Preparation and characterization of bismuth oxichloride (BiOCl) nanoparticles and nano zerovalent iron (nZVI)

NASA Astrophysics Data System (ADS)

Sarwan, Bhawna; Pare, Brijesh; Deep Acharya, Aman

2017-05-01

In this work, we have synthesized nano scale zerovalent iron (nZVI) particles by borohydride reduction method and bismuth oxichloride (BiOCl) by a hydrolysis method. X-ray powder diffraction (XRD) was used for the structural and chemical characterization, while scanning/transmission electron microscopy (SEM/TEM) were employed to determine the physical properties of the nanoparticles. The reactivity of synthesized nanoparticles was compared by decolorization of nile blue (NB) dye under visible irradiation.

Effect of bismuth doping on the structural and magnetic properties of zinc-ferrite nanoparticles prepared by a microwave combustion method

NASA Astrophysics Data System (ADS)

Shoushtari, Morteza Zargar; Emami, Akram; Ghahfarokhi, Seyed Ebrahim Mosavi

2016-12-01

In this study, we examine the bismuth doping effect on the structural, magnetic and microstructural properties of zinc-ferrite nanoparticles (ZnFe2-xBixO4 with x=0.0, 0.02, 0.04, 0.06, 0.1, 0.15) which have been prepared by a microwave combustion method. The structural, morphological and electromagnetic properties and also Curie temperature of the samples were examined by x-ray powder diffraction (XRD), field emission scanning electron microscope (FESEM), vibrating sample magnetometer (VSM), and LCR meter, respectively. In order to measure the energy band gap, the FTIR spectra of the samples were also considered. The XRD patterns of the samples revealed that all of them are ZnFe2O4 structure and no additional peak was observed in their patterns. This implied that the samples were single-phase up to bismuth solubility of 0.15 in Zinc-Ferrite. The results of XRD patterns also showed that the value lattice parameter increases with increasing the bismuth doping. The FESEM results revealed an ascending trend in the size of the nanoparticles. Also considering the VSM results characterized that an increasing the bismuth doping leads to lower the saturation magnetization. The Curie temperatures of the samples were reduced as a result of increasing the amount of bismuth.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chu, C.C.

A process is described of dehydrogenating para-ethyltoluene to selectively form para-methylstyrene comprising contacting to para-ethyltoluene under dehydrogenation reaction conditions with a catalyst composition comprising: (a) from about 30% to 60% by weight of iron oxide, calculated as ferric oxide; (b) from about 13% to 48% by weight of a potassium compound, calculated as potassium oxide; and (c) from about 0% to 5% by weight of a chromium compound, calculated as chromic oxide. The improvement is described comprising dehydrogenating the para-ethyltoluene with a catalyst composition comprising, in addition to the components (a), (b) and (c), a modifying component (d) capable ofmore » rendering the para-methylstyrene-containing dehydrogenation reaction effluent especially resistant to the subsequent formation of popcorn polymers when the dehydrogenation of para-ethyltoluene is conducted over the modified catalyst, the modifying component (d) being a bismuth compound present to the extent of from about 1% to 20% by weight of the catalyst composition, calculated as bismuth trioxide.« less

Modeling of oxidation of aluminum nanoparticles by using Cabrera Mott Model

NASA Astrophysics Data System (ADS)

Ramazanova, Zamart; Zyskin, Maxim; Martirosyan, Karen

2012-10-01

Our research focuses on modeling new Nanoenergetic Gas-Generator (NGG) formulations that rapidly release a large amount of gaseous products and generates shock and pressure waves. Nanoenergetic thermite reagents include mixtures of Al and metal oxides such as bismuth trioxide and iodine pentoxide. The research problem is considered a spherically symmetric case and used the Cabrera Mott oxidation model to describe the kinetics of oxide growth on spherical Al nanoparticles for evaluating reaction time which a process of the reaction with oxidizer happens on the outer part of oxide layer of aluminum ions are getting in contact with an oxidizing agent and react. We assumed that a ball of Al of radius 20 to 50 nm is covered by a thin oxide layer 2-4 nm and is surrounded by abundant amount of oxygen stored by oxidizers. The ball is rapidly heated up to ignition temperature to initiate self-sustaining oxidation reaction. As a result highly exothermic reaction is generated. In the oxide layer of excess concentrations of electrons and ions are dependent on the electric field potential with the corresponding of the Gibbs factors and that it conducts to the solution of a nonlinear Poisson equation for the electric field potential in a moving boundary domain. Motion of the boundary is determined by the gradient of a solution on the boundary. We investigated oxidation model numerically, using the COMSOL software utilizing finite element analysis. The computing results demonstrate that oxidation rate increases with the decreasing particle radius.

Synthesis and properties of silver nanoparticles in sodium bismuth borate glasses

NASA Astrophysics Data System (ADS)

Patwari, D. Rajeshree; Eraiah, B.

2018-04-01

Rare earth doped Sodium Bismuth Borate glass samples with silver chloride were prepared by melt quenching method. X-Ray diffraction pattern was used to confirm the amorphous nature of the samples. UV-Visible Spectra was recorded to study the optical properties. Surface plasmon resonance (SPR) peak was observed due to the formation of silver nanoparticles before and after heat treatment and the presence of silver nanoparticles were confirmed by UV-Visible Spectral studies and transmission electron microscopy. The surface plasmon resonance band became wider and red shifted after longer heat treatment.

Investigation on the photophysical properties of tungsten trioxide and tungstate based nanocomposites

NASA Astrophysics Data System (ADS)

Palanisamy, G.; Pazhanivel, T.

2018-04-01

Tungsten trioxide (WO3), Metal tungstates (SrWO4, Cr2WO6), WO3/SrWO4 and WO3/Cr2WO6 nanocomposites were successfully prepared by microwave irradiation method at relatively low temperature (500 °C). The synthesized samples were subjected to different investigation techniques, to know the materials physical and chemical properties. The structural and phase change formation of nanoparticles were investigated through XRD analysis. It shows that, the nanoparticles have highly crystalline nature. The shape and composition of the prepared nanoparticles were investigated through SEM and EDAX analysis. The optical properties of the synthesized samples were verified by Ultraviolet-diffuse reflectance spectroscopy and photoluminescence spectrometer. The emission intensity maximum of WO3 nanoparticle was red shifted when compared to composites. It may be due to the effect of delocalized electrons in the parent material. Simultaneously, the emission intensity was decreased because of trap states occurred on the surface of the composite nanoparticles. The photoluminescence spectra of the synthesized samples exhibit different emission (violet and blue) behavior. Hence, it may be useful for light emitting diode (LED) applications.

Analysis of the color alteration and radiopacity promoted by bismuth oxide in calcium silicate cement.

PubMed

Marciano, Marina Angélica; Estrela, Carlos; Mondelli, Rafael Francisco Lia; Ordinola-Zapata, Ronald; Duarte, Marco Antonio Hungaro

2013-01-01

The aim of the study was to determine if the increase in radiopacity provided by bismuth oxide is related to the color alteration of calcium silicate-based cement. Calcium silicate cement (CSC) was mixed with 0%, 15%, 20%, 30% and 50% of bismuth oxide (BO), determined by weight. Mineral trioxide aggregate (MTA) was the control group. The radiopacity test was performed according to ISO 6876/2001. The color was evaluated using the CIE system. The assessments were performed after 24 hours, 7 and 30 days of setting time, using a spectrophotometer to obtain the ΔE, Δa, Δb and ΔL values. The statistical analyses were performed using the Kruskal-Wallis/Dunn and ANOVA/Tukey tests (p<0.05). The cements in which bismuth oxide was added showed radiopacity corresponding to the ISO recommendations (>3 mm equivalent of Al). The MTA group was statistically similar to the CSC/30% BO group (p>0.05). In regard to color, the increase of bismuth oxide resulted in a decrease in the ΔE value of the calcium silicate cement. The CSC group presented statistically higher ΔE values than the CSC/50% BO group (p<0.05). The comparison between 24 hours and 7 days showed higher ΔE for the MTA group, with statistical differences for the CSC/15% BO and CSC/50% BO groups (p<0.05). After 30 days, CSC showed statistically higher ΔE values than CSC/30% BO and CSC/50% BO (p<0.05). In conclusion, the increase in radiopacity provided by bismuth oxide has no relation to the color alteration of calcium silicate-based cements.

Laser-generated bismuth nanoparticles for applications in imaging and radiotherapy

NASA Astrophysics Data System (ADS)

Torrisi, L.; Silipigni, L.; Restuccia, N.; Cuzzocrea, S.; Cutroneo, M.; Barreca, F.; Fazio, B.; Di Marco, G.; Guglielmino, S.

2018-08-01

Bismuth nanoparticles were obtained by laser ablation in water and characterized by using different physical techniques. Their shape, estimated by SEM measurements, was approximately spherical with an average diameter of about 25 nm, and a solution concentration of about 0.8 mg/ml was prepared. The formation of pure Bi nanoparticles was also confirmed by micro-Raman spectra which showed the characteristic first order Raman modes of rhombohedral bismuth. The presence of this phase was also supported by the XRD pattern. The EDX analysis indicated that the as-prepared nanoparticles contained Bi metallic element. The high Z of the nanoparticles in the solution shows effects of surface plasmon resonance in the near ultraviolet and visible regions, high mass absorption coefficient for X-ray interaction and high electronic and nuclear stopping powers for electron and ion beams. Such biocompatible solution can be injected in living systems, such as mice, in order to study the presence of uptake in different organs with high contrast spatial localization in the tissues where Bi nanoparticles are confined. The results indicate that Bi nanoparticles can be employed as high contrast medium for high resolution imaging in biological systems as well as target for exposition to ionizing radiation during radiotherapy or to visible light during hyperthermia of diseased cells.

In situ investigation of bismuth nanoparticles formation by transmission electron microscope.

PubMed

Liu, Liming; Wang, Honghang; Yi, Zichuan; Deng, Quanrong; Lin, Zhidong; Zhang, Xiaowen

2018-02-01

Bismuth (Bi) nanoparticles are prepared by using NaBi(MoO 4 ) 2 nanosheets in the beam of electrons emitted by transmission electron microscope. The formation and growth of Bi nanoparticles are investigated in situ. The sizes of Bi nanoparticles are confined within the range of 6-10nm by controlling irradiation time. It is also observed that once the diameter of nanoparticles is larger than 10nm, the Bi particles are stable as a result of the immobility of large nanoparticles. In addition, some nanoparticles on the edges form nanorods, which are explained as the result of a coalescence process, if the irradiation period is longer than 10min. The in situ research on Bi nanoparticles facilitates in-depth investigations of the physicochemical behavior and provides more potential applications in various fields such as sensors, catalysts and optical devices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dental discoloration caused by bismuth oxide in MTA in the presence of sodium hypochlorite.

PubMed

Marciano, Marina Angélica; Duarte, Marco Antonio Hungaro; Camilleri, Josette

2015-12-01

The aim of this research was to analyse the dental discolouration caused by mineral trioxide aggregate (MTA) induced by bismuth oxide and also assess the colour stability of other dental cements. Bismuth oxide, calcium tungstate and zirconium oxide were placed in contact with sodium hypochlorite for 24 h after which they were dried and photographed. Phase analyses were performed by X-ray diffraction (XRD) of radiopacifiers before and after immersion in sodium hypochlorite. Furthermore, teeth previously immersed in water or sodium hypochlorite were filled with MTA Angelus, Portland cement (PC), PC with 20 % zirconium oxide, PC with 20 % calcium tungstate and Biodentine. Teeth were immersed for 28 days in Hank's balanced salt solution after which they were sectioned and characterized using scanning electron microscopy (SEM) with energy-dispersive mapping and stereomicroscopy. Bismuth oxide in contact with sodium hypochlorite exhibited a change in colour from light yellow to dark brown. XRD analysis demonstrated peaks for radiopacifier and sodium chloride in samples immersed in sodium hypochlorite. The SEM images of the dentine to material interface showed alteration in material microstructure for MTA Angelus and Biodentine with depletion in calcium content in the material. The energy-dispersive maps showed migration of radiopacifier and silicon in dentine. MTA Angelus in contact with a tooth previously immersed in sodium hypochlorite resulted in colour alteration at the cement/dentine interface. MTA Angelus should not be used after irrigation with sodium hypochlorite as this will result in tooth discoloration.

The synthesis of Ba2+ doped multiferroic BiFeO3 nanoparticles by using a hydrothermal approach in the presence of different surface activators and the investigation of structural and magnetic features

NASA Astrophysics Data System (ADS)

Mardani, Reza

2017-05-01

In this work, Bi1-x Ba x FeO3 nanoparticles were synthesized by a hydrothermal method in the presence of various surface activators, and different amounts of barium were inserted in a bismuth ferrite (x  =  0.1, 0.15, 0.2) structure instead of bismuth. The structural and magnetic properties, morphology, and size of the synthesized nanoparticles were investigated by XRD, FT-IR, FE-SEM, TEM, DLS and VSM. The XRD analysis results reveal that the synthetic nanoparticles have a single phase. A phase shift from a rhombohedral structure to a tetragonal structure occurs due to the enhanced barium amount in the bismuth ferrite structure. The SEM analysis exhibits a uniform shape of the Bi0.85Ba0.15FeO3 particles and the image observed by TEM clarifies the size of the particles as 11 nm. Furthermore, the effect of the diverse surfaces of activators in the synthesis of Bi0.85Ba0.15FeO3 nanoparticles was studied, revealing that when sugar was used as a surfactant, the particle size reduced and the magnetic properties increased notably.

Bismuth nanoparticle decorating graphite felt as a high-performance electrode for an all-vanadium redox flow battery.

PubMed

Li, Bin; Gu, Meng; Nie, Zimin; Shao, Yuyan; Luo, Qingtao; Wei, Xiaoliang; Li, Xiaolin; Xiao, Jie; Wang, Chongmin; Sprenkle, Vincent; Wang, Wei

2013-03-13

Employing electrolytes containing Bi(3+), bismuth nanoparticles are synchronously electrodeposited onto the surface of a graphite felt electrode during operation of an all-vanadium redox flow battery (VRFB). The influence of the Bi nanoparticles on the electrochemical performance of the VRFB is thoroughly investigated. It is confirmed that Bi is only present at the negative electrode and facilitates the redox reaction between V(II) and V(III). However, the Bi nanoparticles significantly improve the electrochemical performance of VRFB cells by enhancing the kinetics of the sluggish V(II)/V(III) redox reaction, especially under high power operation. The energy efficiency is increased by 11% at high current density (150 mA·cm(-2)) owing to faster charge transfer as compared with one without Bi. The results suggest that using Bi nanoparticles in place of noble metals offers great promise as high-performance electrodes for VRFB application.

Facile synthesis of light harvesting semiconductor bismuth oxychloride nano photo-catalysts for efficient removal of hazardous organic pollutants.

PubMed

Seddigi, Zaki S; Gondal, Mohammed A; Baig, Umair; Ahmed, Saleh A; Abdulaziz, M A; Danish, Ekram Y; Khaled, Mazen M; Lais, Abul

2017-01-01

In the present work, bismuth oxychloride nanoparticles-a light harvesting semiconductor photocatalyst-were synthesized by a facile hydrolysis route, with sodium bismuthate and hydroxylammonium chloride as the precursor materials. The as-synthesized semiconductor photocatalysts were characterized using X-ray diffraction analysis, Fourier transform infra-red spectroscopy, Raman spectroscopy, Field emission scanning electron microscopy, X-ray photoelectron spectroscopy and Photoluminescence spectroscopy techniques. The crystal structure, morphology, composition, and optical properties of these facile synthesized bismuth oxychloride nanoparticles (BiOCl NPs) were compared to those of traditional bismuth oxychloride. In addition, the photocatalytic performance of facile-synthesized BiOCl NPs and traditional BiOCl, as applied to the removal of hazardous organic dyes under visible light illumination, is thoroughly investigated. Our results reveal that facile-synthesized BiOCl NPs display strong UV-Vis light adsorption, improved charge carrier mobility and an inhibited rate of charge carrier recombination, when compared to traditional BiOCl. These enhancements result in an improved photocatalytic degradation rate of hazardous organic dyes under UV-Vis irradiance. For instance, the facile-synthesized BiOCl NPs attained 100% degradation of methylene blue and methyl orange dyes in approximately 30 mins under UV-Vis irradiation, against 55% degradation for traditional BiOCl under similar experimental conditions.

Bismuth ferrite dielectric nanoparticles excited at telecom wavelengths as multicolor sources by second, third, and fourth harmonic generation.

PubMed

Riporto, Jérémy; Demierre, Alexis; Kilin, Vasyl; Balciunas, Tadas; Schmidt, Cédric; Campargue, Gabriel; Urbain, Mathias; Baltuska, Andrius; Le Dantec, Ronan; Wolf, Jean-Pierre; Mugnier, Yannick; Bonacina, Luigi

2018-05-03

We demonstrate the simultaneous generation of second, third, and fourth harmonics from a single dielectric bismuth ferrite nanoparticle excited using a telecom fiber laser at 1560 nm. We first characterize the signals associated with different nonlinear orders in terms of spectrum, excitation intensity dependence, and relative signal strengths. Successively, on the basis of the polarization-resolved emission curves of the three harmonics, we discuss the interplay of susceptibility tensor components at different orders and show how polarization can be used as an optical handle to control the relative frequency conversion properties.

A Biological Approach for the Synthesis of Bismuth Nanoparticles: Using Thiolated M13 Phage as Scaffold.

PubMed

Vera-Robles, L Irais; Escobar-Alarcón, Luis; Picquart, Michel; Hernández-Pozos, J Luis; Haro-Poniatowski, Emmanuel

2016-04-05

We report the synthesis of Bi nanoparticles (Bi NPs) using the M13 phage as scaffold. The p8 protein of the phage is functionalized with thiol groups of different lengths, and these thiolated regions act as nucleation centers for Bi(3+) ions. The size distribution, shape, and resilience to oxidation of the Bi NPs depend on the length of the thiol group used. The NPs are characterized by high resolution transmission electron microscopy, Raman, and IR spectroscopies, matrix assisted laser desorption/ionization, and optical absorption. These results show that the nanoparticles are crystalline and have a typical diameter of ∼3.0 nm. The method of preparation presented here is reproducible and implies "greener" conditions than those reported elsewhere. To the best of our knowledge, this is the first report of bismuth nanoparticles synthesized by a biomineralization method.

Influence of gamma ray irradiation on stoichiometry of hydrothermally synthesized bismuth telluride nanoparticles

NASA Astrophysics Data System (ADS)

Abishek, N. S.; Naik, K. Gopalakrishna

2018-05-01

Bismuth telluride (Bi2Te3) nanoparticles were synthesized by the hydrothermal method at 200 °C for 24 h. The synthesized Bi2Te3 nanoparticles were irradiated with gamma rays at doses of 50 kGy and 100 kGy. The structural characterization of the pre-irradiated and post-irradiated samples was carried out by X-ray diffraction technique and was found to have rhombohedral phase having R3 ¯m (166) space group. The X-ray diffraction peaks were found to shift towards lower diffraction angle with gamma ray irradiation. The morphologies and compositions of the grown Bi2Te3 nanoparticles were studied using Field Emission Scanning Electron Microscope and X-ray energy dispersive analysis, respectively. The possible cause for the shift in the X-ray diffraction peaks with gamma ray irradiation has been discussed in the present work.

The effect of reaction temperature on the particle size of bismuth oxide nanoparticles synthesized via hydrothermal method

NASA Astrophysics Data System (ADS)

Zulkifli, Zulfa Aiza; Razak, Khairunisak Abdul; Rahman, Wan Nordiana Wan Abdul

2018-05-01

Bismuth oxide (Bi2O3) nanoparticles have been synthesized at different temperatures from 70 to 120˚C without any subsequent heat treatment using hydrothermal method. The particle size, and crystal structure of as-synthesized particles were investigated by X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Energy-dispersive X-ray spectroscopy (EDX) and Fourier transform Infra-Red (FTIR). The nanoparticles are of a pure moniclinic Bi2O3 phase with rods shape. The average size of nanoparticles increases with the increase of reaction temperature. It was clear that longer reaction temperature allows precipitation completely occured and form larger nanoparticles (NPs). The crystallinity of Bi2O3 also are of high purity even at lower reaction temperature. The FTIR spectrum showed the absorption band at 845 cm-1 which is attributed to Bi-O-Bi bond, and the strong absorption band recorded at 424 cm-1 that is due to the stretching mode of Bi-O.

Synthesis and characterization of lipophilic bismuth dimercaptopropanol nanoparticles and their effects on oral microorganisms growth and biofilm formation

NASA Astrophysics Data System (ADS)

Badireddy, Appala Raju; Hernandez-Delgadillo, Rene; Sánchez-Nájera, Rosa Isela; Chellam, Shankararaman; Cabral-Romero, Claudio

2014-06-01

The increasing prevalence of resistance among pathogenic microorganisms to common antibiotics has become one of the most significant concerns in modern medicine. Nanotechnology offers a new alternative to develop materials with interesting applications in many areas of biological sciences and medicine. While some bismuth derivatives have been employed to treat vomiting, nausea, diarrhea, and stomach pain, the antimicrobial properties of bismuth in its nanoparticulate form have not been extensively studied. The objective of this investigation was to analyze the bactericidal, fungicidal, and antibiofilm activities of bismuth dimercaptopropanol nanoparticles (BisBAL NPs) against oral microbes. The nanoparticles are composed of 18.7 nm crystallites on average and have a rhombohedral structure, agglomerating into chains-like or clusters of small nanoparticles. Our results showed that stable colloidal BisBAL NPs inhibited Streptococcus mutans and Streptococcus gordonii growth by more than 70 % at 0.1 µM, showing a twelve thousand fold higher effectiveness compared with 1.2 mM chlorhexidine, the oral antiseptic most used by dentists. The minimal inhibitory concentration (MIC) of BisBAL NPs for S. mutans and S. gordonii was 5 µM. MIC of BisBAL NPs for Candida albicans was 10 µM. However, 100 µM of BisBAL NPs were required to interfere with planktonic growth of and biofilm formation by a multi-species population of bacteria. Our experiments show that bactericidal activity of BisBAL NPs was similar to antibiotics such as vancomycin and rifampicin. Based on MTT cell viability assays, we hypothesize that BisBAL NPs potentially act on key enzymes, altering their metabolism, and cause cell lysis. All together, these findings show the efficacy of BisBAL NPs as a broad spectrum antimicrobial agent which could reduce antibiotic usage.

Intimate contacted two-dimensional/zero-dimensional composite of bismuth titanate nanosheets supported ultrafine bismuth oxychloride nanoparticles for enhanced antibiotic residue degradation.

PubMed

Liu, Wenwen; Dai, Zhiqiang; Liu, Yi; Zhu, Anquan; Zhong, Donglin; Wang, Juan; Pan, Jun

2018-05-31

Constructing a two-dimensional/zero-dimensional (2D/0D) composite with matched crystal structure, suitable energy band structure as well as intimate contact interface is an effective way to improve carriers separation for achieving highly photocatalytic performance. In this work, a novel bismuth titanate/bismuth oxychloride (Bi 4 Ti 3 O 12 /BiOCl) composite consisting of 2D Bi 4 Ti 3 O 12 nanosheets and 0D BiOCl nanoparticles was constructed for the first time. Germinating ultrafine BiOCl nanoparticles on Bi 4 Ti 3 O 12 nanosheets can provide abundant contact interface and shorten migration distance of photoinduced carriers via two-step synthesis contained molten salt process and facile chemical transformation process. The obtained Bi 4 Ti 3 O 12 /BiOCl 2D/0D composites exhibited enhanced photocatalytic performance for antibiotic tetracycline hydrochloride degradation. The rate constant of optimal Bi 4 Ti 3 O 12 /BiOCl composite was about 4.4 times higher than that of bare Bi 4 Ti 3 O 12 although Bi 4 Ti 3 O 12 /BiOCl composite appeared lesser photoabsorption. The enhanced photocatalytic performance can be mainly ascribed to matched crystal structure, suitable energy band structure and intimate contact interface between Bi 4 Ti 3 O 12 nanosheets and ultrafine BiOCl nanoparticles as well as unique 2D/0D composite structure. Besides, a probable degradation mechanism on the basis of active species trapping experiments, electrochemical impedance spectroscopy, photocurrent responses and energy band structures was proposed. This work may be stretched to other 2D/0D composite photocatalysts construction, which is inspiring for antibiotic residue treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

Facile formation of metallic bismuth/bismuth oxide heterojunction on porous carbon with enhanced photocatalytic activity.

PubMed

Zhang, Liping; Ghimire, Pramila; Phuriragpitikhon, Jenjira; Jiang, Baojiang; Gonçalves, Alexandre A S; Jaroniec, Mietek

2018-03-01

Bismuth/bismuth oxide heterojunction on porous carbon (Bi 0 /Bi 2 O 3 @C) was successfully prepared by a surfactant-assisted sol-gel method. This composite photocatalyst was fabricated by depositing Bi 2 O 3 and metallic bismuth nanoparticles (NPs) on porous carbon sheets. Bi NPs were created by in-situ reduction of Bi 2 O 3 with amorphous carbon. During the synthesis, bismuth and carbon precursors were mixed in different ratios, resulting in distinct amounts of metallic bismuth in the composites. The composites showed large specific surface area and pore volume as well as strong light absorption ability due to the existing carbon. In addition, the plasmonic bismuth NPs were found to behave as a noble metal, which is able to generate hot charge carriers under visible light irradiation. Photocatalytic performance of the Bi 0 /Bi 2 O 3 @C composites was investigated by degradation of methylene blue. It turned out that the composites showed much higher efficiency as compared to bare Bi 2 O 3 , which may be attributed to the synergistic effects of porous structures, improved optical absorption, and surface plasmon resonance. Copyright © 2017 Elsevier Inc. All rights reserved.

Eco-friendly and green synthesis of BiVO4 nanoparticle using microwave irradiation as photocatalayst for the degradation of Alizarin Red S

NASA Astrophysics Data System (ADS)

Abraham, S. Daniel; David, S. Theodore; Bennie, R. Biju; Joel, C.; Kumar, D. Sanjay

2016-06-01

Bismuth vanadate (BiVO4) nanocrystals have been successfully synthesised using microwave-assisted combustion synthesis (MCS), and characterised using Fourier transform infrared (FT-IR) and Raman spectra, surface area analysis (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-ray analysis (EDX), diffused reflectance spectroscopy (DRS) and Photoluminescence (PL) spectroscopy. The XRD results confirmed the formation of monoclinic bismuth vanadate. The formations of BiO & VO43-vibrations were ascertained from FT-IR data. The morphology of hallow internal structural micro entities were confirmed by SEM. The optical properties were determined by DRS and PL spectra. Hence, the influence of the preparation methods on the structure, morphology and optical activities of bismuth vanadate was investigated systematically. Photocatalytic degradation (PCD) of Alizarin Red S (ARS), an effective disrupting chemical in aqueous medium was investigated using BiVO4 nanoparticles. The kinetics of PCD was found to follow pseudo first-order.

In situ study on atomic mechanism of melting and freezing of single bismuth nanoparticles

PubMed Central

Li, Yingxuan; Zang, Ling; Jacobs, Daniel L.; Zhao, Jie; Yue, Xiu; Wang, Chuanyi

2017-01-01

Experimental study of the atomic mechanism in melting and freezing processes remains a formidable challenge. We report herein on a unique material system that allows for in situ growth of bismuth nanoparticles from the precursor compound SrBi2Ta2O9 under an electron beam within a high-resolution transmission electron microscope (HRTEM). Simultaneously, the melting and freezing processes within the nanoparticles are triggered and imaged in real time by the HRTEM. The images show atomic-scale evidence for point defect induced melting, and a freezing mechanism mediated by crystallization of an intermediate ordered liquid. During the melting and freezing, the formation of nucleation precursors, nucleation and growth, and the relaxation of the system, are directly observed. Based on these observations, an interaction–relaxation model is developed towards understanding the microscopic mechanism of the phase transitions, highlighting the importance of cooperative multiscale processes. PMID:28194017

In situ study on atomic mechanism of melting and freezing of single bismuth nanoparticles

NASA Astrophysics Data System (ADS)

Li, Yingxuan; Zang, Ling; Jacobs, Daniel L.; Zhao, Jie; Yue, Xiu; Wang, Chuanyi

2017-02-01

Experimental study of the atomic mechanism in melting and freezing processes remains a formidable challenge. We report herein on a unique material system that allows for in situ growth of bismuth nanoparticles from the precursor compound SrBi2Ta2O9 under an electron beam within a high-resolution transmission electron microscope (HRTEM). Simultaneously, the melting and freezing processes within the nanoparticles are triggered and imaged in real time by the HRTEM. The images show atomic-scale evidence for point defect induced melting, and a freezing mechanism mediated by crystallization of an intermediate ordered liquid. During the melting and freezing, the formation of nucleation precursors, nucleation and growth, and the relaxation of the system, are directly observed. Based on these observations, an interaction-relaxation model is developed towards understanding the microscopic mechanism of the phase transitions, highlighting the importance of cooperative multiscale processes.

In situ study on atomic mechanism of melting and freezing of single bismuth nanoparticles.

PubMed

Li, Yingxuan; Zang, Ling; Jacobs, Daniel L; Zhao, Jie; Yue, Xiu; Wang, Chuanyi

2017-02-13

Experimental study of the atomic mechanism in melting and freezing processes remains a formidable challenge. We report herein on a unique material system that allows for in situ growth of bismuth nanoparticles from the precursor compound SrBi 2 Ta 2 O 9 under an electron beam within a high-resolution transmission electron microscope (HRTEM). Simultaneously, the melting and freezing processes within the nanoparticles are triggered and imaged in real time by the HRTEM. The images show atomic-scale evidence for point defect induced melting, and a freezing mechanism mediated by crystallization of an intermediate ordered liquid. During the melting and freezing, the formation of nucleation precursors, nucleation and growth, and the relaxation of the system, are directly observed. Based on these observations, an interaction-relaxation model is developed towards understanding the microscopic mechanism of the phase transitions, highlighting the importance of cooperative multiscale processes.

Biomolecule-assisted hydrothermal synthesis of silver bismuth sulfide with nanostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaowphong, Sulawan, E-mail: sulawank@gmail.com; Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200

2012-05-15

Silver bismuth sulfide (AgBiS{sub 2}) nanostructures were successfully prepared via a simple biomolecule-assisted hydrothermal synthesis at 200 Degree-Sign C for 12-72 h. Silver nitrate, bismuth nitrate and L-cysteine were used as starting materials. Here, the biomolecule, L-cysteine, was served as the sulfide source and a complexing agent. The products, characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), were cubic AgBiS{sub 2} nanoparticles with a diameter range of about 20-75 nm. It was found that their crystallinity and particle size increased with increasing reaction time. The energy dispersive X-ray spectroscopy (EDX) and inductively coupledmore » plasma optical emission spectrophotometry (ICP-OES) analyses were used to confirm the stoichiometry of AgBiS{sub 2}. The optical band gap of the AgBiS{sub 2} nanoparticles, calculated from UV-vis spectra, was 3.0 eV which indicated a strong blue shift because of the quantum confinement effect. A possible formation mechanism of the AgBiS{sub 2} nanoparticles was also discussed. - Graphical abstract: The optical band gap of the as-prepared AgBiS{sub 2} nanoparticles displays a strong blue shift comparing to the 2.46 eV of bulk AgBiS{sub 2} caused by the quantum confinement effects. Highlights: Black-Right-Pointing-Pointer A simple biomolecule-assisted hydrothermal method is developed to prepare AgBiS{sub 2}. Black-Right-Pointing-Pointer L-Cysteine is served as the sulfide source and a complexing agent. Black-Right-Pointing-Pointer Increase in band gap of the AgBiS{sub 2} nanoparticles attributes to the quantum confinement effects.« less

Physicochemical properties of calcium silicate cements associated with microparticulate and nanoparticulate radiopacifiers.

PubMed

Bosso-Martelo, Roberta; Guerreiro-Tanomaru, Juliane M; Viapiana, Raqueli; Berbert, Fabio Luiz C; Duarte, Marco Antonio Hungaro; Tanomaru-Filho, Mário

2016-01-01

The objective of this paper was to evaluate the physicochemical properties of calcium silicate cements with different chemical compositions, associated with radiopacifying agents. Mineral trioxide aggregate (MTA) Angelus, calcium silicate cement with additives (CSC), and resinous calcium silicate cement (CSCR) were evaluated, with the addition of the following radiopacifiers: microparticles (micro) or nanoparticles (nano) of zirconium oxide (ZrO(2)), niobium oxide (Nb(2)O(5)), bismuth oxide (Bi(2)O(3)), or calcium tungstate (CaWO(4)). Setting time was evaluated using Gilmore needles. Solubility was determined after immersion in water. The pH and calcium ion release were analyzed after 3, 12, and 24 h and 7, 14, and 21 days. The data obtained were submitted to analysis of variance and Tukey's test, at a level of significance of 5 %. CSC + CaWO(4) and CSCR + ZrO(2) micro, Nb(2)O(5) and CaWO(4) presented results similar to MTA, with a shorter final setting time than the other associations. CSC and CSCR+ ZrO(2) micro presented a higher degree of flow. All the cements evaluated presented low solubility. The materials presented alkaline pH and released calcium ions. ZrO(2) micro radiopacifier may be considered a potential substitute for Bi(2)O(3) when associated with CSC or CSCR. The proposed materials, especially when associated with ZrO(2), are potential materials for use as alternatives to MTA.

Robust, heat-resistant and multifunctional superhydrophobic coating of carbon microflowers with molybdenum trioxide nanoparticles.

PubMed

Wu, Yang; Zhao, Meiyun; Guo, Zhiguang

2017-11-15

Superhydrophobic materials have triggered large interest due to their widespread applications, such as self-cleaning, corrosion resistance, anti-icing, and oil/water separation. However, suffering from weak mechanical strength, plenty of superhydrophobic materials are limited in practical application. Herein, we prepared hierarchical carbon microflowers (CMF) dispersed with molybdenum trioxide (MoO 3 ) nanoparticles (MoO 3 /CMF) via a two-step preparation method. Taking advantage of high-adhesion epoxy resin and the modification with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PDES), the modified MoO 3 /CMF (PDES-MoO 3 /CMF) coating on various substrates shows great waterproof ability, excellent chemical stability, good mechanical durability, and self-cleaning property. More significantly, the prepared PDES-MoO 3 /CMF powder with high thermal stability (250°C) can be used for oil/water separation due to its special flower-like structure and superhydrophobicity/superoleophilicity. All of these advantages endow the superhydrophobic powders with huge potential in the practical applications. Copyright © 2017 Elsevier Inc. All rights reserved.

Superior electro-optic response in multiferroic bismuth ferrite nanoparticle doped nematic liquid crystal device

PubMed Central

Nayek, Prasenjit; Li, Guoqiang

2015-01-01

A superior electro-optic (E-O) response has been achieved when multiferroic bismuth ferrite (BiFeO3/BFO) nanoparticles (NPs) were doped in nematic liquid crystal (NLC) host E7 and the LC device was addressed in the large signal regime by an amplitude modulated square wave signal at the frequency of 100 Hz. The optimized concentration of BFO is 0.15 wt%, and the corresponding total optical response time (rise time + decay time) for a 5 μm-thick cell is 2.5 ms for ~7 Vrms. This might be exploited for the construction of adaptive lenses, modulators, displays, and other E-O devices. The possible reason behind the fast response time could be the visco-elastic constant and restoring force imparted by the locally ordered LCs induced by the multiferroic nanoparticles (MNPs). Polarized optical microscopic textural observation shows that the macroscopic dislocation-free excellent contrast have significant impact on improving the image quality and performance of the devices. PMID:26041701

Synthesis and evaluation of lead telluride/bismuth antimony telluride nanocomposites for thermoelectric applications

NASA Astrophysics Data System (ADS)

Ganguly, Shreyashi; Zhou, Chen; Morelli, Donald; Sakamoto, Jeffrey; Uher, Ctirad; Brock, Stephanie L.

2011-12-01

Heterogeneous nanocomposites of p-type bismuth antimony telluride (Bi 2- xSb xTe 3) with lead telluride (PbTe) nanoinclusions have been prepared by an incipient wetness impregnation approach. The Seebeck coefficient, electrical resistivity, thermal conductivity and Hall coefficient were measured from 80 to 380 K in order to investigate the influence of PbTe nanoparticles on the thermoelectric performance of nanocomposites. The Seebeck coefficients and electrical resistivities of nanocomposites decrease with increasing PbTe nanoparticle concentration due to an increased hole concentration. The lattice thermal conductivity decreases with the addition of PbTe nanoparticles but the total thermal conductivity increases due to the increased electronic thermal conductivity. We conclude that the presence of nanosized PbTe in the bulk Bi 2- xSb xTe 3 matrix results in a collateral doping effect, which dominates transport properties. This study underscores the need for immiscible systems to achieve the decreased thermal transport properties possible from nanostructuring without compromising the electronic properties.

[Endodontics in motion: new concepts, materials and techniques 1. Hydraulic Calcium Silicate Cements].

PubMed

Moinzadeh, A T; Jongsma, L; de Groot-Kuin, D; Cristescu, R; Neirynck, N; Camilleri, J

2015-01-01

Hydraulic Calcium Silicate Cements (HCSCs) constitute a group of materials that have become increasingly popular in endodontics since the introduction of Mineral Trioxide Aggregate (MTA) in the 1990s. MTA is Portland cement to which bismuth oxide has been added to increase its radiopacity. The most important property of MTA is its capacity to set in water or a humid environment. However, MTA also has important limitations, for example, it's difficult to work with and can discolour teeth. Recently, numerous products based on HCSC chemistry, which can be considered as modifications of MTA intended to reduce its limitations, have become available on the market. Despite their potential advantages, all of these materials have their own specific limitations that are currently insufficiently known and investigated.

Solar light-driven photocatalysis using mixed-phase bismuth ferrite (BiFeO3/Bi25FeO40) nanoparticles for remediation of dye-contaminated water: kinetics and comparison with artificial UV and visible light-mediated photocatalysis.

PubMed

Kalikeri, Shankramma; Shetty Kodialbail, Vidya

2018-05-01

Mixed-phase bismuth ferrite (BFO) nanoparticles were prepared by co-precipitation method using potassium hydroxide as the precipitant. X-ray diffractogram (XRD) of the particles showed the formation of mixed-phase BFO nanoparticles containing BiFeO 3 /Bi 25 FeO 40 phases with the crystallite size of 70 nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the formation of quasi-spherical particles. The BFO nanoparticles were uniform sized with narrow size range and with the average hydrodynamic diameter of 76 nm. The band gap energy of 2.2 eV showed its ability to absorb light even in the visible range. Water contaminated with Acid Yellow (AY-17) and Reactive Blue (RB-19) dye was treated by photocatalysis under UV, visible, and solar light irradiation using the BFO nanoparticles. The BFO nanoparticles showed maximum photocatalytical activity under solar light as compared to UV and visible irradiations, and photocatalysis was favored under acidic pH. Complete degradation of AY-17 dyes and around 95% degradation of RB-19 could be achieved under solar light at pH 5. The kinetics of degradation followed the Langmuir-Hinshelhood kinetic model showing that the heterogeneous photocatalysis is adsorption controlled. The findings of this work prove the synthesized BFO nanoparticles as promising photocatalysts for the treatment of dye-contaminated industrial wastewater.

Aerobic method for the synthesis of nearly size-monodisperse bismuth nanoparticles from a redox non-innocent precursor

NASA Astrophysics Data System (ADS)

Winter, H.; Christopher-Allison, E.; Brown, A. L.; Goforth, A. M.

2018-04-01

Herein, we report an aerobic synthesis method to produce bismuth nanoparticles (Bi NPs) with average diameters in the range 40-80 nm using commercially available bismuth triiodide (BiI3) as the starting material; the method uses only readily available chemicals and conventional laboratory equipment. Furthermore, size data from replicates of the synthesis under standard reaction conditions indicate that this method is highly reproducible in achieving Bi NP populations with low standard deviations in the mean diameters. We also investigated the mechanism of the reaction, which we determined results from the reduction of a soluble alkylammonium iodobismuthate precursor species formed in situ. Under appropriate concentration conditions of iodobismuthate anion, we demonstrate that burst nucleation of Bi NPs results from reduction of Bi3+ by the coordinated, redox non-innocent iodide ligands when a threshold temperature is exceeded. Finally, we demonstrate phase transfer and silica coating of the Bi NPs, which results in stable aqueous colloids with retention of size, morphology, and colloidal stability. The resultant, high atomic number, hydrophilic Bi NPs prepared using this synthesis method have potential for application in emerging x-ray contrast and x-ray therapeutic applications.

Tungsten trioxide nanoplate array supported platinum as a highly efficient counter electrode for dye-sensitized solar cells.

PubMed

Song, Dandan; Cui, Peng; Zhao, Xing; Li, Meicheng; Chu, Lihua; Wang, Tianyue; Jiang, Bing

2015-03-19

A tungsten trioxide (WO₃) nanoplate array is fabricated directly on the FTO/glass substrate and used as a platinum (Pt) nanoscale supporter for a highly efficient and low Pt-consumption counter electrode (CE) in dye-sensitized solar cells (DSCs). A Pt/WO₃ composite structure, with Pt nanoparticles having a diameter of 2-3 nm, increases the electrochemical catalytic activity in catalyzing the reduction of triiodide. Accordingly, the power conversion efficiency is increased from less than 1% for WO₃ CE and 8.1% for Pt CE, respectively, to 8.9% for Pt/WO₃ CE. Moreover, the use of Pt/WO₃ CE can dramatically reduce the consumption of scarce Pt material, with a relatively low Pt-loading of ∼2 μg cm(-2), while maintaining a much better performance. The excellent performance of Pt/WO₃ CE is attributed to the efficient electron injection and transport via WO₃ supporters, as well as the nanostructure array morphology of WO₃ for deposition of fine Pt nanoparticles. This work provides an approach for developing highly catalytic and low-cost Pt based CEs, which also has implications for the development of Pt/WO₃ nanoplate arrays for other applications.

Inorganic phosphate-triggered release of anti-cancer arsenic trioxide from a self-delivery system: an in vitro and in vivo study

NASA Astrophysics Data System (ADS)

Chen, Fei-Yan; Yi, Jing-Wei; Gu, Zhe-Jia; Tang, Bin-Bing; Li, Jian-Qi; Li, Li; Kulkarni, Padmakar; Liu, Li; Mason, Ralph P.; Tang, Qun

2016-03-01

On-demand drug delivery is becoming feasible via the design of either exogenous or endogenous stimulus-responsive drug delivery systems. Herein we report the development of gadolinium arsenite nanoparticles as a self-delivery platform to store, deliver and release arsenic trioxide (ATO, Trisenox), a clinical anti-cancer drug. Specifically, unloading of the small molecule drug is triggered by an endogenous stimulus: inorganic phosphate (Pi) in the blood, fluid, and soft or hard tissue. Kinetics in vitro demonstrated that ATO is released with high ON/OFF specificity and no leakage was observed in the silent state. The nanoparticles induced tumor cell apoptosis, and reduced cancer cell migration and invasion. Plasma pharmacokinetics verified extended retention time, but no obvious disturbance of phosphate balance. Therapeutic efficacy on a liver cancer xenograft mouse model was dramatically potentiated with reduced toxicity compared to the free drug. These results suggest a new drug delivery strategy which might be applied for ATO therapy on solid tumors.On-demand drug delivery is becoming feasible via the design of either exogenous or endogenous stimulus-responsive drug delivery systems. Herein we report the development of gadolinium arsenite nanoparticles as a self-delivery platform to store, deliver and release arsenic trioxide (ATO, Trisenox), a clinical anti-cancer drug. Specifically, unloading of the small molecule drug is triggered by an endogenous stimulus: inorganic phosphate (Pi) in the blood, fluid, and soft or hard tissue. Kinetics in vitro demonstrated that ATO is released with high ON/OFF specificity and no leakage was observed in the silent state. The nanoparticles induced tumor cell apoptosis, and reduced cancer cell migration and invasion. Plasma pharmacokinetics verified extended retention time, but no obvious disturbance of phosphate balance. Therapeutic efficacy on a liver cancer xenograft mouse model was dramatically potentiated with reduced toxicity compared to the free drug. These results suggest a new drug delivery strategy which might be applied for ATO therapy on solid tumors. Electronic supplementary information (ESI) available: HRTEM image and electron diffraction pattern of individual GdAsOx NPs, cell viability measurements after 48 and 72 hours of incubation, body weight change curves, hematology curves, liver function curves, and renal function curves. See DOI: 10.1039/c6nr00536e

Evaluation of the radiopacity of calcium silicate cements containing different radiopacifiers.

PubMed

Camilleri, J; Gandolfi, M G

2010-01-01

To identify the suitable ratio of alternative radiopacifiers to impart the necessary radiopacity to calcium silicate cements (CSC) and assess the purity of the radiopacifying agents. Alternative radiopacifying materials for incorporation into CSC included barium sulphate, titanium oxide, zinc oxide, gold powder and silver/tin alloy. The chemical composition of the alternative radipacifying materials and bismuth oxide, which is used in mineral trioxide aggregate (MTA), was determined using energy dispersive X-ray analysis. In addition, using an aluminium step-wedge and densitometer, the radiopacity of each material was evaluated as recommended by international standards. The optical density was compared with the relevant thickness of aluminium (Al). A commercial MTA and CSC were used as controls. Statistical analysis comparing the radiodensity of the different cements to MTA was performed using anova with P = 0.05 and post hoc Tukey test. All percentage replacements of bismuth oxide, gold and silver-tin alloy powder, and the 25% and 30% replacements with barium sulphate and zinc oxide had radiopacities greater than 3 mm thickness of aluminium (Al) recommended by ISO 6876 (2002). The 25% replacement of cement with gold powder and 20% replacement of cement with silver/tin alloy powder exhibited radiopacity values of 8.04 mm Al and 7.52 mm Al, respectively, similar to MTA (P > 0.05). The cement replaced with 20% bismuth oxide showed a radiopacity of 6.83 mm Al, lower than MTA (P = 0.003). Silver/tin alloy and gold powder imparted the necessary radiopacity to a calcium silicate-based cement. Barium sulphate was also a suitable radiopacifier together with a lower concentration of silver/tin alloy and gold powder that achieved the radiodensity recommended by ISO 6876. Further research is required to investigate the broader properties of the calcium silicate-based cement with the different radiopacifiers.

Radiopacity of Mineral Trioxide Aggregate with and without Inclusion of Silver Nanoparticles.

PubMed

Mendes, Mariana Ss; Resende, Leonardo D; Pinto, Cláudia A; Raldi, Denise P; Cardoso, Flavia Gr; Habitante, Sandra M

2017-06-01

The aim of this study was to investigate the inclusion of silver nanoparticles (Ag NPs) in the mineral trioxide aggregate (MTA) composition to know which changes will result in the radiopacity of the material. The experiment was performed according to the American National Standard Institute/American Dental Association specification no. 57/2000 and ISO 6876/2001. Five plates with five holes measuring 1 mm in depth and 5 mm in internal diameter were filled according to the different experimental groups as follows: white mineral trioxide aggregate (WMTA) + NP50 - W MTA with liquid Ag NP 50 ppm, WMTA + NP30 - W MTA with liquid Ag NP 30 ppm, WMTA + NP22 - W MTA with liquid Ag NP 22 ppm, WMTA + NPP - white MTA with liquid Ag NP and powder 1%, WMTA (control). After filling the plates, they were kept in an incubator at 37°C in relative humidity for setting. Each sample was positioned along an aluminum step-wedge placed above the Opteo digital sensor system. The image was divided into four quadrants, and three readings were made for each quadrant to render the average of each quadrant. The resulting data were submitted to Kruskal-Wallis and Dunn's tests. The results showed statistically significant differences between WMTA + NP30, WMTA + NP22, and WMTA + NPP interactions compared with WMTA (control) (p < 0.05). The radiopacity was in descending order: WMTA + NPP, WMTA + NP22, WMTA + NP30, MTA + NP50, and WMTA. Silver NPs changed the radiopacity of WMTA, being more evident in WMTA + NP powder at 1% weight. The low radiopacity of MTA makes it difficult for any radiographic observation. The Ag NPs appear as an alternative, being an excellent radiopacifier as they have excellent antimicrobial property and relatively low toxicity.

Shape-controlled solvothermal synthesis of bismuth subcarbonate nanomaterials

NASA Astrophysics Data System (ADS)

Cheng, Gang; Yang, Hanmin; Rong, Kaifeng; Lu, Zhong; Yu, Xianglin; Chen, Rong

2010-08-01

Much effort has been devoted to the synthesis of novel nanostructured materials because of their unique properties and potential applications. Bismuth subcarbonate ((BiO) 2CO 3) is one of commonly used antibacterial agents against Helicobacter pylori ( H. pylori). Different (BiO) 2CO 3 nanostructures such as cube-like nanoparticles, nanobars and nanoplates, were fabricated from bismuth nitrate via a simple solvothermal method. The nanostructures were characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that the solvents and precursors have an influence on the morphologies of (BiO) 2CO 3 nanostructures. The possible formation mechanism of different (BiO) 2CO 3 nanostructures fabricated under different conditions was also discussed.

Easy synthesis of bismuth iron oxide nanoparticles as photocatalyst for solar hydrogen generation from water

NASA Astrophysics Data System (ADS)

Deng, Jinyi

In this study, high purity bismuth iron oxide (BiFeO3/BFO) nanoparticles of size 50-80 nm have been successfully synthesized by a simple sol-gel method using urea and polyvinyl alcohol at low temperature. X-ray diffraction (XRD) measurement is used to optimize the synthetic process to get highly crystalline and pure phase material. Diffuse reflectance ultraviolet-visible (DRUV-Vis) spectrum indicates that the absorption cut-off wavelength of the nanoparticles is about 620 nm, corresponding to an energy band gap of 2.1 eV. Compared to BaTiO3, BFO has a better degradation of methyl orange under light radiation. Also, photocatalytic tests prove this material to be efficient towards water splitting under simulated solar light to generate hydrogen. The simple synthetic methodology adopted in this paper will be useful in developing low-cost semiconductor materials as effective photocatalysts for hydrogen generation. Photocatalytic tests followed by gas chromatography (GC) analyses show that BiFeO3 generates three times more hydrogen than commercial titania P25 catalyst under the same experimental conditions.

Bismuth-based oxide semiconductors: Mild synthesis and practical applications

NASA Astrophysics Data System (ADS)

Timmaji, Hari Krishna

In this dissertation study, bismuth based oxide semiconductors were prepared using 'mild' synthesis techniques---electrodeposition and solution combustion synthesis. Potential environmental remediation and solar energy applications of the prepared oxides were evaluated. Bismuth vanadate (BiVO4) was prepared by electrodeposition and solution combustion synthesis. A two step electrosynthesis strategy was developed and demonstrated for the first time. In the first step, a Bi film was first electrodeposited on a Pt substrate from an acidic BiCl3 medium. Then, this film was anodically stripped in a medium containing hydrolyzed vanadium precursor, to generate Bi3+, and subsequent BiVO4 formation by in situ precipitation. The photoelectrochemical data were consistent with the in situ formation of n-type semiconductor films. In the solution combustion synthesis procedure, BiVO4 powders were prepared using bismuth nitrate pentahydrate as the bismuth precursor and either vanadium chloride or vanadium oxysulfate as the vanadium precursor. Urea, glycine, or citric acid was used as the fuel. The effect of the vanadium precursor on the photocatalytic activity of combustion synthesized BiVO 4 was evaluated in this study. Methyl orange was used as a probe to test the photocatalytic attributes of the combustion synthesized (CS) samples, and benchmarked against a commercial bismuth vanadate sample. The CS samples showed superior activity to the commercial benchmark sample, and samples derived from vanadium chloride were superior to vanadium oxysulfate counterparts. The photoelectrochemical properties of the various CS samples were also studied and these samples were shown to be useful both for environmental photocatalytic remediation and water photooxidation applications. Silver bismuth tungstate (AgBiW2O8) nanoparticles were prepared for the first time by solution combustion synthesis by using silver nitrate, bismuth nitrate, sodium tungstate as precursors for Ag, Bi, and W respectively and urea as the fuel. The photocatalytic activity of these nanoparticles was superior to a sample prepared by solid-state synthesis. The combustion-synthesized particles were subsequently modified with Pt catalyst islands using a photodeposition technique and then used for the photo-generation of syngas (CO + H2). Formic acid was used in these experiments for in situ generation of CO2 and its subsequent reduction to CO. In the absence of Pt modification, H2 was not obtained. These results were compared with those obtained with acetic acid in place of formic acid, and finally the mechanistic pathways for syngas and methane photogeneration are presented.

PEG-phospholipid-encapsulated bismuth sulfide and CdSe/ZnS quantum dot core-shell nanoparticle and its computed tomography/fluorescence performance

NASA Astrophysics Data System (ADS)

Chen, Jun; Yang, Xiao-Quan; Qin, Meng-Yao; Zhang, Xiao-Shuai; Xuan, Yang; Zhao, Yuan-Di

2015-11-01

In this paper, polyethylene glycol-phospholipid structure is used to synthesize hybrid cluster of 40-50 nm diameter that contains hydrophobic bismuth sulfide nanoparticles and CdSe/ZnS quantum dots. The composite probe's toxicity, CT imaging, and fluorescence imaging performance are also studied. Experimental results show that the nanocomposite hybrid cluster has obvious CT contrast enhancement and fluorescence imaging capability in vitro even after cellular uptake. It gives a CT number of 700 (Hounsfield units) at 15 mg/mL, higher than that of the current iobitridol CT contrast agent. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide experiment reveals that it has low cytotoxicity at concentration up to of 3.14 mg/mL of Bi, indicating the composite probe has potential ability for CT and fluorescence bimodal imaging.

Bismuth Oxide Nanoparticles Partially Substituted with EuIII, MnIV, and SiIV: Structural, Spectroscopic, and Optical Findings.

PubMed

Ortiz-Quiñonez, José-Luis; Zumeta-Dubé, Inti; Díaz, David; Nava-Etzana, Noel; Cruz-Zaragoza, Epifanio; Santiago-Jacinto, Patricia

2017-03-20

Interest in nanostructured partially substituted bismuth oxides has been increasing over the last years. Research on new synthesis methods, properties, and possible uses for these oxides is needed. The objective of this paper is to synthesize β-Bi 2 O 3 , β-Bi 2 O 3 :Eu 3+ , β-Bi 2 O 3 :Mn 4+ , Bi 12 Bi 0.8 O 19.2 , Bi 12 Bi 0.8 O 19.2 /Li + , Bi 12 MnO 20 , and Bi 12 SiO 20 nanoparticles and to investigate their structural, spectroscopic, and optical changes. Some of the causes that generated their properties are also discussed. These materials are important because the doping or partial substitution of bismuth oxide with these cations (Eu 3+ , Mn 4+ , and Si 4+ ) modifies some properties such as optical absorption, reactivity toward CO 2 , among others. X-ray diffraction (in powders), high-resolution transmission electron microscopy, Fourier transform infrared (FTIR), resonance Raman scattering, diffuse reflectance, and solid-state magic-angle-spinning 29 Si NMR were used for the characterization of the synthesized materials. We found that partial substitution of yellow Bi 12 Bi 0.8 O 19.2 with Mn 4+ and Si 4+ changed the color to green and whitish, respectively. New bands in the Raman scattering and FTIR spectra of these oxides are deeply discussed. Raman scattering spectroscopy was a valuable and reliable technique to detect the Eu 3+ and Mn 4+ cations as dopants in the bismuth oxides. The 29 Si chemical shift (δ) in Bi 12 SiO 20 was -78.16 ppm, whereas in SiO 2 , it was around -110 ppm. This considerable shift in Bi 12 SiO 20 occurred because of an increased shielding of the Si nucleus in the Si(O) 4 tetrahedron. This shielding was provided by the low-electronegativity and highly polarizable Bi cations. The isovalent doping of β-Bi 2 O 3 nanoparticles with Eu 3+ enhanced their thermal stability over 400 °C. Variation in the optical absorption and reactivity toward the acidic CO 2 molecule of the partially substituted bismuth oxides was explained on the basis of the optical basicity and ionic-covalent parameter concepts. Some possible uses for the synthesized oxides are suggested.

Li3PO4 Matrix Enables a Long Cycle Life and High Energy Efficiency Bismuth-Based Battery.

PubMed

Sun, Chuan-Fu; Hu, Junkai; Wang, Peng; Cheng, Xi-Yuan; Lee, Sang Bok; Wang, YuHuang

2016-09-14

Bismuth is a lithium-ion battery anode material that can operate at an equilibrium potential higher than graphite and provide a capacity twice as high as that of Li4Ti5O12, making it intrinsically free from lithium plating that may cause catastrophic battery failure. However, the potential of bismuth is hampered by its inferior cyclability (limited to tens of cycles). Here, we propose an "ion conductive solid-state matrix" approach to address this issue. By homogeneously confining bismuth nanoparticles in a solid-state γ-Li3PO4 matrix that is electrochemically formed in situ, the resulting composite anode exhibits a reversible capacity of 280 mA hours per gram (mA h/g) at a rate of 100 mA/g and a record cyclability among bismuth-based anodes up to 500 cycles with a capacity decay rate of merely 0.071% per cycle. We further show that full-cell batteries fabricated from this composite anode and commercial LiFePO4 cathode deliver a stable cell voltage of ∼2.5 V and remarkable energy efficiency up to 86.3%, on par with practical batteries (80-90%). This work paves a way for harnessing bismuth-based battery chemistry for the design of high capacity, safer lithium-ion batteries to meet demanding applications such as electric vehicles.

Facile synthesis of light harvesting semiconductor bismuth oxychloride nano photo-catalysts for efficient removal of hazardous organic pollutants

PubMed Central

Seddigi, Zaki S.; Baig, Umair; Ahmed, Saleh A.; Abdulaziz, M. A.; Danish, Ekram Y.; Khaled, Mazen M.; Lais, Abul

2017-01-01

In the present work, bismuth oxychloride nanoparticles–a light harvesting semiconductor photocatalyst–were synthesized by a facile hydrolysis route, with sodium bismuthate and hydroxylammonium chloride as the precursor materials. The as-synthesized semiconductor photocatalysts were characterized using X-ray diffraction analysis, Fourier transform infra-red spectroscopy, Raman spectroscopy, Field emission scanning electron microscopy, X-ray photoelectron spectroscopy and Photoluminescence spectroscopy techniques. The crystal structure, morphology, composition, and optical properties of these facile synthesized bismuth oxychloride nanoparticles (BiOCl NPs) were compared to those of traditional bismuth oxychloride. In addition, the photocatalytic performance of facile-synthesized BiOCl NPs and traditional BiOCl, as applied to the removal of hazardous organic dyes under visible light illumination, is thoroughly investigated. Our results reveal that facile-synthesized BiOCl NPs display strong UV-Vis light adsorption, improved charge carrier mobility and an inhibited rate of charge carrier recombination, when compared to traditional BiOCl. These enhancements result in an improved photocatalytic degradation rate of hazardous organic dyes under UV-Vis irradiance. For instance, the facile-synthesized BiOCl NPs attained 100% degradation of methylene blue and methyl orange dyes in approximately 30 mins under UV-Vis irradiation, against 55% degradation for traditional BiOCl under similar experimental conditions. PMID:28245225

Color stability, radiopacity, and chemical characteristics of white mineral trioxide aggregate associated with 2 different vehicles in contact with blood.

PubMed

Guimarães, Bruno Martini; Tartari, Talita; Marciano, Marina Angélica; Vivan, Rodrigo Ricci; Mondeli, Rafael Francisco Lia; Camilleri, Josette; Duarte, Marco Antonio Hungaro

2015-06-01

Discoloration of mineral trioxide aggregate (MTA) can be exacerbated by the interaction of the cement with body fluids such as blood. This study aimed to analyze the color alteration, chemical characteristics, and radiopacity of MTA manipulated with 2 different vehicles after immersion in blood or distilled water (DW). MTA mixed with 100% DW or 80% DW/20% propylene glycol (PG) as vehicles were placed into rubber rings and incubated at 37°C and 100% relative humidity until set. Color assessment and scanning electron microscopy/energy-dispersive spectroscopy analysis were performed after setting and repeated after 7, 15, and 30 days after immersion in blood and DW. Statistical analysis for color alteration and radiopacity was performed using nonparametric Kruskal-Wallis and Dunn tests (P < .05). When 80% DW/20% PG was used as the vehicle, significantly lower color alterations were observed for all time periods compared with 100% DW when immersed in blood (P < .05). All surfaces displayed morphologic changes after immersion in both media because of loss of bismuth. A decrease in radiopacity was observed over time in all groups, with a statistically significant difference after 30 days for groups DW immersed in blood and 80% DW/20% immersed in both media (P < .05). The ratio of 80% DW/20% PG as a vehicle for MTA results in a lower color alteration when in contact with blood. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Tungsten trioxide nanoplate array supported platinum as a highly efficient counter electrode for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Song, Dandan; Cui, Peng; Zhao, Xing; Li, Meicheng; Chu, Lihua; Wang, Tianyue; Jiang, Bing

2015-03-01

A tungsten trioxide (WO3) nanoplate array is fabricated directly on the FTO/glass substrate and used as a platinum (Pt) nanoscale supporter for a highly efficient and low Pt-consumption counter electrode (CE) in dye-sensitized solar cells (DSCs). A Pt/WO3 composite structure, with Pt nanoparticles having a diameter of 2-3 nm, increases the electrochemical catalytic activity in catalyzing the reduction of triiodide. Accordingly, the power conversion efficiency is increased from less than 1% for WO3 CE and 8.1% for Pt CE, respectively, to 8.9% for Pt/WO3 CE. Moreover, the use of Pt/WO3 CE can dramatically reduce the consumption of scarce Pt material, with a relatively low Pt-loading of ~2 μg cm-2, while maintaining a much better performance. The excellent performance of Pt/WO3 CE is attributed to the efficient electron injection and transport via WO3 supporters, as well as the nanostructure array morphology of WO3 for deposition of fine Pt nanoparticles. This work provides an approach for developing highly catalytic and low-cost Pt based CEs, which also has implications for the development of Pt/WO3 nanoplate arrays for other applications.A tungsten trioxide (WO3) nanoplate array is fabricated directly on the FTO/glass substrate and used as a platinum (Pt) nanoscale supporter for a highly efficient and low Pt-consumption counter electrode (CE) in dye-sensitized solar cells (DSCs). A Pt/WO3 composite structure, with Pt nanoparticles having a diameter of 2-3 nm, increases the electrochemical catalytic activity in catalyzing the reduction of triiodide. Accordingly, the power conversion efficiency is increased from less than 1% for WO3 CE and 8.1% for Pt CE, respectively, to 8.9% for Pt/WO3 CE. Moreover, the use of Pt/WO3 CE can dramatically reduce the consumption of scarce Pt material, with a relatively low Pt-loading of ~2 μg cm-2, while maintaining a much better performance. The excellent performance of Pt/WO3 CE is attributed to the efficient electron injection and transport via WO3 supporters, as well as the nanostructure array morphology of WO3 for deposition of fine Pt nanoparticles. This work provides an approach for developing highly catalytic and low-cost Pt based CEs, which also has implications for the development of Pt/WO3 nanoplate arrays for other applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06787h

Development of bismuth tellurium selenide nanoparticles for thermoelectric applications via a chemical synthetic process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Cham; Department of Chemical Engineering, Pohang University of Science and Technology; Kim, Dong Hwan

2011-03-15

Research highlights: {yields} We synthesized a Bi{sub 2}Te{sub y}Se{sub 3-y} nano-compound via a chemical synthetic process. {yields} The compound was sintered to achieve an average grain size of about 300 nm. {yields} The resulting sintered body showed very low thermal conductivity. It is likely caused by the vigorous phonon scattering of the nano-sized grains. -- Abstract: Bismuth tellurium selenide (Bi{sub 2}Te{sub y}Se{sub 3-y}) nanoparticles for thermoelectric applications are successfully prepared via a water-based chemical reaction under atmospheric conditions. The nanostructured compound is prepared using a complexing agent (ethylenediaminetetraacetic acid) and a reducing agent (ascorbic acid) to stabilize the bismuth precursormore » (Bi(NO{sub 3}){sub 3}) in water and to favor the reaction with reduced sources of tellurium and selenium. The resulting powder is smaller than ca. 100 nm and has a crystalline structure corresponding to the rhombohedral Bi{sub 2}Te{sub 2.7}Se{sub 0.3}. The nanocrystalline powder is sintered via a spark plasma sintering process to obtain a sintered body composed of nano-sized grains. Important transport properties of the sintered body are measured to calculate its most important characteristic, the thermoelectric performance. The results demonstrate a relationship between the nanostructure of the sintered body and its thermal conductivity.« less

Surfactant-assisted growth and properties of rare-earth arsenide InGaAs nanocomposites for terahertz generation

NASA Astrophysics Data System (ADS)

Salas, R.; Guchhait, S.; McNicholas, K. M.; Sifferman, S. D.; Dasika, V. D.; Jung, D.; Krivoy, E. M.; Lee, M. L.; Bank, S. R.

2016-05-01

We explore the effects of surfactant-mediated epitaxy on the structural, electrical, and optical properties of fast metal-semiconductor superlattice photoconductors. Specifically, application of a bismuth flux during growth was found to significantly improve the properties of superlattices of LuAs nanoparticles embedded in In0.53Ga0.47As. These improvements are attributed to the enhanced structural quality of the overgrown InGaAs over the LuAs nanoparticles. The use of bismuth enabled a 30% increase in the number of monolayers of LuAs that could be deposited before the InGaAs overgrowth degraded. Dark resistivity increased by up to ˜15× while carrier mobility remained over 2300 cm2/V-s and carrier lifetimes were reduced by >2× at comparable levels of LuAs deposition. These findings demonstrate that surfactant-mediated epitaxy is a promising approach to enhance the properties of ultrafast photoconductors for terahert generation.

Wet-chemical synthesis of different bismuth telluride nanoparticles using metal organic precursors - single source vs. dual source approach.

PubMed

Bendt, Georg; Weber, Anna; Heimann, Stefan; Assenmacher, Wilfried; Prymak, Oleg; Schulz, Stephan

2015-08-28

Thermolysis of the single source precursor (Et2Bi)2Te in DIPB at 80 °C yielded phase-pure Bi4Te3 nanoparticles, while mixtures of Bi4Te3 and elemental Bi were formed at higher temperatures. In contrast, cubic Bi2Te particles were obtained by thermal decomposition of Et2BiTeEt in DIPB. Moreover, a dual source approach (hot injection method) using the reaction of Te(SiEt3)2 and Bi(NMe2)3 was applied for the synthesis of different pure Bi-Te phases including Bi2Te, Bi4Te3 and Bi2Te3, which were characterized by PXRD, REM, TEM and EDX. The influence of reaction temperature, precursor molar ratio and thermolysis conditions on the resulting material phase was verified. Moreover, reactions of alternate bismuth precursors such as Bi(NEt2)3, Bi(NMeEt)3 and BiCl3 with Te(SiEt3)2 were investigated.

Manifestation of weak ferromagnetism and photocatalytic activity in bismuth ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Sakar, M.; Balakumar, S.; Saravanan, P.; Jaisankar, S. N.

2013-02-01

Bismuth ferrite (BFO) nanoparticles were synthesized by auto-ignition technique with and without adding ignition fuel such as citric acid. The presence of citric acid in the reaction mixture yielded highly-magnetic BFO/γ-Fe2O3 nanocomposite. When this composite was annealed to 650°C, a single phase BFO was formed with average crystallite size of 50 nm and showed weak ferromagnetic behavior. Conversely, the phase pure BFO prepared without adding citric acid exhibited antiferromagnetism because of its larger crystallite size of around 70 nm. The visible-light driven photocatalytic activity of both the pure BFO and BFO/γ-Fe2O3 nanocomposite were examined by degrading methyl orange dye. The pure BFO showed a moderate photocatalytic activity; while BFO/γ-Fe2O3 nanocomposite showed enhanced activity. This could be probably due to the optimal band gap ratio between BFO and γ-Fe2O3 phases reduced the recombination of electron-hole pairs which aided in the enhancement of photocatalytic activity.

