Making Discoveries that Make a Difference

Analytical

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Dr. Abul Hussam: “I have been involved in the development electroanalytical techniques for the study of toxic species in the environment. We are particularly interested in the chemistry of arsenic in groundwater and the development of inexpensive arsenic filters.

First, we have developed a field technique to measure parts-per-billion level of arsenic species in groundwater. Second, we have devised a simple method to purify groundwater from toxic arsenic species. More than 10,000 such filters are in use in Bangladesh and continue to provide more than a Billion liter of clean drinking water.

In addition, we are actively engaged in the development of hardware and virtual software for electroanalytical engines (reagent generator and sensor) to be used with ‘lab-on-chip’ platform. We have also extended the use of electrochemical techniques to understand the diffusion behavior and electron transfer kinetics of lipophilic redox species in organized media such as micelles and microemulsions.

To complement these studies we have built a high precision headspace gas chromatograph to study the partition behavior of volatile species in complex micelles and microemulsions.”

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Dr. John Schreifels: “My laboratory works on problems associated with the solid – gas interface. We study molecular events occurring in the top few atom layers of solid surfaces (thickness levels of about 1/10000 the thickness of a human hair).

Recently, we studied the interaction of fuel additives with stainless steel surfaces. Certain compounds (called metal deactivators, MDA) are added to bulk fuel to eliminate fuel degradation during long term storage under ambient conditions. It turns out that fuels also form dark thick deposits on injectors of jet engines during operation. The temperature in the injector is much higher, which means the deposition rate is much higher than in the bulk fuel. These deposits can cause catastrophic failure of the engine.

The presence of MDA can reduce this effect. We studied the fundamental interactions of the compound with stainless steel in our instrument under ultra – high –vacuum conditions. The vacuum insured that we were studying only the interaction of the compound with the stainless steel surface. We found that the compound broke into smaller fragments upon initial exposure of the surface to the compound.

There were several new compounds generated in addition to the original compound that might have been the cause of the reduced deposition of residues on the surface. In fact because of the temperature at which each of these compounds desorb, from the surface we believe the new compounds may very well be responsible for the reduced rate of deposition.

Using the insights from this study, we will continue to deposit other compounds with chemical structures similar to the compounds detected on the surface to try to understand how to produce an improved effect. Additionally, we are studying the adsorption of compounds that are used to reduce the extent of corrosion.

Finally, our studies have involved metallic surfaces and how they interact with compounds to produce new compounds; these metal surfaces are often called catalysts and are used extensively in the chemical industry.”

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Biochemistry

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Dr. Barney Bishop: “In my laboratory, we are interested in applying peptide/protein engineering principles to investigate biomolecules and their function. The rampant increase in the incidence of multi-drug resistant bacteria and the threat of bioterrorism necessitate new approaches to preventing and treating infection.

Higher organisms produce a complex host of molecules that they use to combat infection and invading microbes. In these defensive mechanisms, peptides and proteins consistently stand out as critical elements. Therefore, we are interested in studying the biophysical properties of these molecules and the varied antimicrobial mechanisms employed by them.

As a model system, we are looking at the defensin family of peptides, whose members demonstrate antimicrobial activity against a broad spectrum of pathogens including bacteria, fungi and viruses. We believe that such studies will provide valuable insights into strategies for combating bacterial and viral infections, and we intend use this information in the design of novel therapeutic agents and biomaterials.”

Bishop Group Website

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Dr. Robin Couch
The Couch lab is researching several aspects of developments of MEP pathway inhibitor antibiotics, small molecule metabolomics, biosensor/electronic nose, and chemoprevention of Alzheimer’s disease.

The increasing prevalence of antibiotic resistant strains emphasizes the need for continued development of new antibiotics with novel mechanism of action. Many human pathogens exclusively use the methylerythritol phosphate (MEP) pathway, making it an excellent target. To facilitate MEP pathway inhibitor development, my lab has cloned, expressed, and enzymatically characterized several MEP pathway enzymes. We are iteratively deriving structure-activity relationships and performing mechanism of inhibition assays to guide the development of rationally designed synthetic inhibitors of these enzymes.

