Lippert’s team develops synthetic organic compounds that glow in reaction to certain conditions. He led his lab in developing a new technology that uses photoswitch molecules to craft 3-D light structures — not holograms — that are viewable from 360 degrees. An economical method for shaping light into an infinite number of volumetric objects, the technology will be useful in a variety of fields, from biomedical imaging, education and engineering, to TV, movies, video games and more.
For biomedical imaging, Lippert says the nearest-term application of the technique might be in high-volume pre-clinical animal imaging, but eventually the technique could be applied to provide low-cost internal imaging in the developing world, or less costly imaging in the developed world.
The Daily Planet segment aired Dec. 12, 2017.
Lippert’s lab includes four doctoral students and five undergraduates who assist in his research. He recently received a prestigious National Science Foundation Career Award, expected to total $611,000 over five years, to fund his research into alternative internal imaging techniques.
NSF Career Awards are given to tenure-track faculty members who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research in American colleges and universities.
Lippert joined SMU in 2012. He was previously a postdoctoral researcher at the University of California, Berkeley, and earned his Ph.D. at the University of Pennsylvania, and Bachelor of Science at the California Institute of Technology.
Lippert’s team develops synthetic organic compounds that glow in reaction to certain conditions. He led his lab in developing a new technology that uses photoswitch molecules to craft 3-D light structures — not holograms — that are viewable from 360 degrees. The economical method for shaping light into an infinite number of volumetric objects would be useful in a variety of fields, from biomedical imaging, education and engineering, to TV, movies, video games and more.
For biomedical imaging, Lippert says the nearest-term application of the technique might be in high-volume pre-clinical animal imaging, but eventually the technique could be applied to provide low-cost internal imaging in the developing world, or less costly imaging in the developed world.
Lippert’s lab includes four doctoral students and five undergraduates who assist in his research. He recently received a prestigious National Science Foundation Career Award, expected to total $611,000 over five years, to fund his research into alternative internal imaging techniques.
NSF Career Awards are given to tenure-track faculty members who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research in American colleges and universities.
Lippert joined SMU in 2012. He was previously a postdoctoral researcher at the University of California, Berkeley, and earned his Ph.D. at the University of Pennsylvania, and Bachelor of Science at the California Institute of Technology.
By Joel F. Hooper
Cosmos
Those of us who grew up watching science fiction movies and TV shows imagined our futures to be filled with marvellous gadgets, but we’ve sometimes been disappointed when science fails to deliver. We can’t take a weekend trip to Mars yet, and we’re still waiting for hoverboards that actually hover.
But in the case of 3-D image projection, the technology used by R2D2 in Star Wars is making its way into reality. Using advances in fluorescent molecules that can be switched on by UV light, scientists at Southern Methodist University in Dallas have created a method for producing images and animations by structuring light in 3-dimentions.
The technology uses a solution of fluorescent molecules called rhodamines, which have the potential to emit visible light when they are excited by a light beam of the right wavelength. But these molecules are usually in an inactive state, and must be “switched on” by UV light before they can become emitters. When a UV light or visible light beam alone shines through the solution, the rhodamines to not emit light. But where these two beams intersect, the emitting molecules are both switched on and excited, and can produce a small glowing 3D pixel, known as a voxel.
When a number of voxels are produced at once, using two projectors positioned at 90° to a flask containing a solution of the fluorescent molecules, a 3D image is produced.
“Our idea was to use chemistry and special photoswitch molecules to make a 3D display that delivers a 360-degree view,” says Alexander Lippert, lead author of the study. “It’s not a hologram, it’s really three-dimensionally structured light.”
Photoswitch chemistry allows construction of light shapes into structures that have volume and are viewable from 360 degrees, making them useful for biomedical imaging, teaching, engineering, TV, movies, video games and more
A scientist’s dream of 3-D projections like those he saw years ago in a Star Wars movie has led to new technology for making animated 3-D table-top objects by structuring light.
The new technology uses photoswitch molecules to bring to life 3-D light structures that are viewable from 360 degrees, says chemist Alexander Lippert, Southern Methodist University, Dallas, who led the research.
The economical method for shaping light into an infinite number of volumetric objects would be useful in a variety of fields, from biomedical imaging, education and engineering, to TV, movies, video games and more.
“Our idea was to use chemistry and special photoswitch molecules to make a 3-D display that delivers a 360-degree view,” said Lippert, an assistant professor in the SMU Department of Chemistry. “It’s not a hologram, it’s really three-dimensionally structured light.”
Key to the technology is a molecule that switches between non-fluorescent and fluorescent in reaction to the presence or absence of ultraviolet light.
The new technology is not a hologram, and differs from 3-D movies or 3-D computer design. Those are flat displays that use binocular disparity or linear perspective to make objects appear three-dimensional when in fact they only have height and width and lack a true volume profile.
“When you see a 3-D movie, for example, it’s tricking your brain to see 3-D by presenting two different images to each eye,” Lippert said. “Our display is not tricking your brain — we’ve used chemistry to structure light in three actual dimensions, so no tricks, just a real three-dimensional light structure. We call it a 3-D digital light photoactivatable dye display, or 3-D Light Pad for short, and it’s much more like what we see in real life.”
At the heart of the SMU 3-D Light Pad technology is a “photoswitch” molecule, which can switch from colorless to fluorescent when shined with a beam of ultraviolet light.
The researchers discovered a chemical innovation for tuning the photoswitch molecule’s rate of thermal fading — its on-off switch — by adding to it the chemical amine base triethylamine.
Now the sky is the limit for the new SMU 3-D Light Pad technology, given the many possible uses, said Lippert, an expert in fluorescence and chemiluminescence — using chemistry to explore the interaction between light and matter.
For example, conference calls could feel more like face-to-face meetings with volumetric 3-D images projected onto chairs. Construction and manufacturing projects could benefit from rendering them first in 3-D to observe and discuss real-time spatial information. For the military, uses could include tactical 3-D replications of battlefields on land, in the air, under water or even in space.
Volumetric 3-D could also benefit the medical field.
“With real 3-D results of an MRI, radiologists could more readily recognize abnormalities such as cancer,” Lippert said. “I think it would have a significant impact on human health because an actual 3-D image can deliver more information.”
Unlike 3-D printing, volumetric 3-D structured light is easily animated and altered to accommodate a change in design. Also, multiple people can simultaneously view various sides of volumetric display, conceivably making amusement parks, advertising, 3-D movies and 3-D games more lifelike, visually compelling and entertaining.
Co-authors are Shreya K. Patel, lead author, and Jian Cao, both students in the SMU Department of Chemistry.
Genesis of an idea — cinematic inspiration
The idea to shape light into volumetric animated 3-D objects came from Lippert’s childhood fascination with the movie “Star Wars.” Specifically he was inspired when R2-D2 projects a hologram of Princess Leia. Lippert’s interest continued with the holodeck in “Star Trek: The Next Generation.”
“As a kid I kept trying to think of a way to invent this,” Lippert said. “Then once I got a background in chemistry molecules that interact with light, and an understanding of photoswitches, it finally dawned on me that I could take two beams of light and use chemistry to manipulate the emission of light.”
Key to the new technology was discovering how to turn the chemical photoswitch off and on instantly, and generating light emissions from the intersection of two different light beams in a solution of the photoactivatable dye, he said.
SMU graduate student in chemistry Jian Cao hypothesized the activated photoswitch would turn off quickly by adding the base. He was right.
“The chemical innovation was our discovery that by adding one drop of triethylamine, we could tune the rate of thermal fading so that it instantly goes from a pink solution to a clear solution,” Lippert said. “Without a base, the activation with UV light takes minutes to hours to fade back and turn off, which is a problem if you’re trying to make an image. We wanted the rate of reaction with UV light to be very fast, making it switch on. We also wanted the off-rate to be very fast so the image doesn’t bleed.”
SMU 3-D Light Pad
In choosing among various photoswitch dyes, the researchers settled on N-phenyl spirolactam rhodamines. That particular class of rhodamine dyes was first described in the late 1970s and made use of by Stanford University’s Nobel prize-winning W.E. Moerner.
The dye absorbs light within the visible region, making it appropriate to fluoresce light. Shining it with UV radiation, specifically, triggers a photochemical reaction and forces it to open up and become fluorescent.
Turning off the UV light beam shuts down fluorescence, diminishes light scattering, and makes the reaction reversible — ideal for creating an animated 3-D image that turns on and off.
“Adding triethylamine to switch it off and on quickly was a key chemical discovery that we made,” Lippert said.
To produce a viewable image they still needed a setup to structure the light.
Structuring light in a table-top display
The researchers started with a custom-built, table-top, quartz glass imaging chamber 50 millimeters by 50 millimeters by 50 millimeters to house the photoswitch and to capture light.
Inside they deployed a liquid solvent, dichloromethane, as the matrix in which to dissolve the N-phenyl spirolactam rhodamine, the solid, white crystalline photoswitch dye.
Next they projected patterns into the chamber to structure light in two dimensions. They used an off-the-shelf Digital Light Processing (DLP) projector purchased at Best Buy for beaming visible light.
The DLP projector, which reflects visible light via an array of microscopically tiny mirrors on a semiconductor chip, projected a beam of green light in the shape of a square. For UV light, the researchers shined a series of UV light bars from a specially made 385-nanometer Light-Emitting Diode projector from the opposite side.
Where the light intersected and mixed in the chamber, there was displayed a pattern of two-dimensional squares stacked across the chamber. Optimized filter sets eliminated blue background light and allowed only red light to pass.
To get a static 3-D image, they patterned the light in both directions, with a triangle from the UV and a green triangle from the visible, yielding a pyramid at the intersection, Lippert said.
From there, one of the first animated 3-D images the researchers created was the SMU mascot, Peruna, a racing mustang.
“For Peruna — real-time 3-D animation — SMU undergraduate student Shreya Patel found a way to beam a UV light bar and keep it steady, then project with the green light a movie of the mustang running,” Lippert said.
So long Renaissance
Today’s 3-D images date to the Italian Renaissance and its leading architect and engineer.
“Brunelleschi during his work on the Baptistery of St. John was the first to use the mathematical representation of linear perspective that we now call 3-D. This is how artists used visual tricks to make a 2-D picture look 3-D,” Lippert said. “Parallel lines converge at a vanishing point and give a strong sense of 3-D. It’s a useful trick but it’s striking we’re still using a 500-year-old technique to display 3-D information.”
The SMU 3-D Light Pad technology, patented in 2016, has a number of advantages over contemporary attempts by others to create a volumetric display but that haven’t emerged as commercially viable.
