scholarly journals Recent Advances and Challenges in the Development of Radiofrequency HTS Coil for MRI

2021 ◽  
Vol 9 ◽  
Author(s):  
Aimé Labbé ◽  
Gilles Authelet ◽  
Bertrand Baudouy ◽  
Cornelis J. van der Beek ◽  
Javier Briatico ◽  
...  
Keyword(s):  
Low Noise ◽  
Electric Response ◽  
Field Coupling ◽  
Potential Applications ◽  
Anomalous Skin Effect ◽  
Bio Imaging ◽  
Imaging Artifacts ◽  
Magnetic Resonance Imaging Mri ◽  
User Friendly ◽  
Copper Coil

Radiofrequency (RF) coils fashioned from high-temperature superconductor (HTS) have the potential to increase the sensitivity of the magnetic resonance imaging (MRI) experiment by more than a dozen times compared to conventional copper coils. Progress, however, has been slow due to a series of technological hurdles. In this article, we present the developments that recently led to new perspectives for HTS coil in MRI, and challenges that still need to be solved. First, we recall the motivations for the implementations of HTS coils in MRI by presenting the limits of cooled copper coil technology, such as the anomalous skin effect limiting the decrease of the electric resistance of normal conductors at low temperature. Then, we address the progress made in the development of MRI compatible cryostats. New commercially available low-noise pulsed-tube cryocoolers and new materials removed the need for liquid nitrogen-based systems, allowing the design of cryogen-free and more user-friendly cryostats. Another recent advance was the understanding of how to mitigate the imaging artifacts induced by HTS diamagnetism through field cooling or temperature control of the HTS coil. Furthermore, artifacts can also originate from the RF field coupling between the transmission coil and the HTS reception coil. Here, we present the results of an experiment implementing a decoupling strategy exploiting nonlinearities in the electric response of HTS materials. Finally, we discuss the potential applications of HTS coils in bio-imaging and its prospects for further improvements. These include making the technology more user-friendly, implementing the HTS coils as coil arrays, and proposing solutions for the ongoing issue of decoupling. HTS coil still faces several challenges ahead, but the significant increase in sensitivity it offers lends it the prospect of being ultimately disruptive.

scholarly journals Tactile Interaction Sensor with Millimeter Sensing Acuity

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4274
Author(s):  
Eunsuk Choi ◽  
Sunjin Kim ◽  
Jinsil Gong ◽  
Hyeonjeong Sun ◽  
Minjin Kwon ◽  
...  
Keyword(s):  
Shear Force ◽  
High Reliability ◽  
Normal Pressure ◽  
Low Noise ◽  
Sensing Material ◽  
High Uniformity ◽  
Tactile Interaction ◽  
Force Direction ◽  
Potential Applications ◽  
Contact Shape

In this article we report on a 3 × 3 mm tactile interaction sensor that is able to simultaneously detect pressure level, pressure distribution, and shear force direction. The sensor consists of multiple mechanical switches under a conducting diaphragm. An external stimulus is measured by the deflection of the diaphragm and the arrangement of mechanical switches, resulting in low noise, high reliability, and high uniformity. Our sensor is able to detect tactile forces as small as ~50 mgf along with the direction of the shear force. It also distinguishes whether there is a normal pressure during slip motion. We also succeed in detecting the contact shape and the contact motion, demonstrating potential applications in robotics and remote input interfaces. Since our sensor has a simple structure and its function depends only on sensor dimensions, not on an active sensing material, in comparison with previous tactile sensors, our sensor shows high uniformity and reliability for an array-type integration.

