Effects of 1 M NaCl on the lipid profile of detergent-resistant membranes in chloroplasts and mitochondria of salt-accumulating halophyte plants of family Amaranthaceae,
Salicornia perennans
Willd. ...and
Suaeda salsa
(L.) Pall. were studied. The composition of lipids and fatty acids in detergent-resistant membranes differed from total lipids of chloroplast and mitochondrial membranes by the abundance of cerebrosides and sterols. Under the given salinity level, a manyfold increase in the relative content of cerebrosides was noted in the composition of detergent-resistant chloroplast membranes of
S. perennans
. A similar salinity-related increase in cerebroside content was detected in detergent-resistant mitochondrial membranes of
S. salsa
. The opposite effect was observed for sterols: their relative content decreased under the action of salt. The results indicate that the detergent-resistant membranes are involved in the interactions of chloroplasts and mitochondria in the cell response of halophytes to salinity.
Modern concepts on structural, physiological, and biochemical aspects of salt tolerance of higher plants were considered. Integral physiological processes, such as growth and photosynthesis of ...glycophytes and halophytes in the context of their ecological plasticity, variety of their adaptive strategies developed in the course of their evolution, and natural selection, were discussed. Analysis of the known anatomical and morphological adaptations of halophytes (succulence, special salt-excreting structures, features associated with special tissues growth, leaf kranz-anatomy and mesostructure) providing their salt tolerance was conducted. The most important physiological and biochemical adaptations of such plants to salinity related to uptake, accumulation and excretion of Na
+
and Cl
–
, peculiarities of membrane composition and the pigment system, and protection against osmotic and oxidative stresses were described. The association of physiological and biochemical peculiarities of halophytes with ecological salt tolerance strategy was discussed.
We study a magnetosphere‐ionosphere coupling at low latitudes during a moderate (corotating interaction regions/high‐speed solar wind streams‐driven) geomagnetic storm on 22 July 2009. Recently, it ...has been shown that during major (coronal mass ejection‐driven) storms, quasi‐trapped >30 keV electrons largely enhance below the radiation belt in the forbidden zone and produce an additional ionization in the topside ionosphere. In this work, we examine a case of the recurrent storm when the magnetosphere‐ionosphere coupling through the quasi‐trapped electrons also may take place. Data from NOAA/Polar‐orbiting Operational Environmental Satellite and Japanese Greenhouse gases Observing Satellite were used to identify the forbidden electron enhancement (FEE). We find a positive vertical gradient of the electron fluxes that indicates to the radiation belt as a source of FEE. Using global ionospheric maps, radiotomography reconstructions from beacon data and COSMIC/FORMOSAT‐3 radio occultation measurements, we have observed an unusually large area in the nighttime ionosphere with increased total electron content (TEC) and prominent elevation of the F layer at low latitudes that coincides with FEEs spatially and temporarily. Ionizing particles are considered as an addition source of ionization along with generally accepted mechanisms for storm time TEC increase (a positive ionospheric storm). We discuss relative contributions of the FEE and disturbance dynamo electric field in the TEC increases during the storm recovery phase.
Key Points
During a recurrent storm, energetic electrons enhance in forbidden zoneAt recovery phase, TEC increases in the low‐latitude ionosphereIonizing effect of energetic electrons is significant in the F region
Based on the CICE model, the characteristics of the ice cover in the Northern Caspian Sea were simulated during the extreme ice seasons of 2011/2012 (long and cold) and 2015/2016 (short and warm). ...The characteristics of these seasons (length, frost degree-days, sea ice extent, maximum ice thickness) are given. Composite anomalies of surface air pressure and air temperature were constructed for the Northern Caspian region. Based on the JRA-55 reanalysis data, the concentration and thickness of sea ice were calculated. A comparison of the simulation results with observational data showed that the main differences in ice conditions in these seasons are reproduced satisfactorily.
