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1.
Phys Rev Lett ; 132(11): 116701, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38563939

ABSTRACT

Cavity magnonics is an emerging research area focusing on the coupling between magnons and photons. Despite its great potential for coherent information processing, it has been long restricted by the narrow interaction bandwidth. In this Letter, we theoretically propose and experimentally demonstrate a novel approach to achieve broadband photon-magnon coupling by adopting slow waves on engineered microwave waveguides. To the best of our knowledge, this is the first time that slow wave is combined with hybrid magnonics. Its unique properties promise great potentials for both fundamental research and practical applications, for instance, by deepening our understanding of the light-matter interaction in the slow wave regime and providing high-efficiency spin wave transducers. The device concept can be extended to other systems such as optomagnonics and magnomechanics, opening up new directions for hybrid magnonics.

2.
Sci Rep ; 13(1): 14643, 2023 09 05.
Article in English | MEDLINE | ID: mdl-37669995

ABSTRACT

The field of wireless communication has witnessed tremendous advancements in the past few decades, leading to more pervasive and ubiquitous networks. Human bodies are continually exposed to electromagnetic radiation, but typically this does not impact the body as the radiation is non-ionizing and the waves carry low power. However, with progress in the sixth generation (6G) of wireless networks and the adoption of the spectrum above 100 GHz in the next few years, higher power radiation is needed to cover larger areas, exposing humans to stronger and more prolonged radiation. Also, water has a high absorption coefficient at these frequencies and could lead to thermal effects on the skin. Hence, there is a need to study the radiation effects on human tissues, specifically the photothermal effects. In this paper, we present a custom-built, multi-physics model to investigate electromagnetic wave propagation in human tissue and study its subsequent photothermal effects. The proposed finite-element model consists of two segments-the first one estimates the intensity distribution along the beam path, while the second calculates the increase in temperature due to the wave distribution inside the tissue. We determine the intensity variation in the tissue using the radiative transfer equation and compare the results with Monte Carlo analysis and existing analytical models. The intensity information is then utilized to predict the rise in temperature with a bio-heat transfer module, powered by Pennes' bioheat equation. The model is parametric, and we perform a systematic photothermal analysis to recognize the crucial variables responsible for the temperature growth inside the tissue, particularly for terahertz and near-infrared optical frequencies. Our numerical model can serve as a benchmark for studying the high-frequency radiation effects on complex heterogeneous media such as human tissue.


Subject(s)
Benchmarking , Communication , Humans , Animals , Culture , Estrus , Hot Temperature
3.
Nat Commun ; 14(1): 841, 2023 Feb 15.
Article in English | MEDLINE | ID: mdl-36792611

ABSTRACT

The field of sub-terahertz wireless communications is advancing rapidly, with major research efforts ramping up around the globe. To address some of the significant hurdles associated with exploiting these high frequencies for broadband and secure networking, systems will require extensive new capabilities for sensing their environment and manipulating their broadcasts. Based on these requirements, a vision for future wireless systems is beginning to emerge. In this Perspective article, we discuss some of the prominent challenges and possible solutions which are at the forefront of current research, and which will contribute to the architecture of wireless platforms beyond 5G.

4.
Sci Rep ; 12(1): 10971, 2022 Jun 29.
Article in English | MEDLINE | ID: mdl-35768465

ABSTRACT

One of the key distinctions between legacy low-frequency wireless systems and future THz wireless transmissions is that THz links will require high directionality, to overcome the large free-space path loss. Because of this directionality, optical phenomena become increasingly important as design considerations. A key example lies in the strong dependence of angular radiation patterns on the transmission frequency, which is manifested in many different situations including common diffraction patterns and the emission from leaky-wave apertures. As a result of this effect, the spectral bandwidth at a receiver is nonlinearly dependent on the receiver's angular position and distance from the transmitter. In this work, we explore the implications of this type of effect by incorporating either a diffraction grating or a leaky wave antenna into a communication link. These general considerations will have significant implications for the robustness of data transmissions at high frequencies.

5.
Nano Lett ; 22(7): 2674-2681, 2022 04 13.
Article in English | MEDLINE | ID: mdl-35312324

ABSTRACT

Terahertz (THz) plasma oscillations represent a potential path to implement ultrafast electronic devices and circuits. Here, we present an approach to generate on-chip THz signals that relies on plasma-wave stabilization in nanoscale transistors with specific structural asymmetry. A hydrodynamic treatment shows how the transistor asymmetry supports plasma-wave amplification, giving rise to pronounced negative differential conductance (NDC). A demonstration of these behaviors is provided in InGaAs high-mobility transistors, which exhibit NDC in accordance with their designed asymmetry. The NDC onsets once the drift velocity in the channel reaches a threshold value, triggering the initial plasma instability. We also show how this feature can be made to persist beyond room temperature (to at least 75 °C), when the gating is configured to facilitate a transition between the hydrodynamic and ballistic regimes (of electron-electron transport). Our findings represent a significant step forward for efforts to develop active components for THz electronics.


