Yu Ito

Foxo1 increases pro-inflammatory gene expression by inducing C/EBPβ in TNF-α-treated adipocytes

Obesity is associated with a low-grade inflammation in adipose tissue resulting from increased production of pro-inflammatory cytokines and which can subsequently contribute to the development of insulin resistance. However, the mechanisms underlying the transcriptional regulation of pro-inflammatory genes are still unclear. Here we show that tumor necrosis factor (TNF)-alpha treatment attenuated Akt-dependent phosphorylation of Foxo1 and enhanced transcriptional activity of Foxo1. We found that Foxo1 increased the expression of CCAAT/enhancer binding protein (C/EBPbeta, a positive regulator of monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-6 genes, through directly binding to its promoter. Furthermore, knockdown of Foxo1 as well as C/EBPbeta inhibits TNF-alpha-induced expression of MCP-1 and IL-6 in 3T3-L1 adipocytes. These findings suggest that activation of Foxo1 triggered by TNF-alpha up-regulates the expression of C/EBPbeta in 3T3-L1 adipocytes, thereby leading to an increased production of pro-inflammatory cytokines, MCP-1 and IL-6.

Effect of metal contact on electron transport and its removal in graphene field effect devices

Effect of metal contact on the transfer characteristics in graphene field effect devices is studied for several metal species. We find that two Dirac points appear in the transfer characteristics: one corresponding to the graphene portion underneath/near the contact and the other to the graphene portion far from the contact. The difference in the gate voltages of the these Dirac points correlates with the work function of the contact metal, clearly showing that the additional Dirac point originates from the carrier doping from the contact metal. This carrier doping effect is successfully removed by inserting multilayer graphene between metal and graphene, without significantly increasing the contact resistance.

Cepstrum Analysis Applied to Ultrasonic Reflection Wave Detection Wave Method to Investigate the Depth and the Damage of the Pile

In civil engineering, especially in construction sites, it is essential to investigate the degree of damage and the depth of foundation piles and pillars. Ultrasonic wave and elastic impact wave methods are currently used as typical non-destructive testing methods to be applied to a concrete object such as a foundation pile for construction. The latter is performed with using a hammer as its input making this method inaccurate and hard to obtain the same result each time. Therefore, ultrasonic measurement method was chosen over elastic impact wave method to be applied in this study. However, by using the conventional ultrasonic measurement method, since the input is very small, the depth of the investigation is very shallow. Therefore, if it becomes possible to input ultrasonic wave vibration into the concrete foundation pile, deeper depth investigation with higher precision will be attained. In this study, ultrasonic reflection wave detection method was used in order to measure the length of the pile and to detect the degree of damage in the pile