Graduate Seminars
2015
Professor David Sholl
Georgia Tech
"Using High Throughput Computation to Accelerate
Development of Materials for Scalable Energy Technologies"
Abstract
Computational modeling of materials can be a powerful complement to experimental methods when models with useful levels of predictive ability can be deployed more rapidly than experiments. Achieving this goal involves judicious choices about the level of modeling that is used and the key physical properties of the materials of interest that control performance in practical applications. I will discuss two examples of using high throughput computations to identify new materials for scalable energy applications: the use of metalorganic frameworks in membranes and gas storage and the selection of metal hydrides for high temperature nuclear applications. These examples highlight the challenges of generating sufficiently comprehensive material libraries and the potential advantages and difficulties of using computational methods to examine large libraries of materials.
Wednesday, October 14, 2015
12:30 pm, HED 116
2014
Professor Amy Karlsson
Department of Chemical and Biomolecular Engineering
University of Maryland
“Engineering Peptides and Proteins to Combat Human Disease”
Abstract
Rational design and directed evolution are both powerful approaches for engineering proteins and peptides. Our lab applies these approaches to exploit the power of proteins and peptides in studying and combatting human disease, and I will discuss applications of protein engineering in fungal disease and cancer. We applied a rational design approach to engineer non-natural antimicrobial β-peptides that exhibit antifungal activity against the fungal pathogen Candida albicans. Through this work, we developed a deeper understanding of the properties of β-peptides that contribute to their toxicity towards fungal cells and fungal biofilms, and we are currently working on ways to apply this understanding to designing improved antifungal agents. We have also used directed evolution to engineer antibodies that can fold and function inside cells, which has broad applications in human diseases, including cancer. The reducing environment inside cells prevents formation of the disulfide bonds normally required for proper antibody folding, but we have developed a bacterial inner membrane display system that harnesses the cytoplasmic folding quality control mechanisms of the Escherichia coli twin-arginine translocation pathway to engineer proteins able to fold in the cytoplasmic environment. We used this method to display and screen a combinatorial library of single-chain variable fragment (scFv) antibodies and isolated scFvs with dramatic improvements in both antigen-binding and intracellular solubility. We are now using our display method to engineer scFvs for studying and treating cancer and fungal disease.
Bio
Dr. Amy J. Karlsson received her bachelor’s degree in chemical engineering from Iowa State University in 2003 and then joined Prof. Sean Palecek’s group at the University of Wisconsin, where she received her PhD in chemical engineering in 2009. Following her doctoral work, she was an NIH Ruth L. Kirschstein Postdoctoral Fellow in Prof. Matt DeLisa’s lab at Cornell University. Dr. Karlsson joined the Department of Chemical and Biomolecular Engineering at the University of Maryland as an assistant professor in 2012. Her group’s research lies at the interface of biology and engineering and uses protein engineering strategies to improve the understanding of human diseases and develop tools for drug design and disease diagnosis.
Thursday, May 1, 2014
12:45 pm, ZHS 159
The scientific community is cordially invited.
2011
Dr. Yvonne Chen
California Institute of Technology
Pasadena, CA
“Genetic Control of T-Cell Proliferation with Synthetic RNA Regulatory Systems”
Abstract
Adoptive T-cell therapy seeks to harness the precision and efficacy of the immune system against diseases that escape the body’s natural surveillance. Clinical trials have demonstrated the use of cytolytic T cells (CTLs) genetically engineered to express disease-specific antigen receptors as a promising treatment option for opportunistic diseases, virus-associated malignancies, and cancers. However, the safety and efficacy of T-cell therapies depend, in part, on the ability to regulate the fate and function of CTLs with stringency and flexibility. The emerging field of synthetic biology provides powerful conceptual and technological tools for the construction of regulatory systems that can interface with and reprogram complex biological processes such as cell growth. Here, we present the development of synthetic RNA-based regulatory systems and their applications in advancing cellular therapies. Rationally designed, drug-responsive ribozyme switches are linked to the proliferative cytokines IL-2 and IL-15 to construct cis-acting regulatory systems capable of T-cell proliferation control in both mouse and primary human T cells. We further demonstrate the ability of our synthetic controllers to effectively modulate T-cell growth rates in response to drug input in animal models. In addition, we report the development of rationally designed, miRNA-based regulatory devices capable of drug-responsive control over the expression of endogenous cytokine receptor chains. The RNA-based regulatory systems exhibit unique properties critical for translation to therapeutic applications, including adaptability to diverse ligand inputs and regulatory targets, tunable regulatory stringency, and rapid response to input availability. By providing tight gene expression control with customizable ligand inputs, RNA-based regulatory systems can greatly improve cellular therapies and advance broad applications in health and medicine.
