Delocalized nonlinear vibrational modes and discrete breathers in ß-FPUT simple cubic lattice.

The problem of finding various discrete breathers (DBs) in the ß-Fermi-Pasta-Ulam-Tsingou simple cubic lattice is addressed. DBs are obtained by imposing localizing functions on delocalized nonlinear vibrational modes (DNVMs) having frequencies above the phonon spectrum of the lattice. Among 27 DNVMs with the wave vector at the boundary of the first Brillouin zone there are three satisfying this condition. Seven robust DBs of different symmetries are found using this approach.

[PERSONAL GROWTH AND PERCEIVED ABILITY TO WORK OF HEADS OF DEPARTMENTS OF MEDICAL ORGANIZATIONS].

INTRODUCTION: Despite the need for the heads of departments to implement the labor functions of a clinician and manager, the study of personal growth and perceived ability to work in this category of medical workers was not carried out. THE PURPOSE OF THE STUDY: determining the relationship of personal growth and perceived ability to work of heads of departments of medical organizations, as well as the impact on self-esteem of various characteristics of this category of respondents. METHODS: A correspondence survey was conducted of 216 heads of clinical departments in the section «personal growth¼ of the questionnaire «psychological well-being of Riff¼ and the questionnaire «perceived ability to work¼ of the Institute of Social Research of the University of Michigan. The personal growth index is the average score according to the statements of the 1st questionnaire. The index of ability to work is the sum of points for each of the statements of the 2nd questionnaire. The average length of service is 23.1 ± 8.60 years, the average age is 47.9 ± 8.08 years. 123 (56.9%) men, 117 (54.2%) worked in a hospital, 114 (52.8%) worked in the «red zone¼, 111 (51.4%) have a second higher education, 138 (63.89%) have a qualification category, 63 (29.1%) have an academic degree. The Spearman correlation coefficients and the Student's criterion are calculated to assess the relationship and significance of differences between indices and characteristics. RESULTS: The personal growth index is 4.89 ± 0.818, the work ability index is 33.60 ± 4.564 points. Respondents aged 41-50 have significantly (p < 0.001) lower indices. There was no significant difference between the index of personal growth and the index of ability to work in respondents of different sexes (р = 0.864 and р = 0.951), those who worked in inpatient and outpatient settings (р = 0.834 and р = 0.848); those who worked in the «red zone¼ (р = 0.727 and р = 0.775), respondents with a qualification category (р = 0.543 and р = 0.404), with an academic degree (р = 0.871 and р = 0.898), with the second highest education (р = 0.443 and р = 0.588). There is an average direct correlation of personal growth indices and perceived ability to work (r = 0.6; p < 0.001). CONCLUSION: The relationship between personal growth indices and perceived ability to work, significantly lower indices in the group of 41-50 years and over 60 years must be taken into account to ensure the professional development of department heads.

Development of a PCR assay for the detection of human herpes virus type 7.

A PCR assay has been developed to identify the DNA of the human herpes virus type 7. The search and selection of conserved regions was carried out by comparing the whole genome nucleotide sequences of HHV-7. A fragment duplicated in the HHV-7 genomes was chosen as a target for amplification. The performance of the assay was tested on a synthetic matrix and clinical samples. The developed assay has high sensitivity and specificity and showed good efficiency in detecting HHV-7 DNA in clinical samples.

Reconstruction of the Rat Sciatic Nerve by Using Biodegradable and Non-Biodegradable Conduits.

