Tag Archive for Chemistry

King Coauthors Paper and Is Elected to Chair Research Seminar on Noble Metal Nanoparticles

Melissa King

Melissa King, a PhD student in chemistry, and Michelle Personick, assistant professor of chemistry, are the coauthors of a study titled “Iodide-induced differential control of metal ion reduction rates: synthesis of terraced palladium–copper nanoparticles with dilute bimetallic surfaces,” published in Journal of Materials Chemistry A, August 2018.

In this paper, King and Personick report the use of low concentrations of iodide ions as a means of differentially controlling the reduction rates of a noble metal (palladium) and a non-noble metal (copper). The iodide in this system increases the rate of reduction of palladium ions while concurrently slowing the rate of copper ion reduction, thus providing a degree of control that is not achievable using most other reported means.

In addition, last June, King presented a talk as part of the Gordon Research Seminar on Noble Metal Nanoparticles, a graduate/postdoc meeting that takes place the day before the corresponding Gordon Research Conference. She also was elected to chair the next Gordon Research Seminar on Noble Metal Nanoparticles in two years. King also received an award for her poster at the Gordon Research Conference and gave a 10-minute poster award talk to the Gordon Research Conference audience. With the exception of the poster award talks, all presentations at the Conference portion were invited talks given by faculty.

Personick Honored with Young Investigator Program Award from Army Research Office

Michelle Personick joined the faculty this fall, and is teaching courses in Chemistry of Materials and Nanomaterials and an Integrated Chemistry Lab. (Photo by Olivia Drake)

Michelle Personick

Michelle Personick, assistant professor of chemistry, is the recipient of a three-year, $339,000 Young Investigator Program grant funded by the U.S. Army Research Office. Personick will use the funds to support her nanoparticle research, which ultimately may protect military soldiers from hazardous chemicals and materials.

The Army’s Young Investigator Program is designed to identify and support talented scientists and engineers who show exceptional promise for doing creative research, in order to encourage their teaching and research careers. The program is open to U.S. citizens, Nationals, and resident aliens holding tenure-track positions at U.S. universities and colleges, who have held their graduate degrees for fewer than five years at the time of application.

Dombrowski, Saaka, Taylor Receive Binswanger Prizes for Excellence in Teaching

President Michael Roth with Binswanger Prize for Excellence in Teaching honorees Lisa Dombrowski ’92 and Erika Taylor. Honoree Iddrisu Saaka is not pictured.

During Wesleyan’s 186th commencement ceremony on May 27, Wesleyan presented outstanding teachers with the Binswanger Prize for Excellence in Teaching. These prizes, made possible by gifts from the family of the late Frank G. Binswanger Sr., Hon. ’85, underscore Wesleyan’s commitment to its scholar-teachers, who are responsible for the University’s distinctive approach to liberal arts education.

Recommendations are solicited from alumni of the last 10 graduating classes, as well as current juniors, seniors, and graduate students. Recipients are chosen by a selection committee of faculty and members of the Alumni Association Executive Committee.

This year, Wesleyan honored the following faculty members for their excellence in teaching:

Lisa Dombrowski
Lisa Dombrowski ’92, associate professor of film studies, has been a member of Wesleyan’s faculty since 2001. She teaches in the College of Film and the Moving Image and is a core member of the College of East Asian Studies. She earned her BA in film studies and American studies at Wesleyan in 1992 and went on to receive an MA and PhD in film studies from the University of Wisconsin–Madison. Dombrowski is the author of The Films of Samuel Fuller: If You Die, I’ll Kill You! and the editor of Kazan Revisited. She has written for The New York Times, Film Comment, Film Quarterly, Film History, and the Criterion Collection, among others. Her research is concerned with the art and business of cinema, especially post-WWII film form and modes of production. Her teaching focuses on film history, the industry, and aesthetics in international art cinema, East Asian cinema, American independent cinema, and melodrama and the woman’s picture. Dombrowski is currently completing a book on director, screenwriter, and producer Robert Altman and American independent cinema in the 1990s and 2000s.

