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Hypertrophic scar (HS) remains a major challenge for clinicians due to unsatisfactory therapeutic performance. Although inducing apoptosis of HS fibroblasts (HSFs) has proved to be an effective nonsurgical treatment strategy, potential chemotherapy resistance to apoptosis of HSFs makes the development of new and efficient strategies highly demanding. Herein, a ferroptosis‐apoptosis combined therapeutic strategy for the treatment of HS is developed through supramolecular self‐assembly between cucurbit[7]uril (CB[7]) and two bioactive agents, dihydroartemisinin (DHA) and gold nanoclusters (AuNCs). The resulting self‐assembled supramolecular nanoparticles, named CAD NPs, showed high guest loading efficiency and prominent pH‐responsive degradability in the acidic lysosomes of HSFs. Importantly, both DHA and AuNCs act synergistically to generate excessive reactive oxygen species and lipid peroxidation, leading to mitochondrial damage, and ultimately inducing concurrent ferroptosis and apoptosis on HSFs. Upon further loading into hydrogel microneedles to facilitate their transdermal delivery, these CAD NPs showed superior antiscar therapeutic effects in shortening the treatment span to 3 weeks and improving the HS appearance, as demonstrated at a rabbit ear model of HS. The present supramolecular assembly‐based ferroptosis‐apoptosis strategy provides an innovative guideline for efficiently treating HS as well as other diseases. [ABSTRACT FROM AUTHOR]

The mechanism of thermal decomposition and fire suppression, and the fire-extinguishing performance of HFO-1234yf, HCFO-1233xf and 2-BTP agents were investigated by using both experimental and theoretical methods. The different halogen atoms connected with the middle carbon atom result in the varied strength of C–X (X = F, Cl, Br) bonds, and thus different thermal stability of these agents, which could further affect the pyrolysis mechanism/products and the fire-extinguishing mechanism/performance of these agents. Owing to the generation of CF3˙, Cl˙ and Br˙ radicals, as well as some unsaturated small molecules produced by their pyrolysis, the HFO-1234yf, HCFO-1233xf and 2-BTP agents have minimum extinguishing concentrations (MECs) of 9.80 vol%, 7.28 vol% and 2.92 vol% (9.80 vol%, 7.28 vol% and 2.56 vol%) for suppressing propane-air (methane-air) flame, respectively, which are comparable to or even better than those of other hydrofluoroolefin (HFO) and hydrofluorocarbon (HFC) agents. Despite the contribution of directly produced Br˙ radicals, which have the lowest energy barrier and the highest efficiency in capturing free radicals, the Br˙ and CF3˙ radicals produced by the follow-up reactions with OH˙/H˙ radicals may also contribute a lot to the best fire-suppressing performance of 2-BTP. Due to the high reactivity of these unsaturated halogenated olefins and their pyrolysis products, exothermic reactions could occur between the original agents (or their pyrolysis products) and the OH˙/O: radicals, thus leading to the combustion-promotion effect of the HFO-1234yf, HCFO-1233xf and 2-BTP agents. The slightest combustion-promotion effect of the 2-BTP extinguishant may result from the easier generation and best performance of the Br˙ radicals, as well as the lowest energies released by the exothermic reactions. [ABSTRACT FROM AUTHOR]

Potential health hazards of nanomaterials on male reproductive system have received raising concerns. Even though Mn3O4 nanoparticles (Mn3O4-NPs) is highly effective in clinical diagnostic and therapeutic applications of human disease, its potential toxic effect on the male reproductive system has not been reported. In this study, the testis damage and fertility decrease of male rats were conducted to testify the experimental reproductive injury induced by Mn3O4-NPs. After repeated tail vein injection with 10 mg/kg/week Mn3O4-NPs for 0, 60 and 120 days, Mn3O4-NPs accumulated in the testes resulted in oxidative stress and disorder of normal serum sex hormones. Experiments in vivo and in vitro indicated that mitochondria-mediated cell apoptosis were triggered via oxidative stress, demonstrated by the upregulation of malondialdehyde (MDA) and the depolarization of mitochondrial membrane potential. Notably, Mn3O4-NPs significantly resulted in a reduction of the quantity/quality of sperm and finally caused astonishing fertility decrease. Our preliminary result implied that the application of Mn3O4-NPs could be a double-edged sword and careful consideration should be given to the clinical uses. [ABSTRACT FROM AUTHOR]

Recently, asymmetrically functionalized two‐dimensional (2D) nanomaterials have attracted fevered interest as excellent candidates for building blocks of multifunctional and multidimensional systems due to the structural symmetry‐breaking. However, their preparation process typically involves high vacuum environment or specific equipment, and the obtained samples have poor stability and low yield. In this study, a facile approach has been developed to achieve the asymmetric deposition of platinum nanoparticles (NPs) onto single side of the molybdenum disulfide (MoS2) nanosheets by pyrogenic decomposition and in‐situ functionalization. By tuning the platinum precursor to MoS2 ratio, the size distribution and morphology of the Pt NPs can be well controlled. The asymmetrical decoration of Pt NPs on MoS2 nanosheets (Pt−MoS2) may result from the superior interactions between Pt NPs and MoS2 basal surface, which are stronger than the van der Waals force between adjacent MoS2 layers. Hydrogen evolution reaction (HER) results show that higher Pt loading yields better HER performance with low overpotential of 120 mV and superior Tafel slope of 28 mV ⋅ dec−1. Significantly, the current synthetic method can be used in the asymmetrical functionalization of other 2D nanosheets as well, and could greatly advance the facile preparation and practical applications of these asymmetric nanostructures. [ABSTRACT FROM AUTHOR]

• A framework is proposed for simultaneous motion classification and continuous grasp force estimation to enhance the natural and robust control of multiple degrees of freedom (MDOF) myoelectric prostheses. • A new set of nonlinear mel-frequency spectrum features of EMG signals was designed to achieve robust EMG pattern recognition under varying contraction forces and accurate estimation of continuous grasp force. • The proposed method was tested on both able bodied subjects and amputees who are the end-users of prosthesis. • The performance of the proposed feature set was systematically compared to that of the state-of-art EMG feature sets. • Experimental results suggested that the proposed method would be beneficial for stable and fine manipulation of multifunctional prosthetic hand. Simultaneously and accurately estimating both grasp motion classes and force based on surface electromyogram (EMG) of residual arms is essential for precise grasping with a dexterous prosthetic hand. However, accurate grasping-mode prediction and grasping-force estimation often contradict each other. When performing hand grasping motion, different grasping forces will generate different EMG patterns, which would decay the grasp motion prediction accuracy. In this study, we proposed a framework of fusing motion classification and continuous grasp force estimation based on a new set of nonlinear Mel-Frequency Spectrum features of EMG signals. The performance of the proposed method was tested on eight able bodied (AB) subjects and four transradial amputees (TR) who are the end-users of dexterous prostheses. The experimental results showed that the newly proposed features obtained a significant reduction in the average classification error rate compared to other well-known feature sets, achieving improvements of about 5 % to 28 % in the average classification accuracy across all subjects and force levels. Simultaneously, the proposed features obtained the best continuous grasp force estimation accuracies with R2 (coefficient of determination) of 0.96 and 0.83, and root mean square of maximum voluntary contractions of grasp force (std%GFMVC) of 6.2 % and 10.5 % for the AB and TR subjects, respectively, compared to the previous EMG features. This study suggested that the proposed method would be helpful for the stable and fine manipulation of multifunctional prosthetic hand. [ABSTRACT FROM AUTHOR]