Seminar

Dr. Joseph Pignatello

Our next Chemistry Seminar Speaker of our Spring Series is Dr. Joseph J. Pignatello, Chief Scientist at The Connecticut Agricultural Experimental Station. Dr. Pignatello will be speaking on “Interactions of organic compounds with natural and human-made pyrogenic carbonaceous materials—sorption, reaction, and catalysis.” His seminar will start at 3:00 pm, Friday, February 19th, via Zoom.

Abstract: Pyrogenic carbonaceous materials (PCM) are solid products of pyrolysis or thermolysis of biomass. Chars from wildfires, crop residue burning, or land clearing practices are widely distributed in the environment, and may influence soil structure, microbial activity, and behavior of pollutants especially in highly impacted areas. Produced PCMs such as activated carbon, biochar, and related materials, are in use or under study as agents in water, soil, and air purification, and as additives to improve soil properties. Central to the behavior of PCMs is their role as adsorbents; however, PCMs and their physico-chemically modified forms, are attracting interest as electron-transfer mediators and catalyst substrates. This lecture will describe our recent efforts in understanding and manipulating sorptive functions, probing the inherent chemical reactivity of PCMs and their ability to mediate electron-transfer reactions, and the modification of PCMs for specific environmental remediation functions.

Bio: Dr. Pignatello has been a pioneer in Environmental Science, and currently is Chief Scientist at The Connecticut Agricultural Experimental Station There, he leads the Environmental Chemistry Group, which researches both fundamental and applied aspects of the environmental chemistry of pollutants and natural processes, such as physical-chemical processes for removing or degrading pollutants in soil, water and air, physical-chemical interactions of organic compounds with soils and soil components, and bioavailability of organic contaminants in natural particles. A recent research focus is studying the nature of the interactions between organic compounds and pyrogenic carbon, including studies of novel interactions between the carbons and behaviors, tailoring the carbon surfaces to adsorb and transform contaminants, and potential roles for these carbons in environmental management.

Seminar

Dr. Weihua Zhou

Michigan Technological University’s College of Computing Assistant Professor Weihua Zhou is our second Chemistry Seminar Speaker of the semester!

Dr. Zhou will be presenting “Artificial intelligence for medical image analysis: our approaches” on Friday, February 12th, at 3:00 pm via Zoom.

Abstract: Machine learning (ML) has shown great advantages to overcome the challenges of high-dimensional complexity and inter-correlation among clinical predictors and help physicians make patient-specific clinical decisions related to diagnosis and treatment. Deep learning as a type of more complicated ML methods has been extensively used to extract information from medical records and images, and predict outcomes with a very high accuracy. Convolutional neural networks (CNN) are state-of-the-art deep learning techniques for computer vision, such as medical image segmentation and classification. This research talk will introduce our approaches of applying these artificial intelligence (AI) techniques to medical image analysis, particularly on image segmentation. We will also give an example about building a clinically accurate and practical AI-based software toolkit to improve percutaneous coronary intervention (PCI) for the treatment of patients with coronary artery disease.

Bio: Dr. Weihua Zhou, is an Assistant Professor of Applied Computing at Michigan Tech. He has been doing research on medical imaging and informatics since 2008. Prior to joining Michigan Tech, he was a post-doctoral fellow at Emory University School of Medicine from 2012 to 2015 and was an Assistant Professor of Computer Science at The University of Southern Mississippi from 2015 to 2019. Dr. Zhou’s research is driven by clinical significance. His research record includes more than 70 publications, 1 active patent, and 7 invention disclosures. His software applications are being used by 3 clinical trials and more than 30 hospitals.

Seminar

Our Spring Chemistry Seminar Series starts today! Dr. Ana de Bettencourt-Dias, a Susan Magee and Gary Clemons Professor of Chemistry from the University of Nevada, Reno, kicks off the series.

Her piece on Lanthanide Complexes with Dual Activity and Unusual Coordination Chemistry starts today at 3:00 pm, via zoom.

