Hydrogels exhibit promising applications,particularly due to their high water content and excellent biocompatibility.Despite notable progress in hydrogel technology,the concurrent enhancement of water content,mechanic...Hydrogels exhibit promising applications,particularly due to their high water content and excellent biocompatibility.Despite notable progress in hydrogel technology,the concurrent enhancement of water content,mechanical strength,and low friction poses substantial challenges to practical utilization.In this study,employing molecular and network design guided based on multiple synergistic enhancement mechanisms,we have developed a robust polyvinyl alcohol(PVA)-polyacrylic acid(PAA)-polyacrylamide(PAAm)three-network(TN)hydrogel exhibiting high water content,enhanced strength,low friction,and fatigue resistance.The hydrogel manifests a water content of 63.7%,compression strength of 6.3 MPa,compression modulus of 2.68 MPa,tensile strength reaching 7.3 MPa,and a tensile modulus of 10.27 MPa.Remarkably,even after one million cycles of dynamic loading,the hydrogel exhibits no signs of fatigue failure,with a minimal strain difference of only 1.15%.Furthermore,it boasts a low sliding coefficient of friction(COF)of 0.043 and excellent biocompatibility.This advancement extends the applications of hydrogels in emerging fields within biomedicine and soft bio-devices,including load-bearing artificial tissues,artificial blood vessels,tissue scaffolds,robust hydrogel coatings for medical devices,and joint parts of soft robots.展开更多
Nitrogen(N)deposition and intensified rainfall can strongly affect soil microbial community,but compared with available studies on bacteria,those on soil fungi are quite limited.Here we carried out a field experiment ...Nitrogen(N)deposition and intensified rainfall can strongly affect soil microbial community,but compared with available studies on bacteria,those on soil fungi are quite limited.Here we carried out a field experiment in a mixed deciduous forest of China to study the influences of increased N deposition and rainfall on soil fungi by using quantitative PCR and high-throughput sequencing method.The results demonstrated that(1)N addition significantly increased fungal abundance and alpha diversity(richness,Shannon index and Invsimpson index),changed fungal community composition at OTU level,and marginally increased the relative abundance of Ascomycota and Zygomycota,while water addition showed no remarkable effects on fungal abundance,biodiversity and community composition.(2)N addition significantly increased the richness of saprotrophic fungi and pathogenic fungi,and the relative abundance of saprotrophic fungi,but water addition only slightly increased the abundance of pathogenic fungi.(3)Fungal composition dissimilarity closely correlated with the disparity of soil parameters as a whole.Soil NH_(4)^(+)-N exhibited strong positive correlation with the richness of pathogenic fungi and mycorrhizal fungi,while both soil moisture and NH_(4)^(+)-N tightly correlated with soil fungal abundance and alpha diversity indices.We concluded that in this N-limited but non-water-limited forest ecosystem,N deposition posed stronger effects on soil fungi than increased rainfall,partially mediated by changes in soil properties.展开更多
基金supported by Jiangsu Provincial Key Research and Development Program(No.BE2022708)Natural Science Foundation of Jiangsu Province(No.BK20211243).
文摘Hydrogels exhibit promising applications,particularly due to their high water content and excellent biocompatibility.Despite notable progress in hydrogel technology,the concurrent enhancement of water content,mechanical strength,and low friction poses substantial challenges to practical utilization.In this study,employing molecular and network design guided based on multiple synergistic enhancement mechanisms,we have developed a robust polyvinyl alcohol(PVA)-polyacrylic acid(PAA)-polyacrylamide(PAAm)three-network(TN)hydrogel exhibiting high water content,enhanced strength,low friction,and fatigue resistance.The hydrogel manifests a water content of 63.7%,compression strength of 6.3 MPa,compression modulus of 2.68 MPa,tensile strength reaching 7.3 MPa,and a tensile modulus of 10.27 MPa.Remarkably,even after one million cycles of dynamic loading,the hydrogel exhibits no signs of fatigue failure,with a minimal strain difference of only 1.15%.Furthermore,it boasts a low sliding coefficient of friction(COF)of 0.043 and excellent biocompatibility.This advancement extends the applications of hydrogels in emerging fields within biomedicine and soft bio-devices,including load-bearing artificial tissues,artificial blood vessels,tissue scaffolds,robust hydrogel coatings for medical devices,and joint parts of soft robots.
基金financially supported by the Natural Science Foundation of Jiangsu Province(BK20211243)Jiangsu Provincial Key Research and Development Program(BE2022708)+1 种基金the Tribology Science Fund of State Key Laboratory of Tribology in Advanced Equipment(SKLTKF21B15)the Open Fund of State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics(LSL-2107).
基金supported by the National Natural Science Foundation of China(41877050,31300446,41401286).
文摘Nitrogen(N)deposition and intensified rainfall can strongly affect soil microbial community,but compared with available studies on bacteria,those on soil fungi are quite limited.Here we carried out a field experiment in a mixed deciduous forest of China to study the influences of increased N deposition and rainfall on soil fungi by using quantitative PCR and high-throughput sequencing method.The results demonstrated that(1)N addition significantly increased fungal abundance and alpha diversity(richness,Shannon index and Invsimpson index),changed fungal community composition at OTU level,and marginally increased the relative abundance of Ascomycota and Zygomycota,while water addition showed no remarkable effects on fungal abundance,biodiversity and community composition.(2)N addition significantly increased the richness of saprotrophic fungi and pathogenic fungi,and the relative abundance of saprotrophic fungi,but water addition only slightly increased the abundance of pathogenic fungi.(3)Fungal composition dissimilarity closely correlated with the disparity of soil parameters as a whole.Soil NH_(4)^(+)-N exhibited strong positive correlation with the richness of pathogenic fungi and mycorrhizal fungi,while both soil moisture and NH_(4)^(+)-N tightly correlated with soil fungal abundance and alpha diversity indices.We concluded that in this N-limited but non-water-limited forest ecosystem,N deposition posed stronger effects on soil fungi than increased rainfall,partially mediated by changes in soil properties.
