Construction of 3D-Printed Sodium Alginate/Chitosan/Halloysite Nanotube Composites as Adsorbents of Methylene Blue.

In this study, sodium alginate/chitosan/halloysite nanotube composites were prepared by three-dimensional printing and characterized in terms of morphology, viscosity, thermal properties, and methylene blue (MB) adsorption performance. The high specific surface area and extensively microporous structure of these composites allowed for effective MB removal from wastewater; specifically, a removal efficiency of 80% was obtained after a 60 min treatment at an adsorbent loading of 1 g L-1 and an MB concentration of 80 mg L-1, while the maximum MB adsorption capacity equaled 376.3 mg g-1. Adsorption kinetics and isotherms were well described by quasi-second-order and Langmuir models, respectively. The composites largely retained their adsorption performance after five adsorption-desorption cycles and were concluded to hold great promise for MB removal from wastewater.

Poly (vinyl alcohol)/sodium alginate/carboxymethyl chitosan multifunctional hydrogel loading HKUST-1 nanoenzymes for diabetic wound healing.

Bacterial infection, hyperinflammation and hypoxia, which can lead to amputation in severe cases, are frequently observed in diabetic wounds, and this has been a critical issue facing the repair of chronic skin injuries. In this study, a copper-based MOF (TAX@HKUST-1) highly loaded with taxifolin (TAX) with a drug loading of 41.94 ± 2.60 % was prepared. In addition, it has excellent catalase activity, and by constructing an oxygen-releasing hydrogel (PTH) system with calcium peroxide (CaO2), it can be used as a nano-enzyme to promote the generation of oxygen from hydrogen peroxide (H2O2) to provide sufficient oxygen to the wound, and at the same time, solve the problem of the oxidative stress damage caused by excess H2O2 to the cells during the oxygen-releasing process. On the other hand, TAX and HKUST-1 in PTH synergistically promoted antimicrobial and anti-oxidative stress properties, and the bacterial inhibition rate against Staphylococcus aureus and Escherichia coli reached 90 %. In vivo experiments have shown that PTH hydrogel is able to treat diabetic skin repair by inhibiting the expression of inflammation-related proteins and promoting epidermal neogenesis, angiogenesis and collagen deposition.

Multifunctional biomaterial hydrogel loaded with antler blood peptide effectively promotes wound repair.

Diabetes is an epidemic in contemporary society, which seriously affects people's health. Therefore, it is imperative to develop a multifunctional wound dressing that can expedite the healing of diabetic wounds. In this study, quaternized oxidized sodium alginate (QOSA) and carboxymethyl chitosan (CMCS) formed hydrogel through Schiff base reaction, and the composite hydrogel was prepared by adding the antioxidant activity of deer antler blood polypeptide (D). The hydrogel exhibits favorable attributes, including a high swelling ratio, biocompatibility, and noteworthy antioxidant, antibacterial, and hemostatic properties. Finally, it was used to evaluate its effectiveness in repairing diabetic wounds. Upon evaluation, this hydrogel can effectively promote diabetic wound healing. It facilitates cell proliferation at the wound site, mitigates inflammatory responses, and enhances the expression of growth factors at the wound site. This suggests that this hydrogel holds significant promise as an ideal candidate for advanced wound dressings.

Path planning and collision avoidance methods for distributed multi-robot systems in complex dynamic environments.

Multi-robot systems are experiencing increasing popularity in joint rescue, intelligent transportation, and other fields. However, path planning and navigation obstacle avoidance among multiple robots, as well as dynamic environments, raise significant challenges. We propose a distributed multi-mobile robot navigation and obstacle avoidance method in unknown environments. First, we propose a bidirectional alternating jump point search A* algorithm (BAJPSA*) to obtain the robot's global path in the prior environment and further improve the heuristic function to enhance efficiency. We construct a robot kinematic model based on the dynamic window approach (DWA), present an adaptive navigation strategy, and introduce a new path tracking evaluation function that improves path tracking accuracy and optimality. To strengthen the security of obstacle avoidance, we modify the decision rules and obstacle avoidance rules of the single robot and further improve the decision avoidance capability of multi-robot systems. Moreover, the mainstream prioritization method is used to coordinate the local dynamic path planning of our multi-robot systems to resolve collision conflicts, reducing the difficulty of obstacle avoidance and simplifying the algorithm. Experimental results show that this distributed multi-mobile robot motion planning method can provide better navigation and obstacle avoidance strategies in complex dynamic environments, which provides a technical reference in practical situations.

Effective Modulation of Ion Mobility through Solid-State Single-Digit Nanopores.

Many experimental studies have proved that ion dynamics in a single-digit nanopore with dimensions comparable to the Debye length deviate from the bulk values, but we still have critical knowledge gaps in our understanding of ion transport in nanoconfinement. For many energy devices and sensor designs of nanoporous materials, ion mobility is a key parameter for the performance of nanofluidic equipment. However, investigating ion mobility remains an experimental challenge. This study experimentally investigated the monovalent ion dynamics of single-digit nanopores from the perspective of ionic conductance. In this article, we present a theory that is sufficient for a basic understanding of ion transport through a single-digit nanopore, and we subdivided and separately analyzed the contribution of each conductance component. These conclusions will be useful not only in understanding the behavior of ion migration but also in the design of high-performance nanofluidic devices.

