[Gerontological aspects of the demographic situation in the Belgorod region, 2010-2018.]

In the Belgorod region during 2010-2018 the total number of the population slightly increased by 1,3%, until 2017 only because of migratory gain. After 2018 it does not compensate natural decrease of the population. During the analyzed period from 2010 to 2018 the negative demographic trends which are characterized by depopulation owing to decrease in birth rate, growth of mortality and ageing of the population took place.

[Age characteristics of primary disability of adult population due to diseases of digestive organs in the Belgorod region during 2010-2018.]

The analysis of indicators of primary disability due to diseases of digestive organs among pension age and working-age population of the Belgorod region is carried out in comparative aspect with the national indicators during 8 years. Rank places of diseases of digestive organs in structure of primary disability were defined. The revealed main features and trends of disability, were investigated to further optimization of medico-social service and improved support to this contingent of disabled people.

Synthesis and magnetic properties of the chromium-doped iron sulfide Fe1-xCrxS single crystalline nanoplates with a NiAs crystal structure.

Single crystalline iron sulfide nanoparticles doped with chromium Fe1-xCrxS (0 ≤x≤ 0.15) have been successfully prepared by a thermal decomposition method. The particles are self-organized into the single crystalline plates with the accurate hexagonal shape and dimensions up to 1 µ in plane and about 30-40 nm in thickness. The samples have the NiAs-type crystal structure (P63/mmc) at all Cr concentrations up to x = 0.15. Fe(57)-Mössbauer spectroscopy data reveal four nonequivalent iron sites in these nanocrystals related to the different number of cation vacancies in neighboring of the iron atoms. A 2C-type superstructure or a mixture of 2C and 3C superstructures of vacancy ordering can appear in these samples. It was established that in the Fe1-xCrxS series chromium prefers to replace iron in the cation layers containing vacancies at 0.00 < x < 0.10 and Cr atoms occupy both iron and vacant sites at x > 0.10. The specific magnetic properties, which can be tuned by chromium doping, enable potential applications of these nanoparticles in technical devices using the material with thermally activated magnetic memory, for example, switches or storages.

Structural, magnetic, and electronic properties of iron selenide Fe6-7Se8 nanoparticles obtained by thermal decomposition in high-temperature organic solvents.

Iron selenide nanoparticles with the NiAs-like crystal structure were synthesized by thermal decomposition of iron chloride and selenium powder in a high-temperature organic solvent. Depending on the time of the compound processing at 340 °C, the nanocrystals with monoclinic (M)-Fe3Se4 or hexagonal (H)-Fe7Se8 structures as well as a mixture of these two phases can be obtained. The magnetic behavior of the monoclinic and hexagonal phases is very different. The applied-field and temperature dependences of magnetization reveal a complicated transformation between ferrimagnetic (FRM) and antiferromagnetic (AFM) structures, which can be related to the spin rotation process connected with the redistribution of cation vacancies. From XRD and Mössbauer data, the 3c type superstructure of vacancy ordering was found in the hexagonal Fe7Se8. Redistribution of vacancies in Fe7Se8 from random to ordered leads to the transformation of the magnetic structure from FRM to AFM. The Mössbauer data indicate that vacancies in the monoclinic Fe3Se4 prefer to appear near the Fe(3+) ions and stimulate the magnetic transition with the rotation of the Fe(3+) magnetic moments. Unusually high coercive force Hc was found in both (H) and (M) nanocrystals with the highest ("giant") value of about 25 kOe in monoclinic Fe3Se4. This is explained by the strong surface magnetic anisotropy which is essentially larger than the core anisotropy. Such a large coercivity is rare for materials without rare earth or noble metal elements, and the Fe3Se4-based compounds can be the low-cost, nontoxic alternative materials for advanced magnets. In addition, an unusual effect of "switching" of magnetization in a field of 10 kOe was found in the Fe3Se4 nanoparticles below 280 K, which can be important for applications.

[Morbidity and mortality rate from malignant neoplasms among Belgorod region population as a gerontological problem].

It is established during 1990-2008 new onset of morbidity level of adult people with malignant new growths by 21,2% (among men 16,9%; among women 25,2%). In Belgorod region for the studied period the average age of the population with morbidity has risen by 2,9 years from 37,1 to 40 (men from 33,7 to 37,3 years; women from 40 to 42,2 years).

[To the problem of organization in regions of rehabilitation of handicapped elders with gastroenterological diseases].

Authors have revealed that rehabilitation index in young and middle ages are higher, than in elders. Also the state of elder invalidis is rather stable and more severe. The reasons of such situation are discussed.

Phytoremediation of oil-sludge-contaminated soil.

The aim of this research was to select plant species that could be effective in the phytoremediation ofa former oil-sludge pit. Seven crop plants (Triticum aestivum L., Secale cereale L., Avena sativa L., Hordeum vulgare, Sorghum bicolor L Moench, Panicum miliaceum L, and Zea mays L.),five wild grasses (Lolium perenne L., Bromopsis inermis, Agropyron cristatum L., Agropyrum tenerum L., and Festuca pratensis Huds.), and three legumes (Medicago sativa L., Trifolium pratense L., and Onobrychis antasiatica Khin.) were screened for phytotoxicity, including the assessment of germination, shoot biomass, and root biomass, in a pot experiment. The estimation of oil-sludge degradation in the root zone of the tested plants showed that rye accelerated cleanup most effectively, degrading all of the main contaminant fractions in the oil sludge by a total of 52%. Although alfalfa had a lower phytoremediation potential than did rye, it maintained large numbers of soil microorganisms, including polycyclic aromatic hydrocarbon degraders, in its rhizosphere. Rye and alfalfa were chosen for a large-scale study to remediate an oil-sludge pit on the grounds of a petroleum refinery. Remediation monitoring confirmed the effectiveness of rye: the oil-sludge content decreased consistently for 3 years and remained low in comparison with the results from other plant species.

Magnetic order in FeCr(2)S(4)-type chalcogenide spinels.

The thiospinels of composition FeCr(2)S(4) and Fe(1+x)Cr(2-2x)Sn(x)S(4) with 0

[Strain of Pseudomonas aeruginosa--producer of bioPAV]. / Shtamm Pseudomonas aeruginosa--produtsent bioPAV.

A Pseudomonas aeruginosa strain producing an extracellular surfactant (biosurfactant) was isolated. The growth of this strain, referred to as 50.3, on a mineral glycerol-containing medium produces an emulsifying activity (60%) and decreases the surface tension of the culture liquid by a factor of 2.8 (to 25 mN/m). The optimum conditions for its growth and production of biosurfactants: intense aeration, pH 7.0-8.0, and the presence of Mg2+. The optimum biosurfactant properties were achieved when glucose was used as the only source of carbon and energy and NH4Cl was used as a source of nitrogen. The biosurfactant was isolated from the culture liquid by extraction and precipitation.