Trends of the major porin gene (ompF) evolution

OmpF is one of the major general porins of Enterobacteriaceae that belongs to the first line of bacterial defense and interactions with the biotic as well as abiotic environments. Porins are surface exposed and their structures strongly reflect the history of multiple interactions with the environmental challenges. Unfortunately, little is known on diversity of porin genes of Enterobacteriaceae and the genus Yersinia especially. We analyzed the sequences of the ompF gene from 73 Yersinia strains covering 14 known species. The phylogenetic analysis placed most of the Yersinia strains in the same line assigned by 16S rDNA-gyrB tree. Very high congruence in the tree topologies was observed for Y. enterocolitica, Y. kristensenii, Y. ruckeri, indicating that intragenic recombination in these species had no effect on the ompF gene. A significant level of intra- and interspecies recombination was found for Y. aleksiciae, Y. intermedia and Y. mollaretii. Our analysis shows that the ompF gene of Yersinia has evolved with nonrandom mutational rate under purifying selection. However, several surface loops in the OmpF porin contain positively selected sites, which very likely reflect adaptive diversification Yersinia to their ecological niches. To our knowledge, this is a first investigation of diversity of the porin gene covering the whole genus of the family Enterobacteriaceae. This study demonstrates that recombination and positive selection both contribute to evolution of ompF, but the relative contribution of these evolutionary forces are different among Yersinia species

Relationships between piezoelectric and energy-harvesting characteristics of 1–2–2 composites based on domain-engineered single crystals

The paper reports on the piezoelectric performance, electromechanical coupling and related energy-harvesting figures of merit of three forms of 1–2–2 composites based on domain-engineered single crystals. The effect of the single-crystal piezoelectric properties and elastic properties of the laminar polymer matrix on the appropriate figures of merit of the composite is studied. The main active components of the studied composites are [0 0 1]-poled perovskite-type single crystals with chemical compositions: 0.92Pb(Zn1/3Nb2/3)O3–0.08PbTiO3, 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3 and [Li x (K1−y Na y)1−x ](Nb1−z Ta z)O3: Mn, where x = 0.06, y = 0.1–0.3, z = 0.07–0.17, and the level of Mn doping is 0.25 mol. %. Examples of non-monotonic volume-fraction dependences of the piezoelectric properties, figures of merit and anisotropy factors are analysed. New diagrams are first built to demonstrate the volume-fraction regions where a large anisotropy of the piezoelectric coefficients d 3j * and electromechanical coupling factors k 3j * is achieved, and where energy-harvesting figures of merit of the composite are at least five times larger than analogous parameters of single-crystal components. The studied 1–2–2 composites are of interest as anisotropic materials with high piezoelectric sensitivity and large figures of merit which are important for sensor, energy-harvesting and related applications.</p

Hourly average values of solar wing parameters (flow rate and ion temperatures) according to data of measurements of the Venera-9 and Venera-10 automatic interplanetary stations on an Earth-Venus during the period June 1975 - April 1976

Four electrostatic analyzers with channel electron multipliers as detectors were used to measure solar wind ionic flow. The axes of the fields of vision of two of these analyzers were directed along the axis of the automatic interplanetary station, oriented towards the Sun, while the other two were turned in one plane at angles of +15 deg and -15 deg. The full hemisphere of the angular diagram of each analyzer was approximately 5 deg. The energetic resolution was approximately 6%, and the geometric energy was 0.002 sq cm ave. keV. Each analyzer covered an energetic range of approximately 10 in eight energetic intervals. Spectral distributions were processed in order to obtain the velocity and temperature of the protons. Tabular data show the hour interval (universal time) and the average solar wind velocity in kilometers per second

Oxidation of 2-carene by means of potassium permanganate

The oxidation of 2-carene with KMnO4 leads to the formation of 2 α,3 α-caranediol and 3 α-hydroxy-2-caranone. The reduction of the latter with KBH4 gives 2 β, 3 α-caranediol. © 1975 Plenum Publishing Corporation

Frequency of Interferon-Resistance Conferring Substitutions in Amino Acid Positions 70 and 91 of Core Protein of the Russian HCV 1b Isolates Analyzed in the T-Cell Epitopic Context

Funding Information: This study was supported by the grant of the Russian Science Foundation (Project ID 15-15-30039). Mobility and training of the researchers was supported by the grants of the Swedish Institute (TP 09272/2013 and PI 19806/2016). Publisher Copyright: © 2018 V. S. Kichatova et al.Amino acid substitutions R70Q/H and L91M in HCV subtype 1b core protein can affect the response to interferon and are associated with the development of hepatocellular carcinoma. We found that the rate of R70Q/H in HCV 1b from Russia was 31.2%, similar to that in HCV strains from Asia (34.0%), higher than that in the European (18.0%, p=0.0010), but lower than that in the US HCV 1b strains (62.8%, p<0.0001). Substitution L91M was found in 80.4% of the Russian HCV 1b isolates, higher than in Asian isolates (43.8%, p<0.0001). Thus, a significant proportion of Russian HCV 1b isolates carry the unfavorable R70Q/H and/or L91M substitution. In silico analysis of the epitopic structure of the regions of substitutions revealed that both harbor clusters of T-cell epitopes. Peptides encompassing these regions were predicted to bind to a panel of HLA class I molecules, with substitutions impairing peptide recognition by HLA I molecules of the alleles prevalent in Russia. This indicates that HCV 1b with R70Q/H and L91M substitutions may have evolved as the immune escape variants. Impairment of T-cell recognition may play a part in the negative effect of these substitutions on the response to IFN treatment.Peer reviewe

Oxidation of carene by thallium(III) acetate

2-p-Tolylpropanol-2, p-menth-1,8-dien-3-ol, p-menth-1-en-3α, 8-diol, p-menth-1-en-3β, 8-diol, p-menth-1-en-3-on-8-ol, p-menth-1,8-dien-5,6-diol, and 2,3-dihydroxy-1,8-cineole are formed during the oxidation of 2-carene by thallium (III) acetate. © 1984 Plenum Publishing Corporation