Rhizosphere-Associated Anammox Bacterial Diversity and Abundance of Nitrogen Cycle-Related Functional Genes of Emergent Macrophytes in Eutrophic Wetlands

Rhizospheric microbial community of emergent macrophytes plays an important role in nitrogen removal, especially in the eutrophic wetlands. The objective of this study was to identify the differences in anammox bacterial community composition among different emergent macrophytes and investigate revealed the the main factors affecting on the composition, diversity, and abundance of anammox bacterial community. Results showed that the composition, diversity, and abundance of the anammox community were significantly different between the vegetated sediments of three emergent macrophytes and unvegetated sediment. The composition of the anammox bacterial community was different in the vegetated sediments of different emergent macrophytes. Also, the abundance of nitrogen cycle-related functional genes in the vegetated sediments was found to be higher than that in the unvegetated sediment. Canonical correspondence analysis (CCA) and structural equation models analysis (SEM) showed that salinity and pH were the main environmental factors influencing the composition and diversity of the anammox bacterial community and NO2--N indirectly affected anammox bacterial community diversity by affecting TOC. nirK-type denitrifying bacteria abundance had significant effects on the bacterial community composition, diversity, and abundance of anammox bacteria. The community composition of anammox bacteria varies with emergent macrophyte species. The rhizosphere of emergent macrophytes provides a favorable environment and promotes the growth of nitrogen cycling-related microorganisms that likely accelerate nitrogen removal in eutrophic wetlands.

Characterization of the interactions between Fulvic acid and Trypsin with Spectroscopic and Molecular Docking technology

The interaction mechanism between trypsin and fulvic acid was analyzed by multispectral method and molecular docking simulation. The fluorescence spectra showed that fulvic acid induced static quenching of trypsin. The validity of this conclusion was further substantiated through the computation of the binding constants. The thermodynamic parameters show that the reaction is mainly controlled by van der Waals force and hydrogen bond force, and the reaction is spontaneous. In addition, based on the obtained binding distance, there may be a non-radiative energy transfer between the two. The ultraviolet spectrum showed that fulvic acid could shift the absorption peak of trypsin, indicating that fulvic acid had an effect on the secondary structure of trypsin. According to the synchronous fluorescence spectrum results, fulvic acid primarily interacts with tryptophan residues in trypsin and induces alterations in their microenvironment. Three-dimensional fluorescence spectrum and circular dichroism further proves this conclusion. The molecular docking simulation reveals that the interaction between the two groups primarily arises from hydrogen bonding and van der Waals forces. The findings suggest that FA has the ability to induce conformational changes in trypsin's secondary structure.

Effect of Chloramphenicol as Antibiotic on the Structure and Function of Pepsin and Its Mechanism of Action

The interaction between chloramphenicol (CHL) and pepsin (PEP), as well as the impact of CHL on PEP conformation, were investigated using spectroscopic techniques and molecular docking simulations in this study. The experimental results demonstrate that CHL exhibits a static quenching effect on PEP. The thermodynamic parameters indicate that the reaction between CHL and PEP is spontaneous, primarily driven by hydrogen bonding and van der Waals forces. Moreover, the binding distance of r<7 nm suggests the occurrence of Förster's non-radiative energy transfer between these two molecules. In the synchronous fluorescence spectrum, the maximum fluorescence intensity of PEP produced a redshift phenomenon, indicating that CHL was bound to tryptophan residues of PEP. The addition of CHL induces changes in the secondary structure of PEP, as confirmed by the observed alterations in peak values in three-dimensional fluorescence spectra. The UV spectra reveal a redshift of 3 nm in the maximum absorption peak, indicating a conformational change in the secondary structure of PEP upon addition of CHL. Circular dichroism analysis demonstrates significant alterations in the α-helix, β-sheet, β-turn, and random coil contents of PEP before and after CHL incorporation, further confirming its ability to modulate the secondary structure of PEP.