Abstract: The luminescence of lanthanide ions is based on f-f transitions. Due to the core nature of the 4f orbitals involved in the process, as well as the forbidden nature of these transitions, the emission properties make these ions uniquely suited for a variety of applications involving light emission, such as lighting,  imaging, and sensing. Since the f-f transitions are forbidden, the emission is most efficiently promoted through coordinated chromophores. The use of these coordinated ligands provides unique opportunities.  They can be functionalized to tailor the chemical and photophysical properties of the resulting complexes.1 We have used this approach to synthesize complexes that can be used as imaging agents for cancer cells.2 By extending the conjugation of the ligand we shifted the excitation wavelengths into the visible and isolated complexes that can be used as molecular nanothermometers.3In addition, we used carbazole-based ligands that enabled excitation of the resulting complexes in the biological window by a two-photon process. Finally, we used oligothiophene-based ligands to isolate complexes that luminesce and generate singlet oxygen.  
In this presentation, I will discuss my group’s recent work on lanthanide ion complexes with dual activity, as well as some recent results on unusual coordination chemistry4-5 of these fascinating metal ions. 

Figure 1. Temperature-dependent emission spectrum of K3[Tb(dipicCbz)3]. Inset shows the intensity of the 5D4 → 7F5 transition as a function of temperature.
Figure 1. Temperature-dependent emission spectrum of K3[Tb(dipicCbz)3]. Inset shows the intensity of the 5D4 → 7F5 transition as a function of temperature.3

References 

  1. Luminescence of Lanthanide Ions in Coordination Compounds and Nanomaterials. de Bettencourt-Dias, A.,  Ed. John Wiley and Sons: 2014. 
  2. Monteiro, J. H. S. K.; Machado, D.; de Hollanda, L. M.; Lancellotti, M.; Sigoli, F. A.; de Bettencourt-Dias,  A., Selective Cytotoxicity and Luminescence Imaging of Cancer Cells with A Dipicolinato-based EuIII Complex  Chem. Commun. 2017, 53, 11818-11821. 
  3. Monteiro, J. H. S. K.; Sigoli, F. A.; de Bettencourt-Dias, A., A Water-soluble TbIII complex as temperature sensitive luminescent probe. Can. J. Chem. 2018, 96, 859-864. 
  4. de Bettencourt-Dias, A.; Beeler, R. M.; Zimmerman, J. R., Anion-π and H-Bonding Interactions Supporting  Encapsulation of [Ln(NO3)6/5]3-/2-(Ln=Nd,Er) with a Triazine-based Ligand. J. Am. Chem. Soc. 2019, 141,  15102-15110. 
  5. de Bettencourt-Dias, A.; Beeler, R. M.; Zimmerman, J. R., Secondary-Sphere Chlorolanthanide(III)  Complexes with a 1,3,5-Triazine-Based Ligand Supported by Anion-π, π-π, and Hydrogen-Bonding  Interactions. Inorg. Chem. 2020, 59, 151-160.

Bio: Ana de Bettencourt-Dias received her ‘licenciatura’ (MS equivalent) in Technological Chemistry from the University of Lisbon in 1993, and her ‘Dr. rer. nat.’ (PhD equivalent) in Inorganic Chemistry from the University of Cologne in 1997 with Prof. Thomas Kruck. In her graduate work, she isolated new titanium complexes as single source precursors for the chemical vapor deposition of TiN thin layers. She joined the group of Prof. Alan Balch at UC Davis in 1998 as a Gulbenkian postdoctoral fellow, where she studied the electrochemistry and structure of fullerenes and endohedral fullerenes. In 2001 she joined the faculty at Syracuse University and started her work on luminescent lanthanide ion complexes. She moved to the University of Nevada, Reno, as associate professor in 2007 and was promoted to professor in 2013. Her research centers on light-emitting compounds and coordination chemistry of the f block of the periodic table. She served on the editorial advisory board for Inorg. Chem. from 2013 to 2015, and has been a managing member of the editorial board of the Journal of Rare Earths since 2014.  She was program chair of the 2011 and conference chair of the 2014 Rare Earth Research Conference, organizes the lanthanides and actinides symposia at the national meetings of the American Chemical Society and was the 2019 Chair of the Division of Inorganic Chemistry of the American Chemical Society. She served as the Associate Vice President for Research at UNR from 2015 to 2019. She returned to being a full-time faculty in July 2019, and is now the Susan Magee & Gary Clemons Professor of Chemistry.

