Investigation of the processes of obtaining plastic treatment and electrochemical behaviour of lead alloys in their capacity as anodes during the electroextraction of zinc II. Electrochemical formation of phase layers on binary PbAg and PbCa, and ternary PbAgCa alloys in a sulphuric-acid electrolyte for zinc electroextraction

The electrochemical oxidation processes and phase formation on binary PbAg and PbCa, and ternary PbAgCa alloys during anodic treatment of the electrodes for conditions in a sulphuric acid electrolyte were investigated.The electrochemical behaviour of lead and its alloys was studied by the cyclic voltammetry method (CVA). X-ray and SEM were used for the phase composition and surface structure analysis. It was established that only the ternary plastically treated PbAg 0.5%-Ca 0.11% alloys reveal similarities to the industrially applied PbAg 1 % anodes. It may be assumed in the case of ternary alloys that the catalytic layer is composed of a dense non-conductive MnO₂ layer of crystals serving as basic sites for oxygen evolution.     

Effect of saccharose and sorbit on indices of carbohydrate metabolism in mixed saliva of patients with diabetes mellitus and dental caries

The content of lactate in mixed saliva in severe diabetes mellitus associated with multiple caries was 5 times and in diabetes of medium severity 3.5 times greater than in caries-resistant subjects. This increase was largely caused by diabetes proper, since in multiple caries without diabetes, the lactate content was increased only 2-fold. The amount of pyruvate in saliva in multiple caries without diabetes was approximately the same as that in diabetes mellitus coupled with multiple caries. Preliminary administration to the oral cavity of 100 ml of 50% saccharose for 10 minutes (without swallowing) raised the saliva lactate content several times as compared to that in the same subjects before saccharose administration. The lactate content in saliva was particularly high in severe diabetes mellitus. Administration of 50% sorbitol of the oral cavity for 10 minutes did not increase the lactate content in saliva. Upon administration of saccharose lactate dehydrogenase activity in saliva significantly descended while sorbitol dehydrogenase activity significantly increased. Administration of sorbitol solution to the oral cavity did not produce any essential effect on sorbitol dehydrogenase activity in saliva.