Institutional Repository

The UDSpace Institutional Repository collects and disseminates research material from the University of Delaware.

Faculty, staff, and graduate students who want their research material hosted in UDSpace should contact the University of Delaware Insitutional Repository team at openaccess@udel.edu.
Faculty may use UDSpace to fulfill the University of Delaware Faculty Senate Open Access Resolution, and in many cases may use it to fulfill open access requirements from grant funding agencies.
Departments can use UDSpace to publish or distribute their working papers, technical reports, or other research material.
UDSpace also includes all doctoral dissertations from winter 2014 forward, and all master's theses from fall 2009 forward.

To learn more about UDSpace, and how you can make your research openly accessible to the public, visit our UDSpace Information website.

Communities in DSpace

Select a community to browse its collections.

Recent Submissions

Electrochemical Deconstruction of Ortho-Phthalate Plasticizers and Recovery of Plasticizing Moieties
(Compounds, 2026-06-26) Dauzvardis, Fabian; Rosenthal, Joel
Electrochemical methods for the direct reduction of alkyl esters have been understudied but provide a potential advantage for addressing specific waste streams given that such strategies often require only a minimal chemical profile. One such waste stream that could benefit from electrochemical remediation is poly(vinyl chloride) (PVC) plastics. PVC recycling often faces challenges due to the complexity of such waste. Solvent-based recycling methods pose several advantages for addressing post-use PVC; however, such methods are complicated by the high amounts of toxic legacy plasticizers (ortho-phthalates) present in PVC. A potential solution to addressing such phthalates is to address them electrochemically, coupled with recovery of the resulting valuable products. Presented herein is an optimized electrochemical method for ester activation that is leveraged to separate and recover the aromatic and alkyl components of ortho-phthalate plasticizers. The resulting aliphatic alcohols may be reused to prepare other non-toxic plasticizers. This electro-degradation method is demonstrated on six phthalates that have been identified to pose health concerns in addition to plasticizers recovered from commercial samples of PVC.
Geographic Availability and Use of Medications for Opioid Use Disorder Among Medicaid Enrollees
(JAMA Health Forum, 2026-06-26) Drake, Coleman; Sharbaugh, Michael; Nagy, Dylan; Kim, Joo Yeon; Zang, Crystal; Ahrens, Katherine A; Allen, Lindsay; Barnes, Andrew J; Hyman, Jacob Baxter; Case, Stuart Jacob; Junker, Stefanie; Cai, Yilin; Clark, Sarah J; Durrance, Christine; Fry, Carrie; Gifford, Katie; Gordon, Adam J; Hammerslag, Lindsey; Jonk, Yvonne; Pierre-Louis, Sherline; Mack, Aimee; Marks, Sarah; Sandahl, Melissa A; Tossone, Krystel; Ware, Orrin; Williams, Tim; Tang, Lu; Donohue, Julie M
Importance There are large racial and ethnic differences in the use of medications for opioid use disorder (MOUD). Whether differences in geographic availability of MOUD providers (defined in this study as buprenorphine prescribers, methadone dispensing opioid treatment programs, and naltrexone prescribers) contribute to these differences in Medicaid is unknown. Objective To examine differential geographic availability of MOUD in Medicaid and whether it is associated with MOUD use. Design, Setting, and Participants This cross-sectional study analyzed the geographic availability of Medicaid prescribers of MOUD in 2021, spanning 10 states (Delaware, Kentucky, Maryland, Maine, Michigan, North Carolina, Pennsylvania, Tennessee, Virginia, and West Virginia) in the Medicaid Outcomes Distributed Research Network. The study population included Medicaid enrollees aged 18 to 64 not enrolled in Medicare and their MOUD providers. The data analysis was conducted from December 2022 to April 2026. Exposures Geographic availability was measured at the zip code level (number of MOUD providers available in Medicaid within a 15-minute drive time per 100 Medicaid enrollees). Main Outcomes and Measures Main outcomes included the probability of buprenorphine, methadone, and naltrexone use as a function of enrollee race and ethnicity, whether they had above-median geographic availability, and interactions between above-median geographic availability and race and ethnicity. Results The sample included 8 081 899 Medicaid enrollees; 472 409 (5.8%) had an OUD diagnosis. The population was 58.7% female and 41.3% male. Among the study population, 11.7% were aged 18 to 20 years, 39.5% were aged 21 to 34 years, 21.4% were aged 35 to 44 years, 14.5% were aged 45 to 54 years, and 12.9% were aged 55 to 64 years. Overall, 7.3% of the sample were Hispanic enrollees, 27.4% were non-Hispanic Black enrollees, 56.2% were non-Hispanic White enrollees, and 7.2% were enrollees from other racial and ethnic groups. Overall, 13 575 buprenorphine prescribers, 516 methadone dispensers, and 4801 naltrexone prescribers billed Medicaid. Median Medicaid MOUD providers available within a 15-minute drive were 0.89 per 100 enrollees for buprenorphine, 0.03 for methadone, and 0.32 for naltrexone. Above-median geographic availability of methadone was associated with a 0.99 (95% CI, 0.54-1.42)–percentage point increase in methadone use for non-Hispanic White enrollees; there was no such increase for non-Hispanic Black or Hispanic enrollees. Evidence of similar differences was limited for naltrexone. Above-median availability of buprenorphine was not associated with increased use of MOUD for any racial or ethnic group. Conclusions and Relevance In this cross-sectional study of 10 state Medicaid programs, greater geographic availability of MOUD was associated with increased use only for methadone and, to a lesser extent, naltrexone. No racial and ethnic groups experienced gains in use associated with improved access. Additional strategies beyond addressing geographic access may be needed to close racial and ethnic gaps in MOUD.
2026, 25th Issue, part 2
(Newark, Del.: Chesapeake Pub. Corp., 2026-07-10) Newark post
2026, 25th Issue, part 1
(Newark, Del.: Chesapeake Pub. Corp., 2026-07-10) Newark post
Single-cell heterogeneity in ribosome levels and protein synthesis during nutrient starvation is driven by cAMP signaling
(Science Advances, 2026-06-26) Lyu, Zhihui; Augenstreich, Jacques; Briken, Volker; Singh, Abhyudai; Mori, Matteo; Hwa, Terence; Ling, Jiqiang
Ribosomes are central to protein synthesis and a frequent target for antibiotics. In fast-growing bacteria, the ribosome content is proportional to the growth rate; how ribosomes and protein synthesis are regulated during nutrient starvation remains poorly understood, particularly in single cells. To address this, we fluorescently labeled ribosomal proteins (RPs) in Salmonella and explored their variations and regulation in single cells. We show that the RP levels become heterogeneous during the transition to the stationary phase. Unexpectedly, cells with higher RP levels responded less to the induction of gene expression but accumulated more virulence gene products. Our work further reveals that adenosine 3′,5′-monophosphate (cAMP) signaling increases the heterogeneity of the levels of RPs and other gene products. Fluorescence dilution assay and proteomic analysis indicate that cAMP signaling promotes gene expression heterogeneity by directing proteome-wide adaptation, which enables growth heterogeneity, hence differential dilution of gene products during nutrient depletion.