The aim of the study was to compare two types of conduits made of either non-resorbable Reperen or resorbable Tissucol for their effects on the regeneration of the rat sciatic nerve under conditions of stump diastasis. MATERIALS AND METHODS: The experiments were carried out using outbred white male rats of the reproductive age (n=14). The animals were divided into three groups: group 1, intact (n=5), used for studying the morphology of the sciatic nerve; group 2 (n=4) - nerve plastic surgery was performed using a conduit made of non-resorbable Reperen; group 3 (n=5) - surgery was performed using a conduit made of resorbable Tissucol. The animals were anesthetized with isoflurane. After a complete transection of the sciatic nerve in the middle third of the thigh, its stumps were inserted into a conduit of an internal diameter of 2 mm and a length of 10 mm, filled with saline. Diastasis of 5 mm in length was created by spreading the nerve ends and securing the epineurium to the tube edges with 8/0 polypropylene sutures. A total count of myelinated nerve fibers was performed in the area of repair (tubulation) and the distal part of the nerve; the formation of connective tissue sheaths was assessed 14 weeks after the operation. RESULTS: According to the morphological assessment, both types of conduits (resorbable and non-resorbable) caused the similar number of fibers to restore in the distal part of the repaired nerve; clinical characteristics of the animals in both groups were close to each other and to the norm. CONCLUSION: The results allow us to consider the conduit made of non-resorbable Reperen as a device promising for neuroplasty along with the resorbable conduit made of Tissucol.

Distinction between electron states formed at topological insulator interfaces with the trivial phase and vacuum.

In this paper, we show that electron states formed in topological insulators at the interfaces topological phase-trivial phase and topological phase-vacuum may possess different properties. This is demonstrated on an example of heterostructures based on thick topological Hg1-xCdxTe films, in which the PT-symmetric terahertz photoconductivity is observed. It is shown that the effect originates from features of the interface topological film-trivial buffer/cap layer. The PT-symmetric terahertz photoconductivity is not provided by electron states formed at the interface topological film-vacuum.

Non-local terahertz photoconductivity in the topological phase of Hg1-xCdxTe.

We report on observation of strong non-local photoconducitivity induced by terahertz laser pulses in non-zero magnetic field in heterostructures based on Hg1-xCdxTe films being in the topological phase. While the zero-field non-local photoconductivity is negligible, it is strongly enhanced in magnetic fields ~ 0.05 T resulting in appearance of an edge photocurrent that exceeds the respective dark signal by orders of magnitude. This photocurrent is chiral, and the chirality changes every time the magnetic field or the electric bias is reversed. Appearance of the non-local terahertz photoconductivity is attributed to features of the interface between the topological film and the trivial buffer.

[Rational treatment of patients with functional dyspepsia].

Functional dyspepsia is one of the most common functional disorders of the gastrointestinal tract, which resulted from impaired motor skills, visceral hypersensitivity, increased mucosal permeability, disorders of the autonomic nervous system, etc. There is no specific therapy for this disease, which often leads to the irrational use of various groups of drugs. Drug therapy is recommended only during periods of symptoms. The main options of pharmacotherapy include the use of proton pump inhibitors, phytotherapeutic drugs, eradication therapy of Helicobacter pylori. Against the background of possible motor disorders, prokinetics are also one of the possible treatment options, but cisapride has long been withdrawn from sale due to cardiotoxicity, the use of domperidone and metoclopramide is limited due to side effects, especially with long-term therapy, so currently the only prokinetic that can be used in everyday clinical practice is itopride. In refractory cases, tricyclic antidepressants and psychotherapeutic approaches are another effective treatment option.

Scenarios of hyperchaos occurrence in 4D Rössler system.

The generalized four-dimensional Rössler system is studied. Main bifurcation scenarios leading to a hyperchaos are described phenomenologically and their implementation in the model is demonstrated. In particular, we show that the formation of hyperchaotic invariant sets is related mainly to cascades (finite or infinite) of nondegenerate bifurcations of two types: period-doubling bifurcations of saddle cycles with a one-dimensional unstable invariant manifold and Neimark-Sacker bifurcations of stable cycles. The onset of the discrete hyperchaotic Shilnikov attractors containing a saddle-focus cycle with a two-dimensional unstable invariant manifold is confirmed numerically in a Poincaré map of the model. A new phenomenon, "jump of hyperchaoticity," when the attractor under consideration becomes hyperchaotic due to the boundary crisis of some other attractor, is discovered.

