Aging, jamming, and the limits of stability of amorphous solids

Apart from not having crystallized, supercooled liquids can be considered as being properly equilibrated and thus can be described by a few thermodynamic control variables. In contrast, glasses and other amorphous solids can be arbitrarily far away from equilibrium and require a description of the history of the conditions under which they formed. In this paper we describe how the locality of interactions intrinsic to finite-dimensional systems affects the stability of amorphous solids far off equilibrium. Our analysis encompasses both structural glasses formed by cooling and colloidal assemblies formed by compression. A diagram outlining regions of marginal stability can be adduced which bears some resemblance to the quasi-equilibrium replica meanfield theory phase diagram of hard sphere glasses in high dimensions but is distinct from that construct in that the diagram describes not true phase transitions but kinetic transitions that depend on the preparation protocol. The diagram exhibits two distinct sectors. One sector corresponds to amorphous states with relatively open structures, the other to high density, more closely-packed ones. The former transform rapidly owing to there being motions with no free energy barriers; these motions are string-like locally. In the dense region, amorphous systems age via compact activated reconfigurations. The two regimes correspond, in equilibrium, to the collisional or uniform liquid and the so called landscape regime, respectively. These are separated by a spinodal line of dynamical crossovers. Owing to the rigidity of the surrounding matrix in the landscape, high-density part of the diagram, a sufficiently rapid pressure quench adds compressive energy which also leads to an instability toward string-like motions with near vanishing barriers. (SEE REST OF ABSTRACT IN THE ARTICLE.)Comment: submitted to J Phys Chem

A predictive inline model for nonlinear stimulated Raman scattering in a hohlraum plasma

In this Letter, we introduce a new inline model for stimulated Raman scattering (SRS), which runs on our radiation hydrodynamics code TROLL. The modeling follows from a simplified version of a rigorous theory for SRS, which we describe, and accounts for nonlinear kinetic effects. It also accounts for the SRS feedback on the plasma hydrodynamics. We dubbed it PIEM because it is a fully PredIctivE Model, no free parameter is to be adjusted \textit{a posteriori}~in order to match experimental results. PIEM predictions are compared against experimental measurements performed at the Ligne d'Int\'egration Laser. From these comparisons, we discuss PIEM ability to correctly catch the impact of nonlinear kinetic effects on SRS

Le patrimoine est-il fréquentable ?

Le thème de la fréquentation du patrimoine subit une injonction paradoxale. D\u27un côté, des pressions s\u27exercent pour que le peuple admire les sites le plus remarquables ; de l\u27autre, d\u27aucuns n\u27ont de cesse de prôner la limitation de l\u27accès au nom des risques encourus, rejoints pas d\u27autres au nom de l\u27incapacité que le plus grand nombre aurait à comprendre et à profiter à bon escient de ce bienfait. Pourtant, les lieux les plus fréquentés sont les mieux conservés et les héritages sont surtout menacés par l\u27oubli. Dès lors, les enjeux se situent dans la qualité de l\u27ouverture. D\u27une part, l\u27accessibilité et les visites peuvent être gérées de manière à prendre en compte à la fois la protection et les attentes des visiteurs. D\u27autre part, la connaissance du patrimoine, qui constitue une des clés de l\u27appréciation de la visite, peut être apportée par des techniques d\u27interprétation, sans pour autant constituer la seule modalité de l\u27expérience vécue

Hidden fluctuations close to a quantum bicritical point

Here, we present an alternative approach for the description of quantum critical fluctuations. These are described by Langevin random fields, which are then related to the susceptibility using the fluctuation-dissipation theorem. We use this approach to characterize the physical properties arising in the vicinity of two coupled quantum phase transitions. We consider a phenomenological model based on two scalar order parameter fields locally coupled biquadratically and having a common quantum critical point as a function of a quantum tuning parameter such as pressure or magnetic field. A self-consistent treatment shows that the uniform static susceptibilities of the two order parameter fields have the same qualitative form at low temperature even where the forms are different in the absence of the biquadratic coupling.We acknowledge support from EPSRC, Corpus Christi College, the National Science Foundation Grant No. NSF DMR-1334428, and the Increase Competitiveness Program of the Ministry of Education of the Russian Federation Grant No. NUST MISiS K2-2017-024. We are grateful to Trinity College Cambridge, the Cavendish Laboratory, and the Aspen Center for Physics, supported by National Science Foundation Grant No. NSF PHY-1066293, for hospitality. S.E.R. acknowledges support from a CONFAP Newton grant

Treatment of bronchial airway obstruction using a rotating tip microdebrider: a case report

BACKGROUND: Central airway obstruction is a common complication of lung cancer. The microdebrider is a new device available for treatment of central airway obstruction. CASE DESCRIPTION: We report a case a 59-yr-old male with T3N2M1 non-small cell lung cancer with malignant distal left mainstem obstruction treated successfully with a novel elongated rotating tip microdebrider via rigid bronchoscopy with sufficient length to reach distal bronchial lesions. DISCUSSION AND CONCLUSION: The microdebrider is an excellent addition to the spectrum of interventions available for the management of central airway obstruction with advantages including accuracy and immediate removal of debris without a need for separate suctioning or limitation in oxygenation

Cost-effectiveness of stepwise provisional versus systematic dual stenting strategies in patients with distal bifurcation left main stem lesions: Economic analysis of the EBC MAIN trial

\ua9 2024 BMJ Publishing Group. All rights reserved.Background In patients with distal bifurcation left main stem lesions requiring intervention, the European Bifurcation Club Left Main Coronary Stent Study trial found a non-significant difference in major adverse cardiac events (MACEs, composite of all-cause death, non-fatal myocardial infarction and target lesion revascularisation) favouring the stepwise provisional strategy, compared with the systematic dual stenting. Aims To estimate the 1-year cost-effectiveness of stepwise provisional versus systematic dual stenting strategies. Methods Costs in France and the UK, and MACE were calculated in both groups to estimate the incremental cost-effectiveness ratio (ICER). Uncertainty was explored by probabilistic bootstrapping. The analysis was conducted from the perspective of the healthcare provider with a time horizon of 1 year. Results The cost difference between the two groups was €-755 (€5700 in the stepwise provisional group and €6455 in the systematic dual stenting group, p value<0.01) in France and €-647 (€6728 and €7375, respectively, p value=0.08) in the UK. The point estimates for the ICERs found that stepwise provisional strategy was cost saving and improved outcomes with a probabilistic sensitivity analysis confirming dominance with an 80% probability. Conclusion The stepwise provisional strategy at 1 year is dominant compared with the systematic dual stenting strategy on both economic and clinical outcomes