4 research outputs found
Vertically Aligned Carbon Nanotubes Production by PECVD
This chapter presents the results of experimental studies of the PECVD technological mode parameters’ influence on the formation of catalytic centers and carbon nanotubes’ (CNTs’) growth processes. This chapter also presents the ability to regulate the growth parameter for the controlled production of CNTs with the required geometric parameters, properties, and growth mechanisms. The results of experimental studies of the heating temperature and activation time effects on the catalytic center formation will be presented. This chapter also shows the effects of growth temperature, heating rate, and the activation time on the geometric and structural parameters of the carbon nanotubes. Experimental studies were carried out with the use of AFM, SEM, TEM, and EXAFS techniques. The results can be used in the development of technological processes for creating ultrafast energy-efficient electronic component base with carbon nanostructures, particularly nanoelectromechanical switches, flexo- and piezoelectric generators, gas sensors, and high-performance emitters
Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia
BACKGROUND
Patients with elevated triglyceride levels are at increased risk for ischemic events. Icosapent
ethyl, a highly purified eicosapentaenoic acid ethyl ester, lowers triglyceride levels, but data
are needed to determine its effects on ischemic events.
METHODS
We performed a multicenter, randomized, double-blind, placebo-controlled trial involving
patients with established cardiovascular disease or with diabetes and other risk factors, who
had been receiving statin therapy and who had a fasting triglyceride level of 135 to 499 mg
per deciliter (1.52 to 5.63 mmol per liter) and a low-density lipoprotein cholesterol level of
41 to 100 mg per deciliter (1.06 to 2.59 mmol per liter). The patients were randomly assigned
to receive 2 g of icosapent ethyl twice daily (total daily dose, 4 g) or placebo. The primary
end point was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal
stroke, coronary revascularization, or unstable angina. The key secondary end point was a
composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke.
RESULTS
A total of 8179 patients were enrolled (70.7% for secondary prevention of cardiovascular
events) and were followed for a median of 4.9 years. A primary end-point event occurred in
17.2% of the patients in the icosapent ethyl group, as compared with 22.0% of the patients
in the placebo group (hazard ratio, 0.75; 95% confidence interval [CI], 0.68 to 0.83; P<0.001);
the corresponding rates of the key secondary end point were 11.2% and 14.8% (hazard ratio,
0.74; 95% CI, 0.65 to 0.83; P<0.001). The rates of additional ischemic end points, as assessed
according to a prespecified hierarchical schema, were significantly lower in the icosapent
ethyl group than in the placebo group, including the rate of cardiovascular death (4.3% vs.
5.2%; hazard ratio, 0.80; 95% CI, 0.66 to 0.98; P=0.03). A larger percentage of patients in
the icosapent ethyl group than in the placebo group were hospitalized for atrial fibrillation
or flutter (3.1% vs. 2.1%, P=0.004). Serious bleeding events occurred in 2.7% of the patients
in the icosapent ethyl group and in 2.1% in the placebo group (P=0.06).
CONCLUSIONS
Among patients with elevated triglyceride levels despite the use of statins, the risk of ischemic events, including cardiovascular death, was significantly lower among those who received 2 g of icosapent ethyl twice daily than among those who received placebo. (Funded
by Amarin Pharma; REDUCE-IT ClinicalTrials.gov number, NCT01492361
Analysis of the Piezoelectric Properties of Aligned Multi-Walled Carbon Nanotubes
Recent studies reveal that carbon nanostructures show anomalous piezoelectric properties when the central symmetry of their structure is violated. Particular focus is given to carbon nanotubes (CNTs) with initial significant curvature of the graphene sheet surface, which leads to an asymmetric redistribution of the electron density. This paper presents the results of studies on the piezoelectric properties of aligned multi-walled CNTs. An original technique for evaluating the effective piezoelectric coefficient of CNTs is presented. For the first time, in this study, we investigate the influence of the growth temperature and thickness of the catalytic Ni layer on the value of the piezoelectric coefficient of CNTs. We establish the relationship between the effective piezoelectric coefficient of CNTs and their defectiveness and diameter, which determines the curvature of the graphene sheet surface. The calculated values of the effective piezoelectric coefficient of CNTs are shown to be between 0.019 and 0.413 C/m2, depending on the degree of their defectiveness and diameter
Cardiac myosin activation with omecamtiv mecarbil in systolic heart failure
BACKGROUND The selective cardiac myosin activator omecamtiv mecarbil has been shown to improve cardiac function in patients with heart failure with a reduced ejection fraction. Its effect on cardiovascular outcomes is unknown. METHODS We randomly assigned 8256 patients (inpatients and outpatients) with symptomatic chronic heart failure and an ejection fraction of 35% or less to receive omecamtiv mecarbil (using pharmacokinetic-guided doses of 25 mg, 37.5 mg, or 50 mg twice daily) or placebo, in addition to standard heart-failure therapy. The primary outcome was a composite of a first heart-failure event (hospitalization or urgent visit for heart failure) or death from cardiovascular causes. RESULTS During a median of 21.8 months, a primary-outcome event occurred in 1523 of 4120 patients (37.0%) in the omecamtiv mecarbil group and in 1607 of 4112 patients (39.1%) in the placebo group (hazard ratio, 0.92; 95% confidence interval [CI], 0.86 to 0.99; P = 0.03). A total of 808 patients (19.6%) and 798 patients (19.4%), respectively, died from cardiovascular causes (hazard ratio, 1.01; 95% CI, 0.92 to 1.11). There was no significant difference between groups in the change from baseline on the Kansas City Cardiomyopathy Questionnaire total symptom score. At week 24, the change from baseline for the median N-terminal pro-B-type natriuretic peptide level was 10% lower in the omecamtiv mecarbil group than in the placebo group; the median cardiac troponin I level was 4 ng per liter higher. The frequency of cardiac ischemic and ventricular arrhythmia events was similar in the two groups. CONCLUSIONS Among patients with heart failure and a reduced ejection, those who received omecamtiv mecarbil had a lower incidence of a composite of a heart-failure event or death from cardiovascular causes than those who received placebo. (Funded by Amgen and others; GALACTIC-HF ClinicalTrials.gov number, NCT02929329; EudraCT number, 2016 -002299-28.)