Bulk Depolymerization of Methacrylate Polymers via Pendent Group Activation.

In this study, we present an efficient approach for the depolymerization of poly(methyl methacrylate) (PMMA) copolymers synthesized via conventional radical polymerization. By incorporating low mol % phthalimide ester-containing monomers during the polymerization process, colorless and transparent polymers closely resembling unfunctionalized PMMA are obtained, which can achieve >95% reversion to methyl methacrylate (MMA). Notably, our catalyst-free bulk depolymerization method exhibits exceptional efficiency, even for high-molecular-weight polymers, including ultrahigh-molecular-weight (106-107 g/mol) PMMA, where near-quantitative depolymerization is achieved. Moreover, this approach yields polymer byproducts of significantly lower molecular weight, distinguishing it from bulk depolymerization methods initiated from chain ends. Furthermore, we extend our investigation to polymethacrylate networks, demonstrating high extents of depolymerization. This innovative depolymerization strategy offers promising opportunities for the development of sustainable polymethacrylate materials, holding great potential for various applications in polymer science.

Chronic alcohol use primes bronchial cells for altered inflammatory response and barrier dysfunction during SARS-CoV-2 infection.

Alcohol use disorder (AUD) is a significant public health concern and people with AUD are more likely to develop severe acute respiratory distress syndrome (ARDS) in response to respiratory infections. To examine whether AUD was a risk factor for more severe outcome in response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we examined early responses to infection using cultured differentiated bronchial epithelial cells derived from brushings obtained from people with AUD or without AUD. RNA-seq analysis of uninfected cells determined that AUD cells were enriched for expression of epidermal genes as compared with non-AUD cells. Bronchial epithelial cells from patients with AUD showed a significant decrease in barrier function 72 h postinfection, as determined by transepithelial electrical resistance. In contrast, barrier function of non-AUD cells was enhanced 72 h after SARS-CoV-2 infection. AUD cells showed claudin-7 that did not colocalize with zonula occludens-1 (ZO-1), indicative of disorganized tight junctions. However, both AUD and non-AUD cells showed decreased ß-catenin expression following SARS-CoV-2 infection. To determine the impact of AUD on the inflammatory response to SARS-CoV-2 infection, cytokine secretion was measured by multiplex analysis. SARS-CoV-2-infected AUD bronchial cells had enhanced secretion of multiple proinflammatory cytokines including TNFα, IL-1ß, and IFNγ as opposed to non-AUD cells. In contrast, secretion of the barrier-protective cytokines epidermal growth factor (EGF) and granulocyte macrophage-colony stimulating factor (GM-CSF) was enhanced for non-AUD bronchial cells. Taken together, these data support the hypothesis that AUD is a risk factor for COVID-19, where alcohol primes airway epithelial cells for increased inflammation and increased barrier dysfunction and increased inflammation in response to infection by SARS-CoV-2.NEW & NOTEWORTHY Alcohol use disorder (AUD) is a significant risk factor for severe acute respiratory distress syndrome. We found that AUD causes a phenotypic shift in gene expression in human bronchial epithelial cells, enhancing expression of epidermal genes. AUD cells infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had higher levels of proinflammatory cytokine secretion and barrier dysfunction not present in infected non-AUD cells, consistent with increased early COVID-19 severity due to AUD.

Inverse Miniemulsion Enables the Continuous-Flow Synthesis of Controlled Ultra-High Molecular Weight Polymers.

We report the controlled synthesis of ultra-high molecular weight (UHMW) polymers (Mn ≥ 106 g/mol) via continuous flow in a tubular reactor. At high monomer conversion, UHMW polymers in homogeneous batch polymerization exhibit high viscosities that pose challenges for employing continuous flow reactors. However, under heterogeneous inverse miniemulsion (IME) conditions, UHMW polymers can be produced within the dispersed phase, while the viscosity of the heterogeneous mixture remains approximately the same as the viscosity of the continuous phase. Conducting such IME polymerizations in flow results in a faster rate of polymerization compared to batch IME polymerizations while still providing excellent control over molecular weight up to 106 g/mol. Crucial emulsion parameters, such as particle size and stability under continuous flow conditions, were examined using dynamic light scattering. A range of poly(N,N-dimethylacrylamide) and poly(4-acryloylmorpholine) polymers with molecular weights of 104-106 g/mol (D ≤ 1.31) were produced by this method using water-soluble trithiocarbonates as photoiniferters.