Effects of different radio-opacifying agents on physicochemical and biological properties of a novel root-end filling material

PubMed Central

Lü, Xiao-Ying; Liu, Gen-Di

2018-01-01

Background/Purpose Radio-opacity is an essential attribute of ideal root-end filling materials because it is important for clinicians to observe root canal filling and to facilitate the follow-up instructions. The novel root-end filling material (NRFM) has good cytocompatibility and physicochemical properties but low intrinsic radio-opacity value. To improve its radio-opacity value, three novel radio-opaque root-end filling materials (NRRFMs) were developed by adding barium sulphate (NRFM-Ba), bismuth trioxide (NRFM-Bi) and zirconium dioxide (NRFM-Zr) to NRFM, respectively. The purpose of this study was to identify the suitable radio-opacifier for NRFM through evaluating their physicochemical and biological properties, in comparison with NRFM and glass ionomer cement (GIC). Methods NRRFMs were characterized using X-ray diffraction (XRD) and Fourier transform infrared spectrophotometry (FTIR). Physicochemical properties including setting time, compressive strength, porosity, pH variation, solubility, washout resistance, contact angle and radiopacity were investigated. Cytocompatibility of both freshly mixed and set NRRFMs was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Alkaline phosphatase (ALP) activity assay and alizarin red staining were used to investigate the osteogenic differentiation potential of NRFM-Zr. Data were analyzed using two-way ANOVA (pH variation, solubility and ALP activity) and one-way ANOVA (for the other variables). Results (1) NRRFMs were primarily composed of hydroxyapatite, calcium carboxylate salt and the corresponding radio-opacity agents (barium sulphate, bismuth trioxide or zirconium dioxide). (2) Besides similar physicochemical properties in terms of setting time, pH variation, solubility, washout resistance and contact angle to NRFM, NRFM-Bi and NRFM-Zr exhibited lower porosity and greater compressive strength after being set for 7 days and their radio-opacity were greater than the 3 mm aluminium thickness specified in ISO 6876 (2001). (3) MTT assay revealed that freshly mixed and set NRFM-Zr presented better cell viability than NRFM-Ba and NRFM-Bi at 24 hours and 48 hours (P<0.05). (4) NRFM-Zr significantly enhanced ALP activity and calcium formation of human osteoblast-like Saos-2 cells when compared with negative group and GIC (P<0.05). Conclusion NRFM-Zr presents desirable physicochemical and biological properties, thus zirconium dioxide may be a suitable radio-opacifier for NRFM. PMID:29420559

Effects of different radio-opacifying agents on physicochemical and biological properties of a novel root-end filling material.

PubMed

Chen, Yao-Zhong; Lü, Xiao-Ying; Liu, Gen-Di

2018-01-01

Radio-opacity is an essential attribute of ideal root-end filling materials because it is important for clinicians to observe root canal filling and to facilitate the follow-up instructions. The novel root-end filling material (NRFM) has good cytocompatibility and physicochemical properties but low intrinsic radio-opacity value. To improve its radio-opacity value, three novel radio-opaque root-end filling materials (NRRFMs) were developed by adding barium sulphate (NRFM-Ba), bismuth trioxide (NRFM-Bi) and zirconium dioxide (NRFM-Zr) to NRFM, respectively. The purpose of this study was to identify the suitable radio-opacifier for NRFM through evaluating their physicochemical and biological properties, in comparison with NRFM and glass ionomer cement (GIC). NRRFMs were characterized using X-ray diffraction (XRD) and Fourier transform infrared spectrophotometry (FTIR). Physicochemical properties including setting time, compressive strength, porosity, pH variation, solubility, washout resistance, contact angle and radiopacity were investigated. Cytocompatibility of both freshly mixed and set NRRFMs was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Alkaline phosphatase (ALP) activity assay and alizarin red staining were used to investigate the osteogenic differentiation potential of NRFM-Zr. Data were analyzed using two-way ANOVA (pH variation, solubility and ALP activity) and one-way ANOVA (for the other variables). (1) NRRFMs were primarily composed of hydroxyapatite, calcium carboxylate salt and the corresponding radio-opacity agents (barium sulphate, bismuth trioxide or zirconium dioxide). (2) Besides similar physicochemical properties in terms of setting time, pH variation, solubility, washout resistance and contact angle to NRFM, NRFM-Bi and NRFM-Zr exhibited lower porosity and greater compressive strength after being set for 7 days and their radio-opacity were greater than the 3 mm aluminium thickness specified in ISO 6876 (2001). (3) MTT assay revealed that freshly mixed and set NRFM-Zr presented better cell viability than NRFM-Ba and NRFM-Bi at 24 hours and 48 hours (P<0.05). (4) NRFM-Zr significantly enhanced ALP activity and calcium formation of human osteoblast-like Saos-2 cells when compared with negative group and GIC (P<0.05). NRFM-Zr presents desirable physicochemical and biological properties, thus zirconium dioxide may be a suitable radio-opacifier for NRFM.

Synthesis, photoelectrochemical properties and solar light-induced photocatalytic activity of bismuth ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Pattnaik, Sambhu Prasad; Behera, Arjun; Martha, Satyabadi; Acharya, Rashmi; Parida, Kulamani

2018-01-01

Bismuth ferrite (BFO) nanoparticles prepared by solid state reaction route were characterized by various characterization techniques such as XRD, FESEM, HRTEM, UV-Vis DRS, PL etc., and their photocatalytic activities were evaluated by decolorization of aqueous solution of Congo red (CR) under solar light. The photocatalytic activity of BFO was increased by increasing the preparation temperature from 350 to 500 °C and then decreased with rise in temperature. The results of electrochemical measurements such as linear sweep voltammetry (LSV), electrochemical impedence (EIS), and Mott-Schottky analysis of BFO nanoparticles corroborated the findings of their photocatalytic activity. The enhanced photocatalytic response of the sample prepared at 500 °C is attributed to its smallest band gap, minimum crystallite size (30 nm), efficient separation, and lowest possible recombination of photo-generated charge carriers. The effects of amount of nano-BFO, irradiation time, initial CR concentration, and BFO calcination temperature on the decolorization of CR were examined. It was observed that 1 g/L nano-BFO calcined at 500 °C can decolorize up to 77% a 10-ppm CR dye solution under solar irradiation for 60 min. The studies included scavenger tests for identification of reactive species and a possible mechanism of dye decolorization.

Analyses of heavy metals in mineral trioxide aggregate and Portland cement.

PubMed

Schembri, Matthew; Peplow, George; Camilleri, Josette

2010-07-01

Portland cement is used in the construction industry as a binder in concrete. It is manufactured from chalk, limestone, and clay, which are clinkered at very high temperatures and ground with gypsum to form Portland cement. The raw materials and the manufacturing process can result in the inclusion of heavy metals in Portland cement. Portland cement with a four to one addition of bismuth oxide is marketed as mineral trioxide aggregate (MTA), which is used mainly as a dental material. Heavy metal inclusion can be of concern because MTA is in contact with hard and soft tissues. Measurements of arsenic, lead, and chromium in hydrated gray and white Portland cement, ProRoot MTA, and MTA Angelus were conducted with graphite furnace atomic absorption spectrophotometry after acid digestion on the hydrated material. The leaching of the metal ions from the solid material in water and simulated body fluid (SBF) was also determined. All cement types showed high relative values of leached chromium compared with arsenic and lead in both the total metal content and leached species. The gray Portland cement showed the highest total amount of metal. The white Portland and both MTAs had lower values for all the leached metal ions. Both MTAs released more arsenic than the amount specified in ISO 9917-1 (2007). Portland cements and MTAs showed evidence of heavy metals in the acid-soluble form as well as leaching in deionized water and SBF. MTA contained levels of arsenic higher than the safe limit specified by the ISO 9917-1 (2007). Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The chemical constitution and biocompatibility of accelerated Portland cement for endodontic use.

PubMed

Camilleri, J; Montesin, F E; Di Silvio, L; Pitt Ford, T R

2005-11-01

To evaluate the biocompatibility of mineral trioxide aggregate and accelerated Portland cement and their eluants by assessing cell metabolic function and proliferation. The chemical constitution of grey and white Portland cement, grey and white mineral trioxide aggregate (MTA) and accelerated Portland cement produced by excluding gypsum from the manufacturing process (Aalborg White) was determined using both energy dispersive analysis with X-ray and X-ray diffraction analysis. Biocompatibility of the materials was assessed using a direct test method where cell proliferation was measured quantitatively using Alamar Blue dye and an indirect test method where cells were grown on material elutions and cell proliferation was assessed using methyltetrazolium assay as recommended by the International standard guidelines, ISO 10993-Part 5 for in vitro testing. The chemical constitution of all the materials tested was similar. Indirect studies of the eluants showed an increase in cell activity after 24 h compared with the control in culture medium (P<0.05). Direct cell contact with the cements resulted in a fall in cell viability for all time points studied (P<0.001). Biocompatibility testing of the cement eluants showed the presence of no toxic leachables from the grey or white MTA, and that the addition of bismuth oxide to the accelerated Portland cement did not interfere with biocompatibility. The new accelerated Portland cement showed similar results. Cell growth was poor when seeded in direct contact with the test cements. However, the elution made up of calcium hydroxide produced during the hydration reaction was shown to induce cell proliferation.

Development of highly sensitive electrochemical genosensor based on multiwalled carbon nanotubes-chitosan-bismuth and lead sulfide nanoparticles for the detection of pathogenic Aeromonas.

PubMed

Fernandes, António Maximiano; Abdalhai, Mandour H; Ji, Jian; Xi, Bing-Wen; Xie, Jun; Sun, Jiadi; Noeline, Rasoamandrary; Lee, Byong H; Sun, Xiulan

2015-01-15

In this paper, we reported the construction of new high sensitive electrochemical genosensor based on multiwalled carbon nanotubes-chitosan-bismuth complex (MWCNT-Chi-Bi) and lead sulfide nanoparticles for the detection of pathogenic Aeromonas. Lead sulfide nanoparticles capped with 5'-(NH2) oligonucleotides thought amide bond was used as signalizing probe DNA (sz-DNA) and thiol-modified oligonucleotides sequence was used as fixing probe DNA (fDNA). The two probes hybridize with target Aeromonas DNA (tDNA) sequence (fDNA-tDNA-szDNA). The signal of hybridization is detected by differential pulse voltammetry (DPV) after electrodeposition of released lead nanoparticles (PbS) from sz-DNA on the surface of glass carbon electrode decorated with MWCNT-Chi-Bi, which improves the deposition and traducing electrical signal. The optimization of incubation time, hybridization temperature, deposition potential, deposition time and the specificity of the probes were investigated. Our results showed the highest sensibility to detect the target gene when compared with related biosensors and polymerase chain reaction (PCR). The detection limit for this biosensor was 1.0×10(-14) M. We could detect lower than 10(2) CFU mL(-1) of Aeromonas in spiked tap water. This method is rapid and sensitive for the detection of pathogenic bacteria and would become a potential application in biomedical diagnosis, food safety and environmental monitoring. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis of belt-like BiOBr hierarchical nanostructure with high photocatalytic performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Haiping; Liu, Jingyi; Hu, Tingxia

2016-05-15

Highlights: • BiOBr hierarchical nanobelts (NBs) were solvothermally prepared. • NBs show higher specific surface area and photoabsorption than BiOBr nanosheets. • NBs exhibit higher photoactivity than the nanosheets. - Abstract: One-dimensional (1D) bismuth oxyhalide (BiOX) hierarchical nanostructures are always difficult to prepare. Herein, we report, for the first time, a simple synthesis of BiOBr nanobelts (NBs) via a facile solvothermal route, using bismuth subsalicylate as the template and bismuth source. The BiOBr nanobelts are composed of irregular single crystal nanoparticles with highly exposed (0 1 0) facets. Compared with the BiOBr nanosheets (NSs) with dominant exposed (0 0 1)more » facets, they exhibit higher photocatalytic activity toward degradation of Rhodamine B and Methylene Blue under visible light irradiation. The higher photocatalytic performance of BiOBr NBs arises from their larger specific surface area and higher photoabsorption capability. This study provides a simple route for synthesis of belt-like Bi-based hierarchical nanostructures.« less

Small angle X-ray scattering analysis of the effect of cold compaction of Al/MoO3 thermite composites.

PubMed

Hammons, Joshua A; Wang, Wei; Ilavsky, Jan; Pantoya, Michelle L; Weeks, Brandon L; Vaughn, Mark W

2008-01-07

Nanothermites composed of aluminum and molybdenum trioxide (MoO(3)) have a high energy density and are attractive energetic materials. To enhance the surface contact between the spherical Al nanoparticles and the sheet-like MoO(3) particles, the mixture can be cold-pressed into a pelleted composite. However, it was found that the burn rate of the pellets decreased as the density of the pellets increased, contrary to expectation. Ultra-small angle X-ray scattering (USAXS) data and scanning electron microscopy (SEM) were used to elucidate the internal structure of the Al nanoparticles, and nanoparticle aggregate in the composite. Results from both SEM imaging and USAXS analysis indicate that as the density of the pellet increased, a fraction of the Al nanoparticles are compressed into sintered aggregates. The sintered Al nanoparticles lost contrast after forming the larger aggregates and no longer scattered X-rays as individual particles. The sintered aggregates hinder the burn rate, since the Al nanoparticles that make them up can no longer diffuse freely as individual particles during combustion. Results suggest a qualitative relationship for the probability that nanoparticles will sinter, based on the particle sizes and the initial structure of their respective agglomerates, as characterized by the mass fractal dimension.

The use of mineral trioxide aggregate in endodontics.

PubMed

Casella, G; Ferlito, S

2006-03-01

Mineral trioxide aggregate (MTA), composed mainly of tricalcic silicate, tricalcic alluminate, bismuth oxide, is a particular endodontic cement. It is made of hydrophilic fine particles that harden in the presence of dampness or blood. It is biocompatible, radiopaque and it is harder to infiltrate, compared to classic materials for root filling such as amalgam, cements, Super-EBA, and IRM. and SEM studies of sections and copies in resin of root neoapices filled with amalgam, IRM, Super-EBA and MTA, as well as tests of microinfiltration have shown that MTA has excellent sealing capacities. It requires a working time of about 5 min and a hardening time that varies from 2 h and 45 min to 4 h according to the density of the air entrapped during mixing and the dampness of the receiving site. The long hardening time reduces internal tensions and the incidence of marginal infiltration, but it forces to definitively fill the tooth in the following sitting, with an interval of at least 3 days from the MTA application. Clinical experience shows how MTA is a material of choice in cases not only of endodontic surgery, apicectomy and retrograde filling but also in the sealing filling of perforations of the pulp chamber and of the root, stripping, internal reabsorptions, readaptations, lacerations, and apical transports. It has been used with success also in direct cappings and in apexifications instead of calcium hydroxide, leading to quicker therapies and more predictable The authors outline the operative phases of the different treatments proposed, make a survey of the most important studies published so far and hope that a new sealing cement with more reduced hardening times will soon be available.

Silver-doped manganese dioxide and trioxide nanoparticles inhibit both gram positive and gram negative pathogenic bacteria.

PubMed

Kunkalekar, R K; Prabhu, M S; Naik, M M; Salker, A V

2014-01-01

Palladium, ruthenium and silver-doped MnO2 and silver doped Mn2O3 nanoparticles were synthesized by simple co-precipitation technique. SEM-TEM analysis revealed the nano-size of these synthesized samples. XPS data illustrates that Mn is present in 4+ and 3+ oxidation states in MnO2 and Mn2O3 respectively. Thermal analysis gave significant evidence for the phase changes with increasing temperature. Antibacterial activity of these synthesized nanoparticles on three Gram positive bacterial cultures (Staphylococcus aureus ATCC 6538, Streptococcus epidermis ATCC 12228, Bacillus subtilis ATCC 6633) and three Gram negative cultures (Escherichia coli ATCC 8739, Salmonella abony NCTC 6017 and Klebsiella pneumoniae ATCC 1003) was investigated using a disc diffusion method and live/dead assay. Only Ag-doped MnO2 and Ag-doped Mn2O3 nanoparticles showed antibacterial property against all six-test bacteria but Ag-doped MnO2 was found to be more effective than Ag-doped Mn2O3. Copyright © 2013 Elsevier B.V. All rights reserved.

Optical and structural properties of Bi-based nanoparticles prepared via pulsed Nd:YAG laser ablation in organic liquids

NASA Astrophysics Data System (ADS)

Dadashi, S.; Poursalehi, R.; Delavari, H.

2018-06-01

Colloidal Bi/Bi2O3 and single phase Bi nanoparticles were synthesized by pulsed Nd:YAG laser ablation of metallic bismuth target in different organic liquids. In this research, the structural characteristic, optical properties, and colloidal stability of Bi and Bi/Bi2O3 nanoparticles have been studied. Furthermore, the mechanism of nanoparticles formation in liquid media by laser ablation of Bi-based nanoparticles was proposed in different liquid environments based on their chemical nature. X-ray diffraction, scanning electron microscopy and optical extinction spectroscopy indicate the formation of pure Bi and Bi/Bi2O3 nanoparticles with mean size of 32, 43 and 54 nm in methanol, ethanol, and EMK, respectively, which indicate a mixture of different phases including rhombohedra crystal structure of Bi, monoclinic α-Bi2O3, and tetragonal β-Bi2O3. Finally, this research demonstrates the effect of the surrounding environment on characteristic properties of nanoparticles and clarifies the size, structural characteristics, and optical properties of the synthesized nanoparticles.

Green synthesis of BiVO4 nanorods via aqueous extracts of Callistemon viminalis

NASA Astrophysics Data System (ADS)

Mohamed, H. E. A.; Sone, B. T.; Fuku, X. G.; Dhlamini, M. S.; Maaza, M.

2018-05-01

Nowadays, the development of efficient green chemistry methods for synthesis of metal oxides nanoparticles has become a major focus of researchers. These methods are being investigated in order to find an eco-friendly technique for production of well-characterized nanoparticles. In this contribution we report for the first time, the synthesis and structural characterization of n-type Bismuth vanadate (BiVO4) nanoparticles using aqueous extracts of Callistemon viminalis as a chelating agent. To ascertain the formation of BiVO4, X-Ray diffraction analysis (XRD), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED), Electron Dispersion X-ray Spectroscopy (EDS), Fourier Transform Infra-red Spectroscopy (FTIR), and Photoluminescence spectroscopy (PL) were carried out.

In Situ Activation of 3D Porous Bi/Carbon Architectures: Toward High-Energy and Stable Nickel-Bismuth Batteries.

PubMed

Zeng, Yinxiang; Lin, Ziqi; Wang, Zifan; Wu, Mingmei; Tong, Yexiang; Lu, Xihong

2018-05-01

To achieve high-energy and stable aqueous rechargeable batteries, state-of-the art of anode materials are needed. Bismuth (Bi) has recently emerged as an attractive anode material due to its highly reversible redox reaction and suitable negative operating working window. However, the capacity and durability of currently reported Bi anodes are still far from satisfactory. Here, an in situ activation strategy is reported to prepare a 3D porous high-density Bi nanoparticles/carbon architecture (P-Bi-C) as an efficient anode for nickel-bismuth batteries. Taking advantages of the fast channels for charge transfer and ion diffusion, enhanced wettability, and accessible surface area, the highly loaded P-Bi-C electrode delivers a remarkable capacity of 2.11 mA h cm -2 as well as high rate capability (1.19 mA h cm -2 at 120 mA cm -2 ). To highlight, a robust aqueous rechargeable Ni//Bi battery based on the P-Bi-C anode is first constructed, achieving decent capacity (141 mA h g -1 ), impressive durability (94% capacity retention after 5000 cycles), and admirable energy density (16.9 mW h cm -3 ). This work paves the way for designing superfast nickel-bismuth batteries with high energy and long-life and may inspire new development for aqueous rechargeable batteries. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reinforced fluropolymer nanocomposites with high-temperature superconducting Bi2Sr2CaCu2Oy

NASA Astrophysics Data System (ADS)

Jayasree, T. K.

2014-10-01

Bismuth Strontium Calcium Copper Oxide (Bi2Sr2CaCu2Oy)/Polyvinylidene fluoride (PVDF) nanocomposite was prepared and their thermal properties were analyzed. The composite consists of the polyvinylidene fluoride (PVDF) as an insulating polymer matrix, and homogenously distributed Bismuth strontium calcium copperoxide (2212) nanoparticles. SEM data shows flaky grains of the superconductor coated and linked by polymer. Differential scanning calorimetry (DSC) results indicated that the melting point was not affected significantly by the addition of BSCCO. However, the addition of superconducting ceramic resulted in an extra melting peak at a lower temperature (145°C). Thermogravimetric analysis of the samples shows that the onset decomposition temperature of the PVDF matrix was decreased by the addition of SC filler.

Effect of Pt Nanoparticles on the Optical Gas Sensing Properties of WO3 Thin Films

PubMed Central

Qadri, Muhammad U.; Diaz Diaz, Alex Fabian; Cittadini, Michaela; Martucci, Alessandro; Pujol, Maria Cinta; Ferré-Borrull, Josep; Llobet, Eduard; Aguiló, Magdalena; Díaz, Francesc

2014-01-01

Thin films of tungsten trioxide were deposited on quartz substrates by RF magnetron sputtering. Different annealing temperatures in the range from 423 to 973 K were used under ambient atmosphere. The influence of the annealing temperature on the structure and optical properties of the resulting WO3 thin films were studied. The surface morphology of the films is composed of grains with an average size near 70 nm for the films annealed between 773 and 973 K. Some of the WO3 thin films were also coated with Pt nanoparticles of about 45 nm in size. Spectrometric measurements of transmittance were carried out for both types of WO3 samples in the wavelength range from 200–900 nm, to determine the effect of the exposure to two different gases namely H2 and CO. Films showed fast response and recovery times, in the range of few seconds. The addition of Pt nanoparticles enables reducing the operation temperature to room temperature. PMID:24977386

Two basic bismuth nitrates: [Bi6O6(OH)2](NO3)4 · 2H2O with superior photodegradation activity for rhodamine B and [Bi6O5(OH)3](NO3)5 · 3H2O with ultrahigh adsorption capacity for methyl orange

NASA Astrophysics Data System (ADS)

Pang, Jiawei; Han, Qiaofeng; Liu, Weiqi; Shen, Zichen; Wang, Xin; Zhu, Junwu

2017-11-01

A novel basic bismuth nitrate, [Bi6O6(OH)2](NO3)4·2H2O (denoted as BiON-4N), was easily obtained at room temperature in the existence of 2-methoxyethanol (CH3OCH2CH2OH; 2ME) with a pH value ranging from 4.5 to 7.0. The morphology of BiON-4N could be easily tailored by changing the variety and amount of bases like urea, hexamethylenetetramine (HMTA), NaOH and NH3·H2O. When the solution pH was decreased lower than 4.5, another basic bismuth nitrate, [Bi6O5(OH)3](NO3)5·3H2O (denoted as BiON-5N), could be synthesized. Among those, BiON-4N nanoparticles obtained with 40 mmol of HMTA exhibited superior photocatalytic activity for rhodamine B (RhB) degradation with an efficiency of 100% within 4 min of UV light irradiation, which was much higher than that of commercial TiO2 (P25). The excellent photocatalytic performance of BiON-4N was mainly attributed to higher surface area (13.1 m2 g-1) in comparison with other basic bismuth nitrates. Furthermore, the as-prepared BiON-5N revealed excellent adsorption performance for the anions like methyl orange (MO) and K2Cr2O7, and especially for MO, the maximum adsorption capacity arrived up to 730 mg g-1, which should be relevant to highly positively charged surface. This work provides a new strategy for developing bismuth-based nanomaterials in the big bismuth family as potential photocatalyst and adsorbent for the removal of dyes and contaminants.

Metal oxide films on metal

DOEpatents

Wu, Xin D.; Tiwari, Prabhat

1995-01-01

A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.

PREPARATION OF URANIUM TRIOXIDE

DOEpatents

Buckingham, J.S.

1959-09-01

The production of uranium trioxide from aqueous solutions of uranyl nitrate is discussed. The uranium trioxide is produced by adding sulfur or a sulfur-containing compound, such as thiourea, sulfamic acid, sulfuric acid, and ammonium sulfate, to the uranyl solution in an amount of about 0.5% by weight of the uranyl nitrate hexahydrate, evaporating the solution to dryness, and calcining the dry residue. The trioxide obtained by this method furnished a dioxide with a considerably higher reactivity with hydrogen fluoride than a trioxide prepared without the sulfur additive.

Effect of Yb substitution on room temperature magnetic and dielectric properties of bismuth ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Remya, K. P.; Amirthapandian, S.; Manivel Raja, M.; Viswanathan, C.; Ponpandian, N.

2016-10-01

Effect of the Yb dopant on the structural, magnetic, and electrical properties of the multiferroic BiFeO3 have been studied. The structural properties of sol-gel derived Bi1-xYbxFeO3 (x = 0.0, 0.1, and 0.2) nanoparticles reveal the formation of a rhombohedrally distorted perovskite in XRD and a reduction in the average grain size have been observed with an increase in the Yb concentration. Microstructural studies exhibited the formation of sphere like morphology with decreasing particle size with increase in the dopant concentration. The effective doping also resulted in larger magnetization as well as coercivity with the maximum of 257 Oe and 1.76 emu/g in the Bi0.8Yb0.2FeO3 nanoparticles. Ferroelectric as well as dielectric properties of the nanoparticles were also improved on doping. The best results were obtained for the BiFeO3 nanoparticles having Yb concentration x = 0.2.

Templated assembly of BiFeO3 nanocrystals into 3D mesoporous networks for catalytic applications

NASA Astrophysics Data System (ADS)

Papadas, I. T.; Subrahmanyam, K. S.; Kanatzidis, M. G.; Armatas, G. S.

2015-03-01

The self-assembly of uniform nanocrystals into large porous architectures is currently of immense interest for nanochemistry and nanotechnology. These materials combine the respective advantages of discrete nanoparticles and mesoporous structures. In this article, we demonstrate a facile nanoparticle templating process to synthesize a three-dimensional mesoporous BiFeO3 material. This approach involves the polymer-assisted aggregating assembly of 3-aminopropanoic acid-stabilized bismuth ferrite (BiFeO3) nanocrystals followed by thermal decomposition of the surfactant. The resulting material consists of a network of tightly connected BiFeO3 nanoparticles (~6-7 nm in diameter) and has a moderately high surface area (62 m2 g-1) and uniform pores (ca. 6.3 nm). As a result of the unique mesostructure, the porous assemblies of BiFeO3 nanoparticles show an excellent catalytic activity and chemical stability for the reduction of p-nitrophenol to p-aminophenol with NaBH4.The self-assembly of uniform nanocrystals into large porous architectures is currently of immense interest for nanochemistry and nanotechnology. These materials combine the respective advantages of discrete nanoparticles and mesoporous structures. In this article, we demonstrate a facile nanoparticle templating process to synthesize a three-dimensional mesoporous BiFeO3 material. This approach involves the polymer-assisted aggregating assembly of 3-aminopropanoic acid-stabilized bismuth ferrite (BiFeO3) nanocrystals followed by thermal decomposition of the surfactant. The resulting material consists of a network of tightly connected BiFeO3 nanoparticles (~6-7 nm in diameter) and has a moderately high surface area (62 m2 g-1) and uniform pores (ca. 6.3 nm). As a result of the unique mesostructure, the porous assemblies of BiFeO3 nanoparticles show an excellent catalytic activity and chemical stability for the reduction of p-nitrophenol to p-aminophenol with NaBH4. Electronic supplementary information (ESI) available: IR spectra and TG profiles of as-made BiFeO3 NPs and MBFA samples, TEM images of 3-APA-capped BiFeO3 NPs, EDS spectrum of MBFAs, N2 adsorption-desorption isotherms of randomly aggregated BiFeO3 NPs and catalytic data for 4-NP reduction by MBFAs and other nanostructured catalysts. See DOI: 10.1039/c5nr00185d

Influence of light and oxygen on the color stability of five calcium silicate-based materials.

PubMed

Vallés, Marta; Mercadé, Montse; Duran-Sindreu, Fernando; Bourdelande, Jose L; Roig, Miguel

2013-04-01

Difficult handling, long setting time, and potential discoloration are important drawbacks of white mineral trioxide aggregate (WMTA). The development of Biodentine, a recently developed calcium silicate-based material (CSM), has overcome some of these shortcomings; however, there are no available data on its color stability. A previous study showed that WMTA discolors under light irradiation in an oxygen-free environment. The present study evaluated the influence of light irradiation and oxygen on the color stability of 5 CSMs. Fifteen samples of 5 CSMs (ProRoot WMTA, Angelus WMTA, White Portland Cement [PC], PC with bismuth oxide, and Biodentine) were divided into 5 groups. Each group was exposed to different oxygen and light conditions. A spectrophotometer was used to determine the color of each specimen at 0, 120 seconds, and 5 days. Data were analyzed by using analysis of variance and Tukey honestly significant difference test. The materials PC with bismuth oxide, Angelus WMTA, and ProRoot WMTA showed dark discoloration after light irradiation in an oxygen-free environment, which was statistically significantly different from Biodentine and PC. In groups that were exposed to no light irradiation or to an oxygen atmosphere, all materials showed color stability over time, and no significant differences were observed among them. PC and Biodentine maintained color stability in all conditions over time and showed no significant differences. The combination of light and anaerobic conditions (similar to those in clinical situations) results in differences in color of the tested CSMs during a period of 5 days, of which Biodentine and PC demonstrated color stability. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Characterization of bismuth selenide (Bi2Se3) thin films obtained by evaporating the hydrothermally synthesised nano-particles

NASA Astrophysics Data System (ADS)

Indirajith, R.; Rajalakshmi, M.; Gopalakrishnan, R.; Ramamurthi, K.

2016-03-01

Bismuth selenide (Bi2Se3) was synthesized by hydrothermal method at 200 °C and confirmed by powder X-ray diffraction (XRD) studies. The synthesized material was utilized to deposit bismuth selenide thin films at various substrate temperatures (Room Temperature-RT, 150 °C, 250 °C, 350 °C and 450 °C) by electron beam evaporation technique. XRD study confirmed the polycrystalline nature of the deposited Bi2Se3films. Optical transmittance spectra showed that the deposited (at RT) films acquire relatively high average transmittance of 60%in near infrared region (1500-2500 nm). An indirect allowed optical band gap calculated from the absorption edge for the deposited films is ranging from 0.62 to 0.8 eV. Scanning electron and atomic force microscopy analyses reveal the formation of nano-scale sized particles on the surface and that the nature of surface microstructures is influenced by the substrate temperature. Hall measurements showed improved electrical properties, for the films deposited at 350 °C which possess 2.8 times the mobility and 0.9 times the resistivity of the films deposited at RT.

Arsenic trioxide-mediated growth inhibition in gallbladder carcinoma cells via down-regulation of Cyclin D1 transcription mediated by Sp1 transcription factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ai, Zhilong; Lu, Weiqi; Ton, Saixiong

2007-08-31

Gallbladder carcinoma (GBC), an aggressive and mostly lethal malignancy, is known to be resistant to a number of drug stimuli. Here, we demonstrated that arsenic trioxide inhibited the proliferation of gallbladder carcinoma in vivo and in vitro as well as the transcription of cell cycle-related protein Cyclin D1. And, Cyclin D1 overexpression inhibited the negative role of arsenic trioxide in cell cycle progression. We further explored the mechanisms by which arsenic trioxide affected Cyclin D1 transcription and found that the Sp1 transcription factor was down-regulated by arsenic trioxide, with a corresponding decrease in Cyclin D1 promoter activity. Taken together, thesemore » results suggested that arsenic trioxide inhibited gallbladder carcinoma cell proliferation via down-regulation of Cyclin D1 transcription in a Sp1-dependent manner, which provided a new mechanism of arsenic trioxide-involved cell proliferation and may have important therapeutic implications in gallbladder carcinoma patients.« less

Method for removing sulfur oxide from waste gases and recovering elemental sulfur

DOEpatents

Moore, Raymond H.

1977-01-01

A continuous catalytic fused salt extraction process is described for removing sulfur oxides from gaseous streams. The gaseous stream is contacted with a molten potassium sulfate salt mixture having a dissolved catalyst to oxidize sulfur dioxide to sulfur trioxide and molten potassium normal sulfate to solvate the sulfur trioxide to remove the sulfur trioxide from the gaseous stream. A portion of the sulfur trioxide loaded salt mixture is then dissociated to produce sulfur trioxide gas and thereby regenerate potassium normal sulfate. The evolved sulfur trioxide is reacted with hydrogen sulfide as in a Claus reactor to produce elemental sulfur. The process may be advantageously used to clean waste stack gas from industrial plants, such as copper smelters, where a supply of hydrogen sulfide is readily available.

Arsenic Trioxide Injection

MedlinePlus

Arsenic trioxide is used to treat acute promyelocytic leukemia (APL; a type of cancer in which there ... worsened following treatment with other types of chemotherapy. Arsenic trioxide is in a class of medications called ...

Organic bistable memory devices based on MoO3 nanoparticle embedded Alq3 structures.

PubMed

Abhijith, T; Kumar, T V Arun; Reddy, V S

2017-03-03

Organic bistable memory devices were fabricated by embedding a thin layer of molybdenum trioxide (MoO 3 ) between two tris-(8-hydroxyquinoline)aluminum (Alq 3 ) layers. The device exhibited excellent switching characteristics with an ON/OFF current ratio of 1.15 × 10 3 at a read voltage of 1 V. The device showed repeatable write-erase capability and good stability in both the conductance states. These conductance states are non-volatile in nature and can be obtained by applying appropriate voltage pulses. The effect of MoO 3 layer thickness and its location in the Alq 3 matrix on characteristics of the memory device was investigated. The field emission scanning electron microscopy (FE-SEM) images of the MoO 3 layer revealed the presence of isolated nanoparticles. Based on the experimental results, a mechanism has been proposed for explaining the conductance switching of fabricated devices.

Organic bistable memory devices based on MoO3 nanoparticle embedded Alq3 structures

NASA Astrophysics Data System (ADS)

Abhijith, T.; Kumar, T. V. Arun; Reddy, V. S.

2017-03-01

Organic bistable memory devices were fabricated by embedding a thin layer of molybdenum trioxide (MoO3) between two tris-(8-hydroxyquinoline)aluminum (Alq3) layers. The device exhibited excellent switching characteristics with an ON/OFF current ratio of 1.15 × 103 at a read voltage of 1 V. The device showed repeatable write-erase capability and good stability in both the conductance states. These conductance states are non-volatile in nature and can be obtained by applying appropriate voltage pulses. The effect of MoO3 layer thickness and its location in the Alq3 matrix on characteristics of the memory device was investigated. The field emission scanning electron microscopy (FE-SEM) images of the MoO3 layer revealed the presence of isolated nanoparticles. Based on the experimental results, a mechanism has been proposed for explaining the conductance switching of fabricated devices.

Mineral Trioxide Aggregate and Portland Cement for Direct Pulp Capping in Dog: A Histopathological Evaluation

PubMed Central

Bidar, Maryam; Naghavi, Neda; Mohtasham, Nooshin; Sheik-Nezami, Mahshid; Fallahrastegar, Amir; Afkhami, Farzaneh; Attaran Mashhadi, Negin; Nargesi, Iman

2014-01-01

Background and aims. Mineral trioxide aggregate and calcium hydroxide are considered the gold standard pulp-capping materials. Recently, Portland cement has been introduced with properties similar to those of mineral trioxide aggregate. Histopathological effects of direct pulp capping using mineral trioxide aggregate and Portland cements on dog dental pulp tissue were evaluated in the present study. Materials and methods. This histopatological study was carried out on 64 dog premolars. First, the pulp was exposed with a sterile bur. Then, the exposed pulp was capped with white or gray mineral trioxide aggregates and white or gray Portland cements in each quadrant and sealed with glass-ionomer. The specimens were evaluated under a light microscope after 6 months. Statistical analysis was carried out using Kruskal-Wallis test. Statistical significance was defined at α=5%. Results. There was no acute inflammation in any of the specimens. Chronic inflammation in white and gray mineral trioxide aggregates and white and gray Portland cements was reported to be 45.5%, 27.3%, 57.1% and 34.1%, respectively. Although the differences were not statistically significant, severe inflammation was observed mostly adjacent to white mineral trioxide aggregate. The largest extent of increased vascularization (45%) and the least increase in fibrous tissue were observed adjacent to white mineral trioxide aggregate, with no significant differences. In addition, the least calcified tissue formed adjacent to white mineral trioxide aggregate, although the difference was not significant. Conclusion. The materials used in this study were equally effective as pulp protection materials following direct pulp capping in dog teeth. PMID:25346831

Mineral trioxide aggregate: part 2 - a review of the material aspects.

PubMed

Malhotra, Neeraj; Agarwal, Antara; Mala, Kundabala

2013-03-01

The purpose of this two-part series is to review the composition, properties, and products of mineral trioxide aggregate (MTA) materials. PubMed and MedLine electronic databases were used to identify scientific papers from January 1991 to May 2010. Based on the selected inclusion criteria, citations were referenced from the scientific peer-reviewed dental literature. Mineral trioxide aggregate is a refined form of the parent compound, Portland cement (PC), and demonstrates a strong biocompatibility due to the high pH level and the material's ability to form hydroxyapatite. Mineral trioxide aggregate materials provide better microleakage protection than traditional endodontic materials as observed in findings from dye-leakage, fluid-filtration, protein-leakage, and bacterial penetration-leakage studies and has been recognized as a bioactive material. Various MTA commercial products are available, including gray mineral trioxide aggregate (GMTA), white mineral trioxide aggregate (WMTA), and mineral trioxide aggregate-Angelus (AMTA). Although these materials are indicated for various dental uses and applications, long-term in-vivo clinical studies are needed. Part 1 of this article highlighted and discussed the composition and characteristics of the material. Part 2 provides an overview of commercially available MTA materials.

Bismuth@US-tubes as a Potential Contrast Agent for X-ray Imaging Applications

PubMed Central

Rivera, Eladio J.; Tran, Lesa A.; Hernández-Rivera, Mayra; Yoon, Diana; Mikos, Antonios G.; Rusakova, Irene A.; Cheong, Benjamin Y.; Cabreira-Hansen, Maria da Graça; Willerson, James T.; Perin, Emerson C.; Wilson, Lon J.

2013-01-01

The encapsulation of bismuth as BiOCl/Bi2O3 within ultra-short (ca. 50 nm) single-walled carbon nanocapsules (US-tubes) has been achieved. The Bi@US-tubes have been characterized by high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Bi@US-tubes have been used for intracellular labeling of pig bone marrow-derived mesenchymal stem cells (MSCs) to show high X-ray contrast in computed tomography (CT) cellular imaging for the first time. The relatively high contrast is achieved with low bismuth loading (2.66% by weight) within the US-tubes and without compromising cell viability. X-ray CT imaging of Bi@US-tubes-labeled MSCs showed a nearly two-fold increase in contrast enhancement when compared to unlabeled MSCs in a 100 kV CT clinical scanner. The CT signal enhancement from the Bi@US-tubes is 500 times greater than polymer-coated Bi2S3 nanoparticles and several-fold that of any clinical iodinated contrast agent (CA) at the same concentration. Our findings suggest that the Bi@US-tubes can be used as a potential new class of X-ray CT agent for stem cell labeling and possibly in vivo tracking. PMID:24288589

Arsenic trioxide mediates HAPI microglia inflammatory response and subsequent neuron apoptosis through p38/JNK MAPK/STAT3 pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mao, Jiamin

Arsenic is a widely distributed toxic metalloid all over the world. Inorganic arsenic species are supposed to affect astrocytic functions and to cause neuron apoptosis in CNS. Microglias are the key cell type involved in innate immune responses in CNS, and microglia activation has been linked to inflammation and neurotoxicity. In this study, using ELISA, we showed that Arsenic trioxide up-regulated the expression and secretion of IL-1β in a dose-dependent manner and a time-dependent manner in cultured HAPI microglia cells. The secretion of IL-1β caused the apoptosis of SH-SY5Y. These pro-inflammatory responses were inhibited by the STAT3 blocker, AG490 andmore » P38/JNK MAPK blockers SB202190, SP600125. Further, Arsenic trioxide exposure could induce phosphorylation and activation of STAT3, and the translocation of STAT3 from the cytosol to the nucleus in this HAPI microglia cell line. Thus, the STAT3 signaling pathway can be activated after Arsenic trioxide treatment. However, P38/JNK MAPK blockers SB202190, SP600125 also obviously attenuated STAT3 activation and transnuclear transport induced by Arsenic trioxide. In concert with these results, we highlighted that the secretion of IL-1β and STAT3 activation induced by Arsenic trioxide can be mediated by elevation of P38/JNK MAPK in HAPI microglia cells and then induced the toxicity of neurons. - Highlights: • Arsenic trioxide exposure induced expression of IL-β in HAPI microglia. • Arsenic trioxide exposure induced activation of MAPK pathways in HAPI microglia. • Arsenic trioxide exposure induced activation of STAT3 pathways in HAPI microglia. • The expression of IL-β though P38/JNK MAPK/STAT3 pathways in HAPI microglia.« less

In Vitro Cytotoxicity of Nanoparticles in Mammalian Germline Stem Cells

PubMed Central

Braydich-Stolle, Laura; Hussain, Saber; Schlager, John J.; Hofmann, Marie-Claude

2010-01-01

Gametogenesis is a complex biological process that is particularly sensitive to environmental insults such as chemicals. Many chemicals have a negative impact on the germline, either by directly affecting the germ cells, or indirectly through their action on the somatic nursing cells. Ultimately, these effects can inhibit fertility, and they may have negative consequences for the development of the offspring. Recently, nanomaterials such as nanotubes, nanowires, fullerene derivatives (buckyballs), and quantum dots have received enormous national attention in the creation of new types of analytical tools for biotechnology and the life sciences. Despite the wide application of nanomaterials, there is a serious lack of information concerning their impact on human health and the environment. Thus, there are limited studies available on toxicity of nanoparticles for risk assessment of nanomaterials. The purpose of this study was to assess the suitability of a mouse spermatogonial stem cell line as a model to assess nanotoxicity in the male germline in vitro. The effects of different types of nanoparticles on these cells were evaluated by light microscopy, and by cell proliferation and standard cytotoxicity assays. Our results demonstrate a concentration-dependent toxicity for all types of particles tested, whereas the corresponding soluble salts had no significant effect. Silver nanoparticles were the most toxic while molybdenum trioxide (MoO3) nanoparticles were the least toxic. Our results suggest that this cell line provides a valuable model with which to assess the cytotoxicity of nanoparticles in the germ line in vitro. PMID:16014736

Novel bismuth tri-iodide nanostructures obtained by the hydrothermal method and electron beam irradiation

NASA Astrophysics Data System (ADS)

Aguiar, Ivana; Olivera, Alvaro; Mombrú, Maia; Bentos Pereira, Heinkel; Fornaro, Laura

2017-01-01

Bismuth tri-iodide is a layered compound semiconductor which has suitable properties as material for ionizing radiation detection devices. Monocrystals and polycrystalline thin films have been studied for this application, but only recently, the development of nanostructures of this compound has emerged as an interesting alternative for using such nanostructures in new types of radiation detectors or for including them in other applications. Considering this, we present in this work BiI3 nanoparticles successfully synthesized by the hydrothermal method, using a Teflon-lined stainless steel autoclave, at a temperature of 180 °C during 8-20 h, with BiCl3 and NaI as source materials. We characterized the nanoparticles by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron dispersive spectroscopy (EDS). We obtained small rounded or hexagonal particles (10-20 nm in size) and larger structures. The maximum orientation of the nanostructures is along the (0 0 l) family planes and occurs after 16 h of synthesis, which arises as the best condition for obtaining BiI3 oriented nanostructures. When a 100 kV TEM electron beam was converged on the larger structures, we obtained highly oriented BiI3 hexagonal and rod shaped nanostructures. We found that particles' shape does not depend on the synthesis time. In addition, results were compared with the ones obtained for nanoparticles synthesized from solution. The present work is an advance in the synthesis of BiI3 nanostructures by the hydrothermal method, and is also the first step on seeking the amenable control of morphology and size of such structures using electron beam irradiation. This last process may be particularly appropriate for producing nanostructures for future applications in new devices.

EFFECTS OF ARSENIC TRIOXIDE INHALATION EXPOSURE ON PULMONARY ANTIBACTERIAL DEFENSES IN MICE

EPA Science Inventory

The effects of single and multiple (5 and 20) 3 hr inhalation exposures to aerosols of arsenic trioxide on the pulmonary defense system of mice were investigated. Arsenic trioxide mist was generated from an aqueous solution and dried to produce particulate aerosols of 0.4 microme...

Improving Tribological Properties of Multialkylated Cyclopentanes under Simulated Space Environment: Two Feasible Approaches.

PubMed

Fan, Xiaoqiang; Wang, Liping; Li, Wen; Wan, Shanhong

2015-07-08

Space mechanisms require multialkylated cyclopentanes (MACs) more lubricious, more reliable, more durable, and better adaptive to harsh space environments. In this study, two kinds of additives were added into MACs for improving the tribological properties under simulated space environments: (a) solid nanoparticles (tungsten disulfide (WS2), tungsten trioxide (WO3), lanthanum oxide (La2O3), and lanthanum trifluoride (LaF3)) for steel/steel contacts; (b) liquid additives like zinc dialkyldithiophosphate (ZDDP) and molybdenum dialkyldithiocarbamate (MoDTC) for steel/steel and steel/diamond-like carbon (DLC) contacts. The results show that, under harsh simulated space environments, addition of the solid nanoparticles into MACs allows the wear to be reduced by up to one order magnitude, while liquid additives simultaneously reduce friction and wear by 80% and 93%, respectively. Friction mechanisms were proposed according to surface/interface analysis techniques, such as X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS). The role of solid nanoparticles in reducing friction and wear mainly depends on their surface enhancement effect, and the liquid additives are attributed to the formation of tribochemical reaction film derived from ZDDP and MoDTC on the sliding surfaces.

Arsenite-loaded nanoparticles inhibit the invasion and metastasis of a hepatocellular carcinoma: in vitro and in vivo study

NASA Astrophysics Data System (ADS)

Chi, Xiaoqin; Yin, Zhenyu; Jin, Jianbin; Li, Hui; Zhou, Jian; Zhao, Zhenghuan; Zhang, Sheng; Zhao, Wenxiu; Xie, Chengrong; Li, Jie; Feng, Min; Lin, Hongyu; Wang, Xiaomin; Gao, Jinhao

2017-11-01

Postoperative recurrence and metastasis are the major problems for the current treatment of hepatocellular carcinomas (HCC) in the clinic, including hepatectomy and liver transplantation. Here, we report that arsentic-loaded nanoparticles (ALNPs) are able to reduce the invasion of HCC cells in vitro, and, more importantly, can strongly suppress the invasion and metastasis of HCC in vivo without adverse side effects. Compared to free drug arsenic trioxide , ALNPs can deliver the drug into cancer cells more efficiently, destroy the structure of microtubules and reduce the aggregation of microfilaments in cell membranes more significantly. Furthermore, our results also reveal that tumor cells in murine blood were reduced remarkably after intravenous injection of ALNPs, indicating that this nano-drug may efficiently kill circulating tumor cells in vivo. In conclusion, our nano-drug ALNPs have great potential for the suppression of metastasis of HCC, which may open up a new avenue for the effective treatment of HCC without metastasis and recurrence.

Effect of addition of nano-hydroxyapatite on physico-chemical and antibiofilm properties of calcium silicate cements.

PubMed

Guerreiro-Tanomaru, Juliane Maria; Vázquez-García, Fernando Antonio; Bosso-Martelo, Roberta; Bernardi, Maria Inês Basso; Faria, Gisele; Tanomaru, Mario

2016-01-01

Mineral Trioxide Aggregate (MTA) is a calcium silicate cement composed of Portland cement (PC) and bismuth oxide. Hydroxyapatite has been incorporated to enhance mechanical and biological properties of dental materials. This study evaluated physicochemical and mechanical properties and antibiofilm activity of MTA and PC associated with zirconium oxide (ZrO2) and hydroxyapatite nanoparticles (HAn). White MTA (Angelus, Brazil); PC (70%)+ZrO2 (30%); PC (60%)+ZrO2 (30%)+HAn (10%); PC (50%)+ZrO2 (30%)+HAn (20%) were evaluated. The pH was assessed by a digital pH-meter and solubility by mass loss. Setting time was evaluated by using Gilmore needles. Compressive strength was analyzed by mechanical test. Samples were radiographed alongside an aluminum step wedge to evaluate radiopacity. For the antibiofilm evaluation, materials were placed in direct contact with E. faecalis biofilm induced on dentine blocks. The number of colony-forming units (CFU mL-1) in the remaining biolfilm was evaluated. The results were submitted to ANOVA and the Tukey test, with 5% significance. There was no difference in pH levels of PC+ZrO2, PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p>0.05) and these cements presented higher pH levels than MTA (p<0.05). The highest solubility was observed in PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p<0.05). MTA had the shortest initial setting time (p<0.05). All the materials showed radiopacity higher than 3 mmAl. PC+ZrO2 and MTA had the highest compressive strength (p<0.05). Materials did not completely neutralize the bacterial biofilm, but the association with HAn provided greater bacterial reduction than MTA and PC+ZrO2 (p<0.05) after the post-manipulation period of 2 days. The addition of HAn to PC associated with ZrO2 harmed the compressive strength and solubility. On the other hand, HAn did not change the pH and the initial setting time, but improved the radiopacity (HAn 10%), the final setting time and the E. faecalis antibiofilm activity of the cement.

Topological insulator bismuth selenide as a theranostic platform for simultaneous cancer imaging and therapy.

PubMed

Li, Juan; Jiang, Fei; Yang, Bo; Song, Xiao-Rong; Liu, Yan; Yang, Huang-Hao; Cao, Dai-Rong; Shi, Wen-Rong; Chen, Guo-Nan

2013-01-01

Employing theranostic nanoparticles, which combine both therapeutic and diagnostic capabilities in one dose, has promise to propel the biomedical field toward personalized medicine. Here we investigate the theranostic properties of topological insulator bismuth selenide (Bi2Se3) in in vivo and in vitro system for the first time. We show that Bi2Se3 nanoplates can absorb near-infrared (NIR) laser light and effectively convert laser energy into heat. Such photothermal conversion property may be due to the unique physical properties of topological insulators. Furthermore, localized and irreversible photothermal ablation of tumors in the mouse model is successfully achieved by using Bi2Se3 nanoplates and NIR laser irradiation. In addition, we also demonstrate that Bi2Se3 nanoplates exhibit strong X-ray attenuation and can be utilized for enhanced X-ray computed tomography imaging of tumor tissue in vivo. This study highlights Bi2Se3 nanoplates could serve as a promising platform for cancer diagnosis and therapy.

Arsenic induces functional re-expression of estrogen receptor α by demethylation of DNA in estrogen receptor-negative human breast cancer.

PubMed

Du, Juan; Zhou, Nannan; Liu, Hongxia; Jiang, Fei; Wang, Yubang; Hu, Chunyan; Qi, Hong; Zhong, Caiyun; Wang, Xinru; Li, Zhong

2012-01-01

Estrogen receptor α (ERα) is a marker predictive for response of breast cancers to endocrine therapy. About 30% of breast cancers, however, are hormone- independent because of lack of ERα expression. New strategies are needed for re-expression of ERα and sensitization of ER-negative breast cancer cells to selective ER modulators. The present report shows that arsenic trioxide induces reactivated ERα, providing a target for therapy with ER antagonists. Exposure of ER-negative breast cancer cells to arsenic trioxide leads to re-expression of ERα mRNA and functional ERα protein in in vitro and in vivo. Luciferase reporter gene assays and 3-(4,5-dimethylthiazol-2-yl)- 5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assays show that, upon exposure to arsenic trioxide, formerly unresponsive, ER-negative MDA-MB-231 breast cancer cells become responsive to ER antagonists, 4-hydroxytamoxifen and ICI 182,780. Furthermore, methylation- specific PCR and bisulfite-sequencing PCR assays show that arsenic trioxide induces partial demethylation of the ERα promoter. A methyl donor, S-adenosylmethionine (SAM), reduces the degree of arsenic trioxide-induced re-expression of ERα and demethylation. Moreover, Western blot and ChIP assays show that arsenic trioxide represses expression of DNMT1 and DNMT3a along with partial dissociation of DNMT1 from the ERα promoter. Thus, arsenic trioxide exhibits a previously undefined function which induces re-expression ERα in ER-negative breast cancer cells through demethylation of the ERα promoter. These findings could provide important information regarding the application of therapeutic agents targeting epigenetic changes in breast cancers and potential implication of arsenic trioxide as a new drug for the treatment of ER-negative human breast cancer.

Synthesis of bismuth titanate (BTO) nanopowder and fabrication of microstrip rectangular patch antenna

NASA Astrophysics Data System (ADS)

Thiruramanathan, P.; Sharma, Sanjeev K.; Sankar, S.; Sankar Ganesh, R.; Marikani, A.; Kim, Deuk Young

2016-12-01

The bismuth titanate (Bi4Ti3O12) or BTO nanopowder was synthesized from the combustion method and fabricated a microstrip rectangular patch antenna (MPA). The crystal structure and lattice spacing of BTO were evaluated from XRD, TEM, and SAED analysis. The crystal structure of BTO (annealed at 900 °C) was observed to be the orthorhombic phase with fcc lattice. The microstructure of BTO nanoparticles was confirmed the spherical and hexagonal shapes, which were slightly agglomerated due to the lack of stabilizing surfactants. The presence of weak and wide bands in Raman spectrum quantified the mechanical compressions to the uniform directions of elongated lattice constants and tensions to the lattice constriction of crystalline bismuth titanate. To fabricate the MPA, pellets of BTO nanopowder were prepared by applying the uniaxial pressure in the dimension of 1.5 mm thickness and 8 mm diameter. These pellets were formed a densely packed structure close to the theoretical density. The coercivity and remanence polarization of BTO ceramics increased as the applied field increased. The inexpensive combustion synthesis method of BTO nanopowder showed the high dielectric constant (ɛ' = 450) and low dielectric loss (tan δ = 0.98), which has a potential implication of the cost-effectiveness in the field of miniaturized microelectronics. The synthesis and measurements of BTO ceramics are found to be suitable for wireless communication systems.

Incorporation of polyoxotungstate complexes in silica spheres and in situ formation of tungsten trioxide nanoparticles.

PubMed

Zhao, Yuanyuan; Fan, Haimei; Li, Wen; Bi, Lihua; Wang, Dejun; Wu, Lixin

2010-09-21

In this paper, we demonstrated a new convenient route for in situ fabrication of well separated small sized WO(3) nanoparticles in silica spheres, through a predeposition of surfactant encapsulated polyoxotungates as tungsten source, and followed by a calcination process. In a typical procedure, selected polyoxotungates with different charges were enwrapped with dioctadecyldimethylammonium cations through electrostatic interaction. Elemental analysis, thermogravimetric analysis, and spectral characterization confirmed the formation of prepared complexes with the anticipated chemical structure. The complexes were then phase-transferred into aqueous solution that predissolved surfactant cetyltrimethylammonium bromide, and finally incorporated into silica spheres through a joint sol-gel reaction with tetraethyl orthosilicate in a well dispersed state under the protection of organic layer for polyoxotungates from the alkaline reaction condition. Transmission electron microscopic images illustrated the well dispersed WO(3) nanoparticles in the size range of ca. 2.2 nm in the silica spheres after the calcination at 465 °C. The sizes of both the silica spheres and WO(3) nanoparticles could be adjusted independently through changing the doping content to a large extent. Meanwhile, the doped polyoxotungate complexes acted as the template for the mesoporous structure in silica spheres after the calcination. Along with the increase of doping content and surfactant, the mesopore size changed little (2.0-2.9 nm), but the specific surface areas increased quite a lot. Importantly, the WO(3)-nanoparticle-doped silica spheres displayed an interesting photovoltaic property, which is favorable for the funtionalization of these nanomaterials.

Ultrasensitive hydrogen sensor based on Pt-decorated WO₃ nanorods prepared by glancing-angle dc magnetron sputtering.

PubMed

Horprathum, M; Srichaiyaperk, T; Samransuksamer, B; Wisitsoraat, A; Eiamchai, P; Limwichean, S; Chananonnawathorn, C; Aiempanakit, K; Nuntawong, N; Patthanasettakul, V; Oros, C; Porntheeraphat, S; Songsiriritthigul, P; Nakajima, H; Tuantranont, A; Chindaudom, P

2014-12-24

In this work, we report an ultrasensitive hydrogen (H2) sensor based on tungsten trioxide (WO3) nanorods decorated with platinum (Pt) nanoparticles. WO3 nanorods were fabricated by dc magnetron sputtering with a glancing angle deposition (GLAD) technique, and decorations of Pt nanoparticles were performed by normal dc sputtering on WO3 nanorods with varying deposition time from 2.5 to 15 s. Crystal structures, morphologies, and chemical information on Pt-decorated WO3 nanorods were characterized by grazing-incident X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and photoelectron spectroscopy, respectively. The effect of the Pt nanoparticles on the H2-sensing performance of WO3 nanorods was investigated over a low concentration range of 150-3000 ppm of H2 at 150-350 °C working temperatures. The results showed that the H2 response greatly increased with increasing Pt-deposition time up to 10 s but then substantially deteriorated as the deposition time increased further. The optimally decorated Pt-WO3 nanorod sensor exhibited an ultrahigh H2 response from 1530 and 214,000 to 150 and 3000 ppm of H2, respectively, at 200 °C. The outstanding gas-sensing properties may be attributed to the excellent dispersion of fine Pt nanoparticles on WO3 nanorods having a very large effective surface area, leading to highly effective spillover of molecular hydrogen through Pt nanoparticles onto the WO3 nanorod surface.

Structural and dielectric behaviors of Bi4Ti3O12 - lyotropic liquid crystalline nanocolloids

NASA Astrophysics Data System (ADS)

Shukla, Ravi K.; Raina, K. K.

2018-03-01

We investigated the structural and dielectric dynamics of nanocolloids comprising lyotropic liquid crystals and bismuth titanate (Bi4Ti3O12) spherical nanoparticles (≈16-18 nm) of varying concentration 0.05 and 0.1 wt%. The lyotropic liquid crystalline mixture was prepared by a binary mixture of cetylpyridinuium chloride and ethylene glycol mixed in 5:95 wt% ratio. Binary lyotropic mixture exhibited hexagonal lyotropic phase. Structural and textural characterizations of nanocolloids infer that the nanoparticles were homogeneously dispersed in the liquid crystalline matrix and did not perturb the hexagonal ordering of the lyotropic phase. The dielectric constant and dielectric strength were found to be increased with the rise in the Bi4Ti3O12 nanoparticles concertation in the lyotropic matrix. A significant increase of one order was observed in the ac conductivity of colloidal systems as compared to the non-doped lyotropic liquid crystal. Relaxation parameters of the non-doped lyotropic liquid crystal and colloidal systems were computed and correlated with other parameters.

Colloidal Synthesis of Te-Doped Bi Nanoparticles: Low-Temperature Charge Transport and Thermoelectric Properties.

PubMed

Gu, Da Hwi; Jo, Seungki; Jeong, Hyewon; Ban, Hyeong Woo; Park, Sung Hoon; Heo, Seung Hwae; Kim, Fredrick; Jang, Jeong In; Lee, Ji Eun; Son, Jae Sung

2017-06-07

Electronically doped nanoparticles formed by incorporation of impurities have been of great interest because of their controllable electrical properties. However, the development of a strategy for n-type or p-type doping on sub-10 nm-sized nanoparticles under the quantum confinement regime is very challenging using conventional processes, owing to the difficulty in synthesis. Herein, we report the colloidal chemical synthesis of sub-10 nm-sized tellurium (Te)-doped Bismuth (Bi) nanoparticles with precisely controlled Te content from 0 to 5% and systematically investigate their low-temperature charge transport and thermoelectric properties. Microstructural characterization of nanoparticles demonstrates that Te ions are successfully incorporated into Bi nanoparticles rather than remaining on the nanoparticle surfaces. Low-temperature Hall measurement results of the hot-pressed Te-doped Bi-nanostructured materials, with grain sizes ranging from 30 to 60 nm, show that the charge transport properties are governed by the doping content and the related impurity and nanoscale grain boundary scatterings. Furthermore, the low-temperature thermoelectric properties reveal that the electrical conductivity and Seebeck coefficient expectedly change with the Te content, whereas the thermal conductivity is significantly reduced by Te doping because of phonon scattering at the sites arising from impurities and nanoscale grain boundaries. Accordingly, the 1% Te-doped Bi sample exhibits a higher figure-of-merit ZT by ∼10% than that of the undoped sample. The synthetic strategy demonstrated in this study offers the possibility of electronic doping of various quantum-confined nanoparticles for diverse applications.

High-response and low-temperature nitrogen dioxide gas sensor based on gold-loaded mesoporous indium trioxide.

PubMed

Li, Shan; Cheng, Ming; Liu, Guannan; Zhao, Lianjing; Zhang, Bo; Gao, Yuan; Lu, Huiying; Wang, Haiyu; Zhao, Jing; Liu, Fangmeng; Yan, Xu; Zhang, Tong; Lu, Geyu

2018-04-10

Nitrogen dioxide (NO 2 ), as a typical threatening atmospheric pollutant, is hazardous to the environment and human health. Thus, the development of a gas sensor with high response and low detection limit for NO 2 detection is highly important. The highly ordered mesoporous indium trioxide (In 2 O 3 ) prepared by simple nanocasting method using mesoporous silica as template and decorated with Au nanoparticles was investigated for NO 2 detection. The prepared materials were characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. Characterization results showed that the samples exhibited ordered mesostructure and were successfully decorated with Au. The gas sensing performance of the sensors based on a series of Au-loaded mesoporous In 2 O 3 were systematically investigated. The Au loading level strongly affected the sensing performance toward NO 2 . The optimal sensor, which was based on 0.5 wt% Au-loaded In 2 O 3 , displayed high sensor response and low detection limit of 10 ppb at low operating temperature of 65 °C. The excellent sensing properties were mainly attributed to the ordered mesoporous structure and the catalytic performance of Au. We believe that the Au-loaded mesoporous In 2 O 3 can provide a promising platform for NO 2 gas sensors with excellent performance. Copyright © 2018 Elsevier Inc. All rights reserved.

A biography of arsenic and medicine in Hong Kong and China.

PubMed

Au, W Y

2011-12-01

Arsenic trioxide has been used in traditional Chinese medicine for over 5000 years, but lost its appeal due to its toxicity. It was rediscovered in western medicine and enjoyed a renaissance from 1830 to 1930, as the first effective chemotherapy against syphilis, parasites and leukaemia. These years were also a time of political turmoil in China. The Nanking treaty (29 August 1842) turned Hong Kong into a colony, while the Xinhai Revolution (10 October 1911) gave birth to a republic of China. Arsenic returned to China and Hong Kong with the establishment of the first medical schools from 1887 to 1920. Until 1950, oral arsenic trioxide was the standard anti-leukaemic treatment in Queen Mary Hospital. The advent of alkylating chemotherapeutic agents replaced arsenic trioxide in Hong Kong and around the world. In the 1970s, however, the specific activity of arsenic trioxide against acute promyelocytic leukaemia was re-discovered during the Cultural Revolution in Harbin, China. In 1997, Hong Kong was returned to China. In the same year, arsenic trioxide returned to the world stage. Intravenous arsenic trioxide became the worldwide standard therapy for relapsed acute promyelocytic leukaemia. Oral administration of arsenic trioxide was revived in Hong Kong in 2000. This resulted in the first locally produced, registered, patented prescription drug in Hong Kong. Pending imminent manufacture, this product is poised to revolutionise acute promyelocytic leukaemia care and may hold the key to saving the lives of acute promyelocytic leukaemia patients worldwide. The remarkable journey of arsenic in the setting of medical history of China and Hong Kong is reviewed.

Solution processable mixed-solvent exfoliated MoS2 nanosheets for efficient and robust organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Liu, Chia-Wei; Wang, Chia; Liao, Chia-Wei; Golder, Jan; Tsai, Ming-Chih; Young, Hong-Tsu; Chen, Chin-Ti; Wu, Chih-I.

2018-04-01

We demonstrate the use of solution-processed molybdenum trioxide (MoO3) nanoparticle-decorated molybdenum disulfide (MoS2) nanosheets (MoS2/MoO3) as hole injection layer (HIL) in organic lighting diodes (OLEDs). The device performance is shown to be significantly improved by the introduction of such MoS2/MoO3 HIL without any post-ultraviolet-ozone treatment, and is shown to better the performance of devices fabricated using conventional poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) and MoO3 nanoparticle HILs. The MoS2/MoO3 nanosheets form a compact film, as smooth as PEDOT:PSS films and smoother than MoO3 nanoparticle films, when simply spin-coated on indium tin oxide substrates. The improvement in device efficiency can be attributed to the smooth surface of the nanostructured MoS2/MoO3 HIL and the excellent conductivity characteristics of the two-dimensional (2D) layered material (MoS2), which facilitate carrier transport in the device and reduce the sheet resistance. Moreover, the long-term stability of OLED devices that use such MoS2/MoO3 layers is shown to be improved dramatically compared with hygroscopic and acidic PEDOT:PSS-based devices.

Bulk synthesis of inorganic fullerene-like MS{sub 2} (M = Mo, W) from the respective trioxides and the reaction mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feldman, Y.; Frey, G.L.; Homyonfer, M.

Recently, milligram quantities of MoS{sub 2} fullerene-like nanotubes and negative curvature polyhedra (generically called inorganic fullerene-like material, IF), were reproducibly obtained by a phase reaction from an oxide precursor. The present work focuses on the mechanism of the synthesis of IF-MS{sub 2} (M = W, Mo). The IF material is obtained from oxide particles smaller than ca. 0.2 {mu}m, while larger oxide particles result in 2H-MS{sub 2} platelets. The key step in the reaction mechanism is the formation of a closed layer of MS{sub 2}, which isolates the nanoparticle from its surroundings and prevents its fusion into larger particles. Subsequently,more » the oxide core of the nanoparticle is progressively converted into a sulfide nanoparticle with an empty core (IF). Taking advantage of this process, we report here a routine for the fabrication of macroscopic quantities of a pure IF-WS{sub 2} phase with a very high yield. As anticipated, the size distribution of the IF material is determined by the size distribution of the oxide precursor. The present synthesis paves the way for a systematic study of these materials which are promising candidates for, e.g., solid lubrication. 32 refs., 5 figs., 2 tabs.« less

Design of a new nanocomposite between bismuth nanoparticles and graphene oxide for development of electrochemical sensors.

PubMed

Bindewald, Eduardo H; Schibelbain, Arthur F; Papi, Maurício A P; Neiva, Eduardo G C; Zarbin, Aldo J G; Bergamini, Márcio F; Marcolino-Júnior, Luiz H

2017-10-01

This study describes a new route for preparation of a nanocomposite between graphene oxide (GO) and bismuth nanoparticles (BiNPs) and its evaluation as modifier electrode for development of electrochemical sensors. BiNPs were synthesized under ultrasound conditions using Bi(NO 3 ) 3 as metal precursor and ascorbic acid (AA) as reducing agent/passivating. Some experimental parameters of BiNPs synthesis such as Bi 3+ :AA molar ratio and reaction time were conducted aiming the best voltammetric performance of the sensor. Glassy carbon electrodes (GCE) were modified by drop-casting with the BiNPs dispersions and anodic stripping voltammetry measurements were performed and revealed an improvement in the sensitivityfor determination of Cd(II) and Pb(II) compared to an unmodified electrode. The best electrochemical response was obtained for a BiNPs synthesis with Bi 3+ :AA molar ratio of 1:6 and reaction time of 10min, which yielded Bi metallic nanoparticles with average size of 5.4nm confirmed by XRD and TEM images, respectively. GO was produced by graphite oxidation using potassium permanganate and exfoliated with an ultrasound tip. GO-BiNPs nanocomposite was obtained by a simple mixture of GO and BiNPs dispersions in water and kept under ultrasonic bath for 1h. GCE were modified with a nanocomposite suspension containing 0.3 and 1.5mgmL -1 of GO and BiNPs in water, respectively. Under optimized conditions, the proposed nanocomposite was evaluated on the voltammetric determination of Pb (II) and Cd (II), leading to a linear response range between 0.1 and 1.4μmolL -1 for both cations, with limit of detection of 30 and 27nmolL -1 , respectively. These results indicate the great potential of the GO-BiNPs nanocomposite for improving the sensitivity of voltammetric procedures. Copyright © 2017 Elsevier B.V. All rights reserved.

Structural and multiferroic properties of Ba2+ doped BiFeO3 nanoparticles synthesized via sol-gel method

NASA Astrophysics Data System (ADS)

Shisode, M. V.; Kharat, Prashant B.; Bhoyar, Dhananjay N.; Vinayak, Vithal; Babrekar, M. K.; Jadhav, K. M.

