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  • 4301.
    Åman, Ken
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Westlund, Per-Olof
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    The Electron Spin Relaxation and Paramagnetic Relaxation Enhancement: an Application of the Stochastic Liouville Equation in the Langevin Form2004In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 102, no 9-10, p. 1085-1093Article in journal (Refereed)
    Abstract [en]

    A novel theoretical approach, based on the stochastic Liouville equation (SLE) in its Langevin form, is developed to describe paramagnetic relaxation enhancement (PRE). This approach is more applicable to different dynamic models than the old slow-motion theory which was based on the SLE in the operator or Fokker-Planck form. Moreover, the SLE in the Langevin form supplies a detailed description of the electron spin relaxation in the time domain. This new approach is applied to the analysis of the T1-NMRD profile of water protons in Ni2+(H2O)6.

  • 4302.
    Åmodt, Kristine
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Illegal handel av legemidler på internettUtviklingen i Norge og tollvesenets analysemetoder2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 4303.
    Åström, Helena
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Liposomalt vinkristin: Ett etablerat cytostatikum i ny beredningsform2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 4304.
    Öberg, Christopher T
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Strand, Mårten
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Andersson, Emma K
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Edlund, Karin
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Tran, Nam Phuong Nguyen
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Mei, Ya-Fang
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Wadell, Göran
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Elofsson, Mikael
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Synthesis, biological evaluation, and structure-activity relationships of 2-[2-(benzoylamino)benzoylamino]benzoic acid analogues as inhibitors of adenovirus replication2012In: Journal of Medicinal Chemistry, ISSN 0022-2623, E-ISSN 1520-4804, Vol. 55, no 7, p. 3170-3181Article in journal (Refereed)
    Abstract [en]

    2-[2-Benzoylamino)benzoylamino]benzoic acid (1) was previously identified as a potent and nontoxic antiadenoviral compound ( Antimicrob. Agents Chemother. 2010 , 54 , 3871 ). Here, the potency of 1 was improved over three generations of compounds. We found that the ortho, ortho substituent pattern and the presence of the carboxylic acid of 1 are favorable for this class of compounds and that the direction of the amide bonds (as in 1) is obligatory. Some variability in the N-terminal moiety was tolerated, but benzamides appear to be preferred. The substituents on the middle and C-terminal rings were varied, resulting in two potent inhibitors, 35g and 35j, with EC(50) = 0.6 μM and low cell toxicity.

  • 4305.
    Öberg, Kjell
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Berglund, Anders
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Edlund, Ulf
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Eliasson, Bertil
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Prediction of nonlinear optical responses of organic compounds2001In: Journal of Chemical Information and Modeling, Vol. 41, no 3, p. 811-4Article in journal (Refereed)
    Abstract [en]

    The nonlinear optical quantities, second and third harmonics ( and ), were predicted using a quantitative structure-property relationship (QSPR) approach. Molecular orbital ab initio calculations were applied to generate easily accessible variables to be used in the partial least-squares analysis. Simplified equations are presented that could be used to predict the experimental and responses, prior to further investigations of potentially interesting molecules for use in optical materials.

  • 4306.
    Öberg, Kjell
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Edlund, Ulf
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Eliasson, Bertil
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Shchukarev, Andrey
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Seshadri, Kannan
    Allara, David
    Spectroscopic Characterization of the Bonding, Orientation, and Coverage of Copper Tetraazaphthalocyanine Monolayer Films on SiO2 Surfaces2000In: The Journal of Physical Chemistry B, Vol. 104, no 45, p. 10627-34Article in journal (Refereed)
    Abstract [en]

    Self-assembled monolayer films of a metallotetraazaphthalocyanine were prepared using two different reaction conditions. The films were characterized by ellipsometry, AFM, electronic absorption spectroscopy, semiempirical MO calculations, core-level XPS, and projection of a calculated structure of the chromophore onto a surface to obtain its silhouette area for comparison with surface concentration from absorption spectroscopy. A denser packing of the chromophores is found in the SAM film prepared with bromonaphthalene at 250 C as compared with the film from the more polar solvent DMF at 120 C. Data is consistent with an almost vertical orientation of the chromophores in the former film. A different number of bonds connecting the chromophore with the coupling molecule is suggested as an explanation to differences in the absorption bands for the two films.

  • 4307.
    Öberg, Kjell
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Eliasson, Bertil
    Umeå University, Faculty of Science and Technology, Chemistry.
    A method for screening of coverage and film thickness of monolayers by projection of molecular electron density surface onto a substrate plane2001In: Materials Letters, Vol. 49, no 3-4, p. 147-153Article in journal (Refereed)
    Abstract [en]

    Self-assembled monolayer films of a copper tetraazaphthalocyanine have been prepared on quartz and silicon at 120°C in DMF solution and at 250°C in bromonaphthalene solution. A procedure is presented for obtaining film thickness for a sufficiently dense monolayer by fitting the 2D image of the 3D electron density surface of the chromophore in the film to a surface-coverage measure derived from absorption spectroscopy. The film thickness obtained by the electron density projection method is compared to that from ellipsometry. The projection method is expected to be useful for film-screening purposes and can also yield an average angle between the surface and chromophore normals.

  • 4308.
    Öberg, Kjell
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Persson, Per
    Umeå University, Faculty of Science and Technology, Chemistry.
    Shchukarev, Andrey
    Umeå University, Faculty of Science and Technology, Chemistry.
    Eliasson, Bertil
    Umeå University, Faculty of Science and Technology, Chemistry.
    Comparison of monolayer films of stearic acid and methyl stearate on an Al2O3 surface2001In: Thin Solid Films, Vol. 397, no 1-2, p. 102-8Article in journal (Refereed)
    Abstract [en]

    Both stearic acid and methyl stearate chemisorbs onto an oxide surface of aluminum with an asymmetric coordination of the carboxylate group as concluded from infrared (IR) spectroscopy data. Similarities in the IR spectra of the films from the two compounds suggest that the ester is bonded in the same way as the acid, and that the ester therefore undergoes hydrolysis during the surface reaction. X-Ray photoelectron spectroscopy (XPS) and IR data are interpreted in terms of self-assembled monolayer formation and a more dense film from the carboxylic acid in comparison with that from the ester.

