Insight into Interfacial Heat Transfer of ß-Ga2O3/Diamond Heterostructures via the Machine Learning Potential.

ß-Ga2O3 is an ultrawide-band gap semiconductor with excellent potential for high-power and ultraviolet optoelectronic device applications. Low thermal conductivity is one of the major obstacles to enable the full performance of ß-Ga2O3-based devices. A promising solution for this problem is to integrate ß-Ga2O3 with a diamond heat sink. However, the thermal properties of the ß-Ga2O3/diamond heterostructures after the interfacial bonding have not been studied extensively, which are influenced by the crystal orientations and interfacial atoms for the ß-Ga2O3 and diamond interfaces. In this work, molecular dynamics simulations based on machine learning potential have been adopted to investigate the crystal-orientation-dependent and interfacial-atom-dependent thermal boundary resistance (TBR) of the ß-Ga2O3/diamond heterostructure after interfacial bonding. The differences in TBR at different interfaces are explained in detail through the explorations of thermal conductivity value, thermal conductivity spectra, vibration density of states, and interfacial structures. Based on the above explorations, a further understanding of the influence of different crystal orientations and interfacial atoms on the ß-Ga2O3/diamond heterostructure was achieved. Finally, insightful optimization strategies have been proposed in the study, which could pave the way for better thermal design and management of ß-Ga2O3/diamond heterostructures according to guidance in the selection of the crystal orientations and interfacial atoms of the ß-Ga2O3 and diamond interfaces.

Interfacial Optimization for AlN/Diamond Heterostructures via Machine Learning Potential Molecular Dynamics Investigation of the Mechanical Properties.

AlN/diamond heterostructures hold tremendous promise for the development of next-generation high-power electronic devices due to their ultrawide band gaps and other exceptional properties. However, the poor adhesion at the AlN/diamond interface is a significant challenge that will lead to film delamination and device performance degradation. In this study, the uniaxial tensile failure of the AlN/diamond heterogeneous interfaces was investigated by molecular dynamics simulations based on a neuroevolutionary machine learning potential (NEP) model. The interatomic interactions can be successfully described by trained NEP, the reliability of which has been demonstrated by the prediction of the cleavage planes of AlN and diamond. It can be revealed that the annealing treatment can reduce the total potential energy by enhancing the binding of the C and N atoms at interfaces. The strain engineering of AlN also has an important impact on the mechanical properties of the interface. Furthermore, the influence of the surface roughness and interfacial nanostructures on the AlN/diamond heterostructures has been considered. It can be indicated that the combination of surface roughness reduction, AlN strain engineering, and annealing treatment can effectively result in superior and more stable interfacial mechanical properties, which can provide a promising solution to the optimization of mechanical properties, of ultrawide band gap semiconductor heterostructures.

Interfacial Super-Assembly of Vacancy Engineered Ultrathin-Nanosheets toward Nanochannels for Smart Ion Transport and Salinity Gradient Power Conversion.

Ion-selective nanochannel membranes assembled from two-dimensional (2D) nanosheets hold immense promise for power conversion using salinity gradient. However, they face challenges stemming from insufficient surface charge density, which impairs both permselectivity and durability. Herein, we present a novel vacancy-engineered, oxygen-deficient NiCo layered double hydroxide (NiCoLDH)/cellulose nanofibers-wrapped carbon nanotubes (VOLDH/CNF-CNT) composite membrane. This membrane, featuring abundant angstrom-scale, cation-selective nanochannels, is designed and fabricated through a synergistic combination of vacancy engineering and interfacial super-assembly. The membrane shows interlayer free-spacing of ~3.62 Å, which validates the membrane size exclusion selectivity.This strategy, validated by DFT calculations and experimental data, improves hydrophilicity and surface charge density, leading to the strong interaction with K+ ions to benefit the low ion transport resistance and exceptional charge selectivity. When employed in an artificial river water|seawater salinity gradient power generator, it delivers a high-power density of 5.35 W/m2 with long-term durability (20,000s), which is almost 400% higher than that of the pristine NiCoLDH membrane. Furthermore, it displays both pH- and temperature-sensitive ion transport behavior, offering additional opportunities for optimization. This work establishes a basis for high-performance salinity gradient power conversion and underscores the potential of vacancy engineering and super-assembly in customizing 2D nanomaterials for diverse advanced nanofluidic energy devices.

pH Modulation of Super-Assembled Heteromembranes for Sustainable Chiral Sensing.