Broad-beam plasma-cathode electron beam source based on a cathodic arc for beam generation over a wide pulse-width range.

We describe the design, parameters, and characteristics of a modified wide-aperture, plasma-cathode electron beam source operating in the pressure range of 3 Pa-30 Pa and generating large-radius, low-energy (up to 10 keV) electron beams with a pulse width varying from 0.05 ms to 20 ms and a beam current up to several tens of amperes. A pulsed cathodic arc is used to generate the emission plasma, and a DC accelerating voltage is used to form the electron beam. Modernization of the design and optimization of the operating conditions of the electron source have provided a multiple increase in the pulse duration of the electron beam current and the corresponding increase in the beam energy per pulse, as compared to previously developed pulsed forevacuum electron sources.

Ion transport across solid-state ion channels perturbed by directed strain.

We combine quantum-chemical calculations and molecular dynamics simulations to consider aqueous ion flow across non-axisymmetric nanopores in monolayer graphene and MoS2. When the pore-containing membrane is subject to uniaxial tensile strains applied in various directions, the corresponding permeability exhibits considerable directional dependence. This anisotropy is shown to arise from directed perturbations of the local electrostatics by the corresponding pore deformation, as enabled by the pore edge geometries and atomic compositions. By considering nanopores with ionic permeability that depends on the strain direction, we present model systems that may yield a detailed understanding of the structure-function relationship in solid-state and biological ion channels. Specifically, the observed anisotropic effects potentially enable the use of permeation measurements across strained membranes to obtain directional profiles of ion-pore energetics as contributed by groups of atoms or even individual atoms at the pore edge. The resulting insight may facilitate the development of subnanoscale pores with novel functionalities arising from locally asymmetric pore edge features.

Apparent PT-symmetric terahertz photoconductivity in the topological phase of Hg1-xCdxTe-based structures.

We show that the terahertz (THz) photoconductivity in the topological phase of Hg1-xCdxTe-based structures exhibits the apparent PT- (parity-time) symmetry whereas the P-symmetry and the T-symmetry, separately, are not conserved. Moreover, it is demonstrated that the P- and T-symmetry breaking may not be related to any type of the sample anisotropy. This result contradicts the apparent symmetry arguments and means that there exists an external factor that interacts with the sample electronic system and breaks the symmetry. We show that deviations from the ideal experimental geometry may not be such a factor.

The binding of monomeric amyloid ß peptide to serum albumin is affected by major plasma unsaturated fatty acids.

Human serum albumin (HSA) serves as a natural depot of amyloid ß peptide (Aß). Improvement of Aß binding to HSA should impede Alzheimer's disease (AD). We developed a method for quantitation of the interaction between monomeric Aß40/42 and HSA using surface plasmon resonance spectroscopy. The dissociation constant of HSA complex with recombinant Aß40/42 is 0.2-0.3 µM. Flemish variant of Aß40 has 2.5-10-fold higher affinity to HSA. The parameters of the HSA-Aß interaction are selectively sensitive to HSA binding of major plasma unsaturated fatty acids and Cu2+. Linoleic and arachidonic acids promote the HSA-Aß42 interaction. The developed methodology for quantitation of HSA-Aß interaction may serve as a tool for search of compounds favoring HSA-Aß interaction, thereby preventing AD progression.

A new family of transcriptional regulators of tungstoenzymes and molybdate/tungstate transport.

