Search

Cascade reactions take advantage of step-saving and facile operation for obtaining chemicals. Herein, catalytic hydrogenation of nitroarene coupled condensation with β-diketone to afford β-ketoenamines is achieved by an integrated nanocatalyst, Pd-e@UiO-66. The catalyst has the structure of an acid-rich metal-organic framework (MOF), UiO-66-encapsulated electron-rich Pd nanoparticles, and it reconciles the electron-effect contradiction of cascade catalytic reactions: catalytic hydrogenation requires an electron-rich catalyst, while condensation requires electron-deficient Lewis acid sites. The catalyst showed good activity, high chemoselectivity, and universal applicability for the synthesis of β-ketoenamines using nitroarenes. More than 30 β-ketoenamines have been successfully prepared with up to 99% yield via the methodology of relay catalysis. The catalyst exhibited excellent stability to maintain its catalytic performance for more than five cycles. Furthermore, we conducted an in-depth exploration of the reaction mechanism with theoretical calculations.

2 nm Sb2S3 particles embedded in a mesoporous carbon framework by an adsorption method to construct a high performance anode material.

The treatment of mercury pollutants in water has been wide concern. Adsorption is a promising method for mercury removal that has been extensively studied. Nevertheless, the secondary application of the immobilized Hg is seldom investigated. In this paper, the Hg adsorption behavior of UiO-66 bearing sulfhydryl groups is studied. The research shows that the porous structure and sulfhydryl groups of UiO-66-SH can effectively promote the removal of mercury from water. In addition, this work also pushes forward the sequential application of the recovered adsorbent, which contains the adsorbed mercury that may cause secondary pollution. The recovered waste adsorbent, UiO-66-S-Hg, was successfully used as an efficient catalyst for transfer vinylation, which produces value-added products, vinyl benzoates. Eight vinyl esters have been successfully synthesized with a yield of up to 89%. This methodology provides a promising way for not only the treatment of mercury contamination, but also secondary pollution protection and the resource utilization of immobilized Hg.

The self-growing bell-shaped structure of the nickel foam substrate have excellent binding ability with the NF substrate, which greatly improve the mass and charge transfer efficiency and provide the possibility of stabilizing the catalyst at large currents.

Emerging classes of flexible electronic sensors as alternatives to conventional rigid sensors offer a powerful set of capabilities for detecting and quantifying physiological and physical signals from human skin in personal healthcare. Unfortunately, the practical applications and commercialization of flexible sensors are generally limited by certain unsatisfactory aspects of their performance, such as biocompatibility, low sensing range, power supply, or single sensory function. This review intends to provide up-to-date literature on wearable devices for smart healthcare. A systematic review is provided, from sensors based on nanomaterials and nanostructures, algorithms, to multifunctional integrated devices with stretchability, self-powered performance, and biocompatibility. Typical electromechanical sensors are investigated with a specific focus on the strategies for constructing high-performance sensors based on nanomaterials and nanostructures. Then, the review emphasizes the importance of tailoring the fabrication techniques in order to improve stretchability, biocompatibility, and self-powered performance. The construction of wearable devices with high integration, high performance, and multi-functionalization for multiparameter healthcare is discussed in depth. Integrating wearable devices with appropriate machine learning algorithms is summarized. After interpretation of the algorithms, intelligent predictions are produced to give instructions or predictions for smart implementations. It is desired that this review will offer guidance for future excellence in flexible wearable sensing technologies and provide insight into commercial wearable sensors.

1) Background Hollow nanostructures have gained great attention due to their excellent performance and wide range of applications. In this paper, a hollow nanoreactant is fabricated for investigating the chemisorption of antimony in water. 2) Methods We constructed the hierarchical LDH grown on hollow carbon spheres via the in-situ etching-growth from MOF precursor. The synthesized nanoreactant was evaluated with the adsorption of Sb, which shows ultra-smooth kinetics curves at various conditions, including five different initial concentrations and three different temperatures. Combining the characterizations of XPS, FT-IR and the results of adsorption, the chemisorption of antimony was illustrated that the inner-sphere complexation, hydrogen bonding and dehydration, as well as redox reaction may play important roles in the immobilization process of antimony. 3) Significant Findings This material exhibits a steady interaction between the adsorbent and antimony species, which suggests the dominant chemisorption procedure. In addition, the as prepared HCSs@Mn/Co-LDH has high adsorption capacities, especially at low antimony concentrations. The excellent performance is benefited by the construction of the hollow structure and the synergistic interaction between the components of the composite.

