Formation Of Structure Research Articles

The formation of lamellar body-like structures may be a trigger of cetylpyridinium chloride-induced cell death and inflammatory response

Cetylpyridinium chloride (CPC) is a quaternary ammonium compound used widely in health and personal care products. Meanwhile, due to its increasing use, its potential adverse health effects are emerging as a topic of public concern. In this study, we first administered CPC by pharyngeal aspiration to determine the survival level (the maximum concentration at which no death is observed) and then administered CPC to mice repeatedly for 28 days using the survival level as the highest concentration. CPC increased the total number of pulmonary cells secreting pro- and anti-inflammatory cytokines and chemokines. Infiltration of inflammatory cells, production of foamy alveolar macrophages, and chronic inflammatory lesions were found in the lung tissue of male and female mice exposed to the highest dose of CPC. We also investigated the toxicity mechanism using BEAS-2B cells isolated from normal human bronchial epithelium. At 6h after exposure to CPC, the cells underwent non-apoptotic cell death, especially at concentrations greater than 2μg/mL. The expression of the transferrin receptor was remarkably enhanced, and the expression of proteins that contribute to intracellular iron storage was inhibited. The expression of both mitochondrial SOD and catalase increased with CPC concentration, and PARP protein was cleaved, suggesting possible DNA damage. In addition, the internal structure of mitochondria was disrupted, and fusion between damaged organelles was observed in the cytoplasm. Most importantly, lamellar body-like structures and autophagosome-like vacuoles were found in CPC-treated cells, with enhanced expression of ABCA3 protein, a marker for lamellar body, and a docking score between ABCA3 protein and CPC was considered to be approximately -6.8969kcal/mol. From these results, we propose that mitochondrial damage and iron depletion may contribute to CPC-induced non-apoptotic cell death and that pulmonary accumulation of cell debris may be closely associated with the inflammatory response. Furthermore, we hypothesize that the formation of lamellar body-like structures may be a trigger for CPC-induced cell death.

Observability of CMB spectrum distortions from dark matter annihilation

Even after dark matter chemically freezes out in the early universe, electromagnetic cascades from dark matter annihilation can still perturb the background photon spectrum when the universe temperature cools down to 0.5 keV. We revisit the CMB spectrum distortions caused by s-wave dark matter annihilation under the updated Planck data and the future CMB sensitivity, concluding that s-wave annihilation cannot create observable distortions under forecast sensitivities of the (Super-)PIXIE missions. We further detail the case of p-wave dark matter annihilation, demonstrating the observability of the primordial μ-distortion. Taking current constraints from primordial light elements, structure formations, cosmic electron-positron rays, and gamma rays, we find that the μ-distortion reaching the observational limit as large as μ ≃ 3 × 10-8 can only be realized with a dark matter mass at 10–50 MeV and a kinetic decoupling temperature around 1 keV. The upper bound of the p-wave annihilation cross section can be strengthened by an order of magnitude if the μ-distortion is not detected.

Structural forming of soil composites using as a pavement subgrade strengthening

The article substantiates the possibility of obtaining composite materials with improved functional properties to strengthen the subgrade, containing technogenic soil stabilized by an additive based on a gelling polymer. The introduction of technogenic soils into composites will not only reduce the consumption of expensive materials, but also solve a complex of acute environmental problems. Composite materials can be used in the construction of structural layers of road pavements, foundations of buildings and structures, sites for various purposes, for the prevention and elimination of defects in the foundations of engineering structures during their construction, reconstruction and repair, including in permafrost areas. Stabilized technogenic soils are more durable, frost-resistant and waterproof, which makes them applicable for creating impervious curtains in hydraulic structures and sealing storage facilities for hazardous substances. The cryogenic effect on a composite material allows one to vary its properties within a wide range and modify its macroporous structure. Studying the process of structure formation of the resulting organic-inorganic materials, consisting of macromolecules of high-molecular substances and inorganic inclusions that have undergone cryogenic treatment, will make it possible to specifically regulate their performance characteristics. The best values of strength characteristics were obtained for samples with a stabilizing additive concentration of 100g/l. The resulting composite materials are hydrophobic, frost-resistant, characterized by a compressive strength of 2.3-6.5MPa and a thermal conductivity of 0.19-0.20W/(m·K). Data from differential scanning calorimetry and thermogravimetry and IR spectroscopy revealed that the binding of mineral particles by a stabilizing additive occurs due to the formation of organomineral complexes with the participation of clay minerals and the restructuring of hydration shells. SEM data indicate that crystallinity zones formed due to hydrogen bonds of hydroxyl groups of neighboring polymer chains can participate in the formation of the composite structure. An increase in the number of cryogenic treatment cycles promotes additional structuring and strengthening of the polymer phase due to the formation of additional nodes of the supramolecular network, ordering of crystallinity zones and the appearance of compacted areas in the structure. Computed X-ray tomography revealed an increase in the density of the composite upon drying, which helps to increase its strength characteristics. The structure of the sample is characterized by heterogeneity of the pore space, which is characterized by the presence of both fine-porous and large-porous regions, which determines its thermophysical properties.

