An experimental study of optical anomalies in solid solutions of alums in relation to their composition, growth temperatures and rates, and hydrodynamic regime was carried out. Theoretical analysis of the data showed that they can be understood in terms of a mechanism of kinetic ordering of the isomorphous atoms (the phenomenon of so-called ‘growth dissymmetrization’). A theoretical model is presented which is supported by data for a number of minerals and synthetic compounds, which are known for their optical anomalies due to growth dissymmetrization.

Oscillatory zoning in solid solutions of alums ((K,NH4)Al(SO4)2·12H2O, K(Al,Cr)(SO4)2·12H2O, (K,Rb)Al(SO4)2·12H2O) and nitrates of divalent metals ((Sr,Pb)(NO3)2, (Ba,Pb)(NO3)2) grownfrom low-temperature aqueous solutions is considered. The zoning is detected by means of X-ray diffraction topography, crystal optics and electron probe microanalysis and involves variations of the crystal composition and degree of the growth ordering of atoms. The zoning patterns are very different in the predominant ﹛111﹜ and ﹛1̄11﹜ and subordinate ﹛100﹜ and ﹛110﹜ growth sectors. The different types of micromorphological instabilities of a growing face are suggested to explain the origin of the observed zoning.

Adjuvants are substances that enhance adaptive immune responses when formulated in a vaccine. Alum and MF59 are two vaccine adjuvants licensed for human vaccination. Their mode of action has not been completely elucidated. Here we show the first ultrastructural visualization of Alum and MF59 interaction with immune cells in vitro and in vivo. We observed that Alum is engulfed by cells as inclusions of laminae that are detectable within draining lymph nodes. MF59 is instead engulfed by cells in vitro as low-electron-dense lipid-like inclusions that display a vesicle pattern, as confirmed by confocal microscopy using fluorescently labeled MF59. However, lipid-like inclusions with different high- and low-electron-dense content are detected within cells of draining lymph nodes when injecting MF59. As high-electron-dense lipid-like inclusions are also detected upon injection of Alum, our results suggest that the low-electron-dense inclusions are formed by engulfed MF59, whereas the high-electron-dense inclusions are proper lipid inclusions. Thus, we demonstrated that vaccine adjuvants are engulfed as inclusions by lymph node cells and hypothesize that adjuvant treatment may modify lipid metabolism.