Some 5-aryl-2-mercapto-1,3,4-oxadiazole (I) reacted with maleic anhydride, maleic acid and p-benzoquinone affording 2-(5-aryl-1,3,4-oxadiazol-2-ylthio)succinic anhydrides (II), 2-(5-aryl-1,3,4-oxadiazol-2-ylthio)succinic acids (III) and 2-(2,5-dihydroxyphenylthio)-5-aryl-l,3,4-oxadiazoles (IV), respectively. Treatment of 2-methylthio-5-phenyl-l,3-oxadiazole (V) with amines gives 2-[(alkyl or ar...

Fundamental to the processes of decalcification of or adhesion to mineralized tissues is the molecular interaction of acids with hydroxyapatite. This study was undertaken to chemically analyze the interaction of 1 mono-, 2 di-, 1 tri-, and 2 polycarboxylic acids with hydroxyapatite in an attempt to elucidate the underlying mechanism. Maleic, citric, and lactic acid decalcified hydroxyapatite, i...

Study on the effects of sonolysis, ozonolysis and US/O3 system on the decomposition of p-chlorophenol in aqueous solutions indicated that in the cases of US/O3 system, individual ozonolysis and sonolysis, the decomposition rate of p-chlorophenol reached 78.78%, 56.20%, 2.79% after a 16-min reaction while its CODcr (chemical oxygen demand) removal rate was 97.02%, 62.17%, 3.67% after a 120-min r...

Aim. Physicochemical mechanical and in vitro biological properties of novel formulations of polymeric calcium phosphate cements (CPCs) were investigated. Methods. Monocalcium phosphate, calcium oxide, and synthetic hydroxyapatite were combined with either modified polyacrylic acid, light activated polyalkenoic acid, or polymethyl vinyl ether maleic acid to obtain Types I, II, and III CPCs. Sett...

This work succeeded in synthesizing sponges from chitosan-graft-maleic anhydride. Chitosan and maleic anhydride at a certain mass ratio (1:2, 1:1; 2:1) were reacted dimethyl sulfoxide (DMSO) 60

Malic acid was first isolated by Carl Wilhelm Scheele from apple juice in 1785. Scheele was born in 1742 in Stralsund. The German seaport of Stralsund is situated on the southern coast of a sound of the Baltic Sea that separates the island of Rügen from the mainland. This small town remained under Swedish control until 1815, when it became a part of the Prussian Province of Pomerania. Thus, Sch...