Subject(s)
Transistors, Electronic
6.
Light Sci Appl ; 9: 179, 2020.
Article in English | MEDLINE | ID: mdl-33101659

ABSTRACT

On-chip integrated laser sources of structured light carrying fractional orbital angular momentum (FOAM) are highly desirable for the forefront development of optical communication and quantum information-processing technologies. While integrated vortex beam generators have been previously demonstrated in different optical settings, ultrafast control and sweep of FOAM light with low-power control, suitable for high-speed optical communication and computing, remains challenging. Here we demonstrate fast control of the FOAM from a vortex semiconductor microlaser based on fast transient mixing of integer laser vorticities induced by a control pulse. A continuous FOAM sweep between charge 0 and charge +2 is demonstrated in a 100 ps time window, with the ultimate speed limit being established by the carrier recombination time in the gain medium. Our results provide a new route to generating vortex microlasers carrying FOAM that are switchable at GHz frequencies by an ultrafast control pulse.

7.
Opt Lett ; 45(20): 5744-5747, 2020 Oct 15.
Article in English | MEDLINE | ID: mdl-33057274

ABSTRACT

Epsilon-near-zero (ENZ) materials display unique properties, and among them, large local field enhancement at ENZ frequency is of particular interest for many potential applications. In this Letter, we introduce the concept that a combination of epsilon-near-zero and surface plasmon polariton modes can be excited over an interface between a dielectric and a single ENZ layer in a specific frequency region, which can lead to extreme enhancement of local electric field. We demonstrate it with a systematic numerical simulation using finite element analysis and consider two configurations (Kretschmann configuration and a grating configuration), where an indium tin oxide (ITO) layer is sandwiched between two dielectric slabs. We confirm the formation of a hybrid mode at the ITO-dielectric interface at the wavelength of ENZ, as the ITO layer thickness reduces. The hybrid mode provides both high confinement and long propagation distance, which makes it more attractive for many applications than just a pure ENZ mode.

8.
Int J Mol Sci ; 22(1)2020 Dec 31.
Article in English | MEDLINE | ID: mdl-33396256

ABSTRACT

During the development of mouse embryonic stem cells (ESC) to neuronal committed cells (NCC), coordinated changes in the expression of 2851 genes take place, mediated by the nuclear form of FGFR1. In this paper, widespread differences are demonstrated in the ESC and NCC inter- and intra-chromosomal interactions, chromatin looping, the formation of CTCF- and nFGFR1-linked Topologically Associating Domains (TADs) on a genome-wide scale and in exemplary HoxA-D loci. The analysis centered on HoxA cluster shows that blocking FGFR1 disrupts the loop formation. FGFR1 binding and genome locales are predictive of the genome interactions; likewise, chromatin interactions along with nFGFR1 binding are predictive of the genome function and correlate with genome regulatory attributes and gene expression. This study advances a topologically integrated genome archipelago model that undergoes structural transformations through the formation of nFGFR1-associated TADs. The makeover of the TAD islands serves to recruit distinct ontogenic programs during the development of the ESC to NCC.


Subject(s)
CCCTC-Binding Factor/metabolism , Cell Nucleus/genetics , Chromatin/metabolism , Embryonic Stem Cells/cytology , Genome , Neurogenesis , Receptor, Fibroblast Growth Factor, Type 1/metabolism , Animals , CCCTC-Binding Factor/genetics , Cell Differentiation , Chromatin/genetics , Chromosomes/genetics , Embryonic Stem Cells/metabolism , Mice , Molecular Conformation , Receptor, Fibroblast Growth Factor, Type 1/genetics
9.
IEEE Trans Neural Syst Rehabil Eng ; 27(2): 108-117, 2019 02.
Article in English | MEDLINE | ID: mdl-30624220

ABSTRACT

Miniaturization of implantable devices is an important challenge for future brain-computer interface applications, and in particular for achieving precise neuron stimulation. For stimulation that utilizes light, i.e., optogenetics, the light propagation behavior and interaction at the nanoscale with elements within the neuron is an important factor that needs to be considered when designing the device. This paper analyzes the effect of light behavior for a single neuron stimulation and focuses on the impact from different cell shapes. Based on the Mie scattering theory, the paper analyzes how the shape of the soma and the nucleus contributes to the focusing effect resulting in an intensity increase, which ensures that neurons can assist in transferring light through the tissue toward the target cells. At the same time, this intensity increase can in turn also stimulate neighboring cells leading to interference within the neural circuits. This paper also analyzes the ideal placements of the device with respect to the angle and position within the cortex that can enable axonal biophoton communications, which can contain light within the cell to avoid the interference.


