the excellent properties and multifunctional applications of a fast self-healing polyvinyl alcohol nano-organic composite hydrogel.
Recently, increasing evidence has suggested the association between gut dysbiosis and Alzheimer's disease (AD) progression, yet the role of gut microbiota in AD pathogenesis remains obscure. Herein, ...we provide a potential mechanistic link between gut microbiota dysbiosis and neuroinflammation in AD progression. Using AD mouse models, we discovered that, during AD progression, the alteration of gut microbiota composition leads to the peripheral accumulation of phenylalanine and isoleucine, which stimulates the differentiation and proliferation of pro-inflammatory T helper 1 (Th1) cells. The brain-infiltrated peripheral Th1 immune cells are associated with the M1 microglia activation, contributing to AD-associated neuroinflammation. Importantly, the elevation of phenylalanine and isoleucine concentrations and the increase of Th1 cell frequency in the blood were also observed in two small independent cohorts of patients with mild cognitive impairment (MCI) due to AD. Furthermore, GV-971, a sodium oligomannate that has demonstrated solid and consistent cognition improvement in a phase 3 clinical trial in China, suppresses gut dysbiosis and the associated phenylalanine/isoleucine accumulation, harnesses neuroinflammation and reverses the cognition impairment. Together, our findings highlight the role of gut dysbiosis-promoted neuroinflammation in AD progression and suggest a novel strategy for AD therapy by remodelling the gut microbiota.
Surgical resection and endoscopic resection comprise two alternative options for the treatment of submucosal tumors (SMTs) originating from the muscularis propria (MP) layer. Endoscopic resection is ...minimally invasive compared with surgical resection. Conventional non-tunneling techniques, such as endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), and endoscopic full-thickness resection (EFR) have been demonstrated to be safe and effective. However, these techniques fail to maintain the integrity of the mucosa and induce high risk of perforation, infection, and postoperative strictures. Submucosal tunneling endoscopic resection (STER) is a novel surgical technique that can maintain the integrity of the mucosa by establishing a tunnel between the submucosal and the MP layers. STER has been proven to be effective and safe for the treatment of SMTs. Currently, STER has become a standard treatment for gastrointestinal (GI) SMTs originating from the MP layer, notably in China. In the present review, we describe the indications, procedures, postoperative care, efficacy and safety outcomes, and future perspectives of STER for GI SMTs originating from the MP layer.
Background Accumulating evidence supports that lysine-specific demethylase 5 (KDM5) family members act as oncogenic drivers. This study was performed to elucidate the potential effects of KDM5A on ...prostate cancer (PCa) progression via the miR-495/YTHDF2/m6A-MOB3B axis. Methods The expression of KDM5A, miR-495, YTHDF2 and MOB3B was validated in human PCa tissues and cell lines. Ectopic expression and knockdown experiments were developed in PCa cells to evaluate their effects on PCa cell proliferation, migration, invasion and apoptosis. Mechanistic insights into the interaction among KDM5A, miR-495, YTHDF2 and MOB3B were obtained after dual luciferase reporter, ChIP, and PAR-CLIP assays. Me-RIP assay was used to determine m6A modification level of MOB3B mRNA in PCa cells. Mouse xenograft models of PCa cells were also established to monitor the tumor growth. Results KDM5A was highly expressed in human PCa tissues and cell lines. Upregulated KDM5A stimulated PCa cell proliferation, migration and invasion, but reduced cell apoptosis. Mechanistically, KDM5A, as a H3K4me3 demethylase, bound to the miR-495 promoter, which led to inhibition of its transcription and expression. As a target of miR-495, YTHDF2 could inhibit MOB3B expression by recognizing m6A modification of MOB3B mRNA and inducing mRNA degradation. Furthermore, KDM5A was found to downregulate MOB3B expression, consequently augmenting PCa cell proliferation, migration and invasion in vitro and promoting tumor growth in vivo via the miR-495/YTHDF2 axis. Conclusion In summary, our study highlights the potential of histone demethylase KDM5A activity in enhancing PCa progression, and suggests KDM5A as a promising target for PCa treatment. Keywords: KDM5A, microRNA-145, YTHDF2, MOB3B, m6A modification, Prostate cancer, Migration, Invasion
Functionalization of amines by using CO2 is of fundamental importance considering the abundance of amines and CO2. In this context, the catalytic formylation and methylation of amines represent ...convenient and successful protocols for selective CO2 utilization as a C1 building block. This study represents the first example of selective catalytic double N‐formylation of aryl amines by using a dinuclear Mn complex in the presence of phenylsilane. This robust system also allows for selective formylation and methylation of amines under a range of conditions.
