Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
201,475
result(s) for
"Ho, A."
Sort by:
The rhetorical exercises of Nikephoros Basilakes : progymnasmata from twelfth-century Byzantium
Progymnasmata are literally \"exercises\" that are \"preliminary\" to declamation, which is the composition and delivery of ostensibly impromptu speeches in the guise of fictional, mythical, or historical characters who serve as prosecution or defense in fictitious trial scenarios. Basilakes's collection includes highly polished examples of fable, narration, maxim, refutation, confirmation, encomium, and ethopoeia. Basilakes's exercises draw on myth, ancient history, the Bible, and other Christian texts, and they use specific words and phrases from ancient Greek epic, tragedy, historiography, and other genres. The progymnasmata also feature mythological and biblical stories that Basilakes treats more than once, the most obvious example being his handling of the myth of Atalanta as both a refutation and a confirmation. In other cases, however, he revisits stories so as to highlight different perspectives, changes in disposition, and moral dilemmas.-- Provided by publisher
Book
A radio counterpart to a neutron star merger
Gravitational waves have been detected from a binary neutron star merger event, GW170817. The detection of electromagnetic radiation from the same source has shown that the merger occurred in the outskirts of the galaxy NGC 4993, at a distance of 40 megaparsecs from Earth. We report the detection of a counterpart radio source that appears 16 days after the event, allowing us to diagnose the energetics and environment of the merger. The observed radio emission can be explained by either a collimated ultrarelativistic jet, viewed off-axis, or a cocoon of mildly relativistic ejecta. Within 100 days of the merger, the radio light curves will enable observers to distinguish between these models, and the angular velocity and geometry of the debris will be directly measurable by very long baseline interferometry.
Journal Article
Illuminating gravitational waves
Merging neutron stars offer an excellent laboratory for simultaneously studying strong-field gravity and matter in extreme environments. We establish the physical association of an electromagnetic counterpart (EM170817) with gravitational waves (GW170817) detected from merging neutron stars. By synthesizing a panchromatic data set, we demonstrate that merging neutron stars are a long-sought production site forging heavy elements by r-process nucleosynthesis. The weak gamma rays seen in EM170817 are dissimilar to classical short gamma-ray bursts with ultrarelativistic jets. Instead, we suggest that breakout of a wide-angle, mildly relativistic cocoon engulfing the jet explains the low-luminosity gamma rays, the high-luminosity ultraviolet-optical-infrared, and the delayed radio and x-ray emission. We posit that all neutron star mergers may lead to a wide-angle cocoon breakout, sometimes accompanied by a successful jet and sometimes by a choked jet.
Journal Article
The Impact of Metabolic Rewiring in Glioblastoma: The Immune Landscape and Therapeutic Strategies
Glioblastoma (GBM) is an aggressive brain tumor characterized by extensive metabolic reprogramming that drives tumor growth and therapeutic resistance. Key metabolic pathways, including glycolysis, lactate production, and lipid metabolism, are upregulated to sustain tumor survival in the hypoxic and nutrient-deprived tumor microenvironment (TME), while glutamine and tryptophan metabolism further contribute to the aggressive phenotype of GBM. These metabolic alterations impair immune cell function, leading to exhaustion and stress in CD8+ and CD4+ T cells while favoring immunosuppressive populations such as regulatory T cells (Tregs) and M2-like macrophages. Recent studies emphasize the role of slow-cycling GBM cells (SCCs), lipid-laden macrophages, and tumor-associated astrocytes (TAAs) in reshaping GBM’s metabolic landscape and reinforcing immune evasion. Genetic mutations, including Isocitrate Dehydrogenase (IDH) mutations, Epidermal Growth Factor Receptor (EGFR) amplification, and Phosphotase and Tensin Homolog (PTEN) loss, further drive metabolic reprogramming and offer potential targets for therapy. Understanding the relationship between GBM metabolism and immune suppression is critical for overcoming therapeutic resistance. This review focuses on the role of metabolic rewiring in GBM, its impact on the immune microenvironment, and the potential of combining metabolic targeting with immunotherapy to improve clinical outcomes for GBM patients.