2018-05-01

Ba2+ doped Bismuth ferrite nanoparticles having general formula Bi1-xBaxFeO3 (where, x = 0.00 and 0.20) were successfully synthesized by sol gel method, using nitrates as a starting material. Ethylene glycol was used as a solvent. The synthesized powder was sintered at 650°C for 4 hours to obtain pure phase BFO. Leaching with dilute nitric acid (HNO3) and distilled water (H2O) is done to remove the impurities. The structural, morphological, magnetic and ferroelectric properties were systematically investigated using standard characterization techniques like X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and room temperature magnetic behavior of the samples was studied using pulse field hysteresis loop tracer technique showing increase in saturation magnetizaion. P-E loop confirms the ferroelectric behavior of prepared nanoparticles. The coexistence of ferromagnetic and ferroelectric hysteresis loops in BFO and Bi0.8Ba0.2FeO3 nanoparticles samples at room temperature; it indicates that the samples are potential candidates for information storage and spintronics devices. The increase in magnetic properties may be important for practical application at room temperature.

Effect of thalidomide and arsenic trioxide on the release of tumor necrosis factor-α and vascular endothelial growth factor from the KG-1a human acute myelogenous leukemia cell line.

PubMed

Girgis, Erian H; Mahoney, John P; Khalil, Rafaat H; Soliman, Magdi R

2010-07-01

Studies conducted in our lab have indicated that thalidomide cytotoxicity in the KG-1a human acute myelogenous leukemia (AML) cell line was enhanced by combining it with arsenic trioxide. The current investigation was conducted in order to evaluate the effect of thalidomide either alone or in combination with arsenic trioxide on the release of tumor necrosis factor-α (TNF-α) and vascular endothelial growth factor (VEGF) from this cell line in an attempt to clarify its possible cytotoxic mechanism(s). Human AML cell line KG-1a was used in this study. The cells were cultured for 48 h in the presence or absence of thalidomide (5 mg/l), and or arsenic trioxide (4 μM). The levels of TNF-α and VEGF in the supernatant were determined by ELISA. Results obtained indicate that the levels of TNF-α in the supernatant of KG-1a cell cultures incubated with thalidomide, arsenic trioxide, or combination were statistically lower than those observed in the supernatant of control cells (2.89, 5.07, 4.15 and 16.88 pg/ml, respectively). However, the levels of VEGF in the supernatant of thalidomide-treated cells were statistically higher than those in the supernatant of control cells (69.61 vs. 11.48 pg/l). Arsenic trioxide, whether alone or in combination with thalidomide, did not produce any statistically significant difference in the levels of VEGF as compared to the control or thalidomide-treated cell supernatant. These findings indicate that thalidomide and the arsenic trioxide inhibition of TNF-α production by KG-1a cells may play an important role in their cytotoxic effect.

Environmentally relevant concentration of arsenic trioxide and humic acid promoted tumor progression of human cervical cancer cells: In vivo and in vitro studies.

PubMed

Tsai, Min-Ling; Yen, Cheng-Chieh; Lu, Fung-Jou; Ting, Hung-Chih; Chang, Horng-Rong

2016-09-01

In a previous study, treatment at higher concentrations of arsenic trioxide or co-exposure to arsenic trioxide and humic acid was found to be inhibited cell growth of cervical cancer cells (SiHa cells) by reactive oxygen species generation. However, treatment at lower concentrations slightly increased cell viability. Here, we investigate the enhancement of progression effects of environmentally relevant concentration of humic acid and arsenic trioxide in SiHa cell lines in vitro and in vivo by measuring cell proliferation, migration, invasion, and the carcinogenesis-related protein (MMP-2, MMP-9, and VEGF-A) expressions. SiHa cells treated with low concentrations of humic acid and arsenic trioxide alone or in co-exposure significantly increased reactive oxygen species, glutathione levels, cell proliferation, scratch wound-healing activities, migration abilities, and MMP-2 expression as compared to the untreated control. In vivo the tumor volume of either single drug (humic acid or arsenic trioxide) or combined drug-treated group was significantly larger than that of the control for an additional 45 days after tumor cell injection on the back of NOD/SCID mice. Levels of MMP-2, MMP-9, and VEGF-A, also significantly increased compared to the control. Histopathologic effects of all tumor cells appeared round in cell shape with high mitosis, focal hyperkeratosis and epidermal hyperplasia in the skin, and some tumor growth in the muscle were observed. Our results may indicate that exposure to low concentrations of arsenic trioxide and humic acid is associated with the progression of cervical cancer. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1121-1132, 2016. © 2015 Wiley Periodicals, Inc.

Improved photoelectrochemical performance of BiVO4/MoO3 heterostructure thin films

NASA Astrophysics Data System (ADS)

Kodan, Nisha; Mehta, B. R.

2018-05-01

Bismuth vanadate (BiVO4) and Molybdenum trioxide (MoO3) thin films have been prepared by RF sputtering technique. BiVO4 thin films were deposited on indium doped tin oxide (In: SnO2; ITO) substrates at room temperature and 80W applied rf power. The prepared BiVO4 thin films were further annealed at 450°C for 2 hours in air to obtain crystalline monoclinic phase and successively coated with MoO3 thin films deposited at 150W rf power and 400°C for 30 minutes. The effect of coupling BiVO4 and MoO3 on the structural, optical and photoelectrochemical (PEC) properties have been studied. Optical studies reveal that coupling of BiVO4 and MoO3 results in improvement of optical absorption in visible region of solar spectrum. PEC study shows approximate 3-fold and 38-fold increment in photocurrent values of BiVO4/MoO3 (0.38 mA/cm2) heterostructure thin film as compared to MoO3 (0.15 mA/cm2) and BiVO4 (10 µA/cm2) thin films at applied bias of 1 V vs Ag/AgCl in 0.5 M Na2SO4 (pH=7) electrolyte.

Electronic structure of trioxide, oxoperoxide, oxosuperoxide, and ozonide clusters of the 3d elements: density functional theory study.

PubMed

Uzunova, Ellie L

2011-03-03

The trioxide clusters with stoichiometry MO3, and the structural isomers with side-on and end-on bonded oxygen atoms, are studied by DFT with the B1LYP functional. For the first half of the 3d elements row (Sc to Cr), pyramidal or distorted pyramidal structures dominate among the trioxide and oxoperoxide ground states, while the remaining elements form planar trioxides, oxoperoxides, oxosuperoxides, and ozonides. Low-lying trioxide clusters are formed by Ti, V, Cr, and Mn, among which the distorted pyramidal VO3 in the (2)A'' state, the pyramidal CrO3 in the (1)A1 state, and the planar MnO3 in the (2)A1' state are global minima. With the exception of the middle-row elements Mn, Fe, and Co, the magnetic moment of the ground-state clusters is formed with a major contribution from unpaired electrons located at the oxygen atoms. The stability of trioxides and oxoperoxides toward release of molecular oxygen is significantly higher for Sc, Ti, and V than for the remaining elements of the row. A trend of increasing the capability to dissociate one oxygen molecule is observed from Cr to Cu, with the exception of OFe(O2) being more reactive than OCo(O2). A gradual increase of reactivity from Ti to Cu is observed for the complete fragmentation reaction M + O + O2.

Effect of reducing agent strength on the growth and thermoelectric performance of nanocrystalline bismuth telluride

NASA Astrophysics Data System (ADS)

Nour, Asmaa; Hassan, Nazly; Refaat, Heba M.; Soliman, Hesham M. A.; El-Dissouky, A.

2018-03-01

A novel combination of Trizma, as an environmentally friendly chelating agent, with either weak or strong reducing agent was used to produce n-type bismuth telluride (Bi2Te3) nanocrystals via water-based chemical route. The synthesized powders were consolidated into pellets utilizing spark plasma sintering (SPS). The sintered n-type pellets exhibited potentially high electrical conductivities (5.29 × 105 and 5.23 × 105 S.m‑1) and low lattice thermal conductivities (0.12 and 0.25 Wm‑1K‑1) respectively. These thermoelectric (TE) properties suggested that the partially coherent boundaries permitted significant phonons scattering and electrons transfer. These led to an enhanced figure-of-merit (ZT) values (0.52 and 0.97), which are considered to be significant among the reported ZT values at room-temperature for the undoped synthesized n-type Bi2Te3 nanoparticles. Therefore, the current investigation displayed an efficient method to improve ZT of TE materials via nanostructure orchestrating, resulting in a worthy candidate n-type nanostructured Bi2Te3 for room-temperature TE applications.

40 CFR 116.4 - Designation of hazardous substances.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., ammonium sulfocyanide Amly acetate 628637 Amylacetic ester iso- 123922 Pear oil sec- 626380 Banana oil tert... Antimony trifluoride 7783564 Antimony fluoride Antimony trioxide 1309644 Diantimony trioxide, flowers of...

40 CFR 116.4 - Designation of hazardous substances.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., ammonium sulfocyanide Amly acetate 628637 Amylacetic ester iso- 123922 Pear oil sec- 626380 Banana oil tert... Antimony trifluoride 7783564 Antimony fluoride Antimony trioxide 1309644 Diantimony trioxide, flowers of...

40 CFR 116.4 - Designation of hazardous substances.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., ammonium sulfocyanide Amly acetate 628637 Amylacetic ester iso- 123922 Pear oil sec- 626380 Banana oil tert... Antimony trifluoride 7783564 Antimony fluoride Antimony trioxide 1309644 Diantimony trioxide, flowers of...

Temperature-dependent phase transition and comparative investigation on enhanced magnetic and optical properties between sillenite and perovskite bismuth ferrite-rGO nanocomposites

NASA Astrophysics Data System (ADS)

Jalil, M. A.; Chowdhury, Sayeed Shafayet; Alam Sakib, Mashnoon; Enamul Hoque Yousuf, S. M.; Khan Ashik, Emran; Firoz, Shakhawat H.; Basith, M. A.

2017-08-01

The manuscript reports the synthesis as well as a comparative investigation of the structural, magnetic, and optical properties between sillenite and perovskite type bismuth ferrite-reduced graphene oxide nanocomposites. Graphite oxide is prepared using the modified Hummers' method, followed by hydrothermal synthesis of bismuth ferrite-reduced graphene oxide nanocomposites at different reaction temperatures. The X-ray diffraction measurements confirm the formation of perovskite type BiFeO3-rGO nanocomposites at a reaction temperature of 200 °C. This is the lowest temperature to obtain perovskite type BiFeO3-rGO nanocomposites under the reaction procedure adopted, however, a structural transition to sillenite type Bi25FeO40-rGO is observed at 180 °C. The FESEM images demonstrate that the particle size of the perovskite nanocomposite is 25-60 nm, and for the sillenite phase nanocomposite it is 10-30 nm. The as-synthesized nanocomposites exhibit significantly enhanced saturation magnetization over pure BiFeO3 nanoparticles, with the sillenite Bi25FeO40-rGO nanocomposite having higher saturation magnetization than perovskite BiFeO3-rGO. The optical characteristics of the as-synthesized nanocomposites demonstrate considerably higher absorbance in the visible range with significantly lower band gap in comparison to undoped BiFeO3. Again, the sillenite Bi25FeO40-rGO nanocomposite is shown to have a lower band gap compared to the perovskite counterpart. Our investigation provides a means of selective phase formation as desired between sillenite Bi25FeO40-rGO and perovskite BiFeO3-rGO by controlling the hydrothermal reaction temperature. The outcome of our investigation suggests that the formation of nanocomposite of sillenite bismuth ferrite with reduced graphene oxide is promising to improve the magnetic and optical properties for potential technological applications.

METHOD FOR FORMING A COATING OF MOLYBDENUM CARBIDE ON A CARBON BODY

DOEpatents

Simnad, M.T.

1962-04-01

A method is described for coating a carbon bodywith molybdenum carbide in such a manner that the carbon body is rendered less permeable to the flow of gases and has increased resistance to corrosion and erosion. The method includes coating a carbon body with molybdenum trioxide by contacting it at a temperature below the condensation temperature with molybdenum trioxide vapors and thereafter carburizing the molybdenum trioxide in situ in an inert atmosphere on the carhon body. (AEC)

Determination of sulfur trioxide in engine exhaust.

PubMed Central

Arnold, D R

1975-01-01

Sulfur trioxide in the exhaust gas of an internal combustion engine is removed and concentrated by absorption in a solution of 80% isopropyl alcohol, which quantitatively absorbs it and inhibits the oxidation of any sulfur dioxide which may be absorbed. The absorbed sulfur trioxide (sulfuric acid) is determined by an absorption titration by using barium chloride as the titrant and thorin as the indicator. The sulfur dioxide content of the exhaust is measured continuously by means of a DuPont Model 411 ultraviolet photoanalyzer. PMID:50930

Bismuth subsalicylate nanoparticles with anaerobic antibacterial activity for dental applications

NASA Astrophysics Data System (ADS)

Vega-Jiménez, A. L.; Almaguer-Flores, A.; Flores-Castañeda, M.; Camps, E.; Uribe-Ramírez, M.; Aztatzi-Aguilar, O. G.; De Vizcaya-Ruiz, A.

2017-10-01

In recent years, nanomaterials have been used in the medical-dental field as new alternative antimicrobial agents. Bismuth subsalicylate (BSS) has been used as an antimicrobial agent, but the effect of BSS in the form of nanoparticles (BSS-nano) as a potential antimicrobial agent has not been tested, in specific against bacteria responsible for periodontal disease. The aim of this study was to evaluate the antibacterial effect of BSS-nano against oral anaerobic bacteria and to assess the safety of BSS-nano by evaluating their cytotoxicity in human gingival fibroblast (HGF-1) cells. BSS-nano were synthesized by laser ablation and were previously physico-chemically characterized using in vitro assays. The antibacterial activity was measured using the tetrazolium-based XTT assay, and cytotoxicity was determined using lactate dehydrogenase (LDH) and MTS assays in HGF-1 cells. Transmission electron microscopy of HGF-1 exposed to BSS-nano was also performed. BSS-nano was shown to have a primary size of 4-22 nm and a polygonal shape. Among the tested bacterial strains, those with a greater sensitivity to BSS-nano (highest concentration of 21.7 μg ml-1) were A. actinomycetemcomitans, C. gingivalis, and P. gingivalis. BSS-nano at a concentration of 60 μg ml-1 showed low cytotoxicity (6%) in HFG-1 cells and was mainly localized intracellularly in acidic vesicles. Our results indicate that the concentration of BSS-nano used as an effective antibacterial agent does not induce cytotoxicity in mammalian cells; thus, BSS-nano can be applied as an antibacterial agent in dental materials or antiseptic solutions.

40 CFR 61.180 - Applicability and designation of sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61... metallic arsenic production plant and to each arsenic trioxide plant that processes low-grade arsenic...

40 CFR 61.180 - Applicability and designation of sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61... metallic arsenic production plant and to each arsenic trioxide plant that processes low-grade arsenic...

Investigations on microstructure, electrical and magnetic properties of copper spinel ferrite with WO3 addition for applications in the humidity sensors

NASA Astrophysics Data System (ADS)

Tudorache, Florin

2018-04-01

In the present study we report the structural, electrical, magnetic and humidity characteristics of copper ferrite with different percent on tungsten trioxide addition. The aim of this study was to obtain more stable and sensitive active materials for humidity sensors. In order to highlight the influence of tungsten on the structural, electrical and magnetic properties, the ferrite samples were fabricated via sol-gel self-combustion method and sintered for 30 min at 1000 °C with percent between 0 and 20% tungsten trioxide additions. The X-ray diffraction investigations showed the copper ferrite phase composition. The scanning electron microscopy revealed the influence of the substitution on characteristics of the crystallites and the profilometry showed the surface topography of samples. The investigation was focused on the variation of permittivity and electrical conductivity, in relation with tungsten trioxide addition, frequency and humidity. We have also, investigated the relevant magnetic characteristics of the copper ferrite material by highlighting the influence of tungsten trioxide addition on to Curie temperature and the permeability frequency characteristics. The data suggests that the copper ferrite with tungsten trioxide addition can be used as active material for humidity sensors.

Pathogenesis and treatment of leukemia: an Asian perspective.

PubMed

Kwong, Yok-Lam

2012-03-01

Leukemias occur worldwide, but there are important geographic differences in incidences. Three leukemias with special Asian perspectives, acute promyelocytic leukemia (APL), T-cell large granular lymphocyte (T-LGL) leukemia and NK-cell leukemia. In APL, China has made contributions in discovering the efficacy of all-trans retinoic acid (ATRA) and arsenic trioxide. Some APL patients are potentially curable after treatment with ATRA or arsenic trioxide as a single agent. Combined treatment of APL with ATRA and arsenic trioxide induces remission with deeper molecular response. An oral formulation of arsenic trioxide is available, making outpatient treatment feasible. Future regimens for APL should examine how ATRA and arsenic trioxide can be optimally combined with other synergistic drugs. Asian patients with T-LGL leukemia present more frequently with pure red cell aplasia, but less frequently with neutropenia, recurrent infection, splenomegaly and rheumatoid arthritis as compared with Western patients. These differences have potential effects on treatment and disease pathogenesis. NK-cell leukemia is rapidly fatal and occurs almost exclusively in Asian and South American patients. Conventional anthracycline-based chemotherapy designed for B-cell lymphomas do not work in NK-cell leukemias. Novel therapeutic approaches targeting cellular signaling pathways or preferentially upregulated genes are needed to improve outcome.

Dose- and Time-Dependent Response of Human Leukemia (HL-60) Cells to Arsenic Trioxide Treatment

PubMed Central

Yedjou, Clement G.; Moore, Pamela; Tchounwou, Paul B.

2006-01-01

The treatment of acute promyelocytic leukemia (APL) has been based on the administration of all-trans retinoic acid plus anthracycline chemotherapy, which is very effective as first line therapy; however 25 to 30% of patients will relapse with their disease becoming refractory to conventional therapy. Recently, studies have shown arsenic trioxide to be effective in the treatment of acute promyelocytic leukemia. In this study, we used the human leukemia (HL-60) cell line as a model to evaluate the cytoxicity of arsenic trioxide based on the MTT assay. Data obtained from this assay indicated that arsenic trioxide significantly reduced the viability of HL-60 cells, showing LD50 values of 14.26 ± 0.5μg/mL, 12.54 ± 0.3μg/mL, and 6.4 ± 0.6μg/mL upon 6, 12, and 24 hours of exposure, respectively; indicating a dose- and time-dependent response relationship. Findings from the present study indicate that arsenic trioxide is highly cytotoxic to human leukemia (HL-60) cells, supporting its use as an effective therapeutic agent in the management of acute promyelocytic leukemia. PMID:16823087

Superfund Record of Decision (EPA region 8): North Dakota Arsenic Trioxide in Southeastern North Dakota, September 1986. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-09-26

The North Dakota Arsenic Trioxide site consists of twenty townships in Richland, Ransom, and Sargent counties in southeastern North Dakota. Ground water use includes residential consumption, irrigation, and livestock watering. The contamination, limited to ground water, appears to have two sources; naturally occurring arsenic contained in shales native to the area; and an estimated 330,000 pounds of arsenic-laced bait used to control grasshopper infestations in the 1930s and 1940s. The primary contaminant of concern is arsenic trioxide.

Antimony trioxide

Integrated Risk Information System (IRIS)

Antimony trioxide ; CASRN 1309 - 64 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

Gold nanoparticles production using reactor and cyclotron based methods in assessment of (196,198)Au production yields by (197)Au neutron absorption for therapeutic purposes.

PubMed

Khorshidi, Abdollah

2016-11-01

Medical nano-gold radioisotopes is produced regularly using high-flux nuclear reactors, and an accelerator-driven neutron activator can turn out higher yield of (197)Au(n,γ)(196,198)Au reactions. Here, nano-gold production via radiative/neutron capture was investigated using irradiated Tehran Research Reactor flux and also simulated proton beam of Karaj cyclotron in Iran. (197)Au nano-solution, including 20nm shaped spherical gold and water, was irradiated under Tehran reactor flux at 2.5E+13n/cm(2)/s for (196,198)Au activity and production yield estimations. Meanwhile, the yield was examined using 30MeV proton beam of Karaj cyclotron via simulated new neutron activator containing beryllium target, bismuth moderator around the target, and also PbF2 reflector enclosed the moderator region. Transmutation in (197)Au nano-solution samples were explored at 15 and 25cm distances from the target. The neutron flux behavior inside the water and bismuth moderators was investigated for nano-gold particles transmutation. The transport of fast neutrons inside bismuth material as heavy nuclei with a lesser lethargy can be contributed in enhanced nano-gold transmutation with long duration time than the water moderator in reactor-based method. Cyclotron-driven production of βeta-emitting radioisotopes for brachytherapy applications can complete the nano-gold production technology as a safer approach as compared to the reactor-based method. Copyright © 2016 Elsevier B.V. All rights reserved.

Antimony Trioxide (ATO) - Summary of External Peer Review and Public Comments and Disposition

EPA Pesticide Factsheets

This document summarizes the public and external peer review comments that the EPA’s Office of Pollution Prevention and Toxics (OPPT) received for the draft work plan risk assessment for Antimony Trioxide (ATO).

Effect of addition of nano-hydroxyapatite on physico-chemical and antibiofilm properties of calcium silicate cements

PubMed Central

GUERREIRO-TANOMARU, Juliane Maria; VÁZQUEZ-GARCÍA, Fernando Antonio; BOSSO-MARTELO, Roberta; BERNARDI, Maria Inês Basso; FARIA, Gisele; TANOMARU, Mario

2016-01-01

ABSTRACT Objective Mineral Trioxide Aggregate (MTA) is a calcium silicate cement composed of Portland cement (PC) and bismuth oxide. Hydroxyapatite has been incorporated to enhance mechanical and biological properties of dental materials. This study evaluated physicochemical and mechanical properties and antibiofilm activity of MTA and PC associated with zirconium oxide (ZrO2) and hydroxyapatite nanoparticles (HAn). Material and Methods White MTA (Angelus, Brazil); PC (70%)+ZrO2 (30%); PC (60%)+ZrO2 (30%)+HAn (10%); PC (50%)+ZrO2 (30%)+HAn (20%) were evaluated. The pH was assessed by a digital pH-meter and solubility by mass loss. Setting time was evaluated by using Gilmore needles. Compressive strength was analyzed by mechanical test. Samples were radiographed alongside an aluminum step wedge to evaluate radiopacity. For the antibiofilm evaluation, materials were placed in direct contact with E. faecalis biofilm induced on dentine blocks. The number of colony-forming units (CFU mL-1) in the remaining biolfilm was evaluated. The results were submitted to ANOVA and the Tukey test, with 5% significance. Results There was no difference in pH levels of PC+ZrO2, PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p>0.05) and these cements presented higher pH levels than MTA (p<0.05). The highest solubility was observed in PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p<0.05). MTA had the shortest initial setting time (p<0.05). All the materials showed radiopacity higher than 3 mmAl. PC+ZrO2 and MTA had the highest compressive strength (p<0.05). Materials did not completely neutralize the bacterial biofilm, but the association with HAn provided greater bacterial reduction than MTA and PC+ZrO2 (p<0.05) after the post-manipulation period of 2 days. Conclusions The addition of HAn to PC associated with ZrO2 harmed the compressive strength and solubility. On the other hand, HAn did not change the pH and the initial setting time, but improved the radiopacity (HAn 10%), the final setting time and the E. faecalis antibiofilm activity of the cement. PMID:27383700

Polymer-pyrolysis assisted synthesis of vanadium trioxide and carbon nanocomposites as high performance anode materials for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Dong, Yucheng; Ma, Ruguang; Hu, Mingjun; Cheng, Hua; Lee, Jong-Min; Li, Yang Yang; Zapien, Juan Antonio

2014-09-01

We present a simple polymer-pyrolysis assisted method to prepare vanadium trioxide and carbon nanocomposites as an advanced anode material for lithium-ion batteries. The as-prepared material deliver a superior battery performance with highly retained capacity of ∼780 mAh g-1 over 100 cycles at a current density of 200 mA g-1, showing excellent cyclic stability, and good rate capability. The improved electrochemical performance of vanadium trioxide and carbon nanocomposites electrode makes it promising as a suitable anode material for practical battery applications.

Acute promyelocytic leukaemia: novel insights into the mechanisms of cure.

PubMed

de Thé, Hugues; Chen, Zhu

2010-11-01

The fusion oncogene, promyelocytic leukaemia (PML)-retinoic acid receptor-α (RARA), initiates acute promyelocytic leukaemia (APL) through both a block to differentiation and increased self-renewal of leukaemic progenitor cells. The current standard of care is retinoic acid (RA) and chemotherapy, but arsenic trioxide also cures many patients with APL, and an RA plus arsenic trioxide combination cures most patients. This Review discusses the recent evidence that reveals surprising new insights into how RA and arsenic trioxide cure this leukaemia, by targeting PML-RARα for degradation. Drug-triggered oncoprotein degradation may be a strategy that is applicable to many cancers.

Dendrimer-stabilized bismuth sulfide nanoparticles: synthesis, characterization, and potential computed tomography imaging applications.

PubMed

Fang, Yi; Peng, Chen; Guo, Rui; Zheng, Linfeng; Qin, Jinbao; Zhou, Benqing; Shen, Mingwu; Lu, Xinwu; Zhang, Guixiang; Shi, Xiangyang

2013-06-07

We report here a general approach to synthesizing dendrimer-stabilized bismuth sulfide nanoparticles (Bi2S3 DSNPs) for potential computed tomography (CT) imaging applications. In this study, ethylenediamine core glycidol hydroxyl-terminated generation 4 poly(amidoamine) dendrimers (G4.NGlyOH) were used as stabilizers to first complex the Bi(III) ions, followed by reaction with hydrogen sulfide to generate Bi2S3 DSNPs. By varying the molar ratio of Bi atom to dendrimer, stable Bi2S3 DSNPs with an average size range of 5.2-5.7 nm were formed. The formed Bi2S3 DSNPs were characterized via different techniques. X-ray absorption coefficient measurements show that the attenuation of Bi2S3 DSNPs is much higher than that of iodine-based CT contrast agent at the same molar concentration of the active element (Bi versus iodine). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assay and hemolysis assay reveal that the formed Bi2S3 DSNPs are noncytotoxic and have a negligible hemolysis effect in the studied concentration range. Furthermore, we show that cells incubated with the Bi2S3 DSNPs are able to be imaged using CT, a prominent enhancement at the point of rabbit injected subcutaneously with the Bi2S3 DSNPs is able to be visualized via CT scanning, and the mouse's pulmonary vein can be visualized via CT after intravenous injection of the Bi2S3 DSNPs. With the good biocompatibility, enhanced X-ray attenuation property, and tunable dendrimer chemistry, the designed Bi2S3 DSNPs should be able to be further functionalized, allowing them to be used as a highly efficient contrast agent for CT imaging of different biological systems.

40 CFR 61.183 - Emission monitoring.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.183 Emission monitoring. (a... arsenic trioxide and metallic arsenic process emission stream that exits from a control device. (b) The...

40 CFR 61.183 - Emission monitoring.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.183 Emission monitoring. (a... arsenic trioxide and metallic arsenic process emission stream that exits from a control device. (b) The...

Bismuth Subgallate Toxicity in the Age of Online Supplement Use.

PubMed

Sampognaro, Paul; Vo, Kathy T; Richie, Megan; Blanc, Paul D; Keenan, Kevin

2017-11-01

Bismuth salts have been used to treat gastroenterological disorders and are readily available over-the-counter and via the internet. Even though generally considered safe, bismuth compounds can cause a syndrome of subacute, progressive encephalopathy when taken in large quantities. We present the case of woman who developed progressive encephalopathy, aphasia, myoclonus, and gait instability after chronically ingesting large amounts of bismuth subgallate purchased from a major online marketing website to control symptoms of irritable bowel syndrome. After extensive neurological work-up, elevated bismuth levels in her blood, urine, and cerebrospinal fluid confirmed the diagnosis of bismuth-related neurotoxicity. She improved slowly following cessation of exposure. This case highlights bismuth subgallate as a neurotoxic bismuth formulation and reminds providers of the potential for safety misconceptions of positively reviewed online supplements.

Effects of a discoloration-resistant calcium aluminosilicate cement on the viability and proliferation of undifferentiated human dental pulp stem cells.

PubMed

Niu, Li-na; Watson, Devon; Thames, Kyle; Primus, Carolyn M; Bergeron, Brian E; Jiao, Kai; Bortoluzzi, Eduardo A; Cutler, Christopher W; Chen, Ji-hua; Pashley, David H; Tay, Franklin R

2015-11-30

Discoloration-resistant calcium aluminosilicate cement has been formulated to overcome the timely problem of tooth discoloration reported in the clinical application of bismuth oxide-containing hydraulic cements. The present study examined the effects of this experimental cement (Quick-Set2) on the viability and proliferation of human dental pulp stem cells (hDPSCs) by comparing the cellular responses with commercially available calcium silicate cement (white mineral trioxide aggregate; WMTA) after different aging periods. Cell viability and proliferation were examined using assays that examined plasma membrane integrity, leakage of cytosolic enzyme, caspase-3 activity for early apoptosis, oxidative stress, mitochondrial metabolic activity and intracellular DNA content. Results of the six assays indicated that both Quick-Set2 and WMTA were initially cytotoxic to hDPSCs after setting for 24 h, with Quick-Set2 being comparatively less cytotoxic than WMTA at this stage. After two aging cycles, the cytotoxicity profiles of the two hydraulic cements were not significantly different and were much less cytotoxic than the positive control (zinc oxide-eugenol cement). Based on these results, it is envisaged that any potential beneficial effect of the discoloration-resistant calcium aluminosilicate cement on osteogenesis by differentiated hDPSCs is more likely to be revealed after outward diffusion and removal of its cytotoxic components.

Effects of a discoloration-resistant calcium aluminosilicate cement on the viability and proliferation of undifferentiated human dental pulp stem cells

PubMed Central

Niu, Li-na; Watson, Devon; Thames, Kyle; Primus, Carolyn M.; Bergeron, Brian E.; Jiao, Kai; Bortoluzzi, Eduardo A.; Cutler, Christopher W.; Chen, Ji-hua; Pashley, David H.; Tay, Franklin R.

2015-01-01

Discoloration-resistant calcium aluminosilicate cement has been formulated to overcome the timely problem of tooth discoloration reported in the clinical application of bismuth oxide-containing hydraulic cements. The present study examined the effects of this experimental cement (Quick-Set2) on the viability and proliferation of human dental pulp stem cells (hDPSCs) by comparing the cellular responses with commercially available calcium silicate cement (white mineral trioxide aggregate; WMTA) after different aging periods. Cell viability and proliferation were examined using assays that examined plasma membrane integrity, leakage of cytosolic enzyme, caspase-3 activity for early apoptosis, oxidative stress, mitochondrial metabolic activity and intracellular DNA content. Results of the six assays indicated that both Quick-Set2 and WMTA were initially cytotoxic to hDPSCs after setting for 24 h, with Quick-Set2 being comparatively less cytotoxic than WMTA at this stage. After two aging cycles, the cytotoxicity profiles of the two hydraulic cements were not significantly different and were much less cytotoxic than the positive control (zinc oxide–eugenol cement). Based on these results, it is envisaged that any potential beneficial effect of the discoloration-resistant calcium aluminosilicate cement on osteogenesis by differentiated hDPSCs is more likely to be revealed after outward diffusion and removal of its cytotoxic components. PMID:26617338

Spectroscopic Characterization of Extracellular Polymeric Substances from Escherichia coli and Serratia marcescens: Suppression using Sub-Inhibitory Concentrations of Bismuth Thiols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Badireddy, Appala R.; Korpol, Bhoom Reddy; Chellam, Shankararaman

2008-10-21

Free and capsular EPS produced by Escherichia coli and Serratia marcescens were characterized in detail using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). Total EPS production decreased upon treatment with sub-inhibitory concentrations of lipophilic bismuth thiols (bismuth dimercaptopropanol, BisBAL; bismuth ethanedithiol, BisEDT; and bismuth pyrithione, BisPYR), BisBAL being most effective. Bismuth thiols also influenced acetylation and carboxylation of polysaccharides in EPS from S. marcescens. Extensive homology between EPS samples in the presence and absence of bismuth was observed with proteins, polysaccharides, and nucleic acids varying predominantly only in the total amount expressed. Secondmore » derivative analysis of the amide I region of FTIR spectra revealed decreases in protein secondary structures in the presence of bismuth thiols. Hence, anti-fouling properties of bismuth thiols appear to originate in their ability to suppress O-acetylation and protein secondary structures in addition to total EPS secretion.« less

Structural determination of Bi-doped magnetite multifunctional nanoparticles for contrast imaging.

PubMed

Laguna-Marco, M A; Piquer, C; Roca, A G; Boada, R; Andrés-Vergés, M; Veintemillas-Verdaguer, S; Serna, C J; Iadecola, A; Chaboy, J

2014-09-14

To determine with precision how Bi atoms are distributed in Bi-doped iron oxide nanoparticles their structural characterization has been carried out by X-ray absorption spectroscopy (XAS) recorded at the K edge of Fe and at the L3 edge of Bi. The inorganic nanoparticles are nominally hybrid structures integrating an iron oxide core and a bismuth oxide shell. Fe K-edge XAS indicates the formation of a structurally ordered, non-stoichiometric magnetite (Fe3-δO4) phase for all the nanoparticles. The XAS spectra show that, in the samples synthesized by precipitation in aqueous media and laser pyrolysis, the Bi atoms neither enter into the iron oxide spinel lattice nor form any other mixed Bi-Fe oxides. No modification of the local structure around the Fe atoms induced by the Bi atoms is observed at the Fe K edge. In addition, contrary to expectations, our results indicate that the Bi atoms do not form a well-defined Bi oxide structure. The XAS study at the Bi L3 edge indicates that the environment around Bi atoms is highly disordered and only a first oxygen coordination shell is observed. Indefinite [BiO6-x(OH)x] units (isolated or aggregated forming tiny amorphous clusters) bonded through hydroxyl bridges to the nanoparticle, rather than a well defined Bi2O3 shell, surround the nanoparticle. On the other hand, the XAS study indicates that, in the samples synthesized by thermal decomposition, the Bi atoms are embedded in a longer range ordered structure showing the first and second neighbors.

SEPARATION OF PLUTONIUM HYDROXIDE FROM BISMUTH HYDROXIDE

DOEpatents

Watt, G.W.

1958-08-19

An tmproved method is described for separating plutonium hydroxide from bismuth hydroxide. The end product of the bismuth phosphate processes for the separation amd concentration of plutonium is a inixture of bismuth hydroxide amd plutonium hydroxide. It has been found that these compounds can be advantageously separated by treatment with a reducing agent having a potential sufficient to reduce bismuth hydroxide to metalltc bisinuth but not sufficient to reduce the plutonium present. The resulting mixture of metallic bismuth and plutonium hydroxide can then be separated by treatment with a material which will dissolve plutonium hydroxide but not metallic bismuth. Sodiunn stannite is mentioned as a preferred reducing agent, and dilute nitric acid may be used as the separatory solvent.

METHOD OF MAKING UO$sub 2$-Bi SLURRIES

DOEpatents

Hahn, H.T.

1960-05-24

A process is given of preparing an easily dispersible slurry of uranium dioxide in bismuth. A mixture of bismuth oxide, uranium, and bismuth are heated in a capsule to a temperature over the melting point of bismuth oxide. The amount of bismuth oxide used is less than that stoichiometrically required because the oxygen in the capsule also enters into the reaction.

Carbon nanostructured films modified by metal nanoparticles supported on filtering membranes for electroanalysis.

PubMed

Paramo, Erica; Palmero, Susana; Heras, Aranzazu; Colina, Alvaro

2018-02-01

A novel methodology to prepare sensors based on carbon nanostructures electrodes modified by metal nanoparticles is proposed. As a proof of concept, a novel bismuth nanoparticle/carbon nanofiber (Bi-NPs/CNF) electrode and a carbon nanotube (CNT)/gold nanoparticle (Au-NPs) have been developed. Bi-NPs/CNF films were prepared by 1) filtering a dispersion of CNFs on a polytetrafluorethylene (PTFE) filter, and 2) filtering a dispersion of Bi-NPs chemically synthesized through this CNF/PTFE film. Next the electrode is prepared by sticking the Bi-NPs/CNF/PTFE film on a PET substrate. In this work, Bi-NPs/CNF ratio was optimized using a Cd 2+ solution as a probe sample. The Cd anodic stripping peak intensity, registered by differential pulse anodic stripping voltammetry (DPASV), is selected as target signal. The voltammograms registered for Cd stripping with this Bi-NPs/CNF/PTFE electrode showed well-defined and highly reproducible electrochemical. The optimized Bi-NPs/CNF electrode exhibits a Cd 2+ detection limit of 53.57 ppb. To demonstrate the utility and versatility of this methodology, single walled carbon nanotubes (SWCNTs) and gold nanoparticles (Au-NPs) were selected to prepare a completely different electrode. Thus, the new Au-NPs/SWCNT/PTFE electrode was tested with a multiresponse technique. In this case, UV/Vis absorption spectroelectrochemistry experiments were carried out for studying dopamine, demonstrating the good performance of the Au-NPs/SWCNT electrode developed. Copyright © 2017 Elsevier B.V. All rights reserved.

Layer structured bismuth selenides Bi2Se3 and Bi3Se4 for high energy and flexible all-solid-state micro-supercapacitors.

PubMed

Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

2018-01-19

In this work, bismuth selenides (Bi 2 Se 3 and Bi 3 Se 4 ), both of which have a layered rhombohedral crystal structure, have been found to be useful as electrode materials for supercapacitor applications. In a liquid electrolyte system (6M KOH), Bi 2 Se 3 nanoplates exhibit much better performance as an electrode material than Bi 3 Se 4 nanoparticles do, delivering a higher specific capacitance (272.9 F g -1 ) than that of Bi 3 Se 4 (193.6 F g -1 ) at 5 mV s -1 . This result may be attributed to the fact that Bi 2 Se 3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to their planar quintuple stacked layers (septuple layers for Bi 3 Se 4 ). To meet the demands of electronic skin, we used a novel flexible annular interdigital structure electrode to support the all-solid-state micro-supercapacitors (AMSCs). The Bi 2 Se 3 AMSC device delivers a much better supercapacitor performance, exhibits a large stack capacitance of 89.5 F cm -3 at 20 mV s -1 (Bi 3 Se 4 : 79.1 F cm -3 ), a high energy density of 17.9 mWh cm -3 and a high power density of 18.9 W cm -3 . The bismuth selenides also exhibit good cycle stability, with 95.5% retention after 1000 c for Bi 2 Se 3 (Bi 3 Se 4 :90.3%). Clearly, Bi 2 Se 3 nanoplates can be promising electrode materials for flexible annular interdigital AMSCs.

Layer Structured Bismuth Selenides of Bi₂Se₃ and Bi₃Se₄ for High Energy and Flexible All-Solid-State Micro-Supercapacitors.

PubMed

Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

2017-12-20

Bismuth selenides (Bi2Se3 and Bi3Se4), both of which have the layered rhombohedral crystal structure, and found to be useful as electrode materials for supercapacitor application in this work. Bi2Se3 nanoplates as electrode material exhibit much better performance than that of Bi3Se4 nanoparticles in liquid electrolyte system (6 M KOH), which delivers a higher specific capacitance (272.9 F/g) than that of Bi3Se4 (193.6 F/g) at 5 mV/s. This result would may be attributed to that Bi2Se3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to its planar quintuple stacked layers (septuple layers for Bi3Se4). For the demand of electronic skin, we used a novel flexible annular interdigital structure electrode applying for all-solid-state micro-supercapacitors (AMSCs). Bi2Se3 AMSCs device delivers a much more excellent supercapacitor performance, exhibits a large stack capacitance 89.5 F/cm3 (Bi3Se4: 79.1 F/cm3) at 20 mV/s, a high energy density 17.9 mWh/cm3 and high power density 18.9 W/cm3. The bismuth selenides also exhibit good cycle stability, retention 95.5% (90.3%) after 1000 c for Bi2Se3 (Bi3Se4). Obviously, Bi2Se3 nanoplates can be promising electrode materials for flexible annular interdigital all-solid-sate supercapacitor. © 2017 IOP Publishing Ltd.

Layer structured bismuth selenides Bi2Se3 and Bi3Se4 for high energy and flexible all-solid-state micro-supercapacitors

NASA Astrophysics Data System (ADS)

Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

2018-02-01

In this work, bismuth selenides (Bi2Se3 and Bi3Se4), both of which have a layered rhombohedral crystal structure, have been found to be useful as electrode materials for supercapacitor applications. In a liquid electrolyte system (6M KOH), Bi2Se3 nanoplates exhibit much better performance as an electrode material than Bi3Se4 nanoparticles do, delivering a higher specific capacitance (272.9 F g-1) than that of Bi3Se4 (193.6 F g-1) at 5 mV s-1. This result may be attributed to the fact that Bi2Se3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to their planar quintuple stacked layers (septuple layers for Bi3Se4). To meet the demands of electronic skin, we used a novel flexible annular interdigital structure electrode to support the all-solid-state micro-supercapacitors (AMSCs). The Bi2Se3 AMSC device delivers a much better supercapacitor performance, exhibits a large stack capacitance of 89.5 F cm-3 at 20 mV s-1 (Bi3Se4: 79.1 F cm-3), a high energy density of 17.9 mWh cm-3 and a high power density of 18.9 W cm-3. The bismuth selenides also exhibit good cycle stability, with 95.5% retention after 1000 c for Bi2Se3 (Bi3Se4:90.3%). Clearly, Bi2Se3 nanoplates can be promising electrode materials for flexible annular interdigital AMSCs.

Lipid encapsulation of arsenic trioxide attenuates cytotoxicity and allows for controlled anticancer drug release.

PubMed

Chen, Haimei; MacDonald, Robert C; Li, Shuyou; Krett, Nancy L; Rosen, Steven T; O'Halloran, Thomas V

2006-10-18

Arsenic trioxide (ATO, As2O3) is emerging as a front line agent for treatment of acute promyelocytic leukemia with giving a complete remission rate of 83-95%. ATO also shows significant activity in relapsed/refactory multiple myeloma; however, efforts to expand clinical utility to other cancers have been limited by its toxicity profile at higher doses. New bioavailable, liposome encapsulated As(III) materials exhibit a significantly attenuated cytotoxicity that undergoes pH-triggered release of an active drug. The arsenic drugs are loaded into 100-nm-scale liposomes at high concentration (>270 mM) and excellent retention (shelf life > 6 months at 4 degrees C), as determined by inductively coupled plasma optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM), and energy-dispersive X-ray (EDX) diffraction. In the loading mechanism, arsenous acid crosses the bilayer membrane in exchange for acetic acid and an insoluble transitional metal (e.g., Ni2+, Co2+) arsenite salt is formed. The resultant liposomal arsenic nanoparticles appear to be stable in physiological situations but release the drug cargo in a lower pH environment, as encountered in intracellular endosomes. These drugs exhibit attenuated cytotoxicities against human lymphoma tumor cells compared with that of free As2O3. Controlled release of arsenic drugs, and hence control of toxicity, is feasible with this system. The results demonstrate that cytotoxicity can be controlled via transitions of the inorganic drug between solid and solution phases and suggest a mechanism for further improvement of the risk/benefit ratio of As2O3 in treatment of a variety of cancers.

Hexagonal nanorods of tungsten trioxide: Synthesis, structure, electrochemical properties and activity as supporting material in electrocatalysis

NASA Astrophysics Data System (ADS)

Salmaoui, Samiha; Sediri, Faouzi; Gharbi, Néji; Perruchot, Christian; Aeiyach, Salah; Rutkowska, Iwona A.; Kulesza, Pawel J.; Jouini, Mohamed

2011-07-01

Tungsten trioxide, unhydrated with hexagonal structure (h-WO 3), has been prepared by hydrothermal method at a temperature of 180 °C in acidified sodium tungstate solution. Thus prepared h-WO 3 has been characterized by X-ray diffraction (XRD) method and using electrochemical techniques. The morphology has been examined by scanning and transmission electron microscopies (SEM and TEM) and it is consistent with existence of nanorods of 50-70 nm diameter and up to 5 μm length. Cyclic voltammetric characterization of thin films of h-WO 3 nanorods has revealed reversible redox behaviour with charge-discharge cycling corresponding to the reversible lithium intercalation/deintercalation into the crystal lattice of the h-WO 3 nanorods. In propylene carbonate containing LiClO 4, two successive redox processes of hexagonal WO 3 nanorods are observed at the scan rate of 50 mV/s. Such behaviour shall be attributed to the presence of at least two W atoms of different surroundings in the lattice structure of h-WO 3 nanorods. On the other hand, in aqueous LiClO 4 solution, only one redox process is observed at the scan rate of 10 mV/s. The above observations can be explained in terms of differences in the diffusion of ions inside two types of channel cavities existing in the structure of the h-WO 3 nanorods. Moreover, the material can be applied as active support for the catalytic bi-metallic Pt-Ru nanoparticles during electrooxidation of ethanol in acid medium (0.5 mol dm -3 H 2SO 4).

Physiochemical properties of experimental nano-hybrid MTA

PubMed Central

Akhavan Zanjani, V; Tabari, K; Sheikh-Al-Eslamian, SM; Abrandabadi, AN

2017-01-01

Introduction: Development of new pulp capping agents has paved the way towards the preservation of pulp vitality, which is an important goal in restorative dentistry. This study sought to assess the calcium ion release, pH and setting of mineral trioxide aggregate (MTA) Angelus, an experimental formulation of nano-hybrid MTA containing nano-SiO2, nano-Al2O3 and nano-TiO2 and MTA Angelus plus nano-oxides. Methods: In this experimental study, five specimens from each material were placed in polypropylene tubes and immersed in a flask containing deionized distilled water. The quantity of calcium ions released into the solution from each material was measured at 15 minutes, one hour, and 24 hours by using atomic absorption spectroscopy. The pH of the solutions was measured by using a pH meter at the respective time points. The setting time was also assessed by using a Gilmore needle. Data were analyzed by using repeated measure ANOVA. Results: The quantity of released calcium ions was not significantly different among the groups (P=0.060). All materials were alkaline and the pH at 24 hours was significantly higher than the other two time points in all groups (P<0.001). The experimental group had the shortest and the MTA Angelus had the longest setting time. All materials were alkaline and capable of releasing calcium. Addition of nanoparticles to MTA Angelus significantly decreased the setting time but had no effect on the release of calcium ions or pH. Abbreviations: MTA = mineral trioxide aggregate, VPT = vital pulp therapy PMID:29075348

EMISSIONS OF SULFUR TRIOXIDE FROM COAL-FIRED POWER PLANTS

EPA Science Inventory

Emissions of sulfur trioxide (SO3) are a key component of plume opacity and acid deposition. Consequently, these emissions need to be low enough not to cause opacity violations and acid deposition. Generally, a small fraction of sulfur in coal is converted to SO3 in coal-fired co...

Bismuth-doped optical fibres: A new breakthrough in near-IR lasing media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dianov, Evgenii M

Recent results demonstrate that bismuth-doped optical fibres have considerable potential as near-IR active lasing media. This paper examines bismuth-doped fibres intended for the fabrication of fibre lasers and optical amplifiers and reviews recent results on the luminescence properties of various types of bismuth-doped fibres and the performance of bismuth-doped fibre lasers and optical amplifiers for the spectral range 1150 - 1550 nm. Problems are discussed that have yet to be solved in order to improve the efficiency of the bismuth lasers and optical amplifiers. (optical fibres, lasers and amplifiers. properties and applications)

Influence of cobalt doping on structural and magnetic properties of BiFeO3 nanoparticles

NASA Astrophysics Data System (ADS)

Khan, U.; Adeela, N.; Javed, K.; Riaz, S.; Ali, H.; Iqbal, M.; Han, X. F.; Naseem, S.

2015-11-01

Nanocrystalline cobalt-doped bismuth ferrites with general formula of BiFe1- δ Co δ O3 (0 ≤ δ ≤ 0.1) have been synthesized using solution evaporation method. Structure and phase identification was performed with X-ray diffraction (XRD) technique. The results confirm the formation of rhombohedral-distorted Perovskite structure with R3c symmetry. A decrease in lattice parameters and an increase in X-ray density have been observed with increasing cobalt concentration in BiFeO3. Particle size determined by transmission electron microscope was in good agreement with XRD, i.e., 39 nm. Room-temperature coercivity and saturation magnetization of nanoparticles were increased up to 7.5 % of cobalt doping. Low-temperature magnetic measurements of selected sample showed increasing behavior in saturation magnetization, coercivity, effective magnetic moments, and anisotropy constant. An increase in coercivity with decrease in temperature followed theoretical model of Kneller's law, while modified Bloch's model was employed for saturation magnetization in temperature range of 5-300 K.

Chemical structure of bismuth compounds determines their gastric ulcer healing efficacy and anti-Helicobacter pylori activity.

PubMed

Sandha, G S; LeBlanc, R; Van Zanten, S J; Sitland, T D; Agocs, L; Burford, N; Best, L; Mahoney, D; Hoffman, P; Leddin, D J

1998-12-01

The recognition of the role of Helicobacter pylori in the pathogenesis of peptic ulcer disease has led to renewed interest in bismuth pharmacology since bismuth compounds have both anti-Helicobacter pylori and ulcer healing properties. The precise chemical structure of current bismuth compounds is not known. This has hindered the development of new and potentially more efficacious formulations. We have created two new compounds, 2-chloro-1,3-dithia-2-bismolane (CDTB) and 1,2-[bis(1,3-dithia-2-bismolane)thio]ethane (BTBT), with known structure. In a rat model of gastric ulceration, BTBT was comparable to, and CDTB was significantly less effective than colloidal bismuth subcitrate in healing cryoprobe-induced ulcers. However, both BTBT and CDTB inhibited H. pylori growth in vitro at concentrations <1/10 that of colloidal bismuth subcitrate. The effects on ulcer healing are not mediated by suppression of acid secretion, pepsin inhibition, or prostaglandin production. Since all treated animals received the same amount of elemental bismuth, it appears that the efficacy of bismuth compounds varies with compound structure and is not simply dependent on the delivery of bismuth ion. Because the structure of the novel compounds is known, our understanding of the relationship of bismuth compound structure and to biologic activity will increase. In the future it may be possible to design other novel bismuth compounds with more potent anti-H. pylori and ulcer healing effects.

Thermoelectric Performance Enhancement by Surrounding Crystalline Semiconductors with Metallic Nanoparticles

NASA Technical Reports Server (NTRS)

Kim, Hyun-Jung; King, Glen C.; Park, Yeonjoon; Lee, Kunik; Choi, Sang H.

2011-01-01

Direct conversion of thermal energy to electricity by thermoelectric (TE) devices may play a key role in future energy production and utilization. However, relatively poor performance of current TE materials has slowed development of new energy conversion applications. Recent reports have shown that the dimensionless Figure of Merit, ZT, for TE devices can be increased beyond the state-of-the-art level by nanoscale structuring of materials to reduce their thermal conductivity. New morphologically designed TE materials have been fabricated at the NASA Langley Research Center, and their characterization is underway. These newly designed materials are based on semiconductor crystal grains whose surfaces are surrounded by metallic nanoparticles. The nanoscale particles are used to tailor the thermal and electrical conduction properties for TE applications by altering the phonon and electron transport pathways. A sample of bismuth telluride decorated with metallic nanoparticles showed less thermal conductivity and twice the electrical conductivity at room temperature as compared to pure Bi2Te3. Apparently, electrons cross easily between semiconductor crystal grains via the intervening metallic nanoparticle bridges, but phonons are scattered at the interfacing gaps. Hence, if the interfacing gap is larger than the mean free path of the phonon, thermal energy transmission from one grain to others is reduced. Here we describe the design and analysis of these new materials that offer substantial improvements in thermoelectric performance.

Mineral resource of the month: bismuth

USGS Publications Warehouse

Carlin, James F.

2006-01-01

Bismuth compounds are most known for their soothing effects on the stomach, wounds and sores. These properties make the compounds an essential part of many medicinal and cosmetic preparations, which until 1930 accounted for about 90 percent of the bismuth used. The subsequent development of low-melting alloys and chemical catalysts containing bismuth, as well as its use as an additive to casting alloys, has resulted in a wider variety of industrial applications for bismuth.

PREVENTION REFERENCE MANUAL: CHEMICAL SPECIFIC. VOL. 15: CONTROL OF ACCIDENTAL RELEASES OF SULFUR TRIOXIDE

EPA Science Inventory

The report, discussing sulfur trioxide (SO3), is one of a series addressing the prevention of accidental releases of toxic chemicals. SO3, a clear oily liquid or solid at typical ambient conditions, has an Immediately Dangerous to Life and Health (IDLH) concentration of 20 ppm, w...

Contribution to the photometric determination of small amounts of boron trioxide in glasses

NASA Technical Reports Server (NTRS)

Markova, D.

1985-01-01

The photometric determination for boron trioxide is described in amounts of 0-75 micrograms B2O3 with an azomethin H reagent. The yellow colored complex which occurs in a medium held at a pH of 4.5 was measured in light of a wavelength of 415 nm.

Arsenic trioxide-induced osteo-necrosis treatment in a child: mini-review and case report.

PubMed

Marty, M; Noirrit-Esclassan, E; Diemer, F

2016-10-01

Arsenic oxide compounds were traditionally used as devitalizing agents. Due to its toxicity, leakage of such compounds into the periodontium can cause gingival and osteo-necrosis. Their use is forbidden in Europe and the USA for decades, however, some dentists seem to still use it. We report the case of a 14-year-old girl referred to the paediatric dentistry department of Toulouse University hospital, France, presenting a bone necrosis following the use of an arsenic trioxide product to accelerate pulp necrosis. The treatment included surgical removal of necrosis bone sequestrum, complete pulpectomy and an intermediate restoration of the tooth 27. After 1 week, the clinical conditions greatly improved. A restoration using a ceramic crown was performed after 2 months, and complete healing was observed after 1 year follow-up. Although arsenic trioxide is neither appropriate nor permitted for use in modern dentistry, especially in paediatric dentistry, some rare cases of arsenic-induced osteo-necrosis can still be encountered. A clearer message must be given to all dental practitioners against the use of arsenic trioxide in modern endodontic treatment.

Template-free fabrication of hierarchically flower-like tungsten trioxide assemblies with enhanced visible-light-driven photocatalytic activity.

PubMed

Yu, Jiaguo; Qi, Lifang

2009-09-30

Hierarchically flower-like tungsten trioxide assemblies were fabricated on a large scale by a simple hydrothermal treatment of sodium tungstate in aqueous solution of nitric acid. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy and N(2) adsorption-desorption measurements. The photocatalytic activity was evaluated by photocatalytic decolorization of rhodamine B aqueous solution under visible-light irradiation. It was found that the three-dimensional tungsten trioxide assemblies were constructed from two-dimensional layers, which were further composed of a large number of interconnected lathy nanoplates with different sizes. Such flower-like assemblies exhibited hierarchically porous structure and higher visible-light photocatalytic activity than the samples without such hierarchical structures due to their specific hierarchical pores that served as the transport paths for light and reactants. After five recycles for the photodegradation of RhB, the catalyst did not exhibit any great loss in activity, confirming hierarchically flower-like tungsten trioxide was stability and not photocorroded. This study may provide new insight into environmentally benign preparation and design of novel photocatalytic materials and enhancement of photocatalytic activity.

Effect of bismuth subcitrate on amphibian gastroduodenal bicarbonate secretion.

PubMed Central

Shorrock, C J; Crampton, J R; Gibbons, L C; Rees, W D

1989-01-01

The ulcer healing and cytoprotective properties of colloidal bismuth (De-Nol) are well established although its mode of action is unclear. We have examined the action of bismuth subcitrate, the active ingredient of De-Nol, on gastroduodenal bicarbonate secretion by isolated amphibian mucosa. Addition of bismuth subcitrate (10(-6) to 10(-4) M) to the luminal solution produced a dose dependent increase in bicarbonate secretion from both gastric and duodenal mucosae without a change in transmucosal potential difference. The magnitude of this stimulation was greater for gastric than duodenal mucosae at all dose ranges. A second bismuth salt, bismuth oxynitrate, produced similar increases in bicarbonate secretion from gastric mucosae. Pretreatment of gastric mucosa with the cyclooxygenase inhibitor, indomethacin (10(-5) and 10(-4) M), did not abolish the secretory response to bismuth subcitrate. Similar treatment with the chloride transport inhibitor, 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid (SITS) (10(-3) M) prevented the secretory response to bismuth subcitrate. PMID:2788112

Development of a hybrid paclitaxel-loaded arsenite nanoparticle (HPAN) delivery system for synergistic combined therapy of paclitaxel-resistant cancer

NASA Astrophysics Data System (ADS)

Chen, Fei-yan; Zhang, Yu; Chen, Xiang-yu; Li, Jia-qian; Xiao, Xiao-ping; Yu, Lu-lu; Tang, Qun

2017-04-01

Multidrug resistance (MDR) is a major reason for failure of chemotherapy in a variety of human tumors. For instance, paclitaxel (PTX) has been widely used as a first-line anticancer drug, but resistance to PTX is becoming increasingly serious. Herein, we propose a strategy of combined therapy to overcome MDR of PTX by introducing a hybrid paclitaxel-loaded gadolinium arsenite nanoparticle (HPAN), where PTX was conjugated with rod-shaped gadolinium arsenite (GdAsOx) nanoparticle (NP). Triggered by endogenous inorganic phosphate (Pi), the hybrid nanoparticles readily collapse, thereby releasing PTX and arsenic trioxide (ATO). An MTT assay indicated IC50 values for HPAN one order of magnitude lower than for a simple equivalent mixture of PTX and ATO against PTX-resistant human colon cancer cells (HCT 166), indicating remarkable synergistic effect. Species type-dependent cellular uptake, induced apoptosis, and cell cycle modulation were also evaluated. Cellular uptake tests indicate that the HPAN presents higher PTX intracellular loading for the PTX-resistant cells and longer intracellular retention time, displaying resistance to drug efflux from the cancer cell than pristine PTX or the equivalent mixture of PTX and ATO. Cell cycle and apoptosis tests consistently proved that addition of HPAN resulted in higher G2/M and apoptosis in PTX-resistant cells. In vivo anticancer experiments evidenced that HPAN had better therapeutic effect on the resistant tumor in the murine xenograft model than pristine PTX or a mixture of PTX and ATO. Our results suggest that HPAN might enhance the therapeutic index and overcome PTX resistance and also demonstrate that the combined therapy is not only related to the species of combined agents but also their physiochemical states.

PROCESS OF COATING METALS WITH BISMUTH OR BISMUTH-BASE ALLOYS

DOEpatents

Beach, J.G.

1958-01-28

A method is described for producing coatings of bismuth or bismuth alloys on a metal base. This is accomplished by electrodepositing the bismuth from an aqueous solution of BiCl/sub 3/, and by making the metal base alternately the cathode and the anode, the cathode periods being twice as long as the anode periods. In one embodiment a nickel coating is first electrodeposited in a known way, and this nickel plated piece is tae base upon which tae bismuth is deposited by the process of this patent. The coated piece is then heat treated to produce a homogeneous Ni--Bi alloy by diffusion.

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to...

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to...

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to waters of the...

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to...

40 CFR 471.10 - Applicability; description of the lead-tin-bismuth forming subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-tin-bismuth forming subcategory. 471.10 Section 471.10 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.10 Applicability; description of the lead-tin-bismuth forming subcategory. This subpart applies to discharges of pollutants to waters of the...

BISMUTH PHOSPHATE CARRIER PROCESS FOR Pu RECOVERY

DOEpatents

Finzel, T.G.

1959-02-01

An improvement in the bismuth phosphate carrier precipitation process for recovering plutonium is described. It has been found that a more granular and more easily filterable carrier precipitiite is formed if the addition of the bismuth and phosphate ions is effected by first adding 9/10 of the bismuth ions necessary, then slowly adding all of the source of the phosphate ions to be incorporated in the precipitate, while digesting at 75 C and afterwards incorporating the remainder of the total bismuth ions necessary

Highly spatially resolved structural and optical investigation of Bi nanoparticles in Y-Er disilicate thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scarangella, A.; Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania; Amiard, G.

2016-08-08

Er-containing silicon compatible materials have been widely used as infrared emitters for microphotonics application. In this field, the additional introduction of a proper sensitizer permits to increase the Er excitation cross sections, thus increasing its optical efficiency. This work aims to investigate the influence of a post-transition metal, bismuth, on the optical properties of erbium-yttrium disilicate thin films synthesized by magnetron co-sputtering. After thermal treatments at 1000 °C in O{sub 2} or N{sub 2} environment, the presence of small precipitates, about 6 nm in diameter, was evidenced by transmission electron microscopy analyses. The spatially resolved chemical nature of the nanoparticles was discernedmore » in the Si and O rich environments by means of scanning transmission electron microscopy–energy dispersive X-ray and scanning transmission electron microscopy–electron energy loss spectroscopy analyses performed with nanometric resolution. In particular, metallic Bi nanoparticles were stabilized in the N{sub 2} environment, being strongly detrimental for the Er emission. A different scenario was instead observed in O{sub 2}, where the formation of Bi silicate nanoparticles was demonstrated with the support of photoluminescence excitation spectroscopy. In particular, a broad band peaked at 255 nm, correlated to the excitation band of Bi silicate nanoparticles, was identified in Er excitation spectrum. Thus Bi silicate clusters act as sensitizer for Er ions, permitting to improve Er emission up to 250 times with respect to the resonant condition. Moreover, the Er decay time increases in the presence of the Bi silicate nanoparticles that act as cages for Er ions. These last results permit to further increase Er optical efficiency in the infrared range, suggesting (Bi + Er)-Y disilicate as a good candidate for applications in microphotonics.« less

Bursting at the Seams: Rippled Monolayer Bismuth on NbSe 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Alan; Adamo, Carolina; Jia, Shuang

Bismuth, one of the heaviest semimetals in nature, ignited the interest of the materials-physics community for its potential impact on topological quantum-material systems that utilize its strong spin-orbit coupling (SOC) and unique orbital hybridization. In particular, recent theoretical predictions of unique topological and superconducting properties of thin bismuth films and interfaces prompted intense research on the growth of sub- to a few monolayers of bismuth on different substrates. Similar to bulk rhombohedral bismuth, the initial growth of bismuth films on most substrates results in buckled bilayers that either grow in the (111) or (110) directions, with a lattice constant closemore » to that of bulk Bi. By contrast, in this paper we show a new growth pattern for bismuth monolayers on NbSe 2. We find that the initial growth of Bi can form a strongly bonded commensurate layer, resulting in a compressively strained two-dimensional triangular lattice. A unique pattern of 1D ripples and domain walls is observed. The single layer of bismuth also introduces strong marks on the electronic properties at the surface.« less

Bursting at the Seams: Rippled Monolayer Bismuth on NbSe 2

DOE PAGES

Fang, Alan; Adamo, Carolina; Jia, Shuang; ...

2018-04-13

Bismuth, one of the heaviest semimetals in nature, ignited the interest of the materials-physics community for its potential impact on topological quantum-material systems that utilize its strong spin-orbit coupling (SOC) and unique orbital hybridization. In particular, recent theoretical predictions of unique topological and superconducting properties of thin bismuth films and interfaces prompted intense research on the growth of sub- to a few monolayers of bismuth on different substrates. Similar to bulk rhombohedral bismuth, the initial growth of bismuth films on most substrates results in buckled bilayers that either grow in the (111) or (110) directions, with a lattice constant closemore » to that of bulk Bi. By contrast, in this paper we show a new growth pattern for bismuth monolayers on NbSe 2. We find that the initial growth of Bi can form a strongly bonded commensurate layer, resulting in a compressively strained two-dimensional triangular lattice. A unique pattern of 1D ripples and domain walls is observed. The single layer of bismuth also introduces strong marks on the electronic properties at the surface.« less

Bioavailability and chronic toxicity of bismuth citrate to earthworm Eisenia andrei exposed to natural sandy soil.

PubMed

Omouri, Zohra; Hawari, Jalal; Fournier, Michel; Robidoux, Pierre Yves

2018-01-01

The present study describes bioavailability and chronic effects of bismuth to earthworms Eisenia andrei using OECD reproduction test. Adult earthworms were exposed to natural sandy soil contaminated artificially by bismuth citrate. Average total concentrations of bismuth in soil recovered by HNO 3 digestion ranged from 75 to 289mg/kg. Results indicate that bismuth decreased significantly all reproduction parameters of Eisenia andrei at concentrations ≥ 116mg/kg. However, number of hatched cocoons and number of juveniles seem to be more sensitive than total number of cocoons, as determined by IC 50 ; i.e., 182, 123 and > 289mg/kg, respectively. Bismuth did not affect Eisenia andrei growth and survival, and had little effect on phagocytic efficiency of coelomocytes. The low immunotoxicity effect might be explained by the involvement of other mechanisms i.e. bismuth sequestered by metal-binding compounds. After 28 days of exposure bismuth concentrations in earthworms tissue increased with increasing bismuth concentrations in soil reaching a stationary state of 21.37mg/kg dry tissue for 243mg Bi/kg dry soil total content. Data indicate also that after 56 days of incubation the average fractions of bismuth available extracted by KNO 3 aqueous solution in soil without earthworms varied from 0.0051 to 0.0229mg/kg, while in soil with earthworms bismuth concentration ranged between 0.310-1.347mg/kg dry soil. We presume that mucus and chelating agents produced by earthworms and by soil or/and earthworm gut microorganisms could explain this enhancement, as well as the role of dermal and ingestion routes of earthworms uptake to soil contaminant. Copyright © 2017 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biasotto, G.; Simoes, A.Z., E-mail: alezipo@yahoo.com; Foschini, C.R.

Highlights: Black-Right-Pointing-Pointer BiFeO{sub 3} (BFO) nanoparticles were grown by hydrothermal microwave method (HTMW). Black-Right-Pointing-Pointer The soaking time is effective in improving phase formation. Black-Right-Pointing-Pointer Rietveld refinement reveals an orthorhombic structure. Black-Right-Pointing-Pointer The observed magnetism of the BFO crystallites is a consequence of particle size. Black-Right-Pointing-Pointer The HTMW is a genuine technique for low temperatures and short times of synthesis. -- Abstract: Hydrothermal microwave method (HTMW) was used to synthesize crystalline bismuth ferrite (BiFeO{sub 3}) nanoparticles (BFO) in the temperature of 180 Degree-Sign C with times ranging from 5 min to 1 h. BFO nanoparticles were characterized by means of X-raymore » analyses, FT-IR, Raman spectroscopy, TG-DTA and FE-SEM. X-ray diffraction results indicated that longer soaking time was benefit to refraining the formation of any impurity phases and growing BFO crystallites into almost single-phase perovskites. Typical FT-IR spectra for BFO nanoparticles presented well defined bands, indicating a substantial short-range order in the system. TG-DTA analyses confirmed the presence of lattice OH{sup -} groups, commonly found in materials obtained by HTMW process. Compared with the conventional solid-state reaction process, submicron BFO crystallites with better homogeneity could be produced at the temperature as low as 180 Degree-Sign C. These results show that the HTMW synthesis route is rapid, cost effective, and could be used as an alternative to obtain BFO nanoparticles in the temperature of 180 Degree-Sign C for 1 h.« less

Gravimetric Analysis of Bismuth in Bismuth Subsalicylate Tablets: A Versatile Quantitative Experiment for Undergraduate Laboratories

ERIC Educational Resources Information Center

Davis, Eric; Cheung, Ken; Pauls, Steve; Dick, Jonathan; Roth, Elijah; Zalewski, Nicole; Veldhuizen, Christopher; Coeler, Joel

2015-01-01

In this laboratory experiment, lower- and upper-division students dissolved bismuth subsalicylate tablets in acid and precipitated the resultant Bi[superscript 3+] in solution with sodium phosphate for a gravimetric determination of bismuth subsalicylate in the tablets. With a labeled concentration of 262 mg/tablet, the combined data from three…

Hydrothermal synthesis of bismuth germanium oxide

DOEpatents

Boyle, Timothy J.

2016-12-13

A method for the hydrothermal synthesis of bismuth germanium oxide comprises dissolving a bismuth precursor (e.g., bismuth nitrate pentahydrate) and a germanium precursor (e.g., germanium dioxide) in water and heating the aqueous solution to an elevated reaction temperature for a length of time sufficient to produce the eulytite phase of bismuth germanium oxide (E-BGO) with high yield. The E-BGO produced can be used as a scintillator material. For example, the air stability and radioluminescence response suggest that the E-BGO can be employed for medical applications.

Bismuth, Metronidazole, and Tetracycline

MedlinePlus

Helidac® (as a kit containing Bismuth Subsalicylate, Metronidazole, Tetracycline) ... Bismuth, metronidazole, and tetracycline is used along with other ulcer medications to treat duodenal ulcers. It is in a ...

