the chemistry of 2-oxo-1,2,3,4-tetrahydropyrimidines began to develop toward the end of 1893 year, when the first representatives of this class compounds were reported by p. biginelli. despite prior reports of several really effective catalytic and non-catalytic approaches towards biginelli-type products, an overwhelming number of new catalysts for the biginelli reaction have been recently publ...

an ultrasound-assisted surfactant-enhanced emulsification microextra- ction (uaseme) coupled with high performance liquid chromatography-diode array detection has been developed for the extraction and determination of thiopental in serum and urine samples. a simple microextraction method based on emulsification of organic extraction solvent in aqueous sample using an ionic surfactant and withou...

In a wild-type strain of Clostridium acetobutylicum isolated from soil, solvent production appeared limited by butanol toxicity. Butanol-resistant mutants have been obtained which produced significantly higher solvent concentrations (about 30%) than the wild-type strain. Some other physiological differences were observed between a selected resistant mutant and the wild-type strain at the level ...

The aim of the present study was to investigate the relationship between environmental vapor concentrations in organic solvent workplaces and size of enterprises, and to examine if occupational hygiene conditions were better in larger-scale enterprises. For this purpose, a total of 3,567 solvent workplaces were surveyed for environmental solvent vapor concentrations in 1999 to 2002. The results...

I use a Landau theory to study the behavior of A – B heteropolymers with disordered sequences immersed in a binary solvent mixture. Segments of type A are preferentially solvated in one type of solvent, and those of type B prefer the other type of solvent. At high temperatures, the behavior is qualitatively the same as that in a single solvent. As the temperature approaches the critical tempera...