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  • 1.
    Abbrent, Sabina
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Lithium ion interactions in polymer gel electrolytes: Effect on structure, dynamics and morphology2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Polymer electrolytes are an essential part of the modern all-solid lithium battery. Several properties, such as mechanical and thermal stability, good ionic conductivity and compatibility with other materials used in the battery are necessary for a successful material.

    This thesis is focused on the ionic interactions in two electrolyte systems, based on a cross-linked polyethylene oxide (nona(ethylene oxide)dimethacrylate) or a fluorinated copolymer (polyvinylidene fluoride-hexafluoropropylene). Changes of thermal properties and morphology of and coordination in the electrolyte on addition of a lithium salt (LiTFSI) and different types and concentrations of solvents are studied. These properties are shown to control the ionic conductivity of the resulting material, influencing the conductivity mechanism.

    The presumably inert polyvinylidene fluoride is shown to undergo large structural changes, where polar conformations of the polymer backbone appear on salt addition, inducing a different crystalline phase. The lithium cation in the polyethylene oxide based electrolyte can coordinate either to the polymer chain or to the solvent. In for example systems containing propylene carbonate, the lithium ion binds more strongly to the polymer than to the solvent. This is in contrast to the systems with dimethyl sulphoxide where the ion prefers the solvent. This variation in coordination also strongly affects the mobility of the cation, reflected both in diffusion constants and in conductivity data.

    A combination of techniques was necessary to use for a deeper understanding of these complex materials. Coordination has been studied by FTIR and high resolution NMR, dynamics by NMR diffusion measurements and impedance spectroscopy, and morphology by diffraction techniques and DSC.

  • 2.
    Abbrent, Sabina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Lindgren, J
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Tegenfeldt, J
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Wendsjö, Å
    Gel electrolytes prepared from oligo(ethylene glycol)dimethacrylate: glass transition, conductivity and Li+-coordination1998In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 43, no 10-11, p. 1185-1191p. 1185-1191Article in journal (Refereed)
    Abstract [en]

    The influence of two plasticizers, propylene carbonate and dimethyl sulphoxide, as well as different salt concentrations of Li(TFSI), on properties of a polymer gel electrolyte material has been studied using differential scanning calorimetry (DSC) and ac impedance and FTIR spectroscopy. Variations of glass transition temperature and the conductivity behaviours of the systems were examined, and found to be highly dependent on the amount and type of the plasticizer used. Characteristic band-shifts in FTIR spectra, indicating coordination of lithium ions, have been found for the polymer and both the plasticizers in the corresponding binary solutions. These shifts were used to study the coordination preferences in the complete ternary electrolyte system. The combined results from the three experimental techniques have been discussed.

  • 3.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Accelerator mass spectrometry group. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Wolpher, Henriette
    Johansson, Olof
    Larsson, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Kritikos, Mikael
    Eriksson, Lars
    Norrby, Per-Ola
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Sun, Licheng
    Åkermark, Björn
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    A New Strategy for the Improvement of Photophysical Properties in Ruthenium(II) Polypyridyl Complexes: Synthesis and Photophysical and Electrochemical Characterization of Six Mononuclear Ruthenium(II) Bisterpyridine-Type Complexes2005In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 44, no 9, p. 3215-3225Article in journal (Refereed)
  • 4.
    Agback, M
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry. Kvantkemi.
    Lunell, S
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Quantum Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Hussenius, A
    Department of Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Matsson, O
    Department of Chemistry. Chemistry, Department of Physical and Analytical Chemistry, Quantum Chemistry.
    Theoretical studies of proton transfer reactions in 1-methylindene1998In: ACTA CHEMICA SCANDINAVICA, ISSN 0904-213X, Vol. 52, no 5, p. 541-548Article in journal (Refereed)
    Abstract [en]

    The base-catalysed 1,3-proton transfer reactions in 1-methylindene have been studied theoretically in polar (water) and unpolar (cyclohexane) solvents, respectively, for two different choices of bases, namely ammonia and trimethylamine (TMA), using the SM

