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The lamellar structure and weak interlayer shear force of graphene endow itself potential application value in lubrication fields, while its lubrication performance has been vastly investigated in various fields. However, there are few studies on the composite tribological performance of graphene and ceramic films. In this study, a solid–liquid lubricating system which TiN film slides in graphene aqueous dispersion is developed, aiming to achieve low friction of the TiN ceramic film in macroscale contact. Two kinds of TiN films were obtained by multi‐arc ion plating and magnetron sputtering respectively. The tribological test show that the friction coefficient of the TiN film drops when adding graphene aqueous dispersion and varies with the concentrations of graphene. The results indicate that the graphene might act in two ways to achieve low friction of TiN film, which are liquid lubricating effect of solvents and the formation of smooth sliding interface promoted by graphene. [ABSTRACT FROM AUTHOR]

In plant, a few 22-nt mi RNAs direct cleavages of their targets and trigger the biogenesis of phased small interfering RNAs (phasi RNAs) in plant. In this study, we characterized a mi RNA triggering phasi RNAs generation, miR3954, and explored its downstream target genes and potential function. Our results demonstrated that miR3954 showed specific expression in the flowers of citrus species, and it targeted a NAC transcription factor ( Cs7 g22460) and two non-coding RNA transcripts (lnc RNAs, Cs1 g09600 and Cs1 g09635). The production of phasi RNAs was detected from transcripts targeted by miR3954, and was further verified in both sequencing data and transient expression experiments. Phasi RNAs derived from the two lnc RNAs targeted not only miR3954-targeted NAC gene but also additional NAC homologous genes. No homologous genes of these two lnc RNAs were found in plants other than citrus species, implying that this miR3954-lnc RNAs-phasi RNAs- NAC pathway is likely citrus-specific. Transgenic analysis indicated that the miR3954-overexpressing lines showed decreased transcripts of lnc RNA, elevated abundance of phasi RNAs and reduced expression of NAC genes. Interestingly, the overexpression of miR3954 leads to early flowering in citrus plants. In summary, our results illustrated a model of the regulatory network of miR3954-lnc RNA-phasi RNAs- NAC, which may be functionally involved in flowering in citrus. [ABSTRACT FROM AUTHOR]

The tissue-specific transcription factorsHNF1α andHNF1β are closely related homeodomain proteins conserved in vertebrate evolution. Heterozygous mutations in human HNF1β but not in HNF1α genes are associated with kidney malformations. Overexpression of HNF1β in Xenopus embryos leads to defective pronephros development, while HNF1α has no effect. We have defined the regions responsible for this functional difference between HNF1β and HNF1α in transfected HeLa cells as well as in injected Xenopus embryos. Using domain swapping experiments, we located a nuclear localization signal in the POUH domain of HNF1β, and showed that the POUS and POUH domains of HNF1β mediate a high transactivation potential in transfected cells. In injected Xenopus embryos three HNF1β domains are involved in nephrogenesis. These include the dimerization domain, the 26 amino acid segment specific for splice variant A as well as the POUH domain. As HNF1β together with Pax8 and lim1 constitute the earliest regulators in the pronephric anlage, it is possible that they cooperate during early nephrogenesis. We have shown here that HNF1β can overcome the enlargement and the induction of an ectopic pronephros mediated by overexpression of Pax8 and lim1.However, the phenotype induced by Pax8 and lim1 overexpression and characterized by cyst-like structures and thickening of the pronephric tubules was not altered by HNF1β overexpression. Taken together, HNF1β acts antagonistically to Pax8 and lim1 in only some processes during nephrogenesis, and a simple antagonistic relationship does not completely describe the functions of these genes. We conclude that HNF1β has some distinct morphogenetic properties during nephrogenesis. [ABSTRACT FROM AUTHOR]