Monday, February 27, 2017
10:00 AM to 03:00 PMConference/Symposium - Clough Undergraduate Learning Center - It's All About Math and Science
It's All About Math and Science
We invite high school students (and their guests) who are interested in learning about undergraduate degree programs in the College of Sciences at Georgia Tech to attend the open house "It's All About Science and Math." Visitors will learn about opportunities in the degree programs listed below, receive information about admission requirements and financial aid, attend a class, and tour scientific facilities/labs and parts of campus. This program is free to visitors and guests. Due to limited space, participants are encouraged to sign up early. To schedule a class or group visit, please contact Dr. Cameron Tyson. For more information, please see: http://scienceandmath.gatech.edu/
04:00 PM to 05:00 PMSpecial Seminar - MoSE G011 - Prof. Christopher N. Bowman
Clicking Polymers Together: Assembly of Complex, Controlled Polymer Structures from Efficient Chemistries
A new paradigm encompassing several distinct chemical reactions and, more importantly, a generalized approach to molecular design and synthesis has been rapidly adopted in the fields of chemical synthesis, biotechnology, materials science, drug discovery, surface science, and polymer synthesis and modification. The Click Chemistry paradigm focuses on implementation of highly efficient reactions that achieve quantitative conversion under mild conditions. As such, these reactions represent ideal candidates for further development, understanding and implementation. In particular, the synergistic combination of these click chemistries with photochemical initiation and polymer formation has been used to afford 4D control of polymer formation, structure and patterned assembly. Here, we will focus on three distinct vignettes related to our implementation of photoclickable polymer systems. The first of these focuses on the development of covalent adaptable networks (CANs) where the ability to controllably alter the network structure is used to alter topography and other material properties by forming materials which can be switched revesibly from elastic to plastic simply by exposure to light. Secondly, we will focus on the development of approaches to photoinitiate the Cu(I) catalyzed azide-alkyne cycloaddition (CuAAC) click reaction. Here, implementation of this reaction in surface modification, hydrogel formation, and lithography as well as in the development of a new class of photopolymerization reactions will be presented. Finally, the development and implementation of click nucleic acids (CNAs) based on the thiol-ene click reaction will be presented. This distinct class of oligonucelotides combines the vast advantages of synthetic oligonucleotides such as peptide nucleic acids with the power of click reaction chemistry to form materials that hybridize with both natural and synthetic olignonucleoitides via Watson-Crick base pairing while being simple to produce in large scales appropriate for directed assembly and other high value materials applications.
Tuesday, February 28, 2017
04:00 PM to 05:00 PMBiochemistry Division Seminar - MoSE 3201A - Prof. Jennifer DuBois
Chemistry without cofactors: Microbial strategies for important catalyses and what we can learn from them
We have become increasingly interested in biochemical reactions with O2 and CO2 that, in defiance of conventional wisdom and precedent, do not occur through the agency of a protein-bound cofactor (metal, flavin). Instead, the protein environment on its own is sufficient to catalyze the reaction. Understanding how this is achieved gives us ideas about how proteins or synthetic catalysts could be designed to catalyze reactions that were believed to be obligately cofactor-driven. Cofactorless reactions also have practical applications, since cofactor generation, insertion, and stabilization usually complicate or limit the lifetime of biocatalysts in reactors. I will aim to compare two examples - one with a metallosubstrate (coproheme) and one fully organic.
Wednesday, March 01, 2017
11:00 AM to 12:00 PMSpecial Seminar - Student Center Theater - Conversations with Senior Leadership Series
The Future of Higher Education and Georgia Tech
04:00 PM to 05:00 PMSpecial Seminar - MoSE 3201A - Prof. Chuanbing Tang
Sustainable Polymers from Biomass and Antimicrobial Metallopolymers
