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Several technologies have been developed to produce hydrocarbon biofuels – renewable diesel (RD) and sustainable aviation fuel (SAF) – from fats, oils, and greases (FOG), with the hydroprocessing of esters and fatty acids (HEFA) representing one of the most mature pathways. In its current form, HEFA is mainly reliant on the hydrodeoxygenation (HDO) reaction, which has several drawbacks since HDO requires large amounts and pressures of hydrogen, feedstocks of high purity and cost, as well as problematic sulfided catalysts that risk contaminating the biofuel product with sulfur. A process based on decarboxylation/decarbonylation (deCO_x) offers an attractive alternative to HDO, since it requires lower amounts and pressures of hydrogen, feedstocks of low purity and cost, and simple supported metal catalysts. Herein, several geographically distributed oleaginous feedstocks – ranging from municipal waste feeds (brown grease) to pine chemicals (tall oil and rosin) – were upgraded to RD and SAF via deCOx. Powdered and engineered Ni-based catalysts were used for FOG-to-RD conversion via deCO_x, evaluating deoxygenation over reducible and non-reducible oxides. 

Engineered alumina-based catalyst showed superior deoxygenation activity and stability for up to 300 hours on stream. Similarly, quantitative conversion of FOG to SAF was achieved over bifunctional Ni-Cu-based catalysts with zeolitic supports, with deCO_x and isomerization occurring in a single step. Initial screening studies performed in a semi-batch reactor revealed that upgrading distilled tall oil (DTO) over a Ni-Cu-based catalyst afforded all types of hydrocarbons comprising SAF, namely n-alkanes, iso-alkanes, cycloalkanes, and aromatics. The same combination of feed, catalyst, and reaction conditions were applied in a fixed-bed reactor for a continuous experiment, consisting of two 72-hour cycles with catalyst regeneration in between. DTO conversion remained quantitative (~100%), with aromatic yields ≥80% regardless of time-on-stream. Most liquid products fell within the carbon number and boiling point range of jet fuel across all samples. Notably, the reaction produced all hydrocarbon classes found in SAF, with particular abundance of aromatic hydrocarbons. Since ~20% aromatics are required to swell elastomeric seals and prevent leaks in aircraft fuel systems, seal compatibility testing confirmed that the aromatics-rich SAF blendstock exhibited a volume swell percentage comparable to qualified SAF blends. Catalysts used for deoxygenation reactions were characterized using various techniques – including N₂ physisorption, X-ray diffraction, X-ray photoelectron spectroscopy, microscopy, and temperature-programmed methods – to rationalize trends, propose reaction pathways, and elucidate structure-activity relationships. Finally, to evaluate the economic and environmental feasibility of this technology, techno-economic and lifecycle analyses were conducted on an integrated plant combining catalytic deoxygenation and hydrothermal gasification, producing hydrogen for converting tall oil fatty acid to SAF. The analyses revealed a minimum fuel-selling price of USD$0.39/L – lower than that of existing SAF pathways (USD$1.4/L) – with greenhouse gas emissions of 5.1g CO₂-eq/MJ, which is 94% lower than fossil jet fuel (85g CO₂-eq/MJ). 

In absence of O₂ as terminal electron acceptors in anaerobic bacteria and archaea, carbohydrate metabolism is 15 times lesser efficient compared to aerobic energy metabolism resulting in energy deficit conditions. Despite their meager resources these anaerobes, they were able to generate H₂ and a chemiosmotic potential able to drive energy demanding reactions such as CO₂ or N₂ fixation. These observations raised concerns as production of high energy reductants (H₂) from mediocre fuels (NADH) defied the laws of thermodynamics.

In 2008, a known mechanism “electron bifurcation” but with flavins as redox mediators instead of quinones was able to overcome the thermodynamic problems behind the machinery for H₂ production and was termed as flavin based electron bifurcation (FBEB). FBEB couples an energetically uphill electron transfer to a downhill electron transfer, making the process favorable overall while generating high energy reductants from mediocre and abundant fuel.

A relatively simply system that exemplifies FBEB is the bifurcating electron transfer flavoproteins (bETF). bETFs are usually heterodimeric flavoproteins comprised of two subunits- larger EtfA formed by domain I and domain II and smaller EtfB formed by domain III. Domains I and III form the base of the protein whereas domain II sits on top of the base and is known to be dynamic, shuttling towards and away from the base. bETFs contain two non-covalently bound flavins- bifurcating FAD (Bf- FAD) is situated at the interface of domain I and domain III and electron transfer FAD (ET-FAD) is positioned in domain II. Although the two flavins are chemically identical, they demonstrate contrasting reactivities to facilitate an efficient electron bifurcation.