Optimization Strategy in Hydrogen Storage Performance of Ti─V─Cr─Mn Alloys via LiAlH4

V-based solid solution materials hold a significant position in the realm of hydrogen storage materials because of its high hydrogen storage capacity. However, the current dehydrogenation temperature of V-based solid solution exceeds 350 °C, making it challenging to fulfill the appliance under moderate conditions. Here advancements in the hydrogen storage properties and related mechanisms of TiV1.1 Cr0.3 Mn0.6  + x LiAlH4 (x = 0, 5, 8, 10 wt.%) composites is presented. According to the first principle calculation analysis, the inclusion of Al and Li atoms will lower the binding energy of hydride, thus enhancing the hydrogen absorption reaction and significantly decreasing the activation difficulty. Furthermore, based on crystal orbital Hamilton population (COHP) analysis, the strength of the V─H and Ti─H bonds after doping LiAlH4 are reduced, leading to a decrease of the hydrogen release activation energy (Ea ) for the V-based solid solution material, thus the hydrogen release process is easier to carry out. Additionally, the structure of doped LiAlH4 exhibits an outstanding hydrogen release rate of 2.001 wt.% at 323 K and remarkable cycling stability.

Mechanisms by which the intestinal microbiota affects gastrointestinal tumours and therapeutic effects

The intestinal microbiota is considered to be a forgotten organ in human health and disease. It maintains intestinal homeostasis through various complex mechanisms. A significant body of research has demonstrated notable differences in the gut microbiota of patients with gastrointestinal tumours compared to healthy individuals. Furthermore, the dysregulation of gut microbiota, metabolites produced by gut bacteria, and related signal pathways can partially explain the mechanisms underlying the occurrence and development of gastrointestinal tumours. Therefore, this article summarizes the latest research progress on the gut microbiota and gastrointestinal tumours. Firstly, we provide an overview of the composition and function of the intestinal microbiota and discuss the mechanisms by which the intestinal flora directly or indirectly affects the occurrence and development of gastrointestinal tumours by regulating the immune system, producing bacterial toxins, secreting metabolites. Secondly, we present a detailed analysis of the differences of intestinal microbiota and its pathogenic mechanisms in colorectal cancer, gastric cancer, hepatocellular carcinoma, etc. Lastly, in terms of treatment strategies, we discuss the effects of the intestinal microbiota on the efficacy and toxic side effects of chemotherapy and immunotherapy and address the role of probiotics, prebiotics, FMT and antibiotic in the treatment of gastrointestinal tumours. In summary, this article provides a comprehensive review of the pathogenic mechanisms of and treatment strategies pertaining to the intestinal microbiota in patients with gastrointestinal tumours. And provide a more comprehensive and precise scientific basis for the development of microbiota-based treatments for gastrointestinal tumours and the prevention of such tumours.

Effect of ionic liquids on the microstructure and combustion performance of Shengli lignite

To ensure the safe transportation and efficient utilisation of lignite, it is important to inhibit its spontaneous combustion. In this study, Shengli lignite (SL+) was used as the research object and ionic liquids (ILs) were used to pretreat the lignite to investigate their effect on the combustion performance of lignite. On this basis, the relationship between the structure and combustion performance of lignite with different structures (heat treatment, oxidation) after ILs treatment was investigated. Results indicated that the combustion of lignite treated with ILs shifted towards higher temperatures. The most pronounced effect was observed in coal samples treated with [BMIM]Cl (1-butyl-3-methylimidazolium chloride), with the maximum combustion rate corresponding to a temperature increase of approximately 57 °C compared to that of the untreated lignite. For the heat-treated lignite, the temperature corresponding to the maximum combustion rate was approximately 38 °C higher than that of the untreated lignite. After [BMIM]Cl treatment, the combustion performance of the heat-treated lignite changed very slightly. In contrast, for oxidised lignite, the temperature corresponding to the maximum combustion rate decreased by approximately 54 °C compared with that of the untreated lignite and increased by approximately 135 °C after treatment with [BMIM]Cl. The characterisation results show that the content of aliphatic hydrogen and oxygen-containing functional groups decreased in the heat-treated lignite, while the content of hydroxyl and carboxyl groups increased in the oxidised lignite. The microstructure of the heat-treated lignite after [BMIM]Cl treatment changed slightly. In contrast, in the oxidised lignite after [BMIM]Cl treatment, the content of hydroxyl and carboxyl groups decreased, whereas the content of ether (C-O-) structures increased. The increased content of ether (C-O-) structures improved the stability of the coal samples. It is believed that the inhibition of lignite combustion is mainly attributed to the high stability of the ether (C-O-) structures. The kinetic analysis demonstrated that the ILs treatment increased the activation energy of lignite combustion.

