排序方式: 共有21条查询结果,搜索用时 15 毫秒
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Orlova AG Maslennikova AV Golubiatnikov GIu Kamenskiĭ VA Shakhova NM Babaev AA Snopova LB Ivanova IP Plekhanov VI Prianikova TI Turchin IV 《Biofizika》2011,56(2):349-355
The potentialities of diffuse optical spectroscopy for the noninvasive estimation of the oxygen state of experimental tumors have been demonstrated. The distribution of total, oxygenated and deoxygenated hemoglobin, as well as the level oxygen saturation of blood have been shown using two tumor models differing in the histological structure and functional characteristics. The results obtained by the optical method have been verified by immunohistochemical examination of tissue specimens with the exogenous hypoxia marker pimonidazole. 相似文献
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Maksimova I. V. Matorin D. N. Plekhanov S. E. Vladimirova M. G. Volgin S. L. Maslova I. P. 《Russian Journal of Plant Physiology》2000,47(6):779-785
The effects of light and temperature conditions on the maintenance of some red microalgae (order Porphyridiales) in collections were studied. Periodical subculturing on solid and liquid media was used for maintenance. Halophilic species P. aeruginosa, P. cruentum, and P. sordidum were lost in 2.5 months if kept in darkness. The viability of algae in the dim light slightly declined in 4–5 months and was species-dependent. The results were compared with earlier obtained data on mesophilic Chlorococcales. For the green algae, darkness proved to be the optimal condition, while their viability markedly decreased at light. It was suggested that this discrepancy was caused by the presence of phycobiliproteins in the cells of red algae. Dim light conditions are optimal for the synthesis of phycobiliproteins, which are rapidly destroyed in darkness, thus leading to cell death. 相似文献
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D. N. Matorin S. E. Plekhanov L. B. Bratkovskaya O. V. Yakovleva A. A. Alekseev 《Biophysics》2014,59(3):374-379
The effect of phenolics, present in wastes of pulp and paper industry, on photosynthesis in microalgae Scenedesmus quadricauda has been studied, analyzing the induction curves of prompt and delayed chlorophyll fluorescence and light curves of nonphotochemical quenching of fluorescence. Energization of photosynthetic membranes was impaired at low concentrations (0.1 mM) of phenol and pyrocatechol. At higher concentrations, phenol and pyrocatechol inhibited electron transport in PS II and increased the share of QB-nonreducing centers. As a result, the rate of P700 reduction declined. These results indicate that the parameters of fluorescence induction curves can be used for detecting phenol and pyrocatechol in the environment at early stages of toxic effects. 相似文献
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Changes in the level of heat shock proteins (HSP) in cells of freshwater protists, amoebae Amoeba proteus and ciliates Paramecium jenningsi, in response to changes in the environmental salinity were investigated. Changes in salinity levels were considered as a stress factor. The immunoblotting method revealed a polypeptide antigen cross-reacting with antibodies against bovine HSP70 in total protein extracts of both intact cells and cells subjected to salinity stress. The same polypeptide antigen was revealed in A. proteus cells subjected to heat shock. Therefore, it may be supposed that the polypeptide revealed after salinity shock is a heat shock protein related to the vertebrate HSP70. Under the impact of stress factor, well acclimated protists mostly spend their own previously accumulated HSP70. A conclusion is made that freshwater protists, living under conditions of increased salinity, appear to be preadapted to changes in environmental factors. 相似文献
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A. G. Nedosekin K. P. Khazanova L. B. Bratkovskaya S. E. Plekhanov 《Moscow University Biological Sciences Bulletin》2013,68(4):192-194
Reduced intensity of delayed fluorescence of chlorophyll and suppressed growth recorded in an experimental population of Scenedesmus quadricauda under the influence of pyrocatechol demonstrate reduction in efficiency of light reactions of photosynthesis, which, in turn, determines deterioration of algae productivity. 相似文献
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Early effects of 0.0001–10 mM sodium pentachlorophenate (PCP-Na) on the green alga Chlorella pyrenoidosa Chick. S-39 involves a rapid (within 1–2 min) decrease in the light-induced oxygen evolution by algal cells. The suppressed relative yield of variable chlorophyll fluorescence in C. pyrenoidosa in the presence of high PCP-Na concentrations and its dynamics provide evidence for rapid inactivation of photosystem 2, which is not observed at low concentrations of the toxicant. An analysis of the induction curve of delayed chlorophyll fluorescence in algal cells suggests that PCP-Na at low concentrations disturbs the coupling of electron transport and phosphorylation, whereas at high concentrations it inhibits electron transport and decreases the energy potential of photosynthetic membranes. The early toxic effect of PCP-Na is responsible for subsequent impairment of C. pyrenoidosa productivity. 相似文献
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Kinetic analysis of macroscopic fluctuations in alcohol dehydrogenase reaction was carried out. The integral form of Michaelis-Menten equation was used. It is shown that reaction rate fluctuations to be observed in experiment are connected with kinetic constants of relative affinity of ADG to NAD and NAD X H. 相似文献