Two-dimensional ß-MnOOH nanosheets with high oxidase-mimetic activity for smartphone-based colorimetric sensing.

Manganese (Mn) is a versatile transition element with diverse oxidation states and significant biological importance. Mn-based nanozymes have emerged as promising catalysts in various applications. However, the direct use of manganese oxides as oxidase mimics remains limited and requires further improvement. In this study, we focus on hydroxylated manganese (MnOOH), specifically the layered form ß-MnOOH which exhibits unique electronic and structural characteristics. The two-dimensional ß-MnOOH nanosheets were synthesized through a hydrothermal approach and showed remarkable oxidase-like activity. These nanosheets effectively converted the oxidase substrate, 3,3',5,5'-tetramethylbenzidine (TMB), into its oxidized form by initiating the conversion of dissolved oxygen into ·O2-, 1O2 and ·OH. However, in the presence of L-cysteine (L-Cys), the catalytic activity of ß-MnOOH was significantly inhibited, enabling highly sensitive detection of L-Cys. This sensing strategy was successfully applied for smartphone-based L-Cys assay, offering potential utility in the diagnosis of Cys-related diseases. The exploration of layered ß-MnOOH nanosheets as highly active oxidase mimics opens up new possibilities for catalytic and biomedical applications.

Dinuclear ytterbium(III) benzamidinate complexes with bridging S32-, Se22- and Te22- ligands: synthesis, structure and magnetic properties.

Treatment of Yb(II) complex [L2Yb(THF)2] (L = PhC(NSiMe3)2) with elemental sulfur, selenium or tellurium resulted in the isolation of a series of dinuclear Yb(III) complexes featuring side-on bound S32- (1), Se22- (2) or Te22- (3) moieties, respectively. Magnetic study on these complexes revealed that 3 is a rare lanthanide telluride single-molecule magnet (SMM).

Fabrication, Processing, Properties, and Applications of Closed-Cell Aluminum Foams: A Review.

Closed-cell aluminum foams have many excellent properties, such as low density, high specific strength, great energy absorption, good sound absorption, electromagnetic shielding, heat and flame insulation, etc. As a new kind of material, closed-cell aluminum foams have been used in lightweight structures, traffic collision protections, sound absorption walls, building decorations, and many other places. In this paper, the recent progress of closed-cell aluminum foams, on fabrication techniques, including the melt foaming method, gas injection foaming method, and powder metallurgy foaming method, and on processing techniques, including powder metallurgy foaming process, two-step foaming process, cast foaming process, gas injection foaming process, mold pressing process, and integral foaming process, are summarized. Properties and applications of closed-cell aluminum foams are discussed based on the mechanical properties and physical properties separately. Special focuses are made on the newly developed cast-forming process for complex 3D parts and the improvement of mechanical properties by the development of small pore size foam fabrication and modification of cell wall microstructures.

FeCoCuMnRuB Nanobox with Dual Driving of High-Entropy and Electron-Trap Effects as the Efficient Electrocatalyst for Water Oxidation.

High-entropy borides hold potential as electrocatalysts for water oxidation. However, the synthesis of the tailored nanostructures remains a challenge due to the thermodynamic immiscibility of polymetallic components. Herein, a FeCoCuMnRuB nanobox decorated with a nanosheet array was synthesized for the first time by a "coordination-etch-reduction" method. The FeCoCuMnRuB nanobox has various structural characteristics to express the catalytic performance; meanwhile, it combines the high-entropy effect of multiple components with the electron trap effect induced by electron-deficient B, synergistically regulating its electronic structure. As a result, FeCoCuMnRuB nanobox exhibits enhanced OER activity with a low overpotential (η10 = 233 mV), high TOF value (0.0539 s-1), small Tafel slope (61 mV/dec), and a satisfactory stability for 200 h, outperforming the high-entropy alloy and low-entropy borides. This work develops a high entropy and electron-deficient B-driven strategy for motivating the catalytic performance of water oxidation, which broadens the structural diversity and category of high-entropy materials.

Preparation and Performance of Silicone Rubber Composites Modified by Polyurethane.

