Platelike carbon-encapsulated nickel nanocrystals for efficient electrooxidation of 5-hydroxymethylfurfural.

Platelike carbon-encapsulated nickel nanocrystals (Ni@C) were engineered as a high-performance electrocatalyst for the conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). This electrocatalyst demonstrated remarkable electrocatalytic performance in oxidizing HMF at a low potential, achieving 100% HMF conversion, 97.7% FDCA yield, and 97.4% Faraday efficiency (FE).

CuO-Ni(OH)2 heterostructure nanosheets: a high-performance electrocatalyst for 5-hydroxymethylfurfural oxidation.

CuO-Ni(OH)2 heterostructure nanosheets were designed for efficient electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furanedioic acid (FDCA). The CuO-Ni(OH)2 nanosheets exhibited impressive performance, achieving 100% HMF conversion, 99.8% FDCA yield, and 98.4% faradaic efficiency.

A dual-responsive microemulsion with macroscale superlubricity and largely switchable friction.

Although stimuli-responsive microemulsions (MEMs) consisting of water, oil and surfactants have found extensive potential applications in industrial fields, a responsive MEM exhibiting either macroscale superlubricity or two friction states where its coefficient of friction (CoF) can be switched by more than one order of magnitude has not yet been reported. Moreover, although traditional liquid superlubricants can provide ultralow friction and wear, effective control over the friction between two contacting surfaces is crucial for both achieving accurate control of the operation of an instrument and fabricating smart devices. Here we create a thermo- and magneto-responsive MEM capable of providing superlubrication for metallic materials in a broad temperature range from -30 to 20 °C using n-hexane, water, surfactant DDACe ((C12H25)2N+(CH3)2[CeCl4]-) and ethylene glycol. The MEM can abruptly and dramatically switch its CoF by approximately 25 fold based on a thermally reversible MEM-emulsion (EM) transition. Its anti-freezing performance allows it to provide effective lubrication even when the surrounding temperature attains as low as -60 °C. Together with its facile preparation, ultrahigh colloidal stability and magnetically controlled migration, such a novel smart MEM is envisioned to find widespread applications in materials science.

Highly Interfacial Active Gemini Surfactants as Simple and Versatile Emulsifiers for Stabilizing, Lubricating and Structuring Liquids.

To date, locking the shape of liquids into non-equilibrium states usually relies on jamming nanoparticle surfactants at an oil/water interface. Here we show that a synthetic water-soluble zwitterionic Gemini surfactant can serve as an alternative to nanoparticle surfactants for stabilizing, structuring and additionally lubricating liquids. By having a high binding energy comparable to amphiphilic nanoparticles at the paraffin oil/water interface, the surfactant can attain near-zero interfacial tensions and ultrahigh surface coverages after spontaneous adsorption. Owing to the strong association between neighboring surfactant molecules, closely packed monolayers with high mechanical elasticity can be generated at the oil/water interface, thus allowing the surfactant to produce not only ultra-stable emulsions but also structured liquids with various geometries by using extrusion printing and 3D printing techniques. By undergoing tribochemical reactions at its sulfonic terminus, the surfactant can endow the resultant emulsions with favorable lubricity even under high load-bearing conditions. Our study may provide new insights into creating complex liquid devices and new-generation lubricants capable of combining the characteristics of both liquid and solid lubricants.

Versatile MXene Gels Assisted by Brief and Low-Strength Centrifugation.

Due to the mutual repulsion between their hydrophilic surface terminations and the high surface energy facilitating their random restacking, 2D MXene nanosheets usually cannot self-assemble into 3D macroscopic gels with various applications in the absence of proper linking agents. In this work, a rapid spontaneous gelation of Ti3C2Tx MXene with a very low dispersion concentration of 0.5 mg mL-1 into multifunctional architectures under moderate centrifugation is illustrated. The as-prepared MXene gels exhibit reconfigurable internal structures and tunable rheological, tribological, electrochemical, infrared-emissive and photothermal-conversion properties based on the pH-induced changes in the surface chemistry of Ti3C2Tx nanosheets. By adopting a gel with optimized pH value, high lubrication, exceptional specific capacitances (~ 635 and ~ 408 F g-1 at 5 and 100 mV s-1, respectively), long-term capacitance retention (~ 96.7% after 10,000 cycles) and high-precision screen- or extrusion-printing into different high-resolution anticounterfeiting patterns can be achieved, thus displaying extensive potential applications in the fields of semi-solid lubrication, controllable devices, supercapacitors, information encryption and infrared camouflaging.