We are also using state-of-the-art metabolomics techniques to evaluate small molecule metabolites present in biological samples, including feces. We are currently using both GC-MS and LC-MS in our analyses to examine fecal volatile organic compounds (VOCs). We discovered that the current technologies were inadequate to facilitate a proper headspace solid phase microextraction-based (hSPME) metabolomics analysis of biological samples. We developed and patented a device that enables these analyses, and coined the term “simulti-hSPME” to describe our optimal process of using multiple sorbent types to simultaneously extract VOCs of diverse chemistries from a sample. We are also using our newly developed simulti-hSPME for the rapid and minimally invasive detection of biothreat-relevant microbes (“electronic nose”).

We are applying our small molecule and protein expertise to determine the signal transduction mechanism underlying the ability of select small molecules to induce nerve growth factor release from glial cells. Nerve growth factor keeps neurons alive, and thus has promise for the chemoprevention of Alzheimer’s Disease. Using cultured human glial cells, we have utilized reverse phase protein microarrays to generate temporal maps of signal transduction protein activation, and we are now validating the involvement of these proteins/pathways using pathway specific agonists and antagonists.

Couch Group Website

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Dr. Lee Solomon
Dr. Solomon will join us in June 2019 as an Assistant Professor of Biochemistry. His research lab will be on the Science & Tech campus (Manassas, VA). His work centers on using rational-design methodologies to understand natural functions and create proteins and materials, which will allow for the creation of new medicines and energy technologies. Dr. Solomon’s research lab will focus on three primary areas: (1) stimulated structural and morphological changes, (2) protein interactions, and (3) catalytic chemistry.

Bio

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Environmental

Dr. Gregory Foster: “Students in the Foster research laboratory investigate the sources, reactions and transport of contaminants in the aquatic environment. Currently, we have two ongoing lines of active research. The first involves determining the amounts and sources of polychlorinated biphenyls (PCBs) in storm runoff in the Anacostia River, a tributary of the Potomac River that runs through Washington, DC.

PCBs are persistent, carcinogenic organochlorine contaminants that are thought to adversely affect both human and environmental health. The Anacostia River is one of the three most heavily contaminated PCB regions in the Chesapeake Bay watershed, where the highest sedimentary PCB concentrations have been reported to date. We are aiding in a massive clean up of PCBs in the Anacostia River. Storm flow runoff is the primary mode of input of PCBs in the Anacostia River, and storm flow inputs must be characterized to design effective, long-term clean up strategies.

The second line of research is in determining the inputs of pharmaceutical and personal care chemicals in the Potomac River. Over 32 wastewater treatments plants in the metropolitan DC region release pharmaceutical chemicals through wastewater discharge, and some of these biologically active chemicals are severely impairing reproductive development in fish species by serving as estrogen mimics (as recently reported in the Washington Post). We are investigating the nature of pharmaceutical chemical inputs and potential estrogenic effects in aquatic organisms.”

Foster Group Website

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Dr. Benoit Van Aken: “The mission of the Van Aken’s Environmental Molecular Biology Lab is to develop and apply molecular biology tools to solve environmental issues.

Dr. Van Aken’s primary research interests have focused on the development of molecular biology methods for various environmental applications, including bioremediation, biofuel production, and water quality surveillance. He is currently conducting research in two major areas: (1) the molecular response of organisms exposed to environmental stressors (toxicogenomics) and (2) the development of molecular biomarkers for the detection of harmful aquatic organisms, including pathogens, invasive species, and toxic algae. Dr. Van Aken has been PI or co-PI on multiple research projects funded by state and federal agencies, including NASA, NIH, NSF, PennDOT, SERDP, and USDA.”

Van Aken Group Website

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Inorganic

Dr. Xiaoyan Tan: “Our group focuses on the discovery of functional and multifunctional inorganic solid-state materials, ranging from intermetallics to oxides, with applications in technology and energy conversion. We specifically target materials with noncentrosymmetric and polar space groups, which include (but not limited to) metallic oxides, oxide thermoelectric materials, multiferroics, and magnetic semiconductors.