Iddrisu Saaka

Iddrisu Saaka (Photo by Perceptions Photography)

Iddrisu Saaka (unable to attend the ceremony)
Iddrisu “Iddi” Saaka, artist-in-residence in dance, has taught at Wesleyan since 2008. He earned a diploma in dance from the University of Ghana and an MFA in dance from UCLA. A dancer, dance teacher, and choreographer from Ghana, West Africa, Saaka has choreographed and performed at the World Festival of Sacred Music, the International Festival of Masks, the Skirball Center, Royce Hall, the Fowler Museum, Dance Arts Academy, Debbie Allen Dance Academy, El Portal Forum Theatre, and the Music Center in Los Angeles. At Wesleyan, he teaches courses in West African dance and also directs the West African Drumming and Dance Concert at the end of each semester. He has served as a visiting instructor of dance at UCLA, University of California San Diego, and the University of Ghana.

Erika Taylor
Erika Taylor, associate professor of chemistry, environmental studies, and integrative sciences, joined the Wesleyan faculty in 2007. She holds a BS in chemistry with honors from the University of Michigan at Ann Arbor and a PhD in chemistry from the University of Illinois at Urbana-Champaign. She was also a postdoctoral research associate at Albert Einstein College of Medicine. Throughout her career, Taylor has worked at the interface of chemistry and biology where she strives to find ways to exploit enzymes found in nature to perform chemistry that can help advance the fields of chemistry and medicine. She also employs chemical synthesis to help answer questions of both biological and medical interest. At Wesleyan, her research has focused on the identification and characterization of enzymes that are important for the development of antimicrobials for the treatment of Gram-negative bacterial infections—particularly bacteria that cause foodborne illnesses, such as E. coli and V. cholerae. She also studies enzymes that can improve the efficiency of biomass to biofuel conversion, particularly the breakdown and bacterial utilization of lignin. She teaches courses in the areas of organic chemistry, biochemistry, environmental chemistry, and biomedicinal chemistry, among others.

View previous Binswanger recipients online here.

Students Inducted into Honor Society, Present Research at American Society for Biochemistry and Molecular Biology Meeting

Undergraduates from the Biology, Chemistry, and Molecular Biology and Biochemistry majors showed off their science at the 2018 meeting of the American Society for Biochemistry and Molecular Biology. From Left, Alex Shames '18 (MacQueen Lab), BA/MA student Arden Feil (MacQueen Lab), Will Barr '18 (Weir Lab), Christine Little '18 (Mukerji Lab), Cody Hecht '18 (Taylor Lab), and Emily Kessler '18 (Hingorani Lab).

Undergraduates from the biology, chemistry, and molecular biology and biochemistry majors showed off their science at the 2018 meeting of the American Society for Biochemistry and Molecular Biology. From left, Alex Shames ’18 (MacQueen Lab), Arden Feil BA/MA ’18 (MacQueen Lab), Will Barr ’18 (Weir Lab), Christine Little ’18 (Mukerji Lab), Cody Hecht ’18 (Taylor Lab), and Emily Kessler ’18 (Hingorani Lab).

Seven Wesleyan students recently were inducted into the American Society for Biochemistry and Molecular Biology (ASBMB) Honor Society, and many of them presented research posters at the ASBMB annual meeting in San Diego, April 21–25.

The ASBMB Honor Society recognizes exceptional undergraduate juniors and seniors who are pursuing a degree in the molecular life sciences for their scholarly achievement, research accomplishments, and outreach activities. The Wesleyan students inducted were Will Barr ’18, Alexa Strauss ’19, Emily Kessler ’18, Christine Little ’18, Julie McDonald ’18, Rubye Peyser ’18, and Alexander Shames ’18.

The following students attended the annual meeting:

• Kessler, whose poster was titled, “Investigating the Mechanistic Basis of Mutant MutS DNA Repair Protein Malfunction in Lynch Syndrome”
• Barr, “An mRNA-rRNA base pairing model for efficient protein translation”
• Little, “Investigation into the Binding Interactions of Saccharomyces cerevisiae Histone H1 with Holliday Junction”
• Shames, “The Long and Short of Synaptonemal Complex Assembly: Investigating the genesis and functional relevance of a smaller Zip1 isoform”
• Cody Hecht ’18, “Escherichia coli Heptosyltransferase I: Examining Protein Dynamics with Pyrene Excimer Fluorescence and Tryptophan-Induced Quenching”
• Arden Feil BA/MA ’18, “Scraping the Tip of Zip1’s Role in Meiotic Chromosome Dynamics: Using lacO/LacI corecruitment to identify crossover promoting factors that interface with the N-terminus of a synaptonemal complex protein”

“It was a joy to present the research that I’ve been working on for the past two years as a part of Wesleyan’s Beckman Scholars Program,” said Barr. “Science research can seem like a roller coaster at times, and presenting my research in the company of scientists at all levels of their careers helped me remember just how thrilling this process has been.”