Enantioselective sensing and separation represent formidable challenges across a diverse range of scientific domains. The advent of hybrid chiral membranes offers a promising avenue to address these challenges, capitalizing on their unique characteristics, including their heterogeneous structure, porosity, and abundance of chiral surfaces. However, the prevailing fabrication methods typically involve the initial preparation of achiral porous membranes followed by subsequent modification with chiral molecules, limiting their synthesis flexibility and controllability. Moreover, existing chiral membranes struggle to achieve coupled-accelerated enantioseparation (CAE). Here, we report a replacement strategy to controllably produce mesoscale and chiral silica-carbon (MCSC) hybrid membranes that comprise chiral pores by interfacial superassembly on a macroporous alumina (AAO) membrane, in which both ion- and enantiomers can be effectively and selectively transported across the membrane. As a result, the heterostructured hybrid membrane (MCSC/AAO) exhibits enhanced selectivity for cations and enantiomers of amino acids, achieving CAE for amino acids with an isoelectric point (pI) exceeding 7. Interestingly, the MCSC/AAO system demonstrates enhanced pH-sensitive enantioseparation compared to chiral mesoporous silica/AAO (CMS/AAO) with significant improvements of 78.14, 65.37, and 14.29% in the separation efficiency, separation factor, and permeate flux, respectively. This work promises to advance the synthesis of two or more component-integrated chiral nanochannels with multifunctional properties and allows a better understanding of the origins of the homochiral hybrid membranes.

Robust Hydrogel Actuators Functioning in Multi-Environments Enabled by Thermo-Responsive Polymer Nanoparticle Coatings on Hydrogel Surfaces.

Hydrogel actuators with anisotropic structures exhibit reversible responsiveness upon the trigger of various external stimuli, rendering them promising for applications in many fields including artificial muscles and soft robotics. However, their effective operation across multiple environments remains a persistent challenge, even for widely studied thermo-responsive polymers like poly(N-isopropyl acrylamide) (PNIPAm). Current attempts to address this issue are hindered by complex synthetic procedures or specific substrates. This study introduces a straightforward methodology to grow a thin, dense PNIPAm nanoparticle layer on diverse hydrogel surfaces, creating a highly temperature-sensitive hydrogel actuator. This actuator demonstrates adaptability across various environments, including water, oil, and open air, owing to its distinct structure facilitating self-water circulation during actuation. The thin PNIPAm layer consists of interconnected PNIPAm nanoparticles synthesized via in situ interfacial precipitation polymerization, seamlessly bonded to the hydrogel substrate through an interfacial layer containing hybrid hydrogel/PNIPAm nanoparticles. This unique anisotropic structure ensures exceptional structural stability without interfacial delamination, even enduring harsh treatments such as freezing, ultrasonic irradiation, and prolonged water immersion. Remarkably, PNIPAm films on hydrogel surfaces which enable programmable 3D actuation can also be precisely patterned. This synthetic approach opens a novel pathway for fabricating advanced hydrogel actuators with broad-ranging applications.

The effect of intermittent theta burst stimulation for cognitive dysfunction: a meta-analysis.

