Lactobacillus fermentum as a new inhibitor to control advanced glycation end-product formation during vinegar fermentation

The inhibitory activity of lactic acid bacteria(LAB)toward advanced glycation end-products(AGEs)during vinegar fermentation was studied,and its relationships with the substrate consumption,antioxidant capacity,total phenolic content,total flavonoid compounds,α-glucosidase,andα-amylase activity inhibition were evaluated.The vinegar was made from rice powder flour by liquid-state fermentation(LSF).The selected LAB strains were separately co-cultivated with Saccharomyces cerevisiae and Acetobacter pasteurianus 1.41 in alcoholic and acetic acid fermentation,respectively.Among 3 strains,Lactobacillus fermentum showed the strongest inhibitory effect on the formation of total fluorescent AGEs and carboxymethyl lysine(CML)/carboxyethyl lysine(CEL)in the fermentation process.The corresponding mechanisms included the acceleration of substrate consumtion,improvement of antioxidant activities,and inhibition ofα-glucosidase andα-amylase.In addition,the fluorescent AGEs and the CML/CEL were negatively correlated with the antioxidant activities,while theα-glucosidase andα-amylase activities were positively correlated with the total phenols and total flavonoids.Moreover,the variety of main flavor compounds increased,including esters,alcohols,phenols and acids.The results of the study support the potential use of screened LAB strains to inhibit the formation of fluorescent AGEs,CML and CEL on fermented products and in the food processing industry,without associated risks to consumers.

Preparation of ZrB_(2)-MoSi_(2) high oxygen resistant coating using nonequilibrium state powders by self-propagating high-temperature synthesis

To achieve high oxygen blocking structure of the ZrB_(2)-MoSi_(2) coating applied on carbon structural material,ZrB_(2)-MoSi_(2) coating was prepared by spark plasma sintering(SPS)method utilizing ZrB_(2)-MoSi_(2) composite powders synthesized by self-propagating high-temperature synthesis(SHS)technique as raw materials.The oxygen blocking mechanism of the ZrB_(2)-MoSi_(2) coatings at 1973 K was investigated.Compared with commercial powders,the coatings prepared by SHS powders exhibited superior density and inferior oxidation activity,which significantly heightened the structural oxygen blocking ability of the coatings in the active oxidation stage,thus characterizing higher oxidation protection efficiency.The rise of MoSi_(2) content facilitated the dispersion of transition metal oxide nanocrystals(5-20 nm)in the SiO_(2) glass layer and conduced to the increasing viscosity,thus strengthening the inerting impact of the compound glass layer in the inert oxidation stage.Nevertheless,the ZrB_(2)-40 vol% MoSi_(2) coating sample prepared by SHS powders presented the lowest oxygen permeability of 0.3% and carbon loss rate of 0.29×10^(6)g·cm^(-2)·s^(-1).Owing to the gradient oxygen partial pressure inside the coatings,the Si-depleted layer was developed under the compound glass layer,which brought about acute oxygen erosion.

Surface molecular imprinting on g-C3N4 photooxidative nanozyme for improved colorimetric biosensing

Graphitic carbon nitride(g-C3 N4),as a visible-light-active organic semiconductor,has attracted growing attentions in photocatalysis and photoluminescence-based biosensing.Here,we demonstrated the intrinsic photooxidase activity of g-C3 N4 and then surface molecular imprinting on g-C3 N4 nanozymes was achieved for improved biosensing.Upon blue LED irradiation,the g-C3 N4 exhibited superior enzymatic activity for oxidation of chromogenic substrate like 3,3’,5,5’-tetramethylbenzidine(TMB)without destructive H2 O2.The oxidation was mainly ascribed to ·O2^-that was generated during light irradiation.The surface molecular imprinting on g-C3 N4 can lead to an over 1000-fold alleviation in matrix-interference from serum samples,4-fold improved enzymatic activity as well as enhanced substrate specificity comparing with bare g-C3 N4 during colorimetric sensing.Also,the MIP-g-C3 N4 possesses a high affinity to TMB with a Km value of only 22 μmol/L,much lower than other comment nanozymes like AuNPs,Fe3 O4 NPs,etc.It was successfully applied for detection of cysteine in serum sample with satisfactory recoveries.

Heat Pumps in Denmark:Current Situation in Providing Frequency Control Ancillary Services

-The Danish government set an ambitious goal to achieve a fully renewable-based energy system by 2050.In this context,the integrated electricity and heating system is undergoing rapid development in Denmark as a promising way to accommodate the ever-growing renewable energy sources(RESs).The electric heat pumps(HPs),coupled with the power and heat sectors,can propagate the flexibility on the heat consumer side to the power system operations,playing an important role of improving system flexibility and balancing the variability of the RES.In this paper,the current development situation of HPs in Denmark is analyzed,including both the large-scale HPs in the district heating system and individual HPs on the residential side.The possibility of using HPs to provide frequency control ancillary service(FCAS)is analyzed according to the market and technical requirements of the FCAS in the Danish transmission system and experimental results of representative demonstration projects of HPs.A comprehensive analysis of the advantages,barriers,future prospects,and challenges for using HPs to provide the FCAS are carried out from the perspectives of different entities.