Thermodynamics Calculation and Experimental Study on Separation of Bismuth from a Bismuth Glance Concentrate Through a Low-Temperature Molten Salt Smelting Process

NASA Astrophysics Data System (ADS)

Yang, Jian-Guang; He, De-Wen; Tang, Chao-Bo; Chen, Yong-Ming; Sun, Ya-Hui; Tang, Mo-Tang

2011-08-01

The main purpose of this study is to characterize and separate bismuth from a bismuth glance concentrate through a low-temperature, sulfur-fixing smelting process. This article reports on a study conducted on the optimization of process parameters, such as Na2CO3 and zinc oxide wt pct in charging, smelting temperature, smelting duration on the bismuth yield, resultant crude bismuth grade, and sulfur-fixing rate. A maximum bismuth recovery of 97.31 pct, crude bismuth grade of 96.93 pct, and 98.23 pct sulfur-fixing rate are obtained when a charge (containing 63.50 wt pct of Na2CO3 and 22.50 wt pct of bismuth glance, as well as 5 pct in excess of the stoichiometric requirement of zinc oxide dosage) is smelted at 1000 K (727 °C) for 150 minutes. This smelting operation is free from atmospheric pollution because zinc oxide is used as the sulfur-fixing agent, which can capture sulfur from bismuth sulfide and form the more thermodynamic-stable compound, zinc sulfide. The solid residue is subjected to a mineral dressing operation to obtain suspension, which is filtered to produce a cake, representing the solid particles of zinc sulfide. Based on the results of the chemical content analysis of the as-resultant zinc sulfide, more than 93 pct zinc sulfide can be recovered, and the recovered zinc sulfide grade can reach 60.20 pct. This material can be sold as zinc sulfide concentrate or roasted to be regenerated as zinc oxide.

Glutathione and multidrug resistance protein transporter mediate a self-propelled disposal of bismuth in human cells

PubMed Central

Hong, Yifan; Lai, Yau-Tsz; Chan, Godfrey Chi-Fung; Sun, Hongzhe

2015-01-01

Glutathione and multidrug resistance protein (MRP) play an important role on the metabolism of a variety of drugs. Bismuth drugs have been used to treat gastrointestinal disorder and Helicobacter pylori infection for decades without exerting acute toxicity. They were found to interact with a wide variety of biomolecules, but the major metabolic pathway remains unknown. For the first time (to our knowledge), we systematically and quantitatively studied the metabolism of bismuth in human cells. Our data demonstrated that over 90% of bismuth was passively absorbed, conjugated to glutathione, and transported into vesicles by MRP transporter. Mathematical modeling of the system reveals an interesting phenomenon. Passively absorbed bismuth consumes intracellular glutathione, which therefore activates de novo biosynthesis of glutathione. Reciprocally, sequestration by glutathione facilitates the passive uptake of bismuth and thus completes a self-sustaining positive feedback circle. This mechanism robustly removes bismuth from both intra- and extracellular space, protecting critical systems of human body from acute toxicity. It elucidates the selectivity of bismuth drugs between human and pathogens that lack of glutathione, such as Helicobacter pylori, opening new horizons for further drug development. PMID:25737551

Intense 2.7 µm emission and structural origin in Er3+-doped bismuthate (Bi2O3-GeO2-Ga2O3-Na2O) glass.

PubMed

Guo, Yanyan; Li, Ming; Hu, Lili; Zhang, Junjie

2012-01-15

The 2.7 μm emission properties in Er3+-doped bismuthate (Bi2O3-GeO2-Ga2O3-Na2O) glass were investigated in the present Letter. An intense 2.7 μm emission in Er3+-doped bismuthate glass was observed. It is found that Er3+-doped bismuthate glass possesses high spontaneous transition probability A (65.26 s(-1)) and large 2.7 μm emission cross section σ(em) (9.53×10(-21) cm2) corresponding to the stimulated emission of Er3+:4I11/2→4I13/2 transition. The emission characteristic and energy transfer process upon excitation of a conventional 980 nm laser diode in bismuthate glass were analyzed. Additionally, the structure of bismuthate glass was analyzed by the Raman spectrum. The advantageous spectroscopic characteristics of Er3+ single-doped bismuthate glass together with the prominent thermal property indicate that bismuthate glass might become an attractive host for developing solid-state lasers around 2.7 μm.

Controlled release of lovastatin from poly(lactic-co-glycolic acid) nanoparticles for direct pulp capping in rat teeth.

PubMed

Lin, Hung-Pin; Tu, Han-Ping; Hsieh, Yu-Ping; Lee, Bor-Shiunn

2017-01-01

Statin at appropriate concentrations has been shown to induce odontoblastic differentiation, dentinogenesis, and angiogenesis. However, using a carrier to control statin release might reduce toxicity and enhance its therapeutic effects. The aim of this study was to prepare poly(d,l-lactide- co -glycolide acid) (PLGA) nanoparticles that contain lovastatin for application in direct pulp capping. The PLGA-lovastatin particle size was determined using dynamic light scattering measurements and transmission electron microscopy. In addition, the release of lovastatin was quantified using a UV-Vis spectrophotometer. The cytotoxicity and alkaline phosphatase (ALP) activity of PLGA-lovastatin nanoparticles on human dental pulp cells were investigated. Moreover, a real-time polymerase chain reaction (PCR) assay, Western blot analysis, and an enzyme-linked immunosorbent assay (ELISA) were used to examine the osteogenesis gene and protein expression of dentin sialophosphoprotein (DSPP), dentin matrix acidic phosphoprotein 1 (DMP1), and osteocalcin (OCN). Finally, PLGA-lovastatin nanoparticles and mineral trioxide aggregate (MTA) were compared as direct pulp capping materials in Wistar rat teeth. The results showed that the median diameter of PLGA-lovastatin nanoparticles was 174.8 nm and the cumulative lovastatin release was 92% at the 44th day. PLGA-lovastatin nanoparticles demonstrated considerably a lower cytotoxicity than free lovastatin at 5, 9, and 13 days of culture. For ALP activity, the ALP amount of PLGA-lovastatin (100 μg/mL) was significantly higher than that of the other groups for 9 and 13 days of culture. The real-time PCR assay, Western blot analysis, and ELISA assay showed that PLGA-lovastatin (100 μg/mL) induced the highest mRNA and protein expression of DSPP, DMP1, and OCN in pulp cells. Histological evaluation of the animal studies revealed that MTA was superior to the PLGA-lovastatin in stimulating the formation of tubular dentin in an observation period of 2 weeks. However, in an observation period of 4 weeks, it was evident that the PLGA-lovastatin and MTA were competitive in the formation of tubular reparative dentin and a complete dentinal bridge.

Cytotoxicity and Bioactivity of Calcium Silicate Cements Combined with Niobium Oxide in Different Cell Lines.

PubMed

Mestieri, Leticia Boldrin; Gomes-Cornélio, Ana Lívia; Rodrigues, Elisandra Márcia; Faria, Gisele; Guerreiro-Tanomaru, Juliane Maria; Tanomaru-Filho, Mário

2017-01-01

The aim of this study was to evaluate the cytotoxicity and bioactivity of calcium silicate-based cements combined with niobium oxide (Nb2O5) micro and nanoparticles, comparing the response in different cell lines. This evaluation used four cell lines: two primary cultures (human dental pulp cells - hDPCs and human dental follicle cells - hDFCs) and two immortalized cultures (human osteoblast-like cells - Saos-2 and mouse periodontal ligament cells - mPDL). The tested materials were: White Portland Cement (PC), mineral trioxide aggregate (MTA), white Portland cement combined with microparticles (PC/Nb2O5µ) or nanoparticles (PC/Nb2O5n) of niobium oxide (Nb2O5). Cytotoxicity was evaluated by the methylthiazolyldiphenyl-tetrazolium bromide (MTT) and trypan blue exclusion assays and bioactivity by alkaline phosphatase (ALP) enzyme activity. Results were analyzed by ANOVA and Tukey test (a=0.05). PC/Nb2O5n presented similar or higher cell viability than PC/Nb2O5µ in all cell lines. Moreover, the materials presented similar or higher cell viability than MTA. Saos-2 exhibited high ALP activity, highlighting PC/Nb2O5µ material at 7 days of exposure. In conclusion, calcium silicate cements combined with micro and nanoparticles of Nb2O5 presented cytocompatibility and bioactivity, demonstrating the potential of Nb2O5 as an alternative radiopacifier agent for these cements. The different cell lines had similar response to cytotoxicity evaluation of calcium silicate cements. However, bioactivity was more accurately detected in human osteoblast-like cell line, Saos-2.

The Effects of Bismuth Oxide on Microstructures and Magnetic Properties of Mn-Mg-Al Ferrites

NASA Astrophysics Data System (ADS)

Nekouee, Kh. A.; Rahimi, A. H.; Haghighi, M. Alineghad; Ehsani, N.

2018-04-01

In the present paper, the effects of bismuth oxide as an additive on microstructure and magnetic properties of Mg0.9Mn0.1Al0.4Fe1.6O4 were investigated. Mg-Mn-Al ferrite powders were prepared by the conventional solid state synthesis method. Two different amounts of bismuth oxide (2.5 wt.% and 5 wt.%) were utilized as the sintering aid and their microstructure and physical properties were compared to those of the sample without additives. X-ray diffraction (XRD) analysis indicated that crystal lattice distortion due to the microstructural constraints as the result from incorporation of bismuth oxide into the microstructure was developed by adding bismuth oxide. XRD Rietveld refinement was used to define the cation distribution and to refine the lattice parameter and oxygen parameter for the sample without bismuth oxide as (Mg0.16Mn0.02Al0.15Fe0.77)A(Mg0.74Mn0.08Al0.25Fe0.83)BO4 and 8.3308 Å and 0.2542, respectively. Microstructure studies show that a bismuth rich liquid phase forms during the sintering at 1250°C, which enhances the densification of sintered bodies up to 13% (a relative density of 93%). Magnetization of sintered samples were increased from 21.1 emu/g to 26.2 emu/g upon addition of 2.5 wt.% bismuth oxide and then decreased to 24.9 emu/g when 5 wt.% bismuth oxide was added.

Flexible neutron shielding composite material of EPDM rubber with boron trioxide: Mechanical, thermal investigations and neutron shielding tests

NASA Astrophysics Data System (ADS)

Özdemir, T.; Güngör, A.; Reyhancan, İ. A.

2017-02-01

In this study, EPDM and boron trioxide composite was produced and mechanical, thermal and neutron shielding tests were performed. EPDM rubber (Ethylene Propylene Diene Monomer) having a considerably high hydrogen content is an effective neutron shielding material. On the other hand, the materials containing boron components have effective thermal neutron absorption crossection. The composite of EPDM and boron trioxide would be an effective solution for both respects of flexibility and effectiveness for developing a neutron shielding material. Flexible nature of EPDM would be a great asset for the shielding purpose in case of intervention action to a radiation accident. The theoretical calculations and experimental neutron absorption tests have shown that the results were in parallel and an effective neutron shielding has been achieved with the use of the developed composite material.

Formation of self-ordered porous anodized alumina template for growing tungsten trioxide nanowires

NASA Astrophysics Data System (ADS)

Hussain, Tajamal; Shah, Asma Tufail; Shehzad, Khurram; Mujahid, Adnan; Farooqi, Zahoor Hussain; Raza, Muhammad Hamid; Ahmed, Mirza Nadeem; Nisa, Zaib Un

2015-12-01

Uniform porous anodized aluminum oxide (AAO) membrane has been synthesized by two-step anodization for fabricating tungsten trioxide (WO3) nanowires. Under assayed conditions, uniform porous structure of alumina (Al2O3) membrane with long range ordered hexagonal arrangements of nanopores was achieved. The self-assembled template possesses pores of internal diameter of 50 nm and interpore distance ( d int) of 80 nm with a thickness of about 80 µm, i.e., used for fabrication of nanostructures. WO3 nanowires have been fabricated by simple electroless deposition method inside Al2O3 nanopores. SEM images show tungsten trioxide nanowire with internal diameter of about 50 nm, similar to porous diameter of AAO template. XRD results showed that nanowires exist in cubic crystalline state with minor proportion of monoclinic phase.

Structural, electronic, vibrational and optical properties of Bin clusters

NASA Astrophysics Data System (ADS)

Liang, Dan; Shen, Wanting; Zhang, Chunfang; Lu, Pengfei; Wang, Shumin

2017-10-01

The neutral, anionic and cationic bismuth clusters with the size n up to 14 are investigated by using B3LYP functional within the regime of density functional theory and the LAN2DZ basis set. By analysis of the geometries of the Bin (n = 2-14) clusters, where cationic and anionic bismuth clusters are largely similar to those of neutral ones, a periodic effect by adding units with one to four atoms into smaller cluster to form larger cluster is drawn for the stable structures of bismuth clusters. An even-odd alteration is shown for the properties of the clusters, such as the calculated binding energies and dissociation energies, as well as frontier orbital energies, electron affinities, ionization energies. All the properties indicate that the Bi4 cluster is the most possible existence in bismuth-containing materials, which supports the most recent experiment. The orbital compositions, infrared and Raman activities and the ultraviolet absorption of the most possible tetramer bismuth cluster are given in detail to reveal the periodic tendency of adding bismuth atoms and the stability of tetramer bismuth cluster.

Extreme Pressure Synergistic Mechanism of Bismuth Naphthenate and Sulfurized Isobutene Additives

NASA Astrophysics Data System (ADS)

Xu, Xin; Hu, Jianqiang; Yang, Shizhao; Xie, Feng; Guo, Li

A four-ball tester was used to evaluate the tribological performances of bismuth naphthenate (BiNap), sulfurized isobutene (VSB), and their combinations. The results show that the antiwear properties of BiNap and VSB are not very visible, but they possess good extreme pressure (EP) properties, particularly sulfur containing bismuth additives. Synergistic EP properties of BiNap with various sulfur-containing additives were investigated. The results indicate that BiNap exhibits good EP synergism with sulfur-containing additives. The surface analytical tools, such as X-ray photoelectron spectrometer (XPS) scanning electron microscope (SEM) and energy dispersive X-ray (EDX), were used to investigate the topography, composition contents, and depth profile of some typical elements on the rubbing surface. Smooth topography of wear scar further confirms that the additive showed good EP capacities, and XPS and EDX analyzes indicate that tribochemical mixed protective films composed of bismuth, bismuth oxides, sulfides, and sulfates are formed on the rubbing surface, which improves the tribological properties of lubricants. In particular, a large number of bismuth atoms and bismuth sulfides play an important role in improving the EP properties of oils.

Bismuth Nanoparticles Embedded in Carbon Spheres as Anode Materials for Sodium/Lithium-Ion Batteries.

PubMed

Yang, Fuhua; Yu, Fan; Zhang, Zhian; Zhang, Kai; Lai, Yanqing; Li, Jie

2016-02-12

Sodium-ion batteries (SIBs) are regarded as an attractive alternative to lithium-ion batteries (LIBs) for large-scale commercial applications, because of the abundant terrestrial reserves of sodium. Exporting suitable anode materials is the key to the development of SIBs and LIBs. In this contribution, we report on the fabrication of Bi@C microspheres using aerosol spray pyrolysis technique. When used as SIBs anode materials, the Bi@C microsphere delivered a high capacity of 123.5 mAh g(-1) after 100 cycles at 100 mA g(-1) . The rate performance is also impressive (specific capacities of 299, 252, 192, 141, and 90 mAh g(-1) are obtained under current densities of 0.1, 0.2, 0.5, 1, and 2 A g(-1) , respectively). Furthermore, the Bi@C microsphere also proved to be suitable LIB anode materials. The excellent electrochemical performance for both SIBs and LIBs can attributed to the Bi@C microsphere structure with Bi nanoparticles uniformly dispersed in carbon spheres. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improvement of magnetic and ferroelectric properties of BiFeO{sub 3} nanoparticles on Tb and Co substitution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, A.; De, S.; Chatterjee, S.

2016-05-06

Tb and Co substituted bismuth ferrite nanoparticles (NPs) with chemical composition Bi{sub 1-x}Tb{sub x}Fe{sub 1-y}Co{sub y}O{sub 3} (x = 0, 0.05; y = 0, 0.05) have been synthesized by a sol-gel method and characterized by x-ray diffraction (XRD), Mossbauer spectroscopy, dc magnetization and electric polarization measurements. The aim of the present work is to improve ferroelectric properties of BiFeO{sub 3} by substitution of Tb{sup 3+} ions in Bi{sup 3+} site and magnetic properties by substitution of Co{sup 2+} in Fe{sup 3+} site. The XRD patterns of all prepared samples show formation of the desired phase along with a small amountmore » of impurity. Room temperature Mossbauer spectroscopic studies reveal that all samples are in magnetically ordered state. Magnetic hysteresis loops of all samples indicate a significant enhancement of magnetic moment and coercivity whereas electric polarization measurements at room temperature reveal an improvement of ferroelectric properties in the co-substituted sample.« less

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

NASA Astrophysics Data System (ADS)

Yan, Daikang; Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; Madden, Timothy J.; Miceli, Antonino; Park, Jun-Sang; Patel, Umeshkumar M.; Quaranta, Orlando; Sharma, Hemant; Bennett, Douglas A.; Doriese, William B.; Fowler, Joseph W.; Gard, Johnathon D.; Hays-Wehle, James P.; Morgan, Kelsey M.; Schmidt, Daniel R.; Swetz, Daniel S.; Ullom, Joel N.

2017-11-01

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth, and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. We show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

DOE PAGES

Divan, Ralu; Gades, Lisa M.; Kenesei, Peter; ...

2017-11-08

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth,more » and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. Lastly, we show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.« less

Eliminating the non-Gaussian spectral response of X-ray absorbers for transition-edge sensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Divan, Ralu; Gades, Lisa M.; Kenesei, Peter

Transition-edge sensors (TESs) as microcalorimeters for high-energy-resolution X-ray spectroscopy are often fabricated with an absorber made of materials with high Z (for X-ray stopping power) and low heat capacity (for high resolving power). Bismuth represents one of the most compelling options. TESs with evaporated bismuth absorbers have shown spectra with undesirable and unexplained low-energy tails. We have developed TESs with electroplated bismuth absorbers over a gold layer that are not afflicted by this problem and that retain the other positive aspects of this material. To better understand these phenomena, we have studied a series of TESs with gold, gold/evaporated bismuth,more » and gold/electroplated bismuth absorbers, fabricated on the same die with identical thermal coupling. Lastly, we show that the bismuth morphology is linked to the spectral response of X-ray TES microcalorimeters.« less

Localization and Related Phenomena in Multiply Connected Nanostructured Inverse Opal Bismuth

NASA Astrophysics Data System (ADS)

Bleiweiss, Michael; Saygi, Salih; Amirzadeh, Jafar; Datta, Timir; Lungu, Anca; Yin, Ming; Palm, Eric; Brandt, Bruce; Iqbal, Zafar

2001-03-01

The nanostructures were fabricated by pressure infiltration of bismuth into porous artificial opal and were characterized using SEM, EDX and XRD. These structures form a regular three-dimensional network in which the bismuth regions percolate in all directions between the close packed spheres of SiO_2. The sizes of the conducting regions are of the order of tens of nanometers. The static magnetic properties of both bismuth inverse opal and bulk bismuth were studied using a SQUID magnetometer. Transport measurements, including Hall, were done using standard ac four and six probe techniques in fields up to 17 T* and temperatures between 4.2 and 150 K. The results of these measurements, including the observation of localization phenomena, will be discussed. Comparisons will be made with published results on bismuth nanowires. *Performed at the National High Magnetic Field Lab (NHMFL) FSU, Tallahassee, FL. Partially supported by a grant from NASA.

Recent Advances in Bismuth-Based Nanomaterials for Photoelectrochemical Water Splitting.

PubMed

Bhat, Swetha S M; Jang, Ho Won

2017-08-10

In recent years, bismuth-based nanomaterials have drawn considerable interest as potential candidates for photoelectrochemical (PEC) water splitting owing to their narrow band gaps, nontoxicity, and low costs. The unique electronic structure of bismuth-based materials with a well-dispersed valence band comprising Bi 6s and O 2p orbitals offers a suitable band gap to harvest visible light. This Review presents significant advancements in exploiting bismuth-based nanomaterials for solar water splitting. An overview of the different strategies employed and the new ideas adopted to improve the PEC performance of bismuth-based nanomaterials are discussed. Morphology control, the construction of heterojunctions, doping, and co-catalyst loading are several approaches that are implemented to improve the efficiency of solar water splitting. Key issues are identified and guidelines are suggested to rationalize the design of efficient bismuth-based materials for sunlight-driven water splitting. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of paper-based electrochemical sensors for water quality monitoring

NASA Astrophysics Data System (ADS)

Smith, Suzanne; Bezuidenhout, Petroné; Mbanjwa, Mesuli; Zheng, Haitao; Conning, Mariette; Palaniyandy, Nithyadharseni; Ozoemena, Kenneth; Land, Kevin

2016-02-01

We present a method for the development of paper-based electrochemical sensors for detection of heavy metals in water samples. Contaminated water leads to serious health problems and environmental issues. Paper is ideally suited for point-of-care testing, as it is low cost, disposable, and multi-functional. Initial sensor designs were manufactured on paper substrates using combinations of inkjet printing and screen printing technologies using silver and carbon inks. Bismuth onion-like carbon nanoparticle ink was manufactured and used as the active material of the sensor for both commercial and paper-based sensors, which were compared using standard electrochemical analysis techniques. The results highlight the potential of paper-based sensors to be used effectively for rapid water quality monitoring at the point-of-need.

I Situ Surface X-Ray Diffraction Studies of Electrochemically Deposited Monolayers

NASA Astrophysics Data System (ADS)

Yee, Dennis

1995-01-01

In situ x-ray diffraction has been used to determine the detailed atomic structure of electrochemically deposited lead, thallium, and bismuth monolayers on the silver (111) electrode surface. A review of our previously published lead and thallium monolayer results and the first in situ surface x-ray crystallographic study of the bismuth monolayer structure is presented. The crystallographic analysis of the bismuth Bragg rod intensities and the interference between the bismuth Bragg rod and silver crystal truncation rod scattering were used to determine the detailed atomic structure of the bismuth on silver (111) system at the liquid-solid interface. Our previous in situ x-ray diffraction studies showed that the bismuth monolayer lattice is rectangular and uniaxially incommensurate with the underlying hexagonal silver surface. A crystallographic analysis of the measured structure factor magnitudes reveals that the monolayer forms chains of atoms on the silver surface, similar to the bulk Bi(110)_{rh} plane, with a near neighbor distance of 3.12 +/- 0.01 A and a bond angle of 93 +/- 1^circ, consistent with the bulk Bi(110) _{rh} plane values. The crystallographic refinement also shows that the bismuth monolayer atoms are anisotropically disordered with a rms disorder of 0.25 +/- 0.03 A in the incommensurate direction and 0.09 +/- 0.03 A rms in the commnensurate direction. The interference between the Bi(20) Bragg rod and the Ag(10L)_ {h} crystal truncation rod scattering reveals that one set of bismuth atoms is registered near the bridge sites of the silver (111) surface while another set is registered near the 3-fold hollow sites. In addition, the Bi-Ag d-spacing (3.1 +/- 0.1 A) is found to be consistent with the bulk bismuth near neighbor distance. The bismuth z-direction rms disorder (1.01 +/- 0.08 A) is found to be dominated by the roughness of the underlying silver (sigma_{Ag} = 0.9 +/- 0.1 A rms). Using the estimated bismuth-bismuth spring constant of 1.41 +/- 0.07 eV/A^2 from our measured bismuth two-dimensional compressibility, two simple models are used to try and understand the origin of the anisotropic disorder. A simple two-dimensional isotropic thermal fluctuation model shows that thermal fluctuations are not large enough to account for all of the measured excess disorder in the incommensurate direction. A simple one-dimensional Frenkel-Kontorova model shows that the substrate-induced disorder can account for the anisotropic disorder, assuming a substrate sinusoidal potential strength of 0.35 +/- 0.02 eV.

Microwave-induced Bismuth Salts-mediated Synthesis of Molecules of Medicinal Interests.

PubMed

Bandyopadhyay, Debasish; Chavez, Ashlee; Banik, Bimal K

2017-01-01

Bismuth salts-mediated reactions have become a powerful tool for the synthesis of diverse medicinally-significant compounds because of their low-toxicity (non-toxic) and Lewis acidic capacity. In fact, LD50 of bismuth nitrate is lower than table salt. On the other hand, microwave-induced chemical synthesis is considered as a major greener route in modern chemistry. A total of 139 publications (including a few authentic web links) have been reviewed mainly to discuss bismuth salts-induced electrophilic aromatic substitution, protection-deprotection chemistry of carbonyl compounds, enamination, oxidation, carbohydrate chemistry, hydrolysis, addition-elimination route, Paal-Knorr reaction, Clauson-kaas synthesis, Michael addition, aza-Michael addition, Hantzsch reaction, Biginelli reaction, Ferrier rearrangement, Pechmann condensation, Diels-Alder and aza-Diels- Alder reactions, as well as effects of microwave irradiation in a wide range of chemical transformations. Bismuth salts-mediated reactions are developed for the synthesis of diverse organic molecules of medicinal significance. Reactions conducted with bismuth salts are environmentally benign, economical, rapid and high yielding. Microwave irradiation has accelerated these reactions significantly. It is believed that bismuth salts released corresponding acids in the media during the reaction. However, a coordination of bismuth salt to the electronegative atom is also observed in the NMR study. Bismuth has much less control (less attractive forces) over anions (for example, halides, nitrate, sulfate and triflates) compared to alkali metals. Therefore, it forms weak bond with electronegative atoms more readily and facilitates the reactions significantly. Many products obtained via bismuth salts-mediated reactions are medicinally active or intermediate for the synthesis of biologically active molecules including antifungal, anti-parasitic, anticancer and antibacterial agents, as well as agents to prevent Leishmaniosis and Chagas' diseases. Bismuth salts are able to (i) generate mineral acids in the reaction media and (ii) coordinate with electronegative atoms to facilitate the reaction. When the reagents and the catalyst (bismuth salt) are subjected to microwave irradiation, microwave passes through the (glass) walls of the reaction vessel and heat only the reactants avoiding local overheating at the wall of the vessel. Accordingly, the possibility of side reaction and subsequent by-product formation are reduced abruptly which in turn increases the yield of the desired product. The extreme rapidity with excellent yield of the product can be rationalized as a synergistic effect of the bismuth salts and microwave irradiation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Bismuth-induced Raman modes in GaP 1– xBi x

DOE PAGES

Christian, Theresa M.; Fluegel, Brian; Beaton, Daniel A.; ...

2016-09-02

Here, dilute bismide semiconductor alloys are a promising material platform for optoelectronic devices due to drastic impacts of bismuth on the electronic structure of the alloy. At the same time, the details of bismuth incorporation in the lattice are not fully understood. In this work, we conduct Raman scattering spectroscopy on GaP 1- xBi x epilayers grown by molecular beam epitaxy (MBE) and identify several bismuth-related Raman features including gap vibration modes at 296, 303, and 314 cm -1. This study paves the way for more detailed analysis of the local symmetry at bismuth incorporation sites in the dilute bismidemore » alloy regime.« less

Investigation on gas sensing properties of Ag doped BiFeO3

NASA Astrophysics Data System (ADS)

Bagwaiya, Toshi; Khade, Poonam; Reshi, Hilal Ahmad; Bhattacharya, Shovit; Shelke, Vilas; Kaur, Manmeet; Debnath, A. K.; Muthe, K. P.; Gadkari, S. C.

2018-04-01

Bismuth ferrite (BFO) and Ag substituted Bismuth ferrite with perovskite structure have been synthesized using sol-gel method and investigated for their gas sensing properties. Single phase and rhombohedral crystal structure of the samples were confirmed from XRD pattern. Oxidation state of the elements is confirmed using X-Ray Photoelectron Spectroscopy (XPS). Since Ag substituted Bismuth ferrite exhibited pronounced response to H2S gas as compared to other gases, H2S gas sensing properties of Bismuth ferrite (BFO) and Ag substituted Bismuth ferrite were investigated in detail. Bi0.9Ag0.1FeO3 (BAFO) exhibits enhanced sensitivity, quick response and selectivity towards H2S as compared to BFO.

METHOD OF SEPARATING FISSION PRODUCTS FROM FUSED BISMUTH-CONTAINING URANIUM

DOEpatents

Wiswall, R.H.

1958-06-24

A process is described for removing metal selectively from liquid metal compositions. The method effects separation of flssion product metals selectively from dilute solution in fused bismuth, which contains uraniunn in solution without removal of more than 1% of the uranium. The process comprises contacting the fused bismuth with a fused salt composition consisting of sodium, potassium and lithium chlorides, adding to fused bismuth and molten salt a quantity of bismuth chloride which is stoichiometrically required to convert the flssion product metals to be removed to their chlorides which are more stable in the fused salt than in the molten metal and are, therefore, preferentially taken up in the fused salt phase.

Structural Dynamics and Evolution of Bismuth Electrodes during Electrochemical Reduction of CO 2 in Imidazolium-Based Ionic Liquid Solutions

DOE PAGES

Medina-Ramos, Jonnathan; Lee, Sang Soo; Fister, Timothy T.; ...

2017-09-12

Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO 2 into CO were examined via X-ray absorption spectroscopy (including XANES and EXAFS), electrochemical quartz crystal microbalance (EQCM) and in situ X-ray reflectivity (XR). Measurements were performed with bismuth electrodes immersed in acetonitrile (MeCN) solutions containing a 1-butyl-3-methylimidazolium ([BMIM] +) ionic liquid promoter or electrochemically inactive tetrabutylammonium supporting electrolytes (TBAPF 6 or TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi 2O 3) and metallic bismuth (Bi 0), and that the reduction of oxidized bismuth speciesmore » to Bi 0 is fully achieved under potentials at which CO 2 activation takes place. Furthermore, EQCM measurements conducted during cyclic voltammetry revealed that a bismuth-coated quartz crystal exhibits significant shifts in resistance (ΔR) prior to the onset of CO 2 reduction near -1.75 V vs. Ag/AgCl and pronounced hysteresis in frequency (Δf) and ΔR, which suggests significant changes in roughness or viscosity at the Bi/[BMIM] + solution interface. In situ XR performed on rhombohedral Bi (001) oriented films indicates extensive restructuring of the bismuth film cathodes takes place upon polarization to potentials more negative than -1.6 V vs. Ag/AgCl, which is characterized by a decrease of the Bi (001) Bragg peak intensity of ≥50% in [BMIM]OTf solutions in the presence and absence of CO 2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. By contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO 2 reduction. In conclusion, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM] + based electrolytes, including the reduction of bismuth oxide to bismuth metal, changes in roughness and near-surface viscosity.« less

Enhancement of bismuth antibacterial activity with lipophilic thiol chelators.

PubMed Central

Domenico, P; Salo, R J; Novick, S G; Schoch, P E; Van Horn, K; Cunha, B A

1997-01-01

The antibacterial properties of bismuth are greatly enhanced when bismuth is combined with certain lipophilic thiol compounds. Antibacterial activity was enhanced from 25- to 300-fold by the following seven different thiols, in order of decreasing synergy: 1,3-propanedithiol, dimercaprol (BAL), dithiothreitol, 3-mercapto-2-butanol, beta-mercaptoethanol, 1-monothioglycerol, and mercaptoethylamine. The dithiols produced the greatest synergy with bismuth at optimum bismuth-thiol molar ratios of from 3:1 to 1:1. The monothiols were generally not as synergistic and required molar ratios of from 1:1 to 1:4 for optimum antibacterial activity. The most-active mono- or dithiols were also the most soluble in butanol. The intensity of the yellow formed by bismuth-thiol complexes reflected the degree of chelation and correlated with antibacterial potency at high molar ratios. The bismuth-BAL compound (BisBAL) was active against most bacteria, as assessed by broth dilution, agar diffusion, and agar dilution analyses. Staphylococci (MIC, 5 to 7 microM Bi3+) and Helicobacter pylori (MIC, 2.2 microM) were among the most sensitive bacteria. Gram-negative bacteria were sensitive (MIC, < 17 microM). Enterococci were relatively resistant (MIC, 63 microM Bi3+). The MIC range for anaerobes was 15 to 100 microM Bi3+, except for Clostridium difficile (MIC, 7.5 microM). Bactericidal activity averaged 29% above the MIC. Bactericidal activity increased with increasing pH and/or increasing temperature. Bismuth-thiol solubility, stability, and antibacterial activity depended on pH and the bismuth-thiol molar ratio. BisBAL was stable but ineffective against Escherichia coli at pH 4. Activity and instability (reactivity) increased with increasing alkalinity. BisBAL was acid soluble at a molar ratio of greater than 3:2 and alkaline soluble at a molar ratio of less than 2:3. In conclusion, certain lipophilic thiol compounds enhanced bismuth antibacterial activity against a broad spectrum of bacteria. The activity, solubility, and stability of BisBAL were strongly dependent on the pH, temperature, and molar ratio. Chelation of bismuth with certain thiol agents enhanced the solubility and lipophilicity of this cationic heavy metal, thereby significantly enhancing its potency and versatility as an antibacterial agent. PMID:9257744

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2010 CFR

2010-04-01

... amounts consistent with good manufacturing practice. (c) Labeling. The color additive and any mixture... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2162 Bismuth oxychloride. (a) Identity and specifications. (1) The color additive bismuth oxychloride shall conform in identity and specifications to the...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medina-Ramos, Jonnathan; Lee, Sang Soo; Fister, Timothy T.

Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO 2 into CO were examined via X-ray absorption spectroscopy (including XANES and EXAFS), electrochemical quartz crystal microbalance (EQCM) and in situ X-ray reflectivity (XR). Measurements were performed with bismuth electrodes immersed in acetonitrile (MeCN) solutions containing a 1-butyl-3-methylimidazolium ([BMIM] +) ionic liquid promoter or electrochemically inactive tetrabutylammonium supporting electrolytes (TBAPF 6 or TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi 2O 3) and metallic bismuth (Bi 0), and that the reduction of oxidized bismuth speciesmore » to Bi 0 is fully achieved under potentials at which CO 2 activation takes place. Furthermore, EQCM measurements conducted during cyclic voltammetry revealed that a bismuth-coated quartz crystal exhibits significant shifts in resistance (ΔR) prior to the onset of CO 2 reduction near -1.75 V vs. Ag/AgCl and pronounced hysteresis in frequency (Δf) and ΔR, which suggests significant changes in roughness or viscosity at the Bi/[BMIM] + solution interface. In situ XR performed on rhombohedral Bi (001) oriented films indicates extensive restructuring of the bismuth film cathodes takes place upon polarization to potentials more negative than -1.6 V vs. Ag/AgCl, which is characterized by a decrease of the Bi (001) Bragg peak intensity of ≥50% in [BMIM]OTf solutions in the presence and absence of CO 2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. By contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO 2 reduction. In conclusion, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM] + based electrolytes, including the reduction of bismuth oxide to bismuth metal, changes in roughness and near-surface viscosity.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medina-Ramos, Jonnathan; Lee, Sang Soo; Fister, Timothy T.

Real-time changes in the composition and structure of bismuth electrodes used for catalytic conversion of CO2 into CO were examined via X-ray absorption spectroscopy (including XANES and EXAFS), electrochemical quartz crystal microbalance (EQCM), and in situ X-ray reflectivity (XR). Measurements were performed with bismuth electrodes immersed in acetonitrile (MeCN) solutions containing a 1-butyl-3-methylimidazolium ([BMIM]+) ionic liquid promoter or electrochemically inactive tetrabutylammonium supporting electrolytes (TBAPF6 and TBAOTf). Altogether, these measurements show that bismuth electrodes are originally a mixture of bismuth oxides (including Bi2O3) and metallic bismuth (Bi0) and that the reduction of oxidized bismuth species to Bi0 is fully achieved undermore » potentials at which CO2 activation takes place. Furthermore, EQCM measurements conducted during cyclic voltammetry revealed that a bismuth-coated quartz crystal exhibits significant shifts in resistance (ΔR) prior to the onset of CO2 reduction near -1.75 V vs Ag/AgCl and pronounced hysteresis in frequency (Δf) and ΔR, which suggests significant changes in roughness or viscosity at the Bi/[BMIM]+ solution interface. In situ XR performed on rhombohedral Bi (001) oriented films indicates that extensive restructuring of the bismuth film cathodes takes place upon polarization to potentials more negative than -1.6 V vs Ag/AgCl, which is characterized by a decrease of the Bi (001) Bragg peak intensity of ≥50% in [BMIM]OTf solutions in the presence and absence of CO2. Over 90% of the reflectivity is recovered during the anodic half-scan, suggesting that the structural changes are mostly reversible. In contrast, such a phenomenon is not observed for thin Bi (001) oriented films in solutions of tetrabutylammonium salts that do not promote CO2 reduction. Overall, these results highlight that Bi electrodes undergo significant potential-dependent chemical and structural transformations in the presence of [BMIM]+-based electrolytes, including the reduction of bismuth oxide to bismuth metal and changes in roughness and near-surface viscosity.« less

Separation of bismuth from gram amounts of thallium and silver by cation-exchange chromatography in nitric acid.

PubMed

Meintjies, E; Strelow, F W; Victor, A H

1987-04-01

Traces and small amounts of bismuth can be separated from gram amounts of thallium and silver by successively eluting these elements with 0.3M and 0.6M nitric acid from a column containing 13 ml (3 g) of AG50W-X4, a cation-exchanger (100-200 mesh particle size) with low cross-linking. Bismuth is retained and can be eluted with 0.2M hydrobromic acid containing 20% v/v acetone, leaving many other trace elements absorbed. Elution of thallium is quite sharp, but silver shows a small amount of tailing (less than 1 gmg/ml silver in the eluate) when gram amounts are present, between 20 and 80 mug of silver appearing in the bismuth fraction. Relevant elution curves and results for the analysis of synthetic mixtures containing between 50 mug and 10 mg of bismuth and up to more than 1 g of thallium and silver are presented, as well as results for bismuth in a sample of thallium metal and in Merck thallium(I) carbonate. As little as 0.01 ppm of bismuth can be determined when the separation is combined with electrothermal atomic-absorption spectrometry.

Evaluation of the strength and radiopacity of Portland cement with varying additions of bismuth oxide.

PubMed

Saliba, E; Abbassi-Ghadi, S; Vowles, R; Camilleri, J; Hooper, S; Camilleri, J

2009-04-01

To study the effect of addition of various proportions of bismuth oxide on compressive strength and radiopacity of Portland cement. The compressive strength of white Portland cement and cement replaced with 10, 15, 20, 25 and 30% bismuth oxide was evaluated by testing cylinders 6 mm in diameter and 12 mm high. Twelve cylinders were tested for each material under study. The radiopacity of the cements tested was evaluated using an aluminium step-wedge and densitometer. The optical density was compared with the relevant thickness of aluminium (Al). Statistical analysis was performed using Analysis of Variance (ANOVA) with P = 0.05 and Tukey test to perform multiple comparison tests. Various additions of bismuth oxide had no significant effect on the strength of the material when compared with the unmodified Portland cement (P > 0.05). The radiopacity of the cements tested ranged from 2.02 mm Al for Portland cement to 9.79 mm Al for the highest bismuth replacement. Addition of bismuth oxide did not affect the compressive strength of Portland cement. All the bismuth oxide cement mixtures had radio-opacities higher than 3 mm thickness of aluminium.

Study of the structure, dielectric and ferroelectric behavior of BaBi4+δTi4O15 ceramics

NASA Astrophysics Data System (ADS)

Khokhar, Anita; Goyal, Parveen K.; Thakur, O. P.; Sreenivas, K.

2016-05-01

The structure and ferroelectric properties of excess bismuth doped barium bismuth titanate BaBi4+δTi4O15 (δ = 2 - 10 wt.%)) ceramics prepared by solid-state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of a single phase material with a change in the orthorhombic distortion with varying excess of bismuth content. There is no change in the phase transition temperature (Tm) while the relaxor behaviour has been modified significantly with excess of bismuth doping. Saturated hysteresis loops with high remnant polarization (Pr ~ 12.5 µC/cm2), low coercive fields (Ec ~ 26 kV/cm) are measured and a high piezoelectric coefficient (d33 ~ 29 pC/N) is achieved in poled BaBi4Ti4O15 ceramics prepared with up to 8 wt.% of excess bismuth oxide. The improvement in the ferroelectric properties with increase in the excess bismuth content in BaBi4Ti4O15 ceramics has been explained in terms of changing oxygen vacancy concentration and structural relaxation. Tunable ferroelectric materials can be obtained by manipulating the doping amount of excess bismuth.

Adverse events with bismuth salts for Helicobacter pylori eradication: Systematic review and meta-analysis

PubMed Central

Ford, Alexander C; Malfertheiner, Peter; Giguère, Monique; Santana, José; Khan, Mostafizur; Moayyedi, Paul

2008-01-01

AIM: To assess the safety of bismuth used in Helicobacter pylori (H pylori) eradication therapy regimens. METHODS: We conducted a systematic review and meta-analysis. MEDLINE and EMBASE were searched (up to October 2007) to identify randomised controlled trials comparing bismuth with placebo or no treatment, or bismuth salts in combination with antibiotics as part of eradication therapy with the same dose and duration of antibiotics alone or, in combination, with acid suppression. Total numbers of adverse events were recorded. Data were pooled and expressed as relative risks with 95% confidence intervals (CI). RESULTS: We identified 35 randomised controlled trials containing 4763 patients. There were no serious adverse events occurring with bismuth therapy. There was no statistically significant difference detected in total adverse events with bismuth [relative risk (RR) = 1.01; 95% CI: 0.87-1.16], specific individual adverse events, with the exception of dark stools (RR = 5.06; 95% CI: 1.59-16.12), or adverse events leading to withdrawal of therapy (RR = 0.86; 95% CI: 0.54-1.37). CONCLUSION: Bismuth for the treatment of H pylori is safe and well-tolerated. The only adverse event occurring significantly more commonly was dark stools. PMID:19109870

A novel structure photonic crystal fiber based on bismuth-oxide for optical parametric amplification

NASA Astrophysics Data System (ADS)

Jin, Cang; Yuan, Jinhui; Yu, Chongxiu

2010-11-01

The heavy metal oxide glasses containing bismuth such as bismuth sesquioxide show unique high refractive index. In addition, the bismuth-oxide based glass does not include toxic elements such as Pb, As, Se, Te, and exhibits well chemical, mechanical and thermal stability. Hence, it is used to fabricate high nonlinear fiber for nonlinear optical application. Although the bismuth-oxide based high nonlinear fiber can be fusion-spliced to conventional silica fibers and have above advantages, yet it suffers from large group velocity dispersion because of material chromatic dispersion which restricts its utility. In regard to this, the micro-structure was introduced to adjust the dispersion of bismuth-oxide high nonlinear fiber in the 1550nm wave-band. In this paper, a hexagonal solid-core micro-structure is developed to balance its dispersion and nonlinearity. Our simulation and calculation results show that the bismuth-oxide based photonic crystal fiber has near zero dispersion around 1550nm where the optical parametric amplification suitable wavelength is. Its dispersion slop in the communication wavelength range is also relatively flat. Moreover, both nonlinear coefficient and model filed distribution were simulated, respectively.

[Molecular remission induced by gemtuzumab ozogamicin in an elderly patient with relapsed acute promyelocytic leukemia].

PubMed

Yago, Kazuhiro; Aono, Maki; Shimada, Hideto

2010-04-01

A 79-year-old female with acute promyelocytic leukemia (APL) presented with second hematological relapse. She had been treated previously with modified AIDA protocol as the front-line therapy and had achieved complete remission. During ATRA maintenance therapy, the first hematological relapse occurred and she was treated with arsenic trioxide (ATO), achieving the second complete remission. After four courses of consolidation therapy of ATO, the second hematological relapse occurred. At this time, except for a transient effect of tamibarotene, neither arsenic trioxide nor combination chemotherapy was effective. The patient was then treated with two courses of gemtuzumab ozogamicin (GO) and achieved the third complete remission. At present, she is maintaining molecular remission more than one year after GO treatment. GO is considered to be a promising agent for elderly patients with relapsed acute promyelocytic leukemia resistant to arsenic trioxide.

Thermodynamic and kinetic studies of As2O3 toxicological effects on human insulin in generation diabetes mellitus

NASA Astrophysics Data System (ADS)

Mohsennia, Mohsen; Motaharinejad, Atieh; Rafiee-Pour, Hossain-Ali; Torabbeigi, Marzieh

2017-12-01

The interaction of arsenic trioxide with human insulin was investigated by circular dichroism (CD), cyclic voltammetry and electrophoresis techniques. The interfacial behavior of insulin in presence of As2O3 onto the Ag electrode surface was studied at 310 K in phosphate buffer solution (PBS). According to Far-UV CD spectroscopy results, As2O3 caused to decrease in structural compactness and variety of alpha helix into beta structures. Near-UV CD indicated that As2O3 dissociates disulfide linkage in insulin structure. The kinetic parameters, including charge-transfer coefficient and apparent heterogeneous electron transfer rate constant were also determined. The thermodynamic parameters of insulin denaturation in presence of arsenic trioxide were calculated and reported. The obtained results indicated strong adsorption of insulin in presence of arsenic trioxide onto the Ag surface via chemisorptions.

Arsenic trioxide and all-trans retinoic acid treatment for acute promyelocytic leukaemia in all risk groups (AML17): results of a randomised, controlled, phase 3 trial.

PubMed

Burnett, Alan K; Russell, Nigel H; Hills, Robert K; Bowen, David; Kell, Jonathan; Knapper, Steve; Morgan, Yvonne G; Lok, Jennie; Grech, Angela; Jones, Gail; Khwaja, Asim; Friis, Lone; McMullin, Mary Frances; Hunter, Ann; Clark, Richard E; Grimwade, David

2015-10-01

Acute promyelocytic leukaemia is a chemotherapy-sensitive subgroup of acute myeloid leukaemia characterised by the presence of the PML-RARA fusion transcript. The present standard of care, chemotherapy and all-trans retinoic acid (ATRA), results in a high proportion of patients being cured. In this study, we compare a chemotherapy-free ATRA and arsenic trioxide treatment regimen with the standard chemotherapy-based regimen (ATRA and idarubicin) in both high-risk and low-risk patients with acute promyelocytic leukaemia. In the randomised, controlled, multicentre, AML17 trial, eligible patients (aged ≥16 years) with acute promyelocytic leukaemia, confirmed by the presence of the PML-RARA transcript and without significant cardiac or pulmonary comorbidities or active malignancy, and who were not pregnant or breastfeeding, were enrolled from 81 UK hospitals and randomised 1:1 to receive treatment with ATRA and arsenic trioxide or ATRA and idarubicin. ATRA was given to participants in both groups in a daily divided oral dose of 45 mg/m(2) until remission, or until day 60, and then in a 2 weeks on-2 weeks off schedule. In the ATRA and idarubicin group, idarubicin was given intravenously at 12 mg/m(2) on days 2, 4, 6, and 8 of course 1, and then at 5 mg/m(2) on days 1-4 of course 2; mitoxantrone at 10 mg/m(2) on days 1-4 of course 3, and idarubicin at 12 mg/m(2) on day 1 of the final (fourth) course. In the ATRA and arsenic trioxide group, arsenic trioxide was given intravenously at 0·3 mg/kg on days 1-5 of each course, and at 0·25 mg/kg twice weekly in weeks 2-8 of course 1 and weeks 2-4 of courses 2-5. High-risk patients (those presenting with a white blood cell count >10 × 10(9) cells per L) could receive an initial dose of the immunoconjugate gemtuzumab ozogamicin (6 mg/m(2) intravenously). Neither maintenance treatment nor CNS prophylaxis was given to patients in either group. All patients were monitored by real-time quantitative PCR. Allocation was by central computer minimisation, stratified by age, performance status, and de-novo versus secondary disease. The primary endpoint was quality of life on the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 global health status. All analyses are by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN55675535. Between May 8, 2009, and Oct 3, 2013, 235 patients were enrolled and randomly assigned to ATRA and idarubicin (n=119) or ATRA and arsenic trioxide (n=116). Participants had a median age of 47 years (range 16-77; IQR 33-58) and included 57 high-risk patients. Quality of life did not differ significantly between the treatment groups (EORTC QLQ-C30 global functioning effect size 2·17 [95% CI -2·79 to 7·12; p=0·39]). Overall, 57 patients in the ATRA and idarubicin group and 40 patients in the ATRA and arsenic trioxide group reported grade 3-4 toxicities. After course 1 of treatment, grade 3-4 alopecia was reported in 23 (23%) of 98 patients in the ATRA and idarubicin group versus 5 (5%) of 95 in the ATRA and arsenic trioxide group, raised liver alanine transaminase in 11 (10%) of 108 versus 27 (25%) of 109, oral toxicity in 22 (19%) of 115 versus one (1%) of 109. After course 2 of treatment, grade 3-4 alopecia was reported in 25 (28%) of 89 patients in the ATRA and idarubicin group versus 2 (3%) of 77 in the ATRA and arsenic trioxide group; no other toxicities reached the 10% level. Patients in the ATRA and arsenic trioxide group had significantly less requirement for most aspects of supportive care than did those in the ATRA and idarubicin group. ATRA and arsenic trioxide is a feasible treatment in low-risk and high-risk patients with acute promyelocytic leukaemia, with a high cure rate and less relapse than, and survival not different to, ATRA and idarubicin, with a low incidence of liver toxicity. However, no improvement in quality of life was seen. Copyright © 2015 Elsevier Ltd. All rights reserved.

Oral arsenic plus retinoic acid versus intravenous arsenic plus retinoic acid for non-high-risk acute promyelocytic leukaemia: a non-inferiority, randomised phase 3 trial.

PubMed

Zhu, Hong-Hu; Wu, De-Pei; Du, Xin; Zhang, Xi; Liu, Lin; Ma, Jun; Shao, Zong-Hong; Ren, Han-Yun; Hu, Jian-Da; Xu, Kai-Lin; Wang, Jing-Wen; Song, Yong-Ping; Fang, Mei-Yun; Li, Juan; Yan, Xiao-Yan; Huang, Xiao-Jun

2018-06-05

Intravenous arsenic trioxide plus all-trans retinoic acid (ATRA) without chemotherapy is the standard of care for non-high-risk acute promyelocytic leukaemia (white blood cell count ≤10 × 10 9 per L), resulting in cure in more than 95% of cases. However, a pilot study of treatment with oral arsenic realgar-Indigo naturalis formula (RIF) plus ATRA without chemotherapy, which has a more convenient route of administration than the standard intravenous regimen, showed high efficacy. In this study, we compare an oral RIF plus ATRA treatment regimen with the standard intravenous arsenic trioxide plus ATRA treatment regimen in patients with non-high-risk acute promyelocytic leukaemia. We did a multicentre, non-inferiority, open-label, randomised, controlled phase 3 trial at 14 centres in China. Patients aged 18-70 years with newly diagnosed (within 7 days) non-high-risk acute promyelocytic leukaemia, and a WHO performance status of 2 or less were eligible. Patients were randomly assigned (2:1) to receive treatment with RIF-ATRA or arsenic trioxide-ATRA as the induction and consolidation therapy. Randomisation was done centrally with permuted blocks and stratification according to trial centre and was implemented through an interactive web response system. RIF (60 mg/kg bodyweight daily in an oral divided dose) or arsenic trioxide (0·15 mg/kg daily in an intravenous dose) and ATRA (25 mg/m 2 daily in an oral divided dose) were used until complete remission was achieved. The home-based consolidation therapy was RIF (60 mg/kg daily in an oral divided dose) or intravenous arsenic trioxide (0·15 mg/kg daily in an intravenous dose) in a 4-week on 4-week off regimen for four cycles and ATRA (25 mg/m 2 daily in an oral divided dose) in a 2-week on 2-week off regimen for seven cycles. Patients and treating physicians were not masked to treatment allocation. The primary outcome was event-free survival at 2 years. A non-inferiority margin of -10% was used to assess non-inferiority. Primary analyses were done in a modified intention-to-treat population of all patients who received at least one dose of their assigned treatment and the per-protocol population. This study was registered with the Chinese Clinical Trial Registry (ChiCTR-TRC-13004054), and the trial is complete. Between Feb 13, 2014, and Aug 31, 2015, 109 patients were enrolled and assigned to RIF-ATRA (n=72) or arsenic trioxide-ATRA (n=37). Three patients in the RIF-ATRA and one in the arsenic trioxide-ATRA did not receive their assigned treatment. After a median follow-up of 32 months (IQR 27-36), 67 (97%) of 69 patients in the RIF-ATRA group and 34 (94%) of 36 in the arsenic trioxide-ATRA group had achieved 2-year event-free survival in the modified intention-to-treat population. The percentage difference in event-free survival was 2·7% (95% CI, -5·8 to 11·1). The lower limit of the 95% CI for the difference in event-free survival was greater than the -10% non-inferiority margin, confirming non-inferiority (p=0·0017). Non-inferiority was also confirmed in the per-protocol population. During induction therapy, grade 3-4 hepatic toxic effects (ie, increased liver aspartate aminotransferase or alanine transaminase concentrations) were reported in six (9%) of 69 patients in the RIF-ATRA group versus five (14%) of 36 patients in the arsenic trioxide-ATRA group; grade 3-4 infection was reported in 15 (23%) of 64 versus 15 (42%) of 36 patients. Two patients in the arsenic trioxide-ATRA group died during induction therapy (one from haemorrhage and one from thrombocytopenia). Oral RIF plus ATRA is not inferior to intravenous arsenic trioxide plus ATRA for the treatment of patients with non-high-risk acute promyelocytic leukaemia. This study suggests that a completely oral, chemotherapy-free model might be an alternative to the standard intravenous treatment for patients with non-high-risk acute promyelocytic leukaemia. Foundation for innovative research group of the National Natural Science Foundation of China, the Beijing Municipal Science and Technology Commission, the National Key R&D Program of China, and the National Natural Science Foundation of China. Copyright © 2018 Elsevier Ltd. All rights reserved.

METHOD OF PREPARING URANIUM, THORIUM, OR PLUTONIUM OXIDES IN LIQUID BISMUTH

DOEpatents

Davidson, J.K.; Robb, W.L.; Salmon, O.N.

1960-11-22

A method is given for forming compositions, as well as the compositions themselves, employing uranium hydride in a liquid bismuth composition to increase the solubility of uranium, plutonium and thorium oxides in the liquid bismuth. The finely divided oxide of uranium, plutonium. or thorium is mixed with the liquid bismuth and uranium hydride, the hydride being present in an amount equal to about 3 at. %, heated to about 5OO deg C, agitated and thereafter cooled and excess resultant hydrogen removed therefrom.

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2010 CFR

2010-04-01

... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1162 Bismuth oxychloride. (a) Identity. (1) The color additive bismuth oxychloride is a synthetically prepared white or nearly white amorphous or finely crystalline, odorless powder consisting principally of BiOCl. (2) Color additive mixtures for drug use made...

Ultrasonication of Bismuth Telluride Nanocrystals Fabricated by Solvothermal Method

NASA Technical Reports Server (NTRS)

Chu, Sang-Hyon; Choi, Sang H.; Kim, Jae-Woo; King, Glen C.; Elliott, James R.

2006-01-01

The objective of this study is to evaluate the effect of ultrasonication on bismuth telluride nanocrystals prepared by solvothermal method. In this study, a low dimensional nanocrystal of bismuth telluride (Bi2Te3) was synthesized by a solvothermal process in an autoclave at 180 C and 200 psi. During the solvothermal reaction, organic surfactants effectively prevented unwanted aggregation of nanocrystals in a selected solvent while controlling the shape of the nanocrystal. The atomic ratio of bismuth and tellurium was determined by energy dispersive spectroscopy (EDS). The cavitational energy created by the ultrasonic probe was varied by the ultrasonication process time, while power amplitude remained constant. The nanocrystal size and its size distribution were measured by field emission scanning electron microscopy (FESEM) and a dynamic light scattering system. When the ultrasonication time increased, the average size of bismuth telluride nanocrystal gradually increased due to the direct collision of nanocrystals. The polydispersity of the nanocrystals showed a minimum when the ultrasonication was applied for 5 min. Keywords: bismuth telluride, nanocrystal, low-dimensional, ultrasonication, solvothermal

Adaptive statistical iterative reconstruction and bismuth shielding for evaluation of dose reduction to the eye and image quality during head CT

NASA Astrophysics Data System (ADS)

Kim, Myeong Seong; Choi, Jiwon; Kim, Sun Young; Kweon, Dae Cheol

2014-03-01

There is a concern regarding the adverse effects of increasing radiation doses due to repeated computed tomography (CT) scans, especially in radiosensitive organs and portions thereof, such as the lenses of the eyes. Bismuth shielding with an adaptive statistical iterative reconstruction (ASIR) algorithm was recently introduced in our clinic as a method to reduce the absorbed radiation dose. This technique was applied to the lens of the eye during CT scans. The purpose of this study was to evaluate the reduction in the absorbed radiation dose and to determine the noise level when using bismuth shielding and the ASIR algorithm with the GE DC 750 HD 64-channel CT scanner for CT of the head of a humanoid phantom. With the use of bismuth shielding, the noise level was higher in the beam-hardening artifact areas than in the revealed artifact areas. However, with the use of ASIR, the noise level was lower than that with the use of bismuth alone; it was also lower in the artifact areas. The reduction in the radiation dose with the use of bismuth was greatest at the surface of the phantom to a limited depth. In conclusion, it is possible to reduce the radiation level and slightly decrease the bismuth-induced noise level by using a combination of ASIR as an algorithm process and bismuth as an in-plane hardware-type shielding method.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Righettoni, Marco; Pratsinis, Sotiris E., E-mail: sotiris.pratsinis@ptl.mavt.ethz.ch

Highlights: • Flame-made WO{sub 3} nanoparticles with closely controlled crystal and grain size. • Dynamic phase transition of annealing of pure and Si-doped WO{sub 3} by in situ XRD. • Irreversible evolution of WO{sub 3} crystallinity by heating/cooling during its annealing. • Si-doping alters the WO{sub 3} crystallinity dynamics and stabilizes nanosized WO{sub 3}. • Flame-made nano-WO{sub 3} can sense NO at the ppb level. - Abstract: Tungsten trioxide is a semiconductor with distinct applications in gas sensors, catalysis, batteries and pigments. As such the transition between its different crystal structures during its annealing are of interest, especially for sensormore » applications. Here, WO{sub 3} nanoparticles with closely controlled crystal and grain size (9–15 nm) and phase composition are made by flame spray pyrolysis and the formation of different WO{sub 3} phases during annealing is investigated. Most notably, the dynamic phase transition and crystal size evolution of WO{sub 3} during heating and cooling is monitored by in situ X-ray diffraction revealing how metastable WO{sub 3} phases can be captured stably. The effect of Si-doping is studied since it is used in practise to control crystal growth and phase transition during metal oxide synthesis and processing. Finally the influence of annealing on the WO{sub 3} sensing performance of NO, a lung inflammation tracer in the human breath, is explored at the ppb-level.« less

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

... GUIDELINES AND STANDARDS NONFERROUS METALS FORMING AND METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth...-tin-bismuth forming operations' process wastewater shall not exceed the following values: (a) Rolling... monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS NONFERROUS METALS FORMING AND METAL POWDERS POINT SOURCE CATEGORY Lead-Tin-Bismuth...-tin-bismuth forming operations' process wastewater shall not exceed the following values: (a) Rolling... monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions...

Online High Temporal Resolution Measurement of Atmospheric Sulfate and Sulfur Trioxide with a Light Emitting Diode and Liquid Core Waveguide-Based Sensor.

PubMed

Tian, Yong; Shen, Huiyan; Wang, Qiang; Liu, Aifeng; Gao, Wei; Chen, Xu-Wei; Chen, Ming-Li; Zhao, Zongshan

2018-06-13

High temporal resolution components analysis is still a great challenge for the frontier of atmospheric aerosol research. Here, an online high time resolution method for monitoring soluble sulfate and sulfur trioxide in atmospheric aerosols was developed by integrating a membrane-based parallel plate denuder, a particle collector, and a liquid waveguide capillary cell into a flow injection analysis system. The BaCl 2 solution (containing HCl, glycerin, and ethanol) was enabled to quantitatively transform sulfate into a well-distributed BaSO 4 solution for turbidimetric detection. The time resolution for monitoring the soluble sulfate and sulfur trioxide was 15 h -1 . The limits of detection were 86 and 7.3 μg L -1 ( S/ N = 3) with a 20 and 200 μL SO 4 2- solution injection, respectively. Both the interday and intraday precision values (relative standard deviation) were less than 6.0%. The analytical results of the certificated reference materials (GBW(E)08026 and GNM-M07117-2013) were identical to the certified values (no significant difference at a 95% confidence level). The validity and practicability of the developed device were also evaluated during a firecracker day and a routine day, obviously revealing the continuous variance in atmospheric sulfate and sulfur trioxide in both interday and intraday studies.

Structural, morphological, gas sensing and photocatalytic characterization of MoO3 and WO3 thin films prepared by the thermal vacuum evaporation technique

NASA Astrophysics Data System (ADS)

Arfaoui, A.; Touihri, S.; Mhamdi, A.; Labidi, A.; Manoubi, T.

2015-12-01

Thin films of molybdenum trioxide and tungsten trioxide were deposited on glass substrates using a simplified thermal evaporation under vacuum method monitored by heat treatment in flowing oxygen at 500 °C for 1 h. The structural and morphological properties of the films were investigated using X-ray diffraction, Raman spectroscopy, atomic force microscopy and scanning electron microscopy. The X-ray diffraction analysis shows that the films of MoO3 and WO3 were well crystallized in orthorhombic and monoclinic phase respectively with the crystallites preferentially oriented toward (2 0 0) direction parallel a-axis for both samples. In literature, we have shown in previous papers that structural and surface morphology of metal thin films play an important role in the gas detection mechanism. In this article, we have studied the response evolution of MoO3 and WO3 thin films sensors ethanol versus time, working temperature and the concentration of the ethanol. It was found that these films had high sensitivity to ethanol, which made them as a good candidate for the ethanol sensor. Finally, the photocatalytic activity of the samples was evaluated with respect to the degradation reaction of a wastewater containing methylene blue (MB) under UV-visible light irradiation. The molybdenum trioxide exhibits a higher degradation rate than the tungsten trioxide thin films under similar experimental conditions.

Anti-corrosion mechanism of epoxy-resin and different content Fe2O3 coatings on magnesium alloy

NASA Astrophysics Data System (ADS)

Jin, Tao; Kong, Fan-mei; Bai, Rui-qin; Zhang, Ru-liang

2016-12-01

In this study, anti-corrosion coatings were prepared and coated successfully on magnesium alloy substrates by mixing nanopowders, solvent, curing agent with epoxy resin. The effect of the amount of iron trioxide (Fe2O3) on the adhesion strength and corrosion resistance on magnesium alloy was investigated with standard protocols, and electrochemical measurements were also made in 3.5 wt.% NaCl solutions. The surface morphology and corrosion mechanism after corrosion tests was characterized using FESEM analysis. Nanoparticles in matrix acted as filler, and interstitial cross-linked spaces and other coating artifacts regions (micro cracks and voids) would all affect the anti-corrosion properties of coating. The results showed the proper powder content not only provided adhesion strength to these coatings but also improved obviously their anticorrosion. Hydrogen bound to the amine nitrogen (1N) could take part in the curing process rather than hydrogen of the amide site due to the smaller Δ G and the more stable configuration.

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Bismuth oxychloride. 73.1162 Section 73.1162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1162 Bismuth oxychloride. (a) Identity. (1) The...

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Bismuth oxychloride. 73.1162 Section 73.1162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1162 Bismuth oxychloride. (a) Identity. (1) The...

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Bismuth oxychloride. 73.1162 Section 73.1162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1162 Bismuth oxychloride. (a) Identity. (1) The...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES... in lead-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES). Except as...-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following values... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2013 CFR

2013-07-01

...-Tin-Bismuth Forming Subcategory § 471.13 New source performance standards (NSPS). Any new source... pollutants in the lead-tin-bismuth forming operations' process wastewater shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES... in lead-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2014 CFR

2014-07-01

...-Tin-Bismuth Forming Subcategory § 471.13 New source performance standards (NSPS). Any new source... pollutants in the lead-tin-bismuth forming operations' process wastewater shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.13 - New source performance standards (NSPS).

Code of Federal Regulations, 2012 CFR

2012-07-01

...-Tin-Bismuth Forming Subcategory § 471.13 New source performance standards (NSPS). Any new source... pollutants in the lead-tin-bismuth forming operations' process wastewater shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES). Except as...-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following values... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

40 CFR 471.14 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.14 Pretreatment standards for existing sources (PSES... in lead-tin-bismuth forming process wastewater introduced into a POTW shall not exceed the following... Maximum for monthly average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with...

Myoclonic encephalopathy due to bismuth salts: treatment with dimercaprol and analysis of CSF transmitters.

PubMed

Molina, J A; Calandre, L; Bermejo, F

1989-03-01

Two cases of myoclonic encephalopathy due to bismuth salts intoxication are reported. In both, treatment with dimercaprol led to clinical recovery. This therapy was shown to enhance bismuth clearance. We also present data on the CSF metabolites dopamine, norepinephrine and serotonin of one patient.

PRODUCTION OF PLUTONIUM FLUORIDE FROM BISMUTH PHOSPHATE PRECIPITATE CONTAINING PLUTONIUM VALUES

DOEpatents

Brown, H.S.; Bohlmann, E.G.

1961-05-01

A process is given for separating plutonium from fission products present on a bismuth phosphate carrier. The dried carrier is first treated with hydrogen fluoride at between 500 and 600 deg C whereby some fission product fluorides volatilize away from plutonium tetrafluoride, and nonvolatile fission product fluorides are formed then with anhydrous fluorine at between 400 and 500 deg C. Bismuth and plutonium distill in the form of volatile fluorides away from the nonvolatile fission product fluorides. The bismuth and plutonium fluorides are condensed at below 290 deg C.

Multi-elemental bio-imaging of rat tissue from a study investigating the bioavailability of bismuth from shotgun pellets.

PubMed

Urgast, Dagmar S; Ellingsen, Dag G; Berlinger, Balázs; Eilertsen, Einar; Friisk, Grete; Skaug, Vidar; Thomassen, Yngvar; Beattie, John H; Kwun, In-Sook; Feldmann, Jörg

2012-07-01

In recent years, bismuth has been promoted as a "green element" and is used as a substitute for the toxic lead in ammunition and other applications. However, the bioavailability and toxicity of bismuth is still not very well described. Following a hunting accident with bismuth-containing shots, a bioavailability study of bismuth from metal pellets inoculated into rat limb muscles was carried out. Bismuth could be found in urine and blood of the animals. Bio-imaging using laser ablation ICP-MS of thin sections of the tissue around the metal implant was carried out to find out more about the distribution of the metal diffusing into the tissue. Two laser ablation systems with different ablation cell designs were compared regarding their analytical performance. Low concentrations of bismuth showing a non-symmetrical pattern were detected in the tissue surrounding the metal implant. This was partly an artefact from cutting the thin sections but also bio-mobilisation of the metals of the implant could be seen. An accumulation of zinc around the implant was interpreted as a marker of inflammation. Challenges regarding sample preparation for laser ablation and bio-imaging of samples of diverse composition became apparent during the analysis.

Enhanced detection of quantum dots labeled protein by simultaneous bismuth electrodeposition into microfluidic channel.

PubMed

Medina-Sánchez, Mariana; Miserere, Sandrine; Cadevall, Miquell; Merkoçi, Arben

2016-02-01

In this study, we propose an electrochemical immunoassay into a disposable microfluidic platform, using quantum dots (QDs) as labels and their enhanced detection using bismuth as an alternative to mercury electrodes. CdSe@ZnS QDs were used to tag human IgG as a model protein and detected through highly sensitive stripping voltammetry of the dissolved metallic component (cadmium in our case). The modification of the screen printed carbon electrodes (SPCEs) was done by a simple electrodeposition of bismuth that was previously mixed with the sample containing QDs. A magneto-immunosandwich assay was performed using a micromixer. A magnet placed at its outlet in order to capture the magnetic beads used as solid support for the immunoassay. SPCEs were integrated at the end of the channel as detector. Different parameters such as bismuth concentration, flow rate, and incubation times, were optimized. The LOD for HIgG in presence of bismuth was 3.5 ng/mL with a RSD of 13.2%. This LOD was about 3.3-fold lower than the one obtained without bismuth. Furthermore, the sensitivity of the system was increased 100-fold respect to experiments carried out with classical screen-printed electrodes, both in presence of bismuth. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Viability of Bismuth as a Green Substitute for Lead in Jacketed .357 Magnum Revolver Bullets

NASA Astrophysics Data System (ADS)

Jenkins, Joel

In seeking to develop environmentally friendly lead-free non-toxic bullets, the research ballistically evaluated the performance of copper-jacketed handgun bullets containing a pure bismuth core. The lead was first removed from 140 grain Hornady(TM) XTPRTM bullets of 38 caliber (.357 diameter) by melting. The empty jackets were then refilled with pure bismuth, including the forming of a correctly sized hollow-point cavity. Due to the lower density of bismuth as compared to lead, the bismuth-cored bullets consistently weighed 125 gains. Conveniently this allowed direct comparison to commercially available 125 grain Hornady(TM) XTPRTM lead-cored bullets of 38 caliber. Both bismuth-cored and lead-cored versions of the 125 grain bullets had identical nose dimensions and jacket material, the only dimensional difference being the bullet length below the cannelure. Shooting took place at an outdoor range using a 357 Magnum Ruger(TM) SP101RTM revolver with 3" barrel as the test weapon. FBI protocols were followed when firing through clothing, wallboard, plywood, steel plates and laminated glass. Wound paths and bullets were captured in ballistic gelatin, with data collected for velocity, penetration, expansion, and weight retention. Bismuth compared favorably with lead in all but the laminated glass test, where it under penetrated due to jacket separation.