Using deep learning models in magnetic resonance cholangiopancreatography images to diagnose common bile duct stones.

BACKGROUNDS AND AIMS: Magnetic resonance cholangiopancreatography (MRCP) plays a significant role in diagnosing common bile duct stones (CBDS). Currently, there are no studies to detect CBDS by using the deep learning (DL) model in MRCP. This study aimed to use the DL model You Only Look Once version 5 (YOLOv5) to diagnose CBDS in MRCP images and verify its validity compared to the accuracy of radiologists. METHODS: By collecting the thick-slab MRCP images of patients diagnosed with CBDS, 4 submodels of YOLOv5 were used to train and validate the performance. Precision, recall rate, and mean average precision (mAP) were used to evaluate model performance. Analyze possible reasons that may affect detection accuracy by validating MRCP images in 63 CBDS patients and comparing them with radiologist detection accuracy. Calculate the correctness of YOLOv5 for detecting one CBDS and multiple CBDS separately. RESULTS: The precision of YOLOv5l (0.970) was higher than that of YOLOv5x (0.909), YOLOv5m (0.874), and YOLOv5s (0.939). The mAP did not differ significantly between the 4 submodels, with the following results: YOLOv5l (0.942), YOLOv5x (0.947), YOLO5s (0.927), and YOLOv5m (0.946). However, in terms of training time, YOLOv5s was the fastest (4.8 h), detecting CBDS in only 7.2 milliseconds per image. In 63 patients the YOLOv5l model detected CBDS with an accuracy of 90.5% compared to 92.1% for radiologists, analyzing the difference between the positive group successfully identified and the unidentified negative group not. The incorporated variables include common bile duct diameter > 1 cm (p = .560), combined gallbladder stones (p = .706), maximum stone diameter (p = .057), combined cholangitis (p = .846), and combined pancreatitis (p = .656), and the number of CBDS (p = .415). When only one CBDS was present, the accuracy rate reached 94%. When multiple CBDSs were present, the recognition rate dropped to 70%. CONCLUSION: YOLOv5l is the model with the best results and is almost as accurate as the radiologist's detection of CBDS and is also capable of detecting the number of CBDS. Although the accuracy of the test gradually decreases as the number of stones increases, it can still be useful for the clinician's initial diagnosis.

Liquid Crystal Electrolyte with Lamellar Ionic Channels for All-In-One Gel Flexible Supercapacitor.

Liquid crystalline hydrogels with nanoscale order are an attractive soft material to transport ions or electrons with high efficiency. By employing noncovalent interactions between amphiphiles and solvents, defined anisotropic ordered structures can assemble that serve as interior transmissible channels. Herein, the phase behaviors of a polymerizable amphiphile of 1-vinyl-3-alkylimidazolium bromide (VCn IMBr, n = 12, 14, 16) are investigated at different concentrations in a deep eutectic solvent. The aggregation such as micelle, hexagonal, and lamellar liquid crystal phase is created. Through in-phase polymerization, the lamellar structures within an an isotropic liquid crystal can be well solidified to obtain a conductive gel electrolyte. A sandwich-structured all-in-one gel flexible supercapacitor is then built with this specific gel electrolyte. With greatly increased adhesion and minimized interfacial resistance between electrode and electrolyte, the approach will be able to create energy-storage devices with anisotropic ionic and electronic charge transportations envisioned for various electrochemical applications.

Restoring neuronal iron homeostasis revitalizes neurogenesis after spinal cord injury.

