Oxygen

Salt stress is a major agricultural issue. A promising modern agriculture method is the foliar treatment of zinc oxide nanoparticles (ZnONPs). This approach has shown promise in boosting challenged tomato yields, fruit quality, and leaf extract antibacterial activity against pathogens. A greenhouse experiment was conducted. The previously synthesized and characterized ZnONPs were used to alleviate the harmful effects of NaCl stress. Tomato fruit weight from different treatments was determined, and the gas–liquid chromatography device was used to observe the changes in fatty acid production. The antimicrobial activities of the aqueous and diethyl ether extracts from tomato leaves were determined against six bacterial and six fungal strains. The plants that were salinity-stressed and sprayed with 0.075 and 0.15 g/L ZnONPs showed a better improvement compared to the salinity-stressed plants. Also, the sprayed plants that were not stressed at all showed promising results compared to the control and the other different treatments. Through the process of molecular docking, it was shown that caffeic acid, ferulic acid, p-coumaric acid, sinapic acid, and apigenin-7-glucoside are essential chemicals that possess antibacterial and antifungal effects against the DNA Gyrase inhibitor and the sterol 14-alpha demethylase (CYP51) enzyme, respectively. It is concluded that salt stress can negatively affect the growth, quality, and variant plant features. However, the foliar application of ZnONPs is able to overcome those adverse effects in the stressed plants, and enhance the non-stressed as well.

Age-related macular degeneration (AMD) is an age-associated disease characterized by damage to the central retina and represents a leading cause of acquired blindness, with increasing prevalence in aging populations. However, effective therapeutic options remain limited. The accumulation of dysfunctional mitochondria in retinal pigment epithelial (RPE) cells leads to excessive production of reactive oxygen species (ROS), triggering cellular senescence and cell death that contribute to the pathogenesis of AMD. Therefore, removal of accumulated dysfunctional mitochondria in senescent RPE cells is expected to treat AMD. Herein, we investigated transferrin (Trf)-modified mitophagy-inducing dual-drug nanocarriers (Trf-M-NCs) for the treatment of a senescent RPE cell. To evaluate efficacy, we used sodium iodate-treated ARPE-19 cells. The Trf-M-NCs exhibited significantly higher uptake by ARPE-19 cells than the unmodified M-NCs. Importantly, Trf-M-NC treatment alleviated cellular senescence by restoring the mitochondrial functions. Furthermore, Trf-M-NC treatment not only restored the production of α-ketoglutarate, an essential energy source for photoreceptor cells, but also reduced the secretion of IL-6, a key inflammatory cytokine. These findings suggest that improving mitochondrial quality in RPE cells is a novel and promising therapeutic approach for AMD.

Background: During an apnea, oxygen depletion occurs at all tissue levels, so apnea duration is influenced by the mammalian dive reflex, which includes a bradycardia resulting in reduced cardiac oxygen consumption. This study aimed to examine the relationships between heart rate (HR), peripheral estimation of O₂ (SpO₂), deltoid and respiratory muscle oxygenation (SmO₂), and apnea duration. Methods: The study included 10 breath-hold divers (BHD), 39 ± 10 years of age, with body height of 184.3 ± 3.5 cm, body mass of 84.0 ± 9.2 kg, and 16.2 ± 9.7 years of apnea experience. The BHD performed three preparatory apneas followed by three maximal apneas with 5 min of supine rest between each apnea. During all apneas (duration, 115–323 s; involuntary breathing movements (IBMs), 7–35), SmO₂ (measured via NIRS on intercostals (respiratory) and deltoid (locomotor) muscles), heart rate, and SpO₂ (measured via forehead sensor) were obtained. Results: The smallest disagreement in oxygen levels was between intercostal SmO₂ and SpO₂ during the easy-going phase (no IBMs), whereas deltoid desaturation values were more variable. During the struggle phase, Intercostal SmO₂, moderately, and Deltoid SmO₂, strongly, differed from SpO₂. Correlations between apnea duration and O₂ saturation showed that only Intercostal SmO₂ (r = −0.71; p = 0.03) was significantly related to apnea duration. There was also a significant correlation between HR and SpO₂ in the struggle phase (r = −0.58; p = 0.05). Conclusions: These findings suggest that during the struggle phase, SpO₂ and SmO₂ are not highly connected and that local and systemic oxygen levels in the blood are depleted at different rates. Furthermore, the HR response during the struggle phase affected only SpO₂, which indicates that lowering the heart rate may help prevent more rapid deoxygenation. Lastly, the intercostal trend of deoxygenation could be interpreted as respiratory muscle work, suggesting that the increased work of respiratory muscles may prolong apnea duration.