Nanotechnology最新文献

Colon cancer is one of the leading cancers worldwide, with standard treatments hindered by inadequate targeting and toxicities that limit dosage. Nanotechnology offers a revolutionary framework for targeted drug delivery, utilizing nanoscale effects to improve treatment accuracy. This examination focuses on chitosan nanoparticles (CNPs) as innovative nanocarriers, leveraging their unique nanoscale features like sizes between 50-300 nm, elevated surface-to-volume ratios, and positive zeta potentials (+20 to +50 mV) to facilitate mucoadhesive interactions and improved passage through biological barriers. We emphasize novel synthesis methods, such as ionic gelation utilizing tripolyphosphate for creating particles under 100 nm and eco-friendly techniques with plant extracts for sustainable scalability, enabling accurate regulation of polydispersity indices (<0.2) and drug encapsulation efficiencies (>80%). Functionalization of surfaces with ligands (such as folate or hyaluronic acid) promotes receptor-mediated endocytosis, leveraging quantum confinement-like effects in surface charge distribution to enhance cellular uptake in colon cancer receptors that are overexpressed. Preclinical findings demonstrate stimulus-responsive actions, including pH-activated disassembly in the acidic tumour milieu (pH 5.5-6.5) or enzyme-facilitated release by colonic glycosidases, resulting in prolonged drug payloads (like 5-fluorouracil or curcumin) with 2-5 times greater bioavailability and minimized off-target impacts. Incorporating magnetic or fluorescent elements allows for multifunctional theranostics that merge nanoscale imaging with therapeutic applications. Despite challenges in mass production and in vivo stability, continuous progress in nanoscale enhancements is set to close preclinical gaps, establishing CNPs as a fundamental element for future colon cancer treatments through quantum-inspired precision and biocompatibility.

As CMOS technology scales into the nanoscale regime, ensuring the reliability of digital circuits in radiation-rich environments has become a critical challenge. Standard cell libraries, foundational to digital design, are typically characterized using extensive SPICE simulations to capture gate delays as functions of input transition time and load capacitance. However, these libraries do not account for Total Ionizing Dose (TID) effects, which are caused by prolonged exposure to ionizing radiation and introduce oxide-trapped charges and interface states that degrade key transistor parameters, such as threshold voltage and leakage current. This results in significant timing inaccuracies, compromising digital timing closure in mission-critical applications such as aerospace and nuclear electronics. In this work, we propose an efficient, TID-aware standard cell characterization methodology for nanoscale CMOS technologies that generates cell characterization data in standard Liberty format, enabling accurate prediction of timing closure under TID influence without incurring any SPICE simulation overhead. Our approach leverages well-calibrated 32 nm Synopsys© Sentaurus TCAD simulations and variation-aware analytical timing models to capture TID-induced degradation. These effects are incorporated into cell netlists through adjustments to the BSIM parameters to generate both pre- and post-radiation standard cell libraries. Validated using a set of reference designs including ISCAS benchmark circuits, the methodology achieves accurate path-level timing predictions under radiation while reducing SPICE simulation effort by approximately 81.25%. By bridging device-level radiation effects with cell-level timing abstraction, this scalable framework offers a practical solution for robust and radiation-resilient digital integrated circuit design in harsh environments.

Heat transfer from a liquid-vapor phase change is widely used in industry for thermal management. Improving the heat transfer efficiency of the phase change could yield substantial energy savings and reduce greenhouse emissions. In this work, the heat transfer performance of a nanoporous Teflon surface was tested using droplet vaporization experiments with acetone as the working fluid. The nanoporous surface was heated to various temperatures and the vaporization process was recorded using a digital camera at a high motion frame rate of 60 fps. The time required to vaporize a given volume of acetone and the area of the droplet on the surface were used to calculate the heat flux. The nanoporous surface demonstrated 1.8× enhanced heat transfer and 2.8× faster vaporization rates than a flat Teflon surface for the same liquid volume.

