WorldWideScience

Sample records for bacterial sulfur globules

  1. X-Ray Absorption Spectroscopy as a Probe of Microbial Sulfur Biochemistry: the Nature of Bacterial Sulfur Globules Revisited ▿

    OpenAIRE

    George, Graham N.; Gnida, Manuel; Dennis A Bazylinski; Prince, Roger C.; Pickering, Ingrid J.

    2008-01-01

    The chemical nature of the sulfur in bacterial sulfur globules has been the subject of controversy for a number of years. Sulfur K-edge X-ray absorption spectroscopy (XAS) is a powerful technique for probing the chemical forms of sulfur in situ, but two groups have used it with very different conclusions. The root of the controversy lies with the different detection strategies used by the two groups, which result in very different spectra. This paper seeks to resolve the controversy. We exper...

  2. Sulfur globule oxidation in green sulfur bacteria is dependent on the dissimilatory sulfite reductase system

    DEFF Research Database (Denmark)

    Holkenbrink, Carina; Ocón Barbas, Santiago; Mellerup, Anders;

    2011-01-01

    Green sulfur bacteria oxidize sulfide and thiosulfate to sulfate with extracellular globules of elemental sulfur as intermediate. Here we investigated which genes are involved in the formation and consumption of these sulfur globules in the green sulfur bacterium Chlorobaculum tepidum. We show that...... sulfur globule oxidation is strictly dependent on the dissimilatory sulfite reductase (DSR) system. Deletion of dsrM/CT2244 or dsrT/CT2245 or the two dsrCABL clusters (CT0851-CT0854, CT2247-2250) abolished sulfur globule oxidation and prevented formation of sulfate from sulfide, whereas deletion of dsr......:quinone oxidoreductases (sqrB/CT0117 and sqrD/CT1087) were deleted, exhibited a decreased sulfide oxidation rate (~50% of wild type), yet formation and consumption of sulfur globules were not affected. The observation that mutants lacking the DSR system maintain efficient growth, suggests that the DSR system is...

  3. In Situ Analysis of Sulfur Species in Sulfur Globules Produced from Thiosulfate by Thermoanaerobacter sulfurigignens and Thermoanaerobacterium thermosulfurigenes▿ †

    OpenAIRE

    Lee, Yong-Jin; Prange, Alexander; Lichtenberg, Henning; Rohde, Manfred; Dashti, Mona; Wiegel, Juergen

    2007-01-01

    The Firmicutes Thermoanaerobacter sulfurigignens and Thermoanaerobacterium thermosulfurigenes convert thiosulfate, forming sulfur globules inside and outside cells. X-ray absorption near-edge structure analysis revealed that the sulfur consisted mainly of sulfur chains with organic end groups similar to sulfur formed in purple sulfur bacteria, suggesting the possibility that the process of sulfur globule formation by bacteria is an ancient feature.

  4. Sub-micrometer-scale mapping of magnetite crystals and sulfur globules in magnetotactic bacteria using confocal Raman micro-spectrometry.

    Science.gov (United States)

    Eder, Stephan H K; Gigler, Alexander M; Hanzlik, Marianne; Winklhofer, Michael

    2014-01-01

    The ferrimagnetic mineral magnetite Fe3O4 is biomineralized by magnetotactic microorganisms and a diverse range of animals. Here we demonstrate that confocal Raman microscopy can be used to visualize chains of magnetite crystals in magnetotactic bacteria, even though magnetite is a poor Raman scatterer and in bacteria occurs in typical grain sizes of only 35-120 nm, well below the diffraction-limited optical resolution. When using long integration times together with low laser power (greigite (cubic Fe3S4; Raman lines of 253 and 351 cm(-1)) is often found in the Deltaproteobacteria class, it is not present in our samples. In intracellular sulfur globules of Candidatus Magnetobacterium bavaricum (Nitrospirae), we identified the sole presence of cyclo-octasulfur (S8: 151, 219, 467 cm(-1)), using green (532 nm), red (638 nm) and near-infrared excitation (785 nm). The Raman-spectra of phosphorous-rich intracellular accumulations point to orthophosphate in magnetic vibrios and to polyphosphate in magnetic cocci. Under green excitation, the cell envelopes are dominated by the resonant Raman lines of the heme cofactor of the b or c-type cytochrome, which can be used as a strong marker for label-free live-cell imaging of bacterial cytoplasmic membranes, as well as an indicator for the redox state. PMID:25233081

  5. Sub-micrometer-scale mapping of magnetite crystals and sulfur globules in magnetotactic bacteria using confocal Raman micro-spectrometry.

    Directory of Open Access Journals (Sweden)

    Stephan H K Eder

    Full Text Available The ferrimagnetic mineral magnetite Fe3O4 is biomineralized by magnetotactic microorganisms and a diverse range of animals. Here we demonstrate that confocal Raman microscopy can be used to visualize chains of magnetite crystals in magnetotactic bacteria, even though magnetite is a poor Raman scatterer and in bacteria occurs in typical grain sizes of only 35-120 nm, well below the diffraction-limited optical resolution. When using long integration times together with low laser power (<0.25 mW to prevent laser induced damage of magnetite, we can identify and map magnetite by its characteristic Raman spectrum (303, 535, 665 cm(-1 against a large autofluorescence background in our natural magnetotactic bacteria samples. While greigite (cubic Fe3S4; Raman lines of 253 and 351 cm(-1 is often found in the Deltaproteobacteria class, it is not present in our samples. In intracellular sulfur globules of Candidatus Magnetobacterium bavaricum (Nitrospirae, we identified the sole presence of cyclo-octasulfur (S8: 151, 219, 467 cm(-1, using green (532 nm, red (638 nm and near-infrared excitation (785 nm. The Raman-spectra of phosphorous-rich intracellular accumulations point to orthophosphate in magnetic vibrios and to polyphosphate in magnetic cocci. Under green excitation, the cell envelopes are dominated by the resonant Raman lines of the heme cofactor of the b or c-type cytochrome, which can be used as a strong marker for label-free live-cell imaging of bacterial cytoplasmic membranes, as well as an indicator for the redox state.

  6. Biologically produced sulfur

    NARCIS (Netherlands)

    Kleinjan, W.E.; Keizer, de A.; Janssen, A.J.H.

    2003-01-01

    Sulfur compound oxidizing bacteria produce sulfur as an intermediate in the oxidation of hydrogen sulfide to sulfate. Sulfur produced by these microorganisms can be stored in sulfur globules, located either inside or outside the cell. Excreted sulfur globules are colloidal particles which are stabil

  7. Isolation and characterization of organic-sulfur degradation bacterial strain

    Institute of Scientific and Technical Information of China (English)

    YANG Yu; DIAO Meng-xue; SHI Wu-yang; LI Li; DAI Qin-yun; QIU Guan-zhou

    2007-01-01

    A bacterial strain that was capable of degrading organic sulfur (dibenzothiophene) was isolated by enrichment techniques from the petroleum-contaminated soil collected from Zhongyuan Oil Field. The strain is named ZYX and is gram-positive.This strain undergoes bacilus-coccus morphological change, and forms yellow-pigment glossy circular colonies with 1.5 mm in diameter on average after 2 d incubation on Luria-Bertani(LB) plates. The full-length of 16S rDNA sequence of strain ZYX was determined and analyzed. Strain ZYX is found most relative with the genus of Arthrobacter. The similarity values between ZYX and Arthrobacter sp. P2 is 99.53%. The main morphological, biochemical and physiological features of strain ZYX accord with those of Arthrobacter. It is found that the optimal initial pH for growth is about 7.0, and the optimal concentration of dibenzothiophene(DBT)for growth is 0.10 g/L. Additionally, the results show that the best carbon source and nitrogen source are glycerol and glutamine,respectively.

  8. Antagonistic Activities of Purple Non-sulfur Bacterial Extracts Against Antibiotic Resistant Vibrio sp.

    OpenAIRE

    Chandrasekaran, R.; Ashok Kumar, G. V.

    2011-01-01

    Solvent extracts of native purple non-sulfur bacterial (PNSB) isolates from the effluents of brackish shrimp culture ponds, near Nagapattinam coast (South India) were evaluated for antibacterial activity by the disc diffusion method. Best results were shown by the chloroform extracts against oxytetracycline resistant Vibrio harveyi and Vibrio fischerii. Among the purple non-sulfur bacterial isolates, Rhodobacter sphaeroides, showed maximum antagonistic activity. The findings suggest that the...

  9. Antagonistic Activities of Purple Non-sulfur Bacterial Extracts Against Antibiotic Resistant Vibrio sp.

    Directory of Open Access Journals (Sweden)

    Chandrasekaran, R.

    2011-01-01

    Full Text Available Solvent extracts of native purple non-sulfur bacterial (PNSB isolates from the effluents of brackish shrimp culture ponds, near Nagapattinam coast (South India were evaluated for antibacterial activity by the disc diffusion method. Best results were shown by the chloroform extracts against oxytetracycline resistant Vibrio harveyi and Vibrio fischerii. Among the purple non-sulfur bacterial isolates, Rhodobacter sphaeroides, showed maximum antagonistic activity. The findings suggest that the antagonistic extracts from Rba. sphaeroides could be used as an effective antibiotic in controlling Vibrio spp., in aquaculture systems.

  10. Novel bacterial sulfur oxygenase reductases from bioreactors treating gold-bearing concentrates

    DEFF Research Database (Denmark)

    Chen, Z-W; Liu, Y-Y; Wu, J-F;

    2007-01-01

    The microbial community and sulfur oxygenase reductases of metagenomic DNA from bioreactors treating gold-bearing concentrates were studied by 16S rRNA library, real-time polymerase chain reaction (RT-PCR), conventional cultivation, and molecular cloning. Results indicated that major bacterial sp...... SOR gene in bioleaching reactors and Acidithiobacillus species....

  11. Effect of sulfur analogue of lysine on bacterial protein biosynthesis

    International Nuclear Information System (INIS)

    S-(beta-Aminoethyl)-L-cysteine, a sulfur analogue of lysine inhibited strongly growth of Escherichia coli A-19, and weakly that of Corynebacterium sp. isolated from soil, but did not inhibit growth of Aerobacter aerogenes. In Corynebacterium sp. the inhibitory effect was markedly enhanced in the presence of L-threonine. The inhibition of growth by S-(beta-aminoethyl)-L-cysteine was rapidly reversed by the addition of L-lysine. S-(beta-Aminoethyl)-L-cysteine inhibited protein synthesis and the activity of lysyl-tRNA synthetase from E. coli and A. aerogenes. All the other lysine analogues tested inhibited the activity of enzyme, but S-(beta-aminoethyl)-L-cysteine derivatives, S-(beta-N-acetyl-aminoethyl)-L-cysteine and S-(beta-aminoethyl)-alpha-N-acetyl-L-cysteine were not effective. (auth.)

  12. Radial systems of dark globules

    International Nuclear Information System (INIS)

    The author gives examples of radial systems consisting of dark globules and ''elephant trunks''. Besides already known systems, which contain hot stars at their center, data are given on three radial systems of a new kind, at the center of which there are stars of spectral types later than B. Data are given on 32 globules of radial systems of the association Cep OB2. On the basis of the observational data, it is concluded that at least some of the isolated Bok globules derive from elephant trunks and dark globules forming radial systems around hot stars. It is also suggested that the two molecular clouds situated near the Rosette nebula and possessing velocities differing by ca 20 km/sec from the velocity of the nebula could have been ejected in opposite directions from the center of the nebula. One of these clouds consists of dark globules forming the radial system of the Rosette nebula

  13. Controls on stable sulfur isotope fractionation during bacterial sulfate reduction in Arctic sediments

    DEFF Research Database (Denmark)

    Bruchert, V.; Knoblauch, C.; Jørgensen, BB

    2001-01-01

    -specific sulfate reduction rates, these greater isotopic differences cannot be accounted for by significantly lower in situ bacterial sulfate reduction rates. Therefore, the remaining isotopic difference between sulfate and sulfide must derive from additional isotope effects that exist in the oxidative part of the...... fractionations varied by less than 5.8 parts per thousand with respect to temperature and sulfate reduction rate, whereas the difference in sulfur isotopic fractionation between bacteria with different carbon oxidation pathways was as large as 17.4 parts per thousand. Incubation of sediment slurries from two...... parts per thousand and 8 parts per thousand above 25 degreesC, respectively. In absence of significant differences in sulfate reduction rates in the high and low temperature range, respectively, we infer that different genera of sulfate-reducing bacteria dominate the sulfate-reducing bacterial community...

  14. Anomalous Diffusion in Fractal Globules

    Science.gov (United States)

    Tamm, M. V.; Nazarov, L. I.; Gavrilov, A. A.; Chertovich, A. V.

    2015-05-01

    The fractal globule state is a popular model for describing chromatin packing in eukaryotic nuclei. Here we provide a scaling theory and dissipative particle dynamics computer simulation for the thermal motion of monomers in the fractal globule state. Simulations starting from different entanglement-free initial states show good convergence which provides evidence supporting the existence of a unique metastable fractal globule state. We show monomer motion in this state to be subdiffusive described by ⟨X2(t )⟩˜tαF with αF close to 0.4. This result is in good agreement with existing experimental data on the chromatin dynamics, which makes an additional argument in support of the fractal globule model of chromatin packing.

  15. Engineering synthetic bacterial consortia for enhanced desulfurization and revalorization of oil sulfur compounds.

    Science.gov (United States)

    Martínez, Igor; Mohamed, Magdy El-Said; Rozas, Daniel; García, José Luis; Díaz, Eduardo

    2016-05-01

    The 4S pathway is the most studied bioprocess for the removal of the recalcitrant sulfur of aromatic heterocycles present in fuels. It consists of three sequential functional units, encoded by the dszABCD genes, through which the model compound dibenzothiophene (DBT) is transformed into the sulfur-free 2-hydroxybiphenyl (2HBP) molecule. In this work, a set of synthetic dsz cassettes were implanted in Pseudomonas putida KT2440, a model bacterial "chassis" for metabolic engineering studies. The complete dszB1A1C1-D1 cassette behaved as an attractive alternative - to the previously constructed recombinant dsz cassettes - for the conversion of DBT into 2HBP. Refactoring the 4S pathway by the use of synthetic dsz modules encoding individual 4S pathway reactions revealed unanticipated traits, e.g., the 4S intermediate 2HBP-sulfinate (HBPS) behaves as an inhibitor of the Dsz monooxygenases, and once secreted from the cells it cannot be further taken up. That issue should be addressed for the rational design of more efficient biocatalysts for DBT bioconversions. In this sense, the construction of synthetic bacterial consortia to compartmentalize the 4S pathway into different cell factories for individual optimization was shown to enhance the conversion of DBT into 2HBP, overcome the inhibition of the Dsz enzymes by the 4S intermediates, and enable efficient production of unattainable high added value intermediates, e.g., HBPS, that are difficult to obtain using the current monocultures. PMID:26802977

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

    DEFF Research Database (Denmark)

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

    1993-01-01

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

  17. Fossil bacterial ecosystem at methane seeps - Origin of organic matter from Be'eri sulfur deposit, Israel

    Science.gov (United States)

    Burhan, R. Y. P.; Trendel, J. M.; Adam, P.; Wehrung, P.; Albrecht, P.; Nissenbaum, A.

    2002-12-01

    The Be'eri sulfur mine (Israel) is a unique deposit mainly composed of sandstone intercalated with biogenic mats and possessing organic matter exceptionally depleted in 13C. Molecular and isotopic studies of free and bound biomarkers were performed to unravel the source of the organic matter co-occurring with sulfur in this deposit and to propose a paleoenvironmental model of bacterial life in a type of extreme environment. They showed that the biomarkers are all extremely 13C-depleted and almost exclusively composed of hopanoids and biphytane derivatives of bacterial origin, notably methanotrophic bacteria and acidophilic archaea. δ 13C values of individual components and of bulk organic carbon are in the -80% to -90% range and are among the lowest values ever measured for hopanoids. Organic matter in the sandstone and the mats differ mainly by the occurrence of 3-methylated hopanoids in the mats, which may reflect either different bacterial populations or different conditions of growth. These data demonstrate that the complete biomass of this deposit primarily derives from methanotrophic hopanoid-synthesizing bacteria consuming methane having seeped toward the surface, and that all other organisms - apparently only archaea and bacteria - must have been thriving on methane-derived carbon (methane, CO 2, biomass of methanotrophic bacteria). Unambiguous evidence for photosynthetic organisms in the environment of deposition could not be found. The Be'eri sulfur deposit is thus a fossil remain of an exclusively bacterial ecosystem fueled by methane as sole carbon source and having developed in an interstitial aqueous medium within the sandstone. Elemental sulfur from the deposit probably originates from the oxidation of hydrogen sulfide seeping along with methane, which could have been oxidized either abiotically or biologically by sulfur-oxidizing Beggiatoa-like bacteria and archaea. Further oxidation of elemental sulfur might explain the high acidity of the deposit

  18. Sub-aqueous sulfur volcanos at Waiotapu, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, S.; Rickard, D. [University of Wales, Cardiff (United Kingdom). Dept. of Earth Sciences; Browne, P.; Simmons, S. [University of Auckland (New Zealand). Geothermal Institute and Geology Dept.; Jull, T. [University of Arizona, Tucson (United States). AMS Facility

    1999-12-01

    Exhumed, sub-aqueous sulfur mounds occur in the Waiotapu geothermal area, New Zealand. The extinct mounds are < 2 m high and composed of small (< 0.5 cm) hollow spheres, and occasional teardrop-shaped globules. They are located within a drained valley that until recently was connected to Lake Whangioterangi. They were formed a maximum of 820 {+-} 80 years BP as a result of the rapid sub-aqueous deposition of sulfur globules, formed when fumarolic gases discharged through molten sulfur pools. Similar globules are now being formed by the discharge of fumarolic gases through a sub-aqueous molten sulfur pool in Lake Whangioterangi. (author)

  19. Oxygen and sulfur isotope systematics of sulfate produced during abiotic and bacterial oxidation of sphalerite and elemental sulfur

    Science.gov (United States)

    Balci, N.; Mayer, B.; Shanks, Wayne C.; Mandernack, K.W.

    2012-01-01

    Studies of metal sulfide oxidation in acid mine drainage (AMD) systems have primarily focused on pyrite oxidation, although acid soluble sulfides (e.g., ZnS) are predominantly responsible for the release of toxic metals. We conducted a series of biological and abiotic laboratory oxidation experiments with pure and Fe-bearing sphalerite (ZnS & Zn 0.88Fe 0.12S), respectively, in order to better understand the effects of sulfide mineralogy and associated biogeochemical controls of oxidation on the resultant ?? 34S and ?? 18O values of the sulfate produced. The minerals were incubated in the presence and absence of Acidithiobacillus ferrooxidans at an initial solution pH of 3 and with water of varying ?? 18O values to determine the relative contributions of H 2O-derived and O 2-derived oxygen in the newly formed sulfate. Experiments were conducted under aerobic and anaerobic conditions using O 2 and Fe(III) aq as the oxidants, respectively. Aerobic incubations with A. ferrooxidans, and S o as the sole energy source were also conducted. The ??34SSO4 values from both the biological and abiotic oxidation of ZnS and ZnS Fe by Fe(III) aq produced sulfur isotope fractionations (??34SSO4-ZnS) of up to -2.6???, suggesting the accumulation of sulfur intermediates during incomplete oxidation of the sulfide. No significant sulfur isotope fractionation was observed from any of the aerobic experiments. Negative sulfur isotope enrichment factors (??34SSO4-ZnS) in AMD systems could reflect anaerobic, rather than aerobic pathways of oxidation. During the biological and abiotic oxidation of ZnS and ZnS Fe by Fe(III) aq all of the sulfate oxygen was derived from water, with measured ?? 18OSO 4-H 2O values of 8.2??0.2??? and 7.5??0.1???, respectively. Also, during the aerobic oxidation of ZnS Fe and S o by A. ferrooxidans, all of the sulfate oxygen was derived from water with similar measured ?? 18OSO 4-H 2O values of 8.1??0.1??? and 8.3??0.3???, respectively. During biological oxidation

  20. Augmenting Sulfur Metabolism and Herbivore Defense in Arabidopsis by Bacterial Volatile Signaling

    Directory of Open Access Journals (Sweden)

    Mina eAziz

    2016-04-01

    Full Text Available Sulfur is an element necessary for the life cycle of higher plants. Its assimilation and reduction into essential biomolecules are pivotal factors determining a plant’s growth and vigor as well as resistance to environmental stress. While certain soil microbes can enhance ion solubility via chelating agents or oxidation, microbial regulation of plant-sulfur assimilation has not been reported. With an increasing understanding that soil microbes can activate growth and stress tolerance in plants via chemical signaling, the question arises as to whether such beneficial bacteria also regulate sulfur assimilation. Here we report a previously unidentified mechanism by which the growth-promoting rhizobacterium Bacillus amyloliquefaciens (GB03 transcriptionally activates genes responsible for sulfur assimilation, increasing sulfur uptake and accumulation in Arabidopsis. Transcripts encoding for sulfur-rich aliphatic and indolic glucosinolates are also GB03 induced. As a result, GB03-exposed plants with elevated glucosinolates exhibit greater protection against the generalist herbivore, Spodoptera exigua (beet armyworm. In contrast, a previously-characterized glucosinolate mutant compromised in the production of both aliphatic and indolic glucosinolates is also compromised in terms of GB03-induced protection against insect herbivory. As with in vitro studies, soil-grown plants show enhanced glucosinolate accumulation and protection against beet armyworm feeding with GB03 exposure. These results demonstrate the potential of microbes to enhance plant sulfur assimilation and emphasize the sophisticated integration of microbial signaling in plant defense.

  1. Augmenting Sulfur Metabolism and Herbivore Defense in Arabidopsis by Bacterial Volatile Signaling

    Science.gov (United States)

    Aziz, Mina; Nadipalli, Ranjith K.; Xie, Xitao; Sun, Yan; Surowiec, Kazimierz; Zhang, Jin-Lin; Paré, Paul W.

    2016-01-01

    Sulfur is an element necessary for the life cycle of higher plants. Its assimilation and reduction into essential biomolecules are pivotal factors determining a plant’s growth and vigor as well as resistance to environmental stress. While certain soil microbes can enhance ion solubility via chelating agents or oxidation, microbial regulation of plant-sulfur assimilation has not been reported. With an increasing understanding that soil microbes can activate growth and stress tolerance in plants via chemical signaling, the question arises as to whether such beneficial bacteria also regulate sulfur assimilation. Here we report a previously unidentified mechanism by which the growth-promoting rhizobacterium Bacillus amyloliquefaciens (GB03) transcriptionally activates genes responsible for sulfur assimilation, increasing sulfur uptake and accumulation in Arabidopsis. Transcripts encoding for sulfur-rich aliphatic and indolic glucosinolates are also GB03 induced. As a result, GB03-exposed plants with elevated glucosinolates exhibit greater protection against the generalist herbivore, Spodoptera exigua (beet armyworm, BAW). In contrast, a previously characterized glucosinolate mutant compromised in the production of both aliphatic and indolic glucosinolates is also compromised in terms of GB03-induced protection against insect herbivory. As with in vitro studies, soil-grown plants show enhanced glucosinolate accumulation and protection against BAW feeding with GB03 exposure. These results demonstrate the potential of microbes to enhance plant sulfur assimilation and emphasize the sophisticated integration of microbial signaling in plant defense. PMID:27092166

  2. Augmenting Sulfur Metabolism and Herbivore Defense in Arabidopsis by Bacterial Volatile Signaling.

    Science.gov (United States)

    Aziz, Mina; Nadipalli, Ranjith K; Xie, Xitao; Sun, Yan; Surowiec, Kazimierz; Zhang, Jin-Lin; Paré, Paul W

    2016-01-01

    Sulfur is an element necessary for the life cycle of higher plants. Its assimilation and reduction into essential biomolecules are pivotal factors determining a plant's growth and vigor as well as resistance to environmental stress. While certain soil microbes can enhance ion solubility via chelating agents or oxidation, microbial regulation of plant-sulfur assimilation has not been reported. With an increasing understanding that soil microbes can activate growth and stress tolerance in plants via chemical signaling, the question arises as to whether such beneficial bacteria also regulate sulfur assimilation. Here we report a previously unidentified mechanism by which the growth-promoting rhizobacterium Bacillus amyloliquefaciens (GB03) transcriptionally activates genes responsible for sulfur assimilation, increasing sulfur uptake and accumulation in Arabidopsis. Transcripts encoding for sulfur-rich aliphatic and indolic glucosinolates are also GB03 induced. As a result, GB03-exposed plants with elevated glucosinolates exhibit greater protection against the generalist herbivore, Spodoptera exigua (beet armyworm, BAW). In contrast, a previously characterized glucosinolate mutant compromised in the production of both aliphatic and indolic glucosinolates is also compromised in terms of GB03-induced protection against insect herbivory. As with in vitro studies, soil-grown plants show enhanced glucosinolate accumulation and protection against BAW feeding with GB03 exposure. These results demonstrate the potential of microbes to enhance plant sulfur assimilation and emphasize the sophisticated integration of microbial signaling in plant defense. PMID:27092166

  3. Magnetic field evolution in Bok globules

    CERN Document Server

    Wolf, S; Henning, T; Wolf, Sebastian; Launhardt, Ralf; Henning, Thomas

    2003-01-01

    Using the Submillimeter Common-User Bolometer Array (SCUBA) at the James Clerk Maxwell Telescope (JCMT), we obtained submillimeter polarization maps of the Bok globules B335, CB230, and CB244 at 850micron. We find strongly aligned polarization vectors in the case of B335 and CB230, indicating a strong coupling of the magnetic field to the dust grains. Based on the distribution of the orientation and strength of the linear polarization we derive the magnetic field strengths in the envelopes of the globules. In agreement with previous submillimeter polarization measurements of Bok globules we find polarization degrees of several percent decreasing towards the centers of the cores. Furthermore, we compare the magnetic field topology with the spatial structure of the globules, in particular with the orientation of the outflows and the orientation of the nonspherical globule cores. In case of the globules B335 and CB230, the outflows are oriented almost perpendicular to the symmetry axis of the globule cores. The ...

  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. Dominance of a clonal green sulfur bacterial population in a stratified lake

    DEFF Research Database (Denmark)

    Gregersen, Lea H; Habicht, Kirsten S; Peduzzi, Sandro;

    2009-01-01

    For many years, the chemocline of the meromictic Lake Cadagno, Switzerland, was dominated by purple sulfur bacteria. However, following a major community shift in recent years, green sulfur bacteria (GSB) have come to dominate. We investigated this community by performing microbial diversity...... population peaked in the chemocline (c. 8 x 10(6) GSB cells mL(-1)) and constituted about 50% of all cells in the anoxic zones of the water column. At least 99.5% of these GSB cells had SSU rRNA, fmoA, and csmCA sequences essentially identical to that of the previously isolated and genome-sequenced GSB...

  6. Liposomes in Double-Emulsion Globules

    OpenAIRE

    Wang, Qing; Tan, Grace; Lawson, Louise B.; John, Vijay T.; Papadopoulos, Kyriakos D.

    2010-01-01

    Tubular liposomes containing a hydrophilic model compound (fluorescein sodium salt, FSS) were entrapped inside the internal aqueous phase (W1) of water-in-oil-in-water (W1/O/W2) double-emulsion globules. Our hypothesis was that the oil membrane of double emulsions can function as a layer of protection to liposomes and their contents and thus better control their release. Liposomes were prepared in bulk, and their release was observed microscopically from individual double-emulsion globules. T...

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

    Science.gov (United States)

    Fowler, T A; Crundwell, F K

    1999-12-01

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

  8. Sulfur isotope fractionation during bacterial sulfate reduction in organic-rich sediments

    DEFF Research Database (Denmark)

    Habicht, K S; Canfield, D E

    1997-01-01

    Isotope fractionation during sulfate reduction by natural populations of sulfate-reducing bacteria was investigated in the cyanobacterial microbial mats of Solar Lake, Sinai and the sediments of Logten Lagoon sulfuretum, Denmark. Fractionation was measured at different sediment depths, sulfate...... natural populations of sulfate reducers and previous measurements from pure cultures. This was somewhat surprising given the extremely high rates of sulfate reduction in the experiments. Our results are explained if we conclude that the fractionation was mainly controlled by the specific rate of sulfate...... reduction (mass cell-1 time-1) and not by the absolute rate (mass volume-1 time-1). Sedimentary sulfides (mainly FeS2) were on average 40% depleted in 34S compared to seawater sulfate. This amount of depletion was more than could be explained by the isotopic fractionations that we measured during bacterial...

  9. Globules of annealed amphiphilic copolymers: Surface structure and interactions

    Science.gov (United States)

    Jarkova, E.; Johner, A.; Maresov, E. A.; Semenov, A. N.

    2006-12-01

    A mean-field theory of globules of random amphiphilic copolymers in selective solvents is developed for the case of an annealed copolymer sequence: each unit can be in one of two states, H (insoluble) or P (soluble or less insoluble). The study is focussed on the regime when H and P units tend to form long blocks, and when P units dominate in the dilute phase, but are rare in the globule core. A first-order coil-to-globule transition is predicted at some T = Tcg. The globule core density at the transition point increases as the affinity of P units to the solvent, tildeɛ, is increased. Two collapse transitions, coil → “loose” globule and “loose” globule → “dense” globule, are predicted if tildeɛ is high enough and P units are marginally soluble or weakly insoluble. H and P concentration profiles near the globule surface are obtained and analyzed in detail. It is shown that the surface excess of P units rises as tildeɛ is increased. The surface tension decreases in parallel. Considering the interaction between close enough surfaces of two globules, we show that they always attract each other at a complete equilibrium. It is pointed out, however, that such equilibrium may be difficult to reach, so that partially equilibrium structures (defined by the condition that a chain forming one globule does not penetrate into the core of the other globule) are relevant. It is shown that at such partial equilibrium the interaction is repulsive, so the globules may be stabilized from aggregation. The strongest repulsion is predicted at the coil-to-globule transition point Tcg: the repulsion force decreases with the distance between the surfaces according to a power law. In the general case (apart from Tcg) the force vs. distance decay becomes exponential; the decay length ξ diverges as T → Tcg. The developed theory explains certain anomalous properties observed for globules of amphiphilic homopolymers.

  10. Oxygen and sulfur isotope systematics of sulfate produced by bacterial and abiotic oxidation of pyrite

    Science.gov (United States)

    Balci, N.; Shanks, Wayne C., III; Mayer, B.; Mandernack, K.W.

    2007-01-01

    To better understand reaction pathways of pyrite oxidation and biogeochemical controls on ??18O and ??34S values of the generated sulfate in acid mine drainage (AMD) and other natural environments, we conducted a series of pyrite oxidation experiments in the laboratory. Our biological and abiotic experiments were conducted under aerobic conditions by using O2 as an oxidizing agent and under anaerobic conditions by using dissolved Fe(III)aq as an oxidant with varying ??18OH2O values in the presence and absence of Acidithiobacillus ferrooxidans. In addition, aerobic biological experiments were designed as short- and long-term experiments where the final pH was controlled at ???2.7 and 2.2, respectively. Due to the slower kinetics of abiotic sulfide oxidation, the aerobic abiotic experiments were only conducted as long term with a final pH of ???2.7. The ??34SSO4 values from both the biological and abiotic anaerobic experiments indicated a small but significant sulfur isotope fractionation (???-0.7???) in contrast to no significant fractionation observed from any of the aerobic experiments. Relative percentages of the incorporation of water-derived oxygen and dissolved oxygen (O2) to sulfate were estimated, in addition to the oxygen isotope fractionation between sulfate and water, and dissolved oxygen. As expected, during the biological and abiotic anaerobic experiments all of the sulfate oxygen was derived from water. The percentage incorporation of water-derived oxygen into sulfate during the oxidation experiments by O2 varied with longer incubation and lower pH, but not due to the presence or absence of bacteria. These percentages were estimated as 85%, 92% and 87% from the short-term biological, long-term biological and abiotic control experiments, respectively. An oxygen isotope fractionation effect between sulfate and water (??18 OSO4 s(-) H2 O) of ???3.5??? was determined for the anaerobic (biological and abiotic) experiments. This measured ??18 OSO42 - s(-) H2

  11. Formation and Evolution of Cometary Globules

    Science.gov (United States)

    Lefloch, Bertrand

    1994-06-01

    We have conducted a detailed study both numerical and analytical of Cometary Globules (CGs), related to their possible mechanism of formation. CGs are small dense clouds commonly found in the vicinity of O--B stars in HII regions; they consist of a dense head, surrounded by a bright rim, prolonged by a diffuse tail. Recent surveys have shown that CGs are active sites of star formation. One of the models advanced to explain the formation and the evolution of CGs is the ``Radiation-Driven Implosion''(RDI): the UV flux of the O--B association ionizes the external layers of the cloud. The ionised gas expands freely into the interstellar medium while an ionization front preceded by a shock propagates into the cloud. We have built a 2-D radiative hydrodynamical code based on the piece-wise linear method. The equations of radiative transfer are solved using the "on-the-spot" approximation. The equation of state P = P(ρ,x), where x is the ionised fraction per atom, couples the equations of hydrodynamics and radiation. Gravity is neglected. We have shown that photo-ionisation alone can account for the formation and evolution of CGs. For physical parameters typical of H II regions, RDI is a two-stage process: a brief collapse phase (~105 yrs, 10% of the cloud life) followed by a transient phase during which the cloud undergoes a series of radial expansions and re-compressions, leading to the commonly observed cometary phase. The collapse phase is characterised by a double kinematic emission component, the second component being associated with shocked gas. In the cometary phase, the globule is in a quasi-hydrostatic equilibrium and has no remarkable spectroscopic signature. This phase lasts a few 105 to 106 yrs. The results of numerical simulations were confirmed by a simple analytic model and extended to the case of a non-thermal support. It appears that small- and large-scale instabilities, Rayleigh-Taylor like, similar to the surface corrugations observed in CGs of the

  12. Origin and structure of isolated dark globules

    International Nuclear Information System (INIS)

    High resolution carbon monoxide observations of over a dozen isolated dark globules indicate that a power-law correlation exists between the internal velocity dispersion and cloud size. The power-law relation implies the presence of supersonic turbulence that is similar to that found in other diffuse clouds and molecular cloud complexes. Thus the observed motions in globules may be all part of a common hierarchy of interstellar tubular motions. Most of the gobules are found to be gravitationally bound and in virial equilibrium. The average gas density seems to decrease with increasing cloud size, suggesting that gravitational contraction may account for the difference in gas density. The effects of gravitational contraction, which tends to increase the central gas density, coupled with the more rapid dissipation of turbulent motions in high density regions may account for the observed difference in velocity dispersion in different parts of a cloud. The results are consistent with the scenario that isolated dark globules represent condensed fragments from nearby filamentary cloud complexes, the formation of which depends strongly on the properties of interstellar turbulence

  13. Cytoplasmic Sulfurtransferases in the Purple Sulfur Bacterium Allochromatium vinosum: Evidence for Sulfur Transfer from DsrEFH to DsrC

    OpenAIRE

    Yvonne Stockdreher; Venceslau, Sofia S.; Michaele Josten; Hans-Georg Sahl; Pereira, Inês A. C.; Christiane Dahl

    2012-01-01

    While the importance of sulfur transfer reactions is well established for a number of biosynthetic pathways, evidence has only started to emerge that sulfurtransferases may also be major players in sulfur-based microbial energy metabolism. Among the first organisms studied in this regard is the phototrophic purple sulfur bacterium Allochromatium vinosum. During the oxidation of reduced sulfur species to sulfate this Gammaproteobacterium accumulates sulfur globules. Low molecular weight organi...

  14. Hier ist wahrhaftig ein Loch im Himmel - The NGC 1999 dark globule is not a globule

    CERN Document Server

    Stanke, T; Tobin, J J; Ali, B; Megeath, S T; Krause, O; Linz, H; Allen, L; Bergin, E; Calvet, N; Di Francesco, J; Fischer, W J; Furlan, E; Hartmann, L; Henning, T; Manoj, P; Maret, S; Muzerolle, J; Myers, P C; Neufeld, D; Osorio, M; Pontoppidan, K; Poteet, C A; Watson, D M; Wilson, T

    2010-01-01

    The NGC 1999 reflection nebula features a dark patch with a size of ~10,000 AU, which has been interpreted as a small, dense foreground globule and possible site of imminent star formation. We present Herschel PACS far-infrared 70 and 160mum maps, which reveal a flux deficit at the location of the globule. We estimate the globule mass needed to produce such an absorption feature to be a few tenths to a few Msun. Inspired by this Herschel observation, we obtained APEX LABOCA and SABOCA submillimeter continuum maps, and Magellan PANIC near-infrared images of the region. We do not detect a submillimer source at the location of the Herschel flux decrement; furthermore our observations place an upper limit on the mass of the globule of ~2.4x10^-2 Msun. Indeed, the submillimeter maps appear to show a flux depression as well. Furthermore, the near-infrared images detect faint background stars that are less affected by extinction inside the dark patch than in its surroundings. We suggest that the dark patch is in fac...

  15. Interactions between milk fat globules and green tea catechins.

    Science.gov (United States)

    Rashidinejad, Ali; Birch, E John; Everett, David W

    2016-05-15

    The determination of putative chemical interactions between the milk fat globule membrane and green tea catechins provided useful information about the role of milk fat globules (MFGs) in high-fat dairy systems, such as cheese, and containing bioactive compounds, such as tea catechins. Catechins from green tea (125-1000ppm), including (+)-catechin, (-)-epigallocatechin gallate, and green tea extract were added to washed MFGs to examine possible interactions. The addition of catechins gave a significant change in the size and ζ-potential of MFGs. The recovery of different catechins from the milk fat globule suspensions was found to vary, suggesting selective association with the milk fat globule membranes. The interactions were further investigated using transmission electron microscopy and Fourier transform infra-red spectroscopy. It is suggested that catechins are localised in association with milk fat globule membrane domains as they contain both hydrophobic and hydrophilic moieties with potential points of molecular interaction. PMID:26775981

  16. Gypsum amendment to rice paddy soil stimulated bacteria involved in sulfur cycling but largely preserved the phylogenetic composition of the total bacterial community.

    Science.gov (United States)

    Wörner, Susanne; Zecchin, Sarah; Dan, Jianguo; Todorova, Nadezhda Hristova; Loy, Alexander; Conrad, Ralf; Pester, Michael

    2016-06-01

    Rice paddies are indispensable for human food supply but emit large amounts of the greenhouse gas methane. Sulfur cycling occurs at high rates in these water-submerged soils and controls methane production, an effect that is increased by sulfate-containing fertilizers or soil amendments. We grew rice plants until their late vegetative phase with and without gypsum (CaSO4 ·2H2 O) amendment and identified responsive bacteria by 16S rRNA gene amplicon sequencing. Gypsum amendment decreased methane emissions by up to 99% but had no major impact on the general phylogenetic composition of the bacterial community. It rather selectively stimulated or repressed a small number of 129 and 27 species-level operational taxonomic units (OTUs) (out of 1883-2287 observed) in the rhizosphere and bulk soil, respectively. Gypsum-stimulated OTUs were affiliated with several potential sulfate-reducing (Syntrophobacter, Desulfovibrio, unclassified Desulfobulbaceae, unclassified Desulfobacteraceae) and sulfur-oxidizing taxa (Thiobacillus, unclassified Rhodocyclaceae), while gypsum-repressed OTUs were dominated by aerobic methanotrophs (Methylococcaceae). Abundance correlation networks suggested that two abundant (>1%) OTUs (Desulfobulbaceae, Rhodocyclaceae) were central to the reductive and oxidative parts of the sulfur cycle. PMID:27085098

  17. Utilization of 'elemental' sulfur by different phototrophic sulfur bacteria (Chromatiaceae, Ectothiorhodospiraceae): A sulfur K-edge XANES spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Franz, B; Prange, A [Niederrhein University of Applied Sciences, Competence Center for Microbiology and Biotechnology (CCMB), Rheydter Strasse 277, 41065 Moenchengladbach (Germany); Lichtenberg, H; Hormes, J [Louisiana State University, Center for Advanced Microstructures and Devices (CAMD), 6980 Jefferson Highway, Baton Rouge, LA 70806 (United States); Dahl, C, E-mail: A.Prange@gmx.d [University of Bonn, Institute for Microbiology and Biotechnology, Meckenheimer Allee 168, 53115 Bonn (Germany)

    2009-11-15

    Phototrophic sulfur bacteria are generally able to use elemental sulfur as an electron donor for anoxygenic photosynthesis. Elemental sulfur is mainly a mixture of cyclo-octasulfur and polymeric sulfur. The purple sulfur bacterium Allochromatium vinosum strongly prefers the polymeric sulfur fraction showing that sulfur speciation has a strong influence on availability of elemental sulfur. X-ray absorption near edge structure (XANES) spectroscopy was used to investigate whether polymeric sulfur is also the preferred sulfur species in other purple sulfur bacteria belonging to the families Chromatiaceae and Ecothiorodospiraceae. The cultures were fed with 50 mM of elemental sulfur consisting of 68% polymeric sulfur and 30% cyclo-octasulfur. In all cultures, elemental sulfur was converted into intra- or extracellular sulfur globules, respectively, and further oxidized to sulfate. Sulfate concentrations were determined by HPLC and turbidometric assays, respectively. However, the added elemental sulfur was only partly used by the bacteria, one part of the 'elemental sulfur' remained in the cultures and was not taken up. XANES spectroscopy revealed that only the polymeric sulfur fraction was taken up by all cultures investigated. This strongly indicates that polymeric 'chain-like' sulfur is the form preferably used by phototrophic sulfur bacteria.

  18. Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria

    DEFF Research Database (Denmark)

    Gregersen, Lea Haarup; Bryant, Donald A.; Frigaard, Niels-Ulrik

    2011-01-01

    Green sulfur bacteria (GSB) constitute a closely related group of photoautotrophic and thiotrophic bacteria with limited phenotypic variation. They typically oxidize sulfide and thiosulfate to sulfate with sulfur globules as an intermediate. Based on genome sequence information from 15 strains, the...... distribution and phylogeny of enzymes involved in their oxidative sulfur metabolism was investigated. At least one homolog of sulfide:quinone oxidoreductase (SQR) is present in all strains. In all sulfur-oxidizing GSB strains except the earliest diverging Chloroherpeton thalassium, the sulfide oxidation...

  19. Fractal Globules: A New Approach to Artificial Molecular Machines

    Science.gov (United States)

    Avetisov, Vladik A.; Ivanov, Viktor A.; Meshkov, Dmitry A.; Nechaev, Sergei K.

    2014-01-01

    The over-damped relaxation of elastic networks constructed by contact maps of hierarchically folded fractal (crumpled) polymer globules was investigated in detail. It was found that the relaxation dynamics of an anisotropic fractal globule is very similar to the behavior of biological molecular machines like motor proteins. When it is perturbed, the system quickly relaxes to a low-dimensional manifold, M, with a large basin of attraction and then slowly approaches equilibrium, not escaping M. Taking these properties into account, it is suggested that fractal globules, even those made by synthetic polymers, are artificial molecular machines that can transform perturbations into directed quasimechanical motion along a defined path. PMID:25418305

  20. Magnetic field dispersion in the neighbourhood of Bok Globules

    Science.gov (United States)

    Rodrigues, C. V.; Magalhães, V. de S.; Vilas-Boas, J. W.; Racca, G.; Pereyra, A.

    2014-08-01

    We performed an observational study of the relation between the interstellar magnetic field alignment and star formation in twenty (20) sky regions containing Bok Globules. The presence of young stellar objects in the globules is verified by a search of infrared sources with spectral energy distribution compatible with a pre main-sequence star. The interstellar magnetic field direction is mapped using optical polarimetry. These maps are used to estimate the dispersion of the interstellar magnetic field direction in each region from a Gaussian fit, σ B . In addition to the Gaussian dispersion, we propose a new parameter, η, to measure the magnetic field alignment that does not rely on any function fitting. Statistical tests show that the dispersion of the magnetic field direction is different in star forming globules relative to quiescent globules. Specifically, the less organised magnetic fields occur in regions having young stellar objects.

  1. Magnetic field dispersion in the neighbourhood of Bok Globules

    CERN Document Server

    Rodrigues, C V; Vilas-Boas, J W; Racca, G; Pereyra, A

    2013-01-01

    We performed an observational study of the relation between the interstellar magnetic field alignment and star formation in twenty (20) sky regions containing Bok Globules. The presence of young stellar objects in the globules is verified by a search of infrared sources with spectral energy distribution compatible with a pre main-sequence star. The interstellar magnetic field direction is mapped using optical polarimetry. These maps are used to estimate the dispersion of the interstellar magnetic field direction in each region from a Gaussian fit, sigma_B. In addition to the Gaussian dispersion, we propose a new parameter, eta, to measure the magnetic field alignment that does not rely on any function fitting. Statistical tests show that the dispersion of the magnetic field direction is different in star forming globules relative to quiescent globules. Specifically, the less organised magnetic fields occur in regions having young stellar objects.

  2. Electron Microscopic Localization of Cholesterol in Bovine Milk Fat Globules

    OpenAIRE

    Martin, Robert W.

    1989-01-01

    An electron microscopic method designed for the detection of cholesterol in milk fat was evaluated for reliability. This method is based on the incubation of cream from raw milk with fillipin (a polyene antibiotic) which has a specific affinity for cholesterol followed by freeze fracturing and electron microscopic examination of fat globules. Cholesterol was localized within the membrane and the triglyceride core of milk fat globules. Cholesterol was highly organized within membrane portio...

  3. Sulfur Mustard

    Science.gov (United States)

    ... Matters What's New A - Z Index Facts About Sulfur Mustard What sulfur mustard is Sulfur mustard is a type of ... it is in liquid or solid form. Where sulfur mustard is found and how it is used ...

  4. On the origins of polarization holes in Bok globules

    CERN Document Server

    Brauer, R; Reissl, S

    2016-01-01

    Context. Polarimetric observations of Bok globules frequently show a decrease in the degree of polarization towards their central dense regions (polarization holes). This behaviour is usually explained with increased disalignment owing to high density and temperature, or insufficient angular resolution of a possibly complex magnetic field structure. Aims. We investigate whether a significant decrease in polarized emission of dense regions in Bok globules is possible under certain physical conditions. For instance, we evaluate the impact of optical depth effects and various properties of the dust phase. Methods. We use radiative transfer modelling to calculate the temperature structure of an analytical Bok globule model and simulate the polarized thermal emission of elongated dust grains. For the alignment of the dust grains, we consider a magnetic field and include radiative torque and internal alignment. Results. Besides the usual explanations, selected conditions of the temperature and density distribution,...

  5. Fat globule size distribution in milk of a German buffalo herd

    OpenAIRE

    Thiele, M; Swalve, H. H.; R. Schmidt; R. Schafberg

    2010-01-01

    The volume-surface average diameter of fat globules are larger in buffalo milk than in cow milk and the volume frequency distribution in buffalo milk is more balanced. The globule size was affected by animal, stage of lactation, and test day. An interesting contrast compared to cow milk is the negative correlation between diurnal fat yield and globule size.

  6. Fat globule size distribution in milk of a German buffalo herd

    Directory of Open Access Journals (Sweden)

    M. Thiele

    2010-02-01

    Full Text Available The volume-surface average diameter of fat globules are larger in buffalo milk than in cow milk and the volume frequency distribution in buffalo milk is more balanced. The globule size was affected by animal, stage of lactation, and test day. An interesting contrast compared to cow milk is the negative correlation between diurnal fat yield and globule size.

  7. ISO Observations of Starless Bok Globules: Usually No Embedded Stars

    Science.gov (United States)

    Clemens, D.; Byrne, A.; Yun, J.; Kane, B.

    1996-01-01

    We have used ISOCAM to search the cores of a sample of small Bok globules previously classified to be mostly starless based on analysis of IRAS data. The ISO observations at 6.75microns (LW2 filter) and 14.5microns (LW3 filter) were sufficiently deep to enable detection of any low-mass hydrogen burning star or young stellar object (YSO) embedded in these globules. Of the 20 Bok globules observed by ISOCAM to date, we have reduced the data for 14. Of these, 13 show no evidence for faint red (S(sub v)(LW3) greater than S(sub v)(LW2)) stars missed by IRAS. One (CB68) does show the first mid-infrared detection of the very cool IRAS source toward this cloud, and may be a Class I or 0 YSO. We conclude, based on these new ISO observations, that Bok globules which have no IRAS sources are in general bona fide starless molecular clouds.

  8. The Bok Globule BHR 160: structure and star formation

    CERN Document Server

    Haikala, Lauri K

    2016-01-01

    BHR 160 is a virtually unstudied cometary globule within the Sco OB4 association in Scorpius at a distance of 1600pc. It is part of a system of cometary clouds which face the luminous O star HD155806. BHR 160 is special because it has an intense bright rim. We attempt to derive physical parameters for BHR 160 and to understand its structure and the origin of its peculiar bright rim. BHR 160 was mapped in the $^{12}$CO, $^{13}$CO and C$^{18}$O (2-1) and (1-0) and CS (3-2) and (2-1) lines. These data, augmented with stellar photometry derived from the ESO VVV survey, were used to derive the mass and distribution of molecular material in BHR 160 and its surroundings. Archival mid-infrared data from the WISE satellite was used to find IR excess stars in the globule and its neighbourhood. An elongated 1' by 0.6' core lies adjacent to the globule bright rim. $^{12}$CO emission covers the whole globule, but the $^{13}$CO, C$^{18}$CO and CS emission is more concentrated to the core. The $^{12}$CO line profiles indica...

  9. Molecular Composition of Carbonaceous Globules in the Bells (CM2) Chondrite

    Science.gov (United States)

    Clemett, S. J.; Nakamura-Messenger, K.; Thomas-Keprta, K. L.; Robinson, G.-A.; Mckay, D. S.

    2009-01-01

    Some meteorites and IDPs contain micron-size carbonaceous globules that are associated with significant H and/or N isotopic anomalies. This has been interpreted as indicating that such globules may contain at least partial preserved organic species formed in the outer reaches of the proto-solar disk or the presolar cold molecular cloud. Owing to their small sizes, relatively little is known about their chemical compositions. Here we present in situ measurements of aromatic molecular species in organic globules from the Bells (CM2) chondrite by microprobe two-step laser mass spectrometry. This meteorite was chosen for study because we have previously found this meteorite to contain high abundances of globules that often occur in clusters. The Bells (CM2) globules are also noteworthy for having particularly high enrichments in H-2. and N-15. In this study, we identified individual globules and clusters of globules using native UV fluorescence.

  10. Milk fat globule membrane and buttermilks: from composition to valorization

    Directory of Open Access Journals (Sweden)

    Vanderghem, C.

    2010-01-01

    Full Text Available Buttermilk, the by-product from butter manufacture, is low cost and available in large quantities but has been considered for many years as invaluable. However, over the last two decades it has gained considerable attention due to its specific composition in proteins and polar lipids from the milk fat globule membrane (MFGM. The aim of this review is to take stock of current buttermilk knowledge. Firstly, the milk fat globule membrane composition and structure are described. Secondly, buttermilk and its associated products are defined according to the milk fat making process. Structure and mean composition of these products are summarized from recent dairy research data and related to technological properties, especially the emulsifying properties provided by MFGM components. Finally, new applications are presented, leading to promising valorizations of buttermilk and its derivate products.

  11. Anticariogenic and phytochemical evaluation of Eucalyptus globules Labill.

    OpenAIRE

    Kalpesh B Ishnava; Chauhan, Jenabhai B.; Barad, Mahesh B.

    2012-01-01

    In the present study, in vitro anticariogenic potential of ethyl acetate, hexane and methanol and aqueous extracts of plant leaves of Eucalyptus globules Labill. were evaluated by using four cariogenic bacteria, Lactobacillus acidophilus, Lactobacillus casei, Staphylococcus aureus and Streptococcus mutans. Agar well diffusion method and minimum inhibitory concentration (MIC) were used for this purpose. The ethyl acetate extracted fraction of plant leaves showed good inhibitory effects against...

  12. PIG (partially ionized globule) anatomy - Density and temperature structure of the bright-rimmed globule IC 1396E

    Science.gov (United States)

    Serabyn, E.; Guesten, R.; Mundy, L.

    1993-01-01

    The density and temperature structure of the bright-rimmed cometary globule IC 1396E is estimated, and the possibility that recent internal star formation was triggered by the ionization front in its southern surface is assessed. On the basis of NH3 data, gas temperatures in the globule are found to increase outward from the center, from a minimum of 17 K in its tail to a maximum of 26 K on the surface most directly facing the stars ionizing IC 1396. On the basis of a microturbulent radiative transfer code to model the radial dependence of the CS line intensities, and also the intensities of the optically thin 2-1 and 5-4 lines toward the cloud center, a radial density dependence of r exp -1.55 to r exp -1.75 is found.

  13. The formation of elephant-trunk globules in the Rosette nebula: CO observations

    International Nuclear Information System (INIS)

    The prominent elephant-trunk globules in the northwest quadrant of the Rosette nebula have been observed in the microwave lines of CO and 13CO (J=1→0). The CO emission closely follows the optical outline of the obscuring material and leaves little doubt that the emission is associated with the globules. The physical characteristics derived are typical of those observed in other dust globules which are not necessarily associated with H II regions

  14. In situ observation of D-rich carbonaceous globules embedded in NWA 801 CR2 chondrite

    Science.gov (United States)

    Hashiguchi, Minako; Kobayashi, Sachio; Yurimoto, Hisayoshi

    2013-12-01

    Eighty-five D-rich carbonaceous particles were identified in the matrix of the NWA 801 CR2 chondrite using isotope microscopy. The occurrence of 67 D-rich carbonaceous particles was characterized using secondary electron microscopy combined with X-ray elemental mapping. The close association of H and C, and D-enrichment suggests that the D-rich carbonaceous particles correspond to organic matter. The D-rich organic particles were scattered ubiquitously throughout the matrix at a concentration of approximately 660 ppm. The morphology of the D-rich carbonaceous particles is globular up to about 1 μm in diameter and is classified into four types: ring globules, round globules, irregular-shaped globules, and globule aggregates. The ring globules are ring-shaped organic matter containing silicate and/or oxide, with or without a void in the center. This is the first report of silicate and oxide grains surrounded by D-rich organic matter. The globule aggregates are composed of several D-rich organic globules mixed with silicates. Morphology of ring globules is very similar to core-mantle grain produced in the molecular cloud or in the outer solar nebula inferring by astronomy, suggesting that the organic globules have formed by UV photolysis in the ice mantle. Silicates or oxides attached to D-rich organic globules are the first observation among chondrites so far and may be unique nature of CR2 chondrites. The hydrogen isotopic compositions of the ring globules, round globules, irregular-shaped globules, and globule aggregates are δD = 3000-4800, 2900-8100, 2700-11,000, and 2500-11,000‰, respectively. Variations of D/H ratio of these organic globules seemed to be attributed to variations of D/H ratio of the organic radicals or differences of content of the D-rich organic radicals. There are no significant differences in the hydrogen isotopic compositions among the four types of D-rich carbonaceous matter. The D-enrichments suggest that these organic globules have

  15. Nitrogen, carbon, and sulfur metabolism in natural Thioploca samples

    DEFF Research Database (Denmark)

    Otte, S.; Kuenen, JG; Nielsen, LP;

    1999-01-01

    Filamentous sulfur bacteria of the genus Thioploca occur as dense mats on the continental shelf off the coast of Chile and Peru. Since little is known about their nitrogen, sulfur, and carbon metabolism, this study was undertaken to investigate their (eco)physiology. Thioploca is able to store...... internally high concentrations of sulfur globules and nitrate. It has been previously hypothesized that these large vacuolated bacteria can oxidize sulfide by reducing their internally stored nitrate. We examined this nitrate reduction by incubation experiments of washed Thioploca sheaths,vith trichomes in......) mg of protein(-1). The ammonium and sulfate production rates were not influenced by the addition of sulfide, suggesting that sulfide is first oxidized to elemental sulfur, and in a second independent step elemental sulfur is oxidized to sulfate. The average sulfide oxidation rate measured was 5 nmol...