Spinal cord injury (SCI) can lead to iron overloading and subsequent neuronal ferroptosis, which hinders the recovery of locomotor function. However, it is still unclear whether the maintenance of neuronal iron homeostasis enables to revitalize intrinsic neurogenesis. Herein, we report the regulation of cellular iron homeostasis after SCI via the chelation of excess iron ions and modulation of the iron transportation pathway using polyphenol-based hydrogels for the revitalization of intrinsic neurogenesis. The reversed iron overloading can promote neural stem/progenitor cell differentiation into neurons and elicit the regenerative potential of newborn neurons, which is accompanied by improved axon reinnervation and remyelination. Notably, polyphenol-based hydrogels significantly increase the neurological motor scores from ~8 to 18 (out of 21) and restore the transmission of sensory and motor electrophysiological signals after SCI. Maintenance of iron homeostasis at the site of SCI using polyphenol-based hydrogels provides a promising paradigm to revitalize neurogenesis for the treatment of iron accumulation-related nervous system diseases.

Particle-Polymer Union with Changeable Wettability for Constructing Bijels Using a Simple Mixing Method.

Bicontinuous emulsion gels (bijels) are nonequilibrium dispersed systems with particle-stabilized continuous fluid domains, and the internal connectivity of channels brings the possibility of efficient mass transport, endowing bijels great potential in diverse applications. Different from the common method to produce bijels, the spinodal decomposition, which needs precise temperature control and is restricted by the selection of liquid pairs, in this work, a direct mixing method was performed to construct bijels, simplifying the fabrication process. The hydrophilic rod-shaped cellulose nanocrystalline (CNC) particles were in situ combined with the hydrophobic polymer, aminopropyl-terminated polydimethylsiloxane (PDMS-NH2), to acquire a controllable interfacial wettability of CNC. The CNC@mPDMS-NH2 complexes were adsorbed at the water-toluene interface and achieved a change of Pickering emulsion types, oil-in-water, bijel, and water-in-oil, through tuning the interfacial performance of CNC@mPDMS-NH2 complexes. A three-dimensional scanning image and curvature calculation were applied to verify the obtained bijel, further demonstrating the successful preparation of the bicontinuous structure. This work enriched the members of particles for stabilizing bijels and was considered to be scalable in manufacturing for applications on a large scale.

Polymerizable bijels prepared by a direct-mixing method.

A simple direct-mixing method was proposed to use a union of silica particles and amino-capped silicone oil (diNH2-PDMS) as stabilizers to form bicontinuous emulsion gels (bijels) in wide mixing proportions of silica particle/diNH2-PDMS and oil/water with a tunable channel size of the spatial continuity, which was verified by the three-dimensional reconstruction viewer and curvature analysis. By direct polymerization of the oil phase as a template, solid materials were obtained with interconnected structures.

Developing Safe Organohydrogel Sunscreens Using Polyelectrolyte-Betaine Surfactant Complexes.

Oil-in-water emulsions are extensively used in skincare products due to their improved texture, stability, and effectiveness. There is limited success in developing effective delivery systems that can selectively target the active sunscreen ingredients onto the skin surface. Herein, an organohydrogel was prepared by physical cross-linking of an oil-in-water nanoemulsion with chitosan under neutral pH conditions. In the presence of a small quantity of coconut oil, lauramidopropyl betaine and glycerol were able to emulsify the active sunscreen ingredients into nanoscale droplets with enhanced ultraviolet light absorption. A facile pH-triggered interfacial cross-linking approach was applied to transform the nanoemulsion into an organohydrogel sunscreen. Furthermore, the organohydrogel sunscreen displayed encouraging characteristics including efficient UV-blocking capacity, resistance to water, simple removal, and minimal skin penetration. This facile approach provides an effective pathway for scaling up the organohydrogels, which are highly suitable for the safe application of sunscreen.

Cascade Reaction of Thiol-Disulfide Exchange Potentiates Rapid Fabrication of Polymer Hydrogels.

