42 research outputs found

    A copper-catalyzed asymmetric oxime propargylation enables the synthesis of the gliovirin tetrahydro-1,2-oxazine core

    Get PDF
    The bicyclic tetrahydro-1,2-oxazine subunit of gliovirin is synthesized through a diastereoselective copper-catalyzed cyclization of an N-hydroxyamino ester. Oxidative elaboration to the fully functionalized bicycle was achieved through a series of mild transformations. Central to this approach was the development of the first catalytic, enantioselective propargylation of an oxime to furnish a key N-hydroyxamino ester intermediate

    Long-Term Changes in Physical Activity Following a One-Year Home-Based Physical Activity Counseling Program in Older Adults with Multiple Morbidities

    Get PDF
    This study assessed the sustained effect of a physical activity (PA) counseling intervention on PA one year after intervention, predictors of sustained PA participation, and three classes of post-intervention PA trajectories (improvers, maintainers, and decliners) in 238 older Veterans. Declines in minutes of PA from 12 to 24 months were observed for both the treatment and control arms of the study. PA at 12 months was the strongest predictor of post-intervention changes in PA. To our surprise, those who took up the intervention and increased PA levels the most, had significant declines in post-intervention PA. Analysis of the three post-intervention PA trajectories demonstrated that the maintenance group actually reflected a group of nonresponders to the intervention who had more comorbidities, lower self-efficacy, and worse physical function than the improvers or decliners. Results suggest that behavioral counseling/support must be ongoing to promote maintenance. Strategies to promote PA appropriately to subgroups of individuals are needed

    Effector-Triggered Immune Response in Arabidopsis thaliana Is a Quantitative Trait

    Get PDF
    We identified loci responsible for natural variation in Arabidopsis thaliana (Arabidopsis) responses to a bacterial pathogen virulence factor, HopAM1. HopAM1 is a type III effector protein secreted by the virulent Pseudomonas syringae strain Pto DC3000. Delivery of HopAM1 from disarmed Pseudomonas strains leads to local cell death, meristem chlorosis, or both, with varying intensities in different Arabidopsis accessions. These phenotypes are not associated with differences in bacterial growth restriction. We treated the two phenotypes as quantitative traits to identify host loci controlling responses to HopAM1. Genome-wide association (GWA) of 64 Arabidopsis accessions identified independent variants highly correlated with response to each phenotype. Quantitative trait locus (QTL) mapping in a recombinant inbred population between Bur-0 and Col-0 accessions revealed genetic linkage to regions distinct from the top GWA hits. Two major QTL associated with HopAM1-induced cell death were also associated with HopAM1-induced chlorosis. HopAM1-induced changes in Arabidopsis gene expression showed that rapid HopAM1-dependent cell death in Bur-0 is correlated with effector-triggered immune responses. Studies of the effect of mutations in known plant immune system genes showed, surprisingly, that both cell death and chlorosis phenotypes are enhanced by loss of EDS1, a regulatory hub in the plant immune-signaling network. Our results reveal complex genetic architecture for response to this particular type III virulence effector, in contrast to the typical monogenic control of cell death and disease resistance triggered by most type III effectors

    What difference does a thiophene make? Evaluation of a 4,4′-bis(thiophene) functionalised 2,2′-bipyridyl copper(I) complex in a dye-sensitized solar cell

    Get PDF
    AbstractThe synthesis of a 4,4′-bis(2-thienyl-5-carboxylic acid) functionalised 2,2′-bipyridine ligand and corresponding copper(I) complex is described and its application in a dye-sensitized solar cell (DSSC) is studied. The positioning of the thiophene groups appears favourable from DFT analysis and a best efficiency of 1.41% was obtained with this dye, for a 0.3 cm2 cell area DSSC. Two absorbance bands are observed in the electronic absorption spectrum of the copper(I) complex at 316 nm and 506 nm, with ε values of 50,000 M−1 cm−1 and 9030 M−1 cm−1, respectively. Cyclic voltammetry and electrochemical impedance spectroscopy are also used to provide a detailed analysis of the dye and assess its functionality in a DSSC

    What difference does a thiophene make? Evaluation of a 4,4′-bis(thiophene) functionalised 2,2′-bipyridyl copper(I) complex in a dye-sensitized solar cell

    Get PDF
    The synthesis of a 4,4′-bis(2-thienyl-5-carboxylic acid) functionalised 2,2′-bipyridine ligand and corresponding copper(I) complex is described and its application in a dye-sensitized solar cell (DSSC) is studied. The positioning of the thiophene groups appears favourable from DFT analysis and a best efficiency of 1.41% was obtained with this dye, for a 0.3 cm2 cell area DSSC. Two absorbance bands are observed in the electronic absorption spectrum of the copper(I) complex at 316 nm and 506 nm, with ε values of 50,000 M−1 cm−1 and 9030 M−1 cm−1, respectively. Cyclic voltammetry and electrochemical impedance spectroscopy are also used to provide a detailed analysis of the dye and assess its functionality in a DSSC

    A copper-catalyzed asymmetric oxime propargylation enables the synthesis of the gliovirin tetrahydro-1,2-oxazine core

    Get PDF
    The bicyclic tetrahydro-1,2-oxazine subunit of gliovirin is synthesized through a diastereoselective copper-catalyzed cyclization of an N-hydroxyamino ester. Oxidative elaboration to the fully functionalized bicycle was achieved through a series of mild transformations. Central to this approach was the development of the first catalytic, enantioselective propargylation of an oxime to furnish a key N-hydroyxamino ester intermediate

    III.—Blind Trilobites

    No full text

    Comparing Survival Following Hip Fracture Repair in VHA and Non-VHA Facilities

    No full text
    Introduction: Although postsurgical outcomes are similar between Veterans Health Administration (VHA) and non-VHA hospitals for many procedures, no studies have compared 30-day and 1-year survival following hip fracture repair. Therefore, this study compared survival of veterans aged 65 years and older treated in VHA hospitals with a propensity-matched cohort of Medicare beneficiaries in non-VHA hospitals. Materials and Methods: Retrospective cohort study of 1894 hip fracture repair patients in VHA or non-VHA hospitals between 2003 and 2005. Current Procedural Terminology codes identified 3542 male patients aged > 65 years who had hip fracture repair between 2003 and 2005 in the Veterans Affairs’ National Surgical Quality Improvement Program database. The Medicare comparison sample was drawn from 2003 to 2005 Medicare Part A inpatient hospital claims files. To create comparable VHA and Medicare cohorts, patients were propensity score matched on age, admission source (community vs. nursing home), repair type, comorbidity index, race, year, and region. Thirty-day and 1-year survival after surgery were compared between cohorts after further adjustment for selected comorbidities, year of surgery, and pre- and postsurgical length of hospital stay using logistic regression. Results: Odds of survival were significantly better in the Medicare than the VHA cohort at 30 days (1.68, 95% CI 1.15-2.44) and 1 year (1. 35 , 95% CI 1.08-1.69). Conclusion: Medicare beneficiaries with hip fracture repair in non-VHA hospitals had better survival than veterans in VHA hospitals. Whether this is driven by unobserved patient characteristics or systematic care differences is unknown
    corecore