ABSTRACT
This paper provides a novel report of methane hydrates rising from bottom sediments to the surface of Lake Baikal, validated by photo and video records. The ascent of hydrates in the water column was confirmed by hydroacoustic data showing rising objects with velocities significantly exceeding the typical speeds (18-25 cm s-1) of gas bubbles. Mathematical modelling along with velocity and depth estimates of the presumed methane hydrates coincided with values observed from echograms. Modelling results also showed that a methane hydrate fragment with initial radius of 2.5 cm or greater could reach the surface of Lake Baikal given summer water column temperature conditions. Results further show that while methane bubbles released from the deep sedimentary reservoir would dissolve in the Lake Baikal water column, transport in hydrate form is not only viable but may represent a previously overlooked source of surface methane with subsequent emissions to the atmosphere. Methane hydrates captured within the ice cover may also cause the formation of unique ice structures and morphologies observed around Lake Baikal. Sampling of these ice structures detected methane content that exceeded concentrations measured in surrounding ice and from the atmosphere demonstrating a link with the methane transport processes described here.
ABSTRACT
Unambiguous identification of polyoxometalate (POM) species generated in self-assembly reactions in solution is rather problematic due to close similarity of their properties such as solubility and spectral characteristics. The situation is made more complex by protonation equilibria (which can change their analytical signals) and the lack of individual compounds to serve as standards for individual members of these mixtures. In the present work a new approach to the study of such POMs has been suggested, taking molybdovanadates [PMo12-xVxO40]-3-x as a model. The key feature of this approach consists of generation of so-called "conditional model systems" that include most of the expected components of a mixture formed by self-assembly, tracked down by reliable detection techniques, e.g., 51V NMR-spectroscopy in this particular case. Then the proposed composition of the mixture is verified and corrected by means of high-performance liquid chromatography coupled with inductively coupled plasma atomic emission spectrometry (HPLC-ICP-AES).
ABSTRACT
Medical support of the Petsamo-Kirkenes Offensive. W consider the organizational aspects of the healthcare support of Petsamo-Kirkenes Offensive in the Arctic. The conditions and factors that influenced the preparation and conduct of operations are analysed. It is shown that success and effectiveness of medical support of the operation are based on good planning, build-up of forces and means of medical service and manoeuvre, timely evacuation of the wounded and sick, experience of interaction and mutual reinforcement of the Army Medical Services, and the fleet can be used in the development of plans for medical support of diverse groups of troops (forces) in the Far North of Russia.
Subject(s)
Delivery of Health Care , Military Medicine , Military Personnel/history , War-Related Injuries/therapy , World War II , Delivery of Health Care/history , Delivery of Health Care/organization & administration , Delivery of Health Care/standards , Female , History, 20th Century , Humans , Male , Military Medicine/history , Military Medicine/organization & administration , Military Medicine/standardsABSTRACT
Reaction of [(C6H6)RuCl2]2 and Na8[Ta6O19] gives two new hybrid organometallic POM complexes, Na10[{(C6H6)RuTa6O18}2(µ-O)]·39.4H2O (Na10-1) and Na4(trans-[{(C6H6)Ru}2Ta6O19]·20H2O (Na4-2). In both cases the half-sandwich fragments {(C6H6)Ru}(2+) are coordinated as additional vertices to the {Ta3(µ2-O)3} triangles of the hexatantalate. According to NMR and ESI-MS data, the dimeric complex [{(C6H6)RuTa6O18}2(µ-O)](10-) dissociates in water with the formation of monomeric [(C6H6)RuTa6O19](6-) species (1a). X-ray structural characterization and aqueous speciation of the complexes by (13)C, (1)H, and DOSY NMR; ESI-MS; and capillary electrophoresis (CE) have been carried out.
ABSTRACT
The vertical distribution of microorganisms during spring deep-water renewal in Lake Baikal was studied. The downward advection of trophogenic waters was found to create conditions for the extensive growth of microorganisms capable of decomposing and mineralizing organic carbon, nitrogen, and phosphorus in deep water layers. These processes occur annually at spring thermal bars near the underwater slope of Lake Baikal, whereas in its pelagic zone, the deep intrusions of waters rich in organic material are observed only in the years when enhanced deep-water renewal is accompanied by a high spring yield of phytoplankton.
Subject(s)
Bacteria , Water Microbiology , Fresh Water , Phytoplankton , SiberiaABSTRACT
On the basis of the analysis of the results of treatment of 125 patients of the surgical profile, who were at critical state because of acute renal and hepatic failure, the high cost effectiveness of the extracorporeal methods of detoxication is shown.
Subject(s)
Acute Kidney Injury/therapy , Hemoperfusion/economics , Liver Diseases/therapy , Renal Dialysis/economics , Surgical Procedures, Operative/adverse effects , Acute Kidney Injury/etiology , Adult , Cost-Benefit Analysis , Female , Humans , Liver Diseases/etiology , Male , Middle AgedABSTRACT
A semi-empirical approach has been used to estimate the intramolecular electrostatic interactions in pepsin and penicillopepsin. The pH-dependence of the free energy electrostatic term was calculated, and the pH-dependence of the domain interactions has been estimated. As it was shown, the contribution of electrostatic interactions is rather small for the stabilization of the native structure. At the same time the electrostatic repulsion between domains increases with the increase of pH. The later can be the cause of the alkaline denaturation of pepsin and domain mobility.