  16. Star formation in the Cometary Globule Ori I-2

    CERN Document Server

    Mookerjea, B

    2009-01-01

    We investigate the young stellar population in and near the cometary globule Ori,I-2. The analysis is based on deep Nordic Optical Telescope R-band and H-alpha images, JCMT SCUBA 450 and 850 micron images combined with near-infrared 2MASS photometry and mid-infrared archival Spitzer images obtained with the IRAC (3.6, 4.5, 5.8 and 8 micron), and MIPS (24 and 70 micron) instruments. We identify a total of 125 sources within the 5'x5' region imaged by IRAC. Of these sources 87 are detected in the R-band image and 51 are detected in the 2MASS survey. The detailed physical properties of the sources are explored using a combination of near/mid-infrared color-color diagrams, greybody fitting of SEDs and an online SED fitting tool that uses a library of 2D radiation transfer based accretion models of young stellar objects with disks. Ori I-2 shows clear evidence of triggered star formation with four young low luminosity pre-main sequence stars embedded in the globule. At least two, possibly as many as four, addition...

  17. A Two Micron All Sky Survey Analysis of the Stability of Southern Bok Globules

    Science.gov (United States)

    Racca, Germán A.; Vilas-Boas, José W. S.; de la Reza, Ramiro

    2009-10-01

    We used near-infrared Two Micron All Sky Survey data to construct visual extinction maps of a sample of Southern Bok globules utilizing the NICE method. We derived radial extinction profiles of dense cores identified in the globules and analyzed their stability against gravitational collapse with isothermal Bonnor-Ebert spheres. The frequency distribution of the stability parameter (ξmax) of these cores shows that a large number of them are located in stable states, followed by an abrupt decrease of cores in unstable states. This decrease is steeper for globules with associated IRAS point sources than for starless globules. Moreover, globules in stable states have a Bonnor-Ebert temperature of T = 15 ± 6 K, while the group of critical plus unstable globules has a different temperature of T = 10 ± 3 K. Distances were estimated to all the globules studied in this work and the spectral class of the IRAS sources was calculated. No variations were found in the stability parameters of the cores and the spectral class of their associated IRAS sources. On the basis of 13CO J = 1 - 0 molecular line observations, we identified and modeled a blue-asymmetric line profile toward a globule of the sample, obtaining an upper limit infall speed of 0.25 km s-1. Based on a Ph.D. thesis made at Observatório Nacional, Rio de Janeiro, Brazil.

  18. Isolation and Characterization of Carotenoid-rich Lipid Globules from Peridinium foliaceum.

    Science.gov (United States)

    Withers, N W; Haxo, F T

    1978-07-01

    Carotenoid-rich oil globules were isolated from the cytoplasm of the binucleate dinoflagellate, Peridinium foliaceum. These orange globules were collected from ruptured cells by ultracentrifugation on a sucrose density gradient, and checked for purity by electron microscopy. The osmiophilic globules were assayed for lipid (including pigment) and protein content. The lipid to protein ratio was 1.39:1, with a calculated density of the globules of 1.05 grams per cubic centimeter. The lipids were composed of hydrocarbon, wax ester (phytyl ester), triglyceride, and polar (no phospholipid) fractions. The biochemical composition indicated that the globules function as a reservoir of energy-rich components in the cell. Microspectrophotometric observations were consistent with pigment analyses which demonstrated that the globules were carotenoid-rich. In addition to beta-carotene, gamma-carotene, and canthaxanthin, the carotenogenic precursors: phytoene, phytofluence, zeta-carotene and beta-zeacarotene were isolated from the globules. Corrected fluorescence maxima of phytoene and phytofluene in hexane were recorded at 340 and 490 nanometers, respectively. Carotenes constituted 3.3% of the total oil globule lipid. The possibility of an extraplastidic carotenogenic enzyme system in P. foliaceum is discussed. PMID:16660464

  19. Influence of shear on globule formation in dilute solutions of flexible polymers

    Science.gov (United States)

    Radhakrishnan, Rangarajan; Underhill, Patrick T.

    2015-04-01

    Polyelectrolytes, polymers in poor solvents, polymers mixed with particles, and other systems with attractions and repulsions show formation of globules/structures in equilibrium or in flow. To study the flow behavior of such systems, we developed a simple coarse-grained model with short ranged attractions and repulsions. Polymers are represented as charged bead-spring chains and they interact with oppositely charged colloids. Neglecting hydrodynamic interactions, we study the formation of compact polymer structures called globules. Under certain conditions, increase in shear rate decreases the mean first passage time to form a globule. At other conditions, shear flow causes the globules to breakup, similar to the globule-stretch transition of polymers in poor solvents.

  20. Star Formation in the Cometary Globule Ori I-2

    Science.gov (United States)

    Mookerjea, Bhaswati; Sandell, Göran

    2009-11-01

    We investigate the young stellar population in and near the cometary globule Ori I-2. The analysis is based on deep Nordic Optical Telescope R-band and Hα images, JCMT SCUBA 450 and 850 μm images combined with near-infrared Two Micron All Sky Survey (2MASS) photometry and mid-infrared archival Spitzer images obtained with the Infrared Array Camera (IRAC; 3.6, 4.5, 5.8, and 8 μm), and MIPS (24 and 70 μm) instruments. We identify a total of 125 sources within the 5'×5' region imaged by the IRAC. Of these sources, 87 are detected in the R-band image and 51 are detected in the 2MASS. The detailed physical properties of the sources are explored using a combination of near/mid-infrared color-color diagrams, graybody fitting of spectral energy distributions (SEDs) and an online SED fitting tool that uses a library of two-dimensional radiation transfer based accretion models of young stellar objects with disks. Ori I-2 shows clear evidence of triggered star formation with four young low-luminosity pre-main-sequence (PMS) stars embedded in the globule. At least two, possibly as many as four, additional low-mass PMS objects were discovered in the field which are probably part of the young σ Orionis cluster. Among the PMS stars which have formed in the globule, MIR-54 is a young, deeply embedded Class 0/I object; MIR-51 and 52 are young Class II sources, while MIR-89 is a more evolved, heavily extincted Class II object with its apparent colors mimicking a Class 0/I object. The Class 0/I object MIR-54 coincides with a previously known IRAS source and is a strong submillimeter source. It is most likely the source for the molecular outflow and the large parsec-scale Herbig-Haro (HH) flow. However, the nearby Class II source, MIR-52, which is strong a Hα emission line star, also appears to drive an outflow approximately aligned with the outflow from MIR-54, and because of the proximity of the two outflows, either star could contribute. MIR-89 appears to excite a low

  1. The Environment and Magnetic Field of Cometary Globule CG30

    Science.gov (United States)

    Hickel, Gabriel R.; Vilas-Boas, José W. S.

    2005-09-01

    In this work, we combine observations of optical linear polarization (R band), IRAS far-infrared images and radio molecular lines to investigate the cometary globule CG30 (at IRAS Vela Shell). CG30 shows Herbig-Haro objects, molecular outflows, hosts a very young binary star and has a star formation efficiency of about 6% to 17%. Its magnetic field is important to support the CG structure and shows evidence of torsion and compression of the field lines. The quadrupolar outflow of the binary star affects the temperature of the molecular gas, and changes the degree of polarization of the dust grains in the environment of CG30. This work is based on observations collected at LNA/CNPq, Brazil and SEST/ESO, Chile.

  2. THE CHEMICAL AGE OF THE BOK GLOBULE CB238

    International Nuclear Information System (INIS)

    The Bok globule CB238 has been investigated in 13CO (220.4 GHz), C18O (109.7 GHz), CS (97.9 and 146.7 GHz), and SO (99.3 GHz) lines, and mapped with half-power beamwidths of 11'', 22'', 38'', 16'', and 36'', respectively. The two dense cores previously found in NH3 are presently confirmed in CS. The cores exhibit similar physical and chemical characteristics. The lack of outflows, the limited chemical content, and the very modest depletion in the ammonia cores provide evidence that CB238 is not an evolved object. Molecular abundances and density ratios constrain chemical modeling whose results provide a chemical age close to the free-fall timescale.

  3. A 2MASS Analysis of the Stability of Southern Bok Globules

    CERN Document Server

    Racca, Germán A; de la Reza, Ramiro

    2008-01-01

    We used near-infrared 2MASS data to construct visual extinction maps of a sample of Southern Bok globules utilizing the NICE method. We derived radial extinction profiles of dense cores identified in the globules and analyzed their stability against gravitational collapse with isothermal Bonnor-Ebert spheres. The frequency distribution of the stability parameter xi_max of these cores shows that a large number of them are located in stable states, followed by an abrupt decrease of cores in unstable states. This decrease is steeper for globules with associated IRAS point sources than for starless globules. Moreover, globules in stable states have a Bonnor-Ebert temperature of T = 15 +- 6 K, while the group of critical plus unstable globules has a different temperature of T = 10 +- 3 K. Distances were estimated to all the globules studied in this work and the spectral class of the IRAS sources was calculated. No variations were found in the stability parameters of the cores and the spectral class of their associ...

  4. Intramedullary fat globules related to bone trauma: a new MR imaging finding

    International Nuclear Information System (INIS)

    The purpose of this study is to describe intraosseous fat globules related to bone trauma that are detectable with magnetic resonance imaging (MRI), to define the relationship of this finding to fracture and bone contusion, to establish the frequency and associated findings. A proposed pathogenesis is presented. We retrospectively reviewed 419 knee MRI examinations in patients with a history of recent injury and MRI findings of fracture or bone contusion. As a control population, 268 knee MRI examinations in patients without MRI findings of recent bone injury were also reviewed. Eight of 419 (1.9 %) patients with acute or subacute knee injury with positive findings of osseous trauma on MRI demonstrated intraosseous fat globules. The mean age of patients with fat globules was greater than that of those without fat globules, and the finding was more commonly seen in women. Fat globules were hyperintense to the normal fatty marrow present elsewhere in the bone on TI-weighted imaging and had a surrounding halo of high signal intensity on fluid-sensitive imaging. Intramedullary fat globules related to bone injury visible on MRI are thought to be due to coalesced fat released by the necrosis of fatty marrow cells. The pathogenesis is supported by histologic studies of fat globules related to osteomyelitis, bone contusions and fractures. As the medullary cavity of long bones in older patients contains more fat than hematopoetic bone marrow, it is likely that this finding is more common with advancing age. (orig.)

  5. Intramedullary fat globules related to bone trauma: a new MR imaging finding

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Adelaine; Grando, Higor; Fliszar, Evelyne; Pathria, Mini; Resnick, Donald [UCSD Radiology, Musculoskeletal Division, San Diego, CA (United States); Chang, Eric Y. [UCSD Radiology, Musculoskeletal Division, San Diego, CA (United States); VA San Diego Healthcare System, Department of Radiology, San Diego, CA (United States)

    2014-12-15

    The purpose of this study is to describe intraosseous fat globules related to bone trauma that are detectable with magnetic resonance imaging (MRI), to define the relationship of this finding to fracture and bone contusion, to establish the frequency and associated findings. A proposed pathogenesis is presented. We retrospectively reviewed 419 knee MRI examinations in patients with a history of recent injury and MRI findings of fracture or bone contusion. As a control population, 268 knee MRI examinations in patients without MRI findings of recent bone injury were also reviewed. Eight of 419 (1.9 %) patients with acute or subacute knee injury with positive findings of osseous trauma on MRI demonstrated intraosseous fat globules. The mean age of patients with fat globules was greater than that of those without fat globules, and the finding was more commonly seen in women. Fat globules were hyperintense to the normal fatty marrow present elsewhere in the bone on TI-weighted imaging and had a surrounding halo of high signal intensity on fluid-sensitive imaging. Intramedullary fat globules related to bone injury visible on MRI are thought to be due to coalesced fat released by the necrosis of fatty marrow cells. The pathogenesis is supported by histologic studies of fat globules related to osteomyelitis, bone contusions and fractures. As the medullary cavity of long bones in older patients contains more fat than hematopoetic bone marrow, it is likely that this finding is more common with advancing age. (orig.)

  6. Genome-wide transcriptional profiling of the purple sulfur bacterium Allochromatium vinosum DSM 180T during growth on different reduced sulfur compounds.

    Science.gov (United States)

    Weissgerber, Thomas; Dobler, Nadine; Polen, Tino; Latus, Jeanette; Stockdreher, Yvonne; Dahl, Christiane

    2013-09-01

    The purple sulfur bacterium Allochromatium vinosum DSM 180(T) is one of the best-studied sulfur-oxidizing anoxygenic phototrophic bacteria, and it has been developed into a model organism for laboratory-based studies of oxidative sulfur metabolism. Here, we took advantage of the organism's high metabolic versatility and performed whole-genome transcriptional profiling to investigate the response of A. vinosum cells upon exposure to sulfide, thiosulfate, elemental sulfur, or sulfite compared to photoorganoheterotrophic growth on malate. Differential expression of 1,178 genes was observed, corresponding to 30% of the A. vinosum genome. Relative transcription of 551 genes increased significantly during growth on one of the different sulfur sources, while the relative transcript abundance of 627 genes decreased. A significant number of genes that revealed strongly enhanced relative transcription levels have documented sulfur metabolism-related functions. Among these are the dsr genes, including dsrAB for dissimilatory sulfite reductase, and the sgp genes for the proteins of the sulfur globule envelope, thus confirming former results. In addition, we identified new genes encoding proteins with appropriate subcellular localization and properties to participate in oxidative dissimilatory sulfur metabolism. Those four genes for hypothetical proteins that exhibited the strongest increases of mRNA levels on sulfide and elemental sulfur, respectively, were chosen for inactivation and phenotypic analyses of the respective mutant strains. This approach verified the importance of the encoded proteins for sulfur globule formation during the oxidation of sulfide and thiosulfate and thereby also documented the suitability of comparative transcriptomics for the identification of new sulfur-related genes in anoxygenic phototrophic sulfur bacteria. PMID:23873913

  7. The antiproliferative properties of the milk fat globule membrane are affected by extensive heating

    OpenAIRE

    Zanabria, Romina; Tellez, Angela; Griffiths, Mansel; Corredig, Milena

    2014-01-01

    The milk fat globule membrane (MFGM), the material surrounding milk fat globules, is not only interesting from a technological standpoint but it also shows great potential as a health ingredient, as it exerts cytotoxic and apoptotic effects against colon cancer cells. Although the effects of milk processing on the MFGM composition and functionality are well documented, less is understood on how processing may affect its bioactivity. This study aimed to determine if heating can affect the anti...

  8. Investigations of the health benefits of buttermilk fat globule membrane lipid components

    OpenAIRE

    Kuchta, Anna

    2011-01-01

    The milk fat globule membrane (MFGM) that surrounds fat globules in milk is a natural source of sphingolipids, phoshpholipids and proteins with defined anticancer properties. Dairy processing operations can affect the structure and composition of MFGM, potentially influencing its anticancer activity. The aim of this project was to determine if anticancer activity can be attributed to sweet and fermented buttermilks which contain fragments of MFGM and examine if different milk processing o...

  9. Sulfur cycle

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.

    Microbes, especially bacteria, play an important role in oxidative and reductive cycle of sulfur. The oxidative part of the cycle is mediated by photosynthetic bacteria in the presence of light energy and chemosynthetic forms in the absence of light...

  10. Isolated milk fat globules as substrate for lipoprotein lipase: study of factors relevant to spontaneous lipolysis in milk

    Energy Technology Data Exchange (ETDEWEB)

    Sundheim, G.; Bengtsson-Olivecrona, G.

    1987-03-01

    Fat globules isolated from normal and from spontaneous milk samples were compared as substrates for purified lipoprotein lipase. Only slight differences were observed. Fat globules isolated from fresh warm milk were almost resistant to lipolysis. This included globules from milk prone to spontaneous lipolysis. Cooling made the globules accessible to rapid lipolysis even if they were from normal milk. Rewarming the fat globules did not reverse the process. Maximum rate of lipolysis (after rewarming) required fat globules be stored at 10/sup 0/C or below for 5 to 10 h. Lipolysis at 4/sup 0/C usually started after a lag time of 3 to 5 h, but with fat globules from spontaneous milk the lag time was shorter. Fat globules isolated from cold milk were a poor substrate at 4/sup 0/C but were lipolyzed when warmed. When /sup 125/I-labeled lipase was added to fresh warm milk, some of the lipase bound to the milk fat globules but it caused little lipolysis. Binding increased after cooling, as did lipolysis. Both binding of lipase and lipolysis were impeded by the presence of skim milk. Another way to make fat globules isolated from fresh warm milk susceptible to lipolysis was to treat them with chemicals known to remove proteins.

  11. Isolated milk fat globules as substrate for lipoprotein lipase: study of factors relevant to spontaneous lipolysis in milk

    International Nuclear Information System (INIS)

    Fat globules isolated from normal and from spontaneous milk samples were compared as substrates for purified lipoprotein lipase. Only slight differences were observed. Fat globules isolated from fresh warm milk were almost resistant to lipolysis. This included globules from milk prone to spontaneous lipolysis. Cooling made the globules accessible to rapid lipolysis even if they were from normal milk. Rewarming the fat globules did not reverse the process. Maximum rate of lipolysis (after rewarming) required fat globules be stored at 100C or below for 5 to 10 h. Lipolysis at 40C usually started after a lag time of 3 to 5 h, but with fat globules from spontaneous milk the lag time was shorter. Fat globules isolated from cold milk were a poor substrate at 40C but were lipolyzed when warmed. When 125I-labeled lipase was added to fresh warm milk, some of the lipase bound to the milk fat globules but it caused little lipolysis. Binding increased after cooling, as did lipolysis. Both binding of lipase and lipolysis were impeded by the presence of skim milk. Another way to make fat globules isolated from fresh warm milk susceptible to lipolysis was to treat them with chemicals known to remove proteins

  12. Biodegradation of Various Aromatic Compounds by Enriched Bacterial Cultures: Part B--Nitrogen-, Sulfur-, and Oxygen-Containing Heterocyclic Aromatic Compounds.

    Science.gov (United States)

    Oberoi, Akashdeep Singh; Philip, Ligy; Bhallamudi, S Murty

    2015-07-01

    Present study focused on the biodegradation of various heterocyclic nitrogen, sulfur, and oxygen (NSO) compounds using naphthalene-enriched culture. Target compounds in the study were pyridine, quinoline, benzothiophene, and benzofuran. Screening studies were carried out using different microbial consortia enriched with specific polycyclic aromatic hydrocarbon (PAH) and NSO compounds. Among different microbial consortia, naphthalene-enriched culture was the most efficient consortium based on high substrate degradation rate. Substrate degradation rate with naphthalene-enriched culture followed the order pyridine > quinoline > benzofuran > benzothiophene. Benzothiophene and benzofuran were found to be highly recalcitrant pollutants. Benzothiophene could not be biodegraded when concentration was above 50 mg/l. It was observed that 2-(1H)-quinolinone, benzothiophene-2-one, and benzofuran-2,3-dione were formed as metabolic intermediates during biodegradation of quinoline, benzothiophene, and benzofuran, respectively. Quinoline-N and pyridine-N were transformed into free ammonium ions during the biodegradation process. Biodegradation pathways for various NSO compounds are proposed. Monod inhibition model was able to simulate single substrate biodegradation kinetics satisfactorily. Benzothiophene and benzofuran biodegradation kinetics, in presence of acetone, was simulated using a generalized multi-substrate model. PMID:26054616

  13. Enhancement of Copper Availability and Microbial Community Changes in Rice Rhizospheres Affected by Sulfur

    Directory of Open Access Journals (Sweden)

    Xiao-Feng Yuan

    2011-02-01

    Full Text Available The role of sulfur on the availability of Cu and the bacterial community in rice rhizospheres was investigated by pot experiments. With sulfur addition, pH in rhizosphere soil decreased and Mg(NO32 extractable Cu increased significantly. The bacterial community composition also changed with sulfur addition. Some specific clones having high similarity to Thiobacillus, which indicated that sulfur oxidation in the rice rhizosphere could increase the availability of Cu. These results suggested that sulfur source which could provide substrate to sulfur oxidizing bacteria and enhance the availability of Cu was not a suitable sulfur fertilizer for Cu polluted soil.

  14. Regulation of dissimilatory sulfur oxidation in the purple sulfur bacterium Allochromatium vinosum

    Directory of Open Access Journals (Sweden)

    ChristianeDahl

    2011-03-01

    Full Text Available In the purple sulfur bacterium Allochromatium vinosum, thiosulfate oxidation is strictly dependent on the presence of three periplasmic Sox proteins encoded by the soxBXAK and soxYZ genes. It is also well documented that proteins encoded in the dsr (dissimilatory sulfite reductase operon, dsrABEFHCMKLJOPNRS, are essential for the oxidation of sulfur that is stored intracellularly as an obligatory intermediate during the oxidation of thiosulfate and sulfide. Until recently, detailed knowledge about the regulation of the sox genes was not available. We started to fill this gap and show that these genes are expressed on a low constitutive level in A. vinosum in the absence of reduced sulfur compounds. Thiosulfate and possibly sulfide lead to an induction of sox gene transcription. Additional translational regulation was not apparent. Regulation of soxXAK is probably performed by a two-component system consisting of a multisensor histidine kinase and a regulator with proposed di-guanylate cyclase activity. Previous work already provided some information about regulation of the dsr genes encoding the second important sulfur-oxidizing enzyme system in the purple sulfur bacterium. The expression of most dsr genes was found to be at a low basal level in the absence of reduced sulfur compounds and enhanced in the presence of sulfide. In the present work, we focused on the role of DsrS, a protein encoded by the last gene of the dsr locus in A. vinosum. Transcriptional and translational gene fusion experiments suggest a participation of DsrS in the post-transcriptional control of the dsr operon. Characterization of an A. vinosum ΔdsrS mutant showed that the monomeric cytoplasmic 41.1 kDa protein DsrS is important though not essential for the oxidation of sulfur stored in the intracellular sulfur globules.

  15. Study of the "Sulfur-turf" : a Community of Colorless Sulfur Bacteria Growing in Hot Spring Effluent

    OpenAIRE

    MAKI, Yonosuke

    1991-01-01

    Sulfur-turf is one of the so-called "sulfureta" which are massive aggregates of colorless sulfur bacteria. Interest in the ecological and physiological aspects of the sulfuretum has strongly increased not only due to the discovery of massive occurrence of colorless sulfur bacteria in an area of hydrothermal vents but also due to the possibility of its significant contribution to the sulfur cycle in the coastal region. Here, I review the types, habitats, and bacterial constituents of the sulfu...

  16. Sulfur Earth

    Science.gov (United States)

    de Jong, B. H.

    2007-12-01

    Variations in surface tension affect the buoyancy of objects floating in a liquid. Thus an object floating in water will sink deeper in the presence of dishwater fluid. This is a very minor but measurable effect. It causes for instance ducks to drown in aqueous solutions with added surfactant. The surface tension of liquid iron is very strongly affected by the presence of sulfur which acts as a surfactant in this system varying between 1.9 and 0.4 N/m at 10 mass percent Sulfur (Lee & Morita (2002), This last value is inferred to be the maximum value for Sulfur inferred to be present in the liquid outer core. Venting of Sulfur from the liquid core manifests itself on the Earth surface by the 105 to 106 ton of sulfur vented into the atmosphere annually (Wedepohl, 1984). Inspection of surface Sulfur emission indicates that venting is non-homogeneously distributed over the Earth's surface. The implication of such large variation in surface tension in the liquid outer core are that at locally low Sulfur concentration, the liquid outer core does not wet the predominantly MgSiO3 matrix with which it is in contact. However at a local high in Sulfur, the liquid outer core wets this matrix which in the fluid state has a surface tension of 0.4 N/m (Bansal & Doremus, 1986), couples with it, and causes it to sink. This differential and diapiric movement is transmitted through the essentially brittle mantle (1024 Pa.s, Lambeck & Johnson, 1998; the maximum value for ice being about 1030 Pa.s at 0 K, in all likely hood representing an upper bound of viscosity for all materials) and manifests itself on the surface by the roughly 20 km differentiation, about 0.1 % of the total mantle thickness, between topographical heights and lows with concomitant lateral movement in the crust and upper mantle resulting in thin skin tectonics. The brittle nature of the medium though which this movement is transmitted suggests that the extremes in topography of the D" layer are similar in range to

  17. Influence of Mucilage Viscosity On The Globule Structure And Stability Of Certain Starch Emulsions

    Directory of Open Access Journals (Sweden)

    Uhumwangho MU

    2005-05-01

    Full Text Available A study was carried out to determine the influence of mucilage viscosity on the globule structure (i.e. size and number of certain starch emulsions. The starches investigated were cassava, potato and maize. The emulsions were prepared by mixing the starch mucilage of a predetermined concentration 4%w/v with arachis oil in the ratio 50:50, using a silverson mixer fitted with a dispersator head. The emulsions were stored at room temperature (28±20C for 7 days. Changes in globule size were monitored by photomicroscopy. Viscosities of the mucilage and those of resulting emulsions were determined using a capillary flow method. The viscosities of the emulsions expressed as time of flow (seconds, were 680 (cassava starch, 369 (potato starch and 270 (Maize starch, and for the mucilage 510 (cassava, 336 (potato and 248 (maize. The corresponding mean globule sizes of the fresh emulsions were (µm 28±6, 42±6 and 45±5 respectively. The increase in globule size during storage (measure of globule coalescence rate was 1.8±0.2µm day -1 (cassava, 3.5±0.2µm day -1 (potato and 4.6±0.3µm day -1 (maize. Thus, a higher viscosity of the dispersion medium is associated with the production of finer and more stable emulsions.

  18. Cytoplasmic sulfurtransferases in the purple sulfur bacterium Allochromatium vinosum: evidence for sulfur transfer from DsrEFH to DsrC.

    Directory of Open Access Journals (Sweden)

    Yvonne Stockdreher

    Full Text Available While the importance of sulfur transfer reactions is well established for a number of biosynthetic pathways, evidence has only started to emerge that sulfurtransferases may also be major players in sulfur-based microbial energy metabolism. Among the first organisms studied in this regard is the phototrophic purple sulfur bacterium Allochromatium vinosum. During the oxidation of reduced sulfur species to sulfate this Gammaproteobacterium accumulates sulfur globules. Low molecular weight organic persulfides have been proposed as carrier molecules transferring sulfur from the periplasmic sulfur globules into the cytoplasm where it is further oxidized via the "Dsr" (dissimilatory sulfite reductase proteins. We have suggested earlier that the heterohexameric protein DsrEFH is the direct or indirect acceptor for persulfidic sulfur imported into the cytoplasm. This proposal originated from the structural similarity of DsrEFH with the established sulfurtransferase TusBCD from E. coli. As part of a system for tRNA modification TusBCD transfers sulfur to TusE, a homolog of another crucial component of the A. vinosum Dsr system, namely DsrC. Here we show that neither DsrEFH nor DsrC have the ability to mobilize sulfane sulfur directly from low molecular weight thiols like thiosulfate or glutathione persulfide. However, we demonstrate that DsrEFH binds sulfur specifically to the conserved cysteine residue DsrE-Cys78 in vitro. Sulfur atoms bound to cysteines in DsrH and DsrF were not detected. DsrC was exclusively persulfurated at DsrC-Cys111 in the penultimate position of the protein. Most importantly, we show that persulfurated DsrEFH indeed serves as an effective sulfur donor for DsrC in vitro. The active site cysteines Cys78 of DsrE and Cys20 of DsrH furthermore proved to be essential for sulfur oxidation in vivo supporting the notion that DsrEFH and DsrC are part of a sulfur relay system that transfers sulfur from a persulfurated carrier molecule to the

  19. Study of grain alignment efficiency and a distance estimate for small globule CB4

    International Nuclear Information System (INIS)

    We study the polarization efficiency (defined as the ratio of polarization to extinction) of stars in the background of the small, nearly spherical and isolated Bok globule CB4 to understand the grain alignment process. A decrease in polarization efficiency with an increase in visual extinction is noticed. This suggests that the observed polarization in lines of sight which intercept a Bok globule tends to show dominance of dust grains in the outer layers of the globule. This finding is consistent with the results obtained for other clouds in the past. We determined the distance to the cloud CB4 using near-infrared photometry (2MASS JHKS colors) of moderately obscured stars located at the periphery of the cloud. From the extinction-distance plot, the distance to this cloud is estimated to be (459 ± 85) pc. (paper)

  20. Influence of Mucilage Viscosity On The Globule Structure And Stability Of Certain Starch Emulsions

    OpenAIRE

    Uhumwangho MU; Okor RS; Ayomanor M

    2005-01-01

    A study was carried out to determine the influence of mucilage viscosity on the globule structure (i.e. size and number) of certain starch emulsions. The starches investigated were cassava, potato and maize. The emulsions were prepared by mixing the starch mucilage of a predetermined concentration 4%w/v with arachis oil in the ratio 50:50, using a silverson mixer fitted with a dispersator head. The emulsions were stored at room temperature (28±20C) for 7 days. Changes in globule size were mon...

  1. Tracing the evolutionary stage of Bok globules: CCS and NH3

    OpenAIRE

    Marka, C.; Schreyer, K.; Launhardt, R.; Semenov, D. A.; Henning, Th.

    2011-01-01

    We pursue the investigation of a previously proposed correlation between chemical properties and physical evolutionary stage of isolated low-mass star-forming regions. In the past, the NH3/CCS abundance ratio was suggested to be a potentially useful indicator for the evolutionary stage of cloud cores. We aim to study its applicability for isolated Bok globules. A sample of 42 Bok globules with and without signs of current star formation was searched for CCS(2-1) emission, the observations wer...

  2. Polymers in crowded environment under stretching force: Globule-coil transitions.

    Science.gov (United States)

    Blavatska, Viktoria; Janke, Wolfhard

    2009-11-01

    We study flexible polymer macromolecules in a crowded (porous) environment, modeling them as self-attracting self-avoiding walks on site-diluted percolative lattices in space dimensions d=2,3 . The influence of stretching force on the polymer folding and the properties of globule-coil transitions are analyzed. Applying the pruned-enriched Rosenbluth chain-growth method, we estimate the transition temperature TTheta between collapsed and extended polymer configurations and construct the phase diagrams of the globule-coil coexistence when varying temperature and stretching force. The transition to a completely stretched state, caused by applying force, is discussed as well. PMID:20364999

  3. Coil-globule transition of a single short polymer chain: an exact enumeration study.

    Science.gov (United States)

    Ponmurugan, M; Narasimhan, S L; Krishna, P S R; Murthy, K P N

    2007-04-14

    The authors present an exact enumeration study of short self-avoiding walks in two as well as in three dimensions that addresses the question, "what is the shortest walk for which the existence of all the three scaling regimes--coil, globule, and the theta--could be demonstrated." Even though they could easily demonstrate the coil and the globule phase from free energy considerations, they could demonstrate the existence of a theta temperature only by using a scaling form for the distribution of gyration radius. That even such short walks have a scaling behavior is an unexpected result of this work. PMID:17444742

  4. Globules and pillars seen in the [CII] 158 micron line with SOFIA

    CERN Document Server

    Schneider, N; Tremblin, P; Hennemann, M; Minier, V; Hill, T; Comerón, F; Requena-Torres, M A; Kraemer, K E; Simon, R; Röllig, M; Stutzki, J; Djupvik, A A; Zinnecker, H; Marston, A; Csengeri, T; Cormier, D; Lebouteiller, V; Audit, E; Motte, F; Bontemps, S; Sandell, G; Allen, L; Megeath, T; Gutermuth, R A

    2012-01-01

    Molecular globules and pillars are spectacular features, found only in the interface region between a molecular cloud and an HII-region. Impacting Far-ultraviolet (FUV) radiation creates photon dominated regions (PDRs) on their surfaces that can be traced by typical cooling lines. With the GREAT receiver onboard SOFIA we mapped and spectrally resolved the [CII] 158 micron atomic fine-structure line and the highly excited 12CO J=11-10 molecular line from three objects in Cygnus X (a pillar, a globule, and a strong IRAS source). We focus here on the globule and compare our data with existing Spitzer data and recent Herschel Open-Time PACS data. Extended [CII] emission and more compact CO-emission was found in the globule. We ascribe this emission mainly to an internal PDR, created by a possibly embedded star-cluster with at least one early B-star. However, external PDR emission caused by the excitation by the Cyg OB2 association cannot be fully excluded. The velocity-resolved [CII] emission traces the emission ...

  5. Polymer globule with fractal properties caused by intramolecular nanostructuring and spatial constrains.

    Science.gov (United States)

    Glagoleva, Anna A; Vasilevskaya, Valentina V; Khokhlov, Alexei R

    2016-06-21

    By means of computer simulation, we studied macromolecules composed of N dumbbell amphiphilic monomer units with attractive pendant groups. In poor solvents, these macromolecules form spherical globules that are dense in the case of short chains (the gyration radius RG∼N(1/3)), or hollow inside and obey the RG∼N(1/2) law when the macromolecules are sufficiently long. Due to the specific intramolecular nanostructuring, the vesicle-like globules of long amphiphilic macromolecules posses some properties of fractal globules, by which they (i) could demonstrate the same scaling statistics for the entire macromolecule and for short subchains with m monomer units and (ii) possess a specific territorial structure. Within a narrow slit, the globule loses its inner cavity, takes a disk-like shape and scales as N(1/2) for much shorter macromolecules. However, the field of end-to-end distance r(m) ∼m(1/2) dependence for subchains becomes visibly smaller. The results obtained were compared with the homopolymer case. PMID:27198966

  6. Coil–globule transition of a polymer involved in excluded-volume interactions with macromolecules

    International Nuclear Information System (INIS)

    Polymers adopt extended coil and compact globule states according to the balance between entropy and interaction energies. The transition of a polymer between an extended coil state and compact globule state can be induced by changing thermodynamic force such as temperature to alter the energy/entropy balance. Previously, this transition was theoretically studied by taking into account the excluded-volume interaction between monomers of a polymer chain using the partition function. For binary mixtures of a long polymer and short polymers, the coil-globule transition can be induced by changing the concentration of the shorter polymers. Here, we investigate the transition caused by short polymers by generalizing the partition function of the long polymer to include the excluded-volume effect of short polymers. The coil-globule transition is studied as a function of the concentration of mixed polymers by systematically varying Flory’s χ-parameters. We show that the transition is caused by the interplay between the excluded-volume interaction and the dispersion state of short polymers in the solvent. We also reveal that the same results can be obtained by combining the mixing entropy and elastic energy if the volume of a long polymer is properly defined

  7. Infrared study of new star cluster candidates associated to dusty globules

    Science.gov (United States)

    Soto King, P.; Barbá, R.; Roman-Lopes, A.; Jaque, M.; Firpo, V.; Nilo, J. L.; Soto, M.; Minniti, D.

    2014-10-01

    We present results from a study of a sample of small star clusters associated to dusty globules and bright-rimmed clouds that have been observed under ESO/Chile public infrared survey Vista Variables in the Vía Láctea (VVV). In this short communication, we analyse the near-infrared properties of a set of four small clusters candidates associated to dark clouds. This sample of clusters associated to dusty globules are selected from the new VVV stellar cluster candidates developed by members of La Serena VVV Group (Barbá et al. 2014). Firstly, we are producing color-color and color-magnitude diagrams for both, cluster candidates and surrounding areas for comparison through PSF photometry. The cluster positions are determined from the morphology on the images and also from the comparison of the observed luminosity function for the cluster candidates and the surrounding star fields. Now, we are working in the procedures to establish the full sample of clusters to be analyzed and methods for subtraction of the star field contamination. These clusters associated to dusty globules are simple laboratories to study the star formation relatively free of the influence of large star-forming regions and populous clusters, and they will be compared with those clusters associated to bright-rimmed globules, which are influenced by the energetic action of nearby O and B massive stars.

  8. Molten globule state of tear lipocalin: ANS binding restores tertiary interactions

    International Nuclear Information System (INIS)

    Tear lipocalin (TL) may stabilize the lipid layer of tears through a molten globule state triggered by low pH. EPR spectroscopy with site-directed spin labeling, revealed the side chain mobility of residues on the G-strand of TL in a molten globule state; the G-strand retains β-sheet structure. All of the side chains of G-strand residues become more loosely packed, especially residues 96-99. In contrast, the highly mobile side chain of residue 95 on the F-G loop, becomes tightly packed. ANS binding to TL in a molten globule state reestablishes tight packing around side chains that are oriented both inside and outside of the barrel. Unlike RBP and BLG; TL has no disulfide bond between G- and H-strands. It is likely that the central β-sheet in the molten globule state of lipocalins is stabilized by its interactions with the main α-helix, rather than the interstrand disulfide bond

  9. Sulfur metabolism in phototrophic sulfur bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Dahl, Christiane

    2008-01-01

    Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB). They...... utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms in...... other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative of the...

  10. Relationship between fat globule size and chemical and fatty acid composition of cow's milk in mid lactation

    Directory of Open Access Journals (Sweden)

    Mina Martini

    2006-01-01

    Full Text Available The milk in 57 Italian Fresian cows in mid lactation was analysed in order to define the relationship between some qualitative milk parameters and the size of milk fat globules. The study focused on the morphometric evaluation of milk fat globules, chemical parameteres and fatty acid composition of the milk. The results show that a prevalence of milk fat globules with a diameter 6 um was associated (P<0.01 with greater milk yield nad a higher percentage of lactose, non-fat dry matter and ash............

  11. Bacterial gastroenteritis

    Science.gov (United States)

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

  12. Modulation of current through a nanopore induced by a charged globule: implications for DNA-docking

    CERN Document Server

    Chinappi, Mauro; Cecconi, Fabio; Marconi, Umberto Marini Bettolo; Melchionna, Simone

    2015-01-01

    The passage of DNA through a nanopore can be effectively decomposed into two distinct phases, docking and actual translocation. In experiments each phase is characterized by a distinct current signature which allows the discrimination of the two events. However, at low voltages a clear distinction of the two phases is lost. By using numerical simulations we clarify how the current signature associated to the docking events depends on the applied voltage. The simulations show that at small voltage the DNA globule enhances the pore conductance due to an enrichment of charge carriers. At high voltage, the globule drains substantial charge carriers from the pore region, thereby reducing the overall conductance. The results provide a new interpretation to the experimental data on conductance and show how docking interferes with the translocation signal, of potential interest for sequencing applications.

  13. Histochemical and biochemical observations on milk-fat-globule membranes from several mammalian species.

    Science.gov (United States)

    Welsch, U; Schumacher, U; Buchheim, W; Schinko, I; Jenness, P; Patton, S

    1990-01-01

    A specific secretory product of the lactating mammary gland are triglyceride fat globules which are enveloped by a very complex membrane, the milk fat globule membrane (MFGM). In different mammalian species (man, rhesus monkey, horse, goat, sheep, cow, grey seal, camel, alpaka) the glycoproteins of this membrane have been analyzed by gel electrophoresis, Western blotting and lectin histochemistry. A remarkable intra- and interspecific variability of these glycoproteins has been detected pointing to so far unknown physiological adaptions, which may play a role in the intestine of the new born. High molecular weight glycoproteins, with a very high degree of glycosilation have been found only in primates, horse and camel; the MFGMs of the true ruminants (cow, sheep, goat) are characterized by specific glycoproteins of a lower molecular weight range. PMID:2091048

  14. Comparison of Milk Fat Globule Membrane (MFGM) Proteins of Chianina and Holstein Cattle Breed Milk Samples Through Proteomics Methods

    OpenAIRE

    Lorraine Pariset; Silvia Bongiorni; Alessio Valentini; Lello Zolla; Leonardo Murgiano; Anna Maria Timperio

    2009-01-01

    Identification of proteins involved in milk production is important to understand the biology of lactation. Many studies have advanced the understanding of mammary function and milk secretion, but the critical molecular mechanisms implicated in milk fat secretion is still incomplete. Milk Fat Globules are secreted from the apical surface of the mammary cells, surrounded by a thin membrane bilayer, the Milk Fat Globule Membrane (MFGM), formed by proteins which have been suggested to be cholest...

  15. Impaired involution of mammary glands in the absence of milk fat globule EGF factor 8

    OpenAIRE

    Hanayama, Rikinari; Nagata, Shigekazu

    2005-01-01

    During the involution of mammary glands, epithelial cells undergo apoptosis and are cleared for the next cycle of lactation. The clearance of apoptotic epithelial cells is mediated by neighboring epithelial cells and by macrophages that migrate into the mammary glands. Here, we report that milk fat globule EGF factor 8 (MFG-E8), a secreted glycoprotein that binds to apoptotic cells by recognizing phosphatidylserine, was expressed by epithelial cells and macrophages in mammary glands and was i...

  16. Solvent extraction of elemental sulfur from coal and a determination of its source using stable sulfur isotopes

    Science.gov (United States)

    Hackley, Keith C.; Buchanan, D.H.; Coombs, K.; Chaven, C.; Kruse, C.W.

    1990-01-01

    Hot tetrachloroethene (perchloroethylene, PCE) extracts significant amounts of elemental sulfur (So) from weathered coals but not from pristine coals. The objective of this study was to determine whether So extracted by PCE is an oxidation product of pyrite or whether it originates in some way from unstable, organically-bound sulfur. The isotopic composition of the PCE-extracted So was compared to the isotopic compositions of the pyritic and the organic sulfur in a coal. The So was shown to have an isotopic signature similar to the pyritic sulfur. Additionally, the isotopic differences observed between the pyritic, So and sulfatic sulfur were consistent with bacterial mediated oxidation of sulfide sulfur (pyrite) as the source of both the sulfatic and elemental sulfur. ?? 1990.

  17. Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria

    Directory of Open Access Journals (Sweden)

    Niels-UlrikFrigaard

    2011-05-01

    Full Text Available Green sulfur bacteria (GSB constitute a closely related group of photoautotrophic and thiotrophic bacteria with limited phenotypic variation. They typically oxidize sulfide and thiosulfate to sulfate with sulfur globules as an intermediate. Based on genome sequence information from 15 strains, the distribution and phylogeny of enzymes involved in their oxidative sulfur metabolism was investigated. At least one homolog of sulfide:quinone oxidoreductase (SQR is present in all strains. In all sulfur-oxidizing GSB strains except the earliest diverging Chloroherpeton thalassium, the sulfide oxidation product is further oxidized to sulfite by the dissimilatory sulfite reductase (DSR system. This system consists of components horizontally acquired partly from sulfide-oxidizing and partly from sulfate-reducing bacteria. Depending on the strain, the sulfite is probably oxidized to sulfate by one of two different mechanisms that have different evolutionary origins: adenosine-5’-phosphosulfate reductase (APR or polysulfide reductase-like complex 3 (PSRLC3. Thiosulfate utilization by the SOX system in GSB has apparently been acquired horizontally from proteobacteria. SoxCD does not occur in GSB, and its function in sulfate formation in other bacteria has been replaced by the DSR system in GSB. Sequence analyses suggested that the conserved soxJXYZAKBW gene cluster was horizontally acquired by Chlorobium phaeovibrioides DSM 265 from the Chlorobaculum lineage and that this acquisition was mediated by a mobile genetic element. Thus, the last common ancestor of currently known GSB was probably photoautotrophic, hydrogenotrophic, and contained SQR but not DSR or SOX. In addition, the predominance of the Chlorobium-Chlorobaculum-Prosthecochloris lineage among cultured GSB could be due to the horizontally acquired DSR and SOX systems. Finally, based upon structural, biochemical, and phylogenetic analyses, a uniform nomenclature is suggested for sqr genes in

  18. Solubility of Sulfur Dioxide in Sulfuric Acid

    Science.gov (United States)

    Chang, K. K.; Compton, L. E.; Lawson, D. D.

    1982-01-01

    The solubility of sulfur dioxide in 50% (wt./wt.) sulfuric acid was evaluated by regular solution theory, and the results verified by experimental measurements in the temperature range of 25 C to 70 C at pressures of 60 to 200 PSIA. The percent (wt./wt.) of sulfur dioxide in 50% (wt./wt.) sulfuric acid is given by the equation %SO2 = 2.2350 + 0.0903P - 0.00026P 10 to the 2nd power with P in PSIA.

  19. Sulfur-Specific Microbial Desulfurization of Sterically Hindered Analogs of Dibenzothiophene

    OpenAIRE

    Lee, M. K.; Senius, J. D.; Grossman, M. J.

    1995-01-01

    Dibenzothiophenes (DBTs) bearing alkyl substitutions adjacent to the sulfur atom, such as 4,6-diethyldibenzothiophene (4,6-DEDBT), are referred to as sterically hindered with regard to access to the sulfur moiety. By using enrichment cultures with 4,6-DEDBT as the sole sulfur source, bacterial isolates which selectively remove sulfur from sterically hindered DBTs were obtained. The isolates were tentatively identified as Arthrobacter species. 4,6-DEDBT sulfone was shown to be an intermediate ...

  20. Amiata donkeys: fat globule characteristics, milk gross composition and fatty acids

    Directory of Open Access Journals (Sweden)

    Mina Martini

    2014-02-01

    Full Text Available Amiata donkeys are a native breed reared in central Italy. Safeguarding native donkey breeds represents an opportunity for the development of marginal areas, especially given that donkey milk is now appearing on the market due to its potential benefits for human health. To date, only a few studies have focused on the characteristics of the milk fat globules (MFGs in the donkey species. The aim of this study was to assess the morphometric characteristics of the fat globules, gross composition and fatty acid classes in milk from Amiata donkeys reared according to the typical farming and feeding systems of the area of origin. Individual milk samples, collected from 28 Amiata donkeys between 90 and 150 days of lactation, showed the following average composition (g/100 mL: 9.47 dry matter, 1.63 protein, 0.78 casein, 0.53 fat, 7.12 lactose, and 0.36 ash. The unsaturated:saturated fatty acids ratio in milk was close to 1. The percentage of short chains was 12.29, and the percentage of long chain fatty acids was 47.64. The donkey MFGs showed an average diameter of 1.92 μm, and a number of 2.18*109/mL. Regarding MFG distribution, 70% of the globules donkey of milk are smaller than 2 μm. In conclusion, the gross composition and fatty acids of Amiata donkey milk showed similarities with milk from other Italian donkey breeds, with the exception of the monounsaturated fatty acid values which were slightly higher. Donkey MFGs had a smaller diameter and were fewer than in the ruminant species.

  1. Explicit-ion Effects in the Coil-Globule Transition of Weak Polyelectrolytes

    Science.gov (United States)

    Sikora, Benjamin J.; Whitmer, Jonathan K.

    The first-order coil-globule transition in weak (annealed) polyelectrolytes involves a subtle balance of pH, charge strength, and solvation forces. In this work, we utilize a coarse-grain hybrid grand-canonical Monte Carlo and Molecular Dynamics approach to explore the free energetic topography of a model hydrophobic polybase [representing poly(2-vinylpyridine) (P2VP)] and explore the role of salt concentration/valency in influencing polyelectrolyte conformations using both an implicit Debye-Hückel and explicit salt approach. Our simulations reproduce the experimentally measured behavior for dilute annealed polyelectrolytes, and present a solid foundation for understanding pH responsive polyelectrolyte materials.

  2. Phase transitions of a polymer threading a membrane coupled to coil-globule transitions

    OpenAIRE

    Matsuyama, Akihiko

    2004-01-01

    We theoretically study phase transitions of a polymer threading through a pore imbedded in a membrane. We focus on the coupling between a partition of the polymer segments through the membrane and a coil-globule transition of the single polymer chain. Based on the Flory model for collapse transitions of a polymer chain, we calculate the fraction of polymer segments and the expansion factor of a polymer coil on each side of the membrane. We predict a first-order phase transition of a polymer t...

  3. Sulfuric acid on Europa and the radiolytic sulfur cycle

    Science.gov (United States)

    Carlson, R. W.; Johnson, R. E.; Anderson, M. S.

    1999-01-01

    A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes.

  4. The three-dimensional folding of the α-globin gene domain reveals formation of chromatin globules.

    Science.gov (United States)

    Baù, Davide; Sanyal, Amartya; Lajoie, Bryan R; Capriotti, Emidio; Byron, Meg; Lawrence, Jeanne B; Dekker, Job; Marti-Renom, Marc A

    2011-01-01

    We developed a general approach that combines chromosome conformation capture carbon copy (5C) with the Integrated Modeling Platform (IMP) to generate high-resolution three-dimensional models of chromatin at the megabase scale. We applied this approach to the ENm008 domain on human chromosome 16, containing the α-globin locus, which is expressed in K562 cells and silenced in lymphoblastoid cells (GM12878). The models accurately reproduce the known looping interactions between the α-globin genes and their distal regulatory elements. Further, we find using our approach that the domain folds into a single globular conformation in GM12878 cells, whereas two globules are formed in K562 cells. The central cores of these globules are enriched for transcribed genes, whereas nontranscribed chromatin is more peripheral. We propose that globule formation represents a higher-order folding state related to clustering of transcribed genes around shared transcription machineries, as previously observed by microscopy. PMID:21131981

  5. The dynamics of the biological membrane surrounding the buffalo milk fat globule investigated as a function of temperature.

    Science.gov (United States)

    Nguyen, Hanh T H; Madec, Marie-Noëlle; Ong, Lydia; Kentish, Sandra E; Gras, Sally L; Lopez, Christelle

    2016-08-01

    The biological membrane surrounding fat globules in milk (the MFGM) is poorly understood, despite its importance in digestion and in determining the properties of fat globules. In this study, in situ structural investigations of buffalo MFGM were performed as a function of temperature (4-60°C), using confocal microscopy. We demonstrate that temperature and rate of temperature change affected the lipid domains formed in the MFGM with the lateral segregation (i) of high Tm lipids and cholesterol in a Lo phase for both TTm and (ii) of high Tm lipids in a gel phase for Tglobules during processing and digestion. PMID:26988511

  6. Micro-PIXE characterization of amorphous silica globules from a hydrothermal field on the sea floor of Okinawa, Southern Japan

    International Nuclear Information System (INIS)

    During the examination of the representative specimens, a barite ore and a polymetallic chimney, from the JADE hydrothermal field of Okinawa Trough, many amorphous silica globules of approximately 10 to 50 micrometers in diameter were found as isolated sphere or bunchy aggregation. We performed micro-PIXE analyses of the globules to check the effectiveness of the method to such soft and vulnerable material, and to understand the geochemical characteristics. The result shows that amorphous silica can include various kinds of elements in lithophile, chalcophile and siderophile categories. The trace element distribution of the globules indicates that amorphous silica could be a good monitor of geochemical environment; and implies that the chemical variation of ore often in a mineral field is mainly derived by change in local physicochemical conditions of single mineralizing fluid rather than multiple injection of the solution. (author)

  7. Sulfur isotope in nature. Determination of sulfur isotope ratios in coal and petroleum by mass spectrometry

    International Nuclear Information System (INIS)

    Elementary sulfur or in chemical compounds is one of the elements widespread in the earth's crust and biosphere. Its participation in earth's crust amounts to 0.26 % by weight. Measurement of isotope composition of natural samples can deliver many information about origin, creation and transformation ranges of rocks and minerals. Sulfur isotope ratio contained in minerals is variable and for this reason investigation of isotope sulfur composition can deliver useful information about the geochemistry of each component. Therefore in the investigated sample it is necessary to determine not only the content of sulfur but also the isotope composition of each component. Differentiation of contents of sulfur-34 in natural sulfur compounds can reach up to 110 per mile. So large divergences can be explained by a kinetic effect or by bacterial reduction of sulphates. In this report a wide review of the results of investigations of isotope sulfur compositions in coal and petroleum are presented as well as the methods for the preparation of samples for mass spectrometry analysis are proposed. (author)

  8. Fitting a Turbulent Cloud Model to CO Observations of Starless Bok Globules

    Science.gov (United States)

    Hegmann, M.; Hengel, C.; Röllig, M.; Kegel, W. H.

    We present observations of five starless Bok globules in transitions of 12CO (J=2-1 and {J=3-2}), 13CO (J=2-1), and C18O (J=2-1) which have been obtained at the Heinrich-Hertz-Telescope. For an analysis of the data we use the model of Kegel et al. (see e.g. Piehler & Kegel 1995, A&A 297, 841; Hegmann & Kegel 2000, A&A 359, 405) which describes an isothermal sphere stabilized by turbulent and thermal pressure. This approach deals with the full NLTE radiative transfer problem and accounts for a turbulent velocity field with finite correlation length. By a comparison of observed and calculated line profiles we are able not only to determine the kinetic temperature, hydrogen density and CO coloumn density of the globules, but also to study the properties of the turbulent velocity field, i.e. the variance of its one-point-distribution and its correlation length. We consider our model to be an alternative tool for the evaluation of molecular lines emitted by molecular clouds. The model assumptions are certainly closer to reality than the assumptions behind the standard evaluation models, as for example the LVG model. Our current study shows that that the results obtained from our model can differ significantly from those obtained from a LVG analysis.

  9. Properties of protostars in the Elephant Trunk globule IC 1396A

    CERN Document Server

    Reach, William T; Rho, Jeonghee; Boogert, Adwin; Tappe, Achim; Jarrett, Thomas H; Morris, Patrick; Cambresy, Laurent; Palla, Francesco; Valdettaro, Riccardo

    2008-01-01

    Extremely red objects, identified in the early Spitzer Space Telescope observations of the bright-rimmed globule IC 1396A and photometrically classified as Class I protostars Class II T Tauri stars based on their mid-infrared colors, were observed spectroscopically at 5.5 to 38 microns (IRS), at the 22 GHz water maser frequency (GBT), and in the optical (Palomar). The sources photometrically identified as Class I are confirmed as objects dominated by accretion luminosity from dense envelopes, with accretion rates 1e-5 to 1e-6 Msun/yr. The ice/silicate absorption ratio in the envelope is exceptionally low for the IC 1396A protostars, compared to those in nearby star-forming regions, suggesting the envelope chemistry is altered by the radiation field or globule pressure. Only one 22 GHz water maser was detected in IC 1396A; its infrared counterpart has luminosity <0.1 Lsun, the first H2O maser from such a low-luminosity object. The objects photometrically classified as Class II are confirmed as classical T T...

  10. Pillars and globules at the edges of H ii regions, Confronting Herschel observations and numerical simulations

    CERN Document Server

    Tremblin, P; Schneider, N; Audit, E; Hill, T; Didelon, P; Peretto, N; Arzoumanian, D; Motte, F; Zavagno, A; Bontemps, S; Anderson, L D; Andre, Ph; Bernard, J P; Csengeri, T; Di Francesco, J; Elia, D; Hennemann, M; Konyves, V; Marston, A P; Luong, Q Nguyen; Rivera-Ingraham, A; Roussel, H; Sousbie, T; Spinoglio, L; White, G J; Williams, J

    2013-01-01

    Pillars and globules are present in many high-mass star-forming regions, such as the Eagle nebula (M16) and the Rosette molecular cloud, and understanding their origin will help characterize triggered star formation. The formation mechanisms of these structures are still being debated. Recent numerical simulations have shown how pillars can arise from the collapse of the shell in on itself and how globules can be formed from the interplay of the turbulent molecular cloud and the ionization from massive stars. The goal here is to test this scenario through recent observations of two massive star-forming regions, M16 and Rosette. The column density structure of the interface between molecular clouds and H ii regions was characterized using column density maps obtained from far-infrared imaging of the Herschel HOBYS key programme. Then, the DisPerSe algorithm was used on these maps to detect the compressed layers around the ionized gas and pillars in different evolutionary states. Finally, their velocity structu...

  11. Ribosomal Protein P2 from apicomplexan parasite Toxoplasma gondii is intrinsically a molten globule.

    Science.gov (United States)

    Mishra, Pushpa; Choudhary, Sinjan; Hosur, Ramakrishna V

    2015-01-01

    Toxoplasma gondii is an apicomplexan parasite, which causes toxoplasmosis. Toxoplasma P2 (TgP2) is a ribosomal protein and exists as supramolecular assembly with other proteins in the ribosome. It is also shown that TgP2 is involved in some extra ribosomal functions. However, till date the protein has evaded structural characterization by any of the known techniques. In this background, we report here a systematic study using a variety of biophysical techniques and NMR, under different conditions of pH and temperature, and deduce that TgP2 consists of only helices and unstructured regions, is a monomer at low pH but forms multimers at higher pH, and has intrinsically a molten globule structure. The C-terminal half is flexible and the helices are concentrated in the N-terminal half of the chain. The dynamism inherent to the molten globule structure may have functional implications for its extra-ribosomal functions. which is contrast to that of human P2. PMID:25866913

  12. On urea's ability to stabilize the globule state of poly(N-isopropylacrylamide).

    Science.gov (United States)

    Pica, Andrea; Graziano, Giuseppe

    2016-06-01

    Experimental measurements have shown that urea decreases the temperature of the coil-to-globule collapse transition of poly(N-isopropylacrylamide), whereas tetramethylurea increases the collapse temperature [J. Am. Chem. Soc., 2009, 131, 9304]. These data indicate that urea is a stabilizing agent of the globule state in contrast to its denaturing action towards globular proteins. The effect of urea and tetramethylurea on the conformational stability of poly(N-isopropylacrylamide) is investigated by means of the theoretical approach developed to explain the existence of cold denaturation [Phys. Chem. Chem. Phys., 2010, 12, 14245; Phys. Chem. Chem. Phys., 2014, 16, 21755], and already used to rationalize the effect of sodium salts on the collapse temperature [Phys. Chem. Chem. Phys., 2015, 17, 27750]. It is necessary to take into account the delicate trade-off between the increase in the magnitude of the solvent-excluded volume effect caused by urea and tetramethylurea addition to water, and the increase in the magnitude of the energetic interactions among the poly(N-isopropylacrylamide) surface and water and co-solvent molecules. PMID:27171496

  13. [Study of circulating fatty globules by filtration of the serum in primary osteonecrosis of the femoral head].

