Analysis and Prediction Model Reinforced UHPC Shrinkage Property

This paper explores the shrinkage of reinforced UHPC under high-temperature steam curing and natural curing conditions.The results are compared with the existing shrinkage prediction models.The results show that the maximum shrinkage strain of reinforced UHPC after steam curing is 164μεand gradually becomes zero.As for natural curing,the maximum shrinkage strain is 173μεand the value stabilizes on the 10th day after pouring.This indicated that steam curing can significantly reduce shrinkage time.Compared with the plain UHPC tested in the previous literature,the structural reinforcement can significantly inhibit the UHPC shrinkage and greatly reduce the risk of cracking due to shrinkage.By comparing the results in this paper with the existing models for predicting the shrinkage strain development,it is found that the formula recommended in the French UHPC structural and technical specification is suitable for the shrinkage curve in the present paper.

甲壳素纳米纤维/碳纳米管复合凝胶膜的制备与性能

将甲壳素纳米纤维与碳纳米管在水性条件下混合,建立甲壳素纳米纤维均匀分散的碳纳米管混合体系;利用真空抽滤制备甲壳素纳米纤维/碳纳米管复合膜,通过20%氢氧化钠低温处理制备具有连续三维纳米网络结构的复合凝胶膜,并对比凝胶化前后样品微观结构、导电性能及电化学性能等。结果表明,凝胶化处理有助于在凝胶膜内部构建三维纳米导电网络,当甲壳素纳米纤维与碳纳米管的质量比为1∶1时,凝胶膜的导电率和质量比电容较复合膜提高了2倍;2000次循环测试后,凝胶膜的比电容量仍能保持为起始比电容量的92.5%,循环稳定性较好。

Crosstalk between adipose-derived stem cells and chondrocytes:when growth factors matter

Adipose-derived stem cells（ASCs）and mesenchymal stem cells are promising for tissue repair because of their multilineage differentiation capacity.Our previous data confirmed that the implantation of mixed ASCs and chondrocytes into cartilage defects induced desirable in vivo healing outcomes.However,the paracrine action of ASCs on chondrocytes needs to be further elucidated.In this study,we established a co-culture system to achieve cell-to-cell and cell-to-tissue crosstalk and explored the soluble growth factors in both ASCs and chondrocytes supplemented with 1%fetal bovine serum to mimic the physiological microenvironment.In ASCs,we screened for growth factors by semi-quantitative PCR and quantitative real-time PCR and found that the expression of bone morphogenetic protein 2（BMP-2）,vascular endothelial growth factor B（VEGFB）,hypoxia inducible factor-1α（HIF-1α）,fibroblast growth factor-2（FGF-2）,and transforming growth factor-β1 significantly increased after co-culture in comparison with mono-culture.In chondrocytes,VEGFA was significantly enhanced after co-culture.Unexpectedly,the expression of collagen II and aggrecan was significantly down-regulated in the co-culture group compared with the mono-culture group.Meanwhile,among all the growth factors screened,we found that the BMP family members BMP-2,BMP-4,and BMP-5 were down-regulated and that VEGFB,HIF-1α,FGF-2,and PDGF were significantly decreased after co-culture.These results suggest that crosstalk between ASCs and chondrocytes is a pathway through the regulated growth factors that might have potential in cartilage repair and regeneration and could be useful for tissue engineering.

Proposed nomenclature for Pseudallescheria,Scedosporium and related genera

As a result of fundamental changes in the International Code of Nomenclature on the use of separate names for sexual and asexual stages of fungi,generic names of many groups should be reconsidered.Members of the ECMM/ISHAM working group on Pseudallescheria/Scedosporium infections herein advocate a novel nomenclature for genera and species in Pseudallescheria,Scedosporium and allied taxa.The generic names Parascedosporium,Lomentospora,Petriella,Petriellopsis,and Scedosporium are proposed for a lineage within Microascaceae with mostly Scedosporium anamorphs producing slimy,annellidic conidia.Considering that Scedosporium has priority over Pseudallescheria and that Scedosporium prolificans is phylogenetically distinct from the other Scedosporium species,some name changes are proposed.Pseudallescheria minutispora and Petriellidium desertorum are renamed as Scedosporium minutisporum and S.desertorum,respectively.Scedosporium prolificans is renamed as Lomentospora prolificans.

A re-evaluation of the Chaetothyriales using criteria of comparative biology

Chaetothyriales is an ascomycetous order within Eurotiomycetes.The order is particularly known through the black yeasts and filamentous relatives that cause opportunistic infections in humans.All species in the order are consistently melanized.Ecology and habitats of species are highly diverse,and often rather extreme in terms of exposition and toxicity.Families are defined on the basis of evolutionary history,which is reconstructed by time of divergence and concepts of comparative biology using stochastical character mapping and a multi-rate Brownian motion model to reconstruct ecological ancestral character states.Ancestry is hypothesized to be with a rock-inhabiting life style.Ecological disparity increased significantly in late Jurassic,probably due to expansion of cytochromes followed by colonization of vacant ecospaces.Dramatic diversification took place subsequently,but at a low level of innovation resulting in strong niche conservatism for extant taxa.Families are ecologically different in degrees of specialization.One of the clades has adapted ant domatia,which are rich in hydrocarbons.In derived families,similar processes have enabled survival in domesticated environments rich in creosote and toxic hydrocarbons,and this ability might also explain the pronounced infectious ability of vertebrate hosts observed in these families.Conventional systems of morphological classification poorly correspond with recent phylogenetic data.Species are hypothesized to have low competitive ability against neighboring microbes,which interferes with their laboratory isolation on routine media.The dataset is unbalanced in that a large part of the extant biodiversity has not been analyzed by molecular methods,novel taxonomic entities being introduced at a regular pace.Our study comprises all available species sequenced to date for LSU and ITS,and a nomenclatural overview is provided.A limited number of species could not be assigned to any extant family.

Precast steel—UHPC lightweight composite bridge for accelerated bridge construction

In this study,a fully precast steel—ultrahigh performance concrete(UHPC)lightweight composite bridge(LWCB)was proposed based on Mapu Bridge,aiming at accelerating construction in bridge engineering.Cast-in-place joints are generally the controlling factor of segmental structures.Therefore,an innovative girder-to-girder joint that is suitable for LWCB was developed.A specimen consisting of two prefabricated steel—UHPC composite girder parts and one post-cast joint part was fabricated to determine if the joint can effectively transfer load between girders.The flexural behavior of the specimen under a negative bending moment was explored.Finite element analyses of Mapu Bridge showed that the nominal stress of critical sections could meet the required stress,indicating that the design is reasonable.The fatigue performance of the UHPC deck was assessed based on past research,and results revealed that the fatigue performance could meet the design requirements.Based on the test results,a crack width prediction method for the joint interface,a simplified calculation method for the design moment,and a deflection calculation method for the steel—UHPC composite girder in consideration of the UHPC tensile stiffness effect were presented.Good agreements were achieved between the predicted values and test results.