Journal Article
Biphasic in vitro maturation (CAPA-IVM) specifically improves the developmental capacity of oocytes from small antral follicles
PurposeTo investigate the effectiveness of a biphasic IVM culture strategy at improving IVM outcomes in oocytes from small follicles (< 6 mm) compared with routine Standard IVM in patients with polycystic ovaries.MethodsThis prospective pilot study was performed in 40 women with polycystic ovaries whose oocytes were randomized to two IVM culture methods. Patients received a total stimulation dose of 450 IU rFSH. Cumulus-oocyte complexes (COCs) from follicles < 6 mm and ≥ 6 mm were retrieved and cultured separately in either a prematuration medium with c-type natriuretic peptide followed by IVM (CAPA-IVM), or STD-IVM. Primary outcomes were maturation rate, embryo quality, and the number of vitrified day 3 embryos per patient.ResultsUse of the CAPA-IVM system led to a significant improvement in oocyte maturation (p < 0.05), to a doubling in percentage of good and top-quality day 3 embryos per COC, and to an increased number of vitrified day 3 embryos (p < 0.001), compared to STD IVM. Oocytes from follicles < 6 mm benefited most from CAPA-IVM, showing a significant increase in the amount of good and top-quality embryos compared to STD IVM. CAPA-IVM yielded significantly (p < 0.0001) less GV-arrested oocytes and larger oocyte diameters (p < 0.05) than STD IVM.ConclusionsCAPA-IVM brings significant improvements in maturation and embryological outcomes, most notably to oocytes from small antral follicles (< 6 mm), which can be easily retrieved from patients with a minimal ovarian stimulation. The study demonstrates the robustness and transferability of the CAPA-IVM method across laboratories and populations.
Journal Article
Effects of Ar Ion Irradiation on Mechanical Properties and Microstructure of SA508 Grade 3 Class 1 and Class 2 Reactor Pressure Vessel Steels
This study investigates the effects of Ar ion irradiation on the mechanical properties and microstructure of SA508 Grade 3 Class 1 and Class 2 reactor pressure vessel steels. Three different fluence levels of Ar ion irradiation were applied to simulate accelerated irradiation damage conditions. Charpy impact and tensile tests conducted before and after irradiation showed no significant changes in bulk mechanical properties. Stopping and Range of Ions in Matter (SRIM) and Transport of Ions in Matter (TRIM) simulations revealed that Ar ion irradiation produces a shallow penetration depth of approximately 2.5 µm, highlighting the limitations of conventional macro-mechanical testing for evaluating irradiation effects in such a thin surface layer. To overcome this limitation, nano-indentation tests were performed, revealing a clear increase in indentation hardness after irradiation. Transmission electron microscopy (TEM) analysis using STEM–BF imaging confirmed a higher density of irradiation-induced defects in the irradiated specimens. The findings demonstrate that while macro-mechanical properties remain largely unaffected, micro-scale testing methods such as nano-indentation are essential for assessing irradiation-induced hardening in shallowly damaged layers, providing insight into the behavior of SA508 reactor pressure vessel steels under accelerated irradiation conditions.
