WorldWideScience

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. 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...

  3. Mechanism of influence of ferric ion on electrogenerative leaching of sulfide minerals with FeCl3

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-fen; FANG Zheng

    2006-01-01

    A dual cell system was used to study the influence of ferric ion on the electrogenerative leaching of sulfide minerals.Reaction mechanisms for the ferric chloride electrogenerative leaching of a series of sulfide minerals were proposed based on the data collected from the dual cell experiments. The influences of ferric ion on the electrogenerative leaching of sulfide minerals are similar. Ferric ion plays an important role on limiting the electrogenerative leaching rate at a relatively low concentration of FeCl3(about less than 0.15 mol/L). The mathematical models based on the Butler-Volmer relation were delineated, and kinetic equations with respect to ferric ions for each sulfide mineral were obtained. The kinetic equations show that when the concentration of ferric ion is relatively low, the electrogenerative leaching rates are predicted to be proportional to 6/7, 4/5, 2/3 and 2/3 order of ferric ion for nickel concentrate, chalcopyrite concentrate, sphalerite and galena respectively. As the concentration of ferric ion increase, the correlative dependence between electrogenerative leaching rate and concentration of ferric ion becomes weak. The above conclusions are in agreement with the experimental results.

  4. A novel mode of ferric ion coordination by the periplasmic ferric ion-binding subunit FbpA of an ABC-type iron transporter from Thermus thermophilus HB8.

    Science.gov (United States)

    Wang, Shipeng; Ogata, Misaki; Horita, Shoichiro; Ohtsuka, Jun; Nagata, Koji; Tanokura, Masaru

    2014-01-01

    Crystal structures of FbpA, the periplasmic ferric ion-binding protein of an iron-uptake ABC transporter, from Thermus thermophilus HB8 (TtFbpA) have been solved in apo and ferric ion-bound forms at 1.8 and 1.7 Å resolution, respectively. The latter crystal structure shows that the bound ferric ion forms a novel six-coordinated complex with three tyrosine side chains, two bicarbonates and a water molecule in the metal-binding site. The results of gel-filtration chromatography and dynamic light scattering show that TtFbpA exists as a monomer in solution regardless of ferric ion binding and that TtFbpA adopts a more compact conformation in the ferric ion-bound state than in the apo state in solution.

  5. 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%.

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

    Science.gov (United States)

    Liu, Shaogang; Zhu, Zhiliang; Qiu, Yanling; Zhao, Jianfu

    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.

  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. Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jie; Ju, Yuyun; Liu, Juanjuan; Zhang, Huige [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xingguo, E-mail: chenxg@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

    2015-01-07

    Highlights: • A new method for synthesis of the BPEI-CuNCs is established. • A facile approach for Fe{sup 3+} ion sensing by fluorescence quenching is developed. • The method for Fe{sup 3+} sensing has high sensitivity and excellent selectivity. - Abstract: In this report we reported a facile one-pot method for synthesis of water-soluble and stable fluorescent CuNCs at room temperature, in which branched polyethyleneimine (BPEI) served as capping scaffold and ascorbic acid as reducing agent. The prepared BPEI-CuNCs exhibited excellent properties such as good water-solubility, photostability and high stability toward high ionic strength. Based on the electron transfer induced fluorescence quenching mechanism, this fluorescence probe was used for the sensitive and selective determination of ferric ions (Fe{sup 3+}) in aqueous solution. The limit of detection was 340 nM in the linear range of 0.5–1000 μM, which was lower than the maximum level of Fe{sup 3+} permitted in drinking water by the U.S. Environmental Protection Agency. The method was successfully applied to the detection of Fe{sup 3+} in tap water, Yellow River water and human urine samples with the quantitative spike recoveries ranging from 95.3% to 112.0%.

  14. 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

  15. 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%.

  16. [Effects of bromide and ferric ions on formation of tri-halomethanes during disinfection of drinking water by chlorine].

    Science.gov (United States)

    Zhu, Zhi-Liang; Wang, Jing; Ge, Yuan-Xin; Ma, Hong-Mei; Zhao, Jian-Fu

    2007-06-01

    Effects of bromide and ferric ions on the formation and distribution of tri-halomethanes (THMs) have been investigated. As disinfection by-product (DBP) model precursors of natural water, humic acid solutions were used and a series of experiments were conducted. The results showed that bromide in this reaction system not only contributed to the increase of brominated species, but also the total tri-halomethanes. When the concentration of Br(-) was 1.0 mg/L, the total amount of produced THMs reached to 270% of that without bromide ions. In the presence of bromide, ferric ions decreased the production of THMs at pH 6, but increased the production of THMs at pH 8, especially for the amount of tri-bromomethanes. When the concentration of Fe3+ was 5 mg/L, the amount of produced tri-bromomethanes had an increment of 54% (from 51.7 microg/L to 79.4 microg/L), and the total amount of THMs increased from 113.49 microg/L to 162.09 microg/L. Bromide ions had a significant effect on carcinogenicity risk in disinfection of drinking water by chlorine, and the co-existence of ferric ion and bromide in alkalescent environment can result in the biggest challenge on carcinogenicity risk. Under the condition of 0.2 mg/L Br(-), 5 mg/L Fe3+ and pH 6, the carcinogenicity risk increased 2.5 times than that without Br(-) and Fe3+, and much higher increment of 5.1 times appeared when pH was 8.

  17. 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.

  18. [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.

  19. 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.

  20. 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...

  1. Performance evaluation of ALCAN-AASF50-ferric coated activated alumina and granular ferric hydroxide (GFH) for arsenic removal in the presence of competitive ions in an active well :Kirtland field trial - initial studies.

    Energy Technology Data Exchange (ETDEWEB)

    Neidel, Linnah L.; Krumhansl, James Lee; Siegel, Malcolm Dean; Khandaker, Nadim Reza

    2006-01-01

    This report documents a field trial program carried out at Well No.15 located at Kirtland Air Force Base, Albuquerque, New Mexico, to evaluate the performance of two relatively new arsenic removal media, ALCAN-AASF50 (ferric coated activated alumina) and granular ferric hydroxide (US Filter-GFH). The field trial program showed that both media were able to remove arsenate and meet the new total arsenic maximum contaminant level (MCL) in drinking water of 10 {micro}g/L. The arsenate removal capacity was defined at a breakthrough effluent concentration of 5 {micro}g/L arsenic (50% of the arsenic MCL of 10 {micro}g/L). At an influent pH of 8.1 {+-} 0.4, the arsenate removal capacity of AASF50 was 33.5 mg As(V)/L of dry media (29.9 {micro}g As(V)/g of media on a dry basis). At an influent pH of 7.2 {+-} 0.3, the arsenate removal capacity of GFH was 155 mg As(V)/L of wet media (286 {micro}g As(V)/g of media on a dry basis). Silicate, fluoride, and bicarbonate ions are removed by ALCAN AASF50. Chloride, nitrate, and sulfate ions were not removed by AASF50. The GFH media also removed silicate and bicarbonate ions; however, it did not remove fluoride, chloride, nitrate, and sulfate ions. Differences in the media performance partly reflect the variations in the feed-water pH between the 2 tests. Both the exhausted AASF50 and GFH media passed the Toxicity Characteristic Leaching Procedure (TCLP) test with respect to arsenic and therefore could be disposed as nonhazardous waste.

  2. 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

  3. Reducing dissolution of MnO2 nanofibers by doping with ferric ion

    Directory of Open Access Journals (Sweden)

    Huimin Chen et al

    2007-01-01

    Full Text Available MnO2 nanofiber was found to possess high adsorption capacities for heavy metal ions such as, arsenic and lead, in water due to its high specific surface area (SSA and high surface activity. However, a significant amount of manganese was found to leach from MnO2 nanofibers. Reducing MnO2 dissolution is very important for improving its applications in drinking water treatment. In this study, MnO2 nanofiber was doped with Fe3+ to reduce its dissolution in water. Dissolution tests were conducted on un-doped and Fe-doped MnO2 nanofibers. The results revealed that doping with Fe3+ significantly reduced MnO2 dissolution. SSA and defects of MnO2 materials were analyzed by BET and XRD methods. The effects of Fe3+ on MnO2 dissolution were discussed and the optimal dopant amount was identified.

  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. Impact of the Ferric Ion and Ferrous Ion Changes on Industrial Boilers Acid Pickling%铁离子、亚铁离子变化对工业锅炉酸洗的影响

    Institute of Scientific and Technical Information of China (English)

    谢桂杰

    2015-01-01

    This paper introduces the source of ferric ion in industrial boiler acid pickling, and proposes to strengthen the chemical monitoring of ferric ion and ferrous ion(Fe3+、Fe2+)by examples, to ensure the safety of acid pickling of boiler and the judgment of end.%介绍工业锅炉酸洗中铁离子的来源,并以实例说明酸洗中应强化对铁离子、亚铁离子(Fe3+、Fe2+)的化学监测,使锅炉酸洗安全进行,及终点的判断。

  6. 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%.

  7. 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

  8. 饱和非饱和分层土壤中铁离子运移试验%Experimental study on migration of ferric ion in saturated-unsaturated layered soils

    Institute of Scientific and Technical Information of China (English)

    詹美礼; 林凤标; 罗玉龙; 盛金昌

    2011-01-01

    This essay is inclined to present the findings of our experimental study on the migration of iron remnants in the saturated-unsat-urated layered soils. Our study is different from the existing researches about the migration processes of ferric ion in groundwater in that the already existing studies mainly focus on the ferric ion concentration mechanisms, ferric ion distribution in groundwater, ferric ion migration processes in saturated soil iron, etc. Few of them are devoted to the study of the migration process of ferric ion in saturated-unsatu-rated horizontal layered soils. We have developed a saturated-unsatu-rated horizontal layered soil box experimental model, which is made up of clay, sandy loam and fine send, with our aim focused on the migration process of ferric ion in saturated-unsaturated layered soils. The experimental results of our study show that: the migration process of ferric ion is closely related to the layered order of different soils; at the same time, the farther it is from pollution sources, the lower the concentration will be for the points on the same horizontal plane; and for the point on the vertical plane, the concentration becomes higher and higher from top to bottom. Therefore, the migration capability of ferric ion in the fine sand, sandy loam and clay tends to decrease gradually, and the migration velocities of ferric ion are respectively 1/1 224 m/h, 1/2 200 m/h and 1/3 605 m/h in fine sand, sandy soil and clay under the condition of hydraulic gradient 2.5% . And, therefore, it can be made sure that the experimental results presented in this paper will bring about imputes to improve our understanding of the migration processes of ferric ion in saturated and unsaturated layered soils, and also helps to lay a theoretic basis for better treatment of ferric ion pollution in the future.%建立了由黏土、砂壤土、细砂组成的饱和非饱和分层大型土槽试验模型,以研究铁离子在饱和非饱和分层土壤中的

  9. 麦汁中铁离子的去除及酒体稳定性的研究%Removing Ferric Ion from Wort and Study on Beer Stability

    Institute of Scientific and Technical Information of China (English)

    郑翔鹏; 王国川; 林海峰

    2012-01-01

    本文主要研究啤酒的原辅料、酿造水以及糖化各工序中铁离子的分布情况,重点试验分析使用单宁作为铁离子络合剂的可行性。试验结果显示,使用单宁后,麦汁中铁离子的含量明显降低,可达0.15mg/L以下,酒体抗氧化特性提高10%-15%。研究最终提出了啤酒生产过程中的铁离子关键控制点及要求。%The distribution of ferric ion during glycation of beer production was studied, and so were the content of ferric ion of raw materials, eorn stareh and mash water. Complexant was used to remove the ferrie ion from the wort, and tannin could really work effectively. When tannin was applied, the ferric ion in wort was less than 0.15mg/L, and the anti-oxidization ability of the beer was increased by 10%-15%. Control points for ferric ion during the beer production were also identified in the study.

  10. Bacterial adhesion on ion-implanted stainless steel surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Q. [Department of Mechanical Engineering, University of Dundee, Dundee DD1 4HN (United Kingdom)]. E-mail: q.zhao@dundee.ac.uk; Liu, Y. [Department of Mechanical Engineering, University of Dundee, Dundee DD1 4HN (United Kingdom); Wang, C. [Department of Mechanical Engineering, University of Dundee, Dundee DD1 4HN (United Kingdom); Wang, S. [Department of Mechanical Engineering, University of Dundee, Dundee DD1 4HN (United Kingdom); Peng, N. [Surrey Ion Beam Centre, University of Surrey, Surrey GU2 7XH (United Kingdom); Jeynes, C. [Surrey Ion Beam Centre, University of Surrey, Surrey GU2 7XH (United Kingdom)

    2007-08-31

    Stainless steel disks were implanted with N{sup +}, O{sup +} and SiF{sub 3} {sup +}, 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{sub 3} {sup +}-implanted stainless steel performed much better than N{sup +}-implanted steel, O{sup +}-implanted steel and untreated stainless steel control on reducing bacterial attachment under identical experimental conditions.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. Simulation of ferric ions transfer in dosemeter Fricke-Xylenol-Gel in means no homogeneous; Simulacao da difusao de ions ferricos em dosimetros Fricke-Xilenol-Gel em meios nao homogeneos

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Caio J.; Bevilacqua, Joyce da Silva, E-mail: caio.milani@usp.br, E-mail: joyce@ime.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Matematica e Estatistica. Departamento de Matematica Aplicada; Cavinato, Christianne C.; Rodrigues Junior, Orlando; Campos, Leticia L., E-mail: rodrijr@ipen.br, E-mail: Icrodri@ipen.br, E-mail: ccavinato@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (lPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes

    2013-11-01

    Dosimetry in three dimensions using Fricke-Xilenol-Gel dosimeters (FXG) allows the confirmation and a better understanding of a treatment by Radiotherapy. The technique involves the assessment of the irradiated volumes by magnetic resonance imaging (MRI) or optical-CT. On both cases, the time elapsed between the irradiation and the measurement is an important factor in the quality of results. The quality of the images can be compromised by the mobility of the ferric ions (Fe{sup 3+}), formed during the the interaction of the radiation with the matter, increasing the uncertainty in the determination of the isodoses in the volume. In this work, the phenomenon of the diffusion of the ferric ions formed by an irradiated region is simulated in a bidimensional domain. The dynamic of the Fe{sup 3+} in Fricke-Gel is modeled by a parabolic partial differential equation and solved by the ADI-Peaceman-Rachford algorithm. Stability and consistency of the method guarantee the convergence of the numerical solution for a pre-defined error magnitude, based on choices for the discretization values of time and space. Homogeneous and non-homogeneous cases are presented considering an irradiated region and a physical barrier that prevents the movement of the ions, on the non-homogeneous case. Graphical visualizations of the phenomenon are presented for better understanding of the process. (author)

  16. Diffusion simulation of ferric ions in dosemeter Fricke-gel with variable diffusion coefficient; Simulacao da difusao de ions ferricos em dosimetros Fricke-gel com coeficiente de difusao variavel

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Caio Jacob; Bevilacqua, Joyce da Silva, E-mail: caio.milani@usp.br, E-mail: joyce@ime.usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Matematica e Estatistica. Dept. de Matematica Aplicada; Rodrigues Junior, Orlando, E-mail: rodrijr@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes

    2014-07-01

    Dosimetry using dosimeters Fricke-xylenol-Gel (FXG) allows confirmation and better understanding of radiotherapy treatments. The technique involves the evaluation of volumes irradiated by magnetic resonance imaging (MRI) or CT-optical. In both cases, the time spent between the irradiation and measurement is an important factor that directly influences the results. The quality of the images can be compromised by the mobility of ferric ions (Fe 3+), formed during the interaction of radiation with matter, increasing the uncertainty in determining the isodose. In this work, we simulated the dynamic involving ferric ions formed in one irradiated region irradiated in a two-dimensional domain with a variable diffusion coefficient. This phenomenon is modeled by a differential equation and solved numerically by an efficient algorithm that generalizes the Crank-Nicolson method. The stability and consistency of the method guarantee the convergence of the numerical solution for a predefined tolerance based in the choice of discretization steps of time and space. Different continuous functions were chosen to represent the diffusion coefficient and graphical views of the phenomenon are presented for a better understanding of the process.

  17. 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.

  18. A Soret marker band for four-coordinate ferric heme proteins from absorption spectra of isolated Fe(III)-Heme+ and Fe(III)-Heme+(His) ions in vacuo.

    Science.gov (United States)

    Lykkegaard, Morten Køcks; Ehlerding, Anneli; Hvelplund, Preben; Kadhane, Umesh; Kirketerp, Maj-Britt Suhr; Nielsen, Steen Brøndsted; Panja, Subhasis; Wyer, Jean Ann; Zettergren, Henning

    2008-09-10

    In this work, we report the absorption spectra in the Soret band region of isolated Fe(III)-heme+ and Fe(III)-heme+(His) ions in vacuo from action spectroscopy. Fe(III)-heme+ refers to iron(III) coordinated by the dianion of protoporphyrin IX. We find that the absorption of the five-coordinate complex is similar to that of pentacoordinate metmyoglobin variants with hydrophobic binding pockets except for an overall blueshift of about 16 nm. In the case of four-coordinate iron(III), the Soret band is similar to that of five-coordinate iron(III) but much narrower. These spectra serve as a benchmark for theoretical modeling and also serve to identify the coordination state of ferric heme proteins. To our knowledge this is the first unequivocal spectroscopic characterization of isolated 4c ferric heme in the gas phase. PMID:18700762

  19. 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...

  20. Mechanisms of ion-bombardment-induced DNA transfer into bacterial E. coli cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, L.D., E-mail: yuld@thep-center.org [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sangwijit, K. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Phanchaisri, B. [Institute of Science and Technology Research, Chiang Mai University, Chiang Mai 50200 (Thailand); Thongkumkoon, P. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Singkarat, S. [Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Anuntalabhochai, S. [Molecular Biology Laboratory, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2014-05-01

    Highlights: • Ion bombardment could induce DNA transfer into E. coli cells. • The DNA transfer induction depended on ion energy and fluence. • The mechanism was associated with the bacterial cell envelope structure. • A mechanism phase diagram was proposed to summarize the mechanism. - Abstract: As a useful ion beam biotechnology, ion-bombardment-induced DNA transfer into bacterial Escherichia coli (E. coli) cells has been successfully operated using argon ions. In the process ion bombardment of the bacterial cells modifies the cell envelope materials to favor the exogenous DNA molecules to pass through the envelope to enter the cell. The occurrence of the DNA transfer induction was found ion energy and fluence dependent in a complex manner. At ion energy of a few keV and a few tens of keV to moderate fluences the DNA transfer could be induced by ion bombardment of the bacterial cells, while at the same ion energy but to high fluences DNA transfer could not be induced. On the other hand, when the ion energy was medium, about 10–20 keV, the DNA transfer could not be induced by ion bombardment of the cells. The complexity of the experimental results indicated a complex mechanism which should be related to the complex structure of the bacterial E. coli cell envelope. A phase diagram was proposed to interpret different mechanisms involved as functions of the ion energy and fluence.

  1. Determination of ferric ions content of citric acid based on improved tiron spectrophotometry%基于改进钛铁分光光度法测定柠檬酸液中的三价铁

    Institute of Scientific and Technical Information of China (English)

    樊丽丽; 张军伟; 彭奇均

    2012-01-01

    基于改进钛铁分光光度法,通过pH理论计算确定缓冲溶液配比,建立了高浓度柠檬酸液中三价铁离子的测定方法.研究表明,柠檬酸浓度与所对应的缓冲溶液配比呈二次曲线关系,相关系数达到1;测定高浓度柠檬酸液中三价铁的较佳波长为480 nm,三价铁在1~10mg/L呈良好的线性关系(r=0.9996),加标回收率为95.5%~100.5%,重现性好.%The method of ferric ions content in high concentration citric acid based on the improved tiron spectrophotometry was established. And the buffer solution ration was determinated by theoretical calculation of pH. Results indicated that the relation between ratio of buffer solution and the concentration of citric acid was quadratic function,the correlation coefficient was 1. The optimal absorption wavelength of ferric ion in higher concentration of citric acid based on the improved tiron spectrophotometry was 480 run. There was a good linear relationship between absoibance and content of ferric ion in range of 1 ~ 10 mg/L, and the correlation coefficient was 0. 999 6. The recovery of standard addition was 95. 5% - 100. 5% , good reproducibiliry.

  2. Bacterial metabarcoding by 16S rRNA gene ion torrent amplicon sequencing.

    Science.gov (United States)

    Fantini, Elio; Gianese, Giulio; Giuliano, Giovanni; Fiore, Alessia

    2015-01-01

    Ion Torrent is a next generation sequencing technology based on the detection of hydrogen ions produced during DNA chain elongation; this technology allows analyzing and characterizing genomes, genes, and species. Here, we describe an Ion Torrent procedure applied to the metagenomic analysis of 16S rRNA gene amplicons to study the bacterial diversity in food and environmental samples. PMID:25343859

  3. Bacterial metabarcoding by 16S rRNA gene ion torrent amplicon sequencing.

    Science.gov (United States)

    Fantini, Elio; Gianese, Giulio; Giuliano, Giovanni; Fiore, Alessia

    2015-01-01

    Ion Torrent is a next generation sequencing technology based on the detection of hydrogen ions produced during DNA chain elongation; this technology allows analyzing and characterizing genomes, genes, and species. Here, we describe an Ion Torrent procedure applied to the metagenomic analysis of 16S rRNA gene amplicons to study the bacterial diversity in food and environmental samples.

  4. 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 % .

  5. Effect of ferric ions in AISI 316L stainless steel pickling using an environmentally-friendly H{sub 2}SO{sub 4}-HF-H{sub 2}O{sub 2} mixture

    Energy Technology Data Exchange (ETDEWEB)

    Narvaez, L. [Metallurgical Institute, UASLP Avda. Sierra Leona 550, 78210 San Luis Potosi (Mexico); Cano, E.; Bastidas, J.M. [CENIM-National Centre for Metallurgical Research (CSIC) Avda. Gregorio del Amo 8, 28040 Madrid (Spain)

    2003-02-01

    A mixture of hydrogen peroxide, sulphuric and hydrofluoric acids has been used as pickling solution at pH 2.0 for AISI 316L austenitic stainless steel (SS). The stability of the H{sub 2}SO{sub 4}-HF-H{sub 2}O{sub 2} mixture is assessed varying the ferric ions content from 0 to 40 g/L, the temperature from 25 to 60 C, and with and without stirring of the pickling solution. The AISI 316L SS pickling rate at 50 C was 2.6 and 0.2 mg/dm{sup 2} day (mdd) in the absence and presence of 40 g/L ferric ions, respectively. p-toluene sulphonic acid (PTSA) has been used as stabiliser of hydrogen peroxide. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [German] Es ist ein Gemisch mit einem pH-Wert von 2.0 aus Wasserstoffperoxid, Schwefelsaeure und Fluorwasserstoffsaeure als Beizloesung fuer nichtrostenden Stahl AISI 316L angewandt worden. Die Stabilitaet des Gemisches H{sub 2}SO{sub 4}-HF-H{sub 2}O{sub 2} haengt vom Gehalt der dreiwertigen Eisenionen, zwischen 0 und 40 g/L, von der Temperatur, zwischen 25 und 60 C, und von der Ruehrintensitaet der Beizloesung ab. Die Beizgeschwindigkeit des nichtrostenden Stahls AISI 316L bei 50 C lag bei 2.6 bzw. 0.2 mg/dm{sup 2} taeglich (mdd), je nachdem, ob 40 g/L dreiwertige Eisenionen enthalten waren oder nicht. Als Stabilisator des Wasserstoffperoxids ist para-Toluensulfonsaeure (PTSA) eingesetzt worden. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  6. 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

  7. 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

  8. 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.

  9. Application of air ions for bacterial de-colonization in air filters contaminated by aerosolized bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yang Seon, E-mail: rup2r@yonsei.ac.kr [School of Mechanical Engineering, Yonsei University, 262 Seongsanno, Seodaemun-Gu, Seoul, 120-749 (Korea, Republic of); Yoon, Ki Young, E-mail: yky810921@yonsei.ac.kr [Exhaust Emission Engineering Team, Hyundai Motor Company, Hwaseong 445-706, Republic of Korea (Korea, Republic of); Park, Jae Hong, E-mail: cheap@yonsei.ac.kr [School of Mechanical Engineering, Yonsei University, 262 Seongsanno, Seodaemun-Gu, Seoul, 120-749 (Korea, Republic of); Hwang, Jungho, E-mail: hwangjh@yonsei.ac.kr [School of Mechanical Engineering, Yonsei University, 262 Seongsanno, Seodaemun-Gu, Seoul, 120-749 (Korea, Republic of)

    2011-01-15

    We aerosolized the Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis) bacteria and collected them on membrane filters. Then we generated air ions by applying a high voltage to a carbon fiber tip and applied them to the contaminated filters. The antibacterial efficiency was not significantly affected by the bacteria being Gram-positive or Gram-negative, however, negative ions showed a lower antibacterial efficiency than positive ions to both E. coli and S. epidermidis, even though the concentration of negative air ions was much higher than that of positive air ions. With a field emission scanning electron microscope (FE-SEM) images and fluorescence microscopy images using a LIVE/DEAD BacLight Bacterial Viability Kit, electrostatic disruption of the bacteria was found to be the dominant antibacterial effect. - Research Highlights: {yields}This study examined the effects of air ions generated by a carbon fiber ionizer on the inactivation of bioaerosols. {yields}When the ion exposure time and the ion generation concentration were increased, the antibacterial efficiency increased. {yields}The bioaerosols carried a significant number of negative electrical charges. {yields}Negative ions showed lower antibacterial efficiency than positive ions to both E. coli and S. epidermidis, even though the concentration of negative air ions was much higher than that of positive air ions.

  10. 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

    2016-07-01

    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.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. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02638a

  11. 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

  12. 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

  13. 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

  14. 21 CFR 184.1307 - Ferric sulfate.

    Science.gov (United States)

    2010-04-01

    ... Substances Affirmed as GRAS § 184.1307 Ferric sulfate. (a) Ferric sulfate (iron (III) sulfate, Fe2(SO4)3 CAS Reg. No. 10028-22-5) is a yellow substance that may be prepared by oxidizing iron (II) sulfate or by treating ferric oxide or ferric hydroxide with sulfuric acid. (b) The ingredient must be of a...

  15. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Fritsch, Sebastian M [ORNL; Ivanov, Ivaylo N [ORNL; Wang, Hailong [Mayo Clinic College of Medicine; Cheng, Xiaolin [ORNL

    2011-01-01

    The proton-gated ion channel from Gloeobacter violaceus (GLIC) is a prokaryotic homolog of the eukaryotic nicotinic acetylcholine receptor (nAChR) 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 (PMF) 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 ~10 kcal/mol free energy barrier for a chloride ion, which arises primarily from the unfavorable interactions with a ring of negatively charged glutamate residues (E-2 ) at the intracellular end and a ring of hydrophobic residues (I9 ) in the middle of the transmembrane domain. Our collective findings further suggest that the charge selection mechanism can, to a large extent, be attributed to the narrow intracellular end and a ring of glutamate residues in this position their strong negative electrostatics and ability to bind cations. By contrast, E19 at the extracellular entrance only plays a minor role in ion selectivity of GLIC. In addition to electrostatics, both ion hydration and protein dynamics are found to be crucial for ion conduction as well, which explains why a chloride ion experiences a much greater barrier than a sodium ion in the hydrophobic region of the pore.

  17. 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.

  18. 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...