A formyl occasion: Selective catalytic double N‐formylation of aryl amines is accomplished by using a dinuclear manganese complex in the presence of phenylsilane. This robust system also allows for selective formylation and methylation of amines under a range of conditions.
Silver(i) chalcogenide/chalcogenolate clusters are promising photofunctional materials for sensing, optoelectronics and solar energy harvesting applications. However, their instability and poor ...room-temperature luminescent quantum yields have hampered more extensive study. Here, we graft such clusters to adaptable bridging ligands, enabling their interconnection and the formation of rigid metal-organic frameworks. By controlling the spatial separation and orientation of the clusters, they then exhibit enhanced stability (over one year) and quantum yield (12.1%). Ultrafast dual-function fluorescence switching (<1 s) is also achieved, with turn-off triggered by O
and multicoloured turn-on by volatile organic compounds. Single-crystal X-ray diffraction of the inclusion materials, obtained by single-crystal-to-single-crystal transformation, enables precise determination of the position of the small molecules within the framework, elucidating the switching mechanism. The work enriches the cluster-based metal-organic framework portfolio, bridges the gap between silver chalcogenide/chalcogenolate clusters and metal-organic frameworks, and provides a foundation for further development of functional silver-cluster-based materials.
It is highly challenging to activate the basal plane and minimize the π−π stacking of MoS2 sheets, thus enhancing its catalytic performance. Here, we display an approach for making well‐dispersed ...MoS2. By using the N‐doped multi‐walled carbon nanotubes (NMWCNTs) as an isolation unit, the aggregation of MoS2 sheets was effectively reduced, favoring the dispersion of Pt nanoparticles (noted as Pt/NMWCNTs‐isolated‐MoS2). Excellent bifunctional catalytic performance for methanol oxidation and oxygen reduction reaction (MOR/ORR) were demonstrated by the produced Pt/NMWCNTs‐isolated‐MoS2. In comparison to Pt nanoparticles supported on MoS2 (Pt/MoS2), the MOR activity (2314.14 mA mgpt−1) and stability (317.69 mA mgpt−1 after 2 h of operation) on Pt/NMWCNTs‐isolatedMoS2 were 24 and 232 times higher, respectively. As for ORR, Pt/NMWCNTs‐isolated‐MoS2 holds large half‐wave potential (0.88 V) and high stability (92.71 % after 22 h of operation). This work presents a tactic for activating the basal planes and reducing the π−π stacking of 2D materials to satisfy their applications in electrocatalysis. In addition, the proposed sheet‐isolation method can be used for fabricating other 2D materials to promote the dispersion of nanoparticles, which assist its application in other fields of energy as well as the environment.
The isolation of NMWCNTs weakens the π−π stacking, improves the conductivity, and activates basal planes of the MoS2 sheets. Consequently, the prepared Pt/NWMCNTs‐solated‐MoS2 realizes excellent bifunctional catalytic performance for MOR and ORR.
An efficient method has been developed for the reductive amination of CO2 by using readily available and recyclable oxofluorovanadates as catalysts. Various amines are transformed into the desired ...N‐formylated products in moderate to excellent yields at room temperature in the presence of phenylsilane. Mechanistic studies based on in situ infrared spectroscopy suggest a reaction pathway initiated through F−Si interactions. The activated phenylsilane allows for CO2 insertion to produce phenylsilyl formate, which undergoes attack by the amine to generate the target product.
Achievements in amination: Metal oxofluorovanadates, such as K2VOF4, are found to be efficient catalysts for the reductive amination of carbon dioxide. The heterogeneous catalysts can be recycled by simple centrifugation and reused for four cycles without loss of activity.
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