High efficiency radio frequency pulse generation in a nonlinear corrugated coaxial transmission line with ferrite saturated by permanent magnets.

The work on the development of a generator of high-power, high-frequency pulses based on a nonlinear transmission line with saturated ferrite is presented. A feature of the generator is that the ferrite rings are saturated in the field of permanent magnets, unlike traditional generators with a solenoid wrapped around the transmission line. Due to the changed structure of the inner conductor, which is a corrugated conductor, the line has spatial dispersion. The paper demonstrates the generation of high-frequency pulses with a duration of up to 6 ns and a center frequency of 2.7 GHz. This pulse duration with a frequency above 2 GHz was not previously observed in traditional nonlinear transmission line geometry. The maximal peak power achieved was 70 MW for an incident voltage pulse of 90 kV. The energy efficiency of video pulse energy conversion into radio pulse was 6% [G. Kataev, Electromagnetic Shock Waves (Sov. Radio, Moscow, 1963)]. The paper discusses the performance of RF and microwave NiZn ferrites for the purposes of radio pulse generation.

[Assessment of cognitive and motor functions in older age groups: clinical significance, diagnostic tools, promising directions.]

Assessment of cognitive and motor function in older age groups is carried out to identify neurological deficits, clinical and functional prognosis, determination of rehabilitation potential, organization of accessible environment, prevention of progression of geriatric syndromes. The development of an applied methodology aimed at assessing both cognitive and motor functions, as well as cognitive-motor interaction in aging in normal and pathological conditions, is at the initial stage of formation. This article presents an overview of the methods used to assess cognitive and motor functions in clinical practice, analyzes the possibilities of their use for older age groups, and considers promising areas.

[Possibilities of estimation postural function in normal and pathological conditions: focus on age-related aspects.]

Age-associated disorders of the function of maintaining balance lead to an increase in the frequency of falls and related complications (injuries, limited mobility, decreased independence and autonomy, etc.). In addition, motor disorders of various genesis in most cases are accompanied by changes in postural function. An analytical review of the literature over the last decade devoted to methods of assessing postural balance in older age groups has been conducted. Computer stabilometry is recognized as the best method for an objective assessment of postural function and dynamic monitoring of the effectiveness of therapy. At the same time, the stabilometric characteristics of postural disorders in older age groups and the relationship between the indicators of stabilography and age remain insufficiently studied.

[Prevention of falls syndrome (analitic review).]

Falls in people over 60 years of age is usually interpreted as geriatric syndrome, which is one of the leading problems in geriatrics due to complications. In recent years, the frequency of falls has increased., Every third person faces a fall in old age, and every second person falls in the age over 85 years. Only a multifactorial and personalized approach to each patient will be able to reduce the risk of falling due to the peculiarities of this category of patients and the multidirectional genesis of the fall syndrome. The decision on the choice of tactics should be made by a group of specialists, and the assessment of the effectiveness of the measures used should be carried out in dynamics with due adjustment if necessary.

[Clinical and socially significant consequences of falls in elderly and senile persons (analytical review).]

Falls refers to geriatric syndromes, which is accompanied by a significant number of adverse clinically and socially consequences. For the rational organization of medical, social, psychological and other types of assistance and rehabilitation measures, separate groups of consequences developing as a result of a fall are distinguished: physical, functional, psychological, social. Every year, every fourth elderly and older person faces a fall, while about half of the victims seek medical help. Among people of older age groups who have suffered a fall episode, 20-30% have complications in the form of injuries, which further increase the risk of premature death. With two or more falls per year, the risk of complications increases significantly. This requires a comprehensive assessment of risk factors in each individual case.

[ANALYSIS OF POPULATION IMMUNITYAGAINST INFLUENZA PRIOR TO 2014 AND 2015 EPIDEMIC SEASONS].

AIM: Control for the population herd immunity against seasonal influenza viruses as well as for emergence of antibodies against influenza with pandemic potential in human blood sera. MATERIALS AND METHODS: HAI reaction against vaccine and epidemic influenza viruses as well as HPAI viruses A/rook/Chany/32/2015 (H5N1) (clade 2.3.2. lc.) andA/Anhui/01/2013 (H7N9). RESULTS: Among all the sera samples collected in the autumn of 2014 and 2015, none had reacted in HAI against A(H5N 1) and A(H7N9) antigens even at 1:10 dilution. Among samples collected in autumn 2014, 41% were positive to A/California/07/09(H1Nlpdm9) virus, 36% - A/Texas/50/2012 (H3N2), 40% - B/Brisbane/60/2008 (Vict.lin.) and 47% reacted in HAI against the B/Massachusetts/2/2012 (Yam.lin.) strain. 22% of all the samples had a titer of at least 40 against all the antigens and only 10% in HAI had a titer of 40 or more against all the vaccine strains. Among the samples collected in autumn 2015, the number of seropositive against A/California/07/09(HlNlpdmO9) varied from 31% in the Urals FD to 46% in the Southern FD. The amount of seropositive against A/Switzerland/9715293/13 (H3N2) strain was at the level of 4 - 13% in all the FDs except Urals, where this parameter was slightly above 30%. The amount of seropositive against vaccine influenza B viruses varied from 23 to 76%. Only 2% of sera had titers in HAI of 40 or above against all the vaccine strains, 29% of all the samples were seronegative. CONCLUSION: Population immunity in Russia against influenza A(H3N2) is at a very low level, thus socially significant consequences of influenza epidemics in many aspects will depend on the vaccination campaign of autumn 2016.