Direct wastewater extraction as a simple and effective method for SARS-CoV-2 surveillance and COVID-19 community-level monitoring.

Wastewater surveillance has proven to be an effective tool to monitor the transmission and emergence of infectious agents at a community scale. Workflows for wastewater surveillance generally rely on concentration steps to increase the probability of detection of low-abundance targets, but preconcentration can substantially increase the time and cost of analyses while also introducing additional loss of target during processing. To address some of these issues, we conducted a longitudinal study implementing a simplified workflow for SARS-CoV-2 detection from wastewater, using a direct column-based extraction approach. Composite influent wastewater samples were collected weekly for 1 year between June 2020 and June 2021 in Athens-Clarke County, Georgia, USA. Bypassing any concentration step, low volumes (280 µl) of influent wastewater were extracted using a commercial kit, and immediately analyzed by RT-qPCR for the SARS-CoV-2 N1 and N2 gene targets. SARS-CoV-2 viral RNA was detected in 76% (193/254) of influent samples, and the recovery of the surrogate bovine coronavirus was 42% (IQR: 28%, 59%). N1 and N2 assay positivity, viral concentration, and flow-adjusted daily viral load correlated significantly with per-capita case reports of COVID-19 at the county-level (ρ = 0.69-0.82). To compensate for the method's high limit of detection (approximately 106-107 copies l-1 in wastewater), we extracted multiple small-volume replicates of each wastewater sample. With this approach, we detected as few as five cases of COVID-19 per 100 000 individuals. These results indicate that a direct-extraction-based workflow for SARS-CoV-2 wastewater surveillance can provide informative and actionable results.

Excitation Dependence in Photoiniferter Polymerization.

We report on a fundamental feature of photoiniferter polymerizations mediated with trithiocarbonates and xanthates. The polymerizations were found to be highly dependent on the activated electronic excitation of the iniferter. Enhanced rates of polymerization and greater control over molecular weights were observed for trithiocarbonate- and xanthate-mediated photoiniferter polymerizations when the n → π* transition of the iniferter was targeted compared to the polymerizations activating the π → π* transition. The disparities in rates of polymerization were attributed to the increased rate of C-S photolysis which was confirmed using model trapping studies. This study provides valuable insight into the role of electronic excitations in photoiniferter polymerization and provides guidance when selecting irradiation conditions for applications where light sensitivity is important.

Magnetic Properties of High-Nuclearity Fex-oxo (x = 7, 22, 24) Clusters Analyzed by a Multipronged Experimental, Computational, and Magnetostructural Correlation Approach.