The mission of ASBMB is to advance the science of biochemistry and molecular biology through organization of scientific meetings, advocacy for funding of basic research and education, support of science education at all levels, promotion of the diversity of individuals entering the scientific workforce, and publication of a number of scientific and educational journals, including the Journal of Biological Chemistry and the Journal of Lipid Research.

Sundberg ’20 Lobbies for Immigration Policy as National Legislation Advocacy Corps Organizer

Kate Sundberg ’20

Kate Sundberg ’20

Chemistry and environmental studies major Kate Sundberg ’20, one of 20 students nationwide who are part of the Friends Committee on National Legislation Advocacy Corps, attended the Spring Lobby Weekend on March 17–20 advocating for immigration policy with Congress.

The Advocacy Corps is a yearlong program where young adults between the ages of 19–30 organize their local communities around federal legislation.

As an organizer, Sundberg connects local activists and leaders with Congress to affect meaningful, bipartisan climate action.

Taylor, Alumni, Students Co-Author 3 Journal Articles

Erika Taylor

Erika Taylor, associate professor of chemistry, is the recent co-author of three articles. Two publications are related to disrupting the formation of Lipopolysaccharides (LPSs), a cell surface component that is important to Gram-Negative bacteria’s ability to form biofilms and become resistant to hydrophobic antibiotics. These papers describe inhibition of enzymes from E. coli, as well as enzymes from related pathogens including Vibrio cholerae (the bacteria that causes cholera), and Yersinia pestis (the bacteria that causes plague). Understanding how enzymes can be inhibited opens up possible new strategies for fighting diseases.

The third paper builds on her prior work investigating the ways in which sucralose (an artificial sweetener known primarily as Splenda) interacts with proteins, in comparison with its natural disaccharide counterpart, sucrose (common table sugar). She and her co-authors present data showing that sucralose interacts more strongly with hydrophobic patches on protein surfaces than does sucrose, which may be part of the way in which it causes destabilization of proteins.

These papers include alumni authors Noreen Nkosana B.A. ’11, MA ’13, Daniel Czyzyk PhD ’15, Zarek Siegel BA ’16 and current student authors Joy Cote Chemistry PhD ’18, Nimesh Shukla Physics PhD ’18, Cody Hecht ’18, in addition to Taylor’s longtime collaborator, Christina Othon, associate professor of physics at Ripon College.

Taylor also is associate professor of environmental studies and of integrative sciences.

The papers are:

Synthesis, kinetics and inhibition of Escherichia coli Heptosyltransferase I by monosaccharide analogues of LipidA,” published in Bioorganic and Medicinal Chemistry Letters, 2018, in press.

The Glycosyltransferases of LPS Core: A Review of Four Heptosyltransferase Enzymes in Context,” published in the International Journal of Molecular Sciences, 2017, 18(11), 2256. This article belongs to the Special Issue Lipopolysaccharides.

Hydrophobic Interactions of Sucralose with Protein Structures,” published in the Archives of Biochemistry and Biophysics, 2017, 639, pages 38-43.

NSF Grant Supports Field-Emission Scanning Electron Microscope Purchase

Michelle Personick, assistant professor of chemistry, examines nanoparticles viewed from a new field emission scanning electron microscope.

Michelle Personick, assistant professor of chemistry, examines palladium nanoparticles viewed from a new field-emission scanning electron microscope.

The monitor on the left displays a backscattered electron image of a meteorite at 100x; the colored version, on the right and top monitor, is an elemental map of the same area of the sample. The new FE-SEM has the ability to magnify samples at up to 300,000x, whereas Wesleyan’s former SEM could only reliably magnify samples at 40,000x.

By using a newly acquired electron microscope, the E&ES 368 Meteorites and Cosmochemistry class was able to classify a meteorite discovered in Morocco.

