Helicity hardens the gas

A screw generally works better than a nail, or a complicated rope knot better than a simple one, in fastening solid matter, but a gas is more tameless. However, a flow itself has a physical quantity, helicity, measuring the screwing strength of the velocity field and the degree of the knottedness of the vorticity ropes. It is shown that helicity favors the partition of energy to the vortical modes, compared to others such as the dilatation and pressure modes of turbulence; that is, helicity stiffens the flow, with nontrivial implications for aerodynamics, such as aeroacoustics, and conducting fluids, among others

Galantamine protects against hydrochloric acid aspirationinduced acute respiratory distress syndrome in rabbits

Purpose: To study the effect of galantamine on anti-inflammatory responses in acid aspiration-induced acute respiratory syndrome (ARDS), and the underlying mechanism.Methods: Six groups of male rabbits (156), i.e., control group, ARDS group, galantamine + ARDS (GAL) group, galantamine + ARDS + methyllycaconitine (MLA) group, galantamine + ARDS + vagotomy (Vag) group, and galantamine + ARDS + atropine sulfate (ATS) group. ARDS model was produced by acid aspiration. After 4 h, TNF-α, IL-6 and IL-1β were assayed in lung tissue, while corticosterone levels were determined in blood. Histopathological lesions and wet-to-dry (W/D) weight ratio of lung tissue (n = 10) were assessed. After 12 h, HMGB1 protein and corticosterone levels were determined in lung tissue and blood, respectively. Mortality rate was determined after 72 h.Results: Acid aspiration-induced ARDS induced disorganization of lung structure, and elevated TNF-α, IL-6, IL-1β, and HMGB1activities, and lung W/D weight ratio. The acid-induced ARDS, as well as increases in W/D weight ratio, pro-inflammatory cytokines and lung lesions were significantly decreased by galantamine pretreatment. Methyllycaconitin, vagotomy and atropine sulfate abolished the galantamine-induced suppression of acute inflammatory response, pathological changes in lungs, and W/D weight ratio. However, serum corticosterone levels were not significantly altered in each group.Conclusion: Galantamine reduces inflammation in acid aspiration-induced ARDS by the cholinergic anti-inflammatory pathway.Keywords: Galantamine, Hydrochloric acid, Aspiration-induced, Respiratory distress syndrome, Methyllycaconitin, Vagotomy, Atropine sulfat