Some of those have been bulky or difficult to align, while others use expensive rare earth metals, or rely on high-powered lasers that are both expensive and somewhat dangerous.
The SMU 3-D Light Pad uses lower light powers, which are not only cheaper but safer. The matrix for the display is also economical, and there are no moving parts to fabricate, maintain or break down.
Lippert and his team fabricated the SMU 3-D Light Pad for under $5,000 through a grant from the SMU University Research Council.
“For a really modest investment we’ve done something that can compete with more expensive $100,000 systems,” Lippert said. “We think we can optimize this and get it down to a couple thousand dollars or even lower.”
Next Gen: SMU 3-D Light Pad 2.0
The resolution quality of a 2-D digital photograph is stated in pixels. The more pixels, the sharper and higher-quality the image. Similarly, 3-D objects are measured in voxels — a pixel but with volume. The current 3-D Light Pad can generate more than 183,000 voxels, and simply scaling the volume size should increase the number of voxels into the millions – equal to the number of mirrors in the DLP micromirror arrays.
For their display, the SMU researchers wanted the highest resolution possible, measured in terms of the minimum spacing between any two of the bars. They achieved 200 microns, which compares favorably to 100 microns for a standard TV display or 200 microns for a projector.
The goal now is to move away from a liquid vat of solvent for the display to a solid cube table display. Optical polymer, for example, would weigh about the same as a TV set. Lippert also toys with the idea of an aerosol display.
The researchers hope to expand from a monochrome red image to true color, based on mixing red, green and blue light. They are working to optimize the optics, graphics engine, lenses, projector technology and photoswitch molecules.
“I think it’s a very fascinating area. Everything we see — all the color we see — arises from the interaction of light with matter,” Lippert said. “The molecules in an object are absorbing a wavelength of light and we see all the rest that’s reflected. So when we see blue, it’s because the object is absorbing all the red light. What’s more, it is actually photoswitch molecules in our eyes that start the process of translating different wavelengths of light into the conscious experience of color. That’s the fundamental chemistry and it builds our entire visual world. Being immersed in chemistry every day — that’s the filter I’m seeing everything through.”
The SMU discovery and new technology, Lippert said, speak to the power of encouraging young children.
“They’re not going to solve all the world’s problems when they’re seven years old,” he said. “But ideas get seeded and if they get nurtured as children grow up they can achieve things we never thought possible.” — Margaret Allen, SMU
NSF Career Awards are given to tenure-track faculty members who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research in American colleges and universities.
Lippert’s team develops synthetic organic compounds that glow in reaction to certain conditions. For example, when injected into a mouse’s tumor, the compounds luminesce in response to the cancer’s pH and oxygen levels. Place that mouse in a sealed dark box with a sensitive CCD camera that can detect low levels of light, and images can be captured of the light emanating from the mouse’s tumor.
“We are developing chemiluminescent imaging agents, which basically amounts to a specialized type of glow-stick chemistry,” Lippert says. “We can use this method to image the insides of animals, kind of like an MRI, but much cheaper and easier to do.”
Lippert says the nearest-term application of the technique might be in high-volume pre-clinical animal imaging, but eventually the technique could be applied to provide low-cost internal imaging in the developing world, or less costly imaging in the developed world.
But first, there are still a few ways the technique can be improved, and that’s where Lippert says the grant will come in handy.
“In preliminary studies, we needed to directly inject the compound into the tumor to see the chemistry in the tumor,” Lippert says. “One thing that’s funded by this grant is intravenous injection capability, where you inject a test subject and let the agent distribute through the body, then activate it in the tumor to see it light up.”
Another challenge the team will use the grant to explore is making a compound that varies by color instead of glow intensity when reacting to cancer cells. This will make it easier to read images, which can sometimes be buried under several layers of tissue, making the intensity of the glow difficult to interpret.
“We’re applying the method to tumors now, but you could use similar designs for other types of tissues,” Lippert says. “The current compound reacts to oxygen levels and pH, which are important in cancer biology, but also present in other types of biology, so it can be more wide-ranging than just looking at cancer.”
“This grant is really critical to our ability to continue the research going forward,” Lippert adds. “This will support the reagents and supplies, student stipends, and strengthen our collaboration with UT Southwestern Medical Center. Having that funding secure for five years is really nice because we can now focus our attention on the actual science instead of writing grants. It’s a huge step forward in our research progress.”
Lippert joined SMU in 2012. He was a postdoctoral researcher at the University of California, Berkeley, from 2009-12, earned his Ph.D. at the University of Pennsylvania in 2008 and earned a Bachelor of Science at the California Institute of Technology in 2003.
The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 “to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense…” NSF is the funding source for approximately 24 percent of all federally supported basic research conducted by America’s colleges and universities. — Kenny Ryan, SMU
Discovery may someday allow farmers to grow crops in climates where they currently won’t grow and allows scientists to make a subtle, targeted mutation to a specific native plant protein
Findings of a new study solve a key mystery about the chemistry of how plants tell time so they can flower and metabolize nutrients.
The process — a subtle chemical event — takes place in the cells of every plant every second of every day.
The new understanding means farmers may someday grow crops under conditions or in climates where they currently can’t grow, said chemist Brian D. Zoltowski, Southern Methodist University, Dallas, who led the study.
“We now understand the chemistry allowing plants to maintain a natural 24-hour rhythm in sync with their environment. This allows us to tune the chemistry, like turning a dimmer switch up or down, to alter the organism’s ability to keep time,” Zoltowski said. “So we can either make the plant’s clock run faster, or make it run slower. By altering these subtle chemical events we might be able to rationally redesign a plant’s photochemistry to allow it to adapt to a new climate.”
Specifically, the researchers figured out the chemical nuts and bolts of how a chemical bond in the protein Zeitlupe forms and breaks in reaction to sunlight, and the rate at which it does so, to understand how proteins in a plant’s cells signal the plant when to bloom, metabolize, store energy and perform other functions.
Zoltowski’s team, with collaborators at the University of Washington and Ohio State University, have made plant strains with specific changes to the way they are able to respond to blue-light.
“With these plants we demonstrate that indeed we can tune how the organisms respond to their environment in an intelligible manner,” Zoltowski said.
Zoltowski and his colleagues made the discovery by mapping the crystal structure of a plant protein whose function is to measure the intensity of sunlight. The protein is able to translate light intensity to a bond formation event that allows the plant to track the time of day and tell the plant when to bloom or metabolize nutrients.
A plant uses visual cues to constantly read every aspect of its environment and retune its physiological functions to adapt accordingly. Some of these cues are monitored by plant proteins that absorb and transmit light signals — called photoreceptors. The research team specifically studied two key photoreceptors, Zeitlupe (Zite-LOO-puh) and FKF-1.
“Plants have a very complex array of photoreceptors absorbing all different wavelengths of light to recognize every aspect of their environment and adapt accordingly,” said Zoltowski, an assistant professor in the SMU Department of Chemistry. “All their cells and tissue types are working in concert with each other.”
Co-author and lead author is Ashutosh Pudasaini, a doctoral graduate from the SMU Department of Chemistry who is now a postdoctoral fellow at the University of Texas Southwestern Medical School, Dallas. Other co-authors are Jae Sung Shim, Young Hun Song and Takato Imaizumi, University of Washington, Seattle; Hua Shi and David E. Somers, Ohio State University; and Takatoshi Kiba, RIKEN Center for Sustainable Resource Science, Japan.
Nighttime is the right time for plants to grow
“If you live in the Midwest, people say you hear the corn growing at night,” said Zoltowski, who grew up in rural Wisconsin.
“During the day, a plant is storing as much energy as it can by absorbing photons of sunlight, so that during the evening it can do all its metabolism and growth and development. So there’s this separation between day and night.”
Plants measure these day and night oscillations as well as seasonal changes. Knowledge already existed of the initial chemistry, biology and physiology of that process.
In addition, Zoltowski and colleagues published in 2013 the discovery that the amino acids in Zeitlupe — working like a dimmer switch — gradually get more active as daytime turns to evening, thereby managing the 24-hour Circadian rhythm. Additionally, they found that FKF-1 is very different from Zeitlupe. FKF-1 switches on with morning light and measures seasonal changes, otherwise called photoperiodism.
But a knowledge gap remained. It was a mystery how the information is integrated by the organism.
“Ultimately that has to be related to some kind of chemical event occurring, some kind of chemical timekeeper,” Zoltowski said. “So by following that trail we figured out how the chemistry works.”
Dark state and light state snapshots
The problem required a two-pronged approach: Solving the structure of the protein to understand how forming and breaking bonds changes how the organism perceives its environment; and solving the chemistry, specifically the crystal structures of the protein’s dark and light states.
That process yielded a snapshot of the protein in the dark state and a snapshot of the protein in the light state, so the researchers could watch changes in protein structure in response to the bond-forming event.
From there, the researchers made mathematical models 1) that explain how the chemistry of the bond breaking and bond forming event, and the rate at which it occurs, should affect the organism; and 2) that design mutations to the protein that affect how it goes from the dark state to the light state to block that process.
Standard techniques yielded the discovery
The team used a few standard techniques. To get at the chemistry, they deployed ultra-violet visible spectroscopy to measure how efficiently proteins absorb light. They followed differences in the absorption spectrum, seeing what wavelengths are absorbed, to track chemical changes between the dark and the light states.
On the structure side, they crystallized the proteins and collected data at synchrotron sources at Cornell University, then mapped out like a puzzle where all the electrons are located in the crystal. From there they could fit and build — amino acid by amino acid — the protein, yielding a three-dimensional image of where every atom in the protein is located.
“This gives us pictures and snapshots of all those discrete events, where then we can look at how the atoms are moving and changing from one to the other,” Zoltowski said. “That allows us to see the bonds forming, the bonds breaking, and how the rest of the protein changes in response to that.”
Why didn’t we think of that?
The question has been an important one in the field, but challenging technical hurdles thwarted solutions, said Zoltowski. The key for his team was persistence and years of experience.
“This is not an easy protein to work with — it’s difficult to get crystals of these proteins. It requires a protein that is stable enough and will interact in a way that it yields a perfectly ordered crystal. So it’s difficult to do the chemistry and the structures. Researchers have struggled with getting adequate amounts of protein to be able to do these types of characterizations,” he said.
Think of it like a diamond, Zoltowski said, which is a perfectly ordered crystal that is just carbon atoms arranged in a specific way.
