Optically Triggered Néel Vector Manipulation of a Metallic Antiferromagnet MnAu under Strain.

The absence of stray fields, their insensitivity to external magnetic fields, and ultrafast dynamics make antiferromagnets promising candidates for active elements in spintronic devices. Here, we demonstrate manipulation of the Néel vector in the metallic collinear antiferromagnet MnAu by combining strain and femtosecond laser excitation. Applying tensile strain along either of the two in-plane easy axes and locally exciting the sample by a train of femtosecond pulses, we align the Néel vector along the direction controlled by the applied strain.

Dysfunction of Neuromuscular Synapses in the Genetic Model of Alzheimer's Disease.

The function of synaptic transmission and presynaptic vesicular cycle in the neuromuscular synapses of the diaphragm was studied in transgenic APP/PS1 mice (Alzheimer's disease model). The decrease in the quantal content of end-plate potential, intense depression of the amplitude of terminal plate potentials under conditions of lasting high frequency stimulation (50 Hz), a drastic prolongation of the synaptic vesicle recycling time in APP/PS1 mice in comparison with wild type mice were detected. Manifest dysfunction of the neuromuscular synapses, caused by disordered neurosecretion and recycling of the synaptic vesicles in the presynaptic nerve endings, was detected in the Alzheimer's disease model on transgenic APP/PS1 mice.

[The modular strategy for the informational support of medical activities based at the spa and health resort facilities under conditions of infrastructure deficit].

The Crimean peninsula, by virtue of its unique geographical conditions, has a variety of natural resources providing a basis for the maintenance of the health resort activities in the region. However, most local health centers suffer from the chronic and difficultly avoidable in the short term problems with logistical support, including the shortage of computers and the lack of modern network infrastructure. This circumstance limits the deployment capabilities of high-grade medical information systems for the automation of all components of the activity of health resorts and the significant improvement of the performance of other aspects of their work, such as efficient patient routing, workflow optimization, limiting the opportunities for the realization of certain corruption schemes by the staff.

[The development of the medical information system for the improvement of the quality of work of the Crimean spa and health resorts].

The Crimea has the enormous potential for the health promotion activities. However, neither the profile of these activities nor the demand for the socio-medical services is clearly defined for the majority of the local spa and health resort facilities. The possibilities of modern information technology are not used in the full measure either.

On the binding of nanometric hydrogen-helium clusters in tungsten.

In this work we developed an embedded atom method potential for large scale atomistic simulations in the ternary tungsten-hydrogen-helium (W-H-He) system, focusing on applications in the fusion research domain. Following available ab initio data, the potential reproduces key interactions between H, He and point defects in W and utilizes the most recent potential for matrix W. The potential is applied to assess the thermal stability of various H-He complexes of sizes too large for ab initio techniques.

Dislocation mechanism of deuterium retention in tungsten under plasma implantation.

We have developed a new theoretical model for deuterium (D) retention in tungsten-based alloys on the basis of its being trapped at dislocations and transported to the surface via the dislocation network with parameters determined by ab initio calculations. The model is used to explain experimentally observed trends of D retention under sub-threshold implantation, which does not produce stable lattice defects to act as traps for D in conventional models. Saturation of D retention with implantation dose and effects due to alloying of tungsten with, e.

[Study of the interaction of myoglobin with lipid bilayer membranes by potentiodynamic method].

For modeling the interaction of myoglobin with mitochondrial membranes, the adsorption of different ligand forms, the physiologically active reduced MbO2 and inactive oxidized met-Mb, on one of the surfaces of artificial bilayer lipid membrane (BLM) was studied using potentiodynamic technique known as the "capacity minimization" method. As mitochondrial membranes are negatively charged, BLM from the negatively charged palmitoyl-2-oleil-phosphatidyl glycerol (POPG) and neutral soybean phosphatidylcholine (lecithin) were used. It is shown that both myoglobins strongly interact with BLM in the pH range 6-8.

Sensitivity of intracellular calcium-binding sites for exo- and endocytosis of synaptic vesicles to Sr, Ba, and Mg ions.

