Dr. Jessica Burger is an NRC postdoctoral fellow working in the Applied Chemicals and Materials Division at NIST, Boulder. She is focused on studying the volatility of diesel fuel mixtures by distillation and studying the rheological properties of high concentration DNA solutions. She earned her PhD at the University of Colorado in 2009, having developed a micronized pharmaceutical formulation that would stabilize a live attenuated measles vaccine, and produce powders with properties appropriate for deep lung delivery. At NIST Dr. Burger is characterizing diesel fuels with oxygenating additives to control particulate emissions. She also works with compact sized viscometers and rheometers to examine the viscoelastic properties of high concentration DNA solutions to better understand the rheological properties of CF sputum, in order to develop diagnostic tools and screen possible therapeutic agents. The absence of rapid clinic-ready rheological measurement technologies constitutes a significant obstacle to achieving more personalized treatment regimes for CF and other pulmonary diseases. Fast and accurate rheological measurement techniques are needed to understand the complex biological pathways, monitor disease progression, and evaluate the effectiveness of therapeutic treatments. In her spare time Jessica enjoys riding her horse and knitting.
Alternative Fuel Characterization:
The distillation curve of fuel mixtures can be used to assess the degree of departure from the base fuel. This is of importance when formulating fuels with low particulate emissions. In particular, it is critical to characterize the mixture properties of diesel fuel with oxygenate additives as volatile additives cause significant departures from the distillation curves of diesel fuel. We also note that the additive affects the curve shape and temperature profile even after being totally depleted, an observation made in earlier studies of oxygenate additive mixtures.
Viscoelastic Properties of High Concentration DNA Solutions:
Cystic Fibrosis (CF) airway surface liquids contain high concentrations of extracellular DNA. The resulting sputum exhibits changes in elasticity, adhesivity, and rheological properties, which impair cough clearance and mucosillary transport. As a model for sputum, the viscosity of DNA solutions, and its susceptibility to condensing agents, is being examined. Because the temperature dependence of viscosity is as important as the viscosity itself, the viscosity of the DNA solutions is measured at various temperatures. Initial measurements revealed concentration dependent viscosity maxima in the range from 50 ˚C to 65 ˚C. The compact viscometer that is mainly used in this work offers high throughput for screening of potential therapeutic agents.