Reductive C-C Coupling from α,β-Unsaturated Nitriles by Intercepting Keteniminates.

We present an atom-economic strategy to catalytically generate and intercept nitrile anion equivalents using hydrogen transfer catalysis. Addition of α,β-unsaturated nitriles to a pincer-based Ru-H complex affords structurally characterized κ-N-coordinated keteniminates by selective 1,4-hydride transfer. When generated in situ under catalytic hydrogenation conditions, electrophilic addition to the keteniminate was achieved using anhydrides to provide α-cyanoacetates in high yields.

Controlling Interfacial Dynamics: Covalent Bonding versus Physical Adsorption in Polymer Nanocomposites.

It is generally believed that the strength of the polymer-nanoparticle interaction controls the modification of near-interface segmental mobility in polymer nanocomposites (PNCs). However, little is known about the effect of covalent bonding on the segmental dynamics and glass transition of matrix-free polymer-grafted nanoparticles (PGNs), especially when compared to PNCs. In this article, we directly compare the static and dynamic properties of poly(2-vinylpyridine)/silica-based nanocomposites with polymer chains either physically adsorbed (PNCs) or covalently bonded (PGNs) to identical silica nanoparticles (RNP = 12.

Low-voltage aEEG as predictor of intracranial hemorrhage in preterm infants.

The objectives of this prospective cohort study were to identify amplitude-integrated electroencephalography (aEEG) background patterns predictive of severe intracranial hemorrhage. Thirty ventilated preterm newborns weighing <1,000 g were assessed by an aEEG cerebral function monitor and ultrasound measurement of cerebral blood flow velocity at time of surfactant administration and tracheal suctioning simultaneously during first 48 hours of life. Birth weight was 624 ± 200 g (mean ± S.

Stable isotopes of pedogenic carbonates as indicators of paleoecology in the Plio-Pleistocene (upper Bed I), western margin of the Olduvai Basin, Tanzania.

Paleosol carbonates from trenches excavated as part of a landscape-scale project in Bed I of Olduvai Gorge, Tanzania, were analyzed for stable carbon and oxygen isotopic composition. The approximately 60,000-year interval ( approximately 1.845-1.

Effects of mode of delivery on mortality and severe brain injury in extremely low birth weight infants in Arkansas.

The optimal mode of delivery for extremely low birth weight (ELBW) infants remains unknown. We reviewed the medical records of 374 ELBW infants (gestational age 23-34 weeks) delivered between 1998 and 2003 at UAMS. The cesarean section rate was 63.