Updated: May 14
Our next webinar will take place via the internet on Tuesday May 18th at 11AM EDT/4PM GMT. Sign up on our mailing list to receive the Zoom link!
We hope to see/hear from you all at one of our sessions or as one of the next speakers. If you are an early career scientist and would like to present your research, don't hesitate to submit an abstract today! For now, please learn more about our current speakers and their research below. We also thank the generous support from Cell Reports Physical Science.
Our featured speakers this week are Amelia Bunnell (undergraduate student, University of Florida, USA), Muhammad Abdullah (graduate student, University of Massachusetts Amherst, USA) and Dr. Abhigya Mookherjee (postdoc, University of Washington, USA). The seminar will be guest moderated by Dr. Minjung Son from the University of Wisconsin-Madison.
LEARN MORE ABOUT THE SPEAKERS AND THEIR TALKS BELOW
Amelia Bunnell (on twitter @AmeliaABunnell)
Biography: Amelia is a fifth-year undergraduate student at the University of Florida, where she will graduate with a Bachelor of Science in Biochemistry and Zoology in August 2021. Her undergraduate research is in organic geochemistry studying sample preconcentration and matrix removal via solid phase extraction for the analysis of amino acids with LCMS. A member of the UF Honors Program, Amelia attended H-Camp as an incoming freshman and served as a group leader the following year. Her proudest contribution to the Honors Program is the development of HP-Camp and Potterology.
Title of Talk: Potterology: A Muggle’s Guide to Making Sense of the Magic
Abstract: The University of Florida Honors Program is dedicated to building a sense of community and fostering a diverse and stimulating learning experience. Before the start of each Fall semester, incoming Honors freshmen have the opportunity to attend H-Camp, a three-day experience where they get a head start on connecting with their peers and learning about college life. For the last three years we have piloted an alternative to H-Camp, “HP-Camp,” a Harry Potter-themed potions class offered over a three-day period before the start of the Fall semester. A broad range of chemistry topics are covered in the course through Harry Potter-themed lab experiments and excursion classes like herbology. Students learn chemistry through unique experiments that are not part of UF’s traditional teaching labs as well as directly interact with a variety of faculty members at an early stage of their college experience. For the Spring 2021 semester, we expanded the program into a two-credit hour, full-term course. The 15-week course meets twice a week with a separate lecture and lab component. This extra time has allowed us to expand the experience to include more excursions like “Care of Magical Creatures.” The students have the opportunity to interact with faculty across multiple departments through guest lectures and excursions, making this a truly interdisciplinary experience. In this talk, we plan to discuss details of our programs and provide guidance to other educators looking to incorporate some magic into their curriculum.
MUHAMMAD ABDULLAH (on twitter @IamAB90)
Biography: Muhammad Abdullah graduated with a B.S. degree double majored in organic and biochemistry from Bahauddin Zakariya University, Pakistan in 2014, and obtained his M.S. in chemistry from Lahore University of Management Science (also known as LUMS), Pakistan in 2016. He is currently a Ph.D. candidate in chemistry working with Prof. Kevin Kittilstved at the University of Massachusetts Amherst where he employs elementary synthetic chemistry and spectroscopies to study Ti(IV)-based oxide colloidal nanocrystals possessing both the substitutional dopants and excess carriers. Muhammad loves teaching and he was recently honored with the campus-wide student-initiated Distinguished Lab Instructor Award in Chemistry.
Title of Talk: Reversible control over charge and spin dynamics of aliovalent magnetic dopants in Ti(IV)-based oxide nanocrystals
Abstract: One long-standing challenge in spintronics and quantum information processing is the design of new materials with tunable electron spin properties and dynamics. We combine synthetic chemistry with myriad of structural and spectroscopic techniques to study Ti(IV)-based oxide nanocrystals with tunable carrier densities that possess substitutional aliovalent magnetic dopants. In our initial efforts we found that the choice of precursor and its controlled hydrolysis play a vital role in the successful dopant incorporation. This key finding enables the successful doping of colloidal nanocrystals of SrTiO3, BaTiO3, and TiO2 with an array of aliovalent paramagnetic ions at substitutional Ti-sites. We further explored the interplay between dopants and photochemically-added excess electrons that localize at paramagnetic Ti3+ defects. Using variable temperature EPR spectroscopy, we observe drastic acceleration of the spin relaxation time of substitutional Cr3+ dopant ions with the incorporation of fast-relaxing Ti3+ defects through an efficient cross-relaxation processes. While investigating the generality of the drastic dopant-defect interaction, we discovered that other dopants such as Fe3+ behave differently in the presence of Ti3+ and instead appear to act as electron storage center. These results provide a new design strategy and simple post-synthetic method to rapidly manipulate the properties of redox-active dopants in Ti-based metal oxide semiconductor nanocrystals.
DR. ABHIGYA MOOKHERJEE (on twitter @AbhigyaMB)
Biography: The constant in all my research endeavors is to solve real-world chemistry problems. I built the muscle required by training with a pioneer of mass spectrometry (MS). In my PhD work with Dr. Peter Armentrout, I studied peptide fragmentations. With the Kevlar of fundamental chemistry, I switched gears to attack applied problems in glycomics. After completing my PhD, I joined Dr. Miklos Guttman’s lab. Here I develop MS-based tools to resolve isomeric protonated glycans. Outside the lab, I organize Science-on-Tap, a café for anyone eager to explore latest ideas in science and travel to new places both locally and internationally.
Title of Talk: Decoding Protonated Carbohydrates by Mass Spectrometry and More
Abstract: Glycans or just sugars decorate more than 70 % of proteins. They are implicated in many biological processes, including in diseased conditions, which necessities our understanding of glycosylation However, glycans exhibit incredible structural diversity. They may exist in several isomeric forms arising from different monosaccharide units joining them, bonding between these units, and branching patterns. Moreover, glycan bearing peptides are typically ionized as protonated ions in mass spectrometry (MS) workflows where protonated glycans are commonly observed diagnostic ions. However detailed structural elucidation of protonated glycans is made challenging by the different isomers they form in gas-phase. Efficient separation of the protonated isomers is analytically challenging by MS alone and requires tools with elaborate sample manipulation. In fact, there is limited structural information on the diagnostic ions often observed in LC-MS experiments. The first step in achieving my Napoleonesque objectives was resolving and determining structures of isomeric glycan fragments commonly observed in typical glycoproteomics experiments. We have demonstrated that two orthogonal tools, ion mobility (IM) and gas-phase hydrogen deuterium exchange (HDX) along with tandem MS (MSn) can resolve subtly different isomers. MSn was performed on two sets of protonated oligosaccharides – one that differ in the linkage between the monosaccharides, and another in the non-reducing end monosaccharide composition and linkage. Along with water loss from the reducing end, we found evidence of the formation of B/Y fragments in both sets of disaccharides. MSn revealed characteristic differences in fragmentation patterns of the water loss products and the Y fragments, that are dependent on the original linkages and non-reducing monosaccharide residue. IM revealed differences in the structures of the water loss products formed from differently linked disaccharides, revealing multiple conformations for some saccharides. Distinct deuterium uptake of the isomeric glycans obtained from gas-phase HDX also confirmed the presence of multiple structures for the water loss products. LC-MS/MS experiments of the water loss and Y product ions reveal subtle differences indicative of the novel and remarkable memory of the stereochemistry of the precursor that is preserved even post fragmentation. Reducing the ambiguity in assigning glycan structures can break-open new frontiers in glycoproteomics.