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Sample records for bacterial ferric ion

  1. Niobium Uptake and Release by Bacterial Ferric Ion Binding Protein

    Directory of Open Access Journals (Sweden)

    Yanbo Shi

    2010-01-01

    Full Text Available Ferric ion binding proteins (Fbps transport FeIII across the periplasm and are vital for the virulence of many Gram negative bacteria. Iron(III is tightly bound in a hinged binding cleft with octahedral coordination geometry involving binding to protein side chains (including tyrosinate residues together with a synergistic anion such as phosphate. Niobium compounds are of interest for their potential biological activity, which has been little explored. We have studied the binding of cyclopentadienyl and nitrilotriacetato NbV complexes to the Fbp from Neisseria gonorrhoeae by UV-vis spectroscopy, chromatography, ICP-OES, mass spectrometry, and Nb K-edge X-ray absorption spectroscopy. These data suggest that NbV binds strongly to Fbp and that a dinuclear NbV centre can be readily accommodated in the interdomain binding cleft. The possibility of designing niobium-based antibiotics which block iron uptake by pathogenic bacteria is discussed.

  2. Biopolymer-based nanosystem for ferric ion removal from water

    OpenAIRE

    Bodnár Magdolna; Hajdu István (1981-) (vegyész); Rőthi Eszter; Harmati Nóra; Csikós Zsuzsanna; Hartmann, John F.; Balogh Csaba; Kelemen Béla; Tamás János (1959-) (környezetgazdálkodási agrármérnök); Borbély János (1950-) (vegyész)

    2013-01-01

    The removal of ferric ions from aqueous solutions by a nanoparticle-enhanced ultrafiltration techniquewas investigated. Biodegradable poly-gamma-glutamic acid (c-PGA), a linear biopolymer, and itscross-linked nanoparticles were used to complex the metal ions by forming nanosized spherical particleswith more or less deformability. These polymer?metal ion particles were then removed by membraneseparation. Two ultrafiltration techniques were studied with the aim of developing a nanoparticleenhan...

  3. Spectroscopy of Ferric Heme and Protoporphyrin IX Ions In Vacuo

    DEFF Research Database (Denmark)

    Wyer, Jean; Nielsen, Steen Brøndsted

    2013-01-01

    This chapter deals with gas-phase spectroscopy of protoporphyrin IX and heme ions, two important biochromophores in nature. These ions strongly absorb blue and green light, which accounts for e.g. the red colour of blood. We present absorption spectra of four-coordinate ferric heme cations at room...... conversion to the ground state. This is somewhat supported by spectroscopic characterisation of the long-lived states based on pump-probe experiments. Hence from one time spectrum (a one-laser experiment), triplet quantum yields can easily be estimated....

  4. Ferric ion mediated photochemical decomposition of perfluorooctanoic acid (PFOA) by 254 nm UV light

    International Nuclear Information System (INIS)

    The great enhancement of ferric ion on the photochemical decomposition of environmentally persistent perfluorooctanoic acid (PFOA) under 254 nm UV light was reported. In the presence of 10 μM ferric ion, 47.3% of initial PFOA (48 μM) was decomposed and the defluorination ratio reached 15.4% within 4 h reaction time. While the degradation and defluorination ratio greatly increased to 80.2% and 47.8%, respectively, when ferric ion concentration increased to 80 μM, and the corresponding half-life was shortened to 103 min. Though the decomposition rate was significantly lowered under nitrogen atmosphere, PFOA was efficiently decomposed too. Other metal ions like Cu2+ and Zn2+ also slightly improved the photochemical decomposition of PFOA under irradiation of 254 nm UV light. Besides fluoride ion, other intermediates during PFOA decomposition including formic acid and five shorter-chain perfluorinated carboxylic acids (PFCAs) with C7, C6, C5, C4 and C3, respectively, were identified and quantified by IC or LC/MS. The mixture of PFOA and ferric ion had strong absorption around 280 nm. It is proposed that PFOA coordinates with ferric ion to form a complex, and its excitation by 254 nm UV light leads to the decomposition of PFOA in a stepwise way

  5. Mechanistic insights into metal ion activation and operator recognition by the ferric uptake regulator

    Science.gov (United States)

    Deng, Zengqin; Wang, Qing; Liu, Zhao; Zhang, Manfeng; Machado, Ana Carolina Dantas; Chiu, Tsu-Pei; Feng, Chong; Zhang, Qi; Yu, Lin; Qi, Lei; Zheng, Jiangge; Wang, Xu; Huo, Xinmei; Qi, Xiaoxuan; Li, Xiaorong; Wu, Wei; Rohs, Remo; Li, Ying; Chen, Zhongzhou

    2015-07-01

    Ferric uptake regulator (Fur) plays a key role in the iron homeostasis of prokaryotes, such as bacterial pathogens, but the molecular mechanisms and structural basis of Fur-DNA binding remain incompletely understood. Here, we report high-resolution structures of Magnetospirillum gryphiswaldense MSR-1 Fur in four different states: apo-Fur, holo-Fur, the Fur-feoAB1 operator complex and the Fur-Pseudomonas aeruginosa Fur box complex. Apo-Fur is a transition metal ion-independent dimer whose binding induces profound conformational changes and confers DNA-binding ability. Structural characterization, mutagenesis, biochemistry and in vivo data reveal that Fur recognizes DNA by using a combination of base readout through direct contacts in the major groove and shape readout through recognition of the minor-groove electrostatic potential by lysine. The resulting conformational plasticity enables Fur binding to diverse substrates. Our results provide insights into metal ion activation and substrate recognition by Fur that suggest pathways to engineer magnetotactic bacteria and antipathogenic drugs.

  6. Effect of ferric and bromide ions on the formation and speciation of disinfection byproducts during chlorination

    Institute of Scientific and Technical Information of China (English)

    Shaogang Liu; Zhiliang Zhu; Yanling Qiu; Jianfu Zhao

    2011-01-01

    The effects of ferric ion, pH, and bromide on the formation and distribution of disinfection byproducts (DBPs) during chlorination were studied. Two raw water samples from Huangpu River and Yangtze River, two typical drinking water sources of Shanghai, were used for the investigation. Compared with the samples from Huangpu River, the raw water samples from Yangtze River had lower content of total organic carbon (TOC) and ferric ions, but higher bromide concentrations. Under controlled chlorination conditions,four trihalomethanes (THMs), nine haloacetic acids (HAAs), total organic halogen (TOX) and its halogen species fractions, including total organic chlorine (TOC1) and total organic bromide (TOBr), were determined. The results showed that co-existent ferric and bromide ions significantly promoted the formation of total THMs and HAAs for both raw water samples. Higher concentration of bromide ions significantly changed the speciation of the formed THMs and HAAs. There was an obvious shift to brominated species,which might result in a more adverse influence on the safety of drinking water. The results also indicated that high levels of bromide ions in raw water samples produced higher percentages of unknown TOBr.

  7. Enhanced electrochemical oxidation of phenol by introducing ferric ions and UV radiation

    Institute of Scientific and Technical Information of China (English)

    MAO Xuhui; WEI Lin; HONG Song; ZHU Hua; LIN An; GAN Fuxing

    2008-01-01

    The mineralization of phenol in aerated electrochemical oxidation has been investigated. The results show that a cathodic Fenton process can occur when the Ti-0.3Mo-0.8Ni alloy material is used as cathode in solution containing ferric or ferrous ions; moreover,the reinforcement of cathodic Fenton process on the total organic carbon (TOC) removal rate of phenol is quite distinct. Among the metallic ions investigated, the ferric ion is the best catalyst for the electrochemical mineralization of phenol at initial pH 2.0, and the optimal concentration range is from 50 to 200 mg/L. The favorable pH range and supporting electrolyte (Na2SO4) concentration for mineralization of phenol in solution containing ferrous ions are 1.8-2.3 and below 0.10 mol/L, respectively. UV radiation can improve the TOC removal rate of phenol, but the enhanced effect varies in different solutions. In the solution containing ferric ions, an equal sum or synergetic effect can be observed. The optimal effect of electrolysis system under UV radiation is achieved in the solution containing 50 mg/L Fe3+ with a final removal percentage of 81.3%.

  8. Studying Equilibrium in the Chemical Reaction between Ferric and Iodide Ions in Solution Using a Simple and Inexpensive Approach

    Science.gov (United States)

    Nikolaychuk, Pavel Anatolyevich; Kuvaeva, Alyona Olegovna

    2016-01-01

    A laboratory experiment on the study of the chemical equilibrium based on the reaction between ferric and iodide ions in solution with the formation of ferrous ions, free iodine, and triiodide ions is developed. The total concentration of iodide and triiodide ions in the reaction mixture during the reaction is determined by the argentometric…

  9. Pulsed electrons of ultrahigh dose-rate effect in decreasing ferric ions of a Fricke dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rawi, A.M.; Saleh, M.M.; Al-Meshadani, N.A.F.; Al-Fakhri, K.A.K. (Baghdad Univ. (Iraq). Dept. of Chemistry)

    1983-01-01

    The yield of ferric ions produced in a Fricke dosimeter containing 10/sup -3/ M ferrous sulphate by high intensities of radiation was found to decrease with increasing dose-rates. A G(Fe/sup 3 +/) of 8.2 has been determined with dose-rates generated by the Febetron accelerator in the range 10/sup 27/ to 10/sup 29/ eVl/sup -1/ sec/sup -1/. An almost identical G(Fe/sup 3 +/) for this range of dose-rates has been evaluated by Thomas and Hart using an entirely different method.

  10. Pulsed electrons of ultrahigh dose-rate effect in decreasing ferric ions of a Fricke dosimeter

    International Nuclear Information System (INIS)

    The yield of ferric ions produced in a Fricke dosimeter containing 10-3 M ferrous sulphate by high intensities of radiation was found to decrease with increasing dose-rates. A G(Fe3+) of 8.2 has been determined with dose-rates generated by the Febetron accelerator in the range 1027 to 1029 eVl-1 sec-1. An almost identical G(Fe3+) for this range of dose-rates has been evaluated by Thomas and Hart using an entirely different method. (author)

  11. Photodegradation of bisphenol A in simulated lake water containing algae, humic acid and ferric ions

    International Nuclear Information System (INIS)

    The photodegradation of bisphenol A (BPA), a suspected endocrine disruptor (ED), in simulated lake water containing algae, humic acid and Fe3+ ions was investigated. Algae, humic acid and Fe3+ ions enhanced the photodegradation of BPA. Photodegradation efficiency of BPA was 36% after 4 h irradiation in the presence of 6.5 x 109 cells L-1 raw Chlorella vulgaris, 4 mg L-1 humic acid and 20 μmol L-1 Fe3+. The photodegradation efficiency of BPA was higher in the presence of algae treated with ultrasonic than that without ultrasonic. The photodegradation efficiency of BPA in the water only containing algae treated with ultrasonic was 37% after 4 h irradiation. The algae treated with heating can also enhance the photodegradation of BPA. This work helps environmental scientists to understand the photochemical behavior of BPA in lake water. - Algae, humic acid and ferric ions can induce the photodegradation of bisphenol A in an aqueous environment

  12. Photodegradation of bisphenol A in simulated lake water containing algae, humic acid and ferric ions

    Energy Technology Data Exchange (ETDEWEB)

    Peng Zhang' e [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: zhepeng@126.com; Wu Feng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: fengwu@whu.edu.cn; Deng Nansheng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: nsdengwhu@163.com

    2006-12-15

    The photodegradation of bisphenol A (BPA), a suspected endocrine disruptor (ED), in simulated lake water containing algae, humic acid and Fe{sup 3+} ions was investigated. Algae, humic acid and Fe{sup 3+} ions enhanced the photodegradation of BPA. Photodegradation efficiency of BPA was 36% after 4 h irradiation in the presence of 6.5 x 10{sup 9} cells L{sup -1} raw Chlorella vulgaris, 4 mg L{sup -1} humic acid and 20 {mu}mol L{sup -1} Fe{sup 3+}. The photodegradation efficiency of BPA was higher in the presence of algae treated with ultrasonic than that without ultrasonic. The photodegradation efficiency of BPA in the water only containing algae treated with ultrasonic was 37% after 4 h irradiation. The algae treated with heating can also enhance the photodegradation of BPA. This work helps environmental scientists to understand the photochemical behavior of BPA in lake water. - Algae, humic acid and ferric ions can induce the photodegradation of bisphenol A in an aqueous environment.

  13. Ion sorption onto hydrous ferric oxides: Effect on major element fluid chemistry at Aespoe, Sweden

    International Nuclear Information System (INIS)

    The observed variability of fluid chemistry at the Aespoe Hard Rock Laboratory is not fully described by conservative fluid mixing models. Ion exchange may account for some of the observed discrepancies. It is also possible that variably charged solids such as oxyhydroxides of Fe can serve as sources and sinks of anions and cations through surface complexation. Surface complexation reactions on hydrous ferric oxides involve sorption of both cations and anions. Geochemical modeling of the surface chemistry of hydrous ferric oxides (HFOs) in equilibrium with shallow HBH02 and deep KA0483A waters shows that HFOs can serve as significant, pH-sensitive sources and sinks for cations and anions. Carbonate sorption is favored especially at below-neutral pH. A greater mass of carbonate is sorbed onto HFO surfaces than is contained in the fluid when 10 g goethite, used as a proxy for HFOs, is in contact with 1 kg H2O. The masses of sorbent required to significantly impact fluid chemistry through sorption/desorption reactions seem to be reasonable when compared to the occurrences of HFOs at Aespoe. Thus, it is possible that small changes in fluid chemistry can cause significant releases of cations or anions from HFOs into the fluid phase or, alternately, result in uptake of aqueous species onto HFO surfaces. Simulations of the mixing of shallow HBH02 and native KA0483A waters in the presence of a fixed mass of goethite show that surface complexation does not cause the concentrations of Ca, Sr, and SO4 to deviate from those that are predicted using conservative mixing models. Results for HCO3 are more difficult to interpret and cannot be addressed adequately at this time

  14. The influence of ferrous/ferric ions on the efficiency of photocatalytic oxidation of pollutants in groundwater.

    Science.gov (United States)

    Klauson, D; Preis, S; Portjanskaja, E; Kachina, A; Krichevskaya, M; Kallas, J

    2005-06-01

    The complex influence of ferrous/ferric ions on the efficiency of aqueous photocatalytic oxidation (PCO) of 2-ethoxyethanol (2-EE), methyl tert-butyl ether (MTBE) and humic substances (HS) was established. A drastic efficiency increase at lower concentration of ferrous/ferric ions was observed to change to a sharp decrease at higher concentrations for 2-EE and MTBE, whereas for HS only an inhibitive effect of Fe2+/3+ on the PCO efficiency was noticed. The authors proposed an explanation for the observed phenomena based on the different sensitivities of pollutants towards radical-oxidation reactions and the competitive adsorption of metallic ions and pollutants on the TiO2 surface. PMID:16035658

  15. Effects of calcium and ferric ions on struvite precipitation: A new assessment based on quantitative X-ray diffraction analysis.

    Science.gov (United States)

    Yan, Hanlu; Shih, Kaimin

    2016-05-15

    The precipitation of struvite (MgNH4PO4·6H2O) from waste streams has attracted considerable attention due to its potential for recovering phosphorus for fertilization. As struvite is primarily acquired by means of precipitation and crystallization from aqueous solutions, it is important to evaluate the roles of common metal ions, particularly those that are commonly found in wastewater, in the struvite crystallization process. This study was performed to quantitatively evaluate the effects of calcium and ferric ions on struvite crystallization using the Rietveld refinement method, which is based on the analysis of X-ray diffraction data. The results indicate that both calcium and ferric ions significantly inhibit the formation of struvite crystals, and the effects vary under different pH conditions. There was a negative linear correlation between the struvite weight content in the precipitates and the Ca/Mg molar ratio in the initial solution. However, ferric ions were confirmed to be a more efficient inhibitor of struvite crystallization. Ca(2+) and Fe(3+) further modified the needle-like struvite into irregular shapes. An unambiguous and quantitative understanding of the effects of foreign ions on struvite crystallization will help to reliably improve the quality of struvite products recovered from wastewater and the control of struvite deposits in water and sludge piping systems. PMID:27016641

  16. Effects of ferric ions on the catalytic ozonation process on sanitary landfill leachates

    Directory of Open Access Journals (Sweden)

    Messias Borges Silva

    2013-04-01

    Full Text Available Leachates exhibiting an unstable ratio of biochemical oxygen demand (BOD and chemical oxygen demand (COD of approximately 0.45 are typical of new landfills in the City of Cachoeira Paulista, Brazil. Although the organic matter portion is bio-treatable, the presence of refractory leached organic material requires unconventional effluent-treatment processes. Leachate treatment with ozone oxidation, in the presence of ferric ions, acts as catalyst in the formation of hydroxyl radicals. Ozone was obtained by corona-discharge from high-purity O2 gas. The treatment was performed in natura in a jacketed borosilicate glass reactor containing 900 ml of leachate. The analyzed response variable was expressed as the concentration of dissolved organic carbon (DOC. In order to determine the optimal proportions to produce the greatest degradation rate for organic materials, variations in experimental O2 flow-fed to the generator, the Fe(iii concentration, and the output of the ozonator were conducted over two experimental runs. Experimental models showed a DOC degradation on the order of 81.25%.

  17. Ferric ion-assisted in situ synthesis of silver nanoplates on polydopamine-coated silk.

    Science.gov (United States)

    Xiao, Jing; Zhang, Huihui; Mao, Cuiping; Wang, Ying; Wang, Ling; Lu, Zhisong

    2016-10-01

    In the present study, a ferric ion (Fe(3+))-assisted in situ synthesis approach was developed to grow silver (Ag) nanoplates on the polydopamine (PDA)-coated silk without the use of additional reductants. The essential role of Fe(3+) in the formation of Ag nanoplates is revealed by comparing the morphologies of Ag nanostructures prepared on the silk-coated PDA film with/without Fe(3+) doping. Scanning electron micrographs show that high-density Ag nanoplates could be synthesized in the reaction system containing 50μg/mL FeCl3 and 50mM AgNO3. The size of the Ag nanoplate could be tuned by adjusting the reaction duration. Based on the data, a mechanism involving the Fe(3+)-selected growth of Ag atoms along the certain crystal faces was proposed to explain the fabrication process. Transmission electron microscopy and X-ray diffractometry indicate that the Ag nanoplates possess good crystalline structures. Raman spectra demonstrate that the nanoplates could strongly enhance the Raman scattering of the PDA molecules. The Ag nanoplate-coated silk could be utilized as a flexible substrate for the development of surface-enhanced Raman scattering biosensors. PMID:27390855

  18. In vitro binding of plutonium to human transferrin and competition reaction with ferric ions

    International Nuclear Information System (INIS)

    Plutonium was found to bind strongly to human transferrin, however a maximum capacity of absorption was observed. Presaturation with iron of transferrin resulted in a decrease of plutonium binding, but it still remained appreciable. It was largely affected by the pH as well as by the degree of ferric saturation of the transferrin. (authors)

  19. Removal of some heavy metals from industrial waste water using polyacrylamide ferric antimonate as new ion exchange material

    International Nuclear Information System (INIS)

    Composite ion exchangers consist of one or more ion exchangers combined with another material, which can be inorganic or organic and may it be an ion exchanger. The reason for manufacturing a composite material is to produce a granular material, with sufficient strength for column use, from ion exchangers that do not form, or only form weak, granules themselves. Attempts in this study are focused to prepare composite ion exchangers for treatment of wastewater. Heavy metals when present in water in concentrations exceeding the permitted limits are injurious to the health. Hence, it is very important to treat such waters to remove the metal ions present before it is supplied for any useful purpose. Therefore, many investigations have studied to develop more effective process to treat such waste stream. Ion-exchange has been widely adopted in heavy metal containing wastewater and most of the ion-exchangers (i.e. ion-exchange media) currently being used are commercially mass-produced organic resins.Therefore, the main aim of this work is directed to find the optimum conditions for removal of some heavy metals from industrial waste water.1-Preparation of polyacrylamide ferric antimonate composite.2-Characterization of the prepared exchanger using IR spectra, X-ray diffraction pattern, DTA and TG analyses.3-Chemical stability, capacity and equilibrium measurements will be determined on the materials using at different conditions (ph heating temperature and reaction temperature).4-Kinetic studies of some heavy metals.5-Ion exchange isotherm.6-Breakthrough curves for removal of the investigated metal ions on the prepared exchanger under certain condition.

  20. [Stabilization of Cadmium Contaminated Soils by Ferric Ion Modified Attapulgite (Fe/ATP)--Characterizations and Stabilization Mechanism].

    Science.gov (United States)

    Rong, Yang; Li, Rong-bo; Zhou, Yong-li; Chen, Jing; Wang, Lin-ling; Lu, Xiao-hua

    2015-08-01

    Ferric ion modified attapulgite (Fe/ATP) was prepared by impregnation and its structure and morphology were characterized. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effect of Cadmium( Cd) stabilization in soil with the addition of attapulgite (ATP) and Fe/ATP. The stabilization mechanism of Cd was further elucidated by comparing the morphologies and structure of ATP and Fe/ATP before and after Cd adsorption. Fe/ATP exhibited much better adsorption capacity than ATP, suggesting different adsorption mechanisms occurred between ATP and Fe/ATP. The leaching concentrations of Cd in soil decreased by 45% and 91% respectively, with the addition of wt. 20% ATP and Fe/ATP. The former was attributed to the interaction between Cd2 and --OH groups by chemical binding to form inner-sphere complexes in ATP and the attachment between Cd2+ and the defect sites in ATP framework. Whereas Cd stabilization with Fe/ATP was resulted from the fact that the active centers (--OH bonds or O- sites) on ATP could react with Fe3+ giving Fe--O--Cd-- bridges, which helped stabilize Cd in surface soil. What'more, the ferric oxides and metal hydroxides on the surface of ATP could interact with Cd, probably by the formation of cadmium ferrite. In conclusion, Fe/ATP, which can be easily prepared, holds promise as a potential low-cost and environmental friendly stabilizing agent for remediation of soil contaminated with heavy metals. PMID:26592037

  1. High spatial frequency periodic structures induced on ferric ion-doped Polyvinyl Pyrrolidone film by femtosecond laser pulses

    CERN Document Server

    Lai, Chen; Wang, Yunxia; Li, Qiang; Wu, Lijun

    2016-01-01

    Utilizing continues-wave or pulsed laser to induce nano-structures on various material surfaces is one significant method in nano-fabrication technology. In this report, we investigate the formation of high spatial frequency periodic structures on Polyvinyl Pyrrolidone (PVP) film by a linearly polarized femtosecond laser. Ferric (Fe) ions are introduced into the film to improve the photosensitivity. Regular nano-gratings with spatial periods at the range of 60-100nm, which are about one tenth of the irradiating wavelength, can be induced. The period direction of the nano-gratings is perpendicular to the polarization of the femtosecond laser. By tuning the laser energy and scanning speed, we find that the nano-gratings can be formed in a wide range of experimental parameters. As high laser energy can excite not only metals, but also semiconductors and polymers, we believe the formation of the nano-gratings is due to the interaction between the incident femtosecond laser and surface plasmons. The laser processa...

  2. SEQUENTIAL EXTRACTION OF PHOSPHORUS BY MEHLICH-1 AND ION EXCHANGE RESIN FROM B HORIZONS OF FERRIC AND PERFERRIC LATOSOLS (OXISOLS

    Directory of Open Access Journals (Sweden)

    Danilo de Lima Camêlo

    2015-08-01

    Full Text Available In general, Latosols have low levels of available P, however, the influence of the parent material seems to be decisive in defining the pool and predominant form of P in these soils. This study evaluated P availability by extraction with Mehlich-1 (M-1 and Ion Exchange Resin (IER, from samples of B horizons of Ferric and Perferric Latosols developed from different parent materials. To this end, in addition to the physical and chemical characterization of soils, 10 sequential extractions were performed with M-1 and IER from samples of B horizons (depth between 0.8 and 1.0 m. Total contents of Ca, P, Fe, Al, and Ti were determined after digestion with nitric, hydrofluoric and perchloric acids. The effects of sequential P extractions on Fe oxides were also evaluated from the analyses of dithionite-citrate-bicarbonate and ammonium acid oxalate. The high similarity between contents of P accumulated after sequential extractions with M-1 and IER in soils developed on tuffite indicated a predominance of P-Ca. Higher contents of P after a single IER extraction show greater efficiency in P removal from highly weathered soils, as from the Latosols studied here. The P contents also show the high sensitivity of extractant M-1 in highly buffered soils. Furthermore, a single extraction with extractant M-1 or IER is not sufficient to estimate the amount of labile P in these soils.

  3. A study on the cementation of the regenerated cesium activity containing ferric, generated from elution of spent ion exchange resin

    International Nuclear Information System (INIS)

    For the studies on the cementation of the regenerated activity, 50 mL of 0.3 μCi Cs was taken with different strengths of ferric, viz. 0.5 N to 11 N,. The pH of the cement and ferric solutions of different strength was studied. Compressive strength studies of the cement blocks showed that at all strengths of ferric used for making the cement blocks, it was maximum at the 4th week and hence the curing time was fixed as 4 weeks

  4. The influence of Ferric ion contamination on the solid polymer electrolyte water electrolysis performance

    International Nuclear Information System (INIS)

    Highlights: • The cathode possesses higher tolerance for the Fe3+ contamination than the anode. • Fe3+ are mostly reduced to Fe2+ rather than occur underpotential deposition. • Increased electrolysis voltage was mainly attributed to ohmic overpotential. • Voltage lags behind current for minutes in the multi-current-step test. • Poisoned electrolyser is mostly recovered by 0.5 M H2SO4 solution treatment for 13 h. - Abstract: Fe3+ is a sort of common metal ion contaminant for the solid polymer electrolyte (SPE) water electrolyser. In this paper, the effect of Fe3+ on the performance of SPE water electrolyser has been investigated by both in-situ and ex-situ characterizations. The electron probe microanalysis and ultraviolet test results showed that Fe3+ could migrate from the anode to the cathode and mostly be reduced to Fe2+ in the cathode rather than occurred underpotential deposition as described in the previous report. The in-situ dynamic contamination test showed that the anode voltage increased sharply as soon as the Fe3+ was fed into the anode, while the cathode voltage kept constant until the contamination time was over 30 minutes, indicating the higher tolerance of the cathode than the anode for the Fe3+ contamination. The calculation results based on the electrochemistry impedance spectroscopy test results revealed that the striking increase of the electrolysis voltage was mainly attributed to the ohmic overpotential, which was due to the replacement of H+ by Fe3+ in the Nafion resin. Interestingly, the voltage lagged behind the current for several minutes in the multi-current-step test for the contaminated electrolyser, which phenomenon may be used for judging whether the SPE water electrolyser performance degradation is due to the metal ions contamination. Furthermore, recovery strategy has been developed, and it was found that the contaminated electrolyser could be mostly recovered by 0.5 M H2SO4 solution treatment for 13 h

  5. Effects of Magnesium and Ferric Ions on Crystallization of Calcium Sulfate Dihydrate Under the Simulated Conditions of Wet Flue-gas Desulfurization

    Institute of Scientific and Technical Information of China (English)

    GAO Xiang; HUO Wang; ZHONG Yi; LUO Zhong-yang; CEN Ke-fa; NI Ming-jiang; CHEN Le-ming

    2008-01-01

    The influences of magnesium and ferric ions in their different ratios on the rate of gypsum crystallization were studied under the conditions similar to those of wet flue-gas desulfurization(WFGD).The results show thataddition of both Mg2+ and Fe3+ increased induction time and decreased the growth efficiency up to 50% compared with the baseline(without impurities) depending on the concentration and the type of impurity.The effects of Mg2+ and Fe3+ on the surface energy and the rate of nucleation were estimated by employing the classical nucleation theory.The surface energy decreased by 8% and 14% with the addition of 0.02 mol/L magnesium or ferric ions,respectively,compared to the baseline.Mg2+ and Fe3+ made the growth rate of the (020),(021) and (040) faces of gypsum crystal a much greater reduction,which leads to the formation of needle crystals compared to the baseline which favors the formation of plate or flakes.Furthermore,an edge detection program was developed to quantify the effects of impurities on the filtration rate of gypsum product.The results show that the inhibition efficiency of the presence of 0.02 mol/L Mg2+ and Fe3+ on the filtration rate of gypsum crystal ranges from 22% to 39%.

  6. Biological regeneration of ferric (Fe3+) solution during desulphurisation of gaseous streams: effect of nutrients and support material.

    Science.gov (United States)

    Mulopo, Jean; Schaefer, L

    2015-01-01

    This paper evaluates the biological regeneration of ferric Fe3+ solution during desulphurisation of gaseous streams. Hydrogen sulphide (H2S) is absorbed into aqueous ferric sulphate solution and oxidised to elemental sulphur, while ferric ions Fe3+ are reduced to ferrous ions Fe2+. During the industrial regeneration of Fe3+, nutrients and trace minerals usually provided in a laboratory setup are not present and this depletion of nutrients may have a negative impact on the bacteria responsible for ferrous iron oxidation and may probably affect the oxidation rate. In this study, the effect of nutrients and trace minerals on ferrous iron oxidation have been investigated and the results showed that the presence of nutrients and trace minerals affects the efficiency of bacterial Fe2+oxidation. The scanning electron microscopy analysis of the geotextile support material was also conducted and the results showed that the iron precipitate deposits appear to play a direct role on the bacterial biofilm formation. PMID:26038932

  7. Bacterial adhesion on ion-implanted stainless steel surfaces

    International Nuclear Information System (INIS)

    Stainless steel disks were implanted with N+, O+ and SiF3+, respectively at the Surrey Ion Beam Centre. The surface properties of the implanted surfaces were analyzed, including surface chemical composition, surface topography, surface roughness and surface free energy. Bacterial adhesion of Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus, which frequently cause medical device-associated infections was evaluated under static condition and laminar flow condition. The effect of contact time, growth media and surface properties of the ion-implanted steels on bacterial adhesion was investigated. The experimental results showed that SiF3+-implanted stainless steel performed much better than N+-implanted steel, O+-implanted steel and untreated stainless steel control on reducing bacterial attachment under identical experimental conditions

  8. Bacterial adhesion on ion-implanted stainless steel surfaces

    Science.gov (United States)

    Zhao, Q.; Liu, Y.; Wang, C.; Wang, S.; Peng, N.; Jeynes, C.

    2007-08-01

    Stainless steel disks were implanted with N +, O + and SiF 3+, respectively at the Surrey Ion Beam Centre. The surface properties of the implanted surfaces were analyzed, including surface chemical composition, surface topography, surface roughness and surface free energy. Bacterial adhesion of Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus, which frequently cause medical device-associated infections was evaluated under static condition and laminar flow condition. The effect of contact time, growth media and surface properties of the ion-implanted steels on bacterial adhesion was investigated. The experimental results showed that SiF 3+-implanted stainless steel performed much better than N +-implanted steel, O +-implanted steel and untreated stainless steel control on reducing bacterial attachment under identical experimental conditions.

  9. Sodium Ferric Gluconate Injection

    Science.gov (United States)

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  10. Photochemical transformation of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) in surface coastal waters: Effects of chloride and ferric ions

    International Nuclear Information System (INIS)

    Highlights: • Chloride ion promoted the phototransformation of BDE-47 in Fe(III) solution. • In Fe(III) solution, the added Cl− could influence the generation of ·OH. • The chlorinated PBDEs were found in Fe(III) + Cl− solution under irradiation. • These results showed the likely fate of PBDEs in the marine environment. - Abstract: The effects of several aquatic environmental factors on the photochemical transformation of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) have been investigated. Ferric ion (Fe(III)) has been found to promote the phototransformation of BDE-47, and this process is further enhanced with the added chloride ion (Cl−), while it is suppressed with increasing pH. Electron spin resonance results show that the formation of hydroxyl radical, and the added Cl− could influence the generation of hydroxyl radical in Fe(III) solution. Hence, Cl− enhances the phototransformation of BDE-47 most probably because of the reaction with Fe(III) species under irradiation, yielding hydroxyl and chloride radicals. These radicals can not only decompose PBDEs, but also lead to their photodebromination and photochlorination. These results indicate that the aquatic environmental factors and Cl− in particular played an important role in the photochemical transformation process of PBDEs, providing insight into the likely fate of PBDEs in the marine environment

  11. Effect of ferrous/ferric ions molar ratio on reaction mechanism for hydrothermal synthesis of magnetite nanoparticles

    Indian Academy of Sciences (India)

    N Mizutani; T Iwasaki; S Watano; T Yanagida; H Tanaka; T Kawai

    2008-10-01

    Magnetite nanoparticles were prepared by hydrothermal synthesis under various initial ferrous/ferric molar ratios without adding any oxidizing and reducing agents in order to clarify effects of the molar ratio on the reaction mechanism for the formation of magnetite nanoparticles. The magnetite nanoparticles prepared were characterized by a scanning electron microscope, powder X-ray diffractometer, and superconducting quantum interference device (SQUID). At the molar ratio corresponding to the stoichiometric ratio in the synthesis reaction of magnetite from ferrous hydroxide and goethite, the nucleation of magnetite crystals progressed rapidly in an initial stage of the hydrothermal synthesis, resulting in formation of the magnetite nanoparticles having a smaller size and a lower crystallinity. On the other hand, at higher molar ratios, the particle size and crystallinity increased with increasing molar ratio because using surplus ferrous hydroxide the crystallites of magnetite nanoparticles grew up slowly under hydrothermal conditions according to the Schikorr reaction. The magnetite nanoparticles prepared under various molar ratios had good magnetic properties regardless of the molar ratio.

  12. Identification and characterization of a bacterial hydrosulphide ion channel

    Energy Technology Data Exchange (ETDEWEB)

    Czyzewski, Bryan K.; Wang, Da-Neng (NYUSM)

    2012-10-26

    The hydrosulphide ion (HS{sup -}) and its undissociated form, hydrogen sulphide (H{sub 2}S), which are believed to have been critical to the origin of life on Earth, remain important in physiology and cellular signalling. As a major metabolite in anaerobic bacterial growth, hydrogen sulphide is a product of both assimilatory and dissimilatory sulphate reduction. These pathways can reduce various oxidized sulphur compounds including sulphate, sulphite and thiosulphate. The dissimilatory sulphate reduction pathway uses this molecule as the terminal electron acceptor for anaerobic respiration, in which process it produces excess amounts of H{sub 2}S. The reduction of sulphite is a key intermediate step in all sulphate reduction pathways. In Clostridium and Salmonella, an inducible sulphite reductase is directly linked to the regeneration of NAD{sup +}, which has been suggested to have a role in energy production and growth, as well as in the detoxification of sulphite. Above a certain concentration threshold, both H{sub 2}S and HS{sup -} inhibit cell growth by binding the metal centres of enzymes and cytochrome oxidase, necessitating a release mechanism for the export of this toxic metabolite from the cell. Here we report the identification of a hydrosulphide ion channel in the pathogen Clostridium difficile through a combination of genetic, biochemical and functional approaches. The HS{sup -} channel is a member of the formate/nitrite transport family, in which about 50 hydrosulphide ion channels form a third subfamily alongside those for formate (FocA) and for nitrite (NirC). The hydrosulphide ion channel is permeable to formate and nitrite as well as to HS{sup -} ions. Such polyspecificity can be explained by the conserved ion selectivity filter observed in the channel's crystal structure. The channel has a low open probability and is tightly regulated, to avoid decoupling of the membrane proton gradient.

  13. Leaching of Zinc Sulfide by Thiobacillus ferrooxidans: Experiments with a Controlled Redox Potential Indicate No Direct Bacterial Mechanism

    OpenAIRE

    Fowler, T. A.; Crundwell, F. K.

    1998-01-01

    The role of Thiobacillus ferrooxidans in bacterial leaching of mineral sulfides is controversial. Much of the controversy is due to the fact that the solution conditions, especially the concentrations of ferric and ferrous ions, change during experiments. The role of the bacteria would be more easily discernible if the concentrations of ferric and ferrous ions were maintained at set values throughout the experimental period. In this paper we report results obtained by using the constant redox...

  14. Effect of dissolved ozone or ferric ions on photodegradation of thiacloprid in presence of different TiO2 catalysts

    International Nuclear Information System (INIS)

    Combining TiO2 photocatalysis with inorganic oxidants (such as O3 and H2O2) or transition metal ions (Fe3+, Cu2+ and Ag+) often leads to a synergic effect. Electron transfer between TiO2 and the oxidant is usually involved. Accordingly, the degree of synergy could be influenced by TiO2 surface area. With this in mind, the disappearance of thiacloprid, a neonicotinoid insecticide, was studied applying various photochemical AOPs and different TiO2 photocatalysts. In photocatalytic ozonation experiments, synergic effect of three different TiO2 photocatalysts was quantified. Higher surface area resulted in a more pronounced synergic effect but an increasing amount of TiO2 did not influence the degree of the synergy. This supports the theory that the synergy is a consequence of adsorption of ozone on the TiO2 surface. No synergy was observed in photocatalytic degradation of thiacloprid in the presence of dissolved iron(III) species performed under varied experimental conditions (concentration, age of iron(III) solution, different TiO2 films, usage of TiO2 slurries). This goes against the literature for different organic compounds (i.e., monuron). It indicates different roles of iron(III) in the photodegradation of different organic molecules. Moreover, TiO2 surface area did not affect photodegradation efficiency in iron(III)-based experiments which could confirm absence of electron transfer between TiO2 photocatalyst and iron(III).

  15. Enhancement of the binding affinity of methylene blue to site I in human serum albumin by cupric and ferric ions.

    Science.gov (United States)

    He, Ling-Ling; Wang, Yong-Xia; Wu, Xiao-Xia; Liu, Xian-Ping; Wang, Xin; Liu, Bin; Wang, Xin

    2015-12-01

    In this work, the binding characteristics of methylene blue (MB) to human serum albumin (HSA) and the influence of Cu(2+) and Fe(3+) on the binding affinity of MB to HSA were investigated using fluorescence, absorption, circular dichroism (CD) spectroscopy and molecular modelling. The results of competitive binding experiments using the site probes ketoprofen and ibuprofen as specific markers suggested that MB was located in site I within sub-domain IIA of HSA. The molecular modelling results agreed with the results of competitive site marker experiments and the results of CD spectra indicated that the interaction between MB and HSA caused the conformational changes in HSA. The binding affinity of MB to HSA was enhanced but to a different extent in the presence of Cu(2+) and Fe(3+), respectively, which indicated that the influence of different metal ions varied. Enhancement of the binding affinity of MB to HSA in the presence of Cu(2+) is due to the formation of Cu(2+)-HSA complex leading to the conformational changes in HSA, whereas in the presence of Fe(3+), enhancement of the binding affinity is due to the greater stability of the Fe(3+)-HSA-MB complex compared with the MB-HSA complex. PMID:25833007

  16. Sodium Ferric Gluconate Injection

    Science.gov (United States)

    ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of medications called iron replacement products. It works by replenishing iron stores so ...

  17. Ferric Carboxymaltose Injection

    Science.gov (United States)

    ... is in a class of medications called iron replacement products. It works by replenishing iron stores so ... iron dextran (Dexferrum, Infed), iron sucrose (Venofer), or sodium ferric gluconate (Ferrlecit); any other medications, or any ...

  18. FERRIC ION-SPECIFIC SEQUESTERING AGENTS. 7. SYNTHESIS, IRON EXCHANGE KINETICS, AND STABILITY CONSTANTS OF N-SUBSTITUTED, SULFONATED CATECHOYLAMIDE ANALOGUES OF ENTEROBACTIN.

    Energy Technology Data Exchange (ETDEWEB)

    Pecoraro, Vincent L.; Weitl, Frederick L.; Raymond, Kenneth N.

    1980-10-01

    For treatment of chronic iron overload (as occurs in Cooley's anemia), ferric ion sequestering agents with specific properties are necessary. Two analogues of enterobactin [a microbial chelating agent with the greatest stability constant known for an Fe(III) complex] are reported which exhibit: i) hydrolytic stability; ii) water solubility; iii) N-substitution to block peptidase hydrolysis. The first compound, N,N',N"- trimethyl-N,N',N"-tris(2,3-dihydroxysulfobenzoyl)1,3,5-triaminomethyl- benzene, [Me{sub 3}MECAMS, 6] was prepared from the amide of trimesloyl chloride (1) and MeNH{sub 2}. The resulting amide was reduced to the triamine (3) and converted in three steps to the final product 6 in 6% overall yield. The proton-dependent formation constant (log K*) for the reaction: Fe{sup 3+} + H{sub 3}L{sup 6-} = FeL{sup 6-} + 3H{sup +} is 4.87, which gives an equilibrium concentration of [Fe{sup 3+}] at pH 7.4 of 2 x 10{sup -27} M for 10{sup -5} M L (6) and 10{sup -6} M total Fe{sup 3+}. The estimated formation constant (log {beta}{sub 110}) is 40. At low pH the FeL{sup 6-} complex undergoes a series of three, one-proton reactions which probably gives a tris-salicylate complex formed by the carbonyl and ortho-catechol oxygen of the 2,3~dihydroxybenzoyl units (the same reaction that occurs with ferric enterobactin). After six hours in the presence of 6 mM ascorbate, Me{sub 3}MECAMS (6.0 mM) removed 3.7% of the ferric ion initially sequestered by the iron storage protein, ferritin. The human iron transport protein transferrin goves up iron to Me{sub 3}MECAMS with a pseudo first-order rate constant of 1.9 x 10{sup -3}min{sup -1} (ligand concentration 2 X 10{sup -4} M). This rate is comparable to that of enterobactin and other catechoyl amide sequestering agents. and greatly exceeds that of desferrioxamine B (Desferal{reg-sign}). the current drug of choice in treating iron overload. Two related compounds have been prepared in which the catechol ring is

  19. Arsenic Removal from Water Using Various Adsorbents: Magnetic Ion Exchange Resins, Hydrous Ion Oxide Particles, Granular Ferric Hydroxide, Activated Alumina, Sulfur Modified Iron, and Iron Oxide-Coated Microsand

    KAUST Repository

    Sinha, Shahnawaz

    2011-09-30

    The equilibrium and kinetic adsorption of arsenic on six different adsorbents were investigated with one synthetic and four natural types (two surface and two ground) of water. The adsorbents tested included magnetic ion exchange resins (MIEX), hydrous ion oxide particles (HIOPs), granular ferric hydroxide (GFH), activated alumina (AA), sulfur modified iron (SMI), and iron oxide-coated mic - rosand (IOC-M), which have different physicochemical properties (shape, charge, surface area, size, and metal content). The results showed that adsorption equilibriums were achieved within a contact period of 20 min. The optimal doses of adsorbents determined for a given equilibrium concentration of C eq = 10 μg/L were 500 mg/L for AA and GFH, 520–1,300 mg/L for MIEX, 1,200 mg/L for HIOPs, 2,500 mg/L for SMI, and 7,500 mg/L for IOC-M at a contact time of 60 min. At these optimal doses, the rate constants of the adsorbents were 3.9, 2.6, 2.5, 1.9, 1.8, and 1.6 1/hr for HIOPs, AA, GFH, MIEX, SMI, and IOC-M, respectively. The presence of silicate significantly reduced the arsenic removal efficiency of HIOPs, AA, and GFH, presumably due to the decrease in chemical binding affinity of arsenic in the presence of silicate. Additional experiments with natural types of water showed that, with the exception of IOC-M, the adsorbents had lower adsorption capacities in ground water than with surface and deionized water, in which the adsorption capacities decreased by approximately 60–95 % .

  20. The influence of ferric (III citrate on ATP-hydrolases of Desulfuromonas acetoxidans ІМV В-7384

    Directory of Open Access Journals (Sweden)

    O. Maslovska

    2013-02-01

    Full Text Available Desulfuromonas acetoxidans obtains energy for growth by the anaerobic oxidation of organic compounds with the carbon dioxide formation. It was found that ferrum and manganese are used as terminal electron acceptors in the processes of anaerobic respiration, such as dissimilative Fe3+- and Mn4+-reduction, carried out by these bacteria (Lovely, 1991. D. acetoxidans ІМV B-7384 can be used as anode biocatalyst in microbial fuel cell with high electron recovery through acetate oxidation to the electric current as a result of electron transfer to the anode or 3d-type transition metals, such as ferrum and manganese, in the process of their reduction. Investigation of biochemical changes of D. acetoxidans ІМV B-7384 under the influence of Fe (III compounds is important for optimization of the process of bacterial electricity generation. ATP-hydrolase is located in cytoplasmic membrane, and its subunits are exposed to both the cytoplasm and the external environment. Therefore, the changes of that enzyme activity can be used as an indicator of various stress exposure. Presence of ferric iron ions in the bacterial growth medium could catalyze generation of organic reactive oxygen species, such as peroxyl (ROO- and alkoxyl (RO- radicals. Lipid peroxidation is one of the main reasons of cell damage and it’s following death under the influence of reactive oxygen metabolites. It is known that lipid peroxidation and membrane transport processes are somehow interrelated, but mechanisms of such interaction are still unidentified. In our previous researche we have shown the influence of ferric (III citrate on the intensity of lipid peroxidation of D. аcetoxidans ІМV В-7384. Significant increase of the content of lipid peroxidation products (lipid hydroperoxides, conjugated dienes and malondialdehyde in bacterial cells has been observed under the addition of ferric (III citrate into the cultural medium. The increase of the concentration of lipid

  1. Bacterial Indicators and Metal Ions in High Mountain Lake Waters

    OpenAIRE

    Savvaidis, I.; Kegos, Th.; Papagiannis, C.; Voidarou, C.; Tsiotsias, A.; Maipa, V.; Kalfakakou, V.; Evangelou, A.; E. Bezirtzoglou

    2011-01-01

    Bacterial indicators, including total coliforms, fecal coliforms, total Streptococci, Enterococci and Clostridium perfringens, were evaluated in alpine lake water environments at elevated altitudes in the Pindos mountain region. Classical methods and techniques were used for the isolation and characterization of indicator microorganisms and a selective nutrient medium supplemented with lactose-sulphite (LS) for the rapid determination of C. perfringens. In most lake samples examined, low numb...

  2. Stochastic pumping of ions based on colored noise in bacterial channels under acidic stress.

    Science.gov (United States)

    López, M Lidón; Queralt-Martín, María; Alcaraz, Antonio

    2016-07-21

    Fluctuation-driven ion transport can be obtained in bacterial channels with the aid of different types of colored noise including the biologically relevant Lorentzian one. Using the electrochemical rectification of the channel current as a ratchet mechanism we observe transport of ions up to their concentration gradient under conditions similar to that met in vivo, namely moderate pH gradients and asymmetrically charged lipid membranes. We find that depending on the direction of the concentration gradient the channel can pump either cations or anions from the diluted side to the concentrated one. We discuss the possible relevance of this phenomenon for the pH homeostasis of bacterial cells. PMID:27349445

  3. Modification of anti-bacterial surface properties of textile polymers by vacuum arc ion source implantation

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaev, A.G., E-mail: nik@opee.hcei.tsc.ru [High Current Electronics Institute, Siberian Branch of the Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Yushkov, G.Yu.; Oks, E.M. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Oztarhan, A. [Izmir University, Izmir 35140 (Turkey); Akpek, A.; Hames-Kocabas, E.; Urkac, E.S. [Bioengineering Department, Ege University, Bornova 35100, Izmir (Turkey); Brown, I.G. [Lawrence Berkeley National Laboratory, Berkeley, CA 94708 (United States)

    2014-08-15

    Highlights: • Ion implantation. • Anti-bacterial properties. • Textile polymer. • Vacuum arc ion source. - Abstract: Ion implantation provides an important technology for the modification of material surface properties. The vacuum arc ion source is a unique instrument for the generation of intense beams of metal ions as well as gaseous ions, including mixed metal–gas beams with controllable metal:gas ion ratio. Here we describe our exploratory work on the application of vacuum arc ion source-generated ion beams for ion implantation into polymer textile materials for modification of their biological cell compatibility surface properties. We have investigated two specific aspects of cell compatibility: (i) enhancement of the antibacterial characteristics (we chose to use Staphylococcus aureus bacteria) of ion implanted polymer textile fabric, and (ii) the “inverse” concern of enhancement of neural cell growth rate (we chose Rat B-35 neuroblastoma cells) on ion implanted polymer textile. The results of both investigations were positive, with implantation-generated antibacterial efficiency factor up to about 90%, fully comparable to alternative conventional (non-implantation) approaches and with some potentially important advantages over the conventional approach; and with enhancement of neural cell growth rate of up to a factor of 3.5 when grown on suitably implanted polymer textile material.

  4. Modification of anti-bacterial surface properties of textile polymers by vacuum arc ion source implantation

    International Nuclear Information System (INIS)

    Highlights: • Ion implantation. • Anti-bacterial properties. • Textile polymer. • Vacuum arc ion source. - Abstract: Ion implantation provides an important technology for the modification of material surface properties. The vacuum arc ion source is a unique instrument for the generation of intense beams of metal ions as well as gaseous ions, including mixed metal–gas beams with controllable metal:gas ion ratio. Here we describe our exploratory work on the application of vacuum arc ion source-generated ion beams for ion implantation into polymer textile materials for modification of their biological cell compatibility surface properties. We have investigated two specific aspects of cell compatibility: (i) enhancement of the antibacterial characteristics (we chose to use Staphylococcus aureus bacteria) of ion implanted polymer textile fabric, and (ii) the “inverse” concern of enhancement of neural cell growth rate (we chose Rat B-35 neuroblastoma cells) on ion implanted polymer textile. The results of both investigations were positive, with implantation-generated antibacterial efficiency factor up to about 90%, fully comparable to alternative conventional (non-implantation) approaches and with some potentially important advantages over the conventional approach; and with enhancement of neural cell growth rate of up to a factor of 3.5 when grown on suitably implanted polymer textile material

  5. Biosorption of some ions on different bacterial species from aqueous and radioactive waste solutions

    International Nuclear Information System (INIS)

    The uptake of metal ions, cerium, Ce(III); cobalt, Co(II); thorium, Th(IV); and uranium U(VI) by Bacillus pumilus-LRW1, Bacillus cereus-LRW2 and Micrococcus lylae-LRW3 from aqueous solution was examined as a function of metal ion concentration, pH, temperature, and the presence of some foreign ions. The bacterial species exhibited high affinity to accumulate metal ions from their solutions at pH 4-5.0 ± 0.5. The amount of each ion (in mg) accumulated by one gram dry weight of each bacteria was calculated. The uptake by the Bacillus cereus-LRW2 from aqueous solutions and simulated radioactive wastes were also investigated. Electron microscopic investigations showed that the ions were accumulated around the cell wall. (author)

  6. MinION nanopore sequencing identifies the position and structure of a bacterial antibiotic resistance island.

    Science.gov (United States)

    Ashton, Philip M; Nair, Satheesh; Dallman, Tim; Rubino, Salvatore; Rabsch, Wolfgang; Mwaigwisya, Solomon; Wain, John; O'Grady, Justin

    2015-03-01

    Short-read, high-throughput sequencing technology cannot identify the chromosomal position of repetitive insertion sequences that typically flank horizontally acquired genes such as bacterial virulence genes and antibiotic resistance genes. The MinION nanopore sequencer can produce long sequencing reads on a device similar in size to a USB memory stick. Here we apply a MinION sequencer to resolve the structure and chromosomal insertion site of a composite antibiotic resistance island in Salmonella Typhi Haplotype 58. Nanopore sequencing data from a single 18-h run was used to create a scaffold for an assembly generated from short-read Illumina data. Our results demonstrate the potential of the MinION device in clinical laboratories to fully characterize the epidemic spread of bacterial pathogens. PMID:25485618

  7. Adverse Reactions of Ferric Carboxymaltose

    OpenAIRE

    Thanusubramanian, Harish; Patil, Navin; Shenoy, Smita; Bairy, K. L.; Sarma, Yashdeep

    2014-01-01

    The author reports a 55-year-old female diagnosed of chronic kidney disease grade-5 with associated co-morbidities like type 2 diabetes mellitus, diabetic retinopathy and hypothyroidism was admitted for arteriovenous fistula construction. She was started on ferric carboxymaltose for the treatment of anaemia. She was given a test dose before administering the drug intravenously and she did not develop any reaction. The drug ferric carboxymaltose was then administered over a period of one hour....

  8. Mutagenic effect of accelerated heavy ions on bacterial cells

    Science.gov (United States)

    Boreyko, A. V.; Krasavin, E. A.

    2011-11-01

    The heavy ion accelerators of the Joint Institute for Nuclear Research were used to study the regularities and mechanisms of formation of different types of mutations in prokaryote cells. The induction of direct (lac-, ton B-, col B) mutations for Esherichia coli cells and reverse his- → His+ mutations of Salmonella typhimurium, Bacillus subtilis cells under the action of radiation in a wide range of linear energy transfer (LET) was studied. The regularities of formation of gene and structural (tonB trp-) mutations for Esherichia coli bacteria under the action of accelerated heavy ions were studied. It was demonstrated that the rate of gene mutations as a function of the dose under the action of Γ rays and accelerated heavy ions is described by linear-quadratic functions. For structural mutations, linear "dose-effect" dependences are typical. The quadratic character of mutagenesis dose curves is determined by the "interaction" of two independent "hitting" events in the course of SOS repair of genetic structures. The conclusion made was that gene mutations under the action of accelerated heavy ions are induced by δ electron regions of charged particle tracks. The methods of SOS chromotest, SOS lux test, and λ prophage induction were used to study the regularities of SOS response of cells under the action of radiations in a wide LET range. The following proposition was substantiated: the molecular basis for formation of gene mutations are cluster single-strand DNA breaks, and that for structural mutations, double-strand DNA breaks. It was found out that the LET dependence of the relative biological efficiency of accelerated ions is described by curves with a local maximum. It was demonstrated that the biological efficiency of ionizing radiations with different physical characteristics on cells with different genotype, estimated by the lethal action, induction of gene and deletion mutations, precision excision of transposons, is determined by the specific

  9. Degradation and bacterial survival on nuclear-grade ion exchange resins and implications for waste management

    International Nuclear Information System (INIS)

    Ion-exchange resins are used, among others, for the purification of the moderator of CANDU reactors. The resins are potentially degraded during service due to peroxide and temperature. The resins containing radioactive impurities collected during service are eventually discarded in non-sterile holding tanks or shipping liners, awaiting permanent disposal. In this study, we have investigated the impacts of bacterial survival on resins. We developed protocols to gently degrade resins, simulating damage during service. Resins were then contacted with bacteria. We found that, even though the resins were previously damaged, the impact of bacterial growth on resins (damaged or undamaged) was minimal. (author)

  10. Mathematical Models of Cobalt and Iron Ions Catalyzed Microwave Bacterial Deactivation

    Directory of Open Access Journals (Sweden)

    Arthur L. Williams

    2007-09-01

    Full Text Available Time differences for Enterococcus faecalis, Staphylococcus aureus, and Escherichia coli survival during microwave irradiation (power 130 W in the presence of aqueous cobalt and iron ions were investigated. Measured dependencies had "bell" shape forms with maximum bacterial viability between 1 - 2 min becoming insignificant at 3 minutes. The deactivation time for E. faecalis, S. aureus and E.coli in the presence of metal ions were smaller compared to a water control (4 -5 min. Although various sensitivities to the metal ions were observed, S. aureus and E. coli and were the most sensitive for cobalt and iron, respectively. The rapid reduction of viable bacteria during microwave treatment in the presence of metal ions could be explained by increased metal ion penetration into bacteria. Additionally, microwave irradiation may have increased the kinetic energy of the metal ions resulting in lower survival rates. The proposed mathematical model for microwave heating took into account the "growth" and "death" factors of the bacteria, forming second degree polynomial functions. Good relationships were found between the proposed mathematical models and the experimental data for bacterial deactivation (coefficient of correlation 0.91 - 0.99.

  11. Turn-off fluorescence sensor for the detection of ferric ion in water using green synthesized N-doped carbon dots and its bio-imaging.

    Science.gov (United States)

    Edison, Thomas Nesakumar Jebakumar Immanuel; Atchudan, Raji; Shim, Jae-Jin; Kalimuthu, Senthilkumar; Ahn, Byeong-Cheol; Lee, Yong Rok

    2016-05-01

    This paper reports turn-off fluorescence sensor for Fe(3+) ion in water using fluorescent N-doped carbon dots as a probe. A simple and efficient hydrothermal carbonization of Prunus avium fruit extract for the synthesis of fluorescent nitrogen-doped carbon dots (N-CDs) is described. This green approach proceeds quickly and provides good quality N-CDs. The mean size of synthesized N-CDs was approximately 7nm calculated from the high-resolution transmission electron microscopic images. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy revealed the presence of -OH, -NH2, -COOH, and -CO functional groups over the surface of CDs. The N-CDs showed excellent fluorescent properties, and emitted blue fluorescence at 411nm upon excitation at 310nm. The calculated quantum yield of the synthesized N-CDs is 13% against quinine sulfate as a reference fluorophore. The synthesized N-CDs were used as a fluorescent probe towards the selective and sensitive detection of biologically important Fe(3+) ions in water by fluorescence spectroscopy and for bio-imaging of MDA-MB-231 cells. The limit of detection (LOD) and the Stern-Volmer quenching constant for the synthesized N-CDs were 0.96μM and 2.0958×10(3)M of Fe(3+) ions. The green synthesized N-CDs are efficiently used as a promising candidate for the detection of Fe(3+) ions and bio-imaging. PMID:26994332

  12. Resolution of ion translocating proteolipid subclasses active in bacterial calcification

    International Nuclear Information System (INIS)

    Formation of calcium hydroxyapatite occurs on membrane surfaces via interaction of calcium, inorganic phosphate, phospholipids, calcifiable proteolipids, and ion flux to and from the nucleating site. Recently, this laboratory reported that proteolipids from the calcifying bacterium, Bacterionema matruchotti, act as an ionophore when reconstituted into bacteriorhodopsin-proteoliposomes. This ionophoric activity is blocked by [14C]dicyclohexylcarbodiimide ([14C]DCCD). SDS-PAGE shows that [14C]DCCD binds to a single band of Mr 8500. To determine whether proteins other than the [14C]DCCD-binding protein are involved, we examined the function of proteolipid species extracted by solvents of differing polarity. Proteolipids were isolated independently from chloroform:methanol (2:1) and chloroform:methanol:HCl (200:100:1) extracts of the bacteria by Sephadex LH-20 chromatography and were electrophoresed on 12.5% acrylamide gels. The chloroform:methanol extract contained a major hand at Mr 10,000 that was not present in gels of proteolipid isolated by acidified solvent. Proteolipids extracted in chloroform:methanol:HCl included a broad band at Mr 8500, which co-migrated with the [14C] DCCD-binding protein. The rate and extent of proton translocation were not altered when either proteolipid extract was added individually to bacteriorhodopsin proteoliposomes. However, when proteolipids isolated from the chloroform:methanol and chloroform:methanol:HCl extracts were combined, the rate and extent of translocation were increased. These data demonstrate that at least two proteolipid proteins are necessary for ionophoric activity, the Mr 10,000 protein isolated by chloroform:methanol 2:1 and the [14C]DCCD-binding protein requiring acidified solvent for extraction

  13. Bottom-up electrochemical preparation of solid-state carbon nanodots directly from nitriles/ionic liquids using carbon-free electrodes and the applications in specific ferric ion detection and cell imaging.

    Science.gov (United States)

    Niu, Fushuang; Xu, Yuanhong; Liu, Mengli; Sun, Jing; Guo, Pengran; Liu, Jingquan

    2016-03-14

    Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often required. Herein, solid-state C-dots were simply prepared by bottom-up EC carbonization of nitriles (e.g. acetonitrile) in the presence of an ionic liquid [e.g. 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6)], using carbon-free electrodes. Due to the positive charges of BMIM(+) on the C-dots, the final products presented in a precipitate form on the cathode, and the unreacted nitriles and BMIMPF6 can be easily removed by simple vacuum filtration. The as-prepared solid-state C-dots can be well dispersed in an aqueous medium with excellent photoluminescence properties. The average size of the C-dots was found to be 3.02 ± 0.12 nm as evidenced by transmission electron microscopy. Other techniques such as UV-vis spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were applied for the characterization of the C-dots and to analyze the possible generation mechanism. These C-dots have been successfully applied in efficient cell imaging and specific ferric ion detection. PMID:26891173

  14. Absorption by Isolated Ferric Heme Nitrosyl Cations In Vacuo

    DEFF Research Database (Denmark)

    Wyer, Jean; Nielsen, Steen Brøndsted

    2012-01-01

    Keywords:biophysics;gas-phase spectroscopy;heme proteins;mass spectrometry;nitric oxide Almost innocent: In photobiophysical studies of ferric heme nitrosyl complexes, the absorption spectra of six-coordinate complexes with NO and Met or Cys are similar to that of the five-coordinate complex ion Fe(heme...

  15. Ligand Induced Spin Crossover in Penta-Coordinated Ferric Dithiocarbamates

    Science.gov (United States)

    Ganguli, P.; Iyer, R. M.

    1981-09-01

    On addition of lewis bases to Fe(dtc)2X, ligand exchange takes place through a SN2 mechanism, with a parallel spin crossover in the ferric ion. The two species (S = 3/2 and S = 5/2) formed are in dynamic chemical equilibrium, and a slow decomposition is then initiated.

  16. CU(II): catalyzed hydrazine reduction of ferric nitrate

    International Nuclear Information System (INIS)

    A method is described for producing ferrous nitrate solutions by the cupric ion-catalyzed reduction of ferric nitrate with hydrazine. The reaction is complete in about 1.5 hours at 400C. Hydrazoic acid is also produced in substantial quantities as a reaction byproduct

  17. Sodium Ion Cycle in Bacterial Pathogens: Evidence from Cross-Genome Comparisons

    OpenAIRE

    Häse, Claudia C.; Fedorova, Natalie D.; Galperin, Michael Y.; Dibrov, Pavel A.

    2001-01-01

    Analysis of the bacterial genome sequences shows that many human and animal pathogens encode primary membrane Na+ pumps, Na+-transporting dicarboxylate decarboxylases or Na+-translocating NADH:ubiquinone oxidoreductase, and a number of Na+-dependent permeases. This indicates that these bacteria can utilize Na+ as a coupling ion instead of or in addition to the H+ cycle. This capability to use a Na+ cycle might be an important virulence factor for such pathogens as Vibrio cholerae, Neisseria m...