Synthesis of WO 3 nanoparticles for superthermites by the template method from silica spheres

NASA Astrophysics Data System (ADS)

Gibot, Pierre; Comet, Marc; Vidal, Loic; Moitrier, Florence; Lacroix, Fabrice; Suma, Yves; Schnell, Fabien; Spitzer, Denis

2011-05-01

Nanosized WO 3 tungsten trioxide was prepared by calcination of H 3P 4W 12O 40· xH 2O phosphotungstic acid, previously dissolved in a silica colloidal solution. The influence of the silica spheres/tungsten precursor weight ratio ( x) was investigated. The pristine oxide powders were characterized by XRD, nitrogen adsorption, SEM and TEM techniques. A specific surface area and a pore volume of 64.2 m 2 g -1 and 0.33 cm 3 g -1, respectively, were obtained for the well-crystallized WO 3 powder prepared with x = 2/3 and after the removal of the silica template. The WO 3 particles exhibit a sphere-shaped morphology with a particle size of 13 and 320 nm as function of the x ratio. The performance and the sensitivity levels of the thermites prepared from aluminium nanoparticles mixed with (i) the smallest tungsten (VI) oxide material and (ii) the microscale WO 3 were compared. The combustion of these energetic composites was investigated by time resolved cinematography (TRC). This unconventional experimental technique consists to ignite the dried compressed composites by using a CO 2 laser beam, in order to determine their ignition delay time (IDT) and their combustion rate. The downsizing WO 3 particles improves, without ambiguity, the energetic performances of the WO 3/Al thermite. For instance, the ignition delay time was greatly shortened from 54 ± 10 ms to 5.7 ± 0.2 ms and the combustion velocity was increased by a factor 50 to reach a value of 4.1 ± 0.3 m/s. In addition, the use of WO 3 nanoparticles sensitizes the mixture to mechanical stimuli but decreases the sensitivity to electrostatic discharge.

Use of arsenic trioxide in remission induction and consolidation therapy for acute promyelocytic leukaemia in the Australasian Leukaemia and Lymphoma Group (ALLG) APML4 study: a non-randomised phase 2 trial.

PubMed

Iland, Harry J; Collins, Marnie; Bradstock, Ken; Supple, Shane G; Catalano, Alberto; Hertzberg, Mark; Browett, Peter; Grigg, Andrew; Firkin, Frank; Campbell, Lynda J; Hugman, Amanda; Reynolds, John; Di Iulio, Juliana; Tiley, Campbell; Taylor, Kerry; Filshie, Robin; Seldon, Michael; Taper, John; Szer, Jeff; Moore, John; Bashford, John; Seymour, John F

2015-09-01

Initial treatment of acute promyelocytic leukaemia traditionally involves tretinoin (all-trans retinoic acid) combined with anthracycline-based risk-adapted chemotherapy, with arsenic trioxide being the treatment of choice at relapse. To try to reduce the relapse rate, we combined arsenic trioxide with tretinoin and idarubicin in induction therapy, and used arsenic trioxide with tretinoin as consolidation therapy. Patients with previously untreated genetically confirmed acute promyelocytic leukaemia were eligible for this study. Eligibilty also required Eastern Cooperative Oncology Group performance status 0-3, age older than 1 year, normal left ventricular ejection fraction, Q-Tc interval less than 500 ms, absence of serious comorbidity, and written informed consent. Patients with genetic variants of acute promyelocytic leukaemia (fusion of genes other than PML with RARA) were ineligible. Induction comprised 45 mg/m(2) oral tretinoin in four divided doses daily on days 1-36, 6-12 mg/m(2) intravenous idarubicin on days 2, 4, 6, and 8, adjusted for age, and 0·15 mg/kg intravenous arsenic trioxide once daily on days 9-36. Supportive therapy included blood products for protocol-specified haemostatic targets, and 1 mg/kg prednisone daily as prophylaxis against differentiation syndrome. Two consolidation cycles with tretinoin and arsenic trioxide were followed by maintenance therapy with oral tretinoin, 6-mercaptopurine, and methotrexate for 2 years. The primary endpoints of the study were freedom from relapse and early death (within 36 days of treatment start) and we assessed improvement compared with the 2 year interim results. To assess durability of remission we compared the primary endpoints and disease-free and overall survival at 5 years in APML4 with the 2 year interim APML4 data and the APML3 treatment protocol that excluded arsenic trioxide. This study is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12605000070639. 124 patients were enrolled between Nov 10, 2004, and Sept 23, 2009, with data cutoff of March 15, 2012. Four (3%) patients died early. After a median follow-up of 4·2 years (IQR, 3·2-5·2), the 5 year freedom from relapse was 95% (95% CI 89-98), disease-free survival was 95% (89-98), event-free survival was 90% (83-94), and overall survival was 94% (89-97). The comparison with APML3 data showed that hazard ratios were 0·23 (95% CI 0·08-0·64, p=0·002) for freedom from relapse, 0·21 (0·07-0·59, p=0·001) for disease-free survival, 0·34 (0·16-0·69, p=0·002) for event-free survival, and 0·35 (0·14-0·91, p=0·02) for overall survival. Incorporation of arsenic trioxide in initial therapy induction and consolidation for acute promyelocytic leukaemia reduced the risk of relapse when compared with historical controls. This improvement, together with a non-significant reduction in early deaths and absence of deaths in remission, translated into better event-free and overall survival. Phebra. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative investigations of sodium arsenite, arsenic trioxide and cadmium sulphate in combination with gamma-radiation on apoptosis, micronuclei induction and DNA damage in a human lymphoblastoid cell line.

PubMed

Hornhardt, Sabine; Gomolka, Maria; Walsh, Linda; Jung, Thomas

2006-08-30

In the field of radiation protection the combined exposure to radiation and other toxic agents is recognised as an important research area. To elucidate the basic mechanisms of simultaneous exposure, the interaction of the carcinogens and environmental toxicants cadmium and two arsenic compounds, arsenite and arsenic trioxide, in combination with gamma-radiation in human lymphoblastoid cells (TK6) were investigated. Gamma-radiation induced significant genotoxic effects such as micronuclei formation, DNA damage and apoptosis, whereas arsenic and cadmium had no significant effect on these indicators of cellular damage at non-toxic concentrations. However, in combination with gamma-radiation arsenic trioxide induced a more than additive apoptotic rate compared to the sum of the single effects. Here, the level of apoptotic cells was increased, in a dose-dependent way, up to two-fold compared to the irradiated control cells. Arsenite did not induce a significant additive effect at any of the concentrations or radiation doses tested. On the other hand, arsenic trioxide was less effective than arsenite in the induction of DNA protein cross-links. These data indicate that the two arsenic compounds interact through different pathways in the cell. Cadmium sulphate, like arsenite, had no significant effect on apoptosis in combination with gamma-radiation at low concentrations and, at high concentrations, even reduced the radiation-induced apoptosis. An additive effect on micronuclei induction was observed with 1muM cadmium sulphate with an increase of up to 80% compared to the irradiated control cells. Toxic concentrations of cadmium and arsenic trioxide seemed to reduce micronuclei induction. The results presented here indicate that relatively low concentrations of arsenic and cadmium, close to those occuring in nature, may interfere with radiation effects. Differences in action of the two arsenic compounds were identified.

[Geochemical distribution of dissolved bismuth in the Yellow Sea and East China Sea].

PubMed

Wu, Xiao-Dan; Song, Jin-Ming; Wu, Bin; Li, Xue-Gang

2014-01-01

Occurrence level, geochemical distribution of dissolved bismuth and its coupling relationship to eco-environment were investigated in the Yellow Sea and East China Sea to explore the source and influencing factors. The results showed that the concentration of dissolved bismuth was within the range of 0-0. 029 microg x L(-1) at the surface and 0.001-0.189 microg x L(-1) at the bottom, with the averages of 0.008 and 0.016 microg x L(-1), respectively. Horizontally, low value of dissolved bismuth exhibited the bidirectional extension feature, indicating that it could trace the path of Changjiang Diluted Water. High value of dissolved bismuth was observed where the Subei Costal Current and Yellow Sea Warm Current flowed and the Changjiang Diluted Water and Zhejiang-Fujian Coastal Current met, suggesting that it was controlled by the cycle of current system. Vertically, the coastal water was fully mixed by water convection and eddy mixing, and was divided from the stratified water by strong tidal front, which blocked the transport of dissolved bismuth to the open sea. Thus, the concentration in front area was significantly higher than that in the open sea. Diurnal variation of dissolved bismuth was related to the hydrodynamic conditions (tide, suspension and thermocline) instead of the environmental factors (temperature and salinity). Positive relationship to SPM (suspended particulate matter) clarified that bismuth was prone to release from solid phase to liquid phase. Furthermore, conditions with temperature ranging 22-27 degrees C, salinity ranging 28-31 and pH ranging 7.9-8.1 were shown to be optimal for the release process.

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS... pretreatment standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process... (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010...

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS... pretreatment standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process... (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010...

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS). Except as... standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process wastewater... million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010 0.005 (b...

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS... pretreatment standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process... (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010...

40 CFR 471.15 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Tin-Bismuth Forming Subcategory § 471.15 Pretreatment standards for new sources (PSNS). Except as... standards for new sources. The mass of wastewater pollutants in lead-tin-bismuth forming process wastewater... million off-pounds) of lead-tin-bismuth rolled with emulsions Antimony 0.067 0.030 Lead 0.010 0.005 (b...

75 FR 14491 - Listing of Color Additives Exempt From Certification; Bismuth Citrate

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-26

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 73 [Docket No. FDA-2008-C-0098] Listing of Color Additives Exempt From Certification; Bismuth Citrate AGENCY: Food... amending the color additive regulations to increase the permitted use level of bismuth citrate as a color...

The cytotoxicity of organobismuth compounds with certain molecular structures can be diminished by replacing the bismuth atom with an antimony atom in the molecules.

PubMed

Kohri, Kumiko; Yoshida, Eiko; Yasuike, Shuji; Fujie, Tomoya; Yamamoto, Chika; Kaji, Toshiyuki

2015-06-01

Organic-inorganic hybrid molecules, which are composed of an organic structure and metal(s), are indispensable for synthetic chemical reactions; however, their toxicity has been incompletely understood. In the present study, we discovered two cytotoxic organobismuth compounds whose cytotoxicity diminished upon replacement of the intramolecular bismuth atom with an antimony atom. The intracellular accumulation of the organobismuth compounds was much higher than that of the organoantimony compounds with the corresponding organic structures. We also showed that both the organic structure and bismuth atom are required for certain organobismuth compounds to exert their cytotoxic effect, suggesting that the cytotoxicity of such a compound is a result of an interaction between the organic structure and the bismuth atom. The present data suggest that organobismuth compounds with certain molecular structures exhibit cytotoxicity via an interaction between the molecular structure and the bismuth atom, and this cytotoxicity can be diminished by replacing the bismuth atom with an antimony atom, resulting in lower intracellular accumulation.

NTP Toxicology and Carcinogenesis Studies of Molybdenum Trioxide (CAS No. 1313-27-5) in F344 Rats and B6C3F1 Mice (Inhalation Studies).

PubMed

1997-04-01

Molybdenum is an essential element for the function of nitrogenase in plants and as a cofactor for enzymes including xanthine oxidoreductase, aldehyde oxidase, and sulfide oxidase in animals. Molybdenum trioxide is used primarily as an additive to steel and corrosion-resistant alloys. It is also used as a chemical intermediate for molybdenum products; an industrial catalyst; a pigment; a crop nutrient; components of glass, ceramics, and enamels; a flame retardant for polyester and polyvinyl chloride resins; and a reagent in chemical analyses. Molybdenum trioxide was nominated by the NCI for toxicity and carcinogenicity studies as a representative inorganic molybdenum compound. The production of molybdenum trioxide is the largest of all the molybdenum compounds examined. Male and female F344/N rats and B6C3F1 mice were exposed to molybdenum trioxide (approximately 99% pure) by inhalation for 14 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and cultured Chinese hamster ovary cells. 14-DAY STUDY IN RATS: Groups of five male and five female F344/N rats were exposed to 0, 3, 10, 30, 100, or 300 mg molybdenum trioxide/m(3). Rats were exposed for 6 hours per day, 5 days per week, for a total of 10 exposure days during a 14-day period. All rats survived to the end of the study. The final mean body weights of male rats exposed to 100 mg/m(3) and male and female rats exposed to 300 mg/m(3) were significantly lower than those of the control groups. Male rats exposed to 300 mg/m(3) lost weight during the study. There were no clinical findings related to exposure to molybdenum trioxide. No chemical-related lesions were observed. 14-DAY STUDY IN MICE: Groups of five male and five female B6C3F1 mice were exposed to 0, 3, 10, 30, 100, or 300 mg molybdenum trioxide/m(3). Mice were exposed 6 hours per day, 5 days per week, for a total of 10 exposure days during a 14-day period. All mice survived to the end of the study. Final mean body weights of male and female mice exposed to 300 mg/m(3) were significantly lower than those of the control groups. Male mice exposed to 300 mg/m(3) lost weight during the study. There were no clinical findings related to exposure to molybdenum trioxide. No chemical-related lesions were observed. 13-WEEK STUDY IN RATS: Groups of 10 male and 10 female F344/N rats were exposed to molybdenum trioxide by inhalation at concentrations of 0, 1, 3, 10, 30, or 100 mg/m(3) for 6.5 hours per day, 5 days per week, for 13 weeks. All rats survived to the end of the study. The final mean body weights of exposed rats were similar to those of the control groups. No clinical findings related to molybdenum trioxide exposure were observed. There were no significant chemical-related differences in absolute or relative organ weights, hematology or clinical chemistry parameters, sperm counts or motility, or liver copper concentrations between control and exposed rats. No chemical-related lesions were observed. 13-WEEK STUDY IN MICE: Groups of 10 male and 10 female B6C3F1 mice were exposed to molybdenum trioxide by inhalation at concentrations of 0, 1, 3, 10, 30, or 100 mg/m(3) for 6.5 hours per day, 5 days per week, for 13 weeks. All mice survived to the end of the study. The final mean body weights of exposed mice were similar to those of the control groups. There were no chemical-related clinical findings. There were no significant differences in absolute or relative organ weights or sperm counts or motility between control and exposed mice. There were significant increases in liver copper concentrations in female mice exposed to 30 mg/m(3) and in male and female mice exposed to 100 mg/m(3) compared to those of the control groups. No chemical-related lesions were observed. 2-YEAR STUDIES IN RATS: Groups of 50 male and 50 female F344/N rats were exposed to molybdenum trioxide by inhalation at concentrations of 0, 10, 30, or 100 mg/m(3). Rats were exposed for 6 hours per day, 5 days per week, for 106 weeks. Survival, Body Weights, and Special Studies: Survival rates of exposed maleed male and female rats were similar to those of the control groups. Mean body weights of exposed groups of male and female rats were similar to those of the control groups throughout the study. There was a significant exposure-dependent increase in blood molybdenum concentration in exposed rats. Blood concentrations of molybdenum in exposed male rats were greater than those in exposed female rats. There were no toxicologically significant differences in bone density or curvature between control and exposed rats. Pathology Findings: The incidences of alveolar/bronchiolar adenoma or carcinoma (combined) were increased in male rats with a marginally significant positive trend. No increase in the incidences of lung neoplasms occurred in female rats. Incidences of chronic alveolar inflammation in male and female rats exposed to 30 or 100 mg/m(3) were significantly greater than those in the control groups. No nasal or laryngeal neoplasms were attributed to exposure to molybdenum trioxide. Incidences of hyaline degeneration in the nasal respiratory epithelium in 30 and 100 mg/m(3) males and in all exposed groups of females were significantly greater than those in the control groups. The incidences of hyaline degeneration in the nasal olfactory epithelium of all exposed groups of females were significantly greater than that in the control group. In the larynx, incidences of squamous metaplasia of the epithelium lining the base of the epiglottis in all exposed groups of male and female rats were significantly greater than those in the control groups and increased with increasing exposure concentration. 2-YEAR STUDY IN MICE: Groups of 50 male and 50 female B6C3F1 mice were exposed to molybdenum trioxide by inhalation at concentrations of 0, 10, 30, or 100 mg/m(3). Mice were exposed for 6 hours per day, 5 days per week, for 105 weeks. Survival, Body Weights, and Special Studies: The survival rate of male mice exposed to 30 mg/m(3) was marginally lower than that of the control group; survival rates of 10 and 100 mg/m(3) males and of all exposed groups of females were similar to those of the control groups. Mean body weights of exposed male mice were generally similar to those of the control group throughout the study. Mean body weights of exposed female mice were generally greater than those of the control group from week 11 until the end of the study. There was a significant exposure-dependent increase in blood molybdenum concentration in exposed mice. There were no toxicologically significant differences in bone density or curvature between control and exposed mice. Pathology Findings: The incidences of alveolar/bronchiolar carcinoma in all exposed groups of males were significantly greater than that in the control group. Incidences of alveolar/bronchiolar adenoma in females in the 30 and 100 mg/m(3) groups were significantly greater than that in the control group. Incidences of alveolar/bronchiolar adenoma or carcinoma (combined) in 10 and 30 mg/m(3) males and in 100 mg/m(3) females were significantly greater than those in the control groups and exceeded the historical control ranges for 2-year NTP inhalation studies. Incidences of metaplasia of the alveolar epithelium of minimal severity in the centriacinar region of the lung were significantly increased in all exposed groups of mice. The incidences of histiocyte cellular infiltration in all exposed groups of males were significantly greater than that in the control group. Incidences of hyaline degeneration of the respiratory epithelium of the nasal cavity in 100 mg/m(3) males and females and hyaline degeneration of the olfactory epithelium of the nasal cavity in 100 mg/m(3) females were significantly greater than those in the control groups. The incidences of squamous metaplasia of the epithelium lining the base of the epiglottis were significantly increased in all exposed groups of males and females. In both male and female mice, the incidences of hyperplasia of the laryngeal epithelium in level II of the larynx increased with increasing exposure concentration. The increase was statistically significant only in mice exposed to 100 mg/m(3) with 82% of male and 70% of female mice affected. GENETIC TOXICOLOGY: Molybdenum trioxide was not mutagenic in any of five strains of Salmonella typhimurium, and it did not induce sister chromatid exchanges or chromosomal aberrations in cultured Chinese hamster ovary cells in vitro. All tests were conducted with and without S9 metabolic activation enzymes. CONCLUSIONS: Under the conditions of these 2-year inhalation studies, there was equivocal evidence of carcinogenic activity of molybdenum trioxide in male F344/N rats based on a marginally significant positive trend of alveolar/bronchiolar adenoma or carcinoma (combined). There was no evidence of carcinogenic activity of molybdenum trioxide in female F344/N rats exposed to 10, 30, or 100 mg/m(3). There was some evidence of carcinogenic activity of molybdenum trioxide in male B6C3F1 mice based on increased incidences of alveolar/bronchiolar carcinoma and adenoma or carcinoma (combined). There was some evidence of carcinogenic activity of molybdenum trioxide in female B6C3F1 mice based on increased incidences of alveolar/bronchiolar adenoma and adenoma or carcinoma (combined). Exposure of male and female rats to molybdenum trioxide by inhalation resulted in increased incidences of chronic alveolar inflammation, hyaline degeneration of the respiratory epithelium, hyaline degeneration of the olfactory epithelium (females), and squamous metaplasia of the epiglottis. Exposure of male and female mice to molybdenum trioxide by inhalation resulted in increased incidences of metaplasia of the alveolar epithelium, histiocyte cellular infiltration (males), hyaline degeneration of the respiratory epithelium, hyaline degeneration of the olfactory epithelium (females), squamous metaplasia of the epiglottis, and hyperplasia of the larynx. Synonyms: Molybdic oxide; molybdic trioxide; molybdic anhydride; molybdenum (VI) oxide; molybdenum peroxide; molybdic acid anhydride; molybdenum anhydride; natural molybdite; molybdena

Helicobacter pylori second-line rescue therapy with levofloxacin- and bismuth-containing quadruple therapy, after failure of standard triple or non-bismuth quadruple treatments.

PubMed

Gisbert, J P; Romano, M; Gravina, A G; Solís-Muñoz, P; Bermejo, F; Molina-Infante, J; Castro-Fernández, M; Ortuño, J; Lucendo, A J; Herranz, M; Modolell, I; Del Castillo, F; Gómez, J; Barrio, J; Velayos, B; Gómez, B; Domínguez, J L; Miranda, A; Martorano, M; Algaba, A; Pabón, M; Angueira, T; Fernández-Salazar, L; Federico, A; Marín, A C; McNicholl, A G

2015-04-01

The most commonly used second-line Helicobacter pylori eradication regimens are bismuth-containing quadruple therapy and levofloxacin-containing triple therapy, both offering suboptimal results. Combining bismuth and levofloxacin may enhance the efficacy of rescue eradication regimens. To evaluate the efficacy and tolerability of a second-line quadruple regimen containing levofloxacin and bismuth in patients whose previous H. pylori eradication treatment failed. This was a prospective multicenter study including patients in whom a standard triple therapy (PPI-clarithromycin-amoxicillin) or a non-bismuth quadruple therapy (PPI-clarithromycin-amoxicillin-metronidazole, either sequential or concomitant) had failed. Esomeprazole (40 mg b.d.), amoxicillin (1 g b.d.), levofloxacin (500 mg o.d.) and bismuth (240 mg b.d.) was prescribed for 14 days. Eradication was confirmed by (13) C-urea breath test. Compliance was determined through questioning and recovery of empty medication envelopes. Incidence of adverse effects was evaluated by questionnaires. 200 patients were included consecutively (mean age 47 years, 67% women, 13% ulcer). Previous failed therapy included: standard clarithromycin triple therapy (131 patients), sequential (32) and concomitant (37). A total of 96% took all medications correctly. Per-protocol and intention-to-treat eradication rates were 91.1% (95%CI = 87-95%) and 90% (95%CI = 86-94%). Cure rates were similar regardless of previous (failed) treatment or country of origin. Adverse effects were reported in 46% of patients, most commonly nausea (17%) and diarrhoea (16%); 3% were intense but none was serious. Fourteen-day bismuth- and levofloxacin-containing quadruple therapy is an effective (≥90% cure rate), simple and safe second-line strategy in patients whose previous standard triple or non-bismuth quadruple (sequential or concomitant) therapies have failed. © 2015 John Wiley & Sons Ltd.

Effect of absorption recovery in bismuth-doped silica glass at 1450 nm on soliton grouping in fiber laser

PubMed Central

Gumenyuk, R.; Melkumov, M. A.; Khopin, V. F.; Dianov, E. M.; Okhotnikov, O. G.

2014-01-01

Saturable absorption in bismuth-doped glasses was found to have a noticeable influence on soliton interaction and group formation. This phenomenon, observed in 1450 nm mode-locked bismuth-doped fiber laser, shows the distinct feature of the multiple pulse regime, which appears as a stationary pulse group whose length can be spread over the whole cavity length by variation of the pump power and polarization. Pulse positioning within the ensemble depends on the saturation fluence and the relatively fast recovery dynamics of bismuth fiber. PMID:25391808

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jena, Puru; Kandalam, Anil K.; Christian, Theresa M.

Gallium phosphide bismide (GaP1-xBix) epilayers with bismuth fractions from 0.9% to 3.2%, as calculated from lattice parameter measurements, were studied with Rutherford backscattering spectrometry (RBS) to directly measure bismuth incorporation. The total bismuth fractions found by RBS were higher than expected from the lattice parameter calculations. Furthermore, in one analyzed sample grown by molecular beam epitaxy at 300 degrees C, 55% of incorporated bismuth was found to occupy interstitial sites. We discuss implications of this high interstitial incorporation fraction and its possible relationship to x-ray diffraction and photoluminescence measurements of GaP0.99Bi0.01.

Study of the structure, dielectric and ferroelectric behavior of BaBi{sub 4+δ}Ti{sub 4}O{sub 15} ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khokhar, Anita, E-mail: mails4anita@gmail.com, E-mail: goyalphy@gmail.com; Goyal, Parveen K., E-mail: mails4anita@gmail.com, E-mail: goyalphy@gmail.com; Sreenivas, K.

2016-05-23

The structure and ferroelectric properties of excess bismuth doped barium bismuth titanate BaBi{sub 4+δ}Ti{sub 4}O{sub 15} (δ = 2 - 10 wt.%)) ceramics prepared by solid-state reaction method have been investigated. X-ray diffraction (XRD) confirms the formation of a single phase material with a change in the orthorhombic distortion with varying excess of bismuth content. There is no change in the phase transition temperature (T{sub m}) while the relaxor behaviour has been modified significantly with excess of bismuth doping. Saturated hysteresis loops with high remnant polarization (P{sub r} ~ 12.5  µC/cm{sup 2}), low coercive fields (E{sub c} ~ 26 kV/cm) aremore » measured and a high piezoelectric coefficient (d{sub 33} ~ 29 pC/N) is achieved in poled BaBi{sub 4}Ti{sub 4}O{sub 15} ceramics prepared with up to 8 wt.% of excess bismuth oxide. The improvement in the ferroelectric properties with increase in the excess bismuth content in BaBi{sub 4}Ti{sub 4}O{sub 15} ceramics has been explained in terms of changing oxygen vacancy concentration and structural relaxation. Tunable ferroelectric materials can be obtained by manipulating the doping amount of excess bismuth.« less

The efficacy of ranitidine bismuth citrate, amoxicillin and doxycycline or tetracycline regimens as a first line treatment for Helicobacter pylori eradication.

PubMed

Akyildiz, Murat; Akay, Sinan; Musoglu, Ahmet; Tuncyurek, Muge; Aydin, Ahmet

2009-01-01

The eradication rates of Helicobacter pylori (H. pylori) clearly decreased with standard PPI-based triple therapies. To assess the efficacy of two different triple therapies consisting of ranitidine bismuth citrate-amoxicillin-doxycycline and ranitidine bismuth citrate-amoxicillin-tetracycline combinations as a first line treatment option. One hundred and fifteen consecutive dyspeptic patients in whom H. pylori infection was diagnosed for the first time were enrolled in this study. The patients were randomized into two groups. Group 1 (n=57) was assigned to receive a 14-day triple therapy consisting of ranitidine bismuth citrate 400 mg (b.i.d.), amoxicillin 1 g (b.i.d) and doxycycline 100 mg (b.i.d.). Group 2 (n=58) was assigned to receive a 14-day triple therapy consisting of ranitidine bismuth citrate 400 mg (b.i.d.), amoxicillin 1 g (b.i.d.) and tetracycline 500 mg (q.i.d.). The eradication was achieved in 45.7% (21/46) and 40.8% (20/49) of the patients in group 1 and group 2, according to per protocol analysis. The intention-to-treat eradication rates were 36.8% (21/57) and 34.5% (20/58) in group 1 and group 2, respectively. Two-week therapy with neither ranitidine bismuth citrate-amoxicillin-doxycycline nor ranitidine bismuth citrate-amoxicillin-tetracycline is adequately effective for H. pylori eradication as a first line therapy.

Effect of silver nanoparticles on the fluorescence of Pb2+ and compositional dependence of Sm3+ fluorescence in borate glasses

NASA Astrophysics Data System (ADS)

Olumoroti, Akinloluwa T.

Borate glasses have been widely studied due to their good optical and mechanical properties. Lead and bismuth (PbO/Bi2O 3:B2O3) borate glasses belong to a family of heavy metal oxide (HMO) glasses which are well known to be chemically durable, stable against atmospheric moisture, have low melting temperatures and good corrosion resistance. The first part of this work deals with lead borate glasses with silver nanoparticles (NPs) introduced into the glass matrix. Transmission electron microscopy characterization is done to verify the nucleation of NPs. Fluorescence and optical absorption experiments are then carried out after different heat treatment duration to investigate the influence of silver NPs on the optical properties of lead (Pb2+) by comparing with a glass sample without silver NPs. Optical absorption experiments show that a well-defined surface plasmon resonance (SPR) peak due to Ag NPs can be observed only for samples that were annealed for 36 hrs. Pb2+ fluorescence spectra reveal that the presence of silver NPs creates new emission centers for Pb2+ ions by altering their chemical environment. The second part of the work involves the use of samarium (a rare earth ion) as a dopant in lead and bismuth borate glasses. The concentration of samarium (Sm3+) is fixed and the base glass composition is varied. The goal is to investigate the compositional dependence of optical properties of samarium in the base glass (PbO/Bi2O3:B 2O3). Optical absorption spectra have been collected and the oscillator strength of each transition - including the hypersensitive - is obtained. The Optical absorption edge is found to shift toward lower energies with increasing PbO/Bi2O3 concentration. Both the oscillator strength and the peak position of the hypersensitive transition show significant variation with glass composition. Strong interaction between Sm3+ ions and Pb2+/Bi3+ ions can also be seen from the variations in the fluorescence emission properties of Sm3+ as a function of base glass composition. Studying the variation of these optical properties will help to create the optimum rare-earth ion-host configuration for possible technological applications. This is the thrust of our future investigations of these glass systems. Keywords: Borate glasses, nanoparticles, fluorescence, transmission electron microscopy, optical absorption, surface plasmon resonance, rare-earth (RE) ions, oscillator strength, hypersensitive transition (HST).

Optical properties and mechanisms in Cr3+, Bi3+-codoped oxide-based spinel nanoparticles

NASA Astrophysics Data System (ADS)

Pellerin, Morgane; Coelho-Diogo, Cristina; Bonhomme, Christian; Touatib, Nadia; Binet, Laurent; Gourier, Didier; Ueda, Jumpei; Tanabe, Setsuhisa; Viana, Bruno; Chanéac, Corinne

2017-02-01

At the nanoscale, the ZnGa2O4 spinel doped with chromium (III) is an interesting material for in vivo optical imaging due to its bright red persistent luminescence after UV and visible excitation. Moreover its persistent luminescent properties can be improved with the incorporation of bismuth (III) as a co-dopant without any structure changes. The nanoparticles are synthesized by soft chemistry using microwave heating in aqueous media. These very small sized nanophosphors (around 10 nm) present interesting long lasting persistent luminescence after annealing at 1000°C and they can be excited both under UV and under visible LED excitation. In this work we try to understand the mechanisms of the persistent luminescent properties of such nanomaterials. Thermoluminescence is performed to investigate trapping and detrapping processes as well as trap distribution. The chromium local environment is studied by Electron Paramagnetic Resonance. 71Ga Nuclear Magnetic Resonance is used to get information on the gallium ions repartition (tetrahedral or octahedral site) in the structure. Comparison of optical properties versus local structure increases the understanding of the persistent luminescence mechanism and gives insights to the new modalities for their use as nanoprobes for in vivo imaging.

Synthesis of cross-linked chitosan modified with the glycine moiety for the collection/concentration of bismuth in aquatic samples for ICP-MS determination.

PubMed

Oshita, Koji; Noguchi, Osamu; Oshima, Mitsuko; Motomizu, Shoji

2007-10-01

A chelating resin, cross-linked chitosan modified with the glycine moiety (glycine-type chitosan resin), was developed for the collection and concentration of bismuth in aquatic samples for ICP-MS measurements. The adsorption behavior of bismuth and 55 elements on glycine-type chitosan resin was systematically examined by passing a sample solution containing 56 elements through a mini-column packed with the resin (wet volume; 1 ml). After eluting the elements adsorbed on the resin with nitric acid, the eluates were measured by ICP-MS. The glycine-type chitosan resin could adsorb several cations by a chelating mechanism and several oxoanions by an anion-exchange mechanism. Especially, the resin could adsorb almost 100% Bi(III) over a wide pH region from pH 2 to 6. Bismuth could be strongly adsorbed at pH 3, and eluted quantitatively with 10 ml of 3 M nitric acid. A column pretreatment method with the glycine-type chitosan resin was used prior to removal of high concentrations of matrices in a seawater sample and the preconcentration of trace bismuth in river water samples for ICP-MS measurements. The column pretreatment method was also applied to the determination of bismuth in real samples by ICP-MS. The LOD of bismuth was 0.1 pg ml(-1) by 10-fold column preconcentration for ICP-MS measurements. The analytical results for bismuth in sea and river water samples by ICP-MS were 22.9 +/- 0.5 pg ml(-1) (RSD, 2.2%) and 2.08 +/- 0.05 pg ml(-1) (RSD, 2.4%), respectively.

Mineral trioxide aggregate enhances the odonto/osteogenic capacity of stem cells from inflammatory dental pulps via NF-κB pathway.

PubMed

Wang, Y; Yan, M; Fan, Z; Ma, L; Yu, Y; Yu, J

2014-10-01

This study was designed to investigate the effects of mineral trioxide aggregate (MTA) on the osteo/odontogenic differentiation of inflammatory dental pulp stem cells (iDPSCs). inflammatory DPSCs were isolated from the inflammatory pulps of rat incisors and cocultured with MTA-conditioned medium. MTT assay and flow cytometry were performed to evaluate the proliferation of iDPSCs. Alkaline phosphatase (ALP) activity, alizarin red staining, real-time RT-PCR, and Western blot assay were used to investigate the differentiation capacity as well as the involvement of NF-κB pathway in iDPSCs. Mineral trioxide aggregate-treated iDPSCs demonstrated the higher ALP activity and formed more mineralized nodules than the untreated group. The odonto/osteoblastic markers (Alp, Runx2/RUNX2, Osx/OSX, Ocn/OCN, and Dspp/DSP, respectively) in MTA-treated iDPSCs were significantly upregulated as compared with untreated iDPSCs. Mechanistically, cytoplastic phos-P65 and nuclear P65 in MTA-treated iDPSCs were significantly increased in a time-dependent manner. Moreover, the inhibition of NF-κB pathway suppressed the MTA-induced odonto/osteoblastic differentiation of iDPSCs, as indicated by decreased ALP levels, weakened mineralization capacity and downregulated levels of odonto/osteoblastic genes (Osx, Ocn, and Dspp). Mineral trioxide aggregate enhances the odonto/osteogenic capacity of DPSCs from inflammatory sites via activating the NF-κB pathway. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Electronic bandstructure of semiconductor dilute bismide structures

NASA Astrophysics Data System (ADS)

Erucar, T.; Nutku, F.; Donmez, O.; Erol, A.

2017-02-01

In this work electronic band structure of dilute bismide GaAs/GaAs1-xBix quantum well structures with 1.8% and 3.75% bismuth compositions have been investigated both experimentally and theoretically. Photoluminescence (PL) measurements reveal that effective bandgap of the samples decreases approximately 65 meV per bismuth concentration. Temperature dependence of the effective bandgap is obtained to be higher for the sample with higher bismuth concentration. Moreover, both asymmetric characteristic at the low energy tail of the PL and full width at half maximum (FWHM) of PL peak increase with increasing bismuth composition as a result of increased Bi related defects located above valence band (VB). In order to explain composition dependence of the effective bandgap quantitatively, valence band anti-crossing (VBAC) model is used. Bismuth composition and temperature dependence of effective bandgap in a quantum well structure is modeled by solving Schrödinger equation and compared with experimental PL data.

Element Distribution in the Oxygen-Rich Side-Blow Bath Smelting of a Low-Grade Bismuth-Lead Concentrate

NASA Astrophysics Data System (ADS)

Yang, Tianzu; Xiao, Hui; Chen, Lin; Chen, Wei; Liu, Weifeng; Zhang, Duchao

2018-03-01

Oxygen-rich side-blow bath smelting (OSBS) technology offers an efficient method for processing complex bismuth-lead concentrates; however, the element distributions in the process remain unclear. This work determined the distributions of elements, i.e., bismuth, lead, silver, copper, arsenic and antimony, in an industrial-scale OSBS process. The feed, oxidized slag and final products were collected from the respective sampling points and analyzed. For the oxidative smelting process, 65% of bismuth and 76% of silver in the concentrate report to the metal alloy, whereas less lead reports to the metal ( 31%) than the oxidized slag ( 44%). Approximately 50% of copper enters the matte, while more than 63% of arsenic and antimony report to the slag. For the reductive smelting process, less than 4.5% of bismuth, lead, silver and copper in the oxidized slag enter the reduced slag, indicating high recoveries of these metal values.

Element Distribution in the Oxygen-Rich Side-Blow Bath Smelting of a Low-Grade Bismuth-Lead Concentrate

NASA Astrophysics Data System (ADS)

Yang, Tianzu; Xiao, Hui; Chen, Lin; Chen, Wei; Liu, Weifeng; Zhang, Duchao

2018-06-01

Oxygen-rich side-blow bath smelting (OSBS) technology offers an efficient method for processing complex bismuth-lead concentrates; however, the element distributions in the process remain unclear. This work determined the distributions of elements, i.e., bismuth, lead, silver, copper, arsenic and antimony, in an industrial-scale OSBS process. The feed, oxidized slag and final products were collected from the respective sampling points and analyzed. For the oxidative smelting process, 65% of bismuth and 76% of silver in the concentrate report to the metal alloy, whereas less lead reports to the metal ( 31%) than the oxidized slag ( 44%). Approximately 50% of copper enters the matte, while more than 63% of arsenic and antimony report to the slag. For the reductive smelting process, less than 4.5% of bismuth, lead, silver and copper in the oxidized slag enter the reduced slag, indicating high recoveries of these metal values.

Nano lead oxide and epdm composite for development of polymer based radiation shielding material: Gamma irradiation and attenuation tests

NASA Astrophysics Data System (ADS)

Özdemir, T.; Güngör, A.; Akbay, I. K.; Uzun, H.; Babucçuoglu, Y.

2018-03-01

It is important to have a shielding material that is not easily breaking in order to have a robust product that guarantee the radiation protection of the patients and radiation workers especially during the medical exposure. In this study, nano sized lead oxide (PbO) particles were used, for the first time, to obtain an elastomeric composite material in which lead oxide nanoparticles, after the surface modification with silane binding agent, was used as functional material for radiation shielding. In addition, the composite material including 1%, 5%, 10%, 15% and 20% weight percent nano sized lead oxide was irradiated with doses of 81, 100 and 120 kGy up to an irradiation period of 248 days in a gamma ray source with an initial dose rate of 21.1 Gy/h. Mechanical, thermal properties of the irradiated materials were investigated using DSC, DMA, TGA and tensile testing and modifications in thermal and mechanical properties of the nano lead oxide containing composite material via gamma irradiation were reported. Moreover, effect of bismuth-III oxide addition on radiation attenuation of the composite material was investigated. Nano lead oxide and bismuth-III oxide particles were mixed with different weight ratios. Attenuation tests have been conducted to determine lead equivalent values for the developed composite material. Lead equivalent thickness values from 0.07 to 0.65 (2-6 mm sample thickness) were obtained.

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2014 CFR

2014-07-01

... SOURCE CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

...-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of effluent... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

...-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of effluent... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

40 CFR 471.12 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.12 Effluent limitations representing the degree of... average mg/off-kg (pounds per million off-pounds) of lead-tin-bismuth rolled with emulsion Antimony 0.067... lead-tin-bismuth rolled with soap solutions Antimony 0.120 0.055 Lead 0.018 0.009 (c) Drawing spent...

Build-up enhancement of photoluminescence from phenylazomethine bismuth dendrimer using Bi(OTf)3

NASA Astrophysics Data System (ADS)

Kambe, Tetsuya; Imaoka, Shotaro; Imaoka, Takane; Yamamoto, Kimihisa

2018-05-01

Metal assembly to a dendrimer can provide various functionalities based on the branched structure. Here, we researched assembly phenomena of bismuth salts in the phenylazomethine dendrimer and achieved enhancement of emission intensity per metal unit by using Bi(OTf)3. This enhancement suggested increasing of Bi-N coordination bonds derived from the bismuth units in the dendrimer.

Computational chemistry calculations of stability for bismuth nanotubes, fullerene-like structures and hydrogen-containing nanostructures.

PubMed

Kharissova, Oxana V; Osorio, Mario; Vázquez, Mario Sánchez; Kharisov, Boris I

2012-08-01

Using molecular mechanics (MM+), semi-empirical (PM6) and density functional theory (DFT) (B3LYP) methods we characterized bismuth nanotubes. In addition, we predicted the bismuth clusters {Bi(20)(C(5V)), Bi(24)(C(6v)), Bi(28)(C(1)), B(32)(D(3H)), Bi(60)(C(I))} and calculated their conductor properties.

Increased InAs quantum dot size and density using bismuth as a surfactant

NASA Astrophysics Data System (ADS)

Dasika, Vaishno D.; Krivoy, E. M.; Nair, H. P.; Maddox, S. J.; Park, K. W.; Jung, D.; Lee, M. L.; Yu, E. T.; Bank, S. R.

2014-12-01

We have investigated the growth of self-assembled InAs quantum dots using bismuth as a surfactant to control the dot size and density. We find that the bismuth surfactant increases the quantum dot density, size, and uniformity, enabling the extension of the emission wavelength with increasing InAs deposition without a concomitant reduction in dot density. We show that these effects are due to bismuth acting as a reactive surfactant to kinetically suppress the surface adatom mobility. This mechanism for controlling quantum dot density and size has the potential to extend the operating wavelength and enhance the performance of various optoelectronic devices.

Composition for radiation shielding

DOEpatents

Kronberg, J.W.

1994-08-02

A composition for use as a radiation shield is disclosed. The shield has a depleted uranium core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container. 2 figs.

Topological Insulator State in Thin Bismuth Films Subjected to Plane Tensile Strain

NASA Astrophysics Data System (ADS)

Demidov, E. V.; Grabov, V. M.; Komarov, V. A.; Kablukova, N. S.; Krushel'nitskii, A. N.

2018-03-01

The results of experimental examination of galvanomagnetic properties of thin bismuth films subjected to plane tensile strain resulting from the difference in thermal expansion coefficients of the substrate material and bismuth are presented. The resistivity, the magnetoresistance, and the Hall coefficient were studied at temperatures ranging from 5 to 300 K in magnetic fields as strong as 0.65 T. Carrier densities were calculated. A considerable increase in carrier density in films thinner than 30 nm was observed. This suggests that surface states are more prominent in thin bismuth films on mica substrates, while the films themselves may exhibit the properties of a topological insulator.

Oxidation mechanism of formic acid on the bismuth adatom-modified Pt(111) surface.

PubMed

Perales-Rondón, Juan Victor; Ferre-Vilaplana, Adolfo; Feliu, Juan M; Herrero, Enrique

2014-09-24

In order to improve catalytic processes, elucidation of reaction mechanisms is essential. Here, supported by a combination of experimental and computational results, the oxidation mechanism of formic acid on Pt(111) electrodes modified by the incorporation of bismuth adatoms is revealed. In the proposed model, formic acid is first physisorbed on bismuth and then deprotonated and chemisorbed in formate form, also on bismuth, from which configuration the C-H bond is cleaved, on a neighbor Pt site, yielding CO2. It was found computationally that the activation energy for the C-H bond cleavage step is negligible, which was also verified experimentally.

Composition for radiation shielding

DOEpatents

Kronberg, James W.

1994-01-01

A composition for use as a radiation shield. The shield has a depleted urum core for absorbing gamma rays and a bismuth coating for preventing chemical corrosion and absorbing gamma rays. Alternatively, a sheet of gadolinium may be positioned between the uranium core and the bismuth coating for absorbing neutrons. The composition is preferably in the form of a container for storing materials that emit radiation such as gamma rays and neutrons. The container is preferably formed by casting bismuth around a pre-formed uranium container having a gadolinium sheeting, and allowing the bismuth to cool. The resulting container is a structurally sound, corrosion-resistant, radiation-absorbing container.

Bismuth oxyhalide nanomaterials: layered structures meet photocatalysis

NASA Astrophysics Data System (ADS)

Li, Jie; Yu, Ying; Zhang, Lizhi

2014-07-01

In recent years, layered bismuth oxyhalide nanomaterials have received more and more interest as promising photocatalysts because their unique layered structures endow them with fascinating physicochemical properties; thus, they have great potential photocatalytic applications for environment remediation and energy harvesting. In this article, we explore the synthesis strategies and growth mechanisms of layered bismuth oxyhalide nanomaterials, and propose design principles of tailoring a layered configuration to control the nanoarchitectures for high efficient photocatalysis. Subsequently, we focus on their layered structure dependent properties, including pH-related crystal facet exposure and phase transformation, facet-dependent photoactivity and molecular oxygen activation pathways, so as to clarify the origin of the layered structure dependent photoreactivity. Furthermore, we summarize various strategies for modulating the composition and arrangement of layered structures to enhance the photoactivity of nanostructured bismuth oxyhalides via internal electric field tuning, dehalogenation effect, surface functionalization, doping, plasmon modification, and heterojunction construction, which may offer efficient guidance for the design and construction of high-performance bismuth oxyhalide-based photocatalysis systems. Finally, we highlight some crucial issues in engineering the layered-structure mediated properties of bismuth oxyhalide photocatalysts and provide tentative suggestions for future research on increasing their photocatalytic performance.

Dynamics of direct X-ray detection processes in high-Z Bi2O3 nanoparticles-loaded PFO polymer-based diodes

NASA Astrophysics Data System (ADS)

Ciavatti, A.; Cramer, T.; Carroli, M.; Basiricò, L.; Fuhrer, R.; De Leeuw, D. M.; Fraboni, B.

2017-10-01

Semiconducting polymer based X-ray detectors doped with high-Z nanoparticles hold the promise to combine mechanical flexibility and large-area processing with a high X-ray stopping power and sensitivity. Currently, a lack of understanding of how nanoparticle doping impacts the detector dynamics impedes the optimization of such detectors. Here, we study direct X-ray radiation detectors based on the semiconducting polymer poly(9,9-dioctyfluorene) blended with Bismuth(III)oxide (Bi2O3) nanoparticles (NPs). Pure polymer diodes show a high mobility of 1.3 × 10-5 cm2/V s, a low leakage current of 200 nA/cm2 at -80 V, and a high rectifying factor up to 3 × 105 that allow us to compare the X-ray response of a polymer detector in charge-injection conditions (forward bias) and in charge-collection conditions (reverse bias), together with the impact of NP-loading in the two operation regimes. When operated in reverse bias, the detectors reach the state of the art sensitivity of 24 μC/Gy cm2, providing a fast photoresponse. In forward operation, a slower detection dynamics but improved sensitivity (up to 450 ± 150 nC/Gy) due to conductive gain is observed. High-Z NP doping increases the X-ray absorption, but higher NP loadings lead to a strong reduction of charge-carrier injection and transport due to a strong impact on the semiconductor morphology. Finally, the time response of optimized detectors showed a cut-off frequency up to 200 Hz. Taking advantage of such a fast dynamic response, we demonstrate an X-ray based velocity tracking system.

Volatile molecule PuO 3 observed from subliming plutonium dioxide

NASA Astrophysics Data System (ADS)

Ronchi, C.; Capone, F.; Colle, J. Y.; Hiernaut, J. P.

2000-06-01

Mass spectrometric measurements of effusing vapours over PuO 2 and (U, Pu)O 2 indicate the presence of volatile PuO 3 (g) molecules. The formation of plutonium trioxide vapour is due to a chemical process involving oxygen adsorbed during oxidation of the sample. Although in the examined samples, the fraction of trioxide effusing in vacuo was of the order of 0.02 ppm of the plutonium content, under steady-state oxidation conditions it has been shown that the process can have a relevant effect on the sublimation rate of the dioxide.

Lead-free precussion primer mixes based on metastable interstitial composite (MIC) technology

DOEpatents

Dixon, George P.; Martin, Joe A.; Thompson, Don

1998-01-01

A lead-free percussion primer composition and a percussion cup containing e composition. The lead-free percussion primer composition is comprised of a mixture of about 45 wt % aluminum powder having an outer coating of aluminum oxide and molybdenum trioxide powder or a mixture of about 50 wt % aluminum powder having an outer coating of aluminum oxide and polytetrafluoroethylene powder. The aluminum powder, molybdenum trioxide powder and polytetrafluoroethylene powder has a particle size of 0.1 .mu.m or less, more preferably a particle size of from about 200-500 angstroms.

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the degree of... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

40 CFR 471.11 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... CATEGORY Lead-Tin-Bismuth Forming Subcategory § 471.11 Effluent limitations representing the degree of... lead-tin-bismuth rolled with emulsions Antimony 0.068 0.030 Lead 0.010 0.005 Oil and grease 0.468 0.281... mg/off-kg (pounds per million off-pound) of lead-tin-bismuth rolled with soap solutions Antimony 0...

Heat-Pipe Bismuth Laser; Examination of Laser Action at 4722A in Bismuth Vapor

DTIC Science & Technology

1976-11-01

11, 15(1975). of Type 6p 3 -6p 2 7s in the Bismuth Atomic Spectrum in Intermediate Coupling," Acta Physica Polonica A47, 231(1975). 19. A.N. Nesmeyanov...Calculated Transit n Probabilities and Lifetimes for the First Excited Configuration np (n+l)s in the Neutral As, Sb and Bi Atoms, " Physica Scripta

Using quality control to limit bismuth in copper cathodes

NASA Astrophysics Data System (ADS)

Serrano, John R.; Berger, Dennis; Bridges, Bill

1994-10-01

This article describes quality-control work at Phelps Dodge, undertaken as part of ISO 9003 certification, to better identify and prevent the contamination of copper cathodes by bismuth. It also overviews the implementation of a production control system as well as associated training designed to minimize the possibility of bismuth-contaminated copper progressing beyond the cathode stage to other areas of manufacturing or distribution.

Radiation dose reduction to the breast in thoracic CT: Comparison of bismuth shielding, organ-based tube current modulation, and use of a globally decreased tube current

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Jia; Duan Xinhui; Christner, Jodie A.

2011-11-15

Purpose: The purpose of this work was to evaluate dose performance and image quality in thoracic CT using three techniques to reduce dose to the breast: bismuth shielding, organ-based tube current modulation (TCM) and global tube current reduction. Methods: Semi-anthropomorphic thorax phantoms of four different sizes (15, 30, 35, and 40 cm lateral width) were used for dose measurement and image quality assessment. Four scans were performed on each phantom using 100 or 120 kV with a clinical CT scanner: (1) reference scan; (2) scan with bismuth breast shield of an appropriate thickness; (3) scan with organ-based TCM; and (4)more » scan with a global reduction in tube current chosen to match the dose reduction from bismuth shielding. Dose to the breast was measured with an ion chamber on the surface of the phantom. Image quality was evaluated by measuring the mean and standard deviation of CT numbers within the lung and heart regions. Results: Compared to the reference scan, dose to the breast region was decreased by about 21% for the 15-cm phantom with a pediatric (2-ply) shield and by about 37% for the 30, 35, and 40-cm phantoms with adult (4-ply) shields. Organ-based TCM decreased the dose by 12% for the 15-cm phantom, and 34-39% for the 30, 35, and 40-cm phantoms. Global lowering of the tube current reduced breast dose by 23% for the 15-cm phantom and 39% for the 30, 35, and 40-cm phantoms. In phantoms of all four sizes, image noise was increased in both the lung and heart regions with bismuth shielding. No significant increase in noise was observed with organ-based TCM. Decreasing tube current globally led to similar noise increases as bismuth shielding. Streak and beam hardening artifacts, and a resulting artifactual increase in CT numbers, were observed for scans with bismuth shields, but not for organ-based TCM or global tube current reduction. Conclusions: Organ-based TCM produces dose reduction to the breast similar to that achieved with bismuth shielding for both pediatric and adult phantoms. However, organ-based TCM does not affect image noise or CT number accuracy, both of which are adversely affected by bismuth shielding. Alternatively, globally decreasing the tube current can produce the same dose reduction to the breast as bismuth shielding, with a similar noise increase, yet without the streak artifacts and CT number errors caused by the bismuth shields. Moreover, globally decreasing the tube current reduces the dose to all tissues scanned, not simply to the breast.« less

Disturbed oxidative metabolism in organic brain syndrome caused by bismuth in skin creams.

PubMed

Krüger, G; Thomas, D J; Weinhardt, F; Hoyer, S

1976-09-04

Two patients are described with an organic brain syndrome thought to be due to bismuth (Bi) absorbed from a skin cream. Both patients had intellectual impairment and memory loss punctuated by periods of confusion, tremulousness, clumsiness, difficulty in walking, and myoclonic jerks. A similar clinical picture has been reported from Australia and France in patients taking insoluble bismuth salts by mouth. Bi was found in cerebral venous blood in both patients and in the cerebrospinal fluid in one. It is suggested that bismuth can cross the blood/brain barrier and disturb oxidative cerebral metabolism, because increased lactate production was found with decreased consumption of oxygen and glucose and lowered cerebral blood-flow.

Realgar nanoparticles versus ATO arsenic compounds induce in vitro and in vivo activity against multiple myeloma.

PubMed

Cholujova, Danka; Bujnakova, Zdenka; Dutkova, Erika; Hideshima, Teru; Groen, Richard W; Mitsiades, Constantine S; Richardson, Paul G; Dorfman, David M; Balaz, Peter; Anderson, Kenneth C; Jakubikova, Jana

2017-12-01

Multiple myeloma (MM), a B cell malignancy characterized by clonal proliferation of plasma cells in the bone marrow, remains incurable despite the use of novel and conventional therapies. In this study, we demonstrated MM cell cytotoxicity triggered by realgar (REA; As 4 S 4 ) nanoparticles (NREA) versus Arsenic trioxide (ATO) against MM cell lines and patient cells. Both NREA and ATO showed in vivo anti-MM activity, resulting in significantly decreased tumour burden. The anti-MM activity of NREA and ATO is associated with apoptosis, evidenced by DNA fragmentation, depletion of mitochondrial membrane potential, cleavage of caspases and anti-apoptotic proteins. NREA induced G 2 /M cell cycle arrest and modulation of cyclin B1, p53 (TP53), p21 (CDKN1A), Puma (BBC3) and Wee-1 (WEE1). Moreover, NREA induced modulation of key regulatory molecules in MM pathogenesis including JNK activation, c-Myc (MYC), BRD4, and histones. Importantly, NREA, but not ATO, significantly depleted the proportion and clonogenicity of the MM stem-like side population, even in the context of the bone marrow stromal cells. Finally, our study showed that both NREA and ATO triggered synergistic anti-MM activity when combined with lenalidomide or melphalan. Taken together, the anti-MM activity of NREA was more potent compared to ATO, providing the preclinical framework for clinical trials to improve patient outcome in MM. © 2017 John Wiley & Sons Ltd.

Group III-nitride thin films grown using MBE and bismuth

DOEpatents

Kisielowski, Christian K.; Rubin, Michael

2002-01-01

The present invention comprises growing gallium nitride films in the presence of bismuth using MBE at temperatures of about 1000 K or less. The present invention further comprises the gallium nitride films fabricated using the inventive fabrication method. The inventive films may be doped with magnesium or other dopants. The gallium nitride films were grown on sapphire substrates using a hollow anode Constricted Glow Discharge nitrogen plasma source. When bismuth was used as a surfactant, two-dimensional gallium nitride crystal sizes ranging between 10 .mu.m and 20 .mu.m were observed. This is 20 to 40 times larger than crystal sizes observed when GaN films were grown under similar circumstances but without bismuth. It is thought that the observed increase in crystal size is due bismuth inducing an increased surface diffusion coefficient for gallium. The calculated value of 4.7.times.10.sup.-7 cm.sup.2 /sec. reveals a virtual substrate temperature of 1258 K which is 260 degrees higher than the actual one.

Group III-nitride thin films grown using MBE and bismuth

DOEpatents

Kisielowski, Christian K.; Rubin, Michael

2000-01-01

The present invention comprises growing gallium nitride films in the presence of bismuth using MBE at temperatures of about 1000 K or less. The present invention further comprises the gallium nitride films fabricated using the inventive fabrication method. The inventive films may be doped with magnesium or other dopants. The gallium nitride films were grown on sapphire substrates using a hollow anode Constricted Glow Discharge nitrogen plasma source. When bismuth was used as a surfactant, two-dimensional gallium nitride crystal sizes ranging between 10 .mu.m and 20 .mu.m were observed. This is 20 to 40 times larger than crystal sizes observed when GaN films were grown under similar circumstances but without bismuth. It is thought that the observed increase in crystal size is due bismuth inducing an increased surface diffusion coefficient for gallium. The calculated value of 4.7.times.10.sup.-7 cm.sup.2 /sec. reveals a virtual substrate temperature of 1258 K which is 260 degrees higher than the actual one.

Contrasting role of antimony and bismuth dopants on the thermoelectric performance of lead selenide

DOE PAGES

Lee, Yeseul; Lo, Shih -Han; Chen, Changqiang; ...

2014-05-02

Increasing the conversion efficiency of thermoelectric materials is a key scientific driver behind a worldwide effort to enable heat to electricity power generation at competitive cost. Here we report an increased performance for antimony-doped lead selenide with a thermoelectric figure of merit of ~1.5 at 800 K. This is in sharp contrast to bismuth doped lead selenide, which reaches a figure of merit of <1. Substituting antimony or bismuth for lead achieves maximum power factors between ~23–27μW cm –1 K –2 at temperatures above 400 K. The addition of small amounts (~0.25 mol%) of antimony generates extensive nanoscale precipitates, whereasmore » comparable amounts of bismuth results in very few or no precipitates. The antimony-rich precipitates are endotaxial in lead selenide, and appear remarkably effective in reducing the lattice thermal conductivity. As a result, the corresponding bismuth-containing samples exhibit smaller reduction in lattice thermal conductivity.« less

Facile Solution Synthesis of Tungsten Trioxide Doped with Nanocrystalline Molybdenum Trioxide for Electrochromic Devices.

PubMed

Hasani, Amirhossein; Le, Quyet Van; Nguyen, Thang Phan; Choi, Kyoung Soon; Sohn, Woonbae; Kim, Jang-Kyo; Jang, Ho Won; Kim, Soo Young

2017-10-16

A facile, highly efficient approach to obtain molybdenum trioxide (MoO 3 )-doped tungsten trioxide (WO 3 ) is reported. An annealing process was used to transform ammonium tetrathiotungstate [(NH 4 ) 2 WS 4 ] to WO 3 in the presence of oxygen. Ammonium tetrathiomolybdate [(NH 4 ) 2 MoS 4 ] was used as a dopant to improve the film for use in an electrochromic (EC) cell. (NH 4 ) 2 MoS 4 at different concentrations (10, 20, 30, and 40 mM) was added to the (NH 4 ) 2 WS 4 precursor by sonication and the samples were annealed at 500 °C in air. Raman, X-ray diffraction, and X-ray photoelectron spectroscopy measurements confirmed that the (NH 4 ) 2 WS 4 precursor decomposed to WO 3 and the (NH 4 ) 2 MoS 4 -(NH 4 ) 2 WS 4 precursor was transformed to MoO 3 -doped WO 3 after annealing at 500 °C. It is shown that the MoO 3 -doped WO 3 film is more uniform and porous than pure WO 3 , confirming the doping quality and the privileges of the proposed method. The optimal MoO 3 -doped WO 3 used as an EC layer exhibited a high coloration efficiency of 128.1 cm 2 /C, which is larger than that of pure WO 3 (74.5 cm 2 /C). Therefore, MoO 3 -doped WO 3 synthesized by the reported method is a promising candidate for high-efficiency and low-cost smart windows.

Novel paint design based on nanopowder to protection against X and gamma rays

PubMed Central

Movahedi, Mohammad Mehdi; Abdi, Adibe; Mehdizadeh, Alireza; Dehghan, Naser; Heidari, Emad; Masumi, Yusef; Abbaszadeh, Mojtaba

2014-01-01

Background: Lead-based shields are the standard method of intraoperative radiation protection in the radiology and nuclear medicine department. Human lead toxicity is well documented. The lead used is heavy, lacks durability, is difficult to launder, and its disposal is associated with environmental hazards. The aim of this study was to design a lead free paint for protection against X and gamma rays. Materials and Methods: In this pilot st we evaluated several types of nano metal powder that seemed to have good absorption. The Monte Carlo code, MCNP4C, was used to model the attenuation of X-ray photons in paints with different designs. Experimental measurements were carried out to assess the attenuation properties of each paint design. Results: Among the different nano metal powder, nano tungsten trioxide and nano tin dioxide were the two most appropriate candidates for making paint in diagnostic photon energy range. Nano tungsten trioxide (15%) and nano tin dioxide (85%) provided the best protection in both simulation and experiments. After this step, attempts were made to produce appropriate nano tungsten trioxide-nano tin dioxide paints. The density of this nano tungsten trioxide-nano tin dioxide paint was 4.2 g/cm3. The MCNP simulation and experimental measurements for HVL (Half-Value Layer) values of this shield at 100 kVp were 0.25 and 0.23 mm, respectively. Conclusions: The results showed the cost-effective lead-free paint can be a great power in absorbing the X-rays and gamma rays and it can be used instead of lead. PMID:24591777

Microstructure and Mechanical Properties of Tin-Bismuth Solder Reinforced by Aluminum Borate Whiskers

NASA Astrophysics Data System (ADS)

Wang, Jun; Wei, Hongmei; He, Peng; Lin, Tiesong; Lu, Fengjiao

2015-10-01

Tin-bismuth solder has emerged as a promising lead-free alternative to tin-lead solder, especially for low-temperature packaging applications. However, the intrinsic brittleness of tin-bismuth solder alloy, aggravated by the coarse bismuth-rich phase and the thick interfacial intermetallic layer, notably limits the mechanical performance of the bonded joints. In this work, the microstructure and mechanical performance of solder joints were improved by adding 3.2 vol.% aluminum borate whiskers to the tin-bismuth solder alloy. This whisker-reinforced composite solder was fabricated through a simple process. Typically, 25- μm to 75- μm tin-bismuth particles were mixed with a small amount of aluminum borate whiskers with diameter of 0.5 μm to 1.5 μm and length of 5 μm to 15 μm. The addition of whiskers restrained the formation of coarse brittle bismuth-rich phase and decreased the lamellar spacing from 0.84 μm to 7.94 μm to the range of 0.22 μm to 1.80 μm. Moreover, the growth rate of the interfacial intermetallic layer during the remelting treatment decreased as well. The joint shear strength increased from 19.4 MPa to 24.7 MPa, and only declined by 4.9% (average, -5.9% to 15.8%) after the tenth remelting, while the shear strength of the joint without whiskers declined by 31.5% (average, 10.1-44.1%). The solder alloy was reinforced because of their high strength and high modulus and also the refinement effect on the solder alloy microstructure.

CONCENTRATION AND DECONTAMINATION OF SOLUTIONS CONTAINING PLUTONIUM VALUES BY BISMUTH PHOSPHATE CARRIER PRECIPITATION METHODS

DOEpatents

Seaborg, G.T.; Thompson, S.G.

1960-08-23

A process is given for isolating plutonium present in the tetravalent state in an aqueous solution together with fission products. First, the plutonium and fission products are coprecipitated on a bismuth phosphate carrier. The precipitate obtained is dissolved, and the plutonium in the solution is oxidized to the hexavalent state (with ceric nitrate, potassium dichromate, Pb/ sub 3/O/sub 4/, sodium bismuthate and/or potassium dichromate). Thereafter a carrier for fission products is added (bismuth phosphate, lanthanum fluoride, ceric phosphate, bismuth oxalate, thorium iodate, or thorium oxalate), and the fission-product precipitation can be repeated with one other of these carriers. After removal of the fission-product-containing precipitate or precipitates. the plutonium in the supernatant is reduced to the tetravalent state (with sulfur dioxide, hydrogen peroxide. or sodium nitrate), and a carrier for tetravalent plutonium is added (lanthanum fluoride, lanthanum hydroxide, lanthanum phosphate, ceric phosphate, thorium iodate, thorium oxalate, bismuth oxalate, or niobium pentoxide). The plutonium-containing precipitate is then dissolved in a relatively small volume of liquid so as to obtain a concentrated solution. Prior to dissolution, the bismuth phosphate precipitates first formed can be metathesized with a mixture of sodium hydroxide and potassium carbonate and plutonium-containing lanthanum fluorides with alkali-metal hydroxide. In the solutions formed from a plutonium-containing lanthanum fluoride carrier the plutonium can be selectively precipitated with a peroxide after the pH was adjusted preferably to a value of between 1 and 2. Various combinations of second, third, and fourth carriers are discussed.

Perforating internal root resorption repaired with mineral trioxide aggregate caused complete resolution of odontogenic sinus mucositis: a case report.

PubMed

Bendyk-Szeffer, Maja; Łagocka, Ryta; Trusewicz, Matylda; Lipski, Mariusz; Buczkowska-Radlińska, Jadwiga

2015-02-01

An extensive perforating internal root resorption accompanied by apical periodontitis and odontogenic sinus mucositis was detected on preoperative cone-beam computed tomographic scans in a first maxillary molar. After the chemomechanical debridement of the root canals, calcium hydroxide was placed as a temporary dressing for 7 days. Mineral trioxide aggregate was used to fill the perforation site with the aid of a surgical microscope. At the next visit, the root with the resorption defect was filled with warm vertical compaction of gutta-percha. A control cone-beam computed tomographic scan acquired 6 months after the endodontic treatment revealed complete resolution of the sinus retention cyst. Moreover, the patient's frequent otolaryngologic disturbances ceased. The tooth was functional with satisfactory clinical and radiographic results after 12 months. Based on the results of this case, successful repair of an extensive, perforating internal resorption with mineral trioxide aggregate may lead to complete resolution of apical periodontitis and maxillary sinus retention cyst. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Acute Esophageal Necrosis: A Case of Black Esophagus Associated with Bismuth Subsalicylate Ingestion

PubMed Central

Mankal, Pavan; Judeh, Hani; Kim, Sang

2014-01-01

We present a case of acute esophageal necrosis (AEN) likely caused by chronic use of bismuth subsalicylate, an active ingredient in over-the-counter Pepto-Bismol®, which contains 220 g of salicylic acid in each 30 mL quantity. While aspirin is known to cause gastritis and gastric ulcers, this is the first case, to our knowledge, reporting AEN after chronic bismuth subsalicylate use. PMID:26157851

URANIUM BISMUTHIDE DISPERSION IN MOLTEN METAL

DOEpatents

Teitel, R.J.

1959-10-27

The formation of intermetallic bismuth compounds of thorium or uranium dispersed in a liquid media containing bismuth and lead is described. A bismuthide of uranium dispersed in a liquid metal medium is formed by dissolving uranium in composition of lead and bismuth containing less than 80% lead and lowering the temperature of the composition to a temperature below the point at which the solubility of uranium is exceeded and above the melting point of the composition.

PURIFICATION OF PLUTONIUM USING A CERIUM PRECIPITATE AS A CARRIER FOR FISSION PRODUCTS

DOEpatents

Faris, B.F.; Olson, C.M.

1961-07-01

Bismuth phosphate carrier precipitation processes are described for the separation of plutonium from fission products wherein in at least one step bismuth phosphate is precipitated in the presence of hexavalent plutonium thereby carrying a portion of the fission products from soluble plu tonium values. In this step, a cerium phosphate precipitate is formed in conjunction with the bismuth phosphate precipitate, thereby increasing the amount of fission products removed from solution.

Bismuth interstitial impurities and the optical properties of GaP 1- x - yBi xN y

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christian, Theresa M.; Beaton, Daniel A.; Perkins, John D.

Two distinctive regimes of behavior are observed from GaP 1-x-y Bi x N y alloys with x < 2.4%, y < 3.4% grown by molecular beam epitaxy. These regimes are correlated with abundant bismuth interstitial impurities that are encouraged or suppressed according to the sample growth temperature, with up to 55% of incorporated bismuth located interstitially. When bismuth interstitials are present, radiative recombination arises at near-band-edge localized states rather than from impurity bands and deep state luminescence. Finally, this change demonstrates a novel strategy for controlling luminescence in isoelectronic semiconductor alloys and is attributed to a disruption of carrier transfermore » processes.« less

Preparation of bismuth titanate/calcium alginate composite bead and its photocatalytic degradation of dye pollutants

NASA Astrophysics Data System (ADS)

Gan, Huihui; Dong, Nanyang; Lu, Linxiao; Fu, Yan; Zhang, Huining; Qian, Yongxin; Zhang, Kefeng; Jin, Huixia

2017-08-01

In this study, the bismuth titanate/calcium alginate composite bead was synthesized by immobilizing bismuth titanate Bi4Ti3O12 particles into 1.5% sodium alginate (SA) matrix. The Bi4Ti3O12 particles were characterized by X-ray diffraction (XRD). The photocatalytic activity for the degradation of dye Rhodamine B in solution by as-prepared bismuth titanate/calcium alginate composite bead was investigated. The as-prepared composite beads CA/BTO-700 exhibited best photocatalytic efficiency for the degradation of RhB compared with CA/BTO-800 and CA/BTO-900 under simulated solar light. After 4 cycles in photocatalytic degradation of RhB, the degradation rate of the CA/BTO-700 nearly remained unchanged.

