[Frequency of drug resistance and immune escape mutations in the hepatitis B virus genome detected in pregnant women in the Republic of Guinea].

The aim of the work is to assess the prevalence of hepatitis B virus drug resistance mutations and immune escape mutations in pregnant women in the Republic of Guinea. MATERIALS AND METHODS: Blood plasma samples obtained from 480 pregnant women from different regions of the Republic of Guinea with laboratory-confirmed viral hepatitis B were studied. Nucleotide sequences for genotype identification and mutation detection were obtained using nested-PCR followed by Sanger sequencing, based on overlapping pairs of primers spanning the complete genome of the virus. RESULTS AND DISCUSSION: In the examined group, the viral genotype E was the most prevalent (92.92%) compared with subgenotypes A1 (1.67%), A3 (1.46%), D1 (0.63%), D2 (1.04%) and D3 (2.29%). Among the examined HBV-infected pregnant women, 188 (39.17%) had undetectable HBsAg. Drug resistance mutations were detected in 33 individuals, which amounted to 6.88%. The following mutations were found: S78T (27.27%), L80I (24.24%), S202I (15.15%), M204I/V (42.42%). The presence of polymorphic variants not described as drug resistant has also been shown in positions associated with the development of drug resistance to tenofovir, lamivudine, telbivudine and entecavir (L80F, S202I, M204R). When analyzing the MHR and the region of a determinant, mutations were detected in 318 (66.25%) of pregnant women. In 172 of them, which amounted to 54.09%, multiple mutations were found. The amino acid substitutions in 13 positions associated with HBsAg-negative hepatitis B and/or potentially affecting HBsAg antigenicity were identified. CONCLUSION: The high prevalence of immune escape and drug resistance mutations potentially associated with false-negative result of HBsAg screening, prophylaxis failure, and virological failure of therapy that has been identified among treatment naive pregnant women imposes a serious problem.

Bench tests of a helium ion source for the neutral particle diagnostic system of the ITER tokamak.

Bench tests of a 15 keV helium ion source, which has been developed for the neutral particle diagnostic system of the International Thermonuclear Experimental Reactor (ITER), are described. Being part of the diagnostic system, the ion source will be used to monitor the intactness of carbon stripping foils as well as to check the detection and dispersion systems of the main diagnostic instruments-neutral particle analyzers (NPAs). The ion source produces a wide 5-cm diameter (FWHM) ion beam at a distance of about 50 cm; the ion beam uniformity at a 2-cm area corresponding to the size of the stripping foil is not worse than 10%. The beam current over the area of the stripping foil can be adjusted in the range of 0.1 pA-1 pA. After initial heating, the temporal stability of the ion beam is better than 10%. Pulse height measurements of registered signals show that 15 keV He+ ions can be reliably registered by the NPA detector system. The obtained results allow us to conclude that the developed ion source can provide a reliable check of the NPA system during the diagnostic performance on the ITER tokamak.

Update of ion-optical system of neutral beam of Tokamak à Configuration Variable.

An injector of fast deuterium atoms for plasma heating was designed and installed at the Tokamak à Configuration Variable (TCV). The neutral beam can deliver 1 MW power to the plasma in 2 s pulses. An ion beam of the injector is formed by a triode multislit ion-optical system with spherical electrodes which provide ballistic focusing. Tests at TCV revealed that the total angular divergence of the neutral beam across the slits exceeded the expected value more than twice. It was finally established that this increase in divergence was caused by the asymmetry of the chamfers at the slit edges of the plasma electrode. The redesigned shape of the slits of the plasma grid together with precise machining significantly improved the beam quality. Experimental testing proved that the neutral beam profile in the direction across the grid slits became very close to the expected value.

THE IMPACT OF THE ACRYLIC MONOMER ON THE MORPHOLOGICAL STRUCTURE OF RAT LINGUAL MUCOSA.

The analysis of publications shows that diverse multiple factors can induce changes in taste sensitivity and the main irritants are the chemicals of different types. However, the study of the effect of the components of dental structural materials on the state of lingual mucosa, in particular, taste sensors, has not been fully elucidated to date. The purpose of the paper was the study of the effect of monomer of the "Ftoraks" base acrylic resin on the state of the rats' lingual mucosa within 2-4 weeks after its impact. The previous paper [5] presents the findings of the study on the impact of the monomer of the "Ftoraks" base acrylic resin on the state of the rats' lingual mucosa in the early period (1 to 7 days) and its subsequent regeneration. The studies have found that the greatest changes in the lingual mucosa occur on day 3 and 7 after the application of monomer, and are of erosive-inflammatory origin. Regeneration of the lingual epithelium is delayed. The studies confirm that the monomer of acrylic resin causes a number of pathological changes in the mucous membrane and muscles of the rat tongue, the nature of which varies depending on the duration of its impact. On day 14 in the lingual mucosa the destructive processes are significantly delayed, substituting for the sclerotic processes in the proper plate and atrophic processes, observed, first of all, in the papillae of the tongue. It is appropriate to assume that such changes in the papillae will lead to violation of the taste reception, first of all, in the areas of lateral surfaces of the body of the tongue and in the root area. At the same time, it should be noted that at the end of the experimental period (on day 28 of the contact of the monomer with the lingual mucosa), in the mucous membrane of the tongue, along with atrophic and sclerotic processes, the destructive changes and inflammatory reaction are evident. We hypothesize that this may indicate about partial recovery of taste sensitivity due to the decrease in the number of gustatory buds, taste papillae of different types and the increase in the period of their regeneration.

