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Vitrimers are a new class of materials that consist of chemically cross-linked networks that engage in thermoactivated associative exchange reactions. These exchange reactions can impart malleability, healing, and recyclability properties to thermosets. In this study, a one-step protocol to prepare linear lowdensity polyethylene (LLDPE) vitrimer-like materials with disulfide exchange bonds via reactive blending is presented. The cross-linking reaction of maleic anhydride-grafted-linear low-density polyethylene (LLDPE-MAH) and 4,40-dithiodianiline was followed in a torque rheometer. The degree of MAHfunctionalization and its impact on the melt rheology, dynamic mechanical properties, and thermal properties of the vitrimer was studied. The crosslinked LLDPE possessed a mostly elastic behavior, with storage modulus (G0) higher than loss modulus (G00) in the entire frequency range. The complex viscosity of cross-linked LLDPE at high frequencies (>100 rad/s) was comparable to the thermoplastic LLDPE. The MAH-groups and formation of cross-links decreased the degree of crystallinity, which led to a decrease in the storage modulus at a temperature of 35°C. The storage modulus and dimensional stability of the materials improved with cross-linking density, suggesting potential benefits of LLDPE vitrimers in secondary manufacturing processes. Finally, the reprocessing ability was demonstrated via internal mixing and the rheological and mechanical properties were retained. [ABSTRACT FROM AUTHOR]

Summary: The objective of this study was to characterise the nutritional potential of leaves and identify a diversity centre with low cyanide and high nutrient content among 178 Latin American cassava genotypes. This field‐based collection represents the seven diversity centres, held at The International Center for Tropical Agriculture (CIAT Palmira, Colombia) by the Cassava Program. The cyanide, all‐trans‐β‐carotene and lutein concentrations in cassava leaves ranged from 346 to 7484 ppm dry basis (db), from 174–547 μg g−1 db and 15–181 μg g−1 db, respectively. Cassava leaves also showed significant levels of essential amino acids leucine, lysine, phenylalanine, valine and threonine, and average total protein content of 26.24 g 100 g−1 db. Among seven diversity centres, South American rainforest group showed low cyanide and high carotene content in leaves. In addition, VEN77 and PAN51 genotypes stood out for having low cyanide in leaves and roots and high carotene in leaves. This genetic diversity can be used to select high potential progenitors for breeding purposes. [ABSTRACT FROM AUTHOR]

Asthma is a chronic respiratory disease with complex etiology. Adverse childhood experiences (ACEs) have been linked to asthma in adulthood. Underlying potential mechanisms for the ACE-asthma relationship include stress-induced inflammatory pathways and immune dysregulation. We conducted a cross-sectional secondary data analysis of the 2013 Alberta ACE Survey to explore the relationship between latent ACE factors and self-reported adult asthma. We evaluated the underlying correlation structure among eight different ACEs using exploratory factor analysis. We conducted a logistic regression model to evaluate whether ACE factors retained from the factor analysis predicted self-reported asthma in adulthood. Results were reported as odds ratios (ORs) with 95% confidence intervals (CIs). We analyzed ACE survey results from 1207 participants. Factor analysis yielded four ACE latent factors: factor 1/relational violence, factor 2/negative home environment, factor 3/illness at home, and factor 4/sexual abuse. Results of the logistic regression showed that experiencing sexual abuse (OR: 3.23; 95% CI: 1.89, 5.23), relational violence (OR: 1.99; 95% CI: 1.17, 3.38), and being exposed to a negative home environment (OR: 1.86; 95% CI: 1.03, 3.35) were predictive of a diagnosis of asthma in adulthood, whereas living in a household with someone experiencing illness did not show an effect (OR: 1.38; 95% CI: 0.75, 2.56). Factor analysis provides an effectual approach to understand the long-term impact of ACEs on respiratory health. Our findings have important implications to understand the developmental origins of asthma in adulthood and inform interventions aimed at reducing the lasting negative impact of childhood adversities on future respiratory health. [ABSTRACT FROM AUTHOR]

Canadian lung transplant centers currently use a subjective and dichotomous "Status" ranking to prioritize waitlisted patients for lung transplantation. The lung allocation score (LAS) is an objective composite score derived from clinical parameters associated with both waitlist and post‐transplant survival. We performed a retrospective cohort study to determine whether clinical judgment (Status) or LAS better predicted waitlist mortality. All adult patients listed for lung transplantation between 2007 and 2012 at three Canadian lung transplant programs were included. Status and LAS were compared in their ability to predict waitlist mortality using Cox proportional hazards models and C‐statistics. Status and LAS were available for 1122 patients. Status 2 patients had a higher LAS compared to Status 1 patients (mean 40.8 (4.4) vs 34.6 (12.5), P =.0001). Higher LAS was associated with higher risk of waitlist mortality (HR 1.06 per unit LAS, 95% CI 1.05, 1.07, P <.001). LAS predicted waitlist mortality better than Status (C‐statistic 0.689 vs 0.674). Patients classified as Status 2 and LAS ≥ 37 had the worst survival awaiting transplant, HR of 8.94 (95% CI 5.97, 13.37). LAS predicted waitlist mortality better than Status; however, the best predictor of waitlist mortality may be a combination of both LAS and clinical judgment. [ABSTRACT FROM AUTHOR]

Background: An accurate assessment of the adequacy of prenatal care utilization is critical to inform the relationship between prenatal care and pregnancy outcomes. This systematic review critically appraises the evidence on measurement properties of prenatal care utilization indices and provides recommendations about which index is the most useful for this purpose.Methods: MEDLINE, EMBASE, CINAHL, and Web of Science were systematically searched from database inception to October 2018 using keywords related to indices of prenatal care utilization. No language restrictions were imposed. Studies were included if they evaluated the reliability, validity, or responsiveness of at least one index of adequacy of prenatal care utilization. We used the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. We conducted an evidence synthesis using predefined criteria to appraise the measurement properties of the indices.Results: From 2664 studies initially screened, 13 unique studies evaluated the measurement properties of at least one index of prenatal care utilization. Most of the indices of adequacy of prenatal care currently used in research and clinical practice have been evaluated for at least some form of reliability and/or validity. Evidence about the responsiveness to change of these indices is absent from these evaluations. The Adequacy Perinatal Care Utilization Index (APNCUI) and the Kessner Index are supported by moderate evidence regarding their reliability, predictive and concurrent validity.Conclusion: The scientific literature has not comprehensively reported the measurement properties of commonly used indices of prenatal care utilization, and there is insufficient research to inform the choice of the best index. Lack of strong evidence about which index is the best to measure prenatal care utilization has important implications for tracking health care utilization and for formulating prenatal care recommendations. [ABSTRACT FROM AUTHOR]