Search Results (158)

Aqueous zinc-ion batteries (AZIBs) are promising for large-scale grid storage due to inherent safety, low cost, environmental compatibility, high theoretical capacity (820 mAhg⁻¹), and suitable redox potential (−0.763 V vs. SHE). However, practical deployment is hindered by coupled challenges at the zinc anode–hydrogen evolution, dendrite growth, and corrosion/passivation, which severely limit cycle life and coulombic efficiency. This review systematically summarizes key advances in AZIB research. It first elucidates working principles and four cathode energy storage mechanisms: Zn²⁺ insertion/extraction, H⁺/Zn²⁺ co-insertion, chemical conversion, and dissolution/deposition. Second, it examines four mainstream cathodes (manganese-based, vanadium-based, Prussian blue analogs, and organic compounds), analyzing performance bottlenecks and corresponding optimization via structural modification. Third, it explores functional mechanisms of advanced separators (polymer, inorganic/ceramic composite, MOF-based, and cellulose-based) in regulating uniform Zn²⁺ deposition and suppressing dendrites. Fourth, it summarizes anode optimization strategies: artificial protective layers for interface stabilization, electrolyte additives to modulate Zn²⁺ solvation/deposition, and 3D porous structures to reduce local current density and provide nucleation sites. Finally, key scientific challenges and future directions are discussed—multi-strategy synergy, in situ characterization, practical battery construction, and sustainable technological development, offering theoretical guidance for advancing AZIBs toward large-scale applications. This review aims to provide a comprehensive perspective spanning from materials to systems, and from mechanisms to applications. Its core objective is not merely to list the types of cathode materials, but to establish a logical bridge directly connecting “key challenges” to “optimization strategies,” with a particular emphasis on the issues and solutions related to the cathode side. Full article

Cell-based immuno-biosensors are novel platforms for studying immune responses of biological cells, with real-time insights more similar to physiological and pathological conditions. These systems utilize living immune cells as their main components, enabling them to detect disease-related biomarkers and cellular traits in a way that is often highly sensitive and label-free. Integration with microfluidics and organ-on-chip technologies has facilitated precise manipulational control over the cellular microenvironment. Not only has this resulted in high-throughput screening, but it also enabled smaller, more portable systems which can be used at the point of care. In this work, we review the recent advance in microfluidic cell-based immuno-biosensing associated with immune cells such as neutrophils, macrophages, T cell and dendrite cells. Some of the exciting developments include fusion with methods such as advanced imaging, electrical impedance sensing and application of machine learning to phenotyping. We will also elaborate on the issues related to the standardization of these systems, cell heterogeneity, and the challenges for translating these technologies for clinical application. Taken together, such integrated platforms have potential to fill the gap left in-between cellular immunology with biosensor engineering. Full article

In recent years, flow batteries have emerged as a crucial technological solution for large-scale energy storage, leveraging their unique power-capacity decoupling characteristics and long cycle life to demonstrate significant potential in applications such as renewable energy integration and grid frequency regulation. Based on differences in electrolyte systems, mainstream flow battery technologies are primarily categorized into three types: all-vanadium redox flow batteries (VRFBs), iron-chromium redox flow batteries (ICFBs), and zinc-based redox flow batteries (ZRFBs). However, each of these technologies faces critical challenges in practical commercialization: VRFBs are constrained by cost pressures due to fluctuations in vanadium resource prices and relatively low energy efficiency; ICFBs require urgent solutions to issues such as hydrogen evolution side reactions at the negative electrode and the sluggish kinetic responses of the Cr³⁺/Cr²⁺ redox couple; while ZRFBs grapple with safety concerns such as zinc dendrite growth and morphology instability. To overcome these technical bottlenecks, extensive innovative research has been conducted in key materials (electrodes, ion-exchange membranes, electrolytes). Against this backdrop, this paper systematically reviews recent advances in the modification and optimization of flow battery technologies and conducts an extended discussion on the emerging organic redox flow batteries in recent years. Full article