Silicone rubber composites with good comprehensive properties modified with polyurethane were obtained through mixing and vulcanizing methods. Firstly, the polyurethane prepolymer with double bonds was prepared by polytetrahydrofuran glycol (PTMG, Mn = 1000), isophorone diisocyanate (IPDI), and 2-hydroxyethyl methacrylate (HEMA). The prepolymer was then added to the silicone rubber compounds to prepare silicone rubber composites, combining the excellent properties of polyurethane with the silicone rubber materials. The effects of polyurethane content on the mechanical properties, insulation, hydrophobicity, thermal stability, and flame retardancy of composites were studied in detail. The results showed that the silicone rubber composites not only have good hydrophobicity, thermal stability and flame retardant properties, but the addition of polyurethane significantly improves the tensile strength at room and low temperatures and the volume resistivity of the materials. The tensile strength increased by 32.5%, and the volume resistivity nearly doubled. The excellent electrical insulation, high hydrophobicity and good mechanical properties make the silicone rubber composites appropriate for use in the field of polymeric house arresters.

Comparison and evaluation of different deep learning models of synthetic CT generation from CBCT for nasopharynx cancer adaptive proton therapy.

BACKGROUND: Cone-beam computed tomography (CBCT) scanning is used for patient setup in image-guided radiotherapy. However, its inaccurate CT numbers limit its applicability in dose calculation and treatment planning. PURPOSE: This study compares four deep learning methods for generating synthetic CT (sCT) to determine which method is more appropriate and offers potential for further clinical exploration in adaptive proton therapy for nasopharynx cancer. METHODS: CBCTs and deformed planning CT (dCT) from 75 patients (60/5/10 for training, validation and testing) were used to compare cycle-consistent Generative Adversarial Network (cycleGAN), Unet, Unet+cycleGAN and conditionalGenerative Adversarial Network (cGAN) for sCT generation. The sCT images generated by each method were evaluated against dCT images using mean absolute error (MAE), structural similarity (SSIM), peak signal-to-noise ratio (PSNR), spatial non-uniformity (SNU) and radial averaging in the frequency domain. In addition, dosimetric accuracy was assessed through gamma analysis, differences in water equivalent thickness (WET), and dose-volume histogram metrics. RESULTS: The cGAN model has demonstrated optimal performance in the four models across various indicators. In terms of image quality under global condition, the average MAE has been reduced to 16.39HU, SSIM has increased to 95.24%, and PSNR has increased to 28.98. Regarding dosimetric accuracy, the gamma passing rate (2%/2 mm) has reached 99.02%, and the WET difference is only 1.28 mm. The D95 value of CTVs coverage and Dmax value of spinal cord, brainstem show no significant differences between dCT and sCT generated by cGAN model. CONCLUSIONS: The cGAN model has been shown to be a more suitable approach for generating sCT using CBCT, considering its characteristics and concepts. The resulting sCT has the potential for application in adaptive proton therapy.

The influence of different physical exercise amounts on learning burnout in adolescents: The mediating effect of self-efficacy.

Objective: To explore the effect of physical exercise on learning burnout in adolescents, and to reveal the mediating effect of self-efficacy between different physical exercise amounts and learning burnout. Methods: A total of 610 adolescents from 5 primary and middle schools in Chongqing, China were investigated with the Physical Exercise Rating Scale (PARS-3), the General Self-Efficacy Scale (GSES), and the Learning Burnout Scale (LBS). The SPSS21.0 and AMOS21.0 statistical software were used to process and analyze the data. Results: (1) The physical exercise amount in boys was significantly higher than that in girls, but there was no significant gender difference in self-efficacy and learning burnout. Meanwhile, the academic alienation and low sense of achievement of primary school students were significantly lower than that of junior high school students, and there was no significant difference in the physical exercise amount and self-efficacy. (2) The physical exercise amount in adolescents was positively correlated with self-efficacy (r = 0.41), negatively correlated with learning burnout (r = -0.46), and self-efficacy was negatively correlated with learning burnout (r = -0.45). (3) The physical exercise amount could directly and negatively predict the learning burnout of adolescents (ß = -0.40), and self-efficacy played a partial mediating effect between the amount of physical exercise and learning burnout (ES = -0.19). (4) Self-efficacy had no significant mediating effect between low exercise amount and learning burnout, but had a significant partial mediating effect between moderate (ES = -0.15) and high exercise amount (ES = -0.22) and learning burnout, and the partial mediating effect between high exercise amount and learning burnout was the highest. Conclusion: Physical exercise was an effective way to prevent or reduce learning burnout in adolescents. It can not only directly affect learning burnout, but also indirectly affect learning burnout through the mediating effect of self-efficacy. It should be pointed out that maintaining a sufficient amount of physical exercise is crucial to improving self-efficacy and reducing learning burnout.

