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A new organocatalyst for the ring-opening polymerization of lactones has been identified. Under the tested conditions, the anions of 2,2'-bisindole promote fast, living polymerizations (as short as 10 ms) which are selective for chain elongation over transesterification (Đ ≤ 1.1). While structurally related to (thio)urea anion catalysts, anions of 2,2'-bisindole activate the monomer via the counterion rather than through hydrogen bonding. This new activation motif enables modulation of the polymerization rate by 2 orders of magnitude by changing the counterion.

Point of care ultrasound (POCUS) has become an increasingly common diagnostic tool in the clinical environment. As a result, it is being used earlier for medical students in Undergraduate Medical Education (UME) as a learning tool for the basic sciences including gross anatomy. There is little literature, however, to support its utility for basic science education in students currently seeking a bachelor’s degree. This study consisted of fourteen currently enrolled bachelor students with previous instruction in human anatomy and physiology. Students participated in an ultrasound didactic and an interactive ultrasound experience with volunteers. Before and after this session, students were asked to complete an assessment measuring their spatial understanding of the human anatomy and their ability to locate structures using ultrasound. Wilcoxon’s signed-rank tests comparing assessment scores showed significant improvement on both portions of the assessment. Based on this improvement, we suggest that ultrasound is a valid educational tool which can be used at the bachelor-level to effectively enhance students’ learning of anatomy and provide hands on experience with modern technology. Further research with larger samples will be necessary to determine whether it would supplement or replace more traditional teaching modalities.

The controlled anionic ring-opening polymerization of lactones and siloxanes is carried out in continuous-flow reactors. Anionic ring-opening polymerization of cyclic esters with strong, soluble ba...

Synthetic materials are integral components of consumable and durable goods and are indispensable in the modern world. Polyesters are the most versatile bulk- and specialty-polymers but their production is not sustainable and their fate at end-of-life is of great concern. Bioplastics are highly regarded alternatives but often fall behind conventional synthetic plastics due to shortcomings in material properties and commercial competitiveness. This has limited the success of sustainable replacements at global market scale. Enabling production of bioplastics with superior properties from waste-derived feedstocks could change that. To this end, we created a synthetic entry into the metabolic pathway of bio-polyester synthesis ofCupriavidus necatorH16 by means of heterologous hydroxyacyl-CoA transferase and mutant PHA synthase. The resulting microbial cell factories produced a range of aliphatic and aromatic biopolyesters and enabled co-polymerization of a range of hydroxy carboxylates, including a hydroxyphenylic and a hydroxyfuranoic acid, for the first time incorporating aromatic rings in the backbone of biological polyesters. These diverse polymers were then characterized in terms of their physical properties. The resulting polymers were structurally analogous to synthetic polyesters like PET, PEF and other polyarylates. In a further advance, the transgenic strain was cultivated in a bio-electrochemical system under autotrophic conditions, enabling synthesis of aromatic bio-polyesters fromin-situgenerated O2, while assimilating CO2. Follow-up elementary flux-mode analysis established the feasibility ofde novoproduction of twenty different polyesters from five different carbon- and energy-sources. This comprehensive study opens the door to sustainable bio-production of various high-performance thermoplastics and thermosets.Significance statementBiomaterials can facilitate the transition of chemical industry to a carbon-neutral and circular economy and prevent the accumulation of greenhouse gases and plastic waste in the natural environment by developing bio-replacements for existing fossil carbon-based plastics along with end-of-life strategies. Accomplished via the genetic engineering of a microbial cell factory that assimilates carbon dioxide, this work demonstrates the first biocatalytic polymerization of aromatic building blocks and their incorporation into the backbone of a bio-polyester. Employing a bio-electrochemical system for cultivation of the microbes, oxyhydrogen is formed and consumedin-situ, thus avoiding explosive gasmixtures. The obtained aromatic polyesters are structural analogs to synthetic bulk- and high-performance polymers such as PET (polyethylene terephthalate) and PEF (polyethylene furanoate).Highlights-First demonstration of bio-polyarylates – microbial polyesters with aromatic rings in the backbone-Production of novel PHAs from CO2and H2+O2achievedin-situin a bio-electrochemical system-Expression-level of PHA synthase and molecular weight of polyesters is inversely correlated-In silicodesign and pathway analysis of bio-polyesters from low-cost carbon-feedstocks