Bacterial genes for molybdenum-containing and tungsten-containing enzymes are often differentially regulated depending on the metal availability in the environment. Here, we describe a new family of transcription factors with an unusual DNA-binding domain related to excisionases of bacteriophages. These transcription factors are associated with genes for various molybdate and tungstate-specific transporting systems as well as molybdo/tungsto-enzymes in a wide range of bacterial genomes. We used a combination of computational and experimental techniques to study a member of the TF family, named TaoR (for tungsten-containing aldehyde oxidoreductase regulator). In Desulfovibrio vulgaris Hildenborough, a model bacterium for sulfate reduction studies, TaoR activates expression of aldehyde oxidoreductase aor and represses tungsten-specific ABC-type transporter tupABC genes under tungsten-replete conditions. TaoR binding sites at aor promoter were identified by electrophoretic mobility shift assay and DNase I footprinting. We also reconstructed TaoR regulons in 45 Deltaproteobacteria by comparative genomics approach and predicted target genes for TaoR family members in other Proteobacteria and Firmicutes.

INTERCHANGEABILITY OF VIRAL VACCINES FOR IMMUNIZATION.

The review presents the results of the analysis of domestic and foreign scientific literature on the interchangeability of hepatitis A, B and influenza vaccines. The WHO materials, regulatory documents, data from scientific literature of foreign countries and Russia about the vaccine interchangeability are summarized. The problem of objective assessment of interchangeability of drugs is relevant worldwide. The definition of an "interchangeable drug" does not draw a clear line between the interoperability criteria for chemical and immunobiological drugs. The official guidance documents on immunization adopted in several countries define "interchangeability" as the practice of transition from a vaccine available from a certain manufacturer to a similar vaccine available from another manufacturer. The term "interchangeable" can be applied to immunobiological drugs if one of the drugs can be replaced with the other in the course of vaccination. The concept of interchangeability applies to vaccines that do not differ in efficacy (immunological, preventive, epidemiological) and safety and are used in an immunization course involving multiple administration of these vaccines. The definition of interchangeability is important in order to address the problem of replacing unidirectional vaccines available from different manufacturers when purchasing vaccines included in the national schedule of preventive vaccinations and in the schedule of preventive vaccination on epidemic indications. One of the most important conditions for "interchangeability" of vaccines is their application in accordance with the recommended schedule of administration and the dosage indicated by the manufacturer. Research data show that vaccines can be interchangeable if used in accordance with the recommended schedule of administration and the dosage specified by the manufacturer. Control agencies of many countries issue recommendations regulating the procedure of vaccine replacement in case of necessity. However, there are no special regulations of vaccine interchangeability in Russia. The concept of vaccine "interchangeability" should be extended to the continuation of a course of vaccinations in a particular person with a vaccine of another manufacturer and the possibility of applying similar vaccines available from different manufacturers.

Potential of a superconducting photon counter for heterodyne detection at the telecommunication wavelength.

Here, we report on the successful operation of a NbN thin film superconducting nanowire single-photon detector (SNSPD) in a coherent mode (as a mixer) at the telecommunication wavelength of 1550 nm. Providing the local oscillator power of the order of a few picowatts, we were practically able to reach the quantum noise limited sensitivity. The intermediate frequency gain bandwidth (also referred to as response or conversion bandwidth) was limited by the spectral band of a single-photon response pulse of the detector, which is proportional to the detector size. We observed a gain bandwidth of 65 MHz and 140 MHz for 7 × 7 µm2 and 3 × 3 µm2 devices, respectively. A tiny amount of the required local oscillator power and wide gain and noise bandwidths, along with unnecessary low noise amplification, make this technology prominent for various applications, with the possibility for future development of a photon counting heterodyne-born large-scale array.

[COMPARATIVE EVALUATION OF THE TRANSGENE EXPRESSION EFFICIENCY PROVIDED BY THE MODEL GENETIC CONSTRUCTS OF DIFFERENT STRUCTURE.]

Comparative evaluation of the transgene expression efficiency provided by the model genetic constructs of different structure is an important stage in the development of new expression methods and optimization of the existing expression vectors. However, presently there is no versatile approach to this problem. The goal of this work was to suggest an experimental system for comparative evaluation of the expression efficiency provided by nonviral genetic vectors of various size and topology in human cell cultures. Such system is based on the gene of the green fluorescence protein used as a reporter as well as flow cytofluorometry for evaluation of the expression level and quantitative PCR for adequate selection of the transfection conditions. This system was tested in two model constructs: linear molecule of DNA and plasmid.

