Pyridinium-Derived Mesoionic N-Heterocyclic Olefins (py-mNHOs).

Mesoionic polarization allows access to electron-rich olefins that have found application as organocatalysts, ligands, or nucleophiles. Herein, we report the synthesis and characterization of a series of 3-methylpyridinium-derived mesoionic olefins (py-mNHOs). We used a DFT-supported design concept, which showed that the introduction of aryl groups in the 1-, 2-, 4-, and 6-positions of the heterocyclic core allowed the kinetic stabilization of the novel mesoionic compounds.

Translation of the copper/bipyridine-promoted Petasis reaction to solid phase-coupled DNA for encoded library synthesis.

The Petasis three-component reaction gives rise to diverse substituted α-aryl glycines from readily available amines, boronic acids and glyoxalic acid. Thus, this reaction is highly attractive for DNA-encoded small molecule screening library synthesis. The Petasis reaction is for instance promoted by a potentially DNA damaging copper(I)/bipyridine reagent system in dry organic solvents.

Polychromatic percepts during hypergravity.

Future helmet mounted systems and cockpit displays will rely on color graphics and information that high performance aircraft pilots will need to discern and understand. Color in displays may help reduce pilot workload. The effect of high G and reduced eye level blood pressure on field-of-view has been study extensively.

Female exposure to high G: performance of simulated flight after 24 hours of sleep deprivation.

Background: Ground-based research has investigated the loss of cognitive function in the extreme conditions of G-induced loss of consciousness, however, little is known about pilots' abilities to maintain cognitive performance throughout prolonged conscious exposure in the high-G environment. The effects of fatigue and G layoff on performance during exposure to high G are mostly unknown for the female population.

Methods: This research was conducted on the centrifuge Dynamic Environment Simulator.

Evaluation of integrated night vision goggle (NVG) helmets under sustained +Gz.

Three integrated night vision goggle (NVG) helmets from different manufacturers were evaluated under high-G conditions. Structural and operational integrity, as well as neck forces in pounds, were determined via instrumented manikin testing before human exposure with the helmets during sustained +Gz. Results of the manikin testing showed that the helmets could withstand the rigors of high-G, and that predicted forces (using helmet weights and centers-of-gravity) matched those obtained experimentally from load cells in the x-axis of the manikin's neck.