Two novel membranes based on collagen and two polyphenols, taxifolin pentaglutarate (TfG5) and a conjugate of taxifolin with glyoxylic acid (DfTf), were prepared. Fourier transform infrared spectroscopy examination confirmed the preservation of the triple helical structure of collagen. A scanning electron microscopy study showed that both materials had a porous structure. The incorporation of DfTf into the freeze-dried collagen matrix increased the aggregation of collagen fibers to a higher extent than the incorporation of TfG5, resulting in a more compact structure of the material containing DfTf. It was found that NIH/3T3 mouse fibroblasts were attached to, and relatively evenly spread out on, the surface of both newly obtained membranes. In addition, it was shown that the membranes enhanced skin wound healing in rats with a chemical burn induced by acetic acid. The treatment with the materials led to a faster reepithelization and granulation tissue formation compared with the use of other agents (collagen without polyphenols and buffer saline). It was also found that, in the wound tissue, the level of thiobarbituric acid reactive substances (TBARS) was significantly higher and the level of low-molecular-weight SH-containing compounds (RSH) was significantly lower than those in healthy skin, indicating a rise in oxidative stress at the site of injury. The treatment with collagen membranes containing polyphenols significantly decreased the TBARS level and increased the RSH level, suggesting the antioxidant/anti-inflammatory effect of the materials. The membrane containing TfG5 was more effective than other ones (the collagen membrane containing DfTf and collagen without polyphenols). On the whole, the data obtained indicate that collagen materials containing DfTf and TfG5 have potential as powerful therapeutic agents for the treatment of burn wounds.

Arabidopsis thaliana plants of two mutant lines with a knockout of the At3g52720 gene, encoding stromal α-carbonic anhydrase 1, αCA1 (αCA1-KO), and wild-type plants of the Columbia ecotype (Col), were grown under 450 ppm (NCO₂) and 150 ppm (LCO₂) CO₂ in the air. The CO₂ assimilation rate (ACO₂) in plants grown under NCO₂ was lower in the αCA1-KO plants than in Col plants at CO₂ concentrations from 600 to 1200 ppm in the measurement chamber. In LCO₂-grown plants, ACO₂ values were lower than in NCO₂-grown plants both in Col and mutants, with the same values in mutants and Col. Water use efficiency (WUE) in NCO₂-grown mutant plants was lower than in Col at a CO₂ concentration of 600 ppm and above, and in LCO₂-grown mutants WUE became lower than in Col at 1200 ppm. The starch content was lower in leaves of mutants than in Col under both NCO₂ and LCO₂ conditions due to its reduced synthesis during the daytime photosynthesis. Under NCO₂, the content of hydrogen peroxide was 55% higher in αCA1-KO plant leaves than in Col. Under LCO₂, the content of H₂O₂ in Col increased to more than three times its level under NCO₂, and became 2.5 times higher than in αCA1-KO, in which it decreased by 34% compared to that in NCO₂ plants. Under NCO₂ conditions, the contents of the stromal, cytosolic, and peroxisomal forms of ascorbate peroxidases (APXs) were about twice higher in αCA1-KO than in Col plants. Contrariwise, in LCO₂-grown plants the contents of APXs were lower in mutants than in Col. The total protein amount, as well as the level of ribulose-1,5-bisphosphate carboxylase/oxygenase, were the same in Col and mutants under NCO₂ conditions, but were 35% and 45–50%, respectively, lower in αCA1-KO than in Col under LCO₂ conditions. In the leaves of NCO₂-grown plants, the stomatal conductance was higher in αCA1-KO than in Col with slower stomatal opening and delayed closure in response to decreases and increases in CO₂ level, respectively. At the same time, in the absence of αCA1, both the total number of stomata per unit leaf surface area, and the relative number of open stomata were higher than in Col leaves. In the protoplasts isolated from NCO₂-grown αCA1-KO plants, the steady-state rates of oxygen evolution were 30% lower in mutants than in Col and were reached at a lower HCO₃⁻ concentration (5 mM) than in protoplasts from Col (8 mM). The apparent half-saturating bicarbonate concentration was approximately 2 mM for αCA1-KO and 4 mM for Col. Our data demonstrate the involvement of the stromal chloroplast αCA1 in providing A. thaliana cells with CO₂, and imply the significance of αCA1 in supplying inorganic carbon for starch and protein synthesis in plants. The increase in the total number of stomata per unit of leaf surface area and in the relative proportion of open stomata, as well as the reduced rate of stomatal responses in plants lacking αCA1, suggests the possible involvement of this enzyme in signaling processes regulating both stomatal movement and development.

