Physical sciences

Armin's research focuses on the effect of aerosol particles on the environment, clouds and rainfall, climate, and public health/welfare. A suite of synergistic methods are used for this research, including laboratory experiments, ground and airborne field measurements, modeling, and remote sensing observations. Since 2004, he has participated in 15 airborne field projects, including six as a mission PI with the CIRPAS Twin Otter (sponsored by ONR). Currently, Armin is involved with a multi-year NASA project called CAMP2EX (Cloud and Aerosol Monsoonal Processes-Philippines Experiment; https://espo.nasa.gov/camp2ex/content/CAMP2Ex) and is serving as the PI of a NASA Earth Venture Suborbital-3 (EVS-3) mission called ACTIVATE (Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment; https://activate.larc.nasa.gov/).

I am interested in exploring innovative and useful chemical tools and small molecules as probes to study biology and as therapeutics for disease treatment. My laboratory has been particularly interested in exploring chemical tools to address the important biological questions. I am a well-established investigator with over 20 years research experience and more than 240 peer reviewed publications (H-index: 72) in the fields of organic and medicinal chemistry and chemical biology. The small molecule-based fluorescence probes developed from my laboratory have been widely used by biomedical researchers as tools to study the cellular and molecular mechanisms. One of the small molecules discovered by my laboratory has been licensed to the Andaman Therapeutics for clinical trials as a new class of anticancer therapy.

Stephen Wright, PhD, is focused on understanding the molecular and cellular physiology of organic electrolyte transport in the kidney. The kidney, particularly the proximal tubule, actively secretes a wide array of organic ions, largely derived from dietary or pharmaceutical sources. Many of these compounds are toxic and renal secretion of these xenobiotic compounds plays a critical role in protecting the body from these agents. However, this task also places the kidney in harm's way, and the development of nephrotoxicity is one consequence of the renal secretion of what are typically referred to as organic anions and organic cations. Dr. Wright’s lab currently studies the renal transport of organic anions and cations at several different levels of biological organization.At the molecular level, they clone individual transport proteins for use in studies that gauge the effect of protein and substrate structure on the transport process. At the cellular level, Dr. Wright and his lab use cultured cells (including primary renal cells, continuous renal cell lines, and generic cells lines for the expression of cloned transport proteins) in studies of the activity and regulation of transport activity. At the tissue level, they use isolated, intact renal proximal tubules, including single non-perfused and perfused tubules, to study the process of organic electrolyte secretion as it occurs in the native renal epithelium.Studies employ a wide array of methodologies, including molecular cloning, site-directed mutagenesis, construction of fusion proteins, kinetic assessment of membrane transport in cultured cells, suspensions of isolated renal tubules and in single tubule segments using radiometric and real-time optical approaches, computationally-based assessment of transporter, and substrate structure and 3D distribution of cell type distribution along the renal nephron. Keywords: Membrane Transport; Kidney; Drug Clearance

Joseph C. Watkins is Professor of Mathematics and Chair of the Graduate Interdisciplinary Program in Statistics at the University of Arizona. Dr. Watkins has published works in the foundations of the theory of probability and has collaborated extensively with researchers in a variety of the life sciences, notably, genetics, biophysics, anthropology, bacteriology, entomology, and biochemistry. He was recognized in 2009 by the College of Science for his contributions in being named a Galileo Circle Fellow. Dr. Watkins work includes both new results in stochastic modeling and in both the theoretical and practical aspects of statistics. His research interests are broad, from understanding the mechanism of the Africanization of the honeybee to the dynamics of single molecule motors to the ancient structure of human populations in Africa. Dr. Watkins has been a leader at the University of Arizona in the interdisciplinary training at the biology/math interface both at the undergraduate and graduate level. He has been a co-investigator for an IGERT training grant and is a member of the steering committee for an NIH training grant housed in an Applied Mathematics Program. In addition, Dr. Watkins serves as the chair of the Undergraduate Biology Research Program’s Biomath Committee.

My research interests relate to the theoretical chemistry and biophysics of complex systems. Current areas of funded research include the study of protein dynamics in enzymatic reactions, quantum tunneling in enzymatic reactions, modeling of the cardiac thin filament with application to disease mechanism, and the study of the properties of micelles created from green surfactants. I am chair elect of the biological physics division of the American Physical Society, a Fellow of the APS and the AAAS.

Our research program is focused on the synthesis and characterization of novel polymeric and composite materials, with an emphasis on the control of nanoscale structure. Recent developments in polymer and colloid chemistry offer the synthetic chemist a wide range of tools to prepare well-defined, highly functional building blocks. We seek to synthesize complex materials from a "bottom up" approach via the organization of molecules, polymers and nanoparticles into ordered assemblies. Control of structure on the molecular, nano- and macroscopic regimes offers the possibility of designing specific properties into materials that are otherwise inaccessible. We are particularly interested in compatabilizing interfaces between organic and inorganic matter as a route to combine the advantageous properties of both components. This research is highly interdisciplinary bridging the areas of physics, engineering and materials science with creative synthetic chemistry.