As a renewable energy source, solar energy holds significant potential for addressing future energy and environmental challenges. Concurrently, hydrogen (H₂), as a clean and renewable energy carrier, has garnered substantial attention. Photoelectrocatalytic water splitting to produce H₂ represents an emerging green technology for converting solar energy into hydrogen energy, which has been highly valued by researchers. The key to advancing this technology lies in identifying photoelectrode materials with high catalytic activity and stability. In this study, dendritic α-Fe was synthesized via electrodeposition at the optimal potential of −1.4 V vs. Ag/AgCl for 300 s, and the photoelectrocatalytic performance of α-Fe₂O₃@Fe was enhanced through partial oxidation annealing at 300 °C for 6 h. This approach effectively addressed the issue of the short carrier transport distance in α-Fe₂O₃. The resulting partially oxidized α-Fe₂O₃@Fe(300 °C, 6 h) exhibited a photocurrent density of 281.1 μA/cm² at +0.55 V vs. Ag/AgCl, which was 2.23 times higher than that of the fully oxidized dendritic α-Fe₂O₃(500 °C, 2 h) (125.8 μA/cm²). The influence of deposition potential on photoelectrocatalytic performance was systematically explored, and the optimal deposition potential was identified. Additionally, surface modification with 0.15 wt% Pt (ultra-low loading) was employed to further improve the photocatalytic stability of α-Fe₂O₃(500 °C, 2 h). After continuous operation for 2 h, the photocurrent of the surface-modified sample decreased by only 6.5%, indicating a substantial enhancement in stability. Full article

Fractal geometry offers a mathematical framework to quantify the complexity of brain structure and function. The fractal dimension (FD) captures self-similarity and irregularity across spatial and temporal scales, surpassing the limits of traditional Euclidean metrics. In neuroscience, FD serves as a key descriptor of the brain’s hierarchical organization—from dendritic arborization and cortical folding to neural dynamics measured by diverse neuroimaging techniques. This review summarizes theoretical foundations and methodological advances in FD estimation, including the box-counting approach for imaging, and Higuchi’s and Katz’s algorithms for electrophysiological data, addressing reliability and reproducibility issues. In addition, we illustrate how fractal analysis characterizes brain complexity in health and disease. Clinical applications include detecting white matter alterations in multiple sclerosis, atypical maturation in intrauterine growth restriction, reduced cortical complexity in Alzheimer’s disease, and altered neuroimaging patterns in schizophrenia. Emerging evidence highlights FD’s potential for distinguishing consciousness states and quantifying neural integration and differentiation. Bridging mathematics, physics, and neuroscience, fractal analysis provides a quantitative lens on the brain’s multiscale organization and pathological deviations. FD thus stands as both a theoretical descriptor and a translational biomarker whose standardization could advance precision diagnostics and understanding of neural dynamics. Full article

Synapses, abundant in the brain, are structures needed for life. Our Introduction, based on the forms of such structures published few decades ago, helped in developing recent concepts of health and diseases. Growing axons govern their growth by cell-to-cell communication, axon guidance, and synapse orientations. The assembly of synapses requires the organization and function of pre-synaptic and post-synaptic neuronal terminals with a liquid–liquid phase, governed by Ca²⁺ responses of thin astrocyte domains. Upon synapse stimulation, the clefts expand up to several folds while pre- and post-synaptic thickness remains unchanged. In additional responses, neurons co-operate with astrocytes and extracellular vesicles (EVs), the latter dependent on extracellular and intracellular spaces. Astrocyte and microglia cells and/or EV secretions induce neurons by various effects including traveling changes. Pre-synaptic responses are defined as canonical if based on neurotransmitter release; non-canonical if they are without release and are discharged by EVs, not neurotransmitters. Health and diseases depend on other general properties, such as those defined molecularly. Among neurodegenerative diseases, attention is specified by various properties of Alzheimer’s and other diagnoses. Critical identifications can be due to astrocyte and microglia cells or multiple effects induced by EVs. At present, the complexity of therapies, although of limited success, is developing innovative initiatives. Full article