Sustainable chemicals, polymers and materials are gaining tremendous momentum at various levels, though there are numerous nontrivial challenges for preventing them to be more competitive with petroleum counterparts. On the other hand worldwide bacterial resistance to conventional antibiotics has consistently caused public panic with infectious disease outbreaks by superbugs. This presentation will cover our efforts on both frontiers. The first half details research on the judicious combination of robust chemistry and macromolecular architectures in converting renewable biomass such as plant oils and resin acids into platform monomers and polymers using eco-friendly, atom-efficient and economy-viable approaches. A few case studies are given to prepare tough bioplastics and mendable elastomers. The second half of this talk focuses on the synthetic methodologies of a class of cationic metallocene polyelectrolytes and on the conceptualization of novel robust antimicrobial biomaterials using metallopolymer-antibiotic bioconjugates, which have shown surprising promise against some of most malicious bacteria using a strategy to revitalize conventional ?-lactam antibiotics such as penicillin and amoxicillin. References: Yao K.; Tang C. Controlled Polymerization of Next-Generation Renewable Monomers and Beyond. Macromolecules, 2013, 46, 1689-1712. Yuan L.; Wang Z.; Trenor N. M.; Tang C. Robust Amidation Transformation of Plant Oils into Fatty Derivatives for Sustainable Monomers and Polymers, Macromolecules, 2015, 48, 1320-1328. Ganewatta M. S,; Ding W.; Rahman M. A.; Yuan L.;, Wang Z.; Hamidi N.; Robertson M. L.; Tang C. Biobased Plastics and Elastomers from Renewable Rosin via "Living" Ring-Opening Metathesis Polymerization, Macromolecules, 2016, 49, 7155-7164. Zhang J.; Chen Y.-P.; Miller K. P.; Ganewatta M. S. Bam M.; Yan Y.; Nagarkatti M.; Decho A. W.; Tang C. Antimicrobial Metallopolymers and Their Bioconjugates with Antibiotics against Multidrug Resistant Bacteria, J. Am. Chem. Soc. 2014, 136, 4873-4876. Dr. Chuanbing Tang received B.S. from Nanjing University, and Ph.D. from Carnegie Mellon University with Profs. Krzysztof Matyjaszewski and Tomasz Kowalewski. He was a postdoctoral scholar at the University of California Santa Barbara with Profs. Craig J. Hawker and Edward J. Kramer. On August 2009, he joined Department of Chemistry and Biochemistry at the University of South Carolina. Currently he is a College of Arts and Sciences Distinguished Professor. His research interests focus on organic polymer synthesis, sustainable polymers from biomass, metal-containing polymers, and polymers for biomedical applications. He has been recognized with a few awards including Presidential Early Career Award for Scientists and Engineers (PECASE), South Carolina Governor's Young Scientist Award for Excellence in Scientific Research, NSF Career Award, Thieme Chemistry Journal Award, and USC Distinguished Undergraduate Research Mentor Award. He has also been named a Breakthrough Rising Star at the University of South Carolina and an ACS PMSE Young Investigator. He serves on a few journal editorial advisory boards including major leading polymer journals such as Macromolecules, ACS Macro Letters, Macromolecular Rapid Communications, Macromolecular Chemistry and Physics, and Polymer. He has co-edited one book and published over 100 papers, 9 patents, and 5 patent applications.
Thursday, March 02, 2017
04:00 PM to 05:00 PMColloquium - MoSE G011 - Prof. Ruma Banerjee
Signaling through Hydrogen Sulfide
Hydrogen sulfide is a signaling molecule that is toxic at high levels. We have demonstrated that the H2S-producing enzymes are remarkably promiscuous and that allosteric mechanisms exist to switch their reaction specificity. The sulfide oxidation pathway resides in the mitochondrion, generates reactive sulfur intermediates, and couples to the electron transfer chain, thus making H2S the only known inorganic substrate for ATP synthesis in mammals. Our discovery of novel heme-dependent sulfide oxidation chemistry will be discussed along with a proteomic approach that is revealing persulfidation targets in colon, which is routinely exposed to high sulfide concentrations from sulfate reducing bacteria in the microbiome.
Friday, March 03, 2017
09:00 AM to 12:00 PMSpecial Seminar - Room 1116 Marcus Nanotechnology Building - Dr. Paige Jarreau
Social Media for Scientists and Engineers
Are you curious about social media, but unsure how to maximize your effectiveness, or wonder if your investment in social media is worthwhile? To address these questions, Georgia Tech ADVANCE Professors Kim Cobb for the College of Sciences, and Dana Randall, for the College of Computing, have organized a half-day workshop. In this workshop you will: learn about the latest research on the pros and cons of social media use by STEM professionals (Should you do it?) share and discuss strategies for effective engagement with colleagues and seasoned social media experts (How should you do it?) design a strategy for your own effective engagement, including identifying audience and key messages (Let's do it!) Register here. Paige Jarreau, science communication specialist at Louisiana State University, will keynote the workshop with the talk: "Social Media: Engaging for Impact in STEM Fields."