The synthesis, structure, and magnetic properties of three related iron(III)-oxo clusters are reported, [Fe7O3(O2CPh)9(mda)3(H2O)] (1), [Fe22O14(OH)3(O2CMe)21(mda)6](ClO4)2 (2), and [Fe24O15(OH)4(OEt)(O2CMe)21(mda)7](ClO4)2 (3), where mdaH2 is N-methyldiethanolamine. 1 was prepared from the reaction of [Fe3O(O2CPh)6(H2O)3](NO3) with mdaH2 in a 1:2 ratio in MeCN, whereas 2 and 3 were prepared from the reaction of FeCl3/NaO2CMe/mdaH2 in a 2:∼13:2 ratio and FeCl3/NaO2CMe/mdaH2/pyridine in a 2:∼13:2:25 ratio, respectively, both in EtOH. The core of 1 consists of a central octahedral FeIII ion held within a nonplanar Fe6 loop by three µ3-O2- and three µ2-RO- arms from the three mda2- chelates. The cores of the cations of 2 and 3 consist of an A:B:A three-layer topology, in which a central Fe6 (2) or Fe8 (3) layer B is sandwiched between two Fe8 layers A. The A layers structurally resemble 1 with the additional Fe added at the center to retain virtual C3 symmetry. The central Fe6 layer B of 2 consists of a {Fe4(µ4-O)2(µ3-OH)2}6+ cubane with an Fe on either side attached to cubane O2- ions, whereas that of 3 has the same cubane but with an {Fe3(µ3-O)(µ-OH)} unit attached on one side and a single Fe on the other. Variable-temperature dc and ac magnetic susceptibility studies revealed dominant antiferromagnetic coupling in all complexes leading to ground-state spins of S = 5/2 for 1 and S = 0 for 2 and 3. All Fe2 pairwise exchange parameters (Jij) for 1-3 were estimated by two independent methods: density functional theory (DFT) calculations using broken symmetry methods and a magnetostructural correlation previously developed for high-nuclearity FeIII/O complexes. The two approaches gave satisfyingly similar Jij values, and the latter allowed rationalization of the experimental ground states by identification of the spin frustration effects operative and the resultant relative spin vector alignments at each FeIII ion.

The School Nutrition and Meal Cost Study-I: Overview of Findings Related to Improving Diet Quality, Weight, and Disparities in US Children and Policy Implications.

The national school breakfast and lunch programs administered by the United States Department of Agriculture (USDA) are a cornerstone of the nation's nutrition safety net for children from low-income families [...].

Developing a National Research Agenda to Support Healthy Food Retail.

The food retail environment is an important driver of dietary choices. This article presents a national agenda for research in food retail, with the goal of identifying policies and corporate practices that effectively promote healthy food and beverage purchases and decrease unhealthy purchases. The research agenda was developed through a multi-step process that included (1) convening a scientific advisory committee; (2) commissioned research; (3) in-person expert convening; (4) thematic analysis of meeting notes and refining research questions; (5) follow-up survey of convening participants; and (6) refining the final research agenda. Public health researchers, advocates, food and beverage retailers, and funders participated in the agenda setting process. A total of 37 research questions grouped into ten priority areas emerged. Five priority areas focus on understanding the current food retail environment and consumer behavior and five focus on assessing implementation and effectiveness of interventions and policies to attain healthier retail. Priority topics include how frequency, duration, and impact of retailer promotion practices differ by community characteristics and how to leverage federal nutrition assistance programs to support healthy eating. To improve feasibility, researchers should explore partnerships with retailers and advocacy groups, identify novel data sources, and use a variety of study designs. This agenda can serve as a guide for researchers, food retailers, funders, government agencies, and advocacy organizations.

Developing a national research agenda to reduce consumption of sugar-sweetened beverages and increase safe water access and consumption among 0- to 5-year-olds: a mixed methods approach.

OBJECTIVE: Sugar-sweetened beverage (SSB) consumption in early childhood is a public health concern. Adequate hydration in early childhood is also important. We developed a national research agenda to improve beverage consumption patterns among 0-5-year-olds. This article focuses on the process used to develop this research agenda. DESIGN: A mixed methods, multi-step process was used to develop the research agenda, including: (i) a scientific advisory committee; (ii) systematic reviews on strategies to reduce SSB consumption and increase water access and consumption; (iii) two stakeholder surveys to first identify and then rank strategies to reduce SSB consumption and increase water access and consumption; (iv) key informant interviews to better understand determinants of beverage consumption and strategies to improve beverage consumption patterns among high-risk groups; (v) an in-person convening with experts; and (vi) developing the final research agenda. SETTING: This process included research and stakeholders from across the United States. PARTICIPANTS: A total of 276 participants completed survey 1 and 182 participants completed survey 2. Key informant interviews were conducted with 12 stakeholders. Thirty experts attended the convening, representing academia, government, and non-profit sectors. RESULTS: Thirteen key issue areas and 59 research questions were developed. Priority topics were beverage consumption recommendations, fruit-flavoured drink consumption, interventions tailored to high-risk groups, and family engagement in childcare. CONCLUSIONS: This research agenda lays the groundwork for research efforts to improve beverage patterns of young children. The methods used can be a template to develop research agendas for other public health issues.

