Axially Coordinated Gold Nanoclusters Tailoring Fe-N-C Nanozymes for Enhanced Oxidase-Like Specificity and Activity.

Metal-organic frameworks (MOF) derived nitrogen-doped carbon-supported monodisperse Fe (Fe-N-C) catalysts are intensively studied, but great challenges remain in understanding the relationship between the coordination structure and the performance of Fe-N-C nanozymes. Herein, a novel nanocluster ligand-bridging strategy is proposed for constructing Fe-S1 N4 structures with axially coordinated S and Au nanoclusters on ZIF-8 derived Fe-N-C (labeled Aux /Fe-S1 N4 -C). The axial Au nanoclusters facilitate electron transfer to Fe active sites, utilizing the bridging ligand S as a medium, thereby enhancing the oxygen adsorption capacity of composite nanozymes. Compared to Fe-N-C, Aux /Fe-S1 N4 -C exhibits high oxidase-like specificity and activity, and holds great potential for detecting acetylcholinesterase activity with a detection limit of 5.1 µU mL-1 , surpassing most reported nanozymes.

Double joystick technique - a modified method facilitates operation of Gartlend type-â ¢ supracondylar humeral fractures in children.

Gartland type-Ⅲ supracondylar humerus fracture (SCHF) is a severe lesion with the feature of difficult reduction. Due to the high failure rate of traditional reduction, a more practical and safer method is needed. This retrospective study aimed to explore the effectiveness of the double joystick technique during the closed reduction of children with type-III fractures. Forty-one children with Gartland type-Ⅲ SCHF underwent closed reduction and percutaneous fixation using the double joystick technique at our hospital between June 2020 and June 2022, and 36 (87.80%) patients were successfully followed up. The affected elbow was evaluated by the joint motion, radiographs, and Flynn's criteria then contrasted with the contralateral elbow at the last follow-up. A group of 29 boys and seven girls with an average age of 6.33 ±â€…2.68 years. The mean time of surgery and hospital stay was 26.61 ±â€…7.51 min and 4.64 ±â€…1.23 days, respectively. After a mean follow-up of 12.85 months, the average Baumann angle was 73.43 ±â€…3.78°, although the average carrying angle (11.33 ±â€…2.17°), flexion angle (143.03 ±â€…5.15°), and extension angle (0.89 ±â€…3.23°) of the affected elbow were less than those of the contralateral elbow ( P  < 0.05), the mean range of motion difference between two sides is only 3.39 ±â€…1.59°, with no complications. Furthermore, 100% of patients recovered satisfactorily, with excellent outcomes (91.67%) and good outcomes (8.33%). The double joystick technique is a safe and effective method that facilitates the closed reduction of Gartland type-Ⅲ SCHF in children without raising the risk of complications.

Analyzing Prognostic Hub Genes in the Microenvironment of Cutaneous Melanoma by Computer Integrated Bioinformatics.

Cutaneous melanoma (CM) is attracting increasing attention due to high mortality. In response to this, we synthetically analyze the CM dataset from the TCGA database and explore microenvironment-related genes that effectively predict patient prognosis. Immune/stromal scores of cases are calculated using the ESTIMATE algorithm and are significantly associated with overall patient survival. Then, differentially expressed genes are identified by comparing the immune score and stromal score, also prognostic genes are subsequently screened. Functional analysis shows that these genes are enriched in different activities of immune system. Moreover, 19 prognosis-related hub genes are extracted from the protein-protein interaction network, of which four unreported genes (IL7R, FLT3, C1QC, and HLA-DRB5) are chosen for validation. A significant negative relationship is found between the expression levels of the 4 genes and pathological stages, notably T grade. Furthermore, the K-M plots and TIMER results show that these genes have favorable value for CM prognosis. In conclusion, these results give a novel insight into CM and identify IL7R, FLT3, C1QC, and HLA-DRB5 as crucial roles for the diagnosis and treatment of CM.

Platinum-Tin/Tin Oxide/CNT Catalysts for High-Performance Electrocatalytic Ethanol Oxidation.

Ethanol is a promising liquid clean energy source in the energy conversion field. However, the self-poisoning caused by the strongly adsorbed reaction intermediates (typically, CO) is a critical problem in ethanol oxidation reaction. To address this issue, we proposed a joint use of two strategies, alloying of Pt with other metals and building Pt/metal-oxide interfaces, to achieve high-performance electrocatalytic ethanol oxidation. For this, a well-designed synthetic route combining wet impregnation with a two-step thermal treatment process was established to construct PtSn/SnOx interfaces on carbon nanotubes. Using this route, the alloying of Pt-Sn and formation of PtSn-SnOx interfaces can simultaneously be achieved, and the coverage of SnOx thin films on PtSn alloy nanoparticles can be facilely tuned by the strong interaction between Pt and SnOx . The results revealed that the partial coverage of SnOx species not only retained the active sites, but also enhanced the CO anti-poisoning ability of the catalyst. Consequently, the H-PtSn/SnOx /CNT-2 catalyst with an optimized PtSn-SnOx interface showed significantly improved performances toward the ethanol oxidation reaction (825 mA mgPt -1 ). This study provides deep insights into the structure-performance relationship of PtSn/metal oxide composite catalysts, which would be helpful for the future design and fabrication of high-performance Pt-based ethanol oxidation reaction catalysts.