  18. Ion Conductivity of the Bacterial Translocation Channel SecYEG Engaged in Translocation*

    OpenAIRE

    Knyazev, Denis G.; Winter, Lukas; Bauer, Benedikt W.; Siligan, Christine; Pohl, Peter

    2014-01-01

    While engaged in protein transport, the bacterial translocon SecYEG must maintain the membrane barrier to small ions. The preservation of the proton motif force was attributed to (i) cation exclusion, (ii) engulfment of the nascent chain by the hydrophobic pore ring, and (iii) a half-helix partly plugging the channel. In contrast, we show here that preservation of the proton motif force is due to a voltage-driven conformational change. Preprotein or signal peptide binding to the purified and ...

  19. Ion Selectivity Mechanism in a Bacterial Pentameric Ligand-Gated Ion Channel

    International Nuclear Information System (INIS)

    The proton-gated ion channel from Gloeobacter violaceus (GLIC) is a prokaryotic homolog of the eukaryotic nicotinic acetylcholine receptor that responds to the binding of neurotransmitter acetylcholine and mediates fast signal transmission. Recent emergence of a high-resolution crystal structure of GLIC captured in a potentially open state allowed detailed, atomic-level insight into ion conduction and selectivity mechanisms in these channels. Herein, we have examined the barriers to ion conduction and origins of ion selectivity in the GLIC channel by the construction of potential-of-mean-force profiles for sodium and chloride ions inside the transmembrane region. Our calculations reveal that the GLIC channel is open for a sodium ion to transport, but presents a 11 kcal/mol free energy barrier for a chloride ion. Our collective findings identify three distinct contributions to the observed preference for the permeant ions. First, there is a substantial contribution due to a ring of negatively charged glutamate residues (E-2 ) at the narrow intracellular end of the channel. The negative electrostatics of this region and the ability of the glutamate side chains to directly bind cations would strongly favor the passage of sodium ions while hindering translocation of chloride ions. Second, our results imply a significant hydrophobic contribution to selectivity linked to differences in the desolvation penalty for the sodium versus chloride ions in the central hydrophobic region of the pore. This hydrophobic contribution is evidenced by the large free energy barriers experienced by Cl in the middle of the pore for both GLIC and the E-2 A mutant. Finally, there is a distinct contribution arising from the overall negative electrostatics of the channel.

  20. Gas-phase spectroscopy of ferric heme-NO complexes

    DEFF Research Database (Denmark)

    Wyer, J.A.; Jørgensen, Anders; Pedersen, Bjarke;

    2013-01-01

    Weakly bound complexes between ferric heme cations and NO were synthesised in the gas phase from ion-molecule reactions, and their absorption measured based on photodissociation yields. The Soret band, which serves as an important marker band for heme-protein spectroscopy, is maximal at 357±5 nm...... and significantly blue-shifted compared to ferric heme nitrosyl proteins (maxima between 408 and 422 nm). This is in stark contrast to the Q-band absorption where the protein microenvironment is nearly innocent in perturbing the electronic structure of the porphyrin macrocycle. Photodissociation is...... absorption maxima of heme and its complexes with amino acids and NO. Not so innocent: Weakly bound complexes between ferric heme and NO were synthesised in the gas phase, and their absorption measured from photodissociation yields. Opposite absorption trends in the Soret-band are seen upon NO addition to...

  1. Synthesis of nitrogen-doped and amino acid-functionalized graphene quantum dots from glycine, and their application to the fluorometric determination of ferric ion

    International Nuclear Information System (INIS)

    We report on a single-step thermolysis strategy to prepare highly luminescent nitrogen-doped and amino acid-functionalized graphene quantum dots (NA-GQDs) by using glycine as both carbon and nitrogen source. The NA-GQDs display an excitation wavelength-dependent fluorescence with maximum excitation and emission wavelengths of 380 and 450 nm, respectively, and a quantum yield of ∼16 %. Fluorescence is quenched by Fe(III) and Hg(II), and the effect was used to develop a method for the determination of Fe(III). Quenching by Fe(III) is attributed to its higher thermodynamic affinity (compared to other transition-metal ions) for the ligands on the GQDs in which nitrogen atoms mainly act as the chelating atoms. A linear relationship was observed between fluorescence intensity and the concentration of Fe(III) over the 0.5 μM to 0.5 mM range. The detection limit is 0.1 μM. (author)

  2. 21 CFR 184.1301 - Ferric phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferric phosphate. 184.1301 Section 184.1301 Food... Specific Substances Affirmed as GRAS § 184.1301 Ferric phosphate. (a) Ferric phosphate (ferric orthophosphate, iron (III) phosphate, FePO4·xH2O, CAS Reg. No. 10045-86-0) is an odorless, yellowish-white...

  3. Bottom-up electrochemical preparation of solid-state carbon nanodots directly from nitriles/ionic liquids using carbon-free electrodes and the applications in specific ferric ion detection and cell imaging

    Science.gov (United States)

    Niu, Fushuang; Xu, Yuanhong; Liu, Mengli; Sun, Jing; Guo, Pengran; Liu, Jingquan

    2016-03-01

    Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often required. Herein, solid-state C-dots were simply prepared by bottom-up EC carbonization of nitriles (e.g. acetonitrile) in the presence of an ionic liquid [e.g. 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6)], using carbon-free electrodes. Due to the positive charges of BMIM+ on the C-dots, the final products presented in a precipitate form on the cathode, and the unreacted nitriles and BMIMPF6 can be easily removed by simple vacuum filtration. The as-prepared solid-state C-dots can be well dispersed in an aqueous medium with excellent photoluminescence properties. The average size of the C-dots was found to be 3.02 +/- 0.12 nm as evidenced by transmission electron microscopy. Other techniques such as UV-vis spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were applied for the characterization of the C-dots and to analyze the possible generation mechanism. These C-dots have been successfully applied in efficient cell imaging and specific ferric ion detection.Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often

  4. 21 CFR 582.5301 - Ferric phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ferric phosphate. 582.5301 Section 582.5301 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5301 Ferric phosphate. (a) Product. Ferric phosphate. (b) Conditions of use....

  5. Bacterial cellulose nanofibrous membrane as thermal stable separator for lithium-ion batteries

    Science.gov (United States)

    Jiang, Fengjing; Yin, Lei; Yu, Qingchun; Zhong, Chunyan; Zhang, Junliang

    2015-04-01

    Thermal shrinkage is a severe problem for the conventional polyolefin separators. In this work, we report the excellent performance of bacterial cellulose (BC) nanofibrous membranes as separators for lithium (Li) ion batteries. Properties of BC separator including morphology, ionic conductivity, electrochemical stability, thermal stability, mechanical strength and battery charge-discharge performance are characterized and compared to a commercial separator membrane (Celgard® 2325). Because of the unique fibrous and cross-linked three-dimensional network structure, BC separator shows excellent dimensional stability up to 180 °C, good ionic conductivity and competitive battery performance.

  6. Adverse reactions of ferric carboxymaltose.

    Science.gov (United States)

    Thanusubramanian, Harish; Patil, Navin; Shenoy, Smita; Bairy, K L; Sarma, Yashdeep

    2014-10-01

    The author reports a 55-year-old female diagnosed of chronic kidney disease grade-5 with associated co-morbidities like type 2 diabetes mellitus, diabetic retinopathy and hypothyroidism was admitted for arteriovenous fistula construction. She was started on ferric carboxymaltose for the treatment of anaemia. She was given a test dose before administering the drug intravenously and she did not develop any reaction. The drug ferric carboxymaltose was then administered over a period of one hour. About half an hour after drug administration, the patient developed breathlessness and myalgia. After half hour of the above episode of breathlessness and myalgia she also developed vomiting (one episode). Patient was managed with oxygen therapy, IV fluids and other drugs like corticosteroids, phenaramine maleate and nalbuphine which controlled the above symptoms. PMID:25478369

  7. Ion conductivity of the bacterial translocation channel SecYEG engaged in translocation.

    Science.gov (United States)

    Knyazev, Denis G; Winter, Lukas; Bauer, Benedikt W; Siligan, Christine; Pohl, Peter

    2014-08-29

    While engaged in protein transport, the bacterial translocon SecYEG must maintain the membrane barrier to small ions. The preservation of the proton motif force was attributed to (i) cation exclusion, (ii) engulfment of the nascent chain by the hydrophobic pore ring, and (iii) a half-helix partly plugging the channel. In contrast, we show here that preservation of the proton motif force is due to a voltage-driven conformational change. Preprotein or signal peptide binding to the purified and reconstituted SecYEG results in large cation and anion conductivities only when the membrane potential is small. Physiological values of membrane potential close the activated channel. This voltage-dependent closure is not dependent on the presence of the plug domain and is not affected by mutation of 3 of the 6 constriction residues to glycines. Cellular ion homeostasis is not challenged by the small remaining leak conductance. PMID:25016015

  8. Ion Conductivity of the Bacterial Translocation Channel SecYEG Engaged in Translocation*

    Science.gov (United States)

    Knyazev, Denis G.; Winter, Lukas; Bauer, Benedikt W.; Siligan, Christine; Pohl, Peter

    2014-01-01

    While engaged in protein transport, the bacterial translocon SecYEG must maintain the membrane barrier to small ions. The preservation of the proton motif force was attributed to (i) cation exclusion, (ii) engulfment of the nascent chain by the hydrophobic pore ring, and (iii) a half-helix partly plugging the channel. In contrast, we show here that preservation of the proton motif force is due to a voltage-driven conformational change. Preprotein or signal peptide binding to the purified and reconstituted SecYEG results in large cation and anion conductivities only when the membrane potential is small. Physiological values of membrane potential close the activated channel. This voltage-dependent closure is not dependent on the presence of the plug domain and is not affected by mutation of 3 of the 6 constriction residues to glycines. Cellular ion homeostasis is not challenged by the small remaining leak conductance. PMID:25016015

  9. A novel type bacterial flagellar motor that can use divalent cations as a coupling ion.

    Science.gov (United States)

    Imazawa, Riku; Takahashi, Yuka; Aoki, Wataru; Sano, Motohiko; Ito, Masahiro

    2016-01-01

    The bacterial flagellar motor is a sophisticated nanomachine embedded in the cell envelope and powered by an electrochemical gradient of H(+), Na(+), or K(+)across the cytoplasmic membrane. Here we describe a new member of the bacterial flagellar stator channel family (MotAB1 of Paenibacillus sp. TCA20 (TCA-MotAB1)) that is coupled to divalent cations (Ca(2+)and Mg(2+)). In the absence of divalent cations of alkaline earth metals, no swimming was observed in Paenibacillus sp. TCA20, which grows optimally in Ca(2+)-rich environments. This pattern was confirmed by swimming assays of a stator-free Bacillus subtilis mutant expressing TCA-MotAB1. Both a stator-free and major Mg(2+)uptake system-deleted B. subtilis mutant expressing TCA-MotAB1 complemented both growth and motility deficiency under low Mg(2+)conditions and exhibited [Mg(2+)]in identical to that of the wild-type. This is the first report of a flagellar motor that can use Ca(2+)and Mg(2+)as coupling ions. These findings will promote the understanding of the operating principles of flagellar motors and molecular mechanisms of ion selectivity. PMID:26794857

  10. Effect of negative air ions on the potential for bacterial contamination of plastic medical equipment

    Directory of Open Access Journals (Sweden)

    Kerr Kevin G

    2010-04-01

    Full Text Available Abstract Background In recent years there has been renewed interest in the use of air ionizers to control the spread of infection in hospitals and a number of researchers have investigated the biocidal action of ions in both air and nitrogen. By comparison, the physical action of air ions on bacterial dissemination and deposition has largely been ignored. However, there is clinical evidence that air ions might play an important role in preventing the transmission of Acinetobacter infection. Although the reasons for this are unclear, it is hypothesized that a physical effect may be responsible: the production of air ions may negatively charge items of plastic medical equipment so that they repel, rather than attract, airborne bacteria. By negatively charging both particles in the air and items of plastic equipment, the ionizers minimize electrostatic deposition on these items. In so doing they may help to interrupt the transmission of Acinetobacter infection in certain healthcare settings such as intensive care units. Methods A study was undertaken in a mechanically ventilated room under ambient conditions to accurately measure changes in surface potential exhibited by items of plastic medical equipment in the presence of negative air ions. Plastic items were suspended on nylon threads, either in free space or in contact with a table surface, and exposed to negative ions produced by an air ionizer. The charge build-up on the specimens was measured using an electric field mill while the ion concentration in the room air was recorded using a portable ion counter. Results The results of the study demonstrated that common items of equipment such as ventilator tubes rapidly developed a large negative charge (i.e. generally >-100V in the presence of a negative air ionizer. While most items of equipment tested behaved in a similar manner to this, one item, a box from a urological collection and monitoring system (the only item made from styrene

  11. Selective adsorption of phosphoproteins on gel-immobilized ferric chelate

    International Nuclear Information System (INIS)

    Ferric ions are very strongly adsorbed to iminodiacetic acid substituted agarose. This firmly immobilized complex acts as a selective immobilized metal affinity adsorbent for phosphoproteins. Chromatography based on this principle is illustrated by the adsorption-desorption behavior of egg yolk phosvitin before and after dephosphorylation as well as by the change in the chromatographic pattern before and after enzymic phosphorylation of selected histones. The strength of binding is dependent on the phosphate content. The difference is binding before and after phosphorylation of a single amino acid residue is demonstrated. Affinity elution can be accomplished by inclusion in the buffer of (1) phosphoserine or (2) a displacing metal ion such as Mg2+

  12. Freestanding bacterial cellulose-graphene oxide composite membranes with high mechanical strength for selective ion permeation.

    Science.gov (United States)

    Fang, Qile; Zhou, Xufeng; Deng, Wei; Zheng, Zhi; Liu, Zhaoping

    2016-01-01

    Graphene oxide (GO) based membranes have been widely applied in molecular separation based on the size exclusion effect of the nanochannels formed by stacked GO sheets. However, it's still a challenge to prepare a freestanding GO-based membrane with high mechanical strength and structural stability which is prerequisite for separation application in aqueous solution. Here, a freestanding composite membrane based on bacterial cellulose (BC) and GO is designed and prepared. BC network provides a porous skeleton to spread GO sheets and uniformly incorporates into the GO layers, which endows the BC + GO composite membrane with well water-stability, excellent tensile strength, as well as improved toughness, guaranteeing its separation applicability in water environment. The resulting BC + GO membrane exhibits obviously discrepant permeation properties for different inorganic/organic ions with different size, and in particular, it can quickly separate ions in nano-scale from angstrom-scale. Therefore, this novel composite membrane is considered to be a promising candidate in the applications of water purification, food industry, biomedicine, and pharmaceutical and fuel separation. PMID:27615451

  13. Binding Properties of Bismuth Coordination Compounds to the Ferric-Ion Binding Protein from Neisseria gonorrhoeae%含铋配合物与奈瑟氏菌铁结合蛋白的反应性质研究

    Institute of Scientific and Technical Information of China (English)

    曾旭; 叶丹荣; 林德昌; 江海龙; 李敏; 罗俊; 仲维清

    2011-01-01

    Ferric-ion binding protein (Fbp) plays a key role for capturing Fe3+ in pathogenic bacteria. Here, BiNTA·2H2O was syntheisized by reacting nitrilotriacetatic acid (H3NTA) with Bi(NO3)3 and characterized by element analysis and NMR spectroscopy. Fbp of Neisseria gonorrhoeae was expressed in E. Coli, and isolated and purified. The dynamics of the reaction of BiNTA with apo-Fbp was determined by UV-Vis spectroscopy at different ratio of nB6NTA/napo-Fbp.The reaction follows first-order mechanism and the rate constant is (0.175 ±0.064) min-1 (in 10 mmol·L-1 Hepes/HPO42- buffer at pH 7.4 and 310 K). The similar kinetics and rate constant were observed for the reaction of NH4BiCit with apo-Fbp. Bi3+ can bind to apo-Fbp at 1:1 molar ratio, and the binding constant lgK is (21.43±0.20) for Fbp-Bi-NTA and (16.03±0.03) for Fbp-Bi-Cit, respectively. These results indicate that the Feu transfer protein Fbp in pathogens could be the potential target for the bismuth antibacterial drugs.%铁结合蛋白(Fbp)是致病菌获取Fe3+的关键蛋白.本文采用氨三乙酸(H3NTA)和硝酸铋反应制备BiNTA·2H2O,并运用元素分析、NMR等手段进行表征.通过在大肠杆菌中克隆表达和分离纯化出奈瑟氏淋病双球菌的Fbp,测定不同计量比nSiNTA/n apo-Fbp下反应的紫外可见光谱,确定BiNTA与apo-Fbp的反应为一级反应,反应速率常数约为(0.175-0.064) min-1(10 mmol· L-1 Hepes/HPO42- pH 7.4缓冲溶液,310K).NH4BiCit与apo-Fbp的反应也为一级反应,反应速率与BiNTA相近.Bi3+ apo-Fbp的饱和结合计量比为1∶1,形成三元配合物Fbp-Bi-NTA的结合常数(lgK)为(21.43±0.20),形成Fbp-Bi-Cit的结合常数(lgK)为(16.03±0.03).实验结果表明,致病菌中运输Fe3+的蛋白铁结合蛋白可作为含铋抗菌药物的潜在靶分子.

  14. Two Bifunctional Enzymes with Ferric Reduction Ability Play Complementary Roles during Magnetosome Synthesis in Magnetospirillum gryphiswaldense MSR-1

    OpenAIRE

    Zhang, Chan; Meng, Xia; Li, Ningxiao; Wang, Wei; Sun, Yuan; Jiang, Wei; Guan, Guohua; Ying LI

    2013-01-01

    The bacterial strain Magnetospirillum gryphiswaldense MSR-1 does not produce siderophores, but it absorbs a large amount of ferric iron and synthesizes magnetosomes. We demonstrated previously the presence of six types of ferric reductase isozymes (termed FeR1 through FeR6) in MSR-1. Of these isozymes, FeR5 was the most abundant and FeR6 showed the highest ferric reductase activity. In the present study, we cloned the fer5 and fer6 genes from MSR-1 and expressed them separately in Escherichia...

  15. A mathematical model for the bacterial oxidation of a sulfide ore concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, S.; Dahlstrom, D. (Univ. of Utah, Salt Lake City, UT (United States). Dept. of Chemical Engineering); Oolman, T. (Radian Corp., Austin, TX (United States))

    1994-03-05

    The effect of dilution rate and feed solids concentration on the bacterial leaching of a pyrite/arsenopyrite ore concentrate was studied. A mathematical model was developed for the process based on the steady-state data collected over the range of dilution rates (20 to 110 h) and feed solids concentrations (6 to 18% w/v) studied. A modified Monod model with inhibition by arsenic was used to model bacterial ferrous ion oxidation rates. The model assumes that (1) pyrite and arsenopyrite leaching occurs solely by the action of ferric iron produced from the bacterial oxidation of ferrous iron and (2) bacterial growth rates are proportional to ferrous ion oxidation rate. The equilibrium among the various ionic species present in the leach solution that are likely to have a significant effect on the bioleach process were included in the model.

  16. Hydrolysis of ferric chloride in solution

    International Nuclear Information System (INIS)

    The Detox trademark process uses concentrated ferric chloride and small amounts of catalysts to oxidize organic compounds. It is under consideration for oxidizing transuranic organic wastes. Although the solution is reused extensively, at some point it will reach the acceptable limit of radioactivity or maximum solubility of the radioisotopes. This solution could be cemented, but the volume would be increased substantially because of the poor compatibility of chlorides and cement. A process has been developed that recovers the chloride ions as HCl and either minimizes the volume of radioactive waste or permits recycling of the radioactive chlorides. The process involves a two-step hydrolysis at atmospheric pressure, or preferably under a slight vacuum, and relatively low temperature, about 200 degrees C. During the first step of the process, hydrolysis occurs according to the reaction below: FeCl3liquid + H2O → FeOClsolid + 2 HClgas During the second step, the hot, solid, iron oxychloride is sprayed with water or placed in contact with steam, and hydrolysis proceeds to the iron oxide according to the following reaction: 2 FeOClsolid + H2O → Fe2O3solid + 2 HClgas. The iron oxide, which contains radioisotopes, can then be disposed of by cementation or encapsulation. Alternately, these chlorides can be washed off of the solids and can then either be recycled or disposed of in some other way

  17. In vivo NMR study of yeast fermentative metabolism in the presence of ferric irons

    Indian Academy of Sciences (India)

    Maso Ricci; Silvia Martini; Claudia Bonechi; Daniela Braconi; Annalisa Santucci; Claudio Rossi

    2011-03-01

    Mathematical modelling analysis of experimental data, obtained with in vivo NMR spectroscopy and 13C-labelled substrates, allowed us to describe how the fermentative metabolism in Saccharomyces cerevisiae, taken as eukaryotic cell model, is influenced by stress factors. Experiments on cellular cultures subject to increasing concentrations of ferric ions were conducted in order to study the effect of oxidative stress on the dynamics of the fermentative process. The developed mathematical model was able to simulate the cellular activity, the metabolic yield and the main metabolic fluxes occurring during fermentation and to describe how these are modulated by the presence of ferric ions.

  18. In vivo NMR study of yeast fermentative metabolism in the presence of ferric irons.

    Science.gov (United States)

    Ricci, Maso; Martini, Silvia; Bonechi, Claudia; Braconi, Daniela; Santucci, Annalisa; Rossi, Claudio

    2011-03-01

    Mathematical modelling analysis of experimental data, obtained with in vivo NMR spectroscopy and 13C-labelled substrates, allowed us to describe how the fermentative metabolism in Saccharomyces cerevisiae, taken as eukaryotic cell model, is influenced by stress factors. Experiments on cellular cultures subject to increasing concentrations of ferric ions were conducted in order to study the effect of oxidative stress on the dynamics of the fermentative process. The developed mathematical model was able to simulate the cellular activity, the metabolic yield and the main metabolic fluxes occurring during fermentation and to describe how these are modulated by the presence of ferric ions. PMID:21451251

  19. Ferric Iron Reduction by Acidophilic Heterotrophic Bacteria

    OpenAIRE

    Johnson, D. Barrie; McGinness, Stephen

    1991-01-01

    Fifty mesophilic and five moderately thermophilic strains of acidophilic heterotrophic bacteria were tested for the ability to reduce ferric iron in liquid and solid media under aerobic conditions; about 40% of the mesophiles (but none of the moderate thermophiles) displayed at least some capacity to reduce iron. Both rates and extents of ferric iron reduction were highly strain dependent. No acidophilic heterotroph reduced nitrate or sulfate, and (limited) reduction of manganese(IV) was note...

  20. Mercuric ion reduction and resistance in transgenic Arabidopsis thaliana plants expressing a modified bacterial merA gene.

    OpenAIRE

    Rugh, C L; Wilde, H D; Stack, N M; Thompson, D. M.; Summers, A O; Meagher, R B

    1996-01-01

    With global heavy metal contamination increasing, plants that can process heavy metals might provide efficient and ecologically sound approaches to sequestration and removal. Mercuric ion reductase, MerA, converts toxic Hg2+ to the less toxic, relatively inert metallic mercury (Hg0) The bacterial merA sequence is rich in CpG dinucleotides and has a highly skewed codon usage, both of which are particularly unfavorable to efficient expression in plants. We constructed a mutagenized merA sequenc...

  1. Ferric Oxide from Hematite Used in Microwave Ferrite Material

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Ferric Oxide is an essential and raw material in the production of ferrite materials. At present, ferric oxide used by many domestic factories is mainly produced by chemical method. In this paper, we use ferric oxide refined from hematite and applied in the microwave ferrite material production test. Compared with the normal ferric oxide, we get the same or similar results. It shows that ferric oxide from hematite and applied in the microwave ferrite material production test. Compared with the normal ferric oxide, we get the same or similar results. It shows that ferric oxide from hematite has a bright application prospect.

  2. Colour and stability assessment of blue ferric anthocyanin chelates in liquid pectin-stabilised model systems.

    Science.gov (United States)

    Buchweitz, M; Brauch, J; Carle, R; Kammerer, D R

    2013-06-01

    The formation of blue coloured ferric anthocyanin chelates and their colour stability during storage and thermal treatment were monitored in a pH range relevant to food (3.6-5.0). Liquid model systems were composed of different types of Citrus pectins, juices (J) and the respective phenolic extracts (E) from elderberry (EB), black currant (BC), red cabbage (RC) and purple carrot (PC) in the presence of ferric ions. For EB, BC and PC, pure blue colours devoid of a violet tint were exclusively observed for the phenolic extracts and at pH values ≥ 4.5 in model systems containing high methoxylated and amidated pectins, respectively. Colour and its stability strongly depended on the amount of ferric ions and the plant source; however, colour decay could generally be described as a pseudo-first-order kinetics. Despite optimal colour hues for RC-E and RC-J, storage and heat stabilities were poor. Highest colour intensities and best stabilities were observed for model systems containing PC-E at a molar anthocyanin:ferric ion ratio of 1:2. Ascorbic and lactic acids interfered with ferric ions, thus significantly affecting blue colour evolution and stability. Colour loss strongly depended on heat exposure with activation energies ranging between 60.5 and 78.4 kJ/mol. The comprehensive evaluation of the interrelationship of pigment source, pH conditions and pectin type on chelate formation and stability demonstrated that ferric anthocyanin chelates are promising natural blue food colourants. PMID:23411339

  3. Preparation of ferric acetylacetonate, bonzonate and caprate labelled with Fe-55 and tests of application to liquid scintillation measurements

    International Nuclear Information System (INIS)

    The methods of preparation of ferric acetylacetonate, benzoate and caprate labelled with 55Fe are described. The quenching effect, the spectral baehaviour and the count rate stability are studied by liquid scintillation measurements in toluene, INSTAGEL and HISAFE II, for two different values of the sample concentration. The ferric acetylaceton-ate is stable for all the three scintillators but shows a strong quench, while the ferric benzoate and caprate are stable only for INSTAGEL and HISAFE II showing no significant quench at the concentrat-ions of interest in habitual measurements. (Author)

  4. Hydrolysis of ferric chloride in solution

    Energy Technology Data Exchange (ETDEWEB)

    Lussiez, G.; Beckstead, L.

    1996-11-01

    The Detox{trademark} process uses concentrated ferric chloride and small amounts of catalysts to oxidize organic compounds. It is under consideration for oxidizing transuranic organic wastes. Although the solution is reused extensively, at some point it will reach the acceptable limit of radioactivity or maximum solubility of the radioisotopes. This solution could be cemented, but the volume would be increased substantially because of the poor compatibility of chlorides and cement. A process has been developed that recovers the chloride ions as HCl and either minimizes the volume of radioactive waste or permits recycling of the radioactive chlorides. The process involves a two-step hydrolysis at atmospheric pressure, or preferably under a slight vacuum, and relatively low temperature, about 200{degrees}C. During the first step of the process, hydrolysis occurs according to the reaction below: FeCl{sub 3 liquid} + H{sub 2}O {r_arrow} FeOCl{sub solid} + 2 HCl{sub gas} During the second step, the hot, solid, iron oxychloride is sprayed with water or placed in contact with steam, and hydrolysis proceeds to the iron oxide according to the following reaction: 2 FeOCl{sub solid} + H{sub 2}O {r_arrow} Fe{sub 2}O{sub 3 solid} + 2 HCl{sub gas}. The iron oxide, which contains radioisotopes, can then be disposed of by cementation or encapsulation. Alternately, these chlorides can be washed off of the solids and can then either be recycled or disposed of in some other way.

  5. Ferric Sulfate Leaching of Pyrrhotite Tailings between 30 to 55 °C

    Directory of Open Access Journals (Sweden)

    Nazanin Samadifard

    2015-11-01

    Full Text Available Mine tailings present major environmental issues in the mining industry. However due to the depletion of high-grade sulfide ores for metal recovery, tailings could also be a potential resource for certain valuable metals. The present study investigates the potential to recover nickel from pyrrhotite tailings. Leaching tests were performed in acidic ferric sulfate media with 0.14 wt % solids to keep the ferric concentration essentially constant. The temperature was varied between 30 and 55 °C, and the ferric concentration was in a range 0.02–0.3 M. The results showed that both temperature and ferric sulfate concentration had significant effects on the nickel extraction kinetics. The shrinking core model (SCM was applied to the nickel extraction data. The rate controlling step was found to be product layer diffusion. The Arrhenius plot yielded an activation energy of Ea = 62.12 kJ/mol based on apparent reaction rates obtained by the SCM. The reaction order with respect to ferric ion was found to be 1 at the high concentration range. SEM images of partially leached tailings confirmed the presence of elemental sulfur around the pyrrhotite particles, which was responsible for the observed non-linear leaching kinetics (diffusion control.

  6. 21 CFR 184.1304 - Ferric pyrophosphate.

    Science.gov (United States)

    2010-04-01

    ... meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 120, which is incorporated by... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferric pyrophosphate. 184.1304 Section 184.1304 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED)...

  7. The biostimulation of anaerobic digestion with (semi)conductive ferric oxides: their potential for enhanced biomethanation.

    Science.gov (United States)

    Baek, Gahyun; Kim, Jaai; Cho, Kyungjin; Bae, Hyokwan; Lee, Changsoo

    2015-12-01

    The effect of biostimulation with ferric oxides, semiconductive ferric oxyhydroxide, and conductive magnetite on the anaerobic digestion of dairy wastewater was examined in a batch mode. The reactors supplemented with ferric oxyhydroxide (R2) and magnetite (R3) showed significantly enhanced biomethanation performance compared with the control (R1). The removal of chemical oxygen demand (COD) after 30 days was 31.9, 59.3, and 82.5% in R1, R2, and R3, respectively. The consumed COD was almost fully recovered as biogas in R2 and R3, while only 79% was recovered in R1. The total energy production as biogas was accordingly 32.2, 71.0, and 97.7 kJ in R1, R2, and R3, respectively. The reactors also differed in the acid formation profile with more propionate and butyrate found in R1 and more acetate found in R3. The enhanced biomethanation seems to be associated with variations in the bacterial community structure supposedly induced by the ferric oxides added. In contrast, no evident variation was observed in the archaeal community structure among the reactors. The potential electric syntrophy formed between Methanosaeta concilii-like methanogens and electroactive iron-reducing bacteria, particularly Trichococcus, was likely responsible for the enhanced performance. The stimulated growth of fermentative iron reducers may also have contributed by altering the metabolic characteristics of the bacterial communities to produce more favorable acidogenic products for methanogenesis. The overall results suggest the potential of biostimulation with (semi)conductive ferric oxides to enhance the rate and efficiency of the biomethanation of organic wastes. This seems to be potentially attractive, as increasing attention is being paid to the energy self-sufficiency of waste/wastewater treatment processes today. PMID:26272096

  8. Electrostatic interactions in the adhesion of an ion-penetrable and ion-impenetrable bacterial strain to glass

    NARCIS (Netherlands)

    Poortinga, AT; Busscher, HJ; Bos, R.R.M.

    2001-01-01

    Deposition to glass of Streptococcus salivarius HB-C12 and Staphylococcus epidermidis 3399 in a parallel plate flow chamber has been studied as a function of ionic strength. Electrophoretic mobility measurements revealed that S. epidermidis 3399 possesses a thick ion-penetrable layer, probably assoc

  9. Analysis of bacterial communities and bacterial pathogens in a biogas plant by the combination of ethidium monoazide, PCR and Ion Torrent sequencing

    DEFF Research Database (Denmark)

    Luo, Gang; Angelidaki, Irini

    2014-01-01

    The present study investigated the changes of bacterial community composition including bacterial pathogens along a biogas plant, i.e. from the influent, to the biogas reactor and to the post-digester. The effects of post-digestion temperature and time on the changes of bacterial community...... had a significant effect on the changes of bacterial community composition. The changes of bacterial community composition were also reflected in the changes of relative abundance of bacterial pathogens. The richness and relative abundance of bacterial pathogens were reduced after anaerobic digestion...... in the biogas reactor. It was found in batch experiments that bacterial pathogens showed the highest relative abundance and richness after 30days' post-digestion. Streptococcus bovis was found in all the samples. Our results showed that special attention should be paid to the post-digestion since the...

  10. Production of ferric sulphate from pyrite by thiobacillus ferrooxidans. Application to uranium ore leaching

    International Nuclear Information System (INIS)

    A process for uranium extraction by oxidizing solutions of ferric sulphate produced by T. ferrooxidans from pyrite is developed. A new counting method specific of T. ferrooxidans is designed. An uranium resistant wild strain, with oxidizing properties as high as the strain ATCC 19859, is isolated. Optimal conditions for ferric sulphate production from pyrite are defined (pH 1.8, density of the medium 1.2%, pyrite granulometry < 60 micrometers). The comparison of oxidation of 2 pyrites evidences the effect of composition and crystal type on bacterial activity. Latency period is reduced by preliminary adaptation of bacteria to pyrite, a relatively important inoculum and association of T. ferrooxidans to T. thiooxidans. Free bacteria, but not adsorbed bacteria, play an important part in pyrite oxidation, indirectly by regeneration of ferric iron and by maintaining a high redox potential. Leaching of an uranium ore column by an acidic solution of ferric iron increase not only uranium extraction yield but also to decrease acid consumption in respect to acid leaching only

  11. Biosorption of metal ions by attached bacterial cells in a packed-bed bioreactor

    International Nuclear Information System (INIS)

    This work describes a simple method for the immobilization of a biosorbent. An adherent Bacillus sp. strain has been grown attached to an inert support material. This strain had the capacity to bind uranium, copper, cadmium and zinc. The desorption of these metals was quantitative at pH-values lower than 2. To study the attachment of the bacterial biomass, a laboratory-scale packed-bed bioreactor with an appropriate aeration system was developed. The colonization of the support was fast and efficient. In batch culture conditions, the biomass accumulation reached a cuasi-stationary phase after 12 h. Under optimal conditions, the attached biomass comprised around 80% of the total biomass present in the bioreactor. After the colonization phase, the packed-bed bioreactor was continuously operated to remove heavy metals from aqueous solutions. The biosorption capacity of the attached biomass was similar to that of the free bacterial suspension

  12. Putative resolution of the EEEE selectivity paradox in L-type Ca2+ and bacterial Na+ biological ion channels

    Science.gov (United States)

    Kaufman, I. Kh; Luchinsky, D. G.; Gibby, W. A. T.; McClintock, P. V. E.; Eisenberg, R. S.

    2016-05-01

    The highly selective permeation of ions through biological ion channels can be described and explained in terms of fluctuational dynamics under the influence of powerful electrostatic forces. Hence valence selectivity, e.g. between Ca2+ and Na+ in calcium and sodium channels, can be described in terms of ionic Coulomb blockade, which gives rise to distinct conduction bands and stop-bands as the fixed negative charge Q f at the selectivity filter of the channel is varied. This picture accounts successfully for a wide range of conduction phenomena in a diversity of ion channels. A disturbing anomaly, however, is that what appears to be the same electrostatic charge and structure (the so-called EEEE motif) seems to select Na+ conduction in bacterial channels but Ca2+ conduction in mammalian channels. As a possible resolution of this paradox it is hypothesised that an additional charged protein residue on the permeation path of the mammalian channel increases |{{Q}f}| by e, thereby altering the selectivity from Na+ to Ca2+. Experiments are proposed that will enable the hypothesis to be tested.

  13. Bacterially Induced Dolomite Formation in the Presence of Sulfate Ions under Aerobic Conditions

    Science.gov (United States)

    Sanchez-Roman, M.; McKenzie, J. A.; Vasconcelos, C.; Rivadeneyra, M.

    2005-12-01

    The origin of dolomite remains a long-standing enigma in sedimentary geology because, although thermodynamically favorable, precipitation of dolomite from modern seawater does not occur. Experiments conducted at elevated temperatures (200 oC) indicated that the presence of small concentrations of sulfate ions inhibits the transformation of calcite to dolomite [1]. Indeed, sulfate ions appeared to inhibit dolomite formation above 2 mM concentration (versus 28 mM in modern seawater). Recently, culture experiments have demonstrated that sulfate-reducing bacteria mediate the precipitation of dolomite at Earth surface conditions in the presence of sustained sulfate ion concentrations [2,3]. Additionally, in a number of modern hypersaline environments, dolomite forms from solutions with high sulfate ion concentrations (2 to 70 times seawater). These observations suggest that the experimentally observed sulfate-ion inhibition [1] may not apply to all ancient dolomite formation. Here, we report aerobic culture experiments conducted at low temperatures (25 and 35 oC) and variable sulfate ion concentrations (0, 0.5, 1 and 2 x seawater values) using moderately halophilic bacteria, Halomonas meridiana. After an incubation period of 15 days, experiments at 35 oC with variable sulfate ion concentrations (0, 0.5 x and seawater values) contained crystals of Ca-dolomite and stochiometric dolomite. The experiment at 35 oC with 2 x seawater sulfate ion concentration produced dolomite crystals after 20 days of incubation. In a parallel set of experiments at 25 oC, precipitation of dolomite was observed after 25 days of incubation in cultures with variable sulfate ion concentrations (0, 0.5 x and seawater values). In the culture with 2 x seawater sulfate ion concentration, dolomite crystals were observed after 30 days. Our study demonstrates that halophilic bacteria (or heterotrophic microorganisms), which do not require sulfate ions for metabolism, can mediate dolomite precipitation

  14. Microsecond molecular dynamics simulations of the open state structure of a bacterial voltage-gated sodium channel reveal mechanisms of ion selectivity and conduction

    OpenAIRE

    Ulmschneider, Martin B.; Bagneris, Claire; McCusker, Emily C.; Ulmschneider, J.P.; Wallace, Bonnie A.

    2013-01-01

    Microsecond atomic detail equilibrium molecular dynamics simulations based on the open-state crystal structure (McCusker et al, 2012, Nature Comm) of a bacterial voltage-gated sodium channel (NavMs) have been employed to characterize the mechanisms underlying ion selectivity and conductance of the channel embedded in a lipid bilayer membrane. This approach captured the full plethora of conduction events, revealing a complex mixture of single and multi-ion phenomena, with decoupled rapid bi-di...

  15. Composite ferric oxyhydroxide-containing phases formed in neutral aqueous solutions of tryptophan and indole-3-acetic acid

    International Nuclear Information System (INIS)

    Moessbauer, FTIR and XRD analyses showed that in aqueous medium in air in the presence of L-tryptophan (Trp) or indole-3-acetic acid (IAA) the ambient-temperature ageing of the precipitates formed from ferrous sulphate at pH ∼ 7 gave composite phases with varying proportions of γ-FeOOH (a dominating crystalline phase), α-FeOOH (both fine-grained, showing superparamagnetic behaviour at 298 K, and relatively better crystallized) and amorphous ferric hydroxide. The experimental data suggested a competition for adsorption sites at the oxyhydroxide surface in the suspension during phase transformations, as well as the transformation of γ-FeOOH (and/or amorphous ferric hydroxide) to α-FeOOH via the dissolution-reprecipitation mechanism. The formation of certain ferric oxyhydroxide phases in the presence of Trp and IAA - released e.g., in the course of bacterial and plant metabolism - can contribute to the regulation of soil mineral composition. (author)

  16. Analysis of Bacterial Lipooligosaccharides by MALDI-TOF MS with Traveling Wave Ion Mobility

    Science.gov (United States)

    Phillips, Nancy J.; John, Constance M.; Jarvis, Gary A.

    2016-07-01

    Lipooligosaccharides (LOS) are major microbial virulence factors displayed on the outer membrane of rough-type Gram-negative bacteria. These amphipathic glycolipids are comprised of two domains, a core oligosaccharide linked to a lipid A moiety. Isolated LOS samples are generally heterogeneous mixtures of glycoforms, with structural variability in both domains. Traditionally, the oligosaccharide and lipid A components of LOS have been analyzed separately following mild acid hydrolysis, although important acid-labile moieties can be cleaved. Recently, an improved method was introduced for analysis of intact LOS by MALDI-TOF MS using a thin layer matrix composed of 2,4,6-trihydroxyacetophenone (THAP) and nitrocellulose. In addition to molecular ions, the spectra show in-source "prompt" fragments arising from regiospecific cleavage between the lipid A and oligosaccharide domains. Here, we demonstrate the use of traveling wave ion mobility spectrometry (TWIMS) for IMS-MS and IMS-MS/MS analyses of intact LOS from Neisseria spp. ionized by MALDI. Using IMS, the singly charged prompt fragments for the oligosaccharide and lipid A domains of LOS were readily separated into resolved ion plumes, permitting the extraction of specific subspectra, which led to increased confidence in assigning compositions and improved detection of less abundant ions. Moreover, IMS separation of precursor ions prior to collision-induced dissociation (CID) generated time-aligned, clean MS/MS spectra devoid of fragments from interfering species. Incorporating IMS into the profiling of intact LOS by MALDI-TOF MS exploits the unique domain structure of the molecule and offers a new means of extracting more detailed information from the analysis.

  17. Analysis of Bacterial Lipooligosaccharides by MALDI-TOF MS with Traveling Wave Ion Mobility

    Science.gov (United States)

    Phillips, Nancy J.; John, Constance M.; Jarvis, Gary A.

    2016-04-01

    Lipooligosaccharides (LOS) are major microbial virulence factors displayed on the outer membrane of rough-type Gram-negative bacteria. These amphipathic glycolipids are comprised of two domains, a core oligosaccharide linked to a lipid A moiety. Isolated LOS samples are generally heterogeneous mixtures of glycoforms, with structural variability in both domains. Traditionally, the oligosaccharide and lipid A components of LOS have been analyzed separately following mild acid hydrolysis, although important acid-labile moieties can be cleaved. Recently, an improved method was introduced for analysis of intact LOS by MALDI-TOF MS using a thin layer matrix composed of 2,4,6-trihydroxyacetophenone (THAP) and nitrocellulose. In addition to molecular ions, the spectra show in-source "prompt" fragments arising from regiospecific cleavage between the lipid A and oligosaccharide domains. Here, we demonstrate the use of traveling wave ion mobility spectrometry (TWIMS) for IMS-MS and IMS-MS/MS analyses of intact LOS from Neisseria spp. ionized by MALDI. Using IMS, the singly charged prompt fragments for the oligosaccharide and lipid A domains of LOS were readily separated into resolved ion plumes, permitting the extraction of specific subspectra, which led to increased confidence in assigning compositions and improved detection of less abundant ions. Moreover, IMS separation of precursor ions prior to collision-induced dissociation (CID) generated time-aligned, clean MS/MS spectra devoid of fragments from interfering species. Incorporating IMS into the profiling of intact LOS by MALDI-TOF MS exploits the unique domain structure of the molecule and offers a new means of extracting more detailed information from the analysis.

  18. A novel ion-beam-mutation effect application in identification of gene involved in bacterial antagonism to fungal infection of ornamental crops

    Energy Technology Data Exchange (ETDEWEB)

    Mahadtanapuk, S. [Faculty of Agriculture and Natural Resources, University of Phayao, Maeka, Muang, Phayao 56000 (Thailand); Teraarusiri, W. [Central Laboratory, University of Phayao, Maeka, Muang, Phayao 56000 (Thailand); Nanakorn, W. [The Crown Property Bureau, 173 Nakhonratchasrima Road, Dusit, Bangkok 10300 (Thailand); Yu, L.D., E-mail: yuld@thep-center.org [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Anuntalabhochai, S., E-mail: soanu.1@gmail.com [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2014-05-01

    Highlights: • Ion beam bombardment induced mutation in bacterial B. licheniformis. • A mutant lost antifungal activity. • DNA fingerprint of the mutant was analyzed. • The lost gene was indentified to code for TrxR gene. • TrxR gene from B. licheniformis expressed the flower antagonism to fungi. - Abstract: This work is on a novel application of ion beam effect on biological mutation. Bacillus licheniformis (B. licheniformis) is a common soil bacterium with an antagonistic effect on Curcuma alismatifolia Gagnep. and Chrysanthemum indicum Linn. In an attempt to control fungal diseases of local crops by utilizing B. licheniformis, we carried out gene analysis of the bacterium to understand the bacterial antagonistic mechanism. The bacterial cells were bombarded to induce mutations using nitrogen ion beam. After ion bombardment, DNA analysis revealed that the modified polymorphism fragment present in the wild type was missing in a bacterial mutant which lost the antifungal activity. The fragments conserved in the wild type but lost in the mutant bacteria was identified to code for the thioredoxin reductase (TrxR) gene. The gene analysis showed that the TrxR gene from B. licheniformis had the expression of the antagonism to fungi in a synchronous time evolution with the fungus inhibition when the bacteria were co-cultivated with the fungi. The collective results indicate the TrxR gene responsible for the antagonism of bacteria B. licheniformis to fungal infection.

  19. A novel ion-beam-mutation effect application in identification of gene involved in bacterial antagonism to fungal infection of ornamental crops

    International Nuclear Information System (INIS)

    Highlights: • Ion beam bombardment induced mutation in bacterial B. licheniformis. • A mutant lost antifungal activity. • DNA fingerprint of the mutant was analyzed. • The lost gene was indentified to code for TrxR gene. • TrxR gene from B. licheniformis expressed the flower antagonism to fungi. - Abstract: This work is on a novel application of ion beam effect on biological mutation. Bacillus licheniformis (B. licheniformis) is a common soil bacterium with an antagonistic effect on Curcuma alismatifolia Gagnep. and Chrysanthemum indicum Linn. In an attempt to control fungal diseases of local crops by utilizing B. licheniformis, we carried out gene analysis of the bacterium to understand the bacterial antagonistic mechanism. The bacterial cells were bombarded to induce mutations using nitrogen ion beam. After ion bombardment, DNA analysis revealed that the modified polymorphism fragment present in the wild type was missing in a bacterial mutant which lost the antifungal activity. The fragments conserved in the wild type but lost in the mutant bacteria was identified to code for the thioredoxin reductase (TrxR) gene. The gene analysis showed that the TrxR gene from B. licheniformis had the expression of the antagonism to fungi in a synchronous time evolution with the fungus inhibition when the bacteria were co-cultivated with the fungi. The collective results indicate the TrxR gene responsible for the antagonism of bacteria B. licheniformis to fungal infection

  20. Effect of Fe-chelating complexes on a novel M2FC performance with ferric chloride and ferricyanide catholytes.

    Science.gov (United States)

    Chung, Kyungmi; Lee, Ilgyu; Han, Jong-In

    2012-01-01

    As an effort to better utilize the microbial fuel cell (MFC) technology, we previously proposed an innovative MFC system named M2FC consisting of ferric-based MFC part and ferrous-based fuel cell (FC) part. In this reactor, ferric ion, the catholyte in the MFC part, was efficiently regenerated by the FC part with the generation of additional electricity. When both units were operated separately, the ferric-based MFC part produced approximately 1360 mW m(-2) of power density with FeCl(3) as catholyte and Fe-citrate as anolyte. The ferrous-based FC part with FeCl(3) as catholyte and Fe-EDTA as anolyte displayed the highest power density (1500 mW m(-2)), while that with ferricyanide as catholyte and Fe-noligand as anolyte had the lowest power density (380 mW m(-2)). The types of catholytes and chelating complexes as anolyte were found to play important roles in the reduction of ferric ions and oxidation of ferrous ion. Linear sweep voltammetry results supported that the cathode electrolytes were electrically active and these agreed well with the M2FC reactor performance. These results clearly showed that ligands played critical role in the efficiency and rate for recycling iron ion and thus the M2FC performance. PMID:22018860

  1. Removal and recovery of toxic silver ion using deep-sea bacterial generated biogenic manganese oxides.

    Directory of Open Access Journals (Sweden)

    Yuanjun Pei

    Full Text Available Products containing silver ion (Ag(+ are widely used, leading to a large amount of Ag(+-containing waste. The deep-sea manganese-oxidizing bacterium Marinobacter sp. MnI7-9 efficiently oxidizes Mn(2+ to generate biogenic Mn oxide (BMO. The potential of BMO for recovering metal ions by adsorption has been investigated for some ions but not for Ag(+. The main aim of this study was to develop effective methods for adsorbing and recovering Ag using BMO produced by Marinobacter sp. MnI7-9. In addition, the adsorption mechanism was determined using X-ray photoelectron spectroscopy analysis, specific surface area analysis, adsorption kinetics and thermodynamics. The results showed that BMO had a higher adsorption capacity for Ag(+ compared to the chemical synthesized MnO2 (CMO. The isothermal absorption curves of BMO and CMO both fit the Langmuir model well and the maximum adsorption capacities at 28°C were 8.097 mmol/g and 0.787 mmol/g, for BMO and CMO, respectively. The change in enthalpy (ΔH(θ for BMO was 59.69 kJ/mol indicating that it acts primarily by chemical adsorption. The change in free energy (ΔG(θ for BMO was negative, which suggests that the adsorption occurs spontaneously. Ag(+ adsorption by BMO was driven by entropy based on the positive ΔS(θ values. The Ag(+ adsorption kinetics by BMO fit the pseudo-second order model and the apparent activation energy of Ea is 21.72 kJ/mol. X-ray photoelectron spectroscopy analysis showed that 15.29% Ag(+ adsorbed by BMO was transferred to Ag(0 and meant that redox reaction had happened during the adsorption. Desorption using nitric acid and Na2S completely recovered the Ag. The results show that BMO produced by strain MnI7-9 has potential for bioremediation and reutilization of Ag(+-containing waste.

  2. Removal and recovery of toxic silver ion using deep-sea bacterial generated biogenic manganese oxides.

    Science.gov (United States)

    Pei, Yuanjun; Chen, Xiao; Xiong, Dandan; Liao, Shuijiao; Wang, Gejiao

    2013-01-01

    Products containing silver ion (Ag(+)) are widely used, leading to a large amount of Ag(+)-containing waste. The deep-sea manganese-oxidizing bacterium Marinobacter sp. MnI7-9 efficiently oxidizes Mn(2+) to generate biogenic Mn oxide (BMO). The potential of BMO for recovering metal ions by adsorption has been investigated for some ions but not for Ag(+). The main aim of this study was to develop effective methods for adsorbing and recovering Ag using BMO produced by Marinobacter sp. MnI7-9. In addition, the adsorption mechanism was determined using X-ray photoelectron spectroscopy analysis, specific surface area analysis, adsorption kinetics and thermodynamics. The results showed that BMO had a higher adsorption capacity for Ag(+) compared to the chemical synthesized MnO2 (CMO). The isothermal absorption curves of BMO and CMO both fit the Langmuir model well and the maximum adsorption capacities at 28°C were 8.097 mmol/g and 0.787 mmol/g, for BMO and CMO, respectively. The change in enthalpy (ΔH(θ)) for BMO was 59.69 kJ/mol indicating that it acts primarily by chemical adsorption. The change in free energy (ΔG(θ)) for BMO was negative, which suggests that the adsorption occurs spontaneously. Ag(+) adsorption by BMO was driven by entropy based on the positive ΔS(θ) values. The Ag(+) adsorption kinetics by BMO fit the pseudo-second order model and the apparent activation energy of Ea is 21.72 kJ/mol. X-ray photoelectron spectroscopy analysis showed that 15.29% Ag(+) adsorbed by BMO was transferred to Ag(0) and meant that redox reaction had happened during the adsorption. Desorption using nitric acid and Na2S completely recovered the Ag. The results show that BMO produced by strain MnI7-9 has potential for bioremediation and reutilization of Ag(+)-containing waste. PMID:24312566

  3. Expressing a bacterial mercuric ion binding protein in plant for phytoremediation of heavy metals.

    Science.gov (United States)

    Hsieh, Ju-Liang; Chen, Ching-Yi; Chiu, Meng-Hsuen; Chein, Mei-Fang; Chang, Jo-Shu; Endo, Ginro; Huang, Chieh-Chen

    2009-01-30

    A specific mercuric ion binding protein (MerP) originating from transposon TnMERI1 of Bacillus megaterium strain MB1 isolated from Minamata Bay displayed good adsorption capability for a variety of heavy metals. In this study, the Gram-positive MerP protein was expressed in transgenic Arabidopsis to create a model system for phytoremediation of heavy metals. Under control of an actin promoter, the transgenic Arabidpsis showed higher tolerance and accumulation capacity for mercury, cadium and lead when compared with the control plant. Results from confocal microscopy analysis also indicate that MerP was localized at the cell membrane and vesicles of plant cells. The developed transgenic plants possessing excellent metal-accumulative ability could have potential applications in decontamination of heavy metals. PMID:18538925

  4. Inactivation, DNA double strand break induction and their rejoining in bacterial cells irradiated with heavy ions

    Science.gov (United States)

    Schaefer, M.; Zimmermann, H.; Schmitz, C.

    1994-01-01

    Besides inactivation one of the major interests in our experiments is to study the primary damage in the DNA double strand breaks (DSB) after heavy ion irradiation. These damages lead not only to cell death but also under repair activities to mutations. In further experiments we have investigated the inactivation with two different strains of Deinococcus radiodurans (R1, Rec 30) and the induction of DSB as well as the rejoining of DSB in stationary cells of E. coli (strain B/r) irradiated with radiations of different quality. In the latter case irradiations were done so that the cell survival was roughly at the same level. We measured the DSB using the pulse field gelelectrophoresis which allows to separate between intact (circular) and damaged (linear) DNA. The irradiated cells were transferred to NB medium and incubated for different times to allow rejoining.

  5. Leaching of zinc sulfide by Thiobacillus ferrooxidans: bacterial oxidation of the sulfur product layer increases the rate of zinc sulfide dissolution at high concentrations of ferrous ions.

    Science.gov (United States)

    Fowler, T A; Crundwell, F K

    1999-12-01

    This paper reports the results of leaching experiments conducted with and without Thiobacillus ferrooxidans at the same conditions in solution. The extent of leaching of ZnS with bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, while no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shrinking-core model shows that the chemical leaching of ZnS is limited by the diffusion of ferrous ions through the sulfur product layer at high concentrations of ferrous ions. The analysis of the data shows that diffusion through the product layer does not limit the rate of dissolution when bacteria are present. This suggests that the action of T. ferrooxidans in oxidizing the sulfur formed on the particle surface is to remove the barrier to diffusion by ferrous ions. PMID:10583978

  6. Leaching of Zinc Sulfide by Thiobacillus ferrooxidans: Bacterial Oxidation of the Sulfur Product Layer Increases the Rate of Zinc Sulfide Dissolution at High Concentrations of Ferrous Ions

    OpenAIRE

    Fowler, T. A.; Crundwell, F. K.

    1999-01-01

    This paper reports the results of leaching experiments conducted with and without Thiobacillus ferrooxidans at the same conditions in solution. The extent of leaching of ZnS with bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, while no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shr...

  7. Ferric Dicitrate Transport System (Fec) of Shigella flexneri 2a YSH6000 Is Encoded on a Novel Pathogenicity Island Carrying Multiple Antibiotic Resistance Genes

    OpenAIRE

    Luck, Shelley N.; Turner, Sally A.; Rajakumar, Kumar; Sakellaris, Harry; Adler, Ben

    2001-01-01

    Iron uptake systems which are critical for bacterial survival and which may play important roles in bacterial virulence are often carried on mobile elements, such as plasmids and pathogenicity islands (PAIs). In the present study, we identified and characterized a ferric dicitrate uptake system (Fec) in Shigella flexneri serotype 2a that is encoded by a novel PAI termed the Shigella resistance locus (SRL) PAI. The fec genes are transcribed in S. flexneri, and complementation of a fec deletion...

  8. A novel ion-beam-mutation effect application in identification of gene involved in bacterial antagonism to fungal infection of ornamental crops

    Science.gov (United States)

    Mahadtanapuk, S.; Teraarusiri, W.; Nanakorn, W.; Yu, L. D.; Thongkumkoon, P.; Anuntalabhochai, S.

    2014-05-01

    This work is on a novel application of ion beam effect on biological mutation. Bacillus licheniformis (B. licheniformis) is a common soil bacterium with an antagonistic effect on Curcuma alismatifolia Gagnep. and Chrysanthemum indicum Linn. In an attempt to control fungal diseases of local crops by utilizing B. licheniformis, we carried out gene analysis of the bacterium to understand the bacterial antagonistic mechanism. The bacterial cells were bombarded to induce mutations using nitrogen ion beam. After ion bombardment, DNA analysis revealed that the modified polymorphism fragment present in the wild type was missing in a bacterial mutant which lost the antifungal activity. The fragments conserved in the wild type but lost in the mutant bacteria was identified to code for the thioredoxin reductase (TrxR) gene. The gene analysis showed that the TrxR gene from B. licheniformis had the expression of the antagonism to fungi in a synchronous time evolution with the fungus inhibition when the bacteria were co-cultivated with the fungi. The collective results indicate the TrxR gene responsible for the antagonism of bacteria B. licheniformis to fungal infection.

  9. In-tank hydrogen-ferric ion recombination

    Science.gov (United States)

    Selverston, S.; Savinell, R. F.; Wainright, J. S.

    2016-08-01

    An H2sbnd Fe3+ recombination method is being developed for all-iron flow batteries. Working principles are described and a proof-of-concept in-tank reactor is demonstrated. A membrane-less galvanic reactor is characterized using potential, polarization and impedance measurements at hydrogen partial pressures ranging from 0.3 to 11.3 psig. Through a vertical reactor geometry, hydrogen recombination rates of up to 60 mA cm-2 were measured at PH2 = 4.5 psig for a reactor with a platinum loading of 3.2 mg cm-2, based on the geometric catalyzed area. This is equivalent to over 375 mA cm-2 with respect to the cross sectional area of the reactor at the waterline. This rate is sufficient that the reactor will readily fit inside the positive reservoir of a flow battery. The reactor was found to be resistant to degradation by flooding or catalyst loss.

  10. Bacterial carbonatogenesis

    International Nuclear Information System (INIS)

    Several series of experiments in the laboratory as well as in natural conditions teach that the production of carbonate particles by heterotrophic bacteria follows different ways. The 'passive' carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. The 'active' carbonatogenesis is independent of the metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. Carbonatogenesis appears to be the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. The active carbonatogenesis seems to start first. It is followed by the passive one which induces the growth of initially produced particles. The yield of heterotrophic bacterial carbonatogenesis and the amounts of solid carbonates production by bacteria are potentially very high as compared to autotrophic or chemical sedimentation from marine, paralic or continental waters. Furthermore, the bacterial processes are environmentally very ubiquitous; they just require organic matter enrichment. Thus, apart from purely evaporite and autotrophic ones, all Ca and/or Mg carbonates must be considered as from heterotrophic bacterial origin. By the way, the carbon of carbonates comes from primary organic matter. Such considerations ask questions about some interpretations from isotopic data on carbonates. Finally, bacterial heterotrophic carbonatogenesis appears as a fundamental phase in the relationships between atmosphere and lithosphere and in the geo-biological evolution of Earth. (author)

  11. Radiation synovectomy with 165-dysprosium ferric hydroxide

    International Nuclear Information System (INIS)

    Treatment of chronic rheumatoid synovitis (RS) is directed to control the inflammatory process causing pain and disability. Radiation synovectomy is suggested to be an alternative to surgical treatment, but its clinical use has been restricted because of significant leakage (>10%) associated with the use of the standard radionuclide 90-Yttrium (used as 90-Yttrium silicate colloid) and because of its long physical half-life of 64 hours prolonging the patients' stay in the hospital. 165-Dysprosium possesses promising nuclear properties for the treatment of patients suffering from RS. The maximum soft tissue penetration of its β-particles is 5.7 mm which is the range necessary to penetrate the inflammed synovia. Using as carrier ferric hydroxide macroaggregates (DFH) 165-Dy is expected to minimize the cumulative radiation dose to non-target organs by its very low leakage. Animal studies were performed in 13 rats and 6 rabbits to obtain the rationale and safety data for its clinical evaluation. These studies revealed that 98.2±0.6% of the injected dose remained in the joint with a nontarget organ uptake of less than 0.1%. Clinical results were obtained from 8 patients with rheumatoid arthritis. 24 hours after injection scintigraphy was performed over the treated joint and the liver region revealing no detectable leakage of the injected activity from the joint. Blood pool activity was also assessed revealing a leakage of 0.02% of the dose injected in the knee 24 hours after injection. Preliminary results from the ongoing first clinical trial in Austria also revealed an excellent to good response in 5 out of 8 patients of whom one has been in remission for more than eight months now. Radiosynovectomy with 165-Dy GFH offers promising physical, experimental, and preliminary clinical results which suggest its use as an ambulatory standard therapy of RS. (authors)

  12. Kinetics of iron acquisition from ferric siderophores by Paracoccus denitrificans

    International Nuclear Information System (INIS)

    The kinetics of iron accumulation by iron-starved Paracoccus denitrificans during the first 2 min of exposure to 55Fe-labeled ferric siderophore chelates is described. Iron is acquired from the ferric chelate of the natural siderophore L-parabactin in a process exhibiting biphastic kinetics by Lineweaver-Burk analysis. The kinetic data for 1 microM less than [Fe L-parabactin] less than 10 microM fit a regression line which suggests a low-affinity system (Km = 3.9 +/- 1.2 microM, Vmax = 494 pg-atoms of 55Fe min-1 mg of protein-1), whereas the data for 0.1 microM less than or equal to [Fe L-parabactin] less than or equal to 1 microM fit another line consistent with a high-affinity system (Km = 0.24 +/- 0.06 microM, Vmax = 108 pg-atoms of 55Fe min-1 mg of protein-1). The Km of the high-affinity uptake is comparable to the binding affinity we had previously reported for the purified ferric L-parabactin receptor protein in the outer membrane. In marked contrast, ferric D-parabactin data fit a single regression line corresponding to a simple Michaelis-Menten process with comparatively low affinity (Km = 3.1 +/- 0.9 microM, Vmax = 125 pg-atoms of 55Fe min-1 mg of protein-1). Other catecholamide siderophores with an intact oxazoline ring derived from L-threonine (L-homoparabactin, L-agrobactin, and L-vibriobactin) also exhibit biphasic kinetics with a high-affinity component similar to ferric L-parabactin. Circular dichroism confirmed that these ferric chelates, like ferric L-parabactin, exist as the lambda enantiomers

  13. Removal of radioactive strontium from water by coagulation-flocculation with ferric hydroxide

    International Nuclear Information System (INIS)

    A systematic study of the removal of the radioactive fission product strontium from aqueous solution by ferric hydroxide flocs has shown that strontium can be removed effectively, in contrast to caesium which is poorly removed (<= 5%) under all conditions examined. Removal of strontium was enhanced by raising pH to a maximum of 10.5, increasing the iron/ strontium ratio, or by adding phosphate ion, provided the phosphate/iron mole ratio did not exceed 0.33. In the absence of phosphate the optimum conditions for strontium removal, over the range of iron and strontium concentrations examined, were pH 10 and strontium/iron mole ratio 0.08. Addition of phosphate reduced the pH at which significant removal was obtained to about 8. The mechanism of removal has been identified as an ion-exchange reaction at the surface of the ferric hydroxide particles; consequently, when considering the process for the removal of strontium-90 from hard natural or process waters competitive effects from the larger concentrations of calcium and magnesium present in the water become important. (author)

  14. Separation of Fe (III) ions from acidic leach liquor of metasummatite Saghand ore by anion exchange resins

    International Nuclear Information System (INIS)

    Ferric ions in dilute acidic leach liquor of uranium ore of Saghand were separated by anion exchange resins. In this research, a simulated solution similar to the actual leach liquor of Saghand was prepared. The simulated solution which was containing chloride and ferric ions. rare earth elements, and some other impurities was treated by different types of Dowex anion exchange resins for ferric ions removal. It appeared that hydrochloric acidic concentration, resin types and particle sizes have a great impact on ferric ions adsorption. Dowex 1 X 4 (200-400 mesh) has the best adsorption of 91% in simulated solution and 79% in actual leach liquor of uranium ore of Saghand respectively

  15. Restraining Sodium Volatilization in the Ferric Bauxite Direct Reduction System

    Directory of Open Access Journals (Sweden)

    Wentao Hu

    2016-03-01

    Full Text Available Direct reduction is an emerging utilization technology of ferric bauxite. However, it requires much more sodium carbonate than ordinary bauxite does. The volatilization is one of the most significant parts of sodium carbonate consumption, as reported in previous studies. Based on the new direct reduction method for utilization of ferric bauxite, this paper has systematically investigated factors including heating temperature, heating time, and sodium carbonate dosage influencing sodium volatilization. For the purpose of reducing sodium volatilization, the Box–Benhken design was employed, and the possibility of separating iron and sodium after direct reduction was also investigated.

