Multi-level FeCo/N-doped carbon nanosheet for peroxymonosulfate oxidation and sterilization inactivation.

Magnetic carbon-based catalysts with environmental friendliness have exhibited prominent effects on advanced oxidation processes. Herein, a multi-level FeCo/N-doped carbon nanosheet (FeCo/CNS) was synthesized by facile impregnation iron-cobalt salt onto cotton and followed by confined pyrolysis. We identified excellent advantages of the modified FeCo/CNS materials: (i) The convenience of the synthesis method and (ii) The dual effect of sterilization and contaminant degradation achieved through the FeCo/CNS-activated Peroxymonosulfate (PMS). The comparative experimental showed that FeCo/CNS could provide favorable catalytic performance, completely removing bisphenol A (BPA) and tetracycline (TC) within 5 min. Moreover, the potent sterilization properties against Staphylococcus aureus and Escherichia coli were also verified. Analysis of the degradation pathway confirmed the existence of intermediates, and toxicological research demonstrated that the toxicity of the degradation intermediates of BPA gradually decreased over time. Our research provided an excellent application of FeCo/CNS in PMS oxidation and sterilization inactivation.

Fabrication of a poly(N-isopropylacrylamide)-grafted alginate composite aerogel for efficient treatment of emulsified oily wastewater.

The treatment of emulsion wastewater poses significant challenges. In this study, a novel porous material, namely esterified bagasse/poly(N, N-dimethylacrylamide)/sodium alginate (SBS/PDMAA/Alg) aerogel, was developed for efficient demulsification and oil recovery. By grafting a poly(N-isopropylacrylamide) (PNIPAM) brush onto the SBS/PDMAA/Alg skeleton through free radical polymerization, the resulting aerogel exhibits both surface charge and a molecular brush structure. The aerogel demonstrates remarkable demulsification efficiency for cationic surfactant-stabilized emulsions at various concentrations, achieving a demulsification efficiency of 95.6% even at an oil content of 100 g L-1. Furthermore, the molecular brush structure extends the application range of the aerogel, enabling a demulsification efficiency of 98.3% for anionic and non-ionic surfactant-stabilized emulsions. The interpenetrating polymer network (IPN) structure formed by SBS, PDMAA, and alginate enhances the mechanical stability of the aerogel, enabling a demulsification efficiency of 91.3% even after 20 repeated cycles. The demulsification ability of the composite aerogel is attributed to its surface charge, high interfacial activity, and unique brush-like structure. A demulsification mechanism based on the synergistic effect of surface charge and molecular brush is proposed to elucidate the efficient demulsification process.

Atomistic Modeling of the Effect of Temperature on Interfacial Properties of 3D-Printed Continuous Carbon Fiber-Reinforced Polyamide 6 Composite: From Processing to Loading.

The combination of continuous fiber-reinforced thermoplastic composites (CFRTPCs) and the continuous fiber 3D printing (CF3DP) technique enables the rapid production of complex structural composites. In these 3D-printed composites, stress transfer primarily relies on the fiber-resin interface, making it a critical performance factor. The interfacial properties are significantly influenced by the temperatures applied during the loading and forming processes. While the effect of the loading temperature has been extensively researched, that of the forming temperature remains largely unexplored, especially from an atomistic perspective. Our research aims to employ molecular dynamics simulations to elucidate the effect of temperature on the interfacial properties of continuous carbon fiber-reinforced polyamide 6 (C/PA6) composites fabricated using the CF3DP technique, considering both loading and forming aspects. Through molecular dynamics simulations, we uncovered a positive correlation between the interfacial strength and forming temperature. Moreover, an increased forming temperature induced a notable shift in the failure mode of C/PA6 under uniaxial tensile loading. Furthermore, it was observed that increasing loading temperatures led to the deterioration of the mechanical properties of PA6, resulting in a gradual transition of the primary failure mode from adhesive failure to cohesive failure. This shift in the failure mode is closely associated with the glass transition of PA6.

Iron-Cobalt magnetic porous carbon beads activated peroxymonosulfate for enhanced degradation and Microbial inactivation.

