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The Nicewicz Group

The Nicewicz Group

Research in the Nicewicz Group focuses on developing new catalysts and methods for organic synthesis. In particular, our group seeks to harness the power of photoinduced electron transfer processes to drive the development of new asymmetric bond forming reactions. Additionally, we seek to apply these new reactions to the synthesis of biologically-active, complex natural products.

 

Undergraduate Research

Undergraduate Research

An undergraduate research project is an exciting and rewarding experience. Undergraduate research can help you acquire a spirit of inquiry, initiative, independence, sound judgment, patience, persistence, alertness, and the ability to use the chemical literature. The Department strongly endorses undergraduate research as one of the potentially most rewarding aspects of your undergraduate experience.

Although successful completion of an undergraduate research project is a requirement for graduation with Honors or Highest Honors, it is not necessary to be a participant in the honors program to undertake a research project. Visit the Office for Undegraduate Research to learn where "your curiosity can lead you."

 

Hicks Young Investigator Award Winner

Professor Hicks

Assistant Professor Leslie Hicks has been awarded the Arthur C. Neish Young Investigator Award. These awards are given each year by the Phytochemical Society of North America to outstanding early career scientists. The young investigator chosen will present their research at the annual meeting as part of the Arthur C. Neish Young Investigator Mini-symposium. Leslie made her presentation earlier this month at the 53rd Annual Meeting in Raleigh. Congratulations, Leslie!

 

Nitric Oxide-Releasing Glucose Biosensors

In vivo glucose biosensors have the potential to greatly improve the way diabetics manage their disease. Unfortunately, such devices do not function as intended, that is, reliably, after implantation due to inflammation and encapsulation due to the "foreign body response.” The Schoenfisch Group has for the last decade researched the benefits of materials that release nitric oxide, NO, to mitigate the foreign body response. In an article published in Analytical Chemistry, they describe the analytical performance benefits of a NO-releasing glucose biosensor percutaneously implanted in a swine model.

Research Image

Needle-type glucose biosensors were modified with NO-releasing polyurethane coatings designed to release similar total amounts of NO for either rapid or slower durations, and remain functional as outer glucose sensor membranes. Relative to controls, NO-releasing sensors were characterized with improved numerical accuracy on days one and three.

The clinical accuracy and sensitivity of rapid NO-releasing sensors were superior to control and slower NO-releasing sensors at both one and three days after implantation. In contrast, the slower/extended NO-releasing sensors were characterized by shorter sensor lag times in response to intravenous glucose tolerance tests versus burst NO-releasing and control sensors. Collectively, these results highlight the great potential for NO release to enhance the analytical utility of in vivo glucose biosensors. Initial results also suggest that this analytical performance benefit is dependent on the NO-release duration.

 

Prize-Winning Scientific Art

Maria Ina and Aleksandr Zhushma in the Sheiko Group, won second place in the sixth annual CHANL Scientific Art Competition with their “Snowflake Robe,” a fractal-like spot captured with an electron microscope. "Initially, I was imaging some particles, when I came across this interesting pattern on the surface," says Aleksandr. Maria and Aleksandr realized that it could be art-worthy, so they took a high resolution image of the feature. They believe this is some soapy material that came off the particles and dried on the surface.

Snowflake Robe

The original SEM image is black and white, so they colorized the image using ImageJ. Lightroom was then used for post processing to fine-tune color and contrast. In naming the image, the snowflake pattern was obvious, but the background waviness was open for interpretation. "So I imagined that it is a flowing robe, with the snowflake pattern on it," says Aleksandr.

The Chapel Hill Analytical and Nanofabrication Laboratory (CHANL) was established in 2006 as part of the Institute for Advanced Materials, Nanoscience and Technology, but has since moved into the Department of Applied Physical Sciences. CHANL operates as a shared instrumentation laboratory open to UNC researchers from all departments as well as to researchers from other universities, government labs, and industry.

 

Cerebral Blood Flow

Neurovascular coupling is understood to be the underlying mechanism of functional hyperemia, but the actions of the neurotransmitters involved are not well characterized. In an article published in the Journal of Cerebral Blood Flow & Metabolism, researchers in the Wightman Group investigate the local role of the neurotransmitter norepinephrine in the ventral bed nucleus of the stria terminalis, vBNST, of an anesthetized rat by measuring O2, which is delivered during functional hyperemia. Extracellular changes in norepinephrine and O2 were simultaneously monitored using fast-scan cyclic voltammetry. Introduction of norepinephrine by electrical stimulation of the ventral noradrenergic bundle or by iontophoretic ejection induced an initial increase in O2 levels followed by a brief dip below baseline.

Research Image

Supporting the role of a hyperemic response, the O2 increases were absent in a brain slice containing the vBNST. Administration of selective pharmacological agents demonstrated that both phases of this response involve β-adrenoceptor activation, where the delayed decrease in O2 is sensitive to both α- and β-receptor subtypes. Selective lesioning of the locus coeruleus with the neurotoxin DSP-4 confirmed that these responses are caused by the noradrenergic cells originating in the nucleus of the solitary tract and A1 cell groups. Overall, these results support that non-coerulean norepinephrine release can mediate activity-induced O2 influx in a deep brain region.

 

Trifluormethyl Pyrrolidines

Researchers in the Johnson Group, published in Organic Letters, describe the stereoselective synthesis of trisubstituted 2-trifluoromethyl pyrrolidines by asymmetric Michael addition/hydrogenative cyclization.

Research Image

The direct organocatalytic addition of 1,1,1-trifluoromethylketones to nitroolefins proceeds under mild reaction conditions and low catalyst loadings to provide Michael adducts in high yield with excellent diastereo- and enantioselectivity. Catalytic hydrogenation of the Michael adducts stereoselectively generates 2-trifluoromethylated pyrrolidines bearing three contiguous stereocenters. The group members also describe a stereospecific route to epimeric 2-trifluoromethyl pyrrolidines from a common intermediate.

 

UNC EFRC Funding Renewed

The Energy Frontier Research Center for Solar Fuels (EFRC) at the University of North Carolina at Chapel Hill, led by led by Thomas J. Meyer, Arey Professor of Chemistry, received $10.8 million from the U.S. Department of Energy, Office of Basic Energy Sciences, to advance emerging solar energy technologies and to turn these technologies into devices that can efficiently produce fuels.

EFRC Renewal

“We are delighted with the news of continued support by the Department of Energy for our leading edge research on a new approach to solar energy conversion and storage,” said Meyer. “Continued funding will allow us to move ahead in this important area with the twin goals of mastering the basic science behind the dye sensitized photoelectrosynthesis cell and applying it to water splitting into hydrogen fuel and oxygen and in reducing carbon dioxide to useful carbon fuels.”

 

 

At the Department of Chemistry, we feel strongly that diversity is crucial to our pursuit of academic excellence, and we are deeply committed to creating a diverse and inclusive community. We support UNC's policy, which states that "the University of North Carolina at Chapel Hill is committed to equality of opportunity and pledges that it will not practice or permit discrimination in employment on the basis of race, color, gender, national origin, age, religion, creed, disability, veteran's status, sexual orientation, gender identity or gender expression."