Crack Damage Propagation and Morphology Distribution of Hydraulic Electric Pulse Fractured Coal

This work discusses the damage and failure effect of a hydraulic electric pulse and the law of crack growth on coal. The impact and failure effect of a water shock wave and the mechanism of crack initiation, propagation, and arrest were studied by numerical simulation and the fracturing test of coal, combined with CT scanning, PCAS software, and Mimics 3D reconstruction technology. The results show that a high voltage electric pulse that increases permeability is an effective artificial crack making technology. The crack spreads radially along the borehole, and the damage degree, number, and complexity were positively correlated with the discharge voltage and discharge times. The crack area, volume, damage factor, and other parameters increased steadily. The cracks in the coal first start from two symmetrical angles, and finally distribute in a 360 deg circumferential direction, forming a multiangle crack spatial network structure. The fractal dimension of the crack group increases, the number of microcracks and the roughness of the crack group increases, the overall fractal dimension of the specimen decreases, and the roughness between cracks weakens. The cracks then form a smooth coal-bed methane migration channel. The research results can provide some theoretical guidance for the evaluation of crack damage propagation and the effect of electric pulse fracturing in water.

Multiscale Convolutional Network for Repairing Coal Slime Foam Images

Visual feature information regarding flotation foam is crucial for the flotation process. Owing to a large amount of noise and blur in the foam images collected in the floatation field, feature extraction and segmentation of foam images pose considerable challenges. Furthermore, the visual properties of foam are strongly correlated with current flotation conditions. Therefore, this study presents a method to repair blurred pixels in foam images. In addition to enhancing the image dataset necessary for network model training, the restored images can provide high-quality images extracting foam-feature information. In addition, this research presents a novel fifth-order residual structure that enlarges the network structure by stacking, enhancing the learning ability of complex networks. Experimental results demonstrate that the suggested method can achieve a satisfactory repair effect for foam images under various blurring conditions, laying a foundation for guiding the intelligent adjustment of flotation field parameters.

Effect of Benzyl Alcohol on Biomethanation from Lignite

Currently, biomethane obtained from coal resources, such as lignite and peat, serves as a sustainable biofuel urgently needed by the energy economy. To improve biomethane yield from lignite, the effects of different concentrations of benzyl alcohol, a degraded product of humic acid, on a biomethanation fermentation system were analyzed. The total biomethane yield, daily biomethane yield, coenzyme F₄₂₀, VFA (volatile fatty acids) concentration, alkalinity, and pH were used to determine the optimal benzyl alcohol concentration. The biomethanation fermentation system with 2000 mg/L benzyl alcohol produced up to 4.03 mL/g of biomethane, which was 1.15 times that produced from the control group. The coenzyme F₄₂₀, VFA, alkalinity, and pH of the system after adding 2000 mg/L benzyl alcohol were more preferable after adding other concentrations during the lignite biomethanation process. In summary, 2000 mg/L benzyl alcohol had a significantly positive effect on the lignite biomethanation fermentation system. When benzyl alcohol is added to the fermentation system, it accelerates the tricarboxylic acid cycle, which in turn produces more biomethane. Additionally, the self-supply of lignite microbial transformation nutrients from the perspective of chemical composition was explored as a novel approach in solving the common problem of low biomethane yield from a single lignite raw material. This also laid a foundation for subsequent steps through the adjustment of pretreatment conditions to ensure that the lignite pretreatment liquid contained increased benzyl alcohol, and a greater yield of biomethane can be produced after activated sludge addition.