1,106 research outputs found

    Nature\u27s Assembly Line Logic for Natural Products

    Get PDF
    Nature fashions a very large number of diverse products (molecular weights ranging from ca. 200 to 2000 daltons) from simple monomeric metabolites used in primary metabolism. These include polyketide scaffolds generated from the simple C₃ malonyl CoA and C₄ methylmalonyl CoA monomers and nonribosomal peptides made from both the 20 proteinogenic amino acids and dozens of nonpoteinogenic amino acids.¹ A large family of terpenoid skeletons are built from the Δ²- and Δ³-alkene isomers of the biological isoprene monomer, isoprenyl-pyrophosphate.

    Trace CO2 capture by an ultramicroporous physisorbent with low water affinity.

    Get PDF
    CO2 accumulation in confined spaces represents an increasing environmental and health problem. Trace CO2 capture remains an unmet challenge because human health risks can occur at 1000 parts per million (ppm), a level that challenges current generations of chemisorbents (high energy footprint and slow kinetics) and physisorbents (poor selectivity for CO2, especially versus water vapor, and/or poor hydrolytic stability). Here, dynamic breakthrough gas experiments conducted upon the ultramicroporous material SIFSIX-18-Ni-β reveal trace (1000 to 10,000 ppm) CO2 removal from humid air. We attribute the performance of SIFSIX-18-Ni-β to two factors that are usually mutually exclusive: a new type of strong CO2 binding site and hydrophobicity similar to ZIF-8. SIFSIX-18-Ni-β also offers fast sorption kinetics to enable selective capture of CO2 over both N2 (S CN) and H2O (S CW), making it prototypal for a previously unknown class of physisorbents that exhibit effective trace CO2 capture under both dry and humid conditions

    Design and Psychometrics for New Measures of Health-Related Quality of Life in Adults with Type 1 Diabetes: Type 1 Diabetes and Life (T1DAL)

    Get PDF
    AIMS: To use a three-phase process to develop and validate new self-report measures of diabetes-specific health-related quality of life (HRQOL) for adults with type 1 diabetes. We report on four versions of the Type 1 Diabetes and Life (T1DAL) measure for people age 18-25, 26-45, 46-60, and over 60 years. METHODS: We first conducted qualitative interviews to guide measure creation, then piloted the draft measures. We evaluated psychometric properties at six T1D Exchange Clinic Network sites via completion of T1DAL and validated measures of related constructs. Participants completed the T1DAL again in 4-6 weeks. We used psychometric data to reduce each measure to 23-27 items in length. Finally, we obtained participant feedback on the final measures. RESULTS: The T1DAL-Adult measures demonstrated good internal consistency (α=0.85-0.88) and test-retest reliability (r=0.77-0.87). Significant correlations with measures of general quality of life, generic and diabetes-specific HRQOL, diabetes burden, self-management, and glycemic control demonstrated validity. Factor analyses yielded 4-5 subscales per measure. Participants were satisfied with the final measures and reported they took 5-10 minutes to complete. CONCLUSIONS: The strong psychometric properties of the newly developed self-report T1DAL measures for adults with type 1 diabetes make them appropriate for use in clinical research and care

    Implementation of Basal-Bolus Therapy in Type 2 Diabetes:A Randomized Controlled Trial Comparing Bolus Insulin Delivery Using an Insulin Patch with an Insulin Pen

    Get PDF
    Background: Barriers to mealtime insulin include complexity, fear of injections, and lifestyle interference. This multicenter, randomized controlled trial evaluated efficacy, safety, and self-reported outcomes in adults with type 2 diabetes, inadequately controlled on basal insulin, initiating and managing mealtime insulin with a wearable patch versus an insulin pen. Methods: Adults with type 2 diabetes (n = 278, age: 59.2 +/- 8.9 years), were randomized to patch (n = 139) versus pen (n = 139) for 48 weeks, with crossover at week 44. Baseline insulin was divided 1:1 basal: bolus. Using a pattern-control logbook, subjects adjusted basal and bolus insulin weekly using fasting and premeal glucose targets. Results: Glycated hemoglobin (HbA1c) change (least squares mean +/- standard error) from baseline to week 24 (primary endpoint) improved (P \u3c 0.0001) in both arms, -1.7% +/- 0.1% and -1.6% +/- 0.1% for patch and pen (-18.6 +/- 1.1 and -17.5 +/- 1.1 mmol/mol), and was maintained at 44 weeks. The coefficient of variation of 7-point self-monitoring blood glucose decreased more (P = 0.02) from baseline to week 44 for patch versus pen. There were no differences in adverse events, including hypoglycemia (three severe episodes per arm), and changes in weight and insulin doses. Subject-reported treatment satisfaction, quality of life, experience ratings at week 24, and device preferences at week 48 significantly favored the patch. Most health care providers preferred patch for mealtime insulin. Conclusions: Bolus insulin delivered by patch and pen using an algorithm-based weekly insulin dose titration significantly improved HbA1c in adults with type 2 diabetes, with improved subject and health care provider experience and preference for the patch

