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Graves’ disease (GD) is an autoimmune disorder disease, and its prevalence continues to increase worldwide. Pyrroloquinoline quinone (PQQ) is a naturally antioxidant compound in milk, vegetables, and meat. We aim to identify the treatment efficacy of PQQ on GD and its regulatory effect on intestinal microbiota. The GD mice model was built by an adenovirus expressing autoantigen thyroid-stimulating hormone receptor (Ad-TSHR289). Fecal samples were collected for 16S rDNA sequencing after PQQ pretreatments (20, 40, or 60 mg/kg BW/day) for 4 weeks. Thyroid and intestine functions were measured. The levels of serum TSHR and T4 were significantly raised, and the thyroid gland size was typically enlarged in the GD group than in controls, reversed by PQQ therapy. After PQQ replenishment, IL6 and TNFα levels in small intestine tissues were lower than those in the GD group, with Nrf2 and HO1 levels improved. Also, the PQQ supplement could maintain the mucosal epithelial barrier impaired by GD. In microbial analyses, PQQ treatment could prompt the diversity recovery of gut microbiota and reconstruct the microbiota composition injured by GD. Lactobacillus served as the most abundant genus in all groups, and the abundance of Lactobacillus was increased in the GD group than in control and PQQ groups. Besides, Lactobacillus was highly correlative with all samples and the top 50 genera. PQQ supplementation regulates thyroid function and relieves intestine injury. PQQ changes the primary composition and abundance of GD’s intestine microbiota by moderating Lactobacillus, which may exert in the pathogenesis and progression of GD.

Background: Despite the potential radiotoxicity in differentiated thyroid cancer (DTC) patients with high-dose 131I therapy, the alterations and regulatory mechanisms dependent on intestinal microecology remain poorly understood. We aimed to identify the characteristics of the gut microbiota and metabolites in DTC patients suffering from high-dose 131I therapy and explore the radioprotective mechanisms underlying arachidonic acid (ARA) treatment. Methods: A total of 102 patients with DTC were recruited, with fecal samples collected before and after 131I therapy for microbiome and untargeted and targeted metabolomic analyses. Mice were exposed to total body irradiation with ARA replenishment and antibiotic pretreatment and were subjected to metagenomic, metabolomic, and proteomic analyses. Results: 131I therapy significantly changed the structure of gut microbiota and metabolite composition in patients with DTC. Lachnospiraceae were the most dominant bacteria after 131I treatment, and metabolites with decreased levels and pathways related to ARA and linoleic acid were observed. In an irradiation mouse model, ARA supplementation not only improved quality of life and recovered hematopoietic and gastrointestinal systems but also ameliorated oxidative stress and inflammation and preserved enteric microecology composition. Additionally, antibiotic intervention eliminated the radioprotective effects of ARA. Proteomic analysis and ursolic acid pretreatment showed that ARA therapy greatly influenced intestinal lipid metabolism in mice subjected to irradiation by upregulating the expression of hydroxy-3-methylglutaryl-coenzyme A synthase 1. Conclusion: These findings highlight that ARA, as a key metabolite, substantially contributes to radioprotection. Our study provides novel insights into the pivotal role that the microbiota-metabolite axis plays in radionuclide protection and offers effective biological targets for treating radiation-induced adverse effects. [ABSTRACT FROM AUTHOR]

Because of high pumping loss under part loads and the low compression ratio, gasoline engines have very poor fuel economy. Therefore, in order to reduce the fuel consumption of gasoline engines, this paper mainly studied the influence of EGR coupling with different excess air coefficients on the combustion characteristics, fuel economy, and emission characteristics under part loads of the gasoline engine. The engine used in this experiment was a 1.5L 4-cylinder gasoline engine, with port fuel injection and turbocharged, which had a peak power of 110 kW @ 5600r/min. Before the experiment, the inlet and exhaust systems of the engine were modified, and equipped with a water-cooled EGR system. The EGR gas flowed out after the three-way catalytic converter, then entered an EGR cooler, and mixed with the fresh air in the intake pipe before entering the compressor, and at last entered into the cylinders. And this EGR system was also called a low pressure loop system. During the experiment, the engine operated at a part load point, 2000 rpm and 0.5 MPa BMEP. The EGR ratio and excess air coefficient were changed to study the effect on the combustion characteristics, fuel economy, and emission characteristics under the part load of the gasoline engine. The results showed that with the increase of the EGR rate and excess air coefficient, the rate of cycle-to-cycle variation of the combustion increased, the combustion duration became longer, and that the EGR was the main factor affecting both of them. The brake specific fuel consumption decreased significantly, because of the dramatic reduction of the pumping loss. Comparied to the condition of EGR ratio=0 and α=1, the brake specific fuel consumption decreased by 8.37% under the condition of EGR ratio=20% and α=1.1. With the increase of the EGR rate and excess air coefficient, THC emission increased, but NOX emission decreased significantly by about 80%. Therefore, combining the three-way catalytic converter with EGR technology can greatly improve the fuel economy of the part load of the gasoline engine, and may meet the emission regulation of Euro 5 at the same time. [ABSTRACT FROM AUTHOR]