  • 4309.
    Öberg, Lars
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Andersson, Barbro
    Umeå University, Faculty of Science and Technology, Chemistry.
    Andersson, Patrik
    Umeå University, Faculty of Science and Technology, Chemistry.
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Chemistry.
    Johansson, M
    Umeå University, Faculty of Science and Technology, Chemistry.
    Karlsson, S
    Lundstedt, Staffan
    Umeå University, Faculty of Science and Technology, Chemistry.
    Lövgren, Lars
    Umeå University, Faculty of Science and Technology, Chemistry.
    Marklund, Ann
    Umeå University, Faculty of Science and Technology, Chemistry.
    Nording, Malin
    Umeå University, Faculty of Science and Technology, Chemistry.
    Wiberg, Karin
    Umeå University, Faculty of Science and Technology, Chemistry.
    Undergraduate Education in Environmental Chemistry at Umeå University, Sweden2004In: SETAC 4th World Congress/25th Annual Meeting in North America, 14-18 November, Portland OR, USA, 2004Conference paper (Other academic)
    Abstract [en]

    Abstract to the Fourth SETAC World Congress, oral presentation.

  • 4310. Öberg, M
    et al.
    Andersson, Patrik
    Umeå University, Faculty of Science and Technology, Chemistry.
    Johansson, N
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Chemistry.
    Hâkansson, H
    Multivariate modelling of polychlorinated biphenyl-induced CYP1A activity in the MH1C1 rat hepatoma cell line2001In: ATLA Alternatives to Laboratory Animals, Vol. 29, no 3, p. 291-5Article, review/survey (Other (popular science, discussion, etc.))
  • 4311. Öberg, Mattias
    et al.
    Stern, Natalia
    Jensen, Sören
    Wesen, Clas
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Chemistry.
    Casabona, Helena
    Johansson, Niklas
    Blomgren, Kajsa
    Håkansson, Helen
    Subchronic toxicity of Baltic herring oil and its fractions in the rat I: Fractionation and levels of organohalogen pollutants2002In: Pharmacology & toxicology, Vol. 91, no 5, p. 220-31Article in journal (Refereed)
    Abstract [en]

    Baltic herring (Clupea harengus) oil was extracted and fractionated. To examine the contribution to toxicity and biological effects of different halogenated organic pollutants, the herring oil and the fractions were mixed into pelleted food and given to Sprague-Dawley female rats at three levels, corresponding to a human intake of 1.6, 8.2 and 34.4 kg fish per week. Herring oil, its fractions, as well as liver tissues from exposed rats, were analyzed for: eight chlorinated biphenyls, all 2,3,7,8-substituted chlorinated dibenzo-p-dioxins and dibenzofurans, hexachlorocyclohexanes, hexachlorobenzene, 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), DDT-metabolites, three brominated diphenylethers as well as extractable organically bound chlorine and halogenated fatty acids. A bioassay (EROD) was used for measuring the dioxin-like enzyme induction activity. Nordic Sea lodda (Mallotus villosus) oil was used as a nutritionally equivalent control, with much lower levels of halogenated organic pollutants. A full toxicological subchronic examination is reported in the following paper (Stern et al. 2002). In this study, we report that the fractionation procedure resulted in a substantial reduction of most of the pollutants in the triacylglycerol fraction, and a pronounced enrichment of most of the pollutants into the two other fractions. However, all contaminants were present at some levels in all of the fractions. The concentrations of organohalogens found in this study were representative for Baltic herring during the mid-1990s. Rat liver tissue showed similar residue patterns as the diet, with the exception of chlorinated dibenzo-p-dioxin and dibenzofuran congeners that had a higher liver retention than pesticides, chlorinated biphenyls and brominated diphenylethers.

  • 4312. Öberg, Mattias
    et al.
    Westerholm, Emma
    Fattore, Elena
    Stern, Natalia
    Hanberg, Annika
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wiberg, Karin
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Bergendorff, Anders
    Håkansson, Helen
    Toxicity of Bromkal 70-5DE, a technical mixture of polybrominated diphenyl ethers, following 28 d of oral exposure in rats and impact of analysed impurities2010In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 80, no 2, p. 137-143Article in journal (Refereed)
    Abstract [en]

    The subacute toxicity of a commercial polybrominated diphenyl ether (PBDE) preparation, Bromkal 70-5DE, was investigated. In addition to a vehicle control, the mixture was given orally to male and female Sprague-Dawley rats for 28d at three dose levels; 2.5, 25 and 250mgkg(-1) b.w.d(-1). The observed effects include increased hepatic EROD activity (from 2.5mgkg(-1)d(-1)); increased liver weight (males), increased PROD activity and depletion of hepatic retinoids (from 25mgkg(-1)d(-1)); and increased liver weight (females), marked histological changes in the liver and lungs, as well as increased serum parameters such as total protein, cholesterol and albumin (from 250mgkg(-1)d(-1)). Chemical analysis of the PBDE mixture with gas chromatography/mass spectrometry (GS/MS) showed impurities of polybrominated dibenzofurans and to a lesser extent dibenzodioxins, in total levels of about 7.0mugg(-1) of Bromkal technical mixture. The animals were thereby exposed to an estimated dose of dioxin-like equivalents corresponding to 1.3-131ng TEQkg(-1) b.w.d(-1). It cannot be ruled out that this level of impurities can explain the hepatic EROD induction and hepatic retinoid depletion, which are considered typical markers of toxicity mediated via the aryl hydrocarbon receptor (AhR).

