96 research outputs found
Bleaching and diffusion dynamics in optofluidic dye lasers
We have investigated the bleaching dynamics that occur in optofluidic dye
lasers where the liquid laser dye in a microfluidic channel is locally bleached
due to optical pumping. We find that for microfluidic devices, the dye
bleaching may be compensated through diffusion of dye molecules alone. By
relying on diffusion rather than convection to generate the necessary dye
replenishment, our observation potentially allows for a significant
simplification of optofluidic dye laser device layouts, omitting the need for
cumbersome and costly external fluidic handling or on-chip microfluidic pumping
devices.Comment: 3 pages including 3 figures. Accepted for AP
Plaque in superficial femoral arteries indicates generalized atherosclerosis and vulnerability to coronary death: An autopsy study
ObjectivesRisk factors for atherosclerosis have limited ability to identify persons at high risk of coronary heart disease. Assessment of subclinical atherosclerosis in peripheral arteries might improve this limitation. We studied the relationship between atherosclerotic plaques in peripheral arteries, coronary plaques, and coronary death.MethodsPredefined segments from the left anterior descending coronary artery, the right coronary artery, bilateral carotid, and superficial femoral arteries (SFA) were obtained from 100 autopsies (20-82 years, 30 females, 27 coronary deaths). Based on microscopic examination of 4756 sections, the extension of atherosclerosis (plaque burden) and the largest plaque area in each segment were quantified.ResultsPlaque burden in all arteries increased with age and was larger in coronary death (P < .05). SFA plaques occurred later than coronary and carotid plaques. When SFA plaque had developed, coronary plaque was also present. SFA plaque (odds ratio, 95% confidence interval: 7.07 [2.40-20.81]), but not carotid plaque, was significantly associated with coronary death, also after age and gender adjustment (21.25 [5.02-89.97]). The area under the receiver operating characteristic curves for the identification of coronary death individuals was 0.72 (95% confidence interval: 0.62-0.83) for coronary plaque, and 0.80 (0.72-0.89) for SFA plaque (age and gender adjusted).ConclusionsAtherosclerosis develops slower in SFA compared with coronary and carotid arteries. In persons with plaque in the SFA, plaque is always present in the coronary arteries. In younger persons, the presence of SFA plaque indicates a generalized susceptibility to atherosclerosis and vulnerability to coronary death
Identification of weak and gender specific effects in a short 3 weeks intervention study using barley and oat mixed linkage β-glucan dietary supplements:a human fecal metabolome study by GC-MS
Introduction: Mixed-linkage (1\ue2\u86\u923),(1\ue2\u86\u924)-\uce\ub2-d-glucans (BG) reduce cholesterol level and insulin response in humans. Despite this, their role in human metabolism and a mode of action remains largely unknown. Objectives: To investigate the effects of three structurally different BG on human fecal metabolome in a full cross-over intervention using GC-MS metabolomics. Methods: Over three weeks of intervention, young healthy adults received food supplemented with BG from oat, two different BG from barley or a non-fiber control in a full cross-over design. Untargeted metabolomics and short chain fatty acid analysis was performed on day three fecal samples. ANOVA-simultaneous component analysis was applied to partition the data variation according to the study design, and PLS-DA was used to select most discriminative metabolite markers. Results: Univariate and multivariate data analysis revealed a dominating effect of inter-individual variances followed by a gender effect. Weak effects of BG intake were identified including an increased level of gamma-amino-butyrate and palmitoleic acid in males and a decreased level of enterolactone in females. Barley and oat derived BG were found to influence the human fecal metabolome differently. Barley BG increased the relative level of formate in males and isobutyrate, isovalerate, 2-methylbutyrate in females. In total 15, 3 and 11 human fecal metabolites were significantly different between control vs. BG, control vs. oat BG, and barley BG vs. oat BG, respectively. Conclusions: The study show that human fecal metabolome largely reflects individual (\ue2\u88\ubc28% variation) and gender (\ue2\u88\ubc15% variation) differences, whereas the treatment\uc2\ua0effect of the BG (\ue2\u88\ubc8% variation) only manifests in a few key metabolites (primarily by the metabolites: d-2-aminobutyric acid, palmitoleic acid, linoleic acid and 11-eicosenoic acid)
Ischemic Stroke Severity and Mortality in Patients With and Without Atrial Fibrillation
Background Our objective was to investigate stroke severity and subsequent rate of mortality among patients with and without atrial fibrillation (AF). Contemporary data on stroke severity and prognosis in patients with AF are lacking. Methods and Results Firstâtime ischemic stroke patients from the Danish Stroke Registry (January 2005âDecember 2016) were included in an observational study. Patients with AF were matched 1:1 by sex, age, calendar year, and CHA2DS2âVASc score with patients without AF. Stroke severity was determined by the Scandinavian Stroke Scale (0â58 points). The rate of death was estimated by KaplanâMeier plots and multivariable Cox regression. Among 86Â 458 identified patients with stroke, 17Â 205 had AF. After matching, 14Â 662 patients with AF and 14Â 662 patients without AF were included (51.8% women; median age, 79.6Â years [25thâ75th percentile, 71.8â86.0]). More patients with AF had very severe stroke (0â14 points) than patients without AF (13.7% versus 7.9%, P<0.01). The absolute rates of 30âday and 1âyear mortality were significantly higher for patients with AF (12.1% and 28.4%, respectively) versus patients without AF (8.7% and 21.8%, respectively). This held true in adjusted models for 30âday mortality (hazard ratio [HR], 1.40 [95% CI, 1.30â1.51]). However, this association became nonsignificant when additionally adjusting for stroke severity (HR, 1.10 [95% CI, 1.00â1.23]). AF was associated with a higher rate of 1âyear mortality (HR, 1.39 [95% CI, 1.32â1.46]), although it was mediated by stroke severity (HR, 1.15 [95% CI, 1.09â1.23], model including stroke severity). Conclusions In a contemporary nationwide cohort of patients with ischemic stroke, patients with AF had more severe strokes and higher mortality than patients without AF. The difference in mortality was mainly driven by stroke severity
Sacubitril/valsartan reduces serum uric acid concentration, an independent predictor of adverse outcomes in PARADIGM-HF
Aims:
Elevated serum uric acid concentration (SUA) has been associated with an increased risk of cardiovascular disease, but this may be due to unmeasured confounders. We examined the association between SUA and outcomes as well as the effect of sacubitril/valsartan on SUA in patients with heart failure with reduced ejection fraction (HFrEF) in PARADIGM-HF.