In Print

Christo Z Christov (Chem), chemistry PhD candidate Shobhit Chaturvedi, Rajeev Ramanan, a postdoctoral scholar currently at NIT Rourkela (India), Jian Hu (Michigan State University) and Robert Hausinger (Michigan State University) published an article entitled: “Atomic and Electronic Structure Determinants Distinguish between Ethylene Formation and L-Arginine Hydroxylation Reaction Mechanisms in the Ethylene-Forming Enzyme,” in ACS CATALYSIS. Their article reveals the unique mechanism of the non-heme Fe (II)- and 2-Oxoglutarate (2OG)-dependent Ethylene-Forming Enzyme (EFE).

The study reveals that unique structural rearrangement triggers the splitting of the 2OG co-substrate that leads to the formation of ethylene in EFE in competition of a standard hydroxylation reaction. The study provides a background for increased enzymatic production of ethylene. The research is supported by NSF grants 1904215 and 1904295.

Seminar

We welcome Dr. Christine Chow as our last seminar speaker of the fall semester. Dr. Chow will present her piece on Tools for Monitoring RNA Modifications and Drug Interactions at 3:00 p.m. Friday, via Zoom.

Abstract: Among different RNA modifications, the helix 69 (H69) region of the bacterial ribosomal RNA (rRNA) contains three pseudouridines (Ψs). H69 is functionally important due to its location in the heart of the ribosome. Several structural and functional studies have shown the importance of Ψ modifications in influencing the H69 conformation as well as maintaining key interactions in the ribosome during protein synthesis. Therefore, a need exists to understand the influence of modified nucleosides on conformational dynamics of the ribosome under solution conditions that mimic the cellular environment. We have used a variety of methods including fluorescence spectroscopy and chemical probing with dimethyl sulfate (DMS) to examine H69 conformational states and the influence of Ψ modifications under varying solution conditions in the context of model RNAs, ribosomal subunits, and full ribosomes. The use of DMS footprinting, electrospray ionization mass spectrometry, and fluorescence spectroscopy to study the binding of aminoglycosides to H69 as well as helix 44 of bacterial rRNA as antibiotic targets will also be discussed. As highlighted in our work, DMS probing and footprinting are versatile techniques that can be used to gain important insight into RNA local structure and RNA-drug interactions.

Bio: My group studies large RNAs in order to better understand the impacts of modifications, determine how drugs locate their preferred binding sites, and identify new drug target sites. We use a combination of synthetic, biochemical, bioinorganic, and biophysical techniques, including modified oligonucleotide synthesis, chemical modification of RNA and primer extension assays, phage display, mass spectrometry, and circular dichroism, fluorescence, and NMR spectroscopies. I have a broad background in nucleic acid chemistry, with specific expertise in modified ribosomal RNAs and small molecule-RNA interactions. To help prepare students for professional success after graduate school, I have been involved with the NIH-supported WSU Broadening Experiences in Scientific Training program (BEST, co-PI from 2013-2018 and PI2018-2019). My role was to develop seminar and workshop content for 7 different modules in business, communication, community engagement, government, law, research administration, and teaching), which involved two-hour seminars and all-day workshops with alumni, business partners, and experts in the various career tracks. I also initiated the “Mini-BEST” program at Wayne State, in which faculty in departments, centers, and cross-disciplinary programs across the campus were given guidance on how to establish their own career development events (funded by the Wayne State Graduate School).  The BEST program has served more than 1000 students at Wayne State University since 2013. In 2012, I helped develop and run a campus-wide “Fellowship Writing Bootcamp”, which guided graduate students and postdocs in preparing F31/F32 applications (2012–2017). The workshop included mock study panels and recruitment of faculty to serve as reviewers of the proposals prior to submission. I also initiated the use of mock study section panels for faculty across three colleges (Liberal Arts & Sciences, Engineering, and School of Medicine).

Job Opening

The Chemistry Department is looking for a Research and Communications Facilitator. This position is outward-facing, representing, and promoting the department to external constituencies. The person will act as a department liaison in supporting the Chair with other units on campus (e.g. Research Development, Federal Relations & Corporate Research, Sponsored Programs, Alumni Relations, and University Marketing and Communication Services).

