Open Access Publications
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Open access publications by faculty, postdocs, and graduate students in the Department of Chemical and Biomolecular Engineering
Now showing 1 - 5 of 45
- ItemFlowthrough of 239PU and 55FE during RNA extraction(Journal of Radiological Protection, 2023-01-31) Manglass, Lisa M.; Vogel, Charlotte M.; Wintenberg, Molly; Blenner, Mark A.; Martinez, Nicole E.Analysis of gene expression has become an important tool in understanding low-dose effect mechanisms of ionizing radiation at the cellular level. Metal binding to nucleic acids needs to be considered when interpreting these results, as some radioactive metals, particularly actinides, may produce free radicals and cause oxidative stress damage via chemical means at rates much higher than free radical formation related to their radiological properties. Bacteria exposed in situ to low dose rates of plutonium-239 (239Pu) and iron-55 (55Fe) were previously analysed for gene expression. The work herein was motivated by an interest in more precisely identifying the distribution of radionuclides in these bacteria as well as the practical need to ensure appropriate transport and handling of the associated ribonucleic acid (RNA) extractions. RNA extractions were performed on bacteria growth media with and without bacteria cells (i.e. with and without RNA) at several different concentrations of 239Pu and 55Fe to inform the level of specificity of the extraction membrane as well as provide insight into internal (uptake) vs external (sorption) accumulation of these radionuclides in bacteria cells. Results of the study suggest that 239Pu and 55Fe detected in RNA extraction samples during long term cell studies is the result of binding to RNA prior to the time of extraction, as opposed to flow through or binding after cell lysis, and it highlights the practical importance of nucleic acid sample characterization to radiation protection more generally.
- ItemCharacterization and implications of host-cell protein aggregates in biopharmaceutical processing(Biotechnology and Bioengineering, 2023-03-14) Oh, Young Hoon; Becker, Matthew L.; Mendola, Kerri M.; Choe, Leila H.; Min, Lie; Lee, Kelvin H.; Yigzaw, Yinges; Seay, Alexander; Bill, Jerome Jr.; Li, Xuanwen; Roush, David J.; Cramer, Steven M.; Menegatti, Stefano; Lenhoff, Abraham M.In the production of biopharmaceuticals such as monoclonal antibodies (mAbs) and vaccines, the residual amounts of host-cell proteins (HCPs) are among the critical quality attributes. In addition to overall HCP levels, individual HCPs may elude purification, potentially causing issues in product stability or patient safety. Such HCP persistence has been attributed mainly to biophysical interactions between individual HCPs and the product, resin media, or residual chromatin particles. Based on measurements on process streams from seven mAb processes, we have found that HCPs in aggregates, not necessarily chromatin-derived, may play a significant role in the persistence of many HCPs. Such aggregates may also hinder accurate detection of HCPs using existing proteomics methods. The findings also highlight that certain HCPs may be difficult to remove because of their functional complementarity to the product; specifically, chaperones and other proteins involved in the unfolded protein response (UPR) are disproportionately present in the aggregates. The methods and findings described here expand our understanding of the origins and potential behavior of HCPs in cell-based biopharmaceutical processes and may be instrumental in improving existing techniques for HCP detection and clearance.
- ItemBest practices for electrochemical reduction of carbon dioxide(Nature Sustainability, 2023-01-02) Seger, Brian; Robert, Marc; Jiao, FengCarbon capture, utilization and storage, a fundamental process to a sustainable future, relies on a suite of technologies among which electrochemical reduction of carbon dioxide is essential. Here, we discuss the issues faced when reporting performance of this technology and recommend how to move forward at both materials and device levels. Electrochemical reduction of CO2 into value-added chemicals has attracted considerable attention recently1,2,3. However, reporting the performance of a new CO2 electrocatalyst or a new reactor design is not trivial because of the complex nature of the CO2 electroreduction reaction. In many cases, the results are presented in a confusing manner, rendering it difficult to assess the true performance of the catalyst and/or device. In this Comment, we first discuss common problems in reporting the performance of a new electrocatalyst (including both heterogeneous and molecular catalysts) in the literature and then extend the discussion to how the products should be properly measured and quantified. Finally, we comment on the issues associated with full-cell level studies and recommend the best practices for electrochemical CO2 reduction.
- ItemTechno-Economic Assessment of Green H2 Carrier Supply Chains(Energy Fuels, 2023-01-19) Crandall, Bradie S.; Brix, Todd; Weber, Robert S.; Jiao, FengGreen hydrogen can play a key role in affordably decarbonizing society. However, storage and transmission costs pose significant barriers to green hydrogen distribution. These limitations may be overcome with liquid green hydrogen carriers like ammonia, methanol, and toluene/methylcyclohexane, as well as formic acid, which has only recently received limited attention. A techno-economic assessment of these hydrogen carriers is presented across a wide range of scales. Green formic acid is identified to be the most cost-effective carrier when the entire supply-chain cost is considered. Additional analysis shows that formic acid is the only green carrier that is more affordable to produce than its fossil-based counterpart and is the safest of the studied carriers. Finally, research and policy outlooks are provided to guide efforts toward the realization of a green hydrogen economy. This work provides information on the selection of a suitable green hydrogen carrier, which is essential to decarbonize at the rate needed to avoid climate catastrophe.
- ItemEffect of scatterer interactions on photon transport in diffusing wave spectroscopy(Physical Review E, 2022-12-16) Sbalbi, Nicholas; Li, Qi; Furst, Eric M.We calculate the effect of particle size, concentration, and interactions on the photon transport mean-free path l∗ that characterizes the multiple light scattering in diffusing wave spectroscopy (DWS). For scatterers of sufficient size, such that the first peak of the suspension structure factor S(qmax) remains in the range of accessible scattering vectors, neither repulsive nor attractive interactions between scatterers contribute strongly to l∗; its values are bounded by those for hard spheres and scatterers without interactions. However, for scatterers smaller than the wavelength of light, crowding induced by attraction or repulsion can lead to nonmonotonic behavior in l∗ with increasing scatterer concentration. The effect is strongest for repulsive particles.