“Zeitlupe and FKF-1 have thousands of atoms in each protein, and in order to get a crystal, each molecule of the protein needs to arrange itself with the same type of accuracy and precision as carbon atoms in a diamond. Getting that to occur, where they pack nicely together, is non trivial. And some proteins just are really challenging to work with.”
Zoltowski and his colleagues have been fortunate in having years of experience working with these families of proteins, called the Light-oxygen-voltage-sensing domains, or LOV domains, for short.
“So we’ve developed a lot of skills and techniques over the years that can get over some of the technical hurdles,” he said. “So just from gaining experience over time, we’ve gotten better with working with some very difficult proteins. It makes something that is challenging, much more tractable for our lab.”
Does this apply to all LOV proteins in every plant?
Zeitlupe is a German word that means slow motion. The protein was dubbed Zeitlupe because scientists discovered when they found mutations of this protein previously that it made the Circadian clock run slower. It naturally altered the way the organism perceived time.
“We wanted to understand the proteins well enough that we could selectively alter the chemistry, or selectively alter the structure, to create mutations that would be testable in the organism,” Zoltowski said. “We wanted a predictive model that would tell us that these mutations that affect the kinetics — the rate at which this bond breaks — should do ‘X’ in the organism.”
The team’s new discovery results in hybrid plants — something nature already does and has done for millions of years through the process of evolution so that plants adapt to survive.
“We’re not putting anything into the plant or changing its genetics,” Zoltowski said. “We’re making a very subtle, targeted mutation to a specific protein that already is a native plant protein — and one that we’ve shown in this paper has evolved considerably throughout various different agricultural crops to already do this.”
The discovery gives scientists the ability to rationally interpret environmental information affecting a plant in order to introduce mutations, instead of relying on selective breeding to achieve a targeted mutation to generate phenotypes that potentially allow the plant to grow in a different environment.
What’s next?
The research opens a lot of new doors, including new questions about how these proteins are changing their configuration and how other variables, like oxidative stress, couple with the plant’s global sensory networks to also alter proteins and send multiple signals from the environment.
“What we’ve learned is that you need to pay careful attention to specific parts of the protein because they’re modulating activity selectively in different categories of this family,” Zoltowski said. “If we look at the whole family of these proteins, there are key amino acids that are evolutionarily selected, so they evolve specific modulations of this activity for their own independent niche in the environment. One of the take-homes is there are areas in the protein we need to look at to see how the amino acids are now different.”
Besides the NIH grant, the lab operates with $250,000 from the American Chemical Society’s Herman Frasch Foundation for Chemical Research Grants in Agricultural Chemistry. — Margaret Allen
The Dallas Innovates article “SMU Chemists Find New Way to Break Carbon, Hydrogen Bond” notes that the new catalyst for breaking the tough molecular bond between carbon and hydrogen holds the promise of a cleaner, easier and cheaper way to derive products from petroleum.
An assistant professor, Garcia-Bosch is Harold A. Jeskey Endowed Chair in Chemistry.
Chemists at Southern Methodist University in Dallas have found a cheaper, cleaner method to break the stubborn molecular bond between carbon and hydrogen, a development that could lead to better ways to derive products from petroleum.
“Some of the most useful building blocks we have in the world are simple, plentiful hydrocarbons like methane, which we extract from the ground. They can be used as starting materials for complex chemical products such as plastics and pharmaceuticals,” Isaac Garcia-Bosch, Harold A. Jeskey Endowed Chair and assistant professor in the Department of Chemistry at SMU, told Eurekalert.org. “But the first step of the process is very, very difficult — breaking that carbon-hydrogen bond. The stronger the bond, the more difficult it is to oxidize.”
Oxidizing causes the molecule to undergo a reaction that combines with oxygen and breaks the carbon-hydrogen bonds, according to Eurekalert.
SMU chemists have been working on the project in collaboration with a team from the Johns Hopkins University.
According to the report, Garcia-Bosch and chemist Maxime A. Siegler, director of the X-Ray Crystallography facility at the Johns Hopkins University, used copper catalysts in conjunction with hydrogen peroxide to create the carbon-oxygen bonds.
Upon mixing the reactants (copper + ligand + hydrogen peroxide + carbon-hydrogen substrate) the starting colorless solution turns green-blue, indicating that an oxidative process is occurring. (Credit: SMU)
Chemists discover new way to crack the stubborn carbon-hydrogen bond that could allow industry to make petroleum-derived commercial products easier, cheaper and cleaner
A new catalyst for breaking the tough molecular bond between carbon and hydrogen holds the promise of a cleaner, easier and cheaper way to derive products from petroleum, says a researcher at Southern Methodist University, Dallas.
“Some of the most useful building blocks we have in the world are simple, plentiful hydrocarbons like methane, which we extract from the ground. They can be used as starting materials for complex chemical products such as plastics and pharmaceuticals,” said Isaac Garcia-Bosch, Harold A. Jeskey Endowed Chair assistant professor in the Department of Chemistry at SMU. “But the first step of the process is very, very difficult — breaking that carbon-hydrogen bond. The stronger the bond, the more difficult it is to oxidize.”
The chemical industry must break the tenacious bond between carbon and hydrogen molecules to synthesize oxidative products such as methanol and phenols. It’s called oxidizing because it causes the molecule to undergo a reaction in which it combines with oxygen, breaking C-H bonds and forming new carbon-oxygen bonds.
The conventional chemical recipe calls for inefficient and expensive oxidants to break the C-H bond. That process is costly, difficult and leaves behind dirty waste products.
Chemists at SMU, in collaboration with The Johns Hopkins University, have found a cheaper, cleaner way to crack the stubborn C-H bond.
Garcia-Bosch and chemist Maxime A. Siegler, director of the X-ray Crystallography Facility at The Johns Hopkins University, used copper catalysts that in combination with hydrogen peroxide (oxygen source) can convert C-H bonds to C-O bonds.
“This is a very important discovery because it’s the first time it’s been proven that copper can carry out this kind of oxidation outside of nature in an efficient way,” Garcia-Bosch said. “The prep is very simple, so labs anywhere can do it. Copper is relatively cheap compared to other metals such as palladium, gold or silver, and hydrogen peroxide is readily available, relatively cheap and very clean. One of the byproducts of oxidations with hydrogen peroxide (H2O2) is water (H2O), which is the cleanest waste product you could have.”
Additionally, the researchers found the right ligand — a nitrogen-based material that binds to the copper so that the oxidation process can occur with close to perfect efficiency.
It’s important to have the right ligand, the right amount of hydrogen peroxide, and the right metal in order to oxidize these challenging C-H bonds.
“We found that combination,” Garcia-Bosch said.
Chemistry is like a puzzle, where you build new molecules out of other molecules, he said.
In any one molecule there are many C-H bonds. For example in octanes, such as the ones found in gasoline, there’s a carbon chain of eight carbons with multiple C-H bonds with different chemical properties, Garcia-Bosch said, and from the oxidation of each of the C-H bonds, a different product results.
Chemists design catalysts that are capable of breaking and forming bonds in order to build complex chemical structures.
“Catalysts have to be able to select between different C-H bonds and form new carbon-oxygen, carbon-nitrogen or carbon-fluoride bonds, for example,” Garcia-Bosch said. “Biological processes use metals to do this all the time, for example in our bodies when our liver processes a pharmaceutical that we ingest using iron. Minerals such as iron, copper, manganese, calcium and potassium are critical for the natural catalytic process. For example, trees use manganese (photosynthesis) to transform water into the oxygen that we breathe”
First time for using copper for C-H oxidation
In organic chemistry, there aren’t many examples of copper as a catalyst for carbon-hydrogen oxidation. Most examples are based on iron.
“This is the first time in our field that we’ve used copper to do this C-H oxidation in a very efficient way,” Garcia-Bosch said.
“Copper is very versatile in nature,” he said. “With small changes in the environment of copper, you can do very diverse chemistry. That’s why we picked it.”
That environment is the ligand, which gives properties to the copper to spark the chemical reaction when the chemical ingredients are combined in a vial or round bottom flask.
The researchers discovered that these catalysts — copper in the form of a white salt and the ligand as an oil — can oxidize C-H bonds in a very efficient way in combination with hydrogen peroxide, a reduced form of oxygen that nature uses.
“You can find hydrogen peroxide anywhere, even at home in your medicine cabinet. So it’s a mild oxidant,” Garcia-Bosch said. “It’s convenient also, because it’s a liquid, rather than, say, a gas, which might require special storage. You mix everything together in a solvent and it reacts. It’s like making a soup, a recipe, then you analyze the result to see what you get.”
Using a gas chromatography instrument, the Garcia-Bosch and Siegler analyzed the final solution to observe the results of the reaction. That allowed them to quantify the amount of oxidation product that was formed during the reaction.
Next step — targeting a specific C-H bond
“We tested this catalytic system for different substrates and we saw that it’s not very selective,” Garcia-Bosch said. “That’s a problem. So if we have molecules that have many different C-H bonds, then it’s going to oxidize all of them in a non-selective manner. In our lab, we would like to find selective catalysts. That’s the next project.”
Garcia-Bosch holds the Harold A. Jeskey Endowed Chair in Chemistry. The research was funded through The Robert A. Welch Foundation (Grant N-1900).
SMU scientists and their research have a global reach that is frequently noted, beyond peer publications and media mentions.
By Margaret Allen
SMU News & Communications
It was a good year for SMU faculty and student research efforts. Here is a small sampling of public and published acknowledgements during 2015:
Hot topic merits open access
Taylor & Francis, publisher of the online journal Environmental Education Research, lifted its subscription-only requirement to meet demand for an article on how climate change is taught to middle-schoolers in California.
Co-author of the research was Diego Román, assistant professor in the Department of Teaching and Learning, Annette Caldwell Simmons School of Education and Human Development.
Román’s research revealed that California textbooks are teaching sixth graders that climate change is a controversial debate stemming from differing opinions, rather than a scientific conclusion based on rigorous scientific evidence.
Research makes the cover of Biochemistry
Drugs important in the battle against cancer were tested in a virtual lab by SMU biology professors to see how they would behave in the human cell.
A computer-generated composite image of the simulation made the Dec. 15 cover of the journal Biochemistry.
Scientific articles about discoveries from the simulation were also published in the peer review journals Biochemistry and in Pharmacology Research & Perspectives.
The researchers tested the drugs by simulating their interaction in a computer-generated model of one of the cell’s key molecular pumps — the protein P-glycoprotein, or P-gp. Outcomes of interest were then tested in the Wise-Vogel wet lab.
