Variations in the chemical structure and Carbon-13 natural abundance in water-stable macro- and microaggregates in Haplic Chernozem under the contrasting land use variants.

Water-stable macro- (WSA) and free microaggregates (WSA) were isolated from the 2-1 mm air-dry macroaggregates from the surface horizons of Haplic Chernozem in contrasting variants of land use: the steppe and the bare fallow. The C NMR data and the C natural abundance of the Occluded organic matter (OM) (LF) and Clay within WSAs in the steppe obviously indicate a lower degree of microbiological processing of OM within WSA as compared with WSA. This is reflected in lower degrees of decomposition (DI) and aromaticity (ARI) of OM and the C/N ratio, as well as lower C enrichment.

Features of the chemical structure of different organic matter pools in Haplic Chernozem of the Streletskaya steppe: C MAS NMR study.

The aim of the current research was to study structural features of four organic matter (OM) pools isolated by the modified method of granulo-densimetric fractionation from two Сhernozems. We purposed to relate these features to the OM allocation and the transformation processes. The pools included: 1) free light fraction located in an inter-aggregate space, 2) light fraction occluded inside the microaggregates, 3) OM bound with clay particles, and 4) OM bound with a residual heavy fraction left after light fractions and clay separation.

Short-term bioavailability of carbon in soil organic matter fractions of different particle sizes and densities in grassland ecosystems.

The quality, stability and availability of organic carbon (OC) in soil organic matter (SOM) can vary widely between differently managed ecosystems. Several approaches have been developed for isolating SOM fractions to examine their ecological roles, but links between the bioavailability of the OC of size-density fractions and soil microbial communities have not been previously explored. Thus, in the presented laboratory study we investigated the potential bioavailability of OC and the structure of associated microbial communities in different particle-size and density fractions of SOM.

Family medicine in the Russian far East.

Background And Objectives: Over the last decade, Russia and other former Soviet states have attempted to move from a fragmented health care system dominated by specialty and hospital care to one emphasizing primary care and prevention through the introduction of family medicine. This report describes the development of family medicine in Russia's Far East region.

Methods: The Far East was one of the first places in Russia to develop family medicine education.

[Effect of C.P.Fëdorov's approach on morphology and function of the anterior abdominal wall according to the findings of ultrasonic examination].

Echolocation was accomplished by means of "Alok-650" echochamber (Japan) and 3.5 and 5 megahertz transducers. Twenty individuals of the control group and 40 patients who underwent operations on the extrahepatic bile ducts and the gallbladder through S.