  • 4313.
    Öhman, Anders
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Öman, Tommy
    Umeå University, Faculty of Science and Technology, Chemistry.
    Oliveberg, Mikael
    Solution structures and backbone dynamics of the ribosomal protein S6 and its permutant P(54-55)2010In: Protein science : a publication of the Protein Society, ISSN 1469-896X, Vol. 19, no 1, p. 183-9Article in journal (Refereed)
    Abstract [en]

    The ribosomal protein S6 from Thermus thermophilus has served as a model system for the study of protein folding, especially for understanding the effects of circular permutations of secondary structure elements. This study presents the structure of a permutant protein, the 96-residue P(54-55), and the structure of its 101-residue parent protein S6(wt) in solution. The data also characterizes the effects of circular permutation on the backbone dynamics of S6. Consistent with crystallographic data on S6(wt), the overall solution structures of both P(54-55) and S6(wt) show a beta-sheet of four anti-parallel beta-strands with two alpha-helices packed on one side of the sheet. In clear contrast to the crystal data, however, the solution structure of S6(wt) reveals a disordered loop in the region between beta-strands 2 and 3 (Leu43-Phe60) instead of a well-ordered stretch and associated hydrophobic mini-core observed in the crystal structure. Moreover, the data for P(54-55) show that the joined wild-type N- and C-terminals form a dynamically robust stretch with a hairpin structure that complies with the in silico design. Taken together, the results explain why the loop region of the S6(wt) structure is relatively insensitive to mutational perturbations, and why P(54-55) is more stable than S6(wt): the permutant incision at Lys54-Asp55 is energetically neutral by being located in an already disordered loop whereas the new hairpin between the wild-type N- and C-termini is stabilizing.

  • 4314. Öhman, David
    et al.
    Demedts, Brecht
    Kumar, Manoj
    Gerber, Lorenz
    Gorzsás, András
    Swedish University of Agricultural Sciences, Umeå.
    Goeminne, Geert
    Hedenström, Mattias
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Ellis, Brian
    Boerjan, Wout
    Sundberg, Björn
    MYB103 is required for FERULATE-5-HYDROXYLASE expression and syringyl lignin biosynthesis in Arabidopsis stems2013In: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313X, Vol. 73, no 1, p. 63-76Article in journal (Refereed)
    Abstract [en]

    The transcription factor (TF) MYB103 has earlier been identified as a member in the transcriptional network regulating secondary wall biosynthesis in xylem tissues of Arabidopsis and proposed to act on cellulose biosynthesis. It is a direct transcriptional target of the TF SECONDARY WALL ASSOCIATED NAC DOMAIN PROTEIN 1 (SND1), and 35S-driven dominant repression or over-expression of MYB103 modifies secondary wall thickness. We identified two myb103 T-DNA insertion mutants and chemically characterised their lignocellulose by pyrolysis-GC/MS, 2D NMR, FT-IR microspectroscopy and wet chemistry. The mutants developed normally but exhibited a large change in their cell wall chemistry, marked by a 70-75% decrease in syringyl (S) lignin. Guaiacyl (G) lignin was co-ordinately increased, so that total Klason lignin was not affected. Transcript abundance of FERULATE-5-HYDROXYLASE (F5H), the key gene in S-lignin biosynthesis, was strongly decreased in the myb103 mutants, and the metabolome of the myb103 mutant and of a null mutant in F5H was very similar. Other than the modification in lignin S to G ratio, there were only very minor changes in the composition of secondary cell wall polymers in the inflorescence stem. In conclusion, we demonstrate that F5H expression and, hence, S-lignin biosynthesis is dependent on MYB103. 

  • 4315.
    Öhman, Lars-Olof
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Equilibrium studies of ternary aluminium(III) hydroxo complexes with ligands related to conditions in natural waters1983Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The thesis is a summary and discussion of eight papers. During the last decades, precipitation has become increasingly acidic due to the extensive use of fossil fuels. In areas of poorly buffered bedrocks, e.g. Scandinavia, northeastern United States, this phenomenon has resulted in elevated amounts of Al(III) being leached into streams and lakes. Recent findings reveal that these elevated Al-concentrations could cause fish death and decreasing forest production.

    In the present thesis, the importance of taking naturally occurring substances into consideration when discussing Al(III) in natural waters, is emphasized. On the basis of a chemical characterization of relevant ligand classes in a natural water, the complex formation between Al^+, hydroxide ions and the inorganic ligand carbonic acid, the low-molecular weight organic ligand citric acid and the high-molecular weight model substances gallic acid, 1,2-dihydroxynaphtha-lene-4-sulfonate, 1,2-naphthoquinone-4-sulfonate, pyrocatechol and salicylic acid were investigated. The investigations were performed as series of Potentiometrie titrations and data were processed by means of the least-squares computer program LETAGROPVRID using a technique called pqr-analysis, permitting an unbiased search for complex model (and corresponding equilibrium constants) to be made. In most systems studied, the complexation at high ligand excesses can be described by a series of mononuclear complexes AIL-AIL^. Tentatively, the whole series consists of octahedrally coordinated (water and ligand oxygens) AI(III). At lower ligand excesses, the significance and in some cases even predominance of ternary mono- and polynuclear hydroxo complexes is demonstrated. In two of the systems, binary aluminium hydroxo species are evaluated.

    The potential importance of the substances with respect to Al-com-plexation in natural waters are indicated in a number of model calculations. The solubility of the clay mineral kaolinite is calculated as a function of -lg[H+] and ligand concentration. It is shown that citric acid, gallic acid, 1,2-dihydroxynaphthalene-4-sulfonate, pyrocatechol and salicylic acid contribute quite significant to the total solubilities, even at very low concentrations.

    As a complement and background to the equilibrium studies, the corrosion rate for one of the naturally occurring Al-bearing minerals, corundum, is reported. In this investigation, performed with a leach-ant solution of ground-water composition, an experimental technique was employed which made it possible to divide the corrosion into chemical and mechanical losses.

  • 4316.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Forsling, Willis
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Equilibrium and Structural Studies of Silicon(IV) and Aluminium(III) in Aqueous Solution: 3. Potentiometric Study of Aluminium(III) Hydrolysis and Aluminium(III) Hydroxo Carbonates in 0.6 M Na(Cl)1981In: Acta Chemica Scandinavica, ISSN 0302-4377, Vol. A 35, p. 795-802Article in journal (Refereed)
  • 4317.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Ganemi, B
    Björnbom, E
    Rahkamaa, K
    Keiski, R L
    Paul, J
    Catalyst preparation through ion-exchange of zeolite Cu-, Ni-, Pd-, CuNi- and CuPd-ZSM-52002In: Materials Chemistry and Physics, Vol. 73, no 2-3, p. 263-7Article in journal (Refereed)
    Abstract [en]

    Ion-exchanged zeolite ZSM-5 is the best known catalyst for direct NOx decomposition and a viable candidate for NOx reduction with methane. The preparation is crucial for the efficiency of the conversion and this paper describes the ion-exchange, with Cu2+, Ni2+ or Pd2+, and the dual exchange, with Cu2+/Ni2+ or Cu2+/Pd2+, under appropriate pH and ion concentrations for maximum dispersion.