  • 5.
    Aggeryd, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Bestämning av Substitutionsgraden hos Natrium-karboxymetylcellulosa, CMC: En tillämpning av den utvidgade Henderson-Hasselbalchs ekvation och simplex-optimering för bestämning av ekvivalensvolymer vid potentiometrisk titrering1984Licentiate thesis, monograph (Other academic)
  • 6.
    Ahlgren, Joakim
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Tranvik, Lars
    Gogoll, Adolf
    Waldebäck, Monica
    Markides, Karin
    Rydin, Emil
    Depth attenuation of biogenic phosphorus compounds in lake sediment measured by 31P NMR2005In: Environmental Science and Technology, ISSN 0013-936, Vol. 39, no 3, p. 867-872Article in journal (Refereed)
  • 7.
    Ahlgren, Joakim
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Tranvik, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Waldebäck, Monica
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Markides, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Rydin, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Sediment Depth Attenuation of Biogenic Phosphorus Compounds Measured by 31P NMR2005In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 39, no 3, p. 867-872Article in journal (Refereed)
    Abstract [en]

    Being a major cause of eutrophication and subsequent loss of water quality, the turnover of phosphorus (P) in lake sediments is in need of deeper understanding. A major part of the flux of P to eutrophic lake sediments is organically bound or of biogenic origin. This P is incorporated in a poorly described mixture of autochthonous and allochthonous sediment and forms the primary storage of P available for recycling to the water column, thus regulating lake trophic status. To identify and quantify biogenic sediment P and assess its lability, we analyzed sediment cores from Lake Erken, Sweden, using traditional P fractionation, and in parallel, NaOH extracts were analyzed using 31P NMR. The surface sediments contain orthophosphates (ortho-P) and pyrophosphates (pyro-P), as well as phosphate mono- and diesters. The first group of compounds to disappear with increased sediment depth is pyrophosphate, followed by a steady decline of the different ester compounds. Estimated half-life times of these compound groups are about 10 yr for pyrophosphate and 2 decades for mono- and diesters. Probably, these compounds will be mineralized to ortho-P and is thus potentially available for recycling to the water column, supporting further growth of phytoplankton. In conclusion, 31P NMR is a useful tool to asses the bioavailability of certain P compound groups, and the combination with traditional fractionation techniques makes quantification possible.

  • 8. Ahmed, Naima Abdel Kader
    et al.
    Liminga, Rune
    Olovsson, Ivar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Hydrogen Bond Studies. 24. The Crystal Structure of Hydrazinium Hydrogen Oxalate, N2H5HC2O41968In: Acta Chemica Scandinavica, ISSN 0904-213X, E-ISSN 1902-3103, Vol. 22, p. 88-96Article in journal (Refereed)
  • 9. Aili, Daniel
    et al.
    Enander, Karin
    Baltzer, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Liedberg, Bo
    Synthetic de novo designed polypeptides for control of nanoparticle assembly and biosensing2007In: Biochemical Society Transactions, ISSN 0300-5127, E-ISSN 1470-8752, Vol. 35, no 3, p. 532-534Article in journal (Refereed)
    Abstract [en]

    This contribution describes how de novo designed synthetic helix–loop–helix polypeptides are utilized tocontrol the assembly of gold nanoparticles and as scaffolds for biosensing. The synthetic polypeptides aredesigned to fold into a four-helix bundle upon dimerization. When immobilized on gold nanoparticles,dimerization and folding occur between peptides on neighbouring particles as an effect of particleaggregation and the folded polypeptides are rigid enough to keep the particles separated at a distancecorresponding to the size of the four-helix bundle. Moreover, peptide dimerization offers a convenientroute to assemble nanoparticles into hybrid multilayers on planar substrates. The drastic change in theresonance conditions of the localized nanoparticle surface plasmon upon particle aggregation is shown tobe useful for optical detection of biomolecular interactions.

  • 10.
    Alexander, James N.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Novel detection schemes and high resolution separations in microcolumn liquid separations1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Three micro detectors were developed and studied using micro-liquidchromatography (micro-LC). An evaporative light scattering detector (ELSD) nebulizer was developed for use with flow rates ranging from 0.5 to 10 µL/min. The parameters that affect analyte response were investigated and the most influential were capillary tip position and nebulization gas flow rate. One unique advantage of thismicro detector is that it can be operated at ambient conditions which allows for the analysis of semi-volatile compounds.