  16. Enhanced dark hydrogen fermentation by addition of ferric oxide nanoparticles using Enterobacter aerogenes.

    Science.gov (United States)

    Lin, Richen; Cheng, Jun; Ding, Lingkan; Song, Wenlu; Liu, Min; Zhou, Junhu; Cen, Kefa

    2016-05-01

    Ferric oxide nanoparticles (FONPs) were used to facilitate dark hydrogen fermentation using Enterobacter aerogenes. The hydrogen yield of glucose increased from 164.5±2.29 to 192.4±1.14mL/g when FONPs concentration increased from 0 to 200mg/L. SEM images of E. aerogenes demonstrated the existence of bacterial nanowire among cells, suggesting FONPs served as electron conduits to enhance electron transfer. TEM showed cellular internalization of FONPs, indicating hydrogenase synthesis and activity was potentially promoted due to the released iron element. When further increasing FONPs concentration to 400mg/L, the hydrogen yield of glucose decreased to 147.2±2.54mL/g. Soluble metabolic products revealed FONPs enhanced acetate pathway of hydrogen production, but weakened ethanol pathway. This shift of metabolic pathways allowed more nicotinamide adenine dinucleotide for reducing proton to hydrogen. PMID:26890796

  17. Bacterial gastroenteritis

    Science.gov (United States)

    Infectious diarrhea - bacterial gastroenteritis; Acute gastroenteritis; Gastroenteritis - bacterial ... Bacterial gastroenteritis can affect 1 person or a group of people who all ate the same food. It is ...

  18. Functional transfer of an essential aspartate for the ion-binding site in the stator proteins of the bacterial flagellar motor.

    Science.gov (United States)

    Terashima, Hiroyuki; Kojima, Seiji; Homma, Michio

    2010-04-01

    Rotation of the bacterial flagellar motor exploits the electrochemical potential of the coupling ion (H(+) or Na(+)) as its energy source. In the marine bacterium Vibrio alginolyticus, the stator complex is composed of PomA and PomB, and conducts Na(+) across the cytoplasmic membrane to generate rotation. The transmembrane (TM) region of PomB, which forms the Na(+)-conduction pathway together with TM3 and TM4 of PomA, has a highly conserved aspartate residue (Asp24) that is essential for flagellar rotation. This residue contributes to the Na(+)-binding site. However, it is not clear whether residues other than Asp24 are involved in binding the coupling ion. We examined the possibility that loss of the negative charge of Asp24 can be suppressed by introduction of negatively charged residues in TM3 or TM4 of PomA. The motility defect associated with the D24N substitution in PomB could be rescued only by a N194D substitution in PomA. This result suggests that there must be a negatively charged ion-binding pocket in the stator complex but that the presence of a negatively charged residue at position 24 of PomB is not essential. A tandemly fused PomA dimer containing the N194D mutation either in its N-terminal or C-terminal half with PomB-D24N was functional, suggesting that PomB-D24N can form an ion-binding pocket with either subunit of PomA dimer. The findings obtained in this study provide important clues to the mechanism of ion binding in the stator complex. PMID:20122938

  19. Box-Behnken experimental design for chromium(VI) ions removal by bacterial cellulose-magnetite composites.

    Science.gov (United States)

    Stoica-Guzun, Anicuta; Stroescu, Marta; Jinga, Sorin Ion; Mihalache, Nicoleta; Botez, Adriana; Matei, Cristian; Berger, Daniela; Damian, Celina Maria; Ionita, Valentin

    2016-10-01

    In this study bacterial cellulose-magnetite composites were synthesised for the removal of chromium(VI) from aqueous solutions. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis and X-ray Photoelectron Spectroscopy (XPS) were used to characterize the bacterial cellulose-magnetite composites and to reveal the uniform dispersion of nanomagnetite in the BC matrix. Magnetic properties were also measured to confirm the magnetite immobilization on bacterial cellulose membrane. The effects of initial Cr(VI) concentration, solution pH and solid/liquid ratio upon chromium removal were examined using the statistical Box-Behnken Design. Because of the possibility of magnetite dissolution during chromium(VI) adsorption, the degree of iron leaching was also analysed in the same conditions as Cr(VI) adsorption. From the factors affecting chromium(VI) adsorption the most important was solution pH. The highest Cr(VI) removal efficiency was observed at pH 4, accompanied by the lowest iron leaching in the solution. The adsorption experiments also indicated that the adsorption process of chromium(VI) is well described by Freundlich adsorption model. Our results proved that the BC-magnetite composites could be used for an efficient removal of chromium(VI) from diluted solutions with a minimum magnetite dissolution during operation. PMID:27343705

  20. Reaction of ferric leghemoglobin with H2O2

    DEFF Research Database (Denmark)

    Moreau, S; Davies, M J; Puppo, A

    1995-01-01

    Ferric leghemoglobin in the presence of H2O2 is known to give rise to protein radicals, at least one of which is centred on a tyrosine residue. These radicals are quenched by at least two processes. The first one involves an intramolecular heme-protein cross-link probably involving the tyrosine...

  1. Ferric Citrate Controls Phosphorus and Delivers Iron in Patients on Dialysis

    OpenAIRE

    Lewis, Julia B.; Sika, Mohammed; Koury, Mark J.; Chuang, Peale; Schulman, Gerald; Smith, Mark T.; Whittier, Frederick C.; Linfert, Douglas R.; Galphin, Claude M.; Athreya, Balaji P.; Nossuli, A. Kaldun Kaldun; Chang, Ingrid J.; Blumenthal, Samuel S.; Manley, John; Zeig, Steven

    2014-01-01

    Patients on dialysis require phosphorus binders to prevent hyperphosphatemia and are iron deficient. We studied ferric citrate as a phosphorus binder and iron source. In this sequential, randomized trial, 441 subjects on dialysis were randomized to ferric citrate or active control in a 52-week active control period followed by a 4-week placebo control period, in which subjects on ferric citrate who completed the active control period were rerandomized to ferric citrate or placebo. The primary...

  2. Degradation of the Ferric Chelate of EDTA by a Pure Culture of an Agrobacterium sp

    OpenAIRE

    Lauff, John J.; Steele, D. Bernie; Coogan, Louise A.; Breitfeller, James M.

    1990-01-01

    A pure culture of an Agrobacterium sp. (deposited as ATCC 55002) that mineralizes the ferric chelate of EDTA (ferric-EDTA) was isolated by selective enrichment from a treatment facility receiving industrial waste containing ferric-EDTA. The isolate grew on ferric-EDTA as the sole carbon source at concentrations exceeding 100 mM. As the degradation proceeded, carbon dioxide, ammonia, and an unidentified metabolite(s) were produced; the pH increased, and iron was precipitated from solution. The...

  3. Evaluation of polyaluminium ferric chloride (PAFC) as a composite coagulant for water and wastewater treatment.

    Science.gov (United States)

    Gao, B; Yue, Q; Miao, J

    2003-01-01

    Coal gangue is a kind of waste from coal mine processing. Polyaluminium ferric chloride (PAFC), a new type of inorganic composite coagulant, was prepared by using the waste from the Mineral Bureau of Yanzhou, China, hydrochloric acid and calcium carbonate as raw materials. The relationship between the stability of ferric ion and the ionic strength of solution was investigated. The zeta potential of PAFC hydrolysis products of PAFC and the coagulation performances under different pH value were discussed. The turbidity removal properties of PAFC, polyaluminium (PAC) and polyferric sulfate (PFS) were compared, and the color removal effect of PAFC for the wastewater containing suspended dyes was also tested. In addition, the coagulation performance of PAFC for actual wastewaters from petrochemical plant, iron and steel plant, and coal mining processing was evaluated. The experimental results suggest that PAFC took a maximum value of zeta potential at about pH 5.8 on the positive side. Compared with PAC, PAFC gives better turbidity removal performance in the range of pH from 7.0 to 8.4. PAFC gives good color removal performance on suspension dyes. PAFC also gives good wastewater purifying results for the actual wastewater. Therefore, PAFC is a high-effect and stable water treatment agent. PMID:12578184

  4. Optical and electrical properties of thin films of bismuth ferric oxide

    International Nuclear Information System (INIS)

    The bismuth ferric oxide (BFO) has caused great attention in recent years because of their multi ferric properties, making it very attractive for different technological applications. In this paper simultaneous ablation of two white (Bi and Fe2O3) was used in a reactive atmosphere (containing oxygen) to deposit thin films of BFO. The composition of the films is changed by controlling the plasma parameters such as the average kinetic energy of the ions (E p) and the plasma density (Np). The effects caused by excess of Bi and Fe in atomic structure and the optical and electrical properties of the films BiFeO3 in terms of plasma parameters were studied. The X-ray diffraction patterns of BFO samples with excess of bismuth above 2% at. They exhibited small changes in structure leading to improved levels of leakage currents compared to levels of the film with a stoichiometry close to BiFeO3 composition. These samples showed a secondary phase (Bi25FeO40 selenite type) that led to the increase in the values of band gap and resistivity as well as the improvement of the piezoelectric properties. On the other hand, the films with iron excess showed as secondary phase compounds of iron oxide (α - γ-Fe2O3) that caused increments in the conductivity and decrease in the values of band gap. The results are discussed in terms of the excesses of Bi and Fe which were correlated with the plasma parameters. (Author)

  5. Precision and sensitivity of the measurement of 15N enrichment in D-alanine from bacterial cell walls using positive/negative ion mass spectrometry

    Science.gov (United States)

    Tunlid, A.; Odham, G.; Findlay, R. H.; White, D. C.

    1985-01-01

    Sensitive detection of cellular components from specific groups of microbes can be utilized as 'signatures' in the examination of microbial consortia from soils, sediments or biofilms. Utilizing capillary gas chromatography/mass spectrometry and stereospecific derivatizing agents, D-alanine, a component localized in the prokaryotic (bacterial) cell wall, can be detected reproducibly. Enrichments of D-[15N]alanine determined in E. coli grown with [15N]ammonia can be determined with precision at 1.0 atom%. Chemical ionization with methane gas and the detection of negative ions (M - HF)- and (M - F or M + H - HF)- formed from the heptafluorobutyryl D-2 butanol ester of D-alanine allowed as little as 8 pg (90 fmol) to be detected reproducibly. This method can be utilized to define the metabolic activity in terms of 15N incorporation at the level of 10(3)-10(4) cells, as a function of the 15N-14N ratio.

  6. Evaluation of ferric oxide and ferric citrate for their effects on fermentation, production of sulfide and methane, and abundance of select microbial populations using in vitro rumen cultures.

    Science.gov (United States)

    Wu, Hao; Meng, Qingxiang; Yu, Zhongtang

    2016-07-01

    This study systematically evaluated the effect of ferric iron on sulfate reduction to sulfide, feed digestion and fermentation, methane production, and populations of select ruminal microbes using in vitro rumen cultures. Ferric oxide (Fe2O3) and ferric citrate (C6H5FeO7) at six concentrations (0, 25, 50, 100, 150, and 200mg/L as Fe(3+)) were tested. Ferric iron decreased production of both H2S gas in culture headspace (up to 71.9%) and aqueous sulfide (up to 80.8%), without adversely affecting other fermentation parameters, with ferric citrate being more effective than ferric oxide. Total archaeal population was increased by ferric citrate, but methane production was not affected significantly. The population of sulfate reducing bacteria was affected differently by ferric oxide than by ferric citrate. The results of this study could guide future in vivo studies to develop effective solutions to abate sulfur-associated polioencephalomalacia in cattle fed high-sulfur diet such as dried distiller's grains with solubles. PMID:27043055

  7. Effect of hydrolysis on the diffusion of ferric sulphate in aqueous solutions at T = 298.15 K

    International Nuclear Information System (INIS)

    Highlights: ► Diffusion coefficients of ferric sulphate in aqueous dilute solutions. ► Influence of the hydrolysis on diffusion of ferric sulphate in the aqueous media. ► Estimation of the percentage of hydrogen ions, α, resulting from the hydrolysis of Fe3+ in aqueous solutions. - Abstract: Diffusion coefficients of the Fe2(SO4)3)/water system at T = 298.15 K and at concentrations between 0.050 mol · dm−3 and 0.200 mol · dm−3 have been measured, using a conductimetric cell and an automatic apparatus to follow diffusion. The cell uses an open-ended capillary method. A conductimetric technique is used to follow the diffusion process by measuring the resistance of a solution inside the capillaries at recorded times. These data are discussed on the basis of the Onsager–Fuoss model. The diffusion of Fe2(SO4)3 is clearly affected by the Fe (III) hydrolysis. These data permit us to have a better understanding of the structure of such systems and the thermodynamic behaviour of ferric sulphate in different media.

  8. Evaluating the efficacy of the new Ion PGM Hi-Q Sequencing Kit applied to bacterial genomes.

    Science.gov (United States)

    Pereira, Felipe L; Soares, Siomar C; Dorella, Fernanda A; Leal, Carlos A G; Figueiredo, Henrique C P

    2016-05-01

    Benchtop NGS platforms are constantly evolving to follow new advances in genomics. Thus, the manufacturers are making improvements, such as the recent Ion PGM Hi-Q chemistry. We evaluate the efficacy of this new Hi-Q approach by comparing it with the former Ion PGM kit and the Illumina MiSEQ Nextera 3rd version. The Hi-Q chemistry showed improvement on mapping reads, with 49 errors for 10kbp mapped; in contrast, the former kit had 89 errors. Additionally, there was a reduction of 80% in erroneous variant detection with the Torrent Variant Caller. Also, an enhancement was observed in de novo assembly with a more confident result in whole-genome MLST, with up to 96% of the alleles assembled correctly for both tested microbial genomes. All of these advantages result in a final genome sequence closer to the performance with MiSEQ and will contribute to turn comparative genomic analysis a reliable task. PMID:27033417

  9. Amorphous Fe2O3 nanoshells coated on carbonized bacterial cellulose nanofibers as a flexible anode for high-performance lithium ion batteries

    Science.gov (United States)

    Huang, Yang; Lin, Zixia; Zheng, Mingbo; Wang, Tianhe; Yang, Jiazhi; Yuan, Fanshu; Lu, Xiaoyu; Liu, Lin; Sun, Dongping

    2016-03-01

    A three-dimensional (3D) carbonaceous aerogel derived from biomass bacterial cellulose (BC) is introduced as a flexible framework for iron oxides in Li-ion batteries (LIBs). The 3D carbonized BC (CBC) with highly interconnected nanofibrous structure exhibits good electrical conductivity and mechanical stability. The amorphous Fe2O3 is tightly coated on the nanofibers of CBC through a simple in situ thermal decomposition method. The obtained amorphous Fe2O3 anode (denoted as A-Fe2O3@CBC) exhibits stable cycling performance and high rate capability when assembled into a half-cell, which is supposed to benefit from the well-dispersed Fe2O3 nanoshells and the hierarchical pores in A-Fe2O3@CBC composite. The rational design of the nanostructure could improve the transportation of electrons/ions and effectively alleviate volume changes of Fe2O3 during the electrochemical cycling. Meanwhile, the amorphous nature of the Fe2O3 in anode provides an enhanced capacitive-like lithium storage and flexible structure of the active materials, resulting in much higher specific capacity and longer cycle life when compared with its crystalline counterpart. This work provides a promising approach to design and construct the flexible metal oxide anode materials based on 3D carbonaceous aerogel for high-performance LIBs.

  10. Adsorptive bubble separation of zinc and cadmium cations in presence of ferric and aluminum hydroxides.

    Science.gov (United States)

    Jurkiewicz, Kazimierz

    2005-06-15

    The adsorptive bubble separation of zinc and cadmium cations from solution in the presence of ferric and aluminum hydroxides was carried out by means of Tween 80 (nonionic surfactant), and sodium laurate and stearate (anionic surfactants). The mechanism of metal removal is different depending on the nature of the surfactant used. The removal of zinc cations by adsorbing colloid flotation is higher than that of cadmium cations. It increases with increases in the amount of hydroxide precipitate and the concentration of Tween 80. The removal of zinc cations by ion flotation is lower than that of cadmium cations. It does not change with increases in the hydroxide amount. It increases, however, with increased sodium laurate or stearate concentration. Both separation methods turned out to be helpful for studying both the solution's structure and the interactions at the solution-solid interface. PMID:15897071

  11. Room temperature synthesis of hydrated nickel(III) oxide and study of its effect on Cr(VI) ions removal and bacterial culture

    Science.gov (United States)

    Dey, Sayan; Bhattacharjee, Swarupananda; Bose, Raj Shekhar; Ghosh, Chandan Kr.

    2015-06-01

    Cr(VI) ion is a toxic inorganic affluent that causes carcinogenic effects on the human body. Another problem that requires immediate attention is the fouling of water borne metal surface by micro-organisms. The present study aims to suggest the synthesis of Ni2O3·H2O nanoparticles and to investigate its heavy metal adsorption capacity and bacteriotoxicity in order to address the current global problems. Stable Ni2O3·H2O nanoparticles having various particle sizes were synthesized using active halogenation of nickel(II) precursor at different temperatures. Phase purity was investigated by X-ray diffraction technique. Due to high surface area, surface heterogeneity and surface polarity, they show excellent adsorption affinity (up to 73.9 % removal capacity) of heavy metal ions like Cr(VI). Adsorption isotherms (Freundlich and Langmuir) are plotted for them. Kinetics of the adsorption process reveals it to be pseudo-first-order kinetic in nature. They are also found to be fairly toxic to bacterial subcultures. Maximum value of the minimum inhibitory concentration and minimum bactericidal concentration were found to be ~0.54 and 0.58 mg/l for particles synthesized at 70 °C. It was observed that Cr(VI) adsorption highly depends on the surface heterogeneity, while the bactericidal effect depends on the size of the nanoparticles so-prepared. Hence, the prepared particles could be used as a potential material for Cr(VI) ion removal and as an antifouling agent.

  12. Intravenous ferric carboxymaltose accelerates erythropoietic recovery from experimental malarial anemia

    DEFF Research Database (Denmark)

    Maretty, Lasse; Sharp, Rebecca Emilie; Andersson, Mikael;

    2012-01-01

    Iron restriction has been proposed as a cause of erythropoietic suppression in malarial anemia; however, the role of iron in malaria remains controversial, because it may increase parasitemia. To investigate the role of iron-restricted erythropoiesis, A/J mice were infected with Plasmodium chabaudi...... use of iron therapy in malaria and show the need for trials of intravenous ferric carboxymaltose as an adjunctive treatment for severe malarial anemia....

  13. Preparation of polymeric aluminium ferric chloride from bauxite tailings

    OpenAIRE

    Ma D; Guo M; Zhang M

    2013-01-01

    Bauxite tailings are the main solid wastes in the ore dressing process. The Al2O3 and Fe2O3 contents in bauxite tailings can reach 50% and 13% respectively. The present study proposed a feasible method to use bauxite tailings to prepare polymeric aluminium ferric chloride (PAFC), a new composite inorganic polymer for water purification. Bauxite tailings roasted reacting with hydrochloric acid under air, pickle liquor which mainly contains Fe3+, Al3+ was generated, then calcium aluminate...

  14. Ferric citrate controls phosphorus and delivers iron in patients on dialysis.

    Science.gov (United States)

    Lewis, Julia B; Sika, Mohammed; Koury, Mark J; Chuang, Peale; Schulman, Gerald; Smith, Mark T; Whittier, Frederick C; Linfert, Douglas R; Galphin, Claude M; Athreya, Balaji P; Nossuli, A Kaldun Kaldun; Chang, Ingrid J; Blumenthal, Samuel S; Manley, John; Zeig, Steven; Kant, Kotagal S; Olivero, Juan Jose; Greene, Tom; Dwyer, Jamie P

    2015-02-01

    Patients on dialysis require phosphorus binders to prevent hyperphosphatemia and are iron deficient. We studied ferric citrate as a phosphorus binder and iron source. In this sequential, randomized trial, 441 subjects on dialysis were randomized to ferric citrate or active control in a 52-week active control period followed by a 4-week placebo control period, in which subjects on ferric citrate who completed the active control period were rerandomized to ferric citrate or placebo. The primary analysis compared the mean change in phosphorus between ferric citrate and placebo during the placebo control period. A sequential gatekeeping strategy controlled study-wise type 1 error for serum ferritin, transferrin saturation, and intravenous iron and erythropoietin-stimulating agent usage as prespecified secondary outcomes in the active control period. Ferric citrate controlled phosphorus compared with placebo, with a mean treatment difference of -2.2±0.2 mg/dl (mean±SEM) (P<0.001). Active control period phosphorus was similar between ferric citrate and active control, with comparable safety profiles. Subjects on ferric citrate achieved higher mean iron parameters (ferritin=899±488 ng/ml [mean±SD]; transferrin saturation=39%±17%) versus subjects on active control (ferritin=628±367 ng/ml [mean±SD]; transferrin saturation=30%±12%; P<0.001 for both). Subjects on ferric citrate received less intravenous elemental iron (median=12.95 mg/wk ferric citrate; 26.88 mg/wk active control; P<0.001) and less erythropoietin-stimulating agent (median epoetin-equivalent units per week: 5306 units/wk ferric citrate; 6951 units/wk active control; P=0.04). Hemoglobin levels were statistically higher on ferric citrate. Thus, ferric citrate is an efficacious and safe phosphate binder that increases iron stores and reduces intravenous iron and erythropoietin-stimulating agent use while maintaining hemoglobin. PMID:25060056

  15. Synthesis and magnetic properties of magnetite-silicate nanocomposites derived from iron oxide of bacterial origin

    International Nuclear Information System (INIS)

    Magnetic nanocomposites containing magnetite (Fe3O4) nanoparticles were prepared from iron oxide microtubules produced by Leptothrix ochracea, a species of water-habitant iron-oxidizing bacteria. The microtubules were mainly composed of Si-containing ferric hydroxide that shows a broad X-ray diffraction pattern similar to that of 2-line ferrihydrite. After moderate heat treatment in a reductive atmosphere above 325 °C, the ferric ions were partially reduced to a ferrous state, and nanocrystalline Fe3O4 with a spinel-type structure was formed in a noncrystalline silicate matrix. The average crystallite size of the Fe3O4 nanoparticles was estimated to be in the order of a few nanometers. The sample heat-treated at 500 °C exhibited considerable magnetization together with superparamagnetic behavior at room temperature, and super-spin-glass interaction occurred at low temperature. On further heat treatment above 530 °C, Fe3O4 was reduced to wüstite (Fe1−xO) and finally crystallized into iron metal (α-Fe) and ferrous silicate (Fe2SiO4). -- Highlights: ► Iron oxides of bacterial origin are unique sources of magnetic nanocomposites. ► Fe3O4 nanoparticles with silicates were formed by reduction of the bacterial iron oxide. ► The sample heat-treated at 500 °C was a magnetic nanocomposite of Fe3O4 and amorphous silicate. ► It exhibits unique magnetic properties including superparamagnetism and super-spin-glass states.

  16. Modeling of ferric sulfate decomposition and sulfation of potassium chloride during grate‐firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Jappe Frandsen, Flemming;

    2013-01-01

    Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe the...... process. The yields of sulfur oxides from ferric sulfate decomposition under boiler conditions are investigated experimentally, revealing a distribution of approximately 40% SO3 and 60% SO2. The ferric sulfate decomposition model is combined with a detailed kinetic model of gas‐phase KCl sulfation and a...... model of K2SO4 condensation to simulate the sulfation of KCl by ferric sulfate addition. The simulation results show good agreements with experiments conducted in a biomass grate‐firing reactor. The results indicate that the SO3 released from ferric sulfate decomposition is the main contributor to KCl...

  17. Thermodynamic modeling of ferric phosphate precipitation for phosphorus removal and recovery from wastewater

    International Nuclear Information System (INIS)

    Phosphorus removal and recovery by ferric phosphate (FePO4.2H2O) precipitation has been considered as an effective technology. In the present study, we examined chemical precipitation thermodynamic modeling of the PHREEQC program for phosphorus removal and recovery from wastewater. The objective of this research was to employ thermodynamic modeling to evaluate the effect of solution factors on FePO4.2H2O precipitation. In order to provide comparison, with the evaluation of thermodynamic modeling, the case study of phosphate removal from anaerobic supernatant was studied. The results indicated that the saturation-index (SI) of FePO4.2H2O followed a polynomial function of pH, and the solution pH influenced the ion activities of ferric iron salts and phosphate. The SI of FePO4.2H2O increased with a logarithmic function of Fe3+:PO43- molar ratio (Fe/P) and initial PO43- concentration, respectively. Furthermore, the SI of FePO4.2H2O decreased with a logarithmic function of alkalinity and ionic strength, respectively. With an increase in temperature, the SI at pH 6.0 and 9.0 decreased with a linear function, and the SI at pH 4.0 followed a polynomial function. For the case study of phosphate removal from anaerobic supernatant, the phosphate removal trend at different pH and Fe/P was closer to the predictions of thermodynamic modeling. The results indicated that the thermodynamic modeling of FePO4.2H2O precipitation could be utilized to predict the technology parameters for phosphorus removal and recovery.

  18. Thermodynamic modeling of ferric phosphate precipitation for phosphorus removal and recovery from wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Tao; Ding Lili [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu (China); Ren Hongqiang, E-mail: hqren@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu (China); Guo Zhitao; Tan Jing [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu (China)

    2010-04-15

    Phosphorus removal and recovery by ferric phosphate (FePO{sub 4}.2H{sub 2}O) precipitation has been considered as an effective technology. In the present study, we examined chemical precipitation thermodynamic modeling of the PHREEQC program for phosphorus removal and recovery from wastewater. The objective of this research was to employ thermodynamic modeling to evaluate the effect of solution factors on FePO{sub 4}.2H{sub 2}O precipitation. In order to provide comparison, with the evaluation of thermodynamic modeling, the case study of phosphate removal from anaerobic supernatant was studied. The results indicated that the saturation-index (SI) of FePO{sub 4}.2H{sub 2}O followed a polynomial function of pH, and the solution pH influenced the ion activities of ferric iron salts and phosphate. The SI of FePO{sub 4}.2H{sub 2}O increased with a logarithmic function of Fe{sup 3+}:PO{sub 4}{sup 3-} molar ratio (Fe/P) and initial PO{sub 4}{sup 3-} concentration, respectively. Furthermore, the SI of FePO{sub 4}.2H{sub 2}O decreased with a logarithmic function of alkalinity and ionic strength, respectively. With an increase in temperature, the SI at pH 6.0 and 9.0 decreased with a linear function, and the SI at pH 4.0 followed a polynomial function. For the case study of phosphate removal from anaerobic supernatant, the phosphate removal trend at different pH and Fe/P was closer to the predictions of thermodynamic modeling. The results indicated that the thermodynamic modeling of FePO{sub 4}.2H{sub 2}O precipitation could be utilized to predict the technology parameters for phosphorus removal and recovery.

  19. Ferric and cobaltous hydroacid complexes for forward osmosis (FO) processes

    KAUST Repository

    Ge, Qingchun

    2014-07-01

    Cupric and ferric hydroacid complexes have proven their advantages as draw solutes in forward osmosis in terms of high water fluxes, negligible reverse solute fluxes and easy recovery (Ge and Chung, 2013. Hydroacid complexes: A new class of draw solutes to promote forward osmosis (FO) processes. Chemical Communications 49, 8471-8473.). In this study, cobaltous hydroacid complexes were explored as draw solutes and compared with the ferric hydroacid complex to study the factors influencing their FO performance. The solutions of the cobaltous complexes produce high osmotic pressures due to the presence of abundant hydrophilic groups. These solutes are able to dissociate and form a multi-charged anion and Na+ cations in water. In addition, these complexes have expanded structures which lead to negligible reverse solute fluxes and provide relatively easy approaches in regeneration. These characteristics make the newly synthesized cobaltous complexes appropriate as draw solutes. The FO performance of the cobaltous and ferric-citric acid (Fe-CA) complexes were evaluated respectively through cellulose acetate membranes, thin-film composite membranes fabricated on polyethersulfone supports (referred as TFC-PES), and polybenzimidazole and PES dual-layer (referred as PBI/PES) hollow fiber membranes. Under the conditions of DI water as the feed and facing the support layer of TFC-PES FO membranes (PRO mode), draw solutions at 2.0M produced relatively high water fluxes of 39-48 LMH (Lm-2hr-1) with negligible reverse solute fluxes. A water flux of 17.4 LMH was achieved when model seawater of 3.5wt.% NaCl replaced DI water as the feed and 2.0M Fe-CA as the draw solution under the same conditions. The performance of these hydroacid complexes surpasses those of the synthetic draw solutes developed in recent years. This observation, along with the relatively easy regeneration, makes these complexes very promising as a novel class of draw solutes. © 2014 Elsevier Ltd.

  20. Passive Immunization by Recombinant Ferric Enterobactin Protein (FepA from Escherichia Coli O157

    Directory of Open Access Journals (Sweden)

    Seyed Mehdi Larrie-Baghal

    2013-06-01

    Full Text Available Background: Enterohemorrhagic Escherichia coli (EHEC O157:H7 has been recognized as a major food borne pathogen responsible for frequent hemorrhagic colitis and hemolytic uremic syndrome in humans. Cattle are important reservoirs of E. coli O157:H7, in which the organism colonizes the intestinal tract and is shed in the feces.Objective: Vaccination of cattle has significant potential as a pre-harvest intervention strategy for E. coli O157:H7. The aim of this study was to evaluate active and passive immunization against E. coli O157:H7 using a recombinant protein.Materials and Methods: The recombinant FepA protein induced by IPTG was purified by nickel affinity chromatography. Antibody titre was determined by ELISA in FepA immunized rabbits sera. Sera collected from vaccinated animals were used for bacterial challenge in passive immunization studies.Results: The results demonstrate that passive immunization with serum raised against FepA protects rabbits from subsequent infection.Conclusion: Significant recognition by the antibody of ferric enterobactin binding protein may lead to its application in the restriction of Enterobacteriaceae propagation.

  1. An update on iron acquisition by Legionella pneumophila: new pathways for siderophore uptake and ferric iron reduction

    Science.gov (United States)

    Cianciotto, Nicholas P

    2015-01-01

    Iron acquisition is critical for the growth and pathogenesis of Legionella pneumophila, the causative agent of Legionnaires’ disease. L. pneumophila utilizes two main modes of iron assimilation, namely ferrous iron uptake via the FeoB system and ferric iron acquisition through the action of the siderophore legiobactin. This review highlights recent studies concerning the mechanism of legiobactin assimilation, the impact of c-type cytochromes on siderophore production, the importance of legiobactin in lung infection and a newfound role for a bacterial pyomelanin in iron acquisition. These data demonstrate that key aspects of L. pneumophila iron acquisition are significantly distinct from those of long-studied, ‘model’ organisms. Indeed, L. pneumophila may represent a new paradigm for a variety of other intracellular parasites, pathogens and under-studied bacteria. PMID:26000653

  2. Mutagenesis of the N- and C-terminal cysteine pairs of Tn501 mercuric ion reductase: Consequences for bacterial detoxification of mercurials

    International Nuclear Information System (INIS)

    Mercuric ion reductase (the mer A gene product) is a unique member of the class of FAD and redox-active disulfide-containing oxidoreductases by virtue of its ability to reduce Hg(II) to Hg(0) as the last step in bacterial detoxification of mercurials. In addition to the active site redox-active disulfide, formed between Cys135 and Cys140 in Tn501 MerA, the protein products of the three mer A gene sequences published to data have two additional conserved pairs of cysteines, one near the N-terminus (Cys10Cys13 in Tn501 MerA) and another near the C-terminus (Cys588Cys559 in Tn501 MerA). Neither of these pairs is found in other members of this enzyme family. To assess the possible roles of these peripheral cysteines in the Hg(II) detoxification pathway, the authors have constructed and characterized one single mutant, Cys10Ala13, and two double mutants, Ala10Ala13 and Ala558Ala559. The N-terminal mutants are fully functional in vivo as determined by HgCl2 resistance studies, showing the N-terminal cysteine pair to be dispensable. In contrast, the Ala558Ala559 mutant is defective for HgCl2 resistance in vivo and Hg(SR)2 reduction in vitro, thereby implicating Cys558 and/or Cys559 in Hg(II) reduction by the wild-type enzyme. Other activities, such as NADPH/thio-NADP+ transhydrogenation, NADPH oxidation, and DTNB reduction, are unimpaired in this mutant

  3. Absorption mechanisms for cationic and anionic mineral species on ferric iron polymer hydroxides and oxidation products of ferrous iron in aqueous media

    International Nuclear Information System (INIS)

    Adsorbents obtained by hydrolysing the Fe3+, 6H2O ion are made of polymers with aquo (H2O), hydroxo (-OH...) and oxo (...O...) ligands. Radioactive tracers reveal the importance of chemical mechanisms in adsorption phenomena on ferric oxide in aqueous media. Zn2+, Co2+ and Mn2+ cations are exchanged with hydrogen from hydroxo groups. CrO42-, SeO32- and Sb(OH)6- anions form covalent associations in place of iron ligands. The adsorption of hydrolyzed ions results in strong oxygen bridge bonds. In fresh water, Co and Mn participate alone in physical electrostatic adsorption. Iron II oxidation products generate chemical adsorptions. Zn2+ and Sb(OH)6- associate with ferric hydroxides from oxidized Fe2+. 60Co, 54Mn and 51Cr form covalent associations between unpaired 3d iron electrons and the adsorbed element. This process is not predominant with selenium IV or VI reduced to the metallic state or fixed on ferric hydroxide in the selenite form. These conclusions can be applied to pollutant analysis and to water purification and contribute to our understanding of the role of iron in the distribution of oligo-elements in aqueous media. (author)

  4. 76 FR 17556 - Sodium Ferric Ethylenediaminetetraacetate; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2011-03-30

    ... Findings In the Federal Register of September 30, 2010 (75 FR 60452) (FRL- 8837-2), EPA issued a notice... irritating (MRID No. 47942510) and a skin sensitization study showed that sodium ferric EDTA is not a sensitizer to the skin (MRID No. 47942511). Accordingly, EPA has determined that sodium ferric EDTA...

  5. Ferric oxide quantum dots in stable phosphate glass system and their magneto-optical study

    International Nuclear Information System (INIS)

    Graphical abstract: We report synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles (NCs) content on the optical and magneto-optical properties of the glasses. Faraday rotation of the glass nanocomposites was measured and showed variation in Verdet constant with concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and there is a threefold enhancement in the Verdet constant of ferric oxide quantum dot-glass nanocomposite. Highlights: ► We synthesize ferric oxide embedded low melting stable phosphate glass nanocomposite. ► Glasses doped with 0.25 and 2% ferric oxide show particle size in the range of 4–12 nm. ► The host phosphate glass itself shows fairly good Verdet constant (11.5°/T cm). ► Glasses doped with 0.25% ferric oxide show high Verdet constant (30.525°/T cm). ► The as synthesis glasses may have potential application in magneto optical devices. -- Abstract: Herein, we report the synthesis of ferric oxide embedded low melting phosphate glass nanocomposite and also the effect of ferric oxide nanoparticles content on the optical and magneto-optical properties of the glasses. The optical study clearly showed red shift in optical cut off with increasing ferric oxide concentration. The band gap of the host glass was observed to be 3.48 eV and it shifted to 3.14 eV after doping with ferric oxide. The glasses doped with 0.25 and 2% ferric oxide showed particle size of 4–6 nm and 8–12 nm, respectively. Faraday rotation of the glass nanocomposites was measured and showed variation in the Verdet constant as per increasing concentration of ferric oxide. Interestingly, the host glass itself showed fairly good Verdet constant (11.5°/T cm) and threefold enhancement was observed in the Verdet constant of ferric oxide quantum dot-glass nanocomposite.

  6. Modeling of sulfation of potassium chloride by ferric sulfate addition during grate-firing of biomass

    DEFF Research Database (Denmark)

    Wu, Hao; Jespersen, Jacob Boll; Aho, Martti;

    2013-01-01

    Potassium chloride, KCl, formed from critical ash-forming elements released during combustion may lead to severe ash deposition and corrosion problems in biomass-fired boilers. Ferric sulfate, Fe2(SO4)3 is an effective additive, which produces sulfur oxides (SO2 and SO3) to convert KCl to the less...... order to simulate the sulfation of KCl by ferric sulfate addition during grate-firing of biomass. The simulation results show good agreements with the experimental data obtained in a pilot-scale biomass grate-firing reactor, where different amounts of ferric sulfate was injected on the grate or into the...... freeboard. In addition, the simulations of elemental sulfur addition on the grate fit well with the experimental data. The results suggest that the SO3 released from ferric sulfate decomposition is the main contributor to KCl sulfation, and that the effectiveness of the ferric sulfate addition is sensitive...

  7. Arsenic removal from acidic solutions with biogenic ferric precipitates.

    Science.gov (United States)

    Ahoranta, Sarita H; Kokko, Marika E; Papirio, Stefano; Özkaya, Bestamin; Puhakka, Jaakko A

    2016-04-01

    Treatment of acidic solution containing 5g/L of Fe(II) and 10mg/L of As(III) was studied in a system consisting of a biological fluidized-bed reactor (FBR) for iron oxidation, and a gravity settler for iron precipitation and separation of the ferric precipitates. At pH 3.0 and FBR retention time of 5.7h, 96-98% of the added Fe(II) precipitated (99.1% of which was jarosite). The highest iron oxidation and precipitation rates were 1070 and 28mg/L/h, respectively, and were achieved at pH 3.0. Subsequently, the effect of pH on arsenic removal through sorption and/or co-precipitation was examined by gradually decreasing solution pH from 3.0 to 1.6 (feed pH). At pH 3.0, 2.4 and 1.6, the highest arsenic removal efficiencies obtained were 99.5%, 80.1% and 7.1%, respectively. As the system had ferric precipitates in excess, decreased arsenic removal was likely due to reduced co-precipitation at pH<2.4. As(III) was partially oxidized to As(V) in the system. In shake flask experiments, As(V) sorbed onto jarosite better than As(III). Moreover, the sorption capacity of biogenic jarosite was significantly higher than that of synthetic jarosite. The developed bioprocess simultaneously and efficiently removes iron and arsenic from acidic solutions, indicating potential for mining wastewater treatment. PMID:26705889

  8. Ferric oxide nanoparticles decorated carbon nanotubes and carbon nanofibers: From synthesis to enhanced removal of phenol

    Directory of Open Access Journals (Sweden)

    Hamza A. Asmaly

    2015-09-01

    Full Text Available In this work, ferric oxide nanoparticle decorated carbon fibers and carbon nanotubes (CNF/Fe2O3 and CNT/Fe2O3 were synthesized and characterized by scanning electron microscopy (SEM, thermogravimetric analysis (TGA, energy dispersive X-ray spectroscopy (EDS, transmission electron microscopy (TEM, X-ray diffraction (XRD, zeta potential and BET surface area analyzer. The prepared nanocomposites were evaluated or the removal of phenol ions from aqueous solution. The effects of experimental parameters, such as shaking speed, pH, contact time, adsorbent dosage and initial concentration, were evaluated for the phenol removal efficiency. The adsorption experimental data were represented by both the Langmuir and Freundlich isotherm models. The Langmuir isotherm model best fitted the data on the adsorption of phenol, with a high correlation coefficient. The adsorption capacities, as determined by the Langmuir isotherm model were 0.842, 1.098, 1.684 and 2.778 mg/g for raw CNFs, raw CNTs, CNF–Fe2O3 and CNT–Fe2O3, respectively.

  9. Removal of the blue 1 dye of aqueous solutions using ferric zeolite

    International Nuclear Information System (INIS)

    amount of adsorbent from 10 to 200 mg of adsorbent and 10 ml of solution. Finally there was a column sorption test, obtaining the curve os load vs time of contact, and important design parameters such as the rupture time, it was at 100 minutes, with an initial concentration of 5 mg/L taking final concentration breakpoint of 0.4 mg/L, the results were evaluated with the Thomas model. The results of this work can conclude that it is possible to extend the scope of natural zeolites as adsorbents for the removal of organic pollutants in wastewater, by changing its outer surface with ferric chloride, without a significant effect on their ion exchange properties. (Author)

  10. Mössbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

    Science.gov (United States)

    Jaén, Juan A.; Navarro, César

    2009-07-01

    Fourier transform infrared spectroscopy and Mössbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Mössbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

  11. Moessbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

    Energy Technology Data Exchange (ETDEWEB)

    Jaen, Juan A., E-mail: jjaen@ancon.up.ac.p [Universidad de Panama, Depto. de Quimica Fisica, CITEN, Lab. No. 105, Edificio de Laboratorios Cientificos-VIP (Panama); Navarro, Cesar [Universidad de Panama, Escuela de Quimica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama)

    2009-07-15

    Fourier transform infrared spectroscopy and Moessbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Moessbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

  12. Ferric Citrate Transport of Escherichia coli: Functional Regions of the FecR Transmembrane Regulatory Protein

    OpenAIRE

    Welz, Dietrich; Braun, Volkmar

    1998-01-01

    Transcription of the ferric citrate transport genes of Escherichia coli is induced by ferric citrate bound to the outer membrane receptor FecA. Additional ferric citrate-specific regulatory proteins are FecR in the cytoplasmic membrane and the FecI sigma factor in the cytoplasm. To further understand the assumed FecR-mediated signal transduction across the cytoplasmic membrane, the transmembrane topology of FecR (317 amino acids) was determined with hybrid proteins containing portions of FecR...

  13. The absorption and transportation of ferric-salt in apple trees

    International Nuclear Information System (INIS)

    59Fe tracer technique was used to study the ferric-salt absorption, utilization and transportation in apple trees. The results indicated that absorption and utilization rate of ferric salt was 0.056%∼0.110% for roots and 30% for leaves, and that Fe is not easily to be transferred from one part to another. Fulvic acid iron had a better effect than ferrous sulfate. Ferric-salt absorption, utilization and transference were different among the cultivars. Intensive injections of ferrous salt into the apple trunks seemed to be more effective for correcting of chlorosis

  14. Moessbauer and infrared spectroscopy as a diagnostic tool for the characterization of ferric tannates

    International Nuclear Information System (INIS)

    Fourier transform infrared spectroscopy and Moessbauer spectroscopy are use for the characterization and qualitative analysis of hydrolysable and condensed tannates. The two classes of tannates may be differentiated from the characteristic IR pattern. Moessbauer proof that a mixture of mono- and bis-type ferric tannate complexes, and an iron(II)-tannin complex are obtained from the interaction of hydrolysable tannins (tannic acid and chestnut tannin) and condensed tannins (mimosa and quebracho) with a ferric nitrate solution. At pH 7, a partially hydrolyzed ferric tannate complex was also obtained.

  15. Ferric dicitrate transport system (Fec) of Shigella flexneri 2a YSH6000 is encoded on a novel pathogenicity island carrying multiple antibiotic resistance genes.

    Science.gov (United States)

    Luck, S N; Turner, S A; Rajakumar, K; Sakellaris, H; Adler, B

    2001-10-01

    Iron uptake systems which are critical for bacterial survival and which may play important roles in bacterial virulence are often carried on mobile elements, such as plasmids and pathogenicity islands (PAIs). In the present study, we identified and characterized a ferric dicitrate uptake system (Fec) in Shigella flexneri serotype 2a that is encoded by a novel PAI termed the Shigella resistance locus (SRL) PAI. The fec genes are transcribed in S. flexneri, and complementation of a fec deletion in Escherichia coli demonstrated that they are functional. However, insertional inactivation of fecI, leading to a loss in fec gene expression, did not impair the growth of the parent strain of S. flexneri in iron-limited culture media, suggesting that S. flexneri carries additional iron uptake systems capable of compensating for the loss of Fec-mediated iron uptake. DNA sequence analysis showed that the fec genes are linked to a cluster of multiple antibiotic resistance determinants, designated the SRL, on the chromosome of S. flexneri 2a. Both the SRL and fec loci are carried on the 66,257-bp SRL PAI, which has integrated into the serX tRNA gene and which carries at least 22 prophage-related open reading frames, including one for a P4-like integrase. This is the first example of a PAI that carries genes encoding antibiotic resistance and the first report of a ferric dicitrate uptake system in Shigella. PMID:11553538

  16. Arsenic Adsorption Equilibrium Concentration and Adsorption Rate of Activated Carbon Coated with Ferric-Aluminum Hydroxides

    Science.gov (United States)

    Zhang, M.; Sugita, H.; Oguma, T.; Hara, J.; Takahashi, S.

    2015-12-01

    In some areas of developing countries, ground or well water contaminated with arsenic has been reluctantly used as drinking water. It is highly desirable that effective and inexpensive arsenic removal agents should be developed and provided to reduce the potential health risk. Previous studies demonstrated that activated carbon coated with ferric-aluminum hydroxides (Fe-Al-C) has high adsorptive potential for removal of arsenic. In this study, a series of experiments using Fe-Al-C were carried to discuss adsorption equilibrium time, adsorption equilibrium concentration and adsorption rate of arsenic for Fe-Al-C. Fe-Al-C used in this study was provided by Astec Co., Ltd. Powder reagent of disodium hydrogen arsenate heptahydrate was dissolved into ion-exchanged water. The solution was then further diluted with ion-exchanged water to be 1 and 10 mg/L as arsenic concentration. The pH of the solution was adjusted to be around 7 by adding HCl and/or NaOH. The solution was used as artificial arsenic contaminated water in two types of experiments (arsenic adsorption equilibrium and arsenic adsorption rate tests). The results of the arsenic equilibrium tests were showed that a time period of about 3 days to reach apparent adsorption equilibrium for arsenic. The apparent adsorption equilibrium concentration and adsorbed amount of arsenic on Fe-Al-C adsorbent could be estimated by application of various adsorption isotherms, but the distribution coefficient of arsenic between solid and liquid varies with experimental conditions such as initial concentration of arsenic and addition concentration of adsorbent. An adsorption rate equation that takes into account the reduction in the number of effective adsorption sites on the adsorbent caused by the arsenic adsorption reaction was derived based on the data obtained from the arsenic adsorption rate tests.

  17. Growth, spectroscopic and physicochemical properties of bis mercury ferric chloride tetra thiocyanate: A nonlinear optical crystal

    Science.gov (United States)

    Ramesh, V.; Shihabuddeen Syed, A.; Jagannathan, K.; Rajarajan, K.

    2013-05-01

    Single crystal of bis mercury ferric chloride tetra thiocyanate [Hg2FeCl3(SCN)4; (MFCTC)] was grown from ethanol-water (3:1) mixed solvent using slow evaporation solvent technique (SEST) for the first time. The cell parameters of the grown crystal were confirmed by single crystal XRD. The coordination of transition metal ions with the SCN ligand is well-identified using FT-IR spectral analysis. The chemical composition of MFCTC was confirmed using CHNS elemental test. The ESR spectral profile of MFCTC was recorded from 298 K to 110 K, which strongly suggests the incorporation of Fe3+ ion and its environment with respect to SCN ligand. The HPLC chromatogram of MFCTC highlights the purity of the compound. The UV-Vis-NIR studies revealed the ultra violet cut-off wavelength of MFCTC in ethanol as 338 nm. The dielectric constant and dielectric loss of the sample were studied as a function of frequency and temperature. The TGA-DTA and DSC thermal analysis show that the sample is thermally stable up to 234.31 °C, which is comparatively far better than the thermal stability of Hg3CdCl2(SCN)6; (171.3 °C) and other metal-organic coordination complex crystals such as CdHg(SCN)4 (198.5 °C), Hg(N2H4CS)4Mn(SCN)4 (199.06 °C) and Hg(N2H4CS)4Zn(SCN)4 (185 °C). The SHG conversion efficiency of MFCTC is found to be higher than KDP.

  18. Dietary bioavailability of Cu adsorbed to colloidal hydrous ferric oxide

    Science.gov (United States)

    Cain, Daniel J.; Croteau, Marie-Noële; Fuller, Christopher C.

    2013-01-01

    The dietary bioavailability of copper (Cu) adsorbed to synthetic colloidal hydrous ferric oxide (HFO) was evaluated from the assimilation of 65Cu by two benthic grazers, a gastropod and a larval mayfly. HFO was synthesized, labeled with 65Cu to achieve a Cu/Fe ratio comparable to that determined in naturally formed HFO, and then aged. The labeled colloids were mixed with a food source (the diatom Nitzschia palea) to yield dietary 65Cu concentrations ranging from 211 to 2204 nmol/g (dry weight). Animals were pulse fed the contaminated diet and assimilation of 65Cu from HFO was determined following 1–3 days of depuration. Mass transfer of 65Cu from HFO to the diatom was less than 1%, indicating that HFO was the source of 65Cu to the grazers. Estimates of assimilation efficiency indicated that the majority of Cu ingested as HFO was assimilated (values >70%), implying that colloidal HFO potentially represents a source of dietary Cu to benthic grazers, especially where there is active formation and infiltration of these particles into benthic substrates.

  19. Iron fortification of flour with a complex ferric orthophosphate

    International Nuclear Information System (INIS)

    The unexpectedly low bioavailability in humans of elemental iron powder prompted us to search for other Fe compounds suitable for Fe fortification of flour that fulfill the two requirements of insolubility in water (due to high water content of flour) and good bioavailability in humans. Systematic studies of compatibility, solubility, and bioavailability led to this study of a microcrystalline complex ferric orthophosphate (CFOP), Fe3H8(NH4)-(PO4)6.6H2O, a well-defined compound. This compound was labeled with 59Fe, and the native Fe in meals was labeled with 55FeCl3. The ratio of absorbed 59Fe to absorbed 55Fe is a direct measure of the fraction of CFOP that joins the nonheme Fe pool and that is made potentially available for absorption. The relative bioavailability of CFOP varied from 30% to 60% when labeled wheat rolls were served with different meals. The CFOP meets practical requirements of an Fe fortificant for flour well, with regard to both compatibility and bioavailability in humans

  20. Preparation of polymeric aluminium ferric chloride from bauxite tailings

    Directory of Open Access Journals (Sweden)

    Ma D.

    2013-01-01

    Full Text Available Bauxite tailings are the main solid wastes in the ore dressing process. The Al2O3 and Fe2O3 contents in bauxite tailings can reach 50% and 13% respectively. The present study proposed a feasible method to use bauxite tailings to prepare polymeric aluminium ferric chloride (PAFC, a new composite inorganic polymer for water purification. Bauxite tailings roasted reacting with hydrochloric acid under air, pickle liquor which mainly contains Fe3+, Al3+ was generated, then calcium aluminate was used to adjust pH value and the basicity of the pickle liquor, the PAFC was subsequently prepared after the polymerization process. The optimal synthesizing parameters for the preparation of PAFC obtained were as follows: the concentration of hydrochloric acid of 24 wt%, ratio of hydrochloric acid to bauxite tailings of 6:1, temperature of 90ºC, leaching time of 2.5 hours, ration of pickle liquor to calcium aluminate of 12:1, polymerization temperature of 90ºC and polymerization time of about 3 hours. The basicity of PAFC was higher than 68%, the sum concentration of Al2O3 and Fe2O3 was beyond 12.5%. The results of flocculation tests indicate that the PAFC has a better performance of removing the turbidity of wastewater compared to PAC, and PAFC prepared by bauxite tailings is a kind of high quality flocculants.

  1. Toxicity of ferric chloride sludge to aquatic organisms.

    Science.gov (United States)

    Sotero-Santos, Rosana B; Rocha, Odete; Povinelli, Jurandyr

    2007-06-01

    Iron-rich sludge from a drinking water treatment plant (DWTP) was investigated regarding its toxicity to aquatic organisms and physical and chemical composition. In addition, the water quality of the receiving stream near the DWTP was evaluated. Experiments were carried out in August 1998, February 1999 and May 1999. Acute toxicity tests were carried out on a cladoceran (Daphnia similis), a midge (Chironomus xanthus) and a fish (Hyphessobrycon eques). Chronic tests were conducted only on D. similis. Acute sludge toxicity was not detected using any of the aquatic organisms, but chronic effects were observed upon the fecundity of D. similis. Although there were relatively few sample dates, the results suggested that the DWTP sludge had a negative effect on the receiving body as here was increased suspended matter, turbidity, conductivity, chemical oxygen demand (COD) and hardness in the water downstream of the DWTP effluent discharge. The ferric chloride sludge also exhibited high heavy metal concentrations revealing a further potential for pollution and harmful chronic effects on the aquatic biota when the sludge is disposed of without previous treatment. PMID:17416403

  2. Characterization of ferric arsenate-sulfate compounds: Implications for arsenic control in refractory gold processing residues

    Czech Academy of Sciences Publication Activity Database

    Paktunc, D.; Majzlan, J.; Palatinus, Lukáš; Dutrizac, J.; Klementová, Mariana; Poirier, G.

    2013-01-01

    Roč. 98, č. 4 (2013), s. 554-565. ISSN 0003-004X Institutional support: RVO:68378271 Keywords : arsenic * ferric arsenate sulfate * autoclave residue * hydrometallurgy Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.059, year: 2013

  3. Ferrous versus Ferric Oral Iron Formulations for the Treatment of Iron Deficiency: A Clinical Overview

    Directory of Open Access Journals (Sweden)

    Palacios Santiago

    2012-01-01

    Full Text Available Iron deficiency anaemia represents a major public health problem, particularly in infants, young children, pregnant women, and females with heavy menses. Oral iron supplementation is a cheap, safe, and effective means of increasing haemoglobin levels and restoring iron stores to prevent and correct iron deficiency. Many preparations are available, varying widely in dosage, formulation (quick or prolonged release, and chemical state (ferrous or ferric form. The debate over the advantages of ferrous versus ferric formulations is ongoing. In this literature review, the tolerability and efficacy of ferrous versus ferric iron formulations are evaluated. We focused on studies comparing ferrous sulphate preparations with ferric iron polymaltose complex preparations, the two predominant forms of iron used. Current data show that slow-release ferrous sulphate preparations remain the established and standard treatment of iron deficiency, irrespective of the indication, given their good bioavailability, efficacy, and acceptable tolerability demonstrated in several large clinical studies.

  4. Preparation of ferric-activated sludge-based adsorbent from biological sludge for tetracycline removal.

    Science.gov (United States)

    Yang, Xin; Xu, Guoren; Yu, Huarong; Zhang, Zhao

    2016-07-01

    Ferric activation was novelly used to produce sludge-based adsorbent (SBA) from biological sludge through pyrolysis, and the adsorbents were applied to remove tetracycline from aqueous solution. The pyrolysis temperature and mass ratio (activator/dried sludge) greatly influenced the surface area and pore characteristics of SBA. Ferric activation could promote the porous structure development of adsorbents, and the optimum preparation conditions were pyrolysis temperature 750°C and mass ratio (activator/dried sludge) 0.5. In batch experiments, ferric-activated SBA showed a higher adsorption capacity for tetracycline than non-activated SBA, because the enhanced mesoporous structure favored the diffusion of tetracycline into the pores, the iron oxides and oxygen-containing functional groups in the adsorbents captured tetracycline by surface complexation. The results indicate that ferric activation is an effective approach for preparing adsorbents from biological sludge to remove tetracycline, providing a potential option for waste resource recovery. PMID:27038265

  5. Granulation and ferric oxides loading enable biochar derived from cotton stalk to remove phosphate from water.

    Science.gov (United States)

    Ren, Jing; Li, Nan; Li, Lei; An, Jing-Kun; Zhao, Lin; Ren, Nan-Qi

    2015-02-01

    Granulation of biochar powder followed by immobilization of ferric oxides on the macroporous granular biochar (Bg-FO-1) substantially enhanced phosphate removal from water. BET analysis confirmed that both granulation and ferric oxides loading can increase the surface areas and pore volumes effectively. Bg-FO-1 was proven to be a favorable adsorbent for phosphate. The phosphate adsorption capacity was substantially increased from 0 mg/g of raw biochar powder to 0.963 mg/g (Bg-FO-1). When the ferric oxides loading was prior to granulation, the adsorption capacity was decreased by 59-0.399 mg/g, possibly due to the decrease of micropore and mesopore area as well as the overlaying of binders to the activated sites produced by ferric oxides. PMID:25446788

  6. Ion diffusion modelling of Fricke-agarose dosemeter gels

    International Nuclear Information System (INIS)

    In Fricke-agarose gels, an accurate determination of the spatial dose distribution is hindered by the diffusion of ferric ions. In this work, a model was developed to describe the diffusion process within gel samples of finite length and, thus, permit the reconstruction of the initial spatial distribution of the ferric ions. The temporal evolution of the ion concentration as a function of the initial concentration is derived by solving Fick's second law of diffusion in two dimensions with boundary reflections. The model was applied to magnetic resonance imaging data acquired at high spatial resolution (0.3 mm) and was found to describe accurately the observed diffusion effects. (authors)

  7. 乙二胺螯合细菌纤维素的制备及其吸附Cu2+研究%Preparation of ethylenediamine chelating bacterial cellulose for the adsorption of copper ions

    Institute of Scientific and Technical Information of China (English)

    马波; 孙东平; 朱春林; 刘长生; 牛会君

    2009-01-01

    以细菌纤维素为原料制备乙二胺螯合细菌纤维素.通过红外光谱仪、元素分析仪对产物进行了表征.研究了乙二胺螯合细菌纤维素对铜离子的吸附动力学、等温吸附等特征.结果表明,吸附动力学可用拟二级速度方程来描述,吸附平衡符合Freundlich等温吸附方程,并对其吸附与解吸性能进行了分析.%Ethylenediamine chelating bacterial cellulose has been synthesized by bacterial cellulose. The product is characterized by the infra-red spectroscopy and elemental analyser. Its characteristics, such as adsorption kinetics and adsorption isotherms for copper ions are studied. The results show that the adsorption kinetics can be described by pseudo-second-level velocity equation. The adsorption equilibrium accords with Freundlich isotherm adsorption equation. The adsorption and desorption properties of ethylenediamine chelating bacterial cellulose are also analyzed.

  8. Prediction of ferric iron precipitation in bioleaching process using partial least squares and artificial neural network

    OpenAIRE

    Golmohammadi Hassan; Rashidi Abbas; Safdari Seyed Jaber

    2013-01-01

    A quantitative structure-property relationship (QSPR) study based on partial least squares (PLS) and artificial neural network (ANN) was developed for the prediction of ferric iron precipitation in bioleaching process. The leaching temperature, initial pH, oxidation/reduction potential (ORP), ferrous concentration and particle size of ore were used as inputs to the network. The output of the model was ferric iron precipitation. The optimal condition of the neural network was obtained by...

  9. Protective Effect of Punica granatum on Ferric Nitrilotriacetate-Induced Toxicity in Oreochromis niloticus

    OpenAIRE

    Piya KOSAI; Wipaphorn JAIKUA; Jiraungkoorskul, Kanitta; Wannee JIRAUNGKOORSKUL

    2015-01-01

    This study evaluates the efficiency of a dietary supplement of Punica granatum in reducing the toxicity of ferric nitrilotriacetate in Oreochromis niloticus, with emphasis on histopathological analysis. Fish were given a dietary supplement in doses of 0 (groups 1 and 2) and 60 mg g-1 of P. granatum (groups 3 and 4) for 28 days. After a time, fish in groups 2 and 4 received intraperitoneal injections of 9 mg kg-1 of ferric nitrilotriacetate. 24 hours after injection, histopathological lesions ...

  10. Evaluation of Ferric and Ferrous Iron Therapies in Women with Iron Deficiency Anaemia

    OpenAIRE

    Ilhami Berber; Halit Diri; Mehmet Ali Erkurt; Ismet Aydogdu; Emin Kaya; Irfan Kuku

    2014-01-01

    Introduction. Different ferric and ferrous iron preparations can be used as oral iron supplements. Our aim was to compare the effects of oral ferric and ferrous iron therapies in women with iron deficiency anaemia. Methods. The present study included 104 women diagnosed with iron deficiency anaemia after evaluation. In the evaluations performed to detect the aetiology underlying the iron deficiency anaemia, it was found and treated. After the detection of the iron deficiency anaemia aetiolog...

  11. Ferric Sulfate Leaching of Pyrrhotite Tailings between 30 to 55 °C

    OpenAIRE

    Nazanin Samadifard; Cheryl E. Devine; Elizabeth Edwards; Krishna Mahadevan; Vladimiros G. Papangelakis

    2015-01-01

    Mine tailings present major environmental issues in the mining industry. However due to the depletion of high-grade sulfide ores for metal recovery, tailings could also be a potential resource for certain valuable metals. The present study investigates the potential to recover nickel from pyrrhotite tailings. Leaching tests were performed in acidic ferric sulfate media with 0.14 wt % solids to keep the ferric concentration essentially constant. The temperature was varied between 30 and 55 °C,...