    Search for the Standard Model Higgs Boson with the OPAL Detector at LEP

    Full text link
    This paper summarises the search for the Standard Model Higgs boson in e+e- collisions at centre-of-mass energies up to 209 GeV performed by the OPAL Collaboration at LEP. The consistency of the data with the background hypothesis and various Higgs boson mass hypotheses is examined. No indication of a signal is found in the data and a lower bound of 112.7GeV/C^2 is obtained on the mass of the Standard Model Higgs boson at the 95% CL.Comment: 51 pages, 21 figure

    Search for R-Parity Violating Decays of Scalar Fermions at LEP

    Full text link
    A search for pair-produced scalar fermions under the assumption that R-parity is not conserved has been performed using data collected with the OPAL detector at LEP. The data samples analysed correspond to an integrated luminosity of about 610 pb-1 collected at centre-of-mass energies of sqrt(s) 189-209 GeV. An important consequence of R-parity violation is that the lightest supersymmetric particle is expected to be unstable. Searches of R-parity violating decays of charged sleptons, sneutrinos and squarks have been performed under the assumptions that the lightest supersymmetric particle decays promptly and that only one of the R-parity violating couplings is dominant for each of the decay modes considered. Such processes would yield final states consisting of leptons, jets, or both with or without missing energy. No significant single-like excess of events has been observed with respect to the Standard Model expectations. Limits on the production cross- section of scalar fermions in R-parity violating scenarios are obtained. Constraints on the supersymmetric particle masses are also presented in an R-parity violating framework analogous to the Constrained Minimal Supersymmetric Standard Model.Comment: 51 pages, 24 figures, Submitted to Eur. Phys. J.

    Representations of sport in the revolutionary socialist press in Britain, 1988–2012

    Get PDF
    This paper considers how sport presents a dualism to those on the far left of the political spectrum. A long-standing, passionate debate has existed on the contradictory role played by sport, polarised between those who reject it as a bourgeois capitalist plague and those who argue for its reclamation and reformation. A case study is offered of a political party that has consistently used revolutionary Marxism as the basis for its activity and how this party, the largest in Britain, addresses sport in its publications. The study draws on empirical data to illustrate this debate by reporting findings from three socialist publications. When sport did feature it was often in relation to high profile sporting events with a critical tone adopted and typically focused on issues of commodification, exploitation and alienation of athletes and supporters. However, readers’ letters, printed in the same publications, revealed how this interpretation was not universally accepted, thus illustrating the contradictory nature of sport for those on the far left

    A critical engagement with theological education in Africa

    Get PDF
    The higher education landscape has arguably become one of the most arduous to traverse. More so in the African context, where a host of variables continiously challenge educators to reflect critically on their philosophies and practices as they engage an ever-changing audience. In this book, a critical engagement with theological education in Africa is offered. As the book originates from South Africa, it is presented as a South African perspective, although contributors are situated accross the African continent and abroad. The common denominator is that all contributers are, in some way or another, invested in theological education in Africa. The main contribution of this collaborative work is to be sought in the insights it offers on four main areas of theological education: A historical and current orientation on theological edcuation in Africa, some paradigm shifts in theological education in Africa, ministerial formation needs versus theological education challenges, and a critical reflection on elective models and methods. The book presents the original and innovative research of scholars for fellow scholars involved in theological higher education as it is grounded in the respective fields of interest of each contributor. It contributes to a better understanding of the complex African theological higher education landscape that is also mindful of post-COVID-19 realities. Methodologically the work draws on a combination of methods, including literature studies, empirical work, and in some cases sectional offerings from doctoral studies, as indicated in the various chapters

    Measurements of Transverse Energy Flow in Deep-Inelastic Scattering at HERA

    Full text link
    Measurements of transverse energy flow are presented for neutral current deep-inelastic scattering events produced in positron-proton collisions at HERA. The kinematic range covers squared momentum transfers Q^2 from 3.2 to 2,200 GeV^2, the Bjorken scaling variable x from 8.10^{-5} to 0.11 and the hadronic mass W from 66 to 233 GeV. The transverse energy flow is measured in the hadronic centre of mass frame and is studied as a function of Q^2, x, W and pseudorapidity. A comparison is made with QCD based models. The behaviour of the mean transverse energy in the central pseudorapidity region and an interval corresponding to the photon fragmentation region are analysed as a function of Q^2 and W.Comment: 26 pages, 8 figures, submitted to Eur. Phys.
    corecore