Strength of obesity prevention interventions in early care and education settings: A systematic review.

TIME AND PLACE OF STUDY: 2010-2015; INTERNATIONAL: Given the high levels of obesity in young children, numbers of children in out-of-home care, and data suggesting a link between early care and education (ECE) participation and overweight/obesity, obesity prevention in ECE settings is critical. As the field has progressed, a number of interventions have been reviewed yet there is a need to summarize the data using more sophisticated analyses to answer questions on the effectiveness of interventions. We conducted a systematic review of obesity prevention interventions in center-based ECE settings published between 2010 and 2015. Our goal was to identify promising intervention characteristics associated with successful behavioral and anthropometric outcomes. A rigorous search strategy resulted in 43 interventions that met inclusion criteria. We developed a coding strategy to assess intervention strength, used a validated study quality assessment tool, and presented detailed descriptive information about interventions (e.g., target behaviors, intervention strategies, and mode of delivery). Intervention strength was positively correlated with reporting of positive anthropometric outcomes for physical activity, diet, and combined interventions, and parent engagement components increased the strength of these relationships. Study quality was modestly related to percent successful healthy eating outcomes. Relationships between intervention strength and behavioral outcomes demonstrated negative relationships for all behavioral outcomes. Specific components of intervention strength (number of intervention strategies, potential impact of strategies, frequency of use, and duration of intervention) were correlated with some of the anthropometric and parent engagement outcomes. The review provided tentative evidence that multi-component, multi-level ECE interventions with parental engagement are most likely to be effective with anthropometric outcomes.

The School Food Environment and Obesity Prevention: Progress Over the Last Decade.

The school food environment-including when and where children obtain food and the types of options available during the school day-plays an important role in children's consumption patterns. Thus, childhood obesity prevention efforts often focus on altering the school food environment as a mechanism for improving student dietary intake. This review examines the role school food programs and policies play in improving children's diet, weight, and health. Overall, research suggests that significant improvements have been made in school nutrition policies and programs. Due to the recent program changes made as a result of the 2010 Healthy, Hunger-Free Kids Act, an emphasis was placed on research conducted over the past decade and especially on the evaluation of foods and beverages served and sold since implementation of this national law. This review also examines remaining gaps in the literature and opportunities for further improvements in school food programs and policies.

Farm to institution: creating access to healthy local and regional foods.

Farm to Institution (FTI) programs are one approach to align food service operations with health and sustainability guidelines, such as those recently developed by the U.S. Department of Health and Human Services and General Services Administration. Programs and policies that support sourcing local and regional foods for schools, hospitals, faith-based organizations, and worksites may benefit institutional customers and their families, farmers, the local community, and the economy. Different models of FTI programs exist. On-site farmer's markets at institutions have been promoted on federal government property, healthcare facilities, and private institutions nationwide. Farm to School programs focus on connecting schools with local agricultural production with the goal of improving school meals and increasing intake of fruits and vegetables in children. Sourcing food from local farms presents a number of challenges including cost and availability of local products, food safety, and liability considerations and lack of skilled labor for food preparation. Institutions utilize multiple strategies to address these barriers, and local, state, and federal polices can help facilitate FTI approaches. FTI enables the purchasing power of institutions to contribute to regional and local food systems, thus potentially affecting social, economic, and ecological systems. Local and state food policy councils can assist in bringing stakeholders together to inform this process. Rigorous research and evaluation is needed to determine and document best practices and substantiate links between FTI and multiple outcomes. Nutritionists, public health practitioners, and researchers can help communities work with institutions to develop, implement, and evaluate programs and policies supporting FTI.