Electrochemical chiral sensor developed using nanofibrous polyaniline chiral Structures: Detection and differentiation of D- and l-tryptophan

In this work, a simple strategy for electrochemical detection and differentiation of D- and L- forms of tryptophan is demonstrated using nanofibrous structures of chiral polyaniline (CP). Basically, CP with desired chirality is prepared using a chiral acid namely, ± camphor sulfonic acid (±CSA) in presence of either a cationic (or) anionic surfactant (CTAB / SDS) through a simple oxidative polymerization process. Structure, morphology and phase purity of the resultant CP materials are characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray diffraction studies. Moreover, the chiral properties of these conducting polymers are evaluated using circular dichroism (CD) spectroscopic studies. From these analyses it is found that CP exhibited twisted nanofibrous morphology and possesses the chirality whereas the non-chiral polyaniline (PANI), prepared in the absence of chiral acid, displayed the formation of a simple fibrous structures without any twists or chirality. Interestingly, such CP materials are found to be electrochemically selective for the detection and differentiation of D- and L- forms of tryptophan (Trp). Among the different chiral materials, CP-CT(−) prepared using CTAB displayed a much better sensing characteristics with higher IL/ID ratio, wider concentration range of detection and lower detection limit of 0.98 µM for l-Trp and 1.2 µM for d-Trp respectively. On the other hand, non-chiral PANI does not display any sensing behavior towards the differentiation of amino acid, Trp. Further, chronoamperometric studies reveal the selectivity of this chiral sensor for the detection of Trp among the other potentially interfering analytes. Although the difference in the measured peak current value is smaller, a significant difference of 70 mV peak potential is observed for the differentiation of L- and d-Trp. Moreover, the proposed CP-based sensing platform exhibits excellent stability and reproducibility with statistically negligible error values suggesting the potential use of the developed material towards electrochemical chiral detection and differentiation of amino acid, Trp.

Insights into the formation and growth of high entropy PdPtSnPbNi nanowires to obtain catalysts with high alcohol electrocatalytic oxidation activity

High-entropy alloys have raised great interest in recent years because of their potential applications for multi-electron reactions owing to their diverse active sites and multielement tunability. However, the difficulty of synthesis is an obstacle to their development due to phase separation often exists. In addition, it’s a challenge to precisely control morphology in harsh conditions, thus leading to nanoparticles in many cases. We report a facile method to obtain PdPtPbSnNi HEA NWs by solvothermal synthesis method that no existing phase separation. PdPb nucleation plays a role in the formation of the high-entropy structure that serves as a PdPb nucleus for Sn, Ni, and Pt reduction subsequently, thus forming a single phase and an orderly-arranged nanowire structure. Significantly, the optimized PdPtPbSnNi NWs exhibit excellent catalytic activity and stability for both EOR and MOR which is 4.36 A mgPd+Pt-1 and 4.34 A mgPd+Pt-1, respectively. This study highlights a novel strategy for morphology tuning, providing a prospect for designing superior high-entropy nano-catalysts for multi-step reactions.

