Research on the effect of water-cooling steel pipe on preventing spontaneous combustion of coal pile and its thermal migration behavior.

During the storage and transportation process after mining, coal piles are placed in open environments, making them prone to self-heating and spontaneous combustion due to the nature of coal and factors like natural wind flow. In recent years, there have been frequent spontaneous combustion incidents involving coal piles, posing significant safety risks. To effectively prevent and control spontaneous combustion disasters in open-air coal storage piles, we propose a method involving the arrangement of water-cooling steel pipes within the coal piles. This method applies theories of coal spontaneous combustion mechanisms, porous media heat transfer, and non-isothermal pipeline heat transfer. The multi-physics coupling model of COMSOL numerical simulation software is used to analyze the spontaneous ignition process and prevention effect of open pit coal pile. In the model, the thin material transfer of porous media is taken as the oxygen concentration field, the heat transfer of porous media is taken as the temperature field, and the free and porous media flow is taken as the air seepage velocity field. The simulation results of the spontaneous combustion process in the coal pile indicate that the high-temperature zone of spontaneous combustion is situated within the range of 0.5 ~ 1.5 m inside the wind-facing surface and extends 0.5 m above the ground level. These findings serve as a basis for determining the optimal placement of water-cooling steel pipes within the coal pile. The simulation results of a single water-cooling steel pipe demonstrate a positive correlation between the cooling effect on the coal pile and the water cool flow, and a negative correlation with the water cool temperature. Additionally, the cooling radius of the water-cooling steel pipe is determined by the circumference of the pipe and remains unaffected by the water cool flow. Finally, simulations were conducted to evaluate the cooling effect of multiple rows of steel pipes, and optimal arrangement parameters were determined: a center distance between steel pipes of 1 m and a water cool flow rate of 1500 L/min. As a result, the onset of the self-heating period in the coal pile was delayed by 11 days, and the spontaneous combustion period was extended by 56 days. The arrangement of water-cooling steel pipes in the coal pile has demonstrated significant efficacy in preventing and controlling spontaneous combustion.

Restoration of dysregulated intestinal barrier and inflammatory regulation through synergistically ameliorating hypoxia and scavenging reactive oxygen species using ceria nanozymes in ulcerative colitis.

BACKGROUND: Reactive oxygen species (ROS) overproduction and excessive hypoxia play pivotal roles in the initiation and progression of ulcerative colitis (UC). Synergistic ROS scavenging and generating O2 could be a promising strategy for UC treatment. METHODS: Ceria nanozymes (PEG-CNPs) are fabricated using a modified reverse micelle method. We investigate hypoxia attenuating and ROS scavenging of PEG-CNPs in intestinal epithelial cells and RAW 264.7 macrophages and their effects on pro-inflammatory macrophages activation. Subsequently, we investigate the biodistribution, pharmacokinetic properties and long-term toxicity of PEG-CNPs in mice. PEG-CNPs are administered intravenously to mice with 2,4,6-trinitrobenzenesulfonic acid-induced colitis to test their colonic tissue targeting and assess their anti-inflammatory activity and mucosal healing properties in UC. RESULTS: PEG-CNPs exhibit multi-enzymatic activity that can scavenge ROS and generate O2, promote intestinal epithelial cell healing and inhibit pro-inflammatory macrophage activation, and have good biocompatibility. After intravenous administration of PEG-CNPs to colitis mice, they can enrich at the site of colonic inflammation, and reduce hypoxia-induced factor-1α expression in intestinal epithelial cells by scavenging ROS to generate O2, thus further promoting disrupted intestinal mucosal barrier restoration. Meanwhile, PEG-CNPs can effectively scavenge ROS in impaired colon tissues and relieve colonic macrophage hypoxia to suppress the pro-inflammatory macrophages activation, thereby preventing UC occurrence and development. CONCLUSION: This study has provided a paradigm to utilize metallic nanozymes, and suggests that further materials engineering investigations could yield a facile method based on the pathological characteristics of UC for clinically managing UC.

Hyaluronic acid-based M1 macrophage targeting and environmental responsive drug releasing nanoparticle for enhanced treatment of rheumatoid arthritis.