  19. 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

  20. Pyrolyzed bacterial cellulose: a versatile support for lithium ion battery anode materials.

    Science.gov (United States)

    Wang, Bin; Li, Xianglong; Luo, Bin; Yang, Jingxuan; Wang, Xiangjun; Song, Qi; Chen, Shiyan; Zhi, Linjie

    2013-07-22

    A scalable, low-cost and environmentally benign strategy is developed for the facile construction of a unique kind of three-dimensional porous electrode architecture for high-performance lithium ion batteries. The methodology is based on the employment of pyrolyzed bacterial cellulose as a new three-dimensional porous scaffold to support various nanostructured active electrode materials, such as SnO2 and Ge.

  1. 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 ...

  2. Research of Dislodgment of Ferric Ion Using Modified Rice Husk%改性米糠去除铁离子的研究

    Institute of Scientific and Technical Information of China (English)

    杨惟喜

    2012-01-01

    Using Rice bran as a raw material, after 30rain treatment of a 5% potassium hydroxide solution to boil soak, it becomes a pH≤3.3, the surface area 13m2 / g, the macropore volume of 35.5 ml / g silica precipitation adsorbent i.e. modified rice bran. This paper studied the best condition of using this modified rice bran to remove iron ion in the recovered phosphoric acid solution. Experiment result showed that at room temperature, 3g of the modified rice bran contacted with the iron ions in the phosphoric liquid 24h, filtered, then the purpose of the removal of iron is achieved, the efficiency of this method is up to 90%.This method is a worthy application technology.%以米糠为原料,用5%氢氧化钾液煮沸浸泡30min处理后,形成pH小于3.3,比表面积13m2/g,大孔体积35.5mL/g二氧化硅沉淀吸附剂即改性米糠。本文研究了利用该改性米糠去除回收磷酸液中铁离子的最佳条件。实验结果表明:在常温下,改性米糠3g与磷酸液中的铁离子接触24h,过滤,即可达到除铁的目的,用此法除铁离子效果可达90%,是一种值得推广的应用技术。

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

    Science.gov (United States)

    Luo, Gang; Angelidaki, Irini

    2014-09-01

    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 composition and bacterial pathogens were also studied. Microbial analysis was made by Ion Torrent sequencing of the PCR amplicons from ethidium monoazide treated samples, and ethidium monoazide was used to cleave DNA from dead cells and exclude it from PCR amplification. Both similarity and taxonomic analysis showed that the bacterial community composition in the influent was changed after anaerobic digestion. Firmicutes were dominant in all the samples, while Proteobacteria decreased in the biogas reactor compared with the influent. Variations of bacterial community composition in the biogas reactor with time were also observed. This could be attributed to varying composition of the influent. Batch experiments showed that the methane recovery from the digested residues (obtained from biogas reactor) was mainly related with post-digestion temperature. However, post-digestion time rather than temperature 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 30 days' 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 increase in relative abundance of bacterial pathogens after post-digestion might reflect regrowth of bacterial pathogens and limit biosolids disposal vectors.

  4. 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...

  5. 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

  6. 21 CFR 184.1298 - Ferric citrate.

    Science.gov (United States)

    2010-04-01

    ... Substances Affirmed as GRAS § 184.1298 Ferric citrate. (a) Ferric citrate (iron (III) citrate, C6H5FeO7, CAS Reg. No. 2338-05-8) is prepared from reaction of citric acid with ferric hydroxide. It is a compound of indefinite ratio of citric acid and iron. (b) The ingredient must be of a purity suitable for...

  7. 21 CFR 184.1301 - Ferric phosphate.

    Science.gov (United States)

    2010-04-01

    ... reaction of sodium phosphate with ferric chloride or ferric citrate. (b) The ingredient meets the... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferric phosphate. 184.1301 Section 184.1301 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  8. 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....

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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

  14. Marine Bacterial and Archaeal Ion-Pumping Rhodopsins: Genetic Diversity, Physiology, and Ecology.

    Science.gov (United States)

    Pinhassi, Jarone; DeLong, Edward F; Béjà, Oded; González, José M; Pedrós-Alió, Carlos

    2016-12-01

    The recognition of a new family of rhodopsins in marine planktonic bacteria, proton-pumping proteorhodopsin, expanded the known phylogenetic range, environmental distribution, and sequence diversity of retinylidene photoproteins. At the time of this discovery, microbial ion-pumping rhodopsins were known solely in haloarchaea inhabiting extreme hypersaline environments. Shortly thereafter, proteorhodopsins and other light-activated energy-generating rhodopsins were recognized to be widespread among marine bacteria. The ubiquity of marine rhodopsin photosystems now challenges prior understanding of the nature and contributions of "heterotrophic" bacteria to biogeochemical carbon cycling and energy fluxes. Subsequent investigations have focused on the biophysics and biochemistry of these novel microbial rhodopsins, their distribution across the tree of life, evolutionary trajectories, and functional expression in nature. Later discoveries included the identification of proteorhodopsin genes in all three domains of life, the spectral tuning of rhodopsin variants to wavelengths prevailing in the sea, variable light-activated ion-pumping specificities among bacterial rhodopsin variants, and the widespread lateral gene transfer of biosynthetic genes for bacterial rhodopsins and their associated photopigments. Heterologous expression experiments with marine rhodopsin genes (and associated retinal chromophore genes) provided early evidence that light energy harvested by rhodopsins could be harnessed to provide biochemical energy. Importantly, some studies with native marine bacteria show that rhodopsin-containing bacteria use light to enhance growth or promote survival during starvation. We infer from the distribution of rhodopsin genes in diverse genomic contexts that different marine bacteria probably use rhodopsins to support light-dependent fitness strategies somewhere between these two extremes.

  15. Marine Bacterial and Archaeal Ion-Pumping Rhodopsins: Genetic Diversity, Physiology, and Ecology.

    Science.gov (United States)

    Pinhassi, Jarone; DeLong, Edward F; Béjà, Oded; González, José M; Pedrós-Alió, Carlos

    2016-12-01

    The recognition of a new family of rhodopsins in marine planktonic bacteria, proton-pumping proteorhodopsin, expanded the known phylogenetic range, environmental distribution, and sequence diversity of retinylidene photoproteins. At the time of this discovery, microbial ion-pumping rhodopsins were known solely in haloarchaea inhabiting extreme hypersaline environments. Shortly thereafter, proteorhodopsins and other light-activated energy-generating rhodopsins were recognized to be widespread among marine bacteria. The ubiquity of marine rhodopsin photosystems now challenges prior understanding of the nature and contributions of "heterotrophic" bacteria to biogeochemical carbon cycling and energy fluxes. Subsequent investigations have focused on the biophysics and biochemistry of these novel microbial rhodopsins, their distribution across the tree of life, evolutionary trajectories, and functional expression in nature. Later discoveries included the identification of proteorhodopsin genes in all three domains of life, the spectral tuning of rhodopsin variants to wavelengths prevailing in the sea, variable light-activated ion-pumping specificities among bacterial rhodopsin variants, and the widespread lateral gene transfer of biosynthetic genes for bacterial rhodopsins and their associated photopigments. Heterologous expression experiments with marine rhodopsin genes (and associated retinal chromophore genes) provided early evidence that light energy harvested by rhodopsins could be harnessed to provide biochemical energy. Importantly, some studies with native marine bacteria show that rhodopsin-containing bacteria use light to enhance growth or promote survival during starvation. We infer from the distribution of rhodopsin genes in diverse genomic contexts that different marine bacteria probably use rhodopsins to support light-dependent fitness strategies somewhere between these two extremes. PMID:27630250

  16. 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.

  17. 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

  18. 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

  19. Reinforced Sisal Fiber with Ferric Nitrate Composites

    Directory of Open Access Journals (Sweden)

    Asif Jehan

    2015-06-01

    Full Text Available Ferric oxide synthesized through annealing route. The present research work deals with ferrite composite prepared using chemical reactions. Ferric nitrates and ammonium chloride doped with sisal fiber has been prepared. The structural behavior of aluminum oxide was studied in XRD, SEM, TEM, FTIR & dielectric measurement. This behavior showed ferrite nature of the sample.

  20. 21 CFR 186.1300 - Ferric oxide.

    Science.gov (United States)

    2010-04-01

    ... iron hydroxide oxide. The product is red-brown to black trigonal crystals. (b) In accordance with § 186... Substances Affirmed as GRAS § 186.1300 Ferric oxide. (a) Ferric oxide (iron (III) oxide, Fe2O3, CAS Reg....

  1. 21 CFR 184.1304 - Ferric pyrophosphate.

    Science.gov (United States)

    2010-04-01

    ... colorless powder. It is prepared by reacting sodium pyrophosphate with ferric citrate. (b) The ingredient... 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)...

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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)

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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.

  14. Bacterial nanometric amorphous Fe-based oxide: a potential lithium-ion battery anode material.

    Science.gov (United States)

    Hashimoto, Hideki; Kobayashi, Genki; Sakuma, Ryo; Fujii, Tatsuo; Hayashi, Naoaki; Suzuki, Tomoko; Kanno, Ryoji; Takano, Mikio; Takada, Jun

    2014-04-23

    Amorphous Fe(3+)-based oxide nanoparticles produced by Leptothrix ochracea, aquatic bacteria living worldwide, show a potential as an Fe(3+)/Fe(0) conversion anode material for lithium-ion batteries. The presence of minor components, Si and P, in the original nanoparticles leads to a specific electrode architecture with Fe-based electrochemical centers embedded in a Si, P-based amorphous matrix.

  15. Nonequivalence of membrane voltage and ion-gradient as driving forces for the bacterial flagellar motor at low load.

    Science.gov (United States)

    Lo, Chien-Jung; Leake, Mark C; Pilizota, Teuta; Berry, Richard M

    2007-07-01

    Many bacterial species swim using flagella. The flagellar motor couples ion flow across the cytoplasmic membrane to rotation. Ion flow is driven by both a membrane potential (V(m)) and a transmembrane concentration gradient. To investigate their relation to bacterial flagellar motor function we developed a fluorescence technique to measure V(m) in single cells, using the dye tetramethyl rhodamine methyl ester. We used a convolution model to determine the relationship between fluorescence intensity in images of cells and intracellular dye concentration, and calculated V(m) using the ratio of intracellular/extracellular dye concentration. We found V(m) = -140 +/- 14 mV in Escherichia coli at external pH 7.0 (pH(ex)), decreasing to -85 +/- 10 mV at pH(ex) 5.0. We also estimated the sodium-motive force (SMF) by combining single-cell measurements of V(m) and intracellular sodium concentration. We were able to vary the SMF between -187 +/- 15 mV and -53 +/- 15 mV by varying pH(ex) in the range 7.0-5.0 and extracellular sodium concentration in the range 1-85 mM. Rotation rates for 0.35-microm- and 1-microm-diameter beads attached to Na(+)-driven chimeric flagellar motors varied linearly with V(m). For the larger beads, the two components of the SMF were equivalent, whereas for smaller beads at a given SMF, the speed increased with sodium gradient and external sodium concentration.

  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. 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.

  18. 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

  19. 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.

  20. 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...... with time were also observed. This could be attributed to varying composition of the influent. Batch experiments showed that the methane recovery from the digested residues (obtained from biogas reactor) was mainly related with post-digestion temperature. However, post-digestion time rather than temperature...

  1. 21 CFR 184.1296 - Ferric ammonium citrate.

    Science.gov (United States)

    2010-04-01

    ... citrate (iron (III) ammonium citrate) is prepared by the reaction of ferric hydroxide with citric acid, followed by treatment with ammonium hydroxide, evaporating, and drying. The resulting product occurs in two forms depending on the stoichiometry of the initial reactants. (1) Ferric ammonium citrate (iron...

  2. 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.

  3. 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.

  4. 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...

  5. The ferric enterobactin transporter Fep is required for persistent Salmonella enterica serovar typhimurium infection.

    Science.gov (United States)

    Nagy, Toni A; Moreland, Sarah M; Andrews-Polymenis, Helene; Detweiler, Corrella S

    2013-11-01

    Most bacterial pathogens require iron to grow and colonize host tissues. The Gram-negative bacterium Salmonella enterica serovar Typhimurium causes a natural systemic infection of mice that models acute and chronic human typhoid fever. S. Typhimurium resides in tissues within cells of the monocyte lineage, which limit pathogen access to iron, a mechanism of nutritional immunity. The primary ferric iron import system encoded by Salmonella is the siderophore ABC transporter FepBDGC. The Fep system has a known role in acute infection, but it is unclear whether ferric iron uptake or the ferric iron binding siderophores enterobactin and salmochelin are required for persistent infection. We defined the role of the Fep iron transporter and siderophores in the replication of Salmonella in macrophages and in mice that develop acute followed by persistent infections. Replication of wild-type and iron transporter mutant Salmonella strains was quantified in cultured macrophages, fecal pellets, and host tissues in mixed- and single-infection experiments. We show that deletion of fepB attenuated Salmonella replication and colonization within macrophages and mice. Additionally, the genes required to produce and transport enterobactin and salmochelin across the outer membrane receptors, fepA and iroN, are needed for colonization of all tissues examined. However, salmochelin appears to be more important than enterobactin in the colonization of the spleen and liver, both sites of dissemination. Thus, the FepBDGC ferric iron transporter and the siderophores enterobactin and salmochelin are required by Salmonella to evade nutritional immunity in macrophages and cause persistent infection in mice.

  6. 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.

  7. 21 CFR 73.1025 - Ferric ammonium citrate.

    Science.gov (United States)

    2010-04-01

    ... ferric hydroxide with citric acid in the presence of ammonia. The complex chelates occur in brown and... named to the extent that such impurities may be avoided by good manufacturing practice: Iron (as...

  8. 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)

  9. 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)

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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...

  15. 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)

  16. 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.

  17. Bacillus cereus iron uptake protein fishes out an unstable ferric citrate trimer

    OpenAIRE

    Fukushima, Tatsuya; Sia, Allyson K.; Allred, Benjamin E.; Nichiporuk, Rita; Zhou, Zhongrui; Andersen, Ulla N.; Raymond, Kenneth N.

    2012-01-01

    Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli ferric citrate outer-membrane transport protein FecA has been characterized; little is known about other ferric citrate-binding proteins. Here we report a unique siderophore-binding protein from the Gram-positive pathogenic bacterium Bacillus cereus that binds multinuclear ferric citrate complexes. We have demonstrated ...

  18. Metal-on-metal bearings in total hip arthroplasties : Influence of cobalt chromium ions on bacterial growth and biofilm formation

    NARCIS (Netherlands)

    Hosman, Anton H.; van der Mei, Henny C.; Bulstra, Sjoerd K.; Busscher, Henk J.; Neut, Danielle

    2009-01-01

    Metal-on-metal (MOM) bearings involving cobalt-chromium (Co-Cr) alloys in total hip arthroplasties are becoming more and more popular due to their low wear. Consequences of corrosion products of Co-Cr alloys are for the most part unclear, and the influence of cobalt and chromium ions on biofilm form

  19. 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

  20. 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.

  1. Bacillus cereus iron uptake protein fishes out an unstable ferric citrate trimer.

    Science.gov (United States)

    Fukushima, Tatsuya; Sia, Allyson K; Allred, Benjamin E; Nichiporuk, Rita; Zhou, Zhongrui; Andersen, Ulla N; Raymond, Kenneth N

    2012-10-16

    Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli ferric citrate outer-membrane transport protein FecA has been characterized; little is known about other ferric citrate-binding proteins. Here we report a unique siderophore-binding protein from the gram-positive pathogenic bacterium Bacillus cereus that binds multinuclear ferric citrate complexes. We have demonstrated that B. cereus ATCC 14579 takes up (55)Fe radiolabeled ferric citrate and that a protein, BC_3466 [renamed FctC (ferric citrate-binding protein C)], binds ferric citrate. The dissociation constant (K(d)) of FctC at pH 7.4 with ferric citrate (molar ratio 1:50) is 2.6 nM. This is the tightest binding observed of any B. cereus siderophore-binding protein. Nano electrospray ionization-mass spectrometry (nano ESI-MS) analysis of FctC and ferric citrate complexes or citrate alone show that FctC binds diferric di-citrate, and triferric tricitrate, but does not bind ferric di-citrate, ferric monocitrate, or citrate alone. Significantly, the protein selectively binds triferric tricitrate even though this species is naturally present at very low equilibrium concentrations.

  2. 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....

  3. 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...

  4. Metal ion effects on hydraulic conductivity of bacterial cellulose-pectin composites used as plant cell wall analogs.

    Science.gov (United States)

    McKenna, Brigid A; Kopittke, Peter M; Wehr, J Bernhard; Blamey, F Pax C; Menzies, Neal W

    2010-02-01

    Low concentrations of some trace metals markedly reduce root elongation rate and cause ruptures to root rhizodermal and outer cortical cells in the elongation zone. The interactions between the trace metals and plant components responsible for these effects are not well understood but may be linked to changes in water uptake, cell turgor and cell wall extensibility. An experiment was conducted to investigate the effects of Al, La, Cu, Gd, Sc and Ru on the saturated hydraulic conductivity of bacterial cellulose (BC)-pectin composites, used as plant cell wall analogs. Hydraulic conductivity was reduced to approximately 30% of the initial flow rate by 39 microM Al and 0.6 microM Cu, approximately 40% by 4.6 microM La, 3 microM Sc and 4.4 microM Ru and approximately 55% by 3.4 microM Gd. Scanning electron microscopy (SEM) revealed changes in the ultrastructure of the composites. The results suggest that trace metal binding decreases the hydraulic conductivity through changes in pectin porosity. The experiment illustrates the importance of metal interactions with pectin, and the implications of such an interaction in plant metal toxicity and in normal cell wall processes. PMID:20053181

  5. Phylogenetic diversity of dissimilatory ferric iron reducers in paddy soil of Hunan, South China

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xin-Jun [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Graduate Univ., Chinese Academy of Sciences, BJ (China); Yang Jing; Chen Xue-Ping; Sun Guo-Xin [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Zhu Yong-Guan [State Key Lab. of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, BJ (China); Key Lab. of Urban Environment and Health, Inst. of Urban Environment, Chinese Academy of Sciences, Xiamen (China)

    2009-12-15

    Purpose: Dissimilatory iron-reducing bacteria have been described by both culture-dependent and -independent methods in various environments, including freshwater, marine sediments, natural wetlands, and contaminated aquifers. However, little is known about iron-reducing microbial communities in paddy soils. The goal of this study was to characterize iron-reducing microbial communities in paddy soil. Moreover, the effect of dissolved and solid-phase iron (III) species on the iron-reducing microbial communities was also investigated by enrichment cultures. Methods: Ferric citrate and ferrihydrite were used respectively to set up enrichment cultures of dissimilatory ironreducing microorganisms using 1% inoculum of soil samples, and the iron reduction was measured. Moreover, bacterial DNA was extracted and 16S rRNA genes were PCR-amplified, and subsequently analyzed by the clone library and terminal restriction fragment length polymorphism (T-RFLP). Results: Phylogenetic analysis of 16S rRNA gene sequences extracted from the enrichment cultures revealed that Bradyrhizobium, Bacteroides, Clostridium and Ralstonia species were the dominant bacteria in the ferric citrate enrichment. However, members of the genera Clostridium, Bacteroides, and Geobacter were the dominant micro-organisms in the ferrihydrite enrichment. Analysis of enrichment cultures by T-RFLP strongly supported the cloning and sequencing results. Conclusions: The present study demonstrated that dissimilatory iron-reducing consortia in As-contaminated paddy soil are phylogenetically diverse. Moreover, iron (III) sources as a key factor have a strong effect on the iron (III)-reducing microbial community structure and relative abundance in the enrichments. In addition, Geobacter species are selectively enriched by ferrihydrite enrichment cultures. (orig.)

  6. Absorption in the Q-band region by isolated ferric heme+ and heme+(histidine) in vacuo.

    Science.gov (United States)

    Wyer, Jean Ann; Brøndsted Nielsen, Steen

    2010-08-28

    Absorption by heme proteins is determined by the heme microenvironment that is often vacuumlike (hydrophobic pocket). Here we provide absorption spectra in the Q-band region of isolated ferric heme(+) and heme(+)(histidine) ions in vacuo to be used as references in protein biospectroscopy. Ions were photoexcited in an electrostatic storage ring and their decay monitored in time. Both ions display a triple band structure with maxima at 500, 518, and 530 nm. Previous attempts to study four-coordinate Fe(III)-heme(+) were hampered by the strong affinity of Fe(3+) for water and anions. Absorption at higher wavelengths is also measured, which is ascribed to charge-transfer transitions from the porphyrin to the iron. Finally, our data serve to benchmark theoretical calculations. PMID:20815568

  7. Pros and cons of ion-torrent next generation sequencing versus terminal restriction fragment length polymorphism T-RFLP for studying the rumen bacterial community.

    Science.gov (United States)

    de la Fuente, Gabriel; Belanche, Alejandro; Girwood, Susan E; Pinloche, Eric; Wilkinson, Toby; Newbold, C Jamie

    2014-01-01

    The development of next generation sequencing has challenged the use of other molecular fingerprinting methods used to study microbial diversity. We analysed the bacterial diversity in the rumen of defaunated sheep following the introduction of different protozoal populations, using both next generation sequencing (NGS: Ion Torrent PGM) and terminal restriction fragment length polymorphism (T-RFLP). Although absolute number differed, there was a high correlation between NGS and T-RFLP in terms of richness and diversity with R values of 0.836 and 0.781 for richness and Shannon-Wiener index, respectively. Dendrograms for both datasets were also highly correlated (Mantel test = 0.742). Eighteen OTUs and ten genera were significantly impacted by the addition of rumen protozoa, with an increase in the relative abundance of Prevotella, Bacteroides and Ruminobacter, related to an increase in free ammonia levels in the rumen. Our findings suggest that classic fingerprinting methods are still valuable tools to study microbial diversity and structure in complex environments but that NGS techniques now provide cost effect alternatives that provide a far greater level of information on the individual members of the microbial population.

  8. Removal of Nitrate in the Aqueous Phase Using Granular Ferric Hydroxide

    Directory of Open Access Journals (Sweden)

    Dehghani

    2015-04-01

    Full Text Available Background In recent years, the nitrate concentration in surface water and especially in groundwater was increased significantly in many parts of Iran. Objectives The main objectives of this study were to evaluate the feasibility of using granular ferric hydroxide (GFH to remove nitrate from aqueous phase as well as to determine the removal efficiency at the optimal condition. Materials and Methods The present study was conducted on a bench scale experiment. The spectrophotometer DR5000 (wavelength 520 nm was used to determine the nitrate concentration. The effect of influencing parameters including pH at 5 levels (3.8 - 7.8, initial nitrate concentration at 4 levels (50 - 150 mg/L the amount of adsorbent dose (0.625, 1.25, 2.5, 3.75 g/50mL, the effects of interfering ions, such as sulfate ions at 4 levels (200 - 800 mg/L and chloride ions at 4 levels (200 - 800 mg/L, and contact time at 3 levels (30 - 90 minutes were studied. Results Based on our data, pH of 4.8, adsorbent dose of 3.75 g and contact time of 90 minutes is optimal for nitrate removal. Furthermore, the nitrate reduction rate was increased rapidly by the addition of the adsorbent and decreased by nitrate addition. The nitrate reduction rate was increased by increasing the contact time. The percent of nitrate reduction was significantly enhanced by decreasing the pH (from 7.8 to 8.4 and then reached a plateau with a relative slow equilibration. Moreover, adsorption efficiency was significantly decreased in the presence of interfering ions, such as sulfate and chloride ions. Conclusions In conclusion, GFH can be used as a reliable and appropriate method with high efficiency for the reduction of nitrate in many polluted water resources.

  9. 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.

  10. 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.

  11. 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.

  12. Treatment of Highly Turbid Water by Polyaluminum Ferric Chloride (PAFCL

    Directory of Open Access Journals (Sweden)

    Fazel Fazel Mohammadi-Moghaddam

    2015-10-01

    Full Text Available Background & Aims of the Study: In some situation like rainfall seasons raw water become very turbid so it affected the water treatment plant processes and quality of produced water. Treatment of very high turbid water has some concerns like precursors for disinfection by-products and very loading rate of particle on filter's media and consequently increases in water consumption for filter backwash. This paper investigates the performance of a composite inorganic polymer of aluminium and ferric salt, Polyaluminium ferric chloride (PAFCl, for the removal of turbidity, color and natural organic matter (NOM from high turbid water. Materials and Methods: Experiments were carried out by Jar test experiment by synthetic water samples with 250 and 500 NTU turbidity that prepared in laboratory. Results: The results of conventional jar test showed that the optimum pH for coagulation of water sample was 7.5 to 8 and optimum dosage of the coagulant was 10 mg/L. Removal efficiency of turbidity, color and UV adsorbent at 254 nm at optimum dose and pH without filtration was 99.92%, 100% and 80.6% respectively for first sample (250 NTU and 99.95%, 99.49% and 84.77 for second sample (500 NTU respectively. Conclusion: It concluded that polyaluminium ferric chloride has a very good efficiency for the removal of turbidity, color and organic matter in high turbid water. Also it can be select as a coagulant for high turbid water and some waste water from water treatment plant like filter backwash water.

  13. Functional characterization of the chloroplast ferric chelate oxidoreductase enzyme.

    Science.gov (United States)

    Solti, Adám; Müller, Brigitta; Czech, Viktória; Sárvári, Éva; Fodor, Ferenc

    2014-05-01

    Iron (Fe) has an essential role in the biosynthesis of chlorophylls and redox cofactors, and thus chloroplast iron uptake is a process of special importance. The chloroplast ferric chelate oxidoreductase (cFRO) has a crucial role in this process but it is poorly characterized. To study the localization and mechanism of action of cFRO, sugar beet (Beta vulgaris cv Orbis) chloroplast envelope fractions were isolated by gradient ultracentrifugation, and their purity was tested by western blotting against different marker proteins. The ferric chelate reductase (FCR) activity of envelope fractions was studied in the presence of NAD(P)H (reductants) and FAD coenzymes. Reduction of Fe(III)-ethylenediaminetetraacetic acid was monitored spectrophotometrically by the Fe(II)-bathophenanthroline disulfonate complex formation. FCR activity, that is production of free Fe(II) for Fe uptake, showed biphasic saturation kinetics, and was clearly associated only to chloroplast inner envelope (cIE) vesicles. The reaction rate was > 2.5 times higher with NADPH than with NADH, which indicates the natural coenzyme preference of cFRO activity and its dependence on photosynthesis. FCR activity of cIE vesicles isolated from Fe-deficient plants also showed clear biphasic kinetics, where the KM of the low affinity component was elevated, and thus this component was down-regulated.

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

    Science.gov (United States)

    Friedrisch, João Ricardo; Cançado, Rodolfo Delfini

    2015-01-01

    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. PMID:26670403

  15. 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.

  16. 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

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

    Science.gov (United States)

    Ge, Qingchun; Fu, Fengjiang; Chung, Tai-Shung

    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 2.0 M produced relatively high water fluxes of 39-48 LMH (L m(-2) hr(-1)) with negligible reverse solute fluxes. A water flux of 17.4 LMH was achieved when model seawater of 3.5 wt.% NaCl replaced DI water as the feed and 2.0 M 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.

  18. KINETICS OF H2S ABSORPTION INTO AQUEOUS FERRIC SOLUTIONS OF EDTA AND HEDTA

    NARCIS (Netherlands)

    WUBS, HJ; BEENACKERS, AACM

    1994-01-01

    Kinetics of the reaction of hydrogen sulfide with ferric chelates of ethylenediaminetetraacetic acid (EDTA) at 22-degrees-C and with ferric chelates of hydroxyethylethylenediaminetriacetic acid (HEDTA) from 21-degrees-C to 60-degrees-C were studied in a stirred cell reactor under industrial conditio

  19. 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 th...