    A radio activity monitor (RAM) flow cell was developed for use at 3 µL/min and was designed for coupling to mass spectrometry (MS). The parameters that affect analyte response and band broadening were studied. Reducing the solid scintillant particle size to 9 µm and efficiently packing the solid cells allowed for direct coupling to MS without compromising the chromatographic separation.

    A nano-electrospray ionization (BSI) source for MS was developed and coupled to nano-LC and capillary electrophoresis (CE). This source incorporated a 50 µm i.d. stainless steel tip that was coupled to the separation capillary. At flow rates of 100 nL/min a stable electrospray was achieved.

    A multi-use separations system was developed for isocratic and gradient elution micro-LC, capillary electrochromatography (CEC), and pressure CEC (PEC). The details of the system and studies on peak area and retention time repeatability are reported. Comparisons are made between nano-LC and CEC. On average, column efficiency is 57% greater for CEC compared to nano-LC using the same nanocolumn.

  • 11.
    Alexander, JN
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Poli, JB
    Markides, KE
    Evaluation of automated isocratic and gradient nano-liquid chromatography and capillary electrochromatography1999In: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 71, no 13, p. 2398-2409Article in journal (Refereed)
    Abstract [en]

    An automated liquid nano-separation system has been developed for nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) using both isocratic and gradient elution, One fused-silica nanocolumn, typically 75 mu m i x 39 cm (25 cm ef

  • 12.
    Alfredsson, Maria
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Polar molecules in crystalline and surface environments: From first principles1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    With the knowledge of the composition and structure of a chemical system, be it a molecule, a two-dimensional surface or a three-dimensional crystal, it is now possible to predict the specific properties of the compound under consideration via computational studies. Molecular and periodic Hartree-Fock and DFT calculations have been used as a tool to study polar molecules and how their properties respond to the molecular environment in a crystal or on an ionic surface. The investigation covers a range of molecules (HF, HC1, HCN, H2O, OH-, OH., N2, CO and LiF) with different net charges, dipole moments and polarisibility, and a range of crystals and crystalline surfaces: hydrogen-bonded, ionic and ferroelectric.

    The step-wise build up of the molecular properties (geometries, energies, dipole moments, vibrational frequencies etc.) has been investigated. It was found that sorne molecular properties converge quickly towards the crystal value, others more slowly. Molecules adsorbed on a solid surface were studied as a function of adsorptionenergy, substrate and surface coverage. For the ionic surfaces studied here it was found that the properties of the chemi- and physisorbed molecules are as sensitive to the surface coverage as to the adsorption of the ad-molecule to the surface. The vibrational frequency shift of the ad-molecule has been given special attention.

    Finally the spontaneous polarisation in two ferroelectric crystals was calculated within the Berry-phase approach.

  • 13.
    Al-Maharik, N
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Engman, L
    Malmstrom, J
    Schiesser, CH
    Intramolecular homolytic substitution at selenium: Synthesis of novel selenium-containing vitamin E analogues2001In: JOURNAL OF ORGANIC CHEMISTRY, ISSN 0022-3263, Vol. 66, no 19, p. 6286-6290Article in journal (Refereed)
    Abstract [en]

    Treatment of 1-(benzylselenenyl)-5-butyl-5-nonanoI (10) with oxalyl chloride followed by the sodium salt of N-hydroxypyridine-2-thione afforded the corresponding pyridine-2-thione-N-oxycarbonyI (PTOC) oxalate ester which was not isolated but immediately h