Magnetic carbon-based catalysts are promising materials for advanced oxidation processes, offering both high catalytic activity and environmental friendliness, and hold great potential in environmental remediation. In this work, Fe and Co zeolite imidazole frameworks (ZIFs) derived micron-sized magnetic porous carbon beads (MPCBs) were prepared by phase inversion and following the carbonization procedure, and the morphological and structural characteristics of the MPCBs were confirmed. The presence of pores and channels in the MPCBs provides a specific microenvironment for the for the catalysis of the core. Bisphenol A (BPA) was selected for the targeted pollutant, and the catalytic experiments confirmed that the effective catalytic activity of MPCBs in the presence of peroxymonosulfate (PMS), which could almost completely degrade BPA in 20 min with a reaction rate of 0.368 min-1. Furthermore, the MPCBs were used to effectively bacterial inactivation. Intermediate products of the BPA degradation process were validated and the toxicological studies showed a gradual decrease in toxicity, indicating effective reduction of potential hazards. The macroscopic preparation methods we developed for MPCBs that is promising for industrial applications and has the potential to cope with complex environmental remediation.

Design and Finite Element Analysis of Artificial Braided Meniscus Model.

Currently, artificial meniscus prostheses are mostly homogenous, low strength, and difficult to mimic the distribution of internal fibers in the native meniscus. To promote the overall mechanical performance of meniscus prostheses, this paper designed a new artificial braided meniscus model and conducted finite element analysis. Firstly, we designed the spatial fiber interweaving structure of meniscus model to mimic the internal fiber distribution of the native meniscus. Secondly, we provided the detailed braiding steps and forming process principles based on the weaving structure. Thirdly, we adopted the models of the fiber-embedded matrix and multi-scale methods separately for finite element analysis to achieve the reliable elastic properties. Meanwhile, we compared the results for two models, which are basically consistent, and verified the accuracy of analysis. Finally, we conducted the comparative simulation analysis of the meniscus model and the pure matrix meniscus model based on the solved elastic constants through Abaqus, which indicated a 60% increase in strength.

Bending-Sensitive Optical Waveguide Sensor With Carbon-Fiber Layer for Monitoring Grip Strength.

With the gradual popularity of wearable devices, the demand for high-performance flexible wearable sensors is also increasing. Flexible sensors based on the optical principle have advantages e.g. anti-electromagnetic interference, antiperspirant, inherent electrical safety, and the potential for biocompatibility. In this study, an optical waveguide sensor integrating a carbon fiber layer, fully constraining stretching deformation, partly constraining pressing deformation, and allowing bending deformation, was proposed. The sensitivity of the proposed sensor is three times higher than that of the sensor without a carbon fiber layer, and good repeatability is maintained. We also attached the proposed sensor to the upper limb to monitor grip force, and the sensor signal showed a good correlation with grip force (the R-squared of the quadratic polynomial fitting was 0.9827) and showed a linear relationship when the grip force was greater than 10N (the R-squared of the linear fitting was 0.9523). The proposed sensor has the potential for applications in recognizing the intention of human movement to help the amputees control the prostheses.

Towards Automated Microfluidic-based Platforms: Optimizing Hydrogenation Efficiency of Nitrobenzene through π-π Interactions in Pd Nanoparticles on Covalent Organic Frameworks.

Microplatform with timed automata has been leveraged for guiding the preparation of molecules, whereas the requirement of handling expertise and sophisticated instrument is inevitable in combination with heterogeneous catalysis. Here we report a microfluidic-based autolab with open structures, called Put & Play Automated Microplatform (PPAM). It shows the efficient hydrogenation performance of palladium nanoparticles on the triphenylene-based covalent organic frameworks (Pd/TP-COFs) in which the π-π interactions of TP rings in the vicinity of Pd is optimized by easy change-over of catalyst and simple tuning of reactor geometries in PPAM. Using experiment/simulation of the Pd/TP-COFs coating (PCC) and mixing (PCM) across PPAM with different channel sizes, the turnover frequencies are 60 times the commonly used batch reactor, and aniline productivity of 8.8 g h-1 is achieved in 0.09 cm3 . This work will raise awareness about the benefits of the catalyst-loaded microplatform in future materials performance campaigns.

VariScreen secures the screening of high-risk varices in patients with hepatitis B virus-related cirrhosis beyond Baveno VI criteria.

