Background Sex hormones play important roles in the estrus return of post-weaning sows.Previous studies have demonstrated a complex and bi-directional regulation between sex hormones and gut microbiota.However,the ext...Background Sex hormones play important roles in the estrus return of post-weaning sows.Previous studies have demonstrated a complex and bi-directional regulation between sex hormones and gut microbiota.However,the extent to which the gut microbiota affects estrus return of post-weaning sows is largely unknown.Results In this study,we first screened 207 fecal samples from well-phenotyped sows by 16S rRNA gene sequencing and identified significant associations between microbes and estrus return of post-weaning sows.Using metagenomic sequencing data from 85 fecal samples,we identified 37 bacterial species that were significantly associated with estrus return.Normally returning sows were characterized by increased abundances of L.reuteri and P.copri and decreased abundances of B.fragilis,S.suis,and B.pseudolongum.The changes in gut microbial composition significantly altered the functional capacity of steroid hormone biosynthesis in the gut microbiome.The results were confirmed in a validation cohort.Significant changes in sex steroid hormones and related compounds were found between normal and non-return sows via metabolome analysis.An integrated analysis of differential bacterial species,metagenome,and fecal metabolome provided evidence that normal return-associated bacterial species L.reuteri and Prevotella spp.participated in the degradation of pregnenolone,progesterone,and testosterone,thereby promoting estrogen biosynthesis.Furthermore,the microbial metabolites related to sow energy and nutrient supply or metabolic disorders also showed relationships with sow estrus return.Conclusions An integrated analysis of differentially abundant bacterial species,metagenome,and fecal metabolome revealed the involvement of L.reuteri and Prevotella spp.in sow estrus return.These findings provide deep insight into the role of gut microbiota in the estrus return of post-weaning sows and the complex cross-talk between gut microbiota and sex hormones,suggesting that the manipulation of the gut microbiota could be an effective strategy to improve sow estrus return after weaning.展开更多
Tri-post insulators in gas-insulated transmission line(GIL)are usually fabricated with high mass fraction of micron aluminum oxide(Al_(2)O_(3)),which will unavoidably settle under the action of gravity during the prep...Tri-post insulators in gas-insulated transmission line(GIL)are usually fabricated with high mass fraction of micron aluminum oxide(Al_(2)O_(3)),which will unavoidably settle under the action of gravity during the preparation process and seriously affect the uniformity.A model of filler sedimentation in epoxy resin composite materials was proposed based on the particle size analysis and Stokes'Law.Some scaled tri-post insulators were prepared and tested by slicing.It is determined that the position of density concentration is the lower side of the two lower posts and the upper interface between the insulator and the conductor.The density ranges from 2.144 to 2.346 g/cm^(3).The dynamic fracture simulation model of insulator was established and it is found that the insulator fracture occurs at the interface of upper post/insert under radial load,which is verified by experiments.By comparing the influence of sprue position on the density distribution,it is found that the uniformity of insulators is increased by 13.7% by forward pouring compared with reverse pouring.This research develops an accurate method for simulating the filler sedimentation and the fracture process in epoxy-based insulators,which is helpful for the improvement of mechanical reliability of GIL.展开更多
基金supported by the National Key R&D Program of China(2022YFA1304204)National Natural Science Foundation of China(31772579).
文摘Background Sex hormones play important roles in the estrus return of post-weaning sows.Previous studies have demonstrated a complex and bi-directional regulation between sex hormones and gut microbiota.However,the extent to which the gut microbiota affects estrus return of post-weaning sows is largely unknown.Results In this study,we first screened 207 fecal samples from well-phenotyped sows by 16S rRNA gene sequencing and identified significant associations between microbes and estrus return of post-weaning sows.Using metagenomic sequencing data from 85 fecal samples,we identified 37 bacterial species that were significantly associated with estrus return.Normally returning sows were characterized by increased abundances of L.reuteri and P.copri and decreased abundances of B.fragilis,S.suis,and B.pseudolongum.The changes in gut microbial composition significantly altered the functional capacity of steroid hormone biosynthesis in the gut microbiome.The results were confirmed in a validation cohort.Significant changes in sex steroid hormones and related compounds were found between normal and non-return sows via metabolome analysis.An integrated analysis of differential bacterial species,metagenome,and fecal metabolome provided evidence that normal return-associated bacterial species L.reuteri and Prevotella spp.participated in the degradation of pregnenolone,progesterone,and testosterone,thereby promoting estrogen biosynthesis.Furthermore,the microbial metabolites related to sow energy and nutrient supply or metabolic disorders also showed relationships with sow estrus return.Conclusions An integrated analysis of differentially abundant bacterial species,metagenome,and fecal metabolome revealed the involvement of L.reuteri and Prevotella spp.in sow estrus return.These findings provide deep insight into the role of gut microbiota in the estrus return of post-weaning sows and the complex cross-talk between gut microbiota and sex hormones,suggesting that the manipulation of the gut microbiota could be an effective strategy to improve sow estrus return after weaning.
基金Science and Technology Project of SGCC,Grant/Award Number:SGSDJX00YJJS2100206。
文摘Tri-post insulators in gas-insulated transmission line(GIL)are usually fabricated with high mass fraction of micron aluminum oxide(Al_(2)O_(3)),which will unavoidably settle under the action of gravity during the preparation process and seriously affect the uniformity.A model of filler sedimentation in epoxy resin composite materials was proposed based on the particle size analysis and Stokes'Law.Some scaled tri-post insulators were prepared and tested by slicing.It is determined that the position of density concentration is the lower side of the two lower posts and the upper interface between the insulator and the conductor.The density ranges from 2.144 to 2.346 g/cm^(3).The dynamic fracture simulation model of insulator was established and it is found that the insulator fracture occurs at the interface of upper post/insert under radial load,which is verified by experiments.By comparing the influence of sprue position on the density distribution,it is found that the uniformity of insulators is increased by 13.7% by forward pouring compared with reverse pouring.This research develops an accurate method for simulating the filler sedimentation and the fracture process in epoxy-based insulators,which is helpful for the improvement of mechanical reliability of GIL.