  • 14.
    Almlöf, J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Kvick, Å.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Olovsson, Ivar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Hydrogen bond studies. XLVII. The crystal structure of the intermolecular complex 2-pyridone:6-chloro-2-hydroxypyridine1971In: Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, ISSN 0567-7408, Vol. 27, no 6, p. 1201-1208Article in journal (Refereed)
  • 15.
    Almlöf, J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Lundgren, J. O.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Olovsson, Ivar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Hydrogen bond studies. XLV. The crystal structure of HClO4.2.5H2O1971In: Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, ISSN 0567-7408, Vol. 27, no 5, p. 898-904Article in journal (Refereed)
  • 16. Alonso, D A
    et al.
    Bertilsson, S K
    Johnsson, S Y
    Nordin, S J M
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry, Organic Chemistry.
    Södergren, M J
    Andersson, Pher G
    New Expidient Route to Both Enantiomers of Nonproteinogenic Amino Acid Derivatives from the Unsaturated 2-Aza-bicyclo Moiety. D. A1999In: J. Org. Chem., Vol. 64, p. 2276-Article in journal (Refereed)
  • 17. Alonso, D A
    et al.
    Nordin, S J M
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry, Organic Chemistry.
    Andersson, Pher G
    Highly Diastereoselective Reaction of 2-Azanorbornyl Enolates with Electrophiles. D. A1999In: Org. Lett., Vol. 1, p. 1595-Article in journal (Refereed)
  • 18. Alonso, D A
    et al.
    Nordin, S J M
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry, Organic Chemistry.
    Roth, P
    Tarnai, T
    Thommen, M
    Pittelkow, U
    Andersson, Pher G
    2-Azanorbornyl alcohols: Very efficient Ligands for Ruthenium-Catalyzed Asymmetric Transfer Hydrogenation of Aromatic Ketones. D. A1999In: J. Org. Chem., Vol. 65, p. 3116-Article in journal (Refereed)
  • 19.
    Alonso, DA
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nordin, SJM
    Andersson, PG
    Highly diastereoselective reaction of 2-azanorbornyl enolates with electrophiles1999In: ORGANIC LETTERS, ISSN 1523-7060, Vol. 1, no 10, p. 1595-1597Article in journal (Refereed)
    Abstract [en]

    A highly diastereoselective reaction of 2-azanorbornyl enolates with electrophiles has been studied. Deprotonation of 4 with LDA at low temperature affords the corresponding exocyclic lithium enolate 5, which reacts with different electrophiles such as al

  • 20.
    Alonso, DA
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Nordin, SJM
    Roth, P
    Tarnai, T
    Andersson, PG
    Thommen, M
    Pittelkow, U
    2-azanorbornyl alcohols: Very efficient ligands for ruthenium-catalyzed asymmetric transfer hydrogenation of aromatic ketones2000In: JOURNAL OF ORGANIC CHEMISTRY, ISSN 0022-3263, Vol. 65, no 10, p. 3116-3122Article in journal (Refereed)
    Abstract [en]

    2-Azanorbornyl-derived amino alcohols were prepared and evaluated as ligands in the Ru(II)-catalyzed asymmetric transfer hydrogenation of aromatic ketones. To improve selectivity and rate, the structure of the ligand was optimized, Acetophenone was reduce

  • 21.
    Alonso, Diego A
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Brandt, P
    Nordin, Sofia J M
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Andersson, Pher G
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Organic Chemistry.
    Ru(arene)(amino alcohol)-Catalyzed Transfer Hydrogenation of Ketones: Mechanism and Origin of Enantioselectivity1999In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 121, no 41, p. 9580-9588Article in journal (Refereed)
    Abstract [en]

    The mechanism of the Ru(arene)(amino alcohol)-catalyzed transfer hydrogenation of ketones using isopropyl alcohol as the hydrogen source has been studied by means of hybrid density functional methods (B3PW91). Three mechanistic alternatives were evaluated, and it was shown that the reaction takes place via a six-membered transition state, where a metal-bound hydride and a proton of a coordinated amine are transferred simultaneously to the ketone. Further calculations provided a general rationale for the rate of the reaction by comparison of steric effects in the ground and transition states of the ruthenium hydride complex. It was found that the TS has a strong preference for planarity, and this in turn is dependent on the conformational behavior of the O,N-linkage of the amino alcohol ligand. Finally, a general model, rationalizing the enantioselectivity of the reaction, was developed. Experimental studies of both rate and enantioselectivity were used in order to support the computational results.

