STABILITY OF NIOBIUM PENTACHLORIDE SOLUTIONS IN CHLORIDE MELTS

Dissolution of niobium pentachloride in molten alkali chlorides was studied in NaCl-KCl, NaCl-CsCl, NaCl-KCl-CsCl and LiCl-KCl based melts and the progress of the dissolution was followed by in situ spectroscopy measurements and oxidimetry. The obtained results indicate that NbCl6- species constituted the main product of this reaction. At relatively high niobium concentrations in the melt NbCl6-, however, partly decomposed yielding NbCl62- and chlorine gas. The influence of temperature and average radius of solvent cation on concentration of formed niobium (IV) species were investigated

INVESTIGATION OF THE PROCESESSES IN CONTACT OF NIOBIUM-CONTAINING CHLORIDE MELTS WITH NIOBIUM METAL

In the current study we found that upon contacting metallic niobium with a melt containing higher oxidation state niobium ions the average oxidation state of niobium in the salt phase, mass of the metal and potential difference between niobium and indicator electrodes decrease. After certain period of time these parameters tend to achieve certain constant values. This moment corresponds to the stationary state of the system. Analysis of the experimental data showed that the mixture of niobium (III) and (IV) ions is the final product of interaction of niobium-containing chloride melts with niobium metal and, therefore, a mixture of niobium ions in two oxidation states is present in equilibrium with the metal. The average oxidation state of niobium in the obtained melts (after contacting with Nb metal) increases with increasing niobium concentration. This observation correlates with the results of cathodic current efficiency measurements during niobium electrorefining. Thermodynamic calculations were performed using niobium red-ox and equilibrium electrode potentials in NaCl-KCl based melts at 700 0C. The results confirmed that equilibrium oxidation state of niobium in the fused chloride can increase with increasing total concentration of niobium in the melt

REACTION OF NIOBIUM-CONTAINING CHLORIDE MELTS WITH NIOBIUM METAL

In the current study, we found that upon contacting metallic niobium with a melt containing higher oxidation state niobium ions the average oxidation state of niobium in the salt phase, mass of the metal and potential difference between niobium and an indicator electrodes decrease. Analysis of the experimental data showed that the mixture of niobium (III) and (IV) ions is the final product of interaction of niobium-containing chloride melts with niobium metal and, therefore, a mixture of niobium ions in two oxidation states is present in equilibrium with the metal. The average oxidation state of niobium in the obtained melts (after contacting with Nb metal) increases with increasing niobium concentration. Thermodynamic calculations were performed using niobium red-ox and equilibrium electrode potentials in NaCl-KCl based melts at 700 0C. The results confirmed that equilibrium oxidation state of niobium in the fused chloride could increase with increasing total concentration of niobium in the melt

DEPENDING ELECTRODE POTENTIAL OF U-Pd ALLOYS IN 3LiCl–2KCl–UCl3 MELTS AT DIFFERENT TEMPERATURES

Electrode potential of U-Pd alloys in 3LiCl–2KCl–UCl3 melts were studied at different temperatures

The LabelHash algorithm for substructure matching

Background: There is an increasing number of proteins with known structure but unknown function. Determining their function would have a significant impact on understanding diseases and designing new therapeutics. However, experimental protein function determination is expensive and very time-consuming. Computational methods can facilitate function determination by identifying proteins that have high structural and chemical similarity. Results: We present LabelHash, a novel algorithm for matching substructural motifs to large collections of protein structures. The algorithm consists of two phases. In the first phase the proteins are preprocessed in a fashion that allows for instant lookup of partial matches to any motif. In the second phase, partial matches for a given motif are expanded to complete matches. The general applicability of the algorithm is demonstrated with three different case studies. First, we show that we can accurately identify members of the enolase superfamily with a single motif. Next, we demonstrate how LabelHash can complement SOIPPA, an algorithm for motif identification and pairwise substructure alignment. Finally, a large collection of Catalytic Site Atlas motifs is used to benchmark the performance of the algorithm. LabelHash runs very efficiently in parallel; matching a motif against all proteins in the 95 % sequence identity filtered non-redundant Protein Data Bank typically takes no more than a few minutes. The LabelHash algorithm is available through a web server and as a suite of standalone programs a