The ongoing research is the work of biochemists John Wise, associate professor, and Pia Vogel, professor and director of the SMU Center for Drug Discovery, Design and Delivery in Dedman College. Assisting them were a team of SMU graduate and undergraduate students.
The researchers developed the model to overcome the problem of relying on traditional static images for the structure of P-gp. The simulation makes it possible for researchers to dock nearly any drug in the protein and see how it behaves, then test those of interest in an actual lab.
To date, the researchers have run millions of compounds through the pump and have discovered some that are promising for development into pharmaceutical drugs to battle cancer.
Strong interest in research on sexual victimization
Teen girls were less likely to report being sexually victimized after learning to assertively resist unwanted sexual overtures and after practicing resistance in a realistic virtual environment, according to three professors from the SMU Department of Psychology.
The finding was reported in Behavior Therapy. The article was one of the psychology journal’s most heavily shared and mentioned articles across social media, blogs and news outlets during 2015, the publisher announced.
The study was the work of Dedman College faculty Lorelei Simpson Rowe, associate professor and Psychology Department graduate program co-director; Ernest Jouriles, professor; and Renee McDonald, SMU associate dean for research and academic affairs.
Consumers assume bigger price equals better quality
Even when competing firms can credibly disclose the positive attributes of their products to buyers, they may not do so.
Instead, they find it more lucrative to “signal” quality through the prices they charge, typically working on the assumption that shoppers think a high price indicates high quality. The resulting high prices hurt buyers, and may create a case for mandatory disclosure of quality through public policy.
That was a finding of the research of Dedman College’s Santanu Roy, professor, Department of Economics. Roy’s article about the research was published in February in one of the blue-ribbon journals, and the oldest, in the field, The Economic Journal.
Published by the U.K.’s Royal Economic Society, The Economic Journal is one of the founding journals of modern economics. The journal issued a media briefing about the paper, “Competition, Disclosure and Signaling,” typically reserved for academic papers of broad public interest.
Chemistry research group edits special issue
Chemistry professors Dieter Cremer and Elfi Kraka, who lead SMU’s Computational and Theoretical Chemistry Group, were guest editors of a special issue of the prestigious Journal of Physical Chemistry. The issue published in March.
The Computational and Theoretical research group, called CATCO for short, is a union of computational and theoretical chemistry scientists at SMU. Their focus is research in computational chemistry, educating and training graduate and undergraduate students, disseminating and explaining results of their research to the broader public, and programming computers for the calculation of molecules and molecular aggregates.
The special issue of Physical Chemistry included 40 contributions from participants of a four-day conference in Dallas in March 2014 that was hosted by CATCO. The 25th Austin Symposium drew 108 participants from 22 different countries who, combined, presented eight plenary talks, 60 lectures and about 40 posters.
CATCO presented its research with contributions from Cremer and Kraka, as well as Marek Freindorf, research assistant professor; Wenli Zou, visiting professor; Robert Kalescky, post-doctoral fellow; and graduate students Alan Humason, Thomas Sexton, Dani Setlawan and Vytor Oliveira.
There have been more than 75 graduate students and research associates working in the CATCO group, which originally was formed at the University of Cologne, Germany, before moving to SMU in 2009.
Vertebrate paleontology recognized with proclamation
Dallas Mayor Mike Rawlings proclaimed Oct. 11-17, 2015 Vertebrate Paleontology week in Dallas on behalf of the Dallas City Council.
The proclamation honored the 75th Annual Meeting of the Society of Vertebrate Paleontology, which was jointly hosted by SMU’s Roy M. Huffington Department of Earth Sciences in Dedman College and the Perot Museum of Science and Nature. The conference drew to Dallas some 1,200 scientists from around the world.
Making research presentations or presenting research posters were: faculty members Bonnie Jacobs, Louis Jacobs, Michael Polcyn, Neil Tabor and Dale Winkler; adjunct research assistant professor Alisa Winkler; research staff member Kurt Ferguson; post-doctoral researchers T. Scott Myers and Lauren Michael; and graduate students Matthew Clemens, John Graf, Gary Johnson and Kate Andrzejewski.
The host committee co-chairs were Anthony Fiorillo, adjunct research professor; and Louis Jacobs, professor. Committee members included Polcyn; Christopher Strganac, graduate student; Diana Vineyard, research associate; and research professor Dale Winkler.
KERA radio reporter Kat Chow filed a report from the conference, explaining to listeners the science of vertebrate paleontology, which exposes the past, present and future of life on earth by studying fossils of animals that had backbones.
SMU earthquake scientists rock scientific journal
Modelled pressure changes caused by injection and production. (Nature Communications/SMU)
Findings by the SMU earthquake team reverberated across the nation with publication of their scientific article in the prestigious British interdisciplinary journal Nature, ranked as one of the world’s most cited scientific journals.
The article reported that the SMU-led seismology team found that high volumes of wastewater injection combined with saltwater extraction from natural gas wells is the most likely cause of unusually frequent earthquakes occurring in the Dallas-Fort Worth area near the small community of Azle.
The research was the work of Dedman College faculty Matthew Hornbach, associate professor of geophysics; Heather DeShon, associate professor of geophysics; Brian Stump, SMU Albritton Chair in Earth Sciences; Chris Hayward, research staff and director geophysics research program; and Beatrice Magnani, associate professor of geophysics.
The article, “Causal factors for seismicity near Azle, Texas,” published online in late April. Already the article has been downloaded nearly 6,000 times, and heavily shared on both social and conventional media. The article has achieved a ranking of 270, which puts it in the 99th percentile of 144,972 tracked articles of a similar age in all journals, and 98th percentile of 626 tracked articles of a similar age in Nature.
“It has a very high impact factor for an article of its age,” said Robert Gregory, professor and chair, SMU Earth Sciences Department.
The scientific article also was entered into the record for public hearings both at the Texas Railroad Commission and the Texas House Subcommittee on Seismic Activity.
Researchers settle long-debated heritage question of “The Ancient One”
The skull of Kennewick Man and a sculpted bust by StudioEIS based on forensic facial reconstruction by sculptor Amanda Danning. (Credit: Brittany Tatchell)
The research of Dedman College anthropologist and Henderson-Morrison Professor of Prehistory David Meltzer played a role in settling the long-debated and highly controversial heritage of “Kennewick Man.”
Also known as “The Ancient One,” the 8,400-year-old male skeleton discovered in Washington state has been the subject of debate for nearly two decades. Argument over his ancestry has gained him notoriety in high-profile newspaper and magazine articles, as well as making him the subject of intense scholarly study.
Officially the jurisdiction of the U.S. Army Corps of Engineers, Kennewick Man was discovered in 1996 and radiocarbon dated to 8500 years ago.
Because of his cranial shape and size he was declared not Native American but instead ‘Caucasoid,’ implying a very different population had once been in the Americas, one that was unrelated to contemporary Native Americans.
But Native Americans long have claimed Kennewick Man as theirs and had asked for repatriation of his remains for burial according to their customs.
Meltzer, collaborating with his geneticist colleague Eske Willerslev and his team at the Centre for GeoGenetics at the University of Copenhagen, in June reported the results of their analysis of the DNA of Kennewick in the prestigious British journal Nature in the scientific paper “The ancestry and affiliations of Kennewick Man.”
The results were announced at a news conference, settling the question based on first-ever DNA evidence: Kennewick Man is Native American.
The announcement garnered national and international media attention, and propelled a new push to return the skeleton to a coalition of Columbia Basin tribes. Sen. Patty Murray (D-WA) introduced the Bring the Ancient One Home Act of 2015 and Washington Gov. Jay Inslee has offered state assistance for returning the remains to Native Tribes.
Science named the Kennewick work one of its nine runners-up in the highly esteemed magazine’s annual “Breakthrough of the Year” competition.
The research article has been viewed more than 60,000 times. It has achieved a ranking of 665, which puts it in the 99th percentile of 169,466 tracked articles of a similar age in all journals, and in the 94th percentile of 958 tracked articles of a similar age in Nature.
In “Kennewick Man: coming to closure,” an article in the December issue of Antiquity, a journal of Cambridge University Press, Meltzer noted that the DNA merely confirmed what the tribes had known all along: “We are him, he is us,” said one tribal spokesman. Meltzer concludes: “We presented the DNA evidence. The tribal members gave it meaning.”
Prehistoric vacuum cleaner captures singular award
Paleontologists Louis L. Jacobs, SMU, and Anthony Fiorillo, Perot Museum, have identified a new species of marine mammal from bones recovered from Unalaska, an Aleutian island in the North Pacific. (Hillsman Jackson, SMU)
Science writer Laura Geggel with Live Science named a new species of extinct marine mammal identified by two SMU paleontologists among “The 10 Strangest Animal Discoveries of 2015.”
The new species, dubbed a prehistoric hoover by London’s Daily Mail online news site, was identified by SMU paleontologist Louis L. Jacobs, a professor in the Roy M. Huffington Department of Earth Sciences, Dedman College of Humanities and Sciences, and paleontologist and SMU adjunct research professor Anthony Fiorillo, vice president of research and collections and chief curator at the Perot Museum of Nature and Science.
Jacobs and Fiorillo co-authored a study about the identification of new fossils from the oddball creature Desmostylia, discovered in the same waters where the popular “Deadliest Catch” TV show is filmed. The hippo-like creature ate like a vacuum cleaner and is a new genus and species of the only order of marine mammals ever to go extinct — surviving a mere 23 million years.
Desmostylians, every single species combined, lived in an interval between 33 million and 10 million years ago. Their strange columnar teeth and odd style of eating don’t occur in any other animal, Jacobs said.
As noted by the CERN Courier — the news magazine of the CERN Laboratory in Geneva, which hosts the Large Hadron Collider, the world’s largest science experiment — more than 250 scientists from 30 countries presented more than 200 talks on a multitude of subjects relevant to experimental and theoretical research. SMU physicists presented at the conference.
The SMU organizing committee was led by Fred Olness, professor and chair of the SMU Department of Physics in Dedman College, who also gave opening and closing remarks at the conference. The committee consisted of other SMU faculty, including Jodi Cooley, associate professor; Simon Dalley, senior lecturer; Robert Kehoe, professor; Pavel Nadolsky, associate professor, who also presented progress on experiments at CERN’s Large Hadron Collider; Randy Scalise, senior lecturer; and Stephen Sekula, associate professor.
Sekula also organized a series of short talks for the public about physics and the big questions that face us as we try to understand our universe.
SMU chemist Nicolay (Nick) Tsarevsky has received a prestigious National Science Foundation CAREER Award, expected to total $650,000 over five years, to fund his research into new methods of creating polymers — whose uses range from fluorescent materials to drug carriers, to everyday technologies.
