Lewen Yang successfully defended his thesis, “Line tension assisted membrane permeation at the transition temperature in mixed phase lipid bilayers” in Fall 2017. Lewen’s thesis committed was led by James T. Kindt with Joel Bowman and Michael C. Heaven as additional members.
During his time at Emory, Lewen worked on explaining a phenomenon that was first observed in the early 1970’s, that ions can move more quickly through lipid bilayers when the temperature is close to the bilayer’s melting point. At that temperature, zones of ordered lipids, which are very hard to pass through, exist next to zones of disordered lipids. The experiments suggest that the presence of the ordered lipids make the disordered lipids even more permeable than they would be on their own. The explanation proposed originally, and widely cited still, is that the boundary between these zones is exceptionally leaky. Lewen performed simulations on a highly simplified model that pointed to a different explanation – that leakage doesn’t actually occur at the interfaces themselves, but rather that the line tension of the interface exerts a tension on the disordered lipids that makes them more permeable. He followed up this study with demonstrations, using a more realistic model, that the effect of the interface on the energy barrier to permeation could be predicted quantitatively. His work has opened up a whole new perspective on an interesting phenomenon that is relevant to efforts to use thermally activated lipid containers for targeted drug release.
Lewen started a postdoctoral fellowship at the University of Delaware with Prof. Ed Lyman in April, where he continues to use molecular simulation to understand lipid phase behavior.
Liangbing Fu successfully defended his thesis, “Expanding the Scope of Reactions and Applications of Donor/Acceptor Rhodium(II)-carbenes” on Tuesday, November 22nd, 2016. Liangbing’s thesis committed was led by Huw Davies with Simon Blakey and Lanny Liebeskind as additional members.
Earlier this year, Liangbing received the Quayle Advanced/Senior Student Award. During his time at Emory, he published four first-author papers, among others. His first author paper in JACS expanded the scope pf Donor/Acceptor carbene C-H insertion reactions to include relatively electron-deficient substrates.
Liangbing is currently a postdoctoral scholar at Georgia Tech.
Research from Emory’s Emerson Center for Scientific Computing has been highlighted by Chemical and Engineering News. The research, the result of a collaboration between the Emerson Center’s Djamaladdin D. Musaev and the Kenichiro Itami at Nagoya University in Japan, involves Cu-catalyzed C-H imidination. The article, “Onward to simpler C–H functionalizations” appears in the November 07-08 issue of Chemical & Engineering News both in print and online.
Yang Liu (Salaita Group) is bringing new techniques to the emerging field of mechanobiology; at the same time, he’s returning to his roots.
Literally. As in, plants.
Yang’s father is an academic biologist studying agriculture in China.
“I think in the beginning, my dad really wanted me to be a biologist,” says Yang. “But normally kids don’t want to pursue the same career path as their parents.”
As an undergraduate in China, Yang started out studying mechanical engineering. Then, he attended a general chemistry lecture with a famous chemistry professor who made a convincing case for the importance of the discipline. “He said, ‘chemistry is the central science connecting physical sciences, life sciences and applied sciences all together,’’ says Yang. “And I was so fascinated by it. And I changed my major.”
At Emory, Yang joined the lab of Khalid Salaita. His research in the Salaita Group takes a novel approach to a common scientific question: how does the immune system recognizes and eliminates “invaders”, such as pathogens or cancer cells? Most research explores how chemical signals mediate this process. Yang’s work expands on existing work in the Salaita Group that focuses on mechanical signaling—the way that immune cells physically probe their targets within the body. “Cells can touch and apply forces to one another,” explains Yang, a process he refers to as a “handshake.” Yang’s research develops tools that allow scientists to “see” these kinds of physical interactions.
Specifically, Yang has developed a technique named molecular tension fluorescence microscopy (MTFM) that employs single elastic molecules—DNA, protein, and polymer— as sensors to visualize membrane receptor mediated forces at the piconewton level. “One piconewton is the weight of one trillionth of an apple and surprisingly, pN forces regulate biochemical signaling pathways,” says Yang. These forces are too small for scientists to measure using conventional methods. Existing tools aren’t sensitive enough or they are inefficient.
“Until our method kicks in,” says Yang.
Yang has combined nanotechnology and the “easy” surface chemistry of gold nanoparticles to make MTFM probes more effective. “These gold particle sensors are spring scales at nanoscale ,” says Yang. “Compared to previous techniques, these probes are of significantly enhanced sensitivity, stability and amenable for detecting forces mediated by almost all kinds of cell receptors.”
The improvements have caught the attention of researchers in other Emory units—and even nationally and internationally. Yang has collaborated with the Evavold Lab in the Department of Immunology at Emory to help them measure mechanical forces mediated by different immune cells. He also has collaborators from as far away as New York and Germany.
