Bittersweet Transitions (From Georgia Tech to Johns Hopkins!)

As I have been mulling over my move to Johns Hopkins, the word that keeps cropping up again and again is "bittersweet." I look back at the 20 years that I spent with my family, my colleagues, my friends, and my group in Atlanta, and I feel the moroseness of the loss. We built our home here, our son was born here, my research group thrived here, and I was part of the team that raised the visibility and profile of Georgia Tech's School of Chemistry.

The funny thing about that rise is that it included faculty like me who started our careers at Tech, but it has also included a significant number of colleagues who moved to Tech after having established their research groups elsewhere. The latter came to Tech with an opportunity to reinvent themselves and their research groups. They also had a mandate to add to the growth of their new department. This is the sweet side of a move. Likewise, I am looking forward to reimagining a more agile research group solving problems across our core areas of research. I am also excited by possible new collaborations, and what I will learn from them. The practice of chemical research has increasingly become multi-disciplinary and collaborative. It's exciting to be on a new team, but it is still a bittersweet feeling as I will undoubtedly lose some of my ties to Georgia Tech.

At the stroke of midnight on June 30th, the transition will be complete. I will start my adventure with my new colleagues at Hopkins! The size of our undergraduate student population makes it feel like a primarily undergraduate institution that happens to be collocated with a world-class graduate research program. I look forward to being able to engage with students in smaller classroom settings just as I experienced during my Phi Beta Kappa lectures. I look forward to meeting with my new colleagues and collaborating on problems that I have not yet thought about. My research group is also moving quickly, and we will have the resources to advance the theory of chemical reaction rates and dynamical consistency in multiscale nonequilibrium approaches, while tackling challenges related to proteins, nanoparticles, colloidal suspensions and high-speed flows. Hopkins Chemistry has been moving up because of: many outstanding recent junior hires, many successes by mid-career and senior faculty, and emerging ties to other disciplines. It's an amazing opportunity to be a part of this growth!

So farewell to Georgia Tech and hello to Hopkins. This is an ending that has a beginning, and I am looking forward to what awaits.

Sustainable Nano on Open Access Sustainably

(This article is a cross-post between EveryWhereChemistry and Sustainable-Nano!)

Sustainability’s future is now. Our recent article was just published in an all-electronic journal, ACS Central Science, which is among the first of the American Chemical Society (ACS) journals offered without a print option. It therefore embodies sustainability as it requires no paper resources, thereby limiting the journal’s carbon footprint to only what is required for maintaining the information electronically in perpetuity. It is also completely Open Access, which means our article is available for all to read. Does this equal accessibility (called “flat” because there is no hierarchy in levels of access) amount to yet another layer of sustainability? More on that question in a moment. Meanwhile as the article itself is about sustainability, it embodies the repetitive word play in the title of this post.

But there is another double meaning in the publishing of this work: The flatness underlying the vision of Open Access is also at play in how the work was done. ELEVEN different research groups were involved in formulating the ideas and writing the paper. This lot provided tremendous breadth of expertise, but the flatness in the organizational effort allowed us to merge it all together. Of course, it wouldn’t have happened without significant leadership, and Cathy Murphy, the paper’s first author, orchestrated us all magnificently. While flatness in organizational behavior isn’t typically considered part of sustainability, in this case it provided for the efficient utilization of resources (that is, ideas) across a broader cohort.

So what is our article about? Fifteen years into the 21st century, it is becoming increasingly clear that we need to develop new materials to solve the grand challenges that confront us in the areas of health, energy, and the environment. Nanoparticles are playing a significant role in new material development because they can provide human-scale effects with relatively small amounts of materials. The danger is that because of their special properties, the use of nanoparticles may have unintended consequences. Thus, many in the scientific community, including those of us involved in writing this article, are concerned with identifying rules for the design and fabrication of nanoparticles that will limit such negative effects, and hence make the particles sustainable by design. In our article, we propose that the solution of this grand challenge hinges on four critical needs:

1. Chemically Driven Understanding of the Molecular Nature of Engineered Nanoparticles in Complex, Realistic Environments
2. Real-Time Measurements of Nanomaterial Interaction with Living Cells and Organisms That Provide Chemical Information at Nanometer Length Scales To Yield Invaluable Mechanistic Insight and Improve Predictive Understanding of the Nano−Bio Interface.
3. Delineation of Molecular Modes of Action for Nanomaterial Effects on Living Systems as Functions of Nanomaterial Properties
4. Computation and Simulation of the Nano−Bio Interface.

In more accessible terms, this translates to: (1) It’s not enough to know how the nanoparticles behave in a test tube under clean conditions as we need to know how they might behave at the molecular scale in different solutions. (2) We also need to better understand and measure the effects of nanoparticles at contact points between inorganic materials and biological matter. (3) Not only do we need to observe how nanoparticles behave in relation to living systems, but to understand what drives that behavior at a molecular level. (4) In order to accelerate design and discovery as well as to avoid the use of materials whenever possible, we also need to design validated computational models for all of these processes.