Large eddy simulation of shock wave/boundary layer interactions in a transonic compressor cascade

In this paper, large eddy simulation (LES) was performed to investigate the shock wave/boundary layer interaction (SBLI) phenomenon in transonic compressor cascades with a chord Reynolds number of 2.12 × 106. A comprehensive analysis was conducted on both the SBLI structures inherent to the transonic compressor cascade and the coherent vortex structures within the boundary layer. The underlying mechanisms of the shock-induced boundary layer transition and the shock low-frequency unsteadiness in the transonic compressor cascade were elucidated through spectral and dynamic mode decomposition (DMD) analysis. The results revealed that boundary layer separation induced by the SBLI cannot reattach, leading to the formation of large-scale coherent vortex structures. Spectral analysis revealed that the shock-induced boundary layer transition in the transonic compressor cascade was dominated by inviscid Kelvin–Helmholtz (K–H) and secondary instability mechanisms, characterized by a dimensionless Strouhal number of 0.06. Additionally, pressure signals showed the variations in sub-frequency from the separated shear layer to the main flow. The oscillation amplitude of the shock foot was significantly greater than that of the shock main body, and the oscillation frequency of the shock foot was consistent with the sub-frequency. The oscillation frequency of the shock main body coincided with that of the compression ramp and flat plate configurations. Finally, DMD modal analysis indicated that high-frequency modes were correlated with turbulent fluctuations in the boundary layer, while medium- and low-frequency modes corresponded to shedding motion in the separated shear layer and low-frequency motion of the shock. This work promotes the understanding of the complex flow mechanisms of SBLI in the transonic compressor cascades.

Wedge-Shape Al and Mg Co-doped Zinc Oxide Thin Films: A Facile Route to Achieve High Thermoelectric Power Factor

Thin film thermoelectric technology has immense potential to become a next-generation power source for small-scale electronics. However, the rapid development of thin film thermoelectric still lacks a controllable structural design to improve the performance of thermoelectric devices for required temperature applications. This work presented a controlled thermoelectric design of ZnO-based thin films by Al and Mg co-doping using ALD. Herein, the Mg-doped ZnO sample exhibits the highest Seebeck coefficient of -311.83 μVK-1 at 500oC, while the maximum thermoelectric power factor of 3.68 μWcm-1K-2 is obtained at 300oC, which drops for higher temperatures. This decrease in power factor resulted from the reduction in electrical conductivity above 300oC. Similarly, the Al and Mg co-doped ZnO sample (Mg/Al ≈2 at%) exhibits a high thermoelectric power factor of 3.85 μWcm-1K-2 for ZnO based material due to its moderate electrical conductivity and Seebeck coefficient value at 325oC and behave monotonically for elevated temperatures. Scanning electron microscope (SEM) images show the formation of wedge-shaped structures for Al-incorporated samples, which helps to boost the overall thermoelectric performance. Additionally, we performed XRD, UV-Vis, Hall, and AFM analysis to get a deep insight into structural, optical, electrical, and surface features of the grown thin films and their linkage with the thermoelectric properties.

Hardness fluctuations caused by annealing in Zr-based bulk metallic glasses via nanoindentation

The micromechanical response of a Zr-based bulk metallic glass (BMG) annealed in air below and above its glass transition temperature was studied. Nano-sized particles in different states at different annealing temperatures were found on the surface of the samples, which were identified by energy-dispersive spectroscopy (EDS) as being CuNi elemental composition. The surface microhardness and nanoindentation creep behavior of the BMGs after annealed exhibited interesting results, at low annealing temperatures, the microhardness of the samples showed softening accompanied by poor creep resistance, while at high annealing temperatures, the hardness of the samples shows hardening and creep resistance was enhanced. The consequences of such a temperature-dependent dichotomy were intricately linked to element segregation, which led to microstructural fluctuations. A competing mechanism between the hardening effect of zirconia at the surface and the softening effect of elemental segregation in the formation of microporous structures inside the samples is proposed to account for the divergent mechanical properties due to the annealing temperature. This work presents helpful insights into microstructural changes and micromechanical properties of BMGs during annealing, as well as an experimental support for structural and property modulation of BMGs.

