Potassium-39 ((39)K) magnetic resonance imaging (MRI) is a noninvasive technique which could potentially allow for detecting intracellular physiological variations in common human pathologies such as stroke and cancer. However, the low signal-to-noise ratio (SNR) achieved in (39)K-MR images hampered data acquisition with sufficiently high spatial and temporal resolution in animal models so far. Full wave electromagnetic (EM) simulations were performed for a single-loop copper (Cu) radio frequency (RF) surface resonator with a diameter of 30 mm optimized for rat brain imaging at room temperature (RT) and at liquid nitrogen (LN2) with a temperature of 77 K. A novel cryogenic Cu RF surface resonator with home-built LN2 nonmagnetic G10 fiberglass cryostat system for small animal scanner at 9.4 T was designed, built and tested in phantom and in in vivo MR measurements. Aerogel was used for thermal insulation in the developed LN2 cryostat. In this paper, we present the first in vivo (39)K-MR images at 9.4 T for both healthy and stroke-induced rats using the developed cryogenic coil at 77 K. In good agreement with EM-simulations and bench-top measurements, the developed cryogenic coil improved the SNR by factor of 2.7 ± 0.2 in both phantom and in in vivo MR imaging compared with the same coil at RT.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1109/TBME.2013.2294277 | DOI Listing |
Adv Sci (Weinh)
January 2025
James Watt School of Engineering, University of Glasgow, Glasgow, G12 8QQ, UK.
Capacitive dielectric temperature sensors based on polydimethylsiloxane (PDMS) loaded with 10 vol% of inexpensive, commercially-available conductive fillers including copper, graphite, and milled carbon fiber (PDMS-CF) powders are reported. The sensors are tested in the range of 20-110 °C and from 0.5 to 200 MHz, with enhanced sensitivity from 20 to 60 °C, and a relative response of 85.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Diagnostic Radiology, Yong Loo Lin School of Medicine, National University of Singapore, 119074, Singapore.
The emerging combination of chemotherapy and radionuclide therapy has been actively investigated to overcome the limitations of monotherapy and augment therapeutic efficacy. However, it remains a challenge to design a single delivery vehicle that can incorporate chemotherapeutics and radionuclides into a compact structure. Here, a chelator DOTA- or NOTA-modified Evans blue conjugated camptothecin molecule (EB-CPT) nanoprodrug was synthesized, which could self-assemble into nanoparticles due to its inherent amphiphilicity.
View Article and Find Full Text PDFHeliyon
November 2024
Faculty of Physics, Shahrood University of Technology, 3619995161, Shahrood, Iran.
This study evaluates the deposition of diamond-like carbon (DLC) films with copper impurities on a glass substrate using simultaneous direct current (DC) and radio frequency (RF) magnetron sputtering. The structural, optical, electrical, and mechanical properties, as well as the surface topography of the films, were investigated under various DC power levels using Raman spectroscopy, ellipsometry, UV-VIS, I-V measurements, nanoindentation, AFM, and FESEM. Results indicate that increasing the DC power to the graphite target from 60 to 120 , while maintaining a constant 10 of RF power to the copper target, enhances the optical absorption coefficient of the films and increases the optical bandgap from 0.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
Division of Physics, Engineering, Mathematics and Computer Sciences and Optical Science Center for Applied Research, Delaware State University, Dover, DE 19901, USA.
This study offers a comprehensive summary of the current states as well as potential future directions of transparent conducting oxides (TCOs), particularly tin-doped indium oxide (ITO), the most readily accessible TCO on the market. Solar cells, flat panel displays (FPDs), liquid crystal displays (LCDs), antireflection (AR) coatings for airbus windows, photovoltaic and optoelectronic devices, transparent p-n junction diodes, etc. are a few of the best uses for this material.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States.
Atomic-layer-deposited (ALD) "leaky" TiO has gained interest as a charge-selective protection layer for semiconductor solar fuel electrodes. Here, the use of sputter-deposited TiO layers as hole-selective contacts for WO/CuWO type-2 heterojunction water oxidation photoanodes is demonstrated for the first time. TiO protection layers with varying thicknesses (2 to 128 nm) were deposited by using the radio frequency (RF) magnetron sputtering technique.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!