  20. Ferric hydrogensulfate catalyzed aerobic oxidative coupling of 2-naphthols in water or under solvent free conditions

    Institute of Scientific and Technical Information of China (English)

    Hossein Eshghi; Mehdi Bakavoli; Hassanali Moradi

    2009-01-01

    The symmetric oxidative coupling reactions of 2-naphthol derivatives withboth ferric hydrogensulfate in water and silica ferric hydrogensulfate in solvent free conditions were carried out. The advantages of this green procedure are: inexpensive catalyst or co-catalyst, reusability of catalyst, organic solvent-free procedures and simple workup.

  1. 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.

  2. 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

    -scale tube reactor. It is revealed that approximately 40% of the sulfur is released as SO3, the remaining fraction being released as SO2. The proposed decomposition model of ferric sulfate is combined with a detailed gas phase kinetic model of KCl sulfation, and a simplified model of K2SO4 condensation...... harmful K2SO4. In the present study the decomposition of ferric sulfate is studied in a fast-heating rate thermogravimetric analyzer (TGA), and a kinetic model is proposed to describe the decomposition process. The yields of SO2 and SO3 from ferric sulfate decomposition are investigated in a laboratory...... in 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...

  3. 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.

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

    Science.gov (United States)

    Ozturk, Levent; Yazici, Atilla; Eker, Selim; Gokmen, Ozgur; Römheld, Volker; Cakmak, Ismail

    2008-01-01

    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 sunflower (Helianthus annuus) roots grown under Fe deficiency conditions. Application of 1.89 mm glyphosate resulted in almost 50% inhibition of ferric reductase within 6 h and complete inhibition 24 h after the treatment. Even at lower rates of glyphosate (e.g. 0.32 mm and 0.95 mm), ferric reductase was inhibited. Soluble sugar concentration and the NAD(P)H oxidizing capacity of apical roots were not decreased by the glyphosate applications. To our knowledge, this is the first study reporting the effects of glyphosate on ferric reductase activity. The nature of the inhibitory effect of glyphosate on ferric reductase could not be identified. Impaired ferric reductase could be a major reason for the increasingly observed Fe deficiency in cropping systems associated with widespread glyphosate usage.

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Defluoridation from aqueous solutions by granular ferric hydroxide (GFH).

    Science.gov (United States)

    Kumar, Eva; Bhatnagar, Amit; Ji, Minkyu; Jung, Woosik; Lee, Sang-Hun; Kim, Sun-Joon; Lee, Giehyeon; Song, Hocheol; Choi, Jae-Young; Yang, Jung-Seok; Jeon, Byong-Hun

    2009-02-01

    This research was undertaken to evaluate the feasibility of granular ferric hydroxide (GFH) for fluoride removal from aqueous solutions. Batch experiments were performed to study the influence of various experimental parameters such as contact time (1 min-24h), initial fluoride concentration (1-100 mgL(-1)), temperature (10 and 25 degrees C), pH (3-12) and the presence of competing anions on the adsorption of fluoride on GFH. Kinetic data revealed that the uptake rate of fluoride was rapid in the beginning and 95% adsorption was completed within 10 min and equilibrium was achieved within 60 min. The sorption process was well explained with pseudo-first-order and pore diffusion models. The maximum adsorption capacity of GFH for fluoride removal was 7.0 mgg(-1). The adsorption was found to be an endothermic process and data conform to Langmuir model. The optimum fluoride removal was observed between pH ranges of 4-8. The fluoride adsorption was decreased in the presence of phosphate followed by carbonate and sulphate. Results from this study demonstrated potential utility of GFH that could be developed into a viable technology for fluoride removal from drinking water.

  12. Exfoliation of Hexagonal Boron Nitride via Ferric Chloride Intercalation

    Science.gov (United States)

    Hung, Ching-cheh; Hurst, Janet; Santiago, Diana; Rogers, Richard B.

    2014-01-01

    Sodium fluoride (NaF) was used as an activation agent to successfully intercalate ferric chloride (FeCl3) into hexagonal boron nitride (hBN). This reaction caused the hBN mass to increase by approx.100 percent, the lattice parameter c to decrease from 6.6585 to between 6.6565 and 6.6569 ?, the x-ray diffraction (XRD) (002) peak to widen from 0.01deg to 0.05deg of the full width half maximum value, the Fourier transform infrared (FTIR) spectrum's broad band (1277/cm peak) to change shape, and new FTIR bands to emerge at 3700 to 2700 and 1600/cm. This indicates hBN's structural and chemical properties are significantly changed. The intercalated product was hygroscopic and interacted with moisture in the air to cause further structural and chemical changes (from XRD and FTIR). During a 24-h hold at room temperature in air with 100 percent relative humidity, the mass increased another 141 percent. The intercalated product, hydrated or not, can be heated to 750 C in air to cause exfoliation. Exfoliation becomes significant after two intercalation-air heating cycles, when 20-nm nanosheets are commonly found. Structural and chemical changes indicated by XRD and FTIR data were nearly reversed after the product was placed in hydrochloric acid (HCl), resulting in purified, exfoliated, thin hBN products.

  13. 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.

  14. Ferric sodium edetate therapy in children with iron deficiency anemia

    Directory of Open Access Journals (Sweden)

    Christie Moningkey

    2015-03-01

    Full Text Available Background Iron deficiency anemia (IDA is frequently found in school-aged children. The main treatments for IDA are overcoming the causal factors and iron supplementation. Noncompliance in taking iron tablets and the possibility of iron absorbtion or transport difficulties, can reduce efficacy of daily oral iron supplementation. Because excess iron storage in the intestinal cells can lead to mucosal blockage, twice weekly oral iron therapy may be considered instead of daily dosage. Objective To compare the effects of daily vs. twice weekly ferric sodium edetate (NaFeEDTA on hemoglobin (Hb, hematocrit (Ht, mean corpuscular volume (MCV, mean corpuscular hemoglobin (MCH, and mean corpuscular hemoglobin concentration (MCHC levels on children with IDA. Methods We conducted an open-label, randomized, prospective study in 36 children with IDA aged 5-11 years. Subjects were divided into two groups. For a one-month period, group I received daily iron therapy (NaFeEDTA and group II received twice weekly iron therapy. Examinations of Hb, Ht, MCV, MCH, MCHC were performed before and after iron therapy. Results There were no significant differences in Hb, Ht, MCV, MCH or MCHC levels after therapy between the daily and twice weekly NaFeEDTA groups (P > 0.05. Conclusion Twice weekly NaFeEDTA therapy is as effective as daily NaFeEDTA administration in children with IDA. [Paediatr Indones. 2015;55:91-4.].

  15. 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

  16. 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

  17. 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.

  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. 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.

  20. 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 ...

  1. 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...

  2. 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...

  3. 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,...

  4. 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

  5. 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 ...

  6. The Porphyromonas gingivalis ferric uptake regulator orthologue binds hemin and regulates hemin-responsive biofilm development.

    Directory of Open Access Journals (Sweden)

    Catherine A Butler

    Full Text Available Porphyromonas gingivalis is a Gram-negative pathogen associated with the biofilm-mediated disease chronic periodontitis. P. gingivalis biofilm formation is dependent on environmental heme for which P. gingivalis has an obligate requirement as it is unable to synthesize protoporphyrin IX de novo, hence P. gingivalis transports iron and heme liberated from the human host. Homeostasis of a variety of transition metal ions is often mediated in Gram-negative bacteria at the transcriptional level by members of the Ferric Uptake Regulator (Fur superfamily. P. gingivalis has a single predicted Fur superfamily orthologue which we have designated Har (heme associated regulator. Recombinant Har formed dimers in the presence of Zn2+ and bound one hemin molecule per monomer with high affinity (Kd of 0.23 µM. The binding of hemin resulted in conformational changes of Zn(IIHar and residue 97Cys was involved in hemin binding as part of a predicted -97C-98P-99L- hemin binding motif. The expression of 35 genes was down-regulated and 9 up-regulated in a Har mutant (ECR455 relative to wild-type. Twenty six of the down-regulated genes were previously found to be up-regulated in P. gingivalis grown as a biofilm and 11 were up-regulated under hemin limitation. A truncated Zn(IIHar bound the promoter region of dnaA (PGN_0001, one of the up-regulated genes in the ECR455 mutant. This binding decreased as hemin concentration increased which was consistent with gene expression being regulated by hemin availability. ECR455 formed significantly less biofilm than the wild-type and unlike wild-type biofilm formation was independent of hemin availability. P. gingivalis possesses a hemin-binding Fur orthologue that regulates hemin-dependent biofilm formation.

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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 ...

  15. 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, ...

  16. 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

  17. Sequence diversity and enzyme activity of ferric-chelate reductase LeFRO1 in tomato.

    Science.gov (United States)

    Kong, Danyu; Chen, Chunlin; Wu, Huilan; Li, Ye; Li, Junming; Ling, Hong-Qing

    2013-11-20

    Ferric-chelate reductase which functions in the reduction of ferric to ferrous iron on root surface is a critical protein for iron homeostasis in strategy I plants. LeFRO1 is a major ferric-chelate reductase involved in iron uptake in tomato. To identify the natural variations of LeFRO1 and to assess their effect on the ferric-chelate reductase activity, we cloned the coding sequences of LeFRO1 from 16 tomato varieties collected from different regions, and detected three types of LeFRO1 (LeFRO1(MM), LeFRO1(Ailsa) and LeFRO1(Monita)) with five amino acid variations at the positions 21, 24, 112, 195 and 582. Enzyme activity assay revealed that the three types of LeFRO1 possessed different ferric-chelate reductase activity (LeFRO1(Ailsa) > LeFRO1(MM) > LeFRO1(Monita)). The 112th amino acid residue Ala of LeFRO1 is critical for maintaining the high activity of ferric-chelate reductase, because modification of this amino acid resulted in a significant reduction of enzyme activity. Further, we showed that the combination of the amino acid residue Ile at the site 24 with Lys at the site 582 played a positive role in the enzyme activity of LeFRO1. In conclusion, the findings are helpful to understand the natural adaptation mechanisms of plants to iron-limiting stress, and may provide new knowledge to select and manipulate LeFRO1 for improving the iron deficiency tolerance in tomato.

  18. 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

  19. 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...

  20. A Versatile Strategy for Production of Membrane Proteins with Diverse Topologies: Application to Investigation of Bacterial Homologues of Human Divalent Metal Ion and Nucleoside Transporters.

    Science.gov (United States)

    Ma, Cheng; Hao, Zhenyu; Huysmans, Gerard; Lesiuk, Amelia; Bullough, Per; Wang, Yingying; Bartlam, Mark; Phillips, Simon E; Young, James D; Goldman, Adrian; Baldwin, Stephen A; Postis, Vincent L G

    2015-01-01

    Membrane proteins play key roles in many biological processes, from acquisition of nutrients to neurotransmission, and are targets for more than 50% of current therapeutic drugs. However, their investigation is hampered by difficulties in their production and purification on a scale suitable for structural studies. In particular, the nature and location of affinity tags introduced for the purification of recombinant membrane proteins can greatly influence their expression levels by affecting their membrane insertion. The extent of such effects typically depends on the transmembrane topologies of the proteins, which for proteins of unknown structure are usually uncertain. For example, attachment of oligohistidine tags to the periplasmic termini of membrane proteins often interferes with folding and drastically impairs expression in Escherichia coli. To circumvent this problem we have employed a novel strategy to enable the rapid production of constructs bearing a range of different affinity tags compatible with either cytoplasmic or periplasmic attachment. Tags include conventional oligohistidine tags compatible with cytoplasmic attachment and, for attachment to proteins with a periplasmic terminus, either tandem Strep-tag II sequences or oligohistidine tags fused to maltose binding protein and a signal sequence. Inclusion of cleavage sites for TEV or HRV-3C protease enables tag removal prior to crystallisation trials or a second step of purification. Together with the use of bioinformatic approaches to identify members of membrane protein families with topologies favourable to cytoplasmic tagging, this has enabled us to express and purify multiple bacterial membrane transporters. To illustrate this strategy, we describe here its use to purify bacterial homologues of human membrane proteins from the Nramp and ZIP families of divalent metal cation transporters and from the concentrative nucleoside transporter family. The proteins are expressed in E. coli in a

  1. 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.

  2. 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.

  3. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    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 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 significantly...

  4. 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

  5. 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

  6. 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.

  7. 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....

  8. 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... ferric EDTA, the iron in the compound interacts with hemocyanin, a copper-based respiratory protein...(3):807- 817. 9. National Cancer Institute. 1977. Bioassay of trisodium...

  9. 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.

  10. RATES OF HYDROUS FERRIC OXIDE CRYSTALLIZATION AND THE INFLUENCE ON COPRECIPITATED ARSENATE

    Science.gov (United States)

    Arsenate coprecipitated with hydrous ferric oxide (HFO) was stabilized against dissolution during transformation of HFO to more crystalline iron (hydr)oxides. The rate of arsenate stabilization approximately coincided with the rate of HFO transformation at pH 6 and 40 ?C. Compa...

  11. 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.

  12. Kinetics of H+ ion binding by the P+QA-state of bacterial photosynthetic reaction centers: rate limitation within the protein.

    Science.gov (United States)

    Maróti, P; Wraight, C A

    1997-01-01

    The kinetics of flash-induced H+ ion binding by isolated reaction centers (RCs) of Rhodobacter sphaeroides, strain R-26, were measured, using pH indicators and conductimetry, in the presence of terbutryn to block electron transfer between the primary and secondary quinones (QA and QB), and in the absence of exogenous electron donors to the oxidized primary donor, P+, i.e., the P+QA-state. Under these conditions, proton binding by RCs is to the protein rather than to any of the cofactors. After light activation to form P+QA-, the kinetics of proton binding were monoexponential at all pH values studied. At neutral pH, the apparent bimolecular rate constant was close to the diffusional limit for proton transfer in aqueous solution (approximately 10(11) M-1 s-1), but increased significantly in the alkaline pH range (e.g., 2 x 10(13) M-1 s-1 at pH 10). The average slope of the pH dependence was -0.4 instead of -1.0, as might be expected for a H+ diffusion-controlled process. High activation energy (0.54 eV at pH 8.0) and weak viscosity dependence showed that H+ ion uptake by RCs is not limited by diffusion. The salt dependence of the H+ ion binding rate and the pK values of the protonatable amino acid residues of the reaction center implicated surface charge influences, and Gouy-Chapman theory provided a workable description of the ionic effects as arising from modulation of the pH at the surface of the RC. Incubation in D2O caused small increases in the pKs of the protonatable groups and a small, pH (pD)-dependent slowing of the binding rate. The salt, pH, temperature, viscosity, and D2O dependences of the proton uptake by RCs in the P+QA- state were accounted for by three considerations: 1) parallel pathways of H+ delivery to the RC, contributing to the observed (net) H+ disappearance; 2) rate limitation of the protonation of target groups within the protein by conformational dynamics; and 3) electrostatic influences of charged groups in the protein, via the surface p

  13. Kinetics of H+ ion binding by the P+QA-state of bacterial photosynthetic reaction centers: rate limitation within the protein.

    Science.gov (United States)

    Maróti, P; Wraight, C A

    1997-07-01

    The kinetics of flash-induced H+ ion binding by isolated reaction centers (RCs) of Rhodobacter sphaeroides, strain R-26, were measured, using pH indicators and conductimetry, in the presence of terbutryn to block electron transfer between the primary and secondary quinones (QA and QB), and in the absence of exogenous electron donors to the oxidized primary donor, P+, i.e., the P+QA-state. Under these conditions, proton binding by RCs is to the protein rather than to any of the cofactors. After light activation to form P+QA-, the kinetics of proton binding were monoexponential at all pH values studied. At neutral pH, the apparent bimolecular rate constant was close to the diffusional limit for proton transfer in aqueous solution (approximately 10(11) M-1 s-1), but increased significantly in the alkaline pH range (e.g., 2 x 10(13) M-1 s-1 at pH 10). The average slope of the pH dependence was -0.4 instead of -1.0, as might be expected for a H+ diffusion-controlled process. High activation energy (0.54 eV at pH 8.0) and weak viscosity dependence showed that H+ ion uptake by RCs is not limited by diffusion. The salt dependence of the H+ ion binding rate and the pK values of the protonatable amino acid residues of the reaction center implicated surface charge influences, and Gouy-Chapman theory provided a workable description of the ionic effects as arising from modulation of the pH at the surface of the RC. Incubation in D2O caused small increases in the pKs of the protonatable groups and a small, pH (pD)-dependent slowing of the binding rate. The salt, pH, temperature, viscosity, and D2O dependences of the proton uptake by RCs in the P+QA- state were accounted for by three considerations: 1) parallel pathways of H+ delivery to the RC, contributing to the observed (net) H+ disappearance; 2) rate limitation of the protonation of target groups within the protein by conformational dynamics; and 3) electrostatic influences of charged groups in the protein, via the surface pH.

  14. 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.).

  15. Reaction mode between Si and Fe and evaluation of optimal species in poly-silicic-ferric coagulant

    Institute of Scientific and Technical Information of China (English)

    FU Ying; YU Shui-li; YU Yan-zhen; QIU Li-ping; HUI Ban

    2007-01-01

    A kind of Fe-polysilicate polymer, poly-silicic-ferric (PSF) coagulant was prepared by co-polymerization (hydroxylation of mixture of Fe3+ and fresh polysilicic acid (PS)), in which PSF0.5, PSF1 and PSF3 denotes Si/Fe molar ratio of 0.5, 1 and 3, respectively. The effects of Si/Fe ratio and reaction time (co-polymerization time or aging time) on the reaction mode between Si and Fe were studies, and the optimal species of PSF was evaluated by changing pH during the preparation of PSF and coagulation tests. The results showed that the characteristics of PSF are largely affected by both reaction time and Si/Fe ratio. PSF is found to be a essential complex of Si, Fe, and many other ions. The reaction mode between Si and Fe differs with various Si/Fe ratios. The pH of PSF0.5, PSF1 or PSF3 tended to be stable when reaction time 10, 25 or 55 min, respectively, which is almost consistent with the time reaching the relative stable morphology that is just the optimal species of higher coagulation efficiency. The optimal reaction time reaching optimal species can be evaluated by measuring the pH change during the polymerization process.

  16. Application of an M13 bacteriophage displaying tyrosine on the surface for detection of Fe(3+) and Fe(2+) ions.

    Science.gov (United States)

    Guo, Xiaohua; Niu, Chuncheng; Wu, Yunhua; Liang, Xiaosheng

    2015-12-01

    Ferric and ferrous ion plays critical roles in bioprocesses, their influences in many fields have not been fully explored due to the lack of methods for quantification of ferric and ferrous ions in biological system or complex matrix. In this study, an M13 bacteriophage (phage) was engineered for use as a sensor for ferric and ferrous ions via the display of a tyrosine residue on the P8 coat protein. The interaction between the specific phenol group of tyrosine and Fe(3+) / Fe(2+) was used as the sensor. Transmission electron microscopy showed aggregation of the tyrosine-displaying phages after incubation with Fe(3+) and Fe(2+). The aggregated phages infected the host bacterium inefficiently. This phenomenon could be utilized for detection of ferric and ferrous ions. For ferric ions, a calibration curve ranging from 200 nmol/L to 8 μmol/L with a detection limit of 58 nmol/L was acquired. For ferrous ions, a calibration curve ranging from 800 nmol/L to 8 μmol/L with a detection limit of 641.7 nmol/L was acquired. The assay was specific for Fe(3+) and Fe(2+) when tested against Ni(2+), Pb(2+), Zn(2+), Mn(2+), Co(2+), Ca(2+), Cu(2+), Cr(3+), Ba(2+), and K(+). The tyrosine displaying phage to Fe(3+) and Fe(2+) interaction would have plenty of room in application to biomaterials and bionanotechnology.

  17. 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...... biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life....

  18. [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

  19. Functional Analysis of the Ferric Uptake Regulator Gene fur in Xanthomonas vesicatoria.

    Directory of Open Access Journals (Sweden)

    Huiqin Liu

    Full Text Available Iron is essential for the growth and survival of many organisms. Intracellular iron homeostasis must be maintained for cell survival and protection against iron toxicity. The ferric uptake regulator protein (Fur regulates the high-affinity ferric uptake system in many bacteria. To investigate the function of the fur gene in Xanthomonas vesicatoria (Xv, we generated a fur mutant strain, fur-m, by site-directed mutagenesis. Whereas siderophore production increased in the Xv fur mutant, extracellular polysaccharide production, biofilm formation, swimming ability and quorum sensing signals were all significantly decreased. The fur mutant also had significantly reduced virulence in tomato leaves. The above-mentioned phenotypes significantly recovered when the Xv fur mutation allele was complemented with a wild-type fur gene. Thus, Fur either negatively or positively regulates multiple important physiological functions in Xv.

  20. 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.

  1. 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.

  2. Biohydrometallurgical process to produce the coagulant ferric sulfate from the pyrite present in coal tailings

    Energy Technology Data Exchange (ETDEWEB)

    Colling, A.V.; Santos Menezes dos, J.C.S.; Silveira, P.S.; Schneider, I.A.H. [South Rio Grande Federal Univ., Porto Alegre (Brazil). Graduate Program in Mining, Metallurgical and Materials Technology Center

    2010-07-01

    This paper presented details of a biohydrometallurgical study conducted to characterize the production of a ferric sulfate coagulate from pyrite (FeS{sub 2}) contained in coal tailings. Leaching experiments were conducted with coal tailings samples from the Santa Catarina mining site in Brazil. The experiments were conducted for sterile and non-sterile samples, as well as samples inoculated with acidophilic bacteria and acidophilic bacteria with the addition of nutrients. Samples were collected weekly in order to analyze total iron, sulfate, and the amounts of Acidithiobacillus ferroxidans bacteria. An analysis of the samples showed that the pyrite oxidation, iron sulfate production, and quantities of bacteria were higher in the column inoculated with the bacteria and nutrient additions. The samples produced an aqueous solution that was rich in ferric sulfate. Water treatment tests demonstrated that the resulting coagulant is as efficient as conventionally-produced coagulants. 8 refs., 2 tab., 2 figs.

  3. [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

  4. 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...

  5. 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.

  6. Isolation of Trichoderma harzianum (Rifai) growing on ferric hydroxide mud impregnated with gas oil

    Energy Technology Data Exchange (ETDEWEB)

    Gudin, C. (Lavera Refinery, France); Chater, K.W.A.

    1977-09-01

    In northern France, gas oil-impregnated ferric hydroxide mud was found to support fungal growth. The fungus was identified by the Commonwealth Mycological Institute, Kew, with whom a reference culture has been registered. Experiments indicated that its growth resulted from the biodegradation of the gas oil. It is believed that, in this unusual situation, contaminating hydrocarbons may be removed from the environment by microbial activity.

  7. 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 ...

  8. Size fractionation characterisation of removed organics in reverse osmosis concentrates by ferric chloride.

    Science.gov (United States)

    Bagastyo, A Y; Keller, J; Batstone, D J

    2011-01-01

    Reverse osmosis membrane separation is the leading method for manufacturing potable purified water. It also produces a concentrate stream, namely reverse osmosis concentrates (ROC), with 10-20% of the water, and almost all other compounds. One method for further treating this stream is by coagulation with ferric chloride. This study evaluates removed organics in ROC treated with ferric chloride. Fractionation with ultrafiltration membranes allows separation of organics based on a nominal molecular weight. A stirred cell system was applied for serial fractionation to classify organic compounds into six groups of 10 kDa. The study found that raw ROC is rich in low molecular weight compounds (organics. These compounds include soluble microbial products (SMPs) and smaller humic and fulvic acids as indicated by fluorescence scanning. Conversely, colour was mostly contributed by medium to large molecules of humic and fulvic acids (> 0.5 kDa). Organics and colour were reduced in all molecular groups at an optimum treatment dose 1.48 mM FeCl3 and a pH of 5. However, ferric seemed to effectively remove colour in all size ranges while residual nitrogen was found mostly in the < 1 kDa sizes. Further, the fluorescence indicated that larger humic and fulvic acids were removed with considerable SMPs remaining in the < 0.5 kDa.

  9. 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

  10. 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

  11. Experimental determination of the phase boundary between kornelite and pentahydrated ferric sulfate at 0.1MPa

    Science.gov (United States)

    Kong, W.G.; Wang, A.; Chou, I.-Ming

    2011-01-01

    Recent findings of various ferric sulfates on Mars emphasize the importance of understanding the fundamental properties of ferric sulfates at temperatures relevant to that of Martian surface. In this study, the phase boundary between kornelite (Fe2(SO4)3.7H2O) and pentahydrated ferric sulfate (Fe2(SO4)3.5H2O) was experimentally determined using the humidity-buffer technique together with gravimetric measurements and Raman spectroscopy at 0.1MPa in the 36-56??C temperature range. Through the thermodynamic analysis of our experimental data, the enthalpy change (-290.8??0.3kJ/mol) and the Gibbs free energy change (-238.82??0.02kJ/mol) for each water molecule of crystallization in the rehydration of pentahydrated ferric sulfate to kornelite were obtained. ?? 2011 Elsevier B.V.

  12. 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

  13. Comparative study of intravenous iron sucrose versus ferric carboxymaltose for the treatment of iron deficiency anemia in postpartum patients

    Directory of Open Access Journals (Sweden)

    Kishorkumar Vitthal Hol

    2015-06-01

    Conclusions: Fixed dose iron sucrose and ferric carboxymaltose are equally effective and safe for the treatment of iron deficiency anemia in postpartum patients. [Int J Reprod Contracept Obstet Gynecol 2015; 4(3.000: 669-673

  14. 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.

  15. Bacterial Hydrodynamics

    Science.gov (United States)

    Lauga, Eric

    2016-01-01

    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 micrometer 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, I review the biomechanics of bacterial motility and look ahead to future challenges.

  16. 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.

  17. Electrospray ionization collision-induced dissociation mass spectrometry: a tool to characterize synthetic polyaminocarboxylate ferric chelates used as fertilizers.

    Science.gov (United States)

    Orera, Irene; Orduna, Jesús; Abadía, Javier; Alvarez-Fernández, Ana

    2010-01-01

    Fertilizers based on synthetic polyaminocarboxylate ferric chelates have been known since the 1950s to be successful in supplying Fe to plants. In commercial Fe(III)-chelate fertilizers, a significant part of the water-soluble Fe-fraction consists of still uncharacterized Fe byproducts, whose agronomical value is unknown. Although collision-induced dissociation (CID) tandem mass spectrometry (MS/MS) is a valuable tool for the identification of such compounds, no fragmentation data have been reported for most Fe(III)-chelate fertilizers. The aim of this study was to characterize the CID-MS(2) fragmentation patterns of the major synthetic Fe(III)-chelates used as Fe-fertilizers, and subsequently use this technique for the characterization of commercial fertilizers. Quadrupole-time-of-flight (QTOF) and spherical ion trap mass analyzers equipped with an electrospray ionization (ESI) source were used. ESI-CID-MS(2) spectra obtained were richer when using the QTOF device. Specific differences were found among Fe(III)-chelate fragmentation patterns, even in the case of positional isomers. The analysis of a commercial Fe(III)-chelate fertilizer by high-performance liquid chromatography (HPLC) coupled to ESI-MS(QTOF) revealed two previously unknown, Fe-containing compounds, that were successfully identified by a comprehensive comparison of the ESI-CID-MS(2)(QTOF) spectra with those of pure chelates. This shows that HPLC/ESI-CID-MS(2)(QTOF), along with the Fe(III)-chelate fragmentation patterns, could be a highly valuable tool to directly characterize the water-soluble Fe fraction in Fe(III)-chelate fertilizers. This could be of great importance in issues related to crop Fe-fertilization, both from an agricultural and an environmental point of view.