Chiral optical metasurfaces have emerged as a promising platform in coupling with molecular vibrational fingerprints through the enhanced light-matter interaction under different circularly polarized light illumination. This work reports the mode coupling between the mid-infrared phonon vibrations of polymethyl methacrylate (PMMA) molecules and the thermally tunable chiral metasurfaces based on the phase-change material Ge₂Sb₂Te₅ (GST-225). Phase-change chiral metasurfaces with high circular dichroism (CD) in absorption and tunable plasmonic resonance in the frequency range of 48-56 THz are demonstrated, which covers the phonon vibrational frequency of PMMA molecules at 52 THz. The mode splitting features are observed in the absorption and CD spectra when the metasurface resonance is tuned across the phonon vibrational frequency of PMMA molecules during the phase transition of GST-225. The underlying mechanism of molecule-metasurface coupling is further revealed by studying the electric field and power loss density distributions of the phonon-plasmon coupled modes under both left-handed and right-handed circularly polarized (LCP and RCP) light. The demonstrated results show the potential of dynamically tunable chiral metasurfaces for the applications in label-free molecular sensing, biomedical diagnostics, thermal imaging, and mid-infrared photonics.

Memristors with multilevel storage capabilities have emerged as promising candidates for high-density memory and neuromorphic computing systems. In this study, a trilayer-structured memristor with an Al₂O₃/HfO₂/Al₂O₃(3/14/3 nm) dielectric stack was fabricated via atomic layer deposition, sandwiched between Ti and Pt electrodes. The analog switching characteristics of the memristor were systematically investigated through two strategies: adjusting the compliant current (I_cc) during the SET process and controlling the RESET-stop voltage (V_RESET-stop) in the RESET process. The experimental results indicate thatI_ccprimarily modulates the values of low resistance states, whereasV_RESET-stopmainly influences the values of high resistance states. To validate multilevel storage feasibility,I_ccvalues of 0.5, 1, 2.5, and 5 mA andV_RESET-stopvoltages of 1.5, 1.7, 2, and 2.3 V were systematically applied. Statistical analysis demonstrated thatV_RESET-stopmodulation yields more stable and repeatable resistance states compared toI_cctuning. Furthermore, the continuous resistance (or conductance) tuning capability of our fabricated memristor emulates neural network weight updates. This allows trained weights to be directly mapped to the memristor's conductance states, achieving 91.6% accuracy in handwritten digit recognition. This work underscores the significant potential of the Al₂O₃/HfO₂/Al₂O₃trilayer-structured memristor for high-performance multilevel storage and neuromorphic computing applications.

Metal nanoclusters (NCs) with aggregation-induced emission (AIE) characteristics have garnered substantial interest due to their intense photoluminescence and extensive potential applications. Elucidating the mechanisms underlying their high-efficiency luminescence is critical for advancing high-performance luminescent metal NCs materials. In recent years, Au(0)@Au(I)-thiolate NCs featuring core-shell architectures have demonstrated exceptional luminescent properties, offering an attractive strategy for engineering highly emissive Au NCs. This study presents a facile method for synthesizing novel green-emitting homocysteine stabilized Au NCs (Hcy-Au NCs) with core-shell structure. The critical mechanistic feature involves precisely controlled HCl etching of Au(I)-thiolate complexes, driving their decomposition to generate the Au(0) cores essential for the core-shell structures, thereby enabling the formation of luminescent Hcy-Au NCs. This convenient one-pot methodology demonstrates remarkable versatility, having been successfully extended beyond the preparation of luminescent Hcy-Au NCs and glutathione stabilized Au NCs (GSH-Au NCs) to include the synthesis of luminescent cysteine stabilized Au NCs (Cys-Au NCs) and D-Penicillamine stabilized Au NCs (DPA-Au NCs). Our work provides valuable insights for developing novel highly luminescent metal NCs.