  • 22. Alonso, Diego
    et al.
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Deprotection of Sulfonyl Aziridines1998In: J. Org. Chem., no 63, p. 9455-9461Article in journal (Refereed)
  • 23. Alonso, Diego
    et al.
    Bertilsson, Sophie
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Johnsson, Sandra
    Nordin, Sofia
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Södergren, Mikael
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    New Expedient Route to Both Enantiomers of Nonproteinogenic a-Amino Acid Derivatives from the Unsaturated 2-Aza-Bicyclo Moiety1999In: J. Org. Chem., no 64, p. 2276-2280Article in journal (Refereed)
  • 24. Alonso, Diego
    et al.
    Brandt, Peter
    Nordin, Sofia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Andersson, Pher
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Ru(arene)(amino alcohol)-Catalyzed Transfer Hydrogenation of Ketones: Mechanism and Origin of Enantioselectivity1999In: J. Am. Chem. Soc., no 121, p. 9580-9588Article in journal (Refereed)
    Abstract
  • 25. Alonso, Diego
    et al.
    Guijarro, David
    Pinho, Pedro
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Temme, Oliver
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    (1S,3R,4R)-2-Azanorbornylmethanol, an Efficient Ligand for Ruthenium-Catalyzed Asymmetric Transfer Hydrogenation of Ketones1998In: J. Org. Chem., no 63, p. 2749-2751Article in journal (Refereed)
  • 26.
    Amirkhani, A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Heldin, E.
    Markides, K.E.
    Bergquist, J.
    Quantitation of tryptophan, kynurenine and kynurenic acid in human plasma by capillary liquid chromatography - electrospray ionization tandem mass spectrometry2002In: J. of Chromatography B, no 780, p. 381-387Article in journal (Refereed)
  • 27.
    Amirkhani, Ardeshir
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Development of Techniques and Methods for the Quantitative Analysis of Endogenous Substances by Microcolumn Liquid Chromatography Coupled to Mass Spectrometry2004Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Liquid chromatography-mass spectrometry (LC-MS) is a powerful technique for the analysis of endogenous compounds. The introduction of electrospray ionization (ESI) as an interface between LC and MS has contributed strongly to a trend towards miniaturization of LC, due to the possibility to perform ESI at low flow rates. In this thesis, several aspects regarding the design of miniaturized LC systems and electrospray emitters were investigated. In addition miniaturized LC-ESI-MS have been used for the qualitative and quantitative analysis of endogenous polar compounds, peptides and protein digests.

    The performance of miniaturized LC-MS was compared using different electrospray emitter configurations. The results indicated that the efficiency of the LC system is rather independent of the configuration of the emitter.

    The lifetime of gold-coated fused silica electrospray emitters based on vapor deposited adhesion layers of titanium were investigated. The long lifetime of the emitter facilitates the use in LC-MS experiments, exemplified LC-MS by analysis of neuropeptides.

    The ESI voltage is shown to interfere with liquid chromatographic separations performed in packed porous graphitic carbon capillary column. This interference is ascribed to the presence of an electric field over the conductive column in absence of a ground point between the column and the ESI emitter.

    The solid supported enhanced microdialysis for analysis of neuropeptides were compared with conventional microdialysis. The difference between the two methodologies were evaluated by LC-MS analysis of the microdialysates. The solid supported method gave in general higher relative recoveries.

    Finally, a method of standard addition was developed to determine total level of tryptophan and two of its metabolites in human plasma by capillary LC-ESI tandem mass spectrometry. The method was applied in a clinical study of multiple scleroses patients treated with cytokines (IFN Beta 1a, 1b). The results show that the intervention effects the tryptophan metabolism.

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  • 28.
    Amirkhani, Ardeshir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Heldin, Eva
    Markides, Karin E.
    Bergquist, Jonas
    Quantitation of tryptophan, kynurenine and kynurenic acid in human plasma by capillary liquid chromatography - electrospray2002In: Journal of Chromatography B, Vol. 780, no 2, p. 381-387Article in journal (Refereed)
  • 29.
    Amirkhani, Ardeshir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Rajda, Cecilia
    Arvidsson, Björn
    Bencsik, Krisztina
    Boda, Krisztina
    Seres, Erika
    Markides, Karin E.
    Vecsei, Laszlo
    Bergquist, Jonas
    Beta-interferon effects the tryptophan metabolism in the plasma of multiple sclerosis patientsManuscript (Other academic)
  • 30.
    Amirkhani, Ardeshir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Rajda, Cecilia
    Arvidsson, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Bencsik, Krisztina
    Boda, Krisztina
    Seres, Erika
    Markides, Karin E.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Vecsei, Laszlo
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Interferon-beta affects the tryptophan metabolism in multiple sclerosis patients2005In: European Journal of Neurology, ISSN 1351-5101, E-ISSN 1468-1331, Vol. 12, no 8, p. 625-631Article in journal (Refereed)
    Abstract [en]