    Science.gov (United States)

    Roux, H; Serratrice, G; Vovan, L; Savidan-Imbert

    1979-12-01

    The authors carried out in a group of 21 aseptic osteonecroses of the femoral head, a study of circulating fatty globules using a filtering technique on a millipore filter. 7 of these patients showed a normal lipid count, 10 had isolated increases of the prebetalipoproteins, 2 had a type IV hyperlipemia, 1 a type III hyperlipemia, and 1 a global hypolipemia. In all cases, no fatty globules were found. Decreases in the level of triglycerides and prebetalipoproteins were noted after filtering but the differences were not significant. These observations do not add support to the theory of fatty microembolism of aseptic osteonecrosis of the femoral head. PMID:531470

  14. Coil-globule transition for regular, random and specially designed copolymers: Monte Carlo simulation and self-consistent field theory

    NARCIS (Netherlands)

    Oever, J.M.P.; Leermakers, F.A.M.; Fleer, G.J.; Ivanov, V.A.; Shusharina, N.P.; Khokhlov, A.R.; Khalatur, P.G.

    2002-01-01

    The coil-globule transition has been studied for A-B copolymer chains both by means of lattice Monte Carlo (MC) simulations using bond fluctuation algorithm and by a numerical self-consistent-field (SCF) method. Copolymer chains of fixed length with A and B monomeric units with regular, random, and

  15. Identification of ABCA1 and ABCG1 in milk fat globules and mammary cells - Implications for milk cholesterol secretion

    DEFF Research Database (Denmark)

    Mani, O; Körner, M; Ontsouka, C E;

    2011-01-01

    test whether 1) ABCA1 and ABCG1 protein expression and subcellular localization in mammary epithelial cells (MEC) change during the pregnancy-lactation cycle, and 2) these 2 proteins were present in milk fat globules (MFG). Expression and localization in MEC were investigated in bovine MG tissues at...

  16. Comparative proteomics of milk fat globule membrane in goat colostrum and mature milk.

    Science.gov (United States)

    Lu, Jing; Liu, Lu; Pang, Xiaoyang; Zhang, Shuwen; Jia, Zhenhu; Ma, Changlu; Zhao, Lili; Lv, Jiaping

    2016-10-15

    As an important nutrient source in large area of world, the composition and nutritional value of goat milk are not well deliberated. Detailed annotation of protein composition is essential to address the physiological and nutritional value of goat milk. In the present study, 423 colostrum and mature goat milk fat globule membrane (MFGM) proteins were identified. The abundance of 189 proteins was significantly different between colostrums and mature milk MFGM. The acute phase proteins were higher in colostrums MFGM than those in mature milk MFGM which protected newborns at the beginning of life. Proteins related to synthesis and secretion were conserved through lactation to ensure the milk production. Of note, long term depression (LTD) proteins were observed in colostrum and mature milk MFGM. Milk LTD proteins could be potential biomarkers for diagnosis of lactation related depressive syndromes and should be taken into considerations of their effects on newborns. PMID:27173528

  17. Radiation doses obtained from 99mTc-labelled human milk fat globule monoclonal antibodies

    International Nuclear Information System (INIS)

    Human milk fat globule (HMFG) monoclonal antibodies labelled with 123I and 111In are used for the diagnosis of ovarian and breast cancer. Methods have been developed to label HMFG with 99mTc and this study reports on the subsequent radiation dose delivered. The 99mTc HMFG1 distribution was obtained in 5 normal female baboons up to 71 h after administration. The liver, kidneys, bladder and whole body were identified as source organs and total absorbed doses for the target organs were 0.054 (kidneys), 0.013 (liver), 0.140 (bladder), 0.010 (ovaria), 0.004 (bone marrow), 0.002 (thyroid), 0.003 (heart wall), 0.017 (uterus) and 0.005 mGy/MBq (whole body). The effective dose was 0.014 mSv/MBq. (author)

  18. Radiation doses obtained from 99mTc-labelled human milk fat globule monoclonal antibodies

    International Nuclear Information System (INIS)

    Human milk fat globule (HMFG) monoclonal antibodies labelled with 125I and 111In are used for the diagnosis of ovarian and breast cancer. Methods have been developed to label HMFG with 99mTc and this study reports on the subsequent radiation dose delivered. The 99mTc HMFG1 distribution was obtained in 5 normal female baboons up to 71 h after administration. The liver, kidneys, bladder and whole body were identified as source organs and total absorbed doses for the target organs were 0.054 (kidneys), 0.013 (liver), 0.140 (bladder), 0.010 (ovaria), 0.004 (bone marrow), 0.002 (thyroid), 0.003 (heart wall), 0.017 (uterus) and 0.005 mGy/MBq (whole body). The effective dose was 0.014 mSv/MBq. (author)

  19. Radiation-MHD simulations of pillars and globules in HII regions

    CERN Document Server

    Mackey, Jonathan

    2012-01-01

    Implicit and explicit raytracing-photoionisation algorithms have been implemented in the author's radiation-magnetohydrodynamics code. The algorithms are described briefly and their efficiency and parallel scaling are investigated. The implicit algorithm is more efficient for calculations where ionisation fronts have very supersonic velocities, and the explicit algorithm is favoured in the opposite limit because of its better parallel scaling. The implicit method is used to investigate the effects of initially uniform magnetic fields on the formation and evolution of dense pillars and cometary globules at the boundaries of HII regions. It is shown that for weak and medium field strengths an initially perpendicular field is swept into alignment with the pillar during its dynamical evolution, matching magnetic field observations of the`Pillars of Creation' in M16. A strong perpendicular magnetic field remains in its initial configuration and also confines the photoevaporation flow into a bar-shaped, dense, ioni...

  20. Radiation-MHD Simulations of Pillars and Globules in HII Regions

    Science.gov (United States)

    Mackey, J.

    2012-07-01

    Implicit and explicit raytracing-photoionisation algorithms have been implemented in the author's radiation-magnetohydrodynamics code. The algorithms are described briefly and their efficiency and parallel scaling are investigated. The implicit algorithm is more efficient for calculations where ionisation fronts have very supersonic velocities, and the explicit algorithm is favoured in the opposite limit because of its better parallel scaling. The implicit method is used to investigate the effects of initially uniform magnetic fields on the formation and evolution of dense pillars and cometary globules at the boundaries of HII regions. It is shown that for weak and medium field strengths an initially perpendicular field is swept into alignment with the pillar during its dynamical evolution, matching magnetic field observations of the ‘Pillars of Creation’ in M16. A strong perpendicular magnetic field remains in its initial configuration and also confines the photoevaporation flow into a bar-shaped, dense, ionised ribbon which partially shields the ionisation front.

  1. ADVANCED SULFUR CONTROL CONCEPTS

    Energy Technology Data Exchange (ETDEWEB)

    Apostolos A. Nikolopoulos; Santosh K. Gangwal; William J. McMichael; Jeffrey W. Portzer

    2003-01-01

    Conventional sulfur removal in integrated gasification combined cycle (IGCC) power plants involves numerous steps: COS (carbonyl sulfide) hydrolysis, amine scrubbing/regeneration, Claus process, and tail-gas treatment. Advanced sulfur removal in IGCC systems involves typically the use of zinc oxide-based sorbents. The sulfides sorbent is regenerated using dilute air to produce a dilute SO{sub 2} (sulfur dioxide) tail gas. Under previous contracts the highly effective first generation Direct Sulfur Recovery Process (DSRP) for catalytic reduction of this SO{sub 2} tail gas to elemental sulfur was developed. This process is currently undergoing field-testing. In this project, advanced concepts were evaluated to reduce the number of unit operations in sulfur removal and recovery. Substantial effort was directed towards developing sorbents that could be directly regenerated to elemental sulfur in an Advanced Hot Gas Process (AHGP). Development of this process has been described in detail in Appendices A-F. RTI began the development of the Single-step Sulfur Recovery Process (SSRP) to eliminate the use of sorbents and multiple reactors in sulfur removal and recovery. This process showed promising preliminary results and thus further process development of AHGP was abandoned in favor of SSRP. The SSRP is a direct Claus process that consists of injecting SO{sub 2} directly into the quenched coal gas from a coal gasifier, and reacting the H{sub 2}S-SO{sub 2} mixture over a selective catalyst to both remove and recover sulfur in a single step. The process is conducted at gasifier pressure and 125 to 160 C. The proposed commercial embodiment of the SSRP involves a liquid phase of molten sulfur with dispersed catalyst in a slurry bubble-column reactor (SBCR).

  2. Sulfur solubility in reduced mafic silicate melts: Implications for the speciation and distribution of sulfur on Mercury

    Science.gov (United States)

    Namur, Olivier; Charlier, Bernard; Holtz, Francois; Cartier, Camille; McCammon, Catherine

    2016-08-01

    Chemical data from the MESSENGER spacecraft revealed that surface rocks on Mercury are unusually enriched in sulfur compared to samples from other terrestrial planets. In order to understand the speciation and distribution of sulfur on Mercury, we performed high temperature (1200-1750 °C), low- to high-pressure (1 bar to 4 GPa) experiments on compositions representative of Mercurian lavas and on the silicate composition of an enstatite chondrite. We equilibrated silicate melts with sulfide and metallic melts under highly reducing conditions (IW-1.5 to IW-9.4; IW = iron-wüstite oxygen fugacity buffer). Under these oxygen fugacity conditions, sulfur dissolves in the silicate melt as S2- and forms complexes with Fe2+, Mg2+ and Ca2+. The sulfur concentration in silicate melts at sulfide saturation (SCSS) increases with increasing reducing conditions (from 10 wt.% S at IW-8) and with increasing temperature. Metallic melts have a low sulfur content which decreases from 3 wt.% at IW-2 to 0 wt.% at IW-9. We developed an empirical parameterization to predict SCSS in Mercurian magmas as a function of oxygen fugacity (fO2), temperature, pressure and silicate melt composition. SCSS being not strictly a redox reaction, our expression is fully valid for magmatic systems containing a metal phase. Using physical constraints of the Mercurian mantle and magmas as well as our experimental results, we suggest that basalts on Mercury were free of sulfide globules when they erupted. The high sulfur contents revealed by MESSENGER result from the high sulfur solubility in silicate melt at reducing conditions. We make the realistic assumption that the oxygen fugacity of mantle rocks was set during equilibration of the magma ocean with the core and/or that the mantle contains a minor metal phase and combine our parameterization of SCSS with chemical data from MESSENGER to constrain the oxygen fugacity of Mercury's interior to IW- 5.4 ± 0.4. We also calculate that the mantle of Mercury

  3. The protein and lipid composition of the membrane of milk fat globules depends on their size.

    Science.gov (United States)

    Lu, Jing; Argov-Argaman, Nurit; Anggrek, Jeni; Boeren, Sjef; van Hooijdonk, Toon; Vervoort, Jacques; Hettinga, Kasper Arthur

    2016-06-01

    In bovine milk, fat globules (MFG) have a heterogeneous size distribution with diameters ranging from 0.1 to 15 µm. Although efforts have been made to explain differences in lipid composition, little is known about the protein composition of MFG membranes (MFGM) in different sizes of MFG. In this study, protein and lipid analyses were combined to study MFG formation and secretion. Two different sized MFG fractions (7.6±0.9 µm and 3.3±1.2 µm) were obtained by centrifugation. The protein composition of MFGM in the large and small MFG fractions was compared using mass-spectrometry-based proteomics techniques. The lipid composition and fatty acid composition of MFG was determined using HPLC-evaporative light-scattering detector and gas chromatography, respectively. Two frequently studied proteins in lipid droplet biogenesis, perilipin-2 and TIP47, were increased in the large and small MFG fractions, respectively. In the large MFG fraction, besides perilipin-2, cytoplasmic vesicle proteins (heat shock proteins, 14-3-3 proteins, and Rabs), microfilaments and intermediate filament-related proteins (actin and vimentin), host defense proteins (cathelicidins), and phosphatidylinositol were higher in concentration. On the other hand, cholesterol synthesis enzymes [lanosterol synthase and sterol-4-α-carboxylate 3-dehydrogenase (decarboxylating)], cholesterol, unsaturated fatty acids, and phosphatidylethanolamine were, besides TIP47, higher in concentration in the small MFG fraction. These results suggest that vesicle proteins, microfilaments and intermediate filaments, cholesterol, and specific phospholipids play an important role in lipid droplet growth, secretion, or both. The observations from this study clearly demonstrated the difference in protein and lipid composition between small and large MFG fractions. Studying the role of these components in more detail in future experiments may lead to a better understanding of fat globule formation and secretion. PMID

  4. Nanostructured sulfur cathodes

    KAUST Repository

    Yang, Yuan

    2013-01-01

    Rechargeable Li/S batteries have attracted significant attention lately due to their high specific energy and low cost. They are promising candidates for applications, including portable electronics, electric vehicles and grid-level energy storage. However, poor cycle life and low power capability are major technical obstacles. Various nanostructured sulfur cathodes have been developed to address these issues, as they provide greater resistance to pulverization, faster reaction kinetics and better trapping of soluble polysulfides. In this review, recent developments on nanostructured sulfur cathodes and mechanisms behind their operation are presented and discussed. Moreover, progress on novel characterization of sulfur cathodes is also summarized, as it has deepened the understanding of sulfur cathodes and will guide further rational design of sulfur electrodes. © 2013 The Royal Society of Chemistry.

  5. Globules and pillars in Cygnus X. I. Herschel far-infrared imaging of the Cygnus OB2 environment

    Science.gov (United States)

    Schneider, N.; Bontemps, S.; Motte, F.; Blazere, A.; André, Ph.; Anderson, L. D.; Arzoumanian, D.; Comerón, F.; Didelon, P.; Di Francesco, J.; Duarte-Cabral, A.; Guarcello, M. G.; Hennemann, M.; Hill, T.; Könyves, V.; Marston, A.; Minier, V.; Rygl, K. L. J.; Röllig, M.; Roy, A.; Spinoglio, L.; Tremblin, P.; White, G. J.; Wright, N. J.

    2016-06-01

    The radiative feedback of massive stars on molecular clouds creates pillars, globules and other features at the interface between the H II region and molecular cloud. Optical and near-infrared observations from the ground as well as with the Hubble or Spitzer satellites have revealed numerous examples of such cloud structures. We present here Herschel far-infrared observations between 70 μm and 500 μm of the immediate environment of the rich Cygnus OB2 association, performed within the Herschel imaging survey of OB Young Stellar objects (HOBYS) program. All of the observed irradiated structures were detected based on their appearance at 70 μm, and have been classified as pillars, globules, evaporating gasous globules (EGGs), proplyd-like objects, and condensations. From the 70 μm and 160 μm flux maps, we derive the local far-ultraviolet (FUV) field on the photon dominated surfaces. In parallel, we use a census of the O-stars to estimate the overall FUV-field, that is 103-104 G0 (Habing field) close to the central OB cluster (within 10 pc) and decreases down to a few tens G0, in a distance of 50 pc. From a spectral energy distribution (SED) fit to the four longest Herschel wavelengths, we determine column density and temperature maps and derive masses, volume densities and surface densities for these structures. We find that the morphological classification corresponds to distinct physical properties. Pillars and globules are massive (~500 M⊙) and large (equivalent radius r ~ 0.6 pc) structures, corresponding to what is defined as "clumps" for molecular clouds. EGGs and proplyd-likeobjects are smaller (r ~ 0.1 and 0.2 pc) and less massive (~10 and ~30 M⊙). Cloud condensations are small (~0.1 pc), have an average mass of 35 M⊙, are dense (~6 × 104 cm-3), and can thus be described as molecular cloud "cores". All pillars and globules are oriented toward the Cyg OB2 association center and have the longest estimated photoevaporation lifetimes, a few million

  6. Sulfuric Acid on Europa

    Science.gov (United States)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain. This image is based on data gathered by Galileo's near infrared mapping spectrometer.Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks. Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  7. Modélisation numérique des formes d’équilibre d’un globule rouge

    OpenAIRE

    Simeoni, Matthieu Martin Jean-Andre

    2013-01-01

    Nous nous proposons dans cette étude de valider le modèle introduit par Canham et Helfrich afin de décrire les formes d’équilibre statique d’un globule rouge. Selon ce modèle, la forme du globule rouge est solution d’un problème d’optimisation sous contrainte: minimisation de l’énergie de Canham Helfrich pour un volume et une aire fixés. Après avoir formaliser le problème matématiquement, nous dérivons la conditionn d’optimalité menant à une équation différentielle ordinaire non linéaire véri...

  8. Hydrolysis of human milk fat globules by pancreatic lipase: role of colipase, phospholipase A2, and bile salts.

    OpenAIRE

    Bläckberg, L; Hernell, O; Olivecrona, T

    1981-01-01

    Human milk fat globules were used to explore how dietary triglycerides are hydrolyzed by pancreatic lipase. These triglycerides were hydrolyzed very slowly by lipase alone as if the surface layer of proteins and phospholipids impeded the action of the enzyme. The inhibition of lipase activity could be overcome by addition either of colipase or of pancreatic phospholipase A2. Colipase enhanced triglyceride hydrolysis in a dose-dependent manner whether bile salts were present or not. Bile salts...

  9. Hydrophobic photolabeling as a new method for structural characterization of molten globule and related protein folding intermediates.

    OpenAIRE

    D'Silva, P. R.; Lala, A. K.

    1999-01-01

    Recent advances in attempts to unravel the protein folding mechanism have indicated the need to identify the folding intermediates. Despite their transient nature, in a number of cases it has been possible to detect and characterize some of the equilibrium intermediates, for example, the molten globule (MG) state. The key features of the MG state are retention of substantial secondary structure of the native state, considerable loss of tertiary structure leading to increased hydrophobic expos...

  10. Looking into the hearts of Bok globules: MM and submm continuum images of isolated star-forming cores

    OpenAIRE

    Launhardt, R.; Nutter, D.; Ward-Thompson, D.; Bourke, T. L.; Henning, Th.; Khanzadyan, T.; Schmalzl, M.; Wolf, S; Zylka, R.

    2010-01-01

    We present the results of a comprehensive infrared, submillimetre, and millimetre continuum emission study of isolated low-mass star-forming cores in 32 Bok globules, with the aim to investigate the process of star formation in these regions. The submillimetre and millimetre dust continuum emission maps together with the spectral energy distributions are used to model and derive the physical properties of the star-forming cores, such as luminosities, sizes, masses, densities, etc. Comparisons...

  11. Hydrolysis of milk fat globules by pancreatic lipase. Role of colipase, phospholipase A2, and bile salts.

    OpenAIRE

    Borgström, B.; Erlanson-Albertsson, C

    1982-01-01

    Human milk fat globules require colipase to be hydrolyzed by pancreatic lipase in the presence of bile salts. This is contrary to a recent report in this Journal (J. Clin. Invest. 67: 1748-1752.) according to which inhibition of lipase by bile salt could be overcome by the addition of colipase or phospholipase A2. This latter finding is shown to be due to contamination of commercially available pancreatic phospholipase A2 by colipase.

  12. Study of the variables which influence the impregnation of globules, compressed tablets and tablet triturates used in homeopathy

    OpenAIRE

    Fernanda Santos de Souza; Mayara Marin Pirolli; Eliana Elisabeth Diehl; Diva Sonaglio

    2012-01-01

    Globules, compressed tablets and tablet triturates are solid dosage forms used in homeopathy. Divergences can be noted between the preparation techniques described in official compendiums as well as those applied in homeopathic pharmacies. The difficulty associated with standardization of the impregnation of these dosage forms occurs due to the lack of detail provided for the techniques in the literature, leaving it up to each pharmacy to decide on the exact method of preparation. The objecti...

  13. Differences in the Pathways of Proteins Unfolding Induced by Urea and Guanidine Hydrochloride: Molten Globule State and Aggregates

    OpenAIRE

    Povarova, Olga I.; Kuznetsova, Irina M.; Turoverov, Konstantin K.

    2010-01-01

    It was shown that at low concentrations guanidine hydrochloride (GdnHCl) can cause aggregation of proteins in partially folded state and that fluorescent dye 1-anilinonaphthalene-8-sulfonic acid (ANS) binds with these aggregates rather than with hydrophobic clusters on the surface of protein in molten globule state. That is why the increase in ANS fluorescence intensity is often recorded in the pathway of protein denaturation by GdnHCl, but not by urea. So what was previously believed to be t...

  14. Separation of sulfur isotopes

    Science.gov (United States)

    DeWitt, Robert; Jepson, Bernhart E.; Schwind, Roger A.

    1976-06-22

    Sulfur isotopes are continuously separated and enriched using a closed loop reflux system wherein sulfur dioxide (SO.sub.2) is reacted with sodium hydroxide (NaOH) or the like to form sodium hydrogen sulfite (NaHSO.sub.3). Heavier sulfur isotopes are preferentially attracted to the NaHSO.sub.3, and subsequently reacted with sulfuric acid (H.sub.2 SO.sub.4) forming sodium hydrogen sulfate (NaHSO.sub.4) and SO.sub.2 gas which contains increased concentrations of the heavier sulfur isotopes. This heavy isotope enriched SO.sub.2 gas is subsequently separated and the NaHSO.sub.4 is reacted with NaOH to form sodium sulfate (Na.sub.2 SO.sub.4) which is subsequently decomposed in an electrodialysis unit to form the NaOH and H.sub.2 SO.sub.4 components which are used in the aforesaid reactions thereby effecting sulfur isotope separation and enrichment without objectionable loss of feed materials.

  15. Globules and Pillars in Cygnus X I. Herschel Far-infrared imaging of the Cyg OB2 environment

    CERN Document Server

    Schneider, N; Motte, F; Blazere, A; Andre, Ph; Anderson, L D; Arzoumanian, D; Comeron, F; Didelon, P; Di Francesco, J; Duarte-Cabral, A; Guarcello, M G; Hennemann, M; Hill, T; Konyves, V; Marston, A; Minier, V; Rygl, K L J; Roellig, M; Roy, A; Spinoglio, L; Tremblin, P; White, G J; Wright, N J

    2016-01-01

    The radiative feedback of massive stars on molecular clouds creates pillars, globules and other features at the interface between the HII region and molecular cloud. We present here Herschel observations between 70 and 500 micron of the immediate environment of the Cygnus OB2 association, performed within the HOBYS program. All structures were detected based on their appearance at 70 micron, and have been classified as pillars, globules, evaporating gasous globules (EGGs), proplyd-like objects, and condensations. From the 70 and 160 micron flux maps, we derive the local FUV field on the PDR surfaces. In parallel, we use a census of the O-stars to estimate the overall FUV-field, that is 10^3-10^4 G_0 close to the central OB cluster (within 10 pc) and decreases down to a few tens G_0, in a distance of 50 pc. From a SED fit to the four longest Herschel wavelengths, we determine column density and temperature maps and derive masses, volume densities and surface densities for these structures. We find that the mor...

  16. Intramedullary and extramedullary fat globules on magnetic resonance imaging as a diagnostic sign for osteomyelitis

    International Nuclear Information System (INIS)

    We retrospectively studied the frequency of persistent foci of fat signal on magnetic resonance (MR) imaging in osteomyelitis to assess its frequency, cause and diagnostic value. The radiographs and MR scans of 100 patients with a final diagnosis of osteomyelitis referred to a specialist orthopaedic oncology service with the presumptive diagnosis of a bone tumour were reviewed. The MR signal and morphological characteristics were recorded with particular attention to the presence of persistent fat signal within the infected area, which was classified as diffuse or focal. Seventeen cases were classified on radiographic grounds as acute, 63 as subacute and 20 as chronic osteomyelitis. In the acute group 12 (70%) showed replacement of the marrow with fluid containing residual fatty signal, diffuse in seven and focal in five cases. Two cases showed predominantly fatty marrow with very early marrow oedema and three cases (18%) showed replacement of marrow fat with fluid and no residual fatty foci. None of the subacute group showed foci of fatty signal and two cases of inactive sclerosing osyeomyelitis in the chronic group showed restoration of normal marrow. Persistent fatty signal within the bone as well as soft tissues on MR imaging is a frequent finding in acute osteomyelitis. Radiological-pathological correlation suggests that the increasing intramedullary pressure leads to septic necrosis with death of the lipocytes and release of free fatty globules. This characteristic, but not pathognomonic, MR finding supports the diagnosis of osteomyelitis and may help to exclude the presence of a tumour. (orig.)

  17. Phagocytosis mechanism of apoptotic granulosa cells regulated by milk-fat globule-EGF factor 8.

    Science.gov (United States)

    Naka, Mayumi; Kusakabe, Ken; Takeshita, Ai; Nakagawa, Hiroshi; Ito, Yuko; Shibata, Masa-Aki; Otsuki, Yoshinori

    2009-09-01

    In the process of ovary sexual maturation, most immature ovarian follicles degrade into atretic follicles accompanied by apoptosis in granulosa cells. Macrophages can recognize apoptotic cells through specific binding with phosphatidylserine (PS), exposed on the surface of apoptotic cells, which is mediated by milk-fat globule-EGF factor 8 (MFG-E8). In the present research, we examined the involvement of the MFG-E8-dependent phagocytosis system in the atretic follicles of developing mouse ovaries. The number of atretic follicles and DNA-fragmented granulosa cells significantly increased in B6C3F1 mice during 2 to 6 weeks. Chromatin-condensed granulosa cells were engulfed by macrophages, which existed in the stroma or atretic follicles, or by neighboring normal granulosa cells. MFG-E8 mRNA increased in ovaries during 2 to 6 weeks, and immunoreactivity of MFG-E8 was detected at the surface of apoptotic cells existing around the antrum. Immunoelectron microscopic study revealed MFG-E8-positive signals on the membrane of apoptotic cells near macrophages, but apoptotic cells engulfed by neighboring granulosa cells showed few signals. Anti-Fas antibody elevated the annexin-V-positive reaction in isolated granulosa cells from 3-week-old mouse ovaries. MFG-E8 seems to act on the phagocytosis of apoptotic granulosa cells via macrophages and contribute to the regression process of atretic follicles. PMID:19784740

  18. Radiation-MHD models of elephant trunks and globules in H II regions

    CERN Document Server

    Mackey, Jonathan

    2011-01-01

    We study the formation and evolution of pillars of dense gas, known as elephant trunks, at the boundaries of H II regions, formed by shadowing of ionising radiation by dense clumps. The effects of magnetic fields on this process are investigated using 3D radiation-magnetohydrodynamics simulations. For a simulation in which an initially uniform magnetic field of strength |B|=50 uG is oriented perpendicular to the radiation propagation direction, the field is swept into alignment with the pillar during its dynamical evolution, in agreement with observations of the "Pillars of Creation" in M16, and of some cometary globules. This effect is significantly enhanced when the simulation is re-run with a weaker field of 18 uG. A stronger field with |B|=160 uG is sufficient to prevent this evolution completely, also significantly affecting the photoionisation process. Using a larger simulation domain it is seen that the pillar formation models studied in Mackey & Lim (2010) ultimately evolve to cometary structures ...

  19. Development of a radioimmunoassay for human milk-fat-globule membrane glycoprotein

    International Nuclear Information System (INIS)

    A radioimmunoassay (RIA) was developed for the quantitative measurement of a glycoprotein which was purified from human milk-fat-globule membrane (MFGM) and termed MFGM-pg 70. The assay with a sensitivity of detecting 30 ng of MFGM-pg 70/ml was employed to quantitate the levels of MFGM-gp 70 shed in supernatants from primary cultures of normal and malignant human breast cells and from various established cell lines of human mammary including myoepithelial and fibroblast and non-mammary malignant epithelial cells. The RIA for MFGM-gp 70 showed that the amount of antigen shed was much higher in supernatants from normal mammary epithelial cells compared with their malignant counterparts grown in primary culture and with those from established cell lines of malignant mammary epithelial cells. The levels of MFGM-pg 70 in spent media were unaffected by the lactogenic hormones such as prolactin or insulin. The RIA for MFGM-gp 70 provides a sensitive and quantitative means to in vitro study the synthesis of a membrane glycoprotein from human mammary epithelium. (Auth.)

  20. Study of magnetic field geometry and extinction in Bok globule CB130

    CERN Document Server

    Chakraborty, A

    2016-01-01

    We trace the peripheral magnetic field structure of Bok globule CB130, by estimating the linear polarization of its field stars in the R band. The magnetic field orientation sampled by these stars, aligned on average among themselves and the polarization produced within the cloud has a different direction from that of Galactic plane with an offset of 53$^\\circ$. The offset between minor axis and the mean magnetic field of CB130 is found to be 80$^\\circ$. The estimated strength of the magnetic field in the plane-of-the-sky is $\\sim$ 116$\\pm$19 $\\mu$G. We constructed the visual extinction map using Near Infrared Color Excess (NICE) method to see the dust distribution around CB130. Contours of Herschel {Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA} SPIRE 500$\\mu$m dust continuum emission maps of this cloud is over-plotted on the visual extinction map which shows the regions having higher optical ...

  1. Aircraft exhaust sulfur emissions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Anderson, M.R.; Miake-Lye, R.C.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A.A.; Buriko, Y.I. [Scientific Research Center `Ecolen`, Moscow (Russian Federation)

    1997-12-31

    The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

  2. Sulfur activation in Hiroshima

    International Nuclear Information System (INIS)

    In 1979, we attempted to establish the validity of source terms for the Hiroshima and Nagasaki bombs using experimental data on sulfur activation. Close agreement was observed between measured and calculated values for test firings of Nagasaki-type bombs. The calculated values were based on source terms developed by W.E. Preeg at the Los Alamos National Laboratory (LANL). A discrepancy was found, however, when we compared calculated values for the two bombs because a 1956 report by R.R. Wilson stated that sulfur acitvation by fast neutrons in Hiroshima was approximately three times greater than in Nagasaki. Our calculations based on Preeg's source-term data predicted about equal sulfur activation in the two cities

  3. Molten globule of hemoglobin proceeds into aggregates and advanced glycated end products.

    Directory of Open Access Journals (Sweden)

    Afshin Iram

    Full Text Available Conformational alterations of bovine hemoglobin (Hb upon sequential addition of glyoxal over a range of 0-90% v/v were investigated. At 20% v/v glyoxal, molten globule (MG state of Hb was observed by altered tryptophan fluorescence, high ANS binding, existence of intact heme, native-like secondary structure as depicted by far-UV circular dichroism (CD and ATR-FTIR spectra as well as loss in tertiary structure as confirmed by near-UV CD spectra. In addition, size exclusion chromatography analysis depicted that MG state at 20% v/v glyoxal corresponded to expanded pre-dissociated dimers. Aggregates of Hb were detected at 70% v/v glyoxal. These aggregates of Hb had altered tryptophan environment, low ANS binding, exposed heme, increased β-sheet secondary structure, loss in tertiary structure, enhanced thioflavin T (ThT fluorescence and red shifted Congo Red (CR absorbance. On incubating Hb with 30% v/v glyoxal for 0-20 days, advanced glycation end products (AGEs were detected on day 20. These AGEs were characterised by enhanced tryptophan fluorescence at 450 nm, exposure of heme, increase in intermolecular β-sheets, enhanced ThT fluorescence and red shift in CR absorbance. Comet assay revealed aggregates and AGEs to be genotoxic in nature. Scanning electron microscopy confirmed the amorphous structure of aggregates and branched fibrils of AGEs. The transformation of α-helix to β-sheet usually alters the normal protein to amyloidogenic resulting in a variety of protein conformational disorders such as diabetes, prion and Huntington's.

  4. Milk fat globule is an alternative to mammary epithelial cells for gene expression analysis in buffalo.

    Science.gov (United States)

    Chen, Qiuming; Wu, Yanjun; Zhang, Mingyuan; Xu, Wenwen; Guo, Xiaoping; Yan, Xueyu; Deng, Haiying; Jiang, Qinyang; Yang, Xiurong; Lan, Ganqiu; Guo, Yafen; Qin, Guangsheng; Jiang, Hesheng

    2016-05-01

    Owing to the difficulty in obtaining mammary gland tissue from lactating animals, it is difficult to test the expression levels of genes in mammary gland. The aim of the current study was to identify if milk fat globule (MFG) in buffalo milk was an alternative to mammary gland (MG) and milk somatic cell (MSC) for gene expression analysis. Six buffalos in late lactation were selected to collect MFG and MSC, and then MG was obtained by surgery. MFG was stained with acridine orange to successfully visualise RNA and several cytoplasmic crescents in MFG. The total RNA in MFG was successfully isolated and the integrity was assessed by agarose gel electrophoresis. We analysed the cellular components in MFG, MG and MSC through testing the expression of cell-specific genes by qRT-PCR. The results showed that adipocyte-specific gene (AdipoQ) and leucocyte-specific genes (CD43, CSF1 and IL1α) in MFG were not detected, whereas epithelial cell marker genes (Keratin 8 and Keratin 18) in MFG were higher than in MSC and lower than in MG, fibroblast marker gene (vimentin) in MFG was significantly lower than in MG and MSC, milk protein genes (LALBA, BLG and CSN2) and milk fat synthesis-related genes (ACC, BTN1A1, FABP3 and FAS) in MFG were higher than in MG and MSC. In conclusion, the total RNA in MFG mainly derives from mammary epithelial cells and can be used to study the functional gene expression of mammary epithelial cells. PMID:27032540

  5. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to capture greater than 90 percent of sulfur gases evolved during thermal treatment of lunar soils....

  6. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to recover sulfur compounds from lunar soil using sorbents derived primarily from in-situ resources....

  7. The effects of low-molecular-weight emulsifiers in O/W-emulsions on microviscosity of non-solidified oil in fat globules and the mobility of emulsifiers at the globule surfaces

    DEFF Research Database (Denmark)

    Munk, Merete B.; Erichsen, Henriette Rifbjerg; Andersen, Mogens Larsen

    2014-01-01

    Electron Spin Resonance spectroscopy (ESR) was used to measure the mobility of the spin probe TEMPO in O/W-emulsions. This allowed determination of temperature-dependent microviscosity of the liquid fraction in lipid globules. Six hydrogenated palm kernel oil (HPKO) based emulsions containing...... caseinate and different combinations of lactic acid ester of monoglyceride (LACTEM), unsaturated monoglycerides (GMU) or saturated monoglyceride (GMS) were studied. The non-solidified oil in emulsions made with LACTEM. +. GMU had a high microviscosity, whereas the emulsion made with GMS had a low...

  8. Sulfur Biogeochemistry of an Oil Sands Composite Tailings Deposit

    Directory of Open Access Journals (Sweden)

    Lesley A Warren

    2016-02-01

    Full Text Available Composite tailings (CT, an engineered, alkaline, saline mixture of oil sands tailings (FFT, processed sand and gypsum (CaSO4; 1 kg CaSO4 per m3 FFT are used as a dry reclamation strategy in the Alberta Oil Sands Region (AOSR. It is estimated that 9.6 x 108 m3 of CT are either in, or awaiting emplacement in surface pits within the AOSR, highlighting their potential global importance in sulfur cycling. Here, in the first CT sulfur biogeochemistry investigation, integrated geochemical, pyrosequencing and lipid analyses identified high aqueous concentrations of ∑H2S (> 300 uM and highly altered sulfur compounds composition; low cell biomass (3.3 x106 to 6.0 x106 cells g-1 and modest bacterial diversity (H’ range between 1.4 to 1.9 across 5 depths spanning 34 meters of an in situ CT deposit. Pyrosequence results identified a total of 29,719 bacterial 16S rRNA gene sequences, representing 131 OTUs spanning19 phyla including 7 candidate divisions, not reported in oil sands tailings pond studies to date. Legacy FFT common phyla, notably, gamma and beta Proteobacteria, Firmicutes, Actinobacteria and Chloroflexi were represented. However, overall CT microbial diversity and PLFA values were low relative to other contexts. The identified known sulfate/sulfur reducing bacteria constituted at most 2% of the abundance; however, over 90% of the 131 OTUs identified are capable of sulfur metabolism. While PCR biases caution against overinterpretation of pyrosequence surveys, bacterial sequence results identified here, align with phospholipid fatty acid (PLFA and geochemical results. The highest bacterial diversities were associated with the depth of highest porewater [∑H2S] (22-24 m and joint porewater co-occurrence of Fe2+ and ∑H2S (6-8 m. Three distinct bacterial community structure depths corresponded to CT porewater regions of (1 shallow evident Fe(II (< 6 m, (2 co-occurring Fe(II and ∑H2S (6-8 m and (3 extensive ∑H2S (6-34 m (UniFrac. Candidate

  9. 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 ...

  10. 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, ...

  11. Prostatitis - bacterial

    Science.gov (United States)

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

  12. Bacterial Conjunctivitis

    OpenAIRE

    Köhle, Ülkü; Kükner, Şahap

    2003-01-01

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

  13. Accidents with sulfuric acid

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2006-01-01

    Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

  14. Sulfur Dioxide Pollution Monitor.

    Science.gov (United States)

    National Bureau of Standards (DOC), Washington, DC.

    The sulfur dioxide pollution monitor described in this document is a government-owed invention that is available for licensing. The background of the invention is outlined, and drawings of the monitor together with a detailed description of its function are provided. A sample stream of air, smokestack gas or the like is flowed through a…

  15. Characterization of Sulfur Compounds in MTBE

    OpenAIRE

    Mingqing Wu; Chunyan Chang; Tao Li; Jian Zhou; Liping Zhao

    2015-01-01

    A study is carried out on chemical constitution of sulfur compounds in MTBE and their formation mechanisms. These sulfur compounds are classified into three types: common sulfur compounds, newly formed sulfur compounds, and high boiling sulfur compounds. Common sulfur compounds which include mercaptans, low molecule sulfides and disulfides, are directly from C4, one of the stocks for production of MTBE. The newly formed sulfur compounds, with one sulfur atom and five or more total carbon atom...

  16. SULFUR POLYMER ENCAPSULATION

    International Nuclear Information System (INIS)

    Sulfur polymer cement (SPC) is a thermoplastic polymer consisting of 95 wt% elemental sulfur and 5 wt% organic modifiers to enhance long-term durability. SPC was originally developed by the U.S. Bureau of Mines as an alternative to hydraulic cement for construction applications. Previous attempts to use elemental sulfur as a construction material in the chemical industry failed due to premature degradation. These failures were caused by the internal stresses that result from changes in crystalline structure upon cooling of the material. By reacting elemental sulfur with organic polymers, the Bureau of Mines developed a product that successfully suppresses the solid phase transition and significantly improves the stability of the product. SPC, originally named modified sulfur cement, is produced from readily available, inexpensive waste sulfur derived from desulfurization of both flue gases and petroleum. The commercial production of SPC is licensed in the United States by Martin Resources (Odessa, Texas) and is marketed under the trade name Chement 2000. It is sold in granular form and is relatively inexpensive ((approx)$0.10 to 0.12/lb). Application of SPC for the treatment of radioactive, hazardous, and mixed wastes was initially developed and patented by Brookhaven National Laboratory (BNL) in the mid-1980s (Kalb and Colombo, 1985; Colombo et al., 1997). The process was subsequently investigated by the Commission of the European Communities (Van Dalen and Rijpkema, 1989), Idaho National Engineering Laboratory (Darnell, 1991), and Oak Ridge National Laboratory (Mattus and Mattus, 1994). SPC has been used primarily in microencapsulation applications but can also be used for macroencapsulation of waste. SPC microencapsulation has been demonstrated to be an effective treatment for a wide variety of wastes, including incinerator hearth and fly ash; aqueous concentrates such as sulfates, borates, and chlorides; blowdown solutions; soils; and sludges. It is not

  17. Body measures and milk production, milk fat globules granulometry and milk fatty acid content in Cabannina cattle breed

    Directory of Open Access Journals (Sweden)

    Ricardo Communod

    2013-03-01

    Full Text Available Aim of the study was to achieve scientific information about body measures and milk production of Cabannina cattle, a local breed reared in northern Italy. Fourteen body measures and five morphologic indexes were recorded from 86 heads enrolled in the herd book. Low differences between males and females of the same age-class were shown. Body measures were generally greater than those reported in previous studies, probably due to recent crosses. With reference to milk production, 991 test-day records from 128 lactations of 59 cows were analysed. Average milk daily production was 8 kg/d in 1st lactation to 10.61 in 3rd (P<0.05; the parameters of the Wood equation draw atypical curves with the exception of curves from spring calving cows. Only 74.5% of lactations with an adjusted R2 >0.75 showed a standard curve, with low persistence (7.7%, high value of d at peak (103 d and peak production of 20.18 kg of milk. Moreover, 100 milk samples (40 to 220 d of lactation were submitted to a granulometric survey by laser scatter technique in order to evaluate the dimensions of fat globules; then milk fat was analyzed by gas chromatography, and desaturase indexes were determined. Cabannina cows showed small fat globules with high specific surface. Furthermore mean diameter of milk fat globules decreased during lactation then rose. Milk fat contained high levels of cis-MUFA, and high desaturase indexes. In conclusion, the low size of Cabannina cattle orients for a limited meat production. Instead milk production has a higher economic potential, aimed at cheese production and human nutrition.

  18. Characterization of molten globule PopB in absence and presence of its chaperone PcrH.

    Science.gov (United States)

    Dey, Supratim; Basu, Abhishek; Datta, Saumen

    2012-06-01

    The TTSS encoding "translocator operon" of Pseudomonas aeruginosa consists of a major translocator protein PopB, minor translocator protein PopD and their cognate chaperone PcrH. Far-UV CD spectra and secondary structure prediction servers predict an α-helical model for PopB, PcrH and PopB-PcrH complex. PopB itself forms a single species of higher order oligomer (15 mer) as seen from AUC, but in complex with PcrH, both monomeric (1:1) and oligomeric form exist. PopB has large solvent-exposed hydrophobic patches and exists as an unordered molten globule in its native state, but on forming complex with PcrH it gets transformed into an ordered molten globule. Tryptophan fluorescence spectrum indicates that PopB interacts with the first TPR region of dimeric PcrH to form a stable PopB-PcrH complex that has a partial rigid structure with a large hydrodynamic radius and few tertiary contacts. The pH-dependent studies of PopB, PcrH and complex by ANS fluorescence, urea induced unfolding and thermal denaturation experiments prove that PcrH not only provides structural support to the ordered molten globule PopB in complex but also undergoes conformational change to assist PopB to pass through the needle complex of TTSS and form pores in the host cell membrane. ITC experiments show a strong affinity (K(d) ~ 0.37 μM) of PopB for PcrH at pH 7.8, which reduces to ~0.68 μM at pH 5.8. PcrH also loses its rigid tertiary structure at pH 5 and attains a molten globule conformation. This indicates that the decrease in pH releases PopB molecules and thus triggers the TTSS activation mechanism for the formation of a functional translocon. PMID:22585368

  19. Photo-evaporation of Globulettes : Numerical hydrodynamic studies of photo-evaporating low-mass globules in the Rosette Nebula

    OpenAIRE

    Kuutmann, Andrej

    2007-01-01

    In this work, the long-term evolution of globulettes, low-mass globules found in H II regions, is studied through numerical hydrodynamic simulations. It has been proposed by Gahm et al. (2007) that these clouds may form free-floating planetary mass objects due to shock compression, caused by heating from the intense UV radiation of the central OB star cluster. To address this possibility, lifetimes are calculated for three different 3D simulated cases, similar to globulettes found in the Rose...

  20. Reduced sulfur in euxinic sediments of the Cariaco Basin : Sulfur isotope contraints on organic sulfur formation

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Werne, J.; Lyons, T.W.; Hollander, D.J.; Formolo, M.

    2003-01-01

    Reduced sulfur accumulation in Holocene and latest Pleistocene euxinic marine sediments from the Cariaco Basin, Venezuela, was investigated to constrain the timing and possible pathways of organic matter (OM) sulfurization. Data were collected for a diverse suite of sulfur species, including concent

  1. 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)

  2. Sulfur oxidation genes in diverse deep-sea viruses.

    Science.gov (United States)

    Anantharaman, Karthik; Duhaime, Melissa B; Breier, John A; Wendt, Kathleen A; Toner, Brandy M; Dick, Gregory J

    2014-05-16

    Viruses are the most abundant biological entities in the oceans and a pervasive cause of mortality of microorganisms that drive biogeochemical cycles. Although the ecological and evolutionary effects of viruses on marine phototrophs are well recognized, little is known about their impact on ubiquitous marine lithotrophs. Here, we report 18 genome sequences of double-stranded DNA viruses that putatively infect widespread sulfur-oxidizing bacteria. Fifteen of these viral genomes contain auxiliary metabolic genes for the α and γ subunits of reverse dissimilatory sulfite reductase (rdsr). This enzyme oxidizes elemental sulfur, which is abundant in the hydrothermal plumes studied here. Our findings implicate viruses as a key agent in the sulfur cycle and as a reservoir of genetic diversity for bacterial enzymes that underpin chemosynthesis in the deep oceans. PMID:24789974

  3. Discovery of [FeII]- and H2-emission from protostellar jets in the CB3 and CB230 globules

    CERN Document Server

    Massi, F; Brand, J

    2004-01-01

    Four Bok globules were studied in the Near-Infrared, through narrow-band filters, centered at the 1.644 micron line of [FeII], the H2-line at 2.122 micron, and the adjacent continuum. We report the discovery of [FeII] and H2 protostellar jets and knots in the globules CB3 and CB230. The [FeII]-jet in CB230 is defined by a continuous elongated emission feature, superimposed on which two knots are seen; the brighter one lies at the tip of the jet. The jet is oriented in the same direction as the large-scale CO outflow, and emerges from the nebulosity in which a Young Stellar Object is embedded. The H2 emission associated with this jet is fainter and wider than the [FeII] emission, and is likely coming from the walls of the jet-channel. In CB3 four H2 emission knots are found, all towards the blue-shifted lobe of the large-scale outflow. There is a good correspondence between the location of the knots and the blue-shifted SiO(5-4) emission, confirming that SiO emission is tracing the jet-like flow rather well. N...

  4. Comparison of Milk Fat Globule Membrane (MFGM Proteins of Chianina and Holstein Cattle Breed Milk Samples Through Proteomics Methods

    Directory of Open Access Journals (Sweden)

    Lorraine Pariset

    2009-12-01

    Full Text Available Identification of proteins involved in milk production is important to understand the biology of lactation. Many studies have advanced the understanding of mammary function and milk secretion, but the critical molecular mechanisms implicated in milk fat secretion is still incomplete. Milk Fat Globules are secreted from the apical surface of the mammary cells, surrounded by a thin membrane bilayer, the Milk Fat Globule Membrane (MFGM, formed by proteins which have been suggested to be cholesterolemia-lowering factors, inhibitors of cancer cell growth, vitamin binders, bactericidal, suppressors of multiple sclerosis. Using a proteomic approach, we compared MFGM from milk samples of individuals belonging to two different cattle breeds, Chianina and Holstein, representative of selection for milk and meat traits, respectively. We were able to isolate some of the major MFGM proteins in the examined samples and to identify differences between the protein fractions of the two breeds. We detected differences in the amount of proteins linked to mammary gland development and lipid droplets formation, as well as host defence mechanisms. We have shown that proteomics is a suitable, unbiased method for the study of milk fractions proteins and a powerful tool in nutritional genomics.

  5. Macromolecular Crowding Modifies the Impact of Specific Hofmeister Ions on the Coil-Globule Transition of PNIPAM.

    Science.gov (United States)

    Sakota, Kenji; Tabata, Daiki; Sekiya, Hiroshi

    2015-08-13

    Macromolecular crowding alters many biological processes ranging from protein folding and enzyme reactions in vivo to the precipitation and crystallization of proteins in vitro. Herein, we have investigated the effect of specific monovalent Hofmeister salts (NaH2PO4, NaF, NaCl, NaClO4, and NaSCN) on the coil-globule transition of poly(N-isopropylacrylamide) (PNIPAM) in a crowded macromolecular environment as a model for understanding the specific-ion effect on the solubility and stability of proteins in a crowded macromolecular environment. It was found that although the salts (NaH2PO4, NaF, and NaCl) and the macromolecular crowder (polyethylene glycol) lowered the transition temperature almost independently, the macromolecular crowder had a great impact on the transition temperature in the case of the chaotropes (NaClO4 and NaSCN). The electrostatic repulsion between the chaotropic anions (ClO4(-) or SCN(-)) adsorbed on PNIPAM may reduce the entropic gain of water associated with the excluded volume effect, leading to an increase in the transition temperature, especially in the crowded environment. Furthermore, the affinity of the chaotropic anions for PNIPAM becomes small in the crowded environment, leading to further modification of the transition temperature. Thus, we have revealed that macromolecular crowding alters the effect of specific Hofmeister ions on the coil-globule transition of PNIPAM. PMID:26215482

  6. Mass-dependent sulfur isotope fractionation during reoxidative sulfur cycling

    DEFF Research Database (Denmark)

    Pellerin, André; Bui, Thi Hao; Rough, Mikaella;

    2015-01-01

    The multiple sulfur isotope composition of porewater sulfate from the anoxic marine sapropel of Mangrove Lake, Bermuda was measured in order to establish how multiple sulfur isotopes are fractionated during reoxidative sulfur cycling. The porewater-sulfate d34S and D33S dataset exhibits the...... distinct isotopic signatures of microbial sulfate reduction and sulfur reoxidation. We reproduced the measurements with a simple diagenetic model that yielded fractionation factors for net sulfate removal of between 29.2 0/00 and 32.5 0/00. A new approach to isotopic modeling of the sulfate profiles......, informed by the chemistry of sulfur intermediate compounds in Mangrove Lake, reveals that sulfate reduction produces a relatively small intrinsic fractionation and that an active reoxidative sulfur cycle increases the fractionation of the measured values. Based on the model results, the reoxidative cycle...

  7. Lunar Sulfur Capture System

    Science.gov (United States)

    Berggren, Mark; Zubrin, Robert; Bostwick-White, Emily

    2013-01-01

    The Lunar Sulfur Capture System (LSCS) protects in situ resource utilization (ISRU) hardware from corrosion, and reduces contaminant levels in water condensed for electrolysis. The LSCS uses a lunar soil sorbent to trap over 98 percent of sulfur gases and about two-thirds of halide gases evolved during hydrogen reduction of lunar soils. LSCS soil sorbent is based on lunar minerals containing iron and calcium compounds that trap sulfur and halide gas contaminants in a fixed-bed reactor held at temperatures between 250 and 400 C, allowing moisture produced during reduction to pass through in vapor phase. Small amounts of Earth-based polishing sorbents consisting of zinc oxide and sodium aluminate are used to reduce contaminant concentrations to one ppm or less. The preferred LSCS configuration employs lunar soil beneficiation to boost concentrations of reactive sorbent minerals. Lunar soils contain sulfur in concentrations of about 0.1 percent, and halogen compounds including chlorine and fluorine in concentrations of about 0.01 percent. These contaminants are released as gases such as H2S, COS, CS2,HCl, and HF during thermal ISRU processing with hydrogen or other reducing gases. Removal of contaminant gases is required during ISRU processing to prevent hardware corrosion, electrolyzer damage, and catalyst poisoning. The use of Earth-supplied, single-use consumables to entirely remove contaminants at the levels existing in lunar soils would make many ISRU processes unattractive due to the large mass of consumables relative to the mass of oxygen produced. The LSCS concept of using a primary sorbent prepared from lunar soil was identified as a method by which the majority of contaminants could be removed from process gas streams, thereby substantially reducing the required mass of Earth-supplied consumables. The LSCS takes advantage of minerals containing iron and calcium compounds that are present in lunar soil to trap sulfur and halide gases in a fixedbed reactor

  8. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

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

  9. 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

  10. 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...

  11. Rethinking the Ancient Sulfur Cycle

    Science.gov (United States)

    Fike, David A.; Bradley, Alexander S.; Rose, Catherine V.

    2015-05-01

    The sulfur biogeochemical cycle integrates the metabolic activity of multiple microbial pathways (e.g., sulfate reduction, disproportionation, and sulfide oxidation) along with abiotic reactions and geological processes that cycle sulfur through various reservoirs. The sulfur cycle impacts the global carbon cycle and climate primarily through the remineralization of organic carbon. Over geological timescales, cycling of sulfur is closely tied to the redox state of Earth's exosphere through the burial of oxidized (sulfate) and reduced (sulfide) sulfur species in marine sediments. Biological sulfur cycling is associated with isotopic fractionations that can be used to trace the fluxes through various metabolic pathways. The resulting isotopic data provide insights into sulfur cycling in both modern and ancient environments via isotopic signatures in sedimentary sulfate and sulfide phases. Here, we review the deep-time δ34S record of marine sulfates and sulfides in light of recent advances in understanding how isotopic signatures are generated by microbial activity, how these signatures are encoded in marine sediments, and how they may be altered following deposition. The resulting picture shows a sulfur cycle intimately coupled to ambient carbon cycling, where sulfur isotopic records preserved in sedimentary rocks are critically dependent on sedimentological and geochemical conditions (e.g., iron availability) during deposition.

  12. Mobilization of sulfur by green sulfur bacteria : physiological and molecular studies on Chlorobaculum parvum DSM 263

    OpenAIRE

    Donà, Clelia

    2011-01-01

    Green sulfur bacteria are photolithotrophs that use inorganic sulfur compounds as electron donors for photosynthesis. Elemental, solid sulfur is one of the electron donors used. Sulfur is produced by green sulfur bacteria during the oxidation of sulfide to sulfate, and during the oxidation of thiosulfate to sulfur and sulfate. Green sulfur bacteria have been known for long, and the genomes of 12 strains have been sequenced. Yet, it is not clear how green sulfur bacteria can access elemental s...

  13. A comparison of density structures of a star forming and a non-star-forming globule. DCld303.8-14.2 and Thumbprint Nebula

    CERN Document Server

    Kainulainen, J; Väisänen, P; Bronfman, L; Knude, J

    2006-01-01

    We present a study of radial density structure of the star forming globule, DCld303.8-14.2 (DC303), and a non-star forming globule, Thumbprint Nebula (TPN), using near-infrared data taken with the ISAAC instrument on the Very Large Telescope. We derive the extinction through the globules using the color excess technique and examine the radial density distribution using Bonnor-Ebert and power-law models. The two globules have significantly different density structures. The extinction profile of DC303 is best fitted with a single power-law with an exponent p = 2.29 \\pm 0.08. An unstable Bonnor-Ebert model with a dimensionless parameter \\xi_max = 23 \\pm 3 provides equally good fit to data. The extinction profile of TPN flattens at small radii, making the profile significantly different from the profile of DC303. We are unable to fit the Bonnor-Ebert model for TPN in a robust manner, but derive the lower limit \\xi_max > 8 for the dimensionless outer edge. The density profile derived for TPN is typical compared to...

  14. Bovine milk proteome: Quantitative changes in normal milk exosomes, milk fat globule membranes and whey proteomes resulting from Staphylococcus aureus mastitis

    Science.gov (United States)

    Knowledge of milk protein composition/expression in healthy cows and cows with mastitis will provide information important for the dairy food industry, mammary biology and immune function in the mammary gland. To facilitate maximum protein discovery, milk was fractioned into whey, milk fat globule ...

  15. Obtaining Sulfur from Sulfur Hexafluoride and Studying the Sulfur Isotopes Properties by Using Vibrational Spectroscopy

    OpenAIRE

    Egorov, Nikolai Borisovich; Akimov, Dmitry Vasilievich; Zhuravlev, Nikolay

    2015-01-01

    Scheme of isotopically enriched SF[6] to elemental sulfur with orthorhombic modification conversion is offered. This scheme includes SF[6] reduction to Li2S by using lithium. The yield of isotopically enriched sulfur is not less than 97% with chemical purity not less than 99.9%. The results which show the dependence of the experimental frequencies in the vibrational spectra on the molecular weight of the sulfur isotope have been obtained.

