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

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