Monday, March 06, 2017
11:00 AM to 12:00 PMBiochemistry Division Seminar - IBB Suddath Seminar Room - Prof. Jason DeRouchey
DNA in tight spaces: Linking structure, stability and protection in cation packaged DNA
Packaged DNA is ubiquitous in nature and the laboratory with examples ranging from chromatin, viruses, sperm cells, bacterial nucleoids, artificial viruses and gene therapy constructs. Sperm nuclei are one of the best examples of in vivo maximum DNA compaction and therefore an ideal model system to study biophysically. Despite intense research, the physical mechanisms underlying tight packaging of DNA remain poorly understood especially at the molecular level. Spermiogenesis is a unique multi-step process resulting ultimately in the replacement of histones by protamines in sperm nuclei to a final volume roughly 1/20th that of a somatic nucleus. The near crystalline organization of DNA in mature sperm is thought crucial for both DNA delivery and the protection of genetic information due to the absence of DNA repair. In this talk, I will first discuss our past studies on understanding how cations modulate DNA-DNA forces in the condensed phase and the interrelationships between cation chemistry, packaging densities and compaction. The last half of my talk will discuss recent experiments aimed at understanding the various biological implications for both protamine-DNA packaging and correlations to infertility and oxidative stress in sperm chromatin. Biography Jason DeRouchey is an Assistant Professor in the Department of Chemistry at the University of Kentucky. He received his B.S. degree in Chemistry from the University of Texas at Dallas in 1996. Professor DeRouchey then obtained a MS and PhD in Polymer Science and Engineering at the University of Massachusetts-AmHerst. He first began working with questions of dynamics and DNA as a Alexander von Humboldt Fellow working with Joachim R?dler at the Institute of Experimental Physics at the Ludwig Maximilians Universit?t (LMU) Munich. Dr. DeRouchey then joined the Laboratory of Physical and Structural Biology at the National Institute of Child Health & Human Development (NICHD) at the National Institutes of Health (NIH) as a IRTA fellow working with V. Adrian Parsegian
04:00 PM to 05:00 PMSpecial Seminar - MoSE 3201A - Prof. Anne S. Meyer
Bio-architecture: from protective biocrystals to patterned biomaterials
In stationary phase bacteria cells, Dps (DNA binding protein from starved cells) is the most abundant protein component of the nucleoid. Dps compacts DNA into a dense structure, and the deletion of Dps has wide-ranging effects on the levels of protein expression in stationary cells. We have applied RNA-Seq techniques to measure the global effects on transcription associated with Dps-induced compaction of DNA. Strikingly, we found virtually no significant changes in mRNA levels in stationary-phase cells. Additionally, we measured the in vitro activity of RNA polymerase on DNA compacted by Dps, and we found no meaningful change in either transcriptional initiation or transcriptional elongation. We are therefore forced to conclude that Dps does not affect stationary-phase transcription either directly or indirectly in the cell. Instead, Dps provides a mechanism to compact and protect DNA that is orthogonal to transcription, and changes in protein expression associated with Dps must be caused by changes in translation or degradation of these proteins. Recently, the Meyer lab has started a new line of research targeted at re-engineering bacteria to synthesize bio-inspired materials with improved properties. This approach has the potential to replace traditional chemical approaches that require extreme environmental conditions, expensive equipment, and the generation of hazardous waste. As a first step we have targeted bacterial production of patterned artificial nacre, a biomineralized material lining seashells that combines high mechanical strength with high fracture toughness. We are currently able to deposit layers of crystallized calcium carbonate via bacterial action in alternation with bacterially-synthesized organic polymers. Our visibly layered composite materials represent a breakthrough in the fabrication of tunable, environmentally-friendly materials. Combination of our biological materials-producing systems with our newly developed 3D bacterial printers will allow the rapid and straight-forward production of spatially structured biomaterials. Dr. Anne S. Meyer is an Assistant Professor in the Department of Bionanoscience at TU Delft in The Netherlands. Dr. Meyer received her Ph.D. in Biological Sciences at Stanford University (USA) in 2005. Before joining TU Delft, she was a post-doctoral fellow in the Department of Biology at the Massachusetts Institute of Technology (USA). Her research focuses on using quantitative techniques in the fields of biophysics, biochemistry, and microbiology to study structural dynamics, macromolecular interactions, and physiological responses of organisms to environmental stressors. She also uses tools of synthetic biology to engineer novel functions into microorganisms, with a particular focus on the production of improved biomaterials and the development of new pathways for inducing transcriptional responses.
Tuesday, March 07, 2017
04:00 PM to 05:00 PMInorganic Division Seminar - MoSE 3201A - Prof. Efrain Rodriguez
New Layered Transition Metal Chalcogenides as Functional Materials
We present a new set of layered materials that, unlike transition metal dichalcogenides, are built of square metal lattices leading to new functional properties such as unconventional superconductivity and ferromagnetism. Due to the weak van der Waals interactions that hold the chalcogenide layers together, intercalation chemistry in aqueous solutions can be utilized to prepare new phases with interesting magnetic and electronic properties. We will present our work on the synthesis, characterization, and structural studies via neutron and X-ray scattering of these layered materials. Our group's strategy has been to incorporate layers such as metal hydroxides to understand superconductivity in the iron chalcogenides such as (AOH)-FeCh materials where A is an alkali metal and Ch = S2- and Se2-. We will also present our studies of the cobalt analogues of these layered materials including synthesis of a metastable form of CoCh and its intercalated derivatives such as (AOH)-CoCh. Unlike the case of iron, the cobalt-based materials express weak ferromagnetism instead of superconductivity. We attempt to explain the stark changes in the properties from their electronic structures calculated utilizing density functional theory.
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