Bismuth interstitial impurities and the optical properties of GaP 1- x - yBi xN y

DOE PAGES

Christian, Theresa M.; Beaton, Daniel A.; Perkins, John D.; ...

2017-10-10

Two distinctive regimes of behavior are observed from GaP 1-x-y Bi x N y alloys with x < 2.4%, y < 3.4% grown by molecular beam epitaxy. These regimes are correlated with abundant bismuth interstitial impurities that are encouraged or suppressed according to the sample growth temperature, with up to 55% of incorporated bismuth located interstitially. When bismuth interstitials are present, radiative recombination arises at near-band-edge localized states rather than from impurity bands and deep state luminescence. Finally, this change demonstrates a novel strategy for controlling luminescence in isoelectronic semiconductor alloys and is attributed to a disruption of carrier transfermore » processes.« less

Evaporation-assisted high-power impulse magnetron sputtering: The deposition of tungsten oxide as a case study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hemberg, Axel; Dauchot, Jean-Pierre; Snyders, Rony

2012-07-15

The deposition rate during the synthesis of tungsten trioxide thin films by reactive high-power impulse magnetron sputtering (HiPIMS) of a tungsten target increases, above the dc threshold, as a result of the appropriate combination of the target voltage, the pulse duration, and the amount of oxygen in the reactive atmosphere. This behavior is likely to be caused by the evaporation of the low melting point tungsten trioxide layer covering the metallic target in such working conditions. The HiPIMS process is therefore assisted by thermal evaporation of the target material.

Bismuth-based electrochemical stripping analysis

DOEpatents

Wang, Joseph

2004-01-27

Method and apparatus for trace metal detection and analysis using bismuth-coated electrodes and electrochemical stripping analysis. Both anodic stripping voltammetry and adsorptive stripping analysis may be employed.

Arsenite-loaded nanoparticles inhibit PARP-1 to overcome multidrug resistance in hepatocellular carcinoma cells

NASA Astrophysics Data System (ADS)

Liu, Hanyu; Zhang, Zongjun; Chi, Xiaoqin; Zhao, Zhenghuan; Huang, Dengtong; Jin, Jianbin; Gao, Jinhao

2016-08-01

Hepatocellular carcinoma (HCC) is one of the highest incidences in cancers; however, traditional chemotherapy often suffers from low efficiency caused by drug resistance. Herein, we report an arsenite-loaded dual-drug (doxorubicin and arsenic trioxide, i.e., DOX and ATO) nanomedicine system (FeAsOx@SiO2-DOX, Combo NP) with significant drug synergy and pH-triggered drug release for effective treatment of DOX resistant HCC cells (HuH-7/ADM). This nano-formulation Combo NP exhibits the synergistic effect of DNA damage by DOX along with DNA repair interference by ATO, which results in unprecedented killing efficiency on DOX resistant cancer cells. More importantly, we explored the possible mechanism is that the activity of PARP-1 is inhibited by ATO during the treatment of Combo NP, which finally induces apoptosis of HuH-7/ADM cells by poly (ADP-ribosyl) ation suppression and DNA lesions accumulation. This study provides a smart drug delivery strategy to develop a novel synergistic combination therapy for effectively overcome drug- resistant cancer cells.

Bismuth Nephrotoxicity: Report of a Case

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gryboski, Joyce D.; Gotoff, Samuel P.

1961-12-28

A case of renal poisoning by bismuth thioglycolate is reported which demonstrates the nephrotoxicity of bismuth compounds in the pediatric age group. For treatment of warts the patient received a relatively small amount of bismuth thioglycollate (1.3 mg/kg body wt), and although the symptomatology was mild, the degree of azotemia was severe. Evidence of both tubular and glomerular damage was present, the former reflected by fixed urinary specific gravity and minimal glycosuria in the presence of a normal blood sugar, and the latter by azotemia and mild proteinuria. Backward diffusion of creatinine through damaged tubular epithelium probably contributed to themore » observed elevated plasma creatinine value, and the presence of a high anion content of serum probably represented retained phosphate, sulfate, and organic acids. The observed maculopapular rash probably corresponded to the socalled erythema of the ninth day, described previously as a rare manifestation of bismuth toxicity. The therapy employed was that for acute renal failure, but chelating agents, which are potential nephrotoxins, were not employed because of the known rapid excretion of bismuth thioglycollate. Rehydration was carried out, and electrolyte and protein intake was limited until diuresis was well established and the blood urea nitrogen had begun to fall. To avoid hyperkalemia, potassium restriction was carried out. Normal renal function was restored within a month after the onset of renal injury. It is suggested that the degree of sensitivity to the metal was related to the age of the patient and to the structural maturity of the kidney, for all cases of bismuth nephropathy reported the past 15 yr have occurred in the pediatric age group, children less than 3 yr being the most severely affected.« less

Bismuth Passivation Technique for High-Resolution X-Ray Detectors

NASA Technical Reports Server (NTRS)

Chervenak, James; Hess, Larry

2013-01-01

The Athena-plus team requires X-ray sensors with energy resolution of better than one part in 3,000 at 6 keV X-rays. While bismuth is an excellent material for high X-ray stopping power and low heat capacity (for large signal when an X-ray is stopped by the absorber), oxidation of the bismuth surface can lead to electron traps and other effects that degrade the energy resolution. Bismuth oxide reduction and nitride passivation techniques analogous to those used in indium passivation are being applied in a new technique. The technique will enable improved energy resolution and resistance to aging in bismuth-absorber-coupled X-ray sensors. Elemental bismuth is lithographically integrated into X-ray detector circuits. It encounters several steps where the Bi oxidizes. The technology discussed here will remove oxide from the surface of the Bi and replace it with nitridized surface. Removal of the native oxide and passivating to prevent the growth of the oxide will improve detector performance and insulate the detector against future degradation from oxide growth. Placing the Bi coated sensor in a vacuum system, a reduction chemistry in a plasma (nitrogen/hydrogen (N2/H2) + argon) is used to remove the oxide and promote nitridization of the cleaned Bi surface. Once passivated, the Bi will perform as a better X-ray thermalizer since energy will not be trapped in the bismuth oxides on the surface. A simple additional step, which can be added at various stages of the current fabrication process, can then be applied to encapsulate the Bi film. After plasma passivation, the Bi can be capped with a non-diffusive layer of metal or dielectric. A non-superconducting layer is required such as tungsten or tungsten nitride (WNx).

Liquid Bismuth Feed System for Electric Propulsion

NASA Technical Reports Server (NTRS)

Markusic, T. E.; Polzin, K. A.; Stanojev, B. J.

2006-01-01

Operation of Hall thrusters with bismuth propellant has been shown to be a promising path toward high-power, high-performance, long-lifetime electric propulsion for spaceflight missions. For example, the VHITAL project aims td accurately, experimentally assess the performance characteristics of 10 kW-class bismuth-fed Hall thrusters - in order to validate earlier results and resuscitate a promising technology that has been relatively dormant for about two decades. A critical element of these tests will be the precise metering of propellant to the thruster, since performance cannot be accurately assessed without an accurate accounting of mass flow rate. Earlier work used a pre/post-test propellant weighing scheme that did not provide any real-time measurement of mass flow rate while the thruster was firing, and makes subsequent performance calculations difficult. The motivation of the present work was to develop a precision liquid bismuth Propellant Management System (PMS) that provides real-time propellant mass flow rate measurement and control, enabling accurate thruster performance measurements. Additionally, our approach emphasizes the development of new liquid metal flow control components and, hence, will establish a basis for the future development of components for application in spaceflight. The design of various critical components in a bismuth PMS are described - reservoir, electromagnetic pump, hotspot flow sensor, and automated control system. Particular emphasis is given to material selection and high-temperature sealing techniques. Open loop calibration test results are reported, which validate the systems capability to deliver bismuth at mass flow rates ranging from 10 to 100 mg/sec with an uncertainty of less than +/- 5%. Results of integrated vaporizer/liquid PMS tests demonstrate all of the necessary elements of a complete bismuth feed system for electric propulsion.

Separation of Californium from other Actinides

DOEpatents

Mailen, J C; Ferris, L M

1973-09-25

A method is provided for separating californium from a fused fluoride composition containing californium and at least one element selected from the group consisting of plutonium, americium, curium, uranium, thorium, and protactinium which comprises contacting said fluoride composition with a liquid bismuth phase containing sufficient lithium or thorium to effect transfer of said actinides to the bismuth phase and then contacting the liquid bismuth phase with molten LiCl to effect selective transfer of californium to the chloride phase.

PLUTONIUM CARRIER METATHESIS WITH ORGANIC REAGENT

DOEpatents

Thompson, S.G.

1958-07-01

A method is described for converting a plutonium containing bismuth phosphate carrier precipitate Into a compositton more readily soluble in acid. The method consists of dissolving the bismuth phosphate precipitate in an aqueous solution of alkali metal hydroxide, and adding one of a certaia group of organic compounds, e.g., polyhydric alcohols or a-hydrorycarboxylic acids. The mixture is then heated causiing formation of a bismuth hydroxide precipitate containing plutonium which may be readily dissolved in nitric acid for further processing.

OPTICAL FIBRES AND FIBREOPTIC SENSORS: Bismuth-ring-doped fibres

NASA Astrophysics Data System (ADS)

Zlenko, Aleksandr S.; Akhmetshin, Ural G.; Dvoirin, Vladislav V.; Bogatyrev, Vladimir A.; Firstov, Sergei V.

2009-11-01

A new process for bismuth doping of optical fibres is proposed in which the dopant is introduced into a thin layer surrounding the fibre core. This enables bismuth stabilisation in the silica glass, with no limitations on the core composition. In particular, the GeO2 content of the fibre core in this study is 16 mol %. Spectroscopic characterisation of such fibres and optical gain measurements suggest that the proposed approach has considerable potential for laser applications.

Piezoelectric and Electrostrictive Materials for Transducer Applications. Volume 1.

DTIC Science & Technology

1988-03-01

3 Composites for Hydrophone Applications ...................... 2 2.3.1 Lead Bismuth Titanate Ferrate Compositions ................. 2 2.3.2...external variables are considered. 2.3 0:3 Composites for Hydrophone Applications 2.3.1 Lead Bismuth Titanate Ferrate Compositions the-"Following up...34" Even for doped samples however, the best results were obtained at the 50% bismuth ferrate composition. 0.. W* . - ’ w-w~-,wn~ , 7WI W W PP7W-w7WnM

Ranitidine bismuth citrate and ranitidine do not affect gastric emptying of a radio-labelled liquid meal.

PubMed Central

Parikh, R; Sweetland, J; Forster, E R; Bedding, A W; Farr, S J; Smith, J T

1994-01-01

Ranitidine bismuth citrate, a new chemical entity which is a salt complex of ranitidine and bismuth citrate, is being developed for the treatment of relapse of benign gastric and duodenal ulcer and eradication of Helicobacter pylori. The aim of the present study was to establish whether ranitidine bismuth citrate (800 mg) or ranitidine hydrochloride (300 mg) have any effect on gastric emptying of a liquid meal using gamma scintigraphy. On three separate occasions, each of twelve subjects received a single oral tablet of 800 mg ranitidine bismuth citrate, 300 mg ranitidine hydrochloride or placebo in random order. Thirty minutes after dosing each subject was given 375 ml of 99mTc-DTPA (diethylene triaminepentaacetic acid) labelled Clinifeed-ISO. The primary endpoint was the time to 50% gastric emptying (t50%). The proportion of the meal remaining was summarised by weighted mean proportion of the meal remaining in the stomach over 0-60 min and 0-180 min, separately. No differences were observed for t50%, weighted mean 0-60 min, and weighted mean 0-180 min between any two treatments. In man, we have detected no significant effect of single oral doses of ranitidine bismuth citrate 800 mg or ranitidine hydrochloride 300 mg on the rate of gastric emptying of a liquid meal when compared with placebo. PMID:7888296

How reliable are environmental data on 'orphan' elements? The case of bismuth concentrations in surface waters.

PubMed

Filella, Montserrat

2010-01-01

Like all elements of the periodic table, bismuth is ubiquitously distributed throughout the environment as a result of natural processes and human activities. It is present as Bi(III) in environmental, biological and geochemical samples. Although bismuth and its compounds are considered to be non-toxic to humans, its increasing use as a replacement for lead has highlighted how little is known about its environmental and ecotoxicological behaviour. In this first critical review paper on the existing information on bismuth occurrence in natural waters, 125 papers on fresh and marine waters have been collated. Although the initial objective of this study was to establish the range of the typical concentrations of total dissolved bismuth in natural waters, this proved impossible to achieve due to the wide, and hitherto unexplained, dispersion of published data. Since analytical limitations might be one of the reasons underlying value dispersion, new analytical methods published since 2000--intended to be applied to natural waters--have also been reviewed. Disappointingly, the detection limits of the bulk of them are well above those required; they are thus of limited usefulness. Analysis of the existing information on bismuth in secondary references (i.e., books, review chapters) and on its chemical speciation in seawater revealed that the uncritical reproduction of old data is a widespread practice.

Bismuth-Silicon and Bismuth-Polyurethane Composite Shields for Breast Protection in Chest Computed Tomography Examinations

PubMed Central

Mehnati, Parinaz; Arash, Mehran; Akhlaghi, Parisa

2018-01-01

The article aims at constructing protective composite shields for breasts in chest computed tomography and investigating the effects of applying these new bismuth composites on dose and image quality. Polyurethane and silicon with 5% of bismuth were fabricated as a protective shield. At first, their efficiency in attenuating the X-ray beam was investigated by calculating the total attenuation coefficients at diagnostic energy range. Then, a physical chest phantom was scanned without and with these shields at tube voltage of 120 kVp, and image parameters together with dose values were studied. The results showed that these two shields have great effects on attenuating the X-ray beam, especially for lower energies (<40 kV), and in average, the attenuation coefficients of bismuth-polyurethane composite are higher in this energy range. The maximum relative differences between the average Hounsfield units (HUs) and noises of images without and with shield for both composites in 13 regions of interest were 4.5% and 15.7%, respectively. Moreover, primary investigation confirmed the ability of both shields (especially polyurethane-bismuth composite) in dose reduction. Comparing these two composites regarding the amount of dose reduction, the changes in HU and noise, and attenuation coefficients in diagnostic energy range, it seems that polyurethane composite is more useful for dose reduction, especially for higher tube voltages. PMID:29628636

Absorber Materials for Transition-Edge Sensor X-ray Microcalorimeters

NASA Technical Reports Server (NTRS)

Brown, Ari-David; Bandler, Simon; Brekosky, Regis; Chervenak, James; Figueroa-Feliciano, Enectali; Finkbeiner, Fred; Sadleir, Jack; Iyomoto, Naoko; Kelley, Richard; Kilbourne, Caroline;

Thermodynamics of Pb17Li-bismuth interactions

NASA Astrophysics Data System (ADS)

Hubberstey, Peter; Sample, Tony

1994-09-01

Thermodynamic calculations of the PbBiLi ternary system have been completed to rationalise the formation of solid Li 3Bi on reaction of liquid Pb17Li with bismuth. At 723 K, the bismuth activity in equilibrium with liquid Pi17Li and solid Li 3Bi is calculated to be 9.50 × 10 -4; this can be correlated to a solubility of 2.09 × 10 -1 mol% Bi(2520 wppm). The corresponding bismuth activity in equilibrium with liquid Pb17Li and solid LiBi is 5.04 × 10 -2 (an extrapolated value as LiBi decomposes peritectically at 688 K). The minimum lithium content of PbLi alloys required to react with unit activity bismuth to form Li 3Bi at 723 K is calculated to be ˜ 1.8 mol% Li. The dominance of Li 3Bi in the PbBiLi system is attributed to its extreme stability as evidenced by both its high melting point (1418 K) and free energy of formation [ ΔGf0(Li 3Bi, c 723 K) = 212.8 kJ mol -1].

Pairing from dynamically screened Coulomb repulsion in bismuth

NASA Astrophysics Data System (ADS)

Ruhman, Jonathan; Lee, Patrick A.

2017-12-01

Recently, Prakash et al. have discovered bulk superconductivity in single crystals of bismuth, which is a semimetal with extremely low carrier density. At such low density, we argue that conventional electron-phonon coupling is too weak to be responsible for the binding of electrons into Cooper pairs. We study a dynamically screened Coulomb interaction with effective attraction generated on the scale of the collective plasma modes. We model the electronic states in bismuth to include three Dirac pockets with high velocity and one hole pocket with a significantly smaller velocity. We find a weak-coupling instability, which is greatly enhanced by the presence of the hole pocket. Therefore we argue that bismuth is the first material to exhibit superconductivity driven by retardation effects of Coulomb repulsion alone. By using realistic parameters for bismuth we find that the acoustic plasma mode does not play the central role in pairing. We also discuss a matrix element effect, resulting from the Dirac nature of the conduction band, which may affect Tc in the s -wave channel without breaking time-reversal symmetry.

Bismuth- and lithium-loaded plastic scintillators for gamma and neutron detection

NASA Astrophysics Data System (ADS)

Cherepy, Nerine J.; Sanner, Robert D.; Beck, Patrick R.; Swanberg, Erik L.; Tillotson, Thomas M.; Payne, Stephen A.; Hurlbut, Charles R.

2015-04-01

Transparent plastic scintillators based on polyvinyltoluene (PVT) have been fabricated with high loading of bismuth carboxylates for gamma spectroscopy, and with lithium carboxylates for neutron detection. When activated with a combination of standard fluors, 2,5-diphenyloxazole (PPO) and tetraphenylbutadiene (TPB), gamma light yields with 15 wt% bismuth tripivalate of 5000 Ph/MeV are measured. A PVT plastic formulation including 30 wt% lithium pivalate and 30 wt% PPO offers both pulse shape discrimination, and a neutron capture peak at 400 keVee. In another configuration, a bismuth-loaded PVT plastic is coated with ZnS(6Li) paint, permitting simultaneous gamma and neutron detection via pulse shape discrimination with a figure-of-merit of 3.8, while offering gamma spectroscopy with energy resolution of R(662 keV)=15%.

Nrf2 activation ameliorates cytotoxic effects of arsenic trioxide in acute promyelocytic leukemia cells through increased glutathione levels and arsenic efflux from cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishimoto, Shoichi; Suzuki, Toshihiro; Koike, Shin

Carnosic acid (CA), a phenolic diterpene isolated from Rosmarinus officinalis, has been shown to activate nuclear transcription factor E2-related factor 2 (Nrf2), which plays a central role in cytoprotective responses to oxidative and electrophilic stress. Recently, the Nrf2-Kelch ECH associating protein 1 (Keap1) pathway has been associated with cancer drug resistance attributable to modulation of the expression and activation of antioxidant and detoxification enzymes. However, the exact mechanisms by which Nrf2 activation results in chemoresistance are insufficiently understood to date. This study investigated the mechanisms by which the cytotoxic effects of arsenic trioxide (ATO), an anticancer drug, were decreased inmore » acute promyelocytic leukemia cells treated with CA, a typical activator of Nrf2 used to stimulate the Nrf2/Keap1 system. Our findings suggest that arsenic is non-enzymatically incorporated into NB4 cells and forms complexes that are dependent on intracellular glutathione (GSH) concentrations. In addition, the arsenic complexes are recognized as substrates by multidrug resistance proteins and subsequently excreted from the cells. Therefore, Nrf2-associated activation of the GSH biosynthetic pathway, followed by increased levels of intracellular GSH, are key mechanisms underlying accelerated arsenic efflux and attenuation of the cytotoxic effects of ATO. - Highlights: • Nrf2 activation attenuates the effect of arsenic trioxide to acute promyelocytic leukemia cells. • The sensitivity of arsenic trioxide to NB4 cells was dependent on efflux rate of arsenic. • Activation of the GSH biosynthesis is essential in Nrf2-regulated responses for arsenic efflux.« less

Self-assembled flower-like antimony trioxide microstructures with high infrared reflectance performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ge, Shengsong, E-mail: geshengsong@126.com; Yang, Xiaokun; Shao, Qian

A simple hydrothermal process was adopted to self-assembly prepare high infrared reflective antimony trioxide with three-dimensional flower-like microstructures. The morphologies of antimony trioxide microstructures were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM) respectively. It is also found that experimental parameters, such as NaOH concentration, surfactant concentration and volume ratio of ethanol–water played crucial roles in controlling the morphologies of Sb{sub 2}O{sub 3} microstructures. A possible growth mechanism of flower-like Sb{sub 2}O{sub 3} microstructure was proposed based on the experimental data. UV–vis–NIR spectra verified that the near infraredmore » reflectivity of the obtained flower-like microstructures could averagely achieve as 92% with maximum reflectivity of 98%, obviously higher than that of other different morphologies of antimony trioxide microstructures. It is expected that the flower-like Sb{sub 2}O{sub 3} nanostructures have some applications in optical materials and heat insulation coatings. - Graphical abstract: Flower-like Sb{sub 2}O{sub 3} microstructures that composed of nanosheets with thickness of ca. 100 nm exhibit high reflectivity under UV–vis–NIR spectra. Highlights: ► Uniform flower-like microstructures were synthesized via simple hydrothermal reaction. ► The flower-like Sb{sub 2}O{sub 3} microstructures exhibited higher reflectivity than other morphologies under the UV–vis–NIR light. ► Influencing parameters on the Sb{sub 2}O{sub 3} morphologies have been discussed in detail. ► Possible mechanism leading to flower-like microstructures was proposed.« less

POLONIUM SEPARATION PROCESS

DOEpatents

Karraker, D.G.

1959-07-14

A liquid-liquid extraction process is presented for the recovery of polonium from lead and bismuth. According to the invention an acidic aqueous chloride phase containing the polonium, lead, and bismuth values is contacted with a tributyl phosphate ether phase. The polonium preferentially enters the organic phase which is then separated and washed with an aqueous hydrochloric solution to remove any lead or bismuth which may also have been extracted. The now highly purified polonium in the organic phase may be transferred to an aqueous solution by extraction with aqueous nitric acid.

METHOD FOR REMOVING CONTAMINATION FROM PRECIPITATES

DOEpatents

Stahl, G.W.

1959-01-01

An improvement in the bismuth phosphate carrier precipitation process is presented for the recovery and purification of plutonium. When plutonium, in the tetravalent state, is carried on a bismuth phosphate precipitate, amounts of centain of the fission products are carried along with the plutonium. The improvement consists in washing such fission product contaminated preeipitates with an aqueous solution of ammonium hydrogen fluoride. since this solution has been found to be uniquely effective in washing fission production contamination from the bismuth phosphate precipitate.

Modified Electrodes Used for Electrochemical Detection of Metal Ions in Environmental Analysis

PubMed Central

March, Gregory; Nguyen, Tuan Dung; Piro, Benoit

2015-01-01

Heavy metal pollution is one of the most serious environmental problems, and regulations are becoming stricter. Many efforts have been made to develop sensors for monitoring heavy metals in the environment. This review aims at presenting the different label-free strategies used to develop electrochemical sensors for the detection of heavy metals such as lead, cadmium, mercury, arsenic etc. The first part of this review will be dedicated to stripping voltammetry techniques, on unmodified electrodes (mercury, bismuth or noble metals in the bulk form), or electrodes modified at their surface by nanoparticles, nanostructures (CNT, graphene) or other innovative materials such as boron-doped diamond. The second part will be dedicated to chemically modified electrodes especially those with conducting polymers. The last part of this review will focus on bio-modified electrodes. Special attention will be paid to strategies using biomolecules (DNA, peptide or proteins), enzymes or whole cells. PMID:25938789

Uniform nanoparticles by flame-assisted spray pyrolysis (FASP) of low cost precursors

PubMed Central

Rudin, Thomas; Wegner, Karsten

2013-01-01

A new flame-assisted spray pyrolysis (FASP) reactor design is presented, which allows the use of inexpensive precursors and solvents (e.g., ethanol) for synthesis of nanoparticles (10–20 nm) with uniform characteristics. In this reactor design, a gas-assisted atomizer generates the precursor solution spray that is mixed and combusted with externally fed inexpensive fuel gases (acetylene or methane) at a defined height above the atomizing nozzle. The gaseous fuel feed can be varied to control the combustion enthalpy content of the flame and onset of particle formation. This way, the enthalpy density of the flame is decoupled from the precursor solution composition. Low enthalpy content precursor solutions are prone to synthesis of non-uniform particles (e.g., bimodal particle size distribution) by standard flame spray pyrolysis (FSP) processes. For example, metal nitrates in ethanol typically produce nanosized particles by gas-to-particle conversion along with larger particles by droplet-to-particle conversion. The present FASP design facilitates the use of such low enthalpy precursor solutions for synthesis of homogeneous nanopowders by increasing the combustion enthalpy density of the flame with low-cost, gaseous fuels. The effect of flame enthalpy density on product properties in the FASP configuration is explored by the example of Bi2O3 nanoparticles produced from bismuth nitrate in ethanol. Product powders were characterized by nitrogen adsorption, X-ray diffraction, X-ray disk centrifuge, and transmission electron microscopy. Homogeneous Bi2O3 nanopowders were produced both by increasing the gaseous fuel content and, most notably, by cutting the air entrainment prior to ignition of the spray. PMID:23408113

University of Maryland MRSEC - News: Featured

Science.gov Websites

state at surface of bismuth selenide Completed device MRSEC research, published in NanoLetters ASAP in and M. S. Fuhrer, "Insulating behavior in ultrathin bismuth selenide field effect transistors

Effects of freshwater exposure to arsenic trioxide on the parr-smolt transformation of coho salmon (Oncorhynchus kisutch)

USGS Publications Warehouse

Nichols, J.W.; Wedemeyer, G.A.; Mayer, F.L.; Dickhoff, Walton W.; Gregory, S.V.; Yasutake, W.T.; Smith, S.D.

1984-01-01

The effects of chronic (6 months) exposure to arsenic trioxide in fresh water on the Parr-smolt transformation of coho salmon (Oncorhynchus kisutch) were evaluated. Exposure to 300 μg As/L (as As2O3) appeared to delay the onset of the normal increase in plasma thyroxine concentration and cause a transient reduction of gill Na+,K+-ATPase activity. Fish exposed to 300 μg As/L also migrated to the sea less successfully than did nonexposed smolts, but there were no effects on the survival and growth of smolts held in 28‰ salt water for 6 months.

Dissimilatory antimonate reduction and production of antimony trioxide microcrystals by a novel microorganism.

PubMed

Abin, Christopher A; Hollibaugh, James T

2014-01-01

Antimony (Sb) is a metalloid that has been exploited by humans since the beginning of modern civilization. The importance of Sb to such diverse industries as nanotechnology and health is underscored by the fact that it is currently the ninth-most mined metal worldwide. Although its toxicity mirrors that of its Group 15 neighbor arsenic, its environmental chemistry is very different, and, unlike arsenic, relatively little is known about the fate and transport of Sb, especially with regard to biologically mediated redox reactions. To further our understanding of the interactions between microorganisms and Sb, we have isolated a bacterium that is capable of using antimonate [Sb(V)] as a terminal electron acceptor for anaerobic respiration, resulting in the precipitation of antimonite [Sb(III)] as microcrystals of antimony trioxide. The bacterium, designated strain MLFW-2, is a sporulating member of a deeply branching lineage within the order Bacillales (phylum Firmicutes). This report provides the first unequivocal evidence that a bacterium is capable of conserving energy for growth and reproduction from the reduction of antimonate. Moreover, microbiological antimonate reduction may serve as a novel route for the production of antimony trioxide microcrystals of commercial significance to the nanotechnology industry.

Eradication of acute promyelocytic leukemia-initiating cells by PML/RARA-targeting.

PubMed

Nasr, Rihab; de Thé, Hugues

2010-06-01

Acute promyelocytic leukemia (APL) is characterized by a t(15;17) translocation that yields a PML/RARA fusion protein. Expression of PML/RARA, a potent transcriptional repressor, induces APL in mice. Both retinoic acid (RA) and arsenic trioxide directly target PML/RARA-mediated transcriptional repression and protein stability, inducing rapid differentiation of the promyelocytes and clinical remission in most APL patients. RA also triggers growth arrest and progressive clearance of leukemia initiating cells (LIC), both ex vivo and in vivo. Suboptimal RA concentrations or expression of the PLZF/RARA variant allows complete RA-induced differentiation, but neither LIC clearance nor disease remission. Thus, RA-induced differentiation and LIC clearance may be uncoupled. The RA/arsenic trioxide association, which dramatically synergizes for PML/RARA degradation but not for differentiation, rapidly clears LIC in a proteasome-dependent manner, resulting in APL eradication in murine models and patients. Collectively, these results demonstrate that LIC clearance, which mirrors PML/RARA degradation, is the primary basis for APL cure by the RA/arsenic trioxide association, rather than differentiation. Oncogene degradation could be a generally applicable therapeutic strategy to clear LICs in several types of tumors.

Tungsten Oxide Photonic Crystals as Optical Transducer for Gas Sensing.

PubMed

Amrehn, Sabrina; Wu, Xia; Wagner, Thorsten

2018-01-26

Some metal oxide semiconductors, such as tungsten trioxide or tin dioxide, are well-known as resistive transducers for gas sensing and offer high sensitivities down to the part per billion level. Electrical signal read-out, however, limits the information obtained on the electronic properties of metal oxides to a certain frequency range and its application because of the required electrical contacts. Therefore, a novel approach for building an optical transducer for gas reactions utilizing metal oxide photonic crystals is presented here. By the rational design of the structure and composition it is possible to synthesize a functional material which allows one to obtain insight into its electronic properties in the optical frequency range with simple experimental measures. The concept is demonstrated by tungsten trioxide inverse opal structure as optical transducer material for hydrogen sensing. The sensing behavior is analyzed in a temperature range from room temperature to 500 °C and in a wide hydrogen concentration range (3000 ppm to 10%). The sensing mechanism is mainly the refractive index change resulting from hydrogen intercalation in tungsten trioxide, but the back reaction has also impact on the optical properties of this system. Detailed chemical reaction studies provide suggestions for specific sensing conditions.

PROCESS USING BISMUTH PHOSPHATE AS A CARRIER PRECIPITATE FOR FISSION PRODUCTS AND PLUTONIUM VALUES

DOEpatents

Finzel, T.G.

1959-03-10

A process is described for separating plutonium from fission products carried therewith when plutonium in the reduced oxidation state is removed from a nitric acid solution of irradiated uranium by means of bismuth phosphate as a carrier precipitate. The bismuth phosphate carrier precipitate is dissolved by treatment with nitric acid and the plutonium therein is oxidized to the hexavalent oxidation state by means of potassium dichromate. Separation of the plutonium from the fission products is accomplished by again precipitating bismuth phosphate and removing the precipitate which now carries the fission products and a small percentage of the plutonium present. The amount of plutonium carried in this last step may be minimized by addition of sodium fluoride, so as to make the solution 0.03N in NaF, prior to the oxidation and prccipitation step.

Isotopic generator for bismuth-212 and lead-212 based on radium

DOEpatents

Hines, J.J.; Atcher, R.W.; Friedman, A.M.

1985-01-30

Disclosed are method and apparatus for providing radionuclides of bismuth-212 and lead-212. Thorium-228 and carrier solution starting material is input to a radiologically contained portion of an isotopic generator system, and radium-224 is separated from thorium-228 which is retained by a strongly basic anion exchange column. The separated radium-224 is transferred to an accessible, strongly acidic cationic exchange column. The cationic column retains the radium-224, and natural radioactive decay generates bismuth-212 and lead-212. The cationic exchange column can also be separated from the contained portion of the system and utilized without the extraordinary safety measures necessary in the contained portion. Furthermore, the cationic exchange column provides over a relatively long time period the short lived lead-212 and bismuth-212 radionuclides which are useful for a variety of medical therapies.

Bismuth- and lithium-loaded plastic scintillators for gamma and neutron detection

DOE PAGES

Cherepy, Nerine J.; Sanner, Robert D.; Beck, Patrick R.; ...

2015-01-09

In this paper, transparent plastic scintillators based on polyvinyltoluene (PVT) have been fabricated with high loading of bismuth carboxylates for gamma spectroscopy, and with lithium carboxylates for neutron detection. When activated with a combination of standard fluors, 2,5-diphenyloxazole (PPO) and tetraphenylbutadiene (TPB), gamma light yields with 15 wt% bismuth tripivalate of 5000 Ph/MeV are measured. A PVT plastic formulation including 30 wt% lithium pivalate and 30 wt% PPO offers both pulse shape discrimination, and a neutron capture peak at ~400 keVee. Finally, in another configuration, a bismuth-loaded PVT plastic is coated with ZnS( 6Li) paint, permitting simultaneous gamma and neutronmore » detection via pulse shape discrimination with a figure-of-merit of 3.8, while offering gamma spectroscopy with energy resolution of R(662 keV)=15%.« less

Simultaneous quantitative analysis of arsenic, bismuth, selenium, and tellurium in soil samples using multi-channel hydride-generation atomic fluorescence spectrometry.

PubMed

Wang, Fang; Zhang, Gai

2011-03-01

The basic principles and the application of hydride-generation multi-channel atomic fluorescence spectrometry (HG-MC-AFS) in soil analysis are described. It is generally understood that only one or two elements can be simultaneously detected by commonly used one- or two-channel HG-AFS. In this work, a new sample-sensitive and effective method for the analysis of arsenic, bismuth, tellurium, and selenium in soil samples by simultaneous detection using HG-MC-AFS was developed. The method detection limits for arsenic, bismuth, tellurium, and selenium are 0.19 μg/g, 0.10 μg/g, 0.11 μg/g, and 0.08 μg/g, respectively. This method was successfully applied to the simultaneous determination of arsenic, bismuth, tellurium, and selenium in soil samples.

Isotopic generator for bismuth-212 and lead-212 from radium

DOEpatents

Atcher, Robert W.; Friedman, Arnold M.; Hines, John

1987-01-01

A method and apparatus for providing radionuclides of bismuth-212 and lead-212. Thorium-228 and carrier solution starting material is input to a radiologically contained portion of an isotopic generator system, and radium-224 is separated from thorium-228 which is retained by a strongly basic anion exchange column. The separated radium-224 is transferred to an accessible, strongly acidic cationic exchange column. The cationic column retains the radium-224, and natural radioactive decay generates bismuth-212 and lead-212. The cationic exchange column can also be separated from the contained portion of the system and utilized without the extraordinary safety measures necessary in the contained portion. Furthermore, the cationic exchange column provides over a relatively long time period the short lived lead-212 and bismuth-212 radionuclides which are useful for a variety of medical therapies.

Second-line bismuth-containing quadruple therapy for Helicobacter pylori eradication and impact of diabetes

PubMed Central

Kim, Sung Eun; Park, Moo In; Park, Seun Ja; Moon, Won; Kim, Jae Hyun; Jung, Kyoungwon; Kim, Hae Koo; Lee, Young Dal

2017-01-01

AIM To investigate Helicobacter pylori (H. pylori) eradication rates using second-line bismuth-containing quadruple therapy and to identify predictors of eradication failure. METHODS This study included 636 patients who failed first-line triple therapy and received 7 d of bismuth-containing quadruple therapy between January 2005 and December 2015. We retrospectively demonstrated H. pylori eradication rates with respect to the year of therapy as well as demographic and clinical factors. H. pylori eradication was confirmed by a 13C-urea breath test or a rapid urease test at least 4 wk after the completion of bismuth-based quadruple therapy: proton pump inhibitor, metronidazole, bismuth, and tetracycline. RESULTS The overall eradication rates by intention-to-treat analysis and per-protocol analysis were 73.9% (95%CI: 70.1%-77.4%) and 94.5% (95%CI: 92.4%-96.5%), respectively. Annual eradication rates from 2005 to 2015 were 100.0%, 92.9%, 100.0%, 100.0%, 100.0%, 97.4%, 100.0%, 93.8%, 84.4%, 98.9%, and 92.5%, respectively, by per-protocol analysis. A multivariate analysis showed that diabetes mellitus (OR = 3.99, 95%CI: 1.56-10.20, P = 0.004) was associated with H. pylori eradication therapy failure. CONCLUSION The second-line bismuth-containing quadruple therapy for H. pylori infection is still effective in Korea, and diabetes mellitus is suggested to be a risk factor for eradication failure. PMID:28246480

Study of the bismuth oxide concentration required to provide Portland cement with adequate radiopacity for endodontic use.

PubMed

Bueno, Carlos Eduardo da Silveira; Zeferino, Eduardo Gregatto; Manhães, Luiz Roberto Coutinho; Rocha, Daniel Guimarães Pedro; Cunha, Rodrigo Sanches; De Martin, Alexandre Sigrist

2009-01-01

The purpose of this study was to determine the ideal concentration of bismuth oxide in white Portland cement to provide it with sufficient radiopacity for use as an endodontic material (ADA specification #57). 2-mm thick standardized test specimens of white MTA and of white Portland cement, as controls, and of white Portland cement with the experimental addition of 5%, 10%, 15%, 20%, 25% or 30% of bismuth oxide were radiographed and compared with various thicknesses of pure aluminum, using optic density to determine the observed grayscale levels of radiopacity in a scale ranging from 0 to 255. The data was submitted to ANOVA (p<0.05) and the Ryan-Einot-Gabriel-Welch and Quiot test (REGWQ) for multiple comparison of the means. White Portland cement with 0%, 5%, 10%, 15%, 20%, 25% and 30% of bismuth oxide presented mean readings of 63.3, 95.7, 110.7, 142.7, 151.3, 161.0 and 180.0 respectively. MTA presented a mean reading of 157.3. The readings of MTA and white Portland cement with 15% bismuth oxide did not differ significantly from the reading observed for a thickness of 4 mm of aluminum (145.3), which is considered ideal for a test specimen by ADA specification #57 (2 mm above the thickness of the test specimen). White MTA and white Portland cement with 15% bismuth oxide presented the radiopacity required for an endodontic cement.

Comparison of analytical performances of inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry for trace analysis of bismuth and bismuth oxide

NASA Astrophysics Data System (ADS)

Medvedev, Nickolay S.; Shaverina, Anastasiya V.; Tsygankova, Alphiya R.; Saprykin, Anatoly I.

2018-04-01

The paper presents а comparison of analytical performances of inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) for trace analysis of high purity bismuth and bismuth oxide. Matrix effects in the ICP-MS and ICP-AES methods were studied as a function of Bi concentration, ICP power and nebulizer flow rate. For ICP-MS the strong dependence of the matrix effects versus the atomic mass of analytes was observed. For ICP-AES the minimal matrix effects were achieved for spectral lines of analytes with low excitation potentials. The optimum degree of sample dilution providing minimum values of the limits of detection (LODs) was chosen. Both methods let us to reach LODs from n·10-7 to n·10-4 wt% for more than 50 trace elements. For most elements the LODs of ICP-MS were lower in comparison to ICP-AES. Validation of accuracy of the developed techniques was performed by "added-found" experiments and by comparison of the results of ICP-MS and ICP-AES analysis of high-purity bismuth oxide.

Short-term static corrosion tests in lead-bismuth

NASA Astrophysics Data System (ADS)

Soler Crespo, L.; Martín Muñoz, F. J.; Gómez Briceño, D.

2001-07-01

Martensitic steels have been proposed to be used as structural materials and as spallation target window in hybrid systems devoted to the transmutation of radioactive waste of long life and high activity. However, their compatibility with lead-bismuth in the operating conditions of these systems depends on the existence of a protective layer such as an oxide film. The feasibility of forming and maintaining an oxide layer or maintaining a pre-oxidised one has been studied. Martensitic steel F82Hmod. (8% Cr) has been tested in lead-bismuth under static and isothermal conditions at 400°C and 600°C. In order to study the first stages of the interaction between the steel and the eutectic, short-term tests (100 and 665 h) have been carried out. Pre-oxidised and as-received samples have been tested in atmospheres with different oxidant potential. For low oxygen concentration in lead-bismuth due to unexpected oxygen consumption in the experimental device, dissolution of as-received F82Hmod. occurs and pre-oxidation does not prevent the material dissolution. For high oxygen concentration, the pre-oxidation layer seems to improve the feasibility of protecting stainless steels controlling the oxygen potential of lead-bismuth with a gas phase.

Content and distribution of arsenic, bismuth, lithium and selenium in mineral and synthetic fertilizers and their contribution to soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Senesi, N.; Polemio, M.; Lorusso, L.

1979-01-01

Concentrations of arsenic, bismuth, lithium and selenium were determined by atomic absorption spectrophotometry in 32 samples of commercial fertilizers from various manufacturers and distributors. Arsenic and lithium were detected in all investigated samples, bismuth in 50% of samples and selenium only in two samples. Arsenic content ranged from 2 to 321 ppM; lithium varied from 5 to 0.1 ppM; bismuth was always lower than 0.5 ppM; selenium was detectable at the levels of 10 and 13 ppM. Fertilizers made from rock phosphates contained trace element amounts generally higher than those derived from rock carbonates, synthetic nitrogen fertilizers and potassium sulphate.more » Additions of trace elements from fertilizers applied at common rates to cultivated soils are tabulated and discussed on the basis of the natural soil reserves and toxicity levels for plants. Whereas applications of bismuth resulted always very low to influence the usual soil content and plant uptakes and selenium was only rarely present in fertilizers, lithium and moreover arsenic additions by fertilizers could influence the trace element status in soil, overcoming occasionally the toxicity levels for more sensitive crops.« less

Bismuth knowledge during the Renaissance strengthened by its use in Italian lustres production

NASA Astrophysics Data System (ADS)

Padeletti, G.; Fermo, P.

The knowledge of bismuth during the XV and XVI centuries represents an open question since, according to some authors, this element was confused with lead, tin and silver. On the contrary, G. Agricola (1494-1555), the pioneer of mineralogical science in Europe, in his two works (De Natura Fossilium, Lib X, 1546 and Bermannus Sive De Re Metallica Dialogus, 1528) asserts that bismuth was considered as an element distinct from the other metals at that time. This question gave rise to some interest, and von Lippmann in 1930 wrote a treatise dealing with the history of bismuth between 1400 and 1800. In this work we present the results obtained on Italian and Hispano-Moresque shards studied by means of X-ray diffraction, atomic absorption spectrometry with electrothermal atomisation, inductively coupled plasma optical emission spectrometry and scanning electron microscopy. It seems that our work could provide a new and important contribution to this debate, because we found bismuth in lustre composition of Renaissance shards produced in central Italy. Furthermore, we found that it could also be considered as a discriminating element between Italian and Hispano-Moresque productions, useful to assess their origin.

Bismuth Based Hybrid Perovskites A3Bi2 I9 (A: Methylammonium or Cesium) for Solar Cell Application.

PubMed

Park, Byung-Wook; Philippe, Bertrand; Zhang, Xiaoliang; Rensmo, Håkan; Boschloo, Gerrit; Johansson, Erik M J

2015-11-18

Low-toxic bismuth-based perovskites are prepared for the possible replacement of lead perovskite in solar cells. The perovskites have a hexagonal crystalline phase and light absorption in the visible region. A power conversion efficiency of over 1% is obtained for a solar cell with Cs3 Bi2 I9 perovskite, and it is concluded that bismuth perovskites have very promising properties for further development in solar cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

SEPARATION OF POLONIUM, PROTACTINIUM OR MIXTURES THEREOF IN AQUEOUS SOLUTION FROM BISMUTH, LEAD, ZIRCONIUM AND/OR COLUMBIUM VALUES

DOEpatents

Van Winkle, Q.; Kraus, K.A.

1959-10-27

A process is presented for separating polonium, protactinium, or mixtures thereof in aqueous solution from bismuth, zirconium, lead, and niobium values contained in the solution. The method comprises providing hydrochloric acid in the solution in a concentration of at least 5N. contacting the aqueous solution with a substantially waterimmiscible organic solvent such as diisopropyl ketone, and separating the aqueous phase containing the bismuth, zirconium, lead, and niobium from the organic extract phase containing the polonium, protactinium, or mixture thereof.

Alkali metal for ultraviolet band-pass filter

NASA Technical Reports Server (NTRS)

Mardesich, Nick (Inventor); Fraschetti, George A. (Inventor); Mccann, Timothy A. (Inventor); Mayall, Sherwood D. (Inventor); Dunn, Donald E. (Inventor); Trauger, John T. (Inventor)

1993-01-01

An alkali metal filter having a layer of metallic bismuth deposited onto the alkali metal is provided. The metallic bismuth acts to stabilize the surface of the alkali metal to prevent substantial surface migration from occurring on the alkali metal, which may degrade optical characteristics of the filter. To this end, a layer of metallic bismuth is deposited by vapor deposition over the alkali metal to a depth of approximately 5 to 10 A. A complete alkali metal filter is described along with a method for fabricating the alkali metal filter.

Ten-day quadruple therapy comprising low-dose rabeprazole, bismuth, amoxicillin and tetracycline is an effective and safe first-line treatment for Helicobacter pylori infection in population with high antibiotic resistance: a prospective, multicenter, randomized, parallel-controlled clinical trial in China.

PubMed

Xie, Yong; Zhu, Zhenhua; Wang, Jiangbin; Zhang, Lingxia; Zhang, Zhenyu; Lu, Hong; Zeng, Zhirong; Chen, Shiyao; Liu, Dongsheng; Lv, Nonghua

2018-06-18

Objectives: To investigate the efficacy and safety of 10-day bismuth quadruple therapy with amoxicillin, tetracycline or clarithromycin and different doses of rabeprazole for first-line treatment of Helicobacter pylori infection. Methods: This multicenter, randomized, parallel-controlled clinical trial was conducted between March 2013 and August 2014. A total of 431 H. pylori -infected patients with duodenal ulcers were enrolled and randomized into four treatment groups (1:1:1:1) for 10 days: 1. LR-BAC Group, which received rabeprazole 10 mg b.i.d., bismuth, amoxicillin and clarithromycin; 2. LR-BAT Group, which received rabeprazole 10mg b.i.d., bismuth, amoxicillin and tetracycline; 3. HR-BAC Group, which received rabeprazole 20 mg b.i.d., and bismuth, amoxicillin and clarithromycin; and 4. HR-BAT Group, which received rabeprazole 20 mg b.i.d., bismuth, amoxicillin, tetracycline. Antimicrobial susceptibility was assessed by the E-test method. The primary outcome was H. pylori eradication at 4 weeks after the treatment. Results: The per-protocol (PP) eradication rates in the LR-BAC, LR-BAT, HR-BAC, and HR-BAT groups were 94.1%, 91.9%, 94.8% and 91.9%, respectively, while the intention-to-treat (ITT) eradication rates in those groups were 87.2%, 87.2%, 87.7% and 86%, respectively. There was no significant difference between four groups in PP analysis( P =0.799) and ITT analysis( P =0.985). The efficacies of four treatment therapy were not affected by antibiotics resistance. The adverse events in four treatment groups were similar, CNS and gastrointestinal symptoms were the most common reported. Conclusions: Bismuth-containing quadruple therapy with low-dose rabeprazole, amoxicillin and tetracycline is a good option for first-line treatment of H. pylori infection in population with high antibiotic resistance. Copyright © 2018 Xie et al.

Compact and Integrated Liquid Bismuth Propellant Feed System

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Stanojev, Boris; Korman, Valentin; Gross, Jeffrey T.

2007-01-01

Operation of Hall thrusters with bismuth propellant has been shown to be a promising path toward high-power, high-performance, long-lifetime electric propulsion for spaceflight missions [1]. There has been considerable effort in the past three years aimed at resuscitating this promising technology and validating earlier experimental results indicating the advantages of a bismuth-fed Hall thruster. A critical element of the present effort is the precise metering of propellant to the thruster, since performance cannot be accurately assessed without an accurate accounting of mass flow rate. Earlier work used a pre./post-test propellant weighing scheme that did not provide any real-time measurement of mass flow rate while the thruster was firing, and makes subsequent performance calculations difficult. The motivation of the present work is to develop a precision liquid bismuth Propellant Management System (PMS) that provides hot, molten bismuth to the thruster while simultaneously monitoring in real-time the propellant mass flow rate. The system is a derivative of our previous propellant feed system [2], but the present system represents a more compact design. In addition, all control electronics are integrated into a single unit and designed to reside on a thrust stand and operate in the relevant vacuum environment where the thruster is operating, significantly increasing the present technology readiness level of liquid metal propellant feed systems. The design of various critical components in a bismuth PMS are described. These include the bismuth reservoir and pressurization system, 'hotspot' flow sensor, power system and integrated control system. Particular emphasis is given to selection of the electronics employed in this system and the methods that were used to isolate the power and control systems from the high-temperature portions of the feed system and thruster. Open loop calibration test results from the 'hotspot' flow sensor are reported, and results of integrated thruster/PMS tests demonstrate operation of the feed system in the relevant environment.

Physical and optical property studies on Bi3+ ion containing vanadium sodium borate glasses

NASA Astrophysics Data System (ADS)

Venkatesh, G.; Meera, B. N.; Eraiah, B.

2018-04-01

xBi2O3-(15-x)V2O5-45B2O3-40Na2O glasses have been prepared using melt quenching technique. Amorphous nature of the glasses is verified using powder XRD. Densities and molar volume have been determined as a function of bismuth content and interestingly both increases as a function of bismuth content. Further oxygen packing density (OPD) is found to decrease with bismuth content. The increase in the molar volume as a function of bismuth content may be due to structural changes in the glass network. The optical properties performed from the optical absorption spectra were recorded in the wavelength range 200-1100 nm using UV-Visible spectrophotometer. The theoretical optical basicity of the oxides have also been estimated. The calculated energy band gap values increases with increase in Bi2O3 content.

Evaluation of the gamma radiation shielding parameters of bismuth modified quaternary glass system

NASA Astrophysics Data System (ADS)

Kaur, Parminder; Singh, K. J.; Thakur, Sonika

2018-05-01

Glasses modified with heavy metal oxides (HMO) are an interesting area of research in the field of gamma-ray shielding. Bismuth modified lithium-zinc-borate glasses have been studied whereby bismuth oxide is added from 0 to 50 mol%. The gamma ray shielding properties of the glasses were evaluated at photon energy 662 keV with the help of XMuDat computer program by using the Hubbell and Seltzer database. Various gamma ray shielding parameters such as attenuation coefficient, shield thickness in terms of half and tenth value layer, effective atomic number have been studied in this work. A useful comparison of this glass system has been made with standard radiation shielding concretes viz. ordinary, barite and iron concrete. The glass samples containing 20 to 50 mol% bismuth oxide have shown better gamma ray shielding properties and hence have the potential to become good radiation absorbers.

Two-band induced superconductivity in single-layer graphene and topological insulator bismuth selenide

NASA Astrophysics Data System (ADS)

Talantsev, E. F.; Crump, W. P.; Tallon, J. L.

2018-01-01

Proximity-induced superconductivity in single-layer graphene (SLG) and in topological insulators represent almost ideal examples of superconductivity in two dimensions. Fundamental mechanisms governing superconductivity in the 2D limit are of central interest for modern condensed-matter physics. To deduce fundamental parameters of superconductor/graphene/superconductor and superconductor/bismuth selenide/superconductor junctions we investigate the self-field critical currents in these devices using the formalism of the Ambegaokar-Baratoff model. Our central finding is that the induced superconducting state in SLG and bismuth selenide each exhibits gapping on two superconducting bands. Based on recent results obtained on ultra-thin films of natural superconductors, including single-atomic layer of iron selenide, double and triple atomic layers of gallium, and several atomic layer tantalum disulphide, we conclude that a two-band induced superconducting state in SLG and bismuth selenide is part of a wider, more general multiple-band phenomenology of currently unknown origin.

Identification of Nanocrystalline Inclusions in Bismuth-Doped Silica Fibers and Preforms.

PubMed

Iskhakova, Liudmila D; Milovich, Filipp O; Mashinsky, Valery M; Zlenko, Alexander S; Borisovsky, Sergey E; Dianov, Evgeny M

2016-10-01

The nature of nanocrystalline inclusions and dopant distribution in bismuth-doped silicate fibers and preforms are studied by scanning and transmission electron microscopy, and energy and wavelength-dispersive X-ray microanalysis. The core compositions are Bi:SiO2, Bi:Al2O3-SiO2, Bi:GeO2-SiO2, Bi:Al2O3-GeO2-SiO2, and Bi:P2O5-Al2O3-GeO2-SiO2. Nanocrystals of metallic Bi, Bi2O3, SiO2, GeO2, and Bi4(GeO4)3 are observed in these glasses. These inclusions can be the reason for the background optical loss in bismuth-doped optical fibers. The bismuth concentration of 0.0048±0.0006 at% is directly measured in aluminosilicate optical fibers with effective laser generation (slope efficiency of 27% at room temperature).

Stopping cross sections of He + ions in bismuth

NASA Astrophysics Data System (ADS)

Kuldeep; Jain, Animesh K.

1985-06-01

The stopping cross sections, ɛ( E), of He + ions in bismuth have been measured by Rutherford backscattering spectrometry (RBS) at incident energies ranging from E = 1.6-3.4 MeV. The energy loss of He + ions and thicknesses of the bismuth films deposited on aluminium substrates were determined from the RBS spectra at each energy for scattering angles of 130° and 165°. The film thicknesses of some of the samples were also measured by weighing and the results compared with those from RBS. Parameters for energy dependence of stopping cross section in the Varelas-Biersack interpolation formula have been obtained for bismuth from a fit to all the available experimental data. Accuracy of our method based on RBS is demonstrated by measurements on copper, for which ɛ( E) is already well studied. It is also shown that reliable ɛ( E) values may be obtained even on samples with non-uniform film thickness.

An on-line system using ion-imprinted polymer for preconcentration and determination of bismuth in seawater employing atomic fluorescence spectrometry.

PubMed

Felix, Caio S A; Silva, Darllen G; Andrade, Heloysa M C; Riatto, Valeria B; Victor, Mauricio M; Ferreira, Sergio L C

2018-07-01

This work proposes an on-line preconcentration system using ion-imprinted polymer (IIP) for determination of bismuth in seawater employing atomic fluorescence spectrometry (AFS). The polymer was synthesized using 2- (5-bromo-2-pyridylazo) -5-diethylaminophenol (Br-PADAP) for complex formation, ethylene glycol dimethacrylate (EGDMA), cross-linking reagent and methacrylic acid (AMA) reagents, used as the functional monomer, 2,2-azobisisobutyronitrile was used as the radical initiator. The polymer was characterized employing the Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The determination of bismuth was performed employing hydride generation atomic fluorescence spectrometry (HG AFS) and the experimental conditions were optimized using a Box Behnken design involving the factors sample pH, eluent concentration and sodium tetrahydroborate concentration. So, using the optimized conditions the system allows the determination of bismuth with limits of detection and quantification of 26 and 88 ng L -1 , a preconcentration factor of 19.8. All these parameters were determined using a sample volume of 25 mL. The precision expressed as relative standard deviation (RSD%) was 3.7% for a bismuth(III) solution of concentration 0.25 µg L -1 . The system proposed was applied for the determination of bismuth in four seawater samples collected in Salvador City, Bahia State, Brazil. The concentrations obtained varied from 0.38 to 0.45 μg L -1 . The accuracy was evaluated by addition/recovery test, and the recoveries found varied from 92% to 101%. Copyright © 2018 Elsevier B.V. All rights reserved.

Bismuth silicate glass containing heavy metal oxide as a promising radiation shielding material

NASA Astrophysics Data System (ADS)

Elalaily, Nagia A.; Abou-Hussien, Eman M.; Saad, Ebtisam A.

2016-12-01

Optical and FTIR spectroscopic measurements and electron paramagnetic resonance (EPR) properties have been utilized to investigate and characterize the given compositions of binary bismuth silicate glasses. In this work, it is aimed to study the possibility of using the prepared bismuth silicate glasses as a good shielding material for γ-rays in which adding bismuth oxide to silicate glasses causes distinguish increase in its density by an order of magnitude ranging from one to two more than mono divalent oxides. The good thermal stability and high density of the bismuth-based silicate glass encourage many studies to be undertaken to understand its radiation shielding efficiency. For this purpose a glass containing 20% bismuth oxide and 80% SiO2 was prepared using the melting-annealing technique. In addition the effects of adding some alkali heavy metal oxides to this glass, such as PbO, BaO or SrO, were also studied. EPR measurements show that the prepared glasses have good stability when exposed to γ-irradiation. The changes in the FTIR spectra due to the presence of metal oxides were referred to the different housing positions and physical properties of the respective divalent Sr2+, Ba2+ and Pb2+ ions. Calculations of optical band gap energies were presented for some selected glasses from the UV data to support the probability of using these glasses as a gamma radiation shielding material. The results showed stability of both optical and magnetic spectra of the studied glasses toward gamma irradiation, which validates their irradiation shielding behavior and suitability as the radiation shielding candidate materials.

High Photon-to-Current Conversion in Solar Cells Based on Light-Absorbing Silver Bismuth Iodide.

PubMed

Zhu, Huimin; Pan, Mingao; Johansson, Malin B; Johansson, Erik M J

2017-06-22

Here, a lead-free silver bismuth iodide (AgI/BiI 3 ) with a crystal structure with space group R3‾ m is investigated for use in solar cells. Devices based on the silver bismuth iodide deposited from solution on top of TiO 2 and the conducting polymer poly(3-hexylthiophene-2,5-diyl) (P3HT) as a hole-transport layer are prepared and the photovoltaic performance is very promising with a power conversion efficiency over 2 %, which is higher than the performance of previously reported bismuth-halide materials for solar cells. Photocurrent generation is observed between 350 and 700 nm, and the maximum external quantum efficiency is around 45 %. The results are compared to solar cells based on the previously reported material AgBi 2 I 7 , and we observe a clearly higher performance for the devices with the new silver and bismuth iodides composition and different crystal structure. The X-ray diffraction spectrum of the most efficient silver bismuth iodide material shows a hexagonal crystal structure with space group R3‾ m, and from the light absorption spectrum we obtain an indirect band gap energy of 1.62 eV and a direct band gap energy of 1.85 eV. This report shows the possibility for finding new structures of metal-halides efficient in solar cells and points out new directions for further exploration of lead-free metal-halide solar cells. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Role of intestinal microbiota in transformation of bismuth and other metals and metalloids into volatile methyl and hydride derivatives in humans and mice.

PubMed

Michalke, Klaus; Schmidt, Annette; Huber, Britta; Meyer, Jörg; Sulkowski, Margareta; Hirner, Alfred V; Boertz, Jens; Mosel, Frank; Dammann, Philip; Hilken, Gero; Hedrich, Hans J; Dorsch, Martina; Rettenmeier, Albert W; Hensel, Reinhard

2008-05-01

The present study shows that feces samples of 14 human volunteers and isolated gut segments of mice (small intestine, cecum, and large intestine) are able to transform metals and metalloids into volatile derivatives ex situ during anaerobic incubation at 37 degrees C and neutral pH. Human feces and the gut of mice exhibit highly productive mechanisms for the formation of the toxic volatile derivative trimethylbismuth [(CH(3))(3)Bi] at rather low concentrations of bismuth (0.2 to 1 mumol kg(-1) [dry weight]). An increase of bismuth up to 2 to 14 mmol kg(-1) (dry weight) upon a single (human volunteers) or continuous (mouse study) administration of colloidal bismuth subcitrate resulted in an average increase of the derivatization rate from approximately 4 pmol h(-1) kg(-1) (dry weight) to 2,100 pmol h(-1) kg(-1) (dry weight) in human feces samples and from approximately 5 pmol h(-1) kg(-1) (dry weight) to 120 pmol h(-1) kg(-1) (dry weight) in mouse gut samples, respectively. The upshift of the bismuth content also led to an increase of derivatives of other elements (such as arsenic, antimony, and lead in human feces or tellurium and lead in the murine large intestine). The assumption that the gut microbiota plays a dominant role for these transformation processes, as indicated by the production of volatile derivatives of various elements in feces samples, is supported by the observation that the gut segments of germfree mice are unable to transform administered bismuth to (CH(3))(3)Bi.

Inadvertent exaggerated anticoagulation following use of bismuth subsalicylate in an enterally fed patient receiving warfarin therapy.

PubMed

Bingham, Angela L; Brown, Rex O; Dickerson, Roland N

2013-12-01

We report a case of an inadvertent increase in the international normalized ratio (INR) after the addition of bismuth subsalicylate for the treatment of diarrhea in an enterally fed patient receiving warfarin therapy. A 56-year-old Caucasian female presented to the trauma intensive care unit (ICU) with multiple lower extremity fractures. Warfarin was initiated for deep vein thrombosis prophylaxis due to the patient's inability to ambulate. The target INR was 2-3. Continuous intragastric enteral feeding was withheld 1 hour before and 1 hour after intragastric administration of warfarin. Bismuth subsalicylate 30 mL every 4 hours was prescribed for diarrhea. Within 3 days after starting bismuth subsalicylate therapy, the patient's INR increased from 2.56 to 3.54 and minor bleeding was noted from the patient's tracheostomy site. No significant change in warfarin dosage, variability in vitamin K intake, or medications that potentially alter warfarin metabolism were present during the unexpected rise in INR. When the bismuth subsalicylate was discontinued, the patient's INR stabilized into the target range on the same warfarin dose given at the time of the supratherapeutic INR. Salicylate displaces warfarin from plasma protein binding sites and may result in a significant increase in INR secondary to redistribution of warfarin to the free active form. Evaluation of this case report using the Drug Interaction Probability Scale and Naranjo Adverse Drug Reaction Probability Scale yielded scores consistent with a probable adverse drug interaction. Bismuth subsalicylate exaggerates warfarin's anticoagulant response and its concurrent use during warfarin therapy should be avoided.

Spin Hall effect and Landau spectrum of Dirac electrons in bismuth

NASA Astrophysics Data System (ADS)

Fuseya, Yuki

2015-03-01

Bismuth has played an important role in solid-state physics. Many key phenomena were first discovered in bismuth, such as diamagnetism, Seebeck, Nernst, Shubnikov-de Haas, and de Haas-van Alphen effects. These phenomena result from particular electronic states of bismuth. The strong spin-orbit interaction (~ 1.5eV) causes strong spin-dependent interband couplings resulting in an anomalous spin magnetic moment. We investigate the spin Hall effect and the angular dependent Landau spectrum of bismuth paying special attention to the effect of the anomalous spin magnetic moment. It is shown that the spin Hall insulator is possible and there is a fundamental relationship between the spin Hall conductivity and orbital diamagnetism in the insulating state of the Dirac electrons. Based on this theoretical finding, the magnitude of spin Hall conductivity is estimated for bismuth by that of orbital susceptibility. The magnitude of spin Hall conductivity turns out to be as large as 104Ω-1 cm-1, which is about 100 times larger than that of Pt. It is also shown that the ratio of the Zeeman splitting to the cyclotron energy, which reflects the effect of crystalline spin-orbit interaction, for holes at the T-point can be larger than 1.0 (the maximum of previous theories) and exhibit strong angular dependence, which gives a possible solution to the long-standing mystery of holes at the T-point. In collaboration with Masao Ogata, Hidetoshi Fukuyama, Zengwei Zhu, Benoît Fauqué, Woun Kang, and Kamran Behnia. Supported by JSPS (KAKENHI 24244053, 25870231, and 13428660).

Activity of Nanobins Loaded with Cisplatin and Arsenic Trioxide in Primary and Metastatic Breast Cancer

NASA Astrophysics Data System (ADS)

Swindell, Elden Peter, III

Despite recent advances in breast cancer screening and detection, the disease is still a leading cause of death for women of all ages. Young, African-American women are disproportionally affected with a type of breast cancer, triple-negative breast cancer, which is particularly difficult to treat and has the worst prognosis of any breast cancer subtype. These tumors often spread to the lungs, liver, bones and brains of patients, which is ultimately fatal. This dissertation presents results from a series of in vivo and in vitro experiments that investigate the clinical utility of a novel nanoparticulate formulation of cisplatin and arsenic trioxide, NB(Pt,As) for treating primary and metastatic triple-negative breast cancer. These nanobins consist of a solid, crystalline metal nanoparticle surrounded by a lipid bilayer with 80-90 nm diameter. This drug payload is extremely stable, and so NB(Pt,As) is extremely well tolerated in mice. Furthermore, NB(Pt,As) is effective in two different mouse models of breast cancer, one of primary tumor growth an another of lung metastases. A discovery presented here, that thiol containing compounds are required for drug release, may explain these seemingly incongruous results. The large amount of intracellular thiol can trigger drug release, while the low concentration of free thiols in blood is insufficient to cause drug release. To improve the treatment of brain tumors with this unique drug, we added transferrin to the surface of the nanobin using copper-catalyzed "click" chemistry, which preserves protein activity. The addition of transferrin to the nanobins enables 10 fold greater uptake in the brains of mice treated with the transferrin-targeted nanobins Tf-NB(Pt,A) compared to NB(Pt,As). By penetrating the blood brain barrier, the Tf-NB(Pt,As) was able to reduce breast cancer metastases in the brains of mice, whereas NB(Pt,As) had no effect. Taken together, these results demonstrate the intricate balance of drug release properties and seemingly subtle changes in drug design can have a profound impact on anti-tumor efficacy.

The combination of a mineral trioxide aggregate and an adhesive restorative approach to treat a crown-root fracture coupled with lateral root perforation in a mandibular second molar: a case report.

PubMed

Wang, P; Wang, S; Ni, L

2009-01-01

The current paper describes a modified treatment procedure for a traumatized mandibular left second molar resulting in a crown-root fracture and root perforation with the fracture line below the gingival attachment and alveolar bone crest. After the mobile crown-root fragment was extracted, the root perforation was obturated with mineral trioxide aggregate (MTA), and the subgingival defect was directly repaired with polyacid-modified resin composites (Ionosite Baseline). A 24-month recall showed no evidence of periodontal inflammation and no adverse symptoms, and the treated tooth exhibited good healing and normal function.

Dielectric, magnetic, ferroelectric, and Mossbauer properties of bismuth substituted nanosized cobalt ferrites through glycine nitrate synthesis method

NASA Astrophysics Data System (ADS)

Routray, Krutika L.; Sanyal, Dirtha; Behera, Dhrubananda

2017-12-01

CoFe2-xBixO4 nanoferrites with x = 0, 0.05, 0.1, 0.5, and 1.0 have been synthesized by the glycine nitrate process. The present study investigates the effect of Bi3+ substitution on the microstructural, dielectric, ferroelectric, magnetic, and Mossbauer properties of CoFe2O4 nanoparticles. The X-ray diffraction technique was used to confirm the phase purity and estimate the crystallite size which revealed the formation of a secondary phase when Bi3+ concentration exceeds x = 0.5. Transmission electron microscopy indicated the formation of grains by aggregation of small crystallites with a reduction in grain size to 20 nm with an increase in Bi3+ content and also divulged the lattice parameter value to be 8.378 Å, confirming the crystalline nature of the synthesised sample. Dielectric properties performed in the frequency range of 100 Hz to 1 MHz determined that the dielectric behavior is attributed to the Maxwell-Wagner polarization and the activation energy of the specimens is calculated from the dielectric measurements. The hysteresis curve indicated the ferrimagnetic nature of the samples. The samples also exhibited a well saturated P-E loop with gradual lowering in remenant polarization, coercive field, and saturation polarization with an increase in bismuth concentration. Mössbauer spectroscopy analysis confirmed the changes in magnetic moment of ions, their coupling with neighbouring ions, and cation exchange interactions. Owing to the high physical, thermal, and chemical stabilities, these magnetic ceramics, CoFe2-xBixO4, possesses tremendous potential in major understanding of magnetism and in magnetic recording applications for high density information storage.

SEPARATION OF FISSION PRODUCTS FROM PLUTONIUM BY PRECIPITATION

DOEpatents

Seaborg, G.T.; Thompson, S.G.; Davidson, N.R.

1959-09-01

Fission product separation from hexavalent plutonium by bismuth phosphate precipitation of the fission products is described. The precipitation, according to this invention, is improved by coprecipitating ceric and zirconium phosphates (0.05 to 2.5 grams/liter) with the bismuth phosphate.

METHOD FOR RECOVERING PLUTONIUM VALUES FROM SOLUTION USING A BISMUTH HYDROXIDE CARRIER PRECIPITATE

DOEpatents

Faris, B.F.

1961-04-25

Carrier precipitation processes for separating plutonium values from aqueous solutions are described. In accordance with the invention a bismuth hydroxide precipitate is formed in the plutonium-containing solution, thereby carrying plutonium values from the solution.