  • 4318.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Ingri, N.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tegman, R.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Corrosion of Dense Polycrystalline -Al2O3 in NaHCO3-Buffered Water Solution of pH 8.5 at 40-100 °C1982In: American Ceramic Society Bulletin, ISSN 0002-7812, E-ISSN 1945-2705, Vol. 61, no 5, p. 567-571Article in journal (Refereed)
  • 4319.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lövgren, Lars
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Hedlund, Tomas
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sjöberg, Staffan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    The ionic strength dependency of mineral solubility and chemical speciation in solution2006In: Surface Complexation Modelling, Elsevier, 2006, p. 1-34Chapter in book (Other academic)
  • 4320.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Paul, J
    Materials aspects of titanium-doped aluminas: 14%Ti/-Al2O3/Cu and sulfided Al2O3-TiO2/NiMo2002In: Materials Chemistry and Physics, Vol. 73, no 2, p. 242-51Article in journal (Refereed)
    Abstract [en]

    Materials aspects of titanium-doped alumina catalysts are discussed in light of a partly new synthesis route, ion exchange reactions and sulfidation. Starting with a solution of the isopropoxides of aluminum and titanium, we aimed at an Al:Ti ratio of 6:1, which corresponds to the maximum acidity of the final product. Transmission electron micrographs showed that the synthesis gave a product of nearly monodisperse, rectangular particles and X-ray diffractograms revealed an amorphous to nano-crystalline structure reminiscent of -Al2O3. The Brunauer-Emmet-Teller area was 340m2g-1 and the H+ titration found 3acidic sitesnm-2. These numbers indicate that the titanium modification may fourfold increase the ion exchange capacity of a regular alumina. The importance of titanium modification for catalysis is discussed in connection with selective catalytic reduction with hydrocarbon reactions over Cu/14%Ti-Al2O3 and hydrogenation of 1-Me-naphthalene over sulfided NiMo/Al2O3-TiO2. The Ti4+ ions in the alumina lattice are almost irreducible, but infrared spectra suggested that these ions act as dispersion agents not only for adsorbed Cu2+ ions, but also for a supported phase of sulfided NiMo. Finally, we show that a simple weight control can be used to monitor the sulfidation and to indicate if the synthesis has produced a separate, reducible titania phase.

  • 4321.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sjöberg, Staffan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Equilibrium and Structural Studies of Silicon(IV) and Aluminium(III) in Aqueous Solution: 1. The Formation of Ternary Mononuclear and Polynuclear Complexes in the System Al(3+)--Gallic Acid--OH-. A Potentiometric Study in 0.6 M Na(Cl)1981In: Acta Chemica Scandinavica, ISSN 0302-4377, Vol. A 35, p. 201-212Article in journal (Refereed)
  • 4322.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sjöberg, Staffan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Equilibrium and Structural Studies of Silicon(IV) and Aluminium(III) in Aqueous Solution: 4. A Potentiometric Study of Polynuclear Aluminium(III) Hydroxo Complexes with Gallic Acid in Hydrolyzed Aluminium(III) Solutions.1982In: Acta Chemica Scandinavica, ISSN 0302-4377, Vol. A 36, p. 47-53Article in journal (Refereed)
  • 4323.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sjöberg, Staffan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Equilibrium and Structural Studies of Silicon(IV) and Aluminium(III) in Aqueous Solution: 8. A potentiometric study of aluminium(III) Salicylates and Aluminium(III) Hydroxo Salicylates in 0.6 M Na(C1)1983In: Acta Chemica Scandinavica. Series A., ISSN 0302-4377, Vol. 37, p. 875-880Article in journal (Refereed)
  • 4324.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sjöberg, Staffan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Equilibrium and Structural Studies of Silicon(IV) and Aluminium(III) in Aqueous Solution: Part 9. A Potentiometric Study of Mono- and Polynuclear Aluminium(III)-Citrates1983In: Journal of the Chemical Society. Dalton Transactions, ISSN 1472-7773, E-ISSN 1364-5447, no 11, p. 2513-2517Article in journal (Refereed)
  • 4325.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sjöberg, Staffan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Equilibrium and structural studies of silicon(IV) and aluminium(III) in aqueous solution—10: A potentiometric study of aluminium(III) pyrocatecholates and aluminium(III) hydroxo pyrocatecholates in 0.6 M Na(Cl)1983In: Polyhedron, ISSN 0277-5387, E-ISSN 1873-3719, Vol. 2, no 12, p. 1329-1335Article in journal (Refereed)
  • 4326.
    Öhman, Lars-Olof
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sjöberg, Staffan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Ingri, Nils
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Equilibrium and Structural Studies of Silicon(IV) and Aluminium(III) in Aqueous Solution: 7. Redox, Hydrolysis and Complexation Equilibria in the System Al(3+)-1,2-Naphthoquinone-4-sulfonate/1,2-Dihydroxy-naphthalene-4-sulfonate-OH(-). A Potentiometric Study in 0.6 M Na(Cl)1983In: Acta Chemica Scandinavica, ISSN 0302-4377, Vol. A 37, p. 561-568Article in journal (Refereed)
  • 4327.
    Öhman, Marcus
    et al.
    Umeå University, Faculty of Science and Technology, Chemistry.
    Nordin, Anders
    Umeå University, Faculty of Science and Technology, Chemistry.
    Skrifvars, Bengt-Johan
    Backman, Rainer
    Hupa, Mikko
    Bed Agglomeration Characteristics during Fluidized Bed Combustion of Biomass Fuels2000In: Energy Fuels, Vol. 14, no 1, p. 169-78Article in journal (Refereed)
    Abstract [en]

    The in-bed behavior of ash-forming elements in fluidized bed combustion (FBC) of different biomass fuels was examined by SEM/EDS analysis of samples collected during controlled agglomeration test runs. Eight fuels were chosen for the test. To cover the variations in biomass characteristics and to represent as many combinations of ash-forming elements in biomass fuels as possible, the selection was based on a principal-component analysis of some 300 biomass fuels, with respect to ash-forming elements. The fuels were then combusted in a bench-scale fluidized bed reactor (5 kW), and their specific agglomeration temperatures were determined. Bed samples were collected throughout the tests, and coatings and necks formed were characterized by SEM/EDS analyses. On the basis of their compositions, the corresponding melting behaviors were determined, using data extracted from phase diagrams. The bench-scale reactor bed samples were finally compared with bed samples collected from biomass-fired full-scale fluidized bed boilers. In all the analyzed samples, the bed particles were coated with a relatively homogeneous ash layer. The compositions of these coatings were most commonly constricted to the ternary system K2O-CaO-SiO2. Sulfur and chlorine were further found not to "participate" in the agglomeration mechanism. The estimated melting behavior of the bed coating generally correlated well with the measured agglomeration temperature, determined in the 5 kW bench-scale fluidized bed reactor. Thus, the results indicate that partial melting of the coating of the bed particles would be directly responsible for the agglomeration.

