Sublithospheric diamond ages and the supercontinent cycle.

Subduction related to the ancient supercontinent cycle is poorly constrained by mantle samples. Sublithospheric diamond crystallization records the release of melts from subducting oceanic lithosphere at 300-700 km depths and is especially suited to tracking the timing and effects of deep mantle processes on supercontinents. Here we show that four isotope systems (Rb-Sr, Sm-Nd, U-Pb and Re-Os) applied to Fe-sulfide and CaSiO inclusions within 13 sublithospheric diamonds from Juína (Brazil) and Kankan (Guinea) give broadly overlapping crystallization ages from around 450 to 650 million years ago.

Determination of Hydroxychloroquine by Cathodic Electrochemiluminescence.

Cathodic electrochemiluminescence (CECL) of hydroxychloroquine (HCQ) in aqueous solutions on an aluminum electrode is described. The analytical possibilities of the phenomenon are evaluated. The conditions for HCQ determination in slightly alkaline and acidic solutions are optimized.

Influence of Microbial Metabolites on the Nonspecific Permeability of Mitochondrial Membranes under Conditions of Acidosis and Loading with Calcium and Iron Ions.

Mitochondrial dysfunction is currently considered one of the main causes of multiple organ failure in chronic inflammation and sepsis. The participation of microbial metabolites in disorders of bioenergetic processes in mitochondria has been revealed, but their influence on the mitochondrial membrane permeability has not yet been studied. We tested the influence of various groups of microbial metabolites, including indolic and phenolic acids, trimethylamine-N-oxide (TMAO) and acetyl phosphate (AcP), on the nonspecific permeability of mitochondrial membranes under conditions of acidosis, imbalance of calcium ions and excess free iron, which are inherent in sepsis.

Incidence risk of bronchopneumonia in newborn calves associated with intrauterine diselementosis.

Background And Aim: Macro- and micro-elements are required to ensure the normal course of biochemical processes in the development of an animal's body. Any excess, deficiency, or imbalance in chemical elements in an animal's body can cause the development of various latent or clinically expressed pathological conditions. Diselementosis in pregnant cows may lead to impaired embryo and fetal development, as well as reduced neonatal viability.

Draft genome sequence data and analysis of sp. strain JR1-6 isolated from nitrate- and radionuclide-contaminated groundwater in Russia.

sp. strain JR1-6 is a Gram-negative, facultatively anaerobic, non-spore-forming, motile, rod-shaped bacterium isolated from radionuclide- and nitrate-contaminated groundwater. This bacterium reduces nitrate to N2.

Whole-genome sequence data and analysis of type strains ' and ' isolated from nitrate- and radionuclide-contaminated groundwater in Russia.

Two strains, ' JR1/69-2-13 and ' JR1/69-3-13, of aerobic, motile, Gram-negative, non-spore-forming, organotrophic, psychrotolerant bacteria were isolated from a sample of nitrate- and radionuclide-contaminated groundwater in Russia. Here we describe the draft genomes of these strains. The sequenced and annotated genome of the strain JR1/69-2-13 contained 4.

Microbial Community and Bioremediation of Groundwater by Nitrate Removal in the Zone of a Radioactive Waste Surface Repository.

The goal of the present work was to investigate the physicochemical and radiochemical conditions and the composition of the microbial community in the groundwater of a suspended surface repository for radioactive waste (Russia) and to determine the possibility of groundwater bioremediation by removal of nitrate ions. Groundwater in the repository area (10-m depth) had elevated concentrations of strontium, tritium, nitrate, sulfate, and bicarbonate ions. High-throughput sequencing of the V3-V4/V4 region of the 16S rRNA gene revealed the presence of members of the phyla (genera , and uncultured ), (genera and ), and ( Planktophila, ).

Discovery of a silicate rock-boring organism and macrobioerosion in fresh water.

Macrobioerosion is a common process in marine ecosystems. Many types of rock-boring organisms break down hard substrates, particularly carbonate rocks and calcareous structures such as dead corals and shells. In paleontology, the presence of rocks with boreholes and fossil macroboring assemblage members is one of the primary diagnostic features of shallow marine paleo-environments.

Draft Genome Sequence of Roseomonas aestuarii Strain JR1/69-1-13 Isolated from Nitrate- and Radionuclide-Contaminated Groundwater in Russia.

The draft genome sequence of strain JR1/69-1-13, an aerobic chemoorganotrophic bacterium isolated from nitrate- and radionuclide-contaminated groundwater in Russia, is presented here. The genome was annotated to elucidate the genomic basis for the strain's adaptation to the environment and its resistance to nitrate, heavy metals, and metalloids.

Draft Genome Sequence of a Dissimilatory U(VI)-Reducing Bacterium, Shewanella xiamenensis Strain DCB2-1, Isolated from Nitrate- and Radionuclide-Contaminated Groundwater in Russia.

Here, we describe the draft genome sequence of strain DCB2-1, isolated from nitrate- and radionuclide-contaminated groundwater. This strain is able to reduce nitrate, Tc(VII), Cr(VI), Fe(III), and U(VI), and its genome sequence contains several gene sets encoding denitrification, resistance to heavy metals, and reduction of metals and metalloids.

Boninite-like intraplate magmas from Manihiki Plateau require ultra-depleted and enriched source components.

The Ontong Java and Manihiki oceanic plateaus are believed to have formed through high-degree melting of a mantle plume head. Boninite-like, low-Ti basement rocks at Manihiki, however, imply a more complex magma genesis compared with Ontong Java basement lavas that can be generated by ∼30% melting of a primitive mantle source. Here we show that the trace element and isotope compositions of low-Ti Manihiki rocks can best be explained by re-melting of an ultra-depleted source (possibly a common mantle component in the Ontong Java and Manihiki plume sources) re-enriched by ≤1% of an ocean-island-basalt-like melt component.