  18. Optical and electrical properties of thin films of bismuth ferric oxide; Propiedades opticas y electricas de peliculas delgadas de oxido de bismuto ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Cardona R, D.

    2014-07-01

    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 Fe{sub 2}O{sub 3}) 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 BiFeO{sub 3} 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 BiFeO{sub 3} composition. These samples showed a secondary phase (Bi{sub 2}5FeO{sub 4}0 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-Fe{sub 2}O{sub 3}) 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Kivelitz, D.; Taupitz, M.; Hamm, B. [Universitaetsklinikum Charite, Berlin (Germany). Inst. fuer Radiologie; Gehl, H.B. [Medizinische Univ. Luebeck (Germany). Inst. fuer Radiologie; Heuck, A. [Muenchen Univ. (Germany). Radiologische Klinik; Krahe, T. [Koeln Univ. (Germany). Inst. fuer Radiologische Diagnostik; Lodemann, K.P. [Bracco-Byk Gulden GmbH, Konstanz (Germany)

    1999-07-01

    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.)

  20. Arsenate sorption by hydrous ferric oxide incorporated onto granular activated carbon with phenol formaldehyde resins coating.

    Science.gov (United States)

    Zhuang, J M; Hobenshield, E; Walsh, T

    2008-04-01

    A simple and effective method was developed using phenol formaldehyde (PF) resins to immobilize hydrous ferric oxide (HFO) onto granular activated carbon (GAC). The resulting sorbent possesses advantages for both the ferric oxide and the GAC, such as a great As-affinity of ferric oxide, large surface area of GAC, and enhanced physical strength. The studies showed that within one hour this sorbent was able to remove 85% of As(V) from water containing an initial As(V) concentration of 1.74 mg l(-1). The As(V) adsorption onto the sorbent was found to follow a pseudo-second order kinetics model. The adsorption isotherms were interpreted in terms of the Langmuir and Freundlich models. The equilibrium data fitted very well to both models. Column tests showed that this sorbent was able to achieve residual concentrations of As(V) in a range of 0.1-2.0 microg l(-1) while continuously treating about 180 bed volume (BV, 130 ml-BV) of arsenate water with an initial As(V) concentration of 1886 microg l(-1) at a filtration rate of 13.5 ml min(-1), i.e., an empty bed contact time (EBCT) of 9.6 min and a gram sorbent contact time (GSCT) of 0.15 min. After passing 635 BV of arsenate water, the exhausted sorbent was then tested by the Toxicity Characteristic Leaching Procedure (TCLP, US EPA Method 1311) test, and classified as non-hazardous for disposal. Hence, this HFO-PF-coated GAC has the capability to remove As(V) from industrial wastewater containing As(V) levels of about 2 mg l(-1).

  1. 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.

  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. 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.

  4. 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...

  5. 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...

  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. Chlorinated aromatic compounds in a thermal process promoted by oxychlorination of ferric chloride.

    Science.gov (United States)

    Fujimori, Takashi; Takaoka, Masaki; Morisawa, Shinsuke

    2010-03-15

    The relationship between the formation of chlorinated aromatic (aromatic-Cl) compounds and ferric chloride in the solid phase during a thermal process motivated us to study the chemical characteristics of iron in a model solid sample, a mixture of FeCl(3) x 6H(2)O, activated carbon, and boron nitride, with increasing temperature. Fe K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy revealed drastic changes in the chemical form of amorphous iron, consistent with other analytical methods, such as X-ray diffraction using synchrotron radiation (SR-XRD) and Fourier-transform infrared (FT-IR) spectroscopy. Atomic-scale evidence of the chlorination of aromatic carbon was detected by Cl-K X-ray absorption near edge structure (XANES) spectroscopy. These results showed the thermal formation mechanism of aromatic-Cl compounds in the solid phase with ferric chloride. We attribute the formation of aromatic-Cl compounds to the chlorination of carbon, based on the oxychlorination reaction of FeCl(3) at temperatures in excess of ca. 300 degrees C, when the carbon matrix is activated by carbon gasification, catalyzed by Fe(2)O(3), and surface oxygen complexes (SOC) generated by a catalytic cycle of FeCl(2) and FeOCl. Chemical changes of trace iron in a thermal process may offer the potential to generate aromatic-Cl compounds in the solid phase.

  8. Arsenic and antimony removal from drinking water by adsorption on granular ferric oxide.

    Science.gov (United States)

    Sazakli, Eleni; Zouvelou, Stavroula V; Kalavrouziotis, Ioannis; Leotsinidis, Michalis

    2015-01-01

    Arsenic and antimony occur in drinking water due to natural weathering or anthropogenic activities. There has been growing concern about their impact on health. The aim of this study was to assess the efficiency of a granular ferric oxide adsorbent medium to remove arsenic and antimony from drinking water via rapid small-scale column tests (RSSCTs). Three different water matrices - deionized, raw water treated with a reverse osmosis domestic device and raw water - were spiked with arsenic and/or antimony to a concentration of 100 μg L⁻¹. Both elements were successfully adsorbed onto the medium. The loadings until the guideline value was exceeded in the effluent were found to be 0.35-1.63 mg g⁻¹ for arsenic and 0.12-2.11 mg g⁻¹ for antimony, depending on the water matrix. Adsorption of one element was not substantially affected by the presence of the other. Aeration did not affect significantly the adsorption capacity. Granular ferric oxide could be employed for the simultaneous removal of arsenic and antimony from drinking water, whereas full-scale systems should be assessed via laboratory tests before their implementation.

  9. Characterization and coagulation performance of polymeric phosphate ferric sulfate on eutrophic water

    Institute of Scientific and Technical Information of China (English)

    焦世珺; 郑怀礼; 陈容; 邓小莉; 邓琳莉; 吉方英

    2009-01-01

    Polymeric phosphate ferric sulfate (PPFS),a new improved coagulation reagent,was prepared by polymeric ferric sulfate (PFS),Na2HPO4 and NaOH. The degree of iron polymerisation (Fepol) of PPFS was determined by means of the ferron-timed spectroscopy method. Furthermore,the effect of n(P)/n(Fe),alkalization degree,pH value,and PPFS dosage on the removal rate of eutrophic water turbidity and chl-a and ζ-potential of products were also investigated. The experimental results show that the best n(P)/n(Fe) of flocculation effect in stable product of PFFS is 0.3; the best alkalization degree of flocculation effect is 0.2,while the n(P)/n(Fe) is 0.3. Under the neutral and subalkalic (pH value is 7-8) conditions,PPFS achieves the best processing efficiency. PPFS has more excellent turbidity and higher chlorophyl removal rate by studying treatment eutrophic water in comparison with PFS.

  10. Treatment of wastewater phosphate by reductive dissolution of iron: use of ferric oxyhydroxide media.

    Science.gov (United States)

    Robertson, W D; Lombardo, P S

    2011-01-01

    In smaller wastewater treatment systems such as septic systems, there is an interest in the development of passive phosphorus (P) removal methods. This study tested fixed-bed filters containing ferric oxyhydroxide media for wastewater P removal in a laboratory column test and in a full-scale domestic septic system. In the column test, during 30 mo of dosing with domestic wastewater, reductive iron dissolution reactions delivered consistent moderate concentrations of Fe into solution (2.9 ± 1.6 mg L), and influent PO-P of 3.7 ± 1.0 mg L was attenuated to 0.09 + 0.04 mg L in the column effluent (98% removal). Phosphorus breakthrough at successive locations along the column indicated that in addition to sorption, mineral precipitation reactions probably also played an important role in the observed P attenuation. This was supported by electron microprobe analyses, which showed the presence of thick (20 μm) secondary Fe-rich coatings containing P on the primary ferric media grains. Assays of NaHCO-leachable and acid-extractable P on the column solids showed accumulation of up to 5.4 mg g acid-extractable P near the column inlet, but iron filters could be attractive options for P removal in smaller wastewater systems because of their passive nature.

  11. 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.

  12. 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

  13. 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.

  14. Study of the Catalytic Synthesis of Isoamyl Hexanoate with Ferric Chloride%氯化铁催化合成己酸异戊脂的研究

    Institute of Scientific and Technical Information of China (English)

    林进; 王兰芝

    2000-01-01

    It has been found that ferric chloride is superior to H2SO4 when used as catalyst for esterificatiou of isoamyl alcohol with hexauoic acid. The optimum reaction conditions in synthesis of isoamyl hexanoate catalyzed with ferric chloride are determined,with the yield at 87. 65%.

  15. Reactions of metal ions at surfaces of hydrous iron oxide

    Science.gov (United States)

    Hem, J.D.

    1977-01-01

    Cu, Ag and Cr concentrations in natural water may be lowered by mild chemical reduction involving ferric hydroxide-ferrous ion redox processes. V and Mo solubilities may be controlled by precipitation of ferrous vanadate or molybdate. Concentrations as low as 10-8.00 or 10-9.00 M are readily attainable for all these metals in oxygen-depleted systems that are relatively rich in Fe. Deposition of manganese oxides such as Mn3O4 can be catalyzed in oxygenated water by coupling to ferrous-ferric redox reactions. Once formed, these oxides may disproportionate, giving Mn4+ oxides. This reaction produces strongly oxidizing conditions at manganese oxide surfaces. The solubility of As is significantly influenced by ferric iron only at low pH. Spinel structures such as chromite or ferrites of Cu, Ni, and Zn, are very stable and if locally developed on ferric hydroxide surfaces could bring about solubilities much below 10-9.00 M for divalent metals near neutral pH. Solubilities calculated from thermodynamic data are shown graphically and compared with observed concentrations in some natural systems. ?? 1977.

  16. 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

  17. [Pathway of aqueous ferric hydroxide catalyzed ozone decomposition and ozonation of trace nitrobenzene].

    Science.gov (United States)

    Ma, Jun; Zhang, Tao; Chen, Zhong-lin; Sui, Ming-hao; Li, Xue-yan

    2005-03-01

    In this paper, the decomposition rate of ozone in water was measured over GAC and ferric hydroxide/GAC (FeOOH/GAC) catalyst and the mechanism of ozone catalytic decomposition was discussed. The catalytic ozonation activity of trace nitrobenzene in water was determined on several metal oxides and correlated with their surface density of hydroxyl groups and pHzpc,(pH of zero point of charge). The results show that: 1) The pseudo-first order rate of ozone decomposition increased by 68 and 108 percent for GAC and FeOOH/GAC catalysts respectively; 2) When t-butanol was added, the rate constant decreased by 9 % for GAC and 20% for FeOOH/GAC; 3) There was no direct correlation between surface density of hydroxyl groups and the activity of catalytic ozonation of nitrobenzene; 4) The oxide surface at nearly zero charged point was favorable for the catalytic ozonation of nitrobenzene.

  18. Drug insight: Safety of intravenous iron supplementation with sodium ferric gluconate complex.

    Science.gov (United States)

    Michael, Beckie; Fishbane, Steven; Coyne, Daniel W; Agarwal, Rajiv; Warnock, David G

    2006-02-01

    Intravenous iron is necessary for optimal management of anemia in patients receiving hemodialysis and is utilized in the majority of these patients in the US. The availability of nondextran formulations of intravenous iron has significantly improved the safety of its use. The nondextran iron formulation sodium ferric gluconate complex (SFGC) has been extensively studied in the hemodialysis population, with two large phase IV trials documenting its safety. SFGC is efficacious and, at recommended doses, is associated with a low incidence of adverse events. There have been few comparative studies of the nondextran intravenous iron preparations; however, they are known to have different pharmacokinetic characteristics. There is also evidence to indicate that these compounds differ in terms of their cytotoxic and proinflammatory properties, and their propensity to induce oxidative stress. This paper reviews the current literature on the safety of SFGC and examines the emerging safety issues surrounding the use of intravenous iron.

  19. 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.

  20. 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.

  1. 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 .

  2. Sorption of ferric iron from ferrioxamine B to synthetic and biogenic layer type manganese oxides

    Science.gov (United States)

    Duckworth, Owen W.; Bargar, John R.; Sposito, Garrison

    2008-07-01

    Siderophores are biogenic chelating agents produced in terrestrial and marine environments that increase the bioavailability of ferric iron. Recent work has suggested that both aqueous and solid-phase Mn(III) may affect siderophore-mediated iron transport, but scant information appears to be available about the potential roles of layer type manganese oxides, which are relatively abundant in soils and the oligotrophic marine water column. To probe the effects of layer type manganese oxides on the stability of aqueous Fe-siderophore complexes, we studied the sorption of ferrioxamine B [Fe(III)HDFOB +, an Fe(III) chelate of the trihydroxamate siderophore desferrioxamine B (DFOB)] to two synthetic birnessites [layer type Mn(III,IV) oxides] and a biogenic birnessite produced by Pseudomonas putida GB-1. We found that all of these predominantly Mn(IV) oxides greatly reduced the aqueous concentration of Fe(III)HDFOB + at pH 8. Analysis of Fe K-edge EXAFS spectra indicated that a dominant fraction of Fe(III) associated with the Mn(IV) oxides is not complexed by DFOB as in solution, but instead Fe(III) is specifically adsorbed to the mineral structure at multiple sites, thus indicating that the Mn(IV) oxides displaced Fe(III) from the siderophore complex. These results indicate that layer type manganese oxides, including biogenic minerals, may sequester iron from soluble ferric complexes. We conclude that the sorption of iron-siderophore complexes may play a significant role in the bioavailability and biogeochemical cycling of iron in marine and terrestrial environments.

  3. 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

  4. 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 ...

  5. 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.

  6. 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

    2015-06-12

    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.

  7. Effect of ionic strength on ligand exchange kinetics between a mononuclear ferric citrate complex and siderophore desferrioxamine B

    Science.gov (United States)

    Ito, Hiroaki; Fujii, Manabu; Masago, Yoshifumi; Waite, T. David; Omura, Tatsuo

    2015-04-01

    The effect of ionic strength (I) on the ligand exchange reaction between a mononuclear ferric citrate complex and the siderophore, desferrioxamine B (DFB), was examined in the NaCl concentration range of 0.01-0.5 M, particularly focusing on the kinetics and mechanism of ligand exchange under environmentally relevant conditions. Overall ligand exchange rate constants were determined by spectrophotometrically measuring the time course of ferrioxamine B formation at a water temperature of 25 °C, pH 8.0, and citrate/Fe molar ratios of 500-5000. The overall ligand exchange rate decreased by 2-11-fold (depending on the citrate/Fe molar ratios) as I increased from approximately 0.01 to 0.5 M. In particular, a relatively large decrease was observed at lower I (dissociation of citrate from the parent complexes) dominates in ferrioxamine formation under the experimental conditions used. The model also predicts that the higher rate of ligand exchange at lower I is associated with the decrease in the ferric dicitrate complex stability because of the relatively high electrical repulsion between ferric monocitrate and free citrate at lower I (note that the reactivity of ferric dicitrate with DFB is smaller than that for the monocitrate complex). Overall, the findings of this study contribute to the understanding of the potential effect of I on ligand exchange kinetics in natural waters and provide fundamental knowledge on iron transformation and bioavailability.

  8. Comparison of Formocresol and Ferric Sulfate Pulpotomy in Primary Molars: A Systematic Review and Meta-analysis

    Directory of Open Access Journals (Sweden)

    M. Fallahinejad Ghajari

    2009-03-01

    Full Text Available Objective: Several studies have compared ferric sulfate and formocresol pulpotomy in primary molars. The results of these studies, however, could not be compared due to differencesin evaluated outcomes (clinical, radiographic, or histologic and follow up duration.The aim of the present study was a systematic review of similar studies and a metaanalysis of their results to provide the latest evidence on the issue.Materials and Methods: Web-based search was done in EMBASE,Cochrane, Pubmed,Google Scholar, IranMedex, Scientific Citation Index (SCI, and Scopus index databases.A hand search also was conducted in scientific and research dental journals approved by the Ministry of Health and Medical Education of Iran. Eight randomized clinical trial articles were selected. Clinical success, clinical and radiographic success (total success rate were assessed as outcome variables. Peto test served for data analysis.Results: The clinical success of formocresol pulpotomy was comparable to that of ferric sulfate (P=0.574. In addition, the difference between total success rate of the two methods in different studies was insignificant (P=0.42.Conclusion: No significant difference existed between the total success rate of formocresol and ferric sulfate pulpotomy, and ferric sulfate can be an appropriate alternative for formocresol.

  9. 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

  10. Pyrite formation and mineral transformation pathways upon sulfidation of ferric hydroxides depend on mineral type and sulfide concentration

    NARCIS (Netherlands)

    Peiffer, Stefan; Behrends, Thilo; Hellige, Katrin; Larese-Casanova, Philip; Wan, Moli; Pollok, Kilian

    2015-01-01

    The reaction of ferric (hydr)oxides with dissolved sulfide does not lead to the instantaneous production of thermodynamically stable products but can induce a variety of mineral transformations including the formation of metastable intermediates. The importance of the various transformation pathways

  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. Research progress of arsenic removal technology by ferric salt%铁盐除砷技术研究进展

    Institute of Scientific and Technical Information of China (English)

    张志斌; 李锦祥; 边兴玉; 魏垒垒; 郭宁彬; 王志俊

    2012-01-01

    基于砷是一种自然界普遍存在的有毒元素,砷污染已成为一个亟待解决的全球性的环境问题.围绕低分子类铁盐、高分子类铁盐及其它铁类化合物三个方面综述了当前铁盐除砷技术的研究进展.结果表明:(1)铁盐除砷技术具有除砷效果好、经济、操作简单等优点;(2)研制高效、价成本、低能耗的除砷铁盐药剂以及多种药剂的联合使用将成为今后铁盐除砷技术的发展方向.%Arsenic is a prevalent toxic element in nature and the treatment of water with arsenic pollution has become a global environmental problem. The study introduces the technology of arsenic removal by ferric salt from the aspects of low molecular ferric salts, high molecular ferric salts and other iron species. The results show: (1) the technology of arsenic removal by feme salt has many advantages, such as higher removal efficiency, economy, simple operation and so on; (2)developing the ferric salts with high efficiency, low cost and low energy consumption and combined use of several chemicals will be the development direction of the technology of arsenic removal by ferric salt.

  13. Microbial Degradation of Aniline by Bacterial Consortium

    Institute of Scientific and Technical Information of China (English)

    JIAN-LONG WANG; ZE-YU MAO; WEI-ZHONG WU

    2003-01-01

    Objective To investigate the characteristics of microbial degradation of aniline by a stable bacterial consortium. Methods The bacterial consortium was isolated from activated sludge treating chemical wastewater using aniline as the sole source of carbon and nitrogen by enrichment and isolation technique. The biomass was measured as optical density (OD) at 510 nm using a spectrophotometer. Aniline concentrations were determined by spectrophotometer. The intermediates of aniline degradation were identified by GC/MS method. Results The bacterial consortium could grow at a range of aniline concentrations between 50 and 500 mg/L. The optimal pH and temperature for aniline degradation were determined to be 7.0 and 30, respectively. The presence of NH4NO3 as an additional nitrogen source (100-500 mg/L) had no adverse effect on bacterial growth and aniline degradation. The presence of heavy metal ions, such as Co2+, Zn2+, Ni2+, Mn2+ and Cu2+ had an inhibitory effect on aniline degradation. Conclusions The isolated bacterial consortium candegrade aniline up to 500 mg/L effectively and tolerate some heavy metal ions that commonly exist in chemical wastewater. It has a potential to be applied in the practical treatment of aniline-containingwastewater.

  14. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

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

    2010-01-01

    that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... 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 become...

  15. Inhibiting bacterial toxins by channel blockage.

    Science.gov (United States)

    Bezrukov, Sergey M; Nestorovich, Ekaterina M

    2016-03-01

    Emergent rational drug design techniques explore individual properties of target biomolecules, small and macromolecule drug candidates, and the physical forces governing their interactions. In this minireview, we focus on the single-molecule biophysical studies of channel-forming bacterial toxins that suggest new approaches for their inhibition. We discuss several examples of blockage of bacterial pore-forming and AB-type toxins by the tailor-made compounds. In the concluding remarks, the most effective rationally designed pore-blocking antitoxins are compared with the small-molecule inhibitors of ion-selective channels of neurophysiology.

  16. 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.

  17. 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)

  18. 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

  19. 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

  20. 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

  1. Real-time monitoring of arsenic filtration by granular ferric hydroxide.

    Science.gov (United States)

    Fleming, David E B; Eddy, Isadel S; Gherase, Mihai R; Gibbons, Meaghan K; Gagnon, Graham A

    2010-01-01

    Contamination of drinking water by arsenic is a serious public health issue in many parts of the world. One recent approach to this problem has been to filter out arsenic by use of granular ferric hydroxide (GFH), an adsorbent developed specifically for the selective removal of arsenic from water. Previous studies have documented the efficiency and high treatment capacity of this approach. We present a novel X-ray fluorescence method to monitor the accumulation of arsenic within a specially designed GFH column, as both a function of time (or water volume) and location along the column. Using a miniature X-ray tube and silicon PiN diode detector, X-ray fluorescence is used to detect characteristic X-rays of arsenic excited from within the GFH. Trials were performed using a water flow rate of approximately 1.5 L per hour, with an added arsenic concentration of approximately 1000 microg per litre. In this paper, trial results are presented and potential applications described. PMID:19850486

  2. Differential responses of soil nematode community to pig manure application levels in Ferric Acrisols

    Science.gov (United States)

    Yang, Yi-Ru; Li, Xiao-Gang; Zhou, Zhi-Gao; Zhang, Tao-Lin; Wang, Xing-Xiang

    2016-01-01

    Excessive pig manure application probably degrades arable soil quality in some intensive pig farming areas. The responses of the nematode community to dosages of pig manure were investigated in Ferric Acrisols under 3-season peanut monoculture. Varying dosages of manure (1.75, 3.5, 7, 14 and 28 t·ha−1·yr−1) in combination with chemical fertilizer were applied to field plots, and chemical fertilizer alone was also applied as a control. With increasing manure application, the abundance of bacterivores and omnivores-predators increased, the abundance of plant parasites decreased, and fungivores abundance exhibited hump-shaped variation. Simpson diversity index and plant parasite index/maturity index of the nematode communities increased to a maximum level at a manure application rate of 3.5 t·ha−1·yr−1 and then sharply decreased. The changes in the soil nematode community were further determined to be correlated with chemical properties; available phosphorus had the strongest quadratic correlation with the two indices, implying that available phosphorus had a better indicative effect than other soil properties to nematode community. Available phosphorus in soil was deduced from 49 to 64 mg·kg−1 with the best nematode communities. Our results emphasized the importance of regular applications of manure in agriculture field to balance nematode diversity and build healthy agro-ecosystems. PMID:27734955

  3. 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

  4. Ferric Carboxymaltose-Mediated Attenuation of Doxorubicin-Induced Cardiotoxicity in an Iron Deficiency Rat Model

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Toblli

    2014-01-01

    Full Text Available Since anthracycline-induced cardiotoxicity (AIC, a complication of anthracycline-based chemotherapies, is thought to involve iron, concerns exist about using iron for anaemia treatment in anthracycline-receiving cancer patients. This study evaluated how intravenous ferric carboxymaltose (FCM modulates the influence of iron deficiency anaemia (IDA and doxorubicin (3–5 mg per kg body weight [BW] on oxidative/nitrosative stress, inflammation, and cardiorenal function in spontaneously hypertensive stroke-prone (SHR-SP rats. FCM was given as repeated small or single total dose (15 mg iron per kg BW, either concurrent with or three days after doxorubicin. IDA (after dietary iron restriction induced cardiac and renal oxidative stress (markers included malondialdehyde, catalase, Cu,Zn-superoxide dismutase, and glutathione peroxidase, nitrosative stress (inducible nitric oxide synthase and nitrotyrosine, inflammation (tumour necrosis factor-alpha and interleukin-6, and functional/morphological abnormalities (left ventricle end-diastolic and end-systolic diameter, fractional shortening, density of cardiomyocytes and capillaries, caveolin-1 expression, creatinine clearance, and urine neutrophil gelatinase-associated lipocalin that were aggravated by doxorubicin. Notably, iron treatment with FCM did not exacerbate but attenuated the cardiorenal effects of IDA and doxorubicin independent of the iron dosing regimen. The results of this model suggest that intravenous FCM can be used concomitantly with an anthracycline-based chemotherapy without increasing signs of AIC.

  5. 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.

  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.

  7. Assessment of fertility status of Ferric Acrisols in the humid area of Nigeria

    Directory of Open Access Journals (Sweden)

    M. A. Nwachokor

    2013-09-01

    Full Text Available The study assessed the fertility status of Ferric Acrisols in the humid area of Nigeria. The objectives of the study were to provide data on the physical and chemical properties of the soils and to identify any constraints inherent in them that could adversely affect their productivity. Subsequently, appropriate measures to adequately ameliorate the constraints were recommended so as to enhance the fertility status and the overall productive potentials of the soils for upland crops. Among the fertility constraints identified were low effective cation exchange capacity and soil acidification. In addition, the clayey texture of the subsoil made these soils susceptible to erosion as well as caused harvesting difficulties. Liming was recommended to ameliorate the acidity constraints. Liming together with incorporation of organic materials into the soils were the measures needed to enhance their effective cation exchange capacity. Soil erosion control was to be given high priority especially by maintaining adequate surface cover and ensuring that tillage was limited to only when soil was drier than the plastic limit.

  8. [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

  9. The effect of solids residence time on phosphorus adsorption to hydrous ferric oxide floc.

    Science.gov (United States)

    Conidi, Daniela; Parker, Wayne J

    2015-11-01

    The impact of solids residence time (SRT) on phosphate adsorption to hydrous ferric oxide (HFO) floc when striving for ultra-low P concentrations was characterized and an equilibrium model that describes the adsorption of P onto HFO floc of different ages was developed. The results showed that fresh HFO had a higher adsorption capacity in comparison to aged (2.8, 7.4, 10.8 and 22.8 days) HFO and contributed substantially to P removal at steady state. P adsorption onto HFO solids was determined to be best described by the Freundlich isotherm. P desorption from HFO solids was negligible supporting the hypothesis that chemisorption is the mechanism of P adsorption on HFO solids. A model that included the contribution of different classes of HFO solids (i.e. High, Low or Old, containing high concentration, low concentration or no active surface sites, respectively) to adsorption onto HFO from a sequencing batch reactor (SBR) system was found to adequately describe P adsorption onto HFO solids of different ages. From the model it was determined that the fractions of High and Low HFO decreased with SRT while the fraction of Old HFO increased with SRT. The transformation of High HFO to Low HFO did not limit the overall production of Old HFO and the fresh HFO solids contributed more to P removal at steady state than the aged solids.