  12. Bioaccumulation of cadmium bound to ferric hydroxide and particulate organic matter by the bivalve M. meretrix

    International Nuclear Information System (INIS)

    Ferric hydroxide and particulate organic matter are important pools of trace metals in sediments and control their accumulation by benthic animals. We investigated bioaccumulation of cadmium in bivalve Meretrix meretrix by using a simplified system of laboratory synthesized iron oxides and commercially obtained humic acids to represent the inorganic and organic matrix found in nature. The results showed that bioaccumulation characteristics were distinctly different for these two substrates. Bioaccumulation from ferric hydroxide was not observed at 70 and 140 mg/kg, while the clams started to absorb Cd at 140 mg/kg from organic matter and the bioaccumulation rate was faster than that from ferric hydroxide. Within 28 d, accumulation of Cd from organic matter appeared to reach a steady state after rising to a certain level, while absorption from ferric hydroxide appeared to follow a linear profile. The findings have implications about the assimilation of trace metals from sediments by benthic animals. - Highlights: ► Accumulation of Cd adsorbed on ferric hydroxide and particulate organics was studied. ► Bioaccumulation characteristics were distinctly different for the substrates. ► The result was attributed to different properties and bio-responses of the particles. ► Bivalves may not accumulate more metals associated with more bioavailable particles. - Bioaccumulation characteristics of adsorbed Cd on ferric hydroxide and particulate organic matter by bivalve M. meretrix are distinctly different.

  13. Bacterial Vaginosis

    Science.gov (United States)

    ... 586. Related Content STDs during Pregnancy Fact Sheet Pregnancy and HIV, Viral Hepatitis, and STD Prevention Pelvic Inflammatory Disease ( ... Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ... STDs See Also Pregnancy Reproductive ...

  14. Bacterial Meningitis

    Science.gov (United States)

    ... Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis Bacterial Meningitis Recommend on Facebook Tweet Share Compartir On this ... serious disease. Laboratory Methods for the Diagnosis of Meningitis This manual summarizes laboratory methods used to isolate, ...

  15. Prostatitis - bacterial

    Science.gov (United States)

    Any bacteria that can cause a urinary tract infection can cause acute bacterial prostatitis. Infections spread through sexual contact can cause prostatitis. These include chlamydia and gonorrhea . Sexually transmitted ...

  16. Bacterial Conjunctivitis

    OpenAIRE

    Köhle, Ülkü; Kükner, Şahap

    2003-01-01

    Conjunctivitis is an infection of the conjunctiva, generally characterized by irritation, itching, foreign body sensation, tearing and discharge. Bacterial conjunctivitis may be distinguished from other types of conjunctivitis by the presence of yellow–white mucopurulent discharge. It is the most common form of ocular infection all around the world. Staphylococcus species are the most common bacterial pathogenes, followed by Streptococcus pneumoniae and Haemophilus i...

  17. Dissolution behaviour of ferric pyrophosphate and its mixtures with soluble pyrophosphates: Potential strategy for increasing iron bioavailability.

    Science.gov (United States)

    Tian, Tian; Blanco, Elena; Smoukov, Stoyan K; Velev, Orlin D; Velikov, Krassimir P

    2016-10-01

    Ferric pyrophosphate (FePP) is a widely used iron source in food fortification and in nutritional supplements, due to its white colour, that is very uncommon for insoluble Fe salts. Although its dissolution is an important determinant of Fe adsorption in human body, the solubility characteristics of FePP are complex and not well understood. This report is a study on the solubility of FePP as a function of pH and excess of pyrophosphate ions. FePP powder is sparingly soluble in the pH range of 3-6 but slightly soluble at pH8. In the presence of pyrophosphate ions the solubility of FePP strongly increases at pH 5-8.5 due to formation a soluble complex between Fe(III) and pyrophosphate ions, which leads to an 8-10-fold increase in the total ionic iron concentration. This finding is beneficial for enhancing iron bioavailability, which important for the design of fortified food, beverages, and nutraceutical products. PMID:27132828

  18. Current Progress of Capacitive Deionization for Removal of Pollutant Ions

    Science.gov (United States)

    Gaikwad, Mahendra S.; Balomajumder, Chandrajit

    2016-08-01

    A mini review of a recently developing water purification technology capacitive deionization (CDI) applied for removal of pollutant ions is provided. The current progress of CDI for removal of different pollutant ions such as arsenic, fluoride, boron, phosphate, lithium, copper, cadmium, ferric, and nitrate ions is presented. This paper aims at motivating new research opportunities in capacitive deionization technology for removal of pollutant ions from polluted water.

  19. Pial iontophoresis of ferric chloride versus cortical ferric chloride injection in establishing iron-induced posttraumatic epilepsy animal models

    Institute of Scientific and Technical Information of China (English)

    Jinlan Jin; Hanping Zhuang; Shaoming Liu; Junqiang Si; Ying Chen; Jiamei Yao

    2006-01-01

    BACKGROUND: In order to study the pathogenesis of iron-induced posttraumatic epilepsy (PTE), foreign scholars have established several kinds of PTE animal models, among which, the iron- induced PTE animal models proposed by Willmore is the most famous. The iron-induced PTE animal models can be established by two methods: one is cortical ferric chloride injection (CFCI) and the other one is pial iontophoresis of ferric chloride (PIFC). Because Willmore did not give out the elaboration of the behaviors and electroencephalograms (EEGs) of the iron induced PTE animal models established by these two methods, so we have known little about these animal models.OBJECTIVE: To observe the behaviors and EEGs of the iron-induced PTE animal models established by PIFC and CFCI, in order to compare the differences and the study value of these two methods.DESIGN: Qualitative controlled observation trial.SETTING: Department of Neurosurgery, Urumqi General Hospital, Lanzhou Military Area Command of Chinese PLA.MATERIALS: Forty healthy adult male SD rats, weighing 200 to 250 g, were involved in this experiment.pany, USA), the wireless blue tooth electroencephlograms recording system (Nuocheng electric Co. Ltd,Shanghai), a set of air turbine dental drill unit, dental base acrylic resin powder, microinjector (50 μL), amperemeter (1 mA), a pair of batteries, electric resistance (200 kΩ) , variable resistance (100 kΩ), tubule with endo-meridians of 2 mm (used as import tube), several silver wire segments and several acupuncture needles were employed in this study.METHODS: This study was carried out in the Experimental Animal Center of the Urumqi General Hospital,Lanzhou Military Area Command of Chinese PLA between November 2004 and April 2005. Establishing the PET animal models by CFCI method: Twenty SD rats were taken, intraperitoneally anesthetized with 50 mg/kg barbanylum and fixed on stereotaxic apparatus. A cranial burr hole with the diameter of 2 mm was drilled 3mm behind the

  20. Cost-minimization analysis favours intravenous ferric carboxymaltose over ferric sucrose for the ambulatory treatment of severe iron deficiency.

    Directory of Open Access Journals (Sweden)

    Xavier Calvet

    Full Text Available OBJECTIVE: Intravenous iron is widely used to treat iron deficiency in day-care units. Ferric carboxymaltose (FCM allows administration of larger iron doses than iron sucrose (IS in each infusion (1000 mg vs. 200 mg. As FCM reduces the number of infusions required but is more expensive, we performed a cost-minimization analysis to compare the cost impact of the two drugs. MATERIALS AND METHODS: The number of infusions and the iron dose of 111 consecutive patients who received intravenous iron at a gastrointestinal diseases day-care unit from 8/2007 to 7/2008 were retrospectively obtained. Costs of intravenous iron drugs were obtained from the Spanish regulatory agencies. The accounting department of the Hospital determined hospital direct and indirect costs for outpatient iron infusion. Non-hospital direct costs were calculated on the basis of patient interviews. In the pharmacoeconomic model, base case mean costs per patient were calculated for administering 1000 mg of iron per infusion using FCM or 200 mg using IS. Sensitivity analysis and Monte Carlo simulation were performed. RESULTS: Under baseline assumptions, the estimated cost of iron infusion per patient and year was €304 for IS and €274 for FCM, a difference of €30 in favour of FCM. Adding non-hospital direct costs to the model increased the difference to €67 (€354 for IS vs. €287 for FCM. A Monte Carlo simulation taking into account non-hospital direct costs favoured the use of FCM in 97% of simulations. CONCLUSION: In this pharmacoeconomic analysis, FCM infusion reduced the costs of iron infusion at a gastrointestinal day-care unit.

  1. Probing the Role of Divalent Metal Ions in a Bacterial Psychrophilic Metalloprotease: Binding Studies of an Enzyme in the Crystalline State by X-Ray Crystallography

    OpenAIRE

    Ravaud, Stephanie; Gouet, Patrice; Haser, Richard; Aghajari, Nushin

    2003-01-01

    The psychrophilic alkaline metalloprotease (PAP) produced by a Pseudomonas bacterium isolated in Antarctica belongs to the clan of metzincins, for which a zinc ion is essential for catalytic activity. Binding studies in the crystalline state have been performed by X-ray crystallography in order to improve the understanding of the role of the zinc and calcium ions bound to this protease. Cocrystallization and soaking experiments with EDTA in a concentration range from 1 to 85 mM have resulted ...

  2. EFFECT OF BROKEN IMPERVIOUS IRON LAYER ON WATER AVAILABILITY TO SEMI-ARID NORTHERN GHANAIAN FERRIC LIXISOLS

    Directory of Open Access Journals (Sweden)

    Akwasi Asamoah

    2013-03-01

    Full Text Available Rainwater is not readily available to sandy loam Ghanaian ferric lixisols. In an attempt to increase water availability to Nyankpala ferric lixisols, their impervious iron pan was broken. Average yield (number of bags of maize from ferric lexisol with ironpan broken was compared with that with iron pan unbroken. At an average annual rainfall of 64.125 to 106.775 mm for Nyampkala, ferric lexisol with or without iron pan broken yielded similar quantity (20-25bgs/ha of maize. Breaking of ironpan alone cannot increase water availability to Nyankpala ferric lixisols. Measures other than the breaking of iron pan are needed to increase water availability to ferreiclesisols and similar soils. Research into sustainable technologies such as permanent amendments for increased soil water availability to ferric lixisol and similar soils is required.

  3. Effect of natural dissolved organic carbon on phosphate removal by ferric chloride and aluminum sulfate treatment of wetland waters

    Science.gov (United States)

    Qualls, Robert G.; Sherwood, Lindsay J.; Richardson, Curtis J.

    2009-09-01

    The use of wetlands for the removal of excess N and P has become widespread. Some sensitive P-limited ecosystems, however, may require additional reductions in the concentration of P entering the system. It has been proposed that the treatment of wetlands through addition of ferric chloride or aluminum sulfate can augment the natural P removal mechanisms. However, high concentrations of natural dissolved organic matter may interfere with the removal of P by metal addition. We evaluated the doses of ferric chloride and aluminum sulfate necessary to reduce total P concentrations below 0.32 μM (10 μg/L) in water from the Northern Everglades, and we determined the effect of various concentrations (21, 38, and 60 mg/L) of natural dissolved organic carbon (DOC) on the removal of PO4 and total P. High concentrations of natural DOC inhibited both the short-term removal of PO4 and the longer-term removal of total P from the water column. Similar results were observed using 15 μM citric acid in an experiment to determine whether citric acid could effectively mimic the inhibition of phosphorus removal associated with natural DOC. Stoichiometry of these experiments indicates that the mechanism of natural DOC interference was not complexation of the metal ions by the DOC; we hypothesize that it could be adsorption to the terminal hydroxyl groups on a polynuclear Fe or Al colloid, effectively blocking the adsorption sites from a phosphate molecule. Also, the ability of citric acid to mimic the inhibitory effects also suggests that the results of the study are broadly applicable to wetland and other waters with high natural organic acid concentrations.

  4. Prediction of ferric iron precipitation in bioleaching process using partial least squares and artificial neural network

    Directory of Open Access Journals (Sweden)

    Golmohammadi Hassan

    2013-01-01

    Full Text Available A quantitative structure-property relationship (QSPR study based on partial least squares (PLS and artificial neural network (ANN was developed for the prediction of ferric iron precipitation in bioleaching process. The leaching temperature, initial pH, oxidation/reduction potential (ORP, ferrous concentration and particle size of ore were used as inputs to the network. The output of the model was ferric iron precipitation. The optimal condition of the neural network was obtained by adjusting various parameters by trial-and-error. After optimization and training of the network according to back-propagation algorithm, a 5-5-1 neural network was generated for prediction of ferric iron precipitation. The root mean square error for the neural network calculated ferric iron precipitation for training, prediction and validation set are 32.860, 40.739 and 35.890, respectively, which are smaller than those obtained by PLS model (180.972, 165.047 and 149.950, respectively. Results obtained reveal the reliability and good predictivity of neural network model for the prediction of ferric iron precipitation in bioleaching process.

  5. Evaluation of Ferric and Ferrous Iron Therapies in Women with Iron Deficiency Anaemia

    Directory of Open Access Journals (Sweden)

    Ilhami Berber

    2014-01-01

    Full Text Available Introduction. Different ferric and ferrous iron preparations can be used as oral iron supplements. Our aim was to compare the effects of oral ferric and ferrous iron therapies in women with iron deficiency anaemia. Methods. The present study included 104 women diagnosed with iron deficiency anaemia after evaluation. In the evaluations performed to detect the aetiology underlying the iron deficiency anaemia, it was found and treated. After the detection of the iron deficiency anaemia aetiology and treatment of the underlying aetiology, the ferric group consisted of 30 patients treated with oral ferric protein succinylate tablets (2 × 40 mg elemental iron/day, and the second group consisted of 34 patients treated with oral ferrous glycine sulphate tablets (2 × 40 mg elemental iron/day for three months. In all patients, the following laboratory evaluations were performed before beginning treatment and after treatment. Results. The mean haemoglobin and haematocrit increases were 0.95 g/dL and 2.62% in the ferric group, while they were 2.25 g/dL and 5.91% in the ferrous group, respectively. A significant difference was found between the groups regarding the increase in haemoglobin and haematocrit values (P<0.05. Conclusion. Data are submitted on the good tolerability, higher efficacy, and lower cost of the ferrous preparation used in our study.

  6. Evaluation of ferric and ferrous iron therapies in women with iron deficiency anaemia.

    Science.gov (United States)

    Berber, Ilhami; Diri, Halit; Erkurt, Mehmet Ali; Aydogdu, Ismet; Kaya, Emin; Kuku, Irfan

    2014-01-01

    Introduction. Different ferric and ferrous iron preparations can be used as oral iron supplements. Our aim was to compare the effects of oral ferric and ferrous iron therapies in women with iron deficiency anaemia. Methods. The present study included 104 women diagnosed with iron deficiency anaemia after evaluation. In the evaluations performed to detect the aetiology underlying the iron deficiency anaemia, it was found and treated. After the detection of the iron deficiency anaemia aetiology and treatment of the underlying aetiology, the ferric group consisted of 30 patients treated with oral ferric protein succinylate tablets (2 × 40 mg elemental iron/day), and the second group consisted of 34 patients treated with oral ferrous glycine sulphate tablets (2 × 40 mg elemental iron/day) for three months. In all patients, the following laboratory evaluations were performed before beginning treatment and after treatment. Results. The mean haemoglobin and haematocrit increases were 0.95 g/dL and 2.62% in the ferric group, while they were 2.25 g/dL and 5.91% in the ferrous group, respectively. A significant difference was found between the groups regarding the increase in haemoglobin and haematocrit values (P ferrous preparation used in our study. PMID:25006339

  7. Synthesis and characterization of γ-ferric oxide nanoparticles and their effect on Solanum lycopersicum.

    Science.gov (United States)

    Pavani, Tambur; Rao, K Venkateswara; Chakra, Ch Shilpa; Prabhu, Y T

    2016-05-01

    γ-Ferric oxide nanoparticles are synthesized through modern and facile ayurvedic route followed by normal and special purification steps, which are both cost-effective and eco-friendly. These synthesized γ-ferric oxide nanoparticles were applied on Solanum lycopersicum to search the effect on chlorophyll content. This process involves multiple filtration and calcination steps. The synthesized samples were analyzed by X-ray diffraction (XRD), UV-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and particle size analysis (PSA) to identify the purification step's influence on the structural, optical, morphological, magnetic, and particle size properties of ferric oxide nanoparticles (γ-phase). X-ray diffraction has revealed that ferric oxide nanoparticles have rhombohedral structure of α-phase (hematite) in initial purification process later transformed into cubic structure γ-phase (maghemite). UV-vis spectroscopy analysis has clearly shown that by repetitive purification steps, λmax has increased from 230 to 340 nm. TEM result has an intercorrelation with XRD results. γ-Ferric oxide nanoparticles were tested on Solanum lycopersicum (tomato seeds). The changes in the contents of chlorophyll a, chlorophyll b, and total carotene were studied using spectral measurements at two different dosages-0.5 and 2 M. As a result, at 0.5-M concentration, magnetic nanoparticles exhibit fruitful results by increasing the crop yield and being more resistant to chlorosis. PMID:26296507

  8. Proteomics of foodborne bacterial pathogens

    Science.gov (United States)

    This chapter focuses on recent research on foodborne bacterial pathogens that use mass spectrometry-based proteomic techniques as well as protein microarrays. Mass spectrometry ionization techniques (e.g. electrospray ionization and matrix-assisted laser desorption/ionization), analyzers (e.g. ion ...

  9. Uranium potentiometer determination in inactive atmosphere with ferric sulfate

    International Nuclear Information System (INIS)

    Potenciometric titration of Uranium with (SO4)3 Fe2, using Cd as reducing agent has been studied; acidity and sensibility of this reaction are fixed. This method yields good results for uranite group, removing previously phosphate by ion exchange with Amberlite IR-120. (Author)

  10. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    parameters, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion is...... the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental...

  11. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, mea

  12. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  13. Juvenile ferric iron prevents microbiota dysbiosis and colitis in adult rodents

    Institute of Scientific and Technical Information of China (English)

    Chourouk Ettreiki; Pascale Gadonna-Widehem; Irène Mangin; Mo(i)se Co(e)ffier; Carine Delayre-Orthez; Pauline M Anton

    2012-01-01

    AIM:To assess whether juvenile chronic ferric iron ingestion limit colitis and dysbiosis at adulthood in rats and mice.METHODS:Two sets of experiments were designed.In the first set,recently weaned mice were either orally administered ferrous (Fe2+) iron salt or ferric (Fe3+) microencapsulated iron for 6 wk.The last week of experiments trinitrobenzene sulfonic acid (TNBS) colitis was induced.In the second set,juvenile rats received the microencapsulated ferric iron for 6 wk and were also submitted to TNBS colitis during the last week of experiments.In both sets of experiments,animals were sacrificed 7 d after TNBS instillation.Severity of the inflammation was assessed by scoring macroscopic lesions and quantifying colonic myeloperoxidase (MPO) activity.Alteration of the microflora profile was estimated using quantitative polymerase chain reaction (qPCR) by measuring the evolution of total caecal microflora,Bacteroidetes,Firmicutes and enterobacteria.RESULTS:Neither ferrous nor ferric iron daily exposures at the juvenile period result in any effect in control animals at adulthood although ferrous iron repeated administration in infancy limited weight gain.Ferrous iron was unable to limit the experimental colitis (1.71 ± 0.27MPO U/mg protein vs 2.47 ± 0.22 MPO U/mg protein in colitic mice).In contrast,ferric iron significantly prevented the increase of MPO activity (1.64 ± 0.14 MPO U/mg protein) in TNBS-induced colitis.Moreover,this positive effect was observed at both the doses of ferric iron used (75 and 150 mg/kg per day po-6 wk).In the study we also compared,in both rats and mice,the consequences of chronic repeated low level exposure to ferric iron (75 mg/kg per day po-6 wk) on TNBS-induced colitis and its related dysbiosis.We confirmed that ferric iron limited the TNBS-induced increase of MPO activity in both the rodent species.Furthermore,we assessed the ferric iron incidence on TNBS-induced intestinal microbiota dysbiosis.At first,we needed to optimize the

  14. Direct inhibition by nitric oxide of the transcriptional ferric uptake regulation protein via nitrosylation of the iron

    Science.gov (United States)

    D'Autréaux, Benoît; Touati, Danièle; Bersch, Beate; Latour, Jean-Marc; Michaud-Soret, Isabelle

    2002-01-01

    Ferric uptake regulation protein (Fur) is a bacterial global regulator that uses iron as a cofactor to bind to specific DNA sequences. The function of Fur is not limited to iron homeostasis. A wide variety of genes involved in various mechanisms such as oxidative and acid stresses are under Fur control. Flavohemoglobin (Hmp) is an NO-detoxifying enzyme induced by NO and nitrosothiol compounds. Fur recently was found to regulate hmp in Salmonella typhimurium, and in Escherichia coli, the iron-chelating agent 2,2′-dipyridyl induces hmp expression. We now establish direct inhibition of E. coli Fur activity by NO. By using chromosomal Fur-regulated lacZ reporter fusion in E. coli, Fur activity is switched off by NO at micromolar concentration. In vitro Fur DNA-binding activity, as measured by protection of restriction site in aerobactin promoter, is directly sensitive to NO. NO reacts with FeII in purified FeFur protein to form a S = 1/2 low-spin FeFur–NO complex with a g = 2.03 EPR signal. Appearance of the same EPR signal in NO-treated cells links nitrosylation of the iron with Fur inhibition. The nitrosylated Fur protein is still a dimer and is stable in anaerobiosis but slowly decays in air. This inhibition probably arises from a conformational switch, leading to an inactive dimeric protein. These data establish a link between control of iron metabolism and the response to NO effects. PMID:12475930

  15. Glyphosate inhibition of ferric reductase activity in iron deficient sunflower roots

    OpenAIRE

    Öztürk, Levent; Ozturk, Levent; Yazıcı, Mustafa Atilla; Yazici, Mustafa Atilla; Eker, Selim; Gökmen, Özay Özgür; Gokmen, Ozay Ozgur; Römheld, Volker; Romheld, Volker; ÇAKMAK, İsmail; Cakmak, Ismail

    2007-01-01

    Iron (Fe) deficiency is increasingly being observed in cropping systems with frequent glyphosate applications. A likely reason for this is that glyphosate interferes with root uptake of Fe by inhibiting ferric reductase in roots required for Fe acquisition by dicot and nongrass species. This study investigated the role of drift rates of glyphosate (0.32, 0.95 or 1.89 mM glyphosate corresponding to 1, 3 and 6% of the recommended herbicidal dose, respectively) on ferric reductase activity of...

  16. Microbial reduction of ferric iron oxyhydroxides as a way for remediation of grey forest soils heavily polluted with toxic metals by infiltration of acid mine drainage

    Science.gov (United States)

    Georgiev, Plamen; Groudev, Stoyan; Spasova, Irena; Nicolova, Marina

    2015-04-01

    The abandoned uranium mine Curilo is a permanent source of acid mine drainage (AMD) which steadily contaminated grey forest soils in the area. As a result, the soil pH was highly acidic and the concentration of copper, lead, arsenic, and uranium in the topsoil was higher than the relevant Maximum Admissible Concentration (MAC) for soils. The leaching test revealed that approximately half of each pollutant was presented as a reducible fraction as well as the ferric iron in horizon A was presented mainly as minerals with amorphous structure. So, the approach for remediation of the AMD-affected soils was based on the process of redoxolysis carried out by iron-reducing bacteria. Ferric iron hydroxides reduction and the heavy metals released into soil solutions was studied in the dependence on the source of organic (fresh or silage hay) which was used for growth and activity of soil microflora, initial soil pH (3.65; 4.2; and 5.1), and the ion content of irrigation solutions. The combination of limestone (2.0 g/ kg soil), silage addition (at rate of 45 g dry weight/ kg soil) in the beginning and reiterated at 6 month since the start of soil remediation, and periodical soil irrigation with slightly acidic solutions containing CaCl2 was sufficient the content of lead and arsenic in horizon A to be decreased to concentrations similar to the relevant MAC. The reducible, exchangeable, and carbonate mobile fractions were phases from which the pollutants was leached during the applied soil remediation. It determined the higher reduction of the pollutants bioavailability also as well as the process of ferric iron reduction was combined with neutralization of the soil acidity to pH (H2O) 6.2.

  17. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. PMID:27474242

  18. A study on leaching behaviour of cement blocks used as matrix for fixation of Cs activity along with ferric

    Indian Academy of Sciences (India)

    Pushpa Muthiah; K S Seshadri; P K Sinha; K B Lal

    2007-10-01

    Study on the cementation of the regenerated activity (from spent resin using ferric as regenerant) containing ferric in cement matrix showed that compressive strength and leaching behaviour are better when the ferric strength was < 5 N. The diffusion coefficient of Cs from the cement matrix was found to be in the range 2.4 × 10-5 cm2/day and 5.9 × 10-5 cm2/day with ferric solutions of strength in the range 0.5–3 N. When bentonite and vermiculite were included in the cement matrix, the diffusion coefficient of Cs was found to be in the range 6.2 × 10-7 cm2/day to 1.26 × 10-5 cm2/day with ferric strength in the same range.

  19. Ferric saccharate induces oxygen radical stress and endothelial dysfunction in vivo

    NARCIS (Netherlands)

    Rooyakkers, TM; Stroes, ESG; Kooistra, MP; van Faassen, EE; Hider, RC; Rabelink, TJ; Marx, JJM

    2002-01-01

    Background Intravenous iron supplementation is used widely in haemodialysis patients. However, nontransferrin-bound iron (NTBI), which increases after intravenous supplementation of ferric saccharate, has been suggested to act as a catalytic agent in oxygen radical formation in vitro and may thus co

  20. Effect of glutaraldehyde and ferric sulfate on shear bond strength of adhesives to primary dentin

    Directory of Open Access Journals (Sweden)

    Prabhakar A

    2008-12-01

    Full Text Available Aim: The present study was undertaken to evaluate the effect of alternative pulpotomy agents such as glutaraldehyde and ferric sulfate on the shear bond strength of self-etch adhesive systems to dentin of primary teeth. Materials and Methods: Eighty human primary molar teeth were sectioned in a mesiodistal direction and divided into experimental and control groups. Lingual dentin specimens in experimental groups were treated with glutaraldehyde and ferric sulfate. Buccal surfaces soaked in water served as control group. Each group was then divided into two groups based on the adhesive system used: Clearfil SE Bond and Adper Prompt L-Pop. A teflon mold was used to build the composite (Filtek Z-250 cylinders on the dentinal surface of all the specimens. Shear bond strength was tested for all the specimens with an Instron Universal Testing Machine. The failure mode analysis was performed with a Scanning Electron Microscope (SEM. Results: The results revealed that glutaraldehyde and ferric sulfate significantly reduced the shear bond strength of the tested adhesive systems to primary dentin. Clearfil SE Bond showed much higher shear bond strength than Adper Prompt L Pop to primary dentin. SEM analysis revealed a predominant cohesive failure mode for both adhesive systems. Conclusion: This study revealed that the pulpotomy medicaments glutaraldehyde and ferric sulfate adversely affected the bonding of self-etch adhesive systems to primary dentin.

  1. THE SURFACE PHOTOCHEMISTRY OF PROCYMIDONE IN PRESENCE OF AMMONIUM FERRIC CITRATE

    Directory of Open Access Journals (Sweden)

    Ivan Osipov

    2015-12-01

    Full Text Available Procymidone was chosen as the model compound and its phototransformation was followed under sunlight irradiation. The main photodegradation products on silica is 3,5-dichloroaniline and 3,5-diclorphenilisocyanate. The use of ammonium ferric citrate enhances the degradation of the procymidone.

  2. Ferric carboxymaltose prevents recurrence of anemia in patients with inflammatory bowel disease

    DEFF Research Database (Denmark)

    Evstatiev, Rayko; Alexeeva, Olga; Bokemeyer, Bernd;

    2013-01-01

    Iron-deficiency anemia is the most common systemic complication of inflammatory bowel diseases (IBD). Iron-deficiency anemia recurs frequently and rapidly after iron-replacement therapy in patients with IBD. We performed a randomized, placebo-controlled trial to determine if administration...... of ferric carboxymaltose (FCM) prevents anemia in patients with IBD and low levels of serum ferritin....

  3. Photoexcitation dynamics of nitric oxide bound ferric myoglobin probed by femtosecond IR spectroscopy

    Directory of Open Access Journals (Sweden)

    Park Jaehun

    2013-03-01

    Full Text Available Time-resolved vibrational spectra show that photolysis quantum yield of NO bound ferric myoglobin is smaller than 0.86, the deligated NO geminately rebinds with subnanosecond time scale, and the rebinding kinetics depends on protein conformation.

  4. A Ferric-Peroxo Intermediate in the Oxidation of Heme by IsdI.

    Science.gov (United States)

    Takayama, Shin-Ichi J; Loutet, Slade A; Mauk, A Grant; Murphy, Michael E P

    2015-04-28

    The canonical heme oxygenases (HOs) catalyze heme oxidation via a heme-bound hydroperoxo intermediate that is stabilized by a water cluster at the active site of the enzyme. In contrast, the hydrophobic active site of IsdI, a heme-degrading enzyme from Staphylococcus aureus, lacks a water cluster and is expected to oxidize heme by an alternative mechanism. Reaction of the IsdI-heme complex with either H2O2 or m-chloroperoxybenzoic acid fails to produce a specific oxidized heme iron intermediate, suggesting that ferric-hydroperoxo or ferryl derivatives of IsdI are not involved in the catalytic mechanism of this enzyme. IsdI lacks a proton-donating group in the distal heme pocket, so the possible involvement of a ferric-peroxo intermediate has been evaluated. Density functional theory (DFT) calculations indicate that heme oxidation involving a ferric-peroxo intermediate is energetically accessible, whereas the energy barrier for a reaction involving a ferric-hydroperoxo intermediate is too great in the absence of a proton donor. We propose that IsdI catalyzes heme oxidation through nucleophilic attack by the heme-bound peroxo species. This proposal is consistent with our previous demonstration by nuclear magnetic resonance spectroscopy that heme ruffling increases the susceptibility of the meso-carbon of heme to nucleophilic attack. PMID:25853501

  5. Clinical application of ferric-pyrophosphate soluble as a contrast agent for MRI of obstructive jaundice

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, Hajime; Matoba, Munetaka; Takarada, Akira; Tonami, Hisao; Okimura, Teturou; Yamamoto, Itaru; Yamaguchi, Kenzo (Kanazawa Medical Univ., Ishikawa (Japan))

    1992-10-01

    Indication of magnetic resonance imaging (MRI) for the biliary tract system is of limited value in view of motion artifacts and others. In an effort to visualize lesions causing obstructive jaundice, approximately 20 ml of ferric-pyrophosphate (0.5[approx]30 mmol/L) was used as contrast medium in MRI examination. The subjects were 16 patients, who underwent transhepatic cholangeal drainage (PTCD) for obstructive jaundice attributable to pancreas head (n=6), cancer of the biliary tract (n=6), metastatic lymphadenopathy (n=3), and choledocholithiasis (n=one). Signal intensity associated with various diluted solutions of ferric-pyrophosphate was determined on T[sub 1]-weighted images. The clearest and highest intensity images were obtained on T[sub 1]-weighted images enhanced with 1.0 mmol/L of ferric-pyrophosphate soluble. Injection of ferric pyrophosphate into the iliary tract through PTCD-tube allowed clear visualization of the intraheptic bile duct on MRI. The dilatated biliary tract was clearly detected in all 16 patients. Stone responsible for causing obstruction was also shown as a signal void area in the common bile duct at the end of dilatation. For cancer of the pancreatic head, tumor invasion to both the common bile duct and the end of the stenotic site was visualized simultaneously. For cancer of the common duct, tumor was visualized as low signal intensity at the end of the common bile duct. None of the side effects were encountered. MRI with ferric-pyrophosphate was considered more helpful in the detection of not only obstructive lesions in the biliary tract but also tumor invasion into the surrounding tissue. (N.K.).

  6. Measurement of the ferric diffusion coefficient in agarose and gelatine gels by utilization of the evolution of a radiation induced edge as reflected in relaxation rate images

    International Nuclear Information System (INIS)

    A method has been developed to determine the diffusion coefficients of ferric ions in ferrous sulphate doped gels. A radiation induced edge was created in the gel, and two spin-echo sequences were used to acquire a pair of images of the gel at different points of time. For each of these image pairs, a longitudinal relaxation rate image was derived. From profiles through these images, the standard deviations of the Gaussian functions that characterize diffusion were determined. These data provided the basis for the determination of the ferric diffusion coefficients by two different methods. Simulations indicate that the use of single spin-echo images in this procedure may in some cases lead to a significant underestimation of the diffusion coefficient. The technique was applied to different agarose and gelatine gels that were prepared, irradiated and imaged simultaneously. The results indicate that the diffusion coefficient is lower in a gelatine gel than in an agarose gel. Addition of xylenol orange to a gelatine gel lowers the diffusion coefficient from 1.45 to 0.81 mm2 h-1, at the cost of significantly lower R1 sensitivity. The addition of benzoic acid to the latter gel did not increase the R1 sensitivity. (author) OK

  7. Observation on Ferric Pyrophosphate and New Inquiry on Mechanisms of Capacity Degradation in Lithium Iron Phosphate Cathode Materials

    International Nuclear Information System (INIS)

    The hierarchical carbon-coated lithium iron phosphate (LiFePO4) nano-grain microspheres are prepared by chemical co-precipitation method. The microstructure and cycling performance are compared for samples treated at 975 K and 1025 K. Transmission electron micrograph (TEM) analysis confirms the existence of ferric pyrophosphate phase of the general formula Fe4(P2O7)3. Reasons for the formation of the crystalline Fe4(P2O7)3 phase are intensively discussed. It is considered that a little amount of Fe4(P2O7)3 phase has no distinct detrimental effect on the cycling capacity of samples. Although there is a big decrease from 132 to 74.5 mAh/g in discharge capacity at a current rate of 1C for the sample treated at 975 K from 400 to 500 cycles. The capacities for the sample were observed to be recovered to its theoretical value in discharge at a current rate of 0.1C after 500 cycles. It is demonstrated that the degradation behavior for the sample treated at 975 K is attributed to the increase of diffusion resistance of the lithium ions into the bulk of LiFePO4 electrode materials, which is not reported before in the literatures

  8. Binding of heavy metal ions in aggregates of microbial cells, EPS and biogenic iron minerals measured in-situ using metal- and glycoconjugates-specific fluorophores

    Science.gov (United States)

    Hao, Likai; Guo, Yuan; Byrne, James M.; Zeitvogel, Fabian; Schmid, Gregor; Ingino, Pablo; Li, Jianli; Neu, Thomas R.; Swanner, Elizabeth D.; Kappler, Andreas; Obst, Martin

    2016-05-01

    Aggregates consisting of bacterial cells, extracellular polymeric substances (EPS) and Fe(III) minerals formed by Fe(II)-oxidizing bacteria are common at bulk or microscale chemical interfaces where Fe cycling occurs. The high sorption capacity and binding capacity of cells, EPS, and minerals controls the mobility and fate of heavy metals. However, it remains unclear to which of these component(s) the metals will bind in complex aggregates. To clarify this question, the present study focuses on 3D mapping of heavy metals sorbed to cells, glycoconjugates that comprise the majority of EPS constituents, and Fe(III) mineral aggregates formed by the phototrophic Fe(II)-oxidizing bacteria Rhodobacter ferrooxidans SW2 using confocal laser scanning microscopy (CLSM) in combination with metal- and glycoconjugates-specific fluorophores. The present study evaluated the influence of glycoconjugates, microbial cell surfaces, and (biogenic) Fe(III) minerals, and the availability of ferrous and ferric iron on heavy metal sorption. Analyses in this study provide detailed knowledge on the spatial distribution of metal ions in the aggregates at the sub-μm scale, which is essential to understand the underlying mechanisms of microbe-mineral-metal interactions. The heavy metals (Au3+, Cd2+, Cr3+, CrO42-, Cu2+, Hg2+, Ni2+, Pd2+, tributyltin (TBT) and Zn2+) were found mainly sorbed to cell surfaces, present within the glycoconjugates matrix, and bound to the mineral surfaces, but not incorporated into the biogenic Fe(III) minerals. Statistical analysis revealed that all ten heavy metals tested showed relatively similar sorption behavior that was affected by the presence of sorbed ferrous and ferric iron. Results in this study showed that in addition to the mineral surfaces, both bacterial cell surfaces and the glycoconjugates provided most of sorption sites for heavy metals. Simultaneously, ferrous and ferric iron ions competed with the heavy metals for sorption sites on the organic

  9. Cloning, sequencing, and transcriptional regulation of viuA, the gene encoding the ferric vibriobactin receptor of Vibrio cholerae.

    OpenAIRE

    Butterton, J R; Stoebner, J A; Payne, S M; Calderwood, S B

    1992-01-01

    A 74-kDa iron-regulated outer membrane protein of Vibrio cholerae acts as the receptor for the V. cholerae iron-siderophore complex, ferric vibriobactin. MBG14, a mutant of V. cholerae 0395 containing a TnphoA insertion in a gene designated viuA, lacks this 74-kDa outer membrane protein and is unable to bind or utilize exogenous ferric vibriobactin. Introduction of a plasmid containing the complete viuA coding sequence and 513 bp of upstream DNA into MBG14 restored ferric vibriobactin utiliza...

  10. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  11. Oxidation of calprotectin by hypochlorous acid prevents chelation of essential metal ions and allows bacterial growth: Relevance to infections in cystic fibrosis.

    Science.gov (United States)

    Magon, Nicholas J; Turner, Rufus; Gearry, Richard B; Hampton, Mark B; Sly, Peter D; Kettle, Anthony J

    2015-09-01

    Calprotectin provides nutritional immunity by sequestering manganese and zinc ions. It is abundant in the lungs of patients with cystic fibrosis but fails to prevent their recurrent infections. Calprotectin is a major protein of neutrophils and composed of two monomers, S100A8 and S100A9. We show that the ability of calprotectin to limit growth of Staphylococcus aureus and Pseudomonas aeruginosa is exquisitely sensitive to oxidation by hypochlorous acid. The N-terminal cysteine residue on S100A9 was highly susceptible to oxidation which resulted in cross-linking of the protein monomers. The N-terminal methionine of S100A8 was also readily oxidized by hypochlorous acid, forming both the methionine sulfoxide and the unique product dehydromethionine. Isolated human neutrophils formed these modifications on calprotectin when their myeloperoxidase generated hypochlorous acid. Up to 90% of the N-terminal amine on S100A8 in bronchoalveolar lavage fluid from young children with cystic fibrosis was oxidized. Oxidized calprotectin was higher in children with cystic fibrosis compared to disease controls, and further elevated in those patients with infections. Our data suggest that oxidative stress associated with inflammation in cystic fibrosis will stop metal sequestration by calprotectin. Consequently, strategies aimed at blocking extracellular myeloperoxidase activity should enable calprotectin to provide nutritional immunity within the airways. PMID:26006104

  12. Templated in-situ synthesis of gold nanoclusters conjugated to drug target bacterial enoyl-ACP reductase, and their application to the detection of mercury ions using a test stripe

    International Nuclear Information System (INIS)

    Fluorescent gold nanoclusters (AuNCs) were synthesized using a drug target bacterial enoyl-ACP reductase (FabI) as a template. The physical and chemical properties of the AuNCs were studied by UV-vis absorption, fluorescence, X-ray photoelectron spectroscopy and TEM. The AuNCs-FabI conjugate was prepared by in situ reduction of tetrachloroaurate in the presence of FabI. The conjugated particles were loaded onto nylon membranes by taking advantage of the electrostatic interaction between the negatively charged AuNCs-FabI and the nylon film which is positively charged at pH 7.4. This results in the formation of a test stripe with sensor spots that can be used to detect Hg(II) ion in the 1 nM to 10 μM concentration range. The test stripes are simple, convenient, selective, sensitive, and can be quickly read out with bare eyes after illumination with a UV lamp. (author)

  13. Protein-mediated adhesion of the dissimilatory Fe(III)-reducing bacterium Shewanella alga BrY to hydrous ferric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Caccavo, F. Jr.

    1999-11-01

    The rate and extent of bacterial Fe(III) mineral reduction are governed by molecular-scale interactions between the bacterial cell surface and the mineral surface. These interactions are poorly understood. This study examined the role of surface proteins in the adhesion of Shewanella alga BrY to hydrous ferric oxide (HFO). Enzymatic degradation of cell surface polysaccharides had no effect on cell adhesion to HFO. The proteolytic enzymes Streptomyces griseus protease and chymotrypsin inhibited the adhesion of S. alga BrY cells to HFO through catalytic degradation of surface proteins. Trypsin inhibited S. alga BrY adhesion solely through surface-coating effects. Protease and chymotrypsin also mediated desorption of adhered S. alga BrY cells from HFO while trypsin did not mediate cell desorption. Protease removed a single peptide band that represented a protein with an apparent molecular mass of 50 kDa. Chymotrypsin removed two peptide bands that represented proteins with apparent molecular masses of 60 and 31 kDa. These proteins represent putative HGO adhesion molecules. A. alga BrY adhesion was inhibited by up to 46% when cells were cultured at sub-MICs of chloramphenicol, suggesting that protein synthesis is necessary for adhesion. Proteins extracted from the surface of S. alga BrY cells inhibited adhesion to HFO by up to 41%. A number of these proteins bound specifically to HFO, suggesting that a complex system of surface proteins mediates S. alga BrY adhesion to HFO.

  14. Conclusion on the peer review of the pesticide risk assessment of the active substance ferric phosphate

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2015-01-01

    Full Text Available The conclusions of the European Food Safety Authority (EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State Germany, for the pesticide active substance ferric phosphate are reported. The context of the peer review was that required by Commission Regulation (EU No 1141/2010 as amended by Commission Implementing Regulation (EU No 380/2013. The conclusions were reached on the basis of the evaluation of the representative use of ferric phosphate as a molluscicide in agriculture and horticulture for control of harmful slug and snail species in all edible and non-edible crops. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and literature in the dossier peer reviewed, are presented. Missing information identified as being required by the regulatory framework is listed. A concern was identified.

  15. Reactivity of The Ternary Pyrotechnic System Red Lead - Silicon - Ferric Oxide

    Directory of Open Access Journals (Sweden)

    S. R. Yoganarasimhan

    1987-01-01

    Full Text Available The reactivity of the ternary system of red lead, silicon and ferric oxide has been studied in comparison with the binary system red lead-silicon. Results from Differential Scanning Calorimetry (DSC in nitrogen environment and Differential Thermal Analysis (DTA in air have been supplemented with hot stage microscopy and combustion rate studies at about 30 atmospheres pressure. The ternary mixtures show three characteristic exotherms whose relative exothermicities vary with composition. DTA showed an unusual feature of a strong single exotherm at a certain critical mass which also varies with the composition. The critical mass could be reproduced within +-1.0 mg. Hot stage microscopy of the pyrotechnic samples revealed strong surface mobility during the reaction leading to the formation of a sintered product. Self sustained combustion rates of the samples show an inhibiting effect by ferric oxide.

  16. [Mechanism of groundwater As(V) removal with ferric flocculation and direct filtration].

    Science.gov (United States)

    Kang, Ying; Duan, Jin-Ming; Jing, Chuan-Yong

    2015-02-01

    The As removal process and mechanism from groundwater using ferric flocculation-direct filtration system was investigated using batch, field pilot tests, extended X-ray absorption fine structure ( EXAFS) spectroscopy, and charge-distribution multisite complexation (CD-MUSIC) model. The results showed that arsenate [As(V)] was the dominant As species in the groundwater with a concentration of 40 μg x L(-1). The treatment system could supply 64 984 L As-safe drinking water (concentration (5 mg x L(-1)). EXAFS and CD-MUSIC model indicated that As(V) was adsorbed onto ferric hydroxide via bidentate binuclear complexes in the pH range of 3 to 9.5, while formation of precipitate with Ca or Mg dominated the As removal at pH > 9.5. PMID:26031078

  17. Clinical application of on oral MR contrast agent ferric ammonium citrate

    International Nuclear Information System (INIS)

    Objective: To investigate the efficiency of oral ferric ammonium citrate (FAC) as a negative gastrointestinal contrast agent in magnetic resonance imaging. Methods: Altogether 50 patients were selected. MRCP was performed for twenty patients; MRU, for twenty patients; and pelvic MR, for ten patients. Image assessment was based on the difference between non-oral FAC and oral FAC by same parameters. Results: MRCP performed 15 minutes after oral FAC could delete effectively interference of liquid in the stomach and duodenum. MRU and pelvic MR performed 40 minutes after oral FAC could delete effectively interference of liquid in the jejunum, ileum and colon. Conclusion: The clinical application of oral ferric ammonium citrate as a negative gastrointestinal contrast agent can improve image quality significantly in MRCP, MRU and pelvic MR. (authors)

  18. Chemical Precipitation Synthesis of Ferric Chloride Doped Zinc Sulphide Nanoparticles and Their Characterization Studies

    CERN Document Server

    Theivasanthi, T; Alagar, M; 10.7598/cst2013.207

    2013-01-01

    Nanoparticles of Ferric Chloride doped ZnS has been synthesized by simple chemical precipitation method and characterized by XRD, SEM, UV-Vis analysis, Differential Thermal Analysis, Thermo Gravimetric Analysis and Differential Scanning Calorimetry. XRD patterns of the samples reveal particle size, specific surface area and the formation of cubic structure. The SEM images show that the cauliflower likes structure. Optical band gap values have been obtained from UV-Vis absorption spectra. It has also been found that energy band gap (Eg) increases with the increase in molar concentration of reactant solution. Thermal analysis measurement of the prepared sample shows that the thermal stability of pure ZnS is decreased due to increase in Ferric Chloride concentration. Undoped ZnS is more thermal stable when compared to FeCl3 doped ZnS.

  19. Conclusion on the peer review of the pesticide risk assessment of the active substance ferric phosphate

    OpenAIRE

    European Food Safety Authority

    2015-01-01

    The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State Germany, for the pesticide active substance ferric phosphate are reported. The context of the peer review was that required by Commission Regulation (EU) No 1141/2010 as amended by Commission Implementing Regulation (EU) No 380/2013. The conclusions were reached on the basis of the evaluation of the represe...

  20. Studies on the Synthesis and the Structure of Ferric Aluminum Magnesium Hydrotalcite-like Compounds

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The particles of ferric aluminum magnesium hydrotalcite-like compounds (Fe-Al-Mg_HTlc) were synthesized by co-precipitation method. It was found that when n(Fe)/n(Al+Mg+Fe)0.30, Al(OH)3 will emerge; when the molar ratio of Fe/(Fe+Al+Mg) >0.30, the amorphous composition will appear. Hence Fe3+ and Al3+ have no concentration superposition effect on the crystal structure of the samples.

  1. Ferric Citrate Hydrate as a Phosphate Binder and Risk of Aluminum Toxicity

    OpenAIRE

    Ajay Gupta

    2014-01-01

    Ferric citrate hydrate was recently approved in Japan as an oral phosphate binder to be taken with food for the control of hyperphosphatemia in patients with chronic kidney disease (CKD). The daily therapeutic dose is about 3 to 6 g, which comprises about 2 to 4 g of citrate. Oral citrate solubilizes aluminum that is present in food and drinking water, and opens the tight junctions in the intestinal epithelium, thereby increasing aluminum absorption and urinary excretion. In healthy animals d...

  2. Ferrous versus Ferric Oral Iron Formulations for the Treatment of Iron Deficiency: A Clinical Overview

    OpenAIRE

    Palacios Santiago

    2012-01-01

    Iron deficiency anaemia represents a major public health problem, particularly in infants, young children, pregnant women, and females with heavy menses. Oral iron supplementation is a cheap, safe, and effective means of increasing haemoglobin levels and restoring iron stores to prevent and correct iron deficiency. Many preparations are available, varying widely in dosage, formulation (quick or prolonged release), and chemical state (ferrous or ferric form). The debate over the advantages of ...

  3. Reactivity of The Ternary Pyrotechnic System Red Lead - Silicon - Ferric Oxide

    OpenAIRE

    S. R. Yoganarasimhan; O. S. Josyulu

    1987-01-01

    The reactivity of the ternary system of red lead, silicon and ferric oxide has been studied in comparison with the binary system red lead-silicon. Results from Differential Scanning Calorimetry (DSC) in nitrogen environment and Differential Thermal Analysis (DTA) in air have been supplemented with hot stage microscopy and combustion rate studies at about 30 atmospheres pressure. The ternary mixtures show three characteristic exotherms whose relative exothermicities vary with composition. DTA ...

  4. DETERMINATION OF TOTAL ANTIOXIDANT CAPACITY OF GREEN TEAS BY THE FERRIC REDUCING/ANTIOXIDANT POWER ASSAY

    OpenAIRE

    M. Hajimahmoodi, M. Hanifeh, M. R. Oveisi, N. Sadeghi, B. Jannat

    2008-01-01

    Green tea is one of the important sources of bioactive compounds which have been used in folk medicine for many centuries. This study aimed to compare in vitro antioxidant power of different types of green tea (Camellia sinensis). Antioxidant activity of methanolic (50%) extracts of five green tea samples was investigated according to Ferric reducing ability power method. Total phenolic contents were analyzed using a spectrophotometric technique, based on the Folin-ciocalteau reagent, and cal...

  5. Leaching of Arsenic from Granular Ferric Hydroxide Residuals under Mature Landfill Conditions

    OpenAIRE

    Ghosh, Amlan; Mukiibi, Muhammed; Sáez, A. Eduardo; Ela, Wendell P.

    2006-01-01

    Most arsenic bearing solid residuals (ABSR) from water treatment will be disposed in non-hazardous landfills. The lack of an appropriate leaching test to predict arsenic mobilization from ABSR creates a need to evaluate the magnitude and mechanisms of arsenic release under landfill conditions. This work studies the leaching of arsenic and iron from a common ABSR, granular ferric hydroxide, in a laboratory-scale column that simulates the biological and physicochemical conditions of a mature, m...

  6. 用微量铁盐培养基分离空肠弯曲菌的效果研究%Effect of trace ferric salt medium in separation of campylobacter jejuni

    Institute of Scientific and Technical Information of China (English)

    李宏科

    2013-01-01

    Objective. -To explore the effect of trace ferric salt medium in separation of Campylobacter jejuni, and find the optimal culture medium for Campylobacter jejuni. Methods: The experiment was carried out under the same condition, Campylobacter jejuni were isolated and cultured with five different culture mediums. The growth of the bacteria was observed, the comparative experiment research was performed by colony counting method. Results: After comparing these five mediums, it was found the detection rate of trace ferric salt medium was remarkably higher than other culture medium in separation of Campylobacter jejuni, but there was also omission, in order to improve the detection rate, Campylobacter jejuni should be based on the simultaneous usage of the brucella blood AGAR and trace ferric salt medium. Conclusion: Trace ferric salt medium can be used for the disease epidemiological survey and clinical inspection of Campylobacter jejuni. The Campylobacter jejuni grows rapidly with large bacterial colony in large quantities on ferric salt medium, which is suggested to apply in laboratories for its low cost and easy preparation.%目的:探索用微量铁盐培养基分离空肠弯曲菌,寻求分离空肠弯曲菌良好的培养基.方法:采用五种不同培养基,在相同条件下对空肠弯曲菌分离培养,观察其生长效果,用菌落计数法进行比较试验.结果:通过比较,发现含微量铁盐培养基对空肠弯曲菌分离效果好,检出率高.但也有遗漏,为了提高检出率,应与布氏菌血琼脂同时使用.结论:含微量铁盐培养基可用于空肠弯曲菌病流行病学调查和临床检验,空肠弯曲菌在该培养基上生长较快,菌落大,数量多,且制备简易、价廉,建议各实验室推广应用.

  7. Uptake behaviour of Cs(I) from aqueous solutions by hydrous ferric oxide and hydrous tungsten oxide: a radiotracer study

    International Nuclear Information System (INIS)

    The objective of the present study was to investigate the applicability of hydrous ferric oxide (HFO) and hydrous tungsten oxide (HTO) for the treatment of aqueous solutions containing Cs(I) at micro/tracers concentrations utilizing a radiotracer technique

  8. Potential of Alginate Encapsulated Ferric Saccharate Microemulsions to Ameliorate Iron Deficiency in Mice.

    Science.gov (United States)

    Mukhija, Kimmi; Singhal, Kirti; Angmo, Stanzin; Yadav, Kamalendra; Yadav, Hariom; Sandhir, Rajat; Singhal, Nitin Kumar

    2016-07-01

    Iron deficiency is one of the most prominent mineral deficiencies around the world, which especially affects large population of women and children. Development of new technologies to combat iron deficiency is on high demand. Therefore, we developed alginate microcapsule with encapsulated iron that had better oral iron bioavailability. Microcapsules containing iron with varying ratios of sodium alginate ferric(III)-saccharide were prepared using emulsification method. In vitro studies with Caco-2 cells suggested that newly synthesized microemulsions had better iron bioavailability as compared to commercially available iron dextran formulations. Ferrozine in vitro assay showed that alginate-encapsulated ferric galactose microemulsion (AFGM) had highest iron bioavailability in comparison to other four ferric saccharate microemulsions, namely AFGlM, AFMM, AFSM, and AFFM synthesized in our laboratory. Mice studies also suggested that AFGM showed higher iron absorption as indicated by increased serum iron, hemoglobin, and other hematopoietic measures with almost no toxicity at tested doses. Development of iron-loaded microemulsions leads to higher bioavailability of iron and can provide alternative strategies to treat iron deficiency. PMID:26637994

  9. Immobilization of arsenite and ferric iron by Acidithiobacillus ferrooxidans and its relevance to acid mine drainage.

    Science.gov (United States)

    Duquesne, K; Lebrun, S; Casiot, C; Bruneel, O; Personné, J-C; Leblanc, M; Elbaz-Poulichet, F; Morin, G; Bonnefoy, V

    2003-10-01

    Weathering of the As-rich pyrite-rich tailings of the abandoned mining site of Carnoulès (southeastern France) results in the formation of acid waters heavily loaded with arsenic. Dissolved arsenic present in the seepage waters precipitates within a few meters from the bottom of the tailing dam in the presence of microorganisms. An Acidithiobacillus ferrooxidans strain, referred to as CC1, was isolated from the effluents. This strain was able to remove arsenic from a defined synthetic medium only when grown on ferrous iron. This A. ferrooxidans strain did not oxidize arsenite to arsenate directly or indirectly. Strain CC1 precipitated arsenic unexpectedly as arsenite but not arsenate, with ferric iron produced by its energy metabolism. Furthermore, arsenite was almost not found adsorbed on jarosite but associated with a poorly ordered schwertmannite. Arsenate is known to efficiently precipitate with ferric iron and sulfate in the form of more or less ordered schwertmannite, depending on the sulfur-to-arsenic ratio. Our data demonstrate that the coprecipitation of arsenite with schwertmannite also appears as a potential mechanism of arsenite removal in heavily contaminated acid waters. The removal of arsenite by coprecipitation with ferric iron appears to be a common property of the A. ferrooxidans species, as such a feature was observed with one private and three collection strains, one of which was the type strain. PMID:14532077

  10. Enhanced coagulation of ferric chloride aided by tannic acid for phosphorus removal from wastewater.

    Science.gov (United States)

    Zhou, Yunan; Xing, Xin-Hui; Liu, Zehua; Cui, Liwen; Yu, Anfeng; Feng, Quan; Yang, Haijun

    2008-05-01

    Phosphorus removal from wastewater is of great importance. In the present study, ferric chloride was selected as the coagulant, and tannic acid (TA), a natural polymer, as the coagulant aid to develop an effective coagulation process with the emphasis of phosphorus recovery from different types of wastewater. The results showed that TA can accelerate the settling speed by forming flocs with large size, reduce the residual Fe(III) to eliminate the yellow color caused by Fe(III), and slightly increase the phosphorus removal efficiency. The precipitate formed by TA-aided coagulation showed the advantage of releasing phosphorus faster than ferric phosphate, indicating the possibility of phosphorus recovery from wastewater as slow release fertilizer. To further understand the structural characteristics of the precipitate, analytical techniques such as Raman spectroscopy, X-ray photoelectron spectroscopy and matrix-assisted laser desorption ionization-time of flight mass spectrometry were employed. The analytical results indicated that TA-Fe-P complex was formed during the coagulation/flocculation processes. Solid phase in the precipitate consisted of TA-Fe-P complex, Fe-TA complex and/or ferric hydroxyphosphate. PMID:18395769

  11. Immobilization of Arsenite and Ferric Iron by Acidithiobacillus ferrooxidans and Its Relevance to Acid Mine Drainage

    Science.gov (United States)

    Duquesne, K.; Lebrun, S.; Casiot, C.; Bruneel, O.; Personné, J.-C.; Leblanc, M.; Elbaz-Poulichet, F.; Morin, G.; Bonnefoy, V.

    2003-01-01

    Weathering of the As-rich pyrite-rich tailings of the abandoned mining site of Carnoulès (southeastern France) results in the formation of acid waters heavily loaded with arsenic. Dissolved arsenic present in the seepage waters precipitates within a few meters from the bottom of the tailing dam in the presence of microorganisms. An Acidithiobacillus ferrooxidans strain, referred to as CC1, was isolated from the effluents. This strain was able to remove arsenic from a defined synthetic medium only when grown on ferrous iron. This A. ferrooxidans strain did not oxidize arsenite to arsenate directly or indirectly. Strain CC1 precipitated arsenic unexpectedly as arsenite but not arsenate, with ferric iron produced by its energy metabolism. Furthermore, arsenite was almost not found adsorbed on jarosite but associated with a poorly ordered schwertmannite. Arsenate is known to efficiently precipitate with ferric iron and sulfate in the form of more or less ordered schwertmannite, depending on the sulfur-to-arsenic ratio. Our data demonstrate that the coprecipitation of arsenite with schwertmannite also appears as a potential mechanism of arsenite removal in heavily contaminated acid waters. The removal of arsenite by coprecipitation with ferric iron appears to be a common property of the A. ferrooxidans species, as such a feature was observed with one private and three collection strains, one of which was the type strain. PMID:14532077

  12. Evaluation of antioxidant status in Streptozotocin-induced diabetic rats by Ferric reducing ability of plasma assay

    OpenAIRE

    Zarban A; Doosti M; Esteghamati A; Allameh A

    2000-01-01

    Enhanced oxidative stress in diabetes mellitus may contribute to the pathogenesis of diaetic complications. In this article, the stress oxidative generation has been studied in experimental diabetes by ferric reducing ability of plasma assay, a sensitive and simple method, and by other oxidative damage markers. The ferric reducing ability of plasma values as a total antioxidant capacity were significantly decreased at the 3th 4th weeks of stuy ( P<0.02), while the thiobarbituric acid react...

  13. Electromagnetism of Bacterial Growth

    Science.gov (United States)

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  14. Development of a PCR protocol for the detection of Aeromonas salmonicida in fish by amplification of the fstA (ferric siderophore receptor) gene.

    Science.gov (United States)

    Beaz-Hidalgo, Roxana; Magi, Gian Enrico; Balboa, Sabela; Barja, Juan L; Romalde, Jesús L

    2008-04-30

    The aims of the study were to evaluate a new PCR protocol designed to detect Aeromonas salmonicida in fish tissues and to develop a non-destructive method for the diagnosis of furunculosis. A set of primers (Fer3, Fer4), flanking a fragment of the fstA gene (coding for the ferric-siderophore receptor) was designed, showing to be sensitive and specific. When compared to PCR methods previously reported, the new protocol recognized all the 69 A. salmonicida strains evaluated, with no cross-reactions with the other bacterial species analysed. Sensitivity assays were performed in fish tissues seeded with serial dilutions of pure cultures of A. salmonicida and mixed cultures of this bacterium with Vibrio anguillarum and Aeromonas hydrophila. Detection limits obtained were of 60 and 450 bacterial cells 100 mg(-1) of tissue, respectively. Mucus and blood were evaluated in order to develop a non-destructive tool to detect the pathogen. The detection limits in seeded mucus and blood samples were 2.5 x 10(2) and 1 x 10(5) bacterial cells mL(-1), respectively. When the method was used to detect A. salmonicida in asymptomatic wild salmon, four samples of mucus and six of blood were positive, corresponding to 6 out of the 31 fish examined, whereas only one of the samples resulted positive by culture methods. It is concluded that the PCR protocol evaluated is fast, specific and sensitive to detect A. salmonicida in infected and asymptomatic fish, and will be helpful for the control of the disease through the prompt detection of carriers within fish populations. PMID:18035507

  15. Addition of citrate to Acidithiobacillus ferrooxidans cultures enables precipitate-free growth at elevated pH and reduces ferric inhibition.

    Science.gov (United States)

    Li, Xiaozheng; Mercado, Roel; Kernan, Timothy; West, Alan C; Banta, Scott

    2014-10-01

    Acidithiobacillus ferrooxidans is an acidophilic chemolithoautotroph that is important in biomining and other biotechnological operations. The cells are able to oxidize inorganic iron, but the insolubility and product inhibition by Fe(3+) complicates characterization of these cultures. Here we explore the growth kinetics of A. ferrooxidans in iron-based medium in a pH range from 1.6 to 2.2. It was found that as the pH was increased from 1.6 to 2.0, the maintenance coefficient decreased while both the growth kinetics and maximum cell yield increased in the precipitate-free, low Fe(2+) concentration medium. In higher iron media a similar trend was observed at low pH, but the formation of precipitates at higher pH (2.0) hampered cell growth and lowered the specific growth rate and maximum cell yield. In order to eliminate ferric precipitates, chelating agents were introduced into the medium. Citric acid was found to be relatively non-toxic and did not appear to interfere with iron oxidation at a maximum concentration of 70 mM. Inclusion of citric acid prevented precipitation and A. ferrooxidans growth parameters resumed their trends as a function of pH. The addition of citrate also decreased the apparent substrate saturation constant (KS ) indicating a reduction in the competitive inhibition of growth by ferric ions. These results indicate that continuous cultures of A. ferrooxidans in the presence of citrate at elevated pH will enable enhanced cell yields and productivities. This will be critical as these cells are used in the development of new biotechnological applications such as electrofuel production. PMID:24771134

  16. Ferric ammonium citrate as a positive bowel contrast agent for MR imaging of the upper abdomen

    International Nuclear Information System (INIS)

    Purpose: To evaluate the safety and diagnostic efficacy of two different doses of ferric ammonium citrate as a paramagnetic oral contrast agent for MR imaging of the upper abdomen. Material and methods: Ninety-nine adult patients referred for MR imaging for a known or suspected upper abdominal pathology were included in this randomized multicenter double-blind clinical trial. Imaging was performed with spin-echo (T1- and T2-weighted) and gradient-echo (T1-weighted) techniques before and after administration of either 1200 mg or 2400 mg of ferric ammonium citrate dissolved in 600 ml of water. Safety analysis included monitoring of vital signs, assessment of adverse events, and laboratory testing. Efficacy with regard to organ distension, contrast distribution, bowel enhancement and delineation of adjacent structures was graded qualitatively. Results: No serious adverse events were reported for either of the two concentrations. A total of 31 minor side effects were noted, of which significantly more occurred in the higher dose group (p<0.01). The diagnostic confidence in defining or excluding disease was graded as better after contrast administration for 48% of all images. Marked or moderate enhancement of the upper gastrointestinal tract was achieved at both doses in 69.5% of cases with no evident difference between the two doses. The higher dose tended to show better results in terms of the contrast assessment parameters. Conclusion: Ferric ammonium citrate is a safe and effective oral contrast agent for MR imaging of the upper abdomen at two different dose levels. The higher dose showed a tendency toward better imaging results while the lower dose caused significantly fewer side effects. Therefore, the 1200 mg dose can be recommended in view of the risk-to-benefit ratio. (orig.)

