Short-range correlation of stress chains near solid-to-liquid transition in active monolayers.

Using a three-dimensional model of cell monolayers, we study the spatial organization of active as the monolayer transitions from a solid to a liquid state. The critical exponents that characterize this transition map the isotropic stress percolation onto the two-dimensional random percolation universality class, suggesting short-range stress correlations near this transition. This mapping is achieved via two distinct, independent pathways: (i) cell-cell adhesion and (ii) active traction forces.

Tunable Mechanical Response of Self-Assembled Nanoparticle Superlattices.

Self-assembled nanoparticle superlattices (NPSLs) are an emergent class of self-architected nanocomposite materials that possess promising properties arising from precise nanoparticle ordering. Their multiple coupled properties make them desirable as functional components in devices where mechanical robustness is critical. However, questions remain about NPSL mechanical properties and how shaping them affects their mechanical response.

Unearthing real-time 3D ant tunneling mechanics.

Granular excavation is the removal of solid, discrete particles from a structure composed of these objects. Efficiently predicting the stability of an excavation during particle removal is an unsolved and highly nonlinear problem, as the movement of each grain is coupled to its neighbors. Despite this, insects such as ants have evolved to be astonishingly proficient excavators, successfully removing grains such that their tunnels are stable.

Structured fabrics with tunable mechanical properties.

Structured fabrics, such as woven sheets or chain mail armours, derive their properties both from the constitutive materials and their geometry. Their design can target desirable characteristics, such as high impact resistance, thermal regulation, or electrical conductivity. Once realized, however, the fabrics' properties are usually fixed.

Effect of Confinement on Capillary Phase Transition in Granular Aggregates.

Using a 3D mean-field lattice-gas model, we analyze the effect of confinement on the nature of capillary phase transition in granular aggregates with varying disorder and their inverse porous structures obtained by interchanging particles and pores. Surprisingly, the confinement effects are found to be much less pronounced in granular aggregates as opposed to porous structures. We show that this discrepancy can be understood in terms of the surface-surface correlation length with a connected path through the fluid domain, suggesting that this length captures the true degree of confinement.

Use of the abatacept in a patient with psoriatic arthritis.

Psoriatic arthritis (PA) is an inflammatory seronegative arthritis of unknown origin. Classically, PA has five clinical forms, and asymmetric oligoarthritis is the most common type. We describe the case of a patient with PA refractory to disease-modifying drugs, who developed drug-induced hepatitis after chemoprophylaxis with isoniazid, administered prior to the treatment with an anti-TNFα agent.