Acoustic Features of the Impact of Laser Pulses on Metal-Ceramic Carbide Alloy Surface.

Technologies associated with using concentrated energy flows are increasingly used in industry due to the need to manufacture products made of hard alloys and other difficult-to-process materials. This work is devoted to expanding knowledge about the processes accompanying the impact of laser pulses on material surfaces. The features of these processes are reflected in the acoustic emission signals, the parameters of which were used as a tool for understanding the accompanying phenomena.

Display of WEDM Quality Indicators of Heat-Resistant Alloy Processing in Acoustic Emission Parameters.

The widespread nature of heat-resistant alloys is associated with the difficulties in their mechanical machining. It forces the use of the wire electrical discharge machining to be wider. The productivity, roughness, and dimensions of the modified layer of the machined surfaces are indicators of the machining quality.

A strain-induced exciton transition energy shift in CdSe nanoplatelets: the impact of an organic ligand shell.

We study the influence of surface passivating ligands on the optical and structural properties of zinc blende CdSe nanoplatelets. Ligand exchange of native oleic acid with aliphatic thiol or phosphonic acid on the surface of nanoplatelets results in a large shift of exciton transition energy for up to 240 meV. Ligand exchange also leads to structural changes (strain) in the nanoplatelet's core analysed by wide-angle X-ray diffraction.

Raman effect in icosahedral boron-rich solids.

We present Raman spectra of numerous icosahedral boron-rich solids having the structure of α-rhombohedral, β-rhombohedral, α-tetragonal, β-tetragonal, YB, orthorhombic or amorphous boron. The spectra were newly measured and, in some cases, compared with reported data and discussed. We emphasize the importance of a high signal-to-noise ratio in the Raman spectra for detecting weak effects evoked by the modification of compounds, accommodation of interstitial atoms and other structural defects.

[Effects of antiorthostatic hypokinesia on blood levels of interleukine-1beta and interleukine-6 in primates].

Investigations with Macaca mulatta of 4-5 yrs. of age with the body mass of 4.5-6.

[Ultrastructural changes in the right atrium in rats during E. coli lipopolysaccharide-induced systemic inflammation].

In acute experiments on rats, systemic inflammation was induced by intraperitoneal E. coli lipopolysaccharide (LPS) injection that in a dose of 5 microg/kg caused an increase in rectal temperature by 1.0 +/- 0.

[Nitric oxide (NO) and NO cycle in myocardium: molecular, biochemical and physiological aspects].

The article continues the series of our publications on the problem of nitric oxide (NO) and its cyclic conversion in mammals. This review is held to analysis of nitric oxide role in regulation of cardiovascular system and in alocation of NO-synthases in myocardium. Molecular, biochemical and cytophysiological aspects that linked, with spatial localization of NO-synthases and mechanisms of NO content regulation in myocardium are considered.

Catalytic activity of gold nanoparticles incorporated into modified zeolites.

Gold catalysts modified by Fe and Ni and supported on different zeolite matrixes have been studied by TEM, TPR, and catalytic testing. The presence of a metal oxide additive allows stabilizing small gold particles, particularly in the case of Fe. The shape of light-off curves shows two temperature regions of the catalyst activity, a low-temperature range below 250 degrees C and a high-temperature range above 300 degrees C.

Symmetry-adapted-cluster configuration interaction study of the doublet states of HCl+: potential energy curves, dipole moments, and transition dipole moments.

The electronic structure of the HCl(+) molecular ion has been calculated using the general-R symmetry-adapted-cluster configuration interaction (SAC-CI) method. The authors present the potential energy curves, dipole moments, and transition dipole moments for a series of doublet states. The data are compared with the previous CASSCF and MCSCF calculations.

[Changes in the ultrastructure of histohematic barrier in the rat right atrium after short-term and prolonged heat stress].

In experiments on rats, changes of the ultrastructure of myocardial histo-hematic barriers in the right atrium during short-term and prolonged heat stress were studied. Short-term heat exposure (40 degrees C, 30 and 60 min) increased the rectal temperature by 3.0-3.

[Structural and functional changes in the right atrium of the rats induced by short- and long-term heat stress].

In acute experiments performed on rats placed in heat-chamber (40 degrees C, 30- and 60-minutes-long exposure), an increase in NADPH-diaphorase (NADPH-d) and succinate dehydrogenase (SDH) activities were found in the neurons of intramural ganglia of the right atrium, while SDH and lactate dehydrogenase (LDH) activities were increased in cardiomyocytes. Hormone-producing cardiomyocytes, containing atrial natriuretic peptide, had numerous large secretory granules under the sarcolemma close to the microvessels. In contractile cardiomyocytes, the signs of early stage of apoptosis were observed including the subsarcolemmal accumulation of small mitochondria and cytoplasmic invaginations into the nucleus.