  • 4328. Öhrvik, Helena
    et al.
    Wittung-Stafshede, Pernilla
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Identification of New Potential Interaction Partners for Human Cytoplasmic Copper Chaperone Atox1: Roles in Gene Regulation?2015In: International Journal of Molecular Sciences, ISSN 1422-0067, E-ISSN 1422-0067, Vol. 16, no 8, p. 16728-16739Article in journal (Refereed)
    Abstract [en]

    The human copper (Cu) chaperone Atox1 delivers Cu to P-1B type ATPases in the Golgi network, for incorporation into essential Cu-dependent enzymes. Atox1 homologs are found in most organisms; it is a 68-residue ferredoxin-fold protein that binds Cu in a conserved surface-exposed Cys-X-X-Cys (CXXC) motif. In addition to its well-documented cytoplasmic chaperone function, in 2008 Atox1 was suggested to have functionality in the nucleus. To identify new interactions partners of Atox1, we performed a yeast two-hybrid screen with a large human placenta library of cDNA fragments using Atox1 as bait. Among 98 million fragments investigated, 25 proteins were found to be confident interaction partners. Nine of these were uncharacterized proteins, and the remaining 16 proteins were analyzed by bioinformatics with respect to cell localization, tissue distribution, function, sequence motifs, three-dimensional structures and interaction networks. Several of the hits were eukaryotic-specific proteins interacting with DNA or RNA implying that Atox1 may act as a modulator of gene regulation. Notably, because many of the identified proteins contain CXXC motifs, similarly to the Cu transport reactions, interactions between these and Atox1 may be mediated by Cu.

  • 4329.
    Öman, Tommy
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Multivariate Analysis of 2D-NMR Spectroscopy: Applications in wood science and metabolomics2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Wood is our most important renewable resource. We need better quality and quantity both according to the wood itself and the processes that are using wood as a raw material. Hence, the understanding of the chemical composition of the wood is of high importance. Improved and new methods for analyzing wood are important to achieve better knowledge about both refining processes and raw material. The combination of NMR and multivariate analyses (MVA) is a powerful method for these analyses but so far it has been limited mainly to 1D NMR. In this project, we have developed methods for combining 2D NMR and MVA in both wood analysis and metabolomics. This combination was used to compare samples from normal wood and tension wood, and also trees with a down regulation of a pectin responsible gene. Dissolving pulp was also examined using the same combination of 2D-NMR and MVA, together with FT-IR and solid state 13C CP-MAS NMR. Here we focused on the difference between wood type (softwood and hardwood), process type (sulfite and sulfate) and viscosity. These methods confirmed and added knowledge about the dissolving pulp. Also reactivity was compared in relation to morphology of the cellulose and pulp composition. Based on the method and software used in the wood analysis projects, a new method called HSQC-STOCSY was developed. This method is especially suited for assignment of substances in complex mixtures. Peaks in 2D NMR spectra that correlate between different samples are plotted in correlation plots resembling regular NMR spectra. These correlation plots have great potential in identifying individual components in complex mixtures as shown here in a metabolic data set. This method could potentially also be used in other areas such as drug/target analyses, protein dynamics and assignment of wood spectra.

  • 4330.
    Öman, Tommy
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Reactivity of dissolving pulp analyzed with multivariate data analysis of XRD and NMR data.Manuscript (preprint) (Other academic)
  • 4331.
    Öman, Tommy
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tessem, Maj-Britt
    Bathen, Tone F
    Bertilsson, Helena
    Angelsen, Anders
    Hedenström, Mattias
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Andreassen, Trygve
    Identification of metabolites from 2D 1H-13C HSQC NMR using peak correlation plots2014In: BMC Bioinformatics, ISSN 1471-2105, E-ISSN 1471-2105, Vol. 15, article id 413Article in journal (Refereed)
    Abstract [en]

    Background: Identification of individual components in complex mixtures is an important and sometimes daunting task in several research areas like metabolomics and natural product studies. NMR spectroscopy is an excellent technique for analysis of mixtures of organic compounds and gives a detailed chemical fingerprint of most individual components above the detection limit. For the identification of individual metabolites in metabolomics, correlation or covariance between peaks in 1H NMR spectra has previously been successfully employed. Similar correlation of 2D 1H-13C Heteronuclear Single Quantum Correlation spectra was recently applied to investigate the structure of heparine. In this paper, we demonstrate how a similar approach can be used to identify metabolites in human biofluids (post-prostatic palpation urine).

    Results: From 50 1H-13C Heteronuclear Single Quantum Correlation spectra, 23 correlation plots resembling pure metabolites were constructed. The identities of these metabolites were confirmed by comparing the correlation plots with reported NMR data, mostly from the Human Metabolome Database.

    Conclusions: Correlation plots prepared by statistically correlating 1H-13C Heteronuclear Single Quantum Correlation spectra from human biofluids provide unambiguous identification of metabolites. The correlation plots highlight cross-peaks belonging to each individual compound, not limited by long-range magnetization transfer as conventional NMR experiments.