    Tryptophan and its metabolites are of great interest in understanding the pathogenesis of multiple sclerosis (MS). The total levels of tryptophan and its metabolites, kynurenine and kynurenic acid were determined in plasma by capillary liquid chromatography electrospray ionisation tandem mass spectrometry. This is the first report of the plasma levels of these analytes in healthy controls and relapsing-remitting MS patients receiving long-term and acute interferon-beta (IFN-beta) treatment. Twenty-four hours post-administration increased kynurenine levels (first IFN MS versus healthy, P = 0.042) and kynurenine/tryptophan ratio (K/T; first IFN MS versus healthy, P =0.027; first IFN MS versus long-term IFN MS, P = 0.036) were found. The long-term IFN MS group had higher K/T ratios at 4 and 12 h post-administration (P = 0.015 and 0.009, respectively). The increase of K/T ratio in the first IFN MS group indicate an induction of the enzyme indolamine-2,3-dioxygenase (IDO), as reported earlier in experimental allergic encephalomyelitis. As IDO is participating in both inflammatory and neurodegenerative processes, further knowledge of its involvement in the pathogenesis of MS is of great importance.

  • 31.
    Amirkhani, Ardeshir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Wetterhall, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Nilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Danielsson, Rolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Comparison between different sheathless electrospray emitter configurations regarding the performance of nanoscale liquid chromatography time-of-flight mass spectrometry analysis2004In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1033, no 2, p. 257-266Article in journal (Refereed)
    Abstract [en]

    Four different sheathless electrospray ionization (ESI) configurations were investigated for a nano liquid chromatography (LC) system. The studied configurations were: a column with an integrated emitter, with the ESI potential applied before or after the column, and a column with separate emitter, with the ESI voltage applied at a union before the emitter or at the emitter tip. The results indicates that the efficiency of the LC system is rather independent of the configuration when using 95 μm i.d. columns, acetic mobile phase and standard peptides as a sample. Introduction of post column dead volume seems not to be a critical issue at least with flow rates down to 600 nl/min.

  • 32.
    Andersson, Anna S.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Lithium iron phosphates as cathode materials in lithium batteries2000Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Iron-based oxides are perhaps the only realistic cathode materials for electric and electric-hybrid vehicle applications. Two types of lithium iron phosphate, LiFePO4 andR-Li3Fe2(PO4)3, have been investigated for use within the lithium/lithium-ion polymer batteryconcept. The main techniques exploited have been: electrochemical cycling; X-ray andneutron diffraction - to study structural changes of the host material during lithiuminsertion/extraction; Mössbauer spectroscopy - to probe changes in the local structure of theFe atoms.

    Lithium extraction/insertion for LiFePO4, (olivine-type structure) has been followed by acombination of in situ X-ray diffraction and in situ Mössbauer spectroscopy. QuantitativeRietveld analysis of diffraction data has given good agreement with electrochemical andMössbauer spectroscopy data: ca. 20% of the LiFePO4 phase remains after charging. Possiblemechanisms to describe the capacity loss are proposed. High-temperature cycling (at 40oC and60oC) has shown the specific capacity to be markedly enhanced at higher temperatures.

    In situ Mössbauer spectroscopy has also been used to study the insertion of lithium into R-Li3Fe2(PO4)3. The two non-equivalent Fe3+ ions cannot be distinguished, whereas two typesof Fe2+ site appear on lithium insertion. Lithium appears to enter a site closer to one of theFe atoms. Elevated-temperature cycling shows the temperature dependence of R-Li3Fe2(PO4)3to be less marked than for the LiFePO4 system.

    The magnetic properties of R-Li3Fe2(PO4)3 have been investigated for the first time: a para- to antiferromagnetic transition is seen at 28 ~ K. Neutron powder diffraction shows that the Fe magnetic dipoles lie close to the ab-plane and are ferromagnetically aligned within an Fesheet perpendicular to the c-axis, but are antiferromagnetically coupled to adjacent sheets.