Seminar

Chemistry welcomes Dr. Sangyoon Han from the Biomedical Engineering Department as our seminar speaker this Friday (November 13th). The virtual seminar will be held via Zoom at 3:00 PM. The passcode is 859189 if needed.

Toward Discovery of the Initial Stiffness-Sensing Mechanism by Adherent Cells

Abstract: The stiffness of the extracellular matrix (ECM) determines nearly every aspect of cellular/tissue development and contributes to metastasis of cancer. Adherent cells’ stiffness-sensing of the ECM triggers intracellular signaling that can affect proliferation, differentiation, and migration of the cells. However, biomechanical and molecular mechanisms behind this stiffness sensing have been largely unclear. One critical early event during the stiff-sensing is believed to be a force transmission through integrin-based adhesions, changing the molecular conformation of the molecules comprising the adhesions that link the ECM to the cytoskeleton. To understand this force transmission, my lab develops experimental and computational techniques, which include soft-gel-based substrates, live-cell imaging, computer-vision-based analysis, and inverse mechanics, etc. In this talk, I will talk about how we use soft-gel to quantify the spatial distribution of mechanical force transmitted by a cell, how we use light microscopy and computer vision to analyze the focal adhesions, and how these techniques are related to stiffness sensing. In particular, I will show you new data where cells can transmit different levels of traction forces in response to varying stiffness, even when the activity of the major motor protein, myosin, is inhibited. At the end of the talk, potential molecules responsible for the differential transmission will be discussed.

Bio: Sangyoon Han received his Ph.D. in Mechanical Engineering at the University of Washington (UW) in 2012 and did postdoctoral training with Dr. Gaudenz Danuser in the Department of Cell Biology at Harvard Medical School and the University of Texas Southwestern Medical Center for five years until 2017. Before the Ph.D., he received B.S and M.S. degree from Mechanical Engineering at Seoul National University, Seoul, Korea in 2002 and 2004. He joined Michigan Tech, Biomedical Engineering from this fall, 2017, and started Mechanobiology Laboratory. His lab’s interests are in understanding the dynamic nature of force modulation occurring across cell adhesions and cytoskeleton that regulate cells’ environmental sensing. His lab develops a minimally-perturbing experimental approach and computational techniques, including soft-gel fabrication, nano-mechanical tools, live-cell microscopy, and image data modeling, to capture the coupling between force modulation and cellular molecular dynamics.

Seminar

Dr. Karana Shah, Vice President of Technology at Dixie Chemical Company will be speaking this Friday, November 6th, 2020 at 3:00 p.m., via Zoom.

How to Get Hired and Progress in an Industrial Career from the Perspective of a PhD Graduate

Abstract: From R&D scientist to technical marketing to company leadership, Karana Shah has had an interesting career in industry since receiving her PhD from MSU in 2006. Taking a leap from academia to industry can be a decision fraught with worry. Graduate students and postdocs can have a tough time framing their extensive technical training into tangible skills that employers are looking for. Job seekers at all levels want to figure out if a position will be a good fit, with a company that will support future growth and professional development. Karana will describe some of the steps she took to find her first role out of graduate school and offer suggestions to those just starting out. She has successfully moved between positions and companies several times and will describe learnings from that process. At her current company, she has taken on increased responsibility with a promotion to a senior leadership role. A solid foundation with BS (2000) and MS (2002) degrees from MTU Chemistry helped lay the groundwork for the path she is on today.

BIO: Dr. Karana Shah joined Dixie Chemical in 2013 as Technical Services Manager and was promoted to VP of Technology in 2016. Prior to joining Dixie, she worked for Zoltek (now part of Toray Group), a global manufacturer of carbon fiber. At Zoltek, she supported the Composite Intermediates product line including pultruded profiles and prepreg. Karana also previously worked for Evonik Jayhawk Fine Chemicals as Technical Service Marketing Manager for Specialty Anhydrides and for TAMKO Building Products as a Research and Development Engineer for thermoplastic composite products. Dr. Shah earned her BS and MS degrees in Chemistry from Michigan Technological University in Houghton, MI. Her MS degree was completed under the guidance of Dr. Patricia Heiden in 2002. She also earned her Ph.D. in polymer composites with advisor Dr. Laurent Matuana from the Department of Forestry at Michigan State University, East Lansing, MI in 2006.