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A simple approach was used to create Fe3O4-methylcellulose (MC) nanocomposites, which were then analyzed using XRD, FTIR, and FE-SEM to determine their structure. The effective factors for enhancing the ratio of magnetite NPs in the samples were investigated using RTFM and optical absorbance. Fe3O4 was synthesized utilizing the reverse co-precipitation technique and magnetic characteristics. Fe3O4/MC nanocomposites with magnetite/MC weight ratios of 0, 0.07, 0.15, and 0.25 have been developed. The diffraction pattern of magnetite is well indexed in accordance with the spinal reference pattern of Fe3O4 (space group: R¯3m), as confirmed by the Rietveld analysis of XRD data of magnetite NPs with an average crystallite size of 50 nm. Magnetite's insertion into the MC network causes a red shift in the band gap energy (Eg) as the weight percentage of magnetite nanoparticles in the samples rises. The MC, MC-7, MC-15, and MC-25 samples have Eg values of 5.51, 5.05, 2.84, and 2.20 eV, respectively. [ABSTRACT FROM AUTHOR]

Water pollution has emerged as a major challenge for the scientific community because of the rapid expansion of the population and the industrial sector in the world. The current study focuses on introducing a new track for designing new optical nanocomposites for purifying water in addition to providing a new additive for building new nanohybrids. These targets were achieved through building a ternary system of Co/Ti/Zn nanocomposites and nanolayered structures. The Co/Ti/Zn nanolayered structures were prepared and intercalated by different kinds of organic acids: monocarboxylic and dicarboxylic acids. Long chains of organic acids were used to construct series of organic–inorganic nanohybrids. X-ray diffraction, thermal analyses, Fourier Transform Infrared spectroscopy, and scanning electron microscopy confirmed the formation of nanolayered structures and nanohybrids. The optical properties of the nanolayered structure showed that the Co/Ti/Zn LDH became photo-active compared with the usual Al/Zn LDH because of the reduction in the band gap energy from 5.3 eV to 3.3 eV. After thermal treatment, a highly photo-active nanocomposite was produced through observing more reduction for the band gap energy to become 2.8 eV. In addition, the dye of Acid Green 1 completely decomposed and converted to water and carbon dioxide during 17 min of UV radiation by the dual Co/Ti-doped zinc oxide nanocomposite. In addition, the kinetic study confirmed that the high optical activity of the dual Co/Ti-doped zinc oxide nanocomposite accelerated the degradation of the green dyes. Finally, from these results it could be concluded that designing effective nanocomposite for purification of water was accomplished through converting 2D nanolayered structures to a 3D porous structure of Ni/Ti/Zn nanocomposites. In addition, a new additive was achieved for heterostructured hybrids through building new Co/Ti/Zn/organic nanohybrids. [ABSTRACT FROM AUTHOR]

Herein we have fabricated AuTiO2 from a one-dimensional (1D) nanocomposite by the simple oxidation method of the Ti sheet for supercapacitor applications. We intended on fabricating a microlayer extended into the sheet body to form a selfstanding electrode. Raman spectra and XRD patterns confirmed the formation of the rutile phase of the TiO2 bulk, and FESEM confirmed the growth of the 1D nanostructure made of Au/TiO2, where the Au nanoparticles reside on the tip of the TiO2 nanorods. The growth of 1D TiO2 by this method is supported by a growth mechanism during the oxidation process. Three electrodes were fabricated based on pure and doped TiO2. These electrodes were used as a selfstanding supercapacitor electrode. The Au-doped TiO2 exhibited a great improvement in the electrochemical performance at low Au concentrations, whereas the excessive Au concentration on the TiO2 surface exhibited a negative effect on the capacitance value. The highest areal capacitance of 72 mFcm−2 at a current density of 5 µAcm−2 was recorded for TiO2 doped with a low Au concentration. The mechanism of the electrochemical reaction was proposed based on Nyquist and Bode plots. The obtained results point out that the effect of Au on the TiO2 surface makes Au/TiO2 ceramic electrodes a promising material as selfstanding energy storage electrodes. [ABSTRACT FROM AUTHOR]

Background: Mitral valve annuloplasty is a fundamental component in mitral valve repair to restore the size and shape of the native annulus and to prevent future annular dilatation. Aim of work: To assess the early results of MV repair using flexible bands in patients with non ischemic mitral regurgitation. Patients and Methods: We prospectively reviewed 53 patients who underwent mitral valve repair with a flexible. We evaluate all patients 1 year postoperatively to assess the progress of the repair procedure. Results: Mean age at the time of operation was 38.8±11 years and more than half of them were females (56.6%). Preoperative mean ejection fraction was 61.7 ± 8.9%, and the majority (84.9%) of patients had severe mitral regurge on preoperative echocardiography. Regarding the 30-day mortality was 1.9%. At last follow up, 47.2% of patients had no or mild regurgitation and the mean ejection fraction was 57.9 ± 8.2%. Conclusion: The early outcomes of mitral valve repair with flexible band show good results in our prospective observational study. Mitral valve annuloplasty with flexible band gives satisfactory results as regards NYHA classification, left ventricular function and dimensions. [ABSTRACT FROM AUTHOR]

Previous publications showed that graphene sheets polymer nanocomopsites were prepared by incorporating previously prepared graphene into the polymer matrix through two or more successive steps. In this work, graphene sheets were exfoliated from graphite inside the polymer matrix solution for certain period in one step. This approach was easy to perform, low cost, high mass production of graphene and, almost, produces effective results. In this respect, electrolytic solution from poly(vinyl alcohol) (PVA) and salt was prepared and exfoliation process took place inside it for different times. After that, solution was dried to get films of PVA loaded with different concentrations of graphene sheets. Scanning electron microscopic and transmission electron microscopic images of exfoliated graphene sheets were studied. Raman spectroscopy of graphite, graphene nanosheets, and PVA-loaded graphene was studied. The dielectric permittivity, dielectric loss, and alternating current electrical conductivity were studied and had maximum values at 10 min of exfoliation time. Cole–Cole impedance plots show semicircles behavior with lowest radius for samples prepared at 10 min. The elastic modulus was found to have a maximum value at exfoliation time of 30 min. [ABSTRACT FROM AUTHOR]