The comprehensive utilisation of solid waste is a primary approach to enhancing the utilisation efficiency of mineral resources. However, vanadium-titanium slag has long faced insufficient resource utilisation due to its low activity. To address this issue, this study integrated macro and micro analytical methods to systematically investigate the effect of mechanical grinding on the activity of vanadium-titanium slag, as well as its performance when partially replacing blast furnace slag in the system of slag—converter steel slag-desulfurization gypsum ternary gel system. Additionally, the hydration mechanism of this cementitious system was analysed. The research results indicate that mechanical grinding can significantly improve the activity index of vanadium-titanium slag and increase its specific surface area. Replacing an appropriate amount of slag with vanadium-titanium slag in the slag-steel slag-desulfurization gypsum ternary gel system can effectively enhance the mechanical properties of the cementitious system. The optimal mix proportion of vanadium-titanium slag:slag:steel slag:desulfurization gypsum as 10.5:31.5:42:16 with a water-to-binder ratio of 0.32, under which the 28-day compressive strength of the specimen reached 33.50 MPa. Through multiple microscopic analysis techniques, it was found that in the alkaline environment and sulfate excitation (provided by steel slag hydration and desulfurization gypsum), the cementitious system generates hydration products such as ettringite (AFt), C–S–H, and C–A–S–H gels. Some unreacted vanadium-titanium slag particles are wrapped and intertwined by hydrated calcium silicate (aluminium) gels, forming a stable dendritic structure that provides support for the system’s strength development. Full article

As a result of welding processes in boron-alloyed martensitic armor steels, unfavorable microstructural changes occur, leading to a significant reduction in the mechanical properties of both the weld metal and the base material. The dendritic structure of the weld metal and the partial tempering in the heat-affected zone contribute to the decreased durability of structural components, thereby deteriorating their performance. This issue is particularly important since such steels are widely used not only in the defense industry but also in the mining, construction, transportation, and metallurgical sectors, where they operate under conditions of intensive abrasive wear. For this reason, the authors attempted to improve the mechanical properties of welded joints of boron-alloyed martensitic armor steel (with a nominal hardness of 500 HBW) through post-weld heat treatment. The welded joint was evaluated based on metallographic examinations using light microscopy and scanning electron microscopy, as well as abrasive wear tests carried out on a T-07 tribotester. The conducted investigations demonstrated that, under loose abrasive conditions (using electrofused alumina), heat treatment increased the wear resistance of the joints by 55% compared to the as-welded condition. The obtained results were compared with selected grades of Hardox steel commonly used in industrial applications. Full article

This study addresses the issues of coarse primary austenite dendrites and uneven graphite distribution in hypoeutectic gray cast iron. High-energy mechanical activation technology was used to prepare high-energy activated SiC particles (EASiCp), and the regulatory mechanisms of trace additions (0–0.15 wt.%) on the solidification process and microstructure properties of hypoeutectic gray cast iron were systematically investigated. The results indicate that high-energy activation treatment reduced the average particle size of SiC particles from 26.53 μm to 9.51 μm and increased their specific surface area from 0.35 m²/g to 1.78 m²/g. X-ray diffraction (XRD) analysis revealed that the grain size was refined from 55.5 nm to 17.4 nm, with significant lattice distortion. The absorption rate of EASiCp in the melt stabilized between 68–72%, with particles predominantly dispersed within the grains (78.12%) and at grain boundaries (21.88%) in sizes ranging from 0.3 to 2 μm. The addition of EASiCp enhanced the solidification undercooling from 5.3 °C to 8.4 °C and reduced the latent heat of crystallization from 162.6 J/g to 99.96 J/g due to its endothermic reaction in the melt (SiC + Fe → FeSi + C) and heterogeneous nucleation effects. In terms of microstructure, the addition of 0.15 wt.% EASiCp increased the primary austenite dendrite content by 35.29%, reduced the secondary dendrite arm spacing by 57.98%, shortened the graphite length from 0.46 mm to 0.20 mm, and refined the eutectic colony size from over 500 μm to 180 μm. The final material achieved a tensile strength of 308 MPa, an improvement of 12.82% compared to the unadded group. Mechanistic analysis showed that EASiCp facilitated direct nucleation, reaction-induced “micro-area carbon enrichment,” and a synergistic effect in suppressing grain growth, thereby optimizing the solidification microstructure and enhancing performance. This study provides a new method for the efficient nucleation control of hypoeutectic gray cast iron. Full article