The development of photocatalysts that can efficiently harness low-energy photons, specifically infrared light, for CO₂reduction remains a formidable challenge. Plasmonic semiconductors emerge as promising candidates, addressing the inherent issues of charge recombination and energy loss encountered in single-phase semiconductors. Here, we grow a plasmonic p-Cu₇S₄/n-CdS heterojunction directly onto a single CdS nanoparticle by ion exchange. The resulting plasmonic p-Cu₇S₄/n-CdS heterojunction exhibits a highly efficient photocatalytic reduction property for converting CO₂into CO, CH₄, and C₂H₄when excited solely under near-infrared light irradiation. In a gas-solid configuration using CO₂with water vapor as the sole electron donor (no sacrificial agents), the CO production rate reaches 86.4μmol g^-1h^-1, ∼63-fold that of Cu₇S₄ alone. Our work not only represents a groundbreaking advancement in the realm of infrared light-driven photocatalysts but also showcases the potential of plasmonic semiconductors for practical applications.

A number of ecological stressors negatively impact on rice yield, drastically lowering crop productivity. Among these, arsenic stress is considered a major abiotic factor that affects number of processes in plants, ultimately leading to reduced productivity. Nano-hormonal interactions have garnered allure as a possible way to lessen arsenic toxicity in plants. In this work, the synergistic effects of zinc oxide nanoparticles (ZnO-NPs) and epibrassinolide (EBL) on rice (Oryza sativa) with arsenic stress were examined. A fully randomized block design was used in a pot experiment. Exposure to arsenic (150 μM) impaired growth (length and biomass), photosynthetic performance, soluble sugars, starch, and sucrose (primary metabolites), phenolics and flavonoids (secondary metabolites), as well as key mineral nutrients. However, foliar application of ZnO-NPs (100 mg/L) and EBL (0.01 μM) alleviated arsenic-induced toxicity by promoting enzymes activity and promoting the involvement of secondary metabolites in defense. These improvements in the biochemical and physiological matrices of rice plants effectively mitigated growth losses under arsenic stress. Overall, this work concludes the interactions between ZnO-NPs and EBL in modulating development and growth in rice, thereby contributing to global food security.

We report a breakthrough in contact engineering that overcomes the long-standing fin-pitch (FP) bottleneck, enabling FinFET scaling to sub-3 nm nodes, including feasibility at the 10 Å node. We propose an I-shaped source/drain (S/D) architecture for FinFETs to replace the conventional diamond-shaped S/D, minimizing lateral protrusion while preserving the electrical performance. Calibrated 3D technology computer-aided design simulations show that, despite the reduced contact area, the proposed design sustains-or even improves-ON-state current with comparable subthreshold swing relative to conventional counterparts. Under fixed cell-area targets representative of the 2 nm node, coordinated co-optimization of contacted poly pitch (CPP) and FP reallocates the FP-liberated area margin to moderate CPP expansion, which in turn enables gate-length extension, stronger electrostatic control, and robust suppression of short-channel effects. Sensitivity analyses across realistic specific contact resistivity confirm process-window robustness. Collectively, these results decouple FP scaling from S/D geometry and establish a manufacturing-friendly path to sub-3 nm FinFETs without wholesale architectural changes, such as a transition to gate-all-around architectures.

This study reports a template-free hydrothermal synthesis of zeolite nanocrystals with controllable phase and composition. The controlled formation of sodalite (SOD) nanocrystals was primarily achieved through temperature modulation. Phase transitions in zeolite nanocrystals exhibited significant temperature dependence, sequentially yielding zeolite a, hydroxy-SOD, and cancrinite (CAN) as hydrothermal temperatures increased from 50 °C to 160 °C. Notably, hydroxy-SOD with consistent polyhedral morphology was obtained across a broad temperature range (60 °C-150 °C). Furthermore, a two-step synthesis strategy enabled the construction of hydroxy-SOD-CAN heterojunctions with tunable phase ratios in mixed crystals, demonstrating 38% higher CAN yield compared to single-step process. The crystallization mechanisms involve temperature-dependent assembly of [AlO4] and [SiO4] structural units, with phase transformation from hydroxy-SOD to CAN initiating at surface active sites. The hydroxy-SOD nanocrystals exhibit excellent nitrogen adsorption capacity, reaching up to 266 cm³g^-1.