Phosphatidylethanolamines link ferroptosis and autophagy during appressorium formation of rice blast fungus.

A cell death pathway, ferroptosis, occurs in conidial cells and is critical for formation and function of the infection structure, the appressorium, in the rice blast fungus Magnaporthe oryzae. In this study, we identified an orthologous lysophosphatidic acid acyltransferase (Lpaat) acting at upstream of phosphatidylethanolamines (PEs) biosynthesis and which is required for such fungal ferroptosis and pathogenicity. Two PE species, DOPE and SLPE, that depend on Lpaat function for production were sufficient for induction of lipid peroxidation and the consequent ferroptosis, thus positively regulating fungal pathogenicity. On the other hand, both DOPE and SLPE positively regulated autophagy. Loss of the LPAAT gene led to a decrease in the lipidated form of the autophagy protein Atg8, which is probably responsible for the autophagy defect of the lpaatΔ mutant. GFP-Lpaat was mostly localized on the membrane of lipid droplets (LDs) that were stained by the fluorescent dye monodansylpentane (MDH), suggesting that LDs serve as a source of lipids for membrane PE biosynthesis and probably as a membrane source of autophagosome. Overall, our results reveal novel intracellular membrane-bound organelle dynamics based on Lpaat-mediated lipid metabolism, providing a temporal and spatial link of ferroptosis and autophagy.

High-performance zinc-ion hydrogel electrolytes based on molecular-level hybridization of PVA with polymer quantum dots

Aqueous zinc ion batteries have received widespread attention. However, the growth of zinc dendrites and hydrogen evolution reaction generation seriously hinder the practical application of zinc ion batteries. Herein, it is reported that a multifunctional dendrites-free low-temperature PVA-based gel electrolyte by introducing negatively charged polymer carbon quantum dots (QDs) and the organic antifreeze dimethyl sulfoxide (DMSO) into it. The QDs carrying a large number of functional groups on the surface can effectively adsorb Zn2+, eliminating the “tip effect”, and inducing the uniform deposition of Zn2+ and the formation of a dendrites-free structure. Meanwhile, the solvation structure of adsorbed Zn2+ can be controlled by charged groups to reduce the generation of side reactions, thus obtaining high-performance zinc ion batteries. The Zn/polyaniline (PANi) full battery can be stably cycled more than 1000 times at –20 °C, and the design of this gel electrolyte can provide good feasibility for safe, stable, and flexible energy storage devices.

Interdiffusion mechanism of hybrid interfacial layers for enhanced electrical resistivity and ultralow loss in Fe-based nanocrystalline soft magnetic composites

Soft magnetic composites (SMCs) composed of ferromagnetic particles and insulating binder are highly desired in energy-saving and high-efficiency devices for their high electrical resistivity and softer saturation characteristics. However, traditional insulation coatings are facing thermal instability, inhomogeneous distribution, and magnetic dilution, presenting a major challenge for the trade-off relationship between power loss and permeability. Here, the phosphate-coated FeSiBCuNb/SiO2 SMC is successfully fabricated by a unique interdiffusion effect in hybrid interfacial layers, which shows a combination of ultralow power loss of 135.8 kW/m3 (50 kHz/100 mT), high effective permeability of 80.6, and good temperature stability. The interdiffusion behavior between Si/O and Fe/P/O elements promotes the formation of ultrathin, uniform, and multilayer interface structure, which alleviates the magnetic dilution. Penetrating oxidation at the edge interface and elements interdiffusion effect contribute to a higher electrical resistivity induced by hot isostatic pressing with rapid quenching, leading to a low eddy current loss. Synergistic effect of isostatic pressures and rapid quenching facilitates the formation of high-density Cu clusters corresponding to ultrafine microstructure, which is beneficial for low coercivity and low hysteresis loss. This study involves the interdiffusion mechanism of hybrid interfacial layers and nanocrystalline behavior, providing a new strategy for the next-generation of high-performance SMCs.