Thus, it is very crucial to understand the molecular basis of this mechanism implemented by these systems (bETFs) naturally which could be applied to man-made devices to satisfy their high energy needs.

Electron gating is a must to facilitate the mechanism which allows only one electron to access the exergonic pathway forcing the second electron to flow in the uphill direction, the major crux of the FBEB mechanism. A conformational gate has been proposed, to enforce this, but differential redox tuning of the two flavins is also required. The polypeptide environment of these bETFs tune the reactivities of the two flavins via non-covalent interactions thus conferring them contrasting reactivities : ET-FAD carries out 1 electron chemistry whereas Bf-FAD does 2 electron chemistry enabling it to capture maximum reducing power from NADH. Free flavins in solution can accumulate up to 1% semiquinone in solution when [OX]=[HQ]. Thus, it is very unique how nature facilitates ways to an efficient mechanism.

These bETFs share several conserved reactions in the ET site that stabilizes the ASQ (anionic semiquinone) state of ET-FAD. The unusually high E^o_(OX/ASQ) of ET-FAD has been attributed in part to a 99% conserved Arg and a 100 % conserved Ser or Thr. However, replacement of these does not suffice to suppress the ASQ of the ET-FAD, indicating that the site employs additional interaction(s) as well. 

This thesis demonstrates that  a conserved His (H290 in bETF from  Acidaminococcus fermentans) is critical, for the stability of ET-FAD_ASQ. Variants of bETF in which H290 was replaced demonstrated lower accumulation of ET-FAD_ASQ and perturbation of ET- flavin’s E^��’_Ox/SQ by 150 mV and E^��’_SQ/HQ by 100 mV. Additionally, we demonstrated that the non-covalent interactions responsible for stabilizing the one electron reactivity of ET-FAD is also responsible for activating the methide intermediate responsible for covalent modification of ET-FAD in these systems.

In this study we have also biochemically characterized a monomeric ETF from a thermophilic archaeon Sulfolobus acidocaldarius showing that it qualifies as a bETF. The SaETF retains optical features unique to reported bETFs drawing attention to similar flavin environments, a must for redox tuning. Moreover, via UV-vis spectroscopy and spectroelectrochemistry we were able to demonstrate the contrasting reactivities of the two flavins.

SaETF model demonstrates conservation of residues in the ET site responsible for modulation of one electron reactivity of ET-FAD in the established heterodimeric ETFs, and an ^ETE^o_(OX/ASQ) of -21 mV confirms the stabilization of ^ETASQ. Finally, SaETF even replicates the side effect of ASQ stabilization that is seen in established ETFs, that the ET-FAD of SaETF is prone to covalent modification. Thus, in ongoing work, we have documented the formation of different covalently modified FADs, showing that the aerobic/anaerobic nature of the atmosphere dictates products formed, and reflected on the potent nucleophile and the reaction mechanism that allows us to refine our prior proposals for the mechanism of flavin modification.

Abstract: In addition to engineering the morphology and electronic structure of electrocatalysts, local microenvironments at the electrode-electrolyte interface can markedly affect electrochemical reactions. In this talk, I will discuss two strategies that we are investigating to control concentration gradients and the chemical species at the electrode–electrolyte interface with the goal of improving activity and selectivity in electrocatalytic reactions. First, visible light excitation of noble metal plasmonic electrodes is known to generate localized charge carriers and heat. I will show that a rise in electrode surface temperature as small as 1 K from photothermal heating can induce convection in an electrolytic solution, and more than double electrochemical reaction rates. I will highlight an example where electrode surface heating affects selectivity in electrocatalytic CO₂ reduction. In a second strategy, we employ external magnetic fields to selectivity interact with and control the movement of charged particles in an electrolytic solution. In the electrocatalytic reduction of CO­₂ in a neutral, aqueous medium, I will demonstrate that the presence of a magnetic field enhances the selectivity of CO₂ reduction over solvent reduction, due to a change in the interfacial pH and pH gradient at the electrode-electrolyte interface. I will also show that reacting CO₂ with ionic liquids imparts a charge onto molecular CO₂ complexes, allowing control over its mass transport with magnetic fields, further improving selectivity toward the CO₂ reduction reaction. Collectively, the discussed results will highlight the importance of tuning chemical microenvironments with mass transport to optimize and control the outcomes of electrocatalytic reactions.

