The bactericidal properties of cloths modified with bimetallic Cu-Ag and Fe-Ag and monometallic Ag nanoparticles, including against the most resistant bacteria strains and those associated with ...nosocomial infections such as
Escherichia coli
,
Staphylococcus aureus
,
Acinetobacter baumannii
,
Pseudomonas aeruginosa
,
Klebsiella pneumoniae
,
Enterococcus faecalis
, and
Enterobacter aerogenes
, were investigated. Photomicrographs obtained using a JEOL JSM-6390 LA scanning electron microscope were presented. The substrates acquired colors characteristic of reflectance spectra taken on a Shimadzu UV-2401PC spectrophotometer during the modification process.
Unique data were obtained on the abnormally high level of phytoplankton biomass (30 g m
–3
) in the marginal ice zone of the deep-water High Arctic (the Nansen Basin, 83° N) during observations ...onboard a ship in the summer of 2020. The changes in species composition and the increase in abundance of plankton phytocenoses were determined by the complex hydrographic structure formed due to the interaction between the warm Atlantic and cold Arctic water masses and confirmed the important role of the North Atlantic Current in the European sector of the Arctic Basin. For the first time, a reliable relationship was established between the phytoplankton productivity and the halocline depth (an indicator of rising Atlantic water enriched with nutrients, primarily nitrogen). It was shown for the first time that the large cryopelagic centric diatom
Porosira glacialis (= Podosira hormoides
var.
glacialis)
can be a species forming phytoplankton bloom in the marginal ice zone of the High Arctic.
Primary production (PP) and the chlorophyll-a concentration (chl-a) in the European Arctic in the summer of 2020–2021, where continued climatic warming and increased “Atlantification” accelerate the ...sea ice losses, are discussed. The maximum integrated PP and the total chl-a content were observed in the marginal ice zone (MIZ) of the Barents Sea under weakened stratification of the water column and reached 1109 mgC m
–2
day
–1
and 118 mg m
–2
. Near the ice edge in the Nansen Basin, the main part of PP formed in the upper mixed layer and did not exceed 469 mgC m
–2
day
–1
; the chl-a content reached 56 mg m
–2
. The early and late stages of phytoplankton bloom in the MIZ were characterized by the leading role of picophytoplankton in carbon fixation. Large centric diatoms, microphytoplankton, were recorded to dominate in the MIZ at the stage of peak bloom in 2020 under the dense ice cover of the Nansen Basin. A similar phenomenon was observed earlier only in the Arctic shelf seas and was not recorded in the high-latitude basins of the Arctic Ocean. With the sparse ice cover of the Nansen Basin in 2021, the main primary producers were pico- and nanophytoplankton. The low variability of assimilation numbers (1.7 ± 0.3 mgC mg chl-a
–1
h
–1
) at all bloom stages indicates indirectly the acclimatization of different species of phytoplankton to the environmental changes. The ecological flexibility of the primary production link of the MIZ ecosystems in the studied seas of the European Arctic during the period of climate changes is confirmed.
Comprehensive study of sections of mares in the Bolshaya Ussurka River basin has allowed highlighting climate changes over the past 2900 years. Reconstructions are based on the data of botanical, ...diatom, and palynological analyses and radiocarbon dating. The moisture content changed most significantly. Periods of prolonged droughts, which coincided with the weakening of the summer monsoon, were established. A long dry period continued from about 2900 up to 1360 yr BP. Dry conditions did not exclude floods caused by heavy rain caused by the passage of typhoons or deep cyclones. The Medieval Warm Period and Little Ice Age were humid and characterized by increased cyclogenesis. There were short-term fluctuations in humidity: droughts about 530–460 yr BP ago, then conditions became more humid about 400 yr BP and especially about 330–260 yr BP ago. The age ranges of periods with different flood activity and paleo-fires were determined. Events were correlated with data on regional and global events. A different response of mountain and bog landscapes to short-period climatic changes has been established. The role of the Korean pine in forest vegetation changed significantly; its distribution is controlled by changes in the hydroclimatic conditions. The optimum environments for the development of Korean pine forests were 780–530 yr BP ago. The role of Korean pine decreased during dry phases and after fires. The most variable vegetation of the mares was during the Little Ice Age. Modern anthropogenic changes in landscapes are also recorded in the sections. The scale of floods has significantly increased under human impact.
The recombinant
B. anthracis
strain 55ΔTPA-1Spo
–
was used for the development and trial of a method for the simultaneous production of immunogenic anthrax antigens, a protective antigen, and the EA1 ...protein of the S layer, which are components of a prototype anthrax vaccine. The proposed method includes inoculum preparation, cultivation in liquid medium without antibiotics, sterilizing filtration, concentration, diafiltration, and chromatographic purification on various carriers. This method provides for a high yield of both target products. The purified antigens (alone or in combination with each other) were shown to have no toxic effect on organs and tissues of vaccinated laboratory animals in amounts that were several times higher than immunizing doses. The minor changes revealed by histological examination reflect the adaptation-compensatory reactions of the macroorganism and tend to normalize. The response of immune-competent organs corresponded to moderate development of immunogenesis. The addition of EA1 protein to the recombinant protective antigen resulted in an increase in the expression of the genes determining TLR of innate immunity. Immunization of laboratory animals with the combined preparation caused more pronounced immunobiological alterations in lymphoid organs than the use of only the protective antigen.