  17. FeII induced mineralogical transformations of ferric oxyhydroxides into magnetite of variable stoichiometry and morphology

    International Nuclear Information System (INIS)

    The Mössbauer spectroscopy was used to monitor the mineralogical transformations of ferrihydrite (F), lepidocrocite (L) and goethite (G) into magnetite as a function of aging time. Ferric oxyhydroxides were reacted with soluble FeII and OH– in stoichiometric amounts to form magnetite at an initial pH of ∼9.7. Observed transformation extent into magnetite followed the order: F>L>G with almost 30% of untransformed G after 1 month. The departure from stoichiometry, δ, of magnetite (Fe3−δO4) generated from F (δ∼0.04) and L (δ∼0.05) was relatively low as compared to that in magnetite from G (δ∼0.08). The analysis by transmission electron microscopy and BET revealed that generated magnetite was also different in terms of morphology, particle size and surface area depending on the nature of initial ferric oxyhydroxide. This method of preparation is a possible way to form nano-sized magnetite. - Graphical abstract: Mössbauer spectrum of the early stage of magnetite formation formed from the interaction of adsorbed FeII species with goethite. Highlights: ► Ferric oxides were reacted with hydroxylated FeII to form magnetite. ► Magnetite formation was quantified as a function of aging time. ► Complete transformation of ferrihydrite and lepidocrocite was achieved. ► Almost 70% of initial goethite was transformed. ► Resulting magnetites have differences in stoichiometry and morphological properties.

  18. Comparison of Clinical and Radiographic Success Rate of Ferric Sulfate Pulpotomy Method in Second Primary Molars Using Zinc Oxide Eugenol and Zinc Polycarboxylate Cements.

    OpenAIRE

    N Ramazani; H. Neamatollahi

    2008-01-01

    Introduction: Ferric sulfate pulpotomy is a safe and effective method of the pulpotomy of primary teeth. But the results of different studies indicate low success rate of ferric sulfate pulpotomy in comparison to Formocresol pulpotomy and a portion of these failures may be related to stimulating and harmful effects of zinc oxide Eugenol paste. The aim of this study was to determine and compare the clinical and radiographic success rate of ferric sulfate pulpotomy of primary molars with zinc o...

  19. Ibuprofen impairs allosterically peroxynitrite isomerization by ferric human serum heme-albumin.

    OpenAIRE

    Ascenzi, Paolo; di Masi, Alessandra; Coletta, Massimo; Ciaccio, Chiara; Fanali, Gabriella; Nicoletti, Francesco P; Smulevich, Giulietta; Fasano, Mauro

    2011-01-01

    Human serum albumin (HSA) participates in heme scavenging; in turn, heme endows HSA with myoglobin-like reactivity and spectroscopic properties. Here, the allosteric effect of ibuprofen on peroxynitrite isomerization to NO3− catalyzed by ferric human serum heme-albumin (HSA-heme-Fe(III)) is reported. Data were obtained at 22.0 °C. HSA-heme-Fe(III) catalyzes peroxynitrite isomerization in the absence and presence of CO2; the values of the second order catalytic rate constant (kon) are 4.1 × 10...

  20. Statistical modeling for Toluene Diisocyanate and Polypropylene Glycol Polymerization with Ferric Acetylacetonate as Catalyst

    International Nuclear Information System (INIS)

    Polyurethane elastomer was synthesized with propylene glycol and toluene diisocyanate with ferric acetylacetonate catalyst. This polymerization was modeled using the kinetic equations. The number and weight average degrees of polymerization (DPw and DPn), the number and weight average molecular weights (Mw and Mn) and the polydispersity index parameters were found and tested as function of time and conversion and they were finally compared with GPC laboratory and experimental results. The effect of concentration of the catalyst and the addition sequence of starting materials and catalyst on Mn, Mw, DPI and Mz/Mn are reported and discussed

  1. Solute-Solvent Interactions and High Spin ⇌ Low Spin Transitions in Ferric Dithiocarbamates

    Science.gov (United States)

    Ganguli, P.

    1985-01-01

    The HS ⇌ LS transition in ferric dithiocarbamates in a number of solvents has been investigated using NMR and is interpreted in terms of preferential solvation or second co-ordination sphere reorganisation effects. These studies clearly demonstrate that neglect of pseudo contact shifts can lead to erroneous conclusions about the spin delocalisation mechanisms. The spin derealization in these systems is by direct σ-delocalization along the alkyl chain. The As values of 2T2 and 6A1 states have the same sign.

  2. Application of ferric enriched biochar to capture N and P from greywater

    OpenAIRE

    Basnet, Mukesh

    2015-01-01

    A filtration test was carried out to study the nutrients (N and P) adsorption capacity of two types of biochar, i.e. the biochars from two different companies, Biolan Oy and RKP Hiili. Both biochars were used in two forms: pure and enriched with ferric sulphate (FS). It is well known that nitrogen (N) and phosphorous (P) are the essential nutrients for the plant production; however if these nutrients are used in excessive amounts, they can leach to groundwater and streams polluting the f...

  3. FeII induced mineralogical transformations of ferric oxyhydroxides into magnetite of variable stoichiometry and morphology

    OpenAIRE

    Usman, Muhammad; Abdelmoula, Mustapha; Hanna, Khalil; Grégoire, Brian; Faure, Pierre; Ruby, Christian

    2012-01-01

    The Mössbauer spectroscopy was used to monitor the mineralogical transformations of ferrihydrite (F), lepidocrocite (L) and goethite (G) into magnetite as a function of aging time. Ferric oxyhydroxides were reacted with soluble FeII and OH- in stoichiometric amounts to form magnetite at an initial pH of  9.7. Observed transformation extent into magnetite followed the order: F > L > G with almost 30 % of untransformed G after 1 month. The departure from stoichiometry, δ, of magnetite (Fe3-δO4...

  4. Report on assessment of the mechanism of bacterially assisted oxidation of pyritic uranium tailings

    International Nuclear Information System (INIS)

    The oxidation of pyritic minerals has been shown to be catalyzed by the presence of iron- and sulphur-oxidizing bacteria. Thiobacillus ferroxidans plays the most significant role in the formation and propagation of acidic conditions. Optimum growth conditions for the T. ferroxidans occurs at a temperature of 35 degrees C and pH of 2 to 3. Bacterially assisted oxidation of pyrite involves both direct and indirect contact mechanisms. The direct contact mechanism entails enzymatic oxidation of the insoluble sulphide moiety. The indirect mechanism involves bacterial oxidation of the dissolved ferrous component to the ferric state. The ferric iron, in turn, acts as the prime oxidant of pyrite and is reduced to ferrous iron. The re-oxidation of the dissolved ferrous component which is catalyzed by bacterial activity, completes the cyclic process. The rate of bacterial oxidation is affected by: the geochemistry and reactivity of the pyritic material; the amount of pyrite present in the waste material and the exposed surface area of the pyritic component; the availability of oxygen and carbon dioxide; the pH and temperature of the leach solution; and the presence (or absence) of organic inhibitors. Of the above factors, oxygen has been frequently identified as the rate limiting reactant in tailings

  5. Geobacter bremensis sp. nov. and Geobacter pelophilus sp. nov., two dissimilatory ferric-iron-reducing bacteria.

    Science.gov (United States)

    Straub, K L; Buchholz-Cleven, B E

    2001-09-01

    Two strictly anaerobic, dissimilatory ferric-iron-reducing bacteria, strains Dfr1T and Dfr2T, were isolated from freshwater mud samples with ferrihydrite as electron acceptor. Both strains also grew by reducing Mn(IV), S0 and fumarate. Electron donors used by strains Dfr1T and Dfr2T for growth with ferric iron as electron acceptor included hydrogen, formate, acetate, pyruvate, succinate, fumarate and ethanol. An affiliation with the family Geobacteraceae was revealed by comparative analysis of 165 rRNA gene sequences. Strains Dfr1T and Dfr2T shared 92.5% sequence identity and their closest known relative was Geobacter sulfurreducens, with approximately 93% sequence identity. Cultures and colonies of strains Dfr1T and Dfr2T were intensely red in colour, due to the presence of c-type cytochromes. On the basis of physiological and phylogenetic data, strain Dfr1T (= DSM 12179T = OCM 796T) is described as Geobacter bremensis sp. nov. and strain Dfr2T (= DSM 12255T = OCM 797T) as Geobacter pelophilus sp. nov. PMID:11594612

  6. Effects of minerals in ferric bauxite on sodium carbonate decomposition and volatilization

    Institute of Scientific and Technical Information of China (English)

    胡文韬; 王化军; 刘欣伟; 孙传尧

    2015-01-01

    Direct reduction is an emerging technology for ferric bauxite utilization. However, because of sodium volatilization, its sodium carbonate consumption is considerably higher than that in ordinary bauxite processing technology. TG-DSC and XRD were applied to detecting phase transformation and mass loss in direct reduction to reveal the mechanism on sodium volatilization. The results show that the most significant influence factor of ferric bauxite on sodium volatilization in direct reduction system is its iron content. Sodium volatilization is probably ascribed to the instability of amorphous substances structure. Amorphous substances are the intermediate-products of the reaction, and the volatilization rate of sodium increases with its generating rate. These amorphous substances are volatile, thus, more sodium is volatilized with its generation. A small amount of amorphous substances are generated in the reaction between Na2CO3and Al2O3; thus, only 3.15% of sodium is volatilized. Similarly, the volatilization rate is 1.87% in the reaction between Na2CO3and SiO2. However, the volatilization rate reaches 7.64% in the reaction between Na2CO3 and Fe2O3 because of the generation of a large amount of amorphous substances.

  7. Combining Ferric Salt and Cactus Mucilage for Arsenic Removal from Water.

    Science.gov (United States)

    Fox, Dawn I; Stebbins, Daniela M; Alcantar, Norma A

    2016-03-01

    New methods to remediate arsenic-contaminated water continue to be studied, particularly to fill the need for accessible methods that can significantly impact developing communities. A combination of cactus mucilage and ferric (Fe(III)) salt was investigated as a flocculation-coagulation system to remove arsenic (As) from water. As(V) solutions, ferric nitrate, and mucilage suspensions were mixed and left to stand for various periods of time. Visual and SEM observations confirmed the flocculation action of the mucilage as visible flocs formed and settled to the bottom of the tubes within 3 min. The colloidal suspensions without mucilage were stable for up to 1 week. Sample aliquots were tested for dissolved and total arsenic by ICP-MS and HGAFS. Mucilage treatment improved As removal (over Fe(III)-only treatment); the system removed 75-96% As in 30 min. At neutral pH, removal was dependent on Fe(III) and mucilage concentration and the age of the Fe(III) solution. The process is fast, achieving maximum removal in 30 min, with the majority of As removed in 10-15 min. Standard jar tests with 1000 μg/L As(III) showed that arsenic removal and settling rates were pH-dependent; As removal was between 52% (high pH) and 66% (low pH). PMID:26824141

  8. Novel regeneration method for phosphate loaded granular ferric (hydr)oxide--a contribution to phosphorus recycling.

    Science.gov (United States)

    Kunaschk, Marco; Schmalz, Viktor; Dietrich, Norman; Dittmar, Thomas; Worch, Eckhard

    2015-03-15

    At a progressive rate, small wastewater treatment plants in rural areas need to be equipped with an additional phosphorus removal stage in order to achieve a good chemical status in the receiving natural water bodies. A conventional regeneration method for ferric (hydr)oxides such as phosphate specific adsorbents, which can be applied to remove and recover phosphorus in fixed bed filters, was investigated and improved. It was shown that a loss of up to 85% of the initial capacity can be observed when regeneration with 1 M NaOH is implemented. The losses are caused by surface blocking with different calcium-containing compounds as revealed by an EDX analysis. These blocking compounds could be removed completely with an additional acidic regeneration step at pH = 2.5. During the alkaline desorption that followed, complete phosphorus removal and a full recovery of the adsorption capacity were achieved for goethite-rich Bayoxide(®) E 33 HC (E33HC) and akaganéite-rich GEH(®) 104 (GEH). The regeneration procedure was repeated up to eight times without any signs of further decline in the phosphate adsorption capacity or any changes in the specific surface area or pore size distribution of the adsorbent. In contrast to GEH and E33HC, ferric hydroxide- and calcite-rich FerroSorp(®) Plus (FSP) was partly dissolved during acid treatment. PMID:25618522

  9. Intravenous ferric carboxymaltose for the treatment of iron deficiency anemia

    Directory of Open Access Journals (Sweden)

    João Ricardo Friedrisch

    2015-12-01

    Full Text Available ABSTRACT Nutritional iron deficiency anemia is the most common deficiency disorder, affecting more than two billion people worldwide. Oral iron supplementation is usually the first choice for the treatment of iron deficiency anemia, but in many conditions, oral iron is less than ideal mainly because of gastrointestinal adverse events and the long course needed to treat the disease and replenish body iron stores. Intravenous iron compounds consist of an iron oxyhydroxide core, which is surrounded by a carbohydrate shell made of polymers such as dextran, sucrose or gluconate. The first iron product for intravenous use was the high molecular weight iron dextran. However, dextran-containing intravenous iron preparations are associated with an elevated risk of anaphylactic reactions, which made physicians reluctant to use intravenous iron for the treatment of iron deficiency anemia over many years. Intravenous ferric carboxymaltose is a stable complex with the advantage of being non- dextran-containing and a very low immunogenic potential and therefore not predisposed to anaphylactic reactions. Its properties permit the administration of large doses (15 mg/kg; maximum of 1000 mg/infusion in a single and rapid session (15-minute infusion without the requirement of a test dose. The purpose of this review is to discuss some pertinent issues in relation to the history, pharmacology, administration, efficacy, and safety profile of ferric carboxymaltose in the treatment of patients with iron deficiency anemia.

  10. Crystallization and preliminary X-ray studies of ferric uptake regulator from Magnetospirillum gryphiswaldense

    International Nuclear Information System (INIS)

    Crystals of apo and SeMet ferric uptake regulator from the magnetotactic bacterium M. gryphiswaldense MSR-1 were obtained and optimized to obtain high-quality diffraction data. Diffraction data sets were collected and processed at 1.58 and 1.9 Å resolution, respectively. Magnetosomes in magnetotactic bacteria have been widely used in studies of magnetic domains and in commercial applications. The iron content of magnetotactic bacteria is ∼100 times higher than that of Escherichia coli. Magnetospirillum gryphiswaldense MSR-1 can still take up iron even at high intracellular concentrations. Ferric uptake regulator (Fur) is a global iron-responsive regulator that affects magnetosome formation, iron transport and oxygen metabolism. However, the mechanism of iron uptake and homeostasis by M. gryphiswaldense MSR-1 Fur is not clear. Here, the expression, purification and crystallization of apo and SeMet Fur from M. gryphiswaldense MSR-1 are reported. The crystals belonged to space group C2. Matthews coefficient analysis and size-exclusion chromatography showed that the asymmetric unit probably contains one dimer of Fur. Diffraction data were optimized to 1.58 Å resolution for apo Fur and to 1.9 Å resolution for SeMet Fur

  11. Bacterial Nail Infection (Paronychia)

    Science.gov (United States)

    ... of nail infection is often caused by a bacterial infection but may also be caused by herpes, a ... to a type of yeast called Candida , or bacterial infection, and this may lead to abnormal nail growth. ...

  12. Evaluation of antioxidant status in Streptozotocin-induced diabetic rats by Ferric reducing ability of plasma assay

    Directory of Open Access Journals (Sweden)

    Zarban A

    2000-10-01

    Full Text Available Enhanced oxidative stress in diabetes mellitus may contribute to the pathogenesis of diaetic complications. In this article, the stress oxidative generation has been studied in experimental diabetes by ferric reducing ability of plasma assay, a sensitive and simple method, and by other oxidative damage markers. The ferric reducing ability of plasma values as a total antioxidant capacity were significantly decreased at the 3th 4th weeks of stuy ( P<0.02, while the thiobarbituric acid reacting substances (TBARS levels in plasma wre increased at the 3rd and the 4 th weeks ( (P<0.05. the plasma carbonyl groups (PCG were not affected, and total thiol groups (TG were significantly decreased at the 4th week (P<0.02.In conclusion the present study suggests that hyperglycemia in diabetes leads to oxidative stress, as shown by ferric reducting ability of plasma assay. This method is rapid, simple and economic

  13. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will...

  14. Gold Nanoparticle-based Surface-enhanced Raman Scattering Fe(III) Ion Sensor

    International Nuclear Information System (INIS)

    We performed density functional theory (DFT) calculations of 4-aminobenzo-15-crown-5 (4AB15C5) in conjugation with 4-mercaptobenzoic acid (4MCB) with the polarizable continuum model (PCM) while considering the aqueous media. After specific binding of the ferric ion onto the 4MCB.4AB15C5 compound, the Raman frequencies and intensities were estimated by DFT calculations with the PCM. It was predicted that the Raman intensities became significantly increased upon binding of the ferric ion. 4MCB.4AB15C5 could be assembled on gold nanoparticles (AuNPs) via the cleavage of the thiol bond. Colorimetric and UV.Vis absorption spectroscopy indicated that AuNPs became significantly aggregated in the presence of 1.10 mM of the ferric ion. Surface-enhanced Raman scattering (SERS) of 4MCB.4AB15C5 was used to identify the dissimilar spectral behaviors that yield a difference in intensity in the presence of the ferric ion. These changes were not observed in the other biological ions Zn2+, Mn2+, Fe2+, Na+, K+, Ca2+, Mg2+, NH4+, and Co2+. This study indicated that 4AB15C5 could be used to detect ferric ions in aqueous AuNP solutions by a combined method of colorimetric, UV.Vis absorption, and Raman spectroscopy. AuNPs.[4MCB. 4AB15C5] can thus be utilized as a selective turn-on sensor to Fe3+ in aqueous solutions above 1 mM.

  15. Application of acid pugging and ferric salts leaching on West Central Sinai uraniferrous siltstone

    International Nuclear Information System (INIS)

    Application of acid pugging as well as leaching with ferric salts [FeC13 and Fe2(SO4)3] methods were investigated to overcome the solid - liquid separation problem normally faced in the conventional acid leaching methods. The applied methods minimized the leachant consumption and leaching time. In addition, the radium removal during the ferric salts leaching was actually taken in consideration to meet the environmental requirements. The acid pug leaching experiments were conducted by using 10 gm concentrated H2SO4 (equal to 200 kg/ton in the conventional leaching methods) upon 50 gm sample fractions. The pug was cured at 110oC for 1.5 hours. After curing, agitation leaching was performed with distilled water using a solid - liquid ratio of 1/3 for 6 hours at room temperature. The obtained leaching efficiencies were 95.7% for U, 97.3% for Cu and almost complete leaching for Mn. This method could also be applied at the mine sites on ores when making use of the sunlight for only a few hours a day. Bench scale studies proved that when applying the curing step in the sunlight for 4 hours using the other optimum operating conditions, U dissolution efficiency reached about 85.6% and about 86.6% for Cu but it was only about 25.7% for Mn. In comparison, application of ferric salts leaching on the ore proved that 93.3% and 37% U dissolutions were obtained when using 100 kg/t Fe2(SO4)3 versus FeC13, respectively. With respect to both Cu and Mn leaching efficiencies, it was found that higher recoveries were obtained when using FeC13 than when using Fe2(SO4)3. Tests were performed to improve the poor uranium leaching efficiencies in the FeC13 leaching method by the addition of HC1 which acted as initiating reagent. The results indicated that by adding 40 kg/t FeC13 an improvement of the uranium leaching was obtained, 92.2%. (author)

  16. SYNTESIS OF THE COMPLEXES OF MACROPOROUS SULFONATED RESINS WITH FERRIC CHLORIDE AND THEIR CATALYTIC BEHAVIOR FOR SETERIFICATION OF ACETIC ACID WITH BUTANOL

    Institute of Scientific and Technical Information of China (English)

    HuangWenqiang; HouXin; 等

    1997-01-01

    The complex resins prepared from macroporous sulfonated resin D72(H+ form) with ferric chloride or ferric chloride hexahydrate have both sites of Bronsted acid and Lewis acid.In the catalysis of exterification of acetic acid with butanol the complex resins show to have much higher catalytic activity than that of its matrix.a conventional sulfonated cation exchange resin D72.

  17. Ferric Citrate Reduces Intravenous Iron and Erythropoiesis-Stimulating Agent Use in ESRD.

    Science.gov (United States)

    Umanath, Kausik; Jalal, Diana I; Greco, Barbara A; Umeukeje, Ebele M; Reisin, Efrain; Manley, John; Zeig, Steven; Negoi, Dana G; Hiremath, Anand N; Blumenthal, Samuel S; Sika, Mohammed; Niecestro, Robert; Koury, Mark J; Ma, Khe-Ni; Greene, Tom; Lewis, Julia B; Dwyer, Jamie P

    2015-10-01

    Ferric citrate (FC) is a phosphate binder with shown efficacy and additional effects on iron stores and use of intravenous (iv) iron and erythropoiesis-stimulating agents (ESAs). We provide detailed analyses of changes in iron/hematologic parameters and iv iron/ESA use at time points throughout the active control period of a phase 3 international randomized clinical trial. In all, 441 subjects were randomized (292 to FC and 149 to sevelamer carbonate and/or calcium acetate [active control (AC)]) and followed for 52 weeks. Subjects on FC had increased ferritin and transferrin saturation (TSAT) levels compared with subjects on AC by week 12 (change in ferritin, 114.1±29.35 ng/ml; Ptreatment with FC as a phosphate binder results in increased iron parameters apparent after 12 weeks and reduces iv iron and ESA use while maintaining hemoglobin over 52 weeks, with a safety profile similar to that of available binders. PMID:25736045

  18. Photocatalytic Reduction of Hexavalent Chromium Induced by Photolysis of Ferric/tartrate Complex

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xianghua; Ding, Shimin; Zhang, Lixian [Yangtze Normal Univ., Fuling (China)

    2012-11-15

    Photocatalytic reduction of hexavalent chromium (Cr(VI)) in ferric-tartrate system under irradiation of visible light was investigated. Effects of light resources, initial pH value and initial concentration of various reactants on Cr(VI) photocatalytic reduction were studied. Photoreaction kinetics was discussed and a possible photochemical pathway was proposed. The results indicate that Fe(III)-tartrate system is able to rapidly and effectively photocatalytically reduce Cr(VI) utilizing visible light. Initial pH variations results in the concentration changes of Fe(III)-tartrate complex in this system, and pH at 3.0 is optimal for Cr(VI) photocatalytic reduction. Efficiency of Cr(VI) photocatalytic reduction increases with increasing initial concentrations of Cr(VI), Fe(III) and tartrate. Kinetics analysis indicates that initial Fe(III) concentration affects Cr(VI) photoreduction most significantly.

  19. Micromorphology, photophysical and electrical properties of pristine and ferric chloride doped poly(3-hexylthiophene) films

    International Nuclear Information System (INIS)

    Poly(3-hexylthiophene) (P3HT), synthesized by chemical oxidative polymerization at ∼258 K, has been probed by Fourier transform infrared (FT-IR), ultraviolet-visible (UV-vis) spectroscopy, scanning electron microscopy (SEM) and by measuring the temperature dependence of DC conductivity (σ DC) in both its pristine and partially doped state. FT-IR and UV-vis studies suggest the formation of polaronic charge species in both pristine and partially doped P3HT. SEM of pristine P3HT film exhibits the formation of randomly distributed polymer fibrils whereas ferric chloride doped P3HT film shows the formation of dopant islands (size ∼500 nm), some of which adhered to the polymer fibrils. The temperature dependence of DC conductivity in the range 77-300 K is well explained by Mott's 3-dimensional variable range hopping (3D-VRH) model

  20. MANAGING POSTPARTUM ANEMIA WITH FERRIC CARBOXYMALTOSE AT TERTIARY LEVEL HOSPITAL : A RETROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Surekha Narayan

    2015-05-01

    Full Text Available OBJECTIVE: 1 To evaluate safety and efficacy of Ferric Carboxymaltose (FCM in the treatment of postpartum anaemia (PPA . 2 To assess the increase in Hb level after FCM. Design: This is a retrospective, study consisted of 121 women admitted in obstetrics ward with postpartum anemia who received FCM. MATERIALS & METHODS: Clinical records of patients with postpartum anemia who received FCM were analysed. RESULTS: Mean haemoglobin (Hb increased significantly from baseline by 2.76 ± 1.00 g/dl (n=121; p<0.0001 . The change in Hb was maximum in patients having baseline Hb 6.1 - 8g/dL. Only 2 patients (1.65% reported treatment - related adverse events headache, n=1; rash/urticaria, n=1]. CONCLUSION: FCM was effective in improving H b in PPA patients & was well tolerated .

  1. Fayalite Oxidation Processes: Experimental Evidence for the Stability of Pure Ferric Fayalite?

    Science.gov (United States)

    Martin, A. M.; Righter, K.; Keller, L. P.; Medard, E.; Devouard, B.; Rahman, Z.

    2011-01-01

    Olivine is one of the most important minerals in Earth and planetary sciences. Fayalite Fe2(2+)SiO4, the ferrous end-member of olivine, is present in some terrestrial rocks and primitive meteorites (CV3 chondrites). A ferric fayalite (or ferri-fayalite), Fe(2+) Fe2(3+)(SiO4)2 laihunite, has been reported in Earth samples (magnetite ore, metamorphic and volcanic rocks...) and in Martian meteorites (nakhlites). Laihunite was also synthesized at 1 atmosphere between 400 and 700 C. We show evidence for the stability of a pure ferrifayalite end-member and for potential minerals with XFe(3+) between 2/3 and 1.

  2. Design, fabrication and cold tests of a super ferric octupole corrector for the LHC

    International Nuclear Information System (INIS)

    In the corrections scheme of the LHC it is planed to install octupole corrector magnets in the short straight section of the lattice. Initially these correctors were distributed windings on the cold bore tube nested in the tuning quadrupoles. The latter being suppressed a new compact super ferric design was chosen for the octupole prototype, suitable for a two-in-one configuration. This prototype was designed by CERN and CEDEX/Spain, built at INDAR/Spain and tested at CEDEX. The paper reports on the design of the prototype, describes the fabrication and assembly and presents the measurement results. Special interest has been taken to design a simple and compact magnet, easy to fabricate and training free below nominal field. First results show the feasibility of the solution wich will be finally confirmed by magnetic measurement. (Author) 4 refs

  3. Experimental radiation synovectomy in rabbit knee with holmium-166 ferric hydroxide macroaggregate

    International Nuclear Information System (INIS)

    Holmium-166 ferric hydroxide macroaggregate (Ho-166 FHMA) particles possess two important properties for radiosynovectomy; relatively short half-life of the radioisotope and appropriate carrier size. Both these minimize radioactive leakage from the treated joint. This study was conducted to assess the effects of Ho-166 FHMA on synovium and synovial fluid in rabbit knee joints. Whole-knee autoradiography was utilized to determine distribution of radioactivity after intra-articular Ho-166 FHMA injection. Intra-articular injection of Ho-166 FHMA resulted in focal acute radiation necrosis in synovial lining but no hyperplasia of synoviocytes. Later, subsynovial fibrosis became evident. White blood cell and total protein levels in the joint fluid were elevated because of intra-articular inflammation due to the acute effects of radiation. Whole knee autoradiograms showed uneven distribution of the radionuclide along the synovium and extraarticular leakage on the third day after treatment

  4. Application of ferric sludge to immobilize leachable mercury in soils and concrete.

    Science.gov (United States)

    Zhuang, J Ming; Walsh, T; Lam, T; Boulter, D

    2003-11-01

    A Hg-contaminated site in B.C. Province, Canada was caused by the previous operation of Hg-cell in chlor-alkali process for over 25 years. The soils and groundwater at the site are highly contaminated with mercury. An analysis of groundwater at the site has shown that most of the mercury is bonded with humic and fulvic acids (HFA) in colloidal form. The Hg-HFA colloids can be completely removed from the groundwater with ferric chloride treatment under optimized process conditions to form ferric sludge (FS), which is rendered non-leachable by standard TCLP (Toxicity Characteristic Leaching Procedure) test. The effluent discharged from a clarifier has achieved mercury levels of mercury adsorption characteristics of FS show it has low mercury leachability by TCLP, and great mercury adsorption capability. This feature is the basis for the application of FS to immobilization of leachable Hg-contaminants in solid wastes. Full-scale stabilization tests of Hg-contaminated soil have been carried out, and the time-based stability of the treated soil has been monitored by TCLP over a period of 60 days. All the results have shown a small variation in TCLP mercury levels within a range of 10-40 microg l(-1). Based on these results and with the approval of the B.C. Ministry of the Environment, 1850 tons of Hg-contaminated soils and 260 tons of Hg-contaminated concrete fines have been treated, stabilized with FS, and disposed in a non-hazardous waste disposal site. PMID:14733397

  5. Managing hyperphosphatemia in patients with chronic kidney disease on dialysis with ferric citrate: latest evidence and clinical usefulness.

    Science.gov (United States)

    Yagil, Yoram; Fadem, Stephen Z; Kant, Kotagal S; Bhatt, Udayan; Sika, Mohammed; Lewis, Julia B; Negoi, Dana

    2015-09-01

    Ferric citrate is a novel phosphate binder that allows the simultaneous treatment of hyperphosphatemia and iron deficiency in patients being treated for end-stage renal disease with hemodialysis (HD). Multiple clinical trials in HD patients have uniformly and consistently demonstrated the efficacy of the drug in controlling hyperphosphatemia with a good safety profile, leading the US Food and Drug Administration in 2014 to approve its use for that indication. A concurrent beneficial effect, while using ferric citrate as a phosphate binder, is its salutary effect in HD patients with iron deficiency being treated with an erythropoietin-stimulating agent (ESA) in restoring iron that becomes available for reversing chronic kidney disease (CKD)-related anemia. Ferric citrate has also been shown in several studies to diminish the need for intravenous iron treatment and to reduce the requirement for ESA. Ferric citrate is thus a preferred phosphate binder that helps resolve CKD-related mineral bone disease and iron-deficiency anemia. PMID:26336594

  6. A bipolar membrane combined with ferric iron reduction as an efficient cathode system in microbial fuel cells

    NARCIS (Netherlands)

    Heijne, ter A.; Hamelers, H.V.M.; Wilde, de V.; Rozendal, R.A.; Buisman, C.J.N.

    2006-01-01

    There is a need for alternative catalysts for oxygen reduction in the cathodic compartment of a microbial fuel cell (MFC). In this study, we show that a bipolar membrane combined with ferric iron reduction on a graphite electrode is an efficient cathode system in MFCs. A flat plate MFC with graphite

  7. Oxidation of sulphide minerals--I: determination of ferrous and ferric iron in samples of pyrrhotite, pyrite and chalcopyrite.

    Science.gov (United States)

    Steger, H F

    1977-04-01

    A method has been developed for determining small amounts of both ferrous and ferric iron in oxidized samples of pyrrhotite, pyrite and chalcopyrite. The oxidized iron is selectively dissolved in 10M phosphoric acid under reflux and can be determined with the accuracy generally accepted in chemical phase analysis. PMID:18962075

  8. Comparative Evaluation of Aluminum Sulfate and Ferric Sulfate-Induced Coagulations as Pretreatment of Microfiltration for Treatment of Surface Water

    Science.gov (United States)

    Song, Yali; Dong, Bingzhi; Gao, Naiyun; Deng, Yang

    2015-01-01

    Two coagulants, aluminum sulfate and ferric chloride, were tested to reduce natural organic matter (NOM) as a pretreatment prior to polyvinylidene fluoride (PVDF) microfiltration (MF) membranes for potable water treatment. The results showed that the two coagulants exhibited different treatment performance in NOM removal. Molecular weight (MW) distributions of NOM in the tested surface raw water were concentrated at 3–5 kDa and approximately 0.2 kDa. Regardless of the coagulant species and dosages, the removal of 0.2 kDa NOM molecules was limited. In contrast, NOM at 3–5 kDa were readily removed with increasing coagulant dosages. In particular, aluminum sulfate favorably removed NOM near 5 kDa, whereas ferric chloride tended to reduce 3 kDa organic substances. Although aluminum sulfate and ferric chloride could improve the flux of the ensuing MF treatment, the optimal coagulant dosages to achieve effective pretreatment were different: 2–30 mg/L for aluminum sulfate and >15 mg/L for ferric chloride. The scanning electron microscope (SEM) image of the membrane-filtered coagulated raw water showed that coagulation efficiency dramatically affected membrane flux and that good coagulation properties can reduce membrane fouling. PMID:26075726

  9. Comparative Evaluation of Aluminum Sulfate and Ferric Sulfate-Induced Coagulations as Pretreatment of Microfiltration for Treatment of Surface Water

    Directory of Open Access Journals (Sweden)

    Yali Song

    2015-06-01

    Full Text Available Two coagulants, aluminum sulfate and ferric chloride, were tested to reduce natural organic matter (NOM as a pretreatment prior to polyvinylidene fluoride (PVDF microfiltration (MF membranes for potable water treatment. The results showed that the two coagulants exhibited different treatment performance in NOM removal. Molecular weight (MW distributions of NOM in the tested surface raw water were concentrated at 3–5 kDa and approximately 0.2 kDa. Regardless of the coagulant species and dosages, the removal of 0.2 kDa NOM molecules was limited. In contrast, NOM at 3–5 kDa were readily removed with increasing coagulant dosages. In particular, aluminum sulfate favorably removed NOM near 5 kDa, whereas ferric chloride tended to reduce 3 kDa organic substances. Although aluminum sulfate and ferric chloride could improve the flux of the ensuing MF treatment, the optimal coagulant dosages to achieve effective pretreatment were different: 2–30 mg/L for aluminum sulfate and >15 mg/L for ferric chloride. The scanning electron microscope (SEM image of the membrane-filtered coagulated raw water showed that coagulation efficiency dramatically affected membrane flux and that good coagulation properties can reduce membrane fouling.

  10. Bacterial oxidation activity in heap leaching

    Institute of Scientific and Technical Information of China (English)

    柳建设; 夏海波; 王兆慧; 胡岳华

    2004-01-01

    Bioleaching of sulfide minerals by bacteria, mainly Thiobacillus ferrooxidans (T. f. ) and Thiobacillus thiooxidans, plays an important role in hydrometallurgy because of its economic and environmental attractions. The surveys of production process and the bacterial oxidation activity in the heap bioleaching were investigated. The results show that pH value is high, bacteria biomass and ferric concentration are low, generation time (above 7.13 h)is long in leachate, and less bacteria are adsorbed on the ores. The bacteria in the leachate exposing on the surface and connecting with mineral, have much faster oxidation rate of Fe( Ⅱ ) and shorter generation time, compared with those which are in the reservoir for a long time. There is diversity for oxidation activity of Fe( Ⅱ ), while there is no diversity for oxidation of sulfur. So it is advisable to add sulfuric acid to degrade pH value to 2.0, add nutrients and shorten recycling time of leachate, so as to enhance bacteria concentration of leachate and the leaching efficiency.

  11. Compatibility relationships in the U-Fe-O(-H) system at 4000C: the implications of the ferric-ferrous buffer for the immobilization of uranium and transuranic elements

    International Nuclear Information System (INIS)

    The current strategy for the immobilization of nuclear wastes is based upon a system of multiply redundant barriers for which geological containment is the final barrier to the migration of radionuclides in the biosphere. The ability of the repository host rock to buffer the oxygen fugacity of the pore waters is a critical concern for the evaluation of the far-field migration of selected elements; notably Tc, U and TRU elements. The buffer capacity of all proposed host rocks, with the exception of salt, is based upon the presence of both ferric and ferrous iron in the host rock phases. The system U-Fe-O(-H) was selected for study because of its significance on the role of Fe in controlling the oxidation state of the U. It has been established that the Fe2+/Fe3+ couple is the controlling factor in limiting the uranium oxidation to the U4+ state. The results from this experimental study at 4000C (the maximum worse case temperature for a repository) verified the existence of the compatibility triangles between hematite and UO200 and magnetite and between U4O9 and UO200 and hematite. These data indicate that in the presence both ferric and ferrous ions, the form of the uranium dioxide is retained as stoichiometric UO200 and not as an intermediate member of the UO/sub 2+x/ solid solution series or other higher oxide

  12. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    -vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial......Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate...... filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...

  13. Demonstrating Bacterial Flagella.

    Science.gov (United States)

    Porter, John R.; And Others

    1992-01-01

    Describes an effective laboratory method for demonstrating bacterial flagella that utilizes the Proteus mirabilis organism and a special harvesting technique. Includes safety considerations for the laboratory exercise. (MDH)

  14. Selective removal of arsenic and monovalent ions from brackish water reverse osmosis concentrate.

    Science.gov (United States)

    Xu, Pei; Capito, Marissa; Cath, Tzahi Y

    2013-09-15

    Concentrate disposal and management is a considerable challenge for the implementation of desalination technologies, especially for inland applications where concentrate disposal options are limited. This study has focused on selective removal of arsenic and monovalent ions from brackish groundwater reverse osmosis (RO) concentrate for beneficial use and safe environmental disposal using in situ and pre-formed hydrous ferric oxides/hydroxides adsorption, and electrodialysis (ED) with monovalent permselective membranes. Coagulation with ferric salts is highly efficient at removing arsenic from RO concentrate to meet a drinking water standard of 10 μg/L. The chemical demand for ferric chloride however is much lower than ferric sulfate as coagulant. An alternative method using ferric sludge from surface water treatment plant is demonstrated as an efficient adsorbent to remove arsenic from RO concentrate, providing a promising low cost, "waste treat waste" approach. The monovalent permselective anion exchange membranes exhibit high selectivity in removing monovalent anions over di- and multi-valent anions. The transport of sulfate and phosphate through the anion exchange membranes was negligible over a broad range of electrical current density. However, the transport of divalent cations such as calcium and magnesium increases through monovalent permselective cation exchange membranes with increasing current density. Higher overall salt concentration reduction is achieved around limiting current density while higher normalized salt removal rate in terms of mass of salt per membrane area and applied energy is attained at lower current density because the energy unitization efficiency decreases at higher current density. PMID:23892312

  15. Effect of dissolved ozone or ferric ions on photodegradation of thiacloprid in presence of different TiO2 catalysts

    Czech Academy of Sciences Publication Activity Database

    Černigoj, U.; Štangar, U. L.; Jirkovský, Jaromír

    2010-01-01

    Roč. 177, 1-3 (2010), s. 399-406. ISSN 0304-3894 Institutional research plan: CEZ:AV0Z40400503 Keywords : neonicotionoid pesticides * photocatalysis * ozonation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.723, year: 2010

  16. Removal of the blue 1 dye of aqueous solutions using ferric zeolite; Remocion del colorante azul 1 de soluciones acuosas utilizando zeolita ferrica

    Energy Technology Data Exchange (ETDEWEB)

    Pinedo H, S. Y.

    2010-07-01

    amount of adsorbent from 10 to 200 mg of adsorbent and 10 ml of solution. Finally there was a column sorption test, obtaining the curve os load vs time of contact, and important design parameters such as the rupture time, it was at 100 minutes, with an initial concentration of 5 mg/L taking final concentration breakpoint of 0.4 mg/L, the results were evaluated with the Thomas model. The results of this work can conclude that it is possible to extend the scope of natural zeolites as adsorbents for the removal of organic pollutants in wastewater, by changing its outer surface with ferric chloride, without a significant effect on their ion exchange properties. (Author)

  17. Shuffling bacterial metabolomes

    OpenAIRE

    Thomason, Brendan; Read, Timothy D.

    2006-01-01

    Horizontal gene transfer (HGT) has a far more significant role than gene duplication in bacterial evolution. This has recently been illustrated by work demonstrating the importance of HGT in the emergence of bacterial metabolic networks, with horizontally acquired genes being placed in peripheral pathways at the outer branches of the networks.

  18. Vimentin in Bacterial Infections.

    Science.gov (United States)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection. PMID:27096872

  19. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that ...... become valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  20. Vimentin in Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Tim N. Mak

    2016-04-01

    Full Text Available Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs. IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection.

  1. Comparative stability of the bioresorbable ferric crosslinked hyaluronic acid adhesion prevention solutions.

    Science.gov (United States)

    Luu, Hoan-My Do; Chen, Angela; Isayeva, Irada S

    2013-08-01

    The Intergel® ferric crosslinked hyaluronate (FeHA) adhesion prevention solution (APS) (FDA) is associated with serious post-operative complications (Henley, http://www.lawyersandsettlements.com/features/gynecare-intergel/intergel-timeline.html, 2007; FDA, 2003; Roman et al., Fertil Steril 2005, 83 Suppl 1:1113-1118; Tang et al., Ann Surg 2006;243(4):449-455; Wiseman, Fertil Steril 2006;86(3):771; Wiseman, Fertil Steril 2006;85(4):e7). This prompted us to examine the in situ stability of crosslinked HA materials to hyaluronidase lyase degradation. Variables such as ferric ionic crosslink density, HA concentration, gel geometry, and molecular weight (MW) of HA polymer were studied. Various formulations of the crosslinked "in house" [Isayeva et al., J Biomed Mater Res: Part B - Appl Biomater 2010, 95B (1):9-18] FeHA (0.5%, w/v; 30, 50, 90% crosslinked), the Intergel® FeHA (0.5%, w/v; 90%), and the non-crosslinked HA (0.05-0.5%, w/v) were degraded at a fixed activity of hyaluronidase lyase from Streptomyces hyalurolyticus (Hyase) at 37°C over time according to the method [Payan et al., J Chrom B: Biomed Sci Appl 1991;566(1):9-18]. Under our conditions, the data show that the crosslink density affects degradation the most, followed by HA concentration and then gel geometry. We found that MW has no effect. Our results are one possible explanation of the observations that the Intergel® FeHA APS (0.5%, w/v; 90%) material persisted an order of magnitude longer than expected [t1/2 = 500 hrs vs. t1/2 = 50 hrs (FDA; Johns et al., Fertil Steril 1997;68(1):37-42)]. These data also demonstrate the sensitivity of the in vitro hyaluronidase assay to predict the in situ stability of crosslinked HA medical products as previously reported [Sall et al., Polym Degrad Stabil 2007;92(5):915-919]. PMID:23559362

  2. Application of granular ferric hydroxides for removal elevated concentrations of arsenic from mine waters

    Science.gov (United States)

    Szlachta, Małgorzata; Włodarczyk, Paweł; Wójtowicz, Patryk

    2015-04-01

    Arsenic is naturally occurring element in the environment. Over three hundred minerals are known to contain some form of arsenic and among them arsenopyrite is the most common one. Arsenic-bearing minerals are frequently associated with ores containing mined metals such as copper, tin, nickel, lead, uranium, zinc, cobalt, platinum and gold. In the aquatic environment arsenic is typically present in inorganic forms, mainly in two oxidation states (+5, +3). As(III) is dominant in more reduced conditions, whereas As(V) is mostly present in an oxidizing environment. However, due to certain human activities the elevated arsenic levels in aquatic ecosystems are arising to a serious environmental problem. High arsenic concentrations found in surface and groundwaters, in some regions originate from mining activities and ore processing. Therefore, the major concern of mining industry is to maintain a good quality of effluents discharged in large volumes. This requires constant monitoring of effluents quality that guarantee the efficient protection of the receiving waters and reacting to possible negative impact of contamination on local communities. A number of proven technologies are available for arsenic removal from waters and wastewaters. In the presented work special attention is given to the adsorption method as a technically feasible, commonly applied and effective technique for the treatment of arsenic rich mine effluents. It is know that arsenic has a strong affinity towards iron rich materials. Thus, in this study the granular ferric hydroxides (CFH 12, provided by Kemira Oyj, Finland) was applied to remove As(III) and As(V) from aqueous solutions. The batch adsorption experiments were carried out to assess the efficiency of the tested Fe-based material under various operating parameters, including composition of treated water, solution pH and temperature. The results obtained from the fixed bed adsorption tests demonstrated the benefits of applying granular

  3. Optimizing iron delivery in the management of anemia: patient considerations and the role of ferric carboxymaltose

    Directory of Open Access Journals (Sweden)

    Toblli JE

    2014-12-01

    Full Text Available Jorge Eduardo Toblli, Margarita Angerosa Nephrology Section, Department of Internal Medicine, Hospital Alemán, School of Medicine, University of Buenos Aires, Argentina Abstract: With the challenge of optimizing iron delivery, new intravenous (iv iron–carbohydrate complexes have been developed in the last few years. A good example of these new compounds is ferric carboxymaltose (FCM, which has recently been approved by the US Food and Drug Administration for the treatment of iron deficiency anemia in adult patients who are intolerant to oral iron or present an unsatisfactory response to oral iron, and in adult patients with non-dialysis-dependent chronic kidney disease (NDD-CKD. FCM is a robust and stable complex similar to ferritin, which minimizes the release of labile iron during administration, allowing higher doses to be administered in a single application and with a favorable cost-effective rate. Cumulative information from randomized, controlled, multicenter trials on a diverse range of indications, including patients with chronic heart failure, postpartum anemia/abnormal uterine bleeding, inflammatory bowel disease, NDD-CKD, and those undergoing hemodialysis, supports the efficacy of FCM for iron replacement in patients with iron deficiency and iron-deficiency anemia. Furthermore, as FCM is a dextran-free iron–carbohydrate complex (which has a very low risk for hypersensitivity reactions with a small proportion of the reported adverse effects in a large number of subjects who received FCM, it may be considered a safe drug. Therefore, FCM appears as an interesting option to apply high doses of iron as a single infusion in a few minutes in order to obtain the quick replacement of iron stores. The present review on FCM summarizes diverse aspects such as pharmacology characteristics and analyzes trials on the efficacy/safety of FCM versus oral iron and different iv iron compounds in multiple clinical scenarios. Additionally, the

  4. Preparation and evaluation of holmium-166 ferric hydroxide macroaggregates for radiation synovectomy

    International Nuclear Information System (INIS)

    Aim: The treatment of rheumatoid arthritis using radiopharmaceuticals is an important therapeutic approach. It has been used for more than 40 years to alleviate the pain and swelling of rheumatoid arthritis. Radionuclides such as 153Sm, 90Y and 166Ho were the most interesting ones, because of their short half-lives, low energy beta particle emitters and little gamma ray emission. Ferric hydroxide macroaggregates (FHMA) labeled with 166Ho were studied as a radiation synovectomy agent. Materials and Methods: 166Ho was produced at RA3 reactor of Centro Atomico Ezeiza, by irradiation of natural holmium (100% of 165Ho; 'Spectrographically Standardized'), via the n,γ nuclear reaction. In order to produce labeled particles, a coprecipitation technique of holmium hydroxide Ho(OH)3 and ferric hydroxide Fe(OH)3 was used. The 166Ho-FHMA particles were resuspended in saline and the suspension was sterilized by autoclaving. Pyrogen and sterility tests were performed following known procedures of Pharmacopoeia. Radionuclidic purity control was performed with an high purity germanium high-resolution gamma spectrometry system. Particles in vivo behavior was investigated following intra-articular injection into knees of Wistar rats, normal rabbits and rabbits with antigen induced arthritis (AIA). Gamma camera images of the whole body were analyzed up to 4 and 24 h post injection period. Results: Irradiated samples were counted after 1, 2, 5 and 15 days of irradiation to determine whether other longer lived radionuclides were produced. The only expected isotopic impurity, 166mHo, was no detectable through the gamma spectrometry system. Obtainment efficiency of macroaggregates was greater than 90%. Particle size was determined by optical microscopy and selective filtration (1,2 - 100 μm). At least 90% of FHMA particles were in the range of 20-30 μm. In vitro studies showed minimal (166Ho-FHMA remained into the knee up to 72 h post-injection. A 25% of activity leakage from the knee

  5. The Enzyme-mimic Activity of Ferric Nano-Core Residing in Ferritin and Its Biosensing Applications

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Zhiwen; Wu, Hong J.; Zhang, Youyu; Li, Zhaohui; Lin, Yuehe

    2011-11-15

    Ferritins are nano-scale globular protein cages encapsulating a ferric core. They widely exist in animals, plants, and microbes, playing indispensable roles in iron homeostasis. Interestingly, our study clearly demonstrates that ferritin has an enzyme-mimic activity derived from its ferric nano-core, but not the protein cage. Further study revealed that the mimic-enzyme activity of ferritin is more thermally stable and pH-tolerant compared with horseradish peroxidase. Considering the abundance of ferritin in numerous organisms, this finding may indicate a new role of ferritin in antioxidant and detoxification metabolisms. In addition, as a natural protein-caged nanoparticle with an enzyme-mimic activity, ferritin is readily conjugated with biomolecules to construct nano-biosensors, thus holds promising potential for facile and biocompatible labeling for sensitive and robust bioassays in biomedical applications.

  6. CIPK23 is involved in iron acquisition of Arabidopsis by affecting ferric chelate reductase activity.

    Science.gov (United States)

    Tian, Qiuying; Zhang, Xinxin; Yang, An; Wang, Tianzuo; Zhang, Wen-Hao

    2016-05-01

    Iron deficiency is one of the major limiting factors affecting quality and production of crops in calcareous soils. Numerous signaling molecules and transcription factors have been demonstrated to play a regulatory role in adaptation of plants to iron deficiency. However, the mechanisms underlying the iron deficiency-induced physiological processes remain to be fully dissected. Here, we demonstrated that the protein kinase CIPK23 was involved in iron acquisition. Lesion of CIPK23 rendered Arabidopsis mutants hypersensitive to iron deficiency, as evidenced by stronger chlorosis in young leaves and lower iron concentration than wild-type plants under iron-deficient conditions by down-regulating ferric chelate reductase activity. We found that iron deficiency evoked an increase in cytosolic Ca(2+) concentration and the elevated Ca(2+) would bind to CBL1/CBL9, leading to activation of CIPK23. These novel findings highlight the involvement of calcium-dependent CBL-CIPK23 complexes in the regulation of iron acquisition. Moreover, mutation of CIPK23 led to changes in contents of mineral elements, suggesting that CBL-CIPK23 complexes could be as "nutritional sensors" to sense and regulate the mineral homeostasis in Arabisopsis. PMID:26993237

  7. Development of Leptospirillum ferriphilum dominated consortium for ferric iron regeneration and metal bioleaching under extreme stresses.

    Science.gov (United States)

    Patel, Bhargav C; Tipre, Devayani R; Dave, Shailesh R

    2012-08-01

    Activated iron oxidizing consortium SR-BH-L enriched from Rajpardi lignite mine soil sample gave iron oxidation rate 1954 mg/L/h. Developed novel polystress resistant consortium oxidized ferrous iron under 11cP viscosity, 7.47 M ionic strength, 2.3 pH and g/L of 0.50 cadmium, 3.75 copper, 0.20 lead, 92.00 zinc, 6.4 sodium, 5.5 chloride, 154 sulphate and 393.8 TDS. The developed consortium showed 78.0% and 70.0% copper and zinc extraction from polymetallic bulk concentrate in monophasic bioleaching process. The bioregenerated ferric by the consortium in leachate showed 80.81% and 54.0% copper and zinc leaching in only 30 and 90 min. The DGGE analysis indicated the presence of 11 OTUs in the consortium. 16S rRNA gene sequence (JN797729) of the dominant band on DGGE shared >99% similarity with Leptospirillum ferriphilum. RE digestion analysis of the total 16S rRNA gene also illustrated the dominance of L. ferriphilum in the consortium. PMID:22717567

  8. Ferric reducing antioxidant power of essential oils extracted from Eucalyptus and Curcuma species

    Institute of Scientific and Technical Information of China (English)

    Durre Shahwar; Muhammad Asam Raza; Sana Bukhari; Gulshan Bukhari

    2012-01-01

    Objective: Eucalyptus and Curcuma species are well reputed for their traditional medicinal uses in south east Asia, therefore, the present study was designed to determine reducing potential of their essential oils. Method: Essential oils of the selected medicinal species Eucalyptussideroxylon, E. teriticornis, E. citriodora, Curcuma longa and C. aromatic were extracted using hydro distillation method, separated with diethyl ether and dried over anhydrous sodium sulphate. Column chromatography of Curcuma aromatica was carried out and six fractions were collected using gradient solvent system of n-hexane-ethyl acetate. Ferric reducing antioxidant power (FRAP) of oils were evaluated using standard protocol and results were expressed in μM equivalent to FeSO4.7H2O. Results: The essential oil of Eucalyptus sideroxylon was found to possess highest reducing potential among the Eucalyptus species. Curcuma longa essential oil showed most significant reducing potential with 138.4±1.1 FRAP equivalents. Conclusions:It was concluded that the all essential oil and the column fractions of C. aromatica possess significant reducing capacity ranged from 95.8±1.0 to 152.4±1.4 μM in a dose dependent manner.

  9. A ferric-cyanide-bridged one-dimensional dirhodium complex with (18-crown-6)potassium cations.

    Science.gov (United States)

    Kim, Y; Kim, S J; Nam, W

    2001-03-01

    The crystal structure of the title compound, catena-poly[bis[aqua(18-crown-6)potassium] diaqua(18-crown-6)potassium [[tetra-mu-benzoato-2:3 kappa(8)O:O'-mu-cyano-1:2 kappa(2)C:N-tetracyano-1 kappa C-irondirhodium(Rh-Rh)]-mu-cyano-1 kappa C:3' kappa N] octahydrate], [K(18-crown-6)(H(2)O)](2)[K(18-crown-6)(H(2)O)(2)][FeRh(2)(C(7)H(5)O(2))(4)(CN)(6)] x 8H(2)O, where (18-crown-6) is 1,4,7,10,13,16-hexaoxacyclooctadecane (C(12)H(24)O(6)), has been determined. Ferric cyanides connect the dirhodium units to form a one-dimensional chain compound. [K(18-crown-6-ether)(H(2)O)(2)] cations (with inversion symmetry) and [K(18-crown-6-ether)(H(2)O)] cations (in general positions) are located between the chains. PMID:11250572

  10. [Characteristics of orthophosphate adsorption on ferric-alum residuals (FARs) from drinking water treatment plant].

    Science.gov (United States)

    Wang, Chang-Hui; Pei, Yuan-Sheng

    2011-08-01

    Batch tests have been used to investigate the characteristics of orthophosphate adsorption on ferric-alum residuals (FARs) from drinking water treatment plant. ICP, SEM and XRD analyses confirm that the FARs enriched in Fe and Al elements and presented amorphism structure. Orthophosphate sorption by the FARs can be described by the pseudo-second-order kinetics equation. Fine adsorption effects of the FARs were found under lower pH values, particularly a 40.13% drop of the adsorptive capacity from pH 4.6 to pH 7.6. The FARs with grain sizes of 0.6-0.9 mm had the highest adsorption capacity of orthophosphate. Experimental data could be better fitted by the isotherm models of Langmuir (R2 = 0.9736) and Freundlich (R2 = 0.9916). The maximal adsorptive capacity reached 45.45 mg x g(-1) estimated from Langmuir isotherm model. Compared with other natural and industrial materials, FARs has relatively higher adsorption capacity. Under similar testing conditions, it was found that only about 10% orthophosphate could be desorbed from the FARs. Further study demonstrated that the mean energy of orthophosphate sorption on the FARs was 13.36 kJ x mol(-1) and the deltaH0 > 0, deltaS0 > 0 and deltaG0 wastewater and surface water. PMID:22619965

  11. Indirect spectrophotometric determination of arbutin, whitening agent through oxidation by periodate and complexation with ferric chloride

    Science.gov (United States)

    Barsoom, B. N.; Abdelsamad, A. M. E.; Adib, N. M.

    2006-07-01

    A simple and accurate spectrophotometric method for the determination of arbutin (glycosylated hydroquinone) is described. It is based on the oxidation of arbutin by periodate in presence of iodate. Excess periodate causes liberation of iodine at pH 8.0. The unreacted periodate is determined by measurement of the liberated iodine spectrophotometrically in the wavelength range (300-500 nm). A calibration curve was constructed for more accurate results and the correlation coefficient of linear regression analysis was -0.9778. The precision of this method was better than 6.17% R.S.D. ( n = 3). Regression analysis of Bear-Lambert plot shows good correlation in the concentration range 25-125 ug/ml. The identification limit was determined to be 25 ug/ml a detailed study of the reaction conditions was carried out, including effect of changing pH, time, temperature and volume of periodate. Analyzing pure and authentic samples containing arbutin tested the validity of the proposed method which has an average percent recovery of 100.86%. An alternative method is also proposed which involves a complexation reaction between arbutin and ferric chloride solution. The produced complex which is yellowish-green in color was determined spectophotometrically.

  12. Amelioration of ferric nitrilotriacetate-induced hepatotoxicity in Wistar rats by diallylsulfide.

    Science.gov (United States)

    Ansar, S; Iqbal, M

    2016-03-01

    Garlic contains diallylsulfide (DAS) and other structurally related compounds that are widely believed to be active agents in preventing cancer. This study shows the effect of DAS (a phenolic antioxidant used in foods, cosmetics, and pharmaceutical products) on ferric nitrilotriacetate (Fe-NTA)-induced hepatotoxicity in rats. Male albino rats of Wistar strain weighing 125-150 g were given a single dose of Fe-NTA (9 mg kg(-1) body weight, intraperitoneally) after 1 week of treatment with 100 and 200 mg kg(-1) DAS in corn oil respectively administered through the gavage. Fe-NTA administration led to 2.5-fold increase in the values of both alanine transaminase and aspartate aminotransferase, respectively, and 3.2-fold increase in the activity of lactate dehydrogenase, microsomal lipid peroxidation to approximately 2.0-fold compared to saline-treated control. The activities of glutathione (GSH) and other antioxidant enzymes decreased to a range of 2.2-2.5-fold. These changes were reversed significantly (p rats. PMID:25904316

  13. Adsorption of phosphonate antiscalant from reverse osmosis membrane concentrate onto granular ferric hydroxide.

    Science.gov (United States)

    Boels, Luciaan; Keesman, Karel J; Witkamp, Geert-Jan

    2012-09-01

    Adsorptive removal of antiscalants offers a promising way to improve current reverse osmosis (RO) concentrate treatment processes and enables the reuse of the antiscalant in the RO desalination process. This work investigates the adsorption and desorption of the phosphonate antiscalant nitrilotris(methylenephosphonic acid) (NTMP) from RO membrane concentrate onto granular ferric hydroxide (GFH), a material that consists predominantly of akaganéite. The kinetics of the adsorption of NTMP onto GFH was predicted fairly well with two models that consider either combined film-pore or combined film-surface diffusion as the main mechanism for mass transport. It is also demonstrated that NTMP is preferentially adsorbed over sulfate by GFH at pH 7.85. The presence of calcium causes a transformation in the equilibrium adsorption isotherm from a Langmuir type to a Freundlich type with much higher adsorption capacities. Furthermore, calcium also increases the rate of adsorption substantially. GFH is reusable after regeneration with sodium hydroxide solution, indicating that NTMP can be potentially recovered from the RO concentrate. This work shows that GFH is a promising adsorbent for the removal and recovery of NTMP antiscalant from RO membrane concentrates. PMID:22873428

  14. Potentially Life-Threatening Phosphate Diabetes Induced by Ferric Carboxymaltose Injection: A Case Report and Review of the Literature

    OpenAIRE

    Xavier Vandemergel; Frédéric Vandergheynst

    2014-01-01

    We report the case of a 45-year-old female patient who developed phosphate diabetes after administration of ferric carboxymaltose. Ten days after the second dose, she complained of intense fatigue and blood analysis showed a phosphate plasma level of 0.93 mg/dL with phosphate excretion rate of 23%. She received phosphate supplementation which resulted in phosphate clearance improvement which persisted for two months. We reviewed other cases described in the literature and would draw attention...

  15. Decomposition of a Mixed-Valence [2Fe-2S] Cluster to Linear Tetra-Ferric and Ferrous Clusters

    Science.gov (United States)

    Saouma, Caroline T.; Kaminsky, Werner; Mayer, James M.

    2012-01-01

    Despite the ease of preparing di-ferric [2Fe-2S] clusters, preparing stable mixed-valence analogues remains a challenge, as these clusters have limited thermal stability. Herein we identify two decomposition products of the mixed-valence thiosalicylate-ligated [2Fe-2S] cluster, [Fe2S2(SArCOO)2]3− ((SArCOO)2− = thiosalicylate). PMID:23976815

  16. Managing hyperphosphatemia in patients with chronic kidney disease on dialysis with ferric citrate: latest evidence and clinical usefulness

    OpenAIRE

    Yagil, Yoram; Fadem, Stephen Z.; Kant, Kotagal S.; Bhatt, Udayan; Sika, Mohammed; Lewis, Julia B.; Negoi, Dana

    2015-01-01

    Ferric citrate is a novel phosphate binder that allows the simultaneous treatment of hyperphosphatemia and iron deficiency in patients being treated for end-stage renal disease with hemodialysis (HD). Multiple clinical trials in HD patients have uniformly and consistently demonstrated the efficacy of the drug in controlling hyperphosphatemia with a good safety profile, leading the US Food and Drug Administration in 2014 to approve its use for that indication. A concurrent beneficial effect, w...

  17. Fast Release of Sulfosalicylic Acid from Polymer Implants Consisting of Regenerated Cellulose/γ-Ferric Oxide/Polypyrrole

    OpenAIRE

    Nargis A. Chowdhury; John Robertson; Ahmed Al-Jumaily; Ramos, Maximiano V.

    2014-01-01

    This work presents a comparative study on the rate of drug release from implantable matrices induced by electric and magnetic fields separately for better biomedical applications. The matrices were prepared by coating γ-ferric oxide dispersed regenerated cellulose film by polypyrrole doped with sulfosalicylic acid as an anti-inflammatory drug. The drug release mechanisms were studied under both the electric and the magnetic fields separately in an acetate buffer solution with pH 5.5 and tempe...

  18. Effectiveness and safety of ferric carboxymaltose treatment in children and adolescents with inflammatory bowel disease and other gastrointestinal diseases

    OpenAIRE

    Laass, Martin W.; Straub, Simon; Chainey, Suki; Virgin, Garth; Cushway, Timothy

    2014-01-01

    Background The treatment of iron deficiency anemia in children with inflammatory bowel disease is a particular challenge and often insufficient. Absorption of orally given iron may be impaired by intestinal inflammation and treatment with oral iron may aggravate intestinal inflammation. This retrospective study is the first to describe the use of intravenous ferric carboxymaltose (FCM) in the pediatric setting. Methods All subjects who had received at least one dose of FCM intravenously in th...