  10. 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

  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. 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

  13. Selection of substrate recognition sequence of protein kinase with ferric chelation affinity chromatography

    Institute of Scientific and Technical Information of China (English)

    陈长征; 夏其昌; 李伯良; 王应睐

    1997-01-01

    Protein kinase substrate phage (PKS phage) was constructed by fusing the substrate recognition consensus sequence of cAMP-dependent protein kinase (cAPK) with bacteriophage minor coat protein g3p and by dis-playing it on the surface of filamentous bacteriophage fd. Phosphorylation in vitro by cAPK showed a unique labelled band of approximately 60 ku, which was consistent with the molecular weight of the PKS-g3p fusion protein. Some weakly phosphorylated bands for both PKS phage and wild-type phage were also observed. Phage display random 15-mer peptide library phosphorylated by cAPK was selected with ferric (Fe3+ ) chelalion affinity resin. After 4 rounds of screening, phage clones were picked out to determine the displayed peptide sequences by DNA sequencing. The results showed that 5 of 14 sequenced phages displayed the cAPK recognition sequence motif (R)RXS/T. Their in vitro phosphorylation analyses revealed the specific labelled bands corresponding to the positive PKS phages with and without the typ

  14. Kinetic and thermodynamic aspects of adsorption of arsenic onto granular ferric hydroxide (GFH).

    Science.gov (United States)

    Banerjee, Kashi; Amy, Gary L; Prevost, Michele; Nour, Shokoufeh; Jekel, Martin; Gallagher, Paul M; Blumenschein, Charles D

    2008-07-01

    Relatively limited information is available regarding the impacts of temperature on the adsorption kinetics and equilibrium capacities of granular ferric hydroxide (GFH) for arsenic (V) and arsenic (III) in an aqueous solution. In general, very little information is available on the kinetics and thermodynamic aspects of adsorption of arsenic compounds onto other iron oxide-based adsorbents as well. In order to gain an understanding of the adsorption process kinetics, a detailed study was conducted in a controlled batch system. The effects of temperature and pH on the adsorption rates of arsenic (V) and arsenic (III) were investigated. Reaction rate constants were calculated at pH levels of 6.5 and 7.5. Rate data are best described by a pseudo first-order kinetic model at each temperature and pH condition studied. At lower pH values, arsenic (V) exhibits greater removal rates than arsenic (III). An increase in temperature increases the overall adsorption reaction rate constant values for both arsenic (V) and arsenic (III). An examination of thermodynamic parameters shows that the adsorption of arsenic (V) as well as arsenic (III) by GFH is an endothermic process and is spontaneous at the specific temperatures investigated.

  15. 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

  16. 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.

  17. 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...

  18. 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.

  19. IRON UPTAKE BY LEAF MESOPHYLL-CELLS - THE ROLE OF THE PLASMA MEMBRANE-BOUND FERRIC-CHELATE REDUCTASE

    NARCIS (Netherlands)

    BRUGGEMANN, W; MAASKANTEL, K; MOOG, PR

    1993-01-01

    The uptake of Fe-59 from FeCl3, ferric (Fe3+) citrate (FeCitr) and Fe3+-EDTA (FeEDTA) was studied in leaf mesophyll of Vigna unguiculata (L.) Walp. Uptake rates decreased in the order FeCl3>FeCitr much greater than FeEDTA, and uptake depended on an obligatory reduction step of Fe3+ to Fe2+, after wh

  20. 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...

  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. 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.

  4. 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

  5. Prevention of Acid Mine Drainage Through Complexation of Ferric Iron by Soluble Microbial Growth Products

    Science.gov (United States)

    Pandey, S.; Yacob, T. W.; Silverstein, J.; Rajaram, H.; Minchow, K.; Basta, J.

    2011-12-01

    Acid mine drainage (AMD) is a widespread environmental problem with deleterious impacts on water quality in streams and watersheds. AMD is generated largely by the oxidation of metal sulfides (i.e. pyrite) by ferric iron. This abiotic reaction is catalyzed by conversion of ferrous to ferric iron by iron and sulfur oxidizing microorganisms. Biostimulation is currently being investigated as an attempt to inhibit the oxidation of pyrite and growth of iron oxidizing bacteria through addition of organic carbon. This may stimulate growth of indigenous communities of acidophilic heterotrophic bacteria to compete for oxygen. The goal of this research is to investigate a secondary mechanism associated with carbon addition: complexation of free Fe(III) by soluble microbial growth products (SMPs) produced by microorganisms growing in waste rock. Exploratory research at the laboratory scale examined the effect of soluble microbial products (SMPs) on the kinetics of oxidation of pure pyrite during shaker flask experiments. The results confirmed a decrease in the rate of pyrite oxidation that was dependent upon the concentration of SMPs in solution. We are using these data to verify results from a pyrite oxidation model that accounts for SMPs. This reactor model involves differential-algebraic equations incorporating total component mass balances and mass action laws for equilibrium reactions. Species concentrations determined in each time step are applied to abiotic pyrite oxidation rate expressions from the literature to determine the evolution of total component concentrations. The model was embedded in a parameter estimation algorithm to determine the reactive surface area of pyrite in an abiotic control experiment, yielding an optimized value of 0.0037 m2. The optimized model exhibited similar behavior to the experiment for this case; the root mean squared of residuals for Fe(III) was calculated to be 7.58 x 10-4 M, which is several orders of magnitude less than the actual

  6. [Effectiveness of arsenite adsorption by ferric and alum water treatment residuals with different grain sizes].

    Science.gov (United States)

    Lin, Lu; Xu, Jia-Rui; Wu, Hao; Wang, Chang-Hui; Pei, Yuan-Sheng

    2013-07-01

    Effectiveness of arsenite adsorption by ferric and alum water treatment residuals (FARs) with different grain sizes was studied. The results indicated that the content of active Fe and Al, the specific surface area and pore volume in FARs with different grain sizes were in the range of 523.72-1 861.72 mmol x kg(-1), 28.15-265.59 m2 x g(-1) and 0.03-0.09 cm3 x g(-1), respectively. The contents of organic matter, fulvic acid, humic acid and humin were in the range of 46.97-91.58 mg x kg(-1), 0.02-32.27 mg x kg(-1), 22.27-34.09 mg x kg(-1) and 10.76-34.22 mg x kg(-1), respectively. Results of SEM and XRD analysis further demonstrated that FARs with different grain sizes were amorphousness. Batch experiments suggested that both the pseudo-first-order and pseudo-second-order equations could well describe the kinetics adsorption processes of arsenite by FARs. Moreover, the contents of arsenite absorbed by FARs increased with the increase of arsenite concentrations. The theoretical saturated adsorption capacities calculated from Langmuir isotherm model were in the range of 6.72-21.79 mg x g(-1). Interestingly, pH showed little effect on the arsenite adsorption capability of FARs. The capability of FARs had a close relationship with their physicochemical properties. Correlation analysis showed that the active Fe and Al contents and pore volume had major effects on the arsenite adsorption capability of FARs.

  7. Comparison of different phosphate species adsorption by ferric and alum water treatment residuals.

    Science.gov (United States)

    Gao, Sijia; Wang, Changhui; Pei, Yuansheng

    2013-05-01

    As safe byproducts of drinking water treatment processes, ferric and alum water treatment residuals (FARs) have the potential to be new phosphate (P) immobilization materials. In this study, batch experiments were conducted to investigate and compare the adsorption characteristics of three P species by FARs. The results showed that the kinetic processes of different P species' adsorption by FARs could be described by a pseudo second-order model. The ranking list of the initial adsorption rates with respect to different phosphates was pyrophosphate, phytate, orthophosphate, hexametaphosphate and glycerophosphate. Of the six models considered, the two-site Langmuir model most effectively described the adsorption characteristics of the various P species. Upon fitting the results, the maximum adsorption capacities were determined to be 40.24 mg/g for phytate, 18.04 mg/g for pyrophosphate, 17.14 mg/g for orthophosphate, 15.86 mg/g for hexametaphosphate and 10.81 mg/g for glycerophosphate. In addition, the adsorption processes of the different P species were spontaneous endothermic processes and were favored at lower pH values. The pH dependency was found to be especially true for orthophosphate, where the adsorption capacity decreased by 1.22 mg/g with an increase in pH from 5 to 9. Fractionation of the adsorbed P species from the FARs demonstrated that Al-P and Fe-P were the dominating forms, constituting approximately 80%-90% of the total P fractions, which indicated that the adsorbed P species had a low leaching risk and could stably exist in the FARs. Therefore, the FARs could be effective in controlling pollution in water caused by different P species.

  8. [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 < 0, which indicated that orthophosphate sorption on the FARs was a spontaneously endothermic chemical reaction. It can be therefore highly valued that the FARs may be applied to phosphate removal from wastewater and surface water.

  9. Comparison of different phosphate species adsorption by ferric and alum water treatment residuals

    Institute of Scientific and Technical Information of China (English)

    Sijia Gao; Changhui Wang; Yuansheng Pei

    2013-01-01

    As safe byproducts of drinking water treatment processes,ferric and alum water treatment residuals (FARs) have the potential to be new phosphate (P) immobilization materials.In this study,batch experiments were conducted to investigate and compare the adsorption characteristics of three P species by FARs.The results showed that the kinetic processes of different P species' adsorption by FARs could be described by a pseudo second-order model.The ranking list of the initial adsorption rates with respect to different phosphates was pyrophosphate,phytate,orthophosphate,hexametaphosphate and glycerophosphate.Of the six models considered,the two-site Langmuir model most effectively described the adsorption characteristics of the various P species.Upon fitting the results,the maximum adsorption capacities were determined to be 40.24 mg/g for phytate,18.04 mg/g for pyrophosphate,17.14 mg/g for orthophosphate,15.86 mg/g for hexametaphosphate and 10.81 mg/g for glycerophosphate.In addition,the adsorption processes of the different P species were spontaneous endothermic processes and were favored at lower pH values.The pH dependency was found to be especially true for orthophosphate,where the adsorption capacity decreased by 1.22 mg/g with an increase in pH from 5 to 9.Fractionation of the adsorbed P species from the FARs demonstrated that A1-P and Fe-P were the dominating forms,constituting approximately 80%-90% of the total P fractions,which indicated that the adsorbed P species had a low leaching risk and could stably exist in the FARs.Therefore,the FARs could be effective in controlling pollution in water caused by different P species.

  10. 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.

  11. A method for preparing ferric activated carbon composites adsorbents to remove arsenic from drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Qiaoli [State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092 (China); School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130 (China)], E-mail: qiaolizh@yahoo.com.cn; Lin, Y.C. [School of Mechanical and Electrical Engineering, Central South University, Changsha 410083 (China)], E-mail: linyongcheng@163.com; Chen, X. [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Gao Naiyun [State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092 (China)

    2007-09-30

    Iron oxide/activated carbon (FeO/AC) composite adsorbent material, which was used to modify the coal-based activated carbon (AC) 12 x 40, was prepared by the special ferric oxide microcrystal in this study. This composite can be used as the adsorbent to remove arsenic from drinking water, and Langmuir isotherm adsorption equation well describes the experimental adsorption isotherms. Then, the arsenic desorption can subsequently be separated from the medium by using a 1% aqueous NaOH solution. The apparent characters and physical chemistry performances of FeO/AC composite were investigated by X-ray diffraction (XRD), nitrogen adsorption, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Batch and column adsorption experiments were carried out to investigate and compare the arsenic removal capability of the prepared FeO/AC composite material and virgin activated carbon. It can be concluded that: (1) the main phase present in this composite are magnetite (Fe{sub 3}O{sub 4}), maghemite ({gamma}-Fe{sub 2}O{sub 3}), hematite ({alpha}-Fe{sub 2}O{sub 3}) and goethite ({alpha}-FeO(OH)); (2) the presence of iron oxides did not significantly affect the surface area or the pore structure of the activated carbon; (3) the comparisons between the adsorption isotherms of arsenic from aqueous solution onto the composite and virgin activated carbon showed that the FeO/AC composite behave an excellent capacity of adsorption arsenic than the virgin activated carbon; (4) column adsorption experiments with FeO/AC composite adsorbent showed that the arsenic could be removed to below 0.01 mg/L within 1250 mL empty bed volume when influent concentration was 0.5 mg/L.

  12. 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

  13. 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

  14. 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.

  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. Iron-reducing bacteria accumulate ferric oxyhydroxide nanoparticle aggregates that may support planktonic growth.

    Science.gov (United States)

    Luef, Birgit; Fakra, Sirine C; Csencsits, Roseann; Wrighton, Kelly C; Williams, Kenneth H; Wilkins, Michael J; Downing, Kenneth H; Long, Philip E; Comolli, Luis R; Banfield, Jillian F

    2013-02-01

    Iron-reducing bacteria (FeRB) play key roles in anaerobic metal and carbon cycling and carry out biogeochemical transformations that can be harnessed for environmental bioremediation. A subset of FeRB require direct contact with Fe(III)-bearing minerals for dissimilatory growth, yet these bacteria must move between mineral particles. Furthermore, they proliferate in planktonic consortia during biostimulation experiments. Thus, a key question is how such organisms can sustain growth under these conditions. Here we characterized planktonic microbial communities sampled from an aquifer in Rifle, Colorado, USA, close to the peak of iron reduction following in situ acetate amendment. Samples were cryo-plunged on site and subsequently examined using correlated two- and three-dimensional cryogenic transmission electron microscopy (cryo-TEM) and scanning transmission X-ray microscopy (STXM). The outer membranes of most cells were decorated with aggregates up to 150 nm in diameter composed of ∼3 nm wide amorphous, Fe-rich nanoparticles. Fluorescent in situ hybridization of lineage-specific probes applied to rRNA of cells subsequently imaged via cryo-TEM identified Geobacter spp., a well-studied group of FeRB. STXM results at the Fe L(2,3) absorption edges indicate that nanoparticle aggregates contain a variable mixture of Fe(II)-Fe(III), and are generally enriched in Fe(III). Geobacter bemidjiensis cultivated anaerobically in the laboratory on acetate and hydrous ferric oxyhydroxides also accumulated mixed-valence nanoparticle aggregates. In field-collected samples, FeRB with a wide variety of morphologies were associated with nano-aggregates, indicating that cell surface Fe(III) accumulation may be a general mechanism by which FeRB can grow while in planktonic suspension.

  17. Iron-reducing bacteria accumulate ferric oxyhydroxide nanoparticle aggregates that may support planktonic growth

    Energy Technology Data Exchange (ETDEWEB)

    Luef, Birgit; Fakra, Sirine C.; Csencsits, Roseann; Wrighton, Kelly C.; Williams, Kenneth H.; Wilkins, Michael J.; Downing, Kenneth H.; Long, Philip E.; Comolli, Luis R.; Banfield, Jillian F.

    2013-02-04

    Iron-reducing bacteria (FeRB) play key roles in anaerobic metal and carbon cycling and carry out biogeochemical transformations that can be harnessed for environmental bioremediation. A subset of FeRB require direct contact with Fe(III) bearing minerals for dissimilatory growth, yet these bacteria must move between mineral particles. Further, they proliferate in planktonic consortia during biostimulation experiments. Thus, a key question is how such organisms can sustain growth under these conditions. Here we characterized planktonic microbial communities sampled from an aquifer in Rifle, Colorado, USA close to the peak of iron reduction following in situ acetate amendment. Samples were cryo-plunged on site and subsequently examined using correlated 2- and 3- dimensional cryogenic transmission electron microscopy (cryo-TEM) and scanning transmission X-ray microscopy (STXM). Most cells had their outer membranes decorated with up to 150 nm diameter aggregates composed of a few nm wide amorphous, Fe-rich nanoparticles. Fluorescent in situ hybridization of lineage-specific probes applied to rRNA of cells subsequently imaged via cryo-TEM identified Geobacter spp., a well studied group of FeRB. STXM results at the Fe L2,3 absorption edges indicate that nanoparticle aggregates contain a variable mixture of Fe(II)-Fe(III), and are generally enriched in Fe(III). Geobacter bemidjiensis cultivated anaerobically in the laboratory on acetate and hydrous ferric oxyhydroxides also accumulated mixed valence nanoparticle aggregates. In field-collected samples, FeRB with a wide variety of morphologies were associated with nano-aggregates, indicating that cell-surface Fe(III) accumulation may be a general mechanism by which FeRB can grow while in planktonic suspension.

  18. 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.

  19. 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...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation...

  20. Selective ion exchange recovery of rare earth elements from uranium mining solutions

    Science.gov (United States)

    Rychkov, Vladimir N.; Kirillov, Evgeny V.; Kirillov, Sergey V.; Bunkov, Grigory M.; Mashkovtsev, Maxim A.; Botalov, Maxim S.; Semenishchev, Vladimir S.; Volkovich, Vladimir A.

    2016-09-01

    A comparative study of rare earth, ferric and aluminum ions ion exchange behavior on gel sulfonated p;olystyrene cation exchange resins depending on the degree of the matrix cross-linking and pH of the solution is presented. Selective ion exchange of REEs is possible at the pH range of 1.5-2.0 using strongly acidic cation exchange resins containing more than 8 % of DVB. The preliminary results of testing the efficiency of REEs recovery from the industrial uranium underground leaching solutions are also presented.

  1. 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.

  2. 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.

  3. 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 ...

  4. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  5. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  6. 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.

  7. 黄瓜叶片对草酸铁的还原作用%Reduction of Ferric Oxalate by Cucumber Leaves

    Institute of Scientific and Technical Information of China (English)

    彭新湘; 张景鹏; 李明启

    2001-01-01

    铁还原作用在植物叶片对铁素吸收及利用过程中起关键作用.本研究表明:相对于其它几种常用的铁螯合物如二乙基四乙酸铁(FeⅢEDTA)或柠檬酸铁,草酸铁更有利于黄瓜活体叶片及铁还原酶的作用,即表现出更高的铁还原活力.缺铁降低了黄瓜叶片中的铁还原活性.缺铁时叶片中的草酸含量不受影响,而富含在石灰性缺铁土壤中的碳酸氢根离子能使叶片中草酸含量显著提高.%Ferric reduction may play an important role in iron acquisition and utilization for the cells of plant leaves. This study revealed that ferric oxalate could serve as a better substrate for the ferric reduction by either leaf discs or the membrane-bound ferric reduc tase compared with the other commonly-used ferric chelates such as FeⅢ EDTA and ferric citrate. Iron deficiency was not able to increase the ferric reduction in cucumber leaves, which usually occurs in the roots. Iron deficiency itself had no effect on oxalate content in the leaves, but bicarbonate, abundant in calcareous soil, significantly increased the leaf oxalate content.

  8. Gas desulfurization with ferric chelates of EDTA and HEDTA: New model for the oxidative absorption of hydrogen sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Demmink, J.F.; Beenackers, A.A.C.M. [Univ. of Groningen (Netherlands). Dept. of Chemical Engineering

    1998-04-01

    The experimental data of Wubs and Beenackers on the oxidative absorption of H{sub 2}S into aqueous solutions of ferric chelates of ethylenediaminetetraacetic acid (EDTA) and hydroxyethylethylenediaminetriactic (HEDTA) were reinterpreted using a new penetration model for mass transfer parallel to chemical reaction. Different from the discussion by Wubs and Beenackers (1994), which was based on general, approximate models for the reactive absorption of gases into liquids, it now appears that the diffusivity of ferric chelates of EDTA and HEDTA are in good agreement with the values determined from the reactive absorption of molecular oxygen into aqueous solutions of ferrous EDTA and HEDTA. Also, it now appears that the data from Wubs and Beenackers (1994) are compatible with ferric chelate complex equilibrium constants, reported elsewhere. Reinterpretation of the absorption data from Wubs and Beenackers (1994) resulted in the following kinetic rate constants (T = 293 K, C{sub Fe(III)} = 78 mol/m{sup 3} and 2 {le} pH {le} 9): EDTA, monohydroxylated complex, 250 {le} k{sub 1.1} {le} 300 m{sup 3}/(mol s); HEDTA, monohydroxylated complex, 1.4 {le} k{sub 1.1} {le} 1.6 m{sup 3}/(mol s); HEDTA, dihydroxylated complex, 550 {le} k{sub 1.1} {le} 650 m{sup 3}/(mol s); for the reaction rate expressed by {minus}R{sub H{sub 2}S} = k{sub 1.1}C{sub h{sub 2}S}C{sub Fe(III)}.

  9. 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.

  10. Filamentous hydrous ferric oxide biosignatures in a pipeline carrying acid mine drainage at Iron Mountain Mine, California

    Science.gov (United States)

    Williams, Amy J.; Alpers, Charles N.; Sumner, Dawn Y.; Campbell, Kate M.

    2016-01-01

    A pipeline carrying acidic mine effluent at Iron Mountain, CA, developed Fe(III)-rich precipitate caused by oxidation of Fe(II)aq. The native microbial community in the pipe included filamentous microbes. The pipe scale consisted of microbial filaments, and schwertmannite (ferric oxyhydroxysulfate, FOHS) mineral spheres and filaments. FOHS filaments contained central lumina with diameters similar to those of microbial filaments. FOHS filament geometry, the geochemical environment, and the presence of filamentous microbes suggest that FOHS filaments are mineralized microbial filaments. This formation of textural biosignatures provides the basis for a conceptual model for the development and preservation of biosignatures in other environments.

  11. 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。

  12. 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.

  13. 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。

  14. 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.

  15. Influence of organic matter on the transport of Cryptosporidium parvum oocysts in a ferric oxyhydroxide-coated quartz sand saturated porous medium

    Science.gov (United States)

    Abudalo, R.A.; Ryan, J.N.; Harvey, R.W.; Metge, D.W.; Landkamer, L.

    2010-01-01

    To assess the effect of organic matter on the transport of Cryptosporidium parvum oocysts in a geochemically heterogeneous saturated porous medium, we measured the breakthrough and collision efficiencies of oocysts as a function of dissolved organic matter concentration in a flow-through column containing ferric oxyhydroxide-coated sand. We characterized the surface properties of the oocysts and ferric oxyhydroxide-coated sand using microelectrophoresis and streaming potential, respectively, and the amount of organic matter adsorbed on the ferric oxyhydroxide-coated sand as a function of the concentration of dissolved organic matter (a fulvic acid isolated from Florida Everglades water). The dissolved organic matter had no significant effect on the zeta potential of the oocysts. Low concentrations of dissolved organic matter were responsible for reversing the charge of the ferric oxyhydroxide-coated sand surface from positive to negative. The charge reversal and accumulation of negative charge on the ferric oxyhydroxide-coated sand led to increases in oocyst breakthrough and decreases in oocyst collision efficiency with increasing dissolved organic matter concentration. The increase in dissolved organic matter concentration from 0 to 20 mg L-1 resulted in a two-fold decrease in the collision efficiency. ?? 2009 Elsevier Ltd.

  16. 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.

  17. The bacterial lipocalins.

    Science.gov (United States)

    Bishop, R E

    2000-10-18

    The lipocalins were once regarded as a eukaryotic protein family, but new members have been recently discovered in bacteria. The first bacterial lipocalin (Blc) was identified in Escherichia coli as an outer membrane lipoprotein expressed under conditions of environmental stress. Blc is distinguished from most lipocalins by the absence of intramolecular disulfide bonds, but the presence of a membrane anchor is shared with two of its closest homologues, apolipoprotein D and lazarillo. Several common features of the membrane-anchored lipocalins suggest that each may play an important role in membrane biogenesis and repair. Additionally, Blc proteins are implicated in the dissemination of antibiotic resistance genes and in the activation of immunity. Recent genome sequencing efforts reveal the existence of at least 20 bacterial lipocalins. The lipocalins appear to have originated in Gram-negative bacteria and were probably transferred horizontally to eukaryotes from the endosymbiotic alpha-proteobacterial ancestor of the mitochondrion. The genome sequences also reveal that some bacterial lipocalins exhibit disulfide bonds and alternative modes of subcellular localization, which include targeting to the periplasmic space, the cytoplasmic membrane, and the cytosol. The relationships between bacterial lipocalin structure and function further illuminate the common biochemistry of bacterial and eukaryotic cells.

  18. 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

  19. Electrodeposition of Nanometer-Sized Ferric Oxide Materials in Colloidal Templates for Conversion of Light to Chemical Energy

    Directory of Open Access Journals (Sweden)

    James M. Gardner

    2011-01-01

    Full Text Available Colloidal crystal templates were prepared by gravitational sedimentation of 0.5 micron polystyrene particles onto fluorine-doped tin oxide (FTO electrodes. Scanning electron microscopy (SEM shows that the particles were close packed and examination of successive layers indicated a predominantly face-centered-cubic (fcc crystal structure where the direction normal to the substrate surface corresponds to the (111 direction. Oxidation of aqueous ferrous solutions resulted in the electrodeposition of ferric oxide into the templates. Removal of the colloidal templates yielded ordered macroporous electrodes (OMEs that were the inverse structure of the colloidal templates. Current integration during electrodeposition and cross-sectional SEM images revealed that the OMEs were about 2 μm thick. Comparative X-ray diffraction and infrared studies of the OMEs did not match a known phase of ferric oxide but suggested a mixture of goethite and hematite. The spectroscopic properties of the OMEs were insensitive to heat treatments at 300∘C. The OMEs were utilized for photoassisted electrochemical oxidation. A sustained photocurrent was observed from visible light in aqueous photoelectrochemical cells. Analysis of photocurrent action spectra revealed an indirect band gap of 1.85 eV. Addition of formate to the aqueous electrolytes resulted in an approximate doubling of the photocurrent.

  20. 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

  1. Large-scale synthesis of isolated Mn2O3 nanotube/fiber with ferric nitrate as catalyst

    Institute of Scientific and Technical Information of China (English)

    ZHANG Aifei; LIU Jiping; L(U) Guangshu

    2007-01-01

    Isolated Mn203 nanotubes and nanofibers were prepared very easily at a large scale with the liquid-phase catalysis method.The Mn2O3 nanotubes had dimensions of 30-50 nm (exterior diameter) and 0.2-1.0 μm (length),approximately.The Mn2O3 nanofibers had dimensions of 10-30 nm (diameter) and 0.4-2.0 μm (length),approximately.Nano-Mn2O3 with different microstructures including nanotubes,nanofibers and nanoparticles could be selectively synthesized by controlling the contents and proportions of potassium permanganate and ferric nitrate.Ferric nitrate was an ideal catalyst for the preparation of Mn2O3 nanotube/fiber.When cobalt nitrate or nickel nitrate was used as catalyst,only amorphous nano-Mn2O3 was synthesized.Xray diffraction (XRD) result shows that the Mn2O3 nanotube has a crystalline structure different from o-Mn2O3,t-Mn2O3,h-Mn2O3 and 7-Mn2O3.

  2. 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

  3. 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.

  4. Bacterial glycosyltransferase toxins.

    Science.gov (United States)

    Jank, Thomas; Belyi, Yury; Aktories, Klaus

    2015-12-01

    Mono-glycosylation of host proteins is a common mechanism by which bacterial protein toxins manipulate cellular functions of eukaryotic target host cells. Prototypic for this group of glycosyltransferase toxins are Clostridium difficile toxins A and B, which modify guanine nucleotide-binding proteins of the Rho family. However, toxin-induced glycosylation is not restricted to the Clostridia. Various types of bacterial pathogens including Escherichia coli, Yersinia, Photorhabdus and Legionella species produce glycosyltransferase toxins. Recent studies discovered novel unexpected variations in host protein targets and amino acid acceptors of toxin-catalysed glycosylation. These findings open new perspectives in toxin as well as in carbohydrate research.