Quantum translator-rotator: inelastic neutron scattering of dihydrogen molecules trapped inside anisotropic fullerene cages.

We report an inelastic neutron scattering investigation of the quantum dynamics of hydrogen molecules trapped inside anisotropic fullerene cages. Transitions among the manifold of quantized rotational and translational states are directly observed. The spectra recorded as a function of energy and momentum transfer are interpreted in terms of the rotational potential and the cage dimensions. The thermodynamics of orthohydrogen and parahydrogen are investigated through temperature dependence measurements.

Solid-state NMR spectroscopy using the lost I spin magnetization in polarization transfer experiments.

A variation of the cross polarization (CP) experiment is discussed. The method requires two scans where the difference signal is equivalent to the I spin magnetization that is transferred to the S spins. The acquired signal is equivalent to F1 sum projection of a two-dimensional (2D) heteronuclear correlation experiment and is obtained by just two scans without the need to increment the indirect time domain t(1). Any polarization transfer method and any kind of spin manipulations during the t(1) incrementation period of a 2D NMR experiment can be applied. The method allows fast measurements of the CP transfer, particularly if various S spins signal overlap and is good for spectral editing of I spin signals with contact to S spins. Various examples for biomaterials are presented. Most importantly, this novel approach is ideal for detailed investigations of organic-mineral interfaces in bone, here demonstrated for O-phospho-l-serine as simple model compound.

Investigations of the active site of Saccharomyces cerevisiae dolichyl-phosphate-mannose synthase using fluorescent labeled dolichyl-phosphate derivatives.

Dolichol-phosphate mannose (Dol-P-Man) is a key mannosyl donor for the biosynthesis of N-linked oligosaccharides as well as for O-linked oligosaccharides on yeast glycoproteins, and for the synthesis of the glycosyl-phosphatidylinositol anchor found on many cell surface glycoproteins. It is synthesized by Dol-P-Man synthase which is the only glycosyltransferase in the dolichol pathway that has been expressed as an active protein, solubilized and purified in large enough quantities for structural investigations. Earlier studies showed that the enzyme is closely associated with membranes of endoplasmic reticulum with unique lipid requirements for its maximal activity. This potential target of antibiotic therapy is now being investigated at the molecular level to establish information about the structure of the enzyme as well as determine the nature and properties of the enzyme-phospholipid interactions. In this paper, we have determined the activities of the fluorescent labeled dolichyl-phosphate derivatives as well as the intramolecular distances between amino acid residues near the active site and/or the fluorophores of the substrate derivatives using fluorescence energy resonance transfer. These results also show that the conserved consensus sequence is not required by Dol-P-Man synthase neither for the recognition of Dol-P nor for the catalytic activity.

Synthesis of dolichyl phosphate derivatives with fluorescent label at the omega-end of the chain, new tools to study protein glycosylation.

Derivatives of dolichyl phosphate (Dol-P) with 2-aminopyridine or 1-aminonaphtalene fluorophore groups at the omega-end of the chain were synthesized. These products serve as substrates for recombinant yeast Dol-P-mannose synthase. Fluorescence resonance energy transfer between a Trp residue of the enzyme and the 1-aminonaphtalene group of the Dol-P analogue was demonstrated.

Dolichyl sulphate and H-phosphonate: enzymatic reactions with activated sugars.

Two phosphate-modified analogues of dolichyl phosphate were evaluated as substrates or inhibitors of the reactions catalyzed by mammalian microsomal enzymes. Dolichyl H-phosphonate could serve as an efficient acceptor for mannosyl and glucosyl transfer. The reaction products were chromatographically different from those formed from dolichyl phosphate. Lower activity of the H-phosphonate was observed for the reaction of N-acetylglucosaminyl phosphate transfer from UDP-GlcNAc. Dolichyl sulphate was shown not to serve as a substrate for the transfer of mannosyl (from GDP-Man), glucosyl (from UDP-Glc) or N-acetylglucosaminyl phosphate (from UDP-GlcNAc) residues in the presence of rat liver microsomes. Weak inhibitory properties of this analogue were demonstrated.

Phosprenyl: a novel drug with antiviral and immunomodulatory activity.

A novel antiviral drug with immunomodulatory activity (Phosprenyl) is presented. The main active ingredient of the preparation is polyprenyl phosphates. This medicine is highly efficient against a number of viruses, including HIV in vitro, and tick-borne encephalitis and rabies viruses in the experimental models in vivo. In veterinary practice Phosprenyl is now regarded as an effective therapeutic means for treatment of canine distemper, hepatitis, enteritis, etc.

Polyprenyl phosphates: synthesis and structure-activity relationship for a biosynthetic system of Salmonella anatum O-specific polysaccharide.

A series of polyprenyl phosphates with modified structure of polyprenyl residue was prepared through phosphorylation of polyprenyl trichloroacetimidates with phosphoric acid. Interaction of polyprenols with tetra-n-butylammonium dihydrogen phosphate and trichloroacetonitrile was found to represent a very efficient, simple and general method for the synthesis of polyprenyl phosphates. A procedure was developed for smooth conversion of polyprenyl pyrophosphates into the monophosphates through hydrolysis in the presence of 4-dimethylaminopyridine. The polyprenyl phosphates prepared were studied as substrates for the enzymes of Salmonella anatum O-specific polysaccharide biosynthesis. Correct stereochemistry of alpha- and beta-isoprenic units was found to be essential for substrate efficiency. At the more remote positions of the hydrocarbon chain just the presence of isoprenic units of any configuration seems necessary. Some changes in position of the phosphate group may be permissible without significant loss of substrate properties.