Experiments on frog cutaneous-thoracic muscle preparations using electrophysiological (intra- and extracellular recording of postsynaptic signals) and optical (confocal microscopy with the fluorescent endocytic stain FM 1-43) methods were performed to study neurotransmitter secretion and the processes of exo- and endocytosis of synaptic vesicles in motor nerve endings on substitution of extracellular Ca ions with other alkaline earth metals (Sr, Ba, or Mg). Massive asynchronous exocytosis was induced by high-potassium solution, while synchronous exocytosis was induced by prolonged high-frequency stimulation of the motor nerve. The calcium-binding site for asynchronous exocytosis was found to be sensitive to Sr, Ba, and Mg ions, while the site for synchronous exocytosis was only sensitive to Sr ions.

Topography and affinity of calcium sensors of exo- and endocytosis in motor nerve terminals.

Measurements with extracellular microelectrode technique showed that depolarization of motor nerve terminals in frog cutaneous pectoris muscle with high-potassium solution (40 mM K(+)) increased frequency of miniature end-plate currents. Both fast intracellular calcium chelator BAPTA-AM and slow chelator EGTA-AM equally moderated the increase in the frequency of miniature end-plate currents. Intravital fluorescent microscopy with FM 1-43 dye showed that under conditions of stimulation of neurotransmitter exocytosis and secretion with high-potassium solution, internalization of the dye into newly-formed endocytotic synaptic vesicles proceeded both in the control and in the presence of EGTA-AM.

[Sensitivity of intracellular calcium-binding sites of exo- and endocytosis of synaptic vesicles to Sr, Ba and Mg ions].

In the experiments on frog motor nerve endings made with electrophysiological (intra- and extracellular recording ofpostsynaptic sygnals) and optical (confocal microscopy with usage of fluorescent marker FM 1-43) approaches, transmitter release and exo-endocytosis of synaptic vesicles after replacement ofextracellular Ca ions by other alkaline earth metal ions (Sr, Ba, Mg) were studied. Massive asynchronous exocytosis with high potassium solution and evoked exocytosis with high-frequency rhythmic stimulation of motor nerve were initiated. It has been shown that the site of asynchronous exocytosis was sensitive to Ca, Sr, Ba and Mg ions whereas the site of evoked (synchronous) exocytosis--to Ca and Sr ions only.

[Heliogeophysical risk factors of development of neural tube defects].

The data of the monitoring of the birth defects of the neural tube for 1985-2007 years from Crimean Republic Medical Genetic Center has been analyzed. The group of comparison: 127 cases of the neural tube defects The control group: 127 cases of birth of healthy children closest by the time and place of birth (for each case from comparison group). By the method of superposed epochs the weekly values of the heliogeophysical indices (Ap index of geomagnetic activity, Wolf Numbers--index of Solar activity, interplanetary magnetic field polarity) during the gametogenesis and embryo period of prenatal development The statistical significance of the values of heliogeophysical indices in the comparison and control groups was calculated using the statistical Wilcoxon criterion for the independent groups.

[Interaction of dopamine with artificial phospholipid membranes].

The interaction of dopamine (DA) with phospholipid membranes has been investigated. The membrane current in planar bilipid membrane (BLM) modified by amphotericin B in voltage clamp conditions under alternating polarity was shown to symmetrically increase 1.2 times when DA was added outside the BLM.

Effects of high-potassium solutions and caffeine on synaptic vesicle exoendocytosis processes in the frog neuromuscular junction.

Studies on frog skin-pectoris muscle preparations using vital fluorescent microscopy showed that stimulation of transmitter secretion using high-potassium solutions with the endocytosis marker FM 1-43 induced bright spots in all motor nerve terminals, these representing accumulations of vesicles undergoing the exoendocytic cycle in the active zones of nerve endings. Stimulation of transmitter secretion with caffeine evoked bright spots only in some nerve terminals and only in some parts of the terminals. In summer, the number of bright spots on stimulation of transmitter secretion by caffeine increased sharply.

[Effects of probiotic bifiform on efficacy of Helicobacter pylori infection treatment].

