Kobresia humilis via root-released flavonoids recruit Bacillus for promoted growth.

Alpine meadows, which are critical for biodiversity and ecosystem services, are increasingly degrading, necessitating effective restoration strategies. This study explored the mechanism by which Kobresia humilis, an alpine meadow-constructive species, modulates the rhizosphere microbiome via root exudates to enhance growth. Field investigations revealed that the plant height of K. humilis in a severely degraded (SD) alpine meadow was significantly higher than that in other K. humilis populations. Consequently, we analysed the differences between this plot and other K. humilis samples with different degrees of degradation to explore the reasons underlying the phenotypic differences in K. humilis. 16 S rRNA amplicon sequencing results showed that the SD plots were significantly enriched with more Bacillus, altering the composition of the rhizosphere microbial community of K. humilis. The collection and analysis of root exudates from various K. humilis locations revealed distinct differences. Procrustes analysis indicated a strong correlation between the root exudates and the rhizosphere microbiome composition of K. humilis. Model-based integration of metabolite observations, species abundance 2 (MIMOSA2), and Spearman's rank correlation coefficient analysis were used to identify the root exudates potentially related to the enrichment and recruitment of Bacillus. Bacillus from SD samples was isolated and screened, and the representative strain D334 was found to be differentially enriched compared to other samples. A series of in vitro experiments with the screened root exudates and strain D334 demonstrated that K. humilis could recruit Bacillus and promote its colonisation by releasing flavonoids, particularly baicalin. Additionally, K. humilis can release sucrose and riboflavin, which promote strain growth. Finally, soil microbiome transplantation experiments confirmed that different K. humilis phenotypes were closely related to the functions of the rhizosphere microbiome, especially in root morphological shaping. Moreover, the effects of Bacillus inoculation and the microbiome on the plant phenotypes were consistent. In summary, this study revealed a new mechanism by which K. humilis recruits rhizosphere growth-promoting bacteria and enhances soil nutrient utilisation, thereby promoting plant growth. These findings provide a theoretical basis for ecological restoration using soil microbial communities and clarify the relationship between plant metabolites and microbial community assembly.

The Simulation of Ester Lubricants and Their Application in Weak Gel Drilling Fluids.

To enhance the performance and reduce the amount of ester-based lubricants used in weak gel drilling fluids, a shear dynamics simulation under extreme pressure conditions was employed to refine the formulation of the base oil and pressure additives. The simulation results were validated using fatty acid methyl, ethyl, and butyl esters. Fatty acid methyl ester demonstrated the lowest temperature increase and the highest load-bearing capacity post-shear. The four-ball friction test revealed that methyl oleate had a coefficient of friction of 0.0018, approximately a third of that for butyl oleate, confirming the simulation's accuracy. By using methyl oleate as the base oil and oleamide as the pressure-resistant component, the optimal shear stress was achieved with a 10% addition of oleamide. A lubricant composed of 90% methyl oleate and 10% oleamide was tested and showed a coefficient of friction of 0.03 when 0.5% was added to bentonite slurry, indicating a strong lubricating film. Adding 1% of this lubricant to a low gel drilling fluid system did not affect its rheological properties, and the gel structure remained stable after seven days of aging. Field tests at the Fu86-3 well in the Jiangsu Oilfield of Sinopec confirmed that adding 1% of the ester-based lubricant to the drilling fluid significantly improved drilling efficiency, reduced drag by an average of 33%, and increased the drilling rate to 22.12 m/h. This innovation effectively prevents drilling complications and successfully achieves the objectives of enhancing efficiency.

Peanut shells-derived biochars as adsorbents for the pipette-tip solid-phase extraction of endocrine-disrupting phenols in water, milk and beverage.

In the present work, a type of biochar materials derived from carbonizing peanut shells were obtained and employed as the adsorbents of pipette-tip solid-phase extraction (PT-SPE) for the enrichment and determination of six endocrine-disrupting phenols (EDPs) in combination with high-performance liquid chromatography equipped with ultraviolet detector (HPLC-UV). Abundant aliphatic and aromatic carbon structures and functional groups from polar heteroatoms (N, O, S) were distributed in the low-cost and eco-friendly peanut shells-derived biochar materials and were favorable for the enrichment of target EDPs. Moreover, the theoretical calculation based on density functional theory (DFT) proved that the effective enrichment of EDPs in aqueous samples benefited from the effective adsorption on the peanut shells-derived biochar materials. The experimental factors influencing the extraction efficiency were investigated, including adsorbent amount, aspirating/dispensing cycles, the type of elution solvent and elution times, salt addition, sample solution pH and type and volume of washing solvent. Under the optimal conditions, the proposed PT-SPE method exhibited good linear relationship (R2 > 0.993) in the range of 0.5-400 µg/L and low limits of detections (LODs) from 0.25 to 2.5 µg/L, as well as good precision and accuracy with relative standard deviations (RSDs) of 0.3%-13.2% and recoveries of 83.5%-117.1%. Finally, the biochars-based miniaturized pretreatment method was employed for the determination of six EDPs in bottled water, milk, tea beverage and disposal plastic bag soaked solution with recoveries from 77.5% to 116.5%.

Adsorption and solvent desorption behavior of ion-exchanged modified Y zeolites for sulfur removal and for fuel cell applications.

Typical ion-exchanged modified Y zeolites (AgY and CeY) were prepared for sulfur removal. The adsorption and desorption behavior of typical sulfur and hydrocarbon molecules in various Y zeolites has been investigated by the adsorption breakthrough and on site solvent washing experiments, as well as computer simulation. Breakthrough experiments showed that the adsorption capacity for thiophenic sulfur increased for the studied adsorbents as follows: CeY > AgY > NaY. The higher initial sulfur concentration accelerated the appearance of breakthrough, and the outlet sulfur concentration, in all cases, cannot reach the corresponding initial sulfur level. The concentration profile of washing solvent during desorption process showed that most of the sulfur compounds could be recovered at initial desorption stage. The desorption rates of typical Y zeolites follow the order: NaY > AgY > CeY, which is the reverse as that found in adsorption capacity. The distinct adsorption and desorption behavior of CeY, AgY, and NaY zeolites was markedly related with their various binding force (S-M coordination, π-complexation, and Van der Waals force) with sulfur compounds. The adsorption isotherms and density distribution snapshots study by computer simulation confirmed the preferential adsorption of thiophenic sulfur.