248 research outputs found

    Prognostic Importance of Dyspnea for Cardiovascular Outcomes and Mortality in Persons without Prevalent Cardiopulmonary Disease: The Atherosclerosis Risk in Communities Study

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    The relationship between dyspnea and incident heart failure (HF) and myocardial infarction (MI) among patients without previously diagnosed cardiopulmonary disease is unclear. We studied the prognostic relevance of self-reported dyspnea for cardiovascular outcomes and all-cause mortality in persons without previously diagnosed cardiopulmonary disease

    Complete set of polarization transfer coefficients for the 3He(p,n){}^{3}{\rm He}(p,n) reaction at 346 MeV and 0 degrees

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    We report measurements of the cross-section and a complete set of polarization transfer coefficients for the 3He(p,n){}^{3}{\rm He}(p,n) reaction at a bombarding energy TpT_p = 346 MeV and a reaction angle θlab\theta_{\rm lab} = 0∘0^{\circ}. The data are compared with the corresponding free nucleon-nucleon values on the basis of the predominance of quasi-elastic scattering processes. Significant discrepancies have been observed in the polarization transfer DLL(0∘)D_{LL}(0^{\circ}), which are presumably the result of the three-proton TT = 3/2 resonance. The spin--parity of the resonance is estimated to be 1/2−1/2^-, and the distribution is consistent with previous results obtained for the same reaction at TpT_p = 48.8 MeV.Comment: 4 figures, Accepted for publication in Physical Review

    Socioeconomic status and modification of atherosclerotic cardiovascular disease risk prediction: Epidemiological analysis using data from the Atherosclerosis Risk In Communities study

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    OBJECTIVE: Examine whether the relationship between the pooled cohort equations (PCE) predicted 10-year risk for atherosclerotic cardiovascular disease (ASCVD) and absolute risk for ASCVD is modified by socioeconomic status (SES). DESIGN: Population-based longitudinal cohort study-Atherosclerosis Risk in Communities (ARIC)-investigating the development of cardiovascular disease across demographic subgroups. SETTING: Four communities in the USA-Forsyth County, North Carolina, Jackson, Mississippi, suburbs of Minneapolis, Minnesota and Washington County, Maryland. PARTICIPANTS: We identified 9782 ARIC men and women aged 54-73 without ASCVD at study visit 4 (1996-1998). PRIMARY OUTCOME MEASURES: Risk ratio (RR) differences in 10-year incident hospitalisations or death for ASCVD by SES and PCE predicted 10-year ASCVD risk categories to assess for risk modification. SES measures included educational attainment and census-tract neighbourhood deprivation using the Area Deprivation Index. PCE risk categories were 0%-5%, \u3e5%-10%, \u3e10%-15% and \u3e15%. SES as a prognostic factor to estimate ASCVD absolute risk categories was further investigated as an interaction term with the PCE. RESULTS: ASCVD RRs for participants without a high school education (referent college educated) increased at higher PCE estimated risk categories and was consistently \u3e1. Results indicate education is both a risk modifier and delineates populations at higher ASCVD risk independent of PCE. Neighbourhood deprivation did modify association but was less consistent in direction of effect. However, for participants residing in the most deprived neighbourhoods (referent least deprived neighbourhoods) with a PCE estimated risk \u3e10%-15%, risk was significantly elevated (RR 1.65, 95% CI 1.05 to 2.59). Education and neighbourhood deprivation inclusion as an interaction term on the PCE risk score was statistically significant (likelihood ratio p≤0.0001). CONCLUSIONS: SES modifies the association between PCE estimated risk and absolute risk of ASCVD. SES added into ASCVD risk prediction models as an interaction term may improve our ability to predict absolute ASCVD risk among socially disadvantaged populations

    STUDI KEKRISTALAN BARIUM STRONTIUM TITANAT (Ba0,5Sr0,5TiO3) YANG DIDOPING MAGNESIUM DENGAN METODE SPIN COATING

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    STUDI KEKRISTALAN BARIUM STRONTIUM TITANAT (Ba0,5Sr0,5TiO3) YANG DIDOPING MAGNESIUM DENGAN METODE SPIN COATING. Lapisan tipis Ba0,5Sr0,5TiO3 (BST) yang didoping Mg telah dibuat dengan metode Chemical Solution Deposition yang disiapkan dengan spin coating. Deposisi lapisan tipis BST pada substrat Si menggunakan spin coater dengan kecepatan putar 3000 rpmselama 30 detik. Suhu annealing yang digunakan pada penelitian ini adalah 800 oC. Karakterisasi, komposisi dan kekristalan lapisan tipis BST dilakukan menggunakan X-Ray Fluorosence (XRF) dan X-Ray Diffraction (XRD). Hasil XRF menunjukkan bahwa unsur-unsur pembentuk BST dan doping Mg telah terdeposit pada substrat Si. Hasil analisis Rietveld pada pola difraksi sinar X menunjukkan bahwa doping Mg mempengaruhi struktur kristal dan parameter kisi. Parameter kisi untuk BST murni dan BST yang didoping Mg 1% sama dengan data PDF-ICDD yaitu 3,947 Ã…. Sedangkan untuk BST yang didoping Mg 2 % dan 4 % sebesar 3,948