The Murav'ev-Amursky Peninsula is one of the most densely populated and industrially developed regions in the Russian Far East and is included in Bolshoy (Greater) Vladivostok. Before its intensive ...development began approximately 150 years ago, the mountainous portion of the peninsula was covered by coniferous forests, with mixed broadleaved forests confined to the coastal lowlands. Vegetation was notably transformed during industrial development. The landscape evolution and development of native communities under Middle/Late Holocene short-time climate changes are of particular interest. The results allow the relative importance of natural and anthropogenic factors in landscape transformation to be determined. Integrated studies of marine and terrestrial sequences on the Murav'inaya Bay coasts form the foundation for reconstructing changes in the Murav'ev-Amursky Peninsula landscapes over the last 5950 cal. Yrs. Pollen and diatom analyses as well as radiocarbon dating provide insight into the landscape response to climate fluctuations during the Middle/Late Holocene. Changes in the depositional environments were essentially controlled by fluctuations in the level of the Sea of Japan, as illustrated by the reconstructed history of Cherepashye Lake, which formed ∼2000 cal. Yr BP and replaced a lagoon. Several stages in this evolution show variations in the degree of connection with the sea. The materials obtained made it possible to reconstruct the environments at the time when site Cherepakha-13 came into being. The site appeared under climatic conditions similar to those of today, and the sea level was below the present sea level (Zaisanovskaya archeological culture). The people of the Lidovskaya and Yankovskaya archeological cultures settled under a climate warmer than that at present, with a sea level above the present-day sea level, and broadleaved forests with Korean pine grew on the coast. During the Yankovskaya and Krownovskaya cultural period, the climate began to cool and the sea level dropped. These changes led to deterioration of living conditions of these people. In the 13th century, when a Jurchen settlement appeared at Murav'inaya Bay, the coastal plain was dominated by Korean pine-broadleaved forests, and mixed forests were poorer in composition than the earlier forest vegetation. Additionally, alder woodlands became widespread around the lake. In the 17th to 19th centuries, coniferous tree species (and Korean pine in particular) abruptly gained in importance in the vegetation of the peninsula. Secondary oak forests became widely distributed in the 20th century due to intensive human activities.
Reactive oxygen species (ROS) are by-products of normal cell activity. They are produced in many cellular compartments and play a major role in signaling pathways. Overproduction of ROS is associated ...with the development of various human diseases (including cancer, cardiovascular, neurodegenerative, and metabolic disorders), inflammation, and aging. Tumors continuously generate ROS at increased levels that have a dual role in their development. Oxidative stress can promote tumor initiation, progression, and resistance to therapy through DNA damage, leading to the accumulation of mutations and genome instability, as well as reprogramming cell metabolism and signaling. On the contrary, elevated ROS levels can induce tumor cell death. This review covers the current data on the mechanisms of ROS generation and existing antioxidant systems balancing the redox state in mammalian cells that can also be related to tumors.
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•The paper presents a new high-resolution data of landscape changes in last 7.5 ka.•The work is focused on environment response to climate, sea level changes and fires.•The ...reconstructions were based on the multiproxy data (diatom, pollen, 14C-dating).•Strong floods and tsunamis are factors influencing coastal landscape dynamic.
Several stages are recognizable in landscape evolution along the Eastern Primorye coast, Kit Bay and its surrounding mountains in terms of climatic changes and related sea level fluctuations during the middle–late Holocene. The last 3.8–3.5 cal ka years were marked by a notable effect of the pyrogenic factor. The sea level rise at the maximum phase of the Holocene transgression led to the formation of lagoons at stream mouths, which underwent a complicated development. At that time, the coast’s principal topographic elements came into being, and the modern landscape’s pattern was laid on the coastal lowlands. The authors trace the changes in the vegetation in the process of short-term warmings and coolings. Korean pine appeared in the forests surrounding Kit Bay much earlier than in other regions of the Eastern Primorye. During the considered period, warmer phases were marked by increasing importance of broadleaf species, while at the cooler phases, a proportion of the Korean pine grew in the low mountains. In the last 2.3 cal ka, at greater elevations in the middle mountains, dark coniferous forests became more widespread, particularly spruce. At the same time, larch groves existed around the coastal sphagnum bog, probably due to seasonally frozen ground persisting for the greater part of a year. Extreme events with a considerable effect on the coastal landscape evolution include floods, whose frequency has been growing for the last 1.75 cal ka. Strong tsunamis are another factor influencing coastal evolution. Finally, changes in landscapes have been recorded related to human activities in the last few decades.
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