  19. Cost-effectiveness analysis of ferric carboxymaltose in iron-deficient patients with chronic heart failure in Sweden.

    OpenAIRE

    Hofmarcher, Thomas; Borg, Sixten

    2015-01-01

    OBJECTIVE: Iron deficiency is a common but treatable comorbidity in chronic heart failure (CHF) that is associated with impaired health-related quality-of-life (HRQoL). This study evaluates the cost-effectiveness of the intravenous iron preparation ferric carboxymaltose (FCM) for the treatment of iron deficiency in CHF from a Swedish healthcare perspective. METHODS: A cost-effectiveness analysis with a time horizon of 24 weeks was performed to compare FCM treatment with p...

  20. EVALUATION OF FERRIC CHLORIDE AND ALUM EFFICIENCIES IN ENHANCED COAGULATION FOR TOC REMOVAL AND RELATED RESIDUAL METAL CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    A. Mesdaghinia, M. T. Rafiee, F. Vaezi and A. H. Mahvi

    2005-07-01

    Full Text Available Although the removal of colloidal particles continues to be an important reason for using coagulation, a newer objective, the removal of natural organic matter (NOM to reduce the formation of disinfection by-products (DBPs, is growing in importance. Enhanced coagulation is thus introduced to most water utilities treating surface water. Bench-scale experiments were conducted to compare the effectiveness of alum and ferric chloride in removing DBPs precursors from eight synthetic water samples, each representing a different element of the USEPA’s 3×3 enhanced coagulation matrix. The effect of enhanced coagulation on the residual metal (aluminum/iron concentration in the treated water was assessed as well. The removal of total organic carbon (TOC was dependent on the coagulant type and was enhanced with increasing coagulant dose, but the latter had no further considerable effect in case of increasing to high levels. For all the treated samples coagulation with ferric chloride proved to be more effective than alum at similar doses and the mean values of treatment efficiencies were 51% and 32% for ferric chloride and alum, respectively. Ferric chloride was therefore considered the better chemical for enhancing the coagulation process. Besides, due to less production of sludge by this coagulant, it would be predicted that treatment plants would be confronted to fewer problems with respect to final sludge disposal. Measurements of residual metal in treated water indicated that iron and aluminum concentrations had been increased as expected but the quality of water concerning the residual metal deteriorated much more in cases of under-dosing. Despite expecting high residual Al and Fe concentrations under enhanced coagulation, metal concentrations were frequently remained low and were not increased appreciably.

  1. The Bacillus subtilis EfeUOB transporter is essential for high-affinity acquisition of ferrous and ferric iron.

    Science.gov (United States)

    Miethke, Marcus; Monteferrante, Carmine G; Marahiel, Mohamed A; van Dijl, Jan Maarten

    2013-10-01

    Efficient uptake of iron is of critical importance for growth and viability of microbial cells. Nevertheless, several mechanisms for iron uptake are not yet clearly defined. Here we report that the widely conserved transporter EfeUOB employs an unprecedented dual-mode mechanism for acquisition of ferrous (Fe[II]) and ferric (Fe[III]) iron in the bacterium Bacillus subtilis. We show that the binding protein EfeO and the permease EfeU form a minimal complex for ferric iron uptake. The third component EfeB is a hemoprotein that oxidizes ferrous iron to ferric iron for uptake by EfeUO. Accordingly, EfeB promotes growth under microaerobic conditions where ferrous iron is more abundant. Notably, EfeB also fulfills a vital role in cell envelope stress protection by eliminating reactive oxygen species that accumulate in the presence of ferrous iron. In conclusion, the EfeUOB system contributes to the high-affinity uptake of iron that is available in two different oxidation states. PMID:23764491

  2. Corrosion resistance of electrodeposited RE-Ni-W-P-SiC-PTFE composite coating in phosphoric and ferric chloride

    Institute of Scientific and Technical Information of China (English)

    XU Rui-dong; GUO Zhong-cheng; PAN Jun-yi

    2006-01-01

    Corrosion rate and anode polarization curves of electrodeposited RE-Ni-W-P-SiC-PTFE composite coating in various concentrations of phosphoric and ferric chloride were researched. The results show that corrosion rate of the composite coatings increases with the increasing concentrations of phosphoric and ferric chloride, and reaches the maximum value when phosphoric concentration is 40% and ferric chloride concentration is 20% (mass fraction, the same below if not mentioned). Anode polarization curves of the composite coatings show that anode polarization current density of the composite coatings heat-treated at 200 ℃ or 500 ℃ is lower than that of other coatings heat-treated at 300 ℃ or 400 ℃, which displays that the composite coatings heat-treated at 200 ℃ or 500 ℃ have better corrosion resistance. Besides, corrosion resistance of the composite coating heat-treated at 500 ℃ is better than that as deposited and RE-Ni-W-P-SiC composite coating heat-treated at 400 ℃, and is also better than that of 316L stainless steel.

  3. Rationale and study design of a three-period, 58-week trial of ferric citrate as a phosphate binder in patients with ESRD on dialysis.

    Science.gov (United States)

    Umanath, Kausik; Sika, Mohammed; Niecestro, Robert; Connelly, Carolyn; Schulman, Gerald; Koury, Mark J; Lewis, Julia B; Dwyer, Jamie P

    2013-01-01

    Chronic kidney disease associated mineral and bone disorders arise as a result of aberrant bone mineral metabolism in patients with advancing levels of renal dysfunction and end-stage renal disease. One of the cornerstones of treatment is the use of phosphate-binding agents. We describe the rationale and study design for a clinical trial to assess the safety and efficacy of ferric citrate as a phosphate binder. This trial is a three-period, international, multicenter, randomized, controlled clinical trial to assess the safety and efficacy of ferric citrate as a phosphate binder, consisting of a 2-week washout period, a 52-week safety assessment period in which subjects are randomized to ferric citrate or active control, and a 4-week efficacy assessment period in which subjects randomized to ferric citrate in the safety assessment period are randomized to ferric citrate or placebo. Eligible subjects include end-stage renal disease patients who have been treated with thrice-weekly hemodialysis or peritoneal dialysis for at least 3 months in dialysis clinics in the United States and Israel. Primary outcome measure will be the effect of ferric citrate vs. placebo on the change in serum phosphorus. Safety assessments will be performed by monitoring adverse events, concomitant medication use, and sequential blood chemistries (including iron parameters, phosphorus, and calcium). This three-period trial will assess the efficacy of ferric citrate as a phosphate binder. If proven safe and efficacious, ferric citrate will likely provide an additional phosphate binder to treat chronic kidney disease associated mineral and bone disorders. PMID:22702490

  4. Hydride Attack on a Coordinated Ferric Nitrosyl: Experimental and DFT Evidence for the Formation of a Heme Model-HNO Derivative.

    Science.gov (United States)

    Abucayon, Erwin G; Khade, Rahul L; Powell, Douglas R; Zhang, Yong; Richter-Addo, George B

    2016-01-13

    Heme-HNO species are crucial intermediates in several biological processes. To date, no well-defined Fe heme-HNO model compounds have been reported. Hydride attack on the cationic ferric [(OEP)Fe(NO)(5-MeIm)]OTf (OEP = octaethylporphyrinato dianion) generates an Fe-HNO product that has been characterized by IR and (1)H NMR spectroscopy. Results of DFT calculations reveal a direct attack of the hydride on the N atom of the coordinated ferric nitrosyl. PMID:26678216

  5. Microbial and hydrothermal aspects of ferric oxyhydroxides and ferrosic hydroxides: the example of Franklin Seamount, Western Woodlark Basin, Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Boyd TD

    2001-09-01

    Full Text Available Deposits of Fe-Si-Mn oxyhydroxides are commonly found on the seafloor on seamounts and mid-ocean spreading centers. At Franklin Seamount located near the western extremity of Woodlark Basin, Papua New Guinea, Fe-Si-Mn oxyhydroxides are being precipitated as chimneys and mounds upon a substrate of mafic lava. Previous studies have shown that the vent fluids have a low temperature (20–30°C and are characterized by a total dissolved iron concentration of 0.038 mM kg-1, neutral pH (6.26 and no measurable H2S. The chimneys have a yellowish appearance with mottled red–orange patches when observed in situ from a submersible, but collected samples become redder within a few hours of being removed from the sea. The amorphous iron oxyhydroxides, obtained from active and inactive vents, commonly possess filamentous textures similar in appearance to sheaths and stalks excreted by the iron-oxidizing bacteria Leptothrix and Gallionella; however, formless agglomerates are also common. Textural relationships between apparent bacterial and non-bacterial iron suggest that the filaments are coeval with and/or growing outwards from the agglomerates. The amorphous iron oxyhydroxides are suggested to precipitate hydrothermally as ferrosic hydroxide, a mixed-valence (Fe2+-Fe3+ green–yellow iron hydroxide compound. Consideration of the thermodynamics and kinetics of iron in the vent fluid, suggest that the precipitation is largely pH controlled and that large amounts of amorphous iron oxyhydroxides are capable of being precipitated by a combination of abiotic hydrothermal processes. Some biologically induced precipitation of primary ferric oxyhydroxides (two-XRD-line ferrihydrite may have occurred directly from the fluid, but most of the filamentous iron micro-textures in the samples appear to have a diagenetic origin. They may have formed as a result of the interaction between the iron-oxidizing bacteria and the initially precipitated ferrosic hydroxide that

  6. Bacterial Wound Culture

    Science.gov (United States)

    ... Home Visit Global Sites Search Help? Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  7. Bacterial Meningitis in Infants

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available A retrospective study of 80 infantile patients (ages 30-365 days; 47 male, 33 female with culture-proven bacterial meningitis seen over a 16 year period (1986-2001 is reported from Taiwan.

  8. Calibrating bacterial evolution

    OpenAIRE

    Ochman, Howard; Elwyn, Susannah; Moran, Nancy A

    1999-01-01

    Attempts to calibrate bacterial evolution have relied on the assumption that rates of molecular sequence divergence in bacteria are similar to those of higher eukaryotes, or to those of the few bacterial taxa for which ancestors can be reliably dated from ecological or geological evidence. Despite similarities in the substitution rates estimated for some lineages, comparisons of the relative rates of evolution at different classes of nucleotide sites indicate no basis for their universal appl...

  9. Bacterial leaching of discarded copper ores from Yongping, China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The elementary and phase analysis of discarded copper ores from Yongping of China has been performed. The experiments of extracting copper from the discarded copper ores were done with the mixed bacteria obtained through a series of enrichment,separation, domestication and combination tests. The results show that in the process of bioleaching, the pH value rises at first and drops gradually. The Eh value keeps rising along with the time and the appropriate Eh value varying between 750 and 800 mV will benefit the bioleaching copper. The high concentration of ferric ions is detrimental to the bioleaching copper. The results of bioleaching copper are good. That is, the copper recovery is 31.8% after 27 days.

  10. Protective Effect of Low Dose Gamma Irradiation against Oxidative Damage in Rats Administrated with Ferric- Nitrilotriacetate

    International Nuclear Information System (INIS)

    Many studies have demonstrated the beneficial adaptive response of low dose gamma-irradiation. Low dose gamma-irradiation (LDR) might be effective for the prevention of various reactive oxygen species-related diseases. Ferric nitrilotriacetate (Fe-NTA) is a strong oxidant, which generates highly reactive hydroxyl radical and causes injuries of various organs including the kidney and liver. This study was designed to investigate the ability of low dose gamma-irradiation to restrain Fe-NT A induced oxidative stress. Sprague Dawley male albino rats were subjected to low dose gamma-irradiation (50 cGy). Animals were challenged with Fe-NT A (9 mg Fe/kg body weight, intraperitoneally). Results showed that Fe-NTA enhances lipid peroxidation (LPx) accompanied with reduction in glutathione (GSH) content, antioxidant enzymes, viz., glutathione peroxidase (GPX), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and phase-U metabolizing enzyme glutathione-S-transferase (GST). Fe-NTA also enhances the concentration of blood urea nitrogen (BUN) and serum creatinine as well as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT) activities. Exposure to low dose gamma- irradiation (3 h after Fe-NTA administration) resulted in a significant decrease in LPx, BUN, serum creatinine contents as well as ALT, AST and GGT enzyme activities. GSH content; GST and antioxidant enzymes were also recovered to significant level. Thus, our data suggest that exposure to LDR might be a useful antioxidant mediator to suppress the Fe-NTA induced-oxidative damage in rats

  11. Hydrogen sulfide attenuates ferric chloride-induced arterial thrombosis in rats.

    Science.gov (United States)

    Qin, Yi-Ren; You, Shou-Jiang; Zhang, Yan; Li, Qian; Wang, Xian-Hui; Wang, Fen; Hu, Li-Fang; Liu, Chun-Feng

    2016-06-01

    Hydrogen sulfide (H2S) is a novel gaseous transmitter, regulating a multitude of biological processes in the cardiovascular and other systems. However, it remains unclear whether it exerts any effect on arterial thrombosis. In this study, we examined the effect of H2S on ferric chloride (FeCl3)-induced thrombosis in the rat common carotid artery (CCA). The results revealed a decrease of the H2S-producing enzyme cystathionine γ-lyase (CSE) expression and H2S production that persisted until 48 h after FeCl3 application. Intriguingly, administration with NaHS at appropriate regimen reduced the thrombus formation and enhanced the blood flow, accompanied with the alleviation of CSE and CD31 downregulation, and endothelial cell apoptosis in the rat CCA following FeCl3 application. Moreover, the antithrombotic effect of H2S was also observed in Rose Bengal photochemical model in which the development of thrombosis is contributed by oxidative injury to the endothelium. The in vitro study demonstrated that the mRNA and protein expression of CSE, as well as H2S production, was decreased in hydrogen peroxide (H2O2)-treated endothelial cells. Exogenous supplement of NaHS and CSE overexpression consistently alleviated the increase of cleaved caspase-3 and endothelial cell damage caused by H2O2. Taken together, our findings suggest that endogenous H2S generation in the endothelium may be impaired during arterial thrombosis and that modulation of H2S, either exogenous supplement or boost of endogenous production, may become a potential venue for arterial thrombosis therapy. PMID:26982248

  12. Effect of ferric and ferrous iron addition on phosphorus removal and fouling in submerged membrane bioreactors.

    Science.gov (United States)

    Zhang, Zhenghua; Wang, Yuan; Leslie, Greg L; Waite, T David

    2015-02-01

    The effect of continuously dosing membrane bioreactors (MBRs) with ferric chloride (Fe(III)) and ferrous sulphate (Fe(II)) on phosphorus (P) removal and membrane fouling is investigated here. Influent phosphorus concentrations of 10 mg/L were consistently reduced to effluent concentrations of less than 0.02 mg/L and 0.03-0.04 mg/L when an Fe(III)/P molar ratio of 4.0 and Fe/P molar ratio (for both Fe(II) and Fe(III)) of 2.0 were used, respectively. In comparison, effluent concentrations did not decrease below 1.35 mg/L in a control reactor to which iron was not added. The concentrations of supernatant organic compounds, particularly polysaccharides, were reduced significantly by iron addition. The sub-critical fouling time (tcrit) after which fouling becomes much more severe was substantially shorter with Fe(III) dosing (672 h) than with Fe(II) dosing (1200-1260 h) at Fe/P molar ratios of 2.0 while the control reactor (no iron dosing) exhibited a tcrit of 960 h. Not surprisingly, membrane fouling was substantially more severe at Fe/P ratios of 4. Fe(II) doses yielding Fe/P molar ratios of 2 or less with dosing to the aerobic chamber were found to be optimal in terms of P removal and fouling mitigation performance. In long term operation, however, the use of iron for maintaining appropriately low effluent P concentrations results in more severe irreversible fouling necessitating the application of an effective membrane cleaning regime. PMID:25482913

  13. Spin-coupling in ferric metalloporphyrin radical cation complexes: Mössbauer and susceptibility studies

    Science.gov (United States)

    Lang, George; Boso, Brian; Erler, Brian S.; Reed, Christopher A.

    1986-03-01

    The ferric metalloporphyrin π-radical cation complexes Fe(III) (OClO3)2 (TPP.) and [Fe(III) Cl (TPP.)] [SbCl6] were examined in microcrystalline form by Mössbauer spectroscopy and magnetic susceptometry over a range of temperatures and applied fields. All measurements on the six-coordinate Fe(OClO3)2 (TPP.) were consistent with isolated molecules having an S=5/2 iron site with zero field splitting (12 cm-1) S2z that is ferromagnetically coupled to the S=1/2 porphyrin radical by an energy term (-110 cm-1) Sṡs. Thus the ground state is overall spin-3. In the five-coordinate [FeCl (TPP.)] [SbCl6] the susceptibility is in reasonable agreement with the results of a calculation based on zero field splitting (12 cm-1) S2z for the S=5/2 iron and antiferromagnetic coupling (200 cm-1) Sṡs with the radical to give an overall spin-2 ground state. However, the Mössbauer measurements require a more complicated model having the same large intramolecular iron-radical coupling, a smaller zero field splitting (3 cm-1) S2z, and weak intermolecular antiferromagnetic coupling between heme pairs given by (32 cm-1) s1ṡs2 or, equivalently, (0.65 cm-1) S1ṡS2. A slightly improved correspondence with the measured susceptibility results. The intermolecular antiferromagnetic coupling probably results from crystallization of the [FeCl (TPP.)]+ cations in face-to-face dimers as observed in other closely related five-coordinate iron (III) porphyrins.

  14. Removal of arsenate with hydrous ferric oxide coprecipitation: effect of humic acid.

    Science.gov (United States)

    Du, Jingjing; Jing, Chuanyong; Duan, Jinming; Zhang, Yongli; Hu, Shan

    2014-02-01

    Insights from the adverse effect of humic acid (HA) on arsenate removal with hydrous ferric oxide (HFO) coprecipitation can further our understanding of the fate of As(V) in water treatment process. The motivation of our study is to explore the competitive adsorption mechanisms of humic acid and As(V) on HFO on the molecular scale. Multiple complementary techniques were used including macroscopic adsorption experiments, surface enhanced Raman scattering (SERS), extended X-ray absorption fine structure (EXAFS) spectroscopy, flow-cell attenuated total reflectance Fourier transform infrared (ATR-FTIR) measurement, and charge distribution multisite complexation (CD-MUSIC) modeling. The As(V) removal efficiency was reduced from over 95% to about 10% with the increasing HA concentration to 25 times of As(V) mass concentration. The SERS analysis excluded the HA-As(V) complex formation. The EXAFS results indicate that As(V) formed bidentate binuclear surface complexes in the presence of HA as evidenced by an As-Fe distance of 3.26-3.31 angstroms. The in situ ATR-FTIR measurements show that As(V) replaces surface hydroxyl groups and forms innersphere complex. High concentrations of HA may physically block the surface sites and inhibit the As(V) access. The adsorption of As(V) and HA decreased the point of zero charge of HFO from 7.8 to 5.8 and 6.3, respectively. The CD-MUSIC model described the zeta potential curves and adsorption edges of As(V) and HA reasonably well. PMID:25076514

  15. Sodium pyrophosphate enhances iron bioavailability from bouillon cubes fortified with ferric pyrophosphate.

    Science.gov (United States)

    Cercamondi, Colin I; Duchateau, Guus S M J E; Harika, Rajwinder K; van den Berg, Robin; Murray, Peter; Koppenol, Wieneke P; Zeder, Christophe; Zimmermann, Michael B; Moretti, Diego

    2016-08-01

    Fe fortification of centrally manufactured and frequently consumed condiments such as bouillon cubes could help prevent Fe deficiency in developing countries. However, Fe compounds that do not cause sensory changes in the fortified product, such as ferric pyrophosphate (FePP), exhibit low absorption in humans. Tetra sodium pyrophosphate (NaPP) can form soluble complexes with Fe, which could increase Fe bioavailability. Therefore, the aim of this study was to investigate Fe bioavailability from bouillon cubes fortified with either FePP only, FePP+NaPP, ferrous sulphate (FeSO4) only, or FeSO4+NaPP. We first conducted in vitro studies using a protocol of simulated digestion to assess the dialysable and ionic Fe, and the cellular ferritin response in a Caco-2 cell model. Second, Fe absorption from bouillon prepared from intrinsically labelled cubes (2·5 mg stable Fe isotopes/cube) was assessed in twenty-four Fe-deficient women, by measuring Fe incorporation into erythrocytes 2 weeks after consumption. Fe bioavailability in humans increased by 46 % (Pabsorption from bouillons fortified with FeSO4 only and with FeSO4+NaPP was 33·8 and 27·8 %, respectively (NS). The outcome from the human study is in agreement with the dialysable Fe from the in vitro experiments. Our findings suggest that the addition of NaPP could be a promising strategy to increase Fe absorption from FePP-fortified bouillon cubes, and if confirmed by further research, for other fortified foods with complex food matrices as well. PMID:27267429

  16. Rapid adsorption of arsenic from aqueous solution by ferrihydrite-coated sand and granular ferric hydroxide

    International Nuclear Information System (INIS)

    Highlights: • Column adsorption of arsenic species onto iron oxyhydroxides has been studied. • Sub-minute time scales are sufficient for the adsorption of arsenate and arsenite. • Moderate changes in pH affect breakthrough of arsenate but not that of arsenite. • Surface availability of iron is more important than high iron content. • Oxidation states of arsenic are preserved upon adsorption. - Abstract: The efficiency of As removal by Fe oxyhydroxide-based adsorbents was studied. Water containing micro-molar concentrations of As was cleaned using columns containing ferrihydrite-coated grains of sand or the commercial material granular ferric hydroxide, GFH®. Adsorption of considerable amounts of arsenate and arsenite were achieved on a sub-minute time scale with both adsorbents. Furthermore, efficient adsorption on GFH® can be achieved in seconds of empty bed contact time. Arsenate adsorption was affected by moderate changes in pH, while such an effect was negligible for arsenite. At slightly acidic pH substantially higher amounts of arsenate could be adsorbed. The Fe content of the coated sand was varied and it was found that more As was adsorbed on grains with a higher Fe content, however, the relationship was far from proportional. This is supported by scanning electron microscopy and energy dispersive spectroscopy, which showed that in addition to the occurrence of Fe in compounds coating the flakes, it also occurred adsorbed to the surface. The Fe oxyhydroxide coating was confirmed to be ferrihydrite using EXAFS spectroscopy. Batch experiments with ferrihydrite support the view that almost all can be adsorbed with a sufficient surplus of Fe oxide/hydroxide mineral suspension

  17. Oxidative stability of egg and soy lecithin as affected by transition metal ions and pH in emulsion.

    Science.gov (United States)

    Wang, Guang; Wang, Tong

    2008-12-10

    Oxidative stability of egg and soy lecithin in emulsion was evaluated with two transition metal ions, cupric and ferric ion, at two concentration levels (50 and 500 microM). The effect of pH on lipid oxidation was also examined under these two concentrations for each ion. Egg lecithin (EL) had similar peroxide value (PV) development pattern as soy lecithin (SL) when treated with cupric ion under both acidic and neutral pH. Acidic pH of 3 accelerated oxidation of both EL and SL, especially under high concentration of copper. When treated with ferric ion, EL oxidized much faster than SL did. EL had higher value of thiobarbituric acid-reactive substances (TBARS) than SL, possibly because of its higher content of long-chain polyunsaturated fatty acids (PUFA). Acidic pH accelerated TBARS development for both EL and SL, but EL had more significantly increased values. Cupric ion was more powerful than ferric in catalyzing oxidation of both EL and SL under both acidic and neutral pH conditions as measured by PV and TBARS. Linoleic acid may contribute to higher PV production, however, arachidonic acid and docosahexaenoic acid may have contributed more to TBARS production. Overall, SL showed better oxidative stability than EL under the experimental conditions. This study also suggests that using multiple methods is necessary in properly evaluating lipid oxidative stability. PMID:18991454

  18. Bacterial Acclimation Inside an Aqueous Battery.

    Directory of Open Access Journals (Sweden)

    Dexian Dong

    Full Text Available Specific environmental stresses may lead to induced genomic instability in bacteria, generating beneficial mutants and potentially accelerating the breeding of industrial microorganisms. The environmental stresses inside the aqueous battery may be derived from such conditions as ion shuttle, pH gradient, free radical reaction and electric field. In most industrial and medical applications, electric fields and direct currents are used to kill bacteria and yeast. However, the present study focused on increasing bacterial survival inside an operating battery. Using a bacterial acclimation strategy, both Escherichia coli and Bacillus subtilis were acclimated for 10 battery operation cycles and survived in the battery for over 3 days. The acclimated bacteria changed in cell shape, growth rate and colony color. Further analysis indicated that electrolyte concentration could be one of the major factors determining bacterial survival inside an aqueous battery. The acclimation process significantly improved the viability of both bacteria E. coli and B. subtilis. The viability of acclimated strains was not affected under battery cycle conditions of 0.18-0.80 mA cm(-2 and 1.4-2.1 V. Bacterial addition within 1.0×10(10 cells mL(-1 did not significantly affect battery performance. Because the environmental stress inside the aqueous battery is specific, the use of this battery acclimation strategy may be of great potential for the breeding of industrial microorganisms.

  19. Bacterial meningitis in children

    International Nuclear Information System (INIS)

    To demonstrate the epidemiology, clinical manifestations and bacteriological profile of bacterial meningitis in children beyond the neonatal period in our hospital. This was a retrospective descriptive study conducted at Prince Rashid Hospital in Irbid, Jordan. The medical records of 50 children with the diagnosis of bacterial meningitis during 4 years period, were reviewed. The main cause of infection was streptococcus pneumoniae, followed by Haemophilus influenza and Niesseria meningitides. Mortality was higher in infants and meningococcal infection, while complications were more encountered in cases of streptococcus pneumoniae. Cerebrospinal fluid culture was positive in 11 cases and Latex agglutination test in 39. There is a significant reduction of the numbers of bacterial meningitis caused by Haemophilus influenza type B species. (author)

  20. Diagnosis of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Đukić Slobodanka

    2013-01-01

    Full Text Available Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2­producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent’s scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up­to­date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short­term and long­term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  1. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria.......Biofilm resilience poses major challenges to the development of novel antimicrobial agents. Biofilm bacteria can be considered small groups of “Special Forces” capable of infiltrating the host and destroying important components of the cellular defense system with the aim of crippling the host...

  2. An EXAFS study of the interaction of substrate with the ferric active site of protocatechuate 3,4-dioxygenase

    Energy Technology Data Exchange (ETDEWEB)

    True, A.E.; Orville, A.M.; Pearce, L.L.; Lipscomb, J.D.; Que, L. Jr. (Univ. of Minnesota, Minneapolis (USA))

    1990-12-01

    X-ray crystallographic studies of the intradiol cleaving protocatechuate 3,4-dioxygenase from Pseudomonas aeruginosa have shown that the enzyme has a trigonal bipyramidal ferric active site with two histidines, two tyrosines, and a solvent molecule as ligands. Fe K-edge EXAFS studies of the spectroscopically similar protocatechuate 3,4-dioxygenase from Brevibacterium fuscum are consistent with a pentacoordinate geometry of the iron active site with 3 O/N ligands at 1.90 {angstrom} and 2 O/N ligands at 2.08 {angstrom}. The 2.08-{angstrom} bonds are assigned to the two histidines, while the 1.90-{angstrom} bonds are associated with the two tyrosines and the coordinated solvent. The short Fe-O distance for the solvent suggests that it coordinates as hydroxide rather than water. When the inhibitor terephthalate is bound to the enzyme, the XANES data indicate that the ferric site becomes 6-coordinate and the EXAFS data show a beat pattern which can only be simulated with an additional Fe-O/N interaction at 2.46 {angstrom}. Together, the data suggest that the oxygens of the carboxylate group in terephthalate displace the hydroxide and chelate to the ferric site but in an asymmetric fashion. In contrast, protocatechuate 3,4-dioxygenase remains 5-coordinate upon the addition of the slow substrate homoprotocatechuic acid (HPCA). Previous EPR data have indicated that HPCA forms an iron chelate via the two hydroxyl functions. For the iron site to remain 5-coordinate and the HPCA to be chelated to the iron, the substrate must displace not only the hydroxide but also a ligand from the protein backbone, probably a histidine. The mechanistic implications of the displacement of hydroxide and a protein ligand in the active site are discussed.

  3. Synthesis of carbon-encapsulated iron carbide/iron nanoparticles from phenolic-formaldehyde resin and ferric nitrate

    International Nuclear Information System (INIS)

    Carbon-encapsulated iron carbide/iron nanoparticles have been synthesized on a large scale by the heat treatment of thermal plastic phenolic-formaldehyde resin with the aid of ferric nitrate. The effects of heating temperature on the morphologies and structures of carbonized products were investigated using transmission electron microscope, high-resolution transmission electron microscope and X-ray diffraction measurements. The products with diameter distribution of 20-100 nm consisted mainly of spheroidal nanoparticles separated by hollow onion-like carbon nanoparticles.

  4. Summary on Ferric Chloride Anhydrous Production%无水三氯化铁生产运行总结

    Institute of Scientific and Technical Information of China (English)

    卢峰

    2014-01-01

    In ferric chloride anhydrous production operation condition, improve the process, reduce consumption, improve operational control level, stable safety production and protecting the environment and social benefit is remarkable.%介绍了无水三氯化铁生产运行状况。通过实践改进工艺,降低消耗,提高操作控制水平,达到安全生产,环境、社会效益显著。

  5. The Effects of Two Different Doses of Iron in Ferric Form in Treatment of Childhood Iron Deficiency Anemia

    OpenAIRE

    Ünüvar, Emin; Oğuz, Fatma; Şahin, Kamil; Sıdal, Müjgan

    1999-01-01

    Objectives: To determine the effectiveness of two different doses of iron in ferric form in the treatment of iron deficiency anemia in children 3 vs 6 mg kg day nbsp; Methods: In this prospective open sided randomly syncronised study 130 cases diagnosed as iron deficiency anemia Hb lt; 11 gr dl Hct lt; 34 serum iron saturation index lt; 12 ferritin lt; 12 ng ml were divided into two groups: Group 1 n:65 received 6 mg kg d and Group 2 n:65 received 3 mg kg d iron orally The duration of treatme...

  6. Potential side effects of ammonium-ferric-hexacyano-ferrate application: enhanced radiostrontium transfer and free cyanide release

    Energy Technology Data Exchange (ETDEWEB)

    Vandenhove, Hildegarde E-mail:hvandenh@sckcen.be; Hees, May van; Vandecasteele, Christian

    2000-01-01

    The effect of the application of ammonium-ferric-hexacyano-ferrate (AFCF), effective in reducing soil-to-plant radiocaesium transfer, on radiostrontium transfer was tested for ryegrass grown under greenhouse conditions on sandy soil for 310 days. Identical radiostrontium transfer factors (9.4 kg kg{sup -1}) were obtained with 0 or 10 g AFCF m{sup -2} applied. Amending AFCF to planted or uncovered sandy or loamy soils in quantities of up to 100 g AFCF m{sup -2} did not result in detectable levels of free cyanide. Negative side effects of AFCF application to soil are hence unlikely.

  7. Effect of ferric oxyhydroxide grain coatings on the transport of bacteriophage PRD1 and Cryptosporidium parvum oocysts in saturated porous media

    Science.gov (United States)

    Abudalo, R.A.; Bogatsu, Y.G.; Ryan, J.N.; Harvey, R.W.; Metge, D.W.; Elimelech, M.

    2005-01-01

    To test the effect of geochemical heterogeneity on microorganism transport in saturated porous media, we measured the removal of two microorganisms, the bacteriophage PRD1 and oocysts of the protozoan parasite Cryptosporidium parvum, in flow-through columns of quartz sand coated by different amounts of a ferric oxyhydroxide. The experiments were conducted over ranges of ferric oxyhydroxide coating fraction of ?? = 0-0.12 for PRD1 and from ?? = 0-0.32 for the oocysts at pH 5.6-5.8 and 10-4 M ionic strength. To determine the effect of pH on the transport of the oocysts, experiments were also conducted over a pH range of 5.7-10.0 at a coating fraction of ?? = 0.04. Collision (attachment) efficiencies increased as the fraction of ferric oxyhydroxide coated quartz sand increased, from ?? = 0.0071 to 0.13 over ?? = 0-0.12 for PRD1 and from ?? = 0.059 to 0.75 over ?? = 0-0.32 for the oocysts. Increasing the pH from 5.7 to 10.0 resulted in a decrease in the oocyst collision efficiency as the pH exceeded the expected point of zero charge of the ferric oxyhydroxide coatings. The collision efficiencies correlated very well with the fraction of quartz sand coated by the ferric oxyhydroxide for PRD1 but not as well for the oocysts. ?? 2005 American Chemical Society.

  8. Bacterial extracellular lignin peroxidase

    Science.gov (United States)

    Crawford, Donald L.; Ramachandra, Muralidhara

    1993-01-01

    A newly discovered lignin peroxidase enzyme is provided. The enzyme is obtained from a bacterial source and is capable of degrading the lignin portion of lignocellulose in the presence of hydrogen peroxide. The enzyme is extracellular, oxidative, inducible by lignin, larch wood xylan, or related substrates and capable of attacking certain lignin substructure chemical bonds that are not degradable by fungal lignin peroxidases.

  9. Bacterial Skin Infections

    Science.gov (United States)

    ... or scraped, the injury should be washed with soap and water and covered with a sterile bandage. Petrolatum may be applied to open areas to keep the tissue moist and to try to prevent bacterial invasion. Doctors recommend that people do not use ...

  10. Bacterial microflora of nectarines

    Science.gov (United States)

    Microflora of fruit surfaces has been the best source of antagonists against fungi causing postharvest decays of fruit. However, there is little information on microflora colonizing surfaces of fruits other than grapes, apples, and citrus fruit. We characterized bacterial microflora on nectarine f...

  11. BIOSORPTION OF CHROMIUM(Ⅵ) IONS FROM AQUEOUS SOLUTION BY A NOVEL BACTERIAL EXOPOLYMERS%细菌胞外高聚物对水中六价铬的生物吸附特性

    Institute of Scientific and Technical Information of China (English)

    王竞; 陶颖; 周集体; 宫小燕

    2001-01-01

    Biosorption of Chromium(Ⅵ) was investigated by a Novel Bacterial exopolymers from Pseudomonas sp GX4-1. It was found that the optimum initial pH for Cr(Ⅵ) biosorption is 0.5-2.0; the biosorption process may be divided into the following phases:1)a fast biosorption phase with 75% Cr(Ⅵ) uptaken within 5 min: 2)first-order kinetics phase from 10 to 40min; 3)equilibrium phase; and biosorption process is fit for Languir model.%本文研究了一新型细胞外聚合物WJ-I对水中重金属Cr(Ⅵ)的吸附特性。结果表明,WJ-I对Cr(Ⅵ)吸附的最佳pH为0.5~2.0。Cr(Ⅵ)的吸附可分为三个阶段;快速吸附阶段(5min);一级动力学吸附阶段(10~40min);吸附平衡阶段(50min以后)。整个吸附过程符合langmuir吸附模型。

  12. Status of the MEIC ion collider ring design

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-07-14

    We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

  13. Status of the MEIC ion collider ring design

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Derbenev, Yaroslav [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Harwood, Leigh [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Hutton, Andrew [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Pilat, Fulvia [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Cai, Yunhai [SLAC National Accelerator Lab., Menlo Park, CA (United States); Nosochkov, Y. M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Sullivan, Michael [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wang, M.-H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wienands, Uli [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gerity, James [Texas A & M Univ., College Station, TX (United States); Mann, Thomas [Texas A & M Univ., College Station, TX (United States); McIntyre, Peter [Texas A & M Univ., College Station, TX (United States); Pogue, Nathaniel [Texas A & M Univ., College Station, TX (United States); Sattarov, Akhdiyor [Texas A & M Univ., College Station, TX (United States)

    2015-09-01

    We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

  14. Heme uptake in bacterial pathogens

    OpenAIRE

    Contreras, Heidi; Chim, Nicholas; Credali, Alfredo; Goulding, Celia W.

    2014-01-01

    Iron is an essential nutrient for the survival of organisms. Bacterial pathogens possess specialized pathways to acquire heme from their human hosts. In this review, we present recent structural and biochemical data that provide mechanistic insights into several bacterial heme uptake pathways, encompassing the sequestration of heme from human hemoproteins to secreted or membrane-associated bacterial proteins, the transport of heme across bacterial membranes, and the degradation of heme within...

  15. Acupuncture inhibits ferric iron deposition and ferritin-heavy chain reduction in an MPTP-induced parkinsonism model.

    Science.gov (United States)

    Choi, Yeong-Gon; Park, Jae-Hyun; Lim, Sabina

    2009-01-30

    This study investigated the effect of acupuncture on iron-related oxidative damage in a mouse model designed as a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism model. To generate the chronic parkinsonism model, mice were intraperitoneally injected with MPTP (20mg/kg, one daily injection) for 30 days and acupuncture was performed at acupoints LR3 (Taichong) and GB34 (Yanglingquan) at 48h intervals. Acupuncture inhibited decreases in the immunoreactivities of tyrosine hydroxylase (TH) and dopamine transporter (DAT) that occurred as a result of MPTP neurotoxicity. The presence of ferric iron (Fe(3+)), but not ferrous iron (Fe(2+)), was strongly increased in the substantia nigra (SN) as a result of chronic loading of MPTP, whereas the ferritin-heavy chain (F-H) was significantly decreased. However, acupuncture treatment inhibited the increase in ferric iron and the decrease in the F-H that was induced by MPTP. Additionally, treatment with MPTP and acupuncture caused no changes in the presence of ferrous iron and ferritin-light chain (F-L) as a result of the treatments. The mRNA of F-H was also not affected. These results suggest that acupuncture may inhibit iron-related oxidative damage and may prevent the deleterious alteration of iron metabolism in the MPTP model. PMID:19056464

  16. Expression, crystallization and preliminary X-ray analysis of a ferric binding protein from Thermus thermophilus HB8

    International Nuclear Information System (INIS)

    The cloning, expression, purification, crystallization and preliminary X-ray analysis of a ferric binding protein encoded by T. thermophilus HB8 in apo and iron-bound holo states are presented. Four different crystal forms were obtained. A ferric binding protein from Thermus thermophilus HB8 (TtFbpA) was expressed, purified and crystallized using the hanging-drop vapour-diffusion method. Four different crystal forms were obtained and characterized by X-ray diffraction. Two crystal forms with TtFbpA in the apo state belonged to the orthorhombic space group P212121 (unit-cell parameters a = 42.1, b = 139.3, c = 326.5 Å and a = 42.1, b = 139.3, c = 218.9 Å). The third form with TtFbpA also in the apo state belonged to the monoclinic space group P21 (unit-cell parameters a = 66.5, b = 61.7, c = 73.9 Å, β = 111.7°). The fourth form, with TtFbpA in the iron-bound holo state as confirmed by an atomic absorption spectrophotometry assay, belonged to the trigonal space group P3121 or P3221 (unit-cell parameters a = 63.6, b = 63.6, c = 266.7 Å, α = β = 90.0, γ = 120.0°)

  17. Extraction of uranium from coarse ore and acid-curing and ferric sulphate-trickle leaching process

    International Nuclear Information System (INIS)

    On the basis of analysis of the problems in the technology of the traditional uranium hydrometallurgy and the limitations of thin layer leaching process (TLL), a new leaching system-acid-curing and ferric sulphate-trickle leaching (AFL) process (NGJ in Chinese) has developed for extraction of uranium from the coarse ore. The ferric sulphate solution was used for trickling the acid-cured uranium ore and the residual leaching reaction incomplete in TLL process can be improved in this process. And the AFL process has a wide applicability to China's uranium ores, being in competition with the traditional agitation leaching process for treating coarse ores. The uranium ore processing technology based on the AFL process will become one of the new basic technologies of uranium hydrometallurgy. A series of difficulties will be basically overcome associated with fine grinding because of its elimination in the presented process. Moreover, the situation of the present uranium hydrometallurgy can be also changed owing to without technological effluent discharge

  18. Evolutionary transitions in bacterial symbiosis

    OpenAIRE

    Sachs, Joel L.; Skophammer, Ryan G.; Regus, John U.

    2011-01-01

    Diverse bacterial lineages form beneficial infections with eukaryotic hosts. The origins, evolution, and breakdown of these mutualisms represent important evolutionary transitions. To examine these key events, we synthesize data from diverse interactions between bacteria and eukaryote hosts. Five evolutionary transitions are investigated, including the origins of bacterial associations with eukaryotes, the origins and subsequent stable maintenance of bacterial mutualism with hosts, the captur...

  19. Effects of phosphate and silicate on the transformation of hydroxycarbonate green rust to ferric oxyhydroxides

    Science.gov (United States)

    Feng, Xionghan; Wang, Xiaoming; Zhu, Mengqiang; Koopal, Luuk K.; Xu, Huanhuan; Wang, Yan; Liu, Fan

    2015-12-01

    Hydroxycarbonate green rust (GR1(CO32-)) was prepared by oxidation of aerated aqueous suspensions of Fe(II) hydroxide, and the presence of light promoted the transformation of GR1(CO32-) by dissolved O2 at pH 7.8 and 25 °C. Further transformation of GR1(CO32-) in the light was conducted in the presence of orthophosphate (P) or silicate (Si) anions, followed by solution analysis and solid product characterization using X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). Results show that both P and Si anions significantly affect the transformation of GR1(CO32-) through adsorption on the intermediate products. The time required for complete GR1(CO32-) transformation and the phases, crystallinity and morphology of the transformation products all depend on the Fe/anion molar ratio. When compared to the control, the transformation can be promoted by low Si concentrations but retarded by P. With decreasing Fe/P ratio, the products change from acicular goethite (absence of P) to tabular lepidocrocite (Fe/P: 120-48) and to mixed phases of platelets of ferric GR1(CO32-) (EX-GR1) and minor ferrihydrite (Fe/P: 24-3). In terms of Si, the products are goethites when the Fe/Si ratio of 48-12, and with increasing ratio, the goethite crystallinity and particle size decrease and the morphology changes from acicular (absence of Si) to plate-like or isodimensional particles. The goethite morphology at low Fe/Si ratios is comparable to natural goethite samples commonly found in soils. At Fe/Si = 3, the products are EX-GR1 platelets with minor ferrihydrite coexisting. The likely pathway of the oxidative GR1(CO32-) transformation in the control system and in the presence of low concentrations of Si (Fe/Si ⩾ 12) is GR1(CO32-) → amorphous γ-FeOOH-like phase → α-FeOOH via a dissolution-oxidation-precipitation mechanism. In addition, Fe(II) released during dissolution of GR1(CO32-) is adsorbed on the products and the

  20. Ferric Iron Precipitation in the Nagahama Bay, Satsuma Iwo-Jima Island, Kagoshima

    Science.gov (United States)

    Nagata, T.; Kiyokawa, S.; Ikehara, M.; Oguri, K.; Goto, S.; Ito, T.; Yamaguchi, K. E.; Ueshiba, T.

    2010-12-01

    Satsuma-Iwojima island is active volcanic island and 6 x 3 km in size, located 38km south of Kyushu island, Japan. The reddish brown water along the coast of the Iwo-dake volcano at the center of the island formed by neutralization through mixing of shallow hydrothermal fluid and seawater. The reddish brown water contains reddish ferrihydrite (Fe3+) that is derived from oxidation of Fe2+ from acidic hot spring (Shikaura and Tazaki, 2001). In the Nagahama Bay with its opening to the south, red-colored Fe-rich water is affected by tidal current, but sedimentation of the ferric hydroxide is confirmed to occur in the ocean bottom (Ninomiya and Kiyokawa, 2009). Here we focus other lines of evidence from long term observations and meteorological records as important factor to form thick iron rich sediments. Meteorological and stationary observations: We used weather record in the Satsuma Iwo-jima and cross-checked with stationary observations, which enabled us to observe color changes of the surface of Nagahama Bay. It was made clear that north wind condition in the Nagahama Bay resulted in changes of the color of its surface, from red to green, by intrusion of ocean water coming from outside. Long term temperature monitoring: The temperature of seawater in the Nagahama Bay fluctuated synchronically with the air temperature. But that of hot spring water rather remained constant regardless of the seasonal change. We observed that seawater temperature in the Nagahama Bay is low at high tide and high at low tide, and the rage of temperature change is maximum at the spring tide and minimum at the neap tide. In other words, the amount of discharge of hot spring and that of seawater inflow vary inversely. Core sample: In the Nagahama Bay, iron rich sediments that is more than 1 m thick were identified. The core sample shows lithology as following; upper part, 10-20cm thick, formed loose Fe-rich deposit, lower portion formed alteration of weakly consolidated Fe-rich orange

  1. Dose-related effects of ferric citrate supplementation on endoplasmic reticular stress responses and insulin signalling pathways in streptozotocin-nicotinamide-induced diabetes.

    Science.gov (United States)

    Liu, Kai-Li; Chen, Pei-Yin; Wang, Chi-Mei; Chen, Wei-Yu; Chen, Chia-Wen; Owaga, Eddy; Chang, Jung-Su

    2016-01-01

    Diabetic patients are at high risk of developing anemia; however, pharmacological doses of iron supplementation may vary greatly depending on diabetes-related complications. The aim of this study was to investigate the dose-dependent effect of iron on glucose disposal with a special focus on endoplasmic reticular (ER) stress, iron metabolism, and insulin signalling pathways. Diabetes was induced in overnight fasted rats by intraperitoneal (i.p.) injections of 40 mg kg(-1) streptozotocin (STZ) and 100 mg kg(-1) nicotinamide. Diabetic rats were fed a standard diet (36.7 mg ferric iron per kg diet) or pharmacological doses of ferric citrate (0.5, 1, 2, and 3 g ferric iron per kg diet). Ferric citrate supplementation showed a dose-related effect on hepatic ER stress responses and total iron levels, which were associated with increased hepcidin and decreased ferroportin expressions. Iron-fed rats had increased sizes of their pancreatic islets and hyperinsulinemia compared to rats fed a standard diet. A western blot analysis revealed that iron feeding decreased total insulin receptor substrate 1 (IRS1), phosphorylated IRS1ser307, and AS160 but increased phosphorylated GSK-3β. Iron supplementation inhibited the nuclear translocation of AKT but promoted FOXO1 translocation to nuclei. Ferric citrate supplementation showed a dose-related effect on ER stress responses, hepatic iron, and the insulin signaling pathway. Adverse effects were more evident at high iron doses (>1 g ferric iron per kg diet), which is equivalent to a 60 kg human male consuming >500 mg elemental iron per day. PMID:26611621

  2. [Bacterial diseases of rape].

    Science.gov (United States)

    Zakharova, O M; Mel'nychuk, M D; Dankevych, L A; Patyka, V P

    2012-01-01

    Bacterial destruction of the culture was described and its agents identified in the spring and winter rape crops. Typical symptoms are the following: browning of stem tissue and its mucilagization, chlorosis of leaves, yellowing and beginning of soft rot in the place of leaf stalks affixion to stems, loss of pigmentation (violet). Pathogenic properties of the collection strains and morphological, cultural, physiological, and biochemical properties of the agents of rape's bacterial diseases isolated by the authors have been investigated. It was found that all the isolates selected by the authors are highly or moderately aggressive towards different varieties of rape. According to the complex of phenotypic properties 44% of the total number of isolates selected by the authors are related to representatives of the genus Pseudomonas, 37% - to Xanthomonas and 19% - to Pectobacterium. PMID:23293826

  3. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing...... tolerance to adverse conditions such as those experienced in the host. In the membrane, HtrA performs similar functions whereas the extracellular proteases, in close contact with host components, pave the way for spreading infections by degrading host matrix components or interfering with host cell...... cell. These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  4. Supramolecular bacterial systems

    OpenAIRE

    Sankaran, Shrikrishnan

    2015-01-01

    For nearly over a decade, a wide variety of dynamic and responsive supramolecular architectures have been investigated and developed to address biological systems. Since the non-covalent interactions between individual molecular components in such architectures are similar to the interactions found in living systems, it was possible to integrate chemically-synthesized and naturally-occurring components to create platforms with interesting bioactive properties. Bacterial cells and recombinant ...

  5. Bacterial transformation of terpenoids

    International Nuclear Information System (INIS)

    Data on the bacterial transformation of terpenoids published in the literature in the past decade are analyzed. Possible pathways for chemo-, regio- and stereoselective modifications of terpenoids are discussed. Considerable attention is given to new technological approaches to the synthesis of terpenoid derivatives suitable for the use in the perfume and food industry and promising as drugs and chiral intermediates for fine organic synthesis. The bibliography includes 246 references

  6. PEROXOTITANATE- AND MONOSODIUM METAL-TITANATE COMPOUNDS AS INHIBITORS OF BACTERIAL GROWTH

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.

    2011-01-19

    Sodium titanates are ion-exchange materials that effectively bind a variety of metal ions over a wide pH range. Sodium titanates alone have no known adverse biological effects but metal-exchanged titanates (or metal titanates) can deliver metal ions to mammalian cells to alter cell processes in vitro. In this work, we test a hypothesis that metal-titanate compounds inhibit bacterial growth; demonstration of this principle is one prerequisite to developing metal-based, titanate-delivered antibacterial agents. Focusing initially on oral diseases, we exposed five species of oral bacteria to titanates for 24 h, with or without loading of Au(III), Pd(II), Pt(II), and Pt(IV), and measuring bacterial growth in planktonic assays through increases in optical density. In each experiment, bacterial growth was compared with control cultures of titanates or bacteria alone. We observed no suppression of bacterial growth by the sodium titanates alone, but significant (p < 0.05, two-sided t-tests) suppression was observed with metal-titanate compounds, particularly Au(III)-titanates, but with other metal titanates as well. Growth inhibition ranged from 15 to 100% depending on the metal ion and bacterial species involved. Furthermore, in specific cases, the titanates inhibited bacterial growth 5- to 375-fold versus metal ions alone, suggesting that titanates enhanced metal-bacteria interactions. This work supports further development of metal titanates as a novel class of antibacterials.

  7. An investigation of magnox sludge and alumino-ferric floc waste simulate, immobilised by a cementitious matrix

    International Nuclear Information System (INIS)

    Magnox sludge and alumino ferric floc simulates, prepared using non-radioactive tracers were immobilised by a cementitious system. Formulation design aimed at optimising pollutant leaching with permeability and compressive strength as secondary considerations. The behaviour of the products under accelerated weathering conditions was investigated. The study was divided into two parts: Formulation design in Phase I and the systematic testing of the optimum formulations under freeze-thaw, and hydration -dehydration conditions in Phase 2. Analytical method development for leachate analysis continued through both Phases. The Barnwood method of leach testing was used. The immobilised waste had good physical properties (i.e. high strength and low permeability) and a significant improvement was achieved during the course of the work in the leach rates of the tracers, particularly of caesium and strontium. (author)

  8. Spin-state crossover and hyperfine interactions of ferric iron in MgSiO$_3$ perovskite

    CERN Document Server

    Hsu, Han; Cococcioni, Matteo; Wentzcovitch, Renata M

    2011-01-01

    Using density functional theory plus Hubbard $U$ calculations, we show that the ground state of (Mg,Fe)(Si,Fe)O$_3$ perovskite, a major mineral phase in the Earth's lower mantle, has high-spin ferric iron ($S=5/2$) at both the dodecahedral (A) and octahedral (B) site. As the pressure increases, the B-site iron undergoes a spin-state crossover to the low-spin state ($S=1/2$), while the A-site iron remains in the high-spin state. Our calculation shows that the B-site spin-state crossover in the pressure range of 40-70 GPa is accompanied by a noticeable volume reduction and an increase in quadrupole splitting, consistent with recent X-ray diffraction and M\\"ossbauer spectroscopy measurements. The volume reduction leads to a significant softening in the bulk modulus, which suggests a possible source of seismic velocity anomalies in the lower mantle.

  9. Bacterial disproportionation of elemental sulfur coupled to chemical reduction of iron or manganese

    DEFF Research Database (Denmark)

    Thamdrup, Bo; Finster, Kai; Hansen, Jens Würgler;

    1993-01-01

    A new chemolithotrophic bacterial metabolism was discovered in anaerobic marine enrichment cultures. Cultures in defined medium with elemental sulfur (S) and amorphous ferric hydroxide (FeOOH) as sole substrates showed intense formation of sulfate. Furthermore, precipitation of ferrous sulfide and...... the formed sulfide and the added FeOOH led to the observed precipitation of iron sulfides. Sulfate and iron sulfides were also produced when FeOOH was replaced by FeCO(3). Further enrichment with manganese oxide, MnO(2), instead of FeOOH yielded stable cultures which formed sulfate during concomitant...... reduction of MnO(2) to Mn. Growth of small rod-shaped bacteria was observed. When incubated without MnO(2), the culture did not grow but produced small amounts of SO(4) and H(2)S at a ratio of 1:3, indicating again a disproportionation of S. The observed microbial disproportionation of S only proceeds...

  10. Bacterially Antiadhesive, Optically Transparent Surfaces Inspired from Rice Leaves.

    Science.gov (United States)

    Oh, Jun Kyun; Lu, Xiaoxu; Min, Younjin; Cisneros-Zevallos, Luis; Akbulut, Mustafa

    2015-09-01

    Because of the growing prevalence of antimicrobial resistance strains, there is an increasing need to develop material surfaces that prevent bacterial attachment and contamination in the absence of antibiotic agents. Herein, we present bacterial antiadhesive materials inspired from rice leaves. "Rice leaf-like surfaces" (RLLS) were fabricated by a templateless, self-masking reactive-ion etching approach. Bacterial attachment on RLLS was characterized under both static and dynamic conditions using Gram-negative Escherichia coli O157:H7 and Gram-positive Staphylococcus aureus. RLLS surfaces showed exceptional bacterial antiadhesion properties with a >99.9% adhesion inhibition efficiency. Furthermore, the optical properties of RLLS were investigated using UV-vis-NIR spectrophotometry. In contrast to most other bacterial antiadhesive surfaces, RLLS demonstrated optical-grade transparency (i.e., ≥92% transmission). We anticipate that the combination of bacterial antiadhesion efficiency, optical grade transparency, and the convenient single-step method of preparation makes RLLS a very attractive candidate for the surfaces of biosensors; endoscopes; and microfluidic, bio-optical, lab-on-a-chip, and touchscreen devices. PMID:26237234

  11. Studies on the preparation of ferric-hydroxide macro aggregate and hydroxyapatite particles labelled with Sm-153, Ho-166 and/or Dy-165 for radiation synovectomy

    International Nuclear Information System (INIS)

    The modified methods for the preparation of Hydroxyapatite particle (HA) and Ferric Hydroxide Macro Aggregated (FHMA of high stability and uniformity in particle size and of good geometrical shape suitable for production of radiolabeled carrier for radiation synovectomy purpose were developed. 165Dy, 166Ho and/or 153Sm labeled HA and FHMA were produced using a simple labelling method. (author)

  12. Comparative study of safety and efficacy of intravenous iron sucrose and ferric carboxymaltose in the treatment of postpartum iron deficiency anaemia

    Directory of Open Access Journals (Sweden)

    Alpana Singh

    2016-04-01

    Conclusions: Ferric carboxymaltose has a greater safety profile (p and offers faster elevation of haemoglobin and iron stores with lesser hospital stay as compared to iron sucrose. [Int J Reprod Contracept Obstet Gynecol 2016; 5(4.000: 1130-1133

  13. Ferric chloride-catalyzed reaction of [60]fullerene with tert-butyl N-substituted carbamates: synthesis of oxazolidino[4,5:1,2][60]fullerenes.

    Science.gov (United States)

    You, Xun; Wang, Guan-Wu

    2014-01-01

    The rare oxazolidinofullerenes have been prepared by the ferric chloride-catalyzed reaction of [60]fullerene with various tert-butyl N-substituted carbamates via t-Bu-O bond cleavage and heteroannulation under mild conditions. A possible mechanism for the formation of oxazolidinofullerenes is proposed. PMID:24328055

  14. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    This PhD project was carried out as part of the Microbial Remediation of Contaminated Soil and Water Resources (MIRESOWA) project, funded by the Danish Council for Strategic Research (grant number 2104-08-0012). The environment is contaminated with various xenobiotic compounds e.g. pesticides......D student, to construct fungal-bacterial consortia in order to potentially stimulate pesticide degradation thereby increasing the chance of successful bioaugmentation. The results of the project are reported in three article manuscripts, included in this thesis. In manuscript I, the mineralization of 2...

  15. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte; Kruse, Torben; Nordström, Kurt

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the P......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  16. Bacterial terpene cyclases.

    Science.gov (United States)

    Dickschat, Jeroen S

    2016-01-01

    Covering: up to 2015. This review summarises the accumulated knowledge about characterised bacterial terpene cyclases. The structures of identified products and of crystallised enzymes are included, and the obtained insights into enzyme mechanisms are discussed. After a summary of mono-, sesqui- and diterpene cyclases the special cases of the geosmin and 2-methylisoborneol synthases that are both particularly widespread in bacteria will be presented. A total number of 63 enzymes that have been characterised so far is presented, with 132 cited references. PMID:26563452

  17. Alanine dosimetry using a spectrophotometric ferric-xylenol orange complex readout

    Energy Technology Data Exchange (ETDEWEB)

    Laere, K. van; Buysse, J.; Berkvens, P. (Ghent Rijksuniversiteit (Belgium). Lab. voor Kernfysica)

    1989-01-01

    The spectrophotometric dosimetric method using the indirect oxidation of ferrous ions after dissolution of irradiated DL-and L-alanine has been thoroughly investigated with respect to its composition, read-out procedure and dose-response. Optimal concentration of 0.10 N H{sub 2}SO{sub 4}, 0.2 mM xylenol orange and 0.2 mM Fe{sup 2+} were found, giving an absorption maximum at 547 nm. Standardization of chemical processing procedures allows a reproducibility better than 0.5%. The useful dose range has been extended to 0.03-12 kGy by means of slightly different read-out procedure. The quantitative concept of ''indirect yield'', G{sub id}, was introduced for this procedure as a measure of the indirect oxidation capacity of the radicals. It was found to be G{sub id,0}(Fe{sup 3+}) 7.1 ions/100 eV transferred into the alanine. The spectrophotometric readout combines the highly advantageous use of alanine as a dosemeter with the straightforwardness, accuracy and low costs of the chemical procedure. (author).

  18. Alanine dosimetry using a spectrophotometric ferric-xylenol orange complex readout

    International Nuclear Information System (INIS)

    The spectrophotometric dosimetric method using the indirect oxidation of ferrous ions after dissolution of irradiated DL-and L-alanine has been thoroughly investigated with respect to its composition, read-out procedure and dose-response. Optimal concentration of 0.10 N H2SO4, 0.2 mM xylenol orange and 0.2 mM Fe2+ were found, giving an absorption maximum at 547 nm. Standardization of chemical processing procedures allows a reproducibility better than 0.5%. The useful dose range has been extended to 0.03-12 kGy by means of slightly different read-out procedure. The quantitative concept of ''indirect yield'', Gid, was introduced for this procedure as a measure of the indirect oxidation capacity of the radicals. It was found to be Gid,0(Fe3+) 7.1 ions/100 eV transferred into the alanine. The spectrophotometric readout combines the highly advantageous use of alanine as a dosemeter with the straightforwardness, accuracy and low costs of the chemical procedure. (author)

  19. Superconducting racetrack booster for the ion complex of MEIC

    Science.gov (United States)

    Filatov, Yu; Kondratenko, A. M.; Kondratenko, M. A.; Kovalenko, A.; Derbenev, Ya S.; Lin, F.; Morozov, V. S.; Zhang, Y.

    2016-02-01

    The current design of the Medium-energy Electron-Ion Collider (MEIC) project at Jefferson lab features a single 8 GeV/c figure-8 booster based on super-ferric magnets. Reducing the circumference of the booster by switching to a racetrack design may improve its performance by limiting the space charge effect and lower its cost. We consider problems of preserving proton and deuteron polarizations in a superconducting racetrack booster. We show that using magnets based on hollow high-current NbTi composite superconducting cable similar to those designed at JINR for the Nuclotron guarantees preservation of the ion polarization in a racetrack booster up to 8 GeV/c. The booster operation cycle would be a few seconds that would improve the operating efficiency of the MEIC ion complex.

  20. Use of a liquid-phase ion gun for local breakdown of the passive film on iron

    Energy Technology Data Exchange (ETDEWEB)

    Fushimi, Koji; Azumi, Kazuhisa; Seo, Masahiro

    2000-02-01

    A silver/silver chloride microelectrode was developed as a liquid-phase ion gun for investigation of precursor processes of pitting corrosion. This electrode was set as a probe electrode of a scanning electrochemical microscope and used to induce a local breakdown of passive film on iron. A small amount of chloride ions generated by cathodic polarization of the silver/silver chloride microelectrode has succeeded in inducing the local breakdown of the passive film formed on iron in deaerated pH 6.5 borate solution. Moreover, the microelectrode could detect ferric ions dissolved from the film at the initial stage of the film breakdown.

  1. Bacterial contamination of enteral diets.

    OpenAIRE

    de Leeuw, I H; Vandewoude, M F

    1986-01-01

    Enteral feeding solutions can be contaminated by bacterial micro-organisms already present in the ingredients, or introduced during preparation or transport, or in the hospital ward. During jejunostomy feeding without pump or filter, ascending bacterial invasion of the feeding bag is possible. In patients with lowered immune response contaminated feedings can cause serious septic clinical problems. The progressive loss of the nutritional value of the enteral feeding solution by bacterial cont...

  2. Transport powered by bacterial turbulence

    OpenAIRE

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-01-01

    We demonstrate that collective turbulent-like motion in a bacterial bath can power and steer directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedge-like "bulldozer" draws energy from a bacterial bath of varied density. We obtain that a maximal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp regi...

  3. Spontaneous bacterial peritonitis

    Institute of Scientific and Technical Information of China (English)

    Anastasios Koulaouzidis; Shivaram Bhat; Athar A Saeed

    2009-01-01

    Since its initial description in 1964, research has transformed spontaneous bacterial peritonitis (SBP) from a feared disease (with reported mortality of 90%) to a treatable complication of decompensated cirrhosis,albeit with steady prevalence and a high recurrence rate. Bacterial translocation, the key mechanism in the pathogenesis of SBP, is only possible because of the concurrent failure of defensive mechanisms in cirrhosis.Variants of SBP should be treated. Leucocyte esterase reagent strips have managed to shorten the 'tap-toshot' time, while future studies should look into their combined use with ascitic fluid pH. Third generation cephalosporins are the antibiotic of choice because they have a number of advantages. Renal dysfunction has been shown to be an independent predictor of mortality in patients with SBP. Albumin is felt to reduce the risk of renal impairment by improving effective intravascular volume, and by helping to bind proinflammatory molecules. Following a single episode of SBP, patients should have long-term antibiotic prophylaxis and be considered for liver transplantation.

