Recent Developments in Calcium Alloy Cored Wire in Steel Production

The control of sulphides and oxides and desulphurisation by injection of calcium alloys in liquid steel is used with success in ladle now for many years. In the last years, technique of Ca alloys cored wire was developed as an alternative for inclusions control. A tehcnology using a wire, not welded with a large dia-meter is described so that feeder of the capstan type, making it possible to introduce big quantity of Ca alloys (SiCa-SiCaBa...) or other powdered products. This tech-nique is intended to small foundry ladles or big steel-works ladles as a tool to treat medium tonnages. Treatment in tundish of casters is also possible. Some results achieved in special steels for mechanical industry are given regarding mainly sulphides control by ladle addition

The Transcription Factor YY1 Is a Substrate for Polo-Like Kinase 1 at the G2/M Transition of the Cell Cycle

Yin-Yang 1 (YY1) is an essential multifunctional zinc-finger protein. It has been shown over the past two decades to be a critical regulator of a vast array of biological processes, including development, cell proliferation and differentiation, DNA repair, and apoptosis. YY1 exerts its functions primarily as a transcription factor that can activate or repress gene expression, dependent on its spatial and temporal context. YY1 regulates a large number of genes involved in cell cycle transitions, many of which are oncogenes and tumor-suppressor genes. YY1 itself has been classified as an oncogene and was found to be upregulated in many cancer types. Unfortunately, our knowledge of what regulates YY1 is very minimal. Although YY1 has been shown to be a phosphoprotein, no kinase has ever been identified for the phosphorylation of YY1. Polo-like kinase 1 (Plk1) has emerged in the past few years as a major cell cycle regulator, particularly for cell division. Plk1 has been shown to play important roles in the G/M transition into mitosis and for the proper execution of cytokinesis, processes that YY1 has been shown to regulate also. Here, we present evidence that Plk1 directly phosphorylates YY1 in vitro and in vivo at threonine 39 in the activation domain. We show that this phosphorylation is cell cycle regulated and peaks at G2/M. This is the first report identifying a kinase for which YY1 is a substrate