Preparation of ZnNi/CNT composite structures and their catalytic application in Li/CFx battery

Li/CFx batteries play a crucial role in cutting-edge fields such as military and medical applications. However, they still need further research to enhance their low discharge voltage with improved discharge capacity. In this work, ZnNi/CNT composites were used as catalysts to promote performance of Li/CFx batteries. Results show that these composites could enhance the battery to exhibit high specific capacity with improved voltage platform. Further analysis finds that a higher ion diffusion coefficient at 0.1C discharge was maintained with lower charge transfer impedance. Ex-situ test results further reveal the ZnNi/CNT could lead to the formation of smaller LiF structure after discharge process, which is crucial for promoting the electrochemical process of Li/CFx battery. This work could provide an important reference for the design of primary battery electrode structure.

Light-curve Structure and Hα Line Formation in the Tidal Disruption Event AT 2019azh

AT 2019azh is a H+He tidal disruption event (TDE) with one of the most extensive ultraviolet and optical data sets available to date. We present our photometric and spectroscopic observations of this event starting several weeks before and out to approximately 2 yr after the g-band's peak brightness and combine them with public photometric data. This extensive data set robustly reveals a change in the light-curve slope and a possible bump in the rising light curve of a TDE for the first time, which may indicate more than one dominant emission mechanism contributing to the pre-peak light curve. Indeed, we find that the MOSFiT-derived parameters of AT 2019azh, which assume reprocessed accretion as the sole source of emission, are not entirely self-consistent. We further confirm the relation seen in previous TDEs whereby the redder emission peaks later than the bluer emission. The post-peak bolometric light curve of AT 2019azh is better described by an exponential decline than by the canonical t −5/3 (and in fact any) power-law decline. We find a possible mid-infrared excess around the peak optical luminosity, but cannot determine its origin. In addition, we provide the earliest measurements of the Hα emission-line evolution and find no significant time delay between the peak of the V-band light curve and that of the Hα luminosity. These results can be used to constrain future models of TDE line formation and emission mechanisms in general. More pre-peak 1–2 days cadence observations of TDEs are required to determine whether the characteristics observed here are common among TDEs. More importantly, detailed emission models are needed to fully exploit such observations for understanding the emission physics of TDEs.

Structural Insights into Ciona intestinalis Septins: Complexes Suggest a Mechanism for Nucleotide-dependent Interfacial Cross-talk

Septins are filamentous nucleotide-binding proteins which can associate with membranes in a curvature-dependent manner leading to structural remodelling and barrier formation. Ciona intestinalis, a model for exploring the development and evolution of the chordate lineage, has only four septin-coding genes within its genome. These represent orthologues of the four classical mammalian subgroups, making it a minimalist non-redundant model for studying the modular assembly of septins into linear oligomers and thereby filamentous polymers. Here, we show that C. intestinalis septins present a similar biochemistry to their human orthologues and also provide the cryo-EM structures of an octamer, a hexamer and a tetrameric sub-complex. The octamer, which has the canonical arrangement (2-6-7-9-9-7-6-2) clearly shows an exposed NC-interface at its termini enabling copolymerization with hexamers into mixed filaments. Indeed, only combinations of septins which had CiSEPT2 occupying the terminal position were able to assemble into filaments via NC-interface association. The CiSEPT7-CiSEPT9 tetramer is the smallest septin particle to be solved by Cryo-EM to date and its good resolution (2.7 Å) provides a well-defined view of the central NC-interface. On the other hand, the CiSEPT7-CiSEPT9 G-interface shows signs of fragility permitting toggling between hexamers and octamers, similar to that seen in human septins but not in yeast. The new structures provide insights concerning the molecular mechanism for cross-talk between adjacent interfaces. This indicates that C. intestinalis may represent a valuable tool for future studies, fulfilling the requirements of a complete but simpler system to understand the mechanisms behind the assembly and dynamics of septin filaments.