Regarding these collaborations, Yang says: “The need to be trained [to use this method] is very high. The method is not hard, it’s easy. So people usually spend a few days and they should be able to master it…and we still maintain quite tight collaboration. We not only teach them how to make it, we actually get involved in the scientific questions they care about and continue this collaboration.”
Recently, Yang’s success in developing the new method was recognized with the department’s highest graduate student honor, the Quayle Outstanding Student Award. Speaking of Yang’s progress shortly after the award ceremony, advisor Khalid Salaita praised Yang’s work ethic as well as his science: “Yang was a real pleasure to have in the lab. He was incredibly thoughtful, well read, and intensely motivated. More than anyone else I’ve worked with, Yang displayed a keen instinct for experimental design. He spent countless hours in the dark microscope room collecting data and working around the clock fueled up with his favorite bbq Pringles and excited by the science.”
The award ceremony was followed swiftly by another milestone—a successful PhD defense. Next, Yang is headed to John’s Hopkins University where he will work in the lab of Dr. Taekjip Ha, a world leader in the development of single molecule fluorescence microscopy and force spectroscopy.
Yang’s pioneering research wasn’t always smooth sailing. “I didn’t get my first experiment done until the first semester of my third year. Everything before that didn’t work.” He credits his perseverance to his father’s example—“agriculture is even slower, waiting for the growth of plants. You can only do two experiments a year!”—as well as his own scientific curiosity. His advisor, Khalid Salaita, was also an inspiration throughout the process. “He is always passionate and ignited my love for science. You love it and you work hard to make something meaningful to the society and also make yourself valuable, so, that’s what I’d like to do and that’s because of these two people.”
Does all this mean that Yang has overcome his initial reluctance to follow in his father’s footsteps towards biology?
“I think I’m going back to the route, mining chemistry, biology. In the beginning I was against it, but I do like it.” Still, chemistry has his heart. “Chemists not only create new tools, new theories and new materials, but also create new opportunities. And if you want to study biology as a chemist, there are some advantages too because you can understand and explore the secret of life at the molecular level.”
Joshua Bartlett successfully defended his thesis, “Electronic and Photoionization Spectroscopy of Heavy Metal-Containing Diatomic Molecules” on Tuesday, September 27th, 2016. Drew’s thesis committed was led by Michael C. Heaven with James T. Kindt and Susanna Widicus Weaver as additional members. Joshua will begin a postdoctoral appointment at Los Alamos National Lab in October. Congratulations, Joshua!
When Chris Curfman (00G) entered Emory, he could not have imagined where he would end up two decades later. After completing a PhD in chemistry, Chris shifted his focus away from academic research to pursue a career in intellectual property law. Since then, he has been named a Georgia Super Lawyers “Rising Star” by Atlanta Magazine and became a founding member of Meunier Carlin & Curfman, which has since evolved into one of the largest intellectual property firms in the Southeast. In a climate where more PhD students pursue careers outside the professoriate, Chris’ story is an inspiration. “While we are all united by our intellectual curiosity and our love of science, this common drive can diverge into various fulfilling careers,” says Chris. From his trials and triumph with his research at Emory to his self-discovery and transformation into the rising star that he is today, Chris has accumulated a vast wealth of memories and insight, which is highlighted in this edition of Alumni Spotlight.
During graduate school, Chris joined the lab of Dennis C. Liotta, who would have a profound impact on his trajectory. Chris undertook a particularly difficult thesis project working with sphingolipid analogs. The process of constantly overcoming challenges instilled in him the crucial lifelong value of perseverance that would later prove pivotal outside of the lab. This determination was also critical in prevailing over another personal challenge. While Chris had always fostered a passion for teaching, he grappled with a fear of public speaking. As one of the graduate qualification exams, he was required to present his research in front of the entire Department of Chemistry student body. He recalls that he would “enter the conference room when it was empty and practice over and over again.” He went on to deliver a successful talk. Invigorated by this positive experience and his innate passion for teaching, Chris began to actively seek out opportunities for public speaking, which paved his way to standing on the podium of Emory law school as an adjunct professor.
Nonetheless, Chris’s time at Emory was not “all work and no play.” Chris has fond memories of his time as the president of the Pi Alpha Chemical Society. He recalls organizing graduate events, such as movie nights and picnics, to promote social interaction and collaboration amongst graduate students. To him, “It was a fun and great environment. It was a place where you could set aside the work and just talk and socialize.”
