Activation of astrocytes of by anaphylatoxins of the complement system

It has been shown that astrocytes (human glioblastoma U118 cell line) release reactive oxygen species (ROS), including superoxide O2.- and hydrogen peroxide H2O2 following the action of C5a complement component C5a (but not C3a). The effect of C5a (1 nM) is accompanied with hyperpolarization of the astrocyte plasma membrane. Component C3a (100 nM), which is not an inducer of ROS, caused a prolonged depolarization of astrocytes. However, both the agents induced a transient increase in intracellular Ca2+ concentration. The data obtained permit a conclusion that O2.- participates in the intracellular signal transduction, and is involved in the mechanism of hyperpolarization response of astrocytes to the effect of the inducer of ROS, complement component C5a.     

A mullite compound for combined lining of steel teeming ladles

Conclusions For ramming of the walls in combined lining of the 350-ton steel teeming ladles of Azov Steel Combine a composition and method of preparation of a mullite ramming compound applicable to the existing production conditions of Velikoanadol Refractory Combine has been developed.The use of the mullite compound produced by Velikoanadol Combine provided an average life of the ladle combined lining of 20 pourings with a maximum of 37 pourings.To reduce the cost of production the possibility was established of partial replacement in the composition of Kazakh Refractory Plant Electrocorundum by Zaporozhe Abrasive Plant slurry wastes of normal electrocorundum.DISCUSSION: Problems of the Production and Use of Refractories for Lining Steel Teeming Ladles [for the start of the discussion see No. 8, 1988 and for the continuation Nos. 9–12, 1988 and Nos. 1–2, 1989].Translated from Ogneupory, No. 3, pp. 1–4, March, 1989.     

Analysis of factors affecting the results of electromagnetic acoustic inspection of hot metal

Experiments are performed to reveal model flaws in a hot metal. The effect of the metal temperature, the gap between an electromagnetic-acoustical transducer (EMAT) and an article, the magnitude and distribution of the induction component of the polarizing magnetic field, and weakening of longitudinal vibrations in the hot metal on the results of testing by shear and longitudinal waves are studied.Translated from Defektoskopiya, Vol. 40, No. 11, 2004, pp. 40–49.Original Russian Text Copyright © 2004 by Sebko, Suchkov, Ishchenko.     

Cracking resistance in high-tensile AMg6 NPP, 1201, and 1420 aluminum alloys and welded joints in them

Summary The carrying capacity has been determined for high-tensile aluminum alloys AMg6 NPP, 1201, and 1420 along with welded joints, which have been tested on three types of specimen: cylindrical ones with ring cracks in axial tension, rectangular ones with side cracks in three-point bending, and compact ones with side cracks in off-center tension.The welded joints have 30–40% less cracking resistance in the melted zones than in the initial material, no matter what the type of specimen and loading schme. The maximum cracking resistance occurs in 1420 alloy, whose more homogeneous structure is provided by optimizing the composition, but it has minimum plasticity margin relative to AMg6 NPP and 1201, as this is determined by the relation between the strength parameters.Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 26, No. 3, pp. 122–123, May–June, 1990.