“We were able to determine that it was an H4 ordinary chondrite, and the chemical information being collected today will be used to document these findings and submit this meteorite to the Meteorite Nomenclature Committee of the Meteoritical Society for official classification,” said class instructor Jim Greenwood, assistant professor of earth and environmental sciences.

On Feb. 8, several faculty, students and staff from Academic Affairs gathered in Exley Science Center to celebrate the arrival of the instrument and the opening of the newly-renovated lab that it is housed in. The lab is in the basement connector between Exley and Hall-Atwater.

On Feb. 8, several faculty, students and staff from Academic Affairs gathered in Exley Science Center to celebrate the arrival of the instrument and the opening of the newly renovated lab that it is housed in. The microscope is housed in the basement pathway between Hall-Atwater Laboratory and Shanklin and is part of the Advanced Instrumentation Center’s Scientific Imaging Laboratory.

Wesleyan acquired the field-emission scanning electron microscope (FE-SEM) with support from a $202,300 National Science Foundation grant awarded in August 2017. Greenwood and Michelle Personick, assistant professor of chemistry, applied for the grant through the NSF’s Major Research Instrumentation and Chemistry Research Instrumentation Programs. Wesleyan faculty Renee Sher, Martha Gilmore, Dana Royer, Ellen Thomas, Phil Resor, Suzanne O’Connell, Tim Ku, Johan “Joop” Varekamp and Ruth Johnson also contributed to the grant application.

“The SEM is a versatile tool that enables researchers to simultaneously obtain a wealth of different information about a sample, including topography, composition and fine structure,” Personick said. “At Wesleyan, the research enabled by the microscope addresses broad-ranging fundamental questions with significant societal relevance, including the sustainable production of chemicals and energy, the origin of the Earth’s oceans, and the relationship between atmospheric carbon dioxide levels and temperature in ancient environments.”

Knee Co-Authors Article on Hydrogen-Bonding Interactions

Joseph Knee, the Beach Professor of Chemistry and Dean of the Natural Sciences and Mathematics Division, is the author of a new article published in the journal Physical Chemistry Chemical Physics (PCCP). This “Perspectives” article, which was commissioned by the PCCP editorial board and editorial office, is a high-profile look at work by Knee and his collaborators that has been going on for nearly a decade. Perspectives articles are intended to present an authoritative state-of-the-art account of a particular research field.

The research by Knee and his collaborators, which is ongoing, uses experimental and computational methods to explore hydrogen bonding interactions, which are extremely important in the structure of water, various solutions, and in many key biochemical structures and processes.

Knee explains, “The most important aspect of our methodology is making careful experimental measurements of two single molecules forming hydrogen bonds and then modeling these bonds with modern quantum chemical calculations. The calculations allow us to decompose the various forces which contribute to the bond strength and structure. The larger goal is to generalizing this insight to more complex hydrogen bonded systems, particularly hydrogen bonding networks which exist in liquids and biological systems.”

The full article can be read here by those with subscriptions or institutional subscriptions, including those on Wesleyan’s campus.

Faculty Spotlight: Michelle Personick

Michelle Personick joined the faculty this fall, and is teaching courses in Chemistry of Materials and Nanomaterials and an Integrated Chemistry Lab. (Photo by Olivia Drake)

Michelle Personick, assistant professor of chemistry, assistant professor of integrative sciences, is an advocate for Wesleyan Women in Science (WesWIS). “The more women (and underrepresented minorities) who pursue careers in the sciences, the more younger female and underrepresented students will be able to imagine themselves in those roles, and the sciences will begin to diversify,” she said. (Photo by Olivia Drake)

In this Q&A, we speak with Michelle Personick, assistant professor of chemistry, assistant professor of integrative sciences. Personick, who joined the faculty at Wesleyan in 2015, is interested in developing tailored metal nanomaterials that improve the clean production of energy and enable the efficient use of energy resources. Her work has recently been published in the journals Particle and Particle Systems Characterization and American Chemical Society Catalysis.

Q: Professor Personick, how would you describe your main research interests?

A: The main research areas in my group are controlling the shape and composition of noble metal nanocrystals, and exploring the use of these nanoparticles as catalysts to improve the efficiency and selectivity of reactions that are important in chemical industry and in energy production.