  16. [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

  17. Vers une modélisation mathématique de la filtration des globules blancs du sang

    OpenAIRE

    Belhadj, Mohamed

    2005-01-01

    Cette thèse concerne l'étude de modèles mathématiques et méthodes numériques motivés par la filtration des globules blancs du sang. Dans la première partie, nous définissons des modèles mathématiques qui réprésentent les principaux phénomènes physiques qui entrent en jeu dans le procédé de la filtration.La deuxième partie est dédiée à l'analyse mathématique de systèmes d'équations aux dérivées partielles modélisant le procédé de la filtration. Tout d'abord, nous considérons un système d'équat...

  18. G70.7+1.2: A nonthermal bubble in a globule - nova, supernova remnant, or outflow?

    International Nuclear Information System (INIS)

    Millimeter-wave, near-IR, and 21 cm observations of the radio source G70.7 + 1.2 , which has been proposed to be a recent SNR developing inside a molecular cloud, are presented. A small molecular cloud with properties similar to a large dark cloud or globule is interacting with the nonthermal radio continuum source. The molecular cloud has a lumpy structure with its highest column density portion lying just outside the brightest portion of the radio continuum shell. If the radio source was produced by a supernova explosion, its kinetic energy was several orders of magnitude less than that of most observed supernovae. An OB star wind with certain characteristics is sufficient to drive the bubble, but the high radio continuum nonthermal surface brightness and polarization of the object is not explained by this model. 23 references

  19. 1-Anilino-8-naphthalene sulfonate (ANS is not a desirable probe for determining the molten globule state of chymopapain.

    Directory of Open Access Journals (Sweden)

    Atiyatul Qadeer

    Full Text Available The molten globule (MG state of proteins is widely detected through binding with 1-anilino-8-naphthalene sulphonate (ANS, a fluorescent dye. This strategy is based upon the assumption that when in molten globule state, the exposed hydrophobic clusters of protein are readily bound by the nonpolar anilino-naphthalene moiety of ANS molecules which then produce brilliant fluorescence. In this work, we explored the acid-induced unfolding pathway of chymopapain, a cysteine proteases from Carica papaya, by monitoring the conformational changes over a pH range 1.0-7.4 by circular dichroism, intrinsic fluorescence, ANS binding, acrylamide quenching, isothermal titration calorimetry (ITC and dynamic light scattering (DLS. The spectroscopic measurements showed that although maximum ANS fluorescence intensity was observed at pH 1.0, however protein exhibited ∼80% loss of secondary structure which does not comply with the characteristics of a typical MG-state. In contrast at pH 1.5, chymopapain retains substantial amount of secondary structure, disrupted side chain interactions, increased hydrodynamic radii and nearly 30-fold increase in ANS fluorescence with respect to the native state, indicating that MG-state exists at pH 1.5 and not at pH 1.0. ITC measurements revealed that ANS molecules bound to chymopapain via hydrophobic interaction were more at pH 1.5 than at pH 1.0. However, a large number of ANS molecules were also involved in electrostatic interaction with protein at pH 1.0 which, together with hydrophobically interacted molecules, may be responsible for maximum ANS fluorescence. We conclude that maximum ANS-fluorescence alone may not be the criteria for determining the MG of chymopapain. Hence a comprehensive structural analysis of the intermediate is essentially required.

  20. Speciation and isotopic composition of sulfur in sediments from Jellyfish Lake, Palau

    Science.gov (United States)

    Bates, A.L.; Spiker, E. C.; Orem, W.H.; Burnett, W.C.

    1993-01-01

    Jellyfish Lake, Palau, is a meromictic marine lake with high organic productivity, low reactive Fe content, and anoxic bottom waters. Sediment samples from Jellyfish Lake were examined for the distribution of sulfur species and their isotopic signatures in order to gain a better understanding of sedimentary sulfur incorporation in Fe-poor environments. Surface samples were taken along a transect from a near-shore site to the center of the lake, and include a sample below oxic water, a sample below the chemocline layer, and samples below anoxic waters. Three additional samples were taken from a core, 2 m long, collected near the lake center. Sulfur to organic carbon weight ratios in all samples were lower than the expected value of 0.36 for normal marine sediment, probably because the lake water is deficient in reactive Fe to form iron sulfides. Total sulfur contents in the surface sediments indicated no changes with distance from shore; however, the sulfur content of the surface sample at the chemocline layer may be slightly higher. Total sulfur content increased with depth in the core and is inversely related to organic carbon content. Organic sulfur is the major sulfur species in the samples, followed in descending order by sulfate, disulfides and monosulfides. Sulfate sulfur isotope ??34S-values are positive (from +20.56 to +12.04???), reflecting the marine source of sulfate in Jellyfish Lake. Disulfide and monosulfide ??34S-values are negative (from -25.07 to -7.60???), because of fractionation during bacterial reduction of sulfate. Monosulfide ??34S-values are somewhat higher than those of disulfides, and they are close to the ??34S-values of organic sulfur. These results indicate that most of the organic sulfur is formed by reaction of bacteriogenic monosulfides, or possibly monosulfide-derived polysulfides, with organic matter in the sediment. ?? 1993.

  1. Sulfur meter speeds coal blending

    International Nuclear Information System (INIS)

    The sulfur content has become the most important criterion that industry looks at when purchasing coal. The exact amount of sulfur in coal being processed by a preparation plant must be known and, if possible, controlled by blending coal streams of various sulfur contents. Present techniques, however, of measuring the sulfur in coal involve laborious and time-consuming sampling and chemical analysis (12 to 24 hr), and the results usually are not available until the following day. By then, the coal barges or trains are already on the way to their destinations. A new nuclear sulfur meter is expected to overcome these difficulties and help lead to true automation in coal preparation plants. Initially developed by the Bureau of Mines' Morgantown Energy Research Center (MERC) at Morgantown, W. Va., and completed after reorganization of the center by the US Energy Research and Development Administration (ERDA), the meter can scan coal to produce a reading within 2 min to an accuracy of 0.04 percent sulfur. The meter is expected to soon result in an element-ash-moisture-Btu meter that would rapidly detect the sulfur, sodium, potassium, and overall mineral content of the coal, as well as its ash and Btu content

  2. 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.

  3. Close interspecies interactions between prokaryotes from sulfureous environments

    Directory of Open Access Journals (Sweden)

    JörgOvermann

    2011-07-01

    Full Text Available Green sulfur bacteria are obligate photolithoautotrophs that require highly reducing conditions for growth and can utilize only a very limited number of carbon substrates. These bacteria thus inhabit a very narrow ecologic niche. However, several green sulfur bacteria have overcome the limits of immobility by entering into a symbiosis with motile Betaproteobacteria in a type of multicelllular association termed phototrophic consortia. One of these consortia, “Chlorochromatium aggregatum”, has recently been established as the first culturable model system to elucidate the molecular basis of this symbiotic interaction. It consists of 12-20 green sulfur bacteria epibionts surrounding a central, chemoheterotrophic betaproteobacterium in a highly ordered fashion. Recent genomic, transcriptomic, and proteomic studies of "C. aggregatum" and its epibiont provide insights into the molecular basis and the origin of the stable association between the two very distantly related bacteria. While numerous genes of central metabolic pathways are upregulated during and hence involved in the specific symbiosis, only a limited number of unique putative symbiosis genes have been detected in the epibiont. Green sulfur bacteria therefore are preadapted to a symbiotic lifestyle. The metabolic coupling between the bacterial partners appears to involve amino acids and highly specific ultrastructures at the contact sites between the cells. Similarly, the interaction in the equally well studied archaeal consortia consisting of Nanoarchaeum equitans and its host Ignicoccus hospitalis is based on the transfer of amino acids while lacking the highly specialized contact sites observed in phototrophic consortia.

  4. Study of the variables which influence the impregnation of globules, compressed tablets and tablet triturates used in homeopathy

    Directory of Open Access Journals (Sweden)

    Fernanda Santos de Souza

    2012-09-01

    Full Text Available Globules, compressed tablets and tablet triturates are solid dosage forms used in homeopathy. Divergences can be noted between the preparation techniques described in official compendiums as well as those applied in homeopathic pharmacies. The difficulty associated with standardization of the impregnation of these dosage forms occurs due to the lack of detail provided for the techniques in the literature, leaving it up to each pharmacy to decide on the exact method of preparation. The objective was to optimize the impregnation technique, through investigating the variables that influence the impregnation of globules, compressed tablets and tablet triturates, applying the statistical tool of factorial design. The independent variables were the dosage form, percentage and type of impregnation and drying temperature, and the dependent variables were the mass gain, disintegration time, friability and hardness. For the globules, the greatest mass gain was for 10% impregnation and drying at 20 ºC. For the tablet triturates and compressed tablets the greatest mass gain was for 15% impregnation and there was no difference between the results obtained using simple and triple impregnation or different drying temperatures. The results can contribute to improving the final product quality, besides aiding in the establishment of standardized techniques for the official compendiums.Glóbulos, comprimidos e tabletes são formas farmacêuticas sólidas utilizadas em homeopatia. Constatam-se divergências entre técnicas de preparação descritas nos compêndios oficiais, bem como em farmácias homeopáticas. A dificuldade de padronização na impregnação destas formas farmacêuticas também ocorre devido à falta de detalhamento das técnicas na literatura existente, deixando para cada farmácia a escolha de como executá-las. O objetivo foi otimizar a técnica de impregnação, através do estudo de variáveis que interferem na impregnação de gl

  5. 46 CFR 148.04-20 - Sulfur.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfur. 148.04-20 Section 148.04-20 Shipping COAST GUARD... Special Additional Requirements for Certain Material § 148.04-20 Sulfur. (a) When sulfur is loaded in a deep hold with general cargo in the 'tween deck hold above the sulfur, a dust proof wooden...

  6. Method of preparing graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jun; Lemmon, John P; Yang, Zhenguo; Cao, Yuliang; Li, Xiaolin

    2015-04-07

    A method of preparing a graphene-sulfur nanocomposite for a cathode in a rechargeable lithium-sulfur battery comprising thermally expanding graphite oxide to yield graphene layers, mixing the graphene layers with a first solution comprising sulfur and carbon disulfide, evaporating the carbon disulfide to yield a solid nanocomposite, and grinding the solid nanocomposite to yield the graphene-sulfur nanocomposite. Rechargeable-lithium-sulfur batteries having a cathode that includes a graphene-sulfur nanocomposite can exhibit improved characteristics. The graphene-sulfur nanocomposite can be characterized by graphene sheets with particles of sulfur adsorbed to the graphene sheets. The sulfur particles have an average diameter of less than 50 nm.

  7. Interactions of selected bacterial isolates with DBT and solubilized coal

    Energy Technology Data Exchange (ETDEWEB)

    Key, D.H.; Fox, R.V.; Kase, R.S.; Willey, M.S.; Stoner, D.L.; Ward, T.E.

    1990-01-01

    We are studying the interactions of isolated bacteria with dibenzothiophene (DBT), a sulfur-containing model compound, and with a solubilized coal product derived from a high-organic-sulfur lignite. The sensitivity of the tetrazolium assay used to identify and study these strains was improved by substituting tetrazolium violet for triphenyltetrazolium. DBT metabolism by thirteen strains was investigated using qualitative and quantitative GC and GC-MS analyses. Growth medium and incubation time affect the extent of DBT degradation and the production of DBT metabolites. Under specific conditions, seven of the strains produce metabolites which elute close to the position of one or another of the biphenyl standards. However, when these samples are spiked with the standard compounds, the bacterial metabolites do not co-elute with the standards. The modification of solubilized high-organic-sulfur coal by six of these strains was also studied. No selective removal of sulfur relative to carbon was observed. 13 refs., 1 fig., 2 tabs.

  8. Comprehensive phylogenetic analysis of bacterial reverse transcriptases.

    Directory of Open Access Journals (Sweden)

    Nicolás Toro

    Full Text Available Much less is known about reverse transcriptases (RTs in prokaryotes than in eukaryotes, with most prokaryotic enzymes still uncharacterized. Two surveys involving BLAST searches for RT genes in prokaryotic genomes revealed the presence of large numbers of diverse, uncharacterized RTs and RT-like sequences. Here, using consistent annotation across all sequenced bacterial species from GenBank and other sources via RAST, available from the PATRIC (Pathogenic Resource Integration Center platform, we have compiled the data for currently annotated reverse transcriptases from completely sequenced bacterial genomes. RT sequences are broadly distributed across bacterial phyla, but green sulfur bacteria and cyanobacteria have the highest levels of RT sequence diversity (≤85% identity per genome. By contrast, phylum Actinobacteria, for which a large number of genomes have been sequenced, was found to have a low RT sequence diversity. Phylogenetic analyses revealed that bacterial RTs could be classified into 17 main groups: group II introns, retrons/retron-like RTs, diversity-generating retroelements (DGRs, Abi-like RTs, CRISPR-Cas-associated RTs, group II-like RTs (G2L, and 11 other groups of RTs of unknown function. Proteobacteria had the highest potential functional diversity, as they possessed most of the RT groups. Group II introns and DGRs were the most widely distributed RTs in bacterial phyla. Our results provide insights into bacterial RT phylogeny and the basis for an update of annotation systems based on sequence/domain homology.

  9. Toxicology of sulfur in ruminants: review

    Energy Technology Data Exchange (ETDEWEB)

    Kandylis, K.

    1984-10-01

    This review deals with the toxicology of sulfur in ruminants including toxicity, neurotoxic effects, and mechanism of toxic action of hydrogen sulfide, clinical signs, and treatment. It will report effects of excessive intake of sulfur by ruminants on feed intake, animal performance, ruminal digestion and motility, rumination, and other physiological functions. Poisoning of animals with sulfur from industrial emissions (sulfur dioxide) also is discussed. Excessive quantities of dietary sulfur (above .3 to .4%) as sulfate or elemental sulfur may cause toxic effects and in extreme cases can be fatal. The means is discussed whereby consumption of excessive amounts of sulfur leads to toxic effects. 53 references, 1 table.

  10. Graphene-sulfur nanocomposites for rechargeable lithium-sulfur battery electrodes

    Science.gov (United States)

    Liu, Jun; Lemmon, John P; Yang, Zhenguo; Cao, Yuiliang; Li, Xiaolin

    2014-06-17

    Rechargeable lithium-sulfur batteries having a cathode that includes a graphene-sulfur nanocomposite can exhibit improved characteristics. The graphene-sulfur nanocomposite can be characterized by graphene sheets with particles of sulfur adsorbed to the graphene sheets. The sulfur particles have an average diameter less than 50 nm..

  11. 40 CFR 50.5 - National secondary ambient air quality standard for sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ... standard for sulfur oxides (sulfur dioxide). 50.5 Section 50.5 Protection of Environment ENVIRONMENTAL....5 National secondary ambient air quality standard for sulfur oxides (sulfur dioxide). (a) The level... than 0.05 ppm shall be rounded up). (b) Sulfur oxides shall be measured in the ambient air as...

  12. 40 CFR 50.17 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.17 Section 50.17 Protection of Environment ENVIRONMENTAL....17 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). (a) The level of the national primary 1-hour annual ambient air quality standard for oxides of sulfur is 75...

  13. 40 CFR 50.4 - National primary ambient air quality standards for sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ... standards for sulfur oxides (sulfur dioxide). 50.4 Section 50.4 Protection of Environment ENVIRONMENTAL....4 National primary ambient air quality standards for sulfur oxides (sulfur dioxide). Link to an... to or greater than 0.005 ppm shall be rounded up). (c) Sulfur oxides shall be measured in the...

  14. Determination of the physical parameters of Bok-globules by means of a stochastical radiative transfer method

    Science.gov (United States)

    Hengel, C.; Hegmann, M.; Röllig, M.; Kegel, W. H.

    During the last years, one of the key projects of the Astrophysics group at the University of Frankfurt was the theoretical examination of the influence of turbulence and density fluctuations on the formation of interstellar molecular lines, especially CO lines (Albrecht & Kegel 1987, Kegel et al. 1993, Piehler & Kegel 1995, Hegmann 1999). Based on an approach by G. Traving and collaborators (cf. Gail et al. 1974), a numerical code has been developed to deal with the NLTE problem in an isothermal spherical cloud being stabelized by turbulent and thermal pressure, considering the turbulent velocity field to be stochastic. Our model has been primarily constructed to achieve theoretical insight in the fundamental mechanisms of line formation under more realistic conditions. In view of the stage of development, the model has actually reached, we seriously think of it as an alternative tool for the evaluation of molecular lines emitted by molecular clouds, especially as the model assumptions are certainly closer to reality than the assumptions behind the standard evaluation methods such as e. g. LVG analysis. The objects the physics of which we believe to be closest to our model assumptions are starless Bok globules. We thus have performed observations at the HHT, where we have collected data of five Bok globules in the CO(2-1), CO(3-2), 13CO(2-1) and C18O(2-1) lines. In my contribution I will adress the question, if and how the physical parameters derived by our analysis of the observational data (central H2 density, temperature, correlation length of the turbulent velocity field, and mean square turbulent velocity) differ from the results of an LVG analysis (they do!) and what these findings imply from a physical point of view as well as from a critical viewpoint on the practice of data evaluation. I will talk about problems of our model at its current stage and possible consequences for an improvement of the model, and I will finally give an outlook, how, with

  15. Sulfur dioxide scrubbing system

    Energy Technology Data Exchange (ETDEWEB)

    Dahlstrom, D.A.; Cornell, C.F.

    1976-11-02

    Sulfur dioxide is scrubbed from stack gases in an absorption device by a sodium-based aqueous scrubbing solution, a portion of which is subsequently and continuously regenerated outside the absorption apparatus by a causticizing reaction with slaked lime. The causticized solution is routed through a settling device wherefrom a portion of the aqueous sediment is returned to the causticizing zone to provide seed crystals which encourage the formation of larger sized solid particles; also, a portion of the aqueous sediment from the settling device is continuously mechanically dewatered and then removed from the system. The liquid effluent solution from the settling device is passed to a solids-contacting and reaction device for mixing with sodium carbonate in order to reduce the calcium ion concentration and the solids content of the solution. The underflow of the solids-contacting device is conveyed back to the causticizing zone and the clarified overflow, i.e., the regenerated scrubbing liquor, is conveyed to the absorption apparatus.

  16. For sale: Sulfur emissions

    International Nuclear Information System (INIS)

    The allowance trading market has started a slow march to maturity. Competitive developers should understand the risks and opportunities now presented. The marketplace for sulfur dioxide (SO2) emissions allowances - the centerpiece of Title 4's acid rain reduction program - remains enigmatic 19 months after the Clean Air Act amendments of 1990 were passed. Yet it is increasingly clear that the emission allowance market will likely confound the gloom and doom of its doubters. The recently-announced $10 million dollar Wisconsin Power and Light allowance sales to Duquesne Light and the Tennessee Valley Authority are among the latest indications of momentum toward a stabilizing market. This trend puts additional pressure on independent developers to finalize their allowance strategies. Developers who understand what the allowance trading program is and what it is not, know the key players, and grasp the unresolved regulatory issues will have a new competitive advantage. The topics addressed in this article include the allowance marketplace, marketplace characteristics, the regulatory front, forward-looking strategies, and increasing marketplace activity

  17. Transporters in plant sulfur metabolism

    OpenAIRE

    Gigolashvili, Tamara; Kopriva, Stanislav

    2014-01-01

    Sulfur is an essential nutrient, necessary for synthesis of many metabolites. The uptake of sulfate, primary and secondary assimilation, the biosynthesis, storage, and final utilization of sulfur (S) containing compounds requires a lot of movement between organs, cells, and organelles. Efficient transport systems of S-containing compounds across the internal barriers or the plasma membrane and organellar membranes are therefore required. Here, we review a current state of knowledge of the tra...

  18. Plant sulfur and Big Data.

    Science.gov (United States)

    Kopriva, Stanislav; Calderwood, Alexander; Weckopp, Silke C; Koprivova, Anna

    2015-12-01

    Sulfur is an essential mineral nutrient for plants, therefore, the pathways of its uptake and assimilation have been extensively studied. Great progress has been made in elucidation of the individual genes and enzymes and their regulation. Sulfur assimilation has been intensively investigated by -omics technologies and has been target of several genome wide genetic approaches. This brought a significant step in our understanding of the regulation of the pathway and its integration in cellular metabolism. However, the large amount of information derived from other experiments not directly targeting sulfur has also brought new and exciting insights into processes affecting sulfur homeostasis. In this review we will integrate the findings of the targeted experiments with those that brought unintentional progress in sulfur research, and will discuss how to synthesize the large amount of information available in various repositories into a meaningful dissection of the regulation of a specific metabolic pathway. We then speculate how this might be used to further advance knowledge on control of sulfur metabolism and what are the main questions to be answered. PMID:26706053

  19. Bacterial Mobilization of Nutrients From Biochar-Amended Soils.

    Science.gov (United States)

    Schmalenberger, A; Fox, A

    2016-01-01

    Soil amendments with biochar to improve soil fertility and increase soil carbon stocks have received some high-level attention. Physical and chemical analyses of amended soils and biochars from various feedstocks are reported, alongside some evaluations of plant growth promotion capabilities. Fewer studies investigated the soil microbiota and their potential to increase cycling and mobilization of nutrients in biochar-amended soils. This review is discussing the latest findings in the bacterial contribution to cycling and mobilizing nitrogen, phosphorus, and sulfur in biochar-amended soils and potential contributions to plant growth promotion. Depending on feedstock, pyrolysis, soil type, and plant cover, changes in the bacterial community structure were observed for a majority of the studies using amplicon sequencing or genetic fingerprinting methods. Prokaryotic nitrification largely depends on the availability of ammonium and can vary considerably under soil biochar amendment. However, denitrification to di-nitrogen and in particular, nitrous oxide reductase activity is commonly enhanced, resulting in reduced nitrous oxide emissions. Likewise, bacterial fixation of di-nitrogen appears to be regularly enhanced. A paucity of studies suggests that bacterial mobilization of phosphorus and sulfur is enhanced as well. However, most studies only tested for extracellular sulfatase and phosphatase activity. Further research is needed to reveal details of the bacterial nutrient mobilizing capabilities and this is in particular the case for the mobilization of phosphorus and sulfur. PMID:26917243

  20. A statistical theory of coil-to-globule-to-coil transition of a polymer chain in a mixture of good solvents

    Science.gov (United States)

    Budkov, Yu. A.; Kolesnikov, A. L.; Kalikin, N. N.; Kiselev, M. G.

    2016-05-01

    We present an off-lattice statistical model of a single polymer chain in mixed-solvent media. Taking into account the polymer conformational entropy, renormalization of solvent composition near the polymer backbone, the universal intermolecular excluded-volume and van der Waals interactions within the self-consistent field theory, the reentrant coil-to-globule-to-coil transition (co-nonsolvency) has been described in this paper. For convenience we split the system volume in two parts: the volume occupied by the polymer chain and the volume of bulk solution. Considering the equilibrium between two sub-volumes, the polymer solvation free energy as a function of radius of gyration and co-solvent mole fraction within internal polymer volume has been obtained. Minimizing the free energy of solvation with respect to its arguments, we show two qulitatively different regimes of co-nonsolvency. Namely, at sufficiently high temperature the reentrant coil-to-globule-to-coil transition proceeds smoothly. On the contrary, when the temperature drops below a certain threshold value a coil-globule transition occurs in the regime of first-order phase transition, i.e., discontinuous changes of the radius of gyration and the local co-solvent mole fraction near the polymer backbone. We show that, when the collapse of the polymer chain takes place, the entropy and enthalpy contributions to the solvation free energy of the globule strongly grow. From the first principles of statistical thermodynamics we confirm earlier speculations based on the MD simulations results that the co-nonsolvency is the essentially enthalpic-entropic effect and is caused by enthalpy-entropy compensation. We show that the temperature dependences of the solution heat capacity change due to the solvation of the polymer chain are in qualitative agreement with the differential scanning calorimetry data for PNIPAM in aqueous methanol.

  1. Effect of feeding camphor (Eucalyptus Globules) levels on some immunity characteristics, growth and gut microflora of japanese quails

    International Nuclear Information System (INIS)

    This experiment was conducted to evaluate the effect of adding Eucalyptus globules Egypt to Japanese quail diet on performance and some metabolic functions and immunity. Four hundred,one day old, unsexed japanese quails were used in this study. Quails were divided equally into four groups containing 100 birds in each. Each group contained 4 replicates of 25 birds. Group one was supplemented with 1% Egypt in basal diet, group two was supplemented with 2% Egypt in basal diet, group three was used as negative control (-ve)without any addition of antibiotic in diet or water, while group four represented the positive control (+ ve) by addition antibiotics (0.5 g neomycin sulphate +0.5 g oxytetracyclin) in drinking water for 5 days post hatching. The experimented diet contained 3200 Kcal ME/kg and 24% crude proteins. The end of the experiment was terminated when birds were 6 weeks old. Body weight, mortality, some organs weighs and some blood parameters were measured and some microbial population of small intestines was counted. Results indicated that the addition of Egypt led to significant increase in quails body weights, spleen, bursa and ovary and the measures of total proteins, globulins, haemagglutination inhibition (HI)and triiodothyronine (T3). Decrease in mortality ratio and less counts of microflora and salmonella of gut were also achieved as a result of diet camphor addition

  2. Effect of hydrostatic pressure on conformational changes of canine milk lysozyme between the native, molten globule, and unfolded states.

    Science.gov (United States)

    Watanabe, Masahiro; Aizawa, Tomoyasu; Demura, Makoto; Nitta, Katsutoshi

    2004-11-01

    The effect of pressure on the unfolding of the native (N) and molten globule (MG) state of canine milk lysozyme (CML) was examined using ultraviolet (UV) spectroscopy at pH 4.5 and 2.0, respectively. It appeared that the thermally induced unfolding was promoted by the increase of pressure from atmospheric to 100 MPa, which indicates that both the N and MG states of CML unfolded with the decrease of the partial molar volume change (DeltaV). The volume changes needed for unfolding were estimated from the free energy change vs. pressure plots, and these volume changes became less negative from 20 to 60 degrees C. The DeltaV values at 25 degrees C were obtained for the N-MG (-46 cm3/mol) and MG-unfolded-state (U) transition (-40 cm3/mol). With regards to the MG-U transition, this value is contrastive to that of bovine alpha-lactalbumin (BLA) (0.9 cm3/mol), which is homologous to CML. Previous studies revealed that the MG state of CML was significantly more stable, and closer to the N state in structure, than that of BLA. In contrast to the swollen hydrophobic core of the MG state of BLA, our results suggest that the MG state of CML possesses a tightly packed hydrophobic core into which water molecules cannot penetrate. PMID:15488764

  3. Interaction products of sulfuric acid and sulfurous compounds of sour oil and their structural properties

    International Nuclear Information System (INIS)

    Present article is devoted to interaction products of sulfuric acid and sulfurous compounds of sour oil and their structural properties. The results of studies of obtaining of sulfides by complex formation with 86% sulfuric acid from sour oil were considered.

  4. Dimethylmercury Formation Mediated by Inorganic and Organic Reduced Sulfur Surfaces

    OpenAIRE

    Sofi Jonsson; Nashaat M. Mazrui; Mason, Robert P.

    2016-01-01

    Underlying formation pathways of dimethylmercury ((CH3)2Hg) in the ocean are unknown. Early work proposed reactions of inorganic Hg (HgII) with methyl cobalamin or of dissolved monomethylmercury (CH3Hg) with hydrogen sulfide as possible bacterial mediated or abiotic pathways. A significant fraction (up to 90%) of CH3Hg in natural waters is however adsorbed to reduced sulfur groups on mineral or organic surfaces. We show that binding of CH3Hg to such reactive sites facilitates the formation of...

  5. Microbial extraction of sulfur from model coal organosulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Purdy, R.F.; Ward, B.; Lepo, J.E. [Mississippi Univ., University, MS (United States)

    1991-12-31

    Several hundred bacterial cultures isolated from a variety of natural sites were screened for their ability to desulfurize the model coal organosulfur compounds, dibenzothiophene (DBT) and DBT-sulfone. A sulfur-stress assay, in which DBT-sulfone was the only bioavailable source of sulfur, was used to screen and select for organisms that selectively desulfurized the organic-sulfur substrate. Only two new isolates, UMX9 and UMX3, and strain IGTS-8, a Rhodococcus rhodochrous provided by the Institute for Gas Technology (Chicago, USA.) as a reference culture, would grow on DBT or DBT-sulfone as a sole source of sulfur. Under sulfur-stress conditions, a desulfurized product identified as 2-hydroxybiphenyl (2-phenylphenol) was detected only for UMX9 and IGTS-8. Biodesulfurization activity for all three organisms occurred only for growing cultures, and was depressed by free sulfate, although more so for UMX3 and IGTS-8 than for UMX9. None of the three cultures exhibited good growth on DBT, DBT-sulfone, or 2-phenylphenol as sole sources of carbon. Taxonomic studies revealed UMX3 to be similar to IGTS-8, whereas UMX9 only exhibited Rhodococcus-like features. Comparative tests for carbohydrate utilization revealed that only UMX9 would grow on glucose, and that only IGTS-8 would grow on L-arabinose. Assays of biodesulfurization activity as a function of temperature or pH revealed further differences between UMX9 and UMX3/IGTS-8. Under optimized assay conditions for each organism, UMX9 exhibited up to 30% greater biodesulfurization activity than did IGTS-8 and UMX3, which were similar in activity.

  6. Monoclinic sulfur cathode utilizing carbon for high-performance lithium-sulfur batteries

    Science.gov (United States)

    Jung, Sung Chul; Han, Young-Kyu

    2016-09-01

    Sulfur cathodes for lithium-sulfur batteries have been designed to be combined with conductive carbon because the insulating nature of sulfur causes low active material utilization and poor rate capability. This paper is the first to report that carbon can induce a phase transition in a sulfur cathode. The stable form of a sulfur crystal at ambient temperature is orthorhombic sulfur. We found that monoclinic sulfur becomes more stable than orthorhombic sulfur if carbon atoms penetrate into the sulfur at elevated temperatures and the carbon density exceeds a threshold of C0.3S8. The high stability of the carbon-containing monoclinic sulfur persists during lithiation and is attributed to locally formed linear SC3S chains with marked stability. This study provides a novel perspective on the role of carbon in the sulfur cathode and suggests control of the crystal phase of electrodes by composite elements as a new way of designing efficient electrode materials.

  7. Influence of acid precipitation on bacterial populations in lakes

    Energy Technology Data Exchange (ETDEWEB)

    Rao, S.S.; Dutka, B.J.

    1983-01-01

    Relative abundance of total, respiring, aerobic heterotrophic, nitrogen cycle and sulfur cycle bacteria was measured in acid stressed and non-acid stressed hardwater lakes. Data indicated that bacterial populations and densities were nearly an order of magnitude less in acid stressed waters than in non-acid stressed waters. Nitrifying bacteria and some sulfur cycle bacteria (Thiobacillus sp.) were very low or absent in acid stressed waters. Surface sediments of acid stressed lakes contained 3 to 4 times more organic matter than the amount found in the relatively more enriched lake. Methodology and data are presented. 20 references, 1 figure, 1 table.

  8. Biochemical mechanisms for the desulfurization of coal-relevant organic sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Afferden, M. van; Tappe, D.; Beyer, M.; Trueper, H.G.; Klein, J. (DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany))

    1993-12-01

    Two microbial strains ([ital Brevibacterium] sp. DO, [ital Pseudomonas aeruginosa] OS1) were isolated for their ability to desulfurize dibenzothiophene (DBT) and benzyl methyl sulfide (BMS). Enrichment was achieved by a sulfur-selective screening system using the model compounds as the sole source of sulfur for bacterial growth. [ital Brevibacterium] sp. DO utilizes DBT as a sole source of sulfur, carbon and energy for growth, whereas [ital Pseudomonas aeruginosa] OS1 metabolizes BMS to only a small extent under sulfur-selective conditions. Investigations of the regulation of enzymes involved in the desulfurization of coal-relevant sulfur compounds indicate that in nature at least two mechanisms exist: 'carbon regulation' and 'sulfur regulation'. The biochemical mechanisms leading to the desulfurization of BMS and DBT are similar. The sulfur atom of both compounds is initially oxidized to the corresponding sulfone, and cleavage of the C-S bond proceeds via the formation of a chemically unstable hemimercaptal (S-oxidized form) by oxidation of the carbon atom adjacent to the sulfur atom. These results indicate that oxidation of sulfur to its highest oxidation state may be the precondition for the oxidative cleavage of the covalent C-S bonds. By isotope-labelling experiments using [sup 18]O[sub 2], the initial enzymes were identified as sulfoxygenases that use molecular oxygen. Cleavage of the C-S bond of DBT and BMS leads to the formation of organic sulfinic acids as intermediates. With DBT the sulfinic acid is desulfurized probably by hydrolysis; this results in the formation of sulfite and benzoate. The desulfurization of BMS proceeds by sulfonic acid-oxidation. The applicability of these biochemical mechanisms to the microbial desulfurization of coal is discussed. 39 refs., 10 figs., 2 tabs.

  9. Sulfur Speciation in the Martian Regolith Component in Shergottite Glasses

    Science.gov (United States)

    Rao, M. N.; Nyquist, Laurence E.; Sutton, S.; Huth, J.

    2009-01-01

    We have shown that Gas-Rich Impact-Melt (GRIM) glasses in Shergotty, Zagami, and EET79001 (Lith A and Lith B) contain Martian regolith components that were molten during impact and quenched into glasses in voids of host rock materials based on neutron-capture isotopes, i.e., Sm-150 excesses and Sm-149 deficits in Sm, and Kr-80 excesses produced from Br [1, 2]. These GRIM glasses are rich in S-bearing secondary minerals [3.4]. Evidence for the occurrence of CaSO4 and S-rich aluminosilicates in these glasses is provided by CaO-SO3 and Al2O3-SO3 correlations, which are consistent with the finding of gypsum laths protruding from the molten glass in EET79001 (Lith A) [5]. However, in the case of GRIM glasses from EET79001 (Lith B), Shergotty and Zagami, we find a different set of secondary minerals that show a FeO-SO3 correlation (but no MgOSO3 correlation), instead of CaO-SO3 and Al2O3-SO3 correlations observed in Lith A. These results might indicate different fluidrock interactions near the shergottite source region on Mars. The speciation of sulfur in these salt assemblages was earlier studied by us using XANES techniques [6], where we found that Lith B predominantly contains Fe-sulfide globules (with some sulfate). On the other hand, Lith A showed predominantly Casulfite/ sulfate with some FeS. Furthermore, we found Fe to be present as Fe2+ indicating little oxidation, if any, in these glasses. To examine the sulfide-sulfate association in these glasses, we studied their Fe/Ni ratios with a view to find diagnostic clues for the source fluid. The Fe-sulfide mineral (Fe(0.93)Ni(0.3)S) in EET79001, Lith A is pyrrhotite [7, 8]. It yields an Fe/Ni ratio of 31. In Shergotty, pyrrhotite occurs with a molar ratio of Fe:S of 0.94 and a Ni abundance of 0.12% yielding a Fe/Ni ratio of approx.500 [8]. In this study, we determined a NiO content of approx.0.1% and FeO/NiO ratio of approx.420 in S-rich globules in #507 (EET79001, Lith B) sample using FE-SEM. In the same sample

  10. Sulfur monochloride in organic synthesis

    International Nuclear Information System (INIS)

    The data on the reactivity of sulfur monochloride published in the past 15 years have been reviewed and systematized. The review focuses on the synthesis of acyclic and heterocyclic compounds with the use of S2Cl2. The bibliography includes 154 references

  11. 21 CFR 582.1095 - Sulfuric acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sulfuric acid. 582.1095 Section 582.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1095 Sulfuric acid. (a) Product. Sulfuric acid. (b) Conditions of use. This substance is...

  12. Cholesterol strongly affects the organization of lipid monolayers studied as models of the milk fat globule membrane: Condensing effect and change in the lipid domain morphology.

    Science.gov (United States)

    Murthy, Appala Venkata Ramana; Guyomarc'h, Fanny; Paboeuf, Gilles; Vié, Véronique; Lopez, Christelle

    2015-10-01

    The biological membrane that surrounds the milk fat globules exhibits phase separation of polar lipids that is poorly known. The objective of this study was to investigate the role played by cholesterol in the organization of monolayers prepared as models of the milk fat globule membrane (MFGM). Differential scanning calorimetry and X-ray diffraction experiments allowed characterization of the gel to liquid crystalline phase transition temperature of lipids, Tm ~35°C, in vesicles prepared with a MFGM lipid extract. For temperature below Tm, atomic force microscopy revealed phase separation of lipids at 30 mN·m(-1) in Langmuir-Blodgett monolayers of the MFGM lipid extract. The high Tm lipids form liquid condensed (LC) domains that protrude by about 1.5 nm from the continuous liquid expanded (LE) phase. Cholesterol was added to the MFGM extract up to 30% of polar lipids (cholesterol/milk sphingomyelin (MSM) molar ratio of 50/50). Compression isotherms evidenced the condensing effect of the cholesterol onto the MFGM lipid monolayers. Topography of the monolayers showed a decrease in the area of the LC domains and in the height difference H between the LC domains and the continuous LE phase, as the cholesterol content increased in the MFGM lipid monolayers. These results were interpreted in terms of nucleation effects of cholesterol and decrease of the line tension between LC domains and LE phase in the MFGM lipid monolayers. This study revealed the major structural role of cholesterol in the MFGM that could be involved in biological functions of this interface (e.g. mechanisms of milk fat globule digestion). PMID:26087463

  13. Thermodynamic analysis of ANS binding to partially unfolded α-lactalbumin: correlation of endothermic to exothermic changeover with formation of authentic molten globules.

    Science.gov (United States)

    Kim, Ki Hyung; Yun, Soi; Mok, K H; Lee, E K

    2016-09-01

    A fluorescent reporter, 8-anilino-1-naphthalene sulfonic acid (ANS), can serve as a reference molecule for conformational transition of a protein because its aromatic carbons have strong affinity with hydrophobic cores of partially unfolded molten globules. Using a typical calcium-binding protein, bovine α-lactalbumin (BLA), as a model protein, we compared the ANS binding thermodynamics to the decalcified (10 mM EDTA treated) apo-BLA at two representative temperatures: 20 and 40 °C. This is because the authentic molten globule is known to form more heavily at an elevated temperature such as 40 °C. Isothermal titration calorimetry experiments revealed that the BLA-ANS interactions at both temperatures were entropy-driven, and the dissociation constants were similar on the order of 10(-4)  M, but there was a dramatic changeover in the binding thermodynamics from endothermic at 20 °C to exothermic at 40 °C. We believe that the higher subpopulation of authentic molten globules at 40 °C than 20 °C would be responsible for the results, which also indicate that weak binding is sufficient to alter the ANS binding mechanisms. We expect that the thermodynamic properties obtained from this study would serve as a useful reference for investigating the binding of other hydrophobic ligands such as oleic acid to apo-BLA, because oleic acid is known to have tumor-selective cytotoxicity when complexed with partially unfolded α-lactalbumin. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27060481

  14. Effect of Lenient Steam Injection (LSI) heat treatment of bovine milk on the activities of some enzymes, the milk fat globule and pH

    DEFF Research Database (Denmark)

    Dickow, Jonathan Ahrens; Thorup Nielsen, Martin; Hammershøj, Marianne

    2012-01-01

    This study investigated the effects of Lenient Steam Injection (LSI) treatment at temperatures 70–150 C on the enzymatic activities of the indigenous milk enzymes alkaline phosphatase, lactoperoxidase (LPO), xanthine oxidase (XO), lipoprotein lipase (LPL) and plasmin in comparison with two...... reference heat treatments of 63 C for 30 s and of 72 C for 15 s by indirect heating. Milk fat globule (MFG) size distributions and pH were also monitored. Alkaline phosphatase, LPO, XO and LPL activities decreased with increasing LSI temperature. Plasmin activity was increased at temperatures <80 C and...

  15. Purification of MUC1 from bovine milk-fat globules and characterization of a corresponding full-length cDNA clone

    DEFF Research Database (Denmark)

    Pallesen, Lone Tjener; Andersen, Mikkel Holmen; Nielsen, Rune L.; Berglund, Lars; Petersen, Torben Ellebæk; Rasmussen, Lone Kjær; Rasmussen, Jan Trige

    2001-01-01

    The highly glycosylated protein MUC1 was purified from bovine milk-fat globule membranes by a procedure involving detergent extraction, ion-exchange chromatography and reverse-phase chromatography. The identity of the purified mucin protein was confirmed by N-terminal sequencing and partial amino...... composition determinations suggested significant structural differences between O-linked glycans of MUC1 originating from either bovine or human milk. Interspecies differences of the consensus repeat sequence in MUC1 and the physiological functions are discussed....

  16. Les structures supramoléculaires du lait : structure et impact nutritionnel de la micelle de caséine et du globule gras

    OpenAIRE

    Michalski, Marie-Caroline; Martin, Patrice

    2013-01-01

    La présence d’une diversité de molécules spécifiques qui coexistent dans le lait sous forme de structures supramoléculaires, telles les micelles de caséine et les globules gras, fait de ce fluide biologique un système extraordinairement complexe, physiquement stable, capable de vectoriser les composés bioactifs présents aussi bien dans sa fraction protéique que dans sa fraction lipidique. Les avancées réalisées tant sur la composition que sur l’organisation structurale de ces structures, même...

  17. Rhodanese functions as sulfur supplier for key enzymes in sulfur energy metabolism.

    Science.gov (United States)

    Aussignargues, Clément; Giuliani, Marie-Cécile; Infossi, Pascale; Lojou, Elisabeth; Guiral, Marianne; Giudici-Orticoni, Marie-Thérèse; Ilbert, Marianne

    2012-06-01

    How microorganisms obtain energy is a challenging topic, and there have been numerous studies on the mechanisms involved. Here, we focus on the energy substrate traffic in the hyperthermophilic bacterium Aquifex aeolicus. This bacterium can use insoluble sulfur as an energy substrate and has an intricate sulfur energy metabolism involving several sulfur-reducing and -oxidizing supercomplexes and enzymes. We demonstrate that the cytoplasmic rhodanese SbdP participates in this sulfur energy metabolism. Rhodaneses are a widespread family of proteins known to transfer sulfur atoms. We show that SbdP has also some unusual characteristics compared with other rhodaneses; it can load a long sulfur chain, and it can interact with more than one partner. Its partners (sulfur reductase and sulfur oxygenase reductase) are key enzymes of the sulfur energy metabolism of A. aeolicus and share the capacity to use long sulfur chains as substrate. We demonstrate a positive effect of SbdP, once loaded with sulfur chains, on sulfur reductase activity, most likely by optimizing substrate uptake. Taken together, these results lead us to propose a physiological role for SbdP as a carrier and sulfur chain donor to these key enzymes, therefore enabling channeling of sulfur substrate in the cell as well as greater efficiency of the sulfur energy metabolism of A. aeolicus. PMID:22496367

  18. Catalytic conversion of sulfur dioxide and trioxide

    Energy Technology Data Exchange (ETDEWEB)

    Solov' eva, E.L.; Shenfel' d, B.E.; Kuznetsova, S.M.; Khludenev, A.G.

    1987-11-10

    The reclamation and utilization of sulfur-containing wastes from the flue gas of fossil-fuel power plants and the subsequent reduction in sulfur emission is addressed in this paper. The authors approach this problem from the standpoint of the catalytic oxidation of sulfur dioxide on solid poison-resistant catalysts with subsequent sorption of the sulfur trioxide and its incorporation into the manufacture of sulfuric acid. The catalyst they propose is a polymetallic dust-like waste from the copper-smelting industry comprised mainly of iron and copper oxides. Experiments with this catalyst were carried out using multifactorial experiment planning.

  19. Bacterial Nail Infection (Paronychia)

    Science.gov (United States)

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

  20. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  1. Hydrophobic photolabeling as a new method for structural characterization of molten globule and related protein folding intermediates.

    Science.gov (United States)

    D'Silva, P. R.; Lala, A. K.

    1999-01-01

    Recent advances in attempts to unravel the protein folding mechanism have indicated the need to identify the folding intermediates. Despite their transient nature, in a number of cases it has been possible to detect and characterize some of the equilibrium intermediates, for example, the molten globule (MG) state. The key features of the MG state are retention of substantial secondary structure of the native state, considerable loss of tertiary structure leading to increased hydrophobic exposure, and a compact structure. NMR, circular dichroism, and fluorescence spectroscopies have been most useful in characterizing such intermediates. We report here a new method for structural characterization of the MG state that involves probing the exposed hydrophobic sites with a hydrophobic photoactivable reagent--2[3H]diazofluorene. This carbene-based reagent binds to hydrophobic sites, and on photolysis covalently attaches itself to the neighboring amino acid side chains. The reagent photolabels alpha-lactalbumin as a function of pH (3-7.4), the labeling at neutral pH being negligible and maximal at pH 3. Chemical and proteolytic fragmentation of the photolabeled protein followed by peptide sequencing permitted identification of the labeled residues. The results obtained indicate that the sequence corresponding to B (23-34) and C (86-98) helix of the native structure are extensively labeled. The small beta-domain (40-50) is poorly labeled, Val42 being the only residue that is significantly labeled. Our data, like NMR data, indicate that in the MG state of alpha-lactalbumin, the alpha-domain has a greater degree of persistent structure than the beta-domain. However, unlike the NMR method, the photolabeling method is not limited by the size of the protein and can provide information on several new residues, for example, Leu115. The current method using DAF thus allows identification of stable and hydrophobic exposed regions in folding intermediates as the reagent binds and on

  2. Corrosion in sulfur recovery units

    Energy Technology Data Exchange (ETDEWEB)

    Fraisse, M.

    1979-06-01

    Corrosion in sulfur recovery units may be caused by sulfuric acid formed at cold points in operating units or during the startup, shutdown, or catalyst regeneration periods. Insufficient high-temperature resistance of main boiler materials to sulfuric acid is another common cause of severe corrosion. The specific corrosion problems encountered in hydrotreating units include high- and low-temperature hydrogen embrittlement of steel above 200/sup 0/C and between -50/sup 0/ and +20/sup 0/C, respectively, sometimes accompanied with blistering; carbon steel corrosion by hydrogen sulfide above 280/sup 0/C in desulfurization units; low-temperature stress corrosion or hydrogen blistering by H/sub 2/S in aqueous environments; corrosion by chloride ions coupled with precipitation of ammonium chloride in catalytic reformers during catalyst regeneration; corrosion and fouling by ammonium sulfide in gas oil hydrodesulfurization units and reformers below 90/sup 0/C; and intergranular and stress corrosion of austenitic steels by polythionic acids which may be formed during startup or catalyst regeneration periods. Methods for preventing these types of corrosion are outlined.

  3. Sulfur geochemistry and microbial sulfate reduction during low-temperature alteration of uplifted lower oceanic crust: Insights from ODP Hole 735B

    Science.gov (United States)

    Alford, Susan E.; Alt, Jeffrey C.; Shanks, Wayne C., III

    2011-01-01

    Sulfide petrography plus whole rock contents and isotope ratios of sulfur were measured in a 1.5 km section of oceanic gabbros in order to understand the geochemistry of sulfur cycling during low-temperature seawater alteration of the lower oceanic crust, and to test whether microbial effects may be present. Most samples have low SO4/ΣS values (≤ 0.15), have retained igneous globules of pyrrhotite ± chalcopyrite ± pentlandite, and host secondary aggregates of pyrrhotite and pyrite laths in smectite ± iron-oxyhydroxide ± magnetite ± calcite pseudomorphs of olivine and clinopyroxene. Compared to fresh gabbro containing 100–1800 ppm sulfur our data indicate an overall addition of sulfide to the lower crust. Selection of samples altered only at temperatures ≤ 110 °C constrains microbial sulfate reduction as the only viable mechanism for the observed sulfide addition, which may have been enabled by the production of H2 from oxidation of associated olivine and pyroxene. The wide range in δ34Ssulfide values (− 1.5 to + 16.3‰) and variable additions of sulfide are explained by variable εsulfate-sulfide under open system pathways, with a possible progression into closed system pathways. Some samples underwent oxidation related to seawater penetration along permeable fault horizons and have lost sulfur, have high SO4/ΣS (≥ 0.46) and variable δ34Ssulfide (0.7 to 16.9‰). Negative δ34Ssulfate–δ34Ssulfide values for the majority of samples indicate kinetic isotope fractionation during oxidation of sulfide minerals. Depth trends in sulfide–sulfur contents and sulfide mineral assemblages indicate a late-stage downward penetration of seawater into the lower 1 km of Hole 735B. Our results show that under appropriate temperature conditions, a subsurface biosphere can persist in the lower oceanic crust and alter its geochemistry.

  4. Genomic analysis reveals versatile heterotrophic capacity of a potentially symbiotic sulfur-oxidizing bacterium in sponge

    KAUST Repository

    Tian, Renmao

    2014-08-29

    Sulfur-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) play essential roles in marine sponges. However, the detailed characteristics and physiology of the bacteria are largely unknown. Here, we present and analyse the first genome of sponge-associated SOB using a recently developed metagenomic binning strategy. The loss of transposase and virulence-associated genes and the maintenance of the ancient polyphosphate glucokinase gene suggested a stabilized SOB genome that might have coevolved with the ancient host during establishment of their association. Exclusive distribution in sponge, bacterial detoxification for the host (sulfide oxidation) and the enrichment for symbiotic characteristics (genes-encoding ankyrin) in the SOB genome supported the bacterial role as an intercellular symbiont. Despite possessing complete autotrophic sulfur oxidation pathways, the bacterium developed a much more versatile capacity for carbohydrate uptake and metabolism, in comparison with its closest relatives (Thioalkalivibrio) and to other representative autotrophs from the same order (Chromatiales). The ability to perform both autotrophic and heterotrophic metabolism likely results from the unstable supply of reduced sulfur in the sponge and is considered critical for the sponge-SOB consortium. Our study provides insights into SOB of sponge-specific clade with thioautotrophic and versatile heterotrophic metabolism relevant to its roles in the micro-environment of the sponge body. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  5. Radiolysis of Sulfuric Acid, Sulfuric Acid Monohydrate, and Sulfuric Acid Tetrahydrate and Its Relevance to Europa

    Science.gov (United States)

    Loeffler, M. J.; Hudson, R. L.; Moore, M. H.; Carlson, R. W.

    2011-01-01

    We report laboratory studies on the 0.8 MeV proton irradiation of ices composed of sulfuric acid (H2SO4), sulfuric acid monohydrate (H2SO4 H2O), and sulfuric acid tetrahydrate (H2SO4 4H2O) between 10 and 180 K. Using infrared spectroscopy, we identify the main radiation products as H2O, SO2, (S2O3)x, H3O+, HSO4(exp -), and SO4(exp 2-). At high radiation doses, we find that H2SO4 molecules are destroyed completely and that H2SO4 H2O is formed on subsequent warming. This hydrate is significantly more stable to radiolytic destruction than pure H2SO4, falling to an equilibrium relative abundance of 50% of its original value on prolonged irradiation. Unlike either pure H2SO4 or H2SO4 H2O, the loss of H2SO4 4H2O exhibits a strong temperature dependence, as the tetrahydrate is essentially unchanged at the highest irradiation temperatures and completely destroyed at the lowest ones, which we speculate is due to a combination of radiolytic destruction and amorphization. Furthermore, at the lower temperatures it is clear that irradiation causes the tetrahydrate spectrum to transition to one that closely resembles the monohydrate spectrum. Extrapolating our results to Europa s surface, we speculate that the variations in SO2 concentrations observed in the chaotic terrains are a result of radiation processing of lower hydration states of sulfuric acid and that the monohydrate will remain stable on the surface over geological times, while the tetrahydrate will remain stable in the warmer regions but be destroyed in the colder regions, unless it can be reformed by other processes, such as thermal reactions induced by diurnal cycling.

  6. Effect of different sulfur levels from various sources on brassica napus growth and soil sulfur fractions

    International Nuclear Information System (INIS)

    A two year field study was conducted at two different locations in northern rain fed Punjab, Pakistan to assess the effect of different rates of sulfur application from various sources on soil sulfur fractions and growth of Brassica napus. The treatments included three sulfur sources i. e., single super phosphate, ammonium sulfate and gypsum each applied at five different rates (0, 10, 20, 30 and 40 kg S ha/sup -1/ ). Sulfur application had a significant positive effect on the growth and yield parameters of Brassica napus. Among the sulfur sources ammonium sulfate resulted in maximum increase in plant growth and yield parameters, followed by single super phosphate. Sulfur content and uptake by crop plants was significantly higher with ammonium sulfate application as compared to other two sulfur sources. Sulfur application also exerted a significant positive effect on different S fractions in the soils. On an average, 18.0% of the applied sulfur got incorporated into CaCl/sub 2/ extractable sulfur fraction, while 15.6% and 35.5% entered into adsorbed and organic sulfur fractions in the soils, respectively. The value cost ratio increased significantly by sulfur application up to 30 kg ha/sup -1/. Among sulfur sources, ammonium sulfate performed best giving the highest net return. (author)

  7. Acidithiobacillus caldus Sulfur Oxidation Model Based on Transcriptome Analysis between the Wild Type and Sulfur Oxygenase Reductase Defective Mutant

    OpenAIRE

    Linxu Chen; Yilin Ren; Jianqun Lin; Xiangmei Liu; Xin Pang; Jianqiang Lin

    2012-01-01

    BACKGROUND: Acidithiobacillus caldus (A. caldus) is widely used in bio-leaching. It gains energy and electrons from oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs) for carbon dioxide fixation and growth. Genomic analyses suggest that its sulfur oxidation system involves a truncated sulfur oxidation (Sox) system (omitting SoxCD), non-Sox sulfur oxidation system similar to the sulfur oxidation in A. ferrooxidans, and sulfur oxygenase reductase (SOR). The complexity ...

  8. Wound Healing of Cutaneous Sulfur Mustard Injuries

    OpenAIRE

    Graham, John S.; Chilcott, Robert P.; Rice, Paul; Milner, Stephen M.; Hurst, Charles G.; Maliner, Beverly I.

    2005-01-01

    Sulfur mustard is an alkylating chemical warfare agent that primarily affects the eyes, skin, and airways. Sulfur mustard injuries can take several months to heal, necessitate lengthy hospitalizations, and result in significant cosmetic and/or functional deficits. Historically, blister aspiration and/or deroofing (epidermal removal), physical debridement, irrigation, topical antibiotics, and sterile dressings have been the main courses of action in the medical management of cutaneous sulfur m...

  9. Thiophenic Sulfur Compounds Released During Coal Pyrolysis.

    Science.gov (United States)

    Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

    2013-06-01

    Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography-mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

  10. Reduced sulfur compound oxidation by Thiobacillus caldus.

    OpenAIRE

    Hallberg, K. B.; Dopson, M; Lindström, E B

    1996-01-01

    The oxidation of reduced inorganic sulfur compounds was studied by using resting cells of the moderate thermophile Thiobacillus caldus strain KU. The oxygen consumption rate and total oxygen consumed were determined for the reduced sulfur compounds thiosulfate, tetrathionate, sulfur, sulfide, and sulfite in the absence and in the presence of inhibitors and uncouplers. The uncouplers 2,4-dinitrophenol and carbonyl cyanide m-chlorophenyl-hydrazone had no affect on the oxidation of thiosulfate, ...

  11. Sulfur transformations in early diagenetic sediments from the Bay of Concepcion, off Chile

    Energy Technology Data Exchange (ETDEWEB)

    Vairavamurth, M.A.; Wang, Shengke; Khandelwal, B.; Manowitz, B. [Brookhaven National Lab., Upton, NY (United States); Ferdelman, T.; Fossing, H. [Max Plank Institute for Marine Microbiology, Bremen (Germany). Dept. of Biogeochemistry

    1995-04-01

    Despite the recognition that both organic sulfur and pyrite form during the very early stages of diagenesis, and that the amount of H{sub 2}S generated in bacterial sulfate reduction primarily limits their formation, the mechanisms and the active species involved still are not clear. In this study, we quantified the major forms of sulfur distributed in sediments to assess the geochemical mechanisms involved in these transformations. XANES spectroscopy, together with elemental analysis, were used to measure sulfur speciation in the organic-rich sediments from the Bay of Concepcion, Chile. Organic polysulfides constituted the major fraction of the organic sulfur, and occurred maximally just below the sediment surface (1--3 cm), where intermediates from H{sub 2}S oxidation were likely to be generated most abundantly. Sulfonates, which could be formed through the reactions of sulfate and thiosulfate, also showed a sub-surface maximum in the vicinity of the ``oxic-anoxic interface``. These results strongly suggest a geochemical origin for organic polysulfides and sulfonates, and illustrate that intermediates from H{sub 2}S oxidation play a dominant role in incorporating sulfur into organic matter. Pyrite was absent in the surficial layer, and first appeared just below the H{sub 2}S maximum, where organic polysulfides began to decrease in abundance. From these results, we argue, that an iron monosulfide precursor formed first from reactions with H{sub 2}S, and then reacts with organic polysulfides, completing the synthesis of pyrite in the sediment column.