Protein-directed synthesis of fluorescent sulfur quantum dots for highly robust detection of pyrophosphate.

Inorganic pyrophosphate anions (PPi) play a key role in various biological processes and act as an essential indicator for physiological function evaluation and disease diagnosis. However, there is still a lack of available approaches for straightforward, robust, and convenient PPi detection. Herein, we design an on-off-on fluorescent switching nanoprobe employing Fe3+-mediated fluorescent sulfur quantum dots (SQDs) for highly robust detection of PPi. The bovine serum protein (BSA)-capped SQDs with fine water dispersibility and good optical stability are synthesized by an H2O2-assisted chemical etching reaction. Specifically, Fe3+ can strongly induce the aggregation of the SQDs into relatively larger sizes, resulting in aggregation-induced fluorescence quenching behavior. PPi can selectively bind with Fe3+ via emulative coordination and in preventing the aggregation of SQDs this is accompanied by recovery of fluorescence. The physicochemical properties of aggregated and disaggregated SQDs have been systematically investigated. Aggregation and disaggregation of the SQDs and the corresponding quenching and recovery of fluorescence occurs and guarantees the high-contrast sensing performance of the SQD system in complex and challenging aquatic environments. Our designed on-off-on nanoswitch holds great potential for the design of elemental quantum dot-based biosensors for the highly robust detection of analytes in the near future.

Exploring the Antibacterial and Biosensing Applications of Peroxidase-Mimetic Ni0.1Cu0.9S Nanoflower.

Nanozymes, as artificial enzymes with the biological action of natural enzymes, have enormous potential in the fields of disease diagnosis, bacteriostasis, biosensing, etc. In this work, the Ni0.1Cu0.9S nanoflower was successfully synthesized through a one-step hydrothermal method. A combined strategy of Ni doping and morphology design was employed to adjust its electronic structure and active sites, endowing the Ni0.1Cu0.9S nanoflower with excellent peroxidase-like activity. Therefore, it can catalyze the decomposition of H2O2 to generate •OH with higher antibacterial activity, establishing a broad-spectrum antibacterial system based on the Ni0.1Cu0.9S nanoflower against E. coli and S. aureus, which avoids the harm of a high concentration of H2O2. Additionally, the colorless substrate TMB can be catalytically oxidized into blue ox-TMB via •OH. As a result, a colorimetric technique with rapid and accurate detection of ascorbic acid (AA) by the unaided eye was designed, in view of the specific inhibition effect towards the oxidation of TMB. This detection platform has a wide linear range (10~800 µM) with a low limit of detection (0.84 µM) and exhibits a satisfactory selectivity toward the detection of AA. This study sheds new light on the application of copper-containing nanozymes in the fields of biomedicine and bioassay.

High selectivity of photocatalytic reduction of CO2 to CO based on terpyridine ligand supported CuI metal organic framework.

In this work, a 4'-(4-cynaophenyl)-4,2':6',4-terpyridine supported CuI MOFs photocatalyst (Cu I MOF) was applied to the photocatalytic CO2 reduction for the first time. The micro-structural and physicochemical properties of the Cu I MOF were systematically studied by the powder X-ray diffraction (PXRD), Single crystal X-ray diffraction (SCXRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), UV-Vis diffuse spectroscopy (UV-vis DRS), ns-level photoluminescence spectra (ns-level PL), Ultraviolet photoelectron spectroscopy (UPS), and N2 adsorption-desorption test (BET-BJH). Moreover, the in situ diffuse reflectance infrared fourier transform spectroscopy (in situ DRIFTS) was applied to investigate the adsorption and reaction intermediates of photocatalytic CO2 reduction. As a result, Cu I MOF exhibited good performance and outstanding selectivity toward photocatalytic reduction of CO2 to CO under full-spectrum and visible light illumination. Notably, 100% selective photocatalytic conversion of CO2 to CO was achieved. Thus, the study presents the high selectivity and CO2 reduction efficiency of Cu I MOF as a potential family of photocatalysts.