Electronic and Potential Synergistic Effects of Surface-Doped P-O Species on Uniform Pd Nanospheres: Breaking the Linear Scaling Relationship toward Electrochemical Oxygen Reduction.

Developing efficient oxygen reduction reaction (ORR) electrocatalysts is critical to fuel cells and metal-oxygen batteries, but also greatly hindered by the limited Pt resources and the long-standing linear scaling relationship (LSR). In this study, ∼6 nm and highly uniform Pd nanospheres (NSs) having surface-doped (SD) P-O species are synthesized and evenly anchored onto carbon blacks, which are further simply heat-treated (HT). Under alkaline conditions, Pd/SDP-O NSs/C-HT exhibits respective 8.7 (4.3)- and 5.0 (5.5)-fold enhancements in noble-metal-mass- and area-specific activity (NM-MSA and ASA) compared with the commercial Pd/C (Pt/C). It also possesses an improved electrochemical stability. Besides, its acidic ASA and NM-MSA are 2.9 and 5.1 times those of the commercial Pd/C, respectively, and reach 65.4 and 51.5% of those of the commercial Pt/C. Moreover, it also shows nearly ideal 4-electron ORR pathways under both alkaline and acidic conditions. The detailed experimental and theoretical analyses reveal the following: (1) The electronic effect induced by the P-O species can downshift the surface d-band center to weaken the intermediate adsorptions, thus preserving more surface active sites. (2) More importantly, the potential hydrogen bond between the O atom in the P-O species and the H atom in the hydrogen-containing intermediates can in turn stabilize their adsorptions, thus breaking the ORR LSR toward more efficient ORRs and 4-electron pathways. This study develops a low-cost and high-performance ORR electrocatalyst and proposes a promising strategy for breaking the ORR LSR, which may be further applied in other electrocatalysis.

Fabrication of Chitosan/Hydroxyethyl Cellulose/TiO2 Incorporated Mulberry Anthocyanin 3D-Printed Bilayer Films for Quality of Litchis.

In this study, a bilayer antibacterial chromogenic material was prepared using chitosan (CS) and hydroxyethyl cellulose (HEC) as inner substrate, mulberry anthocyanins (MA) as a natural tracer, and titanium dioxide nanoparticles (nano-TiO2)/CS:HEC as a bacteriostatic agent for the outer layer. By investigating their apparent viscosity and suitability for 3D printing links, the optimal ratio of the substrates was determined to be CS:HEC = 3:3. Viscosity of the CH was moderate. The printing process was consistent and exhibited no breakage or clogging. The printed image was highly stable and not susceptible to collapse and diffusion. Scanning electron microscopy and infrared spectroscopy indicated that intermolecular binding between the substances exhibited good compatibility. Titanium dioxide nanoparticles (nano-TiO2) were evenly distributed in the CH and no agglomeration was observed. The inner film fill rates affected the overall performance of the chromogenic material, with strong inhibitory effects against Escherichia coli and Staphylococcus aureus at different temperatures, as well as strong color stability. The experimental results indicated that the double-layer antibacterial chromogenic material can, to a certain extent, extend the shelf life of litchi fruit and determine the extent of its freshness. Therefore, from this study, we can infer that the research and development of active materials have a certain reference value.

Effect of laser power on cleaning mechanism and surface properties.

In this paper, the mechanism of laser dry cleaning was introduced, and the influence of different power on laser cleaning effect and surface performance after cleaning were investigated. The cleaning effect of 60-120 W cleaning power on the oxidized layer of a Q235 surface was analyzed by experiment and simulation. The results showed that the cleaning power of 70 W makes the surface performance after cleaning of the samples relatively optimized. The best cleaning power is 90 W. The sample surface of 100 W is the smoothest, but it causes slight damage to the matrix. The cleaning power of 120 W has the maximum friction coefficient, but it has the maximum damage to the matrix.

CxNy particles@N-doped porous graphene: a novel cathode catalyst with a remarkable cyclability for Li-O2 batteries.

Despite the intrinsic advantages of ultra-high theoretical capacity and energy density of lithium-O2 batteries, there remain several critical issues to be resolved, especially the two concerning poor cyclability and rate capability. In this work, CxNy particles@N-doped porous graphene (CxNy@NPG) with a novel three-dimensional architecture is successfully synthesized via a simple template method and employed as the cathode catalyst of Li-O2 batteries. It is surprisingly found that the as-synthesized CxNy@NPG cathode not only demonstrates a remarkable cycling performance of 200 cycles at 1000 mA g-1 but also an intriguing high-rate capability with 8892 mA h g-1 at 1000 mA g-1, both of which can be attributed to a synergistic effect between the unique 3D porous structure and an effective N-doping. Specifically, it is believed that the unique porous 3D structure will, on one hand, build numerous microchannels, thus facilitating rapid O2 diffusion, and on the other hand, provide sufficient storage space to accommodate adequate discharge products. Indispensably, it is also believed that the N-doped porous graphene enables improved bifunctional catalytic activities towards both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), thus decreasing the discharge/charge overpotential, and reducing undesired side reactions. It is anticipated that the new 3D porous CxNy@NPG provides an inspiring route to design long cycling and high-rate performance cathodes for Li-O2 batteries.

