Infrared (IR) and Raman spectroscopic features of silicate glasses are often interpreted based on the analogy with those of smaller molecules, molecular clusters, or crystalline counterparts; this ...study tests the accuracy and validity of these widely cited peak assignment schemes by comparing vibrational spectral features with bond parameters of the glass network created by molecular dynamics (MD) simulations. A series of sodium silicate glasses with compositions of Na2OxAl2O32SiO298−x with x = 7, 12, 17, and 22 were synthesized and analyzed with IR and Raman. A silica glass substrate and a crystalline quartz were also analyzed for comparison. Glass structures with the same compositions were generated with MD simulations using three types of potentials: fixed partial charge pairwise (Teter), partial diffuse charge potential (MGFF), and bond order‐based charge transfer potential (ReaxFF). The comparison of simulated and experimental IR spectra showed that, among these three potentials tested, ReaxFF reproduces the concentration dependence of spectral features closest to the experimentally observed trend. Thus, the bond length and angle distributions as well as Si–Qn species and ring size distributions of silica and sodium silicate glasses were obtained from ReaxFF‐MD simulations and further compared with the peak assignment or deconvolution schemes—which have been widely used since 1970s and 1980s—(a) correlation between the IR peak position in the Si–O stretch region (1050‐1120 cm−1) and the Si–O–Si bond angle; (b) deconvolution of the Raman bands in the Si–O stretch region with the Qn speciation; and (c) assignment of the Raman bands in the 420‐600 cm−1 region to the bending modes of (SiO)n rings with different sizes (typically, n = 3‐6). The comparisons showed that none of these widely used methods is congruent with the bond parameters or structures of silicate glass networks produced via ReaxFF‐MD simulations. This finding invokes that the adequacy of these spectral interpretation methods must be questioned. Alternative interpretations are proposed, which are to be tested independently in future studies.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Management of chronic thromboembolic pulmonary hypertension (CTEPH) should be determined by a multidisciplinary team, ideally at a specialized CTEPH referral center. Radiologists contribute to this ...multidisciplinary process by helping to confirm the diagnosis of CTEPH and delineating the extent of disease, both of which help determine a treatment decision. Preoperative assessment of CTEPH usually employs multiple imaging modalities, including ventilation-perfusion (V/Q) scanning, echocardiography, CT pulmonary angiography (CTPA), and right heart catheterization with pulmonary angiography. Accurate diagnosis or exclusion of CTEPH at imaging is imperative, as this remains the only form of pulmonary hypertension that is curative with surgery. Unfortunately, CTEPH is often misdiagnosed at CTPA, which can be due to technical factors, patient-related factors, radiologist-related factors, as well as a host of disease mimics including acute pulmonary embolism, in situ thrombus, vasculitis, pulmonary artery sarcoma, and fibrosing mediastinitis. Although V/Q scanning is thought to be substantially more sensitive for CTEPH compared with CTPA, this is likely due to lack of recognition of CTEPH findings rather than a modality limitation. Preoperative evaluation for pulmonary thromboendarterectomy (PTE) includes assessment of technical operability and surgical risk stratification. While the definitive therapy for CTEPH is PTE, other minimally invasive or noninvasive therapies also lead to clinical improvements including greater survival. Complications of PTE that can be identified at postoperative imaging include infection, reperfusion edema or injury, pulmonary hemorrhage, pericardial effusion or hemopericardium, and rethrombosis.
RSNA, 2022
The Dominion Range 2010 howardite pairing group contains an evolved lithic clast of dacite composition. The dacite contains an assemblage of plagioclase, quartz, and augite, with minor pigeonite, ...troilite, ilmenite, FeNi metal, K‐feldspar, and phosphates. Primary augite occurs as >1 mm oikocrysts enclosing plagioclase. Quartz is abundant, comprising approximately 30% of the clast. Textural and geochemical characteristics support the hypothesis that the dacite is a primary igneous lithology, and represents a partial melt of the eucritic crust. Numerical modeling (MELTS) suggests 10–20% partial melting of a Juvinas source could have produced the dacite lithology; quantitative trace element modeling further supports crustal partial melting as the magma source for the dacite. The dacite likely formed as evolved‐melt pockets, and thus represents a volumetrically minor lithology in the Vestan crust, although its formation provides direct support for a genetic relationship between Stannern and residual trend eucrites, and is the first identification of residual eucrite complementary melts. We propose the dacite clast is the first characterized sample of tertiary crust on Vesta.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We performed a near-infrared (NIR; ∼1.0 –2.4 $\mu$m) stellar population study in a sample of early-type galaxies. The synthesis was performed using five different evolutionary population synthesis ...libraries of models. Our main results can be summarized as follows: low-spectral-resolution libraries are not able to produce reliable results when applied to the NIR alone, with each library finding a different dominant population. The two newest higher resolution models, on the other hand, perform considerably better, finding consistent results to each other and to literature values. We also found that optical results are consistent with each other even for lower resolution models. We also compared optical and NIR results and found out that lower resolution models tend to disagree in the optical and in the NIR, with higher fraction of young populations in the NIR and dust extinction ∼1 mag higher than optical values. For higher resolution models, optical and NIR results tend to agree much better, suggesting that a higher spectral resolution is fundamental to improve the quality of the results.