Take a look at the article for the details as we collectively offer a blueprint for what research problems need to be solved in the short term (a decade or so), and how our team of nanoscientists, with broad experience in making, measuring, and simulating nanoparticles in complex environments, can make a difference.

The title of the article is "Biological Responses to Engineered Nanomaterials: Needs for the Next Decade.” The work was funded by the NSF as part of the Phase I Center for Sustainable Nanotechnology (CSN, CHE-124051). It was just released at ACS Central Science, XXXX (2015) as an ASAP Article. The author list is C. Murphy, A. Vartanian, F. Geiger, R. Hamers, J. Pedersen, Q. Cui, C. Haynes, E. Carlson, R. Hernandez, R. Klaper, G. Orr, and Z. Rosenzweig,

It’s available as Open Access right now at http://dx.doi.org/10.1021/acscentsci.5b00182

LiCN taking a dip in an Ar bath

We all know that it’s easier to move through air than water. Changing the environment to molasses means that you’ll move even slower. Thus it’s natural to think that the thicker (denser) the solvent (bath), the slower a particle will swim through it. More precisely, what matters is not the density but the degree to which the moving particle interacts with the solvent, and this can be described through the friction between the particle and the fluid. Chemical reactions have long known to be increasingly slower with increasing friction. The problem with this seemingly simple concept is that Kramers showed long ago that there exists a regime (when the surrounding fluid is very weakly interacting with the particle) in which the reactions actually speed up with increasing friction. This crazy regime arises because reactants need energy to surmount the barriers leading to products, and they are unable to get this energy from the solvent if their interaction is very weak. A small increase of this weak interaction facilitates the energy transfer, and voila the reaction rate increases. What Kramers didn’t find is a chemical reaction which actually exhibits this behavior, and the hunt for such a reaction has long been on…

A few years ago, my collaborators in Madrid and I found a reaction that seems to exhibit a rise and fall in chemical rates with increasing friction. (I wrote about one of my visits to my collaborators in Madrid in a previous post.) It involves the isomerization reaction from LiCN to CNLi where the lithium is initially bonded to the carbon, crosses a barrier and finally bonds to the nitrogen on the other side. We placed it inside an argon bath and used molecular dynamics to observe the rate. Our initial work fixed the CN bond length because that made the simulation much faster and we figured that the CN vibrational motion wouldn’t matter much. But the nagging concern that the CN motion might affect the results remained. So we went ahead and redid the calculations releasing the constraint on the CN motion. I’m happy to report that the rise and fall persisted. As such the LiCN isomerization reaction rate is fastest when the density of the Argon bath is neither too small nor too large, but rather when it is just right.

The article with my collaborators, Pablo Garcia Muller, Rosa Benito and Florentino Borondo was just published in the Journal of Chemical Physics 141, 074312 (2014), and may be found at this doi hyperlink. This work was funded by the NSF on the American side of the collaboration, by Ministry of Economy and Competiveness-Spain and ICMAT Severo Ochoa on the Spanish side, and by the EU’s Seventh Framework People Exchange programme.

On my experience delivering a webinar...

I recently participated as a speaker in a Webinar for the American Chemical Society (ACS.) It was only the second webinar that I have delivered. My first was held on January 2013 as part of the monthly meeting series of the Lehigh Valley Local section of the ACS. They were an early adopter of the medium. That is, they were quick to figure out that it's cost effective to host speakers from a distance while also addressing a greater number of their members. The latter is particularly important to them because they cover a large geographic area placing any particular choice of meeting location too far from most of their members. My host, Lorena Tribe, helped me learn how to use questions through the presentation effectively in order to engage their web audience. I found the technique to be so successful that I have retained and used the questions (in think-pair-share style) as I present our work (on the energetics of proteins) at department seminars.

As a consequence, when I was asked to participate in the ACS Webinar, I was initially not phased by the opportunity. That is, until I learned that the audience would include nearly 400 participants. Fortunately, the ACS staff was similarly awesome. They provided all the necessary infrastructure and great user support. All I had to do was put my slides together just like I do for any other seminar. The inclusion of my industrial collaborator, Stephen Quirk, framed my otherwise academic discussion into one that was more accessible for a broader (viz. industrial) audience. Plus he did all the hard work of selecting the questions for me to answer during the Q and A. All-in-all my total time investment was probably less than four hours. Moreover, we reached a large audience and one that I probably would not have "seen" otherwise. That's a high benefit to cost ratio which I consider a big win.

If you missed my Webinar on "Digitally Pulling Proteins: Molecular Dynamics Simulations," you might still be able to hear it at http://acswebinars.org/digital-proteins. At present, it's available only for view by ACS members.

