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The dynamics of the segment characteristics of alpha-rhythm and their correlation with the «behaviour» of dipole sources of alpha-band in relation to beta-stimulating neurofeedback in schoolchildren with ADHD syndrome were analyzed. Effective training results in forming of neuronal groups in alpha-band which correlate to the new dipole sources. Possible place of alpha-generating system in the mechanisms of effective neurobiofeedback is discussed.

The article is devoted to the pathogenesis, diagnosis, and prediction of postpartum thyroiditis

A method is proposed for measuring the low-frequency resistance fluctuations of the quasi-neutral region of bipolar transistors and the noise properties of KT3102 transistors are investigated.

With the use of thermovision set TVT-01 "Raduga" 17 healthy persons (control group) and 40 injured persons with the burn of various degree of severity were examined. In superficial I-II degree burn on the hand the temperature within the centre of injury exceeds normal level by 1.6-2 degrees C, and III A degree--by 2.2-2.6 degrees C. The healing of the burn wound was followed by gradual fall of her temperature, although she normalizes after epithelialization completion. In III B degree burn on the hand the temperature within the centre of injury decreases by 1.6-2.0 degrees C in comparison with the normal level. Autodermoplasty is effective only in the presence of temperature gradient between transplant zone and healthy tissues no more than 1.5 degrees C.

The results of simultaneous investigations of noise characteristics and contact resistance of different contacts to low-resistivity ( ρ b = 1–10 ohm cm) ZnS single crystals including so-called ohmic contacts with a contact resistance ρ c = 0.1–0.5 ohm cm 2 are described and analyzed. A conclusion is drawn that the difficulties in obtaining ohmic contacts to low-resistivity ZnS are connected with the presence on the semiconductor contact surface of acceptor centers filled by electrons which are responsible for the increase of band bending at the semiconductor surface. In the case of ohmic contacts the contact barrier is lowered significantly owing to formation of the ionized donor centers in the contact region; electrons penetrate such barriers by tunneling.

1. Analysis of interconnection between unit activity in the visual, parietal, and someatosensory regions of the cat cerebral cortex by the use of an algorithm for assessment of dependence and feedback showed that mutual influences of these regions on each other during repetitive photic stimulation are not symmetrical in different stages of intertriai periods. The preponderance of influences of the somatosensory and parietal regions of the visual region, present in the prestimulus stages, increases in the poststimulus periods mainly on account of the fact that the influence of the visual region on the parietal and somatosensory regions becomes weaker immediately after photic stimulation. 2. Calculations of the weight of statistically significant connections between the cortical regions and their direction enabled the relative volume of the cell masses participating in the formation of connections between the regions to be estimated as a first approximation. As a result, overlapping of volumes of interacting cell masses was discovered in each of the regions examined; this evidently reflects the presence of organizing neuronal assemblages, responsible for mutually dependent connections in the system of interaction between cortical regions. 3. The facts obtained served as the basis for construction of a structural and functional model of interaction between the visual and somatosensory regions of the cortex during the after-periods following repetitive photic stimulation. The model represents a cycle of mutual influences of the visual on the somatosensory region and vice versa, constructed in accordance with the cortex→subcortex→cortex→cortex scheme. The essential components of this cycle are connections of the parietal region with the visual and somatosensory analyzer regions, carrying out interaction between the latter.

The model of electroluminescence in forward-biased MS and MIS light-emitting diodes based on the Auger recombination on the contact surface of the semiconductor is developed. Such a model may provide a light emission with the threshold voltage Uth = (Eg/2e) – (Efs/2e) < hνmax/e or even Uth = (hνmax/2e) – (Efs/e), depending on the physical processes involved. Here Eg, is the energy gap of the semiconductor, Efs the Fermi energy level in the semiconductor with respect to the c-band edge, hνmax the maximum of the electroluminescence band, e the electron charge. Experimental results obtained on ZnS MS and MIS diodes essential for this model are presented and analysed. It is found that the spectral distribution of diode emission remains practically unchanged at biases close to the threshold voltage Uth. The conclusion is drawn that the electroluminescence and the forward current have typical tunnel characteristics even in the case of ZnS MIS diodes with i-layers several thousand angstroms thick. The main physical properties of zinc chalcogenide light-emitting diodes are explained by means of the model developed. [Russian Text Ignored]

Electroluminescence, electrical and noise properties are investigated of ZnS metal-semiconductor light-emitting diodes which exhibit blue emission under forward voltage bias U ⪆ ⪆ 1.8 V; the external efficiency of such diodes attains 0.1%. A conclusion is drawn that such electroluminescence may be due to the injection of holes excited in the contact by Auger processes into the semiconductor. It is found that the forward current and, as a result, the electroluminescence intensity are limited by effect of surface levels being filled with electrons in the course of forward current passing.