Aim: To study effects of the probiotic bifiform on efficacy of Helicobacter pylori (HP) eradication in patients with chronic gastritis and ulcer disease.

Material And Methods: A total of 98 patients with verified HP infection were divided into two groups. The study group received a week three-component anti-HP therapy+a probiotic.

[The intracellular calcium and mechanisms of endocytosis of synaptic vesicles at the frog nerve ending].

In the experiments on frog motor nerve endings of cutaneous pectoris muscle, made by extracellular recording of synaptic signals, it has been shown that the increase in intracellular calcium ion concentration in the nerve ending (by enhance of extracellular potassium ion concentration, or by addition of caffeine) leads to an increase in the miniature end-plate potential frequency, which is preserved over the whole period (about 10 min) of action of these substrates. The rhythmic stimulation of motor nerve (20 or 100 imp/s) quickly leads to a decrease in the end plate potentials amplitude. It has been shown by fluorescent microscopy with the use of endocytotic marker FM 1-43 that in the course of a short time exposition (5 min) in a high potassium solution (40 mM) or caffeine (5 mM), light spots appeared in the nerve ending.

[Effects of high potassium solutions and caffeine on the processes of exo-endocytosis of synaptic vesicles at the frog motor nerve ending].

In experiments on the frog motor nerve endings of cutaneous pectoris muscle using fluorescent microscopy it has been shown that initiation of massive transmitter release of synaptic vesicles by high potassium solutions in using endocytotic marker FM 1-43 at the nerve terminals light spots occurred only at some of the nerve terminals or at the some parts of nerve terminal. It has been revealed that application of caffeine increased the number of light terminals. Using extracellular microelectrode recording, we showed that both high potassium solutions and caffeine increased frequency of miniature end-plate potentials in a dose-dependent manner.

[Methods to optimize the management of Helicobacter pylori infection. The comparative efficacy of the triple and quadruple therapy used as a first line therapy].

The study involved a dynamic comparative efficacy survey of the standard triple and quadruple therapies recommended by the Maastricht Consensus as first line therapies for eradication of Helicobacter pylori infection with the time period of 5 years. The study included 199 Hp-positive patients with stomach ulcer; 101 of them were under examination in 1997 and 98 in 2002. Depending on the therapy type, patients were assigned to one of two groups: the OCM/A group (48 and 53 patients in 1997 and 2002, respectively) was treated with Omeprazole, Clarithromycin and Metronidazole for 7 days and ODTM group (46 and 52 patients in 1997 and 2002, correspondingly) was treated with Omeprazole, De-Nol, Tetracycline and Metronidazole.

Kiss-and-run quantal secretion in frog nerve-muscle synapse.

Electrophysiological and optical methods were used to study exo- and endocytosis of synaptic vesicles underlying secretion of the neurotransmitter from motor nerve terminals in frog sternocutaneous muscle. Increase in extracellular concentration of K+ or sucrose produced similar increase in the frequency of miniature endplate currents recorded by extracellular microelectrode. Fluorescent microscopy revealed bright spots in nerve terminal during stimulation of secretion with high-potassium solutions in the presence of endocytosis marker FM1-43.

[Analysis of living motor nerve ending of a frog by endocytotic fluorescent marker FM 1-43].

In our experiments on motor nerve endings of the frog cutaneous pectoris muscle, using fluorescent marker FM 1-43, the intensity and topography of endocytosis were investigated after the initiation of massive exocytosis of synaptic vesicles by increasing the extracellular potassium concentration. Using FM 1-43, fluorescent spots were shown to appear, looking as accumulations of synaptic vesicles in the active zone region. The forms and sizes of luminous spots and the distances between them were analysed.

[Current methods of ulcer therapy and their efficacy and cost].

The purpose of this study is to assess the efficiency of the anti-ulcer therapy taking into account the economic aspects of treatment. We have examined 708 HP-positive(+) patients with stomach ulcers (SU) and duodenal ulcers (DU). Various schemes of anti-helicobacter and anti-secretory therapy were administered to them.