  12. Are the clouds of Venus sulfuric acid.

    Science.gov (United States)

    Young, A. T.

    1973-01-01

    It is shown that strong aqueous sulfuric acid solutions have the right refractive index and freeze at Venusian cloud temperature, explain the dryness of the Venusian stratosphere, are consistent with some features of the Venusian IR spectrum, and do not absorb in highly reflecting areas of Venus. It is also indicated that such solutions should be produced by reactions between known atmospheric constituents and most sulfur-bearing rock at the Venusian surface temperature, and require only small amounts of sulfur consistent with its cosmic abundance and with the amounts of other volatile elements present in the atmosphere. It is believed therefore that the clouds of Venus consist of sulfuric acid solutions.

  13. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

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

  14. Demonstrating Bacterial Flagella.

    Science.gov (United States)

    Porter, John R.; And Others

    1992-01-01

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

  15. Dimethylsulfoniopropionate in corals and its interrelations with bacterial assemblages in coral surface mucus

    NARCIS (Netherlands)

    Frade, P.R.; Schwaninger, V.; Glasl, B.; Sintes, E.; Hill, R.W.; Simó, R.; Herndl, G.

    2016-01-01

    Corals produce copious amounts of dimethylsulfoniopropionate (DMSP), a sulfur compound thought toplay a role in structuring coral-associated bacterial communities. We tested the hypothesis that a linkage exists betweenDMSP availability in coral tissues and the community dynamics of bacteria in coral

  16. Sulfur-carbon nanocomposites and their application as cathode materials in lithium-sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chengdu; Dudney, Nancy J; Howe, Jane Y

    2015-05-05

    The invention is directed in a first aspect to a sulfur-carbon composite material comprising: (i) a bimodal porous carbon component containing therein a first mode of pores which are mesopores, and a second mode of pores which are micropores; and (ii) elemental sulfur contained in at least a portion of said micropores. The invention is also directed to the aforesaid sulfur-carbon composite as a layer on a current collector material; a lithium ion battery containing the sulfur-carbon composite in a cathode therein; as well as a method for preparing the sulfur-composite material.

  17. Biological sulfuric acid transformation: Reactor design and process optimization.

    Science.gov (United States)

    Stucki, G; Hanselmann, K W; Hürzeler, R A

    1993-02-01

    As an alternative to the current disposal technologies for waste sulfuric acid, a new combination of recycling processes was developed. The strong acid (H(2)SO(4)) is biologically converted with the weak acid (CH(3)COOH) into two volatile weak acids (H(2)S, H(2)CO(3)) by sulfate-reducing bacteria. The transformation is possible without prior neutralization of the sulfuric acid. The microbially mediated transformation can be followed by physiochemical processes for the further conversion of the H(2)S.The reduction of sulfate to H(2)S is carried out under carbon-limited conditions at pH 7.5 to 8.5. A fixed-bed biofilm column reactor is used in conjunction with a separate gas-stripping column which was installed in the recycle stream. Sulfate, total sulfide, and the carbon substrate (in most cases acetate) were determined quantitatively. H(2)S and CO(2) are continually removed by stripping with N(2). Optimal removal is achieved under pH conditions which are adjusted to values below the pK(a)-values of the acids. The H(2)S concentration in the stripped gas was 2% to 8% (v/v) if H(2)SO(4) and CH(3)COOH are fed to the recycle stream just before the stripping column.Microbiol conversion rates of 65 g of sulfate reduced per liter of bioreactor volume per day are achieved and bacterial conversion efficiencies for sulfate of more than 95% can be maintained if the concentration of undissociated H(2)S is kept below 40 to 50 mg/L. Porous glass spheres, lava beads, and polyurethane pellets are useful matrices for the attachment of the bacterial biomass. Theoretical aspects and the dependence of the overall conversion performance on selected process parameters are illustrated in the Appendix to this article. PMID:18609554

  18. Dimethylmercury Formation Mediated by Inorganic and Organic Reduced Sulfur Surfaces

    Science.gov (United States)

    Jonsson, Sofi; Mazrui, Nashaat M.; Mason, Robert P.

    2016-06-01

    Underlying formation pathways of dimethylmercury ((CH3)2Hg) in the ocean are unknown. Early work proposed reactions of inorganic Hg (HgII) with methyl cobalamin or of dissolved monomethylmercury (CH3Hg) with hydrogen sulfide as possible bacterial mediated or abiotic pathways. A significant fraction (up to 90%) of CH3Hg in natural waters is however adsorbed to reduced sulfur groups on mineral or organic surfaces. We show that binding of CH3Hg to such reactive sites facilitates the formation of (CH3)2Hg by degradation of the adsorbed CH3Hg. We demonstrate that the reaction can be mediated by different sulfide minerals, as well as by dithiols suggesting that e.g. reduced sulfur groups on mineral particles or on protein surfaces could mediate the reaction. The observed fraction of CH3Hg methylated on sulfide mineral surfaces exceeded previously observed methylation rates of CH3Hg to (CH3)2Hg in seawaters and we suggest the pathway demonstrated here could account for much of the (CH3)2Hg found in the ocean.

  19. Sulfuric Acid and Water: Paradoxes of Dilution

    Science.gov (United States)

    Leenson, I. A.

    2004-01-01

    On equilibrium properties of aqueous solutions of sulfuric acid, Julius Thomsen has marked that the heat evolved on diluting liquid sulfuric acid with water is a continuous function of the water used, and excluded absolutely the acceptance of definite hydrates as existing in the solution. Information about thermochemical measurement, a discussion…

  20. 46 CFR 153.1046 - Sulfuric acid.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 153.1046 Section 153.1046 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may...

  1. Sulfur oxide adsorbents and emissions control

    Science.gov (United States)

    Li, Liyu; King, David L.

    2006-12-26

    High capacity sulfur oxide absorbents utilizing manganese-based octahedral molecular sieve (Mn--OMS) materials are disclosed. An emissions reduction system for a combustion exhaust includes a scrubber 24 containing these high capacity sulfur oxide absorbents located upstream from a NOX filter 26 or particulate trap.

  2. Shuffling bacterial metabolomes

    OpenAIRE

    Thomason, Brendan; Read, Timothy D.

    2006-01-01

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

  3. Vimentin in Bacterial Infections.

    Science.gov (United States)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

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

  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 ...... become valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  5. 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.

  6. Hydrolysis of bovine and caprine milk fat globules by lipoprotein lipase. Effects of heparin and skim milk on lipase distribution and on lipolysis

    Energy Technology Data Exchange (ETDEWEB)

    Sundheim, G.; Bengtsson-Olivecrona, G.

    1987-12-01

    Heparin can dissociate lipoprotein lipase from casein micelles, and addition of heparin enhances lipolysis in bovine but not in caprine milk. Heparin shortened the lag-time for binding of lipoprotein lipase to milk fat globules and for lipolysis. Heparin counteracted the inhibitory effects of skim milk on binding of lipase and on lipolysis. Heparin stimulated lipolysis in all bovine milk samples when added before cooling and in spontaneously lipolytic milk samples also when added after cooling. Heparin enhanced lipolysis of isolated milk fat globules. Hence, its effect is not solely due to dissociation of lipoprotein lipase from the casein micelles. Cooling of goat milk caused more marked changes in the distribution of lipase than cooling of bovine milk; the fraction of added /sup 125/I-labeled lipase that bound to cream increased from about 8 to 60%. In addition, caprine skim milk caused less inhibition of lipolysis than bovine skim milk. These observations provide an explanation for the high degree of cold storage lipolysis in goat milk. Heparin had only small effects on the distribution of lipoprotein lipase in caprine milk, which explains why heparin has so little effect on lipolysis in caprine milk. The distribution of /sup 35/S-labeled heparin in bovine milk was studied. In warm milk less than 10% bound to the cream fraction, but when milk was cooled, binding of heparin to cream increased to 45%. These results suggest that there exists in the skim fraction a relatively small amount of a heparin-binding protein, which on cooling of milk adsorbs to the milk fat, or suggests that cooling induces a conformational change in a membrane protein such that its affinity for heparin increases.

  7. Hydrolysis of bovine and caprine milk fat globules by lipoprotein lipase. Effects of heparin and skim milk on lipase distribution and on lipolysis

    International Nuclear Information System (INIS)

    Heparin can dissociate lipoprotein lipase from casein micelles, and addition of heparin enhances lipolysis in bovine but not in caprine milk. Heparin shortened the lag-time for binding of lipoprotein lipase to milk fat globules and for lipolysis. Heparin counteracted the inhibitory effects of skim milk on binding of lipase and on lipolysis. Heparin stimulated lipolysis in all bovine milk samples when added before cooling and in spontaneously lipolytic milk samples also when added after cooling. Heparin enhanced lipolysis of isolated milk fat globules. Hence, its effect is not solely due to dissociation of lipoprotein lipase from the casein micelles. Cooling of goat milk caused more marked changes in the distribution of lipase than cooling of bovine milk; the fraction of added 125I-labeled lipase that bound to cream increased from about 8 to 60%. In addition, caprine skim milk caused less inhibition of lipolysis than bovine skim milk. These observations provide an explanation for the high degree of cold storage lipolysis in goat milk. Heparin had only small effects on the distribution of lipoprotein lipase in caprine milk, which explains why heparin has so little effect on lipolysis in caprine milk. The distribution of 35S-labeled heparin in bovine milk was studied. In warm milk less than 10% bound to the cream fraction, but when milk was cooled, binding of heparin to cream increased to 45%. These results suggest that there exists in the skim fraction a relatively small amount of a heparin-binding protein, which on cooling of milk adsorbs to the milk fat, or suggests that cooling induces a conformational change in a membrane protein such that its affinity for heparin increases

  8. Preparation and characterization of bacterial cellulose nano crystals; Preparacao e caracterizacao de nanocristais de celulose bacteriana

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Daniele B. dos; Lima, Lais R. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L. [Universidade Estadual Paulista Julio de Mesquita Filho. Unesp, Instituto de Quimica, Araraquara, SP (Brazil)

    2011-07-01

    In this work we described the preparation of bacterial cellulose nano crystals (BCNC) by hydrolysis of bacterial cellulose with concentrated sulfuric acid. The influence of hydrolysis time in the nano crystals formation was evaluated and the materials characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TG) and X-ray diffraction analysis. The SEM images showed the whiskers formation and its reveal that the morphology and size of BCNC not changes significantly with hydrolysis time. The X-rays diffractogram analysis showed an increase on BCNC crystallinity as compared with pure bacterial cellulose. The TG curves revealed a decreasing on thermal stability of BCNC samples with increase of the hydrolysis time. (author)

  9. Multiple-heteroatom-containing sulfur compounds in a high sulfur coal

    International Nuclear Information System (INIS)

    Flash vacuum pyrolysis of a high sulfur coal has been combined with high resolution mass spectrometry yielding information on aromatic sulfur compounds containing an additional heteroatom. Sulfur emission from coal utilization is a critical problem and in order to devise efficient methods for removing organic sulfur, it is important to know what types of molecules contain sulfur. A high sulfur Illinois No. 6 bituminous coal (Argonne Premium Coal Sample No. 3) was pyrolyzed on a platinum grid using a quartz probe inserted into a modified all glass heated inlet system and the products characterized by high resolution mass spectrometry (HRMS). A significant number of products were observed which contained both sulfur and an additional heteroatom. In some cases two additional heteroatoms were observed. These results are compared to those found in coal extracts and liquefaction products

  10. Effect of Additive on Sulfur-fixation Process of Sulfur-fixation Agent

    Institute of Scientific and Technical Information of China (English)

    XIE Jun-lin; QIU Jian-rong; ZHAO Gai-ju; LOU Jin-ping; HAN Chun-hua

    2003-01-01

    The crystallization behavior of desulfurization product is directly related to its high-temperatureresistant ability. Effects of the additive on the sulfur-fixation efficiency of the Ba-sulfur-fixation agent and also on the crystallization behavior of the sulfur-fixation product were studied when CaCO3 and BaCO3 were used as the desulfurization agent and MgO and SrCO3 used as the assistant sulfur-fixation agent. The result shows that increase of sulfur-fixation capability for the additive is not owe to their directly react to form sulfate or interact with CaCO3 and BaCO3 to form composite mineral heat-resistant in high temperature, but owe to their activation to sulfur-fixation reaction of the sulfur-fixation agent.

  11. Sulfur's price collapse to force market changes

    International Nuclear Information System (INIS)

    Price drops for sulfur over the past 2 years of 50-66% at most major consuming locations are prompting a major industry restructuring, according to Fertecon, a U.K.-based research organization that follows worldwide sulfur production for the fertilizer industry. A recently completed Fertecon study of the cost of producing and marketing sulfur indicates that the attrition in worldwide sulfur-mining capacity has now mostly run its course. Moreover, the burden of balancing the market will fall firmly on major producers of sulfur in the sour-gas industry, especially Canada. The paper discusses supply and demand realities, regional analysis, the role of sour gas, and the outlook for the future

  12. "Immunobiological Consequences of Sulfur Mustard Contamination "

    Directory of Open Access Journals (Sweden)

    Zuhair Mohammad Hassan

    2006-09-01

    Full Text Available Sulfur mustard has been employed in chemical warfare in certain regions including Iran. The short and long term biological effects of sulfur mustard contamination have been studied in both basic and clinical aspects. Sulfur mustard has been shown to induce a vast array of pathological effects in affected persons. In addition to skin, lung, eyes and gastrointestinal disturbances, sulfur mustard has been shown to induce hematological complications and a severe suppression of the immune system. The short and long term immunological (both cellular and humoral, hematological, genetic and biochemical consequences of persons exposed to sulfur mustard are extensively reviewed here. The long term complications of these patients indicate the need to develop effective preventive and therapeutic strategies in the clinic. These strategies may be based upon immunopotentiating intervention and therapy.

  13. Succession of Sulfur-Oxidizing Bacteria in the Microbial Community on Corroding Concrete in Sewer Systems† ▿

    OpenAIRE

    Okabe, Satoshi; Odagiri, Mitsunori; Ito, Tsukasa; Satoh, Hisashi

    2007-01-01

    Microbially induced concrete corrosion (MICC) in sewer systems has been a serious problem for a long time. A better understanding of the succession of microbial community members responsible for the production of sulfuric acid is essential for the efficient control of MICC. In this study, the succession of sulfur-oxidizing bacteria (SOB) in the bacterial community on corroding concrete in a sewer system in situ was investigated over 1 year by culture-independent 16S rRNA gene-based molecular ...

  14. Single-taxon field measurements of bacterial gene regulation controlling DMSP fate.

    Science.gov (United States)

    Varaljay, Vanessa A; Robidart, Julie; Preston, Christina M; Gifford, Scott M; Durham, Bryndan P; Burns, Andrew S; Ryan, John P; Marin, Roman; Kiene, Ronald P; Zehr, Jonathan P; Scholin, Christopher A; Moran, Mary Ann

    2015-07-01

    The 'bacterial switch' is a proposed regulatory point in the global sulfur cycle that routes dimethylsulfoniopropionate (DMSP) to two fundamentally different fates in seawater through genes encoding either the cleavage or demethylation pathway, and affects the flux of volatile sulfur from ocean surface waters to the atmosphere. Yet which ecological or physiological factors might control the bacterial switch remains a topic of considerable debate. Here we report the first field observations of dynamic changes in expression of DMSP pathway genes by a single marine bacterial species in its natural environment. Detection of taxon-specific gene expression in Roseobacter species HTCC2255 during a month-long deployment of an autonomous ocean sensor in Monterey Bay, CA captured in situ regulation of the first gene in each DMSP pathway (dddP and dmdA) that corresponded with shifts in the taxonomy of the phytoplankton community. Expression of the demethylation pathway was relatively greater during a high-DMSP-producing dinoflagellate bloom, and expression of the cleavage pathway was greater in the presence of a mixed diatom and dinoflagellate community [corrected].These field data fit the prevailing hypothesis for bacterial DMSP gene regulation based on bacterial sulfur demand, but also suggest a modification involving oxidative stress response, evidenced as upregulation of catalase via katG, when DMSP is demethylated. PMID:25700338

  15. Characterization of extracellular polymeric substances in the biofilms of typical bacteria by the sulfur K-edge XANES spectroscopy.

    Science.gov (United States)

    Lin, Huirong; Ye, Chengsong; Lv, Lu; Zheng, Clark Renjun; Zhang, Shenghua; Zheng, Lei; Zhao, Yidong; Yu, Xin

    2014-08-01

    A combined approach of physicochemical extraction and sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy was applied to characterize the extracellular polymeric substances (EPS) of typical bacterial biofilms in this study. Physicochemical analysis showed variation of the contents of DNA, polysaccharide and protein in different fractions of EPS in different mediums. The sulfur K-edge XANES analysis yielded a variety of spectra. Spectral fitting of the XANES spectra utilizing a large set of model compounds showed that there was more reduced sulfur in both LB-EPS (loosely bound EPS) and TB-EPS (tightly bound EPS) of all the biofilms in LB medium than in R2A medium. More oxidized sulfur was identified in LB-EPS than that in TB-EPS, suggesting different niches and physiological heterogeneity in the biofilms. Our results suggested that the sulfur K-edge XANES can be a useful tool to analyze the sulfur speciation in EPS of biofilms. PMID:25108733

  16. Mineral composition and geochemistry of rocks with bacterial overgrowths from submarine hydrothermal structures

    Science.gov (United States)

    Lein, A. Iu.; Gal'Chenko, V. F.; Grinenko, V. A.; Ul'Ianova, N. V.; Voropaev, A. V.

    1988-09-01

    Samples of hydrothermal rocks with bacterial overgrowths obtained from the rift zones of the Juan de Fuca Ridge and the Guaymas Trough were analyzed for mineral and elemental compositions. Two types of overgrowth on the rocks at the outlets of hydrosulfide and hydrocarbon springs were identified, the former with a predominance of sulfur-cycle bacteria and the latter with a predominance of carbon-cycle bacteria. It is noted that bacterial overgrowths were found on rocks which contained less than 10-15 percent metal sulfides; no bacterial overgrowths were found on massive sulfide-ore rocks. On the basis of geochemical and S-34 analyses, it is concluded that the source of the sulfur in the H2S of hydrothermal waters in these rift zones is basaltic rocks.

  17. A mesoporous carbon–sulfur composite as cathode material for high rate lithium sulfur batteries

    International Nuclear Information System (INIS)

    Highlights: • CMK-3 mesoporous carbon was synthesized as conducting reservoir for housing sulfur. • Sulfur/CMK-3 composites were prepared by two-stage thermal treatment. • The composite at 300 °C for 20 h shows improved electrochemical properties. - Abstract: Sulfur composite was prepared by encapsulating sulfur into CMK-3 mesoporous carbon with different heating times and then used as the cathode material for lithium sulfur batteries. Thermal treatment at 300 °C plays an important role in the sulfur encapsulation process. With 20 h of heating time, a portion of sulfur remained on the surface of carbon, whereas with 60 h of heating time, sulfur is confined deeply in the small pores of carbon that cannot be fully exploited in the redox reaction, thus causing low capacity. The S/CMK-3 composite with thermal treatment for 40 h at 300 °C contained 51.3 wt.% sulfur and delivered a high initial capacity of 1375 mA h g−1 at 0.1 C. Moreover, it showed good capacity retention of 704 mA h g−1 at 0.1 C and 578 mA h g−1 at 2 C even after 100 cycles, which proves its potential as a cathode material for high capability lithium sulfur batteries

  18. Preparation of lamellar carbon matrix for sulfur as cathode material of lithium-sulfur batteries

    International Nuclear Information System (INIS)

    Sulfur is a promising cathode material for lithium batteries as it has high theoretical specific capacity and low cost. However, practical electrochemical performance of lithium-sulfur batteries needs to be improved. In this work, a new method is described to prepare carbon matrix for sulfur to improve electrochemical properties of sulfur electrodes. The carbon matrix is prepared by deoxidizing carbon precursor synthesized by carbonizing sucrose with concentrated sulfuric acid. Carbon matrix-sulfur composite has been characterized by scanning electron microscopy, transmission electron microscopy and Fourier transform infrared. Results indicate that carbon matrix-sulfur composite is composed of lamellas. The lamella contains a layer of carbon coating on the outside and chemical bonds of C-S. The formation of C-S bonds is promoted by deoxidizing carbon precursor. The carbon matrix-sulfur electrode exhibits improved discharge properties, which results from the appropriate structure. Carbon coating and C-S bonds confine sulfur and maintain contact between sulfur species and conductive carbon matrix

  19. 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.

  20. Support for an anaerobic sulfur cycle in two Canadian peatland soils

    Science.gov (United States)

    Blodau, Christian; Mayer, Bernhard; Peiffer, Stefan; Moore, Tim R.

    2007-06-01

    Sulfur cycling in peatlands may affect global CH4 emissions by suppression of methanogenesis through bacterial sulfate reduction (BSR). We sought evidence for anaerobic sulfur cycling in four peat mesocosms irrigated with sulfate at a loading of 0.8 and 3.3 g S m-2 yr-1. To this end we obtained concentration profiles of dissolved O2, C, S, and Fe, and determined 34S/32S ratios of sulfate, reduced inorganic sulfur (TRIS), and total sulfur. To estimate the importance of BSR for anaerobic respiration, peat was incubated with molybdate as inhibitor of BSR. In the mesocosms, pore water concentrations of dissolved sulfate and H2S adjusted to 5-20 μmol L-1 and 0-9 μmol L-1, respectively, whereas concentrations of CO2, CH4, and DOC reached millimolar levels. CO2 production was not explained by methanogenesis and net reduction of inorganic electron acceptors. In the shallow peat, H2S was produced and 34S in sulfate enriched by 3.6 to 6‰, indicating occurrence of BSR. Sulfate reducers also accounted for much of the metabolic activity. Addition of molybdate suppressed CO2 production by 20 to 50%. Deeper into the peat, the sulfate pool was apparently replenished from the peat matrix as sulfate became enriched in 32S, likely stemming from TRIS or organic sulfur in the peat. Sulfur was thus anaerobically cycled between oxidized and reduced pools. An electron acceptor capable of driving this cycle could not be conclusively identified. Regardless of this uncertainty, the results suggest that anaerobic S cycling can maintain BSR and potentially contribute to low methane production in soils of ombrotrophic bogs.

  1. Investigation of sugar sulfur carrier in nickel

    International Nuclear Information System (INIS)

    For the purposes of galvanotechnics it is necessary to have nickel which is easely subjected to the anode dissolving (the so called depolarized nickel). In the industry, nickel of such a quality is produced by the method of electrolytic sedimentation from the nickel solution in the presence of sulfur carriers, usually in the presence of saccharin. To study behaviour of saccharin in the process of electrolysis, investigations of saccharin labelled by sulfur-35 have been done. These investigations have permitted to determine the type and quantity of products of decomposition formed, as well as to determine possibilities for rising the quantity of introducer sulfur due to the variants of technological process

  2. Study of a bacterial leaching program for uranium ores by Thiobacillus ferroxidans

    International Nuclear Information System (INIS)

    The development of a bacterial leaching program for uranium ores is studied. Three basic points are presented: isolation and purification of Thiobacillus ferroxidans, as well Thiobacillus thio oxidans; physiological studies of growth and respiratory metabolism of T. ferroxidans; uranium leaching from two types of ore by T. ferroxidans action, on laboratory, semi pilot and pilot scales. The bacterial leaching studies were carried out in shake flasks, percolation columns (laboratory and semi pilot) and in heap leaching (pilot). The potential of the ores studied in relation to bacterial action, was first showed in shake flask experiments. The production of H2 S O4 and Fe3+ was a result of the bacterial activity on both ore samples containing pyrite (Fe S2). These two bacterial products resulted in a high uranium and molybdenum extraction and a lower sulfuric acid consumption compared to the sterilized treatments. Similar results were obtained in percolation column at the same scale (lab). (author)

  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 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.

  5. Calibrating bacterial evolution

    OpenAIRE

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

    1999-01-01

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

  6. A Carbon-Sulfur Hybrid with Pomegranate-like Structure for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Shi, Yanting; Lv, Wei; Niu, Shuzhang; He, Yanbing; Zhou, Guangmin; Chen, Guohua; Li, Baohua; Yang, Quan-Hong; Kang, Feiyu

    2016-05-01

    A carbon-sulfur hybrid with pomegranate-like core-shell structure, which demonstrates a high rate performance and relatively high cyclic stability, is obtained through carbonization of a carbon precursor in the presence of a sulfur precursor (FeS2 ) and a following oxidation of FeS2 to sulfur by HNO3 . Such a structure effectively protects the sulfur and leaves enough buffer space after Fe(3+) removal and, at the same time, has an interconnected conductive network. The capacity of the obtained hybrid is 450 mA h g(-1) under the current density of 5 C. This work provides a simple strategy to design and prepare various high-performance carbon-sulfur hybrids for lithium-sulfur batteries. PMID:26918663

  7. Sulfurized carbon: a class of cathode materials for high performance lithium/sulfur batteries

    Directory of Open Access Journals (Sweden)

    Sheng S. Zhang

    2013-12-01

    Full Text Available Liquid electrolyte lithium/sulfur (Li/S batteries cannot come into practical applications because of many problems such as low energy efficiency, short cycle life, and fast self-discharge. All these problems are related to the dissolution of lithium polysulfide, a series of sulfur reduction intermediates, in the liquid electrolyte, and resulting parasitic reactions with the Li anode. Covalently binding sulfur onto carbon surface is a solution to completely eliminate the dissolution of lithium polysulfide and make the Li/S battery viable for practical applications. This can be achieved by replacing elemental sulfur with sulfurized carbon as the cathode material. This article reviews the current efforts on this subject and discusses the syntheses, electrochemical properties, and prospects of the sulfurized carbon as a cathode material in the rechargeable Li/S batteries.

  8. Sulfur Isotopic Characteristics of Coal in China and Sulfur Isotopic Fractionation during Coal—burning Process

    Institute of Scientific and Technical Information of China (English)

    洪业汤; 张鸿斌; 等

    1993-01-01

    The determined results of the sulfur contents and isotopic composition of coal samples from major coal mines in 15 provinces and regions of China show that the coal mined in the north of China is characterized by higher 34S and lower sulfur content, but that in the south of China has lower 34S and higher sulfur content.During the coal-burning process in both indrstrial and daily use of coal as fuel the released sulfur dioxide is always enriched in lighter sulfur isotope relative to the corresponding coal;the particles are always enriched in heavier sulfur isotope.The discussion on the environmental geochemical significance of the above-mentioned results also has been made.

  9. Sulfur turnover and emissions during storage of cattle slurry

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Andersen, Astrid J; Poulsen, Henrik Vestergaard;

    2012-01-01

    Slurry acidification using sulfuric acid reduces ammonia emissions but also affects sulfur (S) cycling. Emission of sulfur is a source of malodor and reduces the sulfur fertilizer value of the slurry. We investigated the effect of sulfate and methionine amendments, alone or in combination with ac...

  10. 46 CFR 151.50-21 - Sulfuric acid.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfuric acid. 151.50-21 Section 151.50-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-21 Sulfuric acid. (a) How sulfuric acid may be carried. (1) Sulfuric acid...

  11. Geochemical and cosmochemical cycles involving sulfur, sulfide, sulfite, and sulfate

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, B.; Peter, L.; Ospina, M.

    1979-09-01

    Raman spectra of aqueous systems containing sulfur dioxide, elemental sulfur and sulfate indicate that the equilibrium between these species is catalyzed by elemental sulfur. Therefore, dynamic equilibrium can be expected under conditions prevalent on Venus, on Io and in epigenic sulfur deposits.

  12. Environmental behavior and analysis of agricultural sulfur.

    Science.gov (United States)

    Griffith, Corey M; Woodrow, James E; Seiber, James N

    2015-11-01

    Sulfur has been widely used for centuries as a staple for pest and disease management in agriculture. Presently, it is the largest-volume pesticide in use worldwide. This review describes the sources and recovery methods for sulfur, its allotropic forms and properties and its agricultural uses, including development and potential advantages of nanosulfur as a fungicide. Chemical and microbial reactivity, interactions in soil and water and analytical methods for determination in environmental samples and foodstuffs, including inexpensive analytical methods for sulfur residues in wine, beer and other food/beverage substrates, will be reviewed. The toxicology of sulfur towards humans and agriculturally important fungi is included, with some restrictions on use to promote safety. The review concludes with areas for which more research is warranted. PMID:26108794

  13. Efficient Electrolytes for Lithium-Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Natarajan eAngulakshmi

    2015-05-01

    Full Text Available This review article mainly encompasses on the state-of-the-art electrolytes for lithium–sulfur batteries. Different strategies have been employed to address the issues of lithium-sulfur batteries across the world. One among them is identification of electrolytes and optimization of their properties for the applications in lithium-sulfur batteries. The electrolytes for lithium-sulfur batteries are broadly classified as (i non-aqueous liquid electrolytes, (ii ionic liquids, (iii solid polymer and (iv glass-ceramic electrolytes. This article presents the properties, advantages and limitations of each type of electrolytes. Also the importance of electrolyte additives on the electrochemical performance of Li-S cells is discussed.

  14. ROE Total Sulfur Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of sulfur in kilograms per hectare from 1989 to 1991 at a set of point locations across the...

  15. Protected Sulfur Cathode with Mixed Conductive Coating Layer for Lithium Sulfur Battery

    Science.gov (United States)

    Jin, Jun; Wen, Zhaoyin; Wang, Qingsong; Gu, Sui; Huang, Xiao; Chen, Chunhua

    2016-08-01

    A mixed conductive coating layer composed of lithium ion conductive ceramic powder, carbon and binder was introduced on the surface of a sulfur electrode. This coating layer is designed to suppress the migration of lithium polysulfides from the sulfur electrode, and improve the cycling capacity of a lithium sulfur battery. The protected sulfur cathode with a mixed conductive coating layer delivered an initial specific capacity of 1236 mAh g-1 at 0.5C and maintained a capacity of 842 mAh g-1 after 100 cycles. In particular, a soft package battery with protected cathode exhibits improved cycling capacity and excellent rate performance.

  16. The Biogeochemistry of Sulfur in Hydrothermal Systems

    Science.gov (United States)

    Schulte, Mitchell; Rogers, K. L.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    The incorporation of sulfur into many biomolecules likely dates back to the development of the earliest metabolic strategies. Sulfur is common in enzymes and co-enzymes and is an indispensable structural component in many peptides and proteins. Early metabolism may have been heavily influenced by the abundance of sulfide minerals in hydrothermal systems. The incorporation of sulfur into many biomolecules likely dates back to the development of the earliest metabolic strategies. Sulfur is common in enzymes and co-enzymes and is an indispensable structural component in many peptides and proteins. Early metabolism may have been heavily influenced by the abundance of sulfide minerals in hydrothermal systems. Understanding how sulfur became prevalent in biochemical processes and many biomolecules requires knowledge of the reaction properties of sulfur-bearing compounds. We have previously estimated thermodynamic data for thiols, the simplest organic sulfur compounds, at elevated temperatures and pressures. If life began in hydrothermal environments, it is especially important to understand reactions at elevated temperatures among sulfur-bearing compounds and other organic molecules essential for the origin and persistence of life. Here we examine reactions that may have formed amino acids with thiols as reaction intermediates in hypothetical early Earth hydrothermal environments. (There are two amino acids, cysteine and methionine, that contain sulfur.) Our calculations suggest that significant amounts of some amino acids were produced in early Earth hydrothermal fluids, given reasonable concentrations H2, NH3, H2S and CO. For example, preliminary results indicate that glycine activities as high as 1 mmol can be reached in these systems at 100 C. Alanine formation from propanethiol is also a favorable reaction. On the other hand, the calculated equilibrium log activities of cysteine and serine from propanethiol are -21 and -19, respectively, at 100 C. These results

  17. Ocular Effects of Sulfur Mustard

    Directory of Open Access Journals (Sweden)

    Yunes Panahi

    2013-06-01

    Full Text Available Purpose: To review current knowledge about ocular effects of sulfur mustard (SM and the associated histopathologic findings and clinical manifestationsMethods: Literature review of medical articles (human and animal studies was accomplished using PubMed, Scopus and ISI databases. A total of 274 relevant articles in English were retrieved and reviewed thoroughly.Results: Eyes are the most sensitive organs to local toxic effects of mustard gas. Ocular injuries are mediated through different toxic mechanisms including: biochemical damages, biomolecular and gene expression modification, induction of immunologic and inflammatory reactions, disturbing ultrastructural architecture of the cornea, and long-lasting corneal denervation. The resulting ocular injuries can roughly be categorized into acute or chronic complications. Most of the patients recover from acute injuries, but a minority of victims will suffer from chronic ocular complications. Mustard gas keratopathy (MGK is a devastating late complication of SM intoxication that proceeds from limbal stem cell deficiency (LSCD.Conclusion: SM induces several different damaging changes in case of ocular exposure; hence leading to a broad spectrum of ocular manifestations in terms of severity, timing and form. Unfortunately, no effective strategy has been introduced yet to inhibit or restore these damaging changes.

  18. Polymer Electrolytes for Lithium/Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    The Nam Long Doan

    2012-08-01

    Full Text Available This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes.

  19. Mixed Population Screening for Sulfur Isotopes

    Institute of Scientific and Technical Information of China (English)

    CUI Bin; ZHAO Lei; ZHAN Zhaoyang; HE Zhijun

    2004-01-01

    Quantitative research of the origin of sulfur isotopes is a difficult problem that has puzzled geochemists all along. In the study of the middle and lower reaches of the Yangtze River and the Dongpo orefield in Hunan Province,the authors successfully applied the mathematical model of mixed population screening to quantitatively resolving the problem on the origin of sulfur isotopes, which is significant in finding out the source of mineralizing matter and metallogenic mechanisms.

  20. Biologically produced sulfur particles and polysulfide ions

    OpenAIRE

    Kleinjan, W.E.

    2005-01-01

    This thesis deals with the effects of particles of biologically produced sulfur (or 'biosulfur') on a biotechnological process for the removal of hydrogen sulfide from gas streams. Particular emphasis is given to the role of polysulfide ions in such a process. These polysulfide ions are formed from reaction of sulfide with biologically produced sulfur. The basic concepts of this H 2 S removal process were developed at the department of Environmental Technology of Wageningen University and the...

  1. The sulfur metabolism of Cytophaga johnsonae

    International Nuclear Information System (INIS)

    Because the cellular sulfur of most bacteria is essentially reduced sulfur form, the energetically expensive process of assimilatory sulfate reduction is prevented by various regulatory mechanisms when reduced sulfur is available. However, members of the Cytophaga-Flexibacter group of gliding bacteria contain 20% or more of their sulfur in the form of the sulfonate moiety of sulfonolipids, which is derived from cysteate; thus a large portion of their cellular sulfur is only one step more reduced than sulfate. Regulation of sulfate assimilation by Cytophaga johnsonae differs from that in other bacteria studied in that, when reduced sulfur sources such as a low concentration of cystine or a peptide-containing medium are available, the initial steps of sulfate assimilation that lead to cysteate, and thus sulfonolipid synthesis are operative, whereas the terminal steps of sulfate assimilation leading to cysteine and methionine (reduced sulfur) synthesis are repressed. The biosynthetic pathway leading to cysteate has not yet been elucidated. Cysteate sulfur can be derived from either sulfate or cystine, but the origin of the carbon is an enigma. It appears that cysteate carbon arises from a glycolytic intermediate. In a series of experiments with cell-free extracts, no evidence was obtained for the participation of phosphoenolpyruvate as a precursor to cysteate. Two lines of evidence support the hypothesis that phosphoserine is the ultimate precursor to cysteate: (a) this pathway does not require the existence of sulfonate intermediates (none have ever been detected), and (b) addition of phosphoserine to a cell extract incubated with [35S]cysteine stimulated the incorporation of 35S into cysteate

  2. The sulfur metabolism of Cytophaga johnsonae

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, D.F.

    1989-01-01

    Because the cellular sulfur of most bacteria is essentially reduced sulfur form, the energetically expensive process of assimilatory sulfate reduction is prevented by various regulatory mechanisms when reduced sulfur is available. However, members of the Cytophaga-Flexibacter group of gliding bacteria contain 20% or more of their sulfur in the form of the sulfonate moiety of sulfonolipids, which is derived from cysteate; thus a large portion of their cellular sulfur is only one step more reduced than sulfate. Regulation of sulfate assimilation by Cytophaga johnsonae differs from that in other bacteria studied in that, when reduced sulfur sources such as a low concentration of cystine or a peptide-containing medium are available, the initial steps of sulfate assimilation that lead to cysteate, and thus sulfonolipid synthesis are operative, whereas the terminal steps of sulfate assimilation leading to cysteine and methionine (reduced sulfur) synthesis are repressed. The biosynthetic pathway leading to cysteate has not yet been elucidated. Cysteate sulfur can be derived from either sulfate or cystine, but the origin of the carbon is an enigma. It appears that cysteate carbon arises from a glycolytic intermediate. In a series of experiments with cell-free extracts, no evidence was obtained for the participation of phosphoenolpyruvate as a precursor to cysteate. Two lines of evidence support the hypothesis that phosphoserine is the ultimate precursor to cysteate: (a) this pathway does not require the existence of sulfonate intermediates (none have ever been detected), and (b) addition of phosphoserine to a cell extract incubated with ({sup 35}S)cysteine stimulated the incorporation of {sup 35}S into cysteate.

  3. An Aerosol Condensation Model for Sulfur Trioxide

    Energy Technology Data Exchange (ETDEWEB)

    Grant, K E

    2008-02-07

    This document describes a model for condensation of sulfuric acid aerosol given an initial concentration and/or source of gaseous sulfur trioxide (e.g. fuming from oleum). The model includes the thermochemical effects on aerosol condensation and air parcel buoyancy. Condensation is assumed to occur heterogeneously onto a preexisting background aerosol distribution. The model development is both a revisiting of research initially presented at the Fall 2001 American Geophysical Union Meeting [1] and a further extension to provide new capabilities for current atmospheric dispersion modeling efforts [2]. Sulfuric acid is one of the most widely used of all industrial chemicals. In 1992, world consumption of sulfuric acid was 145 million metric tons, with 42.4 Mt (mega-tons) consumed in the United States [10]. In 2001, of 37.5 Mt consumed in the U.S., 74% went into producing phosphate fertilizers [11]. Another significant use is in mining industries. Lawuyi and Fingas [7] estimate that, in 1996, 68% of use was for fertilizers and 5.8% was for mining. They note that H{sub 2}SO{sub 4} use has been and should continue to be very stable. In the United States, the elimination of MTBE (methyl tertiary-butyl ether) and the use of ethanol for gasoline production are further increasing the demand for petroleum alkylate. Alkylate producers have a choice of either a hydrofluoric acid or sulfuric acid process. Both processes are widely used today. Concerns, however, over the safety or potential regulation of hydrofluoric acid are likely to result in most of the growth being for the sulfuric acid process, further increasing demand [11]. The implication of sulfuric acid being a pervasive industrial chemical is that transport is also pervasive. Often, this is in the form of oleum tankers, having around 30% free sulfur trioxide. Although sulfuric acid itself is not a volatile substance, fuming sulfuric acid (referred to as oleum) is [7], the volatile product being sulfur trioxide

  4. The significance of glucosinolates for sulfur storage in Brassicaceae seedlings

    OpenAIRE

    Aghajanzadeh, Tahereh; Hawkesford, Malcolm J.; de Kok, Luit J.

    2014-01-01

    Brassica juncea seedlings contained a twofold higher glucosinolate content than B. rapa and these secondary sulfur compounds accounted for up to 30% of the organic sulfur fraction. The glucosinolate content was not affected by H2S and SO2 exposure, demonstrating that these sulfur compounds did not form a sink for excessive atmospheric supplied sulfur. Upon sulfate deprivation, the foliarly absorbed H2S and SO2 replaced sulfate as the sulfur source for growth of B. juncea and B. rapa seedlings...

  5. Graphene-Wrapped Sulfur Particles as a Rechargeable Lithium-Sulfur-Battery Cathode Material with High Capacity and Cycling Stability

    OpenAIRE

    Wang, Hailiang; Yang, Yuan; Liang, Yongye; Robinson, Joshua Tucker; Li, Yanguang; Jackson, Ariel; Cui, Yi; Dai, Hongjie

    2011-01-01

    We report the synthesis of a graphene-sulfur composite material by wrapping polyethyleneglycol (PEG) coated submicron sulfur particles with mildly oxidized graphene oxide sheets decorated by carbon black nanoparticles. The PEG and graphene coating layers are important to accommodating volume expansion of the coated sulfur particles during discharge, trapping soluble polysulfide intermediates and rendering the sulfur particles electrically conducting. The resulting graphene-sulfur composite sh...

  6. Sulfur metabolizing microbes dominate microbial communities in Andesite-hosted shallow-sea hydrothermal systems.

    Science.gov (United States)

    Zhang, Yao; Zhao, Zihao; Chen, Chen-Tung Arthur; Tang, Kai; Su, Jianqiang; Jiao, Nianzhi

    2012-01-01

    To determine microbial community composition, community spatial structure and possible key microbial processes in the shallow-sea hydrothermal vent systems off NE Taiwan's coast, we examined the bacterial and archaeal communities of four samples collected from the water column extending over a redoxocline gradient of a yellow and four from a white hydrothermal vent. Ribosomal tag pyrosequencing based on DNA and RNA showed statistically significant differences between the bacterial and archaeal communities of the different hydrothermal plumes. The bacterial and archaeal communities from the white hydrothermal plume were dominated by sulfur-reducing Nautilia and Thermococcus, whereas the yellow hydrothermal plume and the surface water were dominated by sulfide-oxidizing Thiomicrospira and Euryarchaeota Marine Group II, respectively. Canonical correspondence analyses indicate that methane (CH(4)) concentration was the only statistically significant variable that explains all community cluster patterns. However, the results of pyrosequencing showed an essential absence of methanogens and methanotrophs at the two vent fields, suggesting that CH(4) was less tied to microbial processes in this shallow-sea hydrothermal system. We speculated that mixing between hydrothermal fluids and the sea or meteoric water leads to distinctly different CH(4) concentrations and redox niches between the yellow and white vents, consequently influencing the distribution patterns of the free-living Bacteria and Archaea. We concluded that sulfur-reducing and sulfide-oxidizing chemolithoautotrophs accounted for most of the primary biomass synthesis and that microbial sulfur metabolism fueled microbial energy flow and element cycling in the shallow hydrothermal systems off the coast of NE Taiwan. PMID:22970260

  7. Sulfur metabolizing microbes dominate microbial communities in Andesite-hosted shallow-sea hydrothermal systems.

    Directory of Open Access Journals (Sweden)

    Yao Zhang

    Full Text Available To determine microbial community composition, community spatial structure and possible key microbial processes in the shallow-sea hydrothermal vent systems off NE Taiwan's coast, we examined the bacterial and archaeal communities of four samples collected from the water column extending over a redoxocline gradient of a yellow and four from a white hydrothermal vent. Ribosomal tag pyrosequencing based on DNA and RNA showed statistically significant differences between the bacterial and archaeal communities of the different hydrothermal plumes. The bacterial and archaeal communities from the white hydrothermal plume were dominated by sulfur-reducing Nautilia and Thermococcus, whereas the yellow hydrothermal plume and the surface water were dominated by sulfide-oxidizing Thiomicrospira and Euryarchaeota Marine Group II, respectively. Canonical correspondence analyses indicate that methane (CH(4 concentration was the only statistically significant variable that explains all community cluster patterns. However, the results of pyrosequencing showed an essential absence of methanogens and methanotrophs at the two vent fields, suggesting that CH(4 was less tied to microbial processes in this shallow-sea hydrothermal system. We speculated that mixing between hydrothermal fluids and the sea or meteoric water leads to distinctly different CH(4 concentrations and redox niches between the yellow and white vents, consequently influencing the distribution patterns of the free-living Bacteria and Archaea. We concluded that sulfur-reducing and sulfide-oxidizing chemolithoautotrophs accounted for most of the primary biomass synthesis and that microbial sulfur metabolism fueled microbial energy flow and element cycling in the shallow hydrothermal systems off the coast of NE Taiwan.

  8. Bacterial meningitis in children

    International Nuclear Information System (INIS)

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

  9. Interaction of insulin with methyl tert-butyl ether promotes molten globule-like state and production of reactive oxygen species.

    Science.gov (United States)

    Valipour, Masoumeh; Maghami, Parvaneh; Habibi-Rezaei, Mehran; Sadeghpour, Mostafa; Khademian, Mohamad Ali; Mosavi, Khadijeh; Sheibani, Nader; Moosavi-Movahedi, Ali Akbar

    2015-09-01

    Interaction of methyl tert-butyl ether (MTBE) with proteins is a new look at its potential adverse biological effects. When MTBE is released to the environment it enters the blood stream through inhalation, and could affect the properties of various proteins. Here we investigated the interaction of MTBE with insulin and its effect on insulin structural changes. Our results showed that insulin formed a molten globule (MG)-like structure in the presence of 8 μM MTBE under physiological pH. The insulin structural changes were studied using spectroscopy methods, viscosity calculation, dynamic light scattering and differential scanning calorimetry. To delineate the mechanisms involved in MTBE-protein interactions, the formation of reactive oxygen specious (ROS) and formation of protein aggregates were measured. The chemiluminscence experiments revealed an increase in ROS production in the presence of MTBE especially in the MG-like state. These results were further confirmed by the aggregation tests, which indicated more aggregation of insulin at 40 μM MTBE compared with 8 μM. Thus, the formation of initial aggregates and exposure of the hydrophobic patches upon formation of the MG-like state in the presence of MTBE drives protein oxidation and ROS generation. PMID:26193678

  10. Quantitative proteomic analysis of milk fat globule membrane (MFGM) proteins in human and bovine colostrum and mature milk samples through iTRAQ labeling.

    Science.gov (United States)

    Yang, Mei; Cong, Min; Peng, Xiuming; Wu, Junrui; Wu, Rina; Liu, Biao; Ye, Wenhui; Yue, Xiqing

    2016-05-18

    Milk fat globule membrane (MFGM) proteins have many functions. To explore the different proteomics of human and bovine MFGM, MFGM proteins were separated from human and bovine colostrum and mature milk, and analyzed by the iTRAQ proteomic approach. A total of 411 proteins were recognized and quantified. Among these, 232 kinds of differentially expressed proteins were identified. These differentially expressed proteins were analyzed based on multivariate analysis, gene ontology (GO) annotation and KEGG pathway. Biological processes involved were response to stimulus, localization, establishment of localization, and the immune system process. Cellular components engaged were the extracellular space, extracellular region parts, cell fractions, and vesicles. Molecular functions touched upon were protein binding, nucleotide binding, and enzyme inhibitor activity. The KEGG pathway analysis showed several pathways, including regulation of the actin cytoskeleton, focal adhesion, neurotrophin signaling pathway, leukocyte transendothelial migration, tight junction, complement and coagulation cascades, vascular endothelial growth factor signaling pathway, and adherens junction. These results enhance our understanding of different proteomes of human and bovine MFGM across different lactation phases, which could provide important information and potential directions for the infant milk powder and functional food industries. PMID:27159491

  11. Sulfur Isotope Exchange between S-35 Labeled Inorganic Sulfur-Compounds in Anoxic Marine-Sediments

    DEFF Research Database (Denmark)

    FOSSING, H.; THODEANDERSEN, S.; JØRGENSEN, BB

    1992-01-01

    of isotope exchange, specific radioactivities of the reduced sulfur pools were poorly defined and could not be used to calculate their rates of formation. Such isotope exchange reactions between the reduced inorganic sulfur compounds will affect the stable isotope distribution and are expected to decrease...

  12. Infiltrating sulfur into a highly porous carbon sphere as cathode material for lithium–sulfur batteries

    International Nuclear Information System (INIS)

    Highlights: • A highly porous carbon (HPC) with regular spherical morphology was synthesized. • Sulfur/HPC composites were prepared by melt–diffusion method. • Sulfur/HPC composites showed improved cyclablity and long-term cycle life. - Abstract: Sulfur composite material with a highly porous carbon sphere as the conducting container was prepared. The highly porous carbon sphere was easily synthesized with resorcinol–formaldehyde precursor as the carbon source. The morphology of the carbon was observed with field emission scanning electron microscope and transmission electron microscope, which showed a well-defined spherical shape. Brunauer–Emmett–Teller analysis indicated that it possesses a high specific surface area of 1563 m2 g−1 and a total pore volume of 2.66 cm3 g−1 with a bimodal pore size distribution, which allow high sulfur loading and easy transportation of lithium ions. Sulfur carbon composites with varied sulfur contents were prepared by melt–diffusion method and lithium sulfur cells with the sulfur composites showed improved cyclablity and long-term cycle life

  13. Reaction of oxalic and sulfuric acids with vanadium in spent sulfuric-acid vanadium catalysts

    International Nuclear Information System (INIS)

    The effect of oxalic acid on the degree of extraction of vanadium from spent sulfuric acid catalysts is studied. It is shown that soluble vanadium oxalate complexes are formed in the presence of sulfuric acid both in aqueous solution and in a mixture of solid components

  14. Metal-Sulfur Battery Cathodes Based on PAN-Sulfur Composites.

    Science.gov (United States)

    Wei, Shuya; Ma, Lin; Hendrickson, Kenville E; Tu, Zhengyuan; Archer, Lynden A

    2015-09-23

    Sulfur/polyacrylonitrile composites provide a promising route toward cathode materials that overcome multiple, stubborn technical barriers to high-energy, rechargeable lithium-sulfur (Li-S) cells. Using a facile thermal synthesis procedure in which sulfur and polyacrylonitrile (PAN) are the only reactants, we create a family of sulfur/PAN (SPAN) nanocomposites in which sulfur is maintained as S3/S2 during all stages of the redox process. By entrapping these smaller molecular sulfur species in the cathode through covalent bonding to and physical confinement in a conductive host, these materials are shown to completely eliminate polysulfide dissolution and shuttling between lithium anode and sulfur cathode. We also show that, in the absence of any of the usual salt additives required to stabilize the anode in traditional Li-S cells, Li-SPAN cells cycle trouble free and at high Coulombic efficiencies in simple carbonate electrolytes. Electrochemical and spectroscopic analysis of the SPAN cathodes at various stages of charge and discharge further show a full and reversible reduction and oxidation between elemental sulfur and Li-ions in the electrolyte to produce Li2S as the only discharge product over hundreds of cycles of charge and discharge at fixed current densities. PMID:26325146

  15. 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.

  16. Metabolism of DMSP, DMS and DMSO by the cultivable bacterial community associated with the DMSP-producing dinoflagellate Scrippsiella trochoidea

    Digital Repository Service at National Institute of Oceanography (India)

    Hatton, A.D.; Shenoy, D.M.; Hart, M.C.; Mogg, A.; Green, D.H.

    Howard EC, Henriksen JR, Buchan A, Reisch CR, Burgmann H, Welsh R, Ye W, Gonzalez JM, Mace K, Joye SB, Kiene RP, Whitman WB, Moran MA (2006) Bacterial taxa that limit sulfur flux from the ocean. Science 314(5799): 649–652 Howard EC, Sun S, Biers EJ...

  17. 40 CFR Appendix T to Part 50 - Interpretation of the Primary National Ambient Air Quality Standards for Oxides of Sulfur (Sulfur...

    Science.gov (United States)

    2010-07-01

    ... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) T Appendix T to Part 50 Protection of... Ambient Air Quality Standards for Oxides of Sulfur (Sulfur Dioxide) 1. General (a) This appendix explains... ambient air quality standards for Oxides of Sulfur as measured by Sulfur Dioxide (“SO2 NAAQS”)...

  18. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  19. Electrostatic self-assembly of graphene oxide wrapped sulfur particles for lithium–sulfur batteries

    International Nuclear Information System (INIS)

    Highlights: • Researched graphene oxide wrapped sulfur particles for lithium–sulfur batteries. • New approach for core–shell GO/S composites by electrostatic self-assembly method. • Both core–shell structure and the GO support help to retard the diffusion of polysulfides during the electrochemical cycling process of GO/S cathode. - Abstract: A novel graphene oxide (GO)/sulfur (S) composite is developed by electrostatic self-assembly method. Remarkably, the core–shell structure of the composite and the GO support helps to retard the diffusion of polysulfides during the electrochemical cycling process. The GO/sulfur cathode presents enhanced cycling ability. Specific discharge capacities up to 494.7 mAh g−1 over 200 cycles at 0.1 C is achieved with enhanced columbic efficiency around 95%, representing a good cathode material for lithium–sulfur batteries

  20. Genomic Insights into the Sulfur Metabolism of Phototrophic Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Bryant, Donald A.

    2008-01-01

    Green sulfur bacteria (GSB) utilize various combinations of sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen for anaerobic photoautotrophic growth. Genome sequence data is currently available for 12 strains of GSB. We present here a genome-based survey of the distribution and...... phylogenies of genes involved in oxidation of sulfur compounds in these strains. Sulfide:quinone reductase, encoded by sqr, is the only known sulfur-oxidizing enzyme found in all strains. All sulfide-utilizing strains contain the dissimilatory sulfite reductase dsrABCEFHLNMKJOPT genes, which appear to be...... involved in elemental sulfur utilization. All thiosulfate-utilizing strains have an identical sox gene cluster (soxJXYZAKBW). The soxCD genes found in certain other thiosulfate-utilizing organisms like Paracoccus pantotrophus are absent from GSB. Genes encoding flavocytochrome c (fccAB), adenosine-5...

  1. Genomic and Evolutionary Perspectives on Sulfur Metabolism in Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Bryant, Donald A.

    2008-01-01

    Green sulfur bacteria (GSB) are anaerobic photoautotrophs that oxidize sulfide, elemental sulfur, thiosulfate, ferrous iron, and hydrogen for growth. We present here an analysis of the distribution and evolution of enzymes involved in oxidation of sulfur compounds in GSB based on genome sequence...... data from 12 strains. Sulfide:quinone reductase (SQR) is found in all strains. Chlorobium ferrooxidans, which cannot grow on sulfide but grows on Fe2+, has apparently lost all genes involved in oxidation of sulfur compounds other than sqr. Instead, this organism possesses genes involved in assimilatory...... sulfate reduction, a trait that is unusual in GSB. The dissimilatory sulfite reductase (Dsr) enzyme system, which appears to be involved in elemental sulfur utilization, is found in all sulfide-utilizing strains except Chloroherpeton thalassium. The absence of Dsr enzymes in this early diverging GSB, in...

  2. Effect of sulfur content in a sulfur-activated carbon composite on the electrochemical properties of a lithium/sulfur battery

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Woo; Kim, Changhyeon; Ryu, Ho-Suk; Cho, Gyu-Bong; Cho, Kwon-Koo; Kim, Ki-Won [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Ahn, Jou-Hyeon [Department of Chemical & Biological Engineering, Gyeongsang National University, Jinju (Korea, Republic of); Wang, Guoxiu [School of Chemistry and Forensic Science, University of Technology Sydney, Sydney, NSW 2007 (Australia); Ahn, Jae-Pyeung [Advanced Analysis Center, Research Planning & Coordination Division, KIST, Seoul (Korea, Republic of); Ahn, Hyo-Jun, E-mail: ahj@gnu.ac.kr [School of Materials Science and Engineering, Gyeongsang National University, Jinju (Korea, Republic of)

    2015-09-15

    Highlights: • The content of sulfur in activated carbon was controlled by solution process. • The sulfur electrode with low sulfur content shows the best performance. • The Li/S battery has capacity of 1360 mAh/g at 1 C and 702 mAh/g at 10 C. - Abstract: The content of sulfur in sulfur/activated carbon composite is controlled from 32.37 wt.% to 55.33 wt.% by a one-step solution-based process. When the sulfur content is limited to 41.21 wt.%, it can be loaded into the pores of an activated carbon matrix in a highly dispersed state. On the contrary, when the sulfur content is 55.33 wt.%, crystalline sulfur can be detected on the surface of the activated carbon matrix. The best electrochemical performance can be obtained for a sulfur electrode with the lowest sulfur content. The sulfur/activated carbon composite with 32.37 wt.% sulfur afforded the highest first discharge capacity of 1360 mAh g{sup −1} at 1 C rate and a large reversible capacity of 702 mAh g{sup −1} at 10 C (16.75 A/g)

  3. The effective synthesis of Insoluble sulfur using electron beam

    International Nuclear Information System (INIS)

    Vulcanization is process that formed crosslinking by Insoluble sulfur between linear structure of rubber polymer. Recently, Synthesis of Insoluble sulfur is used Thermal polymerization using about 250 ∼ 300 .deg. C and extraction process is used carbon disulfide(CS2) for separation between soluble sulfur and insoluble sulfur. But this process isn't environmental, economical and safety. This research was focus on developing of insoluble sulfur synthesis process using electron beam. This new process is using under the 140 .deg. C. Because of that, explosion risk is decrease, environmental and economical factor is increased. The sulfur can be melt by increase temperature or made solution using carbon disulfide. And electron beam is irradiated melting sulfur or sulfur solution. After irradiation, The high purity insoluble sulfur can be obtained by separation with carbon disulfide

  4. Sulfur 'Concrete' for Lunar Applications - Environmental Considerations

    Science.gov (United States)

    Grugel, R. N.