Devising an electrocatalyst with brilliant efficiency and satisfactory durability for hydrogen production is of considerable demand, especially for large-scale application. Herein, we adopt a multi-step consequential induced strategy to construct a bifunctional electrocatalyst for the overall water splitting. Graphene oxide (GO) was used as a carbon matrix and in situ oxygen source, which was supported by the octahedral PtNi alloy to form the PtxNiy-GO precursor. When calcinating in Ar atmosphere, the oxygen in GO induced the surface segregation of Ni from the PtNi octahedron to form a core-shell structure of Ptx@Niy. Then, the surface-enriched Ni continuously induced the reformation of C in reduced graphene oxide (rGO) to enhance the degree of graphitization. This multi-step induction formed a nanocatalyst Ptx@Niy-rGO which has very high catalytic efficiency and stability. By optimizing the feeding ratio of PtNi (Pt:Ni = 1:2), the electrolytic overall water splitting at 10 mA·cm−2 can be driven by an electrolytic voltage of as low as 1.485 V, and hydrogen evolution reaction (HER) only needs an overpotential of 37 mV in 1.0 M KOH aqueous solution. Additionally, the catalyst exhibited consistent existence form in both HER and oxygen evolution reaction (OER), which was verified by switching the anode and cathode of the cell in the electrolysis of water. This work provides a new idea for the synthesis and evaluation of the bifunctional catalysts for water splitting.

Semi-hydrogenation usually requires an effective catalyst to ensure selectivity, especially when reducible groups coexist in a molecule. Pd is widely used in the semi-hydrogenation of alkynes to synthesize alkenes, but the selectivity control is still challenging. Herein, we design a catalyst with a semi-encapsulated PdRh alloy heterojunction in a carbon layer for the selective semi-hydrogenation of 3-nitrophenylacetylene (3-NPA). Benefiting from the presence of a PdRh alloy heterojunction and a semi-encapsulated structure, the catalyst delivers good selectivity and maintains high activity. In addition, the carbon shell can ensure the stability of the catalyst and prolong the service life. This study provides ideas for the rational design of a catalyst to achieve a selective hydrogenation reaction for practical applications.

Synthesis of regular morphology catalysts with self-growing substrates is one of the effective methods to solve the problem of easy shedding of heterogeneous catalysts. In this study, Fe-doped Ni

Oxidative stress is associated with many acute and chronic inflammatory diseases. Development of nanomaterial-based enzyme mimetics for reactive oxygen species (ROS) scavenging is challenging, but holds great promise for the treatment of inflammatory diseases. Herein, we report the highly ordered manganese dioxide encapsulated selenium-melanin (Se@Me@MnO2) nanozyme with high efficiency for intracellular antioxidation and anti-inflammation. The Se@Me@MnO2 nanozyme is sequentially fabricated through the radical polymerization and the in-situ oxidation-reduction. In vitro experimental results demonstrated that the Se@Me@MnO2 nanozyme exhibits multiple enzyme activities to scavenge ROS, including catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD). Mechanism researches illustrated that the Se core possesses GPx-like catalytic activity, the Me and the MnO2 possess both the SOD-like and the CAT-like activities. What’s more, due to the stable unpaired electrons existing in the nanozyme, the Se, Me and MnO2 provide synergistic and fast electron transfer effect to achieve the quickly scavenging of hydrogen peroxide, hydroxyl radical, and superoxide anion. Further in vivo experimental results showed that this biocompatible nanozyme exhibits cytoprotective effects by resisting ROS-mediated damage, thereby alleviating the inflammation. This multienzyme mimetics is believed to be an excellent ROS scavenger and have a good potential in clinical therapy for ROS-related diseases.

Hydrogenation of nitriles is an efficient and environmentally friendly route to synthesize symmetrical secondary amines, but it usually produces a mixture of amines, imines, and hydrogenolysis by-products. Herein we report a magnetic quaternary-component Pt-CuFe/Fe3 O4 nanocatalyst system for the selective synthesis of symmetrical secondary amines with ammonia borane as hydrogen donor. The catalyst with a low Pt loading (0.456 wt%) is the source of the activity, and the d-band electron transfer from Cu to Fe enhances the selectivity. This synergistic effect results in the transformation of benzonitrile to dibenzylamine with excellent conversion (up to 99 %) and nearly quantitative selectivity (up to 96 %) under mild reaction conditions, nevertheless, the reaction TOF is as high as up to 1409.9 h-1 . A variety of nitriles are suitable for the synthesis of symmetrical secondary amines. More importantly, unwanted hydrogenolysis byproducts, especially toluene, is not detected at all. In addition, the catalyst is magnetically recoverable, and it can be reused up to five times.

