Low-frequency magnetic sensing by magnetoelectric metglas/bidomain LiNbO3 long bars

We present an investigation into the magnetic sensing performance of magnetoelectric bilayered metglas / bidomain LiNbO3 long thin bars operating in a cantilever or free vibrating regime and under quasi-static and low-frequency resonant conditions. Bidomain single crystals of Y+128o-cut LiNbO3 were engineered by an improved diffusion annealing technique with a polarization macrodomain structure of the “head-to-head” and “tail-to-tail” type. Long composite bars with lengths of 30, 40 and 45 mm, as well as with and without attached small tip proof masses, were studied. ME coefficients as large as 550 V/cm∙Oe, corresponding to a conversion ratio of 27.5 V/Oe, were obtained under resonance conditions at frequencies of the order of 100 Hz in magnetic bias fields as low as 2 Oe. Equivalent magnetic noise spectral densities down to 120 pT/Hz1/2 at 10 Hz and to 68 pT/Hz1/2 at a resonance frequency as low as 81 Hz were obtained for the 45 mm long cantilever bar with a tip proof mass of 1.2 g. In the same composite without any added mass the magnetic noise was shown to be as low as 37 pT/Hz1/2 at a resonance frequency of 244 Hz and 1.2 pT/Hz1/2 at 1335 Hz in a fixed cantilever and free vibrating regimes, respectively. A simple unidimensional dynamic model predicted the possibility to drop the low-frequency magnetic noise by more than one order of magnitude in case all the extrinsic noise sources are suppressed, especially those related to external vibrations, and the thickness ratio of the magnetic-to-piezoelectric phases is optimized. Thus, we have shown that such systems might find use in simple and sensitive room-temperature low-frequency magnetic sensors, e.g., for biomedical applications.publishe

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

Carbon nanostructures reduced from graphite oxide as electrode materials for supercapacitors

In this review we present information about obtaining and properties of carbon nanomaterials (graphite oxide, grapheme oxide, reduced graphene oxide), which are used as electrodes for supercapacitors (SC). This review describes methods of obtaining graphite oxide, followed by separation of graphene oxide and reducing graphene oxide by thermal, photochemical and chemical methods. Information on the composition and concentration of functional groups in graphene oxide and the elemental composition is described in detail. Results of the analysis of еру physical, electrochemical, thermal and optical properties of the graphene oxide and its derivatives are shown. The ratio of oxygen-containing functional groups was estimated by XPS. The presence of partial surface reduction is found. Hydroge-containing functional groups are characterized by IR spectroscopy. Method of estimating the size of graphene crystallites by Raman spectroscopy is shown. Mass loss upon heating is analyzed by thermogravimetry. The gassing of graphene oxide at thermal and photochemical reduction is studied by mass spectrometry. The difference between the abovementioned reduction methods is clearly demonstrated by the difference in the composition of the evolved gases. Also the chemical method of graphene oxide reduction with hydrazine is described. Review considers the literature data which illustrate the most interesting, from the Authors׳ point of view, aspects of that field of research

Magnetic structural effect (MSE) in epitaxial films of cerium oxide and lanthanum zirconate

Increasing the critical current density in the second generation high-temperature superconducting wires (2G HTS) is the major challenge for researchers and manufacturers of 2G HTS wires all over the world. We proposed a new approach to increase the number of percolation paths for supercurrent, i.e. increasing the number of low angle grain boundaries (<5°) in the epitaxial superconducting YBCO layer by magnetic structural processing (MSP) of buffer layers. New experimental results have been presented on the application of MSP for improving the structure and increasing the texture sharpness of buffer in electrical conducting element of 2G HTS wire. The influence of MCO on the structural and textural properties has been investigated in a buffer consisting of epitaxial films of cerium oxide CeO2 and lanthanum zirconate La2Zr2O7 in the CeO2/4La2Zr2O7 architecture. The influence of the magnetic processing of the epitaxial La2Zr2O7 buffer film on the shape of grains has been found. An atomic force microscopical study has shown that after magnetic processing the shape of grains improved significantly. A multilayer CeO2/4La2Zr2O7 buffer each layer of which was processed in a magnetic field has a high degree of orientation: only one diffraction peak with (200) indexes is observed in the X-ray spectrum. The X-ray settings of the (200) diffraction peak indicate a well developed epitaxial structure of CeO2 and La2Zr2O7 layers. The texture of the buffer is by more than 2° sharper than that of the Ni–5 at% W substrate

Mechanism of ethanol steam reforming over Pt/(Ni+Ru)-promoted oxides by FTIRS in situ

Mechanism of ethanol steam reforming into syngas over Pt/Pr0.15Sm0.15Ce0.35Zr0.35O2 and 10 wt% LaNi0.9Ru0.1O3/Mg-Al2O3 catalysts was studied by in situ FTIRS and pulse titration experiments. Surface species (ethoxy, adsorbed ethanol, acetaldehyde, acetate, etc.) were identified and their thermal stability, routers of transformation and reactivity were characterized. Acetate species were shown to be spectators for both types of catalysts. Transformation of ethoxy species by dehydrogenation is a fast step, while the rate-determining stage is the C–C bond rupture in thus formed acetaldehyde on metal sites. For Pt/Pr0.15Sm0.15Ce0.35Zr0.35O2 catalyst with a high mobility and reactivity of the surface/lattice oxygen of support, efficient oxidative transformation of acetaldehyde at the metal-support interface provides a high yield of syngas at short contact times in the intermediate temperature range with a minor amount of CH4 by-product. Transformation of ethoxy species on the acid sites of alumina-supported catalyst produces C2H4 and (C2H5)2O via dehydration route dominating at temperatures below 400 °C. In addition, for alumina-supported catalyst acetone is produced via aldol formation in the temperature range 400–500 °C due to combined action of metal and support sites. For this catalyst syngas yield is improved at high temperatures when steam reforming of these byproducts efficiently proceeds accompanied by cracking reactions producing also methane as by-product

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.)