BACKGROUND: Growing evidence suggests that cognitive dysfunction significantly impacts patients' quality of life. Intermittent theta burst stimulation (iTBS) has emerged as a potential intervention for cognitive dysfunction. However, consensus on the iTBS protocol for cognitive impairment is lacking. METHODS: We conducted searches in the Cochrane Central Register of Controlled Trials, EMBASE, PubMed, Chinese National Knowledge Infrastructure, Wanfang Database and the Chongqing VIP Chinese Science and Technology Periodical Database from their inception to January 2024. Random-effects meta-analyzes were used to calculate standardized mean differences and 95% confidence intervals. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. RESULTS: Twelve studies involving 506 participants were included in the meta-analysis. The analysis showed a trend toward improvement of total cognitive function, activities of daily living and P300 latency compared to sham stimulation in patients with cognitive dysfunction. Subgroup analysis demonstrated that these effects were restricted to patients with post-stroke cognitive impairment but not Alzheimer's disease or Parkinson's disease. Furthermore, subthreshold stimulation also exhibited a significant improvement. CONCLUSIONS: The results suggest that iTBS may improve cognitive function in patients with cognitive dysfunction, although the quality of evidence remains low. Further studies with better methodological quality should explore the effects of iTBS on cognitive function.

Super-Assembled Multilayered Mesoporous TiO2 Nanorockets for Light-Powered Space-Confined Microfluidic Catalysis.

In the field of sustainable chemistry, it is still a significant challenge to realize efficient light-powered space-confined catalysis and propulsion due to the limited solar absorption efficiency and the low mass and heat transfer efficiency. Here, novel semiconductor TiO2 nanorockets with asymmetric, hollow, mesoporous, and double-layer structures are successfully constructed through a facile interfacial superassembly strategy. The high concentration of defects and unique topological features improve light scattering and reduce the distance for charge migration and directed charge separation, resulting in enhanced light harvesting in the confined nanospace and resulting in enhanced catalysis and self-propulsion. The movement velocity of double-layered nanorockets can reach up to 10.5 µm s-1 under visible light, which is approximately 57 and 119% higher than that of asymmetric single-layered TiO2 and isotropic hollow TiO2 nanospheres, respectively. In addition, the double-layered nanorockets improve the degradation rate of the common pollutant methylene blue under sustainable visible light with a 247% rise of first-order rate constant compared to isotropic hollow TiO2 nanospheres. Furthermore, FEA simulations reveal and confirm the double-layered confined-space enhanced catalysis and self-propulsion mechanism.

Interface Engineering Overall Seawater Splitting of Self-Supporting CeOx@NiCo2O4 Arrays.

Exploring advanced electrocatalysts for overall seawater splitting is of great significance for large-scale green hydrogen production in which interface engineering has been considered as an effective strategy to enhance the intrinsic activities of the electrocatalysts. In this work, CeOx-modified NiCo2O4 nanoneedle arrays are designed and constructed in situ grown on Ni foam (NF) through a facile two-step synthesis method. Density functional theory calculations reveal that the strong interaction between CeOx and NiCo2O4 can regulate the electronic states of metal surfaces and optimize the electronic structures of the materials, essentially improving the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) properties. Specifically, in alkaline electrolytes, CeOx@NiCo2O4/NF exhibits superior electrocatalytic activities and stabilities, requiring overpotentials of 238 mV for the OER and 144 mV for the HER to achieve a current density of 10 mA cm-2. When applied to a simulated seawater splitting device, the CeOx@NiCo2O4/NF also maintains a battery voltage of 1.66 V to reach 10 mA cm-2 and exhibits good stability for over 60 h, with high faradic efficiencies (FEs) close to 100% for both the OER and HER.

pH-Responsive Micellar Nanoparticles for the Delivery of a Self-Amplifying ROS-Activatable Prodrug.