    2008-01-01

    Commercial use of sulfur concrete on Earth is well established, particularly in corrosive, e.g., acid and salt, environments. Having found troilite (FeS) on the Moon raises the question of using extracted sulfur as a lunar construction material, an attractive alternative to conventional concrete as it does not require water. For the purpose of this Technical Memorandum, it is assumed that lunar ore is mined, refined, and the raw sulfur processed with appropriate lunar regolith to form, for example, bricks. With this stipulation, it is then noted that the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. The work presented here evaluates two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar simulant as an aggregate addition. One set was subjected to extended periods in high vacuum to evaluate sublimation issues, and the other was cycled between room and liquid nitrogen temperatures to investigate their subsequent mechanical integrity. Results are presented from both investigations, discussed, and put into the context of the lunar environment.

  5. Metabolic Reactions among Organic Sulfur Compounds

    Science.gov (United States)

    Schulte, M.; Rogers, K.

    2005-01-01

    Sulfur is central to the metabolisms of many organisms that inhabit extreme environments. Numerous authors have addressed the energy available from a variety of inorganic sulfur redox pairs. Less attention has been paid, however, to the energy required or gained from metabolic reactions among organic sulfur compounds. Work in this area has focused on the oxidation of alkyl sulfide or disulfide to thiol and formaldehyde, e.g. (CH3)2S + H2O yields CH3SH + HCHO + H2, eventually resulting in the formation of CO2 and SO4(-2). It is also found that reactions among thiols and disulfides may help control redox disequilibria between the cytoplasm and the periplasm. Building on our earlier efforts for thiols, we have compiled and estimated thermodynamic properties for alkyl sulfides. We are investigating metabolic reactions among various sulfur compounds in a variety of extreme environments, ranging from sea floor hydrothermal systems to organic-rich sludge. Using thermodynamic data and the revised HKF equation of state, along with constraints imposed by the geochemical environments sulfur-metabolizing organisms inhabit, we are able to calculate the amount of energy available to these organisms.

  6. Digestion of Bangka monazite with sulfuric acid

    International Nuclear Information System (INIS)

    Technology of Bangka monazite processing with alkaline method has been mastered by PPGN BATAN with the product in the form of RE (Rare Earth) which is contain U < 2 ppm and Th 12 - 16 ppm. Hence, as comparator, the research of Bangka monazite processing with acid method using sulfuric acid has been done. The aim of this research is to obtain the optimal condition of Bangka monazite's digestion using sulfuric acid so that all elements contained in the monazite that are U, Th, RE, PO4 dissolved as much as possible. The research parameter's arc monazite particle's size, sulfuric acid consumption (weight ratio of monazite ore : sulfuric acid), digestion temperature, digestion time and consumption of wash water. The results showed that the optimal conditions of digestion are 250+ 325 mesh of monazite particle's size, 1 : 2.5 of weight ratio of monazite ore: sulfuric acid, 190°C of digestion temperature, 3 hours of digestion time and 8 times of weight monazite's feed of wash water with the recovery of digested U = 99.90 %, Th = 99.44 %, RE = 98.64 % and PO4 = 99.88 %. (author)

  7. Sulfuric acid in the Venus clouds.

    Science.gov (United States)

    Sill, G. T.

    1972-01-01

    The extremely dry nature of the Venus upper atmosphere appears to demand the presence of an efficient desiccating agent as the chief constituent of the clouds of Venus. On the basis of polarization measures it is to be expected that this substance is present as spherical droplets, 1 to 2 microns in diameter, with a refractive index n of 1.46 plus or minus 0.02 at 3500A in the observed region of the atmosphere, with T about equal to 235 K. This substance must have ultraviolet, visible, and infrared reflection properties not inconsistent with the observed spectrum of Venus. Sulfuric acid, of about 86% by weight composition, roughly fulfills the first of these properties. The visible and ultraviolet transmission features of a thin layer of elemental bromine and hydrobromic acid dissolved in sulfuric acid somewhat resemble the Venus spectrum, up to 14 microns. The chemical process postulated for forming sulfuric acid involves the oxidation of sulfur and its compounds to sulfuric acid through the agency of elemental bromine produced by the photolytic decomposition of hydrogen bromide.

  8. Bacterial extracellular lignin peroxidase

    Science.gov (United States)

    Crawford, Donald L.; Ramachandra, Muralidhara

    1993-01-01

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

  9. Bacterial Skin Infections

    Science.gov (United States)

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

  10. Bacterial microflora of nectarines

    Science.gov (United States)

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

  11. Multi-isotope biogeochemistry of sulfur in the water column and surface sediments of the Baltic Sea

    Science.gov (United States)

    Böttcher, M. E.; Kamyshny, A.; Dellwig, O.; Farquhar, J.

    2012-04-01

    -reducing bacteria at low cellular activities using simple organic substrates. Sulfur isotope partitioning in the water column is close to results found in the (post-)modern surface sediments, but increases with sediment depth. Combined delta34S and delta-cap33S results give no evidence for a substantial contribution from the bacterial disproportionation of sulfur intermediates on sulfur cycling. Acknowledgements: Research was supported by Leibniz IOW and German Science Foundation, DFG (research cruises of RV Merian)

  12. Sulfur-oxidizing bacteria in environmental technology.

    Science.gov (United States)

    Pokorna, Dana; Zabranska, Jana

    2015-11-01

    Hydrogen sulfide is widely known as the most undesirable component of biogas that caused not only serious sensoric and toxic problems, but also corrosion of concrete and steel structures. Many agricultural and industrial waste used in biogas production, may contain a large amount of substances that serve as direct precursors to the formation of sulfide sulfur-sources of hydrogen sulfide in the biogas. Biological desulfurization methods are currently promoted to abiotic methods because they are less expensive and do not produce undesirable materials which must be disposed of. The final products of oxidation of sulfides are no longer hazardous. Biological removal of sulfide from a liquid or gaseous phase is based on the activity of sulfur-oxidizing bacteria. They need an oxidizing agent such as an acceptor of electrons released during the oxidation of sulfides-atmospheric oxygen or oxidized forms of nitrogen. Different genera of sulfur-oxidizing bacteria and their technological application are discussed. PMID:25701621

  13. The Properties of Sulfur Rubber Concrete (SRC)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mix designs and specimen preparation for the dry process and wet process of sulfur rubber concrete (SRC) were investigated.The compressive strength, corrosion-resistance and toughness were studied and discussed.The results show that SRC is corrosion-resistanct.Although the compressive strength of SRC decreases with increasing rubber content, the toughness increases instead.Adding micro-filler will improve the compressive strength of SRC. There is a threshold value for the sulfur content, at which the compressive strength and the work ability of SRC reach an optimum balanc e.The bond between rubber particles and surrounding sulfur is strong due to the vulcanization process that generates cross-links through S-C bonds.

  14. Anthropogenic sulfur dioxide emissions: 1850–2005

    Directory of Open Access Journals (Sweden)

    S. J. Smith

    2011-02-01

    Full Text Available Sulfur aerosols impact human health, ecosystems, agriculture, and global and regional climate. A new annual estimate of anthropogenic global and regional sulfur dioxide emissions has been constructed spanning the period 1850–2005 using a bottom-up mass balance method, calibrated to country-level inventory data. Global emissions peaked in the early 1970s and decreased until 2000, with an increase in recent years due to increased emissions in China, international shipping, and developing countries in general. An uncertainty analysis was conducted including both random and systemic uncertainties. The overall global uncertainty in sulfur dioxide emissions is relatively small, but regional uncertainties ranged up to 30%. The largest contributors to uncertainty at present are emissions from China and international shipping. Emissions were distributed on a 0.5° grid by sector for use in coordinated climate model experiments.

  15. Anthropogenic sulfur dioxide emissions: 1850–2005

    Directory of Open Access Journals (Sweden)

    S. J. Smith

    2010-06-01

    Full Text Available Sulfur aerosols impact human health, ecosystems, agriculture, and global and regional climate. A new annual estimate of anthropogenic global and regional sulfur dioxide emissions has been constructed spanning the period 1850–2005 using a bottom-up mass balance method, calibrated to country-level inventory data. Global emissions peaked in the early 1970s and decreased until 2000, with an increase in recent years due to increased emissions in China, international shipping, and developing countries in general. An uncertainty analysis was conducted including both random and systemic uncertainties. The overall global uncertainty in sulfur dioxide emissions is relatively small, but regional uncertainties ranged up to 30%. The largest contributors to uncertainty at present are emissions from China and international shipping. Emissions were distributed on a 0.5° grid by sector for use in coordinated climate model experiments.

  16. Sulfur isotope homogeneity of lunar mare basalts

    Science.gov (United States)

    Wing, Boswell A.; Farquhar, James

    2015-12-01

    We present a new set of high precision measurements of relative 33S/32S, 34S/32S, and 36S/32S values in lunar mare basalts. The measurements are referenced to the Vienna-Canyon Diablo Troilite (V-CDT) scale, on which the international reference material, IAEA-S-1, is characterized by δ33S = -0.061‰, δ34S ≡ -0.3‰ and δ36S = -1.27‰. The present dataset confirms that lunar mare basalts are characterized by a remarkable degree of sulfur isotopic homogeneity, with most new and published SF6-based sulfur isotope measurements consistent with a single mass-dependent mean isotopic composition of δ34S = 0.58 ± 0.05‰, Δ33S = 0.008 ± 0.006‰, and Δ36S = 0.2 ± 0.2‰, relative to V-CDT, where the uncertainties are quoted as 99% confidence intervals on the mean. This homogeneity allows identification of a single sample (12022, 281) with an apparent 33S enrichment, possibly reflecting cosmic-ray-induced spallation reactions. It also reveals that some mare basalts have slightly lower δ34S values than the population mean, which is consistent with sulfur loss from a reduced basaltic melt prior to eruption at the lunar surface. Both the sulfur isotope homogeneity of the lunar mare basalts and the predicted sensitivity of sulfur isotopes to vaporization-driven fractionation suggest that less than ≈1-10% of lunar sulfur was lost after a potential moon-forming impact event.

  17. Production of Lunar Concrete Using Molten Sulfur

    Science.gov (United States)

    Omar, Husam A.

    1993-01-01

    The United States has made a commitment to go back to the moon to stay in the early part of the next century. In order to achieve this objective it became evident to NASA that a Lunar Outpost will be needed to house scientists and astronauts who will be living on the moon for extended periods of time. A study has been undertaken by the authors and supported by NASA to study the feasibility of using lunar regolith with different binders such as molten sulfur, epoxy or hydraulic cement as a construction material for different lunar structures. The basic premise of this study is that it will be more logical and cost effective to manufacture lunar construction materials utilizing indigenous resources rather than transporting needed materials from earth. Lunar concrete (made from Hydraulic Cement and lunar soil) has been studied and suggested as the construction material of choice for some of the lunar projects. Unfortunately, its hydration requires water which is going to be a precious commodity on the moon. Therefore this study explores the feasibility of using binders other than hydraulic cement such as sulfur or epoxy with lunar regolith as a construction material. This report describes findings of this study which deals specifically with using molten sulfur as a binder for Lunar concrete. It describes laboratory experiments in which the sulfur to lunar soil simulant ratios by weight were varied to study the minimum amount of sulfur required to produce a particular strength. The compressive and tensile strengths of these mixes were evaluated. Metal and fiber glass fibers were added to some of the mixes to study their effects on the compressive and tensile strengths. This report also describes experiments where the sulfur is melted and mixed with the lunar regolith in a specially designed vacuum chamber. The properties of the produced concrete were compared to those of concrete produced under normal pressure.

  18. Nickel fibers/sulfur composites cathode with enhanced electrochemical performance for rechargeable lithium-sulfur batteries

    International Nuclear Information System (INIS)

    Highlights: • A novel Nickel fibers was developed as additive for sulfur cathode. • Composite cathode containing 3% nickel fibers has remarkable cycling stability and great rate capability. • Electrochemical analysis shows nickel fibers can absorb polysulfides, improve electronic conductivity, and facilitate the redox reactions in sulfur cathode. - Abstract: The commercialization of lithium sulfur batteries have so far hindered by the low electrochemical utilization and rapid capacity fading of sulfur cathode, which is induced by low electron conductivity and high dissolution of intermediate polysulfides. Recent studies have shown that the metal (Pt, Au, Ni) as electrocatalyst of lithium polysulfides and its metallic porous nanostructure can suppress the shuttle effect. In this work, we use the porous nanostructure of nickel fibers/sulfur as-designed composite cathode material for lithium sulfur batteries. The initial discharge capacity of the cathode with the added 3(%) nickel fibers was 805 mAh g−1, and the remaining capacity was 440 mAh g−1 after 50 cycles at 0.766 mA cm−2. Even at a high current density of 1.532 mA cm−2, it also kept a high discharge capacity of 310 mAh g−1. Compared with pure sulfur electrodes, the electrodes containing nickel fibers showed an obviously improved cycle and rate performances, confirming that metallic porous nanostructure of nickel can not only contribute to reducing the dissolution of polysulfides into electrolytes, but also has a catalytic effect on the redox reactions during charge-discharge process

  19. Confine sulfur in mesoporous metal–organic framework @ reduced graphene oxide for lithium sulfur battery

    International Nuclear Information System (INIS)

    Highlights: • Metal organic framework @ reduced graphene oxide was applied for sulfur cathode. • MIL-101(Cr)@rGO/S composites are synthesized by a facile two-step liquid method. • Cycling stability of MIL-101(Cr)@rGO/S sulfur cathode was improved. -- Abstract: Mesoporous metal organic framework @ reduced graphene oxide (MIL-101(Cr)@rGO) materials have been used as a host material to prepare the multi-composite sulfur cathode through a facile and effective two-step liquid phase method successfully, which is different from the simple MIL-101(Cr)/S mixed preparation method. The successful reduced graphene oxide coating in the MIL-101(Cr)@rGO improve the electronic conductivity of meso-MOFs effectively. The discharge capacity and capacity retention rate of MIL-101(Cr)@rGO/S composite sulfur cathode are as high as 650 mAh g−1 and 66.6% at the 50th cycle at the current density of 335 mA g−1. While the discharge capacity and capacity retention rate of MIL-101(Cr)/S mixed sulfur cathode is 458 mAh g−1 and 37.3%. Test results indicate that the MIL-101(Cr)@rGO is a promising host material for the sulfur cathode in the lithium–sulfur battery applications

  20. 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...

  1. Sulfur Isotope Analysis of Minerals and Fluids in a Natural CO2 Reservoir, Green River, Utah

    Science.gov (United States)

    Chen, F.; Kampman, N.; Bickle, M. J.; Busch, A.; Turchyn, A. V.

    2013-12-01

    Predicting the security of geological CO2 storage sites requires an understanding of the geochemical behavior of the stored CO2, especially of fluid-rock reactions in reservoirs, caprocks and fault zones. Factors that may influence geochemical behavior include co-injection of sulfur gases along with the CO2, either in acid-gas disposal or as contaminants in CO2 storage sites, and microbial activity, such as bacterial sulfate reduction. The latter may play an important role in buffering the redox chemistry of subsurface fluids, which could affect toxic trace metal mobilization and transport in acidic CO2-rich fluids. These processes involving sulfur are poorly understood. Natural CO2-reservoirs provide natural laboratories, where the flow and reactions of the CO2-charged fluids and the activity of microbial communities are integrated over sufficient time-scales to aid prediction of long-term CO2 storage. This study reports on sulfur isotope analyses of sulfate and sulfide minerals in rock core and in CO2-charged fluids collected from a stacked sequence of natural CO2 reservoirs at Green River, Utah. Scientific drilling adjacent to a CO2-degassing normal fault to a depth of 325m retrieved core and fluid samples from two CO2 reservoirs in the Entrada and Navajo Sandstones and from the intervening Carmel Formation caprock. Fluid samples were collected from CO2-charged springs that discharge through the faults. Sulfur exists as sulfate in the fluids, as sedimentary gypsum beds in the Carmel Formation, as remobilized gypsum veins within a fault damage zone in the Carmel Fm. and in the Entrada Sandstone, and as disseminated pyrite and pyrite-mineralized open fractures throughout the cored interval. We use the stable sulfur (δ34S) and oxygen (δ18OSO4) isotopes of the sulfate, gypsum, and pyrite to understand the source of sulfur in the reservoir as well as the timing of gypsum vein and pyrite formation. The hydration water of the gypsum is also reported to explore the

  2. Microbiological disproportionation of inorganic sulfur compounds

    DEFF Research Database (Denmark)

    Finster, Kai

    2008-01-01

    The disproportionation of inorganic sulfur intermediates at moderate temperatures (0-80 °C) is a microbiologically catalyzed chemolithotrophic process in which compounds like elemental sulfur, thiosulfate, and sulfite serve as both electron donor and acceptor, and generate hydrogen sulfide...... and sulfate. Thus the overall process is comparable to the fermentation of organic compounds such as glucose and is consequently often described as 'inorganic fermentation'. The process is primarily carried out by microorganisms with phylogenetic affiliation to the so called sulfate-reducing bacteria within...

  3. Sulfur coated colemanite as shielding material

    International Nuclear Information System (INIS)

    Sulfur coated colemanite particles were used as coarse aggregate in concrete. It was found that the boron content of concrete could be increased to a value about four times larger than those reached in the past. As the amount of sulfur coated colemanite increases in the concrete, the density and the compressive strength decrease, but the total water content increases. The fast neutron flux slowly decreases with the increased colemanite, while the thermal flux is lowered in great extent. The total radiation dose is not considerably increased even though the colemanite content is increased twice that of the ones used in the past. (author)

  4. Biosynthesis of Iron-Sulfur Clusters

    OpenAIRE

    Yuvaniyama, Pramvadee

    1999-01-01

    It is not known whether biosynthesis of [Fe-S] clusters occurs through a spontaneous self-assembly process or an enzymatic process. However, in the Azotobacter vinelandii nitrogenase system, it has been proposed that NifS and NifU are involved in the mobilization of sulfur and iron necessary for nitrogenase-specific [Fe-S] cluster assembly. The NifS protein has been shown to have cysteine desulfurase activity and can be used to supply sulfur for the in vitro catalytic formation of [Fe-S] cl...

  5. Evolutionary transitions in bacterial symbiosis

    OpenAIRE

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

    2011-01-01

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

  6. A new study of an old sink of sulfur in hot molecular cores: the sulfur residue

    OpenAIRE

    Woods, Paul M.; Occhiogrosso, Angela; Viti, Serena; Kanuchova, Z.; Palumbo, Maria Elisabetta; Price, Stephen D.

    2015-01-01

    Sulfur appears to be depleted by an order of magnitude or more from its elemental abundance in star-forming regions. In the last few years, numerous observations and experiments have been performed in order to to understand the reasons behind this depletion without providing a satisfactory explanation of the sulfur chemistry towards high-mass star-forming cores. Several sulfur-bearing molecules have been observed in these regions, and yet none are abundant enough to make up the gas-phase defi...

  7. PENGARUH KOMPOSOSI LAPISAN PADA PERMUKAAN GLOBULA MINYAK EMULSI SEBELUM PENGERINGAN SEMPROT TERHADAP SIFAT-SIFAT MIKROKAMSUL TRIGLISERIDA KAYA ASAM LEMAK W-3 [The Effect of the Composition of Adsorbed Layer at Globule Interface of -3 Fatty Acids Enriched Triglyceride Prior to Spray Drying on its Microcapsule Properties

    Directory of Open Access Journals (Sweden)

    Moch Adnan2

    2005-04-01

    Full Text Available Emulsification is the critical factor in microencapsulation by spray drying method. Sodium caseinate is a protein with good emulsifying properties. The properties could be improved by phospholipids addition in the emulsification. Phospholipids addition which stabilized oil globule might change the composition of adsorbed layer.This research was conducted to analyze the changes in composition at oil globule interface by analyzing emulsion systems of triglyceride enriched by -3 fatty acids at 5% (w/v stabilized by sodium caseinate (10% w/v and addition of phospholipids at 0; 0,5; 1,0; 1,5; 2,0; and 2,5% (w/v. The changes in composition of adsorbed layer could be determined from the changes in phospholipids and adsorbed protein concentrations at oil globule interface. Analyses were done to measure the possibility of casein-phospholipids complex, phospholipids and protein adsorption concentration at interface, and adsorbed protein.The increase of phospholipids concentration in the emulsions stabilized by sodium caseinate changed the composition of adsorbed layer at interface. There was phospholipids increase and adsorbed protein decrease at oil globule interface. These changes were caused by casein-phospholipids complex which that decreased surface activity and displacement protein by phospholipids that was adsorbed at oil globule interface.Changes of composition of casein-phospholipids at oil globule prior to microcapsulation process caused changes in the properties of microcapsule produced. The increasing phospholipids and decreasing casein concentrations at oil globule interface decreased the quality of the microcapsule, including decreasing in microencapsulation efficiency, in oxidative stability, and decreasing in EPA+DHA content.

  8. The temperature-dependent physical state of polar lipids and their miscibility impact the topography and mechanical properties of bilayer models of the milk fat globule membrane.

    Science.gov (United States)

    Murthy, Appala Venkata Ramana; Guyomarc'h, Fanny; Lopez, Christelle

    2016-09-01

    The polar lipid assembly and biophysical properties of the biological membrane enveloping the milk fat globules (the MFGM) are yet poorly known, especially in connection with the temperature history that milk can experience after its secretion. However, bioactive mechanisms depend on biological structure, which itself highly depend on temperature. The objectives of this study were to investigate polar lipid packing in hydrated bilayers, models of the MFGM, and to follow at intermolecular level temperature-induced changes in the range 60-6°C, using the combination of differential scanning calorimetry, X-ray diffraction, atomic force microscopy (AFM) imaging and force spectroscopy. MFGM polar lipids, especially sphingomyelin, contain long chain saturated fatty acids with high phase transition temperatures. On cooling, the liquid disordered ld to solid ordered so (gel) phase transition of MFGM polar lipids started at about 40°C, leading to phase separation and formation of so phase domains protruding by about 1nm from the ld phase. Indentation measurements using AFM revealed that the resistance of the so phase domains to rupture was significantly higher than that of the ld phase and that it increased for both the domain and fluid phases with decreasing temperature. However, packing and stability of the bilayers were adversely affected by fast cooling to 6°C or by cooling-rewarming cycle. This study showed that MFGM polar lipid bilayers are dynamic systems. Heterogeneity in the structure and mechanical properties of the membrane was induced by temperature-dependent so/ld phase immiscibility of the lipid components. This could have consequences on the MFGM technological and biological functions (e.g. immunity and milk lipid digestion). PMID:27349732

  9. Genetic polymorphism in milk fat globule-EGF factor 8 (MFG-E8) is associated with systemic lupus erythematosus in human.

    Science.gov (United States)

    Hu, C Y; Wu, C S; Tsai, H F; Chang, S K; Tsai, W I; Hsu, P N

    2009-07-01

    Milk fat globule-EGF factor 8 (MFG-E8) is a molecule implicated in phagocytic clearance of apoptotic cells by bridging between macrophages and apoptotic cells. Defects in MFG-E8 cause lupus-like disease in murine models. The aim of our study is to determine whether genetic variation in MFG-E8 predisposes human to systemic lupus erythematosus (SLE). A case-control study of MFG-E8 genetic polymorphism was performed on 147 SLE patients and 146 non-lupus control subjects. Single nucleotide polymorphisms (SNPs) in the coding sequence of human MFG-E8 gene were investigated. SNPs on MFG-E8 residues 3 (3(Arg or Ser)) and 76 (76(Leu or Met)) did not show genetic linkage. Genetic polymorphism on MFG-E8 residue 76 correlated significantly to SLE. The MFG-E8-76(Met) allele predisposed subjects to SLE in a recessive mode (odds ratio: 2.1, P = 0.020), while carriage of MFG-E8-76(Leu) were negatively associated with SLE. The MFG-E8 genotypic combinations with 3(Ser) and 76(Leu) showed the most pronounced protective effect on SLE when compared to the most predisposing genotype 3(Arg/Arg)-76(Met/Met) (OR: 0.29, P = 0.007). According to our result, MFG-E8 is associated with SLE predisposition in Taiwanese. Our study implicates that the impairment of phagocytic clearance of apoptotic cells through phosphotidylserine-dependent MFG-E8 system may lead to the development of human SLE. PMID:19502262

  10. Milk fat globule membrane coating of large lipid droplets in the diet of young mice prevents body fat accumulation in adulthood.

    Science.gov (United States)

    Baars, Annemarie; Oosting, Annemarie; Engels, Eefje; Kegler, Diane; Kodde, Andrea; Schipper, Lidewij; Verkade, Henkjan J; van der Beek, Eline M

    2016-06-01

    Epidemiological studies have demonstrated protective effects of breast-feeding on childhood obesity. Differences between human milk and infant milk formula (IMF) in dietary lipid structure may contribute to this effect. In our mouse model, feeding a diet containing large lipid droplets coated with phospholipids (PL) (Nuturis®; PL of milk fat globule membrane (MFGM) fraction origin) in early life protected against excessive body fat accumulation following a diet challenge in adult life. We now set out to determine the relevance of increased droplet size and/or MFGM lipid droplet coating to the observed anti-obesogenic effects in adult life. From day 16 to 42, male mouse pups were exposed to diets with small (S) or large (L) lipid droplets (0·3 v. 2·9 µm average mode diameter, respectively), either without MFGM or with MFGM coating around the lipid droplet, resulting in four groups: S (control diet), L, Scoating and Lcoating (Nuturis® IMF diet). Mice were subsequently challenged with a Western-style diet until dissection at postnatal day 98. A non-challenged group served as reference (REF). We repeatedly determined body composition between postnatal day 42 and 98. At day 98 plasma and gene expression measurements were performed. Only the Nuturis® IMF diet (Lcoating) in early life containing MFGM-coated large lipid droplets reduced body fat mass to a level comparable with the REF group. These data support the notion that the structural aspects of lipids in human milk, for example, both lipid droplet size as well as the MFGM coating, may contribute to its reported protective effect against obesity in later life. PMID:27040581

  11. Total Sulfur Deposition (wet+dry) from the Atmosphere

    Data.gov (United States)

    U.S. Environmental Protection Agency — Sulfur Dioxide (SO2) is emitted primarily as a by-product of coal combustion from power plants. Sulfur Dioxide reacts in the atmosphere to form other chemical such...

  12. Heterogeneous Interaction of Peroxyacetyl Nitrate on Liquid Sulfuric Acid

    Science.gov (United States)

    Zhang, Renyi; Leu, Ming-Taun

    1996-01-01

    The uptake of peroxyacetyl nitrate (PAN) on liquid sulfuric acid surfaces has been investigated using a fast-flow reactor coupled to a chemical ionization mass spectrometer. PAN was observed to be reversibly adsorbed on sulfuric acid.

  13. The Low-temperature Ion Sulfurizing Technology and its Applications

    Science.gov (United States)

    Ma, G. Z.; Xu, B. S.; Wang, H. D.; Li, G. L.; Zhang, S.

    A solid lubrication film mainly consists of FeS, which has excellent tribology properties, can be formed on the sulfurized iron or steel surface. The sulfurizing technology has aroused intense attention from the day it appeared. However, the widespread industrial application of sulfurizing technology was promoted by the low-temperature ion sulfurizing (LTIS) process. This paper summarized the phylogeny and sorts of sulfurizing technology firstly; then, the process flow of LTIS technology, the forming mechanism, microstructure and tribological properties of ion sulfurized layer were introduced detailedly; and then, the technological, economic and environmental merits of LTIS technology were generalized; finally, the industrial applications of LTIS technology in various typical rolling, sliding and heavy duty parts were reviewed briefly. LTIS technology, with the advantages of high sulfurizing speed, good performance of sulfurized layer and without sideeffect, has played an important role in the tribology modification of ferrous parts, and the LTIS process will become more green, simple and efficient in the future.

  14. Interaction of sulfur-loaded 3A zeolite with ethylene

    OpenAIRE

    Munter, H.J.

    2006-01-01

    The sulfur-loaded 3A clay-bond molecular sieve exposed to ethylene at temperatures higher than 190°C loses its sulfur. Mainly hydrogen sulfide is formed. This behavior restricts its use as a cracking catalyst.

  15. Oxidation of Elemental Sulfur to Sulfite by Thiobacillus thiooxidans Cells

    OpenAIRE

    Suzuki, Isamu; Chan, C W; Takeuchi, T L

    1992-01-01

    Thiobacillus thiooxidans cells oxidized elemental sulfur to sulfite, with 1 mol of O2 consumption per mol of sulfur oxidized to sulfite, when the oxidation of sulfite was inhibited with 2-n-heptyl-4-hydroxyquinoline N-oxide.

  16. Thioploca spp: filamentous sulfur bacteria with nitrate vacuoles

    DEFF Research Database (Denmark)

    Jørgensen, BB; Gallardo, VA

    1999-01-01

    Thioploca spp. are multicellular, filamentous, colorless sulfur bacteria inhabiting freshwater and marine sediments. They have elemental sulfur inclusions similar to the phylogenetically closely related Beggiatoa, but in contrast to these they live in bundles surrounded by a common sheath. Vast...

  17. Menaquinone-7 in the reaction center complex of the green sulfur bacterium Chlorobium vibrioforme functions as the electron acceptor A1

    DEFF Research Database (Denmark)

    Kjaer, B; Frigaard, N-U; Yang, F; Zybailov, B; Miller, M; Golbeck, J H; Scheller, H V

    1998-01-01

    Photosynthetically active reaction center complexes were prepared from the green sulfur bacterium Chlorobium vibrioforme NCIMB 8327, and the content of quinones was determined by extraction and high-performance liquid chromatography. The analysis showed a stoichiometry of 1.7 molecules of.......7 mT, consistent with its identification as a quinone. This spectrum is highly similar in terms of g values and line widths to photoaccumulated A1- in photosystem I of Synechococcus sp. PCC 7002. The results indicate that menaquinone-7 in the green sulfur bacterial reaction center is analogous to...

  18. Participation of S. Typhimurium cysJIH Operon in the H2S-mediated Ciprofloxacin Resistance in Presence of Sulfate as Sulfur Source

    Directory of Open Access Journals (Sweden)

    Ricardo Álvarez

    2015-07-01

    Full Text Available H2S production has been proposed as a mechanism to explain bacterial resistance to antibiotics. In this work, we present evidence for the role of the cysJIH operon in resistance to ciprofloxacin mediated by H2S production with different sulfate as the only sulfur source. We found that the products of the cysJIH operon are involved in ciprofloxacin resistance by increasing both, the levels of H2S and reduced thiols apparently counteracting antimicrobial-induced reactive oxygen species (ROS. This protective effect was observed only when bacteria were cultured in the presence of sulfate, but not with cysteine, as the sole sulfur source.

  19. Dimethylsulfoniopropionate in corals and its interrelations with bacterial assemblages in coral surface mucus

    OpenAIRE

    Frade, P.R.; Schwaninger, V.; Glasl, B.; Sintes, E.; Hill, R. W.; Simó, R.; Herndl, G.

    2016-01-01

    Corals produce copious amounts of dimethylsulfoniopropionate (DMSP), a sulfur compound thought toplay a role in structuring coral-associated bacterial communities. We tested the hypothesis that a linkage exists betweenDMSP availability in coral tissues and the community dynamics of bacteria in coral surface mucus. We determinedDMSP concentrations in three coral species (Meandrina meandrites, Porites astreoides and Siderastrea siderea) at twosampling depths (5 and 25 m) and times of day (dawn ...

  20. [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

  1. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

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

  2. Oxidation of inorganic sulfur compounds in acidophilic prokaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Rohwerder, T.; Sand, W. [Universitaet Duisburg-Essen, Biofilm Centre, Aquatic Biotechnology, Duisburg (Germany)

    2007-07-15

    The oxidation of reduced inorganic sulfur compounds to sulfuric acid is of great importance for biohydrometallurgical technologies as well as the formation of acidic (below pH 3) and often heavy metal-contaminated environments. The use of elemental sulfur as an electron donor is the predominant energy-yielding process in acidic natural sulfur-rich biotopes but also at mining sites containing sulfidic ores. Contrary to its significant role in the global sulfur cycle and its biotechnological importance, the microbial fundamentals of acidophilic sulfur oxidation are only incompletely understood. Besides giving an overview of sulfur-oxidizing acidophiles, this review describes the so far known enzymatic reactions related to elemental sulfur oxidation in acidophilic bacteria and archaea. Although generally similar reactions are employed in both prokaryotic groups, the stoichiometry of the key enzymes is different. Bacteria oxidize elemental sulfur by a sulfur dioxygenase to sulfite whereas in archaea, a sulfur oxygenase reductase is used forming equal amounts of sulfide and sulfite. In both cases, the activation mechanism of elemental sulfur is not known but highly reactive linear sulfur forms are assumed to be the actual substrate. Inhibition as well as promotion of these biochemical steps is highly relevant in bioleaching operations. An efficient oxidation can prevent the formation of passivating sulfur layers. In other cases, a specific inhibition of sulfur biooxidation may be beneficial for reducing cooling and neutralization costs. In conclusion, the demand for a better knowledge of the biochemistry of sulfur-oxidizing acidophiles is underlined. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  3. Electrochemical Lithiation of Covalently Bonded Sulfur in Vulcanized Polyisoprene

    OpenAIRE

    Fu, Chengyin; Li, Guanghui; Zhang, Jian; Cornejo, Benjamin; Piao, Sophie S.; Krassimir N. Bozhilov; Haddon, Robert C.; Guo, Juchen

    2016-01-01

    We report the synthesis of vulcanized polyisoprene (SPIP) nanowires and an investigation of the electrochemical lithiation mechanism of the covalently bonded sulfur bridges in SPIP. Electrochemical analysis demonstrates that the sulfur chains in SPIP have distinct electrochemical signatures from those that are characteristic of bulk elemental sulfur. The cyclic voltammetry and galvanostatic cycling data show a distinct multistep charge-transfer process and solid-state lithium–sulfur reaction ...

  4. Solubility series of methanofullerenes in concentrated sulfuric acid

    Science.gov (United States)

    Biglova, Yu. N.; Kolesov, S. V.; Biglova, R. Z.; Kraikin, V. A.

    2015-12-01

    A spectroscopic study of the dissolution of C60 and its monosubstituted derivatives methanofullerenes in 98% sulfuric acid revealed that methanofullerenes dissolved in sulfuric acid much better than the starting C60. A solubility series of functionalized fullerenes was obtained, which did not change during the extraction of methanofullerenes with sulfuric acid from benzene solutions. An effective methods was developed for separating methanofullerenes, which is based on the difference between the solubilities of the starting and functionalized fullerenes in concentrated sulfuric acid.

  5. Redox control of sulfur degassing in silicic magmas

    OpenAIRE

    Scaillet, Bruno; Clémente, Béatrice; Evans, Bernard W.; Pichavant, Michel

    1998-01-01

    International audience Explosive eruptions involve mainly silicic magmas in which sulfur solubility and diffusivity are low. This inhibits sulfur exsolution during magma uprise as compared to more mafic magmas such as basalts. Silicic magmas can nevertheless liberate large quantities of sulfur as shown by the monitoring of SO2 in recent explosive silicic eruptions in arc settings, which invariably have displayed an excess of sulfur relative to that calculated from melt degassing. If this e...

  6. Biological and Abiological Sulfur Reduction at High Temperatures †

    OpenAIRE

    Belkin, Shimshon; Wirsen, Carl O.; Jannasch, Holger W.

    1985-01-01

    Reduction of elemental sulfur was studied in the presence and absencè of thermophilic sulfur-reducing bacteria, at temperatures ranging from 65 to 110°C, in anoxic artificial seawater media. Above 80°C, significant amounts of sulfide were produced abiologically at linear rates, presumably by the disproportionation of sulfur. These rates increased with increasing temperature and pH and were enhanced by yeast extract. In the same medium, the sulfur respiration of two recent thermophilic isolate...

  7. Sulfur-containing compounds in \\kur{Ferula} species

    OpenAIRE

    TICHÁ, Iveta

    2012-01-01

    The theoretical part of the Bachelor thesis is focused on Ferula genus plants, their significance, occurrence and usage. The thesis also deals with their sulfur-containing compounds and the formation pathways of the sulfur compounds occurring in the Allium genus. In the experimental part, the most important Ferula volatile sulfur compounds and their possible precursor are investigated. The precursor was suggested on the basis of the principle of similar sulfur compounds in Ferula genus plants...

  8. 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 ...

  9. 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

  10. Evaluation of physicochemical properties, and antimicrobial efficacy of monoclinic sulfur-nanocolloid

    Energy Technology Data Exchange (ETDEWEB)

    Roy Choudhury, Samrat, E-mail: samratroychoudhury@gmail.com [Indian Statistical Institute, Biological Sciences Division (India); Mandal, Amrita; Chakravorty, Dipankar [Indian Association for the Cultivation of Science (India); Gopal, Madhuban [Indian Agricultural Research Institute, Divisions of Agricultural Chemicals (India); Goswami, Arunava [Indian Statistical Institute, Biological Sciences Division (India)

    2013-04-15

    Stable nanocolloids of monoclinic sulfur ({beta}-SNPs) were prepared through 'water-in-oil microemulsion technique' at room temperature after suitable modifications of the surface. The morphology (rod shaped; {approx}50 nm in diameter) and allotropic nature (monoclinic) of the SNPs were investigated with Transmission Electron Microscopy and X-ray Diffraction technique. The surface modification, colloidal stability, and surface topology of {beta}-SNPs were evaluated with Fourier Transform Infrared Spectroscopy, zeta potential analysis, and Atomic Force Microscopy. Thermal decomposition pattern of these nanosized particles was determined by Thermo Gravimetric Analysis (TGA). {beta}-SNPs-colloids expressed excellent antimicrobial activities against a series of fungal and bacterial isolates with prominent deformities at their surface. In contrast, insignificant cytotoxicity was achieved against the human derived hepatoma (HepG2) cell line upon treatment with {beta}-SNPs. A simultaneous study was performed to determine the stock concentration of {beta}-SNP-colloids using a novel high phase liquid chromatographic method. Cumulative results of this study hence, elucidate the stabilization of nanosized monoclinic sulfur at room temperature and their potential antimicrobial efficacy over micron-sized sulfur.

  11. Evaluation of physicochemical properties, and antimicrobial efficacy of monoclinic sulfur-nanocolloid

    International Nuclear Information System (INIS)

    Stable nanocolloids of monoclinic sulfur (β-SNPs) were prepared through ‘water-in-oil microemulsion technique’ at room temperature after suitable modifications of the surface. The morphology (rod shaped; ∼50 nm in diameter) and allotropic nature (monoclinic) of the SNPs were investigated with Transmission Electron Microscopy and X-ray Diffraction technique. The surface modification, colloidal stability, and surface topology of β-SNPs were evaluated with Fourier Transform Infrared Spectroscopy, zeta potential analysis, and Atomic Force Microscopy. Thermal decomposition pattern of these nanosized particles was determined by Thermo Gravimetric Analysis (TGA). β-SNPs-colloids expressed excellent antimicrobial activities against a series of fungal and bacterial isolates with prominent deformities at their surface. In contrast, insignificant cytotoxicity was achieved against the human derived hepatoma (HepG2) cell line upon treatment with β-SNPs. A simultaneous study was performed to determine the stock concentration of β-SNP-colloids using a novel high phase liquid chromatographic method. Cumulative results of this study hence, elucidate the stabilization of nanosized monoclinic sulfur at room temperature and their potential antimicrobial efficacy over micron-sized sulfur.

  12. RETENTION OF SULFUR DIOXIDE BY NYLON FILTERS

    Science.gov (United States)

    Based on laboratory studies, recovery efficiencies of sulfur dioxide (SO2) were determined for nylon filters. The nylon filters used in these experiments were found to retain SO2. A relatively uniform amount (1.7%) was recoverable from each nylon filter, independent of relative...

  13. Isotope effects of sulfur in chemical reactions

    International Nuclear Information System (INIS)

    Sulfur is an important component of organic matter because it forms compounds with many elements. Due to high chemical activity of sulfur, it takes part in biological and geological processes in which isotope effects are occurring. It has been shown during last years research of isotope effects that we have take into account not only mass difference but also many other physical properties of nuclides e.g. even or odd number of neutrons in nuclei, shape and distribution of charge, turn of nuclear spin etc. The factor remains that new theoretical ideas have been formed on the base of data, being obtained in fractionation processes of heavy element isotope, particularly uranium. Now it is being well known that effects unconnected with vibration energy have also caused an effect on fractionation of considerably lighter elements like iron and magnesium. The important question is, if these effects would come to light during the separation of sulfur isotopes. Sulfur have three even isotopes M = (32, 34, 36) and one odd M 33). This problem is still open. (author)

  14. Sulfur Upwelling off the African Coast

    Science.gov (United States)

    2002-01-01

    Though these aquamarine clouds in the waters off the coast of northern Namibia may look like algae blooms, they are in fact clouds of sulfur produced by anaerobic bacteria on the ocean's floor. This image of the sulfur-filled water was taken on April 24, 2002, by the Sea-viewing Wide Field-of-View Sensor (SeaWiFS), flying aboard the Orbview-2 satellite. The anaerobic bacteria (bacteria that can live without oxygen) feed upon algae carcasses that exist in abundance on the ocean's floor off of Namibia. As the bacteria ingest the algae husks, they produce hydrogen sulfide, which slowly builds up in the sea-floor sediments. Eventually, the hydrogen sulfide reaches the point where the sediment can no longer contain it, and it bubbles forth. When this poisonous chemical reaches the surface, it combines with the oxygen in the upper layers of the ocean to create clouds of pure sulfur. The sulfur causes the Namibian coast to smell like rotten eggs, and the hydrogen sulfide will often kill fish and drive lobsters away. For more information, read: A Bloom By Any Other Name A high-resolution (250 meters per pixel) image earlier on the 24th taken from the Moderate-Resolution Imaging Spectroradiometer (MODIS) shows additional detail in the plumes. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE. MODIS image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  15. Anodes for Rechargeable Lithium-Sulfur Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Ruiguo; Xu, Wu; Lu, Dongping; Xiao, Jie; Zhang, Jiguang

    2015-04-10

    In this work, we will review the recent developments on the protection of Li metal anode in Li-S batteries. Various strategies used to minimize the corrosion of Li anode and reducing its impedance increase will be analyzed. Other potential anodes used in sulfur based rechargeable batteries will also be discussed.

  16. Charles H. Winston and Confederate Sulfuric Acid.

    Science.gov (United States)

    Riethmiller, Steven

    1995-01-01

    Describes the invention and use of a sulfuric acid chamber by Charles Henry Winston during the Civil War. This invention helped supply munitions for the South. Winston, who was President of the Richmond Female Institute in Virginia, constructed the chamber at his farm and was granted a patent by the Confederate Patent Office in 1863. (PVD)

  17. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of these isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separation of 32S vs. 34S were 1.127 for H2S, 1.048 for COS, 0.838 for SF4, and 1.058 for CH3SH. Relative volatilities of 32S vs. 34S are 1.0006 for COS and 0.9976 for SF4. There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H2Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produced separated isotopes with an effect similar to that found for sulfur in SF4. 8 refs., 2 tabs

  18. 21 CFR 184.1095 - Sulfuric acid.

    Science.gov (United States)

    2010-04-01

    ... Chemicals Codex,” 3d Ed. (1981), pp. 317-318, which is incorporated by reference. Copies may be obtained... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfuric acid. 184.1095 Section 184.1095 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  19. Sulfur Dioxide Emission Control, Blockade and Drainage

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper presents the present status of sulfur dioxide emission from thermal plants in China, tells the main problems existing in its emission control and finally gives out suggestions to the problems, that is, to constitute complete standards and regulations and enhancesupervision accordingly.

  20. Helium and Sulfur Hexafluoride in Musical Instruments

    Science.gov (United States)

    Forinash, Kyle; Dixon, Cory L.

    2014-01-01

    The effects of inhaled helium on the human voice were investigated in a recent article in "The Physics Teacher." As mentioned in that article, demonstrations of the effect are a popular classroom activity. If the number of YouTube videos is any indication, the effects of sulfur hexafluoride on the human voice are equally popular.…

  1. Development of enhanced sulfur rejection processes

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Richardson, P.E.

    1996-03-01

    Research at Virginia Tech led to the development of two complementary concepts for improving the removal of inorganic sulfur from many eastern U.S. coals. These concepts are referred to as Electrochemically Enhanced Sulfur Rejection (EESR) and Polymer Enhanced Sulfur Rejection (PESR) processes. The EESR process uses electrochemical techniques to suppress the formation of hydrophobic oxidation products believed to be responsible for the floatability of coal pyrite. The PESR process uses polymeric reagents that react with pyrite and convert floatable middlings, i.e., composite particles composed of pyrite with coal inclusions, into hydrophilic particles. These new pyritic-sulfur rejection processes do not require significant modifications to existing coal preparation facilities, thereby enhancing their adoptability by the coal industry. It is believed that these processes can be used simultaneously to maximize the rejection of both well-liberated pyrite and composite coal-pyrite particles. The project was initiated on October 1, 1992 and all technical work has been completed. This report is based on the research carried out under Tasks 2-7 described in the project proposal. These tasks include Characterization, Electrochemical Studies, In Situ Monitoring of Reagent Adsorption on Pyrite, Bench Scale Testing of the EESR Process, Bench Scale Testing of the PESR Process, and Modeling and Simulation.

  2. Influence of Sulfur Fertilization on the Antioxidant Activities of Onion Juices Prepared by Thermal Treatment

    OpenAIRE

    Koh, Eunmi; Surh, Jeonghee

    2016-01-01

    Two onions (Sulfur-1 and Sulfur-4) cultivated with different sulfur applications were thermally processed to elucidate the effects of heat treatment on browning index and antioxidant activity. Sulfur-4 onion had higher sulfur content compared with the Sulfur-1 onion. After thermal processing, browning intensity was different between the two onions juices, with lower values observed for Sulfur-4 onion juice. This suggests that sulfur inhibits the Maillard browning reaction. The total reducing ...

  3. Leaching of initial and burnt danburite by sulfuric acid

    International Nuclear Information System (INIS)

    Sulfuric acid decomposition of initial and burnt danburite was studied in this work. The interaction between initial and pre baked danburite by sulfuric acid was studied as well. The influence of temperature, process duration and concentration of sulfuric acid on the rate of component extraction from initial and burnt danburite was defined. The chemical composition of initial danburite is presented.

  4. 40 CFR 52.57 - Control strategy: Sulfur oxides.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Sulfur oxides. 52.57... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.57 Control strategy: Sulfur oxides... part of the revised sulfur oxide control strategy, is disapproved as it applies to the Widows...

  5. Rnf Genes in Purple Sulfur Bacterium Allochromatium vinosum

    OpenAIRE

    DİNÇTÜRK, H. Benan; DEMİR, Volkan

    2006-01-01

    Allochromatium vinosum is a photosynthetic, diazotrophic purple sulfur bacterium that oxidizes reduced sulfur compounds hydrogen sulfide, elemental sulfur and thiosulfide. In this article, we report the presence of rnf genes in Allochromatium vinosum, some of which have been reported to take part in nitrogen fixation in some species.

  6. 46 CFR 153.545 - Special requirements for liquid sulfur.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Special requirements for liquid sulfur. 153.545 Section... Equipment Special Requirements § 153.545 Special requirements for liquid sulfur. (a) A containment system carrying liquid sulfur must have: (1) A cargo tank ventilation system that: (i) Maintains the H2S...

  7. Antioxidant effects of sulfur-containing amino acids.

    Science.gov (United States)

    Atmaca, Gulizar

    2004-10-31

    Sulfur is an essential element for the entire biological kingdom because of its incorporation into amino acids, proteins and other biomolecules. Sulfur atoms are also important in the iron-containing flavoenzymes. Unlike humans, plants can use inorganic sulfur to synthesize sulfur-containing amino acids. Therefore, plants are an important source of sulfur for humans. Sulfur-containing compounds are found in all body cells and are indispensable for life. Some of sulfur-containing antioxidant compounds are, cysteine, methionine, taurine, glutathione, lipoic acid, mercaptopropionylglycine, N-acetylcysteine, and the three major organosulfur compounds of garlic oil, diallylsulfide, diallyldisulfide and diallyltrisulfide. In a comparison of the structure-function relationship among these sulfur-containing antioxidant compounds, dihydrolipoic acid (the reduced form of LA) is the most effective antioxidant. Dihydrolipoic acid contains two sulfhydryl groups and can undergo further oxidation reaction to form lipoic acid. The antioxidative activities of sulfur-containing compounds follow a general trend, the more highly reduced forms are stronger antioxidants and the number of sulfur atoms determine, at least in part, their modulatory activites on the glutathione related antioxidant enzymes. In this article, the antioxidant effects and the antioxidative activities, of sulfur-containing amino acids, are reviewed. In addition, the general antioxidant effects and the structure-function relationship of some sulfur-containing compounds are also reviewed. PMID:15515186

  8. Nitrogen, carbon, and sulfur isotopic change during heterotrophic (Pseudomonas aureofaciens) and autotrophic (Thiobacillus denitrificans) denitrification reactions.

    Science.gov (United States)

    Hosono, Takahiro; Alvarez, Kelly; Lin, In-Tian; Shimada, Jun

    2015-12-01

    In batch culture experiments, we examined the isotopic change of nitrogen in nitrate (δ(15)NNO3), carbon in dissolved inorganic carbon (δ(13)CDIC), and sulfur in sulfate (δ(34)SSO4) during heterotrophic and autotrophic denitrification of two bacterial strains (Pseudomonas aureofaciens and Thiobacillus denitrificans). Heterotrophic denitrification (HD) experiments were conducted with trisodium citrate as electron donor, and autotrophic denitrification (AD) experiments were carried out with iron disulfide (FeS2) as electron donor. For heterotrophic denitrification experiments, a complete nitrate reduction was accomplished, however bacterial denitrification with T. denitrificans is a slow process in which, after seventy days nitrate was reduced to 40% of the initial concentration by denitrification. In the HD experiment, systematic change of δ(13)CDIC (from -7.7‰ to -12.2‰) with increase of DIC was observed during denitrification (enrichment factor εN was -4.7‰), suggesting the contribution of C of trisodium citrate (δ(13)C=-12.4‰). No SO4(2-) and δ(34)SSO4 changes were observed. In the AD experiment, clear fractionation of δ(13)CDIC during DIC consumption (εC=-7.8‰) and δ(34)SSO4 during sulfur use of FeS2-S (around 2‰), were confirmed through denitrification (εN=-12.5‰). Different pattern in isotopic change between HD and AD obtained on laboratory-scale are useful to recognize the type of denitrification occurring in the field. PMID:26529303

  9. Nitrogen, carbon, and sulfur isotopic change during heterotrophic (Pseudomonas aureofaciens) and autotrophic (Thiobacillus denitrificans) denitrification reactions

    Science.gov (United States)

    Hosono, Takahiro; Alvarez, Kelly; Lin, In-Tian; Shimada, Jun

    2015-12-01

    In batch culture experiments, we examined the isotopic change of nitrogen in nitrate (δ15NNO3), carbon in dissolved inorganic carbon (δ13CDIC), and sulfur in sulfate (δ34SSO4) during heterotrophic and autotrophic denitrification of two bacterial strains (Pseudomonas aureofaciens and Thiobacillus denitrificans). Heterotrophic denitrification (HD) experiments were conducted with trisodium citrate as electron donor, and autotrophic denitrification (AD) experiments were carried out with iron disulfide (FeS2) as electron donor. For heterotrophic denitrification experiments, a complete nitrate reduction was accomplished, however bacterial denitrification with T. denitrificans is a slow process in which, after seventy days nitrate was reduced to 40% of the initial concentration by denitrification. In the HD experiment, systematic change of δ13CDIC (from - 7.7‰ to - 12.2‰) with increase of DIC was observed during denitrification (enrichment factor εN was - 4.7‰), suggesting the contribution of C of trisodium citrate (δ13C = - 12.4‰). No SO42 - and δ34SSO4 changes were observed. In the AD experiment, clear fractionation of δ13CDIC during DIC consumption (εC = - 7.8‰) and δ34SSO4 during sulfur use of FeS2-S (around 2‰), were confirmed through denitrification (εN = - 12.5‰). Different pattern in isotopic change between HD and AD obtained on laboratory-scale are useful to recognize the type of denitrification occurring in the field.

  10. Regulation of dissimilatory sulfur oxidation in the purple sulfur bacterium Allochromatium vinosum

    OpenAIRE

    Frauke eGrimm; Bettina eFranz; Christiane eDahl

    2011-01-01

    In the purple sulfur bacterium Allochromatium vinosum, thiosulfate oxidation is strictly dependent on the presence of three periplasmic Sox proteins encoded by the soxBXAK and soxYZ genes. It is also well documented that proteins encoded in the dissimilatory sulfite reductase (dsr) operon, dsrABEFHCMKLJOPNRS, are essential for the oxidation of sulfur that is stored intracellularly as an obligatory intermediate during the oxidation of thiosulfate and sulfide. Until recently, detailed knowledge...

  11. Effects of sulfur oxides on eicosanoids

    International Nuclear Information System (INIS)

    Ultrafine metal oxides and SO2 react during coal combustion or smelting operations to form primary emissions coated with an acidic SOx layer. Ongoing work in this laboratory has examined the effects of sulfur oxides on pulmonary functions of guinea pigs. We have previously reported that 20 micrograms/m3 acidic sulfur oxide as a surface layer on ultrafine ZnO particles decreases lung volumes, decreases carbon monoxide diffusing capacity, and causes lung inflammation in guinea pigs after 4 daily 3-h exposures. It also produces bronchial hypersensitivity following a single 1-h exposure. The importance of this surface layer is demonstrated by our observation that 200 micrograms/m3 of sulfuric acid droplets of equivalent size are needed to produce the same degree of hypersensitivity. This study characterized the concentration-dependent effects of in vivo exposures to sulfur oxides on arachidonic acid metabolism in the guinea pig lung, and investigated the time course and the relation between eicosanoid composition and pulmonary functions. We focused specifically on four cyclooxygenase metabolites of arachidonic acid, that is, prostaglandins (PG) E1, F2 alpha, 6-keto prostaglandin F1 alpha, and thromboxane (Tx) B2, and two groups of sulfidopeptide leukotrienes (C4, D4, E4, and F4). Guinea pigs were exposed to ultrafine ZnO aerosol (count median diameter = 0.05 microns, sigma g = 1.80) with a layer of acidic sulfur oxide on the surface of the particles. Lung lavage was collected after exposures, and the levels of arachidonic acid metabolites were determined using radioimmunoassay (RIA). Concentration-dependent promotion of PGF2 alpha and concentration-dependent suppression of LtB4 were observed. The increased PGF2 alpha was associated with depressed vital capacity and diffusing capacity of the lungs measured in guinea pigs exposed to the same atmosphere described in a previous study

  12. Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kang [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Wang, Shengping, E-mail: spwang@cug.edu.cn [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Zhang, Hanyu; Wu, Jinping [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China)

    2013-06-01

    Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al{sub 2}O{sub 3} can provide surface area for the deposition of Li{sub 2}S and Li{sub 2}S{sub 2}. ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g{sup −1}, and the remaining capacity was 585 mAh g{sup −1} after 50 cycles at 0.25 mA cm{sup −2}. Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process.

