Purpose: In principle, double echo steady state (DESS) offers morphological and quantitative T2 imaging of cartilage within one single scan. However, accurate T2 estimation is hampered by its prominent T1 dependency in the limit of low flip angles, generally used to image cartilage morphology, as for the osteoarthritis initiative. A new postprocessing approach is introduced to overcome this T1-related bias for rapid DESS-based T2 quantification in the low flip angle regime.
Methods: Based on a rough global T1 estimator and a golden section search, T2 is extracted from the ratio of the two echoes acquired with DESS. The new relaxometry method is evaluated from simulations and in vivo 3D measurements of the knee joint at 3T.
Results: A pronounced reduction in the T1-related bias of DESS-T2 estimation and increased zonal variation in T2 between deep and superficial cartilage layers are observed. The improvement becomes particularly evident in the range of low flip angles (α < 45°), commonly used for morphological DESS imaging.
Conclusion: Using a simple global T1 estimate, the reliability of DESS-T2 quantification can be considerably increased. The results emphasize the potential of DESS to fuse accurate quantitative T2 and morphological imaging of the musculoskeletal system within one single scan.
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http://dx.doi.org/10.1002/mrm.24748 | DOI Listing |
J Phys Chem A
January 2025
School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
Searching for single-molecule magnets (SMM) with large effective blocking barriers, long relaxation times, and high magnetic blocking temperatures is vitally important not only for the fundamental research of magnetism at the molecular level but also for the realization of new-generation magnetic memory unit. Actinides (An) atoms possess extremely strong spin-orbit coupling (SOC) due to their 5 orbitals, and their ground multiplets are largely split into several sublevels because of the strong interplay between the SOC of An atoms and the crystal field (CF) formed by ligand atoms. Compared to TM-based SMMs, more dispersed energy level widths of An-based SMMs will give a larger total zero field splitting (ZFS) and thus provide a necessary condition to derive a higher .
View Article and Find Full Text PDFJ Phys Condens Matter
January 2025
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, No.8 South Third Street, Zhongguancun, Beijing, 100190, CHINA.
We systematically investigate the magnetization and thermodynamic responses associated with antiferromagnetic (AFM) transitions in single crystals of the magnetic semiconductor Eu3InAs3. The linear thermal expansion measurements around the AFM transition temperatures, TN1 and TN2, indicate an expansion along the a axis and contraction along the b and c axes. The calculated ∆V/V(T) shows a continuous change at TN, indicating a second-order magnetic phase transition.
View Article and Find Full Text PDFAm J Transplant
December 2024
The Dumont-UCLA Transplantation Center, Department of Surgery, Division of Liver and Pancreas Transplantation, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095; Department of Surgery, Medical University of South Carolina, Charleston, SC 29425. Electronic address:
As important immune regulatory cells, whether innate lymphoid cells (ILCs) are involved in liver transplantation (LT) remains unclear. In a murine orthotopic LT model, we dissected roles of ILCs in liver ischemia-reperfusion injury (IRI). Wild type (WT) grafts suffered significantly higher IRI in Rag2-γc double knockout (DKO) than Rag2 KO recipients, in association with downregulation of group 1 ILCs genes, including IFN-γ.
View Article and Find Full Text PDFElife
December 2024
Computational Biophysics and CADD Group, Computational and Mathematical Biology Center, Translational Health Science and Technology Institute, Faridabad, India.
Agonists enhance receptor activity by providing net-favorable binding energy to active over resting conformations, with efficiency (η) linking binding energy to gating. Previously, we showed that in nicotinic receptors, η-values are grouped into five structural pairs, correlating efficacy and affinity within each class, uniting binding with allosteric activation (Indurthi and Auerbach, 2023). Here, we use molecular dynamics (MD) simulations to investigate the low-to-high affinity transition (L→H) at the Torpedo α-δ nicotinic acetylcholine receptor neurotransmitter site.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Synthetic Organic Chemistry, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, Nijmegen 6525 AJ, The Netherlands.
One of the main challenges in oligosaccharide synthesis is the stereoselective introduction of the glycosidic bond. In order to understand and control glycosylation reactions, thorough mechanistic studies are required. Reaction intermediates found by NMR spectroscopy often cannot explain the glycosylation's stereochemical outcome.
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