NSF CAREER Awards are given to tenure-track faculty members who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research in American colleges and universities.
Tsarevsky, an assistant professor in the Department of Chemistry in SMU’s Dedman College of Humanities and Science, is a polymer chemist and the adviser to seven doctoral students who assist in his research. Polymers are molecules that can be found in just about anything and include both natural and synthetic materials. DNA and proteins are natural polymers, as is the cellulose found in wood and paper. Plastics are a group of synthetic polymers, as are many of the materials used in modern electronic technology. As the slogan for Tsarevsky’s lab group says, “It’s a polymer world…”
Prior to 20 years ago, the lab techniques used to make polymers with any precision approaching that of nature were very limited or didn’t exist. The Tsarevsky group specializes in developing methods to make large polymeric molecules in a lab with desired shapes, sizes and functionalities.
“We try to provide the tools, which can be used to prepare a vast number of complex functional materials,” says Tsarevsky, who, in a nod to history’s Stone, Bronze and Iron Ages, refers to our era as the ‘Polymer Age.’
“We make polymers that have the ability to kill bacteria on contact, and self-healing materials that you could break and that would heal by themselves,” Tsarevsky adds. “I like to think of our work as trying to design and control the architecture of very large molecules.”
Polymer research taps less toxic compounds and those with weaker bonds
To make complex macromolecules, Tsarevsky took advantage of the special behavior (reactivity) of a group of compounds that contain hypervalent chemical bonds. These bonds are weaker than other “classical” chemical bonds, and can be broken in two different ways as well as reconstructed. The atoms they connect can be “swapped” or exchanged — think building with Legos instead of permanent glue — enabling the construction of new materials that couldn’t be made otherwise. Several elements in the Periodic Table are able to form hypervalent bonds, but Tsarevsky feels iodine is one of the most attractive, in part because it’s less toxic than many alternatives.
Many of the current methods for making polymers use toxic heavy metals. The toxic impurities present in the final materials must be removed at potentially significant expense. The hypervalent iodine compounds Tsarevsky is employing aren’t just less toxic, they also allow for processes to be carried out using fewer steps than traditional methods to yield the final functional products. Another chemical element that also is promising for its diverse chemistry (including ability to form hypervalent bonds) and lack of toxicity is bismuth, which Tsarevsky would like to explore in his future research.
“The NSF CAREER funding is absolutely essential,” Tsarevsky says. “Some of the money will go to support doctoral students conducting the research, some will go to support supplies or equipment. Without this support, it would be extremely difficult or impossible to do these studies.”
Desire to show students that chemistry is beautiful, inspiring, allows creativity
Tsarevsky’s long-term educational goal is to increase interest in chemistry, a subject he says too many students are intimidated by.
“It’s only scary when you know nothing about it or when you had a bad teacher in school who made chemistry torture,” Tsarevsky says. “Without chemistry, we wouldn’t have pharmaceuticals or materials like plastics. We wouldn’t have many pigments or paints. Chemistry is not scary – it is beautiful and inspiring and allows you to be creative and make useful things nobody has seen before.”
Tsarevsky joined SMU in 2010. He was a chief science officer at ATRP Solutions, Inc., from 2007-10 and a visiting assistant professor at Carnegie Mellon University from 2005-07. Tsarevsky received a Ph.D. in chemistry from Carnegie Mellon University in 2005 and a Bachelor and Master of Science in theoretical chemistry and chemical physics from the University of Sofia, Bulgaria in 1999. — Kenneth Ryan
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“As a society, we are using more technology, and there’s increasing evidence that artificial light has had a negative consequence on our health,” says Zoltowski, who was awarded $320,500 from the National Institute of General Medical Sciences of the National Institutes of Health to continue its research on the impact of blue light.
“Our study uses physical techniques and chemical approaches to probe an inherently biological problem,” Zoltowski said. “We want to understand the chemical basis for how organisms use light as an environmental cue to regulate growth and development.”
By Doug Dunbar
CBS DFW 11
Can’t get a good night’s sleep. You might be getting a little too much blue light.
What’s that? It’s a big issue the Federal government is asking researchers at SMU to study.
There’s a reason why it’s dark in this lab. It’s because they’re studying light.
They have the lights off so they can purify the proteins in the dark.
So that we can study the activation process when we first expose them to light. But not just any light. Blue light. The stuff in fluorescents, and devices like laptops and phones. But also daylight.
One of the negative consequences of blue light is associated with our metabolic clock being offset from our brain clock. That can lead to problems for diabetes, cancer, mood disorders.
[ …] But Zoltowski and his crew could potentially tackle problems much bigger than sleeping.
“If we understand how these proteins that respond to light work we can create new biotechnology.”
Maybe new ways to deliver drugs, or even targeted cancer treatments.
“We can shine light on a very specific spot and that can allow us to activate any biological event we want at that very precise location and time.”
“We’re introducing blue light into the environment and into our daily lives at times when we’re not supposed to see it – and that basically causes dysfunction in our biological processes.” — Brian Zoltowski
KERA Public Radio journalist Justin Martin explored the good and bad of blue light in our environment with Brian Zoltowski, an assistant professor in the SMU Department of Chemistry.
“As a society, we are using more technology, and there’s increasing evidence that artificial light has had a negative consequence on our health,” says Zoltowski, who was awarded $320,500 from the National Institute of General Medical Sciences of the National Institutes of Health to continue its research on the impact of blue light.
“Our study uses physical techniques and chemical approaches to probe an inherently biological problem,” Zoltowski said. “We want to understand the chemical basis for how organisms use light as an environmental cue to regulate growth and development.”
By Justin Martin
KERA
Light is necessary for life on earth, but scientists believe that too much of a certain wavelength can cause everything from crop diseases to changes in the migratory patterns of animals. SMU professor Brian Zoltowski is working to unravel the mystery of blue light in a study funded by the National Institutes of Health.
Interview Highlights: Brian Zoltowski
… On what defines blue light:
“Blue light refers to a part of the electromagnetic spectrum that has specific energy. Usually we define things by basically their wavelength of light. So typically blue light can be centered around 450 nanometers but can range … from about 425 nanometers to 475 nanometers.”
… On the origin of excess blue light:
“Blue light is very abundant in nature in general. That’s why organisms actually use that wavelength of light to drive their biological processes. But it turns out though that because it’s abundant in nature, we like to have it to be abundant in our products like our lights, our computers, our laptops and everything else. So we introduce a lot more foreign blue light into the environment compared to what should naturally be there.”
… On blue light’s effects in animals vs. plants:
“A lot of that is not known, which is one of the reasons we’re actually doing a lot of this research. What we do know is that blue is extremely important for basically growth and development of any organism you can conceive of. How that’s ultimately regulated and when there can be too much is a big question. The bigger question is when you get the blue light, nature is designed to use blue light as a signal as to what time of day it is. So when we’re introducing blue light into the environment or into our daily lives through computers and laptops, we’re introducing blue light at times of day like evening when we’re not supposed to see it – and that basically causes dysfunction in our biological processes.”
… On how blue light fosters fungal growth:
“There’s growing understanding that a lot of these fungal pathogens of plants – there are several that actually attack wine, which causes billions of dollars of crop loss each year. There are some that we’re interested in that also basically attack a lot of your grain crops — so you’re looking at wheat, alfalfa — that have very detrimental aspects to agriculture. Their ability to infect the plant is regulated by blue light.”
Blue light from artificial lighting and electronic devices knocks circadian rhythms off-kilter, resulting in health problems, sleep, cancer development, mood disorders, drug addiction, crop disease and even confused migratory animals
A study funded by the National Institutes of Health is unraveling the mystery of how blue light from residential and commercial lighting, electronic devices and outdoor lights can throw off-kilter the natural body clock of humans, plants and animals, leading to disease.
At the right time of day, blue light is a good thing. It talks to our 24-hour circadian clock, telling our bodies, for example, when to wake up, eat and carry out specific metabolic functions.
In plants, blue light signals them to leaf out, grow, blossom and bloom. In animals, it aids migratory patterns, sleep and wake cycles, regulation of metabolism, as well as mood and the immune system.
But too much blue light — especially at the wrong time — throws biological signaling out of whack.
“As a society, we are using more technology, and there’s increasing evidence that artificial light has had a negative consequence on our health,” said Zoltowski, an assistant professor in SMU’s Department of Chemistry.
“Our study uses physical techniques and chemical approaches to probe an inherently biological problem,” he said. “We want to understand the chemical basis for how organisms use light as an environmental cue to regulate growth and development.”
The lab studies a small flowering plant native to Europe and Asia, Arabidopsis thaliana. The flower is a popular model organism in plant biology and genetics, Zoltowski said.
Although signaling pathways differ in organisms such as Arabidopsis when compared to animals, the flower still serves an important research purpose. How the signaling networks are interconnected is similar in both animals and Arabidopsis. That allows researchers to use simpler genetic models to provide insight into how similar networks are controlled in more complicated species like humans.
Understanding the mechanism can lead to targeted drug treatments
In humans, the protein melanopsin absorbs blue light and sends signals to photoreceptor cells in our eyes. In plants and animals, the protein cryptochrome performs similar signaling.
Much is known already about the way blue light and other light wavelengths, such as red and UV light, trigger biological functions through proteins that interact with our circadian clock. But the exact mechanism in that chemical signaling process remains a mystery.
“Light is energy, and that energy can be absorbed by melanopsin proteins that act as a switch that basically activates everything downstream,” Zoltowski said.
Melanopsin is a little-understood photoreceptor protein with the singular job of measuring time of day.
When light enters the eye, melanopsin proteins within unique cells in the retina absorb the wavelength as a photon and convert it to energy. That activates cells found only in the eye — called intrinsically photosensitive retinal ganglian cells, of which there are only about 160 in our body. The cells signal the suprachiasmatic nucleus region of the brain.
“We keep a master clock in the suprachiasmatic nucleus — it controls our circadian rhythms,” he said. “But we also have other time pieces in our body; think of them as watches, and they keep getting reset by the blue light that strikes the master clock, generating chemical signals.”
The switch activates many biological functions, including metabolism, sleep, cancer development, drug addiction and mood disorders, to name a few.
“There’s a very small molecule that absorbs the light, acting like a spring, pushing out the protein and changing its shape, sending the signal. We want to understand the energy absorption by the small molecule and what that does biologically.”
The answer can lead to new ways to target diabetes, sleep disorders and cancer development, for example.
“If we understand how all these pathways work,” he said, “we can design newer, better, more efficacious drugs to help people.”