Note: Arc discharge plasma source with plane segmented LaB6 cathode.

A plane cathode composed of close-packed hexagonal LaB6 (lanthanum hexaboride) segments is described. The 6 cm diameter circular cathode is heated by radiation from a graphite foil flat spiral. The cathode along with a hollow copper anode is used for the arc discharge plasma production in a newly developed linear plasma device. A separately powered coil located around the anode is used to change the magnetic field strength and geometry in the anode region. Different discharge regimes were realized using this coil.

[MORPHOLOGICAL FEATURES OF RAT MUCOUS MEMBRANE OF THE TONGUE EARLY AFFECTED BY ACRYLIC RESIN MONOMER].

Base materials, made on the basis of various derivatives of acrylic and methacrylic acids, have been widely used in prosthetic dentistry. Free monomer, affecting the tissues of prosthetic bed and the whole body, is always found in dentures. Therefore, study of the effect of acrylic resins' monomer on mucous membrane of the tongue is crucial. Rat tongue is very similar to human tongue, and this fact has become the basis for selecting these animals to be involved into the experiment. The paper presents the findings related to the effect of "Ftoraks" base acrylic resin monomer on the state of rat mucous membrane of the tongue and its regeneration. The microscopy has found that the greatest changes in the mucous membrane of the tongue occur on day 3 and 7 day after applying the monomer and are of erosive and inflammatory nature. Regeneration of tongue epithelium slows down.

Multi-slit triode ion optical system with ballistic beam focusing.

Multi-slit triode ion-optical systems with spherical electrodes are of interest for formation of intense focused neutral beams for plasma heating. At present, two versions of focusing multi-slit triode ion optical system are developed. The first ion optical system forms the proton beam with 15 keV energy, 140 A current, and 30 ms duration. The second ion optical system is intended for heating neutral beam injector of Tokamak Configuration Variable (TCV). The injector produces focused deuterium neutral beam with 35 keV energy, 1 MW power, and 2 s duration. In the later case, the angular beam divergence of the neutral beam is 20-22 mrad in the direction across the slits of the ion optical system and 12 mrad in the direction along the slits.

APPLICATION OF GRAFTSKIN TO ACCELERATE HEALING OF ULCERS IN DIABETIC FOOT SYNDROME.

Diabetic foot syndrome (DFS) is one of the severe and more frequent complications of diabetes. It is characterized by occurrence of chronic purulent necrotic processes (trophic ulcers) on the foot with damage of skin, soft tissues and osteoarticular system due to pathological changes in the peripheral nervous system (diabetic neuropathy) and vascular system (diabetic angiopathy). This study aimed to evaluate the possibility of accelerating of wound healing in DFS by using the dermal equivalent (graftskin) and determine the safety of the method, factors and indications for its application. The research included 60 patients with DFS who were cured at the period from 2013 to 2016 in departments of purulent surgery of Hospital of war veterans and Municipal hospital № 14 of Saint-Petersburg. The patients were divided into 2 groups by random sampling of two comparable groups in age and sex. The patients of main group were treated by standard method and using application of dermal equivalent (DE) on the area of trophic ulcers. The patients of control group had only standard treatment. The DE showed a high efficacy in the main group of patients. The application of DE in complex treatment of patients with DFS stimulated processes of healing and accelerated the rate of epithelization. The application of DE was the most effective in patients with neuropathic form of DFS.

Low energy, high power hydrogen neutral beam for plasma heating.

A high power, relatively low energy neutral beam injector was developed to upgrade of the neutral beam system of the gas dynamic trap device and C2-U experiment. The ion source of the injector produces a proton beam with the particle energy of 15 keV, current of up to 175 A, and pulse duration of a few milliseconds. The plasma emitter of the ion source is produced by superimposing highly ionized plasma jets from an array of four arc-discharge plasma generators. A multipole magnetic field produced with permanent magnets at the periphery of the plasma box is used to increase the efficiency and improve the uniformity of the plasma emitter. Multi-slit grids with 48% transparency are fabricated from bronze plates, which are spherically shaped to provide geometrical beam focusing. The focal length of the Ion Optical System (IOS) is 3.5 m and the initial beam diameter is 34 cm. The IOS geometry and grid potentials were optimized numerically to ensure accurate beam formation. The measured angular divergences of the beam are ±0.01 rad parallel to the slits and ±0.03 rad in the transverse direction.

