1,720,973 research outputs found
A Preliminary Propagation Study on Magnetic Scaffolds for Microwave Theranostics
Full text linkMicrowave hyperthermia is a promising therapeutic modality in oncology against deep-seated tumors such as bone cancers. However, antennas and radiating sources fails in providing the therapeutic heat without affecting the healthy tissues. Magnetic nanocomposite biomaterials, called magnetic scaffolds, can be implanted to be used as hyperthermia agents. The possibility of using magneto-dielectric biocompatible implant for performing microwave hyperthermia has been poorly investigated. Furthermore, the possibility of using magnetic scaffolds as microwave-responsive theranostic agents has never been explored. In other words, if and how the change of magnetic properties during the hyperthermia treatment could be detected by using microwave signal has been not investigated so far. In this work, a simplified mono-dimensional electromagnetic propagation model in a multilayer structure by means of the wave-amplitude transmission method has been proposed. The properties of the bolus-matching medium, a suitable set of working frequency for performing the hyperthermia treatment and the monitoring with microwaves has been found. The temperature increase in the tumor and scaffold have been simulated. Then, through the differential analysis of the variation of the transmission coefficient during the treatment it has been preliminarily determined that magnetic scaffolds could be used as microwave theranostic agents
Modelling of Magnetic Scaffolds for RF Hyperthermia of Deep-Seated Tumors
No full textDeep seated tumors are neoplasms grown in challenging sites that call for innovative interventional strategies. Thanks to the development of magnetic nanocomposite biomaterials, multifunctional electromagnetic-responsive thermoseeds, called magnetic scaffolds, can be used as hyperthermia agents to control the local recurrence rate of deep-seated cancers through radiofrequency (RF) heating. To achieve an effective and high-quality treatment, the planning through multiphysics simulations is mandatory. A computational framework for solving the coupled electromagnetic and thermal phenomena ruling the RF heating of magnetic scaffolds will be presented and used to study different biomaterials, physiopathological scenarios and applications
The First (of a Long Series) Nano Student Design Competition
No full textThe IEEE Nanotechnology Council (NTC) has marked its 25th anniversary by fostering educational initiatives for students and young professionals. Among these efforts, the Nano Student Design Competition (Nano SDC) was introduced during the 24th IEEE International Conference on Nanotechnology (IEEE NANO 2024) in Gijon, Spain. Nano SDC is a platform for student teams to design practical solutions to challenges in nanoscience and nanotechnology, guided by NTC Technical Committees. Participants showcase their prototypes, software, or methodologies at the conference, fostering innovation and collaboration. The inaugural competition included awarded projects ranging from flexible graphene-based infrared photodetectors to software for graphene fabrication, with winners gaining opportunities to publish their work in the IEEE Nanotechnology Magazine. Building on its success, Nano SDC is set to become a recurring highlight of IEEE NANO conferences, aiming to enhance student participation and create a sustainable, dynamic network within the nanotechnology community. The next edition will take place at IEEE NANO 2025 in Washington, D.C., continuing its mission to inspire and engage the next generation of nanotechnologists
An in Silico Study on Nanocomposite Magnetic Implants for Microwave Cancer Theranostics
No full textMicrowave (MW) hyperthermia (HT) is a novel cancer therapy to treat deep-seated tumors, such as bone cancers. The heat administration can be troublesome if external antennas are used. So, magnetic nanocomposite biomaterials, termed magnetic scaffolds, have been proposed as local thermo-seeds for controlling local recurrence rate of bone tumors. However, the possibility of using magneto-dielectric biocompatible implant as MW-responsive theranostic agents has poorly been assessed. In this work, an in silico study based on a 1D MW propagation model in a multilayer structure has been proposed to study if magnetic scaffolds can be used to perform and, contemporary, monitor the HT. The numerical study identified that a matching medium of relative dielectric permittivity of 40 would enables sufficient signal transmission at the frequencies of 0.434, 1.25, 2.45 and 5.8 GHz, thus enabling the HT and the MW monitoring. Indeed, by performing a differential analysis of the variation of the transmission coefficient during the HT, it has been assessed the possibility of using magnetic scaffolds as MW theranostic agents
Assessing the Carasau Bread Doughs Microwave Spectra