  13. Effects of Sulfurization Temperature on Properties of CZTS Films by Vacuum Evaporation and Sulfurization Method

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2013-01-01

    Full Text Available Copper zinc tin sulfur (CZTS thin films have been extensively studied in recent years for their advantages of low cost, high absorption coefficient (≥104 cm−1, appropriate band gap (~1.5 eV, and nontoxicity. CZTS thin films are promising materials of solar cells like copper indium gallium selenide (CIGS. In this work, CZTS thin films were prepared on glass substrates by vacuum evaporation and sulfurization method. Sn/Cu/ZnS (CZT precursors were deposited by thermal evaporation and then sulfurized in N2 + H2S atmosphere at temperatures of 360–560°C to produce polycrystalline CZTS thin films. It is found that there are some impurity phases in the thin films with the sulfurization temperature less than 500°C, and the crystallite size of CZTS is quite small. With the further increase of the sulfurization temperature, the obtained thin films exhibit preferred (112 orientation with larger crystallite size and higher density. When the sulfurization temperature is 500°C, the band gap energy, resistivity, carrier concentration, and mobility of the CZTS thin films are 1.49 eV, 9.37 Ω · cm, 1.714×1017 cm−3, and 3.89 cm2/(V · s, respectively. Therefore, the prepared CZTS thin films are suitable for absorbers of solar cells.

  14. Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

    International Nuclear Information System (INIS)

    Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al2O3 can provide surface area for the deposition of Li2S and Li2S2. ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g−1, and the remaining capacity was 585 mAh g−1 after 50 cycles at 0.25 mA cm−2. Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process

  15. A new study of an old sink of sulfur in hot molecular cores: the sulfur residue

    CERN Document Server

    Woods, Paul M; Viti, Serena; Kanuchova, Z; Palumbo, Maria Elisabetta; Price, Stephen D

    2015-01-01

    Sulfur appears to be depleted by an order of magnitude or more from its elemental abundance in star-forming regions. In the last few years, numerous observations and experiments have been performed in order to to understand the reasons behind this depletion without providing a satisfactory explanation of the sulfur chemistry towards high-mass star-forming cores. Several sulfur-bearing molecules have been observed in these regions, and yet none are abundant enough to make up the gas-phase deficit. Where, then, does this hidden sulfur reside? This paper represents a step forward in our understanding of the interactions among the various S-bearing species. We have incorporated recent experimental and theoretical data into a chemical model of a hot molecular core in order to see whether they give any indication of the identity of the sulfur sink in these dense regions. Despite our model producing reasonable agreement with both solid-phase and gas-phase abundances of many sulfur-bearing species, we find that the s...

  16. Humic sulfur in eutrophic bay sediments: Characterization by sulfur stable isotopes and K-edge XANES spectroscopy

    Science.gov (United States)

    Zhu, Mao-Xu; Chen, Liang-Jin; Yang, Gui-Peng; Huang, Xiang-Li; Ma, Chen-Yan

    2014-02-01

    Organic sulfur (OS) is an important sedimentary sulfur pool in marine sediments and chemical extractions are often used for quantification of various OS pools, however, OS sources and mechanisms of OS formation are not well understood. In this study, sulfur stable isotope and sulfur X-ray absorption near edge structure (XANES) spectroscopy were combined to investigate the sources and speciation of humic-acid sulfur (HA-S) and fulvic-acid sulfur (FA-S) in sediments of eutrophic Jiaozhou Bay. Whilst there may be some indication that eutrophication has enhanced FA-S burial in the sediment, this has not substantially modified the characteristically low humic sulfur (i.e., HA-S + FA-S) contents of the sediments. Sulfur isotopic compositions indicate that both HA-S and FA-S are mixtures of diagenetic and biosynthetic OS in origin; HA-S is dominated by biosynthetic sulfur and FA-S by diagenetic source. Sulfur isotopic compositions and contents of pyrite and diagenetic OS indicate that inhibition of sulfurization by pyrite formation, if any, appears insignificant. XANES analysis suggests that the contents of high oxidized OS (i.e., sulfones and ester-sulfates) and strongly reduced OS species are comparable in the HA-S, whereas the FA-S is dominated by strongly reduced OS as a result of enhanced sulfurization.

  17. Sulfur dimers adsorbed on Au(111) as building blocks for sulfur octomers formation: A density functional study

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Tamargo, Carlos E.; Montero-Alejo, Ana Lilian [Laboratory of Computational and Theoretical Chemistry (LQCT), Faculty of Chemistry, Havana University, Havana 10400 (Cuba); Pujals, Daniel Codorniu [Higher Institute of Technologies and Applied Sciences (InSTEC), Havana 10400 (Cuba); Mikosch, Hans [Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/E164-EC, 1060 Vienna (Austria); Hernández, Mayra P., E-mail: mayrap@imre.oc.uh.cu [Instituto de Ciencias y Tecnologías de Materiales (IMRE), Havana 10400 (Cuba)

    2014-07-28

    Experimental scanning tunneling microscopy (STM) studies have shown for more than two decades rectangular formations when sulfur atoms are deposited on Au(111) surfaces. The precursors have ranged from simple molecules or ions, such as SO{sub 2} gas or sulfide anions, to more complex organosulfur compounds. We investigated, within the framework of the Density Functional Theory, the structure of these rectangular patterns assuming them entirely composed of sulfur atoms as the experimental evidence suggests. The sulfur coverage at which the simulations were carried out (0.67 ML or higher) provoked that the sulfur-sulfur association had to be taken into account for achieving a good agreement between the sets of simulated and experimental STM images. A combination of four sulfur dimers per rectangular formation properly explained the trends obtained by the experimental STM analysis which were related with the rectangles' size and shape fluctuations together with sulfur-sulfur distances within these rectangles. Finally, a projected density of states analysis showed that the dimers were capable of altering the Au(5d) electronic states at the same level as atomic sulfur adsorbed at low coverage. Besides, sulfur dimers states were perfectly distinguished, whose presence near and above the Fermi level can explain both: sulfur-sulfur bond elongation and dimers stability when they stayed adsorbed on the surface at high coverage.

  18. Method to prevent sulfur accumulation in membrane electrode assembly

    Science.gov (United States)

    Steimke, John L; Steeper, Timothy J; Herman, David T

    2014-04-29

    A method of operating a hybrid sulfur electrolyzer to generate hydrogen is provided that includes the steps of providing an anolyte with a concentration of sulfur dioxide, and applying a current. During steady state generation of hydrogen a plot of applied current density versus concentration of sulfur dioxide is below a boundary line. The boundary line may be linear and extend through the origin of the graph with a slope of 0.001 in which the current density is measured in mA/cm2 and the concentration of sulfur dioxide is measured in moles of sulfur dioxide per liter of anolyte.

  19. The significance of glucosinolates for sulfur storage in Brassicaceae seedlings

    OpenAIRE

    Luit J. eDe Kok

    2014-01-01

    Brassica juncea seedlings contained a two-fold higher glucosinolate content than Brassica rapa and these secondary sulfur compounds accounted for up to 30 % of the organic sulfur fraction. The glucosinolate content was not affected by H2S and SO2 exposure, demonstrating that these sulfur compounds did not form a sink for excessive atmospheric supplied sulfur. Upon sulfate deprivation, the foliarly absorbed H2S and SO2 replaced sulfate as the sulfur source for growth of B. juncea and B. rapa s...

  20. Experiments on contrail formation from fuels with different sulfur content

    Energy Technology Data Exchange (ETDEWEB)

    Busen, R.; Kuhn, M.; Petzold, A.; Schroeder, F.; Schumann, U. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany); Baumgardner, D. [National Center for Atmospheric Research, Boulder, CO (United States); Borrmann, S. [Mainz Univ. (Germany); Hagen, D.; Whitefield, Ph. [Missouri Univ., Rolla, MO (United States). Bureau of Mines; Stroem, J. [Stockholm Univ. (Sweden)

    1997-12-31

    A series of both flight tests and ground experiments has been performed to evaluate the role of the sulfur contained in kerosene in condensation trail (contrail) formation processes. The results of the first experiments are compiled briefly. The last SULFUR 4 experiment dealing with the influence of the fuel sulfur content and different appertaining conditions is described in detail. Different sulfur mass fractions lead to different particle size spectra. The number of ice particles in the contrail increases by about a factor of 2 for 3000 ppm instead of 6 ppm sulfur fuel content. (author) 10 refs.

  1. Transient Studies of a Sodium Sulfur Cell

    Science.gov (United States)

    Caprio, Sarah

    Modern grids will include input from fossil-fueled power generation facilities as well as renewable energy sources, and these are expected to work together actively. One major problem with this integrated power production is that most renewable energy sources are intermittent and variable, and thus introduce a very challenging situation with regard to grid stability and reliability. Also, fossil-fueled power generation facilities have load cycles based on expected usage. A non-reliable power source cannot feasibly be used to supply the grid with proper amounts of energy needed in peak times. A solution to this dilemma is power storage. The sodium-sulfur battery has high potential for electrical storage at the grid level due to its high energy density, low cost of the reactants, and high open-circuit voltage. However, the use of sodium-sulfur batteries at the grid level requires high current density operation that can cause cell deterioration, leading to lower sulfur utilization and lower energy efficiency. In addition, it can result in undesired thermal runaway leading to potentially hazardous situations. A rigorous, dynamic model of a sodium-sulfur battery can be used to study these phenomena, design the battery for optimal transient performance, and develop mitigation strategies. Most literature on sodium-sulfur batteries is concerned the dynamics of the sulfur electrode (a sodium-polysulfide melt). There is limited data in the open literature for dynamics of an entire cell. With this motivation, a first-principles dynamic model of a sodium-sulfur cell (with beta"-alumina electrolyte) has been developed. The state of discharge (SOD) of a sodium-sulfur cell significantly affects the heat generation rate, rates of electrochemical reactions, and internal resistance. To capture these phenomena correctly, a fully coupled thermal-electrochemical model has been developed. The thermal model considers heat generation due to Ohmic loss, Peltier heat, and heat due to the

  2. Gene expression system in green sulfur bacteria by conjugative plasmid transfer.

    Directory of Open Access Journals (Sweden)

    Chihiro Azai

    Full Text Available Gene transfer and expression systems in green sulfur bacteria were established by bacterial conjugation with Escherichia coli. Conjugative plasmid transfer from E. coli S17-1 to a thermophilic green sulfur bacterium, Chlorobaculum tepidum (formerly Chlorobium tepidum WT2321, was executed with RSF1010-derivative broad-host-range plasmids, named pDSK5191 and pDSK5192, that confer erythromycin and streptomycin/spectinomycin resistance, respectively. The transconjugants harboring these plasmids were reproducibly obtained at a frequency of approximately 10(-5 by selection with erythromycin and a combination of streptomycin and spectinomycin, respectively. These plasmids were stably maintained in C. tepidum cells in the presence of these antibiotics. The plasmid transfer to another mesophilic green sulfur bacterium, C. limnaeum (formerly Chlorobium phaeobacteroides RK-j-1, was also achieved with pDSK5192. The expression plasmid based on pDSK5191 was constructed by incorporating the upstream and downstream regions of the pscAB gene cluster on the C. tepidum genome, since these regions were considered to include a constitutive promoter and a ρ-independent terminator, respectively. Growth defections of the ∆cycA and ∆soxB mutants were completely rescued after introduction of pDSK5191-cycA and -soxB that were designed to express their complementary genes. On the other hand, pDSK5191-6xhis-pscAB, which incorporated the gene cluster of 6xhis-pscA and pscB, produced approximately four times more of the photosynthetic reaction center complex with His-tagged PscA as compared with that expressed in the genome by the conventional natural transformation method. This expression system, based on conjugative plasmid, would be applicable to general molecular biological studies of green sulfur bacteria.

  3. The fate of sulfur during rapid pyrolysis of scrap tires.

    Science.gov (United States)

    Hu, Hongyun; Fang, Yuan; Liu, Huan; Yu, Ren; Luo, Guangqian; Liu, Wenqiang; Li, Aijun; Yao, Hong

    2014-02-01

    The fate of sulfur during rapid pyrolysis of scrap tires at temperatures from 673 to 1073K was investigated. Sulfur was predominant in the forms of thiophenic and inorganic sulfides in raw scrap tires. In the pyrolysis process, sulfur in organic forms was unstable and decomposed, leading to the sulfur release into tar and gases. At 673 and 773K, a considerable amount of sulfur was distributed in tar. Temperature increasing from 773 to 973K promoted tar decomposition and facilitated sulfur release into gases. At 1073K, the interactions between volatiles and char stimulated the formation of high-molecular-weight sulfur-containing compounds. After pyrolysis, almost half of the total content of sulfur in raw scrap tires still remained in the char and was mostly in the form of sulfides. Moreover, at temperatures higher than 873K, part of sulfur in the char was immobilized in the sulfates. In the pyrolysis gases, H2S was the main sulfur-containing gas. Increasing temperature stimulated the decomposition of organic polymers in scrap tires and more H2S was formed. Besides H2S, other sulfur-containing gases such as CH3SH, COS and SO2 were produced during the rapid pyrolysis of scrap tires. PMID:24238304

  4. Analyzing Sulfur Dioxide Emissions of Nyamuragira Volcano

    Science.gov (United States)

    Guth, A. L.; Bluth, G. J.; Carn, S. A.

    2002-05-01

    Nyamuragira volcano, located in the Democratic Republic of Congo, is Africa's most active volcano, having erupted 13 times (every 1-3 years) since 1980. The eruption frequency, and the large amounts of sulfur dioxide emitted by this rift volcano, may produce a significant impact on the global sulfur budget. In this project we are attempting to quantify the sulfur dioxide emissions from this volcano over the past 20+ years using satellite data. Since 1978, satellites carrying NASA's Total Ozone Mapping Spectrometer (TOMS) instruments have been orbiting the earth collecting atmospheric data. These instruments use six wavelength bands located within the ultraviolet spectrum to measure solar irradiance and the energy reflected and backscattered by the Earth's surface and atmosphere. Sunlit planetary coverage is provided once per day by TOMS data. The spatial resolution of these satellites varies from 24 km (Earth Probe, 1996-1997, but raised to 39 km from 1997 to present) to 62 km (Meteor-3, 1991-1994). Nimbus-7, the satellite operating for the longest span of time (1978-1993), had a nadir footprint of 50 km. The (instantaneous) mass retrievals of sulfur dioxide cloud masses are derived using several different image processing schemes and net tonnages are calculated using a background correction. Volcanic activity associated with this volcano typically consists of long term (weeks to months), and often continuous, effusive emissions. Work to date has discovered over 120 days in which sulfur dioxide plumes were observed from the 13 eruptions (ranging from a minimum of one day to a maximum of 32 days). Most (82%) of the sulfur dioxide clouds measured are relatively low-level, below 100 kilotonnes (kt); 16% of the emissions are between 100 and 1000 kt, and 1.5% were measured to have more than 1000 kt. Current work is focusing on deriving net emission fluxes, integrating the TOMS instantaneous measurements of relatively continuous emission activity. The eruptive activity

  5. Bacterial sulfur cycle shapes microbial communities in surface sediments of an ultramafic hydrothermal vent field

    DEFF Research Database (Denmark)

    Schauer, Regina; Røy, Hans; Augustin, Nico;

    2011-01-01

    The ultramafic-hosted Logatchev hydrothermal field (LHF) is characterized by vent fluids, which are enriched in dissolved hydrogen and methane compared with fluids from basalt-hosted systems. Thick sediment layers in LHF are partly covered by characteristic white mats. In this study, these...

  6. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    This PhD project was carried out as part of the Microbial Remediation of Contaminated Soil and Water Resources (MIRESOWA) project, funded by the Danish Council for Strategic Research (grant number 2104-08-0012). The environment is contaminated with various xenobiotic compounds e.g. pesticides......D student, to construct fungal-bacterial consortia in order to potentially stimulate pesticide degradation thereby increasing the chance of successful bioaugmentation. The results of the project are reported in three article manuscripts, included in this thesis. In manuscript I, the mineralization of 2...

  7. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte; Kruse, Torben; Nordström, Kurt

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the P......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  8. Bacterial terpene cyclases.

    Science.gov (United States)

    Dickschat, Jeroen S

    2016-01-01

    Covering: up to 2015. This review summarises the accumulated knowledge about characterised bacterial terpene cyclases. The structures of identified products and of crystallised enzymes are included, and the obtained insights into enzyme mechanisms are discussed. After a summary of mono-, sesqui- and diterpene cyclases the special cases of the geosmin and 2-methylisoborneol synthases that are both particularly widespread in bacteria will be presented. A total number of 63 enzymes that have been characterised so far is presented, with 132 cited references. PMID:26563452

  9. Sulfur systematics in model glass compositions from West Valley

    International Nuclear Information System (INIS)

    Sulfur is incorporated into model glass melts, representative of West Valley compositions for the vitrification of high level nuclear waste, as the sulfate ion under oxidizing conditions and as the sulfide ion under reducing conditions. A narrow range of oxygen fugacities, around 10-8.8 atm at 1150 degrees C, under which the two redox forms of sulfur coexist is also the minimum in the sulfur solubility. Under the redox conditions prescribed for waste processing, sulfur dissolves as the sulfate ion. The capacity to dissolve sulfur as sulfate is about 1 to 2.5 wt% sulfur; an immiscible sulfate layer floats on the glass melt if waste loading introduces sulfur contents greater than this under oxidizing conditions. If the waste/melt system is exposed to sufficiently reducing conditions, the first phase to separate from the melt is likely nickel sulfide. The presence of the immiscible sulfate or sulfide layer buffers the iron redox ratio of the resulting glass

  10. Study on Effect of Compounding Sulfurized Isobutylene with Thioester

    Institute of Scientific and Technical Information of China (English)

    Li Hongjun; Qiu Yansheng

    2002-01-01

    Oxygen is introduced into the sulfurized isobutylene by compounding the sulfurized isobutylene with thioester. This paper studies the synergistic effect of commingling the sulfurized isobutylene with thioester during testing in the four-ball machine and the high-speed Timken machine. Tests in the four-ball machine and the high-speed Timken machine have revealed an improvement in EP performance of sulfurized isobutylene in admixture with thioester. The interfacial tension test and electrochemical analysis of anodic polarization have discovered increase of adsorptive force of the additive package on metal surface following compounding sulfurized isobutylene with thioester. The XPS and AES analyses indicate to the formation of FeS, Fe203 and FeSO4 on the metal surface. The sulfurized film formed by the additive package on the metal surface is thicker than that formed by simple sulfurized isobutylene.

  11. Plant sulfur nutrition: From Sachs to Big Data.

    Science.gov (United States)

    Kopriva, Stanislav

    2015-01-01

    Together with water and carbon dioxide plants require 14 essential mineral nutrients to finish their life cycle. The research in plant nutrition can be traced back to Julius Sachs, who was the first to experimentally prove the essentiality of mineral nutrients for plants. Among those elements Sachs showed to be essential is sulfur. Plant sulfur nutrition has been not as extensively studied as the nutrition of nitrogen and phosphate, probably because sulfur was not limiting for agriculture. However, with the reduction of atmospheric sulfur dioxide emissions sulfur deficiency has become common. The research in sulfur nutrition has changed over the years from using yeast and algae as experimental material to adopting Arabidopsis as the plant model as well as from simple biochemical measurements of individual parameters to system biology. Here the evolution of sulfur research from the times of Sachs to the current Big Data is outlined. PMID:26305261

  12. Plant sulfur nutrition: From Sachs to Big Data

    Science.gov (United States)

    Kopriva, Stanislav

    2015-01-01

    Together with water and carbon dioxide plants require 14 essential mineral nutrients to finish their life cycle. The research in plant nutrition can be traced back to Julius Sachs, who was the first to experimentally prove the essentiality of mineral nutrients for plants. Among those elements Sachs showed to be essential is sulfur. Plant sulfur nutrition has been not as extensively studied as the nutrition of nitrogen and phosphate, probably because sulfur was not limiting for agriculture. However, with the reduction of atmospheric sulfur dioxide emissions sulfur deficiency has become common. The research in sulfur nutrition has changed over the years from using yeast and algae as experimental material to adopting Arabidopsis as the plant model as well as from simple biochemical measurements of individual parameters to system biology. Here the evolution of sulfur research from the times of Sachs to the current Big Data is outlined. PMID:26305261

  13. Three-dimensional porous carbon composites containing high sulfur nanoparticle content for high-performance lithium–sulfur batteries

    OpenAIRE

    Li, Guoxing; Sun, Jinhua; Hou, Wenpeng; Jiang, Shidong; Huang, Yong; Geng, Jianxin

    2016-01-01

    Sulfur is a promising cathode material for lithium–sulfur batteries because of its high theoretical capacity (1,675 mA h g−1); however, its low electrical conductivity and the instability of sulfur-based electrodes limit its practical application. Here we report a facile in situ method for preparing three-dimensional porous graphitic carbon composites containing sulfur nanoparticles (3D S@PGC). With this strategy, the sulfur content of the composites can be tuned to a high level (up to 90 wt%...

  14. Are we getting enough sulfur in our diet?

    Directory of Open Access Journals (Sweden)

    Han Bo

    2007-11-01

    Full Text Available Abstract Sulfur, after calcium and phosphorus, is the most abundant mineral element found in our body. It is available to us in our diets, derived almost exclusively from proteins, and yet only 2 of the 20 amino acids normally present in proteins contains sulfur. One of these amino acids, methionine, cannot be synthesized by our bodies and therefore has to be supplied by the diet. Cysteine, another sulfur containing amino acid, and a large number of key metabolic intermediates essential for life, are synthesized by us, but the process requires a steady supply of sulfur. Proteins contain between 3 and 6% of sulfur amino acids. A very small percentage of sulfur comes in the form of inorganic sulfates and other forms of organic sulfur present in foods such as garlic, onion, broccoli, etc. The minimal requirements (RDA for all the essential amino acids have always been estimated in terms of their ability to maintain a nitrogen balance. This method asses amino acid requirements for protein synthesis, only one of the pathways that methionine follows after ingestion. To adequately evaluate the RDA for methionine, one should perform, together with a nitrogen balance a sulfur balance, something never done, neither in humans nor animals. With this in mind we decided to evaluate the dietary intake of sulfur (as sulfur amino acids in a random population and perform sulfur balance studies in a limited number of human volunteers. Initially this was done to try and gain some information on the possible mode of action of a variety of sulfur containing compounds (chondroitin sulfate, glucosamine sulfate, and others, used as dietary supplements to treat diseases of the joints. Out of this study came information that suggested that a significant proportion of the population that included disproportionally the aged, may not be receiving sufficient sulfur and that these dietary supplements, were very likely exhibiting their pharmacological actions by supplying

  15. Imaging of non-small cell lung cancers with a monoclonal antibody, KC-4G3, which recognizes a human milk fat globule antigen

    International Nuclear Information System (INIS)

    To determine the role of lung cancer tumor imaging with monoclonal antibodies directed against high molecular weight human milk fat globule antigens, we administered i.v. 111In-KC-4G3 to 24 patients with advanced non-small cell lung cancer. One mg of 111In-KC-4G3 was mixed with 0, 9, 49, 99, or 499 mg of unlabeled KC-4G3 and infused i.v. over 1 to 5 h. The mean 111In-KC-4G3 radiochemical purity was greater than 97% and the resultant immunoreactivity averaged 62%. Successful imaging of cancer sites was accomplished in 92% of 24 patients, and 57% of 91 total lesions were visualized. Successful localization of tumor sites related to size (P less than 0.001), with 81% of lesions greater than 3.0 cm in diameter, 50% of lesions 1.5 to 3 cm, and 6% of lesions less than 1.5 cm successfully imaging, and to location (P less than 0.05), with 69% of pulmonary lesions, 80% of soft tissue lesions, and only 32% of bone metastases being visualized. Nonspecific reticulo-endothelial uptake of radioactivity was a major problem. Approximately 35% of 111In was chelated to serum transferrin by 24 and 48 h after infusion. The mean t 1/2 beta for plasma radioisotope and immunoreactive KC-4G3 was 29 and 27 h, respectively. There was no correlation between total infused antibody dose and imaging success or between total dose and effect on 111In and KC-4G3 kinetics. Circulating free KC-4 antigen was measurable in all but one patient before study. Tumor biopsy following infusion could demonstrate antibody presence but not saturable antigen binding. We conclude that (a) 111In-KC-4G3 demonstrates successful tumor localization in non-small cell lung cancers bearing generally high expression of its antigen and (b) further investigations to diminish nonspecific radioactivity for imaging and utilization of high dose radiolabeled antibody for therapeutic intent are warranted

  16. Multiple sulfur and carbon isotope composition of sediments from the Belingwe Greenstone Belt (Zimbabwe): A biogenic methane regulation on mass independent fractionation of sulfur during the Neoarchean?

    Science.gov (United States)

    Thomazo, Christophe; Nisbet, Euan G.; Grassineau, Nathalie V.; Peters, Marc; Strauss, Harald

    2013-11-01

    Formation), respectively. This differs from the Archean reference line (i.e. -0.9). The sulfur and carbon isotopic signatures recorded here likely reflect different environmental conditions and/or ecosystems within the sampled Cheshire and Manjeri formations paleofacies. The differences in carbon isotopes in different sedimentological facies are interpreted as recording different metabolic pathways, including photosynthesis, methanogenesis and methanotrophy. Low δ13Corg values in the Cheshire Formation black shales suggest a strong influence of methanotrophy (likely preceded by bacterial methanogenesis), while the large range of Manjeri Formation δ34S may record bacterial sulfate reduction. The C and multiple S isotopic variations recorded here may imply different patterns of C and S fractionation, perhaps dependent on variations in the biogenic egress of methane to the atmosphere.

  17. Bacterial contamination of enteral diets.

    OpenAIRE

    de Leeuw, I H; Vandewoude, M F

    1986-01-01

    Enteral feeding solutions can be contaminated by bacterial micro-organisms already present in the ingredients, or introduced during preparation or transport, or in the hospital ward. During jejunostomy feeding without pump or filter, ascending bacterial invasion of the feeding bag is possible. In patients with lowered immune response contaminated feedings can cause serious septic clinical problems. The progressive loss of the nutritional value of the enteral feeding solution by bacterial cont...

  18. Transport powered by bacterial turbulence

    OpenAIRE

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-01-01

    We demonstrate that collective turbulent-like motion in a bacterial bath can power and steer directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedge-like "bulldozer" draws energy from a bacterial bath of varied density. We obtain that a maximal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp regi...

  19. 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.

  20. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M;

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...... susceptibility occurred in 21 (23%) of 92 cases of known aetiology, compared to an estimated 6% in nationally notified cases (p <0.001). Ceftriaxone plus penicillin as empirical treatment was appropriate in 97% of ABM cases in the study population, and in 99.6% of nationally notified cases. The notification rate...... was 75% for penicillin-susceptible episodes, and 24% for penicillin-non-susceptible episodes (p <0.001). Cases involving staphylococci, Pseudomonas spp. and Enterobacteriaceae were under-reported. Among 51 ABM cases with no identified risk factors, nine of 11 cases with penicillin...

  1. [Endogenous bacterial endophthalmitis].

    Science.gov (United States)

    Cornut, P-L; Chiquet, C

    2011-01-01

    Endogenous bacterial endophthalmitis, also called metastatic bacterial endophthalmitis, remains a diagnostic and therapeutic challenge. It is a rare and potentially sight-threatening ocular infection that occurs when bacteria reach the eye via the bloodstream, cross the blood-ocular barrier, and multiply within the eye. It usually affects immunocompromised patients and those suffering from diabetes mellitus, malignancy, or cardiac disease, but has also been reported after invasive procedures or in previously healthy people. In most cases, the ocular symptoms occur after the diagnosis of septicemia or systemic infection. Ocular symptoms include decreased vision, redness, discharge, pain, and floaters. The ocular inflammatory signs may be anterior and/or posterior. Bilateral involvement occurs in nearly 25% of cases. A wide range of microorganisms are involved, with differences in their frequency according to geography as well as the patient's age and past medical history, because of variations in the predisposing conditions and the source of the sepsis. The majority of patients are initially misdiagnosed, and ophthalmologists should be aware of this because prompt local and general management is required to save the eye and/or the patient's life. PMID:21145128

  2. Proton scattering by short lived sulfur isotopes

    International Nuclear Information System (INIS)

    Elastic and inelastic proton scattering has been measured in inverse kinematics on the unstable nucleus 40S. A phenomenological DWBA analysis yields a quadrupole deformation parameter β2 = 0.35 ± 0.05 for the 2+1 state. Consistent phenomenological and microscopic proton scattering analyses have been applied to all even-even Sulfur isotopes from A = 32 to A = 40. The microscopic analysis used microscopic collective model densities and a modified Jeukenne-Lejeune-Mahaux effective interaction. This analysis suggests the presence of a neutron skin in the heavy sulfur isotopes. The analysis is consistent with normalization values for λυ and λω of 0.95 for both the real and imaginary parts of the JLM potential. (author)

  3. Nutrition Research Progress of Sulfur in Ruminant%硫在反刍动物中的营养研究进展

    Institute of Scientific and Technical Information of China (English)

    郑帅; 刘大森

    2011-01-01

    Sulfur is one of the mineral essential elements for the ruminant animal and also the essential element for bacterial protein synthesis. This paper reviewed the distribution and metabolism of sulfur in ruminant animals, the relationship between the sulfur and other nutrients and requirements in the production.%硫是反刍动物必需矿物元素之一,也是合成菌体蛋白的必需元素。文章就硫在反刍动物体内的分布、代谢、和其他营养成分的关系及在生产中的需要量等方面进行了综述。

  4. Periodic growth of bacterial colonies

    Science.gov (United States)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  5. Sulfur Mustard Toxicity Following Dermal Exposure

    OpenAIRE

    Paromov, Victor; Suntres, Zacharias; Smith, Milton; Stone, William L

    2007-01-01

    Objective: Sulfur mustard (bis-2-(chloroethyl) sulfide) is a chemical warfare agent (military code: HD) causing extensive skin injury. The mechanisms underlying HD-induced skin damage are not fully elucidated. This review will critically evaluate the evidence showing that oxidative stress is an important factor in HD skin toxicity. Oxidative stress results when the production of reactive oxygen (ROS) and/or reactive nitrogen oxide species (RNOS) exceeds the capacity of antioxidant defense mec...

  6. Sulfur hexafluoride - A powerful new atmospheric tracer

    OpenAIRE

    Maiss, Manfred; Steele, Paul; Francey, Roger; Fraser, Paul; Langenfelds, Ray; Trivett, Neil; Levin, Ingeborg

    1996-01-01

    Long-term observations of the atmospheric trace gas sulfur hexafluoride (SF6) at four background monitoring stations, Neumayer, Antarctica (1986-1994), Cape Grim, Tasmania (1978-1994), Izana, Canary Islands (1991-1994) and Alert, Canada (1993-1994) are presented. These data sets are supplemented by two meridional profiles collected over the Atlantic Ocean (1990 and 1993) and occasional observations at the regional site Fraserdale, Canada (1994). The analytical system and the method of SF6 cal...

  7. Sulfur-functional polymers for biomedical applications

    OpenAIRE

    Kuhlmann, Matthias

    2015-01-01

    Aim of this thesis was to combine the versatility of sulfur-chemistry, regarding redox-sensitivity as well as chemo- and site-specific conjugation, with multifunctionality of poly(glycidol)s as an alternative to poly(ethylene glycol). First the homo- and copolymerizations of EEGE and AGE were performed with respect to molar-mass distribution and reaction kinetics. A detailed study was given, varying the polymerization parameters such as DP, counter ion, solvent and monomer influence. It c...

  8. Sulfur Oxidation and Contrail Precursor Chemistry

    Science.gov (United States)

    DeWitt, Kenneth J.

    2003-01-01

    Sulfuric acid (H2SO4), formed in commercial aircraft operations via fuel-S (goes to) SO2 (goes to) SO3 (goes to) H2SO4 plays an important role in the formation of contrails. It is believed that the first step occurs inside the combustor, the second step in the engine exit nozzle, and the third step in the exhaust plume. Thus, measurements of the sulfur oxidation rates are critical to the understanding of contrail formation. Field measurements of contrails formed behind commercial aircraft indicate that significantly greater conversion of fuel-bound sulfur to sulfate aerosol occurs than can be explained by our current knowledge of contrail physics and chemistry. The conversion of sulfur from S(IV) to S(VI) oxidation state, required for sulfate aerosol formation, is thermodynamically favored for the conditions that exist within jet engines but is kinetically disfavored. The principal reaction pathway is O+SO2+M (goes to) SO3+M. The rates of this reaction have never been measured in the temperature and pressure regimes available to aircraft operation. In the first year (FY02) of this project, we performed a series of experiments to elucidate the rate information for the O+SO2+M (goes to) SO3+M reaction. The work performed is described following the proposed work plan. Because we used the H2/O2 system for an O-atom source and rate coefficients were obtained via computer simulation, construction of a reaction mechanism and either recalculation or estimation of thermodynamic properties of H(x)SO(y) species are described first.

  9. Biological effects data: Fluoride and sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, K.J. (ed.); Holton, R.L.; Ulbricht, R.J.; Morgan , J.B.

    1975-04-01

    The Alumax Pacific Aluminum Corporation has proposed construction of an aluminum reduction facility near Youngs Bay at Warrenton, Oregon. This report comprises one part of the final report to Alumax on a research project entitled, Physical, Chemical and Biological Studies of Youngs Bay.'' It presents data pertaining to the potential biological effects of fluoride and sulfur dioxide, two potentially hazardous plant-stack emissions, on selected aquatic species of the area. Companion volumes provide a description of the physical characteristics the geochemistry, and the aquatic animals present in Youngs Bay and adjacent ecosystems. An introductory volume provides general information and maps of the area, and summarizes the conclusions of all four studies. The data from the two phases of the experimental program are included in this report: lethal studies on the effects of selected levels of fluoride and sulfur dioxide on the survival rate of eleven Youngs Bay faunal species from four phyla, and sublethal studies on the effects of fluoride and sulfur dioxide on the rate of primary production of phytoplankton. 44 refs., 18 figs., 38 tabs.

  10. Sulfur aerosol in the clouds of Venus

    Science.gov (United States)

    Krasnopolsky, Vladimir A.

    2016-08-01

    The photochemical model for the middle atmosphere of Venus (Krasnopolsky, V.A. [2012] Icarus, 218, 230-246) predicts sulfur aerosol as a product of the OCS photolysis at 55-60 km. The calculated mass loading is much smaller than that of the mode 1 particles in the upper cloud layer. The chemical kinetic model for the lower atmosphere (Krasnopolsky, V.A. [2013], Icarus, 225, 570-580) results in a constant mixing ratio of 20 ppm for OCS + XSX. This means the S8 mixing ratio of 2.5 ppm near the model upper boundary at 47 km. Using this abundance, the calculated profile of the sulfur aerosol has a bottom that coincides with the lower boundary of modes 2 and 3 and constitutes ∼10% of the total mass loading in the lower cloud layer. Sulfur aerosol cannot be the near UV absorber because its abundance is too low at the cloud tops and disagrees with the profile of the absorber observed by Venera 14.

  11. Sulfur status in long distance runners

    Science.gov (United States)

    Kovacs, L.; Zamboni, C.; Lourenço, T.; Macedo, D.

    2015-07-01

    In sports medicine, sulfur plays an important role and its deficiency can cause muscle injury affecting the performance of the athletes. However, its evaluation is unusual in conventional clinical practice. In this study the sulfur levels were determined in Brazilian amateur athlete's blood using Neutron Activation Analyses (NAA) technique. Twenty six male amateur runners, age 18 to 36 years, participated of this study. The athletes had a balanced diet, without multivitamin/mineral supplements. The blood collection was performed at LABEX (Laboratoriode Bioquimica do Exercicio, UNICAMP-SP) and the samples were irradiated for 300 seconds in a pneumatic station in the nuclear reactor (IEA-R1, 3-4.5MW, pool type) at IPEN/CNEN-SP. The results were compared with the control group (subjects of same age but not involved with physical activities) and showed that the sulfur concentration was 44% higher in amateurs athletes than control group. These data can be considered for preparation of balanced diet, as well as contributing for proposing new protocols of clinical evaluation.

  12. Sulfur biogeochemistry of oil sands composite tailings

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Lesley; Stephenson, Kate [Earth Sciences, McMaster University (Canada)], email: warrenl@mcmaster.ca; Penner, Tara [Syncrude Environmental Research (Canada)

    2011-07-01

    This paper discusses the sulfur biogeochemistry of oil sands composite tailings (CT). The Government of Alberta is accelerating reclamation activities on composite tailings. As a CT pilot reclamation operation, Syncrude is currently constructing the first freshwater fen. Minor unpredicted incidents with H2S gas released from the dewatering process associated with these reclamations have been reported. The objective of this study is to ascertain the connection between microbial activity and H2S generation within CT and to assess the sulfur biogeochemistry of untreated and treated (fen) CT over seasonal and annual timescales. The microbial geochemical interactions taking place are shown using a flow chart. CT is composed of gypsum, sand, clay and organics like naphthenic acids and bitumen. Sulfur and Fe cycling in mining systems and their microbial activities are presented. The chemistry and the processes involved within CT are also given along with the results. It can be said that the diverse Fe and S metabolizing microorganisms confirm the ecology involved in H2S dynamics.

  13. Ordered mesoporous carbon/sulfur nanocomposite of high performances as cathode for lithium-sulfur battery

    Energy Technology Data Exchange (ETDEWEB)

    Chen Shuru [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005 (China); Zhai Yunpu [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Advanced Materials Laboratory, Fudan University, Shanghai 200433 (China); Xu Guiliang; Jiang Yanxia [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005 (China); Zhao Dongyuan, E-mail: dyzhao@fudan.edu.cn [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and Advanced Materials Laboratory, Fudan University, Shanghai 200433 (China); Li Juntao; Huang Ling [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005 (China); Sun Shigang, E-mail: sgsun@xmu.edu.cn [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, School of Energy Research, Xiamen University, Xiamen 361005 (China)

    2011-11-01

    Ordered mesoporous carbon/sulfur (OMC/S) nanocomposites with hierarchically structured sulfur loading, ranging from 50 to 75 wt%, were synthesized via a simple melt-diffusion strategy. The OMC with a BET surface area of 2102 m{sup 2} g{sup -1}, a pore volume of 2.0 cm{sup 3} g{sup -1} and unique bimodal mesoporous (5.6/2.3 nm) structure, was prepared from a triconstituent co-assembly method. The resulting OMC/S nanocomposite material served as cathode of rechargeable lithium-sulfur (Li-S) battery. It has been tested that the novel OMC/S cathode can deliver a superior reversible capacity and cyclability. In particular, the nanocomposite with a loading of 60 wt% sulfur (OMC/S-60) presents the highest sulfur utilization ca. 70%, an excellent high rate capability ca. 6 C and a good cycling stability for up to 400 full charge-discharge cycles. The exceptional electrochemical performances are exclusively attributed to the large internal surface area and high porosity of the ordered mesoporous carbon, which favorites both electron and Li-ion transportations.

  14. Improved Cyclability of Liquid Electrolyte Lithium/Sulfur Batteries by Optimizing Electrolyte/Sulfur Ratio

    Directory of Open Access Journals (Sweden)

    Sheng S. Zhang

    2012-12-01

    Full Text Available A liquid electrolyte lithium/sulfur (Li/S cell is a liquid electrochemical system. In discharge, sulfur is first reduced to highly soluble Li2S8, which dissolves into the organic electrolyte and serves as the liquid cathode. In solution, lithium polysulfide (PS undergoes a series of complicated disproportionations, whose chemical equilibriums vary with the PS concentration and affect the cell’s performance. Since the PS concentration relates to a certain electrolyte/sulfur (E/S ratio, there is an optimized E/S ratio for the cyclability of each Li/S cell system. In this work, we study the optimized E/S ratio by measuring the cycling performance of Li/S cells, and propose an empirical method for determination of the optimized E/S ratio. By employing an electrolyte of 0.25 m LiSO3CF3-0.25 m LiNO3 dissolved in a 1:1 (wt:wt mixture of dimethyl ether (DME and 1,3-dioxolane (DOL in an optimized E/S ratio, we show that the Li/S cell with a cathode containing 72% sulfur and 2 mg cm−2 sulfur loading is able to retain a specific capacity of 780 mAh g−1 after 100 cycles at 0.5 mA cm−2 between 1.7 V and 2.8 V.

  15. Formation of CuxS Layers on Polypropylene Sulfurized by Molten Sulfur

    Directory of Open Access Journals (Sweden)

    Rasa ALABURDAITĖ

    2011-11-01

    Full Text Available The processes of formation of electrically conductive layers of copper sulfides CuxS by the sorption-diffusion method on polypropylene (PP using molten sulfur as sulfurizing agent was investigated. The amount of sorbed sulfur increased with the increase of the duration of treatment. Copper sulfide layers were formed on the surface of polypropylene after the treatment of sulfurized polymer with Cu(II/I salt solution. The amount of copper sulfide in layer increased with the increase of treatment duration in copper salt solution. XRD spectra of PP films treated for 3 min with molten sulfur and then with Cu(II/I salt solution for the different time showed that the copper sulfide phases, mostly digenite, Cu2-xS and a-chalcocite, Cu2S were formed in the layers. Electromotive force measurement results confirmed the composition of formed CuxS layers on PP. The phase composition of layers also changed after the annealing. The value of electrical resistance of copper sulfide layers on PP varied from 20 W/cm2 to 80 W/cm2 and after annealing at 80 °C - in the interval of 10 W/cm2 - 60 W/cm2.http://dx.doi.org/10.5755/j01.ms.17.4.776

  16. The analysis of thermoplastic characteristics of special polymer sulfur composite

    Science.gov (United States)

    Książek, Mariusz

    2016-07-01

    Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot was applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The process of special polymer sulfur composite applied as the industrial waste is a thermal treatment process in the temperature of about 150-155°C. The result of such treatment is special polymer sulfur composite in a liquid state. This paper presents the plastic constants and coefficients of thermal expansion of special polymer sulfur composites, with isotropic porous matrix, reinforced by disoriented ellipsoidal inclusions with orthotropic symmetry of the thermoplastic properties. The investigations are based on the stochastic differential equations of solid mechanics. A model and algorithm for calculating the effective characteristics of special polymer sulfur composites are suggested. The effective thermoplastic characteristics of special polymer sulfur composites, with disoriented ellipsoidal inclusions, are calculated in two stages: First, the properties of materials with oriented inclusions are determined, and then effective constants of a composite with disoriented inclusions are determined on the basis of the Voigt or Rice scheme. A brief summary of new products related to special polymer sulfur composites is given as follows: Impregnation, repair, overlays and precast polymer concrete will be presented. Special polymer sulfur as polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

  17. The significance of glucosinolates for sulfur storage in Brassicaceae seedlings

    Directory of Open Access Journals (Sweden)

    Luit J. eDe Kok

    2014-12-01

    Full Text Available Brassica juncea seedlings contained a two-fold higher glucosinolate content than Brassica rapa and these secondary sulfur compounds accounted for up to 30 % of the organic sulfur fraction. The glucosinolate content was not affected by H2S and SO2 exposure, demonstrating that these sulfur compounds did not form a sink for excessive atmospheric supplied sulfur. Upon sulfate deprivation, the foliarly absorbed H2S and SO2 replaced sulfate as the sulfur source for growth of B. juncea and B. rapa seedlings. The glucosinolate content was decreased in sulfate-deprived plants, though its proportion of organic sulfur fraction was higher than that of sulfate-sufficient plants, both in absence and presence of H2S and SO2. The significance of myrosinase in the in situ turnover in these secondary sulfur compounds needs to be questioned, since there was no direct co-regulation between the content of glucosinolates and the transcript level and activity of myrosinase. Evidently, glucosinolates cannot be considered as sulfur storage compounds upon exposure to excessive atmospheric sulfur and are unlikely to be involved in the re-distribution of sulfur in B. juncea and B. rapa seedlings upon sulfate deprivation.

  18. Sulfur-induced structural motifs on copper and gold surfaces

    Science.gov (United States)

    Walen, Holly

    The interaction of sulfur with copper and gold surfaces plays a fundamental role in important phenomena that include coarsening of surface nanostructures, and self-assembly of alkanethiols. Here, we identify and analyze unique sulfur-induced structural motifs observed on the low-index surfaces of these two metals. We seek out these structures in an effort to better understand the fundamental interactions between these metals and sulfur that lends to the stability and favorability of metal-sulfur complexes vs. chemisorbed atomic sulfur. We choose very specific conditions: very low temperature (5 K), and very low sulfur coverage (≤ 0.1 monolayer). In this region of temperature-coverage space, which has not been examined previously for these adsorbate-metal systems, the effects of individual interactions between metals and sulfur are most apparent and can be assessed extensively with the aid of theory and modeling. Furthermore, at this temperature diffusion is minimal and relatively-mobile species can be isolated, and at low coverage the structures observed are not consumed by an extended reconstruction. The primary experimental technique is scanning tunneling microscopy (STM). The experimental observations presented here---made under identical conditions---together with extensive DFT analyses, allow comparisons and insights into factors that favor the existence of metal-sulfur complexes, vs. chemisorbed atomic sulfur, on metal terraces. We believe this data will be instrumental in better understanding the complex phenomena occurring between the surfaces of coinage metals and sulfur.

  19. Biosynthesis and functions of sulfur modifications in tRNA

    Directory of Open Access Journals (Sweden)

    Naoki eShigi

    2014-04-01

    Full Text Available Sulfur is an essential element for a variety of cellular constituents in all living organisms. In tRNA molecules, there are many sulfur-containing nucleosides, such as the derivatives of 2‑thiouridine (s2U, 4-thiouridine (s4U, 2-thiocytidine (s2C, and 2-methylthioadenosine (ms2A. Earlier studies established the functions of these modifications for accurate and efficient translation, including proper recognition of the codons in mRNA or stabilization of tRNA structure. In many cases, the biosynthesis of these sulfur modifications starts with cysteine desulfurases, which catalyze the generation of persulfide (an activated form of sulfur from cysteine. Many sulfur-carrier proteins are responsible for delivering this activated sulfur to each biosynthesis pathway. Finally, specific modification enzymes activate target tRNAs and then incorporate sulfur atoms. Intriguingly, the biosynthesis of 2-thiouridine in all domains of life is functionally and evolutionarily related to the ubiquitin-like post-translational modification system of cellular proteins in eukaryotes. This review summarizes the recent characterization of the biosynthesis of sulfur modifications in tRNA and the novel roles of this modification in cellular functions in various model organisms, with a special emphasis on 2-thiouridine derivatives. Each biosynthesis pathway of sulfur-containing molecules is mutually modulated via sulfur trafficking, and 2-thiouridine and codon usage bias have been proposed to control the translation of specific genes.

  20. Biosynthesis and functions of sulfur modifications in tRNA.

    Science.gov (United States)

    Shigi, Naoki

    2014-01-01

    Sulfur is an essential element for a variety of cellular constituents in all living organisms. In tRNA molecules, there are many sulfur-containing nucleosides, such as the derivatives of 2-thiouridine (s(2)U), 4-thiouridine (s(4)U), 2-thiocytidine (s(2)C), and 2-methylthioadenosine (ms(2)A). Earlier studies established the functions of these modifications for accurate and efficient translation, including proper recognition of the codons in mRNA or stabilization of tRNA structure. In many cases, the biosynthesis of these sulfur modifications starts with cysteine desulfurases, which catalyze the generation of persulfide (an activated form of sulfur) from cysteine. Many sulfur-carrier proteins are responsible for delivering this activated sulfur to each biosynthesis pathway. Finally, specific "modification enzymes" activate target tRNAs and then incorporate sulfur atoms. Intriguingly, the biosynthesis of 2-thiouridine in all domains of life is functionally and evolutionarily related to the ubiquitin-like post-translational modification system of cellular proteins in eukaryotes. This review summarizes the recent characterization of the biosynthesis of sulfur modifications in tRNA and the novel roles of this modification in cellular functions in various model organisms, with a special emphasis on 2-thiouridine derivatives. Each biosynthesis pathway of sulfur-containing molecules is mutually modulated via sulfur trafficking, and 2-thiouridine and codon usage bias have been proposed to control the translation of specific genes. PMID:24765101

  1. Development of lysozyme-combined antibacterial system to reduce sulfur dioxide and to stabilize Italian Riesling ice wine during aging process

    OpenAIRE

    Chen, Kai; Han, Shun-yu; Zhang, Bo; Li, Min; Sheng, Wen-jun

    2015-01-01

    For the purpose of SO2 reduction and stabilizing ice wine, a new antibacterial technique was developed and verified in order to reduce the content of sulfur dioxide (SO2) and simultaneously maintain protein stability during ice wine aging process. Hazardous bacterial strain (lactic acid bacteria, LAB) and protein stability of Italian Riesling ice wine were evaluated in terms of different amounts of lysozyme, SO2, polyphenols, and wine pH by single-factor experiments. Subsequently, a quadratic...

  2. Comparative Aspects of Sulfur Mineralization in Sediments of a Eutrophic Lake Basin †

    OpenAIRE

    Gary M King; Klug, M. J.

    1982-01-01

    The net mineralization of organic sulfur compounds in surface sediments of Wintergreen Lake was estimated from a mass-balance budget of sulfur inputs and sediment sulfur concentrations. The net mineralization of organic sulfur inputs is 80% of total sulfur) in sediment. Although sediment sulfur is predominantly organic, sulfate reduction is the most significant process in terms of the quantities of sulfur transformed in surface sediments. Rates of sulfate reduction in these sediments average ...

  3. Sulfur isotope ratios and the origins of the aerosols and cloud droplets in California stratus

    OpenAIRE

    Ludwig, F. L.

    2011-01-01

    Marine aerosols often have sulfur-to-chloride ratios greater than that found in seawater. Sulfur isotope ratios (34S/32S) were measured in aerosol and cloud droplet samples collected in the San Francisco Bay Area in an attempt to understand the processes that produce the observed sulfur-to-chloride ratios. Seawater sulfur usually has very high sulfur isotope ratios; fossil fuel sulfur tends to have smaller isotope ratios and sulfur of bacteriogenic origin still smaller. Samples collected in u...

  4. Contributions of organic matter and organic sulfur redox processes to electron flow in anoxic incubations of peat

    Science.gov (United States)

    YU, Zhiguo; Peiffer, Stefan; Göttlicher, Jörg; Knorr, Klaus-Holger

    2015-04-01

    Anaerobic decomposition of peat soils involves a number of interdependent microbial processes that ultimately generate CO2 and CH4. In many peat soils, a high ratio of CO2:CH4 was reported, which presumably results from a direct or indirect role of soil organic matter serving as an electron acceptor. Therefore, in this study we intended to test the hypothesis that organic matter (OM) suppresses methanogenesis and sustains anaerobic CO2 production, serving as i) direct electron acceptor or ii) via supporting internal sulfur cycling to maintains CO2 production through bacterial sulfate reduction (BSR). We incubated peat samples of commercial bog peat, inoculated with a small amount of fresh peat to introduce an active microbial community. Samples were amended with sulfate or sulfide and incubated under anoxic conditions for 6 weeks at 30 ° C. Upon anaerobic incubation of peat virtually devoid of inorganic electron acceptors, CO2 and CH4 were produced at a ratio of 3.2. According to the electron budget, the calculated electron accepting capacity (EAC) of OM was 2.36 μeq cm3 d-1. Addition of sulfate significantly increased CO2 production and effectively suppressed CH4 production. After subtracting the EAC provided though sulfate addition (0.97~2.81 μeq cm-3 d-1), EACs supplied by OM reached 3.88 to 4.85 μeq cm-3 d-1.The contribution of organic sulfur was further evaluated by XANES spectroscopy and using natural abundance of δ34S as a tracer. Results demonstrated that BSR involved both addition of H2S and sulfate to OM leading to a formation of reduced organic sulfur and partial changes of oxidized organic sulfur species. The original peat prior to incubation contained 70.5% reduced organic S (R-S-H, R-S-R, R-S-S-R), and 25.9% oxidized S (R-SO3, R-SO2-R, R-SO4-R), whereas the treatment with H2S or sulfate addition comprised 75.7~ 81.1% reduced organic S, and only 21.1~18.9 % oxidized S. Our results imply that that organic matter contributes to anaerobic respiration

  5. Preparation and performance of a sulfur/graphene composite for rechargeable lithium-sulfur battery

    International Nuclear Information System (INIS)

    The lithium-sulfur (Li-S) battery is a promising electrochemical system that has high theoretical capacity. The sulfur/graphene nanosheets (S/GNS) composite is prepared through thermal reduction between the sulfur (S) and graphene oxide (GO). The morphology and composition of the composite are analyzed by means of x-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopic (EDS) characterization. It is found that the element S distributed uniformly between the layers of GNS. Graphene with a two-dimensional structure of carbon atoms is employed as a conductive and absorbing agent for the S cathode materials of rechargeable Li-S battery. The S/GNS composite cathode shows a specific electrochemical capacity, which is about 1598 mAh g−1 S at the initial discharge and remains above 670 mAh g−1 after 80 cycles.

  6. Sulfur isotopes in coal constrain the evolution of the Phanerozoic sulfur cycle

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    2013-01-01

    reaction of sulfide with iron produces pyrite whose burial in sediments is an important oxygen source to the atmosphere. The concentrations of seawater sulfate and the operation of sulfur cycle have experienced dynamic changes through Earth’s history, and our understanding of this history is based mainly...... on interpretations of the isotope record of seawater sulfates and sedimentary pyrites. The isotope record, however, does not give a complete picture of the ancient sulfur cycle. This is because, in standard isotope mass balance models, there are more variables than constraints. Typically, in...... interpretations of the isotope record and in the absence of better information, one assumes that the isotopic composition of the input sulfate to the oceans has remained constant through time. It is argued here that this assumption has a constraint over the last 390 Ma from the isotopic composition of sulfur in...

  7. Mesoporous carbon materials prepared from litchi shell as sulfur encapsulator for lithium-sulfur battery application

    Science.gov (United States)

    Sun, Zhenjie; Wang, Shuanjin; Yan, Longlong; Xiao, Min; Han, Dongmei; Meng, Yuezhong

    2016-08-01

    Novel mesoporous carbon materials (MCMs) with excellent electron conductivity and high surface area are successfully synthesized from waste litchi shells. The as-prepared MCMs possess a narrow pore size distribution (0.5-2.0 nm) and exhibit similar electron conductivities to conductive carbon black (Super P, Timcal). Because of the unique properties of MCMs, they are used as host matrixes to encapsulate sulfur for lithium-sulfur cathodes. The obtained MCMs-sulfur (MCMs-S) composite cathodes deliver a high initial specific capacity of 1667 mAh g-1. Moreover, 300 °C treated MCMs-S composite cathode shows a more stable discharge capacity than the untreated MCMs-S composite cathode, it remains 612 mAh g-1 after 200 cycles at a high current density of 0.5 C.

  8. [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

  9. 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...

  10. Carbon/sulfur composite cathodes for flexible lithium/sulfur batteries: status and prospects

    Directory of Open Access Journals (Sweden)

    Yan eZhao

    2015-02-01

    Full Text Available High specific energy and low cost flexible lithium/sulfur batteries have attracted significant attention as a promising power source to enable future flexible and wearable electronic devices. Here, we review recent progress in the development of free-standing sulfur composite cathodes, with special emphasis on electrode material selectivity and battery structural design. The mini-review is organized based on the dimensionality of different scaffold materials, namely one dimensional carbon nanotube, two dimensional graphene and three dimensional carbon nanotube/graphene composite, respectively. Finally, the opportunities and perspectives of the future research directions are discussed.

  11. Effects of Sulfurization Temperature on Properties of CZTS Films by Vacuum Evaporation and Sulfurization Method

    OpenAIRE

    Jie Zhang; Bo Long; Shuying Cheng; Weibo Zhang

    2013-01-01

    Copper zinc tin sulfur (CZTS) thin films have been extensively studied in recent years for their advantages of low cost, high absorption coefficient (≥104 cm−1), appropriate band gap (~1.5 eV), and nontoxicity. CZTS thin films are promising materials of solar cells like copper indium gallium selenide (CIGS). In this work, CZTS thin films were prepared on glass substrates by vacuum evaporation and sulfurization method. Sn/Cu/ZnS (CZT) precursors were deposited by thermal evaporation and then s...