Friday, April 22, 2011
3:30 pm, HED 116
The scientific community is cordially invited.
2011
Dr. Hong Shen
Department of Chemical Engineering
University of Washington
“Biomaterial-engineering the Immune System”
Abstract
Our research interfaces biomaterials, the immune system and engineering design. We use materials with defined properties to probe how the immune system interacts with biomaterials at both cellular and molecular levels. Built upon our understanding, we design biomaterials to exploit intracellular pathways of immune cells for safe and effective therapeutics, such as tissue implants, non-viral gene delivery systems and vaccines. These biomaterials also provide an excellent tool for us to further dissect the cellular and molecular mechanisms by which immune responses are triggered and sustained. A challenge of current vaccines is to achieve a spectrum of immune responses in a single construct. In this talk, I will mainly discuss how we bring together the aforementioned research interests to address this challenge.
Monday, February 28, 2011
12:45 pm, HED 116
The scientific community is cordially invited.
2011
Dr. Andrew Peterson
Stanford University
Stanford, CA
“Catalysis Design for Sustainable Fuels”
Abstract
Quantum mechanics-based tools have advanced to the point where the computational design of catalysts from first principles is becoming possible. In concert with experiments, these tools can be used for improving catalytic processes for sustainable fuel synthesis. First, I will describe how we are employing density functional theory (DFT) to understand the (photo-)electrocatalytic activity of materials to reduce CO2 to hydrocarbons (solar fuels). We have identified the elementary mechanisms that make this transformation possible and have shown that the protonation of adsorbed CO dictates the overall efficiency of the transformation. By using computational screening tools, we are discovering new candidate materials that can reduce the overpotential of this step, which may help to make solar fuels technologically and economically feasible. In the second part of the talk, I will show how creative catalyst design can enable the development of an efficient and adaptable biorefinery that produces the light end (C0-C3) product spectrum of a conventional refinery. The design of catalysts that can perform decarboxylation reactions without being subject to CO fouling will be key in this development, as will the design of catalysts for the selective synthesis of gasoline-range hydrocarbons from light-end feedstocks. These advances can lead to flexible biorefineries that are adaptable to changing market dynamics.
Thursday, February 17, 2011
11:00 am, ZHS 159
The scientific community is cordially invited.
2010
Dr. Lofti Zadeh
Professor and Director of the Berkeley Initiative in Soft Computing (BISC)
“Computing with Words”
Abstract
Bio
Lofti A. Zadeh is an alumnus of the University of Tehran, MIT and Columbia University. His earlier work was concerned in the main with systems analysis, decision analysis and information systems. His current research is focused on fuzzy logic, computing with words and soft computing, which is a coalition of fuzzy logic, neurocomputing, evolutionary computing, probabilistic computing and parts of machine learning. Lotfi Zadeh is a Fellow of the IEEE, AAAS, ACM, AAAI, and IFSA. He is a member of the National Academy of Engineering and a Foreign Member of the Finnish Academy of Sciences, the Polish Academy of Sciences, Korean Academy of Science & Technology, the Bulgarian Academy of Sciences, the International Academy of Systems Studies, Moscow and the Azerbaijan National Academy of Sciences. He is a recipient of many medals and awards as well as twenty –five honorary doctorates. He has published extensively on a wide variety of subjects relating to the conception, design and analysis of information/intelligent systems, and is serving on the editorial boards of over seventy journals.
