Author: Jillian Chambers

New Method Unearths Climate Data from Ancient Soils

Hren By Elaina Hancock, UConn Communications

In Scientific Reports today, UConn researchers report a novel approach to reconstructing ancient climates using analyses of organic compounds in sediments and soils.

This method was developed by former UConn postdoctoral scientist Yvette Eley (now in the Department of Geography, Earth and Environmental Sciences at the University of Birmingham, U.K.) and assistant professor Michael Hren in the UConn Center for Integrative Geosciences. Their new approach makes use of organic compounds found in the waxy, lipid-rich cuticle of plants. These waxy surfaces are critical to plant survival, as they minimize water loss and provide protection from factors such as UV radiation.

The distribution of organic compounds in leaf waxes records information about their growing environment. For instance, when confronted with stressful conditions such as shortage of water, plants can respond by changing the distribution of organic compounds in their leaf wax to combat water loss and improve their chances of survival. Various environmental parameters can therefore result in plants with different distributions of lipids, and these profiles can reveal a lot about the climate those plants were growing in.

Once incorporated into the soil, these organic compounds can be preserved over tens to hundreds of millions of years, offering the potential to quantify changes to regional and global moisture budgets on geologic timescales. The leaf wax lipids are extracted from soils and sediments, which are complex mixtures containing, among many other components, weathered rock, minerals, and decayed plant materials that have accumulated over time.

“Looking at soil today, you’re observing the integrated history of all the plant matter that went into forming that soil over the course of hundreds to thousands of years,” says Hren.

In the past, various methods have been used to give a snapshot of environmental conditions at a point in time, such as analyzing stable isotopes in mammal bones and teeth, or looking at the chemistry of ice cores. However, all methods have limits to the information they can provide.

Eley and Hren investigated the relationship between leaf wax biomarker profiles and modern climate in a series of soils from North and Central America. A clear relationship began to emerge regarding leaf wax lipid distribution profiles and atmospheric moisture, suggesting that it is possible to use the distribution of leaf wax lipids to identify changes in moisture availability in the past.

This new approach represents a significant addition to the paleoclimate scientist’s toolkit, as atmospheric moisture is a parameter that has been challenging to estimate over long periods of Earth history, until now.

With today’s increasing CO2 levels, scientists know there is going to be climate change in the future, but it has not been clear how that may affect regional moisture patterns.

“One of the huge gaps in the past is we didn’t have great quantitative records of moisture,” says Hren. “We’re now managing to get a really nice glimpse of the whole ecosystem and how it’s responding.”

As the researchers focus on the biomarker profiles of soils, they are capturing an integrated chemical signature of a whole ecosystem preserved in ancient soils and sediments.

Hren says they found that the distribution of organic compounds preserved in soils of these ecosystems seems to be strongly related not just to relative humidity, but also to the difference between how much water is in an air mass and how much the air mass can hold, or what is known as the vapor pressure deficit.

Once the researchers established this relationship using modern data, they applied the method to sediments dating back to between 16.5 and 12.4 million years from a well studied area in Spain. They were able to reconcile their lipid-based reconstruction of vapor pressure deficit with existing stable isotope and fossil data for the area, highlighting the utility of this new tool.

Says Eley, “The hope is that we’ll be able to use this approach to tackle key questions about changing moisture availability over time.”

Past, present, and future

Hren and Eley are now applying this method to a range of other ancient terrestrial sediments, to investigate the relationship between changes in past climate and atmospheric moisture. They hope to use insights from these studies, which reconstruct temperature and moisture availability over many millions of years of Earth’s history, to advance understanding of the global changes in environmental conditions anticipated in the coming decades.

“By looking into the past, we’re trying to understand the potential for future change,” says Hren. “This is a powerful tool as we move forward.”

The ultimate hope is that data generated by this new leaf wax biomarker proxy will improve knowledge of past climate responses to CO2, and fill in the gaps – like missing pieces of a puzzle – in spatial reconstructions of paleoclimate during past warm periods of earth history. This in turn will feed into climate predictions of the long-term future of our planet.