We describe petrographic, electron microprobe, and laser ablation ICP‐MS analyses of Mg‐rich harzburgite clasts in the Dominion Range 2010 howardites, and conclude that they are xenolithic samples of ...the vestan mantle. Key chemical and petrologic characteristics of these rocks provide tests for differentiation models. Our results indicate the mantle of Vesta formed through variable degrees of partial melting, which left behind a harzburgite and possibly dunite residuum. The Mg‐rich clasts are composed of orthopyroxene and olivine, with minor clinopyroxene, FeNi metal, and distinctive pyroxene–chromite symplectites. We use mineral chemistry to demonstrate the absence of a genetic link between diogenites and the Mg‐rich harzburgites. We propose a secondary origin for the formation of symplectites: interaction of silicate and metallic melts during primordial differentiation and core formation. The occurrence of FeNi metal containing ~1.5 wt% Cr within the assemblage indicates a very reducing environment during mantle differentiation (≪IW). Our study suggests that Vesta did not experience complete melting early in its history, and instead supports the formation of a shallow magma ocean.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Exercise is known to induce beneficial effects in synovial joints. However, the mechanisms underlying these are unclear. Synovial joints experience repeated mechanical loading during exercise. These ...mechanical stimuli are transduced into biological responses through cellular mechanotransduction. Mechanotransduction in synovial joints is typically studied in tissues. However, synovial fluid directly contacts all components of the joint, and thus may produce a whole-joint picture of the mechanotransduction response to loading. The objective of this study was to determine if metabolic phenotypes are present in the synovial fluid after acute exercise as a first step to understanding the beneficial effects of exercise on the joint.
Mice underwent a single night of voluntary wheel running or standard housing and synovial fluid was harvested for global metabolomic profiling by LC-MS. Hierarchical unsupervised clustering, partial least squares discriminant, and pathway analysis provided insight into exercise-induced mechanotransduction.
Acute exercise produced a distinct metabolic phenotype in synovial fluid. Mechanosensitive metabolites included coenzyme A derivatives, prostaglandin derivatives, phospholipid species, tryptophan, methionine, vitamin D3, fatty acids, and thiocholesterol. Enrichment analysis identified several pathways previously linked to exercise including amino acid metabolism, inflammatory pathways, citrulline-nitric oxide cycle, catecholamine biosynthesis, ubiquinol biosynthesis, and phospholipid metabolism.