  • 4332. Öquist, Mats G.
    et al.
    Erhagen, Björn
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Department of Forest Ecology & Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden.
    Haei, Mahsa
    Sparrman, Tobias
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Ilstedt, Ulrik
    Schleucher, Jürgen
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Nilsson, Mats B.
    The effect of temperature and substrate quality on the carbon use efficiency of saprotrophic decomposition2017In: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 414, no 1, p. 113-125Article in journal (Refereed)
    Abstract [en]

    Background and aims: Mineralization of soil organic matter (SOM) constitutes a major carbon flux to the atmosphere. The carbon use efficiency (CUE) of the saprotrophic microorganisms mineralizing SOM is integral for soil carbon dynamics. Here we investigate how the CUE is affected by temperature, metabolic conditions, and the molecular complexity of the substrate.

    Methods: We incubated O-horizon soil samples (with either 13C–glucose or 13C–cellulose) from a boreal coniferous forest at 4, 9, 14, and 19 °C, and calculated CUEs based on the amount of 13C–CO2and 13C–labelled microbial biomass produced. The effects of substrate, temperature, and metabolic conditions (representing unlimited substrate supply and substrate limitation) on CUE were evaluated.

    Results: CUE from metabolizing glucose was higher as compared to cellulose. A slight decrease in CUE with increasing temperature was observed in glucose amended samples (but only in the range 9–19 °C), but not in cellulose amended samples. CUE differed significantly with metabolic conditions, i.e. CUE was higher during unlimited growth conditions as compared to conditions with substrate limitation.

    Conclusions: We conclude that it is integral to account for both differences in CUE during different metabolic phases, as well as complexity of substrate, when interpreting temperature dependence on CUE in incubation studies.

  • 4333. Öquist, Mats
    et al.
    Sparrman, Tobias
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Klemedtsson, Leif
    Harrysson Drotz, Stina
    Grip, Harald
    Schleucher, Jürgen
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Nilsson, Mats
    Water availability controls microbial temperature responses in frozen soil CO2 production2009In: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 15, no 11, p. 2715-22Article in journal (Refereed)
    Abstract [en]

    Soil processes in high-latitude regions during winter are important contributors to global carbon circulation, but our understanding of the mechanisms controlling these processes is poor and observed temperature response coefficients of CO2 production in frozen soils deviate markedly from thermodynamically predicted responses (sometimes by several orders of magnitude). We investigated the temperature response of CO2 production in 23 unfrozen and frozen surface soil samples from various types of boreal forests and peatland ecosystems and also measured changes in water content in them after freezing. We demonstrate that deviations in temperature responses at subzero temperatures primarily emanates from water deficiency caused by freezing of the soil water, and that the amount of unfrozen water is mainly determined by the quality of the soil organic matter, which is linked to the vegetation cover. Factoring out the contribution of water limitation to the CO2 temperature responses yields response coefficients that agree well with expectations based on thermodynamic theory concerning biochemical temperature responses. This partitioning between a pure temperature response and the effect of water availability on the response of soil CO2 production at low temperatures is crucial for a thorough understanding of low-temperature soil processes and for accurate predictions of C-balances in northern terrestrial ecosystems.

  • 4334.
    Örjansen, Beate
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Kan probiotika forebygge utviklingen av eller behandle atopisk eksem hos barn?2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 4335. Örtenblad, Marcus
    et al.
    Parola, Stephane Chaput, Frédéric Desroches, Cédric Sigala, Catherine Létoffé, Jean Marie Miele, Philippe Baldeck, Patrice L. Eliasson, Bertil Umeå University, Faculty of Science and Technology, Chemistry.Eriksson, Anders Lopes, Cesar
      Hybrid Materials for Optical Limiting        2005Conference proceedings (editor) (Other academic)
    Abstract [en]

    Optical limiting materials based on alkynyl platinum derivatives and thiacalixarenes were produced using the sol-gel process. The molecular species were grafted to the matrix (class II hybrid) in order to maximise the concentration and the stability of the material. Broadband optical limiting performances in the visible wavelength region was observed in the prepared materials. Thermomechanical characterisation of the matrix will also be discussed.

  • 4336.
    Österberg, Sofia
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    How can pharmacists contribute to a more effective care of patients with hypertension or diabetes?: How can pharmacists contribute to a more effective care of patients with hypertension or diabetes?2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 4337.
    Österberg, Sofia
    et al.
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Åberg, Anna
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Herrera Seitz, M. Karina
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Wolf-Watz, Magnus
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Shingler, Victoria
    Umeå University, Faculty of Science and Technology, Department of Molecular Biology (Faculty of Science and Technology).
    Genetic dissection of a motility-associated c-di-GMP signalling protein of Pseudomonas putida2013In: Environmental Microbiology Reports, ISSN 1758-2229, E-ISSN 1758-2229, Vol. 5, no 4, p. 556-565Article in journal (Refereed)
    Abstract [en]

    Lack of the Pseudomonas putidaPP2258 protein or its overexpression results in defective motility on solid media. The PP2258 protein is tripartite, possessing a PAS domain linked to two domains associated with turnover of c-di-GMP - a cyclic nucleotide that controls the switch between motile and sessile lifestyles. The second messenger c-di-GMP is produced by diguanylate cyclases and degraded by phosphodiesterases containing GGDEF and EAL or HD-GYP domains respectively. It is common for enzymes involved in c-di-GMP signalling to contain two domains with potentially opposing c-di-GMP turnover activities; however, usually one is degenerate and has been adopted to serve regulatory functions. Only a few proteins have previously been found to have dual enzymatic activities - being capable of both synthesizing and hydrolysing c-di-GMP. Here, using truncated and mutant derivatives of PP2258, we show that despite a lack of complete consensus in either the GGDEF or EAL motifs, the two c-di-GMP turnover domains can function independently of each other, and that the diguanylate cyclase activity is regulated by an inhibitory I-site within its GGDEF domain. Thus, motility-associated PP2258 can be added to the short list of bifunctional c-di-GMP signalling proteins.

  • 4338.
    Österlund, Lise-Lotte
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Redox models in chemistry:  A depiction of the conceptions held by secondary school students of redox reactions2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    According to previous research, students show difficulties in learning redox reactions. By the historical development different redox models exist to explain redox reactions, the oxygen model, the hydrogen model, the electron model and the oxidation number model. This thesis reports about three studies concerning conceptions held by secondary school students of redox reactions. A textbook analysis is also included in the thesis.

