Lattice collapsing transformation

Fig. 8. a Isothermal DTA trace showing the endotherm connected with the Na-Pl Na-P2 transformation b DTA curve of Ba-exchanged Linde A zeolite, showing the sharp endotherm connected with lattice collapse (reproduced by permission from [35])... 

All three of these proteins are present in the lung. The lamellar bodies are secreted into alveolar lumen where they are transformed into an extracellular form of surfactant that has a quadratic lattice structure called tubular myelin. The three-dimensional tubulin-myelin structures spread in a monolayer at the air-liquid interface. This spreading decreases the surface tension, prevents alveolar collapse at the end of expiration, and confers mechanical stability to the alveoli. The surfactant system is in a continuous state of flux, and surfactant is recycled by uptake... 

On the other hand, the collapse of a chain in a dilute solution, when the temperature decreases, was first seen by simulation calculations on lattices (Fisher and Hiley 1961, and others) and later was observed by light scattering (Mazur and McIntyre 1976) and by neutron scattering (Cotton 1978). The question was also examined by Soviet physicists who, while studying protein denaturation, took an interest in the coil-globule transition. In particular, Ilia Lifshitz and his students studied this transition from a theoretical point of view, and developed an approximation which reduces this transformation to the liquid-gas transition. 

It is quite likely that the /3 a transformation is partly a shear transformation involving the motion of atoms from a dhcp lattice to a fee lattice, but in addition there is a large volume collapse ( 17%) occurring approximately... 

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