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971.
L Milas I Nishiguchi N Hunter D Murray R Fleck H Ito E Travis 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1992,12(2-3):265-271
Protective effects of indomethacin, a prototype prostaglandin-inhibiting agent, against early and late sequelae of radiation injury (after X-rays or gamma rays) in mice were investigated. The following tissues or organs were examined: hematopoietic tissue, esophagus, jejunum, colon, lung, hair follicles, and tissues involved in the development of radiation-induced leg contractures. In addition, the effect of indomethacin was tested against radiation-induced carcinogenesis. In all experiments, the radiation was delivered as a single dose. Indomethacin led to significant protection of hematopoietic tissue, by a factor of 1.3. There was also some protection against radiation-induced pneumonitis and against radiation-induced carcinogenesis (protection factor of 1.2). The other tissues tested showed no change in their radioresponse after being treated with indomethacin. Thus, indomethacin can act as a radioprotective agent against both early and late sequelae of radiation, but its effect is dependent on the tissue tested. This protection is smaller than that observed with WR-2721. However, indomethacin combined with WR-2721 produced a radioprotective effect greater than the radioprotection achieved by individual treatments. 相似文献
972.
K.Ya. Kondratyev V.V. Kozoderov 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(6):105-109
Based on the 1974–78 NOAA data, characteristic features of the variability of the Earth's radiation budget and its components over the area of the Northern Atlantic have been analyzed. Calculations of the mean square deviation for the ERB and its components have let to the conclusions that anomalous regions of maximum variability may be considered as energy-active zones. 相似文献
973.
Radiosensibility of higher plant seeds after space flight. 总被引:4,自引:0,他引:4
E Vaulina I Anikeeva L Kostina 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(10):103-107
The influence of long-term storage of higher plant seeds under space flight conditions (49 to 827 days) on their radiosensibility was studied in the experiments on the orbital stations Salyut 6 and 7. Short-term storage has been proved to have no effect on radiosensitivity of Crepis capillaris seeds. Only in the case of maximal exposure duration the frequency of chromosome aberrations in post-flight irradiated seeds significantly exceeded the chromosome aberration frequency in the ground-based irradiated control. A statistically significant increase in the number of cells with multiple chromosome aberrations was also observed in this experiment. After gamma-irradiation of Arabidopsis thaliana seeds the germinating ability and survival rate of plants decreased depending on the duration of seed storage. Flight-exposed seeds were more sensitive to irradiations with respect to these parameters. A statistically significant increase in the frequency of recessive lethal mutations was observed only in two experiments of long exposure duration. 相似文献
974.
L J DeLucas C D Smith D C Carter P Twigg X M He R S Snyder P C Weber J V Schloss H M Einspahr L L Clancy A McPherson S Koszelak M M Vandonselaar L Prasad J W Quail L T Delbaere C E Bugg 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1992,12(1):393-400
The first microgravity protein crystal growth experiments were performed on Spacelab I by Littke and John. These experiments indicated that the space grown crystals, which were obtained using a liquid-liquid diffusion system, were larger than crystals obtained by the same experimental system on earth. Subsequent experiments were performed by other investigators on a series of space shuttle missions from 1985 through 1990. The results from two of these shuttle flights (STS-26 and STS-29) have been described previously. The results from these missions indicated that the microgravity grown crystals for a number of different proteins were larger, displayed more uniform morphologies, and yielded diffraction data to significantly higher resolutions than the best crystals of these proteins grown on earth. This paper presents the results obtained from shuttle flight STS-32 (flown in January, 1990) and preliminary results from the most recent shuttle flight, STS-31 (flown in April, 1990). 相似文献
975.
976.
K.B. Serafimov I.S. Kutiev Ts.P. Dachev 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(10):33-36
With data of satellite INTERCOSMOS-BULGARIA-1300 northern and corresponding southern hemisphere plasma densities have been compared. Southern densities are greater in the ?90 to ?180 and +30 to +120° ranges. The opposite is true for ?60 to +30°. No asymmetry has been observed during daytime. These results are explained by the variations of the magnetic declination. 相似文献
977.
H.E Revercomb L.A Sromovsky V.E Suomi R.W Boese 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1985,5(9):81-84
Corrected thermal net radiation measurements from the four Pioneer Venus entry probes at latitudes of 60°N, 31°S, 27°S, and 4°N are presented. Three main conclusions can be drawn from comparisons of the corrected fluxes with radiative transfer calculations: (1) sounder probe net fluxes are consistent with the number density of large cloud particles (mode 3) measured on the same probe, but the IR measurements as a whole are most consistent with a significantly reduced mode 3 contribution to the cloud opacity; (2) at all probe sites, the fluxes imply that the upper cloud contains a yet undetected source of IR opacity; and (3) beneath the clouds the fluxes at a given altitude increase with latitude, suggesting greater IR cooling below the clouds at high latitudes and water vapor mixing ratios of about 2–5×10?5 near 60°, 2–5×10?4 near 30°, and >5×10?4 near the equator. 相似文献
978.
The hypersonic hyperalfvèn plasma flow around electroconductive bodies is considered and electromagnetic inductive plasma-body interaction is analyzed. The possible applications of results obtained in this analysis to body motion in ionosphere and interplanetary plasma are discussed. 相似文献
979.
In manned space flights the renal function and water-salt metabolism undergo substantial changes. With the reserve capabilities of kidneys in mind, their function and regulation of the water-salt balance were investigated in cosmonauts postflight and in Earth-bound simulation experiments with the aid of water loading, hormonal injections (pituitrin, engiotensin, DOCA, ACTH); water- and ion-release were also studied during LBNP and physical exercises. The cosmonauts who performed space flights of 2 to 5 days showed water retention and increased urine excretion of salts during the first postflight days in response to a water load. After the 18-day flight water excretion remained unchanged whereas salt excretion increased. The capacity for osmotic concentration and urine dilution did not alter. The study of the hormonal effect in simulation experiments of different duration demonstrated a normal renal response to the hormonal excretion. After the LBNP tests and physical exercises the water- and salt-excretion declined; a correlation between the level of water- and salt-excretion and the level of these loads was established. The data on the blood- and urine-ionic composition, excretion of nitrogen metabolites, and hormones postflight as well as the results of load and functional tests suggest that changes in the renal function of cosmonauts in weightlessness are associated with regulatory effects on the kidney rather than disturbances in the function of nephron cells. 相似文献
980.
The influence of weightlessness on different parts of the motor system have been studied in crew members of 140 and 175 days space flights. It has been shown that weightlessness affects all parts of the motor system including (i) the leg and trunk muscles, in which severe atonia, a decrease of strength and an increase of electromyographic cost of contraction have been observed, (ii) the proprioceptive elements and the spinal reflex mechanisms in which decreased thresholds accompanied by decreases of maximal amplitude of reflexes and disturbances in cross reflex mechanisms have been found. and (iii) the central mechanisms that control characteristics of postural and locomotor activities. The intensities and durations of disturbances of different parts of the motor system did not correlate to each other, but did correlate with prophylactic activity during space flight. The data suggest a different nature of disturbances caused by weightlessness in different parts of the motor system. 相似文献