Co 3 O 4 is a well-known catalyst in the oxidation reaction. In such a catalyst, the geometric and electronic structures of tetrahedrally coordinated Co 2+ and octahedrally coordinated Co 3+ can be regulated by directional metal ion substitution strategy, accompanied by the modification of catalytic activity. Herein, normal and inverse cobalt-based spinel catalysts M x Co 3−x O 4 (M = Zn and Ni) with a threedimensionally ordered macroporous (3DOM) structure were successfully fabricated through the carboxy-modified colloidal crystal templating (CMCCT) method. The relationship between the dopant and activity during NO x -assisted soot oxidation was systematically studied by means of XPS, H 2 -TPR, soot-TPR, isothermal anaerobic titrations, NO-TPO, soot-TPO, and so on. The well-defined 3DOM structure for M x Co 3−x O 4 catalysts can improve the contact efficiency of soot and catalysts. 3DOM NiCo 2 O 4 exhibits high catalytic activity for soot oxidation under a loose contact mode between soot and catalyst. For instance, its T 50 and TOF values are 379 °C and 1.36 × 10 −3 s −1 , respectively. The doping of Ni to Co 3 O 4 will induce the structural distortion, improve the density of oxygen vacancies, and enhance lattice oxygen mobility. It leads to more surface-active oxygen species. A vacancy-mediated pathway of NO oxidation on the spinel catalyst is proposed according to the experimental results of in situ DRIFT spectra, in situ Raman spectra, and the theoretical knowledge of coordination chemistry of metal−NO. The catalytic performance of soot oxidation is highly related to the capacity of a catalyst in oxidizing NO to NO 2 . Therefore, indirect NO 2 -assisted mechanism is proposed for soot oxidation under an NO/O 2 /N 2 atmosphere.
Together, our data suggest that the TXNIP/NLRP3 pathway is a potential therapeutic target for the treatment of DR, and the use of minocycline specifically for such therapy may be a new avenue of investigation in inflammatory disease.
This study is a contribution to the exploration of natural phospholipid (PL) sources rich in long-chain polyunsaturated fatty acids (LC-PUFAs) with nutritional interest. Phosphatidylcholines (PCs) were purified from total lipid extracts of different food matrices, and their molecular species were separated and identified by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS(2)). Fragmentation of lithiated adducts allowed for the identification of fatty acids linked to the glycerol backbone. Soy PC was particularly rich in species containing essential fatty acids, such as (18:2-18:2)PC (34.0%), (16:0-18:2)PC (20.8%), and (18:1-18:2)PC (16.3%). PC from animal sources (ox liver and egg yolk) contained major molecular species, such as (16:0-18:2)PC, (16:0-18:1)PC, (18:0-18:2)PC, or (18:0-18:1)PC. Finally, marine source (krill oil), which was particularly rich in (16:0-20:5)PC and (16:0-22:6)PC, appeared to be an interesting potential source for food supplementation with LC-PUFA-PLs, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Our results indicate that relatively low-dose GML consumption promotes metabolic syndrome, gut microbiota dysbiosis, and systemic low-grade inflammation, thereby calling for a reassessment of GML usage.
Obesity and associated metabolic disorders are worldwide public health issues. The gut microbiota plays a key role in the pathophysiology of diet-induced obesity. Glycerol monolaurate (GML) is a widely consumed food emulsifier with antibacterial properties. Here, we explore the anti-obesity effect of GML (1,600 mg/kg of body weight) in high-fat diet (HFD)-fed mice. HFD-fed mice were treated with 1,600 mg/kg GML. Integrated microbiome, metabolome, and transcriptome analyses were used to systematically investigate the metabolic effects of GML, and antibiotic treatment was used to assess the effects of GML on the gut microbiota. Our data indicated that GML significantly reduced body weight and visceral fat deposition, improved hyperlipidemia and hepatic lipid metabolism, and ameliorated glucose homeostasis and inflammation in HFD-fed mice. Importantly, GML modulated HFD-induced gut microbiota dysbiosis and selectively increased the abundance of Bifidobacterium pseudolongum. Antibiotic treatment abolished all the GML-mediated metabolic improvements. A multiomics (microbiome, metabolome, and transcriptome) association study showed that GML significantly modulated glycerophospholipid metabolism, and the abundance of Bifidobacterium pseudolongum strongly correlated with the metabolites and genes that participated in glycerophospholipid metabolism. Our results indicated that GML may be provided for obesity prevention by targeting the gut microbiota and regulating glycerophospholipid metabolism.
Glycerol monolaurate (GML) has potent antimicrobial and anti-inflammatory activities. The present study aimed to assess the dose-dependent antimicrobial-effects of GML on the gut microbiota, glucose and lipid metabolism and inflammatory response in C57BL/6 mice. Mice were fed on diets supplemented with GML at dose of 400, 800 and 1600 mg kg−1 for 4 months, respectively. Results showed that supplementation of GML, regardless of the dosages, induced modest body weight gain without affecting epididymal/brown fat pad, lipid profiles and glycemic markers. A high dose of GML (1600 mg kg−1) showed positive impacts on the anti-inflammatory TGF-β1 and IL-22. GML modulated the indigenous microbiota in a dose-dependent manner. It was found that 400 and 800 mg kg−1 GML improved the richness of Barnesiella, whereas a high dosage of GML (1600 mg kg−1) significantly increased the relative abundances of Clostridium XIVa, Oscillibacter and Parasutterella. The present work indicated that GML could upregulate the favorable microbial taxa without inducing systemic inflammation and dysfunction of glucose and lipid metabolism.
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