RESUMO
Silica is widely used in industrial applications and its performance is partially decided by its surface hydroxyl density αOH. Here we report a quick, simple liquid 1H NMR method to determine αOH using a benchtop 1H NMR spectrometer. The results show excellent agreement with the literature with an αOH range from 4.16 to 6.56 OH per nm2.
RESUMO
Las malformaciones adenomatoideas congénitas pulmonares son una anomalía fetal rara. Presentamos seis casos diagnosticados in útero. Los criterios diagnósticos y pronósticos son claramente tratados.
Assuntos
Feminino , Gravidez , Humanos , Malformação Adenomatoide Cística Congênita do Pulmão , Diagnóstico Diferencial , Doenças do Mediastino/etiologia , Hidropisia Fetal/etiologia , Hidropisia Fetal , Malformação Adenomatoide Cística Congênita do Pulmão/classificação , Malformação Adenomatoide Cística Congênita do Pulmão/complicações , Malformação Adenomatoide Cística Congênita do Pulmão/terapia , Prognóstico , Ultrassonografia Pré-NatalRESUMO
2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (II), a cyclic metabonate of methadone was synthesized from methadone (I) and methadone-N-oxide (III). M-Chloroperbenzoic acid was used to oxidatively demethylate I while sulphur dioxide reductively demethylated III to give II. The importance of these syntheses lies in the fact that there is no attack on the asymmetric carbon atom in I or III, thus providing direct methods of obtaining the optical isomers of II.