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ABSTRACT Background0.55T systems offer unique advantages and may support expanded access to cardiac MRI. PurposeTo assess the feasibility of 0.55T cardiac MR Fingerprinting (MRF), leveraging a deep image prior reconstruction to mitigate noise. Study TypePhantom and prospective in vivo assessment. PopulationISMRM/NIST MRI system phantom and 18 healthy subjects (11 female; ages 28 ± 8 years). Field Strength and SequencesMRF, modified Look‐Locker inversion recovery (MOLLI), and T2‐prepared balanced steady state free precession (T2‐bSSFP) at 0.55T. AssessmentMRF T1and T2maps were reconstructed using (1) a low‐rank technique with sparse and locally low‐rank regularization (SLLR‐MRF) and (2) a deep image prior (DIP‐MRF). Accuracy and precision of MRF and conventional sequences were evaluated in a phantom. In vivo performance of MRF was evaluated in the 18 healthy subjects, with 7 subjects also undergoing conventional mapping. Myocardial T1and T2values were compared among methods and image quality scored by three readers (2, 3, and 4 years of experience) on a 5‐point scale. Statistical TestsLinear regression, Bland–Altman, intraclass correlation coefficient, and one‐way ANOVA withp < 0.05 considered significant. ResultsMean measurements in the left ventricular septum were 671 ± 31 ms (MOLLI), 761 ± 147 ms (SLLR‐MRF), and 686 ± 39 ms (DIP‐MRF) for T1, and 63.5 ± 5.7 ms (T2‐bSSFP), 47.5 ± 12.7 ms (SLLR‐MRF), and 45.2 ± 4.5 ms (DIP‐MRF) for T2. Compared to conventional mapping, DIP‐MRF exhibited significantly lower T2but no differences in T1(p > 0.99). Standard deviations within the myocardium were significantly lower with DIP‐MRF compared to SLLR‐MRF (39 vs. 147 ms for T1and 4.5 vs. 12.7 ms for T2). Overall image quality ratings were significantly lower for SLLR‐MRF (T1: 2.3, T2: 2.9), which were significantly lower compared to conventional mapping methods (T1: 3.4, T2: 3.9), and DIP‐MRF (T1: 3.8, T2: 4.1) received higher scores. Data ConclusionThis study demonstrated the feasibility of cardiac MRF on a commercial 0.55T system, enabled by a deep image prior reconstruction for denoising. Evidence Level2. Stage of Technical Efficacy1.
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Gd‐Ni‐Sb‐SnO2 electrocatalysts for active and selective ozone production
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Abstract The catalytic hydrothermal liquefaction of biomass under a hydrogen atmosphere is a promising technology to produce stable biocrude oil as a sustainable alternative to petroleum crude. A series of iron‐based non‐noble mix metal‐oxide‐on‐silica catalysts were evaluated to mimic the natural transformation that may have led to the conversion of terrestrial biomass to fossilized fuels. Switchgrass powder was liquefied to a stable bio‐oil with a 71.2% yield by using FeOx/SiO2catalyst in ethanol under a 5.5 MPa hydrogen atmosphere at 210 °C. The use of Fe‐MOx/SiO2(M = V, Mn, Co, Ni, Cu and Mo) type bimetallic oxide catalysts instead of FeOx/SiO2can produce improvements in liquefaction yields by using Mn, Co, Ni, and Cu as the second metal. The highest liquefaction yield of 78.8% was observed with the Fe‐CuOx/SiO2catalyst. Liquefaction oils were formed that were composed of complex mixtures of C6‐C12 alcohols, esters, aldehydes, and phenols. The lignin products:holocellulose products ratio changed in the range 0.35 to 0.15 and the composition of oils changed significantly with the use of mixed metal oxides in place of single metal FeOx/SiO2The most effective catalyst, Fe‐CuOx/SiO2could be reused in five cycles with a small loss in liquefaction yield from 78.8% to 70.0% after four reuse cycles and after regeneration of the catalyst at 500 °C for 3 h in air.more » « less
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Summary Grasses are exceptionally productive, yet their hydraulic adaptation is paradoxical. Among C3grasses, a high photosynthetic rate (Aarea) may depend on higher vein density (Dv) and hydraulic conductance (Kleaf). However, the higherDvof C4grasses suggests a hydraulic surplus, given their reduced need for highKleafresulting from lower stomatal conductance (gs).Combining hydraulic and photosynthetic physiological data for diverse common garden C3and C4species with data for 332 species from the published literature, and mechanistic modeling, we validated a framework for linkages of photosynthesis with hydraulic transport, anatomy, and adaptation to aridity.C3and C4grasses had similarKleafin our common garden, but C4grasses had higherKleafthan C3species in our meta‐analysis. Variation inKleafdepended on outside‐xylem pathways. C4grasses have highKleaf : gs, which modeling shows is essential to achieve their photosynthetic advantage.Across C3grasses, higherAareawas associated with higherKleaf, and adaptation to aridity, whereas for C4species, adaptation to aridity was associated with higherKleaf : gs. These associations are consistent with adaptation for stress avoidance.Hydraulic traits are a critical element of evolutionary and ecological success in C3and C4grasses and are crucial avenues for crop design and ecological forecasting.more » « less
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Abstract This study examined the effects of 24R,25‐dihydroxyvitamin D3(24R,25(OH)2D3) in estrogen‐responsive laryngeal cancer tumorigenesis in vivo, the mechanisms involved, and whether the ability of the tumor cells to produce 24R,25(OH)2D3locally is estrogen‐dependent. Estrogen receptor alpha‐66 positive (ER+) UM‐SCC‐12 cells and ER− UM‐SCC‐11A cells responded differently to 24R,25(OH)2D3in vivo; 24R,25(OH)2D3enhanced tumorigenesis in ER+ tumors but inhibited tumorigenesis in ER− tumors. Treatment with 17β‐estradiol (E2) for 24 h reduced levels of CYP24A1 protein but increased 24R,25(OH)2D3production in ER+ cells; treatment with E2for 9 min reduced CYP24A1 at 24 h and reduced 24R,25(OH)2D3production in ER− cells. These findings suggest the involvement of E2receptor(s) in addition to ERα66. To investigate if 24R,25(OH)2D3can act locally, ER+ and ER− cells were treated with 24R,25(OH)2D3after inhibiting putative 24R,25(OH)2D3receptors, and the cells were assessed for effects on DNA synthesis (proliferation) and p53 production (apoptosis). Specific inhibitors were used to assess downstream secondary messenger signaling pathways and requirements for palmitoylation and caveolae in both cell lines. The results show that 24R,25(OH)2D3binds to a complex of receptors, including TLCD3B2, VDR, and protein disulfide‐isomerase A3 (PDIA3) in ER+ UM‐SCC‐12 cells. The mechanism requires palmitoylation, and PLD, PI3K, and LPAR are involved. The anti‐tumorigenic effects of 24R,25(OH)2D3in ER− UM‐SCC‐11A cells involve a membrane‐receptor complex consisting of VDR, PDIA3, and ROR2 within caveolae to activate a yet‐to‐be‐elucidated downstream signaling cascade. This work demonstrates a driving mechanism for the therapeutic agent 24R,25(OH)2D3that may be used for laryngeal cancer patients.more » « less
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- https://doi.org/10.1002/aic.17486