Soft-Templated Self-Assembly of Mesoporous Anatase TiO2/Carbon Composite Nanospheres for High-Performance Lithium Ion Batteries.

Mesoporous anatase TiO2/carbon composite nanospheres (designated as meso-ATCCNs) were successfully synthesized via a facile soft-templated self-assembly followed by thermal treatment. Structural and morphological analyses reveal that the as-synthesized meso-ATCCNs are composed of primary TiO2 nanoparticles (∼5 nm), combined with in situ deposited carbon either on the surface or between the primary TiO2 nanoparticles. When cycled in an extended voltage window from 0.01 to 3.0 V, meso-ATCCNs exhibit excellent rate capabilities (413.7, 289.7, and 206.8 mAh g(-1) at 200, 1000, and 3000 mA g(-1), respectively) as well as stable cyclability (90% capacity retention over 500 cycles at 1000 mA g(-1)). Compared with both mesoporous TiO2 nanospheres and bulk TiO2, the superior electrochemical performance of the meso-ATCCNs electrode could be ascribed to a synergetic effect induced by hierarchical structure that includes uniform TiO2 nanoparticles, the presence of hydrothermal carbon derived from phenolic resols, a high surface area, and open mesoporosity.

The effect of resveratrol on surgery-induced epidural fibrosis in laminectomy rats.

Epidural fibrosis (EF) is a common complication for the patients who underwent laminectomy. Recently, EF is thought to cause recurrent postoperative pain after laminectomy. Resveratrol has been shown to exert its anti-inflammatory, antifibrotic, and antiproliferative multifaceted properties. The object of this study was to investigate the effects of resveratrol on the prevention of postlaminectomy EF formation in laminectomy rats. A controlled double-blinded study was performed on 60 healthy adult Sprague-Dawley rats that underwent lumbar laminectomy at the L1-L2 levels. They were divided randomly into 3 groups (1, 2, and 3) of 20 rats each-group 1: resveratrol treatment group; group 2: resveratrol dilution saline treatment group; group 3: sham group (rats underwent laminectomy without treatment). All rats were killed 4 weeks after operation. The Rydell score, hydroxyproline content, vimentin cells density, fibroblasts density, and inflammatory factors expressional levels all suggested better results in resveratrol group than the other two groups. Resveratrol is able to inhibit fibroblasts proliferation, and TGF- ß 1 and IL-6 expressions and prevent epidural fibrosis in postlaminectomy rat.

Morphology-dependent performance of CuO anodes via facile and controllable synthesis for lithium-ion batteries.

Nanostructured CuO anode materials with controllable morphologies have been successfully synthesized via a facile and environmentally friendly approach in the absence of any toxic surfactants or templates. In particular, leaf-like CuO, oatmeal-like CuO, and hollow-spherical CuO were obtained by changing the ligand agents. The structures and electrochemical performance of these as-prepared CuO were fully characterized by various techniques, and the properties were found to be strongly dependent on morphology. As anode materials for lithium-ion batteries, the leaf-like CuO and oatmeal-like CuO electrodes exhibit relatively high reversible capacities, whereas hollow-spherical CuO shows enhanced reversible capacity after initial degradation. Furthermore, an excellent high rate capability was obtained for the leaf-like CuO and hollow-spherical CuO electrodes. These results may provide valuable insights for the development of nanostructured anodes for next-generation high-performance lithium-ion batteries.

Graphene/Fe2O3/SnO2 ternary nanocomposites as a high-performance anode for lithium ion batteries.

We report an rGO/Fe2O3/SnO2 ternary nanocomposite synthesized via homogeneous precipitation of Fe2O3 nanoparticles onto graphene oxide (GO) followed by reduction of GO with SnCl2. The reduction mechanism of GO with SnCl2 and the effects of reduction temperature and time were examined. Accompanying the reduction of GO, particles of SnO2 were deposited on the GO surface. In the graphene nanocomposite, Fe2O3 nanoparticles with a size of ∼20 nm were uniformly dispersed surrounded by SnO2 nanoparticles, as demonstrated by transmission electron microscopy analysis. Due to the different lithium insertion/extraction potentials, the major role of SnO2 nanoparticles is to prevent aggregation of Fe2O3 during the cycling. Graphene can serve as a matrix for Li+ and electron transport and is capable of relieving the stress that would otherwise accumulate in the Fe2O3 nanoparticles during Li uptake/release. In turn, the dispersion of nanoparticles on graphene can mitigate the restacking of graphene sheets. As a result, the electrochemical performance of rGO/Fe2O3/SnO2 ternary nanocomposite as an anode in Li ion batteries is significantly improved, showing high initial discharge and charge capacities of 1179 and 746 mAhg(-1), respectively. Importantly, nearly 100% discharge-charge efficiency is maintained during the subsequent 100 cycles with a specific capacity above 700 mAhg(-1).