Bio: Andrew J. Wilson grew up in northeast Iowa and attended The University of Iowa where he completed his B.S. in chemistry and conducted research in sonoelectrochemistry in the lab of Johna Leddy. Following graduation, he joined the lab of Katherine A. Willets at The University of Texas at Austin for graduate studies, where he developed optical readouts to report on electrochemistry at the nanoscale. In 2015, Andrew completed his Ph.D. in physical chemistry and assisted in moving the Willets Lab to Temple University, where he continued as a postdoctoral research fellow. He moved to the University of Illinois at Urbana‒Champaign in 2016 where he was a Springborn Postdoctoral Fellow and performed research in plasmonic photochemistry in the lab of Prashant K. Jain. Andrew started his independent career at the University of Louisville in Fall 2020 where his research group focuses on advancing fundamental understanding of the interconversion of chemical and electrical energy. He has been named a Student Champion at the University of Louisville and is a recipient of the Ralph E. Powe Junior Faculty Enhancement Award and an NSF CAREER award.

Industrial processes generate a variety of separation challenges including purity targets during recycling operations, effluent limitations for wastewater treatment, or recovery operations from complex mixtures. Traditionally, these separations have been performed using precipitation chemistry, ion exchange, solvent extraction, or distillation. While effective, these options can generate large amounts of waste sludge, cost prohibitive disposal in landfills, trucking of waste product(s), and large energy usage, especially in the case of distillation. In this talk, the ability to use electrochemistry to selectively remove and recovery metals from aqueous solutions will be reviewed. Real-world operation of electrochemical separation systems will show the benefits of these processes for multiple applications while also highlighting some of the challenges that electrochemical processes face. Future opportunities in this field will be discussed as well.

Particular attention will be made to the recovery of copper from industrial streams. Copper is a component in solar panels, lithium-ion batteries, semiconductor chips, metal plating, and life science applications, making its use particularly broad. Often, the separation and recovery of high purity copper at concentrations lower than 5,000 ppm is not carried out due to the complexity of commercial separation options. The use of electrochemical separations cells can be employed in these applications to separate copper with >95% current efficiency while recovering elemental copper with >99.9% purity. Different electrodes and cell designs are used depending on the concentrations and flows where these separations are conducted and will be reviewed along with future copper opportunities.

Christian Capitini, MD

Jean R. Finley Professor in Pediatric Hematology and Oncology

Acting Director, UW Health | Carbone Cancer Center

Professor of Pediatrics

Chief, Division of Pediatric Hematology, Oncology, Transplant and Cellular Therapy

University of Wisconsin School of Medicine and Public Health

Abstract: Whole-body exposure to ionizing radiation can lead to cellular DNA damage that affects the bone marrow, causing hematopoietic acute radiation syndrome (H-ARS). Bone marrow (BM) derived mesenchymal stromal cells (MSCs) have been used for H-ARS but with limited success, and as a cellular therapy present unique challenges for rapid deployment on the battlefield. Allogeneic bone marrow transplant is currently used to rescue H-ARS, but can cause lethal complications like graft-versus-host-disease (GVHD). Known to be involved in orchestrating tissue homeostasis and wound repair, the therapeutic effects by MSCs are largely mediated by extracellular vesicles (EVs). Secreted EVs contain functional cargo such as miRNA, mRNA, and cytokines and are transferred to recipient effector cells such as monocytes and macrophages. Depending on the cargo within the EVs, monocytes and macrophages can be polarized into a M1 pro-inflammatory phenotype involved in direct host-defense against pathogens or cancer, or an M2 phenotype associated with wound healing and tissue repair. Overall, the ability to polarize MSC-EVs makes their direct use an attractive “off-the-shelf”, cell-free approach to treat injuries associated with ARS. Our results indicate that a single infusion of EVs effectively protected mice from lethal H-ARS and GVHD in vivo. The EVs promoted hematological recovery by restoring CBCs and BM cellularity. TLR4 priming with CRX-527 signals MSCs to produce radio-protective EVs, which in turn prime monocytes and macrophages in vivo to produce both anti-inflammatory molecules and growth factors that facilitate immune reconstitution, BM tissue repair and hematopoiesis.  CRX-EVs can be produced in large quantities, cryopreserved, and then thawed for immediate use after a radiation mass casualty event. Overall, ease of use and potential for large-scale production make CRX-EVs an attractive “off-the-shelf” countermeasure against radiological and nuclear threats. 