This work was supported by a National Science Foundation grant NSF-EAR-1338256.

Chemistry Professor Nationally Recognized for Inventions

By Jessica McBride, Office of the Vice President for Research

Altug Poyraz, left, a graduate student, with Steven Suib, Board of Trustees Distinguished Professor of Chemistry. According to Suib, some of the greatest benefits of being an academic inventor are the opportunities it allows him to provide to his students, many of whom will work in industry after graduating from UConn. (Peter Morenus/UConn File Photo)

Board of Trustees Distinguished Professor of Chemistry Steven L. Suib has some advice for early career faculty and student researchers who are interested in inventing. Given that Suib was recently named a fellow of the National Academy of Inventors (NAI), it would probably be smart to grab a pencil.

“Ask a lot of questions, know the literature, don’t be afraid to move on from ideas that just aren’t working. But above all, keep an open mind and work with other people,” offered Suib.

Throughout his nearly 40-year research career, Suib has lived by these words. As a preeminent expert in solid state chemistry and the synthesis of novel materials with a strong environmental focus, his work has produced numerous discoveries with a variety of applications in several industry sectors.

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Tailoring Treatment to Combat Diseased Cells at the Genetic Level

By Jessica McBride, Office of the Vice President for Research

Jessica Rouge, Assistant Professor talking with Ph.D. student Josh Santiana in her research lab in the Chemistry building on Nov. 29, 2017. (Sean Flynn/UConn Photo)

A new drug delivery system that uses a synthetic-biological hybrid nanocapsule could provide a smart technology for targeted treatment of a variety of serious diseases at the genetic level.

The hybrid offers a way to correct diseased cells at the genetic level – while at the same time leaving healthy cells alone – to increase the effectiveness of treatments and reduce unwanted side effects.

“There’s no one-size-fits-all delivery system,” says Jessica Rouge, assistant professor of chemistry at UConn, and author of a new paper on the technology in Bioconjugate Chemistry. “The beauty of this system is that it is programmable, modular, and has the ability to rapidly integrate diverse peptide sequences. It can be tailored to combat new disease challenges as they emerge.”

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Professor Flavio Maran Wins Baizer Award

Flavio MaranProfessor Flavio Maran, who leads the Molecular Electrochemistry and Nanosystem Group at the University of Padova and is a Research Professor in the Department of Chemistry at the University of Connecticut, is the new winner of the Manuel M. Baizer Award, awarded by the Electrochemical Society (ECS), which is the largest electrochemical society. The Baizer Award (Manuel Baizer was a great chemist and foremost internationally recognized authority in organic electrosynthesis) was established in 1992 to recognize individuals for their outstanding scientific achievements in the electrochemistry of organics and organometallic compounds, carbon-based polymers and biomass, whether fundamental or applied, and including but not limited to synthesis, mechanistic studies, engineering of processes, electrocatalysis, devices such as sensors, pollution control, and separation/recovery. Prof. Maran will give his Award Lecture in May 2018, at the 233rd ECS Meeting in Seattle, Washington.

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Fishing for New Antibiotics

Kim Krieger, UConn Communications

Two potent antibacterials found in fish do their dirty work in unexpected ways, report UConn chemists and colleagues in a paper accepted by the FEBS Journal. The research could point the way to entirely new classes of antibiotics.

Fish suffer from bacterial infections just like humans do. It’s an especially tough problem for farmed fish, which live in close quarters where sickness can spread quickly. Fish farmers know that adding copper sulfate to the water reduces bacterial disease, but they haven’t understood why. Now, a team led by chemists from UConn has discovered that fish make antibacterial peptides that bind to copper and use it as a weapon to slay bacteria.

Peptides are small molecules, made from the same stuff as proteins but much shorter. Biologists knew that these fish peptides, called piscidin-1 and piscidin-3, were antibacterial. But it took a chemist to figure out the copper connection.