  12. Core-shell meso/microporous carbon host for sulfur loading toward applications in lithium-sulfur batteries

    Institute of Scientific and Technical Information of China (English)

    Juan Zhang; Huan Ye; Yaxia Yin; Yuguo Guo

    2014-01-01

    Lithium-sulfur (Li-S) batteries belong to one of the promising technologies for high-energy-density rechargeable batteries. However, sulfur cathodes suffer from inherent problems of its poor electronic conductivity and the shuttling of highly dissoluble lithium polysulfides generated during the cycles. Loading sulfur into porous carbons has been proved to be an effective approach to alleviate these issues. Mesoporous and microporous carbons have been widely used for sulfur accommodation, but mesoporous carbons have poor sulfur confinement, whereas microporous carbons are impeded by low sulfur loading rates. Here, a core-shell carbon, combining both the merits of mesoporous carbon with large pore volume and microporous carbon with effective sulfur confinement, was prepared by coating the mesoporous CMK-3 with a microporous carbon (MPC) shell and served as the carbon host (CMK-3@MPC) to accommodate sulfur. After sulfur infusion, the as-obtained S/(CMK-3@MPC) cathode delivered a high initial capacity of up to 1422 mAh·g-1 and sustained 654 mAh·g-1 reversible specific capacity after 36 cycles at 0.1 C. The good performance is ascribed to the unique core-shell structure of the CMK-3@MPC matrix, in which sulfur can be effectively confined within the meso/microporous carbon host, thus achieving simultaneously high electrochemical utilization.

  13. Sulfur speciation and bioaccumulation in camphor tree leaves as atmospheric sulfur indicator analyzed by synchrotron radiation XRF and XANES.

    Science.gov (United States)

    Zeng, Jianrong; Zhang, Guilin; Bao, Liangman; Long, Shilei; Tan, Mingguang; Li, Yan; Ma, Chenyan; Zhao, Yidong

    2013-03-01

    Analyzing and understanding the effects of ambient pollution on plants is getting more and more attention as a topic of environmental biology. A method based on synchrotron radiation X-ray fluorescence and X-ray absorption near edge structure spectroscopy was established to analyze the sulfur concentration and speciation in mature camphor tree leaves (CTLs), which were sampled from 5 local fields in Shanghai, China. Annual SO2 concentration, SO4(2-) concentration in atmospheric particulate, SO4(2-) and sulfur concentration in soil were also analyzed to explore the relationship between ambient sulfur sources and the sulfur nutrient cycling in CTLs. Total sulfur concentration in mature camphor tree leaves was 766-1704 mg/kg. The mainly detected sulfur states and their corresponding compounds were +6 (sulfate, include inorganic sulfate and organic sulfate), +5.2 (sulfonate), +2.2 (suloxides), +0.6 (thiols and thiothers), +0.2 (organic sulfides). Total sulfur concentration was strongly correlated with sulfate proportion with a linear correlation coefficient up to 0.977, which suggested that sulfur accumulated in CTLs as sulfate form. Reduced sulfur compounds (organic sulfides, thiols, thioethers, sulfoxide and sulfonate) assimilation was sufficed to meet the nutrient requirement for growth at a balanced level around 526 mg/kg. The sulfate accumulation mainly caused by atmospheric sulfur pollution such as SO2 and airborne sulfate particulate instead of soil contamination. From urban to suburb place, sulfate in mature CTLs decreased as the atmospheric sulfur pollution reduced, but a dramatic increase presented near the seashore, where the marine sulfate emission and maritime activity pollution were significant. The sulfur concentration and speciation in mature CTLs effectively represented the long-term biological accumulation of atmospheric sulfur pollution in local environment. PMID:23923435

  14. 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.

  15. Molecular Interaction of Pinic Acid with Sulfuric Acid

    DEFF Research Database (Denmark)

    Elm, Jonas; Kurten, Theo; Bilde, Merete;

    2014-01-01

    We investigate the molecular interactions between the semivolatile α-pinene oxidation product pinic acid and sulfuric acid using computational methods. The stepwise Gibbs free energies of formation have been calculated utilizing the M06-2X functional, and the stability of the clusters is evaluated...... from the corresponding ΔG values. The first two additions of sulfuric acid to pinic acid are found to be favorable with ΔG values of -9.06 and -10.41 kcal/mol. Addition of a third sulfuric acid molecule is less favorable and leads to a structural rearrangement forming a bridged sulfuric acid-pinic acid...... without the further possibility for attachment of either sulfuric acid or pinic acid. This suggests that pinic acid cannot be a key species in the first steps in nucleation, but the favorable interactions between sulfuric acid and pinic acid imply that pinic acid can contribute to the subsequent growth of...

  16. Bacterial diversity in the foreland of the Tianshan No. 1 glacier, China

    International Nuclear Information System (INIS)

    There is compelling evidence that glaciers are retreating in many mountainous areas of the world due to global warming. With this glacier retreat, new habitats are being exposed that are colonized by microorganisms whose diversity and function are less well studied. Here, we characterized bacterial diversity along the chronosequences of the glacier No. 1 foreland that follows glacier retreat. An average of 10 000 sequences was obtained from each sample by 454 pyrosequencing. Using non-parametric and rarefaction estimated analysis, we found bacterial phylotype richness was high. The bacterial species turnover rate was especially high between sites exposed for 6 and 10 yr. Pyrosequencing showed tremendous bacterial diversity, among which the Acidobacteria, Actinobacteria, Bacteroidetes and Proteobacteria were found to be present at larger numbers at the study area. Meanwhile, the proportion of Bacteroidetes and Proteobacteria decreased and the proportion of Acidobacteria increased along the chronosequences. Some known functional bacterial genera were also detected and the sulfur- and sulfate-reducing bacteria were present in a lower proportion of sequences. These findings suggest that high-throughput pyrosequencing can comprehensively detect bacteria in the foreland, including rare groups, and give a deeper understanding of the bacterial community structure and variation along the chronosequences. (letter)

  17. Sulfur metabolism in the extreme acidophile Acidithiobacillus caldus

    Directory of Open Access Journals (Sweden)

    Stefanie eMangold

    2011-02-01

    Full Text Available Given the challenges to life at low pH, an analysis of inorganic sulfur compound oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of inorganic sulfur compounds. It has been implicated in the production of environmentally damaging acidic solutions as well as participating in industrial bioleaching operations where it forms part of microbial consortia used for the recovery of metal ions. Based upon the recently published A. caldus type strain genome sequence, a bioinformatic reconstruction of elemental sulfur and inorganic sulfur compound metabolism predicted genes included: sulfide quinone reductase (sqr, tetrathionate hydrolase (tth, two sox gene clusters potentially involved in thiosulfate oxidation (soxABXYZ, sulfur oxygenase reductase (sor, and various electron transport components. RNA transcript profiles by semi-quantitative reverse transcription PCR suggested up-regulation of sox genes in the presence of tetrathionate. Extensive gel based proteomic comparisons of total soluble and membrane enriched protein fractions during growth on elemental sulfur and tetrathionate identified differential protein levels from the two Sox clusters as well as several chaperone and stress proteins up-regulated in the presence of elemental sulfur. Proteomics results also suggested the involvement of heterodisulfide reductase (HdrABC in A. caldus inorganic sulfur compound metabolism. A putative new function of Hdr in acidophiles is discussed. Additional proteomic analysis evaluated protein expression differences between cells grown attached to solid, elemental sulfur versus planktonic cells. This study has provided insights into sulfur metabolism of this acidophilic chemolithotroph and gene expression during attachment to solid elemental sulfur.

  18. World sulfur production: Petroleum derived as of January 1, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    Data are presented on world sulfur production by company within each country. The table lists the source of the sulfur (refinery gases, natural gas, acid gas, sour gas, oil sands, associated gas, or resid asphalt), the type of process used to recovery the sulfur, plant design capacity, and production. Processes include Claus, chlorination, Scot, Sulfinol, Sulfreen, modified Claus, bed absorption, MDEA-LoCat, Selectox, Parsons, SNEA, Comprimo, Uhde, Stretford, and Wellman-Lord.

  19. Accidental Sulfur Poisoning in a Group of Holstein Heifers

    OpenAIRE

    Gunn, Moira F.; Baird, John D.; Wilkie, Judith S. Nimmo

    1987-01-01

    Fourteen animals died or were euthanized after toxic levels of elemental sulfur were accidentally fed to a group of 120 Holstein heifers. Dehydration, rumen stasis, tachycardia, and diarrhea were seen along with metabolic acidosis, hypokalemia, and hypochloremia. The majority of deaths occurred from 3 to 10 days after the sulfur was fed to the heifers. Postmortem examination showed rumenitis, acute alveolitis, and renal tubular necrosis. The toxicity of ingested sulfur was attributed to the c...

  20. Plant sulfur nutrition: From Sachs to Big Data

    OpenAIRE

    Kopriva, Stanislav

    2015-01-01

    Together with water and carbon dioxide plants require 14 essential mineral nutrients to finish their life cycle. The research in plant nutrition can be traced back to Julius Sachs, who was the first to experimentally prove the essentiality of mineral nutrients for plants. Among those elements Sachs showed to be essential is sulfur. Plant sulfur nutrition has been not as extensively studied as the nutrition of nitrogen and phosphate, probably because sulfur was not limiting for agriculture. Ho...

  1. Sulfur in human nutrition and applications in medicine.

    Science.gov (United States)

    Parcell, Stephen

    2002-02-01

    Because the role of elemental sulfur in human nutrition has not been studied extensively, it is the purpose of this article to emphasize the importance of this element in humans and discuss the therapeutic applications of sulfur compounds in medicine. Sulfur is the sixth most abundant macromineral in breast milk and the third most abundant mineral based on percentage of total body weight. The sulfur-containing amino acids (SAAs) are methionine, cysteine, cystine, homocysteine, homocystine, and taurine. Dietary SAA analysis and protein supplementation may be indicated for vegan athletes, children, or patients with HIV, because of an increased risk for SAA deficiency in these groups. Methylsulfonylmethane (MSM), a volatile component in the sulfur cycle, is another source of sulfur found in the human diet. Increases in serum sulfate may explain some of the therapeutic effects of MSM, DMSO, and glucosamine sulfate. Organic sulfur, as SAAs, can be used to increase synthesis of S-adenosylmethionine (SAMe), glutathione (GSH), taurine, and N-acetylcysteine (NAC). MSM may be effective for the treatment of allergy, pain syndromes, athletic injuries, and bladder disorders. Other sulfur compounds such as SAMe, dimethylsulfoxide (DMSO), taurine, glucosamine or chondroitin sulfate, and reduced glutathione may also have clinical applications in the treatment of a number of conditions such as depression, fibromyalgia, arthritis, interstitial cystitis, athletic injuries, congestive heart failure, diabetes, cancer, and AIDS. Dosages, mechanisms of action, and rationales for use are discussed. The low toxicological profiles of these sulfur compounds, combined with promising therapeutic effects, warrant continued human clinical trails. PMID:11896744

  2. Current toxicological information as the basis for sulfur oxide standards.

    OpenAIRE

    Mehlman, M A

    1983-01-01

    The ambient air quality standard established in 1973 is 0.03 ppm annual average for sulfur dioxide and 0.075 mg/m3 for particulates. It is now generally believed that the toxicity of sulfur oxides in ambient air is significantly influenced by the coincident presence of particulates. Inhalation of 1 ppm of sulfur dioxide for 2 hr may produce alterations in pulmonary ventilatory function, both in normal and asthmatic subjects. Effects obtained at 0.5 ppm of sulfur dioxide are controversial and ...

  3. Bacterial chemoautotrophy in coastal sediments

    NARCIS (Netherlands)

    Vasquez Cardenas, D.

    2016-01-01

    Chemoautotrophy is the process by which micro-organisms fix CO2 by obtainingenergy from the oxidation of reduced compounds such sulfide and ammonium (e.g.sulfur oxidation and nitrification). This metabolism is widespread in nature and isvastly studied in extreme environments such as hydrothermal ven

  4. The triple point of sulfur hexafluoride

    Science.gov (United States)

    Rourke, P. M. C.

    2016-04-01

    A cryogenic fixed point cell has been filled with high purity (99.999%) sulfur hexafluoride (SF6) and measured in an adiabatic closed-cycle cryostat system. Temperature measurements of the SF6 melting curve were performed using a capsule-type standard platinum resistance thermometer (CSPRT) calibrated over the International Temperature Scale of 1990 (ITS-90) subrange from the triple point of equilibrium hydrogen to the triple point of water. The measured temperatures were corrected by 0.37 mK for the effects of thermometer self-heating, and the liquidus-point temperature estimated by extrapolation to melted fraction F  =  1 of a simple linear regression versus melted fraction F in the range F  =  0.53 to 0.84. Based on this measurement, the temperature of the triple point of sulfur hexafluoride is shown to be 223.555 23(49) K (k  =  1) on the ITS-90. This value is in excellent agreement with the best prior measurements reported in the literature, but with considerably smaller uncertainty. An analysis of the detailed uncertainty budget of this measurement suggests that if the triple point of sulfur hexafluoride were to be included as a defining fixed point of the next revision of the International Temperature Scale, it could do so with a total realization uncertainty of approximately 0.43 mK, slightly larger than the realization uncertainties of the defining fixed points of the ITS-90. Since the combined standard uncertainty of this SF6 triple point temperature determination is dominated by chemical impurity effects, further research exploring gas purification techniques and the influence of specific impurity species on the SF6 triple point temperature may bring the realization uncertainty of SF6 as a fixed point material into the range of the defining fixed points of the ITS-90.

  5. Bioinspired catalysis metal-sulfur complexes

    CERN Document Server

    Weigand, Wolfgang

    2014-01-01

    The growing interest in green chemistry calls for new, efficient and cheap catalysts. Living organisms contain a wide range of remarkably powerful enzymes, which can be imitated by chemists in the search for new catalysts. In bioinspired catalysis, chemists use the basic principles of biological enzymes when creating new catalyst analogues. In this book, an international group of experts cover the topic from theoretical aspects to applications by including a wide variety of examples of different systems. This valuable overview of bioinspired metal-sulfur catalysis is a must-have for all sci

  6. Modelling of Sulfuric Acid Nanoparticles Growth

    Czech Academy of Sciences Publication Activity Database

    Škrabalová, Lenka; Brus, D.; Antilla, T.; Ždímal, Vladimír; Lihavainen, H.

    Praha: Czech Aerosol Society, 2013 - (Zíková, N.), s. 95-100 ISBN 978-80-86186-52-8. [Výroční konference České aerosolové společnosti /14./. Nový Smokovec, High Tatras (SK), 23.10.2013-25.10.2013] R&D Projects: GA AV ČR IAA200760905 Grant ostatní: AFCE(FI) 1118615 Institutional support: RVO:67985858 Keywords : sulfuric acid * nanoparticles * particle growth Subject RIV: BJ - Thermodynamics

  7. Advanced Byproduct Recovery: Direct Catalytic Reduction of Sulfur Dioxide to Elemental Sulfur.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    More than 170 wet scrubber systems applied, to 72,000 MW of U.S., coal-fired, utility boilers are in operation or under construction. In these systems, the sulfur dioxide removed from the boiler flue gas is permanently bound to a sorbent material, such as lime or limestone. The sulfated sorbent must be disposed of as a waste product or, in some cases, sold as a byproduct (e.g. gypsum). Due to the abundance and low cost of naturally occurring gypsum, and the costs associated with producing an industrial quality product, less than 7% of these scrubbers are configured to produce usable gypsum (and only 1% of all units actually sell the byproduct). The disposal of solid waste from each of these scrubbers requires a landfill area of approximately 200 to 400 acres. In the U.S., a total of 19 million tons of disposable FGD byproduct are produced, transported and disposed of in landfills annually. The use of regenerable sorbent technologies has the potential to reduce or eliminate solid waste production, transportation and disposal. In a regenerable sorbent system, the sulfur dioxide in the boiler flue gas is removed by the sorbent in an adsorber. The S0{sub 2}s subsequently released, in higher concentration, in a regenerator. All regenerable systems produce an off-gas stream from the regenerator that must be processed further in order to obtain a salable byproduct, such as elemental sulfur, sulfuric acid or liquid S0{sub 2}.

  8. 40 CFR 52.1881 - Control strategy: Sulfur oxides (sulfur dioxide).

    Science.gov (United States)

    2010-07-01

    ... 40 CFR 52.1870: (i) Rules as effective in Ohio on December 28, 1979: OAC 3745-18-04(A), (B), (C), (D... citations affecting § 52.1881, see the List of CFR Sections Affected, which appears in the Finding Aids... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Sulfur oxides...

  9. SYNTHESIS OF SULFUR-BASED WATER TREATMENT AGENT FROM SULFUR DIOXIDE WASTE STREAMS

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Brown; Maohong Fan

    2001-12-01

    We propose a process that uses sulfur dioxide from coal combustion as a raw material to synthesize polymeric ferric sulfate (PFS), a water treatment agent. The process uses sodium chlorate as an oxidant and ferrous sulfate as an absorbent. The major chemical mechanisms in this reaction system include oxidation, hydrolysis, and polymerization. Oxidation determines sulfur conversion efficiency while hydrolysis and polymerization control the quality of product. Many factors, including SO{sub 2} inlet concentration, flow rate of simulated flue gas, reaction temperature, addition rate of oxidant and stirring rate, may affect the efficiencies of SO{sub 2} removal. Currently, the effects of SO{sub 2} inlet concentration, the flow rate of simulated flue gas and addition rate of flue gas on removal efficiencies of SO{sub 2}, are being investigated. Experiments shown in this report have demonstrated that the conversion efficiencies of sulfur dioxide with ferrous sulfate as an absorbent are in the range of 60-80% under the adopted process conditions. However, the conversion efficiency of sulfur dioxide may be improved by optimizing reaction conditions to be investigated. Partial quality indices of the synthesized products, including Fe{sup 2+} concentration and total iron concentration, have been evaluated.

  10. Thioautotrophic bacterial endosymbionts are degraded by enzymatic digestion during starvation: Case study of two lucinids Codakia orbicularis and C. orbiculata.

    Science.gov (United States)

    König, Sten; Le Guyader, Hervé; Gros, Olivier

    2015-02-01

    The Caribbean bivalves Codakia orbicularis (Linné, 1758) and C. orbiculata (Montagu, 1808) live in seagrass beds of Thalassia testudinum and harbor intracellular sulfur-oxidizing gamma-proteobacteria. These bacterial symbionts fix CO2 via the Calvin Benson cycle and provide organic compounds to the bivalve. During experimentally induced starvation, no reduced sulfur compounds and no organic particle food are available; the symbionts could be considered as the sole nutrient source of the host bivalve. A previous study has shown that the intracellular bacterial population decreased considerably during starvation and that bacterial endosymbionts were not released by the bivalves. In this study, the activity of two lysosomal marker enzymes (acid phosphatase and arylsulfatase) was detected using cytochemical experiments coupled with energy-dispersive X-ray transmission electron microscopy during sulfide and organic particle starvation. The degradation of bacterial endosymbionts began after 2 weeks of starvation in C. orbiculata and after 3 weeks in C. orbicularis. Degradation processes seem to be continuous over several months and could be responsible for the disappearance of the bacterial endosymbionts within the gills during starvation. These data suggest that the host use symbionts as a nutrient source to survive a hunger crisis. The carbon transfer from the symbionts to the host could be flexible and could consist in transfer of organic matter, "milking," under normal feeding conditions and digestion of the symbionts under starved conditions. PMID:25429862

  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. 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.

  13. The rare bacterial biosphere.

    Science.gov (United States)

    Pedrós-Alió, Carlos

    2012-01-01

    All communities are dominated by a few species that account for most of the biomass and carbon cycling. On the other hand, a large number of species are represented by only a few individuals. In the case of bacteria, these rare species were until recently invisible. Owing to their low numbers, conventional molecular techniques could not retrieve them. Isolation in pure culture was the only way to identify some of them, but current culturing techniques are unable to isolate most of the bacteria in nature. The recent development of fast and cheap high-throughput sequencing has begun to allow access to the rare species. In the case of bacteria, the exploration of this rare biosphere has several points of interest. First, it will eventually produce a reasonable estimate of the total number of bacterial taxa in the oceans; right now, we do not even know the right order of magnitude. Second, it will answer the question of whether "everything is everywhere." Third, it will require hypothesizing and testing the ecological mechanisms that allow subsistence of many species in low numbers. And fourth, it will open an avenue of research into the immense reserve of genes with potential applications hidden in the rare biosphere. PMID:22457983

  14. Transport Powered by Bacterial Turbulence

    Science.gov (United States)

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-04-01

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations.

  15. Transport powered by bacterial turbulence.

    Science.gov (United States)

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S

    2014-04-18

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations. PMID:24785075

  16. Sustainable Sulfur-rich Copolymer/Graphene Composite as Lithium-Sulfur Battery Cathode with Excellent Electrochemical Performance

    OpenAIRE

    Arnab Ghosh; Swapnil Shukla; Gaganpreet Singh Khosla; Bimlesh Lochab; Sagar Mitra

    2016-01-01

    A sulfur-rich copolymer, poly(S-r-C-a) has been synthesized via a sustainable route, showing the utility of two major industrial wastes- elemental sulfur (petroleum waste) and cardanol (agro waste), to explore its potential as cathode material for Li-S batteries. The sulfur-rich copolymer exhibited a reduction in the active material dissolution into the electrolyte and a low self-discharge rate behavior during the rest time compared to an elemental sulfur cathode, indicating the chemical conf...

  17. Chapter 3. Sulfuric acid decomposition of borosilicate ores. 3.1. Decomposition of borosilicate ores by sulfuric acid

    International Nuclear Information System (INIS)

    Present article is devoted to decomposition of borosilicate ores by sulfuric acid. The sulfuric acid decomposition of borate ores of Ak-Arkhar Deposit was studied. The possibility of multipurpose utilization of borate ores was shown. The influence of process duration on the rate of oxides (B2O3, Fe2O3 and Al2O3) extraction was studied as well. In order to reach the complete decomposition of oxides from danburite ore the dependence of rate of oxides decomposition on concentration of sulfuric acid was studied. The optimal conditions of sulfuric acid decomposition of danburite ores were proposed.

  18. Enhanced electrochemical performance of a crosslinked polyaniline-coated graphene oxide-sulfur composite for rechargeable lithium-sulfur batteries

    Science.gov (United States)

    Moon, San; Jung, Young Hwa; Kim, Do Kyung

    2015-10-01

    Due to the extraordinarily high theoretical capacity of sulfur (1675 mAh g-1), the lithium-sulfur (Li-S) battery has been considered a promising candidate for future high-energy battery applications. Li-S batteries, however, have suffered from limited cycle lives, mainly due to the formation of soluble polysulfides, which prevent the practical application of this attractive technology. The encapsulation of sulfur with various conductive materials has addressed this issue to some extent. Nevertheless, most approaches still present partial encapsulation of sulfur and moreover require a large quantity of conductive material (typically, >30 wt%), making the use of sulfur less desirable from the viewpoint of capacity. Here, we address these chronic issues of Li-S cells by developing a graphene oxide-sulfur composite with a thin crosslinked polyaniline (PANI) layer. Graphene oxide nanosheets with large surface area, high conductivity and a uniform conductive PANI layer, which are synthesized by a layer-by-layer method, have a synergetic interaction with a large portion of the sulfur in the active material. Furthermore, a simple crosslinking process efficiently prevents polysulfide dissolution, resulting in unprecedented electrochemical performance, even with a high sulfur content (∼75%): a high capacity retention of ∼80% is observed, in addition to 97.53% of the average Coulombic efficiency being retained after 500 cycles. The performance we demonstrate represents an advance in the field of lithium-sulfur batteries for applications such as power tools.

  19. Three-dimensional porous carbon composites containing high sulfur nanoparticle content for high-performance lithium–sulfur batteries

    Science.gov (United States)

    Li, Guoxing; Sun, Jinhua; Hou, Wenpeng; Jiang, Shidong; Huang, Yong; Geng, Jianxin

    2016-01-01

    Sulfur is a promising cathode material for lithium–sulfur batteries because of its high theoretical capacity (1,675 mA h g−1); however, its low electrical conductivity and the instability of sulfur-based electrodes limit its practical application. Here we report a facile in situ method for preparing three-dimensional porous graphitic carbon composites containing sulfur nanoparticles (3D S@PGC). With this strategy, the sulfur content of the composites can be tuned to a high level (up to 90 wt%). Because of the high sulfur content, the nanoscale distribution of the sulfur particles, and the covalent bonding between the sulfur and the PGC, the developed 3D S@PGC cathodes exhibit excellent performance, with a high sulfur utilization, high specific capacity (1,382, 1,242 and 1,115 mA h g−1 at 0.5, 1 and 2 C, respectively), long cycling life (small capacity decay of 0.039% per cycle over 1,000 cycles at 2 C) and excellent rate capability at a high charge/discharge current. PMID:26830732

  20. Aspergillus flavus Conidia-derived Carbon/Sulfur Composite as a Cathode Material for High Performance Lithium–Sulfur Battery

    OpenAIRE

    Maowen Xu; Min Jia; Cuiping Mao; Sangui Liu; Shujuan Bao; Jian Jiang; Yang Liu; Zhisong Lu

    2016-01-01

    A novel approach was developed to prepare porous carbon materials with an extremely high surface area of 2459.6 m2g−1 by using Aspergillus flavus conidia as precursors. The porous carbon serves as a superior cathode material to anchor sulfur due to its uniform and tortuous morphology, enabling high capacity and good cycle lifetime in lithium sulfur-batteries. Under a current rate of 0.2 C, the carbon-sulfur composites with 56.7 wt% sulfur loading deliver an initial capacity of 1625 mAh g−1, w...

  1. Extreme variation of sulfur isotopic compositions in pyrite from the Qiuling sediment-hosted gold deposit, West Qinling orogen, central China: an in situ SIMS study with implications for the source of sulfur

    Science.gov (United States)

    Chen, Lei; Li, Xian-hua; Li, Jian-wei; Hofstra, Albert H.; Liu, Yu; Koenig, Alan E.

    2015-08-01

    High spatial resolution textural (scanning electron microscope (SEM)), chemical (electron microprobe (EMP)) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)), and sulfur isotopic (secondary ion mass spectrometry (SIMS)) analyses of pyrite from the Qiuling sediment-hosted gold deposit (232 ± 4 Ma) in the West Qinling orogen, central China were conducted to distinguish pyrite types and gain insights into the source and evolution of sulfur in hydrothermal fluids. The results reveal an enormous variation (-27.1 to +69.6 ‰) in sulfur isotopic composition of pyrite deposited during three paragenetic stages. Pre-ore framboidal pyrite, which is characterized by low concentrations of As, Au, Cu, Co, and Ni, has negative δ34S values of -27.1 to -7.6 ‰ that are interpreted in terms of bacterial reduction of marine sulfate during sedimentation and diagenesis of the Paleozoic carbonate and clastic sequences, the predominant lithologies in the deposit area, and the most important hosts of many sediment-hosted gold deposits throughout the West Qinling orogen. The ore-stage hydrothermal pyrite contains high concentrations of Au, As, Cu, Sb, Tl, and Bi and has a relatively narrow range of positive δ34S values ranging from +8.1 to +15.2 ‰. The sulfur isotope data are comparable to those of ore pyrite from many Triassic orogenic gold deposits and Paleozoic sedimentary exhalative (SEDEX) Pb-Zn deposits in the West Qinling orogen, both being hosted mainly in the Devonian sequence. This similarity indicates that sulfur, responsible for the auriferous pyrite at Qiuling, was largely derived from the metamorphic devolatization of Paleozoic marine sedimentary rocks. Post-ore-stage pyrite, which is significantly enriched in Co and Ni but depleted in Au and As, has unusually high δ34S values ranging from +37.4 to +69.6 ‰, that are interpreted to result from thermochemical reduction of evaporite sulfates in underlying Cambrian sedimentary rocks with very

  2. Aspects of the life cycles of chemosynthetic bacterial symbionts associated with bivalves from deep-sea chemosynthesis-based ecosystems

    OpenAIRE

    Szafranski, Kamil,

    2014-01-01

    Metazoans colonizing deep-sea reducing habitats often employ chemosymbiotic bacterial associations. Hosts become dependent upon their sulfur-oxidizing and/or methanotrophic symbionts, which provide organic carbon compounds. Various larval dispersal strategies have evolved in the hosts, ensuring the colonization of new sites. The continuity of the symbiotic association is maintained by symbiont transmission. Symbionts may pass directly to the host’s progeny via gametes (vertical transmission) ...

  3. Oxidation of Elemental Sulfur in Selected Soils of China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An incubation experiment was carried out in laboratory to study the effect of temperature, moisture,phosphorus, organic matter, cropping and previous elemental sulfur application on elemental sulfur oxidation in four selected soils, fluvo-aquic soil, black soil, yellow-brown soil and red soil. In all the soils tested, sulfur oxidation rate was influenced by temperature and the temperature coefficient (Q10) values at the range from 10to 30 ℃ were 4.41, 4.05, 6.19 and 3.71 for the four soils, respectively. The rate of sulfur oxidation was parabolically related to soil water content. The optimum moisture content for the maximum oxidation rate was different among soils. Phosphorus increased the oxidation rate of elemental sulfur by 57.7%, 33.1%, 21.7% and 26.4% for the above four soils, respectively, compared with the control (no phosphorus applied). Organic material of corn straw which was ground and passed through a 0.5-mm sieve also increased the oxidation rate of elemental sulfur in the four soils by 59.8%, 7.8%, 39.2% and 540.4%, respectively. Elemental sulfur which was applied previously to soils significantly enhanced the oxidation of elemental sulfur subsequently added and increased sulfur-oxidizing populations such as autotrophic elemental sulfur oxidizers with pH optimum 6.8, autotrophic thiosulfate oxidizers with pH optimum 6.8, heterotrophic thiosulfate oxidizers and heterotrophic sulfate producers. Cropping had little effect on lemental sulfur-oxidizing potentiality of soils.

  4. Reduction of Sulfur Dioxide on Carbons Catalyzed by Salts

    Directory of Open Access Journals (Sweden)

    Wido Schreiner

    2005-01-01

    Full Text Available Abstract. The reduction of SO2 on different carbons in the presence of the nitrates and sulfides of sodium, potassium and calcium and potassium polysulfides was studied. The presence of salts increased the initial rate 2-5 fold for all of them and did not change the product distribution. The catalysis was not determined by the cation and there was no difference in the catalytic reactivity between nitrates and sulfides. The sulfur content of the activated carbon increased during the reaction on account of the stable reactive intermediates in the reduction of SO2. In the presence of NaNO3 or Na2S, the amount of sulfur incorporated was in the molar ratio Na:S = 3 ± 0.3, and the XPS spectra of the residual carbon showed an increase of ca. 9% of the non-oxidized form of sulfur in the intermediates. In the absence of salt, it is proposed that after the adsorption of SO2 on the carbon, a 1,3,2-dioxathiolane or 1,2-oxathietene 2-oxide are formed and that decompose to produce CO2 and atomic sulfur. The non-oxidized sulfur intermediate would be an episulfide 3, formed from the reaction of the atomic sulfur with the nearest double bond and followed by consecutive reactions of insertion of atomic sulfur to form a trisulfide. Extrusion of S2 from the trisulfide would regenerate the episulfide, establishing a sulfidedisulfide-trisulfide equilibrium that worked as a capture-release cycle of sulfur. In the presence of salt, the results are consistent with the assumption that the episulfide 3 reacts with the corresponding sulfide anion to form a disulfide anion, which upon reaction with atomic sulfur forms a trisulfide anion that decomposes releasing diatomic sulfur S2, transporting the sulfur and generating a thiolate that is part of the catalytic cycle.

  5. Sulfur chemistry in a copper smelter plume

    Energy Technology Data Exchange (ETDEWEB)

    Eatough, D.J.; Christensen, J.J.; Hill, M.W.; Major, T.D.; Mangelson, N.F.; Post, M.E.; Ryder, J.F.; Hansen, L.D.

    Sulfur transformation chemistry was studied in the plume of the Utah smelter of Kennecott Copper Corporation from April to October 1977. Samples were taken at up to four locations from 4 to 60 km from the stacks. Data collected at each station included: SO/sub 2/ concentration, low-volume collected total particulate matter, high-volume collected size fractionated particulate matter, wind velocity and direction, temperature, and relative humidity.The SO/sub 2/(g)-sulfate conversion process in the plume is described by a mechanism which is first order in SO/sub 2/(g). Equations are derived describing sulfur chemistry when both S(IV) and sulfate formation occur in a plume. The formation of sulfate results primarily in the formation of <0.5 ..mu..m particulates. The formation process is not correlated with plume expansion, particulate acidity, metal content, or S(IV) species. Due to meteorological restrictions on sampling, data were collected only during periods of maximum insolation. The formation of sulfate from SO/sub 2/(g) in the plume during periods of high insolation is temperature dependent with an apparent activation energy of 16.6 +/- 1.4 kcal mol/sup -1/ and k/sub 1/ value of 0.039 h/sup -1/ at 25/sup 0/C.

  6. Magnetic effects in sulfur-decorated graphene

    Science.gov (United States)

    Hwang, Choongyu; Cybart, Shane A.; Shin, S. J.; Kim, Sooran; Kim, Kyoo; Rappoport, T. G.; Wu, S. M.; Jozwiak, C.; Fedorov, A. V.; Mo, S.-K.; Lee, D.-H.; Min, B. I.; Haller, E. E.; Dynes, R. C.; Castro Neto, A. H.; Lanzara, Alessandra

    2016-02-01

    The interaction between two different materials can present novel phenomena that are quite different from the physical properties observed when each material stands alone. Strong electronic correlations, such as magnetism and superconductivity, can be produced as the result of enhanced Coulomb interactions between electrons. Two-dimensional materials are powerful candidates to search for the novel phenomena because of the easiness of arranging them and modifying their properties accordingly. In this work, we report magnetic effects in graphene, a prototypical non-magnetic two-dimensional semi-metal, in the proximity with sulfur, a diamagnetic insulator. In contrast to the well-defined metallic behaviour of clean graphene, an energy gap develops at the Fermi energy for the graphene/sulfur compound with decreasing temperature. This is accompanied by a steep increase of the resistance, a sign change of the slope in the magneto-resistance between high and low fields, and magnetic hysteresis. A possible origin of the observed electronic and magnetic responses is discussed in terms of the onset of low-temperature magnetic ordering. These results provide intriguing insights on the search for novel quantum phases in graphene-based compounds.

  7. Thermo Scientific Sulfur Dioxide Analyzer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Springston, S. R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-03-01

    The Sulfur Dioxide Analyzer measures sulfur dioxide based on absorbance of UV light at one wavelength by SO2 molecules which then decay to a lower energy state by emitting UV light at a longer wavelength. Specifically, SO2 + hυ1 →SO2 *→SO2 + hυ2 The emitted light is proportional to the concentration of SO2 in the optical cell. External communication with the analyzer is available through an Ethernet port configured through the instrument network of the AOS systems. The Model 43i-TLE is part of the i-series of Thermo Scientific instruments. The i-series instruments are designed to interface with external computers through the proprietary Thermo Scientific iPort Software. However, this software is somewhat cumbersome and inflexible. BNL has written an interface program in National Instruments LabView that both controls the Model 43i-TLE Analyzer AND queries the unit for all measurement and housekeeping data. The LabView vi (the software program written by BNL) ingests all raw data from the instrument and outputs raw data files in a uniform data format similar to other instruments in the AOS and described more fully in Section 6.0 below.

  8. Sulfur Isotopic Fractionation of Carbonyl Sulfide during Degradation by Soil Bacteria.

    Science.gov (United States)

    Kamezaki, Kazuki; Hattori, Shohei; Ogawa, Takahiro; Toyoda, Sakae; Kato, Hiromi; Katayama, Yoko; Yoshida, Naohiro

    2016-04-01

    We performed laboratory incubation experiments on the degradation of gaseous phase carbonyl sulfide (OCS) by soil bacteria to determine its sulfur isotopic fractionation constants ((34)ε). Incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia, and Cupriavidus isolated from natural soil environments. The (34)ε values determined were -3.67 ± 0.33‰, -3.99 ± 0.19‰, -3.57 ± 0.22‰, and -3.56 ± 0.23‰ for Mycobacterium spp. strains THI401, THI402, THI404, and THI405; -3.74 ± 0.29‰ for Williamsia sp. strain THI410; and -2.09 ± 0.07‰ and -2.38 ± 0.35‰ for Cupriavidus spp. strains THI414 and THI415. Although OCS degradation rates divided by cell numbers (cell-specific activity) were different among strains of the same genus, the (34)ε values for same genus showed no significant differences. Even though the numbers of bacterial species examined were limited, our results suggest that (34)ε values for OCS bacterial degradation depend not on cell-specific activities, but on genus-level biological differences, suggesting that (34)ε values are dependent on enzymatic and/or membrane properties. Taking our (34)ε values as representative for bacterial OCS degradation, the expected atmospheric changes in δ(34)S values of OCS range from 0.5‰ to 0.9‰, based on previously reported decreases in OCS concentrations at Mt. Fuji, Japan. Consequently, tropospheric observation of δ(34)S values for OCS coupled with (34)ε values for OCS bacterial degradation can potentially be used to investigate soil as an OCS sink. PMID:26967120

  9. Bacterial flora of sturgeon fingerling

    International Nuclear Information System (INIS)

    The study on microbial populations is a suitable tool to understand and apply control methods to improve the sanitary level of production in fish breeding and rearing centers, ensure health of sturgeon fingerlings at the time of their release into the rivers and also in the conversation and restoration of these valuable stocks in the Caspian Sea, Iran. A laboratory research based on Austin methods (Austin, B., Austin, D.A. 1993) was conducted for bacterial study on 3 sturgeon species naming A. persicus, A. stellatus and A. nudiventris during different growth stages. Bacterial flora of Acinetobacter, Moraxella, Aeromonas, Vibrio, Edwardsiella, Staphylococcus, Proteus, Yersinia, Pseudomonas and Plesiomonas were determined. The factors which may induce changes in bacterial populations during different stages of fife are the followings: quality of water in rearing ponds, different conditions for growth stages, suitable time for colonization of bacterial flora in rearing pond, water temperature increase in fingerlings size and feeding condition. (author)

  10. 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

  11. Influence of Sulfur Fertilization on the Antioxidant Activities of Onion Juices Prepared by Thermal Treatment.

    Science.gov (United States)

    Koh, Eunmi; Surh, Jeonghee

    2016-06-01

    Two onions (Sulfur-1 and Sulfur-4) cultivated with different sulfur applications were thermally processed to elucidate the effects of heat treatment on browning index and antioxidant activity. Sulfur-4 onion had higher sulfur content compared with the Sulfur-1 onion. After thermal processing, browning intensity was different between the two onions juices, with lower values observed for Sulfur-4 onion juice. This suggests that sulfur inhibits the Maillard browning reaction. The total reducing capacity of the juices increased at higher thermal processing temperatures; however, it was also lower in the Sulfur-4 onion juice. This suggests that the heat treatment of onions enhanced their antioxidant activity, but the effect was offset in the Sulfur-4 onion juice presumably due to higher sulfur content. This study indicates that sulfur, a core element for the functionality of onions, can decrease the antioxidant activity of thermally processed onions because of its potential as a Maillard reaction inhibitor. PMID:27390734

  12. Influence of Sulfur Fertilization on the Antioxidant Activities of Onion Juices Prepared by Thermal Treatment

    Science.gov (United States)

    Koh, Eunmi; Surh, Jeonghee

    2016-01-01

    Two onions (Sulfur-1 and Sulfur-4) cultivated with different sulfur applications were thermally processed to elucidate the effects of heat treatment on browning index and antioxidant activity. Sulfur-4 onion had higher sulfur content compared with the Sulfur-1 onion. After thermal processing, browning intensity was different between the two onions juices, with lower values observed for Sulfur-4 onion juice. This suggests that sulfur inhibits the Maillard browning reaction. The total reducing capacity of the juices increased at higher thermal processing temperatures; however, it was also lower in the Sulfur-4 onion juice. This suggests that the heat treatment of onions enhanced their antioxidant activity, but the effect was offset in the Sulfur-4 onion juice presumably due to higher sulfur content. This study indicates that sulfur, a core element for the functionality of onions, can decrease the antioxidant activity of thermally processed onions because of its potential as a Maillard reaction inhibitor. PMID:27390734

  13. Accelerated evolutionary rate in sulfur-oxidizing endosymbiotic bacteria associated with the mode of symbiont transmission.

    Science.gov (United States)

    Peek, A S; Vrijenhoek, R C; Gaut, B S

    1998-11-01

    The nearly neutral theory of molecular evolution predicts that the rate of nucleotide substitution should accelerate in small populations at sites under low selective constraint. We examined these predictions with respect to the relative population sizes for three bacterial life histories within chemolithoautotrophic sulfur-oxidizing bacteria: (1) free-living bacteria, (2) environmentally captured symbionts, and (3) maternally transmitted symbionts. Both relative rates of nucleotide substitution and relative ratios of loop, stem, and domain substitutions from 1,165 nt of the small-subunit 16S rDNA were consistent with expectations of the nearly neutral theory. Relative to free-living sulfur-oxidizing autotrophic bacteria, the maternally transmitted symbionts have faster substitution rates overall and also in low-constraint domains of 16S rDNA. Nucleotide substitition rates also differ between loop and stem positions. All of these findings are consistent with the predictions that these symbionts have relatively small effective population sizes. In contrast, the rates of nucleotide substitution in environmentally captured symbionts are slower, particularly in high-constraint domains, than in free-living bacteria. PMID:12572615

  14. The Bacterial Microflora of Fish

    OpenAIRE

    Austin, B.

    2002-01-01

    The results of numerous studies indicate that fish possess bacterial populations on or in their skin, gills, digestive tract, and light-emitting organs. In addition, the internal organs (kidney, liver, and spleen) of healthy fish may contain bacteria, but there is debate on whether or not muscle is actually sterile. The numbers and taxonomic composition of the bacterial populations often reflect those of the surrounding water. The role of the bacteria includes the ability to degrade complex m...

  15. Bacterial cellulose/boehmite composites

    Energy Technology Data Exchange (ETDEWEB)

    Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L. [Universidade Estadual Paulista Julio de Mesquita Filho. UNESP. Instituto de Quimica de Araraquara, SP (Brazil); Caiut, Jose Mauricio A. [Universidade de Sao Paulo. Departamento de Quimica - FFCLRP/USP, Ribeirao Preto, SP (Brazil)

    2011-07-01

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  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. 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

  18. 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)...

  19. Studies of Experimental Bacterial Translocation

    OpenAIRE

    Stenbäck, Anders

    2005-01-01

    One of the main obstacles to maintaining patients with short bowel syndrome on parenteral nutrition, or successfully transplanting these patients with a small bowel graft, is the many severe infections that occur. Evidence is accumulating that translocating bacteria from the patient’s bowel causes a significant part of these infections. In this thesis bacterial translocation is studied in a Thiry-Vella loop of defunctionalised small bowel in the rat. Bacterial translocation to the mesenteric ...

  20. Bacterial translocation: impact of probiotics

    OpenAIRE

    Jeppsson, Bengt; Mangell, Peter; Adawi, Diya; Molin, Göran

    2004-01-01

    There is a considerable amount of data in humans showing that patients who cannot take in nutrients enterally have more organ failure in the intensive care unit, a less favourable prognosis, and a higher frequency of septicaemia, in particular involving bacterial species from the intestinal tract. However, there is little evidence that this is connected with translocation of bacterial species in humans. Animal data more uniformly imply the existence of such a connection. The main focus of thi...

  1. Electrical spiking in bacterial biofilms

    OpenAIRE

    Masi, Elisa; Ciszak, Marzena; Santopolo, Luisa; Frascella, Arcangela; Giovannetti, Luciana; Marchi, Emmanuela; Viti, Carlo; Mancuso, Stefano

    2015-01-01

    In nature, biofilms are the most common form of bacterial growth. In biofilms, bacteria display coordinated behaviour to perform specific functions. Here, we investigated electrical signalling as a possible driver in biofilm sociobiology. Using a multi-electrode array system that enables high spatio-temporal resolution, we studied the electrical activity in two biofilm-forming strains and one non-biofilm-forming strain. The action potential rates monitored during biofilm-forming bacterial gro...

  2. Bacterial sex in dental plaque

    OpenAIRE

    Olsen, Ingar; Tribble, Gena D; Fiehn, Nils-Erik; Wang, Bing-Yan

    2013-01-01

    Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it a...

  3. Bacterial contamination of radiopharmaceutical preparations

    International Nuclear Information System (INIS)

    Examinations of the microflora of the air, personnel hands' skin, and surface of the equipment were performed in the Centre for Nuclear research, Libya. It is stated that bacterial contamination was maximal in winter and minimal in summer. The authors believe that human factor is the crucial in bacterial contamination. The microflora detected at the surfaces of equipment contains increased levels of radioresistent forms of bacteria. 8 refs.; 3 tabs

  4. 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)

  5. 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

  6. Sulfur in human nutrition - effects beyond protein synthesis

    OpenAIRE

    Schaafsma, Gertjan

    2008-01-01

    That sulfur is essential to humans is based on the requirement of S-animo acids for normal growth and maintenance of nitrogen balance and not on the optimization of metabolic proccesses involving the synthesis of non-protein sulphur containing compounds. This paper reviews the significance of sulfur in the diet with respect to its role beyond protein synthesis.

  7. Sulfur Flow Analysis for New Generation Steel Manufacturing Process

    Institute of Scientific and Technical Information of China (English)

    HU Chang-qing; ZHANG Chun-xia; HAN Xiao-wei; YIN Rui-yu

    2008-01-01

    Sulfur flow for new generation steel manufacturing process is analyzed by the method of material flow analysis,and measures for SO2 emission reduction are put forward as assessment and target intervention of the results.The results of sulfur flow analysis indicate that 90% of sulfur comes from fuels.Sulfur finally discharges from the steel manufacturing route in various steps,and the main point is BF and BOF slag desulfurization.In sintering process,the sulfur is removed by gasification,and sintering process is the main source of SO2 emission.The sulfur content of coke oven gas (COG) is an important factor affecting SO2 emission.Therefore,SO2 emission reduction should be started from the optimization and integration of steel manufacturing route,sulfur burden should be reduced through energy saving and consumption reduction,and the sulfur content of fuel should be controlled.At the same time,BF and BOF slag desulfurization should be optimized further and coke oven gas and sintering exhausted gas desulfurization should be adopted for SO2 emission reduction and reuse of resource,to achieve harmonic coordination of economic,social,and environmental effects for sustainable development.

  8. Sulfur content of gasoline and diesel fuels in northern China

    International Nuclear Information System (INIS)

    In order to investigate vehicle fuel quality in northern China, the sulfur content of fuels purchased from the market has been studied. 235 samples from urban areas and highway service stations were collected and tested with energy dispersive X-ray fluorescence spectrometry. 88% of the gasoline samples contained sulfur below 500 ppm, the limit then in effect, and 92.5% of the diesel fuel samples were below 2000 ppm, the required limit. China's Ministry of Environmental Protection recommend lower sulfur to assure that the vehicles using the fuels comply with the China III emission standards-those limits are 150 ppm sulfur for gasoline and 350 ppm for diesel fuel. The recommended limits were not often met: in Jinan, Shanghai, Changchun and Xi'an, 0%, 11%, 46% and 60% of the gasoline sampled were below 150 ppm sulfur. For samples from highway stations, only 14-58% of gasoline was under the 150 ppm sulfur and only 0-67% of diesel samples below 350 ppm in different regions. This mismatch, between fuel sulfur levels that would enable vehicle emission controls to operate effectively, and the actual fuel sulfur levels at service stations, results in unnecessarily high pollution from potentially cleaner vehicles.

  9. 40 CFR 52.2575 - Control strategy: Sulfur dioxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Sulfur dioxide. 52.2575 Section 52.2575 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... strategy: Sulfur dioxide. (a) Part D—Approval—With the exceptions set forth in this subpart,...

  10. 40 CFR 52.2525 - Control strategy: Sulfur dioxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Sulfur dioxide. 52.2525 Section 52.2525 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... strategy: Sulfur dioxide. (a) The provisions of § 51.112(a) are not met because the State did...

  11. 40 CFR 52.2033 - Control strategy: Sulfur oxides.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Sulfur oxides. 52.2033 Section 52.2033 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... strategy: Sulfur oxides. (a) The revision to the control strategy resulting from the modification to...

  12. 40 CFR 52.834 - Control strategy: Sulfur dioxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Sulfur dioxide. 52.834 Section 52.834 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Iowa § 52.834 Control strategy: Sulfur...

  13. Two-step rapid sulfur capture. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-04-01

    The primary goal of this program was to test the technical and economic feasibility of a novel dry sorbent injection process called the Two-Step Rapid Sulfur Capture process for several advanced coal utilization systems. The Two-Step Rapid Sulfur Capture process consists of limestone activation in a high temperature auxiliary burner for short times followed by sorbent quenching in a lower temperature sulfur containing coal combustion gas. The Two-Step Rapid Sulfur Capture process is based on the Non-Equilibrium Sulfur Capture process developed by the Energy Technology Office of Textron Defense Systems (ETO/TDS). Based on the Non-Equilibrium Sulfur Capture studies the range of conditions for optimum sorbent activation were thought to be: activation temperature > 2,200 K for activation times in the range of 10--30 ms. Therefore, the aim of the Two-Step process is to create a very active sorbent (under conditions similar to the bomb reactor) and complete the sulfur reaction under thermodynamically favorable conditions. A flow facility was designed and assembled to simulate the temperature, time, stoichiometry, and sulfur gas concentration prevalent in the advanced coal utilization systems such as gasifiers, fluidized bed combustors, mixed-metal oxide desulfurization systems, diesel engines, and gas turbines.

  14. Sulfur K-edge absorption spectroscopy on selected biological systems

    International Nuclear Information System (INIS)

    Sulfur is an essential element in organisms. In this thesis investigations of sulfur compounds in selected biological systems by XANES (X-ray Absorption Near Edge Structure) spectroscopy are reported. XANES spectroscopy at the sulfur K-edge provides an excellent tool to gain information about the local environments of sulfur atoms in intact biological samples - no extraction processes are required. Spatially resolved measurements using a Kirkpatrick-Baez mirror focusing system were carried out to investigate the infection of wheat leaves by rust fungi. The results give information about changes in the sulfur metabolism of the host induced by the parasite and about the extension of the infection into visibly uninfected plant tissue. Furthermore, XANES spectra of microbial mats from sulfidic caves were measured. These mats are dominated by microbial groups involved in cycling sulfur. Additionally, the influence of sulfate deprivation and H2S exposure on sulfur compounds in onion was investigated. To gain an insight into the thermal degradation of organic material the influence of roasting of sulfur compounds in coffee beans was studied. (orig.)

  15. Integrated boiler, superheater, and decomposer for sulfuric acid decomposition

    Science.gov (United States)

    Moore, Robert; Pickard, Paul S.; Parma, Jr., Edward J.; Vernon, Milton E.; Gelbard, Fred; Lenard, Roger X.

    2010-01-12

    A method and apparatus, constructed of ceramics and other corrosion resistant materials, for decomposing sulfuric acid into sulfur dioxide, oxygen and water using an integrated boiler, superheater, and decomposer unit comprising a bayonet-type, dual-tube, counter-flow heat exchanger with a catalytic insert and a central baffle to increase recuperation efficiency.

  16. THE EFFECT OF ATRAZINE ON DIMETHYL SULFUR IN MARINE PHYTOPLANKTON

    Science.gov (United States)

    It is anticipated that under stress, the cellular DMSP concentration should drop, as sulfur is transferred from the DMSP pool to DMS. Sulfur in the DMS pool will be transferred to the DMSO pool as radicals are scavenged. Enzyme activities such as DMSP lyase, which converts D...

  17. EMISSIONS OF SULFUR TRIOXIDE FROM COAL-FIRED POWER PLANTS

    Science.gov (United States)

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

  18. Extractive de-sulfurization and de-ashing of high sulfur coals by oxidation with ionic liquids

    International Nuclear Information System (INIS)

    Highlights: • Extractive de-sulfurization and de-ashing process for cleaning high sulfur coals. • The process removes inorganic as well as organic sulfur components from high sulfur coals. • The process has less risk to chemists and other surroundings. - Abstract: The environmental consequences of energy production from coals are well known, and are driving the development of desulfurization technologies. In this investigation, ionic liquids were examined for extractive desulfurization and de-ashing in industrially important high sulfur sub-bituminous Indian coals. The ionic liquids, namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (IL1) and 1-n-butyl 3-methylimidazolium chloride (IL2) were employed for desulfurization of a few Indian coal samples in presence of HCOOH/H2O2 and V2O5. Results show the maximum removal of 50.20% of the total sulfur, 48.00% of the organic sulfur, and 70.37 wt% of the ash in this process. The ionic liquids were recovered and subsequently used for further desulfurization. FT-IR spectra reveal the transformation of organic sulfur functionalities into the sulfoxides (S=O) and sulfones (-SO2) due to the oxidative reactions. The sulfate, pyrite and sulfides (aryls) signals in the near edge X-ray absorption fine structure (NEXAFS) of the oxidized coal samples showed sulfur transformation during the desulfurization process. The study demonstrates the removal of significant amount of inorganic as well as organic sulfur (aryls) components from the original high sulfur coal samples to make them cleaner

  19. Sulfur speciation and bioaccumulation in camphor tree leaves as atmospheric sulfur indicator analyzed by synchrotron radiation XRF and XANES

    Institute of Scientific and Technical Information of China (English)

    Jianrong Zeng; Guilin Zhang; Liangman Bao; Shilei Long; Mingguang Tan; Yan Li; Chenyan Ma

    2013-01-01

    Analyzing and understanding the effects of ambient pollution on plants is getting more and more attention as a topic of environmentalbiology.A method based on synchrotron radiation X-ray fluorescence and X-ray absorption near edge structure spectroscopy wasestablished to analyze the sulfur concentration and speciation in mature camphor tree leaves (CTLs),which were sampled from 5 localfields in Shanghai,China.Annual SO2 concentration,SO42-concentration in atmospheric particulate,SO42-and sulfur concentrationin soil were also analyzed to explore the relationship between ambient sulfur sources and the sulfur nutrient cycling in CTLs.Totalsulfur concentration in mature camphor tree leaves was 766-1704 mg/kg.The mainly detected sulfur states and their correspondingcompounds were +6 (sulfate,include inorganic sulfate and organic sulfate),+5.2 (sulfonate),+2.2 (suloxides),+0.6 (thiols andthiothers),+0.2 (organic sulfides).Total sulfur concentration was strongly correlated with sulfate proportion with a linear correlationcoefficient up to 0.977,which suggested that sulfur accumulated in CTLs as sulfate form.Reduced sulfur compounds (organic sulfides,thiols,thioethers,sulfoxide and sulfonate) assimilation was sufficed to meet the nutrient requirement for growth at a balanced levelaround 526 mg/kg.The sulfate accumulation mainly caused by atmospheric sulfur pollution such as SO2 and airborne sulfate particulateinstead of soil contamination.From urban to suburb place,sulfate in mature CTLs decreased as the atmospheric sulfur pollution reduced,but a dramatic increase presented near the seashore,where the marine sulfate emission and maritime activity pollution were significant.The sulfur concentration and speciation in mature CTLs effectively represented the long-term biological accumulation of atmosphericsulfur pollution in local environment.

  20. Novel antigenic specificity involving the blood group antigen, Lea, in combination with onco-developmental antigen, SSEA-1, recognized by two monoclonal antibodies to human milk-fat globule membranes.

    Science.gov (United States)

    Gooi, H C; Jones, N J; Hounsell, E F; Scudder, P; Hilkens, J; Hilgers, J; Feizi, T

    1985-09-16

    Two monoclonal antibodies to human milk-fat globule membranes, which recognize an epithelial antigen designated MAM-3c, were found to bind strongly to epithelial glycoproteins derived from non-secretors. Further investigations, using purified glycoproteins and structurally defined oligosaccharides, established that the optimal antigenic structure for both antibodies involves the Type 1 based blood group antigen, Lea, in combination with the Type 2 based onco-developmental antigen, SSEA-1, (Formula: see text) as in lacto-N-difucohexaose II. The antibodies may also react with the corresponding monofucosyl structures lacking the 3- or 4- linked fucose residues and to a lesser extent with the afucosyl tetrasaccharide sequence as in lacto-N-tetraose. The Lea and SSEA-1 antigens are known to occur on human epithelial glycoproteins. However, this is the first report of an antigenic specificity involving a combination of the Type 1 and Type 2 based fuco-oligosaccharides and occurring on epithelial glycoproteins. PMID:2413844