Despite the long-term studies of mesoscale cyclones in the Arctic region that started in 1960, this atmospheric phenomenon has not been fully understood yet and is extremely difficult to predict. ...This is mainly due to the lack of satellite monitoring of the atmosphere in the northern polar latitudes with a high temporal resolution and an extremely sparse network of ground-based observations in the Arctic. On February 28, 2021, the Russian
Arktika-M
No. 1
satellite was launched, which is the world’s first hydrometeorological satellite operating in a highly elliptical Molniya-type orbit. The launch of this unique satellite with a multichannel scanning unit (MSU-GS) as the main onboard mission equipment opened a possibility of obtaining data on the state of the atmosphere over the entire Arctic region with a frequency of 15/30 min during the working section of the satellite orbit. In particular, obtaining these data makes an invaluable contribution to solving the problems of monitoring and studying mesoscale cyclones in the northern polar latitudes, which is clearly shown in the present paper. The first summary results of monitoring mesoscale cyclones are presented as a map of their occurrence frequency. The potential of using the
Arktika-M No. 1
MSU-GS data coupled with data of the regional hydrodynamic forecast model to perform synoptic analysis by the example of the manifestation of mesoscale cyclogenesis in the Barents Sea on May 31, 2021, is demonstrated.
In this work, we studied the sorption of scandium, whose isotopes
44
Sc and
47
Sc are explored for diagnostics and therapy in nuclear medicine, by aggregates of commercial (TAN, STP) and oxidized ...nanodiamonds (ox-STP) from aqueous solutions. The sorption capacity of the studied NDs for scandium was determined; 100 μg of NDs is found to be sufficient for the sorption of 1 GBq of
47
Sc, which is equivalent to the activity of isotopes used in therapy. It was shown that the supposed mechanism for the binding of Sc(III) to nanodiamond aggregates is chemisorption, and the chemical composition of the nanodiamond surface affects the sorption efficiency to a greater extent than the speciation of scandium in solution. The obtained data on Sc(III) sorption are correlated with the sizes of nanodiamond aggregates; it is shown that sorption under experimental conditions does not depend on the size of the aggregates. For the further development of radiopharmaceuticals based on
47
Sc, optimal carriers for this isotope—TAN and ox-STP—were suggested.
Nanodiamonds (NDs) are promising carriers of radionuclides in radiopharmaceuticals for the use in nuclear medicine. In this work, we investigated the influence of the properties of NDs suspensions, ...including the sizes of their aggregates, in aqueous solutions with different pH on their binding of medical isotopes
90
Y and
177
Lu and determination of conditions for fabricating promising conjugates for further in vivo studies. It was shown that sorption is influenced by the composition of the solution, which determines the properties of the NDs surface, while the forms of cations of the studied nuclides in the solution do not affect the sorption value.
The work investigated the sorption of no-carrier-added
177
Lu isolated from neutron-irradiated
176
Yb
2
O
3
, and carrier-added
177
Lu obtained by irradiation of
nat
Lu
2
O
3
, by commercial and ...oxidized nanodiamonds (NDs) of various grades from aqueous solutions to identify among them a promising carrier for further research in the field of nuclear medicine. A promising sorbent was found: oxidized NDs of the STP grade (ox-STP); conditions for the fast sorption of lutetium with it in an amount equivalent to 1.2 GBq of no-carrier-added
177
Lu were determined, which corresponds to the activity used in therapy.
The initial phase of a major geomagnetic storm on 14 December 2006 was selected in order to investigate the ionizing effect of energetic electrons in the ionosphere. The global network of GPS ...receivers was used to analyze the total electron content (TEC). A strong positive ionospheric storm of ~20 TEC units (TECU) with ~6 h duration was observed on the dayside during the interval of northward interplanetary magnetic field. At the same time, the NOAA/POES satellites observed long‐lasting intense fluxes of >30 keV electrons in the topside ionosphere at middle and low latitudes, including a near‐equatorial forbidden zone outside of the South Atlantic Anomaly (SAA). We found that the TEC increases overlapped well with the enhancements of energetic electrons. Modeling of the ionospheric response by using a Global Self‐consistent Model of the Thermosphere, Ionosphere, and Protonosphere, based on the standard mechanisms of plasma transport, could only partially explain the ionospheric response and was unable to predict the long‐duration increase of TEC. For the energetic electrons, we estimated the ionizing effect of ~45 TECU and ~23 TECU in the topside ionosphere, respectively, inside and outside of SAA. The ionizing effect contributed from 50% to 100% of TEC increases and provided the long duration and wide latitudinal extension of the positive ionospheric storm. This finding is a very important argument in supporting significant ionizing effect of energetic electrons in the storm time ionosphere both at middle and low latitudes.
Key Points
TEC increases in the low‐ and middle‐latitude ionosphere at the initial storm phase
Greater than 30 keV electron fluxes enhance significantly at the initial storm phase
Energetic electron enhancements produce significant ionizing effect in the ionosphere
PDF