Найдено научных статей и публикаций: 1524   
171.

Нейтринo-электронные процессы в плотной замагниченной плазме     

E. Н. Нарынская - Вестник Молодых Ученых , 2002
The neutrino-electron processes in a dense strongly degenerate magnetized plasma are analyzed in the framework of the Standard Model. It is shown that under conditions μ2 > eB >> μ T, when the plasma electrons and positrons occupy the excited Landau levels, the total set of neutrino-electron processes reduces to the neutrino scattering on the excited electrons with Landau level number conservation. The mean values of the neutrino energy loss is calculated. It is found that neutrino-electron process does not give a contribution into the neutrino force acting on plasma along the magnetic field 
172.

Формализация процедуры прогнозирования динамических проявлений в массиве горных пород     

В. И. Герман - Вестник Молодых Ученых , 2002
This paper is concerned the development of the formalized forecasting technique of large fractures accompanying with a large energy radiation. Input data for the forecasting procedure is the time-space distribution of small-sized fractures. The suggested procedure was applied to microseismic catalogue of North Ural bauxite mine. The efficiency of the forecasting and its stability with change of procedure parameters is considered 
173.

Влияние случайных полей в кристаллах на рекомбинационную люминесценцию     

Б. Н. Яценко - Вестник Молодых Ученых , 2002
In present work we investigate the influence of electric fields on recombination luminescence kinetics in wide bandgap crystals. Random field distribution functions are analyzed. Average influence of random fields on recombination probability is evaluated. The process of correlated electrons and holes recombination with account for Coulomb interaction and influence of external electric field is considered. In simple case of random fields created by charge carriers in highly excited regions the recombination rate is proportional to n2/37 rather than n, where n is the concentration of excitations 
174.

Фуллерено-подобные структуры как проекции многомерных регулярных решеток     

А. В. Сабуть - Вестник Молодых Ученых , 2002
In this paper the method of determination of many-dimensional regular lattices with given elements of set of such lattices. The analysis of a symmetry of coordination polyhedrons of orthogonal projections of four-dimensional lattices with a pentagonal symmetry is carried out. Is established, that some coordination polyhedrons have penta-, nano-, decagonal symmetry of edges, it explains existence atomic nanoparticles with a non-crystallographic symmetry 
175.

Регуляция центральных звеньев гипоталамо-гипофизарно-адренокортикальной системы при длительном воспалительном стрессе     

А. Б. Ресненкон. А. Абрамоваа. В. Мишарин - Вестник Молодых Ученых , 2002
Hypothalamic pituitary adrenocortical (HPA) axis is the major biological machinery for adaptation to stress of different as in genesis and duration. The central limb of the axis are parvicellular neurons of hypothalamic paravetricular (PVN) nucleus, which produce corticotrophin releasing hormone (CRH) and vasopressin (VP). The later is the synergist of CRH in effects on pituitary ACTH cells. In the present study, we aimed to investigate expression of CRH and VP genes within chronic inflammatory stress caused by prolonged treating with increasing dose of bacterial endotoxin (from 25 to 250 mkg/100g). It has been shown by in situ hybridization methodology that extended endotoxemia resulted in decrease of CRH messenger RNA (mRNA) levels, but increase in VP mRNA levels in parvicellular neurons of PVN. At the same time basal synthesis of proinflammatory cytokine IL-1 mRNA in the brain circumventricular organs was maintained. It might affect neurohormonal gene expression in the parvicellular PVN neurons and lead to paradoxical response of HPA axis to chronic inflammatory stress 
176.