This article examines the anthropogenic contribution to the planet’s climate system due to thermal pollution. Despite the quantitative predominance of solar and geothermal energy in the Earth’s heat balance, anthropogenic heat impacts the planet’s most sensitive shell - the biosphere. Thermal pollution in various countries has been assessed based on specific (per unit area) energy consumption, as all energy consumed by humanity is ultimately converted into heat and released into the biosphere. Specific carbon dioxide emissions also serve as an indirect indicator (marker) of thermal pollution, as fossil fuels remain the primary energy source. Calculated correlation coefficients between thermal pollution indicators (specific energy consumption and CO2 emissions) and climate warming in various regions have revealed a low positive correlation between these indicators (0.17-0.13, respectively), which indicates thermal pollution’s contribution to global warming to be still insignificant. Thus, the current contribution of anthropogenic heat to the climate system is primarily regional, which is undoubtedly important to consider in environmental policy to prevent the negative impact of this factor on the functioning of natural ecosystems. This is especially important in the context of global warming, primarily caused by natural factors.

Arabidopsis thaliana plants of two mutant lines with knocked out the At3g52720 gene, encoding stromal α-carbonic anhydrase 1, αCA1 (αCA1-KO), and wild-type plants, of the Columbia ecotype (Col), were grown under 450 ppm (NCO₂) and 150 ppm (LCO₂) CO₂ in the air. The CO₂ assimilation rate (ACO₂) in plants grown under NCO₂ was lower in the αCA1-KO plants than in Col plants at CO₂ concentrations from 600 to 1200 ppm in the measurement chamber. In LCO₂-grown plants, ACO₂ values were lower than in NCO₂-grown plants both in Col and mutants, with the same values in mutants and Col. Water use efficiency (WUE) in NCO₂ grown mutant plants was lower than in Col at a CO₂ concentration of 600 ppm and above, and in LCO₂-grown mutants WUE became lower than in Col at 1200 ppm. The starch content was lower in leaves of mutants than in Col under both NCO₂ and LCO₂ conditions due to its reduced synthesis during the daytime photosynthesis. Under NCO₂, the content of hydrogen peroxide was twice higher in αCA1‑KO plant leaves than in Col. Under LCO₂, the content of Н₂О₂ in Col increased to more than three times its level under NCO₂, and became 2.5 times higher than in αCA1‑KO, in which it decreased by 1.5 times compared to that in NCO₂ plants. Under NCO₂ conditions, the contents of the stromal, cytoplasmic and peroxisomal forms of ascorbate peroxidases (APXs) were about twice higher in αCA1-KO than in Col plants. Contrariwise, in LCO₂-grown plants the contents of APXs were lower in mutants than in Col. The total protein amount, as well as the level of ribulose-1,5-bisphosphate carboxylase/oxygenase, were the same in Col and mutants under NCO₂ conditions, but were 35% and 45-50%, respectively, lower in αCA1-KO than in Col under LCO₂ conditions. In the leaves of NCO₂-grown plants, the stomatal conductance was higher in αCA1-KO than in Col with slower stomatal opening and delayed closure in response to decreases and increases in CO₂ level, respectively. At the same time, in the absence of αCA1, both the total number of stomata per unit leaf surface area, and the relative number of open stomata were higher than in Col leaves. In the protoplasts isolated from NCO₂-grown αCA1-KO plants, the steady-state rates of oxygen evolution were 30 % lower in mutants than in Col and were reached at a lower HCO₃¯ concentration (5 mM) than in protoplasts from Col (8 mM). The apparent half-saturating bicarbonate concentration was approximately 2 mM for αCA1-KO and 3 mM for Col. Our data demonstrate the involvement of the stromal chloroplast αCA1 in providing A. thaliana cells with CO₂, the importance of this enzyme for starch synthesis, as well as the significance of αCA1 for protein synthesis in plants. The increase in the total number of stomata per unit of leaf surface area and in the relative proportion of open stomata, as well as the reduced rate of stomatal responses in plants lacking αCA1, suggests the possible involvement of this enzyme in signaling processes regulating both stomatal movement and development.