  5. HYDROGEN GENERATION FROM SOLID SODIUM BOROHYDRIDE WITH FERRIC CATALYTS%基于铁盐催化的固态硼氢化钠制氢研究

    Institute of Scientific and Technical Information of China (English)

    方朝君; 闫常峰; 郭常青

    2012-01-01

    Sodium borohydride' s properties such as environmental friendly, reliability, efficiency etc. , make it a good source of hydrogen. Its hydrolysis reaction with the assistance of catalysts to liberate hydrogen gas is easily controllable. Tests were conducted to evaluate effects of ferric sulfate concentration, initial reaction temperature and solution feeding flow rate on hydrogen generation using non-noble ferric sulfate as catalyst. Ferric sulfate' s catalytic activity is evidently higher than ferric nitrate and ferric chloride. Maximum H2 flow was obtained under the condition of ferric sulfate in 1. 5mol/L. The conversion increases slowly with the increasing of reaction temperature in the range of 20-48℃. And the conversion could finally reach over 90% .%以非贵金属铁盐为催化剂,考察不同浓度的Fe2(SO4)3溶液、初始反应温度和不同进液速率下的固态NaBH4水解产氢性能.实验表明:相同浓度下,Fe2(SO4)3的催化产氢性能高于Fe(NO3)2和FeCl3.在Fe2(SO4)3溶液浓度为1.5mol/L时产氢速率出现最大值,提高Fe2(SO4)3浓度,可提高平均产氢速率;在20 ~48℃范围内,随反应温度的升高,产氢转化率略有上升,最终均能达到90%以上.

  6. 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

  7. Identification and characterization of a novel outer membrane protein receptor FetA for ferric enterobactin transport in Vibrio anguillarum 775 (pJM1)

    OpenAIRE

    Naka, Hiroaki; Crosa, Jorge H.

    2011-01-01

    In this work we demonstrate the existence in Vibrio anguillarum 775 (pJM1) of two chromosomal genes encoding outer membrane proteins that operate in the transport of ferric enterobactin. One of them is a novel receptor that we named FetA and the other is the already characterized FvtA that functions in the uptake of iron complexes of both enterobactin and vanchrobactin. Ferric enterobactin transport proficiency was resumed in double mutants for these two genes when they were complemented with...

  8. Superconducting racetrack booster for the ion complex of MEIC

    Energy Technology Data Exchange (ETDEWEB)

    Filatov, Yu [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); Moscow Inst. of Physics and Technology (MIPT), Moscow (Russian Federation); Kondratenko, A. M. [Science and Technique Laboratory ' Zaryad' , 630090, Novosibirsk, Russia; Kondratenko, M. A. [Science and Technique Laboratory ' Zaryad' , 630090, Novosibirsk, Russia; Kovalenko, A. [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    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.

  9. Seizures Complicating Bacterial Meningitis

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-09-01

    Full Text Available The clinical data of 116 patients, 1 month to <5 years of age, admitted for bacterial meningitis, and grouped according to those with and without seizures during hospitalization, were compared in a study at Buddhist Dalin Tzu Chi General Hospital, Chang Gung Memorial Hospital and other centers in Taiwan.

  10. 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.

  11. 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 ...

  12. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    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. 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...

  14. Modeling intraocular bacterial infections.

    Science.gov (United States)

    Astley, Roger A; Coburn, Phillip S; Parkunan, Salai Madhumathi; Callegan, Michelle C

    2016-09-01

    Bacterial endophthalmitis is an infection and inflammation of the posterior segment of the eye which can result in significant loss of visual acuity. Even with prompt antibiotic, anti-inflammatory and surgical intervention, vision and even the eye itself may be lost. For the past century, experimental animal models have been used to examine various aspects of the pathogenesis and pathophysiology of bacterial endophthalmitis, to further the development of anti-inflammatory treatment strategies, and to evaluate the pharmacokinetics and efficacies of antibiotics. Experimental models allow independent control of many parameters of infection and facilitate systematic examination of infection outcomes. While no single animal model perfectly reproduces the human pathology of bacterial endophthalmitis, investigators have successfully used these models to understand the infectious process and the host response, and have provided new information regarding therapeutic options for the treatment of bacterial endophthalmitis. This review highlights experimental animal models of endophthalmitis and correlates this information with the clinical setting. The goal is to identify knowledge gaps that may be addressed in future experimental and clinical studies focused on improvements in the therapeutic preservation of vision during and after this disease. PMID:27154427

  15. 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.

  16. 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.

  17. 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...

  18. 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).

  19. 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)

  20. Preparation of polymer-supported hydrated ferric oxide based on Donnan membrane effect and its application for arsenic removal

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the present study a novel technique was proposed to prepare a polymer-supported hydrated ferric oxide (D201-HFO) based on Donnan membrane effect by using a strongly basic anion exchanger D201 as the host material and FeCl3-HCl-NaCl solution as the reaction environment. D201-HFO was found to exhibit higher capacity for arsenic removal than a commercial sorbent Purolite ArsenX. Furthermore, it presents favorable adsorption selectivity for arsenic removal from aqueous solution, as well as satis- factory kinetics. Fixed-bed column experiments showed that arsenic sorption on D201-HFO could re- sult in concentration of this toxic metalloid element below 10 μg/L, which was the new maximum con- centration limit set recently by the European Commission and imposed by the US EPA and China. Also, the spent D201-HFO is amenable to efficient regeneration by NaOH-NaCl solution.

  1. 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.

  2. Preparation of polymer-supported hydrated ferric oxide based on Donnan membrane effect and its application for arsenic removal

    Institute of Scientific and Technical Information of China (English)

    ZHANG QingJian; PAN BingCai; CHEN XinQing; ZHANG WeiMing; PAN BingJun; ZHANG QuanXing; L. LV; X. S. ZHAO

    2008-01-01

    In the present study a novel technique was proposed to prepare a polymer-supported hydrated ferric oxide (D201-HFO) based on Donnan membrane effect by using a strongly basic anion exchanger D201 as the host material and FeCl3-HCl-NaCl solution as the reaction environment. D201-HFO was found to exhibit higher capacity for arsenic removal than a commercial sorbent Purolite ArsenX. Furthermore, it presents favorable adsorption selectivity for arsenic removal from aqueous solution, as well as satis-factory kinetics. Fixed-bed column experiments showed that arsenic sorption on D201-HFO could re-sult in concentration of this toxic metalloid element below 10 μg/L, which was the new maximum con-centration limit set recently by the European Commission and imposed by the US EPA and China. Also, the spent D201-HFO is amenable to efficient regeneration by NaOH-NaCI solution.

  3. 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)

  4. 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.

  5. 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)

  6. Ferric hydrogensulfate catalyzed synthesis of aryl 14H-dibenzo[a,j] xanthene derivatives under thermal and solvent-free conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shaterian, Hamid Reza; Ghashang, Majid [University of Sistan and Baluchestan, Zahedan (Iran, Islamic Republic of). Faculty of Sciences. Dept. of Chemistry]. E-mail: hrshaterian@hamoon.usb.ac.ir

    2008-07-01

    Ferric hydrogensulfate as catalyst has been used for the one-pot preparation of aryl 14Hdibenzo[a,j]xanthene derivatives by cyclocondensation of {beta}-naphthol and substituted benzaldehydes under solvent-free and thermal conditions. This method has the advantages of high yields, a cleaner reaction, simple methodology, short reaction times, easy workup and greener conditions. (author)

  7. Dual fortification of salt with iodine and iron: a randomized, double-blind, controlled trial of micronized ferric pyrophosphate and encapsulated ferrous fumarate in southern India

    NARCIS (Netherlands)

    Andersson, M.; Thankachan, P.; Muthayya, S.; Goud, R.B.; Kurpad, A.V.; Hurrell, R.F.

    2008-01-01

    Background:Dual fortification of salt with iodine and iron could be a sustainable approach to combating iodine and iron deficiencies. Objective:We compared the efficacy of dual-fortified salt (DFS) made by using 2 proposed contrasting formulas-one fortifying with iron as micronized ground ferric pyr

  8. 共沉淀氢氧化铁急性毒性试验研究%Acute toxicity test study of co-precipitation ferric hydroxide

    Institute of Scientific and Technical Information of China (English)

    洪南华; 李诚

    2012-01-01

    For studying the acute toxicity of co-precipitation ferric hydroxide, kunming mice were divided into 4 groups and given co-precipitation ferric hydroxide at different dose. The result showed that the LD50 of co-precipitation ferric hydroxide was higher than 21500mg/kg m, and thus classified as innocuity. So co-precipitation ferric hydroxide has no markedly acute recation as an iron fortificant.%为探讨共沉淀氢氧化铁的毒性作用,以昆明小鼠为试验对象,对所研制的共沉淀氢氧化铁进行急性毒理学试验,结果表明以共沉淀氢氧化铁灌胃,对小鼠的LD50> 21500mg/kg,属于无毒级.因此共沉淀氢氧化铁作为一种铁强化剂无明显急性毒理反应.

  9. 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

  10. Ferric Perchlorate Catalyzed One-pot Synthesis of 1,2,3,4-Tetrahydro-2-pyrimidinones and -thiones:an Expedient Protocol for the Biginelli Reaction

    Institute of Scientific and Technical Information of China (English)

    HERAVI,Majid Momahed; BEHBAHANI,Farahnaz Kargar OSKOOIE; Hossien Abdi

    2008-01-01

    An efficient synthesis of 1,2,3,4-tetrahydro-2-pyrimidinones and -thiones using ferric perchlorate as the catalyst from an aldehyde, ethyl acetoacetate, and urea or thiourea in acetonitrile was described. Compared to the classical Biginelli reaction conditions, this new method consistently has the advantage of full catalysis, good yields and short reaction time.

  11. 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

  12. Bacterial chemoreceptors and chemoeffectors.

    Science.gov (United States)

    Bi, Shuangyu; Lai, Luhua

    2015-02-01

    Bacteria use chemotaxis signaling pathways to sense environmental changes. Escherichia coli chemotaxis system represents an ideal model that illustrates fundamental principles of biological signaling processes. Chemoreceptors are crucial signaling proteins that mediate taxis toward a wide range of chemoeffectors. Recently, in deep study of the biochemical and structural features of chemoreceptors, the organization of higher-order clusters in native cells, and the signal transduction mechanisms related to the on-off signal output provides us with general insights to understand how chemotaxis performs high sensitivity, precise adaptation, signal amplification, and wide dynamic range. Along with the increasing knowledge, bacterial chemoreceptors can be engineered to sense novel chemoeffectors, which has extensive applications in therapeutics and industry. Here we mainly review recent advances in the E. coli chemotaxis system involving structure and organization of chemoreceptors, discovery, design, and characterization of chemoeffectors, and signal recognition and transduction mechanisms. Possible strategies for changing the specificity of bacterial chemoreceptors to sense novel chemoeffectors are also discussed.

  13. Bacterial Colony Optimization

    Directory of Open Access Journals (Sweden)

    Ben Niu

    2012-01-01

    Full Text Available This paper investigates the behaviors at different developmental stages in Escherichia coli (E. coli lifecycle and developing a new biologically inspired optimization algorithm named bacterial colony optimization (BCO. BCO is based on a lifecycle model that simulates some typical behaviors of E. coli bacteria during their whole lifecycle, including chemotaxis, communication, elimination, reproduction, and migration. A newly created chemotaxis strategy combined with communication mechanism is developed to simplify the bacterial optimization, which is spread over the whole optimization process. However, the other behaviors such as elimination, reproduction, and migration are implemented only when the given conditions are satisfied. Two types of interactive communication schemas: individuals exchange schema and group exchange schema are designed to improve the optimization efficiency. In the simulation studies, a set of 12 benchmark functions belonging to three classes (unimodal, multimodal, and rotated problems are performed, and the performances of the proposed algorithms are compared with five recent evolutionary algorithms to demonstrate the superiority of BCO.

  14. [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

  15. 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

  16. 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 ...

  17. Bacterial Colony Optimization

    OpenAIRE

    Ben Niu; Hong Wang

    2012-01-01

    This paper investigates the behaviors at different developmental stages in Escherichia coli (E. coli) lifecycle and developing a new biologically inspired optimization algorithm named bacterial colony optimization (BCO). BCO is based on a lifecycle model that simulates some typical behaviors of E. coli bacteria during their whole lifecycle, including chemotaxis, communication, elimination, reproduction, and migration. A newly created chemotaxis strategy combined with communication mechanism i...

  18. 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

  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. 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

  1. 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).

  2. 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)

  3. Effects of Reductive Biomineralization of Ferric Hydroxides on Sustained Microbial Metabolism and Contaminant Sequestration

    Science.gov (United States)

    Hansel, C. M.; Benner, S. G.; Nico, P. S.; Fendorf, S.

    2002-12-01

    Iron (hydr)oxides not only serve as potent sorbents and repositories for contaminants but also provide a terminal electron acceptor for microbial respiration. The microbial reduction of Fe (hydr)oxides and subsequent secondary solid-phase transformations will, therefore, have a profound influence on the biogeochemical cycling of Fe and associated metals. Here we elucidate the pathways and mechanisms of secondary mineralization during dissimilatory iron reduction of 2-line ferrihydrite under advective flow conditions. Solids were characterized using a host of spectroscopic and microscopic techniques to quantitatively determine the mineral components and microbial-mineral interactions. Secondary mineralization of ferrihydrite occurs via a coupled, biotic-abiotic pathway resulting in the production of primarily magnetite and goethite. Operating mineralization pathways are dictated by competing abiotic reactions of bacterially-generated ferrous iron with the ferrihydrite surface. The distribution of goethite and magnetite within the column is dictated, in large part, by flow-induced ferrous Fe profiles. While goethite precipitation ensues over a large Fe(II) concentration range, magnetite accumulation is only observed at concentrations exceeding 0.3 mM over a 9 d reaction period thus leading to a progression of magnetite levels downgradient within the column. While goethite's precipitation rate exceeds that of magnetite allowing for its initial precipitation, continued growth is inhibited by magnetite nucleation, most likely a result of lower Fe(III) activity. The operating secondary mineralization pathways following reductive dissolution of ferrihydrite at a given pH will therefore be governed by Fe(II) concentration, which drives mineral precipitation kinetics and selection of competing mineral pathways. The ultimate Fe mineral phase assemblage and distribution will have profound consequences on the reduction and sequestration of contaminants. For instance

  4. 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

  5. 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.

  6. Antimicrobials for bacterial bioterrorism agents.

    Science.gov (United States)

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future.

  7. The effect of pH and storage on copper speciation and bacterial growth in complex growth media

    DEFF Research Database (Denmark)

    Hasman, Henrik; Bjerrum, Morten J.; Christiansen, Lasse Engbo;

    2009-01-01

    In this paper we examine how the bacterial growth is influenced by the availability of copper ions in complex Mueller Hinton growth media. The data shows that the free copper concentration is seven to eight orders of magnitude lower the total copper concentration and that there seems to be a bett...... is to be recommended, when working with bacterial copper testing....

  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.

  9. 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

  10. 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...

  11. 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.

  12. 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

  13. Effect of low molecular weight organic acids on phosphorus adsorption by ferric-alum water treatment residuals.

    Science.gov (United States)

    Wang, Changhui; Wang, Ziyuan; Lin, Lu; Tian, Binghui; Pei, Yuansheng

    2012-02-15

    Effects of low molecular weight organic acids (LMWOAs; citric acid, oxalic acid and tartaric acid) on phosphorus (P) adsorption by ferric-alum water treatment residuals (FARs) were studied. Both batch and column experiments indicated that the effects of LMWOAs on P adsorption were closely related to adsorption time. Initially, all acids presented inhibitory function on P adsorption. The inhibition became weaker with time, eventually promoting P adsorption for citric acid and tartaric acid. In the column experiment with a 61-day duration, high P adsorption rates (>55%) were observed for the test groups containing citric acid and tartaric acid. Interestingly, higher pH likely enhanced P adsorption with the effects of LMWOAs and a distinct relationship between LMWOAs' effects on P adsorption and their concentrations was not observed. Moreover, fractionation of the adsorbed P from the FARs demonstrated that oxalic acid reduced P adsorption capacity, while citric acid and tartaric acid increased. Based on the forms of Fe and Al existing in the FARs and Fourier transform infrared spectroscopy analyses, LMWOAs can promote P adsorption through activating crystalline Fe/Al and preventing crystallization of amorphous Fe/Al to increase P adsorption sites, and can also inhibit P adsorption by competition with adsorption sites.

  14. Mercury (II) reduction and co-precipitation of metallic mercury on hydrous ferric oxide in contaminated groundwater.

    Science.gov (United States)

    Richard, Jan-Helge; Bischoff, Cornelia; Ahrens, Christian G M; Biester, Harald

    2016-01-01

    Mercury (Hg) speciation and sorption analyses in contaminated aquifers are useful for understanding transformation, retention, and mobility of Hg in groundwater. In most aquifers hydrous ferric oxides (HFOs) are among the most important sorbents for trace metals; however, their role in sorption or mobilization of Hg in aquifers has been rarely analyzed. In this study, we investigated Hg chemistry and Hg sorption to HFO under changing redox conditions in a highly HgCl2-contaminated aquifer (up to 870μgL(-1) Hg). Results from aqueous and solid phase Hg measurements were compared to modeled (PHREEQC) data. Speciation analyses of dissolved mercury indicated that Hg(II) forms were reduced to Hg(0) under anoxic conditions, and adsorbed to or co-precipitated with HFO. Solid phase Hg thermo-desorption measurements revealed that between 55 and 93% of Hg bound to HFO was elemental Hg (Hg(0)). Hg concentrations in precipitates reached more than 4 weight %, up to 7000 times higher than predicted by geochemical models that do not consider unspecific sorption to and co-precipitation of elemental Hg with HFO. The observed process of Hg(II) reduction and Hg(0) formation, and its retention and co-precipitation by HFO is thought to be crucial in HgCl2-contaminated aquifers with variable redox-conditions regarding the related decrease in Hg solubility (factor of ~10(6)), and retention of Hg in the aquifer.

  15. Iron Deficiency-induced Increase of Root Branching Contributes to the Enhanced Root Ferric Chelate Reductase Activity

    Institute of Scientific and Technical Information of China (English)

    Chong-Wei Jin; Wei-Wei Chen; Zhi-Bin Meng; Shao-Jian Zheng

    2008-01-01

    In various plant species, Fe deficiency increases lateral root branching. However, whether this morphological alteration contributes to the Fe deficiency-induced physiological responses still remains to be demonstrated. In the present research, we demonstrated that the lateral root development of red clover (Trifolium pretense L.) was significantly enhanced by Fe deficient treatment, and the total lateral root number correlated well with the Fe deficiency-induced ferric chelate reductase (FCR) activity. By analyzing the results from Dasgan et al. (2002), we also found that although the two tomato genotypes line227/1 (P1) and Roza (P2) and their reciprocal F1 hybrid lines ("P1 × P2" and "P2 × P1 ") were cultured under two different lower Fe conditions (10-6 and 10-7 M FeEDDHA), their FCR activities are significantly correlated with the lateral root number. More interestingly, the -Fe chlorosis tolerant ability of these four tomato lines displays similar trends with the lateral root density. Taking these results together, it was proposed that the Fe deficiency-induced increases of the lateral root should play an important role in resistance to Fe deficiency, which may act as harnesses of a useful trait for the selection and breeding of more Fe-efficiant crops among the genotypes that have evolved a Fe deficiency-induced Fe uptake system.

  16. Genotoxicity of ferric oxide nanoparticles in Raphanus sativus: Deciphering the role of signaling factors, oxidative stress and cell death.

    Science.gov (United States)

    Saquib, Quaiser; Faisal, Mohammad; Alatar, Abdulrahman A; Al-Khedhairy, Abdulaziz A; Ahmed, Mukhtar; Ansari, Sabiha M; Alwathnani, Hend A; Okla, Mohammad K; Dwivedi, Sourabh; Musarrat, Javed; Praveen, Shelly; Khan, Shams T; Wahab, Rizwan; Siddiqui, Maqsood A; Ahmad, Javed

    2016-09-01

    We have studied the genotoxic and apoptotic potential of ferric oxide nanoparticles (Fe2O3-NPs) in Raphanus sativus (radish). Fe2O3-NPs retarded the root length and seed germination in radish. Ultrathin sections of treated roots showed subcellular localization of Fe2O3-NPs, along with the appearance of damaged mitochondria and excessive vacuolization. Flow cytometric analysis of Fe2O3-NPs (1.0mg/mL) treated groups exhibited 219.5%, 161%, 120.4% and 161.4% increase in intracellular reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), nitric oxide (NO) and Ca(2+) influx in radish protoplasts. A concentration dependent increase in the antioxidative enzymes glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and lipid peroxidation (LPO) has been recorded. Comet assay showed a concentration dependent increase in deoxyribonucleic acid (DNA) strand breaks in Fe2O3-NPs treated groups. Cell cycle analysis revealed 88.4% of cells in sub-G1 apoptotic phase, suggesting cell death in Fe2O3-NPs (2.0mg/mL) treated group. Taking together, the genotoxicity induced by Fe2O3-NPs highlights the importance of environmental risk associated with improper disposal of nanoparticles (NPs) and radish can serve as a good indicator for measuring the phytotoxicity of NPs grown in NP-polluted environment. PMID:27593272

  17. 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.

  18. 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

  19. 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.

  20. Shock Experiments on Basalt - Ferric Sulfate Mixes at 21 GPa & 49 GPa and their Relevance to Martian Meteorite Impact Glasses

    Science.gov (United States)

    Rao, M. N.; Ross, D. K.; See, T. H.; Nyquist, L. E.; Sutton, S.; Asimow, P.

    2013-01-01

    Large abundance of Martian atmospheric gases and neutron-induced isotopic excesses as well as Rb-Sr isotopic variations determined in some impact glasses in basaltic shergottites (e.g., Shergotty #DBS, Zagami #H1 and EET79001 #27, #8 and #104) provide definitive evidence for the occurrence of a Martian regolith component in their constituent mineral assemblages. Some of these glass-es, known as gas-rich impact-melts (GRIM), contain numerous micron-sized iron sulfide blebs along with minor amounts of iron sulfate particulates. As these GRIM glasses contain a Martian regolith component and as iron sulfates (but not sulfides) are found to occur abundantly on the Mars surface, we suggested that the sulfide blebs in GRIMs were likely generated by shock-reduction of the parental iron sulfate bearing regolith material that had been incorporated into the cavities/crevices of basaltic host rock prior to the impact event on Mars. To test whether the sulfates could be reduced to sulfides by impact shock, we carried out laboratory shock experiments on a basalt plus ferric sulfate mixture at 49 GPa at the Caltech Shock Wave Laboratory and at 21 GPa at Johnson Space Center (JSC) Experimental Impact Laboratory. The experimental details and the preliminary results for the Caltech 49 GPa experiment were presented at LPSC last year. Here, we report the results for the 21 GPa experiment at JSC and compare these results to obtain further insight into the mechanism of the bleb formation in the GRIM glasses.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Synthesis of a ferric hydroxide-coated cellulose nanofiber hybrid for effective removal of phosphate from wastewater.

    Science.gov (United States)

    Cui, Guirong; Liu, Min; Chen, Ying; Zhang, Wei; Zhao, Jiangqi

    2016-12-10

    Ferric hydroxide-coated cellulose nanofibers (Fe(OH)3@CNFs) were synthesized for the removal of phosphate from wastewater. The maximum sorption capacity of Fe(OH)3@CNFs for phosphate was estimated to be 142.86mg/g, demonstrating a superior adsorption capacity compared with many adsorbents reported in the literature. Batch experiments were performed to investigate various adsorption conditions on the adsorption performance. It was discovered that an increased solution ionic strength would remarkably enhance the adsorption. Additionally, Fe(OH)3@CNFs achieved a favorable adsorption performance over a wide range of pH conditions, which could result in operation cost savings. The adsorption of phosphate can be described by both the Langmuir isotherm and pseudo-second-order models. The phosphate adsorbed by Fe(OH)3@CNFs was characterized using XPS, SEM, SBET and EDS. The data obtained revealed that the electrostatic attraction and ligand exchange constituted the major forces in phosphate adsorption. This work suggested that Fe(OH)3@CNFs are a promising adsorbent for phosphate removal. PMID:27577894

  7. 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.

  8. Two-component PhoB-PhoR regulatory system and ferric uptake regulator sense phosphate and iron to control virulence genes in type III and VI secretion systems of Edwardsiella tarda.

    Science.gov (United States)

    Chakraborty, Smarajit; Sivaraman, J; Leung, Ka Yin; Mok, Yu-Keung

    2011-11-11

    Inorganic phosphate (P(i)) and iron are essential nutrients that are depleted by vertebrates as a protective mechanism against bacterial infection. This depletion, however, is sensed by some pathogens as a signal to turn on the expression of virulence genes. Here, we show that the PhoB-PhoR two-component system senses changes in P(i) concentration, whereas the ferric uptake regulator (Fur) senses changes in iron concentration in Edwardsiella tarda PPD130/91 to regulate the expression of type III and VI secretion systems (T3SS and T6SS) through an E. tarda secretion regulator, EsrC. In sensing low P(i) concentration, PhoB-PhoR autoregulates and activates the phosphate-specific transport operon, pstSCAB-phoU, by binding directly to the Pho box in the promoters of phoB and pstS. PhoB also binds with EsrC simultaneously on the promoter of an E. tarda virulence protein, evpA, to regulate directly the transcription of genes from T6SS. In addition, PhoB requires and interacts with PhoU to activate esrC and suppress fur indirectly through unidentified regulators. Fur, on the other hand, senses high iron concentration and binds directly to the Fur box in the promoter of evpP to inhibit EsrC binding to the same region. In addition, Fur suppresses transcription of phoB, pstSCAB-phoU, and esrC indirectly via unidentified regulators, suggesting negative cross-talk with the Pho regulon. Physical interactions exist between Fur and PhoU and between Fur and EsrC. Our findings suggest that T3SS and T6SS may carry out distinct roles in the pathogenicity of E. tarda by responding to different environmental factors.

  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 communities...

  11. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    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...... signalling to short-circuit host cell processes. Common to both intra- and extracellular proteases is the tight control of their proteolytic activities. In general, substrate recognition by the intracellular proteases is highly selective which is, in part, attributed to the chaperone activity associated...

  12. 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.

  13. 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

  14. 氧化铁常温脱硫研究综述%A review on studies of ambient temperature ferric oxide desulfurizers

    Institute of Scientific and Technical Information of China (English)

    贺恩云; 樊惠玲; 王小玲; 王龙江; 李叶; 黄冠

    2014-01-01

    氧化铁脱硫剂具有廉价易得,硫容高,再生简单等优点,因而受到广大科研工作者广泛关注。综述了氧化铁常温脱硫及再生原理,脱硫剂的制备,以及脱硫剂表面 pH 值、水含量等工艺参数对氧化铁脱硫性能的影响。并提出γ-Fe2O3是常温脱硫研究的新方向。%Ferric oxide desulfurizers have many advantages, such as cheapness, high sulfur capacity and easy regeneration, so researchers show great interest in the study on them. The principles of ferric oxide ambient temperature desulfurization and regeneration, the preparation of desulfurizers, and the effects of sorbent surface pH value, water content and other parameters on desulfurization performances of ferric oxides were reviewed. And it was proposed that γ-Fe2O3 should be a new direction for the research of ambient temperature desulfurization.

  15. 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 ...

  16. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten;

    2010-01-01

    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 tyrosine......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...... and highlighted their importance in bacterial physiology. Having no orthologues in Eukarya, BY-kinases are receiving a growing attention from the biomedical field, since they represent a particularly promising target for anti-bacterial drug design....

