Effect Of Cu Ions Research Articles

Phenylthiourea enhances Cu cytotoxicity in cell cultures: Its mode of action.

PTU markedly enhanced the cytotoxic effects of CuCl2 on chick embryonic PECs cultured in vitro. We investigated this newly discovered effect of PTU and its analogues in relation to the toxic effects of Cu ion. Most PECs maintained in medium containing 0.5 mM PTU were lysed within 4 h by the addition of 0.1 mM CuCl2, which addition killed no PECs in the absence of PTU. The effect of PTU was not specific to PECs. All the cell lines tested, KB, N-18, N-115 and B-16, reacted against exogenous Cu in the presence of PTU as did the PECs. Analogues of PTU had effects on PECs similar to those on PTU in the presence of Cu ion. ANTU had a greater effect than PTU. MTU and TU had less effect than PTU. PTU did not affect the cytolysis induced by the addition of the divalent cations Mn, Co and Zn. About 6-fold the 64Cu-uptake by PECs was scored in the presence of PTU. The relation between this cytotoxic-enhancing effect and other biological activities of PTU are discussed.

Researches on the Corrosion of 18-8 Steel by the Aqueous Solution of Ammonium Sulphate, and its Prevention.

The corrosion of 18-8 steel by the aqueous solution of ammonium sulphate (NH4)2SO4, which often happens in industrial operation, and its protection are studied under various conditions. Results obtained are as follows:1. Temperature effects on the corrosionThe corrosion of 18-8 steel progresses slowly at below 80°C, but very rapidly when the temperature is raised above 90°C.2. Effects of (NH4)2SO4 concentration on the corrosion.When H2SO4 concentration is constant, the corrosion rate is lowered in proportion to the increase of (NH4)2SO4 content, and is minimized when it gets saturated.3. The corrosion of 18-8 modifications.Most of 18-8 modifications are more corrodible than ordinary 18-3 steel, except for 18-8 Mo., etc.4. The corrosion of higher stainless alloys to which Mo or Mo+Cu is added.18-12 Mo-Cu stainless alloy was found best against corrosion in the plant test.5. The corrosion of 18-8 steel in galvanizing operation.When 18-8 steel is in contact with lead (or bronze) in the liquor, corrosion of 18-8 steel (active) is accelerated. But when is in passive state, the rate of its corrosion is lowered, and the corrosion of lead (or bronze) is greatly accelerated in turn.6. Effects of Cu-ion on 18-8 corrosion:18-8 corrosion comes to a stop when more than 0.26% CuSO4 is added.7. Effect of As-ion on corrosion (carbon steel):Corrosion loss in weight is lowered to about 4.5% by addition of more than 0.3% Na3AsO4.