Subject(s)
Brain-Computer Interfaces , Nanotechnology , Neurons/physiology , Neurons/radiation effects , Optogenetics/methods , Photic Stimulation , Algorithms , Axons/radiation effects , Cell Shape/radiation effects , Cerebral Cortex/cytology , Cerebral Cortex/radiation effects , Humans , Light , Neural Stem Cells/radiation effects , Neural Stem Cells/ultrastructure , Neurons/ultrastructure , Scattering, Radiation
10.
Rev. Rol enferm ; 41(11/12): 757-760, nov.-dic. 2018. ilus
Article in Spanish | IBECS | ID: ibc-179767

ABSTRACT

Las quemaduras son heridas que presentan un aspecto muy diverso. Además, pueden comportar niveles de gravedad muy distintos, tratándose de heridas leves que evolucionan favorablemente en algunos casos (quemaduras «menores»), o causando graves lesiones cutáneas y trastornos sistémicos en otros (quemaduras graves o grandes quemados). Las quemaduras graves deberán ser derivadas de inmediato a unidades de quemados, mientras que las quemaduras «menores», se pueden manejar en atención primaria. No obstante, pueden presentarse algunas complicaciones, que deben prevenirse o detectarse precozmente para evitar secuelas mayores. A propósito de este caso, se mencionan algunos aspectos importantes sobre el manejo de estas lesiones en atención primaria, citando algunos errores que suelen cometerse frecuentemente y la forma de evitarlos. Destacaremos los beneficios que aportan algunos materiales modernos, que contribuyen al cierre más rápido de la herida, con lo que se obtiene un mejor resultado estético y funcional de la cicatriz resultante


Burns are wounds that have a very different appearance. In addition, they can behave very different levels of severity, in the case of minor wounds that progress favorably in some cases («minor» burns), or causing severe skin lesions and systemic disorders in others (severe burns or large burns). Serious burns should be immediately referred to burn units, while «minor» burns can be handled in primary care. However, some complications can occur, which must be prevented or detected early to avoid major sequelae. Regarding this case, some important aspects of the management of these injuries in primary care are mentioned, citing some errors that are frequently committed and how to avoid them. We will highlight the benefits provided by some modern materials, which contribute to the faster closure of the wound, which results in a better aesthetic and functional outcome of the resulting scar


Subject(s)
Humans , Adolescent , Burns/therapy , Sulfadiazine/pharmacokinetics , Bandages , Wound Closure Techniques/nursing , Wound Healing , Debridement/nursing , Treatment Outcome , Primary Health Care/methods
11.
ACS Sens ; 3(8): 1471-1479, 2018 08 24.
Article in English | MEDLINE | ID: mdl-30019892

ABSTRACT

Exosomes are small extracellular vesicles released by cells for cell-cell communication. They play important roles in cancer development, metastasis, and drug resistance. Exosomal proteins have been demonstrated by many studies as promising biomarkers for cancer screening, diagnosis, and monitoring. Among many detection techniques, surface plasmon resonance (SPR) is a highly sensitive, label-free, and real-time optical detection method. Commercial prism-based wavelength/angular-modulated SPR sensors afford high sensitivity and resolution, but their large footprint and high cost limit their adaptability for clinical settings. Recently, a nanoplasmonic exosome (nPLEX) assay was developed to detect exosomal proteins for ovarian cancer diagnosis. However, comparing with conventional SPR biosensors, the broad applications of nanoplasmonic biosensors are limited by the difficult and expensive fabrication of nanostructures. We have developed an intensity-modulated, compact SPR biosensor (25 cm × 10 cm × 25 cm) which uses a conventional SPR sensing mechanism and does not require nanostructure fabrication. Calibration from glycerol showed that the compact SPR biosensor offered sensitivity of 9.258 × 103%/RIU and resolution of 8.311 × 10-6 RIU. We have demonstrated the feasibility of the compact SPR biosensor in lung cancer diagnosis using exosomal epidermal growth factor receptor (EGFR) and programmed death-ligand 1 (PD-L1) as biomarkers. It detected a higher level of exosomal EGFR from A549 nonsmall cell lung cancer (NSCLC) cells than BEAS-2B normal cells. With human serum samples, the compact SPR biosensor detected similar levels of exosomal EGFR in NSCLC patients and normal controls, and higher expression of exosomal PD-L1 in NSCLC patients than normal controls. The compact SPR biosensor showed higher detection sensitivity than ELISA and similar sensing accuracy as ELISA. It is a simple and user-friendly sensing platform, which may serve as an in vitro diagnostic test for cancer.


Subject(s)
Biosensing Techniques/methods , Carcinoma, Non-Small-Cell Lung/diagnosis , ErbB Receptors/analysis , Exosomes/metabolism , Lung Neoplasms/diagnosis , Surface Plasmon Resonance , Aged , B7-H1 Antigen/analysis , Biomarkers, Tumor/analysis , Cell Line, Tumor , Female , Humans , Male , Middle Aged , Protein Array Analysis , Surface Properties
12.
Rev Enferm ; 29(3): 55-60, 2006 Mar.
Article in Spanish | MEDLINE | ID: mdl-16613085

ABSTRACT

The scars produced by burns have serious consequences for the patient. The repercussions go further than the discomfort, pain and physical restrictions, going as far as causing significant psychological consequences which can restrict the personal and social relationships of those affected. From the accounts told by two burn victims, and the technical analysis carried out by psychologists and psychiatrists specialised in this field, we gain a better understanding of the situation of these patients, on the basis of which we propose a series of nursing interventions designed to improve the care given in the area of wound healing.


Subject(s)
Burns/complications , Cicatrix/nursing , Cicatrix/psychology , Skin/injuries , Cicatrix/etiology , Humans
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