We report a rapid cross-linking strategy for the fabrication of polymer hydrogels based on a thiol-disulfide cascade reaction. Specifically, thiolated polymers (e.g., poly(ethylene glycol), hyaluronic acid, sodium alginate, poly(acrylic acid), and poly(methylacrylic acid)) can be cross-linked via the trigger of Ellman's reagent, resulting in the rapid formation of hydrogels over 20-fold faster than that via the oxidation in air. The gelation kinetics of hydrogels can be tuned by varying the polymer concentration and the molar ratio of Ellman's reagent and free thiols. The obtained hydrogels can be further functionalized with functional moieties (e.g., targeting ligands) for the selective adhesion of cells. This approach is applicable to various natural and synthetic polymers for the assembly of hydrogels with a minimized gelation time, which is promising for various biological applications.

Oxidized sodium alginate/polyacrylamide hydrogels adhesive for promoting wheat growth.

Chemical modification of sodium alginate (SA) polymer chains can increase its functional group species. Sodium periodate (SP) was usually used to oxidize the hydroxyl groups on the chain of SA to aldehyde groups, the preparation of oxidized sodium alginate (OSA) using SP is not only complicated, also limits the variety of functional groups on the chain of OSA. By contrast, we have developed an innovative strategy for OSA, in which ammonium persulfate (APS) was used to oxidize SA, providing a clear elucidation of the oxidizing process and mechanism. OSA/PAM hydrogels were synthesized using OSA, the hydrogels possess excellent adhesion properties to various non-metallic and metallic substrates. Tensile and compression tests show that the cross-linked OSA/PAM hydrogels have superior mechanical properties. We exploit OSA/PAM hydrogels as soil adhesive and water-retaining agents for wheat growth. OSA/PAM hydrogels significantly improve the survival time of wheat grown in brown loam soil under a water-shortage environment, and slow down the wilting of wheat in a water-shortage environment and prolong the survival time of wheat in sandy soils. Our trials should make hydrogels important for wheat cultivation in brown loam soils and the development of desert areas.

Biologically Derived Nanoarchitectonic Coatings for the Engineering of Hemostatic Needles.

Bleeding after venipuncture could cause blood loss, hematoma, bruising, hemorrhagic shock, and even death. Herein, a hemostatic needle with antibacterial property is developed via coating of biologically derived carboxymethyl chitosan (CMCS) and Cirsium setosum extract (CsE). The rapid transition from films of the coatings to hydrogels under a wet environment provides an opportunity to detach the coatings from needles and subsequently seal the punctured site. The hydrogels do not significantly influence the healing process of the puncture site. After hemostasis, the coatings on hemostatic needles degrade in 72 h without inducing a systemic immune response. The composition of CMCS can inhibit bacteria of Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus by destroying the membrane of bacteria. The hemostatic needle with good hemostasis efficacy, antibacterial property, and safety is promising for the prevention of bleeding-associated complications in practical applications.

Photozyme-Catalyzed ATP Generation Based on ATP Synthase-Reconstituted Nanoarchitectonics.

We demonstrate that ATP synthase-reconstituted proteoliposome coatings on the surface of microcapsules can realize photozyme-catalyzed oxidative phosphorylation. The microcapsules were assembled through layer-by-layer deposition of semiconducting graphitic carbon nitride (g-C3N4) nanosheets and polyelectrolytes. It is found that electrons from polyelectrolytes are transferred to g-C3N4 nanosheets, which enhances the separation of photogenerated electron-hole pairs. Thus, the encapsulated g-C3N4 nanosheets as the photozyme accelerate oxidation of glucose into gluconic acid to yield protons under light illumination. The outward transmembrane proton gradient is established to drive ATP synthase to synthesize adenosine triphosphate. With such an assembled system, light-driven oxidative phosphorylation is achieved. This indicates that an assembled photozyme can be used for oxidative phosphorylation, which creates an unusual way for chemical-to-biological energy conversion. Compared to conventional oxidative phosphorylation systems, such an artificial design enables higher energy conversion efficiency.