The objective of this study is to enhance the therapeutic efficacy of the anticancer drug, camptothecin (CPT) via a nanoparticle (NP) formulation using a novel amphiphilic biopolymer. We have designed a dimeric prodrug of CPT with the ability to self-amplify and respond to reactive oxygen species (ROS). For this, we incorporated the intracellular ROS generator cinnamaldehyde into a ROS-cleavable thioacetal (TA) linker to obtain the dimeric prodrug of CPT (DCPT(TA)). For its efficient NP delivery, a pH-responsive block copolymer of acetalated dextran and poly(2-ethyl-2-oxazoline) (AcDex-b-PEOz) was synthesized. The amphiphilic feature of the block copolymer enables its self-assembly into micellar NPs and results in high prodrug loading capacity and a rapid release of the prodrug under acidic conditions. Upon cellular uptake by HeLa cells, DCPT(TA)-loaded micellar NPs induce intracellular ROS generation, resulting in accelerated prodrug activation and enhanced cytotoxicity. These results indicate that this system holds significant potential as an effective prodrug delivery strategy in anticancer treatment.

Interface engineering and nanoconfinement strategies to synergistically enhance hydrogen evolution in acidic and basic media.

As a potential catalyst for hydrogen evolution reaction (HER), tungsten nitride (W2N) has attracted extensive attention, due to its Pt-like characteristic. Nevertheless, insufficient active sites, slow electron transfer, and lack of scale-up nano-synthesis methods significantly limit its practical application. Constructing multi-component active centers and interface-rich heterojunctions to increase exposed active sites and modulate interface electrons is a very effective modification strategy. Therefore, a nano-heterostructure formed from tungsten nitride, tungsten phosphide and tungsten encapsulated in N, P co-doped carbon nanofiber (W2N/WP/W@NPC) was synthesized by a flexible and scalable electrospinning technology. Experimental results reveal that abundant heterojunctions are formed, electron transfer occurs between tungsten nitride and tungsten phosphide, and carbon nanofibers play a confinement role. The optimized W2N/WP/W@NPC-3 electrocatalyst demonstrates excellent HER catalytic activity and robust stability in both acidic and base media. Furthermore, the overall water splitting performance is tested using W2N/WP/W@NPC as the cathode through a two-electrode electrolyzer, which also exhibits impressive electrochemical performance.

Conductive Robust Interfaces with Fluoro-Borate Based Electrolyte Additive for 4.6 V Well-Cycled LiNi0.90 Co0.06 Mn0.04 O2 ||Li Batteries.

Owing to the outstanding comprehensive properties of high energy density, excellent cycling ability, and reasonable cost, Ni-rich layered oxides (NCM) are the most promising cathode for lithium-ion batteries (LIBs). To further enhance the specific capacity of Ni-rich layered oxides, it is necessary to increase the cut-off voltage to a higher level. However, a higher cut-off voltage can lead to substantial structural changes and trigger interface side reactions, presenting significant challenges for practical applications (cycle life and safety). Herein, to solve above issues, tris(hexafluoroisopropyl)borate (TFPB) is introduced as a high voltage electrolyte additive for LiNi0.90 Co0.06 Mn0.04 O2 cathode. Based on detail in situ/ex situ characterization, this study proves that TFPB forms a protective solid-state interphase (SEI) layer on the Li-anode. Additionally, derivatives of TFPB are easily oxidatively decomposed to create a dense cathode electrolyte interphase (CEI) film on the cathode. This CEI film effectively prevents the continuous oxidation of the electrolyte and mitigates the adverse effects of HF on the battery. Benefit from the protective SEI and CEI layer, the LiNi0.90 Co0.06 Mn0.04 O2 ||Li battery with a TFPB-containing electrolyte maintains an unprecedented level of performance, with a capacity retention of 89.1% after 100 cycles under the ultrahigh cut-off voltage of 4.6 V (vs Li/Li+ ).

Covalent-organic framework nanobionics for robust cytoprotection.

We present a novel study introducing a durable and robust covalent-organic framework (COF) nanocoating, developed in situ on living cells. This COF nanocoating demonstrates remarkable resistance against a diverse range of lethal stressors, including high temperature, extreme pH, ultraviolet radiation, toxic metal ions, organic pollutants, and strong oxidative stress. Notably, the nanocoating exhibits exceptional cell survival enhancement under high temperature and strongly acidic conditions, an aspect yet unexplored in the case of metal-organic framework nanocoatings and other nanomaterials. Moreover, functionalization of the nanocoating with an exogenous enzyme catalase enables yeast fermentation and ethanol production even under strong oxidative stress. Our findings establish the durable and robust COF nanocoating as a reliable platform for safeguarding vulnerable microorganisms to allow their utilisation in a wide range of adverse environments.

