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Biomedical subjects

G F Nikolashin

Publications and source records attributed to G F Nikolashin.

8 recordsLinked to original sources
PubMed2001

[The effect of G-loads on gravity tolerance of monkeys Macaca rhesus during antiorthostatic hypokinesia].

Reported are results of 200 centrifuge runs of 24 monkeys Macaca mulatta. Microgravity effects were simulated by 4-wk immobilization with the head tilted down at -6 degrees. The investigation was divided into two series. During series-1, one group of animals was not exposed to centrifugal training, whereas the other group was exposed to +Gz at the magnitudes of 1.2, 1.4 and 1.6 G for 30-40 min 4 to 5 times a week. In series-2, again one group of animals was not trained on the centrifuge but the other was trained at +1.2 Gz for 30 min 2 or 3 times a week. Functional testing by 30-s runs at +3 Gz was performed before and after head-down immobilization. Deterioration of g-load tolerance following simulated microgravity in both groups of untrained macaques was ascribed to the deconditioning effect of simulated microgravity on the body systems. Centrifugal training had, as a rule, positive effect on g-tolerance of the animals though it failed to fully eliminate the negative consequences of simulated microgravity. This means that search after optimal protocols of application of artificial gravity generated by centrifuge needs to be continued. Evaluation of the effectiveness of combining centrifugation with other countermeasures against the adverse effects of microgravity and development of associated protocols can be another area of future research.

Adaptation, Physiological↗
PubMed2001

Modern view on the short-arm centrifuge as a potential generator of artificial gravity in piloted missions.

The problem of artificial gravity (AG) in long-term missions is one of the hottest, as the existing countermeasures do not fully cope with the negative consequences of weightlessness. From two variants of AG creation--rotation of space systems around of their mass center or short radius centrifuge (SAC)--the preference is given to SAC, as technically easier variant for realization. However, the rotation of a person on SAC can cause not only positive, but also negative effects. The purpose of the present study was to perform the analysis of data of researches on a problem of AG generated by a of SAC, executed in Russia during last 20 years, and to state modern views on application of SAC as a mean of AG creation in long piloted missions.

Adaptation, Physiological↗
PubMed2000

[Technique for registration of auricular pulsogram in macaca mulatta monkeys].

An upgraded technique for registration of auricular pulsogram in monkeys (Macaca mulatta) has been proposed to study shifts in the common artery bed. The measurement is made with a photo-electrical sensor taped to the cartilage of the floor of the auricle and secured with a special cap and helmet of elastic net, and a system for data transfer from the sensor to a register enhanced by preamplifiers. Potentialities of the technique are exemplified by the investigation of Macaca mulatta's tolerance of +Gz loads.

Animals↗
PubMed1995

[The Jupiter-2 slow-rotation system].

The experience of space missions shows that functional disorders in crewmembers on the type of space motion sickness (SMS) may develop on the initial stage of flight. Longer exposure in micro-g causes a wide range of debilitative changes in the vital body systems. Artificial gravity produced by spacecraft rotation might be a universal tool to counteract the impacts of prolonged microgravity on the human body. However, the significance of SMS does not become less high because of a new factor, i.e. the rotating environment. Research system Jupiter 2 is a stand-alone slow-rotating ground facility for simulating motion sickness equivalent to its space form. The merits of this facility are the possibilities to control the intensity of exposure, perform long-term investigations of two active subjects simultaneously, and study the stages of body adaptation to this agent, and assess physical and operator's performance. The facility carries large expectations to occupational selection.

Equipment Design↗
PubMedDate not supplied

[Complex apparatus for remote study of external respiration].

A complex set of instruments ensuring telerecording of the basic ventilation and gas exchange values is described. The set provides for the possibility of delivering various gas mixtures to the examinee. The set was mounted, tested and operated with a centrifuge under radial overloads of up to 12Gx. A six-year experience of its operation demonstrated its reliability, accuracy and reproducibility of the results obtained.

Evaluation Studies as Topic↗
PubMedDate not supplied

[Prognostication of man's health status in response to gravity-induced blood shifts based on continuous noninvasive measurement of arterial blood pressure using the Pen'iaz method].

Exposure to +Gz acceleration, orthostatic tilt tests and LBNP tests causes distinct blood shifts and deterioration of cerebral circulation. In this case syncope episodes may be prevented by continuous monitoring of circulation parameters, specifically arterial pressure (AP). Our investigations have shown that continuous AP measurement by the Penjaz noninvasive technique may help earlier prediction of the health status in response to gravity-induced blood shifts. In this situation the development of a pre-collapse state is preceded by an emergence of distinct AP waves of the second-third order accompanied by a critical drop of pulse pressure. It is concluded that continuous AP measurement in the finger according to the Penjaz noninvasive technique holds promise as a medical monitoring method in a altered gravitational field.

Acceleration↗