Nanotechnology最新文献

In the post-lithium-ion battery era, potassium-ion batteries (PIBs) have been considered as a promising candidate because of their electrochemical and economic characteristics. However, as an emerging electrochemical storage technology, it is urgent to develop capable anode materials that can be produced at low cost and on a large scale to promote its practical application. Biomass-derived carbon materials as anodes of PIBs exhibit strong competitiveness by their merits of low weight, high stability, non-toxicity, and wide availability. In this work, we employed Platanus occidentalis L. fruits as a precursor to prepare a series of biomass-derived carbon materials by simply adjusting carbonization temperature, and we explored their electrochemical potassium storage capability as anode materials. The optimized sample (annealed at 800 °C) delivered good potassium storage capability (193.3 mAh g^-1at 100 mA g^-1after 100 cycles), cycling stability (80.4 mAh g^-1after 300 cycles at 300 mA g^-1), and rate performance (51.2 mAh g^-1at 1000 mA g^-1). This work demonstrates a feasible way to utilize biomass waste disposal for emerging sustainable energy storage technologies.

This study investigates the enhancement of damping properties in carbon fiber-reinforced polymer (CFRP) composites by incorporating graphene nanoplatelets (GNPs) into the epoxy matrix. Epoxy and CFRP specimens with varying GNP concentrations, were developed and tested through free vibration experiments to measure damping ratios. Additionally, a computational model based on the finite element method was developed to simulate the damping behavior of these hybrid nanocomposites. Using periodic representative volume elements under sinusoidal axial loads, the model accurately predicted damping performance by calculating the time lag between applied loads and resulting deformations. Comparison of numerical results with experimental data revealed a strong correlation, confirming the model's effectiveness in capturing the influence of GNP mass fraction on damping enhancement.

Quasi-two-dimensional nanosheets exhibit novel properties and promising applications in optoelectronic flexible devices. Research on non-layered III-V semiconductor nanosheets has been constrained by their covalent bonding connections. In this study, GaAs/AlGaAs heterojunction nanosheets were prepared by releasing an epitaxial layer, and their optical properties were investigated by adopting steady-state and transient absorption spectroscopy. The optical properties of the independent GaAs/AlGaAs heterojunction were investigated separately in order to exclude the effect of the substrate. This work provides a comprehensive understanding of the physics of III-V semiconductor quasi-two-dimensional nanosheets. .

In the published article "Silver nanoparticles directly formed on natural macroporous matrix and their anti-microbial activities, Nanotechnology 18 (2007) 055605", the figure caption of Figure 8 has an error in immersion time, and the correct caption is given in this Corrigendum.

Significant progress has been made in cancer therapy with protein-based nanocarriers targeted directly to surface receptors for drug delivery. The nanocarriers are a potentially effective solution for the potential drawbacks of traditional chemotherapy, such as lack of specificity, side effects, and development resistance. Peptides as nanocarriers have been designed based on their biocompatible, biodegradable, and versatile functions to deliver therapeutic agents into cancer cells, reduce systemic toxicity, and maximize therapy efficacy through utilizing targeted ligands such as antibodies, amino acids, vitamins, and other small molecules onto protein-based nanocarriers and thus ensuring that drugs selectively accumulate in the cancer cells instead of healthy organs/drug release at a target site without effects on normal cells, which inherently caused less systemic toxicity/off-target effect. Moreover, their intrinsic protein backbone naturally degrades in vivo, providing another level of safety over synthetic materials. Various issues like immunogenicity, mass production, and quality control must be addressed for widespread use. However, further studies are necessary to perfect protein engineering and improve drug loading, protein modification, and targeting. Thus, it can be concluded that protein-based nanocarriers targeted against the surface receptors would help achieve cancer management in a more focused manner, thus minimizing toxicity. The further development of these nanoparticles could bring a significant change in cancer treatment so that more personalized, targeted, and safe therapies would be available to all patients.