Fabrication of Nanovoid-Imbedded Bismuth Telluride with Low Dimensional System

NASA Technical Reports Server (NTRS)

Chu, Sang-Hyon (Inventor); Choi, Sang H. (Inventor); Kim, Jae-Woo (Inventor); Park, Yeonjoon (Inventor); Elliott, James R. (Inventor); King, Glen C. (Inventor); Stoakley, Diane M. (Inventor)

2013-01-01

A new fabrication method for nanovoids-imbedded bismuth telluride (Bi--Te) material with low dimensional (quantum-dots, quantum-wires, or quantum-wells) structure was conceived during the development of advanced thermoelectric (TE) materials. Bismuth telluride is currently the best-known candidate material for solid-state TE cooling devices because it possesses the highest TE figure of merit at room temperature. The innovative process described here allows nanometer-scale voids to be incorporated in Bi--Te material. The final nanovoid structure such as void size, size distribution, void location, etc. can be also controlled under various process conditions.

Ion mobility and transport properties of bismuth fluoride-containing solid solutions with tysonite-type structure

NASA Astrophysics Data System (ADS)

Kavun, V. Ya.; Uvarov, N. F.; Slobodyuk, A. B.; Merkulov, E. B.; Polyantsev, M. M.

2018-07-01

The ion mobility and conductivity of solid solutions with tysonite-type structure obtained by doping bismuth trifluoride with lead (II) fluoride, and zirconium and bismuth oxides have been studied using 19F NMR, X-ray diffraction analysis, and impedance spectroscopy. The types of ionic motions in the fluoride sublattice of the synthesized solid solutions in the temperature range 150-450 K have been determined and the energy of their activation has been estimated. Due to high ionic conductivity, above 10-2 S/cm at 570 K, these solid solutions can be considered as superionic conductors.

Preparation of Ferroelectric Thin Films of Bismuth Layer Structured Compounds

NASA Astrophysics Data System (ADS)

Watanabe, Hitoshi; Mihara, Takashi; Yoshimori, Hiroyuki; Araujo, Carlos

1995-09-01

Ferroelectric thin films of bismuth layer structured compounds, SrBi2Ta2O9, SrBi2Nb2O9, SrBi4Ti4O15 and their solid solutions, were formed onto a sputtered platinum layer on a silicon substrate using spin-on technique and metal-organic decomposition (MOD) method. X-ray diffraction (XRD) analysis and some electrical measurements were performed on the prepared thin films. XRD results of SrBi2(Ta1- x, Nb x)2O9 films (0≤x≤1) showed that niobium ions substitute for tantalum ions in an arbitrary ratio without any change of the layer structure and lattice constants. Furthermore, XRD results of SrBi2 xTa2O9 films (0≤x≤1.5) indicated that the formation of the bismuth layer structure does not always require an accurate bismuth content. The layer structure was formed above 50% of the stoichiometric bismuth content in the general formula. SrBi2(Ta1- x, Nb x)2O9 films with various Ta/Nb ratios have large enough remanent polarization for nonvolatile memory application and have shown high fatigue resistance against 1011 cycles of full switching of the remanent polarization. Mixture films of the three compounds were also investigated.

Dismantling and chemical characterization of spent Peltier thermoelectric devices for antimony, bismuth and tellurium recovery.

PubMed

Balva, Maxime; Legeai, Sophie; Garoux, Laetitia; Leclerc, Nathalie; Meux, Eric

2017-04-01

Major uses of thermoelectricity concern refrigeration purposes, using Peltier devices, mainly composed of antimony, bismuth and tellurium. Antimony was identified as a critical raw material by EU and resources of bismuth and tellurium are not inexhaustible, so it is necessary to imagine the recycling of thermoelectric devices. That for, a complete characterization is needed, which is the aim of this work. Peltier devices were manually dismantled in three parts: the thermoelectric legs, the alumina plates on which remain the electrical contacts and the silicone paste used to connect the plates. The characterization was performed using five Peltier devices. It includes mass balances of the components, X-ray diffraction analysis of the thermoelectric legs and elemental analysis of each part of the device. It appears that alumina represents 45% of a Peltier device in weight. The electrical contacts are mainly composed of copper and tin, and the thermoelectric legs of bismuth, tellurium and antimony. Thermoelectric legs appear to be Se-doped Bi 2 Te 3 and (Bi 0,5 Sb 1,5 )Te 3 for n type and p type semiconductors, respectively. This work shows that Peltier devices can be considered as a copper ore and that thermoelectric legs contain high amounts of bismuth, tellurium and antimony compared to their traditional resources.

Exploring reaction pathways in the hydrothermal growth of phase-pure bismuth ferrites

NASA Astrophysics Data System (ADS)

Goldman, Abby R.; Fredricks, Jeremy L.; Estroff, Lara A.

2017-06-01

Phase-pure bismuth ferrites (BiFeO3 and Bi2Fe4O9) are grown using hydrothermal synthesis. In addition to varying the KOH, bismuth, and iron salt concentrations to tune which crystalline phases are formed, we identified that a 48 h, pre-furnace, room temperature reaction is critical for the formation of phase-pure BiFeO3. To understand the reaction pathways leading to the different bismuth ferrite phases, we investigate the changes in composition of the intermediate products as a function of reagent concentrations and room temperature reaction times. During the syntheses that included a room temperature reaction, Bi25FeO40 is formed in the intermediate products, and BiFeO3 is the majority phase of the final products. The BiFeO3 crystals grown using this method are clusters of faceted subunits. These results indicate that forming Bi25FeO40 is a productive route to the formation of BiFeO3. Bi2Fe4O9 is formed via an alternate reaction pathway that proceeded via an amorphous precursor. This improved understanding of how hydrothermal synthesis can be used to control the phase-purity and morphology of bismuth ferrites opens doors to explore the multiferroic properties of BiFeO3 with complex morphologies.

Bismuth-embedded SBA-15 mesoporous silica for radioactive iodine capture and stable storage

NASA Astrophysics Data System (ADS)

Yang, Jae Hwan; Cho, Yong-Jun; Shin, Jin Myeong; Yim, Man-Sung

2015-10-01

Efficient capture and stable storage of the long-lived iodine-129 (129I), released as off-gas from nuclear fuel reprocessing, have been of significant concern in the waste management field. In this study, bismuth-embedded SBA-15 mesoporous silica was firstly applied for iodine capture and storage. SBA-15 was functionalized with thiol (-SH) groups, followed by bismuth adsorption with Bi-S bonding, which was thermally treated to form Bi2S3 within SBA-15. The bismuth-embedded SBA-15s demonstrated high iodine loading capacities (up to 540 mg-I/g-sorbent), which benefitted from high surface area and porosity of SBA-15 as well as the formation of thermodynamically stable BiI3 compound. Iodine physisorption was effectively suppressed due to the large pores present in SBA-15, resulting in chemisorption as a main mechanism for iodine confinement. Furthermore, a chemically durable iodine-bearing material was made with a facile post-sorption process, during which the iodine-incorporated phase was changed from BiI3 to chemically durable Bi5O7I. Thus, our results showed that both efficient capture and stabilization of 129I would be possible with the bismuth-embedded SBA-15, in contrast to other sorbents mainly focused on iodine capture.

Direct binding of arsenic trioxide to AMPK and generation of inhibitory effects on acute myeloid leukemia precursors

PubMed Central

Beauchamp, Elspeth M.; Kosciuczuk, Ewa M.; Serrano, Ruth; Nanavati, Dhaval; Swindell, Elden P.; Viollet, Benoit; O'Halloran, Thomas V.; Altman, Jessica K.; Platanias, Leonidas C.

2014-01-01

Arsenic trioxide (As2O3) exhibits potent antineoplastic effects and is used extensively in clinical oncology for the treatment of a subset of patients with acute myeloid leukemia (AML). Although As2O3 is known to regulate activation of several signaling cascades, the key events, accounting for its anti-leukemic properties, remain to be defined. We provide evidence that arsenic can directly bind to cysteine 299 in AMPKα and inhibit its activity. This inhibition of AMPK by arsenic is required in part for its cytotoxic effects on primitive leukemic progenitors from patients with AML, while concomitant treatment with an AMPK activator antagonizes in vivo the arsenic-induced antileukemic effects in a xenograft AML mouse model. A consequence of AMPK inhibition is activation of the mTOR pathway as a negative regulatory feedback loop. However, when AMPK expression is lost, arsenic-dependent activation of the kinase RSK downstream of MAPK activity compensates the generation of regulatory feedback signals through phosphorylation of downstream mTOR targets. Thus, therapeutic regimens with arsenic trioxide will need to include inhibitors of both the mTOR and RSK pathways in combination to prevent engagement of negative feedback loops and maximize antineoplastic responses. PMID:25344585

Towards a Therapeutic Reduction of Imatinib Refractory Myeloproliferative Neoplasm-Initiating Cells

PubMed Central

Philips, Steven T.; Hildenbrand, Zacariah L.; Oravecz-Wilson, Katherine I.; Foley, S. Blake; Mgbemena, Victoria E.; Ross, Theodora S.

2014-01-01

Myeloproliferative neoplasms (MPNs) such as chronic myelogenous (CML) and chronic myelomonocytic leukemias (CMML) are frequently induced by tyrosine kinase oncogenes. Although these MPNs are sensitive to tyrosine kinase inhibitors such as imatinib, patients often relapse upon withdrawal of therapy. We used a model of MPN, which is induced by co-expression of the oncoproteins HIP1/PDGFβR (H/P) and AML1/ETO (A/E) from their endogenous loci, to examine the mechanisms of disease development and recurrence following imatinib withdrawal. Although the MPN displayed a full hematologic response to imatinib, 100% of the diseased mice relapsed upon drug withdrawal. MPN persistence was not due to imatinib resistance mutations in the H/P oncogene or massive gene expression changes. Within one week of imatinib treatment, more than 98% of gene expression changes induced by the oncogenes in isolated hematopoietic stem and progenitor cells (LSKs) normalized. Supplementation of imatinib with G-CSF or arsenic trioxide reduced MPN-initiating cell frequencies and the combination of imatinib with arsenic trioxide cured a large fraction of mice with MPNs. In contrast, no mice in the imatinib-treated control cohorts were cured. These data suggest that treatment with a combination of arsenic trioxide and imatinib can eliminate refractory MPN-initiating cells and reduce disease relapse. PMID:24240679

Capping a Pulpotomy with Calcium Aluminosilicate Cement: Comparison to Mineral Trioxide Aggregates

PubMed Central

Kramer, Phillip R.; Woodmansey, Karl F.; White, Robert; Primus, Carolyn M.; Opperman, Lynne A.

2014-01-01

Introduction Calcium aluminate cements have shown little affinity for bacterial growth, low toxicity, and immunogenicity when used as a restoration material, but calcium aluminate cements have not been tested in vivo in pulpotomy procedures. Methods To address this question, a calcium aluminate cement (Quick-Set) was tested along with 2 mineral trioxide aggregates, ProRoot MTA and MTA Plus. These cements were used as a capping agent after pulpotomy. Control rats had no pulpotomy, or the pulpotomy was not capped. Proinflammatory cytokines interleukin (IL)-1β and IL-1α were measured, and histology was performed at 30 and 60 days after capping. The nociceptive response was determined by measuring the lengthening of the rat's meal duration. Results and Conclusions: IL-1β and IL-1α concentrations were reduced in the capped teeth, but no differences were observed among the 3 cements. Dentinal bridging could be detected at both 30 and 60 days with each of the 3 cements, and the pulps were still vital 60 days after capping. Meal duration significantly shortened after placement of the 3 different cements, indicating a nociceptive response, but there were no differences among the materials. Calcium aluminate cements had similar properties to mineral trioxide aggregates and is a viable option for pulpotomy procedures. PMID:25146026

Toward a therapeutic reduction of imatinib refractory myeloproliferative neoplasm-initiating cells.

PubMed

Philips, S T; Hildenbrand, Z L; Oravecz-Wilson, K I; Foley, S B; Mgbemena, V E; Ross, T S

2014-11-13

Myeloproliferative neoplasms (MPNs) such as chronic myelogenous (CML) and chronic myelomonocytic leukemias (CMML) are frequently induced by tyrosine kinase oncogenes. Although these MPNs are sensitive to tyrosine kinase inhibitors such as imatinib, patients often relapse upon withdrawal of therapy. We used a model of MPN, which is induced by co-expression of the oncoproteins HIP1/PDGFβR (H/P) and AML1/ETO from their endogenous loci, to examine the mechanisms of disease development and recurrence following imatinib withdrawal. Although the MPN displayed a full hematologic response to imatinib, 100% of the diseased mice relapsed upon drug withdrawal. MPN persistence was not due to imatinib resistance mutations in the H/P oncogene or massive gene expression changes. Within 1 week of imatinib treatment, more than 98% of gene expression changes induced by the oncogenes in isolated hematopoietic stem and progenitor cells (lineage(-)Sca-1(+)c-Kit(+) immunophenotype) normalized. Supplementation of imatinib with granulocyte colony-stimulating factor or arsenic trioxide reduced MPN-initiating cell frequencies and the combination of imatinib with arsenic trioxide cured a large fraction of mice with MPNs. In contrast, no mice in the imatinib-treated control cohorts were cured. These data suggest that treatment with a combination of arsenic trioxide and imatinib can eliminate refractory MPN-initiating cells and reduce disease relapse.

Enhanced Electrochemical Performances of Bi2O3/rGO Nanocomposite via Chemical Bonding as Anode Materials for Lithium Ion Batteries.

PubMed

Deng, Zhuo; Liu, Tingting; Chen, Tao; Jiang, Jiaxiang; Yang, Wanli; Guo, Jun; Zhao, Jianqing; Wang, Haibo; Gao, Lijun

2017-04-12

Bismuth oxide/reduced graphene oxide (termed Bi 2 O 3 @rGO) nanocomposite has been facilely prepared by a solvothermal method via introducing chemical bonding that has been demonstrated by Raman and X-ray photoelectron spectroscopy spectra. Tremendous single-crystal Bi 2 O 3 nanoparticles with an average size of ∼5 nm are anchored and uniformly dispersed on rGO sheets. Such a nanostructure results in enhanced electrochemical reversibility and cycling stability of Bi 2 O 3 @rGO composite materials as anodes for lithium ion batteries in comparison with agglomerated bare Bi 2 O 3 nanoparticles. The Bi 2 O 3 @rGO anode material can deliver a high initial capacity of ∼900 mAh/g at 0.1C and shows excellent rate capability of ∼270 mAh/g at 10C rates (1C = 600 mA/g). After 100 electrochemical cycles at 1C, the Bi 2 O 3 @rGO anode material retains a capacity of 347.3 mAh/g with corresponding capacity retention of 79%, which is significantly better than that of bare Bi 2 O 3 material. The lithium ion diffusion coefficient during lithiation-delithiation of Bi 2 O 3 @rGO nanocomposite has been evaluated to be around ∼10 -15 -10 -16 cm 2 /S. This work demonstrates the effects of chemical bonding between Bi 2 O 3 nanoparticles and rGO substrate on enhanced electrochemical performances of Bi 2 O 3 @rGO nanocomposite, which can be used as a promising anode alterative for superior lithium ion batteries.

Hydrothermal synthesis of barium strontium titanate and bismuth titanate materials

NASA Astrophysics Data System (ADS)

Xu, Huiwen

Hydrothermal processing facilitates the synthesis of crystalline ceramic materials of varying composition or complex crystal structure. The present work can be divided into two parts. First is to study the low temperature hydrothermal synthesis of bismuth titanate. Second is to study both thermodynamic and kinetic aspects of the hydrothermally synthesized barium strontium titanate. A chelating agent was used to form a Bi-Ti gel precursor. By hydrothermally treating the Bi-Ti gel, crystalline bismuth titanate has been synthesized at 160°C for the first time. Microstructural evolution during the low temperature synthesis of bismuth titanate can be divided into two stages, including condensation of Bi-Ti gel particles and crystallization of bismuth titanate. Crystallization of bismuth titanate occurred by an in situ transformation mechanism at an early stage followed by a dissolution-reprecipitation mechanism. Phase separation was observed in hydrothermally synthesized barium strontium titanate (BST). By hydrothermally treating BST powders between 250°C--300°C, an asymmetrical miscibility gap was found in the BaTiO3-SrTiO 3 system at low temperatures (T ≤ 320°C). A subregular solid solution model was applied to calculate the equilibrium compositions and the Gibbs free energy of formation of BST solid solution at low temperatures (T ≤ 320°C). The Gibbs free energy of formation of Sr-rich BST phase is larger than that of Ba-rich BST phase. Kinetic studies of single phase BST solid solution at 80°C show that, compared to the BaTiO3 or Ba-rich BST, SrTiO3 and Sr-rich BST powders form at lower reaction rates.

A multicenter, randomized, prospective study of 14-day ranitidine bismuth citrate- vs. lansoprazole-based triple therapy for the eradication of Helicobacter pylori in dyspeptic patients.

PubMed

Avşar, Erol; Tiftikçi, Arzu; Poturoğlu, Sule; Erzin, Yusuf; Kocakaya, Ozan; Dinçer, Dinç; Yıldırım, Bulut; Güliter, Sefa; Türkay, Cansel; Yılmaz, Uğur; Onuk, Mehmet Derya; Bölükbaş, Cengiz; Ellidokuz, Ender; Bektaş, Ahmet; Taşan, Güralp; Aytuğ, Necip; Ateş, Yüksel; Kaymakoğlu, Sabahattin

2013-01-01

Proton-pump inhibitor and ranitidine bismuth citrate-based triple regimens are the two recommended first line treatments for the eradication of Helicobacter pylori. We aimed to compare the effectiveness and tolerability of these two treatments in a prospective, multicentric, randomized study. Patients with dyspeptic complaints were recruited from 15 study centers. Presence of Helicobacter pylori was investigated by both histology and rapid urease test. The patients were randomized to either ranitidine bismuth citrate 400 mg bid plus amoxicillin 1 g bid plus clarithromycin 500 mg bid (n=149) or lansoprazole 30 mg bid plus amoxicillin 1 g bid plus clarithromycin 500 mg bid (n=130) treatment arm for 14 days. Adverse events have been recorded during the treatment phase. A 13 C urea breath test was performed 6 weeks after termination of treatment to assess the efficacy of the therapy. Eradication rate was calculated by intention-to-treat and per-protocol analysis. Two hundred seventy-nine patients (123 male, 156 female) were eligible for randomization. In per-protocol analysis (n=247), Helicobacter pylori was eradicated with ranitidine bismuth citrate- and lansoprazole-based regimens in 74,6% and 69,2% of cases, respectively (p>0,05). Intention-to-treat analysis (n=279) revealed that eradication rates were 65,1% and 63,6% in ranitidine bismuth citrate and in lansoprazole-based regimens, respectively (p>0,05). Both regimes were well-tolerated, and no serious adverse event was observed during the study. Ranitidine bismuth citrate-based regimen is at least as effective and tolerable as the classical proton-pump inhibitor-based regimen, but none of the therapies could achieve the recommendable eradication rate.

Probing the local structure of crystalline NaBiO3·XH2O and its acidified derivatives

NASA Astrophysics Data System (ADS)

Kozma, Karoly; Surta, T. Wesley; Molina, Pedro I.; Lyubinetsky, Igor; Stoxen, Wynn; Byrne, Nicole M.; Dolgos, Michelle; Nyman, May

2018-07-01

Sodium bismuthate is a commercially available, inexpensive, non-toxic and very potent inorganic oxidant and photocatalyst. It is one of the important reagents for oxidative separation of Am3+ from the chemically similar lanthanide ions, for its recovery or safe disposal from reprocessed nuclear fuel. While the structure of NaBiO3 has been described from powder and neutron diffraction; the structure of NaBiO3·XH2O, the manufactured form of sodium bismuthate, is currently unknown. Herein, we describe the structure of NaBiO3·XH2O (X = 3) using pair distribution function (PDF) analysis of X-ray total scattering data. In our proposed structure model, NaBiO3·3H2O is similar to NaBiO3, but with turbostratic disorder in the stacking direction of the alternating Bi-O and Na-O layers. We propose locations for the lattice water, and its role in creating turbostratic disorder. We also used PDF to describe the structural evolution of sodium bismuthate upon exposure to nitric acid, the conditions employed in for nuclear fuel reprocessing. We supported the proposed model for pristine NaBiO3·3H2O and its acidified derivatives by a variety of techniques including thermogravimetry, powder X-ray diffraction (PXRD), energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). By employing both surface and bulk techniques, we hypothesize that the bismuth reduced to Bi3+ upon aqueous acid exposure remains in the lattice, rather than completely dissolving and/or depositing on the surface, as prior suggested. Using pretreated acidified sodium bismuthate samples, we delineated the effects of acid strength vs. bismuthate structure/composition on Ce3+ to Ce4+ oxidation efficacy.

Photo-catalytic Activities of Plant Hormones on Semiconductor Nanoparticles by Laser-Activated Electron Tunneling and Emitting

PubMed Central

Tang, Xuemei; Huang, Lulu; Zhang, Wenyang; Jiang, Ruowei; Zhong, Hongying

2015-01-01

Understanding of the dynamic process of laser-induced ultrafast electron tunneling is still very limited. It has been thought that the photo-catalytic reaction of adsorbents on the surface is either dependent on the number of resultant electron-hole pairs where excess energy is lost to the lattice through coupling with phonon modes, or dependent on irradiation photon wavelength. We used UV (355 nm) laser pulses to excite electrons from the valence band to the conduction band of titanium dioxide (TiO2), zinc oxide (ZnO) and bismuth cobalt zinc oxide (Bi2O3)0.07(CoO)0.03(ZnO)0.9 semiconductor nanoparticles with different photo catalytic properties. Photoelectrons are extracted, accelerated in a static electric field and eventually captured by charge deficient atoms of adsorbed organic molecules. A time-of-flight mass spectrometer was used to detect negative molecules and fragment ions generated by un-paired electron directed bond cleavages. We show that the probability of electron tunneling is determined by the strength of the static electric field and intrinsic electron mobility of semiconductors. Photo-catalytic dissociation or polymerization reactions of adsorbents are highly dependent on the kinetic energy of tunneling electrons as well as the strength of laser influx. By using this approach, photo-activities of phytohormones have been investigated. PMID:25749635

Photo-catalytic Activities of Plant Hormones on Semiconductor Nanoparticles by Laser-Activated Electron Tunneling and Emitting

NASA Astrophysics Data System (ADS)

Tang, Xuemei; Huang, Lulu; Zhang, Wenyang; Jiang, Ruowei; Zhong, Hongying

2015-03-01

Understanding of the dynamic process of laser-induced ultrafast electron tunneling is still very limited. It has been thought that the photo-catalytic reaction of adsorbents on the surface is either dependent on the number of resultant electron-hole pairs where excess energy is lost to the lattice through coupling with phonon modes, or dependent on irradiation photon wavelength. We used UV (355 nm) laser pulses to excite electrons from the valence band to the conduction band of titanium dioxide (TiO2), zinc oxide (ZnO) and bismuth cobalt zinc oxide (Bi2O3)0.07(CoO)0.03(ZnO)0.9 semiconductor nanoparticles with different photo catalytic properties. Photoelectrons are extracted, accelerated in a static electric field and eventually captured by charge deficient atoms of adsorbed organic molecules. A time-of-flight mass spectrometer was used to detect negative molecules and fragment ions generated by un-paired electron directed bond cleavages. We show that the probability of electron tunneling is determined by the strength of the static electric field and intrinsic electron mobility of semiconductors. Photo-catalytic dissociation or polymerization reactions of adsorbents are highly dependent on the kinetic energy of tunneling electrons as well as the strength of laser influx. By using this approach, photo-activities of phytohormones have been investigated.

Ultrathin Bi2WO6 nanosheet decorated with Pt nanoparticles for efficient formaldehyde removal at room temperature

NASA Astrophysics Data System (ADS)

Sun, Dong; Le, Yao; Jiang, Chuanjia; Cheng, Bei

2018-05-01

Two-dimensional (2D) ultrathin bismuth tungstate (Bi2WO6) nanosheets (BWO-NS) with a thickness of approximately 4.0 nm were synthesized by a one-step hydrothermal method, and decorated with platinum (Pt) nanoparticles (NPs) via an impregnation/borohydride-reduction approach. The as-prepared ultrathin Pt-BWO-NS exhibited superior catalytic activity for removing gaseous formaldehyde (HCHO) at ambient temperature, in comparison with bulk counterpart with Bi2WO6 sheet thickness of tens of nanometers. The ultrathin structure endowed the Pt-BWO-NS sample with larger specific surface area, which can provide abundant surface active sites for HCHO adsorption and facilitate the homogeneous dispersion of Pt NPs. X-ray photoelectron spectroscopy and hydrogen temperature-programmed reduction analyses revealed the interaction between the Bi2WO6 support and Pt species, which is crucial for activating surface oxygen atoms to participate in the catalytic HCHO oxidation process. By conducting in situ diffuse reflectance infrared Fourier transform spectroscopy under different atmospheres, i.e., gaseous HCHO in nitrogen or oxygen (O2), the reaction mechanism and the role of O2 were elucidated, with dioxymethylene, formate and linearly adsorbed carbon monoxide identified as the main reaction intermediates. This study may provide new enlightenment on fabricating novel 2D nanomaterials for efficient indoor air purification and potentially other environmental applications.

Picture of the Week: Making the (reactive) case for explosives science

Science.gov Websites

: small organisms, big impacts Biocrusts: small organisms, big impacts View on Flickr Bismuth and tin on the rocks Bismuth and tin on the rocks View on Flickr Need to Know: Van Allen Belts Need to Know: Van

CONCENTRATION PROCESS FOR PLUTONIUM IONS, IN AN OXIDATION STATE NOT GREATER THAN +4, IN AQUEOUS ACID SOLUTION

DOEpatents

Seaborg, G.T.; Thompson, S.G.

1960-06-14

A process for concentrating plutonium is given in which plutonium is first precipitated with bismuth phosphate and then, after redissolution, precipitated with a different carrier such as lanthanum fluoride, uranium acetate, bismuth hydroxide, or niobic oxide.

ADSORPTION-BISMUTH PHOSPHATE METHOD FOR SEPARATING PLUTONIUM

DOEpatents

Russell, E.R.; Adamson, A.W.; Boyd, G.E.

1960-06-28

A process is given for separating plutonium from uranium and fission products. Plutonium and uranium are adsorbed by a cation exchange resin, plutonium is eluted from the adsorbent, and then, after oxidation to the hexavalent state, the plutonium is contacted with a bismuth phosphate carrier precipitate.

Preventing bacterial growth on implanted device with an interfacial metallic film and penetrating X-rays.

PubMed

An, Jincui; Sun, An; Qiao, Yong; Zhang, Peipei; Su, Ming

2015-02-01

Device-related infections have been a big problem for a long time. This paper describes a new method to inhibit bacterial growth on implanted device with tissue-penetrating X-ray radiation, where a thin metallic film deposited on the device is used as a radio-sensitizing film for bacterial inhibition. At a given dose of X-ray, the bacterial viability decreases as the thickness of metal film (bismuth) increases. The bacterial viability decreases with X-ray dose increases. At X-ray dose of 2.5 Gy, 98% of bacteria on 10 nm thick bismuth film are killed; while it is only 25% of bacteria are killed on the bare petri dish. The same dose of X-ray kills 8% fibroblast cells that are within a short distance from bismuth film (4 mm). These results suggest that penetrating X-rays can kill bacteria on bismuth thin film deposited on surface of implant device efficiently.

Seedless Growth of Bismuth Nanowire Array via Vacuum Thermal Evaporation

PubMed Central

Liu, Mingzhao; Nam, Chang-Yong; Zhang, Lihua

2015-01-01

Here a seedless and template-free technique is demonstrated to scalably grow bismuth nanowires, through thermal evaporation in high vacuum at RT. Conventionally reserved for the fabrication of metal thin films, thermal evaporation deposits bismuth into an array of vertical single crystalline nanowires over a flat thin film of vanadium held at RT, which is freshly deposited by magnetron sputtering or thermal evaporation. By controlling the temperature of the growth substrate the length and width of the nanowires can be tuned over a wide range. Responsible for this novel technique is a previously unknown nanowire growth mechanism that roots in the mild porosity of the vanadium thin film. Infiltrated into the vanadium pores, the bismuth domains (~ 1 nm) carry excessive surface energy that suppresses their melting point and continuously expels them out of the vanadium matrix to form nanowires. This discovery demonstrates the feasibility of scalable vapor phase synthesis of high purity nanomaterials without using any catalysts. PMID:26709727

Fabrication and modeling of bismuth titanate-PZT ceramic transducers for high temperature applications

NASA Astrophysics Data System (ADS)

Reinhardt, B.; Searfass, C.; Cyphers, R.; Sinding, K.; Pheil, C.; Tittmann, B.

2013-01-01

Utilization of a spray-on deposition technique of ferroelectric bismuth titanate (Bi4Ti3O12) composites has a competitive advantage to standard ultrasonic transducers. These can conform to curved surfaces, can operate at high temperature (Curie-Weiss temperature 685 °C) and are mechanically well-coupled to a substrate. However, an issue with many high temperature transducers such as bismuth titanate ceramics is that they have relatively low transduction efficiency, i.e. d33 is about 12-14 pC/F in Bi4Ti3O12 versus 650 pC/F in PZT-5H. It is a common conception that high-temperature capability comes at the cost of electro-mechanical coupling. It will be shown that the high temperature capability of bismuth-titanate-PZT composite transducers using the spray-on deposition technique previously developed, improves the electro-mechanical coupling while maintaining the high temperature performance and mechanical coupling. This material could provide advantages in harsh environments where high signal-to-noise ratios are needed.

Alkali-metal induced band structure deformation investigated by angle-resolved photoemission spectroscopy and first-principles calculations

NASA Astrophysics Data System (ADS)

Ito, S.; Feng, B.; Arita, M.; Someya, T.; Chen, W.-C.; Takayama, A.; Iimori, T.; Namatame, H.; Taniguchi, M.; Cheng, C.-M.; Tang, S.-J.; Komori, F.; Matsuda, I.

2018-04-01

Alkali-metal adsorption on the surface of materials is widely used for in situ surface electron doping, particularly for observing unoccupied band structures by angle-resolved photoemission spectroscopy (ARPES). However, the effects of alkali-metal atoms on the resulting band structures have yet to be fully investigated, owing to difficulties in both experiments and calculations. Here, we combine ARPES measurements on cesium-adsorbed ultrathin bismuth films with first-principles calculations of the electronic charge densities and demonstrate a simple method to evaluate alkali-metal induced band deformation. We reveal that deformation of bismuth surface bands is directly correlated with vertical charge-density profiles at each electronic state of bismuth. In contrast, a change in the quantized bulk bands is well described by a conventional rigid-band-shift picture. We discuss these two aspects of the band deformation holistically, considering spatial distributions of the electronic states and cesium-bismuth hybridization, and provide a prescription for applying alkali-metal adsorption to a wide range of materials.

System Analysis for Decay Heat Removal in Lead-Bismuth Cooled Natural Circulated Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takaaki Sakai; Yasuhiro Enuma; Takashi Iwasaki

2002-07-01

Decay heat removal analyses for lead-bismuth cooled natural circulation reactors are described in this paper. A combined multi-dimensional plant dynamics code (MSG-COPD) has been developed to conduct the system analysis for the natural circulation reactors. For the preliminary study, transient analysis has been performed for a 100 MWe lead-bismuth-cooled reactor designed by Argonne National Laboratory (ANL). In addition, decay heat removal characteristics of a 400 MWe lead-bismuth-cooled natural circulation reactor designed by Japan Nuclear Cycle Development Institute (JNC) has been evaluated by using MSG-COPD. PRACS (Primary Reactor Auxiliary Cooling System) is prepared for the JNC's concept to get sufficient heatmore » removal capacity. During 2000 sec after the transient, the outlet temperature shows increasing tendency up to the maximum temperature of 430 Centigrade, because the buoyancy force in a primary circulation path is temporary reduced. However, the natural circulation is recovered by the PRACS system and the out let temperature decreases successfully. (authors)« less

System Analysis for Decay Heat Removal in Lead-Bismuth-Cooled Natural-Circulation Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakai, Takaaki; Enuma, Yasuhiro; Iwasaki, Takashi

2004-03-15

Decay heat removal analyses for lead-bismuth-cooled natural-circulation reactors are described in this paper. A combined multidimensional plant dynamics code (MSG-COPD) has been developed to conduct the system analysis for the natural-circulation reactors. For the preliminary study, transient analysis has been performed for a 300-MW(thermal) lead-bismuth-cooled reactor designed by Argonne National Laboratory. In addition, decay heat removal characteristics of a 400-MW(electric) lead-bismuth-cooled natural-circulation reactor designed by the Japan Nuclear Cycle Development Institute (JNC) has been evaluated by using MSG-COPD. The primary reactor auxiliary cooling system (PRACS) is prepared for the JNC concept to get sufficient heat removal capacity. During 2000 smore » after the transient, the outlet temperature shows increasing tendency up to the maximum temperature of 430 deg. C because the buoyancy force in a primary circulation path is temporarily reduced. However, the natural circulation is recovered by the PRACS system, and the outlet temperature decreases successfully.« less

Quantum Effects in Inverse Opal Structures

NASA Astrophysics Data System (ADS)

Bleiweiss, Michael; Datta, Timir; Lungu, Anca; Yin, Ming; Iqbal, Zafar; Palm, Eric; Brandt, Bruce

2002-03-01

Properties of bismuth inverse opals and carbon opal replicas were studied. The bismuth nanostructures were fabricated by pressure infiltration into porous artificial opal, while the carbon opal replicas were created via CVD. These structures form a regular three-dimensional network in which the bismuth and carbon regions percolate in all directions between the close packed spheres of SiO_2. The sizes of the conducting regions are of the order of tens of nanometers. Static susceptibility of the bismuth inverse opal showed clear deHaas-vanAlphen oscillations. Transport measurements, including Hall, were done using standard ac four and six probe techniques in fields up to 17 T* and temperatures between 4.2 and 200 K. Observations of Shubnikov-deHaas oscillations in magnetoresistance, one-dimensional weak localization, quantum Hall and other effects will be discussed. *Performed at the National High Magnetic Field Lab (NHMFL) FSU, Tallahassee, FL. This work was partially supported by grants from DARPA-nanothermoelectrics, NASA-EPSCOR and the USC nanocenter.

Melt Convection Effects in the Bridgman Crystal Growth of an Alloy Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Simpson James E.; Garimella, Suresh V.; deGroh, Henry C., III; Abbaschian, Reza

1998-01-01

The solidification of a dilute bismuth-tin alloy under Bridgman crystal growth conditions is investigated in support of NASA's MEPHISTO space shuttle flight experiment. Computations are performed in two-dimensions with a uniform grid. The simulation includes the species-concentration, temperature and flow fields, as well as conduction in the ampoule. Fully transient simulations have been performed; no simplifying steady state approximations are used. Results are obtained under microgravity conditions for pure bismuth, and Bismuth-0.1 at.% Sn and Bi-1.0 at.% Sn alloys. The concentration dependence of the melting temperature is neglected; the solid/liquid interface temperature is assumed to be the melting temperature of pure bismuth for all cases studied. For the Bi-1.0 at.% Sn case the results indicate that a secondary convective cell, driven by solutal gradients, forms near the interface. The magnitude of the velocities in this cell increases with time; this causes increasing solute segregation at the liquid/solid interface.

Dynamic behavior of pump light radiation induced photo-bleaching effect on BAC-Si in bismuth/erbium co-doped optical fibers

NASA Astrophysics Data System (ADS)

Ding, Mingjie; Luo, Yanhua; Wen, Jianxiang; Peng, Gang-Ding

2018-02-01

Ultra-wide emission in bismuth doped optical fiber has been extremely studied for the development of the laser and amplifier working at near infrared band. In our homemade bismuth/erbium co-doped optical fiber, bismuth active center associated with silica (BAC-Si) has been found that when pumping at its resonant wavelength at 830 nm the NIR emission could be partially bleached. In addition, a self-recovery process has been observed at room temperature. However, the exact mechanism is still unclear. In this work, we have investigated the photo-bleaching effect on the BAC-Si via the pump power, pump wavelength and temperature dependence. Based on analyzing the result using stretched exponential function, it shows that the bleaching effect on BAC-Si has a strong link with the excitation process of Bi ion in BAC-Si. A potential energy curve model is used to illustrate the BAC-Si photo-bleaching process.

Volume and Surface Properties of a Bismuth-Containing Separating Nickel Melt

NASA Astrophysics Data System (ADS)

Filippov, K. S.

2017-11-01

The influence of a bismuth impurity on the properties of solid and liquid alloys in the concentration range that obeys Henry's law is considered. The structural and physicochemical properties, specifically, the density and the surface tension, of real melts are studied on relatively pure metals. The changes in the properties of the melts are estimated from changes in the temperature dependences of the density and the surface tension upon heating and cooling and in the concentration dependences of these parameters at a constant temperature. These dependences exhibit a correlation between the volume and surface properties of the melts: the density and the surface tension increase or decrease simultaneously. The introduction of bismuth in the nickel melt is accompanied by the appearance of a relatively strong compression effect (i.e., a decrease in the melt volume). At a certain bismuth content in the melt, the compression effect weakens because of the appearance of an excess phase or its associates and melt separation.

An ecotoxicological study on tin- and bismuth-catalysed PDMS based coatings containing a surface-active polymer.

PubMed

Pretti, Carlo; Oliva, Matteo; Mennillo, Elvira; Barbaglia, Martina; Funel, Marco; Reddy Yasani, Bhaskar; Martinelli, Elisa; Galli, Giancarlo

2013-12-01

Novel films were prepared by condensation curing reaction of a poly(dimethyl siloxane) (PDMS) matrix with bismuth neodecanoate and dibutyltin diacetate catalysts. An ecotoxicological study was performed on the leachates of the coatings using the bacterium Vibrio fischeri, the unicellular alga Dunaliella tertiolecta, the crustacean Artemia salina and the fish Sparus aurata (larvae) as testing organisms. A copper-based self-polishing commercial paint was also tested as reference. The results showed that the tin-catalysed coatings and the copper paint were highly toxic against at least two of the four test organisms, whereas bismuth-catalysed coatings did not show any toxic effect. Moreover, the same biological assessment was also carried out on PDMS coatings containing a surface-active fluorinated polymer. The toxicity of the entire polymeric system resulted only from the tin catalyst used for the condensation curing reaction, as the bismuth catalysed coatings incorporating the surface-active polymer remained atoxic toward all the tested organisms. © 2013 Elsevier Inc. All rights reserved.

Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

NASA Astrophysics Data System (ADS)

Goto, Masahiro; Sasaki, Michiko; Xu, Yibin; Zhan, Tianzhuo; Isoda, Yukihiro; Shinohara, Yoshikazu

2017-06-01

p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p-n modules of bismuth telluride without any doping process.

MO-F-CAMPUS-I-04: Patient Eye-Lens Dose Reduction in Routine Brain CT Examinations Using Organ-Based Tube Current Modulation and In-Plane Bismuth Shielding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, Hui-Yu; Liao, Ying-Lan; Chang Gung University / Chang Gung Memorial Hospital, Taoyun, Taiwan

Purpose: The purpose of this study is to assess eye-lens dose for patients who underwent brain CT examinations using two dose reduction Methods: organ-based tube current modulation (OBTCM) and in-plane bismuth shielding method. Methods: This study received institutional review board approval; written informed consent to participate was obtained from all patients. Ninety patients who underwent the routine brain CT examination were randomly assigned to three groups, ie. routine, OBTCM, and bismuth shield. The OBTCM technique reduced the tube current when the X-ray tube rotates in front of patients’ eye-lens region. The patients in the bismuth shield group were covered one-plymore » bismuth shield in the eyes’ region. Eye-lens doses were measured using TLD-100H chips and the total effective doses were calculated using CT-Expo according to the CT scanning parameters. The surface doses for patients at off-center positions were assessed to evaluate the off-centering effect. Results: Phantom measurements indicates that OBTCM technique could reduced by 26% to 28% of the surface dose to the eye lens, and increased by 25% of the surface dose at the opposed incident direction at the angle of 180°. Patients’ eye-lens doses were reduced 16.9% and 30.5% dose of bismuth shield scan and OBTCM scan, respectively compared to the routine scan. The eye-lens doses were apparently increased when the table position was lower than isocenter. Conclusion: Reducing the dose to the radiosensitive organs, such as eye lens, during routine brain CT examinations could lower the radiation risks. The OBTCM technique and in-plane bismuth shielding could be used to reduce the eye-lens dose. The eye-lens dose could be effectively reduced using OBTCM scan without interfering the diagnostic image quality. Patient position relative the CT gantry also affects the dose level of the eye lens. This study was supported by the grants from the Ministry of Science and Technology of Taiwan (MOST103-2314-B-182-009-MY2), and Chang Gung Memorial Hospital (CMRPD1C0682)« less

A bismuth activation counter for high sensitivity pulsed 14 MeV neutrons

NASA Astrophysics Data System (ADS)

Burns, E. J. T.; Thacher, P. D.; Hassig, G. J.; Decker, R. D.; Romero, J. A.; Barrett, K. P.

2011-08-01

We have built a fast neutron bismuth activation counter that measures activation counts from pulsed 14-MeV neutron generators for incident neutron fluences between 30 and 300 neutrons/cm2 at 15.2 cm (6 in.). The activation counter consists of a large bismuth germanate (BGO) detector surrounded by a bismuth metal shield in front of and concentric with the cylindrical detector housing. The 14 MeV neutrons activate the 2.6-millisecond (ms) isomer in the shield and the detector by the reaction 209Bi (n,2nγ) 208mBi. The use of millisecond isomers and activation counting times minimizes the background from other activated materials and the environment. In addition to activation, the bismuth metal shields against other outside radiation sources. We have tested the bismuth activation counter, simultaneously, with two data acquisition systems (DASs) and both give similar results. The two-dimensional (2D) DAS and three dimensional (3D) DAS both consist of pulse height analysis (PHA) systems that can be used to discriminate against gamma radiations below 300 keV photon energy, so that the detector can be used strictly as a counter. If the counting time is restricted to less than 25 ms after the neutron pulse, there are less than 10 counts of background for single pulse operation in all our operational environments tested so far. High-fluence neutron generator operations are restricted by large dead times and pulse height saturation. When we operate our 3D DAS PHA system in list mode acquisition (LIST), real-time corrections to dead time or live time can be made on the scale of 1 ms time windows or dwell times. The live time correction is consistent with nonparalyzable models for dead time of 1.0±0.2 μs for our 3D DAS and 1.5±0.3 μs for our 2D DAS dominated by our fixed time width analog to digital converters (ADCs). With the same solid angle, we have shown that the bismuth activation counter has a factor of 4 increase in sensitivity over our lead activation counter, because of higher counts and negligible backgrounds.

14 day sequential therapy versus 10 day bismuth quadruple therapy containing high-dose esomeprazole in the first-line and second-line treatment of Helicobacter pylori: a multicentre, non-inferiority, randomized trial.

PubMed

Liou, Jyh-Ming; Chen, Chieh-Chang; Fang, Yu-Jen; Chen, Po-Yueh; Chang, Chi-Yang; Chou, Chu-Kuang; Chen, Mei-Jyh; Tseng, Cheng-Hao; Lee, Ji-Yuh; Yang, Tsung-Hua; Chiu, Min-Chin; Yu, Jian-Jyun; Kuo, Chia-Chi; Luo, Jiing-Chyuan; Hsu, Wen-Feng; Hu, Wen-Hao; Tsai, Min-Horn; Lin, Jaw-Town; Shun, Chia-Tung; Twu, Gary; Lee, Yi-Chia; Bair, Ming-Jong; Wu, Ming-Shiang

2018-05-29

Whether extending the treatment length and the use of high-dose esomeprazole may optimize the efficacy of Helicobacter pylori eradication remains unknown. To compare the efficacy and tolerability of optimized 14 day sequential therapy and 10 day bismuth quadruple therapy containing high-dose esomeprazole in first-line therapy. We recruited 620 adult patients (≥20 years of age) with H. pylori infection naive to treatment in this multicentre, open-label, randomized trial. Patients were randomly assigned to receive 14 day sequential therapy or 10 day bismuth quadruple therapy, both containing esomeprazole 40 mg twice daily. Those who failed after 14 day sequential therapy received rescue therapy with 10 day bismuth quadruple therapy and vice versa. Our primary outcome was the eradication rate in the first-line therapy. Antibiotic susceptibility was determined. ClinicalTrials.gov: NCT03156855. The eradication rates of 14 day sequential therapy and 10 day bismuth quadruple therapy were 91.3% (283 of 310, 95% CI 87.4%-94.1%) and 91.6% (284 of 310, 95% CI 87.8%-94.3%) in the ITT analysis, respectively (difference -0.3%, 95% CI -4.7% to 4.4%, P = 0.886). However, the frequencies of adverse effects were significantly higher in patients treated with 10 day bismuth quadruple therapy than those treated with 14 day sequential therapy (74.4% versus 36.7% P < 0.0001). The eradication rate of 14 day sequential therapy in strains with and without 23S ribosomal RNA mutation was 80% (24 of 30) and 99% (193 of 195), respectively (P < 0.0001). Optimized 14 day sequential therapy was non-inferior to, but better tolerated than 10 day bismuth quadruple therapy and both may be used in first-line treatment in populations with low to intermediate clarithromycin resistance.

Tin-silver-bismuth solders for electronics assembly

DOEpatents

Vianco, Paul T.; Rejent, Jerome A.

1995-01-01

A lead-free solder alloy for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0

Tin-silver-bismuth solders for electronics assembly

DOEpatents

Vianco, P.T.; Rejent, J.A.

1995-08-08

A lead-free solder alloy is disclosed for electronic assemblies composed of a eutectic alloy of tin and silver with a bismuth addition, x, of 0

Burnout current density of bismuth nanowires

NASA Astrophysics Data System (ADS)

Cornelius, T. W.; Picht, O.; Müller, S.; Neumann, R.; Völklein, F.; Karim, S.; Duan, J. L.

2008-05-01

Single bismuth nanowires with diameters ranging from 100nmto1μm were electrochemically deposited in ion track-etched single-pore polycarbonate membranes. The maximum current density the wires are able to carry was investigated by ramping up the current until failure occurred. It increases by three to four orders of magnitude for nanowires embedded in the template compared to bulk bismuth and rises with diminishing diameter. Simulations show that the wires are heated up electrically to the melting temperature. Since the surface-to-volume ratio rises with diminishing diameter, thinner wires dissipate the heat more efficiently to the surrounding polymer matrix and, thus, can tolerate larger current densities.

Electromagnetic Pumps for Liquid Metal-Fed Electric Thrusters

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Markusic, Thomas E.

2007-01-01

Prototype designs of two separate pumps for use in electric propulsion systems with liquid lithium and bismuth propellants are presented. Both pumps are required to operate at elevated temperatures, and the lithium pump must additionally withstand the corrosive nature of the propellant. Compatibility of the pump materials and seals with lithium and bismuth were demonstrated through proof-of-concept experiments followed by post-experiment visual inspections. The pressure rise produced by the bismuth pump was found to be linear with input current and ranged from 0-9 kPa for corresponding input current levels of 0-30 A, showing good quantitative agreement with theoretical analysis.

Structural investigations of bismuth lead borosilicate glasses under the influence of gamma irradiation through ultrasonic studies

NASA Astrophysics Data System (ADS)

Bootjomchai, Cherdsak; Laopaiboon, Jintana; Laopaiboon, Raewat

2012-04-01

The ultrasonic velocity measurements for different compositions of irradiated bismuth lead borosilicate glasses xBi2O3-(50-x)PbO-20B2O3-30SiO2 (x=2, 4, 6, 8, and 10 mol.%) were performed at room temperature using pulse-echo technique. Densities of glass samples were measured by Archimedes' principle using n-hexane as the immersion liquid. The results from the studies show that ultrasonic velocity, elastic moduli, Poisson's ratio, microhardness, and the Debye temperature increase with increasing bismuth oxide content and increasing gamma-radiation dose (3-12 Gy).

Solid-state reaction synthesis for mixed-phase Eu3+-doped bismuth molybdate and its luminescence properties

NASA Astrophysics Data System (ADS)

Liang, Danyang; Ding, Yu; Wang, Nan; Cai, Xiaomeng; Li, Jia; Han, Linyu; Wang, Shiqi; Han, Yuanyuan; Jia, Guang; Wang, Liyong

2017-09-01

A method for mixed-phase bismuth molybdate doped with Eu3+ ions was developed by solid-state reaction assisting with polyvinyl alcohol (PVA). The results of powder X-ray diffraction showed a mixed-phase structure and the microscopical characterization technology revealed the formation process with the addition of PVA. As a structure inducer, the PVA molecules played a vital role in the formation of phase structure. The as-obtained Eu3+-doped bismuth molybdates were also characterized by using different spectroscopic techniques including FTIR and photoluminescence (PL). The results show that doping concentration, PVA addition and calcination temperature affect photoluminescence properties remarkably.

AC conductivity and dielectric properties of bulk tungsten trioxide (WO3)

NASA Astrophysics Data System (ADS)

El-Nahass, M. M.; Ali, H. A. M.; Saadeldin, M.; Zaghllol, M.

2012-11-01

AC conductivity and dielectric properties of tungsten trioxide (WO3) in a pellet form were studied in the frequency range from 42 Hz to 5 MHz with a variation of temperature in the range from 303 K to 463 K. AC conductivity, σac(ω) was found to be a function of ωs where ω is the angular frequency and s is the frequency exponent. The values of s were found to be less than unity and decrease with increasing temperature, which supports the correlated barrier hopping mechanism (CBH) as the dominant mechanism for the conduction in WO3. The dielectric constant (ε‧) and dielectric loss (ε″) were measured. The Cole-Cole diagram determined complex impedance for different temperatures.

Aromatic sulfonation with sulfur trioxide: mechanism and kinetic model.

PubMed

Moors, Samuel L C; Deraet, Xavier; Van Assche, Guy; Geerlings, Paul; De Proft, Frank

2017-01-01

Electrophilic aromatic sulfonation of benzene with sulfur trioxide is studied with ab initio molecular dynamics simulations in gas phase, and in explicit noncomplexing (CCl 3 F) and complexing (CH 3 NO 2 ) solvent models. We investigate different possible reaction pathways, the number of SO 3 molecules participating in the reaction, and the influence of the solvent. Our simulations confirm the existence of a low-energy concerted pathway with formation of a cyclic transition state with two SO 3 molecules. Based on the simulation results, we propose a sequence of elementary reaction steps and a kinetic model compatible with experimental data. Furthermore, a new alternative reaction pathway is proposed in complexing solvent, involving two SO 3 and one CH 3 NO 2 .

Arsenic trioxide induced rhabdomyolysis, a rare but severe side effect, in an APL patient: a case report.

PubMed

He, Haiyan; An, Ran; Hou, Jian; Fu, Weijun

2017-06-01

Arsenic trioxide (ATO), a component of the traditional Chinese medicine arsenic sublimate, promotes apoptosis and induces leukemic cell differentiation. Combined with all-trans-retinotic acid (ATRA), ATO has become the first-line induction therapy in treating acute promyelocytic leukemia (APL). The most common side effects of ATO include hepatotoxicity, gastrointestinal symptoms, water-sodium retention, and nervous system damage. In this report, we present a rare side effect, rhabdomyolysis, in a 68-year-old female APL patient who was treated with ATO. After taking 10 mg ATO daily for 6 days, she presented shortness of breath, myodynia, elevated creatine kinase, and acute renal insufficiency. This report describes the first case of ATO-induced rhabdomyolysis.

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2013 CFR

2013-04-01

... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2162 Bismuth oxychloride. (a) Identity and... following diluents: (i) For coloring cosmetics generally, only those diluents listed under § 73.1001(a)(1); (ii) For coloring externally applied cosmetics, only those diluents listed in § 73.1001(b) and, in...

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2012 CFR

2012-04-01

... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2162 Bismuth oxychloride. (a) Identity and... following diluents: (i) For coloring cosmetics generally, only those diluents listed under § 73.1001(a)(1); (ii) For coloring externally applied cosmetics, only those diluents listed in § 73.1001(b) and, in...

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2014 CFR

2014-04-01

... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2162 Bismuth oxychloride. (a) Identity and... following diluents: (i) For coloring cosmetics generally, only those diluents listed under § 73.1001(a)(1); (ii) For coloring externally applied cosmetics, only those diluents listed in § 73.1001(b) and, in...

Improvements to a Flow Sensor for Liquid Bismuth-Fed Hall Thrusters

NASA Technical Reports Server (NTRS)

Bonds, Kevin; Polzin, Kurt A.

2010-01-01

Recently, there has been significant interest in using bismuth metal as a propellant in Hall Thrusters [1, 2]. Bismuth offers some considerable cost, weight, and space savings over the traditional propellant--xenon. Quantifying the performance of liquid metal-fed Hall thrusters requires a very precise measure of the low propellant flow rates [1, 2]. The low flow rates (10 mg/sec) and the temperature at which free flowing liquid bismuth exists (above 300 C) preclude the use of off-the-shelf flow sensing equipment [3]. Therefore a new type of sensor is required. The hotspot bismuth flow sensor, described in Refs. [1-5] is designed to perform a flow rate measurement by measuring the velocity at which a thermal feature moves through a flow chamber. The mass flow rate can be determined from the time of flight of the thermal peak, [4, 5]. Previous research and testing has been concerned mainly with the generation of the thermal peak and it's subsequent detection. In this paper, we present design improvements to the sensor concept; and the results of testing conducted to verify the functionality of these improvements. A ceramic material is required for the sensor body (see Fig. 1), which must allow for active heating of the bismuth flow channel to keep the propellant in a liquid state. The material must be compatible with bismuth and must be bonded to conductive elements to allow for conduction of current into the liquid metal and measurement of the temperature in the flow. The new sensor requires fabrication techniques that will allow for a very small diameter flow chamber, which is required to produce useful measurements. Testing of various materials has revealed several that are potentially compatible with liquid bismuth. Of primary concern in the fabrication and testing of a robust, working prototype, is the compatibility of the selected materials with one another. Specifically, the thermal expansion rates of the materials relative to the ceramic body cannot expand so much as to cause cracks in the body or cause the bond between parts to delaminate. Those parts that will carry the current pulse must be electrically conductive while the sensor body must be an electrical insulator. Generally, the material choices as well as the sensor design must aid to preserve the integrity of the thermal feature to obtain accurate measurements. The present aim is to also incorporate, into the sensor body, an active heating arrangement based on ceramic heater technology similar to that used in semiconductor manufacturing.

Effect of the Different High Volume Fraction of SiC Particles on the Junction of Bismuthate Glass-SiCp/Al Composite

PubMed Central

Li, Xiaoqiang

2018-01-01

The in-house developed bismuthate glass and the SiCp/Al composites with different volume fractions of SiC particles (namely, 60 vol.%, 65 vol.%, 70 vol.%, and 75 vol.%) were jointed by vacuum hot-pressing process. The novel material can be used for the space mirror. The SiCp is an abbreviation for SiC particle. Firstly, the SiCp/Al composites with different vol.% of SiC particle were manufactured by using infiltration process. In order to obtain a stable bonding interface, the preoxide layers were fabricated on the surfaces of these composites for reacting with the bismuthate glass. The coefficient of thermal expansion (CTE) was carried out for characterizing the difference between the composites and bismuthate glass. The sealing quality of the composites and the bismuthate glass was quantified by using shear strength testing. The optical microstructures showed the particles were uniformly distributed in the Al matrix. The SEM image shows that a smooth oxidation layer was generated on the SiCp/Al composite. The CTE testing result indicated that the higher the vol.% of the particles in the composite, the lower the CTE value. The shear strength testing result disclosed that SiCp/Al composite with relatively low CTE value was favorable to obtain a bonding interface with high strength. PMID:29675118

Dietary intake of barium, bismuth, chromium, lithium, and strontium in a Spanish population (Canary Islands, Spain).

PubMed

González-Weller, Dailos; Rubio, Carmen; Gutiérrez, Ángel José; González, Gara Luis; Caballero Mesa, José María; Revert Gironés, Consuelo; Burgos Ojeda, Antonio; Hardisson, Arturo

2013-12-01

The aim of this study was to analyze barium, bismuth, chromium, lithium, and strontium contents in food and beverages consumed by the population of the Canary Islands (Spain) as well as determine dietary intake of these metals in the archipelago as a whole and in its individual islands. To this end, 440 samples were analyzed by ICP-OES and GFAAS. Barium concentrations ranged from 5.210 ± 2.117 mg/kg in nuts to 0.035 ± 0.043 mg/L in water. Viscera exhibited the highest levels of bismuth (38.07 ± 36.80 mg/kg). The cold meat and sausages group stood out for its high chromium concentrations (0.494 ± 0.257 mg/kg). The highest concentration of lithium and strontium came out in nuts (8.761 ± 5.368 mg/kg and 9.759 ± 5.181 mg/kg, respectively). The total intakes of barium, bismuth, chromium, lithium, and strontium were 0.685, 1.274, 0.087, 3.674, and 1.923 mg/day, respectively. Cereals turned out to contribute most to the dietary intake of barium, bismuth, chromium, and lithium in the Canary Islands, while fruit contributes most to the strontium intake. We also performed a metal intake study by age and sex of the population and compared the outcome with data from other regions, both national and international.

Sensitive voltammetric determination of lead released from ceramic dishes by using of bismuth nanostructures anchored on biochar.

PubMed

Agustini, Deonir; Mangrich, Antonio Salvio; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

2015-09-01

A simple and sensitive electroanalytical method was developed for determination of nanomolar levels of Pb(II) based on the voltammetric stripping response at a carbon paste electrode modified with biochar (a special charcoal) and bismuth nanostructures (nBi-BchCPE). The proposed methodology was based on spontaneous interactions between the highly functionalized biochar surface and Pb(II) ions followed by reduction of these ions into bismuth nanodots which promote an improvement on the stripping anodic current. The experimental procedure could be summarized in three steps: including an open circuit pre-concentration, reduction of accumulated lead ions at the electrode surface and stripping step under differential pulse voltammetric conditions (DPAdSV). SEM images revealed dimensions of bismuth nanodots ranging from 20 nm to 70 nm. The effects of main parameters related to biochar, bismuth and operational parameters were examined in detail. Under the optimal conditions, the proposed sensor has exhibited linear range from 5.0 to 1000 nmol L(-1) and detection limit of 1.41 nmol L(-1) for Pb(II). The optimized method was successfully applied for determination of Pb(II) released from overglaze-decorated ceramic dishes. Results obtained were compared with those given by inductively coupled plasma optical emission spectroscopy (ICP-OES) and they are in agreement at 99% of confidence level. Copyright © 2015. Published by Elsevier B.V.

Valley polarization in bismuth

NASA Astrophysics Data System (ADS)

Fauque, Benoit

2013-03-01

The electronic structure of certain crystal lattices can contain multiple degenerate valleys for their charge carriers to occupy. The principal challenge in the development of valleytronics is to lift the valley degeneracy of charge carriers in a controlled way. In bulk semi-metallic bismuth, the Fermi surface includes three cigar-shaped electron valleys lying almost perpendicular to the high symmetry axis known as the trigonal axis. The in-plane mass anisotropy of each valley exceeds 200 as a consequence of Dirac dispersion, which drastically reduces the effective mass along two out of the three orientations. According to our recent study of angle-dependent magnetoresistance in bismuth, a flow of Dirac electrons along the trigonal axis is extremely sensitive to the orientation of in-plane magnetic field. Thus, a rotatable magnetic field can be used as a valley valve to tune the contribution of each valley to the total conductivity. As a consequence of a unique combination of high mobility and extreme mass anisotropy in bismuth, the effect is visible even at room temperature in a magnetic field of 1 T. Thus, a modest magnetic field can be used as a valley valve in bismuth. The results of our recent investigation of angle-dependent magnetoresistance in other semi-metals and doped semiconductors suggest that a rotating magnetic field can behave as a valley valve in a multi-valley system with sizeable mass anisotropy.

Halloysite nanotubes as a solid sorbent in ultrasound-assisted dispersive micro solid-phase extraction for the determination of bismuth in water samples using high-resolution continuum source graphite-furnace atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Krawczyk-Coda, Magdalena

2017-03-01

In this research, a simple, accurate, and inexpensive preconcentration procedure was developed for the determination of bismuth in water samples, using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS). During the preconcentration step, halloysite nanotubes (HNTs) were used as a solid sorbent in ultrasound-assisted dispersive micro solid-phase extraction (USA DMSPE). The influence of the pH of the sample solution, amount of HNTs, and extraction time, as well as of the main parameters of HR CS GFAAS, on absorbance was investigated. The limit of detection was 0.005 μg L- 1. The preconcentration factor achieved for bismuth was 32. The relative standard deviation (RSD) was 4%. The accuracy of this method was validated by analyses of NIST SRM 1643e (Trace elements in water) and TMDA-54.5 (A high level fortified sample for trace elements) certified reference materials. The measured bismuth contents in these certified reference materials were in satisfactory agreement with the certified values according to the t-test for a 95% confidence level. The proposed method has been successfully applied to the determination of bismuth in five different real water samples (seawater, lake water, river water, stream water and rain water).

Effect of the Different High Volume Fraction of SiC Particles on the Junction of Bismuthate Glass-SiCp/Al Composite.

PubMed

Wang, Bin; Qu, Shengguan; Li, Xiaoqiang

2018-01-01

The in-house developed bismuthate glass and the SiC p /Al composites with different volume fractions of SiC particles (namely, 60 vol.%, 65 vol.%, 70 vol.%, and 75 vol.%) were jointed by vacuum hot-pressing process. The novel material can be used for the space mirror. The SiCp is an abbreviation for SiC particle. Firstly, the SiC p /Al composites with different vol.% of SiC particle were manufactured by using infiltration process. In order to obtain a stable bonding interface, the preoxide layers were fabricated on the surfaces of these composites for reacting with the bismuthate glass. The coefficient of thermal expansion (CTE) was carried out for characterizing the difference between the composites and bismuthate glass. The sealing quality of the composites and the bismuthate glass was quantified by using shear strength testing. The optical microstructures showed the particles were uniformly distributed in the Al matrix. The SEM image shows that a smooth oxidation layer was generated on the SiC p /Al composite. The CTE testing result indicated that the higher the vol.% of the particles in the composite, the lower the CTE value. The shear strength testing result disclosed that SiC p /Al composite with relatively low CTE value was favorable to obtain a bonding interface with high strength.

Effect of bismuth subcitrate and sucralfate on rat duodenal and human gastric bicarbonate secretion in vivo.

PubMed Central

Shorrock, C J; Garner, A; Hunter, A H; Crampton, J R; Rees, W D

1990-01-01

Acid and alkali secretion have been examined together with prostaglandin E2 production in response to two mucosal protective drugs, colloidal bismuth subcitrate and sucralfate. Doses of colloidal bismuth subcitrate in the therapeutic range (120 and 1200 mg) had no effect on alkali secretion or luminal PGE2 output when perfused into the stomach of human volunteers. Similarly, in the anaesthetised rat, neither gastric acid nor duodenal alkali secretions were influenced by iv (12 mg/kg) or topical (120 mg/ml) administration of colloidal bismuth subcitrate. In contrast, perfusion of the human stomach with 1 g sucralfate stimulated bicarbonate output by 50%, a response which was unaffected by indomethacin (25 mg/h). A rise of 64% in gastric PGE2 output after sucralfate was, however, prevented by indomethacin pretreatment. Alkali secretion by rat duodenum was also increased by sucralfate but the response depended on the basal secretory rate. Low basal secretors (less than 3 mumol) showed a 75% stimulation whereas rats with high basal secretory rates (greater than 3 mumol) showed no significant response. All duodenal preparations regardless of basal secretory rate showed a stimulation of bicarbonate output with topical PGE2. The results suggest that enhancement of gastroduodenal bicarbonate secretion may play a role in the protective action of sucralfate but is unlikely to explain mucosal protection by colloidal bismuth subcitrate. PMID:2318428

Third order nonlinear optical properties of bismuth zinc borate glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shanmugavelu, B.; Ravi Kanth Kumar, V. V., E-mail: ravi.phy@pondiuni.edu.in; Kuladeep, R.

2013-12-28

Third order nonlinear optical characterization of bismuth zinc borate glasses are reported here using different laser pulse durations. Bismuth zinc borate glasses with compositions xBi{sub 2}O{sub 3}-30ZnO-(70-x) B{sub 2}O{sub 3} (where x = 30, 35, 40, and 45 mol. %) have been prepared by melt quenching method. These glasses were characterized by Raman, UV-Vis absorption, and Z scan measurements. Raman and UV-Vis spectroscopic results indicate that non-bridging oxygens increase with increase of bismuth content in the glass. Nonlinear absorption and refraction behavior in the nanosecond (ns), picosecond (ps), and femtosecond (fs) time domains were studied in detail. Strong reverse saturable absorption due tomore » dominant two-photon absorption (TPA) was observed with both ps and fs excitations. In the case of ns pulse excitations, TPA and free-carrier absorption processes contribute for the nonlinear absorption. Two-photon absorption coefficient (β) and the absorption cross section due to free carriers (σ{sub e}) are estimated by theoretical fit of the open aperture Z-scan measurements and found to be dependent on the amount of bismuth oxide in the glass composition. In both ns and fs regimes the sign and magnitude of the third order nonlinearity are evaluated, and the optical limiting characteristics are also reported.« less

Effect of Post-annealing on the Electrochromic Properties of Layer-by-Layer Arrangement FTO-WO3-Ag-WO3-Ag

NASA Astrophysics Data System (ADS)

Hoseinzadeh, S.; Ghasemiasl, R.; Bahari, A.; Ramezani, A. H.

2018-03-01

In the current study, composites of tungsten trioxide (W03) and silver (Ag) are deposited in a layer-by-layer electrochromic (EC) arrangement onto a fluorine-doped tin oxide coated glass substrate. Tungsten oxide nanoparticles are an n-type semiconductor that can be used as EC cathode material. Nano-sized silver is a metal that can serve as an electron trap center that facilitates charge departure. In this method, the WO3 and Ag nanoparticle powder were deposited by physical vapor deposition onto the glass substrate. The fabricated electrochromic devices (ECD) were post-annealed to examine the effect of temperature on their EC properties. The morphology of the thin film was characterized by scanning electron microscopy and atomic force microscopy. Structural analysis showed that the addition of silver dopant increased the size of the aggregation of the film. The film had an average approximate roughness of about 17.8 nm. The electro-optical properties of the thin film were investigated using cyclic voltammetry and UV-visible spectroscopy to compare the effects of different post-annealing temperatures. The ECD showed that annealing at 200°C provided better conductivity (maximum current of about 90 mA in the oxidation state) and change of transmittance (ΔT = 90% at the continuous switching step) than did the other thin films. The optical band gaps of the thin film showed that it allowed direct transition at 3.85 eV. The EC properties of these combinations of coloration efficiency and response time indicate that the WO3-Ag-WO3-Ag arrangement is a promising candidate for use in such ECDs.

21 CFR 73.2162 - Bismuth oxychloride.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Bismuth oxychloride. 73.2162 Section 73.2162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF... following diluents: (i) For coloring cosmetics generally, only those diluents listed under § 73.1001(a)(1...

21 CFR 73.1162 - Bismuth oxychloride.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Bismuth oxychloride. 73.1162 Section 73.1162 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF... subpart as safe in color additive mixtures for coloring externally applied drugs. (b) Specifications. The...

Ultrathin Lutetium Oxide Film as an Epitaxial Hole-Blocking Layer for Crystalline Bismuth Vanadate Water Splitting Photoanodes

DOE PAGES

Zhang, Wenrui; Yan, Danhua; Tong, Xiao; ...

2018-01-08

Here a novel ultrathin lutetium oxide (Lu 2O 3) interlayer is integrated with crystalline bismuth vanadate (BiVO4) thin film photoanodes to facilitate carrier transport through atomic-scale interface control. The epitaxial Lu 2O 32O 3

Stabilized Alkali-Metal Ultraviolet-Band-Pass Filters

NASA Technical Reports Server (NTRS)

Mardesich, Nick; Fraschetti, George A.; Mccann, Timothy; Mayall, Sherwood D.; Dunn, Donald E.; Trauger, John T.

1995-01-01

Layers of bismuth 5 to 10 angstrom thick incorporated into alkali-metal ultraviolet-band-pass optical filters by use of advanced fabrication techniques. In new filters layer of bismuth helps to reduce surface migration of sodium. Sodium layer made more stable and decreased tendency to form pinholes by migration.

Bismuth Oxide Nanoparticles in the Stratosphere

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.; Mackinnon, Ian D. R.