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2016-2017 Graduate Student Awards

The following awards were presented at the Chemistry Department’s Annual Safety Training on August 24, 2017. 
Waring (Scholastic) Award: Highest GPA for the 2016-2017 class.
Tianqi (Kiki) Chen (Rusling)
Masterton (Teaching) Awards: To be recommended by the TA committee or by instructors who may nominate their TAs for excellence in teaching. 
Islam Mosa (Rusling)
Mohamed Sharafeldin (Rusling)
Murali Anuganti (Lin)
Megan Puglia (Kumar)
Shelli Miller (Leadbeater)
Connecticut Chemistry Research Award: List of publications of the graduate student with full citations, and a nomination letter from the major advisor describing research contributions of the student.
Kyle Lambert (Bailey)
Karteek Kadimisetty (Rusling)
Outstanding Service and Research AwardNomination letter from faculty and/or staff describing specific activities or service provided to the department by the student, and a list of publications of the graduate student with full citations, and a nomination letter from the major advisor describing research contributions of the student.
Shannon Poges  (Suib)
Excellence in Service Award; Nomination letter from faculty or staff describing outstanding service by a graduate student, over and beyond normal expectation.
Alyssa Hartmann (Rouge)
Bobbitt-Chou Graduate Summer Research Fellowship: This is a fellowship to recognize early accomplishment in a student’s graduate studies and the promise of continued success. One student entering their third summer of research will be awarded a $3,500 fellowship. The fellowship will be awarded based on course grades and a letter from the primary research advisor. The letter should specifically address the technical abilities of the student and his/her conceptual ownership and creative contributions to the research project. 
Matthew Guberman-Pfeffer (Gascon)

Synthesizing Pure Graphene, a ‘Miracle Material’

By Jessica McBride, Office of the Vice President for Research

Douglas Adamson, in the lab at the Institute of Materials Science on Aug. 23, 2017. (Peter Morenus/UConn Photo)

Formed deep within the earth, stronger than steel, and thinner than a human hair. These comparisons aren’t describing a new super hero. They’re describing graphene, a substance that some experts have called “the most amazing and versatile” known to mankind.

UConn chemistry professor Doug Adamson, a member of the Polymer Program in UConn’s Institute of Materials Science, has patented a one-of-a-kind process for exfoliating this wonder material in its pure (unoxidized) form, as well as manufacturing innovative graphene nanocomposites that have potential uses in a variety of applications.

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UConn Chemistry REU Symposium 2017

The Research Experience for Undergraduates (REU) Program, funded via the National Science Foundation, allows undergraduate students the opportunity to spend their summer conducting research at a REU host institution. Students spend approximately 10 weeks working closely on a research project with faculty members and graduate students. Students will also have the opportunity to utilize the research equipment and facilities specific to the host site.

To culminate their experience, the REU participants in chemistry presented their summer-long projects in a symposium on August 2, 2017. Click through the slideshow below to get a taste of what they accomplished!


Dr. Rebecca Quardokus Shares Her Passion For Microscopy

By Amanda Campanaro, IMS

There’s a special moment for most students when they discover what they really want to do with their major. For Rebecca Quardokus, Assistant Professor in Chemistry and associate faculty in IMS, that moment came as a junior at Grand Valley State University, Michigan, when her father sent her an article on Professor James Tour’s research at Rice University, Texas.

Dr. Quardokus, who had recently become a chemistry major, found the research fascinating. “His group had synthesized nano-sized cars with C60 fullerenes (buckyballs) for wheels, and they used scanning tunneling microscopy (STM) to image individual cars moving around on a gold surface,” Dr. Quardokus explains. “I was very excited to learn that STM, in addition to imaging, could manipulate individual atoms and molecules on the surface.” It was then she decided to attend graduate school to work with and master that “amazing technique.”

Now, Dr. Quardokus focuses her research on the engineering and reliability of molecular networks and two-dimensional materials for next-generation electronic devices. Her passion for learning STM has led her to begin a project working on developing new two-dimensional materials using surface-confined polymerization reactions.

“I use scanning tunneling microscopy, with its ability to measure individual atoms and molecules, to study the reactants and products,” she says.  “I will also study the charge and thermal transport properties of these materials.” Her group is hoping to tune specific properties for use in next-generation electronics.

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