Biomimetic Metal-Organic Framework Composite-Mediated Cascade Catalysis for Synergistic Bacteria Killing.

Encapsulating nanoparticles/biomolecules into metal-organic freamworks (MOFs) has proven to be highly effective in creating new functions during their applications. However, it is highly desirable yet remains challenging to achieve the synergy of specific functions between the MOF host and guest species. Herein, inspired by the natural multienzyme system, a novel MOF composite biomimetic structure based on the coencapsulation of glucose oxidase (GOx) and l-arginine (l-Arg) into Cu-MOFs (CuBDC) with Fenton-like catalytic activity is designed for achieving the synergistic antibacterial effect. Once activated by GOx-catalyzed glucose oxidation, a large amount of oxygen radicals, toxic ONOO-, and NO are rapidly produced over this well-designed l-Arg/GOx@CuBDC through a double-cascade reaction. Thanks to the synergy of highly reactive species, outstanding antibacterial effects (bacterial inactivation ≥97%) are observed at very low doses (38 µg mL-1 for Escherichia coli and 3.8 µg mL-1 for Staphylococcus aureus). In addition, the in vivo experiment in mice demonstrated that the as-prepared l-Arg/GOx@CuBDC has good biocompatibility, indicating its good potential in practical applications. Such a biomimetic multienzyme system proposes a new design idea for highly efficient antibiosis as well as even therapy for tumors.

The function of metal-organic frameworks in the application of MOF-based composites.

In the last two decades, metal-organic frameworks (MOFs), as a class of porous crystalline materials formed by organic linkers coordinated-metal ions, have attracted increasing attention due to their unique structures and wide applications. Compared to single components, various well-designed MOF-based composites combining MOFs with other functional materials, such as nanoparticles, quantum dots, natural enzymes and polymers with remarkably enhanced or novel properties have recently been reported. To efficiently and directionally synthesize high-performance MOF-based composites for specific applications, it is vital to understand the structural-functional relationships and role of MOFs. In this review, preparation methods of MOF-based composites are first summarized and then the relationship between the structure and performance is determined. The functions of MOFs in practical use are classified and discussed through various examples, which may help chemists to understand the structural-functional relationship in MOF-based composites from a new perspective.

Optimization of gold-palladium core-shell nanowires towards H2O2 reduction by adjusting shell thickness.

Designable bimetallic core-shell nanoparticles exhibit superb performance in many fields including industrial catalysis, energy conversion and chemical sensing, due to their outstanding properties associated with their tunable electronic structure. Herein, Au-Pd core-shell (AurichPd@AuPdrich) nanowires (NWs) were synthesized through a one-pot facile chemical reduction method in the presence of cetyltrimethyl ammonium bromide (CTAB) surfactant. The thickness of the Pd shell could be adjusted by directly controlling the Au/Pd feeding ratio while maintaining the nanowire morphology. The as-obtained Au75Pd25 core-shell NWs with a thin Pdrich shell showed significantly enhanced activities towards the reduction of hydrogen peroxide with the sensitivity reaching 338 µA cm-2 mM-1 and a linear range up to 10 mM. In sum, Pd shell thickness could be used to adjust the electronic structure, thereby optimizing the catalytic activity.

Correction: Robust electrochemical metal oxide deposition using an electrode with a superhydrophobic surface.

Correction for 'Robust electrochemical metal oxide deposition using an electrode with a superhydrophobic surface' by Jun Zhang, et al., Nanoscale, 2017, 9, 87-90.

Robust electrochemical metal oxide deposition using an electrode with a superhydrophobic surface.

Described herein is the first study of metal oxide deposition on an electrode with a solid/liquid/gas triphase reaction interface. Such an electrode enables the formation of a locally high interface pH value that is independent of the bulk conditions, and allows the deposition of a wide variety of metal oxides in a robust electrolyte. The results reveal that the control of electrode surface wettability is of significant importance for the regulation of the electrode-electrolyte local interface environment, which provides a new set of guidelines and perspective for future electrode preparation and application.

High performance Cu/Cu2O nanohybrid electrocatalyst for nonenzymatic glucose detection.

Here we report Cu/Cu2O nanocomposites prepared via potential oscillation. High resolution transmission electron microscopy images reveal a homogeneous distribution of Cu and Cu2O in the composite. Due to the synergistic effect between Cu and Cu2O, the nanohybrids show much lower resistivity and higher glucose oxidation activity (a lower over-potential and higher current-output) compared to the Cu2O counterpart. As an example of application, a nanocomposite-based electrode is employed for a nonenzymatic glucose biosensor application, and exhibits a linear detection upper limit of 40 mM, a sensitivity of 1434.12 µA cm-2 mM-1, and good selectivity.