Students will be trained on the synthesis of crystalline inorganic solid-state materials by various methods, growth of single crystals, structural analysis, calculations of the electronic structure, and characterization of the physical properties of inorganic solid-state materials. Students will also have the opportunity to learn X-ray neutron diffraction while using state-of-the-art research facilities at national laboratories such as Argonne National Laboratory (ANL), Brookhaven National Laboratory (BNL), National Institute of Standards and Technology (NIST), and Oak Ridge National laboratory (ORNL).”

Tan Group Website

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Organic

 

Mikell Paige, PhD

Education
PhD, Chemistry, University of Virginia
Key Interests
Drug Discovery | Pulmonary Inflammation | Fibrosis | Traumatic Brain Injury | Medicinal Chemistry | Organic Synthesis | Enzymology | Protein Chemistry
Contact

Phone: 703-993-1075 | Email: mpaige3@gmu.edu

Research Focus

The focus of our lab is drug discovery. We utilize medicinal chemistry strategies for the design and synthesis of small molecule modulators of dysfunctional enzymes. We utilize structural biology and computational chemistry in conjunction with kinetic assays to determine enzyme mechanisms. Our capabilities also include the design, synthesis, and characterization of peptidomimetic inhibitors of protein-protein interactions.

Targets we are currently pursuing in our lab are mainly focused on diseases of the lung to include chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). We are also developing projects targeting viral infections, gram-negative bacterial infections, and traumatic brain injury (TBI).

Current Projects

■ Design and synthesis of small molecule modulators of the leukotriene A4 hydrolase enzyme for pulmonary inflammation

■ Inhibiting protein-protein interactions with modified natural product macrocycles as a strategy for targeting idiopathic pulmonary fibrosis

■ Determining the kinetic mechanisms for small molecule activators of enzymes

■ Iterative approaches to the synthesis of new peptidomimetic scaffolds

Select Publications

■ M. Paige et al., Role of leukotriene A4 hydrolase aminopeptidase in the pathogenesis of emphysema. J Immunol. 192, 5059-5068 (2014).

■ H.R. Fernandez et al., The mitochondrial citrate carrier, SLC25A1, drives stemness and therapy resistance in non-small cell lung cancer. Cell Death Diff. 25, 1239-1258 (2018).

■ N. Farhan et al., Ultrapressure liquid chromatography- tandem mass spectrometry assay using atmospheric pressure photoionization (UPLC-APPI-MS/MS) for quantification of 4-methoxydiphenylmethane in pharmacokinetic evaluation. J Pharm Biomed Anal. 128, 46-52 (2016).

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Dr. Chao Luo: “Dr. Luo will join us in June 2019 as an Assistant Professor of Organic Chemistry.  His research lab will be on the Fairfax campus. His current work focuses on (1) structure design and material fabrication for organic alkali-ion batteries, (2) high-energy lithium sulfur batteries, and (3) all-solid-state lithium batteries.

Dr. Luo’s research lab will explore the use of organic/inorganic materials and new fabrication techniques to design and synthesize novel organic electrodes, porous carbon, nanostructures and their hybrid composites to address environment and energy challenges.  A fundamental understanding of reaction mechanism and kinetics, investigation of structure-property correlations and development of functional structures and devices will be explored.”

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Physical

Dr. Hao Jing: “We are deeply fascinated by the bilateral interaction between light and matter and interested in the way that matter can profoundly change light. The light can be squeezed into dimensions much smaller than its wavelength and manipulated in a smart way by interacting with nanoscale materials. Research areas will be briefly centered on design and fabrication of inorganic nanomaterials based on the noble metal nanostructures (Au and Ag) with geometrically tunable optical properties and lanthanide-doped upconversion nanocrystals (UCNPs) and the applications in catalysis and sensing. The main theme of the research is to use synthetic and physical chemistry methods to gain better understanding on both chemical and physical properties in nanoscience.

Our current research is primarily centered on the design and development of novel plasmonic and rare-earth upconversion nanomaterials taking advantage of physical chemistry approaches for a broad range of applications, including but not limited to catalysis, nanomedicine and sensing with the ultimate goal of gaining deep scientific insights to structure-property relationship.

We welcome highly motivated young scientists to join our group to create new wonders in chemistry world with passion and enthusiasms!”

Jing Group Website

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