Dr. Polt began his research career by developing methods for amino acid synthesis in Prof. Marty O’Donnell’s lab at IUPUI. After that he was trained in the art of Organic Synthesis in the laboratories of Profs. Gilbert J. Stork at Columbia University and Dieter Seebach at the ETH in Zürich. He has continued to develop novel synthetic methods for amino acids, amino alcohols, glycosides and glycopeptides. Application of these methods resulted in the production of a number of pharmacologically active glycopeptides (GPCR agonists), alkaloid-like inhibitors of glycolipid processing enzymes and glycosyltransferases, as well as glycolipids with biological activity such as glycosphingolipids and rhamnolipids. The biological focus of his work has been in attempting to understand the chemistry of carbohydrates (e.g. glycolipids, glycoproteins) at cell membranes, membrane trafficking, and using these insights to design glycopeptide drugs from endogenous peptide neurotransmitters (neuromodulators, hormones) with enhanced stability in vivo that are capable of penetrating the Blood-Brain Barrier and interacting with GPCRs as agonists or antagonists. Presently, Polt studies the design, synthesis and testing of agonists related to the hormones Oxytocin and PACAP (Pituitary Adenyl Cyclase Activating Peptide), as well as other glycopeptide drug candidates.

Clinical applications of the glycopeptide drugs include pain, opioid use disorder, migraine, Parkinsons, Alzheimers and other neurogenerative diseases. In addition to lecturing and laboratory teaching during 35 years at the University of Arizona, and the publication of more than 137 scientific papers, he has mentored a large number of undergraduate, graduate (21 Ph.D.s granted, 2 in progress) and post-doctoral students who have taken positions in academia, industry and the US government. His Ph.D.s have hailed from the US (10), Czech Republic*, China, Germany*, India, Iran*, Ireland, Jordan*, Kenya*, Korea, Mexico* and Sri Lanka. Six of these Ph.D. graduates (*) have gone on to become naturalized citizens or obtain permanent resident status. Recent undergraduates associated with his research group have gone to graduate schools at Harvard, MIT, Boston University, University of Wisconsin, and Columbia University.

Jeanne Pemberton, PhD, is a household name in chemistry departments across the country. Her research on surface vibrational spectroscopy has enabled fundamental advances in the field of analytical chemistry.In her 25 years at The University of Arizona, Pemberton has received more than 40 research grants. Among the many boards and committees she serves, she was the chair of the Math and Physical Sciences Advisory Committee at the National Science Foundation in 2004. In addition to receiving the College of Science Distinguished Teaching Award, she has also received the distinguished American Chemical Society Award for Excellence in Analytical Chemistry, which is among the highest honors in her field.Dr. Pemberton’s group research seeks to develop an understanding of chemistry in several technologically important areas including electrochemistry and electrochemically-related devices, chromatography, self-assembled monolayers, surfactant systems, and environmental and atmospheric systems. Methodologies employed for these efforts include surface vibrational spectroscopies, near-field optical methods, electrochemistry, x-ray photoelectron spectroscopy, Auger electron spectroscopy, LEED, work function measurements, ellipsometry, electron microscopy, and the scanning probe microscopies AFM and STM. Molecular nanoscale imaging exists prominently in the ability to elucidate structural and mechanistic details of surface and interfacial chemistry.Two images of transient intermediate states on NaCl in its reaction with the mineral acids, HNO3 and H2SO4, are shown below. These transient structures are formed en route to the final surface products of crystalline NaNO3 and NaHSO4, respectively.Specific interfacial systems of interest include electrochemical battery and electroluminescent and electrochromic devices, models of these devices fabricated and studied in ultrahigh vacuum, organized molecular assemblies at solid surfaces or air-water interfaces formed spontaneously or by self-assembly or Langmuir-Blodgett techniques, chromatography stationary phase systems, soil and mineral systems important in the fate and transport of environmentally important chemicals, and surfaces such as ice, mineral acids, and alkali halides important in atmospheric processes.

Dominic Mcgrath, PhD, set forth a program which involves the use of organic synthesis for the design, development, and application of new concepts in macromolecular, supramolecular, and materials chemistry. Research efforts span a number of areas in the chemical sciences and include studies of: 1) chiral dendritic macromolecules and the effect of chiral subunits on dendrimer conformation, 2) photochromic dendrimers and linear polymers which undergo structural changes in response to visible light, 3) liquid crystalline materials based on dendritic and photochromic mesogens, and 4) synthesis of new ligands based on saturated nitrogen heterocycles.A continuing interest remains in the effect of structural perturbations on the properties and functional of dendritic macromolecules. Part of this research addresses the design, synthesis, and study of dendrimeric materials containing chiral moieties in the interior for influencing the conformational order of these 3-dimensional macromolecules. An ultimate goal is to develop materials active for the selective clathration of small guest molecules. Potential applications include chemical separations, sensor technology, environmental remediation, and asymmetric catalysis.Dr. Mcgrath and his lab team recently developed several new classes of dendritic materials containing photochromic subunits. As nature uses light energy to alter function in photoresponsive systems such as photosynthesis, vision, phototropism, and phototaxis, they use light energy to drive gross topological or constitutional changes in fundamentally new dendritic architectures with precisely placed photoresponsive subunits. In short, they can drive dendrimer properties with light stimuli. Two entirely new classes of photoresponsive dendritic macromolecules have been developed and include: 1) photochromic dendrimers and 2) photolabile dendrimers. Dr. Mcgrath anticipates that switchable and degradable dendrimers of this type will have application in small molecule transport systems based on their ability to reversibly encapsulate guest molecules. He continues to develop these materials as potential transport hosts and photoresponsive supramolecular assemblies.

My research interests are in the field of theoretical image science with emphasis on medical imaging. I currently study task-based measures of image quality in which one must define the task the images are to be used for and the observer who will be performing this task, to properly measure and optimize the quality of images and imaging systems. We take the stance that imaging systems should be designed to best enable the observer to detect tumors and not base design decisions on resolution, contrast, etc. Topics in my research group include accurate system modeling, statistical modeling, observer performance metrics, signal-detection theory and general image science.