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. TREATMENT OF ANEMIA AND IMPROVEMENT OF QUALITY OF LIFE AMONG PATIENTS WITH CROHN'S DISEASE: experience using ferric carboxymaltose

    Directory of Open Access Journals (Sweden)

    Carlos Walter SOBRADO

    2015-12-01

    Full Text Available Objectives - Anemia is the most common hematological alteration in patients with Crohn's disease, and is frequently related to intestinal inflammatory activity. Its cause is multifactorial and mostly associated with absolute iron deficiency (iron deficiency anemia and/or functional iron deficiency (inflammation anemia or anemia of chronic disease. It may also be identified through other causes, such as folic acid or vitamin B12 deficiency and secondary to adverse effects from medications (salicylic derivatives and immunosuppressive drugs. In the present study, patients with active Crohn's disease and anemia were evaluated and treated with intravenous ferric carboxymaltose. We discuss the therapeutic schemes (doses, safety, results and improvement of quality of life. Methods - In the present prospective study, 10 consecutive patients with Crohn's disease, with moderate to severe activity, with anemia (Hb: 6.7 to 10 g/dL, who were attended between March 2014 and March 2015, were evaluated. Six (60% were men and four were women, all with moderate or severe anemia (hemoglobin <10 g/dL. They were treated with a maximum of three intravenous infusions of 1000 mg of ferric carboxymaltose, of at least 15 minutes in duration. It was also sought to correlate the inflammatory Crohn's disease activity degree (measured using the Crohn's Disease Activity Index, CDAI and C-reactive protein level with the severity of anemia. The primary outcome was an increase in Hb of ≥2 g/dL and the secondary outcome was the normalization of anemia (Hb ≥12 g/dL for women and ≥13 g/dL for men and the improvement in quality of life seen 12 weeks after the last application of carboxymaltose. Results - Among the 10 patients studied, parenteral iron supplementation was administered in three cases during hospitalization and the others received this on an outpatient basis. The total iron dose ranged from 1,000 to 2,000 mg, with an average of 1,650 mg. Crohn's disease activity

  2. Short-term effect of the soil amendments activated carbon, biochar, and ferric oxyhydroxide on bacteria and invertebrates.

    Science.gov (United States)

    Hale, Sarah E; Jensen, John; Jakob, Lena; Oleszczuk, Patryk; Hartnik, Thomas; Henriksen, Thomas; Okkenhaug, Gudny; Martinsen, Vegard; Cornelissen, Gerard

    2013-08-01

    The aim of the present study was to evaluate the secondary ecotoxicological effects of soil amendment materials that can be added to contaminated soils in order to sequester harmful pollutants. To this end, a nonpolluted agricultural soil was amended with 0.5, 2, and 5% of the following four amendments: powder activated carbon (PAC), granular activated carbon, corn stover biochar, and ferric oxyhydroxide powder, which have previously been proven to sequester pollutants in soil. The resulting immediate effects (i.e., without aging the mixtures before carrying out tests) on the springtail Folsomia candida, the earthworm species Aporectodea caliginosa and Eisenia fetida, the marine bacteria Vibrio fischeri, a suite of ten prokaryotic species, and a eukaryote (the yeast species Pichia anomalia) were investigated. Reproduction of F. candida was significantly increased compared to the unamended soil when 2% biochar was added to it. None of the treatments caused a negative effect on reproduction. All amendments had a deleterious effect on the growth of A. caliginosa when compared to the unamended soil, except the 0.5% amendment of biochar. In avoidance tests, E. fetida preferred biochar compared to all other amendments including the unamended soil. All amendments reduced the inhibition of luminescence to V. fischeri, i.e., were beneficial for the bacteria, with PAC showing the greatest improvement. The effects of the amendments on the suite of prokaryotic species and the eukaryote were variable, but overall the 2% biochar dose provided the most frequent positive effect on growth. It is concluded that the four soil amendments had variable but never strongly deleterious effects on the bacteria and invertebrates studied here during the respective recommended experimental test periods. PMID:23802136

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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

  9. Inhibition of the ferric uptake regulator by peptides derived from anti-FUR peptide aptamers: coupled theoretical and experimental approaches.

    Science.gov (United States)

    Cissé, Cheickna; Mathieu, Sophie V; Abeih, Mohamed B Ould; Flanagan, Lindsey; Vitale, Sylvia; Catty, Patrice; Boturyn, Didier; Michaud-Soret, Isabelle; Crouzy, Serge

    2014-12-19

    The FUR protein (ferric uptake regulator) is an iron-dependent global transcriptional regulator. Specific to bacteria, FUR is an attractive antibacterial target since virulence is correlated to iron bioavailability. Recently, four anti-FUR peptide aptamers, composed of 13 amino acid variable loops inserted into a thioredoxinA scaffold, were identified, which were able to interact with Escherichia coli FUR (EcFUR), inhibit its binding to DNA and to decrease the virulence of pathogenic E. coli in a fly infection model. The first characterization of anti-FUR linear peptides (pF1 6 to 13 amino acids) derived from the variable part of the F1 anti-FUR peptide aptamer is described herein. Theoretical and experimental approaches, in original combination, were used to study interactions of these peptides with FUR in order to understand their mechanism of inhibition. After modeling EcFUR by homology, docking with Autodock was combined with molecular dynamics simulations in implicit solvent to take into account the flexibility of the partners. All calculations were cross-checked either with other programs or with experimental data. As a result, reliable structures of EcFUR and its complex with pF1 are given and an inhibition pocket formed by the groove between the two FUR subunits is proposed. The location of the pocket was validated through experimental mutation of key EcFUR residues at the site of proposed peptide interaction. Cyclisation of pF1, mimicking the peptide constraint in F1, improved inhibition. The details of the interactions between peptide and protein were analyzed and a mechanism of inhibition of these anti-FUR molecules is proposed.

  10. Positioning of bacterial chemoreceptors.

    Science.gov (United States)

    Jones, Christopher W; Armitage, Judith P

    2015-05-01

    For optimum growth, bacteria must adapt to their environment, and one way that many species do this is by moving towards favourable conditions. To do so requires mechanisms to both physically drive movement and provide directionality to this movement. The pathways that control this directionality comprise chemoreceptors, which, along with an adaptor protein (CheW) and kinase (CheA), form large hexagonal arrays. These arrays can be formed around transmembrane receptors, resulting in arrays embedded in the inner membrane, or they can comprise soluble receptors, forming arrays in the cytoplasm. Across bacterial species, chemoreceptor arrays (both transmembrane and soluble) are localised to a variety of positions within the cell; some species with multiple arrays demonstrate this variety within individual cells. In many cases, the positioning pattern of the arrays is linked to the need for segregation of arrays between daughter cells on division, ensuring the production of chemotactically competent progeny. Multiple mechanisms have evolved to drive this segregation, including stochastic self-assembly, cellular landmarks, and the utilisation of ParA homologues. The variety of mechanisms highlights the importance of chemotaxis to motile species.

  11. 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.

  12. 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

  13. Bacterial Communities: Interactions to Scale

    Directory of Open Access Journals (Sweden)

    Reed M. Stubbendieck

    2016-08-01

    Full Text Available 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.

  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. 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.

  16. 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...

  17. 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)...

  18. 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

  19. 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)

  20. 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.

  1. Sodium Ferric Gluconate Injection

    Science.gov (United States)

    ... gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of red blood ... pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or ...

  2. ION VATAMANU

    Directory of Open Access Journals (Sweden)

    l. Povar

    2012-12-01

    Full Text Available Ion Vatamanu was a chemist, writer and public figure. He was equally passionate about both his chosen fields of activity: chemistry and poetry. Chemistry, with its perfect equilibrium of logic and precision, provided inspiration for lyrical creativity, whereas poetry writing enlivened his imagination and passion for chemistry. He loved his parents. He adored his wife Elena, whom he often gifted a sea of flowers. He loved his daughters Mihaela, Mariana, and Leontina. He loved life, and he loved people.

  3. 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+).

  4. 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.

  5. 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

  6. Effects of urea and acetic acid on the heme axial ligation structure of ferric myoglobin at very acidic pH.

    Science.gov (United States)

    Droghetti, Enrica; Sumithran, Suganya; Sono, Masanori; Antalík, Marián; Fedurco, Milan; Dawson, John H; Smulevich, Giulietta

    2009-09-01

    The heme iron coordination of ferric myoglobin (Mb) in the presence of 9.0M urea and 8.0M acetic acid at acidic pH values has been probed by electronic absorption, magnetic circular dichroism and resonance Raman spectroscopic techniques. Unlike Mb at pH 2.0, where heme is not released from the protein despite the acid denaturation and the loss of the axial ligand, upon increasing the concentration of either urea or acetic acid, a spin state change is observed, and a novel, non-native six-coordinated high-spin species prevails, where heme is released from the protein.

  7. Similarity of the Surface Reactivity of Hydrous Ferric Oxide and Hematite: Sorption and Redox of U(VI) and Fe(II)

    Energy Technology Data Exchange (ETDEWEB)

    Je-Hun Jang; Dempsey, Brian A.; Burgos, William D.; Yeh, George; Roden, Eric

    2004-03-17

    Hydrous Ferric Oxide (HFO) vs. Hematite--Thermodynamically distinctive bulk phases, but the surfaces could be similar due to hydration of the interface. Hypothesis--The surface of HFO is energetically similar to the surface of hematite. Objective--Compare the reactions of HFO and hematite with U(VI) and Fe(II). Experimental--The reactions of interests were (1) preparation of sub-micron hematite, (2) sorption of U(VI), and (3) redox of U(VI) and Fe(II) with HFO or hematite.

  8. Ion Beam Extraction by Discrete Ion Focusing

    DEFF Research Database (Denmark)

    2010-01-01

    An apparatus (900) and methods are disclosed for ion beam extraction. In an implementation, the apparatus includes a plasma source (or plasma) (802) and an ion extractor (804). The plasma source is adapted to generate ions and the ion extractor is immersed in the plasma source to extract a fraction...... of the generated ions. The ion extractor is surrounded by a space charge (810) formed at least in part by the extracted ions. The ion extractor includes a biased electrode (806) forming an interface with an insulator (808). The interface is customized to form a strongly curved potential distribution (812......) in the space-charge surrounding the ion extractor. The strongly curved potential distribution focuses the extracted ions towards an opening (814) on a surface of the biased electrode thereby resulting in an ion beam....

  9. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Sujatha Srinivasan

    2008-01-01

    Full Text Available 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.

  10. Channel-forming bacterial toxins in biosensing and macromolecule delivery.

    Science.gov (United States)

    Gurnev, Philip A; Nestorovich, Ekaterina M

    2014-08-21

    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.

  11. 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.

  12. Instrumentation: Ion Chromatography.

    Science.gov (United States)

    Fritz, James S.

    1987-01-01

    Discusses the importance of ion chromatography in separating and measuring anions. The principles of ion exchange are presented, along with some applications of ion chromatography in industry. Ion chromatography systems are described, as well as ion pair and ion exclusion chromatography, column packings, detectors, and programming. (TW)

  13. 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

  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. Uranium potentiometer determination in inactive atmosphere with ferric sulfate; Determinacion poteniometrica de uranio en atmosfera inerte con sulfato ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Cellini, R.; Alonso Lopez, J.

    1956-07-01

    Potentiometric titration of Uranium with (SO{sub 4}){sub 3} Fe{sub 2}, 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)

  16. Apparent Mobilities of Na+,K+ and Ca2+ Ions in Variable Charge Soil Colloid Systems

    Institute of Scientific and Technical Information of China (English)

    LICHENG-BAO

    1992-01-01

    In this paper a simple method for determination of the apparent mobility of cation in a soil colloid system was described.With this method apparent mobilities of Na+,K+,and Ca2+ ions in the systems of the ferric luvisol,acrisol,and ferralsol were determined,and the reduction percentages of the mobilities were calculated.The results showed that the apparent mobilities of different cations at the same normalitey in a given soil system were in the order UNa>UK>UCa;those of the same cations among different soil systems were in the order ferralsol> acrisol> ferric luvisol,but the reduction percentages were in a reverse order,which among different cations at the same normality was Ca2+>K+>Na+ for ferric luvisol and acrisol systems,but was K+>Ca2+>Na+ for farralsol system.These results were interpreted in terms of different amounts of negative charge the clay fraction of different soils carries,and different mechanisms by which the soils adsorb the cations.

  17. Antibiotic resistance of bacterial biofilms

    DEFF Research Database (Denmark)

    Hoiby, N.; Bjarnsholt, T.; Givskov, M.;

    2010-01-01

    A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis...... and other components of the body's defence system. The persistence of, for example, staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infection in cystic fibrosis patients is caused by biofilm-growing mucoid strains....... Characteristically, gradients of nutrients and oxygen exist from the top to the bottom of biofilms and these gradients are associated with decreased bacterial metabolic activity and increased doubling times of the bacterial cells; it is these more or less dormant cells that are responsible for some of the tolerance...

  18. 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

  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. Clinical applications of bacterial glycoproteins.

    Science.gov (United States)

    Fulton, Kelly M; Smith, Jeffrey C; Twine, Susan M

    2016-01-01

    There is an ongoing race between bacterial evolution and medical advances. Pathogens have the advantages of short generation times and horizontal gene transfer that enable rapid adaptation to new host environments and therapeutics that currently outpaces clinical research. Antibiotic resistance, the growing impact of nosocomial infections, cancer-causing bacteria, the risk of zoonosis, and the possibility of biowarfare all emphasize the increasingly urgent need for medical research focussed on bacterial pathogens. Bacterial glycoproteins are promising targets for alternative therapeutic intervention since they are often surface exposed, involved in host-pathogen interactions, required for virulence, and contain distinctive glycan structures. The potential exists to exploit these unique structures to improve clinical prevention, diagnosis, and treatment strategies. Translation of the potential in this field to actual clinical impact is an exciting prospect for fighting infectious diseases. PMID:26971465

  1. Comparative proteomic analysis of sulfur-oxidizing Acidithiobacillus ferrooxidans CCM 4253 cultures having lost the ability to couple anaerobic elemental sulfur oxidation with ferric iron reduction.

    Science.gov (United States)

    Kucera, Jiri; Sedo, Ondrej; Potesil, David; Janiczek, Oldrich; Zdrahal, Zbynek; Mandl, Martin

    2016-09-01

    In extremely acidic environments, ferric iron can be a thermodynamically favorable electron acceptor during elemental sulfur oxidation by some Acidithiobacillus spp. under anoxic conditions. Quantitative 2D-PAGE proteomic analysis of a resting cell suspension of a sulfur-grown Acidithiobacillus ferrooxidans CCM 4253 subculture that had lost its iron-reducing activity revealed 147 protein spots that were downregulated relative to an iron-reducing resting cell suspension of the antecedent sulfur-oxidizing culture and 111 that were upregulated. Tandem mass spectrometric analysis of strongly downregulated spots identified several physiologically important proteins that apparently play roles in ferrous iron oxidation, including the outer membrane cytochrome Cyc2 and rusticyanin. Other strongly repressed proteins were associated with sulfur metabolism, including heterodisulfide reductase, thiosulfate:quinone oxidoreductase and sulfide:quinone reductase. Transcript-level analyses revealed additional downregulation of other respiratory genes. Components of the iron-oxidizing system thus apparently play central roles in anaerobic sulfur oxidation coupled with ferric iron reduction in the studied microbial strain. PMID:27394989

  2. Ameliorative effect of polyphenols from Padina boergesenii against ferric nitrilotriacetate induced renal oxidative damage: With inhibition of oxidative hemolysis and in vitro free radicals.

    Science.gov (United States)

    Rajamani, Karthikeyan; Renju, V C; Sethupathy, S; Thirugnanasambandan, Somasundaram S

    2015-07-01

    The aim of this study was to evaluate the antioxidant activities of diethyl ether (DEE) and methanol (M) extracts from brown alga Padina boergesenii using in vitro and in vivo antioxidant assay, which may help to relate the antioxidant properties with the possible outline of its ameliorative effect. M extract showed higher radical scavenging activity through ferric reducing antioxidant power 139.11 µmol tannic acid equivalent/g; DPPH 71.32 ± 0.56%; deoxyribose radical 88.31 ± 0.47%, and total antioxidant activity 0.47 ± 0.02 mg ascorbic acid equivalents/g. Oxidative red blood cell (RBC) hemolysis inhibition rate was significantly higher in M extract (150 mg/kg body weight) in reference to total phenolic content (r = 0.935). Rats administered with DEE and M extracts (150 mg/kg body weight) for seven days before the administration of ferric nitrilotriacetate (9 mg of Fe/mg/kg bodyweight). Rats pretreated with extracts significantly changed the level of renal microsomal lipid peroxidation, glutathione, and antioxidant enzymes in post-mitochondrial supernatant (P rutin with reference to retardation factor (Rf ) in both the extracts. These findings support the source of polyphenols (rutin) from P. boergesenii had potent antioxidant activity; further work on isolation of bioactive compounds can be channeled to develop as a natural antioxidant.

  3. 新型Lewis酸铁钾矾催化合成己酸乙酯%Catalytic Synthesis of Ethyl Caproate over New Lewis Acid Ferric Potassium Alum

    Institute of Scientific and Technical Information of China (English)

    郭小丹; 张福捐

    2012-01-01

    新型Lewis酸铁钾矾催化己酸和乙醇合成反应生成己酸乙酯,其性能优于硫酸,并且是一种绿色催化剂.研究了催化剂的用量、酸醇摩尔比、反应时间对酯化反应的影响.实验结果表明,较佳的反应条件为:催化剂用量1.0 g/0.05 mol己酸,酸醇物质的量比为1∶2.4,反应时间为100 min,此条件下己酸转化率为94.3%.%Ethyl caproate was synthesized from hexanoic acid and ethyl alcohol with new Lewis acid ferric potassium alum as catalyst.The factors of influencing esterification rate were investigated.The results showed that ferric potassium alum was a good green catalyst for synthesis of ethyl caproate.The optimum conditions were:molar ratio of hexanoic acid to ethyl alcohol was 1∶ 2.4,amount of catalyst was 1.0 g /0.05 mol hexanoic acid,the water-carrying toluene was 10 mL,and the reaction time was 100 min.The highest esterification rate was 94.3%,and the catalyst can be recycled for many times.

  4. 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...

  5. 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.

  6. ION GUN

    Science.gov (United States)

    Dandl, R.A.

    1961-10-24

    An ion gun is described for the production of an electrically neutral ionized plasma. The ion gun comprises an anode and a cathode mounted in concentric relationship with a narrow annulus between. The facing surfaces of the rear portions of the anode and cathode are recessed to form an annular manifold. Positioned within this manifold is an annular intermediate electrode aligned with the an nulus between the anode and cathode. Gas is fed to the manifold and an arc discharge is established between the anode and cathode. The gas is then withdrawn from the manifold through the annulus between the anode and cathode by a pressure differential. The gas is then ionized by the arc discharge across the annulus. The ionized gas is withdrawn from the annulus by the combined effects of the pressure differential and a collimating magnetic field. In a 3000 gauss magnetic field, an arc voltage of 1800 volts, and an arc current of 0.2 amp, a plasma of about 3 x 10/sup 11/ particles/cc is obtained. (AEC)

  7. Biodegradation of ion-exchange media

    International Nuclear Information System (INIS)

    Ion-exchange media, both bead resins and powdered filter media, are used in nuclear power plants to remove radioactivity from process water prior to reuse or environmental discharge. Since the ion- exchange media are made from synthetic hydrocarbon-based polymers, they may be susceptible to damage from biological activity. The purpose of this study was to investigate some of the more basic aspects of biodegradation of ion-exchange media, specifically to evaluate the ability of microorganisms to utilize the ion-exchange media or materials sorbed on them as a food source. The ASTM-G22 test, alone and combined with the Bartha Pramer respirometric method, failed to indicate the biodegradability of the ion-exchange media. The limitation of these methods was that they used a single test organism. In later phases of this study, a mixed microbial culture was grown from resin waste samples obtained from the BNL High Flux Beam Reactor. These microorganisms were used to evaluate the susceptibility of different types of ion-exchange media to biological attack. Qualitative assessments of biodegradability were based on visual observations of culture growths. Greater susceptibility was associated with increased turbidity in solution indicative of bacterial growth, and more luxuriant fungal mycelial growth in solution or directly on the ion-exchange resin beads. 21 refs., 9 figs., 18 tabs

  8. 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

  9. 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...

  10. Hybrid-fuel bacterial flagellar motors in Escherichia coli.

    Science.gov (United States)

    Sowa, Yoshiyuki; Homma, Michio; Ishijima, Akihiko; Berry, Richard M

    2014-03-01

    The bacterial flagellar motor rotates driven by an electrochemical ion gradient across the cytoplasmic membrane, either H(+) or Na(+) ions. The motor consists of a rotor ∼50 nm in diameter surrounded by multiple torque-generating ion-conducting stator units. Stator units exchange spontaneously between the motor and a pool in the cytoplasmic membrane on a timescale of minutes, and their stability in the motor is dependent upon the ion gradient. We report a genetically engineered hybrid-fuel flagellar motor in Escherichia coli that contains both H(+)- and Na(+)-driven stator components and runs on both types of ion gradient. We controlled the number of each type of stator unit in the motor by protein expression levels and Na(+) concentration ([Na(+)]), using speed changes of single motors driving 1-μm polystyrene beads to determine stator unit numbers. De-energized motors changed from locked to freely rotating on a timescale similar to that of spontaneous stator unit exchange. Hybrid motor speed is simply the sum of speeds attributable to individual stator units of each type. With Na(+) and H(+) stator components expressed at high and medium levels, respectively, Na(+) stator units dominate at high [Na(+)] and are replaced by H(+) units when Na(+) is removed. Thus, competition between stator units for spaces in a motor and sensitivity of each type to its own ion gradient combine to allow hybrid motors to adapt to the prevailing ion gradient. We speculate that a similar process may occur in species that naturally express both H(+) and Na(+) stator components sharing a common rotor. PMID:24550452

  11. 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.

  12. 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...

  13. 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.

  14. A Program Against Bacterial Bioterrorism

    DEFF Research Database (Denmark)

    Kemp, Michael; Dargis, Rimtas; Andresen, Keld;

    2012-01-01

    In 2002 it was decided to establish laboratory facilities in Denmark for diagnosing agents associated with bioterrorism in order to make an immediate appropriate response to the release of such agents possible. Molecular assays for detection of specific agents and molecular and proteomic techniques...... for bacterial infections not associated with bioterrorism that are difficult to culture or identify....

  15. Molecular Mechanisms Underlying Bacterial Persisters

    DEFF Research Database (Denmark)

    Maisonneuve, Etienne; Gerdes, Kenn

    2014-01-01

    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...

  16. 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

  17. 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.

  18. Temperature and dose dependence of defect complex formation with ion implanted Mn/Fe in ZnO

    CERN Document Server

    Mølholt, T E; Gunnlaugsson, H P; Bharuth-Ram, K; Fanciulli, M; Gíslason, H P; Johnston, K; Kobayashi, Y; Langouche, G; Masenda, H; Naidoo, D; Ólafsson, S; Sielemann, R; Weyer, G

    2009-01-01

    57Fe Mössbauer spectroscopy following ion implantation of radioactive 57Mn+ ( T1/2=85.4 s) has been applied to study the formation of Fe/Mn implantation-induced defects in ZnO at temperatures between 319 and 390 K. The formation of ferric iron–vacancy complexes is found to depend strongly on the implanted dose and to be faster and more efficient at higher temperatures. The results at these temperatures suggest the mobility of the Zn vacancy, together with vacancy trapping at the substitutional Mn/Fe impurities are responsible for the formation of Fe–VZn complexes

  19. 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

  20. 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

  1. 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...

  2. 共沉淀氢氧化铁酸奶的研制%Preparation of Co-precipitation Ferric Hydroxide Yogurt

    Institute of Scientific and Technical Information of China (English)

    洪南华; 李诚; 吴思慧

    2013-01-01

    以鲜牛奶为原料,通过添加适量的共沉淀氢氧化铁,以Hansen公司的YF-L812为发酵剂,对制备共沉淀氢氧化铁发酵乳进行了研究。通过单因素试验和正交试验,确定了最佳工艺条件。结果表明,当铁添加量为20 mg/kg,接种量为5%,白砂糖添加量为6%(均为质量分数)在42℃条件下发酵5 h即可得到优质的共沉淀氢氧化铁酸奶制品。在此条件下制备的酸奶与未添加共沉淀氢氧化铁酸奶在7 d保藏期内,除酸度有显著差异外,乳酸菌数和TBA值均无显著性差异。%For preparation of co-precipitation ferric hydroxide yogurt , fresh milk was used as a raw material and an appropriate amount of co-precipitation ferric hydroxide ,the YF-L812 starter culture from Hansen corporation were added to product yogurt. Based on one-factor-at-a-time investigations ,orthogonal array designs were employed to optimize the fermentation conditions.The results showed that ,adding 20 mg/kg iron, 5 % inoculums size,6 % sugar and at 42 ℃ 5 hours fermentation time can achieve the high quality co-precipitation ferric hydroxide yogurt.During the 7 days storage ,between fortified and unfortified yogurt ,there was no significant differences in the number of lactic acid bacteria and the TBA value ,only in the acidity.

  3. Distribution of Triplet Separators in Bacterial Genomes

    Institute of Scientific and Technical Information of China (English)

    HU Rui; ZHENG Wei-Mou

    2001-01-01

    Distributions of triplet separator lengths for two bacterial complete genomes are analyzed. The theoretical distributions for the independent random sequence and the first-order Markov chain are derived and compared with the distributions of the bacterial genomes. A prominent double band structure, which does not exist in the theoretical distributions, is observed in the bacterial distributions for most triplets.``

  4. Rational Design of Metal Ion Sequestering Agents

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, Kenneth N.

    2000-09-30

    The discriminate bonding of metal ions is a challenge to the synthetic chemist and a phenomenon of considerable practical importance.1 An important feature of many technical applications is the specific or preferential binding of a single metal ion in the presence of many metals. Examples range from large-volume uses (e.g. ferric EDTA as a plant food, calcium complexing agents as water softeners or anticaking formulations) to very high technology applications (technetium complexation in radiopharmaceuticals, synthetic metalloenzymes). We are interested in efficient and discriminate binding of actinides for waste stream remediation. Actinides represent a major and long-lived contaminant in nuclear waste. While the separation of actinides from other radioactive components of waste, such as Sr and Cs, is relatively well established, the separation of actinides from each other and in complex solutions (e.g. those found in tank wastes) is not as well resolved. The challenge of designing metal-specific (actinide) ligands is facilitated by examples from nature. Bacteria synthesize Fe(III)-specific ligands, called siderophores, to sequester Fe(III) from the environment and return it to the cell. The similarities between Fe(III) and Pu(IV) (their charge-to-size ratios and acidity), make the siderophores prototypical for designing actinide-specific ligands. The chelating groups present in siderophores are usually hydroxamic acids and catecholamides. We have developed derivatives of these natural products which have improved properties. The catechol derivatives are the 2,3-dihydroxyterephthalamides (TAMs), and 3,4-dihydroxysulfonamides (SFAMs), and the hydroxamic acid derivatives are three isomers of hydroxypyridinones, 1,2- HOPO, 3,2-HOPO, and 3,4-HOPO. All of these ligands are attached to molecular backbones by amides and a very important feature of HOPO and CAM ligands is a strong hydrogen bonds formed between the amide proton and the adjacent phenolic oxygen in the metal

  5. Ion funnel ion trap and process

    Science.gov (United States)

    Belov, Mikhail E [Richland, WA; Ibrahim, Yehia M [Richland, WA; Clowers, Biran H [West Richland, WA; Prior, David C [Hermiston, OR; Smith, Richard D [Richland, WA

    2011-02-15

    An ion funnel trap is described that includes a inlet portion, a trapping portion, and a outlet portion that couples, in normal operation, with an ion funnel. The ion trap operates efficiently at a pressure of .about.1 Torr and provides for: 1) removal of low mass-to-charge (m/z) ion species, 2) ion accumulation efficiency of up to 80%, 3) charge capacity of .about.10,000,000 elementary charges, 4) ion ejection time of 40 to 200 .mu.s, and 5) optimized variable ion accumulation times. Ion accumulation with low concentration peptide mixtures has shown an increase in analyte signal-to-noise ratios (SNR) of a factor of 30, and a greater than 10-fold improvement in SNR for multiply charged analytes.