1. If the similarity criteria (12)–(15) for anodic dissolution of geometrically similar specimens of one and the same metal are fulfilled, the strength of the metal is not affected by the scale factor. 2. In tests designed to simulate the effects of anodic dissolution processes, the duration of the test, electrolyte concentration, and current density must all be selected so as to satisfy the similarity conditions.

It has been shown that cyclic aging or conditioning during the tempering of quenched St. 35 steel specimens increases the intensity of diffusion phenomena and promotes the relaxation of residual stresses. Cyclic aging of the specimens at elevated temperatures is accompanied by cold hardening.

The corrosion-fatigue strength of steel 0Cr18Ni10Ti under axial-cyclic loads in aqueous NaCl and MgCl2 solutions at elevated temperatures and high pressures was studied. The results obtained indicate that the corrosion fatigue and stress corrosion of austenitic stainless steels are interrelated.

Static and fatigue strength of St. 20 steel smelted by various methods were determined at room and elevated temperatures. The results showed that vacuum-arc melted steel has the optimum physicomechanical properties.

New methods of investigating the corrosion-fatigue strength and stress-corrosion cracking of materials at elevated temperatures and pressures are described.

The effect of the structure state of carbon steel U8 on its resistance to stress-corrosion cracking in inhibited H2SO4 solutions was studied. It was shown that the maximum resistance to stress-corrosion cracking is displayed by steel strain-hardened by wire drawing, or treated by quench-hardening followed by tempering at a high temperature.

Blood thyrotropic hormone, thyroxin, tri-iodothyronine, FSH, LH, estradiol and progesterone levels were examined in 14 patients with primary hypothyroidism and 11 normal women of reproductive age. All the women under study were subjected to functional tests with intravenous thyroliberin (TRH) and metoclopramide. All hypothyroid patients had anovulatory infertility. Hyperprolactinemia was detected in 8 of 14 patients. It is demonstrated that hyperprolactinemia, developing in cases of primary hypothyroidism, is associated with impaired dopaminergic inhibition of pituitary lactotropics. Substitution thyroidin therapy resulted in the recovery of the normal ovulatory cycle in all but one patient with secondary pituitary microprolactinoma, and 8 patients became pregnant. It is believed that damaged dopaminergic regulation of hypothalamic luliberin (RH) secretion is a direct cause of ovarian dysfunction associated with primary hypothyroidism.

Data have been obtained on three cats for analysis of statistic connections of electrical activity in the visual, parietal and somatosensory cortical zones during development of evoked potentials to photic signal in these areas, and also in periods previous to photic stimulation and on traces of its action. An increase in shown of the influence of activity in the visual area on that of the somatosensory zone in post-stimulus periods and a sharp increase of two-way connections between these areas against the background of a relative equilibrium of direct and backward connections in trace periods.

In order to study the effect of proton beam irradiation on prolactinoma cells and hypophyseal intact cells tests with i.v. administration of TRH (200 micrograms) and LH-RH (100 micrograms) were performed in 16 women with prolactin-secreting adenomas before and in 2 mos.-2 years after irradiation of the pituitary body with a high energy narrow proton beam (1000 MeV) at a dose of 40-120 Gy. A curative therapeutic effect of proton therapy which was low with respect to reproductive function recovery, was combined with lowered functional reserves of hypophyseal thyrotrophs and gonadotrophs. The informative value of the tests with the releasing hormones was shown for the determination of damage of hypophyseal intact cells. The results suggest refractivity of adenomatous lactotrophs to radiation exposure and the hypothalamic level of disorder of ovarian function regulation in this pathology.

The effect of neuronal activity of one area in the cerebral cortex on the activity of another area was studied on adult alert cats with algorhythm of estimation of dependence and backward connection. On this basis a structural-functional model was developed of interaction between the visual and somatosensory cortical areas in the periods of aftereffect of repeated photic stimulations. This algorhythm permits to determine quantitatively the weight and direction of the mutual influences of these areas as well as to calculate approximately the volumes of the cellular masses which may participate in the formation of connections between these areas. It is assumed that the model may be used as one of the numerous means of studying the complex pattern of brain structures interactions.