We aimed to validate the performance of the ratio of the platelet count (PLT) to liver stiffness measurement (LSM) in excluding high-risk varices (HRVs) in patients with hepatitis B virus (HBV)-related compensated cirrhosis beyond Baveno VI criteria. A total of 310 patients were assessed. The performances of the PLT:LSM ratio (PLER), PLER adjusted for the international normalized ratio, etiology, age, and sex (PLEASE), and the sequential algorithm for HRV screening (VariScreen) in excluding HRVs were evaluated and compared with those of expanded Baveno VI criteria (LSM <25 kPa and PLT >110×109/L, EB6C); PLT >150×109/L and model for end-stage liver disease score = 6 (P150M6 criterion); PLT >120×109/L and albumin >36 g/L (P120A36 criterion); and albumin-bilirubin (ALBI) grade and PLT score (ALBI-PLT score). Among the enrolled patients, 43 (13.9%) had HRVs. The area under the receiver operating characteristic curve of PLER for predicting HRVs (0.771, 95% confidence interval, 0.720-0.817) was significantly higher than that for PLT and LSM (p < 0.01). PLER was an independent risk factor for HRVs. VariScreen, PLEASE, and PLER could spare 20 (6.5%), 91 (29.4%), and 60 (19.4%) endoscopies, with 0, 3 (3.3%), and 1 (1.7%) HRVs missed, respectively. The EB6C and P120A36 criteria could spare 45 (14.5%) and 36 (11.6%) endoscopies, with 1 (2.2%) and 1 (2.8%) HRVs missed, respectively. The P150M6 criterion and ALBI-PLT score missed 6.8% and 10.3% of HRVs, respectively. We found that PLER performed better than other non-invasive tests. VariScreen secured the screening of HRVs in patients with HBV-related cirrhosis beyond Baveno VI criteria.

Biodegradable-Glass-Fiber Reinforced Hydrogel Composite with Enhanced Mechanical Performance and Cell Proliferation for Potential Cartilage Repair.

Polyvinyl alcohol (PVA) hydrogels are promising implants due to the similarity of their low-friction behavior to that of cartilage tissue, and also due to their non-cytotoxicity. However, their poor mechanical resistance and insufficient durability restricts their application in this area. With the development of biodegradable glass fibers (BGF), which show desirable mechanical performance and bioactivity for orthopedic engineering, we designed a novel PVA hydrogel composite reinforced with biodegradable glass fibers, intended for use in artificial cartilage repair with its excellent cytocompatibility and long-term mechanical stability. Using structure characterization and thermal properties analysis, we found hydrogen bonding occurred among PVA molecular networks as well as in the PVA-BGF interface, which explained the increase in crystallinity and glass transition temperature, and was the reason for the improved mechanical performance and better anti-fatigue behavior of the composites in comparison with PVA. The compressive strength and modulus for the PBGF-15 composite reached 3.05 and 3.97 MPa, respectively, equaling the mechanical properties of human articular cartilage. Moreover, the increase in BGF content was found to support the proliferation of chondrocytes in vitro, whilst the PVA hydrogel matrix was able to control the ion concentration by adjusting the ions released from the BGF. Therefore, this novel biodegradable-glass-fiber-reinforced hydrogel composite possesses excellent properties for cartilage repair with potential in medical application.

Small-Data-Driven Temporal Convolutional Capsule Network for Locomotion Mode Recognition of Robotic Prostheses.

Locomotion mode recognition has been shown to substantially contribute to the precise control of robotic lower-limb prostheses under different walking conditions. In this study, we proposed a temporal convolutional capsule network (TCCN) which integrates the spatial-temporal-based, dilation-convolution-based, dyna- mic routing and vector-based features for recognizing locomotion mode recognition with small data rather than big-data-based neural networks for robotic prostheses. TCCN proposed in this study has four characteristics, which extracts the (1) spatial-temporal information in the data and then makes (2) dilated convolution to deal with small data, and uses (3) dynamic routing, which produces some similarities to the human brain to process the data as a (4) vector, which is different from other scalar-based networks, such as convolutional neural network (CNN). By comparison with a traditional machine learning, e.g., support vector machine(SVM) and big-data-driven neural networks, e.g., CNN, recurrent neural network(RNN), temporal convolutional network(TCN) and capsule network(CN). The accuracy of TCCN is 4.1% higher than CNN under 5-fold cross-validation of three-locomotion-mode and 5.2% higher under the 5-fold cross-validation of five-locomotion modes. The main confusion we found appears in the transition state. The results indicate that TCCN may handle small data balancing global and local information which is closer to the way how the human brain works, and the capsule layer allows for better processing vector information and retains not only magnitude information, but also direction information.