To our knowledge, this is the first study to investigate metabolomic profiles of synovial fluid during in vivo mechanotransduction. These profiles indicate that exercise induced stress-response processes including both pro- and anti-inflammatory pathways. Further research will expand these results and define the relationship between the synovial fluid and the serum.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Quantifying the amounts of various igneous lithologies in Vesta’s crust allows the estimation of petrologic ratios that describe the asteroid’s global differentiation and subsequent magmatic history. ...The eucrite:diogenite (Euc:Diog) ratio measures the relative proportions of mafic and ultramafic components. The intrusive:extrusive (I:E) ratio assesses the effectiveness of magma ascent and eruption. We estimate these ratios by counting numbers and masses of eucrites, cumulate eucrites, and diogenites in the world’s meteorite collections, and by calculating their proportions as components of crustal polymict breccias (howardites) using chemical mixing diagrams and petrologic mapping of multiple thin sections. The latter two methods yield a Euc:Diog ratio of ∼2:1, although meteorite numbers and masses give slightly higher ratios. Surface lithologic maps compiled from spectra of Dawn spacecraft instruments (VIR and GRaND) yield Euc:Diog ratios that bracket estimates of Euc:Diog from the meteorites. The I:E ratios from HEDs lie between 0.5–2.1:1, due to uncertainties in identifying cumulate eucrite. Gravity mapping of Vesta by the Dawn spacecraft supports the existence of diogenite plutons in the crust. Quantifying the proportion of high-density diogenitic crust in the gravity map yields I:E ratios of 0.8-1:2:1, values which are bracketed by calculations based on HEDs. The I:E ratio for Vesta is lower than for Earth and Mars, consistent with physical modeling of asteroid-size bodies. Nevertheless, it indicates a significant role for pluton emplacement during the formation of Vesta’s crust. These results are inconsistent with simple differentiation models that produce the crust by crystallization of a global magma ocean, unless residual melts are extracted into crustal magma chambers.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We present a well-resolved, highly inclusive phylogeny for monocots, based on ndhF sequence variation, and use it to test a priori hypotheses that net venation and vertebrate-dispersed fleshy fruits ...should undergo concerted convergence, representing independent but often concurrent adaptations to shaded conditions. Our data demonstrate that net venation arose at least 26 times and was lost eight times over the past 90 million years; fleshy fruits arose at least 21 times and disappeared 11 times. Both traits show a highly significant pattern of concerted convergence (p<10−9), arising 16 times and disappearing four times in tandem. This phenomenon appears driven by even stronger tendencies for both traits to evolve in shade and be lost in open habitats (p<10−13-10−29). These patterns are among the strongest ever demonstrated for evolutionary convergence in individual traits and the predictability of evolution, and the strongest evidence yet uncovered for concerted convergence. The rate of adaptive shifts per taxon has declined exponentially over the past 90 million years, as expected when large-scale radiations fill adaptive zones.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
To explore how systemic factors that modify knee osteoarthritis risk are connected to ‘whole-joint’ structural changes by evaluating the effects of high-fat diet and wheel running exercise on ...synovial fluid (SF) metabolomics.
Male mice were fed a defined control or high-fat (60% kcal fat) diet from 6 to 52 weeks of age, and half the animals were housed with running wheels from 26 to 52 weeks of age (n = 9–13 per group). Joint tissue structure and osteoarthritis pathology were evaluated by histology and micro-computed tomography. Systemic metabolic and inflammatory changes were evaluated by body composition, glucose tolerance testing, and serum biomarkers. SF metabolites were analyzed by high performance-liquid chromatography mass spectrometry. We built correlation-based network models to evaluate the connectivity between systemic and local metabolic biomarkers and osteoarthritis structural pathology within each experimental group.
High-fat diet caused moderate osteoarthritis, including cartilage pathology, synovitis and increased subchondral bone density. In contrast, voluntary exercise had a negligible effect on these joint structure components. 1,412 SF metabolite features were detected, with high-fat sedentary mice being the most distinct. Diet and activity uniquely altered SF metabolites attributed to amino acids, lipids, and steroids. Notably, high-fat diet increased network connections to systemic biomarkers such as interleukin-1β and glucose intolerance. In contrast, exercise increased local joint-level network connections, especially among subchondral bone features and SF metabolites.
Network mapping showed that obesity strengthened SF metabolite links to blood glucose and inflammation, whereas exercise strengthened SF metabolite links to subchondral bone structure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Extended Length Test Article-Cartridge Lead is a test assembly for conducting in-pile research in the Versatile Test Reactor to support the advanced molten lead-cooled reactor under development ...at the Westinghouse Company. This work investigates four pumping options for circulating molten lead at 500°C and develops an integrated thermal-hydraulic model to estimate the demand curves. The four pumping options fit within cartridge riser tubes that are 57.0 and 68.8 mm in diameter. These options are (1) gas lift pumping, (2) the miniature submerged annular linear induction pump, (3) the miniature submerged direct-current electromagnetic pump, and (4) the miniature axial-centrifugal flow mechanical pump. Gas lift pumping is the simplest and is fully passive with no heat dissipation, but it generates the lowest pumping pressure and flow rate. The mechanical pump and direct-current electromagnetic pump generate the highest pumping pressures, flow rates, and average velocities of molten Pb in the test article of three-fuel rodlets in a triangular lattice. The mechanical pump designs provide the highest flow velocities in the test article and the slowest decrease in pumping pressure with increased flow rate at low thermal power dissipation. The optimized electromagnetic pump designs with no moving parts and elevated temperature ALNICO-5 permanent magnets meet or exceed the target flow velocities in the test article but at higher rate of heat dissipation than the mechanical pump designs.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
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