Water moves through multifaceted physical boundaries. This poses a significant challenge for scientists who must simulate water flow across many domains. Scientists at Pacific Northwest National Laboratory conquered this barrier by merging different physical laws. Their new approach can describe any type of water flow in soils and the terrestrial ecosystem, in soil pores, streams, lakes, rivers and oceans, and in mixed media of pores and solids for soil and aquifer. The versatile properties of the new approach allow cross-domain simulation of water flow at different scales. The research was published in the Soil Science Society of America Journal.
A team of scientists from Pacific Northwest National Laboratory synthesized a chemical activity-based probe (ABP) that can provide new information about how living cells function. The new ABP is designed to enter a living cell without interacting with anything until it enters a specific organelle: the lysosome. This proof-of-concept ABP then labels only functionally active enzymes called cathepsins, which are cysteine proteases, in the lysosome. Using proteomics and super-resolution microscopy to view these labeled enzymes, the scientists now are able to see organellar activity. Their work, which demonstrates the ability to manipulate chemistry to better understand biology, has been published in Angewandte Chemie International Edition.
Congratulations to PNNL scientists Susan Crowell and Justin Teeguarden for their contributions to two published papers named "Best Papers Published in 2013 Demonstrating Application of Risk Assessment" by the Risk Assessment Specialty Section of the Society of Toxicology. Crowell and Teeguarden were the primary authors of their respective papers. Rick Corley and Chuck Timchalk were senior authors. Crowell's paper "Impact of Pregnancy on the Pharmacokinetics of Dibenzo[def,p]chrysene in Mice" appeared in Toxicological Sciences. Teeguarden's "A Multi-route Model of Nicotine-cotinine Pharmacokinetics and Brain Nicotinic Acetylcholine Receptor Binding in Humans," appeared in Regulatory Toxicology and Pharmacology.
A multidisciplinary team at Pacific Northwest National Laboratory is the first to demonstrate imaging of a biofilm's chemical components as they form in hydrated biological samples, rather than from frozen or dried samples. They used a surface technique called time-of-flight secondary ion mass spectrometry to study complex microbiological processes, such as chemical attachment of microbes to surfaces to form biofilms. The work used PNNL's vacuum-compatible liquid probe.
PNNL scientist Justin Teeguarden and former PNNL scientist Harish Shankaran received the Best Abstract Award for 2014 from the Risk Assessment Specialty Section of the Society of Toxicology. Teeguarden will present "Improving Urine-Based Human Exposure Assessment of Short-Lived Chemicals Using Reverse Dosimetry and NHANES Physiological and Behavior Data: A Value-of-Information Approach for Bisphenol A" at the Society's annual meeting in March.
Teeguarden leads research related to chemical risk assessment and health effects, most notably that related to the use of Bisphenol A in plastics, and has served on national advisory panels for the National Research Council and the National Academy of Sciences.