Purpose: A shortage of suitable donor livers is driving increased use of higher risk livers for transplantation. However, current biomarkers are not sensitive and specific enough to predict posttransplant liver function. This is limiting the expansion of the donor pool. Therefore, better noninvasive tests are required to determine which livers will function following implantation and hence can be safely transplanted. This study assesses the temperature sensitivity of proton density fat fraction and relaxometry parameters and examines their potential for assessment of liver function ex vivo.
Methods: Six ex vivo human livers were scanned during static cold storage following normothermic machine perfusion. Proton density fat fraction, T , T , and were measured repeatedly during cooling on ice. Temperature corrections were derived from these measurements for the parameters that showed significant variation with temperature.
Results: Strong linear temperature sensitivities were observed for proton density fat fraction (R = 0.61, P < .001) and T (R = 0.78, P < .001). Temperature correction according to a linear model reduced the coefficient of repeatability in these measurements by 41% and 36%, respectively. No temperature dependence was observed in T or measurements. Comparing livers deemed functional and nonfunctional during normothermic machine perfusion by hemodynamic and biochemical criteria, T differed significantly: 516 ± 50 ms for functional versus 679 ± 60 ms for nonfunctional, P = .02.
Conclusion: Temperature correction is essential for robust measurement of proton density fat fraction and T in cold-stored human livers. These parameters may provide a noninvasive measure of viability for transplantation.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7613197 | PMC |
http://dx.doi.org/10.1002/mrm.28930 | DOI Listing |
Nano Lett
January 2025
Institute of Future Technology, Southwest Jiaotong University, Chengdu 610031, China.
Building insights into the structure-performance relationship of catalysts has been emphasized recently. However, it remains a challenge due to catalysts' various and complex structures, especially the easily overlooked influence of the support material. Here, we reveal the crucial influences of boron introduction on synthesizing 3D carbon nanotube monoliths with embedded multistate Co metals, i.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Dipartimento di Scienze Fisiche e Chimiche, Universita degli Studi dellAquila, Coppito, 67100 L'Aquila, Italy.
We present a comprehensive theoretical study, using state-of-the-art density functional theory simulations, of the structural and electrochemical properties of amorphous pristine and iron-doped nickel-(oxy)hydroxide catalyst films for water oxidation in alkaline solutions, referred to as NiCat and Fe:NiCat. Our simulations accurately capture the structural changes in locally ordered units, as reported by X-ray absorption spectroscopy, when the catalyst films are activated by exposure to a positive potential. We emphasize the critical role of proton-coupled electron transfer in the reversible oxidation of Ni(II) to Ni(III/IV) during this activation.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, Barcelona 08028, Spain.
The oxygen reduction reaction (ORR) stands as a pivotal process in electrochemistry, finding applications in various energy conversion technologies such as fuel cells, metal-air batteries, and chlor-alkali electrolyzers. Hereby, a comprehensive density functional theory (DFT) investigation is presented into the proposed conventional and unconventional ORR mechanisms using single-atom catalysts (SACs) supported on nitrogen-doped graphene (NG) as model systems. Several reaction intermediates have been identified that appear to be more stable than the ones postulated in the conventional mechanism, which follows the *OOH, *O, and *OH intermediates.
View Article and Find Full Text PDFInorg Chem
January 2025
Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
Sodium borohydride dihydrate (NaBH·2HO) forms through dihydrogen bonding between the hydridic hydrogen of the BH ion and the protonic hydrogen of the water molecule. High-pressure structural changes in NaBH·2HO, observed up to 11 GPa through X-ray diffraction and Raman scattering spectroscopy, were analyzed to assess the influence of dihydrogen bonds on its crystal structure. At approximately 4.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
Although microenvironments surrounding single-atom catalysts (SACs) have been widely demonstrated to have a remarkable effect on their catalytic performances, it remains unclear whether the local structure beyond the secondary coordination shells works as well or not. Herein, we employed a series of metal-organic frameworks (MOFs) with well-defined and tunable second-beyond coordination spheres as model SAC electrocatalysts to discuss the influence of long-distance structure on the ammonia synthesis from nitrate, which were synthesized and denoted as Cu-NDI-X (X = NMe, H, F). It is first experimentally confirmed that the remote substitution of function groups beyond the secondary coordination sphere can remarkably affect the activity of ammonia synthesis.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!