ZnO coated CoFe2O4 nanoparticles for multimodal bio-imaging

RSC Advances ◽  
2016 ◽  
Vol 6 (23) ◽  
pp. 18843-18851 ◽  
Author(s):  
N. Venkatesha ◽  
Yasrib Qurishi ◽  
Hanudatta S. Atreya ◽  
Chandan Srivastava
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Core Shell ◽  
Resonance Imaging ◽  
Cofe2o4 Nanoparticles ◽  
Shell Nanoparticles ◽  
Fluorescence Optical Imaging ◽  
Bio Imaging ◽  
Magnetic Resonance Imaging Mri ◽  
Core Shell Nanoparticles

The potential of CoFe2O4–ZnO core–shell nanoparticles for fluorescence optical imaging and as a contrast agent for magnetic resonance imaging (MRI) is demonstrated.

scholarly journals Review and Prospect: Artificial Intelligence in Advanced Medical Imaging

2021 ◽  
Vol 1 ◽  
Author(s):  
Shanshan Wang ◽  
Guohua Cao ◽  
Yan Wang ◽  
Shu Liao ◽  
Qian Wang ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Deep Learning ◽  
Image Reconstruction ◽  
Medical Imaging ◽  
Imaging Data ◽  
Resonance Imaging ◽  
Volumetric Imaging ◽  
Positron Emission ◽  
Potential Applications ◽  
Magnetic Resonance Imaging Mri

Artificial intelligence (AI) as an emerging technology is gaining momentum in medical imaging. Recently, deep learning-based AI techniques have been actively investigated in medical imaging, and its potential applications range from data acquisition and image reconstruction to image analysis and understanding. In this review, we focus on the use of deep learning in image reconstruction for advanced medical imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET). Particularly, recent deep learning-based methods for image reconstruction will be emphasized, in accordance with their methodology designs and performances in handling volumetric imaging data. It is expected that this review can help relevant researchers understand how to adapt AI for medical imaging and which advantages can be achieved with the assistance of AI.

scholarly journals Stk: An Extendable Python Framework for Automated Molecular and Supramolecular Structure Assembly and Discovery

2021 ◽  
Author(s):  
Lukas Turcani ◽  
Andrew Tarzia ◽  
Filip Szczypiński ◽  
Kim Jelfs
Keyword(s):  
Chemical Space ◽  
General Structure ◽  
Molecular Structures ◽  
Structure Generation ◽  
Supramolecular Materials ◽  
Existing Structures ◽  
Potential Applications ◽  
Speed Up ◽  
User Friendly ◽  
Structure Assembly

<div>Computational software workflows are emerging as all-in-one solutions to speed up the discovery of new materials.</div><div>Many computational approaches require the generation of realistic structural models for property prediction and candidate screening. However, molecular and supramolecular materials represent classes of materials with many potential applications for which there is no go-to database of existing structures or general protocol for generating structures. Here, we report a new version of the supramolecular toolkit, <i>stk</i>, an open-source, extendable and modular Python framework for general structure generation of (supra)molecular structures. Our construction approach follows a bottom-up process and minimises the input required from the user, making <i>stk</i> user-friendly and applicable to many material classes. This version of <i>stk</i> includes metal-containing structures and rotaxanes as well as general implementation and interface improvements. Additionally, this version includes built-in tools for exploring chemical space with an evolutionary algorithm and tools for database generation and visualisation. The latest version of <i>stk</i> is freely available at github.com/lukasturcani/stk</div>

scholarly journals Emerging Applications of Porphyrins and Metalloporphyrins in Biomedicine and Diagnostic Magnetic Resonance Imaging

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 95 ◽  
Author(s):  
Muhammad Imran ◽  
Muhammad Ramzan ◽  
Ahmad Qureshi ◽  
Muhammad Khan ◽  
Muhammad Tariq
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Photophysical Properties ◽  
Biomedical Science ◽  
Resonance Imaging ◽  
Structural Modifications ◽  
Bio Imaging ◽  
Magnetic Resonance Imaging Mri