Herein, hyaluronic acid (HA) and ß-cyclodextrin (ß-CD) is used to form targeted drug delivery platform HCPC/DEX NPs with previously prepared carbon dots (CDs) as cross-linker, dexamethasone (DEX) is loaded for rheumatoid arthritis (RA) treatment. The drug loading capacity of ß-CD and M1 macrophage targeting of HA were utilized for efficient delivery of DEX to the inflammatory joints. Because of the environmental responsive degradation of HA, DEX can be released in 24 h and inhibit the inflammatory response in M1 macrophages. The drug loading of NPs is 4.79 %. Cellular uptake evaluation confirmed that NPs can specifically target to M1 macrophages via HA ligands, the uptake of M1 macrophages is 3.7 times that of normal macrophages. In vivo experiments revealed that NPs can accumulate in RA joints to alleviate inflammation and accelerate cartilage healing, the accumulation can be observed in 24 h. The cartilage thickness increased to 0.45 mm after HCPC/DEX NPs treatment, indicating its good RA therapeutic effect. Importantly, this study was the first to utilize the potential acid and reactive oxygen species responsiveness of HA to release drug and prepare M1 macrophage targeting nanodrug for RA treatment, which provides a safe and effective RA therapeutic strategy.

Hyaluronic acid modified oral drug delivery system with mucoadhesiveness and macrophage-targeting for colitis treatment.

Based on the biocompatibility and macrophage targeting of natural polysaccharides, combined with the physiological and pathological characteristics of the gastrointestinal tract and colonic mucosa of ulcerative colitis (UC), we prepare dexamethasone (Dex)-loaded oral colon-targeted nano-in-micro drug delivery systems coated with multilayers of chitosan (CS), hyaluronic acid (HA), and finally Eudragit S100 (ECHCD MPs) using a layer-by-layer coating technique for UC treatment through regulating the M1/M2 polarization of intestinal macrophages. HA/CS/Dex nanoparticles (HCD NPs) are ingested by macrophages via CD44 receptor-mediated endocytosis to regulate M1-to-M2 macrophage polarization and exert anti-inflammatory effects. Moreover, ECHCD MPs show better colon-targeting properties than Dex-loaded chitosan nanoparticles (CD NPs) and HCD NPs which is demonstrated by stronger mucoadhesion to inflamed colon tissues. After oral administration, ECHCD MPs exert significant anti-UC effects. Therefore, ECHCD MPs are proven to be as promising oral colon-targeting drug delivery systems for Dex and have potential application in UC treatment.

Downregulation of Brassica napus MYB69 (BnMYB69) increases biomass growth and disease susceptibility via remodeling phytohormone, chlorophyll, shikimate and lignin levels.

MYB transcription factors are major actors regulating plant development and adaptability. Brassica napus is a staple oil crop and is hampered by lodging and diseases. Here, four B. napus MYB69 (BnMYB69s) genes were cloned and functionally characterized. They were dominantly expressed in stems during lignification. BnMYB69 RNA interference (BnMYB69i) plants showed considerable changes in morphology, anatomy, metabolism and gene expression. Stem diameter, leaves, roots and total biomass were distinctly larger, but plant height was significantly reduced. Contents of lignin, cellulose and protopectin in stems were significantly reduced, accompanied with decrease in bending resistance and Sclerotinia sclerotiorum resistance. Anatomical detection observed perturbation in vascular and fiber differentiation in stems, but promotion in parenchyma growth, accompanied with changes in cell size and cell number. In shoots, contents of IAA, shikimates and proanthocyanidin were reduced, while contents of ABA, BL and leaf chlorophyll were increased. qRT-PCR revealed changes in multiple pathways of primary and secondary metabolisms. IAA treatment could recover many phenotypes and metabolisms of BnMYB69i plants. However, roots showed trends opposite to shoots in most cases, and BnMYB69i phenotypes were light-sensitive. Conclusively, BnMYB69s might be light-regulated positive regulators of shikimates-related metabolisms, and exert profound influences on various internal and external plant traits.