Item 2: On Celebrating Oral Exams (A random walk through how I run my lab)

Doctoral programs around the country tend to have varying requirements. Invariably, they have some kind of oral exam (early in the program) to establish the candidate's proficiency to continue on to write her or his dissertation. Later, the doctoral candidate completes her or his research and thesis. Whether or not she or he "defends" it with yet another oral presentation, it marks the second major and final stage before earning the doctorate. These two critical transitions can be treated as weed-out mechanisms or as teachable moments. I prefer the latter perspective, and I therefore devote a lot of time to help my students flesh out their ideas and practice their presentations. In the end, it's still them being tested so I have no qualms with helping them be better prepared. It's a training program after all!

As with all rituals, I, like most of my colleagues, find a way to include food and drink to mark these successful transitions. Mine has a twist. After successful completions of each, I bring a bottle of bubbly. I offer a domestic sparkling wine for the candidacy exam, and real champagne after the Ph.D. defense. That is, the real bubbles are reserved for the authentic confirmation of the degree… And I'm happy to report that we celebrated my 10th such doctorate just a few weeks ago!

This continues my random walk through how I run my lab. Look for other such posts using the "RandomWalks" tab. The previous item on a different set of rituals (annual lab outings) can be found here.

A random walk through how I run my lab: Item 1 on Annual Events

Academics often scoff at business types for all the seemingly fluffy stuff they do that we don't have time for. Chief among these might be group-bonding or group-building exercises that are meant to teach people how to collaborate and be flexible in the roles that they play. Yet we academics do undertake all sorts or socializing activities, and most of them aren't geeky at all. Invariably, we celebrate annual holiday parties. (These are meant to be nondenominational and inclusive, but the timing of them in mid to late December obviously coincides better with some traditions than others.) My department arranges biannual lunch-time picnics, and attempts to schedule an annual student verses the faculty soccer friendly. (To make the latter fair, some students are recruited to the faculty side.) I hear that Virginia Tech's chemistry department has a student verses faculty cooking competition. Cookies before seminars, and larger buffets around bigger functions also serve to socialize us. Evidently food serves as an aggregating catalyst almost as good as a chemistry seminar. This may not be so surprising when you realize how varied chemistry is across any given department. Equally evident is the fact that collaboration is just as important for us as it is in industry. The difference is that we don't have mad money to go to ropes courses or off-campus retreats...

Nevertheless, most research groups have some kind of annual ritual. Mine is an all-out group bash staged in the club room of my condo from 4:00PM to past midnight. I try to schedule it around the summer so that the pool is literally in play. I also avoid the holiday season during which everyone is overly saturated with parties as it is. (As we face Thanksgiving+Hanukkah, this year's compressed holiday period seems all the more daunting.) Families are also encouraged to attend. and I supply all the food and drink. It's the least that I can do to give back to my group by insisting that they simply come as themselves bringing only what they need to wear for the pool and such. It's a low key event, and brings the group together. It's followed up by other low-key interactions such as our weekly group brown bag lunch. Together this helps create what I hope is an accommodating group culture for all my students, and one in which they can readily learn with each other and me. I like to think that this will make them better leaders and team members in whatever position their career path will take. That's a lot to expect from an annual group party... Or is it?

Happy Thanksgiving and Hag Someach!

Collaboration in Art and Science

This past weekend, I visited the Dalí exhibition at the Museum of the Reina Sofía in Madrid. Dalí was much more prolific than I had realized (thus my walk through the galleries took twice as long as I had anticipated) and he was a (very disturbed) genius. But the real surprise was how much his trajectory had crossed other great artists in his and in distant fields. For example, he worked with Hitchcock on Spellbound. He worked with Luis Buñuel on a number of his movies, and with Disney on a pair of animated shorts. He is also well known for his ups and downs with his fellow surrealists and his willingness to monetize his craft through so-called Avida Dollars. It's amazing that art which appears to be so individualized is evidently quite collaborative.

In similar fashion, the progress of science is extremely collaborative. One often thinks of the great physicists acting alone while laying down the foundation for quantum mechanics, but it was the Copenhagen interpretation (born from collaboration) and presented at Solvay in 1927 that truly cemented the foundation. In today's world, scientists, great and small, necessarily collaborate. That's why I'm here in Madrid in the first place. I'm working with complex dynamicists at the Politéchnica, a mathematical chemist at the Autónoma, and a mathematical physicist at Loughborough. Together, we're trying to make sense of the structure of the multi-dimensional surface that separates reactants from products. It turns out that this is, by now, fairly well understood when the number of atoms can be counted on one hand regardless of how many fingers you actually have. The trouble is that when you put molecules in a liquid (or some other complex media), it's a bit more difficult to keep track of all of them. So that's where working in a group of people with different talents and expertise comes in useful. And, like Dalí, we need to eat, so we'll take any dollars (or euros) that will allow us to advance our science!