Brochure

Photo Gallery

Winners of the poster competition

• First Prize: Hannah Richards, Department of ����vlog�ٷ����, Vanderbilt University
• Second Prize: Alyson Ackerman, Department of ����vlog�ٷ����, ����vlog�ٷ����
• Honorable Mention: Josiel Barrios Cossio, Department of ����vlog�ٷ����, ����vlog�ٷ����
• Honorable Mention: Isabel Aristizabal-Ramirez, Department of Physiology, ����vlog�ٷ����

Speakers

	Dennis E. Discher, Ph.D.  Robert D. Bent Professor, and Director, Physical Sciences Oncology Center/Project University of Pennsylvania, Philadelphia, PA Biography: The Discher lab has sought to identify and elucidate some soft matter concepts across cell, molecular and tissue biology. They also have, occasionally, used biological approaches to inject some biological insights into soft matter science and engineering. Early discoveries included matrix elasticity effects on stem cell maturation and differentiation (Cell 2006), mechanosensing by a cell’s nucleus (Science 2013), and properties scaling of amphiphilic polymer assemblies for nano-delivery (Science 2002).  Current efforts focus on physics-driven evolution of mutations (Cell 2016) and engineering of macrophages to attack solid tumors (Nat BME 2023). The latter followed molecularly detailed studies of ‘foreign’ versus ‘self’ recognition (Science 2013). Dozens of trainees have secured positions in academia or industry around the world. Discher has been elected to the US National Academy of Medicine, the US National Academy of Engineering, and the American Association for the Advancement of Science, and he serves on Editorial Boards of Science, Molecular Biology of the Cell, and PNAS Nexus among other journals.
	Andrew Stephens, Ph.D. Assistant Professor, Department of Biology University of Massachusetts Amherst Biography: Prof. Andrew Stephens was born and raised in Kansas City, Missouri. He received his undergraduate degree from the University of Missouri, Kansas City and studied dynein processivity in single molecule assays. Stephens completed his Ph.D. at the University of North Carolina Chapel Hill in Dr. Kerry Bloom's lab where he studied the pericentromeric chromatin spring's essential role in yeast mitosis. He continued as a Post Doc in Dr. John Marko's lab at the University of Northwestern to adapt micromanipulation force measurements to single nuclei and study the importance of chromatin mechanics in controlling abnormal nuclear morphology which is present in many human diseases. He is now an Assistant Professor at the University of Massachusetts Amherst. The Stephens Lab was started in 2020 and uses a combination of nuclear force measurements and cell biology to determine the mechanical force balance between the nucleus and the cytoskeleton which controls nuclear shape, integrity, and function.
	John F. Marko, Ph.D. Departments of Physics & Astronomy and Molecular Biosciences Northwestern University Biography: John Marko is a professor of Physics & Astronomy and Molecular Biosciences at Northwestern University in Evanston, Illinois. He graduated from the University of Alberta, Edmonton with a B.Sc. in physics in 1984, then received his Ph.D. in physics from Massachusetts Institute of Technology in 1989. Prof. Mark��’s research interests include biological physics, statistical mechanics and theoretical soft matter physics applied to problems of self-organization in molecular and cell biology. The Marko lab uses biophysical methods, with particular emphasis on micromanipulation of single DNA molecules and single chromosomes, to study the internal structure of chromosomes in vivo, and to study chromosome-organizing proteins and DNA topoisomerases in vitro. They also develop mathematical models relevant to these types of experiments. Projects in progress involve combining fluorescence microscopy and force microscopy in experiments on DNA-protein complexes and whole chromosomes, and in-vivo studies of coupling of chromosome dynamics to gene expression.

Walking directions from Chem/Phys to Healthy Kentucky Research Building.