Rapid, Tough, and Trigger-Detachable Hydrogel Adhesion Enabled by Formation of Nanoparticles In Situ.

Integrating hydrogel with other materials is always challenging due to the low mass content of hydrogels and the abundance of water at the interfaces. Adhesion through nanoparticles offers characteristics such as ease of use, reversibility, and universality, but still grapples with challenges like weak bonding. Here, a simple yet powerful strategy using the formation of nanoparticles in situ is reported, establishing strong interfacial adhesion between various hydrogels and substrates including elastomers, plastics, and biological tissue, even under wet conditions. The strong interfacial bonding can be formed in a short time (60 s), and gradually strengthened to 902 J m-2 adhesion energy within an hour. The interfacial layer's construction involves chain entanglement and other non-covalent interactions like coordination and hydrogen bonding. Unlike the permanent bonding seen in most synthetic adhesives, these nanoparticle adhesives can be efficiently triggered for removal by acidic solutions. The simplicity of the precursor diffusion and precipitation process in creating the interfacial layer ensures broad applicability to different substrates and nanoparticle adhesives without compromising robustness. The tough adhesion provided by nanoparticles allows the hydrogel-elastomer hybrid to function as a triboelectric nanogenerator (TENG), facilitating reliable electrical signal generation and output performance due to the robust interface.

Biomimetic Electronic Skin through Hierarchical Polymer Structural Design.

Human skin comprises multiple hierarchical layers that perform various functions such as protection, sensing, and structural support. Developing electronic skin (E-skin) with similar properties has broad implications in health monitoring, prosthetics, and soft robotics. While previous efforts have predominantly concentrated on sensory capabilities, this study introduces a hierarchical polymer system that not only structurally resembles the epidermis-dermis bilayer structure of skin but also encompasses sensing functions. The system comprises a polymeric hydrogel, representing the "dermis", and a superimposed nanoporous polymer film, forming the "epidermis". Within the film, interconnected nanoparticles mimic the arrangement of interlocked corneocytes within the epidermis. The fabrication process employs a robust in situ interfacial precipitation polymerization of specific water-soluble monomers that become insoluble during polymerization. This process yields a hybrid layer establishing a durable interface between the film and hydrogel. Beyond the structural mimicry, this hierarchical structure offers functionalities resembling human skin, which includes (1) water loss protection of hydrogel by tailoring the hydrophobicity of the upper polymer film; (2) tactile sensing capability via self-powered triboelectric nanogenerators; (3) built-in gold nanowire-based resistive sensor toward temperature and pressure sensing. This hierarchical polymeric approach represents a potent strategy to replicate both the structure and functions of human skin in synthetic designs.

Interfacial Assembly of 2D Graphene-Derived Ion Channels for Water-Based Green Energy Conversion.

The utilization of sustained and green energy is believed to alleviate increasing menace of global environmental concerns and energy dilemma. Interfacial assembly of 2D graphene-derived ion channels (2D-GDICs) with tunable ion/fluid transport behavior enables efficient harvesting of renewable green energy from ubiquitous water, especially for osmotic energy harvesting. In this review, various interfacial assembly strategies for fabricating diverse 2D-GDICs are summarized and their ion transport properties are discussed. This review analyzes how particular structure and charge density/distribution of 2D-GDIC can be modulated to minimize internal resistance of ion/fluid transport and enhance energy conversion efficiency, and highlights stimuli-responsive functions and stability of 2D-GDIC and further examines the possibility of integrating 2D-GDIC with other energy conversion systems. Notably, the presented preparation and applications of 2D-GDIC also inspire and guide other 2D materials to fabricate sophisticated ion channels for targeted applications. Finally, potential challenges in this field is analyzed and a prospect to future developments toward high-performance or large-scale real-word applications is offered.

