The spin relaxation mechanism in single-crystalline and polycrystalline platinum (Pt) thin films is revealed by a quantum interference effect. Examining the relationship between the spin relaxation rate and momentum scattering rate by changing Pt thickness, we find that the spin relaxation rate of Pt strongly depends on both crystal structure and thickness even though the quality of material (Pt) is unchanged. In particular, the D'yakonov-Perel' mechanism is considered as a dominant mechanism under cases where scattering events are suppressed or the interface effect is not negligible.
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http://dx.doi.org/10.1103/PhysRevLett.116.256802 | DOI Listing |
Quant Imaging Med Surg
January 2025
Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Background: Pediatric growth hormone deficiency (GHD) is a disease resulting from the impaired growth hormone-insulin-like growth factor-1 (GH-IGF-1) axis, but the effects of GHD on children's behavior and brain microstructural structure alterations have not yet been fully clarified. We aimed to investigate the quantitative profiles of gray matter and white matter in pediatric GHD using synthetic magnetic resonance imaging (MRI).
Methods: The data of 50 children with GHD and 50 typically developing (TD) children were prospectively collected.
Hum Brain Mapp
February 2025
Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul National University, Seoul, Republic of Korea.
Magnetic susceptibility source separation (χ-separation), an advanced quantitative susceptibility mapping (QSM) method, enables the separate estimation of paramagnetic and diamagnetic susceptibility source distributions in the brain. Similar to QSM, it requires solving the ill-conditioned problem of dipole inversion, suffering from so-called streaking artifacts. Additionally, the method utilizes reversible transverse relaxation ( ) to complement frequency shift information for estimating susceptibility source concentrations, requiring time-consuming data acquisition for (e.
View Article and Find Full Text PDFMagn Reson Med
January 2025
National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA.
Purpose: This study aims to improve the detection of glutamate (Glu) concentration and T using an enhanced transverse relaxation encoding with narrowband decoupling (TREND) technique.
Methods: A new editing pulse was designed to simultaneously invert both Glu H3 spins (2.12 ppm and 2.
Magn Reson Med
January 2025
Oxygen Measurement Core, O2M Technologies, LLC, Chicago, Illinois, USA.
Purpose: Solid crystalline spin probes, such as lithium phthalocyanine (LiPc) and lithium octa-n-butoxynaphthalocyanine (LiNc-BuO), allow repeated oxygen measurement using electron paramagnetic resonance (EPR). Due to their short relaxation times, their use for pulse EPR oxygen imaging is limited. In this study, we developed and tested a new class of solid composite spin probes that modified the relaxation rates R and R of LiPc or LiNc-BuO probes, which allowed pO measurements in the full dynamic (0-760 torr) range.
View Article and Find Full Text PDFMacromolecules
January 2025
Department of Materials Science & Engineering, Texas A&M University, College Station, Texas 77840, United States.
This work explored solution properties of linear and star poly(methacrylic acids) with four, six, and eight arms (PMAA, 4PMAA, PMAA, and 8PMAA, respectively) of matched molecular weights in a wide range of pH, salt, and polymer concentrations. Experimental measurements of self-diffusion were performed by fluorescence correlation spectroscopy (FCS), and the results were interpreted using the scaling theory of polyelectrolyte solutions. While all PMAAs were pH sensitive and showed an increase in hydrodynamic radius ( ) with pH in the dilute regime, the of star polymers (measured at basic pH values) was significantly smaller for the star polyacids due to their more compact structure.
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