The growth of lithium dendrites and the associated “dead lithium” issue significantly impair the performance and cycle life of lithium metal batteries. This study utilizes a phase-field model under constant-current discharge conditions to simulate the dissolution process of lithium dendrites. The results demonstrate that the non-uniform dissolution of lithium dendrites is a primary cause of their stripping and subsequent dead lithium formation. Specifically, a high charging voltage and a high reaction rate constant aggravate dendrite growth and dead lithium accumulation. Although a high discharging voltage accelerates dendrite dissolution, it readily induces stripping at the dendrite roots, generating more dead lithium. In contrast, increasing the temperature, enhancing the interface mobility, adjusting the anisotropy strength to a moderate level, and constructing semi-circular initial nuclei can effectively mitigate dead lithium by promoting a more uniform dissolution process. This research provides a theoretical foundation for optimizing battery operational parameters and electrode designs to improve capacity and safety. Full article

Water-induced corrosion and zinc dendrite formation seriously disrupt the Zn plating/stripping process at the anode/electrolyte interface, which results in the instability of the Zn metal anode in aqueous zinc-ion batteries. To address the issues of the zinc metal anode, three water-soluble polymers with different hydrophilic groups—polyacrylic acid (PAA), polyacrylamide (PAM), and polyethylene glycol (PEG)—were designed as electrolyte additives in ZnSO₄ electrolytes. Among them, the PAA-based system exhibited an optimal electrochemical performance, achieving a stable cycling for more than 360 h at a current density of 5 mA cm⁻² with an areal capacity of 2 mA h cm⁻². This improvement could be attributed to its carboxyl groups, which effectively suppresses zinc dendrite growth, electrode corrosion, and side reactions, thereby enhancing the cycling performance of zinc-ion batteries. This work provides a reference for the optimization of zinc anodes in aqueous zinc-ion batteries. Full article

Polymer materials have become promising candidates for next-generation energy storage, with structural tunability, multifunctionality, and compatibility with a variety of device platforms. They have a molecular design capable of customizing ion and electron transport routes, integrating redox-active species, and enhancing interfacial stability, surpassing the drawbacks of traditional inorganic systems. New developments have been made in multifunctional polymers that have the ability to combine conductivity, mechanical properties, thermal stability, and self-healing into a single scaffold system, which is useful in battery, supercapacitor, and solid-state applications. By incorporating polymers with carbon nanostructures, ceramics, or two-dimensional materials, hybrid polymer nanocomposites improve electrochemical performance, durability, and mechanical compliance, and the solid polymer electrolytes, as well as artificial solid electrolyte interphases, resolve dendrite growth and safety issues. The multifunctionality also extends to flexibility, stretchability, and miniaturization, which implies that polymers are suitable for use in wearable devices and biomedical devices. At the same time, sustainable polymer innovation focuses on bio-based feedstocks, which can be recycled, and green synthesis pathways. Polymer discovery using artificial intelligence and machine learning is faster than standard methods, predicts structure–property–performance relationships, and can be rationally engineered. Although there are difficulties in stability during long periods, scalability, and trade-offs between indeedness and mechanical endurance, polymers are a promising avenue with regard to dependable, safe, and sustainable power storage. This review presents the molecular strategies, multifunctional uses, and prospects, where polymers are at the center of the next-generation energy technologies. Full article