Due to the complexity of the contaminations in wastewater, a universal adsorbent that takes many sorts of pollutant is desired. A multi-functioning magnetic Fe3O4-cored magnesium-aluminum layered double oxide (Fe3O4@LDO) composite was prepared and employed as an adsorbent for removing F−, Sb(III) and MO from water, respectively, which are three typical contaminants with different molecule sizes as water contamination. The effect of pH contact time and initial concentrations of pollutants on the removal rates of each contaminant were investigated. Fe3O4@LDO composite showed excellent adsorption performance for all of the three molecules F−, Sb(III) and MO, and their maximum adsorption capacities are as high as 258, 391, and 506mg/g, respectively. The adsorption process of F−, Sb(III) and MO on Fe3O4@LDO fitted well to Langmuir model and pseudo-second-order kinetic model. The adsorption mechanisms of F−, Sb(III) and MO on Fe3O4@LDO were investigated. We discovered that iron ions diffused from Fe3O4 nanospheres contributed to the good performance of the absorbent.

Fabrication of functional electrochemical biosensor is a hot topic; however, precise and sensitive cancer detection in early clinical diagnosis is still a great challenge. Continuous efforts have been devoted to explore functional materials for this issue. In this work, we developed a dual binding sites and dual signal-amplifying electrochemical aptasensor of self-polymerized dopamine-decorated Au and coordinated with Fe-MOF (Au@PDA@Fe-MOF) for the detection of carcinoembryonic antigen (CEA). Remarkably, Au@PDA@Fe-MOF features high sensitivity, multiple active sites, good biocompatibility, and excellent selectivity, which is attributed to abundant -COOH in porous Fe-MOF and unsaturated Fe3+ sites on the surface of Fe-MOF as the active binding sites grafting more NH2-functionalized CEA-specific aptamer and redox PDA and Fe-MOF accelerating the movement of electrons for dual signal amplifying. Meanwhile, the electrochemical aptasensor shows favorable repeatability with 1.82% relative standard deviation (RSD) under five independent aptasensors and strong stability with only 3.3% degradation after 12 days of storage. In addition, the aptasensor has wide CEA detection range from 1 fg mL-1 to 1 μg mL-1 with a low detection limit of 0.33 fg mL-1 (S/N = 3). Furthermore, the aptasensor is feasible for accurate and quantitative detection of CEA in serum samples with RSD below 2.32%. The satisfying results demonstrate promising applications of the CEA aptasensor in practical sample analysis and lay an important foundation for other biomarker detection in early clinical diagnosis.

Over the past few decades, people with epilepsy were advised not to engage in sports based on the fear that sporting activity may cause injuries, potentially induce seizures, and have a negative effect on disease course. However, in recent years, numerous studies have indicated a positive role of physical exercise in reducing the frequency of seizures and improving health condition of patients with epilepsy. The purpose of this study was to compare the effects of different physical exercise programs on the symptomatology and health condition of individuals with epilepsy and provide guidance for selecting the optimal modality of physical exercise for patients with epilepsy via a meta-analysis of available literature.A literature search was carried out in MEDLINE via PubMed, Cochrane Library, EBSCO, Embase, China National Knowledge (CNKI), and Wan fang databases to gather relevant data about different physical exercise modalities and epilepsy. We will use Endnote X9 software for studies selection and Stata16.0 software for the data analysis.This present study aimed to provide the most up to date evidence and recommendations for clinicians and epilepsy patients to choose an optimal type of exercise.Aerobic exercise and resistance exercises both had a positive effect on epilepsy patients. Persons with epilepsy should be encouraged to participate in sports activities.INPLASY registration number: INPLASY202220070.

In recent years, the removal of antimony(III) (Sb(III)) contaminant from water has caused widespread concern. Herein, two adsorbents have been successfully developed to remove Sb(III) from water and systemically characterized. One is the composite of magnetic mesoporous carbon nanospheres (Fe3O4@CNs) with Fe2O3 particles that is represented as Fe3O4@Fe2O3@CNs, and the other one is mesoporous carbon nanosphere-accommodated Fe2O3 particles noted as Fe2O3@CNs. Both adsorbents have the advantages of magnetic separation and high Sb(III) removal capacity. The adsorption properties of Sb(III) on both adsorbents were studied by the experiments of adsorption isotherms and kinetics. The results show that the adsorption behaviors on both adsorbents follow the Langmuir isotherm model and pseudo-second-order kinetic model. The maximum Sb(III) adsorption capacity of Fe3O4@Fe2O3@CNs and Fe2O3@CNs is 234.28 and 102.84 mg/g, respectively. The high capacity can be attributed to the adsorption-active Fe2O3 particles that ar...

