PREPARATION, IDENTIFICATION AND BIOLOGICAL PROPERTIES OF NEW FLUORIDE NANOCOMPOUNDS

Indexación: Web of Science; Scopus.Nanoparticles (NPs) of new fluoride (SrF2 and MgF2) nanocompounds were synthesized by the simple chemical method of precipitation in ethanol. Synthesis of the strontium fluoride (SrF2)-magnesium oxide (MgO) nanocomposite was achieved through the ultrasonic method. These prepared nanopowders were characterized through Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Powder X-ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM). FT-IR confirmed the purity of the synthesized fluoride NPs by evaluation of the vibrations, and UV-Visible showed the intense absorption peaks of NPs. PXRD analysis indicated the average of particle size, and SEM demonstrated a nearly spherical morphology of the NPs. The antibacterical properties of the nanopowders on Staphylococcus Aureus, Bacillus Subtilis and E. Aklay bacteria were studied, with the strongest effect by the magnesium fluoride (MgF2) NPs and the SrF2-MgO nanocomposite.http://ref.scielo.org/yfr3f

Study of low band gap DSSCs based on bridging bithiophene and biphenyl: Theoretical investigation

International audienceIn this paper, theoretical study using density functional theory (DFT) method (B3LYP level with 6-31G(d,p)) of four novel low band gap acceptor-donor organic materials based on thiophene and phenyl and linked to cyanoacrylic acid as acceptor group are investigated. Different electron side groups were introduced to investigate their effects on the electronic structure; the HOMO, LUMO, gap energy, ionization potentials, electron affinities and open circuit voltage (V oc) of these compounds have been calculated and reported in this paper. The electronic absorption and emission spectra of these dyes are studied by time-dependent density functional theory calculations. A systematic theoretical study of such compound has not been reported as we know. Thus, our aim is first, to explore their electronic and spectroscopic properties on the basis of the DFT quantum chemical calculations. We think that the presented study of structural, electronic and optical properties for these compounds could help in designing more efficient functional photovoltaic organic materials. © 2015 Iranian Chemical Society

Efficacy and safety of low-dose aspirin in polycythemia vera

BACKGROUND: The use of aspirin for the prevention of thrombotic complications in polycythemia vera is controversial. METHODS: We enrolled 518 patients with polycythemia vera, no clear indication for aspirin treatment, and no contraindication to such treatment in a double-blind, placebo-controlled, randomized trial to assess the safety and efficacy of prophylaxis with low-dose aspirin (100 mg daily). The two primary end points were the cumulative rate of nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes and the cumulative rate of nonfatal myocardial infarction, nonfatal stroke, pulmonary embolism, major venous thrombosis, or death from cardiovascular causes. The mean duration of follow-up was about three years. RESULTS: Treatment with aspirin, as compared with placebo, reduced the risk of the combined end point of nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes (relative risk, 0.41; 95 percent confidence interval, 0.15 to 1.15; P=0.09) and the risk of the combined end point of nonfatal myocardial infarction, nonfatal stroke, pulmonary embolism, major venous thrombosis, or death from cardiovascular causes (relative risk, 0.40; 95 percent confidence interval, 0.18 to 0.91; P=0.03). Overall mortality and cardiovascular mortality were not reduced significantly. The incidence of major bleeding episodes was not significantly increased in the aspirin group (relative risk, 1.62; 95 percent confidence interval, 0.27 to 9.71). CONCLUSIONS: Low-dose aspirin can safely prevent thrombotic complications in patients with polycythemia vera who have no contraindications to such treatment