Influence of rare earth metals on volumetric characteristics of Al-Ni-Co-R alloys in crystalline and liquid states.

Density of Al-Ni-Co-R (R = Nd, Sm, Gd, Tb, Yb) glass-forming alloys is studied experimentally by gamma-absorption method in a wide temperature range including crystalline and liquid states. Molar volumes and thermal expansion coefficients are calculated from the experimental data. It is shown that these melts remain strongly microheterogeneous systems at small overheatings above liquidus. Some regimes of melt heat treatment before quenching are discussed.

Comparison of the ultrastructure of small dense forms of chlamydiae and Coxiella burnetii.

In the course of passaging of Coxiella burnetii (C.b.) in Alveonasus lahorensis ticks, the haemocytes contained cell forms with electrondense cytoplasm, intracytoplasmic lamellar membranes, and a peculiar limiting membrane--25 to 30 nm thick "envelope complex". Similar small forms occurred when C.b. had been cultured in the yolk sack of chick embryos. The dense forms of C.b. were similar to those of Rickettsiella cells. Dense forms (elementary bodies) surrounded by an "envelope complex" were found also in some chlamydiae cultured in yolk sacs of chick embryos.

Interaction of rickettsiae with haemocytes of Alveonasus lahorensis ticks.

The development of different rickettsial species (Rickettsia sibirica, R. conorii, R. acari and coxiella burnetii) in haemocytes of Alveonasus lahorensis ticks was compared by viral observations and time-lapse cine-micrography. The interaction of different rickettsial species with the haemocytes in vitro had specific characteristic features and reflected the pattern of interaction of the rickettsiae with tick cells in vivo.

[Formation of membranes of the basic substance by hemocytes of Alveonasus lahorensis (Argasidae) ticks]. / Obrazovanie membran osnovnogo veshchestva gemotsitami kleshchei Alveonasus lahorensis (Argasidae).

Observations have shown that in vitro haemocytes of A. lahorensis are capable of forming different structures, even membrane ones. These structures include mucopolysaccharides. Haemocytes are supposed to take part in the formation and deposition of the basic (intercellular) substance and in the building of tunica propria which can be considered as components of the inner medium.