A comparative analysis of double inversion recovery TFE and TSE sequences on carotid artery wall imaging.

Objective: To analyze the characteristics of double inversion recovery (DIR) turbo field echo (TFE) and turbo spin echo (TSE) sequences and explore the value of double inversion recovery TFE sequence on carotid artery wall imaging.

Patients And Methods: 56 patients (32 males and 24 females, aged 31-76 years with a mean age of 53 years) were performed with DIR TFE and DIR TSE T1 weighted imaging (T1WI) sequences on carotid artery bifurcations. Image quality acquired by different techniques were evaluated and scored by two physicians.

Selective approach toward multifunctionalized lactams by lewis acid promoted PhSe group transfer radical cyclization.

We have developed a regiospecific and highly stereoselective strategy for constructing the five-/six-membered monocyclic and bicyclic nitrogen heterocycle skeletons using PhSe group transfer radical cyclization of alpha-phenylseleno amido esters promoted by a Lewis acid (e.g., Yb(OTf)(3)) under UV irradiation.

Synthesis of gamma-butyrolactams by photoinduced PhSe group transfer radical cyclization and formal synthesis of (+/-)-isocynometrine with diphenyldiselenide as promoter.

We have developed a strategy for constructing nitrogen heterocycles by photoinduced PhSe group transfer radical cyclization. trans-Alpha,beta-disubstituted gamma-butyrolactams (2-pyrrolidinones) were prepared in good yields (38-73%) with high regioselectivity and stereoselectivity from N-alkenyl alpha-PhSe beta-keto amides. Reaction outcomes were modulated by the steric effect of the substituents on the nitrogen atom of the cyclization precursors and the stereoelectronic effect of the substrates.