  4. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M;

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...... susceptibility occurred in 21 (23%) of 92 cases of known aetiology, compared to an estimated 6% in nationally notified cases (p <0.001). Ceftriaxone plus penicillin as empirical treatment was appropriate in 97% of ABM cases in the study population, and in 99.6% of nationally notified cases. The notification rate...... was 75% for penicillin-susceptible episodes, and 24% for penicillin-non-susceptible episodes (p <0.001). Cases involving staphylococci, Pseudomonas spp. and Enterobacteriaceae were under-reported. Among 51 ABM cases with no identified risk factors, nine of 11 cases with penicillin...

  5. [Endogenous bacterial endophthalmitis].

    Science.gov (United States)

    Cornut, P-L; Chiquet, C

    2011-01-01

    Endogenous bacterial endophthalmitis, also called metastatic bacterial endophthalmitis, remains a diagnostic and therapeutic challenge. It is a rare and potentially sight-threatening ocular infection that occurs when bacteria reach the eye via the bloodstream, cross the blood-ocular barrier, and multiply within the eye. It usually affects immunocompromised patients and those suffering from diabetes mellitus, malignancy, or cardiac disease, but has also been reported after invasive procedures or in previously healthy people. In most cases, the ocular symptoms occur after the diagnosis of septicemia or systemic infection. Ocular symptoms include decreased vision, redness, discharge, pain, and floaters. The ocular inflammatory signs may be anterior and/or posterior. Bilateral involvement occurs in nearly 25% of cases. A wide range of microorganisms are involved, with differences in their frequency according to geography as well as the patient's age and past medical history, because of variations in the predisposing conditions and the source of the sepsis. The majority of patients are initially misdiagnosed, and ophthalmologists should be aware of this because prompt local and general management is required to save the eye and/or the patient's life. PMID:21145128

  6. Flexible magnetic membranes based on bacterial cellulose and its evaluation as electromagnetic interference shielding material

    International Nuclear Information System (INIS)

    Flexible magnetic membranes with high proportion of magnetite were successfully prepared by previous impregnation of the never dried bacterial cellulose pellicles with ferric chloride followed by reduction with sodium bisulfite and alkaline treatment for magnetite precipitation. Membranes were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating magnetometer, field emission scanning electron microscopy (FEG-SEM) and impedance spectroscopy. Microwave properties of these membranes were investigated in the X-band (8.2 to 12.4 GHz). FEG-SEM micrographs show an effective coverage of the BC nanofibers by Fe3O4 nanoparticles. Membranes with up to 75% in weight of particles have been prepared after 60 min of reaction. Magnetite nanoparticles in the form of aggregates well adhered to the BC fibers were observed by SEM. The average crystal sizes of the magnetic particles were in the range of 10 ± 1 to 13 ± 1 nm (estimated by XRD). The magnetic particles in the BC pellicles presented superparamagnetic behavior with a saturation magnetization in the range of 60 emu g−1 and coercive force around 15 Oe. These magnetic pellicles also displayed high electrical permittivity and a potential application as microwave absorber materials. - Highlights: • Bacterial cellulose/magnetite nanocomposites with high incorporation degree of nanoparticles. • Magnetite nanoparticles well adhered to the surface of bacterial cellulose nanofibers. • A saturation magnetization of the nanoparticles in the BC pellicles of about 60 emu g−1. • Flexible membranes with high super-paramagnetic characteristic

  7. Periodic growth of bacterial colonies

    Science.gov (United States)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  8. Conductivity and Dielectric Dispersion of Gram-Positive Bacterial Cells

    Science.gov (United States)

    van der Wal A; Minor; Norde; Zehnder; Lyklema

    1997-02-01

    The conductivity of bacterial cell suspensions has been studied over a wide range of ionic strengths and is interpreted in terms of their cell wall properties. The experimental data have been analyzed after improving the high kappaa double-layer theory of Fixman, by accounting for ionic mobility in the hydrodynamically stagnant layer, i.e., in the bacterial wall. Static conductivity and dielectric dispersion measurements both show that the counterions in the porous gel-like cell wall give rise to a considerable surface conductance. From a comparison of the mobile charge with the total cell wall charge it is inferred that the mobilities of the ions in the bacterial wall are of the same order but somewhat lower than those in the bulk electrolyte solution. The occurrence of surface conductance reduces the electrophoretic mobility in electrophoresis studies. If this effect is not taken into account, the zeta-potential will be underestimated, especially at low electrolyte concentrations. PMID:9056304

  9. [Small intestine bacterial overgrowth].

    Science.gov (United States)

    Leung Ki, E L; Roduit, J; Delarive, J; Guyot, J; Michetti, P; Dorta, G

    2010-01-27

    Small intestine bacterial overgrowth (SIBO) is a condition characterised by nutrient malabsorption and excessive bacteria in the small intestine. It typically presents with diarrhea, flatulence and a syndrome of malabsorption (steatorrhea, macrocytic anemia). However, it may be asymptomatic in the eldery. A high index of suspicion is necessary in order to differentiate SIBO from other similar presenting disorders such as coeliac disease, lactose intolerance or the irritable bowel syndrome. A search for predisposing factor is thus necessary. These factors may be anatomical (stenosis, blind loop), or functional (intestinal hypomotility, achlorydria). The hydrogen breath test is the most frequently used diagnostic test although it lacks standardisation. The treatment of SIBO consists of eliminating predisposing factors and broad-spectrum antibiotic therapy. PMID:20214190

  10. Studying bacterial multispecies biofilms

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...... the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the...... benefits and drawbacks of varying the degree of complexity. This review aims to facilitate multispecies biofilm research in order to expand the current limited knowledge on interspecies interactions. Recent technological advances have enabled total diversity analysis of highly complex and diverse microbial...

  11. Mechanics of torque generation in the bacterial flagellar motor

    CERN Document Server

    Mandadapu, Kranthi K; Berry, Richard M; Oster, George

    2015-01-01

    The bacterial flagellar motor (BFM) is responsible for driving bacterial locomotion and chemotaxis, fundamental processes in pathogenesis and biofilm formation. In the BFM, torque is generated at the interface between transmembrane proteins (stators) and a rotor. It is well-established that the passage of ions down a transmembrane gradient through the stator complex provides the energy needed for torque generation. However, the physics involved in this energy conversion remain poorly understood. Here we propose a mechanically specific model for torque generation in the BFM. In particular, we identify two fundamental forces involved in torque generation: electrostatic and steric. We propose that electrostatic forces serve to position the stator, while steric forces comprise the actual 'power stroke'. Specifically, we predict that ion-induced conformational changes about a proline 'hinge' residue in an $\\alpha$-helix of the stator are directly responsible for generating the power stroke. Our model predictions f...

  12. Electron transfer pathway analysis in bacterial photosynthetic reaction center

    CERN Document Server

    Kitoh-Nishioka, Hirotaka

    2016-01-01

    A new computational scheme to analyze electron transfer (ET) pathways in large biomolecules is presented with applications to ETs in bacterial photosynthetic reaction center. It consists of a linear combination of fragment molecular orbitals and an electron tunneling current analysis, which enables an efficient first-principles analysis of ET pathways in large biomolecules. The scheme has been applied to the ET from menaquinone to ubiquinone via nonheme iron complex in bacterial photosynthetic reaction center. It has revealed that not only the central Fe$^{2+}$ ion but also particular histidine ligands are involved in the ET pathways in such a way to mitigate perturbations that can be caused by metal ion substitution and depletion, which elucidates the experimentally observed insensitivity of the ET rate to these perturbations.

  13. Iron bioavailability in 8-24-month-old Thai children from a micronutrient-fortified quick-cooking rice containing ferric ammonium citrate or a mixture of ferrous sulphate and ferric sodium ethylenediaminetetraacetic acid.

    Science.gov (United States)

    Chavasit, Visith; Porasuphatana, Suparat; Suthutvoravut, Umaporn; Zeder, Christroph; Hurrell, Richard

    2015-12-01

    A quick-cooking rice, produced from broken rice, is a convenient ingredient for complementary foods in Thailand. The rice is fortified with micronutrients including iron during the processing procedure, which can cause unacceptable sensory changes. A quick-cooking rice fortified with ferric ammonium citrate (FAC) or a mixture of ferrous sulphate (FeSO4 ) and ferric sodium ethylenediaminetetraacetic acid (NaFeEDTA), with a 2:1 molar ratio of iron from FeSO4  : iron from NaFeEDTA (FeSO4  + NaFeEDTA), gave a product that was organoleptically acceptable. The study compared iron absorption by infants and young children fed with micronutrient-fortified quick-cooking rice containing the test iron compounds or FeSO4 . Micronutrient-fortified quick-cooking rice prepared as a traditional Thai dessert was fed to two groups of 15 8-24-month healthy Thai children. The iron fortificants were isotopically labelled with (57) Fe for the reference FeSO4 or (58) Fe for the tested fortificants, and iron absorption was quantified based on erythrocyte incorporation of the iron isotopes 14 days after feeding. The relative bioavailability of FAC and of the FeSO4  + NaFeEDTA was obtained by comparing their iron absorption with that of FeSO4 . Mean fractional iron absorption was 5.8% [±standard error (SE) 1.9] from FAC and 10.3% (±SE 1.9) from FeSO4  + NaFeEDTA. The relative bioavailability of FAC was 83% (P = 0.02). The relative bioavailability of FeSO4  + NaFeEDTA was 145% (P = 0.001). Iron absorption from the rice containing FAC or FeSO4  + NaFeEDTA was sufficiently high to be used in its formulation, although iron absorption from FeSO4  + NaFeEDTA was significantly higher (P < 0.00001). PMID:25721887

  14. K+ Block Is the Mechanism of Functional Asymmetry in Bacterial Na(v) Channels.

    Science.gov (United States)

    Ngo, Van; Wang, Yibo; Haas, Stephan; Noskov, Sergei Y; Farley, Robert A

    2016-01-01

    Crystal structures of several bacterial Na(v) channels have been recently published and molecular dynamics simulations of ion permeation through these channels are consistent with many electrophysiological properties of eukaryotic channels. Bacterial Na(v) channels have been characterized as functionally asymmetric, and the mechanism of this asymmetry has not been clearly understood. To address this question, we combined non-equilibrium simulation data with two-dimensional equilibrium unperturbed landscapes generated by umbrella sampling and Weighted Histogram Analysis Methods for multiple ions traversing the selectivity filter of bacterial Na(v)Ab channel. This approach provided new insight into the mechanism of selective ion permeation in bacterial Na(v) channels. The non-equilibrium simulations indicate that two or three extracellular K+ ions can block the entrance to the selectivity filter of Na(v)Ab in the presence of applied forces in the inward direction, but not in the outward direction. The block state occurs in an unstable local minimum of the equilibrium unperturbed free-energy landscape of two K+ ions that can be 'locked' in place by modest applied forces. In contrast to K+, three Na+ ions move favorably through the selectivity filter together as a unit in a loose "knock-on" mechanism of permeation in both inward and outward directions, and there is no similar local minimum in the two-dimensional free-energy landscape of two Na+ ions for a block state. The useful work predicted by the non-equilibrium simulations that is required to break the K+ block is equivalent to large applied potentials experimentally measured for two bacterial Na(v) channels to induce inward currents of K+ ions. These results illustrate how inclusion of non-equilibrium factors in the simulations can provide detailed information about mechanisms of ion selectivity that is missing from mechanisms derived from either crystal structures or equilibrium unperturbed free

  15. Molecular approaches for bacterial azoreductases

    Directory of Open Access Journals (Sweden)

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

  16. Channel-Forming Bacterial Toxins in Biosensing and Macromolecule Delivery

    OpenAIRE

    Gurnev, Philip A.; Nestorovich, Ekaterina M

    2014-01-01

    To intoxicate cells, pore-forming bacterial toxins are evolved to allow for the transmembrane traffic of different substrates, ranging from small inorganic ions to cell-specific polypeptides. Recent developments in single-channel electrical recordings, X-ray crystallography, protein engineering, and computational methods have generated a large body of knowledge about the basic principles of channel-mediated molecular transport. These discoveries provide a robust framework for expansion of t...

  17. Superiority of ferric chloride as coagulant over alum and ferrous sulphate at controlled pH and cost comparison of these coagulant

    International Nuclear Information System (INIS)

    This study was conducted by author as a member of Specialty Chemical Division of Sitara Chemical Industries which is the largest chlor -alkali manufacturing industry in Pakistan. Sitara is also producing FeCl/sub 3/ as a byproduct to consume its additional quantity of chlorine produced during electrolysis of brine solution for caustic soda preparation. Most of the industries are using Alum along with other polymers for treatment of effluent waste water. Treatment system is based on sand bed filters. For coagulation of unwanted materials present in the water, Alum is being used with Anionic Polymer (Accofloc-A2125) as flocculent. But the ferric chloride is not only functions as a reactants to remove water impurities but it also functions as a both coagulant and a Flocculent. This study was conducted for finding best alternative chemicals to improve treated water quality. For this purpose Ferric Chloride (FeCl/sub 3/) is used as best alternative of alum for better removal of turbidity, heavy metals and micro organisms to eradicate above said problems and for better removal of turbidity, heavy metals and micro, organisms to eradicate health problems. As per lab scale results quality of treated water with Ferric Chloride (FeCl/sub 3/) proved better than that of Alum. The main objective of this research is to investigate the efficiency of coagulation and flocculation processes for removing suspended solids, colour and COD which present in significant quantity. Three types of coagulants were examined using standard jar test apparatus, i.e., aluminum sulphate (alum), ferric chloride (FeCl/sub 3/) and ferrous sulphate (FeSO/sub 4/). The effects of agitation speed, settling time, pH, coagulant dosages and temperature were examined. At 300 rpm of rapid mixing and 50 rpm of slow mixing and 60 minutes settling time, higher removals of suspended solids (over 95%), colour (90%) and COD (43%) were achieved at pH 4 and 12. FeCl/sub 3/ was found to be superior compared with other

  18. Hard X-ray total scattering study on the structure of Si-dopped ferric oxyhydroxides and products of their transformation

    Science.gov (United States)

    Pieczara, Gabriela; Borkiewicz, Olaf; Manecki, Maciej; Rzepa, Grzegorz

    2016-04-01

    Here we report the results of a detailed structural investigation, using synchrotron-based pair distribution function analyses (PDF) and high-resolution X-ray diffraction (HR-XRD), on a series of Si-bearing synthetic analogues of ferrihydrite with a range of Si/Fe ratio relevant to geological environments and on products of their thermal transformation. Hard X-ray total scattering data suitable for PDF analyses have been collected at the PDF-dedicated beamline 11-ID-B and the HR-XRD data at beamline 11-BM of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). Ferrihydrite is a poorly crystalline, nano-sized hydrous ferric oxyhydroxide with a nominal/ideal formula Fe5HO8•4H2O. Its chemical composition however, can vary significantly and the atomic structure is yet to be fully understood despite multitude of structural studies undertaken over the past two decades (Michel et al., 2007; Manceau, 2009). One of the most commonly discussed and still unsettled contention points regarding the structural arrangements of ferrihydrite is related to the presence or absence of tetraherdally coordinated iron(III) within its structure. The majority of experimental work carried out to date focused on pure, synthetic ferrihydrite analogues with chemical composition close to ideal/nominal. This approach is clearly a significant oversimplification of natural ferrihydrite which always contains substantial amounts of admixtures, with Si, C, P, As, Ca, S and Al being the most common. One of the most important and the most commonly encountered impurities is Si, in the form of silicate ion that has strong affinity for ferrihydrite. SiO2content in natural ferrihydrites can vary substantially but generally falls with the range of 2.6-31.5 wt% (Cismasu et al., 2011). In certain environments however, such as modern seafloor hydrothermal vents, higher Si/Fe ratios (up to ca. 3) have been reported (Sun et al., 2013). The results of previous reports indicate that silicate

  19. High Affinity Binding of Indium and Ruthenium Ions by Gastrins.

    Directory of Open Access Journals (Sweden)

    Graham S Baldwin

    Full Text Available The peptide hormone gastrin binds two ferric ions with high affinity, and iron binding is essential for the biological activity of non-amidated forms of the hormone. Since gastrins act as growth factors in gastrointestinal cancers, and as peptides labelled with Ga and In isotopes are increasingly used for cancer diagnosis, the ability of gastrins to bind other metal ions was investigated systematically by absorption spectroscopy. The coordination structures of the complexes were characterized by extended X-ray absorption fine structure (EXAFS spectroscopy. Changes in the absorption of gastrin in the presence of increasing concentrations of Ga3+ were fitted by a 2 site model with dissociation constants (Kd of 3.3 x 10-7 and 1.1 x 10-6 M. Although the absorption of gastrin did not change upon the addition of In3+ ions, the changes in absorbance on Fe3+ ion binding in the presence of indium ions were fitted by a 2 site model with Kd values for In3+ of 6.5 x 10-15 and 1.7 x 10-7 M. Similar results were obtained with Ru3+ ions, although the Kd values for Ru3+ of 2.6 x 10-13 and 1.2 x 10-5 M were slightly larger than observed for In3+. The structures determined by EXAFS all had metal:gastrin stoichiometries of 2:1 but, while the metal ions in the Fe, Ga and In complexes were bridged by a carboxylate and an oxygen with a metal-metal separation of 3.0-3.3 Å, the Ru complex clearly demonstrated a short range Ru-Ru separation, which was significantly shorter, at 2.4 Å, indicative of a metal-metal bond. We conclude that gastrin selectively binds two In3+ or Ru3+ ions, and that the affinity of the first site for In3+ or Ru3+ ions is higher than for ferric ions. Some of the metal ion-gastrin complexes may be useful for cancer diagnosis and therapy.

  20. Ion Colliders

    CERN Document Server

    Fischer, W

    2014-01-01

    High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

  1. Sputtered Gum metal thin films showing bacterial inactivation and biocompatibility.

    Science.gov (United States)

    Achache, S; Alhussein, A; Lamri, S; François, M; Sanchette, F; Pulgarin, C; Kiwi, J; Rtimi, S

    2016-10-01

    Super-elastic Titanium based thin films Ti-23Nb-0.7Ta-2Zr-(O) (TNTZ-O) and Ti-24Nb-(N) (TN-N) (at.%) were deposited by direct current magnetron sputtering (DCMS) in different reactive atmospheres. The effects of oxygen doping (TNTZ-O) and/or nitrogen doping (TN-N) on the microstructure, mechanical properties and biocompatibility of the as-deposited coatings were investigated. Nano-indentation measurements show that, in both cases, 1sccm of reactive gas in the mixture is necessary to reach acceptable values of hardness and Young's modulus. Mechanical properties are considered in relation to the films compactness, the compressive stress and the changes in the grain size. Data on Bacterial inactivation and biocompatibility are reported in this study. The biocompatibility tests showed that O-containing samples led to higher cells proliferation. Bacterial inactivation was concomitant with the observed pH and surface potential changes under light and in the dark. The increased cell fluidity leading to bacterial lysis was followed during the bacterial inactivation time. The increasing cell wall fluidity was attributed to the damage of the bacterial outer cell which losing its capacity to regulate the ions exchange in and out of the bacteria. PMID:27434155

  2. Evolution of Bacterial Suicide

    Science.gov (United States)

    Tchernookov, Martin; Nemenman, Ilya

    2013-03-01

    While active, controlled cellular suicide (autolysis) in bacteria is commonly observed, it has been hard to argue that autolysis can be beneficial to an individual who commits it. We propose a theoretical model that predicts that bacterial autolysis is evolutionarily advantageous to an individualand would fixate in physically structured environments for stationary phase colonies. We perform spatially resolved agent-based simulations of the model, which predict that lower mixing in the environment results in fixation of a higher autolysis rate from a single mutated cell, regardless of the colony's genetic diversity. We argue that quorum sensing will fixate as well, even if initially rare, if it is coupled to controlling the autolysis rate. The model does not predict a strong additional competitive advantage for cells where autolysis is controlled by quorum sensing systems that distinguish self from nonself. These predictions are broadly supported by recent experimental results in B. subtilisand S. pneumoniae. Research partially supported by the James S McDonnell Foundation grant No. 220020321 and by HFSP grant No. RGY0084/2011.

  3. The rare bacterial biosphere.

    Science.gov (United States)

    Pedrós-Alió, Carlos

    2012-01-01

    All communities are dominated by a few species that account for most of the biomass and carbon cycling. On the other hand, a large number of species are represented by only a few individuals. In the case of bacteria, these rare species were until recently invisible. Owing to their low numbers, conventional molecular techniques could not retrieve them. Isolation in pure culture was the only way to identify some of them, but current culturing techniques are unable to isolate most of the bacteria in nature. The recent development of fast and cheap high-throughput sequencing has begun to allow access to the rare species. In the case of bacteria, the exploration of this rare biosphere has several points of interest. First, it will eventually produce a reasonable estimate of the total number of bacterial taxa in the oceans; right now, we do not even know the right order of magnitude. Second, it will answer the question of whether "everything is everywhere." Third, it will require hypothesizing and testing the ecological mechanisms that allow subsistence of many species in low numbers. And fourth, it will open an avenue of research into the immense reserve of genes with potential applications hidden in the rare biosphere. PMID:22457983

  4. 高铁铝土矿铝铁分离研究现状%Research Status of Separation of Aluminum and Iron from High-ferric Bauxite

    Institute of Scientific and Technical Information of China (English)

    许斌; 李帅军

    2014-01-01

    介绍了我国高铁铝土矿的资源储量和分布。根据国内外对高铁铝土矿铝铁分离开展的研究,论述了选矿法、磁化焙烧法、直接还原法、拜耳法、酸法等工艺的研究现状。%This paper introduces the reserves and distribution of high-ferric bauxite in our country and discusses research status of several processes including mineral processing method, magnetization roasting method, direct reduction method, bayer method,acid method and etc based on the research of aluminum and iron separation from high-ferric bauxite conducted home and abroad.

  5. Transport Powered by Bacterial Turbulence

    Science.gov (United States)

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-04-01

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations.

  6. Transport powered by bacterial turbulence.

    Science.gov (United States)

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S

    2014-04-18

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations. PMID:24785075

  7. Novel approach to zinc removal from circum-neutral mine waters using pelletised recovered hydrous ferric oxide.

    Science.gov (United States)

    Mayes, William M; Potter, Hugh A B; Jarvis, Adam P

    2009-02-15

    Data are presented which evaluate the performance of a pilot-scale treatment system using pelletised hydrous ferric oxide (HFO; a waste stream from coal mine water treatment) as a high surface area sorbent for removing zinc (Zn) from a metal mine water discharge in the North Pennines Orefield, UK. Over a 10-month period the system removed Zn at mean area- and volume-adjusted removal rates of 3.7 and 8.1gm(-3)day(-1), respectively, with a mean treatment efficiency of 32% at a low mean residence time of 49min. There were seasonal effects in Zn removal owing to establishment and dieback of algae in the treatment tank. This led to increased Zn uptake in early summer months followed by slight Zn release upon algae senescence. In addition to these biosorptive processes, the principal sinks for Zn appear to be (1) sorption onto the HFO surface, and (2) precipitation with calcite-dominated secondary minerals. The latter were formed as a product of dissolution of portlandite in the cement binder and calcium recarbonation. Further optimisation of the HFO pelletisation process holds the possibility for providing a low-cost, low footprint treatment option for metal rich mine waters, in addition to a valuable after-use for recovered HFO from coal mine water treatment facilities. PMID:18583040

  8. Distance determination between low-spin ferric haem and nitroxide spin label using DEER: the neuroglobin case

    Science.gov (United States)

    Ezhevskaya, M.; Bordignon, E.; Polyhach, Y.; Moens, L.; Dewilde, S.; Jeschke, G.; Van Doorslaer, S.

    2013-10-01

    This work demonstrates for the first time the feasibility of using double electron-electron resonance (DEER) to determine the inter-spin distance between nitroxide spin labels and low-spin (S = 1/2) ferric haem centres. For these means, two human neuroglobin variants were spin labelled leading to singly labelled haem proteins with the nitroxide label on one of the natural Cys residues (Cys55 or Cys120). Room-temperature electron paramagnetic resonance was used to characterise the mobility of the nitroxide labels and X- and Q-band DEER experiments were performed to detect nitroxide-haem distances. Effects of residual nuclear modulations in the DEER traces were carefully evaluated. The DEER-derived distances were compared with theoretical predictions from an X-ray diffraction structure of human neuroglobin using a rotamer library approach as well as with distance information obtained from electron relaxation measurements. The structural biological implications of the spin-labelled side chains' dynamics and of the obtained distances are also discussed.

  9. Fast Release of Sulfosalicylic Acid from Polymer Implants Consisting of Regenerated Cellulose/γ-Ferric Oxide/Polypyrrole

    Directory of Open Access Journals (Sweden)

    Nargis A. Chowdhury

    2014-01-01

    Full Text Available This work presents a comparative study on the rate of drug release from implantable matrices induced by electric and magnetic fields separately for better biomedical applications. The matrices were prepared by coating γ-ferric oxide dispersed regenerated cellulose film by polypyrrole doped with sulfosalicylic acid as an anti-inflammatory drug. The drug release mechanisms were studied under both the electric and the magnetic fields separately in an acetate buffer solution with pH 5.5 and temperature 37°C during a period of 5 hours. The amount of drug released was analysed by UV-Vis spectrophotometry. The mechanism of drug release from the matrices under electric field includes expansion of conductive polymer chain and the electrostatic force between electron and drug. The drug release mechanism from the matrices under magnetic field is based on the fact that the heat produced locally by magnetic particles loosens the polymer (polypyrrole chain surrounding the particles. As a result, the drugs attached to the polypyrrole chain come out to the release medium. The matrices showed fast release of drug, that is, more than 60% of the loaded drug was released within 1 h, and are ideal for the treatment of illness in an emergency care.

  10. Non-transferrin-bound iron (NTBI uptake by T lymphocytes: evidence for the selective acquisition of oligomeric ferric citrate species.

    Directory of Open Access Journals (Sweden)

    Joao Arezes

    Full Text Available Iron is an essential nutrient in several biological processes such as oxygen transport, DNA replication and erythropoiesis. Plasma iron normally circulates bound to transferrin. In iron overload disorders, however, iron concentrations exceed transferrin binding capacity and iron appears complexed with low molecular weight molecules, known as non-transferrin-bound iron (NTBI. NTBI is responsible for the toxicity associated with iron-overload pathologies but the mechanisms leading to NTBI uptake are not fully understood. Here we show for the first time that T lymphocytes are able to take up and accumulate NTBI in a manner that resembles that of hepatocytes. Moreover, we show that both hepatocytes and T lymphocytes take up the oligomeric Fe3Cit3 preferentially to other iron-citrate species, suggesting the existence of a selective NTBI carrier. These results provide a tool for the identification of the still elusive ferric-citrate cellular carrier and may also open a new pathway towards the design of more efficient iron chelators for the treatment of iron overload disorders.

  11. Core–shell structure carbon coated ferric oxide (Fe2O3@C) nanoparticles for supercapacitors with superior electrochemical performance

    International Nuclear Information System (INIS)

    Highlights: • Fe2O3@C was prepared by using arc discharge method followed by heat treatment. • KOH activation made the core–shell structure Fe2O3@C porous. • The activated-Fe2O3@C supercapacitor exhibited superior electrochemical performance. - Abstract: Core–shell structure carbon coated ferric oxide nanoparticles (Fe2O3@C) were fabricated by the oxidation of carbon coated iron nanoparticles (Fe@C) prepared by a direct current carbon arc discharge method. Porous activated-Fe2O3@C was prepared by KOH activation of Fe2O3@C at the temperature of 750 °C. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to characterize the structure and morphology of the Fe2O3@C and activated-Fe2O3@C. The specific surface area and pore size distribution of the samples were also tested. The activated-Fe2O3@C electrodes exhibited good electrochemical performance with a maximum specific capacitance of 612 F g−1 at the charge/discharge current density of 0.5 A g−1 with 5 M NaOH electrolyte. After 10,000 cycling DC tests at the charge/discharge current density of 4 A g−1, a high level specific capacitance of 518 F g−1 was obtained (90.6% retention of the initial capacity), suggesting excellent long-term cycling stability

  12. Effect of Ferric Chloride on the Properties of Biological Sludge in Co-precipitation Phosphorus Removal Process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhibin; LI Yi; WEI Leilei; L(U) Yufeng; WANG Meng; GAO Baoyu

    2013-01-01

    This paper studied the effect of ferric chloride on waste sludge digestion,dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process.The experimental results showed that the concentration of mixed liquid suspended solid (MLSS) was 2436 mg·L-1 and 2385 mg·L-1 in co-precipitation phosphorus removal process (CPR) and biological phosphorous removal process (BPR),respectively.The sludge reduction ratio for each process was 22.6% and 24.6% in aerobic digestion,and 27.6% and 29.9% in anaerobic digestion,respectively.Due to the addition of chemical to the end of aeration tank,the sludge content of CPR was slightly higher than that of BPR,but the sludge reduction rate for both processes had no distinct difference.The sludge volume index (SVI) and sludge specific resistance of BPR were 126 ml·g-1 and 11.7×1012 m·kg-1,respectively,while those of CPR were only 98 ml·g-1 and 7.1×1012 m·kg-1,indicating that CPR chemical could improve sludge settling and dewatering.

  13. Dragon Fruit Foliage Plant-Based Coagulant for Treatment of Concentrated Latex Effluent: Comparison of Treatment with Ferric Sulfate

    Directory of Open Access Journals (Sweden)

    Juferi Idris

    2013-01-01

    Full Text Available The effectiveness of dragon fruit foliage as a natural coagulant for treatment of concentrated latex effluent was investigated and compared with ferric sulfate, a chemical coagulant. Dragon fruit is a round and often red-colored fruit with scales-like texture and is native to south American countries which is also cultivated and heavily marketed in southeast Asian countries. Its foliage represents a part of its overall plant system. Latex effluent is one of the main byproduct from rubber processing factories in Malaysia. Three main parameters investigated were chemical oxygen demand (COD, suspended solids (SS, and turbidity of effluent. Coagulation experiments using jar test were performed with a flocculation system where the effects of latex effluent pH as well as coagulation dosage on coagulation effectiveness were examined. The highest recorded COD, SS, and turbidity removal percentages for foliage were observed for effluent pH 10 at 94.7, 88.9, and 99.7%, respectively. It is concluded that the foliage showed tremendous potential as a natural coagulant for water treatment purposes. The foliage could be used in the pretreatment stage of Malaysian latex effluent prior to secondary treatment.

  14. Effects of three additives on the removal of perfluorooctane sulfonate (PFOS) by coagulation using ferric chloride or aluminum sulfate.

    Science.gov (United States)

    Kishimoto, Naoyuki; Kobayashi, Masanori

    2016-01-01

    Perfluorooctanesulfonic acid and its salts (PFOS) are emerging contaminants with long half-lives in water and human bodies. Accordingly, PFOS removal from water streams is required for controlling the PFOS pollution. To provide a simple PFOS separation technology, effects of three additives, powdered activated carbon (PAC), gelatin, and cetyltrimethylammonium bromide (CTAB), on the PFOS removal by coagulation with ferric chloride or aluminum sulfate were investigated in this study. As a result, coagulation with PAC or CTAB addition was effective in the PFOS removal, though the conventional coagulation and coagulation with gelatin addition were ineffective. A PFOS removal efficiency of over 90% was observed for the CTAB dose of over 1.6 μM (0.58 mg/L) and for the PAC dose of over 40 mg/L, and that of over 95% was achieved by the CTAB dose of over 2.4 μM (0.87 mg/L), when the initial PFOS concentration was 1.84 μM. The positive effect of CTAB would be caused by micelle formation, which was enhanced by both the association of hydrophobic tails and the electrostatic attraction of hydrophilic heads of PFOS and CTAB. Thus, a linear cationic surfactant of CTAB was concluded to be an effective additive for the PFOS removal by coagulation. PMID:27332843

  15. Bacterial signaling and motility: Sure bets

    Energy Technology Data Exchange (ETDEWEB)

    Zhulin, Igor B [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)

    2008-01-01

    cytoplasmic membrane. The interaction causes the supramembrane and cytoplasmic rings to rotate along with the flagellar filaments. The energy for flagellar rotation comes from proton motive force or other ions, especially sodium in marine bacteria, which generate an electrochemical gradient across the cell membrane. Three proteins, FliM, FliN, and FliG, located at the base of the motor act as switches that control the direction of flagellar rotation. As exemplified by the enteric bacteria Escherichia coli and Salmonella enterica serovar Typhimurium, changes in the direction of flagellar rotation affect the swimming behavior of the bacterial cell. Counterclockwise (CCW) rotation of the flagella causes the flagellar filaments to form a bundle that pushes the cell forward in a 'run.' In contrast, clockwise (CW) rotation causes the flagellar bundle to fly apart, and the cell tumbles to reorient to a new direction for the ensuing run upon the return of CCW rotation. The interchanging pattern of CCW and CW rotations produces a random walk, composed of relatively long runs with occasional direction changes or turns. By modulating the lengths of the runs or the frequency of tumbling, bacteria can regulate their motile behavior to move in a desirable direction. Many bacteria can also move on surfaces. Except for flagellum-driven swarming motility, all the other forms of known bacterial surface movement involve no flagella. The flagellum-independent surface motility, known as gliding, is observed in cyanobacteria, Mycoplasma species, Cytophaga-Flexibacterium species, and Myxococcus species. Without a doubt, the most thoroughly studied model gliding bacterium is Myxococcus xanthus, which also serves as a prokaryotic model for developmental biology due to its ability to develop multicellular fruiting bodies. M. xanthus cells use gliding motility both to hunt for food during vegetative growth and to aggregate during fruiting body formation. When nutrients are present, groups of

  16. Ferric Citrate, an Iron-Based Phosphate Binder, Reduces Health Care Costs in Patients on Dialysis Based on Randomized Clinical Trial Data

    OpenAIRE

    Rodby, Roger A.; Umanath, Kausik; Niecestro, Robert; Christopher Bond, T.; Sika, Mohammed; Lewis, Julia; Dwyer, Jamie P.; . .

    2015-01-01

    Background Patients with end-stage renal disease (ESRD) require phosphate binders for hyperphosphatemia and erythropoiesis-stimulating agents (ESAs) and intravenous (IV) iron for anemia. Ferric citrate (FC) is a novel, iron-based phosphate binder that increases iron stores and decreases IV iron and ESA usage while maintaining hemoglobin levels, and may decrease the cost of ESRD care. The study objectives were to (1) quantify differences in ESA and IV iron usage among ESRD patients receiving F...

  17. Use of ferric sulfate: acid media for the desulfurization of model compounds of coal. [Dibenzothiophene, diphenyl sulfide, di-n-butyl sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Clary, L.R.; Vermeulen, T.; Lynn, S.

    1980-12-01

    The objective of this work has been to investigate the ability of ferric sulfate-acid leach systems to oxidize the sulfur in model compounds of coal. Ferric iron-acid leach systems have been shown to be quite effective at removal of inorganic sulfur in coal. In this study, the oxidative effect of ferric iron in acid-leach systems was studied using dibenzothiophene, diphenyl sulfide, and di-n-butyl sulfide as models of organic sulfur groups in coal. Nitrogen and oxygen, as well as various transition metal catalysts and oxidants, were utilized in this investigation. Dibenzothiophene was found to be quite refractory to oxidation, except in the case where metavanadate was added, where it appears that 40% oxidation to sulfone could have occurred per hour at 150/sup 0/C and mild oxygen pressure. Diphenyl sulfide was selectively oxidized to sulfoxide and sulfone in an iron and oxygen system. Approximately 15% conversion to sulfone occurred per hour under these conditions. Some of the di-n-butyl sulfide was cracked to 1-butene and 1-butanethiol under similar conditions. Zinc chloride and ferric iron were used at 200/sup 0/C in an attempt to desulfonate dibenzothiophene sulfone, diphenyl sulfone, and di-n-butyl sulfone. Di-n-butyl sulfone was completely desulfurized on one hour and fragmented to oxidized parafins, while dibenzothiophene sulfone and diphenyl sulfone were unaffected. These results suggest that an iron-acid leach process could only selectively oxidize aryl sulfides under mild conditions, representing only 20% of the organic sulfur in coal (8% of the total sulfur). Removal through desulfonation once selective sulfur oxidation had occurred was only demonstrated for alkyl sulfones, with severe oxidation of the fragmented paraffins also occurring in one hour.

  18. Contribution to the study of nuclear waste slurry concentration. Tangential microfiltration on mineral membranes made of ferric hydroxide suspension in highly saline media

    International Nuclear Information System (INIS)

    In this thesis are presented first results on volume reduction of low and medium activity nuclear wastes by concentration of solid matter in suspension with a tangential microfiltration process. Physicochemistry and rheology of a ferric hydroxide suspension in nitrate medium are studied. Permeation laws and ultrafiltration membrane fouling show the formation of a solid deposit on the membrane surface and influence of operation parameters. A model of deposit erosion is presented to explain local phenomena during filtration

  19. Ion colliders

    International Nuclear Information System (INIS)

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions (77Asb1, 81Bou1). The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  20. Bacterial flora of sturgeon fingerling

    International Nuclear Information System (INIS)

    The study on microbial populations is a suitable tool to understand and apply control methods to improve the sanitary level of production in fish breeding and rearing centers, ensure health of sturgeon fingerlings at the time of their release into the rivers and also in the conversation and restoration of these valuable stocks in the Caspian Sea, Iran. A laboratory research based on Austin methods (Austin, B., Austin, D.A. 1993) was conducted for bacterial study on 3 sturgeon species naming A. persicus, A. stellatus and A. nudiventris during different growth stages. Bacterial flora of Acinetobacter, Moraxella, Aeromonas, Vibrio, Edwardsiella, Staphylococcus, Proteus, Yersinia, Pseudomonas and Plesiomonas were determined. The factors which may induce changes in bacterial populations during different stages of fife are the followings: quality of water in rearing ponds, different conditions for growth stages, suitable time for colonization of bacterial flora in rearing pond, water temperature increase in fingerlings size and feeding condition. (author)

  1. Bacterial Communities: Interactions to Scale

    Science.gov (United States)

    Stubbendieck, Reed M.; Vargas-Bautista, Carol; Straight, Paul D.

    2016-01-01

    In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities. PMID:27551280

  2. Interaction Study of Certain Dyes like Ferric oxide Red, Brilliant Blue and Soy Food Stuffs with Statins and Its Influence on Protein Binding and Intrinsic Association Constant ‘K’ of Statins

    OpenAIRE

    Vijayaraj S; Bagyalakshmi J; Ravi TK

    2010-01-01

    Interaction of Atorvastatin, Simvastatin and Rosuvastatin with dyes like ferric oxide red, brilliant blue and soy food stuffs were carried out in BSA using RP-HPLC method. Developed method was validated as per ICH Guidelines. Protein binding and Intrinsic association constant ‘K’ of statin drugs were calculated in presence of dyes and food stuffs. The order of interaction in Atorvastatin, Simvastatin and Rosuvastatin were found to be ferric oxide > soy food stuffs > brilliant blue; Soy food s...

  3. The Bacterial Microflora of Fish

    OpenAIRE

    Austin, B.

    2002-01-01

    The results of numerous studies indicate that fish possess bacterial populations on or in their skin, gills, digestive tract, and light-emitting organs. In addition, the internal organs (kidney, liver, and spleen) of healthy fish may contain bacteria, but there is debate on whether or not muscle is actually sterile. The numbers and taxonomic composition of the bacterial populations often reflect those of the surrounding water. The role of the bacteria includes the ability to degrade complex m...

  4. Bacterial cellulose/boehmite composites

    Energy Technology Data Exchange (ETDEWEB)

    Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L. [Universidade Estadual Paulista Julio de Mesquita Filho. UNESP. Instituto de Quimica de Araraquara, SP (Brazil); Caiut, Jose Mauricio A. [Universidade de Sao Paulo. Departamento de Quimica - FFCLRP/USP, Ribeirao Preto, SP (Brazil)

    2011-07-01

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  5. Bacterial Culture of Neonatal Sepsis

    OpenAIRE

    AH Movahedian; R Moniri; Z Mosayebi

    2006-01-01

    Neonatal bacterial sepsis is one of the major cause of morbidity and mortality in neonates. This retrospective study was performed to determine the incidence of bacterial sepsis with focus on Gram negative organisms in neonates admitted at Beheshti Hospital in Kashan, during a 3-yr period, from September 2002 to September 2005. Blood culture was performed on all neonates with risk factors or signs of suggestive sepsis. Blood samples were cultured using brain heart infusion (BHI) broth accordi...

  6. Bacterial Alkaloids Prevent Amoebal Predation.

    Science.gov (United States)

    Klapper, Martin; Götze, Sebastian; Barnett, Robert; Willing, Karsten; Stallforth, Pierre

    2016-07-25

    Bacterial defense mechanisms have evolved to protect bacteria against predation by nematodes, predatory bacteria, or amoebae. We identified novel bacterial alkaloids (pyreudiones A-D) that protect the producer, Pseudomonas fluorescens HKI0770, against amoebal predation. Isolation, structure elucidation, total synthesis, and a proposed biosynthetic pathway for these structures are presented. The generation of P. fluorescens gene-deletion mutants unable to produce pyreudiones rendered the bacterium edible to a variety of soil-dwelling amoebae. PMID:27294402

  7. Mast cells in bacterial infections

    OpenAIRE

    Rönnberg, Elin

    2014-01-01

    Mast cells are implicated in immunity towards bacterial infection, but the molecular mechanisms by which mast cells contribute to the host response are only partially understood. Previous studies have examined how mast cells react to purified bacterial cell wall components, such as peptidoglycan and lipopolysaccharide. To investigate how mast cells react to live bacteria we co-cultured mast cells and the gram-positive bacteria Streptococcus equi (S. equi) and Staphylococcus aureus (S. aureus)...

  8. Studies of Experimental Bacterial Translocation

    OpenAIRE

    Stenbäck, Anders

    2005-01-01

    One of the main obstacles to maintaining patients with short bowel syndrome on parenteral nutrition, or successfully transplanting these patients with a small bowel graft, is the many severe infections that occur. Evidence is accumulating that translocating bacteria from the patient’s bowel causes a significant part of these infections. In this thesis bacterial translocation is studied in a Thiry-Vella loop of defunctionalised small bowel in the rat. Bacterial translocation to the mesenteric ...

  9. Bacterial translocation: impact of probiotics

    OpenAIRE

    Jeppsson, Bengt; Mangell, Peter; Adawi, Diya; Molin, Göran

    2004-01-01

    There is a considerable amount of data in humans showing that patients who cannot take in nutrients enterally have more organ failure in the intensive care unit, a less favourable prognosis, and a higher frequency of septicaemia, in particular involving bacterial species from the intestinal tract. However, there is little evidence that this is connected with translocation of bacterial species in humans. Animal data more uniformly imply the existence of such a connection. The main focus of thi...

  10. Electrical spiking in bacterial biofilms

    OpenAIRE

    Masi, Elisa; Ciszak, Marzena; Santopolo, Luisa; Frascella, Arcangela; Giovannetti, Luciana; Marchi, Emmanuela; Viti, Carlo; Mancuso, Stefano

    2015-01-01

    In nature, biofilms are the most common form of bacterial growth. In biofilms, bacteria display coordinated behaviour to perform specific functions. Here, we investigated electrical signalling as a possible driver in biofilm sociobiology. Using a multi-electrode array system that enables high spatio-temporal resolution, we studied the electrical activity in two biofilm-forming strains and one non-biofilm-forming strain. The action potential rates monitored during biofilm-forming bacterial gro...

  11. Bacterial sex in dental plaque

    OpenAIRE

    Olsen, Ingar; Tribble, Gena D; Fiehn, Nils-Erik; Wang, Bing-Yan

    2013-01-01

    Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it a...

  12. Bacterial contamination of radiopharmaceutical preparations

    International Nuclear Information System (INIS)

    Examinations of the microflora of the air, personnel hands' skin, and surface of the equipment were performed in the Centre for Nuclear research, Libya. It is stated that bacterial contamination was maximal in winter and minimal in summer. The authors believe that human factor is the crucial in bacterial contamination. The microflora detected at the surfaces of equipment contains increased levels of radioresistent forms of bacteria. 8 refs.; 3 tabs

  13. Bacterial cellulose/boehmite composites

    International Nuclear Information System (INIS)

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  14. Meningitis bacteriana Bacterial meningitis

    Directory of Open Access Journals (Sweden)

    Ana Teresa Alvarado Guevara

    2006-03-01

    causales son virales lo cual conlleva a las diferentes sub-clasificaciones. También en ciertos casos puede ser ocasionada por hongos, bacterias atípicas, micobacterias y parásitos.In Costa Rica the bacterial meningitis had turn into a high-priority subject in which to monitoring epidemiologist. It had been talked about in the last months, to dice an increase in the attention is published of this subject, due to this phenomenon it becomes necessary to make a revision of topic. Meningitis is an inflammation of leptomeninges and colonization of the subarachnoid cerebrospinal fluid (LCR due to different agents, which produces meningeal symptoms (ex. migraine, neck rigidity, and photophobia and pleocytosis in LCR. De pending on the variables to take into account is possible to group it in different classifications, taking into account the time of evolution are possible to be divided in acute or chronic, to first with few hours or days of beginning of the symptoms, whereas the chronicle also presents a silence course but of the disease of approximately 4 weeks of instauration. There is a difference according to its etiologic agent; they can be infectious and non-infectious. Examples of common non-infectious causes include medications (ex, nonsteroidal anti-inflammatory drugs, and antibiotics and carcinomatosis. A classification exists as well according to the causal agent. The acute bacterial meningitis remarks a bacterial origin of the syndrome, which characterizes by the by an acute onset of meningeal symptoms and neutrophilic pleocytosis. Each one of the bacteriological agents, parasitic or fungus finishes by characterizing the different presentations of the clinical features (ex, meningocóccica meningitis, Cryptococcus meningitis. Finally, there is also the aseptic meningitis, denominated in this form because it’s nonpyogenic cellular response caused by many types of agents. The patients show an acute beginning of symptoms, fever and lymphocytic pleocytosis. After

  15. Fricke-agarose dosimeter gels: ion diffusion modelling and microdensitometry alternative to MRI

    International Nuclear Information System (INIS)

    Ferric ion diffusion is one of the main problems that still restrains the dosimetric application of Fricke-agarose gels. In this work, we model this process within finite length gel samples. The temporal evolution of the ion concentration as a function of the initial concentration is derived by solving Fick's second law in two dimensions with boundary reflections. The influence of ion concentration gradient, elapsed time, diffusion coefficient and spatial resolution is studied. Due to the main drawbacks of MRI for studying these systems, i.e. high cost and acquisition time often non-negligible compared to diffusion time, we also investigate the possibility of using a microdensitometer. The application of this technique for Fricke gel dosimetry is proposed here for the first time. The estimate of the ion diffusion coefficient is in a very agreement with those reported in literature

  16. Switching patients with non-dialysis chronic kidney disease from oral iron to intravenous ferric carboxymaltose: effects on erythropoiesis-stimulating agent requirements, costs, hemoglobin and iron status.

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Toblli

    Full Text Available Patients with non-dialysis-dependent chronic kidney disease (ND-CKD often receive an erythropoiesis-stimulating agent (ESA and oral iron treatment. This study evaluated whether a switch from oral iron to intravenous ferric carboxymaltose can reduce ESA requirements and improve iron status and hemoglobin in patients with ND-CKD.This prospective, single arm and single-center study included adult patients with ND-CKD (creatinine clearance ≤40 mL/min, hemoglobin 11-12 g/dL and iron deficiency (ferritin 20%. Outcome measures were ESA dose requirements during the observation period after initial ferric carboxymaltose treatment (primary endpoint; number of hospitalizations and transfusions, renal function before and after ferric carboxymaltose administration, number of adverse reactions (secondary endpoints. Hemoglobin, mean corpuscular volume, ferritin and transferrin saturation were measured monthly from baseline until end of study. Creatinine clearance, proteinuria, C-reactive protein, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase bimonthly from baseline until end of study.Thirty patients were enrolled (age 70.1±11.4 years; mean±SD. Mean ESA consumption was significantly reduced by 83.2±10.9% (from 41,839±3,668 IU/patient to 6,879±4,271 IU/patient; p<0.01. Hemoglobin increased by 0.7±0.3 g/dL, ferritin by 196.0±38.7 μg/L and transferrin saturation by 5.3±2.9% (month 6 vs. baseline; all p<0.01. No ferric carboxymaltose-related adverse events were reported and no patient withdrew or required transfusions during the study.Among patients with ND-CKD and stable normal or borderline hemoglobin, switching from oral iron to intravenous ferric carboxymaltose was associated with significant improvements in hematological and iron parameters and a significant reduction in ESA dose requirements in this single-center pilot study.ClinicalTrials.gov NCT02232906.

  17. Switching Patients with Non-Dialysis Chronic Kidney Disease from Oral Iron to Intravenous Ferric Carboxymaltose: Effects on Erythropoiesis-Stimulating Agent Requirements, Costs, Hemoglobin and Iron Status

    Science.gov (United States)

    Toblli, Jorge Eduardo; Di Gennaro, Federico

    2015-01-01

    Background Patients with non-dialysis-dependent chronic kidney disease (ND-CKD) often receive an erythropoiesis-stimulating agent (ESA) and oral iron treatment. This study evaluated whether a switch from oral iron to intravenous ferric carboxymaltose can reduce ESA requirements and improve iron status and hemoglobin in patients with ND-CKD. Methods This prospective, single arm and single-center study included adult patients with ND-CKD (creatinine clearance ≤40 mL/min), hemoglobin 11–12 g/dL and iron deficiency (ferritin 20%). Outcome measures were ESA dose requirements during the observation period after initial ferric carboxymaltose treatment (primary endpoint); number of hospitalizations and transfusions, renal function before and after ferric carboxymaltose administration, number of adverse reactions (secondary endpoints). Hemoglobin, mean corpuscular volume, ferritin and transferrin saturation were measured monthly from baseline until end of study. Creatinine clearance, proteinuria, C-reactive protein, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase bimonthly from baseline until end of study. Results Thirty patients were enrolled (age 70.1±11.4 years; mean±SD). Mean ESA consumption was significantly reduced by 83.2±10.9% (from 41,839±3,668 IU/patient to 6,879±4,271 IU/patient; p<0.01). Hemoglobin increased by 0.7±0.3 g/dL, ferritin by 196.0±38.7 μg/L and transferrin saturation by 5.3±2.9% (month 6 vs. baseline; all p<0.01). No ferric carboxymaltose-related adverse events were reported and no patient withdrew or required transfusions during the study. Conclusion Among patients with ND-CKD and stable normal or borderline hemoglobin, switching from oral iron to intravenous ferric carboxymaltose was associated with significant improvements in hematological and iron parameters and a significant reduction in ESA dose requirements in this single-center pilot study. Trial Registration ClinicalTrials.gov NCT02232906 PMID

  18. 7 CFR 58.135 - Bacterial estimate.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Bacterial estimate. 58.135 Section 58.135 Agriculture... Milk § 58.135 Bacterial estimate. (a) Methods of Testing. Milk shall be tested for bacterial estimate... of Testing. A laboratory examination to determine the bacterial estimate shall be made on...

  19. 高海拔地区难处理金精矿的细菌氧化预处理及氰化浸金%Bacterial Pre-oxidation of Refractory Gold Concentrate from the High Altitude Areas and Cyanidation Leaching of Gold

    Institute of Scientific and Technical Information of China (English)

    张祉倩; 刘升明; 李超; 李宏煦; 吴超

    2012-01-01

    Bacterial pre-oxidation of refractory gold ore from the high altitude areas was studied. The removal rates of Fe, S, As and cyanidation teaching rate of Au were examined under the different conditions. And the gold concentrate, oxidizing slag, and leaching residue were analyzed by XRD and SEM. The results indicated that the removal rates of Fe, S and As were up to 85% and the leaching rate of gold was 88.09%. Feasibility of bio-oxidation pretreatment in the high altitude areas was proved. Based on the experimental results, the bacterial oxidation mechanism of gold concentrates and acid solution neutralization were analyzed briefly. The bacterial oxidation of gold concentrate occurred under cooperative direct and indirect mechanism. Removal of the arsenic and heavy metal ions of liquid phase in the form of ferric arsenate and hydroxide precipitation was the main purpose of acid solution neutralization.%针对高海拔地区某难处理金精矿含砷高的特点,采用细菌氧化预处理工艺,考察在一定工艺条件下,Fe,S,As脱除率及金的氰化浸出率,并对金精矿及氧化渣、氰化渣进行了分析.结果表明,Fe,S,As脱除率均达85%以上,金氰化浸出率为88.09%,说明对该类矿物采用细菌氧化预处理工艺具有可行性.机理分析表明,细菌氧化金精矿是通过直接与间接协同作用机理;氧化酸液中和主要是将液相中砷以化学性质稳定的砷酸铁沉淀除去,将重金属离子等以氢氧化物沉淀去除.

  20. Ion Chromatography.

    Science.gov (United States)

    Mulik, James D.; Sawicki, Eugene

    1979-01-01

    Accurate for the analysis of ions in solution, this form of analysis enables the analyst to directly assay many compounds that previously were difficult or impossible to analyze. The method is a combination of the methodologies of ion exchange, liquid chromatography, and conductimetric determination with eluant suppression. (Author/RE)

  1. Hydrogen peroxide-independent generation of superoxide by plant peroxidase: Hypotheses and supportive data employing ferrous ion as a model stimulus

    OpenAIRE

    Makoto eKimura; Yosuke eUmemoto; Tomonori eKawano

    2014-01-01

    When plants are threaten by microbial attacks or treated with elicitors, alkalization of extracellular space is often induced and thus pH-dependent extracellular peroxidase-mediated oxidative burst reportedly takes place, especially at the site of microbial challenge. However, direct stimulus involved in activation of peroxidase-catalyzed oxidative burst has not been identified to date. Here, we would like to propose a likely role for free ferrous ion in reduction of ferric native peroxidase ...

  2. The Siderocalin/Enterobactin Interaction: A Link between Mammalian Immunity and Bacterial Iron Transport

    Energy Technology Data Exchange (ETDEWEB)

    Meux, Susan C.

    2008-05-12

    The siderophore enterobactin (Ent) is produced by enteric bacteria to mediate iron uptake. Ent scavenges iron and is taken up by the bacteria as the highly stable ferric complex [Fe{sup III}(Ent)]{sup 3-}. This complex is also a specific target of the mammalian innate immune system protein, Siderocalin (Scn), which acts as an anti-bacterial agent by specifically sequestering siderophores and their ferric complexes during infection. Recent literature suggesting that Scn may also be involved in cellular iron transport has increased the importance of understanding the mechanism of siderophore interception and clearance by Scn; Scn is observed to release iron in acidic endosomes and [Fe{sup III}(Ent)]{sup 3-} is known to undergo a change from catecholate to salicylate coordination in acidic conditions, which is predicted to be sterically incompatible with the Scn binding pocket (also referred to as the calyx). To investigate the interactions between the ferric Ent complex and Scn at different pH values, two recombinant forms of Scn with mutations in three residues lining the calyx were prepared: Scn-W79A/R81A and Scn-Y106F. Binding studies and crystal structures of the Scn-W79A/R81A:[Fe{sup III}(Ent)]{sup 3-} and Scn-Y106F:[Fe{sup III}(Ent)]{sup 3-} complexes confirm that such mutations do not affect the overall conformation of the protein but do weaken significantly its affinity for [Fe{sup III}(Ent)]{sup 3-}. Fluorescence, UV-Vis and EXAFS spectroscopies were used to determine Scn/siderophore dissociation constants and to characterize the coordination mode of iron over a wide pH range, in the presence of both mutant proteins and synthetic salicylate analogs of Ent. While Scn binding hinders salicylate coordination transformation, strong acidification results in the release of iron and degraded siderophore. Iron release may therefore result from a combination of Ent degradation and coordination change.

  3. Biosynthesis and structural characterization of silver nanoparticles from bacterial isolates

    International Nuclear Information System (INIS)

    Graphical abstract: In this study five bacterial isolates belong to different genera were found to be able to biosynthesize silver nanoparticles. Biosynthesis and spectral characterization are reported here. Highlights: → About 300 bacterial isolates were screened for their ability to produce nanosilvers → Five of them were potential candidates for synthesis of silver nanoparticles → Production of silver nanoparticles was examined using UV-Vis, XRD, SEM and EDS. → The presence of nanoparticles with all five bacterial isolates was confirmed. -- Abstract: This study aimed to develop a green process for biosynthesis of silver nanomaterials by some Egyptian bacterial isolates. This target was achieved by screening an in-house culture collection consists of 300 bacterial isolates for silver nanoparticle formation. Through screening process, it was observed that strains belonging to Escherichia coli (S30, S78), Bacillus megaterium (S52), Acinetobacter sp. (S7) and Stenotrophomonas maltophilia (S54) were potential candidates for synthesis of silver nanoparticles. The extracellular production of silver nanoparticles by positive isolates was investigated by UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results demonstrated that UV-visible spectrum of the aqueous medium containing silver ion showed a peak at 420 nm corresponding to the plasmon absorbance of silver nanoparticles. Scanning electron microscopy micrograph showed formation of silver nanoparticles in the range of 15-50 nm. XRD-spectrum of the silver nanoparticles exhibited 2θ values corresponding to the silver nanocrystal that produce in hexagonal and cubic crystal configurations with different plane of orientation. In addition, the signals of the silver atoms were observed by EDS-spectrum analysis that confirms the presence of silver nanoparticles (AgNPs) in all positive

  4. Biosynthesis and structural characterization of silver nanoparticles from bacterial isolates

    Energy Technology Data Exchange (ETDEWEB)

    Zaki, Sahar, E-mail: saharzaki@yahoo.com [Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria, 21934 New Burgelarab City (Egypt); El Kady, M.F. [Fabrication Technology Department, Advanced Technology and New Materials Research Institute (ATNMRI), Mubarak City for Scientific Research and Technology Applications, Alexandria (Egypt); Abd-El-Haleem, Desouky [Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research and Technology Applications, Alexandria, 21934 New Burgelarab City (Egypt)

    2011-10-15

    Graphical abstract: In this study five bacterial isolates belong to different genera were found to be able to biosynthesize silver nanoparticles. Biosynthesis and spectral characterization are reported here. Highlights: {yields} About 300 bacterial isolates were screened for their ability to produce nanosilvers {yields} Five of them were potential candidates for synthesis of silver nanoparticles {yields} Production of silver nanoparticles was examined using UV-Vis, XRD, SEM and EDS. {yields} The presence of nanoparticles with all five bacterial isolates was confirmed. -- Abstract: This study aimed to develop a green process for biosynthesis of silver nanomaterials by some Egyptian bacterial isolates. This target was achieved by screening an in-house culture collection consists of 300 bacterial isolates for silver nanoparticle formation. Through screening process, it was observed that strains belonging to Escherichia coli (S30, S78), Bacillus megaterium (S52), Acinetobacter sp. (S7) and Stenotrophomonas maltophilia (S54) were potential candidates for synthesis of silver nanoparticles. The extracellular production of silver nanoparticles by positive isolates was investigated by UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results demonstrated that UV-visible spectrum of the aqueous medium containing silver ion showed a peak at 420 nm corresponding to the plasmon absorbance of silver nanoparticles. Scanning electron microscopy micrograph showed formation of silver nanoparticles in the range of 15-50 nm. XRD-spectrum of the silver nanoparticles exhibited 2{theta} values corresponding to the silver nanocrystal that produce in hexagonal and cubic crystal configurations with different plane of orientation. In addition, the signals of the silver atoms were observed by EDS-spectrum analysis that confirms the presence of silver nanoparticles (Ag

  5. Arsenate Adsorption by Hydrous Ferric Oxide Nanoparticles Embedded in Cross-linked Anion Exchanger: Effect of the Host Pore Structure.

    Science.gov (United States)

    Li, Hongchao; Shan, Chao; Zhang, Yanyang; Cai, Jianguo; Zhang, Weiming; Pan, Bingcai

    2016-02-10

    Three composite adsorbents were fabricated via confined growth of hydrous ferric oxide (HFO) nanoparticles within cross-linked anion exchangers (NS) of different pore size distributions to investigate the effect of host pore structure on the adsorption of As(V). With the decrease in the average pore size of the NS hosts from 38.7 to 9.2 nm, the mean diameter of the confined HFO nanoparticles was lessened from 31.4 to 11.6 nm as observed by transmission electron microscopy (TEM), while the density of active surface sites was increased due to size-dependent effect proved by potentiometric titration. The adsorption capacity of As(V) yielded by Sips model was elevated from 24.2 to 31.6 mg/g via tailoring the pore size of the NS hosts, and the adsorption kinetics was slightly accelerated with the decrease of pore size in background solution containing 500 mg/L of Cl(-). Furthermore, the enhanced adsorption of As(V) was achieved over a wide pH range from 3 to 10, as well as in the presence of competing anions including Cl(-), SO4(2-), HCO3(-), NO3(-) (up to 800 mg/L), and PO4(3-) (up to 10 mg P/L). In addition, the fixed-bed working capacity increased from 2200 to 2950 bed volumes (BV) owing to the size confinement effect, which did not have adverse effect on the desorption of As(V) as the cumulative desorption efficiency reached 94% with 10 BV of binary solution (5% NaOH + 5% NaCl) for all the three adsorbents. Therefore, this study provided a promising strategy to regulate the reactivity of the nanoparticles via the size confinement effect of the host pore structure. PMID:26765396

  6. A universally calibrated microplate ferric reducing antioxidant power (FRAP) assay for foods and applications to Manuka honey.

    Science.gov (United States)

    Bolanos de la Torre, Amparo Angelica S; Henderson, Terence; Nigam, Poonam Singh; Owusu-Apenten, Richard K

    2015-05-01

    The ferric reducing antioxidant power (FRAP) assay was recently adapted to a microplate format. However, microplate-based FRAP (mFRAP) assays are affected by sample volume and composition. This work describes a calibration process for mFRAP assays which yields data free of volume effects. From the results, the molar absorptivity (ε) for the mFRAP assay was 141,698 M(-1) cm(-1) for gallic acid, 49,328 M(-1) cm(-1) for ascorbic acid, and 21,606 M(-1) cm(-1) for ammonium ferrous sulphate. The significance of ε (M(-1) cm(-1)) is discussed in relation to mFRAP assay sensitivity, minimum detectable concentration, and the dimensionless FRAP-value. Gallic acid showed 6.6 mol of Fe(2+) equivalents compared to 2.3 mol of Fe(+2) equivalents for ascorbic acid. Application of the mFRAP assay to Manuka honey samples (rated 5+, 10+, 15+, and 18+ Unique Manuka Factor; UMF) showed that FRAP values (0.54-0.76 mmol Fe(2+) per 100g honey) were strongly correlated with UMF ratings (R(2)=0.977) and total phenols content (R(2) = 0.982)whilst the UMF rating was correlated with the total phenols (R(2) = 0.999). In conclusion, mFRAP assay results were successfully standardised to yield data corresponding to 1-cm spectrophotometer which is useful for quality assurance purposes. The antioxidant capacity of Manuka honey was found to be directly related to the UMF rating. PMID:25529660

  7. Chemical, physical, and sensory characteristics of mozzarella cheese fortified using protein-chelated iron or ferric chloride.

