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Using circulating fluidized bed combustion (CFBC) ash discharged from thermal power plants, we identified factors affecting mineral carbonation to sequester CO2 and produced autoclaved aerated concrete (AAC). To use CFBC ash as a raw material for AAC, free-CaO, which causes volume expansion, was replaced through hydration and carbonation. During the raw material replacement process, carbonation behavior was confirmed through pH and temperature. A Ca(OH)2 to liquid ratio similar to a fly ash to liquid ratio of 0.25 is considered to provide sufficient diffusion distance, and the reaction rate may increase due to the rise in water temperature caused by Ca2+ leaching. Additionally, the results of XRD, XRF, TG-DTA, and SEM analyses indicate that hydration and carbonation reactions were stably achieved in the materials, suggesting that CO2 sequestration allows the materials to be used as alternative raw materials. After identifying the characteristics of the CFBC ash and the substituted material, AAC was manufactured through pressurized carbonation. The weight change rate, carbonation depth, ventilation rate, pore structure, and compressive strength of the manufactured AAC were measured. As a result, the alternative raw material exhibited higher permeability and a larger pore size range in the specimens compared to the original material, indicating easier CO2 penetration into the specimens. Consequently, this experiment suggests the potential of using the material in AAC production by providing a theoretical basis for solving volume expansion issues associated with concrete admixtures and CO2 sequestration in waste materials. [ABSTRACT FROM AUTHOR]

Fullerene is a cosmic material with a buckyball-like structure comprising 60 carbon atoms. It has attracted significant interest because of its outstanding antioxidant, antiviral, and antibacterial properties. Natural fullerene (NC60) in shungite meets the demand of biomedical fields to scavenge reactive oxygen species in many diseases. However, its hydrophobicity and poor solubility in water hinder its use as an antioxidant. In this study, highly water-dispersed and stable Pluronic-coated natural fullerene nanoaggregates (NC60/Plu) were prepared from various Pluronic polymers. The water dispersity and stability of NC60 were compared and optimized based on the characteristics of Pluronic polymers including F68, F127, L35, P123, and L81. In particular, NC60 coated with Pluronic F127 at a weight ratio of 1 to 5 showed excellent antioxidant effects both in situ and in vitro. This suggests that the high solubilization of NC60 in Pluronic polymers increases its chance of interacting with reactive oxygen radicals and improves radical scavenging activity. Thus, the optimized NC60/PF127 may be a novel biocompatible antioxidant for treating various diseases associated with oxidative stress. [ABSTRACT FROM AUTHOR]

Despite the inhibitory effect of phytoncide (Pht) on food-borne pathogenic bacterial growth, the hydrophobic nature and susceptibility to biodegradation under physiological conditions limits its applications. Here, we developed Pht-loaded polyvinylpyrrolidone (PVP) micelles (Pht@PVP MC) via micelle packing. Pht was solubilized using different types of PVP as micellar vehicles. The as-prepared Pht@PVP MCs were characterized using dynamic light scattering and transmission electron microscopy. The sizes of the Pht@PVP MCs were controlled from 301 ± 51 to 80 ± 3 nm by adjusting the PVP content. The polydispersity index of Pht@PVP MC was between 0.21 ± 0.03 and 0.16 ± 0.04, indicating homogeneous size. A colony-counting method was employed to evaluate the improvement in antibacterial activity after Pht encapsulation in PVP micelles. The reactive oxygen species (ROS)-scavenging activity and anti-inflammatory efficacy of Pht@PVP MC were analyzed in a concentration range of 10–100 μg/mL by evaluating in vitro ROS and nitric oxide levels using DCFDA and Griess reagents. PVP with both hydrophobic and hydrophilic moieties improved the aqueous solubility of Pht and stabilized it via steric hindrance. Higher-molecular-weight PVP at higher concentrations resulted in a smaller hydrodynamic diameter of Pht@PVP MC with uniform size distribution. The spherical Pht@PVP MC maintained its size and polydispersity index in a biological buffer for 2 weeks. Pht@PVP MC exhibited enhanced antibacterial activity compared to bare Pht. The growth of Staphylococcus aureus was effectively inhibited by Pht@PVP MC treatment. Furthermore, biocompatible Pht@PVP MC exhibited dose-dependent antioxidant and anti-inflammatory activities in vitro. Overall, Pht@PVP MC is an effective alternative to synthetic antibacterial, antioxidant, and anti-inflammatory chemicals. [ABSTRACT FROM AUTHOR]

Carbon acquisition and utilization are fundamental processes required for the growth and metabolism of algae, eukaryotic organisms that play a crucial role in global carbon cycling and contribute to the primary productivity of aquatic ecosystems. Algal cells rely on carbonic anhydrases (CAs) to facilitate the acquisition of inorganic carbon (Ci) and its conversion into bicarbonate ions (HCO3−) for various cellular processes. Understanding the molecular mechanisms that underlie Ci regulation is vital for unraveling the adaptation of algae to different CO2 conditions and enhancing the production of algal biomass. In this study, we characterized mutant algae showing robust growth under low CO2 conditions but impaired growth in high CO2 environments. Our investigation revealed a significant reduction in intracellular Ci content in the mutant, suggesting a disruption in Ci regulatory mechanisms. Through molecular analysis, we identified the pKIWI502 gene homolog as one of the mutated loci, which played a critical role in Ci regulation and was responsible for the mutant phenotype. Introduction of the intact pKIWI502 gene into mutant algae resulted in the recovery of high-CO2 sensitivity and the restoration of intracellular Ci content. These findings highlight the possible role of the pKIWI502 homolog in pH homeostasis and Ci regulation, and provide insights into the molecular basis of the mutant phenotype. Furthermore, our study improves the understanding of algal physiology and offers potential strategies for enhancing algal biomass production and carbon capture technologies. [ABSTRACT FROM AUTHOR]