    The first study was an investigation of the students’ use of redox models in inorganic contexts, their use of the activity series of metals, and the students’ ability to transfer redox knowledge. Then the students’ work with an open-ended biochemical task, where the students had access of the textbook was studied. The students talk about redox reactions, the questions raised by the students, what resources used to answer the questions and what kind of talk developed were investigated. A textbook analysis based on chemistry books from Sweden and one book from England was performed. The redox models used as well as the dealing with redox related learning difficulties was studied. Finally, the students’ conceptions about redox in inorganic, organic and biochemistry after completed chemistry courses were studied.

    The results show that the students were able to use the electron model as a tool to explain inorganic redox reactions and the mutuality of oxidation and reduction was fundamental. The activity series of metals became a tool for the prediction of reducing agent in some reactions. Most of the students rejected that oxygen is a prerequisite for a redox reaction. In the biochemical task the resource most used to answer the raised questions were the students’ consultation of the textbook – together or individually. Most questions resulted in short answers and the majority of these questions were answered. Questions concerning redox were analysed by the students and integrated into a chemical context but they could neither identify the substances oxidised or reduced nor couple the concepts to transfer of hydrogen atoms. The majority of these redox questions became unanswered. The textbook helped the students to structure a poster as well as to answer basic chemistry questions. For questions about organic and biochemical redox, the book was of no help. The textbook analysis showed that all historical redox models are used. Different models are used in inorganic, organic and biochemistry. The mutuality of oxidation and reduction is treated differently in subject areas. The textbooks did not help the reader linking the different redox models that were used. Few redox-related learning difficulties are addressed in the books. After completed chemistry courses the students had major problems to justify a redox reaction explained by transfer of hydrogen atoms both in the organic and biochemistry examples.

  • 4339.
    Österlund, Lise-Lotte
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    The conceptions held by upper secondary school students of redox reactions in inorganic, organic and biochemistryManuscript (preprint) (Other academic)
    Abstract [en]

     The aim of this study was to investigate the conceptions held by upper secondary school students’ of redox reactions after their completed chemistry course. Semi-structured group interviews were carried out around examples of redox phenomena in inorganic, organic and biochemistry. Additional stimuli such as pictures and passages from the textbook were used to encourage the students to reveal their redox knowledge. In total, 17 students participated. The results indicate that the electron model seems to be reinforced in the inorganic example and becomes a tool in the students’ explanations. The students had difficulties in using the hydrogen model in organic and biochemistry. In organic chemistry, some students questioned how hydrogen loss can be considered to be an oxidation. In biochemistry, many students mixed redox models to explain the reaction.

  • 4340.
    Österlund, Lise-Lotte
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Berg, Anders
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education.
    Ekborg, Margareta
    School of Teacher Education, Malmö University, Malmö, Sweden.
    Redox models in chemistry textbooks for the upper secondary school: friend or foe?2010In: Chemistry Education Research and Practice, ISSN 1109-4028, Vol. 11, p. 182-192Article in journal (Refereed)
    Abstract [en]

     We have investigated how chemistry textbooks use models of redox reactions in different subject areas, how they change models between and within the topics, and how they deal with specific learning difficulties identified in the literature. The textbooks examined were published for use in the natural science programme in Swedish upper secondary schools and in the UK A-level course. As a starting point, the defined redox models found in the literature were used to investigate the textbooks. The results show that all redox models are used with the addition of alternative representations. Authors exclusively use the electron and the oxidation number models in inorganic chemistry. In organic chemistry, the oxygen and hydrogen model are used, and in biochemistry mainly hydrogen and alternative representations. There is no guide to changes of models between the subject areas. However, within the inorganic chemistry, authors guide model change which was not identified in either organic or biochemistry. Regarding the learning difficulties, the authors dealt with just a few of them.

  • 4341.
    Östman, Marcus
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Antimicrobials in sewage treatment plants: occurrence, fate and resistance2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The World Health Organization (WHO) has identified antibiotic resistance as a major threat to human health. The environment has been suggested to play an important role in the emergence of antibiotic resistant bacteria. The external environment can act as a source of resistance genes that could potentially be transferred into human pathogens. It is also an important route for the dissemination of antibiotic resistance genes and bacteria. Sewage treatment plants (STPs) are among the most important routes by which antibiotics and antibiotic resistance genes enter the environment. It has been suggested that STPs are hotspots for the development of antibiotic resistance because they contain relatively high concentrations of antibiotics as well as both human and environmental bacteria. Further complicating matters, there is evidence that other substances with antimicrobial properties, such as biocides and metals, can cause antibiotic resistance due to co- and cross-resistance.

    This thesis contributes new knowledge on the concentrations, mass flows, and removal efficiencies of antimicrobials in STPs and their connections to the emergence of antibiotic resistance. Paper I presents data on the levels of 40 different antimicrobials in the incoming wastewater, treated effluent, and digested sludge of eleven different STPs. Although not previously detected in STPs, chlorhexidine is shown to be ubiquitous in such plants. In Paper II, mass flows and removal efficiencies are calculated for eleven antimicrobials over various treatment steps in three STPs, showing that polar antimicrobials were inefficiently removed from the wastewater. In Paper III, the minimum selective concentration (MSC) for the antibiotic tetracycline was determined in a complex bacterial aquatic biofilm using both phenotypic and genotypic endpoints. It was found that 10 µg/L selected for phenotypic resistance, and 1 µg/L selected for certain resistance genes. Paper VI used metagenomics to determine whether there is selection for antibiotic-resistant bacteria in STPs and whether the extent of this selection can be correlated to the concentrations of antimicrobial compounds. No clear evidence for selection was identified. Paper V evaluates advanced wastewater treatment techniques for removing antimicrobial compounds using ozonation and granular activated carbon (GAC). The identity of the GAC material was found to strongly affect removal efficiency, and GAC was more efficient than ozonation for most compounds at the tested concentrations.