Роль nmda-рецепторов в реализации нейрональных механизмов действия пептида, вызывающего дельта-сон     

Л. К. Павловат. С. Павловап. Е. Умрюхин - Вестник Молодых Ученых , 2002
Delta-sleep inducing peptide (DSIP) increases individual resistance of animals to the emotional stress. Preliminary DSIP injection suppresses stress-induced immediate early gene c-Fos expression. Increase in the glutamate content during stress induces immediate early gene expression and leads to the excitotoxicity. DSIP microiontophoretic application in 18 Wistar, Wag and Fisher male rats induced increase of the neuronal activity in sensorimotor cortex, dorsal hippocampus, ventral anterior thalamic nucleus and lateral hypothalamus. N-methyl-D-aspartate non-competitive antagonist MK-801 application suppresses neuronal activation during DSIP microiontophoresis. Present study demonstrates participation of NMDA-receptors in the mechanisms of antistress effects of DSIP that can explain stress coping activity of this nonapeptide 
177.

Отражение психофизиологического состояния ребенка первого полугодия жизни в звуковых сигналах     

М. И. Павликовам. А. Новикова - Вестник Молодых Ученых , 2002
The adults ability to determine a psychophysiological state on sound signals of infants 2.5 and 6 months of age was examined. The differences in character of recognition of sound signals by the men and women, and also persons who were experienced in infant care are revealed. It was defined the acoustic variables related to rates of emotional specificity. It was obtained that the signals of sharp discomfort are characterized by the highest values of duration, average fundamental frequency and energy of high frequencies, in comparison with signals weak discomfort and comfort. The age dynamics of fundamental frequency had different tendencies depending on functional state. The results allow to consider that negative emotional component of infant's vocalizations become more clear between 2.5 month and 6 months of life 
178.

Сопоставление гласноподобных звуков младенцев и гласных взрослой речи     

А. П. Самокищук - Вестник Молодых Ученых , 2002
The aim of study was the comparative analysis of acoustic parameters of adults' speech vowels and infant's vowel-like sounds. In consistence with previous data it was shown that infant's sounds compared to adult', exhibits higher fundamental and formant frequencies. Moreover, in two-formant plane the formants' values of the vowel-like sounds overlapped in the high-frequency region of the different adult' vowel categories. As result preverbal vocalization are not characterized by the vowel-specific formant patterns in contrast with adults' one. Comparative spectral analysis of vowel-like phonetically distinct sounds ([a]- and [u]-like) reveals statistically significant differences (p
179.

Влияние катионов тяжелых металлов на содержание гликогена в тканях пресноводных моллюсков     

Е. А. Шпакова - Вестник Молодых Ученых , 2002
The energy required for the various processes of life of water mollusks was accumulated in the mollusk tissues as a polysaccharide glycogen. The damage influences disturb the glycogen metabolism and change the content of glycogen in mollusk tissues. The aim of the work was investigation of influence of heavy metal cations on the content of glycogen in the tissues of the bivalve mollusk anodonta (Anodonta cygnea) and the gastropod mollusk katushka (Coretus corneus). It was shown that incubation of the mollusks in water with Cu2+ and Cd2+ (1 mkM) led to a decrease in the content of glycogen in all tissues, which we investigated (hepatopancreas, muscles, mantle). The level of glycogen was depended on time of incubation of the mollusk incubation in the presence of heavy metal cations and species of the mollusks. A decrease in glycogen content was most essential in hepatopancreas. The investigation of the influence of Hg2+, Cu2+, Pb2+, Cd2+, Ni2+ and Zn2+ on the content of glycogen in hepatopancreases of the mollusks give the next order for cations according to its toxicity: for A. cygnea — Hg2+> Cu2+=Pb2+>Cd2+>Ni2+= Zn2+, for C. corneus Hg2+>Cu2+=Cd2+>Pb2+> Zn2+=Ni2+ 
180.

Ca2+-активируемые протеолитические ферменты у рыб и водных беспозвоночных     

Л. А. Бондарева - Вестник Молодых Ученых , 2002
Ca2+-activated proteolytic enzymes (calpains) in pike Esox licius L., roach Rutilus rutilus L., mussel Mytilus edulis, amphipodes Gammarus sp. were studied by gel-chromatography on Sephacryl S-200 columns. The correlation between the level of activity, distribution of forms and some other calpain properties with evolutionary, physiological, ecological characteristics of the studied organisms was shown. Relatively high calpain activity in sea invertebrates was observed in comparison with fish