  6. Preparation of Silver- and Zinc-Doped Mullite-Based Ceramics Showing Anti-Bacterial Biofilm Properties

    Directory of Open Access Journals (Sweden)

    Suhair Saleh

    2011-03-01

    Full Text Available Zinc- and silver-doped mullite ceramic discs were prepared and tested as potentially resistant materials against bacterial adhesion and biofilm formation. Elemental analysis and X-ray diffraction studies showed that zinc ions were incorporated in the structural framework of the mullite, while silver ions remained outside the mullite crystal lattice, which allowed their slow (0.02 ppm/24 hours leaching into the surrounding aqueous environment. In agreement with this behavior, silver-doped mullite showed potent resistance against surface attachment of Pseudomonas aeruginosa, while on the other hand, zinc-doped mullite failed to stop bacterial attachment.

  7. 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

  8. 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.

  9. 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...

  10. 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.

  11. 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...

  12. The problem of bacterial diarrhoea.

    Science.gov (United States)

    Harries, J T

    1976-01-01

    The reported incidence of "pathogenic" bacteria, as judged by serotype, in the stools of children with acute diarrhoea has varied from 4 to 33% over the last twenty years. Techniques such as tissue culture provide a means for detecting enterotoxin-producing strains of bacteria, strains which often do not possess "pathogenic" serotypes. "Pathogenicity" requires redefinition, and the aetiological importance of bacteria in diarrhoea is probably considerably greater than previous reports have indicated. Colonization of the bowel by a pathogen will result in structural and/or mucosal abnormalities, and will depend on a series of complex interactions between the external environment, the pathogen, and the host and its resident bacterial flora. Enteropathogenic bacteria may be broadly classified as (i) invasive (e.g. Shigella, Salmonella and some Escherichia coli) which predominantly affect the distal bowel, or (ii) non-invasive (e.g. Vibrio cholerae and E. coli) which affect the proximal bowel. V. cholerae and E. coli elaborate heat-labile enterotoxins which activate adenylate cyclase and induce small intestinal secretion; the secretory effects of heat-stable E. coli and heat-labile Shigella dysenteriae enterotoxins are not accompanied by cyclase activation. The two major complications of acute diarrhoea are (i) hypernatraemic dehydration with its attendant neurological, renal and vascular lesions, and (ii) protracted diarrhoea which may lead to severe malnutrition. Deconjugation of bile salts and colonization of the small bowel with toxigenic strains of E. coli may be important in the pathophysiology of the protracted diarrhoea syndrome. The control of bacterial diarrhoea requires a corrdinated political, educational, social, public health and scientific attack. Bacterial diarrhoea is a major health problem throughout the world, and carries an appreciable morbidity and mortality. This is particularly the case during infancy, and in those developing parts of the world

  13. 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. ...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. Radioisotopic synovectomy using ferric hydroxide macroaggregated for chronic arthritis treatment; Sinovectomia radioisotopica atraves do macroagregado de hidroxido ferrico para tratamento da artrite cronica

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Carla Flavia; Campos, Tarcisio P.R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Ciencias e Tecnicas Nucleares] E-mail: campos@nuclear.ufmg.br

    2002-07-01

    Synovectomy radioisotopic is an arthritis treatment used in specific clinical conditions whose main goal is to sterilized the synovia. This treatment has specific and precise indications and it is considered to have an adequate response. The present work presents a modeling of an articulation (joint) based on its real geometric anatomy and chemical constitution. The internal dosimetry is evaluated by the Monte Carlo Code. The majority of the radionuclides were considered in the simulations. The syntheses of the ferric hydroxide macroaggregates with dysprosium and samarium have been prepared (Dy{sup 165}-MHF and Sm{sup 153}-MHF). Obtaining the cintilographic images of rabbits in which Dy{sup 165}-MHF is injected is in progress. Biodistribution studies in addition with the internal dosimetry will certify the dose in the membrane of the synovia. (author)

  1. 食盐抗结剂柠檬酸铁铵的合成方法%Synthesis of Ferric Ammonium Citrate

    Institute of Scientific and Technical Information of China (English)

    王宇; 闫静; 王学炜; 李泽淳

    2014-01-01

    Ferrous sulfate was oxidated by hydrogen peroxide to synthesize iron hydroxide, then iron hydroxide reacted with ammonium citrate to prepare ferric ammonium citrate. The conditions which affected the iron content of product, included preparation of iron hydroxide, reaction time, temperature and drying methods, were discussed. The optimum technological conditions were obtained.%以硫酸亚铁为原料,双氧水为氧化剂制备氢氧化铁,再与柠檬酸铵反应制得柠檬酸铁铵。考察了氢氧化铁制备条件、反应时间、反应温度、干燥方式对产品含铁量的影响,确定了最佳工艺条件。

  2. Effects of ammonium-ferric(III)-hexacyano-ferrate(II) and faeces addition on yield and soil-plant transfer of radiocaesium to rye-grass

    Energy Technology Data Exchange (ETDEWEB)

    Vandenhove, Hildegarde; Van Hees, May; De Brouwer, Simon; Vandecasteele, Christian [SCK-CEN, Mol (Belgium)

    1997-12-31

    AFCF [ammonium-ferric (III)-hexacyano-ferrate (II)] was shown to be an effective countermeasure against radiocaesium uptake by domestic animals. Following the addition of AFCF and faeces to a sandy farm soil, we evaluate here radiocaesium transfer to rye-grass as well as grass yield in a pot experiment under greenhouse conditions. Sheep faeces and/or soil were artificially contaminated with {sup 137}Cs or {sup 134}Cs, respectively. Radiocaesium from both soil and faeces was equally absorbed by rye-grass. AFCF, at concentrations of 1 gm{sup -2} soil, was not deleterious for plant growth. AFCF is, furthermore, an effective countermeasure for radiocaesium soil-plant transfer. The AFCF applications at about 1 g AFCF m{sup -2} on the sandy soil resulted in a fourfold reduction of the radiocaesium transfer to rye-grass. (Author).

  3. 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.

  4. Cytochemical Differences in Bacterial Glycocalyx

    Science.gov (United States)

    Krautgartner, Wolf Dietrich; Vitkov, Ljubomir; Hannig, Matthias; Pelz, Klaus; Stoiber, Walter

    2005-02-01

    To examine new cytochemical aspects of the bacterial adhesion, a strain 41452/01 of the oral commensal Streptococcus sanguis and a wild strain of Staphylococcus aureus were grown with and without sucrose supplementation for 6 days. Osmiumtetraoxyde (OsO4), uranyl acetate (UA), ruthenium red (RR), cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs), and the tannic acid-metal salt technique (TAMST) were applied for electron microscopy. Cytochemically, only RR-positive fimbriae in S. sanguis were visualized. By contrast, some types of fimbriae staining were observed in S. aureus glycocalyx: RR-positive, OsO4-positive, tannophilic and CB-positive with ceasing point at 0.3 M MgCl2. The CB staining with CEC, used for the first time for visualization of glycoproteins of bacterial glycocalyx, also reveals intacellular CB-positive substances-probably the monomeric molecules, that is, subunits forming the fimbriae via extracellular assembly. Thus, glycosylated components of the biofilm matrix can be reliably related to single cells. The visualization of intracellular components by CB with CEC enables clear distinction between S. aureus and other bacteria, which do not produce CB-positive substances. The small quantities of tannophilic substances found in S. aureus makes the use of TAMST for the same purpose difficult. The present work protocol enables, for the first time, a partial cytochemical differentiation of the bacterial glycocalyx.

  5. Decrease of Staphylococcal adhesion on surgical stainless steel after Si ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Braceras, Iñigo, E-mail: inigo.braceras@tecnalia.com [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Pacha-Olivenza, Miguel A. [CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Universidad de Extremadura, Departamento de Física Aplicada, Facultad de Ciencias, Av. Elvas s/n, 06006 Badajoz (Spain); Calzado-Martín, Alicia [Hospital Universitario La Paz-IdiPAZ, Paseo de la Castellana 261, 28046 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Multigner, Marta [Centro Nacional de Investigaciones Metalúrgicas, CENIM-CSIC, Avda Gregorio del Amo 8, 28040 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Vera, Carolina [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Broncano, Luis Labajos-; Gallardo-Moreno, Amparo M. [Universidad de Extremadura, Departamento de Física Aplicada, Facultad de Ciencias, Av. Elvas s/n, 06006 Badajoz (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); González-Carrasco, José Luis [Centro Nacional de Investigaciones Metalúrgicas, CENIM-CSIC, Avda Gregorio del Amo 8, 28040 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); Vilaboa, Nuria [Hospital Universitario La Paz-IdiPAZ, Paseo de la Castellana 261, 28046 Madrid (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) (Spain); and others

    2014-08-15

    Highlights: • Si ion implantation of AISI 316LVM medical grade alloy might reduce bacterial adhesion and colonization. • Si ion implantation does not impair the attachment, viability and matrix maturation of human mesenchymal stem cells. • Nano-topography and surface chemistry changes account for the Si ion implantation induced effects. - Abstract: 316LVM austenitic stainless steel is often the material of choice on temporal musculoskeletal implants and surgical tools as it combines good mechanical properties and acceptable corrosion resistance to the physiologic media, being additionally relatively inexpensive. This study has aimed at improving the resistance to bacterial colonization of this surgical stainless steel, without compromising its biocompatibility and resistance. To achieve this aim, the effect of Si ion implantation on 316LVM has been studied. First, the effect of the ion implantation parameters (50 keV; fluence: 2.5–5 × 10{sup 16} ions/cm{sup 2}; angle of incidence: 45–90°) has been assessed in terms of depth profiling of chemical composition by XPS and nano-topography evaluation by AFM. The in vitro biocompatibility of the alloy has been evaluated with human mesenchymal stem cells. Finally, bacterial adhesion of Staphylococcus epidermidis and Staphylococcus aureus on these surfaces has been assessed. Reduction of bacterial adhesion on Si implanted 316LVM is dependent on the implantation conditions as well as the features of the bacterial strains, offering a promising implantable biomaterial in terms of biocompatibility, mechanical properties and resistance to bacterial colonization. The effects of surface composition and nano-topography on bacterial adhesion, directly related to ion implantation conditions, are also discussed.

  6. Evidence for polynuclear aggregates of ferric daunomycin. A Mössbauer, EPR, X-ray absorption spectroscopy and magnetic susceptibility study.

    Science.gov (United States)

    Matzanke, B F; Bill, E; Butzlaff, C; Trautwein, A X; Winkler, H; Hermes, C; Nolting, H F; Barbieri, R; Russo, U

    1992-07-15

    The interaction of the antitumor agent daunomycin (DN) with ferric iron has been analysed by Mössbauer spectroscopy, EPR, extended X-ray absorption fine structure (EXAFS), and magnetic susceptibility measurements. In contrast to literature data, at millimolar iron and anthracycline concentrations no solitary Fe(DN)3 complexes are formed in appreciable amounts. The Mössbauer spectroscopic analysis revealed severe dependencies on temperature, on the preparation procedure, the time allowed for equilibration, and on the metal/ligand ratio. The Mössbauer spectra exhibit two components: a broad magnetic sextet and a quadrupole doublet at an Fe/DN molar ratio of 1:3 and exclusively a doublet at a molar ratio of 1:20, indicating an equilibrium of these two spectral components. The EPR spectra are dominated by a signal at g(eff) = 2. Double integration of the EPR signals enabled the determination of their spin density and a correlation between EPR and Mössbauer spectra. The Mössbauer sextet species is EPR invisible and corresponds to magnetically ordered polynuclear aggregates with high magnetic anisotropy. EXAFS and susceptibility measurements provide additional evidence for the formation of polynuclear aggregates of ferric daunomycin. The quadrupole doublet species in the Mössbauer spectra correlates with the g = 2 signal in EPR. This species is also related to a magnetically ordered system, exhibiting, however, superparamagnetic behavior due to less magnetic anisotropy. Since daunomycin forms dimers in aqueous solution at millimolar concentrations, we conclude that the cooperative phenomena observed in EPR and Mössbauer spectra are a consequence of its stacking effects. PMID:1321721

  7. Iron deficiency up-regulates iron absorption from ferrous sulphate but not ferric pyrophosphate and consequently food fortification with ferrous sulphate has relatively greater efficacy in iron-deficient individuals

    NARCIS (Netherlands)

    Zimmermann, M.B.; Biebinger, R.; Egli, I.; Zeder, C.; Hurrell, R.F.

    2011-01-01

    Fe absorption from water-soluble forms of Fe is inversely proportional to Fe status in humans. Whether this is true for poorly soluble Fe compounds is uncertain. Our objectives were therefore (1) to compare the up-regulation of Fe absorption at low Fe status from ferrous sulphate (FS) and ferric pyr

  8. K(+) versus Na(+) ions in a K channel selectivity filter: a simulation study.

    OpenAIRE

    Shrivastava, Indira H.; Tieleman, D. Peter; Biggin, Philip C; Sansom, Mark S P

    2002-01-01

    Molecular dynamics simulations of a bacterial potassium channel (KcsA) embedded in a phospholipid bilayer reveal significant differences in interactions of the selectivity filter with K(+) compared with Na(+) ions. K(+) ions and water molecules within the filter undergo concerted single-file motion in which they translocate between adjacent sites within the filter on a nanosecond timescale. In contrast, Na(+) ions remain bound to sites within the filter and do not exhibit translocation on a n...

  9. Bacterial adhesion and biofilms on surfaces

    Institute of Scientific and Technical Information of China (English)

    Trevor Roger Garrett; Manmohan Bhakoo; Zhibing Zhang

    2008-01-01

    Bacterial adhesion has become a significant problem in industry and in the domicile,and much research has been done for deeper understanding of the processes involved.A generic biological model of bacterial adhesion and population growth called the bacterial biofilm growth cycle,has been described and modified many times.The biofilm growth cycle encompasses bacterial adhesion at all levels,starting with the initial physical attraction of bacteria to a substrate,and ending with the eventual liberation of cell dusters from the biofilm matrix.When describing bacterial adhesion one is simply describing one or more stages of biofilm development,neglecting the fact that the population may not reach maturity.This article provides an overview of bacterial adhesion.cites examples of how bac-terial adhesion affects industry and summarises methods and instrumentation used to improve our understanding of the adhesive prop-erties of bacteria.

  10. Beetroot-Pigment-Derived Colorimetric Sensor for Detection of Calcium Dipicolinate in Bacterial Spores

    OpenAIRE

    Letícia Christina Pires Gonçalves; Sandra Maria Da Silva; DeRose, Paul C.; Rômulo Augusto Ando; Erick Leite Bastos

    2013-01-01

    In this proof-of-concept study, we describe the use of the main red beet pigment betanin for the quantification of calcium dipicolinate in bacterial spores, including Bacillus anthracis. In the presence of europium(III) ions, betanin is converted to a water-soluble, non-luminescent orange 1∶1 complex with a stability constant of 1.4 × 10(5) L mol(-1). The addition of calcium dipicolinate, largely found in bacterial spores, changes the color of the aqueous solution of [Eu(Bn)(+)] from orange t...

  11. Ferric carboxymaltose with or without erythropoietin for the prevention of red-cell transfusions in the perioperative period of osteoporotic hip fractures: a randomized contolled trial. The PAHFRAC-01 project

    Directory of Open Access Journals (Sweden)

    Bernabeu-Wittel Máximo

    2012-02-01

    Full Text Available Abstract Background Around one third to one half of patients with hip fractures require red-cell pack transfusion. The increasing incidence of hip fracture has also raised the need for this scarce resource. Additionally, red-cell pack transfusions are not without complications which may involve excessive morbidity and mortality. This makes it necessary to develop blood-saving strategies. Our objective was to assess safety, efficacy, and cost-effictveness of combined treatment of i.v. ferric carboxymaltose and erythropoietin (EPOFE arm versus i.v. ferric carboxymaltose (FE arm versus a placebo (PLACEBO arm in reducing the percentage of patients who receive blood transfusions, as well as mortality in the perioperative period of hip fracture intervention. Methods/Design Multicentric, phase III, randomized, controlled, double blinded, parallel groups clinical trial. Patients > 65 years admitted to hospital with a hip fracture will be eligible to participate. Patients will be treated with either a single dosage of i.v. ferric carboxymaltose of 1 g and subcutaneous erythropoietin (40.000 IU, or i.v. ferric carboxymaltose and subcutaneous placebo, or i.v. placebo and subcutaneous placebo. Follow-up will be performed until 60 days after discharge, assessing transfusion needs, morbidity, mortality, safety, costs, and health-related quality of life. Intention to treat, as well as per protocol, and incremental cost-effectiveness analysis will be performed. The number of recruited patients per arm is set at 102, a total of 306 patients. Discussion We think that this trial will contribute to the knowledge about the safety and efficacy of ferric carboxymaltose with/without erythropoietin in preventing red-cell pack transfusions in patients with hip fracture. ClinicalTrials.gov identifier: NCT01154491.

  12. Structural transformations of heat-treated bacterial iron oxide

    International Nuclear Information System (INIS)

    A bacterial siliceous iron oxide microtubule (diameter: ca. 1 μm, 15Fe2O3·8SiO2·P2O5·30H2O) produced by Leptothrix ochracea was heat treated in air and its structural transformation was investigated in detail by microscopy, diffractometry, and spectroscopy. Although the heat-treated bacterial iron oxide retained its original microtubular structure, its nanoscopic, middle-range, and local structures changed drastically. Upon heat treatment, nanosized pores were formed and their size changed depending on temperature. The Fe–O–Si linkages were gradually cleaved with increasing temperature, causing the progressive separation of Fe and Si ions into iron oxide and amorphous silicate phases, respectively. Concomitantly, global connectivity and local structure of FeO6 octahedra in the iron oxide nanoparticles systematically changed depending on temperature. These comprehensive investigations clearly revealed various structural changes of the bacterial iron oxide which is an important guideline for the future exploration of novel bio-inspired materials. - Highlights: • Structural transformation of a bacterial iron oxide microtubule was investigated. • Si–O–Fe was cleaved with increasing temperature to form α-Fe2O3/silicate composite. • Crystallization to 2Fh started at 500 °C to give α-Fe2O3 >700 °C. • FeO6 octahedra were highly distorted <500 °C. • Formation of face-sharing FeO6 was promoted >500 °C, releasing the local strain of FeO6

  13. Structural transformations of heat-treated bacterial iron oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Hideki, E-mail: hideki-h@cc.okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530 (Japan); JST, CREST, Okayama 700-8530 (Japan); Fujii, Tatsuo [Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530 (Japan); Kohara, Shinji [Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198 (Japan); Nakanishi, Koji [Office of Society-Academia Collaboration for Innovation, Kyoto University, Uji 611-0011 (Japan); Yogi, Chihiro [SR Center, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan); Peterlik, Herwig [Faculty of Physics, University of Vienna, A-1090 Vienna (Austria); Nakanishi, Makoto [Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530 (Japan); Takada, Jun [Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530 (Japan); JST, CREST, Okayama 700-8530 (Japan)

    2015-04-01

    A bacterial siliceous iron oxide microtubule (diameter: ca. 1 μm, 15Fe{sub 2}O{sub 3}·8SiO{sub 2}·P{sub 2}O{sub 5}·30H{sub 2}O) produced by Leptothrix ochracea was heat treated in air and its structural transformation was investigated in detail by microscopy, diffractometry, and spectroscopy. Although the heat-treated bacterial iron oxide retained its original microtubular structure, its nanoscopic, middle-range, and local structures changed drastically. Upon heat treatment, nanosized pores were formed and their size changed depending on temperature. The Fe–O–Si linkages were gradually cleaved with increasing temperature, causing the progressive separation of Fe and Si ions into iron oxide and amorphous silicate phases, respectively. Concomitantly, global connectivity and local structure of FeO{sub 6} octahedra in the iron oxide nanoparticles systematically changed depending on temperature. These comprehensive investigations clearly revealed various structural changes of the bacterial iron oxide which is an important guideline for the future exploration of novel bio-inspired materials. - Highlights: • Structural transformation of a bacterial iron oxide microtubule was investigated. • Si–O–Fe was cleaved with increasing temperature to form α-Fe{sub 2}O{sub 3}/silicate composite. • Crystallization to 2Fh started at 500 °C to give α-Fe{sub 2}O{sub 3} >700 °C. • FeO{sub 6} octahedra were highly distorted <500 °C. • Formation of face-sharing FeO{sub 6} was promoted >500 °C, releasing the local strain of FeO{sub 6}.

  14. Exchange of rotor components in functioning bacterial flagellar motor

    International Nuclear Information System (INIS)

    The bacterial flagellar motor is a rotary motor driven by the electrochemical potential of a coupling ion. The interaction between a rotor and stator units is thought to generate torque. The overall structure of flagellar motor has been thought to be static, however, it was recently proved that stators are exchanged in a rotating motor. Understanding the dynamics of rotor components in functioning motor is important for the clarifying of working mechanism of bacterial flagellar motor. In this study, we focused on the dynamics and the turnover of rotor components in a functioning flagellar motor. Expression systems for GFP-FliN, FliM-GFP, and GFP-FliG were constructed, and each GFP-fusion was functionally incorporated into the flagellar motor. To investigate whether the rotor components are exchanged in a rotating motor, we performed fluorescence recovery after photobleaching experiments using total internal reflection fluorescence microscopy. After photobleaching, in a tethered cell producing GFP-FliN or FliM-GFP, the recovery of fluorescence at the rotational center was observed. However, in a cell producing GFP-FliG, no recovery of fluorescence was observed. The transition phase of fluorescence intensity after full or partially photobleaching allowed the turnover of FliN subunits to be calculated as 0.0007 s-1, meaning that FliN would be exchanged in tens of minutes. These novel findings indicate that a bacterial flagellar motor is not a static structure even in functioning state. This is the first report for the exchange of rotor components in a functioning bacterial flagellar motor.

  15. Preparation of Silver- and Zinc-Doped Mullite-Based Ceramics Showing Anti-Bacterial Biofilm Properties

    OpenAIRE

    Suhair Saleh; Mutasem O. Taha; Haddadin, Randa N.; Duá Marzooqa; Hamdallah Hodali

    2011-01-01

    Zinc- and silver-doped mullite ceramic discs were prepared and tested as potentially resistant materials against bacterial adhesion and biofilm formation. Elemental analysis and X-ray diffraction studies showed that zinc ions were incorporated in the structural framework of the mullite, while silver ions remained outside the mullite crystal lattice, which allowed their slow (0.02 ppm/24 hours) leaching into the surrounding aqueous environment. In agreement with this behavior, silver-doped mul...

  16. Anti-biofilm activity of Fe heavy ion irradiated polycarbonate

    Science.gov (United States)

    Joshi, R. P.; Hareesh, K.; Bankar, A.; Sanjeev, Ganesh; Asokan, K.; Kanjilal, D.; Dahiwale, S. S.; Bhoraskar, V. N.; Dhole, S. D.

    2016-10-01

    Polycarbonate (PC) polymers were investigated before and after high energy heavy ion irradiation for anti-bacterial properties. These PC films were irradiated by Fe heavy ions with two energies, viz, 60 and 120 MeV, at different fluences in the range from 1 × 1011 ions/cm2 to 1 × 1013 ions/cm2. UV-Visible spectroscopic results showed optical band gap decreased with increase in ion fluences due to chain scission mainly at carbonyl group of PC which is also corroborated by Fourier transform infrared spectroscopic results. X-ray diffractogram results showed decrease in crystallinity of PC after irradiation which leads to decrease in molecular weight. This is confirmed by rheological studies and also by differential scanning calorimetric results. The irradiated PC samples showed modification in their surfaces prevents biofilm formation of human pathogen, Salmonella typhi.

  17. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 1 covers papers on the advances of gas phase ion chemistry. The book discusses the advances in flow tubes and the measurement of ion-molecule rate coefficients and product distributions; the ion chemistry of the earth's atmosphere; and the classical ion-molecule collision theory. The text also describes statistical methods in reaction dynamics; the state selection by photoion-photoelectron coincidence; and the effects of temperature and pressure in the kinetics of ion-molecule reactions. The energy distribution in the unimolecular decomposition of ions, as well

  18. Microfabricated ion frequency standard

    Science.gov (United States)

    Schwindt, Peter; Biedermann, Grant; Blain, Matthew G.; Stick, Daniel L.; Serkland, Darwin K.; Olsson, III, Roy H.

    2010-12-28

    A microfabricated ion frequency standard (i.e. an ion clock) is disclosed with a permanently-sealed vacuum package containing a source of ytterbium (Yb) ions and an octupole ion trap. The source of Yb ions is a micro-hotplate which generates Yb atoms which are then ionized by a ultraviolet light-emitting diode or a field-emission electron source. The octupole ion trap, which confines the Yb ions, is formed from suspended electrodes on a number of stacked-up substrates. A microwave source excites a ground-state transition frequency of the Yb ions, with a frequency-doubled vertical-external-cavity laser (VECSEL) then exciting the Yb ions up to an excited state to produce fluorescent light which is used to tune the microwave source to the ground-state transition frequency, with the microwave source providing a precise frequency output for the ion clock.

  19. Ion Coulomb Crystals

    CERN Document Server

    Thompson, Richard C

    2014-01-01

    Ion Coulomb crystals (ICC), formed by atomic ions at low temperatures in radiofrequency and Penning ion traps, are structures that have remarkable properties and many applications. Images of Coulomb crystals are striking and reveal the crystal structure, which arises from a balance between the trapping forces acting on the ions and their mutual Coulomb repulsion. Applications of these structures range from frequency standards and quantum simulation through to measurement of the cross sections of chemical reactions of ions.

  20. Non-equilibrium dynamics contribute to ion selectivity in the KcsA channel.

    Directory of Open Access Journals (Sweden)

    Van Ngo

    Full Text Available The ability of biological ion channels to conduct selected ions across cell membranes is critical for the survival of both animal and bacterial cells. Numerous investigations of ion selectivity have been conducted over more than 50 years, yet the mechanisms whereby the channels select certain ions and reject others are not well understood. Here we report a new application of Jarzynski's Equality to investigate the mechanism of ion selectivity using non-equilibrium molecular dynamics simulations of Na(+ and K(+ ions moving through the KcsA channel. The simulations show that the selectivity filter of KcsA adapts and responds to the presence of the ions with structural rearrangements that are different for Na(+ and K(+. These structural rearrangements facilitate entry of K(+ ions into the selectivity filter and permeation through the channel, and rejection of Na(+ ions. A mechanistic model of ion selectivity by this channel based on the results of the simulations relates the structural rearrangement of the selectivity filter to the differential dehydration of ions and multiple-ion occupancy and describes a mechanism to efficiently select and conduct K(+. Estimates of the K(+/Na(+ selectivity ratio and steady state ion conductance for KcsA from the simulations are in good quantitative agreement with experimental measurements. This model also accurately describes experimental observations of channel block by cytoplasmic Na(+ ions, the "punch through" relief of channel block by cytoplasmic positive voltages, and is consistent with the knock-on mechanism of ion permeation.