Colorimetric detection of total antioxidants in green tea with oxidase-mimetic CoOOH nanorings.

Green tea is a popular beverage and is widely consumed due to its taste and antioxidative polyphenols. Herein, a smartphone-based colorimetric reader using cobalt oxyhydroxide (CoOOH) nanorings has been successfully applied to detect antioxidants in green tea with high reliability and robustness. By exploiting the oxidase-mimicking activity, the as-synthesized CoOOH nanorings replaces natural enzymes to directly catalyze oxidate colorless 3,3 ´ ,5,5 ´ -tetramethylbenzidine (TMB), while antioxidants can disintegrate CoOOH, leading to an antioxidant concentration-dependent color change. Benefiting from the CoOOH nanorings-based colorimetric strategy, a smartphone-assistant nanosensor was devised for portable and visual detection of antioxidants in green tea. The proposed method can be extended to visual detection of a diverse range of diseases by responding to their specific antioxidant, and thus provide a pivotal disease toolbox that is compatible for development at the point-of-care.

Virtual reality combined with robot-assisted gait training to improve walking ability of children with cerebral palsy: A randomized controlled trial.

BACKGROUND: Children with cerebral palsy (CP) have disorders of posture and movement and which can limit physical activities such as walkingOBJECTIVE: This study aims to investigate the effectiveness of virtual reality (VR) combined with robot-assisted gait training (RAGT) on walking ability in children with CP and clarify the most effective degree of weight reduction. METHODS: Sixty CP children were recruited and randomly allocated into four different groups. The control group received conventional physical therapy (n= 15), and task groups performed VR combined with RAGT with 15% (Group A, n= 15) /30% (Group B, n= 15) /45% (Group C, n= 15) weight loss. All participants were given 50 min of therapy per session four times a week for 12 weeks and were assessed pre-and post-test with the surface electromyography (EMG), the Modified Ashworth Scale, the Gross Motor Function Measure (GMFM) dimension E and D, and Six-Minute Walking Test (6-MWT). RESULTS: All indicators had improved significantly in each group after the intervention (P< 0.05). The result of our study demonstrated that the more effective impacts of VR combined with RAGT on walking ability compared to the control group (P< 0.05), and 30% of weight loss had the best improvement in CP children (P< 0.01). CONCLUSIONS: VR combined RAGT can effectively improve walking ability in children with CP, especially when the weight loss is 30%.

Designing CoS1.035 Nanoparticles Anchored on N-Doped Carbon Dodecahedron as Dual-Enzyme Mimics for the Colorimetric Detection of H2O2 and Glutathione.

In recent years, the exploration of the nanozyme, an artificial enzyme with the structure and function of natural enzymes, has become a hot topic in this field. Although significant progress has been made, it is still a huge challenge to design nanozymes with multiple enzyme-like catalytic activities. In this work, we have successfully fabricated a colorimetric sensing platform to mimic peroxidase-like and oxidase-like activities by the CoS1.035 nanoparticles decorated N-doped carbon framework porous dodecahedrons (abbreviated to CoS1.035/N-C PDHs). And the catalytic mechanism of CoS1.035/N-C PDHs toward the peroxidase-like and oxidase-like activities is systematically explored. The results display that CoS1.035/N-C PDHs can catalyze the oxidation of the colorless substrate 3,3,'5,5'-tetramethylbenzidine (TMB) into blue oxidized TMB (ox-TMB) by disintegrating H2O2 or the physically/chemically absorbed O2 into different ROS species (·OH or O2 ·-) in the presence or absence of H2O2. Therefore, on the basis of the dual-enzyme mimic activities of CoS1.035/N-C PDHs, the bifunctional colorimetric sensing platform is established for H2O2 detection with a wide linear range of 0.5-120 µM and glutathione detection with a linear range of 1-60 µM, respectively. This work provides an efficient platform for dual-enzyme mimics, expanding the application prospect of Co-based chalcogenides as enzyme mimics in biosensing, medical diagnosis, and environment monitoring.