We investigate the effect of focused-ion-beam (FIB) irradiation on spin waves with sub-micron wavelengths in Yttrium-Iron-Garnet (YIG) films. Time-resolved scanning transmission X-ray (TR-STXM) microscopy was used to image the spin waves in irradiated regions and deduce corresponding changes in the magnetic parameters of the film. We find that the changes of Ga⁺irradiation can be understood by assuming a few percent change in the effective magnetizationM_effof the film due to a trade-off between changes in anisotropy and effective film thickness. Our results demonstrate that FIB irradiation can be used to locally alter the dispersion relation and the effective refractive indexn_effof the film, even for submicron wavelengths. To achieve the same change inn_efffor shorter wavelengths, a higher dose is required, but no significant deterioration of spin wave propagation length in the irradiated regions was observed, even at the highest applied doses.

To implement a neuromorphic computing system capable of efficiently processing vast amounts of unstructured data, a significant number of synapse and neuron devices are needed, resulting in increased area demands. Therefore, we developed a nanoscale vertically structured synapse device that supports high-density integration. To realize this synapse device, the interface effects between the resistive switching layer and the electrode were investigated and utilized. Electrical and physical analyses were conducted to comprehend the operational mechanism of the developed synapse device. The results indicate that oxygen ions from the resistive switching layer were absorbed by the electrode, forming metal-oxygen bonds. The V_oconcentration in the switching layer that can change the total conductance of the device. To assess its potential as a synapse device in the neuromorphic system, the developed device was evaluated through pattern recognition simulation.

Glioblastoma (GBM) is a malignant tumor with highly heterogeneous and invasive characteristics leading to a poor prognosis. The CD44 molecule, which is highly expressed in GBM, has emerged as a highly sought-after biological marker. Therapeutic strategies targeting the cell membrane protein CD44 have emerged, demonstrating novel therapeutic potential. In this study, we constructed a nanodrug system (HA-Liposome@Dox) based on hyaluronic acid-engineered liposomes delivering adriamycin to target GBM. The system efficiently encapsulated Dox inside the liposomes through a hydrophilic-hydrophobic interaction mechanism, and the resulting HA-Liposome@Dox exhibited excellent loading efficacy, attributed to its uniform particle size distribution and negatively charged surface. Further evaluation revealed that HA-Liposome@Dox possessed excellent stability and safety and could promote the effective uptake of drug particles by CD44-overexpressing tumor cells, thus exerting a more potent cell-killing effect. Notably, in the treatment of GBM, HA-Liposome@Dox demonstrated significantly greater tumor growth inhibition compared to free Dox and prolonged the survival of tumor-bearing mice. Taken together, the present study not only verified the feasibility of HA-Liposome@Dox as an effective therapeutic tool against GBM and other CD44-positively expressing tumors, but also opened a promising new avenue for the clinical treatment of this type of refractory malignancies. .

Stochastic neurons are extremely efficient hardware for solving a large class of problems and usually come in two varieties - "binary" where the neuronal state varies randomly between two values of ±1 and "analog" where the neuronal state can randomly assume any value between -1 and +1. Both have their uses in neuromorphic computing and both can be implemented with low- or zero-energy-barrier nanomagnets whose random magnetization orientations in the presence of thermal noise encode the binary or analog state variables. In between these two classes is n-ary stochastic neurons, mainly ternary stochastic neurons (TSN) whose state randomly assumes one of three values (-1, 0, +1), which have proved to be efficient in pattern classification tasks such as recognizing handwritten digits from the MNIST data set or patterns from the CIFAR-10 data set. Here, we show how to implement a TSN with a zero-energy-barrier (shape isotropic) magnetostrictive nanomagnet subjected to uniaxial strain.

The growing world population and climate change are key drivers for the increasing pursuit of more efficient and environmentally-safe food production. In this scenario, the large scale use of herbicides demands the development new technologies to control and monitor the application of these compounds, due to their several environmental and health-related problems. Motivated by all these issues, in this work, a hybrid graphene/boron nitride nanopore is explore to detect/identify herbicide molecules (Glyphosate, AMPA, Diuron, and 2,4-D). Solid-state nanopores based on 2D materials have been widely explored as novel generation sensors capable of single-molecule resolution. The present investigation combines the density functional theory (DFT) and non-equilibrium Green's function (NEGF) method to assess the interaction of each herbicide with the nanopore and how its interaction modulates the device's electronic transport properties. The device's sensitivity spreads from 9.0 up to 27.0% when probed at different gate voltage values. Overall, the proposed device seems to be sensitive and selective to be considered as a promising single-molecule herbicide sensor.