Bioaerosols represent up to 15–25% of PM by mass, but there is currently no assessment of their impact on Oxidative Potential (OP), or capacity of particulate matter (PM) to produce damaging oxidative reactions in the human lungs. Here, the OP of selected bioaerosols (bacteria cells vs fungal spores) was assessed through the cell-free DTT assay. Results show that bioaerosols induce Reactive Oxygen Species (ROS) production, varying along the microorganism type, species, and concentration. Fungal spores show up to 10 times more ROS generation than bacterial cells. At the highest concentrations, fungal spores present as much oxidative reactivity as the most redox-active airborne chemicals (Copper, Naphtoquinone). Moreover, bioaerosols substantially influence OP of ambient PM and that of its chemical constituents: in presence of A. fumigatus spores, the OP of Cu/NQ is increased by a factor of 2 to 5, whereas, 104 and 105 S. epidermidis bacterial cells.mL−1 halves the OP of Cu/NQ. Finally, viable and gamma-rays-killed model bioaerosols present similar oxidative reactivity, suggesting a metabolism-independent cellular mechanism. These results reveal the importance of bioaerosols for PM reactivity. PM toxicity can be modified due to bioaerosols contribution or by their ability to modulate the OP of toxic chemicals present in PM.

Objective The purpose of this study was to examine the relationship between dynapenia and metabolic risk factors in obese and nonobese older adults. Methods A total of 1453 men and women (age ≥70 years) from the Lifestyle Interventions and Independence for Elders (LIFE) Study were categorized as (1) nondynapenic/nonobese (NDYN-NO), (2) dynapenic/nonobese (DYN-NO), (3) nondynapenic/obese (NDYN-O), or (4) dynapenic/obese (DYN-O), based on muscle strength (Foundation for the National Institute of Health criteria) and body mass index. Dependent variables were blood lipids, fasting glucose, blood pressure, presence of at least 3 metabolic syndrome (MetS) criteria, and other chronic conditions. Results A significantly higher likelihood of having abdominal obesity criteria in NDYN-NO compared with DYN-NO groups (55.6 vs 45.1%, P ≤ .01) was observed. Waist circumference also was significantly higher in obese groups (DYN-O = 114.0 ± 12.9 and NDYN-O = 111.2 ± 13.1) than in nonobese (NDYN-NO = 93.1 ± 10.7 and DYN-NO = 92.2 ± 11.2, P ≤ .01); and higher in NDYN-O compared with DYN-O ( P = .008). Additionally, NDYN-O demonstrated higher diastolic blood pressure compared with DYN-O (70.9 ± 10.1 vs 67.7 ± 9.7, P ≤ .001). No significant differences were found across dynapenia and obesity status for all other metabolic components ( P > .05). The odds of having MetS or its individual components were similar in obese and nonobese, combined or not with dynapenia (nonsignificant odds ratio [95% confidence interval]). Conclusion Nonobese dynapenic older adults had fewer metabolic disease risk factors than nonobese and nondynapenic older adults. Moreover, among obese older adults, dynapenia was associated with lower risk of meeting MetS criteria for waist circumference and diastolic blood pressure. Additionally, the presence of dynapenia did not increase cardiometabolic disease risk in either obese or nonobese older adults.