Chemical signal from retina’s “atomic clock” synchronizes circadian rhythms
Besides increased reliance on artificial lighting indoors and outdoors, electronic devices also now contribute in a big way to blue light exposure. Endless evening hours on our smartphones and tablets with Candy Crush, Minecraft or Instagram don’t really help us relax and go to sleep. Just the opposite, in fact.
The blue glow those devices emit signals our circadian clock that it’s daytime, Zoltowski said. Red light, on the other hand, tells us to go to sleep.
Awareness of the problem has prompted lighting manufacturers to develop new lighting strategies and products that transition blue light to red light toward evening and at night, Zoltowski said.
Targeted solutions could neutralize destructive blight in staple crops
In plants, the researchers study how the absence of “true dark” in nature due to artificial light can reduce yields of farm crops and promote crop disease.
For example, fungal systems rely on blue light to proliferate, forming pathogens known as blight in crops resulting in leaves that look chewed on and reducing yields.
“We study fusarium and verticillium,” Zoltowski said. “They cause about $3 billion worth of crop damage a year to wheat, corn, soybeans — the staple food crops.”
Understanding their ability to infect crops would allow scientists to potentially design small molecules that target and disrupt the fungal system’s circadian clock and neutralize their proliferation.
Research to understand how light and clock regulation are coupled
In animals, Zoltowski’s lab studies the blue light pathway that signals direction to birds and other animals that migrate. Blue light activates the protein that allows various species to measure the earth’s magnetic field for directionality. For example, Monarch butterflies rely on the cryptochrome photoreceptor for their annual migration to Mexico.
“We’re interested in how these pathways are regulated in a diverse range of organisms to understand how we can manipulate these pathways to our advantage,” he said, “for health consequences and to improve agriculture yields.”
The researchers will map the reaction trajectory beginning from the initial absorption of the photon to the point it alters an organism’s physiology.
Zoltowski notes that light is just one of a handful of external cues from our environment that trigger biological processes regulating the circadian clock. Others include temperature changes, feeding and metabolites.
Besides the NIH grant, the lab operates with $250,000 from the American Chemical Society’s Herman Frasch Foundation for Chemical Research Grants in Agricultural Chemistry. — Margaret Allen
Scientific American science blogger Josh Fischman drew on the sleep expertise of SMU Assistant Professor of Chemistry Brian D. Zoltowski to explain how artificial light from our smartphones and other digital devices causes sleep deprivation. His blog article, “How your smartphone messes with your brain — and your sleep,” published May 20 and has been heavily shared through social media.
Zoltowski’s lab at SMU studies one of the many proteins involved in an organism’s circadian clocks. Called a photoreceptor, the protein responds to light to predict time of day and season by measuring day length.
The circadian clock is an internal biological mechanism that responds to light, darkness and temperature in a natural 24-hour biological cycle. The clock synchronizes body systems with the environment to regulate everything from sleep patterns and hunger in humans to growth patterns and flowering in plants.
“Our research focuses on understanding the chemical basis for how organisms perceive their surroundings and use light as an environmental cue to regulate growth and development,” Zoltowski says.
Zoltowski and the American Chemical Society created a video explaining the light-sleep deprivation relationship.
By Josh Fischman
Scientific American
It’s not the Angry Birds, streaming videos, emails from your boss, or your Facebook updates that disturb your sleep when you spend an evening staring at your smartphone or tablet. OK, the apps can keep you glued to your screen until the wee hours, and that doesn’t help. But it is the specific type of light from that screen that is throwing off your natural sleep-wake cycles, even after you power down. In a new video from Reactions: Everyday Chemistry, a sleep researcher explains the eerie power of blue light over your brain.
Cells at the back of your eyes pick up particular light wavelengths and, with a light-sensitive protein called melanopsin, signal the brain’s master clock, which controls the body’s circadian rhythms. Blue light, which in nature is most abundant in the morning, tells you to get up and get moving. Red light is more common at dusk and it slows you down. Now, guess what kind of light is streaming from that little screen in your hand at 11:59 P.M.? “Your iPad, your phone, your computer emit large quantities of blue light,” says sleep researcher and chemist Brian Zoltowski of Southern Methodist University
Business Insider Science Editor Jennifer Walsh tapped the sleep expertise of SMU Assistant Professor of Chemistry Brian D. Zoltowski to explain how artificial light from our smartphones and other digital devices causes sleep deprivation. Her article, “Your Smartphone Is Destroying Your Sleep,” published May 19.
Zoltowski’s lab at SMU studies one of the many proteins involved in an organism’s circadian clocks. Called a photoreceptor, the protein responds to light to predict time of day and season by measuring day length.
The circadian clock is an internal biological mechanism that responds to light, darkness and temperature in a natural 24-hour biological cycle. The clock synchronizes body systems with the environment to regulate everything from sleep patterns and hunger in humans to growth patterns and flowering in plants.
“Our research focuses on understanding the chemical basis for how organisms perceive their surroundings and use light as an environmental cue to regulate growth and development,” Zoltowski says.
Zoltowski and the American Chemical Society created a video explaining the light-sleep deprivation relationship.
By Jennifer Welsh
Business Insider
Artificial light is one of the biggest causes of sleep deprivation in modern humans, but there’s some special witch magic in smartphone and tablet light that really messes with our sleep cycle — essentially forcing us to stay awake by convincing our bodies that it’s actually morning.
Smartphones do this because they let off bright blue light.
“One of the best biological cues we have to what time of day it is is light. And it turns out that blue light in particular is very effective at basically predicting when morning is,” chemistry researcher Brian Zoltowski says in the video below, from the American Chemical Society.
In the evenings, there’s more red light than blue light, which signals your body to prep for bed. The red light does this by interacting with the protein melanopsin in cells deep inside your eyes — ones that are specifically made to regulate circadian rhythms and don’t play a role in how we see.
When the light hits this protein, it changes, and these cells send a signal to the “master clock” of the brain, which dictates when we wake and when we get sleepy. When it sends a “wake up” signal at night, our body clock gets screwed up.
The solution to a screwed up body clock? Force yourself to do things at the right time of the day — eating at mealtimes, getting to bed at a normal time, and getting up at a good time as well. And, of course, avoid that blue light at night.
Chemists develop chemical probe to help scientists study mechanics of critical signaling molecules, such as H2S, and to study how hydrogen sulfide benefits cardiovascular health
A new study confirms directly what scientists previously knew only indirectly: The poisonous “rotten egg” gas hydrogen sulfide is generated by our body’s growing cells.
Hydrogen sulfide, or H2S, is normally toxic, but in small amounts it plays a role in cardiovascular health.
In the new study, chemists developed a chemical probe that reacts and lights up when live human cells generate hydrogen sulfide, says chemist Alexander R. Lippert, Southern Methodist University, Dallas. The discovery allows researchers to observe the process through a microscope.
The researchers captured on video the successful chemical probe at work, said Lippert, an assistant professor in the SMU Department of Chemistry.
“We made a molecular probe that, when it reacts with hydrogen sulfide, forms a fluorescent compound that can be visualized using fluorescence microscopy,” Lippert said. “This is the first time that endogenously generated hydrogen sulfide has been directly visualized in a living system. This confirms a lot of hypotheses that scientists have, but no one had the tools to directly detect it in real time.”
H2S is one of several small gaseous molecules increasingly recognized as key signaling molecules in the body. For example, H2S helps reduce high blood pressure. Scientists discovered in the past decade that cells in the human body generate small quantities of H2S molecules, which in turn deliver information to proteins. The proteins act on the information to perform critical functions in the body.
Previously, scientists couldn’t observe H2S being generated in live cells. As a result, researchers faced challenges when studying hydrogen sulfide in living systems, Lippert said. The new discovery now provides a tool to view directly how and when hydrogen sulfide is generated, he said. Lippert and study co-author chemist Vivian S. Lin made the discovery.
Discovery provides research tool for scientists to observe H2S in live cells
“Having the tools to do this in living systems is going to open up a lot of possibilities and experiments for scientists,” Lippert said. “As a tool, this will allow researchers to ask questions that weren’t possible before.”
Lippert’s real-time video features live human cells, taken from the lining of blood vessels and treated with the chemical probe and with a protein known to promote cell growth. Once the cells start generating H2S, they behave like squiggly fluorescent green worms.
Lippert and Lin authored the research with Christopher J. Chang, principal investigator. Lin is a PhD candidate at the University of California at Berkeley. Chang is with the Howard Hughes Medical Institute, University of California at Berkeley. Lippert and Lin carried out the research in Chang’s UC Berkeley laboratory.
Discovery can help scientists attack diseases such as cancer
H2S — along with nitric oxide, carbon monoxide and others in this emerging class of gaseous signaling molecules — assists the body’s large proteins.
Large proteins do much of the functional work in the body, such as digesting the food we eat and harnessing the energy in the oxygen we breathe. Their size, however, forces them to move slowly inside the cell. In contrast, H2S and other small gaseous molecules diffuse quickly and easily across cellular membranes, enabling them to travel much faster and rapidly deliver information that mediates critical functions, such as blood pressure regulation, Lippert said.
For their experiments, Lippert and Lin placed living endothelial cells cultured from the internal lining of a blood vessel into a petri dish under a microscope.
Lippert and Lin then added a chemical solution containing an azide-functionalized organic molecule that they’d synthesized to act as a molecular probe. They gave the cells time to absorb the probe, then added a protein solution known to stimulate blood vessel formation. As the cells initiated blood vessel formation, H2S was generated. In reaction, the scientists observed a steady increase in the probe’s fluorescence.
“Essentially we’re observing the initial events that lead to the building of new blood vessels, a process that’s active in babies as they develop, or in women during their menstruation cycles,” Lippert said. “We see the cells get really bright as they start moving around and ruffling their membranes. That’s the H2S being formed. In the control group, which weren’t stimulated with the growth protein, they don’t get any brighter and they don’t move around.”
The discovery provides new insights that can help scientists attack diseases, such as cancer, by starving the nutrient supply to a tumor, Lippert said.
“When tumors grow they need a lot of blood support because they need the nutrients to support their rapid growth,” he said. “If you can stop blood vessel formation you could starve the tumor and the tumor will die. So inhibiting H2S formation might be a way to treat cancer using this method.” — Margaret Allen
Understanding of photoreceptor proteins could lead to new strains of plants tolerant to greater variety of environments, and to cancer drug therapy for humans
How does a plant know when to sprout a leaf, fold its petals or bloom? Why do humans experience jet lag after a trip abroad?