Carbon materials derived from metal-organic frameworks have attracted increasing attention as anodes for energy storage. In this study, Fe, Ni-doped ZIF-8 is carbonized at high temperature to obtain bimetallic Fe and Ni modified tension -relaxed carbon (FeNi@trC). Fe and Ni have opposite structural modification effects when the metal ions are doped into the ZIF-8 dodecahedron. The obtained carbon material maintains the regular dodecahedron morphology, which means the relaxation of tension and strong thermal stability during annealing. Moreover, the presence of nickel enhances the carbonization degree and electrochemical stability of FeNi@trC, while the calcination of the tensive ZIF-8 precursor offers more defect sites. The discharge capacities of FeNi@trC materials are stable at 182.9 mAh·g−1 and 567.9 mAh·g−1 for sodium-ion batterie (SIB) and lithium-ion batterie (LIB) at 0.05 A·g−1. Compared with the current density of 0.05 A·g−1, the discharge capacity of SIB and LIB attenuates by 29.4% and 55.9% at 1 A·g−1, respectively, and the FeNi@trC shows good performance stability in the following cycles.

Background Although depression is the leading cause of disability worldwide, its pathophysiology is poorly understood. Our previous study showed that hippocampal peroxisome proliferator-activated receptor δ (PPARδ) overexpression displays antidepressive effect and enhances hippocampal neurogenesis during chronic stress. Herein, we further extended our curiosity to investigate whether downregulating PPARδ could cause depressive-like behaviors through downregulation of neurogenesis. Methods Stereotaxic injection of lentiviral vector, expressing short hairpin RNA complementary to the coding exon of PPARδ, was done into the bilateral dentate gyri of the hippocampus, and the depression-like behaviors were observed in mice. Additionally, hippocampal neurogenesis, brain-derived neurotrophic factor and cAMP response element-binding protein were measured both in vivo and in vitro. Results Hippocampal PPARδ knockdown caused depressive-like behaviors and significantly decreased neurogenesis, neuronal differentiation, levels of mature brain-derived neurotrophic factor and phosphorylated cAMP response element-binding protein in the hippocampus. In vitro study further confirmed that PPARδ knockdown could inhibit proliferation and differentiation of neural stem cells. Furthermore, these effects were mimicked by repeated systemic administration of a PPARδ antagonist, GSK0660 (1 or 3 mg/kg i.p. for 21 d). Conclusions These findings suggest that downregulation of hippocampal PPARδ is associated with depressive behaviors in mice through an inhibitory effect on cAMP response element-binding protein/brain-derived neurotrophic factor-mediated adult neurogenesis in the hippocampus, providing new insights into the pathogenesis of depression.

To indicate health status of bridges and help stakeholders make decision on maintenance, a comprehensive framework has been proposed to evaluate structural efficiency of suspension bridges using an...

Hydrogenation of nitriles to afford amines under mild conditions is a challenging task with an inexpensive heterogeneous catalyst, and it is even more difficult to obtain primary amines selectively because of the accompanying self-coupling side reactions. An efficient catalytic system was designed as Fe3O4@nSiO2–NH2–RhCu@mSiO2 to prepare primary amines through the transfer hydrogenation of nitrile compounds with economical HCOOH as the hydrogen donor. The loading of rhodium in the catalyst could be at the ppm level, and the TOF reaches 6803 h−1 for Rh. This catalytic system has a wide substrate range including some nitriles that could not proceed in the previous literature. The experimental results demonstrate that the excellent selectivity for primary amines is guaranteed by three tactics, which are the strong active site, the inhibition of side products by the hydrogen source and the special pore structure of the catalyst. In addition, the catalyst could be reused ten times without activity loss through convenient magnetic recovery.