During Chris’ last year of graduate school, his advisor began to take notice of his skill at technical writing and public speaking, as well as his proficient interpersonal skills. Realizing that Chris’ skill set complemented the profession of patent law, Liotta catalyzed Chris’ foray into the world of patent law by inviting him to events where he could network with established lawyers. It was at one of these events that Chris had a fateful meeting leading to an interview offer. That was an electrifying time in Chris’ life. Within the span of that final summer in graduate school, Chris managed to simultaneously complete 3 milestones: defending his PhD, gaining acceptance into law school, and receiving a job offer working in a law firm.
After Chris completed his J.D. at Georgia State University, he practiced several years at a small intellectual property firm. However, that firm was acquired by a much larger general practice and Chris found himself at a crossroads. Chris felt that the large firm business model did not align with his own passions and goals. Chris wanted to retain the close relationships with his clients and have the opportunity to devote more time and attention to their needs, yet he found this more difficult in a large general practice firm. It was at this pivotal moment that Chris received a life-changing phone call from a former colleague who shared a similar vision. That initial conversation ultimately blossomed into a group of eight like-minded patent lawyers who pooled together their resources and brought their vision to a new company. When asked about his emotions at this time, Chris said, “this was both a thrilling and terrifying period in my life. I had to invest everything I had into this venture, including putting my life savings on the line, but I could finally do what I had originally set out to do.” At long last, he had the autonomy to become the champion he had dreamed of becoming for clients who must navigate the treacherous waters of patent law.
It has been nearly two decades since Chris made that decision to transition from lab work to law, but all the lessons he learned during graduate school still serve him well today. Chris says that he finds his current profession to be fulfilling and fun, and he feels fortunate to be involved in a career that allows him to intersect science with people, especially being in a position to be able to help others achieve their goals. When asked what words of advice he would give to current graduate students, he implored encouraged them to “never give up, finish their Ph.D., practice public speaking and effective writing, and network whenever you can.” Chris’ journey serves as an inspiration for the next generation of students looking to apply their doctoral studies to broader society.
Yuan Chang is currently a graduate student in the lab of Dr. Khalid Salaita. She entered Emory in 2011 and has been studying live cell tension using molecular tension fluorescent microscopy (MTFM).
I had the pleasure of spending this past summer at the University of Pennsylvania in the lab of Professor Daniel J. Mindiola as a visiting scholar. My time in the lab was insightful and inspiring; I worked with some brilliant minds on some fascinating chemistry and left with a new knowledge of lab techniques and fond memories.
Having visited Philly briefly just once before, I wasn’t quite sure what to expect of the city. I was pleasantly surprised at how vibrant and friendly West Philadelphia welcomed me. City streets were trafficked by commuters and delicious food trucks. In order to keep my close relationship to the food trucks healthy, I began to run every evening.
Fairmount Park and the Philadelphia Park system is the largest landscaped urban park in the world and I explored a good bit of it during my stay. I also ran with the West Philly chapter of BoMF (Back on My Feet) on Monday mornings and participated in the Papa Gary 10k that finished at the historic Rocky Steps!
When I wasn’t running off the calories to keep a Kfoodtruck, I was adapting to the new layer of neoprene hugging my hands and arms. I worked with Group IV metals with the goal of creating nitride complexes supported by a varying PN ligand. Working with highly pyrophoric compounds taught me valuable safety protocol and also some new techniques (Electron Paramagnetic Resonance, Variable Temperature NMR, et al.). The bulk of my synthetic trials involved scaling up varying PN ligands and the constructing the complexes supported by these ligands. I began with Titanium and the Mesitylene substituted PN ligand and later worked with the 1,3,5-triisopropylbenzene substituted PN Ligand in hopes of obtaining better crystals further down the synthesis. I also experimented my trials with Hafnium and Zirconium, below are some x-rays of aforementioned complexes.
The workload in the Mindiola Lab was intense, but the people were friendly and supportive. Through our countless hours in lab, we developed a covalent level of friendship and I am looking forward to the point where our careers cross paths again.
My last day at Penn, a few of us drove to the MetLife Stadium in the boss’s Passat and watched the sold-out FC Bayern Munich vs. Real Madrid match with 82,000 other soccer enthusiasts. It was the perfect outing to celebrate a summer of hard work and breakthrough (Real unsurprisingly won).
Juan D. Cisneros (pictured far left) is a chemistry and Spanish double major at Emory from Coconut Creek, Florida. Previously, he wrote for The Lab Report about his experiences studying abroad in Salamanca, Spain. Juan is also an IMSD undergraduate scholar and edits the IMSD blog.
Leah Williams came to Emory last summer at the same time that students, staff, and faculty were moving into the new Atwood Addition. Her arrival in the midst of that process seems fitting—as an HHMI Curriculum Development Postdoc, Leah is a part of the team working to re-envision the undergraduate chemistry curriculum at Emory.