The answer is the internal circadian clocks that are present in nearly every organism and that respond to external cues such as light and temperature, says chemist Brian D. Zoltowski, Southern Methodist University.
Zoltowski’s lab at SMU studies one of the many proteins involved in an organism’s circadian clocks. Called a photoreceptor, the protein responds to light to predict time of day and season by measuring day length.
$250,000 grant will fund research studying circadian clocks in plants
The photoreceptor protein enables plants to know when spring and fall occur and to produce flowers or fruit at the appropriate time of year, says Zoltowski, an assistant professor in SMU’s Department of Chemistry. The protein also allows plants to collect energy during the day in the scientific process called photosynthesis, and then refocus energy to grow at night.
Human photoreceptors also are intricately involved in regulation of the body’s circadian clocks. They have been implicated in the development of cancer and diabetes, as well as neurological illnesses.
“If we can better understand how these proteins work, we can potentially re-engineer them or develop small molecules to regulate flowering times, plant growth and development,” Zoltowski says. “By extension, we can potentially design therapeutics for the human circadian clocks.”
The Herman Frasch Foundation for Chemical Research Grants in Agricultural Chemistry awarded Zoltowski a five-year $250,000 agricultural chemistry grant to fund the plant research. The foundation is part of the American Chemical Society.
A natural 24-hour biological mechanism for regulating the body
The circadian clock is an internal biological mechanism that responds to light, darkness and temperature in a natural 24-hour biological cycle. The clock synchronizes body systems with the environment to regulate everything from sleep patterns and hunger in humans to growth patterns and flowering in plants.
“Our research focuses on understanding the chemical basis for how organisms perceive their surroundings and use light as an environmental cue to regulate growth and development,” Zoltowski says.
Zoltowski’s research focuses on a family of proteins related to Zeitlupe, a photoreceptor protein that is sensitive to blue light and historically considered responsible for regulating the circadian clock.
Light induces chemical reaction and resulting cascade of interactions
“We isolate the protein so we can study directly how it works independent of everything else,” Zoltowski says. “So we look at the chemistry that is sensitive to blue light when the blue-light photon is absorbed by the protein. We figure out the chemistry and then how the chemistry changes the structure of the protein.”
For example, he says, for a flower to open, light induces a chemical reaction in the protein that alters the way it’s configured, which then starts a cascade of interactions that changes the plant’s physiology completely.
The researchers use a combination of X-ray crystallography, nuclear magnetic resonance and solution biophysics to identify the fundamental chemical mechanisms of photo-activation, including local chemical events, alteration in protein structure and alteration in protein:protein interactions.
Goal is for discoveries that can regulate a plant’s circadian clock
By understanding how the proteins work, scientists can ultimately create new strains of plants that are tolerant to more environments, says Zoltowski. In related research, the study of human proteins can reveal circadian clock irregularities that play a role in diseases such as diabetes by disrupting the release of glucose, for example. From that research, scientists can develop new drug therapeutics to treat the illness.
“We’re having great success. We’ve worked with these families of proteins for a long time, so we have some strategies that improve the likelihood of making it work,” Zoltowski says. — Margaret Allen
CBS Channel 11 reporter Ginger Allen interviewed SMU chemist Brian Zoltowski for the station’s Aug. 15 report on aerial spraying over Dallas County to kill mosquitos that may be carrying West Nile Virus.
The report comes in the wake of a decision by Dallas County to address the spread of West Nile Virus with aerial spraying of a pesticide called Duet.
Zoltowski, an SMU assistant professor of chemistry, was asked about the possible impact of the pesticide on human health.
Reporting: Ginger Allen
CBS Channel 11 DFW
DALLAS (CBS 11 NEWS) – West Nile poses a serious health risk, but now with aerial spraying, there is a new concern. What could soon rain down over Dallas County may flood doctors’ offices with questions.
Doctor Elizabeth Stevenson is an OB/GYN who says, “Unfortunately, right now, we don’t have a whole lot of information.”
Although Doctor Stevenson has delivered more than 4,000 babies, she, like the rest of us, is waiting to hear what the chemicals that kill mosquitoes could do to at risk patients like infants and pregnant women.
“We are going under the assumption that this will not be harmful to mother or unborn child,” says Doctor Stevenson.
CBS 11 has learned Dallas County will be using Clarke, an Illinois company to spray the pesticide called Duet. Duet contains sumithrin and pralletrin.
“If you ever take Raid and spray on a bug, they basically drop to the ground. That is what they are designed to do. They basically stop their ability to move,” explains Southern Methodist University Associate Professor Brian Zoltowski.
Zoltowski says these are chemicals that the pest control companies have being spraying on yards for years. He says the amounts that will be sprayed will kill mosquitoes, bees and fish. They do not have the protective enzymes to degrade the molecules that people and pets do. […]
The online science news site Science Daily has covered the research of SMU Chemistry Department Professor John A. Maguire.
The June 21 article “Scientists Find Simple Way to Produce Graphene” reports the news that Maguire and a team lead by scientists from Northern Illinois University have discovered a simple method for producing high yields of graphene, a highly touted carbon nanostructure that some believe could replace silicon as the technological fabric of the future.
By Science DailyScientists at Northern Illinois University say they have discovered a simple method for producing high yields of graphene, a highly touted carbon nanostructure that some believe could replace silicon as the technological fabric of the future.
The focus of intense scientific research in recent years, graphene is a two-dimensional material, composed of a single layer of carbon atoms arranged in a hexagonal lattice. It is the strongest material ever measured and has other remarkable qualities, including high electron mobility, a property that elevates its potential for use in high-speed nano-scale devices of the future.
In a June communication to the Journal of Materials Chemistry, the NIU researchers report on a new method that converts carbon dioxide directly into few-layer graphene (less than 10 atoms in thickness) by burning pure magnesium metal in dry ice.
“It is scientifically proven that burning magnesium metal in carbon dioxide produces carbon, but the formation of this carbon with few-layer graphene as the major product has neither been identified nor proven as such until our current report,” said Narayan Hosmane, a professor of chemistry and biochemistry who leads the NIU research group.
Investigators at SMU and the University of Texas at Dallas have discovered a family of small molecules that shows promise in protecting brain cells against nerve-degenerative diseases such as Parkinson’s, Alzheimer’s and Huntington’s. SMU’s work is led by Chemistry Department Professor Edward R. Biehl.
Health care journalist Bill Hethcock covered the research for The Dallas Business Journal. Hethcock’s Feb. 25 article “Firm is out to prevent neuron loss” details how Dallas-based startup EncephRx Inc. was granted worldwide license to develop the jointly owned compounds.
EXCERPT:
By Bill Hethcock
Dallas Business Journal
Dallas-based biotech startup EncephRx Inc. is working with researchers at the University of Texas at Dallas and Southern Methodist University to develop treatments for Huntington’s, Parkinson’s and Alzheimer’s diseases. Already, there have been signs of promise in animal testing. The company is seeking $1 million in grants and private equity to begin pre-clinical testing in the next year.
The goal is to develop and commercialize treatments that prevent the progressive loss of neurons that characterize the diseases, said Aaron Heifetz, CEO of EncephRx. Available medications attempt to relieve symptoms, but don’t prevent neuron loss and disease progression, he said.
Investigators at Southern Methodist University and The University of Texas at Dallas have discovered a family of small molecules that shows promise in protecting brain cells against nerve-degenerative diseases such as Parkinson’s, Alzheimer’s and Huntington’s, which afflict millions.
Dallas-based startup EncephRx, Inc. was granted the worldwide license to the jointly owned compounds. A biotechnology and therapeutics company, EncephRx will develop drug therapies based on the new class of compounds as a pharmaceutical for preventing nerve-cell damage, delaying onset of degenerative nerve disease and improving symptoms.
Treatments currently in use don’t stop or reverse degenerative nerve diseases, but instead only alleviate symptoms, sometimes with severe side effects. If proved effective and nontoxic in humans, EncephRx’s small-molecule pharmaceuticals would be the first therapeutic tools able to stop affected brain cells from dying.
“Our compounds protect against neurodegeneration in mice,” said synthetic organic chemist Edward R. Biehl, the SMU Department of Chemistry professor who led development of the compounds at SMU. “Given successful development of the compounds into drug therapies, they would serve as an effective treatment for patients with degenerative brain diseases.”
EncephRx initially will focus its development and testing efforts toward Huntington’s disease and potentially will have medications ready for human trials in two years, said Aaron Heifetz, CEO at EncephRx.
Compounds developed by SMU and UTD collaboration
Biehl developed the compounds in collaboration with UT Dallas biology professor Santosh R. D’Mello, whose laboratory has been studying the process of neurodegeneration for several years.
“Additional research needs to be done, but these compounds have the potential for stopping or slowing the relentless loss of brain cells in diseases such as Alzheimer’s and Parkinson’s,” said D’Mello, professor of molecular and cell biology at UT Dallas, with a joint appointment in the School of Brain and Behavioral Science. “The protective effect that they display in tissue culture and animal models of neurodegenerative disease provides strong evidence of their promise as drugs to treat neurodegenerative disorders.”
Millions are suffering, particularly the elderly
Parkinson’s, Huntington’s and Alzheimer’s are disorders of the central nervous system marked by abnormal and excessive loss of neurons in a part of the mid-brain, say the researchers.
The diseases steadily erode motor skills, including speech and the ability to walk, cause tremors, slowed movement, stooped posture, memory loss and mood and behavior problems.
The risk of developing a degenerative nerve disease increases with age. These diseases affect more than 5 million Americans.
Novel compounds effectively proved protective in initial studies
One member of a class of heterocyclic organic compounds, the synthetic chemicals developed and tested by SMU and UT Dallas scientists, was shown to be highly protective of neurons in tissue culture models and effective against neurodegeneration in animal models.
The most promising lead compound, designated HSB-13, was tested in Huntington’s disease animal models. It not only reduced degeneration in a part of the forebrain but also improved behavioral performance while proving nontoxic. The compound also was efficacious in a commonly used fly model of Alzheimer’s disease.
“These preliminary tests demonstrated that the compound was an extremely potent neuroprotective agent,” Biehl said.
The SMU and UT Dallas researchers developed and tested more than 100 compounds for neuroprotective efficacy and toxicity over the course of four years before making the discovery in 2007.
Interinstitutional partnership with EncephRx
SMU researchers will assist EncephRx in optimizing the primary compound, and the UT Dallas team will support testing and analysis.
“While discovery of the compounds is a major accomplishment, many hurdles remain,” Biehl said.