2D Ordered Mesoporous Lamellar Hetero-Nanochannels with Asymmetric Wettability for Controllable Ion Transport.

Heterogeneous membranes play a crucial role in osmotic energy conversion by effectively reducing concentration polarization. However, most heterogeneous membranes mitigate concentration polarization through an asymmetric charge distribution, resulting in compromised ion selectivity. Herein, hetero-nanochannels with asymmetric wettability composed of 2D mesoporous carbon and graphene oxide are constructed. The asymmetric wettability of the membrane endows it with the ability to suppress the concentration polarization without degrading the ion selectivity, as well as achieving a diode-like ion transport feature. As a result, enhanced osmotic energy harvesting is achieved with a power density of 6.41 W m-2 . This represents a substantial enhancement of 102.80-137.85% when compared to homogeneous 2D membranes, surpassing the performance of the majority of reported 2D membranes. Importantly, the membrane can be further used for high-performance ionic power harvesting by regulating ion transport, exceeding previously reported data by 89.1%.

Fluorogen-Functionalized Mesoporous Silica Hybrid Sensing Materials: Applications in Cu2+ Detection.

Since Cu2+ ions play a pivotal role in both ecosystems and human health, the development of a rapid and sensitive method for Cu2+ detection holds significant importance. Fluorescent mesoporous silica materials (FMSMs) have garnered considerable attention in the realm of chemical sensing, biosensing, and bioimaging due to their distinctive structure and easily functionalized surfaces. As a result, numerous Cu2+ sensors based on FMSMs have been devised and extensively applied in environmental and biological Cu2+ detection over the past few decades. This review centers on the recent advancements in the methodologies for preparing FMSMs, the mechanisms underlying sensing, and the applications of FMSMs-based sensors for Cu2+ detection. Lastly, we present and elucidate pertinent perspectives concerning FMSMs-based Cu2+ sensors.

Light-Switchable Biocatalytic Covalent-Organic Framework Nanomotors for Aqueous Contaminants Removal.

Self-propelled nanomotors represent a promising class of adaptable and versatile technologies with broad applications in the realms of biomedicine and environmental remediation. Herein, we report a biocatalytic nanomotor based on a covalent-organic framework (COF) that demonstrates intelligent and switchable motion triggered by a blue-to-red light switch. Consequently, when exposed to blue light, the nanomotor significantly enhances the removal of contaminants in aqueous solutions due to its elevated mobility. Conversely, it effectively deactivates its motion and contaminant removal upon exposure to red light. This study explores the heterogeneous assembly strategy of the COF-based nanomotor and its light-controlled propulsion performance and provides a novel strategy for the regulation of movement, offering valuable insights for the design and practical applications of nanomotors.

Biocatalytic Buoyancy-Driven Nanobots for Autonomous Cell Recognition and Enrichment.

Autonomously self-propelled nanoswimmers represent the next-generation nano-devices for bio- and environmental technology. However, current nanoswimmers generate limited energy output and can only move in short distances and duration, thus are struggling to be applied in practical challenges, such as living cell transportation. Here, we describe the construction of biodegradable metal-organic framework based nanobots with chemically driven buoyancy to achieve highly efficient, long-distance, directional vertical motion to "find-and-fetch" target cells. Nanobots surface-functionalized with antibodies against the cell surface marker carcinoembryonic antigen are exploited to impart the nanobots with specific cell targeting capacity to recognize and separate cancer cells. We demonstrate that the self-propelled motility of the nanobots can sufficiently transport the recognized cells autonomously, and the separated cells can be easily collected with a customized glass column, and finally regain their full metabolic potential after the separation. The utilization of nanobots with easy synthetic pathway shows considerable promise in cell recognition, separation, and enrichment.