Full text linkCarasau bread (CB) is a traditional Sardinian flatbread with significant market potential, driving the need for advanced quality monitoring solutions in its production. Recent advancements in automation and engineering have enhanced process control, but a comprehensive understanding of CB dough properties remains essential. Dielectric spectroscopy (DS), particularly in the microwave (MW) range, has emerged as a non-destructive, cost-effective tool for food characterization, providing insights into microstructure and composition. MW DS has been applied to assess fermentation dynamics and ingredient influence in CB doughs, with previous studies modeling dielectric properties using a third-order Cole–Cole model up to 8.5 GHz and later extending to 20 GHz. Despite these advancements, the repeatability, reliability, and consistency of MW DS measurements on CB doughs have not been systematically assessed. This study aims to fill this gap by analyzing MW DS measurements on ten CB dough samples with standard composition (water 50%, yeast 1.5%, salt 1.5%) in the 0.5–6 GHz range, both before and after leavening, for 10 different samples and a total of 100 measurements. Even though the correlation between spectra is high, and even if the coefficient of variation is below 5% before leavening, the z-score analysis and the kernel density estimation highlighted that the distribution of dielectric data is heterogeneous, showing that variability across samples exists, especially after leavening. Finally, the influence of pressure, temperature, and relative humidity was excluded. This statistical evaluation of MW DS measurement provided critical insights into the robustness of MW DS for industrial applications
A Microwave Imaging Technique Based on Artificial Neural Networks for Neck Tumors Detection
No full textA microwave imaging approach for the detection of neck tumors is proposed in this paper. Specifically, a preliminary artificial neural network (ANN) is adopted for the reconstruction of the properties of a cross section of the neck starting from scattered electric fields. To this end, realistic neck phantoms are developed to test the feasibility of the proposed method. Several test cases are performed to evaluate the performance of the ANN to discriminate different sizes of the tumor and different positions inside the neck. The preliminary results indicate quite good detection capabilities
Microwave tomography of the neck with ANNs: Preliminary results with simplified numerical phantoms
No full textA microwave imaging approach based on artificial neural networks (ANNs) for the reconstruction of the properties of a cross section of the neck is proposed in this paper. The aim of this work is to retrieve the distribution maps of the neck dielectric properties starting from electromagnetic scattered fields. Possible applications include the diagnosis of cervical diseases. To this end, simplified neck phantoms were developed to test the feasibility of the proposed method. The developed network presents four fullyconnected layers with a last regression layer. Several numerical tests were performed to evaluate the performance of the ANN. The preliminary findings indicate a quite good reconstruction of dielectric properties and the possibility to evaluate the spinal canal dimension
The first edition of the world nanotechnology marathon [Spotlight Column]
No full textShifting paradigms in teaching and learning embraced by the nanotechnology council young professional
Wideband Antennas for Cubesat Platforms: Design and Multiphysics Analysis
Full text linkThe paradigm of new space economy is demanding for innovative, cost-effective solutions to enable future missions. To this aim, CubeSat platforms proved to play a key role. The communication sub-system is crucial for these nanosatellites, and the antenna is the core element. To push the forefront, the challenging field of CubeSat antennas design demands for innovative design methodologies, new materials and disruptive manufacturing approaches, such as additive manufacturing. Considering specific mission requirements, combined with the harsh space environment, a given antenna layout must effectively perform. To this aim, multiphysics simulations can help in discriminating between different design, while favoring the understanding of potential risky situations. This work deals with the presentation of methodologies for designing innovative antennas for CubeSat applications. In particular, a 3D-printed curved stacked patch antenna working in the S-band and a stacked patch antenna array working in the Ka-band will be presented. The electromagnetic performances of the antennas have been studied with a numerical multiphysics model considering the thermal and mechanical variations during a simulated CubeSat mission
Control of electronic band profiles through depletion layer engineering in core–shell nanocrystals
Full text linkFermi level pinning in doped metal oxide (MO) nanocrystals (NCs) results in the formation of depletion layers, which affect their optical and electronic properties, and ultimately their application in smart optoelectronics, photocatalysis, or energy storage. For a precise control over functionality, it is important to understand and control their electronic bands at the nanoscale. Here, we show that depletion layer engineering allows designing the energetic band profiles and predicting the optoelectronic properties of MO NCs. This is achieved by shell thickness tuning of core-shell Sn:In2O3-In2O3 NCs, resulting in multiple band bending and multi-modal plasmonic response. We identify the modification of the band profiles after the light-induced accumulation of extra electrons as the main mechanism of photodoping and enhance the charge storage capability up to hundreds of electrons per NC through depletion layer engineering. Our experimental results are supported by theoretical models and are transferable to other core-multishell systems as well.Surface states, and the combination of suitable materials, induce spatial gradients in the carrier density of doped metal oxide nanocrystals, affecting their electronic structure and plasmonic behavior. Here the authors demonstrate depletion layer engineering and control in ITO/In2O3 core-shell nanocrystals by tuning the shell thickness or by photodoping
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