Rapid identification of Corynebacterium diphtheriae clonal group associated with diphtheria epidemic, Russian Federation.

We used 199 Corynebacterium diphtheriae isolated from 1995 to 1997 in Russia to evaluate the ability of random amplified polymorphic DNA (RAPD) to identify the unique clonal group that emerged there in 1990. Our data show that RAPD can reliably, reproducibly, and rapidly screen a large number of strains to identify the epidemic clonal group

Size fractionation of trace elements in the surface water and groundwater of the Ganjiang River and Xiushui River basins, China

The research of trace element behaviour and size fractionation is significant to understand the processes in the water-rock system. Moreover, the aqueous speciation of trace elements is strongly related to their distribution and toxicity. In this research, trace elements behaviour and their size fractionation are investigated in the natural water (the surface water and shallow groundwater) of the Ganjiang River and Xiushui River basins. Trace element concentrations were measured by ICP-MS. The authors estimated the size fractionation of the trace elements between suspended forms (>0.45 [mu]m) and dissolved fractions, which included truly dissolved (1 kDa) and colloidal particles (0.45 [mu]m-1 kDa)), after filtration through a 0.45 [mu]m acetate cellulose membrane filter. The distinct features of the trace element size fractionation were identified. The size fractionation of the trace elements under different conditions (in the surface water and shallow groundwater) was studied

National Report for the IAG of the IUGG 2019-2022

Major results of researches conducted by Russian geodesists in 2019-2022 on the topics of the International Association of Geodesy (IAG) of the International Union of Geodesy and Geophysics (IUGG) are presented in this issue. This report is prepared by the Section of Geodesy of the National Geophysical Committee of Russia. In the report prepared for the XXVII General Assembly of IUGG (Germany, Berlin, 11-20 July 2023), the results of principal researches in geodesy, geodynamics, gravimetry, in the studies of geodetic reference frame creation and development, Earth's shape and gravity field, Earth's rotation, geodetic theory, its application and some other directions are briefly described. For some objective reasons not all results obtained by Russian scientists on the field of geodesy are included in the report.Comment: Misprint in the title of the arXiv record has been corrected. The submission content is not affecte

On the issue of methods for determining silicon soluble compounds in water and the techniques of its desiliconization

The paper demonstrates the possibility to apply the methods of membrane and ion-exchange division to estimate a part of monomeric-dimeric, polymeric and anionic silicon forms. The authors have studied the influence of pH solution on quantitative ratio of silicon various forms. The subsequent water filtration through the membrane with pore diameter of 0,05 μm and then through the column with anion-exchange resin АV-17-8, ОН -f was proposed for desiliconization. It was ascertained that the method of atomic-absorption spectroscopy with electrothermal atomization is preferred to be used to determine the overall concentration of silicon soluble compounds in natural waters. The comparison of the analysis results by the methods of а atomic-absorption spectroscopy and spectrophotometry allows obtaining the information on the ratio of monomeric-dimeric and polymeric silicon forms

Structure and Electrochemical Properties of Porous Material Based on Aspen Wood

Исследованы структура и электрохимические свойства продуктов термохимического превращения опилок осины, модифицированных и немодифицированных хлоридом цинка. Показано, что добавка ZnCl2 в лигниноцеллюлозную массу приводит к существенному росту удельной поверхности карбонизованного продукта до 1800 м2.г-1 и образованию кристаллической фазы ZnO. С помощью циклической вольтамперометрии выявлено влияние условий синтеза материала и концентрации электролита (1М и 3М КОН) на форму вольтамперометрических кривых. Установлено, что древесина осины после длительной выдержки в воде может быть успешно использована для получения пористых углеродных электродных материаловThe structure and electrochemical properties of the products of the thermochemical transformation of aspen modifi ed and unmodifi ed with zinc chloride have been studied. It is shown that the addition of ZnCl2 to the lignin-cellulose mass leads to a signifi cant increase of the specifi c surface area of the carbonized product up to 1800 m2.g-1 and the formation of ZnO crystalline phase. The infl uence of the conditions of material synthesis and electrolyte concentration (1M and 3M KOH) on the shape of voltammetric curves is revealed by cyclic voltammetry. It is established that aspen wood after prolonged exposure in water can be successfully used to produce porous carbon electrode material