It’s not enough to just publish a great scientific paper.
Somebody else has to think it’s great too and include the work in the references at the end of their paper, the citations. The more citations a paper gets, presumably the more important and influential it is. That’s how science works — you know, the whole standing-on-the-shoulders-of-giants thing.
So it always comes as a chest swelling affirmation for Dukies when we read all those Duke names on the annual list of Most Cited Scientists, compiled by the folks at Clarivate.
This year is another great haul for our thought-leaders. Duke has 30 scientists among the nearly 7,000 authors on the global list, meaning their work is among the top 1 percent of citations by scientific field and year, according to Clarivate’s Web of Science citation index.
As befits Duke’s culture of mixing and matching the sciences in bold new ways, most of the highly cited are from “cross-field” work.
Duke’s Most Cited Are:
Biology and Biochemistry
Charles A. Gersbach
Robert J. Lefkowitz
Clinical Medicine
Scott Antonia
Christopher Bull Granger
Pamela S. Douglas
Adrian F. Hernandez
Manesh R. Patel
Eric D. Peterson
Cross-Field
Chris Beyrer
Stefano Curtarolo
Renate Houts
Tony Jun Huang
Ru-Rong Ji
Jie Liu
Jason Locasale
Edward A. Miao
David B. Mitzi
Christopher B. Newgard
John F. Rawls
Drew T. Shindell
Pratiksha I. Thakore
Mark R. Wiesner
Microbiology
Barton F. Haynes
Neuroscience and Behavior
Quinn T. Ostrom
Pharmacology and Toxicology
Evan D. Kharasch
Plant and Animal Science
Xinnian Dong
Sheng Yang He
Psychiatry and Psychology
Avshalom Caspi
William E. Copeland
E. Jane Costello
Terrie E. Moffitt
Social Sciences
Michael J. Pencina
John W. Williams
Congratulations, one and all! You’ve done us proud again.
It’s May! Time for our 2022 Duke graduates to endure Pomp and Circumstance on repeat, shed a tear, and then take wing. Always bittersweet for those of us who work with students.
This year, the Duke Research Blog celebrates the graduation of three outstanding student-bloggers. This class produced some real gems and we will be greatly diminished by their commencement.
Most memorably, Anna took us along when she spent the summer of 2019 at an archaeology dig in Italy.
Her other topics were a liberal arts education in themselves: she wrote about invisible malaria, climate change, dance, drinking water standards, snow leopards, muscular dystrophy, cybercrime, autism and some fascinating classmates. This year, as she readied for her career, she wrote a three-part series about blockchain and bitcoins.
After graduating with a psychology major, an econ minor and an innovation and entrepreneurship certificate, Anna will be moving to Atlanta to work as an associate consultant at Bain and Company. She plans to continue learning about the web3 space in her “free time” and hopes to find an outlet to continue writing about cryptocurrency as well.
Cydney Livingston, the pride of Anson County, NC, joined us as a sophomore and proceeded to shoot out the lights with 31 career posts.
Cydney Livingston
Cydney’s biggest hit, by far, was her first-person account of trying to continue with college after the pandemic shut down Spring Term, 2020. “Wednesdays, My New Favorite Day,” appealed to Duke alumni, family and friends everywhere who were wondering what the heck was going on in Durham. Short answer: It was weird.
She was integral to our (mostly virtual) coverage of the COVID crisis, and helped the campus keep up with some of the larger questions the emerging virus presented, including social inequity and vaccine hesitancy. She also profiled some grad students, sharing a look inside their worlds from a student’s perspective. And in between, Cydney saw paleontologist Richard Leakey in one of his last public appearances and wrote about space junk, cervixes, lead poisoning, dog smarts, visual perception and North Carolina’s pungent pork industry.
Cydney is graduating with a BS in Biology and an AB II in History and is moving to Boston in the fall to begin work as an analyst with ClearView Healthcare Partners. But she is leaving open the possibility of a return to academia in history of science, technology and medicine, or science and technology studies. “I’m excited to spend a few years working and reflecting on my time at Duke and what lies ahead in my life journey.”
Peak achievement in the sciences isn’t measured by stopwatches or goals scored, it goes by citations – the number of times other scientists have referenced your findings in their own academic papers. A high number of citations is an indication that a particular work was influential in moving the field forward.
Nobel laureate Bob Lefkowitz made the list in two categories this year.