Solid-phase extraction of plutonium in various oxidation states from simulated groundwater using -benzoylphenylhydroxylamine.

Solid-phase extraction of plutonium in different individual and mixed oxidation states from simulated groundwater (pH 8.5) was studied. The extraction of plutonium species was carried out in a dynamic mode using DIAPAK C16 cartridges modified by -benzoylphenylhydroxylamine (BPHA).

Concept of sustained ordering and an ATP-related mechanism of life's origin.

This paper shows that the steady state of a system of conjugated reactions, which are characterized by disproportionation of entropy and proceed in the domain of linear interactions, is an attractor of ordering. Such systems are primed to produce ordering, and life is a specific manifestation of the sustained ordering inherent to the chemistry of carbon. The adenosine triphospate (ATP) molecule has properties which makes ATP hydrolysis to be most appropriate to form such a system in primitive world.

A quantitative link between recycling and osmium isotopes.

Recycled subducted ocean crust has been traced by elevated 187Os/188Os in some studies and by high nickel and low manganese contents in others. Here, we show that these tracers are linked for Quaternary lavas of Iceland, strengthening the recycling model. An estimate of the osmium isotopic composition of both the recycled crust and the mantle peridotite implies that Icelandic Quaternary lavas are derived in part from an ancient crustal component with model ages between 1.

137Cs and 40K in the terrestrial vegetation of the Yenisey Estuary: landscape, soil and plant relationships.

Plant species, forming important components of Arctic food chains and of interest from a monitoring perspective, were studied at 36 plots representing flood plain and terrace landscapes of the Yenisey River and Estuary from its upper delta to the gulf. (137)Cs contamination densities at the plots varied from 0.35kBq/m(2) (central delta, sandy riverside plot) to 88kBq/m(2) (the upper delta plot) indicating both global and regional sources of anthropogenic pollution.

Isotopic self-exchange reactions of water: evaluation of the rule of the geometric mean in liquid-vapor isotope partitioning.

Deviations from the random distribution of hydrogen isotopes among isotopic species of liquid and vapor water (the rule of the geometric mean) were critically assessed theoretically and experimentally from the triple to critical point of water. A third-order polynomial equation of the classical near-critical expansion was used to accurately describe the liquid-vapor isotope fractionation of H2O and D2O on the basis of their equations of state. It was found that experimental data for the enthalpy of mixing of H2O-D2O can be used to calculate accurately the deviation from the rule of the geometric mean in liquid and vapor water, ln(KD(v)/KD(l)).

Peculiarities of the distribution of man-made radionuclides in several European seas.

Results of a study on the distribution of the man-made radionuclides 137Cs and 90Sr in the surface waters of several European seas are presented. Based on an analysis of the ratio of these two radionuclides, an attempt was made to isolate the 'Chernobyl water' and to estimate the contribution of 'Chernobyl radioactivity' to the total radioactivity in the waters of the seas investigated.

Biogeochemical regioning problems and the biogeochemical selenium provinces in the former USSR.

Current trends in biogeochemical research in the former USSR are exemplified for the trace element selenium (Se). Vast regions of the former USSR are low in Se, giving rise to selenium deficiency diseases in animals and to Kaschin-Beck disease in humans, whereas isolated high-Se regions are comparatively rare. The Se content of plants depends on geological soil-type and secondary processes such as weathering and leaching.

Ascorbic acid as a matrix modifier for determination of tin in concentrated boric acid solutions by electrothermal atomic-absorption spectrometry.

It has been found that the atomic-absorption signal for tin is reduced in the presence of 5 micro1 of 0.05-0.30M boric acid at STPF-conditions.

Fluorescence determination of trace amounts of uranium(VI) in various materials by a repetitive laser technique.

A laser-induced fluorescence method (LFM) is described for determination of trace amounts of uranium(VI), with a detection limit of 4 x 10(-11) g/ml. A repetitive pulsed laser, time discrimination and an averaging technique are used. The optimum time discrimination is obtained when the uranyl ion is complexed with phosphoric acid or sodium polysilicate.

Determination of oxygen in fusible metals by use of solid electrolyte cells.

A new method has been devised for determination of oxygen in fusible metals and compounds based on them, viz., by electrochemical extraction of oxygen with the help of a specially designed solid electrolyte cell. The physiocochemical conditions for the method to be used, and the analytical characteristics, are discussed.

Recent advances in the analytical chemistry of the transplutonium elements.

A survey is given of current developments in the determination of the transplutonium elements, and of the properties useful in their analytical chemistry.

Analytical chemistry in the Soviet Union.

The history of the development of analytical chemistry in the Soviet Union is briefly outlined. Organizations co-ordinating research in this field, and the leading scientific centres, are indicated. Achievements in various analytical techniques are reviewed.

Properties and analytical application of a new membrane electrode sensitive to molybdenum(VI).

A new liquid molybdenum(VI)-sensitive electrode with a membrane based on a solution of the molybdenum(VI)-N-benzoyl-N-phenylhydroxylamine chelate is proposed and its electrochemical behaviour and applicability have been critically investigated. The transfer of molybdenum(VI) across the water-organic solvent interface and across the membrane has been studied by use of sodium molybdate labelled with (99)Mo, and the response mechanism of the electrode is discussed.

Solvent extraction-electrothermal atomic-absorption analysis.

The review discusses the problems of rational combination of solvent-extraction separation and preconcentration of trace elements with their determination by electrothermal atomic-absorption spectrometry.