    Science.gov (United States)

    Rice, W H; McMahon, D J

    1998-02-01

    Mozzarella cheese containing 25 and 50 mg of iron/kg of cheese was manufactured from milk that had been fortified with casein-chelated iron, whey protein-chelated iron, or FeCl3. Chemical, physical, and sensory characteristics were compared with those of a control cheese. Physical properties were assessed by testing melting, apparent viscosity, and browning of heated cheese. Cheeses were evaluated by trained panelists for the presence of metallic flavors, oxidized flavors, and other undesirable flavors. Addition of 25 mg iron/kg of cheese had no effects on the physical properties of Mozzarella cheese. Apparent viscosity of cheese fortified with 50 mg of iron/kg of cheese tended to be slightly higher than the control cheese, although this difference was not statistically significant at all storage times. Cook color was not affected by iron fortification. No increase in chemical oxidation (measured using thiobarbituric acid assay) was observed between the control and iron-fortified cheeses. Slight but statistically significant increases in metallic flavors, oxidized flavors, and off-flavors in the iron-fortified cheese were observed by the trained sensory panel, but the flavor defects were of very low intensity. For metallic flavors, oxidized flavors, and off-flavors, the control cheese scored 1.5, 1.5, and 1.3, respectively; the iron-fortified cheese scored 2.1, 2.0, and 1.6 based on a nine-point scale (where 1 = not perceptible to 3 = slightly perceptible). Sensory scores for iron-fortified cheese made using casein-chelated iron or whey protein-chelated iron was not significantly different from those of cheese made using ferric chloride. When used on pizza, consumer panels rated the iron-fortified cheeses as comparable with the control cheese. PMID:9532487

  8. Elasticity of Single-Crystal Phase D across the Spin Transitions of Ferrous and Ferric Iron in the Lower Mantle

    Science.gov (United States)

    Wu, X.; Lin, J. F.; Liu, J.; Mao, Z.; Guo, X.; Yoshino, T.; McCammon, C. A.; Xiao, Y.; Prakapenka, V.

    2014-12-01

    Phase D, the densest hydrous magnesium silicate synthesized at the Earth's mantle P-T conditions thus far, has been proposed to be a potential candidate for transportation of H2O into the lower mantle by subduction of the hydrated oceanic lithosphere. A certain amount of iron, the most abundant transition metal element in the Earth's interior, is expected to be incorporated into the phase D. Here we synthesized high-quality single-crystal Fe,Al-bearing Phase D (Mg0.89Fe0.11Al0.37Si1.55H2.65O6, ~13.3wt% H2O) with grain sizes of ~200 micron using the Kawai multianvil apparatus at 21 GPa and 1200 °C at the Institute for Study of the Earth's Interior, University of Oakayama, Japan. Conventional Mössbauer results indicate that the sample contains both ferrous and ferric iron that occupy the octahedral sites of the hexagonal structure. In situ high-pressure single crystal XRD and NFS experiments were performed up to megabar pressures at 13IDD beamline (GSECARS) and 16IDD beamline (HPCAT) of the Advanced Photon Source, respectively. Both experimental results clearly show that both Fe2+ and Fe3+ undergo a HS-LS transition at high pressures. High-resolution XRD results further indicate an abnormal compression behavior at approximately 37 GPa that can be linked with the previously proposed hydrogen bond symmetrization. Elasticity of phase D has a marked influence by the two-step spin transitions of both Fe2+ and Fe3+ and the hydrogen bond symmetrization, presenting in the seismic wave model, which is of implication for our understanding of the deep-Earth geophysics and geochemistry especially along the subducted slabs.

  9. Optical Study of Cuprous Oxide and Ferric Oxide Based Materials for Applications in Low Cost Solar Cells

    Science.gov (United States)

    Than, Thi Cuc; Bui, Bao Thoa; Wegmuller, Benjamin; Nguyen, Minh Hieu; Hoang Ngoc, Lam Huong; Bui, Van Diep; Nguyen, Quoc Hung; Hoang, Chi Hieu; Nguyen-Tran, Thuat

    2016-05-01

    One of the interesting forms of cuprous oxide and ferric oxide based materials is CuFeO2 which can be a delafossite-type compound and is a well known p-type semiconductor. This compound makes up an interesting family of materials for technological applications. CuFeO2 thin films recently gained renewed interest for potential applications in solar cell devices especially as absorption layers. One of the interesting facts is that CuFeO2 is made from cheap materials such as copper and iron. In this study, CuFeO2 thin films are intentionally deposited on corning glass and silicon substrates by the radio-frequency and direct current sputtering method with complicated and well developed co-sputtering recipes. The deposition was performed at room temperature which leads to an amorphous phase with extremely low roughness and high density. The films also were annealed at 500°C in 5% H2 in Ar for the passivation. A detailed optical study was performed on these thin films by spectroscopic ellipsometry and by ultra-violet visible near infrared spectroscopy. Depending on sputtering conditions, the direct band gap was extrapolated to be from 1.96 eV to 2.2 eV and 2.92 eV to 2.96 eV and the indirect band gap is about 1.22 eV to 1.42 eV. A good electrical conduction is also observed which is suitable for solar cell applications. In future more study on the structural properties will be carried out in order to fully understand these materials.

  10. Effects of suspended particles on the rate of mass transfer to a rotating disk electrode. [Ferric cyanide

    Energy Technology Data Exchange (ETDEWEB)

    Roha, D.J.

    1981-06-01

    Limiting currents for the reduction of ferric cyanide at a rotating disk were determined in the presence of 0 to 40 percent by volume of spherical glass beads. Experiments were conducted with six different particle diameters, and with rotation speeds in the range of 387 to 270 rpm, usong both a 0.56 cm and a 1.41 cm radius disk electrode. It was established that at a given rpm upon addition of glass beads in the limiting current, i/sub L/, may increase to more than three times its value without solids. This increase in limiting current density is greater at high rotation speeds and with the larger disk electrode. i/sub L/ as a function of particle diameter yields at maximum at approx. 10 ..mu..m. Two mass transfer models are offered to explain this behavior, both of which assume that the beads are in contact with the disk electrode and moving parallel to its surface. In the surface renewal model it is assumed that complete mixing takes place with the passage of each bead and the boundary layer is replaced with fresh bulk solution. While with the particle film model it is assumed the bead and a clinging film of fluid rotate together. The film promotes mass transfer by alternately absorbing and desorbing the diffusing species. The particle film model best explains the observed behavior of the limiting current density. Calculations of stirring power required verses i/sub L/ observed, show that adding beads to increase i/sub L/ consumes less additional power than simply increasing the rotation speed alone and even permits a decrease in the amount of stirring energy required per unit reactant consumed, at limiting current conditions.

  11. Microfluidic Approaches to Bacterial Biofilm Formation

    OpenAIRE

    Hee-Deung Park; Junghyun Kim; Seok Chung

    2012-01-01

    Bacterial biofilms—aggregations of bacterial cells and extracellular polymeric substrates (EPS)—are an important subject of research in the fields of biology and medical science. Under aquatic conditions, bacterial cells form biofilms as a mechanism for improving survival and dispersion. In this review, we discuss bacterial biofilm development as a structurally and dynamically complex biological system and propose microfluidic approaches for the study of bacterial biofilms. Biofilms develop t...

  12. The human vaginal bacterial biota and bacterial vaginosis.

    Science.gov (United States)

    Srinivasan, Sujatha; Fredricks, David N

    2008-01-01

    The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV). PCR methods have shown that women with BV have complex communities of vaginal bacteria that include many fastidious species, particularly from the phyla Bacteroidetes and Actinobacteria. Healthy women are mostly colonized with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners, though a variety of other bacteria may be present. The microbiology of BV is heterogeneous. The presence of Gardnerella vaginalis and Atopobium vaginae coating the vaginal epithelium in some subjects with BV suggests that biofilms may contribute to this condition. PMID:19282975

  13. Ion implantation

    International Nuclear Information System (INIS)

    It is the purpose of the present paper to give a review of surface alloy processing by ion implantation. However, rather than covering this vast subject as a whole, the survey is confined to a presentation of the microstructures that can be found in metal surfaces after ion implantation. The presentation is limited to alloys processed by ion implantation proper, that is to processes in which the alloy compositions are altered significantly by direct injection of the implanted ions. The review is introduced by a presentation of the processes taking place during development of the fundamental event in ion implantation - the collision cascade, followed by a summary of the various microstructures which can be formed after ion implantation into metals. This is compared with the variability of microstructures that can be achieved by rapid solidification processing. The microstructures are subsequently discussed in the light of the processes which, as the implantations proceed, take place during and immediately after formation of the individual collision cascades. These collision cascades define the volumes inside which individual ions are slowed down in the implanted targets. They are not only centres for vigorous agitation but also the sources for formation of excess concentrations of point defects, which will influence development of particular microstructures. A final section presents a selection of specific structures which have been observed in different alloy systems. (orig./GSCH)

  14. New Treatments for Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Raymond L. M. Wong

    2012-01-01

    Full Text Available Purpose. To review the newer treatments for bacterial keratitis. Data Sources. PubMed literature search up to April 2012. Study Selection. Key words used for literature search: “infectious keratitis”, “microbial keratitis”, “infective keratitis”, “new treatments for infectious keratitis”, “fourth generation fluoroquinolones”, “moxifloxacin”, “gatifloxacin”, “collagen cross-linking”, and “photodynamic therapy”. Data Extraction. Over 2400 articles were retrieved. Large scale studies or publications at more recent dates were selected. Data Synthesis. Broad spectrum antibiotics have been the main stay of treatment for bacterial keratitis but with the emergence of bacterial resistance; there is a need for newer antimicrobial agents and treatment methods. Fourth-generation fluoroquinolones and corneal collagen cross-linking are amongst the new treatments. In vitro studies and prospective clinical trials have shown that fourth-generation fluoroquinolones are better than the older generation fluoroquinolones and are as potent as combined fortified antibiotics against common pathogens that cause bacterial keratitis. Collagen cross-linking was shown to improve healing of infectious corneal ulcer in treatment-resistant cases or as an adjunct to antibiotics treatment. Conclusion. Fourth-generation fluoroquinolones are good alternatives to standard treatment of bacterial keratitis using combined fortified topical antibiotics. Collagen cross-linking may be considered in treatment-resistant infectious keratitis or as an adjunct to antibiotics therapy.

  15. Interfering with Bacterial Quorum Sensing.

    Science.gov (United States)

    Reuter, Kerstin; Steinbach, Anke; Helms, Volkhard

    2016-01-01

    Quorum sensing (QS) describes the exchange of chemical signals in bacterial populations to adjust the bacterial phenotypes according to the density of bacterial cells. This serves to express phenotypes that are advantageous for the group and ensure bacterial survival. To do so, bacterial cells synthesize autoinducer (AI) molecules, release them to the environment, and take them up. Thereby, the AI concentration reflects the cell density. When the AI concentration exceeds a critical threshold in the cells, the AI may activate the expression of virulence-associated genes or of luminescent proteins. It has been argued that targeting the QS system puts less selective pressure on these pathogens and should avoid the development of resistant bacteria. Therefore, the molecular components of QS systems have been suggested as promising targets for developing new anti-infective compounds. Here, we review the QS systems of selected gram-negative and gram-positive bacteria, namely, Vibrio fischeri, Pseudomonas aeruginosa, and Staphylococcus aureus, and discuss various antivirulence strategies based on blocking different components of the QS machinery. PMID:26819549

  16. Bacterial tactic responses.

    Science.gov (United States)

    Armitage, J P

    1999-01-01

    Many, if not most, bacterial species swim. The synthesis and operation of the flagellum, the most complex organelle of a bacterium, takes a significant percentage of cellular energy, particularly in the nutrient limited environments in which many motile species are found. It is obvious that motility accords cells a survival advantage over non-motile mutants under normal, poorly mixed conditions and is an important determinant in the development of many associations between bacteria and other organisms, whether as pathogens or symbionts and in colonization of niches and the development of biofilms. This survival advantage is the result of sensory control of swimming behaviour. Although too small to sense a gradient along the length of the cell, and unable to swim great distances because of buffetting by Brownian motion and the curvature resulting from a rotating flagellum, bacteria can bias their random swimming direction towards a more favourable environment. The favourable environment will vary from species to species and there is now evidence that in many species this can change depending on the current physiological growth state of the cell. In general, bacteria sense changes in a range of nutrients and toxins, compounds altering electron transport, acceptors or donors into the electron transport chain, pH, temperature and even the magnetic field of the Earth. The sensory signals are balanced, and may be balanced with other sensory pathways such as quorum sensing, to identify the optimum current environment. The central sensory pathway in this process is common to most bacteria and most effectors. The environmental change is sensed by a sensory protein. In most species examined this is a transmembrane protein, sensing the external environment, but there is increasing evidence for additional cytoplasmic receptors in many species. All receptors, whether sensing sugars, amino acids or oxygen, share a cytoplasmic signalling domain that controls the activity of a

  17. Channel-Forming Bacterial Toxins in Biosensing and Macromolecule Delivery

    Directory of Open Access Journals (Sweden)

    Philip A. Gurnev

    2014-08-01

    Full Text Available To intoxicate cells, pore-forming bacterial toxins are evolved to allow for the transmembrane traffic of different substrates, ranging from small inorganic ions to cell-specific polypeptides. Recent developments in single-channel electrical recordings, X-ray crystallography, protein engineering, and computational methods have generated a large body of knowledge about the basic principles of channel-mediated molecular transport. These discoveries provide a robust framework for expansion of the described principles and methods toward use of biological nanopores in the growing field of nanobiotechnology. This article, written for a special volume on “Intracellular Traffic and Transport of Bacterial Protein Toxins”, reviews the current state of applications of pore-forming bacterial toxins in small- and macromolecule-sensing, targeted cancer therapy, and drug delivery. We discuss the electrophysiological studies that explore molecular details of channel-facilitated protein and polymer transport across cellular membranes using both natural and foreign substrates. The review focuses on the structurally and functionally different bacterial toxins: gramicidin A of Bacillus brevis, α-hemolysin of Staphylococcus aureus, and binary toxin of Bacillus anthracis, which have found their “second life” in a variety of developing medical and technological applications.

  18. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten;

    2010-01-01

    Bacteria and Eukarya share essentially the same family of protein-serine/threonine kinases, also known as the Hanks-type kinases. However, when it comes to protein-tyrosine phosphorylation, bacteria seem to have gone their own way. Bacterial protein-tyrosine kinases (BY-kinases) are bacterial...... enzymes that are unique in exploiting the ATP/GTP-binding Walker motif to catalyze phosphorylation of protein tyrosine residues. Characterized for the first time only a decade ago, BY-kinases have now come to the fore. Important regulatory roles have been linked with these enzymes, via their involvement...... in exopolysaccharide production, virulence, DNA metabolism, stress response and other key functions of the bacterial cell. BY-kinases act through autophosphorylation (mainly in exopolysaccharide production) and phosphorylation of other proteins, which have in most cases been shown to be activated by...

  19. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  20. Phylogenetic organization of bacterial activity.

    Science.gov (United States)

    Morrissey, Ember M; Mau, Rebecca L; Schwartz, Egbert; Caporaso, J Gregory; Dijkstra, Paul; van Gestel, Natasja; Koch, Benjamin J; Liu, Cindy M; Hayer, Michaela; McHugh, Theresa A; Marks, Jane C; Price, Lance B; Hungate, Bruce A

    2016-09-01

    Phylogeny is an ecologically meaningful way to classify plants and animals, as closely related taxa frequently have similar ecological characteristics, functional traits and effects on ecosystem processes. For bacteria, however, phylogeny has been argued to be an unreliable indicator of an organism's ecology owing to evolutionary processes more common to microbes such as gene loss and lateral gene transfer, as well as convergent evolution. Here we use advanced stable isotope probing with (13)C and (18)O to show that evolutionary history has ecological significance for in situ bacterial activity. Phylogenetic organization in the activity of bacteria sets the stage for characterizing the functional attributes of bacterial taxonomic groups. Connecting identity with function in this way will allow scientists to begin building a mechanistic understanding of how bacterial community composition regulates critical ecosystem functions. PMID:26943624

  1. Abdominal radiation causes bacterial translocation

    International Nuclear Information System (INIS)

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa

  2. Ion chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Tarter, J.G.

    1987-01-01

    Similar in many ways to other liquid chromatographic techniques, ion chromatography (IC) is an invaluable method that is used all too rarely in chemical analysis. Its application is particularly promising in the analysis of inorganic anions, an area where more information is needed. Ion Chromatogrphy identifies the merits of this technique. Serving as a review and reference for experienced ion chromatographers and as a teaching aid for individuals new to the field, it provides the information necessary for determining the potential usefulness of IC for a given situation. Among the areas treated, this volume focuses on eluant-suppressed IC, especially for anion and cation analysis, single-column IC, plus ancillary techniques and applications, electrochemical, spectroscopic, and other detecting methods, ion chromatography exclusion (ICE), including its limits and applications.

  3. Bacterial contamination of blood components.

    Science.gov (United States)

    Seghatchian, J

    2001-10-01

    Despite considerable advances in the safety of blood components, transfusion associated bacterial infection (TABI) remains an unresolved problem. As yet there are no perfect preventative, screening and/or detection methodologies for eliminating contaminated units. Until a practical, rapid, cost-effective and logistically acceptable test becomes available, we should be satisfied with the choice of various limited solutions that at least partially improve the bacterial safety of blood components. It is also necessary to establish standardised guidelines and agreed upon systematic procedures for the recognition and reporting of the laboratory and clinical evaluation of adverse reactions in recipients of contaminated blood components. PMID:11761277

  4. Molecular Mechanisms Underlying Bacterial Persisters

    DEFF Research Database (Denmark)

    Maisonneuve, Etienne; Gerdes, Kenn

    2014-01-01

    All bacteria form persisters, cells that are multidrug tolerant and therefore able to survive antibiotic treatment. Due to the low frequencies of persisters in growing bacterial cultures and the complex underlying molecular mechanisms, the phenomenon has been challenging to study. However, recent...... technological advances in microfluidics and reporter genes have improved this scenario. Here, we summarize recent progress in the field, revealing the ubiquitous bacterial stress alarmone ppGpp as an emerging central regulator of multidrug tolerance and persistence, both in stochastically and environmentally...

  5. Development of bacterially resistant polyurethane for coating medical devices

    International Nuclear Information System (INIS)

    Polyurethanes have been widely used in medicine for coating and packaging implantable and other medical devices. Polyether-urethanes, in particular, have superior mechanical properties and are biocompatible, but in common with other medical materials they are susceptible to microbial film formation. In this study, polyether-urethane was end-capped with silver lactate and silver sulfadiazine functional groups to produce a bacterially resistant polymer without sacrificing the useful mechanical properties of the polyether-polyurethane. The silver ions were covalently incorporated into the polymer during chain extension of the prepolymer. The functionalized polymers were structurally characterized by light scattering, electron microscopy, NMR, FTIR and Raman spectroscopy. Mechanical properties, hydrophilicity, in vitro stability and antibacterial action of polymers were also investigated. Results indicate that both silver salts were successfully incorporated into the polymer structure without significant effect on mechanical properties, whilst conferring acceptable bacterial resistance.

  6. The assessment of pellicular anion-exchange resins for the determination of anions by ion chromatography

    International Nuclear Information System (INIS)

    Because pellicular anion-exchange resins suitable for the determination, by ion chromatography, of anions with alkaline eluents were unavailable in South Africa at the inception of this work, an attempt was made to prepare such resins. In this study it is shown that the pellicular resins produced are more efficient than the surface-aminated resins used previously. The simultaneous separation and determination of five common anions is demonstrated. The method was applied to the analysis of uranium leach liquors, effluent samples, and a solid sample of ferric oxide (goethite)

  7. Rare earth element fractionation during the precipitation and crystallisation of hydrous ferric oxides from anoxic lake water

    International Nuclear Information System (INIS)

    geochemical conditions comparable to the experimental oxidation time from 3 to 6 weeks are found and hydrous ferric oxides are precipitating. Groundwater passing through the mining dumps can preferentially desorb LREE from the Fe precipitates and display the typical LREE enrichment and carry it to the epilimnion of the acidic pit lakes in Lower Lusatia

  8. Effects of a cocarcinogen, ferric oxide, on the metabolism of benzo[a]pyrene in the isolated perfused lung

    International Nuclear Information System (INIS)

    An isolated perfused New Zealand rabbit lung preparation was used to investigate the effects of a cocarcinogen, ferric oxide (Fe2O3), on the metabolism of benzo[a]pyrene (BaP), a ubiquitous potent carcinogen that has been associated with the increased incidence of human bronchiogenic carcinoma in occupational and urban settings. [14C]-BaP was administered intratracheally to an isolated perfused lung (IPL) preparation with and without Fe2O3 after intraperitoneal pretreatment of the whole animal with BaP or intratracheal pretreatment of the whole animal with Fe2O3 and/or BaP. BaP and its metabolites were isolated from serial blood samples up to 180 min after administration of [14C]BaP to the IPL. BaP and its metabolites were also isolated from lung tissue, washout fluid, macrophage, and trachea bronchi at the end of the perfusion at 180 min. Patterns of BaP metabolites were determined by chromatographic techniques and liquid scintillation counting. Fe2O3 pretreatment to the whole animal or administration of Fe2O3 to the IPL altered BaP metabolism by the perfused lung. Fe2O3 pretreatment to the whole animal resulted in an increase in the total rate of appearance of metabolites of BaP in the blood, while Fe2O3 administration to the IPL resulted in a decrease in the total rate of appearance of BaP metabolites in the blood and inhibited the effect of pretreatment. These data suggest that pulmonary exposure to a known cocarcinogen, Fe2O3, in the presence of BaP results in increased production of dihydrodiols of BaP, which may be further metabolized to the ultimate carcinogenic form(s) of BaP. Therefore, Fe2O3 can enhance the metabolic activation of BaP by the lung, as well as act as a carrier for penetration and retention of BaP in the lung. 49 references, 6 tables

  9. Flexible magnetic membranes based on bacterial cellulose and its evaluation as electromagnetic interference shielding material

    Energy Technology Data Exchange (ETDEWEB)

    Marins, Jéssica A., E-mail: Jessica.amarins@gmail.com [Universidade Federal do Rio de Janeiro/ Instituto de Macromoléculas, Centro de Tecnologia, Rio de Janeiro, RJ (Brazil); Soares, Bluma G., E-mail: bluma@ima.ufrj.br [Universidade Federal do Rio de Janeiro/ Instituto de Macromoléculas, Centro de Tecnologia, Rio de Janeiro, RJ (Brazil); Barud, Hernane S.; Ribeiro, Sidney J.L. [Universidade Estadual Paulista, Instituto de Química, UNESP, Araraquara, SP (Brazil)

    2013-10-15

    Flexible magnetic membranes with high proportion of magnetite were successfully prepared by previous impregnation of the never dried bacterial cellulose pellicles with ferric chloride followed by reduction with sodium bisulfite and alkaline treatment for magnetite precipitation. Membranes were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating magnetometer, field emission scanning electron microscopy (FEG-SEM) and impedance spectroscopy. Microwave properties of these membranes were investigated in the X-band (8.2 to 12.4 GHz). FEG-SEM micrographs show an effective coverage of the BC nanofibers by Fe{sub 3}O{sub 4} nanoparticles. Membranes with up to 75% in weight of particles have been prepared after 60 min of reaction. Magnetite nanoparticles in the form of aggregates well adhered to the BC fibers were observed by SEM. The average crystal sizes of the magnetic particles were in the range of 10 ± 1 to 13 ± 1 nm (estimated by XRD). The magnetic particles in the BC pellicles presented superparamagnetic behavior with a saturation magnetization in the range of 60 emu g{sup −1} and coercive force around 15 Oe. These magnetic pellicles also displayed high electrical permittivity and a potential application as microwave absorber materials. - Highlights: • Bacterial cellulose/magnetite nanocomposites with high incorporation degree of nanoparticles. • Magnetite nanoparticles well adhered to the surface of bacterial cellulose nanofibers. • A saturation magnetization of the nanoparticles in the BC pellicles of about 60 emu g{sup −1}. • Flexible membranes with high super-paramagnetic characteristic.

  10. Mineralogy of Juventae Chasma: Sulfates in the light-toned mounds, mafic minerals in the bedrock, and hydrated silica and hydroxylated ferric sulfate on the plateau

    Science.gov (United States)

    Bishop, Janice L.; Parente, Mario; Weitz, Catherine M.; Noe Dobrea, Eldar Z.; Roach, Leah H.; Murchie, Scott L.; McGuire, Patrick C.; McKeown, Nancy K.; Rossi, Christopher M.; Brown, Adrian J.; Calvin, Wendy M.; Milliken, Ralph; Mustard, John F.

    2009-11-01

    Juventae Chasma contains four light-toned sulfate-bearing mounds (denoted here as A-D from west to east) inside the trough, mafic outcrops at the base of the mounds and in the wall rock, and light-toned layered deposits of opal and ferric sulfates on the plateau. Hyperspectral visible/near-infrared Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectra were used to identify monohydrated and polyhydrated sulfate (PHS) outcrops of layered material on the bright mounds. Most of the monohydrated sulfate signatures closely resemble those of szomolnokite (FeSO4·H2O), characterized by a water band near 2.08 μm, while some areas exhibit spectral features more similar to those of kieserite (MgSO4·H2O), with a band centered closer to 2.13 μm. The largest PHS outcrops occur on the top of mound B, and their spectral features are most consistent with ferricopiapite, melanterite, and starkeyite, but a specific mineral cannot be uniquely identified at this time. Coordinated analyses of CRISM maps, Mars Orbiter Laser Altimeter elevations, and High Resolution Imaging Science Experiment images suggest that mounds A and B may have formed together and then eroded into separate mounds, while mounds C and D likely formed separately. Mafic minerals (low-Ca pyroxene, high-Ca pyroxene, and olivine) are observed in large ˜2-10 km wide outcrops in the wall rock and in smaller outcrops ˜50-500 m across at the floor of the canyon. Most of the wall rock is covered by at least a thin layer of dust and does not exhibit strong features characteristic of these minerals. The plateau region northwest of Juventae Chasma is characterized by an abundance of light-toned layered deposits. One region contains two spectrally unique phases exhibiting a highly stratified, terraced pattern. CRISM spectra of one unit eroded into swirling patterns with arc-like ridges exhibit a narrow 2.23-μm band assigned to hydroxylated ferric sulfate. A thin layer of a fractured material bearing an

  11. Oxidation of sulphide minerals-VI Ferrous and ferric iron in the water-soluble oxidation products of iron sulphide minerals.

    Science.gov (United States)

    Steger, H F

    1979-06-01

    A pseudo-kinetic method has been developed for determining the ferrous and ferric iron in the water-soluble oxidation products of pyrrhotite, pyrite and chalcopyrite, and ores and concentrates containing them. Two determinations are required for each material. In one, the total iron is determined with 1,10-phenanthroline after reduction to Fe(II). In the other, the reduction of Fe(III) is retarded by complexation with fluoride. The difference in the amount of ferrous phenanthranoline complex produced in these two determinations is a function of the original FE(III) concentration and of time. PMID:18962467

  12. Investigation of ozone and coagulant material’s (aluminum sulfate, ferric chloride, poly aluminum chloride and lime efficiency in “Kerman Kork” industry wastewater treatment

    Directory of Open Access Journals (Sweden)

    Amir Hussein Javid

    2015-01-01

    Full Text Available Background: Entry of untreated wastewater of wool scouring factories has been associated with many environmental hazards because of high rate of pollution. Presently effective treatment methods and reducing the costs of operation and maintenance from treatment units have always been under the attention of this industry owners. The aim of this survey is to present a suitable method for the treatment of wool scouring. Methods: In this study, chemical coagulant is used for wastewater treatment (aluminum sulfate, ferric chloride, poly aluminum chloride and lime. And then these materials with “ozone” as a strong oxidative in reduction of the amount of Chemical Oxygen Demand (COD in wastewater effluent has been surveyed. Results: The results of this work showed that only ferric chloride and aluminum sulfate among the above chemical coagulant had a high efficiency in the turbidity removal. Productivity of turbidity removal using ferric chloride with the pH of 4 to 5 was 99%, and turbidity was reduced from 166 Nephelometric Turbidity Units (NTU to 1.5 NTU, and productivity of turbidity removal using aluminum sulfate within the pH 4.5 to 5 was 99.33% that reduced turbidity from 166 to 1.1 NTU. Results of ozonation with 5 g/hour and the oxygen flow of 2.5 litter per min with the pH assess of 15, 30, 45, 60, 90, 120, and 150 min to wastewater from chemical treatment with ferric chloride showed that the rate of COD was reduced from 24700 mg/L to 2940 mg/L. In ozonation to wastewater of chemical treatment with aluminum sulfate within the above rang of time, the rate of COD was reduced from 22500 mg/l to 4800 mg/l. Conclusion: We can be hopeful that in near future, getting the cheap technology of ozone production in industrial scale, one can use this technology for the propose of removal of pollutants having removal preferable by help of advanced treatment approaches.

  13. Ferric hydrogen sulfate supported on silica-coated nickel ferrite nanoparticles as new and green magnetically separable catalyst for 1,8-dioxodecahydroacridine synthesis

    Institute of Scientific and Technical Information of China (English)

    Amir Khojastehnezhad; Mohammad Rahimizadeh; Hossein Eshghi; Farid Moeinpour; Mehdi Bakavoli

    2014-01-01

    A new magnetically separable catalyst consisting of ferric hydrogen sulfate supported on sili-ca-coated nickel ferrite nanoparticles was prepared. The synthesized catalyst was characterized using vibrating sample magnetometry, X-ray diffraction, transmission electron microscopy, scan-ning electron microscopy, and Fourier transform infrared spectroscopy. This new magnetic catalyst was shown to be an efficient heterogeneous catalyst for the synthesis of 1,8- dioxodecahydroacri-dines under solvent-free conditions. The catalyst is readily recovered by simple magnetic decanta-tion and can be recycled several times with no significant loss of catalytic activity.

  14. Catalytic performance and structural characterization of ferric oxide and its composite oxides supported gold catalysts for low-temperature CO oxidation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The preparation and catalytic activity of ferric oxide and its composite oxides supported gold catalysts for Iow-temperature CO oxidation were investigated detailedly, and characterized extensively by XRD, XPS, TPR, EC and XAFS techniques. It was found that containing highly dis persed Au of partially oxidized state, these nano-structured oxides supported Au/Fe2O3 and Au/NiFe2O4 catalysts had higher Iow-temperature activities. The possible catalytic active center is the gold of partially oxidized state (Auζ+).

  15. Disease notes - Bacterial root rot

    Science.gov (United States)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  16. Regulation of Bacterial Peptidoglycan Polymerization.

    Science.gov (United States)

    Arthur, Michel

    2016-07-01

    How bacterial cells control the activity of peptidoglycan polymerases has remained mysterious. Biochemical characterization of derivatives of penicillin-binding protein PBP1b that are functional in the absence of lipoprotein LpoB provides evidence for allosteric control of PBP1b glycosyltransferase activity via binding of LpoB to the PBP1b UBH1 domain. PMID:27236859

  17. How carotenoids protect bacterial photosynthesis.

    OpenAIRE

    Cogdell, R J; Howard, T. D.; Bittl, R.; Schlodder, E; Geisenheimer, I; Lubitz, W.

    2000-01-01

    The essential function of carotenoids in photosynthesis is to act as photoprotective agents, preventing chlorophylls and bacteriochlorophylls from sensitizing harmful photodestructive reactions in the presence of oxygen. Based upon recent structural studies on reaction centres and antenna complexes from purple photosynthetic bacteria, the detailed organization of the carotenoids is described. Then with specific reference to bacterial antenna complexes the details of the photoprotective role, ...

  18. Food irradiation and bacterial toxins

    International Nuclear Information System (INIS)

    The authors' findings indicate that irradiation confers no advantage over heat processing in respect of bacterial toxins (clostridium botulinum, neurotoxin A and staphylococcal enterotoxin A). It follows that irradiation at doses less than the ACINF recommended upper limit of 10 kGy could not be used to improve the ambient temperature shelf life on non-acid foods. (author)

  19. Biotechnological applications of bacterial cellulases

    Directory of Open Access Journals (Sweden)

    Esther Menendez

    2015-08-01

    Full Text Available Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, meanwhile exoglucanases cleave the remaining oligosaccharide chains, originating cellobiose, which is hydrolyzed by ß-glucanases. Bacterial cellulases (EC 3.2.1.4 are comprised in fourteen Glycosil Hydrolase families. Several advantages, such as higher growth rates and genetic versatility, emphasize the suitability and advantages of bacterial cellulases over other sources for this group of enzymes. This review summarizes the main known cellulolytic bacteria and the best strategies to optimize their cellulase production, focusing on endoglucanases, as well as it reviews the main biotechnological applications of bacterial cellulases in several industries, medicine and agriculture.

  20. BACTERIAL INHIBITORS IN LAKE WATER

    Science.gov (United States)

    The populations of six bacterial genera fell rapidly after their addition to sterile lake water but not after their addition to buffer. The decline in numbers of two species that were studied further, Klebsiella pneumoniae and Micrococcus flavus, occurred even when the buffer was...

  1. Bacterial kidney disease (Renibacterium salmoninarum)

    Science.gov (United States)

    Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a prevalent disease of salmonid fish that impacts sustainable production for consumption and species conservation efforts. The disease is chronic in nature and mortality most often occurs in juvenile salmonids and prespawning a...

  2. Relation of bacterial settlement patterns to anodic activity on stainless steel weldments

    Energy Technology Data Exchange (ETDEWEB)

    Eashwar, M.; Dexter, S.C. [Univ. of Delaware, Lewes, DE (United States). Coll. of Marine Studies

    1999-11-01

    Bacterial settlement on welded stainless steel samples exposed to seawater occurred more rapidly in the heat-affected zone (HAZ) and the root of the weld as compared to the parent metal. Preferential attachment of bacteria to a network of surface cracks was an occasional feature, which became more conspicuous during mild anodic polarization of the samples. In a less corrosive fresh water system, bacterial settlement was more random, until application of anodic polarization which triggered bacterial settlement patterns analogous to the sea water system. Supplementary experiments on bacterial response to pre-initiated corrosion sites in the form of pits and scratches reinforced the idea that bacteria preferentially colonize areas of anodic electrochemical activity and/or metal ion release.

  3. Newer systems for bacterial resistances to toxic heavy metals.

    OpenAIRE

    Silver, S; Ji, G.

    1994-01-01

    Bacterial plasmids contain specific genes for resistances to toxic heavy metal ions including Ag+, AsO2-, AsO4(3-), Cd2+, Co2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, Sb3+, and Zn2+. Recent progress with plasmid copper-resistance systems in Escherichia coli and Pseudomonas syringae show a system of four gene products, an inner membrane protein (PcoD), an outer membrane protein (PcoB), and two periplasmic Cu(2+)-binding proteins (PcoA and PcoC). Synthesis of this system is governed by two regulator...

  4. Cognitive outcome in adults after bacterial meningitis.

    NARCIS (Netherlands)

    Hoogman, M.; Beek, D. van de; Weisfelt, M.; Gans, J. de; Schmand, B.

    2007-01-01

    OBJECTIVE: To evaluate cognitive outcome in adult survivors of bacterial meningitis. METHODS: Data from three prospective multicentre studies were pooled and reanalysed, involving 155 adults surviving bacterial meningitis (79 after pneumococcal and 76 after meningococcal meningitis) and 72 healthy c

  5. Electro-active hybrid actuators based on freeze-dried bacterial cellulose and PEDOT:PSS

    International Nuclear Information System (INIS)

    We report a high-performance electro-active hybrid actuator based on freeze-dried bacterial cellulose and conducting polymer electrodes. The freeze-dried bacterial cellulose, which has a sponge form, can absorb a much greater amount of ionic liquid, which is a prerequisite for dry-type and high-performance electro-active polymers. In addition, the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) conducting layers are deposited on the top and bottom surfaces of the freeze-dried bacterial cellulose using a simple dipping and drying method. The results show that the freeze-dried bacterial cellulose actuator with conducting polymer electrodes has a much larger tip displacement under electrical stimuli than pure bacterial cellulose actuators with metallic electrodes. The large bending displacement of the freeze-dried bacterial cellulose actuator under low input voltage is due to the synergistic effects of the ion migration of the dissociated ionic liquids inside the bacterial cellulose and the electrochemical doping processes of the PEDOT:PSS electrode layers. (paper)

  6. Electro-active hybrid actuators based on freeze-dried bacterial cellulose and PEDOT:PSS

    Science.gov (United States)

    Kim, Si-Seup; Jeon, Jin-Han; Kee, Chang-Doo; Oh, Il-Kwon

    2013-08-01

    We report a high-performance electro-active hybrid actuator based on freeze-dried bacterial cellulose and conducting polymer electrodes. The freeze-dried bacterial cellulose, which has a sponge form, can absorb a much greater amount of ionic liquid, which is a prerequisite for dry-type and high-performance electro-active polymers. In addition, the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) conducting layers are deposited on the top and bottom surfaces of the freeze-dried bacterial cellulose using a simple dipping and drying method. The results show that the freeze-dried bacterial cellulose actuator with conducting polymer electrodes has a much larger tip displacement under electrical stimuli than pure bacterial cellulose actuators with metallic electrodes. The large bending displacement of the freeze-dried bacterial cellulose actuator under low input voltage is due to the synergistic effects of the ion migration of the dissociated ionic liquids inside the bacterial cellulose and the electrochemical doping processes of the PEDOT:PSS electrode layers.

  7. Spatial distribution of marine airborne bacterial communities

    OpenAIRE

    Seifried, Jasmin S; Wichels, Antje; Gerdts, Gunnar

    2015-01-01

    The spatial distribution of bacterial populations in marine bioaerosol samples was investigated during a cruise from the North Sea to the Baltic Sea via Skagerrak and Kattegat. The analysis of the sampled bacterial communities with a pyrosequencing approach revealed that the most abundant phyla were represented by the Proteobacteria (49.3%), Bacteroidetes (22.9%), Actinobacteria (16.3%), and Firmicutes (8.3%). Cyanobacteria were assigned to 1.5% of all bacterial reads. A core of 37 bacterial ...

  8. Bacterial population genetics, evolution and epidemiology.

    OpenAIRE

    Spratt, B. G.; Maiden, M C

    1999-01-01

    Asexual bacterial populations inevitably consist of an assemblage of distinct clonal lineages. However, bacterial populations are not entirely asexual since recombinational exchanges occur, mobilizing small genome segments among lineages and species. The relative contribution of recombination, as opposed to de novo mutation, in the generation of new bacterial genotypes varies among bacterial populations and, as this contribution increases, the clonality of a given population decreases. In con...

  9. Population Genomics and the Bacterial Species Concept

    OpenAIRE

    Riley, Margaret A.; Lizotte-Waniewski, Michelle

    2009-01-01

    In recent years, the importance of horizontal gene transfer (HGT) in bacterial evolution has been elevated to such a degree that many bacteriologists now question the very existence of bacterial species. If gene transfer is as rampant as comparative genomic studies have suggested, how could bacterial species survive such genomic fluidity? And yet, most bacteriologists recognize, and name, as species, clusters of bacterial isolates that share complex phenotypic properties. The Core Genome Hypo...

  10. Filtration properties of bacterial cellulose membranes

    OpenAIRE

    Lehtonen, Janika

    2015-01-01

    Bacterial cellulose has the same molecular formula as cellulose from plant origin, but it is characterized by several unique properties including high purity, crystallinity and mechanical strength. These properties are dependent on parameters such as the bacterial strain used, the cultivation conditions and post-growth processing. The possibility to achieve bacterial cellulose membranes with different properties by varying these parameters could make bacterial cellulose an interesting materi...

  11. Bacterial leaching of Pb -metallurgical wastes

    OpenAIRE

    Fečko, Peter; Janáková, Iva; Pertile, Eva; Kulová, Eliška

    2011-01-01

    The aim of this paper is verification of application of bacterial leaching and calcination to recover heavy metals from metallurgical wastes - matte from metallurgical plant Kovohute Pribram. For bacterial leaching a pure bacterial culture of Acidithiobacillus ferrooxidans was used. For a verification test an original sample of matte and matte from 2004 year were used. This paper further shows changes in the samples after bacterial leaching and after calcination. The paper results...

  12. Bacterial oesophagitis in an immunocompromised patient.

    OpenAIRE

    Radhi, J M; Schweiger, F

    1994-01-01

    Bacterial oesophagitis is an uncommon and poorly described entity affecting particularly the immunosuppressed patient. The diagnosis rests on the demonstration of bacterial invasion of the oesophageal wall in the absence of other pathological processes. The causative organisms usually are Gram-positive cocci and there may be associated bacteraemia. The case report describes a leukaemic patient with bacteraemic bacterial oesophagitis.

  13. Tobacco use increases susceptibility to bacterial infection

    OpenAIRE

    Demuth Donald R; Bagaitkar Juhi; Scott David A

    2008-01-01

    Abstract Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacteri...

  14. Isolation and identification of ferric reducing bacteria and evaluation of their roles in iron availability in two calcareous soils

    Science.gov (United States)

    Ghorbanzadeh, N.; Lakzian, A.; Haghnia, G. H.; Karimi, A. R.

    2014-12-01

    Iron is an essential element for all organisms which plays a crucial role in important biochemical processes such as respiration and photosynthesis. Iron deficiency seems to be an important problem in many calcareous soils. Biological dissimilatory Fe(III) reduction increases iron availability through reduction of Fe(III) to Fe(II). The aim of this study was to isolate, identify and evaluate some bacterial isolates for their abilities to reduce Fe(III) in two calcareous soils. Three bacterial isolates were selected and identified from paddy soils by using 16S rRNA amplification and then inoculated to sterilized and non-sterilized calcareous soils in the presence and absence of glucose. The results showed that all isolates belonged to Bacillus genus and were capable of reducing Fe(III) to Fe(II) in vitro condition. The amount of Fe(III) reduction in sterilized calcareous soils was significantly higher when inoculated with PS23 isolate and Shewanella putrefaciens ( S. putrefaciens) (as positive control) compared to PS16 and PS11 isolates. No significant difference was observed between PS11 and PS16 isolates in the presence of indigenous microbial community. The results also revealed that glucose had a significant effect on Fe(III) reduction in the examined calcareous soil samples. The amount of Fe(III) reduction increased two-fold when soil samples were treated with glucose and inoculated by S. putrefaciens and PS23 in non-sterilized soils.

  15. Standard test methods for pitting and crevice corrosion resistance of stainless steels and related alloys by use of ferric Chloride solution

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 These test methods cover procedures for the determination of the resistance of stainless steels and related alloys to pitting and crevice corrosion (see Terminology G 15) when exposed to oxidizing chloride environments. Six procedures are described and identified as Methods A, B, C, D, E, and F. 1.1.1 Method A—Ferric chloride pitting test. 1.1.2 Method B—Ferric chloride crevice test. 1.1.3 Method C—Critical pitting temperature test for nickel-base and chromium-bearing alloys. 1.1.4 Method D—Critical crevice temperature test for nickel-base and chromium-bearing alloys. 1.1.5 Method E—Critical pitting temperature test for stainless steels. 1.1.6 Method F—Critical crevice temperature test for stainless steels. 1.2 Method A is designed to determine the relative pitting resistance of stainless steels and nickel-base, chromium-bearing alloys, whereas Method B can be used for determining both the pitting and crevice corrosion resistance of these alloys. Methods C, D, E and F allow for a rankin...

  16. Novel mechanisms power bacterial gliding motility.

    Science.gov (United States)

    Nan, Beiyan; Zusman, David R

    2016-07-01

    For many bacteria, motility is essential for survival, growth, virulence, biofilm formation and intra/interspecies interactions. Since natural environments differ, bacteria have evolved remarkable motility systems to adapt, including swimming in aqueous media, and swarming, twitching and gliding on solid and semi-solid surfaces. Although tremendous advances have been achieved in understanding swimming and swarming motilities powered by flagella, and twitching motility powered by Type IV pili, little is known about gliding motility. Bacterial gliders are a heterogeneous group containing diverse bacteria that utilize surface motilities that do not depend on traditional flagella or pili, but are powered by mechanisms that are less well understood. Recently, advances in our understanding of the molecular machineries for several gliding bacteria revealed the roles of modified ion channels, secretion systems and unique machinery for surface movements. These novel mechanisms provide rich source materials for studying the function and evolution of complex microbial nanomachines. In this review, we summarize recent findings made on the gliding mechanisms of the myxobacteria, flavobacteria and mycoplasmas. PMID:27028358

  17. Polyethylenimine coated bacterial cellulose nanofiber membrane and application as adsorbent and catalyst.

    Science.gov (United States)

    Wang, Jianqiang; Lu, Xinkun; Ng, Pui Fai; Lee, Ka I; Fei, Bin; Xin, John H; Wu, Jian-yong

    2015-02-15

    Bacterial cellulose (BC) nanofiber membranes were simply aminalized by a flush-coating and post-crosslinking method. Firstly, wet BC membranes were flushed through by an aqueous solution of polyethylenimine (PEI) and glycerol diglycidyl ether (GDE) under vacuum suction, then further heated up to 70 °C to crosslink the resultant coating on the surface of the nanofibers. The PEI coated bacterial cellulose (BC@PEI) nanofiber membrane presented excellent adsorption performance for Cu(2+) and Pb(2+) ions from aqueous solutions. Desorption of these ions was achieved using ethylene diamine tetraacetic acid treatment. This cycle of adsorption and desorption was repeated for several times with good remain adsorption performance (over 90%). Furthermore, the adsorbed Cu(2+) ions can be reduced to copper nanoparticles, and showed excellent catalytic performance for methylene blue reduction in aqueous solution. The catalytic performance can remained after several times of usage. PMID:25460686

  18. Direct observation of the low-spin Fe(III)-NO(radical) intermediate state during rebinding of NO to photodeligated ferric cytochrome c.

    Science.gov (United States)

    Park, Jaeheung; Lee, Taegon; Lim, Manho

    2013-10-10

    Nitrosylated ferric heme is autoreduced readily to the more stable Fe(II)-NO adduct, but it is stabilized in NO-carrier heme proteins where maintaining the Fe(III) oxidation state is crucial for efficient NO delivery. Density functional theory calculations by Lehnert and co-workers have shown that a NO-bound ferric model heme has a low-spin (LS) Fe(III)-NO(radical) state that might be critical for efficient NO transport by NO-carrier heme proteins. Recently, the elusive LS Fe(III)-NO(radical) state was observed as an electronic intermediate state during geminate rebinding (GR) of NO to ferric myoglobin (Mb(III)). Cytochrome c (Cytc), a ubiquitous heme protein, is useful for generalizing the presence of the LS Fe(III)-NO(radical) state. Photoexcitation dynamics of NO-bound ferric Cytc (Cytc(III)NO) was probed after excitation of Cytc(III)NO in D2O solution at 294 K with a 575 nm pulse using femtosecond vibrational spectroscopy. The time-resolved spectra displayed several weak absorption bands in the 1900-1800 cm(-1) range and a dominant bleach at 1917 cm(-1), the position of the absorption at equilibrium. Two absorptions, with 37 cm(-1) isotope shift of (15)NO, shifted toward higher energy and narrowed with an average time constant of 8 ps, indicating that they arose from thermally and/or vibrationally excited NO in the ground electronic state of Cytc(III)NO. Three absorption bands, showing 33 cm(-1) isotope shift of (15)NO and peaked at 1865, 1836, and 1807 cm(-1), were assigned to the deligated NO residing in the interior of the protein, to the rebound Cytc(III)NO in the LS Fe(III)-NO(radical) state, and to the vibrationally excited NO of Cytc(III)NO in the LS Fe(III)-NO(radical) state, respectively. The quantum yield for NO deligation of Cytc(III)NO by a 575 nm photon was 0.8 ± 0.1. Most of the deligated NO showed non-exponential GR, and the GR kinetics was described by exp(-(t/7 ps)(0.7)). Every rebound Cytc(III)NO formed the LS Fe(III)-NO(radical) state that

  19. Ferric iron remediation and stabilisation (firs) - developing a new robust electrokinetic remediation technique for heavy metal and radionuclide contaminated sites

    Energy Technology Data Exchange (ETDEWEB)

    Faulkner, D.; Hopkinson, L. [Brighton Univ, Div. of Civil Engineering and Geology (United Kingdom); Cundy, A. [Sussex Univ., Centre for Environmental Research, Brighton (United Kingdom)

    2005-07-01

    Electrokinetic remediation is an emerging technology that has generated considerable interest as a technique for the in-situ remediation of contaminated clay-rich soils and sediments. Despite promising experimental results, however, at present there is no standardised universal electrokinetic soil/sediment remediation approach. Many of the current technologies are technically complex and energy intensive, and geared towards the removal of 90% or more of specific contaminants, under very specific field or laboratory-based conditions. However, in the real environment a low-tech, low-energy contaminant reduction / containment technique may be more appropriate and realistic. Such a technique, FIRS (Ferric Iron Remediation and Stabilisation), is discussed here. The FIRS technique involves the application of a low magnitude (typically less than 0.2 V/cm) direct electric potential between two or more sacrificial, iron-rich, electrodes emplaced either side of a contaminated soil or sediment. The electric potential is used to generate a strong pH (and Eh) gradient within the soil column (pH 2 - 13), which acts to re-mobilize contaminants in the treated soil, and force the precipitation of an impermeable, sorptive iron-rich barrier or 'pan' in the soil between the electrodes. Geochemical data from bench-scale treatment cells indicate that the FIRS technique can significantly reduce the concentration of a range of heavy metals and radionuclides in contaminated soils, by remobilization of contaminants followed by precipitation on, or around, the iron-rich barrier generated by the technique. In addition, arsenic seems highly amenable to the FIRS treatment, due to its solubility under the high pH conditions generated near to the cathode, and its marked geochemical affinity with the freshly precipitated iron oxides and oxy-hydroxides in the iron barrier. Geotechnical tests indicate that the iron barrier produced by the technique is practically impervious (permeability

  20. Bacterial chromosome organization and segregation.

    Science.gov (United States)

    Badrinarayanan, Anjana; Le, Tung B K; Laub, Michael T

    2015-01-01

    If fully stretched out, a typical bacterial chromosome would be nearly 1 mm long, approximately 1,000 times the length of a cell. Not only must cells massively compact their genetic material, but they must also organize their DNA in a manner that is compatible with a range of cellular processes, including DNA replication, DNA repair, homologous recombination, and horizontal gene transfer. Recent work, driven in part by technological advances, has begun to reveal the general principles of chromosome organization in bacteria. Here, drawing on studies of many different organisms, we review the emerging picture of how bacterial chromosomes are structured at multiple length scales, highlighting the functions of various DNA-binding proteins and the impact of physical forces. Additionally, we discuss the spatial dynamics of chromosomes, particularly during their segregation to daughter cells. Although there has been tremendous progress, we also highlight gaps that remain in understanding chromosome organization and segregation. PMID:26566111

  1. Dynamics of bacterial gene regulation

    Science.gov (United States)

    Narang, Atul

    2009-03-01

    The phenomenon of diauxic growth is a classical problem of bacterial gene regulation. The most well studied example of this phenomenon is the glucose-lactose diauxie, which occurs because the expression of the lac operon is strongly repressed in the presence of glucose. This repression is often explained by appealing to molecular mechanisms such as cAMP activation and inducer exclusion. I will begin by analyzing data showing that these molecular mechanisms cannot explain the strong lac repression because they exert a relatively weak effect. I will then present a minimal model accounting only for enzyme induction and dilution, which yields strong repression despite the absence of catabolite repression and inducer exclusion. The model also explains the growth patterns observed in batch and continuous cultures of various bacterial strains and substrate mixtures. The talk will conclude with a discussion of the experimental evidence regarding positive feedback, the key component of the minimal model.

  2. Collective Functionality through Bacterial Individuality

    Science.gov (United States)

    Ackermann, Martin

    According to the conventional view, the properties of an organism are a product of nature and nurture - of its genes and the environment it lives in. Recent experiments with unicellular organisms have challenged this view: several molecular mechanisms generate phenotypic variation independently of environmental signals, leading to variation in clonal groups. My presentation will focus on the causes and consequences of this microbial individuality. Using examples from bacterial genetic model systems, I will first discuss different molecular and cellular mechanisms that give rise to bacterial individuality. Then, I will discuss the consequences of individuality, and focus on how phenotypic variation in clonal populations of bacteria can promote interactions between individuals, lead to the division of labor, and allow clonal groups of bacteria to cope with environmental uncertainty. Variation between individuals thus provides clonal groups with collective functionality.

  3. Bacterial survival in Martian conditions

    CERN Document Server

    D'Alessandro, Giuseppe Galletta; Giulio Bertoloni; Maurizio

    2010-01-01

    We shortly discuss the observable consequences of the two hypotheses about the origin of life on Earth and Mars: the Lithopanspermia (Mars to Earth or viceversa) and the origin from a unique progenitor, that for Earth is called LUCA (the LUCA hypothesis). To test the possibility that some lifeforms similar to the terrestrial ones may survive on Mars, we designed and built two simulators of Martian environments where to perform experiments with different bacterial strains: LISA and mini-LISA. Our LISA environmental chambers can reproduce the conditions of many Martian locations near the surface trough changes of temperature, pressure, UV fluence and atmospheric composition. Both simulators are open to collaboration with other laboratories interested in performing experiments on many kind of samples (biological, minerals, electronic) in situations similar to that of the red planet. Inside LISA we have studied the survival of several bacterial strains and endospores. We verified that the UV light is the major re...

  4. Bacterial streamers in curved microchannels

    Science.gov (United States)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  5. Immunization by a bacterial aerosol

    OpenAIRE

    Garcia-Contreras, Lucila; Wong, Yun-Ling; Muttil, Pavan; Padilla, Danielle; Sadoff, Jerry; DeRousse, Jessica; Germishuizen, Willem Andreas; Goonesekera, Sunali; Elbert, Katharina; Bloom, Barry R.; Miller, Rich; Fourie, P. Bernard; Hickey, Anthony; Edwards, David

    2008-01-01

    By manufacturing a single-particle system in two particulate forms (i.e., micrometer size and nanometer size), we have designed a bacterial vaccine form that exhibits improved efficacy of immunization. Microstructural properties are adapted to alter dispersive and aerosol properties independently. Dried “nanomicroparticle” vaccines possess two axes of nanoscale dimensions and a third axis of micrometer dimension; the last one permits effective micrometer-like physical dispersion, and the form...

  6. Small intestinal bacterial overgrowth syndrome

    OpenAIRE

    Jan Bures, Jiri Cyrany, Darina Kohoutova, Miroslav Förstl, Stanislav Rejchrt, Jaroslav Kvetina, Viktor Vorisek, Marcela Kopacova

    2010-01-01

    Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestina...

  7. Small intestinal bacterial overgrowth syndrome.

    OpenAIRE

    Bures, J.; Cyrany, J.; Kohoutova, D.; Förstl, M.; Rejchrt, S.; Kvetina, J.; Vorisek, V.; Kopacova, M.

    2010-01-01

    Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestina...

  8. Bacterial degradation of bile salts

    OpenAIRE

    Philipp, Bodo

    2011-01-01

    Bile salts are surface-active steroid compounds. Their main physiological function is aiding the digestion of lipophilic nutrients in intestinal tracts of vertebrates. Many bacteria are capable of transforming and degrading bile salts in the digestive tract and in the environment. Bacterial bile salt transformation and degradation is of high ecological relevance and also essential for the biotechnological production of steroid drugs. While biotechnological aspects have been reviewed many time...

  9. Bacterial communication and group behavior

    OpenAIRE

    Greenberg, E. Peter

    2003-01-01

    The existence of species-specific and interspecies bacterial cell-cell communication and group organization was only recently accepted. Researchers are now realizing that the ability of these microbial teams to communicate and form structures, known as biofilms, at key times during the establishment of infection significantly increases their ability to evade both host defenses and antibiotics. This Perspective series discusses the known signaling mechanisms, the roles they play in both chroni...

  10. Bacterial survival in Martian conditions

    OpenAIRE

    Galletta, Giuseppe; Bertoloni, Giulio; D'Alessandro, Maurizio

    2010-01-01

    We shortly discuss the observable consequences of the two hypotheses about the origin of life on Earth and Mars: the Lithopanspermia (Mars to Earth or viceversa) and the origin from a unique progenitor, that for Earth is called LUCA (the LUCA hypothesis). To test the possibility that some lifeforms similar to the terrestrial ones may survive on Mars, we designed and built two simulators of Martian environments where to perform experiments with different bacterial strains: LISA and mini-LISA. ...

  11. Rheumatoid arthritis and bacterial infections

    OpenAIRE

    N L Prokopjeva; N N Vesikova; I M Marusenko; V A Ryabkov

    2008-01-01

    To study features of bacterial infections course in pts with rheumatoid arthritis (RA) and changes of laboratory measures after focus of infection sanation. Material and methods. 46 pts with definite rheumatoid arthritis were examined at the time of comorbid infection (Cl) detection and after infection focus sanation. Bacteriological test with evaluation of flora sensitivity to antibiotics by disco-diffusion method was performed at baseline and after the course of antibacterial therapy to ass...

  12. Molecular approaches for bacterial azoreductases

    OpenAIRE

    Montira Leelakriangsak

    2013-01-01

    Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N-) in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study...

  13. Biotechnological applications of bacterial cellulases

    OpenAIRE

    Esther Menendez; Paula Garcia-Fraile; Raul Rivas

    2015-01-01

    Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, mean...

  14. Population dynamics of bacterial persistence

    OpenAIRE

    Patra, Pintu

    2014-01-01

    The life of microorganisms is characterized by two main tasks, rapid growth under conditions permitting growth and survival under stressful conditions. The environments, in which microorganisms dwell, vary in space and time. The microorganisms innovate diverse strategies to readily adapt to the regularly fluctuating environments. Phenotypic heterogeneity is one such strategy, where an isogenic population splits into subpopulations that respond differently under identical environments. Bacteri...

  15. Bacterial infections: antibiotics and decontamination.

    Science.gov (United States)

    Gould, Dinah

    Infectious disease is caused by bacteria, viruses, fungi, protozoa and micro-organisms including the mycoplasmas, rickettsiae and chlamydiae. Most of the infections commonly encountered in the UK are caused either by bacteria or viruses. This article describes bacterial structure and function to explain how antibiotics work and the processes of decontamination such as cleaning, disinfection and sterilisation, which are important in infection control. PMID:15224613

  16. Small intestinal bacterial overgrowth syndrome

    Institute of Scientific and Technical Information of China (English)

    Jan; Bures; Jiri; Cyrany; Darina; Kohoutova; Miroslav; Frstl; Stanislav; Rejchrt; Jaroslav; Kvetina; Viktor; Vorisek; Marcela; Kopacova

    2010-01-01

    Human intestinal microbiota create a complex polymi-crobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO).SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastro-intestinal tract. There...

  17. Bacterial meningitis by streptococcus agalactiae

    OpenAIRE

    Villarreal-Velásquez Tatiana Paola; Cortés-Daza César Camilo

    2012-01-01

    Introduction: bacterial meningitis is an infectious disease considered a medicalemergency. The timely management has an important impact on the evolution of thedisease. Streptococcus agalactiae, a major causative agent of severe infections innewborns can colonize different tissues, including the central nervous system.Case report: Male patient 47 years old from rural areas, with work activity as amilker of cattle, referred to tertiary care, with disorientation, neck stiffness, and grandmal se...

  18. Organization of the bacterial chromosome.

    OpenAIRE

    Krawiec, S.; Riley, M

    1990-01-01

    Recent progress in studies on the bacterial chromosome is summarized. Although the greatest amount of information comes from studies on Escherichia coli, reports on studies of many other bacteria are also included. A compilation of the sizes of chromosomal DNAs as determined by pulsed-field electrophoresis is given, as well as a discussion of factors that affect gene dosage, including redundancy of chromosomes on the one hand and inactivation of chromosomes on the other hand. The distinction ...

  19. Bacterial sex in dental plaque

    Directory of Open Access Journals (Sweden)

    Ingar Olsen

    2013-06-01

    Full Text Available Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it affects a number of the major genera present. It has been estimated that new sequences in genomes established through horizontal gene transfer can constitute up to 30% of bacterial genomes. Gene transfer can be both inter- and intrageneric, and it can also affect transient organisms. The transferred DNA can be integrated or recombined in the recipient's chromosome or remain as an extrachromosomal inheritable element. This can make dental plaque a reservoir for antimicrobial resistance genes. The ability to transfer DNA is important for bacteria, making them better adapted to the harsh environment of the human mouth, and promoting their survival, virulence, and pathogenicity.

  20. Bacterial strategies for chemotaxis response.

    Science.gov (United States)

    Celani, Antonio; Vergassola, Massimo

    2010-01-26

    Regular environmental conditions allow for the evolution of specifically adapted responses, whereas complex environments usually lead to conflicting requirements upon the organism's response. A relevant instance of these issues is bacterial chemotaxis, where the evolutionary and functional reasons for the experimentally observed response to chemoattractants remain a riddle. Sensing and motility requirements are in fact optimized by different responses, which strongly depend on the chemoattractant environmental profiles. It is not clear then how those conflicting requirements quantitatively combine and compromise in shaping the chemotaxis response. Here we show that the experimental bacterial response corresponds to the maximin strategy that ensures the highest minimum uptake of chemoattractants for any profile of concentration. We show that the maximin response is the unique one that always outcompetes motile but nonchemotactic bacteria. The maximin strategy is adapted to the variable environments experienced by bacteria, and we explicitly show its emergence in simulations of bacterial populations in a chemostat. Finally, we recast the contrast of evolution in regular vs. complex environments in terms of minimax vs. maximin game-theoretical strategies. Our results are generally relevant to biological optimization principles and provide a systematic possibility to get around the need to know precisely the statistics of environmental fluctuations. PMID:20080704