Anti-Disturbance Sliding Mode Control of a Novel Variable Stiffness Actuator for the Rehabilitation of Neurologically Disabled Patients.

Lower limb exoskeletons are widely used for rehabilitation training of patients suffering from neurological disorders. To improve the human-robot interaction performance, series elastic actuators (SEAs) with low output impedance have been developed. However, the adaptability and control performance are limited by the constant spring stiffness used in current SEAs. In this study, a novel load-adaptive variable stiffness actuator (LaVSA) is used to design an ankle exoskeleton. To overcome the problems of the LaVSA with a larger mechanical gap and more complex dynamic model, a sliding mode controller based on a disturbance observer is proposed. During the interaction process, due to the passive joints at the load side of the ankle exoskeleton, the dynamic parameters on the load side of the ankle exoskeleton will change continuously. To avoid this problem, the designed controller treats it and the model error as a disturbance and observes it with the disturbance observer (DOB) in real time. The first-order derivative of the disturbance set is treated as a bounded value. Subsequently, the parameter adaptive law is used to find the upper bound of the observation error and make corresponding compensation in the control law. On these bases, a sliding mode controller based on a disturbance observer is designed, and Lyapunov stability analysis is given. Finally, simulation and experimental verification are performed. The wearing experiment shows that the resistance torque suffered by humans under human-robot interaction is lower than 120 Nmm, which confirms that the controller can realize zero-impedance control of the designed ankle exoskeleton.

Interfacial engineering coupling with tailored oxygen vacancies in Co2Mn2O4 spinel hollow nanofiber for catalytic phenol removal.

Herein, one-dimensional Co2Mn2O4 (CMO) hollow nanofibers with a general spinel structure were constructed by electrospinning and tunning thermal-driven procedures. The resultant catalyst was endowed with appreciable active interfacial engineering effect, which revealed improved peroxymonosulfate (PMS) activation efficiency in catalytic phenol degradation with nearly 12.9 folds increment in reaction rate constant compared to the hydrothermally synthesized counterpart. Besides, tailored oxygen-vacancy sites including chemical environment and contents in the bimetallic spinel were rationally validated compared to the monometal spinel counterparts. The improved catalytic phenol degradation by reactive-oxidative-species (ROS) from PMS was well correlated with the more active Co(II) and Mn(II) species, reactive active oxygen-vacancy and the interfacial engineering effect in the CMO catalyst. These correlations were comprehensively demonstrated by various characterization techniques, catalytic results, and Density-Functional-Theoretical (DFT) calculations of the adsorption and activation of PMS. Besides, the results revealed that the specific content of cobalt species in the structural unit of the Co2Mn2O4 spinel resulting from the optimized thermal treatment could further improve the catalytic activity by the intermetallic synergy along with the beneficial electron transfer cycles. This work provides a practical understanding of the improvement of interfacial systems in catalysis efficiency and environmental remediation.

Parametric generation of three-dimensional gait for robot-assisted rehabilitation.

For robot-assisted rehabilitation and assessment of patients with motor dysfunction, the parametric generation of their normal gait as the input for the robot is essential to match with the features of the patient to a greater extent. In addition, the gait needs to be in three-dimensional space, which meets the physiological structure of the human better, rather than only on a sagittal plane. Thus, a method for the parametric generation of three-dimensional gait based on the influence of the motion parameters and structure parameters is presented. First, the three-dimensional gait kinematic of participants is collected, and trajectories of ankle joint angle and ankle center position are calculated. Second, for the trajectories, gait features are extracted including gait events indicating the physiological features of walking gait, in addition to extremes indicating the geometrical features of the trajectories. Third, regression models are derived after using leave-one-out cross-validation for model optimization. Finally, cubic splines are fitted between the predicted gait features to generate the trajectories for a full gait cycle. It is inferred that the generated curves match the measured curves well. The method presented herein gives an important reference for research into lower limb rehabilitation robots.