  • 4342.
    Östman, Marcus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Björlenius, Berndt
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Effect of full-scale ozonation and pilot-scale granular activated carbon on the removal of biocides, antimycotics and antibiotics in a sewage treatment plant2019In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 649, p. 1117-1123Article in journal (Refereed)
    Abstract [en]

    Several micropollutants show low removal efficiencies in conventional sewage treatment plants, and therefore enter the aquatic environment. To reduce the levels of micropollutants in sewage effluent, and thereby the effects on biota, a number of extra treatment steps are currently being evaluated. Two such techniques are ozonation and adsorption onto activated carbon. In this study, we investigated the efficiency of Sweden's first full-scale ozonation treatment plant at removing a number of antibiotics, antimycotics and biocides. The effect of adding granular activated carbon (GAC) on a pilot scale and pilot-scale ozonation were also evaluated. The conventional treatment (13,000 PE) with the add-on of full-scale ozonation (0.55 g O3/g Total organic carbon (TOC)) was able to remove most of the studied compounds (>90%), except for benzotriazoles and fluconazole (<50%). Adsorption on GAC on a pilot scale showed a higher removal efficiency than ozonation (>80% for all studied compounds). Three types of GAC were evaluated and shown to have different removal efficiencies. In particular, the GAC with the smallest particle sizes exhibited the highest removal efficiency. The results demonstrate that it is important to select an appropriate type of carbon to achieve the removal goal for specific target compounds.

  • 4343.
    Östman, Marcus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Näsström, Elin
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lindberg, Richard
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    A snapshot of illicit drug use in Sweden acquired through sewage water analysis2014In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 472, p. 862-871Article in journal (Refereed)
    Abstract [en]

    Analytical measurements of sewage water have been used many times to estimate the consumption of specific drugs in an area. This study measured a large number of illicit drugs and metabolites (>30) at a large number of sewage treatment plants (STPs) distributed across Sweden. Twenty-four illicit and prescription drugs, classified as narcotic substances in Sweden, and seven selected metabolites were included in the study. A 24 hour composite sample of incoming sewage water was collected from 33 different municipalities at various geographic locations across Sweden. Species were analyzed using an on-line solid-phase extraction-liquid chromatography electrospray tandem mass spectrometry method. The method proved to be rapid with minimum need for sample work up and was able to detect 13 compounds above their respective limits of quantification. The results for all compounds were presented as per capita loads. Multivariate data analysis was used to relate drug consumption to geographical location and/or population of cities. The results showed that geographical differences in drug consumption were apparent across the country. For the narcotic pharmaceuticals, the geographical differences suggested by the multivariate model were supported by prescription statistics. (C) 2013 Elsevier B.V. All rights reserved.

  • 4344.
    Östman, Marcus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Detailed mass flows and removal efficiencies for biocides and antibiotics in Swedish sewage treatment plants2018In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 640, p. 327-336Article in journal (Refereed)
    Abstract [en]

    Antimicrobial compounds, such as biocides and antibiotics, are widely used in society with significant quantities of these chemicals ending up in sewage treatment plants (STPs). In this study, mass flows and removal efficiency in different treatment steps at three Swedish STPs were evaluated for eleven different biocides and antibiotics. Mass flows were calculated at eight different locations (incoming wastewater, water after the first sedimentation step, treated effluent, primary sludge, surplus sludge, digested sludge, dewatered digested sludge and reject water). Samples were collected for a total of nine days over three weeks. The STPs were able to remove 53-> 99% of the antimicrobial compounds and 0-64% were biodegraded on average in the three STPs. Quaternary ammonium compounds were removed from the wastewater N99%, partly through biodegradation, but 38-96% remained in the digested sludge. Chlorhexidine was not biodegraded but was efficiently removed from the wastewater to the sludge. The biological treatment step was the most important step for the degradation of the studied compounds, but also removed several compounds through the surplus sludge. Compounds that were inefficiently removed included benzotriazoles, trimethoprim and fluconazole. The study provides mass flows and removal efficiencies for several compounds that have been seldom studied. 

  • 4345.
    Östman, Marcus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Lindberg, Richard H.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Fick, Jerker
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Björn, Erik
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Screening of biocides, metals and antibiotics in Swedish sewage sludge and wastewater2017In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 115, p. 318-328Article in journal (Refereed)
    Abstract [en]

    Incoming sewage water, treated effluent and digested sludge were collected from 11 Swedish sewage treatment plants (STPs) on 3 different days. Analytical protocols were established for a large number of compounds (47) with antimicrobial properties and the collected samples were then screened for the presence of these selected substances. Liquid chromatography tandem mass spectrometry (LC-MS/MS) and inductively coupled plasma mass spectrometry (ICP-MS) were used to analyse the samples. Thirty organic compounds and 10 metals were detected above their respective detection limit. Quaternary ammonium compounds were the most abundant substances in the particulate phases with levels up to 370 μg/g and benzotriazoles were the most common in the aqueous phases with levels up to 24 μg/L. Several compounds with no, or very limited, previously reported data were detected in this study, including chlorhexidine, hexadecylpyridinium chloride and 10-benzalkonium chloride. Some of these were both frequently detected (>60% detection frequency) and found in high levels (up to 19 μg/g d.w. sludge). This study gives a comprehensive overview of the presence in Swedish STPs of a number of antimicrobial substances, providing crucial information in designing relevant studies on potential microbial co- and cross resistance development between antibiotics, biocides, and metals in the sewage system.

  • 4346.
    Östman, Marcus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Näsström, Elin
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Construction of a Labview controlled pyrolysis unit for coupling to a Pyrola 85 pyrolysis chamber2012Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Pyrolysis is the process of molecular decomposition in an inert environment using heat. It is possible to fragment large molecules, such as polymers, by pyrolysis and separate the fragments directly in a GC. This makes it possible to form complex sample fingerprints that can be used in various applications, for example in forensic science.

    In this project, a malfunctioning Pyrola 85 pyrolysis unit was fixed by measuring the voltage signals from the photo diode during pyrolysis in a Labview program. With the Labview program, a partly manual filament temperature calibration procedure was developed, as replacement for the non-working automatic calibration procedure. The functioning pyrolysis unit was then installed on a GC/MS in the National University of Science, Ho Chi Minh City, Vietnam. Plant samples were analysed with the Pyrolysis-GC/MS system as a test of the system, resulting in pyrograms with a few identifiable peaks. However, both pyrolysis and GC/MS settings needs further investigation to optimize the analysis.

    In Sweden, a Labview controlled Pyrolysis unit was constructed to investigate the possibility of improving certain functions of the original control unit. A proposed Labview program and circuit boards were constructed and partially evaluated. The accuracy and precision of the pulses from the Labview program was

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