Functionalized Mn3 O4 Nanosheets with Photothermal, Photodynamic, and Oxidase-Like Activities Triggered by Low-Powered Near-Infrared Light for Synergetic Combating Multidrug-Resistant Bacterial Infections.

Multidrug-resistant (MDR) pathogenic bacterial infections have become a major danger to public health. Synergetic therapy through multiple approaches is more powerful than the respective one alone, but has been rarely achieved in defeating MDR bacterial infections so far. Herein, indocyanine green-functionalized Mn3 O4 nanosheets are engineered as an efficient and safe antibacterial agent with photothermal, photodynamic, and oxidase-like activities, which display powerful ability in treating MDR bacterial infections. Therein, photothermal and photodynamic activities can be triggered by a single low-powered near-infrared laser (808 nm, 0.33 W cm-2 ), resulting in the generation of localized hyperthermia (photothermal conversion efficiency, 67.5%) and singlet oxygen. Meanwhile, oxidase-like activity of this material further leads to the generation of hydroxyl radical as well as superoxide radical. Sheet-like structure with rough surfaces make them tends to adhere on bacterial surface and thus damage membrane system as well as influence bacterial metabolism. As a result, Gram-positive and Gram-negative bacteria can both be eradicated. Animal experiments further indicate that the functionalized Mn3 O4 nanosheets can effectively treat methicillin-resistant Staphylococcus aureus-infected wounds through the triple synergetic therapy. Moreover, toxicity evaluation in vitro and in vivo has proved the superior biosafety of this material, which is promising to apply in clinical anti-infective therapy.

Ultrafine platinum nanoparticles confined in a covalent organic framework for enhanced enzyme-mimetic and electrocatalytic performances.

Uniformly dispersed ultrafine platinum nanoparticles confined in a covalent organic framework (Pt/COF) have been designed and synthesized, which exhibit good catalytic activities in both enzyme-like and electrocatalytic catalysis. Benefiting from the space-confinement effect of pores in the COF matrix, the size of in situ grown Pt nanoparticles is as small as 2.44 nm with a narrow size distribution. Owing to the structure superiority, the Pt/COF catalyst exhibits much better peroxidase/oxidase-like activity than unsupported Pt nanoparticles and a physical mixture of the two components. Based on the inhibition of catalytic oxidation of the peroxidase substrate by Pt/COF, a sensitive colorimetric method is established for tannic acid sensing. Furthermore, the Pt/COF catalyst also exhibits better electrocatalytic activity and stability than commercial Pt/C catalyst towards the methanol oxidation reaction (MOR). This work demonstrates the promising application potential of COF-supported materials in both enzyme-mimetic and electrocatalytic catalysis.

Negatively Charged Sulfur Quantum Dots for Treatment of Drug-Resistant Pathogenic Bacterial Infections.

Drug-resistant pathogenic bacteria as a worldwide health threat calls for valid antimicrobial agents and tactics in clinical practice. Positively charged materials usually achieve antibacteria through binding and disrupting bacterial membranes via electrostatic interaction, however, they also usually cause hemolysis and cytotoxicity. Herein, we engineered negatively charged sulfur quantum dots (SQDs) as an efficient broad-spectrum antibiotic to kill drug-resistant bacteria in vitro and in vivo. The SQDs can destroy the bacterial membrane system and affect their metabolism due to the intrinsic antibacterial activity of elemental sulfur and catalytic generation of reactive oxygen species, which exhibit effective therapeutic effect on subcutaneously implanted infection model induced by representative pathogenic Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Plus, the negatively charged surface makes the SQDs have excellent hemocompatibility and low toxicity, which all highlight the critical prospect of the SQDs as a potent biocompatible antibacterial agent in clinical infection therapy.