Changes in the activity of NO synthase, energy metabolism enzymes, and the ultrastructure of cerebral cortical neurons in a model of transient ischemia.

Experiments were performed on white male Wistar rats under Nembutal-urethane anesthesia. Transient ischemia (10 min) was produced by clamping of the carotid arteries. Some neurons in the parietal area of the cerebral cortex and endotheliocytes in blood vessels showed increases in NO synthesis and in the activity of energy metabolism enzymes (SDH, LDH).

The effects of activation and blockade of central P2X receptors on body temperature.

The aim of the present work was to identify the role of ATP acting on specific P2X receptors in the central mechanisms of thermoregulation. Immunohistochemical studies demonstrated that brainstem structures involved in controlling body temperature contained large number of nerve cells bearing P2X ATP receptors. Experiments on conscious rats involving intracerebroventricular administration of an ATP analog and P2X antagonists showed that both activation and blockade of central P2X receptors produced marked changes in body temperature.

[Changes in the activity of NO-synthase, energy metabolism enzymes and ultrastructure in neurons of the cerebral cortex in the model of short-term ischemia].

Experiments were performed on male Wistar rats under nembutal-urethan anesthesia. Short-time (10 min) cerebral ischemia was induced by bilateral ligation of carotid arteries. This was followed by an increased synthesis of NO and activity of energy metabolism enzymes (SDH, LDH) in a part of neurons of the parietal cortex and in endotheliocytes of blood vessels.

[Effect of activation and blockade of central P2X receptors on body temperature].

The aim of the present study was to elucidate the role of extracellular ATP acting on specific P2X receptors in the central mechanisms of thermoregulation. Using immunohistochemistry methods, it was found that the brainstem structures involved in the body temperature regulation contain a large number of nerve cells which possess P2X receptors for ATP. Experiments with intracerebroventricular application of a stable ATP analogue and P2X receptor antagonists to conscious rats showed that both activation and blockade of central P2X receptors resulted in marked changes in body temperature.

[Changes in the afferent activity of the vagus nerve and the rectal temperature in rats following Escherichia coli endotoxin administration].

In anaesthetised rats, i.p. administration of the Echerichia coli lipopolysaccharide in doses 5 mcg/kg (LPS) increased afferent activity of the cervical vagus, whereas 100 and 1000 mcg/kg doses inhibited the afferent discharges.

[Nitrogen monoxide in the mechanisms of cardiovascular functional resistance to emotional stress].

The paper presents the results of examination of the mechanisms of development of different physiological dysfunctions (diminished cardiac electrical stability, fibrillation threshold fall) under emotional stress. Search was made for their drug correction (nitric oxide precursor L-arginine, the NO synthase blocker Ng-methyl-L-arginine and sodium nitrate). Experiments have indicated that L-arginine and sodium nitrate restore cardiac electrical stability.

[Morphofunctional mechanisms of responses of sympathetic ganglia to the high external temperature and pyrogen exposure].

Reactive changes of structural and functional organization of pre- and paravertebral sympathetic ganglia were studied in experimental fever and under the effect of high temperatures using electron microscopy and histochemical methods. Changes in histochemical and ultramicroscopic characteristics of neuroglial complex, synaptic apparatus and of histohematic barrier were demonstrated. Correlation between those changes and the dose and duration of the challenge was established.

[Role of proteinase inhibitors in the process that provide coupling between body's functional systems].

The authors make an attempt to substantiate the idea that proteinase inhibitors can produce a noticeable effect on the integration of functions. It is suggested that proteinase inhibitors play a special role in providing coupling between the body's functional systems in the conditions that may disturb the structural and functional integrity of the organism. They paper provides experimental evidence for the effect of the serine proteinase inhibitor alpha 1-antitrypsin on the thermal regulatory system and couples functional systems that provide behavioral responses.

[Structural changes in the pelvic plexus in cold stress].

Alterations caused by hypothermal stress in neurons of pelvic plexus in rats were studied histochemically. The increase of catecholamine content in neurons and serotonin--in small intensely fluorescent cells (SIFC), suppression of acetyl cholinesterase activity in neurons were demonstrated after the short-term hypothermal stress leading to moderate hypothermia. Cooling of rats following the preliminary section of pelvic nerves does not prevent the above mentioned changes in neurons and SIFC.