  • 33.
    Andersson, AS
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Kalska, B
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
    Jonsson, P
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science.
    Haggstrom, L
    Nordblad, P
    Tellgren, R
    Thomas, JO
    The magnetic structure and properties of rhombohedral Li3Fe2(PO4)(3)2000In: JOURNAL OF MATERIALS CHEMISTRY, ISSN 0959-9428, Vol. 10, no 11, p. 2542-2547Article in journal (Refereed)
    Abstract [en]

    Magnetic susceptibility measurements indicate that rhombohedral Li3Fe2(PO4)(3), obtained by ion exchange of monoclinic Na3Fe2(PO4)(3), exhibits a paramagnetic to antiferromagnetic transition at T-N approximate to 27 K. Curie-Weiss-like behaviour is observ

  • 34.
    Andersson, AS
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Thomas, JO
    Physics, Department of Physics.
    Kalska, B
    Haggstrom, L
    Thermal stability of LiFePO4-based cathodes2000In: ELECTROCHEMICAL AND SOLID STATE LETTERS, ISSN 1099-0062, Vol. 3, no 2, p. 66-68Article in journal (Refereed)
    Abstract [en]

    The capacity and cyclability of solid-state synthesized LiFePO4-based laminate cells of type <Li \ liq. el. \ LiFePO4> have been studied at 23, 40, and 60 degrees C. Larger capacities were obtained for cells cycled at the elevated temperatures. No evidenc

  • 35. Andersson, Lars I.
    et al.
    Hardenborg, Emilia
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Physical and Analytical Chemistry, Analytical Chemistry. Analytisk kemi.
    Sandberg-Ställ, Maria
    Möller, Kristina
    Henriksson, Johan
    Bramsby-Sjöström, Inger
    Olsson, Lars-Inge
    Abdel-Rehim, Mohamed
    Development of a molecularly imprinted polymer based solid-phase extraction of local anaesthetics from human plasma2004In: Analytica Chimica Acta, no 526, p. 147-154Article in journal (Refereed)
  • 36.
    Andersson, Marit
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Olin, Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    A modified standard addition method in X-ray fluorescence spectrometry1993In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 40, no 5, p. 669-674Article in journal (Refereed)
    Abstract [en]

    A modified standard addition method for single element determination by X-ray fluorescence spectrometry has been studied. The attenuation properties of the standard added samples are kept constant by adding decreasing amounts of an attenuation modifier along with increasing amounts of a standard. In this way the standard addition curve will be a straight line in cases where the ordinary standard addition curve is non-linear, and linear regression can be used to evaluate the concentration of the analyte. Standard additions of oxides of a number of elements, with and without modifier, have been made to cellulose powder or a mixture of aluminium oxide and polyethylene as matrices in order to test the method. The method has been applied to the determination of zinc in fly-ash from a steel work and of iron in cement. The fly-ash contained about 5% of zinc and the cement samples between 2 and 5% of Fe(2)O(3). The results were compared with those obtained by ICP-AES after decomposition of samples in lithium tetraborate or lithium metaborate and dissolution of the melt in 10%(v/v) nitric acid. The results agreed within 2%, relative, for fly-ash and within 3-6%, relative, for cement samples.

  • 37.
    Andersson, Marit
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Olin, Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Determination of lead in household refuse fly-ash by X-ray fluorescence spectrometry and a modified standard-addition technique1991In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 38, no 4, p. 385-390Article in journal (Refereed)
    Abstract [en]

    Lead in fly-ash from a garbage incinerator has been determined by X-ray fluorescence spectrometry (XRFS) and a modified standard-addition method. To keep the attenuation properties of the spiked samples constant, decreasing amounts of an attenuation modifier [mercury (II) acetate] were added together with increasing amounts of the standard (lead nitrate). Linearity between fluorescence intensity and amount of lead was thus obtained, so the amount of lead in the sample could be evaluated by linear regression. The amount of modifier needed could be calculated from a simple expression. The method was validated by comparison with the results obtained by applying atomic-absorption spectrometry (AAS) to solutions made by leaching the fly-ash with strong acid. For 8 fly-ash samples, containing between 0.8 and 1.35% lead, the largest absolute difference between the two sets of results was 0.03%. Theoretical calculations based on a simplified version of the Sherman equation were performed to confirm the linearity of the modified standard-addition curves.