Small Molecules Mediated the Chirality Transfer in Self-Assembled Nanocomposites with Strong Circularly Polarized Luminescence.

Manipulation of the chirality at all scales has a cross-disciplinary importance and may address key challenges at the heart of physical sciences. One critical question in this field is how the chirality of one entity can be transferred to the asymmetry of another entity. Here, we find that small molecules play a crucial role in the chirality transfer from chiral organic molecules to CdSe/CdS nanorods, where the handedness of the nanorod assemblies either agrees or disagrees with that of the molecular assemblies, leading to the positive or inverse chirality transfer. The assembling mode of nanorods on the molecular assemblies, where the nanorods are either lying or standing, is closely associated with the handedness of the nanorod assemblies, resulting in opposite chirality. Furthermore, we have found that circularly polarized emission from chiral assemblies of nanorods is dependent on molecular additives. The promoted luminescence dissymmetry factor (glum) of the nanocomposites with a high value of ∼0.3 could be attained under optimal conditions.

Mn-doped Ni2P: nanocrystal-decorated amorphous nanosheets for efficient electrooxidation of 5-hydroxymethylfurfural.

A Mn-doped Ni2P electrocatalyst with a unique microstructure of nanocrystal-decorated amorphous nanosheets was, for the first time, reported for the electrooxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). This electrocatalyst demonstrated superior HMF electrooxidation performance with 100% HMF conversion, 98.0% FDCA yield, and 97.8% Faraday efficiency.

A two-photon fluorescent probe for formaldehyde detection and regeneration in living cells.

A two-photon excited fluorescent probe CMB-1 has been rationally developed for the detection and regeneration of formaldehyde based on a novel nucleophilic addition of a secondary amine to FA and subsequential alcoholysis reactivity mechanism. It enables a specific turn-on response towards formaldehyde and facilitates the monitoring of exogenous and endogenous formaldehyde in living cells via both one- and two-photon microscopy, with minimal influence on its native homeostasis and local concentration.

A pH-indicating smart tag based on porous hydrogel as food freshness sensors.

HYPOTHESIS: The pH-indicating smart packaging and tags are identified within the general research and pH colorimetric smart tags are effective, non-invasive methods for indicating food freshness on a real-time basis, but their sensitivity is limited. EXPERIMENTS: In Herin, we developed a porous hydrogel with high sensitivity, water content, modulus, and safety. Hydrogels were prepared with gellan gum, starch, and anthocyanin. The phase separations provide an adjustable porous structure, which can enhance the capture and transformation of gas from food spoilage, hence improving the sensitivity. Hydrogel is physically crosslinked by the entanglement of chains through freeze-thawing cycles, and porosity can be adjusted by the addition of starch, so avoiding the use of toxicity crosslinkers and porogen. FINDINGS: Our study demonstrates that the gel undergoes an obvious color shift during the spoilage of milk and shrimp, revealing its potential application as a smart tag signaling food freshness.

Development of Tough Thermoplastic Elastomers by Leveraging Rigid-Flexible Supramolecular Segment Interplays.

Supramolecular interactions facilitate the development of tough multifunctional thermoplastic elastomers. However, the fundamental principles that govern supramolecular toughening are barely understood, and the rational design to achieve the desired high toughness remains daunting. Herein, we report a simple and robust method for toughening thermoplastic elastomers by rationally tailoring hard-soft phase separation structures containing rigid and flexible supramolecular segments. The introduced functional segments with distinct structural rigidities provide mismatched supramolecular interactions to efficiently tune the energy dissipation and bear an external load. The optimal supramolecular elastomer containing aromatic amide and acylsemicarbazide moieties demonstrates a record toughness (1.2 GJ m-3 ), extraordinary crack tolerance (fracture energy 282.5 kJ m-2 ), an ultrahigh true stress at break (2.3 GPa), good elasticity, healing ability, recyclability, and impact resistance. The toughening mechanism is validated by testing various elastomers, confirming the potential for designing and developing super-tough supramolecular materials with promising applications in aerospace and electronics.