In recent years, scientific advancements have constantly increased at a significant rate in the field of biomedical science. Keeping this in view, the application of porphyrins and metalloporphyrins in the field of biomedical science is gaining substantial importance. Porphyrins are the most widely studied tetrapyrrole-based compounds because of their important roles in vital biological processes. The cavity of porphyrins containing four pyrrolic nitrogens is well suited for the binding majority of metal ions to form metalloporphyrins. Porphyrins and metalloporphyrins possess peculiar photochemical, photophysical, and photoredox properties which are tunable through structural modifications. Their beneficial photophysical properties, such as the long wavelength of emission and absorption, high singlet oxygen quantum yield, and low in vivo toxicity, have drawn scientists’ interest to discover new dimensions in the biomedical field. Applications of porphyrins and metalloporphyrins have been pursued in the perspective of contrast agents for magnetic resonance imaging (MRI), photodynamic therapy (PDT) of cancer, bio-imaging, and other biomedical applications. This review discusses photophysics and the photochemistry of porphyrins and their metal complexes. Secondly, it explains the current developments and mode of action for contrast agents for MRI. Moreover, the application of porphyrin and metalloporphyrin-based molecules as a photosensitizer in PDT of cancer, the mechanism of the generation of reactive oxygen species (ROS), factors that determine the efficiency of PDT, and the developments to improve this technology are delineated. The last part explores the most recent research and developments on metalloporphyrin-based materials in bio-imaging, drug delivery, and the determination of ferrochelatase in bone marrow indicating their prospective clinical applications.

scholarly journals Unveiling the detection dynamics of semiconductor nanowire photodetectors by terahertz near-field nanoscopy

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Eva A. A. Pogna ◽  
Mahdi Asgari ◽  
Valentina Zannier ◽  
Lucia Sorba ◽  
Leonardo Viti ◽  
...  
Keyword(s):  
Field Effect Transistors ◽  
Near Field ◽  
Low Noise ◽  
Optical Measurements ◽  
Photon Density ◽  
Electric Response ◽  
Clear Understanding ◽  
Strong Nonlinearity ◽  
Semiconductor Nanowire ◽  
Photo Response

AbstractSemiconductor nanowire field-effect transistors represent a promising platform for the development of room-temperature (RT) terahertz (THz) frequency light detectors due to the strong nonlinearity of their transfer characteristics and their remarkable combination of low noise-equivalent powers (<1 nW Hz−1/2) and high responsivities (>100 V/W). Nano-engineering an NW photodetector combining high sensitivity with high speed (sub-ns) in the THz regime at RT is highly desirable for many frontier applications in quantum optics and nanophotonics, but this requires a clear understanding of the origin of the photo-response. Conventional electrical and optical measurements, however, cannot unambiguously determine the dominant detection mechanism due to inherent device asymmetry that allows different processes to be simultaneously activated. Here, we innovatively capture snapshots of the photo-response of individual InAs nanowires via high spatial resolution (35 nm) THz photocurrent nanoscopy. By coupling a THz quantum cascade laser to scattering-type scanning near-field optical microscopy (s-SNOM) and monitoring both electrical and optical readouts, we simultaneously measure transport and scattering properties. The spatially resolved electric response provides unambiguous signatures of photo-thermoelectric and bolometric currents whose interplay is discussed as a function of photon density and material doping, therefore providing a route to engineer photo-responses by design.

scholarly journals On the Emission Properties of Carbon Dots: Reviewing Data and Discussing Models

2019 ◽  
Vol 5 (4) ◽  
pp. 60 ◽  
Author(s):  
Carbonaro ◽  
Corpino ◽  
Salis ◽  
Mocci ◽  
Thakkar ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Green Chemistry ◽  
Optical Imaging ◽  
Carbon Dots ◽  
High Efficiency ◽  
Cell Labelling ◽  
Emission Properties ◽  
Potential Applications ◽  
Bio Imaging

The emission properties of carbon dots (CDs) have already found many potential applications, from bio-imaging and cell labelling, to optical imaging and drug delivery, and are largely investigated in technological fields, such as lighting and photonics. Besides their high efficiency emission, CDs are also virtually nontoxic and can be prepared through many green chemistry routes. Despite these important features, the very origin of their luminescence is still debated. In this paper, we present an overview of sounding data and the main models proposed to explain the emission properties of CDs and their tunability.

