有机电极材料过渡态的研究进展

有机电极材料具有理论比容量大、结构可设计性强、加工使用过程环境友好等优点被广泛应用于二次电池的研究中。有机电极材料在氧化还原过程会产生具有不成对电子的自由基中间体,自由基中间体的稳定程度影响电极材料的电化学性能。通过改变材料的结构可以调控自由基中间体的稳定性,从而优化有机电极材料的电化学性能。本文对有机电极材料在电化学过程中产生的自由基中间体进行了分类介绍,阐明了材料结构、自由基中间体稳定性和电化学性能之间的关系。

Preparation and characterization of resistant starch type 3 from yam and its effect on the gut microbiota

Background:Yam(Dioscorea opposita Thunb.)has been consumed as a food and used in traditional Chinese medicine for thousands of years.Resistant starch(RS)3 is of particular interest because it is heat-resistant,safe and non-toxic,and retains good nutritional benefits;it is therefore used in a wide range of traditional and emerging foods as a heat-stable prebiotic ingredient.In our previous study,we found that yam RS includes strong lipid-lowering and anti-constipation activities.Methods:Yam RS3 was prepared by autoclaving-retrogradation and pullulanase debranching to yield autoclaving-retrogradation yam RS and pullulanase debranching yam RS,respectively.First,the physicochemical properties of both RS3s were analyzed.Second,the structures of the RS3s were characterized by scanning electron microscopy,X-ray powder diffraction,and Fourier transform infrared spectroscopy.Finally,the regulatory effects of the RS3s on the gut microbiota were evaluated using an in vitro fecal fermentation model.Results:The RS content of the RS3s decreased after processing,but was higher in pullulanase debranching yam RS(35.67%)than in autoclaving-retrogradation yam RS(28.71%).Compared with native yam starch,RS3s lost their original granular shapes and instead exhibited irregularly shapes with continuous phases.The crystalline structure of the RS3s was completely altered,with pullulanase debranching yam RS exhibiting B-type patterns.Both RS3s,and especially pullulanase debranching yam RS,promoted a significant increase in short chain fatty acid content after in vitro fermentation(all P<0.05).Moreover,pullulanase debranching yam RS significantly increased the abundance of beneficial bacteria and decreased the abundance of harmful bacteria such as Escherichia and Shigella(all P<0.05).Conclusion:Our findings show that yam RS3s can regulate the composition of the gut microbiota and promote the production of short chain fatty acid,especially butyric acid.Pullulanase debranching was a more effective method for producing functional yam RS3.

Quality evaluation of Pinelliae Rhizoma using network pharmacology and multi-component quantitative analysis

Background:Pinelliae Rhizoma(Banxia)is a valuable traditional Chinese medicine,and its quality issues are related to the safety and effectiveness of the medicine.Several pharmacological experiments have shown that Pinelliae Rhizoma has anti-inflammatory activity,but the specific chemical components remain unclear.Methods:In the present study,network pharmacology was used to analyze the potential active ingredients and molecular mechanisms of Pinelliae Rhizoma’s anti-inflammatory activity.A new approach to simultaneously determine eight components using high performance liquid chromatography-photo-diode array was developed to evaluate the quality of Pinelliae Rhizoma and different processed Pinelliae Rhizoma products.Results:Twelve active ingredients were identified from Pinelliae Rhizoma,andβ-sitosterol may have a greater effect than the other active ingredients.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed the main pathways associated with Pinelliae Rhizoma’s mechanism for treating inflammation.Additionally,theβ-sitosterol content in different processed Pinelliae Rhizoma products decreased significantly,and the level of five nucleosides in Pinelliae Rhizoma was significantly higher than that of the processed Pinelliae Rhizoma products.The 6-gingerol content was detected in eight Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine batches with different origins,and liquiritin and liquiritigenin levels were detected in eight batches of Pinelliae Rhizoma Praeparatum with different origins.Conclusion:Pinelliae Rhizoma quality was affected by different regions and different processing methods,and this research provides a reference for Pinelliae Rhizoma quality evaluation.