Aqueous zinc-ion batteries (ZIBs) have attracted growing interest as promising candidates for large-scale and flexible energy storage due to their intrinsic safety, low cost, and environmental sustainability. However, several persistent issues—such as uncontrolled Zn dendrite growth, hydrogen evolution-induced anode corrosion, and cathode dissolution—continue to hinder their commercial deployment. To address these challenges, hydrogel polymer electrolytes (HPEs) have emerged as an effective strategy. Their unique three-dimensional polymer networks not only retain water and confine ion transport, but also provide a solid–liquid hybrid environment that enhances ionic conductivity and interfacial compatibility. These features enable HPEs to suppress side reactions and improve both electrochemical stability and mechanical adaptability, which are especially valuable for flexible ZIB devices. This review first summarizes fundamental energy storage mechanisms in aqueous ZIBs, including reversible Zn²⁺ insertion/extraction, proton co-insertion, and cathode phase evolution. It then highlights recent progress in HPE design, with emphasis on polyacrylamide (PAM), polyvinyl alcohol (PVA), and polyacrylic acid (PAA)-based systems, with strategies for dendrite suppression, interfacial regulation, and mechanical robustness. Finally, current challenges and future directions are discussed, with a forward-looking perspective on scalable fabrication methods, advanced electrolyte design, and deeper mechanistic understanding necessary to fully realize the potential of HPE-enabled aqueous ZIBs. Full article

Dendritic cells (DCs) are the most highlighted cell population for cancer immunotherapy development. Currently, DC-derived exosomes show promising anti-cancer activity. Exosomes are a subpopulation of extracellular vesicles (EVs) and originate from endosomes. It transports dynamic molecular cargos such as DNA, RNA, protein, and lipid. This cellular cargo exchange reprograms the recipient cell naturally. In cancer research, DC-derived exosomes (DEXs) are used as a therapeutic tool. There are some approaches followed in the application of DEX in cancer as a therapeutic tool. DEX-based drug delivery, tumor antigen-loaded DEX, and modified DEX are applicable approaches in cancer therapy. DEXs are biocompatible, nontoxic, and have ability-specific targeting. On the other hand, this method faces some challenges, such as large-scale production, isolation, and heterogeneity. A multidisciplinary approach (advanced nanotechnology, multi-omics, and single-exosome profiling) comes up with a solution to this issue. This review provides a comprehensive overview of the DEX approach, tracing its developmental journey and therapeutic application in cancer immunotherapy. It examines key findings from clinical trials and outlines the challenges and future research directions in this field, ultimately underscoring the potential of DC-derived exosomes as a research-backed, cell-free solution for the next generation of cancer immunotherapies. Full article

The crystallization behavior of polymers affects the structure of aggregated states, which influences the properties of materials. Atomic force microscopy (AFM) is a helpful characterization tool with high spatial resolution at the nanometer-to-micrometer scale and low-destruction imaging capabilities, making it an important means of studying polymer crystallography. This review is intended for scientists in polymer materials and physics, aiming to inspire how the rich applications of AFM can be harnessed to address fundamental scientific questions in polymer crystallization. This paper reviews recent advances in polymer crystallization characterization based on AFM, focusing on its applications in visualizing hierarchical polymer crystal structures (single crystals, spherulites, dendritic crystals, and shish kebab crystals), investigating crystallization kinetics (in situ monitoring of crystal growth), and analyzing structure–property relationships (structural changes under temperature and stress). Finally, we introduce the application of the latest AFM technology in addressing key issues in polymer crystallization, such as single-molecule force spectroscopy (SMFS) and atomic force microscopy–infrared spectroscopy (AFM-IR). As AFM technology advances toward higher precision, greater efficiency, and increased functionality, it is expected to deliver more exciting developments in the field of polymer crystallization. Full article