Nanoscale Research Letters最新文献

Graphene-based terahertz (THz) metamaterials (MMs) are at the forefront of high-sensitivity sensing, with applications spanning biochemical to environmental fields. This review examines recent advances in graphene MMs-based THz sensors, covering foundational theories and innovative designs, from complex patterns to graphene-dielectric and graphene-metal hybrids. We explore ultra-trace detection enabled by (pi)-(pi) stacking mechanisms, expanding capabilities beyond conventional refractive index-based methods. Despite significant theoretical progress, practical challenges remain due to material constraints; solutions such as multilayer graphene structures and hybrid low-mobility designs are discussed to enhance experimental feasibility. This review provides a comprehensive perspective on the evolving impact of graphene MMs, positioning them as transformative tools in multidisciplinary THz sensing.

This study presents a novel three-dimensional stacked capacitorless dynamic random access memory (1T-DRAM) architecture, designed using a partially etched nanosheet (PE NS) to overcome the scaling limitations of traditional DRAM designs. By leveraging the floating body effect, this architecture eliminates the need for capacitors, thereby improving integration density and memory performance. Through Sentaurus technology computer-aided design simulations, we compare the PE NS 1T-DRAM device with a conventional NS 1T-DRAM device to evaluate its effectiveness. The results reveal superior retention time (RT) and sensing margin (SM) performance of the proposed PE NS 1T-DRAM device, surpassing the memory criteria outlined by the International Roadmap for Devices and Systems, which requires an RT exceeding 64 ms at 358 K. This enhanced performance of the proposed device is attributed to its extension region, which functions as a potential well for efficient hole storage, as well as the suppression of Shockley‒Read‒Hall recombination. The PE NS 1T-DRAM device also demonstrates robustness to disturbances, maintaining over 89% of its SM and RT under diverse conditions. This superiority is again attributed to its extension region, which minimizes the effects of current flow and electrostatic potential rise. These results highlight the potential of the PE NS 1T-DRAM design for future high-density memory applications.

In the domain of respiratory illnesses, asthma remains a critical obstacle. The heterogeneous nature of this chronic inflammatory disease poses challenges during its treatment. Glucocorticoid-based combination drug therapy now dominates clinical treatments for asthma; however, glucocorticoid resistance, numerous adverse effects, the incidence of inadequate drug delivery, and other factors need the development of more effective therapies. In recent years, there has been extensive research on nanotechnology in medicine. It has been shown in studies that these drug delivery systems can greatly enhance targeting and bioavailability and decrease the toxicity of medication. Nanoparticle drug delivery systems offer improved therapeutic efficacy compared to conventional administration techniques. Nanotechnology enables advancements in precision medicine, offering benefits for heterogeneous conditions such as asthma. This review will examine the critical factors of asthma to consider when formulating medications, as well as the role of nanomaterials and their mechanisms of action in pulmonary medicine for asthma treatment.

Iron surface determinant B (IsdB), a Staphylococcus aureus (SA) surface protein involved in both heme iron acquisition from host hemoglobin (Hb) and bacterial adhesion, is a proven virulence factor that can be targeted for the design of antibacterial molecules or vaccines. Recent single-molecule experiments on IsdB interaction with cell adhesion factors revealed an increase of the complex lifetime upon applying a stronger force (catch bond); this was suggested to favor host invasion under shear stress. An increased bond strength under mechanical stress was also detected by Atomic Force Spectroscopy (AFS) for the interaction between IsdB and Hb. Structural information on the underlying molecular mechanisms at the basis of this behaviour in IsdB-based complexes is missing. Here, we show that the single point mutation of Pro173 in the IsdB domain responsible for Hb binding, which weakens the IsdB:Hb interaction without hampering heme extraction, totally abolishes the previously observed behavior. Remarkably, Pro173 does not directly interact with Hb, but undergoes cis–trans isomerization upon IsdB:Hb complex formation, coupled to folding-upon binding of the corresponding protein loop. Our results suggest that these events might represent the molecular basis for the stress-dependence of bond strength observed for wild type IsdB, shedding light on the mechanisms that govern the capability of SA to infect host cells.

Osteosarcoma (OS) is distinguished as a high-grade malignant tumor, characterized by rapid systemic metastasis, particularly to the lungs, resulting in very low survival rates. Understanding the complexities of tumor development and mutation is the need of the hour for the advancement of targeted therapies in cancer care. A significant innovation in this area is the use of nanotechnology, specifically nanoparticles, to tackle various challenges in cancer treatment. Iron oxide nanoparticles stand out in both therapeutic and diagnostic applications, offering a versatile platform for targeted drug delivery, hyperthermia, magneto-thermal therapy, and combinational therapy using modulation of ferroptosis pathways. These nanoparticles are easy to synthesize, non-toxic, biocompatible, and display enhanced circulation time within the system. They can also be easily conjugated to anti-cancer drugs, targeting agents, or genetic vectors that respond to specific stimuli or pH changes. The surface functionalization of these nanoparticles using bioactive molecules unveils a promising and effective nanoparticle system for assisting osteosarcoma therapy. This review will summarize the current conventional therapies for osteosarcoma and their disadvantages, the synthesis and modification of iron oxide nanoparticles documented in the literature, cellular targeting and uptake mechanism, with focus on their functionalization using natural biomaterials and application strategies towards management of osteosarcoma. The review also compiles the translational challenges and future prospects that must be addressed for clinical advancements of iron oxide based osteosarcoma treatment in the future.