Bioenergetic Habitat Suitability Curves for Instream Flow Modeling: Introducing User‐Friendly Software and its Potential Applications

Fisheries ◽  
2020 ◽  
Vol 45 (11) ◽  
pp. 605-613
Author(s):  
Sean M. Naman ◽  
Jordan S. Rosenfeld ◽  
Jason R. Neuswanger ◽  
Eva C. Enders ◽  
John W. Hayes ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Flow Modeling ◽  
Instream Flow ◽  
Potential Applications ◽  
User Friendly

ONE-STEP SYNTHESIS OF BIOCOMPATIBLE CHITOSAN/NaGdF4:Eu3+ NANOCOMPOSITE WITH FLUORESCENT AND MAGNETIC PROPERTIES FOR BIOIMAGING

NANO ◽  
2014 ◽  
Vol 09 (01) ◽  
pp. 1450007 ◽  
Author(s):  
HUI LI ◽  
CHUANXI WANG ◽  
YINGNAN JIANG ◽  
ZHANCHEN CUI ◽  
QUAN LIN
Keyword(s):  
Hexagonal Phase ◽  
Mri Contrast Agent ◽  
Uniform Size ◽  
Mri Contrast ◽  
Potential Applications ◽  
One Step ◽  
Ft Ir ◽  
Good Biocompatibility ◽  
Amine Groups ◽  
Magnetic Resonance Imaging Mri

Lanthanide-doped luminescent nanoscale materials have great potential applications in biological researches. Herein, we reported a novel and mild method for one-step synthesis of chitosan/ NaGdF 4: Eu 3+ nanocomposites. The luminescent Eu 3+ ions and magnetic resonance imaging (MRI) contrast agent Gd 3+ ions were incorporated to these biocompatible nanocomposites. The resultant nanocomposites exhibited strong fluorescence and attractive magnetic features. The nanocomposites also have pure hexagonal phase with uniform size of about 65 nm. FT-IR spectra revealed that these nanocomposites were successfully coated by hydrophilic chitosan, whose amine groups conferred the nanocomposites excellent dispensability in aqueous solution. Besides, the MTT assay and laser confocal microscopy images have confirmed the good biocompatibility of the nanocomposites. These results indicated that the as-prepared nanocomposites could be used as an excellent targeted imaging agent in biological fields.

A study of coFeB magnetic yoke based on planar electromagnet

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744073
Author(s):  
L. Qin ◽  
Q. Li ◽  
Yong J. Yuan
Keyword(s):  
Thin Film ◽  
Drug Delivery ◽  
Chemical Analysis ◽  
Electromagnetic Force ◽  
Permanent Magnets ◽  
Perpendicular Magnetic Anisotropy ◽  
Micro Electro Mechanical System ◽  
Potential Applications ◽  
Biological Medicine ◽  
Copper Coil

This paper studies the fabrication of a novel planar electromagnet consisting of a planar copper coil and a magnetic yoke. CoFeB was used as the magnetic yoke material instead of the traditional permanent magnets. The planar electromagnet was fabricated and optimized to maximize the electromagnetic force, especially with varying CoFeB thickness. The micro-planar electromagnet was fabricated successfully by the traditional micro-electro-mechanical-system (MEMS) techniques and XRD, VSM were used to characterize the performance of the electromagnet. The planar electromagnet exhibits superior perpendicular magnetic anisotropy (PMA) and 0.006 emu of [Formula: see text] was achieved following 2 min deposition of CoFeB thin film. By integrating with other micro apparatuses, it is anticipated that the planar electromagnet will have potential applications in areas such as biosensors, biological medicine, drug delivery, chemical analysis and environmental monitoring.

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