An Organic Hybrid Indium-Telluride Incorporating Binuclear Complexes [In2(ea)4]2+ with a Bridging Oxygen Donor.

The new organic hybrid indium-telluride [In2(ea)2Te2]n (1; Hea = ethanolamine) exhibits a new type of one-dimensional polymeric chain based on the linkages of dinuclear [In2(ea)4]2+ and [In2Te4]2- units, which offers the first example of an indium-telluride framework incorporating binuclear complexes [In2(ea)4]2+ with a bridging O donor. 1 shows a distinctive photocurrent response and photocatalytic properties under visible-light illumination.

Fe(III)-mediated reversible catalytic activity of MoS2 nanozymes for bisphosphonate drug sensing.

Peroxidase-like activity of MoS2 quantum dots (QDs) can be reversibly regulated by means of Fe3+/alendronate sodium (ALDS)-induced aggregation/disaggregation of the QDs in solution. Specifically, Fe3+ can selectively aggregate the MoS2 QDs and thus greatly enhance their peroxidase-like activity, while such enhancement can be inhibited in the presence of ALDS owing to the competitive coordination of ALDS with Fe3+. By regulating the enzyme-like activity of MoS2 QDs, different colorimetric signal of a typical substrate of horseradish peroxidase, 3,3΄,5,5΄-tetramethylbenzidine, can be measured in the presence of H2O2. Based on this mechanism, we develop a colorimetric approach for the determination of ALDS and further applied in quality control of pharmaceutical products, utilizing either smartphone or UV-vis spectrometer as a readout. This detection method is rapid and selective, where derivatization of ALDS before detection is not needed. Such a smartphone-based colorimetric detection platform is promising to be applied in point-of-care testing at home, small clinics, or underdeveloped regions.

Intervention effect of exercise rehabilitation therapy on patients with type 2 diabetic osteoporosis.

OBJECTIVE: To explore the intervention effect of exercise rehabilitation therapy on patients with type 2 diabetic osteoporosis. METHODS: From August 2017 to November 2019, 117 patients with type 2 diabetic osteoporosis who received treatment in Nanhua Hospital affiliated to Nanhua University were selected. Among them, 54 cases were given routine treatment in the control group (CG), and 63 cases were given exercise rehabilitation therapy on the basis of routine treatment in the study group (SG). The blood glucose level, bone mineral density, quality of life, VAS score, therapeutic effect and adverse reactions were compared between the two groups. RESULTS: After treatment, the blood glucose level and VAS score in the SG were obviously lower than those in the CG, while the bone mineral density, quality of life and clinical total effective rate were obviously higher than those in the CG, and the adverse reactions were lower than those in the CG. CONCLUSION: Exercise rehabilitation therapy can significantly improve the symptoms and the quality of life of patients with type 2 diabetic osteoporosis.

The rational design of Cu2-xSe@(Co,Cu)Se2 core-shell structures as bifunctional electrocatalysts for neutral-pH overall water splitting.

Highly active and stable bifunctional electrocatalysts for H2 generation from neutral-pH water are desired, but difficult to achieve. The modification of the electronic and crystal structure of a material by element doping, morphology design and constructing a complex is a valid strategy for obtaining high-performance catalysts toward overall water splitting. In this study, a novel Cu2-xSe@(Co,Cu)Se2 core-shell structure with ultrathin (Co,Cu)Se2 nanosheets anchored as a shell on an internal Cu2-xSe core was fabricated, for the first time, by integrating the three above-mentioned modification methods. Benefiting from the synergistic effect between components and the unique structure, the Cu2-xSe@(Co,Cu)Se2 core-shell structure can serve as an efficient bifunctional electrocatalyst for both HERs and OERs in neutral-pH electrolytes with a current density of 10 mA cm-2 at the overpotentials of 106 mV and 396 mV, respectively. Additionally, the material just requires a cell voltage of 1.73 V to afford a current density of 10 mA cm-2 in a neutral two-electrode electrolyzer. Such performances significantly outperform control catalysts and analogues. Even more importantly, the original concept of coordinated regulation presented in this work can broaden our horizons in the design of new and highly efficient catalysts for neutral water splitting.