A magnetically separable 2D Rh/Fe3O4/g-C3N4-N catalyst has been synthesized for the catalytic transfer hydrogenation of nitroarenes to afford corresponding anilines. The highly dispersed Rh nanoparticles are the dominant active species. The reaction is second order for rhodium according to the kinetic study, and this means the activity of different Rh-containing catalyst can be precisely predicted and the active site contains two adjoining rhodium atoms. The strong interaction between Rh and Fe3O4 contributes to the catalytic performance, therefore the obtained Rh/Fe3O4/g-C3N4-N catalyst exhibits excellent catalytic activity and chemoselectivity for the reduction of various nitroaromatics, and the turnover frequencies (TOF) can reach as high as 12,666 h−1 for 4-nitrophenol. Moreover, this catalytic system is environmentally friendly because of its green solvent water and harmless byproducts (H2O and N2), and the catalyst shows outstanding stability and recyclability with at least 12 cycles.

Core–shell nanocomposites with a catalytic metal-organic framework (MOF) shell are more effective and stable than bare MOF. We have successfully designed an effective heterogeneous catalyst for the synthesis of benzimidazole by integrating acidic catalytic activity, and promoted the aerobic oxidation and magnetic recyclability of core–shell nanocomposite Fe3O4@SiO2@UiO-66. The Fe3O4@SiO2 core is encapsulated by the in situ-grown UiO-66 shell, and the UiO-66 shell retains the porous structure and crystallinity of UiO-66 with abundant exposed Lewis acid sites. It shows high catalytic ability for the synthesis of various benzimidazoles through the acid-catalyzed condensation and aerobic oxidation with in situ oxygen. The Fe3O4@SiO2 core provides magnetic recyclability of Fe3O4@SiO2@UiO-66, and maintains high catalytic ability and stability over six cycles.

The application of antimony containing compounds in the industry has generated considerable antimony contaminants, which requires to develop methods that are as efficient as possible to remove antimony from water in the view of human health. The adsorption is among the most high-efficiency and reliable purification methods for hazardous materials due to the simple operation, convenient recycling and low cost. Herein, this review systematically summarizes the functional materials that are used to adsorb antimony from water, including metal (oxides) based materials, carbon-based materials, MOFs and molecular sieves, layered double hydroxides, natural materials, and organic-inorganic hybrids. The iron-based adsorbents stand out among these adsorbents because of their excellent performance. Moreover, the interaction between antimony and different functional materials is discussed in detail, while the inner-sphere complexation, hydrogen bond as well as ligand exchange are the main impetus during antimony adsorption. In addition, the desorption methods in adsorbents recycling are also comprehensively summarized. Furthermore, we propose an adsorption capacity balanced evaluation function (ABEF) based on the reported results to evaluate the performance of the antimony adsorption materials for both Sb(III) and Sb(V), as antimony usually has two valence forms of Sb(III) and Sb(V) in wastewater. Another original insight in this review is that we put forward a potential application prospect for the antimony-containing waste adsorbents. The feasible future development includes the utilization of the recycled antimony-containing waste adsorbents in catalysis and energy storage, and this will provide a green and sustainable pathway for both antimony removal and resourization.

Actuated by the non-ionic heavy metal of antimony (Sb) contaminants with undesired toxicity to the environment and human health, capturing Sb is urgent to remedy contaminated water. Herein, the lamellar MnCo hydrotalcite was grown on catkin-derived biochar through the in situ etching of ZIF-L to construct a hierarchical microtube@nanosheet hybrid (CLMH) for Sb immobilization. The adsorption behaviour and mechanism of trivalent antimony (Sb (III)) on the CLMH were investigated. The CLMH shows good pH applicability for capturing Sb(III) at pH from 2 to 9. The excellent adsorption capacity of CLMH for Sb(III) is 247.62 mg g−1 at 303 K, and the endothermic process is proved by the positive value of Δ H 0 (10.54 kJ mol−1). The adsorption process is fitted with the intra-particle diffusion model, which can be described with external mass transfer, intraparticle diffusion in pores, and equilibrium stage. The adsorption mechanism is proved, which includes the bind of Metal–O–Sb bonds by inner-sphere complex, the embedding of Sb in the intercalation of hydrotalcite, redox between Mn and Sb, and functional groups dependent anchoring effect. The work benefits the understanding of the antimony removal behaviour over the hierarchical microtube@nanosheet hybrids.

The intercrystalline interfaces have been proven vital in heterostructure catalysts. However, it is still challenging to generate specified heterointerfaces and to make clear the mechanism of a reaction on the interface. Herein, this work proposes a strategy of Fe-catalyzed cascade formation of heterointerfaces for comprehending the hydrogen evolution reaction (HER). In the pure solid-phase reaction system, Fe catalyzes the in situ conversion of MoO