2025 Naff Committee:

Dr. Ryan Cheng, Chair, Department of ����vlog�ٷ����

Dr. Chris Richards, Department of ����vlog�ٷ����

Dr. Erin Peters, Department of ����vlog�ٷ����

Dr. Jakub Famulski, Department of Biology

Plastics are a miracle of modern chemistry. They are low-cost, lightweight, and endlessly formable. Plastics have been essential in improving food preservation, healthcare, energy efficiency, and consumer convenience. However, despite these benefits, the world’s inability to manage plastic waste has led to a pollution crisis with adverse effects on the environment and public health.  Although they don’t biodegrade, plastics do breakdown into micro and nano particles. Recent research indicates that these particles can penetrate the blood brain barrier and become lodged in brain tissue. The problem is not just the polymers themselves, but the chemical additives included in the formulation of plastics to modify properties. Chemical additives can make plastics more rigid, more flexible, resistant to fire, oxidation or UV light, or even add antimicrobial properties. Currently, there are more than 70,000 formulations of plastic on the market made from over 16,000 chemical species, including over 4,200 which are chemicals of concern. The long term health effects caused by plastic particles lodging in soft tissue and leaching chemicals by diffusion are largely unknown.

In an attempt to combat this crisis, in 2022, United Nations Resolution 5/14 to End Plastic Pollution with a Legally Binding Instrument by 2024 launched a series of negotiating sessions to develop a treaty to end the global plastic pollution crisis. Although the world has yet to reach agreement on a globally binding treaty, negotiations continue. Unfortunately, solutions that may be appropriate for highly developed countries are often impractical in low-GDP countries. Multiple factors, including the lack of strong governmental authority, insufficient infrastructure, and low value placed on human health versus economic development, tend to exacerbate the plastic pollution problem. Although low-GDP countries are typically only minor plastic producers, they often bear the brunt of mismanaged waste and the pollution it brings. The role of the informal sector is also important in low-GDP countries, where waste pickers often play a significant role in collecting and sorting waste, including recycling. As a result, potential solutions appropriate for low-GDP countries must be safe, simple, low-cost, and community driven. 

This seminar will focus on the current scope of the plastic pollution crisis and the specific environmental and public health challenges it causes. Additionally, the key challenges of waste plastic management globally and in low-GDP countries and some of the initiatives in place to address these challenges will be presented. Finally, the results of a case study from a small-scale, appropriate technology-based plastic-to-fuel project in Harare, Zimbabwe will be presented

Abstract: This project aims to develop the understanding of complex chemical interactions between solvent molecules and surfaces and will impact fundamental surface science as well as applied materials chemistry. Employing the novel sampling geometry, dynamic dewetting, thin fluid layers are created on solid surfaces. The molecular architectures formed within the thin fluid films are examined over varying thicknesses to reveal interfacial chemical environments. By tuning intermolecular interactions, the role of van der Waals forces, hydrogen bonding, micro-viscocity, and other chemical phenomena can be more adequately understood and applied to solve challenges in chemistry and materials science.

Bio: Research in the Shaw group combines modern analytical techniques with materials and physical chemistry to create new understanding of the molecular-level behavior at interfaces. Current and start-up projects span chemical systems that are both fundamentally intriguing and extremely relevant to current needs of our technology-driven society. Advances in these areas will allow predictive design of new, improved devices in a range of applications including energy production, polymeric materials, corrosion science, environmental remediation, microfluidics, and biomedical implanted devices. A few selected projects are outlined below. Experimental techniques encompass surface-sensitive optical spectroscopies, non-linear spectroscopies, probe microscopies, electrochemical methods, tensiometry, and novel sample preparation techniques, all targeted at revealing the interfacial properties of otherwise opaque chemical systems.   

Abstract: Known since antiquity, tuberculosis remains a major public health challenge throughout the world despite the availability of therapeutic interventions. The long treatment times of existing drugs along with the emergence of resistant variations have led researchers to seek new drugs. This seminar will describe ongoing projects to contribute to this goal, including the study of new b-lactam antitubercular agents and inhibitors of the TB phosphopantetheinyl transferase, a newly validated target. 

References

[1] Ballinger et al., Science, 2019, 363, eeau8959.

[2] Ottavi et al., J. Med. Chem., 2022, 65, 1996–2022.

[3] Ottavi et al., ACS Med. Chem. Lett., 2023, 14, 970–976.

Have you ever wondered what’s in the silo in front of the ����vlog�ٷ����-Physics building? It’s not corn or a missile, but rather the Van de Graaff particle accelerator of the ����vlog�ٷ���� Accelerator Laboratory (UKAL). UKAL opened in 1964 and is celebrating 60 years of nuclear science experiments this year. The majority of the work at UKAL focuses on neutron scattering studies for fundamental and applied science. We strive to elucidate the nature of the atomic nucleus including its excitations and shape, as well as to characterize materials relevant for projects such as next generation nuclear reactor design. A description of UKAL and this work will be given.