Background-␤-Blockers have improved symptoms and reduced the risk of cardiovascular events in studies of patients with heart failure, but it is unclear which end points are most sensitive to the therapeutic effects of these drugs. Methods and Results-We combined the results of all 18 published double-blind, placebo-controlled, parallel-group trials of ␤-blockers in heart failure. From this combined database of 3023 patients, we evaluated the strength of evidence supporting an effect of treatment on left ventricular ejection fraction, NYHA functional class, hospitalizations for heart failure, and death. ␤-Blockers exerted their most persuasive effects on ejection fraction and on the combined risk of death and hospitalization for heart failure. ␤-Blockade increased the ejection fraction by 29% (PϽ10

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The purpose of this article is to study the dielectric dispersion of two different ternary composites made of epoxy resin (RE), black iron oxide (Fe3O4) with one of the two titanates (calcium titanate (CaTiO3) or strontium (SrTiO3)) on several frequency bands. Additionally, the effect of the two titanates and the (Fe3O4) on the permittivity and conductivity of these ternary composites is investigated. These composite materials were characterized using time domain spectroscopy (TDS). The inclusion of the two titanates increased the real permittivity and conductivity of the two composites, shifting the resonance frequency (ƒR) towards the low frequency range and causing the opposite phenomenon for the static permittivity (ε s). The frequency dispersion behavior model for the complex permittivity has been proposed to improve the effectiveness of the predictive frequency model through a better choice of the damping factor and to bring theoretical and experimental findings closer together. Comparing these data shows that the proposed model is applicable to ternary combinations with high accuracy. The values of the quality factor (Q) obtained are encouraging in microwave applications. These composite materials witch containing CaTiO3 and SrTiO3 inclusions have contributed to the development of dielectric permittivity that suits very well frequency communication systems.

The RE-ST-FE and RE-BT-FE/FR composites have been prepared and characterized using time domain spectroscopy method in the [DC-12.5] GHz range. The dielectric, magnetic, and electrical properties of the ternary composites have been investigated. In the RE-ST-FE composite, the dielectric permittivity (ε’) has been found to decrease from 9.25 to 3.70 with increase in FE concentration. While it has been observed that the electrical conductivity increases as the ST concentration increases reaching a value of 11.6 (mS / m) and shows a percolation behavior with (Vth = 26,9% ST). In the RE-BT-FE/FR composites, the magnetization hysteresis loops have been measured by vibrating sample magnetometer from -3 to +3 kOe. This has made it possible to have a maximum of saturation magnetization equal 29.3 emu/g and the permeability value close to 1.9 with the RE-BT-FR composite which is considered higher than that of the other one. It was found that an increase in the (FE/FR) concentration increases the magnetic permeability, which is confirmed by the modified Lichtenecker law with error ratio less than 0.5%. The results of this study will undoubtedly yield new materials that can be used to miniaturize electronic components used in telecommunications systems, resonators, antennas and wave absorbers.