Browsing by Subject "COVID-19"

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Bioanalytical techniques such as immunoassays are ubiquitous in clinical and basic research laboratories and have transformed how we diagnose patients, monitor health, and study disease. Immunoassays typically use capture reagents, such as antibodies or antigens, to detect and quantify a biomarker of interest from a clinical specimen based on highly sensitive and specific binding interactions. While laboratory-based assays, such as enzyme-linked immunosorbent assay (ELISA), are the workhorses of clinical laboratories, they have several shortcomings that limit their overall utility, especially in low resource settings. Of note, ELISA requires multiple timed incubation steps, trained personnel, expensive equipment, and suffers from long times to result. To democratize access to clinical-grade tests, researchers have sought out different methods for point-of-care (POC) testing that are easy to perform and maintain high sensitivity and specificity. This dissertation describes the use of a “zero-background” polymer coating—poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA)—as a substrate for highly sensitive and specific POC diagnostic tests. The POEGMA coating eliminates nearly all non-specific protein adsorption and cellular adhesion, thus leading to high signal-to-noise ratios, even from complex biological samples, such as whole blood. In addition, the POEGMA brush contains all biomolecules necessary to complete an assay after addition of a liquid sample, thus allowing assays to be conducted in a single step. Further, the POEGMA coating stabilizes biomolecules on the surface, which allows tests to be stored at ambient conditions without refrigeration. Assays are read out using a fluorescence detector which quantifies the concentration for a given biomarker of interest. By inkjet printing capture biomolecules at discrete spatial addresses on the POEGMA-slides, multiplexing can be accomplished using a single fluorophore which greatly reduces the complexity and costs for assay readout. This dissertation focuses on adapting and applying this platform to several clinically relevant applications. First, we developed a test for molecular and cellular credentialing of breast cancer tissue at the POC (Chapter 2). With the onset of the coronavirus 2019 (COVID-19) pandemic, we adapted the platform to detect several different relevant biomarkers for COVID-19, including total antibody concentration against several viral proteins (Chapter 3), neutralizing antibodies (Chapter 4), and viral proteins (Chapter 5). All the tests developed for COVID-19 use multiplexed sensing strategies and can be conducted with minimal/no user intervention or clinical infrastructure. Taken together, these studies highlight the great potential for bioanalytical assays built upon POEGMA-coated substrates to be used for clinical applications in disease diagnosis, surveillance, and management.

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This study aims to explain the logic behind rumor rebuttal, a form of responsivepropaganda, in authoritarian countries during COVID-19, the story of which initially unfolded as ”rumor”. Taking China at the beginning stage of the outbreak as an example, I generate an original data of unverified and undesirable information on social media set, by combining both refuted and censored posts through keyword matching. I find that when faced with a dilemma between being responsive to the social need of accurate information to control the pandemic and securing authoritarian rule by not repeating rumor so as to increase its spreading power, the Chinese government chooses to refute rumors that have no political implications. When refuting rumors with political implications, censorship is also adopted. This study contributes to an understudying of information politics in authoritarian regimes. I analyze how an authoritarian government carries out a campaign against undesirable information using multiple techniques simultaneously, and I make a clear distinction between rumor content and political implications, which is noted in the literature but has not been used to understand authoritarian government communication behavior so far.

Background: The COVID-19 pandemic amplified disparities experienced by children in immigrant and refugee families (CIRF). The pandemic coincided with a recognition that proactively screening and addressing social risk drivers is an efficacious population health intervention. We used the Reach, Efficacy, Adoption, Implementation and Maintenance (RE-AIM) framework to set up a program to screen for social risks drivers at a Federally Qualified Health Center (FQHC). The study sought to demonstrate to what extent the proactive outreach program would a) capture at-risk persons and b) facilitate linkage of identified persons to community resources. We sought to c) quantify social needs among CIRF and d) understand whether addressing social risk drivers would lead to caregivers perceiving an improvement in their child’s health. Lastly, we sought to e) elucidate the experiences with and preferences of families in regard to screening efforts. Methods: The study was conducted at the Lincoln Community Health Center in Durham, North Carolina. Eligible participants were ages 0-5, non-English speaking, and were seen at the clinic within the last 2 years. A care coordinator reached out to the guardians of eligible children for baseline screening. Participants with social needs received referral placement and navigation support. We looked at the number of baseline questionnaires completed, linkage rates and resolution of social needs as well as perceptions of SDOH screening and perceived changes in child’s health using descriptive and univariate statistics. Results: We attempted to contact 342 guardians; to date, we did not reach 85 (24.85%) participants and 21 (6.14%) have incomplete outreach. 212 (61.99%) participants were enrolled and completed baseline screening. Most participants had at least one social need. Of the 212 individuals enrolled, the 39 who completed the intervention (100%) indicated that the calls helped them to gain a better understanding of community resources. When asked who they would be most comfortable talking with about their social needs, the majority indicated a case manager in person (34, 89.5%) or over the phone (36, 94.74%). When asked about what characteristics were important to them when considering who they might speak with about their social needs, 36 (92.1%) selected language and 22 (57.9%) indicated that cultural affiliation was important. The impact of the intervention on the perception of child’s health was unable to be quantified due to a small sample size. Conclusion: Our findings illustrate the burden of social risk drivers experienced by CIRF and demonstrate the capacity of a proactive outreach SDOH screening program to meet the needs of CIRF served by a FQHC. It is our hope that this screening tool and proactive outreach program can be used as a model to better identify and address the social needs of CIRF and to thus enhance health outcomes and population health.

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