[Perfusion, Metabolism and Regional Myocardial Contractility in Patients With Valvular Heart Disease: a Long-Term Follow-Up After Valve Replacement].

AIM: To perform complex assessment of myocardial perfusion, metabolism, and regional contractility in patients with valvular heart disease (VHD) in remote period after surgical correction of heart defects. MATERIAL AND METHODS: We examined 30 patients with VHD in 1-8 years after heart valve replacement because of mitral (n=13) or aortic (n=17) valve defects of the following etiology: rheumatic heart disease (n=10), degeneration of connective tissue (n=13), infective endocarditis (n=7). For assessment of myocardial perfusion, metabolism, and regional contractility, we used single photon emission computed tomography (SPECT). RESULTS: Myocardium of patients who had undergone surgical correction of heart valve defects was characterized by dominating diffuse sclerotic changes localized mostly in basal segments. Hibernating myocardium was a less frequent finding. There were segments of borderline state with normal parameters of metabolism but slight impairment of perfusion without pronounced disturbances of kinetics. Patients with infectious etiology of valvular defects had combined perfusion and metabolic changes in multiple myocardial segments. Extensive derangements of perfusion and metabolism were characteristic for patients with connective tissue degeneration. CONCLUSION: Signs of cardiac failure caused by disturbances of myocardial perfusion and metabolism in patients with valvular heart disease can persist even after successful correction of valvular defect with normalization of intracardiac hemodynamics.

[ABCG1 transporter gene expression in peripheral blood mononuclear cells of patients with atherosclerosis].

Accumulation of cholesterol in arterial wall macrophages is a main hallmark of atherosclerosis. The ABCG1 transporter mediates cholesterol efflux to high density lipoproteins (HDL) and plays an important role in macrophage foam cell formation. The goal of our study was to investigate the potential role of ABCG1 in atherosclerosis development in humans. ABCG1 gene expression has been examined in leukocytes, monocytes and monocyte-derived macrophages of patients with atherosclerosis and in the control group. Real time PCR and Western blotting were used to determine ABCG1 mRNA and ABCG1 protein levels. Monocyte ABCG1 mRNA level was inversely correlated with the rate of artery occlusion (r = -0.45, P = 0.016). Patients with 100% artery occlusions had decreased monocyte ABCG1 mRNA levels compared to patients who had smaller plaques and controls (P < 0.05). ABCG1 mRNA (P < 0.001) and ABCG1 protein (P < 0.05) levels in macrophages of patients with coronary artery stenosis were significantly reduced compared to the control group. No significant correlation between the ABCG1 gene expression in mononuclear cells and HDL cholesterol concentration has been found. Our study suggests that decrease in the ABCG1 gene expression in macrophages is associated with atherosclerosis.

[Comparative analysis of the early postoperative period in patients with postoperative ventral hernias after different nonstrain hernioplastic techniques application].

The article presents the research of the early postoperative period in 64 patients with postoperative ventral hernias who underwent the operation by two different ways. The method of patch applied on the hernial orifice was used in 30 cases. In these cases prosthesis contacted with hypoderm. The modified way of Toskin-Zhebrovskiy was carried out in 34 patients. In these cases the prosthesis was isolated from hypoderm using the hernia bag flap. It was shown, that the frequency of seromas formation was significantly less in comparison with standard method of nonstrain hernioplasty in early postoperative period. Given method allowed shortening the terms of inpatient treatment on 3 days.

Production, formation, and transport of high-brightness atomic hydrogen beam studies for the relativistic heavy ion collider polarized source upgrade.

The RHIC polarized H(-) ion source had been successfully upgraded to higher intensity and polarization by using a very high brightness fast atomic beam source developed at BINP, Novosibirsk. In this source the proton beam is extracted by a four-grid multi-aperture ion optical system and neutralized in the H2 gas cell downstream from the grids. The proton beam is extracted from plasma emitter with a low transverse ion temperature of ∼0.2 eV which is formed by plasma jet expansion from the arc plasma generator. The multi-hole grids are spherically shaped to produce "geometrical" beam focusing. Proton beam formation and transport of atomic beam were experimentally studied at test bench.

Development of a negative ion-based neutral beam injector in Novosibirsk.

A 1000 keV, 5 MW, 1000 s neutral beam injector based on negative ions is being developed in the Budker Institute of Nuclear Physics, Novosibirsk in collaboration with Tri Alpha Energy, Inc. The innovative design of the injector features the spatially separated ion source and an electrostatic accelerator. Plasma or photon neutralizer and energy recuperation of the remaining ion species is employed in the injector to provide an overall energy efficiency of the system as high as 80%. A test stand for the beam acceleration is now under construction. A prototype of the negative ion beam source has been fabricated and installed at the test stand. The prototype ion source is designed to produce 120 keV, 1.5 A beam.