And the peak of this peak is the annual “Highly Cited Researchers” list produced each year by the folks at Clarivate, who run the Institute for Scientific Information. The names on this list are drawn from publications that rank in the top 1% by citations for field and publication year in the Web of Science™ citation index – the most-cited of the cited.
Duke has 38 names on the highly cited list this year — including Bob Lefkowitz twice because he’s just that good — and two colleagues at the Duke NUS Medical School in Singapore. In all, the 2021 list includes 6,602 researchers from more than 70 countries.
The ISI says that US scientists are a little less than 40 percent of the highly cited list this year – and dropping. Chinese researchers are gaining, having nearly doubled their presence on the roster in the last four years.
“The headline story is one of sizeable gains for Mainland China and a decline for the United States, particularly when you look at the trends over the last four years,” said a statement from David Pendlebury, Senior Citation Analyst at the Institute for Scientific Information. “(This reflects) a transformational rebalancing of scientific and scholarly contributions at the top level through the globalization of the research enterprise.”
Without further ado, let’s see who our champions are!
The discovery of a signaling pathway in the brain that could make mice into ‘superlearners’ understandably touched off a lot of excitement a few years back.
But new work led by Duke neurologist and neuroscientist Nicole Calakos MD PhD suggests there’s more to the story of the superlearner chemical pathway than anybody realized.
A genetically-enhanced ‘smart mouse’ doing some important work. (Boston University)
In a study led by postdoctoral researchers Ashley Helseth and Ricardo Hernandez-Martinez, the Calakos lab developed a new tool to visualize activity of this Integrated Stress Response (ISR) signaling pathway because it contributes to synaptic plasticity – the brain’s ability to rewire circuits – as well as to learning and memory.
What they didn’t expect to see is that a population of cells called cholinergic interneurons, which comprise only 1 or 2 percent of the whole basal ganglia structure, seem to have the ISR pathway working all the time. The basal ganglia, which is the focus of much of Calakos’ work, plays a role in Parkinson’s and Huntington’s diseases, Tourette’s syndrome, obsessive compulsive disorder and more.
Nicole Calakos, the Lincoln Financial Group distinguished professor of Neurobiology and Neurology. (Alex Boerner)
“This totally changes how you think about the pathway,” Calakos said. “Everybody thought this pathway used an on-demand response type of mechanism, but what if some cells needed it for their everyday activities?”
To answer this, they blocked the ISR in just those rare interneurons in mice and it actually reproduced the enhanced performance on learned tasks that the earlier studies had shown when the pathway was blocked universally throughout the brain. This finding focuses attention on this select subset of brain cells, the cholinergic interneurons that release the chemical signal acetylcholine, as being responsible for at least some of the ‘superlearner’ behavior.
Since the integrated stress response pathway and its potential to enhance learning and memory was identified, drugs for dementia and traumatic brain injury are being designed to manipulate it and help the brain recover. But there may be more to the story than anyone realized, Calakos said.
“Our results show that the ISR plays a major role in acetylcholine-releasing cells, and our current best dementia drugs boost acetylcholine,” she said.
With their new tool, SPOTlight, the team were able to highlight the presence of cholinergic interneurons (red) which are only 1 to 2 percent of the cell population in the ganglia. (Helseth et al)
Acetylcholine, the chemical that these rare cholinergic interneurons use to signal in the brain, is well known for its powerful effects on influencing brain states for attention and learning. This finding suggests that at least some of the ‘superlearner’ properties of inhibiting the ISR occur by influencing brain state, rather than acting directly in the cells that are being rewired during learning.
In addition to the full research article, Science published on April 23 an article summary by Helseth and Calakos and a perspective piece by a pair of University of Minnesota neuroscientists highlighting the finding’s importance.
More work is required to sort out what ISR is and is not doing, but it’s possible that these new findings can help to develop “more precise, more nuanced Alzheimer’s drugs,” Calakos said.
Five of the ten Duke women included in the most highly-cited list this year. Their scholarly publications are viewed as important and influential by their peers. (Clockwise from upper left: Costello, Curtis, Dawson, Bernhardt, Moffitt)
Thirty-seven Duke faculty were named to the list this year, based on the number of highly cited papers they produced over an 11-year period from January 2009 to December 2019. Citation rate, as tracked by Clarivate’s Web of Science, is an approximate measure of a study’s influence and importance.