Methods and results:
The association between SUA and the primary composite outcome of cardiovascular death or heart failure (HF) hospitalization, its components, and all-cause mortality was examined using Cox regression analyses among 8213 patients using quintiles (Q1âQ5) of SUA adjusted for baseline prognostic variables including estimated glomerular filtration rate (eGFR), diuretic dose, and log N-terminal pro-brain natriuretic peptide. Change in SUA from baseline over 12âmonths was also evaluated in each treatment group. Patients in Q5 (SUA âĽ8.6âmg/dL) compared with Q1 (<5.4âmg/dL) were younger (62.8 vs. 64.2âyears), more often male (88.7% vs. 63.1%), had lower systolic blood pressure (119 vs. 123âmmHg), lower eGFR (57.4 vs. 76.6âmL/min/1.73âm2), and greater diuretic use. Higher SUA was associated with a higher risk of the primary outcome (adjusted hazard ratios) Q5 vs. Q1â=â1.28 [95% confidence intervals (1.09â1.50), Pâ=â0.003], cardiovascular death [1.44 (1.11â1.77), Pâ=â0.001], HF hospitalization [1.37 (1.11â1.70), Pâ=â0.004], and all-cause mortality [1.36 (1.13â1.64), Pâ=â0.001]. Compared with enalapril, sacubitril/valsartan reduced SUA by 0.24 (0.17â0.32) mg/dL over 12âmonths (Pâ<â0.0001). Sacubitril/valsartan improved outcomes, irrespective of SUA concentration.
Conclusion:
Serum uric acid concentration was an independent predictor of worse outcomes after multivariable adjustment in patients with HFrEF. Compared with enalapril, sacubitril/valsartan reduced SUA and improved outcomes irrespective of SUA
Risk related to preâdiabetes mellitus and diabetes mellitus in heart failure with reduced ejection fraction: insights from prospective comparison of ARNI with ACEI to determine impact on global mortality and morbidity in heart failure trial
BackgroundâThe prevalence of preâdiabetes mellitus and its consequences in patients with heart failure and reduced ejection fraction are not known. We investigated these in the Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial.
Methods and ResultsâWe examined clinical outcomes in 8399 patients with heart failure and reduced ejection fraction according to history of diabetes mellitus and glycemic status (baseline hemoglobin A1c [HbA1c]: <6.0% [<42 mmol/mol], 6.0%â6.4% [42â47 mmol/mol; preâdiabetes mellitus], and âĽ6.5% [âĽ48 mmol/mol; diabetes mellitus]), in Cox regression models adjusted for known predictors of poor outcome. Patients with a history of diabetes mellitus (n=2907 [35%]) had a higher risk of the primary composite outcome of heart failure hospitalization or cardiovascular mortality compared with those without a history of diabetes mellitus: adjusted hazard ratio, 1.38; 95% confidence interval, 1.25 to 1.52;P<0.001. HbA1c measurement showed that an additional 1106 (13% of total) patients had undiagnosed diabetes mellitus and 2103 (25%) had preâdiabetes mellitus. The hazard ratio for patients with undiagnosed diabetes mellitus (HbA1c, >6.5%) and known diabetes mellitus compared with those with HbA1c<6.0% was 1.39 (1.17â1.64); P<0.001 and 1.64 (1.43â1.87); P<0.001, respectively. Patients with preâdiabetes mellitus were also at higher risk (hazard ratio, 1.27 [1.10â1.47];P<0.001) compared with those with HbA1c<6.0%. The benefit of LCZ696 (sacubitril/valsartan) compared with enalapril was consistent across the range of HbA1c in the trial.
ConclusionsâIn patients with heart failure and reduced ejection fraction, dysglycemia is common and preâdiabetes mellitus is associated with a higher risk of adverse cardiovascular outcomes (compared with patients with no diabetes mellitus and HbA1c <6.0%). LCZ696 was beneficial compared with enalapril, irrespective of glycemic status
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