EncephRx is a university spinout formed to develop and commercialize the compounds. Its management team has proven success in all facets of drug development and has developed more than a dozen chemical compounds.
Aaron Heifetz, president and chief executive officer of EncephRx, Inc., said, “We believe this library of novel neuroprotective compounds will prove an important step in the effort to improve the health for patients with neurodegenerative diseases, such as Huntington’s disease, Alzheimer’s disease and Parkinson’s disease.”
Chris Jeffers, managing partner of FirstStage Bioventures, the parent company of EncephRx, added, “FirstStage is very excited about this technology and looks forward to helping EncephRx quickly move these compounds into the clinic.”
SMU has an uplink facility on campus for live TV, radio or online interviews. To speak with Dr. Biehl or Dr. D’Mello or to book them in the SMU studio, call SMU News & Communications at 214-768-7650 or UT Dallas Office of Media Relations at 972-883-4321.
SMU is a private university in Dallas where nearly 11,000 students benefit from the national opportunities and international reach of SMU’s seven degree-granting schools. For more information see www.smu.edu.
Brent Sumerlin, associate professor of Chemistry in SMU’s Dedman College, has been named a 2010-2012 Alfred P. Sloan Research Fellow. This exceptionally competitive award will provide Sumerlin a grant of $50,000 over two years to support his research, some of which could lead to the use of nano-scale polymer particles to automatically deliver insulin to diabetics.
The Sloan Research Fellowships are designed to stimulate fundamental research by early-career scientists and scholars of outstanding promise. These two-year fellowships are awarded yearly to 118 researchers in recognition of distinguished performance and unique potential to make substantial contributions to their field.
The fellowship places Sumerlin in the company of some of the most distinguished scientists in the country. Thirty-eight Sloan fellows have been awarded the Nobel Prize in their respective fields since the fellowships were established in 1955.
Gary E. Pittman received the 2008 Distinguished Alumni Award, the highest award SMU can bestow upon its former students. Pittman and other recipients were honored at the November DAA celebration.
Pittman is a multifaceted researcher, whose discovery has transformed the electronics world and our daily lives. While working at Texas Instruments in the 1960s, he and a colleague co-invented the light emitting diode. More commonly known now as the LED, the invention led to formation of the multi-billion-dollar optical communications industry.
Other applications of LEDs include traffic lights, railroad crossing signals, exit signs and digital clocks. Their major contribution is for illumination, leading to a great reduction in energy needs.
In 1953, Pittman earned his B.S. degree in chemistry with honors from SMU, where he became a member of Phi Beta Kappa. He later took graduate courses in electronics. He has lectured and conducted seminars throughout the United States and in Mexico and London.
After leaving Texas Instruments, Pittman served as vice president for manufacturing at Spectronics Inc., director of military business at Honeywell Optoelectronics and president of SPC, Inc. Gary E. Pittman
He currently is a consultant in statistical thinking, engaged in research including novel methods of energy reduction for homes and improved use of statistics for medical purposes. The Galton Institute in London published Pittman’s book on Sir Francis Galton, the developer of modern statistical methods. SMU’s DeGolyer Library now houses Pittman’s collection of Galton materials, the finest in the U.S.
Pittman received the Lazenby Outstanding Alumnus Award from the SMU Chemistry Department in 2008.
Chemist Brent Sumerlin, assistant professor in the Dedman College Department of Chemistry at Southern Methodist University, is assessing the potential uses for nano-scale polymer particles. One of those could be controlled drug delivery.
In one scenario, polymers could detect high glucose levels in a diabetic’s blood stream and automatically release insulin, freeing diabetics from a daily injection schedule.
Sumerlin’s research has earned him a $475,000 National Science Foundation Faculty Early Career Development Award. NSF gives the award to junior faculty members who exemplify the role of teacher-scholars in American colleges and universities.
Sumerlin will receive the grant over five years for two related nanotechnology research projects. One of those projects has potential biomedical applications, and the other has a promising advanced materials application.
The prestigious award also includes support for education outreach. Sumerlin’s grant will fund a program for K-12 school districts and community colleges to help prepare and attract minority students for SMU chemistry internship positions.
“As a teacher, as a scientist, and through his community outreach and service, Professor Sumerlin exemplifies the finest scholarly tradition,” said Cordelia Candelaria, dean of Dedman College of Humanities and Sciences. “His work is dedicated to expanding minds through exposure to basic science, including a generous willingness to share his lessons and labs off campus with teachers and students in elementary, middle and high school classrooms. Dedman College is thrilled by NSF’s recognition of Brent’s achievements.”
Sumerlin, 32, works with an SMU team of postdoctoral research associates, graduate and undergraduate students who fuse the fields of polymer, organic and biochemistries to develop novel materials with composite properties.
“This award enhances what I do at the university level and what I can do through SMU for the rest of the community,” Sumerlin said.
The first part of Sumerlin’s NSF-funded research will investigate how nano-scale polymer particles can be triggered to come apart in response to a chemical stimulus. One of the potential applications of the technology is an automatic treatment solution for diabetics by releasing insulin from tiny polymer spheres when they encounter dangerous levels of glucose in the bloodstream.
“Researchers worldwide are looking toward methods of insulin delivery that will relieve diabetics of frequent blood-sugar monitoring and injections,” Sumerlin said.
The second aspect of the project involves making polymers with the ability to come apart and put themselves back together again – a technique that Sumerlin believes can be used to construct materials that are self-repairing.
“We could potentially think about coatings for airplane wings that are damaged by debris during flight,” Sumerlin said. “After landing, we could quickly treat the coating, causing it to re-form itself.”
Sumerlin received his doctorate from the University of Southern Mississippi in 2003, accepted a position as visiting assistant professor at Carnegie Mellon University for the next two years, then joined SMU in 2005.
Researchers at Southern Methodist University and The University of Texas at Dallas have identified a group of chemical compounds that slows the degeneration of neurons, a condition that causes such common diseases of old age as Alzheimer’s, Parkinson’s and amyotropic lateral sclerosis.
SMU Chemistry Professor Edward R. Biehl and UTD Biology Professor Santosh R. D’Mello teamed to test 45 chemical compounds. Four were found to be the most potent protectors of brain cells, or neurons.
Their findings were published in the November 2008 issue of “Experimental Biology and Medicine.”
The synthesized chemicals, called “substituted indolin-2-one compounds,” are derivatives of another compound called GW5074 that was shown to prevent neurodegeneration in a past report published by the D’Mello lab.
While effective at protecting neurons from decay or death, GW5074 is toxic to cells at slightly elevated doses, which makes it unsuitable for clinical testing in patients. The newly identified, second generation compounds maintain the protective feature of GW5074 but are not toxic, even at very high doses, and hold promise in halting the steady march of neurodegenerative diseases like Alzheimer’s and Parkinson’s.
“Sadly, neurodegenerative diseases are a challenge for our elderly population,” D’Mello said. “People are living longer and are more impacted by diseases like Alzheimer’s, Parkinson’s and Amyotrophic Lateral Sclerosis than ever before, which means we need to aggressively look for drugs that treat diseases. But most exciting now are our efforts to stop the effects of brain disease right in its tracks. Although the newly discovered compounds have only been tested in cultured neurons and mice, they do offer hope.”
The most common cause of neurodegenerative disease is aging. Current medications only alleviate the symptoms but do not affect the underlying cause, which is degeneration of neurons. The identification of compounds that inhibit neuronal death is thus of urgent and critical importance.
The new compounds may offer doctors an option beyond just treating the symptoms of neurodegenerative diseases. The development isn’t a cure, but doctors may be able to one day use compounds that stop cell death in combination with currently existing drugs that battle the symptoms of brain diseases. The combination of stopping the disease in its tracks while treating disease symptoms can offer hope to people suffering and the families impacted by these diseases.
David Son uses some of the Earth’s most common building blocks to create complex new materials with potential wide-ranging applications.
Son conducts research on polymers containing silicon. One of the main elements in the Earth’s crust, silicon is the major ingredient in common sand, and is readily available.
“It’s fairly easy and inexpensive to transform silicon into compounds we can manipulate,” says Son, associate professor in SMU’s Department of Chemistry in Dedman College. “And because silicon is an inorganic element, it gives materials great stability against temperature changes and oxidation.”
Silicon-containing polymers might be used to create more heat-resistant and longer-lasting plastic materials than common organic polymers such as polyethylene or PVC, Son says. One example is the silicone ovenware widely available in stores. Pans made of silicon polymers are temperature-safe, naturally nonstick, and so flexible that they can be turned inside out to remove baked goods.
Most polymers are what chemists call the straight-chain type, with each molecule consisting of atoms laid more or less end-to-end. Son’s research focuses on a new class of polymers called dendrimers, also known as “arborols” for their molecular resemblance to trees with many branches.
The dendrimers’ structure gives them many advantages.
“You can dissolve them much more easily in solvents,” Son says. “Because the molecules are shaped like balls, they roll right over each other and don’t get tangled up the way straight-chain polymers do, so you can use them as lubricants.”
Other possible uses include new drugs in which medicines are encapsulated in the dendrimers’ branches, transported to targeted areas of the body, and then stimulated to release medication directly to those sites.
Most recently, Son has begun creating materials that merge metal ions with organic compounds called ligands. Ligands can be as simple as water or as complex as ethylenediaminetetraacetic acid, or EDTA, a compound commonly used as an anticoagulant in medicine.
Son is especially interested in how nitrogen- and sulfur-based ligands bond with silver, gold, palladium, and platinum, which are elements with well-established catalytic properties. He hopes to create compounds that can be used to improve everything from optics to plastics manufacturing.
Platinum and palladium compounds are used industrially to spark reactions in other materials. Creating better catalysts, Son says, could enable more efficient manufacturing processes, for example, at lower temperatures or with fewer defects.
Fermilab experiment observes change in neutrinos from one type to another over 500 miles
Large genome-scale study finds Native American ancestors arrived in single migration wave
$3.78 million awarded by Department of Defense to SMU STEM project for minority students
Kennewick Man: genome sequence of 8,500-year-old skeleton solves scientific controversy
At peak fertility, women who desire to maintain body attractiveness report they eat less
SMU seismology team to cooperate with state, federal scientists in study of May 7 Venus, Texas earthquake
1st proton collisions at the world’s largest science experiment expected to start the first or second week of June
Most likely cause of 2013-14 earthquakes: Combination of gas field fluid injection, removal
Other applications of LEDs include traffic lights, railroad crossing signals, exit signs and digital clocks. Their major contribution is for illumination, leading to a great reduction in energy needs.