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Some of the most crucial turning points in the treatment strategies for some major infectious diseases including AIDS, malaria, and TB, have been reached with the introduction of antimicrobials and vaccines. Drug resistance and poor effectiveness are key limitations that need to be overcome. Conventional liposomes have been explored as a delivery system for infectious diseases bioactives to treat infectious diseases to provide an efficient approach to maximize the therapeutic outcomes, drug stability, targetability, to reduce the side-effects of antimicrobials, and enhance vaccine performance where necessary. However, as the pathological understanding of infectious diseases become more known, the need for more advanced liposomal technologies was born to continue having a profound effect on targeted chemotherapy for infectious diseases. This review therefore provides a concise incursion into the most recent and vogue liposomal formulations used to treat infectious diseases. An appraisal of immunological, stimuli-responsive, biomimetic and functionalized liposomes and other novel modifications to conventional liposomes is assimilated in sync with mutations of resistant pathogens.

Because of their uniform and regular channels, adjustable pore size, large surface area, controllable wall composition, high hydrothermal stability, ease of functional modification, and good accessibility of larger reactant molecules, mesoporous siliceous SBA-15 is of excellent catalyst carrier that is highly versatile and has been used extensively to prepare a variety of supported catalysts with ideal catalytic properties. In this study, we report the synthesis, characterization, and catalytic application of Cu-Ag/ SBA-15 nanoalloy catalysts towards the control of microorganisms in drinking water has been reported. The Cu-Ag/SBA-15 nanoalloy catalysts with different molar mass ratio of copper to silver (Cu:Ag = 1: 0, 0.75: 0.25, 0.5: 0.5, 0.25: 0.75, 0: 1) keeping 1weight % total loading of copper and silver metals on SBA-15 support have been prepared by incipient wetness impregnation method and characterized by various characterization techniques like, low angle XRD, wide angle XRD, N₂-physcisorption and scanning electron microscopy techniques. The anti-bacterial activity of the catalysts was measured qualitatively by testing the presence of coliforms in water after contacting with the catalyst at room temperature. These nanoalloy catalysts found to be effective in controlling the microorganisms in drinking water. Among the series of the catalysts prepared, 0.25Cu-0.75Ag /SBA-15 catalyst showed superior catalytic activity. The high catalytic performance of the catalyst is due to its high surface area.

Gold nanoparticles are widely used in biomedical applications due to their unique properties. However, traditional synthesis methods generate contaminants that cause cytotoxicity and compromise the biocompatibility of the nanomaterials. Therefore, green synthesis methods are essential to produce pure and biocompatible nanoparticles, ensuring their effectiveness in biomedical applications. This study introduces a novel approach for synthesizing silica-coated gold nanoparticles (AuNP@SiO₂) using femtosecond laser ablation in water, eliminating the need for chemical reagents. The process involves three key laser-based steps: Si ablation, SiNP@SiO₂ fragmentation, and Au ablation, all conducted in a liquid environment. The resulting AuNP@SiO₂ were characterized using transmission electron microscopy (TEM), UV–Vis absorption spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and zeta potential measurements. The results demonstrated that the AuNP@SiO₂ nanoparticles exhibit high colloidal stability, with a notably negative zeta potential of (-72.0 ± 0.3) mV, effectively preventing particle aggregation. TEM analysis confirmed predominantly spherical nanoparticles with an average diameter of (15.87 ± 0.70) nm, encapsulated by a SiO₂ layer ranging from 1 to 3 nm in thickness. The synthesis approach produced nanoparticles with an average size distribution below 35 nm. This green synthesis method not only produces stable and well-characterized AuNP@SiO₂ nanoparticles but also represents a significant step towards more sustainable nanomaterial production, with promising implications for biomedical applications.

We demonstrate unprecedented control and enhancement of thermal radiation using subwavelength conical membranes of silicon nitride. Based on fluctuational electrodynamics, we find that the focusing of surface phonon-polaritons along these membranes enhances their far-field thermal conductance by three orders of magnitude over the blackbody limit. Our calculations reveal a non-monotonic dependence of the thermal conductance on membrane geometry, with a characteristic radiation plateau emerging at small front widths due to competing effects of the polariton focusing and radiative area. The obtained results thus introduce the conical geometry as a powerful degree of freedom for tailoring thermal radiation, with potential implications for energy harvesting and thermal management at the nanoscale.

Diabetic wounds with chronic infections present a significant challenge, exacerbated by the growing issue of antimicrobial resistance, which often leads to delayed healing and increased morbidity. This study introduces a novel silver-zinc oxide-eugenol (Ag+ZnO+EU) nanocomposite, specifically designed to enhance antimicrobial activity and promote wound healing. The nanocomposite was thoroughly characterized using advanced analytical techniques, confirming its nanoscale structure, stability and chemical composition. The Ag+ZnO+EU nanocomposite demonstrated potent antimicrobial efficacy against a range of wound associated pathogens, including standard and clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Minimum inhibitory concentrations of Ag+ZnO+EU for standard and clinical isolates were significantly lower than those of the individual components, highlighting the synergistic effect of the nanocomposite. Time-kill assays revealed rapid microbial eradication, achieving complete sterility within 240-min. Importantly, the nanocomposite effectively eliminated persister-like cells, which are typically resistant to conventional treatments, suggesting a potential solution for persistent infections. In vitro scratch assays using human keratinocyte cells demonstrated that the Ag+ZnO+EU nanocomposite significantly accelerated wound closure, with near-complete healing observed within 24-h, indicating enhanced cell migration and tissue regeneration. Additionally, the nanocomposite showed potential antidiabetic effects by increasing glucose uptake up to 97.21% in an in vitro assay using 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose, a fluorescent glucose analog, suggesting potential applications beyond wound healing. These findings highlight the Ag+ZnO+EU nanocomposite as a promising candidate for addressing both antimicrobial resistance and impaired wound healing in diabetic contexts.

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