When she's not teaching or working in the lab, Michelle Personick, at right, rows crew with the Riverfront Recapture masters racing team in Hartford.

When she’s not teaching or working in the lab, Michelle Personick, at right, rows with the Riverfront Recapture masters racing team in Hartford, Conn.

Q: When did you develop an interest in chemistry?

A: I’ve always been interested in science in general, but it was more a broader interest than a specific focus on chemistry. There was actually a period of time in high school when I wanted to be a particle physicist. I chose chemistry after writing an essay about a cool new light-controlled nanoparticle cancer treatment for a class my senior year in high school.

Q: What attracted you to Wesleyan and how has your experience been here over the last couple years?

A: I had a really positive small liberal arts college experience at Middlebury, where most of my professors knew who I was and cared about how I was doing in their class. Once I decided I wanted to be a professor, I knew that was the type of environment I wanted. In the different courses I’ve taught in my first two years, I’ve found the atmosphere at Wesleyan to be well-matched to pursuing that kind of teaching philosophy. What attracted me to Wesleyan specifically are the unique research opportunities that come out of having a small, but strong, graduate program in addition to being a top-tier undergraduate institution. The advanced research instrumentation here at Wesleyan, such as the electron microscopy facility, is also crucial to our ability to successfully carry out our research. I’d always wanted to work primarily with undergraduates once I set up my own research lab, but having even just two graduate students in that lab as well makes an enormous difference in the level of research I’m able to carry out. In turn, that creates an environment in which the very talented undergraduates I’ve had in my group so far have the opportunity to work on independent projects that get published in peer-reviewed journals and that are well-received by other scientists at major conferences. It’s been very rewarding over the last two years to get our lab up and running and to begin to see the results of the hard work put in by all of my research students, undergraduate and graduate.

Plasma Bubble, Stem Cell Images Win Scientific Imaging Contest

This summer, Wesleyan hosted the second annual Wesleyan Scientific Imaging Contest, which recognizes student-submitted images from experiments or simulations done with a Wesleyan faculty member that are scientifically intriguing as well as aesthetically pleasing. This year, 33 images were submitted from six departments.

The entries were judged based on the quality of the image and the explanation of the underlying science.  The images were judged by a panel of four faculty members: Steven Devoto, professor of biology, professor of neuroscience and behavior; Ruth Johnson, assistant professor of biology, assistant professor of integrative sciences; Brian Northrop, assistant professor of chemistry, assistant professor of integrative sciences; and Candice Etson, assistant professor of physics.

The first-place winner received a $200 prize; the second-place winner received $100; and the third-place winner received $50. Prizes were funded by the Office of Academic Affairs.

The three winning images are shown below, along with scientific descriptions, written by the students.

Yonathan Gomez '18 won first place with his image, "Jumping" Drop. The drop is an expanding partially-ionized plasma created underwater by a pulsed Nd:YAG laser, which pushes upwards on the surface of the water. As the plasma bubble expands, it disrupts the surface from below, which launches a water drop upward. The water drop shown has a diameter of approximately 2mm. The image was taken at 1/2,000 frames per second.

Yonathan Gomez ’18 won first place with his image, “Jumping” Drop. The drop is an expanding partially-ionized plasma created underwater by a pulsed Nd:YAG laser, which pushes upwards on the surface of the water. As the plasma bubble expands, it disrupts the surface from below, which launches a water drop upward. The water drop shown has a diameter of approximately 2mm. The image was taken at 1/2,000 of a second.

Research Paper by Personick, King Published in ‘Particle’ Journal

Michelle Personick, assistant professor of chemistry, and her graduate student Melissa King, are co-authors of a paper titled “Bimetallic Nanoparticles with Exotic Facet Structures via Iodide-Assisted Reduction of Palladium,” published in the journal Particle and Particle Systems Characterization, Vol. 34, Issue 5, in May 2017. The research was featured on the inside front cover of the issue.

In this study, Personick and King explain how gold–palladium tetradecapods (14-pointed nanoparticles) with an unusual combination of both well-defined concave and convex facets can be synthesized by introducing dilute concentrations of iodide during nanoparticle growth. Iodide directs the formation of the tetradecapods by increasing the rate of palladium ion reduction, which is a new role for this shape-controlling additive.

This article also was recently highlighted in Advanced Science News.