Adenosine A1 receptor activation attenuates cardiac hypertrophy and fibrosis in response to α1 -adrenoceptor stimulation in vivo.

BACKGROUND AND PURPOSE: Adenosine has been proposed to exert anti-hypertrophic effects. However, the precise regulation and the role of the different adenosine receptor subtypes in the heart and their effects on hypertrophic signalling are largely unknown. We aimed to characterize expression and function of adenosine A1 receptors following hypertrophic stimulation in vitro and in vivo. EXPERIMENTAL APPROACH: Pro-hypertrophic stimuli and adenosine A1 receptor stimulation of neonatal rat cardiomyocytes and male C57/Bl6 mice, sc. drug administration, real-time PCR, (3) [H]-leucine-incorporation assay, immunostaining, tissue staining, Western blots, gravimetric analyses and echocardiography were applied in this study. KEY RESULTS: In neonatal rat cardiomyocyte cultures, phenylephrine, but not angiotensin II or insulin-like growth factor 1 (IGF1), up-regulated adenosine A1 receptors concentration-dependently. The hypertrophic phenotype (cardiomyocyte size, sarcomeric organization, total protein synthesis, c-fos expression) mediated by phenylephrine (10 µM), but not that by angiotensinII (1 µM) or IGF1 (20 ng·mL(-1) ), was counteracted by the selective A1 receptor agonist, N6-cyclopentyladenosine. In C57/BL6 mice, continuous N6-cyclopentyladenosine infusion (2 mg·kg(-1) ·day(-1) ; 21 days) blunted phenylephrine (120 mg·kg(-1) ·day(-1) ; 21 days) induced hypertrophy (heart weight, cardiomyocyte size and fetal genes), fibrosis, MMP 2 up-regulation and generation of oxidative stress - all hallmarks of maladaptive remodelling. Concurrently, phenylephrine administration increased expression of adenosine A1 receptors. CONCLUSIONS AND IMPLICATIONS: We have presented evidence for a negative feedback mechanism attenuating pathological myocardial hypertrophy following α1 -adrenoceptor stimulation. Our results suggest adenosine A1 receptors as potential targets for therapeutic strategies to prevent transition from compensated myocardial hypertrophy to decompensated heart failure due to chronic cardiac pressure overload.

[Anesthetic management of robot-assisted radical prostatectomy].

The authors have an experience in performing of 700 radical prostatectomies by using of daVinci-robot. The main factors determining parameters of operation and anesthesia are presented in the article. The authors give recommendations for optimization of anesthetic management. The main features of patient preparation for robot-assisted radical prostatectomy, parameters of anesthesia and postoperative management of patients are presented in the article.

[Choosing the method of reconstruction for lower-limb critical ischemia].

Presented herein are long-term outcomes of surgical treatment of 74 patients with atherosclerotic occlusive-stenotic lesions of the femoral-popliteal-tibial segment and critical ischaemia. 51 (68.92%) patients underwent femoropopliteal shunting into the isolated segment of the reversed great saphenous vein. Of these, three patients were subjected to a hybrid operation consisting of femoropopliteal bypass grafting and balloon angioplasty of the popliteal and one tibial artery. 23 (31.08%) patients endured percutaneous balloon angioplasty with stenting of the superficial femoral artery and balloon angioplasty of one tibial artery. Two-year patency of the zone of reconstruction of the femoropopliteal segment in these groups was identical, amounting to 64.71 and 56.52%, respectively. However, the group of patients with endovascular intervention demonstrated rather a high rate of intraoperative complications--21.74%, technical success in balloon angioplasty of arteries of the crus amounted to 65.22%. Once the method of operative treatment is chosen, preference is given to shunting in the isolated popliteal artery with sufficient collateral blood flow. Further studies are required to determine angiographic indications for endovascular intervention on tibial arteries.