Barton Haynes
Two Duke researchers appear in two categories: Human Vaccine Institute Director Barton Haynes, and Michael Pencina, vice dean of data science and information technology in the School of Medicine.
And two of the Duke names listed are new faculty, recruited as part of the Science & Technology initiative: Edward Miao in Immunology and Sheng Yang He in Biology.
Michael Pencina
This year, 6,127 researchers from 60 countries are being recognized by the listing. The United States still dominates, with 41 percent of the names on the list, but China continues to grow its influence, with 12 percent of the names.
Clinical Medicine:
Robert M. Califf, Lesley H. Curtis, Pamela S. Douglas, Christopher Bull Granger, Adrian F. Hernandez, L. Kristen Newby, Erik Magnus Ohman, Manesh R. Patel, Michael J. Pencina, Eric D. Peterson.
Environment and Ecology:
Emily S. Bernhardt, Stuart L. Pimm, Mark R. Weisner.
Geosciences:
Drew T. Shindell
Immunology:
Barton F. Haynes, Edward A. Miao
Microbiology:
Barton F. Haynes
Plant and Animal Science:
Sheng Yang He
Psychiatry and Psychology:
Avshalom Caspi, E. Jane Costello, Renate M. Houts, Terrie E. Moffitt
Social Sciences:
Michael J. Pencina
Cross-Field:
Dan Ariely, Geraldine Dawson, Xinnian Dong, Charles A. Gersbach, Ru-Rong Ji, Robert J. Lefkowitz, Sarah H. Lisanby, Jie Liu, Jason W. Locasale, David B. Mitzi, Christopher B. Newgard, Ram Oren, David R. Smith, Avner Vengosh.
Most of Physics Professor Haiyan Gao’s students see their doctoral dissertations posted on her lab’s web site very soon after they have been awarded their Ph.Ds.
But Yang Zhang, Ph.D. 2018, had to wait two years, because his thesis work had a very good chance of being accepted by a major journal. And this week, it has been published in the journal Science.
What Zhang did was to create the world’s most precise value for a subatomic nuclear particle called a neutral pion. It’s a quark and an antiquark comprising a meson. The neutral pion (also known as p0) is the lightest of the mesons, but a player in the strong attractive force that holds the atom’s nucleus together.
Haiyan Gao (left) with newly-minted physics Ph.D. Yang Zhang in 2018. (Photo courtesy of Min Huang, Ph.D. ’16)
And that, in turn, makes it a part of the puzzle Gao and her students have been trying to solve for many years. The prevailing theory about the strong force is called quantum chromodynamics (QCD), and it’s been probed for years by high-energy physics. But Gao, Zhang and their collaborators are trying to study QCD under more normal energy states, a notoriously difficult problem.
Yang Zhang spent six years analyzing and writing up the data from a Primakoff (PrimEx-II) experiment in Hall B at Thomas Jefferson National Accelerator Facility (Jefferson Lab) in Newport News, VA. His work was done on equipment supported by both the National Science Foundation and the Department of Energy.
This is the quark structure of the positive pion – an up quark and an anti-down quark. The strong force is from gluons, represented as the wavy lines (Arpad Horvath via Wikimedia Commons)
In a Primakoff experiment, a photon beam is directed on a nuclear target, producing neutral pions. In both the PrimEx-I and PrimEx-II experiments at Jefferson Lab, the two photons from the decay of a neutral pionwere subsequently detected in an electromagnetic calorimeter. From that, Zhang extracted the pion’s ‘radiative decay width.’ That decay width is a handy thing to have, because it is directly related to the pion’s life expectancy, and QCD has a direct prediction for it.
Zhang’s hard-won answer: The neutral pion has a radiative decay width of 7.8 electron-volts, give or take. That makes it an important piece of the dauntingly huge puzzle about QCD. Gao and her colleagues will continue to ask the fundamental questions about nature, at the finest but perhaps most profound scale imaginable.
The PrimEx-I and PrimEx-II collaborations were led by Prof. Ashot Gasparian from North Carolina A&T State University. Gao and Zhang joined the collaboration in 2011.
“Precision Measurement of the Neutral Pion Lifetime,” appears in Science May 1. Dr. Yang Zhang is now a quantitative researcher at JPMorgan Chase & Co.
The proton, that little positively-charged nugget inside
an atom, is fractions of a quadrillionth of a meter smaller than anyone thought,
according to new research appearing Nov. 7 in Nature.