Kazakhstan dairy market: guidelines for optimization

Milk plays an important role in human life as obligatory and necessary food product, containing the most valuable and easily digestible proteins, fats, carbohydrates, and minerals. The goal is to show the current state of dairy industry in Kazakhstan, factors influencing its development. The economic parameters of production of milk and dairy products, dynamics of production volumes, and the number of cattle by type of management have been studied. The methods are based on the study of domestic and analytical reviews, scientific publications, and statistical information. Results – there is a shortage of raw materials for processing enterprises, their low quality, and a large number of small producers. The authors state that homemade milk from private farms does not meet technological standards, which, in turn, is the reason for poorquality industrial processing of raw materials. Domestic producers satisfy the need only for liquid processed milk and cream (94.9%). Conclusions – indicators that have restraining effect on development of dairy industry in the republic are considered, the need for technological reequipment, formation of cluster structures, and state support for Kazakh producers is pointed out. Compliance with raw milk quality standards is only possible when using the latest methods for obtaining and primary processing of raw milk. To achieve an effect, subsidies for technical equipment are required, especially for small-scale farms (milking and refrigeration machines, disinfectants, express control analyzers, etc.). Forecasts for consumption of dairy products assume the ability to determine in the future the volumes and structure of market demand for this type of product. The fundamental factors are the level of income, trends in changes in retail prices, degree of market saturation, national and historical traditions.

Surface Morphology and Formation of Nanocrystals in an Amorphous Zr55Cu30Al10Ni5 Alloy under High-Pressure Torsion

A change in the structure of an amorphous Zr55Cu30Al10Ni5 alloy under deformation by high-pressure torsion (HPT) was studied by X-ray diffraction, high-resolution electron microscopy, scanning electron microscopy, and atomic force microscopy. It was found that the uneven distribution of deformation along the radius of the sample, characteristic of deformation by high-pressure torsion, led to the formation of an inhomogeneous structure. The formation of nanocrystals begins at the periphery of the sample. The threshold value of deformation required for crystallization onset was established; the formation of nanocrystals begins in areas with true deformation e = 4.83 or more. An increase in the deformation degree led to an increase in the height of steps on the deformed sample surface and an increase in the roughness of the surface. The thickness of an elementary step that was formed when one shear band came out to the surface was 10 nm, and its height was about 1 nm. It was found that large steps on the deformed surface of the sample had a complex structure and consisted of a large number of elementary steps. The results obtained are important for analyzing the stress distribution and the concentration of free volume in a deformed material, which affect the parameters of the amorphous-nanocrystalline structure formed.

Методика дослідження зародження кристалів у розплавах краплинним методом

The purpose of this work is to develop scientifically based ways of influencing the process of nucleation of crystallization centers in metal melts to control the formation of the cast structure and the properties of their blanks at the first stage of metal product production (at the casting stage). The possibility of controlling the nucleation of crystals in their melts was studied on transparent model environment (paraffin and salol) using the drop method, and the dependence of the crystallization kinetics of droplets with a dispersion of 100÷200 μm on their overheating temperature, the duration of exposure in an overheated state, and the degree of supercooling was established. Physical modeling on transparent environment made it possible to display images on a laptop screen with the help of a digital camera mounted on a microscope and to observe the nucleation and growth of crystals in real time, to determine the duration of solidification of all observed drops, depending on the experimental conditions. The criteria for evaluating the crystallization process of the investigated environment were the curves of the crystallization kinetics of drops from their melts. The nature of the change in the crystallization kinetics curves of the experimental environment, in our opinion, confirms the assumption about the decisive role of impurities in the crystallization processes of any alloys. The logical confirmation of the hypothesis about the decisive role of impurities in the processes of crystallization from the same positions of heterogeneous nucleation is the dependence of the number of solidified drops of experimental environment of the same diameter on the degree and duration of their overheating. It is likely that with greater overheating of the melt (or longer exposure to this overheating), partial deactivation (dissolution) of the impurities present occurs and the number of solidifying drops changes for the same supercooling. The analysis of the obtained results indicates a heterogeneous mechanism of crystal nucleation even in drops of microscopic size (~100 μm). The developed method of studying the processes of nucleation and growth of crystals in model alloys depending on their mass (size) can be applied in real conditions of mass crystallization. Keywords: model environment, droplet method, crystal nucleation, crystallization kinetics.