The curriculum itself is designed, in part, to suit the unique teaching opportunities presented by the new addition. “Everything that we’re working on has been designed with the ATOMIC (Advancing the Teaching Of Matter through Innovation and Collaboration) room in mind,” says Leah. “A lot of the materials we’re creating are meant to be done in groups, they’re meant to be interactive. Taking advantage of that space, taking advantage of the round tables, the Learning Catalytics system (since we have screens everywhere), the dry erase boards and tables so they can share all their information.”
Before coming to Emory, Leah received her PhD in chemical education from Michigan State University. Her research focused on evidence-based methods for teaching students about the relationship between structure and properties. “It’s one of the bigger ideas of chemistry that the structure of a compound, of a substance determines the properties that you experience on the macroscopic level. It’s hard [for students] because it’s a very big jump from structure to properties and there is a lot you need to know in-between. “
At MSU, she assisted her advisor, Dr. Melanie M. Cooper, with the implementation of a revised general chemistry course called CLUE: Chemistry, Life, the Universe, and Everything. The changes were modeled on revisions made to general chemistry coursework at Clemson University. Leah actually began her PhD at Clemson, moving to MSU with her advisor when the opportunity arose to bring the curriculum revisions undertaken at Clemson to a new school.
Her experiences at MSU and Clemson inform Leah’s work at Emory. “Leah brings a wealth of expertise to our reform efforts,” says Tracy McGill. “Her experience with the NSF-sponsored CLUE curriculum, assessment, and design of learning activities has been invaluable to the Emory Chemistry department. She just finished her first year in the ATOMIC room and her insights about student learning have informed the changes we have already made in planning for the fall of 2016. It is a great pleasure to work with a colleague with such dedication and enthusiasm to our department and especially our students.”
Leah notes that the curriculum development underway at Emory has a key difference from her previous experiences. “It was just gen chem,” she explains, speaking of Clemson and MSU. “Here, we’re working on the whole curriculum. There are very few schools that have attempted this.”
That process presents unique challenges. For one thing, there aren’t many examples to draw on. For departments hoping to complete evidence-based curriculum overhauls in the future, Emory’s story will be part of the evidence—what works and what doesn’t.
The curriculum redesign started with a focus on big ideas—the themes tying together different courses throughout a student’s career. The approach allowed everyone to think big, but it was hard to zoom in on the details of individual courses. “Now,” says Leah, “we’ve flipped our approach and we’re working the other way.” The team is focusing on individual lessons and learning approaches, building the curriculum piece by piece. “Our goal is to give people a more concrete idea of what the courses are actually about. I think before it was very abstract and it’s hard to get people on board when they can’t envision themselves teaching that class because they’re not sure what’s in that class. Now, we’re working on more detail, but that takes time.”
Although the process is ongoing, undergraduate chemistry students are already seeing the influence of the curriculum redesign in the classroom as members of the faculty test activities from the under-development curriculum in the classroom. Leah worked with instructor Michael Reddish to test a version of the advanced physical chemistry lab designed to help students produce publishable research results. This Fall, the curriculum team will pilot an activity on potential energy and attractive forces that will have students in the ATOMIC room up on their feet: “The students struggle a lot understanding how potential energy is related to the attractive and repulsive forces between charged particles. So, we developed an activity where they’re going to run around and they’re going to have charges…this person is going to be a plus charge and this person will be a minus and we’re going to talk about what happens when they come together or they are further apart.”
The curriculum redesign centers on this kind of active engagement. Leah says that college students are “at the point where they can understand more complex ideas, deeper chemistry concepts, and they’re at that transition where they’re starting to take more responsibility for their own education and willing to put in the work to learn the hard stuff.” When she moves on from Emory, Leah hopes to continue teaching at the college level. “I like that transition, setting them off for harder chemistry studies as they go on.”
Doug Mulford’s Fall 2016 course, “How Do We Know That? 2,500 Years of Great Science Writing”, has been featured by Emory News as a “critical” course offering a fresh perspective on high profile issues. From the article:
How Do We Know That? 2,500 Years of Great Science Writing
Instructor: Douglas Mulford, senior lecturer, Chemistry
Cool factor: What did Darwin actually say? Einstein? Mendel? Should we clone humans? Can chocolate cause weight loss? What is the placebo effect anyway and why do I care? Was Galileo just a really big nerd? (Yes!) The course will look at how humans learn by looking at the original words of scientists throughout history. Occasional demonstrations, explosions and liquid nitrogen ice cream provided.
Course description: This is not a science class but scientific learning will be the framework for this study. This discussion-based first-year seminar will focus on how humans have learned knowledge throughout the history. Discourse will examine humans’ ways of discovery by looking at 2,500 years of great science writing to discover how science is done and how human knowledge as a species grows.