    Structural variability of E. coli thioredoxin captured in the crystal structures of single-point mutants

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    Thioredoxin is a ubiquitous small protein that catalyzes redox reactions of protein thiols. Additionally, thioredoxin from E. coli (EcTRX) is a widely-used model for structure-function studies. In a previous paper, we characterized several single-point mutants of the C-terminal helix (CTH) that alter global stability of EcTRX. However, spectroscopic signatures and enzymatic activity for some of these mutants were found essentially unaffected. A comprehensive structural characterization at the atomic level of these near-invariant mutants can provide detailed information about structural variability of EcTRX. We address this point through the determination of the crystal structures of four point-mutants, whose mutations occurs within or near the CTH, namely L94A, E101G, N106A and L107A. These structures are mostly unaffected compared with the wild-type variant. Notably, the E101G mutant presents a large region with two alternative traces for the backbone of the same chain. It represents a significant shift in backbone positions. Enzymatic activity measurements and conformational dynamics studies monitored by NMR and molecular dynamic simulations show that E101G mutation results in a small effect in the structural features of the protein. We hypothesize that these alternative conformations represent samples of the native-state ensemble of EcTRX, specifically the magnitude and location of conformational heterogeneity

    Reduction of sulfenic acids by ascorbate in proteins, connecting thiol-dependent to alternative redox pathways

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    Sulfenic acids are the primary product of thiol oxidation by hydrogen peroxide and other oxidants. Several aspects of sulfenic acid formation through thiol oxidation were established recently. In contrast, the reduction of sulfenic acids is still scarcely investigated. Here, we characterized the kinetics of the reduction of sulfenic acids by ascorbate in several proteins. Initially, we described the crystal structure of our model protein (Tsa2-C170S). There are other Tsa2 structures in distinct redox states in public databases and all of them are decamers, with the peroxidatic cysteine very accessible to reductants, convenient features to investigate kinetics. We determined that the reaction between Tsa2-C170S-Cys-SOH and ascorbate proceeded with a rate constant of 1.40 ± 0.08 × 103 M−1 s−1 through a competition assay developed here, employing 2,6–dichlorophenol-indophenol (DCPIP). A series of peroxiredoxin enzymes (Prx6 sub family) were also analyzed by this competition assay and we observed that the reduction of sulfenic acids by ascorbate was in the 0.4–2.2 × 103 M−1 s−1 range. We also evaluated the same reaction on glyceraldehyde 3-phosphate dehydrogenase and papain, as the reduction of their sulfenic acids by ascorbate were reported previously. Once again, the rate constants are in the 0.4–2.2 × 103 M−1 s−1 range. We also analyzed the reduction of Tsa2-C170S-SOH by ascorbate by a second, independent method, following hydrogen peroxide reduction through a specific electrode (ISO-HPO-2, World Precision Instruments) and employing a bi-substrate, steady state approach. The was 7.4 ± 0.07 × 103 M−1 s−1, which was in the same order of magnitude as the value obtained by the DCPIP competition assay. In conclusion, our data indicates that reduction of sulfenic acid in various proteins proceed at moderate rate and probably this reaction is more relevant in biological systems where ascorbate concentrations are high

    Reactive hyperemia is associated with adverse clinical outcomes in heart failure

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    © 2016 Elsevier Inc. All rights reserved. Introduction Impaired endothelial function, as assessed by brachial artery flow-mediated dilation (FMD), is an established risk factor for cardiovascular events. FMD is impaired in heart failure (HF) patients, but less is known about hyperemic brachial artery flow. We investigated the relationship between FMD and hyperemic flow with adverse clinical outcomes in HF patients. Methods Brachial artery FMD and hyperemic flow were assessed in 156 patients (70.5 % Male; 45.5% Caucasian; mean age (± SD) = 56.2 (±12.4) years) with HF and reduced left ventricular ejection fraction (LVEF). Cox proportional hazard models were used to assess the potential explanatory association of FMD and hyperemic flow with the composite outcome of death or cardiovascular hospitalization over a median 5-year follow-up period. Results Both FMD and hyperemic flow were negatively correlated with age, but unrelated to sex, race, body mass index, LVEF or N-terminal pro-B-Type natriuretic peptide (NT-ProBNP). Reduced hyperemic flow, but not FMD, was associated with an increased risk of death or cardiac hospitalization after controlling for traditional risk factors. Conclusion The association of reduced hyperemic flow with increased risk of adverse clinical outcomes suggests that micro-vascular function may be an important prognostic marker in patients with HF
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