Study of structure formation of transparent spinel-containing glass-ceramic materials for laser techniques

Study of structure formation of transparent spinel-containing glass-ceramic materials for laser techniques

Research on the Interaction Mechanisms between ScCO2 and Low-Rank/High-Rank Coal with the ReaxFF-MD Force Field

CO2 geological sequestration in coal seams can be carried out to achieve the dual objectives of CO2 emission reduction and enhanced coalbed methane production, making it a highly promising carbon capture and storage technology. However, the injection of CO2 into coal reservoirs in the form of supercritical fluid (ScCO2) leads to complex physicochemical reactions with the coal seam, altering the properties of the coal reservoir and impacting the effectiveness of CO2 sequestration and methane production enhancement. In this paper, theoretical calculations based on ReaxFF-MD were conducted to study the interaction mechanism between ScCO2 and the macromolecular structures of both low-rank and high-rank coal, to address the limitations of experimental methods. The reaction of ScCO2 with low-rank coal and high-rank coal exhibited significant differences. At the swelling stage, the low-rank coal experienced a decrease in aromatic structure and aliphatic structure, and high-rank coal showed an increase in aromatic structure and a decrease in aliphatic structure, while the swelling phenomenon was more pronounced in high-rank coal. At the dissolution stage, low-rank coal was initially decomposed into two secondary molecular fragments, and then these recombined to form a new molecular structure; the aromatic structure increased and the aliphatic structure decreased. In contrast, high-rank coal showed the occurrence of stretches–breakage–movement–reconnection, a reduction in aromatic structure, and an increase in aliphatic structure. The primary reasons for these variations lie in the distinct molecular structure compositions and the properties of ScCO2, leading to different reaction pathways of the functional group and aromatic structure. The reaction pathways of functional groups and aromatic structures in coal can be summarized as follows: the breakage of the O–H bond in hydroxyl groups, the breakage of the C–OH bond in carboxyl groups, the transformation of aliphatic structures into smaller hydrocarbon compounds or the formation of long-chain alkenes, and various pathways involving the breakage, rearrangement, and recombination of aromatic structures. In low-rank coal, there is a higher abundance of oxygen-containing functional groups and aliphatic structures. The breakage of O–H and C–OH chemical bonds results in the formation of free radical ions, while some aliphatic structures detach to produce hydrocarbons. Additionally, some of these aliphatic structures combine with carbonyl groups and free radical ions to generate new aromatic structures. Conversely, in high-rank coal, a lower content of oxygen-containing functional groups and aliphatic structures, along with stronger intramolecular forces, results in fewer chemical bond breakages and makes it less conducive to the formation of new aromatic structures. These results elucidate the specific deformations of different chemical groups, offering a molecular-level understanding of the interaction between CO2 and coal.

Enhancing Fruit Crop Performance: The Role of Phosphate-Solubilizing Bacteria in Growth, Yield and Quality Improvement

Phosphorus is a crucial macronutrient in plant development, playing a vital role in metabolic activities and growth. Due to its poor availability in soil, phosphorus (P) is essential for healthy plant growth, particularly in tropical regions. P is present in nucleic acids, catalysts, coenzymes, nucleotides, and phospholipids. Optimal phosphorus availability is essential for plant reproductive structure formation during early development. Soil phosphorus content is around 0.05%, but due to insoluble phosphates, soluble forms are not readily available for plants. Chemical P fertilizers are used to increase available P levels, but these are costly and have negative environmental impacts. The limited P-source and high-quality rock P deposits may be exhausted within the next century, leading to the search for environmentally friendly alternatives. Biofertilizers with P-solubilizing properties are an environmentally friendly alternative to chemical-based Phosphorus fertilizers. PSB, beneficial microorganisms, hydrolyse insoluble phosphorus compounds into soluble P, facilitating plant uptake. This eco-friendly and economically sound approach overcomes P scarcity. Throughout the review, these PSBs are discussed in terms of how they have been applied and used to improve fruit crop growth, yield, and quality, providing promising evidence that these PSBs can be used as a viable alternative to inorganic phosphate fertilizers in the future for sustainable agriculture.