naphthol isomers were simultaneously and spectrophotometrically determined in wastewater, using a model based on net analyte signal (nas). the calibration method used is a variation of the original hybrid linear analysis method as proposed by goicoechea and olivieri (hla/go). owing to spectral interferences, the simultaneous determination of mixtures of naphthol isomers, using a spectrophotomet...

The structure and stability of ca. 100 nonplanar constitutional isomers of the coronene molecule of general formula C(24)H(12) have been estimated by semiempirical and by ab initio calculations. The isomers studied are unbranched cyclic catacondensed structures and fall into two classes, viz., the belt (B) and the Moebius (M) type. The calculations have shown some of the M-isomers to be more st...

Prasugrel, a thienopyridine antiplatelet drug, is converted in animals and humans to the pharmacologically active metabolite R-138727 [(2Z)-{1-[(1RS)-2-cyclopropyl-1-(2-fluorophenyl)-2-oxoethyl]4-sulfanylpiperidin-3-ylidene}ethanoic acid], which has two chiral centers, occurring as a mixture of four isomers. The RS and RR isomers are more active than the SS and SR isomers (RS > RR > > SR = SS)....

Difenacoum, an antivitamin K anticoagulant, has been widely used as rodenticide to manage populations of rodents. Difenacoum belongs to the second generation of anticoagulant, and, as all the molecules belonging to the second generation of anticoagulant, difenacoum is often involved in primary poisonings of domestic animals and secondary poisonings of wildlife by feeding contaminated rodents. T...

Nonylphenol belongs to the most investigated xenohormones acting at the estrogen receptor. Technical nonylphenol contains approximately 20 para-substituted isomers. Because of limitations in testing and quantifying all 20 isomers in the mixture, the linear form, 4n-NP, is often used as a reference substance, even though it is not present in the technical mixture. Here, we report on the synthesi...

For the first time, relative distributions of optical and geometrical isomers in selected propylene glycol acetals are determined. Resolution of the four acetal isomers possible through the reaction of racemic propylene glycol (PG) with selected aldehydes is demonstrated. The four isomers are ascribed to the presence of syn and anti geometrical isomers for each optically active PG acetal enanti...

objective(s): non-syndromic sensorineural hearing loss (nshl) is a common disorder affecting approximately 1 in 500 newborns. this type of hearing loss is extremely heterogeneous and includes over 100 loci. mutations in the gjb2 gene have been implicated in about half of autosomal recessive nshl (arnshl) cases, making this the most common cause of arnshl. for the latter form of deafness, most f...