Crystal Chemistry of the Copper Oxalate Biomineral Moolooite: The First Single-Crystal X-ray Diffraction Studies and Thermal Behavior.

Moolooite, Cu(CO)·HO, is a typical biomineral which forms due to Cu-bearing minerals coming into contact with oxalic acid sources such as bird guano deposits or lichens, and no single crystals of moolooite of either natural or synthetic origin have been found yet. This paper reports, for the first time, on the preparation of single crystals of a synthetic analog of the copper-oxalate biomineral moolooite, and on the refinement of its crystal structure from the single-crystal X-ray diffraction (SCXRD) data. Along with the structural model, the SCXRD experiment showed the significant contribution of diffuse scattering to the overall diffraction data, which comes from the nanostructural disorder caused by stacking faults of Cu oxalate chains as they lengthen.

Solid Solutions of Lindbergite-Glushinskite Series: Synthesis, Ionic Substitutions, Phase Transformation and Crystal Morphology.

To clarify the crystal chemical features of natural and synthetic oxalates Me2+(C2O4)∙2H2O (Me2+ = Fe, Mn, Mg, Zn), including minerals of the humboldtine group, solid solutions of lindbergite Mn(C2O4)∙2H2O−glushinskite Mg(C2O4)∙2H2O were precipitated under various conditions, close to those characteristic of mineralization in biofilms: at the stoichiometric ratios ((Mn + Mg)/C2O4 = 1) and non-stochiometric ratios ((Mn + Mg)/C2O4 < 1), in the presence and absence of citrate ions. Investigation of precipitates was carried out by powder X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Thermodynamic modelling was performed in order to evaluate the lindbergite−glushinskite equilibrium.

Biofilm Medium Chemistry and Calcium Oxalate Morphogenesis.

The present study is focused on the effect of biofilm medium chemistry on oxalate crystallization and contributes to the study of the patterns of microbial biomineralization and the development of nature-like technologies, using the metabolism of microscopic fungi. Calcium oxalates (weddellite and whewellite in different ratios) were synthesized by chemical precipitation in a weakly acidic environment (pH = 4-6), as is typical for the stationary phase of micromycetes growth, with a ratio of Ca/CO = 4.0-5.

[ASSESSMENT OF THE QUALITY OF DRINKING WATER AND RISK FOR THE POPULATION'S HEALTH IN RURAL TERRITORIES IN THE IRKUTSK REGION].

The hygienic analysis of centralized and decentralized water supply in rural population in Irkutsk region was performed. About 403 thousand of the upstaters use water wells, voids and springs. In drinking water there were detected significant concentrations of iron, nitrates, manganese.

[The activity of components of system of matrix metalloproteinase and tissue inhibitors of metalloproteinase on different stages of chronic cardiac failure].

The article discusses the results of detection of activity of matrix metalloproteinase-9, tissue inhibitors of metalloproteinases-4, endotoxin, tumor necrosis factor-alpha, C-reactive protein, sE-selectine in blood of patients with chronic cardiac failure depending on severity of disease. It is demonstrated that progressing of chronic cardiac failure is associated with the increase of level of endotoxemia, activation of systemic inflammation and misbalance in the system of matrix metalloproteinase and tissue inhibitors of metalloproteinase.