In the coupled aerobic−anoxic nitrous decomposition operation (CANDO), nitrogen removal occurs in two bioreactors: in the first, ammonia is oxidized to nitrite; in the second, nitrite is reduced to N2O for use as a biogas oxidant. We describe here a N2O-producing Defluviicoccus-dominated microbial community that alternately accumulates glycogen and polyhydroxyalkanoate (PHA). 13C-labelled acetate experiments confirmed the role of glycogen in PHA synthesis, and a metabolic model was developed to simulate this process. Batch experiments enabled estimation of model parameters. Key anaerobic reactions are uptake of acetate and fermentation of glycogen to poly(3-hydroxybutyrate-co-3-hydrovalerate). Key anoxic transformations are growth with PHA oxidation coupled to nitrite reduction to N2O, and conversion of PHA back to glycogen. With this simple model, we predicted and confirmed improved bioreactor performance at higher nitrogen loading rates. The model suggests strategies to either maximize N2O production or limit N2O emissions in systems designed for biological nutrient removal.

To evaluate the extent of variability in functional responses in participants in the Lifestyle Interventions and Independence for Elders (LIFE) study and to identify the relative contributions of intervention adherence, physical activity, and demographic and health characteristics to this variability.Secondary analysis.Multicenter institutions.A volunteer sample (N=1635) of sedentary men and women aged 70 to 89 years who were able to walk 400m but had physical limitations, defined as a Short Physical Performance Battery (SPPB) score of ≤9.Moderate-intensity physical activity (n=818) consisting of aerobic, resistance, and flexibility exercises performed both center-based (2times/wk) and home-based (3-4times/wk) sessions or health education program (n=817) consisting of weekly to monthly workshops covering relevant health information.Physical function (gait speed over 400m) and lower extremity function (SPPB score) assessed at baseline and 6, 12, and 24 months.Greater baseline physical function (gait speed, SPPB score) was negatively associated with change in gait speed (regression coefficient β=-.185; P.001) and change in SPPB score (β=-.365; P.001), whereas higher number of steps per day measured by accelerometry was positively associated with change in gait speed (β=.035; P.001) and change in SPPB score (β=.525; P.001). Other baseline factors associated with positive change in gait speed and/or SPPB score include younger age (P.001), lower body mass index (P.001), and higher self-reported physical activity (P=.002).Several demographic and physical activity-related factors were associated with the extent of change in functional outcomes in participants in the LIFE study. These factors should be considered when designing interventions for improving physical function in older adults with limited mobility.

Problem statement: Colleges and universities place more emphasis on student retention rates than ever before. Educational institutions are intensifying efforts to discourage student departure and preserve their established student base. Economic pressures that bear heavily on academic administration make such efforts highly critical for institutional success. Research on this vital issue is especially important due to the vigorous competition among college and universities to recruit students and maintain enrollment levels. This pressure is heightened by the fact that it costs more to attract students than it does to retain them. Approach: This study uses institutional-based data to examine student attrition levels with the intent to identify their chief determinants and provide the foundation for post-secondary institutions to explore the viability of their own retention programs. Discriminant analysis is used to distinguish those schools that exhibit a higher degree of success in retaining student enrollments from those who suffer higher departure trends. Results: Tuition, student/teacher ratio and the amount of dollar aid offered the students all play substantial roles in encouraging persistence. The acceptance rate and enrollment levels were found to provide less discriminatory power. Conclusion: Students are influenced by the personal attention they receive and the manner in which their chosen institution of higher education caters to their individual needs, problems and concerns. Colleges and universities concerned with student retention would benefit from concentrated programs designed to provide individualized student services that address immediate student needs.

Using a permanent income hypothesis approach and an income-giving status interaction effect, a double hurdle model provides evidence of significant differences from the impact of household income and various household characteristics on both a household's likelihood of giving and its level of giving to religion, charity, education, others outside the household, and politics. An analysis of resulting income elasticity estimates revealed that households consider religious giving a necessity good at all levels of income, while other categories of giving are generally found to be luxury goods. Further, those who gave to religion were found to give more to education and charity then those not giving to religion, and higher education households were more likely to give to religion than households with less education. This analysis suggests that there may be more to religious giving behavior than has been assumed in prior studies and underscores the need for further research into the motivation for religious giving. Specifically, these findings point to an enduring, internal motivation for giving rather than an external, “What do I get for what I give,” motive.