Methane hydrate emergence from Lake Baikal: direct observations, modelling, and hydrate footprints in seasonal ice cover.

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.

[Modern methods of diagnosis of chronic viral hepatitis used in the practice of the military-medical examination].

Modern methods of diagnosis of chronic viral hepatitis used in the practice of the military-medical examination. The article presents current views on the classification of chronic viral hepatitis. The characteristic of methodical diagnostic approaches is presented: The attention to the etiological pathology verification is paid. The results of study on clinical characteristics of patients with chronic viral hepatitis are used as the basis for the developed criteria for evaluating fitness for military service.

[The immunological and biochemical reactions of the cerebrospinal fluid in victims of blast injuries of the skull and brain]. / Immunologicheskie i biokhimicheskie reaktsii tserebrospinal'noi zhidkosti u postradavshikh s vzryvnymi porazheniiami cherepa i golovnogo mozga.

An analysis of immunobiochemical indices of the cerebrospinal fluid has shown possibilities to establish objective mechanisms of injuries of the brain by explosions. Biochemical manifestations of the cytolysis syndrome can be taken as symptoms of primary injury of the brain under conditions of burst polytrauma since increased activity of cytoplasmic and mitochondrial enzymes in the liquor is directly proportional to the brain trauma degree. The primary injury of the brain is characterized by a specific immune response: increased concentration of IgG, IgA in the liquor with the increased circulation of immune complexes.