Haiyan Gao of Duke Physics
In work they hope solves the contentious “proton radius puzzle” that has been roiling some corners of physics in the last decade, a team of scientists including Duke physicist Haiyan Gao have addressed the question of the proton’s radius in a new way and discovered that it is 0.831 femtometers across, which is about 4 percent smaller than the best previous measurement using electrons from accelerators. (Read the paper!)
A single femtometer is 0.000000000000039370 inches
imperial, if that helps, or think of it as a millionth part of a billionth part
of a meter. And the new radius is just 80 percent of that.
But this is a big — and very small — deal for
physicists, because any precise calculation of energy levels in an atom will be
affected by this measure of the proton’s size, said Gao, who is the Henry
Newson professor of physics in Trinity College of Arts & Sciences.
Bohr model of Hydrogen. One proton, one electron, as simple as they come.
What the physicists actually measured is the radius of
the proton’s charge distribution, but that’s never a smooth, spherical point,
Gao explained. The proton is made of still smaller bits, called quarks, that
have their own charges and those aren’t evenly distributed. Nor does anything
sit still. So it’s kind of a moving target.
One way to measure a proton’s charge radius is to scatter
an electron beam from the nucleus of an atom of hydrogen, which is made of just
one proton and one electron. But the electron must only perturb the proton very
gently to enable researchers to infer the size of the charge involved in the
interaction. Another approach measures the difference between two atomic
hydrogen energy levels. Past results from these two methods have generally
agreed.
Artist’s conception of a very happy muon by Particle Zoo
But in 2010, an experiment at the Paul Scherrer Institute replaced the electron in a hydrogen atom with a muon, a much heavier and shorter-lived member of the electron’s particle family. The muon is still negatively charged like an electron, but it’s about 200 times heavier, so it can orbit much closer to the proton. Measuring the difference between muonic hydrogen energy levels, these physicists obtained a proton charge radius that is highly precise, but much smaller than the previously accepted value. And this started the dispute they’ve dubbed the “proton charge radius puzzle.”
To resolve the puzzle, Gao and her collaborators set out
to do a completely new type of electron scattering experiment with a number of
innovations. And they looked at electron scattering from both the proton and
the electron of the hydrogen atom at the same time. They also managed to get
the beam of electrons scattered at near zero degrees, meaning it came almost
straight forward, which enabled the electron beam to “feel” the proton’s charge
response more precisely.
Voila, a 4-percent-smaller proton. “But actually, it’s
much more complicated,” Gao said, in a major understatement.
The work was done at the Department of Energy’s Thomas
Jefferson National Accelerator Facility in Newport News, Virginia, using new
equipment supported by both the National Science Foundation and the Department
of Energy, and some parts that were purpose-built for this experiment. “To
solve the argument, we needed a new approach,” Gao said.
Gao said she has been interested in this question for nearly
20 years, ever since she became aware of two different values for the proton’s
charge radius, both from electron scattering experiments. “Each one claimed about 1 percent
uncertainty, but they disagreed by several percent,” she said.
And as always in modern physics, had the answer not
worked out so neatly, it might have called into question parts of the Standard
Model of particle physics. But alas, not this time.
“This is particularly important for a number of reasons,”
Gao said. The proton is a fundamental building block of visible matter, and the
energy level of hydrogen is a basic unit of measure that all physicists rely
on.
The new measure may also help advance new insights into
quantum chromodynamics (QCD), the theory of strong interaction in quarks and
gluons, Gao said. “We really don’t understand how QCD works.”
“This is a very, very big deal,” she said. “The field is
very excited about it. And I should add that this experiment would not have
been so successful without the heroic contributions from our highly talented
and hardworking graduate students and postdocs from Duke.”
This work was funded in part by the U. S. National Science Foundation (NSF MRI PHY-1229153) and by the U.S. Department of Energy (Contract No. DE-FG02-03ER41231), including contract No. DE-AC05-06OR23177 under which Jefferson Science Associates, LLC operates Thomas Jefferson National Accelerator Facility.
CITATION: “A Small Proton Charge Radius from An Electron-Proton Scattering Experiment,” W. Xiong, A. Gasparian, H. Gao, et al. Nature, Nov. 7, 2019. DOI: 10.1038/s41586-019-1721-2 (ONLINE)
Just about every day, there’s a new headline about this or
that factor possibly contributing to Alzheimer’s Disease. Is it genetics,
lifestyle, diet, chemical exposures, something else?