Friday, October 22, 2010
3:00 pm, MHP Auditorium
The scientific community is cordially invited.
2010
Dr. Jongseung Yoon
Beckman Institute for Advanced Science and Technology
UIUC
“Printed Assembly of Micro/Nanomaterials with Silicon and Gallium Arsenide Based Compound Semiconductors for High Performance Photovoltaics and Optoelectronics”
Abstract
In the first part of my talk, I will present our recent work that explores techniques to exploit silicon for unusual photovoltaic module designs. Silicon, in amorphous or various crystalline forms, is used in >90% of all installed photovoltaic (PV) capacity. The high natural abundance of silicon, with the excellent reliability and good efficiency of solar cells made with it, suggest its continued use, on massive scales, for the foreseeable future. As a result, although there is significant promise for organics, nanocrystals, nanowires and other new materials for photovoltaics, many opportunities continue to exist for research into unconventional means for using silicon in advanced PV systems. We developed new approaches to exploit printed arrays of ultrathin, monocrystalline Si solar microcells for unconventional photovoltaic modules. The resulting devices can offer many useful features, including high degrees of mechanical flexibility, user-definable levels of transparency, ultra-thin form factor micro-optic concentrator designs, together with the potential for high efficiency and low cost.
In the second part of my presentation, I will discuss about releasable epitaxial multilayer assemblies of gallium arsenide (GaAs) based compound semiconductors for high performance photovoltaics and optoelectronics. Compound semiconductors such as GaAs provide unmatched performance in photovoltaic and optoelectronic devices. Current methods for growing and fabricating these materials are incompatible with the most important modes of use, particularly in photovoltaics, where large quantities of material must be distributed over large areas on low cost, amorphous foreign substrates. We developed new methods that address many of these challenges, through cost effective production of bulk quantities of high quality functional films of GaAs from thick, epitaxial assemblies formed in a single deposition sequence on a growth wafer. Specialized designs enabled separation, release and assembly of individual active layers in these stacks to create devices on substrates ranging from glass, to silicon and plastic, in quantities and over areas that exceed possibilities with conventional approaches.
Thursday, March 4, 2010
12:45 pm, HED 116
The scientific community is cordially invited.
2010
Dr. Tina Salguero
HRL Laboratories, LLC
Malibu, CA
“Molecules and Materials for 21st Century Needs”
Abstract
With our perspective at the beginning of a new decade, it seems clear that the 21st century will be an age when custom-tailored molecules and materials will reach an unprecedented level of importance. In this talk, I will describe several examples of custom-tailored molecules and materials that range across the fields of organometallic chemistry and materials science and have applications in catalysis, chemical synthesis, and energy production.
Tuesday, March 2, 2010
1:15 pm, HED 116
The scientific community is cordially invited.
2010
Dr. Rusen Yang
School of Materials Science and Engineering
Georgia Institute of Technology
Atlanta, GA
“Nanogenerators for Self-Powered Nanosystems”
Abstract
A self-powered nanosystem that harvests its operating energy from the environment is an attractive proposition for sensing, medical science, defense technology, and even personal electronics. Therefore, it is essential to explore innovative nanotechnologies for converting mechanical energy (such as body movement), vibration energy (such as acoustic/ultrasonic wave), and hydraulic energy (such as blood flow) into electric energy that will be used to power nanodevices without using battery. Piezoelectric zinc oxide nanowire (NW) arrays have been successfully demonstrated to convert nano-scale mechanical energy into electric energy. The operation mechanism of the electric generator relies on the unique coupling of piezoelectric and semiconducting dual properties of ZnO as well as the elegant rectifying function of the Schottky barrier formed between the metal electrode and the NW. This mechanism resulted in the DC nanogenerator driven by ultrasonic wave. Recently we achieved a new breakthrough with laterally-packaged single wire generator, which solved the transient contact issue in DC nanogenerator and produced power output from low frequency and irregular mechanical disturbance, such as finger tapping and running hamster. This presentation will introduce the fundamental principle of nanogenerator and its potential applications.
Monday, February 22, 2010
12:45 pm, HED 116
The scientific community is cordially invited.