  • 38.
    Andersson, Mikael
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Analytisk kemi.
    Characterisation of the chemical and functional stability of chromatography media2000Licentiate thesis, monograph (Other scientific)
  • 39.
    Andersson, P.G.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry.
    Development of New Methodology for th Preparation of Optically Active Alcohols2004In: Pure Appl. Chem., no 76, p. 547-Article in journal (Refereed)
  • 40.
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    On the Stereochemical Outcome of the McMurry Coupling of Acetophenone. A Reinvestigation1994In: Tetrahedron Letters, Vol. 35, no 16, p. 2609-2610Article in journal (Refereed)
  • 41.
    Andersson, Pher
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Regio- and Stereoselective Deuteration of Allylic Chlorides Controlled by Neighboring Alcohol or Ether Groups1996In: J. Org. Chem., no 61, p. 4154-4156Article in journal (Refereed)
  • 42.
    Andersson, Pher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Aranyos, Attila
    Palladium-Mediated Stereo- and Regioselective Tandem-Cyclization-Carbonylations of 1,3-dienes1994In: Tetrahedron Letters, Vol. 35, no 25, p. 4441-4444Article in journal (Refereed)
  • 43.
    Andersson, Pher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Bäckvall, Jan-E.
    Palladium-Catalyzed Tandem Cyclization of 4,6- and 5,7-Diene Amides. A New Route towards the Pyrrolizidine and Indolizidine Alkaloids1992In: J. Am. Chem. Soc., Vol. 114, no 22, p. 8696-8698Article in journal (Refereed)
  • 44.
    Andersson, Pher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Bäckvall, Jan-E.
    Synthesis of Furanoid Terpenes via an Efficient Palladium-Catalyzed Cyclization of 4,6-Dienols1991In: J. Org. Chem., Vol. 56, no 18, p. 5349-5353Article in journal (Refereed)
  • 45.
    Andersson, Pher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Bäckvall, Jan-E.
    Synthesis of Heterocyclic Natural Products via Regio- and Stereocontrolled Palladium-Catalyzed Reactions1996In: Advances in Heterocyclic Natural Product Synthesis, JAI Press Inc, Greenwich , 1996, p. 179-215Chapter in book (Refereed)
  • 46.
    Andersson, Pher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Guijarro, David
    Tanner, David
    Preparation and Use of Aziridino Alcohols as Promoters for the Enantioselective Addition of Dialkylzinc Reagents to N-(Diphenylphosphinoyl) Imines1997In: J. Org. Chem., no 62, p. 7364-7375Article in journal (Refereed)
  • 47.
    Andersson, Pher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Guijarro, David
    Tanner, David
    Simple Aziridino Alcohols as Chiral Ligands. Enantioselective Additions of Diethylzinc to N-Diphenylphosphinoylimines1996In: Synlett, no 8, p. 727-728Article in journal (Refereed)
  • 48.
    Andersson, Pher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Harden, Adrian
    Tanner, David
    Norrby, Per-Ola
    Studies of Allylic Substitution Catalysed by a Palladium Complex of a C2-Symmetric Bis(aziridine): Preparation and NMR Spectroscopic Investigation of a Chiral n-Allyl Species1995In: Chem. Eur. J., no 1, p. 12-16Article in journal (Refereed)
  • 49.
    Andersson, Pher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Johansson, Fredrik
    Tanner, David
    Enantioselective Addition of Organolithium Reagents to Imines Mediated by C2-Symmetric Bis(aziridine) Ligands1998In: Tetrahedron, no 54, p. 11549-11566Article in journal (Refereed)
  • 50.
    Andersson, Pher
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Chemistry. Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Nilsson, Ylva
    Bäckvall, Jan-E.
    Palladium-Catalyzed Oxaspirocyclizations1994In: Tetrahedron, Vol. 50, no 2, p. 559-572Article in journal (Refereed)
1234567 1 - 50 of 1140
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