Improvement of gas exchange through closer matching of regional ventilation (V) and lung perfusion (Q) with the application of positive end-expiratory pressure (PEEP) was evaluated in vivo in six mechanically ventilated preterm lambs (107-126 days/145 days gestation). Changes in V and Q were determined from in vivo scintigraphic measurements in four lung regions with inhaled radioactive 81mKr, and ...

Pyrochlore antiferromagnet is one of the most studied examples of strongly-interacting systems. The conflict between the lattice geometry and the local spin correlations favored by their interactions precludes the simple Neel ordering and creates an extensive degeneracy of the classical ground state. This, in turn, renders the magnet susceptible to nominally small perturbations such as quantum ...