The sophisticated answer is that it’s probably ALL of those things working together in a very complicated formula, says Alexander Kulminski, an associate research professor in the Social Science Research Institute. And it’s time to study it that way, he and his colleague, Caleb Finch at the Andrus Gerontology Center at the University of Southern California, argue in a recent paper that appears in the journal Alzheimer’s and Dementia, published by the Alzheimer’s Association.
Positron Emission Tomography scan of a brain affected by cognitive declines . (NIH)
“Life is not simple,” Kulminski says. “We need to combine
different factors.”
“We propose the ‘AD Exposome’ to address major gaps in
understanding environmental contributions to the genetic and non-genetic risk
of AD and related dementias,” they write in their paper. “A systems approach is
needed to understand the multiple brain-body interactions during
neurodegenerative aging.”
The analysis would focus on three domains, Kulminski says:
macro-level external factors like rural v. urban, pollutant exposures,
socio-economcs; individual external factors like diet and infections; and internal
factors like individual microbiomes, fat deposits, and hormones.
That’s a lot of data, often in disparate, broadly scattered
studies. But Kulminski, who came to Duke as a physicist and mathematician, is
confident modern statistics and computers could start to pull it together to
make a more coherent picture. “Twenty years ago, we couldn’t share. Now the way
forward is consortia,” Kulminski said.
The vision they outline in their paper would bring together
longitudinal population data with genome-wide association studies,
environment-wide association studies and anything else that would help the
Alzheimer’s research community flesh out this picture.
And then, ideally, the insights of such research
would lead to ways to “prevent, rather than cure” the cognitive declines of the
disease, Kulminsky says. Which just
happens to be the NIH’s goal for 2025.
Science
is increasingly asking artificial intelligence machines to help us search and interpret
huge collections of data, and it’s making a difference.
But unfortunately, polymer chemistry — the study of large, complex molecules — has been hampered in this effort because it lacks a crisp, coherent language to describe molecules that are not tidy and orderly.
Think nylon. Teflon. Silicone. Polyester. These and other polymers are what the chemists call “stochastic,” they’re assembled from predictable building blocks and follow a finite set of attachment rules, but can be very different in the details from one strand to the next, even within the same polymer formulation.
Plastics, love ’em or hate ’em, they’re here to stay. Foto: Mathias Cramer/temporealfoto.com
Chemistry’s
old stick and ball models and shorthand chemical notations aren’t adequate for a
long molecule that can best be described as a series of probabilities that one
kind of piece might be in a given spot, or not.
Polymer chemists searching for new materials for medical treatments or plastics that won’t become an environmental burden have been somewhat hampered by using a written language that looks like long strings of consonants, equal signs, brackets, carets and parentheses. It’s also somewhat equivocal, so the polymer Nylon-6-6 ends up written like this:
{<C(=O)CCCCC(=O)<,>NCCCCCCN>}
Or this,
{<C(=O)CCCCC(=O)NCCCCCCN>}
And when we get to something called ‘concatenation
syntax,’ matters only get worse.
Stephen Craig, the William T. Miller Professor of Chemistry, has been a polymer chemist for almost two decades and he says the notation language above has some utility for polymers. But Craig, who now heads the National Science Foundation’s Center for the Chemistry of Molecularly Optimized Networks (MONET), and his MONET colleagues thought they could do better.
Stephen Craig
“Once you have that insight about how a polymer is grown,
you need to define some symbols that say there’s a probability of this kind of
structure occurring here, or some other structure occurring at that spot,”
Craig says. “And then it’s reducing that to practice and sort of defining a set
of symbols.”
Now he and his MONET colleagues at MIT and Northwestern University have done just that, resulting in a new language – BigSMILES – that’s an adaptation of the existing language called SMILES (simplified molecular-input line-entry system). They they think it can reduce this hugely combinatorial problem of describing polymers down to something even a dumb computer can understand.
And that, Craig says, should enable computers to do all the stuff they’re good at – searching huge datasets for patterns and finding needles in haystacks.
The initial heavy lifting was done by MONET members Prof. Brad Olsen and his co-worker Tzyy-Shyang Lin at MIT who conceived of the idea and developed the set of symbols and the syntax together. Now polymers and their constituent building blocks and variety of linkages might be described like this:
Examples of bigSMILES symbols from the recent paper
It’s
certainly not the best reading material for us and it would be terribly difficult
to read aloud, but it becomes child’s play for a computer.
