Silica aerogels represent a distinctive class of porous nanomaterials with increasing importance in biomedical science owing to their ultralow density, extremely high specific surface area, and tunable nano to mesoporous architecture. These materials are commonly fabricated through the removal of the liquid phase from a silica gel while preserving the three-dimensional network, enabling precise control over pore size, surface chemistry, and mechanical properties. Such versatility has driven extensive exploration of silica aerogels for healthcare applications, including controlled drug delivery, tissue engineering scaffolds, biosensors, bioimaging, cancer diagnosis and therapy, wound management, and environmentally relevant biomedical technologies. Nevertheless, successful clinical translation requires careful assessment of biocompatibility, cytotoxicity, biodegradation, and long-term interactions with biological systems. Parameters such as surface silanol density, particle morphology, and degradation behavior critically influence cellular responses and inflammatory outcomes. Recent strategies, including polymer reinforcement, surface functionalization, and composite formation with biopolymers, have demonstrated significant potential to mitigate toxicity while improving mechanical integrity and biological performance. This review provides a comprehensive and up-to-date overview of silica aerogel composites for biomedical applications, emphasizing synthesis approaches, structure-property relationships, and functional performance. Particular attention is given to toxicity mechanisms, regulatory considerations, and design strategies for improved safety and efficacy.
Quasi-two-dimensional (quasi-2D) perovskites have emerged as promising materials for next-generation photovoltaic technologies owing to their ability to combine high power-conversion efficiency with improved environmental stability compared with conventional three-dimensional (3D) perovskites. The incorporation of bulky organic spacer cations into layered perovskite frameworks introduces unique structural and optoelectronic characteristics that strongly influence carrier transport, defect formation, phase distribution, and operational durability. Recent advances have demonstrated that structural engineering strategies, including spacer-cation modulation, phase regulation, crystal-orientation control, additive engineering, and interface passivation, can significantly enhance photovoltaic performance while mitigating moisture-induced degradation, ion migration, and thermal instability. This review critically discusses the structural features, charge-transport mechanisms, and stability enhancement approaches in quasi-2D perovskite solar cells. Particular emphasis is placed on the relationships among layered crystal architectures, mixed-phase distributions, anisotropic carrier transport, and interfacial recombination behavior. Recent progress in device engineering, tandem photovoltaics, flexible solar cells, and scalable fabrication strategies is also summarized, together with the remaining challenges associated with phase heterogeneity, transport limitations, reproducibility, and long-term operational stability. Finally, future research directions involving multifunctional spacer molecules, advanced interface engineering, operando characterization techniques, and scalable photovoltaic integration are highlighted. This review provides a comprehensive perspective on the development of stable and high-efficiency quasi-2D perovskite solar cells for next-generation photovoltaic applications.
In the past few decades, electronic excitation-induced changes in BiFeO3 (BFO)-type systems have attracted a lot of attention due to their potential for modifying existing material properties and exploring applications. Dense electronic excitation led by Swift Heavy Ion (SHI) irradiation can modify the structural, optical, electrical, and magnetic properties of materials. In the present study, electronic excitation-induced modifications in the structural, microstructural, and resistive switching properties of Pulsed Laser Deposition (PLD)-grown 20% Ca-doped BFO-based heterostructures using a LaNiO3 (LNO) conducting buffer layer on LaAlO3 (LAO) (100) substrates have been studied by varying the ion fluences of 5 & times; 1010, 5 & times; 1011, 1 & times; 1012, and 5 & times; 1012 ions/cm2 of 150 MeV Ag11+ ions. X-ray diffraction confirms the single-phase nature of the heterostructure along with the modulation of the structural strain with ion fluences. Atomic force microscopy (AFM) measurements show changes in grain morphologies, including the formation of hillock-like and track-like defects after ion irradiation. Cross-sectional Scanning Electron Microscopy (SEM) and Rutherford Backscattering spectroscopy (RBS) measurements confirm the interface modifications due to ion irradiation, which play an important role in charge conduction. Interface modification, formation of oxygen vacancies, and structural defects due to SHI irradiation affect the resistive switching and charge conduction in the proposed system, which is also validated by theoretical fittings of the space charge-limited conduction mechanism. In addition, the impact of ion irradiation on the optical band gap has been understood using UV-visible spectroscopy and correlated with other results.
The increasing adoption of Modular Multilevel Converter (MMC)-based High Voltage Direct Current (HVDC) systems necessitates advanced protection mechanisms to ensure the reliability and security of bulk power transmission networks. Conventional traveling wave protection techniques encounter considerable obstacles, such as heightened sensitivity to electromagnetic interference, issues in fault identification under varying operational conditions, and susceptibility to alterations in line parameters. To address these limitations, this paper presents a dual criterion-based traveling wave protection scheme tailored for two-terminal MMC-HVDC transmission lines. The proposed method leverages enhanced wavelet-based signal processing to mitigate noise interference and employs the amplitude ratio of forward and backward traveling waves to improve fault discrimination accuracy, even under dynamic operational conditions. Extensive simulations in PSCAD demonstrate the scheme’s effectiveness in achieving high-precision fault detection with rapid response times, particularly in scenarios involving high-frequency noise, high-impedance faults (up to 1000 Ω), asymmetrical faults, and frequency-dependent network parameters. Moreover, the suggested technique demonstrates resilience to switching transients, out of zone failures (in proximity to the relay terminal), and load fluctuations—significant problems that conventional methods find difficult to manage. A comparison analysis with conventional methodologies emphasizes considerable gains in sensitivity, dependability, and computing economy, indicating its better performance. This study enhances the resilience of protection systems for contemporary HVDC networks, targeting significant deficiencies in current techniques.
Huanglongbing (HLB), or citrus greening, is one of the most destructive citrus diseases, caused primarily by Candidatus Liberibacter asiaticus and transmitted by the Asian citrus psyllid, Diaphorina citri. Early diagnosis is difficult due to symptom similarity with nutrient deficiencies and the uneven distribution of the pathogen. Recent advances in detection include portable assays such as LAMP, RPA, ddPCR, CRISPR-based tests, and VOC profiling. Management strategies span pathogen-, host-, and vector-targeted approaches. Pathogen-focused methods include antimicrobial compounds, nanoparticle-based delivery, thermotherapy, and metal- or amino-acid–binding proteins; several therapeutics (Clidinium Bromide, Pimozide, Sulfasalazine, Folic acid) show potential. Host-level interventions include transgenic citrus expressing antimicrobial proteins (e.g., 2 S albumin) or stress- and insect-tolerance genes such as PRpnp. These integrated efforts highlight the need for scalable, sustainable solutions to protect global citrus production.