Journal Article
E-250 17 Microcatheter delivery of the eric™ retrieval device: a single-center case series
Introduction/PurposeMechanical thrombectomy is the gold standard intervention for large vessel occlusion (LVO) ischemic stroke since the multiple positive trials in 2015. Retrieval devices are commonly used and contribute to efficacy. Microcatheter selection depends on internal diameter (ID) compatibility of the microcatheter and retrieval device. The Embolus Retriever with Interlinked Cages (ERIC™) 4 and 6 are labeled compatible with 0.021-inch minimum ID microcatheters, and ERIC™ 3 is compatible with 0.017-inch microcatheters. We report the feasibility of 0.017 and 0.0165 microcatheters for delivery of all ERIC™ devices. Materials and MethodsAll patients who underwent LVO thrombectomy at our institution since ERIC™ became commercially available in June 2023 were screened and their devices used were analyzed. Only patients for whom an ERIC™ was used, which was delivered using a 0.017- or a 0.0165-inch ID microcatheter were included.ResultsTwenty patients met these criteria. Patient age, LVO location, number of thrombectomy passes, mTICI score, and device list are included in the following table. The images demonstrate a radiographic example of the microcatheter and embolus retriever compatibility. Notably, 13 of the 20 patients achieved TICI 2b or 3 recanalization. All three sizes of ERIC™ were utilized. Multiple 0.017 and 0.0165 ID microcatheters were used.ConclusionThrombectomy success in LVO stroke depends on multiple factors. Smaller microcatheters permit improved navigability and imaging quality when injecting through intermediate catheters. They may contribute to less clot disruption thus less risk for distal embolization from fragmentation. This is the first reported series ERIC™ embolus retriever delivery through microcatheters smaller than listed compatibility. This series may permit operators to select from a wider variety of compatible devices to individualize care for each stroke patient.Abstract E-250 Table 1Abstract E-250 Figure 1Disclosures A. Ho: None. B. Jagadeesan: 2; C; Microvention, Stryker, Medtronic, Boston Scientific.
Journal Article
The Effectiveness of Grain Refinement by Machine Hammer Peening in High Deposition Rate Wire-Arc AM Ti-6Al-4V
Surface deformation, applied in-process by machine hammer peening (MHP), has the potential to refine the coarse columnar β-grain structures normally found in high deposition rate Wire-Arc Additive Manufacturing (WAAM) processes with Ti alloys like Ti-6Al-4V. Effective refinement, as well as a reduction in texture strength, has been achieved in relatively thick sections and to a depth that is greater than that expected from the surface deformation induced by MHP. By application of MHP to each deposition track, the average β-grain size could be reduced from cm’s to less than 0.5 mm. Systematic experiments have been performed to investigate the origin of this interesting effect, which included ‘stop-action’ trials and separation of the strain and temperature gradients induced by the two process steps. The maximum depth of the plastic deformation from MHP required to generate new β-grain orientations was determined by electron backscatter diffraction local average misorientation analysis to be < 0.5 mm, which was less than the melt pool depth in the WAAM process. Nevertheless, new β-grain orientations were observed to form within the peened layer ahead of the approaching heat source as the peak temperature rose above the β transus, which then grew into the less deformed core of the wall as the temperature rose. This allowed the new grain orientations to penetrate deeper than the melt pool depth and survive to act as substrates for epitaxial growth at the fusion boundary during solidification, resulting in significant grain refinement.
Journal Article
Impact of model uncertainty on SPARC operating scenario predictions with empirical modeling
Understanding and accounting for uncertainty is one aspect of ensuring next-step tokamaks such as SPARC will robustly achieve their goals. While traditional Plasma OPerating CONtour (POPCON) analyses guide design, they often overlook the significant impact of uncertainties in scaling laws, plasma profiles, and impurity concentrations on performance predictions. This work confronts these challenges by introducing statistical POPCONs, which leverage Monte Carlo analysis to quantify the sensitivity of SPARC’s operating points (Creely et al 2020 J. Plasma Phys. 86 5) to these crucial variables. For profiles, a physically motivated gradient-based functional form is introduced. We further develop a multi-fidelity Bayesian optimization workflow that effectively identifies operating points maximizing the probability of meeting performance goals, which gives a significant speed-up over brute force search methods. Our findings reveal that accounting for these uncertainties leads to an optimal operating point different from deterministic predictions, which balances H-mode access, confinement, impurity dilution, and auxiliary power.
Journal Article