Low temperature short-range ordering caused by Mn²(+) doping of Rb₃H(SO₄)₂.

The low temperature behaviour of Rb₃H(SO₄)₂ and Rb₃D(SO₄)₂ and their doped analogues was investigated by means of their dielectric response. Electron paramagnetic resonance was used to control the impurity concentration. Influence of different admixtures on ferroic properties is discussed.

Multiferroic BiFeO3 nanoparticles studied by electron spin resonance, X-ray diffraction and transmission electron microscopy methods.

The properties of multiferroic BiFeO3 nanoparticles with core-shell structure produced by mechanically activated room temperature synthesis were studies by electron spin resonance spectroscopy and X-ray diffraction. The data reveal essential differences in ordered and disordered regions among as-prepared and annealed samples. The thermally-induced increase in the average size of the grains and disappearance of the disordered grain shell determined from the electron spin resonance and X-ray diffraction are in a good agreement and were confirmed by transmission electron microscopy observations.

Metabolic and ultrastructural responses of lupine embryo axes to sugar starvation.

Embryo axes isolated from germinating lupine seeds were cultivated in vitro for 24-96 h over media containing either 60 mmol/L sucrose or no sucrose. Ultrastructural studies showed that large vacuoles were accumulating in a central region of primary parenchyma cells in sucrose starved lupine embryo axes, whereas cytoplasm along with organelles were forced to a periphery of the cells. We suggest that the autolysis of cytoplasmic proteins contributes to the accumulation of the vacuoles and this suggestion is consistent with the results of the characterisation of protein content.