Landau-Type Theory of Planar Crystal Plasticity.

We show that nonlinear continuum elasticity can be effective in modeling plastic flows in crystals if it is viewed as a Landau theory with an infinite number of equivalent energy wells whose configuration is dictated by the symmetry group GL(2,Z). Quasistatic loading can be then handled by athermal dynamics, while lattice-based discretization can play the role of regularization. As a proof of principle, we study dislocation nucleation in a homogeneously sheared 2D crystal and show that the global tensorial invariance of the elastic energy foments the development of complexity in the configuration of collectively nucleating defects. A crucial role in this process is played by the unstable higher symmetry crystallographic phases, typically thought to be unrelated to plastic flow.

Membrane-mediated interactions of rod-like inclusions.

Inclusions embedded in lipid membranes undergo a mediated force, due to the tendency of the membrane to relax its excess of elastic energy. In this paper we determine the exact shape of a two-dimensional vesicle hosting two different inclusions, and we analyse how the inclusion conformation influences the mediated interaction. We find non-trivial equilibrium configurations for the inclusions along the hosting membrane, and we derive the complete phase diagram of the mediated interaction. In particular, we find a non-vanishing mediated force even when the distance between the inclusions is much greater than their size. Our model can be applied to describe the mediated interactions of parallel, elongated inclusions embedded in three-dimensional membranes.

[Prophylaxis and treatment of bronchopulmonary complications with ambroxol administered by infusion in elderly patients undergoing surgery]. / Prevenzione e trattamento delle complicanze broncopolmonari con ambroxol per infusione negli operandi anziani.

The Authors consider the high number of patients who are affected with chronic obstructive bronchitis due to various factors (cigarettes smoking, infections, pollution, reduced immune response). These patients, when submitted to middle-high abdominal surgery in total anaesthesia of middle-long duration, are at increased risk due to pulmonary complications. Therefore, an adequate respiratory protection is necessary; actually it is possible with high dose of Ambroxol (1 g). Two groups, both of 35 patients, were compared; the first group was treated with Ambroxol 1 g the second one with aminophilline, bromexine, B2 adrenergic agonists, corticosteroids. The results show the efficacy of respiratory protection by using Ambroxol 1g.