1997-01-01

Platey grains of cubic Bi2O3, alpha-Bi2O3, and Bi2O(2.75), nanograins were associated with chondritic porous interplanetary dust particles W7029C1, W7029E5, and 2011C2 that were collected in the stratosphere at 17-19 km altitude. Similar Bi oxide nanograins were present in the upper stratosphere during May 1985. These grains are linked to the plumes of several major volcanic eruptions during the early 1980s that injected material into the stratosphere. The mass of sulfur from these eruptions is a proxy for the mass of stratospheric Bi from which we derive the particle number densities (p/cu m) for "average Bi2O3 nanograins" due to this volcanic activity and those necessary to contaminate the extraterrestrial chondritic porous interplanetary dust particles via collisional sticking. The match between both values supports the idea that Bi2O3 nanograins of volcanic origin could contaminate interplanetary dust particles in the Earth's stratosphere.

Multiferroics BiMn1-xAlxO3 nanoparticles: Synthesis, characterization and evaluation of various structural, physical, electrical and dielectric parameters

NASA Astrophysics Data System (ADS)

Ahmad, Bashir; Raissat, Rabia; Mumtaz, Saleem; Ahmad, Zahoor; Sadiq, Imran; Ashiq, Muhammad Naeem; Najam-ul-Haq, Muhammad

2017-07-01

The aluminium substituted bismuth based manganates with nominal composition BiMn1-xAlxO3 (x = 0.0, 0.2, 0.4, 0.6 and 0.8) were prepared by the simple microemulsion method. The alteration in their structural, electrical and dielectric parameters due to Al substitution has been investigated. The X-ray diffraction analysis (XRD) confirms the formation of single phase orthorhombic with crystallite size ranges from 32 to 52 nm. The morphological features and particle size were determined by using scanning electron microscopy (SEM). The dc electrical resistivity increased from 6 × 108 to 8 × 109 Ω cm with the increase in substituent concentration. The dielectric constant, dielectric loss tangent and dielectric loss factor decreased with the increase in frequency. The increase in electrical resistivity makes the synthesized materials paramount over other materials and can be useful for technological applications in microwave devices.

Preparation of Nano-sized Bismuth-Doped Fe3O4 as an Excellent Magnetic Material for Supercapacitor Electrodes

NASA Astrophysics Data System (ADS)

Aghazadeh, Mustafa; Karimzadeh, Isa; Ganjali, Mohammad Reza

2018-03-01

Nano-sized Bi3+-doped iron oxide (n-Bi-IO) particles were prepared through a one-pot electrochemical procedure, and the product was evaluated using x-ray diffraction, field-emission scanning electron microscopy and energy-dispersive x-ray spectroscopy. Based on the analyses, the average size of the n-Bi-IO was determined to be 10 nm. Galvanostatic charge-discharge (GCD) evaluations revealed that the specific capacitance of the material reached 235 F g-1 at a discharge condition of 0.2 A g-1. n-Bi-IO had a 94.2% capacity retention after 2000 GCD cycles. Further vibrating sample magnetometery analyses showed that the product has enhanced superparamagnetic qualities (i.e. M r = 0.15 emu g-1 and H Ci = 2.71 G) in comparison to iron oxide nanoparticles (i.e. M r = 0.95 emu g-1 and H Ci = 14.62 G). Given the results, the product is considered to be a promising material for developing high performance supercapacitor electrodes.

Bismuth pyrochlore-based thin films for dielectric energy storage

NASA Astrophysics Data System (ADS)

Michael, Elizabeth K.

The drive towards the miniaturization of electronic devices has created a need for dielectric materials with large energy storage densities. These materials, which are used in capacitors, are a critical component in many electrical systems. Here, the development of dielectric energy storage materials for pulsed power applications, which require materials with the ability to accumulate a large amount of energy and then deliver it to the system rapidly, is explored. The amount of electrostatic energy that can be stored by a material is a function of the induced polarization and the dielectric breakdown strength of the material. An ideal energy storage dielectric would possess a high relative permittivity, high dielectric breakdown strength, and low loss tangent under high applied electric fields. The bismuth pyrochlores are a compositionally tunable family of materials that meet these requirements. Thin films of cubic pyrochlore bismuth zinc niobate, bismuth zinc tantalate, and bismuth zinc niobate tantalate, were fabricated using a novel solution chemistry based upon the Pechini method. This solution preparation is advantageous because it avoids the use of teratogenic solvents, such as 2-methoxyethanol. Crystalline films fabricated using this solution chemistry had very small grains that were approximately 27 nm in lateral size and 35 nm through the film thickness. Impedance measurements found that the resistivity of the grain boundaries was two orders of magnitude higher than the resistivity of the grain interior. The presence of many resistive grain boundaries impeded conduction through the films, resulting in high breakdown strengths for these materials. In addition to high breakdown strengths, this family of materials exhibited moderate relative permittivities of between 55 +/- 2 and 145 +/- 5, for bismuth zinc tantalate and bismuth zinc niobate, respectively, and low loss tangents on the order of 0.0008 +/- 0.0001. Increases in the concentration of the tantalum end member increased the dielectric breakdown strength. This combination of a high breakdown strength and a moderate permittivity led to a high discharged energy storage density for all film compositions. For example, at a measurement frequency of 10 kHz, bismuth zinc niobate exhibited a maximum recoverable energy storage density of 60.8 +/- 2.0 J/cm 3, while bismuth zinc tantalate exhibited a recoverable energy storage density of 60.7 +/- 2.0 J/cm3. Intermediate compositions of bismuth zinc niobate tantalate were explored to maximize the energy storage density of the substitutional solid solution. At an optimized concentration of ten mole percent tantalum, the maximum recoverable 10 kHz energy storage density was ˜66.9 +/- 2.4 J/cm3. These films of bismuth zinc niobate tantalate (Bi1.5Zn0.9Nb1.35Ta0.15O 6.9) sustained a maximum field of 5.5 MV/cm at 10 kHz, and demonstrated a relative permittivity of 122 +/- 4. The films maintained a high energy storage density above 20 J/cm3 though temperatures of 200°C. The second major objective of this work was to integrate complex oxides processed at temperatures below 350°C onto flexible polyimide substrates for potential use in flexible energy storage applications. Nanocomposite films consisting of a nanocrystalline fluorite related to delta-bismuth oxide in an amorphous matrix were prepared by reducing the citric acid concentration of the precursor solution, relative to the crystalline films. These solutions were batched with the composition Bi1.5Zn0.9Nb 1.35Ta0.15O6.9. The nanocomposite had a relative permittivity of 50 +/- 2 and dielectric losses on the order of 0.03 +/- 0.01. For measurement frequencies of 1 kHz and 10 kHz, the nanocomposite demonstrated a breakdown strength of 3.8 MV/cm, and a room-temperature energy storage density of approximately 40.2 +/- 1.7 J/cm3. To determine the suitability of the nanocomposite films for use in flexible applications, free-standing flexible nanocomposite films underwent repetitive compressive and tensile bending around a minimum bend diameter of 7 mm, which corresponded to a strain of 0.10%. After bending the films 30,000 times, the energy storage density of the films was unchanged, indicating that nanocomposite bismuth zinc niobate tantalate films may be suitable for flexible energy storage applications. To demonstrate the broader applicability of the nanocomposite approach to developing energy storage dielectrics at low processing temperatures, films of nanocomposite lead titanate, Pb1.1TiO3.1, were deposited using an inverted mixing order solution preparation, and annealed at a maximum temperature of 400°C. X-ray diffraction indicated the presence of nanocrystalline ordering, and transmission electron microscopy confirmed the nucleation of isolated nanocrystals of lead oxide in an amorphous lead titanate matrix. (Abstract shortened by UMI.).

The effect of sodium hypochlorite application on the success of calcium hydroxide and mineral trioxide aggregate pulpotomies in primary teeth.

PubMed

Akcay, Merve; Sari, Saziye

2014-01-01

This study's purpose was to evaluate the success of calcium hydroxide (CH) and mineral trioxide aggregate (MTA) pulpotomies following the use of five percent sodium hypochlorite (NaOCl) as an antibacterial agent to clean the chamber prior to application of the pulpotomy agent. A total of 128 teeth were randomly divided into two pulpotomy groups (CH or MTA). The teeth in each pulpotomy group, CH and MTA, were further randomly divided into subgroups to receive either the NaOCl (experimental) or saline (control) cleaning agent prior to applying the pulpotomy agent. The treatments were followed clinically and radiographically for 12 months. The radiographic success rates were 84 percent for CH NaOCl, 74 percent for CH saline control, 97 percent for MTA NaOCl, and 100 percent for MTA saline control. There were no significant differences between the radiographic success rates in the CH and MTA subgroups (CH NaOCl-CH control and MTA NaOCl-MTA control); no significant differences were observed when comparing the CH NaOCl-MTA NaOCl groups and the CH NaOCl-MTA control groups. Use of sodium hypochlorite as an antibacterial agent prior to application of the pulpotomy agent improved the success of calcium hydroxide pulpotomies to equal the success of mineral trioxide aggregate pulpotomies for observation up to 12 months.

Comparison of Mineral Trioxide Aggregate and Diluted Formocresol in Pulpotomized Human Primary Molars: 42-month Follow-up and Survival Analysis

PubMed Central

Mettlach, Sarah E.; Zealand, Cameron M.; Botero, Tatiana M.; Boynton, James R.; Majewski, Robert F.; Hu, Jan ChingChun

2015-01-01

Purpose The purpose of this study was to test the hypothesis that there is no significant difference in the clinical and radiographic outcomes of diluted formocresol (DFC) compared to gray mineral trioxide aggregate (GMTA) pulpotomy in human primary molars. Methods A total of 152 children with 252 primary molars met selection criteria. Of those, 119 and 133 teeth were randomly assigned to the GMTA and DFC groups, respectively. Periapical radiographs, taken pre- and/or postoperatively and at each 6-month follow-up, were digitized and evaluated by three blinded and calibrated examiners. Results Over a 42-month period, a total of 865 clinical and radiographic evaluations were conducted. There was no significant difference in clinical success, with the cumulative proportion of GMTA-treated teeth surviving at 0.98 vs DFC-treated teeth at 0.95 (P>.05). Radiographic success, however, was significantly greater for GMTA vs DFC, with the cumulative proportion of GMTA-treated teeth surviving at 0.90 vs DFC-treated teeth at 0.47 (P<.001). Overall, DFC-treated teeth were 5.1 times more likely to fail than GMTA-treated teeth. Radiographic pathologies were observed more frequently in the DFC-treated teeth (P<.05). Conclusion Gray mineral trioxide aggregate can be considered an acceptable replacement for diluted formocresol when used as a medicament for primary molar pulpotomies. PMID:23756301

Comparison of Ferric Sulfate Combined Mineral Trioxide Aggregate Pulpotomy and Zinc Oxide Eugenol Pulpectomy of Primary Maxillary Incisors: An 18-month Randomized, Controlled Trial.

PubMed

Nguyen, Trang D; Judd, Peter L; Barrett, Edward J; Sidhu, Nicole; Casas, Michael J

2017-01-15

The purpose of this study was to compare outcomes and survival of ferric sulfate with mineral trioxide aggregate (FS+MTA) pulpotomy and root canal therapy (RCT) in carious vital primary maxillary incisors. In this parallel group noninferiority trial, asymptomatic carious vital primary incisors with pulp exposure in healthy 18- to 46-month-olds were allocated randomly to receive FS+MTA pulpotomy or RCT between September 2010 and September 2012. Each incisor was classified into one of the following radiographic outcomes: N (incisor without pathologic change); Po (pathologic change present, follow-up recommended); Px (pathologic change present, extract.) Clinical findings and incisor survival were secondary outcomes. Seventy subjects were enrolled with a total of 172 incisors. Twelve- and 18-month radiographic outcomes demonstrated no statistical difference between FS+MTA pulpotomy and RCT incisors for Px outcomes (P=0.38; odds ratio equals 0.60; 95 percent confidence interval equals 0.19 to 1.89; chi-square test). There was no statistical differences in clinical outcomes for FS+MTA pulpotomy and RCT at 12 and 18 months (P=0.51; Fisher's exact test) or survival for FS+MTA pulpotomy and RCT incisors (P=0.11; log-rank test). Ferric Sulfate with Mineral Trioxide Aggregate (FS+MTA) is an alternative to RCT for vital primary incisors.

Effect of white mineral trioxide aggregate compared with biomimetic carbonated apatite on dentine bridge formation and inflammatory response in a dental pulp model.

PubMed

Danesh, F; Vahid, A; Jahanbani, J; Mashhadiabbas, F; Arman, E

2012-01-01

  To evaluate the effects of apatite precipitation on the biocompatibility and hard tissue induction properties of white mineral trioxide aggregate (WMTA) in a dental pulp model.   Pulp exposures were created on the axial walls of 32 sound canine teeth of eight dogs. Four additional sound teeth served as controls. The pulps were capped either with WMTA or apatite derivatives [biomimetic carbonated apatite (BCAp)] in the interaction of WMTA with a synthetic tissue fluid and restored with zinc oxide-eugenol cement. After 7 and 70 days, the animals were killed, and the histological specimens taken from the teeth were stained with haematoxylin and eosin for histomorphological evaluation. The Brown and Brenn technique was employed to stain bacteria. The data were subjected to nonparametric Kruskall-Wallis analysis and Mann-Whitney U_tests.   Biomimetic carbonated apatite did not induce hard tissue bridge formation. WMTA performed significantly better than BCAp in this respect at both periods (P < 0.05). BCAp was associated with a significantly greater inflammatory response as compared with WMTA after 7 days (P < 0.05). Both materials were associated with similar reactions after 70 days (P >0.05).   White mineral trioxide aggregate induced hard tissue formation via a mechanism other than that postulated via apatite formation. © 2011 International Endodontic Journal.

Comparison of gray mineral trioxide aggregate and diluted formocresol in pulpotomized primary molars: a 6- to 24-month observation.

PubMed

Sushynski, John M; Zealand, Cameron M; Botero, Tatiana M; Boynton, James R; Majewski, Robert F; Shelburne, Charles E; Hu, Jan Chingchun

2012-01-01

The purpose of this multisite, multioperator, prospective, randomized, controlled clinical trial was to evaluate 2-year outcomes of diluted formocresol (DFC) compared to gray mineral trioxide aggregate (GMTA) as pulpotomy medicaments. Following the standard pulpotomy procedure, the pulp stumps of 252 primary molars in 168 healthy children were randomly covered with GMTA or DFC. Pulp chambers were filled with Intermediate Restorative Material (IRM(®)) and teeth were restored with stainless steel crowns. At each follow-up appointment, the clinical status of the treated tooth was assessed and radiographs were taken. A total of 694 clinical and radiographic evaluations were analyzed. Gender, study site, arch type, and tooth type did not influence treatment outcome. At the combined 6- to 24-month follow-up, clinical success in the DFC group was no different than for the GMTA group. Radiographically, a significantly lower success rate was found in the DFC group vs the MTA group at all time points (P<.01). Dentin bridge formation was observed at a significantly higher frequency among the GMTA group (P<.01), while internal root resorption was observed at a higher frequency in the DFC group (P<.01). At the combined 6- to 24-month follow-up, gray mineral trioxide aggregate demonstrated significantly better radiographic outcomes vs diluted formocresol as pulpotomy medicaments.

Mixed-layered bismuth-oxygen-iodine materials for capture and waste disposal of radioactive iodine

DOEpatents

Krumhansl, James L; Nenoff, Tina M

2013-02-26

Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility in groundwater environments.

Electrolytic Polishing and Etching Techniques for Preparing Specimens of Bismuth and Antimony and Their Alloys: Materials and Structures.

DTIC Science & Technology

Electrolytic polishing was performed in a solution of methyl alcohol, sulphuric acid , hydrocloric acid and ethylene glycol. Etching was done...electrolytically in a 5 percent chromic acid solution. Use of these techniques has permitted detailed studies of the microstructures of bismuth-antimony single

Bismuth(III) trifluoromethanesulfonate catalyzed ring opening reaction of mono epoxy oleochemicals to form keto and diketo derivatives

USDA-ARS?s Scientific Manuscript database

Using a catalytic system, methyl oleate is transformed into long chain keto and diketo derivatives via an epoxide route. Methyl 9(10)-oxooctadecanoate and methyl 9,10-dioxooctadecanoate were made by a ring opening reaction of epoxidized methyl oleate using bismuth triflate catalyst. Lower reaction t...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

21 CFR 73.2110 - Bismuth citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the scalp...

SEPARATION OF FISSION PRODUCT VALUES FROM THE HEXAVALENT PLUTONIUM BY CARRIER PRECIPITATION

DOEpatents

Davies, T.H.

1959-12-15

An improved precipitation of fission products on bismuth phosphate from an aqueous mineral acid solution also containing hexavalent plutonium by incorporating, prior to bismuth phosphate precipitation, from 0.05 to 2.5 grams/ liter of zirconium phosphate, niobium oxide. and/or lanthanum fluoride is described. The plutonium remains in solution.

The effects of EF-Ts and bismuth on EF-Tu in Helicobacter pylori: implications for an elegant timing for the introduction of EF-Ts in the elongation and EF-Tu as a potential drug target.

PubMed

Wang, Dongxian; Luo, Benping; Shan, Weiran; Hao, Mingcong; Sun, Xuesong; Ge, Ruiguang

2013-06-01

Helicobacter pylori is a common human pathogen responsible for various gastric diseases. Bismuth can effectively inhibit the growth of this bacterium and is commonly recommended for the treatment of the related diseases. Translation elongation factors EF-Tu and EF-Ts are two important components of the protein translation system. EF-Ts has inhibitory effects on the GTPase activity of EF-Tu and enhances GDP release, a hint that careful timing for the introduction of EF-Ts in the elongation should be accomplished to prevent the complete inhibition of the elongation process. Bismuth inhibits the chaperone activity of EF-Tu, and has opposite effects on the elongation activity: inhibitory effects on the intrinsic GTPase activity and stimulation of GDP release. The present work deepens our understanding of the bacterial elongation process as mediated by EF-Tu and EF-Ts and extends our knowledge about the inhibitory effects of bismuth-based drugs against Helicobacter pylori.

Oxide layer stability in lead-bismuth at high temperature

NASA Astrophysics Data System (ADS)

Martín, F. J.; Soler, L.; Hernández, F.; Gómez-Briceño, D.

2004-11-01

Materials protection by 'in situ' oxidation has been studied in stagnant lead-bismuth, with different oxygen levels (H 2/H 2O ratios of 0.3 and 0.03), at temperatures from 535 °C to 600 °C and times from 100 to 3000 h. The materials tested were the martensitic steels F82Hmod, EM10 and T91 and the austenitic stainless steels, AISI 316L and AISI 304L. The results obtained point to the existence of an apparent threshold temperature above which corrosion occurs and the formation of a protective and stable oxide layer is not possible. This threshold temperature depends on material composition, oxygen concentration in the liquid lead-bismuth and time. The threshold temperature is higher for the austenitic steels, especially for the AISI 304L, and it increases with the oxygen concentration in the lead-bismuth. The oxide layer formed disappear with time and, after 3000 h all the materials, except AISI 304L, suffer corrosion, more severe for the martensitic steels and at the highest temperature tested.

Use of a Soluble Anode in Electrodeposition of Thick Bismuth Telluride Layers

NASA Astrophysics Data System (ADS)

Maas, M.; Diliberto, S.; de Vaulx, C.; Azzouz, K.; Boulanger, C.

2014-10-01

Integration of thermoelectric devices within an automotive heat exchanger could enable conversion of lost heat into electrical energy, contributing to improved total output from the engine. For this purpose, synthesis of thick bismuth telluride (Bi2Te3) films is required. Bismuth telluride has been produced by an electrochemical method in nitric acid with a sacrificial bismuth telluride anode as the source of cations. The binary layer grows on the working electrode while the counter-electrode, a Bi2Te3 disk obtained by high frequency melting, is oxidized to BiIII and TeIV. This process leads to auto-regeneration of the solution without modification of its composition. The thickness of films deposited by use of the Bi2Te3 anode was approximately 10 times that without. To demonstrate the utility of a soluble anode in electrochemical deposition, we report characterization of the composition and morphology of the films obtained under different experimental conditions. Perfectly dense and regular Bi2Te3 films (˜400 μm) with low internal stress and uniform composition across the cross-section were prepared. Their thermoelectric properties were assessed.

Electromagnetic Pumps for Conductive-Propellant Feed Systems

NASA Technical Reports Server (NTRS)

Markusic, Thomas E.; Polzin, Kurt A.; Dehoyos, Amado

2005-01-01

Prototype electromagnetic pumps for use with lithium and bismuth propellants were constructed and tested. Such pumps may be used to pressurize future electric propulsion liquid metal feed systems, with the primary advantages being the compactness and simplicity versus alternative pressurization technologies. Design details for two different pumps are described: the first was designed to withstand (highly corrosive) lithium propellant, and t he second was designed to tolerate the high temperature required to pump liquid bismuth. Both qualitative and quantitative test results are presented. Open-loop tests demonstrated the capability of each device to electromagnetically pump its design propellant (lithium or bismuth). A second set of tests accurately quantified the pump pressure developed as a function of current. These experiments, which utilized a more easily handled material (gallium), demonstrated continuously-adjustable pump pressure levels ranging from 0-100 Torr for corresponding input current levels of 0-75 A. While the analysis and testing in this study specifically targeted lithium and bismuth propellants, the underlying design principles should be useful in implementing liquid metal pumps in any conductive-propellant feed system.

ANION EXCHANGE METHOD FOR SEPARATION OF METAL VALUES

DOEpatents

Hyde, E.K.; Raby, B.A.

1959-02-10

A method is described for selectively separating radium, bismuth, poloniums and lead values from a metallic mixture of thc same. The mixture is dissolved in aqueous hydrochloric acid and the acidity is adjusted to between 1 to 2M in hydrochloric acid to form the anionic polychloro complexes of polonium and bismuth. The solution is contacted with a first anion exchange resin such as strong base quaternary ammonia type to selectively absorb the polonium and bismuth leaving the radium and lead in the effluent. The effluent, after treatment in hydrochloric acid to increase the hydrochloric acid concentration to 6M is contacted with a second anion exchange iesin of the same type as the above to selectively adsorb the lead leaving the radium in the effluent. Radium is separately recovered from the effluent from the second exchange column. Lead is stripped from the loaded resin of the second column by treatment with 3M hydrochloric acid solution. The loaded resin of the first column is washed with 8M hydrochloric acid solution to recover bismuth and then treated with strong nitric acid solution to recover polonium.

Atomic Layer Deposition of Bismuth Vanadates for Solar Energy Materials.

PubMed

Stefik, Morgan

2016-07-07

The fabrication of porous nanocomposites is key to the advancement of energy conversion and storage devices that interface with electrolytes. Bismuth vanadate, BiVO4 , is a promising oxide for solar water splitting where the controlled fabrication of BiVO4 layers within porous, conducting scaffolds has remained a challenge. Here, the atomic layer deposition of bismuth vanadates is reported from BiPh3 , vanadium(V) oxytriisopropoxide, and water. The resulting films have tunable stoichiometry and may be crystallized to form the photoactive scheelite structure of BiVO4 . A selective etching process was used with vanadium-rich depositions to enable the synthesis of phase-pure BiVO4 after spinodal decomposition. BiVO4 thin films were measured for photoelectrochemical performance under AM 1.5 illumination. The average photocurrents were 1.17 mA cm(-2) at 1.23 V versus the reversible hydrogen electrode using a hole-scavenging sulfite electrolyte. The capability to deposit conformal bismuth vanadates will enable a new generation of nanocomposite architectures for solar water splitting. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Time-resolved spectroscopy and optical gain of silica-based fibers co-doped with Bi, Al and/or Ge, P, and Ti

NASA Astrophysics Data System (ADS)

Firstov, S. V.; Bufetov, I. A.; Khopin, V. F.; Umnikov, A. A.; Guryanov, A. N.; Dianov, E. M.

2009-04-01

The optical properties of optical fibers based on silica glass doped with bismuth and co-doped with aluminum oxides and/or germanium, phosphorus, and titanium oxides are studied. The optical loss and luminescence spectra of optical fibers substantially depend on the core composition. The gain spectra of single-mode optical fibers are measured in the IR range. It is demonstrated that the phosphorus-germanium-silicate optical fiber doped with bismuth exhibits a broad gain band (1270-1520 nm) when pumped at a wavelength of 1230 nm. It is also shown that the bismuth-aluminosilicate optical fibers additionally doped with Ge or Ti at about 1 at % have the gain spectra that are significantly narrower than the IR luminescence spectra (in contrast to the fibers that do not contain Ge and Ti). The intensity decay curves of the IR luminescence in such fibers indicate the presence of both short-lived (with the lifetime τ≤4 μs) and long-lived (τ ˜ 1 ms) energy levels in the bismuth active centers.

Bismuth Oxysulfide and Its Polymer Nanocomposites for Efficient Purification

PubMed Central

Luo, Yidong; Qiao, Lina; Wang, Huanchun; Lan, Shun; Shen, Yang; Lin, Yuanhua; Nan, Cewen

2018-01-01

The danger of toxic organic pollutants in both aquatic and air environments calls for high-efficiency purification material. Herein, layered bismuth copper oxychalcogenides, BiCuSO, nanosheets of high photocatalytic activity were introduced to the PVDF (Polyvinylidene Fluoride). The fibrous membranes provide an easy, efficient, and recyclable way to purify organic pollutant. The physical and photophysical properties of the BiCuSO and its polymer composite were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet-visible diffuse reflection spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), electron spin resonance (EPR). Photocatalysis of Congo Red reveals that the BiCuSO/PVDF shows a superior photocatalytic activity of a 55% degradation rate in 70 min at visible light. The high photocatalytic activity is attributed to the exposed active {101} facets and the triple vacant associates VBi‴VO••VBi‴. By engineering the intrinsic defects on the surface of bismuth oxysulfide, high solar-driven photocatalytic activity can be approached. The successful fabrication of the bismuth oxysulfide and its polymer nanocomposites provides an easy and general approach for high-performance purification materials for various applications. PMID:29562701

Synthesis and Characterisation of Reduced Graphene Oxide/Bismuth Composite for Electrodes in Electrochemical Energy Storage Devices.

PubMed

Wang, Jiabin; Zhang, Han; Hunt, Michael R C; Charles, Alasdair; Tang, Jie; Bretcanu, Oana; Walker, David; Hassan, Khalil T; Sun, Yige; Šiller, Lidija

2017-01-20

A reduced graphene oxide/bismuth (rGO/Bi) composite was synthesized for the first time using a polyol process at a low reaction temperature and with a short reaction time (60 °C and 3 hours, respectively). The as-prepared sample is structured with 20-50 nm diameter bismuth particles distributed on the rGO sheets. The rGO/Bi composite displays a combination of capacitive and battery-like charge storage, achieving a specific capacity value of 773 C g -1 at a current density of 0.2 A g -1 when charged to 1 V. The material not only has good power density but also shows moderate stability in cycling tests with current densities as high as 5 A g -1 . The relatively high abundance and low price of bismuth make this rGO/Bi material a promising candidate for use in electrode materials in future energy storage devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microwave spectra and quadrupole coupling measurements for methyl rhenium trioxide

NASA Astrophysics Data System (ADS)

Sickafoose, S. M.; Wikrent, P.; Drouin, B. J.; Kukolich, S. G.

1996-12-01

Microwave rotational transitions for J' ← J = 1 ← 0 and 2 ← 1 were measured in the 6-14 GHz range for methyl rhenium trioxide using a Flygare-Balle type, pulsed-beam spectrometer. The rotational constants for the most abundant isotopomers are B( 187Re) = 3466.964(2) MHz and B( 185Re) = 3467.049(3) MHz. The quadrupole coupling strengths are eQq( 187Re) = 716.55(2) MHz and eQq( 185Re) = 757.19(3) MHz. Transitions were also observed for 13C isotopomers and 18O isotopomers. The value for the ReC bond length obtained from a Kraitchman analysis is R( ReC) = 2.080 Å. The rhenium quadrupole coupling strengths are about 20% smaller than those obtained for HRe(CO) 5.

Mineral trioxide aggregate repair of a perforating internal resorption in a mandibular molar.

PubMed

Meire, Maarten; De Moor, Roeland

2008-02-01

Internal resorption is a rare condition in permanent teeth that poses difficulties for treatment. The challenge is complicated further if the resorption extends beyond the confines of the root. This article describes treatment of a perforating internal resorption in the mesial root of a second lower molar, with adjacent destruction of the alveolar bone. After cleaning the root canal space and the resorption lacuna by mechanical instrumentation, irrigation, and interim calcium hydroxide dressing, the defect was filled with mineral trioxide aggregate, and the canals were obturated conventionally with gutta percha and epoxy resin sealer. At a 2-year follow-up examination, no clinical abnormalities were found, and complete resolution of the alveolar bone lesion and establishment of a new periodontal ligament were observed.

Ethanol Reduced Molybdenum Trioxide for Li-ion Capacitors

DOE PAGES

Li, Tianqi; Beidaghi, Majid; Xiao, Xu; ...

2016-05-06

Orthorhombic molybdenum trioxide (α-MoO 3) is a layered oxide with promising performance as electrode material for Li-ion capacitors. In this study, we show that expansion of the interlayer spacing (by ~0.32 Å) of the structure along the b-axis, introduced by partial reduction of α-MoO 3 and formation of MoO 3-x (x=0.06–0.43), results in enhanced diffusion of Li ions. Binder-free hybrid electrodes made of MoO 3-x nanobelts and carbon nanotubes show excellent electrical conductivity. The combination of increased interlayer spacing and enhanced electron transport leads to high gravimetric and volumetric capacitances of about 420 F/g or F/cm 3 and excellent cyclemore » life of binder-free MoO 3-x electrodes.« less

Nanowire growth by an electron beam induced massive phase transformation

DOE PAGES

Sood, Shantanu; Kisslinger, Kim; Gouma, Perena

2014-11-15

Tungsten trioxide nanowires of a high aspect ratio have been synthesized in-situ in a TEM under an electron beam of current density 14A/cm² due to a massive polymorphic reaction. Sol-gel processed pseudocubic phase nanocrystals of tungsten trioxide were seen to rapidly transform to one dimensional monoclinic phase configurations, and this reaction was independent of the substrate on which the material was deposited. The mechanism of the self-catalyzed polymorphic transition and accompanying radical shape change is a typical characteristic of metastable to stable phase transformations in nanostructured polymorphic metal oxides. A heuristic model is used to confirm the metastable to stablemore » growth mechanism. The findings are important to the control electron beam deposition of nanowires for functional applications starting from colloidal precursors.« less

Light-Induced Surface Reactions at the Bismuth Vanadate/Potassium Phosphate Interface.

PubMed

Favaro, Marco; Abdi, Fatwa F; Lamers, Marlene; Crumlin, Ethan J; Liu, Zhi; van de Krol, Roel; Starr, David E

2018-01-18

Bismuth vanadate has recently drawn significant research attention as a light-absorbing photoanode due to its performance for photoelectrochemical water splitting. In this study, we use in situ ambient pressure X-ray photoelectron spectroscopy with "tender" X-rays (4.0 keV) to investigate a polycrystalline bismuth vanadate (BiVO 4 ) electrode in contact with an aqueous potassium phosphate (KPi) solution at open circuit potential under both dark and light conditions. This is facilitated by the creation of a 25 to 30 nm thick electrolyte layer using the "dip-and-pull" method. We observe that under illumination bismuth phosphate forms on the BiVO 4 surface leading to an increase of the surface negative charge. The bismuth phosphate layer may act to passivate surface states observed in photoelectrochemical measurements. The repulsive interaction between the negatively charged surface under illumination and the phosphate ions in solution causes a shift in the distribution of ions in the thin aqueous electrolyte film, which is observed as an increase in their photoelectron signals. Interestingly, we find that such changes at the BiVO 4 /KPi electrolyte interface are reversible upon returning to dark conditions. By measuring the oxygen 1s photoelectron peak intensities from the phosphate ions and liquid water as a function of time under dark and light conditions, we determine the time scales for the forward and reverse reactions. Our results provide direct evidence for light-induced chemical modification of the BiVO 4 /KPi electrolyte interface.

An evaluation of in-plane shields during thoracic CT.

PubMed

Foley, S J; McEntee, M F; Rainford, L A

2013-08-01

The object of this study was to compare organ dose and image quality effects of using bismuth and barium vinyl in-plane shields with standard and low tube current thoracic CT protocols. A RANDO phantom was scanned using a 64-slice CT scanner and three different thoracic protocols. Thermoluminescent dosemeters were positioned in six locations to record surface and absorbed breast and lung doses. Image quality was assessed quantitatively using region of interest measurements. Scanning was repeated using bismuth and barium vinyl in-plane shields to cover the breasts and the results were compared with standard and reduced dose protocols. Dose reductions were most evident in the breast, skin and anterior lung when shielding was used, with mean reductions of 34, 33 and 10 % for bismuth and 23, 18 and 11 % for barium, respectively. Bismuth was associated with significant increases in both noise and CT attenuation values for all the three protocols, especially anteriorly and centrally. Barium shielding had a reduced impact on image quality. Reducing the overall tube current reduced doses in all the locations by 20-27 % with similar increases in noise as shielding, without impacting on attenuation values. Reducing the overall tube current best optimises dose with minimal image quality impact. In-plane shields increase noise and attenuation values, while reducing anterior organ doses primarily. Shielding remains a useful optimisation tool in CT and barium is an effective alternative to bismuth especially when image quality is of concern.

Overcoming Limitations in Semiconductor Alloy Design

NASA Astrophysics Data System (ADS)

Christian, Theresa Marie

Inorganic semiconductors provide an astonishingly versatile, robust, and efficient platform for optoelectronic energy conversion devices. However, conventional alloys and growth regimes face materials challenges that restrict the full potential of these devices. Novel alloy designs based on isoelectronic co-doping, metamorphic growth and controllable atomic ordering offer new pathways to practical and ultra-high-efficiency optoelectronic devices including solar cells and light-emitting diodes. Abnormal isoelectronic alloys of GaP1-xBix, GaP 1-x-yBixNy, and GaAs1-xBix with unprecedented bismuth incorporation fractions and crystalline quality are explored in this thesis research. Comparative studies of several GaP1-xBix and GaP1-x-yBixNy alloys demonstrate that the site-specific incorporation of bismuth during epitaxial growth is sensitive to growth temperature and has dramatic effects on carrier transfer processes in these alloys. Additionally, distinctive bismuth-related localized states are spectrally identified for the first time in samples of GaAs1-xBix grown by laser-assisted epitaxial growth. These results address fundamental questions about the nature of bismuth-bismuth inter-impurity interactions. Finally, a metamorphic growth strategy for a novel light-emitting diode (LED) design is also discussed. This work utilized direct-bandgap AlxIn1-xP active layers with atomic ordering-based electron confinement to improve emission in the yellow and green spectral regions, where incumbent technologies are least effective, and demonstrated the feasibility of non-lattice-matched LED active materials for visible light emission.

Solubility and disintegration of new calcium aluminate cement (EndoBinder) containing different radiopacifying agents.

PubMed

Garcia, Lucas da Fonseca Roberti; Chinelatti, Michelle Alexandra; Rossetto, Hebert Luis; Pires-de-Souza, Fernanda de Carvalho Panzeri

2014-02-01

The aim of this study was to evaluate the solubility and disintegration of EndoBinder (EB) containing 3 different radiopacifying agents, bismuth oxide (Bi2O3), zinc oxide (ZnO), or zirconium oxide (ZrO2), in comparison with gray mineral trioxide aggregate (GMTA) and white MTA (WMTA). Ten specimens of each cement were made in a stainless steel matrix (20 × 1.5 mm) according to Specification no. 57 of American National Standards Institute/American Dental Association: EB + Bi2O3, EB + ZrO, EB + ZnO, WMTA, and GMTA. The specimens were weighed on an accurate analytical scale and immersed in 50 mL distilled and deionized water at 37°C for 7 days. Afterwards, specimens were dried and weighed again to determine mass loss (%). Resulting solutions were analyzed in an atomic absorption spectrophotometer for identification and quantification of chemical elements released. All cements presented mean values of solubility and disintegration above the American National Standards Institute/American Dental Association Specification no. 57. EB + Bi2O3 presented the lowest mass loss (5.08%) and WMTA (6.65%) the highest, with no statistically significant difference (P > .05). The release of several chemical elements was observed, mostly metal ions. Only GMTA and EB + Bi2O3 showed the presence of Cr, with significant difference (P < .05). EB + ZnO presented the highest levels of Pb, followed by WMTA (P < .05). For As, the cements presented different release levels, with EB + ZnO showing the highest and GMTA the lowest levels (P < .05). However, the amounts of As and Pb released were lower than the safe limit proposed by ISO 9917-1. Irrespective of the radiopacifying agents used, EndoBinder presented similar behavior to MTA. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Pharmacokinetics and bioequivalence of ranitidine and bismuth derived from two compound preparations

PubMed Central

Zhou, Quan; Ruan, Zou-Rong; Yuan, Hong; Jiang, Bo; Xu, Dong-Hang

2006-01-01

AIM: To evaluate the bioequivalence of ranitidine and bismuth derived from two compound preparations. METHODS: The bioavailability was measured in 20 healthy male Chinese volunteers following a single oral dose (equivalent to 200 mg of ranitidine and 220 mg of bismuth) of the test or reference products in the fasting state. Then blood samples were collected for 24 h. Plasma concentrations of ranitidine and bismuth were analyzed by high-performance liquid chromatography and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. The non-compartmental method was used for pharmacokinetic analysis. Log-transformed Cmax, AUC(0-t) and AUC(0-infinity) were tested for bioequivalence using ANOVA and Schuirmann two-one sided t-test. Tmax was analyzed by Wilcoxon’s test. RESULTS: Various pharmacokinetic parameters of ranitidine derived from the two compound preparations, including Cmax, AUC(0-t), AUC(0-infinity), Tmax and T1/2, were nearly consistent with previous observations. These parameters derived from test and reference drug were as follows: Cmax (0.67 ± 0.21 vs 0.68 ± 0.22 mg/L), AUC(0-t) (3.1 ± 0.6 vs 3.0 ± 0.7 mg/L per hour), AUC(0-infinity) (3.3 ± 0.6 vs 3.2 ± 0.8 mg/L per hour), Tmax (2.3 ± 0.9 vs 2.1 ± 0.9 h) and T1/2 (2.8 ± 0.3 vs 3.1 ± 0.4 h). In addition, double-peak absorption profiles of ranitidine were found in some Chinese volunteers. For bismuth, those parameters derived from test and reference drug were as follows: Cmax (11.80 ± 7.36 vs 11.40 ± 6.55 μg/L), AUC(0-t) (46.65 ± 16.97 vs 47.03 ± 21.49 μg/L per hour), Tmax (0.50 ± 0.20 vs 0.50 ± 0.20 h) and T1/2 (10.2 ± 2.3 vs 13.0 ± 6.9 h). Ninety percent of confidence intervals for the test/reference ratio of Cmax, AUC(0-t) and AUC(0-infinity) derived from both ranitidine and bismuth were found within the bioequivalence acceptable range of 80%-125%. No significant difference was found in Tmax derived from both ranitidine and bismuth. CONCLUSION: The two compound preparations are bioequivalent and may be prescribed interchangeably. PMID:16718762

Investigation of crystal growth in zero gravity environment and investigation of metallic whiskers

NASA Technical Reports Server (NTRS)

Davis, J. H.; Lal, R. B.; Walter, H. U.; Castle, J. G., Jr.

1972-01-01

Theoretical and experimental work reported relates to the effects of near-zero gravity on growths of crystals and metallic whiskers during Skylab and Apollo flight experiments. Studies on growth and characterization of candidate materials for flight experiments cover indium-bismuth compounds, bismuth single crystals, gallium arsenide films and single crystals, and cadmium whiskers.

Mixed-layered bismuth--oxygen--iodine materials for capture and waste disposal of radioactive iodine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krumhansl, James L; Nenoff, Tina M

2015-01-06

Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility inmore » groundwater environments.« less

Bismuth Titanate Fabricated by Spray-on Deposition and Microwave Sintering For High-Temperature Ultrasonic Transducers.

PubMed

Searfass, Clifford T; Pheil, C; Sinding, K; Tittmann, B R; Baba, A; Agrawal, D K

2016-01-01

Thick films of ferroelectric bismuth titanate (Bi4Ti3O12) have been fabricated by spray-on deposition in conjunction with microwave sintering for use as high-temperature ultrasonic transducers. The elastic modulus, density, permittivity, and conductivity of the films were characterized. Electro-mechanical properties of the films were estimated with a commercial d33 meter which gave 16 pC/N. This value is higher than typically reported for bulk bismuth titanate; however, these films withstand higher field strengths during poling which is correlated with higher d33 values. Films were capable of operating at 650 °C for roughly 5 min before depoling and can operate at 600 °C for at least 7 days.

Effect of Immersion Time on Corrosion Behavior of Single-Phase Alloy and Nanocomposite Bismuth Telluride-Based Thermoelectrics in NaCl Solution

NASA Astrophysics Data System (ADS)

Keshavarz, Mohsen K.; Fattah-Alhosseini, Arash

2018-05-01

The corrosiveness of bismuth telluride-based thermoelectric materials (n-type single-phase alloy and a nanocomposite with MoS2 nanoinclusions), in 0.1 molar solution of sodium chloride (NaCl), was investigated. The electrochemical impedance spectroscopy curves obtained after 1, 24, 48 and 72 h immersion time revealed the enhancement of the corrosion resistance of the nanocomposite specimen in a 0.1 molar NaCl solution in comparison with the single-phase bismuth telluride-based alloys, and the passivity increased by immersion time up to 72 h. The nanocomposite sample with submicron grains provided suitable nucleation sites for passive film nucleation that led to higher protective behavior.

Fast oxygen diffusion in bismuth oxide probed by quasielastic neutron scattering

DOE PAGES

Mamontov, Eugene

2016-09-24

In this paper, we present the first, to our knowledge, study of solid state oxygen translational diffusion by quasielastic neutron scattering. Such studies in the past might have been precluded by relatively low diffusivities of oxygen anions in the temperature range amenable to neutron scattering experiments. To explore the potential of the quasielastic scattering technique, which can deduce atomic diffusion jump length of oxygen anions through the momentum transfer dependence of the scattering signal, we have selected the fastest known oxygen conductor, bismuth oxide. Finally, we have found the oxygen anion jump length in excellent agreement with the nearest oxygen-vacancymore » distance in the anion sublattice of the fluorite-related structure of bismuth oxide.« less

Study of iron structure stability in high temperature molten lead-bismuth eutectic with oxygen injection using molecular dynamics simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arkundato, Artoto; Su'ud, Zaki; Sudarko

2014-09-30

Corrosion of structural materials in high temperature molten lead-bismuth eutectic is a major problem for design of PbBi cooled reactor. One technique to inhibit corrosion process is to inject oxygen into coolant. In this paper we study and focus on a way of inhibiting the corrosion of iron using molecular dynamics method. For the simulation results we concluded that effective corrosion inhibition of iron may be achieved by injection 0.0532 wt% to 0.1156 wt% oxygen into liquid lead-bismuth. At this oxygen concentration the structure of iron material will be maintained at about 70% in bcc crystal structure during interaction withmore » liquid metal.« less

21 CFR 184.1095 - Sulfuric acid.

Code of Federal Regulations, 2011 CFR

2011-04-01

... CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific... (SO2) with oxygen and mixing the resultant sulfur trioxide (SO3) with water, or by reacting nitric...

21 CFR 184.1095 - Sulfuric acid.

Code of Federal Regulations, 2013 CFR

2013-04-01

... CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific... (SO2) with oxygen and mixing the resultant sulfur trioxide (SO3) with water, or by reacting nitric...

Enhancement of efficiencies for tandem green phosphorescent organic light-emitting devices with a p-type charge generation layer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoo, Byung Soo; Jeon, Young Pyo; Lee, Dae Uk

2014-10-15

The operating voltage of the tandem green phosphorescent organic light-emitting device with a 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile layer was improved by 3% over that of the organic light-emitting device with a molybdenum trioxide layer. The maximum brightness of the tandem green phosphorescent organic light-emitting device at 21.9 V was 26,540 cd/m{sup 2}. The dominant peak of the electroluminescence spectra for the devices was related to the fac-tris(2-phenylpyridine) iridium emission. - Highlights: • Tandem OLEDs with CGL were fabricated to enhance their efficiency. • The operating voltage of the tandem OLED with a HAT-CN layer was improved by 3%. • The efficiency and brightnessmore » of the tandem OLED were 13.9 cd/A and 26,540 cd/m{sup 2}. • Efficiency of the OLED with a HAT-CN layer was lower than that with a MoO{sub 3} layer. - Abstract: Tandem green phosphorescent organic light-emitting devices with a 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile or a molybdenum trioxide charge generation layer were fabricated to enhance their efficiency. Current density–voltage curves showed that the operating voltage of the tandem green phosphorescent organic light-emitting device with a 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile layer was improved by 3% over that of the corresponding organic light-emitting device with a molybdenum trioxide layer. The efficiency and the brightness of the tandem green phosphorescent organic light-emitting device were 13.9 cd/A and 26,540 cd/m{sup 2}, respectively. The current efficiency of the tandem green phosphorescent organic light-emitting device with a 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile layer was lower by 1.1 times compared to that of the corresponding organic light-emitting device with molybdenum trioxide layer due to the decreased charge generation and transport in the 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile layer resulting from triplet–triplet exciton annihilation.« less

Dominance of Plasmonic Resonant Energy Transfer over Direct Electron Transfer in Substantially Enhanced Water Oxidation Activity of BiVO4 by Shape-Controlled Au Nanoparticles.

PubMed

Lee, Mi Gyoung; Moon, Cheon Woo; Park, Hoonkee; Sohn, Woonbae; Kang, Sung Bum; Lee, Sanghan; Choi, Kyoung Jin; Jang, Ho Won

2017-10-01

The performance of plasmonic Au nanostructure/metal oxide heterointerface shows great promise in enhancing photoactivity, due to its ability to confine light to the small volume inside the semiconductor and modify the interfacial electronic band structure. While the shape control of Au nanoparticles (NPs) is crucial for moderate bandgap semiconductors, because plasmonic resonance by interband excitations overlaps above the absorption edge of semiconductors, its critical role in water splitting is still not fully understood. Here, first, the plasmonic effects of shape-controlled Au NPs on bismuth vanadate (BiVO 4 ) are studied, and a largely enhanced photoactivity of BiVO 4 is reported by introducing the octahedral Au NPs. The octahedral Au NP/BiVO 4 achieves 2.4 mA cm -2 at the 1.23 V versus reversible hydrogen electrode, which is the threefold enhancement compared to BiVO 4 . It is the highest value among the previously reported plasmonic Au NPs/BiVO 4 . Improved photoactivity is attributed to the localized surface plasmon resonance; direct electron transfer (DET), plasmonic resonant energy transfer (PRET). The PRET can be stressed over DET when considering the moderate bandgap semiconductor. Enhanced water oxidation induced by the shape-controlled Au NPs is applicable to moderate semiconductors, and shows a systematic study to explore new efficient plasmonic solar water splitting cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bismuth Infusion of ABS Enables Additive Manufacturing of Complex Radiological Phantoms and Shielding Equipment.

PubMed

Ceh, Justin; Youd, Tom; Mastrovich, Zach; Peterson, Cody; Khan, Sarah; Sasser, Todd A; Sander, Ian M; Doney, Justin; Turner, Clark; Leevy, W Matthew

2017-02-24

Radiopacity is a critical property of materials that are used for a range of radiological applications, including the development of phantom devices that emulate the radiodensity of native tissues and the production of protective equipment for personnel handling radioactive materials. Three-dimensional (3D) printing is a fabrication platform that is well suited to creating complex anatomical replicas or custom labware to accomplish these radiological purposes. We created and tested multiple ABS (Acrylonitrile butadiene styrene) filaments infused with varied concentrations of bismuth (1.2-2.7 g/cm³), a radiopaque metal that is compatible with plastic infusion, to address the poor gamma radiation attenuation of many mainstream 3D printing materials. X-ray computed tomography (CT) experiments of these filaments indicated that a density of 1.2 g/cm³ of bismuth-infused ABS emulates bone radiopacity during X-ray CT imaging on preclinical and clinical scanners. ABS-bismuth filaments along with ABS were 3D printed to create an embedded human nasocranial anatomical phantom that mimicked radiological properties of native bone and soft tissue. Increasing the bismuth content in the filaments to 2.7 g/cm³ created a stable material that could attenuate 50% of 99m Technetium gamma emission when printed with a 2.0 mm wall thickness. A shielded test tube rack was printed to attenuate source radiation as a protective measure for lab personnel. We demonstrated the utility of novel filaments to serve multiple radiological purposes, including the creation of anthropomorphic phantoms and safety labware, by tuning the level of radiation attenuation through material customization.

[The high fermentative capacity of colonic bacteria in the origin of flatulence and its sensibility to bismuth subsalicylate].

PubMed

León-Barúa, Raúl; Alvarez De Roig, Maritza; Roig-Arosemena, Javier; Berendson-Seminario, Roberto; Torres-Zevallos, Hernando

2007-01-01

Using a previously described technique, "in vitro" determinations were carried out for faecal fermentation (FF): basal faecal fermentation (BFF), i.e, only with faeces, with faeces and lactulose (LFF) and with faeces, lactulose and bismuth subsalicylate (BiLFF) in 34 patients with flatulence. The media+d.s. of the difference between the LFFand BFF levels (LFF-BFF) in patients with flatulence was significant and markedly higher than the respective media +d.s. in 30 normal control patients previously studied (9.1+4.7 vs. 3.9+3.2 ml gas/24 hrs; p<0.000001 respectively). And, although FF was reduced by adding bismuth salicylate in only 24% (70.6%) of the patients with flatulence but not in the remaining 10 (29.4%), in total the media+d.s. of the differences between the levels BiLFF and BFF (BiLFFBFF) was significantly lower that the media+d.s. of the differences between the LFF and BFF levels (LFF-BFF) (6.0+4.2 vs 9.1+4.7 ml gas/24 hrs; p<0.01 respectively). These results confirm that: 1) The fermentative capacity of the colonic bacteriae is most likely to be abnormally intense in peoples with flatulence and 2) Bismuth subsalicylate can be useful in the control of excessive colonic fermentation and flatulence; they raise, furthermore, the interesting possibility that we may have found the way to predict when the use of bismuth subsalicylate could be effective in the treatment of a patient with flatulence.

Modulation of magnetic interaction in Bismuth ferrite through strain and spin cycloid engineering

NASA Astrophysics Data System (ADS)

Yadav, Rama Shanker; Reshi, Hilal Ahmad; Pillai, Shreeja; Rana, D. S.; Shelke, Vilas

2016-12-01

Bismuth ferrite, a widely studied room temperature multiferroic, provides new horizons of multifunctional behavior in phase transited bulk and thin film forms. Bismuth ferrite thin films were deposited on lattice mismatched LaAlO3 substrate using pulsed laser deposition technique. X-ray diffraction confirmed nearly tetragonal (T-type) phase of thin film involving role of substrate induced strain. The film thickness of 56 nm was determined by X-ray reflectivity measurement. The perfect coherence and epitaxial nature of T- type film was observed through reciprocal space mapping. The room temperature Raman measurement of T-type bismuth ferrite thin film also verified phase transition with appearance of only few modes. In parallel, concomitant La and Al substituted Bi1-xLaxFe0.95Al0.05O3 (x = 0.1, 0.2, 0.3) bulk samples were synthesized using solid state reaction method. A structural phase transition into orthorhombic (Pnma) phase at x = 0.3 was observed. The structural distortion at x = 0.1, 0.2 and phase transition at x = 0.3 substituted samples were also confirmed by changes in Raman active modes. The remnant magnetization moment of 0.199 emu/gm and 0.28 emu/gm were observed for x = 0.2 and 0.3 bulk sample respectively. The T-type bismuth ferrite thin film also showed high remnant magnetization of around 20emu/cc. The parallelism in magnetic behavior between T-type thin film and concomitant La and Al substituted bulk samples is indication of modulation, frustration and break in continuity of spiral spin cycloid.

Mineral trioxide aggregate as pulp dressing agent in pulpotomy treatment of primary molars: 42-month clinical study.

PubMed

Maroto, Myriam; Barbería, Elena; Vera, Vicente; García-Godoy, Franklin

2007-10-01

To evaluate the long-term clinical and radiographical results of using gray mineral trioxide aggregate (MTA) in pulpotomy treatments in primary molars. A total of 69 primary molars were treated with pulpotomy procedures using MTA and follow-up every 6 months up to 42 months. Clinical success was 100% as none of the molars showed clinical pathologic signs; radiographical success was 98.5% as one case of internal resorption was recorded. Reparative dentin deposition was found as stenosis of the pulp canals in 84% of the cases 42 months after treatment and as dentin bridge formation in 83% of the cases 42 months after treatment. Moreover, 11 permanent successors erupted at their normal exfoliation time without pathology after pulpotomy treatment with gray MTA of the primary molars.

Comparison of clinical outcomes of patients with relapsed acute promyelocytic leukemia induced with arsenic trioxide and consolidated with either an autologous stem cell transplant or an arsenic trioxide-based regimen.

PubMed

Thirugnanam, Rajasekar; George, Biju; Chendamarai, Ezhil; Lakshmi, Kavitha M; Balasubramanian, Poonkuzhali; Viswabandya, Auro; Srivastava, Alok; Chandy, Mammen; Mathews, Vikram

2009-11-01

In patients with relapsed acute promyelocytic leukemia (APL), the best consolidation regimen following induction of remission with arsenic trioxide (ATO) remains to be defined. Since January 2000, 37 patients with relapsed APL were treated at our center. The median age was 34 years (range, 6-57 years), and there were 20 males (54.1%). The median duration of first remission was 20.3 months (range, 2.9-81.2 months). Relapse was treated with single-agent ATO in 22 patients (59.5%), ATO+ATRA in 5 patients (13.5%), and ATO+ATRA + anthracycline in 10 patients (27%). Thirty-three patients (89%) achieved molecular remission after induction and a consolidation course. Fourteen patients opted to undergo autologous stem cell transplantation (SCT), and the remaining 19 patients received monthly cycles of ATO as a single agent (n=13) or ATO+ATRA (n=6) for 6 months. At a median follow-up of 32 months, the 5-year Kaplan-Meier estimate of event-free survival (EFS) was 83.33% +/- 15.21% in those who underwent autologous SCT versus 34.45% +/- 11.24% in those who did not (P=.001; log-rank test). Following remission induction with ATO-based regimens in patients with relapsed APL, consolidation with autologous SCT is associated with a significantly superior clinical outcome compared with ATO- and ATO+ATRA-based maintenance regimens.

Chemistry and Mechanism of Interaction Between Molybdenite Concentrate and Sodium Chloride When Heated in the Presence of Oxygen

NASA Astrophysics Data System (ADS)

Aleksandrov, P. V.; Medvedev, A. S.; Imideev, V. A.; Moskovskikh, D. O.

2017-04-01

Roasting of molybdenum concentrates with sodium chloride has high potential and can be an alternative to oxidizing roasting and autoclave leaching; however, the chemistry and mechanism are poorly known. The chemical mechanism of the roasting process between molybdenite concentrate and sodium chloride in the presence of atmospheric oxygen is proposed. It is demonstrated that the process occurs through molybdenite oxidation, up to molybdenum trioxide, with subsequent formation of sodium polymolybdates and molybdenum dioxydichloride from molybdenum trioxide. It is found that the formation of water-soluble sodium polymolybdates from molybdenum trioxide stops over time due to passivation of sodium chloride surface by polymolybdates. It is proved experimentally that preliminary grinding of the mixture in a furnace charge leads to an increase in the polymolybdate fraction of the roasting products, which constitutes approximately 65 pct of molybdenum initially in the roasted mixture against 20 to 22 pct in a nonground mixture (or 75 to 77 pct against 30 to 33 pct of molybdenum in calcine). For the first time, the presence of the Na2S2O7 phase in the calcine was confirmed experimentally. The suggested mechanism gives possible explanations for the sharp increase of MoO2Cl2 formation within the temperature range of 673 K to 723 K (400 °C to 450 °C) that is based on the catalytic reaction of molybdenum dioxydichloride from the Na2S2O7 liquid phase as it runs in a melt.

A potentized homeopathic drug, Arsenicum Album 200, can ameliorate genotoxicity induced by repeated injections of arsenic trioxide in mice.

PubMed

Banerjee, P; Biswas, S J; Belon, P; Khuda-Bukhsh, A R

2007-09-01

Groundwater arsenic contamination has become a menacing global problem. No drug is available until now to combat chronic arsenic poisoning. To examine if a potentized homeopathic remedy, Arsenicum Album-200, can effectively combat chronic arsenic toxicity induced by repeated injections of Arsenic trioxide in mice, the following experimental design was adopted. Mice (Mus musculus) were injected subcutaneously with 0.016% arsenic trioxide at the rate of 1 ml/100 g body weight, at an interval of 7 days until they were killed at day 30, 60, 90 or 120 and were divided into three groups: (i) one receiving a daily dose of Arsenicum Album-200 through oral administration, (ii) one receiving the same dose of diluted succussed alcohol (Alcohol-200) and (iii) another receiving neither drug, nor succussed alcohol. The remedy or the placebo, as the case may be, was fed from the next day onwards after injection until the day before the next injection, and the cycle was repeated until the mice were killed. Two other control groups were also maintained: one receiving only normal diet, and the other receiving normal diet and succussed alcohol. Several toxicity assays, such as cytogenetical (chromosome aberrations, micronuclei, mitotic index, sperm head anomaly) and biochemical (acid and alkaline phosphatases, lipid peroxidation), were periodically made. Compared with controls, the drug fed mice showed reduced toxicity at statistically significant levels in respect of all the parameters studied, thereby indicating protective potentials of the homeopathic drug against chronic arsenic poisoning.

"Chemical contraction" in rubidium-bismuth melts

NASA Astrophysics Data System (ADS)

Khairulin, R. A.; Abdullaev, R. N.; Stankus, S. V.

2017-10-01

The density and thermal expansion of liquid rubidium and rubidium-bismuth alloy containing 25.0 at % Bi were measured by the gamma-ray attenuation technique at temperatures from liquidus to 1000 K. The results of this study were compared with the data obtained by other authors. The molar volume of the Rb75Bi25 melt strongly deviates from the additivity rule for ideal solutions.

THORIUM DISPERSION IN BISMUTH

DOEpatents

Bryner, J.S.

1961-07-01

The growth of thorium bismutaide particles, which are formed when thorium is suspended in liquid bismuth, is inhibited when the liquid metal suspension is being flowed through a reactor and through a heat exchanger in sequence. It involves the addition of as little as 1 part by weight of tellurium to 100 parts of thorium. This addition is sufficient to inhibit particle growth and agglomeration.

Silver Ink For Jet Printing

NASA Technical Reports Server (NTRS)

Vest, R. W.; Singaram, Saraswathi

1989-01-01

Metallo-organic ink containing silver (with some bismuth as adhesion agent) applied to printed-circuit boards and pyrolized in air to form electrically conductive patterns. Ink contains no particles of silver, does not have to be mixed during use to maintain homogeneity, and applied to boards by ink-jet printing heads. Consists of silver neodecanoate and bismuth 2-ethylhexanoate dissolved in xylene and/or toluene.

Strongly Enhanced Photovoltaic Performance and Defect Physics of Air-Stable Bismuth Oxyiodide (BiOI)

DOE PAGES

Hoye, Robert L. Z.; Lee, Lana C.; Kurchin, Rachel C.; ...

2017-07-17

Bismuth-based compounds have recently gained increasing attention as potentially nontoxic and defect-tolerant solar absorbers. However, many of the new materials recently investigated show limited photovoltaic performance. Herein, one such compound is explored in detail through theory and experiment: bismuth oxyiodide (BiOI). BiOI thin films are grown by chemical vapor transport and found to maintain the same tetragonal phase in ambient air for at least 197 d. The computations suggest BiOI to be tolerant to antisite and vacancy defects. All-inorganic solar cells (ITO|NiO x|BiOI|ZnO|Al) with negligible hysteresis and up to 80% external quantum efficiency under select monochromatic excitation are demonstrated. Themore » short-circuit current densities and power conversion efficiencies under AM 1.5G illumination are nearly double those of previously reported BiOI solar cells, as well as other bismuth halide and chalcohalide photovoltaics recently explored by many groups. Through a detailed loss analysis using optical characterization, photoemission spectroscopy, and device modeling, direction for future improvements in efficiency is provided. In conclusion, this work demonstrates that BiOI, previously considered to be a poor photocatalyst, is promising for photovoltaics.« less

Explanation of the conductivity minimum in tin- and tellurium-doped bismuth

NASA Astrophysics Data System (ADS)

Roy, Arpita; Banerjee, Dipali; Bhattacharya, Ramendranarayan

1995-01-01

The presence of a minimum observed in the variation of conductivity of bismuth with impurity concentrations at a constant temperature (4.2 K) has remained unexplained for a long time. An attempt to explain this anomalous behavior is reported here. In order to do so, a calculation has been made to find the change in the number of free carriers in bismuth with the addition of impurities (donors or acceptors). The calculation has been made using simple parabolic bands. It is known that when tin or tellurium atoms are added as impurities to bismuth all of the atoms are ionized. It has been found here that the number of free carriers initially shows a slow rate of decrease (for donors) or a slow rate of increase (for acceptors) as the impurity concentration is increased, as long as the impurity concentration is small, i.e., as long as the shift of the Fermi level is small. For a higher impurity concentration the number of carriers increases at a rate equal to that of the impurity concentration. This finding, combined with the scattering by impurity ions, could explain the anomalous behavior satisfactorily.

Soluble Lead and Bismuth Chalcogenidometallates: Versatile Solders for Thermoelectric Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Hao; Son, Jae Sung; Dolzhnikov, Dmitriy S.

Here we report the syntheses of largely unexplored lead and bismuth chalcogenidometallates in the solution phase. Using N2H4 as the solvent, new compounds such as K6Pb3Te6·7N2H4 were obtained. These soluble molecular compounds underwent cation exchange processes using resin chemistry, replacing Na+ or K+ by decomposable N2H5+ or tetraethylammonium cations. They also transformed into stoichiometric lead and bismuth chalcogenide nanomaterials with the addition of metal salts. Such a versatile chemistry led to a variety of composition-matched solders to join lead and bismuth chalcogenides and tune their charge transport properties at the grain boundaries. Solution-processed thin films composed of Bi0.5Sb1.5Te3 microparticles solderedmore » by (N2H5)6Bi0.5Sb1.5Te6 exhibited thermoelectric power factors (~28 μW/cm K2) comparable to those in vacuum-deposited Bi0.5Sb1.5Te3 films. The soldering effect can also be integrated with attractive fabrication techniques for thermoelectric modules, such as screen printing, suggesting the potential of these solders in the rational design of printable and moldable thermoelectrics.« less

Tin, Bismuth, and Tin-Bismuth Alloy Electrodeposition from Chlorometalate Salts in Deep Eutectic Solvents.

PubMed

Vieira, Luciana; Burt, Jennifer; Richardson, Peter W; Schloffer, Daniel; Fuchs, David; Moser, Alwin; Bartlett, Philip N; Reid, Gillian; Gollas, Bernhard

2017-06-01

The electrodeposition of tin, bismuth, and tin-bismuth alloys from Sn II and Bi III chlorometalate salts in the choline chloride/ethylene glycol (1:2 molar ratio) deep eutectic solvent was studied on glassy carbon and gold by cyclic voltammetry, rotating disc voltammetry, and chronoamperometry. The Sn II -containing electrolyte showed one voltammetric redox process corresponding to Sn II /Sn 0 . The diffusion coefficient of [SnCl 3 ] - , detected as the dominating species by Raman spectroscopy, was determined from Levich and Cottrell analyses. The Bi III -containing electrolyte showed two voltammetric reduction processes, both attributed to Bi III /Bi 0 . Dimensionless current/time transients revealed that the electrodeposition of both Sn and Bi on glassy carbon proceeded by 3D-progressive nucleation at a low overpotential and changed to instantaneous at higher overpotentials. The nucleation rate of Bi on glassy carbon was considerably smaller than that of Sn. Elemental Sn and Bi were electrodeposited on Au-coated glass slides from their respective salt solutions, as were Sn-Bi alloys from a 2:1 Sn II /Bi III solution. The biphasic Sn-Bi alloys changed from a Bi-rich composition to a Sn-rich composition by making the deposition potential more negative.

Theoretical study of bismuth-doped cadmium telluride

NASA Astrophysics Data System (ADS)

Menendez-Proupin, E.; Rios-Gonzalez, J. A.; Pena, J. L.

Cadmium telluride heavily doped with bismuth has been proposed as an absorber with an intermediate band for solar cells. Increase in the photocurrent has been shown recently, although the overall cell efficiency has not improved. In this work, we study the electronic structure and the formation energies of the defects associated to bismuth impurities. We have performed electronic structure calculations within generalized density functional theory, using the exchange-correlation functional HSE(w) , where the range-separation parameter w has been tuned to reproduce the CdTe bandgap. Improving upon previous reports, we have included the spin-orbit interaction, which modifies the structure of the valence band and the energy levels of bismuth. We have found that interstitial Bi (Bii) tends to occupy Cd vacancies, cadmium substitution (BiCd) creates single donor level, while tellurium substitution (BiTe) is a shallow single acceptor. We investigate the interaction between these point defects and how can they be combined to create a partially filled intermediate band. Supported by FONDECYT Grant 1130437, CONACYT-SENER SUSTENTABILIDAD ENERGETICA/project CeMIE-Sol PY-207450/25 and PY-207450/26. JARG acknowledges CONACYT fellowship for research visit. Powered@NLHPC (ECM-02).

Glass composite waste forms for iodine confined in bismuth-embedded SBA-15

NASA Astrophysics Data System (ADS)

Yang, Jae Hwan; Park, Hwan Seo; Ahn, Do-Hee; Yim, Man-Sung

2016-11-01

The aim of this study was to stabilize bismuth-embedded SBA-15 that captured iodine gas by fabrication of monolithic waste forms. The iodine containing waste was mixed with Bi2O3 (a stabilizing additive) and low-temperature sintering glass followed by pelletizing and the sintering process to produce glass composite materials. Iodine volatility during the sintering process was significantly affected by the ratio of Bi2O3 and the glass composition. It was confirmed that BiI3, the main iodine phase within bismuth-embedded SBA-15, was effectively transformed to the mixed phases of Bi5O7I and BiOI. The initial leaching rates of iodine from the glass composite waste forms ranged 10-3-10-2 g/m2 day, showing the stability of the iodine phases encapsulated by the glassy networks. It was also observed that common groundwater anions (e.g., chloride, carbonate, sulfite, and fluoride) elevated the iodine leaching rate by anion exchange reactions. The present results suggest that the glass composite waste form of bismuth-embedded SBA-15 could be a candidate material for stable storage of 129I.

Bismuth molybdate thick films as ethanol sensor

NASA Astrophysics Data System (ADS)

Jain, Kiran; Kumar, Vipin; Gupta, H. P.; Rastogi, A. C.

2003-10-01

Ethanol sensitivity of bismuth molybdate thick films and sintered pellets were investigated. Sintered pellets were prepared by traditional ceramic processing. Thick films were prepared by metallorganic decomposition process. Ethanol gas sensitivity was measured at various temperatures and concentrations. Thick films of alpha phase bismuth molybdate prepared by spray pyrolysis showed a very fast response to ethanol detection. The response time for the bulk samples is about 40 sec which decreased to about 6 sec for thick films at an operating temperature of 300°C. An extremely low level approximately 10 ppm detection and fast response makes this technique ideal for sensor element fabrication for detection and estimation of alcohol in breath-analyzer. Unlike SnO2, the resistance of these sensors is not affected by humidity at the operating temperature.

Role of Bismuth in the Electrokinetics of Silicon Photocathodes for Solar Rechargeable Vanadium Redox Flow Batteries.

PubMed

Flox, Cristina; Murcia-López, Sebastián; Carretero, Nina M; Ros, Carles; Morante, Juan R; Andreu, Teresa

2018-01-10

The ability of crystalline silicon to photoassist the V 3+ /V 2+ cathodic reaction under simulated solar irradiation, combined with the effect of bismuth have led to important electrochemical improvements. Besides the photovoltage supplied by the photovoltaics, additional decrease in the onset potentials, high reversibility of the V 3+ /V 2+ redox pair, and improvement in the electrokinetics were attained thanks to the addition of bismuth. In fact, Bi 0 deposition has shown to slightly decrease the photocurrent, but the significant enhancement in the charge transfer, reflected in the overall electrochemical performance clearly justifies its use as additive in a photoassisted system for maximizing the efficiency of solar charge to battery. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.