N-doped Cu-MOFs for efficient electrochemical determination of dopamine and sulfanilamide.

Fast and efficient tracking of micropollutants in aquatic environment by developing novel electrode materials is of great significance. Herein, a polyvinylpyrrolidone (PVP) assisted strategy is applied for synthesis of nitrogen doped Cu MOFs (N-Cu-MOF) for micropollutants electrochemical detection. The designed N-Cu-MOFs possess uniform octahedral shape with large surface area (1184 m2 g-1) and an average size of roughly 450 nm, exhibiting the excellent electroanalytical capability for the detection of multipollutants. In the case of dopamine (DA) and sulfonamides (SA) as typical microcontaminants, the designed N-Cu-MOFs exhibited wide linear ranges of 0.50 nM-1.78 mM and low detection limit (LOD, 0.15 nM, S/N = 3) for the determination of DA, as well as a linear range of 0.01-58.3 µM and LOD (0.003 µM, S/N = 3) for monitoring SA. The improved performance is attributed to the heteroatom introduction and good dispersion stability of N-Cu-MOF with PVP-decorated. The good electroanalytical ability of N-Cu-MOF for detection of DA and SA can provide a guide to efficient and rapid monitor other micropollutants and construct novel electrochemical sensors.

Controlled synthesis of bimetallic Prussian blue analogues to activate peroxymonosulfate for efficient bisphenol A degradation.

Developing high-effective catalysts with tailored composition and structure has attracted extensive attention. In this work, a serious of shape-specific Fe/Co Prussian blue analogs (PBAs), including concave, core-shell and polygonal cubes were prepared by the one-step hydrothermal reaction, which were altered by adjusting the ratio of Fe/Co in the initial reaction system. The catalytic performance toward bisphenol A (BPA) degradation was significantly affected by the ultimate structure and Fe/Co composition. Benefiting from appropriate elemental proportions, unique elemental distribution (rich Co in the core and rich Fe in the shell) and high specific surface areas, the core-shell PBAs (CSPs) exhibits significantly higher peroxymonosulfate (PMS) activation performance toward bisphenol A (BPA) degradation (96 % of removal efficiency within 2 min). The stability of the CSPs catalyst test further indicates that the Fe shell can effectively protect and inhibit the leaching of cobalt ions. Electron paramagnetic resonance (EPR) and radical quenching experiments measurement exhibited that both SO4- and OH are the main active species in the degradation process. Our work expanded new ideas of designing novel PBAs with controllable shape and specific core-shell composition with excellent catalytic performance.

Fabrication of polyvinylidene fluoride-derived porous carbon heterostructure with inserted carbon nanotube via phase-inversion coupled with annealing for capacitive deionization application.

As a promising desalination technology, capacitive deionization (CDI) has great potential to guarantee freshwater supply. It is urgently needed to explore novel electrode materials with excellent desalination performance. Herein, the PVDF-derived porous carbon heterostructure with inserted carbon nanotube (PPC/CNT) was prepared via phase-inversion coupled with annealing strategy and applied as electrode material for CDI desalination. The resultant PPC/CNT possesses the combined structural advantages of PPC and CNT, such as high specific surface, mesoporous structure and improved conductivity. By virtue of these remarkable properties, PPC/CNT exhibites an excellent electrosorption capacity of 15.1 mg/g in 500 mg/L NaCl, while that of PPC electrode is 10.3 mg/g. Specially, the charge efficiency of PPC/CNT electrode is 1.39 times higher as compared to PPC, which is largely responsible for the improvement of electrosorption capacity. Besides, PPC/CNT electrode demonstrated good cycle stability over 10 electrosorption-desorption cycles. Thus, PPC/CNT electrode presents promising prospects as CDI electrode for water desalination. This work may shed new light on the rational design of porous carbon heterostructures with suitable host matrix and improved conductivity, subsequently developing the CDI performance.

Prussian blue analogues-derived bimetallic iron-cobalt selenides for efficient overall water splitting.

