Elemental composition of grass phytoliths: Environmental control and effect on dissolution.

Plant phytoliths, which represent the main pool of silica (Si) in the form of hydrous Si oxide, are capable of providing valuable information on different aspect of environmental issues including paleo-environmental reconstruction and agricultural sustainability. Phytoliths may have different chemical composition, which, in turn, affects their preservation in soils ad impacts terrestrial cycle of the occluded elements including micro-nutrients and environmental toxicants. Yet, in contrast to sizable work devoted to phytoliths formation, dissolution and physico-chemical properties, the mechanisms that control total (major and trace) elemental composition and the impact that various elements exert on phytolith reactivity and preservation in soils remains poorly known.

Body-centered cubic iron-nickel alloy in Earth's core.

Cosmochemical, geochemical, and geophysical studies provide evidence that Earth's core contains iron with substantial (5 to 15%) amounts of nickel. The iron-nickel alloy Fe(0.9)Ni(0.

[Cellular mechanisms of impaired cardiac energetics in patients with dilated cardiomyopathy: decrease in mitochondrial respiration and creatine kinase expression].

The mitochondrial functional characteristics were assessed in the biopsy specimens from patients with various Functional Classes dilated cardiomyopathy (DCMP). The assessment was made by using endomyocardial biopsy specimens weighing 2-4 mg which had been taken from 39 patients aged 19-64 years during coronary ventriculography and cardiac transplantation. The status of mitochondria and the efficiency of mitochondrial creatine kinase functioning were evaluated by recording the respiration of saponin-skinned muscular fibers.

Influence of a stationary magnetic field on bioelectric properties of snail neurons.

Identified cells of Helix lucorum L. received 20 min exposures to 23, 120, or 200 mT stationary magnetic field (MFs). Resting potentials and input resistances were measured.

Lipoprotein-antibody immune complexes. Their catabolism and role in foam cell formation.

Immune complexes consisting of human [125I]LDL or [125I]VLDL and anti-apo B IgG were prepared in vitro. After intravenous administration of these complexes or free LDL to normal rabbits the elimination rate for complexes was 2-3-fold higher than for free lipoproteins. The liver/spleen radioactivity ratio after administration of immune complexes was 34% less than after administration of free lipoproteins.

Pituitary gonadotropic hormone from a chondrostean fish, starred sturgeon (Acipenser stellatus Pall.) III. Polymorphism.

Four biologically active fractions of gonadotropic hormone (aci-GTH-A, -B, -C, -D) were isolated and purified from acetonized pituitaries of the starred sturgeon (Acipenser stellatus Pall.). Their separation was achieved by DEAE-cellulose chromatography.

Pituitary gonadotropic hormone from a chondrostean fish, starred sturgeon (Acipenser stellatus Pall.) IV. Differences in biological action of isoforms and absence of sex-specific forms.

The specific activities of four subfractions of the starred sturgeon (Acipenser stellatus Pall.) pituitary gonadotropin (aci-GTH-A, -B, -C, -D) were compared using several test systems. The ratios of two of them (A and D) that contained the isoforms differing by the values of isoelectric point were shown to be different, especially when in vitro oocyte maturation and spermiation tests were used.