Chemical reaction monitoring using zero-field nuclear magnetic resonance enables study of heterogeneous samples in metal containers

We demonstrate that heterogeneous/biphasic chemical reactions can be monitored with high spectroscopic resolution using zero-field nuclear magnetic resonance spectroscopy. This is possible because magnetic susceptibility broadening is negligible at ultralow magnetic fields. We show the two-step hydrogenation of dimethyl acetylenedicarboxylate with para-enriched hydrogen gas in conventional glass NMR tubes, as well as in a titanium tube. The low frequency zero-field NMR signals ensure that there is no significant signal attenuation arising from shielding by the electrically conductive sample container. This method paves the way for in situ monitoring of reactions in complex heterogeneous multiphase systems and in reactors made of conductive materials while maintaining resolution and chemical specificity

Spontaneous N-15 Nuclear Spin Hyperpolarization in Metal-Free Activation of Parahydrogen by Molecular Tweezers

The ability of frustrated Lewis pairs (FLPs) to activate H-2 is of significant interest for metal-free catalysis. The activation of H-2 is also the key element of parahydrogen-induced polarization (PHIP), one of the nuclear spin hyper polarization techniques. It is demonstrated that o-phenylene-based ansa-aminoboranes (AABs) can produce H-1 nuclear spin hyperpolarization through a reversible interaction with parahydrogen at ambient temperatures. Heteronuclei are useful in NMR and MRI as well because they have a broad chemical shift range and long relaxation times and may act as background-free labels. We report spontaneous formation of N-15 hyperpolarization of the N-H site for a family of AABs. The process is efficient at the high magnetic field of an NMR magnet (7 T), and it provides up to 350-fold N-15 signal enhancements. Different hyperpolarization effects are observed with various AAB structures and in a broad temperature range. Spontaneous hyperpolarization, albeit an order of magnitude weaker than that for N-15, was also observed for B-11 nuclei.Peer reviewe

Isolation of two strains of West Nile virus during an outbreak in southern Russia, 1999.

From July to September 1999, a widespread outbreak of meningoencephalitis associated with West Nile virus (Flavivirus, Flaviviridae) occurred in southern Russia, with hundreds of cases and dozens of deaths. Two strains of West Nile virus isolated from patient serum and brain-tissue samples reacted in hemagglutination-inhibition and neutralization tests with patients' convalescent-phase sera and immune ascites fluid from other strains of West Nile virus

Polyphenol oxidase from Pectobacterium atrosepticum: identification and cloning of gene and characteristics of the enzyme

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim In the present study, we attempted to elucidate if the harmful phytopathogenic bacteria of Pectobacterium genus (P. atrosepticum) possess the enzymes for oxidation of phenolic compounds. Polyphenol oxidase (laccase) activity was revealed in P. atrosepticum cell lysates. Using bioinformatic analysis, an ORF encoding a putative copper-containing polyphenol oxidase of 241 amino acids with a predicted molecular mass of 25.9 kDa was found. This protein (named Pal1) shares significant level of identity with laccases of a new type described for several bacterial species. Cloning and expression of the pal1 gene and the analysis of corresponding recombinant protein confirmed that Pal1 possessed laccase activity. The recombinant Pal1 protein was characterized in terms of substrate specificity, kinetic parameters, pH and temperature optimum, sensitivity to inhibitors and metal content. Pal1 demonstrated alkali- and thermo-tolerance. The kinetic parameters K m and kcat for 2,6-dimethoxyphenol were 0.353 ± 0.062 mM and 98.79 ± 4.9 s −1 , respectively. The protein displayed high tolerance to sodium azide, sodium fluoride, NaCl, SDS and cinnamic acid. The transcript level of the pal1 gene in P. atrosepticum was shown to be induced by plant-derived phenolic compound (ferulic acid) and copper sulfate

Low-valent homobimetallic Rh complexes: influence of ligands on the structure and the intramolecular reactivity of Rh–H intermediates

Supporting two metal binding sites by a tailored polydentate trop-based (trop - 5H-dibenzo[a,d] cyclohepten-5-yl) ligand yields highly unsymmetric homobimetallic rhodium(I) complexes. Their reaction with hydrogen rapidly forms Rh hydrides that undergo an intramolecular semihydrogenation of two C≡C bonds of the trop ligand. This reaction is chemoselective and converts C≡C bonds to a bridging carbene and an olefinic ligand in the first and the second semihydrogenation steps, respectively. Stabilization by a bridging diphosphine ligand allows characterization of a Rh hydride species by advanced NMR techniques and may provide insight into possible elementary steps of H₂ activation by interfacial sites of heterogeneous Rh/C catalysts

Results of the Test-Run of the Computer Software Model Support System for Managerial Decision Making

Considered is the experience of development of the decision support system (DSS) in the sphere of biological safety provision. Described are the objectives, functions, and architecture of DSS. Represented are the results of operational program-testing in the model territory (the Astrakhan region). Indicated is the effectiveness of DSS for information support of the control activity over internal and external biosafety hazards. Determined are the directions for further development of DSS

Provision of Epidemiological Welfare on Plague under Aggravation of Epizootic Situation in the Pre-Caspian Sandy Natural Plague Focus in 2014

Reviewed are the lessons learned from cooperation between Rospotrebnadzor institutions in the provision of epidemiological welfare on plague under aggravation of epizootic situation in the territory of the Pre-Caspian sandy natural plague focus in 2014. Plague control measures combined epizootiological and epidemiological monitoring, specific and non-specific prophylaxis, training activities for medical and veterinary officers, instructional advice for medical facilities on matters of infection prevention, and sensitization campaign. Furthermore, vaccinated against plague were 4460 people, field disinsection over 50.5 km2 area was performed, as well as field deratization - 89.4 km2, township disinsection - 257.3 thous. m2, and township deratization - 329.1 thous. m2. Financial expenses on prophylactic (anti-epidemic) activities amounted to 23265.8 thousand rubles. Outlined was viability of preventive planning and prophylactic measures in the territories with forecasted aggravation of epizootic situation in natural plague foci of the Russian Federation

INHERITANCE OF BASIC QUANTITATIVE TRAITS BY THE HYBRIDS OF GRAIN SORGHUM OF THE FIRST GENERATION

In the work with all crops including sorghum, it’s necessary to know the character of the inheritance of basic economic traits so that to decrease the time for breeding of new varieties and hybrids. While studying the hybrids of the first generation the specialist can precisely reveal a recessive or a dominant effect of the gene, which controls this or that trait. The article gives the results of study of the inheritance of plant height, length of peduncle and mass of 1000 seeds characteristic to the hybrids of grain sorghum of the first generation. ‘Plant height’ is an important trait in grain sorghum breeding which largely determines resistance of a variety or a hybrid to lodging and suitability to machine harvesting. Analyzing 21 hybrids of the first generation on the trait ‘plant height’ 80,9% of them revealed presumptive heterosis and 66,7% showed authentic heterosis.  The hybrids with authentic heterosis possessed overdominance (hp>1,0) of the trait. ‘Length of peduncle’ is of great importance for grain sorghum breeding and determines its suitability for machine harvesting. The most hybrids (14) revealed their overdominance according to the trait ‘extension of a panicle’. ‘Mass of 1000 seeds’ is one of the basic elements of grain sorghum productivity, which determines grain size and maturity. The studied hybrids of the first generation showed different types of the trait inheritance, such as a depression, a partial and a full dominance of both a little and a large value of the trait, and an overdominance as well