Temperature Dependence of the Potential U-Pd Alloys in 3LiCl-2KCl-UCl3 Melts

Temperature dependence of the potential U-Pd alloys in 3LiCl–2KCl–UCl3 melts were studied at different temperatures and concentrations using a variety of electrochemical techniques

SAMARIUM AND YTTERBIUM METAL PRODUCTION USING LANTANOTHERMIC REDUCTION

The method of lantanothermic reduction was proposed for production of metallic samarium and ytterbium. Their oxides were used as a crude material. The optimal conditions of the processes were determined. The enlarged lots of metals were produced using specially designed set-up

LANTANOTHERMIC METHOD OF SAMARIUM AND YTTERBIUM REDUCTION

The method of lantanothermic reduction was proposed for production of metallic samarium and ytterbium. Their oxides were used as a crude material. The optimal conditions of the processes were determined. The enlarged lots of metals were produced using specially designed set-up.The study was financially supported by the Ministry of Education and Science of the Russian Federation within the framework of subsidizing agreement of September 29, 2014 (no. 14.581.21.0002, unique agreement identifier RFMEFI58114X0002) of the Federal Target Program “Research and Development in Priority Directions of the Progress of the Scientific and Technological Complex of Russia for the Years 2014– 2020.

PRODUCTION OF METALLIC SAMARIUM AND YTTERBIUM BYLANTHANUM REDUCTION

The method of lantanothermic reduction was proposed for production of metallic samarium and ytterbium. Their oxides were used as a crude material. The optimal conditions of the processes were determined. The enlarged lots of metals were produced using specially designed set-up.The study was financially supported by the Ministry of Education and Science of the Russian Federation within the framework of subsidizing agreement of September 29, 2014 (no. 14.581.21.0002, unique agreement identifier RFMEFI58114X0002) of the Federal Target Program “Research and Development in Priority Directions of the Progress of the Scientific and Technological Complex of Russia for the Years 2014–2020.

Novel Wolbachia strains in Anopheles malaria vectors from Sub-Saharan Africa.

Background:  Wolbachia, a common insect endosymbiotic bacterium that can influence pathogen transmission and manipulate host reproduction, has historically been considered absent from the  Anopheles (An.) genera, but has recently been found in  An. gambiae s.l. populations in West Africa.  As there are numerous  Anopheles species that have the capacity to transmit malaria, we analysed a range of species across five malaria endemic countries to determine  Wolbachia prevalence rates, characterise novel  Wolbachia strains and determine any correlation between the presence of  Plasmodium,  Wolbachia and the competing bacterium  Asaia. Methods:  Anopheles adult mosquitoes were collected from five malaria-endemic countries: Guinea, Democratic Republic of the Congo (DRC), Ghana, Uganda and Madagascar, between 2013 and 2017.  Molecular analysis was undertaken using quantitative PCR, Sanger sequencing,  Wolbachia multilocus sequence typing (MLST) and high-throughput amplicon sequencing of the bacterial  16S rRNA gene.  Results: Novel  Wolbachia strains were discovered in five species:  An. coluzzii,  An. gambiae s.s.,  An. arabiensis,  An. moucheti and  An. species A, increasing the number of  Anopheles species known to be naturally infected. Variable prevalence rates in different locations were observed and novel strains were phylogenetically diverse, clustering with  Wolbachia supergroup B strains.  We also provide evidence for resident strain variants within  An. species A.  Wolbachia is the dominant member of the microbiome in  An. moucheti and  An. species A but present at lower densities in  An. coluzzii.  Interestingly, no evidence of  Wolbachia/Asaia co-infections was seen and  Asaia infection densities were shown to be variable and location dependent.  Conclusions: The important discovery of novel  Wolbachia strains in  Anopheles provides greater insight into the prevalence of resident  Wolbachia strains in diverse malaria vectors.  Novel  Wolbachia strains (particularly high-density strains) are ideal candidate strains for transinfection to create stable infections in other  Anopheles mosquito species, which could be used for population replacement or suppression control strategies