Arc plasma generator of atomic driver for steady-state negative ion source.

The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB6 cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode.

[Individual approach to choosing the exposure time during myocardial perfusion single-photon emission computed tomography].

OBJECTIVE: To assess whether the quality of the results of myocardial perfusion single-photon emission computed tomography (SPECT) may be improved by applying an individual approach to choosing the exposure time of a study. MATERIAL AND METHODS: The results of myocardial perfusion SPECT with the radiotracer (RT) Technetril upon 25-sec (short) and 60-sec (long) exposures in 22 patients with valvular heart disease (VHD) and coronary heart disease (CHD) were retrospectively analyzed. The basis for the comparative assessment of the study results was the number of myocardial impulses (NMI). The reference informative value was taken as a NMI equal to 21,000-77,000. All the patients were divided into two groups: 1) those with a NMI of below 21,000 and 2) those with a NMI of above 21,000. The raw counts of RT and lesion extent were compared in each group during two exposure modes. RESULTS: No statistically significant differences were found between the raw counts of RT in the left ventricular segments upon short and long exposure regardless of NMI. Evaluation of lesion extent revealed differences in sizes and/or location in 14 (63,6%) patient upon various exposures, most (10 patients) of them were from Group I and only 4 patients were from Group 2, these patients having marked myocardial hypertrophy. CONCLUSION: To enhance the informative value of myocardial perfusion SPECT, it is expedient to individually choose exposure time for each patient, being oriented to the time taken to achieve a NMI of at least 21,000, which can be determined by making one planar scintigram in the left anterior oblique projection (LAO 45 degrees).

[ABCA1 mRNA and protein levels in M-CSF-activated macrophages from patients with arterial stenosis].

ABCA1 transporter is one of the key factors defining the level of antiatherogenic HDL in plasma. It is actively involved in the removal of cholesterol from peripheral tissues by reverse cholesterol transport. However, the influence of the level of ABCA1 mRNA and the level of ABCA1 protein 1 in macrophages in atherosclerosis remains unexplored. Using real time PCR we determined ABCA1 mRNA level in macrophages cultured for 5 days with macrophage colony-stimulating factor (M-CSF). ABCA1 mRNA levels in macrophages from patients with arterial stenosis were increased when compared with the control group, P = 0.04. According to a Western blot analysis ABCA1 protein level in macrophages from patients was significantly lower than in the control group, P = 0.01. Our results suggest that the level of ABCA1 mRNA and level of ABCA1 protein in macrophages may be important factors in the development of atherosclerosis.

Commissioning of heating neutral beams for COMPASS-D tokamak.

Two neutral beam injectors have been developed for plasma heating on COMPASS-D tokamak (Institute of Plasma Physics, Prague). The 4-electrodes multihole ion-optical system with beam focusing was chosen to provide the low divergence 300 kW power in both deuterium and hydrogen atoms. The accelerating voltage is 40 kV at extracted ion current up to 15 A. The power supply system provides the continuous and modulated mode of the beam injection at a maximal pulse length 300 ms. The optimal arrangement of the cryopanels and the beam duct elements provides sufficiently short-length beamline which reduces the beam losses. The evolution of the impurities and molecular fraction content is studied in the process of the high voltage conditioning of the newly made ion sources. Two injectors of the same type have been successfully tested and are ready for operation at tokamak in IPP, Prague.

Use of the focusing multi-slit ion optical system at RUssian Diagnostic Injector (RUDI).

The upgrade of the diagnostic neutral beam injector RUDI in 2010 was performed to increase the beam density at the focal plane in accordance with the requirements of charge-exchange recombination spectroscopy diagnostics. A new focusing ion-optical system (IOS) with slit beamlets and an enlarged aperture was optimized for 50% higher nominal beam current and reduced angular divergence with respect to the previous multi-aperture IOS version. The upgraded injector provides the beam current up to 3 A, the measured beam divergence in the direction along the slits is 0.35°. Additionally, the plasma generator was modified to extend the beam pulse to 8 s.

BINP accelerator based epithermal neutron source.

Innovative facility for neutron capture therapy has been built at BINP. This facility is based on compact vacuum insulation tandem accelerator designed to produce proton current up to 10 mA. Epithermal neutrons are proposed to be generated by 1.915-2.5 MeV protons bombarding a lithium target using (7)Li(p,n)(7)Be threshold reaction. In the article, diagnostic techniques for proton beam and neutrons developed are described, results of experiments on proton beam transport and neutron generation are shown, discussed, and plans are presented.