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Bismuth Ion (bismuth + ion)
Selected AbstractsStrong Ultra-Broadband Near-Infrared Photoluminescence from Bismuth-Embedded Zeolites and Their DerivativesADVANCED MATERIALS, Issue 36 2009Hong-Tao Sun Zeolites with embedded bismuth compounds display strong, air-stable, long-lived, ultrabroadband, and tunable near-infrared photoluminescence (see picture). Bismuth ions not only act as luminescence-active centers, but also as blocks for selectively closing the "in,out windows" of water molecules. Bismuth active centers can be sealed in a low-vibrational environment by bismuth agglomerates even when the sample still contains a large amount of water. [source] Is Eradication of Helicobacter pylori With Colloidal Bismuth Subcitrate Quadruple Therapy Safe?HELICOBACTER, Issue 2 2001Rosemary H. Phillips ABSTRACT Background. When standard triple therapy fails to eradicate Helicobacter pylori, quadruple ,rescue' therapy is often used which, in Europe, generally comprises colloidal bismuth subcitrate (CBS) based triple therapy and a proton pump inhibitor. Since hypochlorhydria could greatly increase absorption of the toxic bismuth ion from CBS, we investigated the bismuth status of patients receiving anti- H. pylori quadruple therapy. Materials and Methods. In a prospective open label study 34 patients with nonulcer dyspepsia or peptic ulcer disease, who had failed to eradicate H. pylori with standard triple therapy, were subsequently treated with CBS, omeprazole, amoxycillin and metronidazole (BOAM). A further 35 patients received triple therapy for the eradication of H. pylori: CBS, amoxycillin and metronidazole (BAM) (n = 18); placebo bismuth, amoxycillin and metronidazole (AM) (n = 9); or omeprazole, amoxycillin and metronidazole (OAM) (n = 8). Whole blood bismuth levels were determined before and within 24 hours of completing treatment. Analysis of bismuth was by inductively coupled plasma mass spectrometry, and concentrations were compared between groups and with the Hillemand ,alarm level' for blood bismuth (50,100 µg/l). Results. BOAM gave higher blood bismuth levels than BAM (difference in means 13.1, CI 6.0,20.2, p < .001); three (8.8%) patients taking BOAM had concentrations within the Hillemand alarm level at 54.2, 64.7 and 91.8 µg/l. OAM and AM did not alter baseline blood bismuth levels. Conclusions. Caution should be observed in prescribing CBS with gastric acid suppression, and alternative bismuth preparations should be considered. [source] A new bismuth iron oxyphosphate, Bi6(Bi0.32Fe0.68)(PO4)4O4ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2008Nachiappan Arumugam Iron was inserted into the known crystal structure of the bismuth phosphate oxide Bi6.67(PO4)4O4 to ascertain its location in the vacancies associated with the bismuth ion located at the origin of the unit cell. Single-crystal X-ray diffraction refinements converged to a model of composition Bi6(Bi0.32Fe0.68)(PO4)4O4 (hexabismuth iron tetraphosphate tetraoxide), in which Bi and Fe are displaced from the origin giving rise to a random distribution over the 2i sites instead of 1a, the origin of space group P. The isotropic displacement parameter for Bi/Fe has a reasonable value in this model. This structure establishes for the first time that Fe substitutes in the Bi-deficient site in this series of materials and that Fe and Bi are disordered around the center of symmetry. These results enhance understanding of the crystal chemistry of these main group phosphates that are of interest in ion transport. [source] Preparation and Characterization of Bi3+ -TiO2 and its Photocatalytic ActivityCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 5 2007H. Zuo Abstract Bi3+ -TiO2 photocatalysts were prepared by doping bismuth ion into the TiO2 structure in a sol-gel process. The catalyst samples were then characterized by UV-vis diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Rodamine-B (RhB) was used in this study as a model chemical with the aim of organic pollutants control. The photocatalytic degradation of RhB demonstrated that an optimal loading of bismuth 0.7,at.,% achieved the highest photodegradation rate, with the rate constant increasing by a factor of 3.89 over neat TiO2 (P25) under UV illumination (, , 320,nm). The degradation of p -nitrobenzonic acid (pNBA) was also examined to prevent/preclude/exclude/ the photosensitization pathway. GC-MS results show that pNBA can be effectively degraded and minerized to small molecules, such as quinone, acetic acid and formic acid. [source] | ||||||||||