Members
of MONET spent a couple of weeks trying to stump the new language with the
weirdest polymers they could imagine, which turned up the need for a few more
parts to the ‘alphabet.’ But by and large, it holds up, Craig says. They also threw
a huge database of polymers at it and it translated them with ease.
“One of the things I’m excited about
is how the data entry might eventually be tied directly to the synthetic
methods used to make a particular polymer,” Craig says. “There’s an opportunity
to actually capture and process more information about the molecules than is
typically available from standard characterizations. If that can be done,
it will enable all sorts of discoveries.”
BigSMILES was introduced to the
polymer community by an article in ACS Central Science
last week, and the MONET team is eager to see the response.
“Can other people use it and does it work for
everything?” Craig asks. “Because polymer structure space is effectively
infinite.” Which is just the kind of thing you need Big Data and machine
learning to address.
“This is an area where the
intersection of chemistry and data science can have a huge impact,” Craig says.
The technical-sounding category of “light-driven
charge-transfer reactions,” becomes more familiar to non-physicists when you just
call it photosynthesis or solar electricity.
When a molecule (in a leaf or solar cell) is hit by an
energetic photon of light, it first absorbs the little meteor’s energy, generating
what chemists call an excited state. This excited state then almost immediately
(like trillionths of a second) shuttles an electron away to a charge acceptor
to lower its energy. That transference of charge is what drives plant life and
photovoltaic current.
A 20 Megawatt solar farm ( Aerial Innovations via wikimedia commons)
The energy of the excited state plays an important role in
determining solar energy conversion efficiency. That is, the more of that
photon’s energy that can be retained in the charge-separated state, the better.
For most solar-electric devices, the excited state rapidly loses energy,
resulting in less efficient devices.
But what if there were a way to create even more energetic
excited states from that incoming photon?
Using a very efficient photosynthesizing bacterium as their inspiration,
a team of Duke chemists that included graduate students Nick Polizzi and Ting
Jiang, and faculty members David Beratan and Michael Therien, synthesized a
“supermolecule” to help address this question.
“Nick and Ting discovered a really cool trick about electron
transfer that we might be able to adapt to improving solar cells,” said Michael
Therien, the William R. Kenan, Jr. Professor of Chemistry. “Biology figured
this out eons ago,” he said.
“When molecules absorb light, they have more energy,” Therien said. “One of the things that these molecular excited states do is that they move charge. Generally speaking, most solar energy conversion structures that chemists design feature molecules that push electron density in the direction they want charge to move when a photon is absorbed. The solar-fueled microbe, Rhodobacter sphaeroides, however, does the opposite. What Nick and Ting demonstrated is that this could also be a winning strategy for solar cells.”
Ting Jiang
Nick Polizzi
The chemists devised a clever synthetic molecule that shows the advantages of an excited state that pushes electron density in the direction opposite to where charge flows. In effect, this allows more of the energy harvested from a photon to be used in a solar cell.
“Nick and Ting’s work shows that there are huge advantages
to pushing electron density in the exact opposite direction where you want
charge to flow,” Therien said in his top-floor office of the French Family
Science Center. “The biggest advantage of an excited state that pushes charge the
wrong way is it stops a really critical pathway for excited state relaxation.”
“So, in many ways it’s a Rube Goldberg Like conception,”
Therien said. “It is a design strategy that’s been maybe staring us in the face
for several years, but no one’s connected the dots like Nick and Ting have
here.”
In a July 2
commentary for the Proceedings of the National Academy of Sciences, Bowling
Green State University chemist and photoscientist Malcom D.E. Forbes calls this
work “a great leap forward,” and says it “should be regarded as one of the most
beautiful experiments in physical chemistry in the 21st century.”
Here’s a schematic from the paper. (Image by Nick Polizzi)
CITATION: “Engineering Opposite Electronic Polarization of
Singlet and Triplet States Increases the Yield of High-Energy Photoproducts,”
Nicholas Polizzi, Ting Jiang, David Beratan, Michael Therien. Proceedings of
the National Academy of Sciences, June 10, 2019. DOI: 10.1073/pnas.1901752116
Online: https://www.pnas.org/content/early/2019/07/01/1908872116
