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With the rapid development of wireless communication technologies and the miniaturization trend in the electronics industry, the reduction of electromagnetic interference has become an important issue. To solve this problem, a lot of attention has been focused on polymer composites with combined functional fillers. In this paper, we report a method for creating an acrylonitrile butadiene styrene (ABS) plastic composite with a low amount of conductive carbon and magnetic fillers preparation. Also, we investigate the mechanical, thermophysical, and electrodynamic characteristics of the resulting composites. Increasing the combined filler amount in the ABS composite from 1 to 5 wt % leads to a composite conductivity growth of almost 50 times. It is necessary to underline the temperature decrease of 5 wt % mass loss and, accordingly, the composite heat resistance reduction with an increase in the combined filler from 1 to 5 wt %, while the thermal conductivity remains almost constant. It was established that electrodynamic and physical–mechanical characteristics depend on the agglomeration of fillers. This work is expected to reveal the potential of combining commercially available fillers to construct effective materials with good electromagnetic interference (EMI) protection using mass production methods (extrusion and injection molding). [ABSTRACT FROM AUTHOR]

Prorocentrum minimum is a potentially toxic marine dinoflagellate that often forms massive blooms in estuarine and coastal sea waters. In this study, the life cycle of P. minimum was investigated and sexual reproduction in culture was described for the first time. Morphology of the mitotic stages was revised and several distinguishing features from sexual steps were described. The sexual reproductive stages were observed in the stationary culture and compared with a well‐studied closely related species, Prorocentrum micans. Prorocentrum minimum has a haplontic life cycle and homothallic sexual process. The gametes were isogamous and morphologically indistinguishable from the vegetative cells. Unlike P. micans, P. minimum isogametes fused, but did not conjugate, partially reorganizing their cell coverings. Newly formed planozygotes were distinguished by their irregular shape and a large asymmetrically located nucleus. No long‐term resting cyst stages (hypnozygotes) were documented. The late planozygotes underwent meiosis and formed tetrads of cells. The second meiotic division could be delayed or arrested in one of the daughter nuclei leading to formation of trinucleate cells with three pairs of flagella. So, similar to P. micans, P. minimum may have two possible scenarios of sexual division: (a) formation of a four‐cell stage through two successive divisions or (b) asynchronous divisions of the zygote. Changes in the DNA content were confirmed by quantitative image cytometry. [ABSTRACT FROM AUTHOR]

SUMMARY: The specific cell architecture of prorocentroid dinoflagellates is reflected in the internal cell structure, particularly, in cytoskeleton organization. Cytoskeleton arrangement in a Prorocentrum minimum cell was investigated using fluorescent labeling approaches, electron‐microscopy and immunocytochemical methods. The absence of cortical microtubules was confirmed. Phalloidin – tetramethylrhodamine isothiocyanate conjugate staining demonstrated that F‐actin forms a dense layer in the cortical region of the cell; besides, it was detected in the ‘archoplasmic sphere’ adjacent to the nucleus. In some cells the rest of the cytoplasm and the nucleus were also slightly stained. In dividing cells, F‐actin was mainly distributed in the cortical region and in the cleavage furrow. Fluorescent deoxyribonuclease I staining demonstrated more evenly distributed cytoplasmic non‐polymerized actin; the basis of the nuclear actin pool is monomeric actin. It concentrates in the nucleoplasm and forms a meshwork around chromosomes. The significant amount of G‐actin is apparently localized in the P. minimum nucleolus. Assumed involvement of F‐actin in the process of stress‐induced ecdysis – cell cover shedding – was examined. A sharp decrease in the level of ecdysis was observed after treatment with actin‐depolymerizing agent latrunculin B. The fluorescent staining of treated cells demonstrated disturbance of the actin cytoskeleton and disappearance of the cortical F‐actin layer. Our results support the recent data on the actin involvement in fundamental nuclear processes: cytoplasmic F‐actin appears to participate in cell shape determination, cell cover rearrangement and development. Actin may play a substitute role in the absence of cortical microtubules, representing the cytoskeletal basis of P. minimum cell architecture. [ABSTRACT FROM AUTHOR]

Abstract Estuarine and coastal environments are vulnerable to alien species invasions. Many nonindigenous organisms demonstrate high ecological plasticity, which is particularly well expressed in unicellular eukaryotes. In this study, responses of the potentially toxic invasive dinoflagellate Prorocentrum minimum , initially acclimated to salinity 17 (control), to short-term stress by salinities 4, 8 and 35 were investigated experimentally by determination of mortality, alterations in cell cycle and chromosome fine structure, RNA synthesis and DNA replication. The percentage of dead cells within the P. minimum population after stress by critical salinity 8 was lower compared to the other tested conditions. Salinity stress caused only moderate impact on the cell cycle pattern; changes of chromosome fine structure at salinities 4 and 8 were evident though reversible. We disclosed the elevated RNA synthesis and DNA replication which can play a ‘compensational’ role by speeding up the metabolic (synthetic) activity of these protists at the critical salinity conditions. The increased RNA synthesis in phase G1 and additional DNA replication in phase S of the cell cycle likely enhance salinity tolerance and cause relatively low mortality of these micro-eukaryotes at salinity 8. We infer that the enhanced synthesis of DNA and RNA can be one of the advanced ecological strategies of P. minimum which along with the other cellular and physiological characteristics (small body size, planktonic mode of life, fast reproduction, high evolution rates, mixotrophy, ability to form cysts, etc.) helps these dinoflagellates to invade successfully and populate permanently coastal ecosystems, remaining highly competitive in the unstable brackishwater environments. Highlights • Salinity stress causes only moderate impact on cell cycle of P. minimum. • Mortality of P. minimum stressed by salinity 8 is lower than at salinities 4 and 35. • Enhanced DNA replication in P. minimum cells at salinity 8 is revealed. • Elevated RNA synthesis as P. minimum stress response peaks at salinity 8. • Chromosome fine structure at salinities 4–8 changes evidently but reversibly. [ABSTRACT FROM AUTHOR]