The efficient and durable catalysts toward electrochemical water-splitting plays significant role in clean and renewable energy storage applications. Herein, we design the Prussian blue analogues precursor by self-assembled strategy and converted it to (Fe-Co)Se2 composite by post-selenization method. Benefiting of unique porous morphology, high electrochemically active surface area and fast electron transfer ability, the excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance of (Fe-Co)Se2 catalyst were obtained. It was revealed that only require overpotentials of 251 mV to arrive a current density of 10 mA cm-2 in OER system, and 90 mV was accomplished at a current density of 10 mA cm-2 toward the HER activity, along with low Tafel slope of 47.6 and 58.7 mV dec-1 was achieved for OER and HER, respectively. The (Fe-Co)Se2 catalysts with high electrochemical activity at the same time long-time durability may encourage more practical catalytic applications for renewable energy technologies.

Core-Shell Prussian Blue Analogs with Compositional Heterogeneity and Open Cages for Oxygen Evolution Reaction.

Here, a reduction-cation exchange (RCE) strategy is proposed for synthesizing Fe-Co based bimetallic Prussian blue analogs (PBAs) with heterogeneous composition distribution and open cage nanocage architecture. Specially, bivalent cobalt is introduced into a potassium ferricyanide solution containing hydrochloric acid and polyvinyl pyrrolidone. The uniform PBAs with opened cages are formed tardily after hydrothermal reaction. Time-dependent evolution characterization on composition elucidating the RCE mechanism is based on the sequential reduction of ferric iron and cation exchange reaction between divalent iron and cobalt. The PBA structures are confirmed by electron tomography technology, and the heterogeneous element distribution is verified by energy-dispersive X-ray spectroscopy elemental analysis, leading to the formation of core-shell PBAs with compositional heterogeneity (Fe rich shell and Co rich core) and open cage architecture. When the PBA catalysts are used to boost the oxygen evolution reaction (OER), superior OER activity and long-term stability (low overpotential of 271 mV at 10 mA cm-2 and ≈5.3% potential increase for 24 h) are achieved, which is attributed to the unique compositional and structural properties as well as high special surface areas (576.2 m2 g-1). The strategies offer insights for developing PBAs with compositional and structural multiplicity, which encourages more practical catalytic applications.

Microwave synthesis of 3D rambutan-like CuO and CuO/reduced graphene oxide modified electrodes for non-enzymatic glucose detection.

A novel type of cupric oxide (CuO) particles-reduced graphene oxide (r-GO) modified electrode has been fabricated through a facile, simple and fast microwave method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and X-ray diffraction (XRD) were employed to characterize the morphologies and structures of the as-prepared samples. The results reveal that the CuO/r-GO composite was a porous 3D rambutan-like microstructure with high surface area. Then the CuO and CuO/r-GO electrodes were constructed for their use as non-enzymatic glucose biosensors owing to their high-performance and sensitivity under alkaline conditions. The proposed biosensor exhibits glucose concentrations in the range from 0.50 µM to 3.75 mM. Besides, chronoamperometry demonstrates a desirable sensitivity of 52.1 µA mM-1 at an applied potential of 0.50 V (vs. Ag/AgCl), with a detection limit of 0.10 µM (signal/noise = 3). Most importantly, this non-enzymatic glucose biosensor has highly stable characteristics and can be manufactured into a long-term stability electrode for its application in various complicated circumstances. All these results confirm that this CuO/r-GO biosensor is a promising active material with excellent analytical properties for non-enzymatic glucose detection.

Nafion covered core-shell structured Fe3O4@graphene nanospheres modified electrode for highly selective detection of dopamine.

Nafion covered core-shell structured Fe3O4@graphene nanospheres (GNs) modified glassy carbon electrode (GCE) was successfully prepared and used for selective detection dopamine. Firstly, the characterizations of hydro-thermal synthesized Fe3O4@GNs were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Then Fe3O4@GNs/Nafion modified electrode exhibited excellent electrocatalytic activity toward the oxidations of dopamine (DA). The interference test showed that the coexisted ascorbic acid (AA) and uric acid (UA) had no electrochemical interference toward DA. Under the optimum conditions, the broad linear relationship was obtained in the experimental concentration from 0.020 µM to 130.0 µM with the detection limit (S/N=3) of 0.007 µM. Furthermore, the core-shell structured Fe3O4@GNs/Nafion/GCE was applied to the determination of DA in real samples and satisfactory results were got, which could provide a promising platform to develop excellent biosensor for detecting DA.